One Molecule Makes Stem Cells Grow Hair ...

We’ve all found hairs where they shouldn’t be or hoped hair would grow where it doesn’t. Now there’s a molecule to blame. Researchers led by Elaine Fuchs at Rocke­feller University, in New York City, have discovered that a protein called Tbx1 helps hair follicle stem cells remain self-renewing, a characteristic that means the stem cells can continue to spawn the production of new hairs (Nature, DOI: 10.1038/nature10940). This is the first self-renewing factor discovered for adult hair follicle stem cells and one of only a few such factors known for any adult stem cells, Fuchs says. To find Tbx1, her team made use of a library of 2,000 short hairpin RNAs that could silence a selection of genes preferentially expressed by long-lived hair follicle stem cells. When the gene for Tbx1 was silenced in hair follicle stem cells using one of these hairpin RNAs, self-renewal was also silenced. Because Tbx1 operates in the nucleus, any drug to target the protein would have to get inside the cells, Fuchs says. Another option would be to step backward and figure out what naturally regulates Tbx1 expression and then target that pathway, she adds.