Mechanisms of Polycystin and Cilia Function in ADPKD

项目负责人/主要研究者（最后，第一，中间）：Somlo，Stefan 项目总结/摘要 人类多囊肾疾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质产物 在纤毛-基体复合体中表达。肾囊肿的发生有一个共同的表型， 这两类基因中的任何一种突变都导致了受以下因素影响的细胞途径的概念方程： 多囊蛋白-1（PC 1）或多囊蛋白-2（PC 2）的损失与结构完整纤毛损失后受影响的那些。 这个建议是基于我们的新观察，即在Pkd 1或Pkd 2失活后形成囊肿。 如果结构完整的纤毛同时被消融，PKD 2会明显减慢。这种影响存在于成年人 Pkd 1和Pkd 2的发病和早期发育小鼠模型，并且与遗传无关 纤毛消融机制这一发现为一种途径提供了遗传学证据， PC 1/PC 2复合物，并且需要完整的纤毛在缺乏 PC 1/PC 2-纤毛依赖性囊肿激活（CDCA）途径。本建议的目的是确定 CDCA途径的组成部分。为了实现这一目标，我们将定义 多囊蛋白失活后的活性受存在或不存在调节的囊肿进展 完整的纤毛。我们将使用一系列高度相关的体内小鼠模型，这些模型涵盖了CDCA的所有阶段。 研究已知的和新的候选CDCA途径。我们将补充这些指导性研究， 转录组学和蛋白质组学发现方法。我们已经确定整合素信号作为候选者 CDCA活性。我们将探讨多囊蛋白在纤毛整合素信号传导中的作用，并确定 该途径的组分在纤毛中是活性的。我们将在细胞中使用基因敲除和条件敲除 在小鼠模型中确定整合素信号传导是否是CDCA的一个组成部分，如果是，我们将靶向它， 在治疗上确定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（修订版06/09）第59页延续格式页

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