Stimulation of proteoglycan production by glucosamine sulfate in chondrocytes isolated from human osteoarthritic articular cartilage in vitro

Objective: This study investigated the in-vitro effects of a crystalline glucosamine sulfate (GS) preparation on DNA synthesis and on proteoglycan (PG) and type II collagen (coll II) production by human articular chondrocytes isolated from human osteoarthritic articular cartilage in a 3-dimensional culture system for 4, 8, and 12 days. Materials and Methods: Human articular chondrocytes from osteoarthritic femoral heads were isolated from their matrix by collagenase digestion and then cultured in suspension. Under constant agitation, cells aggregated and formed a cluster within a few days. The effects of GS (1-100 mu g/ml) on chondrocytes were determined by quantifying DNA synthesis (by measurement of [H-3]-thymidine uptake) as well as PG and coil II production using radioimmunoassays (RIAs) specific for coil II and to human human cartilage PG. Cross-reaction with GS in the RIAs was not detected. Moreover, PG size distribution was determined by exclusion chromatography under associative conditions to determine the association of PG monomers with hyaluronic acid (HA) to form large molecular weight PG aggregates. Results: Under the above conditions, PCT production in culture media and chondrocyte clusters was increased by GS (10 100 mu g/ml). DNA synthesis and coil II production were not modified by GS. In addition, CTS did not modify the physico-chemical form of PG produced by cells during culture. Conclusions: Glucosamine sulfate did not affect DNA synthesis nor coil II production but caused a statistically significant stimulation of PG production by chondrocytes from human osteoarthritic cartilage cultured for up to 12 days in 3-dimensional cultures.