Department of Animal Science & Biotechnology, Research Center for Transgenic Cloned Pigs, Chungnam National University, Daejeon, Republic of Korea.
Department of Animal Resource Development, National Institute of Animal Science, Cheonan, Republic of Korea.
Mol Reprod Dev. 2018 Aug;85(8-9):665-681. doi: 10.1002/mrd.23052. Epub 2018 Oct 5.
Poor-quality oocytes (those with 1-2 layers of cumulus cells) typically possess low meiotic competence and development. Prolonging the duration of in vitro maturation (IVM; 52 hr) can enhance the maturation rate of poor-quality oocytes, but it does not improve subsequent embryonic development. This likely reflects the increased reactive oxygen species (ROS) production and apoptosis seen in these oocytes compared with the non-prolonged IVM (44 hr) group. Melatonin is a free radical scavenger, anti-oxidant and anti-apoptotic agent that reported to enhance the quality of embryos by inhibiting ROS generation and apoptosis. Therefore, we herein investigated whether melatonin combined with prolonged IVM (52 hr) could improve the quality and development of poor-quality oocytes. We supplemented IVM and/or in vitro culture (IVC) media with various concentrations (0, 10 , 10 , 10 M) of melatonin, and estimated parameters related to oocyte quality and development. The addition of melatonin (10 M) to a prolonged IVM system improved the oocyte quality and development compared with those of the melatonin-free poor-quality oocytes group, and that this was due to decreases in ROS generation, apoptosis, and DNA damage. When melatonin was added during both IVM (10 M) and IVC (10 M), we observed a cumulative positive influence on the embryonic development and quality; this treatment enhanced the expression level of Oct4 and decreased the levels of ROS, DNA damage, and apoptosis. Together, these findings suggest that the combination of melatonin plus prolonged IVM can improve the quality and development of poor-quality porcine oocytes via anti-oxidative and anti-apoptotic effects.
质量较差的卵母细胞（仅有 1-2 层卵丘细胞）通常具有较低的减数分裂能力和发育能力。延长体外成熟（IVM；52 小时）的时间可以提高质量较差的卵母细胞的成熟率，但不能改善随后的胚胎发育。这可能反映了与非延长 IVM（44 小时）组相比，这些卵母细胞中活性氧（ROS）产生和细胞凋亡增加。褪黑素是一种自由基清除剂、抗氧化剂和抗凋亡剂，据报道，它通过抑制 ROS 生成和细胞凋亡来提高胚胎质量。因此，我们在此研究了褪黑素与延长 IVM（52 小时）相结合是否可以改善质量较差的卵母细胞的质量和发育。我们用不同浓度（0、10 、10 、10 M）的褪黑素补充 IVM 和/或体外培养（IVC）培养基，并评估与卵母细胞质量和发育相关的参数。与无褪黑素的质量较差的卵母细胞组相比，在延长的 IVM 系统中添加褪黑素（10 M）可改善卵母细胞的质量和发育，这是由于 ROS 生成、细胞凋亡和 DNA 损伤减少所致。当在 IVM（10 M）和 IVC（10 M）期间都添加褪黑素时，我们观察到对胚胎发育和质量的累积积极影响；这种处理增强了 Oct4 的表达水平，并降低了 ROS、DNA 损伤和细胞凋亡的水平。总之，这些发现表明，褪黑素加延长 IVM 的组合可以通过抗氧化和抗凋亡作用来改善质量较差的猪卵母细胞的质量和发育。
