Yuan Bao, Liang Shuang, Kwon Jeong-Woo, Jin Yong-Xun, Park Shun-Ha, Wang Hai-Yang, Sun Tian-Yi, Zhang Jia-Bao, Kim Nam-Hyung
Department of Laboratory Animals, College of Animal Sciences, Jilin University, Changchun, Jilin, China.
Molecular Embryology Laboratory, Department of Animal Sciences, Chungbuk National University, Cheongju, Chungbuk, South Korea.
PLoS One. 2016 Dec 20;11(12):e0168329. doi: 10.1371/journal.pone.0168329. eCollection 2016.
In the present study, we investigated the potential role of glucose and pyruvate in the cytoplasmic maturation of porcine oocytes by investigating the effect of glucose and/or pyruvate supplementation, in the presence or absence of 10% porcine follicular fluid (PFF), on meiotic maturation and subsequent embryo development. In the absence of 10% PFF, without exogenous addition of glucose and pyruvate, the medium seemed unable to support maturation. In the presence of 10% PFF, the addition of 5.6 mM glucose and/or 2 mM pyruvate during in vitro maturation of cumulus enclosed oocytes increased MII oocyte and blastocyst rates. In contrast, oocytes denuded of cumulus cells were not able to take full advantage of the glucose in the medium, as only pyruvate was able to increase the MII rate and the subsequent early embryo developmental ability. Treatment of cumulus enclosed oocytes undergoing maturation with 200 μM dehydroepiandrosterone (DHEA), a pentose phosphate pathway inhibitor, or 2 μM iodoacetate (IA), a glycolysis inhibitor, significantly reduced GHS, intra-oocyte ATP, maternal gene expression, and MPF activity levels. DHEA was also able to increase ROS and reduce the levels of NADPH. Moreover, blastocysts of the DHEA- or IA-treated groups presented higher apoptosis rates and markedly lower cell proliferation cell rates than those of the non-treated group. In conclusion, our results suggest that oocytes maturing in the presence of 10% PFF can make full use of energy sources through glucose metabolism only when they are accompanied by cumulus cells, and that pentose phosphate pathway (PPP) and glycolysis promote porcine oocyte cytoplasmic maturation by supplying energy, regulating maternal gene expression, and controlling MPF activity.
在本研究中，我们通过研究在添加或不添加10%猪卵泡液（PFF）的情况下补充葡萄糖和/或丙酮酸对减数分裂成熟及随后胚胎发育的影响，来探究葡萄糖和丙酮酸在猪卵母细胞细胞质成熟中的潜在作用。在没有10%PFF且未外源添加葡萄糖和丙酮酸的情况下，该培养基似乎无法支持成熟。在有10%PFF存在时，在卵丘包裹的卵母细胞体外成熟过程中添加5.6 mM葡萄糖和/或2 mM丙酮酸可提高MII期卵母细胞率和囊胚率。相比之下，去除卵丘细胞的卵母细胞无法充分利用培养基中的葡萄糖，因为只有丙酮酸能够提高MII期率和随后的早期胚胎发育能力。用200 μM脱氢表雄酮（DHEA，一种磷酸戊糖途径抑制剂）或2 μM碘乙酸盐（IA，一种糖酵解抑制剂）处理正在成熟的卵丘包裹的卵母细胞，会显著降低谷胱甘肽（GHS）、卵母细胞内ATP、母源基因表达和MPF活性水平。DHEA还能够增加活性氧（ROS）并降低烟酰胺腺嘌呤二核苷酸磷酸（NADPH）水平。此外，DHEA或IA处理组的囊胚凋亡率更高，细胞增殖率明显低于未处理组。总之，我们的结果表明，在10%PFF存在下成熟的卵母细胞只有在伴有卵丘细胞时才能通过葡萄糖代谢充分利用能量来源，并且磷酸戊糖途径（PPP）和糖酵解通过提供能量、调节母源基因表达和控制MPF活性来促进猪卵母细胞的细胞质成熟。
