IMMUNOLOGICAL DETECTION OF TYPE-II COLLAGEN DEGRADATION - USE IN THE EVALUATION OF ANTIARTHRITIC THERAPIES

Propagated Swarm rat chondrosarcoma cells, rabbit chrondrocytes (from articular cartilage of knee, shoulder and hip joints), and bovine nasa l cartilage explant cultures were studied. Type II collagen (CII) and its peptide fragments were quantitated in cell medium and cell layer s eparately, using two previously developed assays; one assay employed a monoclonal antibody, C4F6, that reacts specifically with triple helic al CII, and the other assay used an antibody, E1E5, that reacts specif ically with a peptide of CII. A time-dependent increase in the content of CII and CII-derived peptides was observed in both rat and rabbit c ultures. In both culture systems the majority of the native type II co llagen is found associated with the cell layer (97% in rat cultures an d 73% in rabbit cultures), while the major part of the CII peptides is found in the media (73% in rat cultures, 88% in the rabbit cultures). The concentration of peptides in the media reaches approximately 2 mu g mL(-1) in both chondrocyte monolayer cultures after 4 days. The CII peptide assay employing E1E5 was well suited to quantitate articular cartilage collagen degradation in explant culture. Thus it can be used to evaluate potential therapeutic agents that can modify or inhibit c artilage degradation. The assay has the added potential that it could be used in-vivo to evaluate the effectiveness of potential metalloprot einase inhibitors in animal models of osteoarthritis or in clinical tr ials.