Spending too much time in the sun without protection can leave our skin red and painful—just like a lobster. We’ve always heard that sunburn happens because the sun damages our skin’s DNA. But a recent study suggests we might need to reevaluate that idea.
A team of researchers from the University of Copenhagen found that while sunburn does cause DNA damage, it’s actually the RNA that gets hurt first, sparking an immediate response in our bodies. Anna Constance Vind, the lead molecular biologist in the study, explains that the common belief was that DNA damage led to the painful effects of sunburn. However, their research shows it’s the RNA that triggers the skin’s reaction.
The term “sunburn” can be misleading. Unlike regular burns from heat, sunburn is caused by exposure to UVB rays. These rays can lead to various stress responses in our cells. When our skin cells experience damage, they signal the immune system, which reacts by increasing blood flow and making us more sensitive to pain.
Identifying the precise triggers of sunburn can be complex. Even factors like heat or the presence of reactive substances can alert the immune system. Traditionally, it was assumed that UVB light primarily affects DNA. However, this new research shows that RNA damage actually plays a more significant role initially.
Vind and her team tested their theory using mice specially bred to lack a key stress response protein called ZAK-alpha. This protein typically helps the cell respond when messenger RNA translation goes awry. When exposed to UV rays, the mice without ZAK-alpha didn’t exhibit the expected sunburn symptoms, indicating that RNA damage is crucial for the sunburn response.
Further experiments with human skin cells confirmed that when RNA is damaged by UV rays, the cells respond by shutting down and alerting the immune system. This suggests that monitoring RNA damage could help improve our understanding of how our skin reacts to sunlight and potentially lead to better treatments for sunburn and other skin conditions exacerbated by the sun.
The findings from this study represent a significant shift in our understanding of skin responses to UV radiation. By focusing on RNA damage, scientists may uncover new ways to address sunburn effectively.
This research was detailed in the journal Molecular Cell.
