目的：探讨细胞凋亡和细胞自噬在慢性环孢素A （ CsA）肾毒性中的作用。方法 Sprague-Dawley大鼠分为两组：对照组：皮下注射橄榄油（1 ml· kg-1· d-1）4 w；慢性CsA肾毒性组：皮下注射CsA （15 mg· kg-1· d-1）4 w。检测两组大鼠的体重和肾功能；三色染色检测肾小管间质纤维化程度；ELISA法检测血、尿8羟基脱氧鸟苷（8-OHdG）水平；原位末端标记法（ TUNEL）染色观察细胞凋亡；免疫印迹法检测细胞凋亡调控基因（ Bcl-2、Bax、Caspase-3）和细胞自噬体膜型LC3-Ⅱ蛋白的表达；Pearson 直线相关分析肾小管间质纤维化程度与细胞凋亡和LC3-Ⅱ蛋白表达的相关关系。结果与对照组相比，毒性组大鼠体重减轻、肾功能低下、血尿8-OHdG水平升高，同时肾毒性组可见明显的肾小管间质纤维化和大量TUNEL阳性细胞。免疫印迹结果表明，毒性组 Bax、Caspase-3、LC3-Ⅱ蛋白的表达明显增加，反之，Bcl-2的表达显著减少。直线相关分析提示，肾小管间质纤维化程度与TUNEL阳性细胞数和 LC3-Ⅱ蛋白表达呈正向相关。结论细胞凋亡和细胞自噬参与了慢性CsA肾毒性肾小管间质的损伤。%Objective To examine whether apoptosis and autophagy were involved in the pathogenesis of chronic cyclosporine A (CsA) nephrotoxicity.Methods Sprague-Dawley rats kept on a low salt diet (0.05%sodium) were treated daily for four weeks with subcu-taneous injections of vehicle (olive oil, 1 ml/kg) or CsA (15 mg/kg).Body weight and renal function were monitored .In addition, renal tubulointerstitial fibrosis , oxidative stress ( 8-OHdG ) , apoptotic cell death ( TUNEL assay ) , and expressions of apoptosis-related genes (Bcl-2, Bax, and Caspase-3) and LC3-Ⅱ (autophagy) were also measured.Results Compared with the normal treated rats, rats given CsA showed loss of body weight and renal dysfunction , with the development of striped tubulointerstitial fibrosis and increased TUNEL-posi-tive cells.CsA treatment significantly upregulated Bax , Caspase-3, and LC3-II expressions compared with those of vehicle group , whereas Bcl-2 protein expression was downregulated .These changes were accompanied by increase in serum and urinary 8-OHdG levels.Moreover, tubulointerstitial fibrosis was closely associated with the number of TUNEL-positive cells and LC3-II protein expression .Conclusions Apop-tosis and autophagy might be one of the molecular mechanisms in the tubulointerstitial fibrosis of chronic CsA nephrotoxicity .
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