Fig. 4

Fig. 4

Removing ROS by NAC down-regulates S-protein-induced senescence of ARPE-19 cells. A Flow cytometry assay measuring DCFH-DA-degenerated fluorescence level in ARPE-19 cells that were treated with S-protein for 24 h (upper panel) or transfected with plasmid p3xFlag-S (lower panel). B and C Quantitation of DCFH-DA fluorescence in A. The data represent mean ± SD (n = 3), ***p < 0.001. D SA-β-Gal stain of ARPE cells that were treated with S-protein or S-protein + NAC for 48 h. E Quantitation of the percentage of SA-β-Gal positive cells in D. The data represent mean ± SD (n = 3), ***p < 0.001. F SA-β-Gal stain of ARPE-19 cells that were transfected with p3xflag-S followed by NAC treatment for 48 h. G, Quantitation of percentage of SA-β-Gal positive cells in F. The data represent means ± SD (n = 3), ***p < 0.001. H, immunoblot the expression of P53, P21 and GAPDH in ARPE-19 cells that were treated with media containing PBS (lane 1), S-protein (lane 2) and S-protein + NAC (lane 3)