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Pamart G, Gosset P, Le Rouzic O, Pichavant M, Poulain-Godefroy O. Kynurenine Pathway in Respiratory Diseases. Int J Tryptophan Res 2024; 17:11786469241232871. [PMID: 38495475 PMCID: PMC10943758 DOI: 10.1177/11786469241232871] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Accepted: 01/28/2024] [Indexed: 03/19/2024] Open
Abstract
The kynurenine pathway is the primary route for tryptophan catabolism and has received increasing attention as its association with inflammation and the immune system has become more apparent. This review provides a broad overview of the kynurenine pathway in respiratory diseases, from the initial observations to the characterization of the different cell types involved in the synthesis of kynurenine metabolites and the underlying immunoregulatory mechanisms. With a focus on respiratory infections, the various attempts to characterize the kynurenine/tryptophan (K/T) ratio as an inflammatory marker are reviewed. Its implication in chronic lung inflammation and its exacerbation by respiratory pathogens is also discussed. The emergence of preclinical interventional studies targeting the kynurenine pathway opens the way for the future development of new therapies.
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Affiliation(s)
- Guillaume Pamart
- Univ. Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019 - UMR 9017 -CIIL - Center for Infection and Immunity of Lille, Lille, France
| | - Philippe Gosset
- Univ. Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019 - UMR 9017 -CIIL - Center for Infection and Immunity of Lille, Lille, France
| | - Olivier Le Rouzic
- Univ. Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019 - UMR 9017 -CIIL - Center for Infection and Immunity of Lille, Lille, France
| | - Muriel Pichavant
- Univ. Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019 - UMR 9017 -CIIL - Center for Infection and Immunity of Lille, Lille, France
| | - Odile Poulain-Godefroy
- Univ. Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019 - UMR 9017 -CIIL - Center for Infection and Immunity of Lille, Lille, France
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2
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Badawy AAB, Guillemin GJ. Species Differences in Tryptophan Metabolism and Disposition. Int J Tryptophan Res 2022; 15:11786469221122511. [PMID: 36325027 PMCID: PMC9620070 DOI: 10.1177/11786469221122511] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Accepted: 07/20/2022] [Indexed: 11/06/2022] Open
Abstract
Major species differences in tryptophan (Trp) metabolism and disposition exist
with important physiological, functional and toxicity implications. Unlike
mammalian and other species in which plasma Trp exists largely bound to albumin,
teleosts and other aquatic species possess little or no albumin, such that Trp
entry into their tissues is not hampered, neither is that of environmental
chemicals and toxins, hence the need for strict measures to safeguard their
aquatic environments. In species sensitive to toxicity of excess Trp, hepatic
Trp 2,3-dioxygenase (TDO) lacks the free apoenzyme and its glucocorticoid
induction mechanism. These species, which are largely herbivorous, however,
dispose of Trp more rapidly and their TDO is activated by smaller doses of Trp
than Trp-tolerant species. In general, sensitive species may possess a higher
indoleamine 2,3-dioxygenase (IDO) activity which equips them to resist immune
insults up to a point. Of the enzymes of the kynurenine pathway beyond TDO and
IDO, 2-amino-3-carboxymuconic acid-6-semialdehyde decarboxylase (ACMSD)
determines the extent of progress of the pathway towards NAD+
synthesis and its activity varies across species, with the domestic cat
(Felis catus) being the leading species possessing the
highest activity, hence its inability to utilise Trp for NAD+
synthesis. The paucity of current knowledge of Trp metabolism and disposition in
wild carnivores, invertebrates and many other animal species described here
underscores the need for further studies of the physiology of these species and
its interaction with Trp metabolism.
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Affiliation(s)
- Abdulla A-B Badawy
- Formerly School of Health Sciences,
Cardiff Metropolitan University, Cardiff, Wales, UK,Abdulla A-B Badawy, Formerly School of
Health Sciences, Cardiff Metropolitan University, Western Avenue, Cardiff,
Wales, CF5 2YB, UK.
| | - Gilles J Guillemin
- Neuroinflammation Group, MND Research
Centre, Macquarie Medical School, Macquarie University, NSW, Australia
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3
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Coppens V, Verkerk R, Morrens M. Tracking TRYCAT: A Critical Appraisal of Kynurenine Pathway Quantifications in Blood. Front Pharmacol 2022; 13:825948. [PMID: 35250576 PMCID: PMC8892384 DOI: 10.3389/fphar.2022.825948] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Accepted: 01/19/2022] [Indexed: 12/24/2022] Open
Affiliation(s)
- Violette Coppens
- Faculty of Medicine and Health Sciences, Collaborative Antwerp Psychiatric Research Institute (CAPRI), University of Antwerp, Antwerp, Belgium.,Scientific Initiative of Neuropsychiatric and Psychopharmacological Studies (SINAPS), University Psychiatric Centre Duffel, Duffel, Belgium
| | - Robert Verkerk
- Laboratory of Medical Biochemistry, University of Antwerp, Antwerp, Belgium
| | - Manuel Morrens
- Faculty of Medicine and Health Sciences, Collaborative Antwerp Psychiatric Research Institute (CAPRI), University of Antwerp, Antwerp, Belgium.,Scientific Initiative of Neuropsychiatric and Psychopharmacological Studies (SINAPS), University Psychiatric Centre Duffel, Duffel, Belgium
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4
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Sathyasaikumar KV, Pérez de la Cruz V, Pineda B, Vázquez Cervantes GI, Ramírez Ortega D, Donley DW, Severson PL, West BL, Giorgini F, Fox JH, Schwarcz R. Cellular Localization of Kynurenine 3-Monooxygenase in the Brain: Challenging the Dogma. Antioxidants (Basel) 2022; 11:antiox11020315. [PMID: 35204197 PMCID: PMC8868204 DOI: 10.3390/antiox11020315] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Revised: 01/31/2022] [Accepted: 02/02/2022] [Indexed: 02/07/2023] Open
Abstract
Kynurenine 3-monooxygenase (KMO), a key player in the kynurenine pathway (KP) of tryptophan degradation, regulates the synthesis of the neuroactive metabolites 3-hydroxykynurenine (3-HK) and kynurenic acid (KYNA). KMO activity has been implicated in several major brain diseases including Huntington’s disease (HD) and schizophrenia. In the brain, KMO is widely believed to be predominantly localized in microglial cells, but verification in vivo has not been provided so far. Here, we examined KP metabolism in the brain after depleting microglial cells pharmacologically with the colony stimulating factor 1 receptor inhibitor PLX5622. Young adult mice were fed PLX5622 for 21 days and were euthanized either on the next day or after receiving normal chow for an additional 21 days. Expression of microglial marker genes was dramatically reduced on day 22 but had fully recovered by day 43. In both groups, PLX5622 treatment failed to affect Kmo expression, KMO activity or tissue levels of 3-HK and KYNA in the brain. In a parallel experiment, PLX5622 treatment also did not reduce KMO activity, 3-HK and KYNA in the brain of R6/2 mice (a model of HD with activated microglia). Finally, using freshly isolated mouse cells ex vivo, we found KMO only in microglia and neurons but not in astrocytes. Taken together, these data unexpectedly revealed that neurons contain a large proportion of functional KMO in the adult mouse brain under both physiological and pathological conditions.
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Affiliation(s)
- Korrapati V. Sathyasaikumar
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD 21228, USA;
| | - Verónica Pérez de la Cruz
- Neurobiochemistry and Behavior Laboratory, National Institute of Neurology and Neurosurgery “Manuel Velasco Suárez”, Mexico City 14269, Mexico; (V.P.d.l.C.); (G.I.V.C.); (D.R.O.)
| | - Benjamín Pineda
- Neuroimmunology Department, National Institute of Neurology and Neurosurgery “Manuel Velasco Suárez”, Mexico City 14269, Mexico;
| | - Gustavo Ignacio Vázquez Cervantes
- Neurobiochemistry and Behavior Laboratory, National Institute of Neurology and Neurosurgery “Manuel Velasco Suárez”, Mexico City 14269, Mexico; (V.P.d.l.C.); (G.I.V.C.); (D.R.O.)
| | - Daniela Ramírez Ortega
- Neurobiochemistry and Behavior Laboratory, National Institute of Neurology and Neurosurgery “Manuel Velasco Suárez”, Mexico City 14269, Mexico; (V.P.d.l.C.); (G.I.V.C.); (D.R.O.)
| | - David W. Donley
- Department of Veterinary Sciences, University of Wyoming, Laramie, WY 82071, USA; (D.W.D.); (J.H.F.)
| | - Paul L. Severson
- Plexxikon Inc., South San Francisco, CA 94080, USA; (P.L.S.); (B.L.W.)
| | - Brian L. West
- Plexxikon Inc., South San Francisco, CA 94080, USA; (P.L.S.); (B.L.W.)
| | - Flaviano Giorgini
- Department of Genetics and Genome Biology, University of Leicester, Leicester LE1 7JA, UK;
| | - Jonathan H. Fox
- Department of Veterinary Sciences, University of Wyoming, Laramie, WY 82071, USA; (D.W.D.); (J.H.F.)
| | - Robert Schwarcz
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD 21228, USA;
- Correspondence: ; Tel.: +1-410-402-7635
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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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Skorobogatov K, De Picker L, Verkerk R, Coppens V, Leboyer M, Müller N, Morrens M. Brain Versus Blood: A Systematic Review on the Concordance Between Peripheral and Central Kynurenine Pathway Measures in Psychiatric Disorders. Front Immunol 2021; 12:716980. [PMID: 34630391 PMCID: PMC8495160 DOI: 10.3389/fimmu.2021.716980] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2021] [Accepted: 09/08/2021] [Indexed: 12/19/2022] Open
Abstract
Objective Disturbances in the kynurenine pathway have been implicated in the pathophysiology of psychotic and mood disorders, as well as several other psychiatric illnesses. It remains uncertain however to what extent metabolite levels detectable in plasma or serum reflect brain kynurenine metabolism and other disease-specific pathophysiological changes. The primary objective of this systematic review was to investigate the concordance between peripheral and central (CSF or brain tissue) kynurenine metabolites. As secondary aims we describe their correlation with illness course, treatment response, and neuroanatomical abnormalities in psychiatric diseases. Methods We performed a systematic literature search until February 2021 in PubMed. We included 27 original research articles describing a correlation between peripheral and central kynurenine metabolite measures in preclinical studies and human samples from patients suffering from neuropsychiatric disorders and other conditions. We also included 32 articles reporting associations between peripheral KP markers and symptom severity, CNS pathology or treatment response in schizophrenia, bipolar disorder or major depressive disorder. Results For kynurenine and 3-hydroxykynurenine, moderate to strong concordance was found between peripheral and central concentrations not only in psychiatric disorders, but also in other (patho)physiological conditions. Despite discordant findings for other metabolites (mainly tryptophan and kynurenic acid), blood metabolite levels were associated with clinical symptoms and treatment response in psychiatric patients, as well as with observed neuroanatomical abnormalities and glial activity. Conclusion Only kynurenine and 3-hydroxykynurenine demonstrated a consistent and reliable concordance between peripheral and central measures. Evidence from psychiatric studies on kynurenine pathway concordance is scarce, and more research is needed to determine the validity of peripheral kynurenine metabolite assessment as proxy markers for CNS processes. Peripheral kynurenine and 3-hydroxykynurenine may nonetheless represent valuable predictive and prognostic biomarker candidates for psychiatric disorders.
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Affiliation(s)
- Katrien Skorobogatov
- Faculty of Medicine and Health Sciences, Collaborative Antwerp Psychiatric Research Institute (CAPRI), University of Antwerp, Antwerp, Belgium.,Scientific Initiative of Neuropsychiatric and Psychopharmacological Studies (SINAPS), University Psychiatric Centre Duffel, Duffel, Belgium
| | - Livia De Picker
- Faculty of Medicine and Health Sciences, Collaborative Antwerp Psychiatric Research Institute (CAPRI), University of Antwerp, Antwerp, Belgium.,Scientific Initiative of Neuropsychiatric and Psychopharmacological Studies (SINAPS), University Psychiatric Centre Duffel, Duffel, Belgium
| | - Robert Verkerk
- Laboratory of Medical Biochemistry, University of Antwerp, Antwerp, Belgium
| | - Violette Coppens
- Faculty of Medicine and Health Sciences, Collaborative Antwerp Psychiatric Research Institute (CAPRI), University of Antwerp, Antwerp, Belgium.,Scientific Initiative of Neuropsychiatric and Psychopharmacological Studies (SINAPS), University Psychiatric Centre Duffel, Duffel, Belgium
| | - Marion Leboyer
- INSERM U955, Equipe Psychiatrie Translationnelle, Créteil, France.,Fondation FondaMental - Hôpital Albert Chenevier - Pôle Psychiatrie, Créteil, France.,AP-HP, Hôpitaux Universitaires Henri Mondor, DHU Pepsy, Pôle de Psychiatrie et d'Addictologie, Créteil, France.,Université Paris Est Créteil, Faculté de Médecine, Creteil, France
| | - Norbert Müller
- Department of Psychiatry and Psychotherapy, Ludwig-Maximilians-University, München, Germany
| | - Manuel Morrens
- Faculty of Medicine and Health Sciences, Collaborative Antwerp Psychiatric Research Institute (CAPRI), University of Antwerp, Antwerp, Belgium.,Scientific Initiative of Neuropsychiatric and Psychopharmacological Studies (SINAPS), University Psychiatric Centre Duffel, Duffel, Belgium
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7
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Al-Karagholi MAM, Hansen JM, Abou-Kassem D, Hansted AK, Ubhayasekera K, Bergquist J, Vécsei L, Jansen-Olesen I, Ashina M. Phase 1 study to access safety, tolerability, pharmacokinetics, and pharmacodynamics of kynurenine in healthy volunteers. Pharmacol Res Perspect 2021; 9:e00741. [PMID: 33682377 PMCID: PMC7937944 DOI: 10.1002/prp2.741] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Revised: 12/16/2020] [Accepted: 01/17/2021] [Indexed: 01/13/2023] Open
Abstract
The kynurenine pathway (KP) is the main path for tryptophan metabolism, and it represents a multitude of potential sites for drug discovery in neuroscience, including pain, stroke, and epilepsy. L‐kynurenine (LKYN), the first active metabolite in the pathway, emerges to be a prodrug targeting glutamate receptors. The safety, tolerability, pharmacokinetics, and pharmacodynamics of LKYN in humans have not been previously investigated. In an open‐label, single ascending dose study, six participants received an intravenous infusion of 50, 100, and 150 µg/kg LKYN and new six participants received an intravenous infusion of 0.3, 0.5, 1, and 5 mg/kg LKYN. To compare the pharmacological effects between species, we investigated in vivo the vascular effects of LKYN in rats. In humans, LKYN was safe and well‐tolerated at all dose levels examined. After infusion, LKYN plasma concentration increased significantly over time 3.23 ± 1.12 µg/mL (after 50 µg/kg), 4.04 ± 1.1 µg/mL (after 100 µg/kg), and 5.25 ± 1.01 µg/mL (after 150 µg/kg) (p ≤ 0.001). We observed no vascular changes after infusion compared with baseline. In rats, LKYN had no effect on HR and MAP and caused no dilation of dural and pial arteries. This first‐in‐human study of LKYN showed that LKYN was safe and well‐tolerated after intravenous infusion up to 5 mg/kg over 20 minutes. The lack of change in LKYN metabolites in plasma suggests a relatively slow metabolism of LKYN and no or little feed‐back effect of LKYN on its synthesis. The therapeutic potential of LKYN in stroke and epilepsy should be explored in future studies in humans.
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Affiliation(s)
| | - Jakob Møller Hansen
- Danish Headache Center, Department of Neurology, University of Copenhagen, Denmark.,Danish Knowledge Center on Headache Disorders, Rigshospitalet-Glostrup, Denmark
| | - Dalia Abou-Kassem
- Danish Headache Center, Department of Neurology, University of Copenhagen, Denmark
| | - Anna Koldbro Hansted
- Danish Headache Center, Glostrup Research Institute, Rigshospitalet Glostrup, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark
| | - Kumari Ubhayasekera
- Analytical Chemistry and Neurochemistry, Department of Chemistry - BMC, Uppsala University, Sweden
| | - Jonas Bergquist
- Analytical Chemistry and Neurochemistry, Department of Chemistry - BMC, Uppsala University, Sweden
| | - László Vécsei
- Department of Neurology and MTA-SZTE Neuroscience Research Group, University of Szeged, Szeged, Hungary
| | - Inger Jansen-Olesen
- Danish Headache Center, Glostrup Research Institute, Rigshospitalet Glostrup, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark
| | - Messoud Ashina
- Danish Headache Center, Department of Neurology, University of Copenhagen, Denmark.,Danish Knowledge Center on Headache Disorders, Rigshospitalet-Glostrup, Denmark
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8
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Involvement of Indoleamine-2,3-Dioxygenase and Kynurenine Pathway in Experimental Autoimmune Encephalomyelitis in Mice. Neurochem Res 2020; 45:2959-2977. [PMID: 33040279 DOI: 10.1007/s11064-020-03144-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2020] [Revised: 09/21/2020] [Accepted: 10/05/2020] [Indexed: 02/07/2023]
Abstract
The experimental autoimmune encephalomyelitis (EAE) is a model that mimics multiple sclerosis in rodents. Evidence has suggested that the activation of indoleamine-2,3-dioxygenase (IDO), the rate-limiting enzyme in the kynurenine pathway (KP), plays a crucial role in inflammation-related diseases. The present study aimed to investigate the involvement of the inflammatory process and KP components in a model of EAE in mice. To identify the role of KP in EAE pathogenesis, mice received IDO inhibitor (INCB024360) at a dose of 200 mg/kg (per oral) for 25 days. We demonstrated that IDO inhibitor mitigated the clinical signs of EAE, in parallel with the reduction of cytokine levels (brain, spinal cord, spleen and lymph node) and ionized calcium-binding adaptor protein-1 (Iba-1) gene expression in the central nervous system of EAE mice. Besides, IDO inhibitor causes a significant decrease in the levels of tryptophan, kynurenine and neurotoxic metabolites of KP, such as 3-hydroxykynurenine (3-HK) and quinolinic acid (QUIN) in the prefrontal cortex, hippocampus, spinal cord, spleen and lymph node of EAE mice. The mRNA expression and enzyme activity of IDO and kynurenine 3-monooxygenase (KMO) were also reduced by IDO inhibitor. These findings indicate that the inflammatory process concomitant with the activation of IDO/KP is involved in the pathogenic mechanisms of EAE. The modulation of KP is a promising target for novel pharmacological treatment of MS.
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9
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The Role of the Kynurenine Signaling Pathway in Different Chronic Pain Conditions and Potential Use of Therapeutic Agents. Int J Mol Sci 2020; 21:ijms21176045. [PMID: 32842609 PMCID: PMC7503462 DOI: 10.3390/ijms21176045] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 08/11/2020] [Accepted: 08/19/2020] [Indexed: 12/11/2022] Open
Abstract
Tryptophan (TRP) is an essential, aromatic amino acid catabolized by indoleamine 2,3-dioxygenase (IDO) and tryptophan 2,3-dioxygenase (TDO) enzymes into kynurenine. The IDO enzyme is expressed in peripheral tissues and the central nervous system. Another enzyme of interest in the kynurenine signaling pathway is kynurenine 3-monooxygenase (KMO). The purpose of this review is to discuss the role of TRP and the kynurenine signaling pathway in different chronic pain patients. The IDO-1, IDO-2, and KMO enzymes and the kynurenine metabolite have been shown to be involved in the pathogenesis of neuropathic pain and other painful conditions (migraine, cluster headache, etc.) as well as depressive behavior. We highlighted the analgesic potential of novel agents targeting the enzymes of the kynurenine signaling pathway to explore their efficacy in both future basic science and transitional studies. Upcoming studies conducted on animal models will need to take into consideration the differences in TRP metabolism between human and non-human species. Since chronic painful conditions and depression have common pathophysiological patterns, and the kynurenine signaling pathway is involved in both of them, future clinical studies should aim to have outcomes targeting not only pain, but also functionality, mood changes, and quality of life.
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10
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Titz B, Szostak J, Sewer A, Phillips B, Nury C, Schneider T, Dijon S, Lavrynenko O, Elamin A, Guedj E, Tsin Wong E, Lebrun S, Vuillaume G, Kondylis A, Gubian S, Cano S, Leroy P, Keppler B, Ivanov NV, Vanscheeuwijck P, Martin F, Peitsch MC, Hoeng J. Multi-omics systems toxicology study of mouse lung assessing the effects of aerosols from two heat-not-burn tobacco products and cigarette smoke. Comput Struct Biotechnol J 2020; 18:1056-1073. [PMID: 32419906 PMCID: PMC7218232 DOI: 10.1016/j.csbj.2020.04.011] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2019] [Accepted: 04/19/2020] [Indexed: 12/15/2022] Open
Abstract
Multi-omics systems toxicology study, comprising five omics data modalities. Multi-Omics Factor Analysis and multi-modality functional network interpretation. Cigarettes smoke (CS) induced complex immunoregulatory interactions across molecular layers. Aerosols from two heat-not-burn tobacco products had less impact on lungs than CS.
Cigarette smoke (CS) causes adverse health effects and, for smoker who do not quit, modified risk tobacco products (MRTPs) can be an alternative to reduce the risk of developing smoking-related diseases. Standard toxicological endpoints can lack sensitivity, with systems toxicology approaches yielding broader insights into toxicological mechanisms. In a 6-month systems toxicology study on ApoE−/− mice, we conducted an integrative multi-omics analysis to assess the effects of aerosols from the Carbon Heated Tobacco Product (CHTP) 1.2 and Tobacco Heating System (THS) 2.2—a potential and a candidate MRTP based on the heat-not-burn (HnB) principle—compared with CS at matched nicotine concentrations. Molecular exposure effects in the lungs were measured by mRNA/microRNA transcriptomics, proteomics, metabolomics, and lipidomics. Integrative data analysis included Multi-Omics Factor Analysis and multi-modality functional network interpretation. Across all five data modalities, CS exposure was associated with an increased inflammatory and oxidative stress response, and lipid/surfactant alterations. Upon HnB aerosol exposure these effects were much more limited or absent, with reversal of CS-induced effects upon cessation and switching to CHTP 1.2. Functional network analysis revealed CS-induced complex immunoregulatory interactions across the investigated molecular layers (e.g., itaconate, quinolinate, and miR-146) and highlighted the engagement of the heme–Hmox–bilirubin oxidative stress axis by CS. This work exemplifies how multi-omics approaches can be leveraged within systems toxicology studies and the generated multi-omics data set can facilitate the development of analysis methods and can yield further insights into the effects of toxicological exposures on the lung of mice.
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Key Words
- CHTP, Carbon Heated Tobacco Product
- COPD, chronic obstructive pulmonary disease
- CS, cigarette smoke
- Cigarette smoking
- Inhalation toxicology
- LC, liquid chromatography
- MOFA, Multi-Omics Factor Analysis
- MS, mass spectrometry
- Modified risk tobacco product (MRTP)
- Multi-omics
- PCSF, prize-collecting Steiner forest
- ROS, reactive oxygen species
- Systems toxicology
- THS, Tobacco Heating System
- cMRTP, candidate modified risk tobacco product
- sGCCA, sparse generalized canonical correlation analysis
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Affiliation(s)
- Bjoern Titz
- PMI R&D, Philip Morris Products S.A., Quai Jeanrenaud 5, CH-2000 Neuchâtel, Switzerland
| | - Justyna Szostak
- PMI R&D, Philip Morris Products S.A., Quai Jeanrenaud 5, CH-2000 Neuchâtel, Switzerland
| | - Alain Sewer
- PMI R&D, Philip Morris Products S.A., Quai Jeanrenaud 5, CH-2000 Neuchâtel, Switzerland
| | - Blaine Phillips
- Philip Morris International Research Laboratories Pte. Ltd., Science Park II, Singapore
| | - Catherine Nury
- PMI R&D, Philip Morris Products S.A., Quai Jeanrenaud 5, CH-2000 Neuchâtel, Switzerland
| | - Thomas Schneider
- PMI R&D, Philip Morris Products S.A., Quai Jeanrenaud 5, CH-2000 Neuchâtel, Switzerland
| | - Sophie Dijon
- PMI R&D, Philip Morris Products S.A., Quai Jeanrenaud 5, CH-2000 Neuchâtel, Switzerland
| | - Oksana Lavrynenko
- PMI R&D, Philip Morris Products S.A., Quai Jeanrenaud 5, CH-2000 Neuchâtel, Switzerland
| | - Ashraf Elamin
- PMI R&D, Philip Morris Products S.A., Quai Jeanrenaud 5, CH-2000 Neuchâtel, Switzerland
| | - Emmanuel Guedj
- PMI R&D, Philip Morris Products S.A., Quai Jeanrenaud 5, CH-2000 Neuchâtel, Switzerland
| | - Ee Tsin Wong
- Philip Morris International Research Laboratories Pte. Ltd., Science Park II, Singapore
| | - Stefan Lebrun
- PMI R&D, Philip Morris Products S.A., Quai Jeanrenaud 5, CH-2000 Neuchâtel, Switzerland
| | - Grégory Vuillaume
- PMI R&D, Philip Morris Products S.A., Quai Jeanrenaud 5, CH-2000 Neuchâtel, Switzerland
| | - Athanasios Kondylis
- PMI R&D, Philip Morris Products S.A., Quai Jeanrenaud 5, CH-2000 Neuchâtel, Switzerland
| | - Sylvain Gubian
- PMI R&D, Philip Morris Products S.A., Quai Jeanrenaud 5, CH-2000 Neuchâtel, Switzerland
| | - Stephane Cano
- PMI R&D, Philip Morris Products S.A., Quai Jeanrenaud 5, CH-2000 Neuchâtel, Switzerland
| | - Patrice Leroy
- PMI R&D, Philip Morris Products S.A., Quai Jeanrenaud 5, CH-2000 Neuchâtel, Switzerland
| | | | - Nikolai V Ivanov
- PMI R&D, Philip Morris Products S.A., Quai Jeanrenaud 5, CH-2000 Neuchâtel, Switzerland
| | | | - Florian Martin
- PMI R&D, Philip Morris Products S.A., Quai Jeanrenaud 5, CH-2000 Neuchâtel, Switzerland
| | - Manuel C Peitsch
- PMI R&D, Philip Morris Products S.A., Quai Jeanrenaud 5, CH-2000 Neuchâtel, Switzerland
| | - Julia Hoeng
- PMI R&D, Philip Morris Products S.A., Quai Jeanrenaud 5, CH-2000 Neuchâtel, Switzerland
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Colpo GD, Venna VR, McCullough LD, Teixeira AL. Systematic Review on the Involvement of the Kynurenine Pathway in Stroke: Pre-clinical and Clinical Evidence. Front Neurol 2019; 10:778. [PMID: 31379727 PMCID: PMC6659442 DOI: 10.3389/fneur.2019.00778] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Accepted: 07/03/2019] [Indexed: 12/27/2022] Open
Abstract
Background: Stroke is the second leading cause of death after ischemic heart disease and the third leading cause of disability-adjusted life-years lost worldwide. There is a great need for developing more effective strategies to treat stroke and its resulting impairments. Among several neuroprotective strategies tested so far, the kynurenine pathway (KP) seems to be promising, but the evidence is still sparse. Methods: Here, we performed a systematic review of preclinical and clinical studies evaluating the involvement of KP in stroke. We searched for the keywords: (“kynurenine” or “kynurenic acid” or “quinolinic acid”) AND (“ischemia” or “stroke” or “occlusion) in the electronic databases PubMed, Scopus, and Embase. A total of 1,130 papers was initially retrieved. Results: After careful screening, forty-five studies were included in this systematic review, being 39 pre-clinical and six clinical studies. Despite different experimental models of cerebral ischemia, the results are concordant in implicating the KP in the pathophysiology of stroke. Preclinical evidence also suggests that treatment with kynurenine and KMO inhibitors decrease infarct size and improve behavioral and cognitive outcomes. Few studies have investigated the KP in human stroke, and results are consistent with the experimental findings that the KP is activated after stroke. Conclusion: Well-designed preclinical studies addressing the expression of KP enzymes and metabolites in specific cell types and their potential effects at cellular levels alongside more clinical studies are warranted to confirm the translational potential of this pathway as a pharmacological target for stroke and related complications.
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Affiliation(s)
- Gabriela D Colpo
- Neuropsychiatry Program, Department of Psychiatry and Behavioral Sciences, University of Texas Health Science Center at Houston, Houston, TX, United States
| | - Venugopal R Venna
- BRAINS Lab, Department of Neurology, University of Texas Health Science Center at Houston, Houston, TX, United States
| | - Louise D McCullough
- BRAINS Lab, Department of Neurology, University of Texas Health Science Center at Houston, Houston, TX, United States
| | - Antonio L Teixeira
- Neuropsychiatry Program, Department of Psychiatry and Behavioral Sciences, University of Texas Health Science Center at Houston, Houston, TX, United States
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12
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Badawy AAB. Hypothesis kynurenic and quinolinic acids: The main players of the kynurenine pathway and opponents in inflammatory disease. Med Hypotheses 2018; 118:129-138. [PMID: 30037600 DOI: 10.1016/j.mehy.2018.06.021] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Revised: 05/19/2018] [Accepted: 06/19/2018] [Indexed: 12/22/2022]
Abstract
I hypothesize that the intermediates of the kynurenine (Kyn) pathway (KP) of tryptophan (Trp) degradation kynurenic acid (KA) and quinolinic acid (QA) play opposite roles in inflammatory diseases, with KA being antiinflammatory and QA being immunosuppressant. Darlington et al. have demonstrated a decrease in the ratio of plasma 3-hydroxyanthranilic acid to anthranilic acid ([3-HAA]/[AA]) in many inflammatory conditions and proposed that this decrease either reflects inflammatory disease or is an antiinflammatory response. I argue in favour of the latter possibility and provide evidence that KA is responsible for the decrease in this ratio by increasing AA formation from Kyn through activation of the kynureninase reaction. Immunosuppression has been attributed to some Kyn metabolites tested at concentrations far greater than could occur in microenvironments. So far, only QA has been shown using immunohistochemistry to reach immunosuppressive levels. Future immune studies of the KP should focus on QA as the potentially main microenvironmentally measurable immunosuppressant and should include KA as an antiinflammatory metabolite.
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Affiliation(s)
- Abdulla A-B Badawy
- School of Health Sciences, Cardiff Metropolitan University, Western Avenue, Cardiff CF5 2YB, Wales, UK.
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Feng W, Wang Y, Liu ZQ, Zhang X, Han R, Miao YZ, Qin ZH. Microglia activation contributes to quinolinic acid-induced neuronal excitotoxicity through TNF-α. Apoptosis 2018; 22:696-709. [PMID: 28315174 DOI: 10.1007/s10495-017-1363-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
It has been reported that activation of NF-κB is involved in excitotoxicity; however, it is not fully understood how NF-κB contributes to excitotoxicity. The aim of this study is to investigate if NF-κB contributes to quinolinic acid (QA)-mediated excitotoxicity through activation of microglia. In the cultured primary cortical neurons and microglia BV-2 cells, the effects of QA on cell survival, NF-κB expression and cytokines production were investigated. The effects of BV-2-conditioned medium (BCM) on primary cortical neurons were examined. The effects of pyrrolidine dithiocarbamate (PDTC), an inhibitor of NF-κB, and minocycline (MC), an inhibitor of microglia activation, on QA-induced excitotoxicity were assessed. QA-induced NF-κB activation and TNF-α secretion, and the roles of TNF-α in excitotoxicity were studied. QA at the concentration below 1 mM had no apparent toxic effects on cultured primary neurons or BV-2 cells. However, addition of QA-primed BCM to primary neurons did aggravate QA-induced excitotoxicity. The exacerbation of QA-induced excitotoxicity by BCM was partially ameliorated by inhibiting NF-κB and microglia activation. QA induced activation of NF-κB and upregulation of TNF-α in BV-2 cells. Addition of recombinant TNF-α mimicked QA-induced excitotoxic effects on neurons, and neutralizing TNF-α with specific antibodies partially abolished exacerbation of QA-induced excitotoxicity by BCM. These studies suggested that QA activated microglia and upregulated TNF-α through NF-κB pathway in microglia. The microglia-mediated inflammatory pathway contributed, at least in part, to QA-induced excitotoxicity.
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Affiliation(s)
- Wei Feng
- Department of Pharmacology and Laboratory of Aging and Nervous Diseases (SZS0703), College of Pharmaceutical Science, Soochow University, Suzhou, 215123, China
| | - Yan Wang
- Department of Pharmacology and Laboratory of Aging and Nervous Diseases (SZS0703), College of Pharmaceutical Science, Soochow University, Suzhou, 215123, China
| | - Zi-Qi Liu
- Department of Pharmacology and Laboratory of Aging and Nervous Diseases (SZS0703), College of Pharmaceutical Science, Soochow University, Suzhou, 215123, China
| | - Xuan Zhang
- Department of Pharmacology and Laboratory of Aging and Nervous Diseases (SZS0703), College of Pharmaceutical Science, Soochow University, Suzhou, 215123, China.,Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, 02129, USA
| | - Rong Han
- Department of Pharmacology and Laboratory of Aging and Nervous Diseases (SZS0703), College of Pharmaceutical Science, Soochow University, Suzhou, 215123, China
| | - You-Zhu Miao
- Department of Pharmacology and Laboratory of Aging and Nervous Diseases (SZS0703), College of Pharmaceutical Science, Soochow University, Suzhou, 215123, China
| | - Zheng-Hong Qin
- Department of Pharmacology and Laboratory of Aging and Nervous Diseases (SZS0703), College of Pharmaceutical Science, Soochow University, Suzhou, 215123, China.
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14
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Shen Z, Li X, Bao X, Wang R. Microglia-targeted stem cell therapies for Alzheimer disease: A preclinical data review. J Neurosci Res 2017. [PMID: 28643422 DOI: 10.1002/jnr.24066] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Alzheimer disease (AD) is a severe, life-threatening illness characterized by gradual memory loss. The classic histological features of AD include extracellular formation of β-amyloid plaques (Aβ), intracellular neurofibrillary tangles (NFT), and synaptic loss. Recently, accumulated evidence has confirmed the critical role of microglia in the development and exacerbation of AD. When Aβ forms deposits, microglia quickly respond to restore brain physiology by activating a series of repair mechanisms. However, prolonged microglial activation is considered detrimental and may aggravate AD progression. To date, there are no curative therapies for AD. The advent of stem cell transplantation offers novel strategies to treat AD in animal models. Furthermore, studies have reported that transplanted stem cells might ameliorate AD symptoms by regulating microglial functions, from detrimental to protective. This review focuses on the crucial functions of microglia in AD and examines the reactions of microglia to transplanted stem cells.
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Affiliation(s)
- Zhiwei Shen
- Department of Neurosurgery, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Xueyuan Li
- Department of Neurosurgery, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Xinjie Bao
- Department of Neurosurgery, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Renzhi Wang
- Department of Neurosurgery, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
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15
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Lee JM, Tan V, Lovejoy D, Braidy N, Rowe DB, Brew BJ, Guillemin GJ. Involvement of quinolinic acid in the neuropathogenesis of amyotrophic lateral sclerosis. Neuropharmacology 2017; 112:346-364. [DOI: 10.1016/j.neuropharm.2016.05.011] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2016] [Revised: 05/13/2016] [Accepted: 05/17/2016] [Indexed: 10/21/2022]
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16
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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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17
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Dantzer R. Role of the Kynurenine Metabolism Pathway in Inflammation-Induced Depression: Preclinical Approaches. Curr Top Behav Neurosci 2016; 31:117-138. [PMID: 27225497 DOI: 10.1007/7854_2016_6] [Citation(s) in RCA: 144] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Physically ill patients with chronic inflammation often present with symptoms of depression. Our understanding of the pathophysiology of inflammation-associated depression has benefited from preclinical studies on the mechanisms of sickness and clinical studies on the symptoms of sickness and depression that develop in patients treated with immunotherapy. Sickness behavior develops when the immune system is activated by pathogen- or damage-associated molecular patterns. It is a normal biological response to infection and cell injury. It helps the organism to mobilize its immune and metabolic defenses to fight the danger. Depression emerges on the background of sickness when the inflammatory response is too intense and long lasting or the resolution process is deficient. The transition from sickness to depression is mediated by activation of the kynurenine metabolism pathway that leads to the formation of neurotoxic kynurenine metabolites including quinolinic acid, an agonist of N-methyl-D-aspartate receptors. The neuroimmune processes and molecular factors that have been identified in the studies of inflammation-associated depression represent potential new targets for the development of innovative therapies for the treatment of major depressive disorders.
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Affiliation(s)
- Robert Dantzer
- Department of Symptom Research, The University of Texas, MD Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, TX, 77030, USA.
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18
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Sundaram G, Brew BJ, Jones SP, Adams S, Lim CK, Guillemin GJ. Quinolinic acid toxicity on oligodendroglial cells: relevance for multiple sclerosis and therapeutic strategies. J Neuroinflammation 2014; 11:204. [PMID: 25498310 PMCID: PMC4302518 DOI: 10.1186/s12974-014-0204-5] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2014] [Accepted: 11/17/2014] [Indexed: 11/10/2022] Open
Abstract
The excitotoxin quinolinic acid, a by-product of the kynurenine pathway, is known to be involved in several neurological diseases including multiple sclerosis (MS). Quinolinic acid levels are elevated in experimental autoimmune encephalomyelitis rodents, the widely used animal model of MS. Our group has also found pathophysiological concentrations of quinolinic acid in MS patients. This led us to investigate the effect of quinolinic acid on oligodendrocytes; the main cell type targeted by the autoimmune response in MS. We have examined the kynurenine pathway (KP) profile of two oligodendrocyte cell lines and show that these cells have a limited threshold to catabolize exogenous quinolinic acid. We further propose and demonstrate two strategies to limit quinolinic acid gliotoxicity: 1) by neutralizing quinolinic acid’s effects with anti-quinolinic acid monoclonal antibodies and 2) directly inhibiting quinolinic acid production from activated monocytic cells using specific KP enzyme inhibitors. The outcome of this study provides a new insight into therapeutic strategies for limiting quinolinic acid-induced neurodegeneration, especially in neurological disorders that target oligodendrocytes, such as MS.
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Affiliation(s)
- Gayathri Sundaram
- Applied Neurosciences Program, Peter Duncan Neurosciences Research Unit, St Vincent's Centre for Applied Medical Research, Sydney, Australia. .,School of Medical Sciences, Faculty of Medicine, University of New South Wales, Sydney, Australia.
| | - Bruce J Brew
- Applied Neurosciences Program, Peter Duncan Neurosciences Research Unit, St Vincent's Centre for Applied Medical Research, Sydney, Australia. .,Department of Neurology, St Vincent's Hospital, Sydney, Australia.
| | - Simon P Jones
- Applied Neurosciences Program, Peter Duncan Neurosciences Research Unit, St Vincent's Centre for Applied Medical Research, Sydney, Australia.
| | - Seray Adams
- School of Medical Sciences, Faculty of Medicine, University of New South Wales, Sydney, Australia. .,Neurodegenerative diseases Research Group, Australian School of Advanced Medicine, Faculty of Human Sciences, Macquarie University, Sydney, NSW, 2109, Australia.
| | - Chai K Lim
- Applied Neurosciences Program, Peter Duncan Neurosciences Research Unit, St Vincent's Centre for Applied Medical Research, Sydney, Australia. .,School of Medical Sciences, Faculty of Medicine, University of New South Wales, Sydney, Australia. .,Neurodegenerative diseases Research Group, Australian School of Advanced Medicine, Faculty of Human Sciences, Macquarie University, Sydney, NSW, 2109, Australia.
| | - Gilles J Guillemin
- Applied Neurosciences Program, Peter Duncan Neurosciences Research Unit, St Vincent's Centre for Applied Medical Research, Sydney, Australia. .,School of Medical Sciences, Faculty of Medicine, University of New South Wales, Sydney, Australia. .,Neurodegenerative diseases Research Group, Australian School of Advanced Medicine, Faculty of Human Sciences, Macquarie University, Sydney, NSW, 2109, Australia.
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19
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Effects of methylprednisolone and 4-chloro-3-hydroxyanthranilic acid in experimental spinal cord injury in the guinea pig appear to be mediated by different and potentially complementary mechanisms. Spinal Cord 2014; 52:662-6. [PMID: 25047053 DOI: 10.1038/sc.2014.118] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2014] [Revised: 05/19/2014] [Accepted: 06/06/2014] [Indexed: 11/09/2022]
Abstract
STUDY DESIGN Blinded, placebo-controlled, parallel treatment group studies of the effects of methylprednisolone (MP) or 4-chloro-3-hydroxyanthranilate (4-Cl-3-HAA) on behavioral outcome and quinolinic acid tissue levels from experimental thoracic spinal cord injury in adult guinea pigs. OBJECTIVES To compare the effects of treatment with high-dose MP, a corticosteroid, and 4-Cl-3-HAA, a compound that inhibits synthesis of the neurotoxin quinolinic acid (QUIN) by activated macrophages. To explore the effect of different times of treatment using these two approaches to ameliorating secondary tissue damage. SETTING Laboratory animal studies at the University of North Carolina, Chapel Hill, NC, USA. METHODS Standardized spinal cord injuries were produced in anesthetized guinea pigs, using lateral compression of the spinal cord. Behavioral impairment and recovery were measured by placing and toe-spread responses (motor function), cutaneus trunci muscle reflex receptive field areas and somatosensory-evoked potentials (sensory function). Tissue quinolinic acid levels were measured by gas chromatograph/mass spectrometry. RESULTS The current experiments showed a reduction in delayed loss of motor and sensory function in the guinea pig with MP (150 mg kg(-1), intraperitoneally in split doses between 0.5 and 6 h), but no significant reduction in tissue QUIN. Improved sensory function was seen with a single dose of 60 mg kg(-1) MP intraperitoneally at 5 h after injury, but not at 10 h after injury. A single dose of 4-Cl-3-HAA at 5 h in the guinea pig did not produce the sensory and motor improvements seen in previous studies with 12 days of dosing, beginning at 5 h. CONCLUSION These studies, together with earlier findings, indicate that both drugs can attenuate secondary pathologic damage after SCI, but through separate mechanisms. These are most likely an acute reduction by MP of oxidative processes and reduction by 4-Cl-3-HAA of QUIN synthesis.
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20
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Taguchi A, Niwa M, Hoshi M, Saito K, Masutani T, Hisamatsu K, Kobayashi K, Hatano Y, Tomita H, Hara A. Indoleamine 2,3-dioxygenase 1 is upregulated in activated microglia in mice cerebellum during acute viral encephalitis. Neurosci Lett 2014; 564:120-5. [DOI: 10.1016/j.neulet.2014.01.051] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2013] [Revised: 01/16/2014] [Accepted: 01/24/2014] [Indexed: 11/25/2022]
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21
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Choi BK, Cho JH, Jeong SH, Shin HS, Son SW, Yeo YK, Kang HG. Zearalenone affects immune-related parameters in lymphoid organs and serum of rats vaccinated with porcine parvovirus vaccine. Toxicol Res 2013; 28:279-88. [PMID: 24278621 PMCID: PMC3834426 DOI: 10.5487/tr.2012.28.4.279] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2012] [Revised: 11/30/2012] [Accepted: 12/16/2012] [Indexed: 12/12/2022] Open
Abstract
Rats were administered zearalenone (ZEA) via gavage at dosages of 0, 1, 5, and 30 mg/kg for 36 days. On treatment day 8, inactivated porcine parvovirus vaccine (Vac) was injected intraperitoneally. Antibody production against porcine parvovirus was then measured as a function of ZEA treatment. Compared to the vaccine alone, ZEA treatment, with or without Vac, decreased the serum level of IgG. The level of IgM decreased in all ZEA groups at day 22, but the decrease was sustained only in the medium-dose ZEA group at day 36. The level of IgA was unchanged in the Vac only and ZEA groups at day 22, but was decreased in the 5 mg/kg ZEA plus Vac group compared to the Vac only group at day 36. The level of IgE was decreased by all doses of ZEA at day 22, but was unaffected in ZEA plus Vac groups compared to the Vac only group. The levels of IL-1 in the thymus and spleen; INF-γ in serum; IL-2, IL-6, and IL-10 in the thymus; and IL-10 and IFN-γ in the spleen decreased after ZEA administration. Furthermore, the levels of IL-1β in the spleen and mesenteric lymph node, IL-1β in the thymus, IL-2 in the thymus and spleen, IL-6 in the thymus, IL-10 and IFN-γ in the spleen, and GM-CSF and TNF-α in the thymus decreased after vaccination in rats exposed to ZEA. In conclusion, these results suggest that ZEA exposure via drinking water can cause an immunosuppressive effect by decreasing immunoglobulins in serum and cytokines in lymphoid organs.
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Affiliation(s)
- Byung-Kook Choi
- Toxicology & Residue Chemistry Division, Animal, Plant and Fisheries Quarantine and Inspection Agency, Anyang
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22
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Abstract
L-Tryptophan (L-TRP) is a nutritionally essential amino acid and the kynurenine (KYN) pathway is the major route of L-TRP catabolism. Besides being synthesized for proteins, L-TRP and its metabolites have critical roles for the functions of nervous and immune systems. Many researches show that optimal amounts of L-TRP in diets depend on species, developmental stages, environmental factors and health status. We have shown that KYN pathway-related enzyme activities vary among species, tissue and cell types in physiological conditions. Furthermore, the response of these enzyme activities to systemic and/or central nervous system immune activation and inflammation depends on species and cell types. Thus, it is very important to choose appropriate animal species and cell types in which to evaluate the physiologic and pathologic effects of increased KYN pathway metabolism. We believe that understanding L-TRP metabolism among species and cell types provides a better idea for analysis of human pathological condition.
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Affiliation(s)
- Yuki Murakami
- Human Health Sciences, Graduate School of Medicine and Faculty of Medicine, Kyoto University, 53 Kawahara-cho, Shogoin, Sakyo-Ku, Kyoto, Japan
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Lim CK, Yap MMC, Kent SJ, Gras G, Samah B, Batten JC, De Rose R, Heng B, Brew BJ, Guillemin GJ. Characterization of the kynurenine pathway and quinolinic Acid production in macaque macrophages. Int J Tryptophan Res 2013; 6:7-19. [PMID: 23761975 PMCID: PMC3662399 DOI: 10.4137/ijtr.s11789] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
The kynurenine pathway (KP) and one of its end-products, the excitotoxin quinolinic acid (QUIN), are involved in the pathogenesis of several major neuroinflammatory brain diseases. A relevant animal model to study KP metabolism is now needed to assess whether intervention in this pathway may improve the outcome of such diseases. Humans and macaques share a very similar genetic makeup. In this study, we characterized the KP metabolism in macaque primary macrophages of three different species in comparison to human cells. We found that the KP profiles in simian macrophages were very similar to those in humans when challenged with inflammatory cytokines. Further, we found that macaque macrophages are capable of producing a pathophysiological concentration of QUIN. Our data validate the simian model as a relevant model to study the human cellular KP metabolism in the context of inflammation.
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Affiliation(s)
- Chai K Lim
- Department of Pharmacology, School of Medical Sciences, University of New South Wales, Sydney, Australia. ; MND and Neurodegenerative disease Research Group, Australian School of Advance Medicine, Macquarie University, Australia
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Sävman K, Heyes MP, Svedin P, Karlsson A. Microglia/macrophage-derived inflammatory mediators galectin-3 and quinolinic acid are elevated in cerebrospinal fluid from newborn infants after birth asphyxia. Transl Stroke Res 2012; 4:228-35. [PMID: 23807898 PMCID: PMC3685715 DOI: 10.1007/s12975-012-0216-3] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2012] [Revised: 09/25/2012] [Accepted: 10/02/2012] [Indexed: 01/08/2023]
Abstract
Activation of microglia/macrophages is important in neonatal hypoxic–ischemic (HI) brain injury. Based on experimental studies, we identified macrophage/microglia-derived mediators with potential neurotoxic effects after neonatal HI and examined them in cerebrospinal fluid (CSF) from newborn infants after birth asphyxia. Galectin-3 is a novel inflammatory mediator produced by microglia/macrophages. Galectin-3 is chemotactic for inflammatory cells and activates nicotinamide adenine dinucleotide phosphate (NADPH) oxidase resulting in production and release of reactive oxygen species (ROS). Matrix metalloproteinase-9 (MMP-9) is a tissue-degrading protease expressed by activated microglia in the immature brain after HI. Both galectin-3 and MMP-9 contribute to brain injury in animal models for neonatal HI. Quinolinic acid (QUIN) is a neurotoxic N-methyl-d-aspartate (NMDA) receptor agonist also produced by activated microglia/macrophages. Galectin-3 and MMP-9 were measured by ELISA and QUIN by mass spectrometry. Asphyxiated infants (n = 20) had higher levels of galectin-3 (mean (SEM) 2.64 (0.43) ng/mL) and QUIN (335.42 (58.9) nM) than controls (n = 15) (1.36 (0.46) ng/mL and 116.56 (16.46) nM, respectively), p < 0.05 and p < 0.01. Infants with septic infections (n = 10) did not differ from controls. Asphyxiated infants with abnormal outcome had higher levels of galectin-3 (3.96 (0.67) ng/mL) than those with normal outcome (1.76 (0.32) ng/mL), p = 0.02, and the difference remained significant in the clinically relevant group of infants with moderate encephalopathy. MMP-9 was detected in few infants with no difference between groups. The potentially neurotoxic macrophage/microglia-derived mediators galectin-3 and QUIN are increased in CSF after birth asphyxia and could serve as markers and may contribute to injury.
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Affiliation(s)
- Karin Sävman
- Perinatal Center, Department of Pediatrics, Sahlgrenska Academy, University of Gothenburg, 416 85 Göteborg, Sweden ; Department of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, 416 85 Göteborg, Sweden ; Perinatal Center, The Queen Silvia Children's Hospital, 416 85 Göteborg, Sweden
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25
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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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26
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Yu JT, Lee CH, Yoo KY, Choi JH, Li H, Park OK, Yan B, Hwang IK, Kwon YG, Kim YM, Won MH. Maintenance of anti-inflammatory cytokines and reduction of glial activation in the ischemic hippocampal CA1 region preconditioned with lipopolysaccharide. J Neurol Sci 2010; 296:69-78. [PMID: 20580380 DOI: 10.1016/j.jns.2010.06.004] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2010] [Revised: 05/27/2010] [Accepted: 06/02/2010] [Indexed: 12/31/2022]
Abstract
Lipopolysaccharide (LPS) induces a strong immune response, and pretreatment with low dose of LPS suppresses the production of proinflammatory mediators. In the present study, we investigated the effect of LPS preconditioning on the delayed neuronal death in the gerbil hippocampal CA1 region after 5 min of transient cerebral ischemia. LPS preconditioning showed neuroprotective effects against ischemic damage in the hippocampal CA1 region after ischemic insult: about 92% of neurons in the CA1 region survived in the LPS-treated ischemia group. LPS preconditioning maintained anti-inflammatory cytokines, such as interleukin (IL)-4 and IL-13, in pyramidal neurons in the CA1 region after ischemia/reperfusion. In addition, IL-4 and IL-13 protein levels in the CA1 region of the LPS-treated ischemia group were similar to the vehicle-treated sham group. We found that reactive gliosis was markedly attenuated in the CA1 region of the LPS-treated ischemia group compared to the vehicle-treated ischemia group using immunohistochemistry of glial fibrillary acidic protein for astrocytes, and ionized calcium-binding adapter molecule 1 and isolectin B4 for microglia. These results indicate that LPS preconditioning may provide neuroprotection in the ischemic hippocampal CA1 region via maintenance of anti-inflammatory cytokines and suppression of glial activation.
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Affiliation(s)
- Jia Tian Yu
- Department of Anatomy and Neurobiology, and Institute of Neurodegeneration and Neuroregeneration, College of Medicine, Hallym University, Chuncheon 200-702, Republic of Korea
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Sathyasaikumar KV, Stachowski EK, Amori L, Guidetti P, Muchowski PJ, Schwarcz R. Dysfunctional kynurenine pathway metabolism in the R6/2 mouse model of Huntington's disease. J Neurochem 2010; 113:1416-25. [PMID: 20236387 DOI: 10.1111/j.1471-4159.2010.06675.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Elevated concentrations of neurotoxic metabolites of the kynurenine pathway (KP) of tryptophan degradation may play a causative role in Huntington's disease (HD). The brain levels of one of these compounds, 3-hydroxykynurenine (3-HK), are increased in both HD and several mouse models of the disease. In the present study, we examined this impairment in greater detail using the R6/2 mouse, a well-established animal model of HD. Initially, mutant and age-matched wild-type mice received an intrastriatal injection of (3)H-tryptophan to assess the acute, local de novo production of kynurenine, the immediate bioprecursor of 3-HK, in vivo. No effect of genotype was observed between 4 and 12 weeks of age. In contrast, intrastriatally applied (3)H-kynurenine resulted in significantly increased neosynthesis of (3)H-3-HK, but not other tritiated KP metabolites, in the R6/2 striatum. Subsequent ex vivo studies in striatal, cortical and cerebellar tissue revealed substantial increases in the activity of the biosynthetic enzyme of 3-HK, kynurenine 3-monooxygenase and significant reductions in the activity of its degradative enzyme, kynureninase, in HD mice starting at 4 weeks of age. Decreased kynureninase activity was most evident in the cortex and preceded the increase in kynurenine 3-monooxygenase activity. The activity of other KP enzymes showed no consistent brain abnormalities in the mutant mice. These findings suggest that impairments in its immediate metabolic enzymes jointly account for the abnormally high brain levels of 3-HK in the R6/2 model of HD.
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Affiliation(s)
- Korrapati V Sathyasaikumar
- Maryland Psychiatric Research Center, University of Maryland School of Medicine, Baltimore, MD 21228, USA
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28
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Abstract
Acute and chronic alcohol (ethanol) intake and subsequent withdrawal exert major effects on tryptophan (Trp) metabolism and disposition in human subjects and experimental animals. In rats, activity of the rate-limiting enzyme of Trp degradation, liver Trp pyrrolase (TP), is enhanced by acute, but inhibited after chronic, ethanol administration, then enhanced during withdrawal. These changes lead to alterations in brain serotonin synthesis and turnover mediated by corresponding changes in circulating Trp availability to the brain. A low brain-serotonin concentration characterizes the alcohol-preferring C57BL/6J mouse strain and many alcohol-preferring rat lines. In this mouse strain, liver TP enhancement causes the serotonin decrease. In man, acute ethanol intake inhibits brain serotonin synthesis by activating liver TP. This may explain alcohol-induced depression, aggression and loss of control in susceptible individuals. Chronic alcohol intake in dependent subjects may be associated with liver TP inhibition and a consequent enhancement of brain serotonin synthesis, whereas subsequent withdrawal may induce the opposite effects. The excitotoxic Trp metabolite quinolinate may play a role in the behavioural disturbances of the alcohol-withdrawal syndrome. Some abstinent alcoholics may have a central serotonin deficiency, which they correct by liver TP inhibition through drinking. Further studies of the Trp and serotonin metabolic status in long-term abstinence in general and in relation to personality characteristics, alcoholism typology and genetic factors in particular may yield important information which should facilitate the development of more effective screening, and preventative and therapeutic strategies in this area of mental health.
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Affiliation(s)
- Abdulla A-B Badawy
- Cardiff and Vale NHS Trust, Biomedical Research Laboratory, Whitchurch Hospital, Cardiff CF14 7XB, UK.
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Miura H, Shirokawa T, Isobe K, Ozaki N. Shifting the balance of brain tryptophan metabolism elicited by isolation housing and systemic administration of lipopolysaccharide in mice. Stress 2009; 12:206-14. [PMID: 19006008 DOI: 10.1080/10253890802252442] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
The kynurenine (KYN) pathway, which is initiated by indoleamine 2,3-dioxygenase, is a key tryptophan (TRP) metabolic pathway. It shares TRP mainly with the serotonin (5-HT) pathway. Activation of the KYN pathway by stimulation of the inflammatory response system (IRS) is known to induce depressive symptoms. Thus, we considered that shifting the balance between the KYN and 5-HT systems in the brain to the KYN pathway closely relate to the etiology of depression. In the present study, we investigated the influence of environmental risk factors for depression, such as social isolation and activation of the IRS, on brain TRP metabolism. Male ICR mice (postnatal day 21) were divided into two housing conditions, isolation and group housing, reared for 4 weeks, and then given an intraperitoneal injection of lipopolysaccharide (LPS). We measured the TRP, KYN, and 5-HT levels in the prefrontal cortex, hippocampus, amygdala, and dorsal raphe nuclei. Isolation housing decreased the KYN/5-HT ratio in the amygdala and dorsal raphe nuclei. LPS increased the KYN/5-HT ratio in all regions except the dorsal raphe nuclei. Thus, isolation housing shifted the balance between the KYN and 5-HT pathways to the 5-HT pathway, whereas systemic administration of LPS shifted it to the KYN pathway.
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Affiliation(s)
- Hideki Miura
- Department of Psychiatry, Nagoya University Graduate School of Medicine, Nagoya, Aichi, Japan
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Vamos E, Pardutz A, Klivenyi P, Toldi J, Vecsei L. The role of kynurenines in disorders of the central nervous system: possibilities for neuroprotection. J Neurol Sci 2009; 283:21-7. [PMID: 19268309 DOI: 10.1016/j.jns.2009.02.326] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
The metabolism of tryptophan mostly proceeds through the kynurenine pathway. The biochemical reaction includes both an agonist (quinolinic acid) at the N-methyl-d-aspartate receptor and an antagonist (kynurenic acid). Besides the N-methyl-d-aspartate antagonism, an important feature of kynurenic acid is the blockade of the alpha7-nicotinic acetylcholine receptor and its influence on the alpha-amino-3-hydroxy-5-methylisoxazole-4-proprionic acid receptor. Kynurenic acid has proven to be neuroprotective in several experimental settings. On the other hand, quinolinic acid is a potent neurotoxin with an additional and marked free radical-producing property. In consequence of these various receptor activities, the possible roles of these substances in various neurological disorders have been proposed. Moreover, the possibility of influencing the kynurenine pathway to reduce quinolinic acid and increase the level of kynurenic acid in the brain offers a new target for drug action designed to change the balance, decreasing excitotoxins and enhancing neuroprotectants. This review surveys both the early and the current research in this field, focusing on the possible therapeutic effects of kynurenines.
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Affiliation(s)
- Eniko Vamos
- Department of Neurology, Albert Szent-Györgyi Clinical Centre, University of Szeged, Hungary
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31
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Kynurenine diminishes the ischemia-induced histological and electrophysiological deficits in the rat hippocampus. Neurobiol Dis 2008; 32:302-8. [DOI: 10.1016/j.nbd.2008.07.013] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2008] [Revised: 06/30/2008] [Accepted: 07/25/2008] [Indexed: 11/22/2022] Open
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Aging exacerbates depressive-like behavior in mice in response to activation of the peripheral innate immune system. Neuropsychopharmacology 2008; 33:2341-51. [PMID: 18075491 PMCID: PMC2907915 DOI: 10.1038/sj.npp.1301649] [Citation(s) in RCA: 231] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Exposure to peripheral infections may be permissive to cognitive and behavioral complications in the elderly. We have reported that peripheral stimulation of the innate immune system with lipopolysaccharide (LPS) causes an exaggerated neuroinflammatory response and prolonged sickness behavior in aged BALB/c mice. Because LPS also causes depressive behavior, the purpose of this study was to determine whether aging is associated with an exacerbated depressive-like response. We confirmed that LPS (0.33 mg/kg intraperitoneal) induced a protracted sickness response in aged mice with reductions in locomotor and feeding activities 24 and 48 h postinjection, when young adults had fully recovered. When submitted to the forced swim test 24 h post-LPS, both young adult and aged mice exhibited an increased duration of immobility. However, when submitted to either the forced swim test or the tail suspension test 72 h post-LPS, an increased duration of immobility was evident only in aged mice. This prolonged depressive-like behavior in aged LPS-treated mice was associated with a more pronounced induction of peripheral and brain indoleamine 2,3-dioxygenase and a markedly higher turnover rate of brain serotonin (as measured by the ratio of 5-hydroxy-indoleacetic acid over 5-hydroxy-tryptamine) compared to young adult mice at 24 post-LPS injection. These results provide the first evidence that age-associated reactivity of the brain cytokine system could play a pathophysiological role in the increased prevalence of depression observed in the elderly.
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Induction of indolamine 2,3-dioxygenase and kynurenine 3-monooxygenase in rat brain following a systemic inflammatory challenge: a role for IFN-gamma? Neurosci Lett 2008; 441:29-34. [PMID: 18584961 DOI: 10.1016/j.neulet.2008.06.007] [Citation(s) in RCA: 152] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2008] [Revised: 05/10/2008] [Accepted: 06/04/2008] [Indexed: 12/31/2022]
Abstract
Inflammation-mediated dysregulation of the kynurenine pathway has been implicated as a contributor to a number of major brain disorders. Consequently, we examined the impact of a systemic inflammatory challenge on kynurenine pathway enzyme expression in rat brain. Indoleamine 2,3-dioxygenase (IDO) expression was induced in cortex and hippocampus following systemic lipopolysaccharide (LPS) administration. Whilst IDO expression was paralleled by increased circulating interferon (IFN)-gamma concentrations, IFN-gamma expression in the brain was only modestly altered following LPS administration. In contrast, induction of IDO was associated with increased central tumour necrosis factor (TNF)-alpha and interleukin (IL)-6 expression. Similarly, in cultured glial cells LPS-induced IDO expression was accompanied by increased TNF-alpha and IL-6 expression, whereas IFN-gamma was not detectable. These findings indicate that IFN-gamma is not required for LPS-induced IDO expression in brain. A robust increase in kynurenine-3-monooxygenase (KMO) expression was observed in rat brain 24h post LPS, without any change in kynurenine aminotransferase II (KAT II) expression. In addition, we report that constitutive expression of KAT II is approximately 8-fold higher than KMO in cortex and 20-fold higher in hippocampus. Similarly, in glial cells constitutive expression of KAT II was approximately 16-fold higher than KMO, and expression of KMO but not KAT II was induced by LPS. These data are the first to demonstrate that a systemic inflammatory challenge stimulates KMO expression in brain; a situation that is likely to favour kynurenine metabolism in a neurotoxic direction. However, our observation that expression of KAT II is much higher than KMO in rat brain is likely to counteract potential neurotoxicity that could arise from KMO induction following an acute inflammation.
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Robotka H, Sas K, Ágoston M, Rózsa É, Szénási G, Gigler G, Vécsei L, Toldi J. Neuroprotection achieved in the ischaemic rat cortex with l-kynurenine sulphate. Life Sci 2008; 82:915-9. [DOI: 10.1016/j.lfs.2008.02.014] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2007] [Revised: 01/18/2008] [Accepted: 02/10/2008] [Indexed: 10/22/2022]
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Abstract
The kynurenine pathway is a major route of L-tryptophan catabolism producing neuroactive metabolites implicated in neurodegeneration and immune tolerance. We characterized the kynurenine pathway in human neurons and the human SK-N-SH neuroblastoma cell line and found that the kynurenine pathway enzymes were variably expressed. Picolinic carboxylase was expressed only in primary and some adult neurons but not in SK-N-SH cells. Because of this difference, SK-N-SH cells were able to produce the excitotoxin quinolinic acid, whereas human neurons produced the neuroprotectant picolinic acid. The net result of kynurenine pathway induction in human neurons is therefore predicted to result in neuroprotection, immune regulation, and tumor inhibition, whereas in SK-N-SH cells, it may result in neurotoxicity, immune tolerance, and tumor promotion. This study represents the first comprehensive characterization of the kynurenine pathway in neurons and the first description of the involvement of the kynurenine pathway as a mechanism for controlling both tumor cell neurotoxicity and persistence.
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36
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Guillemin GJ, Brew BJ. Chronic HIV infection leads to an Alzheimer's disease like illness. Involvement of the kynurenine pathway. ACTA ACUST UNITED AC 2007. [DOI: 10.1016/j.ics.2007.07.031] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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37
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Gigler G, Szénási G, Simó A, Lévay G, Hársing LG, Sas K, Vécsei L, Toldi J. Neuroprotective effect of L-kynurenine sulfate administered before focal cerebral ischemia in mice and global cerebral ischemia in gerbils. Eur J Pharmacol 2007; 564:116-22. [PMID: 17407777 DOI: 10.1016/j.ejphar.2007.02.029] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2006] [Revised: 02/06/2007] [Accepted: 02/08/2007] [Indexed: 11/15/2022]
Abstract
Excessive stimulation of N-methyl-D-aspartate (NMDA) receptors during ischemia contributes to apoptotic and excitotoxic nerve cell death. Kynurenic acid is a selective antagonist at the glycine co-agonist site of the NMDA receptor complex at low concentration, and it is a broad-spectrum excitatory amino acid receptor blocker at high concentration. Kynurenic acid provides neuroprotection in animal models of cerebral ischemia only at very high doses as it hardly crosses the blood-brain barrier. The neuroprotective effect of L-kynurenine sulfate, a precursor of kynurenic acid, was therefore studied because L-kynurenine readily crosses the blood-brain barrier. L-kynurenine sulfate was administered 15 min before permanent focal cerebral ischemia produced by electrocoagulation of the distal middle cerebral artery in mice. L-kynurenine sulfate induced a small decrease in the surface area of the brain infarction (10%, P<0.05) at 30 mg/kg i.p., and it caused strong reductions in infarct size (24-25%, P<0.01) at 100 and 300 mg/kg i.p. Treatment of gerbils with L-kynurenine sulfate at 300 mg/kg i.p. 2 h before a 3-min bilateral carotid occlusion decreased (40%, P<0.01) the pyramidal cell loss in the CA1 area of the hippocampus. Furthermore, L-kynurenine sulfate inhibited the ischemia-induced hypermotility (77%, P<0.001), and decreased (50%, P<0.01) the ischemia-induced deterioration of spontaneous alternation, a measure of spatial memory, without altering the rectal temperature. In conclusion, the administration of L-kynurenine can elevate the brain concentration of kynurenic acid to neuroprotective levels, suggesting the potential clinical usefulness of L-kynurenine for the prevention of neuronal loss.
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Affiliation(s)
- Gábor Gigler
- Division of Preclinical Research, EGIS Pharmaceuticals PLC, Budapest, Hungary
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38
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Guillemin GJ, Meininger V, Brew BJ. Implications for the kynurenine pathway and quinolinic acid in amyotrophic lateral sclerosis. NEURODEGENER DIS 2006; 2:166-76. [PMID: 16909022 DOI: 10.1159/000089622] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
The kynurenine pathway (KP) is a major route of L-tryptophan catabolism leading to production of several neurobiologically active molecules. Among them is the excitotoxin quinolinic acid (QUIN) that is known to be involved in the pathogenesis of several major inflammatory neurological diseases. In amyotrophic lateral sclerosis (ALS) degeneration of motor neurons is associated with a chronic and local inflammation (presence of activated microglia and astrocytes). There is emerging evidence that the KP is important in ALS. Recently, we demonstrated that QUIN is significantly increased in serum and CSF of ALS patients. Moreover, most of the factors associated with QUIN toxicity are found in ALS, implying that QUIN may play a substantial role in the neuropathogenesis of ALS. This review details the potential role the KP has in ALS and advances a testable hypothetical model.
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Affiliation(s)
- Gilles J Guillemin
- Centre for Immunology and University of New South Wales, School of Medicine and School of Medical Sciences, Sydney, Australia.
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39
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Bellac CL, Coimbra RS, Christen S, Leib SL. Pneumococcal meningitis causes accumulation of neurotoxic kynurenine metabolites in brain regions prone to injury. Neurobiol Dis 2006; 24:395-402. [PMID: 16956766 DOI: 10.1016/j.nbd.2006.07.014] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2006] [Revised: 07/20/2006] [Accepted: 07/25/2006] [Indexed: 10/24/2022] Open
Abstract
Pneumococcal meningitis (PM) is characterized by an intense inflammatory host reaction that contributes to the development of cortical necrosis and hippocampal apoptosis. Inflammatory conditions in the brain are known to induce tryptophan degradation along the kynurenine pathway, resulting in accumulation of neurotoxic metabolites. In the present study, we investigated the contribution of the kynurenine pathway to brain injury in experimental PM by measuring the concentration of its metabolites and the enzymatic activities and mRNA levels of its major enzymes in the vulnerable brain regions. In the late phase of acute PM, we found a significant transcriptional upregulation of kynurenine-3-hydroxylase and an accumulation of the neurotoxic metabolites 3-hydroxykynurenine (3-HKYN) and 3-hydroxyanthranilic acid in cortex and hippocampus. The positive correlation between the concentration of 3-HKYN and the extent of hippocampal apoptosis adds support to the concept that 3-HKYN contributes to brain injury in PM.
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Affiliation(s)
- Caroline L Bellac
- Institute for Infectious Diseases, University of Bern, Friedbuehlstrasse 51, PO Box 61, CH-3010 Bern, Switzerland
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40
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Yates JR, Heyes MP, Blight AR. 4-chloro-3-hydroxyanthranilate reduces local quinolinic acid synthesis, improves functional recovery, and preserves white matter after spinal cord injury. J Neurotrauma 2006; 23:866-81. [PMID: 16774472 DOI: 10.1089/neu.2006.23.866] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Inflammatory processes within the central nervous system (CNS) contribute significantly to the pathogenesis of a broad range of neurologic diseases, including spinal cord injury (SCI). One mechanism by which immune activation causes neurologic symptoms and tissue injury is via the production of neurotoxins by activated macrophages and microglia. In the present study, the role of the endogenous tryptophan metabolite and neurotoxin quinolinic acid (QUIN) in secondary pathology following traumatic SCI was investigated. Adult Hartley guinea pigs were injured by lateral compression of the spinal cord at the 12th thoracic segment (T12). QUIN had accumulated at the site of injury on day 12 post-injury in proportion to the severity of functional neurologic deficits (as assessed by the cutaneus trunci muscle reflex and motor function score at 5 h post-injury). Systemic administration of the 3-hydroxyanthranilate-3,4-dioxygenase (3-HAD) inhibitor, 4-chloro-3-hydroxyanthranilate (4Cl-3HAA; approximately 100 mg/kg every 12 h, beginning 5 h after injury) attenuated local QUIN production and reduced QUIN accumulation at the site of injury by approximately 50% at day 12, without enhanced accumulations of the neuroprotective metabolite kynurenic acid (KYNA). The severity of secondary functional deficits was also reduced by 4Cl-3HAA. In toluidine blue-stained spinal cord sections, the area of surviving intact white matter at the injury site was increased by approximately 100% in the 4Cl-3HAA-treated group. Sparing of both axons and myelin contributed to this increase. These results support the conclusion that QUIN accumulations at the site of injury contribute to secondary functional deficits and tissue damage following SCI.
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Affiliation(s)
- Jennifer R Yates
- Curriculum in Neurobiology and Division of Neurosurgery, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.
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Muller N, Schwarz M. Schizophrenia as an inflammation-mediated dysbalance of glutamatergic neurotransmission. Neurotox Res 2006; 10:131-48. [PMID: 17062375 DOI: 10.1007/bf03033242] [Citation(s) in RCA: 138] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
This overview tries to bridge the gap between psychoneuroimmunological findings and recent results from pharmacological, neurochemical and genetic studies in schizophrenia. Schizophrenia is a disorder of dopaminergic neurotransmission, but modulation of the dopaminergic system by glutamatergic neurotransmission seems to play a key role. This view is supported by genetic findings of the neuregulin- and dysbindin genes, which have functional impact on the glutamatergic system. Glutamatergic hypofunction, however, is mediated by the N-methyl-D-aspartate (NMDA)-receptor antagonism. The only endogenous NMDA receptor antagonist identified up to now is kynurenic acid (KYNA). Despite the NMDA receptor antagonism, KYNA also blocks, in lower doses, the nicotinergic acetycholine receptor, i.e., increased KYNA levels can explain psychotic symptoms and cognitive deterioration. KYNA levels are described to be higher in the cerebrospinal fluid (CSF) and in critical central nervous system (CNS) regions of schizophrenics as compared to controls. Another line of evidence suggests that a (prenatal) infection is involved in the pathogenesis of schizophrenia. Due to an early sensitization process of the immune system or to a (chronic) infection, which is not cleared through the immune response, an immune imbalance between the type-1 and the type-2 immune responses takes place in schizophrenia. The type-1 response is partially inhibited, while the type-2 response is over-activated. This immune constellation is associated with inhibition of the enzyme indoleamine dioxygenase (IDO), because IDO - located in astrocytes and microglial cells - is inhibited by type-2 cytokines. IDO catalyzes the first step in tryptophan metabolism, the degradation from tryptophan to kynurenine, as does tryptophan 2,3-dioxygenase (TDO). Due to the inhibition of IDO, tryptophan-kynurenine is predominantly metabolized by TDO, which is located in astrocytes, not in microglial or other CNS cells. In schizophrenia, astrocytes in particular are activated, as increased levels of S100B appear. Additionally, they do not have the enzymatic equipment for the normal metabolism-route of tryptophan. Due to the lack of kynurenine hydroxylase (KYN-OHase) in astrocytes, KYNA accumulates in the CNS, while the metabolic pathway in microglial cells is blocked. Accordingly, an increase of TDO activity has been observed in critical CNS regions of schizophrenics. These mechanisms result in an accumulation of KYNA in critical CNS regions. Thus, the immune-mediated glutamatergic-dopaminergic dysregulation may lead to the clinical symptoms of schizophrenia. Therapeutic consequences, e.g., the use of anti-inflammatory cyclo-oxygenase-2 inhibitors, which can also decrease KYNA directly, are discussed.
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Affiliation(s)
- N Muller
- Hospital for Psychiatry and Psychotherapy, Ludwig-Maximilians-Universität, 80336 München, Germany.
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Bari F, Nagy K, Guidetti P, Schwarcz R, Busija DW, Domoki F. Kynurenic acid attenuates NMDA-induced pial arteriolar dilation in newborn pigs. Brain Res 2006; 1069:39-46. [PMID: 16388784 DOI: 10.1016/j.brainres.2005.11.033] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2005] [Revised: 11/11/2005] [Accepted: 11/14/2005] [Indexed: 11/22/2022]
Abstract
The excitatory amino acid glutamate is a potent vasodilator in the central nervous system. Glutamate-induced vasodilation is mediated primarily by N-methyl-D-aspartate (NMDA) and AMPA/kainate (KAIN) receptors. We have now tested whether two metabolites of the kynurenine pathway of tryptophan degradation acting at the NMDA receptor, the antagonist kynurenic acid (KYNA) and the agonist quinolinic acid (QUIN), are capable of modulating the dilation of pial arterioles. The closed cranial window technique was used, and changes in vessel diameter ( approximately 100 microm) were analyzed in anesthetized newborn piglets. Topical application of NMDA (10(-4) M) or KAIN (5 x 10(-5) M) resulted in marked vasodilation (44 +/- 5% and 39 +/- 4%, respectively). Neither KYNA nor QUIN (both at 10(-5) to 10(-3) M) affected the vessel diameter when applied alone. Co-application of KYNA dose-dependently reduced the vasodilation caused by 10(-4) M NMDA and also attenuated the KAIN-induced response. Ten minutes of global cerebral ischemia did not modify the interaction between KAIN and KYNA. In contrast, KYNA did not affect vasodilation to hypercapnia, elicited by the inhalation of 10% CO2. Moreover, endogenous levels of KYNA and QUIN in the cerebral cortex, hippocampus and thalamus were found to be essentially unchanged during the early reperfusion period (0.5-2 h) following an episode of cerebral ischemia. Our data are relevant for the use of drugs that target the kynurenine pathway for therapeutic interventions in cerebrovascular diseases.
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Affiliation(s)
- Ferenc Bari
- Department of Physiology, Faculty of Medicine, University of Szeged, Dóm tér 10, H-6720 Szeged, Hungary.
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Abstract
Human immunodeficiency virus (HIV) infection is often complicated by the development of acquired immunodeficiency syndrome (AIDS) dementia complex (ADC). Quinolinic acid (QUIN) is an end product of tryptophan, metabolized through the kynurenine pathway (KP) that can act as an endogenous brain excitotoxin when produced and released by activated macrophages/microglia, the very cells that are prominent in the pathogenesis of ADC. This review examines QUIN's involvement in the features of ADC and its role in pathogenesis. We then synthesize these findings into a hypothetical model for the role played by QUIN in ADC, and discuss the implications of this model for ADC and other inflammatory brain diseases.
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Affiliation(s)
- Gilles J Guillemin
- Centre for Immunology, Department of Neurology, St Vincent's Hospital, Sydney, Australia
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44
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Yan E, Castillo-Meléndez M, Smythe G, Walker D. Quinolinic acid promotes albumin deposition in Purkinje cell, astrocytic activation and lipid peroxidation in fetal brain. Neuroscience 2005; 134:867-75. [PMID: 16026935 DOI: 10.1016/j.neuroscience.2005.04.056] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2005] [Revised: 03/31/2005] [Accepted: 04/18/2005] [Indexed: 11/30/2022]
Abstract
In high concentrations or after prolonged exposure, the N-methyl-D-aspartate receptor agonist quinolinic acid (QUIN) induces lipid peroxidation, oxidative stress, and cell death in the adult brain, and after i.c.v. injection induces seizures and increases blood-brain barrier permeability. As QUIN is substantially increased in plasma and brain of fetal sheep after endotoxin treatment or maternal tryptophan loading, we examined the effects of increasing plasma QUIN concentrations on the brain of late gestation fetal sheep. Continuous fetal infusion of QUIN (0.1 mmol/h i.v.; n=4) for 12 h increased plasma QUIN concentrations from 22.3+/-6.0-210.8+/-31.4 microM; the infusion of vehicle [normal saline] had no effect on QUIN concentrations (n=4). At 24 h after QUIN infusion glial fibrillary acidic protein immunoreactivity was significantly increased in cerebral gray matter and the granule cell layer of cerebellum, and the lipid peroxide product 4-hydroxynonenal-immunoreactivity and albumin-immunoreactivity were present throughout the cytoplasm of cerebellar Purkinje cells. Extravasation of albumin into the brain was not observed, indicating the cerebral microvasculature with respect to permeability to plasma proteins was normal at the time of analysis. We suggest that increased glial fibrillary acidic protein and 4-hydroxynonenal result from oxidative stress induced by QUIN, and that the increased intracellular albumin in cerebellar Purkinje cells may be an adaptive response.
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Affiliation(s)
- E Yan
- Fetal and Neonatal Research Group, Department of Physiology, Monash University, Clayton, Victoria 3800, Australia
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45
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Stoll LL, Denning GM, Weintraub NL. Potential Role of Endotoxin as a Proinflammatory Mediator of Atherosclerosis. Arterioscler Thromb Vasc Biol 2004; 24:2227-36. [PMID: 15472123 DOI: 10.1161/01.atv.0000147534.69062.dc] [Citation(s) in RCA: 220] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Atherosclerosis is increasingly recognized as a chronic inflammatory disease. Although a variety of inflammatory markers (ie, C-reactive protein) have been associated with atherosclerosis and its consequences, it is important to identify principal mediators of the inflammatory responses. One potentially important source of vascular inflammation in atherosclerosis is bacterial endotoxin. Mutations in Toll-like receptor 4 (TLR-4), an integral component of the endotoxin signaling complex, are fairly common in the Caucasian population and have recently been associated with reduced incidence of atherosclerosis and other cardiovascular diseases in some studies. Moreover, epidemiological studies suggest that endotoxemia at levels as low as 50 pg/mL constitutes a strong risk factor for the development of atherosclerosis. Endotoxin concentrations in this range may be produced by a variety of common subclinical Gram-negative infections. In this article, we outline the main elements of the endotoxin signaling receptor complex that initiates proinflammatory signaling (lipopolysaccharide binding protein [LBP], CD14, TLR-4, and MD-2) and discuss how changes in expression of these molecules may affect proatherogenic responses in the vessel wall. We also describe some of the proinflammatory effects of endotoxin that may be relevant to atherosclerosis, and discuss how serum lipoproteins, especially high-density lipoprotein, may modulate endotoxin-induced inflammatory responses. Further, we discuss recent findings suggesting that the lipid-lowering statins may have an additional protective role in blocking at least some of these proinflammatory signaling pathways. Finally, we discuss species diversity with regard to endotoxin signaling that should be considered when extrapolating experimental data from animal models to humans.
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Affiliation(s)
- Lynn L Stoll
- Department of Internal Medicine, Division of Cardiovascular Diseases, University of Iowa, Iowa City and The VA Medical Center, IA 52242, USA.
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Austin CJD, Mizdrak J, Matin A, Sirijovski N, Kosim-Satyaputra P, Willows RD, Roberts TH, Truscott RJW, Polekhina G, Parker MW, Jamie JF. Optimised expression and purification of recombinant human indoleamine 2,3-dioxygenase. Protein Expr Purif 2004; 37:392-8. [PMID: 15358362 DOI: 10.1016/j.pep.2004.06.025] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2004] [Revised: 06/18/2004] [Indexed: 10/26/2022]
Abstract
The hemoprotein indoleamine 2,3-dioxygenase (IDO) is the first and rate-limiting enzyme in mammalian tryptophan metabolism. It has received considerable attention in recent years, particularly due to its role in the pathogenesis of many diseases. Here, we report attempts to improve soluble expression and purification of hexahistidyl-tagged recombinant human IDO from Escherichia coli (EC538, pREP4, and pQE9-IDO). Significant formation of inclusion bodies was noted at the growth temperature of 37 degrees C, with reduced formation at 30 degrees C. The addition of the natural biosynthetic precursor of protoporphrin IX, delta-aminolevulinic acid (ALA), coupled with optimisation of IPTG induction levels during expression at 30 degrees C and purification by nickel-agarose and size exclusion chromatography, resulted in protein with 1 mol of heme/mol of protein and a specific activity of 160 micromol of kynurenine/h/mg of protein (both identical to native human IDO). The protein was homogeneous in terms of electrophoretic analysis. Yields of soluble protein (3-5 mg/L of bacterial culture) and heme content are greater than previously reported.
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Guillemin GJ, Smith DG, Smythe GA, Armati PJ, Brew BJ. Expression of the kynurenine pathway enzymes in human microglia and macrophages. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2004; 527:105-12. [PMID: 15206722 DOI: 10.1007/978-1-4615-0135-0_12] [Citation(s) in RCA: 167] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
There is good evidence that the kynurenine pathway (KP) and one of its products, quinolinic acid (QUIN) play a role in the pathogenesis of neurological diseases. Monocytic cells are known to be the major producers of QUIN. However, macrophages have the ability to produce approximately 20 to 30-fold more QUIN than microglia. The molecular origin of this difference has not been clarified yet. Using unstimulated and IFN-gamma-stimulated cultures of human fcetal microglia and adult macrophages, we assayed mRNA expression of 8 key enzymes of the KP using RT-PCR and QUIN production using GC-MS. We found that after stimulation with IFN-gamma microglia produced de novo 20-fold less QUIN than macrophages. This quantitative difference in the ability to produce QUIN appears to be associated with a lower expression of 3 important enzymes of the KP in microglia: indoleamine 2,3-dioxygenase (IDO), kynureninase (KYNase) and kynurenine hydroxylase (KYN(OH)ase). These results suggest that activated infiltrating macrophages are the most potent QUIN producers during brain inflammatory diseases with playing a lesser role.
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Depboylu C, Reinhart TA, Takikawa O, Imai Y, Maeda H, Mitsuya H, Rausch D, Eiden LE, Weihe E. Brain virus burden and indoleamine-2,3-dioxygenase expression during lentiviral infection of rhesus monkey are concomitantly lowered by 6-chloro-2',3'-dideoxyguanosine. Eur J Neurosci 2004; 19:2997-3005. [PMID: 15182307 DOI: 10.1111/j.0953-816x.2004.03404.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Increased kynurenine pathway metabolism has been implicated in the aetiology of lentiviral encephalopathy. Indoleamine-2,3-dioxygenase (IDO) initiates the increased production of kynurenine pathway metabolites like quinolinic acid (QUIN). QUIN itself is elevated in AIDS-diseased monkey and human brain parenchyma and cerebrospinal fluid at levels excitotoxic for neurons in vitro. This study investigates the cellular origin of IDO biosynthesis in the brain of rhesus monkeys infected with simian immunodeficiency virus (SIV) and explores the effects of CNS-permeant antiretroviral treatment. IDO transcript and protein were absent from the brain of non-infected and SIV-infected asymptomatic monkeys. IDO biosynthesis was induced in the brain of monkeys exhibiting AIDS. Nodule and multinucleated giant cell-forming macrophages were the main sources of IDO synthesis. Treatment with the lipophilic 6-chloro-2',3'-dideoxyguanosine suppressed IDO expression in the brain of AIDS-diseased monkeys. The effectiveness of this treatment was confirmed by the reduction of virus burden and SIV-induced perivascular infiltrates, mononuclear nodules and multinucleated giant cells. Our data demonstrate that brain IDO biosynthesis is induced in a subset of monocyte-derived cells, depends on viral burden and is susceptible to antiretroviral treatment. Thus, IDO induction is associated with reversible overt inflammatory events localized to areas of active viral replication in the SIV-infected brain.
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Affiliation(s)
- Candan Depboylu
- Department of Molecular Neuroscience, Institute of Anatomy and Cell Biology, Philipps University, Marburg, Germany
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Pechnick RN, Chesnokova VM, Kariagina A, Price S, Bresee CJ, Poland RE. Reduced immobility in the forced swim test in mice with a targeted deletion of the leukemia inhibitory factor (LIF) gene. Neuropsychopharmacology 2004; 29:770-6. [PMID: 14970834 DOI: 10.1038/sj.npp.1300402] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Cytokines are a large and diverse group of polypeptides that are rapidly released in response to tissue injury, infection, and inflammation. Besides their effects in the periphery, cytokines also affect the central nervous system (CNS). There has been increasing interest in the potential role of cytokines in the behavioral features of depressive disorders. One cytokine that might be a candidate for a role in the etiology of depression is leukemia inhibitory factor (LIF). LIF mRNA has been detected in the hypothalamus, hippocampus, amygdala, cerebellum, cerebral cortex, and basal forebrain nuclei. The role of LIF in the CNS has not been fully elucidated. Based upon the hypothesis that cytokines might have a role in depression, the present study characterized the behavior of mice with a targeted disruption of the LIF gene (LIF knockouts) in the forced swim test, an animal model used to measure depressive-like behavior and the response to antidepressants. It was found that LIF knockout mice show reduced immobility in the forced swim test, suggesting that LIF might have a potential role in the etiology of some forms of depression.
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Affiliation(s)
- Robert N Pechnick
- Department of Psychiatry and Mental Health, Cedars-Sinai Medical Center, Los Angeles, CA 9048, USA.
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Guillemin GJ, Smythe G, Takikawa O, Brew BJ. Expression of indoleamine 2,3-dioxygenase and production of quinolinic acid by human microglia, astrocytes, and neurons. Glia 2004; 49:15-23. [PMID: 15390107 DOI: 10.1002/glia.20090] [Citation(s) in RCA: 358] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
There is good evidence that the kynurenine pathway (KP) and one of its end products, quinolinic acid (QUIN) play a role in the pathogenesis of several major neurological diseases. While QUIN has been shown to be produced in neurotoxic concentrations by macrophages and microglia, the capacity of astrocytes and neurons to produce QUIN is controversial. Using interferon gamma (IFN-gamma)-stimulated primary cultures of human mixed brain cells, we assayed expression of the KP regulatory enzyme indoleamine 2,3-dioxygenase (IDO) and QUIN production by immunocytochemistry. Using IFN-gamma-stimulated purified cultures of neurons, astrocytes, microglia and macrophages, we studied IDO expression by RT-PCR and production of QUIN using mass spectrometry. We found that astrocytes, neurons, and microglia expressed IDO but only microglia were able to produce detectable amounts of QUIN. However, astrocytes and neurons had the ability to catabolize QUIN. This study also provides the first evidence of IDO expression and lack of production of QUIN in culture of primary human neurons.
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