Molecular and cellular mechanisms in cardiac outflow tract formation and defects

心脏流出道形成和缺陷的分子和细胞机制

基本信息

批准号：
10289982
负责人：
BERNICE E MORROW
金额：
$ 66.36万
依托单位：
ALBERT EINSTEIN COLLEGE OF MEDICINE
依托单位国家：
美国
项目类别：
财政年份：
2021
资助国家：
美国
起止时间：
2021-09-01 至 2025-08-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10289982
关键词：
22q11 22q11.2 3-Dimensional Affect Biological Assay Cardiac Cell Communication Cell Lineage Cells Clinical Code Defect Development Developmental Biology DiGeorge Syndrome Disease Distal Embryo Endocardium Endothelin-1 Ensure Genes Genetic Heart Heart Septum Histology Human Immunofluorescence Immunologic In Situ Hybridization Intervention Knowledge Live Birth Medical Mesenchymal Modeling Molecular Morphogenesis Mus Mutation NOTCH1 gene Neural Crest Neural Crest Cell Neural tube Neurophysiology - biologic function Newborn Infant Outcome Patients Pattern Persistent Truncus Arteriosus Phenotype Population Positioning Attribute Prevalence Process Proteins Pulmonary Circulation Research Project Grants Role Signal Transduction Structural defect Structure Syndrome Testing Tetralogy of Fallot Tissues Validation Ventricular Septal Defects Ventricular septum base bicuspid aortic valve cardiogenesis congenital heart disorder connective tissue growth factor experimental study genetic signature genetic variant in vivo malformation mouse model mutant programs reconstruction restoration semilunar valve single-cell RNA sequencing stem cell function stem cells

项目摘要

Project Summary Cardiac outflow tract (OFT) defects have an estimated prevalence of 1-2 in 1,000 live births. The 22q11.2 deletion syndrome or 22q11.2DS is one of the most frequent genetic causes of cardiac OFT defects. A total of 60% of patients with 22q11.2DS have congenital heart disease that ranges from mild to severe including bicuspid aortic valve (BAV), isolated ventricular septal defects (VSDs) to tetralogy of Fallot (TOF) or persistent truncus arteriosus (PTA). These clinical findings suggest genetic modifiers may affect phenotypic expression . In this project, we propose to use the Lgdel/+ mouse model to understand the relationship between neural crest cells (NCCs) and adjacent endocardial cells (ECCs) in forming and remodeling of the cardiac OFT. Mesenchymal cells (MCs) derived from NCCs and ECCs occupy the distal and proximal OFT, respectively, and form a distinct OFT MC boundary during heart development. Proper deployment of MCs from the two lineages ensures correct position and formation of aorto-pulmonary-ventricular septum and semilunar valves to separate the heart outlet into the systemic and pulmonary circulation. The function of NCCs in OFT defects has been well studied with respect to 22q11.2DS, however, the role of ECCs in OFT malformations has not been investigated. We have begun to fill this knowledge gap by studying the Lgdel/+ mouse, which was generated by deleting one copy of the mouse syntenic region of human 22q11.2 containing 26 protein-coding genes (22q11.2DS genes). We found a spectrum of OFT defects ranging from isolated VSD to TOF. The structural defects are preceded by a disrupted OFT MC boundary, increased expression of Edn1 during endocardial-to-mesenchymal transformation (EMT), and decreased NOTCH1 signaling and Ctgf expression during post-EMT OFT remodeling. By single cell RNA sequencing (scRNA-seq), we identified Edn1 as part of a unique gene program operating in a subset of ECCs undergoing EMT. Based on these findings, we propose an overall hypothesis that 22q11.2DS genes control OFT development by regulating the function of ECCs and the cell-cell communications between MCs from ECC and NCC origins, via interacting with genes essential for OFT formation. We will test this hypothesis in three specific aims. Aim 1 will determine whether the 22q11.2DS genes regulate EMT through modulating the EMT gene program, and if Edn1 acts downstream of 22q11.2DS genes to regulate the process. Aim 2 will ascertain whether 22q11.2DS genes also regulate OFT remodeling through a cell-cell interaction network that patterns the OFT MC boundary, and if Ctgf functions as a hub gene required for the post-EMT OFT remodeling, downstream of 22q11.2DS genes. Aim 3 will define whether Notch1 haploinsufficiency can potentiate the 22q11.2DS OFT defects. At the completion of this study, we expect discoveries that will establish genetic, molecular, and cell crosstalk regulated by important syndromic and non-syndromic CHD genes essential for mouse OFT morphogenesis. The information will provide deeper understanding of heart developmental biology and inform the disease mechanism of OFT defects, with a broader implication in congenital heart disease.

项目概要据估计，每 1,000 名活产婴儿中就有 1-2 人患有心脏流出道 (OFT) 缺陷。这 22q11.2 缺失综合征或 22q11.2DS 是心脏 OFT 缺陷最常见的遗传原因之一。一个总共 60% 的 22q11.2DS 患者患有从轻度到重度的先天性心脏病，包括二叶式主动脉瓣 (BAV)、孤立性室间隔缺损 (VSD) 至法洛四联症 (TOF) 或持续性动脉干（PTA）。这些临床发现表明遗传修饰剂可能影响表型表达。在在这个项目中，我们建议使用Lgdel/+小鼠模型来理解神经嵴之间的关系细胞（NCC）和邻近的心内膜细胞（ECC）在心脏 OFT 的形成和重塑中的作用。来自NCC和ECC的间充质细胞（MC）分别占据远端和近端OFT，并且在心脏发育过程中形成明显的 OFT MC 边界。正确调配两个血统的MC 确保主动脉-肺-心室间隔和半月瓣的正确位置和形成以分离心脏出口进入体循环和肺循环。 NCC在OFT缺陷中的作用已得到很好的证实对 22q11.2DS 进行了研究，然而，ECC 在 OFT 畸形中的作用尚未得到研究。我们已经开始通过研究 Lgdel/+ 鼠标来填补这一知识空白，该鼠标是通过删除一个鼠标而生成的人类 22q11.2 的小鼠同线区域的副本，包含 26 个蛋白质编码基因（22q11.2DS 基因）。我们发现了一系列 OFT 缺陷，从孤立的 VSD 到 TOF。结构缺陷先于 OFT MC 边界破坏，心内膜到间质过程中 Edn1 表达增加转化（EMT），并在 EMT 后 OFT 重塑过程中减少 NOTCH1 信号传导和 Ctgf 表达。通过单细胞 RNA 测序 (scRNA-seq)，我们确定 Edn1 是在正在进行 EMT 的 ECC 的子集。基于这些发现，我们提出一个总体假设：22q11.2DS 基因通过调节 ECC 的功能和细胞间的通讯来控制 OFT 的发育来自 ECC 和 NCC 起源的 MC，通过与 OFT 形成所必需的基因相互作用。我们将测试这个三个具体目标的假设。目标 1 将确定 22q11.2DS 基因是否通过调节 EMT 基因程序，以及 Edn1 是否作用于 22q11.2DS 基因下游来调节该过程。目标 2 将确定 22q11.2DS 基因是否也通过细胞间相互作用调节 OFT 重塑形成 OFT MC 边界的网络，以及 Ctgf 是否充当 EMT 后 OFT 所需的中心基因重塑，22q11.2DS 基因下游。目标 3 将定义 Notch1 单倍体不足是否可以增强 22q11.2DS OFT 缺陷。在这项研究完成后，我们预计会有以下发现：受重要的综合征性和非综合征性 CHD 基因调节的遗传、分子和细胞串扰用于小鼠 OFT 形态发生。这些信息将有助于更深入地了解心脏发育生物学并揭示 OFT 缺陷的疾病机制，对先天性心脏病具有更广泛的影响疾病。