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.

项目摘要 通过心房和心室传导系统（VVT）的快速脉冲传播对于正常的心功能至关重要。 心脏激活和收缩性。遗传性和获得性综合征影响传导速度， 组织是疟疾的重要负担，是发病的主要原因， mortality.不幸的是，由于心房和心房传导不良， 了解基因调控网络。为了确定快速传导的基本调节器， 基因程序，我们利用了以前的观察，即神经调节蛋白-1（NRG 1）是细胞凋亡的关键介质。 规范.使用信号转导和转录谱筛选，我们发现NRG 1 通过Ras-MAPK-RSK/MSK信号通路介导心脏快速传导， 转录因子ETV 1。ETV 1是E-twenty-six（ets）家族转录的Pea 3组的成员 调节神经元细胞类型的特化和电生理调节的因子。我们现在提出 数据表明ETV 1在建立和维持快速传导基因程序中的关键作用， 心脏ETV 1在心房梳状心肌和心房肌中高表达，在心房肌和心房肌中，ETV 1上调心房肌细胞的增殖。 关键心脏传导基因Nkx 2 -5、Scn 5a（Nav1.5）和Gja 5（Cx40）的表达。因此，Etv 1 KO小鼠在心房和心房中表现出传导减慢，其中一个子集表现出明显的束支分支阻滞。 膜片钳实验表明，钠电流的正常生物物理差异， 在Etv 1基因敲除小鼠中，心房、心房和心室肌细胞之间的差异消失，表明ETV 1调节 Scn 5a以外的心脏钠电流的其他修饰剂。Etv 1 KO小鼠也显示出 发育不全，部分显示右束支分支（RBB）缺失，反映了 NKX 2 -5单倍不足小鼠和患者。对NKX 2 -5启动子的分析鉴定了一个高度保守的 在体内使用CRISPR-Cas9缺失后，ets结合簇重现了RBB形成的失败。我们 进行了PheWAS分析，发现ETV 1序列变异与束分支之间存在关联 人体内的积木为了进一步探讨ETV 1作为快速传导的转录调节因子的作用， 表型，我们提出了以下具体目标：i）确定ETV 1调节表型的机制， 心房和浦肯野肌细胞中钠电流的独特生物物理特性，ii）研究 ETV 1在成人心脏的心脏传导和心肌发生中的作用，以及iii）阐明ETV 1的分子基础。 ETV 1序列变异体携带者和Etv 1 KO小鼠中的束支分支阻滞。