Three‐dimensional (3D) culture provides a biomimicry of the naive microenvironment that can support cell proliferation, differentiation, and regeneration. Some growth factors, such as epidermal growth factor (EGF), facilitate normal meiosis during oocyte maturation in vivo. In this study, a scaffold‐based 3D coculture system using purified alginate was applied to induce oocyte differentiation from mouse embryonic stem cells (mESCs). mESCs were induced to differentiate into oocyte‐like cells using embryoid body protocol in the two‐dimensional or 3D microenvironment in vitro. To increase the efficiency of the oocyte‐like cell differentiation from mESCs, we employed a coculture system using ovarian granulosa cells in the presence or absence of epidermal growth factor (+EGF or −EGF) for 14 days and then the cells were assessed for germ cell differentiation, meiotic progression, and oocyte maturation markers. The cultures exposed to EGF in the alginate‐based 3D microenvironment showed the highest level of premeiotic (Oct4 and Mvh), meiotic (Scp1, Scp3, Stra8, and Rec8), and oocyte maturation (Gdf9, Cx37, and Zp2) marker genes (p < .05) in comparison to other groups. According to the gene‐expression patterns, we can conclude that alginate‐based 3D coculture system provided a highly efficient protocol for oocyte‐like cell differentiation from mESCs. The data showed that this culture system along with EGF improved the rate of in vitro oocyte‐like cell differentiation.

中文翻译：

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表皮生长因子和三维支架为小鼠胚胎干细胞分化为卵母细胞样细胞提供了有利的环境。

三维（3D）培养提供了可以支持细胞增殖，分化和再生的原始微环境的仿生生物。一些生长因子，例如表皮生长因子（EGF），可促进体内卵母细胞成熟过程中的正常减数分裂。在这项研究中，使用了基于支架的3D共培养系统，该系统使用纯化的藻酸盐诱导小鼠胚胎干细胞（mESCs）分化为卵母细胞。在体外二维或3D微环境中，使用胚状体方案诱导mESC分化为卵母细胞样细胞。为了提高mESCs分化成卵母细胞的效率，我们使用存在或不存在表皮生长因子（+ EGF或-EGF）的卵巢颗粒细胞共培养系统14天，然后评估细胞的生殖细胞分化，减数分裂进程和卵母细胞成熟标记。在基于藻酸盐的3D微环境中暴露于EGF的培养物显示出最高水平的减数分裂前期（与其他组相比，Oct4和Mvh），减数分裂（Scp1，Scp3，Stra8和Rec8）和卵母细胞成熟（Gdf9，Cx37和Zp2）标记基因（p  <.05）。根据基因表达模式，我们可以得出结论，基于藻酸盐的3D共培养系统为从mESCs分化为卵母细胞样细胞提供了高效协议。数据表明，这种培养系统与EGF一起提高了体外卵母细胞样细胞分化的速率。