An Emerging Cross-Species Marker for Organismal Health: Tryptophan-Kynurenine Pathway
Tryptophan (TRP) is an essential dietary amino acid that, unless otherwise committed to protein synthesis, undergoes metabolism via the Tryptophan-Kynurenine (TRP-KYN) pathway in vertebrate organisms. TRP and its metabolites have key roles in diverse physiological processes including cell growth and...
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| Format: | Article |
| Language: | English |
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MDPI AG
2022-06-01
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| Series: | International Journal of Molecular Sciences |
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| Online Access: | https://www.mdpi.com/1422-0067/23/11/6300 |
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| author | Laiba Jamshed Amrita Debnath Shanza Jamshed Jade V. Wish Jason C. Raine Gregg T. Tomy Philippe J. Thomas Alison C. Holloway |
| author_facet | Laiba Jamshed Amrita Debnath Shanza Jamshed Jade V. Wish Jason C. Raine Gregg T. Tomy Philippe J. Thomas Alison C. Holloway |
| author_sort | Laiba Jamshed |
| collection | DOAJ |
| description | Tryptophan (TRP) is an essential dietary amino acid that, unless otherwise committed to protein synthesis, undergoes metabolism via the Tryptophan-Kynurenine (TRP-KYN) pathway in vertebrate organisms. TRP and its metabolites have key roles in diverse physiological processes including cell growth and maintenance, immunity, disease states and the coordination of adaptive responses to environmental and dietary cues. Changes in TRP metabolism can alter the availability of TRP for protein and serotonin biosynthesis as well as alter levels of the immune-active KYN pathway metabolites. There is now considerable evidence which has shown that the TRP-KYN pathway can be influenced by various stressors including glucocorticoids (marker of chronic stress), infection, inflammation and oxidative stress, and environmental toxicants. While there is little known regarding the role of TRP metabolism following exposure to environmental contaminants, there is evidence of linkages between chemically induced metabolic perturbations and altered TRP enzymes and KYN metabolites. Moreover, the TRP-KYN pathway is conserved across vertebrate species and can be influenced by exposure to xenobiotics, therefore, understanding how this pathway is regulated may have broader implications for environmental and wildlife toxicology. The goal of this narrative review is to (1) identify key pathways affecting Trp-Kyn metabolism in vertebrates and (2) highlight consequences of altered tryptophan metabolism in mammals, birds, amphibians, and fish. We discuss current literature available across species, highlight gaps in the current state of knowledge, and further postulate that the kynurenine to tryptophan ratio can be used as a novel biomarker for assessing organismal and, more broadly, ecosystem health. |
| first_indexed | 2024-03-10T01:13:35Z |
| format | Article |
| id | doaj.art-d3236699751f46f1994ffe6cc9364c5c |
| institution | Directory Open Access Journal |
| issn | 1661-6596 1422-0067 |
| language | English |
| last_indexed | 2024-03-10T01:13:35Z |
| publishDate | 2022-06-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | International Journal of Molecular Sciences |
| spelling | doaj.art-d3236699751f46f1994ffe6cc9364c5c2023-11-23T14:13:10ZengMDPI AGInternational Journal of Molecular Sciences1661-65961422-00672022-06-012311630010.3390/ijms23116300An Emerging Cross-Species Marker for Organismal Health: Tryptophan-Kynurenine PathwayLaiba Jamshed0Amrita Debnath1Shanza Jamshed2Jade V. Wish3Jason C. Raine4Gregg T. Tomy5Philippe J. Thomas6Alison C. Holloway7Department of Obstetrics and Gynecology, McMaster University, Hamilton, ON L8S 4K1, CanadaDepartment of Obstetrics and Gynecology, McMaster University, Hamilton, ON L8S 4K1, CanadaDepartment of Obstetrics and Gynecology, McMaster University, Hamilton, ON L8S 4K1, CanadaDepartment of Chemistry, Centre for Oil and Gas Research and Development (COGRAD), University of Manitoba, 586 Parker Building, 144 Dysart Rd., Winnipeg, MB R3T 2N2, CanadaQuesnel River Research Centre, University of Northern British Columbia, Prince George, BC V2N 4Z9, CanadaDepartment of Chemistry, Centre for Oil and Gas Research and Development (COGRAD), University of Manitoba, 586 Parker Building, 144 Dysart Rd., Winnipeg, MB R3T 2N2, CanadaEnvironment and Climate Change Canada, National Wildlife Research Centre, Ottawa, ON K1A 0H3, CanadaDepartment of Obstetrics and Gynecology, McMaster University, Hamilton, ON L8S 4K1, CanadaTryptophan (TRP) is an essential dietary amino acid that, unless otherwise committed to protein synthesis, undergoes metabolism via the Tryptophan-Kynurenine (TRP-KYN) pathway in vertebrate organisms. TRP and its metabolites have key roles in diverse physiological processes including cell growth and maintenance, immunity, disease states and the coordination of adaptive responses to environmental and dietary cues. Changes in TRP metabolism can alter the availability of TRP for protein and serotonin biosynthesis as well as alter levels of the immune-active KYN pathway metabolites. There is now considerable evidence which has shown that the TRP-KYN pathway can be influenced by various stressors including glucocorticoids (marker of chronic stress), infection, inflammation and oxidative stress, and environmental toxicants. While there is little known regarding the role of TRP metabolism following exposure to environmental contaminants, there is evidence of linkages between chemically induced metabolic perturbations and altered TRP enzymes and KYN metabolites. Moreover, the TRP-KYN pathway is conserved across vertebrate species and can be influenced by exposure to xenobiotics, therefore, understanding how this pathway is regulated may have broader implications for environmental and wildlife toxicology. The goal of this narrative review is to (1) identify key pathways affecting Trp-Kyn metabolism in vertebrates and (2) highlight consequences of altered tryptophan metabolism in mammals, birds, amphibians, and fish. We discuss current literature available across species, highlight gaps in the current state of knowledge, and further postulate that the kynurenine to tryptophan ratio can be used as a novel biomarker for assessing organismal and, more broadly, ecosystem health.https://www.mdpi.com/1422-0067/23/11/6300tryptophankynureninemetabolitesglucocorticoidsstressinflammation |
| spellingShingle | Laiba Jamshed Amrita Debnath Shanza Jamshed Jade V. Wish Jason C. Raine Gregg T. Tomy Philippe J. Thomas Alison C. Holloway An Emerging Cross-Species Marker for Organismal Health: Tryptophan-Kynurenine Pathway International Journal of Molecular Sciences tryptophan kynurenine metabolites glucocorticoids stress inflammation |
| title | An Emerging Cross-Species Marker for Organismal Health: Tryptophan-Kynurenine Pathway |
| title_full | An Emerging Cross-Species Marker for Organismal Health: Tryptophan-Kynurenine Pathway |
| title_fullStr | An Emerging Cross-Species Marker for Organismal Health: Tryptophan-Kynurenine Pathway |
| title_full_unstemmed | An Emerging Cross-Species Marker for Organismal Health: Tryptophan-Kynurenine Pathway |
| title_short | An Emerging Cross-Species Marker for Organismal Health: Tryptophan-Kynurenine Pathway |
| title_sort | emerging cross species marker for organismal health tryptophan kynurenine pathway |
| topic | tryptophan kynurenine metabolites glucocorticoids stress inflammation |
| url | https://www.mdpi.com/1422-0067/23/11/6300 |
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