New Insights into Tryptophan Metabolism
A special issue of International Journal of Molecular Sciences (ISSN 1422-0067). This special issue belongs to the section "Molecular Endocrinology and Metabolism".
Deadline for manuscript submissions: 25 December 2025 | Viewed by 43
Special Issue Editor
Interests: bile acids; serotonin; serotonin receptor; Tph1; Tph2; tryptophan; tryptophan metabolites; GLP-1; GLP-1 receptor agonists; GIP; FGF21; FGF15/19; neuropeptides; gut-derived hormones; liv-er-derived hormones; obesity; diabetes; appetite; food intake; hypothalamus; energy homeosta-sis; hepatosteatosis; glucose metabolism; lipid metabolism; organ network; whey protein; soy protein; insulin, leptin, insulin resistance; adipose tissue; CNS; gene expression; sympathetic nervous system
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Special Issue Information
Dear Colleagues,
Tryptophan (Trp) is an essential amino acid that cannot be synthesized in the body and must be obtained via one's diet. In the body, Trp can be converted to serotonin (5-HT), kynurenine (Kyn), and indole-3-propionic acid (IPA). Trp and its metabolites are involved in health and a variety of diseases, including mental disorders, metabolic diseases, neurologic diseases, cardiovascular diseases, gastrointestinal diseases, immune diseases, and cancer.
Indoleamine-2,3 dioxygenase 1 (IDO1) is the enzyme responsible for converting Trp to Kyn. Tryptophan hydroxylase (Tph) is the enzyme responsible for converting Trp into 5-HT. Since the discovery of the two types of Tph (Tph1 and Tph2), it has become widely accepted that the central and peripheral 5-HT systems are functionally separate. Tph2 biosynthesizes 5-HT centrally, and Tph1 does so peripherally. A novel regulation of Trp and its metabolites, however, has recently been discovered: Tph1 can regulate Trp and its metabolites outside 5-HT in the plasma and brain.
In this Special Issue, we will explore novel regulatory mechanisms of Trp metabolism, novel functions of the rate-limiting enzymes for converting tryptophan, and the role of tryptophan metabolism in health and diseases. Any types of papers, including reviews, original papers, communications, and brief reports, are welcome.
Prof. Dr. Katsunori Nonogaki
Guest Editor
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Keywords
- tryptophan
- serotonin
- kynurenine
- indole
- metabolism
- IPA
- Tph
- IDO1
- health
- disease
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