RESUMO
Objective:To investigate the effects of different concentrations of hydrogen peroxide (H 2O 2) on the expression of histone deacetylase-2(HDAC-2) and mitogen activated protein kinases phosphatases-1(MKP-1) in A549 cells. Methods:The experimental models of A549 cells were established by intervening of different concentrations of H 2O 2(0, 100, 200, 400, 600, 800 μmol/L)for 2 h, 4 h, 8 h, 12 h and 24 h, respectively.The survival rate of A549 cells was detected by thiazolyl blue(MTT) assay, and the apoptosis of A549 cells was tested by lactic dehydrogenase(LDH) assay.The expression of HDAC-2 and MKP-1 protein was detected by Western blot. Results:(1)MTT results showed that compared with the control group (H 2O 2 was 0 μmol/L), the survival rate of A549 cells was decreased with the increase of H 2O 2 concentration at 2 h, 4 h, 8 h, 12 h, 24 h and 48 h. (2)LDH results showed that, compared with the control group, the inhibition rate of A549 cells increased with the increase of H 2O 2 concentration at 2 h, 4 h, 8 h, 12 h, 24 h and 48 h. (3)The expression of HDAC-2 protein decreased ( F=14.588, P<0.01), and the expression of MKP-1 protein increased ( F=64.297, P<0.01) in a concentration-dependent manner with the increase of H 2O 2 concentration at 12 h after H 2O 2 treatment. Conclusions:H 2O 2 participates in oxidative stress injury of lung cells by regulating the expression of HDAC-2 and MKP-1.