title: Peroxynitrite activates the phosphoinositide 3-kinase/Akt pathway in human skin primary fibroblasts.
abstract: Peroxynitrite is a potent oxidizing and nitrating species formed in a diffusion-limited reaction between nitrogen monoxide and superoxide. It induces apoptosis through unknown mechanisms and is believed to interfere with receptor tyrosine kinase signalling through nitration of tyrosine residues. One pathway emanating from receptor tyrosine kinases is that leading to activation of the anti-apoptotic kinase Akt. In the present study we provide evidence that peroxynitrite, administered to cells using two different delivery systems, results in the dose- and time-dependent activation of Akt. Akt activation is rapid and followed by phosphorylation of glycogen synthase kinase-3, an established substrate of Akt. Akt activation is inhibited in the presence of the phosphoinositide 3-kinase (PI-3K) inhibitors wortmannin and LY294002, and by treatment with the platelet-derived growth factor (PDGF) receptor (PDGFR) inhibitor AG1295, indicating a requirement for PDGFR and PI-3K in mediating peroxynitrite-induced Akt activation. Accordingly, the PDGFR-A and PDGFR-B isoforms were shown to undergo rapid tyrosine phosphorylation on treatment with peroxynitrite. Prior exposure of cells to peroxynitrite interferes with PDGF-induced Akt phosphorylation. Our findings suggest that Akt activation occurs as an acute response to peroxynitrite treatment and could play an important role in influencing cell survival and/or alter the cellular response to other growth regulatory signals.
authors.affiliation: Cell Stress and Aging Section, Laboratory of Biological Chemistry, National Institute on Aging, National Institutes of Health, 5600 Nathan Shock Drive, Baltimore, MD 21224-6825, USA.
authors.forename: L O
authors.initials: LO
authors.lastname: Klotz
authors.forename: S M
authors.initials: SM
authors.lastname: Schieke
authors.forename: H
authors.initials: H
authors.lastname: Sies
authors.forename: N J
authors.initials: NJ
authors.lastname: Holbrook
mesh_terms: D000730:Androstadienes / Q000494:pharmacology; D017209:Apoptosis; D015153:Blotting, Western; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000378:metabolism; D002478:Cells, Cultured; D002867:Chromones / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005347:Fibroblasts / Q000201:enzymology*; D038362:Glycogen Synthase Kinase 3; D038341:Glycogen Synthase Kinases; D006801:Humans; D008981:Molsidomine / Q000031:analogs & derivatives / Q000494:pharmacology; D009025:Morpholines / Q000494:pharmacology; D009566:Nitrates / Q000494:pharmacology*; D018384:Oxidative Stress; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism*; D010766:Phosphorylation; D011233:Precipitin Tests; D020033:Protein Isoforms; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D011518:Proto-Oncogene Proteins; D051057:Proto-Oncogene Proteins c-akt; D017479:Receptors, Platelet-Derived Growth Factor / Q000737:chemistry / Q000378:metabolism; D015398:Signal Transduction; D012867:Skin / Q000201:enzymology*; D013997:Time Factors; D014443:Tyrosine / Q000378:metabolism; D020032:Tyrphostins / Q000494:pharmacology; D000077191:Wortmannin
chemical_list: D000730:Androstadienes; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D002867:Chromones; D004791:Enzyme Inhibitors; D038362:Glycogen Synthase Kinase 3; D038341:Glycogen Synthase Kinases; D008981:Molsidomine; D009025:Morpholines; D009566:Nitrates; D019869:Phosphatidylinositol 3-Kinases; D020033:Protein Isoforms; D017346:Protein Serine-Threonine Kinases; D011518:Proto-Oncogene Proteins; D051057:Proto-Oncogene Proteins c-akt; D017479:Receptors, Platelet-Derived Growth Factor; D014443:Tyrosine; D020032:Tyrphostins; D000077191:Wortmannin; C407689:6,7-dimethoxy-2-phenylquinoxaline; C039642:peroxynitric acid; C085911:2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one; C002385:linsidomine; C494918:AKT1 protein, human