Abstract
Glucocorticoids (GCs) are frequently used for the treatment of osteoarthritis (OA) with remarkable success. However, the precise therapeutic mechanisms of the agents are not well understood. The present study was, therefore, designed to explore the mechanisms by which GCs could favorably modify the clinical conditions of OA by using synovial fibroblasts (SF) and dexamethasone (DEX) in vitro. SF was induced from synovial tissues obtained from five patients with osteoarthritis. Cells (1.0×105cells / mL) were stimulated with either 0.5μg / mL lipopolysaccharide (LPS) or 1.0μg / mL transforming growth factor β (TGF-β) in the presence of various concentrations of DEX. After 24h, culture supernatants were collected and MMPs levels were examined by ELISA. Addition of DEX at more than 50M into cell cultures could suppress MMP-1, MMP-2, and MMP-3 production from SF induced by LPS, but not TGF-β stimulation. DEX could not suppress the production of TIMPs from SF in response to LPS and TGF-β stimulation, even when DEX at more than 50M were added to cell cultures.These results suggests that DEX could suppress joint tissue remodeling through inhibition of MMP production and favorable modification of clinical condition of OA . [J Physiol Sci. 2006;56 Suppl:S239]
