Etv1 is an Essential Regulator of Fast Conduction Tissues in the Heart

Etv1 是心脏快速传导组织的重要调节器

• 批准号: 9893031
• 负责人: David S Park
• 金额: $ 42.38万
• 依托单位: NEW YORK UNIVERSITY SCHOOL OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-04-01 至 2022-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9893031
• 关键词: Adult; Affect; African American; Age; Attenuated; Binding; Binding Sites; Biological Assay; Biophysics; Bundle-Branch Block; CRISPR/Cas technology; Cardiac; Cardiac Myocytes; Cardiomyopathies; Cells; Connexins; DNA Binding; Data; Defect; Disease; ETV1 gene; Electrophysiology (science); Exhibits; Failure; Family; Gene Expression; Gene Expression Profiling; Genes; Genetic Transcription; Glycine; Goals; Heart; Heart Atrium; Heart Block; Heart Contractilities; Heart failure; Heritability; Human; Knock-out; Knockout Mice; MAP Kinase Gene; Mediating; Mediator of activation protein; Molecular; Morbidity - disease rate; Mus; Muscle Cells; Myocardium; NRG1 gene; Neonatal; Neuregulin 1; Neurons; Nuclear; Optics; Pathologic; Patients; Pharmacology; Phenotype; Positioning Attribute; Predisposition; Property; Protein Isoforms; Proteins; Rattus; Regulator Genes; Role; Serine; Signal Pathway; Signal Transduction; Site-Directed Mutagenesis; Skeletal Muscle; Sodium; Sodium Channel; Stress; Structural defect; Syndrome; System; Techniques; Technology; Tetrodotoxin; Therapeutic; Tissues; Variant; Ventricular; Ventricular Arrhythmia; atrioventricular node; biophysical properties; cell type; experimental study; heart rhythm; improved; in vivo; indium arsenide; man; member; mortality; neuromuscular; novel therapeutics; patch clamp; programs; promoter; transcription factor

PROJECT SUMMARY Rapid impulse propagation through the atria and ventricular conduction system (VCS) is critical for normal cardiac activation and contractility. Heritable and acquired syndromes affecting conduction velocity in these tissues account for a significant burden of arrhythmic disease and are a major cause of morbidity and mortality. Unfortunately, no therapeutic options exist for improving atrial and VCS conduction due to poor understanding of the gene regulatory networks. In order to identify essential regulators of the fast conduction gene program, we made use of a previous observation that Neuregulin-1 (NRG1) is the key mediator of VCS specification. Using a signal transduction and VCS transcriptional profiling screen, we discovered that NRG1 mediates fast conduction in the heart through the Ras-MAPK-RSK/MSK signaling pathway and the transcription factor ETV1. ETV1 is a member of the Pea3 group of E-twenty-six (ets) family transcription factors that regulates specification and electrophysiological modulation of neuronal cell types. We now present data demonstrating a critical role of ETV1 in establishing and maintaining the fast conduction gene program in the heart. ETV1 is highly expressed in the atrial pectinated myocardium and VCS, where it up-regulates the expression of key cardiac conduction genes, Nkx2-5, Scn5a (Nav1.5), and Gja5 (Cx40). Consequently, Etv1 KO mice exhibit conduction slowing in the atria and VCS with a subset displaying frank bundle branch block. Patch clamp experiments demonstrated that the normal biophysical differences in the sodium current between atrial, VCS, and ventricular myocytes were lost in Etv1 KO mice, suggesting that ETV1 regulates additional modifiers of the cardiac sodium current beyond Scn5a. Etv1 KO mice also displayed VCS hypoplasia with a proportion showing absence of the right bundle branch (RBB), mirroring the defects seen in NKX2-5 haploinsufficient mice and patients. Analysis of the NKX2-5 promoter identified a highly conserved ets-binding cluster that upon deletion using CRISPR-Cas9 in vivo recapitulated failure of RBB formation. We performed PheWAS analysis and found an association between an ETV1 sequence variant and bundle branch blocks in humans. To further explore the role of ETV1 as a transcriptional regulator of the fast conduction phenotype, we propose the following specific aims: i) determine the mechanism by which ETV1 regulates the unique biophysical properties of the sodium current in atrial and Purkinje myocytes, ii) study the functional role of ETV1 in cardiac conduction and arrhythmogenesis in the adult heart, and iii) elucidate the molecular basis of bundle branch block in carriers of the ETV1 sequence variant and in Etv1 KO mice.

项目概要 通过心房和心室传导系统 (VCS) 的快速脉冲传播对于正常情况至关重要 心脏激活和收缩力。影响这些疾病传导速度的遗传性和获得性综合征 组织对心律失常疾病造成重大负担，并且是发病和发病的主要原因 死亡。不幸的是，由于心房和 VCS 传导不良，不存在改善心房和 VCS 传导的治疗选择。 了解基因调控网络。为了确定快速传导的重要调节器 基因程序中，我们利用了之前的观察结果，即 Neuregulin-1 (NRG1) 是 VCS 的关键介质 规格。使用信号转导和 VCS 转录谱筛选，我们发现 NRG1 通过 Ras-MAPK-RSK/MSK 信号通路介导心脏的快速传导 转录因子ETV1。 ETV1 是 E-26 (ets) 转录家族 Pea3 组的成员 调节神经元细胞类型的规范和电生理调节的因素。我们现在呈现 数据证明 ETV1 在建立和维持快速传导基因程序中的关键作用 心脏。 ETV1 在心房梳状心肌和 VCS 中高度表达，在此处上调 关键心脏传导基因 Nkx2-5、Scn5a (Nav1.5) 和 Gja5 (Cx40) 的表达。因此，Etv1 KO 小鼠表现出心房和 VCS 传导减慢，其中一部分表现出弗兰克束支传导阻滞。 膜片钳实验表明，钠电流的正常生物物理差异 在 Etv1 KO 小鼠中，心房肌细胞、VCS 肌细胞和心室肌细胞之间的信号丢失，表明 ETV1 调节 Scn5a 之外的心脏钠电流的附加调节剂。 Etv1 KO 小鼠也表现出 VCS 发育不全，其中一部分显示缺乏右束支（RBB），反映了在 NKX2-5 单倍体不足的小鼠和患者。 NKX2-5 启动子的分析鉴定出高度保守的 ets 结合簇，在体内使用 CRISPR-Cas9 删除后，重现了 RBB 形成的失败。我们 进行 PheWAS 分析，发现 ETV1 序列变异与束支之间存在关联 人类体内的阻塞。进一步探讨ETV1作为快速传导转录调节因子的作用 表型，我们提出以下具体目标： i) 确定 ETV1 调节表型的机制 心房和浦肯野肌细胞钠电流的独特生物物理特性，ii) 研究钠电流的功能作用 ETV1 在成人心脏的心脏传导和心律失常发生中的作用，以及 iii) 阐明了 ETV1 序列变异携带者和 Etv1 KO 小鼠的束支传导阻滞。