1?,25-Dihydroxyvitamin D3 Modulates the Hair-Inductive Capacity of Dermal Papilla Cells: Therapeutic Potential for Hair Regeneration
Noriyuki Aoia, Keita Inouea, Toshihiro Chikanishib,c, Ryoji Fujikic, Hanako Yamamotod, Harunosuke Katoa, Hitomi Etoa, Kentaro Doia, Satoshi Itamie, Shigeaki Katob,c and Kotaro Yoshimuraa
a Department of Plastic Surgery and
d Department of Biochemistry and Molecular Biology, University of Tokyo School of Medicine, Tokyo, Japan;
b ERATO, Japan Science and Technology Agency, Saitama, Japan;
c Institute of Molecular and Cellular Biosciences, University of Tokyo, Tokyo, Japan;
e Department of Regenerative Dermatology, Osaka University Graduate School of Medicine, Suita-shi, Japan
Correspondence: Kotaro Yoshimura, M.D., Department of Plastic Surgery, University of Tokyo School of Medicine, 7-3-1, Hongo, Bunkyo-Ku, Tokyo 113-8655, Japan. Telephone: 81-3-5800-8948; Fax: 81-3-5800-8947; e-mail: kotaro-yoshimura at umin.ac.jp
Received March 27, 2012, Accepted June 18, 2012.
Dermal papilla cells (DPCs) have the potential to induce differentiation of epithelial stem cells into hair, and Wnt signaling is deeply involved in the initiation process. The functional limitation of expanded adult DPCs has been a difficult challenge for cell-based hair regrowth therapy. We previously reported that 1?,25-dihydroxyvitamin D3 (VD3) upregulates expression of transforming growth factor (TGF)-?2 and alkaline phosphatase (ALP) activity, both features of hair-inducing human DPCs (hDPCs). In this study, we further examined the effects and signaling pathways associated with VD3 actions on DPCs. VD3 suppressed hDPC proliferation in a dose-dependent, noncytotoxic manner. Among the Wnt-related genes investigated, Wnt10b expression was significantly upregulated by VD3 in hDPCs. Wnt10b upregulation, as well as upregulation of ALPL (ALP, liver/bone/kidney) and TGF-?2, by VD3 was specific in hDPCs and not detected in human dermal fibroblasts. Screening of paracrine or endocrine factors in the skin indicated that all-trans retinoic acid (atRA) upregulated Wnt10b gene expression, although synergistic upregulation (combined atRA and VD3) was not seen. RNA interference with vitamin D receptor (VDR) revealed that VD3 upregulation of Wnt10b, ALPL, and TGF-?2 was mediated through the genomic VDR pathway. In a rat model of de novo hair regeneration by murine DPC transplantation, pretreatment with VD3 significantly enhanced hair folliculogenesis. Specifically, a greater number of outgrowing hair shafts and higher maturation of regenerated follicles were observed. Together, these data suggest that VD3 may promote functional differentiation of DPCs and be useful in preserving the hair follicle-inductive capacity of cultured DPCs for hair regeneration therapies.
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