Glutamate-induced oxidative stress, but not cell death, is largely dependent upon extracellular calcium in mouse neuronal HT22 cells

Neurosci Lett. 2006 Jan 30;393(2-3):165-9. doi: 10.1016/j.neulet.2005.09.056. Epub 2005 Oct 17.

Abstract

Elucidating the relationship of glutamate-induced Ca2+ flux and oxidative death of neuronal cells may be of great relevance for neurodegenerative diseases in human beings. Mouse hippocampal HT22 cells provide a model system to study this relationship at the molecular level. Here we show that stimulation of HT22 cells with 5 mM glutamate is cytotoxic. Glutamate-induced cytotoxicity was associated with the generation of reactive oxygen species (ROS) and activation of the death executioner caspases 1 and 3. Treatment of HT22 cells with the calcium chelator, EGTA, and the calcium channel blocker, CoCl2, revealed that glutamate-induced cell death was dependent, in part, on glutamate-induced Ca2+ influx from extracellular stores. However, activation of caspases 1 and 3 and death of HT22 cells were also observed when Ca2+ was lacking in the extracellular milieu and ROS production abrogated. These findings led us to conclude that glutamate-induced death of mouse HT22 cells utilizes a complex mechanism that relies only in part on Ca2+ influx and ROS production. Additional studies are warranted to evaluate glutamate-induced death mechanisms that operate independently of Ca2+ influx and generation of ROS.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Calcium / metabolism*
  • Calcium Chloride / pharmacology
  • Caspase 3
  • Caspases / metabolism
  • Cell Count / methods
  • Cell Death / drug effects
  • Cell Line
  • Cell Survival / drug effects
  • Chelating Agents / pharmacology
  • Cobalt / pharmacology
  • Dose-Response Relationship, Drug
  • Drug Interactions
  • Egtazic Acid / pharmacology
  • Extracellular Space / drug effects
  • Extracellular Space / metabolism*
  • Glutamic Acid / pharmacology*
  • Mice
  • Neurons / drug effects*
  • Neurons / metabolism
  • Oligopeptides / metabolism
  • Oxidative Stress / drug effects*
  • Reactive Oxygen Species / metabolism

Substances

  • Chelating Agents
  • Oligopeptides
  • Reactive Oxygen Species
  • acetyl-aspartyl-glutamyl-valyl-aspartal
  • Cobalt
  • Glutamic Acid
  • Egtazic Acid
  • CASP3 protein, human
  • Casp3 protein, mouse
  • Caspase 3
  • Caspases
  • cobaltous chloride
  • Calcium Chloride
  • Calcium