The nitrone spin trap PBN alters the cellular response to H(2)O(2): activation of the EGF receptor/ERK pathway.
The nitrone spin trap PBN has been shown to protect neuronal cells from reactive oxygen species both in culture and in vivo. As an approach to understanding the molecular mechanisms by which PBN may function to protect cells, we examined whether PBN alters the cellular response to reactive oxygen species. H(2)O(2) stimulation of PC-12 cells results in weak activation of both the ERK and JNK signal transduction pathways. PBN pretreatment of PC-12 cells, followed by H(2)O(2) stimulation, results in strong and selective activation of the pro-survival ERK pathway. H(2)O(2) induction of ERK activity in PBN-pretreated cells was shown to be dependent on extracellular Ca(+2) influx. Further analysis of the ERK pathway showed that in PBN-pretreated cells, EGF receptor and the adapter protein SHC were phosphorylated in a Ca(+2)-dependent, ligand-independent manner following H(2)O(2) stimulation. Interestingly, H(2)O(2) stimulation of PBN-pretreated cells results in only 30% of the increase in intracellular Ca(+2) as compared to untreated cells following H(2)O(2) stimulation. These data suggest a model in which PBN attenuates H(2)O(2)-induced Ca(+2) entry, yet magnifies or alters Ca(+2) action, resulting in the activation of the EGF receptor/ERK pathway.
Hassan
Waleed N
WN
Department of Biochemistry, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA 02111, USA.
Cantuti-Castelevetri
Ippolita
I
Denisova
Natalia A
NA
Yee
Amy S
AS
Joseph
James A
JA
Paulson
K Eric
KE
D048868:Adaptor Proteins, Signal Transducing; D033942:Adaptor Proteins, Vesicular Transport; D000818:Animals; D002118:Calcium / Q000378:metabolism; D003497:Cyclic N-Oxides; D004347:Drug Interactions; D004789:Enzyme Activation; D066246:ErbB Receptors / Q000378:metabolism*; D016166:Free Radical Scavengers / Q000494:pharmacology*; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D009589:Nitrogen Oxides / Q000494:pharmacology*; D016716:PC12 Cells; D010766:Phosphorylation / Q000187:drug effects; D011506:Proteins / Q000378:metabolism; D051381:Rats; D055765:Shc Signaling Adaptor Proteins; D000071425:Src Homology 2 Domain-Containing, Transforming Protein 1
D048868:Adaptor Proteins, Signal Transducing; D033942:Adaptor Proteins, Vesicular Transport; D003497:Cyclic N-Oxides; D016166:Free Radical Scavengers; D009589:Nitrogen Oxides; D011506:Proteins; D055765:Shc Signaling Adaptor Proteins; C528035:Shc1 protein, rat; D000071425:Src Homology 2 Domain-Containing, Transforming Protein 1; C029217:phenyl-N-tert-butylnitrone; D006861:Hydrogen Peroxide; D066246:ErbB Receptors; D020928:Mitogen-Activated Protein Kinases; D002118:Calcium