miR-320a overexpression enhanced IL-1β-induced matrix degradation by targeting PBX3. C28/I2 cells were transfected with miR-320a and/or PBX3 vector and then stimulated with IL-1β. mRNA level expressions of (a) Col2α1 and (b) ACAN were determined by RT-PCR. The concentrations of (c) sGAG and (d) MMP-13 were measured by Blyscan sGAG Assay Kit and MMP-13 ELISA kit, respectively. *, p < 0.05; **, p < 0.01. Statistical analysis was performed using two-tailed paired t-test.