A Novel Role for NFATC1 in Modulating Cardiac Excitability

项目概要/摘要 这项提案的总体目标是探索NFATC 1作为一种新的神经递质的分子和电生理作用。 心房颤动（AF）易感基因，并确定以前未知的NFATC 1对心房颤动（AF）易感基因的作用。 兴奋性房颤是临床上最常见的持续性心律失常， 每年超过70亿美元的医疗费用。新出现的证据表明心脏转录因子与 两种家族性房颤和普通人群房颤的发病机制。我们发现了一种突变， 心脏转录因子NFATC 1在一个由年轻发病AF定义的高危犹他州家系中的表达。 一种依赖性转录因子，被认为在心脏发育中起作用，但到目前为止， 与心脏兴奋性有关。我们令人兴奋的初步数据确定了NFATC 1在调节 心房兴奋性，在NFATC 1缺失斑马鱼中，发展自发性房性快速性心律失常和幼年突发性 死亡目的1试图确定突变NFATC 1的生物化学、分子和电生理基础 功能障碍，使用HL-1心房细胞系，人类细胞培养模型（患者特异性和基因组编辑 诱导的多能干细胞衍生的心肌细胞，iPSC-CM）和整个动物模型（转基因 斑马鱼）。目的2通过探索NFATC 1在心房兴奋性调节中的分子机制， 和电生理基础的心房快速性心律失常在nfatc 1敲除斑马鱼。目标3将定义NFATC 1- 控制转录网络和基因通路，调节心脏兴奋性，使用单细胞RNA- 人心房和NFATC 1 null和WT iPSC-CM中的Seq、ChIP-Seq和ChIP-质谱。 我们的提案利用了人类遗传学、基因组编辑技术、最先进的下一代测序技术， 模式和生物信息学，以及电生理学，以全面表征NFATC 1的新作用 心脏兴奋性和房颤发病机制。对调控离子的关键转录网络的理解 通道基因表达和心房兴奋性将提供一个更广泛，更全面的了解 心律失常易感性的研究，并为新型房颤治疗奠定基础。

PROJECT SUMMARY / ABSTRACT The overall goal of this proposal is to explore the molecular and electrophysiological role of NFATC1 as a novel atrial fibrillation (AF) susceptibility gene and to define the previously unknown contribution of NFATC1 to atrial excitability. AF, the most common sustained arrhythmia encountered in clinical practice, has an economic burden exceeding $7 billion in annual health care costs. Emerging evidence implicates cardiac transcription factors in the pathogenesis in both familial forms of AF and AF in the general population. We identified a mutation in the cardiac transcription factor NFATC1 in a high-risk Utah pedigree defined by young onset AF. NFATC1 is a Ca2+- dependent transcription factor postulated to play a role in cardiac development, but up until now has never been associated with cardiac excitability. Our exciting preliminary data identify a novel role for NFATC1 in modulating atrial excitability, in that nfatc1 null zebrafish develop spontaneous atrial tachyarrhythmia and juvenile sudden death. Aim 1 seeks to define the biochemical, molecular and electrophysiological basis of the mutant NFATC1 dysfunction, using the HL-1 atrial cell line, a human cell culture model (patient-specific and genome-edited induced pluripotent stem cell derived cardiomyocytes, iPSC-CMs), and a whole animal model (transgenic zebrafish). Aim 2 characterizes the role of NFATC1 in modulating atrial excitability by exploring the molecular and electrophysiological basis for the atrial tachyarrhythmia in nfatc1 null zebrafish. Aim 3 will define NFATC1- controlled transcriptional networks and gene pathways that regulate cardiac excitability, using single-cell RNA- Seq, ChIP-Seq and ChIP-Mass Spectroscopy in human atrium and NFATC1 null and WT iPSC-CMs. Our proposal leverages human genetics, genome-editing techniques, state-of-the-art Next-Gen sequencing modalities and bioinformatics, and electrophysiology to comprehensively characterize the novel role of NFATC1 in cardiac excitability and AF pathogenesis. An understanding of a key transcriptional network that regulates ion channel gene expression and atrial excitability will provide a broader, and more comprehensive understanding of arrhythmia susceptibility and lay the foundation for novel AF therapies.