Fig. 3

c-Raf is involved in CXCL1-increased IL-6 expression in OASFs and RASFs. a, b OASFs and RASFs were pretreated with a c-Raf inhibitor (GW5047, 5 μM) for 1 h, then incubated with CXCL1 (10 ng/mL) for 24 h. IL-6 expression levels were quantified by qPCR and Western blot. The quantification of Western blot is provided in the lower panel. c OASFs and RASFs were incubated for different periods of time (control, 10, 15, 30, and 60 min). The cell lysates were collected, and phosphorylated c-Raf was determined by Western blot. The quantification of Western blot is provided in the lower panel. d OASFs and RASFs transfected with c-Raf shRNA were further incubated with CXCL1 (10 ng/mL) for 24 h, then IL-6 expression was examined by qPCR. (The knockdown efficiency was presented by Western blot). e OASFs and RASFs were pretreated with a CXCR2 inhibitor (SB225002, 5 μM) and examined for phosphorylation of c-Raf in the presence of CXCL1. The quantification of Western blot is provided in the lower panel. (In the above experiments, OASFs; n = 10, RASFs; n = 10). Results are expressed as the mean ± SEM. Statistical analysis was conducted by using one-way ANOVA followed by Fisher’s LSD post hoc comparisons tests. *p < 0.05 compared with the respective groups in all figures (control and untreated); ^#p < 0.05 compared to the groups with control (a, b, e) and control shR (d) pretreatment followed by CXCL1 incubation