The Effect of Blue Light on Mitochondria in Human Dermal Fibroblasts and the Potential Aging Implications

The deleterious effects of blue light on the skin are becoming an increasing area of research focus, as we are exposed to increasing amounts of blue light in our daily lives. However, the effects of blue light on mitochondrial DNA (mtDNA) damage, mitochondrial function, and production of reactive oxygen species (ROS) have yet to be investigated. Our study involved exposing neonatal human dermal fibroblasts (HDFn) to varying doses of blue light and analyzing mtDNA damage using qPCR, mitochondrial function using a Seahorse XF bioanalyzer, and ROS production using a ROS-Glo assay. Blue light induces increased mtDNA damage dose dependently, with 50 J/cm² of blue light being the minimum dose required to induce significant increased mtDNA strand breaks (p = 0.0001). Mitochondrial oxygen consumption rate (OCR) and reduced adenosine triphosphate (ATP) production also occur simultaneously. The increased mtDNA damage and subsequent dysfunction were complemented by dose dependent increased ROS production. Within these results, 50 J/cm² was consistently the minimum dose required to induce significant increased ROS production (p = 0.0475), reduced mitochondrial OCR, and virtually absent ATP production (p = < 0.0001). These findings suggest that blue light may have similar effects on mitochondria that have already been reported in skin exposed to ultraviolet radiation (UVR).