Stammzellen und ihre Bedeutung in der Dermatologie

Abstract

Skin integrity is maintained by epidermal stem cells, which self-renew and generate daughter cells that undergo terminal differentiation. Existence of several distinct skin stem cell populations has been reported. Genetic labelling studies detected multipotent stem cells of the hair follicle, which support regeneration of hair follicles but is not responsible for maintaining interfollicular epidermis. The latter exhibits a distinct stem cell population. However, whenever skin integrity is severely compromised, e. g. after burns, hair follicle stem cells remodel epidermal regeneration. On the other hand, bulge cells, the first adult stem cells of the skin to have been identified, are capable of forming hair follicles, interfollicular epidermis and sebaceous glands. In addition - at least in mouse hair follicles - they can also give rise to non-epithelial cells, indicating a lineage-independent pluripotent character. Multipotent cells (skin-derived precursor cells) are present in human dermis. Dermal stem cells represent 0.3 % among human dermal foreskin fibroblasts. A resident pool of progenitor cells exists within the sebaceous glands, which is able to differentiate into both sebocytes and interfollicular epidermis. The self-renewal and multi-lineage differentiation of skin stem cells make these cells attractive for regenerative medicine, tissue repair, gene therapy and cell-based therapy with autologous adult stem cells.