Xue Yanfeng, Guo Changzheng, Hu Fan, Liu Junhua, Mao Shengyong
Jiangsu Key Laboratory of Gastrointestinal Nutrition and Animal Health, Laboratory of Gastrointestinal Microbiology, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing 210095, China.
Metabolites. 2018 Nov 27;8(4):85. doi: 10.3390/metabo8040085.
The mechanisms underlying the adaption of liver metabolism to the undernutrition in ewes during late gestation remain unclear. This research aimed to explore the adaptive mechanisms of liver metabolism by hepatic metabolome analysis in pregnant ewes to the negative energy balance induced by severe feed restriction. Twenty ewes carrying multiple fetuses and gestating for 115 days were fed normally or restricted to a 30% feed level (10 ewes in each group) for 15 days. All ewes were sacrificed and hepatic samples were collected and analyzed by liquid chromatography-mass spectrometry. Both the principal components analysis and partial least squares of discriminant analysis of hepatic metabolites showed the clear separation between ewes in the control and severely feed-restricted groups. The metabolic profile demonstrated that the proportions of differential metabolites between the two groups in fatty acids and lipids, organic acids, and amino acids and derivatives were 61.11%, 16.67%, and 11.11%, respectively. Enriched pathways of differential metabolites were mainly involved in fatty acids and amino acids metabolism and biosynthesis. Correlation networks of differential metabolites revealed that general metabolic pattern was changed apparently and mainly based on fatty acids and lipids in the livers of feed-restricted ewes. The accumulation and oxidation of long-chain fatty acids were intensified in the livers of feed-restricted ewes, while those of medium-chain fatty acids were the opposite. In general, severe feed restriction significantly affected the levels of hepatic metabolites and altered the overall metabolic pattern. Furthermore, fatty acids oxidation as well as the utilization of amino acids and organic acids were intensified to adapt to the negative energy balance during late gestation.
妊娠后期母羊肝脏代谢适应营养不足的潜在机制尚不清楚。本研究旨在通过对妊娠母羊进行肝脏代谢组分析，探索肝脏代谢对严重限饲诱导的负能量平衡的适应机制。选取20只怀有多个胎儿、妊娠115天的母羊，分别给予正常饲养或限制在30%的饲喂水平（每组10只），持续15天。所有母羊处死后采集肝脏样本，采用液相色谱-质谱联用仪进行分析。肝脏代谢物的主成分分析和偏最小二乘判别分析均显示，对照组和严重限饲组母羊之间有明显的区分。代谢谱显示，两组之间脂肪酸和脂质、有机酸以及氨基酸及其衍生物的差异代谢物比例分别为61.11%、16.67%和11.11%。差异代谢物的富集途径主要涉及脂肪酸和氨基酸代谢及生物合成。差异代谢物的相关网络表明，限饲母羊肝脏中的总体代谢模式明显改变，且主要基于脂肪酸和脂质。限饲母羊肝脏中长链脂肪酸的积累和氧化增强，而中链脂肪酸则相反。总体而言，严重限饲显著影响肝脏代谢物水平，改变整体代谢模式。此外，脂肪酸氧化以及氨基酸和有机酸的利用增强，以适应妊娠后期的负能量平衡。
