Department of Animal Science, Chungbuk National University, Cheongju, Chungbuk, Republic of Korea.
Joint Laboratory of the Modern Agricultural Technology International Cooperation, Ministry of Education, Jilin Agricultural University, Jilin, Changchun, 130118, China.
PLoS One. 2022 Nov 28;17(11):e0277477. doi: 10.1371/journal.pone.0277477. eCollection 2022.
Rotenone is a commonly used insecticidal chemical in agriculture and it is an inhibitor of mitochondrial complex Ⅰ. Previous studies have found that rotenone induces the production of reactive oxygen species (ROS) by inhibiting electron transport in the mitochondria of somatic and germ cells. However, there is little precise information on the effects of rotenone exposure in porcine oocytes during in vitro maturation, and the mechanisms underlying these effects have not been determined. The Cumulus-oocyte complexes were supplemented with different concentrations of rotenone to elucidate the effects of rotenone exposure on the meiotic maturation of porcine oocytes during in vitro maturation for about 48 hours. First, we found that the maturation rate and expansion of cumulus cells were significantly reduced in the 3 and 5 μM rotenone-treated groups. Subsequently, the concentration of rotenone was determined to be 3 μM. Also, immunofluorescence, western blotting, and image quantification analyses were performed to test the rotenone exposure on the meiotic maturation, total and mitochondrial ROS, mitochondrial function and biogenesis, mitophagy and apoptosis in porcine oocytes. Further experiments showed that rotenone treatment induced mitochondrial dysfunction and failure of mitochondrial biogenesis by repressing the level of SIRT1 during in vitro maturation of porcine oocytes. In addition, rotenone treatment reduced the ratio of active mitochondria to total mitochondria, increased ROS production, and decreased ATP production. The levels of LC3 and active-caspase 3 were significantly increased by rotenone treatment, indicating that mitochondrial dysfunction induced by rotenone increased mitophagy but eventually led to apoptosis. Collectively, these results suggest that rotenone interferes with porcine oocyte maturation by inhibiting mitochondrial function.
鱼藤酮是农业中常用的杀虫剂化学物质，它是线粒体复合物 Ⅰ的抑制剂。先前的研究发现，鱼藤酮通过抑制体细胞和生殖细胞中线粒体的电子传递来诱导活性氧（ROS）的产生。然而，关于鱼藤酮在猪卵母细胞体外成熟过程中的暴露对卵母细胞的影响，以及这些影响的机制，还没有确切的信息。将卵丘-卵母细胞复合物添加到不同浓度的鱼藤酮中，以阐明鱼藤酮暴露对猪卵母细胞体外成熟约 48 小时时减数分裂成熟的影响。首先，我们发现 3 和 5 μM 鱼藤酮处理组的卵母细胞成熟率和卵丘细胞扩展明显降低。随后，确定鱼藤酮的浓度为 3 μM。此外，还进行了免疫荧光、western blot 和图像定量分析，以测试鱼藤酮暴露对猪卵母细胞减数分裂成熟、总 ROS 和线粒体 ROS、线粒体功能和生物发生、线粒体自噬和凋亡的影响。进一步的实验表明，鱼藤酮处理通过在猪卵母细胞体外成熟过程中抑制 SIRT1 水平，诱导线粒体功能障碍和线粒体生物发生失败。此外，鱼藤酮处理降低了活性线粒体与总线粒体的比例，增加了 ROS 的产生，并减少了 ATP 的产生。鱼藤酮处理后 LC3 和活性 caspase 3 的水平显著增加，表明鱼藤酮诱导的线粒体功能障碍增加了线粒体自噬，但最终导致细胞凋亡。综上所述，这些结果表明，鱼藤酮通过抑制线粒体功能干扰猪卵母细胞的成熟。
