SIRT1 overexpression inhibited proliferation and induces apoptosis in RA-FLS
RA-FLS was transfected with pCDNA3.1 or pCDNA3.1-SIRT1 and SIRT1 mRNA (A), and protein expression (B) relative to GAPDH was measured. (C) RA-FLS proliferation was measured by a CCK-8 assay at 24, 48, and 72 h post-transfection. (D) Cell cycle analysis of transfected RA-FLS was performed by flow cytometry after DNA staining with propidium iodide and categorized into G0/G1, S, and G2/M phases. (E) Apoptosis in transfected RA-FLS was measured by flow cytometry and quantified as combined percentage of FITC+/PI- (Q4) and FITC+/PI+ (Q2) cells. (F and G) Relative activity of caspase-3 and caspase-8 was determined by colorimetric protease assays in transfected RA-FLS; N = 6, mean ± SD, *P<0.05, **P<0.01.