Osteoarthritic synovial tissue inhibition of proteoglycan production in XXXX osteoarthritic knee cartilage: establishment and characterization of a long-term cartilage-synovium coculture.

@entity1 @entity880 @entity571 @entity2713
OBJECTIVE: Although both cartilage and synovium are affected in @entity571 ( @entity571 ), no in vitro coculture models of @entity1 @entity571 tissue have been described. The aim of this study was to develop an in vitro model that includes both the synovium and cartilage of @entity1 with knee @entity571 . METHODS: Explants of @entity1 @entity571 cartilage and synovium were cultured alone or in coculture for 21 days. Histologic evaluation and analyses of @entity880 dehydrogenase release, matrix metalloproteinase (MMP) activity, content, release, and synthesis of glycosaminoglycan (GAG), and cytokine production were used to evaluate synovial tissue functionality and its effect on cartilage metabolism. To assess the possibility of intervention in the model system, the effect of @entity2713 was studied. RESULTS: Throughout the entire culture period, @entity571 synovial tissue remained viable and produced cytokines. Monocultures of synovial and cartilage explants produced different cytokine subsets, with the subsets found in coculture being most similar to those previously described in @entity571 synovial fluid. MMP activity was detectable only in the synovial explant monoculture and in coculture. Cocultures showed a reduction in final GAG content (P < 0.02), attributable to an inhibition of GAG production (P < 0.001) rather than an increase in GAG release. Addition of @entity2713 inhibited cytokine production and MMP activity in coculture and synovial tissue monoculture and counteracted the inhibition of GAG production induced by coculture. In cartilage monoculture, however, @entity2713 reduced GAG production. CONCLUSION: @entity571 synovium affects cartilage metabolism by reducting GAG production. @entity2713 can relieve this effect of synovial tissue, while being inhibitory when added to cartilage monoculture. These results clearly indicate the importance of tissue coculture as a promising tool for studying @entity571 pathophysiology and for development of possible interventions.
