Fig. 1
Effect of SOD2 knockdown on cellular O2.− level and ferroptosis markers in 5-8F and CNE 2 nasopharyngeal carcinoma cells. A Western blot and bar plot showing MnSOD expression in control and SOD2 knockdown cells. The blots are from different parts of the same gel. B Fluorescence microscopy images and bar plot showing the upregulation of O2..− fluorescence intensity in SOD2 knockdown 5-8F cells. Cells were treated with fluorescent probes, DCFD and DHE. C Confocal microscopy images and bar plots showing the effect of SOD2 knockdown on oxidized C11 BODIPY 581/591 fluorescence intensity (green color). SOD2 knockdown cells were treated with 5 µM deferoxamine (DFO), an iron chelator widely used as a ferroptosis inhibitor. D The concentration of the lipid peroxidation marker, MDA (nmol/mg total protein). E Cell viability in control, SOD2 knockdown, and DFO (5 µM)-treated cells. F Electron micrographs showing mitochondrial damage (red arrows) in SOD2 knockdown cells which were rescued by 5 µM DFO. Mitochondrial damage is revealed by alterations in membrane structure. Data are presented as mean ± s.d. n ≥ 3 independent repeats. **P < 0.01, ***P < 0.001, ****P < 0.0001