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: 8012855
• 负责人: Joseph A. Palatinus
• 金额: $ 3.9万
• 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/8012855
• 关键词: Animal Model; Arrhythmia; Arterioloscleroses; Binding; Blood Glucose; 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; Molecular; Myocardial; Optics; Peptides; Phosphorylation; Physiological; Predisposition; Proteins; Rattus; Recovery; Risk; Rodent Model; Severities; Streptozocin; Testing; Tight Junctions; Ventricular Arrhythmia; Ventricular Dysfunction; Western Blotting; base; cellular imaging; db/db mouse; design; diabetic; diabetic patient; in vitro Model; insight; new therapeutic target; protein crosslink; 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.

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