Effects of chondroitin sulfate and interleukin-1β on human articular chondrocytes cultivated in clusters

Abstract

Objective: To test the effects of chondroitin sulfate (ACS, a glycosaminoglycan of cartilage) with an without interleukin-1β (IL-1β) on human articular chondrocytes cultivated in clusters and in long-term (0-16 days or 16-32 days). Design: Chondrocyte productions of proteoglycans (PGs), type II collagen (coll-II) and prostaglandin E2 (PGE2) were assayed by specific radioimmunoassays applied to conditioned culture media and to clusters. Results: During the two culture periods (0-16 days or 16-32 days), ACS (100-1000 μg/ml) increased total PG production and had no effect on the production of coll-II by chondrocytes. During the first 16 days, ACS (500- 1000 μg/ml) decreased total PGE2 synthesis. IL-1β decreased PG and coll- II productions and increased PGE2 synthesis. During the first period (0-16 days), while the cluster is forming, ACS counteracted the IL-1β-induced effects on PG (500-1000 μg ACS/ml), coll-II (100-1000 μg ACS/ml) and PGE2 (500-1000 μg ACS/ml) productions. During the second period (16-32 days), when the cluster is already formed, ACS counteracted the IL-1β-induced effects on total PG (100-1000 μg ACS/ml), coll-II (1000 μg ACS/ml) and PGE2 (1000 μg ACS/ml) productions. Conclusions: These in vitro studies suggest that ACS is able to increase matrix component production by human chondrocytes and to inhibit the negative effects of IL-1β.