Abstract
Epidermal lineage commitment occurs when multipotent stem cells are specified to three lineages: the epidermis, the hair follicle, and the sebaceous gland (SG). How and when a lineage becomes specified remains unknown. Here, we report the existence of a population of unipotent progenitor cells that reside in the SG and express the transcriptional repressor Blimp1. Using cell-culture studies and genetic lineage tracing, we demonstrate that Blimp1-expressing cells are upstream from other cells of the SG lineage. Blimp1 appears to govern cellular input into the gland since its loss leads to elevated c-myc expression, augmented cell proliferation, and SG hyperplasia. Finally, BrdU labeling experiments demonstrate that the SG defects associated with loss of Blimp1 lead to enhanced bulge stem cell activity, suggesting that when normal SG homeostasis is perturbed, multipotent stem cells in the bulge can be mobilized to correct this imbalance.
Publication types
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Research Support, N.I.H., Extramural
MeSH terms
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Animals
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Animals, Newborn
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Bromodeoxyuridine
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Cell Count
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Cell Differentiation / genetics*
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Cell Lineage / genetics*
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Cell Movement / genetics
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Cell Proliferation
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Cells, Cultured
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Epithelial Cells / cytology
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Epithelial Cells / metabolism*
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Gene Expression Regulation, Developmental / genetics
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Hair Follicle / cytology
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Hair Follicle / embryology
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Hair Follicle / growth & development
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Hyperplasia / genetics
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Hyperplasia / metabolism
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Hyperplasia / physiopathology
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Mice
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Mice, Knockout
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Mice, Transgenic
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Multipotent Stem Cells / cytology
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Multipotent Stem Cells / metabolism
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Positive Regulatory Domain I-Binding Factor 1
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Proto-Oncogene Proteins c-myc / metabolism
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Repressor Proteins / genetics
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Repressor Proteins / metabolism*
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Sebaceous Glands / cytology
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Sebaceous Glands / embryology*
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Sebaceous Glands / growth & development*
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Stem Cells / cytology
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Stem Cells / metabolism*
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Transcription Factors / genetics
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Transcription Factors / metabolism*
Substances
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Myc protein, mouse
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Prdm1 protein, mouse
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Proto-Oncogene Proteins c-myc
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Repressor Proteins
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Transcription Factors
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Positive Regulatory Domain I-Binding Factor 1
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Bromodeoxyuridine