Mechanisms of Polycystin and Cilia Function in ADPKD

项目主任/首席调查员(最后、第一、中间)：Somlo，Stefan 项目摘要/摘要 人类多囊肾病和纤毛之间的功能联系部分是基于重叠 突变导致肾囊肿形成的基因和蛋白产物为 表达于纤毛-基底体复合体。以下是一种常见的表型，即肾囊肿 这两类基因中的任何一种的突变都导致了影响细胞通路的概念性方程式 多囊蛋白-1(PC1)或多囊蛋白-2(PC2)的丢失与结构完整的纤毛丢失后受影响的那些。 这一建议是基于我们新的观察结果，即在PKD 1或PKD失活后形成囊泡 如果结构完整的纤毛同时被消融，则PKD2明显减慢。这种影响在成人中存在。 PKD1和PKD2的发病和早期发育小鼠模型，并且不依赖于基因 纤毛消融的机制。这些发现提供了基因证据，证明了一条被 PC1/PC2复合体，需要完整的纤毛才能在没有PC1/PC2的情况下产生最大的促囊信号 PC1/PC2-纤毛依赖性胞囊激活(CDCA)通路。这项提案目的是确定 CDCA途径的组成部分。为了实现这一目标，我们将定义以下具体决定因素 多囊藻毒素失活后活性受存在或不存在影响的囊性进展 完整的纤毛。我们将使用一系列高度相关的体内小鼠模型，包括CDCA的所有阶段 研究已知的和新的候选CDCA途径。我们将对这些定向研究进行补充 转录组和蛋白质组发现方法。我们已经确定整合素信号是一个候选 CDCA活性。我们将探索多囊蛋白在纤毛整合素信号中的作用，并确定 纤毛是这一途径的活性成分。我们将在细胞中使用基因敲除和条件敲除 在小鼠中建立模型，以确定整合素信号是否是CDCA的一个组成部分，如果是，我们将针对它 从治疗学角度确定ADPKD的临床前疗效。整个计划提供了两个新的发现 关于ADPKD的发病机制，每一个都有很大的翻译潜力。 PHS 398/2590(06/09版)第59页续格式页

Program Director/Principal Investigator (Last, First, Middle): Somlo, Stefan Project Summary/Abstract The functional connection between human polycystic kidney diseases and cilia is based in part on the overlap between genes whose mutation results in kidney cyst formation and genes whose protein products are expressed in the cilia-basal body complex. The occurrence of a common phenotype, kidney cysts, following mutation in either of these classes of genes has led to a conceptual equation of cellular pathways affected by loss of polycystin-1 (PC1) or polycystin-2 (PC2) with those affected following loss of structurally intact cilia. This proposal is based on our novel observation that cyst formation following inactivation of either Pkd1 or Pkd2 is markedly slowed if structurally intact cilia are concomitantly ablated. This effect is present in adult onset and early developmental mouse models of both Pkd1 and Pkd2 and is independent of the genetic mechanism of cilia ablation. The findings provide genetic evidence for a pathway that is inhibited by the PC1/PC2 complex and that requires intact cilia to produce maximal cyst promoting signals in the absence of PC1/PC2-a Cilia Dependent Cyst Activating (CDCA) pathway. The objective of this proposal are to identify the components of the CDCA pathway. To achieve this objective, we will define the specific determinants of cyst progression whose activity following inactivation of polycystins is modulated by the presence or absence of intact cilia. We will use a highly correlated series of in vivo mouse models that subsume all stages of CDCA to investigate known and novel candidate CDCA pathways. We will complement these directed studies with transcriptomic and proteomic discovery approaches. We have identified integrin signaling as a candidate CDCA activity. We will explore the role of polycystins in integrin signaling in cilia and determine which components of this pathway are active in cilia. We will use gene knockdown in cells and conditional knockout models in mice to determine whether integrin signaling is a component of CDCA and if so, we will target it therapeutically to determine preclinical efficacy in ADPKD. The overall program offers two novel discoveries regarding the pathogenesis of ADPKD that each have substantial potential for translation. PHS 398/2590 (Rev. 06/09) Page 59 Continuation Format Page