Figure 7

BEAS2B bronchial epithelial cells exposed to cigarette smoke and stimulated with TLR3 agonist release IL-8 secretion that is inhibited by roflumilast N-oxide but not by dexamethasone. BEAS2B cells were pretreated (A, B) without or (A, C) with cigarette smoke extract (CSE) 1% for 1 h followed by the incubation in the presence or absence of different concentrations of roflumilast N-oxide (RNO) or dexamethasone (DEX) for 1 h. After drug incubation cells were stimulated with the TLR3 agonist poly I:C for 24 h and IL-8 release was measured by ELISA. Each graph represents the mean ± SEM of 3–4 independent experiments. One-way repeated measures analysis of variance (ANOVA) were performed. Post hoc Bonferroni test: *P < 0.05 compared with cells exposed to air; #P < 0.05 compared with monotherapy.