Laser photobiomodulation influences the expression of genes related to the inflammatory process and muscle cell differentiation during the process of muscle healing

Abstract

AbstractThe aim of this study was to evaluate the effects of 780-nm laser therapy on the expression of genes related to muscle healing.Sixty-three rats were distributed into three groups: 1) injured control group (CG), 2) injured treatment group at 10 J/cmAt day 7, G10 presented a smaller necrosis area compared to CG and G50. Fourteen days post-surgery, G10 and G50 presented a smaller amount of inflammatory cells and a better tissue organization compared to CG. On day 21, G10 and G50 showed better muscle structure than the control. A significantly decreased COX-2 expression was observed in groups G10 and G50 at day 7 compared to the control animals. No difference was found among the experimental groups after 14 days, but G50 presented statistically higher COX-2 down-regulation at day 21. VEGF expression decreased in the first period analyzed in both treatment groups, increased after 14 days in G10, and increased after 21 days in G50. Both irradiated groups had a higher MyoD expression in all the evaluated periods and myogenin levels increased after 14 days in both treatment groups and in G10 after 21 days.780-nm laser therapy had positive effects during muscle regeneration through the gene expression modulation related to the inflammatory process and the new muscle fibers formation, in both fluencies used in the present study, but the fluence of 10 J/cm