A PFAS mixture at environmental relevant concentration induces DNA damage and compromises the in vitro maturation of mouse oocytes

Per- and polyfluoroalkyl substances (PFAS) are persistent environmental pollutants that can accumulate in the human body, including follicular fluid (FF), potentially affecting the function of reproductive cells. We used the mixture of these chemicals at concentrations previously reported in human FF to assess their effects on in vitro maturation, DNA integrity, and mitochondrial function of mouse oocytes. Exposure to PFAS led to meiotic abnormalities, manifested by an increase in the percentage of oocytes arrested at the germinal vesicle breakdown (GVBD) stage and a decrease in the number of oocytes reaching the metaphase II (MII) stage. We demonstrated that arrest at GVBD is associated with Spindle Assembly Checkpoint (SAC) activation as experimental inhibition of SAC restores normal maturation to MII. In addition, we observed increased DNA damage and changes in oxidative balance, including an increase in reduced glutathione (GSH) and a decrease in reactive oxygen species (ROS) levels. However, we found an increase in mitochondrial activity, basal oxygen consumption (OCR), and mitochondrial respiration intensity in immature GV stage oocytes, indicating disturbances in bioenergetic homeostasis. These findings show for the first time that PFAS mixtures, at concentrations relevant to human exposure, interfere with oocyte maturation, genome integrity, and mitochondrial function. The data obtained highlight the need for further research on the toxicity of PFAS mixtures, especially at doses mirroring their environmental presence, and their potential impact on female fertility.