Mitochondrial Dynamics and UCP2 - Endothelial Dysfunction in Human Obesity

线粒体动力学和 UCP2 - 人类肥胖中的内皮功能障碍

• 批准号: 8583774
• 负责人: Joseph A. Vita
• 金额: $ 55.53万
• 依托单位: BOSTON UNIVERSITY MEDICAL CAMPUS
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-08-01 至 2018-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8583774
• 关键词: Acute; Agonist; Atherosclerosis; Bed rest; Behavioral; Blood Vessels; Boston; Cardiovascular Diseases; Cells; Chimeric Proteins; Chronic; Clinical Research; Collection; Complex; Cues; Data; Diabetes Mellitus; Electron Transport; Emulsions; Endothelial Cells; Endothelium; Epidemic; Equilibrium; Excision; Experimental Models; Exposure to; Fat emulsion; Functional disorder; Gene Expression; Genetic; Hormonal; Hour; Human; Individual; Infusion procedures; Intake; Intravenous; Life Style; Maintenance; Measurement; Measures; Mediating; Medical; Membrane; Membrane Potentials; Metabolic stress; Methodology; Mitochondria; Mitochondrial DNA; Mitochondrial Proteins; Modeling; Molecular; Nitric Oxide; Non obese; Nonesterified Fatty Acids; Nutrient; Obesity; Obesity associated cardiovascular disease; Overweight; Pathogenesis; Patients; Phenotype; Physiological; Play; Prevalence; Prevention; Process; Production; Protein Dynamics; Proteins; Protocols documentation; Reactive Oxygen Species; Role; Signal Transduction; Simulate; Triglycerides; UCP2 protein; Universities; Vasodilation; arm; atherogenesis; brachial artery; cell type; healthy volunteer; improved; insight; minimally invasive; new therapeutic target; novel; novel strategies; public health relevance; radial artery; response; sedentary; therapeutic target; tool; Acute; Agonist; Atherosclerosis; Bed rest; Behavioral; Blood Vessels; Boston; Cardiovascular Diseases; Cells; Chimeric Proteins; Chronic; Clinical Research; Collection; Complex; Cues; Data; Diabetes Mellitus; Electron Transport; Emulsions; Endothelial Cells; Endothelium; Epidemic; Equilibrium; Excision; Experimental Models; Exposure to; Fat emulsion; Functional disorder; Gene Expression; Genetic; Hormonal; Hour; Human; Individual; Infusion procedures; Intake; Intravenous; Life Style; Maintenance; Measurement; Measures; Mediating; Medical; Membrane; Membrane Potentials; Metabolic stress; Methodology; Mitochondria; Mitochondrial DNA; Mitochondrial Proteins; Modeling; Molecular; Nitric Oxide; Non obese; Nonesterified Fatty Acids; Nutrient; Obesity; Obesity associated cardiovascular disease; Overweight; Pathogenesis; Patients; Phenotype; Physiological; Play; Prevalence; Prevention; Process; Production; Protein Dynamics; Proteins; Protocols documentation; Reactive Oxygen Species; Role; Signal Transduction; Simulate; Triglycerides; UCP2 protein; Universities; Vasodilation; arm; atherogenesis; brachial artery; cell type; healthy volunteer; improved; insight; minimally invasive; new therapeutic target; novel; novel strategies; public health relevance; radial artery; response; sedentary; therapeutic target; tool

DESCRIPTION (provided by applicant): Recent studies have emphasized that mitochondria in endothelial cells play an important role in signaling in response to environmental cues, including nutrient excess. Mitochondrial signaling is mediated in large part by regulated production of reactive oxygen species (ROS) by components of the electron transport chain. Physiological signaling depends on control of membrane potential by uncoupling protein-2 (UCP2) and preserved integrity of mitochondrial proteins and mtDNA via an appropriate balance between mitochondrial fission and fusion to maintain normal mitochondrial networks (mitochondrial dynamics). Obesity is associated with an imbalance between energy supply and demand in the body. We hypothesize that chronic energy excess creates a vicious cycle of increased ROS that triggers mitochondrial fragmentation and an inadequate UCP-2 response that further increases ROS and impairs endothelial function. In this project, we will relate nitric oxide signaling and endothelium-dependent vasodilation to relevant aspects of mitochondrial function in freshly isolated arterial endothelial cells from obese patients and from healthy volunteers exposed to two human models of energy excess. Our preliminary data show impaired eNOS signaling, decreased UCP2, mitochondrial fragmentation, and an increase in the fission protein Fis1 in endothelial cells collected from obese patients. Our project has 3 specific aims: For Aim 1, we will collect arterial endothelial cells from obese patients and measure mitochondrial ROS, network extent, and expression of UCP-2, Mfn2, and Fis1 and relate the findings to endothelium- dependent vasodilation in the arm and to eNOS activation in the freshly isolated cells. We will also determine whether silencing Fis1 or over-expressing UCP-2 or Mfn2 restores eNOS activation. In Aim 2, we will determine whether altered dynamics and UCP-2 contribute to endothelial dysfunction induced by Intralipid infusion (energy excess), and in Aim 3, we will determine whether these mechanisms contribute to endothelial dysfunction induced by bed rest (decreased energy demand). We anticipate increased ROS, network fragmentation, decreased UCP2, and impaired eNOS activation in cells from obese patients. If Intralipid and bed rest induce an obese endothelial phenotype and if over- expressing UCP-2 or silencing Fis1 reverses endothelial dysfunction, we will have strong evidence that these mechanisms contribute to the pathogenesis of endothelial dysfunction in human obesity.

描述（由申请人提供）： 最近的研究强调，内皮细胞中的线粒体在响应环境线索（包括营养过量）的信号中起着重要作用。线粒体信号传导在很大程度上是通过电子传输链的组件对活性氧（ROS）的调节产生的。生理信号传导取决于通过解偶联蛋白2（UCP2）（UCP2）的控制以及线粒体蛋白和mTDNA的完整性，通过线粒体裂变和融合之间的适当平衡，以保持正常的线粒体网络（线粒体动力学）。肥胖与体内能量供应之间的不平衡有关。我们假设慢性能量过量产生了ROS增加的恶性循环，从而触发线粒体碎片和UCP-2不足的响应，从而进一步增加了ROS并损害内皮功能。在这个项目中，我们将将一氧化氮信号传导和内皮依赖性血管舒张与来自肥胖患者新鲜分离的动脉内皮细胞中线粒体功能的相关方面，以及来自健康的志愿者，暴露于两个人类的能量过量模型中。我们的初步数据显示，eNOS信号传导受损，UCP2降低，线粒体碎片化以及从肥胖患者收集的内皮细胞中裂变蛋白FIS1的增加。我们的项目具有3个特定目的：对于AIM 1，我们将收集来自肥胖患者的动脉内皮细胞，并测量UCP-2，MFN2和FIS1的线粒体ROS，网络范围以及表达，并将发现与内皮依赖的血管溶液相关联在臂中依赖于内新鲜分离的细胞中的eNOS和eNOS激活。我们还将确定沉默的FIS1或过表达UCP-2或MFN2是否会恢复ENOS激活。在AIM 2中，我们将确定动力学和UCP-2的改变是否有助于由脂质内输注引起的内皮功能障碍（能量过量），在AIM 3中，我们将确定这些机制是否有助于由床静电静电造成的内皮功能障碍（减少能量需求）。我们预计ROS增加，网络破碎，UCP2降低以及肥胖患者细胞中的ENOS激活受损。如果静脉内和床休息会诱导肥胖的内皮表型，如果过度表达UCP-2或沉默的FIS1逆转内皮功能障碍，我们将有强有力的证据表明，这些机制有助于人类肥胖症内皮功能障碍的发病机理。