The basic cause of hair growth has been identified by scientists in the United States. The research showed that a subtle interaction between two signalling molecules causes hair follicles to sprout.
The findings explain the genetic signals that determine why parts of us are hairy and parts are not. They may also help explain the development of teeth and lungs, as well as some forms of skin cancer.
Elaine Fuchs, from Rockefeller University, New York City, found that hair growth began with an immature skin stem cell receiving two signals from its neighbours. The signalling molecules, called Wnt and noggin, activated elements in the cell’s nucleus which led to a pit forming in the skin and the creation of a hair follicle.
The scientists reported in the journal Nature how they produced an abnormally furry mouse with high numbers of hair follicles. They showed how a complex mixture of interactions ended up with lower levels of the cellular protein E-cadherin, which helps cells stick together.
”Our studies suggest that too much or too little E-cadherin can be a bad thing,” said Fuchs.
”Just the right amount of E-cadherin is needed to loosen the adhesion of the stem cells in the epithelium, to allow them to remodel and grow downward to form the hair follicle.” ‒ Sapa-DPA