The Dawn of Hair Cloning

The eureka moment for Colin Jahoda, M.D., Ph.D., and Amanda Reynolds, Ph.D.—a husband-and-wife team of biologists at the University of Durham, in England—involved an experiment that also served as a nerdy version of a "Colin Forever" tattoo. Dr. Jahoda removed a hair follicle from his head, put it under a microscope, and snipped off a cluster of dermal papilla cells, which are located in a bulb at the root of the shaft. He then nicked his wife's forearm with a scalpel and transplanted the cells. A few days later, a thick tuft of dark hair (complete with Dr. Jahoda's male DNA) emerged

The experiment demonstrated, for the first time, the possibility of growing hair from transplanted dermal papilla cells. It seemed the two had found a new treatment for hair loss. Yet they soon discovered that, once removed from the body, dermal papilla cells quickly lose their ability to make hair if they are not transplanted immediately.

Angela Christiano, Ph.D., a professor of dermatology and genetics and development at the Columbia University College of Physicians and Surgeons, collaborates closely with Dr. Jahoda on hair-related research. "Not long after you remove them, the cells don't even know they're dermal papillae anymore," Christiano says, who is sitting in her office behind a desk piled two feet high with books and papers. "It's like taking an Etch-a-Sketch and shaking it," she says. "You erase their identity."

The Jahoda-Reynolds experiment worked because a clump of hair follicle cells were promptly relocated, which preserved their inductivity, a measure of their capacity to remain uniquely hair cells before devolving into something more generic. While I'm in her office, Christiano calls England and puts Dr. Jahoda on speakerphone. "These cells seem to have an in-built regulatory system," he explains. "We don't know how it works. Getting the cells to remain inductive is still the basic challenge."

Christiano became interested in hair follicle research in 1996, when a common hair disorder called alopecia areata caused patches of her own hair to fall out abruptly (steroid injections have revived it to a formidable whorl of ebony locks). Two years later, she made headlines after announcing she'd pinpointed several specific genes that are responsible for other genetic forms of hair loss—a scientific first.

She is now focused almost exclusively on finding new genes for hair loss, as well as using dermal papilla cells to develop new ways of treating it. Scientists are still unclear about precisely what occurs, but they do know that whenever you pluck or shave a hair, molecular compounds in the follicle begin a complex dialogue with surrounding cells. These include dermal papillae, epithelial cells (those lining the wall of the hair shaft), and stem cells in a little-understood region referred to as "the bulge."

The dermal papillae are encoded with genetic instructions that respond to cues sent from surrounding cells and tissues in the follicle. Once signaled, the dermal papillae begin hatching hair fibers. What Christiano and Dr. Jahoda are trying to figure out is how to trick the cells into growing hair by themselves, without guidance from the rest of the follicle. Doing this would allow scientists to culture, or clone, thousands of dermal papilla cells in the lab that would retain their knack for producing hair.

"With current transplant surgery, if you take a thousand follicles from the back of the head and move them to the front, you still only have a thousand," Christiano says. "With the cloning approach, you could start with a small biopsy of cells and then grow enough of them to repopulate your entire scalp with hair."

A researcher named Claire Higgins informs us she has just received a fresh dime-size chunk of live scalp donated by a male hair-transplant patient. We join her in a lab, where she is hunched over a steel table, staring into a microscope. With forceps and a long needle, she scrapes dermal papillae from each follicle.

I look through the eyepiece. She tells me I'm viewing roughly 3,000 dermal papillae packed into a ball of cells just a fraction of a millimeter wide. They resemble golden tobiko, the flying-fish roe dolloped onto sushi rolls. These cells will end up in an incubator, where they'll be cultured for at least 4 weeks and then transplanted into mice to see if they'll produce hair.

Several factors determine whether this happens. One is the growth medium, the soupy broth fed to the cells to help them thrive. Another is how quickly the cells multiply: As Dr. Jahoda and Reynolds showed, the less time cells spend outside the body, the better they retain their inductivity. A third factor is how the cells are transplanted. Do you inject them? Or position them surgically under the skin?

"We're trying to get into the heads of the dermal papillae and understand why they lose their inductivity," Christiano says. "Then we'll do the reverse: Take old cells that have been in culture for many months and bring them back into the fold, coaxing them to grow hair."

I ask Christiano how she and Dr. Jahoda intend to accomplish this. She smiles, clearly not wanting to tip her hand, and replies, "We have a few ideas. I will say that if we figure it out, a lot of hair-loss sufferers will be very, very happy." Their research could also inform next-generation baldness cures, genetic fixes that reprogram the cells, much like a software patch, and override the genes responsible for androgenetic alopecia.