Tryptophan metabolism in health and disease

• Published in: Cell metabolism 2023-08, Vol.35 (8), p.1304-1326
• Main Authors: Xue, Chen, Li, Ganglei, Zheng, Qiuxian, Gu, Xinyu, Shi, Qingmiao, Su, Yuanshuai, Chu, Qingfei, Yuan, Xin, Bao, Zhengyi, Lu, Juan, Li, Lanjuan
• Format: Article
• Language: English
• Subjects: cancer; clinical feature; immune response; targeted therapies; tryptophan metabolism
• ISSN: 1550-4131; 1932-7420
• DOI: 10.1016/j.cmet.2023.06.004

Tryptophan (Trp) metabolism primarily involves the kynurenine, 5-hydroxytryptamine, and indole pathways. A variety of bioactive compounds produced via Trp metabolism can regulate various physiological functions, including inflammation, metabolism, immune responses, and neurological function. Emerging evidence supports an intimate relationship between Trp metabolism disorder and diseases. The levels or ratios of Trp metabolites are significantly associated with many clinical features. Additionally, studies have shown that disease progression can be controlled by modulating Trp metabolism. Indoleamine-2,3-dioxygenase, Trp-2,3-dioxygenase, kynurenine-3-monooxygenase, and Trp hydroxylase are the rate-limiting enzymes that are critical for Trp metabolism. These key regulatory enzymes can be targeted for treating several diseases, including tumors. These findings provide novel insights into the treatment of diseases. In this review, we have summarized the recent research progress on the role of Trp metabolites in health and disease along with their clinical applications. Xue et al. concentrate on the roles and underlying mechanisms of Trp metabolism in health and disease. In addition, the clinical applications of Trp metabolism inhibitors are discussed. Xue et al. provide ideas for targeting Trp metabolism as a potentially advantageous therapeutic strategy for treating diseases.