Involvement of the transcription factor E2F1/Rb in kainic acid-induced death of murine cerebellar granule cells

Brain Res Mol Brain Res. 2003 Aug 19;116(1-2):70-9. doi: 10.1016/s0169-328x(03)00253-5.

Abstract

The full mechanisms underlying neuronal death following excitotoxic insult remain unclear, despite many in vivo and in vitro studies. Recent work has focused on various signaling molecules and pathways, normally strictly regulated, that can trigger death if perturbed. The transcription factor, E2F1 is pivotal in controlling cell death under stress situations. The current study aimed to investigate the role of this transcription factor in modulating neuronal death following kainic acid (KA) treatment of cultured mouse cerebellar granule cells (CGCs). KA-induced death of CGCs was attenuated by the selective KA/AMPA receptor antagonist CNQX, but not MK-801. Such neuronal death was caspase-3-independent and did not activate many known death genes, such as Fas receptor, caspase-8 and p38. However, hyperphosphorylation of Rb showed a transient increase which may lead to activation of E2F1. Indeed E2F1 +/+ and -/- CGCs showed a differential response to KA-mediated toxicity, in that E2F1 -/- neurons were significantly less susceptible to KA compared to E2F1 +/+ neurons, albeit both E2F1 +/+ and -/- neurons expressed similar levels of KA receptors and responded similarly to kainate antagonist, CNQX. Using selective inhibitors to CDKs, such as olomoucine, roscovitine and flavopiridol, and the inhibitor SB203580 to p38 MAPK, we ruled out the possibility that Rb inactivation through hyperphosphorylation was due to either upstream kinases. Therefore activation of Rb/E2F1 pathway appears to involve novel interactions yet to be elucidated.

Publication types

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

MeSH terms

  • 6-Cyano-7-nitroquinoxaline-2,3-dione / pharmacology
  • Animals
  • Blotting, Western
  • Cell Cycle Proteins*
  • Cell Death / drug effects*
  • Cell Survival / drug effects
  • Cells, Cultured
  • Cerebellum / cytology*
  • DNA-Binding Proteins*
  • Dizocilpine Maleate / pharmacology
  • Dose-Response Relationship, Drug
  • Drug Interactions
  • E2F Transcription Factors
  • E2F1 Transcription Factor
  • Enzyme Inhibitors / pharmacology
  • Excitatory Amino Acid Agonists / toxicity*
  • Excitatory Amino Acid Antagonists / pharmacology
  • Immunohistochemistry
  • Kainic Acid / toxicity*
  • MAP Kinase Kinase Kinases / metabolism
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Neurons / drug effects
  • Neurons / metabolism*
  • RNA, Messenger / biosynthesis
  • Receptors, Kainic Acid / classification
  • Receptors, Kainic Acid / metabolism
  • Retinoblastoma Protein / metabolism*
  • Reverse Transcriptase Polymerase Chain Reaction
  • Time Factors
  • Transcription Factors / metabolism*

Substances

  • Cell Cycle Proteins
  • DNA-Binding Proteins
  • E2F Transcription Factors
  • E2F1 Transcription Factor
  • E2f1 protein, mouse
  • Enzyme Inhibitors
  • Excitatory Amino Acid Agonists
  • Excitatory Amino Acid Antagonists
  • RNA, Messenger
  • Receptors, Kainic Acid
  • Retinoblastoma Protein
  • Transcription Factors
  • Dizocilpine Maleate
  • 6-Cyano-7-nitroquinoxaline-2,3-dione
  • MAP Kinase Kinase Kinases
  • Kainic Acid