Center for Reproductive Medicine, Cheeloo College of Medicine, Shandong University, China; National Research Center for Assisted Reproductive Technology and Reproductive Genetics, Shandong University, Jinan, Shandong 250012, China; Key Laboratory of Reproductive Endocrinology of Ministry of Education, Jinan, Shandong 250001, China; Shandong Provincial Clinical Research Center for Reproductive Health, Jinan, Shandong 250012, China.
Advanced Medical Research Institute, Shandong University, Jinan, Shandong 250012, China.
Ecotoxicol Environ Saf. 2022 Sep 1;242:113921. doi: 10.1016/j.ecoenv.2022.113921. Epub 2022 Jul 28.
Oocyte quality is essential for a successful pregnancy. 1-Nitropyrene (1-NP) is a widely distributed pollutant in the environment and is well-known for its mutagenicity and carcinogenicity. However, whether 1-NP has toxic effects on mammalian oocyte quality remains unknown. In the present study, we focused on the effect of 1-NP on oocyte maturation using mouse oocytes as an in vitro model. Our study showed that 1-NP exposure disrupted the meiotic spindle assembly and caused chromosome misalignment, further impaired first polar body extrusion, and significantly decreased the fertilization capability in mouse oocytes. Further investigation showed that the mitochondrial membrane potential (MMP) and ATP levels were decreased, and the expression of genes encoding components of the mitochondrial respiratory chain was inhibited in 1-NP exposed oocytes. Meanwhile, 1-NP exposure increased the levels of reactive oxygen species (ROS), inhibited the expression of genes encoding antioxidant enzymes, and increased the frequency of early apoptotic oocytes. Overall, our data suggest that 1-NP exposure disrupts mitochondrial function and intracellular redox balance, ultimately impairing oocyte maturation. These findings reveal the adverse effect of 1-NP exposure on oocyte quality.
卵母细胞质量对于成功妊娠至关重要。1-硝基芘（1-NP）是环境中广泛分布的污染物，其具有致突变性和致癌性。然而，1-NP 是否对哺乳动物卵母细胞质量具有毒性作用尚不清楚。在本研究中，我们使用小鼠卵母细胞作为体外模型，专注于 1-NP 对卵母细胞成熟的影响。我们的研究表明，1-NP 暴露会破坏减数分裂纺锤体的组装，导致染色体排列不齐，进一步损害第一极体的排出，并显著降低小鼠卵母细胞的受精能力。进一步的研究表明，暴露于 1-NP 的卵母细胞中线粒体膜电位（MMP）和 ATP 水平降低，编码线粒体呼吸链组成部分的基因表达受到抑制。同时，1-NP 暴露会增加活性氧（ROS）的水平，抑制抗氧化酶基因的表达，并增加早期凋亡卵母细胞的频率。总体而言，我们的数据表明，1-NP 暴露会破坏线粒体功能和细胞内氧化还原平衡，最终损害卵母细胞成熟。这些发现揭示了 1-NP 暴露对卵母细胞质量的不良影响。
