Cellular and Molecular Mechanisms of Coronary Endothelial Dysfunction in Diabetes

糖尿病冠状动脉内皮功能障碍的细胞和分子机制

• 批准号: 8504541
• 负责人: Ayako Makino
• 金额: $ 37.96万
• 依托单位: UNIVERSITY OF ILLINOIS AT CHICAGO
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-07-03 至 2014-05-01
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8504541
• 关键词: 20 year old; Abnormal Endothelial Cell; Accounting; Apoptosis; Apoptotic; Attenuated; Binding; Blood Glucose; Blood Vessels; Blood capillaries; Blood flow; Ca(2+)-Transporting ATPase; Calcium-Activated Potassium Channel; Cardiac; Cardiac Myocytes; Categories; Cause of Death; Cell Death; Cell membrane; Cells; Communication; Complication; Coronary; Coronary artery; Coronary heart disease; Coupled; Data; Defect; Diabetes Mellitus; Diabetic Angiopathies; Diabetic Microangiopathies; Diabetic mouse; Disease; Down-Regulation; Endoplasmic Reticulum; Endothelial Cells; Endothelium; Functional disorder; Gap Junctions; Generations; Glucose; Grant; Heart; Hyperglycemia; Hyperlipidemia; Incidence; Individual; Injury; Ischemia; Ischemic Stroke; Lead; Left ventricular structure; Mediating; Membrane; Mitochondria; Molecular; Morbidity - disease rate; Myocardial Ischemia; Newly Diagnosed; Nitric Oxide Synthase; Nutrient; Organelles; Oxygen; Play; Post-Translational Protein Processing; Potassium Channel; Proteins; Pump; Regulation; Relaxation; Role; STIM1 gene; Signal Transduction; Site; Stroke; Testing; Transportation; United States; Vascular Endothelium-Dependent Relaxation; Vasodilation; Vasodilator Agents; base; capillary; cell type; connexin 40; density; design; diabetic; diabetic patient; extracellular; gap junction channel; insight; mortality; neuron loss; novel therapeutic intervention; overexpression; protein expression; sarcoplasmic reticulum calcium ATPase; sensor; vascular endothelial dysfunction

DESCRIPTION (provided by applicant): Coronary heart disease and ischemic stroke are the main causes of morbidity and mortality in diabetic patients. Endothelial injury and dysfunction are common starting points for diabetic angiopathy. It is thus important to investigate the cellula and molecular mechanisms involved in coronary vascular endothelial dysfunction in diabetes. Endothelial function is regulated by changes in cytosolic Ca2+ concentration ([Ca2+]cyt) in endothelial cells (ECs). [Ca2+]cyt is controlled by the Ca2+ mobilization from intracellular stores coupled to Ca2+ influx from the external medium. In ECs, the endoplasmic reticulum (ER) accounts for approximately 75% of the total intracellular Ca2+ stores and the [Ca2+] in the ER ([Ca2+]ER) determines in great part the generation of important Ca2+ signals. The objective of this study is to examine whether [Ca2+]ER is altered in diabetic ECs and how abnormal [Ca2+]ER leads to vascular endothelial dysfunction in diabetic heart. In Aim 1, we will examine whether and how the rise in [Ca2+]cyt due to Ca2+ release from the ER (indicative of the level of [Ca2+]ER) and [Ca2+]ER are attenuated in coronary ECs isolated from diabetic mice. The ER membrane constitutes Ca2+ pumps (sarco/endoplasmic reticulum Ca2+ ATPase (SERCA)) and several classes of intracellular Ca2+ releasing channels. Recently, stromal interaction molecule (STIM) was identified as an essential protein for the store-operated Ca2+ entry (SOCE) and a contributor to the Ca2+ refilling into the ER by interacting with SERCA on the ER membrane. In Aim 2, we will investigate the potential role of STIM1 in decreased [Ca2+]ER in diabetic coronary ECs. Our preliminary data show that SERCA3 and STIM1 protein expressions are markedly decreased in diabetic coronary ECs and STIM1 overexpression in diabetic coronary ECs significantly increases Ca2+ leak from the ER. In addition, Ca2+ transported to mitochondria from the ER plays a crucial role in cell apoptosis; increased mitochondrial Ca2+ ([Ca2+]mit) can trigger mitochondrial fragmentation, loss of mitochondrial integrity and cell death in many cell types. Our results show that [Ca2+]mit is significantly increased in coronary ECs in diabetes. In Aim 3, we will define whether Ca2+ transportation from the ER to mitochondria is increased in coronary ECs in diabetes and examine the role of the Ca2+ communication between the ER and mitochondria in endothelial dysfunction in diabetic heart. To examine Ca2+ handling by the ER in diabetic coronary ECs will further our understanding of pathophysiological aspects of coronary vascular complications in diabetes. Completion of this study will provide important insights into developing new therapeutic interventions for cardiac ischemia in diabetes.

描述（由申请人提供）：冠心病和缺血性卒中是糖尿病患者发病和死亡的主要原因。内皮损伤和功能障碍是糖尿病血管病变的常见起点。因此，研究糖尿病冠状动脉内皮功能障碍的细胞和分子机制具有重要意义。 内皮细胞功能受内皮细胞胞浆Ca 2+浓度（[Ca 2 +]cyt）变化的调节。[Ca2+]cyt受细胞内钙库的Ca 2+动员控制 与来自外部介质的Ca 2+流入偶联。在内皮细胞中，内质网（ER）约占细胞内钙库的75%，内质网中的[Ca 2 +]（[Ca 2 +]ER）在很大程度上决定了重要Ca 2+信号的产生。本研究的目的是检测糖尿病心脏内皮细胞[Ca 2 +]ER是否改变以及[Ca 2 +]ER异常如何导致血管内皮功能障碍。在目的1中，我们将研究在从糖尿病小鼠分离的冠状动脉EC中，由于ER释放的Ca 2+（指示[Ca 2 +]ER的水平）和[Ca 2 +]ER引起的[Ca 2 +]cyt的升高是否以及如何减弱。内质网膜由Ca ~（2+）泵（肌浆网/内质网Ca ~（2+）ATP酶（SERCA））和几类胞内Ca ~（2+）释放通道组成。近年来，基质相互作用分子（stromal interaction molecule，STIM）被认为是钙库操纵的钙内流（store-operated Ca 2 + entry，SOCE）的关键蛋白，并通过与内质网膜上的SERCA相互作用，促进钙内流。在目标2中，我们将研究STIM 1在糖尿病冠状动脉EC中[Ca 2 +]ER降低中的潜在作用。我们的初步数据显示，SERCA 3和STIM 1蛋白表达在糖尿病冠状动脉EC中显著降低，并且STIM 1在糖尿病冠状动脉EC中的过表达显著增加ER的Ca 2+渗漏。此外，从内质网转运到线粒体的Ca 2+在细胞凋亡中起着至关重要的作用;线粒体Ca 2+（[Ca 2 +]mit）增加可引发许多细胞类型中的线粒体片段化、线粒体完整性丧失和细胞死亡。我们的研究结果表明，[Ca 2 +]mit显着增加，在冠状动脉内皮细胞在糖尿病。在目标3中，我们将确定糖尿病冠状动脉EC中从ER到线粒体的Ca 2+转运是否增加，并检查ER和线粒体之间的Ca 2+通讯在糖尿病心脏内皮功能障碍中的作用。 研究糖尿病冠状动脉内皮细胞中内质网对钙离子的处理将进一步加深我们对糖尿病冠状动脉血管并发症病理生理方面的理解。这项研究的完成将为开发糖尿病心肌缺血的新治疗干预提供重要见解。