A zebrafish fetal alcohol spectrum disorder model of congenital heart defects

描述（由申请人提供）：胎儿酒精谱系障碍（FASD）出生缺陷包括心脏心房、心室、房室间隔缺陷和圆锥体缺陷。这项工作的长期目标是阐明乙醇诱导心脏缺损，特别是间隔缺损的机制，以及叶酸对这些缺损的保护作用。心脏组织来源于不同的祖先群体：第一心脏区（FHF）和第二心脏区（SHF）。FHF谱系对两个议院都有贡献。SHF祖细胞参与大部分心肌和流出道（OFT）。干扰这些祖细胞群中的任何一个都可能导致腔室和瓣膜的缺陷。这些祖细胞起源于胚胎中胚层的不同位置，受到不同信号分子的调控。特异性心脏转录因子与染色质重塑复合体BAF的相互作用通过调节心脏基因表达来控制心脏发育。从斑马鱼到人类，整个脊椎动物物种的心脏调节网络都是保守的。最初的研究表明，在不同的心源性事件中暴露于乙醇的斑马鱼胚胎会破坏心脏规范、腔室和瓣膜发育的形态发生。叶酸（FA）的补充挽救了乙醇诱导的发育缺陷，包括瓣膜发育缺陷。我们对乙醇对FASD患者心脏调节网络、祖细胞群和瓣膜形态发生机制的影响的了解有很大的差距。我们的总体假设是，乙醇诱导心脏转录因子和BAF染色质重塑复合物组分的表达波动，改变FHF和SHF祖细胞对心脏造成腔室和瓣膜发育缺陷的贡献，而叶酸影响表观遗传过程，将恢复更正常的基因表达水平平衡，恢复更正常的心脏发生。我们的实验计划是解剖斑马鱼FASD模型中心脏缺陷的细胞和分子机制，具体解决PA-12-232中描述的优先事项：干细胞和酒精诱导的组织损伤，其目标是“胎儿酒精综合征”、“心血管疾病”和“改善酒精研究的动物模型”，特别是酒精对特定干细胞/祖细胞的影响。我们为这个项目提出以下具体目标。具体目标研究乙醇对心肌祖细胞调节因子的影响，确定FHF和SHF衍生细胞对乙醇诱导的心脏缺陷的贡献。具体目标2。乙醇诱导房室管和瓣膜发育缺陷的分子和细胞特征。拟议的研究将有助于确定乙醇敏感的形态发生机制，可能有助于FASD患者的心脏缺陷。本项目将解剖乙醇敏感的细胞和分子心脏发生机制，为先天性心脏缺陷的发生和FA的保护作用提供见解。

DESCRIPTION (provided by applicant): Fetal alcohol spectrum disorder (FASD) birth defects include cardiac atrial, ventricular, atrioventricular septal defects, and conotruncal defects. The long-term goal of this work is to elucidate the mechanisms of ethanol induced cardiac defects, particularly septal defects, and folic acid protection of these defects. Cardiac tissues are derive from distinct progenitor populations: first heart field (FHF) and second heart field (SHF). FHF lineage contributes to both chambers. SHF progenitors contribute to most of the myocardium and outflow tract (OFT). Interfering with any of these progenitor populations could cause defects in chambers and valves. These progenitors originate in different locations from the embryonic mesoderm by controlled regulation of different signaling molecules. Interaction between specific cardiac transcription factors and chromatin remodeling complex BAF controls heart development by regulating cardiac gene expression. Cardiac regulatory networks are conserved across vertebrate species, from zebrafish to human. Initial studies showed that zebrafish embryos exposed to ethanol during distinct cardiogenic events disrupt cardiac specification, chamber and valve development morphogenesis. Folic acid (FA) supplementation rescued ethanol induced developmental defects, including valve development defects. There is a significant gap in our knowledge of ethanol effects on cardiac regulatory networks, progenitor populations and valve morphogenesis mechanisms in FASD patients. Our overall hypothesis is that ethanol induces fluctuation in expression of cardiac transcription factors and BAF chromatin remodeling complex components, alters FHF and SHF progenitor contributions to the heart causing chamber and valve development defects, and folic acid, which affects epigenetic processes, will restore a more normal balance of gene expression levels, restoring more normal cardiogenesis. Our experimental plan to dissect the cellular and molecular mechanisms underlying cardiac defects in our zebrafish model of FASD specifically addresses priorities described in PA-12-232: Stem Cells and Alcohol-induced Tissue Injuries, which targets 'fetal alcohol syndrome', 'cardiovascular disease' and 'improving animal models for alcohol research', particularly alcohol effects on specific stem/progenitor cells. We propose the following specific aims for this project. Specific Aim 1. Examine ethanol effects on regulators of myocardial progenitors and determine the contribution of FHF and SHF derived cells to ethanol induced cardiac defects. Specific Aim 2. Molecular and cellular characterization of ethanol induced atrioventricular canal and valve development defects. Proposed studies will help identify ethanol sensitive morphogenesis mechanisms that may contribute to heart defects in FASD patients. This project will dissect ethanol sensitive cellular and molecular cardiogenesis mechanisms, providing insight into congenital heart defect genesis and FA's protective role.