Figure 1

Concentration- and time-dependent increases in IL-6 production by CCN4. (A) Human synovial fibroblasts (SFs) were obtained from normal (n = 3) or osteoarthritis patients (n = 3) and examined with western blotting for the expression of CCN4. (B, C) OASFs and normal SFs were incubated with various concentrations of CCN4 for 24 hours or with CCN4 (30 ng/ml) for 6, 12, or 24 hours. Media were collected to measure IL-6 production (n = 4). (D, E) OASFs and normal SFs were incubated with various concentrations of CCN4 for 24 hours or with CCN4 (30 ng/ml) for 6, 12, or 24 hours. The mRNA expression of IL-6 was examined by qPCR (n = 4). (F) OASFs and normal SFs were incubated with various concentrations of CCN4 for 24 hours, and the protein expression of IL-6 was examined by Western blot (n = 3). (G) OASFs were pretreated with polymyxin B (poly B, 1 μM) for 30 minutes followed by stimulation with CCN4 (30 ng/ml), and IL-6 expression was examined by qPCR (n = 3). (H) OASFs were incubated with of CCN4 (30 ng/ml), and the mRNA expression was examined by qPCR (n = 3). Results are expressed as the mean ± SEM. *, P <0.05 compared with control; #, P <0.05 compared with CCN4-treated group. OASFs, osteoarthritis synovial fibroblasts; SEM, standard error of the mean.