无机砷对红系相关因子-2及其抑制因子mRNA表达的影响

Effects of inorganic arsenic on mRNA expression of Nrf2 and Keap1

目的观察亚砷酸钠(NaAsO2,sodium arsenite)对Chang肝细胞株核转录因子红系相关因子(nuclear factor ery-throid 2-related factor 2,Nrf2)及其胞浆抑制因子Keap1(Kelch-like ECH-associated protein 1)的mRNA表达水平的影响。方法分别以不同浓度NaAsO2(0、50、200、400μmol/L)暴露人类Chang肝细胞株12 h,采用AlamarBlue法测定细胞增殖活性,采用RT-PCR法测定Nrf2和Keap1的mRNA表达水平。结果 50μmol/L NaAsO2暴露组的细胞增殖活性与对照组相比差异无统计学意义(P>0.05),而200μmol/L和400μmol/L NaAsO2暴露组的细胞增殖活性均显著低于对照组(P<0.05);50、200、400μmol/L的NaAsO2暴露12 h,Nrf2和Keap1的mRNA表达水平与对照组比较均显著下降(P<0.05),且呈剂量-反应关系。结论高浓度无机砷暴露能抑制Chang肝细胞株Nrf2和Keap1的mRNA表达水平,并可能与无机砷造成机体的高氧化应激水平有关。

Objective To study the effects of inorganic arsenic on mRNA expression of transcription factor Nrf2 and its cytoplastic inhibitor Keap1 in Chang hepatocytes.Methods Chang hepatocytes were treated with 0,50,200 and 400 μmol/L of sodium arsenite（NaAsO2） for 12 h,and AlamarBlue assay and RT-PCR were then performed to detect the cell viability and the mRNA expression of Nrf2 and Keap1.Results Cell viability in 50 μmol/L of NaAsO2 was almost the same as that in control（P0.05）,while the viability in the other two groups were significantly lower than that in control（P0.05）.Nrf2 and Keap1 mRNA expression in the three groups were all significantly reduced by sodium arsenite exposure,and a definite dose-effect relationship was confirmed（P0.05）.Conclusion High levels of inorganic exposure could inhibit the mRNA expression of Nrf2 and Keap1 in human hepatocytes,which may be related to the arsenic induced oxidative stress.