醋酸铅对PC12细胞核转录因子-κB转录活性的影响

Effects of lead acetate on transcription activity of nuclear factor-κB in PC12 cells

目的探讨醋酸铅及NF-κB抑制剂吡咯烷二硫氨基甲酸(PDTC)对核转录因子-kappaB(NF-κB)转录活性的影响。方法将大鼠肾上腺嗜铬细胞瘤细胞(PC12细胞)暴露于不同浓度的醋酸铅0、12.5、25、50、100、200、400、800和1600μmol/L,采用四唑盐比色实验(MTT)检测IC50值。用脂质体将pNF-κB-Luc报告基因质粒转染入PC12细胞,转染后的PC12细胞分别暴露于不同浓度的醋酸铅(100、200和400μmol/L)及不同浓度醋酸铅加PDTC100μmol/L,24小时后采用萤光素酶检测试剂盒检测萤光素酶活性。结果用不同浓度的醋酸铅处理细胞24小时,其生长增殖受到不同程度的抑制,且呈现出剂量-反应关系,其IC50值为(533.966±100.830)μmol/L。用不同浓度的醋酸铅处理转染后的PC12细胞24小时,结果显示:PDTC对照组萤光素酶活性较空白对照组降低(P<0.01);铅处理组萤光素酶活性较空白对照组高(P<0.01),且具有剂量依赖性;铅+PDTC联合作用组与PDTC对照组相比,PC12细胞内萤光素酶活性增高(P<0.01)。结论醋酸铅可诱导PC12细胞的NF-κB转录活性升高。

Objective To investigate the effects of lead acetate and inhibitor of-κB （NF-κB）, PDTC, on the transcription activity of NF-κB in PC12 cells. Methods PC12 cells were exposed to 0μmol/L, 12.Sμmol/L, 25μmol/L, 50μmol/L, 100μmol/L, 200μmol/L, 400μmol/L, 800μmol/L and 1600μmol/L lead acetate for 24 hours. The IC50 value was measured by MTT assay. The pNF-κB-Luc reporter gene plasmid was transfected into PC12 cells by cationic liposome, and then the cells were exposed to 100μmol/L,200μmol/L and 400μmol/L lead acetate and different concentrations of lead acetate plus 100umol/L PDTC, respectively. The luciferase activities of the reporter gene were measured by luciferase assay kit after 24 hours exposure to lead acetate. Results The PC12 cells were exposed to lead acetate at varied concentrations for 24 hours, and the growth and proliferation of the cells are inhibited with various degrees, showing a dose-effect relationship. The IC50 was detected to be （533.966 ± 100.830） μmol/L. The results showed that luciferase activity of PDTC control groups is lower than that of blank control group （P 〈 0.01） 24 hours after lead acetate exposure. It is also found that the luciferase activity of groups treated with lead acetate are higher than that of blank control group（ P 〈 0.01） with a dose-effect relationship. Significantly higher luciferase activity are found in the groups treated with lead acetate and PDTC compared with the PDTC control group（ P 〈 0.01 ）. Conclusion Lead treatment to PC12 cell results in activation of NF-κB.