Embryonic dermal condensation and adult dermal papilla induce hair follicles in adult glabrous epidermis through different mechanisms

Inamatsu Mutsumi

Tochio Takumi

Makabe Aya

Endo Tetsuya

Oomizu Souichi

Kobayashi Eiji

Yoshizato Katsutoshi

Development, Growth and Differentiation

Hair induction in the adult glabrous epidermis by the embryonic dermis was compared with that by the adult dermis. Recombinant skin, composed of the adult sole epidermis and the embryonic dermis containing dermal condensations (DC), was transplanted onto the back of nude mice. The epidermis of transplants formed hairs. Histology on the induction process demonstrated the formation of placode-like tissues, indicating that the transplant produces hair follicles through a mechanism similar to that underlying hair follicle development in the embryonic skin. An isolated adult rat sole skin piece, inserted with either an aggregate of cultured dermal papilla (DP) cells or an intact DP between its epidermis and dermis, was similarly transplanted. The transplant produced hair follicles. Histology showed that the epidermis in both cases surrounded the aggregates of DP cells. The epidermis never formed placode-like tissues. Thus, it was concluded that the adult epidermal cells recapitulate the embryonic process of hair follicle development when exposed to DC, whereas they get directly into the anagen of the hair cycle when exposed to DP. The expression pattern of Edar and Shh genes, and P-cadherin protein during the hair follicle development in the two types of transplants supported the above conclusion.

placode

embryonic hairs

hair germs

EGFP-transgenic rats

hair cycle

hair follicles

recombinant skin

skin transplantation

nude mice

Biology [ 460 ]

eng

Blackwell Publishing

Copyright (c) 2006 Blackwell Publishing, Inc

[ISSN] 0012-1592

[NCID] AA00627804

[PMID] 16512852

[DOI] 10.1111/j.1440-169X.2006.00848.x

[DOI] http://dx.doi.org/10.1111/j.1440-169X.2006.00848.x isVersionOf