Disc annulus fibrosus cells were treated with 2 ng/ml IL-1β or (and) with 40 ng/ml HMGB1 for 12 h, then the relative mRNA levels of MMP-1 (A), -3 (A), -9 (B) or TIMP metallopeptidase inhibitor 1 (TIMP-1) (B) to Glyceraldehyde 3-phosphate dehydrogenase (GAPDH) were examined with real-time quantitative PCR (RT-qPCR) method; (C) western blotting assay for MMP-1, -3, -9 and TIMP-1 in protein levels in the IL-1β- or (and) HMGB1-treated disc annulus fibrosus cells. Results are presented as mean ± S.E.M. for quartic independent experiments. Parametric ANOVA (Tukey–Kramer post hoc) test was performed for statistical significance analysis. *P<0.05, **P<0.01 or ns: no significance.