雷公藤内酯醇抑制肾缺血再灌注大鼠肾小管上皮细胞凋亡的机制研究

Mechanism of Triptolide Inhibits Renal Tubular Epithelial Cell Apoptosis in Renal Ischemia Reperfusion Rat

目的探讨雷公藤内酯醇(triptolide,TP)对肾缺血再灌注损伤(ischemia-reperfusion injury,IRI)大鼠的肾保护作用,及对JNK信号通路的影响。方法 90只Wistar大鼠,♂,随机分为假手术组,IRI模型组(IRI组),TP高、中、低剂量干预组,泼尼松对照组(Pred组)。采用夹闭双侧肾动脉30 min,再灌注18 h的方法制作肾IRI大鼠模型。检测血肌酐(Scr)、尿素氮(BUN),原位末端标记法检测肾小管上皮细胞凋亡,并观察肾病理改变。Western blot和RT-PCR分别检测JNK、c-Jun蛋白和基因表达。结果 IRI组大鼠血Scr、BUN及细胞凋亡指数较假手术组显著升高(P<0.01);与IRI组比较,TP各组及Pred组以上指标均得到改善(P<0.01),其中TP各组细胞凋亡指数改善优于Pred组。IRI组大鼠肾组织JNK、c-Jun较假手术组高表达(P<0.01);与IRI组比较,TP各组二者表达均减弱(P<0.01),Pred组二者表达无差异。结论 TP通过抑制肾IRI大鼠肾小管上皮细胞凋亡,减轻肾小管损伤,其机制可能与抑制JNK信号通路的激活有关。

OBJECTIVE To explore the renal protection of triptolide（TP） on renal ischemia-reperfusion injury（IRI） model, and explore it＇s effect on JNK signaling pathways. METHODS Ninety male Wistar rats were randomly divided into sham operation group, IRI model group（IRI group）, TP intervention groups（high, medium and low dose group） and prednisone group（Pred group）. Renal IRI model was made by clipping bilateral renal artery for 30 min, then 18 h reperfusion. Serum creatinine（Scr）, urea nitrogen（BUN）, renal pathological changes were observed. And renal tubular epithelial cell apoptosis was detected by TUNEL method. JNK, c-Jun protein and gene expressions were detected by Western blot and RT-PCR respectively. RESULTSCompared with sham operation group, the Scr, BUN, and cell apoptosis index in the IRI group were significantly increased（P〈0.01）. Above indexes were improved in each TP group and Pred group as compared with the IRI group（P〈0.01）. And the cell apoptosis index in each TP group was better than that in Pred group. The expression of JNK, c-Jun were higher in IRI group than those in the sham operation group（P〈0.01）. Compared with the IRI group, the expression of JNK and c-Jun in the TP group was weakened（P〈0.01）, and there was no difference in the expression of the Pred group. CONCLUSION TP reduces renal tubular injury by inhibiting renal tubular epithelial cell apoptosis, which may be related to inhibit the activation of the JNK signaling pathway.