Role and Regulation of Skeletal Muscle Mitochondrial Dynamics in Type 2 Diabetes

骨骼肌线粒体动力学在 2 型糖尿病中的作用和调节

• 批准号: 9336293
• 负责人: JOHN P. KIRWAN
• 金额: $ 69.84万
• 依托单位: CLEVELAND CLINIC LERNER COM-CWRU
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-09-30 至 2018-04-01
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9336293
• 关键词: Acute; Attenuated; Bioenergetics; Biopsy; Cell model; Closure by clamp; Data; Diabetes Mellitus; Dictyostelium discoideum dynamin A; Disease; Dynamin; Euglycemic Clamping; Event; Exercise; Fatty acid glycerol esters; Functional disorder; Future Generations; Genus Hippocampus; High Pressure Liquid Chromatography; Human; Hydrogen Peroxide; Impairment; In Vitro; Indirect Calorimetry; Infusion procedures; Insulin; Insulin Resistance; Lead; Link; Lipids; Measures; Membrane; Membrane Potentials; Metabolism; Mitochondria; Molecular; Muscle; Muscle Cells; Muscle Fibers; Non obese; Non-Insulin-Dependent Diabetes Mellitus; Nonesterified Fatty Acids; Nutrient; OPA1 gene; Obesity; Organelles; PINK1 gene; Pathway interactions; Patients; Peripheral; Phosphorylation; Physiological; Prediabetes syndrome; Process; Production; Protein Isoforms; Proteins; Reactive Oxygen Species; Recruitment Activity; Regulation; Research; Reticulum; Role; Skeletal Muscle; Staining method; Stains; Structure; Testing; Thinness; Tissues; base; diabetes mellitus therapy; evidence base; exercise training; experimental study; expression cloning; glucose metabolism; glucose uptake; human disease; in vivo; innovation; insight; insulin sensitivity; insulin signaling; knock-down; lipid metabolism; man; metabolic phenotype; mitochondrial membrane; mitochondrial permeability transition pore; non-diabetic; novel; novel therapeutics; oxidation; prospective; protein expression; public health relevance; small hairpin RNA; tool; transmission process; volunteer

 DESCRIPTION (provided by applicant): The traditional view of mitochondria as isolated, spherical, energy producing organelles is undergoing a revolutionary transformation. Emerging data show that mitochondria form a dynamic networked reticulum that is regulated by cycles of fission and fusion. The discovery of a number of proteins that regulate these activities has led to important advances in understanding human disease. We have demonstrated that activation of dynamin related protein 1 (Drp1), a protein that controls mitochondrial fission, is reduced following exercise in prediabetes, and the decrease is linked to increased insulin sensitivity and fat oxidation. We now propose to build on this research and test the hypothesis that mitochondrial dynamics is a key mechanism of insulin resistance in type 2 diabetes. Our central hypothesis is that in diabetes elevated mitochondrial lipid metabolism causes recruitment and activation of Drp1 - likely through increased reactive oxygen species, leading to increased mitochondrial fragmentation and opening of the mitochondrial permeability transition pore. In Aim 1a we will perform in vivo and in vitro studies of human skeletal muscle mitochondrial dynamics across the metabolic phenotype ranging from patients with type 2 diabetes, to obese, to lean healthy controls. Translational first-in-man studies will use an acute lipid challenge (Aim 1b) and exercise training (Aim 1c) to investigate the physiological significance of altered skeleta muscle mitochondrial dynamics on insulin sensitivity in humans. Insulin resistance will be assessed using euglycemic hyperinsulinemic clamps, and in vivo substrate metabolism will be measured using indirect calorimetry. Mitochondrial fission/fusion, fragmentation, function, membrane potential, mitochondrial reactive oxygen species, and the accumulation of lipid intermediates will be assessed from muscle biopsy tissue and permeabilized muscle fibers. In Aim 2, we will use inhibition and expression cloning experiments to directly examine the impact of manipulating mitochondrial fragmentation in intact ex vivo cultured human skeletal muscle cells. This research will provide a comprehensive and complementary analysis of skeletal muscle mitochondrial dynamics, and will also generate novel data on the link between exercise and nutrient regulation of mitochondrial dynamics and function in type 2 diabetes. The experimental approach harnesses innovative molecular and cellular tools, interfaced with physiologically significant human studies to obtain meaningful data on insulin resistance, and has the potential to generate insights that will lead to new diabetes therapies for future generations.

 描述（由适用提供）：线粒体的传统观点是孤立的，球形的，能量产生的细胞器，正在经历革命性的转变。新兴数据表明，线粒体形成一个动态网络网状，受裂变和融合循环的调节。发现许多调节这些活动的蛋白质已导致 理解人类疾病的重要进展。我们已经证明，在糖尿病前期运动后，降低了动力蛋白相关蛋白1（DRP1）的激活，一种控制线粒体裂变的蛋白质，降低与胰岛素敏感性和脂肪氧化的增加有关。现在，我们建议以这项研究为基础，并检验以下假设：线粒体动力学是2型糖尿病中胰岛素抵抗的关键机制。我们的中心假设是，在糖尿病中，线粒体脂质代谢升高会导致DRP1的募集和激活 - 可能是通过增加的活性氧，从而导致线粒体碎片增加和线粒体通透性过渡孔的开放。在AIM 1A中，我们将在体内和体外研究人类骨骼肌线粒体动力学，跨代谢表型，从2型糖尿病患者到肥胖，到瘦健康控制。翻译第一名研究将使用急性脂质挑战（AIM 1B）和运动训练（AIM 1C），以研究骨骼肌肉线粒体动力学改变人类胰岛素敏感性的身体意义。将使用葡萄糖高胰岛素夹评估胰岛素耐药性，并将使用间接量热法测量体内底物代谢。线粒体裂变/融合，碎裂，功能，膜电位，线粒体活性氧以及脂质中间体的积累将从肌肉活检组织和透化肌纤维中进行评估。在AIM 2中，我们将使用抑制和表达克隆实验直接检查操纵线粒体碎片在完整的过时培养的人骨骼肌细胞中的影响。这项研究将对骨骼肌线粒体动力学进行全面而完整的分析，还将生成有关2型糖尿病中骨骼动力学和功能的运动与营养调节之间联系的新数据。实验方法利用创新的分子和细胞工具，干扰了物理上重要的人类研究，以获取有关胰岛素抵抗的有意义数据，并具有产生洞察力的潜力，这些见解将为子孙后代提供新的糖尿病疗法。