Recent Results in Cancer Research, vol 128 Lin HY(1), Yang LT. Many of the answers are still not in, but hints have begun to emerge in the past five years. Surprisingly, hair follicle stem cells that are responsible for hair regeneration maintained expression of stem cell markers but exhibited significantly reduced proliferation. Epub 2015 Jul 28. Elucidating the role of bulge cells in these processes has been hampered by the lack of gene promoters that target this area with specificity. It Hair follicle stem cells (HFSCs) are noted for their relative quiescence and therefore can be distinguished from other cells by their differential history of cell division. , 1994 ; Ito et al. Hair follicles have a niche for mature stem cells—hair follicular stem cells (HFSCs)—a so-called “bulge” in the attachment region of arrector pili muscles, which contain epithelial and melanocyte stem cells. Niche architecture becomes pronounced postnatally at the start of the first hair cycle. Most epithelial tissues self-renew throughout adult life due to the presence of multipotent stem cells and/or unipotent progenitor cells. Dermal papilla (DP) cells are recognized as the key inductive mesenchymal player, but the ideal source of receptive keratinocytes for human HF regeneration is yet to be defined. We ¢rst localized putative epithelial stem cells as LRC to the hair follicle bulge of both mouse and Hair follicle stem cells (HFSCs) are noted for their relative quiescence and therefore can be distinguished from other cells by their differential history of cell division. Murine epidermal stem cells located at the bulge region are responsible for replenishing the hair lineage, while … 2008; 3:33–43. Finally, we demonstrate that epidermal Wnt ligands are critical for adult wound-induced de novo hair formation. We herein investigated whether human interfollicular epidermal keratinocytes with stem … [PMC free article] … Stem cell activity is subject to non-cell-autonomous regulation from the local microenvironment, or niche. The epithelial stem cells, when implanted into immunocompromised mice, regenerated the different cell types of human skin and hair follicles, and even produced structurally recognizable hair … P. A. de Viragh, M. Meuli, Human scalp hair follicle development from birth to adulthood: Statistical study with special regard to putative stem cells in the bulge and proliferating cells in the matrix, Archives of Dermatological287, Putative epithelial stem cells in the hair follicle bulge are thought to play pivotal roles in the homeostasis, aging, and carcinogenesis of the cutaneous epithelium. Epidermal stem cells residing in different locations in the skin continuously self-renew and differentiate into distinct cell lineages to maintain skin homeostasis during postnatal life. Hair cycling, the repeated regeneration of hair follicles to produce new hair shafts over the lifetime of the organism, is a useful model by which to study stem cell properties. What coaxes stem cells to become hair follicles rather than epidermis is one of the most fascinating questions in the skin stem cell field. P. A. de Viragh, M. Meuli, Human scalp hair follicle development from birth to adulthood: Statistical study with special regard to putative stem cells in the bulge and proliferating cells in the matrix, Archives of Dermatological287, Putative epithelial stem cells were identified in the hair follicle bulge as quiescent “label retaining cells”. Despite being partially differentiated, clonal populations of suprabasal bulge region cells can regenerate skin and hair follicles as well as a new stem cell niche. The hair follicle undergoes lifelong cycling and growth. Adult stem cells are essential for tissue renewal, regeneration, and repair, and their expansion in culture is of paramount importance for regenerative medicine. (1993) Epithelial Stem Cells, Hair Follicles, and Tumor Formation. In adult skin, epithelial hair follicle stem cells (SCs) reside in a quiescent niche and are essential for cyclic bouts of hair growth. Differential response of epithelial stem cell populations in hair follicles to TGF-β signaling. from epithelial stem cells (reviewed in Morris, 2000), thus the abil-ity to target these cells is important for studying carcinogenesis. Methods: In this study, we have developed a new method to isolate human adult stem cells by mechanical centrifugation of punch biopsy from human hair follicles without culture condition. In the human fetus, hair follicles develop from small collections of cells, called epithelial placodes, which correspond to stage 1 of hair follicle development and first appear around 10 weeks’ gestation (see Fig. Hair follicles undergo lifelong growth and hair cycle is a well-controlled process involving stem cell proliferation and quiescence. (2004) have shown that two subpopulations of cells exist within the hair follicle stem cell niche. Whether SCs exist or function earlier is unknown. Early evidence supporting the concept that bulge cells generate the lower follicle includes proliferation studies showing that bulge cells preferentially proliferate at anagen onset ( Wilson et al. Cell Stem Cell. Nowak JA, Polak L, Pasolli HA, Fuchs E. Hair follicle stem cells are specified and function in early skin morphogenesis. ) have shown that two subpopulations of cells exist within the epithelial stem cell field follicles reconstitute themselves though hair... 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