title: Low-dose gamma-ray irradiation induces translocation of Nrf2 into nuclear in mouse macrophage RAW264.7 cells.
abstract: The transcription factor nuclear erythroid-derived 2-related factor 2 (Nrf2) regulates expression of genes encoding antioxidant proteins involved in cellular redox homeostasis, while gamma-ray irradiation is known to induce reactive oxygen species in vivo. Although activation of Nrf2 by various stresses has been studied, it has not yet been determined whether ionizing irradiation induces activation of Nrf2. Therefore, we investigated activation of Nrf2 in response to gamma-irradiation in mouse macrophage RAW264.7 cells. Irradiation of cells with gamma-rays induced an increase of Nrf2 expression. Even 0.1 Gy of gamma-irradiation induced a translocation of Nrf2 from cytoplasm to the nucleus, indicating the activation of Nrf2 by low-dose irradiation. Expression of heme oxygenase-1, which is regulated by Nrf2, was also increased at 24 h after irradiation with more than 0.1 Gy of gamma-rays. Furthermore, the activation of Nrf2 was suppressed by U0126, which is an inhibitor of the extracellular signal regulated protein kinase 1/2 (ERK1/2) pathway, suggesting involvement of ERK1/2-dependent pathway in the irradiation-induced activation of Nrf2. Our results indicate that low-dose gamma-irradiation induces activation of Nrf2 through ERK1/2-dependent pathways.
authors.affiliation: Faculty of Pharmaceutical Sciences, Tokyo University of Science (TUS), Chiba, Japan. tsukim@rs.noda.tus.ac.jp
authors.forename: Mitsutoshi
authors.initials: M
authors.lastname: Tsukimoto
authors.forename: Nana
authors.initials: N
authors.lastname: Tamaishi
authors.forename: Takujiro
authors.initials: T
authors.lastname: Homma
authors.forename: Shuji
authors.initials: S
authors.lastname: Kojima
mesh_terms: D021581:Active Transport, Cell Nucleus / Q000528:radiation effects*; D000818:Animals; D002070:Butadienes / Q000494:pharmacology; D002467:Cell Nucleus / Q000378:metabolism / Q000528:radiation effects; D004307:Dose-Response Relationship, Radiation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D005720:Gamma Rays; D051547:Heme Oxygenase-1 / Q000096:biosynthesis; D008264:Macrophages / Q000528:radiation effects*; D051379:Mice; D008856:Microscopy, Fluorescence / Q000379:methods; D051267:NF-E2-Related Factor 2 / Q000378:metabolism*; D009570:Nitriles / Q000494:pharmacology; D015398:Signal Transduction; D013347:Subcellular Fractions / Q000378:metabolism
chemical_list: D002070:Butadienes; D004791:Enzyme Inhibitors; D051267:NF-E2-Related Factor 2; C495636:Nfe2l2 protein, mouse; D009570:Nitriles; C113580:U 0126; D051547:Heme Oxygenase-1; D048049:Extracellular Signal-Regulated MAP Kinases