Fig. 5

Matrilin-3 was involved in the effects of miR-448 on IL-1β-induced cartilage degradation in chondrocytes. Chondrocytes were transfected with either miR-448 inhibitor or si-matrilin-3, and then treated with 5 ng/ml IL-1β for 24 h. a, b The mRNA and protein levels of matrilin-3 were respectively determined using quantitative real-time PCR and western blot. The mRNA levels of aggrecan (c) and type II collagen (d) were determined using quantitative real-time PCR. GAPDH was detected as a loading control. e The expression level of secreted MMP-13 protein was determined by ELISA. All data are presented as means ± SEM, n = 4. **p < 0.01, ***p < 0.001 vs. control; ^#p < 0.05, ^##p < 0.01 vs. vehicle + IL-1β; ^&p < 0.05 vs. IL-1β + miR-448 inhibitor