Correlation between DNA methylation and Thymic Stromal Lymphopoietin expression in asthmatic airway epithelial cells

Background The overexpression ofTSLPand DNA methylation in asthma were both risk factors the relationship was not clear. Objective This study aimed to investigate the relationship between methylation status ofTSLPpromoter and mRNA/protein expression in asthmatic airway epithelial cells. Methods Human bronchial epithelial cells were cultured in vitro and divided into: Control group, treated with PBS, model group, sensitized with LPS (10 mu g/mL) for 12 h (37 degrees C, 5% CO2). Other groups were cultured with the pCMV3 plasmid (M + NC/pCMV), pGPH1 plasmid (M + NC/pGPH), DNMT1/pCMV3 plasmid (M + DNMT1/pCMV), and DNMT1/pGPH1 plasmid (M + DNMT1/pGPH) for 48 h. The expression of DNA methyltransferase 1 and TSLP were measured using real-time PCR and western blotting. Results Compared with the control group,TSLPmRNA (1.00 +/- 0.00 vs. 2.82 +/- 0.81 vs. 1, P < 0.001) and protein (1.07 +/- 0.04 vs. 1.46 +/- 0.11, P < 0.01) were significantly greater, and the methylation of promoter was lower (92.75 +/- 1.26 vs. 58.57 +/- 3.34, P < 0.05) in the model group. Compared with the model group,TSLPmRNA (2.82 +/- 0.81 vs. 1.17 +/- 0.10, P < 0.001) decreased, butTSLPpromoter methylation increased (58.57 +/- 3.34 vs. 92.58 +/- 7.30, P < 0.05) in M + DNMT1/pCMV.TSLPmRNA and protein were higher (2.82 +/- 0.81 vs. 5.32 +/- 0.21, P < 0.001; 1.46 +/- 0.11 vs. 1.94 +/- 0.11, respectively, P < 0.01),TSLPpromoter methylation was lower (58.57 +/- 3.34 vs. 33.57 +/- 4.29, P < 0.05) in M + DNMT1/pGPH. Conclusions Overexpression of TSLP in asthmatic airway epithelial cells may be regulated by DNA demethylation.