A new study challenges the common belief that sunburn damages DNA to cause cell death and inflammation. Researchers discovered instead that UV radiation primarily affects RNA, not DNA, leading to skin damage. The study, conducted on mice and human cells, found that mice exposed to UV experienced similar responses as humans.
RNA is a shorter-lived molecule compared to DNA. When UV damage occurs, mRNA (a type of RNA) is affected. This triggers the ribotoxic stress response, orchestrated by ZAK-alpha protein. This system detects RNA damage, triggers inflammatory signals, and recruits immune cells, leading to skin inflammation.
Dr. Simon Bekker-Jensen explained that cells first respond to UV-induced RNA damage, which causes cell death. Without the ZAK gene, mice exposed to UV showed no such responses, indicating its critical role in the skin’s defense mechanism.
The study highlights ZAK-alpha and ribosomes as key stress-signal sensors in the skin’s acute response to UVB irradiation. It also suggests that this response involves distinct roles for RNA damage signaling compared to DNA damage signaling, which has implications for skin immunity and cancer development.
Published on January 18, 2025, at 10:20 pm IST.
Source: https://www.thehindu.com/sci-tech/rna-not-dna-is-the-main-cause-of-acute-sunburn/article69109404.ece