Scientists discover key to sunburn pain

Scientists have identified a molecule that causes the pain we feel after receiving a sunburn. By identifying and inhibiting the molecule, researchers also may have found a way to block the pain.

A team of researchers at Duke University School of Medicine discovered the molecule TRPV4, which is found in the skin’s outer layer. The TRPV4 molecule is a “gateway” molecule that allows calcium and sodium ions into the skin. The team of researchers, led by Dr. Wolfgang Liedtke, MD, PhD, conducted tests involving the TRPV4 molecule on both mouse models and human skin samples.

"We have uncovered a novel explanation for why sunburn hurts,” said Dr. Liedtke. “If we understand sunburn better, we can understand pain better because what plagues my patients day in and day out is what temporarily affects otherwise healthy people who suffer from sunburn."

In the study, scientists engineered mice with an epidermis (upper skin layer) that was missing the TRPV4 molecule. Both the engineered mice and a control group of normal were exposed to UVB rays. While the normal skin blistered and became hypersensitive when exposed to the UVB rays, the skin without TRPV4 displayed very little tissue injury or sensitivity.

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Dr. Liedtke and his team analyzed the activities of the TRPV4 molecule and found that when exposed to UVB rays, the molecule causes calcium to flood into the skin cells. The calcium ions bring in another molecule, called endothelin, which causes pain and itching in humans. 

The team then used human skin samples to test this phenomenon and found that TRPV4 reacts the same way in humans.

Researchers went a step further to inhibit the TRPV4 molecule. To try to block the pain caused by long-term sun exposure, the researchers used a compound called GSK205, which specifically inhibits TRPV4 and prevents the inpouring of calcium. Control mice injected with this compound were also resistant to the painful effects of the sunburn. 

"The results position TRPV4 as a new target for preventing and treating sunburn, and probably chronic sun damage including skin cancer or skin photo-aging," said Dr. Martin Steinhoff, co-author of the study from the University of California, San Francisco.

More research is needed to understand how the TRPV4 molecule and inhibitors can help reduce sun damage. 

People who have had at least one severe, blistering sunburn are at an increased risk of skin cancer, according to the National Cancer Institute. All people, young and old, should visit a dermatologist several times a year to check for skin cancer. To schedule an appointment with Greenville Dermatology, call us today at (864) 242-5872.