Abstract
Stress and glucocorticoid stress hormones inhibit neurogenesis, whereas antidepressants increase neurogenesis and block stress-induced decrease in neurogenesis. Our previous studies have shown that leptin, an adipocyte-derived hormone with antidepressant-like properties, promotes baseline neurogenesis in the adult hippocampus. This study aimed to determine whether leptin is able to restore suppression of neurogenesis in a rat chronic unpredictable stress (CUS) model of depression. Chronic treatment with leptin reversed the CUS-induced reduction of hippocampal neurogenesis and depression-like behaviors. Leptin treatment elicited a delayed long-lasting antidepressant-like effect in the forced swim behavioral despair test, and this effect was blocked by ablation of neurogenesis with X-irradiation. The functional isoform of the leptin receptor, LepRb, and the glucocorticoid receptor (GR) were colocalized in hippocampal neural stem/progenitor cells in vivo and in vitro. Leptin treatment reversed the GR agonist dexamethasone (DEX)-induced reduction of proliferation of cultured neural stem/progenitor cells from adult hippocampus. Further mechanistic analysis revealed that leptin and DEX converged on glycogen synthase kinase-3Β (GSK-3Β) and Β-catenin. While DEX decreased Ser9 phosphorylation and increased Tyr216 phosphorylation of GSK-3Β, leptin increased Ser9 phosphorylation and attenuated the effects of DEX at both Ser9 and Tyr216 phosphorylation sites of GSK-3Β. Moreover, leptin increased total level and nuclear translocation of Β-catenin, a primary substrate of GSK-3Β and a key regulator in controlling hippocampal neural progenitor cell proliferation, and reversed the inhibitory effects of DEX on Β-catenin. Taken together, our results suggest that adult neurogenesis is involved in the delayed long-lasting antidepressant-like behavioral effects of leptin, and leptin treatment counteracts chronic stress and glucocorticoid- induced suppression of hippocampal neurogenesis via activating the GSK-3Β/Β-catenin signaling pathway.
Original language | English (US) |
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Pages (from-to) | 790-808 |
Number of pages | 19 |
Journal | Molecular Psychiatry |
Volume | 17 |
Issue number | 8 |
DOIs | |
State | Published - Aug 2012 |
Externally published | Yes |
Keywords
- chronic unpredictable stress
- glucocorticoids
- glycogen synthase kinase-3β
- leptin
- neurogenesis
- β-catenin
ASJC Scopus subject areas
- Psychiatry and Mental health
- Cellular and Molecular Neuroscience
- Molecular Biology