Skin stem and progenitor cells: using regeneration as a tissue-engineering strategy.
ABSTRACT Cell plasticity and mesenchymal-epithelial interactions are regarded as a hallmark of embryonic development and are not believed to occur extensively in the adult. Recently, adult mesenchymal stem cells were reported to differentiate in culture into a variety of mature cell types, including epithelial cells. Progress in stem and progenitor cell biology and recognition of the unique properties of such cells may enable intelligent bioengineering design of replacement skin which allows regeneration to occur in vivo. Ideally, a scaffold-free environment which stimulates skin stem cells in situ to initiate cell signals that result in regeneration rather than scar formation is required. Various skin progenitor cell types are considered along with the signalling cascades that they affect. We also discuss a mammalian model of scar-free regeneration. Many of these mechanisms, if fully understood, could be harnessed after injury to perfectly restore the skin.
- SourceAvailable from: europepmc.org[show abstract] [hide abstract]
ABSTRACT: Epidermal stem cells have become an object of intensive research. The epidermis constitutes one of the main sources of stem cells and is a tissue of choice for use in exploring their biology. Stratified squamous epithelium (epidermis) possesses the capacity for self-renewal and repair due to the presence of epidermal stem cells (ESC). They have been identified within basal layer of the interfollicular epidermis (IFE), in the "bulge" of the hair follicles of rodents, and also in the human follicular bulge. Melanocyte stem cells (MSC) from hair follicles (precisely from the bulge region, which also contains epidermal stem cells) provide an attractive model for the study of stem cells and their regulation at the niche. This review summarizes the rapidly developing field of epidermal stem cell research and their application in regenerative medicine, paying particular attention to melanocyte stem cells, their biology and some of the processes that occur during hair graying and regeneration of the pigmentary system, as well as discussing how aged-associated changes in the melanocyte stem cells compartment impact hair graying. This review also includes differentiation of human skin stem cells into functional epidermal melanocytes.Medical science monitor: international medical journal of experimental and clinical research 10/2012; 18(10):RA155-159. · 1.36 Impact Factor
- [show abstract] [hide abstract]
ABSTRACT: Scar is the default tissue repair used by the body in response to most injuries-a response that occurs in wounds ranging in seriousness from minor skin cuts to complete severance of the spinal cord. By contrast, before the third trimester of pregnancy embryonic mammals tend to heal without scarring due to a variety of mechanisms and factors that are uniquely in operation during development in utero. The goal of tissue engineering is to develop safe and clinically effective biological substitutes that restore, maintain, or improve tissue function in patients. This review provides a comparative overview of wound healing during development and maturation and seeks to provide a perspective on just how much the embryo may be able teach us in the engineering of new therapies for tissue repair. Birth Defects Research (Part C) 96:258-270, 2012. © 2012 Wiley Periodicals, Inc.Birth Defects Research Part C Embryo Today Reviews 09/2012; 96(3):258-70. · 4.44 Impact Factor
- [show abstract] [hide abstract]
ABSTRACT: Reprogramming of somatic cells into inducible pluripotent stem cells (iPSCs) provides an alternative to using embryonic stem cells (ESCs). Mesenchymal stem cells derived from human hair follicles (hHF-MSCs) are easily accessible, reproducible by direct plucking of human hairs. Whether these hHF-MSCs can be reprogrammed has not been previously reported. Here we report the generation of iPSCs from hHF-MSCs obtained by plucking several hairs. hHF-MSCs were isolated from hair follicle tissues and their mesenchymal nature confirmed by detecting cell surface antigens and multilineage differentiation potential towards adipocytes and osteoblasts. They were then reprogrammed into iPSCs by lentiviral transduction with Oct4, Sox2, c-Myc and Klf4. hHF-MSC-derived iPSCs appeared indistinguishable from human embryonic stem cells (hESCs) in colony morphology, expression of alkaline phosphotase, and expression of specific hESCs surface markers, SSEA-3, SSEA-4, Tra-1-60, Tra-1-81, Nanog, Oct4, E-Cadherin and endogenous pluripotent genes. When injected into immunocompromised mice, hHF-MSC-derived iPSCs formed teratomas containing representatives of all three germ layers. This is the first study to report reprogramming of hHF-MSCs into iPSCs.Stem cell reviews 12/2012; · 5.08 Impact Factor