title: The peroxynitrite donor 3-morpholinosydnonimine activates Nrf2 and the UPR leading to a cytoprotective response in endothelial cells.
abstract: Endothelial dysfunction is associated with the formation of peroxynitrite, described to be toxic. Recent data also suggests that peroxynitrite is able to activate the protective Nrf2 pathway and/or the unfolded protein response (UPR). The aim of our work was to study the response of human endothelial cells to 3-morpholinosydnonimine (SIN-1), a peroxynitrite donor, and to highlight the possible protective roles of Nrf2 or the UPR pathway in this response. Immortal and primary human umbilical vein endothelial cells were exposed to SIN-1. SIN-1 incubation led to Nrf2 activation and to the overexpression of Nrf2-regulated genes, heme oxygenase-1 (HO-1) and NAD(P)H quinone oxidoreductase 1. We also demonstrated that this defensive response protected cells against cell death induced by serum starvation, by reducing apoptosis (monitored by caspase-3 activity and DNA fragmentation) and favoring autophagosome formation, as evidenced by LC3-II accumulation. Interestingly, we observed an activation of the UPR, with a rapid and significant overexpression of CHOP in serum starved cells stimulated with SIN-1. While siRNA mediated knockdown of CHOP had no effect on DNA fragmentation, the invalidation of Nrf2 or HO-1 by siRNA strongly increased DNA fragmentation, but also reinforced the SIN-1-induced LC3-II accumulation. This study shows that peroxynitrite, at least at sublethal concentrations and within a narrow concentration range, could exert protective effects on endothelial cells by modulating the balance between autophagy and apoptosis, through Nrf2-dependent pathways.
authors.affiliation: Research Unit of Cellular Biology, NARILIS (Namur Research Institute for Life Sciences), University of Namur (FUNDP), Namur, Belgium. laurine.mattart@fundp.ac.be
authors.forename: Laurine
authors.initials: L
authors.lastname: Mattart
authors.forename: Damien
authors.initials: D
authors.lastname: Calay
authors.forename: Dorothy
authors.initials: D
authors.lastname: Simon
authors.forename: Laura
authors.initials: L
authors.lastname: Roebroek
authors.forename: Laura
authors.initials: L
authors.lastname: Roebroeck
authors.forename: Ludmilla
authors.initials: L
authors.lastname: Caesens-Koenig
authors.forename: Martine
authors.initials: M
authors.lastname: Van Steenbrugge
authors.forename: Virginie
authors.initials: V
authors.lastname: Tevel
authors.forename: Carine
authors.initials: C
authors.lastname: Michiels
authors.forename: Thierry
authors.initials: T
authors.lastname: Arnould
authors.forename: Karim Zouaoui
authors.initials: KZ
authors.lastname: Boudjeltia
authors.forename: Martine
authors.initials: M
authors.lastname: Raes
mesh_terms: D001343:Autophagy; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism; D002470:Cell Survival; D019610:Cytoprotection; D053938:DNA Fragmentation; D042783:Endothelial Cells / Q000187:drug effects / Q000378:metabolism*; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation / Q000187:drug effects; D051547:Heme Oxygenase-1 / Q000235:genetics / Q000378:metabolism; D006801:Humans; D008981:Molsidomine / Q000031:analogs & derivatives* / Q000494:pharmacology; D016660:NAD(P)H Dehydrogenase (Quinone) / Q000235:genetics / Q000378:metabolism; D051267:NF-E2-Related Factor 2 / Q000235:genetics / Q000378:metabolism*; D016877:Oxidants / Q000494:pharmacology*; D030421:Peroxynitrous Acid / Q000494:pharmacology*; D021381:Protein Transport / Q000187:drug effects; D034622:RNA Interference; D015398:Signal Transduction; D051742:Transcription Factor CHOP / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic; D056811:Unfolded Protein Response
chemical_list: C497249:DDIT3 protein, human; D051267:NF-E2-Related Factor 2; C495635:NFE2L2 protein, human; D016877:Oxidants; D030421:Peroxynitrous Acid; D051742:Transcription Factor CHOP; C002385:linsidomine; D008981:Molsidomine; C496541:HMOX1 protein, human; D051547:Heme Oxygenase-1; D016660:NAD(P)H Dehydrogenase (Quinone); C447479:NQO1 protein, human