Copper oxide nanoparticles impairs oocyte meiosis maturation by inducing mitochondrial dysfunction and oxidative stress

Copper oxides nanoparticles (CuO NPs) are widely used for a variety of industrial and life science applications. In addition to cause neurotoxicity, hepatotoxicity, immunotoxicity, CuO NPs have also been reported to adversely affect the reproductive system in animals; However, little is known about the effects and potential mechanism of CuO NPs exposure on oocyte quality, especially oocyte maturation. In the present study, we reported that CuO NPs exposure impairs the oocyte maturation by disrupting meiotic spindle assembly and chromosome alignment, as well as kinetochore-microtubule attachment. In addition, CuO NPs exposure also affects the acetylation level of alpha-tubulin in mice oocyte, which hence impairs microtubule dynamics and organization. Besides, CuO NPs exposure would result in the mis-localization of Juno and Ovastacin, which might be one of the critical factors leading to the failure of oocyte maturation. Finally, CuO NPs exposure impairs the mitochondrial distribution and induced high levels of ROS, which led to the accumulation of DNA damage and occurrence of apoptosis. In summary, our results indicated that CuO NPs exposure had potential toxic effects on female fertility and led to the poor oocyte quality in female mice.