Immunohistochemical Expression And Significance Of MMP-7, MMP-9, MMP-13 And TIMP-1 In Osteoarthritis

Objective: To investigate the relationship between degeneration of cartilage and the expressions of Matrix Metalloproteinase 7 (MMP-7), Matrix Metalloproteinase 9 (MMP-9), Matrix Metalloproteinase 13 (MMP-13) and Tissue Inhibitor of Matrix Metalloproteinase 1 (TIMP-1) in osteoarthritis.Methods: The histological changes of cartilages by hematoxyllin-eosin staining and immunohistochemical expression of MMP-7, MMP-9, MMP-13 and TIMP-1 were studied in 20 osteoarthritis cases and 5 normal controls. All data were statistically analyzed by Mann-Whitney U test and correlation analysis.Results: The osteoarthritis cartilage underwent fibroplasias and tearing. The quantity of chondrocyte increased and the clustered and hypertrophic cells came into being. Little immunostaining of MMP-7 and MMP-13 was observed in normal cartilage, while their expressions increased in degenerated cartilage (P＜0. 01). Expression of MMP-gand TIMP-1 was the same in normal cartilage(P＞0. 05), superficial layer of the moderate and end-stage osteoarthritis. However, it significantly increased in deep layer (P＜0. 01).Conclusions: The abnormal expression of MMP-7, MMP-9, MMP-13 and TIMP-1 was likely to be the pathogenesis of cartilage degeneration.