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。尽管在解体方面取得了进展 关于扩张型心肌病的遗传学基础，我们对分子事件和信号转导的理解仍有很大差距 从突变到不同疾病表型的途径。最近新技术的出现， 如患者特异性诱导多能干细胞(IPSCs)和基因组编辑(CRISPR/Cas9)，提供了 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 结合这些突破性技术，我们现在准备解决 家族性DCM，即从与DCM相关的数量不断增加的DCM中获得的基因-表型关系 基因突变。我们建议的总体目标是利用一种多学科方法，将 针对患者的IPSCs、基因组编辑、基因屏幕、下一代测序技术和 转基因动物模型，以获得对基因-表型关联的新见解，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， 内质网未折叠蛋白反应(UPR)在DCM发病机制中的作用 患者特定的IPSC-CMS。修订后的提案的中心假设是某些DCM突变 改变钙稳态，引起慢性内质网应激，导致UPR信号的长时间激活。我们 将追求三个具体目标。目标一：我们将建立一个研究基因的实验平台-- 心肌肌钙蛋白T(TNNT2)和磷蛋白(PLN)基因变异的表型相关性 在目标2：我们将破译ER应激和UPR激活在遗传性DCM中的作用；在目标3： 在体内探讨与TNNT2突变相关的DCM发病机制。我们有 组建了一支拥有广泛互补和综合专业知识的多学科团队。我们有 提供了令人信服的初步数据，以支持我们以假设为导向的研究建议的合理性， 我们已经做好了准备，在五年内实现项目目标。如果成功，我们的研究将提供 家族性扩张性心肌病发病机制和治疗的新范式。

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.