Unraveling the pathogenesis of familial dilated cardiomyopathy towards precision medicine

项目摘要 扩张型心肌病（DCM）是心力衰竭的主要原因。遗传性DCM，在家庭中运行，现在是 更常见的诊断，占报告病例的一半。尽管在解开 DCM的遗传基础，我们对分子事件和信号传导的理解仍有很大的差距 从突变到不同疾病表型的途径。最近新技术的出现， 例如患者特异性诱导多能干细胞（iPSC）和基因组编辑（CRISPR/Cas9）， 这是一个研究遗传变异性和疾病易感性之间关系的前所未有的机会。通过 结合这些突破性的技术，我们现在准备解决其中一个最关键的问题， 家族性DCM，即来自不断增加的DCM相关的基因型-表型关系 基因突变我们建议的总体目标是利用多学科方法， 患者特异性iPSC、基因组编辑、基因筛选、下一代测序技术和 转基因动物模型，以获得新的见解，基因型-表型协会，并剖析 遗传性扩张型心肌病发病的分子机制。我们的初步研究表明， 扩张型心肌病发病机制中内质网未折叠蛋白反应（UPR）的研究 患者特异性iPSC-CM。修订提案的中心假设是某些DCM突变 改变Ca 2+稳态并引起慢性ER应激，导致UPR信号转导的延长激活。我们 将实现三个具体目标。目标一：建立一个基因型研究的实验平台， 心肌肌钙蛋白T（TNNT 2）和受磷蛋白（PLN）基因变异相关的表型关联 在目的2中：我们将破译ER应激和UPR激活在遗传性DCM中的作用;在目的3中： 探讨与体内TNNT 2突变相关的DCM发病机制。我们有 组建了一个多学科小组，拥有广泛的互补和综合专门知识。我们有 提供了令人信服的初步数据，以支持我们的假设驱动的研究提案的合理性， 我们有能力在五年内达到计划的目标。如果成功，我们的研究将提供 为了解家族性扩张型心肌病的发病机制和治疗提供了新的范例。

Project Summary Dilated cardiomyopathy (DCM) is a leading cause of heart failure. Genetic DCM, which runs in families, is now more commonly diagnosed, accounting for up to half of the reported cases. Despite the progress in unraveling the genetic basis of DCM, there is still a large gap in our understanding of the molecular events and signaling pathways that lead from a mutation to diverse disease phenotypes. The recent advent of new technologies, such as patient-specific induced pluripotent stem cells (iPSCs) and genome editing (CRISPR/Cas9), provide an unprecedented opportunity to study associations between genetic variability and disease susceptibility. By combining these breakthrough technologies, we are now poised to address one of the most critical issues in familial DCM, namely, the genotype-phenotype relationship from the ever-growing number of DCM-associated gene mutations. The overarching goal of our proposal is to utilize a multidisciplinary approach that integrates patient-specific iPSCs, genome editing, genetic screens, next generation sequencing technologies and transgenic animal models to gain novel insights into genotype-phenotype associations, and to dissect the molecular mechanism of genetic DCM pathogenesis. Our preliminary studies have implicated the activation of the unfolded protein response (UPR) in the endoplasmic reticulum (ER) in the pathogenesis of DCM in a model of patient-specific iPSC-CMs. The central hypothesis of the revised proposal is that certain DCM mutations alter Ca2+ homeostasis and cause chronic ER stress, leading to prolonged activation of the UPR signaling. We will pursue three specific aims. In aim 1: we will establish an experimental platform to study the genotype- phenotype association of cardiac troponin T (TNNT2) and phospholamban (PLN) gene variants associated with DCM; in aim 2: we will decipher the role of ER stress and UPR activation in genetic DCM; and in aim 3: interrogate the mechanisms of DCM pathogenesis associated with TNNT2 mutations in vivo. We have assembled a multi-disciplinary team with extensive complementary and integrated expertise. We have provided compelling preliminary data to support the soundness of our hypothesis-driven research proposal, and we are well positioned to achieve the project goals within five years. If successful, our studies will provide a new paradigm for understanding the pathogenesis and treatment of familial DCM.