EFFECTS OF CHONDROITIN SULFATE AND INTERLEUKIN-1-BETA ON HUMAN ARTICULAR CHONDROCYTES CULTIVATED IN CLUSTERS

Objective: To test the effects of chondroitin sulfate (ACS, a glycosam inoglycan of cartilage) with and without interleukin-lp (IL-IP) on hum an articular chondrocytes cultivated in clusters and in long-term (0-1 6 days or 16-32 days). Design: Chodrocyte productions of proteoglycans (PGs), type II collagen (coll-II) and prostaglandin E-2 (PGE(2)) were assayed by specific radioimmunoassays applied to conditioned culture media and to clusters. Results: During the two culture periods (0-16 d ays or 16-32 days), ACS (100-1000 mu g/ml) increased total PG producti on and had no effect on the production of cell-II by chondrocytes. Dur ing the first 16 days, ACS (500-1000 mu g/ml) decreased total PGE(2) s ynthesis. IL-1 beta decreased PG and cell-II productions and increased PGE(2) synthesis. During the first period (0-16 days), while the clus ter is forming, ACS counteracted the IL-IP-induced effects on PG (500- 1000 mu g ACS/ml), coil-II (100-1000 tig ACS/ml) and PGE(2) (500-1000 mu g ACS/ml) productions. During the second period (16-32 days), when the cluster is already formed, ACS counteracted the IL-lp-induced effe cts on total PG (100-1000 mu g ACS/ml), cell-II (1000 mu g ACS/ml) and PGE(2) (1000 mu g ACS/ml) productions. Conclusions: These in vitro st udies suggest that ACS is able to increase matrix component production by human chondrocytes and to inhibit the negative effects of IL-1 bet a.