Vascular endothelial growth factor-dependent spinogenesis underlies antidepressant-like effects of enriched environment

J Biol Chem. 2012 Nov 30;287(49):40938-55. doi: 10.1074/jbc.M112.392076. Epub 2012 Oct 16.

Abstract

Current antidepressant treatments remain limited by poor efficacy and a slow onset of action. Increasing evidence demonstrates that enriched environment (EE) treatment can promote structural and behavioral plasticity in the brain and dampen stress-induced alterations of neuroplasticity. Here, we have examined whether short term exposure to EE is able to produce antidepressant-like effects. Our results show that housing adult mice in an EE cage for 7 days led to antidepressant-like behavioral profiles and a significant increase in the number of dendritic spines in hippocampal CA1 pyramidal neurons. These EE-induced antidepressant-like effects are primarily attributed to increased vascular endothelial growth factor (VEGF) expression through a hypoxia-inducible factor-1α (HIF-1α)-mediated transcriptional mechanism. Blockade of HIF-1α synthesis by lentiviral infection with HIF-1α small hairpin RNAs completely blocked the increase in expression of VEGF and the antidepressant-like effects induced by EE. Moreover, no significant antidepressant-like effects were observed with EE treatment in VEGF receptor 2 (Flk-1) knock-out mice. The increase in HIF-1α expression in the hippocampus induced by EE was associated with a decrease in endogenous levels of microRNA-107 (miR-107). Overexpression of miR-107 in the hippocampus completely blocked EE-induced HIF-1α expression and the antidepressant-like effects. These results support a model in which the down-regulation of miR-107, acting through HIF-1α, mediates VEGF-dependent spinogenesis to underlie the EE-induced antidepressant-like effects.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antidepressive Agents / pharmacology*
  • Brain / metabolism
  • Brain / physiology*
  • Corticosterone / metabolism
  • Environment
  • Golgi Apparatus / metabolism
  • Hippocampus / metabolism
  • Hippocampus / physiology
  • Hypoxia-Inducible Factor 1, alpha Subunit / metabolism
  • Lentivirus / genetics
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Mice, Transgenic
  • MicroRNAs / metabolism
  • Neuronal Plasticity
  • Neurons / metabolism
  • Synapses / physiology
  • Transcription, Genetic
  • Vascular Endothelial Growth Factor A / metabolism*

Substances

  • Antidepressive Agents
  • Hypoxia-Inducible Factor 1, alpha Subunit
  • MIRN107 microRNA, mouse
  • MicroRNAs
  • Vascular Endothelial Growth Factor A
  • Corticosterone