Baniasadi F, Hajiaghalou S, Shahverdi A, Pirhajati V, Fathi R
Department of Embryology, Reproductive Biomedicine Research Center, Royan Institute for Reproductive Biomedicine, ACECR, Tehran, Iran.
Department of Anatomy, Iran University of medical Science, Tehran, Iran.
Theriogenology. 2021 Mar 15;163:31-42. doi: 10.1016/j.theriogenology.2020.12.025. Epub 2021 Jan 3.
This study was performed with the aim of evaluating the influence of static magnetic field (SMF) of 60 mT on mouse Cumulus Oocytes Complexes (COCs) vitrification. The COCs were vitrified in the presence (Vit_SMF) and absence of SMF (Vit_SMF). Along with these groups, non-vitrified or fresh COCS, which exposed (nVit_SMF) and non-exposed (nVit_SMF) to magnetic field, were also considered. Survival and viability rates and mitochondrial activity as well as ultrastructure of oocytes were examined by trypan blue Staining (TBS), Annexin-PI Staining, JC1 staining and transition electron microscopy, respectively. Following in vitro fertilization (IVF) and embryo development, gene expression was carried out through qRT-PCR at blastocyst (BL) stage. The survival rate in Vit_SMF and Vit_SMF decreased meaningfully in comparison with nVit_SMF (P < 0.05), but there was no significant difference between SMF and SMF groups. The mitochondrial activity in Vit_SMF was significantly reduced compared to the nVit_SMF group (P < 0.05), however its value in Vit_SMF returned to the control level. Ultrastructural study demonstrated that SMF could protect the COCs from cryoinjuries and reduced damaged features in ooplasm of the vitrified oocytes. There was no significant difference in fertilization rate. Although, BL formation was the highest rate in the Vit_SMF group, it was just substantially higher than the non-vitrified groups (P < 0.05). The significant changes of Oct4, Cdx2 and Nanog genes expression due to vitrification (Vit_SMF) or SMF (nVit_SMF) treatments (P < 0.05) as compared to control (nVit_SMF), returned to the natural level after using SMF in vitrified derived blastocysts (Vit_SMF). Totally based on the results, it is clear that static magnetic field improves mitochondrial potential activity and ultrastructure of mouse vitrified COCs. In addition, SMF enhances the embryo cleavage rate to blastocyst stage and modulates pluripotency in blastocyst embryos derived from vitrified COCs.
本研究旨在评估60 mT静磁场（SMF）对小鼠卵丘卵母细胞复合体（COCs）玻璃化的影响。COCs在有SMF（Vit_SMF）和无SMF（Vit_SMF）的情况下进行玻璃化。除了这些组，还考虑了未玻璃化或新鲜的COCS，即暴露于磁场（nVit_SMF）和未暴露于磁场（nVit_SMF）的情况。分别通过台盼蓝染色（TBS）、膜联蛋白 - PI染色、JC1染色和透射电子显微镜检查卵母细胞的存活率和活力率、线粒体活性以及超微结构。体外受精（IVF）和胚胎发育后，在囊胚（BL）阶段通过qRT - PCR进行基因表达分析。与nVit_SMF相比，Vit_SMF和Vit_SMF中的存活率显著降低（P < 0.05），但SMF组和SMF组之间没有显著差异。与nVit_SMF组相比，Vit_SMF中的线粒体活性显著降低（P < 0.05），但其在Vit_SMF中的值恢复到对照水平。超微结构研究表明，SMF可以保护COCs免受冷冻损伤，并减少玻璃化卵母细胞卵质中的损伤特征。受精率没有显著差异。虽然，BL形成率在Vit_SMF组中最高，但仅显著高于未玻璃化组（P < 0.05）。与对照（nVit_SMF）相比，由于玻璃化（Vit_SMF）或SMF（nVit_SMF）处理导致的Oct4、Cdx2和Nanog基因表达的显著变化（P < 0.05），在玻璃化衍生的囊胚（Vit_SMF）中使用SMF后恢复到自然水平。总体而言，根据结果清楚地表明，静磁场可改善小鼠玻璃化COCs的线粒体潜在活性和超微结构。此外，SMF提高了胚胎分裂到囊胚阶段的速率，并调节了来自玻璃化COCs的囊胚胚胎中的多能性。
