Connexin 43 gap junction dynamics in the diabetic heart

糖尿病心脏中的连接蛋白 43 间隙连接动态

• 批准号: 7615813
• 负责人: Joseph A. Palatinus
• 金额: $ 3.61万
• 依托单位: MEDICAL UNIVERSITY OF SOUTH CAROLINA
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-02-01 至 2014-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7615813
• 关键词: Arrhythmia; Arterioloscleroses; Binding; Blood Pressure; Cardiac; Cardiomyopathies; Cardiovascular system; Cessation of life; Connexin 43; Diabetes Mellitus; Dyes; Echocardiography; Electrocardiogram; Electron Microscopy; Energy Transfer; Exhibits; Functional disorder; Gap Junctions; Glucose; Heart; Heart Diseases; Hyperglycemia; Hypertension; Immunoprecipitation; In Vitro; Lead; Life; Maps; Membrane; Myocardial; Optics; Peptides; Phosphorylation; Physiological; Predisposition; Proteins; Recovery; Risk; Rodent Model; Testing; Tight Junctions; Ventricular Dysfunction; Western Blotting; cellular imaging; design; diabetic; diabetic patient; protein crosslink; sugar; voltage

SPACE PROVIDED. Diabetic patients exhibit an increased risk of fatal arrhythmias, decreased recovery after a myocardial insult, and a cardiomyopathy leading to ventricular dysfunction independent of arteriolosclerosis and hypertension. The mechanism leading to cardiac dysfunction is not known, however, recent studies have suggested involvement of cardiac gap junction remodeling. Zonula occludens-1 (ZO-1) binds Connexin 43 (Cx43), and this interaction is important for gapjunction remodeling. It is hypothesized that the interaction of these two proteins is a major contributor to the lethal downstream physiological consequences including ventricular dysfunction and arrhythmias in the diabetic heart. This hypothesis will be tested through the following aims: 1 A. Determine whether Cx43 gap junction size and cellular distribution are altered in the ventricle of rodent models of diabetes in a manner that correlates with changes in ZO-1 Cx43 binding. 1B. Determine the extent to which diastolic dysfunction and susceptibility to inducible arrhythmia correlate with changes in ZO-1 Cx43 binding in the ventricle of rodent models of diabetes. 2A. Determine the extent to which hyperglycemia induced changes in Cx43 gap junction size, cellular distribution, and phosphorylation correlate with ZO-1 binding Cx43 in vitro. 2B. Determine if hyperglycemia induced remodeling of Cx43 gap junctions are normalized by a membrane permeant peptide (ACT-1) designed to inhibit the interaction of ZO-1 with Cx43 in vitro. Several approaches will be used including immuno-confocal colocalization analysis, Western blotting, FRET (fluorescent resonance energy transfer), immunoprecipitation, protein-protein crosslinking, and electron microscopy. In addition cardiac function will be assessed using electrocardiography, echocardiography and optical mapping of fluorescent voltage sensitive dyes. Additionally in Aim 2, live cell imaging of fluorescently tagged constructs of Cx43 and ZO-1 in high and low glucose conditions will also be performed. Eighty percent of diabetics in the US die of cardiovascular complications resulting in over 50000 deaths/year. This project will provide a better understanding of the fundamental mechanism of diabetic heart disease and may lead to new treatments beyond blood pressure and sugar control.

空间 假如。 糖尿病患者出现致命性心律失常的风险增加，心肌损伤后恢复速度减慢， 以及导致与动脉硬化和高血压无关的心室功能障碍的心肌病。 导致心脏功能障碍的机制尚不清楚，但最近的研究表明 参与心脏间隙连接重塑。小带闭塞-1 (ZO-1) 结合连接蛋白 43 (Cx43)，并且 这种相互作用对于间隙连接重塑很重要。据推测，这两者的相互作用 蛋白质是致命的下游生理后果（包括心室）的主要贡献者 糖尿病心脏功能障碍和心律失常。该假设将通过以下目标进行检验： 1 A. 确定 Cx43 间隙连接大小和细胞分布在心室中是否发生改变 以与 ZO-1 Cx43 结合变化相关的方式建立糖尿病啮齿动物模型。 1B.确定舒张功能障碍的程度和对诱发性心律失常的易感性 与糖尿病啮齿动物模型心室中 ZO-1 Cx43 结合的变化相关。 2A。确定高血糖引起 Cx43 间隙连接大小、细胞变化的程度 分布和磷酸化与体外 ZO-1 结合 Cx43 相关。 2B。确定高血糖诱导的 Cx43 间隙连接重塑是否通过 透膜肽 (ACT-1) 旨在体外抑制 ZO-1 与 Cx43 的相互作用。 将使用多种方法，包括免疫共聚焦共定位分析、蛋白质印迹、FRET （荧光共振能量转移）、免疫沉淀、蛋白质-蛋白质交联和电子 显微镜。此外，还将使用心电图、超声心动图和 荧光电压敏感染料的光学测绘。此外，在目标 2 中，活细胞成像 还将在高和低葡萄糖条件下进行 Cx43 和 ZO-1 的荧光标记构建体。 美国 80% 的糖尿病患者死于心血管并发症，导致超过 50000 人死亡 死亡人数/年。该项目将有助于更好地了解糖尿病的基本机制 心脏病，可能会导致血压和血糖控制之外的新治疗方法。