The mRNA expression of MMP-1 and MMP-9 in the cartilage of rabbits with traumatic osteoarthritis

Objective To observe the mRNA expression of matrix metalloproteinase-1,-9(MMP-1、MMP-9)in cartilage of traumatic osteoarthritis(OA)in anterior cruciate ligament transaction(ACLT)of rabbit model and to explore the effects of MMP-1 and MMP-9 in Cartilage degeneration of OA.Methods Traumatic OA was induced in 20 rabbits by ACLT of right knee and 10 rabbits killed 4 and 8 weeks respectively after the operation.Other 10 rabbits received right knee arthrotomy as pseudo operative controls and were killed 8 weeks after operation.Cartilagineus changes of the medil femoral condyles were grossly checked and OA severity observed under dissecting microscope.The mRNA expression of MMP-1 and MMP-9 in cartilage of the medil femoral condyles was assessed by Reverse Transcription-Polymerase Chain Reaction(RT-PCR).Results Cartilage degeneration in ACLT group was significantly severer than that in control group(P0.05).Cartilage degeneration in 8-week group was also severer than that in 4-week group(P0.05).The expression of MMP-1 and MMP-9 mRNA in ACLT group was significantly higher than those in control group(P0.01).The mRNA expression of MMP-1 and MMP-9 in 8-week group was also higher than those in 4-week group(P0.01).Conclusions The expression of MMP-1 and MMP-9 mRNA was up-regulation in cartilage of traumatic OA model.To some extent the mRNA expression of MMP-1 and MMP-9 can be as an evaluation index for the degree of Cartilage degeneration in traumatic OA.