糖蛋白参与仔猪肠道发育和免疫调节的分子机制

Weaning stress is a crucial challenge for modern breeding industry. It could induce disorders of piglet gut functions and damages of intestinal immunologic barrier. Glycosylated protein is an important type of post-modified protein, involving in animal development, immune response and adhesion of pathogens, etc. To understand the mechanism of glycosylated protein taking part in intestinal development and immunomodulation under weaning stress, this project tries to discover the key proteins and glycosylated proteins involving in the process of intestinal development and immunomodulation via glycoproteomics technologies, mainly followed three constructions: 1) discovering the key glycoproteins involving in intestinal development and immunomodulation; 2) analyzing the relationship between glycoform and biological functions; 3)studying the changes of glycosylated sites and glycoform of intestinal mucins and sIgA under different development stages and weaning immunomodulation.Through the implementation of this project, a glycosylated protein network of intestinal regulation responding weaning stress was developed, which could elaborate the mechanism of piglet gut development and immune defense at the protein level. It would provide a basis for disease preventing by nutritional intervention.

早期断奶应激是引起仔猪肠道功能紊乱和免疫屏障受损的主要诱因，是养殖业亟需解决的一个重大问题。糖蛋白广泛参与机体的生长发育和免疫调控等生命过程。为研究初生仔猪肠道发育和免疫调控过程中糖蛋白的作用机制，本项目使用糖蛋白组学技术解析仔猪发育和断奶应激免疫调控过程中关键的糖蛋白，依次开展三个方面研究：1）挖掘初生仔猪肠道发育和断奶应激下肠道免疫调控过程中关键糖蛋白；2）分析在关键糖蛋白的生物调节功能与糖链结构之间的联系；3）解析黏蛋白和sIgA在肠道发育和免疫调控过程中糖基化位点和糖链结构的变化。通过系统地分析糖蛋白在肠道发育和断奶应激免疫调控过程中的作用，明确其修饰位点和糖链结构的变化对糖蛋白生物功能的影响，最终建立糖蛋白参与的仔猪肠道发育和断奶应激免疫调控网络，在蛋白及翻译后修饰水平阐述仔猪肠道的发育规律和断奶应激免疫调控机制，为仔猪断奶后营养干预和疾病防治提供理论依据。

早期断奶应激是引起仔猪肠道功能紊乱和免疫屏障受损的主要诱因，是养殖业亟需解决的一个重大问题。蛋白质广泛参与机体的生长发育和免疫调控等生命过程,为研究初生仔猪肠道发育和免疫调控过程中蛋白和糖蛋白的作用机制，通过组织染色和单细胞测序绘制了仔猪出生后不同时期以及断奶对肠道形态、黏膜内细胞类型动态变化图谱。使用定量蛋白质学，分析了初生仔猪0-21天仔猪肠道发育过程中的蛋白种类的变化，共鉴定到8260个蛋白和847个显著差异表达蛋白，差异表达蛋白主要参与能量代谢、氧化应激、脂质代谢等过程参与肠道发育和免疫调控。使用糖蛋白组学技术，鉴定到383个糖蛋白、519个糖肽和3629个糖型，通过分析糖蛋白的功能，所鉴定到的糖蛋白主要参与免疫调控，蛋白定位，细胞原件组装、信号传导和细胞迁移等生物过程。断奶应激引起的腹泻仔猪内的糖链合成基因表达的化，进一步说明腹泻仔猪结肠黏蛋白糖基化修饰发生改变，糖链变短。通过本项目的实施，初步阐明不同类型糖蛋白参与的仔猪肠道发育和断奶应激免疫调控的分子机制，为今后早期仔猪断奶后营养调控提供了理论知识。