Scientists May Have Discovered “Hair Loss Gene” and Hair Growth Stem Cell
October 14, 2008 by Julian Phillips
Filed under Aderans Research Institute, Dermal Papilla (DP) Cells, Follica, GlaxoSmithKline, Hair Follicle Stem Cells, Hair Growth, Hair Loss, Hair Regrowth, Hair Rejuvenation, Intercytex, Karolinska Institute, Lgr5 Protein, Stem Cell Treatments
Bloomberg News reports on two new studies that may have discovered the genes that put people at risk for hair loss and a stem cell that may actually grow hair.
The two studies — one on the genetic basis for hair loss, the other on hair follicle stem cells — were published recently in the journal Nature Genetics. Scientists from London-based GlaxoSmithKline Plc, the U.K. and Sweden worked together on the research.
“Early prediction before hair loss starts may lead to some interesting therapies that are more effective than treating late-stage hair loss,” said Tim Spector, a led researcher on the gene study who works at Kings College London’s department of twin research and genetic epidemiology, in a statement.
Spector and his colleagues analyzed the genes of 578 men in Switzerland with early-onset hair-loss, and compared them against those of 547 others who were retaining their hair. They then confirmed their findings against groups from the U.K., Iceland and the Netherlands, studying about 5,000 people in all. Those with hair loss commonly shared the same variations of two genes that together made them seven times more likely to suffer baldness, researchers from Kings College London and GlaxoSmithKline Plc wrote in the journal Nature Genetics.
The research associates the genes with hair loss, though further studies are needed to prove the connection. The genetic variations were also found in women, though the link wasn’t statistically significant and more research is needed, the authors said. The study was partly funded by Glaxo.
In the stem cell study, researchers led by Viljar Jaks of Sweden’s Karolinska Institute examined mouse hair follicles for signs of rapid growth. They found a protein, called Lgr5, on the surface of long-lived, active stem cells in hair cells; the same protein has been identified on stem cells in the intestine, they said in the study.
Cells bearing the Lgr5 marker were capable of maintaining hair follicles for as long as 14 months, the researchers said. In mouse studies, just a few of these cells were able to build an entire hair follicle, they said in the study.
The Swedish scientists identifying the Hair Follicle Stem Cells summarized their research in this way:
In mouse hair follicles, a group of quiescent cells in the bulge is believed to have stem cell activity. Lgr5, a marker of intestinal stem cells, is expressed in actively cycling cells in the bulge and secondary germ of telogen hair follicles and in the lower outer root sheath of anagen hair follicles. Here we show that Lgr5+ cells comprise an actively proliferating and multipotent stem cell population able to give rise to new hair follicles and maintain all cell lineages of the hair follicle over long periods of time. Lgr5+ progeny repopulate other stem cell compartments in the hair follicle, supporting the existence of a stem or progenitor cell hierarchy. By marking Lgr5+ cells during trafficking through the lower outer root sheath, we show that these cells retain stem cell properties and contribute to hair follicle growth during the next anagen. Expression analysis suggests involvement of autocrine Hedgehog signaling in maintaining the Lgr5+ stem cell population.
