乙醇胺在早期断奶仔猪肠道黏膜损伤修复中的作用及机制研究

Weaning stress is the main issue which causes growth retardation in piglets, as well as jeopardizes intestinal mucosa morphology and configuration. Ethanolamine is biologically active and excreted in breast milk, which is the component of the cell membrane and can promote the proliferation of liver cells and liver regeneration. Our previous studies showed that concentration of ethanolamine was significantly changed in the differentiation process of 21 days sucking piglets jejunum villus, and can significantly promote the proliferation of intestinal epithelial cell in vitro and decrease the feed to grain ratio in 21 days weaned rats. However, little is known about physiological function of ethanolamine in pig intestines. So this project will focus on the effect of ethanolamine on the small intestinal morphology, intestinal epithelial cell proliferation, differentiation and apoptosis in 21 days weaned piglets. The activities of enzymes associated with the digestive functions, intestinal mucosal barrier and expression of tight junction protein will be measured, and the results will disclosure the mechanism of ethanolamine on rapid recovering from intestinal injury through the lipid composition analysis of intestinal epithelia cell membrane, proteomics and bioinformatics. Our results will also offer a novel theoretical basis for exploring new regulation agent of weaning stress, improving the nutrition status of piglets and management measures during the weaning period.

断奶应激是制约仔猪生长的一个关键因素,它能引起小肠黏膜形态结构和功能的变化，造成小肠黏膜损伤。乙醇胺是母乳中存在的一种生物活性物质及细胞膜磷脂的组成分子，可促进肝脏上皮细胞增殖和肝再生。我们的前期研究表明，21日龄哺乳仔猪空肠绒毛细胞分化过程中乙醇胺的浓度变化明显，且它可显著促进体外培养肠上皮细胞的增殖及降低21天断奶大鼠的料重比。但目前乙醇胺对猪肠道的生理功能尚未清楚，据此，本项目以21日龄断奶仔猪为试验对象,研究了乙醇胺对断奶仔猪小肠黏膜形态、肠上皮细胞的增殖、分化和凋亡、刷状缘膜消化酶活性、肠道屏障和紧密连接蛋白表达的影响，并通过肠上皮细胞膜脂质组成分析、蛋白质组学和生物信息学探索了乙醇胺对肠道损伤修复影响的内在机制，为探讨仔猪断奶应激的新型调控剂、改进断奶期营养和管理措施提供理论依据。

乙醇胺来源于大豆磷脂和母乳，它可以通过CDP-乙醇胺途径合成细胞膜磷脂酰乙醇胺，也被许多肠道细菌利用作为碳源或氮源，从而影响这些细菌的定植和适应以及肠道微生态平衡。本研究的细胞结果表明，外源添加乙醇胺可能通过影响线粒体的功能和mTOR信号通路来影响肠上皮细胞IPEC-J2的增殖；本研究的动物实验表明，外源添加乙醇胺能促进21日龄断奶大鼠和断奶仔猪的生长性能，但对动物机体生长性能的影响需要结合稳定日粮配方和肠道微生态研究进一步深入探讨。