P2.18 the Reconstruction of Skin Equivalents BY Hair Follicle Dermal Sheath Cells

Hye-Ryung Choi¹, Hyun-Ju Cho¹, Dong-Seok Kim², Sun-Bang Kwon¹, Sang-Woong Youn¹, Kyoung-Chan Park¹

¹ Department of Dermatology, ² Research Division for Human Life Sciences, Seoul National University College of Medicine, Seoul, South Korea

Objectives: The aim of this study is to investigate the effects of hair follicle dermal sheath cells (DSCs) upon the evolution of skin equivalents (SEs).

Methods: In this study, human keratinocytes were seeded on two different dermal substitutes. In addition, the effects of ascorbic acid were evaluated.

Results: Histologically, thick epidermis was observed in DSC-derived models. Immunohistochemical staining showed similar pattern of involucrin in both DSC- and fibroblast-derived models, but filaggrin was expressed more strongly in DSC models. The number of PCNA positive cells was lower in the DSC model than in the fibroblast model especially in the presence of ascorbic acid. However, integrin alpha 6 was strongly expressed in DSC models and in the presence of ascorbic acid supplementation. These findings suggest that DSCs secrete or synthesize factors, which affect the epidermalization of the skin, and that ascorbic acid is an important supplement in the reconstruction of human epidermis. In addition, transmission electron microscopy of SEs was performed and a well-developed intercellular junction was observed in the DSC models. Interestingly, numerous collagen bundles were also observed in the DSC models.

Conclusions: Our results suggest that dermal compartment-related epidermis modifications are important in the processes of differentiation and proliferation in SEs.