FIG. 1.

Oxidative stress promotes delayed nuclear translocation of Foxo3a independent of Akt in C2C12 cells. (a) C2C12 cells were transiently transfected with a peceFoxo3a-WT plasmid expressing the human HA-tagged form of Foxo3a (hFoxo3a-HA). The subcellular localization of hFoxo3a-HA was monitored by immunofluorescence microscopy using an anti-HA antibody. Nuclei were stained with Hoechst stain (upper panel). Forty-eight hours after transfection, an H₂O₂ (250 μM) time course experiment was performed and localization of hFoxo3a was determined for each time point. On the graph (lower panel), the percentage of cells corresponds to the number of cells distributed among the three types of hFoxo3a-HA cellular localization (150 to 500 counted cells). (b) Akt (Ser473), Foxo3a (Thr32), JNK (Thr183-Tyr185), and p38 phosphorylations in response to H₂O₂ (250 μM) were assessed by Western blotting using 20 μg of protein loaded on an SDS-PAGE gel. For all panels, results shown are representative of 3 independent experiments.