Fig. 5

Muc1 KO mice is resistant to the anti-inflammatory effects of dexamethasone in a model of acute cigarette smoke inflammation. C57BL/6 Muc1 KO mice and WT mice were undergoing intranasal instillation of 75 μg of lipopolysaccharide (LPS) at day 1. Between days 2 and 3, animals were exposed to cigarette smoke (or control air) of 6 cigarettes followed by 8 cigarettes (or control air) at days 4 and 5, and 10 cigarettes (or control air) at day 6. Vehicle or dexamethasone at 3 mg/kg/day and 10 mg/kg/day was administered orally once a day between day 1 and 6. Animals were sacrificed at day 6 and lungs were homogenized to analyze the gene mRNA expression of (a) IL-8, (b) IL-13, (c) Muc1 and (d) GRα. Gene expression was analyzed by real time PCR using the 2^-ΔCt as described in methods. Results are the mean ± SE of n = 8 animals per experimental group. One-way ANOVA followed by Bonferroni post-hoc tests. *P < 0.05 compared with control. #P < 0.05 compared with LPS. ┴P < 0.05 compared with WT. KO: knock out; WT: wild type; CS: cigarette smoke; LPS: lipopolysaccharide