Follicle Biology Laboratory, Vrije Universiteit Brussel (VUB), 1090, Brussels, Belgium.
Fertility & Research Centre, School of Women's and Children's Health, University of New South Wales Sydney, Sydney, NSW, 2052, Australia.
J Assist Reprod Genet. 2022 Jan;39(1):127-140. doi: 10.1007/s10815-021-02382-z. Epub 2022 Jan 4.
In vitro maturation (IVM) is a technology that generates mature oocytes following culture of immature cumulus-oocyte complexes (COC) in vitro. IVM is characterized by minimal patient stimulation, making it attractive for certain patient groups. Recently, a biphasic IVM system, capacitation (CAPA)-IVM, has shown improved clinical outcomes relative to standard IVM; however, it remains less efficient than IVF. This study assessed whether supplementation of CAPA-IVM culture media with the novel TGFβ superfamily proteins cumulin and super-GDF9 improves subsequent mouse embryo development.
Immature mouse COCs were cultured by standard IVM or biphasic IVM ± cumulin or super-GDF9.
Both cumulin and super-GDF9 in standard IVM significantly improved day-6 blastocyst rate (53.9% control, 73.6% cumulin, 70.4% super-GDF9; p = 0.006; n = 382-406 oocytes). Cumulin or super-GDF9 in CAPA-IVM did not alter embryo yield or blastocyst cell allocation in an unstimulated model. Moreover, cumulin did not alter these outcomes in a mild PMSG stimulation model. Cumulin in CAPA-IVM significantly increased cumulus cell expression of cumulus expansion genes (Ptgs2, Ptx3, Adamts1, Gfat2) and decreased Lhr expression relative to control. However, cumulin-induced mRNA expression of cumulus cell (Ptgs2, Ptx3) and oocyte genes (Gdf9, Bmp15, Oct4, Stella) in CAPA-IVM remained significantly lower than that of in vivo matured cells.
Cumulin did not provide an additional beneficial effect in biphasic IVM in terms of blastocyst yield and cell allocation; however in standard IVM, cumulin and super-GDF9 significantly improve oocyte developmental competence.
体外成熟（IVM）是一种通过体外培养不成熟卵丘-卵母细胞复合物（COC）来产生成熟卵母细胞的技术。IVM 的特点是对患者的刺激最小，因此对某些患者群体具有吸引力。最近，一种双相 IVM 系统，即获能（CAPA）-IVM，与标准 IVM 相比显示出了改善的临床结局；然而，它的效率仍然低于 IVF。本研究评估了在 CAPA-IVM 培养物中添加新型 TGFβ 超家族蛋白 cumulin 和 super-GDF9 是否能改善随后的小鼠胚胎发育。
通过标准 IVM 或双相 IVM 培养不成熟的小鼠 COC，然后在培养物中添加 cumulin 或 super-GDF9。
在标准 IVM 中，cumulin 和 super-GDF9 都显著提高了第 6 天的囊胚率（对照组为 53.9%，cumulin 组为 73.6%，super-GDF9 组为 70.4%；p=0.006；n=382-406 个卵母细胞）。CAPA-IVM 中的 cumulin 或 super-GDF9 并未改变未刺激模型中的胚胎产量或囊胚细胞分配。此外，cumulin 在轻度 PMSG 刺激模型中也没有改变这些结果。在 CAPA-IVM 中，cumulin 显著增加了 cumulus 细胞中 cumulus 扩张基因（Ptgs2、Ptx3、Adamts1、Gfat2）的表达，并降低了相对对照组的 Lhr 表达。然而，cumulin 在 CAPA-IVM 中诱导的 cumulus 细胞（Ptgs2、Ptx3）和卵母细胞基因（Gdf9、Bmp15、Oct4、Stella）的 mRNA 表达仍明显低于体内成熟细胞。
在囊胚产量和细胞分配方面，cumulin 在双相 IVM 中没有提供额外的有益效果；然而，在标准 IVM 中，cumulin 和 super-GDF9 显著提高了卵母细胞的发育能力。
