Increased inflammatory response in long-term CSE exposed BEAS-2B cells. Cells were exposed to 0% CSE, 2.5% CSE, 10% CSE 12.5% CSE as indicated for 6 months. A) IL-6, IL-1β mRNA expression (n = 5) and B) IL-8 mRNA expression was detected by qPCR and related to the housekeeping genes (n = 4). ΔCt values are shown (lower values reflect higher expression) and median interquartile ranges (IQR) are indicated. C) IL-8 protein levels were measured in cell-free culture supernatants (n = 4) and mean (±SEM) levels are shown. Significance is as indicated, * = p < 0.05, ** = p < 0.01, *** = p < 0.001.