研究者総覧

永井 良三 (ナガイ リョウゾウ)

  • 学長 学長
Last Updated :2021/11/23

研究者情報

学位

  • 博士(医学)

ホームページURL

J-Global ID

研究キーワード

  • 心血管病学   molecular biology   KLF5   transcription factor   

研究分野

  • ライフサイエンス / 循環器内科学

所属学協会

  • 日本動脈硬化学会   日本心臓病学会   日本高血圧学会   日本循環器学会   日本内科学会   

研究活動情報

論文

  • Mitsuru Abe, Yukio Ozaki, Hiroshi Takahashi, Mitsuru Ishii, Nobutoyo Masunaga, Tevfik F Ismail, Satoshi Iimuro, Retsu Fujita, Hiroshi Iwata, Ichiro Sakuma, Yoshihisa Nakagawa, Kiyoshi Hibi, Takafumi Hiro, Yoshihiro Fukumoto, Seiji Hokimoto, Katsumi Miyauchi, Hisao Ogawa, Hiroyuki Daida, Hiroaki Shimokawa, Yasushi Saito, Masunori Matsuzaki, Masaharu Akao, Takeshi Kimura, Ryozo Nagai
    American heart journal 240 89 - 100 2021年06月 
    BACKGROUND: It has not yet been established whether higher-dose statins have beneficial effects on cardiovascular events in patients with stable coronary artery disease (CAD) and renal dysfunction. METHODS: The REAL-CAD study is a prospective, multicenter, open-label trial. As a substudy, we categorized patients by an estimated glomerular filtration rate (eGFR) as follows: eGFR ≥60 (n = 7,768); eGFR ≥45 and <60 (n = 3,176); and eGFR <45 mL/Min/1.73 m2 (n = 1,164), who were randomized to pitavastatin 4mg or 1mg therapy. The primary endpoint was a composite of cardiovascular death, non-fatal myocardial infarction, non-fatal ischemic stroke, or unstable angina, and was assessed by the log-rank test and Cox proportional hazards model. RESULTS: The baseline characteristics and medications were largely well-balanced between two groups. The magnitude of low-density lipoprotein cholesterol (LDL-C) reduction at 6 months in high- and low-dose pitavastatin groups was comparable among all eGFR categories. During a median follow-up of 3.9 years, high- compared with low-dose pitavastatin significantly reduced cardiovascular events in patients with eGFR ≥60 (hazard ratio (HR) 0.73; 95% confidence interval (CI) 0.58-0.91; P = .006), and reduced but not significant for patients with eGFR ≥45 and <60 (HR 0.85; 95% CI, 0.63-1.14; P = .27) or eGFR <45 mL/Min/1.73 m2 (HR 0.90; 95% CI 0.62-1.33; P = .61). An interaction test of treatment by eGFR category was not significant (P value for interaction = .30). CONCLUSION: Higher-dose pitavastatin therapy reduced LDL levels and cardiovascular events in stable CAD patients irrespective of eGFR level, although the effect on events appeared to be numerically lower in patients with lower eGFR.
  • Junichi Sugita, Katsuhito Fujiu, Yukiteru Nakayama, Takumi Matsubara, Jun Matsuda, Tsukasa Oshima, Yuxiang Liu, Yujin Maru, Eriko Hasumi, Toshiya Kojima, Hiroshi Seno, Keisuke Asano, Ayumu Ishijima, Naoki Tomii, Masatoshi Yamazaki, Fujimi Kudo, Ichiro Sakuma, Ryozo Nagai, Ichiro Manabe, Issei Komuro
    Nature communications 12 1 1910 - 1910 2021年03月 
    Cardiac arrhythmias are a primary contributor to sudden cardiac death, a major unmet medical need. Because right ventricular (RV) dysfunction increases the risk for sudden cardiac death, we examined responses to RV stress in mice. Among immune cells accumulated in the RV after pressure overload-induced by pulmonary artery banding, interfering with macrophages caused sudden death from severe arrhythmias. We show that cardiac macrophages crucially maintain cardiac impulse conduction by facilitating myocardial intercellular communication through gap junctions. Amphiregulin (AREG) produced by cardiac macrophages is a key mediator that controls connexin 43 phosphorylation and translocation in cardiomyocytes. Deletion of Areg from macrophages led to disorganization of gap junctions and, in turn, lethal arrhythmias during acute stresses, including RV pressure overload and β-adrenergic receptor stimulation. These results suggest that AREG from cardiac resident macrophages is a critical regulator of cardiac impulse conduction and may be a useful therapeutic target for the prevention of sudden death.
  • Kazunori Omote, Isao Yokota, Toshiyuki Nagai, Ichiro Sakuma, Yoshihisa Nakagawa, Kiwamu Kamiya, Hiroshi Iwata, Katsumi Miyauchi, Yukio Ozaki, Kiyoshi Hibi, Takafumi Hiro, Yoshihiro Fukumoto, Hiroyoshi Mori, Seiji Hokimoto, Yasuo Ohashi, Hiroshi Ohtsu, Hisao Ogawa, Hiroyuki Daida, Satoshi Iimuro, Hiroaki Shimokawa, Yasushi Saito, Takeshi Kimura, Masunori Matsuzaki, Ryozo Nagai, Toshihisa Anzai
    Journal of atherosclerosis and thrombosis 2021年01月 
    AIM: The association between high-density lipoprotein cholesterol (HDL-C) level after statin therapy and cardiovascular events in patients with stable coronary artery disease (CAD) remains unclear. Thus, in this study, we sought to determine how HDL-C level after statin therapy is associated with cardiovascular events in stable CAD patients. METHODS: From the REAL-CAD study which had shown the favorable prognostic effect of high-dose pitavastatin in stable CAD patients with low-density lipoprotein cholesterol (LDL-C) <120 mg/dL, 9,221 patients with HDL-C data at baseline and 6 months, no occurrence of primary outcome at 6 months, and reported non-adherence for pitavastatin, were examined. The primary outcome was a composite of cardiovascular death, non-fatal myocardial infarction, non-fatal ischemic stroke, or unstable angina requiring emergent admission after 6 months of randomization. Absolute difference and ratio of HDL-C levels were defined as (those at 6 months-at baseline) and (absolute difference/baseline)×100, respectively. RESULTS: During a median follow-up period of 4.0 (IQR 3.2-4.7) years, the primary outcome occurred in 417 (4.5%) patients. The adjusted risk of all HDL-C-related variables (baseline value, 6-month value, absolute, and relative changes) for the primary outcome was not significant (hazard ratio [HR] 0.99, 95% confidence interval [CI] 0.91-1.08, HR 1.03, 95% CI 0.94-1.12, HR 1.05, 95% CI 0.98-1.12, and HR 1.08, 95% CI 0.94-1.24, respectively). Furthermore, adjusted HRs of all HDL-C-related variables remained non-significant for the primary outcome regardless of on-treatment LDL-C level at 6 months. CONCLUSIONS: After statin therapy with modestly controlled LDL-C, HDL-C level has little prognostic value in patients with stable CAD.
  • Masaharu Nakayama, Kazuya Takehana, Takahide Kohro, Tetsuya Matoba, Hiroyuki Tsutsui, Ryozo Nagai
    Circulation Reports 2 10 587 - 616 2020年10月
  • Kouki Nakamura, Takashi Taniguchi, Megumi Hirabayashi, Takashi Yamashita, Ryosuke Saigusa, Shunsuke Miura, Takehiro Takahashi, Tetsuo Toyama, Yohei Ichimura, Ayumi Yoshizaki, Maria Trojanowska, Katsuhito Fujiu, Ryozo Nagai, Shinichi Sato, Yoshihide Asano
    Arthritis & rheumatology (Hoboken, N.J.) 2020年07月 [査読有り][通常論文]
     
    OBJECTIVE: We previously established a new animal model (Klf5+/- ;Fli1+/- mice) broadly recapitulating fundamental pathologic features of systemic sclerosis (SSc). SSc vasculopathy is believed to occur as a result of impaired vascular remodeling, but its detailed mechanism has remained unknown. To address this issue, we investigated the properties of dermal microvascular endothelial cells (DMECs), bone marrow-derived endothelial progenitor cells (BM-EPCs) and bone marrow-derived mesenchymal stem cells (BM-MSCs), a precursor of pericytes, in Klf5+/- ;Fli1+/- mice. METHODS: Neovascularization and angiogenesis were assessed by in vivo Matrigel plug assay and in vitro tube formation assay, respectively. The properties of BM-EPCs and BM-MSCs were assessed in in vitro studies. Dermal vasculature was visualized in vivo by FITC-dextran injection. RESULTS: Neovascularization was diminished in skin-embedded Matrigel plug in Klf5+/- ;Fli1+/- mice. Klf5+/- ;Fli1+/- DMECs showed defective tubulogenic activity, decreased expression of VE-cadherin and CD31, and imbalance of Notch1/delta-like ligand 4, suggesting that angiogenesis and anastomosis are disturbed. Klf5+/- ;Fli1+/- BM-MSCs exhibited enhanced proliferation, migration and collagen production by transforming growth factor-β1, indicating the preferential differentiation into myofibroblasts rather than pericytes. Klf5+/- ;Fli1+/- BM-EPCs displayed the transition toward mesenchymal cells, suggesting that vasculogenesis is impaired. Wound healing was delayed in Klf5+/- ;Fli1+/- mice (15.67 ± 0.82 days versus 13.50 ± 0.84 days; P = 0.0017), and vascular network was poorly developed in wound scar tissue. CONCLUSION: Klf5+/- ;Fli1+/- mice represent impaired neovascularization and vascular maturation similar to those of SSc at least partially due to the induction of SSc-like properties in DMECs, BM-EPCs and BM-MSCs, indicating the critical contribution of KLF5 and Fli1 deficiency in vascular cells and related precursors to SSc vasculopathy.
  • 電子カルテから多モダリティ循環器診療情報を収集するCLIDASデータベースシステム
    的場 哲哉, 興梠 貴英, 藤田 英雄, 苅尾 七臣, 中山 雅晴, 清末 有宏, 宮本 恵宏, 辻田 賢一, 中島 直樹, 筒井 裕之, 永井 良三
    日本動脈硬化学会総会プログラム・抄録集 52回 257 - 257 (一社)日本動脈硬化学会 2020年07月
  • Yoshiyuki Yazaki, Kenichi Aizawa, Muhammad Zubair Israr, Keita Negishi, Andrea Salzano, Yuka Saitoh, Natsuka Kimura, Ken Kono, Liam Heaney, Shabana Cassambai, Dennis Bernieh, Florence Lai, Yasushi Imai, Kazuomi Kario, Ryozo Nagai, Leong L Ng, Toru Suzuki
    ESC heart failure 2020年06月 [査読有り][通常論文]
     
    AIMS: The aim of this study was to investigate whether ethnicity influences the associations between trimethylamine N-oxide (TMAO) levels and heart failure (HF) outcomes. METHODS AND RESULTS: Trimethylamine N-oxide levels were measured in two cohorts with acute HF at two sites. The UK Leicester cohort consisted mainly of Caucasian (n = 842, 77%) and South Asian (n = 129, 12%) patients, whereas patients in the Japanese cohort (n = 116, 11%) were all Japanese. The primary endpoint was the measurement of all-cause mortality and/or HF rehospitalization within 1 year post-admission. Association of TMAO levels with outcome was compared in the entire population and between ethnic groups after adjustment for clinical parameters. TMAO levels were significantly higher in Japanese patients [median (interquartile range): 9.9 μM (5.2-22.8)] than in Caucasian [5.9 μM (3.6-10.8)] and South Asian [4.5 μM (3.1-8.4)] (P < 0.001) patients. There were no differences in the rate of mortality and/or HF rehospitalization between the ethnic groups (P = 0.096). Overall, higher TMAO levels showed associations with mortality and/or rehospitalization after adjustment for confounders ( P = 0.002). Despite no differences between ethnicity and association with mortality/HF after adjustment (P = 0.311), only in Caucasian patients were TMAO levels able to stratify for a mortality/HF event (P < 0.001). CONCLUSIONS: Differences were observed in the association of mortality and/or rehospitalization based on circulating TMAO levels. Elevated TMAO levels in Caucasian patients showed increased association with adverse outcomes, but not in non-Caucasian patients.
  • Yukiteru Nakayama, Katsuhito Fujiu, Ryuzaburo Yuki, Yumiko Oishi, Masaki Suimye Morioka, Takayuki Isagawa, Jun Matsuda, Tsukasa Oshima, Takumi Matsubara, Junichi Sugita, Fujimi Kudo, Atsushi Kaneda, Yusuke Endo, Toshinori Nakayama, Ryozo Nagai, Issei Komuro, Ichiro Manabe
    Proceedings of the National Academy of Sciences of the United States of America 117 25 14365 - 14375 2020年06月 [査読有り][通常論文]
     
    Proper resolution of inflammation is vital for repair and restoration of homeostasis after tissue damage, and its dysregulation underlies various noncommunicable diseases, such as cardiovascular and metabolic diseases. Macrophages play diverse roles throughout initial inflammation, its resolution, and tissue repair. Differential metabolic reprogramming is reportedly required for induction and support of the various macrophage activation states. Here we show that a long noncoding RNA (lncRNA), lncFAO, contributes to inflammation resolution and tissue repair in mice by promoting fatty acid oxidation (FAO) in macrophages. lncFAO is induced late after lipopolysaccharide (LPS) stimulation of cultured macrophages and in Ly6Chi monocyte-derived macrophages in damaged tissue during the resolution and reparative phases. We found that lncFAO directly interacts with the HADHB subunit of mitochondrial trifunctional protein and activates FAO. lncFAO deletion impairs resolution of inflammation related to endotoxic shock and delays resolution of inflammation and tissue repair in a skin wound. These results demonstrate that by tuning mitochondrial metabolism, lncFAO acts as a node of immunometabolic control in macrophages during the resolution and repair phases of inflammation.
  • Tsuyoshi Shiga, Takanori Ikeda, Wataru Shimizu, Koichiro Kinugawa, Atsuhiro Sakamoto, Ryozo Nagai, Takashi Daimon, Kaori Oki, Haruka Okamoto, Takeshi Yamashita
    Circulation reports 2 8 440 - 445 2020年06月 
    Background: Post hoc analysis was used to investigate the effects of renal function on the efficacy and safety of landiolol using data from the J-Land II study, which evaluated landiolol in patients with hemodynamically unstable ventricular tachycardia (VT) or ventricular fibrillation (VF) who were refractory to Class III antiarrhythmic drugs. Methods and Results: Patient data from the J-Land II study (n=29) were stratified by renal function (estimated glomerular filtration rate [eGFR] <45 and ≥45 mL/min/1.73 m2) and analyzed. Continuous landiolol infusion (1 μg/kg/min, i.v.) was initiated after VT/VF was suppressed with electrical defibrillation; subsequent dose adjustments were made (1-40 μg/kg/min). The primary efficacy endpoint was the proportion of patients free from recurrent VT/VF during the assessment period. Safety endpoints were also assessed. In the eGFR <45 and ≥45 mL/min/1.73 m2 groups, the median doses of landiolol during the assessment period were 9.44 and 8.97 μg/kg/min, the proportions of patients free from recurrent VT/VF were 69.2% and 81.8%, and adverse events occurred in 9 and 10 of 13 patients in each group, respectively. There were no apparent differences in the efficacy or safety of landiolol between the 2 groups. Conclusions: The data suggest that renal function may not affect the efficacy and safety of landiolol for hemodynamically unstable VT or VF.
  • Taro Kariya, Takumi Washio, Jun-Ichi Okada, Machiko Nakagawa, Masahiro Watanabe, Yoshimasa Kadooka, Shunji Sano, Ryozo Nagai, Seiryo Sugiura, Toshiaki Hisada
    Annals of biomedical engineering 48 6 1740 - 1750 2020年06月 [査読有り][通常論文]
     
    For treatment of complex congenital heart disease, computer simulation using a three-dimensional heart model may help to improve outcomes by enabling detailed preoperative evaluations. However, no highly integrated model that accurately reproduces a patient's pathophysiology, which is required for this simulation has been reported. We modelled a case of complex congenital heart disease, double outlet right ventricle with ventricular septal defect and atrial septal defect. From preoperative computed tomography images, finite element meshes of the heart and torso were created, and cell model of cardiac electrophysiology and sarcomere dynamics was implemented. The parameter values of the heart model were adjusted to reproduce the patient's electrocardiogram and haemodynamics recorded preoperatively. Two options of in silico surgery were performed using this heart model, and the resulting changes in performance were examined. Preoperative and postoperative simulations showed good agreement with clinical records including haemodynamics and measured oxyhaemoglobin saturations. The use of a detailed sarcomere model also enabled comparison of energetic efficiency between the two surgical options. A novel in silico model of congenital heart disease that integrates molecular models of cardiac function successfully reproduces the observed pathophysiology. The simulation of postoperative state by in silico surgeries can help guide clinical decision-making.
  • Yuji Nishizaki, Kazunori Shimada, Shigemasa Tani, Takayuki Ogawa, Jiro Ando, Masao Takahashi, Masato Yamamoto, Tomohiro Shinozaki, Tetsuro Miyazaki, Katsumi Miyauchi, Ken Nagao, Atsushi Hirayama, Michihiro Yoshimura, Issei Komuro, Ryozo Nagai, Hiroyuki Daida
    BMC cardiovascular disorders 20 1 160 - 160 2020年04月 [査読有り][通常論文]
     
    BACKGROUND: Previous studies have reported that being overweight, obese, or underweight is a risk factor for ischemic cardiovascular disease (CVD); however, CVD also occurs in subjects with ideal body mass index (BMI). Recently, the balance of n-3/n-6 polyunsaturated fatty acids (PUFAs) has received attention as a risk marker for CVD but, so far, no study has been conducted that investigates the association between BMI and the balance of n-3/n-6 PUFAs for CVD risk. METHODS: We evaluated the association between n-3/n-6 PUFA ratio and acute coronary syndrome (ACS) in three BMI-based groups (< 25: low BMI, 25-27.5: moderate BMI, and ≥ 27.5: high BMI) that included 1666 patients who visited the cardiovascular medicine departments of five hospitals located in urban areas in Japan. RESULTS: The prevalence of ACS events was 9.2, 7.3, and 10.3% in the low, moderate, and high BMI groups, respectively. We analyzed the relationship between ACS events and several factors, including docosahexaenoic acid/arachidonic acid (DHA/AA) ratio by multivariate logistic analyses. In the low BMI group, a history of smoking (odds ratio [OR]: 2.47, 95% confidence interval [CI]: 1.40-4.35) and low DHA/AA ratio (OR: 0.30, 95% CI: 0.12-0.74) strongly predicted ACS. These associations were also present in the moderate BMI group but the magnitude of the association was much weaker (ORs are 1.47 [95% CI: 0.54-4.01] for smoking and 0.63 [95% CI: 0.13-3.10] for DHA/AA). In the high BMI group, the association of DHA/AA (OR: 1.98, 95% CI: 0.48-8.24) was reversed and only high HbA1c (OR: 1.46, 95% CI: 1.03-2.08) strongly predicted ACS. The interaction test for OR estimates (two degrees of freedom) showed moderate evidence for reverse DHA/AA ratio-ACS associations among the BMI groups (P = 0.091). CONCLUSIONS: DHA/AA ratio may be a useful marker for risk stratification of ACS, especially in non-obese patients.
  • Hideki Hashimoto, Makoto Saito, Jumpei Sato, Kazuo Goda, Naohiro Mitsutake, Masaru Kitsuregawa, Ryozo Nagai, Shuji Hatakeyama
    International journal of infectious diseases : IJID : official publication of the International Society for Infectious Diseases 91 1 - 8 2020年02月 [査読有り][通常論文]
     
    OBJECTIVES: To evaluate condition-specific antibiotic prescription rates and the appropriateness of antibiotic use in outpatient settings in Japan. METHODS: Using Japan's national administrative claims database, all outpatient visits with infectious disease diagnoses were linked to reimbursed oral antibiotic prescriptions. Prescription rates stratified by age, sex, prefecture, and antibiotic category were determined for each infectious disease diagnosis. The proportions of any antibiotic prescription to all infectious disease visits and the proportions of first-line antibiotic prescriptions to all antibiotic prescriptions were calculated for each infectious disease diagnosis. RESULTS: Of the 659 million infectious disease visits between April 2012 and March 2015, antibiotics were prescribed in 266 million visits (704 prescriptions per 1000 population per year). Third-generation cephalosporins, macrolides, and quinolones accounted for 85.9% of all antibiotic prescriptions. Fifty-six percent of antibiotic prescriptions were directed toward infections for which antibiotics are generally not indicated. The diagnoses with frequent antibiotic prescription were bronchitis (184 prescriptions per 1000 population per year), viral upper respiratory infections (166), pharyngitis (104), sinusitis (52), and gastrointestinal infection (41), for which 58.3%, 40.6%, 58.9%, 53.9%, and 26.1% of visits antibiotics were prescribed, respectively. First-line antibiotics were rarely prescribed for pharyngitis (8.8%) and sinusitis (9.8%). More antibiotics were prescribed for children aged 0-9 years, adult women, and patients living in western Japan. CONCLUSIONS: Antibiotic prescription rates are high in Japan. Acute respiratory or gastrointestinal infections, which received the majority of the antibiotics generally not indicated, should be the main targets of antimicrobial stewardship intervention.
  • Michiru Kakinuma, Hiroo Ide, Kyoko Nakao, Daisuke Ichikawa, Ryozo Nagai, Yuji Furui
    Archives of environmental & occupational health 75 4 226 - 234 2020年 [査読有り][通常論文]
     
    This study, conducted at major Japanese companies, aimed to determine if asymptomatic workers in workplaces with a high prevalence of metabolic syndrome have a greater risk of developing metabolic syndrome. Data were obtained from the health records of 298,145 people, from 2011 to 2015. We collected data on the participants' age, sex, physical examinations, laboratory tests, and lifestyle behaviors. To test whether the risk of metabolic syndrome in asymptomatic workers differed between groups with a higher and lower prevalence in 2011, Cox proportional hazards regression model was performed, with the covariates being controlled for. The analysis showed that the risk of metabolic syndrome among asymptomatic workers in the high-prevalence group was about 1.1-fold elevated compared to those within the low-prevalence group. As a follow-up to these results, interventions aimed at asymptomatic workers should be provided in workplaces with a high prevalence of metabolic syndrome.
  • 多モダリティ循環器診療情報を収集するCLIDASデータベース
    的場 哲哉, 興梠 貴英, 藤田 英雄, 苅尾 七臣, 中山 雅晴, 清末 有宏, 辻田 賢一, 宮本 恵宏, 中島 直樹, 筒井 裕之, 永井 良三
    医療情報学連合大会論文集 39回 155 - 155 (一社)日本医療情報学会 2019年11月
  • Tomoyuki Kabutoya, Hisahiko Sato, Eiji Aramaki, Kazuomi Kario, Ryozo Nagai
    Internal medicine (Tokyo, Japan) 58 15 2145 - 2150 2019年08月 [査読有り][通常論文]
     
    Objective To examine case reports presented at the Regional Meeting of the Japanese Society of Internal Medicine in order to clarify the underlying disease and prognosis of heart failure, which is often caused by non-cardiovascular diseases. Methods We examined 49,693 case reports from the Japanese Society of Internal Medicine database. A total of 2,893 reports were included after excluding 46,022 reports that did not include the term "heart failure" and 778 reports with no indications of symptoms of heart failure. We assessed each patient's basal disease, and according to the abstracts, we reported their prognosis as dead or alive. Results Of the 2,893 reports included, 1,952 (67.5%) and 941 (32.5%) had cardiovascular and non-cardiovascular diseases as the causes, respectively; these cases were attributed to 725 different diseases, 196 (27.0%) and 529 (73.0%) of which were cardiovascular and non-cardiovascular diseases, respectively. In addition, 91 different side effects were identified. The percentage of cases of heart failure-related mortality was significantly higher among the patients with non-cardiovascular diseases than in those with cardiovascular diseases (17.8% vs. 10.8%; p <0.001). Of the diseases reported as causes of heart failure in more than 10 reports, pulmonary tumor thrombotic microangiopathy (87%), multiple myeloma (50%), and amyloidosis (47%) accounted for the highest percentages of heart failure-related mortality. Conclusion Because heart failure is often caused by non-cardiovascular diseases, a broad study of case reports on internal medicine is important for cardiologists.
  • Shota Tomida, Kenichi Aizawa, Norifumi Nishida, Hiroki Aoki, Yasushi Imai, Ryozo Nagai, Toru Suzuki
    Scientific reports 9 1 10751 - 10751 2019年07月 [査読有り][通常論文]
     
    Aortic dissection is a life-threatening condition, which is characterised by separation of the constituent layers of the aortic wall. We have recently shown that monocyte/macrophage infiltration into the aortic wall is a pathogenic mechanism of the condition. In the present study, we investigated whether the anti-inflammatory agent, indomethacin, could inhibit monocyte/macrophage accumulation in the aortic wall and ensuing dissection. Indomethacin was administered (from 3 days prior with daily oral administration) to mice in which aortic dissection was induced using beta-aminopropionitrile (BAPN) and angiotensin II (Ang II) infusion (2 weeks). Indomethacin prevented death from abdominal aortic dissection and decreased incidence of aortic dissection by as high as 40%. Histological and flow cytometry analyses showed that indomethacin administration resulted in inhibition of monocyte transendothelial migration and monocyte/macrophage accumulation in the aortic wall. These results indicate that indomethacin administration reduces rate of onset of aortic dissection in a murine model of the condition.
  • Hajime Abe, Norihiko Takeda, Takayuki Isagawa, Hiroaki Semba, Satoshi Nishimura, Masaki Suimye Morioka, Yu Nakagama, Tatsuyuki Sato, Katsura Soma, Katsuhiro Koyama, Masaki Wake, Manami Katoh, Masataka Asagiri, Michael L Neugent, Jung-Whan Kim, Christian Stockmann, Tomo Yonezawa, Ryo Inuzuka, Yasushi Hirota, Koji Maemura, Takeshi Yamashita, Kinya Otsu, Ichiro Manabe, Ryozo Nagai, Issei Komuro
    Nature communications 10 1 2824 - 2824 2019年06月 [査読有り][通常論文]
     
    The fibrogenic response in tissue-resident fibroblasts is determined by the balance between activation and repression signals from the tissue microenvironment. While the molecular pathways by which transforming growth factor-1 (TGF-β1) activates pro-fibrogenic mechanisms have been extensively studied and are recognized critical during fibrosis development, the factors regulating TGF-β1 signaling are poorly understood. Here we show that macrophage hypoxia signaling suppresses excessive fibrosis in a heart via oncostatin-m (OSM) secretion. During cardiac remodeling, Ly6Chi monocytes/macrophages accumulate in hypoxic areas through a hypoxia-inducible factor (HIF)-1α dependent manner and suppresses cardiac fibroblast activation. As an underlying molecular mechanism, we identify OSM, part of the interleukin 6 cytokine family, as a HIF-1α target gene, which directly inhibits the TGF-β1 mediated activation of cardiac fibroblasts through extracellular signal-regulated kinase 1/2-dependent phosphorylation of the SMAD linker region. These results demonstrate that macrophage hypoxia signaling regulates fibroblast activation through OSM secretion in vivo.
  • Takanori Ikeda, Tsuyoshi Shiga, Wataru Shimizu, Koichiro Kinugawa, Atsuhiro Sakamoto, Ryozo Nagai, Takashi Daimon, Kaori Oki, Haruka Okamoto, Takeshi Yamashita
    Circulation journal : official journal of the Japanese Circulation Society 83 7 1456 - 1462 2019年06月 [査読有り][通常論文]
     
    BACKGROUND: We aimed to investigate the efficacy and safety of landiolol in Japanese patients with recurrent hemodynamically unstable ventricular tachycardia or recurrent ventricular fibrillation (recurrent VT/VF).Methods and Results:This was an open-label, uncontrolled, multicenter study. Patients with hemodynamically unstable VT or VF 24 h prior to providing informed consent, and who were refractory to class III antiarrhythmic drugs, were enrolled. Landiolol was started at a dose of 1 μg/kg/min, after VT/VF was suppressed with electrical defibrillation. Landiolol was titrated up to 10 μg/kg/min in 1 h and adjusted between 1 and 40 μg/kg/min for the efficacy assessment (1-49 h). The primary efficacy endpoint was the proportion of patients free from recurrent VT/VF. Secondary efficacy endpoints included the number of recurrent VT/VF events and the survival rate 30 days after the start of landiolol treatment. Adverse events (AEs) were assessed for safety; 27 and 29 patients were analyzed for efficacy and safety, respectively. The proportion of patients free from recurrent VT/VF was 77.8% (95% CI 57.1-89.3). The mean (±standard deviation) number of recurrent VT/VF events was 9.3±7.9. The survival rate was 96.3%. The overall incidence of AEs and of serious AEs was 72.4% and 6.9%, respectively. CONCLUSIONS: Landiolol may be useful for Japanese patients with recurrent VT/VF who do not respond to class III antiarrhythmic drugs.
  • Hideki Hashimoto, Hiroki Matsui, Yusuke Sasabuchi, Hideo Yasunaga, Kazuhiko Kotani, Ryozo Nagai, Shuji Hatakeyama
    BMJ open 9 4 e026251  2019年04月 [査読有り][通常論文]
     
    OBJECTIVES: To investigate oral antibiotic prescribing patterns and identify factors associated with antibiotic prescriptions, with the aim of guiding future interventions to reduce inappropriate prescribing. DESIGN: Retrospective cohort study. SETTING: Database of public health insurance claims in Kumamoto prefecture (Japan). PARTICIPANTS: Beneficiaries of the national or late elders' health insurance system between April 2012 and March 2013. MAIN OUTCOME MEASURES: Of the 7 770 481 outpatient visits, 682 822 had a code for antibiotics (860 antibiotic prescriptions per 1000 population). Third-generation cephalosporins (35%), macrolides (32%) and quinolones (21%) were the most frequently prescribed. Acute respiratory tract infections (ARTIs), including viral upper respiratory infections (URI) (22%), pharyngitis (18%), bronchitis (11%) and sinusitis (10%) were the most frequently diagnosed for antibiotic prescribing, followed by gastrointestinal (9%), urinary tract (8%) and skin, cutaneous and mucosal infections (5%). Antibiotic prescribing rates for viral URI, pharyngitis, bronchitis, sinusitis and gastrointestinal infections were 35%, 54%, 53%, 57% and 30%, respectively. In multivariable analysis for ARTIs and gastrointestinal infections, patient age (10-19 years especially), patient sex (male) and facility scale (free-standing clinics or small-scale hospital-based clinics) were associated with increased antibiotic prescribing. CONCLUSIONS: Broad-spectrum antibiotics constituted 88% of oral outpatient antibiotic prescriptions. Approximately 70% of antibiotics were prescribed for ARTIs and gastroenteritis with modest benefit from antibiotic treatment. The quality of antibiotic prescribing needs to be improved. Antimicrobial stewardship interventions should target ARTIs and gastroenteritis, as well as young patients and small-scale institutions.
  • Hiroshi Itoh, Issei Komuro, Masahiro Takeuchi, Takashi Akasaka, Hiroyuki Daida, Yoshiki Egashira, Hideo Fujita, Jitsuo Higaki, Ken-Ichi Hirata, Shun Ishibashi, Takaaki Isshiki, Sadayoshi Ito, Atsunori Kashiwagi, Satoshi Kato, Kazuo Kitagawa, Masafumi Kitakaze, Takanari Kitazono, Masahiko Kurabayashi, Katsumi Miyauchi, Tomoaki Murakami, Toyoaki Murohara, Koichi Node, Susumu Ogawa, Yoshihiko Saito, Yoshihiko Seino, Takashi Shigeeda, Shunya Shindo, Masahiro Sugawara, Seigo Sugiyama, Yasuo Terauchi, Hiroyuki Tsutsui, Kenji Ueshima, Kazunori Utsunomiya, Masakazu Yamagishi, Tsutomu Yamazaki, Shoei Yo, Koutaro Yokote, Kiyoshi Yoshida, Michihiro Yoshimura, Nagahisa Yoshimura, Kazuwa Nakao, Ryozo Nagai
    Diabetes, obesity & metabolism 21 4 791 - 800 2019年04月 [査読有り][通常論文]
     
    AIMS: To assess the benefits of intensive statin therapy on reducing cardiovascular (CV) events in patients with type 2 diabetes complicated with hyperlipidaemia and retinopathy in a primary prevention setting in Japan. In the intension-to-treat population, intensive therapy [targeting LDL cholesterol <1.81 mmol/L (<70 mg/dL)] was no more effective than standard therapy [LDL cholesterol ≥2.59 to <3.10 mmol/L (≥100 to <120 mg/dL)]; however, after 3 years, the intergroup difference in LDL cholesterol was only 0.72 mmol/L (27.7 mg/dL), and targeted levels were achieved in <50% of patients. We hypothesized that the intergroup difference in CV events would have been statistically significant if more patients had been successfully treated to target. MATERIALS AND METHODS: This exploratory post hoc analysis focused on intergroup data from patients who achieved their target LDL cholesterol levels. The primary endpoint was the composite incidence of CV events. A Cox proportional hazards model was used to estimate hazard ratios (HRs) for incidence of the primary endpoint in patients who achieved target LDL cholesterol levels in each group. RESULTS: Data were analysed from 1909 patients (intensive: 703; standard: 1206) who achieved target LDL cholesterol levels. LDL cholesterol at 36 months was 1.54 ± 0.30 mmol/L (59.7 ± 11.6 mg/dL) in the intensive group and 2.77 ± 0.46 mmol/L (107.1 ± 17.8 mg/dL) in the standard group (P < 0.05). After adjusting for baseline prognostic factors, the composite incidence of CV events or deaths associated with CV events was significantly lower in the intensive than the standard group (HR 0.48; 95% confidence interval 0.28-0.82; P = 0.007). CONCLUSIONS: This post hoc analysis suggests that achieving LDL cholesterol target levels <1.81 mmol/L may more effectively reduce CV events than achieving target levels ≥2.59 to <3.10 mmol/L in patients with hypercholesterolaemia and diabetic retinopathy.
  • Tetsuya Matoba, Takahide Kohro, Hideo Fujita, Masaharu Nakayama, Arihiro Kiyosue, Yoshihiro Miyamoto, Kunihiro Nishimura, Hideki Hashimoto, Yasuaki Antoku, Naoki Nakashima, Kazuhiko Ohe, Hisao Ogawa, Hiroyuki Tsutsui, Ryozo Nagai
    International heart journal 60 2 264 - 270 2019年03月 [査読有り][通常論文]
     
    The utilization of electronic medical records and multimodal medical data is an ideal approach to build a real-time and precision registry type study with a smaller effort and cost, which may fill a gap between evidence-based medicine and the real-world clinical practice. The Japan Ischemic heart disease Multimodal Prospective data Acquisition for preCision Treatment (J-IMPACT) project aimed to build an clinical data registry system that electronically collects not only medical records, but also multimodal data, including coronary angiography and percutaneous coronary intervention (PCI) report, in standardized data formats for clinical studies.The J-IMPACT system comprises the standardized structured medical information exchange (SS-MIX), coronary angiography and intervention reporting system (CAIRS), and multi-purpose clinical data repository system (MCDRS) interconnected within the institutional network. In order to prove the concept, we acquired multimodal medical data of 6 consecutive cases that underwent PCI through the J-IMPACT system in a single center. Data items regarding patient background, laboratory data, prescriptions, and PCI/cardiac catheterization report were correctly acquired through the J-IMPACT system, and the accuracy of the multimodal data of the 4 categories was 100% in all 6 cases.The application of J-IMPACT system to clinical studies not only fills the gaps between randomized clinical trials and real-world medicine, but may also provide real-time big data that reinforces precision treatment for each patient.
  • Kazuomi Kario, Naoko Tomitani, Hiroshi Kanegae, Nobuhiko Yasui, Ryozo Nagai, Hiroshi Harada
    Journal of clinical hypertension (Greenwich, Conn.) 21 3 344 - 349 2019年03月 [査読有り][通常論文]
  • Takeshi Kimura, Satoshi Iimuro, Isao Taguchi, Hiroshi Iwata, Teruo Inoue, Yasuo Ohashi, Ryozo Nagai
    Circulation 138 23 2728 - 2729 2018年12月 [査読有り][通常論文]
  • Tsuyoshi Shiga, Takahide Kohro, Hiro Yamasaki, Kazutaka Aonuma, Atsushi Suzuki, Hiroshi Ogawa, Nobuhisa Hagiwara, Tsutomu Yamazaki, Ryozo Nagai, Hiroshi Kasanuki
    Journal of the American Heart Association 7 14 2018年07月 [査読有り][通常論文]
     
    BACKGROUND: Although an "obesity paradox" exists in patients after myocardial infarction, the association between obesity and the risk of sudden cardiac death (SCD) is limited. The aim of this study was to determine whether obesity is associated with an increased risk of SCD in Japanese survivors of acute myocardial infarction. METHODS AND RESULTS: Pooled data from 2 cohort studies in Japan, JCAD (Japanese Coronary Artery Disease) study and the Heart Institute of Japan Acute Myocardial Infarction-II (HIJAMI-II) registry, comprising of 6216 patients (mean age 65±11 years, 75.2% male) with acute myocardial infarction who were discharged alive, were studied. The patients were categorized into the following body mass index (BMI) groups at baseline according to the World Health Organization classification for Asian populations: BMI <18.5 kg/m2 (n=335), 18.5 to 23 kg/m2 (n=2371), 23 to 27.5 kg/m2 (n=2823), and ≥27.5 kg/m2 (n=687). The main outcomes were all-cause mortality and SCD. During an average follow-up period of 3.6±1.4 years, all-cause mortality was 10.1%, and SCD was 1.2%. Patients with BMI <18.5 kg/m2 had the highest rate of all-cause mortality (adjusted hazard ratio, 1.61; 95% confidence interval, 1.20-2.16), but high BMI (≥27.5 kg/m2) was not associated with mortality compared with patients in the group with BMI ≥18.5 and <23 kg/m2. However, the long-term risk of SCD was increased in the group with BMI ≥27.5 kg/m2 (adjusted hazard ratio, 2.97; 95% confidence interval, 1.24-7.15). Multivariate analysis revealed that BMI ≥27.5 kg/m2 was associated with an increased risk of SCD (hazard ratio, 2.78; 95% confidence interval, 1.35-5.74). CONCLUSIONS: Obesity (BMI ≥27.5 kg/m2) was associated with the risk of SCD in Japanese patients after myocardial infarction, although an obesity paradox was found for all-cause mortality.
  • Norifumi Takeda, Ryo Inuzuka, Sonoko Maemura, Hiroyuki Morita, Kan Nawata, Daishi Fujita, Yuki Taniguchi, Haruo Yamauchi, Hiroki Yagi, Masayoshi Kato, Hiroshi Nishimura, Yoichiro Hirata, Yuichi Ikeda, Hidetoshi Kumagai, Eisuke Amiya, Hironori Hara, Takayuki Fujiwara, Hiroshi Akazawa, Jun-Ichi Suzuki, Yasushi Imai, Ryozo Nagai, Shinichi Takamoto, Yasunobu Hirata, Minoru Ono, Issei Komuro
    Circulation. Genomic and precision medicine 11 6 e002058  2018年06月 [査読有り][通常論文]
     
    BACKGROUND: Marfan syndrome can cause life-threatening aortic complications. We investigated the relationship between FBN1 genotype and severe aortopathy (aortic root replacement, type A dissections, and related death). METHODS: We evaluated 248 patients with pathogenic or likely pathogenic FBN1 variants. The variants were classified as haploinsufficient type (HI, n=93) or dominant-negative type (DN, n=155) based on their location and predicted amino acid alterations, and we examined the effects of the FBN1 genotype on severe aortic events (aortic root replacement, type A dissections, and related death). RESULTS: The cumulative event-free probability was significantly lower in the HI group than in the DN group (adjusted hazard ratio, 2.1; 95% confidence interval, 1.4 -3.2; P<0.001). CONCLUSIONS: DN-CD+HI patients should be monitored more carefully than DN-nonCD patients for rapid development of aortic root aneurysms.
  • Hiroshi Itoh, Issei Komuro, Masahiro Takeuchi, Takashi Akasaka, Hiroyuki Daida, Yoshiki Egashira, Hideo Fujita, Jitsuo Higaki, Ken-Ichi Hirata, Shun Ishibashi, Takaaki Isshiki, Sadayoshi Ito, Atsunori Kashiwagi, Satoshi Kato, Kazuo Kitagawa, Masafumi Kitakaze, Takanari Kitazono, Masahiko Kurabayashi, Katsumi Miyauchi, Tomoaki Murakami, Toyoaki Murohara, Koichi Node, Susumu Ogawa, Yoshihiko Saito, Yoshihiko Seino, Takashi Shigeeda, Shunya Shindo, Masahiro Sugawara, Seigo Sugiyama, Yasuo Terauchi, Hiroyuki Tsutsui, Kenji Ueshima, Kazunori Utsunomiya, Masakazu Yamagishi, Tsutomu Yamazaki, Shoei Yo, Koutaro Yokote, Kiyoshi Yoshida, Michihiro Yoshimura, Nagahisa Yoshimura, Kazuwa Nakao, Ryozo Nagai
    Diabetes care 41 6 1275 - 1284 2018年06月 [査読有り][通常論文]
     
    OBJECTIVE: Diabetes is associated with high risk of cardiovascular (CV) events, particularly in patients with dyslipidemia and diabetic complications. We investigated the incidence of CV events with intensive or standard lipid-lowering therapy in patients with hypercholesterolemia, diabetic retinopathy, and no history of coronary artery disease (treat-to-target approach). RESEARCH DESIGN AND METHODS: In this multicenter, prospective, randomized, open-label, blinded end point study, eligible patients were randomly assigned (1:1) to intensive statin therapy targeting LDL cholesterol (LDL-C) <70 mg/dL (n = 2,518) or standard statin therapy targeting LDL-C 100-120 mg/dL (n = 2,524). RESULTS: Mean follow-up was 37 ± 13 months. LDL-C at 36 months was 76.5 ± 21.6 mg/dL in the intensive group and 104.1 ± 22.1 mg/dL in the standard group (P < 0.001). The primary end point events occurred in 129 intensive group patients and 153 standard group patients (hazard ratio [HR] 0.84 [95% CI 0.67-1.07]; P = 0.15). The relationship between the LDL-C difference in the two groups and the event reduction rate was consistent with primary prevention studies in patients with diabetes. Exploratory findings showed significantly fewer cerebral events in the intensive group (HR 0.52 [95% CI 0.31-0.88]; P = 0.01). Safety did not differ significantly between the two groups. CONCLUSIONS: We found no significant decrease in CV events or CV-associated deaths with intensive therapy, possibly because our between-group difference of LDL-C was lower than expected (27.7 mg/dL at 36 months of treatment). The potential benefit of achieving LDL-C <70 mg/dL in a treat-to-target strategy in high-risk patients deserves further investigation.
  • Isao Taguchi, Satoshi Iimuro, Hiroshi Iwata, Hiroaki Takashima, Mitsuru Abe, Eisuke Amiya, Takanori Ogawa, Yukio Ozaki, Ichiro Sakuma, Yoshihisa Nakagawa, Kiyoshi Hibi, Takafumi Hiro, Yoshihiro Fukumoto, Seiji Hokimoto, Katsumi Miyauchi, Tsutomu Yamazaki, Hiroshi Ito, Yutaka Otsuji, Kazuo Kimura, Jun Takahashi, Atsushi Hirayama, Hiroyoshi Yokoi, Kazuo Kitagawa, Takao Urabe, Yasushi Okada, Yasuo Terayama, Kazunori Toyoda, Takehiko Nagao, Masayasu Matsumoto, Yasuo Ohashi, Tetsuji Kaneko, Retsu Fujita, Hiroshi Ohtsu, Hisao Ogawa, Hiroyuki Daida, Hiroaki Shimokawa, Yasushi Saito, Takeshi Kimura, Teruo Inoue, Masunori Matsuzaki, Ryozo Nagai
    Circulation 137 19 1997 - 2009 2018年05月 [査読有り][通常論文]
     
    BACKGROUND: Current guidelines call for high-intensity statin therapy in patients with cardiovascular disease on the basis of several previous "more versus less statins" trials. However, no clear evidence for more versus less statins has been established in an Asian population. METHODS: In this prospective, multicenter, randomized, open-label, blinded end point study, 13 054 Japanese patients with stable coronary artery disease who achieved low-density lipoprotein cholesterol (LDL-C) <120 mg/dL during a run-in period (pitavastatin 1 mg/d) were randomized in a 1-to-1 fashion to high-dose (pitavastatin 4 mg/d; n=6526) or low-dose (pitavastatin 1 mg/d; n=6528) statin therapy. The primary end point was a composite of cardiovascular death, nonfatal myocardial infarction, nonfatal ischemic stroke, or unstable angina requiring emergency hospitalization. The secondary composite end point was a composite of the primary end point and clinically indicated coronary revascularization excluding target-lesion revascularization at sites of prior percutaneous coronary intervention. RESULTS: The mean age of the study population was 68 years, and 83% were male. The mean LDL-C level before enrollment was 93 mg/dL with 91% of patients taking statins. The baseline LDL-C level after the run-in period on pitavastatin 1 mg/d was 87.7 and 88.1 mg/dL in the high-dose and low-dose groups, respectively. During the entire course of follow-up, LDL-C in the high-dose group was lower by 14.7 mg/dL than in the low-dose group (P<0.001). With a median follow-up of 3.9 years, high-dose as compared with low-dose pitavastatin significantly reduced the risk of the primary end point (266 patients [4.3%] and 334 patients [5.4%]; hazard ratio, 0.81; 95% confidence interval, 0.69-0.95; P=0.01) and the risk of the secondary composite end point (489 patients [7.9%] and 600 patients [9.7%]; hazard ratio, 0.83; 95% confidence interval, 0.73-0.93; P=0.002). High-dose pitavastatin also significantly reduced the risks of several other secondary end points such as all-cause death, myocardial infarction, and clinically indicated coronary revascularization. The results for the primary and the secondary composite end points were consistent across several prespecified subgroups, including the low (<95 mg/dL) baseline LDL-C subgroup. Serious adverse event rates were low in both groups. CONCLUSIONS: High-dose (4 mg/d) compared with low-dose (1 mg/d) pitavastatin therapy significantly reduced cardiovascular events in Japanese patients with stable coronary artery disease. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov. Unique identifier: NCT01042730.
  • Katsumi Miyauchi, Takeshi Kimura, Hiroaki Shimokawa, Hiroyuki Daida, Satoshi Iimuro, Hiroshi Iwata, Yukio Ozaki, Ichiro Sakuma, Yoshihisa Nakagawa, Kiyoshi Hibi, Takafumi Hiro, Yoshihiro Fukumoto, Seiji Hokimoto, Yasuo Ohashi, Hiroshi Ohtsu, Yasushi Saito, Masunori Matsuzaki, Ryozo Nagai
    International heart journal 59 2 315 - 320 2018年03月 [査読有り][通常論文]
     
    Large-scale clinical trials in patients in Western countries with coronary artery disease (CAD) have found that aggressive lipid-lowering therapy using high-dose statins reduces cardiovascular (CV) events further than low-dose statins. However, such evidence has not yet been fully established in Asian populations, including in Japan. The Randomized Evaluation of Aggressive or Moderate Lipid-Lowering Therapy with Pitavastatin in Coronary Artery Disease (REAL-CAD) study addresses whether intensification of statin therapy improves clinical outcomes in Japanese patients with CAD.REAL-CAD is a prospective, multicenter, randomized, open-label, blinded-endpoint, physician-initiated phase 4 trial in Japan. The study will recruit up to 12,600 patients with stable CAD. Patients are assigned to receive either pitavastatin 1 mg/day or pitavastatin 4 mg/day. LDL-C levels are expected to reach approximate mean values of 100 mg/dL in the low-dose pitavastatin group and 80 mg/dL in the high-dose group. The primary endpoint is the time to occurrence of a major CV event, including CV death, non-fatal myocardial infarction, non-fatal ischemic stroke, and unstable angina requiring emergency hospitalization during an average of 5 years. The large number of patients and the long follow-up period in the REAL-CAD study should ensure that there is adequate power to definitively determine if reducing LDL-C levels to approximately 80 mg/dL by high-dose statin can provide additional clinical benefit.After the study is completed, we will have categorical evidence on the optimal statin dose and target LDL-C level for secondary prevention in Japanese patients.
  • Jun-Ichi Okada, Takumi Washio, Machiko Nakagawa, Masahiro Watanabe, Yoshimasa Kadooka, Taro Kariya, Hiroshi Yamashita, Yoko Yamada, Shin-Ichi Momomura, Ryozo Nagai, Toshiaki Hisada, Seiryo Sugiura
    Frontiers in physiology 9 56 - 56 2018年 [査読有り][通常論文]
     
    Background: Cardiac resynchronization therapy is an effective device therapy for heart failure patients with conduction block. However, a problem with this invasive technique is the nearly 30% of non-responders. A number of studies have reported a functional line of block of cardiac excitation propagation in responders. However, this can only be detected using non-contact endocardial mapping. Further, although the line of block is considered a sign of responders to therapy, the mechanism remains unclear. Methods: Herein, we created two patient-specific heart models with conduction block and simulated the propagation of excitation based on a cellmodel of electrophysiology. In one model with a relatively narrow QRS width (176 ms), we modeled the Purkinje network using a thin endocardial layer with rapid conduction. To reproduce a wider QRS complex (200 ms) in the second model, we eliminated the Purkinje network, and we simulated the endocardial mapping by solving the inverse problem according to the actual mapping system. Results: We successfully observed the line of block using non-contact mapping in the model without the rapid propagation of excitation through the Purkinje network, although the excitation in the wall propagated smoothly. This model of slow conduction also reproduced the characteristic properties of the line of block, including dense isochronal lines and fractionated local electrocardiograms. Further, simulation of ventricular pacing from the lateral wall shifted the location of the line of block. By contrast, in the model with the Purkinje network, propagation of excitation in the endocardial map faithfully followed the actual propagation in the wall, without showing the line of block. Finally, switching the mode of propagation between the two models completely reversed these findings. Conclusions: Our simulation data suggest that the absence of rapid propagation of excitation through the Purkinje network is the major cause of the functional line of block recorded by non-contact endocardial mapping. The line of block can be used to identify responders as these patients loose rapid propagation through the Purkinje network.
  • Yuji Nishizaki, Kazunori Shimada, Shigemasa Tani, Takayuki Ogawa, Jiro Ando, Masao Takahashi, Masato Yamamoto, Tomohiro Shinozaki, Tetsuro Miyazaki, Katsumi Miyauchi, Ken Nagao, Atsushi Hirayama, Michihiro Yoshimura, Issei Komuro, Ryozo Nagai, Hiroyuki Daida
    Tobacco induced diseases 16 08 - 08 2018年 [査読有り][通常論文]
     
    INTRODUCTION: The association among smoking history, eicosapentaenoic acid (EPA) to arachidonic acid (AA) ratio and acute coronary syndrome (ACS) is yet to be investigated. The present study aimed to clarify the association between the EPA/AA ratio and ACS prevalence in patients admitted to the cardiology department based on their smoking history. METHODS: We enrolled 1733 patients from five cardiology divisions located in Tokyo, Japan, and measured their levels of polyunsaturated fatty acids, including EPA and AA, from January 2004 to May 2011. We assessed the association between the EPA/AA ratio and ACS in the subgroups stratified according to smoking history (never, former, current smokers) using multivariate logistic models. RESULTS: A high EPA/AA ratio was significantly associated with decreased odds of ACS among patients without a smoking history (adjusted odds ratio AOR=0.20, 95% CI: 0.04-0.86) but not in patients with a smoking history (former smoker, AOR=1.50, 95% CI: 0.44-5.03; current smoker, AOR=3.73, 95% CI: 0.34-40.6). CONCLUSIONS: The EPA/AA ratio and ACS occurrence were found to be significantly associated in patients without a smoking history; however, no such association existed in patients with a smoking history. ABBREVIATIONS: AA: arachidonic acid, ACS: acute coronary syndrome, CVD: cardiovascular disease, DGLA: dihomo-gamma-linolenic acid, DHA: docosahexaenoic acid, EPA: eicosapentaenoic acid, JELIS: Japan EPA Lipid Intervention Study, PUFA: polyunsaturated fatty acid, RAS: renin angiotensin system, TG: triglyceride.
  • Takeshi Kimura, Teruo Inoue, Isao Taguchi, Hiroshi Iwata, Satoshi Iimuro, Takafumi Hiro, Yoshihisa Nakagawa, Yukio Ozaki, Yasuo Ohashi, Hiroyuki Daida, Hiroaki Shimokawa, Ryozo Nagai
    CIRCULATION 136 24 E450 - E451 2017年12月 [査読有り][通常論文]
  • 交感神経遮断のマウス脈絡膜新生血管およびマクロファージの眼内浸潤に及ぼす影響
    譚 雪, 藤生 克仁, 真鍋 一郎, 西田 淳子, 山岸 麗子, 永井 良三, 柳 靖雄
    眼科臨床紀要 10 11 921 - 921 眼科臨床紀要会 2017年11月
  • Takuya Azami, Tsuyoshi Waku, Ken Matsumoto, Hyojung Jeon, Masafumi Muratani, Akihiro Kawashima, Jun Yanagisawa, Ichiro Manabe, Ryozo Nagai, Tilo Kunath, Tomonori Nakamura, Kazuki Kurimoto, Mitinori Saitou, Satoru Takahashi, Masatsugu Ema
    Development (Cambridge, England) 144 20 3706 - 3718 2017年10月 [査読有り][通常論文]
     
    The inner cell mass of the mouse blastocyst gives rise to the pluripotent epiblast (EPI), which forms the embryo proper, and the primitive endoderm (PrE), which forms extra-embryonic yolk sac tissues. All inner cells coexpress lineage markers such as Nanog and Gata6 at embryonic day (E) 3.25, and the EPI and PrE precursor cells eventually segregate to exclusively express Nanog and Gata6, respectively. Fibroblast growth factor (FGF)-extracellular signal-regulated kinase (ERK) signalling is involved in segregation of the EPI and PrE lineages; however, the mechanism involved in Fgf4 regulation is poorly understood. Here, we identified Klf5 as an upstream repressor of Fgf4Fgf4 was markedly upregulated in Klf5 knockout (KO) embryos at E3.0, and was downregulated in embryos overexpressing Klf5 Furthermore, Klf5 KO and overexpressing blastocysts showed skewed lineage specification phenotypes, similar to FGF4-treated preimplantation embryos and Fgf4 KO embryos, respectively. Inhibitors of the FGF receptor (Fgfr) and ERK pathways reversed the skewed lineage specification of Klf5 KO blastocysts. These data demonstrate that Klf5 suppresses Fgf4-Fgfr-ERK signalling, thus preventing precocious activation of the PrE specification programme.
  • Jun-Ichi Okada, Takumi Washio, Machiko Nakagawa, Masahiro Watanabe, Yoshimasa Kadooka, Taro Kariya, Hiroshi Yamashita, Yoko Yamada, Shin-Ichi Momomura, Ryozo Nagai, Toshiaki Hisada, Seiryo Sugiura
    Journal of molecular and cellular cardiology 108 17 - 23 2017年07月 [査読有り][通常論文]
     
    BACKGROUND: The currently proposed criteria for identifying patients who would benefit from cardiac resynchronization therapy (CRT) still need to be optimized. A multi-scale heart simulation capable of reproducing the electrophysiology and mechanics of a beating heart may help resolve this problem. The objective of this retrospective study was to test the capability of patient-specific simulation models to reproduce the response to CRT by applying the latest multi-scale heart simulation technology. METHODS AND RESULTS: We created patient-specific heart models with realistic three-dimensional morphology based on the clinical data recorded before treatment in nine patients with heart failure and conduction block treated by biventricular pacing. Each model was tailored to reproduce the surface electrocardiogram and hemodynamics of each patient in formats similar to those used in clinical practice, including electrocardiography (ECG), echocardiography, and hemodynamic measurements. We then performed CRT simulation on each heart model according to the actual pacing protocol and compared the results with the clinical data. CRT simulation improved the ECG index and diminished wall motion dyssynchrony in each patient. These results, however, did not correlate with the actual response. The best correlation was obtained between the maximum value of the time derivative of ventricular pressure (dP/dtmax) and the clinically observed improvement in the ejection fraction (EF) (r=0.94, p<0.01). CONCLUSIONS: By integrating the complex pathophysiology of the heart, patient-specific, multi-scale heart simulation could successfully reproduce the response to CRT. With further verification, this technique could be a useful tool in clinical decision making.
  • Ken Fujiwara, Megumi Yatabe, Alimuddin Tofrizal, Depicha Jindatip, Takashi Yashiro, Ryozo Nagai
    Cell and tissue research 368 2 371 - 378 2017年05月 [査読有り][通常論文]
     
    Macrophages are present throughout the anterior pituitary gland. However, the features and function of macrophages in the gland are poorly understood. Recent studies have indicated that there are two main macrophage classes: M1 (classically activated) and M2 (alternatively activated). In this study, we examine whether both M1 and M2 macrophages are present in the anterior pituitary gland of rats. Our findings indicate that macrophages that are positive for CD68 (a pan-macrophage marker) were localized near capillaries in rat anterior pituitary gland. These macrophages were positive for iNOS or mannose receptor (MR), which are markers of M1 and M2 macrophages, respectively. To determine the morphological characteristics of M2 macrophages under pathological conditions, diethylstilbestrol (DES)-treated rats were used as an animal model of prolactinoma. After 2 weeks of DES treatment, a number of MR-immunopositive cells were present in the gland. Immunoelectron microscopy revealed that MR-immunopositive M2 macrophages had many small vesicles and moderately large vacuoles in cytoplasm. Phagosomes were sometimes present in cytoplasm. Interestingly, M2 macrophages in prolactinoma tissues did not usually exhibit distinct changes or differences during the normal, hyperplasia and adenoma stages. This study is the first to confirm that both M1 and M2 macrophages are present in the anterior pituitary gland of rats. Moreover, the number of M2 macrophages was greatly increased in rats with DES-induced prolactinoma. Future studies should attempt to characterize the functional role of M2 macrophages in the gland.
  • Katsuhito Fujiu, Munehiko Shibata, Yukiteru Nakayama, Fusa Ogata, Sahohime Matsumoto, Koji Noshita, Shingo Iwami, Susumu Nakae, Issei Komuro, Ryozo Nagai, Ichiro Manabe
    Nature medicine 23 5 611 - 622 2017年05月 [査読有り][通常論文]
     
    Heart failure is a complex clinical syndrome characterized by insufficient cardiac function. In addition to abnormalities intrinsic to the heart, dysfunction of other organs and dysregulation of systemic factors greatly affect the development and consequences of heart failure. Here we show that the heart and kidneys function cooperatively in generating an adaptive response to cardiac pressure overload. In mice subjected to pressure overload in the heart, sympathetic nerve activation led to activation of renal collecting-duct (CD) epithelial cells. Cell-cell interactions among activated CD cells, tissue macrophages and endothelial cells within the kidney led to secretion of the cytokine CSF2, which in turn stimulated cardiac-resident Ly6Clo macrophages, which are essential for the myocardial adaptive response to pressure overload. The renal response to cardiac pressure overload was disrupted by renal sympathetic denervation, adrenergic β2-receptor blockade or CD-cell-specific deficiency of the transcription factor KLF5. Moreover, we identified amphiregulin as an essential cardioprotective mediator produced by cardiac Ly6Clo macrophages. Our results demonstrate a dynamic interplay between the heart, brain and kidneys that is necessary for adaptation to cardiac stress, and they highlight the homeostatic functions of tissue macrophages and the sympathetic nervous system.
  • Masao Takahashi, Jiro Ando, Kazunori Shimada, Yuji Nishizaki, Shigemasa Tani, Takayuki Ogawa, Masato Yamamoto, Ken Nagao, Atsushi Hirayama, Michihiro Yoshimura, Hiroyuki Daida, Ryozo Nagai, Issei Komuro
    BMC cardiovascular disorders 17 1 41 - 41 2017年01月 [査読有り][通常論文]
     
    BACKGROUND: In prior myocardial infarction (PMI) patients, diabetes mellitus (DM), dyslipidemia, and hypertension increase the risk of secondary cardiovascular events. Although a decreased ratio of serum eicosapentaenoic acid (EPA) to arachidonic acid (AA; EPA/AA) has been shown to significantly correlate with the onset of acute coronary syndrome, the associations between polyunsaturated fatty acid (PUFA) levels and coronary risk factors in PMI patients have not been evaluated thoroughly. This study aimed to assess the associations between PUFAs levels and the risk factors in PMI patients. METHODS: We enrolled 1733 patients with known PUFA levels who were treated in five divisions of cardiology in a metropolitan area of Japan, including 303 patients with PMI. EPA/AA and docosahexaenoic acid (DHA) to AA level ratio (DHA/AA) in patients with and without PMI were analyzed according to presence of coronary risk factors. RESULTS: Diabetes patients with PMI had significantly lower EPA/AA and DHA/AA than diabetes patients without PMI (EPA/AA: P <0.01; DHA/AA: P =0.003), with no such differences in dyslipidemia and hypertension patients. In DM patients with high high-sensitivity C-reactive protein (hs-CRP) levels (>0.1 mg/dL), EPA/AA was low in individuals who also had PMI, whereas DHA/AA was not (EPA/AA, with PMI: 0.43 ± 0.24; without PMI: 0.53 ± 0.30, P < 0.05). Moreover, patients on statins had significantly lower DHA/AA ratios, whereas the EPA/AA ratio did not depend on statin use. Multiple regression analysis revealed that statin use in DM patients was associated with low DHA/AA but not EPA/AA. CONCLUSION: PMI patients with DM have low EPA/AA and DHA/AA. EPA/AA and DHA/AA are differently related to hs-CRP level in DM patients with PMI. Statin use can potentially affect DHA/AA but not EPA/AA, and therefore EPA/AA ratio is a better marker of assessment for cardiovascular events.
  • Taro Kariya, Yasushi Imai, Katsuhito Fujiu, Ryozo Nagai
    journal of arrhythmia 27 4 302  2017年 [査読有り][通常論文]
     
    Electrocardiogram (ECG) is one of the most basic examinations in the clinical medicine. Although frequently used, the interpretation of a standard 12-lead ECG is sometimes difficult for not only beginners but also clinical cardiologists. Vectorcardiogram (VCG) had been frequently used for describing three-dimensional movement of cardiac electrical activity before 1990s, which was thereafter rarely used in the clinical settings due to its complexity and time-consuming nature. However, VCG still has many features including: (1) easy for spatial understanding, chronologically normalized, and (3) easy for quantitative analysis. For several years, we have collaborated with Fukuda Denshi Co., Ltd. and have established the novel vectorcardiographic descriptor of ventricular electrical activation, which digitally converts standard 12- lead ECG waveforms into “synthesized” VCG QRS-loop drawing. This novel vectorcardiographic descriptor can help us to understand the abnormality of QRS complex such as bundle branch blocks, ventricular hypertrophies, and myocardial injury: adding this synthesized VCG report to conventional 12-lead ECG report, healthcare providers and students are able to diagnose abnormality of QRS complex in ECG more effectively and accurately. Now this system can be optionally installed into the conventional ECG system (Fukuda Denshi Co., Ltd., Japan). This descriptor has great potential to clinical efficacy as well as medical education, and can make us revisit the VCG. © 2011, Japanese Heart Rhythm Society. All rights reserved.
  • Hisashi Kai, Takahide Kohro, Kenji Fukuda, Tsutomu Yamazaki, Ryozo Nagai
    International journal of cardiology 224 112 - 113 2016年12月 [査読有り][通常論文]
  • Hirofumi Zempo, Jun-Ichi Suzuki, Masahito Ogawa, Ryo Watanabe, Katsuhito Fujiu, Ichiro Manabe, Simon J Conway, Yoshiaki Taniyama, Ryuichi Morishita, Yasunobu Hirata, Mitsuaki Isobe, Ryozo Nagai
    Hypertension research : official journal of the Japanese Society of Hypertension 39 11 764 - 768 2016年11月 [査読有り][通常論文]
     
    Chronic hypertension causes vascular remodeling that is associated with an increase in periostin- (postn) positive cells, including fibroblasts and smooth muscle cells. Krüppel-like factor (KLF) 5, a transcription factor, is also observed in vascular remodeling; however, it is unknown what role KLF5 plays in postn-positive cells during vascular remodeling induced by deoxycorticosterone-acetate (DOCA) salt. We used postn-positive cell-specific Klf5-deficient mice (Klf5PostnKO: Klf5flox/flox; PostnCre/-) and wild-type mice (WT: Klf5flox/flox; Postn-/-). We implanted a DOCA pellet and provided drinking water containing 0.9% NaCl for 8 weeks. The DOCA-salt treatment induced hypertension in both genotypes, as observed by increases in systolic blood pressure. In WT animals, DOCA-salt treatment increased the aortic medial area compared with the non-treated controls. Similarly, Tgfb1 was overexpressed in the aortas of the DOCA-salt treated WT mice compared with the controls. Immunofluorescence staining revealed that fibroblast-specific protein 1 (FSP1)+-α smooth muscle actin (αSMA)+ myofibroblasts exist in the medial area of the WT aortas after DOCA-salt intervention. Importantly, these changes were not observed in the Klf5PostnKO animals. In conclusion, the results of this study suggest that the presence of KLF5 in postn-positive cells contributes to the pathogenesis of aortic thickening induced by DOCA-salt hypertension.
  • Yoshinori Takeuchi, Naoya Yahagi, Yuichi Aita, Yuki Murayama, Yoshikazu Sawada, Xiaoying Piao, Naoki Toya, Yukari Oya, Akito Shikama, Ayako Takarada, Yukari Masuda, Makiko Nishi, Midori Kubota, Yoshihiko Izumida, Takashi Yamamoto, Motohiro Sekiya, Takashi Matsuzaka, Yoshimi Nakagawa, Osamu Urayama, Yasushi Kawakami, Yoko Iizuka, Takanari Gotoda, Keiji Itaka, Kazunori Kataoka, Ryozo Nagai, Takashi Kadowaki, Nobuhiro Yamada, Yuan Lu, Mukesh K Jain, Hitoshi Shimano
    Cell reports 16 9 2373 - 86 2016年08月 [査読有り][通常論文]
     
    Hepatic lipogenesis is nutritionally regulated (i.e., downregulated during fasting and upregulated during the postprandial state) as an adaptation to the nutritional environment. While alterations in the expression level of the transcription factor SREBP-1c are known to be critical for nutritionally regulated lipogenesis, upstream mechanisms governing Srebf1 expression remain unclear. Here, we show that the fasting-induced transcription factor KLF15, a key regulator of gluconeogenesis, forms a complex with LXR/RXR, specifically on the Srebf1 promoter. This complex recruits the corepressor RIP140 instead of the coactivator SRC1, resulting in reduced Srebf1 and thus downstream lipogenic enzyme expression during the early and euglycemic period of fasting prior to hypoglycemia and PKA activation. Through this mechanism, KLF15 overexpression specifically ameliorates hypertriglyceridemia without affecting LXR-mediated cholesterol metabolism. These findings reveal a key molecular link between glucose and lipid metabolism and have therapeutic implications for the treatment of hyperlipidemia.
  • Yuji Nishizaki, Kazunori Shimada, Shigemasa Tani, Takayuki Ogawa, Jiro Ando, Masao Takahashi, Masato Yamamoto, Tomohiro Shinozaki, Tetsuro Miyazaki, Katsumi Miyauchi, Ken Nagao, Atsushi Hirayama, Michihiro Yoshimura, Issei Komuro, Ryozo Nagai, Hiroyuki Daida
    BMC cardiovascular disorders 16 1 143 - 143 2016年07月 [査読有り][通常論文]
     
    BACKGROUND: A low eicosapentaenoic acid (EPA) to arachidonic acid (AA) ratio is a known risk for acute coronary syndrome (ACS). However, the association between the docosahexaenoic acid (DHA) to AA ratio and ACS remains unclear. This study aimed to assess the association between the DHA/AA ratio and ACS by patient characteristics. METHODS: We enrolled 1733 patients and evaluated the serum levels of polyunsaturated fatty acids in 5 cardiology departments in a metropolitan area of Japan. We assessed the relationship between the DHA/AA ratio (median cut-off value: 0.903) and ACS according to the following 10 subgroups: sex, age, diabetes mellitus, hypertension, dyslipidemia, smoking history, family history of ischemic heart disease, chronic kidney disease, obesity, and history of coronary revascularization. RESULTS: Interaction tests in the 10 subgroup analyses revealed a significant difference for adjusted log odds ratios between male and females (p = 0.01), and those with and without hypertension (p = 0.06). Especially in the subgroup based on sex difference, a high DHA/AA ratio was significantly associated with a low risk of ACS among men (adjusted odds ratio = 0.389; 95 % confidence interval: 0.211-0.716). In contrast, a reverse association was found among women, although this was not statistically significant (adjusted odds ratio = 3.820; 95 % confidence interval: 0.718-20.325). CONCLUSIONS: The association between the DHA/AA ratio and ACS differed by clinical characteristic. Notably, patients with a low DHA/AA ratio had a higher risk of ACS than those with a high DHA/AA ratio, and this was significant for men in particular.
  • Hiroaki Semba, Norihiko Takeda, Takayuki Isagawa, Yuki Sugiura, Kurara Honda, Masaki Wake, Hidenobu Miyazawa, Yoshifumi Yamaguchi, Masayuki Miura, Dana M R Jenkins, Hyunsung Choi, Jung-Whan Kim, Masataka Asagiri, Andrew S Cowburn, Hajime Abe, Katsura Soma, Katsuhiro Koyama, Manami Katoh, Keimon Sayama, Nobuhito Goda, Randall S Johnson, Ichiro Manabe, Ryozo Nagai, Issei Komuro
    Nature communications 7 11635 - 11635 2016年05月 [査読有り][通常論文]
     
    In severely hypoxic condition, HIF-1α-mediated induction of Pdk1 was found to regulate glucose oxidation by preventing the entry of pyruvate into the tricarboxylic cycle. Monocyte-derived macrophages, however, encounter a gradual decrease in oxygen availability during its migration process in inflammatory areas. Here we show that HIF-1α-PDK1-mediated metabolic changes occur in mild hypoxia, where mitochondrial cytochrome c oxidase activity is unimpaired, suggesting a mode of glycolytic reprogramming. In primary macrophages, PKM2, a glycolytic enzyme responsible for glycolytic ATP synthesis localizes in filopodia and lammelipodia, where ATP is rapidly consumed during actin remodelling processes. Remarkably, inhibition of glycolytic reprogramming with dichloroacetate significantly impairs macrophage migration in vitro and in vivo. Furthermore, inhibition of the macrophage HIF-1α-PDK1 axis suppresses systemic inflammation, suggesting a potential therapeutic approach for regulating inflammatory processes. Our findings thus demonstrate that adaptive responses in glucose metabolism contribute to macrophage migratory activity.
  • Hong Zhan, Kenichi Aizawa, Junqing Sun, Shota Tomida, Kinya Otsu, Simon J Conway, Peter J Mckinnon, Ichiro Manabe, Issei Komuro, Kiyoshi Miyagawa, Ryozo Nagai, Toru Suzuki
    Cardiovascular research 110 1 85 - 95 2016年05月 [査読有り][通常論文]
     
    AIMS: Doxorubicin (Dox) is a potent anticancer agent that is widely used in the treatment of a variety of cancers, but its usage is limited by cumulative dose-dependent cardiotoxicity mainly due to oxidative damage. Ataxia telangiectasia mutated (ATM) kinase is thought to play a role in mediating the actions of oxidative stress. Here, we show that ATM in cardiac fibroblasts is essential for Dox-induced cardiotoxicity. METHODS AND RESULTS: ATM knockout mice showed attenuated Dox-induced cardiotoxic effects (e.g. cardiac dysfunction, apoptosis, and mortality). As ATM was expressed and activated predominantly in cardiac fibroblasts, fibroblast-specific Atm-deleted mice (Atm(fl/fl);Postn-Cre) were generated to address cell type-specific effects, which showed that the fibroblast is the key lineage mediating Dox-induced cardiotoxicity through ATM. Mechanistically, ATM activated the Fas ligand, which subsequently regulated apoptosis in cardiomyocytes at later stages. Therapeutically, a potent and selective inhibitor of ATM, KU55933, when administered systemically was able to prevent Dox-induced cardiotoxicity. CONCLUSION: ATM-regulated effects within cardiac fibroblasts are pivotal in Dox-induced cardiotoxicity, and antagonism of ATM and its functions may have potential therapeutic implications.
  • Aiko Sakamoto, Nobukazu Ishizaka, Yasushi Imai, Masae Uehara, Jiro Ando, Ryozo Nagai, Issei Komuro
    Journal of cardiology 67 3 254 - 61 2016年03月 [査読有り][通常論文]
     
    BACKGROUND: Immunoglobulin G4 (IgG4)-related immuno-inflammation has been suggested to affect the development of coronary artery atherosclerosis. The aim of this study was to analyze the association of serum IgG4 concentrations with calcified and non-calcified coronary plaques. METHODS: Serum IgG4 concentrations were measured in 263 patients who underwent 320-slice coronary computed tomographic (CT) angiography. Vulnerable coronary plaques were evaluated for CT plaque characteristics, including low-density plaque (LDP), positive remodeling, and spotty calcification. RESULTS: Serum concentrations of IgG4 were significantly higher in patients with non-calcified plaque (NCP) than in those without (32.2mg/dL vs. 23.7mg/dL, p=0.029). By contrast, the median serum IgG4 concentrations in patients with and without calcified plaque were 31.2mg/dL and 26.2mg/dL, respectively (p=0.107). Serum IgG4 concentrations were significantly elevated in patients with LDP (33.5mg/dL vs. 26.9mg/dL, p=0.002) and in those with positive remodeling (31.4mg/dL vs. 28.4mg/dL, p=0.039) than in those without. Patients with spotty calcification also had significantly higher serum IgG4 concentrations than those without (32.1mg/dL vs. 24.9mg/dL, p=0.049). In age- and gender-adjusted logistic regression analysis, the highest IgG4 quartile (≥56.7mg/dL) was significantly associated with LDP with an odds ratio of 2.49 (95% CI, 1.15-5.36, p=0.020). CONCLUSIONS: Serum IgG4 concentrations were significantly associated with NCP, especially with LDP, suggesting that IgG4-related immuno-inflammation may play a role in coronary plaque vulnerability.
  • Fusa Ogata, Katsuhito Fujiu, Sahohime Matsumoto, Yukiteru Nakayama, Munehiko Shibata, Yuichi Oike, Isao Koshima, Tetsuro Watabe, Ryozo Nagai, Ichiro Manabe
    The Journal of investigative dermatology 136 3 706 - 714 2016年03月 [査読有り][通常論文]
     
    Lymphedema is a debilitating progressive condition that severely restricts quality of life and is frequently observed after cancer surgery. The mechanism underlying lymphedema development remains poorly understood, and no effective pharmacological means to prevent or alleviate the ailment is currently available. Using a mouse model of lymphedema, we show here that excessive generation of immature lymphatic vessels is essential for initial edema development and that this early process is also important for later development of lymphedema pathology. We found that CD4(+) T cells interact with macrophages to promote lymphangiogenesis, and that both lymphangiogenesis and edema were greatly reduced in macrophage-depleted mice, lymphocyte-deficient Rag2(?/?) mice or CD4(+) T-cell-deficient mice. Mechanistically, T helper type 1 and T helper type 17 cells activate lesional macrophages to produce vascular endothelial growth factor-C, which promotes lymphangiogenesis, and inhibition of this mechanism suppressed not only early lymphangiogenesis, but also later development of lymphedema. Finally, we show that atorvastatin suppresses excessive lymphangiogenesis and lymphedema by inhibiting T helper type 1 and T helper type 17 cell activation. These results demonstrate that the interaction between CD4(+) T cells and macrophages is a potential therapeutic target for prevention of lymphedema after surgery.
  • Xue Tan, Katsuhito Fujiu, Ichiro Manabe, Junko Nishida, Reiko Yamagishi, Yuya Terashima, Kouji Matsushima, Toshikatsu Kaburaki, Ryozo Nagai, Yasuo Yanagi
    PloS one 11 8 e0160985  2016年 [査読有り][通常論文]
     
    PURPOSE: To determine the involvement of sympathetic activity in choroidal neovascularization (CNV) using laser-induced CNV in a mouse model. METHODS: We investigated changes in the proportions of intraocular lymphocytes, granulocytes, and three macrophage subtypes (Ly6Chi, Ly6Cint, and Ly6Clo) after laser injury in mice using flow cytometry, and evaluated CNV lesion size in mice lacking inflammatory cells. Further, we evaluated the lesion size in mice administered the β3 receptor antagonist, splenic-denervated and splenectomized mice. We also assessed changes in the proportions of intraocular macrophages and peripheral blood monocytes in splenic-denervated and splenectomized mice. Lastly, lesion size was compared between splenic-denervated mice with or without adoptive transfer of macrophages following laser injury. After Ly5.1 mice spleen-derived Ly6Chi cells were transferred into Ly5.2 mice, the proportions of intraocular Ly5.1+Ly6Chi cells were compared. RESULTS: In WT mice, the proportion of CD4+ T cells recruited into the eye increased progressively from day 3 to day 7 after laser injury, whereas, intraocular CD8+ T cells did not change significantly. Proportions of B220+ cells, granulocytes, and two subtypes of intraocular macrophages (Ly6Chi and Ly6Clo) peaked at day 3 following laser injury. In contrast, Ly6Cint/loCD64+ subtype showed a significantly higher percentage at day 7 after laser injury. There were no differences in lesion size between CD4-/-or Rag2-/-mice and controls, whereas lesion size was significantly reduced in CCR2-/- mice and clodronate liposome-treated mice. CNV lesion area was significantly reduced in mice with β3 blocker treatment, splenic-denervated and splenectomized mice compared with controls. Intraocular Ly6Chi macrophages were also reduced by splenic denervation or splenectomy. Adoptive transfer of spleen-derived Ly6Chi cells increased the lesion size in splenic-denervated mice. Compared with controls, intraocular donor-derived Ly6Chi cells recruited into the eye were reduced in splenic-denervated and splenectomized mice. CONCLUSIONS: Although lymphocytes had little effect on CNV formation, Ly6Chi macrophages/monocytes exacerbated CNV in mice. Sympathetic activity might contribute to CNV via the recruitment of macrophages to the eye.
  • Kenji Ueshima, Hiroshi Itoh, Nobuaki Kanazawa, Issei Komuro, Ryozo Nagai, Masahiro Takeuchi, Tsutomu Yamazaki
    Journal of Atherosclerosis and Thrombosis 23 8 976 - 990 2016年 [査読無し][通常論文]
     
    Aim: Hyperlipidemia and diabetic retinopathy increase the risk of cardiovascular disease (CVD). The standard versus intEnsive statin therapy for hypercholesteroleMic Patients with diAbetic retinopaTHY (EMPATHY) study examines whether intensive lipid-lowering therapy is superior to standard therapy in reducing the incidence of cardiovascular events in patients with hyperlipidemia and diabetic retinopathy, but without a history of coronary artery disease. Methods: Patients who had elevated low-density lipoprotein cholesterol (LDL-C) and diabetic retinopathy without a history of coronary artery disease were eligible for the study. Patients were randomly assigned in a 1:1 ratio to receive intensive or standard therapy. Patients are being treated with monotherapy with 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitor (statin) for a maximum of 5.5 years to achieve the following LDL-C target: < 70 mg/dL for the intensive therapy group or ≥ 100 and < 120 mg/dL for the standard therapy group. The primary endpoint is a composite of incidence of CVD and death from CVD. Results: Between May 2010 and October 2013, 5,995 patients were assessed for eligibility, and 5,144 were assigned to the study treatment (2,571 and 2,573 in the intensive and standard therapy groups, respectively), and baseline data were analyzed from 5,107 (2,550 in the intensive therapy group and 2,557 in the standard therapy group). Conclusions: This is the first study assessing the benefits of intensive statin therapy in patients with hypercholesterolemia and diabetic retinopathy in a primary prevention setting. Furthermore, this study evaluates the appropriateness of the treat-to-target approach because all patients are treated to achieve specific LDL-C targets by titrating statin therapy. Clinical Trial Registration Number: UMIN000003486.
  • Xue Tan, Katsuhito Fujiu, Ichiro Manabe, Junko Nishida, Reiko Yamagishi, Ryozo Nagai, Yasuo Yanagi
    Scientific reports 5 15702 - 15702 2015年10月 [査読有り][通常論文]
     
    In early age-related macular degeneration (AMD), complement component C3 can be observed in drusen, which is the accumulation of material beneath the retinal pigment epithelium. The complement pathways, via the activation of C3, can upregulate the expression of cytokines and their receptors and the recruitment of inflammatory leukocytes, both of which play an important role in the development of choroidal neovascularization (CNV) in exudative AMD. Laser-induced CNV lesions were found to be significantly smaller in C3(-/-) mice than in wild-type mice. By using flow cytometry, we demonstrated that the proportions of intraocular granulocytes, CD11b(+)F4/80(+)Ly6C(hi) and CD11b(+)F4/80(+)Ly6C(lo) cells, were lower in C3(-/-) mice than in wild-type mice as early as day 1 after laser injury, and the proportions of granulocytes and three macrophage/monocyte subsets were significantly lower on day 3. In contrast, C3(-/-) mice had more granulocytes and CD11b(+)F4/80(+)Ly6C(hi) cells in peripheral blood than wild-type mice after injury. Further, the expression levels of Vegfa164 were upregulated in intraocular Ly6C(hi) macrophages/monocytes of C3(-/-) mice, but not as much as in wild-type mice. Collectively, our data demonstrate that despite a more pronounced induction of systemic inflammation, inhibition of complement factor C3 suppresses CNV by decreasing the recruitment of inflammatory cells to the lesion.
  • Yasushi Imai, Hiroyuki Morita, Norifumi Takeda, Fuyuki Miya, Hironobu Hyodo, Daishi Fujita, Tomoyuki Tajima, Tatsuhiko Tsunoda, Ryozo Nagai, Michiaki Kubo, Issei Komuro
    International journal of cardiology 195 290 - 2 2015年09月 [査読有り][通常論文]
  • Daigo Sawaki, Lianguo Hou, Shota Tomida, Junqing Sun, Hong Zhan, Kenichi Aizawa, Bo-Kyung Son, Taro Kariya, Eiki Takimoto, Kinya Otsu, Simon J Conway, Ichiro Manabe, Issei Komuro, Scott L Friedman, Ryozo Nagai, Toru Suzuki
    Cardiovascular research 107 4 420 - 30 2015年09月 [査読有り][通常論文]
     
    AIMS: Krüppel-like factors (KLFs) are a family of transcription factors which play important roles in the heart under pathological and developmental conditions. We previously identified and cloned Klf6 whose homozygous mutation in mice results in embryonic lethality suggesting a role in cardiovascular development. Effects of KLF6 on pathological regulation of the heart were investigated in the present study. METHODS AND RESULTS: Mice heterozygous for Klf6 resulted in significantly diminished levels of cardiac fibrosis in response to angiotensin II infusion. Intriguingly, a similar phenotype was seen in cardiomyocyte-specific Klf6 knockout mice, but not in cardiac fibroblast-specific knockout mice. Microarray analysis revealed increased levels of the extracellular matrix factor, thrombospondin 4 (TSP4), in the Klf6-ablated heart. Mechanistically, KLF6 directly suppressed Tsp4 expression levels, and cardiac TSP4 regulated the activation of cardiac fibroblasts to regulate cardiac fibrosis. CONCLUSION: Our present studies on the cardiac function of KLF6 show a new mechanism whereby cardiomyocytes regulate cardiac fibrosis through transcriptional control of the extracellular matrix factor, TSP4, which, in turn, modulates activation of cardiac fibroblasts.
  • Jun-Ichi Suzuki, Yasushi Imai, Mieko Aoki, Daishi Fujita, Norio Aoyama, Yuko Tada, Hiroshi Akazawa, Yuichi Izumi, Mitsuaki Isobe, Issei Komuro, Ryozo Nagai, Yasunobu Hirata
    Heart and vessels 30 5 692 - 5 2015年09月 [査読有り][通常論文]
     
    Marfan syndrome (MFS) is a systemic connective tissue disorder caused by mutations in the extracellular matrix protein fibrillin-1. While it is known that patients with MFS are at high risk of dental disorders and cardiovascular diseases, little information has been provided to date. To clarify the prevalence of periodontitis in patients with MFS, their oral condition and cardiovascular complications were evaluated. The subjects were patients with MFS (n = 40) who attended the University of Tokyo hospital; age- and gender-matched healthy individuals (n = 14) constituted a control group. Cardiovascular complications and full-mouth clinical measurements, including number of teeth, probing of pocket depth (PD), bleeding on probing (BOP), and community periodontal index (CPI) were recorded. MFS patients had more frequent cardiovascular complications (95 %) compared with the controls (0 %). MFS patients had periodontitis (CPI 3 and 4) more frequently (87.5 %) than the age- and gender-matched control subjects (35.7 %). Furthermore, MFS patients had significantly more severe periodontitis (CPI 2.90 ± 0.12 vs 1.64 ± 0.32) and fewer remaining teeth (26.7 ± 0.4 vs 28.4 ± 0.4) compared with the controls. However, PD and BOP were comparable between MFS patients and the control group. A high incidence of periodontitis and cardiovascular complications was observed in Japanese MFS patients.
  • Koichi Kimura, Masao Daimon, Hiroyuki Morita, Takayuki Kawata, Tomoko Nakao, Tomoko Okano, Seitetsu L Lee, Katsu Takenaka, Ryozo Nagai, Yutaka Yatomi, Issei Komuro
    International heart journal 56 3 349 - 53 2015年05月 [査読有り][通常論文]
     
    Speckle tracking echocardiography (STE) has been reported to be a promising technique for evaluating right ventricular (RV) function in the clinical setting. On the other hand, the usefulness of STE for RV evaluation in small animal models has not been clarified, although the rat model is among the most commonly used animal models to develop novel effective treatments against pulmonary hypertension and RV heart failure (HF).We validated the use of STE and conventional echocardiographic variables for evaluating RV functions in a rat model by comparing the echocardiographic values of RVHF rats (n = 12) induced by monocrotaline injection with those of control rats (n = 12).Most conventional echocardiographic variables demonstrated that RVHF rats have significant RV dysfunction. The area under the curve (AUC) values to distinguish RV dysfunction in RVHF rats from normal RV function in control rats using fractional area change (FAC), tricuspid annular plane systolic excursion (TAPSE), RV myocardial performance index (MPI), peak tissue Doppler tricuspid annular velocities at systole (Sa), and at early diastole (Ea) were 0.71, 0.98, 0.79, 0.92, and 0.91, respectively. However, using STE analysis for RV evaluation, limited reproducibility was observed (variability 19-37 %, ICC 0.74-0.88) and the only circumferential strain showed significantly lower absolute values (P = 0.039, AUC = 0.76).To evaluate RV function in rat models, circumferential strain may be useful, however, the reproducibility and diagnostic utility were limited. Conventional echocardiographic variables such as TAPSE, tissue Doppler Sa, and Ea have superior diagnostic utility.
  • Satoshi Nishimura, Mika Nagasaki, Shinji Kunishima, Akira Sawaguchi, Asuka Sakata, Hiroyasu Sakaguchi, Tsukasa Ohmori, Ichiro Manabe, Joseph E Italiano Jr, Tomiko Ryu, Naoya Takayama, Issei Komuro, Takashi Kadowaki, Koji Eto, Ryozo Nagai
    The Journal of cell biology 209 3 453 - 66 2015年05月 [査読有り][通常論文]
     
    Intravital visualization of thrombopoiesis revealed that formation of proplatelets, which are cytoplasmic protrusions in bone marrow megakaryocytes (MKs), is dominant in the steady state. However, it was unclear whether this is the only path to platelet biogenesis. We have identified an alternative MK rupture, which entails rapid cytoplasmic fragmentation and release of much larger numbers of platelets, primarily into blood vessels, which is morphologically and temporally different than typical FasL-induced apoptosis. Serum levels of the inflammatory cytokine IL-1α were acutely elevated after platelet loss or administration of an inflammatory stimulus to mice, whereas the MK-regulator thrombopoietin (TPO) was not elevated. Moreover, IL-1α administration rapidly induced MK rupture-dependent thrombopoiesis and increased platelet counts. IL-1α-IL-1R1 signaling activated caspase-3, which reduced plasma membrane stability and appeared to inhibit regulated tubulin expression and proplatelet formation, and ultimately led to MK rupture. Collectively, it appears the balance between TPO and IL-1α determines the MK cellular programming for thrombopoiesis in response to acute and chronic platelet needs.
  • Bo-Kyung Son, Daigo Sawaki, Shota Tomida, Daishi Fujita, Kenichi Aizawa, Hiroki Aoki, Masahiro Akishita, Ichiro Manabe, Issei Komuro, Scott L Friedman, Ryozo Nagai, Toru Suzuki
    Nature communications 6 6994 - 6994 2015年04月 [査読有り][通常論文]
     
    Aortic dissection and intramural haematoma comprise an aortopathy involving separation of the aortic wall. Underlying mechanisms of the condition remain unclear. Here we show that granulocyte macrophage colony-stimulating factor (GM-CSF) is a triggering molecule for this condition. Transcription factor Krüppel-like factor 6 (KLF6)-myeloid-specific conditional deficient mice exhibit this aortic phenotype when subjected to aortic inflammation. Mechanistically, KLF6 downregulates expression and secretion of GM-CSF. Administration of neutralizing antibody against GM-CSF prevents the condition in these mice. Conversely, administration of GM-CSF in combination with aortic inflammation to wild-type mice is sufficient to induce the phenotype, suggesting the general nature of effects. Moreover, patients with this condition show highly increased circulating levels of GM-CSF, which is also locally expressed in the dissected aorta. GM-CSF is therefore a key regulatory molecule causative of this aortopathy, and modulation of this cytokine might be an exploitable treatment strategy for the condition.
  • Hiroshi Satonaka, Daisuke Nagata, Masao Takahashi, Arihiro Kiyosue, Masahiro Myojo, Daishi Fujita, Toshihiko Ishimitsu, Tetsuo Nagano, Ryozo Nagai, Yasunobu Hirata
    American journal of physiology. Heart and circulatory physiology 308 8 H853-61 - 61 2015年04月 [査読有り][通常論文]
     
    Antiplatelet drugs, frequently used for cardiovascular events with thrombotic involvement, are also regarded as possible promising agents for cardiovascular primary prevention. The roles of P2Y12, an ADP receptor and the target of thienopyridine antiplatelet drugs, are not satisfactorily known in the vascular wall. We investigated the hypothesis that vascular smooth muscle cell (VSMC) P2Y12 is involved in vascular wall inflammatory changes by upregulating monocyte chemoattractant protein-1 (MCP-1) and promoting monocyte adhesion. ADP at 10(-5) M induced a 3.6 ± 0.3-fold upregulation of MCP-1 mRNA in cultured rat VSMCs, which was significantly inhibited by R-138727, the active metabolite of P2Y12 inhibitor prasugrel and siRNAs against P2Y12. ADP also induced MCP-1 protein upregulation, which was diminished by R-138727 and P2Y12 siRNAs. JNK (c-Jun NH2-terminal kinase) inhibition attenuated ADP-induced MCP-1 mRNA and protein upregulation. R-138727 and P2Y12 siRNAs inhibited ADP-induced JNK activation. The reactive oxygen species (ROS) inhibitors N-acetylcysteine (NAC), diphenyleneiodonium (DPI), and Tempol also diminished MCP-1 upregulation and JNK activation induced by ADP. ADP induced MCP-1 promoter activation, which was inhibited by R-138727 and P2Y12 siRNAs. Nuclear factor-κB (NF-κB) consensus sites in the MCP-1 promoter region were involved in this activation. ADP-induced NF-κB pathway activation, examined by a plasmid containing multiple NF-κB sites, was diminished by P2Y12 inhibition. For cellular function analysis, stimulation of VSMC with ADP increased subsequent THP-1 monocyte adhesion. P2Y12 siRNAs and CCR2 antagonism diminished this ADP-induced monocyte adhesion. These data suggested that ADP, via the VSMC P2Y12 receptor, induces vascular inflammatory changes by upregulating MCP-1 and promoting monocyte adhesion.
  • Munenori Takata, Eisuke Amiya, Masafumi Watanabe, Atsuko Ozeki, Aya Watanabe, Shuichi Kawarasaki, Tomoko Nakao, Yumiko Hosoya, Kansei Uno, Aya Saito, Takahide Murasawa, Minoru Ono, Ryozo Nagai, Issei Komuro
    Heart and vessels 30 2 218 - 26 2015年03月 [査読有り][通常論文]
     
    Aortic stenosis (AS) is the most common valvular disease and aortic valve replacement (AVR) is one of its most effective interventions. AS affects not only the left ventricle, but also vascular function beyond the stenotic valve, which can lead to various types of vascular dysfunction. However, research evaluating the effect of AS on aortic vascular function is limited. In this study, we investigated clinical meaning to evaluate endothelial function in subjects with AS. From April 2011 to April 2012, 20 consecutive adult patients with degenerative AS (mean age, 74.7 ± 7.4 years; range 50-83 years) who underwent AVR at our institution were included in the study. We measured flow-mediated dilation (FMD) to evaluate the effect of AS on endothelial function. The difference between brachial artery diameter (BAD) before (4.0 ± 0.7 mm) and after AVR (3.9 ± 0.6 mm) was not significant (p = 0.043), but FMD significantly improved after AVR (from 3.1 ± 1.8 to 6.0 ± 2.7 %, p < 0.0001). We also analyzed FMD × BAD index, endogenous vasodilatory capability independent of BAD, resulting that it also significantly increased after AVR (12.3 ± 7.0-22.5 ± 9.3, p < 0.0001). We divided patients into two groups by pre- to post-AVR change in FMD (ΔFMD); large-ΔFMD group [ΔFMD >3.0 % (median value)] and small-ΔFMD group (ΔFMD <3.0 %). There were no significant changes in age, blood pressure, heart rate, B-type natriuretic peptide, or echocardiographic parameters in either group. In contrast, BAD was significantly larger in the small ΔFMD group (4.3 ± 0.7 mm) than in the large ΔFMD group (3.7 ± 0.7 mm) (p = 0.030). In addition, cardio-thoracic ratio was significantly greater in the small ΔFMD group (58.4 ± 7.1 %) than in the large ΔFMD group (53.7 ± 4.6 %) (p = 0.048). Receiver operating characteristic curve analysis of BAD to differentiate large and small ΔFMD demonstrated an area under the curve of 0.750 (p = 0.059) and that optimal cutoff for BAD was 4.28 mm (70 % sensitivity, 80 % specificity). AVR in subjects with AS is associated with a significant improvement in FMD in the brachial artery. Measurement of the BAD may be helpful in distinguishing whether the impairment of FMD in AS derives from a stenotic valve or vascular remodeling.
  • Megumi Hirokawa, Hiroyuki Morita, Tomoyuki Tajima, Atsushi Takahashi, Kyota Ashikawa, Fuyuki Miya, Daichi Shigemizu, Kouichi Ozaki, Yasuhiko Sakata, Daisaku Nakatani, Shinichiro Suna, Yasushi Imai, Toshihiro Tanaka, Tatsuhiko Tsunoda, Koichi Matsuda, Takashi Kadowaki, Yusuke Nakamura, Ryozo Nagai, Issei Komuro, Michiaki Kubo
    European journal of human genetics : EJHG 23 3 374 - 80 2015年03月 [査読有り][通常論文]
     
    Despite considerable progress in preventive and therapeutic strategies, myocardial infarction (MI) is one of the leading causes of death throughout the world. A total of 55 susceptibility genes have been identified mostly in European genome-wide association studies (GWAS). Nevertheless, large-scale GWAS from other population could possibly find additional susceptibility loci. To identify as many MI susceptibility loci as possible, we performed a large-scale genomic analysis in Japanese population. To identify MI susceptibility loci in Japanese, we conducted a GWAS using 1666 cases and 3198 controls using the Illumina Human610-Quad BeadChip and HumanHap550v3 Genotyping BeadChip. We performed replication studies using a total of 11,412 cases and 28,397 controls in the Japanese population. Our study identified two novel susceptibility loci for MI: PLCL2 on chromosome 3p24.3 (rs4618210:A>G, P = 2.60 × 10(-9), odds ratio (OR) = 0.91) and AP3D1-DOT1L-SF3A2 on chromosome 19p13.3 (rs3803915:A>C, P = 3.84 × 10(-9), OR = 0.89). Besides, a total of 14 previously reported MI susceptibility loci were replicated in our study. In particular, we validated a strong association on chromosome 12q24 (rs3782886:A>G: P = 1.14 × 10(-14), OR = 1.46). Following pathway analysis using 265 genes related to MI or coronary artery disease, we found that these loci might be involved in the pathogenesis of MI via the promotion of atherosclerosis. In the present large-scale genomic analysis, we identified PLCL2 and AP3D1-DOT1L-SF3A2 as new susceptibility loci for MI in the Japanese population. Our findings will add novel findings for MI susceptibility loci.
  • Takeo Fujino, Atsushi Yao, Masaru Hatano, Toshiro Inaba, Hironori Muraoka, Shun Minatsuki, Teruhiko Imamura, Hisataka Maki, Koichiro Kinugawa, Minoru Ono, Ryozo Nagai, Issei Komuro
    International heart journal 56 1 86 - 93 2015年 [査読有り][通常論文]
     
    BACKGROUND: Therapeutic strategies for pulmonary arterial hypertension (PAH) associated with atrial septal defect (ASD) remain a matter of debate. METHODS AND RESULTS: We identified 5 outpatients who had been diagnosed with ASD-PAH and undergone ASD closure in combination with targeted therapy with certified PAH drugs. We assessed changes in hemodynamic parameters and exercise capacity. The combination of ASD closure and targeted therapy significantly increased systemic blood flow (Qs) from the baseline (from 3.3 ± 0.6 L/minute to 4.2 ± 1.0 L/minute, P < 0.05) with a significant improvement in the World Health Organization Functional Class (WHO-FC; from 2.8 ± 0.4 to 1.6 ± 0.5, P < 0.05). The hemodynamic data before and after ASD closure without targeted therapy showed further elevation of pulmonary vascular resistance shortly after ASD closure (678 dyne · s/cm(5) to 926 dyne · s/cm(5)) in 1 case, as well as after a long time since ASD closure (491.0 ± 53.7 dyne · s/cm(5) to 1045.0 ± 217.8 dyne · s/cm(5)) in 2 cases. This worsening was reversed after the targeted therapy, accompanied by an increase in Qs and an improvement in WHO-FC in all cases. CONCLUSIONS: Targeted therapy should be added to ASD closure in adult patients with ASD-PAH.
  • Atsuko Nakayama, Hiroyuki Morita, Tomoko Nakao, Toshihiro Yamaguchi, Tomokazu Sumida, Yuichi Ikeda, Hidetoshi Kumagai, Yoshihiro Motozawa, Tsukasa Takahashi, Atsushi Imaizumi, Tadashi Hashimoto, Ryozo Nagai, Issei Komuro
    PloS one 10 9 e0137106  2015年 [査読有り][通常論文]
     
    Oxidative stress has been implicated in cardiac remodeling (cardiac fibrosis and hypertrophy), which impairs cardiac function and metabolism; therefore, it is anticipated antioxidative compounds will have protective properties against cardiac remodeling. Luteolin (3',4',5,7-tetrahydroxyflavone), a widely distributed flavonoid found in many herbal extracts including celery, green pepper, perilla leaves and seeds, and chamomile, is a known to be a potent antioxidant and was previously demonstrated to exert an antifibrotic effect in the lungs and the liver. In this study, we clearly demonstrate that oral pretreatment with the higher-luteolin diet (0.035% (wt/wt)) protected against cardiac fibrosis and hypertrophy as well as a hyperoxidative state in Ang II-infused rats. In cardiac tissue, increased gene expression levels of TGFβ1, CTGF, Nox2, Nox4, ANP, and BNP induced by Ang II were restored by oral pretreatment of this high-luteolin diet. In cultured rat cardiac fibroblasts, H2O2-induced TGFβ1 expression and the phosphorylation of JNK were suppressed by luteolin pretreatment. In conclusion, food-derived luteolin has protective actions against Ang II-induced cardiac remodeling, which could be mediated through attenuation of oxidative stress.
  • F Ogata, K Fujiu, I Koshima, R Nagai, I Manabe
    The British journal of dermatology 172 5 1286 - 93 2015年 [査読有り][通常論文]
     
    BACKGROUND: Lymphoedema is a debilitating progressive condition that is frequently observed following cancer surgery and severely restricts quality of life. Although it is known that lymphatic dysfunction and obstruction underlie lymphoedema, the pathogenic mechanism is poorly understood. Smooth muscle cells (SMCs) play pivotal roles in the pathogenesis of various vascular diseases, including atherosclerosis. OBJECTIVES: We analysed SMCs in lymphatic vessels from the lymphoedematous legs of 29 patients. METHODS: Expression of smooth muscle α-actin (SMαA) and smooth muscle myosin heavy chain (SM-MHC) isoforms SM1 and SM2 was investigated using immunohistochemistry. RESULTS: Compared with normal lymphatic vessels, all affected lymphatic vessels in chronic lymphoedema showed marked wall thickening. In addition to increases in the numbers of rows of SMαA(+) SM1(+) SMCs in the tunica media, SMCs were also observed in the subendothelial region (tunica intima). While most intimal and medial cells were positive for SMαA and SM1, staining for SM1 and particularly SM2, a marker of mature SMCs, progressively declined in lymphatic vessels in increasingly severe lymphoedema lesions. Consequently, the SM1(+) and SM2(+) cell fractions were significantly reduced in the tunica media and intima of lymphatic vessels. CONCLUSIONS: These observations indicate that the lymphatic tunica media and tunica intima consist mainly of phenotypically modulated SMCs, and that SMCs play a key role in the development of lymphoedema.
  • Shun Minatsuki, Ichiro Miura, Atsushi Yao, Hiroyuki Abe, Hironori Muraoka, Mariko Tanaka, Teruhiko Imamura, Toshiro Inaba, Hisataka Maki, Masaru Hatano, Koichiro Kinugawa, Takashi Yao, Masashi Fukayama, Ryozo Nagai, Issei Komuro
    International heart journal 56 2 245 - 8 2015年 [査読有り][通常論文]
     
    Pulmonary hypertension (PH) induced by pulmonary tumor thrombotic microangiopathy (PTTM) can be fatal because its rapid progression confounds diagnosis, and it is difficult to control with therapy. Here we describe a woman with symptomatic PTTM-PH accompanying gastric cancer that was suspected from perfusion scintigraphy. PTTM-PH was diagnosed by gastroesophageal endoscopy and lung biopsy after partial control of PH using the platelet-derived growth factor (PDGF) receptor (PDGFR) tyrosine kinase inhibitor, imatinib. Treatment with sildenafil and ambrisentan further decreased PH, and she underwent total gastrectomy followed by adjuvant TS-1 chemotherapy. PH did not recur before her death from metastasis. Postmortem histopathology showed recanalized pulmonary arteries where the embolized cancer masses disappeared. PDGF-A, -B, and PDGFR-α, β expression was detected in cancer cells and proliferating pulmonary vascular endothelial cells. Thus, PTTM-PH was successfully controlled using a combination of imatinib, drugs to treat pulmonary arterial hypertension, and cancer management.
  • Aiko Sakamoto, Yasutomi Higashikuni, Makiko Hongo, Yasushi Imai, Kazuhiko Koike, Ryozo Nagai, Issei Komuro, Nobukazu Ishizaka
    Journal of atherosclerosis and thrombosis 22 12 1225 - 34 2015年 [査読有り][通常論文]
     
    AIM: In an insulin-resistant state, excess lipids may accumulate in various non-adipose tissues, leading to histological and functional damage. It has been suggested that peroxisome proliferator-activated receptor-gamma (PPARγ) may ameliorate disorganized lipid balance. In the current study, we analyzed whether pioglitazone, an agonist of PPARγ, reduces angiotensin II-induced vascular lipid accumulation. METHODS: Angiotensin II was infused into rats at doses of 0.7 mg/kg/day via a subcutaneously implanted osmotic minipump for 7 consecutive days. Pioglitazone was orally given at a dose of 2.5 mg/kg/day for 7 days. RESULTS: Pioglitazone significantly reduced angiotensin II-induced enhanced lipid deposition and superoxide production in the adventitia of the aorta, as detected by oil red O and dihydroethidium (DHE) staining, respectively. Increased DHE signals, some observed at the site of lipid deposition, were mainly localized in ED-1-positive monocytes/macrophages. Angiotensin II-induced upregulation of the expression of LDL receptor and Nox1 was inhibited by pioglitazone treatment. In addition, angiotensin II significantly reduced the expression of PCSK9, and this reduction was ameliorated by pioglitazone. On the other hand, pioglitazone did not significantly alter the expression of the phosphorylated forms of AMPKα and ACC, which was downregulated by angiotensin II. CONCLUSIONS: Pioglitazone treatment suppressed excess lipid accumulation and superoxide production in the aorta in an angiotensin II-induced rat model of hypertension.
  • Ryozo Nagai
    Rinsho byori. The Japanese journal of clinical pathology 62 10 976 - 85 2014年10月 [査読有り][通常論文]
     
    Medical research including cardiovascular research aims to understand the mechanisms underlying physiology and pathophysiology. Many diseases, however, develop as a result of very complicated interactions among cells/molecules, and, therefore, no factor can be singled out as the dominant mechanism. This is even more clearly the case with chronic diseases, whose underlying mechanisms may be chronic inflammation, and insights into system links such as intercellular or inter-organ ones are, therefore, indispensable to understand the diseases. Here, I introduce heterocellular and organ-organ interplays which have critical roles in the development of cardiovascular and metabolic diseases. It is also noteworthy that a large amount of medical information is processed in daily medical practice. Additionally, numerous clinical trials, physician-led clinical research, and epidemiological studies are conducted using the Internet. Moreover, in basic research, analytical technologies to assess the functions of the genome, molecules, and cells have advanced progressively, and a large amount of information is generated in a short period of time. Large-volume information and networking are important issues among medical organizations in community medicine. In the medical practice of cardiology, covering both acute treatment and chronic disorders, it is also necessary to reconsider the flow of medical information. In particular, for future clinical practice and studies in cardiology, we need to acknowledge the risk that accompanies building up knowledge based on this large-volume information and take measures against this risk.
  • Kazuyoshi Ohtomo, Takashi Shigeeda, Akira Hirose, Takayuki Ohno, Osamu Kinoshita, Hideo Fujita, Jiro Ando, Ryozo Nagai, Shinichi Takamoto, Takashi Kadowaki, Satoshi Kato
    Acta ophthalmologica 92 6 e492-3  2014年09月 [査読有り][通常論文]
  • Atsuko Ozeki, Eisuke Amiya, Masafumi Watanabe, Yumiko Hosoya, Munenori Takata, Aya Watanabe, Shuichi Kawarasaki, Tomoko Nakao, Shogo Watanabe, Kazuko Omori, Namie Yamada, Yukiko Tahara, Yasunobu Hirata, Ryozo Nagai
    Journal of clinical hypertension (Greenwich, Conn.) 16 8 591 - 8 2014年08月 [査読有り][通常論文]
     
    The aim of this study was to evaluate the add-on effect of aliskiren to valsartan on endothelial-dependent vasodilation in hypertensive patients with ischemic heart disease (IHD). After 4 weeks of treatment with 80 mg of valsartan, 28 patients were allocated to either continued treatment with valsartan or an add-on treatment with valsartan plus 150 mg of aliskiren. Aliskiren significantly decreased plasma renin activity, whereas endothelium-dependent vasodilation measured by flow-mediated dilation (FMD) did not change. In contrast, heart rate significantly decreased (73.1 ± 9.8 to 66.3 ± 7.0 beats per minute at baseline and 24 weeks, respectively [P = .009]) and the standard deviation of the R-R intervals (SDNN) significantly increased in the aliskiren group. The add-on aliskiren to valsartan therapy may not improve endothelial functions, although it significantly reduced resting heart rate via regulation of the autonomic nervous system in hypertensive patients with IHD.
  • Munenori Takata, Eisuke Amiya, Masafumi Watanabe, Kazuko Omori, Yasushi Imai, Daishi Fujita, Hiroshi Nishimura, Masayoshi Kato, Tetsuro Morota, Kan Nawata, Atsuko Ozeki, Aya Watanabe, Shuichi Kawarasaki, Yumiko Hosoya, Tomoko Nakao, Koji Maemura, Ryozo Nagai, Yasunobu Hirata, Issei Komuro
    Heart and vessels 29 4 478 - 85 2014年07月 [査読有り][通常論文]
     
    Marfan syndrome is an inherited disorder characterized by genetic abnormality of microfibrillar connective tissue proteins. Endothelial dysfunction is thought to cause aortic dilation in subjects with a bicuspid aortic valve; however, the role of endothelial dysfunction and endothelial damaging factors has not been elucidated in Marfan syndrome. Flow-mediated dilation, a noninvasive measurement of endothelial function, was evaluated in 39 patients with Marfan syndrome. Aortic diameter was measured at the aortic annulus, aortic root at the sinus of Valsalva, sinotubular junction and ascending aorta by echocardiography, and adjusted for body surface area (BSA). The mean value of flow-mediated dilation was 6.5 ± 2.4 %. Flow-mediated dilation had a negative correlation with the diameter of the ascending thoracic aorta (AscAd)/BSA (R = -0.39, p = 0.020) and multivariate analysis revealed that flow-mediated dilation was an independent factor predicting AscAd/BSA, whereas other segments of the aorta had no association. Furthermore, Brinkman index had a somewhat greater influence on flow-mediated dilation (R = -0.42, p = 0.008). Although subjects who smoked tended to have a larger AscAd compared with non-smokers (AscA/BSA: 17.3 ± 1.8 versus 15.2 ± 3.0 mm/m(2), p = 0.013), there was no significant change in flow-mediated dilation, suggesting that smoking might affect aortic dilation via an independent pathway. Common atherogenic risks, such as impairment of flow-mediated dilation and smoking status, affected aortic dilation in subjects with Marfan syndrome.
  • Takeo Nakaya, Seishi Ogawa, Ichiro Manabe, Masami Tanaka, Masashi Sanada, Toshiro Sato, Makoto M Taketo, Kazuki Nakao, Hans Clevers, Masashi Fukayama, Masahiko Kuroda, Ryozo Nagai
    Cancer research 74 10 2882 - 91 2014年05月 [査読有り][通常論文]
     
    The intestinal epithelium maintains homeostasis by a self-renewal process involving resident stem cells, including Lgr5(+) crypt-base columnar cells, but core mechanisms and their contributions to intestinal cancer are not fully defined. In this study, we examined a hypothesized role for KLF5, a zinc-finger transcription factor that is critical to maintain the integrity of embryonic and induced pluripotent stem cells, in intestinal stem-cell integrity and cancer in the mouse. Klf5 was indispensable for the integrity and oncogenic transformation of intestinal stem cells. In mice, inducible deletion of Klf5 in Lgr5(+) stem cells suppressed their proliferation and survival in a manner associated with nuclear localization of β-catenin (Catnb), generating abnormal apoptotic cells in intestinal crypts. Moreover, production of lethal adenomas and carcinomas by specific expression of an oncogenic mutant of β-catenin in Lgr5(+) stem cells was suppressed completely by Klf5 deletion in the same cells. Given that activation of the Wnt/β-catenin pathway is the most frequently altered pathway in human colorectal cancer, our results argue that KLF5 acts as a fundamental core regulator of intestinal oncogenesis at the stem-cell level, and they suggest KLF5 targeting as a rational strategy to eradicate stem-like cells in colorectal cancer.
  • Naoko Kato, Koichiro Kinugawa, Imamura Teruhiko, Muraoka Hironori, Maki Hisataka, Inaba Toshiro, Hatano Masaru, Yao Atsushi, Ryozo Nagai
    International journal of cardiology 173 2 331 - 3 2014年05月 [査読有り][通常論文]
  • Ryozo Nagai
    [Hokkaido igaku zasshi] The Hokkaido journal of medical science 89 1 5 - 7 2014年05月 [査読有り][通常論文]
  • Eisuke Amiya, Masafumi Watanabe, Munenori Takata, Tomoko Nakao, Yumiko Hosoya, Shogo Watanabe, Ryozo Nagai, Issei Komuro
    Clinical autonomic research : official journal of the Clinical Autonomic Research Society 24 2 95 - 7 2014年04月 [査読有り][通常論文]
     
    We conducted a retrospective study of 60 patients with ischemic heart disease (31 with diabetes and 29 without diabetes) to investigate the impact of diabetes on diurnal body temperature patterns. We found that the increase of axillary body temperature in the evening was reduced in the presence of diabetes, which was associated with autonomic neuropathy.
  • Koichiro Kinugawa, Ryozo Nagai, Hiroshi Inoue, Hirotsugu Atarashi, Yoshihiko Seino, Takeshi Yamashita, Wataru Shimizu, Takeshi Aiba, Masafumi Kitakaze, Atsuhiro Sakamoto, Takanori Ikeda, Yasushi Imai, Takashi Daimon, Katsuhiro Fujino, Tetsuji Nagano, Tatsuaki Okamura, Masatsugu Hori
    Advances in therapy 31 4 426 - 39 2014年04月 [査読有り][通常論文]
     
    INTRODUCTION: Results from the multicenter trial (J-Land study) of landiolol versus digoxin in atrial fibrillation (AF) and atrial flutter (AFL) patients with left ventricular (LV) dysfunction revealed that landiolol was more effective for controlling rapid HR than digoxin. The subgroup analysis for patient characteristics was conducted to evaluate the impact on the efficacy and safety of landiolol compared with digoxin. METHODS: Two hundred patients with AF/AFL, heart rate (HR) ≥ 120 beats/min, and LV ejection fraction (LVEF) 25-50% were randomized to receive either landiolol (n = 93) or digoxin (n = 107). Successful HR control was defined as ≥20% reduction in HR together with HR < 110 beats/min at 2 h after starting intravenous administration of landiolol or digoxin. The subgroup analysis for patient characteristics was to evaluate the impact on the effectiveness of landiolol in AF/AFL patients complicated with LV dysfunction. RESULTS: The efficacy in patients with NYHA class III/NYHA class IV was 52.3%/35.3% in landiolol, and 13.8%/9.1% in digoxin (p < 0.001 and p = 0.172), lower LVEF (25-35%)/higher LVEF (35-50%) was 45.7%/51.1% in landiolol, and 14.0%/12.7% in digoxin (p < 0.001 and p < 0.001), CKD stage 1 (90 < eGFR)/CKD stage 2 (60 ≤ eGFR < 90)/CKD stage 3 (30 ≤ eGFR < 60)/CKD stage 4 (15 ≤ eGFR < 30) was 66.7%/59.1%/39.6%/66.7% in landiolol, and 0%/13.8%/17.0%/0% in digoxin (p = 0.003, p < 0.001, p = 0.015 and p = 0.040). CONCLUSIONS: This subgroup analysis indicated that landiolol was more useful, regardless of patient characteristics, as compared with digoxin in AF/AFL patients complicated with LV dysfunction. Particularly, in patients with impaired renal function, landiolol should be preferred for the purpose of acute rate control of AF/AFL tachycardia.
  • 冠動脈疾患患者における脳卒中危険因子としての抗血栓療法と収縮期血圧レベル(Anti-thrombotic Therapy and Systolic Blood Pressure Levels as Risk Factors of Strokes in Patients with Coronary Artery Disease)
    Kai Hisashi, Kohro Takahide, Fukuda Kenji, Fukumoto Yoshihiro, Yamazaki Tsutomu, Nagai Ryozo
    Circulation Journal 78 Suppl.I 500 - 500 2014年03月
  • ARID5B発現がプロモーターのPPREを介しアディポネクチン発現量を調節することにより、アテローム性動脈硬化症および糖尿病への易罹患性に影響を及ぼす可能性(ARID5B Expression may Affect Susceptibility to Atherosclerosis and Diabetes Mellitus by Regulating Adiponectin Expression Level through PPRE in the Promoter)
    Ozeki Atsuko, Watanabe Masafumi, Manabe Ichiro, Imai Yasushi, Watanabe Aya, Kawarasaki Shuichi, Maemura Koji, Yamazaki Tsutomu, Nagai Ryozo, Komuro Issei
    Circulation Journal 78 Suppl.I 35 - 35 2014年03月
  • Li-Jun Yuan, Katsu Takenaka, Kansei Uno, Aya Ebihara, Kazuno Sasaki, Takako Komuro, Makoto Sonoda, Ryozo Nagai
    Cardiovascular ultrasound 12 7 - 7 2014年02月 [査読有り][通常論文]
     
    BACKGROUND: Animal studies have shown that shear deformation of myocardial sheets in transmural planes of left ventricular (LV) wall is an important mechanism for systolic wall thickening, and normal and shear strains of the LV free wall differ from those of the interventricular septum (IVS). We sought to test whether these also hold for human hearts. METHODS: Thirty healthy volunteers (male 23 and female 7, aged 34 ± 6 years) from Outpatient Department of the University of Tokyo Hospital were included. Echocardiographic images were obtained in the left decubitus position using a commercially available system (Aloka SSD-6500, Japan) equipped with a 3.5-MHz transducer. The ECG was recorded simultaneously. The peak systolic radial normal strain (length change), shear strain (angle change) and time to peak systolic radial normal strain were obtained non-invasively by two-dimensional speckle tracking echocardiography. RESULTS: The peak systolic radial normal strain in both IVS and LV posterior wall (LVPW) showed a trend to increase progressively from the apical level to the basal level, especially at short axis views, and the peak systolic radial normal strain of LVPW was significantly greater than that of IVS at all three levels. The time to peak systolic radial normal strain was the shortest at the basal IVS, and increased progressively from the base to the apical IVS. It gradually increased from the apical to the basal LVPW in sequence, especially at short axis views. The peak of radial normal strain of LVPW occurred much later than the peak of IVS at all three levels. For IVS, the shear deformation was clockwise at basal level, and counterclockwise at mid and apical levels in LV long-axis view. For LVPW, the shear deformations were all counterclockwise in LV long-axis view and increased slightly from base to the apex. LVPW showed larger shear strains than IVS at all three levels. Bland-Altman analysis shows very good agreement between measurements taken by the same observer and by two independent observers. CONCLUSION: "Myocardial sheets" theory also holds true for intact human LV. Moreover, dyssynchrony exists even in healthy human subjects, which should be considered when evaluating the diseased hearts.
  • Kenichiro Yamagata, Yuki Goto, Hiroshi Nishimasu, Jumpei Morimoto, Ryuichiro Ishitani, Naoshi Dohmae, Norihiko Takeda, Ryozo Nagai, Issei Komuro, Hiroaki Suga, Osamu Nureki
    Structure (London, England : 1993) 22 2 345 - 52 2014年02月 [査読有り][通常論文]
     
    SIRT2 deacetylates specific acetyllysine residues in diverse proteins and is implicated in a variety of cellular processes. SIRT2 inhibition thus has potentials to treat human diseases such as cancers and neurodegenerative disorders. We have recently developed a series of ε-trifluoroacetyllysine-containing macrocyclic peptides, which inhibit the SIRT2 activity more potently than most other known inhibitors. Here, we report the crystal structure of human SIRT2 in complex with a macrocyclic peptide inhibitor, S2iL5, at 2.5 Å resolution. The structure revealed that S2iL5 binds to the active site of SIRT2 through extensive interactions. A structural comparison of the SIRT2-S2iL5 complex with SIRT2 in the free form, and in complex with ADP-ribose, revealed that S2iL5 induces an open-to-closed domain movement and an unexpected helix-to-coil transition in a SIRT2-specific region. Our findings unveil the potential of macrocyclic peptides to bind target proteins by inducing dynamic structural changes.
  • Yuji Nishizaki, Kazunori Shimada, Shigemasa Tani, Takayuki Ogawa, Jiro Ando, Masao Takahashi, Masato Yamamoto, Tomohiro Shinozaki, Katsumi Miyauchi, Ken Nagao, Atsushi Hirayama, Michihiro Yoshimura, Issei Komuro, Ryozo Nagai, Hiroyuki Daida
    The American journal of cardiology 113 3 441 - 5 2014年02月 [査読有り][通常論文]
     
    This study aimed to assess the balance of serum n-3 to n-6 polyunsaturated fatty acids (PUFAs) in patients with acute coronary syndrome (ACS). We enrolled 1,119 patients who were treated and in whom serum PUFA level was evaluated in 5 divisions of cardiology in a metropolitan area in Japan. Serum levels of PUFAs, including eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and arachidonic acid (AA), were compared between patients with and without ACS. We also evaluated the balance of serum n-3 to n-6 PUFAs, including EPA/AA and DHA/AA ratios. EPA/AA values were 0.46 ± 0.32 and 0.50 ± 0.32 in the ACS and non-ACS groups, respectively. DHA/AA values were 0.95 ± 0.37 and 0.96 ± 0.41 in the ACS and non-ACS groups, respectively. Next, we divided the patients into 3 groups based on the tertiles of EPA/AA or tertiles of DHA/AA to determine the independent risk factors for ACS. According to multivariate logistic regression analysis, the group with the lowest EPA/AA (≤0.33) had a greater probability of ACS (odds ratio 3.14, 95% confidence interval 1.16 to 8.49), but this was not true for DHA/AA. In conclusion, an imbalance in the ratio of serum EPA to AA, but not in the ratio of DHA to AA, was significantly associated with ACS.
  • Toshiya Kojima, Yasushi Imai, Kensuke Tsushima, Kansei Uno, Katsuhito Fujiu, Taroh Iiri, Hiroaki Nishimatsu, Takeki Suzuki, Hiroaki Sugiyama, Kazuo Asada, Tomoko Nakao, Hiroshi Yamashita, Yasunobu Hirata, Ryozo Nagai
    Journal of cardiothoracic and vascular anesthesia 28 1 124 - 127 2014年02月 [査読有り][通常論文]
  • Makoto Sahara, Masayasu Ikutomi, Toshihiro Morita, Yoshiyasu Minami, Toshiaki Nakajima, Yasunobu Hirata, Ryozo Nagai, Masataka Sata
    Cardiovascular research 101 2 236 - 46 2014年02月 [査読有り][通常論文]
     
    AIMS: Angiotensin-converting enzyme 2 (ACE2) is known as a negative regulator of the renin-angiotensin system. We aimed to determine the roles of ACE2 on the development of vascular diseases. METHODS AND RESULTS: Using two diversely different models of vascular diseases, hyperlipidaemia-induced atherosclerosis in apolipoprotein E knockout (KO) mice and mechanical injury-induced arterial neointimal hyperplasia in C57Bl6 mice, we examined whether ACE2 deficiency could affect formation of the vascular lesions. ACE2 deficiency resulted in significantly larger vascular lesions in both aortic atherosclerotic plaques and arterial neointima formation, compared with ACE2(+) control. These ACE2-deficient vascular lesions exhibited enhanced accumulation of macrophages into the lesions and proliferation of vascular smooth muscle cells (VSMCs), accompanied with increased angiotensin-II (Ang-II) levels and enhanced expression of vascular inflammation-related genes, including vascular cell adhesion molecule (VCAM)-1, monocyte chemoattractant protein (MCP)-1, and matrix metalloproteinase (MMP)9 in aorta/artery tissues. Primary bone marrow macrophages and aortic VSMCs isolated from ACE2 KO mice also displayed enhanced pro-inflammatory responsiveness such as up-regulated gene/protein expression of VCAM-1, MCP-1, and MMP9 to stimulation with tumour necrosis factor-α and Ang-II. The similar phenotype was shown in human macrophages and aortic VSMCs that were transfected with ACE2-specific siRNA. In ACE2-deficient VSMCs, inhibition of c-Jun N-terminal kinase (JNK) by pharmacological blockade with SP600125 or genetic knockdown with JNK-specific siRNA significantly attenuated their pro-inflammatory phenotype. CONCLUSION: ACE2 deficiency promotes the development of vascular diseases associated with Ang-II-mediated vascular inflammation and activation of the JNK signalling, leading to the notion that ACE2 potentially confers protection against vascular diseases.
  • Satoshi Nishimura, Mika Nagasaki, Ichiro Manabe, Koji Eto, Takashi Kadowaki, Ryozo Nagai
    Inflammation Research 58 2 S234 - S238 2014年 [査読有り][通常論文]
     
    Obese visceral adipose tissue remodeling and dysfunction, based on chronic inflammation and local immunological changes, play major roles in the metabolic syndrome. Therefore, to assess the dynamic interplay between multiple cell types in obese adipose, an in vivo visualization technique was developed. In vivo imaging revealed close spatial and temporal interrelationships between angiogenesis and adipogenesis, which were augmented in obese adipose tissue. In addition, increased leukocyte-platelet-endothelial cell interactions were observed in the microcirculation, a hallmark of inflammation. Upregulated expression of adhesion molecules contribute to local activation of inflammatory processes. We also found that large numbers of CD8+ effector T cells infiltrated into the obese adipose tissue, playing major roles in inflammatory macrophage infiltration into obese adipose tissue, induction and maintenance of inflammation, and systemic insulin resistance. Our results demonstrate the power of our imaging technique to analyze multi-cellular interactions in inflammation in vivo and to evaluate new therapeutic interventions.
  • Naoko Kato, Koichiro Kinugawa, Teruhiko Imamura, Hironori Muraoka, Hisataka Maki, Toshiro Inaba, Masaru Hatano, Atsushi Yao, Ryozo Nagai
    International Journal of Cardiology 176 1 303  2014年 [査読有り][通常論文]
  • Masatsugu Hori, Ryozo Nagai, Tohru Izumi, Masunori Matsuzaki
    Heart and Vessels 29 2 238 - 247 2014年 [査読有り][通常論文]
     
    Bisoprolol fumarate (bisoprolol) is a β-blocker widely used to treat chronic heart failure (CHF). However, few studies have compared its efficacy and safety with those of the widely used β-blocker carvedilol in Japanese patients with CHF. We designed a confirmatory trial of bisoprolol using carvedilol as a control drug however, the trial was discontinued after an off-label use of bisoprolol was approved during the study. Bisoprolol and carvedilol were administered for 32 weeks in 31 and 28 patients, respectively. The mean maintenance doses of bisoprolol and carvedilol were 3.3 and 13.6 mg/day, respectively, and the mean durations of treatment were 188.2 and 172.9 days, respectively. Heart-rate changes were similar in both groups. The mean changes from baseline to Week 32 in left ventricular (LV) ejection fraction (EF) (bisoprolol vs carvedilol groups 11.7 % ± 8.6 % vs 10.1 % ± 10.5 %), LV end-diastolic volume (-37.5 ± 48.7 vs -24.7 ± 29.4 ml), and LV end-systolic volume (-41.9 ± 43.0 vs -29.3 ± 25.9 ml) revealed a decrease in LV volume and an increase in LVEF in both groups. The cumulative event-free rate for a composite of cardiovascular death or admissions to hospital for worsening of CHF was 92.4 % and 94.7 % in the bisoprolol and carvedilol groups, respectively. Overall, 90.3 % and 85.7 % of patients were titrated up to the maintenance doses of bisoprolol and carvedilol, respectively. Bisoprolol, at half the dose used in other countries, is well tolerated and is as effective as carvedilol for treating Japanese patients with mild to moderate CHF. © 2013 Springer.
  • Miyu Tajima, Ryozo Nagai, Yukio Hiroi
    International heart journal 55 4 287 - 95 2014年 [査読有り][通常論文]
     
    Immunoglobulin4 (IgG4)-related disease is a systemic inflammatory disease characterized by elevation of serum IgG4. It involves various organs such as the pancreas (autoimmune pancreatitis), lacrimal gland (Mikulicz's disease), retroperitoneum (retroperitoneal fibrosis), aorta (aortic aneurysm and aortitis), heart (constrictive pericarditis), and pseudotumors around the coronary arteries. These disorders often coexist in accordance with progression of the disease. Because IgG4-related cardiovascular disorder affects the patient's prognosis, early detection and treatment is important. Coronary CT imaging and echocardiography accidentally detect IgG4-related disorders and (18)FDG-PET imaging can identify active inflammation in the lesions. Measurement of serum IgG4 levels and tissue biopsy are necessary for diagnosis. Minor salivary gland biopsy is recommended even though (18)FDG uptake is not detected when it is difficult to obtain a biopsy specimen from IgG4-related cardiovascular lesions. The first-line treatment is high-dose corticosteroid therapy, however, relapse is often reported. Corticosteroids suppress the development of active inflammatory diseases such as aortitis, pericarditis, and pseudotumors, but already-developed lesions do not respond. A large developed aneurysm can rupture even during or after corticosteroid therapy, therefore, additional surgical treatment may be needed. Treatment of IgG4-related cardiovascular disorders might require higher doses of corticosteroids than IgG4-related extracardiovascular disorders. The adequate dose of corticosteroid, type and dose of immunosuppressant, and surgical intervention should be carefully considered on a case-by-case basis.
  • Miyu Tajima, Yukio Hiroi, Yutaka Takazawa, Hironori Muraoka, Hiroshi Iwata, Hiroshi Yamashita, Yasunobu Hirata, Ryozo Nagai
    Human pathology 45 1 175 - 9 2014年01月 [査読有り][通常論文]
     
    Immunoglobulin G4 (IgG4)-related disorders in various organs have recently been described, but multiple systemic aneurysms have not yet been reported. Here, we present a 68-year-old Japanese man with multiple systemic aneurysms and tumor-forming pericoronary arteritis who was undergoing low-dose corticosteroid therapy. Elevated serum IgG4 (2390 mg/dL) and IgG4-positive plasmacyte infiltration in the salivary glands led to a diagnosis of IgG4-related disease. High-dose corticosteroid therapy was initiated, whereupon the inflammatory lesions shrank. However, the large, well-developed common hepatic aneurysm and splenic aneurysm did not change. Our patient died of splenic aneurysm rupture in the sixth month of treatment. The autopsy revealed IgG4-positive plasmacyte infiltration in the coronary wall and a thinned splenic aneurysm wall. This case suggests that early high-dose corticosteroid therapy may be necessary for the treatment of IgG4-related cardiovascular disorders. A minor salivary gland biopsy might facilitate the early diagnosis of IgG4-related disease even if (18)F-fluorodeoxyglucose positron emission tomography provides no inflammatory findings.
  • Shogo Watanabe, Eisuke Amiya, Masafumi Watanabe, Munenori Takata, Atsuko Ozeki, Aya Watanabe, Shuichi Kawarasaki, Tomoko Nakao, Yumiko Hosoya, Kohzo Nagata, Ryozo Nagai, Issei Komuro
    PloS one 9 10 e110013  2014年 [査読有り][通常論文]
     
    PURPOSE: The physiological role of vasomotion, rhythmic oscillations in vascular tone or diameter, and its underlying mechanisms are unknown. We investigated the characteristics of brachial artery vasomotion in patients with ischemic heart disease (IHD). METHODS: We performed a retrospective study of 37 patients with IHD. Endothelial function was assessed using flow-mediated dilation (FMD), and power spectral analysis of brachial artery diameter oscillations during FMD was performed. Frequency-domain components were calculated by integrating the power spectrums in three frequency bands (in ms2) using the MemCalc (GMS, Tokyo, Japan): very-low frequency (VLF), 0.003-0.04 Hz; low frequency (LF), 0.04-0.15 Hz; and high frequency (HF), 0.15-0.4 Hz. Total spectral power (TP) was calculated as the sum of all frequency bands, and each spectral component was normalized against TP. RESULTS: Data revealed that HF/TP closely correlated with FMD (r = -0.33, p = 0.04), whereas VLF/TP and LF/TP did not. We also explored the relationship between elevated C-reactive protein (CRP) levels and vasomotion. HF/TP was significantly increased in subjects with high CRP levels (CRP;>0.08 mg/dL) compared with subjects with low CRP levels (0.052±0.026 versus 0.035±0.022, p<0.05). The HF/TP value closely correlated with CRP (r = 0.24, p = 0.04), whereas the value of FMD did not (r = 0.023, p = 0.84). In addition, elevated CRP levels significantly increased the value of HF/TP after adjustment for FMD and blood pressure (β = 0.33, p<0.05). CONCLUSION: The HF component of brachial artery diameter oscillation during FMD measurement correlated well with FMD and increased in the presence of elevated CRP levels in subjects with IHD.
  • Atsuko Nakayama, Hiroyuki Morita, Tetsuro Miyata, Katsuyuki Hoshina, Masatoshi Nagayama, Shuichiro Takanashi, Tetsuya Sumiyoshi, Issei Komuro, Ryozo Nagai
    HEART AND VESSELS 29 1 65 - 70 2014年01月 [査読有り][通常論文]
     
    In Japan, there has been virtually no study in a population large enough to definitively demonstrate a relationship between the preoperative clinical features and postoperative outcomes in patients undergoing abdominal aortic aneurysm (AAA) repair. The aim of this study was to determine the preoperative variables that significantly predict postoperative mortality after emergency or elective repair in Japanese patients with infrarenal AAA. In this retrospective cohort study, we assessed significant predictors of postoperative mortality in 1055 consecutive patients undergoing emergency (n = 186) or elective repair (n = 869) of an infrarenal AAA at the University of Tokyo Hospital or Sakakibara Heart Institute (Tokyo, Japan). Using logistic regression analysis, anemia (hemoglobin < 9 g/dl), shock (systolic blood pressure < 80 mmHg), and hypocholesterolemia (total cholesterol < 120 mg/dl) were found to be independent preoperative predictors of 30-day mortality after emergency repair for ruptured AAA. The hazard ratio (HR) (95 % confidence interval) for these three predictors was 5.96 (1.70-20.84), 8.48 (1.47-49.02), and 7.31 (1.96-27.35), respectively. In the elective repair cases, no significant preoperative predictor of postoperative mortality could be identified either within or beyond 30 days of surgery. Hypocholesterolemia, anemia, and shock were found to be independent preoperative predictors of a postoperative high mortality rate in Japanese patients undergoing emergency repair for ruptured infrarenal AAA.
  • Takehiro Takahashi, Yoshihide Asano, Eisuke Amiya, Masaru Hatano, Zenshiro Tamaki, Munenori Takata, Atsuko Ozeki, Aya Watanabe, Shuichi Kawarasaki, Takashi Taniguchi, Yohei Ichimura, Tetsuo Toyama, Masafumi Watanabe, Yasunobu Hirata, Ryozo Nagai, Issei Komuro, Shinichi Sato
    Modern rheumatology 24 1 106 - 11 2014年01月 [査読有り][通常論文]
     
    OBJECTIVE: To investigate the clinical significance of flow-mediated dilation (FMD) in systemic sclerosis (SSc). METHODS: Thirty-three SSc patients and 12 healthy controls were studied. Ultrasound assessment of the brachial artery FMD was performed on all subjects. The results were expressed as the percentage of increase in brachial artery diameter following hyperemia. RESULTS: Limited cutaneous SSc (lcSSc) patients had significantly lower FMD values than healthy controls (5.3 ± 2.7 versus 7.7 ± 2.0 %, p < 0.05), while the values in diffuse cutaneous SSc (dcSSc) patients (6.7 ± 4.0 %) were comparable to those in lcSSc patients and healthy controls. Although FMD values did not correlate with any clinical features in dcSSc patients, there was an inverse correlation between FMD values and disease duration in lcSSc patients (r = -0.64, p < 0.05). Furthermore, lcSSc patients with decreased FMD values showed significantly higher prevalence of digital ulcers and elevated right ventricular systolic pressure than those with normal values (for each; 75 versus 10 %, p < 0.05). CONCLUSION: The FMD values represent the severity of vascular damages, which progress along with disease duration and lead to digital ulcers and pulmonary arterial hypertension, in lcSSc patients.
  • Masahiro Myojo, Daisuke Nagata, Daishi Fujita, Arihiro Kiyosue, Masao Takahashi, Hiroshi Satonaka, Yoshiyuki Morishita, Tetsu Akimoto, Ryozo Nagai, Issei Komuro, Yasunobu Hirata
    PloS one 9 5 e96948  2014年 [査読有り][通常論文]
     
    Because endothelial nitric oxide synthase (eNOS) has anti-inflammatory and anti-arteriosclerotic functions, it has been recognized as one of the key molecules essential for the homeostatic control of blood vessels other than relaxation of vascular tone. Here, we examined whether telmisartan modulates eNOS function through its pleiotropic effect. Administration of telmisartan to mice significantly increased the phosphorylation level of eNOS (Ser1177) in the aortic endothelium, but administration of valsartan had no effect. Similarly, telmisartan treatment of human umbilical vein endothelial cells significantly increased the phosphorylation levels of AMP-activated protein kinase (Thr172) and eNOS and the concentration of intracellular guanosine 3',5'-cyclic monophosphate (cGMP). Furthermore, pretreatment with a p38 mitogen-activated protein kinase (p38 MAPK) inhibitor suppressed the increased phosphorylation level of eNOS and intracellular cGMP concentration. These data show that telmisartan increases eNOS activity through Ser1177 phosphorylation in vascular endothelial cells mainly via p38 MAPK signaling.
  • Higashikuni Yasutomi, Nagai Ryozo, Sata Masataka, Komuro Issei
    CIRCULATION 128 22 2013年11月 [査読有り][通常論文]
  • Higashikuni Yasutomi, Nagai Ryozo, Sata Masataka, Komuro Issei
    CIRCULATION 128 22 2013年11月 [査読有り][通常論文]
  • Yasutomi Higashikuni, Kimie Tanaka, Megumi Kato, Osamu Nureki, Yasunobu Hirata, Ryozo Nagai, Issei Komuro, Masataka Sata
    Journal of the American Heart Association 2 6 e000267  2013年11月 [査読有り][通常論文]
     
    BACKGROUND: Inflammation is induced in the heart during the development of cardiac hypertrophy. The initiating mechanisms and the role of inflammation in cardiac hypertrophy, however, remain unclear. Toll-like receptor-2 (TLR2) recognizes endogenous molecules that induce noninfectious inflammation. Here, we examined the role of TLR2-mediated inflammation in cardiac hypertrophy. METHODS AND RESULTS: At 2 weeks after transverse aortic constriction, Tlr2(-/-) mice showed reduced cardiac hypertrophy and fibrosis with greater left ventricular dilatation and impaired systolic function compared with wild-type mice, which indicated impaired cardiac adaptation in Tlr2(-/-) mice. Bone marrow transplantation experiment revealed that TLR2 expressed in the heart, but not in bone marrow-derived cells, is important for cardiac adaptive response to pressure overload. In vitro experiments demonstrated that TLR2 signaling can induce cardiomyocyte hypertrophy and fibroblast and vascular endothelial cell proliferation through nuclear factor-κB activation and interleukin-1β upregulation. Systemic administration of a nuclear factor-κB inhibitor or anti-interleukin-1β antibodies to wild-type mice resulted in impaired adaptive cardiac hypertrophy after transverse aortic constriction. We also found that heat shock protein 70, which was increased in murine plasma after transverse aortic constriction, can activate TLR2 signaling in vitro and in vivo. Systemic administration of anti-heat shock protein 70 antibodies to wild-type mice impaired adaptive cardiac hypertrophy after transverse aortic constriction. CONCLUSIONS: Our results demonstrate that TLR2-mediated inflammation induced by extracellularly released heat shock protein 70 is essential for adaptive cardiac hypertrophy in response to pressure overload. Thus, modulation of TLR2 signaling in the heart may provide a novel strategy for treating heart failure due to inadequate adaptation to hemodynamic stress.
  • Satoshi Nishimura, Ichiro Manabe, Satoshi Takaki, Mika Nagasaki, Makoto Otsu, Hiroshi Yamashita, Junichi Sugita, Kotaro Yoshimura, Koji Eto, Issei Komuro, Takashi Kadowaki, Ryozo Nagai
    Cell metabolism 18 5 759 - 766 2013年11月 [査読有り][通常論文]
     
    Distinct B cell populations, designated regulatory B (Breg) cells, are known to restrain immune responses associated with autoimmune diseases. Additionally, obesity is known to induce local inflammation within adipose tissue that contributes to systemic metabolic abnormalities, but the underlying mechanisms that modulate adipose inflammation remain poorly understood. We identified Breg cells that produce interleukin-10 constitutively within adipose tissue. B cell-specific Il10 deletion enhanced adipose inflammation and insulin resistance in diet-induced obese mice, whereas adoptive transfer of adipose tissue Breg cells ameliorated those effects. Adipose environmental factors, including CXCL12 and free fatty acids, support Breg cell function, and Breg cell fraction and function were reduced in adipose tissue from obese mice and humans. Our findings indicate that adipose tissue Breg cells are a naturally occurring regulatory B cell subset that maintains homeostasis within adipose tissue and that Breg cell dysfunction contributes pivotally to the progression of adipose tissue inflammation in obesity.
  • Hua Shen, Kosei Eguchi, Nozomu Kono, Katsuhito Fujiu, Sahohime Matsumoto, Munehiko Shibata, Yumiko Oishi-Tanaka, Issei Komuro, Hiroyuki Arai, Ryozo Nagai, Ichiro Manabe
    Arteriosclerosis, thrombosis, and vascular biology 33 11 2596 - 607 2013年11月 [査読有り][通常論文]
     
    OBJECTIVE: Obesity is a major risk factor of atherosclerotic cardiovascular disease. Circulating free fatty acid levels are known to be elevated in obese individuals and, along with dietary saturated fatty acids, are known to associate with cardiovascular events. However, little is known about the molecular mechanisms by which free fatty acids are linked to cardiovascular disease. APPROACH AND RESULTS: We found that administration of palmitate, a major saturated free fatty acid, to mice markedly aggravated neointima formation induced by carotid artery ligation and that the neointima primarily consisted of phenotypically modulated smooth muscle cells (SMCs). In cultured SMCs, palmitate-induced phenotypic modulation was characterized by downregulation of SMC differentiation markers, such as SM α-actin and SM-myosin heavy chain, and upregulation of mediators involved in inflammation and remodeling of the vessel wall, such as platelet-derived growth factor B and matrix metalloproteinases. We also found that palmitate induced the expression of proinflammatory genes via a novel toll-like receptor 4/myeloid differentiation primary response 88/nuclear factor-κB/NADPH oxidase 1/reactive oxygen species signaling pathway: nuclear factor-κB was activated by palmitate via toll-like receptor 4 and its adapter, MyD88, and once active, it transactivated Nox1, encoding NADPH oxidase 1, a major reactive oxygen species generator in SMCs. Pharmacological inhibition and small interfering RNA-mediated knockdown of the components of this signaling pathway mitigated the palmitate-induced upregulation of proinflammatory genes. More importantly, Myd88 knockout mice were resistant to palmitate-induced exacerbation of neointima formation. CONCLUSIONS: Palmitate seems to promote neointima formation by inducing inflammatory phenotypes in SMCs.
  • Koichi Kimura, Katsu Takenaka, Aya Ebihara, Kansei Uno, Hiroyuki Morita, Takashi Nakajima, Tetsuo Ozawa, Izumi Aida, Yosuke Yonemochi, Shinya Higuchi, Yasufumi Motoyoshi, Takashi Mikata, Idai Uchida, Tadayuki Ishihara, Tetsuo Komori, Ruriko Kitao, Tetsuya Nagata, Shin'ichi Takeda, Yutaka Yatomi, Ryozo Nagai, Issei Komuro
    International journal of cardiology 168 3 1900 - 4 2013年10月 [査読有り][通常論文]
     
    BACKGROUND: The reported prevalence of left ventricular noncompaction (LVNC) varies widely and its prognostic impact remains controversial. We sought to clarify the prevalence and prognostic impact of LVNC in patients with Duchenne/Becker muscular dystrophy (DMD/BMD). METHODS: We evaluated the presence of LNVC in patients with DMD/BMD aged 4-64 years old at the study entry (from July 2007 to December 2008) and prospectively followed-up their subsequent courses (n=186). The study endpoint was all-cause death and the presence of LVNC was blinded until the end of the study (median follow-up: 46 months; interquartile range: 41-48 months). RESULTS: There were no significant differences in baseline characteristics between patients with LVNC (n=35) and control patients without LVNC (n=151), with the exception of LV function. Patients with LVNC showed, in comparison with patients without LVNC, a significant negative correlation between age and LVEF (R=-0.7 vs. R=-0.4) at baseline; and showed a significantly greater decrease in absolute LVEF (-8.6 ± 4.6 vs. -4.3 ± 4.5, p<0.001) during the follow-up. A worse prognosis was observed in patients with LVNC (13/35 died) than in patients without LVNC (22/151 died, Log-rank p<0.001). Multivariate Cox analysis revealed that LVNC is an independent prognostic factor (relative hazard 2.67 [95% CI: 1.19-5.96]). CONCLUSION: LVNC was prevalent in patients with DMD/BMD. The presence of LVNC is significantly associated with a rapid deterioration in LV function and higher mortality. Neurologists and cardiologists should pay more careful attention to the presence of LVNC.
  • Tomoko Nakao, Hiroyuki Morita, Koji Maemura, Eisuke Amiya, Tsukasa Inajima, Yuichiro Saito, Masafumi Watanabe, Ichiro Manabe, Masahiko Kurabayashi, Ryozo Nagai, Issei Komuro
    Journal of pineal research 55 3 287 - 93 2013年10月 [査読有り][通常論文]
     
    Melatonin is well known to have a beneficial effect on the cardiovascular system, but it remains to be elucidated whether melatonin has a therapeutic effect on the vascular damage induced by the potential vasoactive substance angiotensin II (Ang II). In this study, the effects of melatonin on Ang II-induced vascular endothelial damage were investigated. In cultured vascular endothelial cells, Ang II stimulation increased ROS generation and inhibited eNOS phosphorylation (Ser1177), both of which were clearly restored by pretreatment with melatonin. The translocation of p47(phox) subunit of NADPH oxidase from the cytosol to plasma membrane was promoted in Ang II-treated vascular endothelial cells, which was canceled by melatonin pretreatment. In Ang II-infused rats, increased ROS generation in the aortic wall and impaired endothelial function of the aortic ring were observed, which were rescued by coadministration of melatonin. In vasculature, melatonin receptor agonist ramelteon had the antioxidative effect in the same manner as melatonin by itself. These findings suggest that melatonin directly ameliorates Ang II-induced vascular endothelial damage partly via its antioxidative properties, providing with us the potential rationale for clinical application of melatonin to the prevention from cardiovascular diseases.
  • Eriko Hasumi, Hiroshi Iwata, Takahide Kohro, Ichiro Manabe, Koichiro Kinugawa, Naho Morisaki, Jiro Ando, Daigo Sawaki, Masao Takahashi, Hideo Fujita, Hiroshi Yamashita, Junya Ako, Yasunobu Hirata, Issei Komuro, Ryozo Nagai
    International journal of cardiology 168 2 1429 - 34 2013年09月 [査読有り][通常論文]
     
    BACKGROUND: Restenosis after percutaneous coronary intervention (PCI) is still a great concern even in the recent drug-eluting stent (DES) era. As less invasive and sensitive parameter to detect restenosis is needed, this study was aimed to assess whether the clinical implication of temporal change in plasma BNP levels might be a useful indicator of restenosis after DES implantation. METHODS AND RESULTS: 847 consecutive patients who underwent elective PCI using silorimus-eluting sent (SES) between 2005 and 2009 were analyzed. Primary endpoint was subsequent target-lesion revascularization (TLR) after PCI. There was no significant difference in either baseline (TLR+vs. TLR-: 107.2 ± 172.2 vs. 96.2 ± 175.5 pg/mL, P=0.53) or follow-up plasma B-type natriuretic peptide (BNP) levels (TLR+vs. TLR-: 88.6 ± 111.6 vs. 68.5 ± 226.0 pg/mL, P=0.35) between patients with and without subsequent TLR. Conversely, ratio of follow-up to baseline BNP was significantly higher in patients with TLR (TLR+vs. TLR-: 1.55 ± 1.58 vs. 1.07 ± 1.04, P<0.001). Multivariate analysis using logistic regression showed log transformed BNP-ratio was an independent predictor of TLR (adjusted odds ratio (aOR): 1.94, 95%CI: 1.42-2.66, P<0.001). A closer relationship between BNP elevation greater than 2-fold and subsequent TLR was found (aOR: 2.69, 95%CI: 1.27-5.69, P<0.009). Furthermore, propensity score matching analysis showed that the incidence of subsequent TLR was significantly higher in patients with BNP elevation (P<0.001). CONCLUSION: Serial measurement of plasma BNP levels and its change might be a useful approach to predict restenosis in patients without typical chest symptoms receiving SES.
  • Kenjiro Kimura, Ryozo Nagai
    Nihon Naika Gakkai zasshi. The Journal of the Japanese Society of Internal Medicine 102 9 2284 - 2284 2013年09月 [査読有り][通常論文]
  • Hirotaka Fujimoto, Toru Suzuki, Kenichi Aizawa, Daigo Sawaki, Junichi Ishida, Jiro Ando, Hideo Fujita, Issei Komuro, Ryozo Nagai
    Clinical chemistry 59 9 1330 - 7 2013年09月 [査読有り][通常論文]
     
    BACKGROUND: Restenosis, a condition in which the lesion vessel renarrows after a coronary intervention procedure, remains a limitation in management. A surrogate biomarker for risk stratification of restenosis would be welcome. B-type natriuretic peptide (BNP) is secreted in response to pathologic stress from the heart. Its use as a biomarker of heart failure is well known; however, its diagnostic potential in ischemic heart disease is less explored. Recently, it has been reported that processed forms of BNP exist in the circulation. We hypothesized that circulating processed forms of BNP might be a biomarker of ischemic heart disease. METHODS: We characterized processed forms of BNP by a newly developed mass spectrometry-based detection method combined with immunocapture using commercial anti-BNP antibodies. RESULTS: Measurements of processed forms of BNP by this assay were found to be strongly associated with presence of restenosis. Reduced concentrations of the amino-terminal processed peptide BNP(5-32) relative to BNP(3-32) [as the index parameter BNP(5-32)/BNP(3-32) ratio] were seen in patients with restenosis [median (interquartile range) 1.19 (1.11-1.34), n = 22] vs without restenosis [1.43 (1.22-1.61), n = 83; P < 0.001] in a cross-sectional study of 105 patients undergoing follow-up coronary angiography. A sensitivity of 100% to rule out the presence of restenosis was attained at a ratio of 1.52. CONCLUSIONS: Processed forms of BNP may serve as viable potential biomarkers to rule out restenosis.
  • Rikuta Hamaya, Masahito Ogawa, Jun-ichi Suzuki, Naho Kobayashi, Yasunobu Hirata, Ryozo Nagai, Issei Komuro, Mitsuaki Isobe
    Expert opinion on investigational drugs 22 9 1095 - 106 2013年09月 [査読有り][通常論文]
     
    BACKGROUND: Neointimal hyperplasia after the percutaneous coronary intervention is still a clinically serious problem, associated with the risk of thrombosis due to delayed reendothelization. Peroxisome proliferator-activated receptor-β/δ (PPAR-β/δ) belongs to a family of ligand-activated transcription factors. OBJECTIVES: In this study, we investigated the effects of GW-0742, a synthetic high-affinity PPAR-β/δ agonist, on neointimal hyperplasia after arterial injury. Using C57BL/6J mice, we made a wire-injury model and intraperitoneally injected GW-0742 or vehicle once a day. The arteries were harvested for pathological and molecular analysis on day 14 after injury. In vitro, vascular smooth muscle cells (VSMCs), macrophages and human umbilical vein endothelial cells (HUVECs) were cultured, and GW-0742 effects on the cells proliferation were measured. RESULTS: The vehicle-treated injured arteries showed significantly thickened intima, while GW-0742 suppressed it. GW-0742 significantly suppressed IL-6 protein production, the expression of proliferating cell nuclear antigen in the neointima and enhanced CD31 expression. In vitro, GW-0742 attenuated VSMC proliferation triggered by cytokines or macrophages. The drug also induced endothelial regeneration after denudation injury. CONCLUSION: The data suggest that the PPAR-β/δ agonist is effective for atten- uation of neointimal hyperplasia by suppressing VSMC proliferation and accelerating reendothelization.
  • Ryota Sakurai, Bon-Kwon Koo, Hideaki Kaneda, Heidi N. Bonneau, Ryozo Nagai
    INTERNATIONAL JOURNAL OF CARDIOLOGY 167 5 2250 - 2258 2013年09月 [査読有り][通常論文]
     
    Background: The effects of cilostazol added to aspirin and clopidogrel (triple antiplatelet therapy: TAT) on clinical outcomes after drug-eluting stent (DES) implantation are unknown. Methods: We conducted a meta-analysis of randomized controlled trials (RCTs) comparing TAT with aspirin and clopidogrel (dual antiplatelet therapy: DAT) in DES patients. Clinical end points were target lesion (TLR) and/or vessel (TVR) revascularization, death, myocardial infarction (MI), stent thrombosis (ST), bleeding, rash, gastrointestinal (GI) side effects, and drug discontinuation. We calculated the pooled estimate based on a fixed-effects model using Peto odds ratio (OR) for rare events. If heterogeneity was observed across an individual RCT, an analysis based on a random-effects model was performed. Results: Eight RCTs were included in this meta-analysis, involving 3590 patients (TAT: DAT = 1800: 1790). Up to 24 months, TAT showed a significant reduction in TLR (OR: 0.58, 95% confidence interval (CI): 0.43 to 0.78, p<0.001) and TVR (OR: 0.58, 95% CI: 0.40 to 0.83, p = 0.003) compared with DAT. The incidence of death, MI, ST, or overall or major bleeding was comparable between the 2 groups, whereas the proportion of rash (OR: 2.50, 95% CI: 1.52 to 4.10, p<0.001), GI side effects (OR: 3.14, 95% CI: 1.79 to 5.50, p<0.001), or drug discontinuation (OR: 6.81, 95% CI: 2.12 to 21.86, p<0.001) was higher in TAT than DAT. Conclusions: In this meta-analysis, TAT was associated with significantly effective outcomes for TLR and TVR without any increase in major adverse events but was associated with tolerance issues compared with DAT after DES implantation. (C) 2012 Elsevier Ireland Ltd. All rights reserved.
  • Toru Suzuki, Ryozo Nagai
    Quantitative Proteome Analysis: Methods and Applications 67 - 83 2013年07月 [査読有り][通常論文]
  • Aiko Sakamoto, Makiko Hongo, Kyoko Furuta, Kan Saito, Ryozo Nagai, Nobukazu Ishizaka
    International Journal of Cardiology 167 2 409 - 415 2013年07月 [査読有り][通常論文]
     
    We previously showed that administration of angiotensin II to rats causes fibrosis and lipid accumulation in the heart. In the current study, we examined the effect of pioglitazone, an agonist of peroxisome proliferator activated receptor-γ, on angiotensin II-induced intracardiac lipid accumulation and cardiac dysfunction. Pioglitazone, given orally at a dose of 2.5 mg/kg/d, reduced cardiac triglyceride content and suppressed lipid deposition in the heart of angiotensin II-induced hypertensive rats without affecting angiotensin II-induced upregulation of lipogenic gene expression. Histological examination showed that pioglitazone reduced the area of cardiac fibrosis and iron deposition in the heart of angiotensin II-treated rats. Expression of an antioxidative molecule, heme oxygenase-1, was increased by angiotensin II infusion, and pioglitazone treatment preserved expression of HO-1. Angiotensin II increased the superoxide signals detected by dihydroethidium staining in myocardial cells with lipid deposition, and this increase was suppressed by pioglitazone. Cardiac function was analyzed in an ex vivo isolated cardiac perfusion system. It was found that pioglitazone improved both the systolic and diastolic cardiac performance, which was weakened by angiotensin II infusion, after transient ischemia and reperfusion. These findings collectively suggest that pioglitazone treatment ameliorated the histological and functional cardiac damage induced by angiotensin II infusion, the mechanism of which may be related to the antioxidative action of pioglitazone. © 2013 Elsevier Ireland Ltd. All rights reserved.
  • Tetsuya Saito, Norihiko Takeda, Eisuke Amiya, Tomoko Nakao, Hajime Abe, Hiroaki Semba, Katsura Soma, Katsuhiro Koyama, Yumiko Hosoya, Yasushi Imai, Takayuki Isagawa, Masafumi Watanabe, Ichiro Manabe, Issei Komuro, Ryozo Nagai, Koji Maemura
    FEBS letters 587 14 2179 - 85 2013年07月 [査読有り][通常論文]
     
    Vascular endothelial growth factor-A (VEGF-A) is one of the major angiogenic factors, and its actions are primarily mediated through its two membrane receptors, VEGFR-1 and VEGFR-2. A soluble form of VEGFR-1 (sVEGFR-1) sequesters the free form of VEGF-A, and acts as a potent anti-angiogenic factor. While sVEGFR-1 is synthesized as a splice variant of VEGF-R1 gene, the interactions between VEGF-A and sVEGFR-1 remain largely unknown. Here, we show that VEGF-A upregulates sVEGF-R1 expression in human vascular endothelial cells but leaves full-length VEGF-R1 expression unchanged, and that this induction was dependent on the VEGFR-2-protein kinase C-MEK signaling pathway. The VEGF-A-induced sVEGFR-1 upregulation can operate as a negative feedback system, which if modulated can become a novel therapeutic target for regulating pathological angiogenesis.
  • Motoki Inoue, Makoto Sasaki, Yasuyuki Katada, Katsuhito Fujiu, Ichiro Manabe, Ryozo Nagai, Tetsushi Taguchi
    Journal of biomedical materials research. Part A 101 7 2049 - 57 2013年07月 [査読有り][通常論文]
     
    Biodegradable composite matrices comprising poly-(L-lactic acid) (PLLA) and citric acid-crosslinked alkali-treated gelatin (AlGelatin) with endothelialization, antithrombogenic, and drug release properties were prepared. The characterization of composite matrices with various mixing ratios was performed by evaluating their swelling ratio, endothelial cell culture, antithrombogenic tests, and drug release behavior. Tamibarotene (Am80), which specifically inhibits smooth muscle cell proliferation, was employed as the drug. The swelling ratio of composite matrices decreased as the PLLA content decreased. The number of endothelial cells cultured on the surfaces of composite matrices was maximal at the PLLA/AlGelatin-TSC ratio of 80/20. Antithrombogenic tests revealed that the levels of platelets and fibrin network formation decreased as the AlGelatin-TSC content increased. The Am80 release test indicated that the release rate decreased as PLLA content increased. Using the resulting composite matrix, Am80-eluting stents possessing a smooth surface and a coating thickness of ∼15 μm were successfully obtained. Am80 was continuously released from the resulting stent at ∼40%, up to 28 days without burst release. Therefore, Am80-eluting stent with its antithrombogenic and endothelialization properties has great potential for clinical use.
  • Katsuhito Fujiu, Ryozo Nagai
    Basic research in cardiology 108 4 357 - 357 2013年07月 [査読有り][通常論文]
     
    The heart contains various types of cells, including cardiomyocytes, cardiac fibroblasts, many kinds of immune cells and vascular cells. Initial studies mainly focused on cardiomyocytes, which directly reflect the contractile function of the heart. Recently, pivotal functions of cardiac fibroblasts have been revealed in the maintenance of cardiac function, physiological cardiac remodeling after heart stress and pathological remodeling using genetically engineered mouse models, like the fibroblast-specific gene knockout mouse, bone marrow transplantation and immune cell-specific gene knockout. Moreover, chronic inflammation is considered to be a basic pathological mechanism that underlies various diseases, including heart failure. In the development of heart failure, the contributions of immune cells like T lymphocytes and monocyte/macrophage lineage cells have been also reported. Immune cells have diverse and multiple functions in regulating both pro-inflammatory effects and the resolution of heart failure. On the one hand, immune cells have protective effects to compensate for and overcome heart stresses. On the other hand, they also contribute to sustained inflammation and result in the development of heart failure. These observations prompted a shift in the heart-related studies to include the complex communications between cardiomyocytes and other kinds of cardiac cells, including inflammatory cells residing in or recruited to the heart. This review will summarize the current knowledge regarding cell-cell interactions during cardiac remodeling and the development of heart failure. We will especially focus on the interactions among cardiomyocytes, cardiac fibroblasts and immune cells.
  • Ryota Sakurai, Tsukasa Inajima, Hideaki Kaneda, Ryozo Nagai, Hideki Hashimoto
    INTERNATIONAL JOURNAL OF CARDIOLOGY 167 1 162 - 167 2013年07月 [査読有り][通常論文]
     
    Background: Sirolimus-eluting stents (SES) have demonstrated more favorable outcomes compared with bare metal stents (BMS) for ST-segment elevation myocardial infarction (STEMI) within medium term follow up in randomized controlled trials (RCT). However, long-term outcomes remain unknown. Methods: We conducted a meta-analysis of RCT comparing SES with BMS in STEMI patients at long-term follow up, defined as 2 years or more after primary percutaneous coronary intervention (PCI). The clinical end points of our interest were death, recurrent myocardial infarction (MI), definite stent thrombosis (ST), and target lesion revascularization (TLR). We calculated the pooled estimate based on a fixed-effects model using Peto odds ratio (OR) for rare events. If heterogeneity was observed across an individual RCT, an analysis based on a random-effects model was performed. Results: Four RCT were included in this study, involving 1304 patients (656 patients randomized to SES and 648 patients to BMS). Up to 4 years, SES showed a significant reduction in not only TLR (OR: 0.44, 95% confidence interval (CI): 0.31 to 0.62, p<0.001) but also mortality (OR: 0.62, 95% CI: 0.39 to 1.00, p = 0.049) compared with BMS. In contrast, the proportions of recurrent MI (OR: 0.82, 95% CI: 0.52 to 1.28, p = 0.378) and definite ST (OR: 1.13, 95% CI: 0.56 to 2.27, p = 0.740) were comparable between the 2 groups. Conclusions: In this meta-analysis of long-term RCT, primary PCI for STEMI patients with SES was associated with a decrease in mortality as well as TLR without an increase in recurrent MI or definite ST compared with BMS. (C) 2011 Elsevier Ireland Ltd. All rights reserved.
  • 心血管病の予知を探る バイオマーカーを含めて 血中の多価不飽和脂肪酸分画と急性冠症候群との関連 多施設共同研究の結果から
    西崎 祐史, 島田 和典, 谷 樹昌, 小川 崇之, 安東 治郎, 高橋 政夫, 山本 雅人, 篠崎 智大, 宮内 克己, 長尾 建, 平山 篤志, 吉村 道博, 小室 一成, 永井 良三, 代田 浩之
    日本動脈硬化学会総会プログラム・抄録集 45回 137 - 137 (一社)日本動脈硬化学会 2013年06月
  • Masami Ochi, Atsushi Amano, Hirokuni Arai, Tohru Asai, Hiroyuki Daida, Hisayoshi Fujiwara, Taiko Horii, Takaaki Isshiki, Michio Kawasuji, Takeshi Kimura, Junjiro Kobayashi, Izuru Masuda, Hiroshi Niinami, Hiroshi Nishida, Kazuhiko Nishigaki, Satoshi Ogawa, Takayuki Ohno, Hitoshi Okabayashi, Yoshitaka Okamura, Ryuzo Sakata, Teruo Shiba, Hisayoshi Suma, Tetsuya Sumiyoshi, Shinichi Takamoto, Tadashi Tashiro, Hitoshi Yaku, Fumio Yamamoto, Tsutomu Yamazaki, Go Watanabe, Kiyoshi Doi, Masahiro Fujii, Michiya Hanyu, Soichiro Kitamura, Hiroyuki Nakajima, Masaru Nishimi, Tomoaki Suzuki, Koichi Tabayashi, Osamu Tagusari, Shigeyuki Tomita, Atsushi Hirayama, Kanji Kawachi, Nobuya Koyama, Ryozo Nagai
    CIRCULATION JOURNAL 77 6 1608 - 1641 2013年06月 [査読有り][通常論文]
  • Takahide Kohro, Tsutomu Yamazaki, Hiroki Sato, Kazuhiko Ohe, Ryozo Nagai
    Hypertension Research 36 6 559 - 563 2013年06月 [査読有り][通常論文]
     
    The Japanese Society of Hypertension (JSH) updated its hypertension management guidelines in 2009. One of the most significant changes with respect to the 2004 version was the stance towards the use of diuretics: in 2004, their use was cautioned against, but in 2009, it was actively promoted. The purpose of this study was to measure the impact of this change in guidelines on prescription patterns for antihypertensive medications, and to investigate the overall trend in the use of antihypertensives. We used monthly claims data obtained from a database company. Data of patients who were 20 or more years old and prescribed antihypertensives were extracted and analyzed. There were 66 223 patients who were prescribed antihypertensives (mean age 53.6±11.0). Of these, 38 130 were men and 28 093 were women. The two most prescribed classes of antihypertensives were angiotensin receptor blockers, whose usage steadily increased over a 7-year period, and calcium channel blockers. Prescriptions for antihypertensives in these two classes were also more likely to be continued than those for other antihypertensive classes. The prescription rate for diuretics increased from December 2006 (P< 0.0001), but the rate of increase was the same before and after 2009 (P=0.09). The clinical guidelines published in 2009 had no apparent impact on the trend of diuretic prescriptions, despite the radical change in stance concerning the use of antihypertensives. Further effort to disseminate the content of these guidelines, so that it is reflected in actual clinical practice, may be warranted. © 2013 The Japanese Society of Hypertension.
  • Shota Fukuda, Kenei Shimada, Masatoshi Fujita, Minoru Yoshiyama, Junichi Yoshikawa, Takahide Kohro, Doubun Hayashi, Tsutomu Yamazaki, Ryozo Nagai
    Journal of Cardiology 61 6 387 - 392 2013年06月 [査読有り][通常論文]
     
    Background: Although increased attention is given to assess absolute values of serum cholesterol profiles as optimal markers for preventing future cardiovascular (CV) events, changes in cholesterol profiles also have the potential to be associated with CV disease outcome in Japanese patients with acute coronary syndrome (ACS). Methods: From the database of the Japanese Coronary Artery Disease (JCAD) study, 2664 patients with ACS who had serial measurements of serum cholesterol profile parameters were enrolled. These patients were followed-up for a mean period of 2.7 years. The endpoint was all CV events. Baseline clinical characteristics of patients with and without CV events were adjusted by the propensity score matching analysis. Results: None of the serum absolute cholesterol profiles at baseline and 6 months later was associated with CV events, except for baseline serum total cholesterol level. However, large improvements in cholesterol profiles correlated with better CV disease outcome. Conclusions: This subanalysis of JCAD demonstrated the importance of serial assessment of serum cholesterol profiles for secondary prevention of CV events in Japanese patients with ACS. Changes in serum cholesterol profiles, rather than their absolute values, correlated with future CV events. © 2013.
  • Eisuke Amiya, Masafumi Watanabe, Norihiko Takeda, Tetsuya Saito, Taro Shiga, Yumiko Hosoya, Tomoko Nakao, Yasushi Imai, Ichiro Manabe, Ryozo Nagai, Issei Komuro, Koji Maemura
    The Journal of biological chemistry 288 20 14497 - 509 2013年05月 [査読有り][通常論文]
     
    Vascular endothelial function is impaired in hypercholesterolemia partly because of injury by modified LDL. In addition to modified LDL, free cholesterol (FC) is thought to play an important role in the development of endothelial dysfunction, although the precise mechanisms remain to be elucidated. The aim of this study was to clarify the mechanisms of endothelial dysfunction induced by an FC-rich environment. Loading cultured human aortic endothelial cells with FC induced the formation of vesicular structures composed of FC-rich membranes. Raft proteins such as phospho-caveolin-1 (Tyr-14) and small GTPase Rac were accumulated toward FC-rich membranes around vesicular structures. In the presence of these vesicles, angiotensin II-induced production of reactive oxygen species (ROS) was considerably enhanced. This ROS shifted endothelial NOS (eNOS) toward vesicle membranes and vesicles with a FC-rich domain trafficked toward perinuclear late endosomes/lysosomes, which resulted in the deterioration of eNOS Ser-1177 phosphorylation and NO production. Angiotensin II-induced ROS decreased the bioavailability of eNOS under the FC-enriched condition.
  • Lars P Bechmann, Diana Vetter, Junichi Ishida, Rebekka A Hannivoort, Ursula E Lang, Peri Kocabayoglu, M Isabel Fiel, Ursula Muñoz, Gillian L Patman, Fengxia Ge, Shoshana Yakar, Xiaosong Li, Loranne Agius, Young-Min Lee, Weijia Zhang, Kei Yiu Hui, Despina Televantou, Gary J Schwartz, Derek LeRoith, Paul D Berk, Ryozo Nagai, Toru Suzuki, Helen L Reeves, Scott L Friedman
    Journal of hepatology 58 5 1000 - 6 2013年05月 [査読有り][通常論文]
     
    BACKGROUND & AIMS: Dysregulated glucose homeostasis and lipid accumulation characterize non-alcoholic fatty liver disease (NAFLD), but underlying mechanisms are obscure. We report here that Krüppel-like factor 6 (KLF6), a ubiquitous transcription factor that promotes adipocyte differentiation, also provokes the metabolic abnormalities of NAFLD by post-transcriptionally activating PPARα-signaling. METHODS: Mice with either hepatocyte-specific depletion of KLF6 ('ΔHepKlf6') or global KLF6 heterozygosity (Klf6+/-) were fed a high fat diet (HFD) or chow for 8 or 16 weeks. Glucose and insulin tolerance tests were performed to assess insulin sensitivity. Overexpression and knockdown of KLF6 in cultured cells enabled the elucidation of underlying mechanisms. In liver samples from a cohort of 28 NAFLD patients, the expression of KLF6-related target genes was quantified. RESULTS: Mice with global- or hepatocyte-depletion of KLF6 have reduced body fat content and improved glucose and insulin tolerance, and are protected from HFD-induced steatosis. In hepatocytes, KLF6 deficiency reduces PPARα-regulated genes (Trb3, Pepck) with diminished PPARα protein but no change in Pparα mRNA, which is explained by the discovery that KLF6 represses miRNA 10b, which leads to induction of PPARα. In NAFLD patients with advanced disease and inflammation, the expression of miRNA 10b is significantly downregulated, while PEPCK mRNA is upregulated; KLF6 mRNA expression also correlates with TRB3 as well as PEPCK gene expression. CONCLUSIONS: KLF6 increases PPARα activity, whereas KLF6 loss leads to PPARα repression and attenuation of lipid and glucose abnormalities associated with a high fat diet. The findings establish KLF6 as a novel regulator of hepatic glucose and lipid metabolism in fatty liver.
  • Ryozo Nagai
    European heart journal 34 18 1314 - 5 2013年05月 [査読有り][通常論文]
  • Atsuko Nakayama, Hiroyuki Morita, Jiro Ando, Hideo Fujita, Hiroshi Ohtsu, Ryozo Nagai
    Heart and Vessels 28 3 292 - 300 2013年05月 [査読有り][通常論文]
     
    Recent clinical studies reported the drug interaction between proton-pump inhibitors (PPI) and clopidogrel, which remains controversial. The aim of this study was to determine whether the concurrent use of PPI with clopidogrel or ticlopidine is associated with increased risk for adverse cardiovascular outcomes in patients with coronary artery disease (CAD) undergoing percutaneous coronary intervention (PCI). In this retrospective cohort study, we assessed the cardiovascular outcomes associated with the concurrent use of PPI and clopidogrel or ticlopidine in the well-characterized 1286 patients with CAD undergoing PCI in the University of Tokyo Hospital. In the Japanese patients with CAD undergoing PCI, the concurrent use of PPI was significantly associated with increased risk for major adverse cardiovascular events in the ticlopidine users (hazard ratio 2.63 95 % confidence interval 1.65-4.18 P < 0.001), but not in the clopidogrel users. In the clopidogrel users as well as the ticlopidine users, PPI use did not affect the occurrence of target lesion revascularization, but significantly increased the risk for new lesion formation in the coronary arteries, which required subsequent revascularization. The adverse cardiovascular effects of the concurrent use of PPI and ticlopidine were identified in the patients with CAD undergoing PCI. Also, new lesion formation in the coronary arteries was shown to be increased when PPI was coprescribed for the thienopyridine users. © 2012 Springer.
  • Hiroshi Okamoto, Masatsugu Hori, Masunori Matsuzaki, Hiroyuki Tsutsui, Tsutomu Yamazaki, Ryozo Nagai, Tsutomu Yoshikawa, Yasushi Fujio, Shinpei Nonen, Junichi Azuma, Tohru Izumi, Yasuo Ohashi, Akira Kitabatake
    International Journal of Cardiology 164 2 238 - 244 2013年04月 [査読有り][通常論文]
     
    AbstractBackground In chronic heart failure (CHF), it remains unclear whether the minimal dose of beta-blockade is related to survival benefits and which parameter predicts morbidity and mortality. We sought to determine the minimal dose related to survival benefits by comparing the efficacy and safety of three doses of carvedilol and the best predictive parameter for effective outcomes in Japanese patients with CHF. Methods In this prospective, randomized, stratified trial, 364 patients with mild to moderate CHF were assigned to a daily carvedilol dose of 2.5, 5, or 20 mg, plus optimal standard therapy. Findings During the mean 3-year follow-up, resting heart rate (HR) and BNP were significantly reduced with dose-response relations in the early period but without dose-response relations in the late period. The LVEF and the LVDd were increased and decreased, respectively, without a dose-response relation. No significant difference was seen in the composite primary endpoint of all-cause mortality and hospitalization for cardiovascular diseases and heart failure. Multivariate analysis indicated early decreases in HR and BNP predicted long-term outcomes. However, adverse events increased dose-dependently. Among 237 polymorphisms in 87 heart failure-related genes, the osteopontin G-156 del genotype was associated with an event-free survival rate (Wilcoxon test, P = 0.030). Conclusions A low carvedilol dose is effective if the HR and/or plasma BNP has been reduced. Carvedilol therapy should be guided by reductions in HR and/or BNP, especially by initial HR reduction, but not only by its dose. OPN might be a surrogate genetic marker for long-term event-free survival. © 2012 Elsevier Ireland Ltd.
  • ルテオリン経口摂取の腹部大動脈瘤形成抑制作用
    中山 敦子, 森田 啓行, 小室 一成, 永井 良三
    日本臨床分子医学会学術総会プログラム・抄録集 50回 58 - 58 日本臨床分子医学会 2013年04月
  • JCAD研究において急性冠症候群患者の血清cholesterol値の変化は将来の心血管イベントと関連する(Changes in Serum Cholesterol Levels are Associated with Future Cardiovascular Events in Patients with Acute Coronary Syndrome in JCAD Study)
    Fukuda Shota, Shimada Kenei, Fujita Masatoshi, Yoshiyama Minoru, Yoshikawa Junichi, Kohro Takahide, Hayashi Dobun, Yamazaki Tsutomu, Nagai Ryozo
    Circulation Journal 77 Suppl.I 259 - 259 2013年03月
  • Teruhiko Imamura, Koichiro Kinugawa, Masaru Hatano, Naoko Kato, Shun Minatsuki, Hironori Muraoka, Toshiro Inaba, Hisataka Maki, Taro Shiga, Atsushi Yao, Shunei Kyo, Minoru Ono, Ryozo Nagai
    Journal of Artificial Organs 16 1 101 - 104 2013年03月 [査読有り][通常論文]
     
    No medical treatment has been established to ameliorate pulmonary hypertension (PH) due to left heart disease. Heart transplantation (HTx) is thus far the definitive therapy for stage D heart failure, but concomitant PH is one of the major risk factors for death after HTx. Recently, implantation of a left ventricular assist device (LVAD) has been reported to improve PH and has become a major bridge tool for HTx. We experienced a rare case with persistent PH even after the implantation of a continuous-flow LVAD. The administration of an endothelin receptor antagonist, bosentan, significantly decreased pulmonary vascular resistance. Combination therapy with LVAD implantation and anti-PH medication may be useful for patients with stage D heart failure complicated with severe PH. © 2012 The Japanese Society for Artificial Organs.
  • Norihiko Ashigaki, Jun-Ichi Suzuki, Masahito Ogawa, Ryo Watanabe, Norio Aoyama, Naho Kobayashi, Tomoya Hanatani, Asuka Sekinishi, Hirofumi Zempo, Yuko Tada, Chisato Takamura, Kouji Wakayama, Yasunobu Hirata, Ryozo Nagai, Yuichi Izumi, Mitsuaki Isobe
    American journal of physiology. Heart and circulatory physiology 304 5 H740-8 - H748 2013年03月 [査読有り][通常論文]
     
    Periodontitis is one of the most common infections in humans. Recently, published reports assert that periodontitis is associated with cardiovascular disease. Although it is said that viral, bacterial infections and autoimmune diseases may be the cause of myocarditis, the pathogenesis of it remains unclear. The aim of this study was to investigate the influence of a periodontal pathogen on experimental autoimmune myocarditis (EAM). Porphyromonas gingivalis (P.g.), PBS as a control, were injected into the mice. Histopathological and immunohistochemical analyses were performed. We examined heart mRNA levels using quantitative RT-PCR. The anti-P.g. IgG antibody level in plasma samples of the P.g.-injected group significantly increased compared with the PBS-injected group. Histopathological analysis detected that the myocarditis-affected areas and the fibrotic area in the P.g.-injected EAM group significantly increased compared with the PBS-injected EAM group (P < 0.05). Immunohistochemical analysis detected that more CD11b-positive cells were shown in the heart of the P.g.-injected EAM group compared with the PBS EAM-injected group (P < 0.05). Hearts from the P.g.-injected EAM group showed significantly increased expression of monocyte chemoattractant protein-1, IFN-γ, and matrix metalloproteinase-9 (MMP-9) mRNA compared with the hearts from the PBS-injected EAM group (P < 0.05). On day 7, serum levels of IL-6 were significantly enhanced in the P.g.-injected EAM group compared with the PBS-injected EAM group (P < 0.05). These results showed that P.g. injection could deteriorate EAM in mice through CD11b-positive cells, cytokines, and MMP-9 expression.
  • Jun-Ichi Okada, Teruyoshi Sasaki, Takumi Washio, Hiroshi Yamashita, Taro Kariya, Yasushi Imai, Machiko Nakagawa, Yoshimasa Kadooka, Ryozo Nagai, Toshiaki Hisada, Seiryo Sugiura
    PACE-PACING AND CLINICAL ELECTROPHYSIOLOGY 36 3 309 - 321 2013年03月 [査読有り][通常論文]
     
    Background Recent studies, supported by advances in computer science, have successfully simulated the excitation and repolarization processes of the heart, based on detailed cell models of electrophysiology and implemented with realistic morphology. Methods In this study, we extend these approaches to simulate the body surface electrocardiogram (ECG) of specific individuals. Patient-specific finite element models of the heart and torso are created for four patients with various heart diseases, based on clinical data including computer tomography, while the parallel multi-grid method is used to solve the dynamic bi-domain problem. Personalization procedures include demarcation of nonexcitable tissue, allocation of the failing myocyte model of electrophysiology, and modification of the excitation sequence. In particular, the adjustment of QRS morphology requires iterative computations, facilitated by the simultaneous visualization of the propagation of excitation in the heart, average QRS vector in the torso, and 12-lead ECG. Results In all four cases we obtained reasonable agreement between the simulated and actual ECGs. Furthermore, we also simulated the ECGs of three of the patients under bi-ventricular pacing, and once again successfully reproduced the actual ECG morphologies. Since no further adjustments were made to the heart models in the pacing simulations, the good agreement provides strong support for the validity of the models. Conclusions These results not only help us understand the cellular basis of the body surface ECG, but also open the possibility of heart simulation for clinical applications. (PACE 2013; 36:309-321)
  • Yumiko Yamamoto, Toshihiro Morita, Tomofumi Tanaka, Kenichi Ikeda, Hironobu Kikuchi, Gaku Oguri, Fumitaka Nakamura, Toshiaki Nakajima, Ryozo Nagai
    European journal of pharmacology 701 1-3 14 - 9 2013年02月 [査読有り][通常論文]
     
    There is a possibility thrombus formation is closely involved in sudden cardiac death. Amiodarone, a potassium channel inhibitor, is known to reduce mortality in patients with coronary artery disease or low ejection fraction, having antithrombotic actions. Using human monocytic THP-1 cells, we investigated the effects of amiodarone on tissue factor mRNA and protein expression. The involvement of the two main potassium channels existing in THP-1 cells was also investigated. Amiodarone (10μM) significantly and almost completely inhibited the increase of tissue factor mRNA and protein expression induced by tumor necrosis factor-α (100ng/ml). The inhibitory effects of amiodarone on tissue factor mRNA expression showed dose-dependency. Margatoxin (1nM), a selective blocker of voltage-dependent potassium channel Kv1.3, also inhibited tissue factor protein expression, but didn't significantly inhibit mRNA expression. Ba(2+), a blocker of inwardly rectifying potassium channel Kir2.1, partly inhibited the increase of tissue factor mRNA and protein expression. This is the first study that shows amiodarone inhibits tissue factor expression in monocytic cells, by inhibiting mRNA transcription. The result may correlate with the facts amiodarone has antithrombotic actions in patients under extraordinary conditions where thrombus formation is enhanced. The inhibitory effects of amiodarone on tissue factor expression are drastic, different from those of margatoxin and Ba(2+). The result suggests amiodarone has an underlying mechanism to intensely inhibit tissue factor expression other than blocking Kv1.3 and Kir2.1.
  • Aiko Sakamoto, Mitsuhiro Fujishiro, Kazuhiko Koike, Ryozo Nagai, Nobukazu Ishizaka
    Journal of Cardiology 61 2 181 - 185 2013年02月 [査読有り][通常論文]
     
    Background: Although gastrointestinal (GI) complications are receiving more attention in cardiovascular patients owing to the widespread use of antithrombotic drugs, information seems to be limited over the prevalence of GI malignancies in those patients. Methods and results: The prevalence of malignant as well as non-malignant GI lesions diagnosed in cardiology inpatients was investigated. We retrospectively analyzed 274 cardiology inpatients who underwent upper and/or lower GI tract endoscopies. A total of 97 patients (35.4%) were taking multiple antithrombotic drugs and the mean number of antithrombotic drugs used was 1.19. Malignant neoplasm was found in 26 patients (9.5%), and non-malignant lesions (ulcers, adenomas, polyps) were found in 106 patients (38.7%). Multivariate analysis showed that antiplatelet drug usage was negatively (odds ratio [OR] 0.38, 95% confidence interval [CI] 0.16-0.91) whereas positive fecal occult blood test was positively (OR 4.44, 95% CI 1.44-13.66) associated with GI malignancies. On the other hand, for non-malignant GI lesions, both antiplatelet drug usage (OR 1.85, 95% CI 1.05-3.25) and positive fecal occult blood test (OR 1.99, 95% CI 1.14-3.47) were found to be positive predictors. Conclusions: During the 59-month study period, 26 and 106 patients were diagnosed to have GI malignancies and non-malignant GI lesions, respectively, among cardiology inpatients. Cardiology physicians should not overlook the possibility of GI malignancies in an era of multiple antithrombotic drug usage. © 2012 Japanese College of Cardiology.
  • Sugiura Seiryo, Washio Takumi, Okada Jun-ichi, Watanabe Hiroshi, Yamashita Hiroshi, Kariya Taro, Imai Yasushi, Nagai Ryozo, Kadooka Yoshimasa, Hosoi Akira, Watanabe Masahiro, Hirahara Takao, Yamazaki Takashi, Iwamura Takashi, Nakagawa Machiko, Hatanaka Kohei, Yoneda kazunori, Hisada Toshiaki
    生体医工学 51 M - 61-M-61 Japanese Society for Medical and Biological Engineering 2013年
  • Jun-ichi Suzuki, Masahito Ogawa, Yasunobu Hirata, Ryozo Nagai, Mitsuaki Isobe
    Tea in Health and Disease Prevention 1261 - 1272 2013年 [査読有り][通常論文]
  • Naoko Kato, Koichiro Kinugawa, Etsuko Nakayama, Akiko Hatakeyama, Takako Tsuji, Yumiko Kumagai, Issei Komuro, Ryozo Nagai
    International heart journal 54 4 228 - 33 2013年 [査読有り][通常論文]
     
    Knowledge about their own condition is important for patients with heart failure (HF). No valid, reliable, and easily administered instrument is available to measure this knowledge in clinical practice. In this study, a HF knowledge scale was developed, and its psychometric properties were tested. Items related to knowledge about HF were extracted from relevant guidelines. Content validity of the items was confirmed by an expert panel including a cardiologist and nurses specialized in treatment and care of patients with HF. A self-administered questionnaire was then distributed to 187 patients with HF (64.0 ± 12.1 years, males 69%). In 62% patients, a left ventricular ejection fraction of < 50% was identified. Exploratory factor analysis demonstrated the one-dimensionality of the 15-item HF knowledge scale. Mean score was 10.7 ± 3.0 (range, 0-15). Known-group validity testing revealed a significant difference in HF knowledge score between patients newly diagnosed with HF and patients experienced with HF (9.4 ± 3.2 versus 10.8 ± 2.9, P = 0.043). In addition, HF knowledge scale scores were correlated with HF self-care scores assessed by the European Heart Failure Self-Care Behavior Scale for evaluation of criterion validity (ρ = -0.304, P < 0.001). Cronbach's alpha was 0.79, and item-total correlation was 0.22-0.51, thereby suggesting that the reliability of the scale was acceptable. Acceptable validity and reliability were demonstrated for the HF knowledge scale developed in this study. This instrument could be useful in evaluation of patient knowledge about HF.
  • Yumiko Hosoya, Masafumi Watanabe, Masahiro Terashima, Eisuke Amiya, Tomoko Nakao, Akiko Hasegawa, Hironobu Hyodo, Jiro Ando, Tomoyuki Fujii, Ryozo Nagai, Issei Komuro
    International heart journal 54 2 119 - 22 2013年 [査読有り][通常論文]
     
    Amniotic fluid embolism (AFE) is a rare but devastating complication of pregnancy. Acute circulatory failure and obstetric disseminated intravascular coagulopathy are often associated with AFE and lead to poor prognosis of this syndrome. Although many reports of AFE and its cardiopulmonary complications exist, their etiology remains unknown. Classically, it was believed that the fatal cardiopulmonary complication in AFE is due to acute and severe pulmonary hypertension caused by critical obstruction of the pulmonary vessels by embolized amniotic fluid. However, recent hypotheses are suggesting that anaphylactic reaction or a cytokine effect induced by amniotic fluid is the main pathophysiological mechanism. We report a case in which cardiac magnetic resonance imaging was performed at the chronic stage of AFE. Late gadolinium enhancement (LGE) was detected at the mid-wall of the left ventricle with no evidence of pulmonary hypertension. This finding suggests that the pathophysiological mechanism of severe cardiac complications in AFE may include direct left ventricular myocardial injury through an immune reaction or cytokine release, rather than pulmonary embolism.
  • Naoko Kato, Koichiro Kinugawa, Teruhiko Imamura, Hironori Muraoka, Shun Minatsuki, Toshiro Inaba, Hisataka Maki, Taro Shiga, Masaru Hatano, Atsushi Yao, Issei Komuro, Ryozo Nagai
    Circulation Journal 77 4 1001 - 1008 2013年 [査読有り][通常論文]
     
    Background: The aim of this study was to examine trends of clinical outcome and to clarify surrogate markers when titrating β-blocker in heart failure patients with reduced left ventricular ejection fraction (HFrEF, LVEF < 50%). Methods and Results: Consecutive HFrEF patients starting on β-blocker were divided into 2 groups according to time of dose fixation attainment: before 31 December 2005 (group 1, n=108) or after 1 January 2006 (group 2, n=119). There were no significant differences in patient characteristics between the 2 groups at baseline. Betablocker fixed dose was higher with lower resting heart rate in group 2 (6.2±5.7 mg/day vs. 9.5±9.1 mg/day in carvedilol equivalent dose, P=0.001 74.2±11.1 beats/min vs. 70.2±9.7 beats/min, P=0.004). The rate of HF hospitalization and/ or all-cause death after 36 months was lower in group 2 than in group 1 (22% vs. 38%, P=0.011 hazard ratio, 0.90 P=0.012). Cox regression analysis showed that β-blocker ≥10 mg/day and achieved heart rate ≤71 beats/min predicted a better outcome (both P< 0.05). Conclusions: Recent improvement of clinical outcome among HFrEF patients may be attributable to the up-titration policy accompanying lowered heart rate. Resting heart rate ≤71 beats/min and β-blocker ≥10 mg/day (ie, 50% of the target dose for Japanese patients) could be surrogate markers when titrating β-blocker.
  • Teruhiko Imamura, Koichiro Kinugawa, Taro Shiga, Naoko Kato, Hironori Muraoka, Shun Minatsuki, Toshiro Inaba, Hisataka Maki, Masaru Hatano, Atsushi Yao, Shunei Kyo, Ryozo Nagai
    Circulation Journal 77 2 397 - 404 2013年 [査読有り][通常論文]
     
    Background: A newly-developed vasopressin type 2 receptor antagonist, tolvaptan (TLV), has a unique feature of diuresis, but the response to this drug can be unpredictable. Methods and Results: Data were collected from hospitalized patients with decompensated congestive heart failure who were administered TLV at 3.75-15 mg/day (n=61). A responder/non-responder to TLV was determined as having any increase/decrease in urine volume (UV) during the next 24 h after TLV treatment on the first day. Logistic regression analyses for increases in UV were performed, and independent predictors of the responder were the following: C1, baseline urine osmolality (U-OSM) > 352 mOsm/L and C2, %decrease in U-OSM > 26% at 4-6 h after TLV administration. Criteria consisting of C1 and C2 had a good predictability for responders by receiver-operating characteristic analysis (area under the curve=0.960). Kidneys of the non-responders no longer had diluting ability (%decrease of U-OSM at 4-6 h=2.7±14.6%*), but also barely kept concentrating ability (baseline U-OSM=296.4±68.7* mOsm/L) with markedly reduced estimated glomerular filtration ratio (35.5±29.4 ml · min-1 · 1.73 m-2*) (*P< 0.05 vs. patients who had at least 1 positive condition [n=42]). Conclusions: More than 26% decrease in U-OSM from a baseline > 352 mOsm/L for the first 4-6 h predicts responders to TLV. Unresponsiveness to TLV is attributable to nephrogenic diabetes insipidus complicated by chronic renal disease.
  • Toshiro Inaba, Atsushi Yao, Tomoko Nakao, Masaru Hatano, Hisataka Maki, Teruhiko Imamura, Taro Shiga, Tadashi Yamazaki, Makoto Sonoda, Koichiro Kinugawa, Takahiro Shiota, Junichi Suzuki, Katsu Takenaka, Yasunobu Hirata, Ryozo Nagai
    Circulation journal : official journal of the Japanese Circulation Society 77 1 198 - 206 2013年 [査読有り][通常論文]
     
    BACKGROUND: Non-invasive assessment of volume and function on the right ventricle (RV) for pulmonary hypertension (PH) is limited. METHODS AND RESULTS: Patients with PH (n=23) underwent 3-dimensional (D) echocardiography (3DECHO), with cardiac magnetic resonance imaging to confirm its precision, and right heart catheterization. On linear regression analysis the RV end-systolic volume index (ESVI) was positively correlated with pulmonary vascular resistance (PVR) and mean pulmonary arterial pressure (mPAP; R=0.42 and 0.46, P=0.03 and 0.03, respectively). The RV end-diastolic volume index (EDVI) was positively correlated with mPAP (R=0.41, P<0.05). The left ventricular (LV) EDVI was inversely correlated with PVR (R=-0.48, P=0.02). The RV ejection fraction was inversely correlated with PVR and mean right atrial pressure (mRAP; R=-0.57, and -0.45, P=0.004, and 0.03, respectively). RVEDVI/LVEDVI and RVESVI/LVESVI (the diastolic and systolic remodeling indices, respectively) had a significantly positive linear relationship with PVR (R=0.67 and 0.55, P=0.0005 and 0.006, respectively), and the former had a significantly positive linear relationship with mRAP (R=0.42, P<0.05). During the recovery process in 1 specific case, the remodeling indices maintained a significant linear relationship with the hemodynamic parameters. CONCLUSIONS: Novel indices provided by 3DECHO may be utilized as alternative indicators of hemodynamic changes in PH patients.
  • Naoko Kato, Koichiro Kinugawa, Etsuko Nakayama, Takako Tsuji, Yumiko Kumagai, Teruhiko Imamura, Hisataka Maki, Taro Shiga, Masaru Hatano, Atsushi Yao, Chikako Miura, Issei Komuro, Ryozo Nagai
    International heart journal 54 6 382 - 9 2013年 [査読有り][通常論文]
     
    Self-care is a cornerstone for the successful management of heart failure (HF). The purpose of this study was to examine the impacts of HF self-care on prognosis in Japanese patients with HF. A total of 283 HF outpatients (age 64 ± 14, 70% male, 52% HFrEF) were enrolled. We asked patients to answer about their adhevence to 5 self-care behaviors (medication, eating a low-sodium diet, regular exercise, daily weight check, and treatment seeking behavior). On the basis of the results, we classified patients into a good self-care group and a poor self-care group. The primary outcome was HF hospitalization and/or cardiac death. In total, 65% of patients were classified into the poor self-care group. During a median follow-up of 2 years, cardiac events occurred more frequently in the poor self-care group (22% versus 9.6%, P = 0.013). Poor self-care was an independent risk factor for cardiac events in Cox regression analysis adjusted for clinical parameters (hazard ratio = 2.86, P = 0.005). Poor self-care was also associated with an increased number of HF hospitalizations as well as an extended length of hospital stay for HF. Poor knowledge about HF was an independent determinant for poor self-care in multivariate logistic regression analysis (odds ratio = 0.92, P = 0.019). Insufficient self-care is an independent risk factor for cardiac events in Japanese patients with HF.
  • Tatsuya Asanuma, Yasutomi Higashikuni, Hiroshi Yamashita, Ryozo Nagai, Toshiaki Hisada, Seiryo Sugiura
    International heart journal 54 1 54 - 8 2013年 [査読有り][通常論文]
     
    Simulation studies have been performed in attempts to elucidate the signifi cance of shear and tissue stresses in the progression and rupture of coronary artery plaques, but few studies have analyzed both stresses simultaneously. We analyzed the distributions of shear stress and tissue stress in a model of coronary artery plaque based on intravascular ultrasound data by fluid-structure interaction finite element analysis under physiological pressure and flow. As shown in previous studies, the region of peak shear stress was observed at the proximal side of the plaque where flow velocity was high but its value was at most 10 Pa. On the other hand, 1000-10,000 times greater tissue stress was located in the stenotic region but the location of peak tissue stress was different from that of shear stress. We also found that stenting not only stabilizes the stented segment but also reduces the stress in the adjacent region. Fluid-structure interaction analysis revealed discordance in the distribution of shear and tissue stresses. These two stresses exert distinct influences on the coronary plaque, rupture of which may occur where tissue stress exceeds the plaque strength, which is weakened by pathological processes triggered by shear stress.
  • Toru Suzuki, Eduardo Bossone, Daigo Sawaki, Rolf Alexander Jánosi, Raimund Erbel, Kim Eagle, Ryozo Nagai
    American heart journal 165 1 15 - 25 2013年01月 [査読有り][通常論文]
     
    The development of diagnostic biomarkers of acute cardiovascular disease remains an important topic of interest given potential use to aid in early diagnosis. Cardiac biomarkers of ischemia and heart failure have already proven to be clinically useful. Biomarkers of aortic diseases are also needed, especially for life-threatening conditions such as aortic dissection. In this review, we discuss the present status of the development of biomarkers of aortic diseases. Although aortic dissection has been most vigorously pursued, there has also been notable recent progress in biomarkers of aneurysms and inflammatory aortic disease.
  • Naomi Ogawa, Yasushi Imai, Hiroshi Nishimura, Masayoshi Kato, Norifumi Takeda, Kan Nawata, Tsuyoshi Taketani, Tetsuro Morota, Shinichi Takamoto, Ryozo Nagai, Yasunobu Hirata
    International heart journal 54 1 23 - 6 2013年 [査読有り][通常論文]
     
    Marfan syndrome (MFS) is an inherited connective tissue disorder mainly caused by the fibrillin-1 mutation. Deficient fibrillin-1 is thought to result in the failed sequestration of transforming growth factor β (TGFβ) and subsequent activation of the TGFβ signaling pathway, suggesting that the circulating TGFβ level may be elevated in MFS, although its accurate measurement is complex due to ex vivo release from platelet stores upon platelet activation. We measured the plasma TGFβ1 levels of 32 Japanese MFS patients (22 medically untreated, 10 treated, 20 males, 30.1 ± 9.6 years old) and 30 healthy volunteers (19 males, 29.5 ± 5.8 years old) by ruthenium-based electrochemiluminescence platform (ECL). PF4 was also measured by enzyme immunoassay (EIA) as a platelet degranulation marker. There was no significant difference in the mean plasma TGFβ1 level between the MFS group (1.31 ± 0.40 ng/mL) and controls (1.17 ± 0.33 ng/mL) (P = 0.16, NS). Also, there was no significant difference between the untreated (1.24 ± 0.37 ng/mL) and treated (1.46 ± 0.45 ng/mL) MFS patients (P = 0.15, NS). We also measured PF4, which showed wide deviations but no significant difference between the two groups (P = 0.50). A difference in circulating TGFβ1 levels between MFS patients and controls was not detected in this Japanese population. Circulating TGFβ1 is not a diagnostic and therapeutic marker for Japanese MFS patients, although our findings do not eliminate the possible association of TGFβ with the pathogenesis of MFS.
  • Aiko Sakamoto, Yuko Ishizaka, Minoru Yamakado, Kazuhiko Koike, Ryozo Nagai, Nobukazu Ishizaka
    JOURNAL OF ATHEROSCLEROSIS AND THROMBOSIS 20 2 142 - 151 2013年 [査読有り][通常論文]
     
    Aim: Serum gamma-glutamyltransferase (GGT) levels, which are associated with insulin resistance, may predict the incidence of cardiovascular disease and mortality. Here, the relationship was analyzed between changes in obesity parameters and those in serum GGT over a one-year period. Methods: Data were analyzed from individuals who underwent general health screening two years running. Results: Among 3086 individuals (1954 men, 1132 women), percent changes in both waist circumference (%dWC) and body mass index (BMI) (%dBMI) were significantly correlated with percent changes in GGT (%dGGT) in men (r = 0.17 and r = 0.31, respectively). On the other hand, in women, %dBMI, but not %dWC, had a significant association with %dGGT. When age, %dWC, %dBMI, smoking status, and alcohol intake were all included as independent variables, %dBMI, but not %dWC, showed a graded association with the highest %dGGT quartile in both genders. Furthermore, incorporation of %dWC as an additional independent variable to age, gender, and %dBMI did not show an incremental improvement in prediction for the highest %dGGT quartile (C statistic, 0.643 to 0.648; p = 0.380), suggesting that taking WC changes into account does not significantly improve the prediction of GGT changes when BMI has already been taken into consideration. Conclusion: Changes in BMI are dose-dependently associated with GGT changes in both genders; however, the additional consideration of changes in WC does not show a significant statistical improvement in the prediction of GGT changes.
  • Teruhiko Imamura, Koichiro Kinugawa, Taro Shiga, Miyoko Endo, Naoko Kato, Toshiro Inaba, Hisataka Maki, Masaru Hatano, Atsushi Yao, Takashi Nishimura, Yasunobu Hirata, Shunei Kyo, Minoru Ono, Ryozo Nagai
    Circulation journal : official journal of the Japanese Circulation Society 77 1 96 - 104 2013年 [査読有り][通常論文]
     
    BACKGROUND: It is often difficult to predict reversibility of liver or renal function after left ventricular assist device (LVAD) implantation in patients with stage D heart failure. METHODS AND RESULTS: Data were obtained for 69 patients who had received a LVAD (18 continuous-flow, 51 pulsatile). Persistent hepatic or renal dysfunction was defined as levels of total bilirubin (TB) or creatinine (Cre) >1.5mg/dl at 6 months after LVAD implantation. TB score or Cre score was calculated: 0.15 × age+1.1 × (preoperative TB) or 0.2 × age+3.6 × (preoperative Cre), in which coefficients were determined on the basis of odds ratios for persistent hepatic or renal dysfunction, respectively. Receiver-operating characteristics analyses showed good predictabilities for persistent end-organ dysfunction (area under curve: 0.794 for TB score and 0.839 for Cre score). High-risk strata of TB score (>11.0 points) or Cre score (>14.1 points) were associated with persistently higher levels of TB or Cre (TB, 1.32 ± 0.51; Cre, 1.23 ± 0.41 mg/dl; both P<0.001 vs. low-risk strata). CONCLUSIONS: Reversibility of end-organ function with LVAD implantation can be well predicted by our new risk scoring system that consists of the preoperative TB or Cre level adjusted by the patient's age. The scoring system would be beneficial, especially in considering the indication of a bridge to candidacy.
  • Atsuko Nakayama, Masao Takahashi, Kazuyoshi Hina, Katsuhito Fujiu, Hiroaki Sugiyama, Toshiya Kojima, Jiro Ando, Yasushi Imai, Yasunobu Hirata, Ryozo Nagai
    International heart journal 54 2 111 - 4 2013年 [査読有り][通常論文]
     
    Although hypertrophic cardiomyopathy (HCM) with an accessory pathway is encountered in clinical practice, there is little evidence of a coherent strategy for ablation of the accessory pathway in patients with HCM. We present the case of a 61-year-old man who had type B Wolff-Parkinson-White (WPW) syndrome with hypertrophic obstructive cardiomyopathy (HOCM). Due to paroxysmal atrial fibrillation, he underwent radiofrequency catheter ablation of the accessory pathway located in the right postero-lateral wall to prevent secondary symptomatic events. His LV dyssynchrony improved after the procedure, but the degree of the LV outflow tract (LVOT) pressure gradient was increased. To stabilize the LVOT pressure gradient, he needed additional medications. This case shows that patients with HOCM should be carefully evaluated before making a decision concerning ablation of the accessory pathway.
  • Ryozo Nagai, Koichiro Kinugawa, Hiroshi Inoue, Hirotsugu Atarashi, Yoshihiko Seino, Takeshi Yamashita, Wataru Shimizu, Takeshi Aiba, Masafumi Kitakaze, Atsuhiro Sakamoto, Takanori Ikeda, Yasushi Imai, Takashi Daimon, Katsuhiro Fujino, Tetsuji Nagano, Tatsuaki Okamura, Masatsugu Hori
    Circulation Journal 77 4 908 - 916 2013年 [査読有り][通常論文]
     
    Background: A rapid heart rate (HR) during atrial fibrillation (AF) and atrial flutter (AFL) in left ventricular (LV) dysfunction often impairs cardiac performance. The J-Land study was conducted to compare the efficacy and safety of landiolol, an ultra-short-acting β-blocker, with those of digoxin for swift control of tachycardia in AF/AFL in patients with LV dysfunction. Methods and Results: The 200 patients with AF/AFL, HR ≥120 beats/min, and LV ejection fraction 25-50% were randomized to receive either landiolol (n=93) or digoxin (n=107). Successful HR control was defined as ≥20% reduction in HR together with HR <110 beats/min at 2 h after starting intravenous administration of landiolol or digoxin. The dose of landiolol was adjusted in the range of 1-10 μg · kg-1 · min-1 according to the patient's condition. The mean HR at baseline was 138.2±15.7 and 138.0±15.0 beats/min in the landiolol and digoxin groups, respectively. Successful HR control was achieved in 48.0% of patients treated with landiolol and in 13.9% of patients treated with digoxin (P<0.0001). Serious adverse events were reported in 2 and 3 patients in each group, respectively. Conclusions: Landiolol was more effective for controlling rapid HR than digoxin in AF/AFL patients with LV dysfunction, and could be considered as a therapeutic option in this clinical setting.
  • Yoshihiko Izumida, Naoya Yahagi, Yoshinori Takeuchi, Makiko Nishi, Akito Shikama, Ayako Takarada, Yukari Masuda, Midori Kubota, Takashi Matsuzaka, Yoshimi Nakagawa, Yoko Iizuka, Keiji Itaka, Kazunori Kataoka, Seiji Shioda, Akira Niijima, Tetsuya Yamada, Hideki Katagiri, Ryozo Nagai, Nobuhiro Yamada, Takashi Kadowaki, Hitoshi Shimano
    Nature communications 4 2316 - 2316 2013年 [査読有り][通常論文]
     
    During fasting, animals maintain their energy balance by shifting their energy source from carbohydrates to triglycerides. However, the trigger for this switch has not yet been entirely elucidated. Here we show that a selective hepatic vagotomy slows the speed of fat consumption by attenuating sympathetic nerve-mediated lipolysis in adipose tissue. Hepatic glycogen pre-loading by the adenoviral overexpression of glycogen synthase or the transcription factor TFE3 abolished this liver-brain-adipose axis activation. Moreover, the blockade of glycogenolysis [corrected] through the knockdown of the glycogen phosphorylase gene and the resulting elevation in the glycogen content abolished the lipolytic signal from the liver, indicating that glycogen is the key to triggering this neurocircuitry. These results demonstrate that liver glycogen shortage activates a liver-brain-adipose neural axis that has an important role in switching the fuel source from glycogen to triglycerides under prolonged fasting conditions.
  • Shogo Watanabe, Eisuke Amiya, Masafumi Watanabe, Munenori Takata, Atsuko Ozeki, Aya Watanabe, Shuichi Kawarasaki, Tomoko Nakao, Yumiko Hosoya, Kazuko Omori, Koji Maemura, Issei Komuro, Ryozo Nagai
    Circulation Journal 77 4 1018 - 1025 2013年 [査読有り][通常論文]
     
    Background: Endothelial dysfunction and autonomic nervous system imbalance are both risk markers of atherosclerotic vascular damage. The relationship between these 2 factors, however, has not been clarified concisely. Methods and Results: Flow-mediated dilation (FMD) was measured in 47 patients with ischemic heart disease (IHD mean age, 68.1±7.1 years) using an ultrasound semi-automatic measuring system (UNEXEF18G), and autonomic nervous system activity was evaluated by simultaneous measurements of heart rate variability. FMD was significantly correlated with standard deviation of normal-to-normal beats (r=0.33, P=0.022) and the power ratio of low-frequency power to high-frequency power (LF/HF r=-0.38, P=0.0087). Furthermore, multiple regression analysis indicated that LF/HF was the most important predictor of the magnitude of FMD. This interaction was severely blunted by β-blockers and the presence of diabetes. Moreover, standardized FMD according to autonomic nervous system activity was a better predictor of future cardiovascular events than FMD. Subjects with cardiovascular events had a significantly smaller corrected FMD (event (+), 3.62±0.41 event (-), 5.10±2.35 P=0.001), and the higher corrected FMD was associated with longer event-free survival. Conclusions: Autonomic nervous system activity is an important regulatory factor of FMD in subjects with IHD. Assessment of this interaction can help provide more accurate risk stratification of subjects with IHD.
  • Eisuke Amiya, Masafumi Watanabe, Munenori Takata, Shogo Watanabe, Atsuko Ozeki, Aya Watanabe, Shuichi Kawarasaki, Tomoko Nakao, Yumiko Hosoya, Kazuko Omori, Koji Maemura, Yasunobu Hirata, Ryozo Nagai, Issei Komuro
    Circulation journal : official journal of the Japanese Circulation Society 77 7 1844 - 53 2013年 [査読有り][通常論文]
     
    BACKGROUND: Differences in regulating factors and the clinical implications of body temperature variability (BTV) between subjects with and without diabetes have not been clarified to date. METHODS AND RESULTS: In 66 subjects with ischemic heart disease (33 with diabetes and 33 without diabetes), BTV, the difference between the highest and lowest temperature measurements, and body temperature standard deviation (BT SD) were measured from axillary body temperature (ABT) records of 3 consecutive days and followed for 16.4±8.4 months. In subjects without diabetes BTV and BT SD were closely associated with endothelial function as evaluated on flow-mediated dilation (BTV, R=0.33, P=0.026; BT SD, R=0.41, P=0.029), whereas there was a poor association in subjects with diabetes. In the absence of an interrelationship between vascular function and thermoregulation, the contribution of inflammation to BTV was increased in subjects with diabetes (BTV, 0.59±0.21°C for C-reactive protein [CRP] <0.08 mg/dl vs. 0.79±0.28°C for CRP >0.08 mg/dl, P=0.014). Event-free survival analysis showed that in subjects with diabetes higher BT SD was associated with shorter event-free survival (log-rank P=0.012), but this relationship was not found in subjects without diabetes. CONCLUSIONS: In subjects with diabetes, the interrelationship between thermoregulation and vascular function was disrupted and the effect of inflammation on thermoregulation was enhanced, so that BTV had a sufficient predictive value for cardiovascular events in diabetic subjects.
  • Takahide Kohro, Tsutomu Yamazaki, Hiroki Sato, Kenji Harada, Kazuhiko Ohe, Issei Komuro, Ryozo Nagai
    International Heart Journal 54 2 93 - 97 2013年 [査読有り][通常論文]
     
    There have been few reports concerning the trends in antidiabetic drug use in Japan. In 2009, a dipeptidyl peptidase- 4 inhibitor (DPP4I), an antidiabetic with a new mechanism of action, was made available. This study was conducted to analyze the antidiabetic prescription trends in Japan in recent years and the influence of DPP4Is on those trends. We used monthly claims data obtained from a database company. Data from patients 20 years of age or older and who were prescribed antidiabetics were extracted and analyzed. A total of 18,457 patients were prescribed antidiabetics (mean age, 53.6 ± 11.0). The sulfonylurea prescription rate decreased while that of biguanides increased. After the introduction of DPP4Is, use of these agents rapidly increased and the rate further increased one year after DPP4I introduction. DPP4Is also became the most prescribed antidiabetics for those prescribed antidiabetics for the first time. The decrease in the use of sulfonylureas and the increase in the use of biguanides are in accordance with trends observed in the United States and Europe, and probably reflect Japanese physicians' awareness of cumulating evidence gained from studies such as the UK Prospective Diabetes Study (UKPDS). The rapid increase in the DPP4I prescription rate might be the result of several factors including their safety profiles, which were highlighted in clinical studies published just prior to the drugs becoming available. However, there is little data regarding the efficacy of DPP4Is in reducing diabetes related complications, which should be determined in future studies.
  • Tetsu Tanaka, Masahito Ogawa, Jun-ichi Suzuki, Asuka Sekinishi, Akiko Itai, Yasunobu Hirata, Ryozo Nagai, Mitsuaki Isobe
    American journal of physiology. Heart and circulatory physiology 303 12 H1435-45 - H1445 2012年12月 [査読有り][通常論文]
     
    Pressure overload is known to be a cause of cardiac hypertrophy that often transits to heart failure. Although nuclear factor (NF)-κB is a key factor in the progression of cardiac hypertrophy, its pathophysiology is yet to be elucidated. Thus, we aimed to show that inhibition of NF-κB activation improves pressure overload-induced cardiac dysfunction. To assess the effect of inhibition on NF-κB activation in pressure overload cardiac hypertrophy, we used IMD-1041 in a murine thoracic aortic constriction (TAC) model. IMD-1041 inhibits the phosphorylation of IκB via inhibition of IκB kinase-β. IMD-1041 (100 mg·kg(-1)·day(-1)) or vehicle was administered orally into mice once a day, and mice were euthanized on day 42 after TAC. TAC resulted in left ventricular wall thickening, cardiac dysfunction, and increases of heart and lung weight, whereas IMD-1041 significantly suppressed the development of cardiac hypertropy 6 wk after TAC. Histologically, developed cardiac fibrosis and cardiomyocyte hypertrophy occurred in the vehicle-treated group, whereas IMD-1041 significantly attenuated these changes. IMD-1041 suppressed the expression of p65-positive cells and nuclear translocation of p65 induced by TAC compared with vehicle. Matrix metalloproteinase-2 activity increased in the vehicle + TAC-treated group; however, it was suppressed in the IMD-1041 + TAC-treated group. IMD-1041 treatment from day 28 to day 42 after TAC significantly attenuated the decrease in the percentage of fractional shortening and cardiac fibrosis without an antihypertrophic effect. In conclusion, IMD-1041 may be useful for preventing pressure overload-induced cardiac dysfunction and the transition of cardiac hypertrophy to contraction failure via suppression of NF-κB activation.
  • Teruhiko Imamura, Koichiro Kinugawa, Taro Shiga, Naoko Kato, Miyoko Endo, Toshiro Inaba, Hisataka Maki, Masaru Hatano, Atsushi Yao, Yasunobu Hirata, Masaaki Akahane, Takashi Nishimura, Shunei Kyo, Minoru Ono, Ryozo Nagai
    Journal of artificial organs : the official journal of the Japanese Society for Artificial Organs 15 4 395 - 8 2012年12月 [査読有り][通常論文]
     
    For the time being, in Japan, two recently approved implantable ventricular assist devices (VADs) are indicated only when a patient has been listed for heart transplantation or approved to be eligible for heart transplantation by in-hospital committee. The reversibility of end-organ dysfunction must be expected before VAD implantation, but it is often hard to prove during worsening clinical status. We report two patients whose end-organ dysfunction had been eventually demonstrated to be reversible by invasive procedures such as transluminal liver biopsy or transient insertion of intra-aortic balloon pumping.
  • Motoki Inoue, Mariko Takayanagi, Katsuhito Fujiu, Ichiro Manabe, Ryozo Nagai, Tetsushi Taguchi
    Science and technology of advanced materials 13 6 064208 - 064208 2012年12月 [査読有り][通常論文]
     
    Tamibarotene-loaded biodegradable matrices with antithrombogenic and drug-releasing properties were prepared in a crosslinking reaction between amino groups of alkali-treated collagen (AlCol) and active ester groups of trisuccinimidyl citrate. The resulting matrices were characterized by their residual amino group concentrations, swelling ratios and thermal, antithrombogenic and drug-releasing properties. It was clarified that the addition of tamibarotene does not inhibit matrix formation. After immersion in water, the swelling ratio of a matrix became lower than that prior to immersion. Thermal analysis indicated that AlCol interacted with tamibarotene. The addition of tamibarotene to the matrix did not influence the antithrombogenic property of the resulting matrix. A matrix with a high crosslinking density had a prolonged tamibarotene elution time. These results demonstrate that tamibarotene-loaded matrices have great potential as a coating material for drug-eluting stents.
  • Katsuhito Fujiu, Ichiro Manabe, Makoto Sasaki, Motoki Inoue, Hiroshi Iwata, Eriko Hasumi, Issei Komuro, Yasuyuki Katada, Tetsushi Taguchi, Ryozo Nagai
    Science and technology of advanced materials 13 6 064218 - 064218 2012年12月 [査読有り][通常論文]
     
    SUS316L stainless steel and cobalt-chromium and platinum-chromium alloys are widely used platforms for coronary stents. These alloys also contain nickel (Ni), which reportedly induces allergic reactions in some subjects and is known to have various cellular effects. The effects of Ni on neointima formation after stent implantation remain unknown, however. We developed coronary stents made of Ni-free high-nitrogen austenitic stainless steel prepared using a N2-gas pressurized electroslag remelting (P-ESR) process. Neointima formation and inflammatory responses following stent implantation in porcine coronary arteries were then compared between the Ni-free and SUS316L stainless steel stents. We found significantly less neointima formation and inflammation in arteries implanted with Ni-free stents, as compared to SUS316L stents. Notably, Ni2+ was eluted into the medium from SUS316L but not from Ni-free stainless steel. Mechanistically, Ni2+ increased levels of hypoxia inducible factor protein-1α (HIF-1α) and its target genes in cultured smooth muscle cells. HIF-1α and their target gene levels were also increased in the vascular wall at SUS316L stent sites but not at Ni-free stent sites. The Ni-free stainless steel coronary stent reduces neointima formation, in part by avoiding activation of inflammatory processes via the Ni-HIF pathway. The Ni-free-stainless steel stent is a promising new coronary stent platform.
  • Masahito Ogawa, Jun-Ichi Suzuki, Kiyoshi Takayama, Takaaki Senbonmatsu, Yasunobu Hirata, Ryozo Nagai, Mitsuaki Isobe
    Laboratory investigation; a journal of technical methods and pathology 92 12 1766 - 76 2012年12月 [査読有り][通常論文]
     
    The complex pathophysiological interactions between heart and kidney diseases are collectively known as cardiorenal syndrome. The renin-angiotensin system (RAS) may have a pivotal role in the development of cardiorenal syndrome. The aim of this study was to elucidate the RAS activity responsible for adverse post-infarction remodeling and prognosis in mice with renal failure. To establish the type IV cardiorenal syndrome model, 5/6 nephrectomy (NTX) was performed in a surgical procedure, followed by the induction of myocardial ischemia (MI) by a coronary artery ligation 4 weeks later. NTX and MI resulted in deteriorated left ventricular remodeling and RAS activation, which was improved by an aliskiren that appeared to be independent of renal function and blood pressure (BP). Moreover, MI induced in renin and angiotensinogen double-transgenic (Tg) mice showed comparable effects to MI plus NTX mice, including advanced ventricular remodeling and enhancement of RAS, oxidative stress, and monocytes chemoattractant protein (MCP)-1. Aliskiren suppressed these changes in the MI-induced Tg mice. In in vitro study, Nox2 expression was elevated by the stimulation of plasma from NTX mice in isolated neonatal cardiomyocytes. However, Nox2 upregulation was negated when we administered plasma from aliskiren-treated-NTX mice or isolated cardiomyocytes from AT1-deficient mice. Primary mononuclear cells also showed an upregulation in the expression of Nox2 and MCP-1 by stimulation with plasma from NTX mice. Our data suggest that renal disorder results in ventricular dysfunction and deteriorates remodeling after MI through excessive RAS activation. Moreover, renin inhibition improved the changes caused by cardiorenal syndrome.
  • Jun-ichi Suzuki, Masahito Ogawa, Keiichi Hishikari, Ryo Watanabe, Kiyoshi Takayama, Yasunobu Hirata, Ryozo Nagai, Mitsuaki Isobe
    Cardiovascular therapeutics 30 6 301 - 7 2012年12月 [査読有り][通常論文]
     
    Macrolide antibiotics are broadly used for the treatment of various microbial infections. However, they are also known to have multiple biologic effects, such as alteration of inflammatory factors and matrix metalloproteinases (MMPs). Because of controversial results in clinical trials, the effects of macrolides on cardiovascular diseases are still to be elucidated. It has been reported that MMP activity is upregulated in various cardiovascular diseases, such as myocarditis, cardiac transplant rejection and myocardial infarction. However, little is known about the effects of macrolides on cardiovascular diseases. We have reported that clarithromycin suppressed the development of myocarditis, cardiac rejection and myocardial ischemia using animal models. In this article, we reviewed the roles of MMPs in cardiovascular diseases and the effects of macrolides on the prevention of adverse tissue remodeling.
  • Taira Fukuda, Miwa Kurano, Haruko Iida, Haruhito Takano, Tomofumi Tanaka, Yumiko Yamamoto, Kenichi Ikeda, Mika Nagasaki, Koshiro Monzen, Kansei Uno, Masayoshi Kato, Taro Shiga, Koji Maemura, Nobuhito Masuda, Hiroshi Yamashita, Yasunobu Hirata, Ryozo Nagai, Toshiaki Nakajima
    European journal of preventive cardiology 19 6 1393 - 400 2012年12月 [査読有り][通常論文]
     
    BACKGROUND: Inflammatory markers such as serum C-reactive protein (CRP), serum amyloid A (SAA), and plasma pentraxin 3 (PTX3), which belong to the pentraxin superfamily, increase due to various inflammatory diseases. Some studies demonstrated that serum CRP and SAA are predictors of cardiovascular diseases, and cardiac rehabilitation (CR) induces anti-inflammatory effects. In the present study, we investigated the effects of CR on pentraxins (serum CRP, SAA, and plasma PTX3) in patients with cardiovascular diseases. METHODS: Fifty patients with cardiovascular diseases [61 ± 13 (mean ± SD) years old, male/female 44/6] participated. Each subject performed CR using aerobic bicycle exercise two or three times per week for 3-6 months. We measured resting serum high-sensitivity CRP (hsCRP), SAA, and plasma PTX3 before and 3 and 6 months after CR, and compared them with VO(2peak) determined using a standard increment cycle ergometer protocol, B-type natriuretic peptide (BNP), and other biochemical data such as HbA1c. RESULTS: There was a significant positive correlation between hsCRP and SAA (r = 0.92, p < 0.001), but no relations between these parameters and PTX3. Plasma PTX3 significantly decreased time dependently during CR (at baseline 3.2 ± 2.0 ng/ml, at 3 months 2.3 ± 0.8 ng/ml, at 6 months 2.1 ± 0.7 ng/ml; all p < 0.05). Serum hsCRP tended to decrease, but not statistically significantly. At baseline, plasma PTX3 was negatively correlated with the percentage of the predicted values of VO(2peak) and positively correlated with BNP. CR significantly increased the percentage of the predicted values of VO(2peak) and decreased BNP. CONCLUSIONS: Plasma PTX3, an inflammatory marker, which was quite different from CRP and SAA, decreased during cardiac rehabilitation with an improvement of exercise capacity in patients with cardiovascular diseases.
  • The Relation between the Blood Pressure Estimated by Pulse Wave Velocity and the Directly Measured Arterial Pressure in Humans
    Tsukasa Inajima, Yasushi Imai, Hiroyuki Morita, Ryozo Nagai, Katsuya Iijima, Shintaro Yanagimoto, Naoki Yahagi, Guillaume Lopez, Masaki Shuzo, Ichiro Yamada
    Journal of Robotics and Mechatronics, Special Issue on “Medical Science and Engineering Cooperation” 24 5 1 - 9 2012年12月 [査読有り][通常論文]
  • Guoqin Wang, Masafumi Watanabe, Yasushi Imai, Kazuo Hara, Ichiro Manabe, Koji Maemura, Momoko Horikoshi, Atsuko Ozeki, Chikako Itoh, Takao Sugiyama, Takashi Kadowaki, Tsutomu Yamazaki, Ryozo Nagai
    Journal of human genetics 57 11 727 - 33 2012年11月 [査読有り][通常論文]
     
    Modulator recognition factor-2 (Mrf2/AT-rich interaction domain (Arid)5b) has been revealed to be involved in pathogenesis of atherosclerosis and adipogenesis. Single-nucleotide polymorphisms (SNPs) in the MRF2/ARID5B gene are associated with coronary artery disease (CAD) and has been proposed as a candidate gene for type 2 diabetes (T2D). The study was aimed to determine whether any of the four MRF2/ARID5B SNPs (rs2893880, rs10740055, rs7087507 and rs10761600) associated with susceptibility to CAD are also associated with T2D, and to determine whether SNP genotype influences the levels of adiponectin and other clinical factors. Association of MRF2/ARID5B SNPs was investigated in 500 diabetic patients from the Department of Metabolic Diseases at the University of Tokyo and 243 hospital-based nondiabetic individuals from the Institute for Adult Disease Asahi Life Foundation Hospital and 500 community-based nondiabetic individuals from the Hiroshima Atomic Bomb Casualty Council Health Management Center. Associations of haplotypes of these SNP with levels of adiponectin and other clinical factors were evaluated when the data was available. We found rs2893880C, rs10740055A, rs7087507A and rs10761600T were increasingly associated with T2D in terms of allele/genotype frequencies of each SNP and their haplotype combinations. Individuals with haplotype CAAT indicated an 1.86 times higher prevalence of diabetes compared with individuals with GCGA (OR 1.86 (95% confidence interval (CI) 1.43-2.41)). Furthermore, CAAT significantly associated with adiponectin levels and other clinical factors. In conclusion, polymorphisms on the MRF2/ARID5B gene were associated with susceptibility to T2D as well as adiponectin and other clinical factors, which was in a completely concordant way with their associations with CAD.
  • Minami Yoshiyasu, Sahara Makoto, Nakajima Toshiaki, Ikutomi Masayasu, Morita Toshihiro, Yamashita Hiroshi, Hirata Yasunobu, Nagai Ryozo, Sata Masataka
    CIRCULATION 126 21 2012年11月 [査読有り][通常論文]
  • Higashikuni Yasutomi, Nagai Ryozo, Sata Masataka
    CIRCULATION 126 21 2012年11月 [査読有り][通常論文]
  • Tomoko Nakao, Hiroyuki Watanabe, Norihiko Takeda, Shuichiro Takanashi, Ryozo Nagai
    EUROPEAN HEART JOURNAL-CARDIOVASCULAR IMAGING 13 11 966 - 966 2012年11月 [査読有り][通常論文]
  • 大川 庭煕, 森 啓純, 沼田 玄理, 加藤 愛巳, 森岡 まさき, 加藤 賢, 山田 友春, 川上 拓也, 今村 輝彦, 安部 元, 多田 祐子, 田中 悌史, 荷見 映理子, 清末 有宏, 内野 悠一, 細谷 弓子, 高橋 政夫, 岩田 洋, 安東 治郎, 藤田 英雄, 山下 尋史, 平田 恭信, 永井 良三
    ICUとCCU 36 10 807 - 807 医学図書出版(株) 2012年10月
  • Teruhiko Imamura, Koichiro Kinugawa, Taro Shiga, Miyoko Endo, Naoko Kato, Toshiro Inaba, Hisataka Maki, Masaru Hatano, Atsushi Yao, Takashi Nishimura, Yasunobu Hirata, Shunei Kyo, Minoru Ono, Ryozo Nagai
    Journal of cardiology 60 4 295 - 300 2012年10月 [査読有り][通常論文]
     
    BACKGROUND: Several groups have reported that an elevated ratio of early (E) to late (A) diastolic filling velocities is observed in patients after heart transplantation. However, the mechanism has not been fully analyzed. METHODS: Serial echocardiography and hemodynamic study were performed in 16 patients who had received heart transplantation and had no evidence of rejection during 1 month after the operation. RESULTS: On Day 1 after the surgery, E/A ratio was higher and peak velocity of A wave was lower than normal range among the patients after heart transplantation. E/A ratio and peak velocity of A wave gradually normalized during 1 moth after the surgery. Meanwhile, early mitral annular velocity and pulmonary capillary wedge pressure remained within normal range during the study period. CONCLUSIONS: Longer ischemic time during heart transplantation procedure may cause atrial stunning, but it appears to recover within 1 month. We have to be alert to misinterpretation of this "psuedo-psuedonormal" mitral inflow pattern early after transplantation.
  • Hajime Abe, Morimasa Takayama, Norihiko Takeda, Syuichiro Takanashi, Ryozo Nagai
    EUROPEAN HEART JOURNAL-CARDIOVASCULAR IMAGING 13 10 826 - 826 2012年10月 [査読有り][通常論文]
  • Kentaro Yuda, Hidenori Takahashi, Tatsuya Inoue, Takashi Ueta, Aya Iriyama, Kazuaki Kadonosono, Yasuhiro Tamaki, Hiroyuki Aburatani, Ryozo Nagai, Yasuo Yanagi
    AMERICAN JOURNAL OF PATHOLOGY 181 4 1464 - 1472 2012年10月 [査読有り][通常論文]
     
    The molecular mechanism that leads to age-related macular degeneration (AMD) is poorly understood. Gene expression profiling identified adrenomedullin (ADM) as a possible molecular target for the treatment of AMD and expression of ADM was upregulated in eyes with laser-induced choroidal neovascularization (CNV). In vivo experiments strongly indicated that ADM inhibits laser-induced CNV. In vitro tube formation assay demonstrated that neither ADM nor conditioned medium from the retinal pigment epithelial (RPE) cells, D407 cells, treated with ADM affected the capillary-formation of human umbilical vein endothelial cells. In contrast, in vitro macrophage migration assay clearly demonstrated that the conditioned medium of D407 inhibited macrophage migration. Furthermore, the expression of C-C motif chemokine 2 (CCL2) was significantly inhibited in D407 cells after ADM treatment. In vivo experiments using a laser-induced CNV model in ADM(+/-) mice demonstrated that CCL2 expression was upregulated in ADM(+/-) mice with concomitant increase in macrophage migration in the subretinal space. Additionally, the effect of ADM was abrogated in CCL2 knockout mice. These results suggest that administration of ADM inhibits macrophage migration in the subretinal space and leads to the suppression of laser-induced CNV in an animal model. The inhibition of macrophage migration occurred through the CCL2 from RPE. This study provides a novel potential therapeutic target for AMD which does not substantially disrupt VEGF-A signaling mediated vasculogenesis. (Am J Pathol 2012, 181:14641472 http://dx.dot.org/10.1016/j.ajpath.2012.06.028)
  • Higashikuni Yasutomi, Nagai Ryozo, Sata Masataka
    JOURNAL OF CARDIAC FAILURE 18 10 S146  2012年10月 [査読有り][通常論文]
  • Teruhiko Imamura, Koichiro Kinugawa, Taro Shiga, Miyoko Endo, Toshiro Inaba, Hisataka Maki, Masaru Hatano, Yasushi Imai, Atsushi Yao, Yasunobu Hirata, Takashi Nishimura, Shunei Kyo, Minoru Ono, Ryozo Nagai
    Journal of artificial organs : the official journal of the Japanese Society for Artificial Organs 15 3 301 - 4 2012年09月 [査読有り][通常論文]
     
    Refractory ventricular tachyarrhythmias are life threatening, especially in patients with stage D heart failure, and left ventricular assist device therapy is virtually the sole option to resolve the fatal conditions in many cases. The Interagency Registry for Mechanically Assisted Circulatory Support defines modifier A as complicating recurrent ventricular tachyarrhythmias. However, the optimal timing to implant a left ventricular assist device remains to be determined in less sick patients with modifier A. We experienced three patients with stage D heart failure with revised modifier A, i.e., at least two appropriate operations of implantable cardiac defibrillators within 2 weeks. Two of them were rescued by extracorporeal left ventricular assist device implantation, but one died because of an electrical storm before left ventricular assist device support was available. We would like to emphasize that we should consider implantable left ventricular assist device therapy as soon as possible for those who are assigned modifier A to prevent sudden arrhythmic death.
  • 都市部在住者の血中脂肪酸濃度および脂肪酸バランスと冠動脈疾患および急性冠症候群との関連 多施設共同横断研究の結果から
    西崎 祐史, 島田 和典, 谷 樹昌, 小川 崇之, 安東 治郎, 高橋 政夫, 山本 雅人, 宮内 克己, 長尾 建, 平山 篤志, 吉村 道博, 永井 良三, 代田 浩之
    日本心臓病学会誌 7 Suppl.I 273 - 273 (一社)日本心臓病学会 2012年08月
  • Takehiro Takahashi, Yoshihide Asano, Eisuke Amiya, Masaru Hatano, Zenshiro Tamaki, Atsuko Ozeki, Aya Watanabe, Shuichi Kawarasaki, Tomoko Nakao, Takashi Taniguchi, Yohei Ichimura, Tetsuo Toyama, Masafumi Watanabe, Yasunobu Hirata, Ryozo Nagai, Shinichi Sato
    Modern rheumatology 22 4 598 - 601 2012年08月 [査読有り][通常論文]
     
    Intravenous cyclophosphamide pulse therapy (IVCY) exerts its efficacy against interstitial lung disease (ILD) associated with systemic sclerosis (SSc) by restoring vascular injuries as well as aberrant immune activation. We recently experienced two patients with SSc-ILD in whom the values of brachial flow-mediated dilation (FMD) reflected the efficacy of IVCY. We herein report the details of these cases and discuss the potential of FMD to predict and evaluate the effect of IVCY on SSc-ILD.
  • Ayako Nagashima, Ryo Watanabe, Masahito Ogawa, Jun-Ichi Suzuki, Mayumi Masumura, Keiichi Hishikari, Tomoko Shimizu, Kiyoshi Takayama, Yasunobu Hirata, Ryozo Nagai, Mitsuaki Isobe
    Journal of cardiovascular pharmacology 60 2 158 - 64 2012年08月 [査読有り][通常論文]
     
    BACKGROUND: Telmisartan is an angiotensin II receptor blocker, which acts as a partial agonist of peroxisome proliferator activator receptor-γ (PPAR-γ). Because PPAR-γ initiates a variety of antiinflammatory responses, the effect on myocardial ischemia is to be elucidated. METHODS AND RESULTS: The left anterior descending arteries were ligated to induce myocardial infarction in rats. The animals were assigned to 4 groups: (1) control (saline, n = 6), (2) telmisartan (10 mg·kg·d, n = 6), (3) telmisartan + GW9662 (PPAR-γ-antagonist) (10 mg·kg·d of telmisartan and 1 mg·kg·d of GW9662, n = 6), and (4) amlodipine (10 mg·kg·d, n = 8) groups. Telmisartan reduced mean blood pressure compared with that in the control group. There was no statistical difference among the telmisartan, telmisartan + GW9662 and amlodipine groups. The end-diastolic left ventricular diameter was smaller in telmisartan group compared with that in the control group; GW9662 negated the effect of telmisartan. The thickness of the ventricular septum was kept in the telmisartan group compared with that in the control group; GW9662 negated the effect. Histopathologic analyses showed that telmisartan suppressed myocardial fibrosis compared with that of the control, whereas GW9662 negated the telmisartan effect. CONCLUSIONS: Telmisartan suppresses pathological remodeling by PPAR-γ agonistic activities independent of its antihypertensive effects.
  • Hiroaki Semba, Hitoshi Sawada, Tokuhisa Uejima, Norihiko Takeda, Katsura Soma, Hajime Abe, Takeshi Yamashita, Ryozo Nagai
    INTERNATIONAL HEART JOURNAL 53 4 230 - 233 2012年07月 [査読有り][通常論文]
     
    Left ventricular outflow tract obstruction (LVOTO) is commonly observed in patients with hypertrophic cardiomyopathy (HCM) or left ventricular hypertrophy (LVH). While some patients develop LVOTO at rest, it can also be provoked by physical exertion, and hence termed latent LVOTO (L-LVOTO). Recent reports demonstrated that L-LVOTO develops not only in LVH patients, but also in patients without LVH (non-LVH). However, the prevalence and clinical prognosis of non-LVH patients with L-LVOTO are not yet elucidated. In this study, we retrospectively investigated the echocardiographic features of patients with malignancy who underwent dobutamine stress echocardiography (DSE) to evaluate preoperative cardiac risk. One hundred ninety-nine patients were found not to have LVH or coronary artery disease. Among them, 106 patients exhibited L-LVOTO after DSE. We next compared the baseline echocardiographic features of L-LVOTO (+) patients with those of L-LVOTO (-) patients, and identified the left ventricular outflow tract (LVOT) ratio (systolic LVOT diameter/diastolic LVOT diameter) as a significant predictor of L-LVOTO. An LVOT ratio <= 0.83 was the best cutoff value to detect the presence of L-LVOTO, with a sensitivity of 81.1% and specificity of 80.6%. Overall, L-LVOTO was found to develop in almost half of non-LVH patients with malignancy, in addition, the baseline LVOT ratio was strongly related to the presence of L-LVOTO in non-LVH patients. Therefore, patients with dynamic LVOT narrowing may benefit from DSE to detect the presence of L-LVOTO. (Int Heart J 2012; 53: 230-233)
  • Naoko Kato, Koichiro Kinugawa, Taro Shiga, Masaru Hatano, Norihiko Takeda, Yasushi Imai, Masafumi Watanabe, Atsushi Yao, Yasunobu Hirata, Keiko Kazuma, Ryozo Nagai
    Journal of cardiology 60 1 23 - 30 2012年07月 [査読有り][通常論文]
     
    BACKGROUND: Little is known about depressive symptoms in heart failure with preserved ejection fraction (HFpEF, EF ≥50%). We aimed to assess the prevalence of depression, to clarify the impact of depressive symptoms upon clinical outcomes, and to identify factors associated with these symptoms in HF with reduced EF (HFrEF, EF <50%) and HFpEF. METHODS AND RESULTS: A total of 106 HF outpatients were enrolled. Of them, 61 (58%) had HFpEF. Most patients were male (HFrEF 80%, HFpEF 70%) and the mean of plasma B-type natriuretic peptide (BNP) level in the HFrEF group was similar to that in the HFpEF group (164.8 ± 232.8 vs. 98.7 ± 94.8 pg/mL). HFrEF patients were treated more frequently with beta-blockers compared with HFpEF patients (71% vs. 43%, p=0.004). Depressive symptoms were assessed using the Center for Epidemiologic Studies Depression Scale (CES-D). The prevalence of depression (CES-D score ≥16), and CES-D score did not significantly differ between HFrEF and HFpEF (24% vs. 25%, 14.1 ± 8.3 vs. 12.1 ± 8.3, respectively). During the 2-year follow-up, depressed patients had more cardiac death or HF hospitalization in HFrEF (55% vs. 12%, p=0.002) and HFpEF (35% vs. 11%, p=0.031). Cox proportional hazard analysis revealed that a higher CES-D score, indicating increased depressive symptoms, predicted cardiac events independent of BNP in HFrEF [hazard ratio (HR) 1.07, 95% confidence interval (CI) 1.01-1.13] and HFpEF (HR 1.09, 95% CI 1.04-1.15). Multiple regression analyses adjusted for BNP showed that independent predictors of depressive symptoms were non-usage of beta-blockers and being widowed or divorced in HFrEF. On the other hand, usage of warfarin was the only independent risk factor for depressive symptoms in HFpEF (all, p<0.05). CONCLUSIONS: Depressive symptoms are common and independently predict adverse events in HFrEF/HFpEF patients. This study suggests that beta-blockers reduce depressive symptoms in HFrEF. In contrast, treatment for depression remains to be elucidated in HFpEF.
  • Teruhiko Imamura, Koichiro Kinugawa, Taro Shiga, Miyoko Endo, Toshiro Inaba, Hisataka Maki, Masaru Hatano, Atsushi Yao, Takashi Nishimura, Yasunobu Hirata, Shunei Kyo, Minoru Ono, Ryozo Nagai
    Journal of artificial organs : the official journal of the Japanese Society for Artificial Organs 15 2 200 - 3 2012年06月 [査読有り][通常論文]
     
    Postoperative right ventricular failure is usually apparent perioperatively or soon after left ventricular assist device insertion. Here, we report a case complicated by right ventricular failure that manifested 3 weeks after HeartMate II implantation. This case is also unique because the postoperative right ventricular failure was progressive over the years. We discuss how the smaller size of the left ventricle and untreated tricuspid regurgitation contributed to the development of right ventricular failure in this case.
  • Aiko Sakamoto, Makiko Hongo, Kan Saito, Ryozo Nagai, Nobukazu Ishizaka
    EUROPEAN JOURNAL OF PHARMACOLOGY 682 1-3 131 - 136 2012年05月 [査読有り][通常論文]
     
    An excess of lipids may accumulate in the kidney in conditions such as diabetes and hypertension, and can potentially cause renal injury. We previously reported that an infusion of angiotensin II into a rat induced deposition of lipids in the renal tubular epithelial cells. Here we have examined the effect of pioglitazone, an agonist of the peroxisome proliferator-activated receptor-gamma (PPAR-gamma), on renal lipid accumulation and renal injury induced by angiotensin II infusion. Pioglitazone treatment (2.5 mg/kg/day) reduced the amount of triglycerides in the kidney of the angiotensin II-induced hypertensive rat without significantly altering either blood pressure levels or mRNA expression of lipogenic genes in the kidney. In addition, pioglitazone, either alone or in conjunction with angiotensin II, increased the expression of phosphorylated, but not total, AMP-activated protein kinase (AMPK). Proteinuria and kidney weight in the angiotensin II-infused rat were significantly decreased by pioglitazone treatment. In addition, pioglitazone suppressed iron deposition and ferritin protein induction, but did not alter upregulated expression of the antioxidative molecule, heme oxygenase-1, in the kidney of the angiotensin II-infused rat. These findings suggested that pioglitazone suppressed the angiotensin II-induced increase in renal lipid content by inhibiting its proteinuric action, but not by direct alteration of the expression or activity of lipid metabolism-related genes. Reduction of lipotoxic renal damage may represent one of the renoprotective effects provided by pioglitazone in hypertension with activation of the renin-angiotensin system. (C) 2012 Elsevier B.V. All rights reserved.
  • Atsuko Nakayama, Hiroyuki Morita, Tetsuro Miyata, Jiro Ando, Hideo Fujita, Hiroshi Ohtsu, Takafumi Akai, Katsuyuki Hoshina, Masatoshi Nagayama, Shuichiro Takanashi, Tetsuya Sumiyoshi, Ryozo Nagai
    ATHEROSCLEROSIS 222 1 278 - 283 2012年05月 [査読有り][通常論文]
     
    Objectives: A strong degree of co-existence between coronary artery disease (CAD) and abdominal aortic aneurysm (AAA) is widely acknowledged, however, it remains to be elucidated whether the existence of CAD is associated with an accelerated expansion rate of AAA. Also, the relationship between preoperative CAD and postoperative major adverse cardiovascular events (MACE) has not been examined in Japanese patients. The aim of this study was to investigate the deleterious effects of CAD on the progression of AAA and the onset of postoperative MACE after elective AAA repair. Methods and results: A retrospective cohort study of 665 consecutive Japanese patients who underwent elective surgical repair for infrarenal AAA at 2 high-volume Tokyo hospitals from 2003 through 2010 was performed. Preoperative CAD was shown to be a significant determinant of postoperative MACE (HR 2.29; 95% CI, 1.12-4.66; p = 0.02). In the analysis of 510 patients for whom there were at least 2 follow-up CT scans of the size of their AAA before repair, the existence of CAD was shown to be inversely associated with the accelerated expansion rate of AAA. Conclusion: This study on the patients undergone elective repair for infrarenal AAA identified an inverse association between the existence of CAD and progression of AAA as well as the significant impact of preoperative CAD on the occurrence of postoperative MACE after elective AAA repair. (C) 2012 Elsevier Ireland Ltd. All rights reserved.
  • Kosei Eguchi, Ichiro Manabe, Yumiko Oishi-Tanaka, Mitsuru Ohsugi, Nozomu Kono, Fusa Ogata, Nobuhiro Yagi, Umeharu Ohto, Masao Kimoto, Kensuke Miyake, Kazuyuki Tobe, Hiroyuki Arai, Takashi Kadowaki, Ryozo Nagai
    Cell metabolism 15 4 518 - 33 2012年04月 [査読有り][通常論文]
     
    Consumption of foods high in saturated fatty acids (FAs) as well as elevated levels of circulating free FAs are known to be associated with T2D. Though previous studies showed inflammation is crucially involved in the development of insulin resistance, how inflammation contributes to β cell dysfunction has remained unclear. We report here the saturated FA palmitate induces β cell dysfunction in vivo by activating inflammatory processes within islets. Through a combination of in vivo and in vitro studies, we show β cells respond to palmitate via the TLR4/MyD88 pathway and produce chemokines that recruit CD11b(+)Ly-6C(+) M1-type proinflammatory monocytes/macrophages to the islets. Depletion of M1-type cells protected mice from palmitate-induced β cell dysfunction. Islet inflammation also plays an essential role in β cell dysfunction in T2D mouse models. Collectively, these results demonstrate a clear mechanistic link between β cell dysfunction and inflammation mediated at least in part via the FFA-TLR4/MyD88 pathway.
  • Teruhiko Imamura, Koichiro Kinugawa, Taro Shiga, Miyoko Endo, Toshiro Inaba, Hisataka Maki, Masaru Hatano, Atsushi Yao, Yasunobu Hirata, Ryozo Nagai
    Journal of cardiology cases 5 2 e113-e117 - e117 2012年04月 [査読有り][通常論文]
     
    Cardiac allograft rejection can be accompanied by diastolic dysfunction, but the hemodynamic change is usually compensated and hard to be recognized noninvasively. Here we report on two transplanted patients who showed electrocardiogram (ECG) changes suggesting right ventricular overload. Hemodynamic measurement revealed increased right ventricular pressure and endomyocardial biopsy confirmed grade 3R rejection. After rejection was treated with steroid pulse, the ECG alterations were reversed and right ventricular pressure was normalized. In such cases, asymptomatic rejection may be diagnosed by ECG changes that are reversible along with the treatment of rejection, although those ECG changes are apparently non-specific.
  • Koichi Kimura, Katsu Takenaka, Aya Ebihara, Tomoko Okano, Kansei Uno, Nobuaki Fukuda, Jiro Ando, Hideo Fujita, Hiroyuki Morita, Yutaka Yatomi, Ryozo Nagai
    ECHOCARDIOGRAPHY-A JOURNAL OF CARDIOVASCULAR ULTRASOUND AND ALLIED TECHNIQUES 29 4 404 - 410 2012年04月 [査読有り][通常論文]
     
    Background: The ratio of early diastolic transmitral flow velocity (E) to tissue Doppler (TD) mitral annular early diastolic velocity (E/E'VEL-TD) has been widely used for the noninvasive assessment of LV diastolic filling pressures. However, it has been reported that E/E'VEL-TD is not accurate particularly when being applied to patients with advanced heart failure. Methods: Fifty-six ICU patients with decompensated heart failure underwent simultaneous echocardiography and PCWP measurements. Patients with elevated PCWP (n = 41) were compared with patients normal PCWP (n = 15) as well as age-matched healthy controls (n = 32). In the apical 4-chamber view, the ratio of E to speckle tracking (ST) mitral annular velocity (E/E'VEL-ST) and early diastolic global LV longitudinal strain rate (E/E'SR-ST) were evaluated as new surrogate markers of elevated PCWP. Results: Correlations with PCWP were observed for speckle tracking derived E/E'VEL-ST (r = 0.40,P = 0.002) and E/E'SR-ST (r = 0.56, P < 0.001), although the traditional E/E'VEL-TD did not show a significant correlation (r = 0.23, P = 0.082). Compared with controls, patients with elevated PCWP had significant increases in all variables. The best cutoff values and diagnostic accuracies for identifying elevated PCWP were E/E'VEL-TD>12 (Sensitivity/Specificity/area under the ROC curve: 0.58/0.90/0.78), E/E'VEL-ST > 14 (0.60/0.85/0.80), and E/E'SR-ST > 93 (0.80/0.88/0.89). Conclusion: Speckle tracking derived E/E'SR-ST may be a robust surrogate marker of elevated LV filling pressure. In ICU patients, E/E'SR-ST showed better correlation with PCWP and higher diagnostic accuracy than the tissue Doppler approach. (Echocardiography 2012;29:404-410)
  • Ryo Watanabe, Masahito Ogawa, Jun-Ichi Suzuki, Yasunobu Hirata, Ryozo Nagai, Mitsuaki Isobe
    Journal of cardiovascular pharmacology 59 4 323 - 30 2012年04月 [査読有り][通常論文]
     
    BACKGROUND: Angiotensin converting enzyme inhibitors have been used clinically to prevent myocardial infarction (MI). The angiotensin converting enzyme inhibitors attenuated ventricular remodeling and improved cardiac function by inhibition of matrix metalloproteinases after MI. Although the effect is thought to be a class effect, there are significant differences among the drugs. The aim of this study was to compare the effects of imidapril and ramipril on ventricular remodeling after MI. METHODS: The middle portion of left anterior descending artery was ligated to induce a moderate size MI in rats (moderate MI group). The proximal portion of the artery was ligated to induce a large size MI (large MI group). The animals were assigned to subgroups in moderate MI group and large MI group: (1) nontreated group, (2) ramipril group (1 mg/kg daily), and (3) imidapril group (1 mg/kg daily). All rats were killed on day 28 after the MI operation. RESULTS: Although the nontreated MI group showed impaired ventricular contraction and severe fibrosis, imidapril significantly negated ischemia-induced changes. Imidapril had a superior effect for preventing ventricular remodeling characterized by fibrosis and collagen accumulation in left ventricle compared with ramipril in the moderate and large MI groups, even though the dosage used in this study was too small to reduce systemic blood pressure. CONCLUSIONS: Imidapril can be used as a substitute for ramipril to prevent ventricular remodeling after MI.
  • Aiko Sakamoto, Nobukazu Ishizaka, Yasushi Imai, Ryozo Nagai
    ATHEROSCLEROSIS 221 2 602 - 603 2012年04月 [査読有り][通常論文]
  • Yoshikazu Hirose, Eiko Saijou, Yasuyoshi Sugano, Fumitaka Takeshita, Satoshi Nishimura, Hidenori Nonaka, Yen-Rong Chen, Keisuke Sekine, Taketomo Kido, Takashi Nakamura, Shigeaki Kato, Toru Kanke, Koji Nakamura, Ryozo Nagai, Takahiro Ochiya, Atsushi Miyajima
    Proceedings of the National Academy of Sciences of the United States of America 109 11 4263 - 4268 2012年03月 [査読有り][通常論文]
     
    Hyaluronic acid (HA) has been implicated in the proliferation and metastasis of tumor cells. However, most previous studies were conducted on extracellular matrix or pericellular HA, and the role of circulating HA in vivo has not been studied. HA is rapidly cleared from the bloodstream. The scavenger receptor Stabilin-2 (Stab2) is considered a major clearance receptor for HA. Here we report a dramatic elevation in circulating HA levels in Stab2- deficient mice without any overt phenotype. Surprisingly, the metastasis of B16F10 melanoma cells to the lungs was markedly suppressed in the Stab2-deficient mice, whereas cell proliferation was not affected. Furthermore, administration of an anti-Stab2 antibody in Stab2+ mice elevated serum HA levels and prevented the metastasis of melanoma to the lung, and also suppressed spontaneous metastasis of mammary tumor and human breast tumor cells inoculated in the mammary gland. Administration of the antibody or high-dose HA in mice blocked the lodging of melanoma cells to the lungs. Furthermore, HA at high concentrations inhibited the rolling/tethering of B16 cells to lung endothelial cells. These results suggest that blocking Stab2 function prevents tumor metastasis by elevating circulating HA levels. Stab2 may be a potential target in antitumor therapy.
  • 無症候性アテローム性動脈硬化患者におけるHelicobacter pylori感染とペプシノゲン値(Helicobacter Pylori Infection and Pepsinogen Level in Patients with Subclinical Atherosclerosis)
    Mizuno Yoshiko, Suzuki Toru, Aizawa Kenichi, Yamazaki Tsutomu, Nagai Ryozo
    Circulation Journal 76 Suppl.I 707 - 707 2012年03月
  • 心筋梗塞および左室機能不全の患者の予後 JCADと日本および欧米の他の主要試験との全国的比較(Prognosis of Patients with Myocardial Infarction and Left Ventricular Dysfunction:Nation-wide Comparison with JCAD and Other Major Japanese and Western Studies)
    Hattori Ai, Kuga Keisuke, Yamasaki Hiro, Watanabe Shigeyuki, Sekiguchi Yukio, Tada Hiroshi, Aonuma Kazutaka, Kohro Takahide, Yamazaki Tsutomu, Nagai Ryozo, Shiga Tsuyoshi, Hagiwara Nobuhisa
    Circulation Journal 76 Suppl.I 1063 - 1063 2012年03月
  • Masahiro Myojo, Hiroshi Iwata, Takahide Kohro, Hiroki Sato, Arihiro Kiyosue, Jiro Ando, Daigo Sawaki, Masao Takahashi, Hideo Fujita, Yasunobu Hirata, Ryozo Nagai
    Atherosclerosis 221 1 148 - 53 2012年03月 [査読有り][通常論文]
     
    BACKGROUND: Macrocytosis, as a qualitative abnormality of erythrocytes, has not drawn attention as a prognostic indicator after PCI, while anemia, as a quantitative abnormality of erythrocytes, has been recognized as a predictor of adverse outcomes. The aim of this study was to perform prognostic risk stratification of patients after PCI based on the presence or absence of macrocytosis. METHODS: The clinical records of 941 consecutive patients who underwent PCI at a single institution were retrospectively reviewed. The prognostic implication of macrocytosis was evaluated by univariate and multivariate Cox's proportional hazard regression analysis. RESULTS: There were 130 (13.8%) patients with macrocytosis. A significantly higher all-cause and cardiac mortality, as well as incidence of composite adverse events were observed in the Macrocytic group. Kaplan-Meier analysis also showed a significantly poorer overall survival in patients with macrocytosis. Even after exclusion of anemic patients, this tendency was still observed. Furthermore, macrocytosis was significantly and independently associated with adverse outcomes after PCI (aHR of cardiac death: 3.45, 95%CI: 1.22-9.80, P=0.019). Interestingly, fewer patients with macrocytosis were prescribed statins compared with those without it (33.8% vs. 47.1%, P=0.005). CONCLUSIONS: The results of the study indicate that measuring mean corpuscular volume (MCV) as a qualitative index of erythrocytes might be helpful for a prognostic risk stratification of patients subjected to PCI.
  • Nobukazu Ishizaka, Aiko Sakamoto, Yasushi Imai, Fumio Terasaki, Ryozo Nagai
    JOURNAL OF CARDIOLOGY 59 2 132 - 138 2012年03月 [査読有り][通常論文]
     
    The cardiovascular system may be involved as a target organ of multifocal fibrosclerosis, which may manifest as idiopathic retroperitoneal fibrosis, inflammatory aortic aneurysm, inflammatory periarteritis, and inflammatory pericarditis. These pathological conditions can sometimes occur concomitantly. Idiopathic retroperitoneal fibrosis and inflammatory abdominal aortic aneurysm are both characterized by the presence of fibro-inflammatory tissue around the abdominal aorta expanding into the surrounding retroperitoneal structures, and together they may be termed 'chronic periaortitis'. Cardiovascular fibrosclerosis has become non-uncommonly encountered condition since imaging modalities have made its diagnosis more feasible. In addition, recent studies have demonstrated that a certain fraction, but not all, of cardiovascular fibrosclerosis may have a link with immunoglobulin-G4 (IgG4)-related sclerosing disease (IgG4-SD). IgG4-SD is histologically characterized by dense fibrosclerosis and infiltration of lymphocytes and IgG4-positive plasma cells, and these histopathologic findings seem to be essentially similar regardless of the organs involved. In this mini review, we summarize what is known so far about multifocal fibrosclerosis of the cardiovascular system and its association with IgG4-SD, and what remains to be clarified in future investigations. (C) 2011 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.
  • Aiko Sakamoto, Nobukazu Ishizaka, Kan Saito, Yasushi Imai, Hiroyuki Morita, Kazuhiko Koike, Takahide Kohro, Ryozo Nagai
    CLINICA CHIMICA ACTA 413 5-6 577 - 581 2012年03月 [査読有り][通常論文]
     
    Background: Immunoglobulin G4 (IgG4)-related immuno-inflammation has been suggested to play a role in the development of remodeling of arterial wall. We investigated the association between serum concentrations of IgG4 or soluble interleukin-2 receptor (sIL-2R) and coronary artery disease (CAD). Methods: Serum concentrations of IgG4 and sIL-2R were measured in 286 patients who underwent coronary angiography. Results: In patients with CAD, the medians of serum concentrations of IgG4 (393 mg/dl) and sIL-2R (388 U/ml) were significantly higher than corresponding values in patients without CAD (IgG4 27.0 mg/dl, sIL-2R 312 U/ml). In receiver-operating characteristic curve analysis, the area under the curve of sIL-2R and IgG4 for the presence of CAD was 0.634 and 0.632, respectively. Age- and gender-adjusted logistic regression analysis showed that both of the fourth quartile of sIL-2R concentrations (>= 509 U/ml) and that of IgG4 concentrations (>= 57.7 mg/dl) were found to be associated with CAD with an odds ratio of 2.82 and 4.08, respectively, compared with the corresponding lowest quartile. Conclusions: Serum concentrations of IgG4 and sIL-2R were increased in patients with angiographically-proven CAD, suggesting that IgG4-related immuno-inflammation may also have a role in the development and/or progression of coronary artery atherosclerosis. (C) 2011 Elsevier B.V. All rights reserved.
  • Aiko Sakamoto, Ryozo Nagai, Kan Saito, Yasushi Imai, Masao Takahashi, Yumiko Hosoya, Norifumi Takeda, Kenji Hirano, Kazuhiko Koike, Yutaka Enomoto, Haruki Kume, Yukio Homma, Daichi Maeda, Hideomi Yamada, Masashi Fukayama, Yasunobu Hirata, Nobukazu Ishizaka
    Journal of cardiology 59 2 139 - 46 2012年03月 [査読有り][通常論文]
     
    Retroperitoneal fibrosis, inflammatory aortic aneurysm, and pericardial and mediastinal fibrosis are characterized by infiltration of immuno-inflammatory cells and deposition of thickened fibrous tissues. Several recent studies suggested that an immunoglobulin-G4 (IgG4)-related immunological mechanism may play a role in these diseases. By searching the clinical database of patients admitted to our department between 2000 and 2010, we summarized the clinical data of 11 patients who were diagnosed to have these disorders. The diagnoses were idiopathic retroperitoneal fibrosis (8 cases), mediastinal and/or pericardial fibrosis (4 cases), inflammatory abdominal aneurysm (2 cases), and inflammatory coronary periarteritis (1 case). Hypertension, diabetes, and dyslipidemia were found in 45%, 36%, and 55%, respectively, in these patients, and they were all either current or former smokers. Two patients with pericardial involvement showed a rushed clinical course, resulting in in-hospital death. Serum levels of IgG were elevated in 67%, and soluble interleukin-2 receptor was elevated in 75%, when measured. Immunohistochemical analysis showed marked infiltration of IgG4-positive plasma cells in the pericardium in patients who died of constrictive pericarditis. Our data support the notion that immune-inflammatory mechanism, which might be IgG4-related sometimes, may play a role in idiopathic retroperitoneal fibrosis, inflammatory aortic aneurysm, and mediastinal/pericardial fibrosis, although clinical course may differ substantially.
  • Yasutomi Higashikuni, Julie Sainz, Kazuto Nakamura, Minoru Takaoka, Soichiro Enomoto, Hiroshi Iwata, Kimie Tanaka, Makoto Sahara, Yasunobu Hirata, Ryozo Nagai, Masataka Sata
    Arteriosclerosis, thrombosis, and vascular biology 32 3 654 - 61 2012年03月 [査読有り][通常論文]
     
    OBJECTIVE: ATP-binding cassette transporter subfamily G member 2 (ABCG2), expressed in microvascular endothelial cells in the heart, has been suggested to regulate several tissue defense mechanisms. This study was performed to elucidate its role in pressure overload-induced cardiac hypertrophy. METHODS AND RESULTS: Pressure overload was induced in 8- to 12-week-old wild-type and Abcg2-/- mice by transverse aortic constriction (TAC). Abcg2-/- mice showed exaggerated cardiac hypertrophy and ventricular remodeling after TAC compared with wild-type mice. In the early phase after TAC, functional impairment in angiogenesis and antioxidant response in myocardium was found in Abcg2-/- mice. In vitro experiments demonstrated that ABCG2 regulates transport of glutathione, an important endogenous antioxidant, from microvascular endothelial cells. Besides, glutathione transported from microvascular endothelial cells in ABCG2-dependent manner ameliorated oxidative stress-induced cardiomyocyte hypertrophy. In vivo, glutathione levels in plasma and the heart were increased in wild-type mice but not in Abcg2-/- mice after TAC. Treatment with the superoxide dismutase mimetic ameliorated cardiac hypertrophy in Abcg2-/- mice after TAC to the same extent as that in wild-type mice, although cardiac dysfunction with impaired angiogenesis was observed in Abcg2-/- mice. CONCLUSION: ABCG2 protects against pressure overload-induced cardiac hypertrophy and heart failure by promoting angiogenesis and antioxidant response.
  • Satoshi Nishimura, Ichiro Manabe, Mika Nagasaki, Shigeru Kakuta, Yoichiro Iwakura, Naoya Takayama, Jun Ooehara, Makoto Otsu, Akihide Kamiya, Brian G Petrich, Tetsumei Urano, Takafumi Kadono, Shinichi Sato, Atsu Aiba, Hiroshi Yamashita, Seiryo Sugiura, Takashi Kadowaki, Hiromitsu Nakauchi, Koji Eto, Ryozo Nagai
    Blood 119 8 e45-56 - E56 2012年02月 [査読有り][通常論文]
     
    The mechanism by which thrombotic vessel occlusion occurs independently of plaque development or endothelial cell (EC) disruption remains unclear, largely because of an inability to visualize the formation of thrombus, especially at the single-platelet level in real time. Here we demonstrate that rapidly developing thrombi composed of discoid platelets can be induced in the mesenteric capillaries, arterioles, and large-sized arteries of living mice, enabling characterization of the kinetics of thrombosis initiation and the multicellular interrelationships during thrombus development. Platelet aggregation without EC disruption was triggered by reactive oxygen species (ROS) photochemically induced by moderate power laser irradiation. The inflammatory cytokines TNF-α and IL-1 could be key components of the EC response, acting through regulation of VWF mobilization to the cell surface. Thrombus formation was then initiated by the binding of platelet GPIbα to endothelial VWF in our model, and this effect was inhibited by the ROS scavenger N-acetylcysteine. Actin linker talin-dependent activation of alphaIIb-beta3 integrin or Rac1 in platelets was required for late-phase thrombus stability. Our novel imaging technology illustrates the molecular mechanism underlying inflammation-based thrombus formation by discoid platelets on undisrupted ECs and suggests control of ROS could be a useful therapeutic target for the prevention of thrombotic diseases.
  • Zenshiro Tamaki, Yoshihide Asano, Masaru Hatano, Atsushi Yao, Tomohiko Kawashima, Manabu Tomita, Koichiro Kinugawa, Ryozo Nagai, Shinichi Sato
    Modern Rheumatology 22 1 94 - 99 2012年02月 [査読有り][通常論文]
     
    In this pilot study, the effect of low-dose imatinib mesylate (100 mg/day) on cutaneous involvement in patients with systemic sclerosis (SSc) was analyzed. Three patients with SSc were treated with 100 mg/day of imatinib mesylate for 6 months because of pulmonary arterial hypertension refractory to conventional treatments, including beraprost, bosentan, sildenafil, and epoprostenol. Changes in cutaneous involvement were evaluated at 1, 3, and 6 months. During the treatment, the total skin score gradually improved in all of the patients. Contracture of phalanges was attenuated in two patients, one of whom also experienced the partial restoration of large-joint mobility. Nailfold bleeding, initially seen in two patients, was gradually attenuated and had completely disappeared at 6 months. In all patients, Raynaud's phenomenon was attenuated at around 3 months and had completely disappeared at 6 months. Although transient renal dysfunction was observed in one patient, none of the patients experienced common adverse effects of imatinib, such as edema, nausea, rash, and musculoskeletal pain. These clinical data indicate the tolerability and efficacy of low-dose imatinib in SSc, especially against cutaneous vascular involvement, including Raynaud's phenomenon and nailfold bleeding. © Japan College of Rheumatology 2011.
  • Takeki Suzuki, Takahide Kohro, Doubun Hayashi, Tsutomu Yamazaki, Ryozo Nagai
    American heart journal 163 2 268 - 73 2012年02月 [査読有り][通常論文]
     
    BACKGROUND: Lifestyle modifications such as exercise and diet interventions in patients with coronary artery disease (CAD) are widely regarded as important, but little is known about their frequency in clinical practice and their impact on all-cause mortality. METHODS: The JCAD study is a cohort study of 13,812 patients with CAD (≥75% stenosis in ≥1 of 3 major coronary arteries). Patients were enrolled from April 2000 through March 2001 at 202 institutions throughout Japan. Exercise and diet interventions were defined based on Japanese national guidelines. Cox proportional hazards models were used to calculate hazard ratios (HRs) for all-cause mortality with 95% CIs. RESULTS: We studied 11,893 patients in the JCAD study. Over 3 years of follow-up, there were 474 deaths; 4,237 patients (35.6%) underwent exercise intervention, and 8,642 patients (72.7%) underwent diet intervention from the time of discharge. Mortality was lower in patients who underwent an exercise or diet intervention than in patients who did not: HR 0.68 (95% CI 0.56-0.84) and 0.75 (95% CI 0.62-0.91), respectively. After adjustment for age, sex, institution, hypertension, hyperlipidemia, diabetes, obesity, current drinking, current smoking, and the use of antiplatelet agents, β-blockers, angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, and statins, the associations with these interventions remain statistically significant: HR 0.73 (95% CI 0.55-0.96) for exercise and 0.74 (95% CI 0.58-0.95) for diet interventions. CONCLUSIONS: Exercise and diet interventions have a beneficial impact on all-cause mortality in patients with CAD, yet these interventions are surprisingly infrequent. Lifestyle interventions should be more actively promoted.
  • Teruhiko Imamura, Koichiro Kinugawa, Taro Shiga, Naoko Kato, Miyoko Endo, Toshiro Inaba, Hisataka Maki, Masaru Hatano, Atsushi Yao, Yasunobu Hirata, Takashi Nishimura, Shunei Kyo, Minoru Ono, Ryozo Nagai
    International heart journal 53 6 391 - 3 2012年 [査読有り][通常論文]
     
    Hypervolemic hyponatremia is often complicated with advanced heart failure together with increased excretion of sodium by diuretics. Tolvaptan, an oral vasopressin-2-receptor antagonist, has been previously reported to improve congestion and correct hyponatremia through increased excretion of free water. However, there is little evidence concerning the administration of tolvaptan in patients with stage D heart failure. We experienced 2 patients with stage D heart failure who received 3.75 mg/day of tolvaptan to correct hyponatremia before ventricular assist device implantation. It may be useful, even for patients with stage D heart failure, to administer a low dose of tolvaptan to treat hyponatremia before ventricular assist device implantation to avoid a drastic alteration in serum sodium concentration perioperatively.
  • Taro Shiga, Koichiro Kinugawa, Teruhiko Imamura, Naoko Kato, Miyoko Endo, Toshiro Inaba, Hisataka Maki, Masaru Hatano, Atsushi Yao, Takashi Nishimura, Yasunobu Hirata, Shunei Kyo, Minoru Ono, Ryozo Nagai
    Circulation journal : official journal of the Japanese Circulation Society 76 12 2785 - 91 2012年 [査読有り][通常論文]
     
    BACKGROUND: Patients with biventricular assist device (BiVAD) placement have a poor prognosis, but preoperative risk factors for the necessity of BiVAD have not been fully elucidated. METHODS AND RESULTS: Data from 79 patients who received left ventricular assist device (LVAD) between November 2002 and December 2011 were retrospectively reviewed. Overall, 9 patients (11.4%) required BiVAD, and the survival rate of BiVAD patients was significantly lower than that of LVAD patients (P<0.001). Multivariate analysis for BiVAD requirement showed left ventricular diastolic diameter (LVDd) ≤62 mm (odds ratio [OR], 10.97; P=0.009) to be significantly associated with BiVAD requirement. Preoperative central venous pressure (CVP)/pulmonary capillary wedge pressure (PCWP) ratio ≥0.5 (OR, 13.09; P=0.028) was also significantly associated with BiVAD requirement. A new scoring system for predicting BiVAD requirement was created from the combination of CVP/PCWP ratio (≥0.5), body surface area (≤1.4 m(2)), preoperative continuous hemodiafiltration use, B-type natriuretic peptide (≥1,200 pg/ml) and LVDd (≤62 mm), and this had a significantly larger area under the curve (0.909; P=0.003) than right ventricular stroke work index on receiver operating characteristic analysis. A score >20 using the new scoring method indicated significantly high probability of BiVAD requirement (OR, 16.00; P=0.019). CONCLUSIONS: The new scoring method, which includes CVP/PCWP ratio, is a novel risk stratification tool for BiVAD therapy.
  • Susumu Miyazaki, Katsuhito Fujiu, Hiroaki Sugiyama, Takahide Murasawa, Jun Yokota, Keigo Iwazaki, Toshiya Kojima, Takeki Suzuki, Kazuo Asada, Hisayoshi Tamai, Yasushi Imai, Hiroshi Yamashita, Yasunobu Hirata, Ryozo Nagai
    Journal of Arrhythmia 28 5 300 - 304 2012年 [査読有り][通常論文]
     
    We report on a 64-year-old female patient who underwent cardiac surgery for left atrial myxoma, using the superior septal approach with large atrial septal wall resection and patch closure. The superior septal approach is reported to be a relatively safe method for preventing the development of sinus node dysfunction after cardiac surgery. However, this patient developed sinus node dysfunction after surgery and required the implantation of a permanent pacemaker. Moreover, in this case, determining the appropriate positions of the pacemaker leads was difficult because of the presence of a large conduction delay in the interatrium. Selecting the appropriate atrioventricular delay settings was important in order to achieve proper sequential contractions between the left atrium and the left ventricle. © 2012 Japanese Heart Rhythm Society.
  • Junichi Ishida, Toru Suzuki, Kenichi Aizawa, Daigo Sawaki, Ryozo Nagai
    International heart journal 53 5 320 - 3 2012年 [査読有り][通常論文]
     
    Rapid measurement of B-type natriuretic peptide (BNP) plays a practical role in the diagnosis of congestive heart failure. Analytical evaluation of a new small-footprint immunochromatography reader of BNP (Rapidpia®) was performed and compared with the commercially available SHIONOSPOT® Reader as the index. The new BNP assay had a within-run coefficient of variation (CV) of 9.0% and a between-run CV of 2.1%. Correlations between whole blood and plasma samples and those with the index SHIONOSPOT® Reader were y = 0.93x + 0.88, R2 = 0.98 and y = 1.08x - 6.67, R2 = 0.93, respectively. Based on our findings, the two point-of care (POC) assays for BNP, Rapidpia® and SHIONOSPOT® Reader, showed comparable results.
  • Teruhiko Imamura, Koichiro Kinugawa, Dai Mohri, Taro Shiga, Miyoko Endo, Toshiro Inaba, Hisataka Maki, Masaru Hatano, Hiroyuki Isayama, Atsushi Yao, Yasunobu Hirata, Kazuhiko Koike, Ryozo Nagai
    International heart journal 53 3 205 - 7 2012年 [査読有り][通常論文]
     
    Malignancy is not uncommon with immunosuppressive therapy, but pancreatic cancer is infrequently complicated in recipients of heart transplantation. Here we report a transplant case diagnosed with pancreatic cancer 4 years and 8 months after the heart transplantation. We changed the immunosuppressive regimen after the malignancy was detected, and administered everolimus along with chemotherapy using S-1, an oral fluoropyrimidine prodrug. The patient lived for 8 months after the diagnosis, and received metallic stenting for the biliary and duodenal obstruction. Also, to the best of our knowledge, this is the first report about chemotherapy and endoscopic intervention for pancreatic cancer in a heart transplantation patient.
  • Teruhiko Imamura, Taro Shiga, Koichiro Kinugawa, Naoko Kato, Miyoko Endo, Toshiro Inaba, Hisataka Maki, Masaru Hatano, Atsushi Yao, Yasunobu Hirata, Ryozo Nagai
    International heart journal 53 3 199 - 201 2012年 [査読有り][通常論文]
     
    Cytomegalovirus (CMV) infection remains a major problem in recipients with heart transplantation (HTx), because it may play a significant role in the development of cardiac allograft vasculopathy, which is one of the major causes of death after HTx. Valganciclovir (VGC) is effective for the treatment of CMV infection, but is often associated with neutropenia, especially when used with mycophenolate mophetil (MMF). We experienced an HTx recipient with positive CMV antigenemia who suffered progressive neutropenia after administration of VGC. We switched MMF to everolimus (EVL) and assay for CMV antigenemia was constantly negative even after discontinuation of VGC. In all other 14 HTx recipients who received EVL for any reason, we found that assay for CMV antigenemia remained negative throughout the period of EVL administration. Considering the prophylactic effect on CMV, EVL can not only be an alternative to rescue from comorbidity, but might also be indicated earlier especially in CMV-seronegative HTx recipients.
  • Taira Fukuda, Akihiro Matsumoto, Miwa Kurano, Haruhito Takano, Haruko Iida, Toshihiro Morita, Hiroshi Yamashita, Yasunobu Hirata, Ryozo Nagai, Toshiaki Nakajima
    International heart journal 53 5 293 - 8 2012年 [査読有り][通常論文]
     
    The purpose of this study was to investigate the precise pattern of stroke volume (SV) response during exercise in patients with chronic heart failure (CHF) compared with age-matched controls. Fourteen patients with CHF and 7 controls performed symptom-limited bicycle exercise testing with respiratory gas exchange measurement. Patients were classified into group A (n = 7) with peak VO2 ≥ 18.0 mL/kg/minute and group B (n = 7) with peak VO2 < 18.0 mL/kg/ minute. SV and cardiac output (CO) were continuously measured during exercise using a novel thoracic impedance method (Physioflow). CO and SV were lower in the group B patients than those in controls at peak exercise [CO: 11.3 ± 1.0 (SE) versus 15.6 ± 0.9 L/minute, P < 0.05, SV: 89 ± 6 versus 110 ± 6 mL, P < 0.05]. SV reached its peak levels during submaximal exercise and remained close to the peak value until peak exercise in 6 of 7 group B patients (86%). On the other hand, it progressively increased until peak exercise in 6 of 7 controls (86%) and 5 of 7 group A patients (71%). In all subjects, CO at peak exercise was more closely correlated with SV at peak exercise (r = 0.86, P < 0.001) than with peak heart rate (r = 0.69, P < 0.001). CHF patients with impaired exercise capacity had attenuated increment of CO during exercise, and SV reached its peak levels during submaximal exercise.
  • Naho Kobayashi, Jun-ichi Suzuki, Masahito Ogawa, Norio Aoyama, Tomoya Hanatani, Yasunobu Hirata, Ryozo Nagai, Yuichi Izumi, Mitsuaki Isobe
    Journal of vascular research 49 5 417 - 24 2012年 [査読有り][通常論文]
     
    BACKGROUND: Inflammation plays a key role in neointimal hyperplasia after an arterial injury. Chronic infectious disorders, such as periodontitis, are associated with an increased risk of cardiovascular diseases. However, the effects of a periodontal infection on vascular remodeling have not been examined. We assess the hypothesis that periodontal infection could promote neointimal formation after an arterial injury. METHODS: Mice were implanted with subcutaneous chambers (n = 41). Two weeks after implantation, the femoral arteries were injured, and Porphyromonas gingivalis (n = 21) or phosphate-buffered saline (n = 20) was injected into the chamber. The murine femoral arteries were obtained for the histopathological analysis. The expression level of mRNA in the femoral arteries was analyzed using quantitative reverse transcriptase polymerase chain reaction (n = 19-20). RESULTS: The intima/media thickness ratio in the P. gingivalis infected group was found to be significantly increased in comparison to the non-infected group. The expression of matrix metalloproteinase-2 mRNA was significantly increased in the P. gingivalis infected group compared to the non-infected group. CONCLUSION: These findings demonstrate that P. gingivalis injection can promote neointimal formation after an arterial injury. Periodontitis may be a critical factor in the development of restenosis after arterial intervention.
  • Junichi Ishida, Koichiro Kinugawa, Taro Shiga, Teruhiko Imamura, Masaru Hatano, Hisataka Maki, Toshiro Inaba, Atsushi Yao, Yasunobu Hirata, Takashi Nishimura, Shunei Kyo, Minoru Ono, Ryozo Nagai
    International heart journal 53 6 388 - 90 2012年 [査読有り][通常論文]
     
    A 60-year-old man with severe heart failure underwent an orthotopic heart transplant. Maintenance immunosuppression consisted of a calcineurin inhibitor, mycophenolate mofetil (MMF), and a glucocorticoid. Six months after the transplantation, coronary angiography (CAG) and intravascular ultrasound sonography (IVUS) showed rapidly progressive cardiac allograft vasculopathy (CAV) along with acute cellular rejection. Methylprednisone pulse therapy resulted in the resolution of acute rejection. MMF was exchanged for everolimus (EVL) and 6 months after EVL therapy, CAG and IVUS revealed the regression of CAV. EVL can improve established CAV as well as prevent the progression of CAV.
  • Jun-ichi Suzuki, Masahito Ogawa, Yoshiki Sakai, Yasunobu Hirata, Mitsuaki Isobe, Ryozo Nagai
    International heart journal 53 1 64 - 7 2012年 [査読有り][通常論文]
     
    ONO-1301MS is a compound that acts as a prostacyclin agonist with thromboxane A2 synthase inhibitory activity. We investigated the effect of ONO-1301MS on myocardial remodeling in murine cardiac allografts. The hearts of Balb/c mice were transplanted into C3H/He mice (a full allomismatch combination) to assess acute rejection or C57BL/6 hearts into B6.C-H2(‹bm12›) KhEg (a class II mismatch combination) to examine chronic rejection. ONO-1301MS did not prolong full allomismatch cardiac graft survival. Severe myocardial fibrosis with high collagen concentration was observed in untreated class II mismatch allografts on day 60. However, significantly suppressed myocardial fibrosis with less collagen synthesis was observed in the ONO-1301MS-treated group compared to the control group. ONO-1301MS could be an effective strategy to suppress chronic myocardial remodeling in cardiac transplantation.
  • Teruhiko Imamura, Koichiro Kinugawa, Taro Shiga, Miyoko Endo, Naoko Kato, Toshiro Inaba, Hisataka Maki, Masaru Hatano, Atsushi Yao, Takashi Nishimura, Yasunobu Hirata, Shunei Kyo, Minoru Ono, Ryozo Nagai
    Circulation journal : official journal of the Japanese Circulation Society 76 8 1895 - 903 2012年 [査読有り][通常論文]
     
    BACKGROUND: As we have previously reported, the preoperative profile defined by INTERMACS is a good predictor for the prognosis after left ventricular assist device (LVAD) implantation, but is largely dependent on the physician's decision. Several other risk stratification systems including objective parameters (eg, Leitz-Miller, Columbia, Seattle Heart Failure Model, APACHE II) have been proposed to estimate patient's mortality after LVAD implantation. METHODS AND RESULTS: According to the preoperative data from 59 patients who received LVAD (10 implantable, 49 extracorporeal) since 2002 through 2010, we performed a logistic analysis and constructed a new scoring system (ie, the TODAI VAD score (TVAD score), assigning 8 points to serum albumin <3.2mg/dl (odds ratio [OR] 8.475), 7 points to serum total bilirubin >4.8mg/dl (OR 7.300), 6 points to left ventricular end-diastolic diameter <55mm (OR 5.917), 5 points to central venous pressure >11mmHg (OR 5.128)). The receiver-operating characteristic analysis showed that the area under the curve of our new scoring system (0.864) was significantly larger than any of the abovementioned 5 scoring methods (all P<0.05). With the TVAD score, low (0-8 points), intermediate (9-17 points), and high (18-26 points) risk strata had significantly different 1-year survival rates of 95%, 54%, and 14%, respectively (all P<0.001). CONCLUSIONS: The TVAD score can predict the prognosis after LVAD implantation much better than the previously known methods.
  • Tomoya Hanatani, Jun-ichi Suzuki, Masahito Ogawa, Norio Aoyama, Naho Kobayashi, Yasunobu Hirata, Ryozo Nagai, Yuichi Izumi, Mitsuaki Isobe
    International heart journal 53 4 253 - 6 2012年 [査読有り][通常論文]
     
    Chronic inflammation plays a fundamental role in coronary heart disease (CHD). Periodontal disease is a common infectious disease and is a potential source of systemic inflammation. However, the effect of periodontal infection on CHD has not yet been proven. The purpose of this study was to determine the effect of periodontopathic bacteria on experimental myocardial infarction (MI). We implanted a chamber into the subcutaneous tissue of each male mouse. Aggregatibacter actinomycetemcomitans (A.a. n = 8), which is a major periodontal pathogen, or PBS (n = 6) was injected into the chamber. Then, MI was induced by permanent ligation of the left anterior descending coronary artery. To exclude the nonspecific effect of the pathogen, we injected A.a. into the mice without MI (n = 4). The plasma level of anti-A.a. antibody was statistically higher in A.a.-infected mice than in vehicle control mice. Seven days after the myocardial ischemia, the A.a.-positive MI hearts showed a larger infarct size and length than the A.a.-negative MI mice. The A.a.-positive MI hearts showed more MOMA-2 positive myocardial infiltrating cells compared to the A.a.-negative MI mice. The injection of A.a. into the mice without MI did not affect their hearts. We concluded that a periodontal pathogen infection might deteriorate ventricular remodeling after MI through inflammatory cell infiltration.
  • Rikuta Hamaya, Masahito Ogawa, Naho Kobayashi, Jun-Ichi Suzuki, Akiko Itai, Yasunobu Hirata, Ryozo Nagai, Mitsuaki Isobe
    International heart journal 53 2 133 - 8 2012年 [査読有り][通常論文]
     
    Restenosis after percutaneous coronary intervention (PCI) is still a clinically serious problem. We examined the treatment efficacy of IMD-0354, a novel IKK inhibitor, on arteriopathy. Using C57BL/6J mice, a wire-injury model was prepared and the mice were intraperitoneally injected with IMD-0354 or vehicle twice a day. The vehicle-treated injured arteries showed significantly thickened intima (3.77 ± 0.59, n = 8), however, IMD-0354 suppressed its progression (1.62 ± 0.22, n = 10, P < 0.05) on day 28. While enhanced expression of PCNA and NF-κB was observed in the untreated injured arteries, IMD-0354 significantly suppressed their expressions. Quantitative RT-PCR revealed that the expression of several inflammatory factors was reduced in the arteries from mice which received IMD-0354 treatment compared with the control animals. Thus, this drug may effectively prevent restenosis after coronary intervention and other cardiovascular diseases.
  • Asuka Sekinishi, Jun-Ichi Suzuki, Norio Aoyama, Masahito Ogawa, Ryo Watanabe, Naho Kobayashi, Tomoya Hanatani, Norihiko Ashigaki, Yasunobu Hirata, Ryozo Nagai, Yuichi Izumi, Mitsuaki Isobe
    International heart journal 53 5 324 - 30 2012年 [査読有り][通常論文]
     
    Although a relationship between periodontitis and myocardial hypertrophy has been reported, the precise mechanism has not been clarified. The purpose of this study was to investigate the association between periodontal infection and myocardial hypertrophy. Transverse aortic constriction (TAC) was performed. Mice were injected with Aggregatibacter actinomycetemcomitans (A.a.) (0.1 mL of 10(8) CFU/mL) in the infected group and PBS in the control group. Echocardiography, histopathology, and immunohistochemistry were performed. Echocardiography indicated that left ventricular fractional shortening had decreased in the infected group compared to the control group on day 28. Heart to body weight ratio increased in the infected group compared to the control group. Histopathologically, A.a.-infected mice showed markedly enhanced cardiac hypertrophy, fibrosis and arteriosclerosis 4 weeks after TAC operation. Immunohistochemistry revealed that expression of MMP-2 in the interstitial tissue was enhanced in the infected group. These results suggested that the periodontal pathogen caused a deterioration of pressure overload-induced myocardial hypertrophy through MMP activation.
  • Hiroaki Semba, Koichiro Kinugawa, Norihiko Takeda, Taro Shiga, Go Nishimura, Tsukasa Inajima, Yuichi Uchino, Hiroshi Iwata, Eriko Hasumi, Hajime Abe, Yumiko Terada, Akihiko Yonenaga, Yasunobu Hirata, Ryozo Nagai
    International heart journal 53 1 72 - 4 2012年 [査読有り][通常論文]
     
    While diuretic drugs are commonly used in patients with congestive heart failure, the efficacy of their long-term use still remains controversial. Recently, a new class of diuretics, vasopressin receptor 2 antagonists, has been launched, and tolvaptan is one such drug. We describe our initial experience with this novel agent. Tolvaptan is potentially useful for treatment of heart failure patients with fluid overload who are refractory to conventional diuretic therapies.
  • Hajime Abe, Norihiko Takeda, Hajime Aoki, Ryozo Nagai
    INTERNAL MEDICINE 51 10 1275 - 1275 2012年 [査読有り][通常論文]
  • Katsura Soma, Hajime Abe, Norihiko Takeda, Yukako Shintani, Yutaka Takazawa, Toshiya Kojima, Katsuhito Fujiu, Hiroaki Semba, Hiroshi Yamashita, Yasunobu Hirata, Masashi Fukayama, Ryozo Nagai
    International heart journal 53 1 75 - 7 2012年 [査読有り][通常論文]
     
    Mitral and aortic valve regurgitation is commonly found in osteogenesis imperfecta (OI) patients, however, little is known about the myocardial involvement in this disorder. An 82-year-old man with OI developed heart failure and was admitted to our hospital. Echocardiogram revealed severe mitral regurgitation without left ventricular (LV) dilatation, but with LV wall thickening. Histological analysis exhibited interstitial fibrosis of the myocardium in addition to myxoid changes of the mitral leaflet. These findings suggest that OI patients may develop LV remodeling together with diastolic dysfunction.
  • Kazuo Asada, Katsuhito Fujiu, Yasushi Imai, Toshiya Kojima, Hiroaki Sugiyama, Takeki Suzuki, Koichiro Kinugawa, Yasunobu Hirata, Ryozo Nagai
    Circulation journal : official journal of the Japanese Circulation Society 76 11 2592 - 8 2012年 [査読有り][通常論文]
     
    BACKGROUND: Cardiac resynchronization therapy/defibrillators (CRTD) and implantable cardioverter defibrillators (ICD) with continuous intrathoracic impedance monitoring might provide an early warning of thoracic fluid retention. In contrast, volume loss events such as dehydration and bleeding are also common events in heart failure patients treated with diuretics and anticoagulants. The correlation between intrathoracic impedance and a volume loss event is not known. METHODS AND RESULTS: This study evaluated the association between intrathoracic impedance and volume loss events in 36 patients with chronic heart failure (New York Heart Association [NYHA] II, III and IV) who had received CRTD/ICD implantation. Elevation of thoracic impedance above the reference line was defined as a positive deviation of thoracic impedance (PDI). This study recorded 249 PDIs including 60 spike PDIs defined as over 5 ohms elevation from the reference line and 17 large PDIs as over 5 ohms elevation and continuing for at least 4 days. Clinically, 96 dehydration events and 2 bleeding events were observed over a 1-year period. The sensitivity and positive predictive value (PPV) for spike PDI was 31.6% and 51.7%, respectively, while those for large PDI were 17.3% and 100%, respectively. CONCLUSIONS: A large PDI reflected dehydration and bleeding events with a high PPV in severe heart failure patients. The large PDI criteria might therefore be useful for predicting volume loss events in chronic heart failure patients.
  • Makoto Sahara, Masataka Sata, Toshihiro Morita, Yasunobu Hirata, Ryozo Nagai
    PloS one 7 3 e33367  2012年 [査読有り][通常論文]
     
    BACKGROUND: An antianginal K(ATP) channel opener nicorandil has various beneficial effects on cardiovascular systems; however, its effects on pulmonary vasculature under pulmonary arterial hypertension (PAH) have not yet been elucidated. Therefore, we attempted to determine whether nicorandil can attenuate monocrotaline (MCT)-induced PAH in rats. MATERIALS AND METHODS: Sprague-Dawley rats injected intraperitoneally with 60 mg/kg MCT were randomized to receive either vehicle; nicorandil (5.0 mg·kg(-1)·day(-1)) alone; or nicorandil as well as either a K(ATP) channel blocker glibenclamide or a nitric oxide synthase (NOS) inhibitor N(ω)-nitro-L-arginine methyl ester (L-NAME), from immediately or 21 days after MCT injection. Four or five weeks later, right ventricular systolic pressure (RVSP) was measured, and lung tissue was harvested. Also, we evaluated the nicorandil-induced anti-apoptotic effects and activation status of several molecules in cell survival signaling pathway in vitro using human umbilical vein endothelial cells (HUVECs). RESULTS: Four weeks after MCT injection, RVSP was significantly increased in the vehicle-treated group (51.0±4.7 mm Hg), whereas it was attenuated by nicorandil treatment (33.2±3.9 mm Hg; P<0.01). Nicorandil protected pulmonary endothelium from the MCT-induced thromboemboli formation and induction of apoptosis, accompanied with both upregulation of endothelial NOS (eNOS) expression and downregulation of cleaved caspase-3 expression. Late treatment with nicorandil for the established PAH was also effective in suppressing the additional progression of PAH. These beneficial effects of nicorandil were blocked similarly by glibenclamide and l-NAME. Next, HUVECs were incubated in serum-free medium and then exhibited apoptotic morphology, while these changes were significantly attenuated by nicorandil administration. Nicorandil activated the phosphatidylinositol 3-kinase (PI3K)/Akt and extracellular signal-regulated kinase (ERK) pathways in HUVECs, accompanied with the upregulation of both eNOS and Bcl-2 expression. CONCLUSIONS: Nicorandil attenuated MCT-induced vascular endothelial damage and PAH through production of eNOS and anti-apoptotic factors, suggesting that nicorandil might have a promising therapeutic potential for PAH.
  • Takahide Kohro, Hiroshi Iwata, Katsuhito Fujiu, Ichiro Manabe, Hideo Fujita, Go Haraguchi, Yoshihiro Morino, Atsushi Oguri, Hiroshi Ikenouchi, Masahiko Kurabayashi, Yuji Ikari, Mitsuaki Isobe, Kazuhiko Ohe, Ryozo Nagai
    International heart journal 53 1 35 - 42 2012年 [査読有り][通常論文]
     
    The 'evidence' in evidence-based medicine (EBM) is often limited to knowledge obtained from randomized controlled clinical trials (RCT). Most RCTs, however, have strict enrollment criteria which make patient background characteristics and clinical histories significantly different from those encountered in actual practice. Thus it is important to accumulate and analyze data obtained in daily practice to gain insight into a larger clinical picture. Recent developments in information technology and its lowered cost have enabled us to record clinical activity in much greater detail at a lower cost. These factors prompted us to design and develop a coronary angiography and intervention reporting system (CAIRS) to collect data and analyze outcomes of coronary intervention. The resulting advanced CAIRS can record detailed data on coronary angiographic and interventional procedures.To date, data on 10,025 cases of coronary angiography, of which 3,574 were interventional, have been collected over a 5.5 year period. There were 4,343 unique patients, 3,115 (71.7%) of which were male. The overall mean age was 67.0 ± 11.5. The mean age of males was 66.3 ± 11.4 and that of females was 69.0 ± 11.4. About one-third of the patients never underwent a PCI procedure at our institution. For patients that underwent at least one PCI procedure at our institution, the prescription rate of statin increased from 50.8% in 2005 to 80.3% in 2011, while those of nitrate and ticlopidine decreased from 36.7% and 90.8% in 2005 to 21.3% and 0.8% in 2011, respectively. We have also implemented the same system at another institution and compared the data on stent usage between the two institutions, which revealed vastly different stent usage profiles.In conclusion, we have successfully developed and implemented an advanced coronary angiography and intervention reporting system which we call CAIRS. Implementing the same system at multiple institutions and analyzing data collected from several institutions will provide detailed and timely insight into the 'real world' of coronary angiography and interventional procedures and their outcome.
  • Yasutomi Higashikuni, Minoru Takaoka, Hiroshi Iwata, Kimie Tanaka, Yasunobu Hirata, Ryozo Nagai, Masataka Sata
    Hypertension research : official journal of the Japanese Society of Hypertension 35 1 62 - 9 2012年01月 [査読有り][通常論文]
     
    The efficacy of aliskiren, a direct renin inhibitor, in ventricular remodeling after myocardial infarction (MI) compared with conventional renin-angiotensin system (RAS) inhibitors remains to be defined. This study was performed to examine the protective effects of aliskiren and its addition to valsartan, an angiotensin-II receptor blocker, against ventricular remodeling after MI. MI was induced in 8- to 12-week-old C57BL/6 mice by ligating the left anterior descending artery. At 3 days after MI, mice were divided into five groups and were treated with the following: (1) phosphate-buffered saline (PBS); (2) hydralazine (10 mg kg(-1) day(-1)); (3) valsartan (8 mg kg(-1) day(-1)); (4) aliskiren (25 mg kg(-1) day(-1)); and (5) combined aliskiren (25 mg kg(-1) day(-1)) and valsartan (8 mg kg(-1) day(-1)). With these doses of drugs, blood pressure-lowering effects compared with the PBS group were similar among the treated groups in sham-operated mice. At 28 days after MI, echocardiographic, hemodynamic and histological assessments demonstrated that monotherapy with valsartan or aliskiren alone significantly and similarly ameliorated ventricular remodeling after MI compared with the PBS and the hydralazine groups. Combination therapy of valsartan and aliskiren more greatly improved ventricular remodeling after MI with enhancement of angiogenesis and greater attenuation of tissue oxidative stress and inflammation. Our results indicate that aliskiren can be an alternative to conventional RAS inhibitors in the treatment of post-MI patients. Moreover, the dual therapy of valsartan and aliskiren may be more beneficial than either monotherapy. Further clinical trials will be warranted to sufficiently assess the safety and the efficacy of the use of aliskiren in post-MI patients.
  • Naomi Ogawa, Yasushi Imai, Yuji Takahashi, Kan Nawata, Kazuo Hara, Hiroshi Nishimura, Masayoshi Kato, Norifumi Takeda, Takahide Kohro, Hiroyuki Morita, Tsuyoshi Taketani, Tetsuro Morota, Tsutomu Yamazaki, Jun Goto, Shoji Tsuji, Shinichi Takamoto, Ryozo Nagai, Yasunobu Hirata
    The American journal of cardiology 108 12 1801 - 7 2011年12月 [査読有り][通常論文]
     
    Marfan syndrome (MS) is an inherited connective tissue disorder, and detailed evaluations of multiple organ systems are required for its diagnosis. Genetic testing of the disease-causing fibrillin-1 gene (FBN1) is also important in this diagnostic scheme. The aim of this study was to define the clinical characteristics of Japanese patients with MS and enable the efficient and accurate diagnosis of MS with mutational analysis using a high-throughput microarray-based resequencing system. Fifty-three Japanese probands were recruited, and their clinical characteristics were evaluated using the Ghent criteria. For mutational analysis, an oligonucleotide microarray was designed to interrogate FBN1, and the entire exon and exon-intron boundaries of FBN1 were sequenced. Clinical evaluation revealed more pulmonary phenotypes and fewer skeletal phenotypes in Japanese patients with MS compared to Caucasians. The microarray-based resequencing system detected 35 kinds of mutations, including 23 new mutations. The mutation detection rate for patients who fulfilled the Ghent criteria reached 71%. Of note, splicing mutations accounted for 19% of all mutations, which is more than previously reported. In conclusion, this comprehensive approach successfully detected clinical phenotypes of Japanese patients with MS and demonstrated the usefulness and feasibility of this microarray-based high-throughput resequencing system for mutational analysis of MS.
  • Takeki Suzuki, Tsutomu Yamazaki, Satoshi Ogawa, Ryozo Nagai, Takeshi Yamashita
    Heart rhythm 8 12 1831 - 6 2011年12月 [査読有り][通常論文]
     
    BACKGROUND: Little is known about associations among echocardiographic variables, frequency of atrial fibrillation (AF), and progression from paroxysmal to persistent AF. OBJECTIVE: The purpose of this study was to investigate echocardiographic predictors of frequency of paroxysmal AF and its progression to persistent AF in hypertensive patients with paroxysmal AF. METHODS: We used data from 286 patients with paroxysmal AF and hypertension in the Japanese Rhythm Management Trial II for Atrial Fibrillation (J-RHYTHM II Study). Echocardiographic evaluation was performed at baseline. Endpoints were (1) percent of AF days measured daily by transtelephonic monitoring over 1 year and (2) development of persistent AF, defined as incidence of AF lasting for longer than 7 days and/or need for electrical cardioversion. Univariate and multivariate linear regression analysis was performed to evaluate the association between echocardiographic variables and percent of AF days. Cox proportional hazards analysis was used to examine the association between echocardiographic variables and development of persistent AF. RESULTS: Among echocardiographic variables, increased left atrial dimension (LAD) was associated with more AF days and development of persistent AF: a 10-mm increase in LAD was associated with a 6.5% increase in AF days (95% confidence interval 2.7%-10.3%) and an 84% increased risk of developing persistent AF (hazard ratio 1.84, 95% confidence interval 1.28-2.67). These associations remained significant after adjustment for age, sex, and other potential confounding factors. CONCLUSION: Increased LAD is associated with more AF days and progression from paroxysmal to persistent AF in patients with paroxysmal AF and hypertension. Increased LAD may be a good echocardiographic predictor of AF frequency and progression.
  • Arihiro Kiyosue, Daisuke Nagata, Masahiro Myojo, Tomohiko Sato, Masao Takahashi, Hiroshi Satonaka, Ryozo Nagai, Yasunobu Hirata
    Hypertension research : official journal of the Japanese Society of Hypertension 34 12 1283 - 7 2011年12月 [査読有り][通常論文]
     
    Osteopontin (OPN) is known to be one of the cytokines that is involved in the vascular inflammation caused by aldosterone (Aldo). Previous reports have shown that Aldo increases OPN transcripts, and the mechanisms for this remain to be clarified. In this study, we investigated how Aldo increases OPN transcripts in the vascular smooth muscle cells of rats. Aldosterone increased OPN transcripts time-dependently as well as dose-dependently. This increase was diminished by eplerenone, a mineralocorticoid receptor (MR) antagonist. Luciferase promoter assays showed that the OPN promoter deleted to the -1599 site retained the same promoting ability as the full-length OPN promoter when stimulated by 10(-7) M Aldo, but the promoter deleted to the -1300 site lost the promoting ability. A glucocorticoid response element (GRE) is located in that deleted region. Luciferase assays of a mutated promoter without the GRE lost the luciferase upregulation, although mutated promoters with the deletion of other consensus sites maintained the promoter activity. The binding of the Aldo-MR complex to the GRE fragment was confirmed by an electrophoretic-mobility shift assay. This is the first report showing that Aldo regulates the transcriptional levels of OPN and inflammatory responses in the vasculature through a specific GRE site in the OPN promoter region.
  • Koichi Kimura, Katsu Takenaka, Aya Ebihara, Kansei Uno, Hiroshi Iwata, Masataka Sata, Takahide Kohro, Hiroyuki Morita, Yutaka Yatomi, Ryozo Nagai
    ECHOCARDIOGRAPHY-A JOURNAL OF CARDIOVASCULAR ULTRASOUND AND ALLIED TECHNIQUES 28 10 1148 - 1155 2011年11月 [査読有り][通常論文]
     
    Background: The subendocardial myocardium normally has higher systolic strain than the subepicardial myocardium and can be damaged first in face of ischemia. We investigated the reproducibility and feasibility of novel three-layer speckle tracking system and compared the diagnostic accuracy with experienced visual interpretation. Methods: An ameroid constrictor was placed around the proximal left circumflex (LCX) coronary artery in 19 pigs. Four weeks later, subtotal stenosis was confirmed in all pigs by coronary angiogram. Two dead pigs and three pigs with pathological infarction were excluded. Transthoracic left ventricle (LV) short-axis echocardiograms were recorded at rest before and 4 weeks after the operation. LV posterior wall motion was scored by two experienced doctors and analyzed by the speckle tracking system (n = 14). Results: Strain variables gave reasonable intra/interobserver reproducibility (mean absolute percentage errors = 13/19, intraclass correlation coefficients = 0.97/0.92). All strain variables and visual wall-motion scores changed significantly during stenosis (P < 0.05). Of all variables, endocardial strains, particularly the circumferential strain demonstrated the highest area under curve (AUC), showing better diagnostic accuracy than experienced visual interpretation (sensitivity 0.93 vs. 0.79, specificity 0.93 vs. 0.73, AUC 0.95 vs. 0.77, P < 0.05). Conclusion: Three-layer speckle tracking is a feasible and reproducible modality. In particular, endocardial speckle tracking provides incremental value in accurately identifying regional ischemia even in the rest echocardiography. (Echocardiography 2011;28:1148-1155)
  • Nobukazu Ishizaka, Aiko Sakamoto, Mitsuhiro Fujishiro, Ryozo Nagai, Kazuhiko Koike
    JOURNAL OF CARDIOLOGY 58 3 199 - 207 2011年11月 [査読有り][通常論文]
     
    Nowadays, antiplatelet and anticoagulant drug medications are indicated in patients with a variety of cardiovascular disorders, such as atrial fibrillation, coronary artery disease, and peripheral artery disease. Among cardiology patients, regardless of gastrointestinal (GI) protection, we do not infrequently encounter those patients who have signs and symptoms that are suggestive of GI tract problems. We should bear in mind that such GI signs and symptoms may be attributed to GI cancers, as well as to benign or clinically insignificant lesions. Several clinical studies have shown, albeit controversially that the predictive value of positive fecal occult blood for colorectal malignant neoplasm may not be lower in patients taking antithrombotic medication. In addition, it has been shown that in patients taking antithrombotic drug(s), diagnosed colorectal malignancies are in a relatively earlier phase, suggesting that antithrombotic drugs may facilitate the detection of otherwise unrecognized cancers. The possibility also exists that certain cardiovascular disease may be associated with a higher risk of GI malignant neoplasms. There has been no established evidence concerning whether more aggressive GI tract screening will reduce the probability of cancer death in cardiology patients; nevertheless, GI tract lesions should not be overlooked among cardiology patients, especially when unexplained anemia, gastrointestinal symptoms, or positive fecal occult blood test is present, and GI tract screening should be performed with appropriate timing. (C) 2011 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.
  • 藤原 隆行, 高田 宗典, 岩田 洋, 小川 直美, 木村 公一, 細谷 弓子, 高橋 政夫, 澤城 大悟, 都島 健介, 安東 治郎, 藤田 英雄, 山下 尋史, 平田 恭信, 永井 良三
    ICUとCCU 35 10 874 - 879 医学図書出版(株) 2011年10月 [査読有り][通常論文]
     
    症例は39歳女性。他院で乏突起膠星細胞腫瘍に対し開頭摘出術を施行後15日目に急性前壁心筋梗塞を発症し当院へ救急搬送された。緊急冠動脈造影にて左前下行枝(LAD)中間部に99%狭窄を認め、引き続き同病変へ経皮的冠動脈形成術を施行した。血管内エコーにて病変は冠動脈解離を伴っていることが明らかとなり、解離腔のエントリー閉鎖を目的にステントを留置した。しかし、ステント近位部に解離が拡大しLADの完全閉塞に陥ったため、さらなるインターベンションによる解離の拡大を懸念し手技を終了した。1週間後の冠動脈CTでは依然完全閉塞であったが、3ヵ月後には解離腔は狭小化し内腔は開存していた。特発性冠動脈解離は極めてまれな疾患であるが、若年女性の急性冠症候群の原因として念頭に置くべきである。(著者抄録)
  • Beth B McConnell, Samuel S Kim, Ke Yu, Amr M Ghaleb, Norifumi Takeda, Ichiro Manabe, Asma Nusrat, Ryozo Nagai, Vincent W Yang
    Gastroenterology 141 4 1302 - 13 2011年10月 [査読有り][通常論文]
     
    BACKGROUND & AIMS: Krüppel-like factor 5 (KLF5) is transcription factor that is expressed by dividing epithelial cells of the intestinal epithelium. KLF5 promotes proliferation in vitro and in vivo and is induced by mitogens and various stress stimuli. To study the role of KLF5 in intestinal epithelial homeostasis, we examined the phenotype of mice with conditional deletion of Klf5 in the gut. METHODS: Mice were generated with intestinal-specific deletion of Klf5 (Vil-Cre;Klf5fl/fl). Morphologic changes in the small intestine and colon were examined by immunohistochemistry, immunoblotting, and real-time polymerase chain reaction. RESULTS: Klf5 mutant mice were born at a normal Mendelian ratio but had high mortality compared with controls. Complete deletion of Klf5 from the intestinal mucosa resulted in neonatal lethality that corresponded with an absence of epithelial proliferation. Variegated intestinal-specific deletion of Klf5 in adult mice resulted in morphologic changes that included a regenerative phenotype, impaired barrier function, and inflammation. Adult mutant mice exhibited defects in epithelial differentiation and migration. These changes were associated with reduced expression of Caudal type homeobox (Cdx) 1, Cdx2, and Eph and ephrin signaling proteins. Concomitantly, Wnt signaling to β-catenin was reduced. Proliferation in regenerative crypts was associated with increased expression of the progenitor cell marker Sox9. CONCLUSIONS: Deletion of Klf5 in the gut epithelium of mice demonstrated that KLF5 maintains epithelial proliferation, differentiation, and cell positioning along the crypt radial axis. Morphologic changes that occur with deletion of Klf5 are associated with disruption of canonical Wnt signaling and increased expression of Sox9.
  • 永井 良三
    日本内科学会雑誌 100 9 2383 - 2401 The Japanese Society of Internal Medicine 2011年09月
  • Hisataka Maki, Atsushi Yao, Toshiro Inaba, Taro Shiga, Masaru Hatano, Koichiro Kinugawa, Takeshi Yamashita, Tadanori Aizawa, Ryozo Nagai
    INTERNATIONAL HEART JOURNAL 52 5 323 - 326 2011年09月 [査読有り][通常論文]
     
    A 49-year-old woman suffering from rapidly progressing right-sided heart failure assessed as World Health Organization functional class (WHO-FC) IV is described. After treatment with oxygen and diuretics, she was in WHO-FC III on admission to our hospital, as confirmed by her poor exercise tolerance in cardiopulmonary exercise testing. Upon detailed examination, she was diagnosed as having idiopathic pulmonary arterial hypertension (IPAH). Right heart catheterization (RHC) revealed severe pulmonary hypertension (mPAP = 65 mmHg) with a markedly decreased cardiac index (CI = 1.0 L/minute/m(2)), and an acute vasoreactivity test with nitric oxide inhalation did not show any response. Due to her severe condition, we decided to attempt oral combination therapy consisting of bosentan, tadalafil, and beraprost, prescribed in the same order and titrated up to their maximum respective doses, instead of intravenous (IV) epoprostenol therapy. Her clinical symptoms improved day by day, and the hemodynamic parameters recovered to nearly normal ranges about 6 months after initiation of the combination therapy. Initial/programmed oral combination therapy for severe IPAH patients is not yet fully established, and there is less evidence concerning its efficacy than IV epoprostenol therapy. However, it has tremendous advantages for PAH patients when they respond well. It is very important to further identify what types of PAH patients will respond to this oral combination therapy and should be treated with it as the first-line therapy. (Int Heart J 2011; 52: 323-326)
  • Katsuhito Fujiu, Ichiro Manabe, Ryozo Nagai
    The Journal of clinical investigation 121 9 3425 - 41 2011年09月 [査読有り][通常論文]
     
    Renal tubulointerstitial damage is the final common pathway leading from chronic kidney disease to end-stage renal disease. Inflammation is clearly involved in tubulointerstitial injury, but it remains unclear how the inflammatory processes are initiated and regulated. Here, we have shown that in the mouse kidney, the transcription factor Krüppel-like factor-5 (KLF5) is mainly expressed in collecting duct epithelial cells and that Klf5 haploinsufficient mice (Klf5+/- mice) exhibit ameliorated renal injury in the unilateral ureteral obstruction (UUO) model of tubulointerstitial disease. Additionally, Klf5 haploinsufficiency reduced accumulation of CD11b+ F4/80(lo) cells, which expressed proinflammatory cytokines and induced apoptosis among renal epithelial cells, phenotypes indicative of M1-type macrophages. By contrast, it increased accumulation of CD11b+ F4/80(hi) macrophages, which expressed CD206 and CD301 and contributed to fibrosis, in part via TGF-β production--phenotypes indicative of M2-type macrophages. Interestingly, KLF5, in concert with C/EBPα, was found to induce expression of the chemotactic proteins S100A8 and S100A9, which recruited inflammatory monocytes to the kidneys and promoted their activation into M1-type macrophages. Finally, assessing the effects of bone marrow-specific Klf5 haploinsufficiency or collecting duct- or myeloid cell-specific Klf5 deletion confirmed that collecting duct expression of Klf5 is essential for inflammatory responses to UUO. Taken together, our results demonstrate that the renal collecting duct plays a pivotal role in the initiation and progression of tubulointerstitial inflammation.
  • Ryota Ochiai, Atsushi Yao, Koichiro Kinugawa, Ryozo Nagai, Isao Shiraishi, Koichiro Niwa
    CIRCULATION JOURNAL 75 9 2220 - 2227 2011年09月 [査読有り][通常論文]
     
    Background: Although the prevalence of adult congenital heart disease (ACHD) in Japan continues to rise, the number and geographic distribution of facilities potentially serving as regional ACHD centers remains unknown. We examined trends in ACHD care in Japan to identify needs and to determine potential regional responses to this growing patient population. Methods and Results: A descriptive, cross-sectional, nationwide survey was conducted to assess the status and needs of cardiology specialists related to providing ACHD care. Questionnaires were mailed to 138 cardiology departments located in 8 geographical regions throughout Japan; respondents were asked to document the status and future direction of ACHD care for each facility. Of the 109 facilities that responded, approximately one-third currently treat or plan to treat all ACHD patients. Fourteen facilities (12.8%) fulfilled all criteria for becoming regional ACHD centers. Although each regional center was projected to serve a population of 9.1 million, in 2 regions, no centers possessed the necessary care structure. Conclusions: Our findings revealed a shortage of adult cardiologists dedicated to ACHD care. Moreover, basic as well as formal fellowship ACHD training was deemed necessary. In Japan, the number of potential regional ACHD centers has just reached international standards. However, based on the geographic gaps documented here, a strategy other than regional centralization might be required to deliver adequate ACHD care to rural areas. (Circ J 2011; 75: 2220-2227)
  • Takumi J. Matsubara, Hiroshi Iwata, Taro Shiga, Masaru Hatano, Atsushi Yao, Minoru Ono, Koichiro Kinugawa, Yasunobu Hirata, Ryozo Nagai
    ASAIO Journal 57 4 346 - 347 2011年07月 [査読有り][通常論文]
     
    Patients who have undergone cardiac transplantation are occasionally complicated by the development of a coronary artery fistula. It has been reported that a majority of coronary artery fistulas in a post-heart transplant setting communicate with the right ventricle. Moreover, most had a favorable prognosis and were rarely associated with hemodynamic disorder. In contrast, the present report describes a case with a progressive coronary artery fistula that drained into the pulmonary artery in a Japanese male who underwent size-mismatch orthotopic cardiac transplantation from a white male donor. The fistula gradually enlarged and a left-to-right shunt deteriorated over a 5-year period after transplantation. In this case, because the coronary fistula drained into the pulmonary artery, endomyocardial biopsy was not considered as a possible cause of the fistula. It is conceivable that size-mismatch heart transplantation may be associated with the development of fistula. Copyright © American Society of Artificial Internal Organs.
  • 中山 敦子, 高澤 豊, 澤城 大悟, 廣井 透雄, 深山 正久, 永井 良三
    診断と治療 99 5 729 - 734 (株)診断と治療社 2011年05月
  • Koichi Kimura, Katsu Takenaka, XiaoFang Pan, Aya Ebihara, Kansei Uno, Nobuaki Fukuda, Takahide Kohro, Hiroyuki Morita, Yutaka Yatomi, Ryozo Nagai
    JOURNAL OF CARDIOLOGY 57 3 311 - 315 2011年05月 [査読有り][通常論文]
     
    Background: Post-ischemic myocardial diastolic stunning persists for a long time after transient ischemia even after systolic function has recovered. We sought to identify coronary artery stenosis in clinical patients using strain imaging diastolic index (SI-DI) at rest. Methods: We retrospectively examined 85 patients with suspected coronary artery disease and preserved ejection fraction (EF; >50%) who underwent both echocardiography and coronary angiography. Speckle tracking strains were measured in 3 apical views and parasternal left ventricular (LV) short-axis views at the papillary muscle level. LV segments with inadequate image quality and deficit segments in the movie were excluded by the blinded observer. After strain analysis, LV segments were classified into no stenosis (<= 50%), mild stenosis (51-75%), and severe stenosis (>75%) groups on the bases of the coronary angiogram. Results: SI-DI decreased significantly in severe stenosis segments (p< 0.05, ANOVA), but none of the peak strains showed significant difference. The area under the curve for predicting severe stenosis in radial, longitudinal, and transverse SI-DI was 0.72, 0.74, and 0.80, respectively. A cut-off value of 49 for transverse SI-DI can predict LV segments with severe stenosis with sensitivity of 0.79 and specificity of 0.73. A screening cut-off value of 63 for transverse SI-DI shows sensitivity of 0.95 and specificity of 0.50. Conclusion: SI-DI at rest is a novel marker in predicting coronary stenosis even in patients with preserved EF. This index can be used to screen patients with suspected coronary artery disease in routine echocardiography and does not require stress provocation. (C) 2011 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.
  • Kensuke Tsushima, Tomoko Osawa, Hideyuki Yanai, Akira Nakajima, Akinori Takaoka, Ichiro Manabe, Yusuke Ohba, Yasushi Imai, Tadatsugu Taniguchi, Ryozo Nagai
    FASEB journal : official publication of the Federation of American Societies for Experimental Biology 25 5 1531 - 43 2011年05月 [査読有り][通常論文]
     
    Hypertension is a typical modern lifestyle-related disease that is closely associated with the development of cardiovascular disorders. Elevation of angiotensin II (ANG II) is one of several critical factors for hypertension and heart failure; however, the mechanisms underlying the ANG II-mediated pathogenesis are still poorly understood. Here, we show that ANG II-mediated cardiac fibrosis, but not hypertrophy, is regulated by interferon regulatory factor 3 (IRF3), which until now has been exclusively studied in the innate immune system. In a ANG II-infusion mouse model (3.0 mg/kg/d), we compared IRF3-deficient mice (Irf3(-/-)/Bcl2l12(-/-)) with matched wild-type (WT) controls. The development of cardiac fibrosis [3.95 ± 0.62% (WT) vs. 1.41 ± 0.46% (Irf3(-/-)/Bcl2l12(-/-)); P<0.01] and accompanied reduction in left ventricle end-diastolic dimension [2.89 ± 0.10 mm (WT) vs. 3.51 ± 0.15 mm (Irf3(-/-)/Bcl2l12(-/-)); P=0.012] are strongly suppressed in Irf3(-/-)/Bcl2l12(-/-) mice, whereas hypertrophy still develops. Further, we provide evidence for the activation of IRF3 by ANG II signaling in mouse cardiac fibroblasts. Unlike the activation of IRF3 by innate immune receptors, IRF3 activation by ANG II is unique in that it is activated through the canonical ERK signaling pathway. Thus, our present study reveals a hitherto unrecognized function of IRF3 in cardiac remodeling, providing new insight into the progression of hypertension-induced cardiac pathogenesis.
  • Naoki Kobayashi, Kohjiro Ueki, Yukiko Okazaki, Aya Iwane, Naoto Kubota, Mitsuru Ohsugi, Motoharu Awazawa, Masatoshi Kobayashi, Takayoshi Sasako, Kazuma Kaneko, Miho Suzuki, Yoshitaka Nishikawa, Kazuo Hara, Kotaro Yoshimura, Isao Koshima, Susumu Goyama, Koji Murakami, Junko Sasaki, Ryozo Nagai, Mineo Kurokawa, Takehiko Sasaki, Takashi Kadowaki
    Proceedings of the National Academy of Sciences of the United States of America 108 14 5753 - 8 2011年04月 [査読有り][通常論文]
     
    Obesity and insulin resistance, the key features of metabolic syndrome, are closely associated with a state of chronic, low-grade inflammation characterized by abnormal macrophage infiltration into adipose tissues. Although it has been reported that chemokines promote leukocyte migration by activating class IB phosphoinositide-3 kinase (PI3Kγ) in inflammatory states, little is known about the role of PI3Kγ in obesity-induced macrophage infiltration into tissues, systemic inflammation, and the development of insulin resistance. In the present study, we used murine models of both diet-induced and genetically induced obesity to examine the role of PI3Kγ in the accumulation of tissue macrophages and the development of obesity-induced insulin resistance. Mice lacking p110γ (Pik3cg(-/-)), the catalytic subunit of PI3Kγ, exhibited improved systemic insulin sensitivity with enhanced insulin signaling in the tissues of obese animals. In adipose tissues and livers of obese Pik3cg(-/-) mice, the numbers of infiltrated proinflammatory macrophages were markedly reduced, leading to suppression of inflammatory reactions in these tissues. Furthermore, bone marrow-specific deletion and pharmacological blockade of PI3Kγ also ameliorated obesity-induced macrophage infiltration and insulin resistance. These data suggest that PI3Kγ plays a crucial role in the development of both obesity-induced inflammation and systemic insulin resistance and that PI3Kγ can be a therapeutic target for type 2 diabetes.
  • Kimie Tanaka, Daisuke Nagata, Yasunobu Hirata, Yasuhiko Tabata, Ryozo Nagai, Masataka Sata
    Atherosclerosis 215 2 366 - 73 2011年04月 [査読有り][通常論文]
     
    OBJECTIVE: Accumulating evidence suggests that exaggerated formation of vasa vasorum (VV) plays an important role in the pathogenesis of atherosclerosis. However, it remains unclear whether augmented angiogenesis in the adventitia could promote hyperlipidemia-induced atherosclerotic lesion formation. METHODS AND RESULTS: First, we analyzed the time course of VV development in apolipoprotein E-deficient (ApoE-/-) mice. VV proliferation was observed only after atherosclerotic lesion formation. Next, we investigated whether forced perivascular angiogenesis could promote plaque progression. Basic fibroblast growth factor (bFGF) (100 μg/body) incorporated in acid gelatin hydrogel microspheres (AGHM) (bFGF+AGHM group, n=10), AGHM alone (AGHM group, n=7), or PBS (control group, n=8) was administered into the periaortic area of the retroperitoneal space in 10- to 11-week-old male ApoE-/- mice. At 13 weeks after the operation, lesions were significantly larger in the bFGF+AGHM group than in others (bFGF+AGHM: 3.4 ± 0.7 × 10(4)μm(2); AGHM: 0.1 ± 0.1 × 10(4)μm(2); control: 0 μm(2); p<0.0001), which was associated with increased neovascularization in the adventitia. The number of adventitial capillaries correlated with plaque size (r=0.69, p<0.0001). In the bFGF+AGHM group, an increase in the number of VV and accumulation of Mac3-positive macrophages were observed prior to atherosclerotic lesion formation. CONCLUSIONS: Our findings demonstrated that local administration of bFGF in the adventitia induced development of VV and accelerated plaque progression in ApoE-/- mice, supporting the notion that VV formation plays a crucial role in the pathogenesis of atherosclerosis.
  • Takeki Suzuki, Tsutomu Yamazaki, Satoshi Ogawa, Ryozo Nagai, Takeshi Yamashita
    JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY 57 14 E156 - E156 2011年04月 [査読有り][通常論文]
  • Tetsuya Kubota, Naoto Kubota, Hiroki Kumagai, Shinichi Yamaguchi, Hideki Kozono, Takehiro Takahashi, Mariko Inoue, Shinsuke Itoh, Iseki Takamoto, Takayoshi Sasako, Katsuyoshi Kumagai, Tomoko Kawai, Shinji Hashimoto, Tsuneo Kobayashi, Maki Sato, Kumpei Tokuyama, Satoshi Nishimura, Masaki Tsunoda, Tomohiro Ide, Koji Murakami, Tomomi Yamazaki, Osamu Ezaki, Koichi Kawamura, Hirotake Masuda, Masao Moroi, Kaoru Sugi, Yuichi Oike, Hiroaki Shimokawa, Nobuyuki Yanagihara, Masato Tsutsui, Yasuo Terauchi, Kazuyuki Tobe, Ryozo Nagai, Katsuo Kamata, Kenji Inoue, Tatsuhiko Kodama, Kohjiro Ueki, Takashi Kadowaki
    Cell metabolism 13 3 294 - 307 2011年03月 [査読有り][通常論文]
     
    In obese patients with type 2 diabetes, insulin delivery to and insulin-dependent glucose uptake by skeletal muscle are delayed and impaired. The mechanisms underlying the delay and impairment are unclear. We demonstrate that impaired insulin signaling in endothelial cells, due to reduced Irs2 expression and insulin-induced eNOS phosphorylation, causes attenuation of insulin-induced capillary recruitment and insulin delivery, which in turn reduces glucose uptake by skeletal muscle. Moreover, restoration of insulin-induced eNOS phosphorylation in endothelial cells completely reverses the reduction in capillary recruitment and insulin delivery in tissue-specific knockout mice lacking Irs2 in endothelial cells and fed a high-fat diet. As a result, glucose uptake by skeletal muscle is restored in these mice. Taken together, our results show that insulin signaling in endothelial cells plays a pivotal role in the regulation of glucose uptake by skeletal muscle. Furthermore, improving endothelial insulin signaling may serve as a therapeutic strategy for ameliorating skeletal muscle insulin resistance.
  • 冠動脈疾患患者におけるlow-density lipoprotein cholesterol減少および血圧低下の目標値を検討する試験(JCAD II試験)(A Study to Examine Lower Targets for Low-Density-Lipoprotein-Cholesterol and Blood Pressure in Coronary Artery Disease Patients (JCAD II Study))
    Nagai Ryozo, Izumi Tohru, Kurabayashi Masahiko, Daida Hiroyuki, Tojoh Taiki, Hasegawa Akira, Miyauchi Katsumi, Kohro Takahide, Yamazaki Tsutomu
    Circulation Journal 75 Suppl.I 147 - 147 2011年03月
  • 冠動脈疾患患者における生活習慣改善の頻度と影響 Japanese Coronary Artery Disease(JCAD)研究(Frequency and Impact of Lifestyle Modification in Patients with Coronary Artery Disease: The Japanese Coronary Artery Disease (JCAD) Study)
    Suzuki Takeki, Kohro Takahide, Hayashi Doubun, Yamazaki Tsutomu, Nagai Ryozo
    Circulation Journal 75 Suppl.I 31 - 31 2011年03月
  • Mrf-2/ARID5B発現はプロモーターのPPREを介してadiponectin発現レベルを制御することによりアテローム硬化や糖尿病への感受性に影響しうる(Mrf-2/ARID5B Expression May Affect Susceptibility to Atherosclerosis and Diabetes Mellitus by Regulating Adiponectin Expression Level through PPRE in the Promoter)
    Ozeki Atsuko, Watanabe Masafumi, Manabe Ichiro, Wang Guoqin, Imai Yasushi, Yamauchi Toshimasa, Hara Kazuo, Watanabe Aya, Kawarasaki Shuichi, Maemura Koji, Kadowaki Takashi, Yamazaki Tsutomu, Nagai Ryozo
    Circulation Journal 75 Suppl.I 3 - 3 2011年03月
  • 心房細動患者における年齢層別死亡率 日本人一般集団との比較(Age-stratified Mortality in Patients with Atrial Fibrillation: Comparison with Japanese General Population)
    Suzuki Shinya, Yamashita Takeshi, Otsuka Takayuki, Sagara Koichi, Uejima Tokuhisa, Oikawa Yuji, Yajima Junji, Koike Akira, Nagashima Kazuyuki, Kirigaya Hajime, Ogasawara Ken, Sawada Hitoshi, Aizawa Tadanori, Yamazaki Tsutomu, Nagai Ryozo
    Circulation Journal 75 Suppl.I 15 - 15 2011年03月
  • 日本の陳旧性心筋梗塞後の左室機能障害患者において予防的ICD療法は有用である JCAD試験のサブ解析(Prophylactic ICD Therapy is Useful in Patients With Left Ventricular Dysfunction after Old Myocardial Infarction in Japan: Subanalysis of JCAD-Study)
    Yamasaki Hiro, Kuga Keisuke, Watanabe Shigeyuki, Sekiguchi Yukio, Tada Hiroshi, Aonuma Kazutaka, Kohro Takahide, Yamazaki Tsutomu, Nagai Ryozo
    Circulation Journal 75 Suppl.I 48 - 48 2011年03月
  • Chun Hong Shao, Haley L Capek, Kaushik P Patel, Mu Wang, Kang Tang, Cyrus DeSouza, Ryoji Nagai, William Mayhan, Muthu Periasamy, Keshore R Bidasee
    Diabetes 60 3 947 - 59 2011年03月 [査読有り][通常論文]
     
    OBJECTIVE: Approximately 25% of children and adolescents with type 1 diabetes will develop diastolic dysfunction. This defect, which is characterized by an increase in time to cardiac relaxation, results in part from a reduction in the activity of the sarco(endo)plasmic reticulum Ca(2+)-ATPase (SERCA2a), the ATP-driven pump that translocates Ca(2+) from the cytoplasm to the lumen of the sarcoplasmic reticulum. To date, mechanisms responsible for SERCA2a activity loss remain incompletely characterized. RESEARCH DESIGN AND METHODS: The streptozotocin (STZ)-induced murine model of type 1 diabetes, in combination with echocardiography, high-speed video detection, confocal microscopy, ATPase and Ca(2+) uptake assays, Western blots, mass spectrometry, and site-directed mutagenesis, were used to assess whether modification by reactive carbonyl species (RCS) contributes to SERCA2a activity loss. RESULTS: After 6-7 weeks of diabetes, cardiac and myocyte relaxation times were prolonged. Total ventricular SERCA2a protein remained unchanged, but its ability to hydrolyze ATP and transport Ca(2+) was significantly reduced. Western blots and mass spectroscopic analyses revealed carbonyl adducts on select basic residues of SERCA2a. Mutating affected residues to mimic physio-chemical changes induced on them by RCS reduced SERCA2a activity. Preincubating with the RCS, methylglyoxal (MGO) likewise reduced SERCA2a activity. Mutating an impacted residue to chemically inert glutamine did not alter SERCA2a activity, but it blunted MGO's effect. Treating STZ-induced diabetic animals with the RCS scavenger, pyridoxamine, blunted SERCA2a activity loss and minimized diastolic dysfunction. CONCLUSIONS: These data identify carbonylation as a novel mechanism that contributes to SERCA2a activity loss and diastolic dysfunction during type 1 diabetes.
  • Jun-ichi Suzuki, Masahito Ogawa, Susumu Muto, Akiko Itai, Mitsuaki Isobe, Yasunobu Hirata, Ryozo Nagai
    Expert opinion on investigational drugs 20 3 395 - 405 2011年03月 [査読有り][通常論文]
     
    INTRODUCTION: NF-kB is a key regulator of inflammation and immunity in cancer development. The IkB kinase (IKK) is a multisubunit complex containing catalytic subunits termed IKK-α, -β and -γ. It is well known that many pro-inflammatory stimuli require the IKK-β subunit for NF-kB activation. AREAS COVERED: NF-kB affects the progression of inflammation-related diseases,such as myocardial ischemia, bronchial asthma, arthritis, cancer and other diseases. We review the characteristics and effects of these inhibitors on inflammatory and other diseases. EXPERT OPINION: Various synthesized IKK inhibitors have been developed and they will be used clinically in the near future.
  • Pham Bao Ngoc, Jun-Ichi Suzuki, Masahito Ogawa, Keiichi Hishikari, Kiyoshi Takayama, Yasunobu Hirata, Ryozo Nagai, Mitsuaki Isobe
    Journal of cardiovascular pharmacology 57 3 365 - 72 2011年03月 [査読有り][通常論文]
     
    Prostaglandins (PG) and their specific receptors for E type PG (EP) play an important role in inflammatory diseases. Although myocarditis results in inflammation of the heart, roles of PG and EP in its pathophysiology is still controversial. To clarify the role of PG and EP on the progression of myocarditis, we used an experimental autoimmune myocarditis model. A selective EP4 (EP4RAG) agonist was administered into both early (Day 0 to 21) and late (Day 14 to 21) -treated groups and the animals were killed on Day 21. We found that improved cardiac function was detected in the EP4RAG-treated groups in comparison to the untreated group. The infiltration area ratio in the early-treated (16.6% ± 4.6%) group was lower than those in the untreated group (32.1% ± 3.5%) (P < 0.05). The fibrosis area ratios in the early-treated (19.2% ± 6.3%) and the late-treated groups (24.4% ± 5.1%) were lower than those in the untreated group (37.4% ± 2.6%), respectively (P < 0.05). Moreover, we found that EP4RAG decreased T-cell proliferation and monocyte chemoattractant protein-1 production in vitro. We concluded that a selective EP4 agonist inactivates T-cells, which turns out to moderate the progression of experimental autoimmune myocarditis. Therefore, EP4 can be an effective target for myocarditis treatment.
  • Jun-Ichi Suzuki, Masahito Ogawa, Susumu Muto, Akiko Itai, Yasunobu Hirata, Mitsuaki Isobe, Ryozo Nagai
    Expert opinion on investigational drugs 20 2 255 - 64 2011年02月 [査読有り][通常論文]
     
    INTRODUCTION: plasminogen activator inhibitor-1 (PAI-1) is critical in thrombus formation and inflammation. Although these are essential pathological features of cardiovascular diseases, the effects of PAI-1 inhibition against the development of cardiovascular remodeling have not been well studied. AREAS COVERED: the review explores the therapeutic value of PAI-1 in the progression of various cardiovascular diseases. To date, the authors have reported that a novel PAI-1 inhibitor suppressed the development of experimental autoimmune myocarditis, vascular remodeling after arterial injury, and heart transplant rejection using rodent models. Pathologically, the PAI-1 inhibitor improved histological remodeling of myocardium and arteries with suppression of inflammation and thrombus formation. EXPERT OPINION: PAI-1 inhibitors appear to exhibit potent effects on the prevention of adverse tissue remodeling. However, PAI-1 is a multifunctional protein and more research is needed to further elucidate the association between PAI-1 expression and cardiovascular disease.
  • Masao Takahashi, Takashi Shimizu, Tsukasa Inajima, Yumiko Hosoya, Norifumi Takeda, Nobukazu Ishizaka, Hiroshi Yamashita, Yasunobu Hirata, Ryozo Nagai
    The American journal of the medical sciences 341 2 166 - 9 2011年02月 [査読有り][通常論文]
     
    Periarteritis, including periaortitis, is a systemic disorder characterized by an excessive fibroinflammatory reaction that can result in the compromise of great vessels and periarterial/periaortic structures. Recent studies have suggested that IgG4-related inflammation may play a role in chronic periaortitis. These pathologic conditions might represent a systemic disorder with fibrotic reaction rather than local inflammation. In this report, the authors describe a case of a 31-year-old man with marked periaortic fibrous thickening localized to the aortic arch, which was histologically and serologically proven to be IgG4 related. Positron emission tomography showed increased ¹⁸F-fluorodeoxyglucose uptake at this region. Histologic examination revealed infiltration of lymphoplasmacytes and marked fibrosis with numerous IgG4-positive plasma cells. The serum concentration of IgG4 was 263 mg/dL. The size of the periaortic mass and ¹⁸F-fluorodeoxyglucose uptake at this region markedly decreased under corticosteroid therapy. This case suggests that IgG4-related periarteritis can also occur as a solitary focus in the cardiovascular system.
  • Masahito Ogawa, Jun-ichi Suzuki, Yoichi Yamaguchi, Susumu Muto, Akiko Itai, Yasunobu Hirata, Mitsuaki Isobe, Ryozo Nagai
    Transplantation 91 1 21 - 6 2011年01月 [査読有り][通常論文]
     
    BACKGROUND: Acute rejection and graft arterial disease (GAD) in cardiac transplantation limit the long-term survival of recipients; these processes are enhanced by inflammation and thrombus formation. Plasminogen activator inhibitor (PAI)-1 is critical in the inflammation and thrombus formation. However, little is known about the effect of PAI-1 in heart transplantation. Thus, the objective was to clarify the role of PAI-1 in the progression of cardiac rejection. METHODS: Murine hearts were heterotopically transplanted using major mismatch combinations for evaluation of acute rejection and class II mismatch combinations for the GAD. We administered the specific PAI-1 inhibitor (IMD-1622) into murine recipients after cardiac allografts. RESULTS: Nontreated allografts of the major mismatch group were acutely rejected, whereas the PAI-1 inhibitor prolonged their survival. Although severe cell infiltration and intimal thickening with enhancement of inflammatory factors were observed in untreated allografts of class II mismatch group on day 60, the PAI-1 inhibitor attenuated these changes. CONCLUSION: The PAI-1 inhibitor is potent for the suppression of both acute rejection and GAD.
  • 杉山 裕章, 今井 靖, 鈴木 健樹, 永井 良三
    心電図 31 2 158 - 164 The Japanese Society of Electrocardiology 2011年 
    【背景】音声認識システムを用いた文字入力の有用性は,すでに放射線画像診断分野を中心に示されており,電子カルテなどにも応用されているが,循環器分野における意義は不明である.【目的】循環器検査の1例として,ホルター心電図の判読結果に基づくレポート作成における音声入力の有用性を検討する.【方法】ホルター心電図判読レポートを電子ファイルとして作成した278症例(年齢65±16歳,男性137例)で検討した.レポートは,キーボード入力(KB群,139例)または音声認識ソフトウェア(AmiVoice(R))を用いた音声入力(AV群,139例)で作成し,両群間でその所要時間などを比較した.各レポートには有意所見数に応じたレベルを付帯し,レベル別での解析も行った.【結果】両群間で年齢・男女比やレポート文字数およびレベル分布に有意差は認められなかった.所要時間はKB群に比してAV群で有意に短く(883秒vs. 764秒,p<0.001),同傾向はレポートのレベルに関係なく認められた.【結語】ホルター心電図判読レポート作成において,時間効率の観点から音声認識システムは有用である.
  • 稲葉 俊郎, 牧 尚孝, 志賀 太郎, 波多野 将, 八尾 厚史, 絹川 弘一郎, 平田 恭信, 永井 良三
    心臓 43 7 942 - 942 Japan Heart Foundation 2011年
  • Jun-ichi Suzuki, Masahito Ogawa, Ryo Watanabe, Kiyoshi Takayama, Yasunobu Hirata, Ryozo Nagai, Mitsuaki Isobe
    International heart journal 52 5 266 - 9 2011年 [査読有り][通常論文]
     
    Prostaglandin E2 (PGE(2)) is produced in inflammatory responses and regulates a variety of immunological reactions through 4 different receptor subtypes; EP1, 2, 3 and 4. However, the precise role of each receptor in cardiovascular disease has not yet been elucidated. Enhanced expression of some EPs has been observed in clinical and experimental cardiovascular diseases. EP agonists have been developed to clarify the role of each receptor. Recently, we developed a novel selective agonist to examine the effects of EP4 on cardiac transplantation, myocardial ischemia, and myocarditis. Of note, a selective EP4 agonist attenuated inflammatory cytokines and chemokines via attenuation of macrophage activation in inflammatory heart diseases. In this review article, we discuss the effects of PGE(2) receptor agonists on the development of cardiovascular diseases.
  • Yumiko Oishi, Ichiro Manabe, Ryozo Nagai
    Nihon rinsho. Japanese journal of clinical medicine 69 Suppl 1 264 - 8 2011年01月 [査読有り][通常論文]
  • Yasushi Imai, Katsuhito Fujiu, Kazuo Asada, Hiroaki Sugiyama, Toshiya Kojima, Takeki Suzuki, Taro Kariya, Yasunobu Hirata, Ryozo Nagai
    journal of arrhythmia 27 4 223  2011年 [査読有り][通常論文]
     
    It is well known that disasters have great impact on the onset and frequency of arrhythmia in the patients with heart disease. On March 11 we experienced the unexpected the huge earthquake and tsunami waves. Moreover, the following Fukushima nuclear power plant accident caused severe anxiety to radiation exposure. These tremendous disasters caused strong mental as well as physical stress on the people living in not only the disaster area but also surrounding districts including Tokyo.To evaluate the impact of these disasters on the cardiovascular events, we compared arrhythmic events in the patients with pacemaker or ICD implanted in the University of Tokyo Hospital. Most of the patients had little events before and also after the earthquake, resulting in no significant difference. However, when we focused on the patients who had experienced relatively frequent arrhythmia before the earthquake, tachyarrhythmia events and AF burden were increased after the earthquake in the subset of our study population. Therefore, the strong stress has serious impact on arrhythmic events, which can at least partially contribute to the increase of major cardiovascular events. © 2011, Japanese Heart Rhythm Society. All rights reserved.
  • Alan S Maisel, Kazuwa Nakao, Piotr Ponikowski, W Frank Peacock, Michihiro Yoshimura, Toru Suzuki, Takayoshi Tsutamoto, Gerasimos S Filippatos, Yoshihiko Saito, Yoshihiko Seino, Naoto Minamino, Yasunobu Hirata, Masashi Mukoyama, Toshio Nishikimi, Ryozo Nagai
    International heart journal 52 5 253 - 65 2011年 [査読有り][通常論文]
  • Tomofumi Tanaka, Kenichi Ikeda, Yumiko Yamamoto, Haruko Iida, Hironobu Kikuchi, Toshihiro Morita, Tatsuya Yamasoba, Ryozo Nagai, Toshiaki Nakajima
    International heart journal 52 3 185 - 93 2011年 [査読有り][通常論文]
     
    Serum amyloid A (SAA), an acute-phase protein, and lysophosphatidylcholine (LPC), an oxidized LDL component, contribute to the physiological processes of atherosclerosis and cardiovascular disease. However, the effects of SAA/LPC on human coronary artery smooth muscle cells (hCASMCs) have not been fully investigated. Therefore, we examined the effects of SAA/LPC on Ca(2+)/Mg(2+) mobilization and its underlying mechanisms in hCASMCs. Intracellular Ca(2+)/Mg(2+) concentration ([Ca(2+)](i) / [Mg(2+)](i)) was measured with fura-2 AM/mag-fura-2 AM. Conventional RT-PCR analysis was also performed. Both SAA and LPC increased [Ca(2+)](i) by Ca(2+) entry. The SAA-induced Ca(2+) entry was inhibited by Gd(3+), SKF96365, and 2-aminoethoxydiphenyl borate (2-APB), a nonselective transient receptor potential (TRP) channel blocker, but not nifedipine. The LPC-induced Ca(2+) entry was blocked by Gd(3+), but not nifedipine, SKF96365 and 2-APB. U-73122 and PTX prevented the activation of SAA-, but not LPC-induced Ca(2+) influx. LPC, but not SAA, increased [Mg(2+)](i) as well as [Ca(2+)](i). The RT-PCR analysis revealed the expression of TRPC1/4, TRPV1/2/4, and TRPM7/8 mRNA. These results suggest that SAA/LPC activate Ca(2+) influx in hCASMCs; SAA activates it via PTX-sensitive G-protein, PLC and TRPC pathways, while LPC activates it independently of these pathways, where TRPM7 may be partly involved. Thus, TRP protein appears to be a target molecule of Ca(2+) signaling in hCASMCs elicited by SAA/LPC, which may play roles in coronary muscle dysfunction under pathophysiological and inflammatory conditions such as atherosclerosis.
  • 循環器の生物学 心臓線維芽細胞による心筋の増殖・肥大制御
    真鍋 一郎, 武田 憲文, 永井 良三
    Annual Review循環器 2011 23 - 26 (株)中外医学社 2011年01月 [査読有り][通常論文]
     
    心筋を構成する細胞の中で,数が最も多いのは心臓線維芽細胞である.心臓線維芽細胞は単に線維化に寄与するだけでなく,心筋肥大や負荷への適応応答,また心臓の発生に必須の役割を果たす.心臓の適応応答や病態の発症において,心臓線維芽細胞と心筋細胞は,パラクライン因子等を介して密接に相互作用する.今後,心疾患の理解のために,心臓線維芽細胞を初めとする心筋間質に存在する細胞と,心筋細胞の相互作用の分子機構の解明が求められる.また,心筋細胞と間質細胞の相互作用は,新たな治療標的を与える可能性がある.(著者抄録)
  • Masayasu Ikutomi, Takayoshi Matsumura, Hiroshi Iwata, Go Nishimura, Nobukazu Ishizaka, Yasunobu Hirata, Minoru Ono, Ryozo Nagai
    Cardiology 120 1 22 - 6 2011年 [査読有り][通常論文]
     
    Immunoglobulin G4 (IgG4)-related systemic disease was first recognized as a clinicopathological entity about 10 years ago, and since then, it has attracted growing attention. It is an autoimmune disease which affects multiple organs including the pancreas, bile duct, salivary glands and retroperitoneum. Further, it was recently reported that it can be manifested as periarteritis, often as inflammatory abdominal aortic aneurysm. We describe the case of a 75-year-old man with autoimmune pancreatitis and parotitis who presented with angina. The serum concentration of IgG4 was significantly increased at 2,510 mg/dl. Coronary angiography showed multiple stenotic lesions and pronounced dilatation of the right coronary artery. Cardiac computed tomography disclosed increased wall thickness of the coronary arteries and focal tumorous lesions surrounding the right coronary artery. Treatment with steroids proved only marginally effective and he underwent surgical resection of the aneurysm and coronary artery bypass grafting. The diagnosis of IgG4-related systemic disease was confirmed by histological examination of the resected mass, which showed a massive infiltration of IgG4-positive plasma cells. This case emphasizes the importance of considering the diagnosis in any patient with abnormally increased wall thickness or ectatic lesions in the coronary arteries.
  • Dai Kawashima, Takayuki Ohno, Osamu Kinoshita, Noboru Motomura, Arihiro Kiyosue, Hideo Fujita, Jiro Ando, Kazuyoshi Ohtomo, Takashi Shigeeda, Satoshi Kato, Takashi Kadowaki, Ryozo Nagai, Shinichi Takamoto, Minoru Ono
    Circulation journal : official journal of the Japanese Circulation Society 75 2 329 - 35 2011年 [査読有り][通常論文]
     
    BACKGROUND: In patients with diabetic retinopathy (DR), vitreous hemorrhage (VH) is a common complication that threatens visual acuity and hence, quality of life. A considerable number of DR patients at risk of VH require coronary revascularization, but little is known about the prevalence of VH after coronary revascularization. METHODS AND RESULTS: This study investigated 151 patients with DR who were followed up by ophthalmologists between April 2004 and September 2008, and underwent coronary revascularization (coronary artery bypass surgery n=36 or drug-eluting stent implantation n=115). At the time of coronary revascularization 56 had non-proliferative DR (NPDR) and 95 had proliferative DR (PDR). During an average follow-up of 531 days after revascularization, VH occurred in 24 (15.9%) patients, 18 (11.9%) of whom experienced VH within 6 months of the procedure. In VH patients, PDR rather than NPDR predominated as the background to VH (21 vs. 3, respectively). The 1-year prevalence of VH was higher in patients with PDR than in those with NPDR (22.0% vs. 1.9%, P=0.0055). CONCLUSIONS: VH is not a rare complication following coronary revascularization among patients with DR, especially in those with PDR. Thus, in terms of maintaining quality of life, VH after coronary revascularization needs further attention in these patients.
  • Masaru Hatano, Atsushi Yao, Koichiro Kinugawa, Yasunobu Hirata, Ryozo Nagai
    International heart journal 52 4 233 - 9 2011年 [査読有り][通常論文]
     
    The chronic use of bosentan has been reported to reduce the plasma concentration of sildenafil. However, it remains unclear how sildenafil exerts the effect at reduced concentrations in pulmonary arterial hypertension (PAH) patients chronically treated with bosentan.We examined the hemodynamic effects of sildenafil (50 mg) in 8 Japanese patients with PAH, and simultaneously measured the plasma concentration of sildenafil ([Sil]) and its major metabolite, desmethylsildenafil ([Des]).The overall effects of sildenafil were 12.4% decrease in mean pulmonary arterial pressure, 19.9% increase in cardiac index (CI), and 25% reduction in derived pulmonary vascular resistance (PVR). When the patients were divided into two groups, a group with bosentan pretreatment [BOS (+), n = 4] and a group without bosentan pretreatment [BOS (-), n = 4], both [Sil] and [Des] were lower at the peak concentration (C(max)) and the area under the plasma concentration versus time curve (AUC(0-6h)), and the time to reach C(max) was longer in BOS (+), although only the difference in AUC(0-6h) of [Des] reached statistical significance (P = 0.02). In spite of lower concentration, the effect of sildenafil on CI was maintained in the BOS (+) group, while the decrease in PVR was less marked.Sildenafil acutely dilated the pulmonary artery and increased CI in the PAH patients. These effects were still observed or maintained in the PAH patients chronically treated with bosentan, even when [Sil] was reduced.
  • Kazuaki Matsumoto, Masahito Ogawa, Jun-ichi Suzuki, Yasunobu Hirata, Ryozo Nagai, Mitsuaki Isobe
    International heart journal 52 6 382 - 7 2011年 [査読有り][通常論文]
     
    Downregulation of CD4+CD25+ regulatory T lymphocytes (Treg) has been found in local atherosclerotic lesions and in patients with myocardial infarction (MI). However, the roles of Treg in MI and the following inflammatory response have not yet been well elucidated. Therefore, we hypothesized that adoptive transfer of Treg could attenuate the postinfarction inflammatory response protecting from adverse remodeling, and we attempted to elucidate the mechanism of delayed heart failure after MI. To clarify the role of Treg in MI, we used a murine MI model and administered a single intravenous injection of Treg (1 × 10(5)) (treatment, n = 6) or saline (control, n = 7) and sacrificed the mice on day 14. Echocardiograms revealed that Treg improved LV contraction after MI. Histopathology also showed that Treg negated MI-induced LV remodeling. RT-PCR demonstrated that the mRNA levels of IFN-gamma in hearts were lower and Foxp3 in spleens were higher in the treatment group than in the control group. We observed that adoptive Treg transfer could attenuate MI-induced cardiac remodeling through the IFN-gamma and Foxp3 alteration.
  • Ryo Watanabe, Takuya Nakajima, Masahito Ogawa, Jun-ichi Suzuki, Susumu Muto, Akiko Itai, Yasunobu Hirata, Ryozo Nagai, Mitsuaki Isobe
    International heart journal 52 6 388 - 92 2011年 [査読有り][通常論文]
     
    Plasminogen activator inhibitor-1 (PAI-1) contributes to cardiac ventricular remodeling because migration of inflammatory cells and attenuation of extracellular matrix degradation are caused by plasmin and matrix metalloproteinase. However, the roles of PAI-1 in myocardial ischemia reperfusion (I/R) injury and the following inflammatory response have not yet been well elucidated. To clarify the role of PAI-1 in myocardial I/R injury, we used a specific PAI-1 inhibitor (IMD-1622) in a rat model. The left anterior descending coronary artery was ligated and reperfusion was performed by loosening the suture after 30 minutes of arterial occlusion. A single administration of IMD-1622 (20 mg/kg) or vehicle was given intraperitoneally and then the rats were sacrificed on day 1 or day 14 after I/R. Blood pressure, echocardiograms, histopathology, and molecular examination were performed. The examinations revealed that PAI-1 inhibitor showed limited effects on cardiac dysfunction and ventricular remodeling after I/R. We conclude that the pharmacological inhibition of PAI-1 may not affect ventricular remodeling after myocardial I/R injury.
  • Eriko Hasumi, Hiroshi Iwata, Kan Saito, Katsuhito Fujiu, Jiro Ando, Yasushi Imai, Hideo Fujita, Yasunobu Hirata, Ryozo Nagai
    International heart journal 52 4 240 - 2 2011年 [査読有り][通常論文]
     
    Procedure-related coronary dissection is associated with an increased risk of major adverse cardiovascular events after percutaneous coronary intervention (PCI). In most patients with such an iatrogenic complication, further PCI or bypass surgery aimed at complete revascularization is performed. Moreover, conventional coronary angiography has been used as a standard modality in the follow-up of such patients. The present report describes a 70 year old female patient who was complicated by catheter-related extensive coronary dissection in the right coronary artery (RCA) when treated for an acute myocardial infarction. Although RCA flow was insufficient, we decided against revascularization and followed her medically without additional revascularization procedures. Her clinical course had been uneventful for 4 years. However, symptoms of effort angina developed and re-examinations were performed at approximately 5 years after the myocardial infarction. Although conventional coronary angiography failed to show the culprit lesion responsible for the angina symptoms, the superior spatial resolution of the coronary CT angiography clearly identified significant progression of the stenotic lesion in the true lumen of the dissected RCA. Thus, coronary CT angiography might be considered as a possible first-line follow-up modality in patients with procedure-related coronary dissection.
  • Tetsuya Saito, Masafumi Watanabe, Toshiya Kojima, Takayoshi Matsumura, Hideo Fujita, Arihiro Kiyosue, Masao Takahashi, Norihiko Takeda, Koji Maemura, Hiroshi Yamashita, Yasunobu Hirata, Shuhei Komatsu, Kuni Ohtomo, Ryozo Nagai
    International heart journal 52 5 327 - 30 2011年 [査読有り][通常論文]
     
    Interrupted inferior vena cava (IVC) with azygos continuation is a rare congenital anomaly, and is frequently associated with other cardiovascular malformations and situs anomalies, such as left isomerism. These patients usually develop deep vein thrombosis (DVT), and asymptomatic patients above 60 years of age are very rare. Here we report a case of interrupted IVC which we diagnosed in a 72-year-old woman. She was admitted to our hospital suffering from heart failure and supraventricular tachycardia. Echocardiography detected secundum atrial septal defect (ASD). An abnormal paravertebral pleural line on the chest X-rays indicated the existence of venous anomaly. Anatomical images obtained by Multidetector Computed Tomography (MDCT) helped us to successfully perform right heart catheterization procedures through azygos continuation including blood sampling from pulmonary veins. Even in elderly patients, a careful examination of chest X-rays can indicate undiagnosed venous anomalies; thus, it is critically important before planning surgical or interventional procedures.
  • Masaru Hatano, Koichiro Kinugawa, Taro Shiga, Naoko Kato, Miyoko Endo, Motoyuki Hisagi, Takashi Nishimura, Atsushi Yao, Yasunobu Hirata, Shunei Kyo, Minoru Ono, Ryozo Nagai
    Circulation journal : official journal of the Japanese Circulation Society 75 5 1147 - 55 2011年 [査読有り][通常論文]
     
    BACKGROUND: Postoperative development of aortic insufficiency (AI) after implantation of left ventricular assist devices (LVADs) has recently been recognized, but the devices in the previous reports have been limited to the HeartMate I or II. The purposes of this study were to determine whether AI develops with other types of LVADs and to elucidate the factors associated with the development of AI. METHODS AND RESULTS: Thirty-seven patients receiving LVADs without evident abnormalities in native aortic valves were enrolled (pulsatile flow LVAD [TOYOBO]: 76%, continuous flow LVAD [EVAHEART, DuraHeart, Jarvik2000, HeartMate II]: 24%). Frequency of aortic valve opening and grade of AI were evaluated by the most recent echocardiography during LVAD support. None of the patients had more than trace AI preoperatively. During LVAD support AI >- grade 2 developed in 9 patients (24%) across all 5 types of devices. More severe grade of AI correlated with higher plasma B-type natriuretic peptide concentration (r = 0.53, P < 0.01) and with less frequent of the aortic valve (r = 0.45, P < 0.01). Multivariate analysis revealed that lower preoperative left ventricular ejection fraction and a continuous flow device type were independent risk factors for higher incidence of AI. CONCLUSIONS: AI, which is hemodynamically significant, develops after implantation of various types of LVADs. Physicians need to be more alert to the development of AI particularly with continuous flow devices.
  • Taro Shiga, Koichiro Kinugawa, Masaru Hatano, Atsushi Yao, Takashi Nishimura, Miyoko Endo, Naoko Kato, Yasunobu Hirata, Shunei Kyo, Minoru Ono, Ryozo Nagai
    Circulation journal : official journal of the Japanese Circulation Society 75 1 121 - 8 2011年 [査読有り][通常論文]
     
    BACKGROUND: In Japan, the TOYOBO left ventricular assist device (LVAD) has been commercially available for heart failure patients as of 2010, but clinical risk stratification before implantation has not been widely performed. METHODS AND RESULTS: In the present study data from 47 patients (age 38.6 ± 14.6 [SD] years, male 74.5%, non-ischemic 74.5%) implanted with a TOYOBO LVAD between November 2002 and February 2010 were analyzed. Kaplan-Meier survival analysis showed significantly higher mortality in the patients who had cardiogenic shock preoperatively (P = 0.031). Multivariate analysis revealed that the preoperative total bilirubin level (odds ratio [OR] 1.312, P < 0.001) and age (OR 1.076, P = 0.013) were independent risk factors for death. Perioperative necessity of a right ventricular assist device was also an independent risk factor for poor prognosis. CONCLUSIONS: LVAD implantation is preferable before the patient experiences hemodynamic collapse. The preoperative total bilirubin level can be used to predict prognosis after device implantation in end-stage heart failure patients.
  • Naoko Kato, Koichiro Kinugawa, Satomi Seki, Taro Shiga, Masaru Hatano, Atsushi Yao, Yasunobu Hirata, Keiko Kazuma, Ryozo Nagai
    Circulation journal : official journal of the Japanese Circulation Society 75 7 1661 - 9 2011年 [査読有り][通常論文]
     
    BACKGROUND: Little is known about health-related quality of life (QOL) in Japanese patients with heart failure. The purpose of this study was to identify factors related to QOL using a disease-specific QOL instrument, and to clarify whether QOL independently predicts clinical outcomes among Japanese patients with heart failure. METHODS AND RESULTS: A total of 114 outpatients with heart failure were enrolled (mean age 64.7 ± 15.8 years; 73.7% males). The Minnesota Living with Heart Failure Questionnaire (MLHFQ) to assess patient's QOL was used. At baseline, depressive symptoms and chronic kidney disease were significantly associated with worse QOL in multiple regression analysis. During a 2-year follow up, patients with a MLHFQ score ≥ 26, indicating worse QOL, had a higher incidence of the combined endpoint of cardiac death or hospitalization for heart failure, and a higher all-cause mortality than those with a score < 26 (25.3% vs. 7.5%, P = 0.011; 18.5% vs. 6.4%, P = 0.018; respectively). Multivariate Cox proportional hazard models demonstrated that a higher MLHFQ score was significantly associated with increased risks of cardiac events (hazard ratio, 1.02, 95% confidential interval, 1.001-1.05, P = 0.038) and of all-cause death (hazard ratio, 1.04, 95% confidential interval, 1.02-1.07, P = 0.001). CONCLUSIONS: Depressive symptoms and chronic kidney disease are major determinants of impaired QOL, and the MLHFQ score is an independent predictor of both cardiac events and death among Japanese patients with heart failure.
  • Shigeo Horinaka, Akihisa Yabe, Hiroshi Yagi, Toshihiko Ishimitsu, Tsutomu Yamazaki, Shinya Suzuki, Takahide Kohro, Ryozo Nagai
    RUSSIAN JOURNAL OF CARDIOLOGY 2 111 - 119 2011年 [査読有り][通常論文]
     
    Nicorandil has cardioprotective effects in the ischemic myocardium, mimicking ischemic preconditioning, and is thus expected to improve the prognosis of ischemic heart disease (IHD). As part of the Japanese Coronary Artery Disease (JCAD) Study, a multi-centre collaborative prospective observational study of a large cohort of coronary artery disease patients, the effect of nicorandil on outcome was examined. In total, 2,558 patients with nicorandil treatment and controls subjected to propensity score matching were eligible among 13,812 patients registered in the JCAD study. The mean follow-up interval was 2,7 years. The primary endpoint, death from all causes, was significantly lower, by 35% (hazard ratio 0,65, p=0,0008), in the nicorandil group than in the control group. There were also significant reductions in secondary endpoints, including cardiac death (56%), fatal myocardial infarction (56%), cerebral or vascular death (71%), and congestive heart failure (33%) in the nicorandil group, with no excess of deaths from other non-cardiovascular causes. Treatment with nicorandil reduced the number of deaths from all causes to a similar extent with or without treatment with sulfonylureas. The reduction in cardiovascular death with nicorandil was large in patients with IHD, which has important implications for treatment.
  • Takahide Kohro, Tsutomu Yamazaki, Tohru Izumi, Hiroyuki Daida, Masahiko Kurabayashi, Katsumi Miyauchi, Taiki Tojo, Ryozo Nagai
    Circulation journal : official journal of the Japanese Circulation Society 75 9 2062 - 70 2011年 [査読有り][通常論文]
     
    BACKGROUND: Despite mounting evidence of the benefit of intensive lowering of low-density lipoprotein-cholesterol (LDL-C) in coronary artery disease (CAD) patients, it has not been shown that intensive lowering of both LDL-C and blood pressure (BP) reduces cardiovascular events in these patients. METHODS AND RESULTS: 498 patients with hypertension and hypercholesterolemia with ≥ 75% stenosis in at least one major coronary artery, were recruited from 17 cardiovascular centers in eastern Japan. Patients were randomly assigned to conventional therapy (CT) or intensive therapy (IT). CT aimed to reduce BP to < 140/90 mm Hg and LDL-C to <100mg/dl, and IT aimed for < 120/80 mm Hg and < 80 mg/dl, respectively. The primary endpoint was a composite of all deaths, non-fatal myocardial infarction, unstable angina pectoris, coronary artery bypass graft surgery, non-fatal stroke, non-fatal major vascular disease, and peripheral artery disease. The mean follow-up period was 3.2 years. The achieved systolic BP was 126.8 mm Hg for the CT group, and 121.3 mm Hg for the IT group (P < 0.001). The achieved LDL-C was 92.1mg/dl for the CT group, and 79.6 mg/dl for the IT group (P < 0.001). We detected the primary endpoint in 18 (7.1%) patients in the CT group, and 26 (10.7%) in the IT group (hazard ratio 1.53, 95% confidence interval 0.84-2.80, P = 0.164). CONCLUSIONS: We could not show that intensively lowering both BP and LDL-C reduced cardiovascular risks in Japanese CAD patients with hypertension and hypercholesterolemia (UMIN-CTR UMIN000000571).
  • Daiju Fukuda, Soichiro Enomoto, Yoichiro Hirata, Ryozo Nagai, Masataka Sata
    BIOMEDICINE & PHARMACOTHERAPY 64 10 712 - 717 2010年12月 [査読有り][通常論文]
     
    The renin-angiotensin system (RAS) plays critical roles in the pathogenesis of atherosclerosis. Clinical studies demonstrate that pharmacological blockade of RAS with Angiotensin II type 1 receptor (AT1R) blockers (ARBs) is effective in the treatment of patients with cardiovascular diseases. Recent studies reported that telmisartan, an ARB, has a partial agonistic effect on peroxisome proliferator-activated receptor-gamma (PPAR-gamma). The role of PPAR-gamma-mediated signaling has been implicated in regulation of not only metabolic disorders but also atherosclerosis. Here, we investigated the effects of telmisartan, which is not related to AT1R blockade, using AT1aR and apolipoprotein E (ApoE) double-deficient (ApoE-/-AT1R-/-) mice in vivo. Both genetic ablation of AT1R in ApoE-deficient (ApoE-/-) mice and administration of telmisartan (10 mg/kg/day) to ApoE-/- mice for 20 weeks reduced the development of atherosclerosis (P < 0.05, respectively). Telmisartan decreased lipid deposition (P < 0.01) and increased collagen contents (P < 0.05) in plaques in ApoE-/- mice. Administration of telmisartan to ApoE-/-AT1aR-/- mice also inhibited the progression of atherosclerosis in aorta (P < 0.05) even in mice, which have no AT1aR genetically. Moreover, in these mice, telmisartan decreased macrophage accumulation and lipid deposition, and increased collagen contents in plaques in aortic root (P < 0.05, respectively), indicating stabilization of plaques. Telmisartan-treated ApoE-/-AT1aR-/- mice showed lower body weight and higher plasma high-density lipoprotein levels compared with vehicle-treated mice (P < 0.05, respectively). Telmisartan lowered systolic and diastolic blood pressure in ApoE-/-AT1aR-/- mice (P < 0.01). These results suggest that telmisartan has protective effects on the development of atherosclerosis and metabolic disorders beyond AT1R blockade in ApoE-deficient mice. (C) 2010 Elsevier Masson SAS. All rights reserved.
  • Masaki Igarashi, Jun-ichi Osuga, Hiroshi Uozaki, Motohiro Sekiya, Shuichi Nagashima, Manabu Takahashi, Satoru Takase, Mikio Takanashi, Yongxue Li, Keisuke Ohta, Masayoshi Kumagai, Makiko Nishi, Masakiyo Hosokawa, Christian Fledelius, Poul Jacobsen, Hiroaki Yagyu, Masashi Fukayama, Ryozo Nagai, Takashi Kadowaki, Ken Ohashi, Shun Ishibashi
    Circulation research 107 11 1387 - 95 2010年11月 [査読有り][通常論文]
     
    RATIONALE: Hydrolysis of intracellular cholesterol ester (CE) is the key step in the reverse cholesterol transport in macrophage foam cells. We have recently shown that neutral cholesterol ester hydrolase (Nceh)1 and hormone-sensitive lipase (Lipe) are key regulators of this process in mouse macrophages. However, it remains unknown which enzyme is critical in human macrophages and atherosclerosis. OBJECTIVE: We aimed to identify the enzyme responsible for the CE hydrolysis in human macrophages and to determine its expression in human atherosclerosis. METHODS AND RESULTS: We compared the expression of NCEH1, LIPE, and cholesterol ester hydrolase (CES1) in human monocyte-derived macrophages (HMMs) and examined the effects of inhibition or overexpression of each enzyme in the cholesterol trafficking. The pattern of expression of NCEH1 was similar to that of neutral CE hydrolase activity during the differentiation of HMMs. Overexpression of human NCEH1 increased the hydrolysis of CE, thereby stimulating cholesterol mobilization from THP-1 macrophages. Knockdown of NCEH1 specifically reduced the neutral CE hydrolase activity. Pharmacological inhibition of NCEH1 also increased the cellular CE in HMMs. In contrast, LIPE was barely detectable in HMMs, and its inhibition did not decrease neutral CE hydrolase activity. Neither overexpression nor knockdown of CES1 affected the neutral CE hydrolase activity. NCEH1 was expressed in CD68-positive macrophage foam cells of human atherosclerotic lesions. CONCLUSIONS: NCEH1 is expressed in human atheromatous lesions, where it plays a critical role in the hydrolysis of CE in human macrophage foam cells, thereby contributing to the initial part of reverse cholesterol transport in human atherosclerosis.
  • Nakajima Toshiaki, Kurano Miwa, Takano Haruhito, Iida Haruko, Fukuda Taira, Meguro Kentaro, Shiga Taro, Sagara Mina, Maemura Koji, Hirata Yasunobu, Yamasoba Tatsuya, Nagai Ryozo
    CIRCULATION 122 21 2010年11月 [査読有り][通常論文]
  • Iwata Hiroshi, Sata Masataka, Ando Jiro, Fujita Hideo, Sawaki Daigo, Takahashi Masao, Hirata Yasunobu, Nagai Ryozo
    CIRCULATION 122 21 2010年11月 [査読有り][通常論文]
  • Hiroshi Iwata, Ichiro Manabe, Katsuhito Fujiu, Tetsufumi Yamamoto, Norifumi Takeda, Kosei Eguchi, Akiko Furuya, Makoto Kuro-o, Masataka Sata, Ryozo Nagai
    Circulation 122 20 2048 - 57 2010年11月 [査読有り][通常論文]
     
    BACKGROUND: It has been proposed that bone marrow-derived cells infiltrate the neointima, where they differentiate into smooth muscle (SM) cells; however, technical limitations have hindered clear identification of the lineages of bone marrow-derived "SM cell-like" cells. METHODS AND RESULTS: Using a specific antibody against the definitive SM cell lineage marker SM myosin heavy chain (SM-MHC) and mouse lines in which reporter genes were driven by regulatory programs for either SM-MHC or SM α-actin, we demonstrated that although some bone marrow-derived cells express SM α-actin in the wire injury-induced neointima, those cells did not express SM-MHC, even 30 weeks after injury. Likewise, no SM-MHC(+) bone marrow-derived cells were found in vascular lesions in apolipoprotein E(-/-)mice or in a heart transplantation vasculopathy model. Instead, the majority of bone marrow-derived SM α-actin(+) cells were also CD115(+)CD11b(+)F4/80(+)Ly-6C(+), which is the surface phenotype of inflammatory monocytes. Moreover, adoptively transferred CD11b(+)Ly-6C(+) bone marrow cells expressed SM α-actin in the injured artery. Expression of inflammation-related genes was significantly higher in neointimal subregions rich in bone marrow-derived SM α-actin(+) cells than in other regions. CONCLUSIONS: It appears that bone marrow-derived SM α-actin(+) cells are of monocyte/macrophage lineage and are involved in vascular remodeling. It is very unlikely that these cells acquire the definitive SM cell lineage.
  • K. Kataoka, Y. Nannya, H. Iwata, S. Seo, K. Kumano, T. Takahashi, R. Nagai, M. Kurokawa
    Bone Marrow Transplantation 45 11 1631 - 1637 2010年11月 [査読有り][通常論文]
     
    Fluid retention is characteristic of veno-occlusive disease (VOD). We hypothesized that plasma brain natriuretic peptide (BNP), a neurohormone secreted in response to volume expansion, may be associated with VOD after hematopoietic stem cell transplantation (HSCT). BNP was measured before and weekly after HSCT in 46 recipients. Sixteen patients developed VOD. BNP concentrations were similar before and on day 0 in patients with and without VOD, but were significantly higher on day 7 and later in those with VOD. Patients with VOD had significantly higher peak BNP concentrations before engraftment than those without VOD (median, 634.4 versus 80.9 pg ml -1 P=0.01). Multivariate analysis showed that VOD was independently associated with BNP elevation (odds ratio, 50.1 95% CI: 5.2-478.4 P< 0.01). Landmark analysis at day 7 showed that patients with peak BNP concentration of ≥180 pg ml-1 had significantly worse 100-day survival than patients with peak BNP < 180 pg ml-1 (54 versus 91% P< 0.01). In multivariate analysis, BNP elevation before day 7 significantly predicted 100-day survival (hazard ratio 5.3 95% CI: 1.1-24.3 P=0.03). These findings suggest that plasma BNP may serve as a diagnostic and prognostic marker of VOD. © 2010 Macmillan Publishers Limited. All rights reserved.
  • Yasutomi Higashikuni, Julie Sainz, Kazuto Nakamura, Minoru Takaoka, Soichiro Enomoto, Hiroshi Iwata, Makoto Sahara, Kimie Tanaka, Nobutaka Koibuchi, Sumito Ito, Hiroyuki Kusuhara, Yuichi Sugiyama, Yasunobu Hirata, Ryozo Nagai, Masataka Sata
    Arteriosclerosis, thrombosis, and vascular biology 30 11 2128 - 35 2010年11月 [査読有り][通常論文]
     
    OBJECTIVE: To clarify the impact of breast cancer resistance protein 1 (BCRP1)/ATP-binding cassette transporter subfamily G member 2 (ABCG2) expression on cardiac repair after myocardial infarction (MI). METHODS AND RESULTS: The ATP-binding cassette transporter BCRP1/ABCG2 is expressed in various organs, including the heart, and may regulate several tissue defense mechanisms. BCRP1/ABCG2 was mainly expressed in endothelial cells of microvessels in the heart. MI was induced in 8- to 12-week-old wild-type (WT) and Bcrp1/Abcg2 knockout (KO) mice by ligating the left anterior descending artery. At 28 days after MI, the survival rate was significantly lower in KO mice than in WT mice because of cardiac rupture. Echocardiographic, hemodynamic, and histological assessments showed that ventricular remodeling was more deteriorated in KO than in WT mice. Capillary, myofibroblast, and macrophage densities in the peri-infarction area at 5 days after MI were significantly reduced in KO compared with WT mice. In vitro experiments demonstrated that inhibition of BCRP1/ABCG2 resulted in accumulation of intracellular protoporphyrin IX and impaired survival of microvascular endothelial cells under oxidative stress. Moreover, BCRP1/ABCG2 inhibition impaired migration and tube formation of endothelial cells. CONCLUSIONS: BCRP1/ABCG2 plays a pivotal role in cardiac repair after MI via modulation of microvascular endothelial cell survival and function.
  • Toshiaki Nakajima, Miwa Kurano, Takaaki Hasegawa, Haruhito Takano, Haruko Iida, Tomohiro Yasuda, Taira Fukuda, Haruhiko Madarame, Kansei Uno, Kentaro Meguro, Taro Shiga, Mina Sagara, Taiji Nagata, Koji Maemura, Yasunobu Hirata, Tatsuya Yamasoba, Ryozo Nagai
    European journal of applied physiology 110 5 905 - 13 2010年11月 [査読有り][通常論文]
     
    High-intensity exercise shares similarities with acute phase responses of inflammatory diseases. We investigated the influences of acute exercise on inflammatory markers, plasma pentraxin3 (PTX3) and serum high-sensitive C-reactive protein (CRP) (hsCRP). Nine healthy male subjects (41 ± 3 years old) participated. Each subject performed three types of exercise; ergometer exercise at 70% workload of anaerobic threshold (AT) for 30 min (70% AT exercise), peak ergometer exercise (peak EX, 20 watt increase/min until fatigue) and resistance exercises of 70% 1 RM (70% RE) until exhaustion. We measured plasma PTX3, serum hsCRP, lactate, noradrenaline (NOR), white blood cells (WBC), interleukin-6 (IL-6) and myeloperoxidase (MPO), a marker of neutrophil degranulation. The effects of exercise on intracellular PTX3 and MPO in neutrophils were also investigated, by using flow cytometry analysis. Circulating PTX3 and hsCRP significantly increased immediately after 70% RE and peak EX, while they did not increase after 70% AT exercise. The exercise-induced fold increase in PTX3 and hsCRP relative to the resting level was positively correlated with the changes in WBC, NOR, lactate and MPO. The exercise-induced fold increase in IL-6 was positively correlated with that in NOR, but not with that in PTX3 and hsCRP. Neutrophils isolated immediately after 70% RE, but not 70% AT exercise, exhibited lower mean fluorescence for PTX3 and MPO than those from pre-exercise blood. These results provide the evidence that high-intensity exercises significantly increase circulatory PTX3 as well as hsCRP. The release from peripheral neutrophils is suggested to be involved in the exercise-induced plasma PTX3 increase.
  • Arihiro Kiyosue, Yasunobu Hirata, Jiro Ando, Hideo Fujita, Toshihiro Morita, Masao Takahashi, Daisuke Nagata, Takahide Kohro, Yasushi Imai, Ryozo Nagai
    Circulation journal : official journal of the Japanese Circulation Society 74 11 2441 - 7 2010年11月 [査読有り][通常論文]
     
    BACKGROUND: This study examines whether the serum concentration of cystatin C (Cys C) correlates with the severity of coronary artery disease (CAD) and whether it provides additional information on the risk for CAD in patients without chronic kidney disease (CKD) estimated by the creatinine-based glomerular filtration rate (GFR). METHODS AND RESULTS: The relationship between serum Cys C and the severity of CAD in 526 patients was investigated. Based on GFR, patients were divided into those with and without CKD. The relationship of serum Cys C with the severity of CAD was examined. Serum Cys C was closely correlated with GFR in all cases and in CKD patients, but not in non-CKD patients. The average number of stenotic coronary arteries was significantly higher in the quartiles of higher concentration of Cys C as well as in those of GFR. In 348 patients (66%) the GFR was ≥60 ml · min(-1)·1.73 m(-2). Those patients with increased Cys C (>0.90 mg/L, 143 patients) had a significantly larger number of stenotic coronary arteries than those patients with normal Cys C. CONCLUSIONS: Among patients considered to be at low risk based on the estimated GFR using serum creatinine, those with high concentrations of Cys C could have severe CAD. Besides CKD, Cys C might serve as a marker of CAD severity.
  • Yasutomi Higashikuni, Julie Sainz, Kazuto Nakamura, Minoru Takaoka, Soichiro Enomoto, Hiroshi Iwata, Makoto Sahara, Kimie Tanaka, Nobutaka Koibuchi, Sumito Ito, Hiroyuki Kusuhara, Yuichi Sugiyama, Yasunobu Hirata, Ryozo Nagai, Masataka Sata
    Arteriosclerosis, Thrombosis, and Vascular Biology 30 11 2128 - 2135 2010年11月 [査読有り][通常論文]
     
    OBJECTIVE-: To clarify the impact of breast cancer resistance protein 1 (BCRP1)/ATP-binding cassette transporter subfamily G member 2 (ABCG2) expression on cardiac repair after myocardial infarction (MI). METHODS AND RESULTS-: The ATP-binding cassette transporter BCRP1/ABCG2 is expressed in various organs, including the heart, and may regulate several tissue defense mechanisms. BCRP1/ABCG2 was mainly expressed in endothelial cells of microvessels in the heart. MI was induced in 8- to 12-week-old wild-type (WT) and Bcrp1/Abcg2 knockout (KO) mice by ligating the left anterior descending artery. At 28 days after MI, the survival rate was significantly lower in KO mice than in WT mice because of cardiac rupture. Echocardiographic, hemodynamic, and histological assessments showed that ventricular remodeling was more deteriorated in KO than in WT mice. Capillary, myofibroblast, and macrophage densities in the peri-infarction area at 5 days after MI were significantly reduced in KO compared with WT mice. In vitro experiments demonstrated that inhibition of BCRP1/ABCG2 resulted in accumulation of intracellular protoporphyrin IX and impaired survival of microvascular endothelial cells under oxidative stress. Moreover, BCRP1/ABCG2 inhibition impaired migration and tube formation of endothelial cells. CONCLUSION-: BCRP1/ABCG2 plays a pivotal role in cardiac repair after MI via modulation of microvascular endothelial cell survival and function. © 2010 American Heart Association, Inc.
  • Masatoshi Fujita, Shigetake Sasayama, Fumio Terasaki, Satoko Mitani, Tatsuya Morimoto, Tsutomu Yamazaki, Doubun Hayashi, Takahide Kohro, Yoshihiro Okada, Ryozo Nagai
    Heart and Vessels 25 6 453 - 459 2010年11月 [査読有り][通常論文]
     
    Low-dose antihypertensive drugs in combination are prescribed frequently in clinical practice. Combination treatment is superior to monotherapy with higher doses of each drug in terms of blood pressure reduction and side effects. However, it is unclear whether combination treatment provides additional prognostic benefit beyond the blood pressure lowering effects. We assessed the usefulness of the combined treatment of a renin-angiotensin system inhibitor (RASI) and a calcium channel blocker (CCB) for all cardiovascular events in the Japanese Coronary Artery Disease (JCAD) Study population. In the JCAD Study, which is an observational and non-randomized trial, 13,812 patients with angiographically shown narrowing > 50% in ≥1 of 3 major coronary arteries were followed up for a mean of 2.7 years. The primary endpoint of the study was all cardiovascular events. In the present study, baseline covariates possibly influencing the event rate were adjusted between the different treatment groups. There was no statistically significant difference in the event rate between the RASI monotherapy and combined treatment groups, although Kaplan-Meier analysis showed a 23% (p = 0.0003) relative risk reduction with an RASI monotherapy compared with the control group. In conclusion, there may be no additional benefit beyond blood pressure lowering effects in the combination of an RASI and a CCB in patients with angiographically documented CAD. © 2010 Springer.
  • Jun-ichi Suzuki, Norio Aoyama, Masahito Ogawa, Yasunobu Hirata, Yuichi Izumi, Ryozo Nagai, Mitsuaki Isobe
    Expert opinion on therapeutic targets 14 10 1023 - 7 2010年10月 [査読有り][通常論文]
     
    Periodontitis is characterized by gingival inflammation and periodontopathic bacteria generate immunological inflammatory responses. Recent epidemiological reports suggest that periodontitis is one of the key risk factors for the onset of cardiovascular diseases. Several studies reported that periodontal bacteria in cardiovascular specimens were frequently detected. We revealed that patients with acute coronary syndrome showed significantly higher serum IgG titers to a strain of periodontopathic bacteria compared with patients with chronic coronary disease. Periodontopathic bacteria were also present in a high percentage of specimens of diseased arteries from patients with Buerger disease or abdominal aortic aneurysm. Although periodontopathic bacteria may play a role in the development of cardiovascular diseases, the influence of these bacteria on the disease has not yet been proven. In this article, we review the relationship between periodontopathic pathogens and cardiovascular diseases to conduct further clinical and experimental investigations in near future.
  • Jun-ichi Suzuki, Masahito Ogawa, Noriko Tamura, Yasuhiro Maejima, Kiyoshi Takayama, Koji Maemura, Kazuki Honda, Yasunobu Hirata, Ryozo Nagai, Mitsuaki Isobe
    Hypertension research : official journal of the Japanese Society of Hypertension 33 10 1060 - 5 2010年10月 [査読有り][通常論文]
     
    There is a deep relationship between impaired circadian rhythm and hypertension. However, the detailed mechanisms between the daily sleep-wake rhythm and cardiovascular disorders have not yet been elucidated. To clarify the mechanism, we examined salt-sensitive Dahl rats that were fed normal chow (n=10), high-salt chow (n=10) and high-salt chow with bisoprolol (n=10). Simultaneous electroencephalogram, electromyogram and locomotor activity were examined to analyze the sleep-wake state. We also examined heart rate, blood pressure and echocardiographic findings to verify the presence of hypertension. Hypertension with impaired ventricular contraction was observed in the rats with high-salt-chow consumption whereas normal-chow rats did not show these disorders. Although rats with the normal diet showed a standard daily rhythm with normal rapid eye movement (REM) sleep duration and locomotor activity, the high-salt-diet group exhibited an impaired daily rhythm with suppressed REM sleep and significant abnormal locomotor activity. Bisoprolol significantly improved the daily sleep-wake rhythm and locomotor activity. We showed that an impaired daily rhythm was closely related to the development of hypertension. Regulation of sympathetic nerve alterations may have a key role in the treatment of hypertension and circadian rhythm disorder.
  • Hong Zhan, Toru Suzuki, Kenichi Aizawa, Kiyoshi Miyagawa, Ryozo Nagai
    The Journal of biological chemistry 285 38 29662 - 70 2010年09月 [査読有り][通常論文]
     
    Oxidative stress regulates dysfunction and senescence of vascular endothelial cells. The DNA damage response and its main signaling pathway involving ataxia telangiectasia mutated (ATM) have been implicated in playing a central role in mediating the actions of oxidative stress; however, the role of the ATM signaling pathway in vascular pathogenesis has largely remained unclear. Here, we identify ATM to regulate oxidative stress-induced endothelial cell dysfunction and premature senescence. Oxidative stress induced senescence in endothelial cells through activation/phosphorylation of ATM by way of an Akt/p53/p21-mediated pathway. These actions were abrogated in cells in which ATM was knocked down by RNA interference or inhibited by specific inhibitory compounds. Furthermore, the in vivo significance of this regulatory pathway was confirmed using ATM knock-out mice in which induction of senescent endothelial cells in the aorta in a diabetic mouse model of endothelial dysfunction and senescence was attenuated in contrast to pathological changes seen in wild-type mice. Collectively, our results show that ATM through an ATM/Akt/p53/p21-dependent signaling pathway mediates an instructive role in oxidative stress-induced endothelial dysfunction and premature senescence.
  • Takuya Nakajima, Keiichi Hishikari, Masahito Ogawa, Ryo Watanabe, Jun-ichi Suzuki, Ayako Nagashima, Mayumi Masumura, Kiyoshi Takayama, Yasunobu Hirata, Ryozo Nagai, Mitsuaki Isobe
    Expert opinion on therapeutic targets 14 9 881 - 93 2010年09月 [査読有り][通常論文]
     
    BACKGROUND: MMP activity is upregulated in the heart after myocardial ischemia reperfusion, and its activation contributes to the changes in left ventricular (LV) dysfunction. A major macrolide antibiotic, clarithromycin has many biological functions including MMP regulation. However, little is known about the effect of clarithromycin in myocardial reperfusion injury via MMPs. Our objective was to clarify the role of MMPs regulated by clarithromycin in the progression of myocardial reperfusion injury. METHODS: We administered clarithromycin to rats with ischemia-reperfusion injury twice a day for 7 days before and 14 days after reperfusion. RESULTS: Clarithromycin resulted in a significant reduction of the infarction area:area at risk ratio and preserved fractional shortening ratio after 14 days of reperfusion. Immunohistochemical analysis revealed that macrophages were the primary cellular source of MMPs. Fewer macrophages were detected in the ischemic area of the hearts following ischemia reperfusion in the clarithromycin-treated group compared with the vehicle-treated group. Although ischemia-reperfusion injury resulted in LV fibrosis with increasing MMP activities, clarithromycin significantly reduced these changes. CONCLUSION: Clarithromycin is effective for attenuating myocardial ischemia-reperfusion injury by suppressing MMPs.
  • Haruhiro Toko, Hidehisa Takahashi, Yosuke Kayama, Toru Oka, Tohru Minamino, Sho Okada, Sachio Morimoto, Dong-Yun Zhan, Fumio Terasaki, Mark E. Anderson, Masashi Inoue, Atsushi Yao, Ryozo Nagai, Yasushi Kitaura, Toshiyuki Sasaguri, Issei Komuro
    Circulation 122 9 891 - 899 2010年08月 [査読有り][通常論文]
     
    Background: Dilated cardiomyopathy (DCM), characterized by dilatation and dysfunction of the left ventricle, is an important cause of heart failure. Many mutations in various genes, including cytoskeletal protein genes and contractile protein genes, have been identified in DCM patients, but the mechanisms of how such mutations lead to DCM remain unknown. Methods and Results: We established the mouse model of DCM by expressing a mutated cardiac α-actin gene, which has been reported in patients with DCM, in the heart (mActin-Tg). mActin-Tg mice showed gradual dilatation and dysfunction of the left ventricle, resulting in death by heart failure. The number of apoptotic cardiomyocytes and protein levels of p53 were increased in the hearts of mActin-Tg mice. Overexpression of Bcl-2 or downregulation of p53 decreased the number of apoptotic cardiomyocytes and improved cardiac function. This mouse model showed a decrease in myofilament calcium sensitivity and activation of calcium/calmodulin-dependent kinase IIδ (CaMKIIδ). The inhibition of CaMKIIδ prevented the increase in p53 and apoptotic cardiomyocytes and ameliorated cardiac function. CONCLUSION-: CaMKIIδ plays a critical role in the development of heart failure in part by accumulation of p53 and induction of cardiomyocyte apoptosis in the DCM mouse model. © 2010 American Heart Association, Inc.
  • Naoya Tochio, Takashi Umehara, Yoshiko Munemasa, Toru Suzuki, Shin Sato, Kengo Tsuda, Seizo Koshiba, Takanori Kigawa, Ryozo Nagai, Shigeyuki Yokoyama
    Journal of molecular biology 401 1 97 - 114 2010年08月 [査読有り][通常論文]
     
    Eukaryotic gene expression is regulated by histone deposition onto and eviction from nucleosomes, which are mediated by several chromatin-modulating factors. Among them, histone chaperones are key factors that facilitate nucleosome assembly. Acidic nuclear phosphoprotein 32B (ANP32B) belongs to the ANP32 family, which shares N-terminal leucine-rich repeats (LRRs) and a C-terminal variable anionic region. The C-terminal region functions as an inhibitor of histone acetylation, but the functional roles of the LRR domain in chromatin regulation have remained elusive. Here, we report that the LRR domain of ANP32B possesses histone chaperone activity and forms a curved structure with a parallel beta-sheet on the concave side and mostly helical elements on the convex side. Our analyses revealed that the interaction of ANP32B with the core histones H3-H4 occurs on its concave side, and both the acidic and hydrophobic residues that compose the concave surface are critical for histone binding. These results provide a structural framework for understanding the functional mechanisms of acidic histone chaperones.
  • 腹部大動脈未破裂瘤の最大短径とアンジオテンシン変換酵素阻害薬とアンジオテンシンII受容体拮抗薬との関係について
    中山 敦子, 森田 啓行, 重松 邦宏, 宮田 哲郎, 平田 恭信, 永井 良三
    日本心臓病学会誌 5 Suppl.I 385 - 385 (一社)日本心臓病学会 2010年08月
  • 腹部大動脈瘤破裂と冠動脈疾患との関連についての検討
    中山 敦子, 森田 啓行, 安東 治郎, 藤田 英雄, 重松 邦宏, 宮田 哲郎, 平田 恭信, 永井 良三
    日本心臓病学会誌 5 Suppl.I 386 - 386 (一社)日本心臓病学会 2010年08月
  • Aiko Sakamoto, Miyuki Yamamoto, Masao Takahashi, Kohsuke Ajiki, Satoshi Ota, Akimichi Murakami, Makoto Mutou, Kamon Imai, Takahiro Maruta, Hiroaki Yoshikawa, Nobukazu Ishizaka, Hiroshi Yamashita, Yasunobu Hirata, Ryozo Nagai
    Journal of cardiology cases 2 1 e41-e44 - e44 2010年08月 [査読有り][通常論文]
     
    A 65-year-old male, who had been diagnosed to have myasthenia gravis (MG) 25 years previously, was admitted to our hospital with faintness. Cardiac ultrasonography showed decreased left ventricular function. Magnetic resonance imaging depicted delayed contrast enhancement in localized regions. No significant coronary artery stenosis was found, and due to the reproducible susceptibility for sustained ventricular tachycardia, he underwent cardioverter-defibrillator implantation. Although relatively uncommon, cardiac manifestations should not be overlooked in MG patients, as they may be associated with ventricular arrhythmias and cardiac dysfunction.
  • 心血管疾患の遺伝子解析とその意義 マルファン症候群に対する遺伝子診断と包括的診療体制
    今井 靖, 小川 直美, 武田 憲文, 西村 敬史, 加藤 昌義, 森田 啓行, 縄田 寛, 竹谷 剛, 師田 哲郎, 高本 眞一, 平田 恭信, 永井 良三
    日本心臓病学会誌 5 Suppl.I 141 - 141 (一社)日本心臓病学会 2010年08月 [査読有り][通常論文]
  • Minoru Takaoka, Hiroshi Suzuki, Seiji Shioda, Kenji Sekikawa, Yoshihiko Saito, Ryozo Nagai, Masataka Sata
    ARTERIOSCLEROSIS THROMBOSIS AND VASCULAR BIOLOGY 30 8 1576 - U141 2010年08月 [査読有り][通常論文]
     
    Objective-Accumulating evidence suggests that adipose tissue not only stores energy but also secretes various bioactive substances called adipocytokines. Periadventitial fat is distributed ubiquitously around arteries throughout the body. It was reported that inflammatory changes in the periadventitial fat may have a direct role in the pathogenesis of vascular diseases accelerated by obesity. We investigated the effect of endovascular injury on the phenotype of perivascular fat. Methods and Results-Endovascular injury significantly upregulated proinflammatory adipocytokines and downregulated adiponectin within periadventitial fat tissue in models of mouse femoral artery wire injury and rat iliac artery balloon injury. Genetic disruption of tumor necrosis factor (TNF)-alpha attenuated upregulation of proinflammatory adipocytokine expression, with reduced neointimal hyperplasia after vascular injury. Local delivery of TNF-alpha to the periadventitial area enhanced inflammatory adipocytokine expression, which was associated with augmented neointimal hyperplasia in TNF-alpha-deficient mice. Conditioned medium from a coculture of 3T3-L1 and RAW264 cells stimulated vascular smooth muscle cell proliferation. An anti-TNF-alpha neutralizing antibody in the coculture abrogated the stimulating effect of the conditioned medium. Conclusion-Our findings indicate that endovascular injury induces rapid and marked changes in perivascular adipose tissue, mainly mediated by TNF-alpha. It is suggested that the phenotypic changes in perivascular adipose tissue may have a role in the pathogenesis of neointimal hyperplasia after angioplasty. (Arterioscler Thromb Vasc Biol. 2010;30:1576-1582.)
  • Masaru Hatano, Atsushi Yao, Taro Shiga, Koichiro Kinugawa, Yasunobu Hirata, Ryozo Nagai
    International heart journal 51 4 272 - 6 2010年07月 [査読有り][通常論文]
     
    Recently, platelet-derived growth factor (PDGF) has been implicated in the abnormal proliferation and migration of pulmonary artery vascular smooth muscle cells. Imatinib meslylate, a PDGF receptor antagonist, has been reported to dramatically improve pulmonary arterial hypertension (PAH) in some human cases as well as animal models. Five patients with PAH (3 scleroderma-associated PAH and 2 idiopathic/familial PAH) taking no less than 2 PAH agents were treated with low-dose imatinib (100 mg/day) for 24 weeks. Imatinib was titrated up to 200 mg/day unless major complications were observed. Before and after the treatment, right heart catheterization, cardiopulmonary exercise test, respiratory function test, and plasma concentration measurements of PDGF-BB and vascular endothelial growth factor (VEGF) were performed. Plasma PDGF-BB levels were significantly decreased after 12 weeks of treatment (P = 0.04), while VEGF did not change. Although 24 week administration of imatinib did not show a significant effect on hemodynamics and exercise capacity, 2 patients with high plasma PDGF-BB levels showed a good initial response of more than a 15% decrease in pulmonary vascular resistance. Diffusion capacity of the lung for carbon monoxide significantly improved after 12 weeks of treatment (P < 0.01) and this improvement tended to be sustained for 24 weeks (P = 0.05). Renal dysfunction was observed in 3 patients during imatinib therapy. The upregulated PDGF-BB in patients with PAH could be suppressed by imatinib treatment, and also seemed to be one of the determinant factors for its efficacy.
  • Makoto Sahara, Masataka Sata, Toshihiro Morita, Toshiaki Nakajima, Yasunobu Hirata, Ryozo Nagai
    Arteriosclerosis, thrombosis, and vascular biology 30 7 1315 - 24 2010年07月 [査読有り][通常論文]
     
    OBJECTIVE: We examined whether phosphodiesterase-5 (PDE5) inhibition can promote ischemia-induced angiogenesis. METHODS AND RESULTS: Unilateral hindlimb ischemia was generated by resecting right femoral artery in wild-type C3H/He mice, treated with either vehicle or a PDE5 inhibitor vardenafil (10 mg/kg per day). Four weeks after surgery, vardenafil significantly enhanced blood flow recovery and augmented capillary collateral formation in ischemic muscle (blood flow ratios of ischemic/nonischemic leg: 0.52+/-0.17 [vehicle] versus 0.92+/-0.09 [vardenafil], P<0.01). Vardenafil upregulated protein expression of vascular endothelial growth factor and hypoxia-inducible factor (HIF)-1 alpha in ischemic muscle and enhanced mobilization of Sca-1/Flk-1-positive endothelial progenitor cells (EPCs) in peripheral blood and bone marrow, contributing to neovascularization. Vardenafil also promoted capillary-like tube formation of human umbilical vein endothelial cells and increased the number of human blood mononuclear cell-derived EPCs in vitro. Furthermore, reporter assays showed that vardenafil and cGMP activated the transactivation activity of HIF-1 under hypoxia. These effects of vardenafil were markedly inhibited by genetic ablation of endothelial nitric oxide synthase, a soluble guanylate cyclase inhibitor, and a protein kinase G inhibitor, respectively. CONCLUSIONS: Our results suggest that PDE5 inhibition enhances ischemia-induced angiogenesis with mobilization of EPCs through a protein kinase G-dependent HIF-1/vascular endothelial growth factor pathway. PDE5 inhibition may have a therapeutic potential to treat ischemic cardiovascular diseases.
  • Atsushi Oguri, Tomofumi Tanaka, Haruko Iida, Kentarou Meguro, Haruhito Takano, Hitoshi Oonuma, Satoshi Nishimura, Toshihiro Morita, Tatsuya Yamasoba, Ryozo Nagai, Toshiaki Nakajima
    American journal of physiology. Cell physiology 298 6 C1414-23 - C1423 2010年06月 [査読有り][通常論文]
     
    Voltage-gated Ca(2+) channels (Ca(V)) are ubiquitously expressed in various cell types and play vital roles in regulation of cellular functions including proliferation. However, the molecular identities and function of Ca(V) remained unexplored in preadipocytes. Therefore, whole cell voltage-clamp technique, conventional/quantitative real-time RT-PCR, Western blot, small interfering RNA (siRNA) experiments, and immunohistochemical analysis were applied in mouse primary cultured preadipocytes as well as mouse 3T3-L1 preadipocytes. The effects of Ca(V) blockers on cell proliferation and cell cycle were also investigated. Whole cell recordings of 3T3-L1 preadipocytes showed low-threshold Ca(V), which could be inhibited by mibefradil, Ni(2+) (IC(50) of 200 muM), and NNC55-0396. Dominant expression of alpha(1G) mRNA was detected among Ca(V) transcripts (alpha(1A)-alpha(1I)), supported by expression of Ca(V)3.1 protein encoded by alpha(1G) gene, with immunohistochemical studies and Western blot analysis. siRNA targeted for alpha(1G) markedly inhibited Ca(V). Dominant expression of alpha(1G) mRNA and expression of Ca(V)3.1 protein were also observed in mouse primary cultured preadipocytes. Expression level of alpha(1G) mRNA and Ca(V)3.1 protein significantly decreased in differentiated adipocytes. Mibefradil, NNC55-0396, a selective T-type Ca(V) blocker, but not diltiazem, inhibited cell proliferation in response to serum. NNC55-0396 and siRNA targeted for alpha(1G) also prevented cell cycle entry/progression. The present study demonstrates that the Ca(V)3.1 T-type Ca(2+) channel encoded by alpha(1G) subtype is the dominant Ca(V) in mouse preadipocytes and may play a role in regulating preadipocyte proliferation, a key step in adipose tissue development.
  • Yumiko Oishi, Ichiro Manabe, Yasushi Imai, Kazuo Hara, Momoko Horikoshi, Katsuhito Fujiu, Toshihiro Tanaka, Tadanori Aizawa, Takashi Kadowaki, Ryozo Nagai
    FASEB journal : official publication of the Federation of American Societies for Experimental Biology 24 6 1780 - 8 2010年06月 [査読有り][通常論文]
     
    Krüppel-like factor 5 (KLF5) is a zinc-finger-type transcription factor that mediates the tissue remodeling in cardiovascular diseases, such as atherosclerosis, restenosis, and cardiac hypertrophy. Our previous studies have shown that KLF5 is induced by angiotensin II (AII), although the precise molecular mechanism is not yet known. Here we analyzed regulatory single nucleotide polymorphisms (SNPs) within the KLF5 locus to identify clinically relevant signaling pathways linking AII and KLF5. One SNP was located at -1282 bp and was associated with an increased risk of hypertension: subjects with the A/A and A/G genotypes at -1282 were at significantly higher risk for hypertension than those with the G/G genotype. Interestingly, a reporter construct corresponding to the -1282G genotype showed much weaker responses to AII than a construct corresponding to -1282A. Electrophoretic mobility shift, chromatin immunoprecipitation, and reporter assays collectively showed that the -1282 SNP is located within a functional myocyte enhancer factor 2 (MEF2) binding site, and that the -1282G genotype disrupts the site and reduces the AII responsiveness of the promoter. Moreover, MEF2 activation via reactive oxygen species and p38 mitogen-activated protein kinase induced KLF5 expression in response to AII, and KLF5 and MEF2 were coexpressed in coronary atherosclerotic plaques. These results suggest that a novel signaling and transcription network involving MEF2A and KLF5 plays an important role in the pathogenesis of cardiovascular diseases such as hypertension.
  • Taira Fukuda, Taketeru Maegawa, Akihiro Matsumoto, Yutaka Komatsu, Toshiaki Nakajima, Ryozo Nagai, Takashi Kawahara
    International heart journal 51 3 170 - 5 2010年05月 [査読有り][通常論文]
     
    It has been unclear how acute hypoxia at moderate altitude affects stroke volume (SV), an index of cardiac function, during exercise. The present study was conducted to reveal whether acute normobaric hypoxia might alter SV during exercise.Nine healthy male subjects performed maximal exercise testing under normobaric normoxic, and normobaric hypoxic conditions (O(2): 14.4%) in a randomized order. A novel thoracic impedance method was used to continuously measure SV and cardiac output (CO) during exercise. Acute hypoxia decreased maximal work rate (hypoxia; 247 + or - 6 [SE] versus normoxia; 267 + or - 8 W, P < 0.005) and VO(2) max (hypoxia; 2761 + or - 99 versus normoxia; 3039 + or - 133 mL/min, P < 0.005). Under hypoxic conditions, SV and CO at maximal exercise decreased (SV: hypoxia; 145 + or - 11 versus normoxia; 163 + or - 11 mL, P < 0.05, CO: hypoxia; 26.7 + or - 2.1 versus normoxia; 30.2 + or - 1.8 L/min, P < 0.05). In acute hypoxia, SV during submaximal exercise at identical work rate decreased. Furthermore, in hypoxia, 4 of 9 subjects attained their highest SV at maximal exercise, while in normoxia, 8 of 9 subjects did.Acute normobaric hypoxia attenuated the increment of SV and CO during exercise, and SV reached a plateau earlier under hypoxia than in normoxia. Cardiac function during exercise at this level of acute normobaric hypoxia might be attenuated.
  • Hiroshi Iwata, Masataka Sata, Jiro Ando, Hideo Fujita, Toshihiro Morita, Daigo Sawaki, Masao Takahashi, Yoichiro Hirata, Shuichiro Takanashi, Minoru Tabata, Yasunobu Hirata, Ryozo Nagai
    Heart (British Cardiac Society) 96 10 748 - 55 2010年05月 [査読有り][通常論文]
     
    BACKGROUND: Clinical evidence suggests that intracoronary thrombus formation is associated with a high incidence of late restenosis after successful coronary intervention in patients with myocardial infarction (MI). However, little is known about the mechanism by which intracoronary thrombi play pathological roles. METHODS AND RESULTS: We analysed the cellular constituents of 108 thrombi aspirated from coronary lesions with a thrombectomy device in 62 patients who underwent emergent coronary intervention for the treatment of acute (<24 h) or recent (24-72 h) ST-segment elevation MI (44 men, 18 women, aged 68.0+/-19.3 years). Immunohistological analysis of aspirated thrombotic materials revealed that the content of platelets, as determined by immunostaining for CD42a, had a negative correlation with the time after the onset of chest pain (correlation coefficient -0.683, p<0.01). Immunofluorescent staining for CD34 and breast cancer-resistant protein-1 (bcrp-1) detected primitive cells in intracoronary thrombi. Furthermore, the ratio of CD34-positive cells in intracoronary thrombi had a significant positive correlation with restenosis at follow-up coronary angiography (correlation coefficient 0.76, p=0.01). CONCLUSIONS: The findings of this study indicate that the early accumulation of primitive cells in platelet aggregates may play a role in neointimal growth after successful coronary intervention in patients with acute coronary syndrome.
  • Yoshinori Takeuchi, Naoya Yahagi, Yoshihiko Izumida, Makiko Nishi, Midori Kubota, Yuji Teraoka, Takashi Yamamoto, Takashi Matsuzaka, Yoshimi Nakagawa, Motohiro Sekiya, Yoko Iizuka, Ken Ohashi, Jun-ichi Osuga, Takanari Gotoda, Shun Ishibashi, Keiji Itaka, Kazunori Kataoka, Ryozo Nagai, Nobuhiro Yamada, Takashi Kadowaki, Hitoshi Shimano
    The Journal of biological chemistry 285 15 11681 - 91 2010年04月 [査読有り][通常論文]
     
    Sterol regulatory element-binding protein (SREBP)-1 is a key transcription factor for the regulation of lipogenic enzyme genes in the liver. Polyunsaturated fatty acids (PUFA) selectively suppress hepatic SREBP-1, but molecular mechanisms remain largely unknown. To gain insight into this regulation, we established in vivo reporter assays to assess the activities of Srebf1c transcription and proteolytic processing. Using these in vivo reporter assays, we showed that the primary mechanism for PUFA suppression of SREBP-1 is at the proteolytic processing level and that this suppression in turn decreases the mRNA transcription through lowering SREBP-1 binding to the SREBP-binding element on the promoter ("autoloop regulatory circuit"), although liver X receptor, an activator for Srebf1c transcription, is not involved in this regulation by PUFA. The mechanisms for PUFA suppression of SREBP-1 confirm that the autoloop regulation for transcription is crucial for the nutritional regulation of triglyceride synthesis.
  • Keiichi Hishikari, Ryo Watanabe, Masahito Ogawa, Jun-ichi Suzuki, Mayumi Masumura, Tomoko Shimizu, Kiyoshi Takayama, Yasunobu Hirata, Ryozo Nagai, Mitsuaki Isobe
    Heart (British Cardiac Society) 96 7 523 - 7 2010年04月 [査読有り][通常論文]
     
    BACKGROUND: Matrix metalloproteinase (MMP) activity is upregulated in the hearts with myocarditis, and its activation contributes to the changes in left ventricular function. A major macrolide antibiotic, clarithromycin (CAM), has many biological functions including MMP regulation. However, little is known about the effect of CAM in myocarditis via MMPs. OBJECTIVE: To clarify the role of MMPs regulated by CAM in the progression of myocarditis. Design CAM was given to experimental rats with autoimmune myocarditis (EAM) from day -7 to day 21 (early treated group, n=6) or from day 1 to day 21 (late treated group, n=6) twice a day. RESULTS: Although the non-treated rats showed blood pressure decline and impaired cardiac function, early CAM treatment prevented this progression. Pathologically, severe myocardial cell infiltration (30.5+/-4.2%) and fibrosis (32.2+/-1.1%) were detected in the non-treated group, while early CAM treatment significantly suppressed these changes (infiltration 6.5+/-0.2%, fibrosis 5.9+/-3.9%). Zymography showed that non-treated EAM resulted in enhanced ventricular activities of MMP-9, while early CAM treatment reduced the alteration. However, late CAM treatment was less effective than the early treatment. CONCLUSIONS: Early CAM treatment is effective to attenuate myocarditis by suppressing MMP-9.
  • Arihiro Kiyosue, Yasunobu Hirata, Jiro Ando, Hideo Fujita, Toshihiro Morita, Masao Takahashi, Daisuke Nagata, Takahide Kohro, Yasushi Imai, Ryozo Nagai
    Circulation journal : official journal of the Japanese Circulation Society 74 4 786 - 91 2010年04月 [査読有り][通常論文]
     
    BACKGROUND: The relationship between renal dysfunction and the severity of coronary artery disease (CAD) was examined. METHODS AND RESULTS: The severity of CAD in 572 patients was graded according to the number of stenotic coronary arteries, and the estimated glomerular filtration rate (eGFR) was monitored for 3 years. Patients were stratified into 3 eGFR groups: normal (>75 ml x min(-1) x 1.73 m(-2)), mild reduction (60-75) and chronic kidney disease (CKD: <60). There were 161 patients in the CKD group. The average number of stenotic coronary arteries was larger in the CKD group than in the other groups (normal vs mild reduction vs CKD =1.35+/-0.07 (SE) vs 1.22+/-0.08 vs 1.69+/-0.08 vessel disease (VD), P<0.001). During the 3-year follow-up, the renal function of 13.8% of the patients worsened. Those who showed more deterioration of eGFR had more severe CAD than those who did not (1.20+/-0.06 vs 1.61+/-0.06 VD, P<0.001). Multivariate analysis revealed that the severity of CAD was independently and significantly associated with the deterioration of eGFR. CONCLUSIONS: Patients with CKD had more severe CAD, which may explain the high rate of cardiovascular events in these patients. Moreover, the prognosis of renal function was poor in patients with severe CAD, and CAD was found to be an independent risk factor for worsening of renal dysfunction.
  • Jun-ichi Suzuki, Masahito Ogawa, Kiyoshi Takayama, Yoshiaki Taniyama, Ryuichi Morishita, Yasunobu Hirata, Ryozo Nagai, Mitsuaki Isobe
    Journal of the American College of Cardiology 55 9 904 - 13 2010年03月 [査読有り][通常論文]
     
    OBJECTIVES: The purpose of this study was to investigate the efficiency of small interfering ribonucleic acid (siRNA) in murine arteries. We transfected it using a nonviral ultrasound-microbubble-mediated in vivo gene delivery system. BACKGROUND: siRNA is an effective methodology to suppress gene function. The siRNA can be synthesized easily; however, a major obstacle in the use of siRNA as therapeutics is the difficulty involved in effective in vivo delivery. METHODS: To investigate the efficiency of nonviral ultrasound-microbubble-mediated in vivo siRNA delivery, we used a fluorescein-labeled siRNA, green fluorescent protein (GFP) siRNA, and intercellular adhesion molecule (ICAM)-1 siRNA in murine arteries. Murine femoral arteries were injured using flexible wires to establish arterial injury. RESULTS: The fluorescein-labeled siRNA and GFP siRNA showed that this nonviral approach could deliver siRNA into target arteries effectively without any tissue damage and systemic adverse effects. ICAM-1 siRNA transfection into murine injured arteries significantly suppressed the development of neointimal formation in comparison to those in the control group. Immunohistochemistry revealed that accumulation of T cells and adhesion molecule positive cells was observed in nontreated injured arteries, whereas siRNA suppressed accumulation. CONCLUSIONS: The nonviral ultrasound-microbubble delivery of siRNA ensures effective transfection into target arteries. ICAM-1 siRNA has the potential to suppress arterial neointimal formation. Transfection of siRNA can be beneficial for the clinical treatment of cardiovascular and other inflammatory diseases.
  • Adrenomedullinノックアウトマウスにおける炎症細胞浸潤を介した脈絡膜新生血管促進
    湯田 健太郎, 井上 達也, 上田 高志, 高橋 秀徳, 永井 良三, 柳 靖雄, 玉置 泰裕, 新家 眞
    日本眼科学会雑誌 114 臨増 311 - 311 (公財)日本眼科学会 2010年03月
  • 家庭血圧自動測定により検出される仮面高血圧とメタボリックシンドロームとの関連 根拠に基づく健康スクリーニングから(Association of Masked Hypertension and Metabolic Syndrome Detected through Automatic Home Blood Pressure Measurement: From Evidence-based Health Screening)
    Aizawa Kenichi, Suzuki Toru, Kohro Takahide, Ohike Yumiko, Seto Motoko, Suzuki Kazushi, Nagai Ryozo, Yamazaki Tsutomu
    Circulation Journal 74 Suppl.I 301 - 301 2010年03月
  • PCI施行患者の新病変形成に対する危険因子の検証(Identification of the Risk Factors for New Lesion Formation in the Patients Undergoing PCI)
    Yamaguchi Atsuko, Morita Hitoyuki, Iwata Hiroshi, Kohro Takahide, Andoh Jiro, Fujita Hideo, Imai Yasushi, Yamazaki Tsutomu, Nagai Ryozo
    Circulation Journal 74 Suppl.I 567 - 567 2010年03月
  • Tsuyoshi Shimizu, Takayuki Ohno, Jiro Ando, Hideo Fujita, Ryozo Nagai, Noboru Motomura, Minoru Ono, Shunei Kyo, Shinichi Takamoto
    Circulation journal : official journal of the Japanese Circulation Society 74 3 449 - 55 2010年03月 [査読有り][通常論文]
     
    BACKGROUND: The optimal revascularization strategy for unprotected left main coronary artery (ULMCA) disease in the era of drug-eluting stents (DES) has become more controversial between coronary artery bypass grafting (CABG) and percutaneous coronary intervention (PCI). METHODS AND RESULTS: Since April 2004, 89 patients underwent CABG, including 82 (92.1%) off-pump procedures and 63 patients underwent PCI with DES for ULMCA disease. Major adverse cardiac and cerebrovascular events (MACCE: death, acute myocardial infarction, stroke and repeat revascularization) and hospitalization costs were compared. Patients in the CABG group were likely to have multivessel disease and higher euroSCORE. The mean follow-up was 2.2+/-1.1 years in the CABG group and 1.6+/-0.8 years in the DES group (P<0.001). The overall survival rate did not differ (P=0.288) between the groups (CABG: 93.4% and DES: 91.9% at 2 years). The MACCE-free survival rate was better (P=0.033) in the CABG group (CABG: 82.2% and DES: 62.6% at 2 years). Total hospitalization costs were lower (P=0.013) in the CABG group (median: 3,225 thousand yen) than in the DES group (median: 4,192 thousand yen). CONCLUSIONS: CABG might be associated with cost-effectiveness and could be still the first revascularization strategy for ULMCA disease.
  • Nobukazu Ishizaka, Makiko Hongo, Gen Matsuzaki, Kyoko Furuta, Kan Saito, Ryota Sakurai, Aiko Sakamoto, Kazuhiko Koike, Ryozo Nagai
    HYPERTENSION RESEARCH 33 3 263 - 268 2010年03月 [査読有り][通常論文]
     
    Unfavorable lipid accumulation may occur in the kidneys in the presence of metabolic syndrome and diabetes. The aim of this study was to investigate whether excess lipids would accumulate in the kidneys of Otsuka Long-Evans Tokushima Fatty (OLETF) rats, an animal model of metabolic syndrome. From 34 weeks of age, OLETF rats were treated orally with a calcium channel blocker, benidipine (3 mg kg(-1) per day), or an AT1 receptor blocker, losartan (25 mg kg(-1) per day), for 8 weeks. Blood pressure was slightly but significantly higher in the untreated OLETF rats (149 +/- 4 mm Hg) than in Long-Evans Tokushima Otsuka (LETO) rats (136 +/- 2 mm Hg), and both losartan (135 +/- 3 mm Hg) and benidipine (138 +/-3 mm Hg) reduced blood pressure in OLETF rats to a level comparable to that in LETO rats. Tissue content of triglycerides (TG) was greater in OLETF rats than in LETO rats (6.24 +/- 3.77 and 2.85 +/- 1.32 mu g mg(-1). tissue, respectively), and both losartan and benidipine reduced these values. Histological analysis showed lipid droplets in tubular cells in which increased dihydroethidium fluorescence was present. Expression of peroxisome proliferator-activated receptor-alpha, PGC-1 alpha and uncoupling protein-2 was found to be higher in OLETF rats than in LETO rats; however, the expression of these genes was not altered by treatment with either antihypertensive drug. In contrast, both losartan and benidipine increased the amount of total and phosphorylated forms of AMP kinase and the expression of carnitine palmitoyltransferase-1 (CPT-1). In conclusion, treatment of OLETF rats with losartan and benidipine reduced the tissue content of TG, decreased the production of superoxide and regulated the expression of genes related to fatty acid oxidation such as AMP-activated protein kinase and CPT-1 in the kidneys. Hypertension Research (2010) 33, 263-268; doi:10.1038/hr.2009.224; published online 8 January 2010
  • Shigeo Horinaka, Akihisa Yabe, Hiroshi Yagi, Toshihiko Ishimitsu, Tsutomu Yamazaki, Shinya Suzuki, Takahide Kohro, Ryozo Nagai
    Circulation Journal 74 3 503 - 509 2010年03月 [査読有り][通常論文]
     
    Background: Nicorandil has cardioprotective effects in the ischemic myocardium, mimicking ischemic preconditioning, and is thus expected to improve the prognosis of ischemic heart disease (IHD). As part of the Japanese Coronary Artery Disease (JCAD) Study, a multicenter collaborative prospective observational study of a large cohort of coronary artery disease patients, the effect of nicorandil on outcome was examined. Methods and Results: In total, 2,558 patients with nicorandil treatment and controls subjected to propensity score matching were eligible among 13,812 patients registered in the JCAD study. The mean follow-up interval was 2.7 years. The primary endpoint, death from all causes, was significantly lower, by 35% (hazard ratio 0.65, P=0.0008), in the nicorandil group than in the control group. There were also significant reductions in secondary endpoints, including cardiac death (56%), fatal myocardial infarction (56%), cerebral or vascular death (71%), and congestive heart failure (33%) in the nicorandil group, with no excess of deaths from other non-cardiovascular causes. Treatment with nicorandil reduced the number of deaths from all causes to a similar extent with or without treatment with sulfonylureas. Conclusions: The reduction in cardiovascular death with nicorandil was large in patients with IHD, which has important implications for treatment.
  • 志賀 太郎, 絹川 弘一郎, 波多野 将, 舛方 葉子, 八尾 厚史, 西村 隆, 小野 稔, 許 俊鋭, 永井 良三
    移植 45 1 62 - 62 (一社)日本移植学会 2010年02月
  • Nobukazu Ishizaka, Yuko Ishizaka, Akiko Toda, Mizuki Tani, Kazuhiko Koike, Minoru Yamakado, Ryozo Nagai
    Journal of Rheumatology 37 2 410 - 416 2010年02月 [査読有り][通常論文]
     
    Objective. Studies have shown that obesity is associated with an increase in serum uric acid and few data are available on the relationship between changes in measures of obesity and changes in uric acid concentrations. We investigated the relationship among percentage changes in waist circumference (%dWC), body mass index (%dBMI), and serum uric acid (%dUA). Methods. The data of 3153 individuals [1968 men, 1185 women (536 premenopausal, 649 postmenopausal)] who underwent general health screening over a 2-year period and were not taking antihyperuricemic medication were analyzed. Results. Stepwise multiple regression analysis showed that %dBMI was associated positively with %dUA in postmenopausal women and men, and the association retained statistical significance after adjustment for changes in blood pressure and in renal function. Association between %dBMI and %dUA was not significant in premenopausal women. In men, %dWC was a predicting factor for %dUA, although it did not remain significant when %dBMI was used as a covariate in the statistical model. Multivariate logistic regression analysis showed that the odds ratio of the association between the lowest %dBMI quartile (%dBMI < -1.86) and the lowest %dUA quartile (%dUA < -7.41) was 2.04 (95% CI 1.35-3.07) in postmenopausal women and 1.46 (95% CI 1.14-1.86) in men. Conclusion. Weight loss may represent an effective nonmedical strategy for reducing serum UA levels, especially in postmenopausal women and men. Copyright © 2010. All rights reserved.
  • Masao Takahashi, Etsu Suzuki, Shigeyoshi Oba, Hiroaki Nishimatsu, Kenjiro Kimura, Tetsuo Nagano, Ryozo Nagai, Yasunobu Hirata
    American journal of physiology. Heart and circulatory physiology 298 2 H415-23 - H423 2010年02月 [査読有り][通常論文]
     
    Subcutaneous adipose tissue contains a lot of stem cells [adipose-derived stem cells (ASCs)] that can differentiate into a variety of cell lineages. In this study, we isolated ASCs from Wistar rats and examined whether ASCs would efficiently differentiate into vascular endothelial cells (ECs) in vitro. We also administered ASCs in a wire injury model of rat femoral artery and examined their effects. ASCs expressed CD29 and CD90, but not CD34, suggesting that ASCs resemble bone marrow-derived mesenchymal stem cells. When induced to differentiate into ECs with endothelial growth medium (EGM), ASCs expressed Flt-1, but not Flk-1 or mature EC markers such as CD31 and vascular endothelial cadherin. ASCs produced angiopoietin-1 when they were cultured in EGM. ASCs stimulated the migration of EC, as assessed by chemotaxis assay. When ASCs that were cultured in EGM were injected in the femoral artery, the ASCs potently and significantly inhibited neointimal formation without being integrated in the endothelial layer. EGM-treated ASCs significantly suppressed neointimal formation even when they were administered from the adventitial side. ASC administration significantly promoted endothelial repair. These results suggested that although ASCs appear to have little capacity to differentiate into mature ECs, ASCs have the potential to secrete paracrine factors that stimulate endothelial repair. Our results also suggested that ASCs inhibited neointimal formation via their paracrine effect of stimulation of EC migration in situ rather than the direct integration into the endothelial layer.
  • Jun-ichi Suzuki, Mitsuaki Isobe, Ryuichi Morishita, Ryozo Nagai
    CIRCULATION JOURNAL 74 2 233 - 239 2010年02月 [査読有り][通常論文]
     
    Although 85,000 heart transplantations have been performed worldwide, coronary allograft vasculopathy (CAV), which is a phenomenon of chronic rejection, is still a serious problem. Because CAV involves all the allograft arteries, angioplasty, stenting or bypass grafting are not practical treatment options. Therefore, CAV is the biggest long-term limitation in cardiac allograft recipients. Although the cause of CAV is mostly immunologic, non-immune pathways also contribute to its development. Several cytokines, chemokines and adhesion molecules play a critical role in the process. Cell adhesion, migration and proliferation of bone marrow progenitor and and other cells are involved in its development. Although there is not an established clinical strategy for preventing or treating CAV, recent investigations have provided some promising methodologies. Progress in DNA technology, such as antisense oligodeoxynucleotides (ODNs) to regulate the transcription of disease-related genes, has an important role in its therapeutic applications. Antisense ODN transfection preventing CAV in experimental cardiac allografts has been reported for the first time. The ODN strategy has not only been useful in the experimental studies, but is also a novel clinical strategy for gene therapy. The pathological and immunological characteristics of CAV and some promising methodologies for prevention of the disease are reviewed. (Circ J 2010; 74: 233-239)
  • Masaki Igarashi, Jun-Ichi Osuga, Masashi Isshiki, Motohiro Sekiya, Hiroaki Okazaki, Satoru Takase, Mikio Takanashi, Keisuke Ohta, Masayoshi Kumagai, Makiko Nishi, Toshiro Fujita, Ryozo Nagai, Takashi Kadowaki, Shun Ishibashi
    Journal of lipid research 51 2 274 - 85 2010年02月 [査読有り][通常論文]
     
    Neutral cholesterol ester hydrolase (NCEH) accounts for a large part of the nCEH activity in macrophage foam cells, a hallmark of atherosclerosis, but its subcellular localization and structure-function relationship are unknown. Here, we determined subcellular localization, glycosylation, and nCEH activity of a series of NCEH mutants expressed in macrophages. NCEH is a single-membrane-spanning type II membrane protein comprising three domains: N-terminal, catalytic, and lipid-binding domains. The N-terminal domain serves as a type II signal anchor sequence to recruit NCEH to the endoplasmic reticulum (ER) with its catalytic domain within the lumen. All of the putative N-linked glycosylation sites (Asn(270), Asn(367), and Asn(389)) of NCEH are glycosylated. Glycosylation at Asn(270), which is located closest to the catalytic serine motif, is important for the enzymatic activity. Cholesterol loading by incubation with acetyl-LDL does not change the ER localization of NCEH. In conclusion, NCEH is targeted to the ER of macrophages, where it hydrolyzes CE to deliver cholesterol for efflux out of the cells.
  • 藤田 英子, 佐原 真, 杉山 裕章, 安東 治郎, 藤田 英雄, 森田 敏宏, 平田 恭信, 永井 良三
    心臓 42 1 49 - 59 公益財団法人 日本心臓財団 2010年 
    今回われわれは, 両側腎動脈狭窄症 (RAS) による再発性の心不全と急性腎不全, あるいは治療抵抗性高血圧をきたした2症例を経験した.
    症例1: 72歳, 女性. 僧帽弁置換術後の低左心機能症例で心不全入院を繰り返していた. 今回心不全加療中に急性腎前性腎不全を発症して血液透析導入となり, その後両側RASの存在が判明した. 両腎とも8.5cm大と軽度萎縮していたが, 透析から離脱困難だったこともあり腎機能と血行動態の改善を目指してステント留置による経皮的腎動脈形成術 (PTRA) を施行した. 術直後より著明な腎機能の改善が得られ, 透析から離脱できるとともに慢性期の心不全の管理も容易となった.
    症例2: 63歳, 女性. 冠動脈3枝病変に対するバイパス術直前に, 両側RASによる難治性高血圧が顕在化した. 腎動脈エコー上, 腎硬化症の指標である腎抵抗係数は両側とも1.0と著明高値であったが, 薬物治療抵抗性の高血圧であったため両側RASに対してPTRA (ステント留置によるPTRA) を施行した. 術後血圧は著明に改善して降圧薬の減量が可能となり, その後冠動脈バイパス術が無事に施行された. 以上の2症例はいずれも症候性RASに対してPTRAが有効であった. 特異的な臨床徴候に乏しく見逃されることの多いRASとその病態, および適応をめぐっていまだ議論の多いPTRAを考えるうえで示唆に富む2症例であり, ここに報告する.
  • Aya Ebihara, Katsu Takenaka, Kansei Uno, Naoto Hayashi, Kazuno Sasaki, Mayumi Chigira, Tomoko Okano, Makoto Sonoda, Ryozo Nagai, Yutaka Yatomi
    Journal of Echocardiography 8 4 148 - 149 2010年 [査読有り][通常論文]
  • Nobukazu Ishizaka, Yuko Ishizaka, Ei-Ichi Toda, Kazuhiko Koike, Minoru Yamakado, Ryozo Nagai
    Kidney and Blood Pressure Research 32 6 421 - 427 2010年01月 [査読有り][通常論文]
     
    Aims and Methods: By analyzing data from 2,861 individuals who underwent general health screening 2 years running, we have investigated the impact of changes in waist circumference (WC) and body mass index (BMI) over a 1-year period on systolic blood pressure (BPs). We termed WC, BMI, and BPs at the first visit as WC1, BMI1, and BPs1, respectively, and those at the second visit as WC2, BMI2, and BPs2, respectively. The %dWC, %dBMI, and %dBPs was defined as (WC2 - WC1)/WC1 × 100, (BMI2 - BMI1)/BMI1 × 100, and (BPs2 - BPs1)/BPs1 × 100, respectively. Results: In multivariate regression analysis using age, BPs1, WC1, and %dWC as independent variables, %dWC was a significant predictor for %BPs only in men. %dBMI was a significant predictor for %BPs in both genders when age, BPs1, BMI1, and %dBMI were used as independent variables. Compared with individuals with both %dWC < 0 and %dBMI < 0, age-adjusted %dBPs was significantly greater in those with both %dWC < 0 and %dBMI ≥0 however, it did not significantly differ in those with both %dWC ≥0 and %dBMI < 0. Conclusion: Our data suggest that the impact of BMI change might be greater than WC change in terms of BPs change during this short period. © 2009 S. Karger AG, Basel.
  • Yuichi Uchino, Masafumi Watanabe, Yasunobu Hirata, Kunihiro Shigematsu, Tetsuro Miyata, Ryozo Nagai
    International heart journal 51 6 432 - 5 2010年 [査読有り][通常論文]
     
    We report the case of a 65-year-old woman with a solitary kidney who developed hypertension due to renal artery stenosis caused by fibromuscular dysplasia. In addition, an echocardiogram revealed severe left ventricular systolic and diastolic dysfunction. Despite antihypertensive drug treatment that included diuretics, her serum concentration of brain natriuretic peptide was persistently elevated and associated with progressive worsening of renal function. She underwent iliac artery to renal artery bypass grafting. After the surgery, blood pressure control was good, the serum concentration of brain natriuretic peptide decreased, and left ventricular diastolic function improved. This case exemplifies the efficacy of renal revascularization in patients with fibromuscular renal artery stenosis and heart failure.
  • Nobukazu Ishizaka, Yuko Ishizaka, Ei-Ichi Toda, Minoru Yamakado, Kazuhiko Koike, Ryozo Nagai
    JOURNAL OF ATHEROSCLEROSIS AND THROMBOSIS 17 5 476 - 485 2010年 [査読有り][通常論文]
     
    Aim: Alcohol intake may increase serum gamma-glutamyltransferase (GGT) but reduce insulin resistance. We analyzed the association between GGT and a marker of insulin resistance, homeostasis model assessment for insulin resistance (HOMA-IR), according to the drinking and smoking status. Methods: After excluding former smokers and/or former drinkers, the data of 10,482 men who underwent general health screening were analyzed. Results: Alcohol consumption showed a graded association with GGT. In men with current alcohol consumption of >= 40 g per day, >= 20 cigarettes per day further increased GGT levels. Alcohol consumption showed a U-shaped association with HOMA-IR. In contrast, smoking 20-39 and >= 40 cigarettes per day increased HOMA-IR as compared with never smokers. An interaction between alcohol consumption and smoking was present for GGT (p<0.001) and HOMA-IR (p = 0.059). GGT was not a significant negative predictive value for HOMA-IR regardless of the drinking or smoking status. Conclusions: Although alcohol intake showed a graded association with GGT and a U-shaped association with HOMA-IR, serum GGT can be utilized as a predictor of insulin resistance in current drinkers.
  • Takayuki Ohno, Osamu Kinoshita, Hideo Fujita, Satoshi Kato, Akira Hirose, Takashi Sigeeda, Kazuyoshi Otomo, Jiro Ando, Takashi Kadowaki, Makoto Araie, Ryozo Nagai, Shinichi Takamoto
    The Journal of thoracic and cardiovascular surgery 139 1 92 - 7 2010年01月 [査読有り][通常論文]
     
    OBJECTIVES: We hypothesized that a large number of patients with diabetic retinopathy who could benefit greatly from early coronary artery bypass grafting would not be identified. METHODS: Patients with diabetic retinopathy receiving ophthalmologic care as outpatients in our hospital in whom coronary artery disease was not previously suspected were referred randomly to the diabetic retinocoronary clinic and were asked to participate in diagnostic tests, including an exercise treadmill test and exercise thallium scintigraphy or coronary computed tomography. Patients who had type 1 diabetes mellitus, required hemodialysis, or both were excluded from this study. A definitive diagnosis of coronary artery disease was confirmed by means of coronary angiography. RESULTS: Of 214 patients with diabetic retinopathy, 55 (25.7%) were confirmed as having significant stenotic coronary artery disease. Patients with angiographically confirmed coronary disease were older than those with negative results on diagnostic tests (62.2 + or - 9.8 vs 57.9 + or - 10.3 years, P = .01). Fifteen had 1-vessel disease, 17 had 2-vessel disease, 14 had 3-vessel disease, 1 had left main trunk plus 1-vessel disease, 2 had left main trunk plus 2-vessel disease, and 5 had left main trunk plus 3-vessel disease. Eight patients had left main trunk disease, and 18 patients with non-left main trunk disease had proximal left anterior descending coronary artery (LAD) disease. Forty-two patients showed indications of coronary revascularization (coronary artery bypass grafting in 17 and percutaneous coronary intervention in 25). During the entire follow-up (287.6 + or - 183.2 days) of 39 patients undergoing coronary revascularization, all were alive without myocardial infarction, but 8 experienced vitreous hemorrhage. CONCLUSIONS: Approximately 25% of patients with diabetic retinopathy receiving ophthalmologic care as outpatients have a significant stenotic coronary artery disease. Of the total diabetic population, a large number of patients with diabetic retinopathy who show strong indications for early coronary artery bypass grafting might well go unrecognized.
  • Aiko Sakamoto, Yuko Ishizaka, Ei-Ichi Toda, Ryozo Nagai, Kazuhiko Koike, Minoru Yamakado, Nobukazu Ishizaka
    JOURNAL OF ATHEROSCLEROSIS AND THROMBOSIS 17 12 1246 - 1255 2010年 [査読有り][通常論文]
     
    Aim: Changes in indexes of obesity, such as waist circumference (WC) and body mass index (BMI), may influence some glucose metabolism-related parameters in both obese and non-obese subjects. We have investigated the impact of changes in WC and in BMI on data related to glucose metabolism over a one-year period. Methods: Data from 3213 individuals (2014 men, 1199 women) who underwent a general health screening two years running and were not taking antidiabetic medication were analyzed. Results: In men, percent changes in WC (%dWC) and BMI (%dBMI) were both significantly correlated with percent changes in fasting glucose (%dFG), in hemoglobin A(1c) (%dHbA(1c)), and in HOMA-IR (%dHOMA-IR). In women, these relationships were not significant except for the relationship between %dBMI and %dHOMA-IR. In a multivariate linear regression analysis using age, %dBMI, and %dWC as independent variables, %dBMI, but not %dWC, was found to be an independent predictor of %dHOMA-IR in both genders. Furthermore, in men, %dBMI was also an independent factor predicting %dFG and %dHbA(1c). Conclusion: During the one-year period, a reduction in BMI, and thus weight loss, was found to be associated with the improvement of insulin sensitivity, especially in men. A reduction in WC was also associated with an improvement in insulin sensitivity in men; however, this relationship did not remain significant after controlling for changes in BMI.
  • Nobukazu Ishizaka, Aiko Sakamoto, Kan Saito, Ryozo Nagai
    JOURNAL OF ATHEROSCLEROSIS AND THROMBOSIS 17 8 889 - 890 2010年 [査読有り][通常論文]
  • Norifumi Takeda, Ichiro Manabe, Yuichi Uchino, Kosei Eguchi, Sahohime Matsumoto, Satoshi Nishimura, Takayuki Shindo, Motoaki Sano, Kinya Otsu, Paige Snider, Simon J Conway, Ryozo Nagai
    The Journal of clinical investigation 120 1 254 - 65 2010年01月 [査読有り][通常論文]
     
    Fibroblasts, which are the most numerous cell type in the heart, interact with cardiomyocytes in vitro and affect their function; however, they are considered to play a secondary role in cardiac hypertrophy and failure. Here we have shown that cardiac fibroblasts are essential for the protective and hypertrophic myocardial responses to pressure overload in vivo in mice. Haploinsufficiency of the transcription factor-encoding gene Krüppel-like factor 5 (Klf5) suppressed cardiac fibrosis and hypertrophy elicited by moderate-intensity pressure overload, whereas cardiomyocyte-specific Klf5 deletion did not alter the hypertrophic responses. By contrast, cardiac fibroblast-specific Klf5 deletion ameliorated cardiac hypertrophy and fibrosis, indicating that KLF5 in fibroblasts is important for the response to pressure overload and that cardiac fibroblasts are required for cardiomyocyte hypertrophy. High-intensity pressure overload caused severe heart failure and early death in mice with Klf5-null fibroblasts. KLF5 transactivated Igf1 in cardiac fibroblasts, and IGF-1 subsequently acted in a paracrine fashion to induce hypertrophic responses in cardiomyocytes. Igf1 induction was essential for cardioprotective responses, as administration of a peptide inhibitor of IGF-1 severely exacerbated heart failure induced by high-intensity pressure overload. Thus, cardiac fibroblasts play a pivotal role in the myocardial adaptive response to pressure overload, and this role is partly controlled by KLF5. Modulation of cardiac fibroblast function may provide a novel strategy for treating heart failure, with KLF5 serving as an attractive target.
  • Takahide Kohro, Dobun Hayashi, Tsutomu Yamazaki, Ryozo Nagai
    Circulation Journal 74 5 962 - 969 2010年 [査読有り][通常論文]
     
    Background: Beta-blockers are underprescribed for coronary artery disease (CAD) patients in Japan. Considering the vast amount of evidence showing their benefits in this group of patients, the aim of the present study was to investigate the use of β-blockers in a large cohort of CAD patients. Methods and Results: The 13,812 patients with angiographically confirmed CAD were followed up for 2.7 years. From this group, 4,160 (30.1%) patients were prescribed β-blockers at the time of discharge. These patients were significantly more likely to have hypertension, hyperlipidemia, obesity, a family history of ischemic diseases and a higher number of diseased arteries. The rate of continuation for β-blockers was 90.8%. A propen-sity score matching analysis showed no additional benefits of β-blockers in reducing all-cause mortality, cardiac events and cerebrovascular events. Lipophilic β-blockers were significantly more effective than hydrophilic ones in reducing all-cause mortality (hazard ratio 0.467, 95% confidence interval 0.247-0.880, P=0.019). Conclusions: Despite the low prescription rate of β-blockers for CAD patients among Japanese physicians, the continuation rate was relatively high. Lipophilic β-blockers may be a better choice than hydrophilic β-blockers in terms of mortality risk, although a randomized control study would need to be conducted to verify this assertion.
  • Takahide Kohro, Masatoshi Fujita, Shigetake Sasayama, Satoko Mitani, Tsutomu Yamazaki, Dobun Hayashi, Yoshihiro Okada, Ryozo Nagai
    International Heart Journal 51 5 299 - 302 2010年 [査読有り][通常論文]
     
    Calcium channel blockers (CCB) and statins are frequently prescribed for patients with coronary artery disease (CAD) complicated by hypertension and/or hypercholesterolemia. CCB have pleiotropic actions beyond their blood pressure-lowering effect, while statins have pleiotropic actions beyond their cholesterol-lowering effect. We assessed the hypothesis that combined treatment with CCB and statins has additional prognostic benefits resulting from potential additive or synergistic pleiotropic actions of both classes of drugs in the Japanese CAD (JCAD) study population. The JCAD study consisted of 13,812 patients with angiographically demonstrable significant coronary narrowing in at least 1 of 3 major coronary arteries who were followed-up for a mean of 2.7 years (follow-up rate, 88.4%). The primary endpoint of the present study was all cardiovascular events. We compared the event rate between patients receiving neither CCB nor statins and those receiving each drug alone or as a combination treatment using propensity score matching analysis. The rate of all events was 62.8 per 1,000 patient-years in the JCAD study. Kaplan-Meier analysis with the logrank test showed no statistically significant difference in the event rate in each comparison. In conclusion, there may be no additional prognostic benefit beyond the blood-pressure-lowering and cholesterol-lowering effects in the combined treatment with CCB and statins for angiographically documented CAD patients.
  • Takayoshi Matsumura, Toru Suzuki, Kenichi Aizawa, Daigo Sawaki, Yoshiko Munemasa, Junichi Ishida, Ryozo Nagai
    The Journal of biological chemistry 284 51 35861 - 71 2009年12月 [査読有り][通常論文]
     
    Abnormal transforming growth factor-beta (TGF-beta) signaling is a critical contributor to the pathogenesis of various human diseases ranging from tissue fibrosis to tumor formation. Excessive TGF-beta signaling stimulates fibrotic responses. Recent research has focused in the main on the antiproliferative effects of TGF-beta in fibroblasts, and it is presently understood that TGF-beta-stimulated cyclooxygenase-2 (COX-2) induction in fibroblasts is essential for antifibroproliferative effects of TGF-beta. Both TGF-beta and COX-2 have been implicated in tumor growth, invasion, and metastasis, and therefore tumor-associated fibroblasts are a recent topic of interest. Here we report the identification of positive and negative regulatory factors of COX-2 expression induced by TGF-beta as determined using proteomic approaches. We show that TGF-beta coordinately up-regulates three factors, heterogeneous nuclear ribonucleoprotein A/B (HNRPAB), nucleotide diphosphate kinase A (NDPK A), and nucleotide diphosphate kinase A (NDPK B). Functional pathway analysis showed that HNRPAB augments mRNA and protein levels of COX-2 and subsequent prostaglandin E(2) (PGE(2)) production by suppressing degradation of COX-2 mRNA. In contrast, NDPK A and NDPK B attenuated mRNA and protein levels of COX-2 by affecting TGF-beta-Smad2/3/4 signaling at the receptor level. Collectively, we report on a new regulatory pathway of TGF-beta in controlling expression of COX-2 in fibroblasts, which advances our understanding of pathophysiological mechanisms of TGF-beta.
  • Shinichiro Uchiyama, Shinya Goto, Masayasu Matsumoto, Ryozo Nagai, Hideki Origasa, Tsutomu Yamazaki, Hiroshi Shigematsu, Kazuyuki Shimada, Nobuhiro Yamada, Deepak L. Bhatt, P. Gabriel Steg, Yasuo Ikeda
    Journal of the Neurological Sciences 287 1-2 45 - 51 2009年12月 [査読有り][通常論文]
     
    The REduction of Atherothrombosis for Continued Health (REACH) Registry is a large, international, prospective cohort of patients with atherothrombosis or multiple (≥ 3) risk factors (MRFs) for atherothrombosis. Japanese patients (n = 5193) were enrolled into the REACH registry between August and December 2004. One-year event rate in patients with cerebrovascular disease (CVD) was compared with that of patients with symptomatic atherothrombosis at other locations. After one year (n = 5021), patients with CVD (n = 1962) experienced a higher rate of non-fatal strokes than patients with coronary artery disease (CAD), peripheral artery disease (PAD) or MRFs alone (2.77% vs. 1.28%, 2.07% and 1.56%, respectively), but a lower rate of non-fatal myocardial infarction (0.45% vs. 1.31%, 0.77% and 0.66%, respectively). Patients with CVD plus disease in ≥ 1 other vascular bed had higher rates of cardiovascular events than patients with CVD alone. Overall, event rates including non-fatal stroke, non-fatal myocardial infarction and cardiovascular death were higher for patients with CVD and PAD than for patients with CVD and CAD. Asymptomatic carotid stenosis ≥ 70% and ankle-brachial index < 0.9 were significant predisposing factors for stroke. Patients with CVD and co-existing atherothrombotic diseases had a high risk of recurrent events, including events arising in other vascular beds than originally diagnosed. © 2009 Elsevier B.V.
  • Daiju Fukuda, Soichiro Enomoto, Ryozo Nagai, Masataka Sata
    BIOMEDICINE & PHARMACOTHERAPY 63 10 754 - 766 2009年12月 [査読有り][通常論文]
     
    Recent evidence indicates that renin-angiotensin system (RAS) plays an important role in the pathogenesis of atherosclerosis. It was reported that inhibition of RAS with angiotensin II type I receptor blockers (ARBs) or angiotensin converting enzyme inhibitors (ACEIs) is effective in prevention of atherosclerosis. Here, we investigated the effects of an ARB or/and an ACEI on atherosclerosis development and periadventitial inflammation in apolipoprotein E (ApoE)-deficient mice. RT-PCR revealed that major RAS components were expressed in periaortic tissue. Ang II infusion significantly increased accumulation of bone marrow derived cells into both neointima (p < 0.05) and periaortic tissue (p < 0.01). Male ApoE- deficient mice were treated with either vehicle, TA606A (10 mg/kg/day, ARB), imidapril Q mg/kg/day, ACEI) or TA606A plus imidapril (TA606A 10 mg/kg/day + imidapril 3 mg/kg/day, ARB + ACEI) for 24 weeks starting at 12 weeks of age. ARB, ACEI, and ARB + ACEI significantly reduced atherosclerotic lesion formation in aorta compared with vehicle (p < 0.05), with reduced expression of monocyte chemoattractant protein-1 in periaortic tissues (p < 0.01). Neither blood pressure nor heart rate was changed by the treatments at these lower doses. Imidapril significantly reduced lipid deposition in atheroma and plasminogen activator inhibitor-1 expression in periadventitial tissue (p < 0.05, respectively). Imidapril and combination therapy significantly attenuated macrophage infiltration into the atherosclerotic plaque (p < 0.05, respectively). All treatments reduced macrophage accumulation in the periadventitial tissue 12 weeks after treatment (p < 0.05, respectively). These results suggest that inhibition of renin-angiotensin system attenuates periadventitial inflammation and reduces atherosclerotic lesion formation. (C) 2009 Elsevier Masson SAS. All rights reserved.
  • Nakajima Toshiaki, Kurano Miwa, Iida Haruko, Takano Haruhito, Fukuda Taira, Nagasaki Mika, Monzen Koshiro, Uno Kansei, Kato Masayoshi, Meguro Kentaro, Shiga Taro, Maemura Koji, Masuda Nobuhito, Hirata Yasunobu, Nagai Ryozo
    CIRCULATION 120 18 S434  2009年11月 [査読有り][通常論文]
  • Higashikuni Yasutomi, Nakamura Kazuto, Takaoka Minoru, Enomoto Soichiro, Iwata Hiroshi, Sahara Makoto, Tanaka Kimie, Sata Masataka, Nagai Ryozo
    CIRCULATION 120 18 S1041  2009年11月 [査読有り][通常論文]
  • Takaoka Minoru, Nagai Ryozo, Sata Masataka
    CIRCULATION 120 18 S1065  2009年11月 [査読有り][通常論文]
  • Tanaka Kimie, Nagata Daisuke, Hirata Yasunobu, Tabata Yasuhiko, Nagai Ryozo, Sata Masataka
    CIRCULATION 120 18 S1067  2009年11月 [査読有り][通常論文]
  • Iwata Hiroshi, Manabe Ichiro, Fujiu Katsuhito, Takeda Norifumi, Eguchi Kosei, Sata Masataka, Nagai Ryozo
    CIRCULATION 120 18 S1090 - S1091 2009年11月 [査読有り][通常論文]
  • Wrapped Liposome siRNAを用いた抗VEGF療法のマウスにおける全身的影響
    高橋 秀徳, 八木 信宏, 山内 雅博, 柳 靖雄, 玉置 泰裕, 真鍋 一郎, 永井 良三
    眼科臨床紀要 2 11 1046 - 1046 眼科臨床紀要会 2009年11月
  • Hiroaki Obata, Nobuhiro Yagi, Shunsuke Ohnishi, Kenichi Yamahara, Toshihito Hosokawa, Ichiro Manabe, Makoto Kodama, Yoshifusa Aizawa, Ryozo Nagai, Noritoshi Nagaya
    CIRCULATION 120 18 S841 - S841 2009年11月 [査読有り][通常論文]
  • Minoru Takaoka, Daisuke Nagata, Shinji Kihara, Iichiro Shimomura, Yu Kimura, Yasuhiko Tabata, Yoshihiko Saito, Ryozo Nagai, Masataka Sata
    Circulation Research 105 9 906 - 911 2009年10月 [査読有り][通常論文]
     
    Rationale: Obesity is associated with a high incidence of cardiovascular complications. However, the molecular link between obesity and vascular disease is not fully understood. Most previous studies have focused on the association between cardiovascular disease and accumulation of visceral fat. Periadventitial fat is distributed ubiquitously around arteries throughout the body. Objective: Here, we investigated the impact of obesity on inflammation in the periadventitial adipose tissue and on lesion formation after vascular injury. Methods and Results: High-fat, high-sucrose feeding induced inflammatory changes and decreased adiponectin expression in the periadventitial adipose tissue, which was associated with enhanced neointima formation after endovascular injury. Removal of periadventitial fat markedly enhanced neointima formation after injury, which was attenuated by transplantation of subcutaneous adipose tissue from mice fed on regular chow. Adiponectindeficient mice showed markedly enhanced lesion formation, which was reversed by local delivery, but not systemic administration, of recombinant adiponectin to the periadventitial area. The conditioned medium from subcutaneous fat attenuated increased cell number of smooth muscle cells in response to platelet derived growth factor-BB. Conclusions: Our findings suggest that periadventitial fat may protect against neointimal formation after angioplasty under physiological conditions and that inflammatory changes in the periadventitial fat may have a direct role in the pathogenesis of vascular disease accelerated by obesity. © 2009 American Heart Association, Inc.
  • Motohiro Sekiya, Naoya Yahagi, Yoshiaki Tamura, Hiroaki Okazaki, Masaki Igarashi, Keisuke Ohta, Mikio Takanashi, Masayoshi Kumagai, Satoru Takase, Makiko Nishi, Yoshinori Takeuchi, Yoshihiko Izumida, Midori Kubota, Ken Ohashi, Yoko Iizuka, Hiroaki Yagyu, Takanari Gotoda, Ryozo Nagai, Hitoshi Shimano, Nobuhiro Yamada, Takashi Kadowaki, Shun Ishibashi, Jun-ichi Osuga
    Biochemical and biophysical research communications 387 3 511 - 5 2009年09月 [査読有り][通常論文]
     
    It has long been a matter of debate whether the hormone-sensitive lipase (HSL)-mediated lipolysis in pancreatic beta-cells can affect insulin secretion through the alteration of lipotoxicity. We generated mice lacking both leptin and HSL Lep(ob/ob)/HSL(-/-) and explored the role of HSL in pancreatic beta-cells in the setting of obesity. Lep(ob/ob)/HSL(-/-) developed elevated blood glucose levels and reduced plasma insulin levels compared with Lep(ob/ob)/HSL(+/+) in a fed state, while the deficiency of HSL did not affect glucose homeostasis in Lep(+/+) background. The deficiency of HSL exacerbated the accumulation of triglycerides in Lep(ob/ob) islets, leading to reduced glucose-stimulated insulin secretion. The deficiency of HSL also diminished the islet mass in Lep(ob/ob) mice due to decreased cell proliferation. In conclusion, HSL affects insulin secretary capacity especially in the setting of obesity.
  • 武田 憲文, 真鍋 一郎, 内野 悠一, 永井 良三, 佐野 元昭, 大津 欣也, Snider Paige, Conway Simon J.
    日本内分泌学会雑誌 85 2 713 - 713 (一社)日本内分泌学会 2009年09月 [査読有り][通常論文]
  • Motohiro Sekiya, Jun-Ichi Osuga, Shuichi Nagashima, Taichi Ohshiro, Masaki Igarashi, Hiroaki Okazaki, Manabu Takahashi, Fumiko Tazoe, Taeko Wada, Keisuke Ohta, Mikio Takanashi, Masayoshi Kumagai, Makiko Nishi, Satoru Takase, Naoya Yahagi, Hiroaki Yagyu, Ken Ohashi, Ryozo Nagai, Takashi Kadowaki, Yusuke Furukawa, Shun Ishibashi
    Cell metabolism 10 3 219 - 28 2009年09月 [査読有り][通常論文]
     
    Cholesterol ester (CE)-laden macrophage foam cells are the hallmark of atherosclerosis, and the hydrolysis of intracellular CE is one of the key steps in foam cell formation. Although hormone-sensitive lipase (LIPE) and cholesterol ester hydrolase (CEH), which is identical to carboxylsterase 1 (CES1, hCE1), were proposed to mediate the neutral CE hydrolase (nCEH) activity in macrophages, recent evidences have suggested the involvement of other enzymes. We have recently reported the identification of a candidate, neutral cholesterol ester hydrolase 1(Nceh1). Here we demonstrate that genetic ablation of Nceh1 promotes foam cell formation and the development of atherosclerosis in mice. We further demonstrate that Nceh1 and Lipe mediate a comparable degree of nCEH activity in macrophages and together account for most of the activity. Mice lacking both Nceh1 and Lipe aggravated atherosclerosis in an additive manner. Thus, Nceh1 is a promising target for the treatment of atherosclerosis.
  • Nobuhiro Yagi, Ichiro Manabe, Tsuneaki Tottori, Atsushi Ishihara, Fusa Ogata, Jong Heon Kim, Satoshi Nishimura, Katsuhito Fujiu, Yumiko Oishi, Keiji Itaka, Yasuki Kato, Masahiro Yamauchi, Ryozo Nagai
    Cancer research 69 16 6531 - 8 2009年08月 [査読有り][通常論文]
     
    Use of short interfering RNA (siRNA) is a promising new approach thought to have a strong potential to lead to rapid development of gene-oriented therapies. Here, we describe a newly developed, systemically injectable siRNA vehicle, the "wrapsome" (WS), which contains siRNA and a cationic lipofection complex in a core that is fully enveloped by a neutral lipid bilayer and hydrophilic polymers. WS protected siRNA from enzymatic digestion, providing a long half-life in the systemic circulation. Moreover, siRNA/WS leaked from blood vessels within tumors into the tumor tissue, where it accumulated and was subsequently transfected into the tumor cells. Because the transcription factor KLF5 is known to play a role in tumor angiogenesis, we designed KLF5-siRNA to test the antitumor activity of siRNA/WS. KLF5-siRNA/WS exhibited significant antitumor activity, although neither WS containing control scrambled-siRNA nor saline containing KLF5-siRNA affected tumor growth. KLF5-siRNA/WS inhibited Klf5 expression within tumors at both mRNA and protein levels, significantly reducing angiogenesis, and we detected no significant acute or long-term toxicity. Our findings support the idea that siRNA/WS can be used to knock down specific genes within tumors and thereby exert therapeutic effects against cancers.
  • Satoshi Nishimura, Ichiro Manabe, Ryozo Nagai
    Discovery medicine 8 41 55 - 60 2009年08月 [査読有り][通常論文]
     
    Metabolic syndrome is a major risk factor for cardiovascular and metabolic diseases. Playing a central role in the development of metabolic syndrome and in its clinical consequences is visceral obesity. Adipose tissue is now considered to be an active endocrine organ that secretes various humoral factors (adipokines), and its shift to production of proinflammatory cytokines in obesity likely contributes to the low-level systemic inflammation that is seen in metabolic syndrome-associated chronic pathologies such as atherosclerosis. Recent studies have shown that obesity induces chronic local inflammation in adipose tissue, and that cells of the innate immune system, particularly macrophages, are crucially involved in adipose inflammation and systemic metabolic abnormalities. Moreover, we and others recently revealed that T cells are key regulators of adipose inflammation, and that the adaptive immune system is also crucially important. In mouse models modulation of T cell function ameliorated not only adipose inflammation but also systemic insulin resistance induced by obesity. Thus clarification of the inflammatory processes ongoing in obese adipose tissue would seem essential for the understanding of metabolic syndrome and for developing novel therapeutic strategies to treat it.
  • Satoshi Nishimura, Ichiro Manabe, Mika Nagasaki, Koji Eto, Hiroshi Yamashita, Mitsuru Ohsugi, Makoto Otsu, Kazuo Hara, Kohjiro Ueki, Seiryo Sugiura, Kotaro Yoshimura, Takashi Kadowaki, Ryozo Nagai
    Nature medicine 15 8 914 - 20 2009年08月 [査読有り][通常論文]
     
    Inflammation is increasingly regarded as a key process underlying metabolic diseases in obese individuals. In particular, obese adipose tissue shows features characteristic of active local inflammation. At present, however, little is known about the sequence of events that comprises the inflammatory cascade or the mechanism by which inflammation develops. We found that large numbers of CD8(+) effector T cells infiltrated obese epididymal adipose tissue in mice fed a high-fat diet, whereas the numbers of CD4(+) helper and regulatory T cells were diminished. The infiltration by CD8(+) T cells preceded the accumulation of macrophages, and immunological and genetic depletion of CD8(+) T cells lowered macrophage infiltration and adipose tissue inflammation and ameliorated systemic insulin resistance. Conversely, adoptive transfer of CD8(+) T cells to CD8-deficient mice aggravated adipose inflammation. Coculture and other in vitro experiments revealed a vicious cycle of interactions between CD8(+) T cells, macrophages and adipose tissue. Our findings suggest that obese adipose tissue activates CD8(+) T cells, which, in turn, promote the recruitment and activation of macrophages in this tissue. These results support the notion that CD8(+) T cells have an essential role in the initiation and propagation of adipose inflammation.
  • Hiroshi Iwata, Kazuto Nakamura, Makoto Sumi, Mikio Ninomiya, Yoshiki Sakai, Yoichiro Hirata, Masahi Akaike, Takashi Igarashi, Shinichi Takamoto, Ryozo Nagai, Masataka Sata
    Life sciences 85 5-6 255 - 61 2009年07月 [査読有り][通常論文]
     
    AIMS: It was reported that administration of angiogenic growth factors can augment collateral growth in ischemic tissues. It is assumed that angiogenic effects of cell transplantation may be mainly mediated by secretion of angiogenic cytokines. We tested feasibility of clinical use of ONO-1301, a synthetic small molecule that stimulates secretion of growth factors from various cell types, to treat patients with chronic myocardial ischemia. MAIN METHODS: Effects of ONO-1301 on fibroblasts and endothelial cells were evaluated in vitro. We examined the efficacy of local delivery of ONO-1301 in models of rat hindlimb ischemia and swine chronic ischemic myocardium. KEY FINDINGS: ONO-1301 stimulated hepatocyte growth factor secretion from human fibroblasts. ONO-1301 promoted vascular-like tube formation by endothelial cells in vitro. Direct injection of a slow-release form of ONO-1301 (SR-ONO) to rat hindlimb ischemic muscle enhanced perfusion recovery. In a swine cardiac ischemia model, direct injection of SR-ONO into the ischemic myocardium significantly augmented collateral formation (SR-ONO vs. control; 1.7+/-0.2 vs. 1.0+/-0.2 Rentrop score), with improved local ventricular wall motion, reduced enlargement of left ventricular diastolic volume (49.5+/-1.9 mL vs. 59.7+/-4.2 mL) and increased cardiac index (4.2+/-0.1 vs. 3.4+/-0.2 L/min/m(2)). Histological analysis revealed that SR-ONO suppressed fibrosis in ischemic tissue (collagen volume fraction; 7.5+/-1.1% vs. 12.8+/-2.2%) and enhanced neovascularization (capillary density, 275.6 vs. 159.3/mm(2); arterioles 36.6 vs. 25.5 /mm(2)). SIGNIFICANCE: Local delivery of SR-ONO might be effective for therapeutic angiogenesis and propose that local administration of slow-release of synthetic small molecules represents new strategy for therapeutic angiogenesis.
  • Yuko Ishizaka, Nobukazu Ishizaka, Mizuki Tani, Akiko Toda, Ei-Ichi Toda, Kazuhiko Koike, Ryozo Nagai, Minoru Yamakado
    Kidney and Blood Pressure Research 32 2 141 - 149 2009年06月 [査読有り][通常論文]
     
    Obesity increases the risk for chronic kidney disease (CKD). By analyzing data on individuals who underwent general health screening in two consecutive years, we investigated whether changes in body mass index (BMI) or waist circumference (WC) were associated with the appearance or disappearance of the CKD components micro-/macroalbuminuria (≥30 mg urinary albumin per gram creatinine) and a low estimated glomerular filtration rate (eGFR < 60 ml/min/1.73 m2). Logistic regression analysis showed that in men with micro-/macroalbuminuria at the first visit, a BMI reduction of ≥0.42 or a WC reduction of ≥3.0 cm over the 1-year period resulted in a significantly reduced incident of micro-/macroalbuminuria at the second visit. On the other hand, a BMI gain of ≥0.33 over 1 year in men without micro-/macroalbuminuria and a low eGFR at the fist visit significantly increased the incident of micro-/macroalbuminuria and a low eGFR, respectively, at the second visit. These findings indicate that lowering the obesity indexes in men with micro-/macroalbuminuria reduced the incidence of this condition at the 1-year follow-up and that, on the contrary, an increase in BMI in men without micro-/macroalbuminuria and a low eGFR at the first examination increased the risk of these conditions during the 1-year follow-up period. © 2009 S. Karger AG, Basel.
  • Nobukazu Ishizaka, Yuko Ishizaka, Minoru Yamakado, Eiichi Toda, Kazuhiko Koike, Ryozo Nagai
    ATHEROSCLEROSIS 204 2 619 - 623 2009年06月 [査読有り][通常論文]
     
    Introduction: Whether or not metabolic syndrome is predictive of atherosclerotic disorders may depend on the population studied. We investigated whether metabolic syndrome is associated with carotid atherosclerosis in individuals who were shown not to have diabetes mellitus based on results of the 75-g oral glucose tolerance test (OGTT). Methods and results: Between 1994 and 2003, 3904 individuals underwent general health screening that included the OGTT. Among these 3904 individuals, 3679 had a fasting plasma glucose of <126 mg/dL (subgroup 1), and 3488 had a 2-h post-OGTT glucose value of <200 mg/dL (subgroup 2). In both subgroups, metabolic syndrome was found to be a risk factor for carotid plaque and for carotid intima-media thickening in men, and tended to be a risk factor for carotid plaque in women after adjustment for age. Among 3473 individuals who had both a fasting plasma glucose value of <126 mg/dL and a 2-h post-OGTT glucose of <200 mg/dL, 2440 did not have hypertension, which was defined as systolic and diastolic blood pressure of <140/90 mmHg and absence of use of anti-hypertensive medication. In these non-diabetic non-hypertensive individuals, the association between metabolic syndrome and carotid plaque or carotid intima-media thickening was not statistically significant even with adjustment only for age. Conclusions: In men who did not have impaired fasting glycemia and/or in those without impaired glucose tolerance, metabolic syndrome was a predictor of carotid atherosclerosis after age adjustment, although metabolic syndrome was not found to be a predictor of carotid atherosclerosis when hypertensive individuals were excluded from the study population. (C) 2008 Elsevier Ireland Ltd. All rights reserved.
  • Masahito Ogawa, Jun-Ichi Suzuki, Hisanori Kosuge, Kiyoshi Takayama, Ryozo Nagai, Mitsuaki Isobe
    TRANSPLANTATION 87 11 1645 - 1653 2009年06月 [査読有り][通常論文]
     
    Background. Prostaglandin E-2 (PGE(2)) is a pathogenesis of inflammatory diseases; PGE(2) plays a key role in association of anti-inflammation and immune suppression. EP4, which is a PGE(2) receptor, is known to suppress the production of inflammatory cytokines and chemokines in vitro. Although it has been reported that EP4 agonists prolonged cardiac allograft survival, little has been elucidated the immunologic mechanism. Methods. We injected a selective EP4 agonist (EP4RAG) into recipient mice with heterotopic cardiac transplantation. Results. EP4RAG significantly prolonged the graft survival compared with the vehicle-treated group. Although the vehicle-treated group showed severe myocardial cell infiltration, the EP4RAG-treated group attenuated the development on day 7. EP4RAG suppressed various proinflammatory factors such as cytokines, chemokines, adhesion molecules, and nuclear factor-kappa B (NF-kappa B) compared with the vehicle-treated group. We also demonstrated that EP4RAG suppressed the activation of macrophages, but it did not affect to T lymphocytes in vitro. EP4RAG inhibited the activation of NF-kappa B compared with the control group. Conclusion. Pharmacological selective EP4 activation suppressed the production of proinflammatory factors by inhibition of NF-kappa B activity in cardiac transplantation.
  • Daiju Fukuda, Soichiro Enomoto, Ibuki Shirakawa, Ryozo Nagai, Masataka Sata
    EUROPEAN JOURNAL OF PHARMACOLOGY 612 1-3 87 - 92 2009年06月 [査読有り][通常論文]
     
    Sirolimus-eluting stent reduces restenosis after percutaneous coronary intervention. However. accumulating evidence suggests that sirolimus potentially affects re-endothelialization, leading to late thrombosis. Statins have protective effects on endothelium. Recently, statins are reported to increase the number of circulating endothelial progenitor cells (EPCs) and accelerate re-endothelialization after vascular injury. Here, we tested the hypothesis that fluvastatin has beneficial effect oil re-endothelialization after local sirolimus treatment. We performed wire-mediated vascular injury to both sides of femoral arteries of wild-type mice and bone marrow chimeric mice. Either sirolimus (100 mu g) or DMSO was administered locally to the perivascular area of the injured arteries. All mice received either fluvastatin (5 mg/kg/day) or vehicle by gavage starting at one week before the surgery until sacrifice. At 4 weeks after the surgery, re-endothelialization of the sirolimus-treated artery was significantly less than that of DMSO-treated one in the vehicle-treated mice as determined by the percentage of CD31-positive area (P<0.05). Systemic administration of fluvastatin accelerated the re-endothelialization in the sirolimus-treated artery to the similar degree of that in the DMSC-treated artery (P=NS). Contribution of bone marrow-derived cells to re-endothelialization was seldom observed in bone marrow chimeric mice regardless Of fluvastatin administration. Fluvastatin significantly ameliorated proliferation (2.5-folds) and migration activities (2.3-folds) of mature endothelial cells impaired by sirolimus treatment (P<0.05. respectively). Fluvastatin increased endothelial nitric oxide synthase expression and decreased plasminogen activator inhibitor-1 expression in mature endothelial cell in the presence of sirolimus (P<0.05, respectively). Our findings suggest that fluvastatin has protective effects against impaired re-endothelialization after sirolimus treatment. (C) 2009 Elsevier B.V. All rights reserved.
  • Toru Suzuki, Alessandro Distante, Antonella Zizza, Santi Trimarchi, Massimo Villani, Jorge Antonio Salerno Uriarte, Luigi De Luca Tupputi Schinosa, Attilio Renzulli, Federico Sabino, Richard Nowak, Robert Birkhahn, Judd E Hollander, Francis Counselman, Ravi Vijayendran, Eduardo Bossone, Kim Eagle
    Circulation 119 20 2702 - 7 2009年05月 [査読有り][通常論文]
     
    BACKGROUND: D-dimer has been reported to be elevated in acute aortic dissection. Potential use as a "rule-out" marker has been suggested, but concerns remain given that it is elevated in other acute chest diseases, including pulmonary embolism and ischemic heart disease. We evaluated the diagnostic performance of D-dimer testing in a study population of patients with suspected aortic dissection. METHODS AND RESULTS: In this prospective multicenter study, 220 patients with initial suspicion of having acute aortic dissection were enrolled, of whom 87 were diagnosed with acute aortic dissection and 133 with other final diagnoses, including myocardial infarction, angina, pulmonary embolism, and other uncertain diagnoses. D-dimer was markedly elevated in patients with acute aortic dissection. Analysis according to control disease, type of dissection, and time course showed that the widely used cutoff level of 500 ng/mL for ruling out pulmonary embolism also can reliably rule out aortic dissection, with a negative likelihood ratio of 0.07 throughout the first 24 hours. CONCLUSIONS: D-dimer levels may be useful in risk stratifying patients with suspected aortic dissection to rule out aortic dissection if used within the first 24 hours after symptom onset.
  • Masahito Ogawa, Jun-Ichi Suzuki, Yasunobu Hirata, Ryozo Nagai, Mitsuaki Isobe
    Expert opinion on therapeutic targets 13 5 505 - 11 2009年05月 [査読有り][通常論文]
     
    BACKGROUND: Inflammation plays an important role in neointimal hyperplasia after vascular injury. COX-2 is a key mediator of inflammation and contributes to several inflammatory diseases. Although selective COX-2 inhibitors affect pathological conditions in inflammatory diseases, little is known about the effects on vascular remodeling after mechanical injury. METHODS: To clarify the role of COX-2 in vascular remodeling after arterial injury, we made a wire-injury model using C57BL/6J mice. These mice were orally administrated a selective COX-2 inhibitor twice a day. COX-2 mRNA expression was analyzed in injured femoral arteries. RESULTS: COX-2 expression was markedly enhanced in the arterial wall on day 7; the expression was gradually decreased from day 14. In histopathological analyses, the COX-2 inhibitor significantly suppressed the progression of neointimal formation in comparison with non-treated mice. In an in vitro study, RNA was collected from macrophages after stimulation. The stimulation resulted in enhanced expression of IL-6 compared with the control, and the COX-2 inhibitor decreased this expression. CONCLUSION: COX-2 is enhanced in the neointima after mechanical injury, and inhibition attenuated this. Therefore, regulation of COX-2 may be useful for preventing neointimal formation after coronary intervention.
  • Hirofumi Kambara, Tsutomu Yamazaki, Doubun Hayashi, Takahide Kohro, Yoshihiro Okada, Ryozo Nagai
    Circulation Journal 73 5 912 - 917 2009年05月 [査読有り][通常論文]
     
    Background: Gender differences among patients with coronary artery disease vary from study to study. In one of the largest studies, the Japanese Coronary Artery Disease (JCAD) Study, gender differences in patients were investigated. Methods and Results: Consecutive patients diagnosed with stenosis 75% or more in at least one branch of the coronary arteries were enrolled in the study. The endpoint is a composite of all-cause death and cardiovascular events. Data were collected over the internet. Out of 15,628 patients screened, 13,812 of them met the inclusion criteria and were followed up for a mean period of 2.7 years. The event rate was 62.8 per 1,000 patients-year, all-cause death 17.3 and total cardiac events 47.4. The incident rate of unstable angina was higher in females (27.1) than males (21.8) (P=0.0363). The incidence of all-cause death was lower in females than males (16.9 and 17.8, respectively P=0.0148). Other than gender, hypertension and number of vessel disease contribute to the event of unstable angina, and age, family history, obesity, impaired fasting glycemia, hyperlipidemia, congestive heart failure and number of vessel disease contribute to the all-cause death. Conclusions: Gender is an independent contributing factor of unstable angina and of all-cause death.
  • Takafumi Okura, Jitsuo Higaki, Mie Kurata, Jun Irita, Ken-Ichi Miyoshi, Tsutomu Yamazaki, Doubun Hayashi, Takahide Kohro, Ryozo Nagai
    Circulation Journal 73 5 885 - 891 2009年05月 [査読有り][通常論文]
     
    Background: The association of elevated serum uric acid (UA) with cardiovascular events in patients with severe coronary artery stenosis was examined. Methods and Results: Patients with stenosis ≥75% (n=8,832) were followed for "all events" (cardiovascular events and all-cause mortality) for 3 years. The group was divided into quartiles based on baseline UA level. The incidence rate of all events was significantly different among quartiles (58.3, 56.5, 61.2, 76.3/1,000 patients-year, P< 0.001). Cox's proportional hazard regression analysis showed that the hazard ratio (HR) for all events was 1.25 [95% confidence interval (CI): 1.07-1.45, P< 0.01] in the highest quartile (UA ≥6.8 mg/dl). The group in which UA increased ≥1.0 mg/dl after 6 months had significantly higher cardiovascular events rate than the group in which UA did not change (70.6 vs 58.8/1,000 patients-year, P=0.042). Propensity score matching was performed and 4,206 patients were divided into the highest quartile and the rest. High UA remained an independent predictor of all events (HR 1.25, 95%CI 1.06-1.43). However, no significant difference was observed between the group with increased UA ≥1.0 mg/dl and the group with unchanged UA level. Conclusions: Elevated UA is an independent predictor of cardiovascular events and all-cause mortality combined in patients with coronary artery stenosis.
  • Motoharu Awazawa, Kohjiro Ueki, Kazunori Inabe, Toshimasa Yamauchi, Kazuma Kaneko, Yukiko Okazaki, Nabeel Bardeesy, Shin Ohnishi, Ryozo Nagai, Takashi Kadowaki
    Biochemical and biophysical research communications 382 1 51 - 6 2009年04月 [査読有り][通常論文]
     
    Adiponectin, one of the insulin-sensitizing adipokines, has been shown to activate fatty acid oxidation in liver and skeletal muscle, thus maintaining insulin sensitivity. However, the precise roles of adiponectin in fatty acid synthesis are poorly understood. Here we show that adiponectin administration acutely suppresses expression of sterol regulatory element-binding protein (SREBP) 1c, the master regulator which controls and upregulates the enzymes involved in fatty acid synthesis, in the liver of +Lepr(db)/+Lepr(db) (db/db) mouse as well as in cultured hepatocytes. We also show that adiponectin suppresses SREBP1c by AdipoR1, one of the functional receptors for adiponetin, and furthermore that suppressing either AMP-activated protein kinase (AMPK) via its upstream kinase LKB1 deletion cancels the negative effect of adiponectin on SREBP1c expression. These data show that adiponectin suppresses SREBP1c through the AdipoR1/LKB1/AMPK pathway, and suggest a possible role for adiponectin in the regulation of hepatic fatty acid synthesis.
  • Toru Suzuki, Daigo Sawaki, Kenichi Aizawa, Yoshiko Munemasa, Takayoshi Matsumura, Junichi Ishida, Ryozo Nagai
    The Journal of biological chemistry 284 14 9549 - 57 2009年04月 [査読有り][通常論文]
     
    Krüppel-like factor 5 (KLF5), originally isolated as a regulator of phenotypic modulation of vascular smooth muscle cells, induces pathological cell growth and is expressed in the neointima. Although induction of KLF5 up-regulates growth factors like platelet-derived growth factor-A chain, how KLF5 actually contributes to vascular remodeling, notably its direct effects on cell proliferation, had been poorly clarified. To investigate the effects of KLF5 on neointimal formation, we at first performed adenoviral overexpression of KLF5 to rats subjected to carotid balloon injury. Neointimal formation and proliferating cell nuclear antigen-positive rate were significantly increased at 14 days after injury in the KLF5-treated animals. At the cellular level, overexpression of KLF5 also resulted in markedly increased cell proliferation and cell cycle progression. As a molecular mechanism, we showed that KLF5 directly bound to the promoter and up-regulated gene expression of cyclin D1, as well as showing specific transactivation of cyclins and cyclin-dependent kinase inhibitors in cardiovascular cells. Conversely, knockdown of KLF5 by RNA interference specifically down-regulated cyclin D1 and impaired vascular smooth muscle cell proliferation. Furthermore, KLF5 attenuated cleavage of caspase-3 under conditions of apoptotic stimulation. Moreover, KLF5-administered animals exhibited a significant decrease in terminal deoxynucleotidyltransferase-mediated dUTP nick end-labeling-positive cells in the medial layer, suggesting inhibition of apoptosis in the early phase after denudation. These findings collectively suggest that KLF5 plays a central role in cardiovascular pathologies through direct and specific stimulation of cell growth as well as inhibition of apoptosis.
  • 急性心筋梗塞を契機に顕在化したcapillary leak syndromeの一例
    小島 敏弥, 武藤 浩司, 岩田 洋, 都島 健介, 山下 尋史, 平田 恭信, 永井 良三, 槙田 紀子, 縄田 寛, 本村 昇
    Circulation Journal 73 Suppl.II 979 - 979 (一社)日本循環器学会 2009年04月 [査読有り][通常論文]
  • 心リモデリングにおける転写因子KLF5の役割
    武田 憲文, 真鍋 一郎, 永井 良三
    日本臨床分子医学会学術総会プログラム・抄録集 46回 62 - 62 日本臨床分子医学会 2009年04月 [査読有り][通常論文]
  • 高ホモシステイン血症モデルラットにおける心障害の検討
    木村 公一, 森田 啓行, 武田 憲文, 稲島 司, 真鍋 一郎, 永井 良三
    日本臨床分子医学会学術総会プログラム・抄録集 46回 63 - 63 日本臨床分子医学会 2009年04月 [査読有り][通常論文]
  • レチノイン酸受容体アンタゴニストは圧負荷モデルにおける心肥大およびリモデリングを抑制する
    内野 悠一, 真鍋 一郎, 武田 憲文, 藤生 克仁, 岩田 洋, 永井 良三
    日本臨床分子医学会学術総会プログラム・抄録集 46回 64 - 64 日本臨床分子医学会 2009年04月 [査読有り][通常論文]
  • Hiroyuki Atsuta, Tsuyoshi Uchiyama, Hiroyoshi Kanai, Tatsuya Iso, Toru Tanaka, Tatsuo Suga, Toshitaka Maeno, Masashi Arai, Ryozo Nagai, Masahiko Kurabayashi
    International journal of cardiology 132 3 411 - 8 2009年03月 [査読有り][通常論文]
     
    BACKGROUND: Beraprost sodium, an orally active prostacyclin analogue, has proved to be beneficial for the patients with primary pulmonary hypertension and obstructive peripheral arterial disease. METHODS: In this study, we examined the effects of BPS on the expression of the VEGF and PAI-1 genes in vascular smooth muscle cells. RESULTS: The mRNA levels for VEGF were increased by BPS in C2/2 cells and cultured rat aortic smooth muscle cells. In contrast, PAI-1 mRNA levels were significantly decreased by BPS. Luciferase assays and mRNA decay assays showed that BPS increases VEGF promoter activity and has no effects on its mRNA stability. Likewise, BPS decreases PAI-1 promoter activity without affecting its mRNA stability. Experiments using various pharmacological inhibitors for protein kinases showed that activation of cAMP-dependent protein kinase (PKA) was involved in BPS-mediated regulation of VEGF and PAI-1 mRNA expression. Overexpression of CREB (cAMP-responsive element binding protein) induces VEGF promoter and reduces PAI-1 promoter activities. CREMepsilon, a dominant negative form of CREB, inhibits BPS-mediated changes in VEGF and PAI-1 promoter activities. While BPS augmented hypoxia-induced VEGF mRNA expression, it blunted hypoxia-induced PAI-1 mRNA expression. CONCLUSION: These results suggest that BPS increases VEGF and decreases PAI-1 gene expression through PKA/CREB-dependent mechanisms in vascular smooth muscle cells. Because these effects are observed more prominently under the hypoxic condition compared to normoxic condition, BPS may have a potential to relieve hypoxia by inducing neovasculization and by reducing thrombosis.
  • VEGF及び受容体を標的にしたWrapped Liposome/siRNA全身投与における臓器副作用の検討
    高橋 秀徳, 八木 信宏, 山内 雅博, 柳 靖雄, 玉置 泰裕, 真鍋 一郎, 永井 良三
    日本眼科学会雑誌 113 臨増 201 - 201 (公財)日本眼科学会 2009年03月
  • 糖尿病網膜症患者におけるCABG・DES留置後の硝子体出血頻度 DES留置は禁忌?
    川島 大, 大野 貴之, 木下 修, 益澤 明広, 本村 昇, 高本 眞一, 大友 一義, 重枝 崇志, 廣瀬 晶, 加藤 聡, 新家 眞, 藤田 英雄, 安東 治郎, 永井 良三
    日本心臓血管外科学会雑誌 38 Suppl. 263 - 263 (NPO)日本心臓血管外科学会 2009年03月
  • メタボリックシンドロームに関する新見解 冠動脈疾患の日本人患者の転帰に対する糖尿病の影響(New Insights into Metabolic Syndrome The Impact of Diabetes on the Prognosis of Japanese Patients with Coronary Artery Disease)
    Watanabe Shigeyuki, Watanabe Yasuko, Aonuma Kazutaka, Yamazaki Tsutomu, Hayashi Dobun, Kohro Takahide, Okada Yoshihiro, Nagai Ryozo
    Circulation Journal 73 Suppl.I 160 - 160 2009年03月
  • Kansei Uno, Katsu Takenaka, Aya Ebihara, Kan Nawata, Naoto Hayashi, Mika Nagasaki, Makoto Sonoda, Ohno Takayuki, Minoru Ono, Shunei Kyo, Ryozo Nagai, Shinichi Takamoto
    European journal of echocardiography : the journal of the Working Group on Echocardiography of the European Society of Cardiology 10 2 350 - 1 2009年03月 [査読有り][通常論文]
     
    We experienced a case in which live 3D transoesophageal echocardiography (TEE) was found much more valuable than 2D TEE in assessing mitral lesions in circumferential direction and making surgical plans for mitral valve prolapse.
  • 弾性線維性仮性黄色腫に合併し血行再建を繰り返した重症虚血性心疾患の1例
    飯島 史織, 柴田 宗彦, 今井 靖, 都島 健介, 森田 敏宏, 前村 浩二, 山下 尋史, 平田 恭信, 永井 良三
    日本内科学会関東地方会 561回 24 - 24 日本内科学会-関東地方会 2009年03月 [査読有り][通常論文]
  • FRS-087 The Impact of Diabetes on the Prognosis of Japanese Patients with Coronary Artery Disease(FRS18,New Insights into Metabolic Syndrome (H),Featured Research Session (English),The 73rd Annual Scientific Meeting of The Japanese Circulation Society)
    Watanabe, Shigeyuki, Watanabe, Yasuko, Aonuma, Kazutaka, Yamazaki, Tsutomu, Hayashi, Dobun, Kohro, Takahide, Okada, Yoshihiro, Nagai, Ryozo, Investigators, JCAD study
    Circulation journal : official journal of the Japanese Circulation Society 73 0 160  社団法人日本循環器学会 2009年03月 [査読有り][通常論文]
  • Makiko Hongo, Nobukazu Ishizaka, Kyoko Furuta, Naoya Yahagi, Kan Saito, Ryota Sakurai, Gen Matsuzaki, Kazuhiko Koike, Ryozo Nagai
    European Journal of Pharmacology 604 1-3 87 - 92 2009年02月 [査読有り][通常論文]
     
    Accumulation of lipids in the heart may cause cardiac dysfunction in various disorders, such as obesity and diabetes. In the current study, we have investigated whether administration of angiotensin II or norepinephrine induces accumulation of lipids and/or changes in the expression of genes related to lipid metabolism in the rat heart. Lipid deposition was found in myocardial, vascular wall, and perivascular cells of the angiotensin II-infused rat heart, and superoxide generation was increased in these lipid-positive cells. By contrast, intracardiac lipid deposition was not found in the heart of norepinephrine-induced hypertensive rats. Triglyceride content in the heart tissue of angiotensin II-infused rats increased more than 3-fold as compared with untreated controls. Losartan completely, but hydralazine only partially, suppressed the angiotensin II-induced intracardiac lipid deposition and increase in tissue triglyceride content. Administration of angiotensin II upregulated the mRNA expression of sterol regulatory element-binding protein-1c and fatty acid synthase, but downregulated that of uncoupling protein 2 and 3, in a manner dependent on the angiotensin AT1 receptor. Collectively, these results suggest that angiotensin II may be involved in modulating both intracardiac lipid content and lipid metabolism-related gene expression, in part via an angiotensin AT1 receptor-dependent and pressor-independent mechanism. © 2009 Elsevier B.V. All rights reserved.
  • Akihiro Masuzawa, Takayuki Ohno, Shinichi Takamoto, Noboru Motomura, Minoru Ono, Hideo Fujita, Jiro Ando, Toshihiro Morita, Yasunobu Hirata, Ryozo Nagai, Akira Hirose, Takashi Shigeeda, Satoshi Kato, Makoto Araie
    Journal of cardiology 53 1 86 - 93 2009年02月 [査読有り][通常論文]
     
    BACKGROUND: Patients with diabetic retinopathy (DR) have an increased risk of death from coronary heart disease and myocardial infarction. The purpose of this study was to compare the outcomes of revascularization strategies (sirolimus-eluting stent [SES] and coronary artery bypass surgery [CABG]) in patients with DR according to the stage of retinopathy: non-proliferative retinopathy (NPDR) and proliferative retinopathy (PDR). METHODS: From April 2004 until February 2007, 627 patients including 51 NPDR and 62 PDR patients underwent SES implantation. For each retinopathy group, a historical comparison group at the same stages of retinopathy undergoing CABG was selected. Cardiac events were defined as a composite of cardiac death, myocardial infarction, and repeat revascularization. RESULTS: The average follow-up from the time of the initial revascularization was 27.7 ± 8.5 months for NPDR-SES patients, 69.6 ± 36.6 months for NPDR-CABG patients, 26.4 ± 9.7 months for PDR-SES patients, and 68.3 ± 44.2 months for PDR-CABG patients; and Kaplan-Meier estimates of the percentages of events at 24 months were 47.0%, 22.8%, 28.5%, and 26.0%. Kaplan-Meier curves for cardiac events differed significantly between the SES group and the CABG group in NPDR patients (p = 0.04), whereas the curves did not differ significantly between the two groups of PDR patients. The adjusted hazard ratio of SES implantation for cardiac events in the entire group of DR patients was 1.75 (95% confidence interval [CI] 1.02-3.00, p = 0.04). CONCLUSIONS: SES implantation is not a suitable method of revascularization in DR patients, especially in NPDR patients. CABG may become the first-choice revascularization technique for these patients.
  • Daisuke Nagata, Arihiro Kiyosue, Masao Takahashi, Hiroshi Satonaka, Kimie Tanaka, Masataka Sata, Tetsuo Nagano, Ryozo Nagai, Yasunobu Hirata
    Hypertension research : official journal of the Japanese Society of Hypertension 32 2 133 - 9 2009年02月 [査読有り][通常論文]
     
    The inhibition of apoptotic changes in vascular endothelial cells is important for preventing vascular damage from hypoxia. AMP-activated protein kinase (AMPK) has recently been identified as playing a role in vascular protection. Although the chemical reagent 5-aminoimidazole-4-carboxamide-1-beta-D-ribofuranoside (AICAR) has been used to stimulate AMPK activity, AICAR has been associated with several nonspecific reactions. We therefore constructed a new constitutively active mutant of AMPK alpha 1 (NcaAMPK), which lacks the autoinhibitory domain in AMPK alpha 1 and in which threonine 172 has been replaced with aspartate. We investigated whether NcaAMPK has an anti-apoptotic effect in vascular endothelial cells under anoxic conditions. NcaAMPK, or green fluorescent protein (GFP) as a control, was overexpressed in human umbilical vein endothelial cells (HUVECs). After HUVECs were incubated for 40 h under normoxic or anoxic conditions, we examined cell viability, caspase 3/7 activity, and expression and phosphorylation levels of apoptosis-related proteins. Cell viabilities under anoxic conditions were improved in NcaAMPK-overexpressing cells. Anoxia increased caspase 3/7 activity, but NcaAMPK reduced this increase significantly. NcaAMPK overexpression increased protein kinase B/Akt Ser473 and endothelial nitric oxide synthase Ser1177 phosphorylation, but pretreatment with the nitric oxide synthase inhibitor N(G)-nitro-L-arginine methyl ester (L-NAME) did not decrease the viability of NcaAMPK-overexpressing HUVECs. Furthermore, co-expression of a dominant-negative Akt reduced the improvement in cell viability and the suppression of poly (ADP-ribose) polymerase cleavage by NcaAMPK under anoxic conditions. In conclusion, NcaAMPK inhibited anoxia-induced apoptosis in vascular endothelial cells through Akt activation, suggesting that activation of AMPK might protect against ischemic vascular injury.
  • Taku Watanabe, Naoto Kubota, Mitsuru Ohsugi, Tetsuya Kubota, Iseki Takamoto, Masato Iwabu, Motoharu Awazawa, Hisayuki Katsuyama, Chiaki Hasegawa, Kumpei Tokuyama, Masao Moroi, Kaoru Sugi, Toshimasa Yamauchi, Tetsuo Noda, Ryozo Nagai, Yasuo Terauchi, Kazuyuki Tobe, Kohjiro Ueki, Takashi Kadowaki
    The Journal of biological chemistry 284 3 1803 - 12 2009年01月 [査読有り][通常論文]
     
    Rimonabant has been shown to not only decrease the food intake and body weight but also to increase serum adiponectin levels. This increase of the serum adiponectin levels has been hypothesized to be related to the rimonabant-induced amelioration of insulin resistance linked to obesity, although experimental evidence to support this hypothesis is lacking. To test this hypothesis experimentally, we generated adiponectin knock-out (adipo(-/-))ob/ob mice. After 21 days of 30 mg/kg rimonabant, the body weight and food intake decreased to similar degrees in the ob/ob and adipo(-/-)ob/ob mice. Significant improvement of insulin resistance was observed in the ob/ob mice following rimonabant treatment, associated with significant up-regulation of the plasma adiponectin levels, in particular, of high molecular weight adiponectin. Amelioration of insulin resistance in the ob/ob mice was attributed to the decrease of glucose production and activation of AMP-activated protein kinase (AMPK) in the liver induced by rimonabant but not to increased glucose uptake by the skeletal muscle. Interestingly, the rimonabant-treated adipo(-/-)ob/ob mice also exhibited significant amelioration of insulin resistance, although the degree of improvement was significantly lower as compared with that in the ob/ob mice. The effects of rimonabant on the liver metabolism, namely decrease of glucose production and activation of AMPK, were also less pronounced in the adipo(-/-)ob/ob mice. Thus, it was concluded that rimonabant ameliorates insulin resistance via both adiponectin-dependent and adiponectin-independent pathways.
  • Ichiro Manabe, Ryozo Nagai
    The Biology of Krüppel-like Factors 245 - 252 2009年 [査読有り][通常論文]
     
    Recent advances in our understanding of the disease biology of KLFs have spurred considerable interest in their potential to serve as therapeutic targets. Results obtained with small molecules and nucleic acids (e.g., siRNA) targeting KLFs in vitro and in vivo strongly support the feasibility of therapeutic modulation of KLFs for the treatment of cancer as well as cardiovascular and metabolic diseases. Nonetheless, a better understanding of the precise mode of action of KLF in its transcription network, particularly its interaction with other transcription factors and cofactors and its posttranslational modification, would further facilitate development of KLF therapeutics. Moreover, development of improved drug delivery systems would increase the number of diseases that could be targeted by siRNA against KLFs. KLFs have also been used to induce pluripotency in induced pluripotent stem (iPS) cells, suggesting that pharmacological modulation of KLFs may be a useful approach to tailoring iPS cells and their derivatives. © Springer 2009.
  • Hiroaki Sugiyama, Makoto Sahara, Yasushi Imai, Minoru Ono, Koh Okamoto, Ken Kikuchi, Ryozo Nagai
    CARDIOLOGY 114 3 208 - 211 2009年 [査読有り][通常論文]
     
    The Bartonella species have been recently recognized as important causative agents of culture-negative bacterial endocarditis. Antineutrophil cytoplasmic antibodies (ANCAs) have been associated with the spectrum of idiopathic small vessel vasculitis. However, a variety of infections can result in a false-positive ANCA test, and especially subacute bacterial endocarditis (SBE) with the presence of ANCAs occasionally mimics the clinical manifestations of an ANCA-associated vasculitis such as skin purpura and glomerulonephritis. In contrast, noninfectious endocardial involvement is known to be part of the spectrum of the manifestations of the ANCA-associated vasculitis. Therefore, it is crucial to distinguish an ANCA-positive SBE from an ANCA-associated vasculitis with endocardial compromise, because the misdiagnosis of an SBE as an ANCA-associated vasculitis can lead to an inappropriate immunosuppressive therapy with catastrophic consequences. The differential diagnosis is sometimes difficult, especially in the case of culture-negative infective endocarditis with a positive ANCA test. We describe here a case of a culture-negative SBE caused by Bartonella quintana, accompanied with a positive cytoplasmic ANCA test and clinical findings masquerading as ANCA-associated vasculitis. Both a serological test for Bartonella and polymerase chain reaction restriction fragment length polymorphism analysis were helpful for a correct diagnosis and appropriate treatment. Copyright (C) 2009 S. Karger AG, Basel
  • Ryozo Nagai, Ichiro Manabe, Toru Suzuki
    BIOLOGY OF KRUPPEL-LIKE FACTORS 3 - 18 2009年 [査読有り][通常論文]
     
    Kruppel-like transcription factors (KLFs) participate in diverse physiological and pathological processes, such as cell growth, cell differentiation, tumorigenicity, metabolism, inflammation, and tissue remodeling in response to diverse external stress. The importance of KLFs has recently been appreciated as detailed mechanisms of their molecular functions have been rapidly unraveled. However, many questions remain to be addressed: for instance, (1) how is gene expression of KLFs regulated-in a developmental stage-specific manner or in terms of cell-cell interaction; (2) how do KLFs interplay with other cofactors amid the transcriptional network; and (3) need to explore the tertiary structure of KLFs. Given the importance of KLFs in disease biology, extensive investigations on KLFs are expected to lead to identification of therapeutic targets for many diseases.
  • Jun-ichi Suzuki, Mitsuaki Isobe, Ryuichi Morishita, Ryozo Nagai
    JOURNAL OF BIOMEDICINE AND BIOTECHNOLOGY 2009 916514  2009年 [査読有り][通常論文]
     
    Heart transplantation has been broadly performed in humans. However, occurrence of acute and chronic rejection has not yet been resolved. Several inflammatory factors, such as cytokines and adhesion molecules, enhance the rejection. The graft arterial disease (GAD), which is a type of chronic rejection, is characterized by intimal thickening comprised of proliferative smooth muscle cells. Specific treatments that target the attenuation of acute rejection and GAD formation have not been well studied in cardiac transplantation. Recent progress in the nucleic acid drugs, such as antisense oligodeoxynucleotides (ODNs) to regulate the transcription of disease-related genes, has important roles in therapeutic applications. Transfection of cis-element double-stranded DNA, named as "decoy," has been also reported to be a useful nucleic acid drug. This decoy strategy has been not only a useful method for the experimental studies of gene regulation but also a novel clinical strategy. In this paper, we reviewed the experimental results of NF-kappa B, E2F, AP-1, and STAT-1 decoy and other ODNs using the experimental heart transplant models. Copyright (C) 2009 Jun-ichi Suzuki et al.
  • Jun-ichi Suzuki, Mitsuaki Isobe, Ryuichi Morishita, Ryozo Nagai
    MEDIATORS OF INFLAMMATION 2009 494928  2009年 [査読有り][通常論文]
     
    Tea polyphenols known as catechins are key components with many biological functions, including anti-inflammatory, antioxidative, and anticarcinogenic effects. These effects are induced by the suppression of several inflammatory factors including nuclear factor-kappa B (NF-kappa B). While these characteristics of catechins have been well documented, actions of catechins as mediators on inflammation-related cardiovascular diseases have not yet been well investigated. In this article, we reviewed recent papers to reveal the anti-inflammatory effects of catechins in cardiovascular diseases. In our laboratory, we performed oral administration of catechins into murine and rat models of cardiac transplantation, myocarditis, myocardial ischemia, and atherosclerosis to reveal the effects of catechins on the inflammation-induced ventricular and arterial remodeling. From our results, catechins are potent agents for the treatment and prevention of inflammation-related cardiovascular diseases because they are critically involved in the suppression of proinflammatory signaling pathways. Copyright (c) 2009 Jun-ichi Suzuki et al.
  • Kentaro Meguro, Haruko Iida, Haruhito Takano, Toshihiro Morita, Masataka Sata, Ryozo Nagai, Toshiaki Nakajima
    American journal of physiology. Heart and circulatory physiology 296 1 H211-9 - H219 2009年01月 [査読有り][通常論文]
     
    Voltage-gated Na(+) channel currents (I(Na)) are expressed in several types of smooth muscle cells. The purpose of this study was to evaluate the expression of I(Na), its functional role, pathophysiology in cultured human (hASMCs) and rabbit aortic smooth muscle cells (rASMCs), and its association with vascular intimal hyperplasia. In whole cell voltage clamp, I(Na) was observed at potential positive to -40 mV, was blocked by tetrodotoxin (TTX), and replacing extracellular Na(+) with N-methyl-d-glucamine in cultured hASMCs. In contrast to native aorta, cultured hASMCs strongly expressed SCN9A encoding Na(V)1.7, as determined by quantitative RT-PCR. I(Na) was abolished by the treatment with SCN9A small-interfering (si)RNA (P < 0.01). TTX and SCN9A siRNA significantly inhibited cell migration (P < 0.01, respectively) and horseradish peroxidase uptake (P < 0.01, respectively). TTX also significantly reduced the secretion of matrix metalloproteinase-2 6 and 12 h after the treatment (P < 0.01 and P < 0.05, respectively). However, neither TTX nor siRNA had any effect on cell proliferation. L-type Ca(2+) channel current was recorded, and I(Na) was not observed in freshly isolated rASMCs, whereas TTX-sensitive I(Na) was recorded in cultured rASMCs. Quantitative RT-PCR and immunostaining for Na(V)1.7 revealed the prominent expression of SCN9A in cultured rASMCs and aorta 48 h after balloon injury but not in native aorta. In conclusion, these studies show that I(Na) is expressed in cultured and diseased conditions but not in normal aorta. The Na(V)1.7 plays an important role in cell migration, endocytosis, and secretion. Na(V)1.7 is also expressed in aorta after balloon injury, suggesting a potential role for Na(V)1.7 in the progression of intimal hyperplasia.
  • Soichiro Enomoto, Masataka Sata, Daiju Fukuda, Kazuto Nakamura, Ryozo Nagai
    BIOMEDICINE & PHARMACOTHERAPY 63 1 19 - 26 2009年01月 [査読有り][通常論文]
     
    Accumulating evidence suggests that statins have beneficial effects which are independent of their lipid-lowering actions, on vascular cells. Here, we investigated whether the HMG-CoA reductase inhibitor rosuvastatin can inhibit atherosclerotic lesion development with favorable effects on endothelial cells in ApoE-deficient mice. Rosuvastatin rapidly phosphorylated Akt and endothelial nitric oxide synthase ( eNOS) in human endothelial cells. Endothelial cell death induced by serum starvation was significantly inhibited by rosuvastatin ( percent cell death; 45.9 +/- 2.4% vs. 37.3 +/- 1.1%, p < 0.05). Eight-week-old ApoE-deficient mice were orally administered vehicle or rosuvastatin at a dose of 20 mg/kg/day for 24 weeks. There was no significant difference in cholesterol profile. Rosuvastatin preserved endothelial lining at the aortic root (CD31-positive luminal side; 63.8 +/- 2.8% vs. 81.7 +/- 3.9%, p < 0.05). En face Sudan IV staining of aorta revealed that rosuvastatin significantly decreased the atherosclerotic area (21.9 +/- 2.9% vs. 11.9 +/- 1.9%, p < 0.05). Lipid deposition at the atherosclerotic area was also suppressed by rosuvastatin with more stabilized morphologic features as determined by oil red O staining (3.4 +/- 0.4% vs. 1.7 +/- 0.4%, p < 0.05). Our findings indicate that rosuvastatin protects endothelial cells from death with phosphorylation of Akt and eNOS. These effects may contribute, at least in part, to the anti-atherosclerotic effects of rosuvastatin. (C) 2007 Elsevier Masson SAS. All rights reserved.
  • 各種急性運動における血中PTX3の反応について:CRPとの比較
    蔵野美葉, 飯田陽子, 安田智洋, 高野治人, 目黒健太郎, 宇野漢成, 高橋政夫, 福田平, 小栗淳, 加藤昌義, 志賀太郎, 広瀬健, 相良三奈, 前村浩二, 山岨達也, 平田恭信, 芳賀信彦, 永井良三, 中島敏明
    心臓リハビリテーション 14 1 98 - 103 2009年 [査読無し][通常論文]
  • Kenei Shimada, Masatoshi Fujita, Atsushi Tanaka, Ken Yoshida, Satoshi Jisso, Hidemasa Tanaka, Junichi Yoshikawa, Takahide Kohro, Doubun Hayashi, Yoshihiro Okada, Tsutomu Yamazaki, Ryozo Nagai
    Circulation Journal 73 1 78 - 85 2009年 [査読有り][通常論文]
     
    Background: Accumulating evidence indicates that C-reactive protein (CRP) is an independent predictive factor for atherosclerotic vascular disease in Caucasians. Accordingly, this study sought to investigate the relationship between the serum level of CRP and cardiovascular events of Japanese patients with coronary artery disease (CAD). Methods and Results: The Japanese CAD (JCAD) study enrolled 15,628 patients who had significant diameter stenosis (≥75%) in at least 1 coronary artery. Of these, 6,802 patients had their baseline serum CRP data available. Patients were followed up for a mean of 2.7 years (follow-up rate 88.3%). The primary endpoint of the JCAD study was all events. Baseline covariates possibly influencing the event rate were adjusted between the 2 groups with and without elevated serum CRP level. Kaplan-Meier analysis demonstrated a 30% higher all-events rate in patients with a serum level of CRP ≥0.1 mg/dl (P=0.0002). Cox proportional hazard analysis also showed that a serum level of CRP ≥0.1 mg/dl was an independent predictor of all events (P=0.0001), and of cardiac events and cardiac death (P=0.0005). Conclusions: Elevated serum level of CRP is an independent predictor of cardiovascular events in JCAD patients.
  • Hiroaki Okazaki, Masaki Igarashi, Makiko Nishi, Motohiro Sekiya, Makiko Tajima, Satoru Takase, Mikio Takanashi, Keisuke Ohta, Yoshiaki Tamura, Sachiko Okazaki, Naoya Yahagi, Ken Ohashi, Michiyo Amemiya-Kudo, Yoshimi Nakagawa, Ryozo Nagai, Takashi Kadowaki, Jun-ichi Osuga, Shun Ishibashi
    The Journal of biological chemistry 283 48 33357 - 64 2008年11月 [査読有り][通常論文]
     
    Unstable lipid-rich plaques in atherosclerosis are characterized by the accumulation of macrophage foam cells loaded with cholesterol ester (CE). Although hormone-sensitive lipase and cholesteryl ester hydrolase (CEH) have been proposed to mediate the hydrolysis of CE in macrophages, circumstantial evidence suggests the presence of other enzymes with neutral cholesterol ester hydrolase (nCEH) activity. Here we show that the murine orthologue of KIAA1363, designated as neutral cholesterol ester hydrolase (NCEH), is a microsomal nCEH with high expression in murine and human macrophages. The effect of various concentrations of NaCl on its nCEH activity resembles that on endogenous nCEH activity of macrophages. RNA silencing of NCEH decreases nCEH activity at least by 50%; conversely, its overexpression inhibits the CE formation in macrophages. Immunohistochemistry reveals that NCEH is expressed in macrophage foam cells in atherosclerotic lesions. These data indicate that NCEH is responsible for a major part of nCEH activity in macrophages and may be a potential therapeutic target for the prevention of atherosclerosis.
  • IgG4高値を呈した縦隔線維症の1例
    清水 峻志, 稲島 司, 高橋 政夫, 武田 憲文, 山下 尋史, 平田 恭信, 永井 良三
    日本内科学会関東地方会 558回 21 - 21 日本内科学会-関東地方会 2008年11月 [査読有り][通常論文]
  • Enomoto Soichiro, Sata Masataka, Sumi Makoto, Tanaka Kimie, Nakamura Kazuto, Sahara Makoto, Asakura Tetsuo, Nagai Ryozo
    CIRCULATION 118 18 S1053 - S1054 2008年10月 [査読有り][通常論文]
  • Amiya Elsuke, Maemura Koji, Takeda Norihiko, Saito Tetsuya, Shiga Taro, Hosoya Yumiko, Nakao Tomoko, Imai Yasushi, Nagai Ryozo
    CIRCULATION 118 18 S366  2008年10月 [査読有り][通常論文]
  • Saito Tetsuya, Maemura Koji, Takeda Nodhiko, Harada Tomohiro, Shiga Taro, Amiya Eisuke, Nakao Noriko, Hosoya Yumiko, Imai Yasushi, Nagai Ryozo
    CIRCULATION 118 18 S414 - S415 2008年10月 [査読有り][通常論文]
  • Sahara Makoto, Sata Masataka, Morita Toshihiro, Hirata Yasunobu, Nagai Ryozo
    CIRCULATION 118 18 S368  2008年10月 [査読有り][通常論文]
  • Takaoka Minoru, Nagai Ryozo, Sata Masataka
    CIRCULATION 118 18 S515 - S516 2008年10月 [査読有り][通常論文]
  • Ebihara Aya, Takenaka Katsu, Kimura Koichi, Uno Kansei, Fuju Katsuhito, Iwata Hiroshi, Yatomi Yutaka, Sata Masataka, Nagai Ryozo
    CIRCULATION 118 18 S604  2008年10月 [査読有り][通常論文]
  • Kimura Koichi, Takenaka Katsu, Uno Kansei, Ebihara Aya, Fujiu Katsuhito, Iwata Hiroshi, Sata Masataka, Nagai Ryozo
    CIRCULATION 118 18 S992 - S993 2008年10月 [査読有り][通常論文]
  • Enomoto Soichiro, Fukuda Daiju, Tateishi Norifumi, Kitagawa Yoshinori, Nagai Ryozo, Sata Masataka
    CIRCULATION 118 18 S1124  2008年10月 [査読有り][通常論文]
  • Kazuto Nakamura, Nobutaka Koibuchi, Hiroaki Nishimatsu, Yasutomi Higashikuni, Yasunobu Hirata, Kiyotaka Kugiyama, Ryozo Nagai, Masataka Sata
    Hypertension research : official journal of the Japanese Society of Hypertension 31 10 1953 - 61 2008年10月 [査読有り][通常論文]
     
    The renin-angiotensin (Ang) system plays a critical role in the regulation of blood pressure, body fluid, electrolyte homeostasis, and organ remodeling under physiological and pathological conditions. The carboxypeptidase ACE2 is a homologue of angiotensin-converting enzyme (ACE). It has been reported that ACE2-deficient mice develop cardiac dysfunction with increased plasma levels of Ang II. However, the molecular mechanism by which genetic disruption of ACE2 results in heart dysfunction is not fully understood. Here, we generated mice with targeted disruption of the Ace2 gene and compared the cardiovascular function of ACE2(-/y) mice with that of their wild-type littermates. ACE2-deficient mice were viable and fertile and lacked any gross structural abnormalities. Echocardiographic study detected no functional difference between ACE2(-/y) and wild-type mice at 12 weeks of age. Twenty-four-week-old ACE2(-/y) mice displayed significantly enlarged hearts with impaired systolic and diastolic function. The Ang II level was elevated in the plasma and heart of ACE2(-/y) mice. Pharmacological blockade of Ang II type 1 receptor (AT1) with candesartan attenuated the development of cardiac dysfunction in ACE2(-/y) mice. These results suggest that enhanced stimulation of AT1 may play a role in the development of cardiac dysfunction observed in ACE2-deficient mice.
  • Yusuke Shinoda, Naoshi Ogata, Akiro Higashikawa, Ichiro Manabe, Takayuki Shindo, Takashi Yamada, Fumitaka Kugimiya, Toshiyuki Ikeda, Naohiro Kawamura, Yosuke Kawasaki, Kensuke Tsushima, Norifumi Takeda, Ryozo Nagai, Kazuto Hoshi, Kozo Nakamura, Ung-il Chung, Hiroshi Kawaguchi
    The Journal of biological chemistry 283 36 24682 - 9 2008年09月 [査読有り][通常論文]
     
    Although degradation of cartilage matrix has been suggested to be a rate-limiting step for endochondral ossification during skeletal development, little is known about the transcriptional regulation. This study investigated the involvement of KLF5 (Krüppel-like factor 5), an Sp/KLF family member, in the skeletal development. KLF5 was expressed in chondrocytes and osteoblasts but not in osteoclasts. The heterozygous deficient (KLF5+/-) mice exhibited skeletal growth retardation in the perinatal period. Although chondrocyte proliferation and differentiation were normal, cartilage matrix degradation was impaired in KLF5+/- mice, causing delay in replacement of cartilage with bone at the primary ossification center in the embryonic limbs and elongation of hypertrophic chondrocyte layer in the neonatal growth plates. Microarray analyses identified MMP9 (matrix metalloproteinase 9) as a transcriptional target, since it was strongly up-regulated by adenoviral transfection of KLF5 in chondrogenic cell line OUMS27. The KLF5 overexpression caused gelatin degradation by stimulating promoter activity of MMP9 without affecting chondrocyte differentiation or vascular endothelial growth factor expression in the culture of chondrogenic cells; however, in osteoclast precursors, it affected neither MMP9 expression nor osteoclastic differentiation. KLF5 dysfunction by genetic heterodeficiency or RNA interference was confirmed to cause reduction of MMP9 expression in cultured chondrogenic cells. MMP9 expression was decreased in the limbs of KLF5+/- embryos, which was correlated with suppression of matrix degradation, calcification, and vascularization. We conclude that KLF5 causes cartilage matrix degradation through transcriptional induction of MMP9, providing the first evidence that transcriptional regulation of a proteinase contributes to endochondral ossification and skeletal development.
  • Yukari Kamijima, Nobuhiro Ooba, Mitsunori Yagame, Kazuo Samizo, Yoshihiro Shimodozono, Shigeru Kageyama, Shingo Horiguchi, Ryozo Nagai, Tadashi Kusunoki, Kiyoshi Kubota
    Pharmacoepidemiology and drug safety 17 9 904 - 11 2008年09月 [査読有り][通常論文]
     
    PURPOSE: In hypertensive patients with diabetes, antihypertensive therapy is important in reducing the risk of macro- and microvascular complications. In contrast to the guidelines issued by the American Diabetes Association (ADA) in and after 2002, the guidelines issued by the Japanese Society of Hypertension (JSH) in 2000 and 2004 maintained the traditional view that beta-blockers and thiazides should be rated as second-line drugs. However, both sets of guidelines recommended angiotensin converting enzyme inhibitors and angiotensin II receptor blockers (ARBs) as first-line agents for such patients. METHODS: We examined the use of antihypertensives in hypertensive patients with and without diabetes using the prescription data for 1999, 2002 and 2005 from three Japanese university hospitals. RESULTS: When compared with 1999, the proportion of patients with and without diabetes using ARBs was dramatically increased in 2005 from 1.5 to 55% and from 1.5 to 40%, while that of angiotensin converting enzyme inhibitors decreased from 52 to 32% and 35 to 23%, respectively. A relatively stable proportion of patients (around 10% with and without diabetes) used beta-blockers and around 60% of patients with and without diabetes used calcium channel blockers (CCBs) and very few (<5%) used thiazides. CONCLUSIONS: The rapid increase in use of ARBs and under-use of thiazides may be explained by the fee schedule in the Japanese health insurance system. The paucity of large-scale clinical trials may also hinder evaluation of the traditional view of the role of beta-blockers and thiazides in treatment of Japanese patients with diabetes.
  • Hiroshi Iwata, Junya Ako, Ryozo Nagai
    Journal of Invasive Cardiology 20 9 E265 - E268 2008年09月 [査読有り][通常論文]
     
    Stent thrombosis has been recognized as a potentially critical complication in percutaneous coronary intervention. In the bare-metal stent era, stent thrombosis was considered to be an acute or subacute event, occurring within 1 month after stent implantation. Recently, late or very late stent thrombosis after drug-eluting stent implantation has been brought into focus however, the mechanism underlying this potentially fatal event is largely unknown. We report a case of critical late thrombosis 2 years after sirolimus-eluting stent implantation. Detailed serial intravascular ultrasound analyses revealed that late-acquired incomplete stent apposition, accompanied by extensive positive vascular remodeling, was involved in the pathogenesis of the nearly fatal event described in this case.
  • Mofvioviura Shin-Ichi, Yamazaki Tsutomu, Nagai Ryozo
    JOURNAL OF CARDIAC FAILURE 14 7 S172  2008年09月 [査読有り][通常論文]
  • Silvia Parisi, Fabiana Passaro, Luigi Aloia, Ichiro Manabe, Ryozo Nagai, Lucio Pastore, Tommaso Russo
    Journal of cell science 121 Pt 16 2629 - 34 2008年08月 [査読有り][通常論文]
     
    Self-renewal of embryonic stem cells (ESCs) is maintained by a complex regulatory mechanism involving transcription factors Oct3/4 (Pou5f1), Nanog and Sox2. Here, we report that Klf5, a Zn-finger transcription factor of the Kruppel-like family, is involved in ESC self-renewal. Klf5 is expressed in mouse ESCs, blastocysts and primordial germ cells, and its knockdown by RNA interference alters the molecular phenotype of ESCs, thereby preventing their correct differentiation. The ability of Klf5 to maintain ESCs in the undifferentiated state is supported by the finding that differentiation of ESCs is prevented when Klf5 is constitutively expressed. Maintenance of the undifferentiated state by Klf5 is, at least in part, due to the control of Nanog and Oct3/4 transcription, because Klf5 directly binds to the promoters of these genes and regulates their transcription.
  • 糖尿病患者の血行再建術 糖尿病網膜症患者に対する冠動脈血行再建術選択
    益澤 明広, 大野 貴之, 木下 修, 小野 稔, 本村 昇, 高本 眞一, 藤田 英雄, 安東 治郎, 森田 敏弘, 永井 良三
    日本心臓病学会誌 2 Suppl.I 153 - 153 (一社)日本心臓病学会 2008年08月
  • 糖尿病患者の血行再建術 糖尿病網膜症患者に対する早期冠動脈血行再建
    木下 修, 大野 貴之, 益澤 明広, 高本 眞一, 藤田 英雄, 安東 治郎, 永井 良三
    日本心臓病学会誌 2 Suppl.I 153 - 153 (一社)日本心臓病学会 2008年08月
  • Nobukazu Ishizaka, Yuko Ishizaka, George Seki, Ryozo Nagai, Minoru Yamakado, Kazuhiko Koike
    Hepatology Research 38 8 775 - 783 2008年08月 [査読有り][通常論文]
     
    Aim: Previous studies have shown that hepatitis B virus (HBV) and hepatitis C virus (HCV) infection may be associated with glomerulonephritis. Methods: In the current study, we investigated the possible association between HBV/HCV infection, estimated GFR (eGFR) and albuminuria by analyzing cross-sectional data from individuals undergoing general health screening. Results: Of 12 535 individuals enrolled, 130 (1.0%) and 72 (0.6%) tested positive for HBV surface antigen and HCV core antigen, respectively. In comparison with hepatitis-negative individuals, the prevalence of low eGFR and albuminuria was significantly greater in individuals with HCV infection, but not in those with HBV infection. Logistic regression analysis adjusted for age, sex, systolic blood pressure and fasting plasma glucose showed that HCV infection was positively associated with low eGFR (odds ratio 1.63 [95% CI 0.95-2.80, P = 0.077]) and with albuminuria (odds ratio 2.00 [95% CI 1.06-3.76, P = 0.003]). By contrast, prevalence of neither low eGFR nor albuminuria was greater in individuals with HBV infection than in hepatitis-negative subjects. Further adjustment for either HOMA-IR or serum alanine aminotransferase levels abolished the statistical significance in the association between HCV infection and albuminuria. Conclusion: Our data suggest that although both HCV and HBV infection are associated with increased insulin resistance, the different viruses may have different impacts on chronic kidney disease among Japanese individuals undergoing general health screening. © 2008 The Japan Society of Hepatology.
  • 圧負荷肥大心モデルにおける転写因子KLF5の役割
    武田 憲文, 真鍋 一郎, 永井 良三
    日本心臓病学会誌 2 Suppl.I 250 - 250 (一社)日本心臓病学会 2008年08月 [査読有り][通常論文]
  • Motohiro Sekiya, Jun-Ichi Osuga, Naoya Yahagi, Hiroaki Okazaki, Yoshiaki Tamura, Masaki Igarashi, Satoru Takase, Kenji Harada, Sachiko Okazaki, Yoko Iizuka, Ken Ohashi, Hiroaki Yagyu, Mitsuyo Okazaki, Takanari Gotoda, Ryozo Nagai, Takashi Kadowaki, Hitoshi Shimano, Nobuhiro Yamada, Shun Ishibashi
    Journal of lipid research 49 8 1829 - 38 2008年08月 [査読有り][通常論文]
     
    Hormone-sensitive lipase (HSL) regulates the hydrolysis of acylglycerol and cholesteryl ester (CE) in various organs, including adipose tissues. However, the hepatic expression level of HSL has been reported to be almost negligible. In the present study, we found that mice lacking both leptin and HSL (Lep(ob/ob)/HSL(-/-)) showed massive accumulation of CE in the liver compared with Lep(ob/ob)/HSL(+/+) mice, while triacylglycerol (TG) accumulation was modest. Similarly, feeding with a high-cholesterol diet induced hepatic CE accumulation in HSL(-/-) mice. Supporting these observations, we detected significant expression of protein as well as mRNA of HSL in the liver. HSL(-/-) mice showed reduced activity of CE hydrolase, but not of TG lipase, in the liver compared with wild-type mice. Furthermore, we confirmed the expression of HSL in viable parenchymal cells isolated from wild-type mice. The hepatocytes from HSL(-/-) mice showed reduced activity of CE hydrolase and contained more CE than those from HSL(+/+) mice even without the incubation with lipoproteins. Incubation with LDL further augmented the accumulation of CE in the HSL-deficient hepatocytes. From these results, we conclude that HSL is involved in the hydrolysis of CE in hepatocyes.
  • Yasunobu Hirata, Arihiro Kiyosue, Masao Takahashi, Hiroshi Satonaka, Daisuke Nagata, Masataka Sata, Etsu Suzuki, Ryozo Nagai
    Current cardiology reviews 4 3 198 - 202 2008年08月 [査読有り][通常論文]
     
    It has been established that patients with chronic kidney disease (CKD) suffer from frequent cardiovascular events. On the other hand, recent studies suggest that renal damage tends to worsen in patients with cardiovascular diseases (CVD). Although the mechanisms for the cardiorenal association are unclear, the presence of arteriosclerotic risk factors common to both CVD and CKD is important. In arteriosclerosis, vascular derangement progresses not only in the heart but also in the kidney. In addition, heart failure, cardiac catheterization and hesitation of medical treatments due to renal dysfunction may explain the progression of renal damage. Therefore, the goal of treatments is a total control of arteriosclerotic risk factors. Medication should be selected among agents with protective effects on both heart and kidney. It is important to always consider the presence of CKD for the treatment of the cardiovascular disease and strictly control the risk factors.
  • Naoto Kubota, Tetsuya Kubota, Shinsuke Itoh, Hiroki Kumagai, Hideki Kozono, Iseki Takamoto, Tomoka Mineyama, Hitomi Ogata, Kumpei Tokuyama, Mitsuru Ohsugi, Takayoshi Sasako, Masao Moroi, Kaoru Sugi, Shigeru Kakuta, Yoichiro Iwakura, Tetsuo Noda, Shin Ohnishi, Ryozo Nagai, Kazuyuki Tobe, Yasuo Terauchi, Kohjiro Ueki, Takashi Kadowaki
    Cell metabolism 8 1 49 - 64 2008年07月 [査読有り][通常論文]
     
    Insulin receptor substrate (Irs) mediates metabolic actions of insulin. Here, we show that hepatic Irs1 and Irs2 function in a distinct manner in the regulation of glucose homeostasis. The PI3K activity associated with Irs2 began to increase during fasting, reached its peak immediately after refeeding, and decreased rapidly thereafter. By contrast, the PI3K activity associated with Irs1 began to increase a few hours after refeeding and reached its peak thereafter. The data indicate that Irs2 mainly functions during fasting and immediately after refeeding, and Irs1 functions primarily after refeeding. In fact, liver-specific Irs1-knockout mice failed to exhibit insulin resistance during fasting, but showed insulin resistance after refeeding; conversely, liver-specific Irs2-knockout mice displayed insulin resistance during fasting but not after refeeding. We propose the concept of the existence of a dynamic relay between Irs1 and Irs2 in hepatic insulin signaling during fasting and feeding.
  • Kiyotaka Watanabe, Shin Ohnishi, Ichiro Manabe, Ryozo Nagai, Takashi Kadowaki
    Gastroenterology 135 1 309 - 12 2008年07月 [査読有り][通常論文]
  • Toru Suzuki, Alessandro Distante, Antonella Zizza, Santi Trimarchi, Massimo Villani, Jorge Antonio Salerno Uriarte, Luigi de Luca Tupputi Schinosa, Attilio Renzulli, Federico Sabino, Richard Nowak, Robert Birkhahn, Judd E Hollander, Francis Counselman, Eduardo Bossone, Kim Eagle
    European heart journal 29 11 1439 - 45 2008年06月 [査読有り][通常論文]
     
    AIMS: The early diagnosis of acute aortic dissection (AD) remains challenging. We sought to determine the utility of the troponin-like protein of smooth muscle, calponin, as a diagnostic biomarker of acute AD. METHODS AND RESULTS: Immunoassays against calponin (acidic, basic, and neutral isoforms) were developed and the levels were compared in a convenience sample of 59 patients with radiographically proven AD [34 males, age 59 +/- 15 (SD) years] vs. 158 patients suspected of having AD at presentation (116 males, age 63 +/- 15 years) but whose final diagnosis was not AD. Basic calponin, which is the most specific and abundant in smooth muscle, and acidic calponin, respectively, showed greater than two-fold and three-fold elevations in patients with acute AD. Diagnostic performance as determined by receiver-operating characteristics curve analysis showed that both acidic and basic calponin have the potential to detect AD in the first 24 h [respective areas under the curve (AUCs) 0.63 and 0.58], with superior performance of basic calponin (when compared with acidic) in the initial 6 h (respective AUCs 0.63 and 0.67). CONCLUSION: Circulating calponin levels were elevated in acute AD compared with controls. These biomarkers have the potential for use as an early diagnostic biomarker for acute AD.
  • Masao Takahashi, Etsu Suzuki, Ryo Takeda, Shigeyoshi Oba, Hiroaki Nishimatsu, Kenjiro Kimura, Tetsuo Nagano, Ryozo Nagai, Yasunobu Hirata
    American journal of physiology. Heart and circulatory physiology 294 6 H2879-88 - H2888 2008年06月 [査読有り][通常論文]
     
    We examined whether ANG II and TNF-alpha cooperatively induce vascular inflammation using the expression of monocyte chemoattractant protein (MCP)-1 as a marker of vascular inflammation. ANG II and TNF-alpha stimulated MCP-1 expression in a synergistic manner in vascular smooth muscle cells. ANG II-induced MCP-1 expression was potently inhibited to a nonstimulated basal level by blockade of the p38-dependent pathway but only partially inhibited by blockade of the NF-kappaB-dependent pathway. In contrast, TNF-alpha-induced MCP-1 expression was potently suppressed by blockade of NF-kappaB activation but only modestly suppressed by blockade of p38 activation. ANG II- and TNF-alpha-induced activation of NF-kappaB- and p38-dependent pathways was partially inhibited by pharmacological inhibitors of ROS production. Furthermore, ANG II- and TNF-alpha-stimulated MCP-1 expression was partially suppressed by ROS inhibitors. We also examined whether endogenous ANG II and TNF-alpha cooperatively promote vascular inflammation in vivo using a wire injury model of the rat femoral artery. Blockade of both ANG II and TNF-alpha further suppressed neointimal formation, macrophage infiltration, and MCP-1 expression in an additive manner compared with blockade of ANG II or TNF-alpha alone. These results suggested that ANG II and TNF-alpha synergistically stimulate MCP-1 expression via the utilization of distinct intracellular signaling pathways (p38- and NFkappaB-dependent pathways) and that these pathways are activated in ROS-dependent and -independent manners. These results also suggest that ANG II and TNF-alpha cooperatively stimulate vascular inflammation in vivo as well as in vitro.
  • Ryo Takeda, Etsu Suzuki, Masao Takahashi, Shigeyoshi Oba, Hiroaki Nishimatsu, Kenjiro Kimura, Tetsuo Nagano, Ryozo Nagai, Yasunobu Hirata
    American journal of physiology. Heart and circulatory physiology 294 6 H2871-8 - H2878 2008年06月 [査読有り][通常論文]
     
    It is well known that excessive intake of sodium chloride (sodium) is a risk factor for cardiovascular disease because it raises blood pressure. However, sodium loading reportedly promotes cardiovascular disease independently of its effect on blood pressure. To examine the mechanisms by which sodium loading promotes vascular inflammation independently of its effect on blood pressure, we examined the role of calcineurin in sodium loading-induced vascular inflammation using a wire injury model of the rat femoral artery. Calcineurin mRNA expression in the wire-injured femoral artery was significantly higher in sodium-loaded normotensive rats, such as Wistar-Kyoto (WKY) rats, than that in control WKY rats. Neointimal formation was also significantly enhanced in sodium-loaded WKY rats compared with control WKY rats. Gene transfer of an adenovirus expressing a dominant negative mutant of calcineurin (AdCalADeltaC92Q) significantly suppressed neointimal formation in sodium-loaded WKY rats to a level similar to that observed in control WKY rats. Calcineurin expression and neointimal formation were more significantly enhanced in hypertensive rats, such as spontaneously hypertensive rats (SHRs), than those in control WKY rats. AdCalADeltaC92Q infection significantly suppressed neointimal formation in SHRs to a level similar to that observed in control WKY rats. These results suggest that sodium loading promotes neointimal formation, even in normotensive rats, and that hypertension further stimulates neointimal formation. These results also suggest that calcineurin plays a pivotal role in this process.
  • Gen Matsuzaki, Nobukazu Ishizaka, Kyoko Furuta, Makiko Hongo, Kan Saito, Ryota Sakurai, Kazuhiko Koike, Ryozo Nagai
    EUROPEAN JOURNAL OF PHARMACOLOGY 587 1-3 237 - 242 2008年06月 [査読有り][通常論文]
     
    Although antihypertensive drugs confer improvement in endothelial dysfunction and protection from atherogenesis in hypertension, different classes of antihypertensive drugs may elicit different degrees of vasculoprotective effects. We have investigated the effects of a long-acting calcium antagonist, benidipine, and an angiotensin AT(1) receptor antagonist, losartan, on the vascular damage observed in OLETF rats, an animal model of metabolic syndrome. At 34 weeks of age, OLETF rats were treated with either benidipine (3 mg/kg/day, per os) or losartan (25 mg/kg/day, per os) for 8 weeks. The extent of blood pressure reduction, restoration endothelium-dependent aortic relaxation, and elevation of serum nitrite/nitrate concentration did not differ significantly between benidipine- and losartan-treated OLETF rats. Benidipine and losartan also reduced the aortic expression of transforming growth factor-beta 1 mRNA and thickening of the vascular wall to a similar extent. Increased cardiac fibrosis was also inhibited by both benidipine and losartan. These data suggest that, when used in an antihypertensive dose, benidipine is as effective as losartan in restoring vascular endothelial function and in suppressing of cardiovascular remodeling in an animal model of metabolic syndrome. (C) 2008 Elsevier B.V. All rights reserved.
  • Oishi Y, Manabe I, Tobe K, Ohsugi M, Kubota T, Fujiu K, Maemura K, Kubota N, Kadowaki T, Nagai R
    Nature medicine 14 6 656 - 66 6 2008年06月 [査読有り][通常論文]
     
    Obesity and metabolic syndrome are increasingly recognized as major risk factors for cardiovascular disease. Herein we show that Krüppel-like transcription factor 5 (KLF5) is a crucial regulator of energy metabolism. Klf5(+/-) mice were resistant to high fat-induced obesity, hypercholesterolemia and glucose intolerance, despite consuming more food than wild-type mice. This may in part reflect their enhanced energy expenditure. Expression of the genes involved in lipid oxidation and energy uncoupling, including those encoding carnitine-palmitoyl transferase-1b (Cpt1b) and uncoupling proteins 2 and 3 (Ucp2 and Ucp3), was upregulated in the soleus muscles of Klf5(+/-) mice. Under basal conditions, KLF5 modified with small ubiquitin-related modifier (SUMO) proteins was associated with transcriptionally repressive regulatory complexes containing unliganded peroxisome proliferator-activated receptor-delta (PPAR-delta) and co-repressors and thus inhibited Cpt1b, Ucp2 and Ucp3 expression. Upon agonist stimulation of PPAR-delta, KLF5 was deSUMOylated, and became associated with transcriptional activation complexes containing both the liganded PPAR-delta and CREB binding protein (CBP). This activation complex increased the expression of Cpt1b, Ucp2 and Ucp3. Thus, SUMOylation seems to be a molecular switch affecting function of KLF5 and the transcriptional regulatory programs governing lipid metabolism.
  • Nanae Kada, Toru Suzuki, Kenichi Aizawa, Yoshiko Munemasa, Takayoshi Matsumura, Daigo Sawaki, Ryozo Nagai
    FEBS letters 582 12 1755 - 60 2008年05月 [査読有り][通常論文]
     
    We show that transcription factor Krüppel-like factor 5 (KLF5), which is important in cardiovascular remodeling, interacts with retinoic acid receptor-alpha (RARalpha) to regulate downstream gene expression. Here, we investigated whether acyclic retinoid (ACR) regulates KLF5 and inhibits vascular remodeling. Co-immunoprecipitation and pull-down binding assay showed that ACR attenuates functional interaction of KLF5 and RARalpha. ACR affects KLF5 functions by regulating transactivation of platelet-derived growth factor A (PDGF-A) chain. ACR may be a new vascular therapy to target KLF5 in cardiovascular pathology.
  • M Okamoto, M Ohara-Imaizumi, N Kubota, S Hashimoto, K Eto, T Kanno, T Kubota, M Wakui, R Nagai, M Noda, S Nagamatsu, T Kadowaki
    Diabetologia 51 5 827 - 35 2008年05月 [査読有り][通常論文]
     
    AIMS/HYPOTHESIS: A decrease in plasma adiponectin levels has been shown to contribute to the development of diabetes. However, it remains uncertain whether adiponectin plays a role in the regulation of insulin secretion. In this study, we investigated whether adiponectin may be involved in the regulation of insulin secretion in vivo and in vitro. METHODS: The effect of adiponectin on insulin secretion was measured in vitro and in vivo, along with the effects of adiponectin on ATP generation, membrane potentials, Ca2+ currents, cytosolic calcium concentration and state of 5'-AMP-activated protein kinase (AMPK). In addition, insulin granule transport was measured by membrane capacitance and total internal reflection fluorescence (TIRF) analysis. RESULTS: Adiponectin significantly stimulated insulin secretion from pancreatic islets to approximately 2.3-fold the baseline value in the presence of a glucose concentration of 5.6 mmol/l. Although adiponectin had no effect on ATP generation, membrane potentials, Ca2+ currents, cytosolic calcium concentrations or activation status of AMPK, it caused a significant increase of membrane capacitance to approximately 2.3-fold the baseline value. TIRF analysis revealed that adiponectin induced a significant increase in the number of fusion events in mouse pancreatic beta cells under 5.6 mmol/l glucose loading, without affecting the status of previously docked granules. Moreover, intravenous injection of adiponectin significantly increased insulin secretion to approximately 1.6-fold of baseline in C57BL/6 mice. CONCLUSIONS/INTERPRETATION: The above results indicate that adiponectin induces insulin secretion in vitro and in vivo.
  • Tadashi Yamazaki, Jun-ichi Suzuki, Ryoichi Shimamoto, Taeko Tsuji, Yuki Ohmoto-Sekine, Toshihiro Morita, Hiroshi Yamashita, Junko Honye, Ryozo Nagai, Shuhei Komatsu, Masaaki Akahane, Kuni Ohtomo
    Radiography 14 2 98 - 104 2008年05月 [査読有り][通常論文]
     
    Purpose: Hounsfield CT values across coronary CT angiograms constitute CT value-spatial profile curves. These CT profile curves are independent of window settings, and therefore, parameters derived from the curves can be used for objective anatomic analyses. Applicability of parameters derived from the curves to quantification of coronary in-stent patency has not yet been evaluated. Methods: Twenty-five CT value-spatial profile curves were delineated from 10 consecutive coronary stents to test correlation between the curve derived parameter (i.e., the minimum extreme value normalized by dividing by the maximum value of the curves obtained at neighboring outside of stents) and three intravascular ultrasound (IVUS) parameters. Results: Correlation coefficients between normalized minimum extreme value of CT value-spatial profile curves and three IVUS parameters (such as patent cross-sectional in-stent area, the percentage of patent cross-sectional in-stent area, and coronary artery intra-stent diameter) were 0.65 (p < 0.01), 0.44 (p < 0.05) and 0.51 (p < 0.05), respectively. Conclusions: CT parameters defined on Hounsfield CT value-spatial profile curves correlated significantly with IVUS parameters for quantitative coronary in-stent patency. A new approach with CT coronary angiography is therefore indicated for the noninvasive assessment of in-stent re-stenosis. © 2007 The College of Radiographers.
  • Hajime Fujimoto, Jun-Ichi Taguchi, Yasushi Imai, Seiji Ayabe, Hideki Hashimoto, Hisae Kobayashi, Ken Ogasawara, Tadanori Aizawa, Minoru Yamakado, Ryozo Nagai, Minoru Ohno
    European Heart Journal 29 10 1267 - 1274 2008年05月 [査読有り][通常論文]
     
    Aims: Oxidative damage promotes atherosclerosis. Manganese superoxide dismutase (MnSOD) is an antioxidant enzyme localized in mitochondria. We investigated the associations of the MnSOD polymorphism (valine-to-alanine in the mitochondrial-targeting domain) with its activity in leukocytes, with macrophage apoptosis by oxidized low-density lipoprotein (oxLDL), and with coronary artery disease (CAD). Methods and results: Blood samples were taken from 50 healthy subjects. The mitochondrial MnSOD activities in leukocytes were 542.4 ± 71.6 U/mg protein (alanine/alanine, n = 2), 302.0 ± 94.9 U/mg protein (alanine/valine, n = 12), and 134.0 ± 67.1 U/mg protein (valine/valine, n = 36 P < 0.0001 for non-valine/valine vs. valine/valine). Macrophages were treated with oxLDL. After incubation, the percentages of apoptotic macrophages were 48.6 ± 3.6% (alanine/alanine), 78.6 ± 9.8% (alanine/valine), and 87.5 ± 7.0% (valine/valine) (P < 0.0001, non-valine/valine vs. valine/valine). The association of the MnSOD polymorphism with CAD was investigated using blood samples collected from 498 CAD patients and 627 healthy subjects the alanine allele was found to reduce the risk of CAD and acute myocardial infarction (AMI). Conclusion: Our data indicate that the alanine variant of signal peptide increases the mitochondrial MnSOD activity, protects macrophages against the oxLDL-induced apoptosis, and reduces the risk of CAD and AMI. © The Author 2007.
  • KLF5は心血管代謝系の小胞体ストレス応答において重要な役割を果たす
    江口 航生, 真鍋 一郎, 大石 由美子, 沈 華, 松本 佐保姫, 藤生 克仁, 武田 憲文, 大杉 満, 戸辺 一之, 門脇 孝, 永井 良三
    糖尿病 51 Suppl.1 S - 318 (一社)日本糖尿病学会 2008年04月 [査読有り][通常論文]
  • Miwa Matsumoto, Masataka Sata, Daiju Fukuda, Kimie Tanaka, Masaaki Soma, Yasunobu Hirata, Ryozo Nagai
    Atherosclerosis 197 2 524 - 33 2008年04月 [査読有り][通常論文]
     
    Accumulating evidence demonstrates that dietary intake of n-3 polyunsaturated fatty acids (PUFAs) is associated with reduced incidence of cardiovascular events. However, the molecular mechanisms by which n-3 PUFAs prevent atherosclerosis are not fully understood. Here, we examined the effect of eicosapentaenoic acid (EPA), a major n-3 PUFA, on the pathogenesis of atherosclerosis in ApoE-deficient mice. Five-week-old ApoE-deficient male mice were fed on western-type diet supplemented with 5% (w/w) EPA (EPA group, n=7) or not (control group, n=5) for 13 weeks. An analysis of the fatty acid composition of liver homogenates revealed a marked increase of the n-3 PUFA content in the EPA group (n-3/n-6 ratio: 0.20+/-0.01 vs. 2.5+/-0.2, p<0.01). En face Sudan IV staining of the aorta and oil red O-staining of the aortic sinus revealed that EPA significantly suppressed the development of atherosclerotic lesions. We also observed anti-atherosclerotic effects of EPA in LDL-receptor-deficient mice. The lesions of the EPA group contained more collagen (19.6+/-2.4% vs. 32.9+/-3.9%, p<0.05) and smooth muscle cells (1.3+/-0.2% vs. 3.6+/-0.8%, p<0.05) and less macrophages (32.7+/-4.1% vs. 14.7+/-2.0%, p<0.05). Pretreatment with EPA attenuated the up-regulation of VCAM-1, ICAM-1 and MCP-1 in HUVECs as well as the expression of MMP-2 and MMP-9 in macrophage-like cells induced by TNF-alpha. The anti-inflammatory effects of EPA were abrogated when the expression of peroxisome proliferator-activated receptor alpha (PPARalpha) was suppressed. EPA may potentially reduce and stabilize atherosclerotic lesions through its anti-inflammatory effects.
  • Takahide Kohro, Yuji Furui, Naohiro Mitsutake, Ryo Fujii, Hiroyuki Morita, Shinya Oku, Kazuhiko Ohe, Ryozo Nagai
    International Heart Journal 49 2 193 - 203 2008年03月 [査読有り][通常論文]
     
    Similar to the healthcare systems in other industrialized countries, the Japanese healthcare system is facing the problem of increasing medical expenditure. In Japan, this situation may be primarily attributed to advanced technological developments, an aging population, and increasing patient demand. Japan also faces the problem of a declining youth population due to a low birth rate. Taken together, these problems present the healthcare system with a very difficult financial situation. Several reforms have been undertaken to contain medical expenditure, such as increasing employee copayment for health insurance from 10% to 20% in 1997 and from 20% to 30% in 2003 in order to curb unnecessary visits to medical institutions. Since the aging of the Japanese population is inevitable, a suitable method to contain medical expenditure may be to screen individuals who are likely to develop lifestyle-related diseases and conduct early intervention programs for them to prevent the development of diseases such as myocardial infarction or stroke that are costly to treat. If this goal is attained, it may contribute to the containment of medical expenditure as well as to improving the quality of life of the elderly. Therefore, the Japanese Ministry of Health, Labor and Welfare has decided to introduce a nationwide health screening and intervention program specifically targeting the metabolic syndrome commencing April 2008. Here, we discuss (1) the background of the Japanese healthcare system and the problems facing it, (2) the underlying objective and details of the new screening program, and (3) the expected impact of the program.
  • Makoto Sonoda, Katsu Takenaka, Kansei Uno, Aya Ebihara, Ryozo Nagai
    ECHOCARDIOGRAPHY-A JOURNAL OF CARDIOVASCULAR ULTRASOUND AND ALLIED TECHNIQUES 25 3 242 - 248 2008年03月 [査読有り][通常論文]
     
    A bicuspid aortic valve (BAV) often causes aortic stenosis (AS) or regurgitation (AR). In 54 patients with a BAV (48 +/- 16 years), transthoracic and transesophageal echo were performed to measure aortic annulus diameter (AAD), to evaluate the severity of aortic valve disease (AVD) and to calculate the area eccentricity index (AEI) of a BAV defined as a ratio of the larger aortic cusp area to a smaller aortic cusp area. By multiple linear regression analysis, the severity of AR correlated significantly with the AAD (r = 0.38) and AEI (r = 0.35) (P < 0.05) and that of AS correlated significantly with the AAD (r = -0.40) and AEI (r = 0.34) (P < 0.05). Thirty-six patients showed anteroposteriorly (A-P) located BAVs and 18 patients showed right-left (R-L) located BAVs. The AAD was larger in A-P type than in R-L type (15 +/- 3 vs 13 +/- 2 mm/BSA, P < 0.05) and there was no difference in the age and AEI between the two groups. AR was more severe in A-P type than in R-L type while AS was more severe in R-L type than in A-P type (P < 0.05). Twenty-nine patients showed raphes. The AEI was larger in raphe (+) type than in raphe (-) type (1.83 +/- 0.53 vs 1.51 +/- 0.47, P < 0.05) and there was no difference in the AAD and severity of AVD between the two groups. In conclusion, a BAV with larger aortic annulus or A-P located will tend to cause AR while a BAV with smaller aortic annulus or R-L located will tend to cause AS.
  • Nobukazu Ishizaka, Yuko Ishizaka, Ei-Ichi Toda, Hiroji Shimomura, Kazuhiko Koike, George Seki, Ryozo Nagai, Minoru Yamakado
    HYPERTENSION RESEARCH 31 3 485 - 492 2008年03月 [査読有り][通常論文]
     
    Cigarette smoking may affect urinary albumin excretion and the glomerular filtration rate in both diabetic and nondiabetic subjects. Here we investigated the association between smoking and decreased or elevated glomerular filtration rate (GFR) and albuminuria by analyzing data from 7,078 Japanese men who had undergone a general health screening between 2005 and 2006. GFR was estimated with the Modified Diet in Renal Disease (MDRD) equation, and low estimated GFR (eGFR) and elevated eGFR were defined, respectively, as eGFR <60 and >90.7 mL/min/1.73 m(2). Albuminuria was considered present when the urinary albumin excretion ratio (UAER), expressed as mg/g creatinine, was >= 30 mg/g. Multivariate logistic regression analysis showed that current smoking was associated inversely with low eGFR, and positively with albuminuria and elevated eGFR. The association between current smoking and low or elevated GFR was dependent on the number of cigarettes smoked per day. Former smoking was also significantly inversely associated with low eGFR, but the association between former smoking and albuminuria or elevated eGFR was not significant, even in individuals who had stopped smoking less than 1 year before. These data suggest that cigarette smoking may increase the prevalence of albuminuria and elevated eGFR or hyperfiltration, traits that might be reversed by smoking cessation. Although this concept should be verified by future longitudinal studies, our data suggest that we may need to take into account an individual's smoking status when assessing the presence or absence of chronic kidney disease because cigarette smoking may transiently increase eGFR.
  • Yoshiko Munemasa, Toru Suzuki, Kenichi Aizawa, Saku Miyamoto, Yasushi Imai, Takayoshi Matsumura, Masami Horikoshi, Ryozo Nagai
    Molecular and cellular biology 28 3 1171 - 81 2008年02月 [査読有り][通常論文]
     
    Regulation of chromatin in eukaryotic transcription requires histone-modifying enzymes, nucleosome remodeling complexes, and histone chaperones. Specific regulation of histone incorporation/eviction by histone chaperones on the promoter (e.g., region specific) is still poorly understood. In the present study, we show that direct and functional interaction of histone chaperone and DNA-binding transcription factor leads to promoter region-specific histone incorporation and inhibition of histone acetylation. We report here that the DNA-binding transcription factor Krüppel-like factor 5 (KLF5) interacts with the novel histone chaperone acidic nuclear phosphoprotein 32B (ANP32B), leading to transcriptional repression of a KLF5-downstream gene. We further show that recruitment of ANP32B onto the promoter region requires KLF5 and results in promoter region-specific histone incorporation and inhibition of histone acetylation by ANP32B. Extracellular stimulus (e.g., phorbol ester) regulates this mechanism in the cell. Collectively, we have identified a novel histone chaperone, ANP32B, and through analysis of the actions of this factor show a new mechanism of promoter region-specific transcriptional regulation at the chromatin level as mediated by the functional interaction between histone chaperone and DNA-binding transcription factor.
  • Yasutomi Higashikuni, Nobukazu Ishizaka, Yuko Ishizaka, Ei-ichi Toda, Ryozo Nagai, Minoru Yamakado
    HYPERTENSION RESEARCH 31 2 213 - 219 2008年02月 [査読有り][通常論文]
     
    In hypertensive subjects, it has been demonstrated that the lower the blood pressure, the lower the incidence of chronic kidney disease (CKD). However, whether this relationship holds true in individuals without hypertension-that is, in individuals with a blood pressure <140/90 mmHg-remains unknown. This study was performed to assess the relationship between blood pressure and CKD in a Japanese population without hypertension. Among 13,007 Japanese participants in a general health screening, 9,596 (5,691 men and 3,905 women) were found to have either normal blood pressure or prehypertension, and were enrolled in this study. We categorized these individuals' blood pressure into six classes: BP-Cl, <90/<65 mmHg; BPC2, 90-100/65-70 mmHg; BP-C3, 100-110/70-75 mmHg; BP-C4, 110-120/75-80 mmHg; BP-C5, 120-130/80-85 mmHg; and BP-C6, 130-140/85-90 mmHg. Albuminuria was defined as a urinary albumin excretion ratio of >= 30 mg/g. Low estimated glomerular filtration rate (eGFR) was defined as eGFR <60 mL/min/1.73 m(2). In men, when BP-C3 was used as a reference, multivariate logistic regression analysis adjusted for age, body mass index, serum lipid profiles, fasting plasma glucose and smoking status showed that BP-Cl, BP-C2, BP-C4, BP-C5 and BP-C6 were associated with albuminuria with an adjusted odds ratio of 1.85 (0.53-6.46), 1.22 (0.59-2.51), 1.62 (1.01-2.59), 2.57 (1.64-4.02), and 3.81 (2.44-5.96). In women, the adjusted odds ratios of the risk for albuminuria in BP-C2, BP-C3, BP-C4, BP-C5 and BP-C6, as compared with BP-C1 as a reference, were 1.83 (0.70-4.79), 2.13 (0.84-5.42), 2.80 (1.10-7.14), 2.59 (0.99-6.78), and 3.99 (1.50-10.64). Blood pressure was not significantly associated with low eGFR in either gender. The risk for albuminuria was significantly greater when blood pressure exceeded 110/75 mmHg in both genders.
  • Satoshi Nishimura, Ichiro Manabe, Mika Nagasaki, Kinya Seo, Hiroshi Yamashita, Yumiko Hosoya, Mitsuru Ohsugi, Kazuyuki Tobe, Takashi Kadowaki, Ryozo Nagai, Seiryo Sugiura
    The Journal of clinical investigation 118 2 710 - 21 2008年02月 [査読有り][通常論文]
     
    To assess physiological and pathophysiological events that involve dynamic interplay between multiple cell types, real-time, in vivo analysis is necessary. We developed a technique based on confocal laser microscopy that enabled us to analyze and compare the 3-dimensional structures, cellular dynamics, and vascular function within mouse lean and obese adipose tissue in vivo with high spatiotemporal resolution. We found increased leukocyte-EC-platelet interaction in the microcirculation of obese visceral adipose tissue in ob/ob and high-fat diet-induced obese mice. These changes were indicative of activation of the leukocyte adhesion cascade, a hallmark of inflammation. Local platelet activation in obese adipose tissue was indicated by increased P-selectin expression and formation of monocyte-platelet conjugates. We observed upregulated expression of adhesion molecules on macrophages and ECs in obese visceral adipose tissue, suggesting that interactions between these cells contribute to local activation of inflammatory processes. Furthermore, administration of anti-ICAM-1 antibody normalized the cell dynamics seen in obese visceral fat. This imaging technique to analyze the complex cellular interplay within obese adipose tissue allowed us to show that visceral adipose tissue obesity is an inflammatory disease. In addition, this technique may prove to be a valuable tool to evaluate potential therapeutic interventions.
  • Kimie Tanaka, Masataka Sata, Takeshi Natori, Joo-Ri Kim-Kaneyama, Kiyoshi Nose, Motoko Shibanuma, Yasunobu Hirata, Ryozo Nagai
    FASEB journal : official publication of the Federation of American Societies for Experimental Biology 22 2 428 - 36 2008年02月 [査読有り][通常論文]
     
    Recent evidence suggests that bone marrow-derived cells may contribute to repair and lesion formation following vascular injury. In most studies, bone marrow-derived cells were tracked by transplanting exogenous cells into bone marrow that had been compromised by irradiation. It remains to be determined whether endogenous circulating progenitors actually contribute to arterial remodeling under physiological conditions. Here, we established a parabiotic model in which two mice were conjoined subcutaneously without any vascular anastomosis. When wild-type mice were joined with transgenic mice that expressed green fluorescent protein (GFP) in all tissues, GFP-positive cells were detected not only in the peripheral blood but also in the bone marrow of the wild-type mice. The femoral arteries of the wild-type mice were mechanically injured by insertion of a large wire. At 4 wk, there was neointima hyperplasia that mainly consisted of alpha-smooth muscle actin-positive cells. GFP-positive cells were readily detected in the neointima (14.8+/-4.5%) and media (31.1+/-8.8%) of the injured artery. Some GFP-positive cells expressed alpha-smooth muscle actin or an endothelial cell marker. These results indicate that circulating progenitors contribute to re-endothelialization and neointimal formation after mechanical vascular injury even in nonirradiated mice.
  • 糖尿病網膜症を伴う虚血性心疾患 薬剤溶出ステントと冠状動脈バイパスとの比較
    益澤 明広, 大野 貴之, 木下 修, 小野 稔, 本村 昇, 高本 眞一, 藤田 英雄, 安東 治郎, 森田 敏宏, 永井 良三
    日本心臓血管外科学会雑誌 37 Suppl. 361 - 361 (NPO)日本心臓血管外科学会 2008年01月
  • Makoto Sonoda, Katsu Takenaka, Kansei Uno, Aya Ebihara, Ryozo Nagai
    Journal of Echocardiography 6 1 1 - 8 2008年 [査読有り][通常論文]
     
    Background: Severe mitral regurgitation (MR) is one of the most important complications of mitral. valve prolapse (MVP) and it often requires surgical treatment. This study is aimed to assess the relation of mitral valve morphology to severe MR complicated with, MVP. Methods: Transesophageal echocardiography was performed in 37 patients with MVP and 30 control subjects. Results: The anterior mitral leaflet (AML) and posterior mitral leaflet (PML) were thicker and longer, and the mitral annulus was larger in patients with MVP than in control subjects (p< 0.05). The degree of MVP correlated significantly with the leaflet thickness in systole (AML r=0.70, PML: r=0.65, p< 0.05). In patients with MVP without ruptured chordae tendineae (RCT), the severity of MR correlated significantly with the leaflet thickness, leaflet length and annular diameter (p< 0.05). The prolapsed PMLs with RCT were thicker and longer than those without RCT (p< 0.05). Conclusions: The leaflet thickness, leaflet length and annular diameter are "proportionally" redundant in patients with MVP, and the redundancy is closely related to the occurrence of RCT or severe MR. © 2008 Japanese Society of Echocardiography.
  • Makoto Sonoda, Teruhiko Aoyagi, Katsu Takenaka, Kansei Uno, Ryozo Nagai
    International Heart Journal 49 1 95 - 103 2008年01月 [査読有り][通常論文]
     
    Angiotensin receptor blockers (ARB) have been emerging as drugs to treat atherosclerosis. The effectiveness of the ARB losartan at reducing atherosclerosis was compared with that of ACE inhibitors in hypertensive patients. A total of 50 patients with hypertension were divided into 3 groups: a control group receiving neither an ARB nor an ACE inhibitor (n = 14), a losartan group (n = 22) receiving 50 mg/day of losartan, and an ACE, inhibitor group (n = 14) receiving either 5 mg/day of enalapril or 5 mg/ day of imidapril. Atherosclerosis was evaluated based on the intima-media thickness (IMt) of the common carotid artery measured by B-mode ultrasound at baseline and after approximately 12 months of treatment. After the treatment IMT significantly decreased with losartan (from 0.87 ± 0.14 to 0.79 ± 0.16 mm, P < 0.05) and with ACE inhibitor (from 0.81 ± 0.14 to 0.74 ± 0.11 mm, P < 0.05). The reduction was comparable between the two groups, -0.078 ± 0.136 with losartan and -0.073 ± 0.109 mm with ACE inhibitor, and the rate of the reduction was similar between the two drugs -0.098 ± 0.142 mm/year with losartan and (-0.076 ± 0.118 mm/year) with ACE inhibitor. On the contrary, IMT did not change in the control group (from 0.90 ± 0.20 to 0.95 ± 0.26 mm) during the treatment period. Concomitant medication and coronary risk factors such as hyperlipidemia, diabetes mellitus, and smoking did not differ significantly among the groups. The antiatherosclerotic- effect of losartan on the carotid artery was comparable to that of ACE-inhibitors, and less adverse effects, such as coughing that occurs with ACE inhibitors, were observed. Losartan appears to be a better alternative to ACE inhibitors for treating atherosclerosis in Japanese hypertensive patients.
  • Yo Tanaka, Kae Sato, Tatsuya Shimizu, Masayuki Yamato, Teruo Okano, Ichiro Manabe, Ryozo Nagai, Takehiko Kitamori
    Lab on a chip 8 1 58 - 61 2008年01月 [査読有り][通常論文]
     
    We have demonstrated the working principle of a bio-microactuator using smooth muscle cells (SMCs) by driving micropillars coupled to cultured SMCs and controlled pillar displacements by chemical stimuli; the generated driving force was estimated to be over 1.1 microN.
  • Nobukazu Ishizaka, Yuko Ishizaka, Ei-Ichi Toda, Kazuhiko Koike, Minoru Yamakado, Ryozo Nagai
    ARTERIOSCLEROSIS THROMBOSIS AND VASCULAR BIOLOGY 28 1 160 - 165 2008年01月 [査読有り][通常論文]
     
    Objective-Carcinoembryonic antigen (CEA), a serological marker of malignant tumors, may show a modest increase under some nonmalignant conditions, such as ageing and cigarette smoking. We have investigated whether serum CEA levels are associated with early carotid atherosclerosis. Methods and Results-Cross-sectional data from 4181 male individuals who underwent general health screening were analyzed. The interquartile of cutoff values of serum CEA levels were 1.0, 1.6, and 2.5 ng/mL. Cigarette smoking was associated with increased serum CEA levels in a dose- and duration-dependent manner, and this association was more prominent in current than former smokers. Logistic regression analysis adjusted for age, body mass index, serum lipid and glucose profiles, white blood cell count, C-reactive protein, and smoking habits showed that the first, second, third, and fourth CEA quartiles were associated with carotid plaque with an odds ratio of 1 (reference), 1.25 (95% CI 1.03 to 1.52, P=0.023), 1.49 (95% CI 1.23 to 1.82 P<0.001), and 1.34 (95% CI 1.08 to 1.65, P=0.007), respectively. Although serum CEA levels were associated with metabolic syndrome, association between serum CEA and carotid plaque was significant in individuals without metabolic syndrome. Conclusions-Serum CEA was associated with carotid atherosclerosis independently of atherogenic risk factors and markers of inflammation. Our data suggest that a slight elevation of CEA in current smokers, as well as in never smokers, may not be an innocuous observation from the viewpoint of atherosclerosis.
  • Yuka Ichikawa-Shindo, Takayuki Sakurai, Akiko Kamiyoshi, Hisaka Kawate, Nobuyoshi Iinuma, Takahiro Yoshizawa, Teruhide Koyama, Junichi Fukuchi, Satoshi Iimuro, Nobuo Moriyama, Hayato Kawakami, Toshinori Murata, Kenji Kangawa, Ryozo Nagai, Takayuki Shindo
    The Journal of clinical investigation 118 1 29 - 39 2008年01月 [査読有り][通常論文]
     
    Adrenomedullin (AM) is a peptide involved both in the pathogenesis of cardiovascular diseases and in circulatory homeostasis. The high-affinity AM receptor is composed of receptor activity-modifying protein 2 or 3 (RAMP2 or -3) and the GPCR calcitonin receptor-like receptor. Testing our hypothesis that RAMP2 is a key determinant of the effects of AM on the vasculature, we generated and analyzed mice lacking RAMP2. Similar to AM-/- embryos, RAMP2-/- embryos died in utero at midgestation due to vascular fragility that led to severe edema and hemorrhage. Vascular ECs in RAMP2-/- embryos were severely deformed and detached from the basement membrane. In addition, the abnormally thin arterial walls of these mice had a severe disruption of their typically multilayer structure. Expression of tight junction, adherence junction, and basement membrane molecules by ECs was diminished in RAMP2-/- embryos, leading to paracellular leakage and likely contributing to the severe edema observed. In adult RAMP2+/- mice, reduced RAMP2 expression led to vascular hyperpermeability and impaired neovascularization. Conversely, ECs overexpressing RAMP2 had enhanced capillary formation, firmer tight junctions, and reduced vascular permeability. Our findings in human cells and in mice demonstrate that RAMP2 is a key determinant of the effects of AM on the vasculature and is essential for angiogenesis and vascular integrity.
  • Daiju Fukuda, Masataka Sata, Nobukazu Ishizaka, Ryozo Nagai
    ARTERIOSCLEROSIS THROMBOSIS AND VASCULAR BIOLOGY 28 1 90 - 96 2008年01月 [査読有り][通常論文]
     
    Objective-It is suggested that the angiotensin II (Ang II)-Ang II type 1 receptor (AT1R) pathway plays a pivotal role in the pathogenesis of atherosclerosis. Recently, bone marrow (BM) cells were reported to express AT1R. Here, we investigated the role of AT1R in BM in the pathogenesis of atherosclerosis. Methods and Results-Genetic ablation or pharmacological blockade of AT1R led to a significant reduction and stabilization of atherosclerotic lesions in ApoE(-/-) mice. To elucidate the role of AT1R in BM, we generated several BM chimeric mice. Ang II promoted atherosclerosis progression in the BM chimeric mice that had AT1aR in BM, regardless of the absence of AT1aR in the recipient vasculature (P<0.05). BM chimeric mice whose BM AT1aR was disrupted showed significantly less atherosclerotic lesions in aorta (P<0.05) and more stable plaque with reduced accumulation of BM-derived cells compared with BM chimeric mice that had AT1aR-positive BM. Most of the BM-derived cells in atheroma were positive for a macrophage marker and expressed matrix metalloproteinase (MMP)-9 and monocyte chemoattractant protein-1. Conclusions-Our findings suggest that AT1R in BM plays an important role in the pathogenesis of atherosclerosis.
  • Po-Hsun Huang, Masataka Sata, Hiroaki Nishimatsu, Makoto Sumi, Yasunobu Hirata, Ryozo Nagai
    Biomedicine & pharmacotherapy = Biomedecine & pharmacotherapie 62 1 46 - 52 2008年01月 [査読有り][通常論文]
     
    Angiogenesis, the formation of new blood vessels, is a physiological response to tissue ischemia. Clinical evidence suggests that diabetic patients have endothelial dysfunction and impaired angiogenesis in response to ischemia. Here, we investigated the impact of diabetes on ischemia-induced collateral growth, and tested the hypothesis that peroxisome proliferator-activated receptor-gamma (PPARgamma) agonist augments collateral flow to ischemic tissue. We conducted unilateral hindlimb ischemia surgery in KKAy mice. Blood flow recovery was markedly impaired in diabetic mice compared with that in wild-type mice as determined by laser Doppler imaging. Treatment of KKAy mice with pioglitazone partially restored the blood flow recovery. Anti-CD31 immunostaining revealed that pioglitazone also significantly improved the capillary density in ischemic limb muscle. Endothelial NO synthase (eNOS) activity was ameliorated in diabetic mice treated with pioglitazone as determined by vasorelaxation in response to acetylcholine. Pioglitazone normalized vascular endothelial growth factor (VEGF) protein levels, which was decreased in ischemic muscle of KKAy mice, and up-regulated eNOS phosphorylation at Ser-1177 and Akt phosphorylation at Ser-473 in ischemic muscle. Pioglitazone had no beneficial effects on blood flow recovery in diabetic mice treated with N(G)-nitro-l-arginine methyl ester (L-NAME). Our findings demonstrate that pioglitazone significantly ameliorates endothelial dysfunction and enhances blood flow recovery after tissue ischemia in diabetic mice. Activation of eNOS appears to be essential for pioglitazone to promote angiogenesis in ischemic tissue.
  • Kan Saito, Takafumi Ito, Nobuko Asashima, Minoru Ohno, Ryozo Nagai, Hiromi Fujita, Nobuo Koizumi, Ai Takano, Haruo Watanabe, Hiroki Kawabata
    American Journal of Tropical Medicine and Hygiene 77 6 1124 - 1127 2007年12月 [査読有り][通常論文]
     
    A 78-year-old Japanese man who had clinical symptoms and a flu-like illness with fever, chills, diarrhea, and arthralgia had traveled to Cambodia and Khabarovsk, Russia, before the onset of symptoms and illness. He had been bitten by an Ixodes persulcatus tick in which the DNA of Borrelia valaisiana was detected. The patient's symptoms improved rapidly after treatment with minocycline. Serologic examination detected antibodies to Lyme disease Borrelia. An flabB polymerase chain reaction with the patient's plasma amplified a DNA fragment similar to that of B. valaisiana. Copyright © 2007 by The American Society of Tropical Medicine and Hygiene.
  • M Horikoshi, K Hara, C Ito, N Shojima, R Nagai, K Ueki, P Froguel, T Kadowaki
    Diabetologia 50 12 2461 - 6 2007年12月 [査読有り][通常論文]
     
    AIMS/HYPOTHESIS: Recently, several groups have carried out whole-genome association studies in European and European-origin populations and found novel type 2 diabetes-susceptibility genes, fat mass and obesity associated (FTO), solute carrier family 30 (zinc transporter), member 8 (SLC30A8), haematopoietically expressed homeobox (HHEX), exostoses (multiple) 2 (EXT2), CDK5 regulatory subunit associated protein 1-like 1 (CDKAL1), cyclin-dependent kinase inhibitor 2B (p15, inhibits CDK4) (CDKN2B) and insulin-like growth factor 2 mRNA binding protein 2 (IGF2BP2), which had not been in the list of functional candidates. The aim of this study was to determine the association between single nucleotide polymorphisms (SNPs) in these genes and type 2 diabetes in participants from the Japanese population. METHODS: Sixteen previously reported SNPs were genotyped in 864 Japanese type 2 diabetes individuals (535 men and 329 women; age 63.1 +/- 9.5 years (mean+/-SD), BMI 24.3 +/- 3.9 kg/m(2)) and 864 Japanese control individuals (386 men and 478 women; age 69.5 +/- 6.8 years, BMI 23.8 +/- 3.7 kg/m(2)). RESULTS: The SNPs rs5015480 [odds ratio (OR) = 1.46 (95% CI 1.20-1.77), p = 2.0 x 10(-4)], rs7923837 [OR = 1.40 (95% CI 1.17-1.68), p = 2.0 x 10(-4)] and rs1111875 [OR = 1.30 (95% CI 1.11-1.52), p = 0.0013] in HHEX were significantly associated with type 2 diabetes with the same direction as previously reported. SNP rs8050136 in FTO was nominally associated with type 2 diabetes [OR = 1.22 (95% CI 1.03-1.46), p = 0.025]. SNPs in other genes such as rs7756992 in CDKAL1, rs10811661 in CDKN2B and rs13266634 in SLC30A8 showed nominal association with type 2 diabetes. rs7756992 in CDKAL1 and rs10811661 in CDKN2B were correlated with impaired pancreatic beta cell function as estimated by the homeostasis model assessment beta index (p = 0.023, p = 0.0083, respectively). CONCLUSIONS/INTERPRETATION: HHEX is a common type 2 diabetes-susceptibility gene across different ethnic groups.
  • Yoshinori Takeuchi, Naoya Yahagi, Yoshimi Nakagawa, Takashi Matsuzaka, Ritsuko Shimizu, Motohiro Sekiya, Yoko Iizuka, Ken Ohashi, Takanari Gotoda, Masayuki Yamamoto, Ryozo Nagai, Takashi Kadowaki, Nobuhiro Yamada, Jun-Ichi Osuga, Hitoshi Shimano
    Biochemical and biophysical research communications 363 2 329 - 35 2007年11月 [査読有り][通常論文]
     
    Sterol regulatory element-binding protein (SREBP)-1c is the master regulator of lipogenic gene expression in liver. The mRNA abundance of SREBP-1c is markedly induced when animals are refed after starvation, although the regulatory mechanism is so far unknown. To investigate the mechanism of refeeding response of SREBP-1c gene expression in vivo, we generated a transgenic mouse model that carries 2.2kb promoter region fused to the luciferase reporter gene. These transgenic mice exhibited refeeding responses of the reporter in liver and adipose tissues with extents essentially identical to those of endogenous SREBP-1c mRNA. The same results were obtained from experiments using adenovirus-mediated SREBP-1c-promoter-luciferase fusion gene transduction to liver. These data demonstrate that the regulation of SREBP-1c gene expression is at the transcription level, and that the 2.2kb 5'-flanking region is sufficient for this regulation. Moreover, when these transgenic or adenovirus-infected mice were placed on insulin-depleted state by streptozotocin treatment, the reporter expression was upregulated as strongly as in control mice, demonstrating that this regulation is not dominated by serum insulin level. These mice are the first models to provide the mechanistic insight into the transcriptional regulation of SREBP-1c gene in vivo.
  • Taeko Tsuji, Jun-Ichi Suzuki, Ryoichi Shimamoto, Tadashi Yamazaki, Yuki Ohomoto, Kuniaki Iwasawa, Ryozo Nagai
    International Heart Journal 48 5 615 - 621 2007年11月 [査読有り][通常論文]
     
    The need for long-term follow-up in Kawasaki disease is poorly recognized although cardiac sudden death attacks asymptomatic young people with past illness after a long latent period. Therefore, in order to prevent cardiac disasters, high risk groups should be identified and the prevalence rate of the disease should be determined for crisis management. A total of 9,965 consecutive freshmen at the University of Tokyo were the subject of a questionnaire. Their parents/guardians who were briefed on the diagnostic criteria of the acute phase of Kawasaki disease actually completed the questionnaire. Students with a positive diagnosis underwent rest and exercise-stress electrocardiography and routine echocardiography. The overall prevalence rate was 0.57%. The rate in males (0.63%) was greater than that in females (0.32%) (P < 0.05). Electrocardiography and routine echocardiography identified no indices specific to a past illness of Kawasaki disease. The prevalence rate indicated that about 6 in 1000 students were high risk students who needed special care while at university. Since there are few symptoms and no signs indicating a past illness of Kawasaki disease, intensive history-taking from parents/guardians who are familiar with their acute symptoms during childhood is required in order to identify those at high risk of a coronary event.
  • Norihiko Takeda, Koji Maemura, Shuichi Horie, Katsutaka Oishi, Yasushi Imai, Tomohiro Harada, Tetsuya Saito, Taro Shiga, Eisuke Amiya, Ichiro Manabe, Norio Ishida, Ryozo Nagai
    The Journal of biological chemistry 282 45 32561 - 7 2007年11月 [査読有り][通常論文]
     
    Cardiovascular diseases are closely related to circadian rhythm, which is under the control of an internal biological clock mechanism. Although a biological clock exists not only in the hypothalamus but also in each peripheral tissue, the biological relevance of the peripheral clock remains to be elucidated. In this study we searched for clock-controlled genes in vascular endothelial cells using microarray technology. The expression of a total of 229 genes was up-regulated by CLOCK/BMAL2. Among the genes that we identified, we examined the thrombomodulin (TM) gene further, because TM is an integral membrane glycoprotein that is expressed primarily in vascular endothelial cells and plays a major role in the regulation of intravascular coagulation. TM mRNA and protein expression showed a clear circadian oscillation in the mouse lung and heart. Reporter analyses, gel shift assays, and chromatin immunoprecipitation analyses using the TM promoter revealed that a heterodimer of CLOCK and BMAL2 binds directly to the E-box of the TM promoter, resulting in TM promoter transactivation. Indeed, the oscillation of TM gene expression was abolished in clock mutant mice, suggesting that TM expression is regulated by the clock gene in vivo. Finally, the phase of circadian oscillation of TM mRNA expression was altered by temporal feeding restriction, suggesting TM gene expression is regulated by the peripheral clock system. In conclusion, these data suggest that the peripheral clock in vascular endothelial cells regulates TM gene expression and that the oscillation of TM expression may contribute to the circadian variation of cardiovascular events.
  • Nobukazu Ishizaka, Yuko Ishizaka, Ei-ichi Toda, Kazuhiko Koike, George Seki, Ryozo Nagai, Minoru Yamakado
    HYPERTENSION RESEARCH 30 11 1059 - 1064 2007年11月 [査読有り][通常論文]
     
    Obesity is a known risk factor for hypertension and diabetes, both of which ultimately promote renal dysfunction. In the current study, we investigated the association between body mass index (BMI) and chronic kidney disease (CKD) in 8,168 Japanese individuals (2,924 women, 5,244 men) who underwent general health screening. CKD was diagnosed if the estimated glomerular filtration rate (eGFR) was less than 60 mL/ min/1.73 m(2) (designated as low eGFR) and/or if the urinary albumin/creatinine value was equal to or greater than 30 mg/g (designated as albuminuria). Logistic regression analysis adjusted for age, systolic blood pressure, fasting glucose, and smoking habits showed that, in men, both overweight (BMI 25-29 kg/m(2)) and obesity (BMI >= 30 kg/m(2)) were associated with increased prevalence of low eGFR and albuminuria, whereas, in women, obesity was associated with albuminuria, but neither overweight nor obesity was associated with low eGFR. After multivariate adjustment, logistic regression analysis showed that BMI had a graded association with both low eGFR and albuminuria in men. On the other hand, in women, the second and third BMI quartiles were associated with a lower prevalence of albuminuria in comparison with the first BMI quartile. Essentially the same results were obtained when the subjects were subdivided according to the presence and absence of hypertension. Our data showed that overweight and obesity were associated with increased risk for CKD in Japanese individuals undergoing a general health screening, irrespective of the presence or absence of hypertension, although there was a gender difference in these associations.
  • Takayuki Ohno, Shinichi Takamoto, Noboru Motomura, Minoru Ono, Jiro Ando, Toshihiro Morita, Hideo Fujita, Yasunobu Hirata, Ryozo Nagai, Takashi Shigeeda, Akira Hirose
    The Annals of thoracic surgery 84 5 1474 - 8 2007年11月 [査読有り][通常論文]
     
    BACKGROUND: We compared the 1-year outcome of coronary revascularization with sirolimus-eluting stents (SESs) or coronary artery bypass grafting (CABG) for coronary artery disease involving the left anterior descending artery (LAD) in diabetic patients according to their retinal status: no diabetic retinopathy (NDR) and diabetic retinopathy (DR). METHODS: Between April 2004 and October 2005, 220 consecutive patients with coronary artery disease involving the LAD underwent implantation of SESs; of these, 25 patients had NDR and 54 had DR. For each group, we included a comparison group of diabetic patients who had undergone CABG and had the same retinal status. RESULTS: During 1 year after revascularization, five cardiac events (cardiac death, myocardial infarction, and repeat revascularization) were noted in NDR-SES patients, four in NDR-CABG, 24 in DR-SES, and eight in DR-CABG patients. Most cardiac events were repeat revascularizations. Kaplan-Meier estimates of the incidence of cardiac events at 1 year were 21.1%, 11.4%, 44.0%, and 14.0%, respectively. Kaplan-Meier curves for cardiac events in SES patients were different from those of CABG patients for the DR group (p = 0.003), but not NDR groups. After adjustments for the potential confounders, the hazard ratio of cardiac events in DR-SES patients was 2.8 (95% confidence interval, 1.1 to 6.9; p = 0.02). CONCLUSIONS: Compared with SES implantation, CABG is more suitable for revascularization in patients with coronary artery disease involving the LAD and DR.
  • Tadashi Yamazaki, Jun-ichi Suzuki, Ryoichi Shimamoto, Taeko Tsuji, Yuki Ohmoto-Sekine, Kuni Ohtomo, Ryozo Nagai
    INTERNATIONAL HEART JOURNAL 48 6 715 - 724 2007年11月 [査読有り][通常論文]
     
    A randomized and prospective study was designed to prove the efficacy-of angiotensin II receptor blockers (ARB) in the amelioration of myocardial impairment in hypertrophic nonobstructive cardiomyopathy (HNCM). Nineteen consecutive patients with HNCM were randomly assigned to two groups and then underwent cine magnetic resonance evaluation of left ventricular mass (LVM) twice just before and after one year of observation. In the ARB group, 50 mg of losartan potassium was administered once daily during the observation period. The ratio of LVM after the observation period over that before the period was blindly compared between the two groups to estimate morphologically the ameliorative effect of ARB. In the ARB group, LVM was 203 47 cm(3) before the treatment period and 190 +/- 55 cm(3) after the period and the ratio of the final LVM over the initial LVM was 0.93 +/- 0.10. In the non-ARB group the initial and final LVM values were 177 48 cm(3) and 179 45 cm(3), and the ratio of the final LVM over the initial LVM was 1.02 +/- 0.07. The ratio of the final LVM over the initial LVM in the ARB group was significantly smaller (P = 0.03) than that in the non-ARB group. The smaller ratio in the ARB group strongly indicates that ARB ameliorated the natural course of HNCM during the one year observation period. Thus, this is the first demonstration of the therapeutic efficacy of ARB in human HNCM.
  • Nobukazu Ishizaka, Yuko Ishizaka, Ei-ichi Toda, Kazuhiko Koike, George Seki, Ryozo Nagai, Minoru Yamakado
    HYPERTENSION RESEARCH 30 11 1035 - 1041 2007年11月 [査読有り][通常論文]
     
    We investigated whether chronic kidney disease (CKD) was associated with carotid intima-media thickening in 1,351 male individuals undergoing general health screening. Glomerular filtration rate (GFR) was estimated by the Modification of Diet in Renal Disease equations using 0.881 as a coefficient for Japanese, and low estimated GFR (eGFR) was defined as an eGFR value of < 60 mL/min/1.73 m(2). Albuminuria was defined as a urine albumin-to-urine creatinine ratio of >= 30 mg/g, and CKD was defined when low eGFR and/or albuminuria was present. After adjusting for age, CKD was associated with carotid intima-media thickening with an odds ratio of 1.47 (95% confidence interval [CI] 1.05-2.06, p=0.0024). After adjusting for age, fasting plasma glucose, and smoking status, both albuminuria and low eGFR were significantly associated with intima-media thickening in individuals with hypertension with an odds ratio of 1.85 (95% CI 1.13-3.03, p=0.015) and 1.79 (95% CI 1.09-2.94, p=0.022), respectively. On the other hand, neither of them was associated with carotid intima-media thickening in individuals without hypertension. Similarly, after adjusting for age, systolic blood pressure, and smoking status, both albuminuria and low eGFR were significantly associated with intima-media thickening in individuals with high fasting glucose (defined as fasting plasma glucose levels of >= 110 mg/dL or current use of anti-diabetic medication), but not in those without. Our data indicate that CKD or its components (low eGFR and albuminuria) may be associated with early carotid atherosclerosis in low-risk individuals, such as those undergoing general health screening, who have hypertension and/or impaired glucose metabolism.
  • Takaaki Yamada, Takahisa Kondo, Yasushi Numaguchi, Michitaka Tsuzuki, Tatsuaki Matsubara, Ichiro Manabe, Masataka Sata, Ryozo Nagai, Toyoaki Murohara
    Arteriosclerosis, thrombosis, and vascular biology 27 11 2363 - 9 2007年11月 [査読有り][通常論文]
     
    OBJECTIVES: Angiotensin II (ATII) type 1 receptor (AT1R) blocker (ARB) has been shown to inhibit neointimal formation. Bone marrow-derived mononuclear cells (BM-MNCs) give rise to smooth muscle (SM)-like cells at injured arterial wall and contribute to neointimal formation. However, role of the renin-angiotensin system in the homing process of SM-like cells during neointimal formation is unknown. MATERIAL AND METHODS: When human BM-MNCs and peripheral blood MNCs (PB-MNCs) were cultured under treatment with PDGF-BB and bFGF, these cells gave rise to SM-like cells with expression of alphaSMA, SMemb, and SM1 proteins. RT-PCR showed the expression of AT1R, ATII type 2 receptor (AT2R), alphaSMA, and SMemb mRNAs. ATII accelerated the differentiation of SM-like cells, which was inhibited by an ARB CV11974 (P<0.05). We then examined the effects of ATII, CV11974, and AT2R antagonist PD123319 on neointimal formation and BM-derived SM-like cell incorporation at injured arteries in vivo. BM from green fluorescence protein (GFP)-transgenic mice was transplanted to irradiated WT mice. GFP-BM chimera mice were subjected to wire injury on the left femoral artery. ATII (100 ng/kg/min) stimulated whereas CV11974 (1 mg/kg/d) inhibited neointimal formation. Number of GFP+ alphaSMA+ cells at neointima correlated with the intima/media ratio (r=0.69, P<0.05). CONCLUSION: BM-derived SM-like progenitor cells contributed to the neointimal formation after arterial injury. ATII accelerated whereas ARB suppressed this process. These are new aspects of the ARB-mediated inhibition of atherosclerotic disease progression.
  • Takaoka Minoru, Sata Masataka, Nagai Ryozo
    CIRCULATION 116 16 208  2007年10月 [査読有り][通常論文]
  • Enomoto Soichire, Sata Masataka, Sumi Makoto, Asakura Tetsuo, Nagai Ryozo
    CIRCULATION 116 16 157  2007年10月 [査読有り][通常論文]
  • Iwata Hiroshi, Manabe Ichire, Fujiu Katsuhito, Yamamoto Tetsufumi, Takeda Norifurni, Kuro-O Makoto, Sata Masataka, Nagai Ryozo
    CIRCULATION 116 16 71  2007年10月 [査読有り][通常論文]
  • Sahara Makoto, Sata Masataka, Morita Toshihiro, Hirata Yasunobu, Nagai Ryozo
    CIRCULATION 116 16 122  2007年10月 [査読有り][通常論文]
  • Sahara Makoto, Sata Masataka, Morita Toshihiro, Hirata Yasunobu, Nagai Ryozo
    CIRCULATION 116 16 242  2007年10月 [査読有り][通常論文]
  • Shiga Taro, Maemura Koji, Imai Yasushi, Kawanami Daiji, Takeda Norihiko, Ando Jiro, Morita Toshihiro, Manabe Ichiro, Hayashi Dobun, Sugiyama Akira, Miyamoto Kyoko, Sagara Mina, Ito Yukio, Yamazaki Tsutomu, Hirata Yasunobu, Kodama Tatsuhiko, Nagai Ryozo
    CIRCULATION 116 16 363  2007年10月 [査読有り][通常論文]
  • Wang Guoqin, Watanabe Masafumi, Imaj Yasushi, Hara Kazuo, Manabe Ichiro, Maemura Koji, Matsumoto Sahohime, Horikoshi Momoko, Kadowaki Takashi, Yamazaki Tsutomu, Nagai Ryozo
    CIRCULATION 116 16 507 - 507 2007年10月 [査読有り][通常論文]
  • Nobukazu Ishizaka, Yuko Ishizaka, Ei-Ichi Toda, Ryozo Nagai, Kazuhiko Koike, Hideki Hashimoto, Minoru Yamakado
    Diabetes Research and Clinical Practice 78 1 72 - 76 2007年10月 [査読有り][通常論文]
     
    We found that cigarette smoking increased white blood cell count, and individuals which increased white blood cell count more likely to have metabolic syndrome in Japanese men. We investigated whether similar relationship can be observed also in women. We analyzed the data from 16,383 Japanese women who underwent general health screening. Age-adjusted logistic regression analysis showed that current smoking was positively associated with a highest white blood cell count quartile with an odds ratio of 2.40 (95% CI: 2.16-2.68, P < 0.0001). The white blood cell count showed a graded association with metabolic syndrome. On the other hand, the association between current smoking and metabolic syndrome was no longer significant after subdividing the individuals into groups according to the white blood cell quartile. These data collectively suggested that the association between current smoking and metabolic syndrome is heavily confounded by certain factors that increase the circulating white blood cell count in Japanese women, as in men. © 2007 Elsevier Ireland Ltd. All rights reserved.
  • Yuki Ohmoto-Sekine, Jun-ichi Suzuki, Ryoichi Shimamoto, Tadashi Yamazaki, Taeko Tsuji, Ryozo Nagai, Kuni Ohtomo
    Gender Medicine 4 3 274 - 283 2007年09月 [査読有り][通常論文]
     
    Background: Despite male predominance in the prevalence of hypertrophic cardiomyopathy (HCM), repeated diagnosis at our institute indicates a possible higher prevalence of deep Q waves with HCM in women. Objective: The current study examined gender similarities and differences in the prevalence of deep Q waves in HCM and in the morphologic and electrocardiographic features of HCM with deep Q waves. Methods: Patients with HCM underwent cardiac magnetic resonance (CMR) imaging to identify the prevalence of deep Q waves in electrocardiographic limb leads, and to analyze the relationship between distribution patterns of deep Q waves and those of the localization of maximum amplitude of left ventricular (LV) hypertrophy. Contiguous LV short-axis images were obtained from the base toward the apex. Results: Of the 200 consecutive patients (172 males, aged 20-78 years 28 females, aged 16-79 years) with HCM who underwent CMR imaging, 10 male and 8 female patients had deep Q waves. Deep Q waves were more prevalent in females with HCM than in their male counterparts (28.6% vs 5.8%, respectively P < 0.001). Of the 18 patients with deep Q waves, maximum wall thickness was localized at either the basal anterior wall or the midventricular septum in 9 (90%) of the 10 male patients and 6 (75%) of the 8 female patients. In both sexes, the Q wave distribution pattern of I and aVL and of II and aVF indicated localization of maximum hypertrophy at the midventricular septum in 6 (75%) of the 8 patients with the former pattern, and at the basal anterior wall in 9 (90%) of the 10 patients with the latter pattern. Conclusions: Diagnostic deep Q waves were detected more frequently in female patients with HCM than in their male counterparts. In HCM with deep Q waves in limb leads, morphologic and electrocardiographic analysis showed similar features in both sexes. (Gend Med. Keywords: deep Q wave, hypertrophic cardiomyopathy, gender, cardiac magnetic resonance. © 2007 Excerpta Medica, Inc.
  • 平滑筋ミオシン、平滑筋アクチンレポーターマウスを用いた血管リモデリングにおける平滑筋細胞起源の検討
    岩田 洋, 佐田 政隆, 真鍋 一郎, 藤生 克人, 武田 憲文, 永井 良三
    脈管学 47 Suppl. S112 - S112 (一社)日本脈管学会 2007年09月 [査読有り][通常論文]
  • Nobukazu Ishizaka, Yuko Ishizaka, Ei-Ichi Toda, Ryozo Nagai, Minoru Yamakado
    Internal Medicine 46 15 1167 - 1172 2007年08月 [査読有り][通常論文]
     
    Objective: Cigarette smoking increases the circulating white blood cell (WBC) count and the prevalence of metabolic syndrome. We investigated the association between cigarette smoking, WBC count, and metabolic syndrome as defined by the Japanese criteria. Method: Cross-sectional data from 3,687 men undergoing general health screening between 2005 and 2006 were analyzed. Results: After adjustment for age and total cholesterol, former and current smoking were associated with the highest WBC quartile (≥6.3 × 103 cells/μL) with an odds ratio of 1.35 (95% CI 1.09-1.66, P=0.0055) and 4.45 (95% CI 3.69-5.37, P< 0.0001), respectively. It was found that increased WBC count was a risk factor for metabolic syndrome on the other hand, the current smoking was not found to be a predictor for metabolic syndrome, when each WBC count quartile was separately analyzed. Conclusions: Our data suggest that the risk for MetS, defined by Japanese criteria, might be estimated by the WBC count in Japanese men irrespective of their smoking status, although it should also be noted that the cigarette smoking increases the number of circulating WBC count. © 2007 The Japanese Society of Internal Medicine.
  • Nobukazu Ishizaka, Yuko Ishizaka, Ryozo Nagai, Ei-Ichi Toda, Hideki Hashimoto, Minoru Yamakado
    ATHEROSCLEROSIS 193 2 373 - 379 2007年08月 [査読有り][通常論文]
     
    Serum albumin is a maker of nutritional status and possesses antioxidative properties. Here, we have sought to investigate the mode of association between serum albumin levels, metabolic syndrome, and carotid atherosclerosis by analyzing the data of the cross-sectional data from 8143 individuals who underwent general health screening test. After adjusting for age, total cholesterol, and smoking status, the highest quartile of serum albumin (>= 4.7 g/dL) was associated with increased prevalence of metabolic syndrome with an odds ratio of 1.80 (95% CI 1.41-2.23, P < 0.0001) in women, and 1.60 (95% CI 1.44-1.78, P < 0.0001) in men, when compared to the lowest serum albumin quartile (< 4.3 g/dL). By contrast, when compared with the lowest quartile, the highest quartile of serum albumin was associated with reduced prevalence of carotid plaque with an odds ratio of 0.62 (95% CI 0.42-0.9 1, P < 0.001) in women, and 0.76 (95% CI 0.62-0.93, P < 0.0 1) in men, and for carotid intima-media thickening with an odds ratio of 0.57 (95% CI 0.35-0.94, P < 0.05) in women, and 0.71 (95% CI 0.55-0.92, P < 0.0 1) in men. Our data showed that higher serum albumin was inversely associated with the prevalence of early carotid atherosclerosis, although it was positively associated with the prevalence of metabolic syndrome. Whether these observations are in part explained by the antioxidative properties of albumin requires further investigation. (c) 2006 Elsevier Ireland Ltd. All rights reserved.
  • Yoshinori Seko, Hideo Yagita, Ko Okumura, Miyuki Azuma, Ryozo Nagai
    Cardiovascular Research 75 1 158 - 167 2007年07月 [査読有り][通常論文]
     
    Objective: This study was designed to investigate the roles of programmed death-1 (PD-1) and PD-1ligands (PD-L) in the development of murine acute myocarditis caused by Coxsackievirus B3. PD-1/PD-L belong to the CD28/B7 superfamily, and the PD-1/PD-L pathway is known to transduce a negative immunoregulatory signal that antagonizes the T-cell receptor-CD28 signal and inhibits T-cell activation. Methods: We first analyzed the expression of PD-L1/PD-L2 on cardiac myocytes in vivo and in vitro. Second, we examined the effects of in vivo treatment with an anti-PD-1, PD-L1, or PD-L2 monoclonal antibodies on the development of myocardial inflammation in C3H/He mice infected with Coxsackievirus B3. Third, to investigate the effects of anti-PD-1 monoclonal antibody treatment on the activation of the infiltrating cells, we examined the expression of interleukin (IL)-2, interferon (IFN)-γ, CD40 ligand (CD40L), Fas ligand (FasL), and perforin as activation markers in mouse hearts by a semiquantitative PCR method. Results: PD-L1 was markedly induced on cardiac myocytes with acute myocarditis. In vivo anti-PD-1 or -PD-L1 blocking monoclonal antibody treatment increased the myocardial inflammation whereas anti-PD-1 stimulating monoclonal antibody treatment decreased the myocardial inflammation, and anti-PD-L2 monoclonal antibody treatment had no effect. Anti-PD-1 monoclonal antibody treatment significantly increased the expression of IFN-γ, FasL, CD40L, perforin, and Coxsackievirus B3 genomes in myocardial tissue. Conclusion: Our findings strongly suggest that the PD-1/PD-L1 pathway played a pivotal role in suppressing myocardial inflammation and raise the possibility of immunotherapy by stimulating the PD-1/PD-L1 pathway to prevent myocardial damage in viral myocarditis. © 2007 European Society of Cardiology.
  • Nanae Kada, Toru Suzuki, Kenichi Aizawa, Takayoshi Matsumura, Naoto Ishibashi, Naomi Suzuki, Norifumi Takeda, Yoshiko Munemasa, Daigo Sawaki, Takashi Ishikawa, Ryozo Nagai
    Arteriosclerosis, thrombosis, and vascular biology 27 7 1535 - 41 2007年07月 [査読有り][通常論文]
     
    OBJECTIVES: Acyclic retinoid (ACR) is a synthetic retinoid with a high safety profile that has been pursued with high expectations for therapeutic use in prevention (recurrence) and treatment of malignancies. With the objective of addressing the therapeutic potential in the cardiovasculature, namely neointima formation, effects of ACR on neointima formation and the involved mechanisms were investigated. METHODS AND RESULTS: ACR was administered to cuff-injured mice which showed inhibition of neointima formation. Investigation of involved mechanisms at the cellular and molecular levels showed that ACR induces apoptosis of neointimal cells and this to be mediated by selective induction of retinoic-acid receptor beta (RARbeta) which shows growth inhibitory and proapoptotic effects on smooth muscle cells. CONCLUSION: We show that ACR inhibits neointima formation by inducing RARbeta which in turn inhibits cell growth and induces apoptosis. The retinoid, ACR, may be potentially exploitable for treatment and prevention of neointima formation.
  • Naoto Kubota, Wataru Yano, Tetsuya Kubota, Toshimasa Yamauchi, Shinsuke Itoh, Hiroki Kumagai, Hideki Kozono, Iseki Takamoto, Shiki Okamoto, Tetsuya Shiuchi, Ryo Suzuki, Hidemi Satoh, Atsushi Tsuchida, Masao Moroi, Kaoru Sugi, Tetsuo Noda, Hiroyuki Ebinuma, Yoichi Ueta, Tatsuya Kondo, Eiichi Araki, Osamu Ezaki, Ryozo Nagai, Kazuyuki Tobe, Yasuo Terauchi, Kohjiro Ueki, Yasuhiko Minokoshi, Takashi Kadowaki
    Cell metabolism 6 1 55 - 68 2007年07月 [査読有り][通常論文]
     
    Adiponectin has been shown to stimulate fatty acid oxidation and enhance insulin sensitivity through the activation of AMP-activated protein kinase (AMPK) in the peripheral tissues. The effects of adiponectin in the central nervous system, however, are still poorly understood. Here, we show that adiponectin enhances AMPK activity in the arcuate hypothalamus (ARH) via its receptor AdipoR1 to stimulate food intake; this stimulation of food intake by adiponectin was attenuated by dominant-negative AMPK expression in the ARH. Moreover, adiponectin also decreased energy expenditure. Adiponectin-deficient mice showed decreased AMPK phosphorylation in the ARH, decreased food intake, and increased energy expenditure, exhibiting resistance to high-fat-diet-induced obesity. Serum and cerebrospinal fluid levels of adiponectin and expression of AdipoR1 in the ARH were increased during fasting and decreased after refeeding. We conclude that adiponectin stimulates food intake and decreases energy expenditure during fasting through its effects in the central nervous system.
  • Motohiro Sekiya, Naoya Yahagi, Takashi Matsuzaka, Yoshinori Takeuchi, Yoshimi Nakagawa, Haruka Takahashi, Hiroaki Okazaki, Yoko Iizuka, Ken Ohashi, Takanari Gotoda, Shun Ishibashi, Ryozo Nagai, Tsutomu Yamazaki, Takashi Kadowaki, Nobuhiro Yamada, Jun-ichi Osuga, Hitoshi Shimano
    Journal of lipid research 48 7 1581 - 91 2007年07月 [査読有り][通常論文]
     
    Sterol regulatory element-binding protein (SREBP)-1c is now well established as a key transcription factor for the regulation of lipogenic enzyme genes such as FAS in hepatocytes. Meanwhile, the mechanisms of lipogenic gene regulation in adipocytes remain unclear. Here, we demonstrate that those in adipocytes are independent of SREBP-1c. In adipocytes, unlike in hepatocytes, the stimulation of SREBP-1c expression by liver X receptor agonist does not accompany lipogenic gene upregulation, although nuclear SREBP-1c protein is concomitantly increased, indicating that the activation process of SREBP-1c by the cleavage system is intact in adipocytes. Supportively, transcriptional activity of the mature form of SREBP-1c for the FAS promoter was negligible when measured by reporter analysis. As an underlying mechanism, accessibility of SREBP-1c to the functional elements was involved, because chromatin immunoprecipitation assays revealed that SREBP-1c does not bind to the functional SRE/E-box site on the FAS promoter in adipocytes. Moreover, genetic disruption of SREBP-1 did not cause any changes in lipogenic gene expression in adipose tissue. In summary, in adipocytes, unlike in hepatocytes, increments in nuclear SREBP-1c are not accompanied by transactivation of lipogenic genes; thus, SREBP-1c is not committed to the regulation of lipogenesis.
  • Kazuto Nakamura, Masataka Sata, Hiroshi Iwata, Yoshiki Sakai, Yasunobu Hirata, Kiyotaka Kugiyama, Ryozo Nagai
    Clinical science (London, England : 1979) 112 12 607 - 16 2007年06月 [査読有り][通常論文]
     
    It has been shown previously that administration of angiogenic growth factors as genes or proteins can augment collateral growth in ischaemic tissues. In the present study, we have investigated the effect of ONO-1301, a synthetic prostacyclin agonist with thromboxane-synthase-inhibitory activity, on expression of endogenous growth factors and angiogenesis. ONO-1301 induced secretion of HGF (hepatocyte growth factor) and VEGF (vascular endothelial growth factor) from cultured normal human dermal fibroblasts in a dose-dependent manner. Dibutyryl cAMP, an analogue of cAMP, and forskolin, an adenylate cyclase activator, mimicked the effect of ONO-1301. Conversely, Rp-cAMP (adenosine 3',5'-cyclic monophosphorothioate), an inhibitor of cAMP, partially inhibited the effect of ONO-1301, suggesting that cAMP mediated the effect of ONO-1301 in up-regulating the expression of HGF and VEGF, at least in part. ONO-1301 promoted tube-like formation by HUVECs (human umbilical vein endothelial cells) when co-cultured with fibroblasts, and the angiogenic effect of ONO-1301 was abrogated by administration of a neutralizing antibody against HGF or VEGF. To generate a slow-releasing form of ONO-1301, ONO-1301 was mixed with poly(DL-lactic-co-glycolic acid). The slow-releasing form of ONO-1301 was injected directly into the ischaemic myocardium of mice immediately after ligation of the left anterior descending artery. The slow-releasing form of ONO-1301 up-regulated HGF and VEGF expression and increased capillary density in the border zone (342.7+/-29.7 capillaries/mm(2) in controls compared with 557.2+/-26.7 capillaries/mm(2) in treated animals; P<0.01) at 7 days. The slow-releasing form of ONO-1301 ameliorated left ventricular enlargement after 28 days and improved survival rate. In conclusion, our results indicate that ONO-1301 up-regulated endogenous growth factors and promoted angiogenesis in response to acute ischaemia. Therefore ONO-1301 might have a therapeutic potential in treating ischaemic diseases.
  • Satoshi Nishimura, Ichiro Manabe, Mika Nagasaki, Yumiko Hosoya, Hiroshi Yamashita, Hideo Fujita, Mitsuru Ohsugi, Kazuyuki Tobe, Takashi Kadowaki, Ryozo Nagai, Seiryo Sugiura
    Diabetes 56 6 1517 - 26 2007年06月 [査読有り][通常論文]
     
    OBJECTIVE: The expansion of adipose tissue mass seen in obesity involves both hyperplasia and hypertrophy of adipocytes. However, little is known about how adipocytes, adipocyte precursors, blood vessels, and stromal cells interact with one another to achieve adipogenesis. RESEARCH DESIGN AND METHODS: We have developed a confocal microscopy-based method of three-dimensional visualization of intact living adipose tissue that enabled us to simultaneously evaluate angiogenesis and adipogenesis in db/db mice. RESULTS: We found that adipocyte differentiation takes place within cell clusters (which we designated adipogenic/angiogenic cell clusters) that contain multiple cell types, including endothelial cells and stromal cells that express CD34 and CD68 and bind lectin. There were close spatial and temporal interrelationships between blood vessel formation and adipogenesis, and the sprouting of new blood vessels from preexisting vasculature was coupled to adipocyte differentiation. CD34(+) CD68(+) lectin-binding cells could clearly be distinguished from CD34(-) CD68(+) macrophages, which were scattered in the stroma and did not bind lectin. Adipogenic/angiogenic cell clusters can morphologically and immunohistochemically be distinguished from crown-like structures frequently seen in the late stages of adipose tissue obesity. Administration of anti-vascular endothelial growth factor (VEGF) antibodies inhibited not only angiogenesis but also the formation of adipogenic/angiogenic cell clusters, indicating that the coupling of adipogenesis and angiogenesis is essential for differentiation of adipocytes in obesity and that VEGF is a key mediator of that process. CONCLUSIONS: Living tissue imaging techniques provide novel evidence of the dynamic interactions between differentiating adipocytes, stromal cells, and angiogenesis in living obese adipose tissue.
  • Nobukazu Ishizaka, Yuko Ishizaka, Ei-Ichi Toda, Hideki Hashimoto, Ryozo Nagai, Minoru Yamakado
    ATHEROSCLEROSIS 192 1 131 - 137 2007年05月 [査読有り][通常論文]
     
    Hyperuricemia is postulated to be a risk factor for atherosclerotic diseases, although whether it is independent of classical atherogenic risk factors is controversial. The automatic computer-assisted measurement of brachial-ankle pulse wave velocity (baPWV) is a valid and reproducible method by which to assess arterial stiffness, a potential surrogate marker of early atherosclerosis. By analyzing cross-sectional data from 982 individuals who underwent health screening, we have investigated whether serum uric acid is associated with high baPWV, which was determined as the highest quartile of baPWV values, in a sex-specific manner. Multivariate analysis showed that the odds ratios (95% CI) of the highest baPWV quartile across the sex-specific quartiles of serum uric acid were 1.0, 2.80 (0.93-8.40), 2.13 (0.74-6.19), and 2.76 (1.01-7.55) in women, and 1.0, 1.10 (0.55-2.20), 1.97 (1.04-3.75), and 2.24 (1.10-4.56) in men after adjusting for age, total and HDL-cholesterol, BMI, systolic blood pressure, triglycerides, fasting glucose and smoking status. The association between uric acid and high baPWV was observed in both subjects with metabolic syndrome and those without. These data suggest that in both genders, serum uric acid level is associated with increased baPWV, a marker of arterial stiffness, and is in part independent of other conventional risk factors for atherosclerosis and metabolic syndrome. (c) 2006 Elsevier Ireland Ltd. All rights reserved.
  • Makoto Sumi, Masataka Sata, Ayako Hashimoto, Takashi Imaizumi, Katsuhiko Yanaga, Takao Ohki, Toyoki Mori, Ryozo Nagai
    BIOMEDICINE & PHARMACOTHERAPY 61 4 209 - 215 2007年05月 [査読有り][通常論文]
     
    OPC-28326,4-(N-methyl-2-phenylethylamino)-1-(3,5-dimethyl-4-propionyl-aminobenzoyl) piperidine hydrochloride monohydrate, is a newly developed selective peripheral vasodilator and increases blood flow to lower extremities with alpha 2-adrenergic antagonist property. Here, we investigated the effect of OPC-28326 on ischemia-induced angiogenesis. OPC-28326 enhanced tube formation by human aortic endothelial cells (HAECs). Moreover, OPC-28326 enhanced the number of microvessels sprouting from aortic rings embedded in collagen gel. OPC-28326 markedly induced phosphorylation of endothelial nitric oxide synthase (eNOS) in HAECs via phosphatidylinositol-3 kinase PI3K/Akt (PI3K/ Akt) pathway. Next, the angiogenic effect of OPC-28326 was evaluated in a mouse hindlimb ischemia model. Blood flow recovery to the ischemic leg was significantly enhanced by OPC-28326. Furthermore, anti-CD31 immunostaining revealed that OPC-28326 increased capillary density in the ischemic muscle. However, OPC-28326 failed to promote blood flow recovery in ischemic hindlimb in eNOS-deficient mice. These results suggest that OPC-28326 promotes angiogenesis, which was associated with activation of eNOS via PI3K/Akt pathway. OPC-28326 might be promising to treat patients with ischemic vascular diseases. (C) 2006 Published by Elsevier Masson SAS.
  • Yoshinori Seko, Akihiro Matsumoto, Taira Fukuda, Yasushi Imai, Tsutomu Fujimura, Hikari Taka, Reiko Mineki, Kimie Murayama, Yasunobu Hirata, Ryozo Nagai
    International heart journal 48 3 407 - 15 2007年05月 [査読有り][通常論文]
     
    Patients with neonatal lupus erythematosus (NLE) often have congenital heart block with or without heart failure and are born to mothers who have anti-SS-A and/or anti-SS-B antibodies. NLE has been considered to result from the placental transmission of maternal autoantibodies into the fetal circulation causing myocardial damage. We report a case of NLE with congenital heart block who had undergone pacemaker implantation at the age of 17, and then developed dilated cardiomyopathy (DCM) at the age of 19, which is much later than in most other cases. The patient's mother was positive for anti-SS-A and anti-SS-B antibodies, whereas the patient was negative for both anti-SS-A and anti-SS-B antibodies. There were some autoantibodies against cell surface antigens of cardiac myocytes in the serum from the patient, and annexin A6 was identified as one of the autoantigens. This is the first report demonstrating that annexin A6 is involved in the myocardial injury in patients with NLE. The results indicate that inhibition of annexin A6 function may prevent autoantibody-mediated myocardial injury in at least some cases of DCM.
  • Takayuki Ohno, Shinichi Takamoto, Jiro Ando, Toshihiro Morita, Hideo Fujita, Yasunobu Hirata, Takashi Shigeeda, Akira Hirose, Ryozo Nagai
    Journal of interventional cardiology 20 2 122 - 31 2007年04月 [査読有り][通常論文]
     
    INTRODUCTION: The prognostic value of identifying the retinal status of diabetic patients undergoing coronary implantation of drug-eluting stents is unknown. METHODS: We evaluated the outcomes of 318 consecutive patients undergoing implantation of sirolimus-eluting stents for coronary artery disease. Patients were divided into 5 groups according to the diabetic and retinal status: diabetic patients without retinopathy (43 patients); diabetic patients with nonproliferative retinopathy (34); diabetic patients with proliferative retinopathy (37); diabetic patients with unknown retinal status (30); and nondiabetic patients (174). RESULTS: During a mean follow-up of 385 days, 64 patients had target-vessel failure (defined as a composite of death from cardiac causes, myocardial infarction, and target-vessel revascularization). At 1 year, Kaplan-Meier estimates of the rate of target-vessel failure were 15.3% for diabetic patients without retinopathy, 56.6% for those with nonproliferative retinopathy, 17.3% for those with proliferative retinopathy, 19.0% for those with unknown retinal status, and 16.0% for nondiabetic patients. After adjustment for the potential confounders and differences between groups, the relation of nonproliferative retinopathy to target-vessel failure remained significant. In an analysis in which diabetic patients without retinopathy were used as the reference group, the hazard ratios for target-vessel failure were 3.9 for those with nonproliferative retinopathy, 1.3 for those with proliferative retinopathy, 1.1 for those with unknown retinal status, and 1.4 for nondiabetic patients (P for trend = 0.015). CONCLUSIONS: As compared with diabetic patients without retinopathy, those with nonproliferative retinopathy have an increased risk for target-vessel failure after coronary implantation of sirolimus-eluting stents.
  • 武田 憲文, 平田 恭信, 永井 良三
    呼吸と循環 55 4 441 - 447 (株)医学書院 2007年04月 [査読有り][通常論文]
  • 小野 祥太郎, 武田 憲文, 今井 靖, 高橋 政夫, 石坂 信和, 平田 恭信, 永井 良三, 本村 昇, 小野 稔, 高本 眞一
    Circulation Journal 71 Suppl.II 820 - 820 (一社)日本循環器学会 2007年04月 [査読有り][通常論文]
  • M Horikoshi, K Hara, C Ito, R Nagai, P Froguel, T Kadowaki
    Diabetologia 50 4 747 - 51 2007年04月 [査読有り][通常論文]
     
    AIMS/HYPOTHESIS: It has been suggested that transcription factor 7-like 2 protein (TCF7L2) plays an important role in glucose metabolism by regulating the production level of glucagon-like peptide-1, a hormone which modifies glucose-dependent insulin secretion. Recently, variants of TCF7L2 gene were reported to confer an increased risk of type 2 diabetes in three different samples from European and European-origin populations. We studied whether the single nucleotide polymorphisms (SNPs) in TCF7L2 were associated with type 2 diabetes in samples from a Japanese population. METHODS: Five SNPs were genotyped in three different sample sets. Association with type 2 diabetes was investigated in each, as well as in combined sample sets. RESULTS: The SNP rs7903146 was nominally associated with type 2 diabetes in the initial (p = 0.08) and two replication sample sets (p = 0.05 and 0.06). For the combined sample set, in which we successfully genotyped 1,174 type 2 diabetes patients and 823 control subjects, rs7903146 showed a significant association with type 2 diabetes (odds ratio = 1.69 [95% CI 1.21-2.36], p = 0.002) with the same direction as the previous reports in samples from European and European-origin populations. SNPs rs7903146 and rs7901695 were in complete linkage disequilibrium. The rest of the five SNPs (rs7895340, rs11196205 and rs12255372) did not show any significant associations with type 2 diabetes. CONCLUSIONS/INTERPRETATION: The consistent association between rs7903146 in TCF7L2 and type 2 diabetes in different ethnic groups, including the Japanese population, suggests that TCF7L2 is a common susceptibility gene for type 2 diabetes.
  • Nobukazu Ishizaka, Yuko Ishizaka, Ei-Ichi Toda, Ryozo Nagai, Minoru Yamakado
    JOURNAL OF ATHEROSCLEROSIS AND THROMBOSIS 14 2 72 - 77 2007年04月 [査読有り][通常論文]
     
    Aim: We have investigated whether metabolic syndrome is a risk factor for carotid atherosclerosis also in normotensive or prehypertensive individuals. Methods: We analyzed the data from 851 subjects who had a blood pressure of less than 140/90 mmHg and were not taking antihypertensive medication. Metabolic syndrome was defined according to three different criteria: Japan criteria (Japan-MetS); those of the National Cholesterol Education Program (NCEP)-Adult Treatment Panel M (ATP III) (NCEP-MetS); and modified NCEP-ATP III criteria in which body mass index was used as a surrogate for waist circumference (modified NCEP-MetS). Results: Japan-MetS, NCEP-MetS, and modified NCEP-MetS were found, respectively, in 1%, 4%, and 4%, of women, and in 10%, 5%, and 9%, of men. After the adjustment for gender and age, the association between MetS and carotid atherosclerosis did not reach statistical significance. Conclusion: Although the number of enrolled subjects was relatively small, these data may further support the importance of controlling blood pressure within the optimal range for the purpose of preventing atherosclerosis in individuals with metabolic syndrome.
  • Makoto Sumi, Masataka Sata, Shin-ichiro Miura, Kerry-Anne Rye, Naoki Toya, Yuji Kanaoka, Katsuhiko Yanaga, Takao Ohki, Keijiro Saku, Ryozo Nagai
    ARTERIOSCLEROSIS THROMBOSIS AND VASCULAR BIOLOGY 27 4 813 - 818 2007年04月 [査読有り][通常論文]
     
    Background - Plasma high-density lipoprotein (HDL) levels have an inverse correlation with incidence of ischemic heart disease as well as other atherosclerosis-related ischemic conditions. However, the molecular mechanism by which HDL prevents ischemic disease is not fully understood. Here, we investigated the effect of HDL on differentiation of endothelial progenitor cells and angiogenesis in murine ischemic hindlimb model. Methods and Results - Intravenous injection of reconstituted HDL (rHDL) significantly augmented blood flow recovery and increased capillary density in the ischemic leg. rHDL increased the number of bone marrow - derived cells incorporated into the newly formed capillaries in ischemic muscle. rHDL induced phosphorylation of Akt in human peripheral mononuclear cells. rHDL (50 to 100 mu g apolipoprotein A-I/mL) promoted differentiation of peripheral mononuclear cells to endothelial progenitor cells in a dose-dependent manner. The effect of rHDL on endothelial progenitor cells differentiation was abrogated by coadministration of LY294002, an inhibitor of phosphatidylinositol 3-kinase. rHDL failed to promote angiogenesis in endothelial NO - deficient mice. Conclusions - rHDL directly stimulates endothelial progenitor cell differentiation via phosphatidylinositol 3-kinase/Akt pathway and enhances ischemia-induced angiogenesis. rHDL may be useful in the treatment of patients with ischemic cardiovascular diseases.
  • Toru Suzuki, Toshiya Nishi, Tomoko Nagino, Kana Sasaki, Kenichi Aizawa, Nanae Kada, Daigo Sawaki, Yoshiko Munemasa, Takayoshi Matsumura, Shinsuke Muto, Masataka Sata, Kiyoshi Miyagawa, Masami Horikoshi, Ryozo Nagai
    The Journal of biological chemistry 282 13 9895 - 901 2007年03月 [査読有り][通常論文]
     
    Krüppel-like factor 5 (KLF5) is a transcription factor important in regulation of the cardiovascular response to external stress. KLF5 regulates pathological cell growth, and its acetylation is important for this effect. Its mechanisms of action, however, are still unclear. Analysis in KLF5-deficient mice showed that KLF5 confers apoptotic resistance in vascular lesions. Mechanistic analysis further showed that it specifically interacts with poly(ADP-ribose) polymerase-1 (PARP-1), a nuclear enzyme important in DNA repair and apoptosis. KLF5 interacted with a proteolytic fragment of PARP-1, and acetylation of KLF5 under apoptotic conditions increased their affinity. Moreover, KLF5 wild-type (but not a non-acetylatable point mutant) inhibited apoptosis as induced by the PARP-1 fragment. Collectively, we have found that KLF5 regulates apoptosis and targets PARP-1, and further, for acetylation to regulate these effects. Our findings thus implicate functional interaction between the transcription factor KLF5 and PARP-1 in cardiovascular apoptosis.
  • Shinsuke Muto, Miki Senda, Yusuke Akai, Lui Sato, Toru Suzuki, Ryozo Nagai, Toshiya Senda, Masami Horikoshi
    Proceedings of the National Academy of Sciences of the United States of America 104 11 4285 - 90 2007年03月 [査読有り][通常論文]
     
    Histone chaperones assemble and disassemble nucleosomes in an ATP-independent manner and thus regulate the most fundamental step in the alteration of chromatin structure. The molecular mechanisms underlying histone chaperone activity remain unclear. To gain insights into these mechanisms, we solved the crystal structure of the functional domain of SET/TAF-Ibeta/INHAT at a resolution of 2.3 A. We found that SET/TAF-Ibeta/INHAT formed a dimer that assumed a "headphone"-like structure. Each subunit of the SET/TAF-Ibeta/INHAT dimer consisted of an N terminus, a backbone helix, and an "earmuff" domain. It resembles the structure of the related protein NAP-1. Comparison of the crystal structures of SET/TAF-Ibeta/INHAT and NAP-1 revealed that the two proteins were folded similarly except for an inserted helix. However, their backbone helices were shaped differently, and the relative dispositions of the backbone helix and the earmuff domain between the two proteins differed by approximately 40 degrees . Our biochemical analyses of mutants revealed that the region of SET/TAF-Ibeta/INHAT that is engaged in histone chaperone activity is the bottom surface of the earmuff domain, because this surface bound both core histones and double-stranded DNA. This overlap or closeness of the activity surface and the binding surfaces suggests that the specific association among SET/TAF-Ibeta/INHAT, core histones, and double-stranded DNA is requisite for histone chaperone activity. These findings provide insights into the possible mechanisms by which histone chaperones assemble and disassemble nucleosome structures.
  • Shiga Taro, Maemura Koji, Imai Yasushi, Kawanami Daiji, Takeda Norihiko, Ando Jiro, Morita Toshihiro, Manabe Ichiro, Hayashi Dobun, Ohtsu Hiroshi, Sugiyama Akira, Miyamoto Kyoko, Sagara Mina, Ito Yukio, Yamazaki Tsutomu, Hirata Yasunobu, Kodama Tatsuhiko, Nagai Ryozo
    JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY 49 9 377A  2007年03月 [査読有り][通常論文]
  • Wang Guoqin, Imai Yasushi, Watanabe Masafumi, Manabe Ichiro, Kohro Takahide, Monzen Koshiro, Hayashi Dobun, Maemura Koji, Yamazaki Tsutomu, Nagai Ryozo
    Circulation Journal 71 Suppl.I 307 - 307 2007年03月
  • Masatoshi Fujita, Tsutomu Yamazaki, Dobun Hayashi, Ryozo Nagai
    JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY 49 9 344A - 345A 2007年03月 [査読有り][通常論文]
  • Toshimasa Yamauchi, Yasunori Nio, Toshiyuki Maki, Masaki Kobayashi, Takeshi Takazawa, Masato Iwabu, Miki Okada-Iwabu, Sachiko Kawamoto, Naoto Kubota, Tetsuya Kubota, Yusuke Ito, Junji Kamon, Atsushi Tsuchida, Katsuyoshi Kumagai, Hideki Kozono, Yusuke Hada, Hitomi Ogata, Kumpei Tokuyama, Masaki Tsunoda, Tomohiro Ide, Kouji Murakami, Motoharu Awazawa, Iseki Takamoto, Philippe Froguel, Kazuo Hara, Kazuyuki Tobe, Ryozo Nagai, Kohjiro Ueki, Takashi Kadowaki
    Nature medicine 13 3 332 - 9 2007年03月 [査読有り][通常論文]
     
    Adiponectin plays a central role as an antidiabetic and antiatherogenic adipokine. AdipoR1 and AdipoR2 serve as receptors for adiponectin in vitro, and their reduction in obesity seems to be correlated with reduced adiponectin sensitivity. Here we show that adenovirus-mediated expression of AdipoR1 and R2 in the liver of Lepr(-/-) mice increased AMP-activated protein kinase (AMPK) activation and peroxisome proliferator-activated receptor (PPAR)-alpha signaling pathways, respectively. Activation of AMPK reduced gluconeogenesis, whereas expression of the receptors in both cases increased fatty acid oxidation and lead to an amelioration of diabetes. Alternatively, targeted disruption of AdipoR1 resulted in the abrogation of adiponectin-induced AMPK activation, whereas that of AdipoR2 resulted in decreased activity of PPAR-alpha signaling pathways. Simultaneous disruption of both AdipoR1 and R2 abolished adiponectin binding and actions, resulting in increased tissue triglyceride content, inflammation and oxidative stress, and thus leading to insulin resistance and marked glucose intolerance. Therefore, AdipoR1 and R2 serve as the predominant receptors for adiponectin in vivo and play important roles in the regulation of glucose and lipid metabolism, inflammation and oxidative stress in vivo.
  • Kazuo Hara, Toshimasa Yamauchi, Yasushi Imai, Ichiro Manabe, Ryozo Nagai, Takashi Kadowaki
    International heart journal 48 2 149 - 53 2007年03月 [査読有り][通常論文]
     
    Adipocyte-derived adiponectin has an antiatherosclerotic effect that acts independently of its antidiabetic effect. Plasma adiponectin levels are generally low in subjects with coronary artery disease. In this study, the relationship between the plasma adiponectin level and the severity of coronary artery disease, as assessed using the Gensini score, an index for the severity of coronary artery stenosis, was investigated. The subjects of the study were 104 patients (72 men and 32 women; BMI, 23.5 +/- 3.3 kg/m(2); age, 63.6 +/- 10.1 years) admitted to Tokyo University Hospital for coronary angiography. Plasma adiponectin levels were inversely correlated with the insulin resistance index HOMA-IR (P = 0.0127). The plasma adiponectin level was significantly associated with the Gensini score (P = 0.0332). After adjustment for conventional risk factors for cardiovascular diseases, the plasma adiponectin level tended to be inversely correlated with the Gensini score (P = 0.087). The measurement of plasma adiponectin levels may be useful for predicting the severity of coronary artery stenosis.
  • Ryoichi Shimamoto, Jun-ichi Suzuki, Tadashi Yamazaki, Taeko Tsuji, Yuki Ohmoto, Toshihiro Morita, Hiroshi Yamashita, Junko Honye, Ryozo Nagai, Masaaki Akahane, Kuni Ohtomo
    Radiography 13 1 44 - 50 2007年02月 [査読有り][通常論文]
     
    Purpose: Coronary artery vascular edge recognition on computed tomography (CT) angiograms is influenced by window parameters. A noninvasive method for vascular edge recognition independent of window setting with use of multi-detector row CT was contrived and its feasibility and accuracy were estimated by intravascular ultrasound (IVUS). Methods: Multi-detector row CT was performed to obtain 29 CT spatial profile curves by setting a line cursor across short-axis coronary angiograms processed by multi-planar reconstruction. IVUS was also performed to determine the reference coronary diameter. IVUS diameter was fitted horizontally between two points on the upward and downward slopes of the profile curves and Hounsfield number was measured at the fitted level to test seven candidate indexes for definition of intravascular coronary diameter. The best index from the curves should show the best agreement with IVUS diameter. Results: Of the seven candidates the agreement was the best (agreement: 16 ± 11%) when the two ratios of Hounsfield number at the level of IVUS diameter over that at the peak on the profile curves were used with water and with fat as the background tissue. These edge definitions were achieved by cutting the horizontal distance by the curves at the level defined by the ratio of 0.41 for water background and 0.57 for fat background. Conclusions: Vascular edge recognition of the coronary artery with CT spatial profile curves was feasible and the contrived method could define the coronary diameter with reasonable agreement. © 2005 The College of Radiographers.
  • Nobukazu Ishizaka, Kan Saito, Kyoko Furuta, Gen Matsuzaki, Kazuhiko Koike, Eisei Noiri, Ryozo Nagai
    HYPERTENSION RESEARCH 30 2 195 - 202 2007年02月 [査読有り][通常論文]
     
    Due to recent discoveries of novel genes involved in iron metabolism, our understanding of the molecular mechanisms underlying iron metabolism has dramatically increased. We have previously shown that the administration of angiotensin II alters iron homeostasis in the rat kidney, which may in turn aggravate angiotensin II-induced renal damage. Here we have investigated the effect of angiotensin II administration on the localization and expression of transferrin receptor (TfR), divalent metal transporter 1 (DMT1), ferroportin 1 (FPN), and hepcidin mRNA in the rat kidney. Weak expression of TfR, DMT1, FPN, and hepcidin mRNA was observed in the kidneys of control rats. In contrast, after 7 days of angiotensin II infusion by osmotic minipump, the expression of these mRNAs was more widely distributed. Staining of serial sections revealed that some, but not all, of the renal tubular cells positive for these genes contained iron deposits in the kidney of angiotensin II-infused animals. Real-time polymerase chain reaction (PCR) showed that the mRNA expression of TfR, iron-responsive element-negative DMT1, FPN, and hepcidin mRNA increased similar to 1.9-fold, similar to 1.7-fold, similar to 2.3-fold, and similar to 4.7-fold, respectively, after angiotensin II infusion as compared with that of untreated controls, and that these increases could be suppressed by the concomitant administration of losartan. Our data demonstrate that these genes were unequivocally expressed in the kidney and could be regulated by angiotensin II infusion. The relative contribution, if any, of these genes to renal and/or whole-body iron homeostasis in various disorders in which the renin angiotensin system is activated should be investigated in future studies.
  • Ibuki Shirakawa, Masataka Sata, Akio Saiura, Yukari Kaneda, Hisako Yashiro, Yasunobu Hirata, Masatoshi Makuuchi, Ryozo Nagai
    BIOMEDICINE & PHARMACOTHERAPY 61 2-3 154 - 159 2007年02月 [査読有り][通常論文]
     
    Accelerated coronary arteriosclerosis remains a major problem for the long-term survival of cardiac transplant recipients. However, the pathogenesis of transplant vasculopathy is poorly understood and there is no effective therapy. HMG-CoA reductase inhibitors, or statins, are widely prescribed to lower plasma cholesterol level. Accumulating evidence indicates that statins have various effects on vascular cells which are independent of their lipid-lowering effect. We investigated whether orally administered atorvastatin, one of the most potent statins, inhibits the development of intima hyperplasia in a mouse model of cardiac transplantation. Cardiac allografts from DBA mice were transplanted heterotopically into B10.D2 mice. Mice were administered either vehicle or atorvastatin everyday by gavage. Morphometrical analysis revealed that atorvastatin significantly reduced the development of coronary arteriosclerosis on the cardiac allografts harvested at one month. Immunohistochemical analysis revealed that atorvastatin attenuated infiltration of inflammatory cells with reduced expression of TGF-beta and adhesion molecules. These results suggest that atorvastatin may be effective in preventing transplant-associated arteriosclerosis along with other immunosuppressive agents. (c) 2007 Elsevier Masson SAS. All rights reserved.
  • Tsuyoshi Uchiyama, Hiroyuki Atsuta, Toshihiro Utsugi, Masato Oguri, Akira Hasegawa, Tetsuya Nakamura, Akira Nakai, Masanori Nakata, Ikuro Maruyama, Hideaki Tomura, Fumikazu Okajima, Shoichi Tomono, Shoji Kawazu, Ryozo Nagai, Masahiko Kurabayashi
    Atherosclerosis 190 2 321 - 9 2007年02月 [査読有り][通常論文]
     
    We have been examining the role of heat shock factor 1 (HSF1) in the pleiotropic effects of statins. In parallel studies, we found that statin induces the nuclear translocation of HSF1 and that a decoy oligonucleotide encoding the heat shock element inhibits the statin-induced expression of heat shock protein 70, endothelial nitric oxide synthase (eNOS) and thrombomodulin. Also, in vascular endothelial cells, increases in the expression of human HSF1 corresponded with elevated steady-state levels of eNOS and thrombomodulin and reduced levels of endothelin-1 and plasminogen activator inhibitor-1. We also found that heat shock proteins induced eNOS and thrombomodulin expression and reduced PAI-1 and ET-1 expression. In particular, a combination of HSP70 and HSP90 strongly induced eNOS expression and reduced PAI-1 expression. In the current studies, we generated a constitutively active form of HSF1 and found that it is more effective than the wild-type HSF at inducing thrombomodulin and eNOS expression and decreasing endothelin-1 and plasminogen activator inhibitor-1 expression. These results show that the wild-type and constitutively active forms of HSF1 induce anticoagulation and relaxation factors in vascular endothelial cells and could therefore be used to treat cardiovascular disease.
  • Maemura K, Takeda N, Nagai R
    Journal of pharmacological sciences 103 2 134 - 138 2007年02月 [査読有り][通常論文]
  • Makoto Sahara, Masataka Sata, Toshihiro Morita, Kazuto Nakamura, Yasunobu Hirata, Ryozo Nagai
    Circulation 115 4 509 - 17 2007年01月 [査読有り][通常論文]
     
    BACKGROUND: Recent evidence suggests that bone marrow (BM)-derived cells may differentiate into vascular cells that participate in arterial repair and/or lesion formation. However, it remains uncertain whether BM-derived cells also can participate in vascular remodeling associated with pulmonary arterial hypertension. METHODS AND RESULTS: The BM of Sprague-Dawley rats was reconstituted with that of green fluorescent protein-transgenic rats. The BM-chimeric rats were injected intraperitoneally with 60 mg/kg monocrotaline after unilateral subpneumonectomy, and they concurrently underwent wire-mediated endovascular injury in femoral artery. After 28 days, they had elevated right ventricular systolic pressure (58.8+/-5.4 versus 20.4+/-2.4 mm Hg in sham-control; P<0.01). The pulmonary arterioles were markedly thickened, with an infiltration of green fluorescent protein-positive macrophages into the perivascular areas. The endothelium of pulmonary arterioles contained only a few green fluorescent protein-positive cells, and green fluorescent protein-positive cells were seldom detected as smooth muscle cells in the lesions of thickened pulmonary arterioles. In contrast, BM-derived smooth muscle-like cells could be readily detected in the thickened neointima and media of the wire-injured femoral artery. Moreover, intravenous injection of 1x10(8) BM cells from young rats had no beneficial effects on pulmonary hypertension, pulmonary arterial remodeling, or survival in the aged rats treated with monocrotaline plus unilateral subpneumonectomy. No injected BM cell was identified as an endothelial cell or a smooth muscle cell. CONCLUSIONS: These results suggest that BM-derived cells can participate in arterial neointimal formation after mechanical injury, whereas they do not contribute substantially to pulmonary arterial remodeling associated with monocrotaline-induced pulmonary arterial hypertension in the pneumonectomized rats.
  • Norifumi Takeda, Jun Nakajima, Namie Yamada, Yukio Hiroi, Yasunobu Hirata, Ryozo Nagai
    Respiratory Medicine Extra 3 2 76 - 78 2007年 [査読有り][通常論文]
     
    Mediastinal bronchogenic cysts are frequently detected incidentally in adults. Here, we present a unique case of atypical clinical course of bronchogenic cyst beneath the carina, which ruptured into the pericardium. We could not diagnose definitely at initial admission, even though the massive pericardial fluid was exudative with high carbohydrate antigen (CA) 19-9 production. The fluid cytology was negative for malignancy. Five years later, the regrown and unruptured bronchogenic cyst caused atrial fibrillation by impinging on the heart with a high level of serum CA19-9. After resection of the CA19-9-enriched cyst by thoracoscopic surgery, he was discharged without recurrence of atrial fibrillation or any chest symptoms, and the serum CA19-9 level decreased to within the normal range. Differential diagnosis of cytology negative pericardial effusion with high CA19-9 production may be difficult, however, intrapericardial rupture of bronchogenic cyst should be considered in some patients. © 2007 Elsevier Ltd. All rights reserved.
  • Kensaku Nishihira, Takuroh Imamura, Kinta Hatakeyama, Atsushi Yamashita, Yoshisato Shibata, Haruhiko Date, Ichiro Manabe, Ryozo Nagai, Kazuo Kitamura, Yujiro Asada
    Thrombosis research 121 2 275 - 9 2007年 [査読有り][通常論文]
  • Kentaro Meguro, Takuji Toyama, Hitoshi Adachi, Shigeru Ohshima, Koichi Taniguchi, Ryozo Nagai
    ANNALS OF NUCLEAR MEDICINE 21 1 73 - 78 2007年01月 [査読有り][通常論文]
     
    Objective: Iodine-123 MIBG imaging has been used to study cardiac sympathetic function in various cardiac diseases. Central sleep apnea syndrome (CSAS) occurs frequently in patients with chronic heart failure (CHF) and is reported to be associated with a poor prognosis. One of the mechanisms of its poor prognosis may be related to impaired cardiac sympathetic activity. However, the relationship between chemosensitivity to carbon dioxide, which is reported to correlate with the severity of CSAS, and cardiac sympathetic activity has not been investigated. Therefore, this study was undertaken to assess cardiac sympathetic function and chemosensitivity to carbon dioxide in CHF patients. Methods: The oxygen desaturation index (ODI) was evaluated in 21 patients with dilated cardiomyopathy (male/female: 19/2, LVEF < 45%, 65 +/- 12 yr). Patients with an ODI > 5 times/h underwent polysomnography. Patients with an apnea hypopnea index > 15/h but without evidence of obstructive apnea were defined as having CSAS. Early (15 min) and delayed (4 hr) planar MIBG images were obtained from these patients. The mean counts in the whole heart and the mediastinum were obtained. The heart-to-mediastinum count ratio of the delayed image (HIM) and the corrected myocardial washout rate (WR) were also calculated. The central chemoreflex was assessed with the rebreathing method using a hypercapnic gas mixture (7% CO2 and 93% O-2). Results: Ten of the 21 patients had CSAS. The H/M ratio was similar in patients both with and without CSAS (1.57 +/- 0.18 vs. 1.59 +/- 0.14, p = 0.82). However, the WR was higher in patients with CSAS than in patients without CSAS (40 +/- 8% vs. 30 +/- 12%, p < 0.05). ODI significantly correlated with central chemosensitivity to carbon dioxide. Moreover, there was a highly significant correlation between WR and central chemosensitivity (r = 0.65, p < 0.05). However, there was no correlation between ODI and the WR (r = 0.36, p = 0.11). Conclusions: Cardiac sympathetic nerve activity in patients with CHF and CSAS is impaired. However, central sleep apnea might not directly increase cardiac sympathetic nerve activity. We suggest that central chemosensitivity, which is considered to be one of the mechanisms of CSAS, is correlated with cardiac sympathetic nerve activity.
  • Kazuo Asada, Masaru Hatano, Norihiko Takeda, Yasutomi Higashikuni, Kan Saito, Nobukazu Ishizaka, Yasunobu Hirata, Ryozo Nagai
    Internal medicine (Tokyo, Japan) 46 15 1267 - 8 2007年 [査読有り][通常論文]
  • Makoto Sumi, Masataka Sata, Naoki Toya, Katsuhiko Yanaga, Takao Ohki, Ryozo Nagai
    LIFE SCIENCES 80 6 559 - 565 2007年01月 [査読有り][通常論文]
     
    Therapeutic angiogenesis has emerged as a promising therapy to treat patients with ischemic diseases. Transplantation of bone marrow cells (BMCs) is reported to augment collateral development in ischemic organs either by differentiating into vascular cells or by secreting angiogenic cytokines. Recent evidence suggests that adipose tissues secrete a number of humoral factors and contain pluripotent stem cells. Here, we evaluated the therapeutic potential of adipose tissue-derived cells to promote angiogenesis in a mouse model of hind limb ischemia. Stromal vascular fraction cells (SVFs) were isolated from inguinal adipose tissue. Endothelial-like cells or smooth muscle-like cells could be obtained from the culture of SVFs in the presence of growth factors. Freshly isolated BMCs, SVFs, or mature adipocytes were transplanted into the ischemic hind limb of mice. SVFs significantly augmented collateral development as determined by the restoration of blood perfusion and capillary density of the ischemic muscle. Angiogenic effects of SVFs were as potent as those of BMCs. Mature adipocytes showed no proangiogenic effects. The ischemic muscle contained endothelial cells or smooth muscle cells that derived from the transplanted SVFs and BMCs. These results suggest that SVFs might be used to promote angiogenesis in ischemic tissues. (c) 2006 Elsevier Inc. All rights reserved.
  • Yasuo Terauchi, Iseki Takamoto, Naoto Kubota, Junji Matsui, Ryo Suzuki, Kajuro Komeda, Akemi Hara, Yukiyasu Toyoda, Ichitomo Miwa, Shinichi Aizawa, Shuichi Tsutsumi, Yoshiharu Tsubamoto, Shinji Hashimoto, Kazuhiro Eto, Akinobu Nakamura, Mitsuhiko Noda, Kazuyuki Tobe, Hiroyuki Aburatani, Ryozo Nagai, Takashi Kadowaki
    The Journal of clinical investigation 117 1 246 - 57 2007年01月 [査読有り][通常論文]
     
    Glucokinase (Gck) functions as a glucose sensor for insulin secretion, and in mice fed standard chow, haploinsufficiency of beta cell-specific Gck (Gck(+/-)) causes impaired insulin secretion to glucose, although the animals have a normal beta cell mass. When fed a high-fat (HF) diet, wild-type mice showed marked beta cell hyperplasia, whereas Gck(+/-) mice demonstrated decreased beta cell replication and insufficient beta cell hyperplasia despite showing a similar degree of insulin resistance. DNA chip analysis revealed decreased insulin receptor substrate 2 (Irs2) expression in HF diet-fed Gck(+/-) mouse islets compared with wild-type islets. Western blot analyses confirmed upregulated Irs2 expression in the islets of HF diet-fed wild-type mice compared with those fed standard chow and reduced expression in HF diet-fed Gck(+/-) mice compared with those of HF diet-fed wild-type mice. HF diet-fed Irs2(+/-) mice failed to show a sufficient increase in beta cell mass, and overexpression of Irs2 in beta cells of HF diet-fed Gck(+/-) mice partially prevented diabetes by increasing beta cell mass. These results suggest that Gck and Irs2 are critical requirements for beta cell hyperplasia to occur in response to HF diet-induced insulin resistance.
  • Takayoshi Matsumura, Toru Suzuki, Nanae Kada, Kenichi Aizawa, Yoshiko Munemasa, Ryozo Nagai
    Biochemical and biophysical research communications 351 4 965 - 71 2006年12月 [査読有り][通常論文]
     
    Protein profiling would aid in better understanding the pathophysiology of metabolic disease. Here, we report on differential proteomic analysis using an animal model of diabetes mellitus and associated metabolic disorders (Otsuka Long-Evans Tokushima Fatty rat). Serum was analyzed by a new two-dimensional liquid chromatography system which separated proteins by chromatofocusing and subsequent reversed-phase chromatography. This is the first application of this approach to differential serum proteomics. Differentially expressed proteins, identified with MALDI-TOF mass spectrometry, included apolipoproteins and alpha2-HS-glycoprotein. These findings add to our understanding of the underlying pathophysiology. This new proteomic analysis is a promising tool to elucidate disease mechanisms.
  • Yumiko Oishi, Ichiro Manabe, Ryozo Nagai
    Nihon rinsho. Japanese journal of clinical medicine 64 Suppl 9 254 - 8 2006年12月 [査読有り][通常論文]
  • Kazuyuki Hanajiri, Toshiyuki Maruyama, Yukio Kaneko, Hiroshi Mitsui, Shunsuke Watanabe, Masataka Sata, Ryozo Nagai, Takeshi Kashima, Junji Shibahara, Masao Omata, Yoichiro Matsumoto
    Hepatology Research 36 4 308 - 314 2006年12月 [査読有り][通常論文]
     
    We studied the possibility of using high-intensity focused ultrasound (HIFU) together with a microbubble agent to treat hepatocellular carcinoma. Development of liver tumors in rats was induced by administration of Dimethylnitrosamin (100 ppm). Rats with liver tumors were anesthetized, underwent laparotomy, and were given the microbubble agent Levovist or saline intravenously. After the injection, the liver was exposed to HIFU for 30 s (2.18 MHz, 600 W/cm2, 40 mm in diameter). Immediately after HIFU exposure, ultrasound images of the HIFU area were evaluated. Then the liver was excised and the volume of coagulated tissue was measured. The mean volumes of hyperechoic areas after HIFU were as follows (mm3, Levovist versus saline: 355.3 ± 180.7 versus 47.4 ± 35.6, P < 0.001, n = 13). The volumes of liver tissue coagulated by HIFU were as follows (mm3, Levovist versus saline: 275.3 ± 120.0 versus 60.1 ± 23.6, P < 0.001, n = 13). On microscopic examination of areas exposed to HIFU, implosion cysts were seen, and many cancer cells were found to have been destroyed completely (loss of cell membranes or nuclei). In conclusion, the microbubble agent Levovist can increase the volume of tissue coagulated by HIFU. © 2006 Elsevier Ireland Ltd. All rights reserved.
  • Satoshi Nishimura, Yasuo Kawai, Toshiaki Nakajima, Yumiko Hosoya, Hideo Fujita, Masayoshi Katoh, Hiroshi Yamashita, Ryozo Nagai, Seiryo Sugiura
    Cardiovascular research 72 3 403 - 11 2006年12月 [査読有り][通常論文]
     
    OBJECTIVE: To elucidate the interdependence between the mechanical state of the myocardium and its electrical activity, previous studies have been performed at the cellular level. However, the information to date has been limited by the technical difficulties associated with stretching single myocytes. METHODS: We solved this problem by combining two techniques, namely a carbon fiber technique for stretching rat myocytes with wide ranges of amplitude and speed, and ratiometric measurement of a fluorescent indicator (di8-ANEPPS) for evaluating the membrane potential in the non-contact mode. RESULTS: During systole, stretching caused depolarization that prolonged the action potential duration without affecting the peak amplitude, but the effect was only significant in the late phase. Application of a stretch to quiescent myocytes depolarized the membrane potential in amplitude- and speed-dependent manners, but the response was suppressed by cytochalasin D treatment, suggesting participation of the cytoskeleton in the mechanotransduction mechanism. Finally, ion replacement experiments revealed that although Na+ was the dominant charge carrier for large amplitude stretches, Ca2+ permeation was involved in small amplitude stretches, suggesting amplitude-dependent ion selectivity. CONCLUSIONS: Application of axial stretching to rat ventricular myocytes changed the membrane potential in phase-, amplitude- and speed-dependent manners. Amplitude may also modulate the ion selectivity of stretch-activated channels.
  • Nobukazu Ishizaka, Gen Matsuzaki, Kan Saito, Eisei Noiri, Ichiro Mori, Ryozo Nagai
    LABORATORY INVESTIGATION 86 12 1285 - 1292 2006年12月 [査読有り][通常論文]
     
    Lipid accumulation in the kidney is a marker of tissue damage and may play a role in the development of renal injury. We have previously shown that long-term administration of angiotensin 11 in rats causes increased expression of transforming growth factor-beta 1, coupled with an accumulation of lipids in the tubular and vascular wall cells in the kidney. In this study, we examine the regulation of expression of platelet-derived growth factor (PDGF) and its receptor system and their co-locallization with lipid deposits in the kidneys of angiotensin II-infused rats. Real-time RT-PCR showed that expression of PDGF-B, PDGF-D, and PDGIF receptor-beta (PDGFR-beta) mRNA was increased by angiotensin 11 infusion, and in situ hybridization showed the co-localization of these mRNAs. Tubular cells that had increased PDGF-B mRNA expression were positive for lipid deposition and also for cellular proliferation, which was indicated by the presence of proliferating cell nuclear antigen. By contrast, in the kidneys of angiotensin II-infused rats, apoptosis occurred in tubular cells that contained deposits of iron but not lipids. The deposition of lipids and upregulation of PDGF-B, PDGF-D, and PDGFR-beta induced by administration of angiotensin 11 were all suppressed by the selective angiotensin 11 type 1 (AT,) receptor antagonist losartan, but not by the nonspecific vasodilator hydralazine. The findings that lipid accumulation, upregulation of PDGF-B, PDGF-D, and PDGFR-beta, and cellular proliferation were topologically associated and regulated in an AT, receptor-dependent manner in the kidney of angiotensin II-infused rats suggests that these phenomena are related.
  • Minami Abe, Masataka Sata, Etsu Suzuki, Ryo Takeda, Masao Takahashi, Hiroaki Nishimatsu, Daisuke Nagata, Kenji Kangawa, Hisayuki Matsuo, Ryozo Nagai, Yasunobu Hirata
    Clinical science (London, England : 1979) 111 6 381 - 7 2006年12月 [査読有り][通常論文]
     
    Adrenomedullin exerts not only vasodilatory effects, but also angiogenic effects. In the present study, we investigated the effects of adrenomedullin on collateral formation and circulating bone-marrow-derived cells after acute tissue ischaemia. Bone marrow of 8-10-week-old female C57BL/6J mice was replaced with that from GFP (green fluorescent protein) transgenic mice (GFP mice). At 8 weeks after transplantation, hindlimb ischaemia was induced by resecting the right femoral artery and a plasmid expressing human adrenomedullin (50 mug) was injected into the ischaemic muscle, followed by in vivo electroporation on a weekly basis. Overexpression of adrenomedullin significantly enhanced the blood flow recovery compared with controls (blood flow ratio, 1.0+/-0.2 compared with 0.6+/-0.3 respectively, at week 4; P<0.05) and increased capillary density in the ischaemic leg as determined by anti-CD31 immunostaining of the ischaemic muscle (567+/-40 compared with 338+/-65 capillaries/mm(2) respectively, at week 5; P<0.05). There were more GFP-positive cells in the thigh muscle of the mice injected with adrenomedullin than in that of the control mice (29.6+/-4.5 compared with 16.5+/-3.3 capillaries/mm(2) respectively, at week 5; P<0.05). We repeated the same experiments using LacZ-knock-in mice instead of GFP mice, and obtained similar results. These findings suggest that adrenomedullin may augment ischaemia-induced collateral formation with some effects on circulating bone-marrow-derived cells.
  • Sainz Julie, Sata Masataka, Hasegawa Takaaki, Shirakawa Ibuki, Sugawara Yumi, Kato Hiromi, Nagai Ryozo
    CIRCULATION RESEARCH 99 11 1278 - 1279 2006年11月 [査読有り][通常論文]
  • 中澤 誠, 青見 茂之, 梅村 敏, 奥山 虎之, 鎌谷 直之, 小杉 眞司, 斎藤 加代子, 城尾 邦隆, 永井 良三, 平原 史樹, 福嶋 義光, 松岡 瑠美子, 松田 一郎, 松森 昭, 山岸 敬幸, 石上 友章, 今井 靖, 佐地 勉, 西尾 亮介, 田中 敏博, 東倉 洋一, 新川 詔夫, 古山 順一, 堀 正二, 日本循環器学会
    Circulation Journal 70 Suppl.IV 1377 - 1389 (一社)日本循環器学会 2006年11月
  • Kansei Uno, Katsu Takenaka, Kenichi Asada, Aya Ebihara, Kazuno Sasaki, Takako Komuro, Ryozo Nagai, Noboru Motomura, Minoru Ono, Shinichi Takamoto
    Journal of the American Society of Echocardiography : official publication of the American Society of Echocardiography 19 11 1401.e9-1401.e11 - e11 2006年11月 [査読有り][通常論文]
     
    We report two cases of subacute cardiac rupture after myocardial infarction in which contrast echocardiography combined with intermittent pulsing technique was helpful to diagnose small leakage from left ventricle.
  • Takaoka Minoru, Sata Masataka, Nagai Ryozo
    CIRCULATION 114 18 109  2006年10月 [査読有り][通常論文]
  • Tanaka Kimie, Sata Masataka, Hirata Yasunobu, Nagai Ryozo
    CIRCULATION 114 18 23  2006年10月 [査読有り][通常論文]
  • Sahara Makoto, Sata Masataka, Morita Toshihiro, Hirata Yasunobu, Nagai Ryozo
    CIRCULATION 114 18 82  2006年10月 [査読有り][通常論文]
  • Sahara Makoto, Sata Masataka, Morita Toshihiro, Hirata Yasunobu, Nagai Ryozo
    CIRCULATION 114 18 131  2006年10月 [査読有り][通常論文]
  • Fukuda Daiju, Sata Masataka, Nagai Ryozo
    CIRCULATION 114 18 185  2006年10月 [査読有り][通常論文]
  • Sahara Makoto, Sata Masataka, Morita Toshihiro, Hirata Yasunobu, Nagai Ryozo
    CIRCULATION 114 18 192  2006年10月 [査読有り][通常論文]
  • Matsumoto Miwa, Sata Masataka, Soma Masaaki, Nagai Ryozo
    CIRCULATION 114 18 307  2006年10月 [査読有り][通常論文]
  • Fukuda Daiju, Sata Masataka, Nagai Ryozo
    CIRCULATION 114 18 259  2006年10月 [査読有り][通常論文]
  • 小野 稔, 本村 昇, 竹内 功, 山本 哲史, 土肥 善郎, 齋藤 綾, 河田 光弘, 縄田 寛, 益澤 明広, 山内 治雄, 大野 貴之, 吉井 剛, 嶋田 正吾, 師田 哲郎, 村上 新, 高本 眞一, 遠藤 美代子, 絹川 弘一郎, 平田 恭信, 永井 良三
    移植 41 5 522 - 522 (一社)日本移植学会 2006年10月
  • 大動脈基部拡大と潰瘍性大腸炎を合併した大動脈炎症候群の心不全例
    武田 憲文, 高橋 政夫, 小野 祥太郎, 今井 靖, 石坂 信和, 山下 尋史, 平田 恭信, 永井 良三, 師田 哲郎, 高本 眞一
    日本内科学会関東地方会 539回 23 - 23 日本内科学会-関東地方会 2006年10月 [査読有り][通常論文]
  • Shuichi Tsuruoka, Kenta Nishiki, Takashi Ioka, Hitoshi Ando, Yuichiro Saito, Masahiko Kurabayashi, Ryozo Nagai, Akio Fujimura
    Nephrology, dialysis, transplantation : official publication of the European Dialysis and Transplant Association - European Renal Association 21 10 2762 - 7 2006年10月 [査読有り][通常論文]
     
    BACKGROUND: Homozygous Klotho mutant mice (KL(-/-) mice) exhibit multiple phenotypes resembling human ageing. Increases in the ratio of urinary calcium to urinary creatinine (uCa/uCr) and in serum Ca concentration and decreases in urinary Cr excretion and serum parathyroid hormone (PTH) concentration were reported; however, precise information about renal Ca handling was not reported in these animals. METHODS: We evaluated the PTH-induced increase in intracellular Ca(2+) concentration ([Ca(2+)]i) in cells of isolated perfused connecting tubules (CNTs) of KL(-/-) mice. We also determined fractional excretion of Ca from the urine and serum samples of the same animals (n = 7), and compared them with KL(+/+) mice and hemi-nephrectomized KL(-+/+) mice (n = 10 in each) as controls. RESULTS: FECa was significantly higher in KL(-/-) mice than in controls (0.67 +/- 0.13 vs 0.20 +/- 0.04%). The PTH (10 nM)-induced increase in [Ca(2+)]i was diminished in KL(-/-) mice (58 +/- 5 vs 231 +/- 15 nM). Addition of 10 nM of 8-(4-chlorophenylthio)-cyclic adenosine 3',5'-monophosphate had a similar effect. The PTH-induced increase had completely disappeared by the removal of Ca from lumen and bath in both groups of animals. Removal of sodium (Na) from the solution increased [Ca(2+)]i to a similar extent in both groups. Conclusion. We conclude that renal Ca excretion estimated by determining FECa was defective in the KL(-/-) mice. Impairment of Ca absorption from the lumen by stimulation of PTH in CNTs is one of the mechanisms of this defect. Activity of the basolateral Na/Ca exchanger was preserved in this strain. Therefore, the pathway downstream after generation of second messengers following stimulation of PTH (such as the sorting of transporters of Ca absorption) might be impaired by disruption of the Klotho gene.
  • Ryozo Nagai, Tsutomu Yamazaki, Akira Kitabatake, Kazuaki Shimarnoto, Kenjiro Kikuchi, Ken Okumura, Kunio Shirato, Yukio Maruyama, Masahiko Kurabayashi, Kazuyuki Shimada, Hiroaki Matsuoka, Iwao Yamaguchi, Shigeyuki Nishimura, Nobuyuki Komiyama, Issei Komuro, Katsuo Kanmatsuse, Tamio Teramoto, Teruo Takano, Hiroshi Yamaguchi, Satoshi Ogawa, Seibu Mochizuki, Tetsu Yamaguchi, Shin-ichi Momomura, Tsutomu Tamura, Nobuharu Akatsuka, Satoshi Umemura, Tohru Izumi, Uichi Ikeda, Yoshifusa Aizawa, Hiroshi Mabuchi, Noboru Takekoshi, Takayuki Itoh, Haruo Hirayama, Daini Red, Takahiko Suzuki, Hisayoshi Fujiwara, Takeshi Nakano, Shigetake Sasayama, Masatoshi Fujita, Hiroshi Kamihata, Masatsugu Hori, Hirofumi Kambara, Ichirci Nishio, Mitsuhiro Yokoyania, Chiaki Shigemasa, Tohru Ohe, Kazuaki Mitsudo, Masunori Matsuzaki, Jitsuo Higaki, Kenji Sunagawa, Tsutoinu Imaizumi, Katsusuke Yano, Hisao Ogawa, Chuwa Tei
    CIRCULATION JOURNAL 70 10 1256 - 1262 2006年10月 [査読有り][通常論文]
     
    Background Although the morbidity and mortality of coronary artery disease (CAD) vary widely with race and lifestyle, Japanese CAD patients have been clinically managed according to the guidelines of Western countries. To draft guidelines specifically for Japanese CAD patients, a database that describes how Japanese CAD patients are currently managed and the outcomes of those managements practices is required. Methods and Results Patients diagnosed as having 75% or higher stenosis according to the American Heart Association classification in at least 1 branch of the coronary arteries by cardiac catheterization were enrolled in the study. Of 15,628 patients screened from April 2000 to March 2001, 13,812 of them met the inclusion criteria and were followed up for a mean period of 2.7 years. The incident rate of events was 62.8 per 1,000 patients-year including all-cause mortality of 17.5 and total cardiac events of 47.4 per 1,000 patients-year which is much higher than previous reports in Japan. The incident rate of acute myocardial infarction in this study cohort was 7.5 events per 1,000 patients-year. Conclusion The database provides a large body of information on Japanese CAD patients who have significant coronary atherosclerosis diagnosed by coronary angiography, which will be useful for planning future randomized controlled trials.
  • Hiroshi Doi, Tatsuya Iso, Hiroko Sato, Miki Yamazaki, Hiroki Matsui, Toru Tanaka, Ichiro Manabe, Masashi Arai, Ryozo Nagai, Masahiko Kurabayashi
    The Journal of biological chemistry 281 39 28555 - 64 2006年09月 [査読有り][通常論文]
     
    The Notch signaling pathway plays a crucial role in specifying cellular fates by interaction between cellular neighbors; however, the molecular mechanism underlying smooth muscle cell (SMC) differentiation by Notch signaling has not been well characterized. Here we demonstrate that Jagged1-Notch signaling promotes SMC differentiation from mesenchymal cells. Overexpression of the Notch intracellular domain, an activated form of Notch, up-regulates the expression of multiple SMC marker genes including SMC-myosin heavy chain (Sm-mhc) in mesenchymal 10T1/2 cells, but not in non-mesenchymal cells. Physiological Notch stimulation by its ligand Jagged1, but not Dll4, directly induces Sm-mhc expression in 10T1/2 cells without de novo protein synthesis, indicative of a ligand-selective effect. Jagged1-induced expression of SM-MHC was blocked bygamma-secretase inhibitor, N-(N-(3,5-difluorophenyl)-l-alanyl)-S-phenylglycine t-butyl ester, which impedes Notch signaling. Using Rbp-jkappa-deficient cells and site-specific mutagenesis of the SM-MHC gene, we show that such an induction is independent of the myocardin-serum response factor-CArG complex, but absolutely dependent on RBP-Jkappa, a major mediator of Notch signaling, and its cognate binding sequence. Of importance, Notch signaling and myocardin synergistically activate SM-MHC gene expression. Taken together, these data suggest that the Jagged1-Notch pathway constitutes an instructive signal for SMC differentiation through an RBP-Jkappa-dependent mechanism and augments gene expression mediated by the myocardin-SRF-CArG complex. Given that Notch pathway components are expressed in vascular SMC during normal development and disease, Notch signaling is likely to play a pivotal role in such situations to modulate the vascular smooth muscle cell phenotype.
  • Nozomu Kamei, Kazuyuki Tobe, Ryo Suzuki, Mitsuru Ohsugi, Taku Watanabe, Naoto Kubota, Norie Ohtsuka-Kowatari, Katsuyoshi Kumagai, Kentaro Sakamoto, Masatoshi Kobayashi, Toshimasa Yamauchi, Kohjiro Ueki, Yumiko Oishi, Satoshi Nishimura, Ichiro Manabe, Haruo Hashimoto, Yasuyuki Ohnishi, Hitomi Ogata, Kumpei Tokuyama, Masaki Tsunoda, Tomohiro Ide, Koji Murakami, Ryozo Nagai, Takashi Kadowaki
    The Journal of biological chemistry 281 36 26602 - 14 2006年09月 [査読有り][通常論文]
     
    Adipose tissue expression and circulating concentrations of monocyte chemoattractant protein-1 (MCP-1) correlate positively with adiposity. To ascertain the roles of MCP-1 overexpression in adipose, we generated transgenic mice by utilizing the adipocyte P2 (aP2) promoter (aP2-MCP-1 mice). These mice had higher plasma MCP-1 concentrations and increased macrophage accumulation in adipose tissues, as confirmed by immunochemical, flow cytometric, and gene expression analyses. Tumor necrosis factor-alpha and interleukin-6 mRNA levels in white adipose tissue and plasma non-esterified fatty acid levels were increased in transgenic mice. aP2-MCP-1 mice showed insulin resistance, suggesting that inflammatory changes in adipose tissues may be involved in the development of insulin resistance. Insulin resistance in aP2-MCP-1 mice was confirmed by hyperinsulinemic euglycemic clamp studies showing that transgenic mice had lower rates of glucose disappearance and higher endogenous glucose production than wild-type mice. Consistent with this, insulin-induced phosphorylations of Akt were significantly decreased in both skeletal muscles and livers of aP2-MCP-1 mice. MCP-1 pretreatment of isolated skeletal muscle blunted insulin-stimulated glucose uptake, which was partially restored by treatment with the MEK inhibitor U0126, suggesting that circulating MCP-1 may contribute to insulin resistance in aP2-MCP-1 mice. We concluded that both paracrine and endocrine effects of MCP-1 may contribute to the development of insulin resistance in aP2-MCP-1 mice.
  • Shin-ichi Usui, Atsushi Yao, Masaru Hatano, Osami Kohmoto, Toshiyuki Takahashi, Ryozo Nagai, Kichiro Kinugawa
    CIRCULATION JOURNAL 70 9 1208 - 1215 2006年09月 [査読有り][通常論文]
     
    Background Left ventricular remodeling might be involved in the pathophysiology of right ventricular hypertrophy/failure due to pulmonary arterial hypertension (PAH), while the left ventricle is considered not under pressure/volume overload. Methods and Results Rats with monocrotaline-induced PAH were used in the present study to examine whether upregulated neurohumoral factors may induce left ventricular (LV) remodeling and (/or) contribute to prognosis. Morphological analysis revealed a significant increase in the weight of the free walls of both ventricles and the interventricular septum, indicating biventricular hypertrophy, although systemic blood pressure was not elevated. RNase protection assay demonstrated the activation of a fetal gene program in the cardiac muscle of the left and right ventricular free walls. Similar activation of the fetal gene program was observed in the LV of rats continuously infused with angiotensin (AT) It, although this was not the case for rats infused with isoproterenol. Measured plasma levels of ATII, noradrenaline, and brain natriuretic peptide (BNP) were all significantly elevated in the PAH rats. Furthermore, the plasma BNP level positively correlated with the ratio of heart weight to body weight and the plasma level of ATII. Not right but LV hypertrophy was significantly reduced by treatment with an AT H type I receptor blocker, valsartan, whereas the effect of an adrenergic alpha(1) and beta(1,2) blocker, carvedilol, was borderline. Survival rate in the PAH rats was significantly improved when they were treated with valsartan or carvedilol. Conclusions Upregulated neurohumoral factors seem to play an important role in LV remodeling without mechanical overload, and are associated with impairment of prognosis in rats with PAH.
  • Nobukazu Ishizaka, Yuko Ishizaka, Hideki Hashimoto, Ei-Ichi Toda, Ryozo Nagai, Minoru Yamakado
    HYPERTENSION 48 3 411 - 417 2006年09月 [査読有り][通常論文]
     
    Much evidence indicates that metabolic syndrome is a risk factor for the development of cardiovascular disease, but whether metabolic syndrome is an independent risk factor for early atherosclerosis in the individuals with only minor hemodynamic abnormalities, if any, is not well investigated. Here we have investigated the association between metabolic syndrome and carotid atherosclerosis in individuals with blood pressure of < 140/90 mm Hg. Between 1994 and 2003, 8143 subjects underwent general health screening including carotid ultrasonography. Of 8143 individuals, 5661 individuals without antihypertensive medications who had blood pressure of < 140/90 mm Hg were considered to have optimal, normal, or high-normal blood pressure. After adjustment for age, systolic blood pressure, body mass index, total and high-density lipoprotein cholesterol, triglycerides, fasting glucose, and smoking status, metabolic syndrome was not found to be an independent risk factor for carotid plaque (odds ratio: 1.65; 95% CI; 0.72 to 3.76 in women and odds ratio: 0.95; 95% CI: 0.70 to 1.28 in men) or for carotid intima-media thickening (odds ratio: 0.56; 95% CI: 0.18 to 1.72 in women and odds ratio: 0.93 95% CI: 0.62 to 1.38 in men) in these subjects. Thus, presence of metabolic syndrome may not increase the prevalence of carotid atherosclerosis independent of other cardiovascular risk factors in Japanese individuals with optimal, normal, or high-normal blood pressure.
  • Hiroaki Okazaki, Fumiko Tazoe, Sachiko Okazaki, Naoyuki Isoo, Kazuhisa Tsukamoto, Motohiro Sekiya, Naoya Yahagi, Yoko Iizuka, Ken Ohashi, Tetsuya Kitamine, Ryu-Ichi Tozawa, Toshihiro Inaba, Hiroaki Yagyu, Mitsuyo Okazaki, Hitoshi Shimano, Norihito Shibata, Hiroyuki Arai, Ryo-Zo Nagai, Takashi Kadowaki, Jun-Ichi Osuga, Shun Ishibashi
    Journal of lipid research 47 9 1950 - 8 2006年09月 [査読有り][通常論文]
     
    Squalene synthase (SS) is the first committed enzyme for cholesterol biosynthesis, located at a branch point in the mevalonate pathway. To examine the role of SS in the overall cholesterol metabolism, we transiently overexpressed mouse SS in the livers of mice using adenovirus-mediated gene transfer. Overexpression of SS increased de novo cholesterol biosynthesis with increased 3-hydroxy-3-methyglutaryl-CoA (HMG-CoA) reductase activity, in spite of the downregulation of its own mRNA expression. Furthermore, overexpression of SS increased plasma concentrations of LDL, irrespective of the presence of functional LDL receptor (LDLR). Thus, the hypercholesterolemia is primarily caused by increased hepatic production of cholesterol-rich VLDL, as demonstrated by the increases in plasma cholesterol levels after intravenous injection of Triton WR1339. mRNA expression of LDLR was decreased, suggesting that defective LDL clearance contributed to the development of hypercholesterolemia. Curiously, the liver was enlarged, with a larger number of Ki-67-positive cells. These results demonstrate that transient upregulation of SS stimulates cholesterol biosynthesis as well as lipoprotein production, providing the first in vivo evidence that SS plays a regulatory role in cholesterol metabolism through modulation of HMG-CoA reductase activity and cholesterol biosynthesis.
  • Yuichiro Saito, Masahiko Kurabayashi, Tetsuya Nakamura, Ryozo Nagai
    Nihon rinsho. Japanese journal of clinical medicine 64 Suppl 5 403 - 6 2006年07月 [査読有り][通常論文]
  • Aiko Sakamoto, Koji Okamoto, Nobukazu Ishizaka, Kazuaki Tejima, Yasunobu Hirata, Ryozo Nagai
    International heart journal 47 4 645 - 50 2006年07月 [査読有り][通常論文]
     
    A patient with recurrent abdominal pain was admitted to our hospital. Computed tomography showed a soft dense mass surrounding the abdominal aorta at the infrarenal level, which was compatible with retroperitoneal fibrosis. (18)F-fluorodeoxyglucose ((18)F-FDG) positron emission tomography showed abnormal uptake of (18)F-FDG into these lesions. Two months after the initiation of corticosteroid therapy, the abnormal uptake of (18)F-FDG had ceased along with a reduction in the fibrous mass surrounding the abdominal aorta.
  • Hiroaki Okazaki, Masaki Igarashi, Makiko Nishi, Makiko Tajima, Motohiro Sekiya, Sachiko Okazaki, Naoya Yahagi, Ken Ohashi, Kazuhisa Tsukamoto, Michiyo Amemiya-Kudo, Takashi Matsuzaka, Hitoshi Shimano, Nobuhiro Yamada, Junken Aoki, Rei Morikawa, Yasukazu Takanezawa, Hiroyuki Arai, Ryozo Nagai, Takashi Kadowaki, Jun-Ichi Osuga, Shun Ishibashi
    Diabetes 55 7 2091 - 7 2006年07月 [査読有り][通常論文]
     
    Molecular mechanisms underlying lipolysis, as defined by mobilization of fatty acids from adipose tissue, are not fully understood. A database search for enzymes with alpha/beta hydrolase folds, the GXSXG motif for serine esterase and the His-Gly dipeptide motif, has provided a previously unannotated gene that is induced during 3T3-L1 adipocytic differentiation. Because of its remarkable structural resemblance to triacylglycerol hydrolase (TGH) with 70.4% identity, we have tentatively designated this enzyme as TGH-2 and the original TGH as TGH-1. TGH-2 is also similar to TGH-1 in terms of tissue distribution, subcellular localization, substrate specificity, and regulation. Both enzymes are predominantly expressed in liver, adipose tissue, and kidney. In adipocytes, they are localized in microsome and fatcake. Both enzymes hydrolyzed p-nitophenyl butyrate, triolein, and monoolein but not diolein, cholesteryl oleate, or phospholipids; hydrolysis of short-chain fatty acid ester was 30,000-fold more efficient than that of long-chain fatty acid triacylglycerol. Fasting increased the expression of both genes in white adipose tissue, whereas refeeding suppressed their expression. RNA silencing of TGH-2 reduced isoproterenol-stimulated glycerol release by 10% in 3T3-L1 adipocytes, while its overexpression increased the glycerol release by 20%. Thus, TGH-2 may make a contribution to adipocyte lipolysis during period of increased energy demand.
  • Go Nishimura, Ichiro Manabe, Kensuke Tsushima, Katsuhito Fujiu, Yumiko Oishi, Yasushi Imai, Koji Maemura, Makoto Miyagishi, Yujiro Higashi, Hisato Kondoh, Ryozo Nagai
    Developmental cell 11 1 93 - 104 2006年07月 [査読有り][通常論文]
     
    Alteration in the differentiated state of smooth muscle cells (SMCs) is known to be integral to vascular development and the pathogenesis of vascular disease. However, it is still largely unknown how environmental cues translate into transcriptional control of SMC genes. We found that deltaEF1 is upregulated during SMC differentiation and selectively transactivates the promoters of SMC differentiation marker genes, SM alpha-actin and SM myosin heavy chain (SM-MHC). DeltaEF1 physically interacts with SRF and Smad3, resulting in a synergistic activation of SM alpha-actin promoter. Chromatin immunoprecipitation assays and knockdown experiments showed that deltaEF1 is involved in the control of the SMC differentiation programs induced by TGF-beta signaling. Overexpression of deltaEF1 inhibited neointima formation and promoted SMC differentiation, whereas heterozygous deltaEF1 knockout mice exhibited exaggerated neointima formation. It thus appears deltaEF1 mediates SMC differentiation via interaction with SRF and Smad3 during development and in vascular disease.
  • Kazuo Hara, Momoko Horikoshi, Toshimasa Yamauchi, Hirokazu Yago, Osamu Miyazaki, Hiroyuki Ebinuma, Yasushi Imai, Ryozo Nagai, Takashi Kadowaki
    Diabetes care 29 6 1357 - 62 2006年06月 [査読有り][通常論文]
     
    OBJECTIVE: The high-molecular weight (HMW) form of adiponectin, an adipocyte-derived insulin-sensitizing hormone, has been reported to be the most active form of this hormone. We investigated whether measurement of plasma HMW adiponectin levels, using our newly developed enzyme-linked immunosorbent assay system for selective measurement of human HMW adiponectin level, may be useful for the prediction of insulin resistance and metabolic syndrome. RESEARCH DESIGN AND METHODS: A total of 298 patients admitted for diabetes treatment or coronary angiography served as study subjects. Receiver operator characteristic (ROC) curves for the HMW ratio (HMWR; ratio of plasma level of HMW adiponectin to that of total adiponectin) and plasma total adiponectin levels were plotted to predict the presence of insulin resistance and metabolic syndrome. RESULTS: The area under the ROC curve (AUC) of the HMWR values to predict the presence of insulin resistance was significantly larger than that of plasma total adiponectin level in total subjects (0.713 [95% CI 0.620-0.805] vs. 0.615 [0.522-0.708], P = 0.0160). The AUC for the HMWR values to predict the presence of metabolic syndrome was significantly larger than that for plasma total adiponectin levels in men (0.806 [0.747-0.865] vs. 0.730 [0.660-0.800], P = 0.0025) and in women (0.743 [0.659-0.828] vs. 0.637 [0.532-0.742], P = 0.0458). CONCLUSIONS: The HMWR value has better predictive power for the prediction of insulin resistance and metabolic syndrome than plasma total adiponectin level.
  • S Nishimura, S Nagai, M Sata, M Katoh, H Yamashita, Y Saeki, R Nagai, S Sugiura
    MOLECULAR AND CELLULAR BIOCHEMISTRY 286 1-2 59 - 65 2006年06月 [査読有り][通常論文]
     
    Green fluorescent protein (GFP) is widely used as a biologically inert expression marker for studying the effects of transgene expression in heart tissue, but its influence on the contractile function of cardiomyocytes has not yet been fully evaluated. We measured the contractile function of isolated rat ventricular myocytes before and after infection with a recombinant adenovirus expressing GFP (Adv-GFP). Myocytes infected with a non-transgene-containing adenovirus (Adv-Null) or uninfected myocytes (UI) served as controls. Using a carbon-fiber-based force-length measurement system for single cardiomyocytes, we evaluated the contractile function over a wide range of loading conditions including the shortening fraction (%FS) and maximal shortening velocity (Vmax) under the unloaded condition, and isometric force. At 24 hours after infection, nearly 80% of the Adv-GFP-infected myocytes expressed GFR We found that the %FS and Vmax did not differ among the three groups, however, the isometric force showed a mild, but significant, decrease only in Adv-GFP myocytes (Adv-GFP: 29.1 +/- 4.0 mN/mm(2); Adv-Null: 42.8 +/- 6.2 mN/mm(2); UI: 47.1 +/- 4.8 mN/mm(2); p = 0.03). An evaluation of the contractile function of isolated cardiomyocytes under high load conditions revealed impaired isometric contractility by GFP expression. Adv-GFP expression may not be an ideal control for specific gene expression experiments in myocardial tissue.
  • Yuichiro Saito, Masahiko Kurabayashi, Tetsuya Nakamura, Ryozo Nagai
    Nihon Ronen Igakkai zasshi. Japanese journal of geriatrics 43 3 342 - 4 2006年05月 [査読有り][通常論文]
     
    The klotho gene, originally identified by insertional mutagenesis in mice, suppresses multiple aging phenotypes (e.g. arteriosclerosis, pulmonary emphysema, osteoporosis, infertility, skin atrophy). We have demonstrated that mice deficient for the klotho gene show endothelial dysfunction as manifested by an attenuated response of aortic relaxation in response to acetylcholine stimulation. Systemic nitric oxide production was also significantly reduced in klotho deficient mice. Oxidative stress was increased in klotho deficient mice. The klotho gene delivery improves multiple aging phenotypes. Our findings establish the basis for the therapeutic potential of klotho gene delivery in age-related diseases.
  • Takayoshi Matsumura, Akihiro Matsumoto, Minoru Ohno, Shinya Suzuki, Miki Ohta, Etsu Suzuki, Katsu Takenaka, Yasunobu Hirata, Toshiro Fujita, Ryozo Nagai
    The American journal of the medical sciences 331 5 280 - 3 2006年05月 [査読有り][通常論文]
     
    Although cholesterol embolism syndrome was recognized as a clinicopathologic entity more than 50 years ago, it is attracting growing attention recently. It is a multisystemic disorder in which cholesterol crystals released from atherosclerotic plaques obstruct small arterioles, resulting in local ischemia and end-organ damage. There are no established treatments, and with the limited treatment options available, it is important to make the diagnosis as early as possible. We present the case of a 68-year-old man with cholesterol embolism who had a few fluttering atheromas in the aorta, as demonstrated by transesophageal ultrasonography. The diagnosis was confirmed by skin biopsy, and treatment with statins and steroids proved effective, as renal failure progressively improved. This case emphasizes the importance of early diagnosis and shows the possible therapeutic effects of statins and steroids for patients with this syndrome.
  • Kazuo Hara, Momoko Horikoshi, Hiroji Kitazato, Chikako Ito, Mitsuhiko Noda, Jun Ohashi, Philippe Froguel, Katsushi Tokunaga, Kazuyuki Tobe, Ryozo Nagai, Takashi Kadowaki
    Diabetes 55 5 1260 - 4 2006年05月 [査読有り][通常論文]
     
    Hepatocyte nuclear factor (HNF)-4alpha is a transcription factor known as a key molecule in the development and functions of the beta-cells. In a previously performed genome-wide scan of Japanese type 2 diabetic sibpairs, we observed linkage of type 2 diabetes to chromosome 20q12-q13, a region in which the HNF4A gene is located. Recent studies have reported associations between type 2 diabetes and polymorphisms in the P2 promoter region specific to beta-cells. In this study, we attempted to assess whether the HNF4A gene plays a role in the genetic susceptibility to type 2 diabetes in the Japanese population by analyzing polymorphisms and haplotypes of the HNF4A gene. Linkage disequilibrium across the P2 promoter region was preserved in the Japanese population, consistent with previous reports. Although none of the individual polymorphisms examined showed any significant association with type 2 diabetes, we found very strong evidence of the association between type 2 diabetes and the haplotype consisting of two polymorphisms in the P2 promoter region of the HNF4A gene (P = 3.82 x 10(-4)). In contrast, there was no association between type 2 diabetes and haplotypes consisting of polymorphisms not located in the P2 promoter region, suggesting that the type 2 diabetes susceptibility loci are localized in the P2 promoter region of the HNF4A gene. The association was replicated using two additional cohorts (P = 1.51 x 10(-4) and 0.019, respectively). The results of the present analysis revealed that the HNF4A gene might be a type 2 diabetes susceptibility gene common to different ethnic groups. The study also suggested the possible existence of an as-yet-unidentified but functional polymorphism in the P2 promoter region of the HNF4A gene that directly influences susceptibility to type 2 diabetes.
  • Norifumi Takeda, Ichiro Manabe, Takayuki Shindo, Hiroshi Iwata, Satoshi Iimuro, Hiroyuki Kagechika, Koichi Shudo, Ryozo Nagai
    Arteriosclerosis, thrombosis, and vascular biology 26 5 1177 - 83 2006年05月 [査読有り][通常論文]
     
    BACKGROUND: Macrophage scavenger receptors facilitate the uptake of modified low-density lipoprotein (LDL), formation of foam cells, and development of atherosclerosis. Given that proinflammatory cytokines, including IL-6, can modulate the macrophage foaming process, the aim of the present study was to determine whether the synthetic retinoic acid receptor-alpha/beta-specific agonist Am80, which is also an IL-6 inhibitor, can modulate macrophage lipid accumulation and foam cell formation. METHODS AND RESULTS: Am80 suppressed IL-6 production induced by 12-myristate 13-acetate (PMA) or angiotensin II in mouse Raw264 macrophages. It also suppressed expression of the 2 major scavenger receptors (scavenger receptor-A [SR-A] and CD36), in part by inhibiting IL-6, and inhibited macrophage foam cell formation. Systemic administration of Am80 led to reductions in the areas of atherosclerotic lesions and foam cell accumulation in the aortas of apolipoprotein E (apoE)-deficient mice and reduced serum concentrations of IL-6 and IL-1beta without affecting body weights, serum lipid profiles or IL-10 levels. CONCLUSIONS: Am80 suppresses scavenger receptor expression and macrophage foam cell formation in vitro and prevents atherogenesis in apoE-deficient mice in vivo. This suggests Am80 is a novel candidate agent that could be highly useful in the prevention and treatment of atherosclerosis.
  • Momoko Horikoshi, Kazuo Hara, Jun Ohashi, Kazuaki Miyake, Katsushi Tokunaga, Chikako Ito, Masato Kasuga, Ryozo Nagai, Takashi Kadowaki
    Diabetes 55 4 919 - 23 2006年04月 [査読有り][通常論文]
     
    AMP-activated protein kinase (AMPK) acts as a fuel gauge for glucose and lipid metabolism. The gene encoding the alpha2 isoform of the catalytic subunit of AMPK (PRKAA2) is located at one of the Japanese type 2 diabetes loci mapped by our previous genome scan (1p36-32). PRKAA2 is, therefore, a good candidate gene for insulin resistance and type 2 diabetes. We screened all nine exons, their exon-intron boundaries, and the 5' and 3' flanking regions of PRKAA2 to identify single nucleotide polymorphisms (SNPs), and we genotyped 192 type 2 diabetic patients and 272 nondiabetic subjects to assess possible associations between genotypes or haplotypes and type 2 diabetes. None of the 10 SNPs genotyped was associated with type 2 diabetes, but the haplotype analysis, consisting of six representative SNPs, revealed one haplotype, with the A (minor) allele for rs2051040 and a major allele for the other five SNPs, to be associated with type 2 diabetes (P = 0.009). This finding was confirmed in two larger replication samples (657 case and 360 control subjects, P = 0.021; and 356 case and 192 control subjects from the same area in Japan, P = 0.007) and a significant P value was obtained in the joint haplotype analysis of all samples (1,205 case and 824 control subjects, P = 0.0001). Furthermore, insulin resistance was associated with rs2051040 in nondiabetic subjects, and those with the A (minor) allele had a higher homeostasis model assessment of insulin resistance index than those who did not (initial control subjects [n = 272], P = 0.002; and joint replication control subjects [n = 552], P = 0.037). We speculate that the PRKAA2 gene influences insulin resistance and susceptibility to type 2 diabetes in the Japanese population.
  • Naoto Kubota, Yasuo Terauchi, Tetsuya Kubota, Hiroki Kumagai, Shinsuke Itoh, Hidemi Satoh, Wataru Yano, Hitomi Ogata, Kumpei Tokuyama, Iseki Takamoto, Tomoka Mineyama, Michiro Ishikawa, Masao Moroi, Kaoru Sugi, Toshimasa Yamauchi, Kohjiro Ueki, Kazuyuki Tobe, Tetsuo Noda, Ryozo Nagai, Takashi Kadowaki
    The Journal of biological chemistry 281 13 8748 - 55 2006年03月 [査読有り][通常論文]
     
    Thiazolidinediones have been shown to up-regulate adiponectin expression in white adipose tissue and plasma adiponectin levels, and these up-regulations have been proposed to be a major mechanism of the thiazolidinedione-induced amelioration of insulin resistance linked to obesity. To test this hypothesis, we generated adiponectin knock-out (adipo-/-) ob/ob mice with a C57B/6 background. After 14 days of 10 mg/kg pioglitazone, the insulin resistance and diabetes of ob/ob mice were significantly improved in association with significant up-regulation of serum adiponectin levels. Amelioration of insulin resistance in ob/ob mice was attributed to decreased glucose production and increased AMP-activated protein kinase in the liver but not to increased glucose uptake in skeletal muscle. In contrast, insulin resistance and diabetes were not improved in adipo-/-ob/ob mice. After 14 days of 30 mg/kg pioglitazone, insulin resistance and diabetes of ob/ob mice were again significantly ameliorated, which was attributed not only to decreased glucose production in the liver but also to increased glucose uptake in skeletal muscle. Interestingly, adipo-/-ob/ob mice also displayed significant amelioration of insulin resistance and diabetes, which was attributed to increased glucose uptake in skeletal muscle but not to decreased glucose production in the liver. The serum-free fatty acid and triglyceride levels as well as adipocyte sizes in ob/ob and adipo-/-ob/ob mice were unchanged after 10 mg/kg pioglitazone but were significantly reduced to a similar degree after 30 mg/kg pioglitazone. Moreover, the expressions of TNFalpha and resistin in adipose tissues of ob/ob and adipo-/-ob/ob mice were unchanged after 10 mg/kg pioglitazone but were decreased after 30 mg/kg pioglitazone. Thus, pioglitazone-induced amelioration of insulin resistance and diabetes may occur adiponectin dependently in the liver and adiponectin independently in skeletal muscle.
  • Wrapped Liposome siRNAのマウス脈絡膜新生血管モデルにおける動態検討
    高橋 秀徳, 小畑 亮, 柳 靖雄, 玉置 泰裕, 真鍋 一郎, 八木 信宏, 山内 雅博, 永井 良三
    日本眼科学会雑誌 110 臨増 275 - 275 (公財)日本眼科学会 2006年03月
  • Imai Yasushi, Hayashi Dobun, Manabe Ichiro, Harada Tomohiro, Takeda Norihiko, Monzen Koshiro, Kohro Takahide, Yamazaki Tadashi, Maemura Koji, Sugiyama Takao, Yamazaki Tsutomu, Nagai Ryozo
    Circulation Journal 70 Suppl.I 609 - 609 2006年03月
  • T Yamazaki, J Suzuki, R Shimamoto, T Tsuji, Y Ohmoto, T Toyo-Oka, M Omata, K Ohtomo, R Nagai
    INTERNATIONAL HEART JOURNAL 47 2 247 - 258 2006年03月 [査読有り][通常論文]
     
    In hypertrophic cardiomyopathy (HCM) a hyperkinetic state is sometimes observed in spite of impaired systolic function in the hypertrophied myocardium. The aim of the present study was to determine the mechanism of this paradox. Seventeen patients with HCM and 10 normal subjects underwent cine magnetic resonance (MR) imaging to measure percent systolic wall thickening and percent fractional shortening. The ratio of systolic radial wall stress of the LV at the hyperthrophied myocardium over that at the nonhypertrophied myocardium was evaluated to describe the focal advantageous condition for wall thickening. The ratio was 0.66 +/- 0.36 at the start of contraction and 0.78 +/- 0.31 at early-systole, indicating consistently smaller radial wall stress at the hypertrophied myocardium. Althought the condition for contraction was favorable (a ratio less than 1.00), perecent systolic wall thickening at the hypertrophied myocardium (23.0 +/- 11.8%) was smaller than that at the nonhypertrophied myocardium (70.5 +/- 32.3%). Smaller end-diastolic dimension (HCM group; 45.2 +/- 4.2 mm, reference group; 48.9 +/- 4.1 mm, P = 0.04) with a statistically identical value of systolic decrease in intraventricular dimension (HCM group; 19.7 +/- 3.9 mm, reference group; 18.9 +/- 3.2 mm, P = 0.60) yielded high percent fractional shortening in patients with HCM (43.5 +/- 7.6%). Although contractile impairment was proven at the hypertrophied region with low radial wall stress in the HCM group, the smaller end-diastolic dimension in this group resulted in high percent fractional shortening.
  • Daiji Kawanami, Koji Maemura, Norihiko Takeda, Tomohiro Harada, Takefumi Nojiri, Tetsuya Saito, Ichiro Manabe, Yasushi Imai, Ryozo Nagai
    Atherosclerosis 185 1 39 - 46 2006年03月 [査読有り][通常論文]
     
    Recent studies have shown that C-reactive protein (CRP) is not just a predictor of cardiovascular events but also acts directly as a proinflammatory stimulus in vascular cells. In this report, we studied the molecular mechanisms underlying vascular cellular adhesion molecule-1 (VCAM-1) induction by CRP. CRP-induced VCAM-1 mRNA expression and this induction was inhibited by protein kinase C (PKC) inhibitors, p38 mitogen-activated protein kinase (MAPK) inhibitor, and tyrosine kinase inhibitors. In addition, parthenolide, a nuclear factor kappaB (NF-kappaB) inhibitor, abolished VCAM-1 induction. Moreover, CRP increased VCAM-1 promoter activity, indicating that CRP induces VCAM-1 mRNA expression at the transcriptional level. Mutation of NF-kappaB-binding sites resulted in a loss of induction. Finally, an electrophoretic mobility shift assay confirmed binding of the p65 subunit of NF-kappaB to kappaB-binding sites. Taken together, our findings suggest that VCAM-1 induction by CRP is mediated by PKC, p38MAPK, tyrosine kinase and the NF-kappaB-dependent signaling pathways in vascular endothelial cells.
  • Ji Ma, Shinya Kishida, Guo Qin Wang, Kentarou Meguro, Hiroyuki Imuta, Hitoshi Oonuma, Haruko Iida, Taisuke Jo, Haruhito Takano, Toshihiro Morita, Ryozo Nagai, Toshiaki Nakajima
    Journal of cardiovascular pharmacology 47 2 314 - 21 2006年02月 [査読有り][通常論文]
     
    Overproduction of nitric oxide by inducible nitric oxide synthase contributes to the progression of cardiovascular disease. We investigated the effects of azelnidipine and other Ca2+-channel blockers on nitric oxide production by cultured aortic smooth muscle cells isolated from Wistar rats and human umbilical vein endothelial cells (HUVECs), using the Griess reaction and oxyhemoglobin method. Release of lactic dehydrogenase (LDH) was measured to evaluate cell damage, and immunohistochemistry was performed to examine the expression of inducible nitric oxide synthase and nitrotyrosine protein. Azelnidipine and other Ca2+-channel blockers inhibited the release of nitric oxide induced by lipopolysaccharide plus interferon-gamma. Azelnidipine inhibited it most potently among the Ca2+-channel blockers tested (azelnidipine, amlodipine, nifedipine, diltiazem, verapamil, and nicardipine) at a concentration of 10 microM. Longer stimulation with these agents induced the expression of inducible nitric oxide synthase and nitrotyrosine, with an increase of lactic dehydrogenase release, whereas azelnidipine suppressed these changes. In human umbilical vein endothelial cells, azelnidipine enhanced basal nitric oxide production by endothelial nitric oxide synthase. In conclusion, azelnidipine potently inhibited the induction of inducible nitric oxide synthase and then nitric oxide production in vascular smooth muscle cells, while enhancing constitutive nitric oxide production by endothelial cells. Azelnidipine may inhibit nitrotyrosine expression and cell damage caused by overproduction of nitric oxide, suggesting a mechanism for its cardiovascular protective effect.
  • Satoshi Nishimura, Shinya Nagai, Masayoshi Katoh, Hiroshi Yamashita, Yasutake Saeki, Jun-Ichi Okada, Toshiaki Hisada, Ryozo Nagai, Seiryo Sugiura
    Circulation Research 98 1 81 - 87 2006年01月 [査読有り][通常論文]
     
    Although microtubules are involved in various pathological conditions of the heart including hypertrophy and congestive heart failure, the mechanical role of microtubules in cardiomyocytes under such conditions is not well understood. In the present study, we measured multiple aspects of the mechanical properties of single cardiomyocytes, including tensile stiffness, transverse (indentation) stiffness, and shear stiffness in both transverse and longitudinal planes using carbon fiber-based systems and compared these parameters under control, microtubule depolymerized (colchicine treated), and microtubule hyperpolymerized (paclitaxel treated) conditions. From all of these measurements, we found that only the stiffness against shear in the longitudinal plane was modulated by the microtubule cytoskeleton. A simulation model of the myocyte in which microtubules serve as compression-resistant elements successfully reproduced the experimental results. In the complex strain field that living myocytes experience in the body, observed changes in shear stiffness may have a significant influence on the diastolic property of the diseased heart. © 2006 American Heart Association, Inc.
  • Shinya Kishida, Toshiaki Nakajima, Ji Ma, Taisuke Jo, Hiroyuki Imuta, Hitoshi Oonuma, Haruko Iida, Haruhito Takano, Toshihiro Morita, Ryozo Nagai
    International heart journal 47 1 85 - 93 2006年01月 [査読有り][通常論文]
     
    Amiodarone (AM) is a potent vasodilator and exhibits diverse cardiovascular protective effects in vivo, but their underlying mechanisms remain unsettled. We investigated the effects of AM and N-desethylamiodarone (DEA), the major metabolite of AM, on endothelial nitric oxide (NO) production using cultured human umbilical vein endothelial cells (HUVECs). The release of NO was evaluated as measured by nitrite, a stable metabolite of NO, using the Griess reaction and also measured directly by a NO-selective electrode. The expression of each nitric oxide synthase (NOS) mRNA was examined by reverse transcriptase-polymerase chain reaction (RT-PCR), and the effects of AM on eNOS mRNA expression were studied by quantitative real-time RT-PCR. AM and DEA (1-30 microM) enhanced NO production in a concentration-dependent manner. DEA was capable of producing more NO than AM. L-NAME, a nonselective NOS inhibitor, EGTA, a Ca(2+)-chelating agent, and nickel, a nonspecific Ca(2+) blocker, all inhibited AM-induced NO production. However, LY294002, an Akt pathway inhibitor and SB202190, a MAP kinase inhibitor, did not significantly suppress the production. In RT-PCR analysis, only eNOS mRNA was detected. Treatment with AM for 4 hours did not show a significant increase in the expression of eNOS mRNA. AM lower than 30 microM did not induce apoptosis, net cell loss, or LDH release from cells. The present study provides the first evidence that therapeutic concentrations of AM and DEA enhance eNOS-mediated NO production without any toxic or apoptotic effects. This mechanism may underlie the cardiovascular protective effects of AM and its metabolite observed in a clinical setting.
  • Takanobu Tomaru, Takefumi Matuo, Nanami Kario, Teruhiko Aoyagi, Testu Ohnishi, Tetsuya Sumiyoshi, Toshiyuki Degawa, Makoto Akashi, Fumitaka Nakamura, Ryozo Nagai
    Advances in Heart Disease 365 - 368 2006年 [査読有り][通常論文]
  • Makoto Sahara, Toshiyuki Takahashi, Toshihiro Morita, Atsushi Yao, Yu Nagashima, Yasunobu Hirata, Ryozo Nagai
    Internal medicine (Tokyo, Japan) 45 20 1147 - 51 2006年 [査読有り][通常論文]
     
    An increasing number of patients with tetralogy of Fallot (TOF) are reaching older age. We encountered a 75-year-old woman with uncorrected TOF and concomitant severe coronary artery disease (CAD) with congestive heart failure. Her CAD risk factor was hyperlipidemia, which had been untreated. Successful percutaneous coronary interventions have improved her clinical condition and provided long-term survival. Although CAD is considered to be a rare complication in adults with TOF, both strict modification of CAD risk factors and early detection of CAD would be also required in this population, given the residual TOF lesions relating to acute exacerbation of clinical presentation.
  • Tsutomu Shimizu, Norifumi Takeda, Masao Takahashi, Yasushi Imai, Nobukazu Ishizaka, Yasunobu Hirata, Ryozo Nagai
    Internal medicine (Tokyo, Japan) 45 20 1189 - 90 2006年 [査読有り][通常論文]
  • Ryo Takeda, Hiroaki Nishimatsu, Etsu Suzuki, Hiroshi Satonaka, Daisuke Nagata, Shigeyoshi Oba, Masataka Sata, Masao Takahashi, Yuji Yamamoto, Yasuo Terauchi, Takashi Kadowaki, Kenji Kangawa, Tadaichi Kitamura, Ryozo Nagai, Yasunobu Hirata
    Journal of the American Society of Nephrology : JASN 17 1 113 - 21 2006年01月 [査読有り][通常論文]
     
    Growth hormone and IGF-1 have been suggested to have tissue-protective effects. Ghrelin is a stomach-derived growth hormone secretagogue. The effects of ghrelin on ischemia/reperfusion-induced renal failure in mice were examined. Ischemic acute renal failure was induced by bilateral renal artery clamping for 45 min and reperfusion for 24 h. Ghrelin (100 microg/kg mouse) or vehicle was injected subcutaneously six times before surgery and three times after surgery every 8 h. Twenty-four hours after reperfusion, the right kidney was isolated and perfused. Acetylcholine (ACh)- and adrenomedullin-induced endothelium-dependent vasorelaxation of renal vessels significantly improved in ghrelin-pretreated mice (%Delta renal perfusion pressure by 10(-7) M ACh -63.5 +/- 3.7 versus -41.2 +/- 5.5%; P < 0.05). This change was associated with significant increases of nitric oxide release in the kidneys of ghrelin-treated mice (10(-7) M ACh 35.5 +/- 5.8 versus 16.9 +/- 3.5 fmol/g kidney per min; P < 0.05). Serum concentration of urea nitrogen (53 +/- 7 versus 87 +/- 15 mg/dl; P < 0.05) and renal injury score were significantly lower in the ghrelin group (2.5 +/- 0.8 versus 5.3 +/- 1.5; P < 0.01). Tubular apoptotic index was significantly lower in the ghrelin group (5 +/- 5 versus 28 +/- 4; P < 0.05). Furthermore, the survival rate after the 60-min ischemic period was higher in the ghrelin group (80 versus 20%; P < 0.05). Ghrelin treatment significantly increased the serum level of IGF-1. However, such renal protective effects of ghrelin on ischemia/reperfusion injury were not observed in insulin receptor substrate-2 knockout mice. These results suggest that ghrelin may protect the kidneys from ischemia/reperfusion injury and that this effect is related to an improvement of endothelial function through an IGF-1-mediated pathway.
  • Katsuhito Fujiu, Ichiro Manabe, Atsushi Ishihara, Yumiko Oishi, Hiroshi Iwata, Go Nishimura, Takayuki Shindo, Koji Maemura, Hiroyuki Kagechika, Koichi Shudo, Ryozo Nagai
    Circulation research 97 11 1132 - 41 2005年11月 [査読有り][通常論文]
     
    Modulation of smooth muscle cell (SMC) phenotype plays a central role in neointima formation. We recently demonstrated that Am80, a synthetic retinoic acid receptor alpha-specific agonist, inhibits the activity of the transcription factor KLF5, which is essential for neointima formation after vascular injury. In the present study, we aimed to further analyze the mechanism by which Am80 inhibits KLF5 and the effects of inhibiting KLF5 on SMCs and vascular lesion formation, as well as to evaluate potential of Am80 for use in the prevention of in-stent neointima formation. We found that Am80 inhibited both the expression and transcriptional function of KLF5. Of particular interest was our finding that KLF5 forms a transcriptionally active complex with unliganded RAR/RXR heterodimer on the PDGF-A promoter; Am80 disrupts this complex, thereby inhibiting KLF5-dependent transcriptional activation. Knocking down KLF5 using small interfering RNA suppressed serum-induced downregulation of SMC differentiation marker gene expression in cultured SMCs, and haploinsufficiency of KLF5 in mice attenuated phenotypic modulation of SMCs after vascular injury, indicating that KLF5 plays a key role in the control of SMC phenotype. Am80 augmented expression of the SMC differentiation marker genes in culture and within the vessel walls, and oral administration of Am80 significantly inhibited in-stent neointima formation in a rabbit stent-placement model. Taken together, these results demonstrate that KLF5 plays an important role in the control of SMC phenotype after vascular injury and suggest the feasibility of using Am80, delivered systemically and/or with a drug eluting stent, to prevent in-stent neointima formation.
  • N Ishizaka, K Saito, Mori, I, G Matsuzaki, M Ohno, R Nagai
    ARTERIOSCLEROSIS THROMBOSIS AND VASCULAR BIOLOGY 25 11 2282 - 2288 2005年11月 [査読有り][通常論文]
     
    Objective-We have investigated whether long-term administration of angiotensin (Ang) II causes ferritin induction and iron accumulation in the rat aorta, and their possible relation to regulatory effects on gene expression and vascular function in Ang II-infused animals. Methods and Results-Sprague-Dawley rats were given Ang II for 7 days via subcutaneously implanted osmotic minipumps. Ang II infusion caused a >20-fold increase in ferritin protein expression over control values. Immunohistochemistry showed that Ang II infusion markedly increased the ferritin expression in the aortic endothelial and adventitial cells, with some of the latter being identified as monocytes/macrophages. Prussian blue staining showed that stainable iron was observed in the adventitial layer of aorta from Ang II-infused animals, but not in the endothelial layer. Chelation of iron suppressed aortic induction of ferritin and also the oxidative stress markers, heme oxygenase-1 and 4-hydroxynonenal-modified protein adducts. In addition, iron chelation attenuated Ang II-induced impairment of aortic relaxations in response to acetylcholine and sodium nitroprusside and suppressed upregulation of mRNA levels of monocyte chemoattractant protein-1. Iron chelation also partially attenuated the medial thickening and perivascular fibrosis induced by Ang II infusion for 4 weeks. Conclusion-Ang II infusion caused ferritin induction and iron deposition in the aortas. These phenomena might have a role in the regulation of gene expression, impairment of vascular function, and arterial remodeling induced by Ang II, which are presumably mediated in part by enhancement of oxidative stress.
  • K Monzen, T Hosoda, D Hayashi, Y Imai, Y Okawa, T Kohro, H Uozaki, T Nishiyama, M Fukayama, R Nagai
    BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS 337 2 534 - 539 2005年11月 [査読有り][通常論文]
     
    Current medical transplantation confronts major problems such as the shortage of donors and geographical restrictions that inhibit efficient utilization of finite donor organs within their storage lives. To overcome these issues, expanding organ preservation time has become a major concern. We investigated whether a strategy which best preserves organ grafts can be achieved by the use of a newly developed refrigerating chamber, which is capable of establishing a supercooled and unfrozen state stably by generating an electrostatic field in its inside. When adult rat organs such as heart, liver, and kidneys were stored in the supercooled conditions, the levels of major biochemical markers leaked from the preserved organs were significantly lower than in the ordinary hypothermic storage. No apparent tissue damages were observed histologically after the supercooled preservation. Our results suggest that the use of this supercooling refrigerator improves organ preservation and may provide an innovative technique for human organ transplantation. (c) 2005 Elsevier Inc. All rights reserved.
  • K Saito, N Ishizaka, M Hara, G Matsuzaki, M Sata, Mori, I, M Ohno, R Nagai
    HYPERTENSION 46 5 1180 - 1185 2005年11月 [査読有り][通常論文]
     
    Abnormal lipid metabolism may play a role in progressive renal failure. We studied whether lipid accumulation occurs and whether lipid deposits are colocalized with transforming growth factor-beta 1 (TGF-beta 1) in the kidney of angiotensin II-infused animals. Oil red 0 staining showed marked lipid deposition in the tubular epithelial and vascular wall cells of angiotensin II-treated but not in norepinephrine-treated rats. Histological analyses showed that increased amounts of superoxide and intense TGF-beta 1 mRNA expression were present in lipid-positive tubular epithelial cells in angiotensin II-infused animals. Protein expression of sterol regulatory element-binding protein I (SREBP-1) and mRNA expression of fatty acid synthase in the kidney were approximate to 3 times and 1.5 times, respectively, higher in angiotensin II-treated rats than in controls. Treatment of angiotensin II-infused animals with an iron chelator, deferoxamine, attenuated the angiotensin II-induced increases in renal expression of SREBP-1 and fatty acid synthase and normalized the lipid content in the renal cortical tissues. Abnormal lipid metabolism may be associated with upregulation of TGF-beta 1 I expression and aberrant iron homeostasis in the kidneys of angiotensin II-infused animals.
  • 荻野 展広, 松崎 弦, 長崎 実佳, 今井 靖, 大野 実, 平田 恭信, 永井 良三, 伊豆津 宏二, 吉田 成孝
    Circulation Journal 69 Suppl.III 929 - 929 (一社)日本循環器学会 2005年10月
  • Haruhito Takano, Toshihiro Morita, Haruko Iida, Ken-ichi Asada, Masayoshi Kato, Kansei Uno, Ken Hirose, Akihiro Matsumoto, Katsu Takenaka, Yasunobu Hirata, Fumio Eto, Ryozo Nagai, Yoshiaki Sato, Toshiaki Nakajima
    European journal of applied physiology 95 1 65 - 73 2005年09月 [査読有り][通常論文]
     
    We investigated the hemodynamic and hormonal responses to a short-term low-intensity resistance exercise (STLIRE) with the reduction of muscle blood flow. Eleven untrained men performed bilateral leg extension exercise under the reduction of muscle blood flow of the proximal end of both legs pressure-applied by a specially designed belt (a banding pressure of 1.3 times higher than resting systolic blood pressure, 160-180 mmHg), named as Kaatsu. The intensity of STLIRE was 20% of one repetition maximum. The subjects performed 30 repetitions, and after a 20-seconds rest, they performed three sets again until exhaustion. The superficial femoral arterial blood flow and hemodynamic parameters were measured by using the ultrasound and impedance cardiography. Serum concentrations of growth hormone (GH), vascular endothelial growth factor (VEGF), noradrenaline (NE), insulin-like growth factor (IGF)-1, ghrelin, and lactate were also measured. Under the conditions with Kaatsu, the arterial flow was reduced to about 30% of the control. STLIRE with Kaatsu significantly increased GH (0.11+/-0.03 to 8.6+/-1.1 ng/ml, P < 0.01), IGF-1 (210+/-40 to 236+/-56 ng/ml, P < 0.01), and VEGF (41+/-13 to 103+/-38 pg/ml, P < 0.05). The increase in GH was related to neither NE nor lactate, but the increase in VEGF was related to that in lactate (r = 0.57, P < 0.05). Ghrelin did not change during the exercise. The maximal heart rate (HR) and blood pressure (BP) in STLIRE with Kaatsu were higher than that without Kaatsu. Stroke volume (SV) was lower due to the decrease of the venous return by Kaatsu, but, total peripheral resistance (TPR) did not change significantly. These results suggest that STLIRE with Kaatsu significantly stimulates the exercise-induced GH, IGF, and VEGF responses with the reduction of cardiac preload during exercise, which may become a unique method for rehabilitation in patients with cardiovascular diseases.
  • 後腹膜線維症を合併した収縮性心膜炎の1例
    志賀 哲也, 細谷 弓子, 松本 晃裕, 永江 玄太, 武田 憲文, 岡崎 具樹, 世古 義規, 大野 実, 平田 恭信, 永井 良三
    日本内科学会関東地方会 529回 31 - 31 日本内科学会-関東地方会 2005年09月 [査読有り][通常論文]
  • Haruko Iida, Taisuke Jo, Kuniaki Iwasawa, Toshihiro Morita, Hisako Hikiji, Tsuyoshi Takato, Teruhiko Toyo-Oka, Ryozo Nagai, Toshiaki Nakajima
    British journal of pharmacology 146 1 49 - 59 2005年09月 [査読有り][通常論文]
     
    The A-type voltage-dependent K(+) current (I(A)) has been identified in several types of smooth muscle cells including the pulmonary artery (PA), but little is known about the pharmacological and molecular characteristics of I(A) in human pulmonary arterial smooth muscle cells (hPASMCs). We investigated I(A) expressed in cultured PASMCs isolated from the human main pulmonary artery, using patch-clamp techniques, reverse transcriptase-polymerase chain reaction (RT-PCR), quantitative real-time RT-PCR and immunocytochemical studies. With high EGTA and ATP in the pipette, the outward currents were dominated by a transient K(+) current (I(A)), followed by a relatively small sustained outward current (I(K)). I(A) was inhibited by 4-aminopyridine (4-AP) concentration-dependently, and could be separated pharmacologically into two components by tetraethylammonium (TEA) sensitivity. A component was sensitive to TEA, and the second component was insensitive to TEA. I(A) was inhibited by blood depressing substrate (BDS)-II, a specific blocker of K(V)3.4 subunit, and phrixotoxin-II, a specific blocker of K(V)4.2 and 4.3. Flecainide inhibited I(A) concentration-dependently, but it inhibited it preferentially in the presence of TEA (TEA-insensitive I(A)). Systematic screening of expression of K(V) genes using RT-PCR showed the definite presence of transcripts of the I(A)-encoding genes for K(V)3.4, K(V)4.1, K(V)4.2 and K(V)4.3 as well as the I(K)-encoding genes for K(V)1.1, K(V)1.5 and K(V)2.1. The real-time RT-PCR analysis showed that the relative abundance of the encoding genes of I(A) alpha-subunit and K(V) channel-interacting proteins (KChIPs) was K(V)4.2 > K(V)3.4 > K(V)4.3 (long) > K(V)4.1, and KChIP3 > KChIP2, respectively. The presence of K(V)3.4, K(V)4.2 and K(V)4.3 proteins was also demonstrated by immunocytochemical studies, and confirmed by immunohistochemical staining using intact human PA sections. These results suggest that I(A) in cultured hPASMCs consists of two kinetically and pharmacologically distinct components, probably K(V)3.4 and K(V)4 channels.
  • Satoshi Nishimura, Hiroshi Yamashita, Masayoshi Katoh, Kelly P. Yamada, Kenji Sunagawa, Yasutake Saeki, Yosiki Ohnuki, Ryozo Nagai, Seiryo Sugiura
    Journal of Molecular and Cellular Cardiology 39 2 231 - 239 2005年08月 [査読有り][通常論文]
     
    To understand the pathophysiology of hereditary cardiomyopathy, the contractile function of cardiomyopathic hamsters has been studied at the cellular level. However, most of the studies to date have described the cell shortening under the unloaded condition. Using a novel force-length measurement system for single cardiomyocytes, we studied the contractile function of cardiomyopathic hamster myocytes over a wide range of loading conditions. Cardiomyocytes were isolated from the ventricles of eight- to 10-week-old cardiomyopathic (CMP) hamsters (Bio TO-2 strain), as well as control (CTRL) Syrian hamsters. A pair of carbon fibers was attached to both ends of single cardiomyocytes and their contractile characteristics were recorded while changing the after-load by controlling the fiber motion. Under the unloaded condition, the shortening fraction (CMP 9.2 ± 0.5% vs. CTRL 10.7 ± 0.8%, P = 0.06) and maximum shortening velocity (CMP 98.2 ± 7.3 μm/s vs. CTRL 147.2 ± 6.5 μm/s, P < 0.05) were decreased in CMP hamster myocytes. The peak force under the isometric condition (CMP 35.8 ± 2.2 mN/mm2 vs. CTRL 69.0 ± 8.4 mN/mm2, P < 0.05) and external work (CMP 898 ± 130 J/m3 vs. CTRL 3058 ± 576 J/m3, P < 0.05) under physiologically loaded conditions were also decreased, but the differences were more pronounced under the loaded conditions. Calcium transients measured by Indo-1 revealed elevated diastolic level, decreased peak level, and slower diastolic decay in CMP myocytes thus being consistent with the observed contractile dysfunction. These results clearly indicate the importance of the loading conditions in evaluating the contractile function of CMP hamster myocytes, and may provide insights into the mechanism of contractile dysfunction in this disease. © 2005 Elsevier Ltd. All rights reserved.
  • N Ishizaka, Y Ishizaka, EI Toda, H Hashimoto, R Nagai, M Yamakado
    ATHEROSCLEROSIS 181 2 381 - 388 2005年08月 [査読有り][通常論文]
     
    Cigarette smoking is associated with increased insulin resistance and other metabolic abnormalities. Here, we investigate the prevalence of metabolic syndrome (MetS) in cigarette smokers and people who never smoked by analyzing cross-sectional data of 5033 subjects aged between 35 and 65 years who underwent general health screening. Both former and current smoking was associated with an increased incidence of metabolic syndrome defined by modified-National Cholesterol Education Program (NCEP) criteria with odds ratios of 1.77 (9517o CI 1.42-2.22, P < 0.0001) and 2.38 (95% CI 1.95-2.91, P < 0.0001), respectively. In both former and current smokers, prevalence of metabolic syndrome increased when the duration of cigarette smoking was >= 10 years. The positive association between metabolic syndrome and smoking was only partially reversed even 5 years after quitting. Multivariate logistic regression analysis showed that metabolic syndrome was an independent risk factor for carotid plaque with an odds ratio of 1.72 (95% CI 1.43-2.08, P < 0.0001). On the other hand, when limited to individuals without metabolic syndrome, former and current smoking was still found to be associated with carotid plaque with odds ratios of 1.49 (95% CI 1.15-1.92, P = 0.0023) and 1.57 (95% CI 1.22-2.03, P = 0.0005), respectively, in men. Collectively, these data suggest that the atherogenic consequences of smoking may, at least in part, be explained by its association with metabolic syndrome. (c) 2005 Elsevier Ireland Ltd. All rights reserved.
  • R Nagai, T Suzuki, K Aizawa, T Shindo, I Manabe
    Journal of thrombosis and haemostasis : JTH 3 8 1569 - 76 2005年08月 [査読有り][通常論文]
     
    Structural remodeling of the heart and blood vessels is an important pathologic process in the development of many cardiovascular diseases. However, transcriptional regulation of altered gene expression during cardiovascular remodeling is not well understood. We previously isolated KLF5/basic transcription element-binding (BTEB)2, a Krüppel-like factor, as a transcription factor that binds the promoter of the embryonic smooth muscle myosin heavy chain gene (SMemb). KLF5 activates many genes inducible during cardiovascular remodeling, such as platelet-derived growth factor (PDGF)-A/B, Egr-1, plasminogen activator inhibitor-1 (PAI-1), inducible nitric oxide synthase (iNOS), and vascular endothelial growth factor (VEGF) receptors. KLF5 is abundantly expressed in embryonic smooth muscles and is down-regulated with vascular development, but reinduced in proliferative neointimal smooth muscles in response to vascular injury. In KLF5 gene-targeted mice, homozygotes die at an early embryonic stage whereas heterozygotes are apparently normal. However, in response to external stress, arteries of heterozygotes exhibit diminished levels of smooth muscle and adventitial cell activation. Furthermore, angiotensin II-induced cardiac hypertrophy and fibrosis are attenuated in heterozygotes. KLF5 activities are regulated by many transcriptional regulators and nuclear receptors, such as retinoic acid receptor-alpha (RAR alpha), NF-kappaB, PPAR gamma, p300, and SET. Interestingly, RAR alpha agonist suppresses KLF5 and cardiovascular remodeling, whereas RAR alpha antagonist activates KLF5 and induces angiogenesis. These results indicate that KLF5 is an essential transcription factor in cardiovascular remodeling and a potential therapeutic target for cardiovascular disease.
  • Makoto Sahara, Masataka Sata, Yumi Matsuzaki, Kimie Tanaka, Toshihiro Morita, Yasunobu Hirata, Hideyuki Okano, Ryozo Nagai
    Stem cells (Dayton, Ohio) 23 7 874 - 8 2005年08月 [査読有り][通常論文]
     
    In contrast to conventional assumption, recent reports propose the possibility that hematopoietic stem cells (HSCs) may have broader potential to differentiate into various cell types. Here, we tested the pluripotency of HSCs by comparing vascular lesions induced by mechanical injury after bone marrow reconstitution with total bone marrow (TBM) cells, c-Kit+ Sca-1+ Lin- (KSL) cells, or a single HSC cell (Tip-SP CD34-KSL cell, CD34- c-Kit+ Sca-1+ Lin- cell with the strongest dye-efflux activity) harboring green fluorescent protein (GFP). The lesions contained a significant number of GFP-positive cells in the TBM and KSL groups, whereas GFP-positive cells were rarely detected in the HSC group. These results suggest that transdifferentiation of a highly purified HSC seems to be a rare event, if it occurs at all, whereas bone marrow cells including the KSL fraction can give rise to vascular cells that substantially contribute to repair or lesion formation after mechanical injury.
  • Yuho Najima, Naoya Yahagi, Yoshinori Takeuchi, Takashi Matsuzaka, Motohiro Sekiya, Yoshimi Nakagawa, Michiyo Amemiya-Kudo, Hiroaki Okazaki, Sachiko Okazaki, Yoshiaki Tamura, Yoko Iizuka, Ken Ohashi, Kenji Harada, Takanari Gotoda, Ryozo Nagai, Takashi Kadowaki, Shun Ishibashi, Nobuhiro Yamada, Jun-ichi Osuga, Hitoshi Shimano
    The Journal of biological chemistry 280 30 27523 - 32 2005年07月 [査読有り][通常論文]
     
    Sterol regulatory element-binding proteins (SREBPs) are transcription factors that are predominately involved in the regulation of lipogenic and cholesterogenic enzyme gene expression. To identify unknown proteins that interact with SREBP, we screened nuclear extract proteins with 35S-labeled SREBP-1 bait in Far Western blotting analysis. Using this approach, high mobility group protein-B1 (HMGB1), a chromosomal protein, was identified as a novel SREBP interacting protein. In vitro glutathione S-transferase pull-down and in vivo coimmunoprecipitation studies confirmed an interaction between HMGB1 and both SREBP-1 and -2. The protein-protein interaction was mediated through the helix-loop-helix domain of SREBP-1, residues 309-344, and the A box of HMGB1. Furthermore, an electrophoretic mobility shift assay demonstrated that HMGB1 enhances SREBPs binding to their cognate DNA sequences. Moreover, luciferase reporter analyses, including RNA interference technique showed that HMGB1 potentiates the transcriptional activities of SREBP in cultured cells. These findings raise the intriguing possibility that HMGB1 is potentially involved in the regulation of lipogenic and cholesterogenic gene transcription.
  • Sahohime Matsumoto, Makoto Miyagishi, Hideo Akashi, Ryozo Nagai, Kazunari Taira
    Journal of Biological Chemistry 280 27 25687 - 25696 2005年07月 [査読有り][通常論文]
     
    We have developed an original vector library that allowed us to exploit the phenomenon of RNA interference but also allowed us to avoid the confounding effects of the interferon response. In the present work, we used our library of small interfering RNA expression vectors to examine the genes involved in apoptosis that was induced by double-stranded RNA. To our surprise, screening of our library revealed two novel double-stranded RNA-induced apoptotic pathways, a JNK/SAPK-mediated mitochondrial pathway and an ERK2-related pathway, both of which appeared to be independent of the serine-threonine protein kinase-dependent caspase pathway. We also found that MST2 and protein kinase Ca both activated the pro-apoptotic signal mediated by ERK2. The results of our screening analysis suggested the utility of large scale screenings with libraries of small interfering RNA expression vectors. © 2005 by The American Society for Biochemistry and Molecular Biology, Inc.
  • Kimie Tanaka, Masataka Sata, Daiju Fukuda, Yoshihiro Suematsu, Noboru Motomura, Shinichi Takamoto, Yasunobu Hirata, Ryozo Nagai
    Journal of the American College of Cardiology 46 1 134 - 41 2005年07月 [査読有り][通常論文]
     
    OBJECTIVES: The present study was designed to assess aortic valve morphology and function in mice of advanced age. We also evaluated the potential contribution of bone-marrow-derived cells to the pathogenesis of aortic stenosis. BACKGROUND: Age-associated valvular degeneration is characterized by lipid accumulation, collagen deposition, and calcification containing smooth muscle-like cells and osteoblast-like cells. Cellular and molecular factors that mediate these changes remain unknown. METHODS: We extensively examined the aortic valves of senile wild-type and apolipoprotein E (ApoE)-/- mice with echocardiography. The aortic valves were analyzed by immunohistochemistry and electron microscopy. The bone marrow of wild-type and ApoE-/- mice was reconstituted with that of green fluorescent protein (GFP) or beta-galactosidase (LacZ) mice, which expressed GFP or LacZ ubiquitously. RESULTS: Transaortic flow velocity was correlated with age in wild-type and ApoE-/- mice. The aortic valves of old ApoE-/- mice showed sclerosis that resembled the pathology of human aortic stenosis. A significant number of GFP-positive cells (10.7 +/- 4.1%) in the sclerotic valves of ApoE-/- mice expressed alpha-smooth muscle actin, whereas most of the GFP-positive cells were identified as endothelial cells or macrophages in wild-type mice. There were bone-marrow-derived cells that were positive for osteoblast-related proteins near the sites of ectopic calcification. The sclerotic valves displayed frequent apoptotic cell death and chemokine expression. CONCLUSIONS: Senile ApoE-deficient mice display aortic valve sclerosis that is similar to that observed in humans. The sclerotic valves displayed frequent apoptotic cell death and chemokine expression. Smooth muscle-like cells observed in degenerative valves might derive, at least in part, from bone marrow.
  • K Hara, M Horikoshi, H Kitazato, T Yamauchi, C Ito, M Noda, J Ohashi, P Froguel, K Tokunaga, R Nagai, T Kadowaki
    Diabetologia 48 7 1307 - 14 2005年07月 [査読有り][通常論文]
     
    AIMS/HYPOTHESIS: Secreted by adipocytes, adiponectin is a hormone that acts as an antidiabetic and anti-atherogenic adipokine. We recently cloned the genes encoding two adiponectin receptors (ADIPOR1 and ADIPOR2). The aim of this study was to examine whether ADIPOR1 and/or ADIPOR2 play a major role in genetic susceptibility to insulin resistance or type 2 diabetes in the Japanese population. METHODS: By direct sequencing and a search of public databases, we identified single nucleotide polymorphisms (SNPs) in ADIPOR1 and ADIPOR2, and investigated whether these SNPs are associated with insulin resistance and type 2 diabetes in the Japanese population. RESULTS: The linkage disequilibrium (LD) in the chromosomal region of ADIPOR1 was almost completely preserved, whereas the LD in ADIPOR2 was less well preserved. None of the SNPs in ADIPOR1 or ADIPOR2 were significantly associated with insulin resistance or type 2 diabetes. No differences in ADIPOR1 or ADIPOR2 haplotype frequencies were observed between type 2 diabetic and non-diabetic subjects. CONCLUSIONS/INTERPRETATION: Genetic variations in ADIPOR1 or ADIPOR2 are unlikely to lead to a common genetic predisposition to insulin resistance or type 2 diabetes in the Japanese population.
  • Taisuke Jo, Haruko Iida, Shinya Kishida, Hiroyuki Imuta, Hitoshi Oonuma, Taiji Nagata, Hajime Hara, Kuniaki Iwasawa, Masaaki Soma, Yoshiaki Sato, Takahide Nagase, Ryozo Nagai, Toshiaki Nakajima
    Biochemical and biophysical research communications 331 4 1452 - 9 2005年06月 [査読有り][通常論文]
     
    This study investigated acute and chronic effects of eicosapentaenoic acid (EPA) on voltage-gated Na+ current (I(Na)) expressed in cultured human bronchial smooth muscle cells (hBSMCs). The whole-cell voltage clamp technique and quantitative real-time RT-PCR analysis were applied. The alterations in the fatty acid composition of phospholipids after treatment with EPA were also examined. Extracellular application of EPA produced a rapid and concentration-dependent suppression of tetrodotoxin-sensitive I(Na) with the half-maximal inhibitory concentration of 2 microM. After washing out EPA with albumin, I(Na) returned to the control level. Similar inhibitory effects were observed regarding other fatty acids (docosahexaenoic, arachidonic, stearic, and oleic acids), but EPA was the most potent inhibitor. The effect of EPA on I(Na) was not blocked by nordihydroguaiaretic acid and indometacin, and was accompanied by a significant shift of the steady-state inactivation curve to more negative potentials. In cells chronically treated with EPA, the EPA content of the cell lipid fraction (mol%) increased time-dependently, while arachidonic acid (AA) decreased, resulting in an increase of EPA to AA ratio. Then, the level of mRNA (SCN9A) encoding I(Na) decreased significantly. These results provide novel evidence that EPA not only rapidly inhibits I(Na), but also reduces the mRNA levels of the Na+ channel after cellular incorporation of EPA in cultured hBSMCs.
  • E Amiya, N Ishizaka, A Watanabe, Y Endo, R Itou, S Yoshida, M Nangaku, R Nagai
    CIRCULATION JOURNAL 69 6 760 - 762 2005年06月 [査読有り][通常論文]
     
    A 66-year old man, who had been diagnosed with dilated cardiomyopathy and felt a progressive shortness of breath and fatigability, was admitted to hospital. Computed. tomography showed a thickening of the aortic wall from the aortic arch to the aortic bifurcation, as well as mild pleural and pericardial effusion. Intravenous pyelography showed severe ureteral stenosis, along with hydronephrosis, of the left side. There was a marked increase in C-reactive protein and the erythrocyte sedimentation rate, but the serology for connective tissue disease and perinuclear antineutrophil cytoplasmic antibodies was negative. Retroperitoneal fibrosis (RPF) with intrathoracic extension was diagnosed. After confirming the absence of malignant disease, an oral predonisolone treatment of 30 mg/day was started, and this ameliorated the ureteral obstruction, aortic wall thickening and pericardial effusion. The patient had been taking 300 mg of loxoprofen sodium for headaches every day for 16 years. The relationship between loxoprofen, cardiomyropathy and RPF remains unclear. There is a possibility of RPF in the patients with a thickening of thoracic aortic wall, as in this case.
  • K Meguro, H Adachi, S Oshima, K Taniguchi, R Nagai
    CIRCULATION JOURNAL 69 6 695 - 699 2005年06月 [査読有り][通常論文]
     
    Background Sleep apnea syndrome (SAS) and exercise hyperpnea are common in patients with chronic heart failure (CHF), and although it is not known whether they are both regulated by the same mechanisms, the hypothesis of the present study was that they are related to augmented central chemosensitivity. Methods and Results The oxygen desaturation index (ODI) was evaluated in 29 patients and those with ODI > 5 times/h underwent polysomnography. Patients with an apnea-hypopnea index (AHI) > 15/h without evidence of obstructive apnea were defined as central SAS (CSAS). Cardiopulmonary exercise testing was performed to determine peak oxygen uptake and the VE-VCO2 Slope. A hypercapnic gas mixture (7% CO2/93% O-2) was used to activate the central chemoreflex. Nine patients had central SAS (CHF-CSAS) and 20 did not have apnea (CHF-nonSAS). Patients with CHF-CSAS had a lower peak oxygen uptake than the CHF-nonSAS group (13.0 +/- 2.4 vs 16.9 +/- 4.3 ml (.) kg(-1) (.) min-, p < 0.05). There was a significant correlation between central chemosensitivity and the AHI. (r=0:63, p < 0.05), between central chemosensitivity and the VE-VCO2 slope (r=0.50, p < 0.01), whereas the VE-VCO2 slope showed an insignificant tendency to correlate with AHI (r=0.44, p=0.07). Conclusion CHF-CSAS is associated with impaired exercise tolerance and elevated central chemosensitivity is the responsible mechanism for CSAS and exercise hyperpnea.
  • Naoya Yahagi, Hitoshi Shimano, Kiyoshi Hasegawa, Kenichi Ohashi, Takashi Matsuzaka, Yuho Najima, Motohiro Sekiya, Sachiko Tomita, Hiroaki Okazaki, Yoshiaki Tamura, Yoko Iizuka, Ken Ohashi, Ryozo Nagai, Shun Ishibashi, Takashi Kadowaki, Masatoshi Makuuchi, Shin Ohnishi, Jun-ichi Osuga, Nobuhiro Yamada
    European journal of cancer (Oxford, England : 1990) 41 9 1316 - 22 2005年06月 [査読有り][通常論文]
     
    Hepatocellular carcinoma is a very common neoplastic disease in countries where hepatitis viruses B and/or C are prevalent. Small hepatocellular carcinoma lesions detected by ultrasonography at an early stage are often hyperechoic because they are composed of well-differentiated cancer cells that are rich in triglyceride droplets. The triglyceride content of hepatocytes depends in part on the rate of lipogenesis. Key lipogenic enzymes, such as fatty acid synthase, are co-ordinately regulated at the transcriptional level. We therefore examined the mRNA expression of lipogenic enzymes in human hepatocellular carcinoma samples from 10 patients who had undergone surgical resection. All of the samples exhibited marked elevation of expression of mRNA for lipogenic enzymes, such as fatty acid synthase, acetyl-CoA carboxylase and ATP citrate lyase, compared with surrounding non-cancerous liver tissue. In contrast, the changes in mRNA expression of SREBP-1, a transcription factor that regulates a battery of lipogenic enzymes, did not show a consistent trend. In some cases where SREBP-1 was elevated, the main contributing isoform was SREBP-1c rather than SREBP-1a. Thus, lipogenic enzymes are markedly induced in hepatocellular carcinomas, and in some cases SREBP-1c is involved in this activation.
  • N Ishizaka, Y Ishizaka, EI Toda, R Nagai, M Yamakado
    ARTERIOSCLEROSIS THROMBOSIS AND VASCULAR BIOLOGY 25 5 1038 - 1044 2005年05月 [査読有り][通常論文]
     
    Objective - There are few data available on possible independent association between uric acid and carotid atherosclerosis. Here we first sought to investigate association between uric acid levels and metabolic syndrome in Japanese; second, we assessed whether there is an independent association of uric acid with prevalence of carotid atherosclerosis in individuals subdivided according to gender and metabolic syndrome status. Methods and Results - Cross-sectional data from 8144 individuals who underwent general health screening were analyzed. After adjusting for age, total cholesterol, and smoking status, the odds ratios ( 95% CI) of sex-specific quartiles of serum uric acid for metabolic syndrome were 1.0, 1.06 (0.60 to 1.87), 2.18 (1.30 to 3.64), and 4.17 (2.56 to 6.79) in women, and 1.0, 0.92 (0.74 to 1.14), 1.52 (1.25 to 1.65), and 1.97 (1.61 to 2.40) in men. After adjusting for age, serum levels, total cholesterol, and smoking status, prevalence of carotid plaque was higher in subjects in the second, third, and fourth quartiles of uric acid level with odds ratios ( 95% CI) of 1.24 (1.01 to 1.52), 1.37 (1.11 to 1.68), and 1.31 (1.05 to 1.63), respectively, in men without metabolic syndrome but not in men with metabolic syndrome or in women with or without metabolic syndrome. Conclusion - The prevalence of metabolic syndrome showed a graded increase according to serum uric acid values in both genders. In men who did not have metabolic syndrome, uric acid was found to be an independent risk factor for incidence of carotid plaque.
  • Krppel-like transcription factor 5は脂肪細胞分化において重要である
    大石 由美子, 真鍋 一郎, 戸辺 一之, 都島 健介, 新藤 隆行, 山内 敏正, 門脇 孝, 永井 良三
    糖尿病 48 Suppl.2 S137 - S137 (一社)日本糖尿病学会 2005年04月 [査読有り][通常論文]
  • Hiroyuki Morita, Yuichiro Saito, Noriko Ohashi, Masayoshi Yoshikawa, Makoto Katoh, Terunao Ashida, Hiroki Kurihara, Tetsuya Nakamura, Masahiko Kurabayashi, Ryozo Nagai
    Circulation journal : official journal of the Japanese Circulation Society 69 4 475 - 80 2005年04月 [査読有り][通常論文]
     
    BACKGROUND: Hyperhomocysteinemia induces vascular endothelial dysfunction, contributing to a predisposition to the onset and/or progression of atherosclerosis. The major mechanism suggested for the adverse effect of homocysteine on vascular function seems to involve oxidative stress. Thus, we hypothesized that the administration of 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor fluvastatin, which is experimentally demonstrated to have antioxidative properties as one of its pleiotropic effects, is a useful strategy for eliminating the detrimental events induced by hyperhomocysteinemia. METHODS AND RESULTS: In diet-induced hyperhomocysteinemic rats, we estimated oxidative stress and assessed endothelium-dependent vasodilatation. Hyperhomocysteinemia induced significant increases in urinary 8-isoprostaglandin F2alpha-III excretion and vascular superoxide generation, and impaired endothelium-dependent vasodilatation. Additional oral administration of the antioxidant fluvastatin or vitamin E, which normalized increased oxidative stress induced by hyperhomocysteinemia, ameliorated endothelial dysfunction. CONCLUSIONS: Hyperhomocysteinemia, even mild to moderate, induces endothelial dysfunction through its oxidative effect. The antioxidant fluvastatin was able to cancel out the oxidative stress induced by hyperhomocysteinemia and ameliorate endothelial dysfunction. Clinical use of fluvastatin might be a potent strategy for eliminating the detrimental events induced by hyperhomocysteinemia as well as hyperlipidemia. In addition to lowering homocysteine by means of folate supplementation, administration of the antioxidants is expected to be a potentially effective anti-homocysteine therapy.
  • Takayoshi Matsumura, Toru Suzuki, Kenichi Aizawa, Yoshiko Munemasa, Shinsuke Muto, Masami Horikoshi, Ryozo Nagai
    The Journal of biological chemistry 280 13 12123 - 9 2005年04月 [査読有り][通常論文]
     
    Transcription is regulated by a network of transcription factors and related cofactors that act in concert with the general transcription machinery. Elucidating their underlying interactions is important for understanding the mechanisms regulating transcription. Recently, we have shown that Krüppel-like factor KLF5, a member of the Sp/KLF family of zinc finger factors and a key regulator of cardiovascular remodeling, is regulated positively by the acetylase p300 and negatively by the oncogenic regulator SET through coupled interaction and regulation of acetylation. Here, we have shown that the deacetylase HDAC1 can negatively regulate KLF5 through direct interaction. KLF5 interacts with HDAC1 in the cell and in vitro. Gel shift DNA binding assay showed that their interaction inhibits the DNA binding activity of KLF5, suggesting a property of HDAC1 to directly affect the DNA binding affinity of a transcription factor. Reporter assay also revealed that HDAC1 suppresses KLF5-dependent promoter activation. Additionally, overexpression of HDAC1 suppressed KLF5-dependent activation of its endogenous downstream gene, platelet-derived growth factor-A chain gene, when activated by phorbol ester. Further, HDAC1 binds to the first zinc finger of KLF5, which is the same region where p300 interacts with KLF5 and, intriguingly, HDAC1 inhibits binding of p300 to KLF5. Direct competitive interaction between acetylase and deacetylase has been hitherto unknown. Collectively, the transcription factor KLF5 is negatively regulated by the deacetylase HDAC1 through direct effects on its activities (DNA binding activity, promoter activation) and further through inhibition of interaction with p300. These findings suggest a novel role and mechanism for regulation of transcription by deacetylase.
  • K Saito, N Ishizaka, T Aizawa, M Sata, N Iso-o, E Noiri, Mori, I, M Ohno, R Nagai
    AMERICAN JOURNAL OF PHYSIOLOGY-HEART AND CIRCULATORY PHYSIOLOGY 288 4 H1836 - H1843 2005年04月 [査読有り][通常論文]
     
    Long-term administration of angiotensin II causes myocardial loss and cardiac fibrosis. We previously found iron deposition in the heart of the angiotensin II-infused rat, which may promote angiotensin II-induced cardiac damage. In the present study, we have investigated whether an iron chelator ( deferoxamine) and a free radical scavenger (T-0970) affect the angiotensin II-induced upregulation of transforming growth factor-beta 1 (TGF-beta 1). Angiotensin II infusion for 7 days caused a robust increase in TGF-beta 1 mRNA expression in vascular smooth muscle cells, myofibroblast-like cells, and migrated monocytes/macrophages. T-0970 and deferoxamine suppressed the upregulation of TGF-beta 1 mRNA and reduced the extent of cardiac fibrosis in the heart of rats treated with angiotensin II. These agents blocked the angiotensin II-induced upregulation of heme oxygenase-1, a potent oxidative and cellular stress-responsive gene, but they did not significantly affect systolic blood pressure or plasma levels of aldosterone. In addition, T-0970 and deferoxamine suppressed the angiotensin II-induced upregulation of monocyte chemoattractant protein-1 in the heart. These results collectively suggest that iron and the iron-mediated generation of reactive oxygen species may contribute to angiotensin II-induced upregulation of profibrotic and proinflammatory genes, such as TGF-beta 1 and monocyte chemoattractant protein-1.
  • N Ishizaka, K Saito, E Noiri, M Sata, H Ikeda, A Ohno, J Ando, Mori, I, M Ohno, R Nagai
    AMERICAN JOURNAL OF PHYSIOLOGY-REGULATORY INTEGRATIVE AND COMPARATIVE PHYSIOLOGY 288 4 R1063 - R1070 2005年04月 [査読有り][通常論文]
     
    We previously found that ANG II infusion into rats causes iron deposition in the kidney and heart, which may have a role in the regulation of profibrotic gene expression and tissue fibrosis. In the present study, we have investigated whether ANG II can also induce iron accumulation in the liver. Prussian blue staining detected frequent iron deposition in the interstitium of the liver of rats treated with pressor dose ANG II for 7 days, whereas iron deposition was absent in the livers of control rats. Immunohistochemical and histological analyses showed that some iron-positive nonparenchymal cells were positive for ferritin and heme oxygenase-1 (HO-1) protein and TGF-beta 1 mRNA and were judged to be monocytes/macrophages. It was shown that ANG II infusion caused about a fourfold increase in ferritin and HO-1 protein expression by Western blot analysis and about a twofold increase in TGF-beta 1 mRNA expression by Northern blot analysis, which were both suppressed by treating ANG II-infused rats with losartan and deferoxamine. In addition, mild interstitial fibrosis was observed in the liver of rats that had been treated with pressor dose ANG II for 7 days or with nonpressor dose ANG II for 30 days, the latter of which also caused loss of hepatocytes and intrahepatic hemorrhage in the liver. Taken together, our data suggest that ANG II infusion induces aberrant iron homeostasis in the liver, which may have a role in the ANG II-induced upregulation of profibrotic gene expression in the liver.
  • Hiroaki Nishimatsu, Etsu Suzuki, Hiroshi Satonaka, Ryo Takeda, Masao Omata, Toshiro Fujita, Ryozo Nagai, Tadaichi Kitamura, Yasunobu Hirata
    American journal of physiology. Heart and circulatory physiology 288 4 H1770-6 - 6 2005年04月 [査読有り][通常論文]
     
    To study the mechanisms of vascular dysfunction in diabetes mellitus, we examined the responses of the aorta to adrenomedullin (AM) and ANG II in obese Zucker (OZ), lean Zucker (LZ), and OZ rats administered fluvastatin (OZ + Flu). AM-induced endothelium-dependent vasorelaxation was impaired in OZ rats compared with LZ rats, and fluvastatin restored AM-induced, endothelium-dependent vasorelaxation (%Deltatension at 10(-7) mol/l AM; LZ, -85.1 +/- 3.1%; OZ, -50.7 +/- 2.5%; OZ + Flu, -75.6 +/- 2.7%). Expression of endothelial nitric oxide synthase (eNOS) and Akt phosphorylation in response to AM (10(-7) mol/l) were also diminished in OZ rats. Fluvastatin restored the eNOS expression and Akt phosphorylation [eNOS expression (relative intensity): LZ, 2.3 +/- 0.4; OZ, 1.0 +/- 0.2; OZ + Flu, 1.8 +/- 0.3; Akt phosphorylation (relative intensity): LZ, 2.3 +/- 0.2; OZ, 1.0 +/- 0.3; OZ + Flu, 1.9 +/- 0.2]. ANG II-induced vasoconstriction was enhanced in the aortic rings of OZ rats compared with LZ rats, and this enhanced vasoconstriction was partially normalized by fluvastatin and was abolished when the aorta of OZ rats was preincubated with the Rho kinase inhibitor Y-27632. GTPgammaS-induced contraction of permeabilized aortic smooth muscle cells, which is an indicator of the Rho-dependent Ca(2+) sensitization of contraction, was enhanced in OZ rats compared with LZ rats, and this enhanced contraction was suppressed in OZ + Flu rats. These results suggested that endothelium-dependent vasorelaxation was impaired, Ca(2+) sensitization of contraction was augmented in blood vessels of OZ rats and that fluvastatin restored vascular function by activating the Akt-dependent pathway and inhibiting the Rho-dependent pathway.
  • Ryo Takeda, Etsu Suzuki, Hiroshi Satonaka, Shigeyoshi Oba, Hiroaki Nishimatsu, Masao Omata, Toshiro Fujita, Ryozo Nagai, Yasunobu Hirata
    Circulation 111 11 1398 - 406 2005年03月 [査読有り][通常論文]
     
    BACKGROUND: It is well known that diabetes mellitus is a major risk factor for vascular diseases such as atherosclerosis and restenosis after angioplasty. It has become clear that advanced glycation end products (AGE) and their receptor (RAGE) are implicated in vascular diseases, especially in diabetes mellitus. Nevertheless, the mechanisms by which diabetes mellitus is often associated with vascular diseases remain unclear. METHODS AND RESULTS: To study the role of endogenous cytokines such as tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 in the development of vascular diseases and in the expression of RAGE, we used semapimod, a pharmacological inhibitor of cytokine production, and examined its effect on neointimal formation in the femoral artery of obese Zucker (OZ) rats. We also used an adenovirus construct expressing a dominant negative mutant of the receptor for TNF-alpha (AdTNFRDeltaC) to block the action of endogenous TNF-alpha. Semapimod significantly suppressed neointimal formation and RAGE expression in OZ rats compared with untreated OZ rats. This inhibitory effect of semapimod on neointimal formation was overcome by infection of an adenovirus expressing RAGE into the femoral artery of OZ rats. Furthermore, AdTNFRDeltaC infection significantly suppressed neointimal formation and RAGE expression in the femoral artery of OZ rats. CONCLUSIONS: These results suggest that endogenous cytokines, especially TNF-alpha, were implicated in neointimal formation in OZ rats and that RAGE was a mediator of the effect of these cytokines on neointimal formation.
  • Norimichi Koitabashi, Masashi Arai, Koichi Tomaru, Takako Takizawa, Atai Watanabe, Kazuo Niwano, Tomoyuki Yokoyama, Frank Wuytack, Muthu Periasamy, Ryozo Nagai, Masahiko Kurabayashi
    Biochemical and biophysical research communications 328 1 116 - 24 2005年03月 [査読有り][通常論文]
     
    Carvedilol is a beta-adrenoceptor blocker and a potent antioxidant that improves cardiac function in patients with heart failure. The restoration of sarcoplasmic reticulum Ca2+-ATPase (SERCA2) gene expression may be an underlying mechanism of its beneficial effects on cardiac function. In primary cultured neonatal rat cardiac myocytes, treatment with either carvedilol or its beta-receptor inactive metabolite, BM910228, attenuated the hydrogen peroxide-mediated decrease in SERCA2 mRNA and protein levels, while metoprolol, a pure beta-blocker, had no effect. Moreover, carvedilol itself significantly enhanced SERCA2 gene transcription, suggesting that carvedilol specifically restores SERCA2 gene transcription. Site-directed mutagenesis revealed that two Sp1 sites in the SERCA2 gene promoter region mediated the response to carvedilol under oxidative stress. Further, electrophoretic mobility shift assays revealed that Sp1 and Sp3 transcription factors correlated with carvedilol-mediated changes in the promoter assays. These studies may provide a mechanistic explanation for the beneficial effects of carvedilol in heart failure.
  • D Fukuda, M Sata, K Tanaka, R Nagai
    CIRCULATION 111 7 926 - 931 2005年02月 [査読有り][通常論文]
     
    Background - Neointimal hyperplasia is the major cause of in-stent restenosis (ISR). The sirolimus-eluting stent (SES) has emerged as a promising therapy to prevent ISR; however, the exact mechanism by which locally delivered sirolimus, an immunosuppressive agent, prevents ISR remains unknown. Recent evidence suggests that circulating progenitor cells may contribute to neointimal formation. Methods and Results - Mononuclear cells (MNCs) were isolated from peripheral blood of healthy human volunteers. Smooth muscle (SM)-like cells outgrew from the culture of MNCs (1 x 10(6)) in the presence of platelet-derived growth factor-BB and basic fibroblast growth factor, whereas endothelial cell - like cells were obtained in the presence of vascular endothelial growth factor. Sirolimus potently inhibited SM-like cell outgrowth. The number of SM-like cells was significantly reduced at a concentration as low as 0.1 ng/mL (15.9 +/- 5.8% of control, P < 0.001). Sirolimus also exerted an inhibitory effect on endothelial cell - like cells that originated from MNCs. Wire-mediated vascular injury was induced in femoral arteries of bone marrow chimeric mice. Either vehicle or sirolimus was administered locally to the perivascular area of the injured arteries. Sirolimus significantly reduced neointima hyperplasia at 4 weeks (intima/media ratio 2.0 &PLUSMN; 0.3 versus 1.0 &PLUSMN; 0.2, P < 0.05) with a decreased number of bone marrow - derived SM-like cells and hematopoietic cells in the lesion. Reendothelialization was retarded in the arteries treated with sirolimus. Conclusions - The potent inhibitory effects of sirolimus on circulating smooth muscle progenitor cells may mediate the clinical efficacy of SES, at least in part. Sirolimus potentially may affect reendothelialization after stent implantation.
  • Y Higashikuni, M Sata, R Nagai
    ACTA CARDIOLOGICA 60 1 77 - 79 2005年02月 [査読有り][通常論文]
     
    Tako-tsubo-like cardiomyopathy is a newly-recognized enigmatic disease characterized by transient left ventricular dysfunction of a broad area of the apex with a hyperkinetic area around the cardiac base. There is ST-segment elevation with no coronary stenosis. The exact mechanism for this entity remains unknown. Here, we report a case of tako-tsubo-like cardiomyopathy that showed a marked left ventricular hypertrophy (LVH) when the wall motion returned to normal. LVH was normalized at 10 months. The cause of LVH remains unknown.
  • Makoto Miyagishi, Sahohime Matsumoto, Takashi Futami, Hideo Akashi, Krishnarao Appasani, Yasuomi Takagi, Shizuyo Sutou, Takashi Kadowaki, Ryozo Nagai, Kazunari Taira
    RNA Interference Technology: From Basic Science to Drug Development 480 - 496 2005年01月 [査読有り][通常論文]
     
    Introduction The success of the Human Genome Project and the availability of the complete sequence of the human genome have revealed the existence of numerous genes whose functions are unknown. Although many functional genes were successfully identified using libraries of randomized ribozymes (Kruger et al., 2000 Li et al., 2000 Welch et al., 2000 Beger et al., 2001 Kawasaki et al., 2002 Kawasaki and Taira, 2002 Onuki et al., 2002 Nelson et al., 2003 Rhoades and Wong-Staal, 2003 Suyama et al., 2003a, b Chatterton et al., 2004 Kuwabara et al., 2004 Onuki et al., 2004), the randomized library naturally contained many ribozymes that could not hybridize with any human gene transcripts, resulting in some false positives. While exploitation of RNA interference (RNAi) is hampered by the induction of the interferon response upon the introduction of double-stranded RNA (dsRNA) into mammalian cells (Elbashir et al., 2001), RNAi can be a powerful tool in gene analysis and, for example, the functions of a number of genes in the nematode Caenorhabditis elegans have been identified as being associated with particular mutant phenotypes (Fraser et al., 2000 Gonczy et al., 2000). Recent progress in mammalian cells, as discussed in this chapter, suggests that it should soon be possible to extend genome-wide approaches to mammalian cells, using libraries of small interfering RNA (siRNA) oligonucleotides or siRNA-expression libraries. Efforts to exploit the phenomenon of RNA interference (RNAi) in mammalian cells have been hampered by the interferon response in cells into which foreign RNA is introduced.
  • Yousuke Katsuda, Yoshiaki Takeshita, Ken Arima, Yutaka Saitoh, Tsutomu Imaizumi, Takayuki Asahara, Takeshi Nakatani, Teruo Okano, Akira Kishida, Hatsue Ishibashi-Ueda, Toshiharu Shin'Oka, Ryozo Nagai, Yoshiki Sawa, Masashi Komeda, Yoshiaki Takewa, Hikaru Matsuda, Hidezo Mori
    Cardiovascular Regeneration Therapies Using Tissue Engineering Approaches 183 - 189 2005年 [査読有り][通常論文]
     
    Background: Therapeutic angiogenesis by using cells is being performed in Japan. However, it is unknown in how many centers and how these therapies are performed. The efficacy and side effects are also unknown. Thus, we conducted the survey by mailing questionnaire within Japan. Methods and results: Two surveys were performed in 2003. The first survey unveiled that cell therapy was performed in 32 facilities until October 2003. The second survey unveiled the followings. (1) The total number of performed cases was 221. 153 patients (69.2%) had arterio-sclerosis obliterance (ASO), 56 patients (25.3%) thromboangitis obliterans (TAO, Burger's disease), and 12 patients (5.4%) other conditions. (2) The sources of cells were bone marrow-mononuclear cells (61.5%), peripheral-mononuclear cells (9.5%), and peripheral CD34+ cells (22.1%). A few patients (6.7%) were treated with a cytokine only (granulocyte-colony stimulating factor: G-CSF). (3) Inclusion criteria were the same for most facilities, such as patients with PAOD, especially with critical limb ischemia with rest pain, non-healing ischemic ulcers and non-candidates for non-surgical or surgical revascularization. All facilities excluded patients with histories of malignant disorder during the past 5 years, proliferative diabetic retinopathy, pregnancy, proliferative blood disease, uncontrolled ischemic heart disease, rheumatic arthritis, or psychiatric disease. (4) Subjective improvement was observed in 138 of 199 patients (69%). Objective improvements for ABI, TcO2 or angiographic findings were observed in 98 of 182 patients (53.8%). (6) Three of 221 patients (1.4%) died after cell therapy. One died from cerebro-vascular attack (thrombo-embolizm), and two died from acute myocardial infarction (AMI). Conclusion: Our clinical survey has shown that cell therapy is being performed in many medical centers in Japan. It seems to be safe and effective for patients with PAOD with no surgical options © 2005 Springer-Verlag Tokyo.
  • Masataka Sata, Ryozo Nagai
    Cardiovascular Regeneration Therapies Using Tissue Engineering Approaches 117 - 127 2005年 [査読有り][通常論文]
     
    Atherosclerosis is responsible for more than half of all deaths in western countries. Numerous studies have reported that exuberant accumulation of smooth muscle cells play a principal role in the pathogenesis of vascular diseases. It has been assumed that smooth muscle cells derived from the adjacent medial layer migrate, proliferate and synthesize extracellular matrix. Although much effort has been devoted, targeting migration and proliferation of medial smooth muscle cells, no effective therapy to prevent occlusive vascular remodeling has been established. Recently, we reported that bone marrow cells substantially contribute to the pathogenesis of vascular diseases, in models of post-angioplasty restenosis, graft vasculopathy and hyperlipidemia-induced atherosclerosis. It was suggested that bone marrow cells may have the potential to give rise to vascular progenitor cells that home in the damaged vessels and differentiate into smooth muscle cells or endothelial cells, thereby contributing to vascular repair, remodeling, and lesion formation. This article overviews recent findings on circulating vascular precursors and describes potential therapeutic strategies for vascular diseases, targeting mobilization, homing, differentiation and proliferation of circulating progenitor cells. © 2005 Springer-Verlag Tokyo.
  • Yokoyama, I, Y Inoue, T Moritan, K Ohtomo, R Nagai
    NUCLEAR MEDICINE COMMUNICATIONS 26 1 31 - 37 2005年01月 [査読有り][通常論文]
     
    Objective Skeletal muscle glucose utilization (SMGU) can be measured by F-18-FDG PET to characterize insulin resistance. The aim of this study was to determine whether femoral muscle SMGU can be measured without arterial blood sampling by sequential PET imaging of the thoracic and femoral regions. Methods Ten patients with possible insulin resistance underwent dynamic F-18-FDG PET of the femoral region during hyperinsulinaemic euglycaemic clamping (group A), and femoral muscle SMGU was calculated using PET data of various time periods and measured arterial input. SMGU was also calculated using venous plasma activity, instead of arterial activity, as input during the late phase. Another five patients underwent sequential PET of the thoracic and femoral regions after single tracer injection (group B). The input function was estimated from aorta activity on thoracic images during the early phase and from venous activity during the late phase, and SMGU with this estimated input was compared with that with measured arterial input. Results In group A, exclusion of early dynamic PET data from analysis had essentially no effect on the calculated SMGU, and partial substitution of venous activity for arterial activity only marginally changed the estimates. The difference between SMGUs with measured and estimated inputs was minimal in group B. Conclusion Femoral muscle SMGU can be calculated without femoral imaging early after tracer injection, and the input function can be assessed using data of thoracic imaging and venous blood samples. These results support the validity of measuring femoral muscle SMGU without arterial sampling, simultaneously with measurement of myocardial glucose utilization. (C) 2005 Lippincott Williams Wilkins.
  • N Ishizaka, Y Ishizaka, EI Toda, H Hashimoto, R Nagai, M Yamakado
    HYPERTENSION RESEARCH 28 1 27 - 34 2005年01月 [査読有り][通常論文]
     
    The cluster of metabolic and hemodynamic risk factors known as metabolic syndrome is known to be a risk factor for ischemic cardiovascular diseases and stroke. By analyzing the cross-sectional data from 8,144 individuals (age 19-88 years) who underwent general health screening, we have investigated the prevalence of metabolic syndrome, as diagnosed by modified-National Cholesterol Education Program (NCEP) criteria corresponding to the following five categories: triglycerides >= 150 mg/dl; high density lipoprotein (HDL)-cholesterol < 40 mg/dl in men or < 50 mg/dl in women; fasting plasma glucose >= 110 mg/dl; systolic/diastolic blood pressure >= 130/85 mmHg; and body mass index > 25 kg/m(2). We found that the prevalence of metabolic syndrome was 19% in men and 7% in women. After adjustment for age, metabolic syndrome was found to be significantly more prevalent in men than in women, with an odds ratio of 3.08 (95% confidence interval [CI] 2.62-3.61, p < 0.0001). Among the five metabolic/hemodynamic risk factor components, hypertension was observed most frequently in individuals with metabolic syndrome, at 85% in men and 87% in women. In addition, multivariate logistic regression analysis adjusted for age, sex, serum total cholesterol levels, and smoking status showed that hypertension possessed the greatest odds ratio (1.43, 95% CI 1.27-1.60) for carotid plaque among the metabolic/hemodynamic risk factors. These data emphasize the importance of controlling blood pressure for reducing the risk of both metabolic syndrome and carotid arteriosclerosis in apparently healthy individuals.
  • T Natori, M Sata, R Nagai, M Makuuchi
    BIOMEDICINE & PHARMACOTHERAPY 59 1-2 56 - 60 2005年01月 [査読有り][通常論文]
     
    Cimetidine, a histamine type-2 receptor antagonist, has been reported to improve survival of patients with cancers. However, the exact mechanisms by which cimetidine suppresses development of cancers remain to be elucidated. Solid tumors require neovascularization for their growth. Here, we investigated the effects of cimetidine on tumor growth and angiogenesis. Syngeneic colon cancer cells, CMT93 cells, were inoculated into the subcutaneous space of C57BL/6 mice. Mice were treated with either saline or cimetidine. Tumor size was measured everyday and angiogenesis was evaluated histologically. Cimetidine markedly suppressed tumor growth with reduced neovascularization in the tumor. Cimetidine had no effect on proliferation of CMT93 cells in vitro. Vascular endothelial growth factor production by cancer cells was not affected by cimetidine, while vascular-like tube formation by endothelial cells in vitro was significantly impaired in the presence of cimetidine. Our findings suggest that cimetidine suppresses tumor growth, at least in part, by inhibiting tumor-associated angiogenesis. (c) 2004 Elsevier SAS. All rights reserved.
  • Oishi Y, Manabe I, Tobe K, Tsushima K, Shindo T, Fujiu K, Nishimura G, Maemura K, Yamauchi T, Kubota N, Suzuki R, Kitamura T, Akira S, Kadowaki T, Nagai R
    Cell metabolism 1 1 27 - 39 2005年01月 [査読有り][通常論文]
     
    Krüppel-like factor 5 (KLF5) is a zinc-finger transcription factor known to play a pivotal role in the pathogenesis of cardiovascular disease. Here, we show that neonatal heterozygous KLF5 knockout mice exhibit a marked deficiency in white adipose tissue development, suggesting that KLF5 is also required for adipogenesis. In 3T3-L1 preadipocytes, KLF5 expression was induced at an early stage of differentiation, and this was followed by expression of PPARgamma2. Constitutive overexpression of dominant-negative KLF5 inhibited adipocyte differentiation, whereas overexpression of wild-type KLF5 induced differentiation even without hormonal stimulation. Moreover, embryonic fibroblasts obtained from KLF5+/- mice showed much attenuated adipocyte differentiation, confirming the key role played by KLF5 in adipocyte differentiation. KLF5 expression is induced by C/EBPbeta and delta. KLF5, in turn, acts in concert with C/EBPbeta/delta to activate the PPARgamma2 promoter. This study establishes KLF5 as a key component of the transcription factor network controlling adipocyte differentiation.
  • Ji Ma, Haruko Iida, Taisuke Jo, Haruhito Takano, Hitoshi Oonuma, Toshihiro Morita, Teruhiko Toyo-Oka, Masao Omata, Ryozo Nagai, Yukichi Okuda, Nobuhiro Yamada, Toshiaki Nakajima
    European journal of pharmacology 505 1-3 67 - 74 2004年11月 [査読有り][通常論文]
     
    Endothelin-1 is known to be implicated in the pathogenesis of hepatobiliary diseases such as cirrhosis, especially in portal hypertension. This study aimed to investigate the effects of ursodeoxycholic acid on endothelin-1 production in human endothelial cells. The effects of ursodeoxycholic acid and its conjugates (tauroursodeoxycholic and glycoursodeoxycholic acids) on endothelin-1 production as well as nitric oxide (NO) in human umbilical vein endothelial cells (HUVECs) were examined. The production of endothelin-1 and nitric oxide in culture medium was measured using enzyme-linked immunosorbent assay (ELISA) and the Griess method, respectively. Endothelin-1 and endothelial nitric oxide synthase (eNOS) mRNA expression were investigated by real-time quantitative reverse transcriptase/polymerase chain reaction (RT-PCR). Ursodeoxycholic acid (30-1000 microM) inhibited endothelin-1 production in a concentration-dependent manner, and ursodeoxycholic acid at concentrations higher than 300 microM increased nitric oxide production in culture medium. The conjugates of ursodeoxycholic acid also increased nitric oxide production and decreased endothelin-1 production, which was less effective than ursodeoxycholic acid. N-nitro-L-arginine-mythel-ester (L-NAME), a nitric oxide synthase (NOS) inhibitor, suppressed the ursodeoxycholic acid-induced nitric oxide production, but it did not antagonize the inhibitory effects of ursodeoxycholic acid on endothelin-1 production. Ursodeoxycholic acid also induced a concentration-dependent decrease in endothelin-1 mRNA expression without significant changes in eNOS mRNA expression. These results provide novel evidence that ursodeoxycholic acid inhibits endothelin-1 production in human endothelial cells, but nitric oxide is not responsible for the inhibitory effect of ursodeoxycholic acid on endothelin-1. Thus, ursodeoxycholic acid therapy may prevent the development of several pathogenesis such as portal hypertension observed in patients with cirrhosis due to the improvement of endothelial function.
  • Doubun Hayashi, Tsutomu Yamazaki, Ryozo Nagai
    Japanese Heart Journal 45 6 895 - 911 2004年11月 [査読有り][通常論文]
     
    Since there is in sufficient evidence on patients with coronary artery disease in Japan, the Japanese Coronary Artery Disease (JCAD) Study, in which 217 institutions participate, was designed to collect basic data based on evidence-based medicine (EBM). In this study, cardiac catheterization is performed on all cases to select study subjects confirmed as having CAD diagnosed based on the criteria that he or she has stenosis in at least one branch of a coronary artery to the extent of 75% or higher according to the AHA classification. Data including background information, risk factors, clinical management, and medication are to be collected over the web. The follow-up arm of the study consists of following each subject for three years to obtain data on the long-term prognosis of patients with CAD while the other arm is for enrolling new subjects every six months who will be followed for six months only for the purpose of determining the latest trend in patients. The two arms of the study have been ongoing since April 2000. As of September 30, 2003, 15,506 subjects have been enrolled in the follow-up arm and the follow-up data have been entered in the database. The authors plan to report data showing any correlation between incidence rate, focusing mainly on cerebrocardiovascular events, and other factors such as the management of risk factors, and type and dosage of medications obtained in the largest cohort ever studied in Japan of patients with a coronary artery lesion confirmed by cardiac catheterization.
  • Yasushi Fukushima, Toshimitsu Matsui, Toshihito Saitoh, Masao Ichinose, Keisuke Tateishi, Takayuki Shindo, Midori Fujishiro, Hideyuki Sakoda, Nobuhiro Shojima, Akifumi Kushiyama, Satoru Fukuda, Motonobu Anai, Hiraku Ono, Masashi Oka, Yasuhito Shimizu, Hiroki Kurihara, Ryozo Nagai, Takashi Ishikawa, Tomoichiro Asano, Masao Omata
    European journal of pharmacology 502 3 243 - 52 2004年10月 [査読有り][通常論文]
     
    Disruption of histamine H2 receptor and gastrin receptor had different effects growth of gastric mucosa: hypertrophy and atrophy, respectively. To clarify the roles of gastrin and histamine H2 receptors in gastric mucosa, mice deficient in both (double-null mice) were generated and analyzed. Double-null mice exhibited atrophy of gastric mucosae, marked hypergastrinemia and higher gastric pH than gastrin receptor-null mice, which were unresponsive even to carbachol. Comparison of gastric mucosae from 10-week-old wild-type, histamine H2 receptor-null, gastrin receptor-null and double-null mice revealed unique roles of these receptors in gastric mucosal homeostasis. While small parietal cells and increases in the number and mucin contents of mucous neck cells were secondary to impaired acid production, the histamine H2 receptor was responsible for chief cell maturation in terms of pepsinogen expression and type III mucin. In double-null and gastrin receptor-null mice, despite gastric mucosal atrophy, surface mucous cells were significantly increased, in contrast to gastrin-null mice. Thus, it is conceivable that gastrin-gene product(s) other than gastrin-17, in the stimulated state, may exert proliferative actions on surface mucous cells independently of the histamine H2 receptor. These findings provide evidence that different G-protein coupled-receptors affect differentiation into different cell lineages derived from common stem cells in gastric mucosa.
  • 武田 憲文, 永井 良三
    臨床高血圧 10 5 384 - 385 (株)メディカルレビュー社 2004年10月 [査読有り][通常論文]
  • S Sakurai, K Takenaka, Shiojima, I, M Sonoda, K Uno, K Nakahara, R Nagai
    ECHOCARDIOGRAPHY-A JOURNAL OF CARDIOVASCULAR ULTRASOUND AND ALLIED TECHNIQUES 21 7 573 - 579 2004年10月 [査読有り][通常論文]
     
    Paradoxical outward movement of left ventricular (LV) inferior wall in systole is occasionally recognized in normal subjects and clinically important in terms of the differential diagnosis between physiological pseudo-asynergy and pathological asynergy. In this study, the potential mechanisms by which pseudo-asynergy of LV inferior wall (PLI) is observed in normal subjects were investigated. PLI was defined as the outward movement of LV inferior wall observed during more than 50% of systole. The was evaluated in 7843 consecutive subjects in routine echocardiography. The effects of body position and artificial gravity on the manifestation of PLI were also examined. PLI was observed in 0.11% (9 / 7842) of subjects on left lateral position. Measurement of the angle formed by LV long-axis and the long-axis of the body on frontal plane revealed that hearts in subjects with PLI were in relatively horizontal position. PLI was observed on sitting position in 43% (40/92) of subjects without PLI on left lateral position. The subjects with sitting position-induced PLI exhibited significantly higher obesity index. PLI was also PLI in routine echocardiography is relatively low, PLI can be induced in normal subjects by any condition that causes close contact of LV inferior wall to diaphragm. Thus, PLI should be taken into consideration in the differential diagnosis of abnormal LV inferior wall motion, especially when performing exercise echocardiography.
  • T Ogata, M Kurabayashi, T Maeno, Y Maeno, S Ishikawa, I Takeyoshi, Y Morishita, R Nagai
    The Journal of cardiovascular surgery 45 5 497 - 500 2004年10月 [査読有り][通常論文]
     
    AIM: Vascular intimal hyperplasia is an important clinical concern in vascular diseases, such as anastomotic stricture as a possible complication of cardiovascular surgery. We recently suggested that a rat aortotomy model could be substituted for a vascular anastomotic stricture around a suture line. TNP-470 is known as an angiogenesis inhibitor and has demonstrated abilities to inhibit DNA synthesis of smooth muscle cells (SMCs) and SMCs proliferation. The aim of this study was to investigate the effect of TNP-470 on SMC proliferation using rat aortotomy models. METHODS: Longitudinal aortotomy was performed in the abdominal aorta of rats. Rats received a subcutaneous injection of materials (TNP-470, 20 mg/kg) or vehicle 3 times a week (n=10 in each group). The aorta was harvested 2 weeks after aortotomy. Serial sections from tissues were stained with hematoxylin and eosin, and the ratio of intimal to medial cross-sectional areas (I/M ratio) was determined. Values are expressed as the mean +/- the standard deviation. Results. Thickening of the intimal layer 2 weeks following aortotomy was observed in the control group however, intimal thickening was inhibited in the TNP-treated group. The I/M ratio was significantly (p = 0.0376) lower in the TNP-treated group than in the control group (8.3 +/- 4.8 vs 15.6 +/- 9.6%). Conclusion. TNP-470 significantly suppressed intimal thickening in experimental rat aortotomy models. TNP-470 might inhibit the development of anastomotic stricture after cardiovascular surgery.
  • H Fujimoto, M Ohno, S Ayabe, H Kobayashi, N Ishizaka, H Kimura, K Yoshida, R Nagai
    ARTERIOSCLEROSIS THROMBOSIS AND VASCULAR BIOLOGY 24 10 1848 - 1853 2004年10月 [査読有り][通常論文]
     
    Background - Carbon monoxide (CO) is postulated to protect tissues against several types of injuries. We investigated the role of CO in amelioration of cardiac ischemia - reperfusion injury in vivo and the mechanisms involved in it. Methods and Results - Rats inhaled CO ( 250 ppm, 500 ppm, or 1000 ppm) for 24 hours in a chamber after myocardial ischemia - reperfusion induced by occluding the left anterior descending coronary artery for 30 minutes. Pre-exposure to 1000 ppm of CO significantly reduced the ratio of infarct areas to risk areas and suppressed the migration of macrophages and monocytes into infarct areas, and the expression of tumor necrosis factor (TNF)-alpha in the heart; however, 250 ppm, 500 ppm of CO, or low barometric pressure hypoxia (0.5 atm) did not affect them. Exposure to 1000 ppm CO resulted in the activation of p38 mitogen-activated protein kinase (p38MAPK), protein kinase Balpha(Akt), endothelial nitric oxide synthase ( eNOS), and cyclic guanosine monophosphate ( cGMP) in the myocardium. Inhibition of p38MAPK, PI3kinase, NO, and soluble guanylate cyclase with SB203580, wortmannin, N(G)-nitro-L-arginine methyl ester (L-NAME), and methylene blue, respectively, attenuated the cytoprotection by CO. Conclusion - CO has beneficial effects on cardiac ischemia - reperfusion injury; this effect is mediated by p38MAPK pathway and Akt - eNOS pathway, including production of cGMP.
  • A Saiura, M Sata, K Hiasa, S Kitamoto, M Washida, K Egashira, R Nagai, M Makuuchi
    ARTERIOSCLEROSIS THROMBOSIS AND VASCULAR BIOLOGY 24 10 1886 - 1890 2004年10月 [査読有り][通常論文]
     
    Objective - Accelerated coronary arteriosclerosis remains a major problem in the long-term survival of cardiac transplant recipients. However, the pathogenesis of graft vasculopathy is poorly understood, and there is no effective therapy. Transplant arteriosclerosis is characterized by early mononuclear cell attachment on the transplanted vessel followed by development of concentric neointimal hyperplasia. Early and persistent expression of monocyte chemoattractant protein-1 (MCP-1) in cardiac allografts has been implicated for the pathogenesis of transplant arteriosclerosis. Methods and Results - We investigated whether anti-MCP-1 gene therapy can inhibit the development of intima hyperplasia in a mouse model of cardiac transplantation. Either the dominant-negative form of MCP-1 (7ND) or control vector was transfected into the skeletal muscles of B10.D2 mice. Cardiac allografts from DBA/2 mice were transplanted heterotopically into B10.D2 mice. 7ND gene transfer was associated with a significant reduction of the number of mononuclear cells accumulating in the lumen of the graft coronary arteries at 1 week and an attenuation of the development of the lesion at 8 weeks (intima/media ratio 0.79 +/- 0.05 versus 0.48 +/- 0.04). Conclusions - The MCP-1/chemokine receptor 2 (CCR2) signaling pathway plays a critical role in the pathogenesis of graft vasculopathy. This new anti-MCP-1 gene therapy might be useful to treat graft vascular disease.
  • Naoto Kubota, Yasuo Terauchi, Kazuyuki Tobe, Wataru Yano, Ryo Suzuki, Kohjiro Ueki, Iseki Takamoto, Hidemi Satoh, Toshiyuki Maki, Tetsuya Kubota, Masao Moroi, Miki Okada-Iwabu, Osamu Ezaki, Ryozo Nagai, Yoichi Ueta, Takashi Kadowaki, Tetsuo Noda
    The Journal of clinical investigation 114 7 917 - 27 2004年10月 [査読有り][通常論文]
     
    We previously demonstrated that insulin receptor substrate 2 (Irs2) KO mice develop diabetes associated with hepatic insulin resistance, lack of compensatory beta cell hyperplasia, and leptin resistance. To more precisely determine the roles of Irs2 in beta cells and the hypothalamus, we generated beta cell-specific Irs2 KO and hypothalamus-specific Irs2 knockdown (betaHT-IRS2) mice. Expression of Irs2 mRNA was reduced by approximately 90% in pancreatic islets and was markedly reduced in the arcuate nucleus of the hypothalamus. By contrast, Irs2 expression in liver, muscle, and adipose tissue of betaHT-IRS2 mice was indistinguishable from that of control mice. The betaHT-IRS2 mice displayed obesity and leptin resistance. At 4 weeks of age, the betaHT-IRS2 mice showed normal insulin sensitivity, but at 8 and 12 weeks, they were insulin resistant with progressive obesity. Despite their normal insulin sensitivity at 8 weeks with caloric restriction, the betaHT-IRS2 mice exhibited glucose intolerance and impaired glucose-induced insulin secretion. beta Cell mass and beta cell proliferation in the betaHT-IRS2 mice were reduced significantly at 8 and 12 weeks but not at 10 days. Insulin secretion, normalized by cell number per islet, was significantly increased at high glucose concentrations in the betaHT-IRS2 mice. We conclude that, in beta cells and the hypothalamus, Irs2 is crucially involved in the regulation of beta cell mass and leptin sensitivity.
  • Doubun Hayashi, Sumiyo Kudoh, Ichiro Shiojima, Yunzeng Zou, Koichiro Harada, Masaki Shimoyama, Yasushi Imai, Koshiro Monzen, Tsutomu Yamazaki, Yoshio Yazaki, Ryozo Nagai, Issei Komuro
    Biochemical and biophysical research communications 322 1 310 - 9 2004年09月 [査読有り][通常論文]
     
    Cardiac hypertrophy is formed in response to hemodynamic overload. Although a variety of factors such as catecholamines, angiotensin II (AngII), and endothelin-1 (ET-1) have been reported to induce cardiac hypertrophy, little is known regarding the factors that inhibit the development of cardiac hypertrophy. Production of atrial natriuretic peptide (ANP) is increased in the hypertrophied heart and ANP has recently been reported to inhibit the growth of various cell types. We therefore examined whether ANP inhibits the development of cardiac hypertrophy. Pretreatment of cultured cardiomyocytes with ANP inhibited the AngII- or ET-1-induced increase in the cell size and the protein synthesis. ANP also inhibited the AngII- or ET-1-induced hypertrophic responses such as activation of mitogen-activated protein kinase (MAPK) and induction of immediate early response genes and fetal type genes. To determine how ANP inhibits cardiomyocyte hypertrophy, we examined the mechanism of ANP-induced suppression of the MAPK activation. ANP strongly induced expression of MAPK phosphatase-1 (MKP-1) and overexpression of MKP-1 inhibited AngII- or ET-1-induced hypertrophic responses. These growth-inhibitory actions of ANP were mimicked by a cyclic GMP analog 8-bromo-cyclic GMP. Taken together, ANP directly inhibits the growth factor-induced cardiomyocyte hypertrophy at least partly via induction of MKP-1. Our present study suggests that the formation of cardiac hypertrophy is regulated not only by positive but by negative factors in response to hemodynamic load.
  • Masayoshi Kato, Akihiro Matsumoto, Toshiaki Nakajima, Ken Hirose, Kuniaki Iwasawa, Katsu Takenaka, Hiroshi Yamashita, Seiryo Sugiura, Yasunobu Hirata, Ryozo Nagai
    American journal of hypertension 17 9 729 - 33 2004年09月 [査読有り][通常論文]
     
    BACKGROUND: Endothelial production of nitric oxide (NO) is attenuated in patients with essential hypertension. We investigated whether treatment with amlodipine increased exhaled NO output (VNO) at rest and during exercise in patients with essential hypertension. METHODS: We studied the effect of amlodipine in seven untreated hypertensive patients. Cardiopulmonary exercise testing and NO measurement of exhaled air were performed on these patients before and after 2 months of amlodipine treatment. RESULTS: Amlodipine decreased blood pressure (BP) both at rest and during exercise (at rest: 147.1 +/- 6.4 [SEM]/89.9 +/- 4.4 v 133.6 +/- 5.4/82.7 +/- 3.9 mm Hg, P <.05; at peak exercise: 224.9 +/- 8.0/113.1 +/- 5.3 v 207.0 +/- 6.0/100.7 +/- 5.0 mm Hg, P <.05) without affecting heart rate (at rest: 67.6 +/- 3.9 v 70.4 +/- 4.5 beats/min, P =.33; peak exercise: 146.4 +/- 7.4 v 144.0 +/- 7.2 beats/min, P =.49). Amlodipine did not affect minute ventilation (VE) at rest or during exercise. It did not alter anaerobic threshold, peak oxygen uptake (peak VO(2)), or peak workload. However, after amlodipine treatment, VNO was significantly greater both at rest (130.8 +/- 19.4 v 180.4 +/- 24.8 nL/min, P <.05) and at peak exercise (380.0 +/- 47.5 v 582.6 +/- 74.3 nL/min, P <.05). CONCLUSIONS: Amlodipine increased NO production, at least in the pulmonary circulation, in patients with essential hypertension. In addition to its antihypertensive effect, the enhancement of NO production by amlodipine in the vasculature of other organs may contribute to its beneficial effects on the cardiovascular system.
  • Satoshi Iimuro, Takayuki Shindo, Nobuo Moriyama, Toshihiro Amaki, Pei Niu, Norifumi Takeda, Hiroshi Iwata, Yuelan Zhang, Aya Ebihara, Ryozo Nagai
    Circulation research 95 4 415 - 23 2004年08月 [査読有り][通常論文]
     
    Adrenomedullin (AM) is a novel vasodilating peptide involved in the regulation of circulatory homeostasis and implicated in the pathophysiology of cardiovascular disease. We tested the hypothesis that AM also possesses angiogenic properties. Using laser Doppler perfusion imaging, we found that AM stimulated recovery of blood flow to the affected limb in the mouse hind-limb ischemia model. AM exerted this effect in part by promoting expression of vascular endothelial growth factor (VEGF) in the ischemic limb, and immunostaining for CD31 showed the enhanced flow to reflect increased collateral capillary density. By enhancing tumor angiogenesis, AM also promoted the growth of subcutaneously transplanted sarcoma 180 tumor cells. However, heterozygotic AM knockout mice (AM+/-) showed significantly less blood flow recovery with less collateral capillary development and VEGF expression than their wild-type littermates. Similarly, mice treated with AM22-52, a competitive inhibitor of AM, showed reduced capillary development, and growth of sarcoma 180 tumors was inhibited in AM+/- and AM22-52-treated mice. Notably, administration of VEGF or AM rescued blood flow recovery and capillary formation in AM+/- and AM22-52-treated mice. In cocultures of endothelial cells and fibroblasts, AM enhanced VEGF-induced capillary formation, whereas in cultures of endothelial cells AM enhanced VEGF-induced Akt activation. These results show that AM possesses novel angiogenic properties mediated by its ability to enhance VEGF expression and Akt activity. This may make AM a useful therapeutic tool for relieving ischemia; conversely, inhibitors of AM could be useful for clinical management of tumor growth.
  • Hidenori Hamaguchi, Katsumi Fujimoto, Takeshi Kawamoto, Mitsuhide Noshiro, Koji Maemura, Norihiko Takeda, Ryozo Nagai, Masae Furukawa, Sato Honma, Ken-Ichi Honma, Hidemi Kurihara, Yukio Kato
    Biochemical Journal 382 1 43 - 50 2004年08月 [査読有り][通常論文]
     
    Dec2, a member of the basic helix-loop-helix superfamily, is a recently confirmed regulatory protein for the clockwork system. Transcripts of Dec2, as well as those of its related gene Dec1, exhibit a striking circadian oscillation in the suprachiasmatic nucleus, and Dec2 inhibits transcription from the Per1 promoter induced by Clock/Bmal1 [Honma, Kawamoto, Takagi, Fujimoto, Sato, Noshiro, Kato and Honma (2002) Nature (London) 419, 841-844]. It is known that mammalian circadian rhythms are controlled by molecular clockwork systems based on negative-feedback loop(s), but the molecular mechanisms for the circadian regulation of Dec2 gene expression have not been clarified. We show here that transcription of the Dec2 gene is regulated by several clock molecules and a negative-feedback loop. Luciferase and gel retardation assays showed that expression of Dec2 was negatively regulated by binding of Dec2 or Dec1 to two CACGTG E-boxes in the Dec2 promoter. Forced expression of Clock/Bmal1 and Clock/Bmal2 markedly increased Dec2 mRNA levels, and upregulated the transcription of the Dec2 gene through the CACGTG E-boxes. Like Dec, Cry and Per also suppressed Clock/Bmal-induced transcription from the Dec2 promoter. Moreover, the circadian expression of Dec2 transcripts was abolished in the kidney of Clock/Clock mutant mice. These findings suggest that the Clock/Bmal heterodimer enhances Dec2 transcription via the CACGTG E-boxes, whereas the induced transcription is suppressed by Dec2, which therefore must contribute to its own rhythmic expression. In addition, Cry and Per may also modulate Dec2 transcription.
  • Tokuyuki Yamashita, Kazuhiro Eto, Yukiko Okazaki, Shigeo Yamashita, Toshimasa Yamauchi, Nobuo Sekine, Ryozo Nagai, Mitsuhiko Noda, Takashi Kadowaki
    Endocrinology 145 8 3566 - 77 2004年08月 [査読有り][通常論文]
     
    Triglyceride (TG) accumulation in pancreatic beta-cells is thought to be associated with impaired insulin secretory response to glucose (lipotoxicity). To better understand the mechanism of the impaired insulin secretory response to glucose in beta-cell lipotoxicity, we overexpressed a constitutively active form of the sterol regulatory element-binding protein- 1c (SREBP-1c), a master transcriptional factor of lipogenesis, in INS-1 cells with an adenoviral vector. This treatment was associated with strong activation of transcription of the genes involved in fatty acid biosynthesis, increased cellular TG content, severely blunted glucose-stimulated insulin secretion, and enhanced expression of the uncoupling protein-2 (UCP-2), which supposedly dissipates the mitochondrial electrochemical potential. To decrease the up-regulated UCP-2 expression, small interfering RNA for UCP-2 was used. Introduction of the small interfering RNA increased the ATP/ADP ratio and partially rescued the glucose-stimulated insulin secretion in the cells overexpressing SREBP-1c, but did not affect the cellular TG content. Next, the effect of the AMP-activated protein kinase (AMPK) agonist, 5-amino-4-imidazolecarboxamide riboside, was examined in the lipotoxicity model. Exposure of the cells with lipotoxicity to 5-amino-4-imidazolecarboxamide riboside increased free fatty acid oxidation, partially reversed the TG accumulation, phosphorylated AMPK and acetyl-coenzyme A carboxylase, and improved the impaired glucose-stimulated insulin secretion. These results suggest that UCP-2 down-regulation and AMPK activation could be candidate targets for releasing beta-cells from lipotoxicity.
  • K Saito, N Ishizaka, T Aizawa, M Sata, N Iso-O, E Noiri, M Ohno, R Nagai
    HYPERTENSION RESEARCH 27 8 599 - 607 2004年08月 [査読有り][通常論文]
     
    We have previously shown that abnormal iron metabolism might be one underlying mechanism of the renal damage observed in the angiotensin II-infused rat. Transforming growth factor-beta1 (TGF-beta1) is known to play a crucial role in the development of renal damage induced by activation of the renin-angiotensin-aldosterone system. The purpose of the present study was to examine the effects of an iron chelator and a free radical scavenger on the angiotensin II-induced upregulation of TGF-beta1 in the kidney. Rats were given angiotensin II (0.7 mg/kg/day) via osmotic minipumps for 7 days. The expressions of the mRNAs of TGF-beta1 and collagen types I and IV were significantly increased in response to angiotensin II treatment. Histologic analysis showed that TGF-beta1 expression was upregulated mainly in tubular epithelial cells, and occasionally in glomerular and perivascular cells, some of which were identified as monocytes and/or macrophages. Although tubular cells that overexpressed TGF-beta1 did not contain iron particles, angiotensin II-induced TGF-beta1 upregulation was suppressed by the iron chelator and the free radical scavenger. The free radical scavenger also suppressed angiotensin II-induced upregulation of heme oxygenase-1, an oxidative-stress sensitive gene. By contrast, administration of iron dextran to rats induced upregulation of TGF-beta1 mRNA. Collectively, these data suggest that the renal iron overload and presumed subsequent increase in oxidative stress play a role in angiotensin II-induced upregulation of the mRNAs of TGF-beta1 and collagen types I and IV in the kidney.
  • Norihiko Takeda, Koji Maemura, Yasushi Imai, Tomohiro Harada, Daiji Kawanami, Takefumi Nojiri, Ichiro Manabe, Ryozo Nagai
    Circulation research 95 2 146 - 53 2004年07月 [査読有り][通常論文]
     
    Endothelial PAS domain protein 1 (EPAS1) is a basic-helix-loop-helix/PAS domain transcription factor that is expressed preferentially in vascular endothelial cells. EPAS1 shares high homology with hypoxia-inducible factor-1alpha (HIF-1alpha) and is reported to transactivate vascular endothelial growth factor (VEGF), fetal liver kinase-1 (Flk-1), and Tie2 promoters. In this study, we analyzed the role of EPAS1 in the process of angiogenesis. Using microarray technology, we looked for target genes regulated by EPAS1 in vascular endothelial cells. A total of 130 genes were upregulated by EPAS1, including fms-like tyrosine kinase-1 (Flt-1). Reporter analysis using human Flt-1 promoter and gel mobility shift assays showed that the heterodimer of EPAS1 and aryl hydrocarbon receptor nuclear translocator binds directly to HIF-1-binding site upstream of Flt-1 promoter and transactivates it. Small interfering RNA targeted to EPAS1 but not HIF-1alpha attenuated desferrioxamine-induced Flt-1 mRNA expression, thus EPAS1 is thought to play an essential role in hypoxic induction of Flt-1 gene. Furthermore, using mouse wound healing models, we demonstrated that adenovirus-mediated delivery of EPAS1 gene significantly induced the expression of VEGF, Flt-1, Flk-1, and Tie2 mRNA at the wound site and promoted mature angiogenesis. The proportion of the number of mural cells in newly formed vessels was significantly higher in EPAS1-treated wound area than VEGF-treated area. In conclusion, EPAS1 promotes Flt-1 gene expression and induces mRNA expression of VEGF, Flk-1, and Tie2, leading to enhancement of mature angiogenesis in vivo. Thus, EPAS1 may contribute to the construction of mature vessels by modulating the coordinated expressions of VEGF, Flt-1, Flk-1, and Tie2.