胰淀素诱导人肾小球系膜细胞凋亡

Amylin induces apoptosis of cultured human mesangial cells

目的 :研究胰淀素 (amylin)对人系膜细胞的毒性作用。 方法 :采用电镜、TUNEL、DNA凝胶电泳和碘化丙啶染色 (PI)流式细胞仪分析技术及免疫组化技术 ,观察amylin对人系膜细胞的作用。 结果 :光镜和电镜下见细胞体积缩小、染色质浓染、致密、边移和凋亡小体形成 ;TUNEL细胞染色阳性 ,DNA凝胶电泳出现DNA“梯形”片断 ;amylin处理 48h后 ,均可见亚二倍体细胞凋亡峰。定量分析示 :系膜细胞的凋亡数量与amylin浓度呈剂量依赖性 (P <0 0 1)。amylin治疗组和对照组乳酸脱氢酶活性细胞释放率无显著性差异 (P >0 0 5 )。 结论 :amylin对人系膜细胞具有细胞毒性作用 ,并可诱导系膜细胞的凋亡。

Objective:Beta cell apoptosis has been reported to be associated with the effects of locally deposited amylin.In this study,the effects of amylin on mesangial cell were explored in vitro with respect to the structural and histochemical characteristic of apoptosis process. Methodology:Primarily cultured human mesangial cell (MC) was applied and treated with fresh amylin preparation.MC was characterized under light microscope and positive staining with anti actin and desmin.Amylin treated MCs were observed and apoptotic cells determined by ultra structural changes,TUNEL,and DNA fragmentation analysis.Propidium iodide (PI) staining and flow cytometry was employed for quantitative measurement of apoptosis. Results:Under light and electron microscopy,mesangial cells with condensed chromatin,shrunken plasma,marginated nuclear chromatin or apoptotic body were observed in amylin treated MCs.TUNEL staining positivity,hypolipoid DNA peak,and typical DNA ladder pattern were also identified in amylin treated MCs.Quantitative analysis of apoptotic MCs showed that amylin did induce an increased apoptosis rate of human MCs in a dose dependent manner.Compared to the control,no significant changes of lactate dehydrogenase(LDH) release were observed in amylin treated MCs ( P >0 05). Conclusion:Amylin can induce apoptosis of human mesangial cells in vitro.Further study of amylin's effects on human MC might probe to the pathogenesis of hypocellularity and sclerosis in glomerulus of diabetic nephropathy.