New Hope Surfaces for Hair Regrowth

From Staff Reports

It kind of makes sense that our immune systems might play a major role in hair growth. And now, scientists at the Salk Institute for Biological Studies in La Jolla, California, have proven the connection in a series of studies.

Ye Zheng, a corresponding study author and associate professor in Salk's NOMIS Center for Immunobiology and Microbial Pathogenesis, said in a recent article published on labroots.com that hair growth can be realized without having to suppress one's immune system. "For the longest time, regulatory T cells have been studied for how they decrease excessive immune reactions in autoimmune diseases," Zheng told Labroots author Carmen Leitch. "Now we've identified the upstream hormonal signal and downstream growth factor that actually promote hair growth and regeneration completely separate from suppressing the immune response."

The Salk Institute is an independent, nonprofit organization dedicated to basic research in the biological sciences and is considered one of the foremost institutions of its kind in the world.

Ye Zheng

Leitch wrote that the research started with a study of how “glucocorticoids and regulatory T cells were related to autoimmune disorders. Glucocorticoids are steroid hormones that can help control inflammation; they are used as a treatment for autoimmune diseases in some cases.”

“The scientists determined that the relationship between glucocorticoids and regulatory T cells don't appear to be involved in several disorders, including asthma, multiple sclerosis, and Crohn's disease,” she wrote.

The scientists then turn their attention to “places where regulatory T cells can be found carrying high levels of glucocorticoid receptors, like the skin. In both normal mice and a mouse model that lacked glucocorticoid receptors, hair loss was induced.”

Leitch reported that researchers found that normal mice could easily regrow their hair after two weeks. Study author Ahi Liu said the mice without glucocorticoid receptors could barely regrow any hair. "It was very striking, and it showed us the right direction for moving forward,” Liu said.

The scientists said that by observing signaling between cells, researchers found that ”glucocorticoids can trigger regulatory T cells to stimulate hair follicle stem cells, leading to hair growth. The connection between T cells and hair follicle stem cells depends on the production of a molecule called TGF-beta3 in regulatory T cells, caused by glucocorticoid receptors. Hair follicle stem cells will differentiate into new hair follicles, and promote hair growth because they've been activated by TGF-beta3.”

A 3D rendering of transforming growth factor (TGF) beta-3, a protein, known as a cytokine, which is involved in cell differentiation, embryogenesis and development.