Fig. 4
EP2/EP3 and FPR mediated the effects of PGE2 and PGF2α on stimulating the expression of MMP-12 in shear-activated human T/C-28a2 chondrocytes. a–f T/C-28a2 chondrocytes were subjected to fluid shear stress (20 dyn/cm2) or static conditions (0 dyn/cm2) in the absence or presence of AH6809 (3 μM) or sulprostone (1 μM) for 6 h. g–i In select experiments, T/C-28a2 chondrocytes were treated with the indicated concentrations of exogenous PGF2α (10 μM) in the absence or presence of FPR siRNA for 48 h. a, d, g MMP-12 mRNA and protein levels were determined by qRT-PCR and western blots, respectively. GAPDH and MMP-11 served as internal controls in qRT-PCR and western blots, respectively. b, c, e, f, h, i The mRNA and protein expression of IGF-2 were determined using qRT-PCR and an enzyme immunoassay kit, respectively. GAPDH and total protein in the medium served as internal controls in qRT-PCR and enzyme immunoassay, respectively. Data represent the mean ± SE of at least three independent experiments. *p < 0.05 with respect to static or vehicle-treated controls. # p < 0.05 with respect to shear stress or PGF2α treatment
