THE SIGNIFICANCE AND CHARACTERISTICS OF DISTRIBUTION OF EPIDERMAL STEM CELLS DURING WOUND HEALING PROCESS / 解放军医学杂志

ABSTRACT

To investigate the distribution of epidermal stem cells in regenerating wound tissues, and to elucidate the role of epidermal stem cells during wound repair. 80 circular full-thickness wounds were produced on both sides of the back in 20 male Wistar rats labeled 60 days previously with 5-Bromodeoxyuridine (BrdU) (4 wounds in each animal). Then these 80 wounds were randomly divided into 2 groups as follows group A with topical treatment of epidermal growth factor (n=40) and group B no-treatment (n=40). BrdU, ? 1 integrin and keratin19 (K19) were employed to determine the epidermal stem cells with streptavidin-peroxidase (SP)immunohistochemical method, and the speed and quality of epithelialization were determined with routine histological methods with HE staining on the 3rd, 7th, 14th, and 21st day after the wounding. Results showed that the healing rate of wounds was 80% in group A (32/40) and 60% in group B (24/40). No cells with positive immunostaining for BrdU, ? 1 integrin, or K19 were found in the granulation tissue of all wounds in both groups during the healing process. However, a few BrdU, ? 1 integrin and K19 positive cells, bearing no anatomic relation with the epidermal stem cells in the basal layer, were found scattering in the stratum spinosum and stratum granulosum of the epidermis on the wound edges. The results suggested that epidermal stem cells appearing on the wound edges were the main source of re-epithelialization of granulating wounds.