Calcium channel and NMDA receptor activities differentially regulate nuclear C/EBPbeta levels to control neuronal survival

Neuron. 2003 Aug 14;39(4):625-39. doi: 10.1016/s0896-6273(03)00496-3.

Abstract

Insulin-like growth factor-1 (IGF-1) promotes the survival of cerebellar granule neurons by enhancing calcium influx through L-type calcium channels, whereas NMDA receptor-mediated calcium influx can lead to excitotoxic death. Here we demonstrate that L and NMDA receptor channel activities differentially regulate the transcription factor C/EBPbeta to control neuronal survival. Specifically, we show that L channel-dependent calcium influx results in increased CaMKIV activity, which acts to decrease nuclear C/EBPbeta levels. Conversely, NMDA receptor-mediated influx rapidly elevates nuclear C/EBPbeta and induces excitotoxic death via activation of the calcium-dependent phosphatase, calcineurin. Moderate levels of AMPA receptor activity stimulate L channels to improve survival, whereas higher levels stimulate NMDA receptors and reduce neuronal survival, suggesting differential synaptic effects. Finally, N-type calcium channel activity reduces survival, potentially by increasing glutamate release. Together, these results show that the L-type calcium channel-dependent survival and NMDA receptor death pathways converge to regulate nuclear C/EBPbeta levels, which appears to be pivotal in these mechanisms.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Apoptosis / physiology
  • Blotting, Western
  • CCAAT-Enhancer-Binding Proteins / biosynthesis*
  • Calcineurin / metabolism
  • Calcium Channels / physiology*
  • Calcium-Calmodulin-Dependent Protein Kinase Type 4
  • Cell Nucleus / physiology
  • Cells, Cultured
  • Cerebellum / physiology
  • Immunohistochemistry
  • In Situ Nick-End Labeling
  • Insulin-Like Growth Factor I / metabolism
  • Neurons / physiology*
  • Protein Kinases / physiology
  • Rats
  • Receptors, AMPA / physiology
  • Receptors, Glutamate / metabolism
  • Receptors, N-Methyl-D-Aspartate / physiology*
  • Signal Transduction / physiology*
  • Time Factors
  • Transcription Factor CHOP
  • Transcription Factors / biosynthesis*
  • Transfection

Substances

  • CCAAT-Enhancer-Binding Proteins
  • Calcium Channels
  • Ddit3 protein, rat
  • Receptors, AMPA
  • Receptors, Glutamate
  • Receptors, N-Methyl-D-Aspartate
  • Transcription Factors
  • Transcription Factor CHOP
  • Insulin-Like Growth Factor I
  • Protein Kinases
  • Calcium-Calmodulin-Dependent Protein Kinase Type 4
  • Camk4 protein, rat
  • Calcineurin