Fig. 1

HB-EGF stimulates IL-8 production in BEAS-2B and HBECs. BEAS-2B cells and HBECs were continually stimulated with various concentrations of rhHB-EGF for 6 h (a and b) or stimulated with 100 ng/ml rhHB-EGF at the indicated time points (c and d). The cell culture supernatant wasn’t changed and samples was collected at the indicated time points. RT-PCR was conducted to detect the expression of IL-8 mRNA in BEAS-2B and HBE Cs. 6 h was selected based on the IL-8 mRNA expression with a maximum increase at a time point of 6 h (c and d). ELISA assay was conducted to detect the level of IL-8 secretion in BEAS-2B and HBECs (e–h). BEAS-2B cells were treated with various concentrations of rhHB-EGF for 6 h (e), and HBECs were treated with different concentrations of rhHB-EGF for 24 h (f). Both kinds of cells were cultured with 100 ng/ml rhHB-EGF at the indicated time points, with a maximum induction at 12 h in BEAS-2B and 24 h in HBECs (g and h). Data are from one experiment representative of three independent experiments. Results are expressed as mean ± SEM. ^#P < 0.05, ^##P < 0.01, ^###P < 0.001 versus control of BEAS-2B cells; *P < 0.05, **P < 0.01, ***P < 0.001 versus control of HBECs