Calcineurin in Congenital Urinary Tract Obstruction

描述(申请人提供)：先天性梗阻性肾病是导致儿童肾功能衰竭的主要原因。然而，导致先天性梗阻的分子和细胞损伤在很大程度上仍未确定。我们已经证明，在我们产生的Pax3Cre Cnb1突变体中，发育中的尿路间充质中缺乏钙调神经磷酸酶，导致人类先天性梗阻性肾病，类似于输尿管肾盂接头(UPJ)梗阻。我们的研究证明了钙调神经磷酸酶在尿路发育中的明确需求，并为进一步研究参与其中的不可或缺的信号事件和先天性梗阻性肾病的病因提供了材料和知识。 我们建议首先研究钙调神经磷酸酶与其他已知参与尿路发育的信号通路之间的相互作用。这将检验钙调神经磷酸酶是尿路发育不可或缺的信号转导的假说。这也将有效地将我们的观察与该领域的现有知识联系起来，并将在分子和细胞水平上为先天性梗阻性肾病的发病机制提供更全面的解释。然后，我们将建立携带Cnb1缺失的原代和永生化细胞系，以确定钙调神经磷酸酶失活对细胞行为和信号的影响，以验证钙调神经磷酸酶是解释尿路细胞中各种细胞外信号所必需的假设。我们还将使用基因组/蛋白质组方法和分子遗传学方法来确定尿路发育中钙调神经磷酸酶下游的因素。此外，我们将补充Pax3Cre-Cnb1研究，在输尿管芽(UB)衍生物中缺失Cnb1，以检验钙调神经磷酸酶在输尿管芽(UB)和尿路发育过程中的上皮-间充质相互作用中具有额外的不可或缺的体内功能的假设。我们将利用这些突变体进一步分析体内相关信号通路的相互作用。拟议的研究结果将为钙调神经磷酸酶在尿路正常和异常发育中的作用以及先天性梗阻性肾病的病因提供机制方面的见解。

DESCRIPTION (provided by applicant): Congenital obstructive nephropathy is the principal cause of pediatric renal failure. The molecular and cellular lesions leading to congenital obstruction, however, are still largely undetermined. We have shown that the absence of calcineurin in the developing urinary tract mesenchyme, in the Pax3Cre Cnb1 mutants we generated, led to congenital obstructive nephropathy resembling Ureteropelvic Junction (UPJ) obstruction in humans. Our study has demonstrated a clear requirement for calcineurin in urinary tract development and provided us with materials and knowledge to further investigate the indispensable signaling events involved and the etiology of congenital obstructive nephropathy. We propose to first study the interactions between calcineurin and other signaling pathways known to be involved in urinary tract development. This will test the hypothesis that calcineurin is an indispensable signaling transducer for urinary tract development. This will also effectively connect our observations to the existing knowledge in this field and will provide a more comprehensive explanation, at the molecular and cellular level, for the pathogenesis of the congenital obstructive nephropathy. Then, we will develop primary and immortalized cell lines carrying the Cnb1 deletion to determine the effects of calcineurin inactivation in cellular behavior and signaling to test the hypothesis that calcineurin is required for interpreting various extracellular signals in cells of the urinary tract. We will also use genomic/proteomic approaches and molecular genetic methods to identify factors downstream of calcineurin in urinary tract development. Furthermore, we will complement the Pax3Cre-Cnb1 study with Cnb1 deletion in the ureteric bud (UB) derivatives to test the hypothesis that calcineurin has additional indispensable in vivo function in the UB and in the epithelial-mesenchymal interactions during urinary tract development. We will use these mutants to further analyze the interactions of the relevant signaling pathways in vivo. Results from the proposed studies will provide mechanistic insights into the function of calcineurin in normal and abnormal development of the urinary tract and the etiology of congenital obstructive nephropathy.