title: Alopecia of IFN-gamma knockout mouse as a model for disturbance of the hair cycle: a unique arrest of the hair cycle at the anagen phase accompanied by mitosis.
abstract: Interferon-gamma(-/-) (IFN-gamma(-/-)) and IFN-gamma(+/+) C57BL/6 mice (3 weeks of age) completed the production of morphogenesis-derived hair. Around 6 weeks of age, however, most of the IFN-gamma(-/-) but none of the IFN-gamma(+/+) mice began to lose hairs in the dorsal and occipital areas in the absence of inflammatory reactions, and the alopecia was sustained for at least several 10-week periods of observation. A single subcutaneous injection of IFN-gamma to IFN-gamma(-/-) mice at 3, but not 4, 5, or 8 weeks of age could protect all the mice from alopecia, revealing that the lack of IFN-gamma around 3 weeks of age is directly responsible for the alopecia. Histologic features showed that the hair follicles of the IFN-gamma(+/+) mice passed through the anagen (4-5 weeks of age) and catagen/telogen ( approximately 6 weeks of age) phases, whereas those of IFN-gamma(-/-) mice (5 weeks of age or older) stayed in the anagen phase. TUNEL and bromodeoxyuridine experiments suggested that an arrest with unlimited DNA synthesis of the hair cycle in the anagen phase by the lack of IFN-gamma-dependent apoptosis in the midfollicle region and diffuse shedding of previously formed hair induced alopecia in IFN-gamma(-/-) mice.
authors.affiliation: Department of Physiology, Osaka Medical College, Takatsuki 569-8686, Japan.
authors.forename: Ryuichiro
authors.initials: R
authors.lastname: Hirota
authors.forename: Sadao
authors.initials: S
authors.lastname: Tajima
authors.forename: Yukio
authors.initials: Y
authors.lastname: Yoneda
authors.forename: Takumi
authors.initials: T
authors.lastname: Tamayama
authors.forename: Masahito
authors.initials: M
authors.lastname: Watanabe
authors.forename: Kouichi
authors.initials: K
authors.lastname: Ueda
authors.forename: Takahiro
authors.initials: T
authors.lastname: Kubota
authors.forename: Ryotaro
authors.initials: R
authors.lastname: Yoshida
mesh_terms: D000367:Age Factors; D000505:Alopecia / Q000188:drug therapy / Q000209:etiology* / Q000235:genetics / Q000503:physiopathology; D000818:Animals; D017209:Apoptosis / Q000502:physiology; D003433:Crosses, Genetic; D004261:DNA Replication; D005260:Female; D006197:Hair / Q000002:abnormalities*; D018859:Hair Follicle / Q000503:physiopathology*; D020287:In Situ Nick-End Labeling; D007371:Interferon-gamma / Q000172:deficiency / Q000235:genetics / Q000502:physiology* / Q000627:therapeutic use*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008938:Mitosis; D009024:Morphogenesis; D011994:Recombinant Proteins; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013047:Specific Pathogen-Free Organisms
chemical_list: D011994:Recombinant Proteins; D007371:Interferon-gamma