Kainate mediates nuclear factor-kappa B activation in hippocampus via phosphatidylinositol-3 kinase and extracellular signal-regulated protein kinase

Academic Article

Abstract

  • The transcription factor nuclear factor-kappa B (NF-κB) is an inducible regulator of genes that plays a crucial role in the nervous system. Glutamate receptor stimulation is one well-described mechanism for NF-κB activation. In the studies presented here we used the glutamate analog, kainate to investigate the signaling mechanisms that couple to NF-κB activation in hippocampus. Kainate (250nM) application to hippocampal slices elicited a time-dependent increase in nuclear NF-κB levels in areas CA3 and CA1, but not dentate, compared with controls. Further analysis focused on hippocampal area CA3, revealed increased NF-κB DNA binding activity in response to kainate stimulation. Supershift electrophoretic mobility shift assay indicated that the kainate-mediated NF-κB complex binding DNA was composed of p65, p50, and c-Rel subunits. Through inhibition studies we found that extracellular signal-regulated protein kinase (ERK) and phosphatidylinositol-3 kinase (PI3K) couple to basal and kainate-mediated NF-κB DNA binding activity in area CA3. Kainate elicited decreased total and increased phospho-inhibitor kappa B alpha (IκBα), suggesting that kainate-mediated activation of NF-κB is via the classical IκB kinase pathway. Interestingly, inhibition of ERK but not PI3K blocked the kainate-mediated increase in phospho-IκBα. Thus, our findings support a role for the ERK and PI3K pathways in kainate-mediated NF-κB activation in hippocampal area CA3, but these kinases may target the NF-κB pathway at different loci. © 2005 Published by Elsevier Ltd on behalf of IBRO.
  • Authors

    Published In

  • Neuroscience  Journal
  • Digital Object Identifier (doi)

    Author List

  • Lubin FD; Johnston LD; Sweatt JD; Anderson AE
  • Start Page

  • 969
  • End Page

  • 981
  • Volume

  • 133
  • Issue

  • 4