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: 9311687
• 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/9311687
• 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; 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.

项目摘要 快速冲动通过心房和心室传导系统（VC）对正常至关重要 心脏激活和收缩力。可遗传和获得的综合症影响这些传导速度 组织造成心律不齐的重大负担，是发病率和 死亡。不幸的是，由于较差而没有用于改善心房和VCS的治疗选择 了解基因调节网络。为了确定快速传导的基本调节剂 基因程序，我们利用了先前的观察结果，即神经蛋白-1（NRG1）是VC的关键介体 规格。使用信号转导和VCS转录分析屏幕，我们发现NRG1 通过RAS-MAPK-RSK/MSK信号通路介导心脏中的快速传导和 转录因子ETV1。 ETV1是E-Twient（ET）家族转录的PEA3组成员 调节神经元细胞类型的规范和电生理调节的因素。我们现在在场 数据证明了ETV1在建立和维持快速传导基因程序中的关键作用 心。 ETV1在心房胸膜的心肌和VC中高度表达，它在其中上调了 关键心脏传导基因，NKX2-5，SCN5A（NAV1.5）和GJA5（CX40）的表达。因此，ETV1 KO小鼠在心房和VC中表现出带有弗兰克束支块的子集的传导。 斑块夹实验表明钠电流的正常生物物理差异 在ETV1 KO小鼠中丢失了心房，VC和心室肌细胞之间，表明ETV1调节 SCN5A以外的心脏钠电流的其他修饰符。 ETV1 KO小鼠还显示了VCS 低浮力，比例显示不存在正确的束分支（RBB），反映了所见的缺陷 NKX2-5单倍体的小鼠和患者。 NKX2-5启动子的分析确定了高度保守的 使用CRISPR-CAS9在体内概括的RBB形成失败时，ETS结合群集在删除后。我们 进行了PHEWAS分析，发现ETV1序列变体与束分支之间的关联 人类的块。进一步探索ETV1作为快速传导的转录调节剂的作用 表型，我们提出以下特定目的：i）确定ETV1调节的机制 钠电流在心房和浦肯野肌细胞中的独特生物物理特性，ii）研究 ETV1成人心脏的心脏传导和心律失常发生，iii）阐明了分子基础 ETV1序列变体和ETV1 KO小鼠中的载体中的束支块。