Figure 4

Urokinase-type plasminogen activator (u-PA) activity in healthy (H) and rheumatoid arthritis (RA) synoviocytes treated with Raloxifene (RAL). Samples were analyzed both in basal conditions and after treatment with 0.5 and 1 μM RAL (48 h). (a) Zymographic assay of aliquots of the culture medium. u-PA digestion of plasminogen shows clear bands of lysis in the cloudy casein background of the indicating layer. Shown here are the effects on one H and one RA line; the other lines furnished similar results. (b) Direct fibrinolytic assay of cell membrane-associated plasminogen activators. Left side: lysis areas of culture medium under the indicated experimental conditions. Right side: lysis areas of aliquots of the acidic wash (Ac), indicating the activity eluted from the cell surface. The diameter (mm) of the lysis areas were measured as an index of fibrin digestion. H refers to four different synovial cell cultures from healthy individuals; RA refers to synovial cell cultures from four different RA patients Each point represents the mean ± standard deviation of three experiments performed in triplicate on each synovial cell line. § = p < 0.01 versus control (C).