Mechanisms of regulation of mitochondrial H+ leak and thermogenesis

线粒体氢泄漏和产热的调节机制

• 批准号: 10277098
• 负责人: Ambre Marguerite Solange Bertholet
• 金额: $ 39万
• 依托单位: UNIVERSITY OF CALIFORNIA LOS ANGELES
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-08-01 至 2026-05-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10277098
• 关键词: 2,4-Dinitrophenol; Acute; Anti-Obesity Agents; Biological Assay; Body Temperature; Brown Fat; Burn injury; Calories; Cells; Cellular Metabolic Process; Chemical Actions; Chemicals; Development; Dinitrophenols; Disease; Equilibrium; Fatty acid glycerol esters; Homeostasis; Inner mitochondrial membrane; Ion Channel; Measurement; Mediator of activation protein; Metabolic; Metabolic syndrome; Metabolism; Methodology; Methods; Mitochondria; Modernization; Molecular; Nutrient; Patch-Clamp Techniques; Pathology; Physiology; Process; Production; Proteins; Protons; Reactive Oxygen Species; Regulation; Research Project Grants; Resolution; Techniques; Therapeutic; Thermogenesis; Time; Tissues; age related; base; biophysical properties; combat; diet-induced obesity; energy balance; insight; mitochondrial dysfunction; novel; oxidative damage; patch clamp; prevent; targeted treatment; therapeutic development; uncoupling protein 1

Project Summary Mitochondria control cell metabolism by converting nutrients into an electrochemical gradient of protons (H+) across the inner mitochondrial membrane (IMM) to generate ATP, the currency of the cell, and heat (called mitochondrial thermogenesis). A precise balance in the distribution of H+ between the two forms of energy production, ATP and heat, defines the metabolic homeostasis of the cell. Brown fat and beige fat mitochondria specialize in the production of heat via the uncoupling protein 1 (UCP1). However, even in other tissues, mitochondrial thermogenesis accounts for 25% of total mitochondrial energy production and can therefore have a considerable impact on the physiology of the entire body. Mitochondrial thermogenesis is not only essential for maintaining core body temperature, it is also the process by which excess calories are burned to prevent diet- induced obesity. In addition, it reduces the production of reactive oxygen species (ROS) by the mitochondria to protect cells from oxidative damage. In addition, chemical uncouplers such as 2,4-dinitrophenol (DNP), which are believed to increase H+ leak independently of proteins, are the most effective anti-obesity drugs to date. Thus, mitochondrial thermogenesis is a powerful regulator of cellular metabolism, and a mechanistic understanding of this fundamental process will help in the development of therapeutic strategies to combat many pathologies associated with mitochondrial dysfunction, including metabolic syndrome and age-related disorders. Unfortunately, the precise molecular mechanisms that control the acute activation of thermogenesis in the mitochondria are poorly defined. This lack of information is largely due to a dearth of methods for direct measurement of H+ currents across the IMM. The development of a methodology based on the patch-clamp technique allows for the first time the direct study of H+ leak through the IMM of each tissue and the first biophysical characterization of mitochondrial transporters, such as UCP1 and the ADP/ATP transporter (AAC), which are the mediators of this H+ leak. This unique approach now provides an unprecedented high- resolution direct functional analysis of 1) the mitochondrial ion channels and transporters responsible for mitochondrial thermogenesis and 2) the mechanisms of action of chemical uncouplers such as DNP. Using the new mitochondrial patch-clamp assay combined with modern cellular and molecular techniques, this research project will provide new insights into the mechanisms that control the thermogenic capacity of the mitochondria and how they can be targeted for therapeutic purposes.

项目概要 线粒体通过将营养物质转化为电化学梯度质子 (H+) 来控制细胞代谢 穿过线粒体内膜 (IMM) 以产生 ATP（细胞的货币）和热量（称为 线粒体产热作用）。两种能量形式之间 H+ 分布的精确平衡 ATP 和热量的产生决定了细胞的代谢稳态。棕色脂肪和米色脂肪线粒体 专门研究通过解偶联蛋白 1 (UCP1) 产生热量。然而，即使在其他组织中， 线粒体产热作用占线粒体总能量产生的 25%，因此可以 对整个身体的生理影响相当大。线粒体产热不仅对于 维持核心体温，也是燃烧多余热量以防止节食的过程- 诱发肥胖。此外，它还能减少线粒体产生的活性氧 (ROS) 保护细胞免受氧化损伤。此外，化学解偶联剂如 2,4-二硝基苯酚 (DNP)， 被认为可以独立于蛋白质增加 H+ 泄漏，是迄今为止最有效的抗肥胖药物。 因此，线粒体产热是细胞代谢的强大调节剂，也是一种机制。 了解这一基本过程将有助于制定治疗策略 对抗许多与线粒体功能障碍相关的疾病，包括代谢综合征 和与年龄有关的疾病。不幸的是，控制急性激活的精确分子机制 线粒体中的产热作用尚不清楚。这种信息的缺乏很大程度上是由于缺乏 直接测量 IMM 上 H+ 电流的方法。方法论的发展基于 膜片钳技术首次允许直接研究通过每个组织的 IMM 的 H+ 泄漏， 线粒体转运蛋白（例如 UCP1 和 ADP/ATP 转运蛋白）的首次生物物理表征 (AAC)，它们是 H+ 泄漏的介体。这种独特的方法现在提供了前所未有的高 1) 负责线粒体离子通道和转运蛋白的分辨率直接功能分析 线粒体生热作用和 2) 化学解偶联剂（如 DNP）的作用机制。使用 新的线粒体膜片钳测定结合现代细胞和分子技术，这 研究项目将为控制生热能力的机制提供新的见解 线粒体以及如何将它们用于治疗目的。