title: Keratin 15 promoter targets putative epithelial stem cells in the hair follicle bulge.
abstract: Putative epithelial stem cells in the hair follicle bulge are thought to play pivotal roles in the homeostasis, aging, and carcinogenesis of the cutaneous epithelium. Elucidating the role of bulge cells in these processes has been hampered by the lack of gene promoters that target this area with specificity. Here we describe the isolation of the mouse keratin 15 (K15) promoter and demonstrate its utility for preferentially targeting hair follicle bulge cells in adult K15/lacZ transgenic mice. We found that patterns of K15 expression and promoter activity changed with age and correlated with levels of differentiation within the cutaneous epithelium; less differentiated keratinocytes in the epidermis of the neonatal mouse and in the bulge area of the adult mouse preferentially expressed K15. These findings demonstrate the utility of the K15 promoter for targeting epithelial stem cells in the hair follicle bulge and set the stage for elucidating the role of bulge cells in skin biology.
authors.affiliation: Department of Dermatology, Kligman Laboratories, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104, USA.
authors.forename: Yaping
authors.initials: Y
authors.lastname: Liu
authors.forename: Stephen
authors.initials: S
authors.lastname: Lyle
authors.forename: Zaixin
authors.initials: Z
authors.lastname: Yang
authors.forename: George
authors.initials: G
authors.lastname: Cotsarelis
mesh_terms: D000818:Animals; D002454:Cell Differentiation; D002455:Cell Division; D004847:Epithelial Cells / Q000166:cytology*; D018859:Hair Follicle / Q000166:cytology*; D006801:Humans; D053569:Keratin-15; D007633:Keratins / Q000235:genetics*; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D011401:Promoter Regions, Genetic; D012878:Skin Neoplasms / Q000209:etiology; D013234:Stem Cells / Q000502:physiology*; D014945:Wound Healing
chemical_list: C116015:KRT15 protein, human; D053569:Keratin-15; C492053:Krt15 protein, mouse; D007633:Keratins