Cardiac Myocyte Protein Partners in Heart Function

心肌细胞蛋白在心脏功能中的伙伴

• 批准号: 10667626
• 负责人: Joshua I Goldhaber
• 金额: $ 71.83万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN DIEGO
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-07-18 至 2026-04-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10667626
• 关键词: Abbreviations; Adult; Affect; Arrhythmia; Binding; Biochemical; Black race; Cardiac; Cardiac Myocytes; Cardiac conduction system; Cardiomyopathies; Categories; Cell Communication; Cell-Cell Adhesion; Cells; Classification; Complex; Confocal Microscopy; Connexins; Coupling; Data; Defect; Dilated Cardiomyopathy; Elements; Etiology; Evaluation; Functional disorder; Future; Genetic; Genetic Predisposition to Disease; Genetic Screening; Genetic Transcription; Giant Cells; Grant; Hand; Heart; Heart Atrium; Heart Diseases; Heart failure; Hypertension; Intercalated disc; Intercellular Junctions; Ion Channel; Ischemia; Knowledge; Lateral; Link; Location; Maps; Mechanics; Membrane; Membrane Proteins; Microscopic; Modeling; Molecular; Morbidity - disease rate; Mus; Myocardium; Optics; Patients; Perinatal; Physiological; Positioning Attribute; Property; Proteins; Proteomics; Resolution; Role; Severities; Sex Differences; Sinoatrial Node; Stress; Sudden Death; Symptoms; Systemic disease; Testing; Tight Junctions; Tissues; Ventricular; Ventricular Arrhythmia; Vinculin; Work; atrioventricular node; base; cardiac muscle disease; genetic manipulation; heart function; heart preservation; heart rhythm; hemodynamics; human disease; intercellular connection; molecular phenotype; mortality; mouse model; non-genetic; novel strategies; novel therapeutics; patch clamp; postnatal; screening; sex; sudden cardiac death; transcriptomics; voltage

Cardiomyopathy (CMY) is a worldwide problem associated with high morbidity and mortality. CMY patients may present with symptoms attributed to heart failure (HF), arrhythmias, cardiac conduction system abnormalities, and sudden cardiac death. Recently it has been increasingly recognized that genetic screening for etiologies of CMY is important, and that defects in cardiomyocyte (CM) proteins in cellular junctions can cause CMY. Mechanical and electrical coupling of CM occurs at the intercellular connection between CM, termed the intercalated disk (ID). The ID provides essential properties to allow the heart to function as a syncytium. Structural elements of the cardiac conduction system (CCS) such as the atrioventricular (AV) and sinoatrial (SA) nodes have cellular arrangements and intercellular connections that vary from working CMs in the atrium and ventricle. Understanding more about proteins essential for normal function of working CMs and CCS cells is critical to advance our knowledge of the basis of cardiac disease, and remains understudied. This proposal is focused on Vinculin (VCL) and Zonula Occludens (ZO) proteins, which bind directly to one another, are located in the ID and the lateral membrane of working CMs and have known links to human disease. Our global hypothesis here is that VCL, ZO-1 and ZO-2 have unique roles in preserving cardiac function, conduction, and rhythm, given their location in CMs and in the CCS. We propose two aims. AIM 1 will evaluate how loss of ZO and VCL proteins from CMs alters contractile function and the molecular phenotype of the working CM and adult heart. We hypothesize that with postnatal loss of CM ZO and VCL proteins, cell-cell communication and integrity of the working myocardium will be disturbed, resulting in contractile dysfunction. CM ZO loss is expected to be distinct from that caused by loss of CM VCL, despite these proteins directly binding one another. Unique mouse models in hand will be used to evaluate the effects of loss of ZO and VCL from mature CMs basally and after the heart is faced with stress. We will assess whole heart, tissue and single cells using physiological, biochemical, and microscopic evaluations, as well as a novel approach to single cell transcriptomics and single cell proteomics, to pursue the mechanistic basis for how ZO and VCL protein loss causes CMY. Differences by sex and in atria vs. ventricle will be considered. AIM 2 will determine the function of ZO-1 and VCL in cardiac conduction and rhythm. Deletion of VCL from CM caused ventricular arrhythmias and sudden death, while loss of CM ZO-1 produced CCS dysfunction. We hypothesize that these two proteins have unique roles in controlling cardiac rhythm and conduction, despite their direct binding, due to interactions with connexins and membrane ion channels. Using patch clamping, high-resolution confocal microscopy to detect Ca2+ transients, optical voltage/Ca2+ mapping, and single cell transcriptional and proteomic studies, we will test how loss of ZO-1 leads to altered SAN and AVN function and excitation-contraction coupling, and how loss of VCL leads to ventricular arrhythmias and sudden death.

心肌病（CMY）是一个与高发病率和死亡率相关的世界性问题。 CMY 患者可能 出现心力衰竭（HF）、心律失常、心脏传导系统异常的症状， 和心源性猝死。近年来，人们越来越认识到，对疾病病因进行基因筛查 CMY 很重要，细胞连接处心肌细胞 (CM) 蛋白的缺陷会导致 CMY。 CM 的机械和电耦合发生在 CM 之间的细胞间连接处，称为 闰盘（ID）。 ID 提供了使心脏发挥合胞体功能的基本特性。结构性 心脏传导系统 (CCS) 的元件，例如房室 (AV) 和窦房 (SA) 结 其细胞排列和细胞间连接与心房和心室中工作的 CM 不同。 了解更多关于工作 CM 和 CCS 细胞正常功能所必需的蛋白质对于 提高了我们对心脏病基础的了解，并且仍在研究中。 该提案的重点是粘蛋白 (VCL) 和闭锁带 (ZO) 蛋白，它们直接结合 彼此之间，位于工作 CM 的 ID 和侧膜中，并且已知与 人类疾病。我们的总体假设是 VCL、ZO-1 和 ZO-2 在保护心脏方面具有独特的作用 功能、传导和节律，考虑到它们在 CM 和 CCS 中的位置。我们提出两个目标。 AIM 1 将评估 CM 中 ZO 和 VCL 蛋白的丢失如何改变收缩功能以及 工作 CM 和成人心脏的分子表型。我们假设出生后 CM ZO 丢失 和 VCL 蛋白，细胞间通讯和工作心肌的完整性将受到干扰，导致 收缩功能障碍。 CM ZO 损失预计与 CM VCL 损失造成的损失不同，尽管有这些 蛋白质之间直接结合。现有的独特小鼠模型将用于评估损失的影响 基础上和心脏面临压力后，来自成熟 CM 的 ZO 和 VCL 。我们将全心全意地评估， 使用生理、生化和显微镜评估对组织和单细胞进行评估，以及一种新颖的方法 单细胞转录组学和单细胞蛋白质组学方法，探索 ZO 的机制基础 VCL蛋白丢失导致CMY。将考虑性别以及心房与心室的差异。 AIM 2 将确定 ZO-1 和 VCL 在心脏传导和节律中的功能。删除VCL CM 引起室性心律失常和猝死，而 CM ZO-1 的缺失则导致 CCS 功能障碍。 我们假设这两种蛋白质在控制心律和传导方面具有独特的作用， 尽管它们是直接结合的，但由于与连接蛋白和膜离子通道的相互作用。使用补丁 钳位、高分辨率共焦显微镜检测 Ca2+ 瞬态、光学电压/Ca2+ 映射和单 细胞转录和蛋白质组学研究，我们将测试 ZO-1 的缺失如何导致 SAN 和 AVN 功能改变 兴奋-收缩耦合，以及 VCL 缺失如何导致室性心律失常和猝死。