Salmaso N, Stevens HE, McNeill J, ElSayed M, Ren Q, Maragnoli ME, Schwartz ML, Tomasi S, Sapolsky RM, Duman R, Vaccarino FM. Fibroblast Growth Factor 2 Modulates Hypothalamic Pituitary Axis Activity and Anxiety Behavior Through Glucocorticoid Receptors.
Biol Psychiatry 2016;
80:479-489. [PMID:
27133954 PMCID:
PMC8009045 DOI:
10.1016/j.biopsych.2016.02.026]
[Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Revised: 02/15/2016] [Accepted: 02/16/2016] [Indexed: 01/07/2023]
Abstract
BACKGROUND
Despite strong evidence linking fibroblast growth factor 2 (FGF2) with anxiety and depression in both rodents and humans, the molecular mechanisms linking FGF2 with anxiety are not understood.
METHODS
We compare 1) mice that lack a functional Fgf2 gene (Fgf2 knockout [KO]), 2) wild-type mice, and 3) Fgf2 KO with adult rescue by FGF2 administration on measures of anxiety, depression, and motor behavior, and further investigate the mechanisms of this behavior by cellular, molecular, and neuroendocrine studies.
RESULTS
We demonstrate that Fgf2 KO mice have increased anxiety, decreased hippocampal glucocorticoid receptor (GR) expression, and increased hypothalamic-pituitary-adrenal axis activity. FGF2 administration in adulthood was sufficient to rescue the entire phenotype. Blockade of GR in adult mice treated with FGF2 precluded the therapeutic effects of FGF2 on anxiety behavior, suggesting that GR is necessary for FGF2 to regulate anxiety behavior. The level of Egr-1/NGFI-A was decreased in Fgf2 KO mice and was reestablished with FGF2 treatment. By chromatin immunoprecipitation studies, we found decreased binding of EGR-1 to the GR promoter region in Fgf2 KO mice. Finally, we examined anxiety behavior in FGF receptor (FGFR) KO mice; however, FGFR1, FGFR2, and FGFR3 KO mice did not mimic the phenotype of Fgf2 KO mice, suggesting a role for other receptor subtypes (i.e., FGFR5).
CONCLUSIONS
These data suggest that FGF2 levels are critically related to anxiety behavior and hypothalamic-pituitary-adrenal axis activity, likely through modulation of hippocampal glucocorticoid receptor expression, an effect that is likely receptor mediated, albeit not by FGFR1, FGFR2, and FGFR3.
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