Regulation of Muscle ATP Synthase Beta Subunit Metabolism in Obesity

肥胖中肌肉 ATP 合酶 β 亚基代谢的调节

• 批准号: 8304885
• 负责人: Christos S Katsanos
• 金额: $ 34.98万
• 依托单位: ARIZONA STATE UNIVERSITY-TEMPE CAMPUS
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-09-04 至 2016-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8304885
• 关键词: Acute; Adenosine Triphosphate; Aerobic Exercise; Amino Acids; Anabolism; Bioenergetics; Biopsy; Catalytic Domain; Cell physiology; Development; Effectiveness of Interventions; Exercise; F1-ATPase; Goals; High Pressure Liquid Chromatography; Human; Individual; Infusion procedures; Insulin Resistance; Intervention; Intravenous; Knowledge; Label; Lead; Leucine; Mass Fragmentography; Mass Spectrum Analysis; Measurement; Measures; Messenger RNA; Metabolic; Metabolism; Mitochondria; Mitochondrial Proteins; Muscle; Muscle Mitochondria; Muscle Proteins; Non obese; Obesity; Outcome; Oxidative Stress; Peptides; Physical activity; Physiological; Plasma; Production; Protein Biosynthesis; Proteins; Qualifying; Reactive Oxygen Species; Regulation; Research; Role; Saline; Sampling; Skeletal Muscle; Stimulus; Testing; Time; Translating; base; improved; in vivo; lifestyle intervention; muscle metabolism; protein degradation; protein expression; protein metabolism; sound; stable isotope; tandem mass spectrometry

DESCRIPTION (provided by applicant): Obesity is associated with reduced adenosine triphosphate (ATP) turnover in skeletal muscle. This condition results in unfavorable outcomes, proposed to range from decreased capacity for physical activity, to impaired activation of physiological mechanisms associated with cell function, to increased oxidative stress and the development of insulin resistance. The abundance of the beta subunit of the ATP synthase (¿ -F1-ATPase) in muscle mitochondria is decreased in obese, insulin-resistant individuals. ¿ -F1- ATPase makes up the catalytic site of the ATP synthase, and it is a rate-limiting component of ATP synthesis. We propose that muscle ¿ -F1-ATPase synthesis is reduced in obesity. Because measurement of stable isotopic enrichment of individual proteins is not practical using traditional gas chromatography-mass spectrometry approaches for proteins that are found in small amounts in skeletal muscle, we have developed an approach to quantify the isotopic enrichment of in vivo labeled muscle ¿ -F1-ATPase using HPLC-ESI-MS/MS. It is based on the quantification of the isotopic enrichment of a unique peptide of muscle ¿ -F1-ATPase. Using this approach we will test the hypothesis that the rate of muscle ¿ -F1-ATPase synthesis is reduced in obese individuals. We also intend to investigate the effects of increased plasma amino acid concentrations as well as exercise on stimulating the synthesis rate of ¿ -F1-ATPase in skeletal muscle of both obese and non-obese individuals. Muscle ¿ -F1-ATPase synthesis, which is the main end-point of this proposal, will be determined using an intravenous constant infusion of d9-leucine in obese and non-obese subjects, and by measuring the d9-leucine enrichment of a ¿ -F1-ATPase peptide. The following conditions will be tested: saline infusion (control), amino acid infusion, aerobic exercise, and a combination of aerobic exercise with amino acid infusion. These studies will for the first time determinate the rate of synthesis of muscle ¿ -F1-ATPase in humans in vivo, and how it is altered by interventions known to promote muscle protein anabolism. Overall, the results of these studies will lead to better understanding of the mechanisms regulating the abundance of ¿ -F1-ATPase in skeletal muscle in both obese and non-obese individuals. Further, they will provide scientific knowledge to base lifestyle interventions to improve muscle ATP turnover in obese individuals. PUBLIC HEALTH RELEVANCE: Obesity is associated with reduced adenosine triphosphate (ATP) turnover in skeletal muscle, a condition that can impair muscle metabolism. The proposed research will discover mechanisms responsible for decreased content in the protein ¿ -F1-ATPase, which is directly responsible for ATP assembly in skeletal muscle, and also examine the effectiveness of interventions to increase the rate of production of ¿ -F1-ATPase in skeletal muscle. This is important in order to develop appropriate interventions to improve muscle metabolism in obese individuals.

描述（由申请人提供）：肥胖与骨骼肌中三磷酸腺苷（ATP）周转减少有关。这种情况会导致不利的结果，包括身体活动能力下降，与细胞功能相关的生理机制激活受损，氧化应激增加和胰岛素抵抗的发展。在肥胖、胰岛素抵抗的个体中，肌肉线粒体中ATP合成酶β亚基（¿- f1 -ATP酶）的丰度降低。- f1 - ATP酶是ATP合成酶的催化位点，是ATP合成的限速组分。我们提出肌肉- f1 - atp酶合成在肥胖中减少。由于使用传统的气相色谱-质谱法测量骨骼肌中少量蛋白质的稳定同位素富集是不切实际的，因此我们开发了一种使用HPLC-ESI-MS/MS来量化体内标记肌肉¿- f1 - atp酶的同位素富集的方法。它是基于定量的同位素富集的独特肽的肌肉¿- f1 - atp酶。使用这种方法，我们将测试肥胖个体肌肉- f1 - atp酶合成速率降低的假设。我们还打算研究增加血浆氨基酸浓度以及运动对刺激肥胖和非肥胖个体骨骼肌中¿- f1 - atp酶合成速率的影响。肌肉¿- f1 - atp酶合成，这是本建议的主要终点，将通过在肥胖和非肥胖受试者中静脉持续输注d9-亮氨酸，并通过测量- f1 - atp酶肽的d9-亮氨酸富集来确定。将测试以下条件：生理盐水输注（对照）、氨基酸输注、有氧运动和有氧运动与氨基酸输注的组合。这些研究将首次确定人体体内肌肉- f1 - atp酶的合成速率，以及它如何被已知的促进肌肉蛋白质合成代谢的干预所改变。总的来说，这些研究的结果将有助于更好地理解肥胖和非肥胖个体骨骼肌中¿- f1 - atp酶丰度的调节机制。此外，它们将为基础生活方式干预提供科学知识，以改善肥胖个体的肌肉ATP转换。