The Role of Vinculin in Cardiomyocyte Adhesion and Mechanical Continuity

纽蛋白在心肌细胞粘附和机械连续性中的作用

• 批准号: 9256873
• 负责人: Chelsea Merkel
• 金额: $ 4.37万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-06-01 至 2020-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9256873
• 关键词: Actin-Binding Protein; Actins; Adherens Junction; Adhesions; Adhesives; Affect; Age; Aging; Architecture; Binding; Biology; Cadherins; Cardiac; Cardiac Myocytes; Cell Adhesion; Cells; Complex; Confocal Microscopy; Contracts; Coupled; Coupling; Cytoskeleton; Data; Electric Conductivity; Electron Microscopy; Environment; Epithelial Cells; Extracellular Matrix; Fiber; Focal Adhesions; Giant Cells; Heart; Human; Individual; Intercalated disc; Intercellular Junctions; Knowledge; Light; Link; Mechanics; Mediating; Microfilaments; Microscopy; Molecular; Mus; Myocardial Contraction; Myocardium; Myofibrils; Myosin ATPase; Neonatal; Platinum; Positioning Attribute; Proteins; Recruitment Activity; Regulation; Research; Resolution; Role; Shapes; Site; Structure; Time; Tissues; Vinculin; Work; alpha catenin; base; extracellular; heart function; insight; link protein; protein complex; theories

Project Summary/Abstract Heart muscle cells (cardiomyocytes) beat over 100,000 times per day. Successful heart contraction requires that cardiomyocytes be physically coupled. This is accomplished through the intercalated disc (ICD): a specialized adhesive structure joining cardiomyocytes end-to-end to form a functional syncytium. The ICD contains protein complexes responsible for mechanical strength and protein complexes responsible for electrical conductance. The adherens junction (AJ) is a protein complex responsible for mechanical strength and integrates the actin cytoskeletons of neighboring cells. Myofibrils, organized actin-myosin structures, are the contractile machinery of the heart and produce the force necessary for individual cardiomyocytes to beat. Myofibrils terminate in the ICD, and linking myofibrils between cardiomyocytes allows for mechanical continuity across cells. However, how these myofibrils are coupled between cells is largely unknown. Vinculin is a key protein mediating cell-cell and cell-extracellular matrix (ECM) contacts, serving to link both complexes to the actin cytoskeleton. Vinculin is recruited to AJs in a tension-dependent mechanism and is enriched at the AJ-myofibril interface in cardiomyocytes. Expression of vinculin at cell-cell contacts increases in aging heart muscle and is thought to be cardio-protective, and disorganization of vinculin is seen in failing heart muscle. Yet the role of vinculin at the ICD is poorly understood. In this proposal, it is hypothesized that vinculin anchors myofibrils to AJs and mediates crosstalk between cell-cell and cell-ECM contacts. In Aim 1, the linkage between myofibrils and AJs will be investigated by defining the myofibril-vinculin-AJ interface and determining the role of vinculin and its AJ binding partner, αE-catenin in promoting AJ stability. In Aim 2, the crosstalk between AJs and cell-ECM contacts will be investigated by altering the ECM environment and determine its influence on vinculin localization, dynamics, and tension at cell-ECM contacts and AJs. The work proposed will further the understanding of a fundamental aspect of cardiac biology: how individual cardiomyocytes are coupled to create a functional syncytium. This research will elucidate vinculin function in the heart, shedding light on to its cardio-protective role.

项目概要/摘要 心肌细胞（心肌细胞）每天跳动超过 100,000 次，成功的心脏收缩需要。 心肌细胞通过闰盘 (ICD) 进行物理耦合： 特殊的粘合结构将心肌细胞端对端连接起来形成功能性合胞体。 蛋白质包含负责机械强度的复合物和负责机械强度的蛋白质复合物 粘附连接 (AJ) 是一种负责机械强度的蛋白质复合物。 并整合邻近细胞的肌动蛋白细胞骨架，肌原纤维是有组织的肌动蛋白-肌球蛋白结构。 心脏的收缩机制并产生单个心肌细胞跳动所需的力量。 肌原纤维终止于 ICD，连接心肌细胞之间的肌原纤维可实现机械连续性 然而，这些肌原纤维如何在细胞之间耦合尚不清楚。 纽蛋白是介导细胞与细胞和细胞与细胞外基质 (ECM) 接触的关键蛋白质，用于连接两者 纽蛋白与肌动蛋白细胞骨架的复合物以张力依赖性机制被募集到 AJ 上。 心肌细胞中 AJ-肌原纤维界面处的纽蛋白表达在细胞与细胞接触处增加。 老化的心肌，被认为具有心脏保护作用，而纽蛋白的混乱则出现在心脏衰竭的情况下 然而，对于纽蛋白在 ICD 中的作用知之甚少。在该提案中，人们对纽蛋白进行了研究。 将肌原纤维锚定在 AJ 上并介导细胞与细胞和细胞与 ECM 接触之间的串扰。 将通过定义肌原纤维-纽蛋白-AJ 界面来研究肌原纤维和 AJ 之间的联系 确定纽蛋白及其 AJ 结合伴侣 αE-连环蛋白在促进 AJ 稳定性中的作用。 AJ 和细胞-ECM 接触之间的串扰将通过改变 ECM 环境来研究 确定其对纽蛋白定位、动力学以及细胞 ECM 接触和 AJ 张力的影响。 拟议的工作将进一步了解心脏生物学的一个基本方面：个体如何 心肌细胞耦合形成功能性合胞体，该研究将阐明纽蛋白的功能。 心脏，揭示其心脏保护作用。