title: Activation of flavin-containing oxidases underlies light-induced production of H2O2 in mammalian cells.
abstract: Violet-blue light is toxic to mammalian cells, and this toxicity has been linked with cellular production of H2O2. In this report, we show that violet-blue light, as well as UVA, stimulated H2O2 production in cultured mouse, monkey, and human cells. We found that H2O2 originated in peroxisomes and mitochondria, and it was enhanced in cells overexpressing flavin-containing oxidases. These results support the hypothesis that photoreduction of flavoproteins underlies light-induced production of H2O2 in cells. Because H2O2 and its metabolite, hydroxyl radicals, can cause cellular damage, these reactive oxygen species may contribute to pathologies associated with exposure to UVA, violet, and blue light. They may also contribute to phototoxicity often encountered during light microscopy. Because multiphoton excitation imaging with 1,047-nm wavelength prevented light-induced H2O2 production in cells, possibly by minimizing photoreduction of flavoproteins, this technique may be useful for decreasing phototoxicity during fluorescence microscopy.
authors.affiliation: Department of Physiology, Northwestern University Medical School, 303 East Chicago Avenue, Chicago, IL 60611, USA. p-hockberger@nwu.edu
authors.forename: P E
authors.initials: PE
authors.lastname: Hockberger
authors.forename: T A
authors.initials: TA
authors.lastname: Skimina
authors.forename: V E
authors.initials: VE
authors.lastname: Centonze
authors.forename: C
authors.initials: C
authors.lastname: Lavin
authors.forename: S
authors.initials: S
authors.lastname: Chu
authors.forename: S
authors.initials: S
authors.lastname: Dadras
authors.forename: J K
authors.initials: JK
authors.lastname: Reddy
authors.forename: J G
authors.initials: JG
authors.lastname: White
mesh_terms: D016475:3T3 Cells; D042962:Acyl-CoA Oxidase; D000818:Animals; D002460:Cell Line; D002522:Chlorocebus aethiops; D003593:Cytoplasm / Q000528:radiation effects / Q000648:ultrastructure; D004789:Enzyme Activation / Q000528:radiation effects; D006801:Humans; D006861:Hydrogen Peroxide / Q000378:metabolism*; D007425:Intracellular Membranes / Q000528:radiation effects / Q000648:ultrastructure; D008027:Light; D051379:Mice; D008830:Microbodies / Q000528:radiation effects* / Q000648:ultrastructure; D008928:Mitochondria / Q000528:radiation effects* / Q000648:ultrastructure; D008956:Models, Chemical; D010088:Oxidoreductases / Q000378:metabolism / Q000528:radiation effects*; D051381:Rats; D011994:Recombinant Proteins / Q000378:metabolism / Q000528:radiation effects; D014162:Transfection; D014466:Ultraviolet Rays; D014969:Xanthine Oxidase / Q000378:metabolism / Q000528:radiation effects*
chemical_list: D011994:Recombinant Proteins; D006861:Hydrogen Peroxide; D010088:Oxidoreductases; D014969:Xanthine Oxidase; D042962:Acyl-CoA Oxidase