Fig. 3
ROS-mediated cytosolic DNA release and cellular senescence. (a) ROS levels were measured by DCFDA staining of cells treated with H2O2 at the indicated concentrations. The fluorescence intensities of DCFDA were normalized to the control values. The asterisk indicates a significant increase in ROS levels compared with nonirradiated control cells(*p < 0.05, **p < 0.01). (b) Images of β-gal staining (green), cytosolic DNA staining (red) and nuclear staining (blue) following H2O2 treatment or 1-Gy-irradiation of TIG-3 cells. Scale bar is 50 μm. (c) Induction of cytosolic DNA release following H2O2 treatment. The asterisk indicates a significant increase in the amount of cytosolic DNA compared with nonirradiated control cells (*p < 0.05, **p < 0.01). (d) Induction of cellular senescence by H2O2 treatment and X-ray irradiation. The asterisk indicates a significant increase in the percentage of senescent cells compared with nonirradiated control cells. (e) Association between cytosolic DNA and cellular senescence. The asterisk indicates a significant increase in the number of senescent cells harboring cytosolic DNA compared with nonirradiated control cells (*p < 0.05, **p < 0.01).
