Figure 5

TLR3 is overexpressed in primary bronchial epithelial cells from current smokers and COPD patients and downregulated by roflumilast N-oxide. (A) Human bronchial epithelial cells (HBECs) from non-smokers (n = 15), smokers (n = 12), and COPD patients (n = 15) were isolated from lung tissues. (A) mRNA expression of TLR3 in HBECs from different patients was determined by real time PCR as the ratio to GAPDH. (B, C, D) HBECs from different patients were incubated in the presence or absence of roflumilast N-oxide (RNO) or dexamethasone (DEX) for 1 hour and stimulated with TLR3 agonist poly I:C for 24 hours. Results are expressed as means ± SEM of n = 4–5 (4 non-smokers, 4 smokers, and 5 COPD patients) run in triplicate. Two-way repeated measures analysis of variance (ANOVA) were performed. Post hoc Bonferroni test: *P < 0.05 compared with non-smoker group or with solvent controls. #P < 0.05 compared with poly I:C stimulus.