肠三叶因子(ITF)是肠道重要的保护分子，在维护烧伤后肠粘膜屏障中发挥重要作用。前期研究发现，谷氨酰胺(Gln)可通过促进谷胱甘肽(GSH)合成，维持蛋白质二硫键异构酶(PDI)活性，促进对ITF的修饰，但机制不明。鉴于NADPH是GSH生成的关键分子，而6磷酸葡萄糖脱氢酶(G6PD)和谷胱甘肽还原酶(GR)是NADPH合成与利用的关键酶。从而提出Gln可能通过调控G6PD和GR促进NADPH合成，维持PDI活性，促进ITF修饰的假说。为此，拟采用定点突变、基因剪辑、敲除等手段抑制GLS、G6PD和GR，观察Gln对PDI活性及ITF修饰的影响。进而采用代谢流分析、酶动力学等手段，分析NADPH产生的代谢通路。最后通过调控Gln代谢，观察其对NADPH合成、PDI功能、ITF修饰及受损肠粘膜修复的影响。本研究有望初步阐明Gln维护PDI活性，促进ITF修饰的代谢机制，具有重要的理论意义。

Intestinal trefoil factor (ITF) is an important protective molecular of intestine, which plays a pivotal role in maintaining intestinal mucosa barrier after burn. Our previous studies have found that glutamine (Gln) can maintain protein disulfide isomerase (PDI) activity and promote ITF modification by promoting glutathione (GSH) synthesis. However, the mechanism is unclear. In view of NADPH is the key molecule of  glutathione(GSH) generation, while glucose 6 phosphate dehydrogenase (G6PD) and glutathione reductase (GR) are the key enzyme of NADPH synthesis and utilization. Thereby, we put forward the hypothesis that Gln may improve PDI activity and promote ITF modification by regulating G6PD and GR to promote NADPH synthesis. To this end, we plan to adopt site-directed mutagenesis, gene editing and gene knockout to inhibit GLS, G6PD and GR activity and observe the effects of the PDI activity on ITF modification. And then, using metabolic flux analysis and enzyme kinetics to analyze metabolic pathway produced by NADPH. Finally, observing the effects of regulating Gln metabolism on NADPH synthesis, PDI function, ITF modification and damaged intestinal mucosa repair. The research is expected to preliminarily clarify the metabolic mechanism of Gln maintaining PDI activity and promoting ITF modification, which has important theoretical significance.