Ryanodine Receptor Defects in Cardiomyopathy Caused by Lamin A/C Gene Mutations

Lamin A/C 基因突变引起的心肌病中的 Ryanodine 受体缺陷

基本信息

批准号：
9904328
负责人：
ANDREW Robert MARKS
金额：
$ 45.3万
依托单位：
COLUMBIA UNIVERSITY HEALTH SCIENCES
依托单位国家：
美国
项目类别：
财政年份：
2019
资助国家：
美国
起止时间：
2019-04-04 至 2023-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9904328
关键词：
3-Dimensional Affect Amino Acids Apoptosis Arrhythmia Caliber Cardiac Cardiac Myocytes Cardiomyopathies Cell Differentiation process Cell Nucleus Cells Clinical Trials Cultured Cells DNA Damage Data Defect Dilated Cardiomyopathy Disease Disease model Filament Gene Mutation Genes Goals Heart Heart Diseases Heart failure Hereditary Disease Human Incidence Inherited Intermediate Filament Proteins Joints Knockout Mice Laboratories Lamin Type A Lamins Lead Life MAP2K1 gene MAPK3 gene Maps Membrane Mitochondria Mitogen-Activated Protein Kinase Kinases Modification Molecular Mus Muscular Dystrophies Mutant Strains Mice Mutation Myocardial dysfunction Myocardium Nuclear Envelope Nuclear Lamin Nuclear Lamina Oxidative Stress Oxides Pathogenesis Pathogenicity Pathologic Pathology Patients Peptide Hydrolases Pharmaceutical Preparations Pharmacotherapy Phenotype Physiological Process Production Proteins Proteomics Rare Diseases Reactive Oxygen Species Research RyR2 Ryanodine Receptor Calcium Release Channel Ryanodine Receptors Sarcoplasmic Reticulum Savings Signal Transduction Skeletal Muscle Striated Muscles Structure Sudden Death Testing Tissue Model Tissues Translating Translations Variant Work clinical development experimental study heart function human disease human model human subject human tissue improved inhibitor/antagonist mitochondrial dysfunction mouse model novel novel therapeutics pre-clinical prevent protein structure small molecule three dimensional structure virtual

项目摘要

Project Summary Dilated cardiomyopathy caused by mutations in the lamin A/C gene (LMNA) encoding A-type nuclear lamins is a life-threatening disease with no definitive cure. The pathogenic mechanisms responsible for cardiomyopathy in this inherited disease are poorly understood. In particular, it is not known how alterations in proteins expressed in nuclei of virtually all terminally differentiated cells selectively cause heart disease. Our hypothesis is that alterations in A-type lamins predispose cells to oxidative stress-induced remodeling of ryanodine receptors (RyRs), creating a sarcoplasmic reticulum (SR) Ca2+ “leak.” Oxidative stress and increased cytosolic Ca2+ also contribute to hyper-activation of extracellular signal-regulated kinases 1 and 2 (ERK1/2), which occurs in cardiomyopathy caused by LMNA mutations. The increased cytosolic Ca2+ and ERK1/2 activity generates various defects, including mitochondrial dysfunction, that cause cardiomyopathy. A corollary of our hypothesis is that blocking the SR Ca2+ “leak” will have beneficial effects in cardiomyopathy caused by LMNA mutations. Using mouse models of the disease and human tissue, we will test our hypothesis and its corollary. In Aim 1, we will determine if alterations in A-type lamins that cause cardiomyopathy lead to enhanced cardiac muscle oxidative stress, resultant RyR2 remodeling and a SR Ca2+ “leak.” We will also determine if the SR Ca2+ “leak” stimulates ERK1/2 activity, causes mitochondrial dysfunction and damages DNA. In addition to heart, we will similarly examine skeletal muscle, which is often simultaneously affected in human patients with cardiomyopathy caused by LMNA mutations as well as in model mice. We will further assess these processes in cultured cells that stably express a cardiomyopathy-causing lamin A variant or lack A-type lamins. In Aim 2, we will utilize the three-dimensional structure of RyR to determine how specific oxidative modifications that occur in striated muscle of Lmna mutant mice affect its structure and make it “leaky” to Ca2+. In Aim 3, we will perform experiments to determine if a Rycal, drugs that stabilize remodeled RyRs and block the SR Ca2+ “leak,” improves heart function and prolongs survival in Lmna mutant mice and if it blocks the “leak” in hearts from human subjects with cardiomyopathy caused by LMNA mutations. We will further determine if a Rycal has synergistically beneficial effects when combined with an inhibitor of ERK1/2 activity, which has previously been shown to partially improve heart function in Lmna mutant mice with cardiomyopathy. These studies will reveal basic information about the pathogenesis of cardiomyopathy caused by LMNA mutations and connect an intranuclear protein defect with a tangible mechanism of cardiac dysfunction. They will also determine if drugs already in clinical development can be translated to trials in patients with this lethal heart disease.

项目摘要由编码A型核层粘连蛋白的层粘连蛋白A/C基因（LMNA）突变引起的扩张心肌病是危及生命的疾病，没有明确的治愈方法。导致心肌病的致病机制在这种遗传疾病中，人们的理解很少。特别是，尚不知道蛋白质的改变是如何的在几乎所有终末分化的细胞中，在核表达有选择地引起心脏病。我们的假设是A型层粘蛋白的改变易于抗氧化应激诱导的Ryanodine重塑受体（RYRS），产生肌浆网（SR）Ca2+“泄漏”。氧化应激和胞质增加 Ca2+还导致细胞外信号调节激酶1和2（ERK1/2）的过度激活，这发生在由LMNA突变引起的心肌病中。胞质Ca2+和ERK1/2活性增加产生各种缺陷，包括导致心肌病的线粒体功能障碍。我们的必然假设是阻止SR Ca2+“泄漏”将对由LMNA引起的心肌病具有有益的作用突变。使用疾病和人体组织的小鼠模型，我们将检验我们的假设及其推论。在AIM 1中，我们将确定导致心肌病的A型层粘连的改变是否导致心脏增强肌肉氧化应激，由此产生的RYR2重塑和SR Ca2+“泄漏”。我们还将确定SR是否 Ca2+“泄漏”刺激ERK1/2活性，导致线粒体功能障碍并损坏DNA。此外心脏，我们会类似地检查骨骼肌，骨骼肌通常只是在人类患者患者中受到影响由LMNA突变以及模型小鼠引起的心肌病。我们将进一步评估这些过程在AIM 2中，我们将利用RYR的三维结构来确定特定的氧化修饰是如何的在AIM 3中，我们将执行实验以确定Rycal是否稳定重塑的Ryrs并阻止SR Ca2+的药物 “泄漏”可以改善心脏功能并延长LMNA突变小鼠的生存，如果它阻止了心脏的“泄漏” 来自由LMNA突变引起的心肌病的人类受试者。我们将进一步确定Rycal是否具有当与ERK1/2活性的抑制剂结合使用时，协同有益的效果显示出患有心肌病的LMNA突变小鼠的心脏功能。这些研究将揭示有关LMNA突变引起的心肌病发病机理的基本信息，并将内部蛋白质缺陷，具有心脏功能障碍的切实机制。他们还将确定是否药物临床发育中已经可以转化为这种致命心脏病患者的试验。