Regulation of AV canal formation by the Jak-STAT pathway

描述（由申请人提供）：心血管异常是观察到的最常见的先天性出生缺陷之一。在这些异常中，很大一部分表现为房室（AV）管发育所产生的结构形成的改变。我们已经确定Jak-STAT信号转导通路在调节AV管的形成中起作用。我们的数据表明，Jak-STAT通路的许多成员都定位于AV管，并且通过阻断Jak 3的功能，我们可以抑制正常AV管的形成。该提案旨在通过以下方式深入了解调节AV管中该途径的分子相互作用：（1）确定该途径的哪些STAT成员在AV管中具有活性;以及（2）鉴定该途径的上游激活剂及其在调节AV管形态发生中的作用位点。通过利用三维胶原蛋白凝胶生物测定和最近的基因靶向技术，如反义寡核苷酸，吗啉代，RNAi和功能干扰化学调节剂，以抑制特定的Jak和STAT分子，我们打算测试以下假设：激活的Jak-STAT途径控制适当的AV管的形成，并反映在转化过程的关键标志物的表达。我们的原则将在以下目标中得到检验。 目标1：表征AV管形态发生期间发生的上皮细胞向间充质细胞转化（EMT）中激活的途径的特定STAT成员。目的2：建立Jak-STAT通路在EMT过程调节中发挥作用的精确组织，即心肌或内皮。目的3：确定通过IL-2 R途径发挥作用的Jak 3上游激活因子。

DESCRIPTION (provided by applicant): Cardiovascular anomalies represent one of the most prevalent congenital birth defects observed. Of these anomalies, a significant proportion manifest as an alteration in the formation of structures derived from the development of the atrioventricular (AV) canal. We have identified the Jak-STAT signal transduction pathway as playing a role in regulating the formation of the AV canal. Our data show that numerous members of the Jak-STAT pathway are localized to the AV canal, and that by blocking the function of Jak3 we can inhibit normal AV canal formation. This proposal seeks to gain insight into the molecular interactions that regulate this pathway in the AV canal by: (1) determining which STAT members of the pathway are active in the AV canal; and (2) identifying the upstream activators of the pathway and their site(s) of action in regulating the morphogenesis of the AV canal. By exploiting the use of 3-dimensional collagen gel bioassay and recent gene targeting techniques, such as antisense oligonucleotides, morpholinos, RNAi and function-perturbing chemical modulators, to inhibit specific Jak and STAT molecules we intend to test the following hypothesis: that activation of the Jak-STAT pathway controls proper AV canal formation and is reflected in the expression of key markers of the transformation process. Our tenets will be tested in the following aims. Aim 1: Characterize the specific STAT members of the pathway activated in epithelial to mesenchymal cell transformation (EMT) that occurs during AV canal morphogenesis. Aim 2: Establish the precise tissue in which the Jak-STAT pathway is functioning in regulation of the EMT process, i.e. myocardium or endothelium. Aim3: Identify the upstream activators of Jak3 that function through the IL-2R pathway.