Figure 2

Effect of eotaxin-1 on the MMP-3 protein secretion in human chondrocytes. Human SW1353 chondrosarcoma cells and primary chondrocytes were cultured and treated in different conditions. MMP-3 protein levels were analyzed by Western blotting, and quantified. All values were normalized to the one without eotaxin-1. (A) SW1353 cells were incubated with 1 ng/ml IL-1β and 100 ng/ml eotaxin-1 for various time periods or only IL-1β for 24 h, and MMP-3 protein expressed in cells (c.MMP-3) and culture media (m.MMP-3) were analyzed and quantified. (B) SW1353 or primary cells were incubated with IL-1β (1 ng/ml) for 4 h followed by actinomycin D (5 μg/ml) for 1 h. The medium was then refreshed, and the cells were treated with various concentrations of eotaxin-1 for 2 h. MMP-3 protein in culture medium was determined. The values are the mean of at least three assays. * p < 0.05.