Integrins and Caveolin Proteins in Cardiac Hypertrophy and Failure

整合素和小窝蛋白在心脏肥大和衰竭中的作用

• 批准号: 8842694
• 负责人: DAVID M ROTH
• 金额: $ 64.72万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN DIEGO
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-09-01 至 2016-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8842694
• 关键词: Actins; Acute; Adhesives; Adult; Ambulatory Care; Area; Attention; Biochemical; Cardiac; Cardiac Myocytes; Cardiomyopathies; Caveolae; Caveolins; Cell membrane; Cell physiology; Cell surface; Cells; Chronic; Cytoskeletal Proteins; Cytoskeleton; Data; Disease; Endocytosis; Extracellular Matrix; Failure; Family; Focal Adhesions; Grant; Health; Heart; Heart Diseases; Heart Hypertrophy; Heart failure; Hospitalization; Inpatients; Integrin Signaling Pathway; Integrin-mediated Cell Adhesion Pathway; Integrins; Investigation; Knock-out; Knockout Mice; Lead; Link; Mechanical Stimulation; Mechanics; Mediating; Membrane; Membrane Microdomains; Mus; Mutation; Myocardial; Myocardial dysfunction; Myocardium; Organ; Patients; Phenotype; Plant Roots; Play; Prevalence; Process; Property; Protein Family; Proteins; Proteomics; Receptor Signaling; Role; Shapes; Signal Transduction; Signaling Molecule; Signaling Protein; Testing; Therapeutic; Transgenic Mice; Transgenic Organisms; base; caveolin-3; clinically significant; crosslink; flasks; gain of function; hemodynamics; improved; lipid metabolism; mouse model; novel; novel therapeutics; overexpression; prevent; protein function; response; skeletal

DESCRIPTION (provided by applicant): The mechanisms by which the cardiac myocyte (CM) senses mechanical changes and converts it to biochemical and functional effects, are poorly understood. Two areas within the CM that appear critical for proper mechanotransduction are the costamere with its resident integrins (ITGs), and caveolae, flask-shaped membrane invaginations with associated Caveolin (Cav) proteins. We and others have begun to show the importance of CM ITGs and Cav proteins in transducing mechanical signals, and that reduced expression and/ or mutation of ITGs and Cav3 can cause cardiomyopathies. How ¿1 ITGs and Cav-3 functionally interact and by what mechanisms their coordinated responses transduce mechanical signals in the CM are unknown. We have generated ¿1 ITG CM-specific knockout (KO) (termed ¿1cKO), Cav-3KO and CM-specific ITG and Cav-3 transgenic (Tg) mouse models. Our preliminary data shows that ¿1 ITG and Cav-3 co-localize and co-immunoprecipitate in the adult CM and that increased expression of ITGs and Cav-3 proteins in CMs can both preserve myocardial function when the heart is challenged with an increased mechanical load. Based on this data, we formulated our overall hypotheses that: A) ¿1 ITGs and Cav-3 have cooperative properties in organization of proteins required for CM mechanotransduction and B) that increased expression of both of these proteins in the CM will protect the heart challenged with an increased hemodynamic load from HF. We will pursue this with 3 aims using loss and gain of function approaches: 1) Determine roles of ¿1 ITGs and caveolin-3 in mechanotransductive responses of the myocardium by use of Cav3 null and ¿1 ITG cardiac myocyte specific knockout mice alone, or in combination. We will evaluate how acute and chronic mechanically mediated signals are altered when ITGs, Cav-3 or both proteins are lost from the CM and how loss of these proteins modifies the remodeling process as the heart hypertrophies and evolves towards a HF phenotype. 2) Define the interactions which direct cooperative mechanical signaling of cardiomyocyte ¿1 ITG and Cav-3. Direct interactions between ITGs and Cav3, with costameric and cytoskeletal proteins will be assessed. Proteomics will then identify novel proteins which interact with ITGs or Cav3, and how proteins in the caveolar and non-caveolar biochemical fraction of the CM change with hemodynamic challenge. 3) Determine how Tg overexpression of Cav-3 and/ or ¿¿1 ITGs alters mechanical responses, and delays or protects the heart from cardiac failure in the face of hypertrophic induction. This will allow us to directl test the potential therapeutic roles of Cav3 and ¿1 ITGs in the mechanically challenged myocardium. Clinical Significance: HF of varied causes is found in a large number of patients, necessitating frequent inpatient and outpatient care. Identification of root causes of cardiac dysfunction and importantly, studies which could lead to novel therapeutics of this common disease, are essential, and will be the focus of this proposal.

描述（由申请人提供）：人们对心肌细胞（CM）感知机械变化并将其转化为生化和功能效应的机制知之甚少。 CM 内对于正确的机械转导至关重要的两个区域是具有常驻整合素 (ITG) 的肋节，以及具有相关小凹蛋白 (Cav) 蛋白的小凹、烧瓶形膜内陷。我们和其他人已经开始证明 CM ITG 和 Cav 蛋白在转导机械信号中的重要性，并且 ITG 和 Cav3 表达减少和/或突变可导致心肌病。 ¿1 ITG 和 Cav-3 在功能上如何相互作用以及它们的协调反应通过什么机制在 CM 中转导机械信号尚不清楚。我们已经生成了 ¿1 ITG CM 特异性敲除 (KO)（称为 ¿1cKO）、Cav-3KO 和 CM 特异性 ITG 和 Cav-3 转基因 (Tg) 小鼠模型。我们的初步数据表明，1 ITG 和 Cav-3 在成人 CM 中共定位和共免疫沉淀，并且当心脏受到机械负荷增加的挑战时，CM 中 ITG 和 Cav-3 蛋白表达的增加都可以保护心肌功能。基于这些数据，我们制定了总体假设：A) ¿1 ITG 和 Cav-3 在组织 CM 机械转导所需的蛋白质方面具有协同特性，B) 增加 CM 中这两种蛋白质的表达将保护因心力衰竭而导致血流动力学负荷增加的心脏。我们将使用功能丧失和获得的方法来实现 3 个目标：1）单独或组合使用 Cav3 null 和 ¿1 ITG 心肌细胞特异性敲除小鼠，确定 ¿1 ITG 和 Caveolin-3 在心肌机械传导反应中的作用。我们将评估当 ITG、Cav-3 或两种蛋白从 CM 中丢失时，急性和慢性机械介导的信号如何改变，以及随着心脏肥大并向 HF 表型演化，这些蛋白的丢失如何改变重塑过程。 2) 定义指导心肌细胞 ¿1 ITG 和 Cav-3 协同机械信号传导的相互作用。将评估 ITG 和 Cav3 之间以及肋骨和细胞骨架蛋白之间的直接相互作用。然后，蛋白质组学将鉴定与 ITG 或 Cav3 相互作用的新蛋白质，以及 CM 的小凹和非小凹生化部分中的蛋白质如何随血流动力学挑战而变化。 3) 确定 Cav-3 和/或 ¿¿1 ITG 的 Tg 过度表达如何改变机械反应，并在面对肥厚诱导时延迟或保护心脏免受心力衰竭。这将使我们能够直接测试 Cav3 和 ¿1 ITG 在机械损伤的心肌中的潜在治疗作用。临床意义：大量患者患有各种原因的心力衰竭，需要频繁的住院和门诊治疗。确定心脏功能障碍的根本原因，重要的是，研究可能导致这种常见疾病的新疗法是至关重要的，也将成为该提案的重点。