Dermal Stem Cells the next
Skin renewal and regeneration depends on stem cells O
ur body’s tissue is subject to a continuous regeneration process. The ability of adult stem cells to self-renew and to generate fast proliferating progenitor cells is an absolute prerequisite for tissue
regeneration. Because the skin is an exceptionally highly regenerative tissue, the skin stem cell population represents the most important target for anti-ageing treatments. But, regardless of the regenerative power of stem cells, our skin loses its elasticity and firmness and forms wrinkles as we age. The regenerative potential of the stem cells apparently does not last forever; they too age. Ingredients, specifically designed to delay the depletion of their regeneration capacity, are a most promising solution to keeping skin looking youthful longer.
We are in need of novel in vitro models to test stem cell claims Meanwhile a lot of research is being done on the mechanism of epidermal regeneration by stem cells embedded in specific niches located at the basal layer of the epidermis. In vitro test systems using epidermal stem cells have been established which allow claims for epidermal stem cell actives. Also dermal stem cells could be targeted by cosmetic ingredients. Fibroblasts, the prominent cell type in the dermis, are responsible for the continuous production of collagen and elastin. These proteins form the so called extracellular matrix, a three dimensional structure that confer elasticity and firmness to the skin. Age-related reduction in the formation of the extracellular matrix and environmental stress factors that lead to the breakdown of the existing matrix are key elements in the skin ageing process and directly involved in wrinkle formation. Controlling the
Nuclei Sox2
regenerative potential of dermal stem cells would make it possible to correct loss of skin firmness and elasticity and to prevent wrinkles.
A novel cell culture assay to address dermal stem cell activity Details of the dermal stem cell niche and marker expression remained scarce. But recently, a research group at the University of Toronto showed that the dermal papilla is a niche for dermal progenitor/stem cells. These cells were found to self-renew, to induce the formation of hair follicles and to migrate into the inter-follicular dermis where they proliferated and differentiated to fibroblast cells, able to regenerate the extracellular matrix. Other characteristics of these cells were the expression of a specific marker gene Sox2 and the tendency to grow in colonies in the form of spheres. Mibelle Biochemistry is now working on a human dermal papilla cell line as a new test system for the evaluation of active ingredients for stem cell vitalization potential. The established cell line was found to effectively form sphere-like colonies and the cells in those spheres were found to be uniformly Sox2-labelled, thus representing real dermal stem cells.
Working with human dermal stem cells Progenitor cells isolated from the dermal papilla of excised human hair follicles could be maintained as a monolayer culture for at least 11 passages. At both passage 3 and passage 11 cells transferred into hanging drops formed 3D spheres, demonstrating that this important characteristic of progenitor cells was retained even after longer-term cultivation. In addition, immunofluorescent labelling of whole mount spheres showed
Nuclei Sox2
Spheres in control culture
Spheres in presence of an active ingredient
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