Lrig1 expression defines a distinct multipotent stem cell population in mammalian epidermis.
Lrig1 is a marker of human interfollicular epidermal stem cells and helps maintain stem cell quiescence. We show that, in mouse epidermis, Lrig1 defines the hair follicle junctional zone adjacent to the sebaceous glands and infundibulum. Lrig1 is a Myc target gene; loss of Lrig1 increases the proliferative capacity of stem cells in culture and results in epidermal hyperproliferation in vivo. Lrig1-expressing cells can give rise to all of the adult epidermal lineages in skin reconstitution assays. However, during homeostasis and on retinoic acid stimulation, they are bipotent, contributing to the sebaceous gland and interfollicular epidermis. beta-catenin activation increases the size of the junctional zone compartment, and loss of Lrig1 causes a selective increase in beta-catenin-induced ectopic hair follicle formation in the interfollicular epidermis. Our results suggest that Lrig1-positive cells constitute a previously unidentified reservoir of adult mouse interfollicular epidermal stem cells.
Jensen
Kim B
KB
Laboratory for Epidermal Stem Cell Biology, Wellcome Trust Centre for Stem Cell Research, University of Cambridge, Cambridge, UK.
Collins
Charlotte A
CA
Nascimento
Elisabete
E
Tan
David W
DW
Frye
Michaela
M
Itami
Satoshi
S
Watt
Fiona M
FM
D000818:Animals; D002454:Cell Differentiation; D019070:Cell Lineage; D049109:Cell Proliferation; D000078404:Epidermal Cells; D004817:Epidermis / Q000378:metabolism; D018859:Hair Follicle / Q000166:cytology / Q000378:metabolism; D008322:Mammals; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D008822:Mice, Transgenic; D039902:Multipotent Stem Cells / Q000166:cytology* / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism*; D016271:Proto-Oncogene Proteins c-myc / Q000235:genetics / Q000378:metabolism; D051176:beta Catenin / Q000378:metabolism
C101671:Lrig1 protein, mouse; D008562:Membrane Glycoproteins; D009419:Nerve Tissue Proteins; D016271:Proto-Oncogene Proteins c-myc; D051176:beta Catenin