Heme oxygenase-1 downregulates mucous hypersecretion induced by cigarette smoke in cultured A549 cells / 基础医学与临床

ABSTRACT

Objective To investigate the effects of heme oxygenase-1 (HO-1) on the signal transduction pathway of mucin(MUC) expression induced by cigarette smoke.Methods The cell model of mucous hypersecretion was made by human lung A549 cell stimulated by cigarette smoke extract(CSE),the cells were divided into 4 groupsnegative control group,CSE treatment group,heroin pre-treatment group and ZnPPIX pre-treatment group.The expression of MUC5AC,epidermal growth factor receptor(EGFR),p-EGFR,HO-1 and dual oxidase 1 (Duoxl) were detected.The cell activity was assessed by methyl thiazolyl tetrazolium method.The change of HO-1 mRNA,Duoxl mRNA,EGFR mRNA and MUC5AC mRNA was examined by reverse transcriptase-polymerase chain reaction.The protein expression of EGFR,p-EGFR,Duox1 and HO-1 was measured by Western blot,while the pro tein expression changes of MUC 5 AC were detected by ELISA.Results The expression level of MUC 5 AC mRNA and its protein in the CSE group increased significantly (P＜0.05) as compared to those in the control group [0.412±0.043,(105±8) μg/mg.The mRNA and protein of EGFR,Duox1 and HO-1,the protein of p-EGFR increased significantly as compared to the control group.After the cells being pre-treated with hemin,the mRNA and protein of HO-1 increased significantly,while the mRNA and protein of Duox1,EGFR and MUC,SAC,the protein of p-EGFR decreased significantly as compared to the CSE group.After the cells were pre-treated with ZnPPIX,the increase of HO-1 mRNA and protein was not significant as compared to the control group,while the mRNA and protein of Duox1,EGFR and MUCSAC,the protein of p-EGFR increased significantly.Conclusion HO-1 decreased the level of Duox1,blocked ligand-dependent EGF-R activation and decreased the expression levels of MUCSAC.