Identification of artery- and vein-specific cis elements in the human genome

描述(由申请人提供)：内皮细胞分化和血管身份的建立对于正常和疾病环境下的血管功能都是必不可少的。例如，在发育中的胚胎中，动脉和静脉内皮细胞的分化对于正确的血管构型和循环功能至关重要。同样，在一些先天性疾病中，血管特性的扰动可能会导致血管异常，如动静脉畸形。因此，了解正常内皮细胞分化的分子基础将有助于我们深入了解病理性血管的形成，并有助于构建不同类型的血管。虽然控制细胞分化的转录层次在其他组织中得到了广泛的表征，但对内皮细胞中的此类程序知之甚少。在这项申请中提出的研究将开始在转录水平上解决内皮细胞对动脉和静脉分化的控制。特别是，我们将确定人类基因组中负责动脉和静脉内皮细胞特异性基因表达的顺式调控元件。这将通过在全基因组范围内识别已知可可靠标记增强子和抑制子元件的一般转录调节蛋白的结合位点来实现。随后的计算分析将使我们能够识别与动脉或静脉特异基因表达相关的常见顺式调控序列。这些可能会让人们对上游转录调控机制有更深入的了解。为了从功能上验证可能的动脉和静脉顺式元件的活性，我们将以斑马鱼为模型系统，对人类元件进行体内报告分析。斑马鱼胚胎的透明度和外部发育，加上它的快速发展，将使我们能够全面确定众多动脉和静脉限制性基因的大量顺式元件的活性。总之，这些研究将使我们能够绘制有助于动脉和静脉内皮细胞分化和血管识别的转录调控输入。 公共卫生相关性：血管根据其解剖位置的不同有不同的功能和外观(例如，动脉和静脉)。这些差异在早期胚胎中很明显，并可能在疾病背景下发挥作用。然而，人们对这些差异是如何产生的知之甚少。在这项提案中，我们将重点揭示支配动脉和静脉身份的信号。

DESCRIPTION (provided by applicant): Endothelial cell differentiation and establishment of blood vessel identity is essential for vascular function in both normal and disease settings. For example, in the developing embryo differentiation of arterial and venous endothelial cells is essential for proper vessel patterning and circulatory function. Similarly, perturbation of blood vessel identity in a number of congenital diseases can lead to vascular anomalies, such as arteriovenous malformations. Thus, understanding the molecular basis of normal endothelial differentiation would give us insights onto pathological blood vessel formation and facilitate the engineering of distinct blood vessel types. While transcriptional hierarchies controlling cellular differentiation have been extensively characterized in other tissues, much less is known about such programs in endothelial cells. The studies proposed in this application will begin to address the control of artery and vein differentiation at the transcriptional level in endothelial cells. In particular, we will identify cis regulatory elements in the human genome that are responsible for arterial and venous endothelial-specific gene expression. This will be accomplished through the genome-wide identification of binding sites for general transcriptional regulatory proteins known to reliably mark enhancer and repressor elements. Subsequent computational analyses will allow us to identify common cis regulatory sequences that correlate with artery or vein specific gene expression. These will shed possible insight onto upstream transcriptional regulators. To functionally validate the activity of putative artery and vein cis elements, we will perform in vivo reporter assays on human elements using the zebra fish as a model system. The transparency and external development of the zebra fish embryo, coupled with its rapid development will allow us to comprehensively determine the activity of a large number of cis elements for numerous arteries and vein restricted genes. Together, these studies will allow us to map the transcriptional regulatory inputs that contribute to arterial and venous endothelial differentiation and blood vessel identity. PUBLIC HEALTH RELEVANCE: Blood vessels have different functions and appearances (e.g. artery versus vein) depending on their anatomical location. These differences are apparent in early embryos and may play a role in disease settings. However, little is known about how these differences arise. In this proposal, we will focus on uncovering the signals that govern artery and vein identity.