SARA产生的内源性LPS对结肠黏膜上皮细胞凋亡的影响及GCs的参与

项目名称： SARA产生的内源性LPS对结肠黏膜上皮细胞凋亡的影响及GCs的参与

项目编号： No.31272470

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 农业科学

项目作者： 倪迎冬

作者单位： 南京农业大学

项目金额： 80万元

中文摘要： 由于缺乏优质牧草，常给奶牛饲喂高比例谷物精料以满足高产奶的需求，而导致亚急性瘤胃酸中毒（SARA）的发生。SARA时瘤胃和后段肠道内G-菌大量裂解并释放菌壁成分-脂多糖（LPS），超出肠道脱毒能力而致LPS移位至血液，引起内毒素血症和全身性炎症反应。体内营养物质发生"重分配"，由血液入乳腺的乳成分前体物减少，导致乳质和量降低。因此，消化腔内LPS移位是SARA造成乳质量下降的关键环节。迄今，有关LPS移位的解剖位置尚无定论。与瘤胃相比，后段肠道更为易"漏"。SARA产生的LPS如何损伤肠黏膜屏障？机体如何对抗这一损伤？本课题以萨能奶山羊为动物模型，首次研究高比例谷物精料诱发SARA时结肠腔内LPS对黏膜上皮细胞凋亡的影响，以及糖皮质激素（GCs）对此过程的抵抗作用与信号通路。本项目以整合生理学基本原理为指导，深入研究反刍动物慢性酸中毒时尚待解决的科学问题,为该病的防治提供靶点和理论依据。

中文关键词： 亚急性瘤胃酸中毒；脂多糖；糖皮质激素；细胞凋亡；上皮细胞

英文摘要： Due to lack of quality forage, dairy cows are usually fed with a high proportion of grain concentrate to meet the needs of high milk production. Subacute ruminal acidosis (SARA) is often induced because of the rapid fermentation of grain concentrate in the rumen. When SARA occurs, a large amount bacterial endotoxin (lipopolysaccharide, LPS) is released in the rumen and the large intestine, which is far beyond the intestinal detoxification ability, then resulting in LPS translocation to the bloodstream and causing endotoxemia as well as. Nutrients repartipation in the body occurs during systemic inflammation caused by SARA, which will reduce the precursors of milk composition from the blood into the mammary gland, and ultimately lead to lower milk quality and milk production. Therefore, LPS translocation from the digestive tract into blood is the key process to affect milk quality during SARA. To date, the site of LPS translocation has not been determined, however, lower gut is much more "leaky" because of the monolayer structure compared to the rumen. How does LPS damage the intestinal mucosal barrier during SARA? How to defense this damage by the body? In this project, Saanen dairy goat during lactation period was employed as an animal model, it is the first time to investigate the effects of LPS produced in co

英文关键词： SARA；LPS；Glucocorticoids；Cell apoptosis；Epithelial cell