Fig. 1

Concentration-dependent and time-dependent increases in MMP-3 production by CX3CL1. a Human SFs were obtained from healthy patients (n = 8) or patients with OA (n = 10). CX3CL1 expression examined using qPCR. b, c OASFs and normal SFs were incubated with CX3CL1 (50 ng/ml) for 24 h. mRNA expression of MMPs examined using qPCR (n = 4). d, g OASFs and normal SFs were incubated with various concentrations of CX3CL1 for 24 h or with CX3CL1 (50 ng/ml) for 6, 12, or 24 h. mRNA expression of MMP-3 examined using qPCR (n = 4). e, h OASFs and normal SFs were incubated with various concentrations of CX3CL1 for 24 h or with CX3CL1 (50 ng/ml) for 6, 12, or 24 h; supernatants and cell lysates were then collected. MMP-3 level in culture media measured using a Quantikine ELISA kit (n = 4). f, i MMP-3 protein levels in cell lysates determined using western blot analysis. Both protein levels and enzymatic activity increased in a dose-dependent and time-dependent manner. Results expressed as mean ± SEM. * represents P < 0.05, ** represents P < 0.01, ***represents P < 0.001, as compared to respective control by using one-way ANOVA followed by Bonferroni's post-hoc test.. MMP matrix metalloproteinase, OASF osteoarthritis synovial fibroblast