Talin1 Function in Cardiac Myofibroblasts

Talin1 在心肌成纤维细胞中的功能

• 批准号: 10310438
• 负责人: Natalie A Noll
• 金额: $ 1.06万
• 依托单位: VANDERBILT UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-12-01 至 2022-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10310438
• 关键词: Ablation; Actins; Adrenergic Agents; Adrenergic beta-Antagonists; Adult; Affect; Angiotensin II; Angiotensin-Converting Enzyme Inhibitors; Atomic Force Microscopy; Binding; Binding Sites; Biochemical; Biomechanics; Cardiac; Cardiac Myocytes; Cells; Chemicals; Chronic; Coculture Techniques; Collagen; Complex; Congestive Heart Failure; Cues; Cytoskeleton; Data; Deposition; Diagnosis; Disease; Diuretics; Echocardiography; Elasticity; Experimental Models; Extracellular Matrix; Extracellular Matrix Proteins; Fiber; Fibroblast Growth Factor; Fibroblasts; Fibronectins; Fibrosis; Focal Adhesions; Functional disorder; Genetic; Genetic Transcription; Goals; Heart; Heart Hypertrophy; Heart Transplantation; Heart failure; Hypertrophy; In Vitro; Injury; Integrins; Isoproterenol; Knock-out; Knockout Mice; Lead; Left; Left Ventricular Hypertrophy; Left ventricular structure; Longevity; Measures; Mechanics; Mediating; Mediator of activation protein; Modeling; Molecular Conformation; Morphology; Mus; Myocardium; Myofibroblast; Pathologic; Patients; Periodicity; Phenotype; Physiologic intraventricular pressure; Physiological; Population; Prevalence; Process; Production; Progressive Disease; Proteins; Role; Signal Transduction; Sirius Red F3B; Smooth Muscle Actin Staining Method; Stains; Stress; Talin; Testing; Therapeutic; Thick; Tissues; Traction Force Microscopy; Transforming Growth Factors; United States; Ventricular; Ventricular Remodeling; Vinculin; Wheat Germ Agglutinins; alpha Actinin; blood pressure regulation; clinical decision-making; constriction; coronary fibrosis; effective therapy; experience; experimental study; heart function; heart preservation; hemodynamics; improved; in vitro Model; in vivo; interstitial; left ventricular assist device; mechanical stimulus; mechanotransduction; migration; new therapeutic target; novel; paxillin; pressure; response; therapeutic target; transmission process; treatment strategy

Project Summary Heart failure (HF) affects an expanding proportion of the population, and currently affects over 5 million adults in the United States alone. Due to chronic pressure overload of the left ventricle, tissue mechanics are permanently changed as interstitial fibrosis and hypertrophy of the myocardium occurs. Despite the prevalence of HF, there are no therapeutic strategies to reverse – or even reduce – cardiac fibrosis, aside from left ventricular assist devices and heart transplant, due to the poorly understood mechanobiological response of resident cardiac cells. During pressure overload induced HF, resident cardiac fibroblasts transition to activated myofibroblasts (MyoFBs), switching to the more contractile and hyper-secretory phenotype. MyoFBs express Talin1 (Tln1), a focal adhesion protein which activates integrins and undergoes force-induced mechanical unfolding, allowing for MyoFB attachment and transmission of force to and from the extracellular matrix (ECM). Preliminary data demonstrate that MyoFB Tln1 could be responsible for the adverse remodeling that occurs in HF, and deletion of this protein in MyoFBs during HF may improve cardiac function and decrease fibrosis. Thus, the central hypothesis of the current proposal is that MyoFB-specific deletion of Tln1 will reduce interstitial fibrosis, decrease left ventricular hypertrophy, and preserve cardiac function in the context of HF. We will first determine the ability of selective deletion of Tln1 from MyoFBs to reduce adverse remodeling of the surrounding myocardium in response to pressure overload (Aim1). Upon establishing Tln1 as a regulator of MyoFB mechanobiology and fibrosis, we will investigate the hypothesis that Tln1-mediated ECM deposition by MyoFBs contributes to altered cardiomyocyte (CM) hypertrophy during HF (Aim2). To study these aims, a novel MyoFB-specific Tln1 knockout mouse has been generated. Transverse aortic constriction (TAC) - an experimental model of pressure overload induced HF - will be performed, and echocardiography will be used to measure hemodynamic function of the mouse heart throughout the studies. Interstitial fibrosis and stiffness of the left ventricle will be characterized by picrosirius red staining and atomic force microscopy, respectively. CM hypertrophy will be characterized using wheat germ agglutinin staining. In vitro models will be employed to isolate the effects of ECM stiffness and ECM fibril thickness. CM and Tln1-/- MyoFB responses to these different mechanical stimuli will be investigated using traction force microscopy and micropipette aspiration. In summary, the results from this proposal will establish MyoFB Tln1 as a regulator of MyoFB-mediated cardiac fibrosis and CM hypertrophy and will highlight a novel therapeutic target for the treatment and management of HF.

项目概要 心力衰竭（HF）影响着越来越多的人口，目前影响着超过 500 万成年人。 仅美国。由于左心室慢性压力超负荷，组织力学永久受损 随着间质纤维化和心肌肥大的发生而改变。尽管心力衰竭十分普遍， 除了左心室辅助之外，没有任何治疗策略可以逆转甚至减少心脏纤维化 由于对常驻心肌细胞的机械生物学反应知之甚少，因此，设备和心脏移植的研究进展缓慢。 在压力超负荷引起心力衰竭期间，常驻心脏成纤维细胞转变为活化的肌成纤维细胞 （MyoFBs），切换到更具收缩性和高分泌表型。 MyoFBs 表达 Talin1 (Tln1)， 粘着斑蛋白激活整合素并经历力诱导的机械展开，从而允许 MyoFB 与细胞外基质 (ECM) 的附着和力传输。初步数据 证明 MyoFB Tln1 可能导致 HF 中发生的不良重塑，并且缺失 心衰期间 MyoFB 中的这种蛋白质可能会改善心脏功能并减少纤维化。因此，中央 目前提议的假设是，MyoFB 特异性删除 Tln1 将减少间质纤维化，减少 左心室肥厚，并在心力衰竭的情况下保持心脏功能。我们首先要确定能力 从 MyoFB 中选择性删除 Tln1 以减少周围心肌的不良重塑 对压力过载的响应（目标1）。在确定 Tln1 作为 MyoFB 机械生物学的调节因子后 纤维化，我们将研究这样的假设：MyoFBs 介导的 Tln1 介导的 ECM 沉积有助于改变 心衰期间心肌细胞 (CM) 肥大 (Aim2)。为了研究这些目标，一种新型的 MyoFB 特异性 Tln1 敲除方法 鼠标已经生成。横主动脉缩窄 (TAC) - 压力超载的实验模型 诱发心力衰竭 - 将进行，超声心动图将用于测量心脏的血流动力学功能 小鼠心脏贯穿整个研究。左心室间质纤维化和僵硬的特点是 分别是天狼星红染色和原子力显微镜。 CM 肥大的特征是 小麦胚芽凝集素染色。将采用体外模型来分离 ECM 硬度和 ECM 的影响 原纤维厚度。将使用以下方法研究 CM 和 Tln1-/- MyoFB 对这些不同机械刺激的反应 牵引力显微镜和微量移液器抽吸。总之，该提案的结果将确定 MyoFB Tln1 作为 MyoFB 介导的心脏纤维化和 CM 肥大的调节剂，将突出显示一种新的 心力衰竭治疗和管理的治疗目标。