ABSTRACT
Objective To explore the antioxidant mechanism ofhistone deacetylase 2 (HDAC2) regulating Nrf 2 acetylation in lipopolysaccharide (LPS)-induced type Ⅱ alveolar epithelial cell injury.Methods The experiment was divided into two parts.The first part was the routine culture of type Ⅱ alveolar epithelial cells of mice.The cells were stimulated with different concentrations of LPS (10 ng/ mL,100 ng/mL and 1 000 ng/mL).CCK-8 was used to detect the cell activity at 0 h,6 h,12 h,24 h and 48 h,respectively.The second part:Alveolar epithelial cells of type Ⅱ were cultured and divided into the normal control group (control group),LPS group,HDAC2 lentivirus interference group (siRNA-HDAC2 group) and HDAC2 lentivirus overexpression group (LV-HDAC2 group).The expression of HDAC2 and Nrf2 were detected by Western blot,the acetylation of Nrf2 was detected by immunoprecipitation,and the stability of nrf2 was detected after actinidone action.The activity of superoxide dismutase (SOD) and malondialdehyde (MDA) were detected by chemical colorimetry.SPSS 23.0 statistical software was used.LSD-t test was used for comparison between two groups,and one-way ANOVA test was used for comparison among multiple groups.Results Compared with the control group,the expression of HDAC2 protein in the LPS group increased (t=5.974,P=0.027),the acetylation level of Nrf2 decreased (t=7.223,P=0.002),the Nrf2 protein level increased (t=2.929,P=0.043),the protein stability of Nrf2 increased,the SOD activity decreased (t=121,P＜0.01),and the MDA content increased (t=10.45,P=0.000 5).Compared with the LPS group,Nrf2 acetylation level decreased in the LV-HDAC2 group (t=1 1.29,P=0.000 4),Nrf2 protein expression increased (t=3.194,P=0.033),Nrf2 protein stability increased,SOD activity increased (t=4.678,P=0.009),and MDA content decreased in the LV-HDAC2 group (t=5.417,P=0.005 6).While the opposite trend was observed in the siRNA-HDAC2 group.Conclusion After LPS stimulation,oxidative stress of type Ⅱ alveolar epithelial cells was aggravated.HDAC2 could decrease the level of Nrf2 acetylation,increase the expression of Nrf2 protein,and alleviate LPS-induced oxidative stress.