JNK信号传导通路在赭曲毒素A体外诱导人肾小管上皮细胞凋亡中的作用

Role of JNK signal transduction pathway on apoptosis of human kidney tubular epithelial cells induced by ochratoxin A in vitro

目的探讨赭曲毒素A(OA)诱导人肾小管上皮细胞(HKC)凋亡的作用机制。方法体外培养HKC,随机分为空白对照组、溶剂(0.04%乙醇)对照组、OA 1μmol·L-1处理组及c-Jun氨基端激酶(JNK)阻断剂SP600125 0.5μmol·L-1预处理+OA组。细胞处理24h后,分别采用流式细胞仪检测细胞的凋亡率,免疫细胞化学染色和Western蛋白印迹法检测凋亡相关蛋白天冬氨酸半胱氨酸蛋白酶(caspase)3蛋白的表达以及JNK的磷酸化水平(p-JNK)。结果OA组细胞凋亡率明显高于溶剂对照组〔(4.24±0.17)%vs(1.06±0.14)%〕,SP600125预处理+OA组HKC凋亡率〔(2.44±0.38)%〕明显低于OA组。OA组caspase 3蛋白的表达和p-JNK水平明显升高,SP600125预处理+OA组caspase 3蛋白的表达和p-JNK水平较OA组明显降低。结论OA可能通过激活JNK,上调caspase 3蛋白的表达而诱导HKC凋亡。

AIM To explore the role of c-Jun NH2 terminal kinase （JNK） singnal transduction pathway on ochratoxin A （OA） inducing apoptosis of human kidney tubular epithelial cells （ HKC ） in vitro. METHODS HKC were incubated with saline, solvent （0.04% ethanol）1μmol·L^-1 OA and JNK inhibitor SP600125 （0.5 μmol·L^-1） ± OA, respectively, for 24 h. The apoptosis rate, the expression of caspase 3 and level of p-JNK of HKC were detected by flow cytometry, immunocytochemical staining and Western blot, respectively. RESULTS After OA treatment, the apoptosis rate was higher than that in solvent group [（4.24±0.17）% vs （1.06 ±0. 14）%]. Pretreatment with SP600125 for 30 min decreased the apoptosis rate （2.44_±0.38） % ].The expressions of caspase 3 and level of p-JNK in OA group were higher than that in solvent group, while both were lower in SP600125 ± OA group than that in OA group. CONCLUSION The possible mechanism of apoptosis of HKC after OA treatment may be related with the activation of JNK and increasing the expression of caspase 3.