IgA肾病患者血清aIgA1对足细胞增殖及nephrin分子表达的影响

目的：观察IgA肾病（IgA nephropathy,IgAN）患者与正常人的血清热聚合IgA1（aggregated IgA1,aIgA1）对足细胞增殖及nephrin分子表达的影响。方法：利用亲和层析联合分子筛层析法分离获得原发性IgAN患者与健康人血清单体IgA1（monomeric IgA1,mIgA1）,将mIgA1热聚合为aIgA1,分别刺激小鼠MPC5足细胞株,利用MTT法检测aIgA1对足细胞增殖的影响,用RT-PCR法检测aIgA1干预后足细胞nephrin分子基因表达水平的改变。结果：不同浓度aIgA1刺激组间足细胞MTT吸光度的差异有统计学意义（P〈0.05）。RT-PCR实验发现正常人及患者的aIgA1刺激足细胞后,均可以时间依赖性及剂量依赖性的方式下调nephrin mRNA的表达,且患者的aIgA1下调nephrin表达的作用更明显（P〈0.01）。结论：IgAN患者与正常人的aIgA1均可以影响足细胞增殖,并下调足细胞nephrin mRNA的表达。患者aIgA1对足细胞nephrin mRNA表达的下调作用较正常人明显,在疾病过程中IgA1可能是加重足细胞损伤的原因之一。

The Effects of aIgA1 From Patients with IgA Nephropathy on Podocyte Proliferation and Expression of Nephrin

Objective：To explore the effects of aIgA1 isolated from both patients with IgAN and healthy controls on proliferation of podocyte and expression of nephrin.Methods：Blood samples of patients with primary IgAN and healthy controls were collected.Serum monomeric IgA1（mIgA1） was isolated with jacalin affinity chromatography and Sephacryl S-200 HR chromatography,then heated to aggregated form（aIgA1）.Mouse podocyte（MPC5） was cultured in vitro,then the effects of aIgA1 on proliferation of podocyte through MTT were observed.The expression of nephrin mRNA in mouse podocyte was detected with RT-PCR after stimulated by aIgA1.Results：There was a significant difference between the MTT absorbency of podocyte in different concentration stimulate groups of aIgA1（P0.05）.Both of aIgA1 from patient and health control could down regulate the expression of nephrin mRNA in a time and concentration-dependent manner,and the role of patient ＇s aIgA1 in down regulation was very apparent（P0.01）.Conclusion：The results suggest that podocyte could response to IgA1 in direct manner,aIgA1 could affect proliferation of podocyte;Both of aIgA1 from patient and health control could down regulate the expressions of nephrin mRNA in a time and concentration-dependent manner,and the role of patient ＇s aIgA1 in downregulation was more apparent than healthy control,IgA1 could aggravate the damage of podocyte in the process of disease.