Protein kinase A-mediated CREB phosphorylation is an oxidant-induced survival pathway in alveolar type II cells

Apoptosis. 2008 May;13(5):681-92. doi: 10.1007/s10495-008-0203-z.

Abstract

Oxidant stress plays a role in the pathogenesis of pulmonary diseases, including fibrotic lung disease and cancer. We previously found that hydrogen peroxide (H2O2) initiates an increase in Ca2+/cAMP-response element binding protein (CREB) phosphorylation in C10 alveolar type II cells that requires activation of extracellular regulated kinases 1/2 (ERK1/2). Here, we investigated the role of crosstalk between protein kinase A (PKA) and epidermal growth factor receptor (EGFR) in oxidant-induced signaling to ERK1/2 and CREB in C10 cells. Application of H2O2 increased nuclear accumulation of PKA, and inhibition of PKA with H89 reduced oxidant-mediated phosphorylation of both CREB and ERK1/2. Single cell measurements of cAMP and redox status, using a FRET-based biosensor and a redox-sensitive GFP, respectively, indicated that H2O2 increases production of cAMP that correlates with redox state. Inhibition of EGFR activity decreased both H2O2-induced CREB phosphorylation and translocation of PKA to the nucleus, suggesting that crosstalk between PKA and EGFR underlies the oxidant-induced CREB response. Furthermore, knockdown of CREB expression using siRNA led to a decrease in bcl-2 and an increase in oxidant-induced apoptosis. Together these data reveal a novel role for crosstalk between PKA, ERK1/2 and CREB that mediates cell survival during oxidant stress.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Apoptosis / physiology*
  • Butadienes / pharmacology
  • Cell Line
  • Cyclic AMP / biosynthesis
  • Cyclic AMP Response Element-Binding Protein / antagonists & inhibitors
  • Cyclic AMP Response Element-Binding Protein / metabolism*
  • Cyclic AMP-Dependent Protein Kinases / physiology*
  • Epidermal Growth Factor / pharmacology
  • ErbB Receptors / physiology
  • Glucose Oxidase / metabolism
  • Hydrogen Peroxide / pharmacology
  • Isoquinolines / pharmacology
  • Mice
  • Mitogen-Activated Protein Kinase 1 / metabolism
  • Mitogen-Activated Protein Kinase 3 / metabolism
  • Nitriles / pharmacology
  • Oxidants / pharmacology*
  • Phosphorylation
  • Pulmonary Alveoli / cytology
  • RNA, Small Interfering / pharmacology
  • Signal Transduction
  • Sulfonamides / pharmacology

Substances

  • Butadienes
  • Creb1 protein, mouse
  • Cyclic AMP Response Element-Binding Protein
  • Isoquinolines
  • Nitriles
  • Oxidants
  • RNA, Small Interfering
  • Sulfonamides
  • U 0126
  • Epidermal Growth Factor
  • Hydrogen Peroxide
  • Cyclic AMP
  • Glucose Oxidase
  • ErbB Receptors
  • Cyclic AMP-Dependent Protein Kinases
  • Mitogen-Activated Protein Kinase 1
  • Mitogen-Activated Protein Kinase 3
  • N-(2-(4-bromocinnamylamino)ethyl)-5-isoquinolinesulfonamide