ROLE OF SPARC IN THE MODULATION OF GLOMERULAR INJURY

分泌蛋白（分泌蛋白酸性和富含半胱氨酸）是一种基质细胞 由肾小球和间质细胞产生的蛋白质，具有几种性质 这可能是重要的肾脏反应损伤，包括抗- 粘附和抗增殖作用以及对合成的影响 和I型胶原蛋白的分泌。在原项目1的研究中 2.肾小球系膜细胞上调TGF β 1表达， 上皮细胞以及间质成纤维细胞对 与细胞消退相关的几种形式的肾损伤 增殖并与I型胶原沉积共定位， 增加当在大鼠模型中体内输注顺铂时， 系膜增生性肾小球肾炎中， TGF β、I型胶原和纤连蛋白在系膜中沉积， 肾结石在本项目中，我们将进一步分析 TGF β细胞增殖与基质的关系 肾脏疾病中的沉积。在本项目的具体目标#1中，我们将 利用来自β 2受体敲除的肾小球系膜和上皮细胞， 野生型小鼠以及重组人IFN（rIFN）和几种 突变的p53蛋白，以探索水平（转录 翻译的，翻译后的），在此， TGF β同种型、受体和胶原蛋白I/IV的产生。我们将尝试 恢复胶原蛋白I的生产和细胞周期穿越率， 通过加入TGF β和/或rf3基因敲除细胞，我们将定义 负责影响肾细胞增殖的基因序列 和利用突变的rfos蛋白的胶原蛋白I/TGF β生产，或 转染的cDNA。在具体目标#2中，我们将转向体内 建立并利用了EST3基因敲除小鼠和野生型小鼠以及EST3基因敲除小鼠， 基因敲除小鼠表达突变的p53，以分析p53的作用， 其单个结构域对肾小球和间质细胞增殖的影响， TGF β和I型胶原沉积与肾小球上皮细胞 在体内从基底膜脱离。这些研究将提供新的 深入了解一种重要的新分子在调节 肾对损伤的反应，并确定是否个别损害导致 解决和修复或进展到终末期肾病。

SPARC (Secreted Protein Acidic and Rich in Cysteine) is a matricellular protein made by glomerular and interstitial cells with several properties that may be important in the renal response to injury including anti- adhesive and anti-proliferative effects as well as effects on synthesis and secretion of type I collagen. In studies in the original Projects 1 and 2, we found that SPARC was up-regulated by glomerular mesangial and epithelial cells as well as interstitial fibroblasts in response to several forms of renal injury, correlated with resolution of cell proliferation and co-localized with deposition of type I collagen was increased. When SPARC was infused in vivo in a rat model of mesangioproliferative glomerulonephritis, there was a marked up-regulation of TGFbeta, collagen I and fibronectin deposition in the mesangium and renal interstitium. In this project, we will further analyze the relationship between SPARC, TGFbeta cell proliferation and matrix deposition in renal disease. In Specific Aim #1 of this project, we will utilize glomerular mesangial and epithelial cells from SPARC knockout and wild-type mice as well as recombinant human SPARC (rSPARC) and several mutated SPARC proteins to explore the levels (transcriptional translational, post-translational) at which SPARC modulates production of TGFbeta isoforms, receptors and collagen I/IV production. We will attempt to restore collagen I production and rate of cell cycle traverse in SPARC knockout cells by addition of TGFbeta and/or rSPARC and we will define the sequences within SPARC responsible for effects on renal cell proliferation and collagen I/TGFbeta production utilizing mutated rSPARC proteins or transfected cDNA's. In Specific Aim #2, we will move to the in vivo setting and utilize SPARC knockout and wild-type mice as well as SPARC knockout mice expressing mutated SPARC to analyze the effect of SPARC and its individual domains on glomerular and interstitial cell proliferation, TGFbeta and collagen I deposition and glomerular epithelial cell detachment from basement membrane in vivo. These studies will provide new insights into the role of an important new molecule in modulating the renal response to injury and determining whether individual insults lead to resolution and repair or progression to end stage renal disease.