The Role of Basa Bodies in Wnt Signaling

描述(由申请人提供)：肾囊肿的形成是终末期肾功能衰竭的主要原因，鉴于这种疾病的治疗选择有限，了解其细胞基础是至关重要的。来自综合征和非综合征形式的囊性形成的数据，如多囊肾病(PKD)、肾单位(NPH)和Bardet-Biedl综合征(BBS)，已经产生了重要的见解，并为新的治疗方法提供了潜力。在体外和体内的研究表明，肾感觉纤毛的主要作用，并假设这些结构感觉细胞外液体信号已获得显着势头。然而，细胞外信号的性质和作用(S)仍然存在。最近的证据表明纤毛和基底体负责传递形态发生信号。与这一观点一致，我们的初步数据表明，基底的破坏影响了Wnt信号的传播，并且这种突变与非规范(β-连环蛋白非依赖)Wnt信号通路的成员在基因上相互作用。在这里，我们建议研究肾囊性疾病和Wnt信号之间的联系。首先，我们将建立专门针对Bbs1、Bbs4和Bbs6的去势小鼠的肾脏表型，所有这些都与纤毛/基础身体功能有关，并通过LacZ报告程序监测肾脏发育过程中β-连环素的活性。同时，为了探索基底在常见肾脏疾病中的潜在作用，我们将通过在BBS突变系中引入杂合的PKD1或Pkhd1零等位基因来探索BBS和PKD之间可能的协同作用，并确定是否存在遗传交互作用。其次，我们将研究Wnt缺陷在基底突变体和抑制剂中的生化性质，并确定一系列Wnt反应蛋白的行为和细胞分布，如b-catenin和disheveled。最后，我们将结合强大的体外WNT反应分析的能力与最近的研究，大量丰富的新的纤毛和基体蛋白，以确定纤毛的新成分，调节细胞内的WNT反应。通过Wnt信号建立基底和纤毛之间的联系代表了肾囊性疾病的潜在范式转变，并可能导致一种深刻的新的治疗和预防手段。

DESCRIPTION (provided by applicant): The formation of renal cysts is a leading cause of end-stage renal failure, and given the limited management options for this disorder, understanding its cellular basis is of paramount importance. Data from syndromic and non-syndromic forms of cyst formation, such as the polycystic kidney diseases (PKD), nephronophthisis (NPH) and Bardet-Biedl syndrome (BBS), have yielded important insights and hold the potential for new therapeutic approaches. In vitro and in vivo studies have indicated a major role for renal sensory cilia and the hypothesis that these structures sense extracellular fluid signaling has gained significant momentum. However, the nature and effect of the extracellular signal(s) remains. Recent evidence suggests that the cilium and basal body are responsible for transducing morphogenetic signals. In agreement with this notion, our preliminary data suggest that disruption of the basal body affects the propagation of Wnt signaling and that such mutations interact genetically with members of the non-canonical (beta-catenin independent) Wnt signaling pathway. Here we propose to investigate the link between renal cystic disease and Wnt signaling. First, we will establish the renal phenotype of mice ablated specifically for Bbs1, Bbs4 and Bbs6, all of which have been implicated in ciliary/basal body function, and monitor the activity of beta-catenin during renal development by means of a lacZ reporter. In parallel, to explore the potential role of the basal body in common renal disease, we will explore the possible synergy between BBS and PKD by introducing a heterozygous Pkd1 or Pkhdl null allele in Bbs mutant lines and determine whether there is genetic interaction. Second, we will investigate the biochemical nature of the Wnt defect in basal body mutants and suppressants and determine the behavior and cellular distribution of a series of Wnt-responsive proteins such as b-catenin and Dishevelled. Finally, we will combine the power of robust in vitro Wnt response assays with recent studies that heavily enriched for novel ciliary and basal body proteins to identify new components of the cilium that regulate the intracellular Wnt response. Establishing the link between the basal body and the cilium with Wnt signaling represents a potential paradigm shift in renal cystic disease and will likely lead to a profoundly novel means of approaching treatment and prevention.