title: Peroxynitrite signaling in human erythrocytes: synergistic role of hemoglobin oxidation and band 3 tyrosine phosphorylation.
abstract: Peroxynitrite crosses the red blood cell (RBC) membrane and reacts with hemoglobin (Hb) producing mainly metHb, which is reduced back to ferrousHb by NADH- and NADPH-dependent reductases. Peroxynitrite also induces band 3 (B3) tyrosine phosphorylation, a signaling pathway believed to activate glucose metabolism. This study was aimed to decipher the relationship between these two peroxynitrite-dependent processes. Peroxynitrite induced a burst of the hexose monophosphate shunt (HMS), revealed by NMR studies, and a burst of the glycolytic pathway, measured by lactate production. The HMS plays a prominent role in membrane signaling, as demonstrated by B3 phosphotyrosine inhibition by the glycolytic pathway inhibitor 2-deoxy-glucose (2DG) and activation by dehydroepiandrosterone (DHEA), an inhibitor of HMS. Peroxynitrite-induced B3 tyrosine phosphorylation was paralleled by the inhibition of membrane-associated phosphotyrosine phosphatase (PTP) activity, which was protected by 2DG but not DHEA. Interestingly, heme poisoning with CO inhibited peroxynitrite-dependent Hb oxidation and lactate production but did not affect PTP down regulation. These results suggest two distinct and concurrent effects of peroxynitrite: one mediated by Hb which, likely in its oxidized state, binds more strongly to B3, and another mediated by PTP-dependent B3 phosphorylation. Both effects are directed towards a surge in glucose utilization.
authors.affiliation: Section of Biomarkers in Degenerative Diseases, Department of cell Biology and Neurosciences, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Roma, Italy.
authors.forename: Alessio
authors.initials: A
authors.lastname: Metere
authors.forename: Egidio
authors.initials: E
authors.lastname: Iorio
authors.forename: Donatella
authors.initials: D
authors.lastname: Pietraforte
authors.forename: Franca
authors.initials: F
authors.lastname: Podo
authors.forename: Maurizio
authors.initials: M
authors.lastname: Minetti
mesh_terms: D001457:Anion Exchange Protein 1, Erythrocyte / Q000187:drug effects / Q000378:metabolism*; D002245:Carbon Dioxide / Q000494:pharmacology; D051545:Cyclooxygenase 1 / Q000097:blood; D004910:Erythrocyte Membrane / Q000187:drug effects / Q000378:metabolism; D004912:Erythrocytes / Q000187:drug effects / Q000378:metabolism*; D006801:Humans; D008055:Lipids / Q000097:blood; D008074:Lipoproteins / Q000097:blood; D008084:Lipoxygenase / Q000097:blood; D009569:Nitric Oxide / Q000494:pharmacology; D010108:Oxyhemoglobins / Q000378:metabolism*; D030421:Peroxynitrous Acid / Q000494:pharmacology*; D019000:Phosphotyrosine / Q000097:blood*
chemical_list: D001457:Anion Exchange Protein 1, Erythrocyte; D008055:Lipids; D008074:Lipoproteins; D010108:Oxyhemoglobins; D002245:Carbon Dioxide; D030421:Peroxynitrous Acid; D019000:Phosphotyrosine; D009569:Nitric Oxide; D008084:Lipoxygenase; D051545:Cyclooxygenase 1; C496511:PTGS1 protein, human