Fig. 4

MEK/ERK is involved in CX3CL1-mediated MMP-3 production in OASFs. a OASFs were incubated with CX3CL1 for the indicated time intervals. MEK/ERK phosphorylation examined using western blot analysis. b OASFs were pretreated for 30 min with c-Raf inhibitor (GW5074) followed by stimulation with CX3CL1 for 15 min. MEK/ERK protein levels in the cell lysates determined using western blot analysis. c–e OASFs were pretreated for 30 min with MEK/ERK inhibitors (U0126 and PD98059) followed by stimulation with CX3CL1 for 24 h. MMP-3 expression examined using qPCR, western blot analysis, and ELISA. f, g OASFs were transfected for 24 h with MEK and ERK mutants followed by stimulation with CX3CL1 for 24 h. MMP-3 expression examined using qPCR and ELISA. Results expressed as mean ± SEM (n = 3). *p < 0.05 compared with control; #p < 0.05 compared with CX3CL1-treated group. MMP matrix metalloproteinase