FoxO1, also named FKHR is a member of the FoxO subfamily, which belongs to the Fox family, a family of transcription factors containing a highly conserved, winged-helix DNA-binding domain and the forkhead motif [16, 17]. FoxO proteins can bind to the regulatory sequence of downstream target genes and play important roles in regulating the transcription of genes involved in multiple biological and pathological systems, including the central nervous system. Recent studies provide evidence for the role of FoxO proteins in the pathogenesis of depression and other psychiatric disorders [18, 19]. FoxO1 is highly expressed in brain areas related to the regulation of mood and stress [20], and FoxO1-deficient mice show a depressive-like phenotype in forced swim test (FST) and tail suspension test (TST) behaviors assessments [18], which means FoxO1 may be involved in the pathology of depression.
