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

描述（由申请方提供）：内皮细胞分化和血管身份的建立对于正常和疾病环境中的血管功能至关重要。例如，在发育中的胚胎中，动脉和静脉内皮细胞的分化对于适当的血管模式和循环功能是必不可少的。类似地，许多先天性疾病中血管特性的扰动可导致血管异常，例如动静脉畸形。因此，了解正常内皮分化的分子基础将使我们深入了解病理性血管形成，并促进不同血管类型的工程。虽然控制细胞分化的转录层次结构在其他组织中已被广泛表征，但对内皮细胞中的此类程序知之甚少。本申请中提出的研究将开始解决内皮细胞中在转录水平上对动脉和静脉分化的控制。特别是，我们将确定顺式调节元件在人类基因组中，负责动脉和静脉内皮细胞特异性基因表达。这将通过全基因组鉴定已知可靠标记增强子和阻遏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性基因表达相关的常见顺式调控序列。这些将揭示上游转录调节因子的可能性。为了在功能上验证推定的动脉和静脉顺式元件的活性，我们将使用斑马鱼作为模型系统对人元件进行体内报告基因测定。斑马鱼胚胎的透明性和外部发育，加上其快速发育，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映射有助于动脉和静脉内皮分化和血管身份的转录调控输入。 公共卫生相关性：血管根据其解剖位置具有不同的功能和外观（例如动脉与静脉）。这些差异在早期胚胎中很明显，可能在疾病环境中发挥作用。然而，人们对这些差异是如何产生的知之甚少。在本提案中，我们将重点关注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.