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.

家族性肥厚心肌病（HCM）是最常见的遗传性心脏病，通常是引起的通过编码调节心脏收缩率的肉瘤蛋白的基因突变。 HCM表现包括左心室肥大和心力衰竭，芳香症和心脏猝死。机械转导感测失调的肌肉力产生并导致病理重塑的机制在HCM中仍然了解不足，从而抑制了新疗法的有效发展。我们的发现是基于来自患有HCM的个体的严重表型的见解和A中的第二个遗传改变肉瘤机械感应蛋白。我们从患者特异性诱导的有效衍生的心肌细胞衍生多能干细胞（IPSC-CM），并通过将IPSC-CM播种到激光切割脚手架潜在的本地心脏纤维比对，用于研究两者的人类心脏机制细胞和组织水平。结合用于肌肉收缩和疾病营救的计算建模通过基因编辑和药物干预措施表型，我们已经确定了一种新的机械转移 HCM中的途径。由心脏肌球蛋白中的肉瘤突变引起的肌动菌素十字桥形成重链（MYH7）导致力增加，当较慢的抽搐放松时，在Z盘处不稳定肌肉lim蛋白（MLP）拉伸感应复合物。随后减少肉瘤MLP水平引起激活T细胞（NFAT）信号的钙调神经磷酸酶 - 核因子的抑制作用，促进心脏肥大。通过减轻增强的肌动菌素Crossbridge形成遗传或药理学手段，我们减轻了Z二轴的压力，阻止了肥大的发展与肉型突变有关。该建议将剖析收缩和舒张期应力的作用在调节MLP机理时复合物并阐明介导的分子机制通过拉伸感应抑制MLP和MLP蛋白质降解的抑制。我们最近有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载，因此我们可以测试假设Crossbridges在较高的后负荷下产生的较高的收缩力使MLP处于 Z二轴并激活收缩期肥厚的信号传导。此外，EHT将受到培养恒定长度或舒张期为模拟心室填充的条件。重复拉伸后，EHTS 将检查肥厚的信号传导。我们将揭示机械洞察讽刺MLP的洞察力响应于Z二盘应激而退化。另外，我们将剖析MLP抑制的分子机制钙调神经蛋白/NFAT在收缩和舒张中的肥大反应。阐明A的分子机制常见的肉瘤收缩/MLP/钙调神经蛋白机械转导途径将有助于设计新颖通过稳定Z-DISK MLP机制，广泛心力衰竭患者的策略有可能复杂的。