Role of CLIC5 in Podocyte Injury and Remodeling

描述(申请人提供)：在许多肾小球疾病中，蛋白尿和疾病进展与死亡或脱离导致的足细胞丢失有关。了解足细胞在损伤后通过重塑其大突起和足突维持附着和恢复的机制对于确定肾小球疾病的潜在治疗靶点至关重要。足突蛋白是一种顶膜蛋白，是足细胞大突起和足突形成所必需的。唾液酸化和Podocalyin表达的减少与肾小球疾病有关。细胞内氯离子通道5(CLIC5)是一种与Podocalyin和Ezrin结合的顶膜蛋白，是细胞膜和细胞骨架网络之间的重要中间适配器。我们最近发现，CLIC5缺陷的足细胞表现为足突消失和足突蛋白表达减少。与正常活体供者相比，微小病变病患者CLIC5蛋白表达降低。我们的长期目标是识别和了解肾小球损伤后足细胞存活和重塑所必需的蛋白质和信号通路。这项提议的目的有两个。首先，我们将确定CLIC5在多大程度上控制足细胞过程中足细胞毒素的适当运输和稳定性。其次，我们将在体内确定CLIC5在肾小球损伤后维持足细胞黏附中的作用。这个项目意义重大，因为我们将展示一种对足细胞损伤恢复至关重要的新机制。生化和细胞生物学方法的结合将被用于培养的缺乏Clic5的足细胞和缺乏Clic5的小鼠。我们期望通过维持足细胞对肾小球基质的黏附，将CLIC5确定为对足细胞恢复至关重要的蛋白质，并重塑足突以重建肾小球滤过屏障。这些实验结果可能有助于为合理设计有效的肾小球疾病临床干预措施奠定基础。

DESCRIPTION (provided by applicant): In many glomerular diseases, proteinuria and disease progression are associated with podocyte loss by death or detachment. Understanding the mechanisms by which the podocyte maintains attachment and recovers by remodeling its large and foot processes after injury is critical for the identification of potential therapeutic targetsof glomerular diseases. Podocalyxin is an apical membrane protein that is required for the formation of podocyte large and foot processes. A decrease in the sialylation and expression of podocalyxin are associated with glomerular diseases. Chloride intracellular channel 5 (CLIC5) is an apical membrane protein that associates with podocalyxin and ezrin, and is an important intermediate adapter between the cell membrane and the cytoskeletal network. We have recently discovered that CLIC5-deficient podocytes display foot process effacement and a decrease in podocalyxin protein expression. CLIC5 protein expression is decreased in Minimal Change Disease compared with normal human living donors. Our long term goal is to identify and understand the proteins and signaling pathways necessary for podocyte survival and remodeling in response to glomerular injury. The aims of this proposal are twofold. First, we will determine the extent to which CLIC5 controls the proper trafficking and stability of podocalyxin in podocyte processes. Second, we will identify the role of CLIC5 in maintaining podocyte adhesion in response to glomerular injury in vivo. This project is significant because we will demonstrate a novel mechanism that is critical for podocyte recovery from injury. A combination of biochemical and cell biological approaches will be employed in cultured Clic5-deficient podocytes and Clic5-deficient mice. We expect to identify CLIC5 as a protein critical for podocytes to recover by maintaining their adherence to the glomerular matrix and to remodel their foot processes to reestablish the glomerular filtration barrier. The results of these experiments may aid in establishing a foundation for the rational design of effective clinical interventions for glomerular diseases.