1
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Gabrawy MM, Westbrook R, King A, Khosravian N, Ochaney N, DeCarvalho T, Wang Q, Yu Y, Huang Q, Said A, Abadir M, Zhang C, Khare P, Fairman JE, Le A, Milne GL, Vonhoff FJ, Walston JD, Abadir PM. Dual treatment with kynurenine pathway inhibitors and NAD + precursors synergistically extends life span in Drosophila. Aging Cell 2024; 23:e14102. [PMID: 38481042 PMCID: PMC11019140 DOI: 10.1111/acel.14102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Revised: 01/19/2024] [Accepted: 01/24/2024] [Indexed: 04/17/2024] Open
Abstract
Tryptophan catabolism is highly conserved and generates important bioactive metabolites, including kynurenines, and in some animals, NAD+. Aging and inflammation are associated with increased levels of kynurenine pathway (KP) metabolites and depleted NAD+, factors which are implicated as contributors to frailty and morbidity. Contrastingly, KP suppression and NAD+ supplementation are associated with increased life span in some animals. Here, we used DGRP_229 Drosophila to elucidate the effects of KP elevation, KP suppression, and NAD+ supplementation on physical performance and survivorship. Flies were chronically fed kynurenines, KP inhibitors, NAD+ precursors, or a combination of KP inhibitors with NAD+ precursors. Flies with elevated kynurenines had reduced climbing speed, endurance, and life span. Treatment with a combination of KP inhibitors and NAD+ precursors preserved physical function and synergistically increased maximum life span. We conclude that KP flux can regulate health span and life span in Drosophila and that targeting KP and NAD+ metabolism can synergistically increase life span.
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Affiliation(s)
- Mariann M. Gabrawy
- School of Medicine, Division of Geriatric Medicine and Gerontology, Biology of Healthy Aging ProgramJohns Hopkins UniversityBaltimoreMarylandUSA
| | - Reyhan Westbrook
- School of Medicine, Division of Geriatric Medicine and Gerontology, Biology of Healthy Aging ProgramJohns Hopkins UniversityBaltimoreMarylandUSA
| | - Austin King
- School of Medicine, Division of Geriatric Medicine and Gerontology, Biology of Healthy Aging ProgramJohns Hopkins UniversityBaltimoreMarylandUSA
- Department of Biological SciencesUniversity of Maryland, Baltimore CountyBaltimoreMarylandUSA
| | - Nick Khosravian
- School of Medicine, Division of Geriatric Medicine and Gerontology, Biology of Healthy Aging ProgramJohns Hopkins UniversityBaltimoreMarylandUSA
- Department of Biological SciencesUniversity of Maryland, Baltimore CountyBaltimoreMarylandUSA
| | - Neeraj Ochaney
- School of Medicine, Division of Geriatric Medicine and Gerontology, Biology of Healthy Aging ProgramJohns Hopkins UniversityBaltimoreMarylandUSA
- Department of Biological SciencesUniversity of Maryland, Baltimore CountyBaltimoreMarylandUSA
| | - Tagide DeCarvalho
- Department of Biological SciencesUniversity of Maryland, Baltimore CountyBaltimoreMarylandUSA
| | - Qinchuan Wang
- School of Medicine, Division of Geriatric Medicine and Gerontology, Biology of Healthy Aging ProgramJohns Hopkins UniversityBaltimoreMarylandUSA
| | - Yuqiong Yu
- School of Medicine, Division of Geriatric Medicine and Gerontology, Biology of Healthy Aging ProgramJohns Hopkins UniversityBaltimoreMarylandUSA
| | - Qiao Huang
- School of Medicine, Division of Geriatric Medicine and Gerontology, Biology of Healthy Aging ProgramJohns Hopkins UniversityBaltimoreMarylandUSA
| | - Adam Said
- School of Medicine, Division of Geriatric Medicine and Gerontology, Biology of Healthy Aging ProgramJohns Hopkins UniversityBaltimoreMarylandUSA
- Emory UniversityAtlantaGeorgiaUSA
| | - Michael Abadir
- School of Medicine, Division of Geriatric Medicine and Gerontology, Biology of Healthy Aging ProgramJohns Hopkins UniversityBaltimoreMarylandUSA
- University of Maryland, College ParkCollege ParkMarylandUSA
| | | | | | - Jennifer E. Fairman
- Department of Arts as Applied to MedicineJohns Hopkins UniversityBaltimoreMarylandUSA
| | - Anne Le
- Gigantest Inc.BaltimoreMarylandUSA
| | - Ginger L. Milne
- Vanderbilt UniversityVanderbilt Brain Institute, Neurochemistry CoreNashvilleTennesseeUSA
| | - Fernando J. Vonhoff
- Department of Biological SciencesUniversity of Maryland, Baltimore CountyBaltimoreMarylandUSA
| | - Jeremy D. Walston
- School of Medicine, Division of Geriatric Medicine and Gerontology, Biology of Healthy Aging ProgramJohns Hopkins UniversityBaltimoreMarylandUSA
| | - Peter M. Abadir
- School of Medicine, Division of Geriatric Medicine and Gerontology, Biology of Healthy Aging ProgramJohns Hopkins UniversityBaltimoreMarylandUSA
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2
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Hayes AJ, Zheng X, O'Kelly J, Neyton LPA, Bochkina NA, Uings I, Liddle J, Baillie JK, Just G, Binnie M, Homer NZM, Murray TBJ, Baily J, McGuire K, Skouras C, Garden OJ, Webster SP, Iredale JP, Howie SEM, Mole DJ. Kynurenine monooxygenase regulates inflammation during critical illness and recovery in experimental acute pancreatitis. Cell Rep 2023; 42:112763. [PMID: 37478012 DOI: 10.1016/j.celrep.2023.112763] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Revised: 12/14/2022] [Accepted: 06/21/2023] [Indexed: 07/23/2023] Open
Abstract
Kynurenine monooxygenase (KMO) blockade protects against multiple organ failure caused by acute pancreatitis (AP), but the link between KMO and systemic inflammation has eluded discovery until now. Here, we show that the KMO product 3-hydroxykynurenine primes innate immune signaling to exacerbate systemic inflammation during experimental AP. We find a tissue-specific role for KMO, where mice lacking Kmo solely in hepatocytes have elevated plasma 3-hydroxykynurenine levels that prime inflammatory gene transcription. 3-Hydroxykynurenine synergizes with interleukin-1β to cause cellular apoptosis. Critically, mice with elevated 3-hydroxykynurenine succumb fatally earlier and more readily to experimental AP. Therapeutically, blockade with the highly selective KMO inhibitor GSK898 rescues the phenotype, reducing 3-hydroxykynurenine and protecting against critical illness and death. Together, our findings establish KMO and 3-hydroxykynurenine as regulators of inflammation and the innate immune response to sterile inflammation. During critical illness, excess morbidity and death from multiple organ failure can be rescued by systemic KMO blockade.
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Affiliation(s)
- Alastair J Hayes
- University of Edinburgh Centre for Inflammation Research, Institute for Regeneration and Repair, University of Edinburgh, Edinburgh, UK; Clinical Surgery, University of Edinburgh, Edinburgh, UK
| | - Xiaozhong Zheng
- University of Edinburgh Centre for Inflammation Research, Institute for Regeneration and Repair, University of Edinburgh, Edinburgh, UK
| | - James O'Kelly
- University of Edinburgh Centre for Inflammation Research, Institute for Regeneration and Repair, University of Edinburgh, Edinburgh, UK; Clinical Surgery, University of Edinburgh, Edinburgh, UK
| | - Lucile P A Neyton
- University of Edinburgh Centre for Inflammation Research, Institute for Regeneration and Repair, University of Edinburgh, Edinburgh, UK; The Roslin Institute, University of Edinburgh, Edinburgh, UK
| | - Natalia A Bochkina
- School of Mathematics and Maxwell Institute, University of Edinburgh, Edinburgh, UK
| | - Iain Uings
- GlaxoSmithKline, Gunnels Wood Road, Stevenage, Hertfordshire, UK
| | - John Liddle
- GlaxoSmithKline, Gunnels Wood Road, Stevenage, Hertfordshire, UK
| | | | - George Just
- Mass Spectrometry Core, Edinburgh Clinical Research Facility, University of Edinburgh, Edinburgh, UK
| | - Margaret Binnie
- Mass Spectrometry Core, Edinburgh Clinical Research Facility, University of Edinburgh, Edinburgh, UK
| | - Natalie Z M Homer
- Mass Spectrometry Core, Edinburgh Clinical Research Facility, University of Edinburgh, Edinburgh, UK
| | | | - James Baily
- Charles River Laboratories, East Lothian, UK
| | - Kris McGuire
- University of Edinburgh Centre for Inflammation Research, Institute for Regeneration and Repair, University of Edinburgh, Edinburgh, UK
| | | | - O James Garden
- Clinical Surgery, University of Edinburgh, Edinburgh, UK
| | - Scott P Webster
- Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, UK
| | | | - Sarah E M Howie
- University of Edinburgh Centre for Inflammation Research, Institute for Regeneration and Repair, University of Edinburgh, Edinburgh, UK
| | - Damian J Mole
- University of Edinburgh Centre for Inflammation Research, Institute for Regeneration and Repair, University of Edinburgh, Edinburgh, UK; Clinical Surgery, University of Edinburgh, Edinburgh, UK.
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3
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Buchanan JL, Rauckhorst AJ, Taylor EB. 3-hydroxykynurenine is a ROS-inducing cytotoxic tryptophan metabolite that disrupts the TCA cycle. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.10.548411. [PMID: 37502990 PMCID: PMC10369892 DOI: 10.1101/2023.07.10.548411] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/29/2023]
Abstract
Tryptophan is an essential amino acid that is extensively characterized as a regulator of cellular function through its metabolism by indoleamine 2,3-deoxygenase (IDO) into the kynurenine pathway. However, despite decades of research on tryptophan metabolism, the metabolic regulatory roles of it and its metabolites are not well understood. To address this, we performed an activity metabolomics screen of tryptophan and most of its known metabolites in cell culture. We discovered that treatment of human colon cancer cells (HCT116) with 3-hydroxykynurenine (3-HK), a metabolite of kynurenine, potently disrupted TCA cycle function. Citrate and aconitate levels were increased, while isocitrate and all downstream TCA metabolites were decreased, suggesting decreased aconitase function. We hypothesized that 3HK or one of its metabolites increased reactive oxygen species (ROS) and inhibited aconitase activity. Accordingly, we observed almost complete depletion of reduced glutathione and a decrease in total glutathione levels. We observed a dose-dependent decrease in cell viability after 48 hours of 3HK treatment. These data suggest that raising the intracellular levels of 3HK could be sufficient to induce ROS-mediated apoptosis. We modulated the intracellular levels of 3HK by combined induction of IDO and knockdown of kynureninase (KYNU) in HCT116 cells. Cell viability decreased significantly after 48 hours of KYNU knockdown compared to controls, which was accompanied by increased ROS production and Annexin V staining revealing apoptosis. Finally, we identify xanthommatin production from 3-HK as a candidate radical-producing, cytotoxic mechanism. Our work indicates that KYNU may be a target for disrupting tryptophan metabolism. Interestingly, many cancers exhibit overexpression of IDO, providing a cancer-specific metabolic vulnerability that could be exploited by KYNU inhibition.
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Affiliation(s)
- Jane L. Buchanan
- Department of Molecular Physiology and Biophysics, University of Iowa Carver College of Medicine, Iowa City, IA 52240, USA
| | - Adam J. Rauckhorst
- Department of Molecular Physiology and Biophysics, University of Iowa Carver College of Medicine, Iowa City, IA 52240, USA
- FOEDRC Metabolomics Core Research Facility, University of Iowa Carver College of Medicine, Iowa City, IA 52240, USA
| | - Eric B. Taylor
- Department of Molecular Physiology and Biophysics, University of Iowa Carver College of Medicine, Iowa City, IA 52240, USA
- Fraternal Order of Eagles Diabetes Research Center (FOEDRC), University of Iowa Carver College of Medicine, Iowa City, IA 52240, USA
- FOEDRC Metabolomics Core Research Facility, University of Iowa Carver College of Medicine, Iowa City, IA 52240, USA
- Holden Comprehensive Cancer Center, University of Iowa Carver College of Medicine, Iowa City, IA 52240, USA
- Abboud Cardiovascular Research Center, University of Iowa Carver College of Medicine, Iowa City, IA 52240, USA
- Pappajohn Biomedical Institute, University of Iowa Carver College of Medicine, Iowa City, IA 52240, USA
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4
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de Oliveira JADP, de Athaide MM, Rahman AU, de Mattos Barbosa MG, Jardim MM, Moraes MO, Pinheiro RO. Kynurenines in the Pathogenesis of Peripheral Neuropathy During Leprosy and COVID-19. Front Cell Infect Microbiol 2022; 12:815738. [PMID: 35281455 PMCID: PMC8907883 DOI: 10.3389/fcimb.2022.815738] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Accepted: 01/27/2022] [Indexed: 11/18/2022] Open
Abstract
Inflammatory disorders are associated with the activation of tryptophan (TRYP) catabolism via the kynurenine pathway (KP). Several reports have demonstrated the role of KP in the immunopathophysiology of both leprosy and coronavirus disease 19 (COVID-19). The nervous system can be affected in infections caused by both Mycobacterium leprae and SARS-CoV-2, but the mechanisms involved in the peripheral neural damage induced by these infectious agents are not fully understood. In recent years KP has received greater attention due the importance of kynurenine metabolites in infectious diseases, immune dysfunction and nervous system disorders. In this review, we discuss how modulation of the KP may aid in controlling the damage to peripheral nerves and the effects of KP activation on neural damage during leprosy or COVID-19 individually and we speculate its role during co-infection.
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Affiliation(s)
| | | | - Atta Ur Rahman
- Leprosy Laboratory, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
| | | | - Marcia Maria Jardim
- Leprosy Laboratory, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
- Department of Neurology, State University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Milton Ozório Moraes
- Leprosy Laboratory, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
| | - Roberta Olmo Pinheiro
- Leprosy Laboratory, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
- *Correspondence: Roberta Olmo Pinheiro,
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5
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The Kynurenine Pathway and Kynurenine 3-Monooxygenase Inhibitors. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27010273. [PMID: 35011505 PMCID: PMC8747024 DOI: 10.3390/molecules27010273] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/30/2021] [Revised: 12/21/2021] [Accepted: 12/22/2021] [Indexed: 12/20/2022]
Abstract
Under normal physiological conditions, the kynurenine pathway (KP) plays a critical role in generating cellular energy and catabolizing tryptophan. Under inflammatory conditions, however, there is an upregulation of the KP enzymes, particularly kynurenine 3-monooxygenase (KMO). KMO has garnered much attention due to its production of toxic metabolites that have been implicated in many diseases and disorders. With many of these illnesses having an inadequate or modest treatment, there exists a need to develop KMO inhibitors that reduce the production of these toxic metabolites. Though prior efforts to find an appropriate KMO inhibitor were unpromising, the development of a KMO crystal structure has provided the opportunity for a rational structure-based design in the development of inhibitors. Therefore, the purpose of this review is to describe the kynurenine pathway, the kynurenine 3-monooxygenase enzyme, and KMO inhibitors and their potential candidacy for clinical use.
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6
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The Kynurenine Pathway as a Potential Target for Neuropathic Pain Therapy Design: From Basic Research to Clinical Perspectives. Int J Mol Sci 2021; 22:ijms222011055. [PMID: 34681715 PMCID: PMC8537209 DOI: 10.3390/ijms222011055] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Revised: 10/08/2021] [Accepted: 10/09/2021] [Indexed: 12/20/2022] Open
Abstract
Accumulating evidence suggests the key role of the kynurenine pathway (KP) of the tryptophan metabolism in the pathogenesis of several diseases. Despite extensive research aimed at clarifying the mechanisms underlying the development and maintenance of neuropathic pain, the roles of KP metabolites in this process are still not fully known. Although the function of the peripheral KP has been known for several years, it has only recently been acknowledged that its metabolites within the central nervous system have remarkable consequences related to physiology and behavior. Both the products and metabolites of the KP are involved in the pathogenesis of pain conditions. Apart from the neuroactive properties of kynurenines, the KP regulates several neurotransmitter systems in direct or indirect ways. Some neuroactive metabolites are known to have neuroprotective properties (kynurenic acid, nicotinamide adenine dinucleotide cofactor), while others are toxic (3-hydroxykynurenine, quinolinic acid). Numerous animal models show that modulation of the KP may turn out to be a viable target for the treatment of diseases. Importantly, some compounds that affect KP enzymes are currently described to possess analgesic properties. Additionally, kynurenine metabolites may be useful for assessing response to therapy or as biomarkers in therapeutic monitoring. The following review describes the molecular site of action and changes in the levels of metabolites of the kynurenine pathway in the pathogenesis of various conditions, with a particular emphasis on their involvement in neuropathy. Moreover, the potential clinical implications of KP modulation in chronic pain therapy as well as the directions of new research initiatives are discussed.
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7
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Sadok I, Tyszczuk-Rotko K, Mroczka R, Kozak J, Staniszewska M. Improved Voltammetric Determination of Kynurenine at the Nafion Covered Glassy Carbon Electrode - Application in Samples Delivered from Human Cancer Cells. Int J Tryptophan Res 2021; 14:11786469211023468. [PMID: 34276216 PMCID: PMC8256253 DOI: 10.1177/11786469211023468] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 05/03/2021] [Indexed: 12/16/2022] Open
Abstract
Nowadays, development of analytical methods responding to a need for rapid and
accurate determination of human metabolites is highly desirable. Herein, an
electrochemical method employing a Nafion-coated glassy carbon electrode
(Nafion/GCE) has been developed for reliable determination of kynurenine (a key
tryptophan metabolite) using a differential pulse adsorptive stripping
voltammetry. To our knowledge, this is the first analytical method to allow for
kynurenine determination at the Nafion-coated electrode. The methodology
involves kynurenine pre-concentration in 0.1 M H2SO4 in
the Nafion film at the potential of +0.5 V and subsequent stripping from the
electrode by differential pulse voltammetry. Under optimal conditions, the
sensor can detect 5 nM kynurenine (for the accumulation time of 60 seconds), but
the limit of detection can be easily lowered to 0.6 nM by prolonging the
accumulation time to 600 seconds. The sensor shows sensitivity of
36.25 μAμM−1cm−2 and
185.50 μAμM−1cm−2 for the accumulation time of 60 and
600 seconds, respectively. The great advantage of the proposed method is easy
sensor preparation, employing drop coating method, high sensitivity, short total
analysis time, and no need for sample preparation. The method was validated for
linearity, precision, accuracy (using a high-performance liquid chromatography),
selectivity (towards tryptophan metabolites and different amino acids), and
recovery. The comprehensive microscopic and electrochemical characterization of
the Nafion/GCE was also conducted with different methods including atomic force
microscopy (AFM), optical profilometry, time-of-flight secondary ion mass
spectrometry (TOF-SIMS), electrochemical impedance spectroscopy (EIS), and
cyclic voltammetry (CV). The method has been applied with satisfactory results
for determination of kynurenine concentration in a culture medium collected from
the human ovarian carcinoma cells SK-OV-3 and to measure IDO enzyme activity in
the cancer cell extracts.
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Affiliation(s)
- Ilona Sadok
- Laboratory of Separation and Spectroscopic Method Applications, Centre for Interdisciplinary Research, Faculty of Science and Health, The John Paul II Catholic University of Lublin, Lublin, Poland
| | - Katarzyna Tyszczuk-Rotko
- Institute of Chemical Sciences, Faculty of Chemistry, Maria Curie-Skłodowska University in Lublin, Lublin, Poland
| | - Robert Mroczka
- Laboratory of X-ray Optics, Centre for Interdisciplinary Research, Faculty of Science and Health, The John Paul II Catholic University of Lublin, Lublin, Poland
| | - Jędrzej Kozak
- Institute of Chemical Sciences, Faculty of Chemistry, Maria Curie-Skłodowska University in Lublin, Lublin, Poland
| | - Magdalena Staniszewska
- Laboratory of Separation and Spectroscopic Method Applications, Centre for Interdisciplinary Research, Faculty of Science and Health, The John Paul II Catholic University of Lublin, Lublin, Poland
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Westbrook R, Chung T, Lovett J, Ward C, Joca H, Yang H, Khadeer M, Tian J, Xue QL, Le A, Ferrucci L, Moaddel R, de Cabo R, Hoke A, Walston J, Abadir PM. Kynurenines link chronic inflammation to functional decline and physical frailty. JCI Insight 2020; 5:136091. [PMID: 32814718 PMCID: PMC7455140 DOI: 10.1172/jci.insight.136091] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Accepted: 07/15/2020] [Indexed: 12/27/2022] Open
Abstract
Chronic inflammation is associated with physical frailty and functional decline in older adults; however, the molecular mechanisms of this linkage are not understood. A mouse model of chronic inflammation showed reduced motor function and partial denervation at the neuromuscular junction. Metabolomic profiling of these mice and further validation in frail human subjects showed significant dysregulation in the tryptophan degradation pathway, including decreased tryptophan and serotonin, and increased levels of some neurotoxic kynurenines. In humans, kynurenine strongly correlated with age, frailty status, TNF-αR1 and IL-6, weaker grip strength, and slower walking speed. To study the effects of elevated neurotoxic kynurenines on motor neuronal cell viability and axonal degeneration, we used motor neuronal cells treated with 3-hydroxykynurenine and quinolinic acid and observed neurite degeneration in a dose-dependent manner and potentiation of toxicity between 3-hydroxykynurenine and quinolinic acid. These results suggest that kynurenines mediate neuromuscular dysfunction associated with chronic inflammation and aging. Tryptophan-related toxic metabolites known as kynurenines are altered with chronic inflammation, which damages nerves in aged and frail mice and humans.
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Affiliation(s)
| | - Tae Chung
- Department of Physical Medicine and Rehabilitation, and.,Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | | | - Chris Ward
- Department of Orthopedics and Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Humberto Joca
- Department of Orthopedics and Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Huanle Yang
- Division of Geriatric Medicine and Gerontology
| | | | - Jing Tian
- Division of Geriatric Medicine and Gerontology
| | - Qian-Li Xue
- Division of Geriatric Medicine and Gerontology
| | - Anne Le
- Department of Oncology and.,Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Luigi Ferrucci
- National Institute on Aging, NIH, Baltimore, Maryland, USA
| | - Ruin Moaddel
- National Institute on Aging, NIH, Baltimore, Maryland, USA
| | - Rafa de Cabo
- National Institute on Aging, NIH, Baltimore, Maryland, USA
| | - Ahmet Hoke
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Jeremy Walston
- Division of Geriatric Medicine and Gerontology.,Department of Medicine, Kyung Hee University, Seoul, South Korea
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9
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Impaired metabolism of kynurenine and its metabolites in CSF of parkinson's disease. Neurosci Lett 2019; 714:134576. [PMID: 31654722 DOI: 10.1016/j.neulet.2019.134576] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 10/15/2019] [Accepted: 10/19/2019] [Indexed: 01/14/2023]
Abstract
AIM The kynurenine (KYN) pathway plays an important role in degrading molecules responsible for oxidative stress in the central nervous system (CNS), but can also have neurotoxic effects. Both 3-hydroxykynurenine (3-HK) and quinolinic acid are neurotoxic metabolites produced from this pathway. In Parkinson's disease (PD), oxidative stress is suspected to represent a key pathogenic mechanism. This study aimed to investigate the function of the KYN pathway and interactions between oxidative stress and neuroinflammation in PD. METHODS Participants comprised 20 patients with PD and 13 controls. Cerebrospinal fluid (CSF) levels of KYN and 3-HK were measured using high-performance liquid chromatography coupled with an electrochemical detector. CSF levels of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, and interferon (IFN)-γ were measured with an enzyme-linked immunosorbent assay, and results were statistically compared between PD patients and controls. RESULTS Median CSF levels of KYN and 3-HK were 49.0 nM and 4.25 nM in PD and 30.5 nM and 1.55 nM in controls, respectively, showing significantly higher levels in PD (p < 0.05). CSF levels of measured cytokines showed that TNF-α and IL-1β were significantly higher in PD patients than in controls. No positive correlation between 3-HK and TNF-α was seen in PD. CONCLUSION Dysfunction of the KYN pathway may induce oxidative stress in the CNS in PD, and may also induce cytokine-mediated neuroinflammation. Functional amelioration of the KYN pathway may facilitate modification of neurodegenerative processes in PD.
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10
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de Oliveira FR, Fantucci MZ, Adriano L, Valim V, Cunha TM, Louzada-Junior P, Rocha EM. Neurological and Inflammatory Manifestations in Sjögren's Syndrome: The Role of the Kynurenine Metabolic Pathway. Int J Mol Sci 2018; 19:ijms19123953. [PMID: 30544839 PMCID: PMC6321004 DOI: 10.3390/ijms19123953] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Revised: 12/04/2018] [Accepted: 12/06/2018] [Indexed: 12/16/2022] Open
Abstract
For decades, neurological, psychological, and cognitive alterations, as well as other glandular manifestations (EGM), have been described and are being considered to be part of Sjögren's syndrome (SS). Dry eye and dry mouth are major findings in SS. The lacrimal glands (LG), ocular surface (OS), and salivary glands (SG) are linked to the central nervous system (CNS) at the brainstem and hippocampus. Once compromised, these CNS sites may be responsible for autonomic and functional disturbances that are related to major and EGM in SS. Recent studies have confirmed that the kynurenine metabolic pathway (KP) can be stimulated by interferon-γ (IFN-γ) and other cytokines, activating indoleamine 2,3-dioxygenase (IDO) in SS. This pathway interferes with serotonergic and glutamatergic neurotransmission, mostly in the hippocampus and other structures of the CNS. Therefore, it is plausible that KP induces neurological manifestations and contributes to the discrepancy between symptoms and signs, including manifestations of hyperalgesia and depression in SS patients with weaker signs of sicca, for example. Observations from clinical studies in acquired immune deficiency syndrome (AIDS), graft-versus-host disease, and lupus, as well as from experimental studies, support this hypothesis. However, the obtained results for SS are controversial, as discussed in this study. Therapeutic strategies have been reexamined and new options designed and tested to regulate the KP. In the future, the confirmation and application of this concept may help to elucidate the mosaic of SS manifestations.
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Affiliation(s)
- Fabíola Reis de Oliveira
- Ribeirao Preto Medical School, Ribeirao Preto, University of Sao Paulo, Ribeirao Preto, SP 14049-900 Brazil.
| | - Marina Zilio Fantucci
- Ribeirao Preto Medical School, Ribeirao Preto, University of Sao Paulo, Ribeirao Preto, SP 14049-900 Brazil.
| | - Leidiane Adriano
- Ribeirao Preto Medical School, Ribeirao Preto, University of Sao Paulo, Ribeirao Preto, SP 14049-900 Brazil.
| | - Valéria Valim
- Espírito Santo Federal University, Vitoria, ES 29075-910, Brazil.
| | - Thiago Mattar Cunha
- Ribeirao Preto Medical School, Ribeirao Preto, University of Sao Paulo, Ribeirao Preto, SP 14049-900 Brazil.
| | - Paulo Louzada-Junior
- Ribeirao Preto Medical School, Ribeirao Preto, University of Sao Paulo, Ribeirao Preto, SP 14049-900 Brazil.
| | - Eduardo Melani Rocha
- Ribeirao Preto Medical School, Ribeirao Preto, University of Sao Paulo, Ribeirao Preto, SP 14049-900 Brazil.
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11
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Navrotskaya V, Wnorowski A, Turski W, Oxenkrug G. Effect of Kynurenic Acid on Pupae Viability of Drosophila melanogaster cinnabar and cardinal Eye Color Mutants with Altered Tryptophan-Kynurenine Metabolism. Neurotox Res 2018; 34:324-331. [PMID: 29619629 DOI: 10.1007/s12640-018-9891-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Revised: 03/15/2018] [Accepted: 03/19/2018] [Indexed: 12/22/2022]
Abstract
Kynurenic acid (KYNA) is one of the metabolites of evolutionary conserved tryptophan (Trp)/kynurenine (Kyn) metabolic pathway. Elevation of KYNA contributes to development of psychosis in schizophrenia but attenuates neurodegeneration in Drosophila model of Huntington's disease. We have reported that KYNA increased lethality of pupae of wild-type flies, but not of vermilion (v) mutants with impaired formation of Kyn from Trp, suggesting that KYNA toxicity depends on its interaction with downstream Kyn metabolites [i.e., 3-hydroxykynurenine (3-HK) and/or xanthurenic acid (XA)]. The present study aimed to further explore the mechanisms of KYNA-induced lethality by the assessment of KYNA effect on pupae of two Drosophila mutants: cinnabar (cn), characterized by higher KYNA and lower 3-HK production, and cardinal (cd), characterized by higher 3-HK and XA levels compared to wild-type flies. Our microarray datamining revealed that the gene expression pattern of enzymes forming Trp/Kyn pathway stands in line with previously reported developmental changes in KYNA, 3-HK, and XA concentrations in wild-type and mutant flies. Administration of KYNA increased pupae lethality in cd, but not in cn mutants. Present data suggest that toxic effect of exogenous KYNA depends on the presence of 3-HK and/or XA. This is further supported by our finding that early stages of Drosophila development are associated with a positive expression pattern of genes encoding sulfotransferases, enzymes that are inhibited by KYNA and are involved in detoxification of XA. Alternatively, the toxic effect of KYNA might depend on anti-proliferative effects of KYNA.
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Affiliation(s)
- Valeriya Navrotskaya
- Department of Genetics and Cytology, V.N. Karazin Kharkiv National University, Kharkiv, Ukraine
| | - Artur Wnorowski
- Department of Biopharmacy, Medical University of Lublin, Chodzki 4a/01a, 20-093, Lublin, Poland
| | - Waldemar Turski
- Department of Experimental and Clinical Pharmacology, Medical University of Lublin, Jaczewskiego 8b, 20-090, Lublin, Poland
| | - Gregory Oxenkrug
- Psychiatry and Inflammation Program, Department of Psychiatry, Tufts University School of Medicine and Tufts Medical Center, 800 Washington St, no. 1107, Boston, MA, 02111, USA.
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Sathyasaikumar KV, Breda C, Schwarcz R, Giorgini F. Assessing and Modulating Kynurenine Pathway Dynamics in Huntington's Disease: Focus on Kynurenine 3-Monooxygenase. Methods Mol Biol 2018; 1780:397-413. [PMID: 29856028 DOI: 10.1007/978-1-4939-7825-0_18] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The link between disturbances in kynurenine pathway (KP) metabolism and Huntington's disease (HD) pathogenesis has been explored for a number of years. Several novel genetic and pharmacological tools have recently been developed to modulate key regulatory steps in the KP such as the reaction catalyzed by the enzyme kynurenine 3-monooxygenase (KMO). This insight has offered new options for exploring the mechanistic link between this metabolic pathway and HD, and provided novel opportunities for the development of candidate drug-like compounds. Here, we present an overview of the field, focusing on some novel approaches for interrogating the pathway experimentally.
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Affiliation(s)
- Korrapati V Sathyasaikumar
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Carlo Breda
- Department of Genetics and Genome Biology, University of Leicester, Leicester, UK
| | - Robert Schwarcz
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Flaviano Giorgini
- Department of Genetics and Genome Biology, University of Leicester, Leicester, UK.
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Sadok I, Gamian A, Staniszewska MM. Chromatographic analysis of tryptophan metabolites. J Sep Sci 2017; 40:3020-3045. [PMID: 28590049 PMCID: PMC5575536 DOI: 10.1002/jssc.201700184] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Revised: 05/15/2017] [Accepted: 05/24/2017] [Indexed: 12/14/2022]
Abstract
The kynurenine pathway generates multiple tryptophan metabolites called collectively kynurenines and leads to formation of the enzyme cofactor nicotinamide adenine dinucleotide. The first step in this pathway is tryptophan degradation, initiated by the rate-limiting enzymes indoleamine 2,3-dioxygenase, or tryptophan 2,3-dioxygenase, depending on the tissue. The balanced kynurenine metabolism, which has been a subject of multiple studies in last decades, plays an important role in several physiological and pathological conditions such as infections, autoimmunity, neurological disorders, cancer, cataracts, as well as pregnancy. Understanding the regulation of tryptophan depletion provide novel diagnostic and treatment opportunities, however it requires reliable methods for quantification of kynurenines in biological samples with complex composition (body fluids, tissues, or cells). Trace concentrations, interference of sample components, and instability of some tryptophan metabolites need to be addressed using analytical methods. The novel separation approaches and optimized extraction protocols help to overcome difficulties in analyzing kynurenines within the complex tissue material. Recent developments in chromatography coupled with mass spectrometry provide new opportunity for quantification of tryptophan and its degradation products in various biological samples. In this review, we present current accomplishments in the chromatographic methodologies proposed for detection of tryptophan metabolites and provide a guide for choosing the optimal approach.
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Affiliation(s)
- Ilona Sadok
- Laboratory of Separation and Spectroscopic Method Applications, Centre for Interdisciplinary ResearchThe John Paul II Catholic University of LublinLublinPoland
| | - Andrzej Gamian
- Laboratory of Medical MicrobiologyHirszfeld Institute of Immunology and Experimental TherapyPolish Academy of SciencesWroclawPoland
- Department of Medical BiochemistryWroclaw Medical UniversityWroclawPoland
| | - Magdalena Maria Staniszewska
- Laboratory of Separation and Spectroscopic Method Applications, Centre for Interdisciplinary ResearchThe John Paul II Catholic University of LublinLublinPoland
- Laboratory of Medical MicrobiologyHirszfeld Institute of Immunology and Experimental TherapyPolish Academy of SciencesWroclawPoland
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14
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Involvement of the kynurenine pathway in the pathogenesis of Parkinson’s disease. Prog Neurobiol 2017; 155:76-95. [DOI: 10.1016/j.pneurobio.2015.12.009] [Citation(s) in RCA: 86] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2015] [Revised: 12/18/2015] [Accepted: 12/30/2015] [Indexed: 12/14/2022]
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15
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3-Hydroxykynurenine and 3-Hydroxyanthranilic Acid Enhance the Toxicity Induced by Copper in Rat Astrocyte Culture. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2017; 2017:2371895. [PMID: 28831293 PMCID: PMC5555010 DOI: 10.1155/2017/2371895] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Accepted: 06/11/2017] [Indexed: 01/15/2023]
Abstract
Copper is an integral component of various enzymes, necessary for mitochondrial respiration and other biological functions. Excess copper is related with neurodegenerative diseases as Alzheimer and is able to modify cellular redox environment, influencing its functions, signaling, and catabolic pathways. Tryptophan degradation through kynurenine pathway produces some metabolites with redox properties as 3-hydroxykynurenine (3-HK) and 3-hydroxyanthranilic acid (3-HANA). The imbalance in their production is related with some neuropathologies, where the common factors are oxidative stress, inflammation, and cell death. This study evaluated the effect of these kynurenines on the copper toxicity in astrocyte cultures. It assessed the CuSO4 effect, alone and in combination with 3-HK or 3-HANA on MTT reduction, ROS production, mitochondrial membrane potential (MMP), GHS levels, and cell viability in primary cultured astrocytes. Also, the chelating copper effect of 3-HK and 3-HANA was evaluated. The results showed that CuSO4 decreased MTT reduction, MMP, and GSH levels while ROS production and cell death are increasing. Coincubation with 3-HK and 3-HANA enhances the toxic effect of copper in all the markers tested except in ROS production, which was abolished by these kynurenines. Data suggest that 3-HK and 3-HANA increased copper toxicity in an independent manner to ROS production.
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de Vries LV, Minović I, Franssen CFM, van Faassen M, Sanders JSF, Berger SP, Navis G, Kema IP, Bakker SJL. The tryptophan/kynurenine pathway, systemic inflammation, and long-term outcome after kidney transplantation. Am J Physiol Renal Physiol 2017; 313:F475-F486. [PMID: 28490533 DOI: 10.1152/ajprenal.00690.2016] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Revised: 04/25/2017] [Accepted: 05/02/2017] [Indexed: 12/14/2022] Open
Abstract
Tryptophan is metabolized along the kynurenine pathway, initially to kynurenine, and subsequently to cytotoxic 3-hydroxykynurenine. There is increasing interest in this pathway because of its proinflammatory nature, and drugs interfering in it have received increasing attention. We aimed to investigate whether serum and urinary parameters of the tryptophan/kynurenine pathway, and particularly cytotoxic 3-hydroxykynurenine, are associated with systemic inflammation and long-term outcome in renal transplant recipients (RTR). Data were collected in outpatient RTR with a functioning graft for >1 yr. Tryptophan, kynurenine, and 3-hydroxykynurenine in serum and urine were measured using LC-MS/MS. A total of 561 RTR (age: 51 ± 12 yr; 56% male) were included at a median of 6.0 (2.6-11.6) yr posttransplantation. Baseline median serum tryptophan was 40.0 (34.5-46.0) µmol/l, serum kynurenine was 1.8 (1.4-2.2) µmol/l, and serum 3-hydroxykynurenine was 42.2 (31.0-61.7) nmol/l. Serum kynurenine and 3-hydroxykynurenine were strongly associated with parameters of systemic inflammation. During follow-up for 7.0 (6.2-7.5) yr, 51 RTR (9%) developed graft failure and 120 RTR (21%) died. Both serum kynurenine and 3-hydroxykynurenine were independently associated with graft failure [HR 1.72 (1.23-2.41), P = 0.002; and HR 2.03 (1.42-2.90), P < 0.001]. Serum 3-hydroxykynurenine was also independently associated with mortality [HR 1.37 (1.08-1.73), P = 0.01], whereas serum kynurenine was not. Urinary tryptophan/kynurenine pathway parameters were not associated with outcome. Of tryptophan metabolites, serum 3-hydroxykynurenine is cross-sectionally most strongly and consistently associated with systemic inflammation and prospectively with adverse long-term outcome after kidney transplantation. Serum 3-hydroxykynurenine may be an interesting biomarker and target for the evaluation of drugs interfering in the tryptophan/kynurenine pathway.
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Affiliation(s)
- Laura V de Vries
- Department of Internal Medicine, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands;
| | - Isidor Minović
- Department of Internal Medicine, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.,Department of Laboratory Medicine, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands; and.,Top Institute Food and Nutrition, Wageningen, The Netherlands
| | - Casper F M Franssen
- Department of Internal Medicine, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Martijn van Faassen
- Department of Laboratory Medicine, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands; and
| | - Jan-Stephan F Sanders
- Department of Internal Medicine, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Stefan P Berger
- Department of Internal Medicine, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Gerjan Navis
- Department of Internal Medicine, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Ido P Kema
- Department of Laboratory Medicine, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands; and
| | - Stephan J L Bakker
- Department of Internal Medicine, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.,Top Institute Food and Nutrition, Wageningen, The Netherlands
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González Esquivel D, Ramírez-Ortega D, Pineda B, Castro N, Ríos C, Pérez de la Cruz V. Kynurenine pathway metabolites and enzymes involved in redox reactions. Neuropharmacology 2017; 112:331-345. [DOI: 10.1016/j.neuropharm.2016.03.013] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2015] [Revised: 02/28/2016] [Accepted: 03/06/2016] [Indexed: 11/27/2022]
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18
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Fujigaki H, Yamamoto Y, Saito K. L-Tryptophan-kynurenine pathway enzymes are therapeutic target for neuropsychiatric diseases: Focus on cell type differences. Neuropharmacology 2017; 112:264-274. [DOI: 10.1016/j.neuropharm.2016.01.011] [Citation(s) in RCA: 93] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Revised: 12/28/2015] [Accepted: 01/05/2016] [Indexed: 12/31/2022]
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Cuartero MI, de la Parra J, García-Culebras A, Ballesteros I, Lizasoain I, Moro MÁ. The Kynurenine Pathway in the Acute and Chronic Phases of Cerebral Ischemia. Curr Pharm Des 2016; 22:1060-73. [PMID: 25248805 DOI: 10.2174/1381612822666151214125950] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2015] [Accepted: 12/11/2015] [Indexed: 12/12/2022]
Abstract
Kynurenines are a wide range of catabolites which derive from tryptophan through the "Kynurenine Pathway" (KP). In addition to its peripheral role, increasing evidence shows a role of the KP in the central nervous system (CNS), mediating both physiological and pathological functions. Indeed, an imbalance in this route has been associated with several neurodegenerative disorders such as Alzheimer´s and Huntington´s diseases. Altered KP catabolism has also been described during both acute and chronic phases of stroke; however the contribution of the KP to the pathophysiology of acute ischemic damage and of post-stroke disorders during the chronic phase including depression and vascular dementia, and the exact mechanisms implicated in the regulation of the KP after stroke are not well established yet. A better understanding of the regulation and activity of the KP after stroke could provide new pharmacological tools in both acute and chronic phases of stroke. In this review, we will make an overview of CNS modulation by the KP. We will detail the KP contribution in the ischemic damage, how the unbalance of the KP might trigger an alteration of the cognitive function after stroke as well as potential targets for the development of new drugs.
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Affiliation(s)
- María Isabel Cuartero
- Unidad de Investigación Neurovascular, Departamento de Farmacología, Facultad de Medicina, Universidad Complutense, Avenida Complutense s/n, 28040 Madrid, Spain.
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Eskelund A, Budac DP, Sanchez C, Elfving B, Wegener G. Female Flinders Sensitive Line rats show estrous cycle-independent depression-like behavior and altered tryptophan metabolism. Neuroscience 2016; 329:337-48. [DOI: 10.1016/j.neuroscience.2016.05.024] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Revised: 05/11/2016] [Accepted: 05/11/2016] [Indexed: 01/28/2023]
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21
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Khandaker GM, Dantzer R. Is there a role for immune-to-brain communication in schizophrenia? Psychopharmacology (Berl) 2016; 233:1559-73. [PMID: 26037944 PMCID: PMC4671307 DOI: 10.1007/s00213-015-3975-1] [Citation(s) in RCA: 104] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Accepted: 05/22/2015] [Indexed: 02/06/2023]
Abstract
Schizophrenia is characterised by hallucinations, delusions, depression-like so-called negative symptoms, cognitive dysfunction, impaired neurodevelopment and neurodegeneration. Epidemiological and genetic studies strongly indicate a role of inflammation and immunity in the pathogenesis of symptoms of schizophrenia. Evidence accrued over the last two decades has demonstrated that there are a number of pathways through which systemic inflammation can exert profound influence on the brain leading to changes in mood, cognition and behaviour. The peripheral immune system-to-brain communication pathways have been studied extensively in the context of depression where inflammatory cytokines are thought to play a key role. In this review, we highlight novel evidence suggesting an important role of peripheral immune-to-brain communication pathways in schizophrenia. We discuss recent population-based longitudinal studies that report an association between elevated levels of circulating inflammatory cytokines and subsequent risk of psychosis. We discuss emerging evidence indicating potentially important role of blood-brain barrier endothelial cells in peripheral immune-to-brain communication, which may be also relevant for schizophrenia. Drawing on clinical and preclinical studies, we discuss whether immune-mediated mechanisms could help to explain some of the clinical and pathophysiological features of schizophrenia. We discuss implication of these findings for approaches to diagnosis, treatment and research in future. Finally, pointing towards links with early-life adversity, we consider whether persistent low-grade activation of the innate immune response, as a result of impaired foetal or childhood development, could be a common mechanism underlying the high comorbidity between certain neuropsychiatric and physical illnesses, such as schizophrenia, depression, heart disease and type-two diabetes.
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Affiliation(s)
- Golam M Khandaker
- Department of Psychiatry, University of Cambridge, Box 189, Cambridge Biomedical Campus, Cambridge, CB2 2QQ, UK.
| | - Robert Dantzer
- Department of Symptom Research, Division of Internal Medicine, MD Anderson Cancer Center, Houston, TX, USA
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22
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Notarangelo FM, Wang XD, Horning KJ, Schwarcz R. Role of d-amino acid oxidase in the production of kynurenine pathway metabolites from d-tryptophan in mice. J Neurochem 2016; 136:804-814. [PMID: 26661897 DOI: 10.1111/jnc.13455] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Revised: 11/23/2015] [Accepted: 11/25/2015] [Indexed: 02/01/2023]
Abstract
The kynurenine pathway (KP), the major catabolic route of the essential amino acid l-tryptophan (l-TRP), contains several neuroactive compounds, including kynurenic acid, 3-hydroxykynurenine (3-HK), and quinolinic acid (QUIN). The role of the d-enantiomer (d-TRP) in KP metabolism has received little attention so far. d-TRP can be converted to l-TRP by d-amino acid oxidase, and the same enzyme can produce d-kynurenine, a known bioprecursor of KYNA. To analyze these complex metabolic events systematically in vivo, we injected mice with d-TRP (300 mg/kg, i.p.) and examined KP metabolism in the absence or presence of the d-amino acid oxidase inhibitor 3-methylpyrazole-5-carboxylic acid (MPC; 100 mg/kg, i.p.,). After 90 min, newly formed l-TRP was recovered in plasma, liver, forebrain, and cerebellum, and MPC prevented its neosynthesis in all tissues. In the same animals, de novo production of d-kynurenine from d-TRP was also observed, but was much higher in the periphery than in the brain. d-TRP administration raised KYNA, 3-HK, and QUIN levels in all tissues examined, and KYNA production from d-TRP was significantly reduced after pre-treatment with MPC. These results indicate that catabolic routes other than those classically ascribed to l-TRP and l-kynurenine can account for the synthesis of KYNA, 3-HK and QUINin vivo. The essential amino acid l-tryptophan is catabolized via the kynurenine pathway (KP). We explored the role of the d-enantiomer in KP metabolism in mice in vivo. We report that d-tryptophan is metabolized in both brain and periphery and converted to KP metabolites, including d-kynurenine and l-kynurenine, kynurenic acid, 3-hydroxykynurenine, and quinolinic acid. Pharmacological experiments confirm the involvement of d-amino acid oxidase in these processes. Our results indicate that this enzyme participates in the synthesis of KP metabolites from d-tryptophan.
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Affiliation(s)
- Francesca M Notarangelo
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Xiao-Dan Wang
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Kyle J Horning
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Robert Schwarcz
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, Maryland, USA
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Reyes-Ocampo J, Ramírez-Ortega D, Vázquez Cervantes G, Pineda B, Montes de Oca Balderas P, González-Esquivel D, Sánchez-Chapul L, Lugo-Huitrón R, Silva-Adaya D, Ríos C, Jiménez-Anguiano A, Pérez-de la Cruz V. Mitochondrial dysfunction related to cell damage induced by 3-hydroxykynurenine and 3-hydroxyanthranilic acid: Non-dependent-effect of early reactive oxygen species production. Neurotoxicology 2015; 50:81-91. [DOI: 10.1016/j.neuro.2015.08.003] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Revised: 07/16/2015] [Accepted: 08/03/2015] [Indexed: 01/09/2023]
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Parrott JM, O'Connor JC. Kynurenine 3-Monooxygenase: An Influential Mediator of Neuropathology. Front Psychiatry 2015; 6:116. [PMID: 26347662 PMCID: PMC4542134 DOI: 10.3389/fpsyt.2015.00116] [Citation(s) in RCA: 79] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Accepted: 08/03/2015] [Indexed: 12/13/2022] Open
Abstract
Mounting evidence demonstrates that kynurenine metabolism may play an important pathogenic role in the development of multiple neurological and neuropsychiatric disorders. The kynurenine pathway consists of two functionally distinct branches that generate both neuroactive and oxidatively reactive metabolites. In the brain, the rate-limiting enzyme for one of these branches, kynurenine 3-monooxygenase (KMO), is predominantly expressed in microglia and has emerged as a pivotal point of metabolic regulation. KMO substrate and expression levels are upregulated by pro-inflammatory cytokines and altered by functional genetic mutations. Increased KMO metabolism results in the formation of metabolites that activate glutamate receptors and elevate oxidative stress, while recent evidence has revealed neurodevelopmental consequences of reduced KMO activity. Together, the evidence suggests that KMO is positioned at a critical metabolic junction to influence the development or trajectory of a myriad of neurological diseases. Understanding the mechanism(s) by which alterations in KMO activity are able to impair neuronal function, and viability will enhance our knowledge of related disease pathology and provide insight into novel therapeutic opportunities. This review will discuss the influence of KMO on brain kynurenine metabolism and the current understanding of molecular mechanisms by which altered KMO activity may contribute to neurodevelopment, neurodegenerative, and neuropsychiatric diseases.
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Affiliation(s)
- Jennifer M Parrott
- Department of Pharmacology, School of Medicine, University of Texas Health Science Center at San Antonio , San Antonio, TX , USA ; Center for Biomedical Neuroscience, University of Texas Health Science Center at San Antonio , San Antonio, TX , USA
| | - Jason C O'Connor
- Department of Pharmacology, School of Medicine, University of Texas Health Science Center at San Antonio , San Antonio, TX , USA ; Center for Biomedical Neuroscience, University of Texas Health Science Center at San Antonio , San Antonio, TX , USA ; Mood Disorders Translational Research Core, University of Texas Health Science Center at San Antonio , San Antonio, TX , USA ; Audie L. Murphy Memorial VA Hospital, South Texas Veterans Health System , San Antonio, TX , USA
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25
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Colín-González AL, Maya-López M, Pedraza-Chaverrí J, Ali SF, Chavarría A, Santamaría A. The Janus faces of 3-hydroxykynurenine: Dual redox modulatory activity and lack of neurotoxicity in the rat striatum. Brain Res 2014; 1589:1-14. [DOI: 10.1016/j.brainres.2014.09.034] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2014] [Revised: 09/07/2014] [Accepted: 09/14/2014] [Indexed: 12/14/2022]
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Klinkenberg S, van den Borne CJH, Aalbers MW, Verschuure P, Kessels AG, Leenen L, Rijkers K, Aldenkamp AP, Vles JSH, Majoie HJM. The effects of vagus nerve stimulation on tryptophan metabolites in children with intractable epilepsy. Epilepsy Behav 2014; 37:133-8. [PMID: 25022821 DOI: 10.1016/j.yebeh.2014.06.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Revised: 06/02/2014] [Accepted: 06/04/2014] [Indexed: 10/25/2022]
Abstract
BACKGROUND The mechanism of action of vagus nerve stimulation (VNS) in intractable epilepsy is not entirely clarified. It is believed that VNS causes alterations in cytokines, which can lead to rebalancing the release of neurotoxic and neuroprotective tryptophan metabolites. We aimed to evaluate VNS effects on tryptophan metabolites and on epileptic seizures and investigated whether the antiepileptic effectiveness correlated with changes in tryptophan metabolism. METHODS Forty-one children with intractable epilepsy were included in a randomized, active-controlled, double-blind study. After a baseline period of 12 weeks, all children underwent implantation of a vagus nerve stimulator and entered a blinded active-controlled phase of 20 weeks. Half of the children received high-output (therapeutic) stimulation (n=21), while the other half received low-output (active control) stimulation (n=20). Subsequently, all children received high-output stimulation for another 19 weeks (add-on phase). Tryptophan metabolites were assessed in plasma and cerebrospinal fluid (CSF) by use of liquid chromatography-tandem mass spectrometry (LC-MS/MS) and compared between high- and low-output groups and between the end of both study phases and baseline. Seizure frequency was recorded using seizure diaries. Mood was assessed using Profile of Mood States (POMS) questionnaires. RESULTS Regarding tryptophan metabolites, anthranilic acid (AA) levels were significantly higher at the end of the add-on phase compared with baseline (p=0.002) and correlated significantly with improvement of mood (τ=-0.39, p=0.037) and seizure frequency reduction (τ=-0.33, p<0.01). No significant changes were found between high- and low-output groups regarding seizure frequency. CONCLUSION Vagus nerve stimulation induces a consistent increase in AA, a neuroprotective and anticonvulsant tryptophan metabolite. Moreover, increased AA levels are associated with improvement in mood and reduction of seizure frequency.
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Affiliation(s)
- S Klinkenberg
- Department of Neurology, Maastricht University Medical Center, The Netherlands; School for Mental Health and Neuroscience, Maastricht University, The Netherlands.
| | | | - M W Aalbers
- Department of Neurology, Maastricht University Medical Center, The Netherlands; School for Mental Health and Neuroscience, Maastricht University, The Netherlands
| | - P Verschuure
- Epilepsy Center Kempenhaeghe, Heeze, The Netherlands
| | - A G Kessels
- Department of Clinical Epidemiology and Medical Technology Assessment, Maastricht University Medical Center, The Netherlands
| | - L Leenen
- Epilepsy Center Kempenhaeghe, Heeze, The Netherlands
| | - K Rijkers
- School for Mental Health and Neuroscience, Maastricht University, The Netherlands; Department of Neurosurgery, Maastricht University Medical Center, The Netherlands
| | - A P Aldenkamp
- Department of Neurology, Maastricht University Medical Center, The Netherlands; Epilepsy Center Kempenhaeghe, Heeze, The Netherlands; Eindhoven University of Technology, Eindhoven, The Netherlands
| | - J S H Vles
- Department of Neurology, Maastricht University Medical Center, The Netherlands; School for Mental Health and Neuroscience, Maastricht University, The Netherlands; Epilepsy Center Kempenhaeghe, Heeze, The Netherlands
| | - H J M Majoie
- Department of Neurology, Maastricht University Medical Center, The Netherlands; School for Mental Health and Neuroscience, Maastricht University, The Netherlands; Epilepsy Center Kempenhaeghe, Heeze, The Netherlands
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Is there a role for glutamate-mediated excitotoxicity in inflammation-induced depression? J Neural Transm (Vienna) 2014; 121:925-32. [PMID: 24633997 DOI: 10.1007/s00702-014-1187-1] [Citation(s) in RCA: 75] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2013] [Accepted: 02/26/2014] [Indexed: 12/20/2022]
Abstract
Chronic inflammation in physically ill patients is often associated with the development of symptoms of depression. The mechanisms that are responsible for inflammation-associated depression have been elucidated over the last few years. Kynurenine produced from tryptophan in a reaction catabolized by indoleamine 2,3 dioxygenase is transported into the brain where it is metabolized by microglial enzymes into a number of neurotropic compounds including quinolinic acid, an agonist of N-methyl-D-aspartate receptors. Quinolinic acid can synergize with glutamate released by activated microglia. This chain of events opens the possibility to treat inflammation-induced depression using therapies that target the transport of kynurenine through the blood-brain barrier, the production of quinolinic acid and glutamate by activated microglia, or the efflux of glutamate from the brain to the blood.
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Reyes Ocampo J, Lugo Huitrón R, González-Esquivel D, Ugalde-Muñiz P, Jiménez-Anguiano A, Pineda B, Pedraza-Chaverri J, Ríos C, Pérez de la Cruz V. Kynurenines with neuroactive and redox properties: relevance to aging and brain diseases. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2014; 2014:646909. [PMID: 24693337 PMCID: PMC3945746 DOI: 10.1155/2014/646909] [Citation(s) in RCA: 84] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/10/2013] [Revised: 12/12/2013] [Accepted: 12/15/2013] [Indexed: 11/18/2022]
Abstract
The kynurenine pathway (KP) is the main route of tryptophan degradation whose final product is NAD(+). The metabolism of tryptophan can be altered in ageing and with neurodegenerative process, leading to decreased biosynthesis of nicotinamide. This fact is very relevant considering that tryptophan is the major source of body stores of the nicotinamide-containing NAD(+) coenzymes, which is involved in almost all the bioenergetic and biosynthetic metabolism. Recently, it has been proposed that endogenous tryptophan and its metabolites can interact and/or produce reactive oxygen species in tissues and cells. This subject is of great importance due to the fact that oxidative stress, alterations in KP metabolites, energetic deficit, cell death, and inflammatory events may converge each other to enter into a feedback cycle where each one depends on the other to exert synergistic actions among them. It is worth mentioning that all these factors have been described in aging and in neurodegenerative processes; however, has so far no one established any direct link between alterations in KP and these factors. In this review, we describe each kynurenine remarking their redox properties, their effects in experimental models, their alterations in the aging process.
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Affiliation(s)
- Jazmin Reyes Ocampo
- Departamento de Neuroquímica, Instituto Nacional de Neurología y Neurocirugía Manuel Velasco Suárez, S.S.A., Insurgentes Sur 3877, 14269 México, DF, Mexico
- Área de Neurociencias, Departamento de Biología de la Reproducción, Universidad Autónoma Metropolitana-Iztapalapa, 09340 México, DF, Mexico
| | - Rafael Lugo Huitrón
- Departamento de Neuroquímica, Instituto Nacional de Neurología y Neurocirugía Manuel Velasco Suárez, S.S.A., Insurgentes Sur 3877, 14269 México, DF, Mexico
| | - Dinora González-Esquivel
- Departamento de Neuroquímica, Instituto Nacional de Neurología y Neurocirugía Manuel Velasco Suárez, S.S.A., Insurgentes Sur 3877, 14269 México, DF, Mexico
| | - Perla Ugalde-Muñiz
- Departamento de Neuroquímica, Instituto Nacional de Neurología y Neurocirugía Manuel Velasco Suárez, S.S.A., Insurgentes Sur 3877, 14269 México, DF, Mexico
| | - Anabel Jiménez-Anguiano
- Área de Neurociencias, Departamento de Biología de la Reproducción, Universidad Autónoma Metropolitana-Iztapalapa, 09340 México, DF, Mexico
| | - Benjamín Pineda
- Laboratorio de Neuroinmunología, Instituto Nacional de Neurología y Neurocirugía Manuel Velasco Suárez, S.S.A., 14269 México, DF, Mexico
| | - José Pedraza-Chaverri
- Departamento de Biología, Facultad de Química, Universidad Nacional Autónoma de México, 04510 México, DF, Mexico
| | - Camilo Ríos
- Departamento de Neuroquímica, Instituto Nacional de Neurología y Neurocirugía Manuel Velasco Suárez, S.S.A., Insurgentes Sur 3877, 14269 México, DF, Mexico
| | - Verónica Pérez de la Cruz
- Departamento de Neuroquímica, Instituto Nacional de Neurología y Neurocirugía Manuel Velasco Suárez, S.S.A., Insurgentes Sur 3877, 14269 México, DF, Mexico
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Mazarei G, Budac DP, Lu G, Adomat H, Tomlinson Guns ES, Möller T, Leavitt BR. Age-dependent alterations of the kynurenine pathway in the YAC128 mouse model of Huntington disease. J Neurochem 2013; 127:852-67. [PMID: 23786539 DOI: 10.1111/jnc.12350] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2013] [Revised: 06/14/2013] [Accepted: 06/17/2013] [Indexed: 02/03/2023]
Abstract
Indoleamine 2,3 dioxygenase (Ido1), the first and rate-limiting enzyme of the kynurenine pathway (KP), is a striatally enriched gene with increased expression levels in the YAC128 mouse model of Huntington disease (HD). Our objective in this study was to delineate age-related KP alterations in this model. Three enzymes potentially catalyze the first step of the KP; Ido1 and Indoleamine 2,3 dioxygenase-2 were highly expressed in the striatum and Tryptophan 2,3 dioxygenase (Tdo2) in the cerebellum. During development, Ido1 mRNA expression is dynamically regulated and chronically up-regulated in YAC128 mice. Kynurenine (Kyn) to tryptophan (Trp) ratio, a measure of activity in the first step of the KP, was elevated in YAC128 striatum, but no change in Tdo2 mRNA levels or Kyn to Trp ratio was detected in the cerebellum. Ido1 induction was coincident with Trp depletion at 3 months and Kyn accumulation at 12 months of age in striatum. Changes in downstream KP metabolites of YAC128 mice generally followed a biphasic pattern with neurotoxic metabolites reduced at 3 months and increased at 12 months of age. Striatally specific induction of Ido1 and downstream KP alterations suggest involvement in HD pathogenesis, and should be taken into account in future therapeutic developments for HD.
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Affiliation(s)
- Gelareh Mazarei
- Centre for Molecular Medicine & Therapeutics and Department of Medical Genetics, University of British Columbia, Vancouver, British Columbia, Canada
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Increased 3-hydroxykynurenine serum concentrations differentiate Alzheimer's disease patients from controls. Eur Arch Psychiatry Clin Neurosci 2013. [PMID: 23192697 DOI: 10.1007/s00406-012-0384-x] [Citation(s) in RCA: 92] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Increased degradation of tryptophan (TRP) through the kynurenine (KYN) pathway (KP) is known to be involved in the molecular mechanisms resulting in the neuropathogenesis of Alzheimer's disease (AD). Activation of the KP leads to the production of neurotoxic metabolites 3-hydroxykynurenine (3-HK) and quinolinic acid (QUIN) by immune cells and neuroprotective derivates kynurenic acid (KYNA) and picolinic acid (PIC) by astrocytes and neurons. We therefore investigated whether an imbalance between neurotoxic and neuroprotective kynurenine metabolites could be detected in patients with AD. We measured serum levels of TRP, KYNA, 3-HK, PIC and QUIN in 20 patients with AD and for comparison in 20 patients with major depression, and 19 subjectively cognitive impaired subjects. Serum levels of 3-HK were markedly increased in AD patients compared to the comparison groups (p < .0001). Serum levels of the other KP metabolites were not significantly different between groups. Our data indicate an increased production of the neurotoxic KP metabolite 3-HK in AD. In contrast to its downstream metabolites QUIN and PIC, 3-HK can cross the blood-brain barrier via an active transport process. Our data therefore indicate an enhanced availability of 3-HK in the brain of AD patients, which may be related to the previously reported higher production of QUIN in AD brains.
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Colín-González AL, Maldonado PD, Santamaría A. 3-Hydroxykynurenine: an intriguing molecule exerting dual actions in the central nervous system. Neurotoxicology 2012; 34:189-204. [PMID: 23219925 DOI: 10.1016/j.neuro.2012.11.007] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2012] [Revised: 11/23/2012] [Accepted: 11/27/2012] [Indexed: 11/26/2022]
Abstract
Kynurenine pathway is gaining attention due to the many metabolic processes in which it has been involved. The tryptophan conversion into several other metabolites through this pathway provides neuronal and redox modulators useful for maintenance of major functions in the brain. However, when physiopathological conditions prevail - i.e. oxidative stress, excitotoxicity, and inflammation - preferential formation and accumulation of toxic metabolites could trigger factors for degeneration in neurological disorders. 3-Hydroxykynurenine has been largely described as one of these toxic metabolites capable of inducing oxidative damage and cell death; consequently, this metabolite has been hypothesized to play a pivotal role in different neurological and psychiatric disorders. Supporting evidence has shown altered 3-hydroxykynurenine levels in samples of patients from several disorders. In contrast, some experimental studies have provided evidence of antioxidant and scavenging properties inherent to this molecule. In this review, we explored most of literature favoring one or the other concept, in order to provide an accurate vision on the real participation of this tryptophan metabolite in both experimental paradigms and human brain pathologies. Through this collected evidence, we provide an integrative hypothesis on how 3-hydroxykynurenine is exerting its dual actions in the central nervous system and what will be the course of investigations in this field for the next years.
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Affiliation(s)
- Ana Laura Colín-González
- Laboratorio de Aminoácidos Excitadores, Instituto Nacional de Neurología y Neurocirugía, Insurgentes Sur 3877, Mexico City 14269, Mexico
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Abstract
Over the last two decades, evidence for the involvement of quinolinic acid (QUIN) in neuroinflammatory diseases has been exponentially increasing. Within the brain, QUIN is produced and released by infiltrating macrophages and activated microglia, the very cells that are prominent during neuroinflammation. QUIN acts as an agonist of the N-methyl-D-aspartate receptor and as such is considered to be a brain endogenous excitotoxin. Since the discovery of the excitotoxic activity of QUIN in the early 1980s, several other cytotoxic mechanisms have been identified. We know today that QUIN acts as a neurotoxin, gliotoxin, proinflammatory mediator, pro-oxidant molecule and can alter the integrity and cohesion of the blood-brain barrier. This paper aims to review some of the most recent findings about the effects of QUIN and its mode of action.
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Affiliation(s)
- Gilles J Guillemin
- Department of Pharmacology, School of Medical Sciences, University of New South Wales, Sydney, NSW, Australia.
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Krause D, Suh HS, Tarassishin L, Cui QL, Durafourt BA, Choi N, Bauman A, Cosenza-Nashat M, Antel JP, Zhao ML, Lee SC. The tryptophan metabolite 3-hydroxyanthranilic acid plays anti-inflammatory and neuroprotective roles during inflammation: role of hemeoxygenase-1. THE AMERICAN JOURNAL OF PATHOLOGY 2011; 179:1360-72. [PMID: 21855684 DOI: 10.1016/j.ajpath.2011.05.048] [Citation(s) in RCA: 109] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2011] [Revised: 04/25/2011] [Accepted: 05/06/2011] [Indexed: 11/26/2022]
Abstract
Tryptophan metabolism by the kynurenine pathway (KP) is important to the pathogenesis of inflammatory, infectious, and degenerative diseases. The 3-hydroxykynurenine (3-HK) branch of the KP is activated in macrophages and microglia, leading to the generation of 3-HK, 3-hydroxyanthranilic acid (3-HAA), and quinolinic acid, which are considered neurotoxic owing to their free radical-generating and N-methyl-d-aspartic acid receptor agonist activities. We investigated the role of 3-HAA in inflammatory and antioxidant gene expression and neurotoxicity in primary human fetal central nervous system cultures treated with cytokines (IL-1 with or without interferon-γ) or with Toll-like receptor ligands mimicking the proinflammatory central nervous system environment. Results were analyzed by microarray, Western blot, immunostain, enzyme-linked immunosorbent assay, and neurotoxicity assays. 3-HAA suppressed glial cytokine and chemokine expression and reduced cytokine-induced neuronal death. 3-HK also suppressed cytokine-induced neuronal death. Unexpectedly, 3-HAA was highly effective in inducing in astrocytes the expression of hemeoxygenase-1 (HO-1), an antioxidant enzyme with anti-inflammatory and cytoprotective properties. Optimal induction of HO-1 required 3-HAA and cytokines. In human microglia, 3-HAA weakly induced HO-1 and lipopolysaccharide suppressed microglial HO-1 expression. 3-HAA-mediated HO-1 expression was confirmed in cultured adult human astrocytes and in vivo after 3-HAA injection to mouse brains. Together, our results demonstrate the novel neuroprotective activity of the tryptophan metabolite 3-HAA and have implications for future therapeutic approaches for neuroinflammatory disorders.
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Affiliation(s)
- Daniela Krause
- Department of Pathology (Neuropathology), Albert Einstein College of Medicine, Bronx, New York, USA
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Forrest CM, Mackay GM, Oxford L, Millar K, Darlington LG, Higgins MJ, Stone TW. Kynurenine metabolism predicts cognitive function in patients following cardiac bypass and thoracic surgery. J Neurochem 2011; 119:136-52. [DOI: 10.1111/j.1471-4159.2011.07414.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Stone TW, Forrest CM, Stoy N, Darlington LG. Involvement of kynurenines in Huntington's disease and stroke-induced brain damage. J Neural Transm (Vienna) 2011; 119:261-74. [PMID: 21695417 DOI: 10.1007/s00702-011-0676-8] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2011] [Accepted: 06/08/2011] [Indexed: 01/13/2023]
Abstract
Several components of the kynurenine pathway of tryptophan metabolism are now recognised to have actions of profound biological importance. These include the ability to modulate the activation of glutamate and nicotinic receptors, to modify the responsiveness of the immune system to inflammation and infection, and to modify the generation and removal of reactive oxygen species. As each of these factors is being recognised increasingly as contributing to major disorders of the central nervous system (CNS), so the potentially fundamental role of the kynurenine pathway in those disorders is presenting a valuable target both for understanding the progress of those disorders and for developing potential drug treatments. This review will summarise some of the evidence for an important contribution of the kynurenines to Huntington's disease and to stroke damage in the CNS. Together with preliminary evidence from a study of kynurenine metabolites after major surgery, an important conclusion is that kynurenine pathway activation closely reflects cognitive function, and may play a significant role in cognitive ability.
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Affiliation(s)
- Trevor W Stone
- Institute of Neuroscience and Psychology, West Medical Building, University of Glasgow, Glasgow, G12 8QQ, UK.
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de Souza FRS, Fontes FL, da Silva TA, Coutinho LG, Leib SL, Agnez-Lima LF. Association of kynurenine aminotransferase II gene C401T polymorphism with immune response in patients with meningitis. BMC MEDICAL GENETICS 2011; 12:51. [PMID: 21473761 PMCID: PMC3084162 DOI: 10.1186/1471-2350-12-51] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/26/2010] [Accepted: 04/07/2011] [Indexed: 12/16/2022]
Abstract
Background The kynurenine (KYN) pathway has been shown to be altered in several diseases which compromise the central nervous system (CNS) including infectious diseases such as bacterial meningitis (BM). The aim of this study was to assess single nucleotide polymorphisms (SNPs) in four genes of KYN pathway in patients with meningitis and their correlation with markers of immune response in BM. Methods One hundred and one individuals were enrolled in this study to investigate SNPs in the following genes: indoleamine-2,3-dioxygenase (IDO1 gene), kynureninase (KYNU gene), kynurenine aminotransferase I (CCBL1 gene), and kynurenine aminotransferase II (AADAT gene). SNP analyses were performed by primer-introduced restriction analysis-PCR (PIRA-PCR) followed by RFLP. Cytokines were measured using multiplex bead assay while immunoglobulins (IG) by immunodiffusion plates and NF-kappaB and c-Jun by dot blot assay. Results The variant allele of SNP AADAT+401C/T showed prevalent frequency in patients with BM. A significant decrease (p < 0.05) in TNF-α, IL-1β, IL-6, MIP-1αCCL3 and MIP-1β/CCL4 levels was observed in BM patients homozygous (TT) to the SNP AADAT+401C/T. Furthermore, a significant (p < 0.05) decrease in cell count was observed in cerebrospinal fluid (CSF) from patients with TT genotype. In addition, an increase in the IgG level in adults (p < 0.05) was observed. The variant allele for KYNU+715G/A was found with low frequency in the groups, and the SNPs in IDO1+434T/G, KYNU+693G/A, CCBL1+164T/C, and AADAT+650C/T had no frequency in this population. Conclusions This study is the first report of an association of SNP AADAT+401C/T with the host immune response to BM, suggesting that this SNP may affect the host ability in recruitment of leukocytes to the infection site. This finding may contribute to identifying potential targets for pharmacological intervention as adjuvant therapy for BM.
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Vascular expression, activity and function of indoleamine 2,3-dioxygenase-1 following cerebral ischaemia-reperfusion in mice. Naunyn Schmiedebergs Arch Pharmacol 2011; 383:471-81. [PMID: 21359968 DOI: 10.1007/s00210-011-0611-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2011] [Accepted: 02/02/2011] [Indexed: 01/24/2023]
Abstract
Indoleamine 2,3-dioxygenases-1 (Ido1) and -2 initiate the kynurenine pathway of tryptophan metabolism. In addition to the established immune regulatory effects of Ido1 and the ability of nitric oxide to regulate Ido1 activity, it is now also known that Ido1-mediated metabolism of tryptophan to kynurenine can modulate vascular tone. Ido activity is reportedly elevated in stroke patients and correlates with increased risk of death. Thus, the present goals were to test whether, following cerebral ischaemia, Ido activity and cerebrovascular Ido1 expression are altered and whether expression of Ido1 contributes to stroke outcome. Transient cerebral ischaemia was induced in wild-type and Ido1 gene-deficient (Ido1 (-/-)) mice. Mice were pre-treated with vehicle, the Ido1 inhibitor, 1-methyl-D-tryptophan (1-MT; 50 mg/kg i.p.) or the inducible nitric oxide synthase (Nos2) inhibitor, aminoguanidine (AG, 100 mg/kg i.p.). At 24 h, neurological function, brain infarct size and swelling were assessed. In addition, Ido activity was estimated by plasma kynurenine and tryptophan, and Ido1 expression was examined in cerebral arterioles. Cerebral ischaemia-reperfusion in wild-type mice increased Ido activity and its expression in cerebral arterioles. Ido1 (-/-) and 1-MT-treated wild-type mice had lower Ido activity but similar post-stroke neurological function and similar total brain infarct volume and swelling, relative to control mice. Inhibition of Nos2 with AG also did not affect Ido activity or outcome following stroke. This study provides molecular and pharmacological evidence that the expression and the activity of Ido1 increase following stroke. However, such Ido1 expression does not appear to affect overall outcome following acute ischaemic stroke, and furthermore, a regulatory role of Nos2-derived nitric oxide on Ido activity following cerebral ischaemia-reperfusion appears unlikely.
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Khabazghazvini B, Groer M, Fuchs D, Strassle P, Lapidus M, Sleemi A, Cabassa JB, Postolache TT. Psychiatric manifestations of latent toxoplasmosis. Potential mediation by indoleamine 2,3-dioxygenase. ACTA ACUST UNITED AC 2010. [DOI: 10.1515/ijdhd.2010.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Lim CK, Brew BJ, Sundaram G, Guillemin GJ. Understanding the roles of the kynurenine pathway in multiple sclerosis progression. Int J Tryptophan Res 2010; 3:157-67. [PMID: 22084596 PMCID: PMC3195238 DOI: 10.4137/ijtr.s4294] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
The kynurenine pathway (KP) is a major degradative pathway of tryptophan ultimately leading to the production of nicotinamide adenine dinucleotide (NAD+) and is also one of the major regulatory mechanisms of the immune response. The KP is known to be involved in several neuroinflammatory disorders including Alzheimer’s disease, amyotrophic lateral sclerosis, AIDS dementia complex, Parkinson’s disease, schizophrenia, Huntington’s disease and brain tumours. However, the KP remains a relatively new topic for the field of multiple sclerosis (MS). Over the last 2–3 years, some evidence has progressively emerged suggesting that the KP is likely to be involved in the pathogenesis of autoimmune diseases especially MS. Some KP modulators are already in clinical trials for other inflammatory diseases and would potentially provide a new and important therapeutic strategy for MS patients. This review summarizes the known relationships between the KP and MS.
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Affiliation(s)
- Chai K Lim
- Department of Pharmacology, School of Medical Sciences, University of New South Wales, Sydney 2052, Australia
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40
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Abstract
Alzheimer’s disease (AD) is one of the major causes of dementia. The pathogenesis of the disease is not entirely understood, but the amyloid β peptide (Aβ) and the formation of senile plaques seem to play pivotal roles. Oligomerization of the Aβ is thought to trigger a cascade of events, including oxidative stress, glutamate excitotoxicity and inflammation. The kynurenine (KYN) pathway is the major route for the metabolism of the essential amino acid tryptophan. Some of the metabolites of this pathway, such as 3-hydroxykynurenine and quinolinic acid, are known to have neurotoxic properties, whereas others, such as kynurenic acid, are putative neuroprotectants. Among other routes, the KYN pathway has been shown to be involved in AD pathogenesis, and connections to other known mechanisms have also been demonstrated. Oxidative stress, glutamate excitotoxicity and the neuroinflammation involved in AD pathogenesis have been revealed to be connected to the KYN pathway. Intervention at these key steps may serve as the aim of potential therapy.
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Affiliation(s)
- Zsigmond Tamas Kincses
- Department of Neurology, Albert Szent-Györgyi Clinical Center, University of Szeged, Hungary
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Davies NW, Guillemin G, Brew BJ. Tryptophan, Neurodegeneration and HIV-Associated Neurocognitive Disorder. Int J Tryptophan Res 2010; 3:121-40. [PMID: 22084594 PMCID: PMC3195234 DOI: 10.4137/ijtr.s4321] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
This review presents an up-to-date assessment of the role of the tryptophan metabolic and catabolic pathways in neurodegenerative disease and HIV-associated neurocognitive disorder. The kynurenine pathway and the effects of each of its enzymes and products are reviewed. The differential expression of the kynurenine pathway in cells within the brain, including inflammatory cells, is explored given the increasing recognition of the importance of inflammation in neurodegenerative disease. An overview of common mechanisms of neurodegeneration is presented before a review and discussion of the evidence for a pathogenetic role of the kynurenine pathway in Alzheimer's disease, HIV-associated neurocognitive disorder, Huntington's disease, motor neurone disease, and Parkinson's disease.
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Affiliation(s)
- Nicholas W.S. Davies
- Department of Neurology, and
- St Vincent’s Centre for Applied Medical Research, St Vincent’s Hospital, Darlinghurst, Sydney, Australia
| | - Gilles Guillemin
- St Vincent’s Centre for Applied Medical Research, St Vincent’s Hospital, Darlinghurst, Sydney, Australia
| | - Bruce J. Brew
- Department of Neurology, and
- St Vincent’s Centre for Applied Medical Research, St Vincent’s Hospital, Darlinghurst, Sydney, Australia
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Kincses ZT, Vecsei L. Pharmacological therapy in Parkinson's disease: focus on neuroprotection. CNS Neurosci Ther 2010; 17:345-67. [PMID: 20438581 DOI: 10.1111/j.1755-5949.2010.00150.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Although the number of available therapeutic approaches in Parkinson's disease (PD) is steadily increasing the search for effective neuroprotective agent is continuing. Such research is directed at influencing the key steps in the pathomechanism: the mitochondrial dysfunction, the oxidative stress, the neuroinflammatory processes and the final common apoptotic pathway. Earlier-developed symptomatic therapies were implicated to be neuroprotective, and promising novel disease modifying approaches were brought into the focus of interest. The current review presents a survey of our current knowledge relating to the pathomechanism of PD and discusses the putative neuroprotective therapy.
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Affiliation(s)
- Zsigmond Tamas Kincses
- Department of Neurology, Albert Szent-Györgyi Clinical Center, University of Szeged, Szeged, Hungary
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Schwarcz R, Guidetti P, Sathyasaikumar KV, Muchowski PJ. Of mice, rats and men: Revisiting the quinolinic acid hypothesis of Huntington's disease. Prog Neurobiol 2010; 90:230-45. [PMID: 19394403 PMCID: PMC2829333 DOI: 10.1016/j.pneurobio.2009.04.005] [Citation(s) in RCA: 130] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2009] [Accepted: 04/17/2009] [Indexed: 12/31/2022]
Abstract
The neurodegenerative disease Huntington's disease (HD) is caused by an expanded polyglutamine (polyQ) tract in the protein huntingtin (htt). Although the gene encoding htt was identified and cloned more than 15 years ago, and in spite of impressive efforts to unravel the mechanism(s) by which mutant htt induces nerve cell death, these studies have so far not led to a good understanding of pathophysiology or an effective therapy. Set against a historical background, we review data supporting the idea that metabolites of the kynurenine pathway (KP) of tryptophan degradation provide a critical link between mutant htt and the pathophysiology of HD. New studies in HD brain and genetic model organisms suggest that the disease may in fact be causally related to early abnormalities in KP metabolism, favoring the formation of two neurotoxic metabolites, 3-hydroxykynurenine and quinolinic acid, over the related neuroprotective agent kynurenic acid. These findings not only link the excitotoxic hypothesis of HD pathology to an impairment of the KP but also define new drug targets and therefore have direct therapeutic implications. Thus, pharmacological normalization of the imbalance in brain KP metabolism may provide clinical benefits, which could be especially effective in early stages of the disease.
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Affiliation(s)
- Robert Schwarcz
- Maryland Psychiatric Research Center, University of Maryland School of Medicine, Baltimore, MD, USA.
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Forrest CM, Mackay GM, Stoy N, Spiden SL, Taylor R, Stone TW, Darlington LG. Blood levels of kynurenines, interleukin-23 and soluble human leucocyte antigen-G at different stages of Huntington's disease. J Neurochem 2009; 112:112-22. [PMID: 19845828 DOI: 10.1111/j.1471-4159.2009.06442.x] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
There is substantial evidence that abnormal concentrations of oxidised tryptophan metabolites, produced via the kynurenine pathway, contribute to progressive neurodegeneration in Huntington's disease. We have now examined the blood levels of these metabolites in patients at different stages of Huntington's disease, assessed both in terms of clinical disease severity and numbers of CAG repeats. Close relatives of the patients were included in the study as well as unrelated healthy controls. Levels of lipid peroxidation products, the pro-inflammatory cytokine interleukin (IL)-23 and the soluble human leucocyte antigen-G (sHLA-G) were also measured. There were lower levels of tryptophan and a higher kynurenine : tryptophan ratio, indicating activation of indoleamine-2,3-dioxygenase, in the most severely affected group of patients, with increased levels of IL-23 and sHLA-G. Marked correlations were noted between IL-23 and the patient severity group, anthranilic acid levels and the number of CAG repeats, and between anthranilic acid and IL-23, supporting our previous evidence of a relationship between anthranilic acid and inflammatory status. Tryptophan was negatively correlated with symptom severity and number of CAG repeats, and positively correlated with sHLA-G. The results support the proposal that tryptophan metabolism along the kynurenine pathway in Huntington's disease is related to the degree of genetic abnormality, to clinical disease severity and to aspects of immunopathogenesis.
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Affiliation(s)
- Caroline M Forrest
- Faculty of Biomedical & Life Sciences, Neuroscience and Molecular Pharmacology, University of Glasgow, Glasgow, UK
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Bethea CL, Reddy AP, Tokuyama Y, Henderson JA, Lima FB. Protective actions of ovarian hormones in the serotonin system of macaques. Front Neuroendocrinol 2009; 30:212-38. [PMID: 19394356 PMCID: PMC2704571 DOI: 10.1016/j.yfrne.2009.04.003] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/10/2009] [Revised: 04/14/2009] [Accepted: 04/15/2009] [Indexed: 12/19/2022]
Abstract
The serotonin neurons of the dorsal and medial raphe nuclei project to all areas of the forebrain and play a key role in mood disorders. Hence, any loss or degeneration of serotonin neurons could have profound ramifications. In a monkey model of surgical menopause with hormone replacement and no neural injury, E and P decreased gene expression in the dorsal raphe nucleus of c-jun n-terminal kinase (JNK1) and kynurenine mono-oxygenase (KMO) that promote cell death. In concert, E and P increased gene expression of superoxide dismutase (SOD1), VEGF, and caspase inhibitory proteins that promote cellular resilience in the dorsal raphe nucleus. Subsequently, we showed that ovarian steroids inhibit pivotal genes in the caspase-dependent and caspase-independent pathways in laser-captured serotonin neurons including apoptosis activating factor (Apaf1), apoptosis-inducing factor (AIF) and second mitochondria-derived activator of caspases (Smac/Diablo). SOD1 was also increased specifically in laser-captured serotonin neurons. Examination of protein expression in the dorsal raphe block revealed that JNK1, phosphoJNK1, AIF and the translocation of AIF from the mitochondria to the nucleus decreased with hormone therapy, whereas pivotal execution proteins in the caspase pathway were unchanged. In addition, cyclins A, B, D1 and E were inhibited, which would prevent re-entry into the cell cycle and catastrophic death. These data indicated that in the absence of gross injury to the midbrain, ovarian steroids inhibit the caspase-independent pathway and cell cycle initiation in serotonin neurons. To determine if these molecular actions prevented cellular vulnerability or death, we examined DNA fragmentation in the dorsal raphe nucleus with the TUNEL assay (terminal deoxynucleotidyl transferase nick end labeling). Ovarian steroids significantly decreased the number of TUNEL-positive cells in the dorsal raphe. Moreover, TUNEL staining prominently colocalized with TPH immunostaining, a marker for serotonin neurons. In summary, ovarian steroids increase the cellular resilience of serotonin neurons and may prevent serotonin neuron death in women facing decades of life after menopause. The survival of serotonin neurons would support cognition and mental health.
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Affiliation(s)
- Cynthia L Bethea
- Divisions of Reproductive Sciences, Oregon National Primate Research Center, Beaverton, OR 97006, United States.
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Rodgers J, Stone TW, Barrett MP, Bradley B, Kennedy PGE. Kynurenine pathway inhibition reduces central nervous system inflammation in a model of human African trypanosomiasis. Brain 2009; 132:1259-67. [PMID: 19339256 PMCID: PMC2677800 DOI: 10.1093/brain/awp074] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2008] [Revised: 02/13/2009] [Accepted: 02/28/2009] [Indexed: 11/13/2022] Open
Abstract
Human African trypanosomiasis, or sleeping sickness, is caused by the protozoan parasites Trypanosoma brucei rhodesiense or Trypanosoma brucei gambiense, and is a major cause of systemic and neurological disability throughout sub-Saharan Africa. Following early-stage disease, the trypanosomes cross the blood-brain barrier to invade the central nervous system leading to the encephalitic, or late stage, infection. Treatment of human African trypanosomiasis currently relies on a limited number of highly toxic drugs, but untreated, is invariably fatal. Melarsoprol, a trivalent arsenical, is the only drug that can be used to cure both forms of the infection once the central nervous system has become involved, but unfortunately, this drug induces an extremely severe post-treatment reactive encephalopathy (PTRE) in up to 10% of treated patients, half of whom die from this complication. Since it is unlikely that any new and less toxic drug will be developed for treatment of human African trypanosomiasis in the near future, increasing attention is now being focussed on the potential use of existing compounds, either alone or in combination chemotherapy, for improved efficacy and safety. The kynurenine pathway is the major pathway in the metabolism of tryptophan. A number of the catabolites produced along this pathway show neurotoxic or neuroprotective activities, and their role in the generation of central nervous system inflammation is well documented. In the current study, Ro-61-8048, a high affinity kynurenine-3-monooxygenase inhibitor, was used to determine the effect of manipulating the kynurenine pathway in a highly reproducible mouse model of human African trypanosomiasis. It was found that Ro-61-8048 treatment had no significant effect (P = 0.4445) on the severity of the neuroinflammatory pathology in mice during the early central nervous system stage of the disease when only a low level of inflammation was present. However, a significant (P = 0.0284) reduction in the severity of the neuroinflammatory response was detected when the inhibitor was administered in animals exhibiting the more severe, late central nervous system stage, of the infection. In vitro assays showed that Ro-61-8048 had no direct effect on trypanosome proliferation suggesting that the anti-inflammatory action is due to a direct effect of the inhibitor on the host cells and not a secondary response to parasite destruction. These findings demonstrate that kynurenine pathway catabolites are involved in the generation of the more severe inflammatory reaction associated with the late central nervous system stages of the disease and suggest that Ro-61-8048 or a similar drug may prove to be beneficial in preventing or ameliorating the PTRE when administered as an adjunct to conventional trypanocidal chemotherapy.
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Affiliation(s)
- Jean Rodgers
- Division of Clinical Neurosciences, Faculty of Medicine, University of Glasgow, Institute of Neurological Sciences, Southern General Hospital, Glasgow G41 4TF, UK
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Elevated levels of kynurenic acid change the dopaminergic response to amphetamine: implications for schizophrenia. Int J Neuropsychopharmacol 2009; 12:501-12. [PMID: 18796185 DOI: 10.1017/s1461145708009383] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Kynurenic acid (KYNA) is an endogenous compound implicated in the pathophysiology of schizophrenia. This tryptophan metabolite antagonizes both the N-methyl-D-aspartate (NMDA) receptors and the nicotinic alpha7* receptors at micromolar concentrations. In the present study the effects of amphetamine on dopamine (DA) release in the nucleus accumbens and on firing of DA neurons in the ventral tegmental area (VTA) were investigated in rats treated with kynurenine, the precursor of KYNA, in order to elevate brain KYNA levels. In rats subchronically treated with kynurenine (90 mg/kg x d for 6 d via osmotic minipumps, resulting in a 2-fold increase in whole-brain KYNA), the amphetamine-induced (2 mg/kg i.p.) increase in accumbal DA release was clearly enhanced compared to controls. Furthermore, subchronic treatment with kynurenine reduced the inhibitory action of amphetamine (0.2-25.6 mg/kg i.v.) on firing rate and burst firing activity of VTA DA neurons. A single dose of kynurenine (5 mg/kg s.c., 60 min, resulting in a 3-fold increase in whole-brain KYNA) did not alter the amphetamine-induced effects on DA neurotransmission compared to control rats. Present data are in agreement with the increased striatal DA release by amphetamine as observed by brain-imaging studies in patients with schizophrenia. Thus, subchronic elevation of rat brain KYNA, may rationally serve as an animal model similar to a pathophysiological condition of schizophrenia. It is proposed that the reduced responsivity of VTA DA neurons to the inhibitory action of amphetamine observed in rats with subchronically elevated KYNA levels may partly account for the increase in terminal DA release.
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Smith AJ, Smith RA, Stone TW. 5-Hydroxyanthranilic Acid, a Tryptophan Metabolite, Generates Oxidative Stress and Neuronal Death via p38 Activation in Cultured Cerebellar Granule Neurones. Neurotox Res 2009; 15:303-10. [DOI: 10.1007/s12640-009-9034-0] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2008] [Revised: 01/13/2009] [Accepted: 01/13/2009] [Indexed: 10/20/2022]
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Van Gool AR, Verkerk R, Fekkes D, Bannink M, Sleijfer S, Kruit WHJ, van der Holt B, Scharpé S, Eggermont AMM, Stoter G, Hengeveld MW. Neurotoxic and neuroprotective metabolites of kynurenine in patients with renal cell carcinoma treated with interferon-alpha: course and relationship with psychiatric status. Psychiatry Clin Neurosci 2008; 62:597-602. [PMID: 18950381 DOI: 10.1111/j.1440-1819.2008.01854.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
AIMS Immunotherapy with interferon-alpha (IFN-alpha) is associated with psychiatric side-effects, including depression. One of the putative pathways underlying these psychiatric side-effects involves tryptophan (TRP) metabolism. Cytokines including IFN-alpha induce the enzyme indoleamine 2,3-dioxygenase (IDO), which converts TRP to kynurenine (KYN), leading to a shortage of serotonin (5-HT). In addition, the production of neurotoxic metabolites of KYN such as 3-hydroxykynurenine and quinolinic acid (QA) might increase and contribute to IFN-alpha-induced psychopathology. In contrast, other catabolites of KYN, such as kynurenic acid (KA), are thought to have neuroprotective properties. METHODS In a group of 24 patients treated with standard IFN-alpha for metastatic renal cell carcinoma (RCC), combined psychiatric and laboratory assessments were performed at baseline, 4 and 8 weeks, and at 6 months. RESULTS No psychopathology was observed, despite an increase in neurotoxic challenge as reflected in indices for the balance between neurotoxic and neuroprotective metabolites of KYN. CONCLUSIONS The present hypothesis that a shift in the balance between neurotoxic and neuroprotective metabolites of KYN underlies the neuropsychiatric side-effects of IFN-alpha-based immunotherapy, is neither supported nor rejected.
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Affiliation(s)
- Arthur R Van Gool
- Department of Psychiatry, Erasmus MC, Daniel den Hoed Cancer Center, Rotterdam, The Netherlands.
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Ting KK, Brew B, Guillemin G. The involvement of astrocytes and kynurenine pathway in Alzheimer's disease. Neurotox Res 2008; 12:247-62. [PMID: 18201952 DOI: 10.1007/bf03033908] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The kynurenine pathway (KP) and several of its neuroactive products, especially quinolinic acid (QUIN), are considered to be involved in the neuropathogenesis of Alzheimer's disease (AD). There is growing evidence suggesting that astrocytes play a critical role in the regulation of the excitotoxicity and inflammatory processes that occur during the evolution of AD. This review focuses on the role of astrocytes through their relation with the KP to the different features associated with AD including cytokine, chemokine and adhesion molecule production, cytoskeletal changes, astrogliosis, excitotoxicity, apoptosis and neurodegeneration.
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Affiliation(s)
- Ka Ka Ting
- Centre for Immunology, St. Vincent's Hospital, Darlinghurst 2010, Sydney, NSW, Australia
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