A French team headed by Yann Barrandon (INSERM CRI 9602, Ecole Normale Supérieure) has just shown that the skin of adult mammals contains stem cells capable of giving rise to all the cell types necessary to reconstitute the epidermis, sebaceous glands (which produce sebum) and hair follicles (that make hairs).

The skin's stem cells are mainly located in hair follicles. This discovery opens up major new perspectives 1) in dermatology, to favor wound healing and to improve the results of skin grafting in burns patients, 2) in oncology, to understand the origins of some skin cancers, and 3) in cosmetology, to treat both hair loss and excess body hair.

These results are published in the journal Cell today.

As their name suggests, hair follicles -- skin structures characteristic of mammals -- produce hairs. Among other roles, hairs help to regulate body temperature and protect the organism from environmental aggressors such as ultraviolet radiation.

Hair follicles, located deep within the dermis, are in fact annexes of the epidermis. Mice possess about 50 hair follicles per square millimeter of skin, whereas humans only have about 5/mm2. Several research teams, including Yann Barrandon's, had previously obtained results strongly suggesting that hair follicles serve as stem cell sources.

(Reference: Cell, January 26 2001, vol. 104)

26-Jan-2001