Department of Biomedical Sciences, CHA University, Seongnam 13488, Korea.
Fertility Center of Gangnam CHA Medical Center, CHA University, Seoul 06125, Korea.
Cells. 2021 Jun 21;10(6):1563. doi: 10.3390/cells10061563.
Advanced maternal age (AMA) is known to be related to the decrease in the quality and quantity of oocytes. Oocyte vitrification is now considered an established assisted reproductive technology for fertility preservation. However, it remains unclear whether the oocytes in older women are more sensitive to various insults during vitrification. Thus, we evaluated whether AMA affects cellular and molecular features and developmental outcomes of oocytes after vitrification in mice. The oocytes were grouped as young fresh (YF), young vitrified/warmed (YV), aged fresh (AF), and aged vitrified/warmed (AV). The survival rate of AV oocytes was significantly lower than that of YV oocytes. The rates of fertilization, cleavage, and blastocyst formation of AV oocytes were significantly lower than those of other groups. AV oocytes were represented as aberrations in mitochondria distribution, microvacuole size, and autophagosome formation, leading to delayed embryo development in mice. This delay was associated with a reduced number of total cells and trophectoderm in the blastocyst developed from AV oocytes. Collectively, AMA exaggerates the vulnerability of oocytes to cryo-damage that occurs during vitrification in mice, suggesting that the current vitrification protocols optimized for oocytes from young females should be modified for oocytes from aged women.
高龄（AMA）已知与卵母细胞质量和数量的下降有关。卵母细胞玻璃化现在被认为是一种成熟的生育力保存辅助生殖技术。然而，目前尚不清楚老年女性的卵母细胞在玻璃化过程中是否对各种损伤更敏感。因此，我们评估了 AMA 是否会影响小鼠卵母细胞玻璃化后的细胞和分子特征以及发育结果。卵母细胞分为年轻新鲜组（YF）、年轻玻璃化/解冻组（YV）、年老新鲜组（AF）和年老玻璃化/解冻组（AV）。AV 卵母细胞的存活率明显低于 YV 卵母细胞。AV 卵母细胞的受精率、卵裂率和囊胚形成率明显低于其他组。AV 卵母细胞表现为线粒体分布、微空泡大小和自噬体形成的异常，导致小鼠胚胎发育延迟。这种延迟与从 AV 卵母细胞发育而来的囊胚中总细胞和滋养外胚层数量减少有关。总之，AMA 夸大了卵母细胞在玻璃化过程中对冷冻损伤的脆弱性，这表明目前针对年轻女性卵母细胞优化的玻璃化方案应针对老年女性的卵母细胞进行修改。
