活性氧在硒致HepG2 DNA损伤中的作用

目的探讨亚硒酸钠(Na2SeO3)致HepG2细胞DNA损伤的作用机制。方法用0、2·5、5、10、20μmol/L的Na2SeO3、及分别加有还原性谷胱甘肽(GSH)和N-乙酰基-L-半胱氨酸(NAC)的Na2SeO3(10μmol/L)处理HepG2。用四甲基偶氮唑盐(MTT)比色法测定细胞活性;流式细胞仪测细胞内活性氧(ROS)的水平以及用彗星实验检测细胞的DNA损伤。结果5、10、20μmol/L Na2SeO3作用于HepG21h即引起ROS增加,12h后即导致细胞HepG2活性下降,24h后DNA损伤增强,与对照组相比,差异有统计学意义(P<0·05);抗氧化剂GSH和NAC有效抑制了ROS升高,并增强了细胞活性,减弱了细胞DNA损伤,与未加GSH和NAC的Na2SeO3组(10μmol/L)相比,差异有统计学意义(P<0·05)。结论ROS的产生可能是亚硒酸钠造成HepG2DNA损伤的重要原因。

Role of reactive oxygen species in sodium selenite induced DNA damage in HepG2 cells

OBJECTIVE: To investigate the mechanisms of sodium selenite induced DNA damage in HepG2 cells. METHODS: HepG2 cells were treated with the designed concentrations of sodium selenite and the selenite (10 micromol/L) added simultaneously with GSH (10 mmol) and NAC (5 mmol). Then the cell viability was detected by MTT, and the flurescent intensity of reactive oxygen species (ROS) was determined by flow cytometry, and DNA damage was detected by commet assay. RESULTS: The level of ROS was increased after HepG2 was treated with 5, 10, 20 micromol/L sodium selenite for one hour, and the cell viability was decreased after 12 hours, and the DNA damage was enhanced. Compared with the control group, the difference was statistically significant (P < 0.05) . GSH and NAC effectively inhibited the ROS increased and cell viability decreased and DNA damage weakened. CONCLUSION: ROS may be the important reason that sodium selenite induced HepG2 cells DNA damage.