To study the levels of cartilage oligomeric matrix protein (COMP) and matrix metalloproteinase-3 (MMP-3) in the serum fluid of osteoarthritic rabbit models and their relationships with the severity of pathological changes, so as to investigate their correlation with osteoarthritis (OA).
The osteoarthritic animal models were get from immobilizing the right knees of 18 rabbits in full extension using plaster cast. Knee joint pathological changes of 2, 6 weeks were examined for pathological severity of OA; ELISA sandwich method was used to measure the levels of COMP and MMP-3 in serum before and after modeling (at 2, 6 weeks respectively); X ray of model keens was also obtained in different period. Correlation analysis was performed to demonstrate the relationship between the levels of COMP, MMP-3 in the serum and the pathological severity of OA.
(1) Morphological observations:immobilizing the right knees of rabbits in full extension using plaster cast was a reliable method for osteoarthritic animal models and the typical histopathologic character was seen; the severity of osteoarthritis gradually increased with time extended. (2) The levels of COMP [(3.64 ± 0.18) µg/L], MMP-3 [(1.99 ± 0.81) µg/L] in the serum of 2 weeks osteoarthritic animal models were higher than those before immobilizing with plaster cast [COMP (3.35 ± 0.20) µg/L, MMP-3 (1.61 ± 0.71) µg/L]. The levels of COMP [(3.96 ± 0.44) µg/L], MMP-3 [(3.44 ± 0.91) µg/L] of 6 weeks were much higher, with a significant difference (P < 0.05). The levels of COMP, MMP-3 in serum had a linear correlation with the pathological severity of OA (r > 0.710, and P < 0.05).
The levels of COMP and MMP-3 in serum can help to predict and evaluate the progression of OA.