Gene deficiency and pharmacological inhibition of caspase-1 confers resilience to chronic social defeat stress via regulating the stability of surface AMPARs

Mol Psychiatry. 2018 Mar;23(3):556-568. doi: 10.1038/mp.2017.76. Epub 2017 Apr 18.

Abstract

Both inflammatory processes and glutamatergic systems have been implicated in the pathophysiology of mood-related disorders. However, the role of caspase-1, a classic inflammatory caspase, in behavioral responses to chronic stress remains largely unknown. To address this issue, we examined the effects and underlying mechanisms of caspase-1 on preclinical murine models of depression. We found that loss of caspase-1 expression in Caspase-1-/- knockout mice alleviated chronic stress-induced depression-like behaviors, whereas overexpression of caspase-1 in the hippocampus of wild-type (WT) mice was sufficient to induce depression- and anxiety-like behaviors. Furthermore, chronic stress reduced glutamatergic neurotransmission and decreased surface expression of glutamate receptors in hippocampal pyramidal neurons of WT mice, but not Caspase-1-/- mice. Importantly, pharmacological inhibition of caspase-1-interleukin-1β (IL-1β) signaling pathway prevented the depression-like behaviors and the decrease in surface expression of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (AMPARs) in stressed WT mice. Finally, the effects of chronic stress on both depression- and anxiety-like behaviors can be mimicked by exogenous intracerebroventricular (i.c.v.) administration of IL-1β in both WT and Caspase-1-/- mice. Taken together, our findings demonstrate that an increase in the caspase-1/IL-1β axis facilitates AMPAR internalization in the hippocampus, which dysregulates glutamatergic synaptic transmission, eventually resulting in depression-like behaviors. These results may represent an endophenotype for chronic stress-induced depression.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Anxiety / metabolism
  • Behavior, Animal / drug effects
  • Caspase 1 / genetics*
  • Caspase 1 / metabolism*
  • Depression / genetics
  • Depression / metabolism
  • Disease Models, Animal
  • Hippocampus / metabolism
  • Interleukin-1beta / metabolism
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Mood Disorders / metabolism
  • Receptors, Glutamate / metabolism
  • Resilience, Psychological
  • Stress, Psychological / genetics
  • Synaptic Transmission
  • alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid / metabolism*

Substances

  • Interleukin-1beta
  • Receptors, Glutamate
  • alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid
  • Casp1 protein, mouse
  • Caspase 1