Postdoctoral workstation, Department of Reproduction and Genetics, Tai'an City Central Hospital, Tai'an, Shandong,China.
Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, College of Animal Science and Veterinary Medicine, Shandong Agricultural University, Tai'an, Shandong, China.
Reproduction. 2021 Jun 16;162(1):95-105. doi: 10.1530/REP-21-0160.
Postovulatory oocyte aging is one of the major causes for human early pregnancy loss and for a decline in the population of some mammalian species. Thus, the mechanisms for oocyte aging are worth exploring. While it is known that ovulated oocytes age within the oviduct and that female stresses impair embryo development by inducing apoptosis of oviductal cells, it is unknown whether the oviduct and/or female stress would affect postovulatory oocyte aging. By comparing aging characteristics, including activation susceptibility, maturation-promoting factor activity, developmental potential, cytoplasmic fragmentation, spindle/chromosome morphology, gene expression, and cumulus cell apoptosis, this study showed that oocytes aged faster in vivo in restraint-stressed mice than in unstressed mice than in vitro. Our further analysis demonstrated that oviductal cells underwent apoptosis with decreased production of growth factors with increasing time after ovulation, and female restraint facilitated apoptosis of oviductal cells. Furthermore, mating prevented apoptosis of oviductal cells and alleviated oocyte aging after ovulation. In conclusion, the results demonstrated that mouse oviducts underwent apoptosis and facilitated oocyte aging after ovulation; female restraint facilitated oocyte aging while enhancing apoptosis of oviductal cells; and copulation ameliorated oviductal apoptosis and oocyte aging.
排卵后卵母细胞衰老（postovulatory oocyte aging）是人类早期妊娠丢失和某些哺乳动物物种数量下降的主要原因之一。因此，研究卵母细胞衰老的机制是值得探索的。虽然已知排卵后的卵母细胞在输卵管内老化，并且女性压力通过诱导输卵管细胞凋亡来损害胚胎发育，但尚不清楚输卵管和/或女性压力是否会影响排卵后卵母细胞的衰老。通过比较衰老特征，包括激活易感性、促成熟因子活性、发育潜能、胞质碎片化、纺锤体/染色体形态、基因表达和卵丘细胞凋亡，本研究表明，与未受应激的小鼠相比，束缚应激的小鼠体内的卵母细胞衰老速度更快，体外培养的卵母细胞衰老速度更慢。我们的进一步分析表明，随着排卵后时间的增加，输卵管细胞凋亡，生长因子的产生减少，而雌性束缚促进了输卵管细胞的凋亡。此外，交配可以防止排卵后输卵管细胞的凋亡，并减轻排卵后卵母细胞的衰老。总之，这些结果表明，小鼠输卵管在排卵后发生凋亡并促进卵母细胞衰老；雌性束缚促进卵母细胞衰老，同时增强输卵管细胞的凋亡；而交配可以改善输卵管细胞凋亡并减轻排卵后卵母细胞的衰老。
