最近研究表明，二肽是调控动物肠道健康的重要营养素。我们前期工作发现，γ-Glu-Leu在动物血液中含量较高，且该二肽能促进小鼠肠道紧密连接蛋白的表达，提示其对肠上皮屏障有调控作用。但γ-Glu-Leu对猪肠上皮屏障功能的影响及机制尚不清楚。本项目首先以Transwell培养的猪小肠上皮细胞为模型，采用TEER、细胞免疫荧光和激光共聚焦等技术，研究γ-Glu-Leu对猪小肠上皮细胞屏障功能的影响。其次，采用转录组、蛋白组、激动剂和阻断剂等技术，揭示γ-Glu-Leu通过PI3K/Akt/mTOR等信号通路调控肠上皮细胞屏障的机制。最后，通过饲养试验，采用尤斯灌流、透射电镜等技术，验证γ-Glu-Leu对断奶仔猪肠上皮屏障功能的影响及机制。研究结果不仅能深入揭示γ-Glu-Leu对断奶仔猪肠上皮屏障功能的调控作用及其机制，同时可为γ-谷氨酰二肽类营养素在调控仔猪肠道健康中的应用提供科学依据。

Recent researches showed that dipeptides are important nutrients on regulating intestinal health of animals. Our previous study found that γ-Glu-Leu appeared a high concentration in animal blood and it could promote the expression of intestinal tight junction protein in mice, suggesting its regulation effect on intestinal epithelial barrier. However, the effect and mechanism of γ-Glu-Leu on porcine intestinal epithelial barrier functions remain unclear. Therefore, in this project, we firstly study the effect of γ-Glu-Leu on barrier function of transwell cultured IPEC-J2 cells with the help of TEER, cellular immunofluorescence and laser confocal microscope techniques. Then we study the mechanism of γ-Glu-Leu on regulating the barrier function of IPEC-J2 cells with the help of techniques such as transcriptomics, proteomics, specific agonists and blockers. Finally, we carry out feeding experiment on weaned piglets to verify the effect of γ-Glu-Leu on porcine intestinal epithelial barrier functions with the help of ussing chamber and transmission electron microscope (TEM). The results are expected to reveal the mechanism of γ-Glu-Leu on intestinal barrier and provide scientific basis for the application of γ-glutamyl dipeptide nutrients on pig farming.