101 Hair Follicle Development in Organotypic Culture

M. Inamatsu1,3, M. Yamao2, S. Oomizu1, and K. Yoshizato1,3. Hiroshima Tissue Regeneration Project, Hiroshima Prefecture Collaboration of Regional Entities for the Advancement of Technological Excellence, JST, Hiroshima, Japan1, Bioart Laboratory, Hiroshima, Japan2, and Dept. of Biol. Sci., Grad. School of Sci., Hiroshima Univ., Hiroshima, Japan3

The dermal papilla (DP) plays a crucial role for the development of hair follicles through interacting with epidermal cells. In vitro model study is one of the approaches to identify principles associated with this interaction. In this study, we developed an organotypic culture as a skin model wherein the early phase of hair development can be reproduced. The skin was constructed by culturing keratinocytes of rat sole on the fibroblast-populated collagen gel. Freshly isolated DPs of rat vibrissae were inserted beneath the epidemal layer and the model was cultured at the air-liquid interface. At day 7 of culture, the epidermis adjacent to the DPs thickened and enclosed the DPs. On the other hand, no morphological change was observed in organotypic cultures inserted with aggregates of rat skin fibroblasts as the negative controls. It seems that intact DP interacted with keratinocytes and induced an initial morphological change of hair bulb formation under the culture condition. A similar change was seen in the model inserted with aggregates of DP cells.