Organotypic Culture of HaCaT cells: Use of Dermal Substrate that Combines de-epidermized Dermis with Fibroblast-populated Collagen Matrix

ABSTRACT

BACKGROUND: The immortalized human keratinocyte line, HaCaT cells have been widely used as substitutes for normal epidermal keratinocytes. Recently, reconstruction of a skin equivalent using HaCaT cells showed a multilayered epithelium,but somewhat different tissue architecture as compared with normal epidermis. OBJECTIVE: In this study, using HaCaT cells we tried to reconstruct an epidermis resembling more closely to normal epidermis than the previous results. MATERIALS AND METHODS: HaCaT cells were cultured in air-liquid interface on a recently developed dermal substrated in our laboratory, de-epidermized dermis (DED) raised on fibroblast-populated collagen matrix and the result was compared with those on DED or fibroblast-populated collagen matrix alone. RESULTS: HaCaT cells on the new dermal substrate formed a multilayered epithelium with rete ridges, showing rather orderly cellular organization compared with those on fibroblast-populated collagen matrix. However, horny and granular layers were not observed contrary to normal epidermis. Immunohistochemical studies revealed that differentiation markers such as keratin 1, keratin 6 and involucrin showed the similar pattern to those in HaCaT cells cultured on fibroblast-populated collagen matrix. Markers of terminal differentiation, loricrin and filaggrin were not expressed contrary to normal epidermis. CONCLUSION: These results suggest that organotypic culture HaCaT cells on the dermal substrate combines DED with fivroblast-populated collagen matrix results in incomplete differentiation of HaCaT cells contrary to normal keratinocytes.