title: Protein kinase A-mediated CREB phosphorylation is an oxidant-induced survival pathway in alveolar type II cells.
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.
authors.affiliation: Department of Pharmacology, University of Vermont, 89 Beaumont Avenue, Burlington, VT 05405, USA.
authors.forename: Christy A
authors.initials: CA
authors.lastname: Barlow
authors.forename: Kajorn
authors.initials: K
authors.lastname: Kitiphongspattana
authors.forename: Nazli
authors.initials: N
authors.lastname: Siddiqui
authors.forename: Michael W
authors.initials: MW
authors.lastname: Roe
authors.forename: Brooke T
authors.initials: BT
authors.lastname: Mossman
authors.forename: Karen M
authors.initials: KM
authors.lastname: Lounsbury
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D002070:Butadienes / Q000494:pharmacology; D002460:Cell Line; D000242:Cyclic AMP / Q000096:biosynthesis; D017362:Cyclic AMP Response Element-Binding Protein / Q000037:antagonists & inhibitors / Q000378:metabolism*; D017868:Cyclic AMP-Dependent Protein Kinases / Q000502:physiology*; D004815:Epidermal Growth Factor / Q000494:pharmacology; D066246:ErbB Receptors / Q000502:physiology; D005949:Glucose Oxidase / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000494:pharmacology; D007546:Isoquinolines / Q000494:pharmacology; D051379:Mice; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism; D009570:Nitriles / Q000494:pharmacology; D016877:Oxidants / Q000494:pharmacology*; D010766:Phosphorylation; D011650:Pulmonary Alveoli / Q000166:cytology; D034741:RNA, Small Interfering / Q000494:pharmacology; D015398:Signal Transduction; D013449:Sulfonamides / Q000494:pharmacology
chemical_list: D002070:Butadienes; C492004:Creb1 protein, mouse; D017362:Cyclic AMP Response Element-Binding Protein; D007546:Isoquinolines; D009570:Nitriles; D016877:Oxidants; D034741:RNA, Small Interfering; D013449:Sulfonamides; C113580:U 0126; D004815:Epidermal Growth Factor; D006861:Hydrogen Peroxide; D000242:Cyclic AMP; D005949:Glucose Oxidase; D066246:ErbB Receptors; D017868:Cyclic AMP-Dependent Protein Kinases; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; C063509:N-(2-(4-bromocinnamylamino)ethyl)-5-isoquinolinesulfonamide