Figure 3

MMP-2 production is decreased in MIF -/- mice compared with WT mice. (a) Following zymosan-induced arthritis induction, MMP-2 in mouse knee homogenates was measured by ELISA and normalized to total protein. The mean concentration of MMP-2 ± standard error of the mean (SEM) is represented; *P < 0.05 (n = number of mice per group). We found that MIF -/- mice had significantly less joint MMP-2 compared with WT mice. (b) Consistent with these results, using gelatin zymography, we found enhanced MMP-2 expression (both the proform and the active form of MMP-2) in antigen-induced arthritis joint homogenates of WT compared with MIF -/- mice. Results are from one representative mouse from each group of four examined. MIF -/-, macrophage migration inhibitory factor gene-deficient; MMP, matrix metalloproteinase; WT, wild-type.