Exploring the Role of the anterior SHF in AVSD Pathogenesis

探索前 SHF 在 AVSD 发病机制中的作用

基本信息

批准号：
10854097
负责人：
Arno Wessels
金额：
$ 24.55万
依托单位：
MEDICAL UNIVERSITY OF SOUTH CAROLINA
依托单位国家：
美国
项目类别：
财政年份：
2023
资助国家：
美国
起止时间：
2023-09-01 至 2024-04-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10854097
关键词：
Administrative Supplement Animal Model Anterior Atrial Heart Septal Defects Candidate Disease Gene Cardiac Cause of Death Cells Chromosome 16 Chromosome 21 Complex Congenital Abnormality Congenital Heart Defects Defect Development Diagnosis Dorsal Down Syndrome Down-Regulation Embryo Endocardium Engineering Event Funding General Population Genes Genetic Health Heart Heart Abnormalities Heart Atrium Human Chromosomes Individual Investigation Life Longevity Mesenchymal Modeling Modification Molecular Morphology Mus National Heart, Lung, and Blood Institute Pathogenesis Patients Phenotype Play Publishing Research Role Specimen Structural defect Structure Testing Ventricular Ventricular Septal Defects atrioventricular septal defect cardiogenesis congenital heart disorder experimental study insight interest migration mouse Trisomy 16 mouse model offspring prevent response single-cell RNA sequencing theories virtual

项目摘要

This application for an Administrative Supplement to our active R01-HL122906 is being submitted in response to PA-20-272 in accordance with NOT-OD-22-137 (“Availability of Administrative Supplements for the INCLUDE - INvestigation of Co-occurring conditions across the Lifespan to Understand Down syndrome - Project”). Significance of application in relation to Down syndrome (DS): Atrioventricular septal defects (AVSDs) are complex congenital heart defects but relatively rare in the general population. Approximately 0.05% of babies born have an AVSD. They are, however, very common in DS patients (35-40% of DS babies are diagnosed with an AVSD). In this project we will address one of the priorities of the National Heart, Lung, and Blood Institute (NHLBI) as we will, using animal models, focus on the morphological events involved in the pathogenesis of AVSDs which, if untreated, can be the cause of death during the first year of life. Abstract: The study of heart development as it relates to congenital heart disease has been the focus of the Wessels lab for years. This proposal is a logical extension of studies that were initiated after the discovery of the Dorsal Mesenchymal Protrusion (DMP) by the PI. We identified the DMP as a structure critically important for the development of the atrioventricular (AV) mesenchymal complex and determined that the DMP was derived from the Second Heart Field (SHF). We developed the hypothesis that the DMP could be involved in the pathogenesis of AVSDs. Indeed, in our study of the Trisomy 16 (Ts16) mouse, a model for DS, we found that AVSDs were associated with hypoplasia of the DMP. Furthermore, we demonstrated that experimentally deleting candidate genes believed to be essential for proper SHF development (Alk3 and Smo) resulted in perturbation of DMP formation and AVSD pathogenesis. Analysis of the SHF;Smo mouse revealed downregulation of several genes including Sox9. Based on our earlier studies, we predicted that Sox9 would play a critical role in DMP development and AV septation. Surprisingly, while SHF-specific Sox9 deletion resulted in AVSD in 50% of SHF;Sox9 offspring, it was not the result of DMP hypoplasia, but rather associated with failed development of the mesenchymal cap. Importantly, virtually all specimens inspected had developed a ventricular septal defect (VSD). This (published) observation in combination with results of our studies on AVSD pathogenesis (see: Research Plan) have led to new theories about the role of the anterior and posterior SHF (aSHF and pSHF) in the pathogenesis of the atrial and ventricular defects in the context of DS. We propose experiments with different mouse models, including the TcMAC21 model for DS, to test these hypotheses. In addition, we will initiate single cell RNAseq experiments to gain insight into the molecular mechanisms involved in the pathogenesis of AVSDs, specifically focusing on the role of the embryonic outflow tract in VSD pathogenesis.

我们正在提交的 R01-HL122906 行政补充申请已于根据 NOT-OD-22-137（“行政补充的可用性”）对 PA-20-272 的答复包括 - 研究整个生命周期中同时发生的病症以了解唐氏综合症 - 项目”）。与唐氏综合症 (DS) 相关的应用意义：房室间隔缺损 (AVSD) 是复杂的先天性心脏缺陷，但在普通人群中相对罕见，大约占婴儿的 0.05%。然而，它们在 DS 患者中非常常见（35-40% 的 DS 婴儿被诊断患有 AVSD）。 AVSD）。在这个项目中，我们将解决国家心脏、肺和血液的优先事项之一。研究所（NHLBI），我们将使用动物模型，重点研究涉及的形态学事件 AVSD 的发病机制，如果不及时治疗，可能会导致出生后第一年的死亡。摘要：心脏发育与先天性心脏病的关系研究一直是国内外研究的热点。韦塞尔实验室多年来的这一提议是对发现该物质后发起的研究的合理延伸。 PI 的背侧间充质突出 (DMP) 我们认为 DMP 是一种对于 DMP 至关重要的结构。房室 (AV) 间充质复合体的发育并确定 DMP 的来源我们提出了 DMP 可能参与第二心脏领域 (SHF) 的假设。事实上，在我们对 16 三体 (Ts16) 小鼠（DS 模型）的研究中，我们发现： AVSD 与 DMP 发育不全有关，此外，我们通过实验证明了删除。被认为对 SHF 正常发育至关重要的候选基因（Alk3 和 Smo）导致扰动 DMP 形成和 AVSD 发病机制的分析；Smo 小鼠揭示了几种下调。基于我们早期的研究，我们预测 Sox9 将在 DMP 中发挥关键作用。令人惊讶的是，SHF 特异性 Sox9 缺失导致 50% 的 AVSD。 SHF;Sox9后代，这不是DMP发育不全的结果，而是与发育失败有关重要的是，几乎所有检查的标本都出现了室间隔缺损。（VSD）。该（已发表）观察结果与我们对 AVSD 发病机制的研究结果相结合（参见：研究计划）提出了关于前部和后部 SHF（aSHF 和 pSHF）在疾病中的作用的新理论。 DS 背景下心房和心室缺陷的发病机制我们提出了不同的实验。此外，我们将启动单个小鼠模型，包括 DS 的 TcMAC21 模型来测试这些假设。细胞 RNAseq 实验可深入了解 AVSD 发病机制所涉及的分子机制，特别关注胚胎流出道在 VSD 发病机制中的作用。