Functional consequences of FHC mutations in cardiac MyBPC

心脏 MyBPC 中 FHC 突变的功能后果

基本信息

批准号：
9973440
负责人：
Julian Stelzer
金额：
$ 59.84万
依托单位：
CASE WESTERN RESERVE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2013
资助国家：
美国
起止时间：
2013-02-01 至 2024-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9973440
关键词：
Accounting Actins Actomyosin Acute Address Adolescent and Young Adult Affect Agonist Amino Acid Substitution Animals Anisotropy Behavior Binding C10 Cardiac Cardiac Muscle Contraction Cardiac Myocytes Cardiac Myosins Cardiomyopathies Computer Models Data Defect Development Disease Disease Progression Exercise Familial Hypertrophic Cardiomyopathy Fiber Filament Fluorescence Resonance Energy Transfer Foundations Gene Transfer Generations Goals Heart Heart Diseases Human Hypertrophic Cardiomyopathy Impairment Individual Infusion procedures Inherited Kinetics Knowledge Length Ligand Binding Link Maps Measurement Mechanics Mediating Microfilaments Missense Mutation Molecular Morphology Movement Mus Muscle function Mutation Myocardium Myosin ATPase N-terminal Nonmuscle Myosin Type IIA Nucleic Acid Regulatory Sequences Patients Physiology Play Property Protein Fragment Proteins Regulation Role Rotation Sarcomeres Severity of illness Skin Structure Sudden Death Testing Therapeutic Therapeutic Intervention Thick Filament Time Ventricular Workload atomic interactions base citrate carrier design disease-causing mutation efficacy testing functional disability heart function hemodynamics improved in vivo induced pluripotent stem cell insight interdisciplinary approach mutant myosin-binding protein C novel novel strategies novel therapeutics phosphorescence sensor simulation sudden cardiac death treatment strategy young adult

Accounting Actins Actomyosin Acute Address Adolescent and Young Adult Affect Agonist Amino Acid Substitution Animals Anisotropy Behavior Binding C10 Cardiac Cardiac Muscle Contraction Cardiac Myocytes Cardiac Myosins Cardiomyopathies Computer Models Data Defect Development Disease Disease Progression Exercise Familial Hypertrophic Cardiomyopathy Fiber Filament Fluorescence Resonance Energy Transfer Foundations Gene Transfer Generations Goals Heart Heart Diseases Human Hypertrophic Cardiomyopathy Impairment Individual Infusion procedures Inherited Kinetics Knowledge Length Ligand Binding Link Maps Measurement Mechanics Mediating Microfilaments Missense Mutation Molecular Morphology Movement Mus Muscle function Mutation Myocardium Myosin ATPase N-terminal Nonmuscle Myosin Type IIA Nucleic Acid Regulatory Sequences Patients Physiology Play Property Protein Fragment Proteins Regulation Role Rotation Sarcomeres Severity of illness Skin Structure Sudden Death Testing Therapeutic Therapeutic Intervention Thick Filament Time Ventricular Workload atomic interactions base citrate carrier design disease-causing mutation efficacy testing functional disability heart function hemodynamics improved in vivo induced pluripotent stem cell insight interdisciplinary approach mutant myosin-binding protein C novel novel strategies novel therapeutics phosphorescence sensor simulation sudden cardiac death treatment strategy young adult

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项目摘要

The long-range goal of this proposal is to define the mechanisms by which mutations in cardiac myosin binding protein C (MyBPC) cause hypertrophic cardiomyopathy (HCM), a disease that affects up to 1 in 200 individuals, and is the leading cause of sudden death in young adults. Nearly 60% of HCM cases are due to familial inheritance (FHC) of an autosomal dominant disorder caused by mutations in sarcomeric proteins. Mutations in MyBPC are among the most common causes of FHC accounting for half of all known cases. Because MyBPC is a critical modulator of actomyosin interactions, the initial functional deficit caused by mutations in MyBPC is expected to manifest as a defect in the regulation of cardiac muscle contraction at the myofilament level. Whereas 60% of MyBPC truncation mutations are expected to cause haploinsufficiency, the remaining 40% of MyBPC mutations are missense mutations, which are expected to produce full-length MyBPC. A large number of these missense mutations are located in the central domains of MyBPC (i.e., C3-C7), which have no specific known function, and thus it is unclear how FHC mutations located in this region of MyBPC cause disease. Our limited understanding of these critical mechanisms severely limits options for therapeutic intervention for FHC patients. Our preliminary data provide novel evidence that addresses our gap in knowledge and have identified two important regulatory regions within the C4 and C5 domains of MyBPC that modulate cardiac muscle contractile function. Based on these novel observations we have devised an experimental plan that is designed to elucidate molecular mechanisms by which these key regions contribute to regulation of contractile function and how FHC mutations alter this regulation. We have devised a multidisciplinary approach that spans from computational modeling of atomic interactions to whole animal physiology which will accomplished in three principal aims designed to: 1) Establish the functional effects of central domain MyBPC FHC mutations on the magnitude and rate of force in cardiac fibers isolated from mouse hearts expressing HCM causing mutations, and utilize molecular dynamic simulations to elucidate the molecular mechanisms of altered function. 2) Define how MyBPC mutations alter actin and myosin binding properties and rotational dynamics using TPA and FRET based sensors, and 3) Determine the in vivo functional consequences of MyBPC FHC mutations in MyBPC by assessing ventricular contractile and hemodynamic function, and test the efficacy of a MyBPC-specific AAV9 gene-transfer rescue that normalizes contractile function. Parallel studies will utilize FHC patient-specific induced pluripotent stem cell cardiomyocytes (iPSC-CM) to determine how these mutations cause disease in humans. It is expected that results from these integrative studies will provide novel insights of the underlying mechanisms by which mutations in MyBPC cause disease and will aid in the development of novel therapeutic strategies for treatment MyBPC related HCM.

该提案的远程目标是定义心脏肌球蛋白结合中突变的机制蛋白C（MYBPC）引起肥厚性心肌病（HCM），这种疾病影响高达200人，这是年轻人突然死亡的主要原因。近60％的HCM病例是由于家族性的由肉瘤蛋白突变引起的常染色体显性疾病的遗传（FHC）。突变 MYBPC是FHC最常见的原因之一，其中一半已知病例。因为mybpc 是肌动蛋白相互作用的关键调节剂，由MyBPC突变引起的最初功能不足是预计将表现为在肌丝水平上心脏肌肉收缩调节的缺陷。而60％的MYBPC截断突变预计会引起单倍弥补，其余40％ MYBPC突变是错义突变，预计会产生全长MYBPC。大量这些错义突变中的位于MYBPC的中心域（即C3-C7），它们没有特定已知功能，因此尚不清楚FHC突变如何位于MYBPC该区域引起疾病。我们的对这些关键机制的有限理解严重限制了FHC治疗干预的选择患者。我们的初步数据提供了解决我们知识差距的新颖证据，并已经确定了 MYBPC的C4和C5域内的两个重要调节区域调节心脏肌肉收缩功能。基于这些新颖的观察，我们设计了一个设计的实验计划阐明这些关键区域有助于调节收缩功能的分子机制以及FHC突变如何改变该调节。我们设计了一种跨越的多学科方法原子相互作用与整个动物生理学的计算建模将在三个中完成主要目的旨在：1）建立中央域MYBPC FHC突变对该功能的功能效应从表达HCM的小鼠心脏分离的心脏纤维的大小和力速率，导致突变，并利用分子动力学模拟来阐明功能改变的分子机制。 2）定义 MyBPC突变如何使用TPA和FRET改变肌动蛋白和肌球蛋白结合特性和旋转动力学基于基于的传感器，3）确定MYBPC中MyBPC FHC突变的体内功能后果评估心室收缩和血液动力学功能，并测试MYBPC特异性AAV9的功效基因转移救援将收缩功能归一化。平行研究将利用FHC患者特异性诱导多能干细胞心肌细胞（IPSC-CM）确定这些突变如何引起人类疾病。它预计这些综合研究的结果将提供基本机制的新见解 MYBPC中的突变会引起疾病，并有助于开发新的治疗策略治疗MYBPC相关的HCM。