Fig. 4

MMP-13 expression in chondrocytes after ACL injury. a Quantitative MMP-13 mRNA expression in cultured normal chondrocytes and chondrocytes from patients with ACL rupture. GAPDH was used for normalization of the real-time PCR data. (Error bars = standard errors, * p < 0.05). b and c Representative western blot of MMP-13 protein expression in cultured normal chondrocytes and chondrocytes from patients with ACL rupture and a bar graph showing relative MMP-13 protein expression normalized to β-actin in normal (n = 4) and ACL rupture chondrocytes (n = 6). (Error bars = standard errors, * p < 0.05). d Quantitative MMP-13 mRNA expression in chondrocytes from patients with more than 18 months ACL injury compared to those that underwent surgery within the first 18 months after injury and normal chondrocytes (Error bars = standard errors, * p < 0.05). e and f Representative western blot of MMP-13 expression in chondrocytes from patients with more than 18 months ACL injury compared to patients with ACL-injury up to 18 months and normal chondrocytes. A bar graph showing relative MMP-13 protein expression normalized to β-actin in normal (n = 3), ACL-injury up to 18 months (n = 3) and ACL rupture more than 18 months chondrocytes (n = 3). (Error bars = standard errors, * p < 0.05)