Apoptosis and the receptor specificity of its mechanisms during the neurotoxic action of glutamate

Neurosci Behav Physiol. 2009 May;39(4):353-62. doi: 10.1007/s11055-009-9141-7. Epub 2009 Apr 2.

Abstract

The ratio of necrosis to apoptosis and the mechanisms of apoptosis were studied during neurodegeneration induced by glutamate and selective agonists of glutamate receptors - N-methyl-D-aspartate (NMDA) and kainate. Experiments were performed on primary cultures (seven days in vitro) of rat cerebral cortex neurons. Apoptosis and necrosis were identified using a vital fluorescence rapid test with staining with acridine orange and ethidium bromide. Immunocytochemistry in combination with confocal microscopy was used to visualize apoptotic proteins. Agonists (240 min) caused neuron death via both processes, though the proportion of necrotic cells when neurodegeneration was induced by NMDA and kainate was significantly less than when neurodegeneration was induced with glutamate. The neurotoxic effect of 3 mM glutamate was mediated via alpha-amino-3-(3-hydroxy-5-methylisoxazole-4-yl)propionate (AMPA) and kainate receptors, as it was blocked by 6-cyano-7-nitroquinoxalin-2,3-dione (CNQX). Activation of NMDA receptors led to the development of apoptosis without involvement of caspases, due to the direct action of apoptosis-inducing factor (AIF) on neuron nuclei. Activation of AMPA-kainate receptors was accompanied by the development of apoptosis via the caspase-dependent pathway. Thus, these data identified the receptor dependence of the mechanisms of apoptosis during the neurotoxic action of glutamate.

MeSH terms

  • 6-Cyano-7-nitroquinoxaline-2,3-dione / pharmacology
  • Active Transport, Cell Nucleus / drug effects
  • Animals
  • Apoptosis / drug effects*
  • Apoptosis Inducing Factor / metabolism
  • Caspase 3 / metabolism
  • Cell Nucleus / metabolism*
  • Cell Nucleus / pathology
  • Cells, Cultured
  • Cerebral Cortex / metabolism*
  • Cerebral Cortex / pathology
  • Dose-Response Relationship, Drug
  • Embryo, Mammalian / metabolism*
  • Embryo, Mammalian / pathology
  • Excitatory Amino Acid Agonists / toxicity
  • Excitatory Amino Acid Antagonists / pharmacology
  • Glutamic Acid / toxicity*
  • Kainic Acid / pharmacology
  • N-Methylaspartate / pharmacology
  • Necrosis / metabolism
  • Necrosis / pathology
  • Neurons / metabolism*
  • Neurons / pathology
  • Rats
  • Rats, Wistar
  • Receptors, Glutamate / metabolism*
  • Tumor Suppressor Protein p53 / metabolism

Substances

  • Aifm1 protein, rat
  • Apoptosis Inducing Factor
  • Excitatory Amino Acid Agonists
  • Excitatory Amino Acid Antagonists
  • Receptors, Glutamate
  • Tumor Suppressor Protein p53
  • Glutamic Acid
  • N-Methylaspartate
  • 6-Cyano-7-nitroquinoxaline-2,3-dione
  • Casp3 protein, rat
  • Caspase 3
  • Kainic Acid