A Hair Loss Study Raises New Questions About Aging Cells

Next, they got patients from a hair transplant clinic to donate follicles, then grafted those healthy hairs onto mice. Follicles normally undergo a sort of shock after a transplant, going dormant for a couple months. Plikus suspected that osteopontin could rouse the grafted follicles faster. Thirty days after grafting, some of these mice received osteopontin injections. Twenty days later, only those mice had sprouted human hair.

So far, the lab’s new paper has been well received—at least when it comes to the conclusions about growing hair. “It’s a really well-done and convincing paper,” says Valerie Horsley, a cell biologist at Yale University who was not involved in the work. Horsley likes that the team also pinpointed the follicle protein (CD44) that receives the signal from osteopontin. Without it, osteopontin has no effect. Tinkering with either could help regrow human hair, she thinks: “That would be cool. And we could inhibit it—stop hair growth in areas where we don’t want hair to grow.”

“It’s very exciting,” says Etienne Wang, a clinician-scientist…