THE CHARACTERISTICS OF STEM CELL DIFFERENTIATION IN HUMAN SKINS FROM DIFFERENT DEVELOPED STAGES AND THEIR EFFECTS ON SKIN WOUND REPAIR / 解放军医学杂志

ABSTRACT

To gain insight into the mechanisms of an age related difference in ability of wound healing, the characteristics of stem cell differentiation in skins from fetus, child and adult were investiga ted. Integrin ? 1 and keratin 19 (K19) were used as the biochemical markers for stem cells and transit amplifying cells. Biopsies were taken from fetus (22～24week gestational age), children (4～12year) and adults (35～53year). Immunohistochemistry was used. As for the immunostainings of fetal tissue sections, integrin ? 1 and K19 expressions were observed in all epidermal basal cells. In children skin, the ratio of integrin ? 1 and K19 positive cells in the epidermal basal layer was 60%～80%. In adults, the ratio in the epidermal layer decreased. These results indicate that fetal skin epidermis contains a large number of stem cells and transit amplifying cells, and the proportion of stem cells and transit amplifying cells decreases with age after birth, which maybe a reason of the age associated difference in ability of wound healing.