Objective To observe the effects of inorganic arsenic on mRNA and protein expression of heme oxygenase-1(HO-1) in Chang hepatocytes.
Methods Sodium arsenite (NaASO2,5 and 10μmol/L) were given to the Chang hepatocytes for 2,6,12 and 24 h,then reverse transcriptase-polymerase chain reaction (RT-PCR) and Western Blot were used to evaluate the expression of HO-1 mRNA and protein.
Results The 5 and 10 μmol/L NaASO2 induced HO-1 mRNA expression after 2 h.The expression increased notably at 6 h (P<0.01).The 10 μmol/L NaASO2-induced HO-1 mRNA expression was significantly higher at both 12 h and 24h than at 6h exposure (P<0.01).Even at 24h,the HO-1 mRNA expression level was still at a steady value similar to that of 12h.In contrast,the 5 μmol/L and 10 μmol/L NaASO2 induced HO-1 protein expression could be observed from 6 h (2.80 and 3.97 folds to the control),continued to increase at 12 h (9.34 and 12.92 folds),and further up-regulated at 24 h (18.15 and 23.29 folds)(P<0.01).Furthermore,the 10 μmol/L NaASO2 treatment induced a remarkably higher HO-1 mRNA and protein expression than the 5 μmol/L exposure at the corresponding exposure times (P<0.01) of 12 h and 24 h.
Conclusion NaASO2 can induce a strong and sustained HO-1 mRNA and protein expression in Chang hepatocytes,which suggest to be protective adaptive changes of hepatocytes in response to inorganic arsenic exposure.