Intermittent hypoxia preconditioning-induced epileptic tolerance by upregulation of monocarboxylate transporter 4 expression in rat hippocampal astrocytes

Neurochem Res. 2014 Nov;39(11):2160-9. doi: 10.1007/s11064-014-1411-2. Epub 2014 Aug 22.

Abstract

Noxious stimuli applied at doses close to but below the threshold of cell injury induce adaptive responses that provide a defense against additional stress. Epileptic preconditioning protects neurons against status epilepticus and ischemia; however, it is not known if the converse is true. During hypoxia/ischemia (H/I), lactate released from astrocytes is taken up by neurons and is stored for energy, a process mediated by monocarboxylate transporter 4 (MCT4) in astroglia. The present study investigated whether H/I preconditioning can provide protection to neurons against epilepsy through upregulation of MCT4 expression in astrocytes in vitro and in vivo. An oxygen/glucose deprivation protocol was used in primary astrocyte cultures, while rats were subjected to an intermittent hypoxia preconditioning (IHP) paradigm followed by lithium-pilocarpine-induced epilepsy as well as lactate transportation inhibitor injection, with a subsequent evaluation of protein expression as well as behavior. H/I induced an upregulation of MCT4 expression, while an IHP time course of 5 days provided the greatest protection against epileptic seizures, which was most apparent by 3 days after IHP. However, lactate transport function disturbances can block the protective effect induced by IHP. These findings provide a potential basis for the clinical treatment of epilepsy.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Animals, Newborn
  • Astrocytes / metabolism*
  • Cells, Cultured
  • Epilepsy / metabolism*
  • Hippocampus / metabolism*
  • Hypoxia*
  • Ischemic Preconditioning / methods
  • Monocarboxylic Acid Transporters / metabolism*
  • Muscle Proteins / metabolism*
  • Neurons / metabolism*
  • Rats, Sprague-Dawley
  • Up-Regulation

Substances

  • Monocarboxylic Acid Transporters
  • Muscle Proteins
  • Slc16a3 protein, rat