Project description:Despite epidermal turnover, the skin is host to a complex array of microbes including viruses, such as the human papillomavirus (HPV), which must infect and manipulate skin keratinocyte stem cells (KSC) to survive. This crosstalk between the virome and KSC populations remains largely unknown. Here, we investigated the effect of HPV8 on KSCs using various mouse models. We observed that the HPV8 early region gene E6 specifically caused Lrig1+hair follicle junctional zone KSC proliferation and expansion, which would facilitate viral transmission. Within Lrig1+KSCs specifically, HPV8 E6 bound intracellular p300 to phosphorylate the STAT3 transcriptional regulatory node. This induces a transcriptional switch from TAp63 to ΔNp63 expression, resulting in expansion of KSC into the overlying epidermis. HPV8 was associated with 70% of human actinic keratoses (AK). Together these results redefine human AK as an expansion of KSC, which lack protecting melanosomes and are thus susceptible to sun-light-induced malignant transformation.
Project description:Despite epidermal turnover, the skin is host to a complex array of microbes including viruses, such as the human papillomavirus (HPV), which must infect and manipulate skin keratinocyte stem cells (KSC) to survive. This crosstalk between the virome and KSC populations remains largely unknown. Here, we investigated the effect of HPV8 on KSCs using various mouse models. We observed that the HPV8 early region gene E6 specifically caused Lrig1+hair follicle junctional zone KSC proliferation and expansion, which would facilitate viral transmission. Within Lrig1+KSCs specifically, HPV8 E6 bound intracellular p300 to phosphorylate the STAT3 transcriptional regulatory node. This induces a transcriptional switch from TAp63 to ΔNp63 expression, resulting in expansion of KSC into the overlying epidermis. HPV8 was associated with 70% of human actinic keratoses (AK). Together these results redefine human AK as an expansion of KSC, which lack protecting melanosomes and are thus susceptible to sun-light-induced malignant transformation.
Project description:Mouse back skin was disassociated to single cells, sorted by cell surface markers and tested by microarrray To compare the gene expression of mouse bulge (CD34+CD200+CD49+) versus secondary hair germ (CD34-CD200+CD49+) versus interfollicular epidermis (CD34-CD200-CD49+) xx Bald scalp retains hair follicle stem cells but lacks CD200-rich and CD34-positive hair follicle progenitor cells Androgenetic alopecia (AGA) or common baldness results from a marked decrease in hair follicle size. This miniaturization may be related to loss of hair follicle stem or progenitor cells. To test this hypothesis, we analyzed bald and non-bald scalp from the same individuals for the presence of hair follicle stem and progenitor cells using flow cytometry to quantitate cells expressing CYTOKERATIN 15 (KRT15), CD200, CD34 and ALPHA-6-INTEGRIN (ITGA6). High levels of KRT15 expression correlated with stem cell properties of small cell size and quiescence. Cells with the highest level of KRT15 expression were maintained in bald scalp; however, distinct populations of CD200high ITGA6high cells and CD34-positive cells were markedly diminished. Consistent with a progenitor cell phenotype, the diminished populations localized closely to the stem-cell rich bulge area but were larger and more proliferative than the bulge stem cells. In functional assays, analogous CD200 high /Itga6 high cells from murine hair follicles were multipotent and generated new hair follicles in skin reconstitution assays. These findings suggest that a defect in stem cell activation plays a role in the pathogenesis of AGA. 4 independent biologic replicates (each pooled from 3 distinct mice) were sorted for Mouse bulge (CD34+CD200+CD49+) versus secondary hair germ (CD34-CD200+CD49+) versus interfollicular epidermis (CD34-CD200-CD49+)
Project description:RNA was isolated from fluorescence activated cell sorted (FACS) CD49f+/CD34+/GFP- hair follicle stem cells after hair follicle keratinocyte isolation from the skin of age matched saline or diphtheria toxin (DT) treated Lgr5-DTReGFP mice. The "SAMPLE_ID" sample characteristic is a sample identifier internal to Genentech. The ID of this project in Genentech's ExpressionPlot database is PRJ0009986
Project description:Mouse back skin was disassociated to single cells, sorted by cell surface markers and tested by microarrray To compare the gene expression of mouse bulge (CD34+CD200+CD49+) versus secondary hair germ (CD34-CD200+CD49+) versus interfollicular epidermis (CD34-CD200-CD49+) xx Bald scalp retains hair follicle stem cells but lacks CD200-rich and CD34-positive hair follicle progenitor cells Androgenetic alopecia (AGA) or common baldness results from a marked decrease in hair follicle size. This miniaturization may be related to loss of hair follicle stem or progenitor cells. To test this hypothesis, we analyzed bald and non-bald scalp from the same individuals for the presence of hair follicle stem and progenitor cells using flow cytometry to quantitate cells expressing CYTOKERATIN 15 (KRT15), CD200, CD34 and ALPHA-6-INTEGRIN (ITGA6). High levels of KRT15 expression correlated with stem cell properties of small cell size and quiescence. Cells with the highest level of KRT15 expression were maintained in bald scalp; however, distinct populations of CD200high ITGA6high cells and CD34-positive cells were markedly diminished. Consistent with a progenitor cell phenotype, the diminished populations localized closely to the stem-cell rich bulge area but were larger and more proliferative than the bulge stem cells. In functional assays, analogous CD200 high /Itga6 high cells from murine hair follicles were multipotent and generated new hair follicles in skin reconstitution assays. These findings suggest that a defect in stem cell activation plays a role in the pathogenesis of AGA.
Project description:Androgenetic alopecia (AGA) or common baldness results from a marked decrease in hair follicle size. This miniaturization may be related to loss of hair follicle stem or progenitor cells. To test this hypothesis, we analyzed bald and non-bald scalp from the same individuals for the presence of hair follicle stem and progenitor cells using flow cytometry to quantitate cells expressing CYTOKERATIN 15 (KRT15), CD200, CD34 and ALPHA-6-INTEGRIN (ITGA6). High levels of KRT15 expression correlated with stem cell properties of small cell size and quiescence. Cells with the highest level of KRT15 expression were maintained in bald scalp; however, distinct populations of CD200high ITGA6high cells and CD34-positive cells were markedly diminished. Consistent with a progenitor cell phenotype, the diminished populations localized closely to the stem-cell rich bulge area but were larger and more proliferative than the bulge stem cells. In functional assays, analogous CD200 high /Itga6 high cells from murine hair follicles were multipotent and generated new hair follicles in skin reconstitution assays. These findings suggest that a defect in stem cell activation plays a role in the pathogenesis of AGA. This SuperSeries is composed of the SubSeries listed below.
Project description:In most tissues, stem cells (SCs) comprise a heterogeneous cell population. Previous reports showed that slow cycling label-retaining cells (LRCs) are present in two prominent hair follicle SC populations, basal and suprabasal bulge SCs (bBSCs, sbBSCs). CD34+/itga6low sbBSC and neighbouring CD34+/itga6high bBSCs seem similar with both SC populations able to self-renew in vitro and to generate new hair follicles when grafted. Until now, functional differences have not been reported and molecular mechanisms underlying a positional encoded, intrinsic bulge SC heterogeneity and the relations to SC plasticity and tissue function are not well understood. Following fluorescence activated cell sorting for CD34 and integrin alpha6 of keratinocytes from 7 weeks old mice, we provide sequencing data for two prominent hair follicle SC populations, bBSC and sbBSC, suggesting distinct and overlapping functions in skin homeostasis.