P4.45 HAIR INDUCTION BY AUTOLOGOUS TRANSPLANTATION OF HUMAN DERMAL PAPILLA CELLS ONTO FOREHEAD SCALP

^{1, 3}Koh-ei Toyoshima*, ²Akio Sato, ^{1, 3}Mikaru Yamao, ^1,3Mutsumi Inamatsu, ^{1, 3}Takashi Shimada, and ^{5, 4}Katsutoshi Yoshizato

¹PhoenixBio Co. Ltd. Hiroshima, Japan, ²Tokyo Memorial Clinic Hirayama, Tokyo Japan, ³Innovation Plaza Hiroshima, JST, Hiroshima, Japan, ⁴Dept. of Biological Science, Graduate School of Science, Hiroshima University, Hiroshima, Japan.

Objectives: Previously, we propagated human dermal papilla cells (DP cells) in culture. Culture-propagated human DP cells were mixed with newborn rat epidermal cells and transplanted onto the back of nude mice to examine their hair inducing ability. The result clearly showed that they induce epidermal cells to differentiate into hair follicles and shafts. The resulting hair shafts developed well and came out from the surface of the epidermis. In the present study we transplanted culture-propagated human DP cells onto human scalp skin to examine their hair-inducing ability there.

Methods: DP cells were isolated from pieces of occipital scalp skin removed from two normal volunteers, 44- (case 1 and 3) and 32-year-old–males (case 2), with informed consents. Fresh DP cells (case 1 and 2) or serially subcultured DP cells (case 3) were labeled with fluorescent die (DiI), mixed with fresh autologous epidermal cells, and autologously transplanted into trepanated halls of forehead skin. These transplanted sites were covered with silicone caps in the first 3 days after transplantation. Transplanted cites were macroscopically observed for hair-growth every 7 days during 3-4 weeks postoperatively. At the end of this examination, transplanted area was biopsied and processed for histology.

Results: In case 1, two white and thin hair shafts (2 and 3 mm-long) were visibly erupted from the surface of scalp. Their hair bulbs contained DiI-labeled DPs. In case 2, a 0.6 mm-thin hair shaft was erupted from the surface of scalp. In case 3, two white (0.3 and 0.5 mm-long) and thin hair shafts were erupted with DiI-labeled DPs.

Conclusions: We concluded that DP cells could be propagated in culture without losing their inherent hair-inducing ability. These culture-propagated human DP cells will be a useful source for hair regeneration therapy on bald people.