Jiang Qianming, Sherlock Danielle N, Guyader Jessie, Loor Juan J
Department of Animal Sciences, University of Illinois, Urbana, IL 61801, USA.
Evonik Operations GmbH, Hanau-Wolfgang, 63457 Essen, Germany.
Animals (Basel). 2023 Mar 29;13(7):1189. doi: 10.3390/ani13071189.
Data from non-ruminants indicate that amino acid (AA) transport into cells can regulate mTOR pathway activity and protein synthesis. Whether mTOR is expressed in the ruminant gastrointestinal tract (GIT) and how it may be related to AA transporters and the AA concentrations in the tissue is unknown. Ruminal papillae and the epithelia of the duodenum, jejunum, and ileum collected at slaughter from eight clinically healthy Holstein in mid-lactation were used. Metabolites and RNA were extracted from tissue for liquid chromatography-mass spectrometry and RT-qPCR analysis. The glycine and asparagine concentrations in the rumen were greater than those in the intestine ( < 0.05), but the concentrations of other AAs were greater in the small intestine than those in the rumen. Among the 20 AAs identified, the concentrations of glutamate, alanine, and glycine were the greatest. The mRNA abundances of and were greater in the small intestine than those in the rumen ( < 0.05). Similarly, the , , , , , and mRNA abundances were greater ( < 0.05) in the small intestine than those in the rumen. The mRNA abundances of , and were greater in the rumen than those in the small intestine ( < 0.05). Overall, the present study provides fundamental data on the relationship between mTOR pathway components and the transport of AAs in different sections of the gastrointestinal tract.
来自非反刍动物的数据表明，氨基酸（AA）转运进入细胞可调节mTOR信号通路活性和蛋白质合成。mTOR是否在反刍动物胃肠道（GIT）中表达，以及它与AA转运体和组织中AA浓度之间可能存在怎样的关系尚不清楚。本研究使用了8头处于泌乳中期的临床健康荷斯坦奶牛屠宰时采集的瘤胃乳头以及十二指肠、空肠和回肠的上皮组织。从组织中提取代谢物和RNA用于液相色谱 - 质谱分析和RT - qPCR分析。瘤胃中的甘氨酸和天冬酰胺浓度高于肠道中的浓度（P < 0.05），但其他AA在小肠中的浓度高于瘤胃中的浓度。在所鉴定的20种AA中，谷氨酸、丙氨酸和甘氨酸的浓度最高。小肠中SLC1A1和SLC7A8的mRNA丰度高于瘤胃中的丰度（P < 0.05）。同样，小肠中SLC3A2、SLC7A7、SLC7A9、SLC7A10、SLC7A6和SLC1A5的mRNA丰度也高于瘤胃中的丰度（P < 0.05）。瘤胃中SLC6A14、SLC3A1和SLC7A2的mRNA丰度高于小肠中的丰度（P < 0.05）。总体而言，本研究提供了关于mTOR信号通路成分与胃肠道不同部位AA转运之间关系的基础数据。
