2024/02/01 更新

写真a

カミムラ ナオミ
上村 尚美
Naomi Kamimura
所属
医学部 臨床系研究室 准教授
職名
准教授
外部リンク

学位

  • 博士(医学) ( 東京大学 )

研究キーワード

  • ミトコンドリア

  • 炎症

  • 糖尿病

  • 酸化ストレス

研究分野

  • ライフサイエンス / 細胞生物学

経歴

  • 日本医科大学   共同研究施設 臨床系研究室   准教授

    2020年9月 - 現在

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  • 日本医科大学   先端医学研究所   准教授

    2013年4月 - 2020年8月

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  • 日本医科大学   先端医学研究所   講師

    2009年4月 - 2013年3月

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  • 日本医科大学   老人病研究所   助教

    2007年4月 - 2009年3月

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  • 日本医科大学   老人病研究所   助手

    2003年4月 - 2007年3月

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  • 日本医科大学   老人病研究所   博士研究員

    2001年4月 - 2003年3月

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  • 国立遺伝学研究所   COE講師

    1999年6月 - 2001年3月

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  • 大阪大学   微生物病研究所   助手

    1996年6月 - 1999年5月

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  • 日本学術振興会   特別研究員

    1996年4月 - 1996年5月

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▼全件表示

所属学協会

論文

  • Transgenic type2 diabetes mouse models for in vivo redox measurement of hepatic mitochondrial oxidative stress. 国際誌

    Naomi Kamimura, Alexander M Wolf, Takashi Yokota, Chikako Nito, Hiroshi Takahashi, Shigeo Ohta

    Biochimica et biophysica acta. General subjects   1867 ( 3 )   130302 - 130302   2022年12月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    BACKGROUND: Oxidative stress is involved in the progression of diabetes and its associated complications. However, it is unclear whether increased oxidative stress plays a primary role in the onset of diabetes or is a secondary indicator caused by tissue damage. Previous methods of analyzing oxidative stress have involved measuring the changes in oxidative stress biomarkers. Our aim is to identify a novel approach to clarify whether oxidative stress plays a primary role in the onset of diabetes. METHODS: We constructed transgenic type 2 diabetes mouse models expressing redox-sensitive green fluorescent proteins (roGFPs) that distinguished between mitochondria and whole cells. Pancreas, liver, skeletal muscle, and kidney redox states were measured in vivo. RESULTS: Hepatic mitochondrial oxidation increased when the mice were 4 weeks old and continued to increase in an age-dependent manner. The increase in hepatic mitochondrial oxidation occurred simultaneously with weight gain and increased blood insulin levels before the blood glucose levels increased. Administering the oxidative stress inducer acetaminophen increased the vulnerability of the liver mitochondria to oxidative stress. CONCLUSIONS: This study demonstrates that oxidative stress in liver mitochondria in mice begins at the onset of diabetes rather than after the disease has progressed. GENERAL SIGNIFICANCE: RoGFP-expressing transgenic type 2 diabetes mouse models are effective and convenient tools for measuring hepatic mitochondrial redox statuses in vivo. These models may be used to assess mitochondria-targeting antioxidants and establish the role of oxidative stress in type 2 diabetes.

    DOI: 10.1016/j.bbagen.2022.130302

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  • Molecular hydrogen suppresses free-radical-induced cell death by mitigating fatty acid peroxidation and mitochondrial dysfunction. 査読 国際誌

    Katsuya Iuchi, Kiyomi Nishimaki, Naomi Kamimura, Shigeo Ohta

    Canadian journal of physiology and pharmacology   97 ( 10 )   999 - 1005   2019年10月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    Molecular hydrogen (H2) was believed to be an inert and nonfunctional molecule in mammalian cells; however, we overturned the concept by reporting the therapeutic effects of H2 against oxidative stress. Subsequently, extensive studies revealed multiple functions of H2 by exhibiting the efficacies of H2 in various animal models and clinical studies. Here, we investigated the effect of H2 on free-radical-induced cytotoxicity using tert-butyl hydroperoxide in a human acute monocytic leukemia cell line, THP-1. Cell membrane permeability was determined using lactate dehydrogenase release assay and Hoechst 33342 and propidium iodide staining. Fatty acid peroxidation and mitochondrial viability were measured using 2 kinds of fluorescent dyes, Liperfluo and C11-BODIPY, and using the alamarBlue assay based on the reduction of resazurin to resorufin by mainly mitochondrial succinate dehydrogenase, respectively. Mitochondrial membrane potential was evaluated using tetramethylrhodamine methyl ester. As a result, H2 protected the cultured cells against the cytotoxic effects induced by tert-butyl hydroperoxide; H2 suppressed cellular fatty acid peroxidation and cell membrane permeability, mitigated the decline in mitochondrial oxidoreductase activity and mitochondrial membrane potential, and protected cells against cell death evaluated using propidium iodide staining. These results suggested that H2 suppresses free-radical-induced cell death through protection against fatty acid peroxidation and mitochondrial dysfunction.

    DOI: 10.1139/cjpp-2018-0741

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  • Rap1b Promotes Notch-Signal-Mediated Hematopoietic Stem Cell Development by Enhancing Integrin-Mediated Cell Adhesion. 査読 国際誌

    Seung-Sik Rho, Isao Kobayashi, Eri Oguri-Nakamura, Koji Ando, Masakazu Fujiwara, Naomi Kamimura, Hiromi Hirata, Atsuo Iida, Yoshiko Iwai, Naoki Mochizuki, Shigetomo Fukuhara

    Developmental cell   49 ( 5 )   681 - 696   2019年6月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    Hematopoietic stem cells (HSCs) emerge from hemogenic endothelium (HE) within the ventral portion of the dorsal aorta during vertebrate development. In zebrafish, Notch signaling induces HE specification from posterior lateral plate mesoderm (PLPM) cells as they migrate over the ventral surface of the somite. During migration, PLPM cells make close contact with Notch-ligand-expressing somitic cells to acquire HE identity. Herein, we show in zebrafish that the small GTPase Rap1b regulates HSC development by potentiating Notch-mediated HE specification. PLPM cells migrate toward the midline along the somite boundary where fibronectin accumulates. Rap1b stimulates integrin β1 to enhance PLPM cell adhesion to fibronectin localized at the somite boundary. Rap1b-induced integrin-β1-mediated adhesion to fibronectin leads to the spreading of PLPM cells to facilitate their physical contact with the Notch-ligand-expressing somitic cells, thereby promoting Notch-mediated HE specification. Thus, we have revealed an unexpected role of Rap1-induced integrin-mediated cell adhesion in HSC development.

    DOI: 10.1016/j.devcel.2019.03.023

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  • Development of Cancer Immunotherapy Targeting the PD-1 Pathway. 査読

    Kamimura N, Wolf AM, Iwai Y

    Journal of Nippon Medical School = Nippon Ika Daigaku zasshi   86 ( 1 )   10 - 14   2019年

  • Taurine supplementation for prevention of stroke-like episodes in MELAS: A multicentre, open-label, 52-week phase III trial 査読

    Yutaka Ohsawa, Hiroki Hagiwara, Shin-Ichiro Nishimatsu, Akihiro Hirakawa, Naomi Kamimura, Hideaki Ohtsubo, Yuta Fukai, Tatsufumi Murakami, Yasutoshi Koga, Yu-Ichi Goto, Shigeo Ohta, Yoshihide Sunada

    Journal of Neurology, Neurosurgery and Psychiatry   90 ( 5 )   529 - 536   2018年4月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:BMJ Publishing Group  

    Objective: The aim of this study was to evaluate the efficacy and safety of high-dose taurine supplementation for prevention of stroke-like episodes of MELAS (mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes), a rare genetic disorder caused by point mutations in the mitochondrial DNA that lead to a taurine modification defect at the first anticodon nucleotide of mitochondrial tRNALeu(UUR), resulting in failure to decode codons accurately. Methods: After the nationwide survey of MELAS, we conducted a multicentre, open-label, phase III trial in which 10 patients with recurrent stroke-like episodes received high-dose taurine (9 g or 12 g per day) for 52 weeks. The primary endpoint was the complete prevention of stroke-like episodes during the evaluation period. The taurine modification rate of mitochondrial tRNALeu(UUR) was measured before and after the trial. Results: The proportion of patients who reached the primary endpoint (100% responder rate) was 60% (95% CI 26.2% to 87.8%). The 50% responder rate, that is, the number of patients achieving a 50% or greater reduction in frequency of stroke-like episodes, was 80% (95% CI 44.4% to 97.5%). Taurine reduced the annual relapse rate of stroke-like episodes from 2.22 to 0.72 (P=0.001). Five patients showed a significant increase in the taurine modification of mitochondrial tRNALeu(UUR) from peripheral blood leukocytes (P&lt
    0.05). No severe adverse events were associated with taurine. Conclusions: The current study demonstrates that oral taurine supplementation can effectively reduce the recurrence of stroke-like episodes and increase taurine modification in mitochondrial tRNALeu(UUR) in MELAS. Trial registration number: UMIN000011908.

    DOI: 10.1136/jnnp-2018-317964

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  • Effects of Molecular Hydrogen Assessed by an Animal Model and a Randomized Clinical Study on Mild Cognitive Impairment. 査読 国際誌

    Nishimaki K, Asada T, Ohsawa I, Nakajima E, Ikejima C, Yokota T, Kamimura N, Ohta S

    Current Alzheimer research   15 ( 5 )   482 - 492   2018年3月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    DOI: 10.2174/1567205014666171106145017

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  • Protective Effect of Hydrogen Gas Inhalation on Muscular Damage Using a Mouse Hindlimb Ischemia-Reperfusion Injury Model. 査読 国際誌

    Mai Watanabe, Naomi Kamimura, Katsuya Iuchi, Kiyomi Nishimaki, Takashi Yokota, Rei Ogawa, Shigeo Ohta

    Plastic and reconstructive surgery   140 ( 6 )   1195 - 1206   2017年12月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    BACKGROUND: Ischemia-reperfusion injury is one of the leading causes of tissue damage and dysfunction, in particular, free tissue transfer, traumatically amputated extremity, and prolonged tourniquet application during extremity surgery. In this study, the authors investigated the therapeutic effects of hydrogen gas on skeletal muscle ischemia-reperfusion injury. METHODS: The authors compared the concentration of hydrogen in a muscle on intraperitoneal administration of hydrogen-rich saline and on inhalation of hydrogen gas. Animals were subjected to ischemia-reperfusion. Mice were treated with inhalation of hydrogen gas, and the hind gastrocnemius muscle was collected. Muscle morphology and inflammatory change were evaluated after ischemia-reperfusion. Moreover, a footprint test was performed to assess the functional effect of hydrogen. RESULTS: Hydrogen concentration of tissue was significantly higher, and the elevated level was maintained longer by hydrogen gas inhalation than by intraperitoneal administration of hydrogen-rich saline. Infarct zone and area with loss of tissue structure and marked cellular infiltration were significantly decreased in groups treated by hydrogen gas inhalation during ischemia-reperfusion; however, these effects were not observed by posttreatment of hydrogen. One week after ischemia-reperfusion, mice that had been pretreated with hydrogen gas recovered faster and achieved smoother walking in appearance compared with mice in the other groups as assessed by the footprint test. CONCLUSIONS: Inhalation of hydrogen gas attenuates muscle damage, inhibits inflammatory response, and enhances functional recovery. These findings suggest that the optimal route for hydrogen delivery is continuous inhalation of hydrogen gas, which could be a novel clinical mode of treatment in ischemia-reperfusion injury.

    DOI: 10.1097/PRS.0000000000003878

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  • Cisplatin selects short forms of the mitochondrial DNA OriB variant (16184-16193 poly-cytosine tract), which confer resistance to cisplatin 査読

    Taku Amo, Naomi Kamimura, Hiromasa Asano, Sadamitsu Asoh, Shigeo Ohta

    SCIENTIFIC REPORTS   7   46240   2017年4月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:NATURE PUBLISHING GROUP  

    A number of alternations in mitochondrial DNA (mtDNA) have been reported in different types of cancers, and the role of mtDNA in cancer has been attracting increasing interest. In order to investigate the relationship between mtDNA alternations and chemosensitivity, we constructed cybrid (trans-mitochondrial hybrid) cell lines carrying a HeLa nucleus and the mtDNA of healthy individuals because of the presence of somatic alternations in the mtDNA of many cancer cells. After a treatment with 1.0 mu g/mL cisplatin for 10 days, we isolated 100 cisplatin-resistant clones, 70 of which carried the shorter mtDNA OriB variant (16184-16193 poly-cytosine tract), which was located in the control region of mtDNA. Whole mtDNA sequencing of 10 clones revealed no additional alternations. Re-construction of the HeLa nucleus and mtDNA from cisplatin-resistant cells showed that cisplatin resistance was only acquired by mtDNA alternations in the control region, and not by possible alternation(s) in the nuclear genome.

    DOI: 10.1038/srep46240

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  • The histone 3 lysine 9 methyltransferase inhibitor chaetocin improves prognosis in a rat model of high salt diet-induced heart failure 査読

    Tomohiko Ono, Naomi Kamimura, Tomohiro Matsuhashi, Toshihiro Nagai, Takahiko Nishiyama, Jin Endo, Takako Hishiki, Tsuyoshi Nakanishi, Noriaki Shimizu, Hirotoshi Tanaka, Shigeo Ohta, Makoto Suematsu, Masaki Ieda, Motoaki Sano, Keiichi Fukuda, Ruri Kaneda

    SCIENTIFIC REPORTS   7   39752   2017年1月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:NATURE PUBLISHING GROUP  

    Histone acetylation has been linked to cardiac hypertrophy and heart failure. However, the pathological implications of changes in histone methylation and the effects of interventions with histone methyltransferase inhibitors for heart failure have not been fully clarified. Here, we focused on H3K9me3 status in the heart and investigated the effects of the histone H3K9 methyltransferase inhibitor chaetocin on prognoses in Dahl salt-sensitive rats, an animal model of chronic heart failure. Chaetocin prolonged survival and restored mitochondrial dysfunction. ChIP-seq analysis demonstrated that chronic stress to the heart induced H3K9me3 elevation in thousands of repetitive elements, including intronic regions of mitochondria-related genes, such as the gene encoding peroxisome proliferator-activated receptor-gamma coactivator 1 alpha. Furthermore, chaetocin reversed this effect on these repetitive loci. These data suggested that excessive heterochromatinization of repetitive elements of mitochondrial genes in the failing heart may lead to the silencing of genes and impair heart function. Thus, chaetocin may be a potential therapeutic agent for chronic heart failure.

    DOI: 10.1038/srep39752

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  • 水素水による脳機能維持効果と健康増進への展望

    上村 尚美, 太田 成男

    体力科学   66 ( 1 )   63 - 63   2017年

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    記述言語:日本語   出版者・発行元:一般社団法人日本体力医学会  

    DOI: 10.7600/jspfsm.66.63_2

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  • Fucoidan alleviates high-fat diet-induced dyslipidemia and atherosclerosis in ApoE(Shl) mice deficient in apolipoprotein E expression 査読

    Takashi Yokota, Koichi Nomura, Mikio Nagashima, Naomi Kamimura

    JOURNAL OF NUTRITIONAL BIOCHEMISTRY   32   46 - 54   2016年6月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ELSEVIER SCIENCE INC  

    Fucoidan, a sulfated polysaccharide extracted from brown seaweeds, possesses many biological activities including anti-inflammatory and antioxidantactivities. We aimed to investigate the protective effects of fucoidan on dyslipidemia and atherosclerosis in apolipoprotein E-deficient mice (ApoE(shl) mice) and to elucidate its molecular targets in the liver by using a transcriptomic approach. For 12 weeks, ApoE(shl) mice were fed a high-fat diet (HFD) supplemented with either 1% or 5% fucoidan. Fucoidan supplementation significantly reduced tissue weight (liver and white adipose tissue), blood lipid, total cholesterol (TC), triglyceride (TG), non-high-density lipoprotein cholesterol (non-HDL-C) and glucose levels in HFD-fed ApoE(shl) mice but increased plasma lipoprotein lipase (LPL) activity and HDL-C levels. Fucoidan also reduced hepatic steatosis levels (liver size, TC and TG levels, and lipid peroxidation) and increased white adipose tissue LPL activity. DNA microarray analysis and quantitative reverse transcription-polymerase chain reaction demonstrated differential expression of genes encoding proteins involved in lipid metabolism, energy homeostasis and insulin sensitivity, by activating Ppara and inactivating Srebf1. Fucoidan supplementation markedly reduced the thickness of the lipid-rich plaque, lipid peroxidation and foaming macrophage accumulation in the aorta in HFD-fed ApoE(shl) mice. Thus, fucoidan supplementation appears to have anti-dyslipidemic and anti-atherosclerotic effects by inducing LPL activity and inhibiting the effects of inflammation and oxidative stress in HFD-fed ApoE(shl) mice. (C) 2016 Elsevier Inc. All rights reserved.

    DOI: 10.1016/j.jnutbio.2016.01.011

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  • Molecular hydrogen regulates gene expression by modifying the free radical chain reaction-dependent generation of oxidized phospholipid mediators. 査読 国際誌

    Katsuya Iuchi, Akemi Imoto, Naomi Kamimura, Kiyomi Nishimaki, Harumi Ichimiya, Takashi Yokota, Shigeo Ohta

    Scientific reports   6   18971 - 18971   2016年1月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    We previously showed that H2 acts as a novel antioxidant to protect cells against oxidative stress. Subsequently, numerous studies have indicated the potential applications of H2 in therapeutic and preventive medicine. Moreover, H2 regulates various signal transduction pathways and the expression of many genes. However, the primary targets of H2 in the signal transduction pathways are unknown. Here, we attempted to determine how H2 regulates gene expression. In a pure chemical system, H2 gas (approximately 1%, v/v) suppressed the autoxidation of linoleic acid that proceeds by a free radical chain reaction, and pure 1-palmitoyl-2-arachidonyl-sn-glycero-3-phosphocholine (PAPC), one of the major phospholipids, was autoxidized in the presence or absence of H2. H2 modified the chemical production of the autoxidized phospholipid species in the cell-free system. Exposure of cultured cells to the H2-dependently autoxidized phospholipid species reduced Ca(2+) signal transduction and mediated the expression of various genes as revealed by comprehensive microarray analysis. In the cultured cells, H2 suppressed free radical chain reaction-dependent peroxidation and recovered the increased cellular Ca(2+), resulting in the regulation of Ca(2+)-dependent gene expression. Thus, H2 might regulate gene expression via the Ca(2+) signal transduction pathway by modifying the free radical-dependent generation of oxidized phospholipid mediators.

    DOI: 10.1038/srep18971

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  • Molecular hydrogen stimulates the gene expression of transcriptional coactivator PGC-1α to enhance fatty acid metabolism. 査読 国際誌

    Kamimura N, Ichimiya H, Iuchi K, Ohta S

    NPJ aging and mechanisms of disease   2   16008 - 16008   2016年

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    DOI: 10.1038/npjamd.2016.8

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  • Protective effect of molecular hydrogen against oxidative stress caused by peroxynitrite derived from nitric oxide in rat retina 査読

    Takashi Yokota, Naomi Kamimura, Tsutomu Igarashi, Hiroshi Takahashi, Shigeo Ohta, Hideaki Oharazawa

    CLINICAL AND EXPERIMENTAL OPHTHALMOLOGY   43 ( 6 )   568 - 577   2015年8月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:WILEY-BLACKWELL  

    BackgroundOxidative and nitrative processes have an important role in the pathogenesis of glaucomatous neurodegeneration. Oxidative stress occurs when cellular production of reactive oxygen species outweighs the protective capacity of antioxidant defences. Reactive oxygen species are generated as by-products of cellular metabolism, primarily in the mitochondria. Herein, we present a novel investigation of the effects of molecular hydrogen (H-2) on retinal cells exposed to oxidative stress.
    MethodsWe cultured adult rat retinal tissues in an organotypic culture system with a nitric oxide donor, S-nitroso-N-acetylpenicillamine, in the presence or absence of H-2. Loss of mitochondrial membrane potential and apoptosis of retinal cells were analysed using a MitoTMRE detection kit and TdT-mediated dUTP nick end labeling (TUNEL) assay, respectively. Tyrosine nitration levels and oxidative stress damage in the retina were evaluated using immunohistochemical staining. Retinal damage was quantified by measuring the numbers of cells in the ganglion cell and inner nuclear layers and the thickness of the retina.
    ResultsH(2) suppressed loss of mitochondrial membrane potential and apoptosis in retinal cells. Moreover, H-2 decreased the tyrosine nitration level and suppressed oxidative stress damage in retinal cells. S-nitroso-N-acetylpenicillamine treatment decreased the cell numbers in the ganglion cell layer and inner nuclear layer, but the presence of H-2 inhibited this reduction. These findings suggest that H-2 has a neuroprotective effect against retinal cell oxidative damage, presumably by scavenging peroxynitrite.
    ConclusionsH(2) reduces cellular peroxynitrite, a highly toxic reactive nitrogen species. Thus, H-2 may be an effective and novel clinical tool for treating glaucoma and other oxidative stress-related diseases.

    DOI: 10.1111/ceo.12525

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  • Intravenous transplantation of bone marrow-derived mononuclear cells prevents memory impairment in transgenic mouse models of Alzheimer's disease. 査読 国際誌

    Takuya Kanamaru, Naomi Kamimura, Takashi Yokota, Kiyomi Nishimaki, Katsuya Iuchi, Hyunjin Lee, Shinya Takami, Hiroki Akashiba, Yoshitsugu Shitaka, Masayuki Ueda, Ken-Ichiro Katsura, Kazumi Kimura, Shigeo Ohta

    Brain research   1605   49 - 58   2015年4月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    Stem cell transplantation therapy is currently in clinical trials for the treatment of ischemic stroke, and several beneficial aspects have been reported. Similarly, in Alzheimer's disease (AD), stem cell therapy is expected to provide an efficient therapeutic approach. Indeed, the intracerebral transplantation of stem cells reduced amyloid-β (Aβ) deposition and rescued memory deficits in AD model mice. Here, we show that intravenous transplantation of bone marrow-derived mononuclear cells (BMMCs) improves cognitive function in two different AD mouse models, DAL and APP mice, and prevents neurodegeneration. GFP-positive BMMCs were isolated from tibiae and femurs of 4-week-old mice and then transplanted intravenously into DAL and APP mice. Transplantation of BMMCs suppressed neuronal loss and restored memory impairment of DAL mice to almost the same level as in wild-type mice. Transplantation of BMMCs to APP mice reduced Aβ deposition in the brain. APP mice treated with BMMCs performed significantly better on behavioral tests than vehicle-injected mice. Moreover, the effects were observed even with transplantation after the onset of cognitive impairment in DAL mice. Together, our results indicate that intravenous transplantation of BMMCs has preventive effects against the cognitive decline in AD model mice and suggest a potential therapeutic effect of BMMC transplantation therapy.

    DOI: 10.1016/j.brainres.2015.02.011

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  • Oxidative stress accelerates amyloid deposition and memory impairment in a double-transgenic mouse model of Alzheimer's disease. 査読 国際誌

    Takuya Kanamaru, Naomi Kamimura, Takashi Yokota, Katsuya Iuchi, Kiyomi Nishimaki, Shinya Takami, Hiroki Akashiba, Yoshitsugu Shitaka, Ken-Ichiro Katsura, Kazumi Kimura, Shigeo Ohta

    Neuroscience letters   587   126 - 31   2015年2月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    Oxidative stress is known to play a prominent role in the onset and early stage progression of Alzheimer's disease (AD). For example, protein oxidation and lipid peroxidation levels are increased in patients with mild cognitive impairment. Here, we created a double-transgenic mouse model of AD to explore the pathological and behavioral effects of oxidative stress. Double transgenic (APP/DAL) mice were constructed by crossing Tg2576 (APP) mice, which express a mutant form of human amyloid precursor protein (APP), with DAL mice expressing a dominant-negative mutant of mitochondrial aldehyde dehydrogenase 2 (ALDH2), in which oxidative stress is enhanced. Y-maze and object recognition tests were performed at 3 and 6 months of age to evaluate learning and memory. The accumulation of amyloid plaques, deposition of phosphorylated-tau protein, and number of astrocytes in the brain were assessed histopathologically at 3, 6, 9, and 12-15 months of age. The life span of APP/DAL mice was significantly shorter than that of APP or DAL mice. In addition, they showed accelerated amyloid deposition, tau phosphorylation, and gliosis. Furthermore, these mice showed impaired performance on Y-maze and object recognition tests at 3 months of age. These data suggest that oxidative stress accelerates cognitive dysfunction and pathological insults in the brain. APP/DAL mice could be a useful model for exploring new approaches to AD treatment.

    DOI: 10.1016/j.neulet.2014.12.033

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  • Hydrogen Inhalation During Normoxic Resuscitation Improves Neurological Outcome in a Rat Model of Cardiac Arrest Independently of Targeted Temperature Management 査読

    Kei Hayashida, Motoaki Sano, Naomi Kamimura, Takashi Yokota, Masaru Suzuki, Shigeo Ohta, Keiichi Fukuda, Shingo Hori

    CIRCULATION   130 ( 24 )   2173 - 2180   2014年12月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:LIPPINCOTT WILLIAMS & WILKINS  

    Background-We have previously shown that hydrogen (H-2) inhalation, begun at the start of hyperoxic cardiopulmonary resuscitation, significantly improves brain and cardiac function in a rat model of cardiac arrest. Here, we examine the effectiveness of this therapeutic approach when H-2 inhalation is begun on the return of spontaneous circulation (ROSC) under normoxic conditions, either alone or in combination with targeted temperature management (TTM).
    Methods and Results-Rats were subjected to 6 minutes of ventricular fibrillation cardiac arrest followed by cardiopulmonary resuscitation. Five minutes after achieving ROSC, post-cardiac arrest rats were randomized into 4 groups: mechanically ventilated with 26% O-2 and normothermia (control); mechanically ventilated with 26% O-2, 1.3% H-2, and normothermia (H-2); mechanically ventilated with 26% O-2 and TTM (TTM); and mechanically ventilated with 26% O-2, 1.3% H-2, and TTM (TTM+H-2). Animal survival rate at 7 days after ROSC was 38.4% in the control group, 71.4% in the H-2 and TTM groups, and 85.7% in the TTM+H-2 group. Combined therapy of TTM and H-2 inhalation was superior to TTM alone in terms of neurological deficit scores at 24, 48, and 72 hours after ROSC, and motor activity at 7 days after ROSC. Neuronal degeneration and microglial activation in a vulnerable brain region was suppressed by both TTM alone and H-2 inhalation alone, with the combined therapy of TTM and H-2 inhalation being most effective.
    Conclusions-H-2 inhalation was beneficial when begun after ROSC, even when delivered in the absence of hyperoxia. Combined TTM and H-2 inhalation was more effective than TTM alone.

    DOI: 10.1161/CIRCULATIONAHA.114.011848

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  • Real-Time Monitoring of Oxidative Stress in Live Mouse Skin 査読

    Alexander M. Wolf, Kiyomi Nishimaki, Naomi Kamimura, Shigeo Ohta

    JOURNAL OF INVESTIGATIVE DERMATOLOGY   134 ( 6 )   1701 - 1709   2014年6月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:NATURE PUBLISHING GROUP  

    Oxidative stress is involved in many age-associated diseases, as well as in the aging process itself. The development of interventions to reduce oxidative stress is hampered by the absence of sensitive detection methods that can be used in live animals. We generated transgenic mice expressing ratiometric redox-sensitive green fluorescent protein (roGFP) in the cytosol or mitochondria of several tissues, including skin epidermal keratinocytes. Crossbreeding into hairless albino mice allowed noninvasive optical measurement of skin oxidative state. Topical application of hydrogen peroxide emulsion shifted the keratinocyte redox state toward oxidation within minutes and could be observed in real time by fluorescence ratio imaging. Exposing skin to 365 nm UVA radiation oxidized roGFP localized in keratinocyte mitochondria, but not when roGFP was localized in the cytosol. This suggests that significant amounts of the endogenous photosensitizers that mediate UVA induced oxidative stress are located in the mitochondria. UVR is the major environmental cause of skin aging and UVA mediated oxidative stress has been associated with the development of wrinkles in humans. Direct measurements of redox state in defined cell compartments of live animals should be a powerful and convenient tool for evaluating treatments that aim to modulate oxidative stress.

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  • Inhibition of Endothelial p53 Improves Metabolic Abnormalities Related to Dietary Obesity 査読

    Masataka Yokoyama, Sho Okada, Atsushi Nakagomi, Junji Moriya, Ippei Shimizu, Aika Nojima, Yohko Yoshida, Harumi Ichimiya, Naomi Kamimura, Yoshio Kobayashi, Shigeo Ohta, Marcus Fruttiger, Guillermina Lozano, Tohru Minamino

    CELL REPORTS   7 ( 5 )   1691 - 1703   2014年6月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:CELL PRESS  

    Accumulating evidence has suggested a role for p53 activation in various age-associated conditions. Here, we identified a crucial role of endothelial p53 activation in the regulation of glucose homeostasis. Endothelial expression of p53 was markedly upregulated when mice were fed a high-calorie diet. Disruption of endothelial p53 activation improved dietary inactivation of endothelial nitric oxide synthase that upregulated the expression of peroxisome proliferator-activated receptor-gamma coactivator-1 alpha in skeletal muscle, thereby increasing mitochondrial biogenesis and oxygen consumption. Mice with endothelial cell-specific p53 deficiency fed a high-calorie diet showed improvement of insulin sensitivity and less fat accumulation, compared with control littermates. Conversely, upregulation of endothelial p53 caused metabolic abnormalities. These results indicate that inhibition of endothelial p53 could be a novel therapeutic target to block the vicious cycle of cardiovascular and metabolic abnormalities associated with obesity.

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  • Haploinsufficiency of Akt1 Prolongs the Lifespan of Mice 査読

    Aika Nojima, Masakatsu Yamashita, Yohko Yoshida, Ippei Shimizu, Harumi Ichimiya, Naomi Kamimura, Yoshio Kobayashi, Shigeo Ohta, Naoaki Ishii, Tohru Minamino

    PLoS ONE   8 ( 7 )   e69178   2013年7月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    There is increasing evidence that nutrient-sensing machinery is critically involved in the regulation of aging. The insulin/insulin-like growth factor-1 signaling pathway is the best-characterized pathway with an influence on longevity in a variety of organisms, ranging from yeast to rodents. Reduced expression of the receptor for this pathway has been reported to prolong the lifespan
    however, the underlying mechanisms are largely unknown. Here we show that haploinsufficiency of Akt1 leads to an increase of the lifespan in mice. Akt1+/- mice had a lower body weight than their littermates with less fat mass and normal glucose metabolism. Ribosomal biogenesis and the mitochondrial DNA content were significantly reduced in these mice, along with a decrease of oxidative stress. Consistent with the results obtained in mice, inhibition of Akt-1 promoted longevity in nematodes (Caenorhabditis elegans), whereas activation of Akt-1 shortened the lifespan. Inhibition of Akt-1 led to a decrease of ribosomal gene expression and the mitochondrial DNA content in both human cells and nematodes. Moreover, deletion of ribosomal gene expression resulted in a decrease of the mitochondrial DNA content and normalized the lifespan shortened by Akt-1 activation in nematodes. These results suggest that an increase of mitochondrial amount and energy expenditure associated with enhanced protein synthesis accelerates both aging and the onset of age-associated diseases. © 2013 Nojima et al.

    DOI: 10.1371/journal.pone.0069178

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  • ミトコンドリア機能と老化・疾患制御

    太田 成男, 上村 尚美, ウォルフ・アクレサンダー, 井内 勝哉, 佐野 元昭, 新村 健

    日本抗加齢医学会総会プログラム・抄録集   13回   163 - 163   2013年6月

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    記述言語:日本語   出版者・発行元:(一社)日本抗加齢医学会  

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  • Involvement of PGC-1α in the formation and maintenance of neuronal dendritic spines. 査読

    Cheng A, Wan R, Yang JL, Kamimura N, Son TG, Ouyang X, Luo Y, Okun E, Mattson MP

    Nature communications   3   1250   2012年12月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    DOI: 10.1038/ncomms2238

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  • H-2 Gas Improves Functional Outcome After Cardiac Arrest to an Extent Comparable to Therapeutic Hypothermia in a Rat Model 査読

    Kei Hayashida, Motoaki Sano, Naomi Kamimura, Takashi Yokota, Masaru Suzuki, Yuichiro Maekawa, Akio Kawamura, Takayuki Abe, Shigeo Ohta, Keiichi Fukuda, Shingo Hori

    JOURNAL OF THE AMERICAN HEART ASSOCIATION   1 ( 5 )   e003459   2012年10月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:WILEY-BLACKWELL  

    Background-All clinical and biological manifestations related to postcardiac arrest (CA) syndrome are attributed to ischemia-reperfusion injury in various organs including brain and heart. Molecular hydrogen (H-2) has potential as a novel antioxidant. This study tested the hypothesis that inhalation of H-2 gas starting at the beginning of cardiopulmonary resuscitation (CPR) could improve the outcome of CA.
    Methods and Results-Ventricular fibrillation was induced by transcutaneous electrical epicardial stimulation in rats. After 5 minutes of the subsequent CA, rats were randomly assigned to 1 of 4 experimental groups at the beginning of CPR: mechanical ventilation (MV) with 2% N-2 and 98% O-2 under normothermia (37 degrees C), the control group; MV with 2% H-2 and 98% O-2 under normothermia; MV with 2% N-2 and 98% O-2 under therapeutic hypothermia (TH), 33 degrees C; and MV with 2% H-2 and 98% O-2 under TH. Mixed gas inhalation and TH continued until 2 hours after the return of spontaneous circulation (ROSC). H-2 gas inhalation yielded better improvement in survival and neurological deficit score (NDS) after ROSC to an extent comparable to TH. H-2 gas inhalation, but not TH, prevented a rise in left ventricular end-diastolic pressure and increase in serum IL-6 level after ROSC. The salutary impact of H-2 gas was at least partially attributed to the radical-scavenging effects of H-2 gas, because both 8-OHdG- and 4-HNE-positive cardiomyocytes were markedly suppressed by H-2 gas inhalation after ROSC.
    Conclusions-Inhalation of H-2 gas is a favorable strategy to mitigate mortality and functional outcome of post-CA syndrome in a rat model, either alone or in combination with TH.

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  • Taurine Ameliorates Impaired the Mitochondrial Function and Prevents Stroke-like Episodes in Patients with MELAS 査読

    Mitsue Rikimaru, Yutaka Ohsawa, Alexander M. Wolf, Kiyomi Nishimaki, Harumi Ichimiya, Naomi Kamimura, Shin-ichiro Nishimatsu, Shigeo Ohta, Yoshihide Sunada

    INTERNAL MEDICINE   51 ( 24 )   3351 - 3357   2012年

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:JAPAN SOC INTERNAL MEDICINE  

    Objective Post-transcriptional taurine modification at the first anticodon ("wobble") nucleotide is deficient in A3243G-mutant mitochondrial (mt) tRNA(Leu(UUR)) of patients with myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS). Wobble nucleotide modifications in tRNAs have recently been identified to be important in the accurate and efficient deciphering of codons. We herein examined whether taurine can alleviate mitochondrial dysfunction in patient-derived pathogenic cells and prevent clinical symptoms in MELAS patients.
    Methods and Results The addition of taurine to the culture media ameliorated the reduced oxygen consumption, decreased the mitochondrial membrane potential, and increased the oxidative stress in MELAS patient-derived cells. Moreover, high dose oral administration of taurine (0.25 g/kg/day) completely prevented stroke-like episodes in two MELAS patients for more than nine years.
    Conclusion Taurine supplementation may be a novel potential treatment option for preventing the stroke-like episodes associated with MELAS.

    DOI: 10.2169/internalmedicine.51.7529

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  • Overexpression of KLF15 Transcription Factor in Adipocytes of Mice Results in Down-regulation of SCD1 Protein Expression in Adipocytes and Consequent Enhancement of Glucose-induced Insulin Secretion 査読

    Tomoki Nagare, Hiroshi Sakaue, Michihiro Matsumoto, Yongheng Cao, Kenjiro Inagaki, Mashito Sakai, Yasuhiro Takashima, Kyoko Nakamura, Toshiyuki Mori, Yuko Okada, Yasushi Matsuki, Eijiro Watanabe, Kazutaka Ikeda, Ryo Taguchi, Naomi Kamimura, Shigeo Ohta, Ryuji Hiramatsu, Masato Kasuga

    JOURNAL OF BIOLOGICAL CHEMISTRY   286 ( 43 )   37458 - 37469   2011年10月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC  

    Kruppel-like factor 15 (KLF15), a member of the Kruppel-like factor family of transcription factors, has been found to play diverse roles in adipocytes in vitro. However, little is known of the function of KLF15 in adipocytes in vivo. We have now found that the expression of KLF15 in adipose tissue is down-regulated in obese mice, and we therefore generated adipose tissue-specific KLF15 transgenic (aP2-KLF15Tg) mice to investigate the possible contribution of KLF15 to various pathological conditions associated with obesity in vivo. The aP2-KLF15 Tg mice manifest insulin resistance and are resistant to the development of obesity induced by maintenance on a high fat diet. However, they also exhibit improved glucose tolerance as a result of enhanced insulin secretion. Furthermore, this enhancement of insulin secretion was shown to result from down-regulation of the expression of stearoyl-CoA desaturase 1 (SCD1) in white adipose tissue and a consequent reduced level of oxidative stress. This is supported by the findings that restoration of SCD1 expression in white adipose tissue of aP2-KLF15 Tg mice exhibited increased oxidative stress in white adipose tissue and reduced insulin secretion with hyperglycemia. Our data thus provide an example of cross-talk between white adipose tissue and pancreatic beta cells mediated through modulation of oxidative stress.

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  • Hydrogen therapy attenuates irradiation-induced lung damage by reducing oxidative stress 査読

    Yasuhiro Terasaki, Ikuroh Ohsawa, Mika Terasaki, Mikiko Takahashi, Shinobu Kunugi, Kang Dedong, Hirokazu Urushiyama, Shunsuke Amenomori, Mayuko Kaneko-Togashi, Naomi Kuwahara, Arimi Ishikawa, Naomi Kamimura, Shigeo Ohta, Yuh Fukuda

    AMERICAN JOURNAL OF PHYSIOLOGY-LUNG CELLULAR AND MOLECULAR PHYSIOLOGY   301 ( 4 )   L415 - L426   2011年10月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:AMER PHYSIOLOGICAL SOC  

    Terasaki Y, Ohsawa I, Terasaki M, Takahashi M, Kunugi S, Dedong K, Urushiyama H, Amenomori S, Kaneko-Togashi M, Kuwahara N, Ishikawa A, Kamimura N, Ohta S, Fukuda Y. Hydrogen therapy attenuates irradiation-induced lung damage by reducing oxidative stress. Am J Physiol Lung Cell Mol Physiol 301: L415-L426, 2011. First published July 15, 2011; doi: 10.1152/ajplung.00008.2011.-Molecular hydrogen (H-2) is an efficient antioxidant that diffuses rapidly across cell membranes, reduces reactive oxygen species (ROS), such as hydroxyl radicals and peroxynitrite, and suppresses oxidative stress-induced injury in several organs. ROS have been implicated in radiation-induced damage to lungs. Because prompt elimination of irradiation-induced ROS should protect lung tissue from damaging effects of irradiation, we investigated the possibility that H-2 could serve as a radioprotector in the lung. Cells of the human lung epithelial cell line A549 received 10 Gy irradiation with or without H-2 treatment via H-2-rich PBS or medium. We studied the possible radioprotective effects of H-2 by analyzing ROS and cell damage. Also, C57BL/6J female mice received 15 Gy irradiation to the thorax. Treatment groups inhaled 3% H-2 gas and drank H-2-enriched water. We evaluated acute and late-irradiation lung damage after H-2 treatment. H-2 reduced the amount of irradiation-induced ROS in A549 cells, as shown by electron spin resonance and fluorescent indicator signals. H-2 also reduced cell damage, measured as levels of oxidative stress and apoptotic markers, and improved cell viability. Within 1 wk after whole thorax irradiation, immunohistochemistry and immunoblotting showed that H-2 treatment reduced oxidative stress and apoptosis, measures of acute damage, in the lungs of mice. At 5 mo after irradiation, chest computed tomography, Ashcroft scores, and type III collagen deposition demonstrated that H-2 treatment reduced lung fibrosis (late damage). This study thus demonstrated that H-2 treatment is valuable for protection against irradiation lung damage with no known toxicity.

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  • Caloric Restriction Primes Mitochondria for Ischemic Stress by Deacetylating Specific Mitochondrial Proteins of the Electron Transport Chain 査読

    Ken Shinmura, Kayoko Tamaki, Motoaki Sano, Naomi Nakashima-Kamimura, Alexander M. Wolf, Taku Amo, Shigeo Ohta, Yoshinori Katsumata, Keiichi Fukuda, Kyoko Ishiwata, Makoto Suematsu, Takeshi Adachi

    CIRCULATION RESEARCH   109 ( 4 )   396 - 406   2011年8月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:LIPPINCOTT WILLIAMS & WILKINS  

    Rationale: Caloric restriction (CR) confers cardioprotection against ischemia/reperfusion injury. However, the exact mechanism(s) underlying CR-induced cardioprotection remain(s) unknown. Recent evidence indicates that Sirtuins, NAD(+)-dependent deacetylases, regulate various favorable aspects of the CR response. Thus, we hypothesized that deacetylation of specific mitochondrial proteins during CR preserves mitochondrial function and attenuates production of reactive oxygen species during ischemia/reperfusion.
    Objective: The objectives of the present study were (1) to investigate the effect of CR on mitochondrial function and mitochondrial proteome and (2) to investigate what molecular mechanisms mediate CR-induced cardioprotection.
    Methods and Results: Male 26-week-old Fischer344 rats were randomly divided into ad libitum-fed and CR (40% reduction) groups for 6 months. No change was observed in basal mitochondrial function, but CR preserved postischemic mitochondrial respiration and attenuated postischemic mitochondrial H2O2 production. CR decreased the level of acetylated mitochondrial proteins that were associated with enhanced Sirtuin activity in the mitochondrial fraction. We confirmed a significant decrease in the acetylated forms of NDUFS1 and cytochrome bc1 complex Rieske subunit in the CR heart. Low-dose Resveratrol treatment mimicked the effect of CR on deacetylating them and attenuated reactive oxygen species production during anoxia/reoxygenation in cultured cardiomyocytes without changing the expression levels of manganese superoxide dismutase. Treatment with nicotinamide completely abrogated the effect of low-dose Resveratrol.
    Conclusions: These results strongly suggest that CR primes mitochondria for stress resistance by deacetylating specific mitochondrial proteins of the electron transport chain. Targeted deacetylation of NDUFS1 and/or Rieske subunit might have potential as a novel therapeutic approach for cardioprotection against ischemia/reperfusion. (Circ Res. 2011;109:396-406.)

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  • Molecular Hydrogen Improves Obesity and Diabetes by Inducing Hepatic FGF21 and Stimulating Energy Metabolism in db/db Mice 査読

    Naomi Kamimura, Kiyomi Nishimaki, Ikuroh Ohsawa, Shigeo Ohta

    OBESITY   19 ( 7 )   1396 - 1403   2011年7月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:WILEY-BLACKWELL  

    Recent extensive studies have revealed that molecular hydrogen (H-2) has great potential for improving oxidative stress-related diseases by inhaling H-2 gas, injecting saline with dissolved H-2, or drinking water with dissolved H-2 (H-2-water); however, little is known about the dynamic movement of H-2 in a body. First, we show that hepatic glycogen accumulates H-2 after oral administration of H-2-water, explaining why consumption of even a small amount of H-2 over a short span time efficiently improves various disease models. This finding was supported by an in vitro experiment in which glycogen solution maintained H-2. Next, we examined the benefit of ad libitum drinking H-2-water to type 2 diabetes using db/db obesity model mice lacking the functional leptin receptor. Drinking H-2-water reduced hepatic oxidative stress, and significantly alleviated fatty liver in db/db mice as well as high fat-diet-induced fatty liver in wild-type mice. Long-term drinking H-2-water significantly controlled fat and body weights, despite no increase in consumption of diet and water. Moreover, drinking H-2-water decreased levels of plasma glucose, insulin, and triglyceride, the effect of which on hyperglycemia was similar to diet restriction. To examine how drinking H-2-water improves obesity and metabolic parameters at the molecular level, we examined gene-expression profiles, and found enhanced expression of a hepatic hormone, fibroblast growth factor 21 (FGF21), which functions to enhance fatty acid and glucose expenditure. Indeed, H-2 stimulated energy metabolism as measured by oxygen consumption. The present results suggest the potential benefit of H-2 in improving obesity, diabetes, and metabolic syndrome.

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  • Molecular hydrogen protects chondrocytes from oxidative stress and indirectly alters gene expressions through reducing peroxynitrite derived from nitric oxide 査読

    Teruyasu Hanaoka, Naomi Kamimura, Takashi Yokota, Shinro Takai, Shigeo Ohta

    Medical Gas Research   1 ( 1 )   18   2011年

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:BioMed Central Ltd.  

    Background: Molecular hydrogen (H&lt
    inf&gt
    2&lt
    /inf&gt
    ) functions as an extensive protector against oxidative stress, inflammation and allergic reaction in various biological models and clinical tests
    however, its essential mechanisms remain unknown. H&lt
    inf&gt
    2&lt
    /inf&gt
    directly reacts with the strong reactive nitrogen species peroxynitrite (ONOO&lt
    sup&gt
    -&lt
    /sup&gt
    ) as well as hydroxyl radicals (OH), but not with nitric oxide radical (NO). We hypothesized that one of the H &lt
    inf&gt
    2&lt
    /inf&gt
    functions is caused by reducing cellular ONOO&lt
    sup&gt
    -&lt
    /sup&gt
    , which is generated by the rapid reaction of NO with superoxides (O&lt
    inf&gt
    2&lt
    /inf&gt
    &lt
    sup&gt
    -&lt
    /sup&gt
    ). To verify this hypothesis, we examined whether H&lt
    inf&gt
    2&lt
    /inf&gt
    could restore cytotoxicity and transcriptional alterations induced by ONOO &lt
    sup&gt
    -&lt
    /sup&gt
    derived from NO in chondrocytes. Methods. We treated cultured chondrocytes from porcine hindlimb cartilage or from rat meniscus fibrecartilage with a donor of NO, S-nitroso-N-acetylpenicillamine (SNAP) in the presence or absence of H&lt
    inf&gt
    2&lt
    /inf&gt
    . Chondrocyte viability was determined using a LIVE/DEAD Viability/Cytotoxicity Kit. Gene expressions of the matrix proteins of cartilage and the matrix metalloproteinases were analyzed by reverse transcriptase-coupled real-time PCR method. Results: SNAP treatment increased the levels of nitrated proteins. H&lt
    inf&gt
    2&lt
    /inf&gt
    decreased the levels of the nitrated proteins, and suppressed chondrocyte death. It is known that the matrix proteins of cartilage (including aggrecan and type II collagen) and matrix metalloproteinases (such as MMP3 and MMP13) are down- and up-regulated by ONOO&lt
    sup&gt
    -&lt
    /sup&gt
    , respectively. H&lt
    inf&gt
    2&lt
    /inf&gt
    restoratively increased the gene expressions of aggrecan and type II collagen in the presence of H&lt
    inf&gt
    2&lt
    /inf&gt
    . Conversely, the gene expressions of MMP3 and MMP13 were restoratively down-regulated with H&lt
    inf&gt
    2&lt
    /inf&gt
    . Thus, H&lt
    inf&gt
    2&lt
    /inf&gt
    acted to restore transcriptional alterations induced by ONOO&lt
    sup&gt
    -&lt
    /sup&gt
    . Conclusions: These results imply that one of the functions of H&lt
    inf&gt
    2&lt
    /inf&gt
    exhibits cytoprotective effects and transcriptional alterations through reducing ONOO&lt
    sup&gt
    -&lt
    /sup&gt
    . Moreover, novel pharmacological strategies aimed at selective removal of ONOO&lt
    sup&gt
    -&lt
    /sup&gt
    may represent a powerful method for preventive and therapeutic use of H&lt
    inf&gt
    2&lt
    /inf&gt
    for joint diseases. © 2011 Hanaoka et al
    licensee BioMed Central Ltd.

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  • Cardioprotective effect of intermittent fasting is associated with an elevation of adiponectin levels in rats 査読

    Ruiqian Wan, Ismayil Ahmet, Martin Brown, Aiwu Cheng, Naomi Kamimura, Mark Talan, Mark P. Mattson

    JOURNAL OF NUTRITIONAL BIOCHEMISTRY   21 ( 5 )   413 - 417   2010年5月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ELSEVIER SCIENCE INC  

    It has been reported that dietary energy restriction, including intermittent fasting (IF), can protect heart and brain cells against injury and improve functional outcome in animal models of myocardial infarction (MI) and stroke. Here we report that IF improves glycemic control and protects the myocardium against ischemia-induced cell damage and inflammation in rats. Echocardiographic analysis of heart structural and functional variables revealed that IF attenuates the growth-related increase in posterior ventricular wall thickness, end systolic and diastolic volumes, and reduces the ejection fraction. The size of the ischemic infarct 24 h following permanent ligation of a coronary artery was significantly smaller, and markers of inflammation (infiltration of leukocytes in the area at risk and plasma IL-6 levels) were less, in IF rats compared to rats on the control diet. IF resulted in increased levels of circulating adiponectin prior to and after MI. Because recent studies have shown that adiponectin can protect the heart against ischemic injury, our findings suggest a potential role for adiponectin as a mediator of the cardioprotective effect of IF. Published by Elsevier Inc.

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  • Molecular hydrogen alleviates nephrotoxicity induced by an anti-cancer drug cisplatin without compromising anti-tumor activity in mice 査読

    Naomi Nakashima-Kamimura, Takashi Mori, Ikuroh Ohsawa, Sadamitsu Asoh, Shigeo Ohta

    CANCER CHEMOTHERAPY AND PHARMACOLOGY   64 ( 4 )   753 - 761   2009年9月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:SPRINGER  

    Cisplatin is a widely used anti-cancer drug in the treatment of a wide range of tumors; however, its application is limited by nephrotoxicity, which is affected by oxidative stress. We have reported that molecular hydrogen (H(2)) acts as an efficient antioxidant (Ohsawa et al. in Nat Med 13:688-694, 2007). Here we show that hydrogen efficiently mitigates the side effects of cisplatin by reducing oxidative stress.
    Mice were administered cisplatin followed by inhaling hydrogen gas (1% H(2) in air). Furthermore, instead of inhaling hydrogen gas, we examined whether drinking water containing hydrogen (hydrogen water; 0.8 mM H(2) in water) is applicable by examining oxidative stress, mortality, and body-weight loss. Nephrotoxicity was assessed by morphological changes, serum creatinine and blood urea nitrogen (BUN) levels.
    Inhalation of hydrogen gas improved mortality and body-weight loss caused by cisplatin, and alleviated nephrotoxicity. Hydrogen was detected in blood when hydrogen water was placed in the stomach of a rat. Consuming hydrogen water ad libitum also reduced oxidative stress, mortality, and body-weight loss induced by cisplatin in mice. Hydrogen water improved metamorphosis accompanying decreased apoptosis in the kidney, and nephrotoxicity as assessed by serum creatinine and BUN levels. Despite its protective effects against cisplatin-induced toxicity, hydrogen did not impair anti-tumor activity of cisplatin against cancer cell lines in vitro and tumor-bearing mice in vivo.
    Hydrogen has potential for improving the quality of life of patients during chemotherapy by efficiently mitigating the side effects of cisplatin.

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  • Consumption of Molecular Hydrogen Prevents the Stress-Induced Impairments in Hippocampus-Dependent Learning Tasks during Chronic Physical Restraint in Mice 査読

    Kazufumi Nagata, Naomi Nakashima-Kamimura, Toshio Mikami, Ikuroh Ohsawa, Shigeo Ohta

    NEUROPSYCHOPHARMACOLOGY   34 ( 2 )   501 - 508   2009年1月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:NATURE PUBLISHING GROUP  

    We have reported that hydrogen (H(2)) acts as an efficient antioxidant by gaseous rapid diffusion. When water saturated with hydrogen ( hydrogen water) was placed into the stomach of a rat, hydrogen was detected at several mu M level in blood. Because hydrogen gas is unsuitable for continuous consumption, we investigated using mice whether drinking hydrogen water ad libitum, instead of inhaling hydrogen gas, prevents cognitive impairment by reducing oxidative stress. Chronic physical restraint stress to mice enhanced levels of oxidative stress markers, malondialdehyde and 4-hydroxy-2-nonenal, in the brain, and impaired learning and memory, as judged by three different methods: passive avoidance learning, object recognition task, and the Morris water maze. Consumption of hydrogen water ad libitum throughout the whole period suppressed the increase in the oxidative stress markers and prevented cognitive impairment, as judged by all three methods, whereas hydrogen water did not improve cognitive ability when no stress was provided. Neural proliferation in the dentate gyrus of the hippocampus was suppressed by restraint stress, as observed by 5-bromo-2'-deoxyuridine incorporation and Ki-67 immunostaining, proliferation markers. The consumption of hydrogen water ameliorated the reduced proliferation although the mechanistic link between the hydrogen-dependent changes in neurogenesis and cognitive impairments remains unclear. Thus, continuous consumption of hydrogen water reduces oxidative stress in the brain, and prevents the stress-induced decline in learning and memory caused by chronic physical restraint. Hydrogen water may be applicable for preventive use in cognitive or other neuronal disorders.

    DOI: 10.1038/npp.2008.95

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  • Prevention of chemotherapy-induced alopecia by the anti-death FNK protein 査読

    Naomi Nakashima-Kamimura, Kiyomi Nishimaki, Takashi Mori, Sadamitsu Asoh, Shigeo Ohta

    LIFE SCIENCES   82 ( 3-4 )   218 - 225   2008年1月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:PERGAMON-ELSEVIER SCIENCE LTD  

    Many anticancer drugs attack rapidly dividing cells, including not only malignant cells but also hair follicle cells, and induce alopecia. Chemotherapy-induced alopecia (CIA) is an emotionally distressing side effect of cancer chemotherapy. There is currently no useful preventive therapy for CIA. We have previously constructed anti-death rFNK protein from rat Bcl-x(L) by site-directed mutagenesis to strengthen cytoprotective activity. When fused to the protein transduction domain (PTD) of HIV/Tat, the fusion protein PTD (TAT)-rFNK successfully entered cells from the outside in vitro and in vivo to exhibit anti-death activity against apoptosis and necrosis. Here, we show that topical application of FNK protected against CIA in a newborn rat model. The protective activity against hair-loss was observed in 30-1000 nM TAT-rFNK administrative groups in a dose-dependent manner. Furthermore, a human version of FNK (hFNK) fused to other PTD peptides exhibited a protective ability. These results suggest that PTD-FNK possesses protective activity against CIA and is not restricted to a sequence of PTD peptides or species of FNK. Thus, PTD-FNK represents potential to develop a useful method for preventing CIA in cancer patients. (c) 2007 Elsevier Inc. All rights reserved.

    DOI: 10.1016/j.lfs.2007.11.011

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  • Compensatory change of interacting amino acids in the coevolution of transcriptional coactivator MBF1 and TATA-box-binding protein 査読

    Qing-Xin Liu, Naomi Nakashima-Kamimura, Kazuho Ikeo, Susumu Hirose, Takashi Gojobori

    MOLECULAR BIOLOGY AND EVOLUTION   24 ( 7 )   1458 - 1463   2007年7月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:OXFORD UNIV PRESS  

    To elucidate the transcriptional regulation in eukaryotic genome network, it is important to understand coevolution of transcription factors, transcriptional coactivators, and TATA-box-binding protein (TBP). In this study, coevolution of transcriptional coactivator multiprotein-bridging factor 1 and its interacting target TBP was first evaluated experimentally by examining if compensatory amino acid changes took place at interacting sites of both proteins. The experiments were conducted by identifying interaction sites and comparing the amino acids at these sites among different organisms. Here, we provide evidence for compensatory changes of transcription coactivator and its interacting target, presenting the 1st report that transcription coactivator may have undergone coevolution with TBP.

    DOI: 10.1093/molbev/msm073

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  • MIDAS/GPP34, a nuclear gene product, regulates total mitochondrial mass in response to mitochondrial dysfunction 査読

    N Nakashima-Kamimura, S Asoh, Y Ishibashi, Y Mukai, Y Shidara, H Oda, K Munakata, Y Goto, S Ohta

    JOURNAL OF CELL SCIENCE   118 ( 22 )   5357 - 5367   2005年11月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:COMPANY OF BIOLOGISTS LTD  

    To investigate the regulatory system in mitochondrial biogenesis involving crosstalk between the mitochondria and nucleus, we found a factor named MIDAS (mitochondrial DNA absence sensitive factor) whose expression was enhanced by the absence of mitochondrial DNA (mtDNA). In patients with mitochondrial diseases, MIDAS expression was increased only in dysfunctional muscle fibers. A majority of MIDAS localized to mitochondria with a small fraction in the Golgi apparatus in HeLa cells. To investigate the function of MIDAS, we stably transfected HeLa cells with an expression vector carrying MIDAS cDNA or siRNA. Cells expressing the MIDAS protein and the siRNA constitutively showed an increase and decrease in the total mass of mitochondria, respectively, accompanying the regulation of a mitochondria-specific phospholipid, cardiolipin. In contrast, amounts of the mitochondrial DNA, RNA and proteins did not depend upon MMAS. Thus, MIDAS is involved in the regulation of mitochondrial lipids, leading to increases of total mitochondrial mass in response to mitochondrial dysfunction.

    DOI: 10.1242/jcs.02645

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  • Fidelity of DNA polymerase delta holoenzyme from Saccharomyces cerevisiae: The sliding clamp proliferating cell nuclear antigen decreases its fidelity 査読

    K Hashimoto, K Shimizu, N Nakashima, A Sugino

    BIOCHEMISTRY   42 ( 48 )   14207 - 14213   2003年12月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:AMER CHEMICAL SOC  

    DNA polymerases delta and epsilon (pol delta and epsilon) are the two major replicative polymerases in the budding yeast Saccharomyces cerevisiae. The fidelity of pol delta is influenced by its 3'-5' proofreading exonuclease activity, which corrects misinsertion errors, and by enzyme cofactors. PCNA is a pol delta cofactor, called the sliding clamp, which increases the processivity of pol delta holoenzyme. This study measures the fidelity of 3'-5' exonuclease-proficient and -deficient pol delta holoenzyme using a synthetic 30mer primer/ 100mer template in the presence and absence of PCNA. Although PCNA increases pol delta processivity, the presence of PCNA decreased pol delta fidelity 2-7-fold. In particular, wild-type pol delta demonstrated the following nucleotide substitution efficiencies for mismatches in the absence of PCNA: G(.)G, 0.728 x 10(-4); T(.)G, 1.82 x 10(-4); A(.)G, <0.01 x 10(-4). In the presence of PCNA these values increased as follows: G(.)G, 1.30 x 10(-4); T(.)G, 2.62 x 10(-4); A(.)G, 0.074 x 10(-4). A similar but smaller effect was observed for exonuclease-deficient pol delta (i.e., 2-4-fold increase in nucleotide substitution efficiencies in the presence of PCNA). Thus, the fidelity of wild-type pol delta in the presence of PCNA is more than 2 orders of magnitude lower than the fidelity of wild-type pol is holoenzyme and is comparable to the fidelity of exonuclease-deficient pol epsilon holoenzyme.

    DOI: 10.1021/bi0348359

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  • The DNA polymerase domain of pole is required for rapid, efficient, and highly accurate chromosomal DNA replication, telomere length maintenance, and normal cell senescence in Saccharomyces cerevisiae 査読

    T Ohya, Y Kawasaki, SI Hiraga, S Kanbara, K Nakajo, N Nakashima, A Suzuki, A Sugino

    JOURNAL OF BIOLOGICAL CHEMISTRY   277 ( 31 )   28099 - 28108   2002年8月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC  

    Saccharomyces cerevisiae POL2 encodes the catalytic subunit of DNA polymerase epsilon. This study investigates the cellular functions performed by the polymerase domain of Pol2p and its role in DNA metabolism. The pol2-16 mutation has a deletion in the catalytic domain of DNA polymerase a that eliminates its polymerase and exonuclease activities. It is a viable mutant, which displays temperature sensitivity for growth and a defect in elongation step of chromosomal DNA replication even at permissive temperatures. This mutation is synthetic lethal in combination with temperature-sensitive mutants or the 3'- to 5'-exonuclease-deficient mutant of DNA polymerase delta in a haploid cell. These results suggest that the catalytic activity of DNA polymerase a participates in the same pathway as DNA polymerase delta, and this is consistent with the observation that DNA polymerases delta and epsilon colocalize in some punctate foci on yeast chromatids during S phase. The pol2-16 mutant senesces more rapidly than wild type strain and also has shorter telomeres. These results indicate that the DNA polymerase domain of Po12p is required for rapid, efficient, and highly accurate chromosomal DNA replication in yeast.

    DOI: 10.1074/jbc.M111573200

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  • The fifth essential DNA polymerase phi in Saccharomyces cerevisiae is localized to the nucleolus and plays an important role in synthesis of rRNA 査読

    K Shimizu, Y Kawasaki, SI Hiraga, M Tawaramoto, N Nakashima, A Sugino

    PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA   99 ( 14 )   9133 - 9138   2002年7月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:NATL ACAD SCIENCES  

    We report that POL5 encodes the fifth essential DNA polymerase in Saccharomyces cerevisiae. Pol5p was identified and purified from yeast cell extracts and is an aphidicolin-sensitive DNA polymerase that is stimulated by yeast proliferating cell nuclear antigen (PCNA). Thus, we named Pol5p DNA polymerase phi. Temperature-sensitive pol5-1similar to-3 mutants did not arrest at G(2)/M at the restrictive temperature. Furthermore, the polymerase active-site mutant POL5dn gene complements the lethality of Deltapol5. These results suggest that the polymerase activity of Pol5p is not required for the in vivo function of Pol5p. rRNA synthesis was severely inhibited at the restrictive temperature in the temperature-sensitive pol5-3 mutant cells, suggesting that an essential function of Pol5p is rRNA synthesis. Pol5p is localized exclusively to the nucleolus and binds near or at the enhancer region of rRNA-encoding DNA repeating units.

    DOI: 10.1073/pnas.142277999

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  • DNA polymerase epsilon encoded by cdc20(+) is required for chromosomal DNA replication in the fission yeast Schizosaccharomyces pombe 査読

    A Sugino, T Ohara, J Sebastian, N Nakashima, H Araki

    GENES TO CELLS   3 ( 2 )   99 - 110   1998年2月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:WILEY  

    Background: DNA polymerase II (PolII), the homologue of mammalian DNA polymerase epsilon, is essential for chromosomal DNA replication in the budding yeast Saccharomyces cerevisiae and also participates in S-phase checkpoint control. An important issue is whether chromosomal DNA replication in other eukaryotes, including the fission yeast Schizosaccharomyces pombe-in which the characteristics of replication origins are poorly defined-also requires DNA polymerase E. It has been shown that DNA polymerase epsilon is not required for the in vitro replication of SV40 DNA by human cell extracts.
    Results: We have cloned and sequenced S. pombe pol2(+), which is identical to the cell-cycle gene cdc20(+), encoding the catalytic polypeptide of DNA polymerase epsilon (Pol epsilon). The predicted amino acid sequence of Pol epsilon is highly homologous to that of S. cerevisiae PolII and human Pol epsilon. Consistent with this, the Pol epsilon polypeptide was recognized by polyclonal antibodies against S. cerevisiae PolII holoenzyme (PolII(star)). The terminal morphology of cells containing the disrupted pol2 gene was similar to that of DNA replication mutant cells and cdc20 mutant cells. Furthermore, the Pol epsilon activity from temperature-sensitive S. pombe cdc20 mutant cells was temperature-sensitive, and chromosomal DNA replication in the mutant cells was inhibited at the restrictive temperatures.
    Conclusion: These data strongly suggest that Pol epsilon is required for normal chromosomal DNA replication in S. pombe, as is PolII in S. cerevisiae. Thus, eukaryotic chromosomal DNA is replicated differently from that of viral SV40 DNA.

    DOI: 10.1046/j.1365-2443.1998.00169.x

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  • The second subunit of DNA polymerase III (delta) is encoded by the HYS2 gene in Saccharomyces cerevisiae 査読

    K Hashimoto, N Nakashima, T Ohara, S Maki, A Sugino

    NUCLEIC ACIDS RESEARCH   26 ( 2 )   477 - 485   1998年1月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:OXFORD UNIV PRESS  

    DNA polymerase III (delta) of Saccharomyces cerevisiae is purified as a complex of at least two polypeptides with molecular masses of 125 and 55 kDa as judged by SDS-PAGE. In this paper we determine partial amino acid sequences of the 125 and 55 kDa polypeptides and find that they match parts of the amino acid sequences predicted from the nucleotide sequence of the CDC2 and HYS2 genes respectively, We also show by Western blotting that Hys2 protein co-purifies with DNA polymerase III activity as well as Cdc2 polypeptide. The complex form of DNA polymerase III activity could not be detected in thermosensitive hys2 mutant cell extracts, although another form of DNA polymerase III was found, This form of DNA polymerase III, which could also be detected in wild-type extracts, was not associated with Hys2 protein and was not stimulated by addition of proliferating cell nuclear antigen (PCNA), replication factor A (RF-A) or replication factor C (RF-C), The temperature-sensitive growth phenotype of hys2-1 and hys2-2 mutations could be suppressed by the CDC2 gene on a multicopy plasmid, These data suggest that the 55 kDa polypeptide encoded by the HYS2 gene is one of the subunits of DNA polymerase III complex in S.cerevisiae and is required for highly processive DNA synthesis catalyzed by DNA polymerase III in the presence of PCNA, RF-A and RF-C.

    DOI: 10.1093/nar/26.2.477

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  • Cell cycle control in fission yeast and mammals: Identification of new regulatory mechanisms 査読

    H Okayama, A Nagata, S Jinno, H Murakami, K Tanaka, N Nakashima

    ADVANCES IN CANCER RESEARCH, VOL 69   69   17 - 62   1996年

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    記述言語:英語   出版者・発行元:ACADEMIC PRESS INC  

    DOI: 10.1016/s0065-230x(08)60859-3

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  • FISSION YEAST REP2 IS A PUTATIVE TRANSCRIPTIONAL ACTIVATOR SUBUNIT FOR THE CELL-CYCLE START FUNCTION OF RES2-CDC1O 査読

    N NAKASHIMA, K TANAKA, S STURM, H OKAYAMA

    EMBO JOURNAL   14 ( 19 )   4794 - 4802   1995年10月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:WILEY  

    In the yeast cell cycle 'start' requires sets of the Cdc10/ SWI family of transcriptional factors which activate the MCB cis elements contained in genes essential for S phase progression. Fission yeast possess two such overlapping systems, Res1-Cdc10 and Res2-Cdc10, both of which act to start the mitotic and meiotic cycles, We have recently isolated rep2(+) as a multicopy suppressor of a temperature-sensitive cdc10 mutant which encodes a zinc finger protein. Here we show that the Rep2 zinc finger protein is an essential component of the active Res2-Cdc10 transcriptional regulator complex and likely to play a role in the control of cell cycle 'start'. Our data suggest that Rep2 is a transcriptional activator subunit which interacts with the MCB binding subunit complex formed by Res2 and Cdc10.

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  • HAC1 - A NOVEL YEAST BZIP PROTEIN-BINDING TO THE CRE MOTIF IS A MULTICOPY SUPPRESSOR FOR CDC10 MUTANT OF SCHIZOSACCHAROMYCES-POMBE 査読

    H NOJIMA, SH LEEM, H ARAKI, A SAKAI, N NAKASHIMA, Y KANAOKA, Y ONO

    NUCLEIC ACIDS RESEARCH   22 ( 24 )   5279 - 5288   1994年12月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:OXFORD UNIV PRESS UNITED KINGDOM  

    We cloned by phenotypic complementation a novel Saccharomyces cerevisiae's multicopy suppressor of the Schizosaccharomyces pombe cdc10-129 mutant which we call HAC1, an acronym of 'homologous to ATF/CREB 1'. It encodes a bZIP (basic-leucine zipper) protein of 230 amino acids with close homology to the mammalian ATF/CREB transcription factor and gel-retardation assays showed that it binds specifically to the CRE motif. HAC1 is not essential for viability. However, the had disruptant becomes caffeine sensitive, which is suppressed by multicopy expression of the yeast PDE2 (Phosphodiesterase 2) gene. Although the mRNA level of HAC1 is almost constitutive throughout the cell cycle, it fluctuates during meiosis. The upstream region of the HAC1 gene contains a T4C site, a URS (upstream repression sequence) and a TR (T-rich) box-like sequence, which reside upstream of many meiotic genes. These results suggest that HAC1 may also be one of the meiotic genes.

    DOI: 10.1093/nar/22.24.5279

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  • YOLK VITRONECTIN - PURIFICATION AND DIFFERENCES FROM ITS BLOOD HOMOLOG IN MOLECULAR-SIZE, HEPARIN BINDING, COLLAGEN BINDING, AND BOUND CARBOHYDRATE 査読

    Y NAGANO, T HAMANO, N NAKASHIMA, M ISHIKAWA, K MIYAZAKI, M HAYASHI

    JOURNAL OF BIOLOGICAL CHEMISTRY   267 ( 34 )   24863 - 24870   1992年12月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC  

    This is the first report on a unique vitronectin molecule, yolk vitronectin, which is similar to its blood homologue in cell spreading activity but different in molecular size, bound carbohydrate, and heparin and collagen binding activity. Yolk vitronectin was purified 2,500-fold from chick egg yolk by a combination of hydroxylapatite, DEAE-cellulose, and anti-vitronectin-Sepharose column chromatographies. In SDS-polyacrylamide gel electrophoresis under reducing conditions, yolk vitronectin was separated into 54- and 45-kDa bands, which are 16 and 25 kDa smaller, respectively, than the 70-kDa major band of chick blood vitronectin. The 54-kDa band shares the same NH2-terminal sequence as chick blood vitronectin. In contrast, the NH2-terminal sequence of the 45-kDa band is somewhat homologous with the internal sequences of mammalian vitronectins beginning at the 50th amino acid from the NH2 terminus. The bound carbohydrate of the 54- and 45-kDa species of yolk vitronectin is similar to, but distinct from, that of blood vitronectin. Unlike blood vitronectin, yolk vitronectin cannot bind to either heparin or collagen.

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  • VITRONECTIN DIVERSITY IN EVOLUTION BUT UNIFORMITY IN LIGAND-BINDING AND SIZE OF THE CORE POLYPEPTIDE 査読

    N NAKASHIMA, K MIYAZAKI, M ISHIKAWA, T YATOHGO, H OGAWA, H UCHIBORI, MATSUMOTO, I, N SENO, M HAYASHI

    BIOCHIMICA ET BIOPHYSICA ACTA   1120 ( 1 )   1 - 10   1992年3月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ELSEVIER SCIENCE BV  

    We isolated vitronectins from the plasma or sera of 14 animal species including mouse and rat by heparin affinity chromatography. They cross-reacted with anti-vitronectin antibody and their amino terminal sequences showed strong homology. They also promoted spreading of BHK cells and were bound to heparin and collagen in the same way. Therefore, these properties appear to be essential for vitronectin function. However, the apparent molecular weights of these vitronectins varied considerably from 59 to 78 kDa in sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). In addition, the number of bands also varied from 1 to 3. To search for the uniformity of vitronectin polypeptide, vitronectins were deglycosylated and examined by Ferguson plot analysis. The size of the polypeptide portion of vitronectins was estimated to range from 40 to 57 kDa which was 19-26 kDa smaller than original values. Supposing a possible cleavage site at 5-13 kDa far from the carboxyl terminus, all vitronectin polypeptides were speculated to be synthesized de novo in the size range of 50-57 kDa. Proteins reacting with anti-vitronectin antibody were also detected on the immunoblot of 13 more species including Drosophila and Physarum. Almost all of these vitronectin-like proteins showed marked species-specific variations in their apparent molecular weights from 51 to 96 kDa in SDS-PAGE.

    DOI: 10.1016/0167-4838(92)90417-c

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▼全件表示

MISC

  • 血中のPD-1結合能を有する可溶性PD-L1 を用いた非小細胞肺癌の 免疫チェックポイント阻害薬の効果予測

    柏田 健, 西槇 貴代美, 上村 尚美, 清家 正博, 弦間 昭彦, 岩井 佳子

    第78回日本癌学会総会   2019年9月

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  • PD-1結合能を有する可溶性PD-L1(sPD-L1)を検出するELISA系を用いた、非小細胞肺癌への免疫チェックポイント阻害剤の効果予測(Soluble PD-L1 with PD-1-binding capacity as a biomarker for anti-PD-1/PD-L1 therapy for non-small cell lung cancer)

    柏田 建, 西槇 貴代美, 上村 尚美, 清家 正博, 弦間 昭彦, 岩井 佳子

    日本癌学会総会記事   78回   P - 2309   2019年9月

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    記述言語:英語   出版者・発行元:日本癌学会  

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  • 青色光照射後の酸化ストレスによるマウス網膜組織への影響

    横田 隆, Alexander Wolf, 上村 尚美, 小原澤 英彰, 五十嵐 勉, 高橋 浩, 太田 成男

    生命科学系学会合同年次大会   2017年度   [2P - 1035]   2017年12月

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    記述言語:日本語   出版者・発行元:生命科学系学会合同年次大会運営事務局  

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  • in vivo酸化ストレスモニターマウスを用いた糖尿病モデルマウスの酸化ストレス測定と分子状水素の効果

    上村尚美, WOLF Alexander, 西槙貴代美, 横田隆, 一宮治美, 井内勝哉, 太田成男

    日本抗加齢医学会総会プログラム・抄録集   17th   2017年

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  • ペルオキシナイトライト産生酸化ストレス傷害に対する水素分子(H2)のラット網膜保護効果

    横田 隆, 上村 尚美, 五十嵐 勉, 高橋 浩, 小原澤 英彰, 太田 成男

    日本生化学会大会・日本分子生物学会年会合同大会講演要旨集   88回・38回   [2P1207] - [2P1207]   2015年12月

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    記述言語:日本語   出版者・発行元:(公社)日本生化学会  

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  • Response to Letter Regarding Article, "Hydrogen Inhalation During Normoxic Resuscitation Improves Neurological Outcome in a Rat Model of Cardiac Arrest Independently of Targeted Temperature Management"

    Kei Hayashida, Motoaki Sano, Naomi Kamimura, Takashi Yokota, Masaru Suzuki, Shigeo Ohta, Keiichi Fukuda, Shingo Hori

    CIRCULATION   132 ( 11 )   E148 - E148   2015年9月

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    記述言語:英語   掲載種別:速報,短報,研究ノート等(学術雑誌)   出版者・発行元:LIPPINCOTT WILLIAMS & WILKINS  

    DOI: 10.1161/CIRCULATIONAHA.115.016785

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  • 分子状水素はフリーラジカル連鎖反応で生じる脂質メディエーターを調節して遺伝子発現を制御する

    井内勝哉, 井本明美, 井本明美, 西槙貴代美, 一宮治美, LEE Hyunjin, 横田隆, 上村尚美, 太田成男

    日本生化学会大会(Web)   88th   2015年

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  • TBHPを用いた酸化ストレス誘導性の細胞死に対する分子状水素の保護作用

    井内勝哉, 井本明美, 井本明美, 西槙貴代美, 一宮治美, 李げんしん, 横田隆, 上村尚美, 太田成男

    日本Cell Death学会学術集会プログラム抄録集   24th   2015年

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  • アルツハイマーモデルマウスに対する骨髄単核球移植の認知機能改善効果(第2報)

    金丸 拓也, 上村 尚美, 井内 勝哉, 西槙 貴代美, 横田 隆, 高見 新也, 赤芝 洋紀, 志鷹 義嗣, 桂 研一郎, 太田 成男, 片山 泰朗

    臨床神経学   54 ( Suppl )   S135   2014年12月

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    記述言語:日本語   掲載種別:会議報告等  

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  • Inhalation of H2 Gas Starting After Resuscitation Under Normoxia Improves Neurological Outcomes in a Rat Cardiac Arrest Model

    Kei Hayashida, Motoaki Sano, Naomi Kamimura, Takashi Yokota, Masaru Suzuki, Shigeo Ohta, Keiichi Fukuda, Shingo Hori

    CIRCULATION   130   2014年11月

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    記述言語:英語   掲載種別:研究発表ペーパー・要旨(国際会議)   出版者・発行元:LIPPINCOTT WILLIAMS & WILKINS  

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  • 血管内皮細胞p53の抑制は食餌性肥満における代謝異常を改善する

    横山 真隆, 岡田 将, 中込 敦士, 森谷 純治, 野島 愛佳, 小林 欣夫, 清水 逸平, 吉田 陽子, 南野 徹, 一宮 治美, 上村 尚美, 太田 成男, Fruttiger Marcus, Lozano Guillermina

    代謝異常治療研究基金研究業績集   41   21 - 30   2014年1月

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    記述言語:日本語   出版者・発行元:(一財)代謝異常治療研究基金  

    血管内皮細胞p53の抑制は食餌性肥満における代謝異常を改善するか検討した。野生型マウスに高脂肪高蔗糖食を投与して食餌性肥満モデルを作製し、大動脈・肺/骨格筋の血管内皮細胞を評価した。これらのマウスを用いて標本切片の染色・蛋白抽出やRNA抽出による分子発現確認を行った。次に血管内皮細胞p53の役割を評価するために血管内皮細胞特異的p53ノックアウトマウスを作製した。高カロリー食負荷によって血管内皮細胞でのGlut1発現がp53活性化に伴って減少し、この変化がp53ノックアウトによって消失するとともに骨格筋への糖取り込みが亢進した。p53はPTEN並びにGlut1の発現を調節することで糖代謝に関与していることが示唆された。

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  • ミトコンドリア活性酸素の実時間計測,酸化ストレス亢進マウスの作製,新概念の抗酸化物質としての水素

    太田成男, 上村尚美, WOLF Alexander M., 井内勝哉, 西槙貴代美, 一宮治美, 横田隆, 中嶋裕也

    基礎老化研究   38 ( 3 )   2014年

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  • Alzheimerモデルマウスに対する骨髄単核球移植の認知機能改善効果

    金丸 拓也, 上村 尚美, 井内 勝哉, 西槇 貴代美, 横田 隆, 高見 新也, 赤芝 洋紀, 志鷹 義嗣, 桂 研一郎, 太田 成男, 片山 泰朗

    臨床神経学   53 ( 12 )   1483   2013年12月

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    記述言語:日本語   掲載種別:会議報告等  

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  • Inhalation of H2 in the Absence of Hyperoxia Starting after Rosc Improves Neurologic Outcomes and Survival in a Rat Model Following Resuscitation from Cardiac Arrest

    Kei Hayashida, Motoaki Sano, Naomi Kamimura, Takashi Yokota, Shigeo Ohta, Keiichi Fukuda, Shingo Hori

    CIRCULATION   128 ( 22 )   2013年11月

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    記述言語:英語   掲載種別:研究発表ペーパー・要旨(国際会議)   出版者・発行元:LIPPINCOTT WILLIAMS & WILKINS  

    Web of Science

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  • Alzheimer病モデルマウスに対する骨髄単核球移植の認知機能改善効果

    金丸 拓也, 上村 尚美, 井内 勝哉, 西槇 貴代美, 横田 隆, 高見 新也, 赤芝 洋紀, 志鷹 義嗣, 桂 研一郎, 太田 成男, 片山 泰朗

    神経治療学   30 ( 5 )   685   2013年9月

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    記述言語:日本語   掲載種別:会議報告等  

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  • アルツハイマー病モデルマウスに対する骨髄単核球移植の予防・治療効果

    上村尚美, 金丸拓也, 金丸拓也, 横田隆, 井内勝哉, 西槙貴代美, 高見新也, 赤芝洋紀, 志鷹義嗣, 桂研一郎, 片山泰朗, 太田成男

    日本分子生物学会年会プログラム・要旨集(Web)   36th   2013年

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  • ヒト変異APP高発現マウスと酸化ストレス亢進マウスとの掛け合わせマウスの解析

    上村尚美, 金丸拓也, 金丸拓也, 横田隆, 井内勝哉, 西槙貴代美, 高見新也, 赤芝洋紀, 志鷹義嗣, 桂研一郎, 片山泰朗, 太田成男

    日本分子生物学会年会プログラム・要旨集(Web)   35th   2012年

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  • アルツハイマーモデルマウスに対する他家骨髄単核球投与の認知機能改善効果

    金丸拓也, 金丸拓也, 上村尚美, 井内勝哉, 西槇貴代美, 横田隆, 高見新也, 赤芝洋紀, 志鷹義嗣, 桂研一郎, 片山泰朗, 太田成男

    日本分子生物学会年会プログラム・要旨集(Web)   35th   2012年

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  • 脂肪細胞における転写因子KLF15の過剰発現はSCD1発現を抑制し、インスリン分泌を増加させる

    永礼 智基, 阪上 浩, 松本 道宏, 曹 永恒, 酒井 真志人, 稲垣 健二郎, 松木 泰, 渡辺 英二郎, 池田 和貴, 田口 良, 上村 尚美, 太田 成男, 平松 隆司, 春日 雅人

    肥満研究   17 ( Suppl. )   140 - 140   2011年9月

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    記述言語:日本語   出版者・発行元:(一社)日本肥満学会  

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▼全件表示

共同研究・競争的資金等の研究課題

  • 糖尿病に伴う免疫機能低下の分子メカニズムの解明

    研究課題/領域番号:20K11541  2020年4月 - 2023年3月

    日本学術振興会  科学研究費助成事業  基盤研究(C)

    上村 尚美

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    配分額:4290000円 ( 直接経費:3300000円 、 間接経費:990000円 )

    糖尿病では自然免疫や獲得免疫に変化が起こり易感染性となり重症化しやすいことが知られている。易感染性の原因としては、好中球や単球・マクロファージなどの食細胞の機能低下、細胞性免疫反応の低下が多く報告されているが、免疫機能の低下におけるミトコンドリアの役割は未だ不明な部分が多い。本研究課題では、糖尿病モデルマウスを用いて、各種免疫担当細胞における免疫応答時のミトコンドリア機能を測定し、糖尿病に伴う免疫機能の低下の分子メカニズムを明らかにすることを目標としている。当研究室にて開発した酸化ストレスモニタリング糖尿病マウスを用いて、全身の様々な臓器の酸化還元状態を解析したところ、脾臓やリンパ節が糖尿病モデルマウスにおいて最も変化していることが明らかとなった。そこで、免疫細胞にターゲットを絞り、免疫細胞の表面マーカーを染め分けることにより、各種免疫担当細胞における酸化還元状態を測定し、糖尿病モデルマウスにおいてはT細胞の酸化還元状態が最も大きく変化していることが明らかとなった。T細胞にはサブセットがあり,新規の抗原に応答するナイーブ細胞から抗原特異的に機能を発揮するエフェクター細胞、そして、記憶した抗原に応答するメモリー細胞へと分化する.これらの細胞の割合は一定のバランスで保たれているが,免疫系の異常によりこのバランスが崩れることが考えられる。本研究では、T細胞のサブセット解析とミトコンドリア活性解析を組み合わせて糖尿病マウスの解析を実施した。

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  • 水素分子の炎症制御機構解析-慢性炎症を基盤とした生活習慣病対策に向けて-

    2017年4月 - 2020年3月

    日本学術振興会  科研費・基盤研究(C) 

    上村 尚美

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    担当区分:研究代表者  資金種別:競争的資金

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  • 水素分子の糖尿病改善効果と遺伝子発現誘導における作用機序の解明

    2014年4月 - 2017年3月

    日本学術振興会  科研費・基盤研究(C) 

    上村 尚美

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    担当区分:研究代表者  資金種別:競争的資金

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  • 健康増進と疾病予防に寄与する分子状水素の多様な機能を発揮するメカニズムの解明

    研究課題/領域番号:26282198  2014年4月 - 2017年3月

    日本学術振興会  科学研究費助成事業  基盤研究(B)

    太田 成男, 上村 尚美, ウォルフ アレクサンダー, 井内 勝哉, 西槙 貴代美, 一宮 治美

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    配分額:15600000円 ( 直接経費:12000000円 、 間接経費:3600000円 )

    分子状水素(H2)は、様々な細胞内情報伝達調節と遺伝子発現制御によって、健康増進・疾患の予防に寄与する。本研究では、H2がどのように遺伝子発現を制御するメカニズムを解明することを目的とする。
    フリーラジカル連鎖反応にH2は介入して、酸化リン脂質を改変し、Ca(2+)シグナリングを通して遺伝子発現を制御することを明らかにした。これに加えて、H2は、PGC-1α遺伝子発現増加を促し、脂肪酸とステロイド代謝を亢進する。メカニズムとして、H2が4-ヒドロキシ-2-ノネナールを減少させ、Akt/FoxO1シグナリングとその一連のシグナリングを通して、PGC-1αは間接的に制御される。

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  • 放射線内部被曝による遺伝子損傷を水素が軽減する。

    研究課題/領域番号:24651055  2012年4月 - 2014年3月

    日本学術振興会  科学研究費助成事業  挑戦的萌芽研究

    太田 成男, 上村 尚美, ウォルフ アレクサンダー, 西槙 貴代美, 一宮 治美, 横田 隆

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    配分額:4160000円 ( 直接経費:3200000円 、 間接経費:960000円 )

    放射線によって ヒドロキシルラジカルが生じ、それがトリッガーとなってラジカル連鎖反応を生じさせ、主に細胞膜において細胞障害をあたえることが知られている。低濃度の水素は、ラジカル反応誘発剤による細胞障害も抑制したので、水素は少量でも脂質ラジカルを抑制することにより連鎖反応を抑制して細胞を保護することを明らかにした。さらに、低い水素濃度でも、細胞膜の脂質過酸化を抑制することを明らかにした。
    本研究では、放射線障害を水素が抑制する可能性を示唆し、その分子機構の一端を明らかにしたが、それをそのまま社会に適用するためには不十分である。

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  • 生体内酸化ストレスの定量的評価システムを用いた水素分子による糖尿病改善効果の解析

    2011年4月 - 2014年3月

    日本学術振興会  科研費・基盤研究(C) 

    上村 尚美

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    担当区分:研究代表者  資金種別:競争的資金

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  • 新規水素発生素材の経口投与による水素分子の老年病と生活習慣病の予防効果

    研究課題/領域番号:23300257  2011年4月 - 2014年3月

    日本学術振興会  科学研究費助成事業  基盤研究(B)

    太田 成男, 上村 尚美, ウォルフ アレクサンダー, 西槙 貴代美, 一宮 治美, 横田 隆

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    配分額:17290000円 ( 直接経費:13300000円 、 間接経費:3990000円 )

    MgH2は水素吸蔵金属であり、水素分子を発生する。MgH2をマウスに経口投与し、まず安全性を確認した。MgH2投与により、2型糖尿病モデルマウスの血中の中性脂肪を効果的に低下させた。この原因を探るべくマイクロアレイにより網羅的に遺伝子発現の変動を調べた。すると脂質代謝、コレステロール代謝に関与する遺伝子の発現が水素によって増加し、時間的に遺伝子発現の変動を調べると、ミトコンドリアの生成制御を司るPGC-1αが上昇して、その後にミトコンドリアの脂質代謝の関与する酵素の遺伝子発現が上昇した。以上の結果より、水素発生素材は生活習慣病の予防に効果的であることが示唆された。

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  • カロリー制限によるミトコンドリア機能制御機構の解明

    研究課題/領域番号:22590814  2010年 - 2012年

    日本学術振興会  科学研究費助成事業  基盤研究(C)

    新村 健, 末松 誠, 福田 恵一, 太田 成男, 坪田 一男, 足立 健, 佐野 元昭, 上村 尚美

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    配分額:4680000円 ( 直接経費:3600000円 、 間接経費:1080000円 )

    カロリー制限(以下CR)は、強力な虚血心筋保護効果を発揮する。我々は、CRは特定のミトコンドリア蛋白の脱アセチル化修飾を介して虚血ストレス時の活性酸素種産出を軽減し、心保護効果を発揮する可能性を見出した。このミトコンドリア蛋白修飾は、sirtuin familyによりもたらされていると推測された。次に我々は、心筋細胞特異的SIRT1欠損マウスを作製し、CR効果の発現には心筋細胞のSIRT1が必須であることを明らかにした。

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  • 糖尿病の予防・改善における水素の効果

    2008年4月 - 2011年3月

    日本学術振興会  科研費・基盤研究(C) 

    上村 尚美

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    担当区分:研究代表者  資金種別:競争的資金

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  • 新しい概念の抗酸化物質である水素を摂取することによる生活習慣病予防への展開

    研究課題/領域番号:20300230  2008年 - 2010年

    日本学術振興会  科学研究費助成事業  基盤研究(B)

    太田 成男, 大澤 郁朗, 上村 尚美

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    配分額:19240000円 ( 直接経費:14800000円 、 間接経費:4440000円 )

    生活習慣病の原因のひとつは酸化ストレスであり、酸化ストレス軽減によって、生活習慣病の改善と予防が期待される。水素分子は、新しい概念の抗酸化物質であり、生活習慣病への予防効果が期待される。本研究では、認知症モデルマウス、動脈硬化モデルマウス、糖尿病・高脂血症モデル動物に水素分子を溶解した水を自由摂取させることにより、その改善効果と予防効果があることを明らかにした。

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  • 発がん時におけるミトコンドリア遺伝子体細胞変異の蓄積によるがん増殖促進機構

    研究課題/領域番号:18012045  2006年 - 2007年

    日本学術振興会  科学研究費助成事業  特定領域研究

    太田 成男, 大澤 郁朗, 上村 尚美

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    配分額:10900000円 ( 直接経費:10900000円 )

    大部分のがん細胞のミトコンドリアDNA(mtDNA)には、体細胞変異が蓄積している。発がん初期段階でmtDNAに変異が生じると変異mtDNAと正常mtDNAが混在した状態から、細胞内で変異mtDNAだけの状態に移行し、ついで変異mtDNAだけをもつ細胞のみの集団に移行する.本研究の目的は、(1)発がんにおける過程におけるmtDNA体細胞変異の蓄積の分子機構を明らかにする。(2)発がん時における変異mtDNAが原因のアポトーシス抑制機構を明らかにする。(3)ミトコンドリア機能が低下するにもかかわらず、細胞増殖が促進される機構を明らかにする。
    患者のがん組織のミトコンドリアDNAの全塩基配列を決定し、がん細胞と正常細胞のミトコンドリアDNAの配列の違いを比較し、抗癌剤耐性との相関関係を調べ、正の相関関係があることを明らかにした。また、抗癌剤耐性の細胞株のミトコンドリアDNA塩基配列を決定し、そのミトコンドリアDNAを別細胞に移植し、抗癌剤耐性が消失することから抗癌剤耐性はミトコンドリアDNAに存在することを明確にした。
    さらに抗癌剤耐性細胞を作り出し、その60%にはミトコンドリアDNAの変異が生じており、ミトコンドリアを移植する方法によって抗癌剤耐性が消失することから、これもミトコンドリアに抗癌剤耐性の原因があることを明確にした。
    抗癌剤はアポトーシスを誘導するので、ミトコンドリアDNAの変異によってアポトーシスが阻害され、がん細胞にミトコンドリアDNAの変異が蓄積することを明確にした。さらに、ミトコンドリア機能が低下することと相関していることを明らかにした。乳酸が上昇しているので、ミトコンドリア機能を代償するために解糖系が亢進していることを明らかにした。

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  • エネルギー代謝低下による神経細胞終末分化促進機構の解明

    研究課題/領域番号:17500263  2005年 - 2007年

    日本学術振興会  科学研究費助成事業  基盤研究(C)

    大澤 郁朗, 上村 尚美, 太田 成男

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    配分額:3670000円 ( 直接経費:3400000円 、 間接経費:270000円 )

    神経幹細胞におけるエネルギー代謝の一時的抑制が神経細胞への終末分化に必須であるとする仮説を検証することが本研究の目的である。今までに複数のヒト神経芽細胞でTCAサイクルの主要酵素であるジヒドロリポアミド・サクシニル転移酵素(DLST)に変異があり、エネルギー代謝が低下し、その低下が神経芽細胞の分化に必須であることを突き止めてきた。低下抑制は細胞死を促進する。さらに培養過程で神経細胞へと分化可能な細胞とグリア様の形態をとる細胞が混在してくる神経芽細胞SH-SY5Yについて、ミトコンドリア膜電位依存的に蛍光強度が増加するTMRMで染色し経時的に観察した。神経細胞へと分化可能な細胞はTMRMによる染色性が弱く、一方でグリア様の形態をとる細胞はTMRMの染色性が高いまま分裂を繰り返した。この結果は、グリア細胞へと分化する細胞が神経細胞へと分化する細胞に比べてエネルギー産生が高いことを示している。実際にラット胎仔脳をミトコンドリア膜電位依存的蛍光色素MitoTracker Redで染色した結果、増殖中の神経幹細胞(nestin陽性)から分化した神経細胞(TUJ1陽性)に移行する過程で、細胞の移動と共にミトコンドリア膜電位の一過的低下が認められた。これはエネルギー代謝の低下がin vivoでも起こっていることを示している。近年、ATP低下により生じるAMPで活性化されるAMPキナーゼの活性化が神経分化に必要なことが報告された。この点について解析中である。また、酸化ストレスによる神経細胞死を水素分子が抑制することも見いだした。

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  • 発癌時におけるミトコンドリア遺伝子体細胞変異に蓄積による核遺伝子発現制御

    研究課題/領域番号:17013079  2005年

    日本学術振興会  科学研究費助成事業  特定領域研究

    太田 成男, 宮戸 靖幸, 大澤 郁朗, 上村 尚美

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    配分額:5400000円 ( 直接経費:5400000円 )

    (1)癌細胞におけるミトコンドリアDNAの体細胞変異の蓄積
    多くの癌組織、癌細胞のmtDNAに体細胞変異が蓄積していることが明らかにされている。しかし、この体細胞変異の蓄積が、癌の形成過程の二次的結果として生じているのか、癌形成の原因のひとつとして、癌の促進に関与したために変異mtDNAをもつ癌細胞が多くなったのか、明らかではなかった。
    (2)サイブリドを用いたmtDNAの役割の研究
    細胞には核ゲノムとミトコンドリアゲノムが共存しているので、mtDNAの役割を明らかにするためには、核が共通でmtDNAだけが異なる細胞を比較しなければならない。そこで、mtDNAを消失しているHeLa細胞と脱核した細胞質を融合し、核が共通で正常mtDNAをもつ細胞と変異mtDNAをもつ細胞を作製した。この融合細胞を細胞質の融合であるのでサイブリド(cybrid)と呼ぶ。このサイブリドを用いて、mtDNAの癌の増殖速度へ対する効果とアポトーシ耐性効果、抗癌剤への耐性効果を調べた。
    (3)癌の増殖に対する変異mtDNAの効果
    変異mtDNAを持つサイブリド細胞と正常mtDNAもつサイブリド細胞をヌードマウスに移植すると、移植直後からの腫瘍体積の増加が正常mtDNAをもつサイブリド細胞より速く、mtDNA変異が癌増殖促進に寄与していることが示された。変異mtDNAをもつサイブリドでは、自発的におきるアポトーシス頻度が低下しており、アポトーシスの頻度の低下が見かけ上の増殖促進に寄与していることが示唆された。
    (4)抗癌剤へ対する耐性獲得とmtDNA変異
    mtDNA変異によってアポトーシスが抑制されたので、抗癌剤への耐性へのmtDNAの役割をサイブリドを用いて解析した。変異mtDNAをもつサイブリドは正常mtDNAをもつサイブリドよりも抗癌剤耐性であった。

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  • 核遺伝子産物MIDASによるミトコンドリア増殖機構の解明

    2004年4月 - 2007年3月

    日本学術振興会  科研費・若手研究(B) 

    上村 尚美

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    担当区分:研究代表者  資金種別:競争的資金

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  • 細胞死抑制強化蛋白質の細胞内導入による脳梗塞治療法の開発

    研究課題/領域番号:16390257  2004年 - 2006年

    日本学術振興会  科学研究費助成事業  基盤研究(B)

    太田 成男, 桂 研一郎, 麻生 定光, 上村 尚美

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    配分額:14400000円 ( 直接経費:14400000円 )

    多くの方法が脳梗塞治療へ試みられてきたが、効果的な方法は見いだされていない。ここでは、細胞死抑制活性強化タンパク質FNKを細胞内導入ペプチドTATに接続して、脳梗塞による細胞死を抑制しようとした。TAT-FNKはアポトーシスだけでなくネクローシスも抑制し、広範な対象に効果的であることがわかった。さらに脳梗塞治療薬として期待されているFK506と組み合わせて投与するとさらに効果的であることがラットの中大動脈梗塞モデルを用いてわかった。すなわちTAT-FNK投与後、30分後にFK506を投与することが最も効果的だった。(1)皮質の梗塞体積は27%から14%まで減少した。(2)脳梗塞後1週間後も効果があった。(3)線条体を含む広い領域で効果があった。(4)脳梗塞開始4,5時間まで効果があった。(5)神経症状の効果が認められた。さらに、FK506との組み合わせが何故効果的なのかを分子レベルで解析し、カルシウムの動態を変化させることで副作用を軽減することを明らかにした。さらにFK506はTAT-FNKが細胞内に導入されるのを抑制するので同時に投与するよりも時間差をおいて投与した方が効果的であることもわかった。
    さらに、水素の吸引は極めて脳梗塞治療に効果的であることを見いだした。ヒドロキシルラジカルは最も強力な活性酸素種で核酸、脂質および蛋白と無差別に反応する。このヒドロキシルラジカルを解毒する機構は知られておらず、従って、ヒドロキシルラジカルを除去することが最も重要な抗酸化プロセスとなる。私たちは、生体内で水素分子(H2)が有効な抗酸化物質となりうることを見いだした。
    水素による効果とTAT-FNKの効果を組み合わせるとさらに効果的であると期待できる。

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