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：
10602552
负责人：
Julian Stelzer
金额：
$ 57.68万
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 2025-03-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10602552
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 Incubated 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 Persons Physiology Play Property Protein Fragment Proteins Regulation Role Sarcomeres Severity of illness Skin Structure Sudden Death Testing Therapeutic Therapeutic Intervention Thick Filament Time Ventricular Workload atomic interactions autosome citrate carrier design disease-causing mutation efficacy testing functional disability heart function hemodynamics improved in vivo induced pluripotent stem cell induced pluripotent stem cell derived cardiomyocytes insight interdisciplinary approach mimetics molecular dynamics mutant myosin-binding protein C novel novel strategies novel therapeutic intervention novel therapeutics phosphorescence sensor sudden cardiac death treatment strategy young adult

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.

该提案的长期目标是确定心肌肌球蛋白结合突变的机制蛋白 C (MyBPC) 会导致肥厚型心肌病 (HCM)，这种疾病影响多达二百分之一的人，并且是年轻人猝死的主要原因。近 60% 的 HCM 病例是由于家族遗传由肌节蛋白突变引起的常染色体显性遗传（FHC）。突变在 MyBPC 是 FHC 最常见的原因之一，占所有已知病例的一半。因为MyBPC 是肌动球蛋白相互作用的关键调节剂，MyBPC 突变引起的初始功能缺陷是预计表现为肌丝水平心肌收缩调节的缺陷。虽然 60% 的 MyBPC 截短突变预计会导致单倍体不足，但其余 40% MyBPC 突变是错义突变，预计会产生全长 MyBPC。数量很大这些错义突变位于 MyBPC 的中央结构域（即 C3-C7），其没有特异性功能已知，因此尚不清楚位于 MyBPC 该区域的 FHC 突变如何导致疾病。我们的对这些关键机制的了解有限，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新的证据，解决了我们的知识差距，并确定了 MyBPC 的 C4 和 C5 结构域内两个重要的调节心肌的调节区域收缩功能。基于这些新颖的观察结果，我们设计了一个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 突变如何改变这种调节。我们设计了一种多学科方法，涵盖原子相互作用与整个动物生理学的计算模型将在三个时间内完成主要目标旨在： 1) 确定中央域 MyBPC FHC 突变对从表达 HCM 的小鼠心脏中分离出的心肌纤维的力的大小和速率导致突变，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的结合特性和旋转动力学 3) 通过以下方式确定 MyBPC FHC 突变在 MyBPC 中的体内功能后果：评估心室收缩和血流动力学功能，并测试 MyBPC 特异性 AAV9 的功效使收缩功能正常化的基因转移救援。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) 以确定这些突变如何导致人类疾病。它预计这些综合研究的结果将为潜在机制提供新的见解 MyBPC 中的突变会导致疾病，并将有助于开发新的治疗策略治疗MyBPC相关的HCM。

项目成果

期刊论文数量（17）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Human cardiac myosin-binding protein C restricts actin structural dynamics in a cooperative and phosphorylation-sensitive manner.

人心肌肌球蛋白结合蛋白 C 以协作且磷酸化敏感的方式限制肌动蛋白结构动力学。

DOI：
发表时间：
2019-11-01
期刊：
影响因子：
0
作者：
Bunch, Thomas A;Kanassatega, Rhye;Lepak, Victoria C;Colson, Brett A
通讯作者：
Colson, Brett A

A high-throughput fluorescence lifetime-based assay to detect binding of myosin-binding protein C to F-actin.

一种基于高通量荧光寿命的测定法，用于检测肌球蛋白结合蛋白 C 与 F-肌动蛋白的结合。

DOI：
发表时间：
2021-03-01
期刊：
影响因子：
0
作者：
Bunch, Thomas A;Lepak, Victoria C;Bortz, Kellan M;Colson, Brett A
通讯作者：
Colson, Brett A

Basic science methods for the characterization of variants of uncertain significance in hypertrophic cardiomyopathy.

用于表征肥厚型心肌病中意义不确定的变异的基础科学方法。

DOI：
发表时间：
2023
期刊：
影响因子：
0
作者：
Doh, Chang Yoon;Kampourakis, Thomas;Campbell, Kenneth S;Stelzer, Julian E
通讯作者：
Stelzer, Julian E

cMyBPC phosphorylation modulates the effect of omecamtiv mecarbil on myocardial force generation.

cMyBPC 磷酸化调节 omecamtiv mecarbil 对心肌力产生的影响。

DOI：
发表时间：
2021
期刊：
影响因子：
0
作者：
Mamidi, Ranganath;Holmes, Joshua B;Doh, Chang Yoon;Dominic, Katherine L;Madugula, Nikhil;Stelzer, Julian E
通讯作者：
Stelzer, Julian E

Cardiac myosin-binding protein C N-terminal interactions with myosin and actin filaments: Opposite effects of phosphorylation and M-domain mutations.

心肌肌球蛋白结合蛋白 C N 末端与肌球蛋白和肌动蛋白丝的相互作用：磷酸化和 M 结构域突变的相反作用。