Figure 1.

H₂O₂ promotes SOD1 nuclear translocation. Immunofluorescence using the antibody against SOD1 (green) and DAPI (blue, a nucleus-staining dye) indicated a redox-dependent distribution within HeLa cells. After HeLa cells were treated respectively with or without 0.4 mM H₂O₂, 2 mM GSH and 50 μM LD100 for 4 h, immunofluorescence staining was performed. Scale bars, 25 μm. Finally, we quantified the fluorescence intensity of SOD1 in the nucleus and cytoplasm using ImageJ, and then obtained the percentage of SOD1 in the nucleus (n > 20). Data are mean ± SD.