FIGURE 7.

Starvation promotes nuclear localization of endogenous FoxO1 and FoxO3 in cardiomyocytes. A–H, fed (DMEM plus glucose, no serum) and starved (DMEM alone) treated rat neonatal cardiomyocytes were immunostained with FoxO1 (green, A–D) and FoxO3 (green, E–H) antibodies. In fed cardiomyocytes FoxO1 (A) and FoxO3 (E) are localized to the cytoplasm and perinuclear region. Starvation causes predominant nuclear localization of FoxO1 (B–D) and FoxO3 (F–H) within 2 h, and nuclear localization is maintained at least for 24 h. I–K, starvation induces autophagy within 2 h, which is maintained for 24 h as measured by the increased level of LC3II and the ratio of LC3II/LC3I compared with fed cardiomyocytes. Significance (*) was determined by one-way ANOVA (p < 0.05; n = 3).