eEF2K/eEF2 Pathway Controls the Excitation/Inhibition Balance and Susceptibility to Epileptic Seizures

Cereb Cortex. 2017 Mar 1;27(3):2226-2248. doi: 10.1093/cercor/bhw075.

Abstract

Alterations in the balance of inhibitory and excitatory synaptic transmission have been implicated in the pathogenesis of neurological disorders such as epilepsy. Eukaryotic elongation factor 2 kinase (eEF2K) is a highly regulated, ubiquitous kinase involved in the control of protein translation. Here, we show that eEF2K activity negatively regulates GABAergic synaptic transmission. Indeed, loss of eEF2K increases GABAergic synaptic transmission by upregulating the presynaptic protein Synapsin 2b and α5-containing GABAA receptors and thus interferes with the excitation/inhibition balance. This cellular phenotype is accompanied by an increased resistance to epilepsy and an impairment of only a specific hippocampal-dependent fear conditioning. From a clinical perspective, our results identify eEF2K as a potential novel target for antiepileptic drugs, since pharmacological and genetic inhibition of eEF2K can revert the epileptic phenotype in a mouse model of human epilepsy.

Keywords: GABA receptors; epilepsy; fear conditioning; hippocampus; inhibitory synapses; translation elongation regulation.

MeSH terms

  • Animals
  • Cells, Cultured
  • Cerebral Cortex / drug effects
  • Cerebral Cortex / enzymology
  • Cerebral Cortex / pathology
  • Conditioning, Psychological / physiology
  • Disease Models, Animal
  • Elongation Factor 2 Kinase / antagonists & inhibitors
  • Elongation Factor 2 Kinase / genetics
  • Elongation Factor 2 Kinase / metabolism*
  • Epilepsy / enzymology*
  • Epilepsy / pathology
  • Fear / physiology
  • Hippocampus / drug effects
  • Hippocampus / enzymology
  • Hippocampus / pathology
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Neural Inhibition / drug effects
  • Neural Inhibition / physiology
  • Neurons / drug effects
  • Neurons / enzymology*
  • Neurons / pathology
  • Rats, Sprague-Dawley
  • Receptors, GABA-A / metabolism
  • Synapsins / genetics
  • Synapsins / metabolism
  • Synaptic Transmission / drug effects
  • Synaptic Transmission / physiology*
  • gamma-Aminobutyric Acid / metabolism

Substances

  • Gabra5 protein, mouse
  • Receptors, GABA-A
  • Synapsins
  • gamma-Aminobutyric Acid
  • Eef2k protein, rat
  • Eef2k protein, mouse
  • Elongation Factor 2 Kinase