Experimental & Molecular Medicine Original Figures

Copper oxide nanoparticles (CuO NPs) are widely used as catalyst or semiconductor in material fields. Recent studies suggested that CuO NPs have adverse genotoxicity and cytotoxicity effect on various cells. However, little is known about the toxicity of CuO NPs following exposure to murine lungs. The purpose of this fundamental research was to investigate whether CuO NPs could induce epithelial cell injury, pulmonary inflammation, and eventually fibrosis in C57BL/6 mice. Our studies showed that CuO NPs could obviously aggravate the pulmonary inflammation in a dose dependent manner. CuO NPs were also able to induce apoptosis of epithelial cells indicated by TUNEL staining, flow cytometry and western blot analysis, which was partially caused by increased reactive oxygen species (ROS). In addition, CuO NPs explosoure could promote the collagen accumulation and expression of progressive fibrosis marker α-SMA in lung tissues, indicating that CuO NPs inhalation could induce pulmonary fibrosis in C57BL/6 mice. All data provide a novel evidence that there is an urgent need to prevent the adverse effects of CuO NPs to human respiratory system.