Haichao Wang, Qing Cheng, Xiaoyan Li, Feifei Hu, Longsen Han, Hao Zhang, Ling Li, Juan Ge, Xiaoyan Ying, Xuejiang Guo, Qiang Wang

Maternal obesity has been reported to impair oocyte quality in mice, however, the underlying mechanisms remain unclear. In the present study, by conducting a comparative proteomic analysis, we identified a reduced expression of TIGAR protein in ovulated oocytes from high-fat diet (HFD)-fed mice. Specific depletion of TIGAR in mouse oocytes results in the marked elevation of reactive oxygen species (ROS) levels and the failure of meiotic apparatus assembly. Importantly, forced expression of TIGAR in HFD oocytes not only attenuates ROS production, but also partly prevents spindle disorganization and chromosome misalignment during meiosis. Meantime, we noted that TIGAR knockdown in oocytes induces a strong activation of autophagy, while overexpression of TIGAR significantly reduces the LC3 accumulation in HFD oocytes. By anti-oxidant treatment, we further demonstrated that such an autophagic response is dependent on the TIGAR-controlled ROS production. In summary, our data indicate a role for TIGAR in modulating redox homeostasis during oocyte maturation, and uncover that loss of TIGAR is a critical pathway mediating the effects of maternal obesity on oocyte quality.