损伤皮肤修复和伤口愈合过程中的干细胞：问题与前景

Stem cells in the skin regeneration and wound healing: problem and perspective

BACKGROUND:Present treatments for chronic skin wounds have certain limitations, and adult stem cells play a potential part in cutaneous repair and regeneration.OBJECTIVE:To review effects of stem cells in skin regeneration and wound healing.METHODS:The first author retrieved CNKI and Medline databases by computer for relevant articles published from 2000 to 2010. The keywords were “epidermal stem cells, hair follicle stem cells, stem cells, transplantation, dermal stem cells” in Chinese and in English, respectively. Then totally 489 papers were obtained after initial survey, and according to the inclusion criteria, 30 articles were selected for review. RESULTS AND CONCLUSION:Epidermal stem cells and other adult stem cells have been applied to treat wounds and other skin diseases. Epidermal stem cells are the crucial cell source of skin development, repair and remodeling. Epidermal stem cells are always in a resting state in vivo. Unless, skin injure or culture in vitro, cell division and proliferation will be significantly fastened. The stability of the epidermis mainly depends on the asymmetric division of a subpopulation, in which two daughter cells are produced, including one with characteristics of stem cells, and the other differentiated into transient amplifying cells that will be differentiated into post mitotic cells after a series of cell divisions (3-5 times). Afterwards, those post mitotic cells are developed into terminal differentiation cells on the basal layer, finally detach from the epidermis as dander. In addition, it is unclear whether epidermal factors are related to apoptosis, migration and differentiation in the process of wound repair and even under physiological conditions. Therefore, application of stem cells in wound healing requires a further discussion.