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

项目摘要 内皮细胞的分化和血管特性的建立对于血管生成是至关重要的。 在正常和疾病环境中发挥作用。例如，在发育中的胚胎分化 动脉和静脉内皮细胞的增殖对于适当的血管模式和循环至关重要。 功能类似地，在许多先天性疾病中血管特性的扰动可导致 血管异常，如动静脉畸形。因此，了解分子 正常内皮细胞分化的基础将使我们了解病理性血管 形成并促进不同血管类型的工程化。虽然转录 控制细胞分化的层次结构在其它组织中已被广泛表征， 关于内皮细胞中的这些程序知之甚少。本报告中提出的研究 应用将开始解决在转录水平上控制动脉和静脉分化 在内皮细胞中。特别是，我们将确定人类基因组中的顺式调控元件， 负责动脉和静脉内皮特异性基因表达。这将是 通过在全基因组范围内识别用于一般转录的结合位点来完成， 已知可靠地标记增强子和阻遏子元件的调节蛋白。后续 计算分析将使我们能够识别与以下相关的共同顺式调节序列： 动脉或静脉特异性基因表达。这些将为上游提供可能的洞察力 转录调节因子。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类元件进行体内报告基因测定。 斑马鱼胚胎的透明度和外部发育，加上其快速的 发展将使我们能够全面确定大量独联体成员的活动， 许多动脉和静脉限制基因。总之，这些研究将使我们能够绘制 有助于动脉和静脉内皮分化的转录调控输入， 血管身份

PROJECT SUMMARY 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 zebrafish as a model system. The transparency and external development of the zebrafish embryo, coupled with its rapid development will allow us to comprehensively determine the activity of a large number of cis elements for numerous artery 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.