Figure 5
The involvement of ERK and PI3K/Akt signal pathways in P. aeruginosa -induced IL-8 in SW480 cells. (A) Effect of ERK and PI3K inhibition on P. aeruginosa-induced IL-8 and hBD-2 secretion. SW480 cells were left untreated, or treated with 25 μM PD98059 (PD) and 50 μM LY294002 (LY) for one hour. They were then infected with the wild-type P. aeruginosa strain PAO1 for 7 hours. Supernatant was analyzed by ELISA for IL-8 and hBD-2. The amount of IL-8 and hBD-2 produced is shown as the fold increase over uninfected control (CON) cells. (B) Effect of ERK and PI3K inhibition on P. aeruginosa-induced IL-8 and hBD-2 mRNA. SW480 cells were left untreated, or treated with 25 μM PD98059 (PD) and 50 μM LY294002 (LY). They were then infected with the wild-type P. aeruginosa strain PAO1 for 7 hours. Total RNA was prepared and analyzed by real-time quantitative PCR to estimate amounts of IL-8 and hBD-2 transcript. The amount of IL-8 and hBD-2 mRNA produced, normalized to the corresponding amount of GAPDH transcript, is shown as the fold increase over uninfected control (CON) cells. Results are represented as means ± S.E.M. for at least three determinations from independent experiments. (* p <0.05; # p <0.005).