发掘肠道氨基酸转运相关信号途径，可增强营养素利用调控的靶向性，有效提高机体对日粮氨基酸的吸收效率。色氨酸作为猪的一种主要限制性氨基酸，近年来受到国内外学者的高度关注。血管紧张素转化酶2（ACE2）是新发现的肾素血管紧张素系统中的一个关键酶，可介导机体色氨酸的转运，但ACE2影响仔猪肠道色氨酸转运的具体机制尚不清楚。因此，本项目拟以断奶仔猪和猪小肠上皮细胞系为研究对象，采用体外过表达、基因沉默和PCR array手段，研究ACE2在肠道色氨酸转运中的调节作用；同时，建立猪肠上皮细胞B0AT1阻断模型，利用PCR array及免疫荧光技术研究B0AT1对ACE2表达和色氨酸转运的影响；并通过断奶仔猪色氨酸梯度添加试验，验证ACE2介导的肠道色氨酸转运途径，揭示色氨酸转运相关调节通路，为增强仔猪肠道健康、提高氨基酸利用率提供理论依据和技术支撑。

Investigation of signal pathway about intestinal amino acid transportation and metabolism could enhance the targeting effect of nutritional regulation and improving feed efficiency. Tryptophan is an indispensable amino acid that should be supplied by dietary protein in piglets. ACE2, a newly enzyme, involves the tryptophan transportation in intestine, which the modulation and key signal pathway of this process were not clear. Therefore, the objective of this study will focus on the mechanism and regulation of ACE2 mediated the tryptophan transportation in porcine intestinal epithelium of weaning piglets. PCR array, over expression and gene silence methods will be used for interpretation of the regulation of ACE2 in Trp transportation of IPEC cell lines. PCR array and immunofluorescence will be used for testing the effect of B0AT1 on ACE2 expression and Trp transportation of IPEC. Functional verification of ACE2 regulation in Trp transportation will be preceded by animal feeding experiment. The main implication of this study is to improve the fundamental knowledge about how the ACE2 modulate intestinal Trp transportation in piglets, and provide solid evidence to enhance intestinal amino acid absorption efficiency and improve piglets’ health.