Gap Junctional Patterning in Arrhythmic Heart

心律失常心脏的间隙连接模式

• 批准号: 8227961
• 负责人: ROBERT G GOURDIE
• 金额: $ 32.86万
• 依托单位: MEDICAL UNIVERSITY OF SOUTH CAROLINA
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-04-01 至 2012-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8227961
• 关键词: Actin-Binding Protein; Actins; Action Potentials; Adhesions; Arrhythmia; Binding; Biochemical; Biological Assay; Biological Process; Biotinylation; CTF1 gene; Cardiac; Cardiomyopathies; Cell Culture Techniques; Cell Line; Cell membrane; Cell physiology; Cells; Chimeric Proteins; Cicatrix; Clinical; Coculture Techniques; Communication; Competence; Connexin 43; Connexins; Connexon; Coronary artery; Coupling; Data; Dyes; Echocardiography; Electrocardiogram; Electrophysiology (science); Fibroblasts; Frequencies; Gap Junctions; Goals; Heart; Hela Cells; Heterogeneity; Human; Imagery; Implant; In Vitro; Infarction; Injury; Left ventricular structure; Life; Ligation; Link; Manuscripts; Maps; Mediating; Membrane; Methods; Molecular; Morbidity - disease rate; Mus; Muscle Cells; Myocardial; Myocardial Infarction; Myofibroblast; Neonatal; Optics; Pattern; Peer Review; Peptides; Physiological; Predisposition; Prevention approach; Prevention therapy; Process; Proteins; Protocols documentation; Publishing; Role; Silicones; Skin; Sudden Death; Surface; Telemetry; Testing; Tight Junctions; Time; Tissues; Transgenic Mice; Translating; Ventricular Remodeling; Work; cellular imaging; in vivo; insight; intercellular communication; loss of function; mortality; mutant; novel; novel strategies; patch clamp; public health relevance; research study; response; uptake

DESCRIPTION (provided by applicant): Direct cytosolic communication between cells is mediated by an aggregate of intercellular channels in the plasma membrane called the gap junction (GJ). Remodeling of connexin43 (Cx43) GJs has been linked to cardiac arrhythmias. Work accomplished during the previous period of this RO1 identified a biological function of interaction between Cx43 and the actin-binding protein Zonula Occludens (ZO)-1 in GJ remodeling. In recent work, we have determined that a peptide known to inhibit Cx43/ZO-1 interaction, 1CT1, reduces the frequency of inducible arrhythmias following injury to the left ventricle. Preliminary data from work performed with 1CT1 in vitro, indicates that the transition from free connexon channels in the membrane to paired connexons in intercellular channel aggregates underlies GJ remodeling. We hypothesize that ZO-1 regulates the rate at which free connexons in the membrane accrete to GJs-the "connexon switch". The aims in this renewal will test this hypothesis and its implications for GJ intercellular communication, membrane excitability, and a novel role for Cx43 in differential adhesion between myocytes and fibroblasts following myocardial infarction - all processes likely to impact susceptibility to re-entrant arrhythmia. The proposed experiments will quantitatively determine the role of Cx43/ZO-1 interaction in the "connexon switch" using methods including live cell imaging, fluorescent fusion proteins, loss-of-function mutants, whole cell patch clamp, single channel electrophysiology and biochemical assays. Implications of Cx43/ZO-1 interaction within the physiological framework of cardiac injury in vivo will be assessed by echocardiography, EKG telemetry, optical mapping of electrical activation and arrhythmia induction protocols. The data generated will broaden our understanding of fundamental mechanisms of Cx43 function and may translate to new therapies for the prevention and treatment of cardiac arrhythmia. PUBLIC HEALTH RELEVANCE: Injury and scarring of the heart following myocardial infarction (heart attack) is one the most frequent causes of sudden death in the USA. This project will deliver new insights on the function of a protein essential to a stable heartbeat called connexin43. The project aims to provide novel approaches to the prevention and treatment of heart attacks.

描述（由申请人提供）：细胞间的直接胞质通讯由质膜中称为差距连接（GJ）的细胞间通道聚集体介导。连接蛋白43（Cx43）GJ的重塑与心律失常有关。本研究报告前期完成的工作确定了Cx43和肌动蛋白结合蛋白封闭带（ZO）-1在GJ重塑中相互作用的生物学功能。在最近的工作中，我们已经确定，已知抑制Cx43/ZO-1相互作用的肽，1CT 1，减少左心室损伤后诱导性心律失常的频率。来自用1CT 1在体外进行的工作的初步数据表明，从膜中的游离连接子通道到细胞间通道聚集体中的成对连接子的转变是GJ重塑的基础。我们推测ZO-1调节细胞膜中游离连接子附着于GJs的速率--“连接子开关”。本次更新的目的将测试这一假设及其对GJ细胞间通讯、膜兴奋性的影响，以及心肌梗死后Cx43在肌细胞和成纤维细胞之间差异粘附中的新作用-所有过程都可能影响对折返性心律失常的易感性。本实验将采用活细胞成像、荧光融合蛋白、功能缺失突变体、全细胞膜片钳、单通道电生理学和生物化学分析等方法定量测定Cx43/ZO-1相互作用在“连接子开关”中的作用。将通过超声心动图、EKG遥测、电激活的光学标测和心律失常诱导方案评估Cx43/ZO-1相互作用在体内心脏损伤的生理框架内的意义。产生的数据将拓宽我们对Cx43功能的基本机制的理解，并可能转化为预防和治疗心律失常的新疗法。 公共卫生相关性：心肌梗死（心脏病发作）后心脏损伤和瘢痕形成是美国猝死的最常见原因之一。该项目将提供关于稳定心跳所必需的蛋白质connexin 43功能的新见解。该项目旨在提供预防和治疗心脏病发作的新方法。