Glomerular Capillaries-- Normal and Pathologic

在过去的39年里，在这笔拨款下，我们的研究一直致力于了解 肾小球通透性和蛋白质吸收的细胞和分子机制以及 发生在肾小球疾病中的这些过程中的紊乱。这项研究中提出的实验 应用程序代表了我们正在进行的关于狭缝隔膜和 GIV在足细胞损伤后功能和存活中的作用我们将重点关注三个具体目标： 具体目标#1：描述和确定新的、假定的狭缝隔膜的功能 用MS和定量细胞器蛋白质组学鉴定了裂隙膜组分中的成分。我们会 验证它们的连接定位，并确定它们在足细胞中的结合伙伴和功能。 特定目的#2：研究GIV在介导Akt信号转导和细胞被动存活中的作用 海曼肾炎，局灶性肾小球硬化，糖尿病肾病。在泛肾病中GIV是 上调后，组装成VEGFR2/GIV/Gal3复合体，并发挥维持足细胞生存的功能。我们 将确定GIV是否在与足细胞损伤相关的其他疾病中发挥类似的作用。 具体目标#3：进一步研究地理信息系统影响的机制和时空方面 足细胞。我们的初步数据表明，GIV可能在局灶性粘连(FA)和/或狭缝中发挥作用 当它与纽蛋白和VEGFR2在FA共定位时，横隔膜与CD2AP结合。我们将调查 GIV与VEGFR2和CD2AP之间相互作用的动态变化 连接分析和超分辨率IF成像(STORM)以确定相互作用发生的位置，并进行测试 GIV缺失或GIV突变体的表达是否影响FA或连接的形成。 这些研究有望为理解细胞和分子机制提供新的见解。 肾小球滤过和肾小球损伤的机制及其在肾小球疾病中的变化 与蛋白尿有关。 相关性(请参阅说明)： 足细胞损伤是许多肾小球疾病的始发原因。计划中的研究将提供关键 对调控足细胞组织、功能和生存的信号网络的洞察 蛋白尿相关疾病中的肾小球损伤。

During the last 39 years under this grant our research has been directed toward understanding the cellular and molecular mechanisms of glornerular permeability and protein absorption as well as the derangements in these processes that occur in glomerular diseases. The experiments proposed in this application represent a direct continuation of our ongoing work on characterization of slit diaphragms and the role of GIV in podocyte function and survival after podocyte injury. We will focus on three specific aims: Specific Aim # 1 : To characterize and determine the functions of novel, putative slit diaphragm components identified by MS and quantitative organellar proteomics in slit diaphragm fractions. We will verify their junctional localization and determine their binding partners and functions in podocytes. Specific Aim #2: To investigate the role of GIV in mediating Akt signaling and cell survival in passive Heymann nephritis, focal glomerulosclerosis, and diabetic nephropathy. In PAN nephrosis GIV is upregulated, assembles a VEGFR2/GIV/Gal3 complex, and functions to maintain podocyte survival. We will determine if GIV plays a similar role in other diseases associated with podocyte injury. Specific Aim #3: To further investigate the mechanisms and spatial-temporal aspects of GIV's effects on podocytes. Our preliminary data indicate that GIV might function at focal adhesions (FA) and/or at slit diaphragms as it colocalizes with vinculin and VEGFR2 at FA and it binds CD2AP. We will investigate the dynamics ofthe interactions between GIV and VEGFR2 and CD2AP by live cell imaging, use proximity ligation assays and superresolution IF imaging (STORM) to determine where interaction occurs, and test whether GIV depletion or expression of GIV mutants affect FA or junction formation. These studies can be expected to provide novel insights into understanding ofthe cellular and molecular mechanisms of glomerular filtration and glomerular injury and their alterations in glomerular diseases associated with proteinuria. RELEVANCE (See instructions): Podocyte injury is the initiating cause of many glomerular diseases. The studies planned will provide key insights into the signaling neworks that regulate podocyte organization, functions and survival in response to glomerular injury in diseases associated with proteinuria.