College of Animal Science and Technology, Jilin Provincial Key Laboratory of Animal Nutrition and Feed Science, and Key Laboratory of Animal Production, Product Quality and Security of Ministry of Education, Jilin Agricultural University, Changchun, 130118, China.
Department of Gastroenterology and Hepatology, Zhongshan Hospital, Fudan University, Shanghai, 200032, China.
Theriogenology. 2022 Sep 1;189:77-85. doi: 10.1016/j.theriogenology.2022.06.013. Epub 2022 Jun 14.
Pyruvate is an important energy substance during early embryonic development of mammals. However, the underlying mechanisms of pyruvate during early embryonic development in pigs and its role in zygotic genome activation (ZGA) are not fully understood. Here, based on a previous RNA-seq dataset of porcine early embryos, we found that pyruvate metabolism-related genes started to be expressed at the 4-cell stage and that pyruvate metabolism-related genes were correlated with porcine ZGA marker genes. To determine the function of pyruvate in porcine embryos, in vitro fertilization (IVF) embryos were cultured in PZM-3 medium (control group); modified PZM-3 medium that only contains pyruvate and lactate plus salts (+P group); or modified PZM-3 medium lacking pyruvate (-P group). The 4-cell arrest rate at 72 h was significantly increased in the -P group compared to the +P group (P < 0.05). In addition, we observed that the reactive oxygen species (ROS) level was significantly increased and that the adenosine triphosphate (ATP) level was significantly (P < 0.05) decreased in the -P group compared to the +P group. Moreover, the expression of ZGA marker genes and SIRT1 protein in embryos was significantly decreased in the -P group compared to the +P group (P < 0.05). Furthermore, the acetylation level of H3K9 was significantly decreased (P < 0.05) and the methylation level of H3K9 was significantly increased (P < 0.05) in the -P group compared to the +P group. In summary, our findings demonstrate that pyruvate affects early embryonic development in pigs by promoting ZGA and reducing oxidative stress levels.
丙酮酸是哺乳动物早期胚胎发育的重要能量物质。然而，丙酮酸在猪早期胚胎发育中的作用及其在合子基因组激活（ZGA）中的作用机制尚不完全清楚。在这里，基于猪早期胚胎的一个先前的 RNA-seq 数据集，我们发现丙酮酸代谢相关基因在 4 细胞阶段开始表达，并且丙酮酸代谢相关基因与猪 ZGA 标记基因相关。为了确定丙酮酸在猪胚胎中的功能，我们将体外受精（IVF）胚胎在 PZM-3 培养基（对照组）中培养；仅含有丙酮酸和乳酸以及盐的改良 PZM-3 培养基（+P 组）；或缺乏丙酮酸的改良 PZM-3 培养基（-P 组）。与+P 组相比，-P 组在 72 小时时 4 细胞阻滞率显著增加（P<0.05）。此外，我们观察到与+P 组相比，-P 组的活性氧（ROS）水平显著升高，三磷酸腺苷（ATP）水平显著降低（P<0.05）。此外，与+P 组相比，-P 组胚胎中 ZGA 标记基因和 SIRT1 蛋白的表达显著降低（P<0.05）。此外，与+P 组相比，-P 组 H3K9 的乙酰化水平显著降低（P<0.05），H3K9 的甲基化水平显著升高（P<0.05）。综上所述，我们的研究结果表明，丙酮酸通过促进 ZGA 和降低氧化应激水平来影响猪的早期胚胎发育。
