Coordination of pulmonary vascular development by Prx1

描述（由申请人提供）：同源异型盒基因编码控制组织模式和形态发生的转录因子，但其在肺血管发育中的作用仍不清楚。我们的初步研究表明，配对相关的同源异型盒基因，Prxl，是所需的肺血管化通过其能力，促进内皮细胞（EC）分化和血管网络的形成。该提议的具体目的如下：（1）定义Prxl如何在肺血管发生期间驱动EC分化：Tie-GFP转基因小鼠将用于在整个肺发育中定位表达Prxl的EC，并且染色质免疫沉淀测定将用于鉴定Prxl在分化的肺EC中的直接靶标。将使用Prxl缺失小鼠和肺EC分化的组织培养模型来评估Prxl及其靶标的有效性和功能;（2）为了确定细胞外基质蛋白生腱蛋白- C（TN-C）的Prxl依赖性诱导如何促进肺血管网络形成：使用胎儿肺移植物的敲除研究，酵母双杂交分析和组织重组将用于了解TN-C如何促进Prxl依赖性网络形成;（3）阐明黏着斑激酶（FAK）在血管网形成过程中对Prxl的调控作用：利用腺病毒介导的FAK活性抑制和Prxl基因启动子的分离来研究FAK对Prxl转录和肺血管形态发生的调控作用。 总体而言，该提案将导致详细了解Prxl在整个胎儿肺血管化中的作用。这项研究将提供肺血管生物学的新概念，并有望产生新的诊断工具和治疗新生儿和成人疾病，其中肺血管受损，如。支气管肺发育不良和肺动脉高压。

DESCRIPTION (provided by applicant): Homeobox genes encode transcription factors that control tissue patterning and morphogenesis, yet their role in pulmonary vascular development remains obscure. Our preliminary studies indicate that the paired related homeobox gene, Prxl, is required for lung vascularization via its ability to promote both endothelial cell (EC) differentiation and vascular network formation. The Specific Aims of this proposal are as follows: (1) To define how Prxl drives EC differentiation during lung vasculogenesis: Tie-GFP transgenic mice will be used to locate Prxl-expressing ECs throughout lung development, and chromatin immunoprecipitation assays will be used to identify direct targets for Prxl in differentiating lung ECs. The validity and functions of Prxl and its targets will be evaluated using Prxl-null mice and tissue culture models of pulmonary EC differentiation; (2) To determine how Prxl-dependent induction of the extracellular matrix protein tenascin- C (TN-C) promotes lung vascular network formation: Knockout studies using fetal lung explants, yeast 2- hybrid assays and tissue recombinations will be used to understand how TN-C promotes Prxl-dependent network formation; (3) To delineate how focal adhesion kinase (FAK) controls Prxl during vascular network formation: Adenoviral-based inhibition of FAK activity, and dissection of the Prxl gene promoter will be used to comprehend how FAK controls Prxl transcription and vascular morphogenesis in the lung. Overall, this proposal will result in a detailed understanding of the role of Prxl throughout fetal lung vascularization. This study should provide new concepts in lung vascular biology, and will hopefully result in novel diagnostic tools and therapies for the treatment of newborn and adult diseases in which the pulmonary vasculature is compromised, eg. bronchopulmonary dysplasia and pulmonary hypertension.