Study on mice offers hope for baldness cure

Mice with deep skin wounds can grow new hair, scientists said Wednesday in a finding that offers hope for a baldness remedy for humans.

The mice regenerated hair at the site of the wound via molecular processes similar to those used in embryonic development, according to the research published in the journal Nature.

The findings show that mammals possess greater regenerative abilities than commonly believed. Study leader George Cotsarelis, a dermatology professor at the University of Pennsylvania School of Medicine, said the findings dispelled the dogma that mammal skin could not regenerate hair follicles.

The regenerated follicles functioned normally, cycling through the various stages of hair growth. The hairs lacked pigmentation but were otherwise indistinguishable from neighboring hairs.

The researchers made relatively large wounds on the backs of adult mice, and found that if a wound reached a certain size, new hairs formed at its center, with the skin undergoing changes that mimicked stages of embryonic hair-follicle development.

Dormant embryonic molecular pathways were activated, sending stem cells -- which are able to transform into other cell types -- to the damaged skin.

“They’re actually coming from epidermal cells that don’t normally make hair follicles. So they’re somehow reprogrammed and told to make a follicle,” Cotsarelis said.

The researchers also found a way to amplify the natural regeneration process, causing mice to grow twice as many new hairs by giving the skin a specific molecular signal.