Growth of Human Melanocytes in Human Epidermis Reconstructed by Culture

Cho, Kwang Hyun; Lee, Dong Youn; Yang, Seong Gyu; Yeo, Un Cheol; Park, Kyoung Chan; Youn, Jai Il

Abstract

BACKGROUND: Melanocytes grown in pure monolayer culure lack many of the cellular interactions that exist in vivo. This can be partially overcome by growing melanocytes together with other epidermal cells in skin equivalent models.
OBJECTIVE
The objective of the present study was to grow human melanocytes in human epidermis reconstructed on dermal substrates in vitro and to examine their response to UV radiation.
METHODS
The skin equivalents were prepared by seeding cultured human keratinocytes together with cultured human melanocytes(in a ratio of 5%) onto de-epidermized dermis. After 7 days of culture, they were exposed to UVB irradiation(total 150m J/cm over 5days). On day 12 of air exposure the sections of the skin equivalents were prepared for histology. The structure of the skin equivalents was studied following staining with hematoxylin and eosin. Melanocytes were characterized by DOPA staining and by immunohistochemistry.
RESULTS
Melanocytes were localized singly within the basal layer of the reconstructs. Melanin was also visible both in the melanocytes and in neighboring keratinocytes. There was an increase in melanocyte size and dendricity following UV irradiation. Melanocytes became positive to staining with HMB-45 antibody following UV irradiation.
CONCLUSION
Our results indicate that melanocytes grown in reconstructed human epidermis are functional and capable of responding to UV irradiation.