Phenformin suppresses calcium responses to glutamate and protects hippocampal neurons against excitotoxicity

Jaewon Lee, Sic L. Chan, Chengbiao Lu, Mark A. Lane, Mark P. Mattson

Research output: Contribution to journalArticlepeer-review

Abstract

Phenformin is a biguanide compound that can modulate glucose metabolism and promote weight loss and is therefore used to treat patients with type-2 diabetes. While phenformin may indirectly affect neurons by changing peripheral energy metabolism, the possibility that it directly affects neurons has not been examined. We now report that phenformin suppresses responses of hippocampal neurons to glutamate and decreases their vulnerability to excitotoxicity. Pretreatment of embryonic rat hippocampal cell cultures with phenformin protected neurons against glutamate-induced death, which was correlated with reduced calcium responses to glutamate. Immunoblot analyses showed that levels of the N-methyl-D-aspartate (NMDA) subunits NR1 and NR2A were significantly decreased in neurons exposed to phenformin, whereas levels of the AMPA receptor subunit GluR1 were unchanged. Whole-cell patch clamp analyses revealed that NMDA-induced currents were decreased, and AMPA-induced currents were unchanged in neurons pretreated with phenformin. Our data demonstrate that phenformin can protect neurons against excitotoxicity by differentially modulating levels of NMDA receptor subunits in a manner that decreases glutamate-induced calcium influx. These findings show that phenformin can modulate neuronal responses to glutamate, and suggest possible use of phenformin and related compounds in the prevention and/or treatment of neurodegenerative conditions.

Original languageEnglish (US)
Pages (from-to)161-167
Number of pages7
JournalExperimental Neurology
Volume175
Issue number1
DOIs
StatePublished - 2002

Keywords

  • AMPA
  • Biguanide
  • Diabetes
  • Glutamate
  • Ischemic stroke
  • NMDA
  • Oxidative stress
  • Patch clamp

ASJC Scopus subject areas

  • Neurology
  • Neuroscience(all)

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