细胞骨架蛋白巢蛋白在人肾足细胞中的表达及意义

Expression of nestin in human kidney and its clinical significance

目的 检测细胞骨架蛋白巢蛋白在成人正常及病理状态肾组织中的表达，并观察其表达水平与患者尿蛋白的关系，初步探讨巢蛋白与足细胞损伤的关系。方法 正常对照肾组织（外科手术切除）6例，应用免疫组织化学（SP法）和免疫电镜检测巢蛋白的表达；病理状态肾组织：IgA肾病（无蛋白尿，电镜观察无足突融合，IgA—np）4例；IgA肾病（有蛋白尿，IgA—p）17例；膜性肾病8例；局灶性节段性肾小球硬化3例。应用免疫组织化学及即时RT-PCR的方法检测巢蛋白在肾组织中的表达并进行半定量、定量分析，与患者尿蛋白水平进行比较，分析两者之间相关关系。结果 巢蛋白表达在成人正常肾组织的足细胞初级足突中；免疫组织化学半定量及即时RT-PCR结果显示：IgA-np中巢蛋白的表达水平与正常肾组织差异无统计学意义；IgA-P、局灶性节段性肾小球硬化、膜性肾病中，巢蛋白的表达比正常肾组织显著降低（P〈0．05），并与24h尿蛋白呈负相关（r=-0．43，P〈0．05）。结论 巢蛋白在足细胞中低表达与肾小球中足细胞的损伤有关。

Objective To study the expression and significance of nestin （a type of cytoskeletal protein） in normal and diseased human kidneys. Methods Diseased kidney tissues were obtained from needle biopsies in 32 patients with glomerulonephritis （ including 8 cases of membranous glomerulopathy, 3 eases of focal segmental glomerulosclerosis, 17 cases of IgA nephropathy with proteinuria and 4 cases of IgA nephropathy without proteinuria）. Control kidney tissues were obtained from nephrectomy specimens for renal tumors. The expression of nestin in the control kidney tissues was studied using immunoelectronic microscopy and immunohistochemistry. The expression of nestin in the diseased kidney tissues was detected by immunohistochemistry and real-time reverse transcription-polymerase chain reaction. Results In normal kidney tissues, nestin was detected at the periphery of glomerular capillary loops. Semi-quantitative morphometric analysis showed that the glomerular nestin expression level in cases of IgA nephropathy without proteinuria did not differ from that in the normal controls. However, the glomerular nestin expression levels in cases of IgA nephropathy with proteinuria, membranous glomerulopathy and focal segmental glomerulesclerosis were significantly lower than those in the normal kidneys and IgA nephropathy without proteinuria. The glomerular nestin expression levels inversely correlated with the 24-hour urine protein results. Condusion Nestin may play an important role in maintaining the normal function of podocytes in human kidney.