Avaliação dos Efeitos de Lasers de Baixa Potência no Níveis de mRNAs de Genes Desacopladores de Proteínas e de MicroRNAs

Abstract

Low power lasers are used daily by professionals in healthy field. Wavelength, frequency, fluence and mode of emission are determinant to low power lasers photochemistry, photophysical and phobiological responses. However, these lasers may increase the production of free radicals, which could interact with important biomolecules, such as DNA. It has been suggested that free radicals are involved in biological responses acting as second messengers in intracellular signaling processes. Stressed cells present mechanisms of defense against theses chemical species to avoid unwanted effects. Uncoupling Proteins (UCPs) are part of protective mechanism to minimize effects of free radical generation in mitochondria. The relative level of these proteins could be altered in post-transcriptional or post-translational levels. The microRNAs are mediators of post-transcriptional gene relative level. So, this work aimed to evaluate relative levels of UCP2 and UCP3 mRNAs in skin and skeletal muscle in Wistar rats, and evaluate UCP2 mRNA and mir-15a and mir-106b in MDA-MB-231 cells exposed to red and infrared low level lasers in different fluences. Cells’ RNA was withdrawn and cDNA synthesis and miRNA first strand was performed to perform RT-qPCR of UCP2 and UCP3 mRNA and miRNAs. Data in this study suggest that UCP2 and UCP3 mRNA are not equally altered in both skin and skeletal muscle in Wistar rats exposed to low power lasers. This alteration is wavelength and fluence-dependent, suggesting a bioestimulation effect that could make cells more resistant to lasers exposure. However, breast cells exposed to low power lasers, mir-15a and mir-106b that had no alteration, however, relative levels of UCP2 mRNA increased.