Beta-arrestin Signaling and Sarcomere Calcium-Response in Familial Dilated Cardiomyopathy

家族性扩张型心肌病中的β-抑制蛋白信号传导和肌节钙反应

基本信息

批准号：
9330917
负责人：
David M Ryba
金额：
$ 2.57万
依托单位：
UNIVERSITY OF ILLINOIS AT CHICAGO
依托单位国家：
美国
项目类别：
财政年份：
2015
资助国家：
美国
起止时间：
2015-09-30 至 2018-05-15
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9330917
关键词：
Affect Aftercare Angiotensin II Angiotensin Receptor Animals Area Biochemical Calcium Cardiac Characteristics Chronic Clinical Data Complex Coupled Detergents Development Dilated Cardiomyopathy Disease Progression Echocardiography Fiber Functional disorder G-substrate GTP-Binding Proteins Goals Grant Heart Heart Transplantation Heart failure Histologic Human Hypertension Hypertrophy In Vitro Investigation Kinetics Left Ventricular Function Ligands Link Losartan Measurement Measures Mediating Methods Microfilaments Microscopic Microscopy Missense Mutation Molecular Morphology Mus Patients Pharmacology Phenotype Phosphoric Monoester Hydrolases Phosphorylation Phosphotransferases Post-Translational Protein Processing Preventive Intervention Proteins Proteome Proteomics Receptor, Angiotensin, Type 1 Reporting Rest Saline Sarcomeres Signal Pathway Signal Transduction Signal Transduction Pathway Signaling Molecule Skin Text Therapeutic Intervention Transgenic Mice Transgenic Model Tropomyosin Work beta-arrestin blood pump experimental study familial dilated cardiomyopathy heart cell heart function hemodynamics improved improved functioning in vivo infancy insight mouse model mutant novel pre-clinical prevent public health relevance response scaffold success targeted treatment

项目摘要

DESCRIPTION (provided by applicant): Familial dilated cardiomyopathy (DCM) is a condition that leads to heart failure and is the most common cause of heart transplantation. The molecular mechanisms of disease progression are not well characterized, and there are no current therapies available for this condition. A characteristic molecular change in DCM is decreased myofilament response to Ca2+. Thus, we hypothesized that by increasing the myofilament response to Ca2+ we may be able to prevent the development of DCM. As proof of principle, we crossed a transgenic model with a missense mutation on sarcomeric protein, tropomyosin (TG-Tm-E54K), which displays a phenotype similar to human DCM, with a transgenic mouse characterized by a constitutive increase in Ca2+-sensitivity. In these double transgenic mice, DCM does not develop. Results from our preliminary studies indicate that novel beta-arrestin signaling pathways are directly involved in signaling to myofilaments, imparting Ca2+-sensitizing post-translational modification, and improving heart function. In this proposal, we hypothesize that beta-arrestin signaling prevents the progression of and reverses DCM by improving the Ca2+ responsiveness of the myofilament. Our approach is to employ TG-TmE54K mice and treat them with the biased ligand, TRV120023, which acts as an angiotensin receptor blocker but is able to activate beta-arrestin signaling, or Losartan, an angiotensin receptor blocker. In Specific Aim 1 we will evaluate the progression of the disease before, during and after treatment in vivo utilizing serial echocardiography. We will also assess left ventricular function in vivo and morphology using hemodynamic studies and histological methods, respectively. To approach Specific Aim 2, we will employ detergent extracted fiber bundles to measure steady-state force and kinetics of treated animals and saline controls. We will also determine the mechanism behind these changes using biochemical methods where we will elucidate the signal transduction pathways activated. In Specific Aim 3 we will use biochemical methods and microscopy to examine beta-arrestin localization to fully characterize these novel signal transduction pathways. We expect that activation of beta-arrestin signaling, while blocking G- protein mediated signaling, will prevent the progression of and reverse DCM by increasing Ca2+-responsiveness of the myofilament. Therefore, results from this proposal will yield pre-clinical data for a potential treatment for DCM, as well as insight into the molecular mechanisms of heart failure.

描述（由适用提供）：家族性扩张心肌病（DCM）是导致心力衰竭的疾病，是心脏移植的最常见原因。疾病进展的分子机制没有很好地表征，并且目前尚无治疗方法。 DCM中的特征分子变化减少了对Ca2+的肌丝反应。我们也许能够防止DCM的发展。作为原理的证明，我们越过了一个转基因模型，具有肉瘤蛋白上的错义突变，tropomyosin（TG-TM-E54K）显示出类似于人类DCM的表型，其转基因小鼠的特征是Ca2+ - 敏感性的组成型增加。在这些双重转基因小鼠中，DCM不会发展。我们的初步研究的结果表明，新型的β-arrestin信号通路直接参与了向肌丝的信号传导，赋予Ca2+敏感性的翻译后修饰和改善心脏功能。在此提案中，我们假设β-arrestin信号传导通过提高肌丝的Ca2+响应性来阻止DCM的发展和逆转。我们的方法是采用TG-TME54K小鼠，并使用有偏的配体TRV120023对其进行处理，该配体充当血管紧张素接收器阻滞剂，但能够激活β-arrestin信号传导或losartan，losartan，losartan，losartan，losartan是一种血管紧张素受体阻滞剂。具体 AIM 1我们将使用系列超声心动图在体内，期间和之后评估该疾病的进展。我们还将分别使用血液动力学研究和组织学方法评估体内和形态的左心室功能。为了接近特定的目标2，我们将采用确定的提取的纤维束来测量治疗动物和盐水控制的稳态力和动力学。我们还将使用生化方法来确定这些变化背后的机制，我们将阐明被激活的信号传递途径。在特定目标3中，我们将使用生化方法和显微镜检查β-arrestin定位，以充分表征这些新型的信号传递途径。我们期望β-arrestin信号的激活在阻断G蛋白介导的信号传导的同时，将通过增加肌丝的Ca2+反应性来防止DCM的发展和反向DCM。因此，该提案的结果将产生临床前数据，以便对DCM进行潜在治疗，并深入了解心力衰竭的分子机制。