Centre of Excellence in Clinical Embryology, Department of Reproductive Science, Kasturba Medical College, Manipal Academy of Higher Education, Manipal, 576 104, India.
Division of Reproductive Genetics, Department of Reproductive Science, Kasturba Medical College, Manipal Academy of Higher Education, Manipal, 576 104, India.
Reprod Sci. 2024 May;31(5):1420-1428. doi: 10.1007/s43032-024-01462-6. Epub 2024 Jan 31.
Oocyte cryopreservation is offered to women of various age groups for both health and social reasons. Oocytes derived from either controlled ovarian stimulation or in vitro maturation (IVM) are cryopreserved via vitrification. As maternal age is a significant determinant of oocyte quality, there is limited data on the age-related susceptibility of oocytes to the vitrification-warming procedure alone or in conjunction with IVM. In the present study, metaphase II oocytes obtained from 2, 6, 9, and 12 month old Swiss albino mice either by superovulation or IVM were used. To understand the association between maternal age and oocyte cryotolerance, oocytes were subjected to vitrification-warming and compared to non vitrified sibling oocytes. Survived oocytes were evaluated for mitochondrial potential, spindle integrity, relative expression of spindle checkpoint protein transcripts, and DNA double-strand breaks. Maturation potential and vitrification-warming survival were significantly affected (p < 0.001 and p < 0.05, respectively) in ovulated oocytes from the advanced age group but not in IVM oocytes. Although vitrification-warming significantly increased spindle abnormalities in ovulated oocytes from advanced maternal age (p < 0.01), no significant changes were observed in IVM oocytes. Furthermore, Bub1 and Mad2 transcript levels were significantly higher in vitrified-warmed IVM oocytes (p < 0.05). In conclusion, advanced maternal age can have a negative impact on the cryosusceptibility of ovulated oocytes but not IVM oocytes in mice.
卵母细胞冷冻保存因其健康和社会原因而被提供给不同年龄段的女性。通过玻璃化冷冻保存来自控制性卵巢刺激或体外成熟（IVM）的卵母细胞。由于母体年龄是卵母细胞质量的重要决定因素，因此关于卵母细胞对单独玻璃化或与 IVM 联合的玻璃化-解冻过程的年龄相关易感性的数据有限。在本研究中，使用了通过超数排卵或 IVM 从 2、6、9 和 12 个月大的瑞士白化小鼠中获得的中期 II 卵母细胞。为了了解母体年龄与卵母细胞冷冻耐受性之间的关系，将卵母细胞进行玻璃化-解冻，并与未玻璃化的同胞卵母细胞进行比较。对幸存的卵母细胞进行线粒体潜能、纺锤体完整性、纺锤体检查点蛋白转录物的相对表达和 DNA 双链断裂的评估。成熟潜能和玻璃化-解冻存活率在高龄组的排卵卵母细胞中受到显著影响（p<0.001 和 p<0.05，分别），但在 IVM 卵母细胞中不受影响。尽管玻璃化-解冻显著增加了高龄母体排卵卵母细胞中的纺锤体异常（p<0.01），但在 IVM 卵母细胞中未观察到显著变化。此外，Bub1 和 Mad2 转录物水平在玻璃化-解冻的 IVM 卵母细胞中显著升高（p<0.05）。总之，高龄母体年龄可能对排卵卵母细胞的冷冻敏感性产生负面影响，但对小鼠的 IVM 卵母细胞没有影响。
