The molecular mechanisms underlying arrhythmogenic right ventricular dysplasia/cardiomyopathy

致心律失常性右心室发育不良/心肌病的分子机制

• 批准号: 8884263
• 负责人: Farah Sheikh
• 金额: $ 38.75万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN DIEGO
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-04-01 至 2019-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8884263
• 关键词: Accounting; Adult; Affect; Arrhythmogenic Right Ventricular Dysplasia; Autophagocytosis; Autophagosome; Behavior; Binding; Biochemical; Biological Models; Biology; Cardiac; Cardiac Myocytes; Cardiomyopathies; Cells; Clinical; Complex; Congenital Heart Defects; Connexins; DNA Sequence Alteration; Data; Defect; Desmosomes; Diagnosis; Disease; Employee Strikes; Event; Exhibits; Family; Funding; Generations; Genes; Genetic; Genetic Models; Goals; Grant; Health; Heart; Heart Diseases; Human; In Vitro; Inherited; Intercellular Junctions; Knockout Mice; Link; Lysosomes; Mediating; Microscopy; Modeling; Molecular; Molecular Genetics; Morphology; Mus; Mutation; Myocardium; Patients; Physiological; Physiology; Protein Family; Proteins; Role; SNAP receptor; Structure; Sudden Death; Testing; Validation; Yeasts; base; desmoplakin; effective therapy; human tissue; in vivo; induced pluripotent stem cell; insight; lentiviral-mediated; loss of function; member; mouse model; novel; overexpression; protein degradation; protein function; public health relevance; small hairpin RNA; soluble NSF attachment protein; sudden cardiac death; targeted treatment; tool; yeast two hybrid system

 DESCRIPTION (provided by applicant): This is an application for a competitive renewal of our grant R01 HL095780-01. We were originally funded to investigate mechanisms underlying the role of the known central desmosomal component, desmoplakin, in the clinical and cellular features associated with the genetic-based heart disease, arrhythmogenic right ventricular cardiomyopathy (ARVC) that causes sudden death in the young, by generating and characterizing novel desmoplakin deficient model systems. For this application, we uncovered synaptosomal associated protein 29 (SNAP29) as a novel desmoplakin associated protein in the adult human heart in a yeast-two hybrid screen that we show has relevance to ARVC, by leveraging our novel genetic mouse and human cardiac models of ARVC. Although the role of SNAP29 is unknown in the heart, we show that SNAP29 co-localizes to cardiac muscle desmosomal cell-cell junctions in the adult mouse and human heart as well as human induced pluripotent stem cell derived cardiac cells (hiPSC). Furthermore, SNAP29 localization and/or levels at desmosomal junctions are lost in hearts from our mouse model of ARVC and ARVC hiPSC-derived cardiac cells that exhibit striking desmosomal defects and arrhythmogenic behavior. Generation of novel SNAP29 deficient mouse models (global and cardiomyocyte-specific) revealed striking cardiac defects including (i) autophagic defects at the cardiac muscle cell junction (accumulation of autophagic/lysosomal markers and structures at the cell junction) that specifically impacted desmosomal protein levels and (ii) cardiac morphology defects. Data from our mouse model of ARVC provides validation to this mechanism as we reveal that their hearts exhibit similar defects in autophagic control at the cardiac muscle cell junction. We hypothesize that SNAP29 regulates desmosomal protein levels and function in cardiac muscle by controlling desmosomal turnover via autophagy-mediated mechanisms and its loss will trigger loss of desmosomal protein levels as well as function and ultimately cause ARVC. We aim to determine: (i) the functional role of SNAP29 in the heart by characterizing SNAP29 loss of function mouse models, (ii) the relevance of SNAP29-DSP interaction in human ARVC and cardiomyocytes by expressing human ARVC mutations and using hiPSCs as a tool, and (iii) the SNAP29-dependent events in autophagy that control desmosomal levels/turnover, by analyzing defects in cardiac autophagy (induction and flux) and relevant desmosome targets using SNAP29 loss of function models and overexpression of SNAP29 in an in vitro ARVC model.

 描述（由应用程序提供）：这是对我们授予R01 HL095780-01的竞争续订的申请。我们最初是为了研究已知中心脱糖体成分（脱莫普拉金）在与基于遗传性心脏病相关的临床和细胞特征中的作用的基础机制，心律失常右心室心肌病（ARVC）通过产生和表征新颖的Desmoplakin Defmoplakin Deficmoplakin模型模型。对于此应用，我们通过利用我们的新型ARVC的新型遗传小鼠和人类心脏模型，在酵母 - 两种杂种筛选中发现了成年人心脏中的新型脱莫皮拉金相关蛋白作为成年人心脏中的新型脱莫皮拉蛋白相关蛋白的新型脱氨木蛋白相关蛋白的新型demoplakin相关蛋白。尽管SNAP29在心脏中的作用尚不清楚，但我们表明SNAP29在成年小鼠和人心脏以及人类诱导的多能干细胞衍生心脏细胞（HIPSC）中共定位到心肌肌肉脱骨细胞 - 细胞连接（HIPSC）。此外，SNAP29在脱染色体连接处的定位和/或水平在我们的ARVC和ARVC HIPSC衍生的心脏细胞的心脏中丧失，这些心脏衍生的心脏细胞暴露了引人注目的脱发缺陷和心律失常行为。 Generation of novel SNAP29 defensive mouse models (global and cardiomyocyte-specific) revealed striking cardiac defects including (i) autophagic defects at the cardiac muscle cell junction (accumulation of autophagic/lysosomal markers and structures at the cell junction) that specifically impacted desmosomal protein levels and (ii) cardiac morphology defects.我们的ARVC小鼠模型的数据为这种机制提供了验证，因为我们揭示他们的心脏在心肌细胞连接处暴露了相似的自噬对照缺陷。我们假设SNAP29通过通过自噬介导的机制来控制脱骨液的转换来调节心肌肌肉蛋白水平和功能，并且其损失将触发脱发蛋白水平以及功能的丧失，并最终引起ARVC。我们的目的是确定：（i）SNAP29在心脏中的功能作用，表征SNAP29功能鼠标模型的丧失，（ii）SNAP29-DSP相互作用在人ARVC和心肌细胞中的相关性，通过表达人类ARVC突变并使用HIPSC作为工具和（III）在SNAP29依赖性的范围内通过HIPSCS来表达人类ARVC突变，以及（III）。在体外ARVC模型中，使用SNAP29函数模型丧失和SNAP29的过表达，在心脏自噬（感应和通量）和相关的脱骨靶标中。