Figure 1: FOXO response to oxidative stress a) under
normal conditions, wingless proteins (Wnt) inactivate GSK-3 through
disheveled (dvl) and promote β-catenin accumulation in the nucleus, thus
activating transcription factors of the T-cell factor family (TCF). (b)
in the status of oxidative stress, Wnt is inhibited leading to the
disinhibition of GSK-3, which in turn, promotes τ protein
phosphorylation. The available β catenin now preferably binds to FOXO
proteins, thus upregulating the transcription of genes. In the case of
prolonged FOXO activity, apoptosis is initiated and leads to neuronal
degeneration.