AMPK和mTORC1介导氨基酸调控仔猪小肠黏膜能量利用与损伤修复

Weaning stress leads to the shortage of energy intake and improvement of mucosal energy supply and utilization is the effective method to alleviate weaning stress and fully develop the growth potential of the piglets. The project is conduct to study the differences in utilizations of amino acids as energy substrates in porcine small intestinal epithelial cells and obtain the optimal amino acids model for cell by detecting the mitochondrial respiratory metabolism; investigate the interactive regulation of AMPK and mTORC1 on mitochondrial respiratory and function, energy metabolism, as well as related signaling pathway via stimulating or inhibiting the AMPK or mTOR; study the effects of amino acids model as energy substrates on mitochondrial function, AMPK and mTORC1 signaling pathway using the damage enterocyte model induced by LPS or H2O2; investigate the effects of different energy substrates supply on intestinal morphology, energy metabolism and the signaling pathway of energy sensing in weaning piglets. The results is to clarify the mechanism of interactive effects of AMPK and mTORC1 on energy utilization, optimize the energy substrates supply model and improve the mucosal renewal in small intestine of piglets. The aim is to provide nutritional regulated manners of improving nutritional status, mucosal damage repair and growth potential in early weaned piglets.

断奶应激常常会导致能量摄入量不能满足其需要量，改善黏膜细胞能量供应和利用，是缓解仔猪断奶应激、充分发挥生长潜力的有效手段。本项目拟采用细胞线粒体呼吸代谢检测技术，研究猪小肠上皮细胞对氨基酸作为能量底物的差异利用，筛选最佳氨基酸供应模式；通过分别激动或抑制AMPK和mTORC1，研究AMPK和mTORC1交互调控小肠上皮细胞线粒体呼吸代谢、线粒体功能、能量代谢及其相关信号通路的作用；利用LPS或H2O2诱导小肠上皮细胞损伤，研究氨基酸供应模式对应激损伤小肠上皮细胞线粒体功能以及能量感应通路的影响；利用断奶应激模型，研究不同能量底物供应模式对仔猪小肠黏膜形态结构、能量代谢及其感应信号通路的调控作用。以期阐明AMPK和mTORC1交互调控仔猪小肠黏膜能量利用机制，优化小肠黏膜能量底物供应模式，促进断奶仔猪肠道黏膜更新，为缓解能量供应不足、促进肠黏膜损伤修复、发挥生长潜力提供营养调控手段。

断奶应激常常会导致能量摄入量不能满足其需要量，改善黏膜细胞能量供应和利用，是缓解仔猪断奶应激、充分发挥生长潜力的有效手段。AMPK和mTORC1是细胞能量感应的重要分子。项目通过研究不同氨基酸浓度对猪肠上皮细胞呼吸代谢以及mTOR和AMPK信号通路发现，随着氨基酸的浓度升高，细胞呼吸代谢升高， mTOR通路被激活的程度也不断增加，AMPK通路逐渐被抑制。为了研究mTOR通路和AMPK通路交互调控作用，采用Rap抑制mTOR通路的同时，通过Compound C或AICAR抑制或激动AMPK信号通路，结果发现，抑制mTOR和AMPK通路均能显著抑制细胞呼吸代谢，相应代谢物的含量降低，且降低糖酵解作用；抑制AMPK通路可能促进脂质代谢；促进AMPK影响糖酵解作用和三羧酸循环的代谢产物，主要调控mTOR通路上游相关基因。作为小肠黏膜的主要能量来源，谷氨酸、谷氨酰胺和天门冬氨酸在正常情况下可通过补充Krebs循环、下调AMPK通路维持小肠能量稳态；在能量供应不足或应激状态下，AMPK、脂肪酸β氧化和线粒体生物合成途径被激活以满足仔猪肠上皮细胞的高能量需求。结果阐明了AMPK和mTORC1交互调控仔猪小肠黏膜能量利用机制，优化小肠黏膜能量底物供应模式，促进断奶仔猪肠道黏膜更新，为缓解能量供应不足、促进肠黏膜损伤修复、发挥生长潜力提供营养调控手段。项目标注发表SCI收录论文11篇，CSCD收录论文3篇，申请发明专利2项，获湖南省自然科学二等奖1项。培养博士研究生2名（其中1名获博士后创新人才支持计划资助），硕士研究生2名。项目项目负责人入选教育部长江学者奖励计划青年学者、第三批中组部万人计划科技领军人才，获中科院青年创新促进会优秀会员；1名项目参与人员晋升为副研究员。