Research Centre for Reproductive Health, Discipline of Obstetrics and Gynaecology, University of Adelaide, Adelaide, South Australia, Australia.
J Assist Reprod Genet. 2013 Jan;30(1):107-16. doi: 10.1007/s10815-012-9898-4. Epub 2012 Dec 18.
Embryos generated from oocytes which have been vitrified have lower blastocyst development rates than embryos generated from fresh oocytes. This is indicative of a level of irreversible damage to the oocyte possibly due to exposure to high cryoprotectant levels and osmotic stress. This study aimed to assess the effects of vitrification on the mitochondria of mature mouse oocytes while also examining the ability of the osmolyte glycine, to maintain cell function after vitrification.
Oocytes were cryopreserved via vitrification with or without 1 mM Glycine and compared to fresh oocyte controls. Oocytes were assessed for mitochondrial distribution and membrane potential as well as their ability to fertilise. Blastocyst development and gene expression was also examined.
Vitrification altered mitochondrial distribution and membrane potential, which did not recover after 2 h of culture. Addition of 1 mM glycine to the vitrification media prevented these perturbations. Furthermore, blastocyst development from oocytes that were vitrified with glycine was significantly higher compared to those vitrified without glycine (83.9 % vs. 76.5 % respectively; p<0.05) and blastocysts derived from oocytes that were vitrified without glycine had significantly decreased levels of IGF2 and Glut3 compared to control blastocysts however those derived from oocytes vitrified with glycine had comparable levels of these genes compared to fresh controls.
Addition of 1 mM glycine to the vitrification solutions improved the ability of the oocyte to maintain its mitochondrial physiology and subsequent development and therefore could be considered for routine inclusion in cryopreservation solutions.
与新鲜卵母细胞产生的胚胎相比，玻璃化冷冻的卵母细胞产生的囊胚发育率较低。这表明卵母细胞可能由于暴露于高浓度的冷冻保护剂和渗透压力下而受到不可逆转的损伤。本研究旨在评估玻璃化对成熟小鼠卵母细胞线粒体的影响，同时研究渗透剂甘氨酸在玻璃化后维持细胞功能的能力。
通过玻璃化冷冻或不添加 1mM 甘氨酸对卵母细胞进行冷冻保存，并与新鲜卵母细胞对照进行比较。评估卵母细胞的线粒体分布和膜电位以及受精能力。还检查了囊胚发育和基因表达。
玻璃化改变了线粒体的分布和膜电位，在 2 小时的培养后无法恢复。在玻璃化培养基中添加 1mM 甘氨酸可防止这些干扰。此外，与未添加甘氨酸的玻璃化卵母细胞相比，添加甘氨酸的玻璃化卵母细胞的囊胚发育率显著更高（分别为 83.9%和 76.5%；p<0.05），并且未添加甘氨酸的玻璃化卵母细胞衍生的囊胚中 IGF2 和 Glut3 的水平明显低于对照囊胚，但添加甘氨酸的玻璃化卵母细胞衍生的囊胚中这些基因的水平与新鲜对照囊胚相当。
在玻璃化溶液中添加 1mM 甘氨酸可改善卵母细胞维持其线粒体生理学和随后发育的能力，因此可考虑将其常规纳入冷冻保存溶液中。
