Fig. 2
Involvement of PGE2 and PGF2α in upregulating the expression of MMP-12 in shear-activated human chondrocytes. T/C-28a2 chondrocytes were treated with the indicated concentrations of exogenous PGE2 (10 μM) (a) or PGF2α (10 μM) (b) for 48 h. In select experiments, T/C-28a2 chondrocytes were transfected with a siRNA specific target mPGES-1 (c, e, g) or PGFS (d, f, h) before subjecting to fluid shear stress (20 dyn/cm2) or static conditions (0 dyn/cm2). a, b, g, h 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. c and d mPGES-1 or PGFS expression levels were determined by qRT-PCR and western blots, respectively. GAPDH and β-actin served as internal controls in qRT-PCR and western blots, respectively. e and f The secretions of PGE2 and PGF2α were determined using enzyme immunoassay kits. Total protein in the medium served as an internal control in enzyme immunoassays. Data represent the mean ± S.E. of at least three independent experiments. *p < 0.05 with respect to static control. # p < 0.05 with respect to shear stress treatment
