Data_Sheet_1_Undernutrition-induced substance metabolism and energy production disorders affected the structure and function of the pituitary gland in a pregnant sheep model.docx

IntroductionUndernutrition spontaneously occurs in ewes during late gestation and the pituitary is an important hinge in the neurohumoral regulatory system. However, little is known about the effect of undernutrition on pituitary metabolism.
MethodsHere, 10 multiparous ewes were restricted to a 30% feeding level during late gestation to establish an undernutrition model while another 10 ewes were fed normally as controls. All the ewes were sacrificed, and pituitary samples were collected to perform transcriptome, metabolome, and quantitative real-time PCR analysis and investigate the metabolic changes.
ResultsPCA and PLS-DA of total genes showed that undernutrition changed the total transcriptome profile of the pituitary gland, and 581 differentially expressed genes (DEGs) were identified between the two groups. Clusters of orthologous groups for eukaryotic complete genomes demonstrated that substance transport and metabolism, including lipids, carbohydrates, and amino acids, energy production and conversion, ribosomal structure and biogenesis, and the cytoskeleton were enriched by DEGs. Kyoto encyclopedia of genes and genomes pathway enrichment analysis displayed that the phagosome, intestinal immune network, and oxidative phosphorylation were enriched by DEGs. Further analysis found that undernutrition enhanced the lipid degradation and amino acid transport, repressing lipid synthesis and transport and amino acid degradation of the pituitary gland. Moreover, the general metabolic profiles and metabolic pathways were affected by undernutrition, repressing the 60S, 40S, 28S, and 39S subunits of the ribosomal structure for translation and myosin and actin synthesis for cytoskeleton. Undernutrition was found also to be implicated in the suppression of oxidative phosphorylation for energy production and conversion into a downregulation of genes related to T cell function and the immune response and an upregulation of genes involved in inflammatory reactions enriching phagosomes.
DiscussionThis study comprehensively analyses the effect of undernutrition on the pituitary gland in a pregnant sheep model, which provides a foundation for further research into the mechanisms of undernutrition-caused hormone secretion and metabolic disorders.

研究背景 妊娠晚期母羊可自发出现营养不足，垂体(pituitary)是神经体液调节系统中的关键枢纽。但目前关于营养不足对垂体代谢的影响仍知之甚少。
研究方法 本研究选取10只经产母羊，在妊娠晚期将其饲喂量降至正常水平的30%以构建营养不足模型；另设10只正常饲喂的母羊作为对照。待所有母羊实施安乐死后采集垂体样本，开展转录组(transcriptome)、代谢组(metabolome)及实时定量聚合酶链式反应(quantitative real-time PCR)分析，以探究其代谢变化。
研究结果 对全部基因的主成分分析(Principal Component Analysis, PCA)与偏最小二乘判别分析(Partial Least Squares Discriminant Analysis, PLS-DA)结果显示，营养不足可改变垂体的整体转录组特征，两组间共鉴定出581个差异表达基因(differentially expressed genes, DEGs)。真核生物全基因组直系同源簇聚类分析表明，差异表达基因显著富集于物质转运与代谢（包括脂类(lipids)、碳水化合物(carbohydrates)及氨基酸(amino acids)代谢）、能量产生与转化(energy production and conversion)、核糖体结构与生物发生(ribosomal structure and biogenesis)以及细胞骨架(cytoskeleton)相关通路。京都基因与基因组百科全书(Kyoto Encyclopedia of Genes and Genomes, KEGG)通路富集分析显示，差异表达基因显著富集于吞噬体(phagosome)、肠道免疫网络(intestinal immune network)及氧化磷酸化(oxidative phosphorylation)通路。进一步分析发现，营养不足可增强垂体的脂类降解与氨基酸转运过程，同时抑制脂类合成与转运以及氨基酸降解过程。此外，营养不足还影响了整体代谢特征与代谢通路：抑制了用于翻译过程的核糖体结构亚基（60S、40S、28S及39S亚基）的合成，以及参与细胞骨架构建的肌球蛋白(myosin)与肌动蛋白(actin)的合成。同时，营养不足可通过下调T细胞功能(T cell function)与免疫应答(immune response)相关基因、上调与炎症反应(inflammatory reactions)相关基因，从而抑制能量产生与转化所需的氧化磷酸化过程，最终富集到吞噬体通路。
讨论 本研究通过妊娠绵羊模型，全面分析了营养不足对垂体的影响，为进一步探究营养不足所致激素分泌异常与代谢紊乱的分子机制提供了研究基础。