Characterization and isolation of stem cell-enriched human hair follicle bulge cells.
The human hair follicle bulge is an important niche for keratinocyte stem cells (KSCs). Elucidation of human bulge cell biology could be facilitated by analysis of global gene expression profiles and identification of unique cell-surface markers. The lack of distinctive bulge morphology in human hair follicles has hampered studies of bulge cells and KSCs. In this study, we determined the distribution of label-retaining cells to define the human anagen bulge. Using navigated laser capture microdissection, bulge cells and outer root sheath cells from other follicle regions were obtained and analyzed with cDNA microarrays. Gene transcripts encoding inhibitors of WNT and activin/bone morphogenic protein signaling were overrepresented in the bulge, while genes responsible for cell proliferation were underrepresented, consistent with the existence of quiescent noncycling KSCs in anagen follicles. Positive markers for bulge cells included CD200, PHLDA1, follistatin, and frizzled homolog 1, while CD24, CD34, CD71, and CD146 were preferentially expressed by non-bulge keratinocytes. Importantly, CD200+ cells (CD200hiCD24loCD34loCD71loCD146lo) obtained from hair follicle suspensions demonstrated high colony-forming efficiency in clonogenic assays, indicating successful enrichment of living human bulge stem cells. The stem cell behavior of enriched bulge cells and their utility for gene therapy and hair regeneration will need to be assessed in in vivo assays.
Ohyama
Manabu
M
Dermatology Branch, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, Maryland 20892, USA.
Terunuma
Atsushi
A
Tock
Christine L
CL
Radonovich
Michael F
MF
Pise-Masison
Cynthia A
CA
Hopping
Steven B
SB
Brady
John N
JN
Udey
Mark C
MC
Vogel
Jonathan C
JC
D015703:Antigens, CD / Q000032:analysis; D002455:Cell Division; D003114:Colony-Forming Units Assay; D018859:Hair Follicle / Q000166:cytology* / Q000276:immunology / Q000502:physiology*; D006801:Humans; D020411:Oligonucleotide Array Sequence Analysis; D012535:Scalp; D013234:Stem Cells / Q000166:cytology* / Q000276:immunology / Q000502:physiology*
D015703:Antigens, CD