Article
Environmental Sciences
Jade Wish, Patrique Bulloch, Lisa Oswald, Thor Halldorson, Jason C. Raine, Laiba Jamshed, Chris Marvin, Philippe J. Thomas, Alison C. Holloway, Gregg T. Tomy
Summary: This study aimed to determine the KYN to TRP ratio as a biomarker of acute stress in fish, and found that the KTR in fish liver and brain significantly increased at 48 hours post-stress exposure. Additionally, cortisol responded more quickly to the stress stimulus compared to KYN and TRP in fish tissues.
Article
Chemistry, Analytical
Skaidre Jankovskaja, Maxim Morin, Anna Gustafsson, Chris D. Anderson, Boglarka Lehoczki, Johan Engblom, Sebastian Bjorklund, Meinda Rezeli, Gyorgy Marko-Varga, Tautgirdas Ruzgas
Summary: This study assessed various sampling approaches for tryptophan and kynurenine and found that the phenylalanine/tryptophan ratio may be a possible alternative biomarker for non-invasive skin cancer detection.
ANALYTICAL CHEMISTRY
(2022)
Article
Biochemistry & Molecular Biology
Harald Mangge, Markus Herrmann, Andreas Meinitzer, Sabine Pailer, Pero Curcic, Zdenka Sloup, Magdalena Holter, Florian Prueller
Summary: Kynurenine is a promising blood biomarker for predicting mortality risk in severe COVID-19 cases, with KYN levels at the time of SARS-CoV-2 diagnosis serving as an early indicator of poor outcomes. Age, KYN, ferritin, and other markers were found to significantly impact survival time, underscoring the potential of Kynurenine as a prognostic tool in COVID-19 management.
Article
Multidisciplinary Sciences
Skaidre Jankovskaja, Johan Engblom, Melinda Rezeli, Gyorgy Marko-Varga, Tautgirdas Ruzgas, Sebastian Bjorklund
Summary: The tryptophan to kynurenine ratio has been proposed as a cancer biomarker and can be sampled non-invasively on the skin. Studies have shown that the permeability of Trp and Kyn is feasible, with factors like pH variations and sampling time affecting the results. The experimental results are supported by a four-permeation pathways model, suggesting different permeation pathways for the molecules.
SCIENTIFIC REPORTS
(2021)
Article
Medicine, General & Internal
Hani Oweira, Imad Lahdou, Stefan Mehrle, Elias Khajeh, Rajan Nikbakhsh, Omid Ghamarnejad, Peter Terness, Christoph Reissfelder, Mahmoud Sadeghi, Ali Ramouz
Summary: The study revealed that TDO and IDO enzymes have different effects in the conversion of Trp and Kyn in human liver cells and liver cancer cells. Activating the IDO enzyme does not significantly affect Trp degradation and Kyn accumulation, while inhibiting the TDO enzyme significantly reduces Trp degradation.
JOURNAL OF CLINICAL MEDICINE
(2022)
Article
Immunology
Duygu Eryavuz Onmaz, Abdullah Sivrikaya, Kevser Isik, Sedat Abusoglu, Ilknur Albayrak Gezer, Fatma Humeyra Yerlikaya, Gulsum Abusoglu, Ali Unlu, Dilek Tezcan
Summary: The study found altered kynurenine pathway metabolism in AS patients. Conventional therapy and anti-TNF-alpha therapy are effective in reducing the Kynurenine/Tryptophan ratio and CRP levels.
INTERNATIONAL IMMUNOPHARMACOLOGY
(2021)
Article
Urology & Nephrology
Sze Han Lee, Ratha Mahendran, Sin Mun Tham, Thomas Paulraj Thamboo, Billy Jianhao Chionh, Yi Xin Lim, Woon Chau Tsang, Qing Hui Wu, Jun Yang Chia, Melissa Hui Wen Tay, Benjamin Yen Seow Goh, Kelven Weijing Chen, Jeane Zepeda Mallari, Revathi Periaswami, Lata Raman, Shoa Nian Choo, Dorinda Yan Qin Kioh, Edmund Chiong, Kesavan Esuvaranathan, Eric Chun Yong Chan
Summary: The study revealed that plasma tryptophan levels were significantly decreased in bladder cancer patients, while both plasma and urinary KYN-TRP ratios were increased. Furthermore, the expression of IDO1 was found to be elevated in human bladder tumors. In the murine model, a positive correlation was reported between IDO1 expression, KYN-TRP ratio, normalized PSA to creatinine, and bladder tumor burden.
Article
Multidisciplinary Sciences
La-or Chailurkit, Suwannee Chanprasertyothin, Nisakron Thongmung, Piyamitr Sritara, Boonsong Ongphiphadhanakul
Summary: The present study suggests that the FTO gene may influence the conversion of tryptophan to kynurenine. These findings may contribute to a better understanding of the mechanisms underlying the action of the FTO gene in obesity.
Review
Immunology
Arduino A. Mangoni, Angelo Zinellu
Summary: There is a growing interest in the role of the kynurenine pathway in regulating immune function and inflammation in rheumatic diseases (RD). This study conducted a systematic review and meta-analysis to explore the link between this pathway and RD by examining the levels of tryptophan, kynurenine, and other relevant metabolites in RD patients and healthy controls. The analysis of selected studies revealed significantly lower tryptophan levels and higher kynurenine levels, kynurenine to tryptophan ratios, 3-hydroxykynurenine levels, and quinolinic acid concentrations in RD patients compared to controls. However, the levels of kynurenic acid, 3-hydroxyanthranilic acid, kynurenic acid to kynurenine ratio, and quinolinic acid to kynurenine acid ratio did not show significant differences. Subgroup analysis showed consistent results across different types of RD, except for rheumatoid arthritis. Further research is needed to determine the potential diagnostic and management utility of these biomarkers in RD patients.
FRONTIERS IN IMMUNOLOGY
(2023)
Review
Biochemistry & Molecular Biology
Laiba Jamshed, Amrita Debnath, Shanza Jamshed, Jade Wish, Jason C. Raine, Gregg T. Tomy, Philippe J. Thomas, Alison C. Holloway
Summary: Tryptophan metabolism plays a critical role in various physiological processes and can be influenced by environmental factors and chemical contaminants. Understanding this pathway may have broader implications for the health of organisms and ecosystems.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2022)
Article
Chemistry, Multidisciplinary
Jinni Zhao, Xilong Leng, Jiazhao Lin, Xiaoping Yang, Xiaoli Lv, Xianfeng Huang, Zhi Yang, Desmond Schipper
Summary: A high-nuclearity Zn(ii)-Eu(iii) nanocluster was synthesized for fast and accurate luminescence detection of neopterin, an inflammatory marker.
CHEMICAL COMMUNICATIONS
(2023)
Review
Pharmacology & Pharmacy
Marta Marszalek-Grabska, Katarzyna Walczak, Kinga Gawel, Katarzyna Wicha-Komsta, Sylwia Wnorowska, Artur Wnorowski, Waldemar A. Turski
Summary: KYN, a main metabolite of tryptophan produced mainly in the liver by TDO under physiological conditions, is also synthesized by IDO in diseases. While KYN's role in central nervous system pathologies is well studied, its functions in the periphery are less explored.
PHARMACOLOGY & THERAPEUTICS
(2021)
Article
Medical Laboratory Technology
Simon Michaelis, Sieglinde Zelzer, Wolfgang J. Schnedl, Andreas Baranyi, Andreas Meinitzer, Dietmar Enko
Summary: Measuring the concentrations of tryptophan and kynurenine upon admission, as well as calculating the KYN/TRP ratio, can predict the survival outcome of patients with SARS-CoV-2.
CLINICA CHIMICA ACTA
(2022)
Article
Cardiac & Cardiovascular Systems
Nada Joe Melhem, Mouna Chajadine, Ingrid Gomez, Kiave-Yune Howangyin, Marion Bouvet, Camille Knosp, Yanyi Sun, Marie Rouanet, Ludivine Laurans, Olivier Cazorla, Mathilde Lemitre, Jose Vilar, Ziad Mallat, Alain Tedgui, Hafid Ait-Oufella, Jean-Sebastien Hulot, Jacques Callebert, Jean-Marie Launay, Jeremy Fauconnier, Jean-Sebastien Silvestre, Soraya Taleb
Summary: The study suggests that IDO could be a potential therapeutic target in acute myocardial infarction, as its deficiency limits cardiac injury and dysfunction after MI, with endothelial cell-specific deletion of IDO showing improvement in cardiac function and reduction in adverse ventricular remodeling.
Article
Psychiatry
Matthias Michal, Andreas Schulz, Philipp S. Wild, Thomas Koeck, Thomas Muenzel, Alexander K. Schuster, Konstantin Strauch, Karl Lackner, Sigurd D. Suessmuth, Heiko G. Niessen, Andreas Borta, Kelly A. Allers, Daniela Zahn, Manfred E. Beutel
Summary: Previous studies have shown altered tryptophan catabolite concentrations in major depression, suggesting their potential as biomarkers and treatment targets. However, these studies had small sample sizes, limiting their generalizability. In this population-based study with 3,389 participants, we found that clinically significant depression was associated with lower levels of kynurenine and kynurenic acid. However, the correlation between tryptophan catabolites and depression severity was very small, and they could not be used to diagnose depression.