miR-10a Expression Is Altered by Folic Acid during H2O2-Exposure-Induced Oxidative Stress in Mouse Oocytes

H2O2 exposure causes oxidative stress, which plays a role in oocyte aging. Folic acid (FA), which is regarded as an antioxidant, can effectively scavenge oxidising free radicals. MicroRNAs (miRNAs) play an important role in regulating gene expression during oocyte development and maturation and may be involved in the H2O2-exposure-induced oxidative stress in oocytes. In the present study, we explored if FA protects oocytes from reactive oxygen species (ROS) in vitro and the role of microRNAs (miRNAs) in this process. We compared the oocyte quality, ROS levels, mitochondrial membrane potential (MMP), 2 pronucleus (2PN) ratios, embryonic developmental potential, and miRNA expression in fresh mouse oocytes, H2O2-treated mouse oocytes, and FA and H2O2-treated mouse oocytes. The results demonstrated that FA could significantly reduce the ROS levels and fragments of H2O2-treated mouse oocytes and increase superoxide dismutase (SOD) levels, alleviating the H2O2-mediated oocyte 2PN ratio decreasing. H2O2-treated oocytes showed increased miR-10a expression, whereas FA treatment decreased miR-10a expression. In conclusion, miR-10a plays a vital role in the prevention of oxidative stress in oocytes.