Nr2f1a promotes atrial maintenance and ventricular growth in the embryonic zebrafish heart

项目摘要/摘要 先天性心脏病是最常见的先天性畸形，也是导致先天性心脏病的主要原因。 出生缺陷与婴儿死亡有关。CHDS可以影响心脏内的许多不同结构，包括 房室间隔和流出道(OFT)房间隔缺损(ASD)通常与 心律失常和传导缺陷，这可能是由于对早期两者至关重要的基因突变而同时发生的 心腔的发育和窦房结(SAN)的发育 心脏的起搏细胞。虽然手术干预可以纠正一些先天性心脏病，但手术往往不能修复。 相关的传导缺陷。此外，心律失常是#年发病率和死亡率的主要原因。 患有先天性心脏病的成年人。孤儿核激素受体转录因子成员NR2F2的突变 家族，与多种类型的CHD有关，最常见的是ASD，但最近是室性和 还有很多缺陷也被报道过。NR2F2在两组患者的心房肌细胞(ACS)中均有特异性表达 人类、小鼠和小鼠的研究表明，Nr2f2是心房发育和维持所必需的； 然而，这些蛋白质在急性冠脉综合征中发挥作用的机制以及NR2F2突变如何导致 同时影响心房和脑室的先天性心脏病的谱系还不是很清楚。我们实验室最近的工作是 确定斑马鱼Nr2f1a在功能上等同于哺乳动物Nr2f2。我们使用斑马鱼的初步数据 已经揭示，在缺乏Nr2f1a的情况下，在ACS中存在SAN身份的渐进异位扩展。 此外，对分离的急性冠脉综合征的RNA-seq和atac-seq的整合分析表明，Nr2f1a抑制了 通过维持NKX2.5在急性冠脉综合征中的表达，构建核心的SAN基因调控网络(GRN)。在目标1中，我们将 验证Nr2f1a通过直接维持NKX2.5的表达来抑制SAN身份的假设。 此外，我们的初步数据揭示了Nr2f1a在心室发育中的新需求。在AIM 2，我们将检验Nr2f1a细胞非自主促进心室生长的假设。归根结底， 拟议的研究有可能阐明以前未知的分子和遗传病因 发现与NR2F2突变相关的先天性心律失常和影响房室的先天性心脏病 在人类身上。

Project Summary/Abstract Congenital heart defects (CHDs) are the most common type of congenital malformation and the leading cause of birth defect associated infant death. CHDs can affect many different structures within the heart, including the atrial and ventricular septa and outflow tract (OFT). Atrial septal defects (ASDs) are often associated with arrhythmias and conduction defects, which can occur concurrently due to mutations in genes vital for both early development of the cardiac chambers and development of the sinoatrial node (SAN), which houses the pacemaker cells of the heart. While surgical intervention can correct some CHDs, surgery often does not repair associated conduction defects. Furthermore, arrhythmias are the leading cause of morbidity and mortality in adults with CHDs. Mutations in NR2F2, a member of the orphan nuclear hormone receptor transcription factor family, have been associated with multiple types of CHDs, most commonly ASDs but recently ventricular and OFT defects have been reported as well. NR2F2 is specifically expressed in atrial cardiomyocytes (ACs) in both humans and mice, and mouse studies have shown that Nr2f2 is required for atrial development and maintenance; however, the mechanisms by which these proteins function within ACs and how mutations in NR2F2 result in a spectrum of CHDs affecting both the atria and ventricles are not well understood. Recent work from our lab has identified zebrafish Nr2f1a as the functional equivalent of mammalian Nr2f2. Our preliminary data using zebrafish has revealed that in the absence of Nr2f1a there is a progressive ectopic expansion of SAN identity within ACs. Furthermore, integration of RNA-seq and ATAC-seq analysis of isolated ACs suggests that Nr2f1a represses the core SAN gene regulatory network (GRN) by maintaining expression nkx2.5 within ACs. In Aim 1, we will test the hypothesis that Nr2f1a is required to repress SAN identity by directly maintaining expression of Nkx2.5. Additionally, our preliminary data has revealed a novel requirement for Nr2f1a in ventricular development. In Aim 2, we will test the hypothesis that Nr2f1a cell non-autonomously promotes ventricular growth. Ultimately, the proposed studies have the potential to illuminate previously unknown molecular and genetic etiology underlying congenital arrhythmias and CHDs affecting both the atria and ventricles associated with NR2F2 mutations found in humans.