BDNF release and signaling are required for the antidepressant actions of GLYX-13

Mol Psychiatry. 2018 Oct;23(10):2007-2017. doi: 10.1038/mp.2017.220. Epub 2017 Dec 5.

Abstract

Conventional antidepressant medications, which act on monoaminergic systems, display significant limitations, including a time lag of weeks to months and low rates of therapeutic efficacy. GLYX-13 is a novel glutamatergic compound that acts as an N-methyl-D-aspartate (NMDA) modulator with glycine-like partial agonist properties; like the NMDA receptor antagonist ketamine GLYX-13 produces rapid antidepressant actions in depressed patients and in preclinical rodent models. However, the mechanisms underlying the antidepressant actions of GLYX-13 have not been characterized. Here we use a combination of neutralizing antibody (nAb), mutant mouse and pharmacological approaches to test the role of brain-derived neurotrophic factor-tropomyosin-related kinase B (BDNF-TrkB) signaling in the actions of GLYX-13. The results demonstrate that the antidepressant effects of GLYX-13 are blocked by intra-medial prefrontal cortex (intra-mPFC) infusion of an anti-BDNF nAb or in mice with a knock-in of the BDNF Val66Met allele, which blocks the processing and activity-dependent release of BDNF. We also demonstrate that pharmacological inhibitors of BDNF-TrkB signaling or of L-type voltage-dependent Ca2+ channels (VDCCs) block the antidepressant behavioral actions of GLYX-13. Finally, we examined the role of the Rho GTPase proteins by injecting a selective inhibitor into the mPFC and found that activation of Rac1 but not RhoA is involved in the antidepressant effects of GLYX-13. Together, these findings indicate that enhanced release of BDNF through exocytosis caused by activation of VDCCs and subsequent TrkB-Rac1 signaling is required for the rapid and sustained antidepressant effects of GLYX-13.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Antidepressive Agents / metabolism
  • Antidepressive Agents / pharmacology
  • Brain-Derived Neurotrophic Factor / drug effects*
  • Brain-Derived Neurotrophic Factor / metabolism
  • Brain-Derived Neurotrophic Factor / physiology
  • Depression / drug therapy
  • Ketamine / pharmacology
  • Male
  • Membrane Glycoproteins / drug effects
  • Membrane Glycoproteins / metabolism
  • Mice
  • Mice, Inbred C57BL
  • N-Methylaspartate / antagonists & inhibitors
  • Oligopeptides / metabolism*
  • Oligopeptides / pharmacology*
  • Prefrontal Cortex / metabolism
  • Rats
  • Rats, Sprague-Dawley
  • Receptor, trkB / drug effects
  • Receptors, N-Methyl-D-Aspartate / metabolism
  • Signal Transduction / drug effects

Substances

  • Antidepressive Agents
  • Brain-Derived Neurotrophic Factor
  • Membrane Glycoproteins
  • Oligopeptides
  • Receptors, N-Methyl-D-Aspartate
  • N-Methylaspartate
  • Ketamine
  • GLYX-13 peptide
  • Receptor, trkB