Source: Salk Institute
Salk scientists have uncovered an unexpected molecular target of a common treatment for alopecia, a condition in which a person’s immune system attacks their own hair follicles, causing hair loss.
The findings, published in Nature Immunology on June 23, 2022, describe how immune cells called regulatory T cells interact with skin cells using a hormone as a messenger to generate new hair follicles and hair growth.
“For the longest time, regulatory T cells have been studied for how they decrease excessive immune reactions in autoimmune diseases,” says corresponding author Ye Zheng, associate professor in Salk’s NOMIS Center for Immunobiology and Microbial Pathogenesis.
“Now we’ve identified the upstream hormonal signal and downstream growth factor that actually promote hair growth and regeneration completely separate from suppressing immune response.”
The scientists didn’t begin by studying hair loss. They were interested in researching the roles of regulatory T cells and glucocorticoid hormones in autoimmune diseases. (Glucocorticoid hormones are cholesterol-derived steroid hormones produced by the adrenal gland and other tissues.) They first investigated how these immune components functioned in multiple sclerosis, Crohn’s disease and asthma.
They found that glucocorticoids and regulatory T cells did not function together to play a significant role in any of these conditions. So, they thought they’d have more luck looking at environments where regulatory T cells expressed particularly high levels of glucocorticoid receptors (which respond to glucocorticoid hormones), such as in skin tissue.
The scientists induced hair loss in normal mice and mice lacking glucocorticoid receptors in their regulatory T cells.
“After two weeks, we saw a noticeable difference between the mice—the normal mice grew back their hair, but the mice without glucocorticoid receptors barely could,” says first author Zhi Liu, a postdoctoral fellow in the Zheng lab. READ MORE...
The findings, published in Nature Immunology on June 23, 2022, describe how immune cells called regulatory T cells interact with skin cells using a hormone as a messenger to generate new hair follicles and hair growth.
“For the longest time, regulatory T cells have been studied for how they decrease excessive immune reactions in autoimmune diseases,” says corresponding author Ye Zheng, associate professor in Salk’s NOMIS Center for Immunobiology and Microbial Pathogenesis.
“Now we’ve identified the upstream hormonal signal and downstream growth factor that actually promote hair growth and regeneration completely separate from suppressing immune response.”
The scientists didn’t begin by studying hair loss. They were interested in researching the roles of regulatory T cells and glucocorticoid hormones in autoimmune diseases. (Glucocorticoid hormones are cholesterol-derived steroid hormones produced by the adrenal gland and other tissues.) They first investigated how these immune components functioned in multiple sclerosis, Crohn’s disease and asthma.
They found that glucocorticoids and regulatory T cells did not function together to play a significant role in any of these conditions. So, they thought they’d have more luck looking at environments where regulatory T cells expressed particularly high levels of glucocorticoid receptors (which respond to glucocorticoid hormones), such as in skin tissue.
The scientists induced hair loss in normal mice and mice lacking glucocorticoid receptors in their regulatory T cells.
“After two weeks, we saw a noticeable difference between the mice—the normal mice grew back their hair, but the mice without glucocorticoid receptors barely could,” says first author Zhi Liu, a postdoctoral fellow in the Zheng lab. READ MORE...
