IL-18在大鼠抗肾小球基底膜肾炎凋亡中作用的研究

Study on IL-18-inducing cell apoptosis in anti-glomerular basement membrane nephritis in rats

目的:探讨IL-18在大鼠抗肾小球基底膜肾炎细胞凋亡中的作用。方法:复制大鼠抗GBM肾炎模型,分别于实验第2、7、14、21和28天,行以下处理:收集24小时尿、血清样本检测大鼠24小时尿蛋白、血肌酐及血尿素氮含量;取肾组织经光镜、电镜观察肾组织病理变化;采用TUNEL法检测大鼠肾组织细胞凋亡情况;RT-PCR、免疫组织化学和Western blot法分别检测肾组织中IL-18、Fas mRNA和蛋白表达情况。结果:与正常对照组相比,肾炎模型组24小时尿蛋白、血肌酐和血尿素氮含量均明显升高(P<0.01);光镜和电镜观察到肾小球内可见新月体形成、GBM不规则增厚、足突融合等病变;肾小球内凋亡细胞于第2天开始轻度增加,随后继续增加,于第28天有所减少,但仍维持较高水平;血清IL-18含量第2天开始升高,此后一直维持较高水平;肾组织中IL-18、Fas mRNA和蛋白表达均显著增加(P<0.01);且肾炎模型组血清、肾组织IL-18表达与Fas表达均呈正相关(P<0.01)。结论:IL-18在大鼠抗GBM肾炎凋亡中发挥重要的促进作用。

Objective：To investigate the effect of interleukin-18 on apoptosis in anti-glomerular basement membrane nephritis by rats model.Methods：The rats were randomly divided into nephritis group and normal control group.The rats in nephritis group were preimmunized subcutaneously with normal rabbit serum 7 days before the injection of rabbit anti-rat GBM serum.The rats in normal control group were injected with normal rabbit serum and all the rats were observed for monitoring urinary protein in 24 h ,serum creatine,serum urea nitrogen at the 2nd day,the 7th day,the 14th day,the 21st day and the 28th day,respectively.At the same time,the kidney specimens were collected at intervals for the observation of the pathological changes.Apoptotic cells were determined by TUNEL assay.The mRNA and protein expression of IL-18 and Fas in renal tissues were detected by RT-PCR,immunohistochemistry methods and Western blot.Results：Compared with those in the control group,the 24 h urinary protein,serum creatine and serum urea nitrogen were obviously increased in the rats injected with rabbit anti-GBM serum（P0.01）.Glomerular hypercellularity,crescents and protein casts were observed in the nephritic rats.Glomerular fibrosis and cytoreduction were observed on the 21st day and the 28th day in the nephritic rats.The thickening of GBM,loss of epithelial foot processes,and foci of endothelial cell detachments were observed electronmicroscopically.In anti-GBM nephritis kidneys,glomerular apoptosis was significantly increased at all time points.The mRNA and protein expression of IL-18 and Fas was significantly increased in the model rats（P0.01）.A positive correlation existed between serum,nephridial tissue IL-18 and Fas in nephritic rats（P0.01）.Conclusion：IL-18 plays an important promotion in anti-glomerular basement membrane nephritis apoptosis.