ROLE OF SPARC IN THE MODULATION OF GLOMERULAR INJURY

SPARC 在调节肾小球损伤中的作用

• 批准号: 6357047
• 负责人: WILLIAM G COUSER
• 金额: $ 12.07万
• 依托单位: UNIVERSITY OF WASHINGTON
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-09-01 至 2001-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6357047
• 关键词: basement membrane; cell cycle; cell growth regulation; cell proliferation; collagen; disease /disorder model; extracellular matrix proteins; gene expression; gene targeting; genetically modified animals; glomerulonephritis; growth factor receptors; growth inhibitors; immunocytochemistry; interstitial nephritis; laboratory mouse; mesangium; polymerase chain reaction; protein biosynthesis; protein isoforms; renal glomerulus; site directed mutagenesis; tissue /cell culture; transforming growth factors

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.

SPARC(富含半胱氨酸的酸性分泌蛋白)是一种基质细胞 由肾小球和间质细胞合成的具有多种性质的蛋白质 这在肾脏对损伤的反应中可能很重要，包括抗- 粘附性和抗增殖性以及对合成的影响 I型胶原蛋白的分泌。在原始项目中的研究1 2、我们发现肾小球系膜细胞和肾小球系膜细胞上调SPARC的表达。 上皮细胞和间质成纤维细胞对 几种形式的肾损伤，与细胞的分辨率有关 增殖并与I型胶原沉积共定位 增加了。当SPARC在体内注入大鼠模型时 系膜增生性肾小球肾炎，有明显上调 转化生长因子β、I型胶原和纤维连接蛋白在肾小球系膜和肾小球系膜的沉积 肾间质。在这个项目中，我们将进一步分析 SPARC、TGFβ细胞增殖与基质的关系 肾脏疾病中的沉积。在这个项目的第一个具体目标中，我们将 利用SPARC基因敲除的肾小球系膜细胞和上皮细胞 野生型小鼠以及重组人SPARC(RSPARC)和几种 突变的SPARC蛋白水平的探索(转录 翻译，翻译后)，SPARC在其中调制生产 转化生长因子β亚型、受体和I/IV胶原蛋白的产生。我们将尝试 恢复SPARC中I型胶原的产生和细胞周期穿越的速率 通过添加TGFbeta和/或rSPARC来敲除细胞，我们将定义 SPARC中影响肾细胞增殖的序列 和利用突变的rSPARC蛋白或 在特定的目标#2中，我们将转移到体内 SPARC基因敲除和野生型小鼠及SPARC的建立和利用 表达突变SPARC的基因敲除小鼠分析SPARC和 它的各个结构域对肾小球和间质细胞增殖的影响， 转化生长因子β和I型胶原沉积与肾小球上皮细胞 体内基底膜脱离。这些研究将提供新的 对一种重要的新分子在调节细胞周期中的作用的见解 肾脏对损伤的反应和确定个体侮辱是否为铅 解决和修复或进展为终末期肾病。