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

基本信息

批准号：
8708197
负责人：
Naomi Miriam Hamburg
金额：
$ 55.36万
依托单位：
BOSTON UNIVERSITY MEDICAL CAMPUS
依托单位国家：
美国
项目类别：
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/8708197
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 endothelial dysfunction healthy volunteer improved insight minimally invasive new therapeutic target novel novel strategies public health relevance radial artery response sedentary therapeutic target tool

项目摘要

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信号（包括营养过剩）的信号传导中发挥着重要作用。线粒体信号传导在很大程度上是通过电子传递链组件调节活性氧 (ROS) 的产生来介导的。生理信号传导依赖于通过解偶联蛋白 2 (UCP2) 对膜电位的控制，并通过线粒体裂变和融合之间的适当平衡来保持线粒体蛋白和 mtDNA 的完整性，以维持正常的线粒体网络（线粒体动力学）。肥胖与体内能量供需失衡有关。我们假设，长期能量过剩会造成 ROS 增加的恶性循环，引发线粒体碎片和 UCP-2 反应不足，进一步增加 ROS 并损害内皮功能。在这个项目中，我们将把一氧化氮信号传导和内皮依赖性血管舒张与从肥胖患者和暴露于两种人体能量过剩模型的健康志愿者中新鲜分离的动脉内皮细胞中线粒体功能的相关方面联系起来。我们的初步数据显示，从肥胖患者收集的内皮细胞中，eNOS 信号传导受损、UCP2 减少、线粒体断裂以及裂变蛋白 Fis1 增加。我们的项目有 3 个具体目标：对于目标 1，我们将从肥胖患者收集动脉内皮细胞，并测量线粒体 ROS、网络范围以及 UCP-2、Mfn2 和 Fis1 的表达，并将这些发现与内皮依赖性血管舒张联系起来。臂和新分离的细胞中的 eNOS 激活。我们还将确定沉默 Fis1 或过度表达 UCP-2 或 Mfn2 是否可以恢复 eNOS 激活。在目标 2 中，我们将确定动力学改变和 UCP-2 是否会导致脂质注射（能量过剩）引起的内皮功能障碍，在目标 3 中，我们将确定这些机制是否会导致卧床休息（能量需求减少）引起的内皮功能障碍。）。我们预计肥胖患者细胞中的 ROS 增加、网络碎片化、UCP2 减少和 eNOS 激活受损。如果 Intralipid 和卧床休息诱导肥胖内皮表型，并且如果过度表达 UCP-2 或沉默 Fis1 可以逆转内皮功能障碍，我们将有强有力的证据表明这些机制有助于人类肥胖中内皮功能障碍的发病机制。