Role of primary cilium-generated signaling in polycystic kidney disease

原代纤毛产生的信号在多囊肾病中的作用

• 批准号: 10550150
• 负责人: Saikat Mukhopadhyay
• 金额: $ 61.07万
• 依托单位: UT SOUTHWESTERN MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-01-15 至 2025-11-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10550150
• 关键词: Acceleration; Address; Adenylate Cyclase; Adolescent; Adult; Affect; Age; Ankyrin Repeat; Automobile Driving; Autosomal Dominant Polycystic Kidney; Binding; Biological; Biosensor; Cell Culture Techniques; Cells; Cilia; Collaborations; Complex; Coupling; Cultured Cells; Cyclic AMP; Cyclic AMP-Dependent Protein Kinases; Cyst; Data; Defect; Development; Dilatation - action; Disease; Disease Progression; Disease model; Embryo; Epithelium; Exclusion; Exhibits; GTP-Binding Proteins; Genes; Genetic Epistasis; Growth; Guanosine Triphosphate Phosphohydrolases; Human; Kidney; Knock-out; Liquid substance; Membrane; Membrane Proteins; Modeling; Molecular; Molecular Conformation; Molecular Target; Mus; Mutation; Nature; Output; PKD1 gene; PKD2 gene; PKD2 protein; Pathogenesis; Pathway interactions; Polycystic Kidney Diseases; Protein Family; Protein Subunits; Proteins; Renal function; Renal tubule structure; Reporting; Repression; Research Personnel; Role; Signal Pathway; Signal Transduction; Testing; Tubular formation; conditional knockout; extracellular; in vivo; inhibitor; insight; mouse model; mutant; nephrogenesis; new therapeutic target; novel; polycystic kidney disease 1 protein; predictive modeling; prevent; promoter; protein transport; public health relevance; renal epithelium; response; synergism; trafficking

Abstract Autosomal dominant polycystic kidney disease (ADPKD) is characterized by the development of fluid-filled sacs called cysts in both kidneys, but key signals that cause cyst formation are unknown. Multiple downstream cellular pathways are dysregulated during cystogenesis. However, targeting these pathways has limited effects on ADPKD treatment. ADPKD is caused by mutations in genes encoding for polycystin-1 (PC1) and polycystin-2 (PC2). Both polycystins localize to primary cilia. The primary cilium instructs cellular decisions in response to extracellular inputs by compartmentalizing subcellular signaling. However, the role of primary cilium in kidney cystogenesis is inherently complex. Loss of polycystins causes severe cystogenesis, which is mostly cilia- dependent, while loss of cilia by itself causes smaller cysts. These results suggest that a complex interplay between counter-regulatory positive and negative signals in cilia inhibit cyst formation in normal renal tubules and promote cyst growth in ADPKD, respectively. Identifying these signals could have profound impacts on novel therapeutic targets and strategies for ADPKD. However, uncoupling ciliary signals causing cystogenesis from downstream signaling pathways affected during cystogenesis and the difficulty in identification of ciliary signals in absence of cilia have prevented their identification. Here, by studying the ciliary trafficking adapter, tubby family protein Tulp3, we aim to identify and target the key upstream ciliary signals that regulate cystogenesis. We previously showed that Tulp3 functions in ciliary trafficking of membrane proteins without affecting respective protein levels or disrupting cilia by coupling to the intraflagellar transport complex A (IFT-A). We recently showed that embryonic kidney-specific conditional knockouts of Tulp3 developed renal cystogenesis that was less severe than from polycystin loss. Concomitant Tulp3 loss did not inhibit cystogenesis upon PC1 loss, unlike ciliary disruption, but caused early lethality, suggesting accelerated loss of renal function. These results further reinforce the polycystin independent inhibitory role of ciliary proteins in cystogenesis. Other groups have reported suppression of cystogenesis in adult mouse models of PKD from Tulp3 or IFT-A loss. Thus, we hypothesize that Tulp3-regulated ciliary cargoes determine cilia-dependent cyst inhibition during development and PC1/2- inhibited cilia-dependent cyst activation in adults. Here by leveraging our expertise in ciliary trafficking and signaling and using novel mouse models to block trafficking of potential cargo subtypes, we propose to identify ciliary regulators of cystogenesis. In Aim 1, we will determine novel Tulp3 trafficked ciliary cargoes and signaling outputs in cilia relevant to cystogenesis. In Aim 2, we will determine Tulp3 regulated cyst inhibitory ciliary cargo subtypes that genetically synergize with PC1 during murine kidney development. In Aim 3, we will test Tulp3 cargo subtypes as promoters of cystogenesis in adult mouse models of PKD in vivo using genetic epistasis. Our approach will determine dual ciliary drivers impacting cystogenesis in vivo during adult-onset ADPKD and embryonic-onset cystic disease unraveling the molecular nature of cilium-generated signaling in either setting.

抽象的 常染色体显性多囊肾病 (ADPKD) 的特点是充满液体的囊的发育 称为双肾囊肿，但导致囊肿形成的关键信号尚不清楚。多个下游蜂窝 途径在囊肿发生过程中失调。然而，针对这些途径的效果有限 ADPKD 治疗。 ADPKD 是由编码多囊蛋白-1 (PC1) 和多囊蛋白-2 的基因突变引起的 （电脑2）。两种多囊蛋白都定位于初级纤毛。初级纤毛指导细胞做出响应的决定 通过划分亚细胞信号传导来进行细胞外输入。然而，初级纤毛在肾脏中的作用 囊肿发生本质上是复杂的。多囊蛋白的丢失会导致严重的囊肿发生，其中大部分是纤毛- 依赖，而纤毛本身的损失会导致更小的囊肿。这些结果表明复杂的相互作用 纤毛中的反调节正信号和负信号之间抑制正常肾小管囊肿的形成 并分别促进 ADPKD 中的囊肿生长。识别这些信号可能会对小说产生深远的影响 ADPKD 的治疗目标和策略。然而，解偶联纤毛信号导致囊肿发生 下游信号通路在囊肿发生过程中受到影响以及纤毛信号识别的困难 由于没有纤毛，无法识别它们。在这里，通过研究纤毛运输适配器，tubby 家族蛋白 Tulp3，我们的目标是识别和靶向调节囊肿发生的关键上游纤毛信号。 我们之前表明 Tulp3 在膜蛋白的纤毛运输中发挥作用，而不影响各自的 通过与鞭毛内转运复合物 A (IFT-A) 偶联来调节蛋白质水平或破坏纤毛。我们最近展示了 胚胎肾脏特异性条件性敲除 Tulp3 导致肾囊肿发生，但不那么严重 比多囊蛋白损失。与睫状体不同，伴随的 Tulp3 丢失并不会在 PC1 丢失后抑制囊肿发生 破坏，但导致早期死亡，表明肾功能加速丧失。这些结果进一步 增强纤毛蛋白在囊肿发生中的独立于多囊蛋白的抑制作用。其他团体也报道过 Tulp3 或 IFT-A 缺失导致的 PKD 成年小鼠模型中的囊肿发生受到抑制。因此，我们假设 Tulp3 调节的纤毛货物决定发育和 PC1/2- 过程中纤毛依赖性囊肿抑制 抑制成人纤毛依赖性囊肿激活。在这里，利用我们在纤毛贩运方面的专业知识和 发出信号并使用新颖的小鼠模型来阻止潜在货物亚型的贩运，我们建议确定 膀胱发生的纤毛调节因子。在目标 1 中，我们将确定新型 Tulp3 贩运的纤毛货物和信号 纤毛的输出与囊肿发生相关。在目标 2 中，我们将确定 Tulp3 调节的囊肿抑制纤毛货物 在小鼠肾脏发育过程中与 PC1 具有遗传协同作用的亚型。在目标 3 中，我们将测试 Tulp3 使用遗传上位性在体内 PKD 成年小鼠模型中将货物亚型作为囊肿发生的促进剂。我们的 方法将确定在成人发病的 ADPKD 期间影响体内囊肿发生的双重纤毛驱动因素 胚胎发病的囊性疾病揭示了两种情况下纤毛产生的信号传导的分子性质。