Nitro-oxidative stress after neuronal ischemia induces protein nitrotyrosination and cell death

Abstract

This is an open access article distributed under the Creative Commons Attribution License.-- et al. ; Ischemic stroke is an acute vascular event that obstructs blood supply to the brain, producing irreversible damage that affects neurons but also glial and brain vessel cells. Immediately after the stroke, the ischemic tissue produces nitric oxide (NO) to recover blood perfusion but also produces superoxide anion. These compounds interact, producing peroxynitrite, which irreversibly nitrates protein tyrosines. The present study measured NO production in a human neuroblastoma (SH-SY5Y), a murine glial (BV2), a human endothelial cell line (HUVEC), and in primary cultures of human cerebral myocytes (HC-VSMCs) after experimental ischemia in vitro. Neuronal, endothelial, and inducible NO synthase (NOS) expression was also studied up to 24 h after ischemia, showing a different time course depending on the NOS type and the cells studied. Finally, we carried out cell viability experiments on SH-SY5Y cells with H2O2, a prooxidant agent, and with a NO donor to mimic ischemic conditions. We found that both compounds were highly toxic when they interacted, producing peroxynitrite. We obtained similar results when all cells were challenged with peroxynitrite. Our data suggest that peroxynitrite induces cell death and is a very harmful agent in brain ischemia. © 2013 Marta Tajes et al. ; This work was supported by the Spanish Ministry of Science and Innovation (SAF2012-38140; SAF 2009-10365); Fondo de Investigación Sanitaria (PI10/00587; FIS CP04-00112, FIS PS09/00664 and Red HERACLES RD12/0042/0014, RD12/0042/0016 and RD12/0042/0020); FEDER Funds; Generalitat de Catalunya (SGR05-266); and Fundació la Marató de TV3 (100310). Miguel A. Valverde is the recipient of an ICREA Academia Award. Dr. Ana M. Galán belongs to the Miguel Servet stabilization program of the Spanish Government's ISCIII research institute and "Direcció d'Estratègia i Coordinació del Departament de Salut" of the Generalitat de Catalunya. ; Peer Reviewed