Embryonic origins of endothelial heterogeneity

项目总结 内皮细胞的异质性是成熟循环系统的一个重要特征。内皮细胞 排列在毛细血管床或其他小口径血管中的细胞有不同的表型和分子 与它们在不同解剖位置的不同功能有关的签名。在更大的船只上， 动脉内皮细胞和静脉内皮细胞之间存在明显的分子和表型差异。 在所有这些情况下，内皮分化对于血管的正常生理功能是必不可少的。 循环系统。重要的是，内皮细胞的异质性可以对部位和 血管疾病的严重程度。因此，更好地了解内皮细胞类型是如何 决心是高度相关的。在过去的15年里，我们一直使用斑马鱼作为模型系统 探讨胚胎血管形态发生和图案化的基本机制 发展。我们的努力揭示了血管是如何形成的，以及 强调内皮细胞分化在这一过程中的重要性。重要的是，我们发现 内皮细胞分化是血管形成所必需的主要步骤， 集合。然而，内皮细胞特性和信号通路的发育起源 这种驱动差异的因素在很大程度上是未知的。在这里提出的研究中，我们将应用一些 传统的发育生物学方法与尖端的分子技术相结合 定义胚胎发育过程中内皮细胞个体发育的等级。通过CRE/LOX血统 追踪我们将确定何时何地建立内皮细胞类型。同时，我们将 对多个发育阶段的内皮祖细胞进行单细胞RNA测序 确定定义内皮细胞亚型的转录组特征。与此同时，努力确定 亚型特异性基因两侧的增强子元件将有助于我们了解转录 驱动分化的调控途径和上游信号。最后，我们将继续 研究内皮分化与血管形态发生之间的联系 利用基因组产生的斑马鱼基因敲除模型查询亚型特异性基因 正在编辑。我们的共同努力将定义发育中的内皮层级，并使我们能够 确定导致内皮细胞异质性的基本信号通路。

PROJECT SUMMARY Endothelial heterogeneity is a defining characteristic of the mature circulatory system. Endothelial cells that line capillary beds or other small caliber vessels have distinct phenotypes and molecular signatures that relate to their various functions in different anatomical locations. In larger vessels, there are clear molecular and phenotypic differences between arterial and venous endothelial cells. In all of these cases, endothelial differentiation is essential for normal physiological function of the circulatory system. Importantly, endothelial heterogeneity can have a major influence on the site and severity of vascular disease. Thus, a better understanding of how endothelial cell types are determined is highly relevant. For the past 15 years, we have used the zebrafish as a model system to investigate basic mechanisms of vascular morphogenesis and patterning during embryonic development. Our efforts have revealed new insights into how blood vessels are formed and underscore the importance of endothelial differentiation in this process. Importantly, we have found that endothelial cell differentiation is a primary step that is essential for blood vessel formation and assembly. However, the developmental origins of endothelial identities and the signaling pathways that drive differentiation are largely unknown. In the studies proposed here, we will apply a number of traditional developmental biology approaches coupled with cutting-edge molecular techniques to define the hierarchy of endothelial ontogeny during embryonic development. Through Cre/lox lineage tracing we will identify where and when endothelial cell types are established. In parallel, we will apply single cell RNA sequencing on endothelial progenitors at multiple developmental stages to identify transcriptome signatures that define endothelial subtypes. At the same time, efforts to identify enhancer elements flanking subtype-specific genes will contribute to our knowledge of transcriptional regulatory pathways and upstream signals that drive differentiation. Finally, we will continue to investigate the link between endothelial differentiation and vascular morphogenesis through functional interrogation of subtype specific genes using knockout zebrafish models generated through genome editing. Together, our efforts will define the developmental endothelial hierarchy and allow us to identify essential signaling pathways responsible for endothelial heterogeneity.