Changes in the mitochondrial function of fibroblast-like cells exposed to copper oxide nanoparticles

Abstract

Introduction. Mitochondria are targets for almost all types of damaging agents, including toxins and oxidative stress. There is no doubt that possible effects on mitochondria should be taken into account in a comprehensive assessment of metal toxicity. Our objective was to establish changes in the mitochondrial function under the effect of copper oxide nanoparticles in vitro. Material and methods. A monolayer culture of human lung fibroblast-like cells of the FLECH-104 line were exposed to copper oxide nanoparticles (CuO NPs) 21±4 nm in size, final concentrations of which in the media were 25, 50, and 100 μg/mL. We measured the rate of oxygen consumption by the cells and its changes under the influence of modulators, such as oligomycin, carbonyl cyanide 4-(trifluoromethoxy)phenylhydrazone, and rotenone combined with antimycin A. We estimated parameters of mitochondrial function and the bioenergetics index. Results. At the concentration of 100 μg/mL in the incubation medium, CuO NPs induced changes in the culture of fibroblast-like cells that impeded further assessment of the mitochondrial function. At the lower concentrations of 25 and 50 μg/mL, we observed a dose-dependent trend toward a decrease in ATP-related respiration and bioenergetics index. It is noteworthy that the concentration of 25 μg/mL increased the maximum and reserve respiratory capacity of the cells, which was probably related to the dual effect of copper as a toxicant and an essential element. Limitations of the study. The study was conducted using only one cell line and three concentrations of CuO nanoparticles suspended in the culture medium. Conclusion. We established that copper oxide nanoparticles, when added to the incubation medium, have a multidirectional effect on the mitochondrial function of fibroblast-like cells potentially attributed to biotic properties of this metal.