Nephrin and podocin dissociate at the onset of proteinuria in experimental membranous nephropathy
Nephrin and podocin dissociate at the onset of proteinuria in experimental membranous nephropathy
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DOI：
10.1111/j.1523-1755.2005.00328.x
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发表时间：
2005-06-01
影响因子：
19.6
通讯作者：
Kawachi, H
中科院分区：
文献类型：
--
作者：
Nakatsue, T;Koike, H;Kawachi, H
背景狭缝隔膜在维持肾小球毛细血管壁的屏障功能中起关键作用。膜性肾病蛋白尿的发病机制尚不清楚。本研究旨在探讨裂膈在实验性膜性肾病蛋白尿发生中的作用。通过免疫荧光和Western印迹分析，分析了被动和主动Heymann肾炎中狭缝细胞相关分子（nephrin、podocin和CD2AP）和其他足细胞相关分子（podocalyxin和α 3整合素）的表达和定位。采用双标记免疫荧光方法研究了狭缝隔膜相关分子的相互作用。并对这些分子的mRNA表达进行分析。在被动海曼肾炎的早期阶段检测到nephrin和podocin染色模式的变化，从线性到颗粒状。这些变化是不平行的，这些分子的解离检测的双标记免疫荧光方法在被动和主动海曼肾炎。Western印迹分析与顺序溶解的材料表明，肾蛋白丰富的馏分从部分洗涤剂耐洗涤剂主要是洗涤剂可溶性的变化。podocin没有发生这种变化。在被动性海曼肾炎的早期阶段就已经检测到尿中排泄的Nephrin。nephrin和podocin的mRNA表达在蛋白尿发生前就已降低。而α 3整合素的表达在本研究中未观察到广泛的变化。在海曼肾炎的早期阶段，Nephrin与podocin分离并排泄到尿液中。nephrin和podocin的表达减少，沿着它们的解离，可能有助于Heymann肾炎中蛋白尿的发展。
Background. The slit diaphragm plays a critical role in maintaining the barrier function of the glomerular capillary wall. The pathogenic mechanism of proteinuria in membranous nephropathy remains uncertain. This study was undertaken to analyze the pathogenic role of slit diaphragm in proteinuria in experimental membranous nephropathy.Methods. The expression and the localization of slit diaphragm-associated molecules (nephrin, podocin, and CD2AP) and other podocyte-associated molecules (podocalyxin and alpha(3) integrin) in passive and active Heymann nephritis were analyzed by immunofluorescence and Western blot analysis. The interaction of slit diaphragm-associated molecules was investigated by the dual-labeling immunofluorescence method. The mRNA expression of these molecules was also analyzed.Results. Shifts in nephrin and podocin staining patterns, from linear to granular, were detected in the early stages of passive Heymann nephritis. These shifts were not parallel, and the dissociation of these molecules was detected by the dual-labeling immunofluorescence method in passive and active Heymann nephritis. Western blot analyses with sequentially solubilized materials indicated that the nephrin-rich fraction changed from being partly detergent-resistant to being predominantly detergent-soluble. This change did not occur with podocin. Nephrin excreted into urine was already detected in the early stages of passive Heymann nephritis. Decreased mRNA expression of nephrin and podocin was observed before the onset of proteinuria. By contrast, no extensive change in the expression Of alpha(3) integrin was observed in this study.Conclusion. Nephrin is dissociated from podocin and excreted into urine in the early stages of Heymann nephritis. The reduced expression of nephrin and podocin, along with their dissociation, may contribute to the development of proteinuria in Heymann nephritis.