N-acetyl-cysteine abolishes hydrogen peroxide-induced modification of eukaryotic initiation factor 4F activity via distinct signalling pathways

Cell Signal. 2006 Jan;18(1):21-31. doi: 10.1016/j.cellsig.2005.03.013.

Abstract

During the oxidative stress generated by hydrogen peroxide (H2O2) in nerve growth factor (NGF)-differentiated PC12 cells, eIF4E binding protein (4E-BP1) and initiation factor 4E (eIF4E) phosphorylated levels decrease significantly, and an enhancement of the association of 4E-BP1 to eIF4E, which in turn decreases eIF4F formation is observed. The treatment with N-acetyl-cysteine (NAC) completely abolishes the H2O2-induced decrease in eIF4E phosphorylated levels, whereas the decrease in 4E-BP1 phosphorylated levels and eIF4F activity inhibition are significantly but not fully reversed. Rapamycin, the mammalian target of rapamycin (FRAP/mTOR) inhibitor, prevents the effect of NAC on H2O2-induced eIF4F complex formation inhibition. Besides the inhibitor induces a similar decrease in 4E-BP1 phosphorylated levels to that promote by H2O2. However, rapamycin has no effect on the NAC-induced recovery in phosphorylated eIF4E levels. Neither the MAP kinase inhibitors, PD98056 and SB203580, or the protein phosphatase 2A inhibitor, okadaic acid, mimic NAC effect on the H2O2-induced eIF4E dephosphorylation. Altogether our findings suggest that the effects caused by oxidative stress on eIF4s factors depends on two MAP kinase-independent signal transduction pathways, being at least one of them rapamycin-dependent.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetylcysteine / antagonists & inhibitors
  • Acetylcysteine / pharmacology*
  • Animals
  • Carrier Proteins / drug effects
  • Carrier Proteins / metabolism*
  • Eukaryotic Initiation Factor-4F / drug effects
  • Eukaryotic Initiation Factor-4F / metabolism*
  • Eukaryotic Initiation Factor-4G / drug effects
  • Eukaryotic Initiation Factor-4G / metabolism
  • Hydrogen Peroxide / antagonists & inhibitors*
  • Hydrogen Peroxide / pharmacology
  • Imidazoles / pharmacology
  • Intracellular Signaling Peptides and Proteins
  • Okadaic Acid / pharmacology
  • PC12 Cells
  • Phosphoproteins / drug effects
  • Phosphoproteins / metabolism*
  • Pyridines / pharmacology
  • Rats
  • Signal Transduction / drug effects
  • Signal Transduction / physiology*
  • Sirolimus / pharmacology

Substances

  • Carrier Proteins
  • Eif4ebp1 protein, rat
  • Eukaryotic Initiation Factor-4F
  • Eukaryotic Initiation Factor-4G
  • Imidazoles
  • Intracellular Signaling Peptides and Proteins
  • Phosphoproteins
  • Pyridines
  • Okadaic Acid
  • Hydrogen Peroxide
  • SB 203580
  • Sirolimus
  • Acetylcysteine