Influence of Periostin on Synoviocytes in Knee Osteoarthritis

BACKGROUND: Periostin (POSTN) is a protein that binds to integrins to support adhesion and migration of epithelial cells. Mice lacking this gene exhibit cardiac valve disease as well as skeletal and dental defects. Recent studies indicated that periostin is involved in the pathogenesis and progression of knee osteoarthritis (OA). We investigated the influence of periostin and matrix metalloproteinases (MMPs) on OA synoviocytes. MATERIALS AND METHODS: OA patients were classified according to the Kellgren-Lawrence system and the levels of periostin, interleukin (IL)-4, IL-13 and transforming growth factor-β (TGFβ) in the synovial fluid were measured. MMPs or tissue inhibitor of MMPs (TIMPs) with periostin in cultured cells were measured when periostin was added to OA-associated synovial cells. Dexamethasone, a steroid medication which shows immunosuppressive effects, was used to investigate the influence of the downstream cascade. RESULTS: Periostin and IL-13 levels were up-regulated during the progression of OA. MMP-2 and MMP-3 levels increased in a periostin concentration-dependent manner. Increase in MMP-2 and MMP-3 levels was inhibited by dexamethasone treatment. CONCLUSION: In vivo results herein indicate that IL-13 may induce periostin production in OA. Furthermore, periostin may facilitate MMP production in OA-associated synovial cells.