Trophic effects of adipose-tissue-derived and bone-marrow-derived mesenchymal stem cells enhance cartilage generation by chondrocytes in co-culture.

Aims: Combining mesenchymal stem cells (MSCs) and chondrocytes has great potential for cell-based cartilage repair. However, there is much debate regarding the mechanisms behind this concept. We aimed to clarify the mechanisms that lead to chondrogenesis (chondrocyte driven MSC-differentiation versus MSC driven chondroinduction) and whether their effect was dependent on MSC-origin.

Glucosamine increases hyaluronic acid production in human osteoarthritic synovium explants.

Background: Glucosamine (GlcN) used by patients with osteoarthritis was demonstrated to reduce pain, but the working mechanism is still not clear. Viscosupplementation with hyaluronic acid (HA) is also described to reduce pain in osteoarthritis. The synthesis of HA requires GlcN as one of its main building blocks.

Glucosamine reduces anabolic as well as catabolic processes in bovine chondrocytes cultured in alginate.

Objective: To investigate the working mechanism of glucosamine (GlcN) by studying the effect of different GlcN derivatives on bovine chondrocytes in alginate beads under anabolic and catabolic culture conditions.

Methods: Bovine chondrocytes seeded in alginate beads were treated with different concentrations of glucosamine-sulfate (GlcN-S), glucosamine-hydrochloride (GlcN-HCl) or N-acetyl-glucosamine (GlcN-Ac). Culture conditions were anabolic, 3 day pre-culture followed by 14 days' treatment; catabolic, extracellular matrix (ECM) breakdown induced by 10ng/ml interleukin-1beta (IL-1beta); or a situation with balance between ECM breakdown and synthesis, 24 days' pre-culture followed by 14 days' treatment.

Glucosamine decreases expression of anabolic and catabolic genes in human osteoarthritic cartilage explants.

Objective: To investigate the effect of glucosamine (GlcN) in a human osteoarthritic explant model on expression of genes involved in anabolic and catabolic activities of chondrocytes.

Methods: Human osteoarthritic explants, obtained during knee arthroplasty surgery, were pre-cultured (3 days) and treated with glucosamine-hydrochloride (GlcN-HCl) or glucosamine-3-sulphate (GlcN-S) at 0.5mM and 5mM (4 days).