PGC-1 & Mitichondrial Dysfunction in Diabetes

PGC-1

基本信息

批准号：
7825317
负责人：
LAWRENCE J MANDARINO
金额：
$ 51.3万
依托单位：
ARIZONA STATE UNIVERSITY-TEMPE CAMPUS
依托单位国家：
美国
项目类别：
财政年份：
2004
资助国家：
美国
起止时间：
2004-02-01 至 2013-04-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7825317
关键词：
Accounting Bioenergetics Biogenesis Biopsy Complex Creatine Kinase Data Development Diabetes Mellitus Electron Transport Epidemic Etiology Euglycemic Clamping Exercise Functional disorder Gene Expression Genes Glucose Clamp Goals Hand Health Care Costs Human Immunoprecipitation In Vitro Individual Infusion procedures Insulin Insulin Resistance Lead Link Lipids Mass Spectrum Analysis Measurement Messenger RNA Mitochondria Mitochondrial Proteins Molecular Muscle Non-Insulin-Dependent Diabetes Mellitus Nuclear Obesity Patients Pattern Phosphorylation Pioglitazone Post-Translational Protein Processing Proteins Proteomics Regulation Research Resistance Respiration Respiratory physiology Rest Simulate Site Skeletal Muscle Techniques Testing clinically significant diabetic patient improved in vivo insight insulin sensitivity mRNA Expression mitochondrial dysfunction novel nrf1 protein public health relevance response

项目摘要

DESCRIPTION (provided by applicant): Our research in this project has focused on defining the changes in expression of nuclear encoded mitochondrial genes that predict changes in insulin sensitivity in skeletal muscle, with the goal of defining the molecular mechanisms underlying the connection between mitochondrial dysfunction and insulin resistance in skeletal muscle. We have found that lipid oversupply produced by a lipid infusion decreases mRNA expression of PGC-11, NRF-1, and nuclear encoded mitochondrial genes and induces insulin resistance. This was consistent with our original hypothesis that decreasing PGC-11 expression would result in lower expression of nuclear encoded mitochondrial genes and lead to mitochondrial dysfunction associated with insulin resistance. Additional studies showed a complex relationship between mitochondrial dysfunction, insulin sensitivity, and gene expression. Other data suggested that insulin resistant individuals could be exercise resistant. We also have shown that ATP synthase 2 is phosphorylated in vivo, and this may be regulated by insulin and altered in insulin resistance. Relatively little is known about changes in mitochondrial protein abundance or post-translational modification in insulin resistance, or their response to exercise or lipid oversupply. The overall goal of this proposal is to understand how underlying changes in regulation of mitochondrial respiration, protein abundance and phosphorylation contribute to mitochondrial dysfunction. To accomplish this goal, we will use glucose clamps, muscle biopsies, novel proteomics techniques for quantification of protein abundance changes, and in vitro mitochondrial respiration measurements using an energy clamp. We propose: 1. To determine whether mitochondrial isolated from insulin resistant human muscle have decreased respiration during conditions of increased energy demand simulated by a creatine kinase "energy clamp". 2. To determine how insulin resistance alters the pattern of abundance of mitochondrial proteins. 3. To determine how insulin resistance alters phosphorylation of proteins in the ETC. We will use immunoprecipitation and mass spectrometry analysis to quantify site-specific changes in phosphorylation of ETC proteins. 4. To determine whether insulin resistance is accompanied by "exercise resistance" with regard to mitochondrial biogenesis. 5. To determine whether experimental lipid oversupply decreases mitochondrial respiratory function. PUBLIC HEALTH RELEVANCE: Obesity and type 2 diabetes mellitus are increasing in epidemic proportion. Their complications account for up to forty percent of health care costs in the U.S. Despite this, the mechanisms responsible for their development remain unclear. This project will help to clarify these mechanisms on a molecular level. Given the clear evidence of a link to mitochondrial dysfunction in the etiology of obesity and insulin resistance, the studies are of high clinical significance and may provide useful new insights into the control of mitochondrial bioenergetics

描述（由申请人提供）：我们在该项目中的研究重点是定义核编码的线粒体基因表达的变化，该基因预测骨骼肌胰岛素敏感性的变化，目的是定义分子机制，从而定义了线粒体功能障碍与骨骼肌肉抑制线粒体功能障碍与骨骼肌肉抗性之间的联系。我们发现，脂质输注产生的脂质过度供应降低了PGC-11，NRF-1和核编码的线粒体基因的mRNA表达，并诱导胰岛素抵抗。这与我们最初的假设一致，即降低PGC-11的表达将导致核编码的线粒体基因的表达较低，并导致与胰岛素抵抗相关的线粒体功能障碍。其他研究表明，线粒体功能障碍，胰岛素敏感性和基因表达之间存在复杂的关系。其他数据表明，抗胰岛素耐药的个体可能具有耐药性。我们还表明，ATP合酶2在体内被磷酸化，这可能由胰岛素调节并改变胰岛素抵抗。关于线粒体蛋白丰度或胰岛素抵抗的翻译后修饰或对运动或脂质过度供应的反应的变化相对鲜为人知。该提案的总体目标是了解线粒体呼吸，蛋白质丰度和磷酸化调节的潜在变化有助于线粒体功能障碍。为了实现这一目标，我们将使用葡萄糖夹，肌肉活检，新颖的蛋白质组学技术来定量蛋白质丰度变化以及使用能量夹的体外线粒体呼吸测量。我们提出：1。确定在胰岛素耐药肌肉中分离出的线粒体是否在通过肌酸激酶“能量夹”模拟的能量需求增加的情况下减少了呼吸。 2。确定胰岛素抵抗如何改变线粒体蛋白的丰度。 3。确定胰岛素抵抗如何改变蛋白质的磷酸化。我们将使用免疫沉淀和质谱分析来量化ETC蛋白磷酸化的位点特异性变化。 4。确定胰岛素抵抗是否伴有有关线粒体生物发生的“运动抗性”。 5。确定实验性脂质过度供应是否降低线粒体呼吸功能。公共卫生相关性：肥胖和2型糖尿病的流行比例正在增加。他们的并发症占美国医疗保健成本的40％，尽管如此，导致其发展的机制仍不清楚。该项目将有助于在分子水平上阐明这些机制。鉴于明确的证据表明肥胖和胰岛素抵抗病因学中线粒体功能障碍有联系，研究具有很高的临床意义，可以为控制线粒体生物能的控制提供有用的新见解。