H2O2-induced phosphorylation of ERK1/2 and PKB requires tyrosine kinase activity of insulin receptor and c-Src

Antioxid Redox Signal. Jul-Aug 2005;7(7-8):1014-20. doi: 10.1089/ars.2005.7.1014.

Abstract

Hydrogen peroxide (H2O2) mimics many physiological responses of insulin, and increased H2O2 generation via the Nox-4 subunit of NAD(P)H oxidase was recently demonstrated to serve as a critical early step in the insulin signaling pathway. Exogenously added H2O2 has also been shown to activate several key components of the insulin signaling cascade. H2O2-induced signaling responses have been found to be associated with the activation of receptor and nonreceptor protein tyrosine kinases (PTK), including the insulin receptor (IR)-beta subunit. Therefore, in the present studies on Chinese hamster ovary cells overexpressing wild-type IR-PTK (CHO-IR) or a PTK-inactive form of IR (CHO-1018), we investigated whether IR-PTK plays a role in H2O2-induced signaling events. Treatment of CHO-IR cells with H2O2 increased the phosphorylation of extracellular signal-regulated kinases 1 and 2 (ERK1/2), protein kinase B (PKB), and glycogen synthase kinase-3beta while enhancing tyrosine phosphorylation of the IR-beta subunit and the p85 subunit of phosphatidylinositol 3-kinase (PI3K). Compared with CHO-IR cells, the stimulatory effect of H2O2 on ERK1/2 and PKB was partially reduced in CHO-1018 cells. However, pharmacological inhibition of Src family PTK by 4-amino-5-(4-chlorophenyl)-7-(tert-butyl)pyrazolo[3,4-d]pyrimidine (PP-2) almost completely blocked H2O2-stimulated phosphorylation of the p85 subunit of PI3K, ERK1/2, and PKB. Moreover, H2O2, but not insulin, induced Tyr-418 phosphorylation of Src, which was also suppressed by PP-2. Taken together, these data suggest that both IR-PTK and Src family PTKs contribute to H2O2-induced signaling in CHO-IR cells albeit IR-PTK has a less dominant role in this process.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Androstadienes / pharmacology
  • Animals
  • CHO Cells
  • Cricetinae
  • Extracellular Signal-Regulated MAP Kinases / metabolism*
  • Glycogen Synthase Kinase 3 / metabolism
  • Glycogen Synthase Kinase 3 beta
  • Hydrogen Peroxide / pharmacology*
  • Phosphatidylinositol 3-Kinases / metabolism
  • Phosphoinositide-3 Kinase Inhibitors
  • Phosphorylation / drug effects
  • Phosphotyrosine / metabolism
  • Protein Kinase Inhibitors / pharmacology
  • Protein Subunits / metabolism
  • Protein-Serine-Threonine Kinases / metabolism*
  • Proto-Oncogene Proteins / metabolism*
  • Proto-Oncogene Proteins c-akt
  • Proto-Oncogene Proteins pp60(c-src) / metabolism*
  • Receptor, Insulin / deficiency
  • Receptor, Insulin / genetics
  • Receptor, Insulin / metabolism*
  • Wortmannin

Substances

  • Androstadienes
  • Phosphoinositide-3 Kinase Inhibitors
  • Protein Kinase Inhibitors
  • Protein Subunits
  • Proto-Oncogene Proteins
  • Phosphotyrosine
  • Hydrogen Peroxide
  • Receptor, Insulin
  • Proto-Oncogene Proteins pp60(c-src)
  • Glycogen Synthase Kinase 3 beta
  • Protein-Serine-Threonine Kinases
  • Proto-Oncogene Proteins c-akt
  • Extracellular Signal-Regulated MAP Kinases
  • Glycogen Synthase Kinase 3
  • Wortmannin