Blue light-induced oxidative stress in live skin.
Skin damage from exposure to sunlight induces aging-like changes in appearance and is attributed to the ultraviolet (UV) component of light. Photosensitized production of reactive oxygen species (ROS) by UVA light is widely accepted to contribute to skin damage and carcinogenesis, but visible light is thought not to do so. Using mice expressing redox-sensitive GFP to detect ROS, blue light could produce oxidative stress in live skin. Blue light induced oxidative stress preferentially in mitochondria, but green, red, far red or infrared light did not. Blue light-induced oxidative stress was also detected in cultured human keratinocytes, but the per photon efficacy was only 25% of UVA in human keratinocyte mitochondria, compared to 68% of UVA in mouse skin. Skin autofluorescence was reduced by blue light, suggesting flavins are the photosensitizer. Exposing human skin to the blue light contained in sunlight depressed flavin autofluorescence, demonstrating that the visible component of sunlight has a physiologically significant effect on human skin. The ROS produced by blue light is probably superoxide, but not singlet oxygen. These results suggest that blue light contributes to skin aging similar to UVA.
Department of Biochemistry and Cell Biology, Institute of Development and Aging Sciences, Graduate School of Medicine, Nippon Medical School, 1-396 Kosugi, Nakahara-ku, Kawasaki, Kanagawa 211-8533, Japan.
Yuya
Y
Nakashima
Department of Biochemistry and Cell Biology, Institute of Development and Aging Sciences, Graduate School of Medicine, Nippon Medical School, 1-396 Kosugi, Nakahara-ku, Kawasaki, Kanagawa 211-8533, Japan.
Shigeo
S
Ohta
Department of Biochemistry and Cell Biology, Institute of Development and Aging Sciences, Graduate School of Medicine, Nippon Medical School, 1-396 Kosugi, Nakahara-ku, Kawasaki, Kanagawa 211-8533, Japan. Electronic address: awolf@nms.ac.jp.
Alexander M
AM
Wolf
D019588:Aging, Premature / Q000209:etiology / Q000378:metabolism*; D000818:Animals; D002478:Cells, Cultured; D006801:Humans; D015603:Keratinocytes / Q000502:physiology / Q000528:radiation effects*; D008027:Light / Q000009:adverse effects*; D051379:Mice; D008812:Mice, Hairless; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D008928:Mitochondria / Q000378:metabolism / Q000528:radiation effects*; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D012867:Skin / Q000473:pathology / Q000528:radiation effects*; D013481:Superoxides / Q000737:chemistry / Q000378:metabolism
D013481:Superoxides
Aging; Fluorescence; GFP; Hydrogen peroxide; In vivo; Photoaging; Reactive oxygen species; Redox; Singlet; Superoxide