WNT SIGNALING IN CARDIAC CONDUCTION AND ARRHYTHMOGENESIS

心脏传导和心律失常中的 WNT 信号传导

基本信息

批准号：
9198256
负责人：
STACEY Lynn RENTSCHLER
金额：
$ 38.39万
依托单位：
WASHINGTON UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2016
资助国家：
美国
起止时间：
2016-01-01 至 2020-11-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9198256
关键词：
Address Adipocytes Adipose tissue Adult Area Arrhythmia Binding Biological Assay Bone Morphogenetic Proteins Cardiac Cardiac Myocytes Cell Lineage Cells Child Congenital Heart Defects Connexins Data Defect Deposition Development Diagnostic Disease Electrophysiology (science)Embryo Embryonic Heart Enhancers Ensure Foundations Future Gap Junctions Gene Expression Gene Targeting Genes Genetic Genetic Transcription Genetic Variation Genomic Segment Heart Heart Atrium Human In Vitro Ion Channel Maintenance Massive Parallel Sequencing Measures Mediating Modeling Morbidity - disease rate Morphogenesis Morphology Mutagenesis Mutant Strains Mice Myocardial Myocardium Optics Pathway interactions Pattern Phenotype Phosphorylation Post-Translational Protein Processing Publications Regenerative Medicine Regulation Regulatory Element Resolution Role Signaling Protein Site Sodium Channel Structure Sudden Death Syndrome Techniques Testing Therapeutic Tissues Tricuspid Atresia Tricuspid valve structure Ventricular WNT Signaling Pathway Wolff-Parkinson-White Syndrome Work base beta catenin cell type chromatin immunoprecipitation design electrical property genetic manipulation genetic predictors genome wide association study genome-wide in vivo loss of function migration mortality mouse model mutant novel postnatal programs protein expression public health relevance transcription factor transcriptome sequencing

项目摘要

DESCRIPTION (provided by applicant): The atrioventricular canal is an important structure in the embryonic heart, involved in valve formation and in coordinating electrical impulse delay to ensure sequential activation and contraction of the atria and ventricles. Here we seek to understand how canonical Wnt signaling regulates the electrical programming of the atrioventricular (AV) junction through its regulation of ion channel gene expression and cardiac conduction. This area of study is significant because congenital and acquired arrhythmias, important causes of morbidity and mortality, may result from altered programs of gene expression that influence ion channel gene expression and cardiac conduction. Loss of canonical Wnt signaling within embryonic myocardium results in congenital heart defects involving the AV junction, including tricuspid valve atresia. Here we will investigate the mechanism for how Wnt signaling regulates morphologic development of the AV junction, as well as the electrical patterning of this tissue, with the following aims: 1. Delineate the mechanisms by which myocardial Wnt signaling regulates atrioventricular canal morphogenesis. Using genetic mouse models to perform gain- and loss-of-function of canonical Wnt signaling, we will assess the role of Wnt in regulating the proliferation, migration and differentiation of epicardial and endocardial cells within the AV junction. We will elucidate whether Wnt signaling is required for postnatal maintenance of the AV junction, and whether Wnt activation is sufficient to induce ectopic AV junctions in the postnatal heart. 2: Identify direct targets of canonical Wnt signaling that promote an atrioventricular junction phenotype. Based on our preliminary data, Wnt globally regulates the phenotype of the AV junction. We will perform chromatin immunoprecipitation (ChIP) for β-catenin, the key transcriptional effector of Wnt signaling, as well as enhancer mutagenesis assays, to determine how Wnt regulates the expression of the transcription factor Tbx3. We will perform RNA-sequencing and ChIP followed by massively parallel DNA sequencing (ChIP-seq) to identify novel putative downstream Wnt target genes and their regulatory elements. 3: Elucidate the mechanisms for Wnt-mediated regulation of cardiac conduction. Our preliminary data demonstrate that perturbation of Wnt signaling during development alters AV conduction and expression of sodium channels and gap junctions. Using ChIP-qPCR in gain- and loss-of-function mouse mutants, we will determine how sodium channel expression is regulated by Wnt signaling We will determine whether altered ventricular conduction velocity in Wnt mutant mice is associated with changes in Nav1.5 and/or gap junction protein expression and phosphorylation. Using optical mapping techniques, we will elucidate whether Wnt signaling dynamically regulates cardiac conduction in the adult heart.

描述（由适用提供）：房屋的室管是胚胎心脏中的重要结构，与瓣膜形成有关，并与电脉冲延迟协调，以确保心房和心室的顺序激活和收缩。在这里，我们试图了解如何通过其对离子通道基因表达和心脏传导的调节来调节心室（AV）连接的电程编程。研究领域很重要，因为先天性和获得性心律不齐，这是发病率和死亡率的重要原因，这可能是由于影响离子通道基因表达和心脏传导的基因表达程序的改变而导致的。胚胎心肌内的规范WNT信号的丧失会导致先天性心脏缺陷影响AV结，包括三尖瓣瓣膜闭合。在这里，我们将调查Wnt信号传导如何调节AV结的形态发展的机制，以及该组织的电代理，以下目的是：1。描述心肌Wnt信号调节心肌室内脑室的机制。使用遗传小鼠模型来执行规范WNT信号的功能丧失和功能丧失，我们将评估WNT在调节AV交界处心外膜和心内膜细胞的增殖，迁移和分化中的作用。我们将阐明是否需要Wnt信号来进行AV结的产后维持，以及Wnt激活是否足以诱导产后心脏的Ecopic AV连接。 2：确定促进房屋连接表型的规范Wnt信号的直接目标。根据我们的初步数据，WNT在全球范围内调节AV结的表型。我们将对β-catenin进行染色质免疫沉淀（CHIP），Wnt信号的关键转录效应子以及增强子诱变评估，以确定Wnt如何调节转录因子TBX3的表达。我们将执行RNA测序和芯片，然后进行大量平行的DNA测序（CHIP-SEQ），以鉴定新型推定的下游Wnt靶基因及其调节元件。 3：阐明WNT介导的心脏传导调节机制。我们的初步数据表明，在开发过程中，Wnt信号的扰动会改变钠通道和间隙连接的AV传导和表达。在功能丧失的小鼠突变体中，我们将使用CHIP-QPCR来确定如何通过Wnt信号调节钠通道表达，我们将确定Wnt突变体小鼠中的心室传导速度的改变是否与NAV1.5和/或GAP连接蛋白表达和磷酸化的变化有关。使用光学映射技术，我们将阐明Wnt信号传导动态调节成人心脏的心脏传导。