Health & Medicine

Painful Red Skin from Sunburns May in the Past: Scientists Discover Molecule Responsible

Catherine Griffin
First Posted: Aug 06, 2013 09:35 AM EDT

Painful, red skin from sunburns may be a thing of the past. Scientists have discovered the molecule responsible for the uncomfortable feeling after a burn, which could lead to better treatments to help prevent the tender aftereffects of a day in the sun.

Most sunburns are caused by ultraviolet B or UVB radiation. In moderation, this component actually helps the body by giving it a dose of vitamin D; other studies have suggested that sunlight can even improve mood. Yet there can be too much of a good thing. This sunlight can also damage DNA in skin cells and increase a person's susceptibility to cancer.

Yet why do we feel pain after these sunburns occur? That's what scientists wanted to find out. A molecule called TRPV4 is found in high concentrations in the epidermis, which led researchers to believe it was possible that it played a role in the pain and tissue damaged caused by sunburns. TRPV4 is an ion channel, which is a gateway in the cell membrane that rapidly lets in positively charged ions such as calcium and sodium.

In order to examine TRPV4 a bit more closely, the researchers built a mouse model that was missing this molecule in the cells of the epidermis. They then exposed the modified mice and normal mice to UVB rays. While the normal mice showed hypersensitive and blistered skin, though, the modified mice showed little tissue injury.

Obviously, this molecule played a role in the sunburn aftereffects. The scientists then cultured mouse skin cells to dissect the activities of TRPV4. They found that UVB caused calcium to flow into the skin cells, but only when the TRPV4 channel was present. They then investigated whether they could block this pain pathway. Using a compound called GSK205 that can inhibit TRPV4, the scientists found that, in fact, mice treated with it were largely resistant to sunburns.

"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, though more work must be done before TRPV4 inhibitors can become part of the sun defense arsenal, perhaps in new kinds of skin cream, or to treat chronic sun damage," said Martin Steinhoff, co-author of the new study, in a news release.

The findings could allow researchers to develop better treatments for sunburns. In addition, it could allow them to better understand how to prevent skin cancer in patients.

The findings are published in the journal Proceedings of the National Academy of Sciences.

See Now: NASA's Juno Spacecraft's Rendezvous With Jupiter's Mammoth Cyclone

More on SCIENCEwr