Pro-apoptotic signaling in neuronal cells following iron and amyloid beta peptide neurotoxicity

J Neurochem. 2003 Jul;86(1):114-25. doi: 10.1046/j.1471-4159.2003.01831.x.

Abstract

In a previous report, we characterized several oxidative stress parameters during the course of amyloid beta (Abeta) peptide/Fe2+-induced apoptotic death in neuronal cells. In extending these findings, we now report a marked decrease in protein kinase C (PKC) isoforms, reduced Akt serine/threonine kinase activity, Bcl 2-associated death promoter (BAD) phosphorylation and enhanced p38 mitogen-activated protein kinase (MAPK) and caspase-9 and -3 activation, 12 h after addition of both 5 micro m Abeta and 5 micro m Fe2+. These activities reminiscent for a pro-apoptotic cellular course were blocked in the presence of the iron chelator deferroxamine. Abeta alone, increased PKC isoform levels between three- and four-fold after 12 h, enhanced Akt activity approximately eight-fold and Ser136 BAD phosphorylation two-fold, suggesting that by itself is not toxic. Fe2+ alone transiently enhanced p38 MAPK and caspase-9 and -3 enzymes indicative for cell damage, but was not sufficient to cause cell death as previously indicated. GF, a PKC inhibitor or wortmannin, a blocker of the Akt pathway enhanced Abeta/Fe2+-induced toxicity, while SB, a p38 MAPK inhibitor, prevented cell damage and apoptosis. These findings further support the hypothesis that metal ion chelation and inhibitors of pro-apoptotic kinase cascades may be beneficial for Alzheimer's disease therapy.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amyloid beta-Peptides / toxicity*
  • Animals
  • Apoptosis* / drug effects
  • Carrier Proteins / metabolism
  • Caspases / metabolism
  • Cells, Cultured
  • Deferoxamine / pharmacology
  • Drug Synergism
  • Enzyme Inhibitors / pharmacology
  • Iron / toxicity*
  • Iron Chelating Agents / pharmacology
  • Isoenzymes / metabolism
  • Mitogen-Activated Protein Kinases / metabolism
  • Neurons / cytology
  • Neurons / drug effects*
  • Neurons / metabolism
  • Phosphorylation / drug effects
  • Protein Kinase C / metabolism
  • Protein Serine-Threonine Kinases*
  • Proto-Oncogene Proteins / metabolism
  • Proto-Oncogene Proteins c-akt
  • Rats
  • Signal Transduction / drug effects*
  • bcl-Associated Death Protein
  • p38 Mitogen-Activated Protein Kinases

Substances

  • Amyloid beta-Peptides
  • Bad protein, rat
  • Carrier Proteins
  • Enzyme Inhibitors
  • Iron Chelating Agents
  • Isoenzymes
  • Proto-Oncogene Proteins
  • bcl-Associated Death Protein
  • Iron
  • Akt1 protein, rat
  • Protein Serine-Threonine Kinases
  • Proto-Oncogene Proteins c-akt
  • Protein Kinase C
  • Mitogen-Activated Protein Kinases
  • p38 Mitogen-Activated Protein Kinases
  • Caspases
  • Deferoxamine