Figure 1
Involvement of COX-2 in upregulating the expression of IL-1β, FGF-2 and MMP-1 in shear-activated human chondrocytes.
Human T/C-28a2 chondrocytes were subjected to fluid shear stress (20 dyn/cm2) or static conditions (0 dyn/cm2) for the indicated time intervals (a-d, a’-d’). In select experiments, T/C-28a2 chondrocytes were subjected to fluid shear stress (20 dyn/cm2) or static conditions (0 dyn/cm2) for 48 h in the absence or presence of the COX-2-specific inhibitor NS398 (10 μM) (c, d, c’, d’). mRNA levels of COX-2 (a,c) MMP-1 (b,d) IL-1β (a’, c’) or FGF-2 (a’, c’) were determined by qRT-PCR. The total amount of GAPDH served as internal control. Protein levels of COX-2 (a,c) or MMP-1 (b,d) were determined by western blots and the total amount of β-actin or MMP-11 served as internal control. The production of IL-1β (b’, d’) and FGF-2 (b’, d’) were determined by corresponding enzyme immunoassay kits. The total amount of proteins was used as internal control. The casein activity of MMP-1 was determined by zymography (b,d) The data represent the means ± S.E. of at least three independent experiments. *, p < 0.05 with respect to the static control. #, p < 0.05 compared with shear alone.
