Low-power red laser and ultraviolet A LED irradiation alters mRNA levels from DNA repair genes in <i>Saccharomyces cerevisiae</i>

Abstract Therapeutic protocols based on photobiomodulation (PBM) have been used to treat wounds, pain, and inflammation. One of the underlying mechanisms of PBM is the absorption of low-dose, non-ionizing radiation by cytochrome c oxidase, leading to the production of reactive oxygen species. Such species can cause oxidative damage in DNA, which is repaired by base excision repair (BER) and nucleotide excision repair (NER) mechanisms. Up to date, few studies have assessed oxidative damage in DNA as a consequence of low-power red lasers and ultraviolet A LED on expression of DNA gene repair. This study aimed to determine the expression of genes related to BER and NER pathways in S. cerevisiae after irradiation with low-power red laser and ultraviolet A LED. Cultures of S. cerevisiae were exposed to a low-power red laser (660 nm, 21.2 J cm −2 , 205 s, 99 mW) and an ultraviolet A LED (390 nm, 6 J cm −2 , 205 s, 7 mW), incubated for 1 h, total mRNA was extracted, cDNA was synthesized, and OGG1, APN1, RAD1 and RAD10 mRNA levels in S. cerevisiae FF18733 were evaluated by RT-qPCR. The results indicated that exposure to the low-power red laser does not induce changes in gene expression, but exposure to ultraviolet A LED alone and simultaneously with the low-power red laser significantly reduced APN1 and RAD10 mRNA levels in S. cerevisiae . Exposure to the low-power red laser could not affect mRNA from BER and NER, but ultraviolet A LED and simultaneous low-power red laser and ultraviolet A LED could decrease gene expression of BER and NER pathways in S. cerevisiae .