Abstract

Background: Knee osteoarthritis (OA) is well known to be one of the most common joint disease in elderly people and characterized by pain, stiffness and loss of function in articulating joints, which develop slowly and worsen over time. Chondroitin sulfate (CS) and glucosamine hydrochloride are used for the treatment of OA and reported that these substances are favorably modify the clinical symptoms, especially pain, however, the therapeutic mechanisms of these substances are not fully understood. The present study was undertaken to examine the influence of CS on the production of periostin, which is one of the important molecules associated with OA development, by synoviocytes from an OA patient by an in vitro cell culture technique.
Methods: Synoviocytes (1 x 10⁵ cell/ml) were stimulated with 10.0 ng/ml IL-13 in the presence of various concentrations of CS. After 48 h, periostin content in culture supernatants was examined by ELISA. We also examined the influence of CS on transcription factor, STAT6, activation and periostin mRNA expression in synoviocytes 12 and 24 h after IL-13 stimulation, respectively.
Results: Addition of CS into cell cultures caused the suppression of periostin production from synoviocytes induced by IL-13 stimulation through the inhibition of STAT6 activation and periostin mRNA expression. The minimum concentration of CS that caused significant suppression of periostin production, STAT6 activation and mRNA expression was 10.0 μg/ml.
Conclusion: These results strongly suggest that the ability of CS to suppress periostin production from synoviocytes may account, at least in part, for the clinical efficacy of CS on OA.