Figure 5

CP690,550 suppresses OSM-induced JAKs/STATs activation in RA-FLS; CP690,550 inhibits OSM-induced MAPKs activation RA-FLS. (a) Quiescent RA-FLS were pretreated with various concentrations of CP690,550 for 2 hours, then stimulated with OSM (20 ng/ml) for 20 minutes. Cellular lysates were subjected to Western blotting using phospho-specific antibodies against JAK1, JAK2, JAK3, STAT1, STAT3 and STAT5. Three experiments were performed using different RA-FLS and a representative result is shown. (b) Quiescent RA-FLS were pretreated with various concentrations of CP690,550 for 2 hours, then stimulated with OSM (20 ng/ml) for 20 minutes. Cellular lysates were subjected to Western blotting using phospho-specific antibodies against ERK1/2, p38 and JNK1/2. Three experiments were performed using different RA-FLS and a representative result is shown.