A non-ionotropic activity of NMDA receptors contributes to glycine-induced neuroprotection in cerebral ischemia-reperfusion injury

Sci Rep. 2017 Jun 15;7(1):3575. doi: 10.1038/s41598-017-03909-0.

Abstract

NMDA receptor (NMDAR) is known for its ionotropic function. But recent evidence suggests that NMDAR also has a non-ionotropic property. To determine the role of non-ionotropic activity of NMDARs in clinical relevant conditions, we tested the effect of glycine, a co-agonist of NMDARs, in rat middle cerebral artery occlusion (MCAO), an animal model of cerebral ischemia-reperfusion injury after the animals were injected with the NMDAR channel blocker MK-801 and the glycine receptor antagonist strychnine. We show that glycine reduces the infarct volume in the brain of ischemic stroke animals pre-injected with MK-801 and strychnine. The effect of glycine is sensitive to the antagonist of glycine-GluN1 binding site and blocked by Akt inhibition. In the neurobehavioral tests, glycine improves the functional recovery of stroke animals pre-injected with MK-801 and strychnine. This study suggests that glycine-induced neuroprotection is mediated in part by the non-ionotropic activity of NMDARs via Akt activation in cerebral ischemia-reperfusion injury.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Brain Ischemia / diagnosis
  • Brain Ischemia / metabolism*
  • Brain Ischemia / rehabilitation
  • Disease Models, Animal
  • Glutamic Acid / metabolism
  • Glutamic Acid / pharmacology
  • Glycine / metabolism*
  • Glycine / pharmacology
  • Male
  • Neuroprotection* / drug effects
  • Protein Binding
  • Protein Kinase Inhibitors / pharmacology
  • Proto-Oncogene Proteins c-akt / metabolism
  • Rats
  • Receptors, N-Methyl-D-Aspartate / metabolism*
  • Reperfusion Injury / diagnosis
  • Reperfusion Injury / etiology
  • Reperfusion Injury / metabolism*
  • Reperfusion Injury / rehabilitation
  • Severity of Illness Index

Substances

  • Protein Kinase Inhibitors
  • Receptors, N-Methyl-D-Aspartate
  • Glutamic Acid
  • Proto-Oncogene Proteins c-akt
  • Glycine