De novo epidermal regeneration using human eccrine sweat gland cells: Higher competence of secretory over absorptive cells

In our previous work we showed that human sweat gland-derived epithelial cells represent an alternative source of keratinocytes to grow a near normal autologous epidermis. The role of subtypes of sweat gland cells in epidermal regeneration and maintenance remained unclear. In this study, we compare the regenerative potential of both, secretory and absorptive sweat gland cell subpopulations. We demonstrate the superiority of secretory over absorptive cells in forming a new epidermis on two levels: first, the proliferative and colony forming efficiencies in vitro are significantly higher for secretory cells, and secondly, secretory cells show a higher frequency of successful epidermis formation as well as an increase in thickness of the formed epidermis in the in vitro and in vivo functional analyses using a 3D dermo-epidermal skin model. However, the ability of forming functional skin substitutes is not limited to secretory cells, which supports the hypothesis that multiple subtypes of sweat gland epithelial cells hold regenerative properties, while the existence and exact localisation of a keratinocyte stem cell population in the human eccrine sweat gland remains elusive