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）：对于心肌细胞（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 内对于适当的机械转导至关重要的两个区域是肋节及其驻留区域。我们和其他人已经开始展示 CM ITG 和整合素 (ITG) 以及小凹 (Caveolae)、与相关小凹蛋白 (Cav) 蛋白的烧瓶状膜内陷的重要性。 Cav 蛋白转导机械信号，ITG 和 Cav3 表达减少和/或突变可导致心肌病。 1 ITG 和 Cav-3 在功能上相互作用，以及它们的协调反应通过什么机制在 CM 中转换机械信号尚不清楚。 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 我们的初步数据显示 ¿1cKO。 1 ITG 和 Cav-3 在成人 CM 中共定位和共免疫沉淀，并且根据该数据，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。 ，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) 增加这两种蛋白质在 CM 中的表达将保护因 HF 导致血流动力学负荷增加而受到挑战的心脏，我们将通过 3 来实现这一目标。使用功能损失和增益方法的目标：1) 确定 ¿ 1 通过使用 Cav3 null 和 ¿，ITG 和 Caveolin-3 在心肌的机械传导反应中的作用1 ITG 心肌细胞特异性敲除小鼠单独或组合我们将评估当 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，以及这些蛋白的丢失如何改变重塑过程。心脏肥大并向 HF 表型发展 2) 定义指导心肌细胞协同机械信号传导的相互作用 ¿ 1 ITG 和 Cav-3。然后将评估 ITG 和 Cav3 与肋骨和细胞骨架蛋白之间的直接相互作用，然后将鉴定与 ITG 或 Cav3 相互作用的新蛋白质，以及小凹和非小凹生化部分中的蛋白质如何。 CM 随着血流动力学挑战而变化 3) 确定 Cav-3 和/或 ¿ ¿ 1 ITG 会改变机械反应，并在肥厚诱导时延迟或保护心脏免于心力衰竭，这将使我们能够直接测试 Cav3 和 ¿ 的潜在治疗作用。 1 机械损伤心肌中的 ITG 临床意义：在大量患者中发现了各种原因的心力衰竭，需要经常进行住院和门诊护理，确定心功能障碍的根本原因，并且重要的是，研究可能会导致这种情况的新治疗方法。常见疾病是必不可少的，并且将是本提案的重点。