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普遍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）管发育引起的结构形成的改变。我们已经确定了Jak-STAT信号转导通路在调节房室管的形成中起作用。我们的数据表明，Jak3 - stat通路的许多成员都定位于房室管，通过阻断Jak3的功能，我们可以抑制正常的房室管形成。本研究旨在通过以下途径深入了解调节该通路的分子相互作用：(1)确定该通路的哪些STAT成员在房室管中活跃；(2)识别该通路的上游激活因子及其在调节房室管形态发生中的作用位点。通过利用三维胶原凝胶生物测定和最近的基因靶向技术，如反义寡核苷酸、morpholinos、RNAi和功能干扰化学调节剂，来抑制特定的Jak和STAT分子，我们打算测试以下假设：Jak-STAT途径的激活控制着适当的AV管形成，并反映在转化过程的关键标记物的表达中。我们的信条将在以下目标中得到检验。目的1：描述在房室管形态发生过程中上皮细胞向间充质细胞转化（EMT）中激活的通路的特定STAT成员。目的2：确定Jak-STAT通路调控EMT过程的精确组织，即心肌或内皮细胞。目的3：鉴定通过IL-2R通路起作用的Jak3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.