title: Human epithelial hair follicle stem cells and their progeny: current state of knowledge, the widening gap in translational research and future challenges.
abstract: Epithelial hair follicle stem cells (eHFSCs) are required to generate, maintain and renew the continuously cycling hair follicle (HF), supply cells that produce the keratinized hair shaft and aid in the reepithelialization of injured skin. Therefore, their study is biologically and clinically important, from alopecia to carcinogenesis and regenerative medicine. However, human eHFSCs remain ill defined compared to their murine counterparts, and it is unclear which murine eHFSC markers really apply to the human HF. We address this by reviewing current concepts on human eHFSC biology, their immediate progeny and their molecular markers, focusing on Keratin 15 and 19, CD200, CD34, PHLDA1, and EpCAM/Ber-EP4. After delineating how human eHFSCs may be selectively targeted experimentally, we close by defining as yet unmet key challenges in human eHFSC research. The ultimate goal is to transfer emerging concepts from murine epithelial stem cell biology to human HF physiology and pathology.
authors.affiliation: The Dermatology Centre, Salford Royal NHS Foundation Trust and Institute of Inflammation and Repair, University of Manchester, Manchester, United Kingdom.
authors.forename: Talveen S
authors.initials: TS
authors.lastname: Purba
authors.forename: Iain S
authors.initials: IS
authors.lastname: Haslam
authors.forename: Enrique
authors.initials: E
authors.lastname: Poblet
authors.forename: Francisco
authors.initials: F
authors.lastname: Jiménez
authors.forename: Alberto
authors.initials: A
authors.lastname: Gandarillas
authors.forename: Ander
authors.initials: A
authors.lastname: Izeta
authors.forename: Ralf
authors.initials: R
authors.lastname: Paus
mesh_terms: D000818:Animals; D004847:Epithelial Cells / Q000166:cytology*; D018859:Hair Follicle / Q000033:anatomy & histology / Q000166:cytology*; D006801:Humans; D023421:Models, Animal; D033581:Stem Cell Transplantation; D013234:Stem Cells / Q000166:cytology*; D057170:Translational Research, Biomedical
keywords: CD200; CD34; K15; K19; PHLDA1; bulge; human hair follicle stem cells