Expression of MMP-1, MMP-3 and iNOS in cartilage of experimental rabbit osteoarthritis induced by anterior cruciate ligament transection

Objective To observe the expression of matrix metalloproteinases(MMP)-1,MMP-3 and iNOS in cartilage of experimental rabbit osteoarthritis at different time intervals after anterior cruciate ligament transection(ACLT)operation.The aim of this study is to provide the theoritical evidence for using ACLT rabbit model in Osteoarthritis(OA)research.Methods Unilateral ACLT was performed on 27 randomly selected while rabbits and underwent unilateral arthrotomy was performed on the other 9 white rabbits as the control group.Nine randomly selected white rabbits in experimental group were killed and 3 white rabbits in the control group at 4th,8th and 12th week respectively.Cartilage degradation of femoral condyles was evaluated macr-oscopically,mRNA expression level and protein expression level of MMP-1,MMP-3 and iNOS was measured by reverse transcription-polymerase chain reaction(RT-PCR)and immunohistochemistry respectively.Results Forepart OA cartilage degradation was observed at the 4th week and became more severe at the 8th week after ACLF.Afterpart cartilage degradation was evident at the 12th week after ACLT while cartilage still remained normal in the control group,mRNA expression level and protein expression level of MMP-1.MMP-3 and iNOS were increased at the 4th week and became higher gradually at the 8th,12th week after ACLT compared with the control group.Expression distribution of MMP-1,MMP-3 and iNOS bad different patterns respectively.Conclusion It is suggested that the process of OA cartilage degradation can be simulated by ACLT model and MMP-1,MMP-3 and iNOS may be good markers in therapeutical research of OA.