Figure 6.

Hair folliculogenesis induced by transplantation of murine DPCs (mDPCs) or murine DFs (mDFs) pretreated with VD₃ for 0, 24, or 72 hours. (A): Hair regeneration experiment using transplantation of a cultured mDPC construct in F344 rats. Cultured cell sheets of mDPCs (or mDFs as a control) were prepared and treated with VD₃ for 0, 24, or 72 hours. After VD₃ pretreatment, the mDPC (or mDF) sheet was fragmented, and the small fragment was transplanted into the nonhairy sole skin of F344 rats, using the hemivascularized sandwich method. Split-thickness skin (150–300 μm in thickness) was sliced off and digested with dispase, to separate the epidermis from the dermal compartment. The dermal compartment was discarded, and the epidermis was replaced on the remaining deep dermis after a cultured mDPC or mDF sheet fragment was grafted. Eight weeks after the transplantation, hair folliculogenesis was evaluated. (B): Hair regeneration induced by mDPC or mDF transplantation. Hair folliculogenesis of each sample was histologically evaluated (detailed data are summarized in supplemental online Table 3). Regenerated hair follicles were classified by maturity into stages 1–8. The numbers of total regenerated hair follicles (top left), matured (stage 6–8) follicles (top right), and outgrowing hairs (bottom) are shown. Significant differences among groups are shown as * (p < .05) or ** (p < .01). Abbreviations: DF, dermal fibroblast; DPC, dermal papilla cell; NS, not significant; VD₃, 1α,25-dihydroxyvitamin D₃.