Nitric oxide stimulates Nrf2 nuclear translocation in vascular endothelium.
Vascular endothelial cells respond to nitric oxide by activating MAPK pathways and upregulating stress-activated proteins such as gamma-glutamylcysteine synthetase (gamma-GCS) and heme oxygenase-1 (HO-1). Since consensus sequences for the antioxidant response element (ARE) are found in the promoters of the gamma-GCS and HO-1 genes, we examined nuclear translocation of Nrf2, a CNC-bZIP protein which binds to and activates the ARE. We found a dramatic increase in Nrf2 nuclear translocation 1-8h following the nitric oxide donor spermine NONOate. Translocation was inhibited by pretreatment of cells with N-acetylcysteine suggesting involvement of an oxidative mechanism in this response. Translocation was also blocked by PD 98059 and SB 203580, inhibitors of ERK and p38 pathways, respectively. In addition to effects on Nrf2 subcellular localization, spermine NONOate increased Nrf2 protein levels by a mechanism which was inhibited by PD 98059. Pretreatment with N-acetylcysteine, PD 98059, and SB 203580 decreased HO-1 upregulation in spermine NONOate-treated cells. These results suggest that ERK and p38 pathways may regulate nitric oxide-mediated adaptive responses in vascular endothelium via translocation of Nrf2 and activation of the ARE.
Buckley
Barbara J
BJ
Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA. barbara.buckley@duke.edu
Marshall
Zermeena M
ZM
Whorton
A R
AR
D021581:Active Transport, Cell Nucleus / Q000187:drug effects; D000818:Animals; D002417:Cattle; D002467:Cell Nucleus / Q000378:metabolism*; D002478:Cells, Cultured; D004268:DNA-Binding Proteins / Q000378:metabolism*; D004730:Endothelium, Vascular / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006419:Heme Oxygenase (Decyclizing) / Q000096:biosynthesis; D051547:Heme Oxygenase-1; D020935:MAP Kinase Signaling System / Q000187:drug effects; D020928:Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D051267:NF-E2-Related Factor 2; D020030:Nitric Oxide Donors / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D009589:Nitrogen Oxides; D013096:Spermine / Q000031:analogs & derivatives* / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D015534:Trans-Activators / Q000378:metabolism*; D015854:Up-Regulation
D004268:DNA-Binding Proteins; D004791:Enzyme Inhibitors; D051267:NF-E2-Related Factor 2; D020030:Nitric Oxide Donors; D009589:Nitrogen Oxides; D015534:Trans-Activators; C091861:spermine nitric oxide complex; D013096:Spermine; D006419:Heme Oxygenase (Decyclizing); D051547:Heme Oxygenase-1; D020928:Mitogen-Activated Protein Kinases