DISTAL COMPLEMENT COMPONENTS IN IMMUNE RENAL INJURY

免疫性肾损伤中的远端补体成分

• 批准号: 3566180
• 负责人: WILLIAM G COUSER
• 金额: $ 30.06万
• 依托单位: UNIVERSITY OF WASHINGTON
• 依托单位国家: 美国
• 财政年份: 1985
• 资助国家: 美国
• 起止时间: 1985-03-01 至 1995-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3566180
• 关键词: affinity chromatography; antibody formation; antigen receptors; antiserum; autoantigens; autoimmune disorder; basement membrane; brush border membrane; complement; complement inhibitors; complement pathway; disease /disorder model; enzyme linked immunosorbent assay; extracellular matrix; gene expression; glomerulonephritis; immune complex; immune complex diseases; immunofluorescence technique; immunoglobulin G; inflammation; laboratory mouse; laboratory rabbit; laboratory rat; laminin; macrophage; membrane activity; membrane permeability; membrane proteins; messenger RNA; metalloenzyme; nephritis; nephrotic syndrome; neutrophil; peptidases; protein biosynthesis; proteinuria; renal tubular transport; renal tubule; synthetic peptide; western blottings; zinc

Membranous nephropathy (MN) is the commonest cause of idiopathic nephrotic syndrome in adults and is a prototype of immune complex induced glomerulonephropathy. The subepithelial deposits which characterize MN in vivo form locally as a consequence of A) antibody binding to antigen(s) on the glomerular epithelial cell (GEC) surface, or B) charge interaction between cationic antigens or antibodies and glomerular anionic sites followed by in situ immune complex formation. The consequences of subepithelial immune deposit formation by both mechanisms include a marked increase in glomerular permeability accompanied by an increase in basement membrane (GBM) thickness due to accumulation of excess normal matrix components produced by the GEC, particularly laminin. Studies in experimental models of MN induced by both of these mechanisms have documented that the complement membrane attack complex, C5b-9, mediates proteinuria in MN, presumably through insertion into the GEC membrane. This project will examine the cellular and molecular consequences of C5b-9 attack on the GEC which may lead to the functional and structural glomerular abnormalities of MN. Three hypotheses will be tested. 1) That GEC C5b-9 attack results in altered synthesis of extracellular matrix components. The effect of C5b-9 attack on GEC in culture on GEC synthesis of type IV collagen, laminin, heparan sulfate proteoglycans and entactin will be studied utilizing metabolic labeling, direct measurement of product in cell supernatant and cell layer/matrix and measurement of GEC mRNA encoding for type IV collagen and laminin. C5b-9 attack on antibody sensitized cultured GEC (analogous the autoimmune mechanism of MN) will be compared to C5b-9 attack on non-sensitized GEC (analogous to exogenous antigen induced MN). 2) The hypothesis that altered GBM permeability in MN results from GEC production of a neutral serine proteinase will be tested by isolating and characterizing a proteinase produced by GEC and measuring the effect of GEC C5b-9 attack on production of this proteinase. 3) The hypothesis that C5b-9 attack on GEC induces proteinuria by causing GEC detachment from basement membrane will be tested by studying the effect of C5b-9 attack initiated by the two mechanisms above on GEC attachment to, or detachment from, various extracellular matrices, and by examining the effect of C5b-9 attack on GEC membrane attachment receptors. The results of these studies should clarify the cellular and molecular basis for glomerular injury induced by C5b-9 in MN as well as in other antibody initiated glomerular diseases.

膜性肾病（MN）是特发性肾病的最常见原因 成人综合征，是免疫复合物诱导的原型 肾小球肾脏病。 表征Mn的上皮下沉积物 由于A）抗体结合与抗原的抗原在本地形式 肾小球上皮细胞（GEC）表面或b）电荷相互作用 阳离子抗原或抗体和肾小球阴离子位点之间 其次是原位免疫复合物的形成。 后果 通过这两种机制形成上皮下皮免疫沉积物 肾小球渗透性增加，伴随着地下室的增加 由于过量正常基质的积累而导致的膜（GBM）厚度 GEC产生的成分，尤其是层粘连蛋白。 研究 这两种机制诱导的MN的实验模型都有 记录了补体膜攻击综合体C5B-9，介导 MN中的蛋白尿，大概是通过插入GEC膜中的。 该项目将检查C5B-9的细胞和分子后果 对GEC的攻击可能导致功能和结构性 Mn的肾小球异常。 将检验三个假设。 1）那 GEC C5B-9攻击导致细胞外基质的合成改变 成分。 C5B-9攻击对文化中GEC对GEC合成的影响 IV型胶原蛋白，层粘连蛋白，硫酸乙酰肝素蛋白聚糖和Entactin 将研究使用代谢标签，直接测量产品的研究 在细胞上清液和细胞层/基质中以及GEC mRNA的测量 编码IV型胶原蛋白和层粘连蛋白。 C5B-9对抗体的攻击 敏化的培养GEC（类似于MN的自身免疫机制）将是 与C5B-9对非敏化GEC的攻击相比（类似于外源 抗原诱导的Mn）。 2）MN中GBM渗透性改变的假设 将测试中性丝氨酸蛋白酶的GEC产生的结果 通过隔离和表征GEC产生的蛋白酶并测量 GEC C5B-9攻击对该蛋白酶产生的影响。 3） C5B-9对GEC的攻击通过引起GEC诱导蛋白尿的假设 从地下膜分离将通过研究 C5B-9攻击是由上述两种机制对GEC附着到或 从各种细胞外矩阵中分离，并检查 C5B-9攻击对GEC膜附着受体的影响。 结果 这些研究应阐明细胞和分子基础 C5B-9在MN以及其他抗体中诱导的肾小球损伤 引发的肾小球疾病。