title: Regeneration of Murine Hair Follicles is Inhibited by Low-Dose-Rate Gamma Irradiation.
abstract: To determine whether the effects of low-dose-rate gamma (γ) irradiation are identifiable in the regeneration of murine hair follicles, we irradiated whole bodies of C57BL/10JHir mice in the first telogen phase of the hair cycle with137Cs γ-rays. The mice were examined for effects on hair follicles, including number, morphology, and pigmentation in the second anagen phase. Effects of γ-radiation on melanocyte stem cells were also investigated by the indirect immunolabeling of tyrosinase-related protein 2 (TRP2). Irradiated skin showed a decrease in hair follicle density and the induction of curved hair follicles along with the presence of white hairs and hypopigmented hair bulbs. There was a small, but not significant, change in the number of TRP2-positive melanocyte stem cells in the hair bulge region of the irradiated skin. These results suggest that low-dose rate γ-irradiation does not deplete melanocyte stem cells, but can damage stem cells and progenitors for both keratinocytes and melanocytes, thereby affecting the structure and pigmentation of regenerated hair follicles in the 2ndanagen phase.
authors.affiliation: 1 Fukushima Project Headquarters, National Institute of Radiological Sciences, 4-9-1, Anagawa, Inage-ku, Chiba 263-8555, Japan.|2 Research Center for Radiation Protection, National Institute of Radiological Sciences,4-9-1, Anagawa, Inage-ku, Chiba 263-8555, Japan.
authors.forename: Kimihiko
authors.initials: K
authors.lastname: Sugaya
authors.affiliation: 1 Fukushima Project Headquarters, National Institute of Radiological Sciences, 4-9-1, Anagawa, Inage-ku, Chiba 263-8555, Japan.
authors.forename: Tomohisa
authors.initials: T
authors.lastname: Hirobe
authors.affiliation: 1 Fukushima Project Headquarters, National Institute of Radiological Sciences, 4-9-1, Anagawa, Inage-ku, Chiba 263-8555, Japan.|2 Research Center for Radiation Protection, National Institute of Radiological Sciences,4-9-1, Anagawa, Inage-ku, Chiba 263-8555, Japan.
authors.forename: Yoshie
authors.initials: Y
authors.lastname: Ishihara
authors.affiliation: 1 Fukushima Project Headquarters, National Institute of Radiological Sciences, 4-9-1, Anagawa, Inage-ku, Chiba 263-8555, Japan.
authors.forename: Sonoe
authors.initials: S
authors.lastname: Inoue
mesh_terms: D000818:Animals; D004307:Dose-Response Relationship, Radiation; D005720:Gamma Rays / Q000009:adverse effects*; D018859:Hair Follicle / Q000502:physiology* / Q000528:radiation effects*; D008544:Melanocytes / Q000528:radiation effects; D051379:Mice; D012038:Regeneration / Q000528:radiation effects*; D013234:Stem Cells / Q000528:radiation effects
keywords: hair cycle; keratinocyte; melanocyte; stem cell; γ-radiation