Researchers find cause of pain in sunburn

August 28, 2013

Scientists have found that blocking the molecule TRPV4 can help to prevent the pain caused by sunburns.

 

Scientists have found that blocking the molecule TRPV4 can help to prevent the pain caused by sunburns.

Researchers with Duke University School of Medicine, Durham, N.C., conducted experiments on mouse and human skin samples to identify what triggers pain caused by sunburn. They built a mouse model that was lacking the ion channel TRPV4 only in the cells of the epidermis.

Genetically engineered mice and controls had their hind paws exposed to UVB rays. The skin in normal mice became hypersensitive and blistered, while the genetically altered mice demonstrated little tissue injury and sensitization, according to a news release.

Using cultured mouse skin cells to dissect TRPV4’s activities, researchers found that UVB causes calcium to flow into skin cells, but only when the TRPV4 ion channel is present. The researchers then dug deeper, learning that TRPV4 is activated by UVB, then causing an influx of calcium ions. This process brings in the molecule endothelin, triggering TRPV4 to send even more calcium to cells. The endothelin is responsible for the pain from sunburn.

Scientists then used the pharmaceutical compound GSK205 to inhibit TRPV4 in the hind paws of normal mice. These mice were mostly resistant to the effects of sunburn, study authors determined. They noted that further research into TRPV4 inhibition is necessary.

“I think we should be cautious because we want to see what inhibition of TRPV4 will do to other processes going on in the skin,” Wolfgang Liedtke, M.D., Ph.D., a senior author of the study, said in the news release. “Once these concerns will be addressed, we will need to adapt TRPV4 blockers to make them more suitable for topical application. I imagine it being mixed with traditional sunblock to provide stronger protections against UVB exposure.”

The study findings were published online Aug. 5 in the Proceedings of the National Academy of Sciences

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