Figure 4.

Effects of compound 1 on RA-FLS apoptosis. (A) After treatment with compound 1 (0.1 or 1 μM) or dimethyl sulphoxide (DMSO) vehicle for 48 h, apoptotic cell death measured by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) assay (×100). Bright spots in the lower panels are TUNEL-positive apoptotic cells. Corresponding phase contrast microscopy images are shown in the upper panels; (B) The apoptosis index of RA-FLS treated with 0.1 or 1 μM of compound 1 or DMSO vehicle. Data were shown as means ± S.E.M. of three independent experiments (* p < 0.05); (C) Effects of compound 1 on the levels of active caspase-3/7. RA-FLS cells were treated with 0.1 or 1 μM of compound 1 for 48 h and then processed to measure using the Caspase-Glo kit. Data were shown as means ± S.E.M. of three independent experiments (* p < 0.05); (D) Effects of compound 1 on sub-G₁ fractions of RA-FLS. After treatment with compound 1 for 48 h at the concentration of 0.1 or 1 μM, cells were harvested by trypsinization, and analyzed using flow cytometry.