Figure 4. Effect of HA_oligos on MMP-3 expression. TMJ chondrocytes exhibit dose-dependent (A) and time-course-dependent (B) effects of HA_oligos on MMP-3 mRNA. Shown are calculated ratios of the treated samples (black bars) to untreated controls (white bars). Caseinolytic activity in the conditioned medium of TMJ chondrocytes treated for 24 hrs with increasing concentrations of HA_oligos (C) or ± 250 µg/mL HA_oligos for 12 or 24 hrs (D) was assessed by casein zymography. Panel E illustrates the reversibility of these HA_oligos effects following wash-out of HA_oligos or wash-out in the presence of HMW-HA. Real-time PCR was performed, and changes in MMP-3 mRNA expression are depicted as fold-increase ratios of treated samples to untreated controls. Data represent the mean ± SD of three experiments. *p < 0.05; **p < 0.01.