氧化应激条件下G6PD对Raji细胞内GSH水平的影响

EFFECT OF GLUCOSE-6-PHOSPHATE DEHYDROGENASE ON INTRACELLULAR GSH LEVEL IN RAJI CELLS DURING OXIDATIVE STRESS

目的:观察体外培养的Burkit淋巴瘤(Raji)细胞在氧化应激条件下细胞内葡萄糖-6-磷酸脱氢酶(G6PD)对还原型谷胱甘肽(GSH)水平的影响。方法:体外培养Raji细胞,分别在G6PD活性被抑制及不抑制的情况下,检测细胞在酚嗪甲酸硫酯(PMS)作用后60min及360min时G6PD、谷胱甘肽还原酶(GR)、谷胱甘肽过氧化物酶(GPx)活性及GSH水平。结果:在PMS作用下,Raji细胞内GSH水平在60min时显著下降(P<0.01)而360min时可上升至对照组水平,G6PD及GPx活性持续显著升高(P<0.01)而GR活性在360min时有显著升高(P<0.01);使用脱氢表雄酮(DHEA)抑制G6PD活性后,Raji细胞再在PMS作用下,细胞内各指标与PMS处理组比较,GSH水平显著降低(P<0.01),GPx活性在60min时显著增高(P<0.05)而GR活性在360min时显著降低(P<0.01)。结论:细胞在氧化应激条件下G6PD可能是Raji细胞内影响GSH水平的一个关键因子,对维持胞内GSH水平起重要的调节作用。

To explore a role of G6PD in replenishment of intracellular GSH during oxidative stress. Methods： In vitro Raji cell was cultured, intracellular GSH levels and G6PD,GR,GPX activities were determined at different time points after PMS treatment when G6PD activity was inhibited or not by DHEA. Results： Intracellular GR,GPX,G6PD activities elevated significantly combined with GSH level decreased dramatically before 30 minutes, replenished gradually after 30 minutes and restore normal levels about 6 h after PMS treatment when G6PD was not inhibited. No change in GR and significant increase in GPX activity were shown following depleted GSH after PMS treatment when G6PD was inhibited by DHEA. Conclusion： G6PD contributes to replenish intracellular GSH and is a critical factor regulating GSH levels during oxidative stress.