Bcl-2 and Bax expression in synoviocytes in rheumatoid arthritis (RA). (A) Fibroblast-like synoviocytes (FLSs) from RA patients (n = 3) and osteoarthritis (OA) patients (n = 3) were cultured. The expression of Bcl-2 and Bax mRNA in synoviocytes was evaluated by real-time PCR. *P < 0.05, **P < 0.01 compared with OA. (B) Expression of Bcl-2 and Bax in synoviocytes was evaluated by western blot. The representative figure is shown in the left panel. The optical density (OD) ratio of Bcl-2 and Bax between FLSs in RA and OA is shown in the right panel. *P < 0.05 compared with OA. (C) Expression of Bcl-2 in FLSs in RA and OA was evaluated by confocal microscopy. Bcl-2 expressing FLSs are shown as green. Staining for nuclei by 4',6-diamidino-2-phenylindole (DAPI) is shown as blue. The representative figure is shown. (D) Apoptosis was induced by treating the cells with 1 mM sodium nitroprusside (SNP). The degree of apoptosis was assessed by flow cytometry using propidium iodide (PI) and Annexin V. A (apoptotic cells) were defined as PI-Annexin V+ cells. **P < 0.01 compared with OA.
Lee et al. Arthritis Research & Therapy 2013 15:R31 doi:10.1186/ar4179