Modulation of heart function by Muscle LIM protein-mediated mechanotransduction

肌肉 LIM 蛋白介导的机械转导调节心脏功能

基本信息

批准号：
10645223
负责人：
Yibing Qyang
金额：
$ 41.88万
依托单位：
YALE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2022
资助国家：
美国
起止时间：
2022-07-01 至 2026-06-30
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10645223
关键词：
3 year old Actins Actomyosin Affect Affinity Autophagocytosis Biomechanics Biopsy Bioreactors Calcineurin Calcineurin inhibitor Calcium Calpain Cardiac Cardiac Myocytes Cardiac Myosins Complex Computer Models Coupled Development Diastole Disinhibition Event Extracellular Matrix Familial Hypertrophic Cardiomyopathy Fiber Fibroblasts Foundations Future Generations Genes Genetic Heart Diseases Heart Hypertrophy Heart failure Heterozygote Human Hyperactivity Hypertrophic Cardiomyopathy Hypertrophy Impairment Individual Inherited Intervention Investigation Lasers Left Left Ventricular Hypertrophy Length Lysosomes Mechanics Mediating Microfilaments Molecular Muscle Muscle Contraction Mutation Myocardial dysfunction Myocardium Myosin ATPase Myosin Heavy Chains Nonsense Codon Nuclear Obstruction PPP3CA gene Parents Pathologic Pathway interactions Patients Peptide Hydrolases Persons Phenotype Physiological Point Mutation Production Protein Isoforms Proteins Relaxation Repression Rodent Role Sarcomeres Signal Transduction Skin Somatic Cell Stem Cell Factor Stress Stretching System Systole T-Cell Activation Testing Tissues Ubiquitin Ventricular beta-Myosin cardiac tissue engineering design disease phenotype heart function human disease improved induced pluripotent stem cell induced pluripotent stem cell derived cardiomyocytes innovation insight male mechanical properties mechanical stimulus mechanotransduction mouse model multicatalytic endopeptidase complex muscle LIM protein mutant novel novel strategies novel therapeutics nuclear factors of activated T-cells pharmacologic prevent proband protein degradation recruit response scaffold sudden cardiac death transmission process

项目摘要

Familial hypertrophic cardiomyopathy (HCM) is the most common inherited cardiac disease and is typically caused by mutations in genes encoding sarcomeric proteins that regulate cardiac contractility. HCM manifestations include left ventricular hypertrophy and heart failure, arrythmias, and sudden cardiac death. The mechanotransduction mechanism by which dysregulated sarcomeric force production is sensed and leads to pathological remodeling remains poorly understood in HCM, thereby inhibiting the efficient development of new therapeutics. Our discovery was based on insights from a severe phenotype of an individual with HCM and a second genetic alteration in a sarcomeric mechano-sensing protein. We effectively derived cardiomyocytes from patient-specific induced pluripotent stem cells (iPSC-CMs) and developed robust engineered heart tissues (EHTs) by seeding iPSC-CMs into a laser-cut scaffold possessing native cardiac fiber alignment, for studying human cardiac mechanobiology at both cellular and tissue levels. Coupled with computational modeling for muscle contraction and rescue of disease phenotype via gene editing and pharmacological interventions, we have identified a new mechanotransduction pathway in HCM. Enhanced actomyosin crossbridge formation caused by sarcomeric mutations in cardiac myosin heavy chain (MYH7) led to increased force generation, which when coupled with slower twitch relaxation, destabilized the muscle LIM protein (MLP) stretch-sensing complex at the Z-disc. Subsequent reduction in the sarcomeric MLP level caused disinhibition of calcineurin–nuclear factor of activated T-cells (NFAT) signaling, which promoted cardiac hypertrophy. By mitigating enhanced actomyosin crossbridge formation through either genetic or pharmacological means, we alleviated stress at the Z-disc, preventing the development of hypertrophy associated with sarcomeric mutations. This proposal will dissect the roles of systolic and diastolic Z-disc stress in modulating the MLP mechanosensory complex and elucidate the molecular mechanisms that mediate the repression of calcineurin/NFAT by MLP as well as MLP protein degradation by stretch-sensing. We have recently developed a new bioreactor that can expose EHTs to precisely prescribed afterloads, so we can test the hypothesis that higher systolic forces produced by crossbridges under higher afterloads destabilize MLP at the Z-disc and activate hypertrophic signaling during systole. Additionally, EHTs will be subjected to culture under conditions of either constant length or diastolic stretch to mimic ventricular filling. After repeated stretching, EHTs will be examined for hypertrophic signaling. We will unravel mechanistic insights into how saromeric MLP is degraded in response to Z-disc stress. In addition, we will dissect molecular mechanisms by which MLP inhibits calcineurin/NFAT hypertrophic responses in systole and diastole. Elucidation of the molecular mechanisms of a common sarcomeric contraction/MLP/calcineurin mechanotransduction pathway will help to design novel strategies for a wide spectrum of heart failure patients potentially through stabilizing the Z-disk MLP mechanosensory complex.

家族性肥厚型心肌病 (HCM) 是最常见的遗传性心脏病，通常由以下原因引起：由编码调节心肌收缩力的肌节蛋白的基因突变引起的，包括：左心室肥厚和心力衰竭、心律失常和心源性猝死。感知肌节力产生失调并导致病理重塑的机制对 HCM 的了解仍知之甚少，从而阻碍了新疗法的有效开发。是基于对患有 HCM 的个体的严重表型和第二个基因改变的见解我们有效地从患者特异性诱导的心肌细胞中获得。多能干细胞 (iPSC-CM) 并通过将 iPSC-CM 接种到体内，开发出强大的工程心脏组织 (EHT) 具有天然心脏纤维排列的激光切割支架，用于研究人类心脏力学生物学结合细胞和组织水平的肌肉收缩和疾病救援的计算模型。通过基因编辑和药理学干预，我们发现了一种新的机械转导 HCM 中心肌肌球蛋白肌节突变引起的肌动球蛋白横桥形成增强。重链（MYH7）导致力量产生增加，当与较慢的抽搐放松相结合时，使 Z 盘处的肌肉 LIM 蛋白 (MLP) 拉伸感应复合物不稳定。肌节 MLP 水平导致钙调神经磷酸酶 - 激活 T 细胞核因子 (NFAT) 信号传导去抑制，通过减轻增强的肌动球蛋白横桥形成来促进心脏肥大。通过遗传或药理学手段，我们减轻了 Z 盘的压力，防止肥大的发展该提案将剖析收缩期和舒张期 Z 盘应力的作用。调节 MLP 机械感觉复合体并阐明介导该复合体的分子机制我们最近通过 MLP 抑制钙调神经磷酸酶/NFAT 以及通过拉伸感应降解 MLP 蛋白。开发了一种新的生物反应器，可以将 EHT 暴露于精确规定的后负荷中，因此我们可以测试假设在较高的后负荷下，横桥产生的较高的收缩力会破坏 MLP 的稳定性此外，EHT 将在收缩期进行培养。恒定长度或舒张期拉伸的条件以模拟心室充盈。我们将检查 saromeric MLP 的肥大信号传导机制。此外，我们将剖析 MLP 抑制的分子机制。钙调神经磷酸酶/NFAT 在收缩期和舒张期的肥大反应的分子机制的阐明。共同的肌节收缩/MLP/钙调神经磷酸酶机械转导途径将有助于设计新颖的通过稳定 Z 盘 MLP 机械感觉，可能为广泛的心力衰竭患者提供策略复杂的。