title: Igf1r signalling acts on the anagen-to-catagen transition in the hair cycle.
abstract: Insulin-like growth factor 1 (Igf1) is important for skin development and homoeostasis. However, overexpression and inactivation studies have produced variable findings regarding its role in hair follicle (HF) biology. Here, we studied a conditional and inducible knockout of the Igf1 receptor (Igf1r) in keratin 15-expressing bulge cells. Deletion of Igf1r after the development of the skin appendages in K15-Igf1rKOmice showed no abnormalities in epidermal homoeostasis. Numbers of bulge cells were lower in K15-Igf1rKOmice than in controls, without consequences on wound healing, at least in young mice. K15-Igf1rKOHFs entered anagen phase earlier than controls and showed a delay in the anagen/catagen switch. The expression of Bmp-4 mRNA was inhibited in HFs from K15-Igf1rKO. MED1 transcription was impaired in the epidermis of K15-Igf1rKOmice. These findings suggest that Igf1r controls the hair cycle, partly through Bmp-4 activation.
authors.affiliation: INSERM UMRS_938, Saint-Antoine Research Center, Paris, France.|UPMC Université Paris 6, Paris, France.
authors.forename: Mathieu
authors.identifier: 0000-0001-8745-9583
authors.initials: M
authors.lastname: Castela
authors.affiliation: INSERM UMRS_938, Saint-Antoine Research Center, Paris, France.|UPMC Université Paris 6, Paris, France.
authors.forename: Fabien
authors.initials: F
authors.lastname: Linay
authors.affiliation: INSERM UMRS_938, Saint-Antoine Research Center, Paris, France.|UPMC Université Paris 6, Paris, France.|Experimental Dermatology Group, UQ Centre for Clinical Research, The University of Queensland, Brisbane, QLD, Australia.
authors.forename: Edwige
authors.initials: E
authors.lastname: Roy
authors.affiliation: Department of Pathology, Hôpital Tenon AP-HP, Paris, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Moguelet
authors.affiliation: INSERM UMRS_938, Saint-Antoine Research Center, Paris, France.|UPMC Université Paris 6, Paris, France.
authors.forename: Jie
authors.initials: J
authors.lastname: Xu
authors.affiliation: INSERM UMRS_938, Saint-Antoine Research Center, Paris, France.|UPMC Université Paris 6, Paris, France.
authors.forename: Martin
authors.initials: M
authors.lastname: Holzenberger
authors.affiliation: Experimental Dermatology Group, UQ Centre for Clinical Research, The University of Queensland, Brisbane, QLD, Australia.
authors.forename: Kiarash
authors.initials: K
authors.lastname: Khosrotehrani
authors.affiliation: INSERM UMRS_938, Saint-Antoine Research Center, Paris, France.|Université Paris 5 Descartes, Paris, France.|Department of Dermatology, Hôpital Cochin, AP-HP, Paris, France.
authors.forename: Selim
authors.initials: S
authors.lastname: Aractingi
mesh_terms: D000818:Animals; D004817:Epidermis / Q000502:physiology; D006197:Hair / Q000254:growth & development*; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D008297:Male; D018345:Mice, Knockout; D017526:Receptor, IGF Type 1 / Q000235:genetics / Q000378:metabolism*
chemical_list: D007334:Insulin-Like Growth Factor I; D017526:Receptor, IGF Type 1
keywords: 
  Igf1r
  ; anagen; conditional gene targeting; hair cycle; stem cells