sox9b function in cardiomyocyte and great vessel development

项目摘要/摘要 先天性心脏和大血管异常是婴儿死亡和发病的主要原因。 然而，在美国，大多数先天缺陷的病因仍不清楚。约90%的 先天性心脏和血管缺陷的病例是多因素的。人们认为暴露在环境污染物中 对缺陷以及成人心脏病的发病率有显著影响。我们的长期目标是 通过详细了解基因的功能来预防和治疗先天性缺陷和成人心脏病 它们对心血管发育至关重要，也会受到环境毒物的干扰。我们 已经确定了一个候选基因SOX9，它在发育和成熟的多种细胞类型中都有表达 在暴露于空气中的环境毒物的动物模型中，心脏和心脏的表达下调 污染、电子垃圾、塑料和杀虫剂。人类SOX9编码区突变导致坎皮病 发育不良(CD)，一种严重的遗传性疾病，通常会导致死亡。几种不同的先天性心脏病 CD患者和突变个体都有大血管缺陷的报道。 影响SOX9功能。总而言之，人类功能数据的丧失表明SOX9发挥着几个关键的作用 在心脏和大血管发育中的作用。然而，Sox9b/Sox9在心肌细胞中起着重要的作用 还没有使用动物模型来研究血管的发育。我们的初步数据显示 斑马鱼Sox9b对心肌细胞的发育和功能以及大血管的形成都是必不可少的。 我们的近期目标是确定调节心脏和大血管的分子机制。 斑马鱼Sox9b功能丧失后观察的表型并确定Sox9b功能是否 由哺乳动物Sox9保存。我们正在使用一种创新的多物种方法和 在心血管发育过程中操纵斑马鱼Soxb和小鼠Sox9的基因工具。在Aim 1.1中， 我们将确定Sox9b是否是发育中的斑马鱼心脏中典型的WNT信号的抑制剂。在AIM 1.2，我们将抑制胚胎心肌细胞中的Sox9b功能，并使用RNAseq识别其他 Sox9b在斑马鱼心脏发育过程中的分子靶点。在目标2中，我们使用特定于细胞类型的 确定Sox9b功能丧失如何导致大血管表型的操作和光遗传学 并确定SOX9B、NKX2.5和STAT4这两个已知的大血管介体之间的关系 发展。在目标3中，我们将通过以下方式扩展我们对Sox9b在心脏发育中的功能的理解 检测小鼠心肌细胞和内皮细胞中Sox9的缺失对心脏和大血管的影响 以及小鼠心脏中Sox9的缺失如何影响典型的WNT信号转导。一起， 这些研究将有助于我们了解Sox9b/Sox9的内源功能以及遗传和/或 SOX9功能的环境破坏可导致先天性心脏病和大血管缺陷 人类。

PROJECT SUMMARY/ABSTRACT Congenital abnormalities of the heart and great vessels are the leading cause of infant mortality and morbidity in the United States yet the etiology of most congenital defects remains unknown. Approximately 90% of congenital heart and vessel defect cases are multifactorial. Exposure to environmental contaminants is thought to significantly contribute to the incidence of defects as well adult heart disease. Our long-term goal is to prevent and treat congenital defects and adult heart disease by understanding, in detail, the functions of genes that are critical for cardiovascular development and also disrupted by exposure to environmental toxicants. We have identified a candidate gene, SOX9, that is expressed in multiple cell types in the developing and mature heart and is downregulated in animal models following exposure to environmental toxicants present in air pollution, e-waste, plastics, and pesticides. Human mutations in the SOX9 coding region result in Campomelic Dysplasia (CD), a severe genetic disorder that usually results in death. A number of different congenital heart and great vessel defects have been reported in patients with CD as well as in individuals with mutations affecting SOX9 function. Together, the human loss of function data suggests that SOX9 plays several critical roles in cardiac and great vessel development. However, Sox9b/Sox9 functions in cardiomyocyte and great vessel development have not been investigated using animal models. Our preliminary data indicate that zebrafish Sox9b is essential for cardiomyocyte development and function as well as great vessel formation. Our immediate goal is to identify the molecular mechanisms that mediate the cardiac and great vessel phenotypes observed following loss of Sox9b function in zebrafish and to determine if Sox9b functions are conserved by mammalian Sox9. We are using an innovative multi-species approach and a combination of genetic tools to manipulate zebrafish Soxb and murine Sox9 during cardiovascular development. In Aim 1.1, we will determine if Sox9b is an inhibitor of canonical WNT signaling in the developing zebrafish heart. In Aim 1.2, we will inhibit Sox9b function in embryonic cardiomyocytes and use RNAseq to identify additional molecular targets of Sox9b during zebrafish heart development. In Aim 2, we use the cell-type specific manipulations and optogenetics to determine how loss of Sox9b function leads to the great vessel phenotypes and to determine the relationship between Sox9b, Nkx2.5, and Stat4, two known mediators of great vessel development. In Aim 3, we will extend our understanding of Sox9b function in cardiac development by examining how loss of Sox9 in mouse cardiomyocytes and endothelial cells affects cardiac and great vessel development as well as how loss of Sox9 in the murine heart impacts canonical WNT signaling. Together, these studies will help us understand the endogenous functions of Sox9b/Sox9 and how genetic and/or environmental disruptions in SOX9 function can contribute to congenital heart and great vessel defects in humans.