Type ii collagen degradation in spontaneous osteoarthritis in C57B1/6 and BALB/c mice

Objective. Degradation of type II collagen during osteoarthritis (OA) is th ought to be the key process leading to cartilage destruction. In this study , we investigated whether OA is characterized by either a generalized break down of the collagenous network or a localized process. Furthermore, we det ermined if collagen degradation was linked to cell death. Methods, Two mouse strains that develop spontaneous OA, C57B1/6 and BALB/c mice, were examined. Type II collagen degradation in type II collagen-induc ed arthritis was also examined for comparison. Immunolocalization with the COL2-3/4m and COL2-3/4C antibodies was used to demonstrate denatured type I I collagen and the collagenase cleavage site in type II collagen, respectiv ely. Results. Both the C57B1/6 and the BALB/c mice developed OA changes, althoug h clear compartmental differences existed between the two strains, In both strains, type II collagen degradation was clearly present at sites of degen eration, but was absent from intact articular cartilage. Collagen degradati on was absent from areas with cell death. Conclusion. These results indicate that type II collagen degradation in spo ntaneous murine OA is associated with degeneration and is a localized, inst ead of a generalized, process.