研究者業績

永井 良三

ナガイ リョウゾウ  (Ryozo Nagai)

基本情報

所属
自治医科大学 自治医科大学 学長
学位
博士(医学)

J-GLOBAL ID
200901024033893870
researchmap会員ID
1000190318

受賞

 7

論文

 955
  • 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
    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
    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
    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
    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
    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 &gt 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.
  • 相澤 玲, 牧 尚孝, 嵯峨 亜希子, 假屋 太郎, 神崎 綱, 稲葉 俊郎, 細谷 弓子, 高橋 政夫, 澤城 大悟, 藤生 克仁, 岩田 洋, 今井 靖, 藤田 英雄, 安東 治郎, 安喰 恒輔, 原田 和昌, 五條 理志, 永井 良三
    ICUとCCU 34(10) 884-888 2010年10月  
    症例は79歳男性。72歳時3枝病変を認めるも保存的加療となった。2009年労作時胸痛が出現、冠動脈病変の進行と心機能低下を認め、前下行枝に対しバイパス術施行。術直後から持続性/非持続性心室頻拍(VT)が頻発、回旋枝へPCI施行後、Overdrive pacingとニフェカラント/ランジオロールの持続投与にても消失せず。薬物抵抗性のVTと判断、LVマッピング下に電気的焼灼術を2回施行。しかし敗血症を機にVT stormに至り、挿管管理下に再度pacingとニフェカラント/ランジオロール持続点滴を併用し、ICD植込み術を施行。アミオダロン+カルベジロール内服開始したが、点滴薬漸減するとVT出現するためソタロールを追加。以後VT消失したため前医に転院となった。虚血性心筋症の血行再建に伴う難治性VTに対し、アブレーションに加えアミオダロン/ソタロールの併用が奏効した症例を経験したので報告する。(著者抄録)
  • 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
    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
    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9月17日  査読有り
    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.
  • 荷見 映理子, 藤生 克仁, 真鍋 一郎, 永井 良三
    肥満研究 16(Suppl.) 149-149 2010年9月  
  • 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9月  査読有り
    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8月31日  査読有り
    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8月6日  査読有り
    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.
  • 荷見 映理子, 岩田 洋, 興梠 貴英, 安東 治郎, 澤城 大悟, 高橋 政夫, 藤田 英雄, 平田 恭信, 永井 良三
    日本心臓病学会誌 5(Suppl.I) 248-248 2010年8月  
  • 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 2010年8月  
  • 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 2010年8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8月  査読有り
    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.
  • 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 2010年8月  査読有り
  • 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8月  査読有り
    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7月  査読有り
    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7月  査読有り
    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.
  • 森田 啓行, 永井 良三
    日本内科学会雑誌 99(6) 1349-1355 2010年6月10日  
    チーム医療推進のひとつの方策として,Nurse Practitioner/Physician assistant(NP/PA)をはじめとする「新しい」医療職種導入に関して議論されることが多くなってきた.しかしながらNP/PAがどのように位置づけられ,いかなる役割分担の下,医療行為をおこなっているか,ということに関する正確な理解は浸透していない.そこで我々はNP/PA発祥の地である米国に赴き,実際にNP/PAの勤務実態を視察し,NP/PAや管理者,医療スタッフのインタビューをおこなった.紹介されたデータ・文献などに基づき,米国のNP/PA制度の実態に関して本稿にまとめ,若干の考察を加える.チーム医療を推進するにはNP/PA制度導入は有効な手段のひとつと考えられ,現場のニーズ,役割分担と責任を議論することは大いにあってよい.法律整備による裁量権と責任の明記,養成教育システム・資格試験の制定,医療従事者と国民の理解などが課題になる.<br>
  • 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6月  査読有り
    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6月  査読有り
    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5月  査読有り
    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5月  査読有り
    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4月9日  査読有り
    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.
  • 岡野 智子, 海老原 文, 竹中 克, 木村 公一, 宇野 漢成, 福田 延昭, 安藤 治郎, 藤田 英雄, 永井 良三, 矢冨 裕
    超音波医学 37(Suppl.) S311-S311 2010年4月  
  • 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4月  査読有り
    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4月  査読有り
    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3月2日  査読有り
    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.
  • 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 2010年3月  
  • 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3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3月  査読有り
    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3月  査読有り
    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3月  査読有り
    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.
  • 鈴木 亨, 澤城 大悟, 永井 良三
    日本内科学会雑誌 99(2) 269-274 2010年2月10日  
    大動脈瘤ならびに大動脈解離は成人でみられる代表的な大血管の疾患である.ともに急性発症するため,迅速な診断法の開発は急務である.本稿では,バイオマーカーによるこれら大血管疾患の診断法の研究開発の現状と今後の可能性について概説する.<br>
  • 目黒 健太郎, 目黒 美葉, 安田 智洋, 高橋 昇子, 高橋 政夫, 高野 治人, 森田 敏宏, 佐田 政隆, 平田 恭信, 永井 良三, 中島 敏明
    心臓リハビリテーション 15(1) 160-164 2010年2月  
    【背景】運動療法は、糖脂質代謝の改善や血管内皮機能の改善を通して心血管イベントを減少させると考えられているが、運動の違いによる内皮機能への影響の違いは明らかではない。今回我々は、運動の違いによるサイトカインおよび血管内皮前駆細胞(EPC)数の反応の違いについて調べた。【方法】健常男性11人(平均29.6±4.8歳)にエルゴメータによる症候限界心肺運動負荷試験(20Wランプ)、30分の持続運動(無酸素閾値の70%強度のエルゴメーター)を行い運動前、直後、1時間後にサイトカイン(VEGF、G-CSF、IL-6、MCP-1、Flt-3 ligand)、NOxおよびEPC数の測定をFluorescence-activated cell sorterを用いて測定した。【結果】EPC数は最大負荷運動で運動前に比し、運動直後に有意に増加(14.6±5.4vs.43.3±21.6/mL、p<0.05)したが、持続運動で変化はみられなかった。G-CSF、NOxは運動前後で変化はみられなかった。VEGFは最大負荷運動および持続運動ともに一時間後に有意に増加がみられた(p<0.05)。IL-6は最大負荷運動にて1時間後に有意な増加がみられ(p<0.05)、MCP-1は両群とも1時間後に有意な増加が認められた(p<0.01)。Flt-3 ligandは持続運動にて運動直後に有意な増加がみられたが(p<0.05)、最大負荷運動では1時間後に有意な低下がみられた(p<0.01)。【結論】最大負荷運動と30分の持続運動において各種サイトカインの増加とEPC数の増加との間には相関がみられず、運動時のEPC数の増加へ関与するサイトカインは明らかではなかった。EPC数は最大負荷運動にて増加し、運動の違いが内皮機能への影響に違いのある可能性が示唆された。(著者抄録)
  • 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 2010年2月  
  • Nobukazu Ishizaka, Yuko Ishizaka, Akiko Toda, Mizuki Tani, Kazuhiko Koike, Minoru Yamakado, Ryozo Nagai
    Journal of Rheumatology 37(2) 410-416 2010年2月  査読有り
    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 &lt -1.86) and the lowest %dUA quartile (%dUA &lt -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2月  査読有り
    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2月  査読有り
    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2月  査読有り
    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.
  • 松岡 理恵, 杉山 裕章, 佐原 真, 今井 靖, 平田 恭信, 永井 良三
    内科 105(1) 177-182 2010年1月  
    症例は64歳男性で、労作時息切れ・動悸を主訴に近医を受診、心エコーにて大動脈弁の疣贅付着と重度大動脈弁閉鎖不全症を指摘され、感染性心内膜炎(IE)疑いにて精査加療目的で入院となった。本症例は事前の抗菌薬投与歴はなく、血液培養陰性のIEの起因菌として血清抗体価測定(海外発注)によりB.quintanaに対する抗体価が強陽性と判明、GMに続きCTRX、DOXYを投与したが微熱と炎症所見の改善、疣腫退縮もみられなかった。第40病日に大動脈弁置換術を施行、摘出大動脈弁の病理組織学的所見から疣贅は石灰化を伴うフィブリン塊・線維芽細胞や細血管増生に加え好中球や組織球など非特異的細胞浸潤がみられ、Wegener肉腫を示唆する所見は認めなかった。術後経過は良好で6週間のCTRX静注・DOXY内服後に退院となった。本症例は最終的にB.quintanaによる亜急性心内膜炎と診断されたが、血液培養陰性に加え血管炎症状を随伴し抗核抗体・C-ANCA陽性を呈したため、ANCA関連血管炎との鑑別が問題な症例であった。
  • 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 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.<BR>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.<BR>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
  • Nobukazu Ishizaka, Yuko Ishizaka, Ei-Ichi Toda, Kazuhiko Koike, Minoru Yamakado, Ryozo Nagai
    Kidney and Blood Pressure Research 32(6) 421-427 2010年1月  査読有り
    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 &lt 0 and %dBMI &lt 0, age-adjusted %dBPs was significantly greater in those with both %dWC &lt 0 and %dBMI ≥0 however, it did not significantly differ in those with both %dWC ≥0 and %dBMI &lt 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
    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
    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 &gt;= 40 g per day, &gt;= 20 cigarettes per day further increased GGT levels. Alcohol consumption showed a U-shaped association with HOMA-IR. In contrast, smoking 20-39 and &gt;= 40 cigarettes per day increased HOMA-IR as compared with never smokers. An interaction between alcohol consumption and smoking was present for GGT (p&lt;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.

MISC

 1913

書籍等出版物

 21

共同研究・競争的資金等の研究課題

 91