Role of Notch in Artery Development

描述(由申请人提供)：Notch信号通路的组件在胚胎发生过程中对多种细胞类型的发育是必不可少的。此外，Notch信号成分的突变与多种人类疾病有关，包括那些影响心血管功能的疾病。在血管系统中，Notch受体在动脉内皮细胞中特异表达，并在动脉定义中发挥关键作用 身份。在新血管萌发或血管生成过程中，Notch信号对于协调尖端和茎细胞的行为也很重要。我们之前使用斑马鱼作为模型系统的工作有助于确定Notch在动脉分化和血管生成中的作用。重要的是，我们过去和现在的研究表明，这些都是通过不同的受体和配体组合控制的不同过程。此外，Notch在这些过程中的激活是动态的，发生在不同的发育阶段和不同的内皮细胞亚型中。因此，在每一种情况下，很可能都有不同的细胞输出和形态发生反应由Notch控制。然而，在不同的环境中，靶基因是什么来调节Notch的功能还不清楚。为了确定血管系统中的功能Notch靶点，我们提出了两个不同目标的研究。在目标1中，我们将研究斑马鱼动脉内皮细胞中依赖于Notch的候选转录抑制物的需求。这些研究将依赖于应用位点特异性核酸酶来产生缺乏这些基因的敲除斑马鱼品系，然后进行详细的表型和上位性分析。这些研究将利用我们丰富的专业知识，利用斑马鱼进行复杂的遗传分析和高含量的表型分析。在目标2中，我们将确定人动脉内皮细胞中NOTCH1受体的直接靶点，以更好地了解Notch激活如何规划动脉识别。综上所述，这些研究将使我们能够了解Notch如何在不同的环境中影响内皮细胞的行为和分化。

DESCRIPTION (provided by applicant): Components of the Notch signaling pathway are essential for the development of numerous cell types during embryogenesis. Furthermore, mutations in Notch signaling components are associated with a variety of human diseases, including those affecting cardiovascular function. Within the vascular system, Notch receptors are expressed specifically in arterial endothelial cells and play a crucial role in defining artery identity. Notch signaling is also important for coordinating tip and stalk cell behaviors during th sprouting of new blood vessels, or angiogenesis. Our previous work using the zebrafish as a model system was instrumental in defining the roles of Notch during both artery differentiation and angiogenesis. Importantly, our past and current studies suggest that these are distinct processes governed through different receptor and ligand combinations. Additionally, Notch activation during these processes is dynamic, occurring at different developmental stages and in different endothelial subtypes. Thus, it is likely that there are distinct cellular outputs and morphogenetic responses controlled by Notch in each of these contexts. However, what the target genes are to mediate Notch function in different contexts is not known. To identify functional Notch targets in the vascular system, we propose studies encompassed in two separate Aims. In Aim 1, we will investigate the requirements of candidate transcriptional repressors that we have found are dependent on Notch in arterial endothelial cells in zebrafish. These studies will rely on the application of site-specific nucleases to generate knockout zebrafish lines deficient for these genes, followed by detailed phenotypic and epistasis analysis. These studies will leverage our vast expertise using the zebrafish for complex genetic analyses coupled with high content phenotypic analysis. In Aim 2, we will identify direct targets of the NOTCH1 receptor in human arterial endothelial cells to better understand how Notch activation programs artery identity. Taken together, these studies will allow us to understand how Notch may effect endothelial cell behaviors and differentiation in distinct contexts.