Influence of low level, long-term arsenite exposure on HaCat cell apoptosis and the expression of Bcl-2 and Bax proteins

Objective To investigate the influence of low-dose,long-term arsenite exposure on keratinocyte (HaCat) cell apoptosis and the expression of Bcl-2 and Bax proteins.Methods HaCat cells were exposed to different concentrations of NaAsO2[0(control group),0.05,0.10 μmol/L] for 15 weeks.A total of 10 000 cells in each group were measured to detect the level of apoptosis by flow cytometry.The protein expressions of Bcl-2 and Bax were determined by Western blotting method.Results The cell apoptosis rate was significantly different between groups (F =17.19,P ＜ 0.05).Compared with that of the control [(1.42 ± 0.13)％],the apoptosis rates of the 0.05 and 0.10 μmol/L groups [(1.23 ± 0.08)％ and (1.04 ± 0.06)％] decreased significantly (all P ＜ 0.05); the 0.10 μmol/L group was significantly lower than that of the 0.05 μmol/L group(P ＜ 0.05).The protein expressions of Bcl-2 and Bax were significantly different between groups (F=107.38,346.45,all P＜ 0.05).The protein expression of Bcl-2 of the 0.05 and 0.10 μmol/L groups were (143.89 ± 7.74)％ and (199.96 ± 12.18)％,respectively,which were significantly higher than that of the control group[(100.00 ± 1.45)％,all P ＜ 0.05] ; the 0.10 μmol/L group was significantly higher than that of the 0.05 μmol/L group (P ＜ 0.05).The protein expression of Bax of the 0.05 and 0.10 μmol/L groups were (70.78 ± 1.53)％ and (54.80 ± 1.34)％,respectively,which were markedly lower than that of the control group[(100.00 ± 3.09)％,all P ＜ 0.05]; the 0.10 μmoL/L group was significantly lower than that of the 0.05 μmol/L group(P ＜ 0.05).Conclusion Decreased level of apoptosis induced by low level and long-term arsenic exposure may be associated with increased expression of Bcl-2 protein and decreased expression of Bax protein. Key words: Sodium arsenite;  HaCat cell;  Apoptosis ;  Genes, Bcl-2 ;  Bax protein