Dermal-Epidermal Interactions--Follicle Derived Cell Populations in the Study of Hair-Growth Mechanisms.

The study highlighted the critical role of dermal-epidermal interactions in hair follicle activities, particularly focusing on the inductive properties of dermal papillae cells. It was found that while cultured papilla cells could support epidermal cell proliferation, they did not induce complex differentiation. However, germinative epidermal cells from the follicle base could interact with papilla cells to form complex structures, demonstrating their significant influence on dermal cells. In vivo experiments showed that germinative cells could initiate follicle formation and hair growth when combined with non-inductive dermal sheath cells. Additionally, in vitro experiments revealed that various follicle cell populations could produce hair-type fibers in a three-dimensional culture system. The study also demonstrated that implanting cultured dermal papilla cells into footpad skin could induce new follicle and fiber formation, highlighting the potent and universal inductive capabilities of papilla cells and their potential for dermatologic applications.