Establishment of rabbit osteoarthritis model and expression of MMP-1 MMP-13 in joint cartilage induced by anterior cruciate ligament transection and excision of partial medial meniscus

Purpose To evaluate the feasibility of animal model of osteoarthritis(OA) by anterior cruciate ligament transaction(ACLT) and excision of partial medial meniscus,and to explore the mRNA and protein expression of matrix metalloproteinase(MMP)-1 and MMP-13 in joint cartilage of rabbit knee at different time after ACLT and partial excision of medial meniscus. Methods Thirty rabbits in experimental group received unilateral ACLT and partial excision of medial meniscus,another 10 rabbits received unilateral arthrotomy as pseudo-operation control.Ten experimental rabbits were sacrificed at 4,8 and 12 weeks after surgery respectively,and 10 pseudo-operation rabbits were sacrificed at 12 weeks after surgery.Knees were harvested to observe the macropathologic changes of joint cartilage.Cartilage near the lesion were obtained,and mRNA and protein of MMP-1 and MMP-13 were detected by real-time PCR and western blot respectively. Results Cartilage degeneration was obvious at 4 weeks and became more severe at 8 and 12 weeks after operation,while cartilage still remained normal at 12weeks after pseudo-operation.The mRNA and protein expression of MMP-1 and MMP-13 were all lower in normal cartilage,while the mRNA and protein expression of those two proteins increased in 4 and 8 weeks after operation.At 12 weeks after operation,mRNA and protein expression of MMP-1 still remained high,while mRNA and protein expression of MMP-13 decreased respectively. Conclusions Anterior cruciate ligament transaction(ACLT) with partial excision of medial meniscus is a good method to make osteoarthritis model.MMP-1 and MMP-13,especially MMP-1,are good markers in osteoarthritis study.MMP-13 expression was very different from that of MMP-1 at 12 weeks after operation,which suggest that their upstream signaling pathways are different,and the signaling pathway difference may be before translation because the mRNA and protein expression change of MMP-13 are in parallel.