|Effect of adiponectin on the production of vascular endothelial growth factor and matrix metalloproteinases in rheumatoid arthritis fibroblast-like synoviocytes|
Next, to evaluate whether adiponectin stimulates the production of VEGF and MMPs for angiogenesis of pannus and joint destruction in RA FLSs, VEGF and MMP production was evaluated in the supernatants of cell cultures treated with adiponectin or IL-1β (Figure 2). Both adiponectin and IL-1β strongly stimulated the production of VEGF, MMP-1, and MMP-13 in RA FLSs. However, the expressions of MMP-2 and MMP-9 were not increased by either adiponectin or IL-1β at the mRNA or protein level. Consistent with the mRNA levels (data not shown), the protein levels of VEGF, MMP-1, and MMP-13 elevated by treatment with 10 μg/mL adiponectin were similar to those after treatment with 1 ng/mL IL-1β. The difference between adiponectin and IL-1β was not statistically significant, suggesting that adiponetin may have a role in the production of VEGF and MMPs like IL-1β does.