Figure 5

Effect of HMGB1 and IL-1β on the levels of MMP released into the medium by osteoarthritic synoviocytes. (a) Matrix metalloproteinase (MMP)-1, (b) MMP-3 and (c) MMP-13 protein levels in the medium. Cells were stimulated with IL-1b (10 ng/ml) for 24 hours in the presence or absence of high mobility group box 1 (HMGB1) at 15 and 25 ng/ml. MMP protein was measured by ELISA in supernatants. Data are expressed as mean ± standard error of the mean. Duplicate samples from six to eight patients were used. ++P < 0.01 with respect to nonstimulated cells. *P < 0.05, **P < 0.01 with respect to IL-1β.