Synovial fluid enhances proliferation and migration in canine keratocytes

Synovial fluid (SF) contains various factors which may be helpful for corneal stromal healing, such as cytokines, growth factors, hyaluronic acid, and proteins. Therefore, the purpose of this study was to determine the effect of SF on proliferation and migration in canine keratocytes. In order to evaluate the degree of proliferation and migration, canine keratocytes were cultured in DMEM containing 1%, 3%, 5%, or 10% SF. Real-time PCR was performed in a control group and the group treated with 5% SF, in order to measure the expression levels of factors associated with corneal wound healing. These factors included interleukin-1α (IL-1α), hepatocyte growth factor (HGF), transforming growth factor-β (TGF-β), and α-smooth muscle actin (SMA-α). Proliferation assays demonstrated that proliferation was significantly enhanced in groups treated with greater than 3% SF, as compared with that of the control group. In addition, migration in all SF-treated groups was significantly increased as compared with migration in the control group, as measured by migration assays. mRNA expression of IL-1α and HGF was significantly increased and mRNA expression of TGF-β and SMA-α was significantly decreased in the cells treated with 5% SF. These findings suggest that SF may promote corneal wound healing.