title: Suppressive effect of ascorbic acid on the mutagenesis induced by the bystander effect through mitochondrial function.
abstract: Here, we focused on suppressive effect of ascorbic acid (AsA) on changes in mitochondrial function and mutagenesis by the radiation- induced bystander effect (RIBE). In mammalian cell lines, medium transfer assay was performed and conditioned medium including secreted factors after X-irradiation were examined to detect the RIBE. We found that the membrane potential and increased levels of superoxide radical (O2(-)) in mitochondria were modulated in cells treated with conditioned medium from irradiated cells. The result of the present study also demonstrated that increases in reactive oxygen species (ROS) levels led to the induction of gene mutations. Interestingly, the modulations in mitochondria, in addition to mutation inductions by RIBE, were completely suppressed by treatment with AsA in cells treated with conditioned medium. These results suggest that mutagenesis, which may have resulted from secreted factors involving the RIBE, may be induced by ROS that are localized in mitochondria and may be relieved by AsA.
authors.affiliation: Advanced Molecular Imaging Center, School of Medicine, Oita University, 1-1 Idaigaoka, Hasama-machi, Yufu city, Oita, Japan. kashino@oita-u.ac.jp
authors.forename: G
authors.initials: G
authors.lastname: Kashino
authors.forename: Y
authors.initials: Y
authors.lastname: Tamari
authors.forename: J
authors.initials: J
authors.lastname: Kumagai
authors.forename: K
authors.initials: K
authors.lastname: Tano
authors.forename: M
authors.initials: M
authors.lastname: Watanabe
mesh_terms: D000818:Animals; D001205:Ascorbic Acid / Q000737:chemistry / Q000494:pharmacology*; D024201:Bystander Effect / Q000528:radiation effects; D016466:CHO Cells; D002478:Cells, Cultured; D006224:Cricetinae; D003412:Cricetulus; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D008928:Mitochondria / Q000187:drug effects* / Q000378:metabolism*; D016296:Mutagenesis / Q000187:drug effects*; D010539:Permeability / Q000187:drug effects; D017382:Reactive Oxygen Species / Q000378:metabolism; D013481:Superoxides / Q000032:analysis / Q000378:metabolism
chemical_list: D017382:Reactive Oxygen Species; D013481:Superoxides; D001205:Ascorbic Acid