Wang Mingwen, Xue Jinfeng, Li Chanyi, Qi Lingbin, Nie Lan, Xue Zhigang
Reproductive Medical Center, Tongji Hospital, Tongji University School of Medicine, Shanghai, China.
Department of Infertility and Endocrine, Maternal and Child Health Hospital of Hunan Province, Changsha, China.
Front Cell Dev Biol. 2023 Jul 18;11:1208501. doi: 10.3389/fcell.2023.1208501. eCollection 2023.
The optimization of culture conditions is one of the main strategies to improve the embryo development competence in fertilization (IVF). Glucose is an important carbon source while also exists in the oviductal fluid , the effect of glucose in embryo development microenvironment is still unclear. Here we employed the LC-MS to detect and analyze the metabolites in the culture medium of different cleavage stages including 2-Cell, 4-Cell and 8-Cell mouse embryos, respectively. The effects of the external glucose were estimated by measuring the development rate at different glucose concentrations from 0 to 5 mmol/L, and the gene expression changes were detected to explore the potential mechanism after the addition of glucose in the media. Our results indicated the 2-Cell and 8-Cell stages had defined characteristic metabolites, while 4-Cell stage was the transition state. Global and contiguous metabolic characteristics showed the glycometabolism play a critical role at each early cleavage stages during the embryo development. The 8-Cell rates demonstrated the addition of glucose in culture media significantly improve the embryo competence, the highest rate was 87.33% using 3 mmol/L glucose in media, in contrast only 9.95% using the media without glucose. Meanwhile, the blocked embryos were mainly enriched at 2-Cell stage. Further transcriptome study found 3 mmol/L glucose in media remarkably upregulated the gene expression of lipid biosynthesis at 2-Cell stage, the increased lipid was confirmed by nile red staining. These data indicated the glucose may promote the development competence through increasing the lipid biosynthesis to overcoming the 2-Cell block. Our findings were helpful for the further optimization of IVF culture media, as well as the estimation of embryo quality using metabolites in the culture media.
优化培养条件是提高体外受精（IVF）中胚胎发育能力的主要策略之一。葡萄糖是一种重要的碳源，同时也存在于输卵管液中，其在胚胎发育微环境中的作用仍不清楚。在这里，我们分别采用液相色谱-质谱联用（LC-MS）技术检测和分析了不同卵裂阶段（包括2细胞、4细胞和8细胞小鼠胚胎）培养基中的代谢产物。通过测量0至5 mmol/L不同葡萄糖浓度下的发育率来评估外源葡萄糖的影响，并检测基因表达变化以探索培养基中添加葡萄糖后的潜在机制。我们的结果表明，2细胞和8细胞阶段具有特定的特征代谢产物，而4细胞阶段是过渡状态。整体和连续的代谢特征表明，糖代谢在胚胎发育的每个早期卵裂阶段都起着关键作用。8细胞率表明，培养基中添加葡萄糖显著提高了胚胎能力，培养基中使用3 mmol/L葡萄糖时最高率为87.33%，相比之下，使用不含葡萄糖的培养基时仅为9.95%。同时，阻滞的胚胎主要富集在2细胞阶段。进一步的转录组研究发现，培养基中3 mmol/L葡萄糖在2细胞阶段显著上调了脂质生物合成的基因表达，尼罗红染色证实了脂质的增加。这些数据表明，葡萄糖可能通过增加脂质生物合成来克服2细胞阻滞，从而促进发育能力。我们的研究结果有助于进一步优化IVF培养基，以及利用培养基中的代谢产物评估胚胎质量。
