Endoplasmic reticulum stress attenuation promotes bovine oocyte maturation in vitro
Endoplasmic reticulum stress attenuation promotes bovine oocyte maturation in vitro
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DOI：
10.1530/rep-19-0492
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发表时间：
2020-04-01
期刊：
影响因子：
3.8
通讯作者：
Yamanaka, Ken-ichi
中科院分区：
文献类型：
--
作者：
Khatun, Hafiza;Wada, Yasuhiko;Yamanaka, Ken-ichi
我们以前报道过体外培养过程中内质网（ER）应激的调节会急剧增加牛胚胎的发育速度和低温耐受性；这些数据表明内质网应激是降低体外胚胎质量的关键因素。在目前的后续研究中，我们研究了体外成熟过程中内质网应激衰减是否会影响减数分裂成熟、卵母细胞质量和随后的胚胎发育。牛卵丘细胞复合物（COCs）来源于屠宰场卵巢，分别在0、50、100和200 μ M的选择性内质网应激抑制剂牛磺酸去氧胆酸（TUDCA）的作用下成熟22 h，然后体外受精，受精卵培养8 d。在不同剂量的TUDCA中，100 μ M TUDCA显著提高了脱毛卵母细胞的成熟率，降低了活性氧含量，成熟COCs中凋亡细胞数量减少。随后，TUDCA （100 μ M）处理降低了成熟COCs中GRP78/BIP蛋白水平的定位和数量以及ER应激（GRP78/BIP、PERK、IER1、ATF4和XBP1）和凋亡（CHOP和BAX）相关基因的表达，同时提高了抗凋亡基因BCL2的水平。此外，在IVM期间添加TUDCA （100 μ M）可显著提高囊胚形成率（43.6 +/- 1.8% vs 49.7 +/- 1.3%），减少囊胚凋亡细胞数（7.7 +/- 1.1% vs 5.03 +/- 0.6%）。这些结果表明，成熟过程中内质网应激的存在会损害牛COCs的发育能力，而这一过程可以通过TUDCA逆转。
We have previously reported that regulation of endoplasmic reticulum (ER) stress during in vitro culture acutely increases bovine embryo developmental rate and cryotolerance; these data indicate that ER stress is a critical factor reducing the quality of in vitro-produced embryos. In the current follow-up study, we examined whether ER stress attenuation during in vitro maturation influences meiotic maturation, oocyte quality, and subsequent embryonic development. Bovine cumulus oocyte complexes (COCs) derived from slaughterhouse ovaries were matured with or without tauroursodeoxycholic acid (TUDCA), a selective inhibitor of ER stress (0, 50, 100, and 200 mu M) for 22 h followed by in vitro fertilization, and zygotes were cultured for 8 days. Of the different doses of TUDCA, 100 mu M TUDCA significantly increased the maturation rate, and decreased reactive oxygen species in denuded oocytes, and appeared lower number of apoptotic cells in matured COCs. Subsequently, treatment of TUDCA (100 mu M) decreased the localization and amount of GRP78/BIP protein level as well as ER stress (GRP78/BIP, PERK, IER1, ATF4, and XBP1) and apoptosis (CHOP and BAX)-related gene expression, while it increased the anti-apoptotic gene BCL2 level in matured COCs. Moreover, addition of TUDCA (100 mu M) during IVM significantly improved the blastocyst formation rate (43.6 +/- 1.8% vs 49.7 +/- 1.3%) and decreased the number of apoptotic cells (7.7 +/- 1.1% vs 5.03 +/- 0.6%) in blastocysts. These findings suggest that the presence of ER stress during maturation impairs the developmental competence of bovine COCs and that this process can be reversed by TUDCA.