Evolution of the clonogenic potential of human epidermal stem/progenitor cells with age

Abstract

A number of clinical observations have indicated that the regenerative potential and overall function of the epidermis is modified with age. The epidermis becomes thinner, repairs itself less efficiently after wounding, and presents modified barrier function recovery. In addition, the dermal papillae flatten out with increasing age, suggesting a modification in the interaction between epidermal and dermal compartments. As the epidermal regenerative capacity is dependent upon stem and progenitor cell function, it is naturally of interest to identify and understand age-related changes in these particular keratinocyte populations. Previous studies have indicated that the number of stem cells does not decrease with age in mouse models but little solid evidence is currently available concerning human skin. The objective of this study was to evaluate the clonogenic potential of keratinocyte populations isolated from the epidermis of over 50 human donors ranging from 18 to 71 years old. The data indicate that the number of epidermal cells presenting high regenerative potential does not dramatically decline with age in human skin. The authors believe that changes in the microenvironment controlling epidermal basal cell activity are more likely to explain the differences in epidermal function observed with increasing age.

Resveratrol Prevents Oxidative Stress-Induced Senescence and Proliferative Dysfunction by Activating the AMPK-FOXO3 Cascade in Cultured Primary Human Keratinocytes

“…Functional impairment of these stem cells is thought to contribute to age-related losses in the regenerative capacity of epidermis [ 55 , 56 ]. It has been postulated that this loss in regenerative capacity may be due to changes in the environment in the basal layer of the epidermis [ 57 ]. To mimic age-related changes in the epidermal microenvironment, primary keratinocytes from young donors were cultured in a growth factor-free medium.…”

Notch Cooperates with Survivin to Maintain Stemness and to Stimulate Proliferation in Human Keratinocytes during Ageing

“…While the number of KSC seems to persist throughout life [ 14 ], stem cell functions decline with age [ 15 ], and a reduced expression of some stem cell markers has been reported [ 16 ]. On the other hand, little is known on the behavior of either Notch or survivin in human skin during ageing.…”