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: 6239129
• 负责人: WILLIAM G COUSER
• 金额: $ 11.9万
• 依托单位: UNIVERSITY OF WASHINGTON
• 依托单位国家: 美国
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-09-01 至 1998-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6239129
• 关键词: cell growth regulation; disease /disorder model; gene expression; glomerulonephritis; immunocytochemistry; in situ hybridization; laboratory rat; mesangium; metalloproteins; neutralizing antibody; northern blottings; platelet derived growth factor; protein biosynthesis; protein structure function; tissue /cell culture; western blottings

Project 2 will test the hypothesis that SPARC (Secreted Protein Acidic and Rich in Cysteine) modulates the glomerular mesangial and epithelial cell response to injury in vivo. SPARC is an extracellular, calcium- binding, anti-adhesive protein which inhibits the proliferation of several cell types in culture, inhibits cell spreading and favors cell detachment rom extracellular matrix. SPARC inhibits proliferation of some cells by binding to PDGF to prevent PDGF -receptor interaction. Project 1 will explore the molecular mechanisms of SPARC effects on glomerular mesangial cells. In preliminary studies for Project 2, we have shown a marked upregulation of SPARC and PDGF gene expression and protein production in both glomerular epithelial and mesangial cells in response to antibody-complement mediated injury in vivo. In this project we will attempt to determine the pathophysiologic effects of SPARC in experimental renal disease in vivo. In specific aim #1 we will test the hypothesis that SPARC may be an endogenous inhibitor of mesangial cell proliferation which favors resolution rather than progression of glomerulonephritis. This effect may involve inhibition of PDGF. We will determine the kinetics of glomerular SPARC protein production and gene expression in two models of mesangial proliferative glomerular disease, the ATS model of mesangial proliferative glomerulonephritis in which PDGF-mediated mesangial cell proliferation resolves spontaneously and the remnant kidney model in which mesangial cell proliferation is followed by progressive sclerosis. We will correlate SPARC expression with glomerular cell proliferation and PDGF gene and protein expression and determine how SPARC expression relates to recovery from glomerular injury. In specific aim #2 we will determine whether neutralization of SPARC peptide 2.1 (which contains the anti- proliferative domain) with a specific antibody results in a more prolonged course or more severe consequences of mesangial cell proliferation i rats with mesangial proliferative GN. In specific aim #3 we will determine whether SPARC or its derived active peptide 2.1 modulate glomerular epithelial cell proliferation. We will also assess the effects of SPARC and peptides which contain the domains which inhibit cell-matrix interactions (1.1.4.2) on glomerular epithelial cell matrix attachment and shape change in vitro and in vivo. The proposed studies should provide important new information on the mechanisms which regulate progression and resolution of glomerular injury following immunologic insults.

项目2将测试的假设，分泌蛋白酸性 富含半胱氨酸）调节肾小球系膜和上皮细胞 细胞对体内损伤的反应。 钙离子是一种细胞外的，钙离子- 结合，抗粘附蛋白，抑制增殖， 几种细胞类型的培养物，抑制细胞扩散和有利于细胞 从细胞外基质脱落。 抑制增殖 一些细胞通过与PDGF结合来阻止PDGF -受体相互作用。 项目1将探索生物学效应的分子机制， 肾小球系膜细胞 在项目2的初步研究中，我们 已经显示出显著上调的VEGF和PDGF基因表达， 肾小球上皮细胞和系膜细胞的蛋白质产生 对体内抗体-补体介导的损伤的应答。 在这个项目中，我们将试图确定的病理生理影响， 在实验性肾脏疾病中的作用。 具体目标#1， 将测试这一假设，即β-内酰胺酶可能是一种内源性抑制剂， 肾小球系膜细胞增殖，这有利于解决，而不是 肾小球肾炎的进展。 这种影响可能涉及抑制 的PDGF。 我们将测定肾小球滤过蛋白的动力学 两种系膜增生模型的细胞增殖和基因表达 肾小球疾病，系膜增生的ATS模型 血小板源性生长因子介导的系膜细胞增殖的肾小球肾炎 自发消退，残余肾模型中，系膜 细胞增殖之后是进行性硬化。 我们将 VEGF表达与肾小球细胞增殖和PDGF的相关性 基因和蛋白质的表达，并确定表达如何与 从肾小球损伤中恢复 在具体目标#2中，我们将确定 是否中和β-内酰胺酶肽2.1（其含有抗-β-内酰胺酶肽2.1， 增殖结构域）与特异性抗体的结合导致更高的 系膜细胞的病程延长或更严重的后果 增生性肾小球肾炎大鼠模型。 具体目标 #3，我们将确定是否有β-内酰胺酶或其衍生的活性肽2.1 调节肾小球上皮细胞增殖。 我们亦会评估 抑制蛋白和含有抑制蛋白的结构域的肽的作用 肾小球上皮细胞基质上的细胞-基质相互作用（1.1.4.2） 在体外和体内的附着和形状变化。 拟议的研究应提供关于以下方面的重要新资料： 调节肾小球损伤进展和消退的机制 免疫损伤后。