Faculty of Life and Environmental Sciences, University of Yamanashi, Yamanashi, Japan.
Advanced Biotechnology Center, University of Yamanashi, Kofu-shi, Yamanashi, Japan.
PLoS One. 2018 Aug 27;13(8):e0202962. doi: 10.1371/journal.pone.0202962. eCollection 2018.
Cumulus-free in vitro maturation (IVM) provides a powerful tool to manipulate immature oocytes, but IVM oocytes lead to poor development after fertilization. Supplementation of the culture medium with tauroursodeoxycholic acid (TUDCA), a bile acid, has been reported to improve the development of embryos derived from in vivo fertilized (IVF) embryos after in vitro culture (IVC) by attenuating endoplasmic reticulum stress. However, it remains unclear if TUDCA can improve development of IVM-IVF embryos. Here, we examined whether TUDCA treatment could improve embryonic development during or after IVM. Immature GV oocytes collected from ovaries of ICR female mice that were free from cumulus cells were subjected to IVM in αMEM containing 5% FBS for 16 h. TUDCA was added to the media at varying concentrations (0-1000 μM) during IVM and IVC. TUDCA treatment during IVM reduced both MII and pronuclear (PN) rates but did not affect blastocyst rates of fertilized embryos. In contrast, TUDCA treatment during IVC significantly increased blastocyst formation rates in a concentration dependent manner. Finally, embryo transfer after TUDCA treatment revealed a significant improvement in the rates of offspring production (15% with 1000 μM TUDCA vs. 6.0% control). These results show that treatment with 1000 μM of TUDCA significantly can improve poor embryonic development of cumulus-free IVM-IVF embryos.
无卵丘体外成熟（IVM）为操作不成熟卵母细胞提供了有力工具，但 IVM 卵母细胞受精后发育不良。据报道，在体外培养（IVC）过程中，在培养基中添加牛磺熊脱氧胆酸（TUDCA），一种胆盐，可以减轻内质网应激，从而改善体内受精（IVF）胚胎衍生的胚胎发育。然而，TUDCA 是否能改善 IVM-IVF 胚胎的发育尚不清楚。在这里，我们研究了 TUDCA 处理是否可以改善 IVM 期间或之后胚胎的发育。从无卵丘的 ICR 雌性小鼠卵巢中收集的不成熟GV 卵母细胞在含有 5% FBS 的αMEM 中进行 16 小时 IVM。在 IVM 和 IVC 期间，TUDCA 以不同浓度（0-1000μM）添加到培养基中。IVM 期间的 TUDCA 处理降低了 MII 和原核（PN）率，但不影响受精胚胎的囊胚率。相比之下，TUDCA 处理在 IVC 中以浓度依赖的方式显著增加囊胚形成率。最后，TUDCA 处理后的胚胎移植显示出后代生产率的显著提高（1000μM TUDCA 组为 15%，对照组为 6.0%）。这些结果表明，用 1000μM 的 TUDCA 处理可以显著改善无卵丘 IVM-IVF 胚胎的不良胚胎发育。
