State Key Laboratory of Animal Biotech Breeding, National Engineering Laboratory for Animal Breeding, Key Laboratory of Animal Genetics, Breeding and Reproduction of the Ministry of Agriculture, College of Animal Science and Technology, China Agricultural University, Beijing 100193, China.
Int J Mol Sci. 2024 Sep 1;25(17):9521. doi: 10.3390/ijms25179521.
In vitro embryonic technology is crucial for improving farm animal reproduction but is hampered by the poor quality of oocytes and insufficient development potential. This study investigated the relationships among changes in the gut microbiota and metabolism, serum features, and the follicular fluid metabolome atlas. Correlation network maps were constructed to reveal how the metabolites affect follicular development by regulating gene expression in granulosa cells. The superovulation synchronization results showed that the number of follicle diameters from 4 to 8 mm, qualified oocyte number, cleavage, and blastocyst rates were improved in the dairy heifers (DH) compared with the non-lactating multiparous dairy cows (NDC) groups. The gut microbiota was decreased in , , and , but increased in , , , , and in the NDC group, which was highly associated with phospholipid-related metabolites of gut microbiota and serum. Metabolomic profiling of the gut microbiota, serum, and follicular fluid further demonstrated that the co-metabolites were phosphocholine and linoleic acid. Moreover, the expression of genes related to arachidonic acid metabolism in granulosa cells was significantly correlated with phosphocholine and linoleic acid. The results in granulosa cells showed that the levels of PLCB1 and COX2, participating in arachidonic acid metabolism, were increased in the DH group, which improved the concentrations of PGD and PGF in the follicular fluid. Finally, the expression levels of apoptosis-related proteins, cytokines, and steroidogenesis-related genes in granulosa cells and the concentrations of steroid hormones in follicular fluid were determinants of follicular development. According to our results, gut microbiota-related phosphocholine and linoleic acid participate in arachidonic acid metabolism in granulosa cells through the gut-follicle axis, which regulates follicular development. These findings hold promise for enhancing follicular development and optimizing oocyte quality in subfertile dairy cows.
体外胚胎技术对于提高农场动物繁殖至关重要，但受到卵母细胞质量差和发育潜力不足的阻碍。本研究调查了肠道微生物群和代谢变化、血清特征以及卵泡液代谢组图谱之间的关系。构建关联网络图谱以揭示代谢物如何通过调节颗粒细胞中的基因表达来影响卵泡发育。超数排卵同步结果表明，与非泌乳经产奶牛（NDC）组相比，奶牛（DH）组的卵泡直径从 4 到 8 毫米的数量、优质卵母细胞数量、卵裂和囊胚率均得到改善。NDC 组中的肠道微生物群减少了、、和，而增加了、、、、和，这与肠道微生物群和血清中与磷脂相关的代谢物高度相关。肠道微生物群、血清和卵泡液的代谢组学分析进一步表明，共代谢物为磷酸胆碱和亚油酸。此外，颗粒细胞中与花生四烯酸代谢相关的基因表达与磷酸胆碱和亚油酸显著相关。颗粒细胞中的结果表明，DH 组中参与花生四烯酸代谢的 PLCB1 和 COX2 基因表达水平增加，从而提高了卵泡液中 PGD 和 PGF 的浓度。最后，颗粒细胞中凋亡相关蛋白、细胞因子和类固醇生成相关基因的表达水平以及卵泡液中类固醇激素的浓度是卵泡发育的决定因素。根据我们的结果，肠道微生物群相关的磷酸胆碱和亚油酸通过肠道-卵泡轴参与颗粒细胞中的花生四烯酸代谢，从而调节卵泡发育。这些发现为提高不孕奶牛的卵泡发育和优化卵母细胞质量提供了希望。
