研究者業績

市原 佐保子

イチハラ サホコ  (Sahoko Ichihara)

基本情報

所属
自治医科大学 医学部 環境予防医学講座 教授
学位
医学博士(名古屋大学)

J-GLOBAL ID
200901089139977563
researchmap会員ID
5000079149

外部リンク

論文

 160
  • Sahoko Ichihara, Yoshiji Yamada, Frank J Gonzalez, Tamie Nakajima, Toyoaki Murohara, Gaku Ichihara
    Biochemical and biophysical research communications 381(1) 44-9 2009年3月27日  査読有り
    We have investigated the effect of benzo[a]pyrene (B[a]P), a carcinogen of tobacco smoke and an agonist for the aryl hydrocarbon receptor (AHR), on hypoxia-induced angiogenesis. Ischemia was induced by femoral artery ligation in wild-type and AHR-null mice, and the animals were subjected to oral administration of B[a]P (125 mg/kg) once a week. Exposure to B[a]P up-regulated the expression of metallothionein in the ischemic hindlimb and markedly inhibited ischemia-induced angiogenesis in wild-type mice. The amounts of interleukin-6 and of vascular endothelial growth factor (VEGF) mRNA in the ischemic hindlimb of wild-type mice were reduced by exposure to B[a]P. These various effects of B[a]P were markedly attenuated in AHR-null mice. Our observations suggest that the loss of the inhibitory effect of B[a]P on ischemia-induced angiogenesis apparent in AHR-null mice may be attributable to maintenance of interleukin-6 expression and consequent promotion of angiogenesis through up-regulation of VEGF expression.
  • Yoshiji Yamada, Sahoko Ichihara, Tamotsu Nishida
    CURRENT PHARMACEUTICAL DESIGN 14(33) 3590-3600 2008年11月  査読有り
  • Ichihara Gaku, Li Weihua, Kobayashi Takahiro, Ding Xuncheng, Fujitani Yuji, Liu Ying, Wang Qiangyi, Cui Uka, Hata Natsumi, Ichihara Sahoko
    TOXICOLOGY LETTERS 180 S222 2008年10月5日  査読有り
  • Yoshiji Yamada, Norifumi Metoki, Hidemi Yoshida, Kei Satoh, Kimihiko Kato, Takeshi Hibino, Kiyoshi Yokoi, Sachiro Watanabe, Sahoko Ichihara, Yukitoshi Aoyagi, Akitomo Yasunaga, Hyuntae Park, Masashi Tanaka, Yoshinori Nozawa
    Stroke 39(8) 2211-8 2008年8月  査読有り
    BACKGROUND AND PURPOSE: Although genetic epidemiologic studies have implicated several genetic variants as risk factors for ischemic or hemorrhagic stroke, the genetic determinants of these conditions remain largely unknown. We performed an association study to identify gene polymorphisms that confer susceptibility to atherothrombotic cerebral infarction, intracerebral hemorrhage, or subarachnoid hemorrhage. METHODS: The study population comprised 3432 unrelated Japanese individuals: 1362 stroke patients (822 with atherothrombotic cerebral infarction, 333 with intracerebral hemorrhage, and 207 with subarachnoid hemorrhage) and 2070 controls. The genotypes for 50 polymorphisms of 38 candidate genes were determined by a method that combines the polymerase chain reaction and sequence-specific oligonucleotide probes with suspension array technology. RESULTS: An initial chi(2) test (false discovery rate <0.05) and subsequent multivariable logistic-regression analysis with adjustment for conventional risk factors (P<0.05) revealed that the -14C-->T polymorphism (rs1800977) of ABCA1, the A-->C (rs3027898) and C-->T (Ser532Leu, rs1059703) polymorphisms of IRAK1, and the G-->C (Cys2229Ser) polymorphism (rs619203) of ROS1 were significantly associated with atherothrombotic cerebral infarction; that the -428G-->A polymorphism (rs710968) of LIMK1 was significantly associated with intracerebral hemorrhage; and that the 13989A-->G (Ile118Val) polymorphism (NC_000007.12) of CYP3A4 was significantly associated with subarachnoid hemorrhage. CONCLUSIONS: Genotypes for ABCA1, IRAK1, and ROS1 may prove useful for assessment of the genetic risk for atherothrombotic cerebral infarction, whereas those for LIMK1 and CYP3A4 may be similarly beneficial in assessment of the genetic risk for intracerebral hemorrhage and subarachnoid hemorrhage, respectively. Validation of these findings will require additional studies with independent subject panels.
  • Sahoko Ichihara, Yoshiji Yamada, Kimihiko Kato, Takeshi Hibino, Kiyoshi Yokoi, Hitoshi Matsuo, Tai Kojima, Sachiro Watanabe, Norifumi Metoki, Hidemi Yoshida, Kei Satoh, Yukitoshi Aoyagi, Akitomo Yasunaga, Hyuntae Park, Masashi Tanaka, Yoshinori Nozawa
    Genomics 91(6) 512-6 2008年6月  査読有り
    The aim of the present study was to identify gene polymorphisms that confer susceptibility to obesity. A total of 5448 unrelated Japanese individuals from two independent populations were examined: subject panel A comprised 4252 individuals who visited participating hospitals; subject panel B comprised 1196 community-dwelling elderly individuals. The genotypes for 95 polymorphisms of 67 candidate genes were determined. The chi(2) test revealed that six polymorphisms were related (p<0.05) to the prevalence of obesity in subject panel A; after application of Bonferroni's correction, however, only the 2677G --> A/T polymorphism (rs2032582) of the ATP-binding cassette, subfamily B, member 1 gene (ABCB1) was significantly associated (p=0.0003) with obesity. Subsequent multivariable logistic regression analysis also revealed that the 2677G --> A/T polymorphism of ABCB1 was significantly associated with obesity. For validation of this association, the 2677G --> A/T polymorphism of ABCB1 was examined in subject panel B and again found to be significantly associated with obesity. Body mass index was significantly (p=0.01) greater for individuals with the variant T allele of this polymorphism than for those with the GG genotype in the combined subject panels A and B. Our results suggest that the ABCB1 genotype may prove informative for assessment of genetic risk for obesity in Japanese individuals.
  • Yoshiji Yamada, Kimihiko Kato, Mitsutoshi Oguri, Tetsuro Yoshida, Kiyoshi Yokoi, Sachiro Watanabe, Norifumi Metoki, Hidemi Yoshida, Kei Satoh, Sahoko Ichihara, Yukitoshi Aoyagi, Akitomo Yasunaga, Hyuntae Park, Masashi Tanaka, Yoshinori Nozawa
    International journal of molecular medicine 21(6) 801-8 2008年6月  査読有り
    Metabolic syndrome is a risk factor for cardiovascular disease. The aim of the present study was to identify genetic variants that confer susceptibility to atherothrombotic cerebral infarction among individuals with metabolic syndrome in order to allow prediction of genetic risk for this condition. The study population comprised 1284 unrelated Japanese individuals with metabolic syndrome, including 313 subjects with atherothrombotic cerebral infarction and 971 controls. The genotypes for 296 polymorphisms of 202 candidate genes were determined with a method that combines the polymerase chain reaction and sequence-specific oligonucleotide probes with suspension array technology. The Chi-square test, multivariable logistic regression analysis with adjustment for age, sex, body mass index, and the prevalence of hypertension, hypercholesterolemia, and diabetes mellitus, as well as a stepwise forward selection procedure revealed that the 2445G-->A (Ala54Thr) polymorphism (rs1799883) of FABP2, the -108/3G-->4G polymorphism of IPF1 (S82168), the A-->G (Thr94Ala) polymorphism (rs2241883) of FABP1, the G-->A (Asp2213Asn) polymorphism (rs529038) of ROS1, the -11377C-->G polymorphism (rs266729) of ADIPOQ, the 162A-->C polymorphism (rs4769055) of ALOX5AP, the -786T-->C polymorphism (rs2070744) of NOS3, and the 3279C-->T polymorphism (rs7291467) of LGALS2 were associated (P<0.05) with the prevalence of atherothrombotic cerebral infarction. Among these polymorphisms, the 2445G-->A (Ala54Thr) polymorphism of FABP2 was most significantly associated with this condition. Our results suggest that FABP2, IPF1, FABP1, ROS1, ADIPOQ, ALOX5AP, NOS3, and LGALS2 are susceptibility loci for atherothrombotic cerebral infarction among Japanese individuals with metabolic syndrome. Genotypes for these polymorphisms, especially for the 2445G-->A (Ala54Thr) polymorphism of FABP2, may prove informative for the prediction of genetic risk for atherothrombotic cerebral infarction among such individuals.
  • Yamada Y, Ichihara S, Kato K, Yoshida T, Yokoi K, Matsuo H, Watanabe S, Metoki N, Yoshida H, Satoh K, Aoyagi Y, Yasunaga A, Park H, Tanaka M, Lee W, Nozawa Y
    Journal of Medical Genetics 45(4) 216-221 2008年  査読有り
  • Yamada Y, Kato K, Yoshida T, Yokoi K, Matsuo H, Watanabe S, Metoki N, Yoshida H, Satoh K, Ichihara S, Aoyagi Y, Yasunaga A, Park H, Tanaka M, Lee W, Nozawa Y
    Journal of Medical Genetics 45(1) 22-28 2008年  査読有り
  • Yoshiji Yamada, Kimihiko Kato, Tetsuro Yoshida, Kiyoshi Yokoi, Hitoshi Matsuo, Sachiro Watanabe, Sahoko Ichihara, Norifumi Metoki, Hidemi Yoshida, Kei Satoh, Yukitoshi Aoyagi, Akitomo Yasunaga, Hyuntae Park, Masashi Tanaka, Yoshinori Nozawa
    International journal of molecular medicine 21(1) 83-9 2008年1月  査読有り
    Although various environmental factors, such as a high-salt diet, a smoking habit, excessive alcohol intake, and physical inactivity, influence the development of hypertension, genetic variation also contributes to an individual's susceptibility to this condition. The purpose of the present study was to identify gene polymorphisms that confer susceptibility or resistance to hypertension, and thereby contribute to the prediction of the genetic risk for this condition. The study population comprised 2752 unrelated Japanese individuals (1370 men, 1382 women), including 1276 subjects with hypertension (774 men, 502 women) and 1476 controls (596 men, 880 women). The genotypes for 50 polymorphisms of 35 candidate genes were determined by a method that combines polymerase chain reaction and sequence-specific oligonucleotide probes with suspension array technology. Evaluation of genotype distributions by the Chi-square test and subsequent multivariable logistic regression analysis with adjustment for age, sex, body mass index, smoking status, and the prevalence of diabetes mellitus and hypercholesterolemia revealed that the -14C-->T polymorphism of ABCA1, the C-->G (Ser2229Cys) polymorphism of ROS1, the C-->T (Asn591Asn) polymorphism of LDLR, the 13989A-->G (Ile118Val) polymorphism of CYP3A4, the C-->G and A-->C polymorphisms of ADIPOR1, and the -519A-->G polymorphism of MMP1 were significantly (P<0.05) associated with the prevalence of hypertension. Systolic and diastolic blood pressure differed significantly among genotypes for the -14C-->T polymorphism of ABCA1 and the C-->G (Ser2229Cys) polymorphism of ROS1, with the variant T and G alleles, respectively, being related to increased blood pressure. These results suggest that polymorphisms of ABCA1 and ROS1 are determinants of blood pressure and the development of hypertension in Japanese individuals. Determination of genotypes for ABCA1 and ROS1 may thus prove informative for the prediction of the genetic risk for hypertension.
  • Yoshiji Yamada, Sahoko Ichihara, Tamotsu Nishida
    Genomic Medicine 2(1-2) 7-22 2008年1月  査読有り
  • Shameema Banu, Sahoko Ichihara, Fen Huang, Hidenori Ito, Yutaka Inaguma, Koichi Furuhashi, Yoshinobu Fukunaga, Qiangyi Wang, Junzoh Kitoh, Hisao Ando, Fumitaka Kikkawa, Gaku Ichihara
    Toxicological sciences : an official journal of the Society of Toxicology 100(2) 504-12 2007年12月  査読有り
    Previous experiments indicated that 1-bromopropane (1-BP), an alternative to chloroflurocarbons, is neurotoxic and inhibits spermiation in the testis. Here we investigated the reversibility of the toxic effects of 1-BP in rats. Male Wistar rats were divided into three equal groups of 24 each and exposed by inhalation to 0, 400 or 1000 ppm of 1-BP for 6 weeks (8 hrs/day, 7 days/week). Eight rats from each group were sacrificed at the end of 6 weeks exposure, and at 4 and 14 weeks after the end of exposure, to assess the recovery processes. We studied sperm count, motility, morphology and testicular histopathology, as well as blood pressure, skin temperature and hindlimb muscle strength. At the end of 6 weeks of exposure to 1000 ppm (0 week recovery), testicular weight, epididymal weight, sperm count and motility were low, morphologically abnormal sperm were increased and spermatogenic cells showed diffuse degeneration. These changes did not show full recovery at 14 weeks recovery, with the exception of the prostate and seminal vesicular weights, which recovered back to control values. At 400 ppm, increased retained spermatids at 0 week recovery returned to normal at 4 weeks recovery. Exposure to 1000 ppm produced sustained reduction of hindlimb muscle strength at 14 weeks recovery, whereas normalization of the skin temperature and blood pressure was noted after transient changes. Our study showed that the effect of 1-BP on spermatogenesis is dose-dependent; low exposure inhibited spermiation and hormone-dependent organ weight reduction and these changes were transient, while a higher dose of 1000 ppm 1-BP caused persistent depletion of spermatogenic cells.
  • Yoshiji Yamada, Hitoshi Matsuo, Sachiro Watanabe, Kimihiko Kato, Kazuhiro Yajima, Takeshi Hibino, Kiyoshi Yokoi, Sahoko Ichihara, Norifumi Metoki, Hidemi Yoshida, Kei Satoh, Yoshinori Nozawa
    INTERNATIONAL JOURNAL OF MOLECULAR MEDICINE 20(5) 703-707 2007年11月  査読有り
  • Yoshiji Yamada, Hitoshi Matsuo, Shunichiro Warita, Sachiro Watanabe, Kimihiko Kato, Mitsutoshi Oguri, Kiyoshi Yokoi, Norifumi Metoki, Hidemi Yoshida, Kei Satoh, Sahoko Ichihara, Yukitoshi Aoyagi, Akitomo Yasunaga, Hyuntae Park, Masashi Tanaka, Yoshinori Nozawa
    Genomics 90(5) 551-8 2007年11月  査読有り
    The purpose of the present study was to identify genetic variants that confer susceptibility to dyslipidemia. A total of 5213 individuals from two independent populations were examined: Subject panel A comprised 3794 individuals who visited participating hospitals; subject panel B comprised 1419 community-dwelling elderly individuals. The genotypes for 100 polymorphisms of 65 candidate genes were determined. The chi(2) test and multivariable logistic regression analysis revealed that seven polymorphisms of APOA5, APOC3, APOA1, ACAT2, and LPL were significantly associated with hypertriglyceridemia, six polymorphisms of APOA5, LIPC, and CYP3A4 with low HDL-cholesterol, and three polymorphisms of APOE and CCR2 with high LDL-cholesterol in subject panel A. For validation of these associations, the same polymorphisms were examined in subject panel B. Six polymorphisms of APOA5, APOC3, APOA1, and LPL were again significantly associated with hypertriglyceridemia, three polymorphisms of APOA5 with low HDL-cholesterol, and two polymorphisms of APOE with high LDL-cholesterol. Serum triglyceride, HDL-cholesterol, and LDL-cholesterol concentrations differed significantly among genotypes of these corresponding polymorphisms in both subject panels. These results indicate that polymorphisms of APOA5, APOC3, APOA1, and LPL are determinants of hypertriglyceridemia and that those of APOA5 and APOE are determinants of low HDL-cholesterol and high LDL-cholesterol, respectively, in Japanese individuals.
  • Aya Matsushita, Mitsunori Iwase, Yosuke Kato, Sahoko Ichihara, Gaku Ichihara, Hirotaka Kimata, Keiko Hayashi, Katsunori Hashimoto, Toyoharu Yokoi, Akiko Noda, Yasuo Koike, Mitsuhiro Yokota, Kohzo Nagata
    Experimental animals 56(5) 339-48 2007年10月  査読有り
    Sepsis is characterized by various symptoms, signs and underlying pathophysiology. To investigate possible mechanisms underlying this diversity, we compared the cardiovascular effects of lipopolysaccharide (LPS) derived from Escherichia coli (E-LPS) with those of LPS from Pseudomonas aeruginosa (P-LPS) in rats. We also examined the possible roles of tumor necrosis factor-alpha (TNF-alpha) and oxidative stress in LPS-induced cardiovascular damage. E-LPS (10 mg/kg body weight) or P-LPS (2 mg/kg body weight) was administered intravenously to Wistar rats. Echocardiography was serially performed. E-LPS induced an increase in left ventricular fractional shortening that persisted for at least 6 h, whereas P-LPS elicited an initial increase and a subsequent decrease in this parameter. Histological analysis revealed that P-LPS induced interstitial edema, congestion, intramyocardial bleeding, myocardial necrosis, infiltration of inflammatory cells, and formation of fibrin thrombi in the heart, whereas no pathological changes were apparent in the hearts of rats treated with E-LPS. Furthermore, the plasma concentration of TNF-alpha in rats treated with P-LPS was greater than that in rats treated with E-LPS, but the glutathione redox ratio in the heart was not affected by either type of LPS. In conclusion, E-LPS and P-LPS induced distinct patterns of functional and structural responses in the cardiovascular systems of rats. These differential responses may be attributable in part to the difference in the associated increases in the plasma concentration of TNF-alpha. The cardiovascular effects of LPS thus depend on the causative organisms.
  • Sahoko Ichihara, Yoshiji Yamada, Yoshichika Kawai, Toshihiko Osawa, Koichi Furuhashi, Zhiwen Duan, Gaku Ichihara
    Biochemical and biophysical research communications 359(1) 27-33 2007年7月20日  査読有り
    Cardiotoxicity is a treatment-limiting side effect of the anticancer drug doxorubicin (DOX). We have now investigated the roles of oxidative stress and signaling by the protein kinase Akt in DOX-induced cardiotoxicity as well as the effects on such toxicity both of fenofibrate, an agonist of peroxisome proliferator-activated receptor-alpha, and of polyethylene glycol-conjugated superoxide dismutase (PEG-SOD), an antioxidant. Mice injected intraperitoneally with DOX were treated for 4 days with fenofibrate or PEG-SOD. Fenofibrate and PEG-SOD each prevented the induction of cardiac dysfunction by DOX. Both drugs also inhibited the activation of the transcription factor NF-kappaB and increase in lipid peroxidation in the left ventricle induced by DOX, whereas only PEG-SOD inhibited the DOX-induced activation of Akt and Akt-regulated gene expression. These results suggest that fenofibrate and PEG-SOD prevented cardiac dysfunction induced by DOX through normalization of oxidative stress and redox-regulated NF-kappaB signaling.
  • Yamanoshita O, Ichihara S, Hama H, Ichihara G, Chiba M, Kamijima M, Takeda I, Nakajima T
    TOHOKU JOURNAL OF EXPERIMENTAL MEDICINE 212(2) 191-198 2007年6月5日  査読有り
  • Sahoko Ichihara, Yoshiji Yamada, Gaku Ichihara, Tamie Nakajima, Ping Li, Takahisa Kondo, Frank J Gonzalez, Toyoaki Murohara
    Arteriosclerosis, thrombosis, and vascular biology 27(6) 1297-304 2007年6月  査読有り
    OBJECTIVE: The aryl hydrocarbon receptor (AHR) is a transcription factor that binds to DNA as a heterodimer with the AHR nuclear translocator (ARNT) after interaction with ligands such as polycyclic and halogenated aromatic hydrocarbons found in tobacco smoke and the environment. We have investigated the interaction between AHR and hypoxia signaling pathways in regulation of angiogenesis with the use of a surgical model of ischemia. METHODS AND RESULTS: Ischemia was induced by femoral artery occlusion in wild-type and AHR-null mice. Ischemia-induced angiogenesis was markedly enhanced in AHR-null mice compared with that in wild-type animals. Ischemia-induced upregulation of the expression of hypoxia-inducible factor-1alpha (HIF-1alpha) and ARNT as well as that of target genes for these transcription factors, such as that for vascular endothelial growth factor (VEGF), were also enhanced in AHR-null mice. Furthermore, the DNA binding activity of the HIF-1alpha-ARNT complex as well as the association of HIF-1alpha and ARNT with the VEGF gene promoter were increased by ischemia to a greater extent in AHR-null mice than in wild-type animals. CONCLUSIONS: Ablation of AHR resulted in enhancement of ischemia-induced angiogenesis. This effect was likely attributable in part to the associated enhancement of ischemia-induced VEGF expression, which in turn may be caused by an increased abundance and activity of the HIF-1alpha-ARNT heterodimer.
  • Yoshiji Yamada, Kimihiko Kato, Takeshi Hibino, Kiyoshi Yokoi, Hitoshi Matsuo, Tomonori Segawa, Sachiro Watanabe, Sahoko Ichihara, Hidemi Yoshida, Kei Satoh, Yoshinori Nozawa
    ATHEROSCLEROSIS 191(2) 298-304 2007年4月  査読有り
  • Sachiyo Yamaguchi, Yoshiji Yamada, Hitoshi Matsuo, Tomonori Segawa, Sachiro Watanabe, Kimihiko Kato, Kiyoshi Yokoi, Sahoko Ichihara, Norifumi Metoki, Hidemi Yoshida, Kei Satoh, Yoshinori Nozawa
    INTERNATIONAL JOURNAL OF MOLECULAR MEDICINE 19(4) 631-637 2007年4月  査読有り
  • Shu Ichihara, Takuya Fujimoto, Katsunori Hashimoto, Suzuko Moritani, Masaki Hasegawa, Toyoharu Yokoi
    Pathology International 57(3) 126-132 2007年3月  
  • Kohta Nishihama, Yoshiji Yamada, Hitoshi Matsuo, Tomonori Segawa, Sachiro Watanabe, Kimihiko Kato, Kazuhiro Yajima, Takeshi Hibino, Kiyoshi Yokoi, Sahoko Ichihara, Norifumi Metoki, Hidemi Yoshida, Kei Satoh, Yoshinori Nozawa
    INTERNATIONAL JOURNAL OF MOLECULAR MEDICINE 19(1) 129-141 2007年1月  査読有り
  • Masako Saka, Koji Obata, Sahoko Ichihara, Xian Wu Cheng, Hirotaka Kimata, Akiko Noda, Hideo Izawa, Kohzo Nagata, Mitsuhiro Yokota
    CLINICAL AND EXPERIMENTAL PHARMACOLOGY AND PHYSIOLOGY 33(12) 1164-1171 2006年12月  査読有り
  • Sahoko Ichihara, Yoshiji Yamada, Gaku Ichihara, Hiroaki Kanazawa, Katsunori Hashimoto, Yosuke Kato, Aya Matsushita, Shinji Oikawa, Mitsuhiro Yokota, Mitsunori Iwase
    Biochemical and biophysical research communications 350(1) 105-13 2006年11月10日  査読有り
    Oxidative stress is an important susceptibility factor for dilated cardiomyopathy. We have investigated the effects of bisoprolol, a beta1-selective adrenoceptor blocker, on oxidative stress and the development of cardiac dysfunction in a model of dilated cardiomyopathy. Male TO-2 and control hamsters at 8 weeks of age were treated with bisoprolol (5 mg/kg per day) or vehicle for 4 weeks. Treatment with bisoprolol prevented the progression of cardiac dysfunction in TO-2 hamsters. This drug did not affect the increase in NADPH oxidase activity but prevented the reduction in activity and expression of mitochondrial manganese-dependent superoxide dismutase as well as the increases in the concentrations of interleukin-1beta and tumor necrosis factor-alpha in the left ventricle of TO-2 hamsters. Attenuation of the development of cardiac dysfunction by bisoprolol may thus result in part from normalization of the associated increases in the levels of oxidative stress and pro-inflammatory cytokines in the left ventricle.
  • Yoshiji Yamada, Kimihiko Kato, Takashi Kameyama, Kiyoshi Yokoi, Hitoshi Matsuo, Tomonori Segawa, Sachiro Watanabe, Sahoko Ichihara, Hidemi Yoshida, Kei Satoh, Yoshinori Nozawa
    INTERNATIONAL JOURNAL OF MOLECULAR MEDICINE 18(5) 843-851 2006年11月  査読有り
  • Sachiyo Yamaguchi, Yoshiji Yamada, Norifumi Metoki, Hidemi Yoshida, Kei Satoh, Sahoko Ichihara, Kimihiko Kato, Takashi Kameyama, Kiyoshi Yokoi, Hitoshi Matsuo, Tomonori Segawa, Sachiro Watanabe, Yoshinori Nozawa
    INTERNATIONAL JOURNAL OF MOLECULAR MEDICINE 18(5) 871-883 2006年11月  査読有り
  • Yoshiji Yamada, Hitoshi Matsuo, Tomonori Segawa, Sachiro Watanabe, Kimihiko Kato, Takeshi Hibino, Kiyoshi Yokoi, Sahoko Ichihara, Norifumi Metoki, Hidemi Yoshida, Kei Satoh, Yoshinori Nozawa
    AMERICAN JOURNAL OF HYPERTENSION 19(11) 1158-1165 2006年11月  査読有り
  • Yoshiji Yamada, Norifumi Metoki, Hidemi Yoshida, Kei Satoh, Sahoko Ichihara, Kimihiko Kato, Takashi Kameyama, Kiyoshi Yokoi, Hitoshi Matsuo, Tomonori Segawa, Sachiro Watanabe, Yoshinori Nozawa
    ARTERIOSCLEROSIS THROMBOSIS AND VASCULAR BIOLOGY 26(8) 1920-1925 2006年8月  査読有り
  • Sahoko Ichihara, Koji Obata, Yoshiji Yamada, Kohzo Nagata, Akiko Noda, Gaku Ichihara, Akira Yamada, Tomoko Kato, Hideo Izawa, Toyoaki Murohara, Mitsuhiro Yokota
    Journal of molecular and cellular cardiology 41(2) 318-29 2006年8月  査読有り
    Peroxisome proliferator-activated receptor-alpha (PPAR-alpha) is a key regulator of lipid and glucose metabolism and is implicated in inflammation. We investigated the effects of the PPAR-alpha activator fenofibrate on, as well as the role of redox-regulated transcription factors, in the development of left ventricular (LV) hypertrophy and heart failure in Dahl salt-sensitive (DS) rats. DS rats were fed a high-salt diet and treated with either fenofibrate (30 or 50 mg/kg per day) or vehicle from 7 weeks of age. Fenofibrate inhibited the development of compensated hypertensive LV hypertrophy, attenuated the LV relaxation abnormality and systolic dysfunction, and improved the survival rate in DS rats. It also prevented a decrease in the ratio of reduced to oxidized glutathione and inhibited up-regulation of the DNA binding activities of the redox-regulated transcription factors NF-kappaB, AP-1, Egr-1, SP1, and Ets-1 induced in the left ventricle by the high-salt diet. Expression of target genes for these transcription factors, including those for adhesion molecules (VCAM-1, ICAM-1), cytokines (MCP-1), growth factors (TGF-beta, PDGF-B), and osteopontin, was also increased by the high-salt diet in a manner sensitive to treatment with fenofibrate. Furthermore, the infiltration of macrophages and T lymphocytes into the left ventricle and the increase in the plasma concentration of C-reactive protein were inhibited by fenofibrate. The PPAR-alpha activator fenofibrate thus attenuated the progression of heart failure and improved the survival rate in this rat model. These effects were associated with inhibition of the inflammatory response and of activation of redox-regulated transcription factors in the left ventricle.
  • Yoshiji Yamada, Hitoshi Matsuo, Tomonori Segawa, Sachiro Watanabe, Kimihiko Kato, Takashi Kameyama, Kiyoshi Yokoi, Sahoko Ichihara, Norifumi Metoki, Hidemi Yoshida, Kei Satoh, Yoshinori Nozawa
    INTERNATIONAL JOURNAL OF MOLECULAR MEDICINE 18(2) 299-308 2006年8月  査読有り
  • Yoshiji Yamada, Hitoshi Matsuo, Tomonori Segawa, Sachiro Watanabe, Kimihiko Kato, Jakeshi Hibino, Kiyoshi Yokoi, Sahoko Ichihara, Norifumi Metoki, Hidemi Yoshida, Kei Satoh, Yoshinori Nozawa
    THROMBOSIS AND HAEMOSTASIS 96(2) 220-227 2006年8月  査読有り
  • Koichi Furuhashi, Junzoh Kitoh, Hiroko Tsukamura, Kei-Ichiro Maeda, Hailan Wang, Weihua Li, Sahoko Ichihara, Tamie Nakajima, Gaku Ichihara
    Toxicology 224(3) 219-28 2006年7月25日  査読有り
    1-Bromopropane (1-BP) exhibits neuroreproductive toxicities in adult rats and humans. Here, we determined the effects of exposure of rat dams to 1-BP during pregnancy and lactation on the growth and sexual maturation of their offspring. In Experiment 1, 40 rats were exposed to 0, 100, 400 and 800ppm 1-BP during pregnancy and lactation for 8h/day. Ten rats that were not placed in chambers throughout the experiment served to observe the effect of separation of dams from offspring. In Experiment 2, three groups of 10 pregnant rats each were exposed to fresh air in three chambers and 10 other rats were exposed to 800ppm 1-BP during pregnancy and lactation for 8h/day. After delivery, offspring of the exposed and non-exposed dams were swapped so that they were nursed by the opposite dams. In Experiment 1, the survival rate and body weight of offspring were lower than the non-exposed in 1-BP dose-dependent manner. In Experiment 2, the survival rate and body weight of offspring (Group A) nursed by exposed dams and those (Group B) of exposed dams were significantly lower than non-exposed groups. The body weight of Group A was lower than that of Group B, although the two groups showed a significant equal decrease in the survival rate. The number of dead offspring from Group A was significantly higher. Our results indicate that exposure to 1-BP during pregnancy and lactation has comparable effects on survival rate, but exposure during lactation has a more adverse effect on growth of offspring than that during pregnancy. Moreover, exposure during lactation is associated with reduced early survival of third generation (F2) rats.
  • Masako Saka, Koji Obata, Sahoko Ichihara, Xian Wu Cheng, Hirotaka Kimata, Takao Nishizawa, Akiko Noda, Hideo Izawa, Kohzo Nagata, Toyoaki Murohara, Mitsuhiro Yokota
    JOURNAL OF CARDIOVASCULAR PHARMACOLOGY 47(6) 770-779 2006年6月  査読有り
  • Nagata Kohzo, Obata Koji, Xu Jinglan, Ichihara Sahoko, Noda Akiko, Kimata Hirotaka, Kato Tomoko, Izawa Hideo, Murohara Toyoaki, Yokota Mitsuhiro
    Hypertension 47(4) 656-64 2006年4月  査読有り
    Chronic elevation of plasma aldosterone contributes to heart failure. Mineralocorticoid receptor (MR) antagonism is cardioprotective in such a setting, but whether such protection occurs in the presence of low-aldosteroneconcentrations remains unclear. Weinvestigated whether MR blockade attenuates cardiac hypertrophy and failure in rats with salt-sensitive hypertension. Dahl salt-sensitive (DS) rats fed a high-salt diet from 7 weeks develop concentric left ventricular (LV) hypertrophy secondary to hypertension at 12 weeks followed by heart failure at 19 weeks (DS-CHF). DS rats on such a diet were treated with a non-antihypertensive dose of the selective MR antagonist eplerenone from 12 to 19 weeks. Renin activity and aldosterone concentration in plasma were decreased in DS-CHF rats compared with controls. LV hypertrophy and fibrosis, as well as macrophage infiltration around coronary vessels, were apparent in DS-CHF rats. The amounts of mRNAs for 11beta-hydroxysteroid dehydrogenase type 1, MR, monocyte chemoattractant protein 1, and osteopontin were increased in these hearts. Treatment of DS-CHF rats with eplerenone inhibited these changes in gene expression, as well as coronary va
  • K Nagata, K Obata, JL Xu, S Ichihara, A Noda, H Kimata, T Kato, H Izawa, T Murohara, M Yokota
    HYPERTENSION 47(4) 656-664 2006年4月  査読有り
  • Sahoko Ichihara, Akiko Noda, Kohzo Nagata, Koji Obata, Jinglan Xu, Gaku Ichihara, Shinji Oikawa, Shosuke Kawanishi, Yoshiji Yamada, Mitsuhiro Yokota
    Cardiovascular research 69(3) 726-35 2006年2月15日  査読有り
    OBJECTIVES: Oxidative stress is implicated in the pathogenesis of heart failure and affects the activity of matrix metalloproteinases (MMPs). We have now investigated the role of MMPs and their tissue inhibitors (TIMPs) in the transition from compensated left ventricular (LV) hypertrophy to heart failure as well as the effects of pravastatin on this transition in a rat model. METHODS: Dahl salt-sensitive rats were fed a high-salt (8% NaCl) diet and treated with pravastatin (50 or 100 mg/kg per day) or vehicle from 7 weeks of age. RESULTS: Pravastatin did not attenuate LV hypertrophy apparent at 12 or 18 weeks of age. However, the high dose of this drug markedly improved indices of diastolic function (early diastolic myocardial velocity) and systolic function (LV fractional shortening) at 18 weeks of age and increased the survival rate. It also prevented a decrease in the ratio of reduced to oxidized glutathione and an increase in NADPH oxidase activity in the left ventricle induced by the high-salt diet. The activities of MMP2 and MMP9 and the abundance of TIMP1 and TIMP2 in LV tissue were increased at 18 weeks of age, and pravastatin also prevented these changes. CONCLUSION: Although pravastatin did not attenuate LV hypertrophy, it prevented the transition from compensated hypertrophy to heart failure in this rat model. This effect of pravastatin may result from a reduction both in the level of oxidative stress and in MMP activity in the heart.
  • Izawa Hideo, Murohara Toyoaki, Nagata Kohzo, Isobe Satoshi, Asano Hiroyuki, Amano Tetsuya, Ichihara Sahoko, Kato Tomoko, Ohshima Satoru, Murase Yosuke, Iino Shigeo, Obata Koji, Noda Akiko, Okumura Kenji, Yokota Mitsuhiro
    Circulation 112(19) 2940-5 2005年11月  査読有り
    Mineralocorticoid receptor antagonism reduces mortality associated with heart failure by mechanisms that remain unclear. The effects of the mineralocorticoid receptor antagonist spironolactone on left ventricular (LV) function and chamber stiffness associated with myocardial fibrosis were investigated in mildly symptomatic patients with idiopathic dilated cardiomyopathy (DCM).
  • H Izawa, T Murohara, K Nagata, S Isobe, H Asano, T Amano, S Ichihara, T Kato, S Ohshima, Y Murase, S Iino, K Obata, A Noda, K Okumura, M Yokota
    CIRCULATION 112(19) 2940-2945 2005年11月  査読有り
  • Xu Jinglan, Nagata Kohzo, Obata Koji, Ichihara Sahoko, Izawa Hideo, Noda Akiko, Nagasaka Tetsuro, Iwase Mitsunori, Naoe Tomoki, Murohara Toyoaki, Yokota Mitsuhiro
    Hypertension 46(4) 719-24 2005年10月  査読有り
    Long-term administration of vasodilators increases shear stress, which is thought to be important for vascular growth in the heart. Nicorandil, an activator of ATP-sensitive potassium channels with a nitrate-like action, is a potent vasodilator. We have now investigated the effects of nicorandil on vascular growth and gene expression in the failing heart of Dahl salt-sensitive (DS) hypertensive rats. DS rats fed a high-salt diet from 6 weeks of age develop concentric cardiac hypertrophy secondary to hypertension at 11 weeks, followed by heart failure at 18 weeks. DS rats on such a diet were treated with a nonantihypertensive oral dose of nicorandil (6 mg/kg per day) or vehicle from 11 to 18 weeks of age. Treatment of DS rats with nicorandil improved cardiac function and attenuated the development of heart failure. Myocardial capillary and arteriolar densities did not differ between vehicle-treated DS rats and age-matched controls. The abundance of mRNAs for endothelial NO synthase (eNOS), vascular endothelial growth factor (VEGF), the VEGF receptor Flt-1, and basic fibroblast growth factor (bFGF) in the myocardium was markedly reduced in vehicle-treated DS rats compared with contro
  • JL Xu, K Nagata, K Obata, S Ichihara, H Izawa, A Noda, T Nagasaka, M Iwase, T Naoe, T Murohara, M Yokota
    HYPERTENSION 46(4) 719-724 2005年10月  査読有り
  • Takao Nishizawa, Mitsunori Iwase, Hiroaki Kanazawa, Sahoko Ichihara, Gaku Ichihara, Kohzo Nagata, Koji Obata, Kiyoyuki Kitaichi, Toyoharu Yokoi, Masato Watanabe, Takashi Tsunematsu, Yoshihiro Ishikawa, Toyoaki Murohara, Mitsuhiro Yokota
    Circulation journal : official journal of the Japanese Circulation Society 68(11) 1051-60 2004年11月  査読有り
    BACKGROUND: The relationship between enhanced myocardial oxidative stress and impaired beta-adrenergic signaling remains to be characterized during the development of dilated cardiomyopathy. METHODS AND RESULTS: Alterations in myocardial oxidative stress and beta-adrenergic signaling, as well as left ventricular (LV) functional and structural changes, were evaluated during the development of cardiomyopathy in TO-2 hamsters; F1B hamsters served as controls. LV dysfunction was first apparent at 8 weeks of age and deteriorated thereafter in the TO-2 hamsters. At 32 weeks, the animals exhibited heart failure with an increased plasma norepinephrine concentration. Cardiac myolysis, as demonstrated by elevated plasma concentration of cardiac troponin T, peaked at 8 weeks. The glutathione redox ratio revealed increased oxidative stress in the LV myocardium in TO-2 hamsters even at 4 weeks and became manifest after 8 weeks. The hearts of TO-2 hamsters had significantly reduced superoxide dismutase activity from 8 weeks onward compared with control hamsters. However, glutathione peroxidase activity was unchanged at any time point. The LV functional response to isoproterenol was markedly reduced at 8 weeks, without any apparent changes in the amount of beta-adrenergic signaling molecules, and it deteriorated thereafter. Adenylyl cyclase activity was significantly decreased, despite increased amounts of both G(s) alpha mRNA and protein, in the LV myocardium at 18 weeks. CONCLUSIONS: Myocardial oxidative stress is actually enhanced in the initial development of LV dysfunction. Both activation of myocardial oxidative stress and impairment of beta-adrenergic signaling become prominent at the stage of severe LV dysfunction. Myocardial oxidative stress may be involved in the development of beta-adrenergic desensitization.
  • A Yamada, S Ichihara, Y Murase, T Kato, H Izawa, K Nagata, T Murohara, Y Yamada, M Yokota
    JOURNAL OF MOLECULAR MEDICINE-JMM 82(7) 477-483 2004年7月  査読有り
  • Y Murase, Y Yamada, A Hirashiki, S Ichihara, H Kanda, M Watarai, F Takatsu, T Murohara, M Yokota
    EUROPEAN HEART JOURNAL 25(11) 970-977 2004年6月  査読有り
  • H Horibe, Y Yamada, S Ichihara, M Watarai, M Yanase, K Takemoto, S Shimizu, H Izawa, F Takatsu, M Yokota
    ATHEROSCLEROSIS 174(1) 181-187 2004年5月  査読有り
  • Y Yamada, S Ichihara, H Izawa, M Tanaka, M Yokota
    MOLECULAR GENETICS AND METABOLISM 81(4) 282-290 2004年4月  査読有り
  • K Shimokata, Y Yamada, T Kondo, S Ichihara, H Izawa, K Nagata, T Murohara, M Ohno, M Yokota
    ATHEROSCLEROSIS 172(1) 167-173 2004年1月  査読有り
  • K Nagata, K Obata, M Odashima, A Yamada, F Somura, T Nishizawa, S Ichihara, H Izawa, M Iwase, A Hayakawa, T Murohara, M Yokota
    JOURNAL OF MOLECULAR AND CELLULAR CARDIOLOGY 35(12) 1505-1512 2003年12月  査読有り
  • Y Yamada, H Izawa, S Ichihara, F Takatsu, H Ishihara, H Hirayama, T Sone, M Tanaka, M Yokota
    NEW ENGLAND JOURNAL OF MEDICINE 347(24) 1916-1923 2002年12月  査読有り
  • S Ichihara, T Senbonmatsu, E Price, T Ichiki, FA Gaffney, T Inagami
    CIRCULATION 106(17) 2244-2249 2002年10月  査読有り
  • Nagata Kohzo, Somura Fuji, Obata Koji, Odashima Mari, Izawa Hideo, Ichihara Sahoko, Nagasaka Tetsuro, Iwase Mitsunori, Yamada Yoshiji, Nakashima Nobuo, Yokota Mitsuhiro
    Hypertension 40(2) 168-74 2002年8月  査読有り
    The possible role of calcineurin in the attenuation of cardiachypertrophy and fibrosis by blockade of the angiotensin II type 1 (AT1) receptor was investigated in Dahl salt-sensitive (DS) rats. The effect of the calcineurin inhibitor FK506 was also studied. DS rats progressively developed severe hypertension when fed a diet containing 8% NaCl from 7 weeks of age. In addition, marked cardiac hypertrophy and fibrosis were apparent and the activity of calcineurin and its mRNA expression in the myocardium was increased in these animals at 12 weeks in comparison with age-matched Dahl salt-resistant rats. The abundance of angiotensin-converting enzyme (ACE) and transforming growth factor (TGF)-beta1 mRNAs was also increased in the hearts of DS rats at 12 weeks. Treatment of DS rats with a non-antihypertensive dose of the selective AT1 receptor blocker candesartan (1 mg/kg per day) or FK506 (0.1 mg/kg per day) from 7 to 12 weeks attenuated both calcineurin activity and its mRNA expression in the heart, as well as the development of cardiac hypertrophy and fibrosis, without affecting cardiac function. Treatment with candesartan, but not FK506, prevented theupregulation of ACE and TGF-beta1
  • K Nagata, F Somura, K Obata, M Odashima, H Izawa, S Ichihara, T Nagasaka, M Iwase, Y Yamada, N Nakashima, M Yokota
    HYPERTENSION 40(2) 168-174 2002年8月  査読有り

MISC

 91

共同研究・競争的資金等の研究課題

 33