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Brown SJ, Christofides K, Weissleder C, Huang XF, Shannon Weickert C, Lim CK, Newell KA. Sex- and suicide-specific alterations in the kynurenine pathway in the anterior cingulate cortex in major depression. Neuropsychopharmacology 2024; 49:584-592. [PMID: 37735504 PMCID: PMC10789861 DOI: 10.1038/s41386-023-01736-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 08/28/2023] [Accepted: 09/05/2023] [Indexed: 09/23/2023]
Abstract
Major depressive disorder (MDD) is a serious psychiatric disorder that in extreme cases can lead to suicide. Evidence suggests that alterations in the kynurenine pathway (KP) contribute to the pathology of MDD. Activation of the KP leads to the formation of neuroactive metabolites, including kynurenic acid (KYNA) and quinolinic acid (QUIN). To test for changes in the KP, postmortem anterior cingulate cortex (ACC) was obtained from the National Institute of Health NeuroBioBank. Gene expression of KP enzymes and relevant neuroinflammatory markers were investigated via RT-qPCR (Fluidigm) and KP metabolites were measured using liquid chromatography-mass spectrometry in tissue from individuals with MDD (n = 44) and matched nonpsychiatric controls (n = 36). We report increased IL6 and IL1B mRNA in MDD. Subgroup analysis found that female MDD subjects had significantly decreased KYNA and a trend decrease in the KYNA/QUIN ratio compared to female controls. In addition, MDD subjects that died by suicide had significantly decreased KYNA in comparison to controls and MDD subjects that did not die by suicide, while subjects that did not die by suicide had increased KYAT2 mRNA, which we hypothesise may protect against a decrease in KYNA. Overall, we found sex- and suicide-specific alterations in the KP in the ACC in MDD. This is the first molecular evidence in the brain of subgroup specific changes in the KP in MDD, which not only suggests that treatments aimed at upregulation of the KYNA arm in the brain may be favourable for female MDD sufferers but also might assist managing suicidal behaviour.
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Affiliation(s)
- Samara J Brown
- School of Medical, Indigenous and Health Sciences and Molecular Horizons, University of Wollongong, Wollongong, NSW, Australia.
| | | | - Christin Weissleder
- Schizophrenia Research Laboratory, Neuroscience Research Australia, Randwick, NSW, Australia
- Mechanism and Therapy of Genetic Brain Diseases, Institut Imagine, Paris, France
| | - Xu-Feng Huang
- School of Medical, Indigenous and Health Sciences and Molecular Horizons, University of Wollongong, Wollongong, NSW, Australia
| | - Cynthia Shannon Weickert
- Schizophrenia Research Laboratory, Neuroscience Research Australia, Randwick, NSW, Australia
- Department of Neuroscience & Physiology, Upstate Medical University, Syracuse, NY, USA
- Discipline of Psychiatry and Mental Health, Faculty of Medicine, University of New South Wales, Sydney, NSW, Australia
| | - Chai K Lim
- Schizophrenia Research Laboratory, Neuroscience Research Australia, Randwick, NSW, Australia
- Macquarie Medical School, Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, NSW, Australia
| | - Kelly A Newell
- School of Medical, Indigenous and Health Sciences and Molecular Horizons, University of Wollongong, Wollongong, NSW, Australia.
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Hüfner K, Vedova S, Tymoszuk P, Nelles P, Bruckner T, Deisenhammer EA, Egeter J, Galffy M, Giesinger JM, Lehmann J, Oberhammer M, Rockenschaub J, Sacher M, Holzner B, Gostner JM, Sperner-Unterweger B. The effect of inflammation, SARS-CoV-2 infection, age and mental health on serotonin, and kynurenine and catecholamine pathway metabolites. Psychoneuroendocrinology 2023; 156:106334. [PMID: 37481962 DOI: 10.1016/j.psyneuen.2023.106334] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Revised: 06/12/2023] [Accepted: 07/11/2023] [Indexed: 07/25/2023]
Abstract
BACKGROUND A high prevalence of mental disorders following COVID-19 has been described. It is therefore essential to elucidate underlying biological mechanisms linking SARS-CoV-2 infection and mental health. The kynurenine and catecholamine metabolic pathways are modulated by inflammation and can affect systemic levels of serotonin and dopamine. Their activity may hence link physical disorders with mental health. We investigated factors that affect kynurenine and catecholamine pathway activity in SARS-CoV-2 infection and recovery. METHODS The cross-sectional SIMMUN (n = 165) and longitudinal INCOV cohort (n = 167, Su et al. 2022) were analyzed. Demographic and clinical characteristic, inflammatory markers, SARS-CoV-2 infection, symptoms of depression and anxiety (HADS), and mental stress (PSS-4) served as explanatory variables. Blood serotonin and markers of kynurenine (kynurenine/tryptophan ratio), and catecholamine pathway activity (dopamine 3-O-sulfate, phenylalanine/tyrosine ratio) were modeled by multi-parameter linear regression. RESULTS In the SIMMUN cohort, the inflammatory marker neopterin (β = 0.47 [95% CI: 0.34-0.61]), SARS-CoV-2-positivity (0.42 [0.16-0.68]), mental stress (0.18 [0.055-0.31]), and age (0.26 [0.12-0.39]) were positively associated with the kynurenine/tryptophan ratio. The phenylalanine/tyrosine ratio was lower in SARS-CoV-2-positive than uninfected participants (-0.38 [-0.68 to -0.08]). In the INCOV cohort, markers of inflammation were associated with lower serotonin (IL6: -0.22 [-0.38 to -0.053]) and dopamine 3-O-sulfate levels (interferon-gamma: -0.15 [-0.26 to -0.036]). Serotonin (0.76 [0.34-1.2]) and dopamine 3-O-sulfate levels (0.63 [0.28-0.99]) were higher during recovery than in acute SARS-CoV-2 infection. CONCLUSION SARS-CoV-2 infection, inflammation, age and mental stress are key independent predictors of kynurenine pathway activity, which may influence serotonin availability. The catecholamine pathway was also affected in SARS-CoV-2 infection. Altered activity of these pathways may contribute to impaired mental health following COVID-19.
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Affiliation(s)
- Katharina Hüfner
- University Hospital of Psychiatry II, Department of Psychiatry, Psychotherapy, Psychosomatics and Medical Psychology, Medical University Innsbruck, Innsbruck, Austria.
| | - Sophia Vedova
- University Hospital of Psychiatry II, Department of Psychiatry, Psychotherapy, Psychosomatics and Medical Psychology, Medical University Innsbruck, Innsbruck, Austria
| | | | - Philipp Nelles
- University Hospital of Psychiatry II, Department of Psychiatry, Psychotherapy, Psychosomatics and Medical Psychology, Medical University Innsbruck, Innsbruck, Austria
| | - Tobias Bruckner
- University Hospital of Psychiatry II, Department of Psychiatry, Psychotherapy, Psychosomatics and Medical Psychology, Medical University Innsbruck, Innsbruck, Austria
| | - Eberhard A Deisenhammer
- University Hospital of Psychiatry II, Department of Psychiatry, Psychotherapy, Psychosomatics and Medical Psychology, Medical University Innsbruck, Innsbruck, Austria; University Hospital of Psychiatry I, Department of Psychiatry, Psychotherapy, Psychosomatics and Medical Psychology, Medical University Innsbruck, Innsbruck, Austria
| | - Jonas Egeter
- University Hospital of Psychiatry II, Department of Psychiatry, Psychotherapy, Psychosomatics and Medical Psychology, Medical University Innsbruck, Innsbruck, Austria
| | - Matyas Galffy
- University Hospital of Psychiatry II, Department of Psychiatry, Psychotherapy, Psychosomatics and Medical Psychology, Medical University Innsbruck, Innsbruck, Austria
| | - Johannes M Giesinger
- University Hospital of Psychiatry II, Department of Psychiatry, Psychotherapy, Psychosomatics and Medical Psychology, Medical University Innsbruck, Innsbruck, Austria
| | - Jens Lehmann
- University Hospital of Psychiatry II, Department of Psychiatry, Psychotherapy, Psychosomatics and Medical Psychology, Medical University Innsbruck, Innsbruck, Austria
| | - Maria Oberhammer
- University Hospital of Psychiatry I, Department of Psychiatry, Psychotherapy, Psychosomatics and Medical Psychology, Medical University Innsbruck, Innsbruck, Austria
| | - Joachim Rockenschaub
- University Hospital of Psychiatry II, Department of Psychiatry, Psychotherapy, Psychosomatics and Medical Psychology, Medical University Innsbruck, Innsbruck, Austria
| | - Magdalena Sacher
- Department of Visceral, Transplant and Thoracic Surgery (VTT), Medical University Innsbruck, Innsbruck, Austria
| | - Bernhard Holzner
- University Hospital of Psychiatry II, Department of Psychiatry, Psychotherapy, Psychosomatics and Medical Psychology, Medical University Innsbruck, Innsbruck, Austria
| | - Johanna M Gostner
- Institute of Medical Biochemistry, Medical University Innsbruck, Innsbruck, Austria
| | - Barbara Sperner-Unterweger
- University Hospital of Psychiatry II, Department of Psychiatry, Psychotherapy, Psychosomatics and Medical Psychology, Medical University Innsbruck, Innsbruck, Austria
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Is SARS-CoV-2 a Risk Factor of Bipolar Disorder?-A Narrative Review. J Clin Med 2022; 11:jcm11206060. [PMID: 36294388 PMCID: PMC9604904 DOI: 10.3390/jcm11206060] [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: 09/28/2022] [Revised: 10/10/2022] [Accepted: 10/12/2022] [Indexed: 11/07/2022] Open
Abstract
For 2.5 years we have been facing the coronavirus disease (COVID-19) and its health, social and economic effects. One of its known consequences is the development of neuropsychiatric diseases such as anxiety and depression. However, reports of manic episodes related to COVID-19 have emerged. Mania is an integral part of the debilitating illness-bipolar disorder (BD). Due to its devastating effects, it is therefore important to establish whether SARS-CoV-2 infection is a causative agent of this severe mental disorder. In this narrative review, we discuss the similarities between the disorders caused by SARS-CoV-2 and those found in patients with BD, and we also try to answer the question of whether SARS-CoV-2 infection may be a risk factor for the development of this affective disorder. Our observation shows that disorders in COVID-19 showing the greatest similarity to those in BD are cytokine disorders, tryptophan metabolism, sleep disorders and structural changes in the central nervous system (CNS). These changes, especially intensified in severe infections, may be a trigger for the development of BD in particularly vulnerable people, e.g., with family history, or cause an acute episode in patients with a pre-existing BD.
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Is Poor Lithium Response in Individuals with Bipolar Disorder Associated with Increased Degradation of Tryptophan along the Kynurenine Pathway? Results of an Exploratory Study. J Clin Med 2022; 11:jcm11092517. [PMID: 35566641 PMCID: PMC9103936 DOI: 10.3390/jcm11092517] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Revised: 04/15/2022] [Accepted: 04/27/2022] [Indexed: 11/17/2022] Open
Abstract
Bipolar disorder is associated with an inflammation-triggered elevated catabolism of tryptophan to the kynurenine pathway, which impacts psychiatric symptoms and outcomes. The data indicate that lithium exerts anti-inflammatory effects by inhibiting indoleamine-2,3-dioxygenase (IDO)-1 activity. This exploratory study aimed to investigate the tryptophan catabolism in individuals with bipolar disorder (n = 48) compared to healthy controls (n = 48), and the associations with the response to mood stabilizers such as lithium, valproate, or lamotrigine rated with the Retrospective Assessment of the Lithium Response Phenotype Scale (or the Alda scale). The results demonstrate an association of a poorer response to lithium with higher levels of kynurenine, kynurenine/tryptophan ratio as a proxy for IDO-1 activity, as well as quinolinic acid, which, overall, indicates a pro-inflammatory state with a higher degradation of tryptophan towards the neurotoxic branch. The treatment response to valproate and lamotrigine was not associated with the levels of the tryptophan metabolites. These findings support the anti-inflammatory properties of lithium. Furthermore, since quinolinic acid has neurotoxic features via the glutamatergic pathway, they also strengthen the assumption that the clinical drug response might be associated with biochemical processes. The relationship between the lithium response and the measurements of the tryptophan to the kynurenine pathway is of clinical relevance and may potentially bring advantages towards a personalized medicine approach to bipolar disorder that allows for the selection of the most effective mood-stabilizing drug.
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Brown SJ, Brown AM, Purves-Tyson TD, Huang XF, Shannon Weickert C, Newell KA. Alterations in the kynurenine pathway and excitatory amino acid transporter-2 in depression with and without psychosis: Evidence of a potential astrocyte pathology. J Psychiatr Res 2022; 147:203-211. [PMID: 35063739 DOI: 10.1016/j.jpsychires.2021.12.039] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 11/24/2021] [Accepted: 12/18/2021] [Indexed: 11/19/2022]
Abstract
Evidence, largely obtained from peripheral studies, suggests that alterations in the kynurenine pathway contribute to the aetiology of depression and disorders involving psychosis. Stimulation of the kynurenine pathway leads to the formation of neuroactive metabolites, including kynurenic acid (predominantly in astrocytes) and quinolinic acid (predominantly in microglia), which are antagonists and agonists of the glutamate NMDA receptor, respectively. In this study, we measured gene expression via qRT-PCR of the main kynurenine pathway enzymes in the anterior cingulate cortex (ACC) in people with major depressive disorder and matched controls. In parallel, we tested for diagnostic differences in gene expression of relevant glial markers. We used total RNA isolated from the ACC from depression subjects with psychosis (n = 12) and without psychosis (n = 12), and non-psychiatric controls (n = 12) provided by the Stanley Medical Research Institute. In the ACC, KYAT1 (KAT I), AADAT (KAT II), and the astrocytic SLC1A2 (EAAT2) mRNAs, were significantly increased in depression, when combining those with and without psychosis. The increased KYAT1 and AADAT mRNA indicates that depression is associated with increased activation of the kynurenic acid arm of the kynurenine pathway in the ACC, suggesting an astrocyte response in depression. Considering EAAT2 and KATs increase astrocytic glutamate uptake and production of the NMDA receptor antagonist kynurenic acid, the observed increases of these markers may relate to changes in glutamatergic signalling in depression. These results suggest dysfunction of the kynurenine pathway in the brain in depression and point to the kynurenine pathway as a possible driver of glutamate dysfunction in depression.
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Affiliation(s)
- Samara J Brown
- School of Medicine and Molecular Horizons, University of Wollongong, Wollongong, NSW, 2522, Australia; Illawarra Health and Medical Research Institute, Wollongong, New South Wales, 2522, Australia
| | - Amelia M Brown
- Schizophrenia Research Laboratory, Neuroscience Research Australia, Randwick, New South Wales, 2031, Australia
| | - Tertia D Purves-Tyson
- Schizophrenia Research Laboratory, Neuroscience Research Australia, Randwick, New South Wales, 2031, Australia; School of Psychiatry, Faculty of Medicine, University of New South Wales, Randwick, New South Wales, 2031, Australia
| | - Xu-Feng Huang
- School of Medicine and Molecular Horizons, University of Wollongong, Wollongong, NSW, 2522, Australia; Illawarra Health and Medical Research Institute, Wollongong, New South Wales, 2522, Australia
| | - Cynthia Shannon Weickert
- Schizophrenia Research Laboratory, Neuroscience Research Australia, Randwick, New South Wales, 2031, Australia; School of Psychiatry, Faculty of Medicine, University of New South Wales, Randwick, New South Wales, 2031, Australia; Department of Neuroscience & Physiology, Upstate Medical University, Syracuse, NY, 13210, USA
| | - Kelly A Newell
- School of Medicine and Molecular Horizons, University of Wollongong, Wollongong, NSW, 2522, Australia; Illawarra Health and Medical Research Institute, Wollongong, New South Wales, 2522, Australia.
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Miller CL. The Epigenetics of Psychosis: A Structured Review with Representative Loci. Biomedicines 2022; 10:biomedicines10030561. [PMID: 35327363 PMCID: PMC8945330 DOI: 10.3390/biomedicines10030561] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Revised: 02/24/2022] [Accepted: 02/26/2022] [Indexed: 02/04/2023] Open
Abstract
The evidence for an environmental component in chronic psychotic disorders is strong and research on the epigenetic manifestations of these environmental impacts has commenced in earnest. In reviewing this research, the focus is on three genes as models for differential methylation, MCHR1, AKT1 and TDO2, each of which have been investigated for genetic association with psychotic disorders. Environmental factors associated with psychotic disorders, and which interact with these model genes, are explored in depth. The location of transcription factor motifs relative to key methylation sites is evaluated for predicted gene expression results, and for other sites, evidence is presented for methylation directing alternative splicing. Experimental results from key studies show differential methylation: for MCHR1, in psychosis cases versus controls; for AKT1, as a pre-existing methylation pattern influencing brain activation following acute administration of a psychosis-eliciting environmental stimulus; and for TDO2, in a pattern associated with a developmental factor of risk for psychosis, in all cases the predicted expression impact being highly dependent on location. Methylation induced by smoking, a confounding variable, exhibits an intriguing pattern for all three genes. Finally, how differential methylation meshes with Darwinian principles is examined, in particular as it relates to the “flexible stem” theory of evolution.
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Kopra E, Mondelli V, Pariante C, Nikkheslat N. Ketamine's effect on inflammation and kynurenine pathway in depression: A systematic review. J Psychopharmacol 2021; 35:934-945. [PMID: 34180293 PMCID: PMC8358579 DOI: 10.1177/02698811211026426] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND Ketamine is a novel rapid-acting antidepressant with high efficacy in treatment-resistant patients. Its exact therapeutic mechanisms of action are unclear; however, in recent years its anti-inflammatory properties and subsequent downstream effects on tryptophan (TRP) metabolism have sparked research interest. AIM This systematic review examined the effect of ketamine on inflammatory markers and TRP-kynurenine (KYN) pathway metabolites in patients with unipolar and bipolar depression and in animal models of depression. METHODS MEDLINE, Embase, and PsycINFO databases were searched on October 2020 (1806 to 2020). RESULTS Out of 807 initial results, nine human studies and 22 animal studies on rodents met the inclusion criteria. Rodent studies provided strong support for ketamine-induced decreases in pro-inflammatory cytokines, namely in interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α and indicated anti-inflammatory effects on TRP metabolism, including decreases in the enzyme indoleamine 2,3-dioxygenase (IDO). Clinical evidence was less robust with high heterogeneity between sample characteristics, but most experiments demonstrated decreases in peripheral inflammation including in IL-1β, IL-6, and TNF-α. Preliminary support was also found for reduced activation of the neurotoxic arm of the KYN pathway. CONCLUSION Ketamine appears to induce anti-inflammatory effects in at least a proportion of depressed patients. Suggestions for future research include investigation of markers in the central nervous system and examination of clinical relevance of inflammatory changes.
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Affiliation(s)
- Emma Kopra
- Department of Psychological Medicine, Institute of Psychiatry, Psychology and Neuroscience, King's College London, UK
| | - Valeria Mondelli
- Department of Psychological Medicine, Institute of Psychiatry, Psychology and Neuroscience, King's College London, UK
- National Institute for Health Research (NIHR) Mental Health Biomedical Research Centre at South London and Maudsley NHS Foundation Trust and King's College London, UK
| | - Carmine Pariante
- Department of Psychological Medicine, Institute of Psychiatry, Psychology and Neuroscience, King's College London, UK
- National Institute for Health Research (NIHR) Mental Health Biomedical Research Centre at South London and Maudsley NHS Foundation Trust and King's College London, UK
| | - Naghmeh Nikkheslat
- Department of Psychological Medicine, Institute of Psychiatry, Psychology and Neuroscience, King's College London, UK
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Pharmacophore-Based Virtual Screening of Novel Competitive Inhibitors of the Neurodegenerative Disease Target Kynurenine-3-Monooxygenase. Molecules 2021; 26:molecules26113314. [PMID: 34073016 PMCID: PMC8199213 DOI: 10.3390/molecules26113314] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Revised: 05/26/2021] [Accepted: 05/26/2021] [Indexed: 11/27/2022] Open
Abstract
The pathogenesis of several neurodegenerative diseases such as Alzheimer’s or Huntington’s disease has been associated with metabolic dysfunctions caused by imbalances in the brain and cerebral spinal fluid levels of neuroactive metabolites. Kynurenine monooxygenase (KMO) is considered an ideal therapeutic target for the regulation of neuroactive tryptophan metabolites. Despite significant efforts, the known KMO inhibitors lack blood–brain barrier (BBB) permeability and upon the mimicking of the substrate binding mode, are subject to produce reactive oxygen species as a side reaction. The computational drug design is further complicated by the absence of complete crystal structure information for human KMO (hKMO). In the current work, we performed virtual screening of readily available compounds using several protein–ligand complex pharmacophores. Each of the pharmacophores accounts for one of three distinct reported KMO protein-inhibitor binding conformations. As a result, six novel KMO inhibitors were discovered based on an in vitro fluorescence assay. Compounds VS1 and VS6 were predicted to be BBB permeable and avoid the hydrogen peroxide production dilemma, making them valuable, novel hit compounds for further drug property optimization and advancement in the drug design pipeline.
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The kynurenine pathway in major depression: What we know and where to next. Neurosci Biobehav Rev 2021; 127:917-927. [PMID: 34029552 DOI: 10.1016/j.neubiorev.2021.05.018] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Revised: 05/18/2021] [Accepted: 05/19/2021] [Indexed: 12/27/2022]
Abstract
Major depression is a serious psychiatric disorder, occurring in up to 20 % of the population. Despite its devastating burden, the neurobiological changes associated with depression are not fully understood. A growing body of evidence suggests the kynurenine pathway is implicated in the pathophysiology of depression. In this review, we bring together the literature examining elements of the kynurenine pathway in depression and explore the implications for the pathophysiology and treatment of depression, while highlighting the gaps in the current knowledge. Current research indicates an increased potential for neurotoxic activity of the kynurenine pathway in peripheral blood samples but an increased activation of the putative neuroprotective arm in some brain regions in depression. The disconnect between these findings requires further investigation, with a greater research effort on elucidating the central effects of the kynurenine pathway in driving depression symptomology. Research investigating the benefits of targeting the kynurenine pathway centred on human brain findings and the heterogenous subtypes of depression will help guide the identification of effective drug targets in depression.
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Hebbrecht K, Skorobogatov K, Giltay EJ, Coppens V, De Picker L, Morrens M. Tryptophan Catabolites in Bipolar Disorder: A Meta-Analysis. Front Immunol 2021; 12:667179. [PMID: 34093561 PMCID: PMC8170319 DOI: 10.3389/fimmu.2021.667179] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Accepted: 04/13/2021] [Indexed: 02/02/2023] Open
Abstract
Objective Tryptophan catabolites (TRYCATs) are implicated in the pathophysiology of mood disorders by mediating immune-inflammation and neurodegenerative processes. We performed a meta-analysis of TRYCAT levels in bipolar disorder (BD) patients compared to healthy controls. Methods A systematic literature search in seven electronic databases (PubMed, Embase, Web of Science, Cochrane, Emcare, PsycINFO, Academic Search Premier) was conducted on TRYCAT levels in cerebrospinal fluid or peripheral blood according to the PRISMA statement. A minimum of three studies per TRYCAT was required for inclusion. Standardized mean differences (SMD) were computed using random effect models. Subgroup analyses were performed for BD patients in a different mood state (depressed, manic). The methodological quality of the studies was rated using the modified Newcastle-Ottawa Quality assessment Scale. Results Twenty-one eligible studies were identified. Peripheral levels of tryptophan (SMD = -0.44; p < 0.001), kynurenine (SMD = - 0.3; p = 0.001) and kynurenic acid (SMD = -.45; p = < 0.001) were lower in BD patients versus healthy controls. In the only three eligible studies investigating TRP in cerebrospinal fluid, tryptophan was not significantly different between BD and healthy controls. The methodological quality of the studies was moderate. Subgroup analyses revealed no significant difference in TRP and KYN values between manic and depressed BD patients, but these results were based on a limited number of studies. Conclusion The TRYCAT pathway appears to be downregulated in BD patients. There is a need for more and high-quality studies of peripheral and central TRYCAT levels, preferably using longitudinal designs.
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Affiliation(s)
- Kaat Hebbrecht
- 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
| | - 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
| | - Erik J. Giltay
- Faculty of Medicine and Health Sciences, Collaborative Antwerp Psychiatric Research Institute (CAPRI), University of Antwerp, Antwerp, Belgium
- Department of Psychiatry, Leiden University Medical Center, Leiden, Netherlands
| | - 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
| | - 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
| | - 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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Rudzki L, Stone TW, Maes M, Misiak B, Samochowiec J, Szulc A. Gut microbiota-derived vitamins - underrated powers of a multipotent ally in psychiatric health and disease. Prog Neuropsychopharmacol Biol Psychiatry 2021; 107:110240. [PMID: 33428888 DOI: 10.1016/j.pnpbp.2020.110240] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 11/19/2020] [Accepted: 12/30/2020] [Indexed: 02/06/2023]
Abstract
Despite the well-established roles of B-vitamins and their deficiencies in health and disease, there is growing evidence indicating a key role of those nutrients in functions of the central nervous system and in psychopathology. Clinical data indicate the substantial role of B-vitamins in various psychiatric disorders, including major depression, bipolar disorder, schizophrenia, autism, and dementia, including Alzheimer's and Parkinson's diseases. As enzymatic cofactors, B-vitamins are involved in many physiological processes such as the metabolism of glucose, fatty acids and amino acids, metabolism of tryptophan in the kynurenine pathway, homocysteine metabolism, synthesis and metabolism of various neurotransmitters and neurohormones including serotonin, dopamine, adrenaline, acetylcholine, GABA, glutamate, D-serine, glycine, histamine and melatonin. Those vitamins are highly involved in brain energetic metabolism and respiration at the cellular level. They have a broad range of anti-inflammatory, immunomodulatory, antioxidant and neuroprotective properties. Furthermore, some of those vitamins are involved in the regulation of permeability of the intestinal and blood-brain barriers. Despite the fact that a substantial amount of the above vitamins is acquired from various dietary sources, deficiencies are not uncommon, and it is estimated that micronutrient deficiencies affect about two billion people worldwide. The majority of gut-resident microbes and the broad range of bacteria available in fermented food, express genetic machinery enabling the synthesis and metabolism of B-vitamins and, consequently, intestinal microbiota and fermented food rich in probiotic bacteria are essential sources of B-vitamins for humans. All in all, there is growing evidence that intestinal bacteria-derived vitamins play a significant role in physiology and that dysregulation of the "microbiota-vitamins frontier" is related to various disorders. In this review, we will discuss the role of vitamins in mental health and explore the perspectives and potential of how gut microbiota-derived vitamins could contribute to mental health and psychiatric treatment.
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Affiliation(s)
- Leszek Rudzki
- The Charleston Centre, 49 Neilston Road, Paisley PA2 6LY, UK.
| | | | - Michael Maes
- Department of Psychiatry, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand; Department of Psychiatry, Medical University of Plovdiv, Bulgaria; IMPACT Strategic Research Center, Deakin University, Geelong, Australia
| | - Błażej Misiak
- Department of Psychiatry, Wroclaw Medical University, Pasteura 10 Street, 50-367 Wroclaw, Poland
| | - Jerzy Samochowiec
- Department of Psychiatry, Pomeranian Medical University, Broniewskiego 26 Street, 71-460 Szczecin, Poland
| | - Agata Szulc
- Department of Psychiatry, Medical University of Warsaw, Poland
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12
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Cao B, Chen Y, Ren Z, Pan Z, McIntyre RS, Wang D. Dysregulation of kynurenine pathway and potential dynamic changes of kynurenine in schizophrenia: A systematic review and meta-analysis. Neurosci Biobehav Rev 2021; 123:203-214. [PMID: 33513412 DOI: 10.1016/j.neubiorev.2021.01.018] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Revised: 01/19/2021] [Accepted: 01/20/2021] [Indexed: 12/26/2022]
Abstract
The kynurenine (KYN) pathway is postulated to play various roles in immune system dysregulation of schizophrenia (SCZ). We conducted a meta-analysis to explore the association between six key metabolites of KYN pathway (i.e., tryptophan (TRP), KYN, quinolinic acid (QUIN), and kynurenic acid (KYNA)) and SCZ. Priori Bonferroni adjustments were conducted for multiple comparisons. In total, 42 studies that examined the relationship between the metabolites in KYN pathway mentioned above and SCZ in 4217 participants and nine studies that examined alterations of these metabolites after antipsychotic treatments were included. The results demonstrate that (1) subjects with prescribed medication had significantly higher KYN levels when compared to controls; (2) higher KYN levels in cerebrospinal fluid (CSF), lower plasma KYN levels and higher CSF KYNA levels were associated with SCZ; (3) the KYN levels were higher in subjects with SCZ after antipsychotic treatments when compared with baseline. The evidence provides valuable insight of the potential underlying involvement of the KYN pathway in the pathogenesis of SCZ.
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Affiliation(s)
- Bing Cao
- Key Laboratory of Cognition and Personality, Faculty of Psychology, Ministry of Education, Southwest University (SWU), Chongqing, 400715, PR China; National Demonstration Center for Experimental Psychology Education (Southwest University), Chongqing, PR China.
| | - Yan Chen
- Dalla Lana School of Public Health, University of Toronto, 155 College St., Toronto, ON, Canada
| | - Zhongyu Ren
- College of Physical Education, Southwest University, Chongqing, PR China
| | - Zihang Pan
- Duke-NUS Medical School, Singapore, Singapore; Mood Disorders Psychopharmacology Unit, University Health Network, Toronto, Canada
| | - Roger S McIntyre
- Mood Disorders Psychopharmacology Unit, University Health Network, Toronto, Canada; Department of Psychiatry, University of Toronto, Toronto, Canada; Department of Pharmacology, University of Toronto, Toronto, Canada; Brain and Cognition Discovery Foundation, Toronto, ON, Canada
| | - Dongfang Wang
- NHC Key Laboratory of Diagnosis and Treatment on Brain Functional Diseases, The First Affiliated Hospital of Chongqing Medical University, Chongqing, PR China; Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, PR China.
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13
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Cao B, Chen Y, McIntyre RS, Yan L. Acyl-Carnitine plasma levels and their association with metabolic syndrome in individuals with schizophrenia. Psychiatry Res 2020; 293:113458. [PMID: 32977055 DOI: 10.1016/j.psychres.2020.113458] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/27/2020] [Accepted: 09/13/2020] [Indexed: 02/06/2023]
Abstract
The metabolic syndrome (MetS) affects individuals with schizophrenia at a higher rate when compared to individuals in the general population. Accumulating evidence indicated that subjects with MetS generally manifest elevated levels of acyl-carnitines, which are important carriers for transporting fatty acyl group. Abnormalities of acyl-carnitines in individuals with schizophrenia with or without MetS had not been sufficiently characterized. We conducted this post-hoc analysis with our published data to further evaluate the differences of 29 acyl-carnitines in 46 individuals with schizophrenia with MetS and 123 without MetS. The rate of MetS was 27.2% (46/169) in the individuals with schizophrenia. After FDR correction, the individuals with schizophrenia and MetS showed significantly higher levels of 17 plasma acyl-carnitines, compared to individuals without MetS. Eight acyl-carnitines (i.e., C3, C4, C5, C6: 1, C10: 1, C10: 2, C14: 2-OH, C16: 2-OH) were significantly different between two groups after adjusting for age and sex. The correlation analysis reported that acyl-carnitine concentrations have potential correlations with certain metabolic parameters. Our findings provide valuable new clues for exploring the roles of acyl-carnitines in the diagnosis and treatment of schizophrenia. More data and molecular biology evidences are needed to replicate our findings and elucidate relevant mechanisms.
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Affiliation(s)
- Bing Cao
- School of Psychology and Key Laboratory of Cognition and Personality (Ministry of Education), Southwest University, Chongqing 400715, China; National Demonstration Center for Experimental Psychology Education, Southwest University, Chongqing 400715, China.
| | - Yan Chen
- Dalla Lana School of Public Health, University of Toronto. 155 College St., Toronto, ON, Canada
| | - Roger S McIntyre
- Mood Disorders Psychopharmacology Unit, Toronto Western Hospital, University Health Network, Toronto, ON, Canada; Brain and Cognition Discovery Foundation, Toronto, ON, Canada
| | - Lailai Yan
- Department of Laboratorial Science and Technology, School of Public Health, Peking University, Beijing 100191, P. R. China; Medical and Health Analysis Center, Peking University, Beijing 100191, P. R. China; Vaccine Research Center, School of Public Health, Peking University, Beijing 100191, P. R. China.
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14
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Bilgiç A, Abuşoğlu S, Sadıç Çelikkol Ç, Oflaz MB, Akça ÖF, Sivrikaya A, Baysal T, Ünlü A. Altered kynurenine pathway metabolite levels in toddlers and preschool children with autism spectrum disorder. Int J Neurosci 2020; 132:826-834. [DOI: 10.1080/00207454.2020.1841187] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- Ayhan Bilgiç
- Department of Child and Adolescent Psychiatry, Meram School of Medicine, Necmettin Erbakan University, Konya, Turkey
| | - Sedat Abuşoğlu
- Department of Biochemistry, School of Medicine, Selcuk University, Konya, Turkey
| | - Çağla Sadıç Çelikkol
- Department of Child and Adolescent Psychiatry, Meram School of Medicine, Necmettin Erbakan University, Konya, Turkey
| | - Mehmet Burhan Oflaz
- Department of Pediatric Cardiology, Meram School of Medicine, Necmettin Erbakan University, Konya, Turkey
| | - Ömer Faruk Akça
- Department of Child and Adolescent Psychiatry, Meram School of Medicine, Necmettin Erbakan University, Konya, Turkey
| | - Abdullah Sivrikaya
- Department of Biochemistry, School of Medicine, Selcuk University, Konya, Turkey
| | - Tamer Baysal
- Department of Pediatric Cardiology, Meram School of Medicine, Necmettin Erbakan University, Konya, Turkey
| | - Ali Ünlü
- Department of Biochemistry, School of Medicine, Selcuk University, Konya, Turkey
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15
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Klausing AD, Fukuwatari T, Bucci DJ, Schwarcz R. Stress-induced impairment in fear discrimination is causally related to increased kynurenic acid formation in the prefrontal cortex. Psychopharmacology (Berl) 2020; 237:1931-1941. [PMID: 32215686 PMCID: PMC7308198 DOI: 10.1007/s00213-020-05507-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Accepted: 03/10/2020] [Indexed: 12/11/2022]
Abstract
RATIONALE Stress is related to cognitive impairments which are observed in most major brain diseases. Prior studies showed that the brain concentration of the tryptophan metabolite kynurenic acid (KYNA) is modulated by stress, and that changes in cerebral KYNA levels impact cognition. However, the link between these phenomena has not been tested directly so far. OBJECTIVES To investigate a possible causal relationship between acute stress, KYNA, and fear discrimination. METHODS Adult rats were exposed to one of three acute stressors-predator odor, restraint, or inescapable foot shocks (ISS)-and KYNA in the prefrontal cortex was measured using microdialysis. Corticosterone was analyzed in a subset of rats. Another cohort underwent a fear discrimination procedure immediately after experiencing stress. Different auditory conditioned stimuli (CSs) were either paired with foot shock (CS+) or were non-reinforced (CS-). One week later, fear was assessed by re-exposing rats to each CS. Finally, to test whether stress-induced changes in KYNA causally impacted fear discrimination, a group of rats that received ISS were pre-treated with the selective KYNA synthesis inhibitor PF-04859989. RESULTS ISS caused the greatest increase in circulating corticosterone levels and raised extracellular KYNA levels by ~ 85%. The two other stressors affected KYNA much less (< 25% increase). Moreover, only rats that received ISS were unable to discriminate between CS+ and CS-. PF-04859989 abolished the stress-induced KYNA increase and also prevented the impairment in fear discrimination in animals that experienced ISS. CONCLUSIONS These findings demonstrate a causal connection between stress-induced KYNA increases and cognitive deficits. Pharmacological manipulation of KYNA synthesis therefore offers a novel approach to modulate cognitive processes in stress-related disorders.
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Affiliation(s)
- Alex D Klausing
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, 55 Wade Avenue, Baltimore, MD, 21228, USA
| | - Tsutomu Fukuwatari
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, 55 Wade Avenue, Baltimore, MD, 21228, USA
- Department of Nutrition, School of Human Cultures, The University of Shiga Prefecture, 2500 Hassaka, Hikone, Shiga, 522-8533, Japan
| | - David J Bucci
- Department of Psychological and Brain Sciences, Dartmouth College, Hanover, NH, USA
| | - Robert Schwarcz
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, 55 Wade Avenue, Baltimore, MD, 21228, USA.
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16
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The ‘Yin’ and the ‘Yang’ of the kynurenine pathway: excitotoxicity and neuroprotection imbalance in stress-induced disorders. Behav Pharmacol 2019; 30:163-186. [DOI: 10.1097/fbp.0000000000000477] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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17
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Gasperi V, Sibilano M, Savini I, Catani MV. Niacin in the Central Nervous System: An Update of Biological Aspects and Clinical Applications. Int J Mol Sci 2019; 20:ijms20040974. [PMID: 30813414 PMCID: PMC6412771 DOI: 10.3390/ijms20040974] [Citation(s) in RCA: 112] [Impact Index Per Article: 22.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Revised: 02/19/2019] [Accepted: 02/20/2019] [Indexed: 12/12/2022] Open
Abstract
Niacin (also known as "vitamin B₃" or "vitamin PP") includes two vitamers (nicotinic acid and nicotinamide) giving rise to the coenzymatic forms nicotinamide adenine dinucleotide (NAD) and nicotinamide adenine dinucleotide phosphate (NADP). The two coenzymes are required for oxidative reactions crucial for energy production, but they are also substrates for enzymes involved in non-redox signaling pathways, thus regulating biological functions, including gene expression, cell cycle progression, DNA repair and cell death. In the central nervous system, vitamin B₃ has long been recognized as a key mediator of neuronal development and survival. Here, we will overview available literature data on the neuroprotective role of niacin and its derivatives, especially focusing especially on its involvement in neurodegenerative diseases (Alzheimer's, Parkinson's, and Huntington's diseases), as well as in other neuropathological conditions (ischemic and traumatic injuries, headache and psychiatric disorders).
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Affiliation(s)
- Valeria Gasperi
- Department of Experimental Medicine, Tor Vergata University of Rome, Via Montpellier 1, 00133 Rome, Italy.
| | - Matteo Sibilano
- Department of Experimental Medicine, Tor Vergata University of Rome, Via Montpellier 1, 00133 Rome, Italy.
| | - Isabella Savini
- Department of Experimental Medicine, Tor Vergata University of Rome, Via Montpellier 1, 00133 Rome, Italy.
| | - Maria Valeria Catani
- Department of Experimental Medicine, Tor Vergata University of Rome, Via Montpellier 1, 00133 Rome, Italy.
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18
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Erhardt S, Pocivavsek A, Repici M, Liu XC, Imbeault S, Maddison DC, Thomas MAR, Smalley JL, Larsson MK, Muchowski PJ, Giorgini F, Schwarcz R. Adaptive and Behavioral Changes in Kynurenine 3-Monooxygenase Knockout Mice: Relevance to Psychotic Disorders. Biol Psychiatry 2017; 82:756-765. [PMID: 28187857 PMCID: PMC5812460 DOI: 10.1016/j.biopsych.2016.12.011] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Revised: 11/29/2016] [Accepted: 12/01/2016] [Indexed: 02/06/2023]
Abstract
BACKGROUND Kynurenine 3-monooxygenase converts kynurenine to 3-hydroxykynurenine, and its inhibition shunts the kynurenine pathway-which is implicated as dysfunctional in various psychiatric disorders-toward enhanced synthesis of kynurenic acid, an antagonist of both α7 nicotinic acetylcholine and N-methyl-D-aspartate receptors. Possibly as a result of reduced kynurenine 3-monooxygenase activity, elevated central nervous system levels of kynurenic acid have been found in patients with psychotic disorders, including schizophrenia. METHODS In the present study, we investigated adaptive-and possibly regulatory-changes in mice with a targeted deletion of Kmo (Kmo-/-) and characterized the kynurenine 3-monooxygenase-deficient mice using six behavioral assays relevant for the study of schizophrenia. RESULTS Genome-wide differential gene expression analyses in the cerebral cortex and cerebellum of these mice identified a network of schizophrenia- and psychosis-related genes, with more pronounced alterations in cerebellar tissue. Kynurenic acid levels were also increased in these brain regions in Kmo-/- mice, with significantly higher levels in the cerebellum than in the cerebrum. Kmo-/- mice exhibited impairments in contextual memory and spent less time than did controls interacting with an unfamiliar mouse in a social interaction paradigm. The mutant animals displayed increased anxiety-like behavior in the elevated plus maze and in a light/dark box. After a D-amphetamine challenge (5 mg/kg, intraperitoneal), Kmo-/- mice showed potentiated horizontal activity in the open field paradigm. CONCLUSIONS Taken together, these results demonstrate that the elimination of Kmo in mice is associated with multiple gene and functional alterations that appear to duplicate aspects of the psychopathology of several neuropsychiatric disorders.
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Affiliation(s)
- Sophie Erhardt
- Dept of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Ana Pocivavsek
- Department of Psychiatry, Maryland Psychiatric Research Center, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Mariaelena Repici
- Department of Genetics, University of Leicester, Leicester LE1 7RH, UK
| | - Xi-Cong Liu
- Dept of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Sophie Imbeault
- Dept of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Daniel C Maddison
- Department of Genetics, University of Leicester, Leicester LE1 7RH, UK
| | - Marian AR Thomas
- Department of Psychiatry, Maryland Psychiatric Research Center, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Joshua L Smalley
- Department of Genetics, University of Leicester, Leicester LE1 7RH, UK
| | - Markus K Larsson
- Dept of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | | | - Flaviano Giorgini
- Department of Genetics, University of Leicester, Leicester LE1 7RH, UK
| | - Robert Schwarcz
- Department of Psychiatry, Maryland Psychiatric Research Center, University of Maryland School of Medicine, Baltimore, Maryland.
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19
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Quantitative Analysis of Kynurenine Aminotransferase II in the Adult Rat Brain Reveals High Expression in Proliferative Zones and Corpus Callosum. Neuroscience 2017; 369:1-14. [PMID: 29126954 DOI: 10.1016/j.neuroscience.2017.11.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Revised: 10/06/2017] [Accepted: 11/01/2017] [Indexed: 12/27/2022]
Abstract
Kynurenic acid, a metabolite of the kynurenine pathway of tryptophan degradation, acts as an endogenous antagonist of alpha7 nicotinic and NMDA receptors and is implicated in a number of neurophysiological and neuropathological processes including cognition and neurodegenerative events. Therefore, kynurenine aminotransferase II (KAT II/AADAT), the enzyme responsible for the formation of the majority of neuroactive kynurenic acid in the brain, has prompted significant interest. Using immunohistochemistry, this enzyme was localized primarily in astrocytes throughout the adult rat brain, but detailed neuroanatomical studies are lacking. Here, we employed quantitative in situ hybridization to analyze the relative expression of KAT II mRNA in the brain of rats under normal conditions and 6 h after the administration of lipopolysaccharides (LPSs). Specific hybridization signals for KAT II were detected, with the highest expression in the subventricular zone (SVZ), the rostral migratory stream and the floor of the third ventricle followed by the corpus callosum and the hippocampus. This pattern of mRNA expression was paralleled by differential protein expression, determined by serial dilutions of antibodies (up to 1:1 million), and was confirmed to be primarily astrocytic in nature. The mRNA signal in the SVZ and the hippocampus was substantially increased by the LPS treatment without detectable changes elsewhere. These results demonstrate that KAT II is expressed in the rat brain in a region-specific manner and that gene expression is sensitive to inflammatory processes. This suggests an unrecognized role for kynurenic acid in the brain's germinal zones.
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20
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Oxenkrug G, van der Hart M, Roeser J, Summergrad P. Peripheral kynurenine-3-monooxygenase deficiency as a potential risk factor for metabolic syndrome in schizophrenia patients. ACTA ACUST UNITED AC 2017; 1. [PMID: 28748226 PMCID: PMC5523985 DOI: 10.15761/icm.1000105] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Increased predisposition of schizophrenia patients (SP) to development of obesity and insulin resistance suggested common signaling pathway between metabolic syndrome (MetS) and schizophrenia. Deficiency of kynurenine-3-monooxygenase (KMO), enzyme catalyzing formation of 3-hydroxykynurenine (3-HK) from kynurenine (Kyn), a tryptophan (Trp) metabolite, might contribute to development of MetS as suggested by non-expression of KMO genes in human fat tissue and elevated serum concentrations of Kyn and its metabolites, kynurenic (KYNA) and anthranilic (ANA) acids, in diabetic patients and Zucker fatty rats (ZFR). Markers of KMO deficiency: decreased 3-HK and elevated Kyn, KYNA and ANA, were observed in brains and spinal fluids of SP, and in brains and serum of experimental animals with genetically- or pharmacologically-induced KMO deficiency. However, elevated concentrations of ANA and decreased 3-HK were reported in serum of SP without concurrent increase of Kyn and KYNA. Present study aimed to re-assess serum Kyn metabolites (HPLC-MS) in a sub-group of SP with elevated KYNA. We found increased Kyn concentrations (by 30%) and Kyn:Trp ratio (by 20%) in serum of SP with elevated KYNA concentrations (by 40%). Obtained results and our previous data suggest that peripheral KMO deficiency might be manifested by, at least, two different patterns: elevated ANA with decreased 3-HK; and elevated KYNA and KYN. The latter pattern was previously described in type 2 diabetes patients and might underline increased predisposition of SP to development of MetS. Assessment of peripheral KMO deficiency might identify SP predisposed to MetS. Attenuation of the consequences of peripheral KMO deficiency might be a new target for prevention/treatment of obesity and diabetes in SP.
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Affiliation(s)
- Gregory Oxenkrug
- Department of Psychiatry, Tufts University School of Medicine, USA
| | | | | | - Paul Summergrad
- Department of Psychiatry, Tufts University School of Medicine, USA
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21
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Sigitova E, Fišar Z, Hroudová J, Cikánková T, Raboch J. Biological hypotheses and biomarkers of bipolar disorder. Psychiatry Clin Neurosci 2017; 71:77-103. [PMID: 27800654 DOI: 10.1111/pcn.12476] [Citation(s) in RCA: 141] [Impact Index Per Article: 20.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2016] [Revised: 10/04/2016] [Accepted: 10/25/2016] [Indexed: 02/06/2023]
Abstract
The most common mood disorders are major depressive disorders and bipolar disorders (BD). The pathophysiology of BD is complex, multifactorial, and not fully understood. Creation of new hypotheses in the field gives impetus for studies and for finding new biomarkers for BD. Conversely, new biomarkers facilitate not only diagnosis of a disorder and monitoring of biological effects of treatment, but also formulation of new hypotheses about the causes and pathophysiology of the BD. BD is characterized by multiple associations between disturbed brain development, neuroplasticity, and chronobiology, caused by: genetic and environmental factors; defects in apoptotic, immune-inflammatory, neurotransmitter, neurotrophin, and calcium-signaling pathways; oxidative and nitrosative stress; cellular bioenergetics; and membrane or vesicular transport. Current biological hypotheses of BD are summarized, including related pathophysiological processes and key biomarkers, which have been associated with changes in genetics, systems of neurotransmitter and neurotrophic factors, neuroinflammation, autoimmunity, cytokines, stress axis activity, chronobiology, oxidative stress, and mitochondrial dysfunctions. Here we also discuss the therapeutic hypotheses and mechanisms of the switch between depressive and manic state.
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Affiliation(s)
- Ekaterina Sigitova
- Department of Psychiatry, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic
| | - Zdeněk Fišar
- Department of Psychiatry, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic
| | - Jana Hroudová
- Department of Psychiatry, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic
| | - Tereza Cikánková
- Department of Psychiatry, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic
| | - Jiří Raboch
- Department of Psychiatry, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic
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22
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Clark SM, Pocivavsek A, Nicholson JD, Notarangelo FM, Langenberg P, McMahon RP, Kleinman JE, Hyde TM, Stiller J, Postolache TT, Schwarcz R, Tonelli LH. Reduced kynurenine pathway metabolism and cytokine expression in the prefrontal cortex of depressed individuals. J Psychiatry Neurosci 2016; 41:386-394. [PMID: 27070351 PMCID: PMC5082509 DOI: 10.1503/jpn.150226] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Neuroinflammatory processes are increasingly believed to participate in the pathophysiology of a number of major psychiatric diseases, including depression. Immune activation stimulates the conversion of the amino acid tryptophan to kynurenine, leading to the formation of neuroactive metabolites, such as quinolinic acid and kynurenic acid. These compounds affect glutamatergic neurotransmission, which plays a prominent role in depressive pathology. Increased tryptophan degradation along the kynurenine pathway (KP) has been proposed to contribute to disease etiology. METHODS We used postmortem brain tissue from the ventrolateral prefrontal cortex (VLPFC) to assess tissue levels of tryptophan and KP metabolites, the expression of several KP enzymes and a series of cytokines as well as tissue pathology, including microglial activation. Tissue samples came from nonpsychiatric controls (n = 36) and individuals with depressive disorder not otherwise specified (DD-NOS, n = 45) who died of natural causes, homicide, accident, or suicide. RESULTS We found a reduction in the enzymatic conversion of tryptophan to kynurenine, determined using the kynurenine:tryptophan ratio, and reduced messenger RNA expression of the enzymes indoleamine-2,3-dioxygenase 1 and 2 and tryptophan-2,3-dioxygenase in depressed individuals irrespective of the cause of death. These findings correlated with reductions in the expression of several cytokines, including interferon-γ and tumour necrosis factor-α. Notably, quinolinic acid levels were also lower in depressed individuals than controls. LIMITATIONS Information on the use of antidepressants and other psychotropic medications was insufficient for statistical comparisons. CONCLUSION Contrary to expectations, the present results indicate that depression, in the absence of medical illness or an overt inflammatory process, is associated with compromised, rather than increased, KP metabolism in the VLPFC.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | - Leonardo H. Tonelli
- Correspondence to: L.H. Tonelli, Laboratory of Behavioral Neuroimmunology, Department of Psychiatry, University of Maryland School of Medicine, 655 W. Baltimore St. Baltimore MD, 21201, USA;
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23
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Faa G, Manchia M, Pintus R, Gerosa C, Marcialis MA, Fanos V. Fetal programming of neuropsychiatric disorders. ACTA ACUST UNITED AC 2016; 108:207-223. [DOI: 10.1002/bdrc.21139] [Citation(s) in RCA: 89] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Accepted: 09/28/2016] [Indexed: 12/14/2022]
Affiliation(s)
- Gavino Faa
- Division of Pathology, Department of Surgery; University Hospital San Giovanni di Dio; Cagliari Italy
| | - Mirko Manchia
- Section of Psychiatry, Department of Public Health, Clinical and Molecular Medicine; University of Cagliari; Cagliari Italy
- Department of Pharmacology; Dalhousie University; Halifax Nova Scotia Canada
| | - Roberta Pintus
- Neonatal Intensive Care Unit, Neonatal Pathology and Neonatal Section; AOU Cagliari and University of Cagliari; Cagliari Italy
| | - Clara Gerosa
- Division of Pathology, Department of Surgery; University Hospital San Giovanni di Dio; Cagliari Italy
| | - Maria Antonietta Marcialis
- Neonatal Intensive Care Unit, Neonatal Pathology and Neonatal Section; AOU Cagliari and University of Cagliari; Cagliari Italy
| | - Vassilios Fanos
- Neonatal Intensive Care Unit, Neonatal Pathology and Neonatal Section; AOU Cagliari and University of Cagliari; Cagliari Italy
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24
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Badawy AAB, Bano S. Tryptophan Metabolism in Rat Liver After Administration of Tryptophan, Kynurenine Metabolites, and Kynureninase Inhibitors. Int J Tryptophan Res 2016; 9:51-65. [PMID: 27547037 PMCID: PMC4982523 DOI: 10.4137/ijtr.s38190] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Revised: 07/18/2016] [Accepted: 07/19/2016] [Indexed: 01/03/2023] Open
Abstract
Rat liver tryptophan (Trp), kynurenine pathway metabolites, and enzymes deduced from product/substrate ratios were assessed following acute and/or chronic administration of kynurenic acid (KA), 3-hydroxykynurenine (3-HK), 3-hydroxyanthranilic acid (3-HAA), Trp, and the kynureni-nase inhibitors benserazide (BSZ) and carbidopa (CBD). KA activated Trp 2,3-dioxygenase (TDO), possibly by increasing liver 3-HAA, but inhibited kynurenine aminotransferase (KAT) and kynureninase activities with 3-HK as substrate. 3-HK inhibited kynureninase activity from 3-HK. 3-HAA stimulated TDO, but inhibited kynureninase activity from K and 3-HK. Trp (50 mg/kg) increased kynurenine metabolite concentrations and KAT from K, and exerted a temporary stimulation of TDO. The kynureninase inhibitors BSZ and CBD also inhibited KAT, but stimulated TDO. BSZ abolished or strongly inhibited the Trp-induced increases in liver Trp and kynurenine metabolites. The potential effects of these changes in conditions of immune activation, schizophrenia, and other disease states are discussed.
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Affiliation(s)
- Abdulla A-B Badawy
- School of Health Sciences, Cardiff Metropolitan University, Cardiff, Wales, UK
| | - Samina Bano
- School of Health Sciences, Cardiff Metropolitan University, Cardiff, Wales, UK.; Present address: Department of Biochemistry, University of Karachi, Karachi, Pakistan
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25
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Abstract
Tryptophan-2, 3-dioxygenase (TDO) is a heme-containing protein catalyzing the first reaction in the kynurenine pathway, which incorporates oxygen into the indole moiety of tryptophan and catalyzes it into kynurenine (KYN). The activation of TDO results in the depletion of tryptophan and the accumulation of kynurenine and its metabolites. These metabolites can affect the function of neurons and inhibit the proliferation of T cells. Increasing evidence demonstrates that TDO is a potential therapeutic target in the treatment of brain diseases as well as in the antitumor and transplant fields. Despite its growing popularity, there are few reviews only focusing on TDO. Hence, we herein review TDO by providing a comprehensive overview of TDO, including its biological functions as well as the evolution, structure and catalytic process of TDO. Additionally, this review will focus on the role of TDO in the pathology of three groups of brain diseases: Schizophrenia, Alzheimer's disease (AD) and Glioma. Finally, we will also provide an opinion regarding the future developmental directions of TDO in brain diseases, especially whether TDO has a potential role in other brain diseases as well as the development and applications of TDO inhibitors as treatments.
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Affiliation(s)
- Cheng-Peng Yu
- The Second Clinic Medical College, School of Medicine, Nanchang University, Nanchang, China
| | - Ze-Zheng Pan
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Nanchang University, Nanchang, China
| | - Da-Ya Luo
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Nanchang University, Nanchang, China.
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Ascoli BM, Géa LP, Colombo R, Barbé-Tuana FM, Kapczinski F, Rosa AR. The role of macrophage polarization on bipolar disorder: Identifying new therapeutic targets. Aust N Z J Psychiatry 2016; 50:618-30. [PMID: 27091850 DOI: 10.1177/0004867416642846] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE Bipolar disorder is a chronic, severe and disabling disease; however, its pathophysiology remains poorly understood. Recent evidence has suggested that inflammation and immune dysregulation play a significant role in the pathophysiology of bipolar disorder. This review is aimed to highlight the importance of systemic inflammation in modulating the inflammatory response of microglia and hence its potential involvement with bipolar disorder. We also discuss novel therapeutic strategies that emerge from this new research. METHOD This article presents a theoretical synthesis of the effects of systemic inflammation on the immune response of the central nervous system in bipolar disorder. The complex relationship between stress, pro-inflammatory cytokines and microglial dysfunction is summarized, emphasizing the role of the kynurenine pathway in this process and, consequently, their effects on neuronal plasticity. RESULTS Bipolar patients demonstrate increased serum levels of pro-inflammatory cytokines (interleukin-1β, interleukin-6 and tumor necrosis factor-α) and lower hypothalamic-pituitary-adrenal axis sensitivity. This imbalance in the immune system promotes a change in blood-brain barrier permeability, leading to an inflammatory signal spread in the central nervous system from the periphery, through macrophages activation (M1 polarization). Chronic microglial activation can result in neuronal apoptosis, neurogenesis inhibition, hippocampal volume reduction, lower neurotransmitters synthesis and cytotoxicity, by increasing glutamate production and kynurenine metabolism. CONCLUSIONS This review provides an overview of the mechanisms involved in the immune system imbalance and its potential involvement in the pathophysiology of bipolar disorder. Consequently, new strategies that normalize the immune-inflammatory pathways may provide a valuable therapeutic target for the treatment of these disorders.
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Affiliation(s)
- Bruna M Ascoli
- Laboratory of Molecular Psychiatry, Hospital de Clínicas de Porto Alegre (HCPA), Porto Alegre, Brazil Postgraduate Program in Psychiatry and Behavioral Science, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
| | - Luiza P Géa
- Laboratory of Molecular Psychiatry, Hospital de Clínicas de Porto Alegre (HCPA), Porto Alegre, Brazil Postgraduate Program in Pharmacology and Therapeutics, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
| | - Rafael Colombo
- Laboratory of Molecular Psychiatry, Hospital de Clínicas de Porto Alegre (HCPA), Porto Alegre, Brazil Laboratory of Pharmacology and Physiology, Universidade de Caxias do Sul (UCS), Caxias do Sul, Brazil
| | - Florência M Barbé-Tuana
- Laboratory of Molecular Biology and Bioinformatics, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil Postgraduate Program in Biochemistry, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
| | - Flávio Kapczinski
- Laboratory of Molecular Psychiatry, Hospital de Clínicas de Porto Alegre (HCPA), Porto Alegre, Brazil Postgraduate Program in Psychiatry and Behavioral Science, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil Department of Psychiatry, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
| | - Adriane Ribeiro Rosa
- Laboratory of Molecular Psychiatry, Hospital de Clínicas de Porto Alegre (HCPA), Porto Alegre, Brazil Postgraduate Program in Psychiatry and Behavioral Science, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil Postgraduate Program in Pharmacology and Therapeutics, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil Department of Pharmacology, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
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Young JJ, Silber T, Bruno D, Galatzer-Levy IR, Pomara N, Marmar CR. Is there Progress? An Overview of Selecting Biomarker Candidates for Major Depressive Disorder. Front Psychiatry 2016; 7:72. [PMID: 27199779 PMCID: PMC4843170 DOI: 10.3389/fpsyt.2016.00072] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Accepted: 04/11/2016] [Indexed: 01/01/2023] Open
Abstract
Major depressive disorder (MDD) contributes to a significant worldwide disease burden, expected to be second only to heart disease by 2050. However, accurate diagnosis has been a historical weakness in clinical psychiatry. As a result, there is a demand for diagnostic modalities with greater objectivity that could improve on current psychiatric practice that relies mainly on self-reporting of symptoms and clinical interviews. Over the past two decades, literature on a growing number of putative biomarkers for MDD increasingly suggests that MDD patients have significantly different biological profiles compared to healthy controls. However, difficulty in elucidating their exact relationships within depression pathology renders individual markers inconsistent diagnostic tools. Consequently, further biomarker research could potentially improve our understanding of MDD pathophysiology as well as aid in interpreting response to treatment, narrow differential diagnoses, and help refine current MDD criteria. Representative of this, multiplex assays using multiple sources of biomarkers are reported to be more accurate options in comparison to individual markers that exhibit lower specificity and sensitivity, and are more prone to confounding factors. In the future, more sophisticated multiplex assays may hold promise for use in screening and diagnosing depression and determining clinical severity as an advance over relying solely on current subjective diagnostic criteria. A pervasive limitation in existing research is heterogeneity inherent in MDD studies, which impacts the validity of biomarker data. Additionally, small sample sizes of most studies limit statistical power. Yet, as the RDoC project evolves to decrease these limitations, and stronger studies with more generalizable data are developed, significant advances in the next decade are expected to yield important information in the development of MDD biomarkers for use in clinical settings.
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Affiliation(s)
- Juan Joseph Young
- Nathan Kline Institute, Orangeburg, NY, USA; Case Western Reserve University, Cleveland, OH, USA; MetroHealth Medical Center, Cleveland, OH, USA
| | - Tim Silber
- Nathan Kline Institute , Orangeburg, NY , USA
| | - Davide Bruno
- Liverpool John Moores University , Liverpool , UK
| | | | - Nunzio Pomara
- Nathan Kline Institute, Orangeburg, NY, USA; New York University School of Medicine, New York, NY, USA; NYU Cohen Veterans Center, New York, NY, USA
| | - Charles Raymond Marmar
- New York University School of Medicine, New York, NY, USA; NYU Cohen Veterans Center, New York, NY, USA
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Curto M, Lionetto L, Fazio F, Mitsikostas DD, Martelletti P. Fathoming the kynurenine pathway in migraine: why understanding the enzymatic cascades is still critically important. Intern Emerg Med 2015; 10:413-21. [PMID: 25708356 DOI: 10.1007/s11739-015-1208-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2014] [Accepted: 01/27/2015] [Indexed: 12/11/2022]
Abstract
Kynurenine pathway, the quantitatively main branch of tryptophan metabolism, has been long been considered a source of nicotinamide adenine dinucleotide, although several of its products, the so-called kynurenines, are endowed with the capacity to activate glutamate receptors, thus potentially influencing a large group of functions in the central nervous system (CNS). Migraine, a largely unknown pathology, is strictly related to the glutamate system in the CNS pathologic terms. Despite the large number of studies conducted on migraine etio-pathology, the kynurenine pathway has been only recently linked to this disease. Nonetheless, some evidence suggests an intriguing role for some kynurenines, and an exploratory study on the serum kynurenine level might be helpful to better understand possible alterations of the kynurenine pathway in patients suffering from migraine.
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Affiliation(s)
- Martina Curto
- Psychiatric Unit, Neurosciences, Mental Health and Sensory Organs (NESMOS) Department, Sant'Andrea Hospital, Sapienza University of Rome, Rome, Italy
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Miller CL. The chemical interaction between adrenochrome, three different classes of antipsychotic drugs and metabolites of the kynurenine pathway. Eur Neuropsychopharmacol 2015; 25:435-40. [PMID: 25554565 DOI: 10.1016/j.euroneuro.2014.12.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/24/2014] [Revised: 11/03/2014] [Accepted: 12/08/2014] [Indexed: 11/27/2022]
Abstract
Two kynurenine metabolites, 3-hydroxykynurenine and 3-hydroxyanthranilic acid, are known to inhibit melanin polymer formation in in vitro reactions catalyzed by tyrosinase. The present study expands that finding to include inhibition of chlorpromazine-stimulated melanin formation from the endogenous melanin precursor adrenochrome. Several kynurenine pathway metabolites tested had no measurable effect on the reaction: tryptophan, kynurenine, kynurenic acid, quinolinic acid and nicotinic acid. However, at a concentration of 0.5mM in a pH 7.4 reaction mix, 3-hydroxykynurenine exerted~72% inhibition on product formation and the same concentration of 3-hydroxyanthranilic acid caused complete inhibition. Two other classes of antipsychotic drugs were evaluated in this paradigm, represented by olanzapine and minocycline. Although the adrenochrome reaction of both drugs was strongly inhibited by 3-hydroxyanthranilic acid, 3-hydroxykynurenine inhibited product formation from only the minocycline reaction. The results are discussed in terms of the well-studied kynurenine pathway upregulation in psychotic disorders and how such upregulation may either influence the efficacy of antipsychotic drug treatment or relate to the mechanism of action of these drugs.
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Kubesova A, Tejkalova H, Syslova K, Kacer P, Vondrousova J, Tyls F, Fujakova M, Palenicek T, Horacek J. Biochemical, histopathological and morphological profiling of a rat model of early immune stimulation: relation to psychopathology. PLoS One 2015; 10:e0115439. [PMID: 25602957 PMCID: PMC4300081 DOI: 10.1371/journal.pone.0115439] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2014] [Accepted: 11/24/2014] [Indexed: 12/30/2022] Open
Abstract
Perinatal immune challenge leads to neurodevelopmental dysfunction, permanent immune dysregulation and abnormal behaviour, which have been shown to have translational validity to findings in human neuropsychiatric disorders (e.g. schizophrenia, mood and anxiety disorders, autism, Parkinson’s disease and Alzheimer’s disease). The aim of this animal study was to elucidate the influence of early immune stimulation triggered by systemic postnatal lipopolysaccharide administration on biochemical, histopathological and morphological measures, which may be relevant to the neurobiology of human psychopathology. In the present study of adult male Wistar rats we examined the brain and plasma levels of monoamines (dopamine, serotonin), their metabolites, the levels of the main excitatory and inhibitory neurotransmitters glutamate and γ-aminobutyric acid and the levels of tryptophan and its metabolites from the kynurenine catabolic pathway. Further, we focused on histopathological and morphological markers related to pathogenesis of brain diseases - glial cell activation, neurodegeneration, hippocampal volume reduction and dopaminergic synthesis in the substantia nigra. Our results show that early immune stimulation in adult animals alters the levels of neurotransmitters and their metabolites, activates the kynurenine pathway of tryptophan metabolism and leads to astrogliosis, hippocampal volume reduction and a decrease of tyrosine hydroxylase immunoreactivity in the substantia nigra. These findings support the crucial pathophysiological role of early immune stimulation in the above mentioned neuropsychiatric disorders.
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Affiliation(s)
- Anna Kubesova
- Prague Psychiatric Center, Prague, Czech Republic
- National Institute of Mental Health, Klecany, Czech Republic
- Third Faculty of Medicine, Charles University, Prague, Czech Republic
- * E-mail:
| | - Hana Tejkalova
- Prague Psychiatric Center, Prague, Czech Republic
- National Institute of Mental Health, Klecany, Czech Republic
| | - Kamila Syslova
- Institute of Chemical Technology, Prague, Czech Republic
| | - Petr Kacer
- Institute of Chemical Technology, Prague, Czech Republic
| | | | - Filip Tyls
- Prague Psychiatric Center, Prague, Czech Republic
- National Institute of Mental Health, Klecany, Czech Republic
- Third Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Michaela Fujakova
- Prague Psychiatric Center, Prague, Czech Republic
- National Institute of Mental Health, Klecany, Czech Republic
- Third Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Tomas Palenicek
- Prague Psychiatric Center, Prague, Czech Republic
- National Institute of Mental Health, Klecany, Czech Republic
- Third Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Jiri Horacek
- Prague Psychiatric Center, Prague, Czech Republic
- National Institute of Mental Health, Klecany, Czech Republic
- Third Faculty of Medicine, Charles University, Prague, Czech Republic
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DeAngeli NE, Todd TP, Chang SE, Yeh HH, Yeh PW, Bucci DJ. Exposure to Kynurenic Acid during Adolescence Increases Sign-Tracking and Impairs Long-Term Potentiation in Adulthood. Front Behav Neurosci 2015; 8:451. [PMID: 25610382 PMCID: PMC4285091 DOI: 10.3389/fnbeh.2014.00451] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2014] [Accepted: 12/16/2014] [Indexed: 11/21/2022] Open
Abstract
Changes in brain reward systems are thought to contribute significantly to the cognitive and behavioral impairments of schizophrenia, as well as the propensity to develop co-occurring substance abuse disorders. Presently, there are few treatments for persons with a dual diagnosis and little is known about the neural substrates that underlie co-occurring schizophrenia and substance abuse. One goal of the present study was to determine if a change in the concentration of kynurenic acid (KYNA), a tryptophan metabolite that is increased in the brains of people with schizophrenia, affects reward-related behavior. KYNA is an endogenous antagonist of NMDA glutamate receptors and α7 nicotinic acetylcholine receptors, both of which are critically involved in neurodevelopment, plasticity, and behavior. In Experiment 1, rats were treated throughout adolescence with L-kynurenine (L-KYN), the precursor of KYNA. As adults, the rats were tested drug-free in an autoshaping procedure in which a lever was paired with food. Rats treated with L-KYN during adolescence exhibited increased sign-tracking behavior (lever pressing) when they were tested as adults. Sign-tracking is thought to reflect the lever acquiring incentive salience (motivational value) as a result of its pairing with reward. Thus, KYNA exposure may increase the incentive salience of cues associated with reward, perhaps contributing to an increase in sensitivity to drug-related cues in persons with schizophrenia. In Experiment 2, we tested the effects of exposure to KYNA during adolescence on hippocampal long-term potentiation (LTP). Rats treated with L-KYN exhibited no LTP after a burst of high-frequency stimulation that was sufficient to produce robust LTP in vehicle-treated rats. This finding represents the first demonstrated consequence of elevated KYNA concentration during development and provides insight into the basis for cognitive and behavioral deficits that result from exposure to KYNA during adolescence.
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Affiliation(s)
- Nicole E DeAngeli
- Department of Psychological and Brain Sciences, Dartmouth College , Hanover, NH , USA
| | - Travis P Todd
- Department of Psychological and Brain Sciences, Dartmouth College , Hanover, NH , USA
| | - Stephen E Chang
- Department of Psychological and Brain Sciences, Dartmouth College , Hanover, NH , USA
| | - Hermes H Yeh
- Department of Physiology and Neurobiology, Geisel School of Medicine, Dartmouth College , Hanover, NH , USA
| | - Pamela W Yeh
- Department of Physiology and Neurobiology, Geisel School of Medicine, Dartmouth College , Hanover, NH , USA
| | - David J Bucci
- Department of Psychological and Brain Sciences, Dartmouth College , Hanover, NH , USA
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Brand SJ, Moller M, Harvey BH. A Review of Biomarkers in Mood and Psychotic Disorders: A Dissection of Clinical vs. Preclinical Correlates. Curr Neuropharmacol 2015; 13:324-68. [PMID: 26411964 PMCID: PMC4812797 DOI: 10.2174/1570159x13666150307004545] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Revised: 02/04/2015] [Accepted: 03/06/2015] [Indexed: 11/23/2022] Open
Abstract
Despite significant research efforts aimed at understanding the neurobiological underpinnings of mood (depression, bipolar disorder) and psychotic disorders, the diagnosis and evaluation of treatment of these disorders are still based solely on relatively subjective assessment of symptoms as well as psychometric evaluations. Therefore, biological markers aimed at improving the current classification of psychotic and mood-related disorders, and that will enable patients to be stratified on a biological basis into more homogeneous clinically distinct subgroups, are urgently needed. The attainment of this goal can be facilitated by identifying biomarkers that accurately reflect pathophysiologic processes in these disorders. This review postulates that the field of psychotic and mood disorder research has advanced sufficiently to develop biochemical hypotheses of the etiopathology of the particular illness and to target the same for more effective disease modifying therapy. This implies that a "one-size fits all" paradigm in the treatment of psychotic and mood disorders is not a viable approach, but that a customized regime based on individual biological abnormalities would pave the way forward to more effective treatment. In reviewing the clinical and preclinical literature, this paper discusses the most highly regarded pathophysiologic processes in mood and psychotic disorders, thereby providing a scaffold for the selection of suitable biomarkers for future studies in this field, to develope biomarker panels, as well as to improve diagnosis and to customize treatment regimens for better therapeutic outcomes.
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Affiliation(s)
| | | | - Brian H Harvey
- Division of Pharmacology and Center of Excellence for Pharmaceutical Sciences, School of Pharmacy, North-West University, Potchefstroom, South Africa.
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Zheng X, Demirci FY, Barmada MM, Richardson GA, Lopez OL, Sweet RA, Kamboh MI, Feingold E. A rare duplication on chromosome 16p11.2 is identified in patients with psychosis in Alzheimer's disease. PLoS One 2014; 9:e111462. [PMID: 25379732 PMCID: PMC4224411 DOI: 10.1371/journal.pone.0111462] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2014] [Accepted: 09/29/2014] [Indexed: 01/10/2023] Open
Abstract
Epidemiological and genetic studies suggest that schizophrenia and autism may share genetic links. Besides common single nucleotide polymorphisms, recent data suggest that some rare copy number variants (CNVs) are risk factors for both disorders. Because we have previously found that schizophrenia and psychosis in Alzheimer's disease (AD+P) share some genetic risk, we investigated whether CNVs reported in schizophrenia and autism are also linked to AD+P. We searched for CNVs associated with AD+P in 7 recurrent CNV regions that have been previously identified across autism and schizophrenia, using the Illumina HumanOmni1-Quad BeadChip. A chromosome 16p11.2 duplication CNV (chr16: 29,554,843-30,105,652) was identified in 2 of 440 AD+P subjects, but not in 136 AD subjects without psychosis, or in 593 AD subjects with intermediate psychosis status, or in 855 non-AD individuals. The frequency of this duplication CNV in AD+P (0.46%) was similar to that reported previously in schizophrenia (0.46%). This duplication CNV was further validated using the NanoString nCounter CNV Custom CodeSets. The 16p11.2 duplication has been associated with developmental delay, intellectual disability, behavioral problems, autism, schizophrenia (SCZ), and bipolar disorder. These two AD+P patients had no personal of, nor any identified family history of, SCZ, bipolar disorder and autism. To the best of our knowledge, our case report is the first suggestion that 16p11.2 duplication is also linked to AD+P. Although rare, this CNV may have an important role in the development of psychosis.
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Affiliation(s)
- Xiaojing Zheng
- Department of Biostatistics, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- Department of Pediatrics, School of Medicine, University of North Carolina, Chapel Hill, North Carolina, United States of America
- * E-mail:
| | - F. Yesim Demirci
- Department of Human Genetics, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - M. Michael Barmada
- Department of Human Genetics, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Gale A. Richardson
- Department of Psychiatry, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Oscar L. Lopez
- Department of Neurology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- VISN 4 Mental Illness Research, Education and Clinical Center, VA Pittsburgh Healthcare System, Pittsburgh, Pennsylvania, United States of America
| | - Robert A. Sweet
- Department of Psychiatry, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- Department of Neurology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- VISN 4 Mental Illness Research, Education and Clinical Center, VA Pittsburgh Healthcare System, Pittsburgh, Pennsylvania, United States of America
| | - M. Ilyas Kamboh
- Department of Human Genetics, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- Department of Psychiatry, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- VISN 4 Mental Illness Research, Education and Clinical Center, VA Pittsburgh Healthcare System, Pittsburgh, Pennsylvania, United States of America
| | - Eleanor Feingold
- Department of Biostatistics, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- Department of Human Genetics, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
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Inhibition of stress-induced hepatic tryptophan 2,3-dioxygenase exhibits antidepressant activity in an animal model of depressive behaviour. Int J Neuropsychopharmacol 2014; 17:917-28. [PMID: 24472498 DOI: 10.1017/s1461145713001673] [Citation(s) in RCA: 75] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
The role of hepatic tryptophan 2,3 dioxygenase (TDO) was assessed in the provocation of stress-induced depression-related behaviour in the rat. TDO drives tryptophan metabolism via the kynurenine pathway (KP) and leads to the production of neuroactive metabolites including kynurenine. A single 2 h period of restraint stress in adult male Sprague-Dawley rats provoked an increase in circulating concentrations of the glucocorticoid corticosterone and induction of hepatic TDO expression and activity. Repeated exposure to stress (10 d of 2 h restraint each day) provoked an increase in immobility in the forced swimming test (FST) indicative of depression-related behaviour. Immobility was accompanied by an increase in the circulating corticosterone concentrations, expression and activity of hepatic TDO and increase in the expression of TDO in the cerebral cortex. Increased TDO activity was associated with raised circulating kynurenine concentrations and a reduction in circulating tryptophan concentrations indicative of KP activation. Co-treatment with the TDO inhibitor allopurinol (20 mg/kg, i.p.), attenuated the chronic stress-related increase in immobility in the FST and the accompanying increase in circulating kynurenine concentrations. These findings indicate that stress-induced corticosterone and consequent activation of hepatic TDO, tryptophan metabolism and production of kynurenine provoke a depression-related behavioural phenotype. Inhibition of stress-related hepatic TDO activity promotes antidepressant activity. TDO may therefore represent a promising target for the treatment of depression associated with stress-related disorders in which there is evidence for KP activation.
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The theory of bipolar disorder as an illness of accelerated aging: Implications for clinical care and research. Neurosci Biobehav Rev 2014; 42:157-69. [DOI: 10.1016/j.neubiorev.2014.02.004] [Citation(s) in RCA: 122] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2013] [Revised: 12/17/2013] [Accepted: 02/05/2014] [Indexed: 12/20/2022]
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Watkins CC, Sawa A, Pomper MG. Glia and immune cell signaling in bipolar disorder: insights from neuropharmacology and molecular imaging to clinical application. Transl Psychiatry 2014; 4:e350. [PMID: 24448212 PMCID: PMC3905229 DOI: 10.1038/tp.2013.119] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2013] [Revised: 10/28/2013] [Accepted: 11/07/2013] [Indexed: 12/27/2022] Open
Abstract
Bipolar disorder (BD) is a debilitating mental illness characterized by severe fluctuations in mood, sleep, energy and executive functioning. Pharmacological studies of selective serotonin reuptake inhibitors and the monoamine system have helped us to clinically understand bipolar depression. Mood stabilizers such as lithium and valproic acid, the first-line treatments for bipolar mania and depression, inhibit glycogen synthase kinase-3 beta (GSK-3β) and regulate the Wnt pathway. Recent investigations suggest that microglia, the resident immune cells of the brain, provide a physiological link between the serotonin system and the GSK-3β/Wnt pathway through neuroinflammation. We review the pharmacological, translational and brain imaging studies that support a role for microglia in regulating neurotransmitter synthesis and immune cell activation. These investigations provide a model for microglia involvement in the pathophysiology and phenotype of BD that may translate into improved therapies.
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Affiliation(s)
- C C Watkins
- Department of Psychiatry and Behavioral Sciences, John Hopkins University School of Medicine, Baltimore, MD, USA,Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, 600 North Wolfe Street, Phipps 300, Baltimore, MD 21287-0005, USA. E-mail:
| | - A Sawa
- Department of Psychiatry and Behavioral Sciences, John Hopkins University School of Medicine, Baltimore, MD, USA
| | - M G Pomper
- Department of Psychiatry and Behavioral Sciences, John Hopkins University School of Medicine, Baltimore, MD, USA,Division of Neuroradiology, Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
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Giorgini F, Huang SY, Sathyasaikumar KV, Notarangelo FM, Thomas MAR, Tararina M, Wu HQ, Schwarcz R, Muchowski PJ. Targeted deletion of kynurenine 3-monooxygenase in mice: a new tool for studying kynurenine pathway metabolism in periphery and brain. J Biol Chem 2013; 288:36554-66. [PMID: 24189070 DOI: 10.1074/jbc.m113.503813] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Kynurenine 3-monooxygenase (KMO), a pivotal enzyme in the kynurenine pathway (KP) of tryptophan degradation, has been suggested to play a major role in physiological and pathological events involving bioactive KP metabolites. To explore this role in greater detail, we generated mice with a targeted genetic disruption of Kmo and present here the first biochemical and neurochemical characterization of these mutant animals. Kmo(-/-) mice lacked KMO activity but showed no obvious abnormalities in the activity of four additional KP enzymes tested. As expected, Kmo(-/-) mice showed substantial reductions in the levels of its enzymatic product, 3-hydroxykynurenine, in liver, brain, and plasma. Compared with wild-type animals, the levels of the downstream metabolite quinolinic acid were also greatly decreased in liver and plasma of the mutant mice but surprisingly were only slightly reduced (by ∼20%) in the brain. The levels of three other KP metabolites: kynurenine, kynurenic acid, and anthranilic acid, were substantially, but differentially, elevated in the liver, brain, and plasma of Kmo(-/-) mice, whereas the liver and brain content of the major end product of the enzymatic cascade, NAD(+), did not differ between Kmo(-/-) and wild-type animals. When assessed by in vivo microdialysis, extracellular kynurenic acid levels were found to be significantly elevated in the brains of Kmo(-/-) mice. Taken together, these results provide further evidence that KMO plays a key regulatory role in the KP and indicate that Kmo(-/-) mice will be useful for studying tissue-specific functions of individual KP metabolites in health and disease.
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Affiliation(s)
- Flaviano Giorgini
- From the Department of Genetics, University of Leicester, Leicester LE1 7RH, United Kingdom
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Activation of kynurenine pathway in ex vivo fibroblasts from patients with bipolar disorder or schizophrenia: cytokine challenge increases production of 3-hydroxykynurenine. J Psychiatr Res 2013; 47:1815-23. [PMID: 24012176 DOI: 10.1016/j.jpsychires.2013.08.008] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2013] [Revised: 08/10/2013] [Accepted: 08/14/2013] [Indexed: 02/02/2023]
Abstract
Accumulating data suggest a causative link between immune stimulation, disturbed metabolism of tryptophan, and pathogenesis of bipolar disorder and schizophrenia. The goal of this study was to examine the production of kynurenic acid (KYNA), 3-hydroxykynurenine (3-HK) and the expression of kynurenine pathway enzymes involved in their synthesis and metabolism in cultured skin fibroblasts obtained from patients with bipolar disorder, schizophrenia or from healthy control individuals. The assessment was performed under basal conditions or following treatment with interferon (IFN)-γ, tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, or their combinations, in cells exposed to exogenous kynurenine. In both groups of patients, the baseline production of KYNA and 3-HK was increased, as compared to control subjects. Case-treatment analyses revealed significant interactions between bipolar case status and IL-1β, IL-6, IFN-γ + TNF-α, or IFN-γ + IL-1β, as well as between schizophrenia case status and IL-1β, IFN-γ + TNF-α, or IFN-γ + IL-1β, in terms of higher 3-HK. Noteworthy, no case-treatment interactions in terms of KYNA production were found. Observed changes did not appear to correlate with the expression of genes encoding kynurenine aminotransferases (KATs), kynureninase (KYNU) or kynurenine-3-monooxygenase (KMO). The single nucleotide polymorphisms (SNPs), rs1053230 and rs2275163, in KMO influenced KYNA levels yet did not explain the case-treatment discrepancies. In conclusion, our present findings indicate the utility of skin-derived fibroblasts for kynurenines research and support the concept of kynurenine pathway alterations in bipolar disorder and schizophrenia. The increase in ratio between neurotoxic 3-HK and neuroinhibitory/neuroprotective KYNA following exposure to cytokines may account for altered neurogenesis and structural abnormalities characteristic for both diseases.
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Iaccarino HF, Suckow RF, Xie S, Bucci DJ. The effect of transient increases in kynurenic acid and quinolinic acid levels early in life on behavior in adulthood: Implications for schizophrenia. Schizophr Res 2013; 150:392-7. [PMID: 24091034 PMCID: PMC3844520 DOI: 10.1016/j.schres.2013.09.004] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/17/2013] [Revised: 09/06/2013] [Accepted: 09/11/2013] [Indexed: 10/26/2022]
Abstract
Kynurenic acid is a tryptophan metabolite that is synthesized and released in the brain by astrocytes and acts as an antagonist of nicotinic acetylcholine receptors and N-methyl-d-aspartate glutamate receptors, both of which are critically involved in cognition as well as neural plasticity and brain development. The concentration of kynurenic acid is increased in the brains of persons with schizophrenia and this increase has been implicated in the cognitive and social impairments associated with the disease. In addition, growing evidence suggests that the increase in kynurenic acid may begin early in life. For example, exposure to influenza A virus during development results in a transient increase in kynurenic acid concentration that could disrupt normal brain development and lead to cognitive deficits later in life. Changes in kynurenic acid may thus provide a link between developmental exposure to viruses and the increased risk of subsequently developing schizophrenia. To test this, we mimicked the effects of influenza A exposure by treating rats with kynurenine, the precursor of kynurenic acid, on postnatal days 7-10. We observed a transient increase in both kynurenic acid and quinolinic acid during treatment. When rats were subsequently behaviorally tested as adults, those previously treated with kynurenine exhibited decreased social behavior and locomotor activity. In contrast, attentional function and fear conditioning were not affected. Together with other recent findings, these data have several implications for understanding how viral-induced changes in tryptophan metabolism during development may contribute to schizophrenia-related symptoms later in life.
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Affiliation(s)
- Hannah F. Iaccarino
- Department of Psychological and Brain Sciences, Dartmouth College, Hanover, NH 03755
| | | | - Shan Xie
- Nathan Kline Institute, Orangeburg, New York 10962
| | - David J. Bucci
- Department of Psychological and Brain Sciences, Dartmouth College, Hanover, NH 03755
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Möller M, Du Preez JL, Viljoen FP, Berk M, Emsley R, Harvey BH. Social isolation rearing induces mitochondrial, immunological, neurochemical and behavioural deficits in rats, and is reversed by clozapine or N-acetyl cysteine. Brain Behav Immun 2013; 30:156-67. [PMID: 23270677 DOI: 10.1016/j.bbi.2012.12.011] [Citation(s) in RCA: 132] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/27/2012] [Revised: 12/04/2012] [Accepted: 12/14/2012] [Indexed: 02/01/2023] Open
Abstract
Apart from altered dopamine (DA) function, schizophrenia displays mitochondrial and immune-inflammatory abnormalities, evidenced by oxidative stress, altered kynurenine metabolism and cytokine release. N-acetyl cysteine (NAC), an antioxidant and glutamate modulator, is effective in the adjunctive treatment of schizophrenia. Social isolation rearing (SIR) in rats is a valid neurodevelopmental animal model of schizophrenia. This study evaluated whether SIR-induced behavioural deficits may be explained by altered plasma pro- and anti-inflammatory cytokines, kynurenine metabolism, and cortico-striatal DA and mitochondrial function (via adenosine triphosphate (ATP) release), and if clozapine or NAC (alone and in combination) reverses these changes. SIR induced pronounced deficits in social interactive behaviours, object recognition memory, and prepulse inhibition (PPI), while simultaneously increasing striatal but reducing frontal cortical accumulation of ATP as well as DA. SIR increased pro- vs. anti-inflammatory cytokine balance and altered kynurenine metabolism with a decrease in neuroprotective ratio. Clozapine (5mg/kg/day×14days) as well as clozapine+NAC (5mg/kg/day and 150mg/kg/day×14days) reversed these changes, with NAC (150mg/kg/day) alone significantly but partially effective in some parameters. Clozapine+NAC was more effective than clozapine alone in reversing SIR-induced PPI, mitochondrial, immune and DA changes. In conclusion, SIR induces mitochondrial and immune-inflammatory changes that underlie cortico-striatal DA perturbations and subsequent behavioural deficits, and responds to treatment with clozapine or NAC, with an additive effect following combination treatment. The data provides insight into the mechanisms that might underlie the utility of NAC as an adjunctive treatment in schizophrenia.
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Affiliation(s)
- Marisa Möller
- Division of Pharmacology, School of Pharmacy, North West University, Potchefstroom, South Africa
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Steiner J, Bogerts B, Sarnyai Z, Walter M, Gos T, Bernstein HG, Myint AM. Bridging the gap between the immune and glutamate hypotheses of schizophrenia and major depression: Potential role of glial NMDA receptor modulators and impaired blood-brain barrier integrity. World J Biol Psychiatry 2012; 13:482-92. [PMID: 21707463 DOI: 10.3109/15622975.2011.583941] [Citation(s) in RCA: 105] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
OBJECTIVES Previous studies have suggested that the pathogenesis of schizophrenia and major depression involves an altered peripheral immune system. It is not clear, however, whether such changes are associated with corresponding neuroinflammatory responses and disturbances of neurotransmission. METHODS This paper reviews the current state of knowledge about the involvement of immune alterations in schizophrenia and major depression and a possible link to disturbances of glutamatergic transmission. RESULTS Inflammatory endogenous modulators of the NMDA receptor, the kynurenine pathway metabolites, are potential candidates for such a link. Studies of the blood and cerebrospinal fluid have suggested a schizophrenia-related upregulation of the NMDA receptor antagonist kynurenic acid in astrocytes, analogous to the ketamine psychosis model. Conversely, it has been proposed that there is depression-related microglial synthesis of the NMDA receptor agonist quinolinic acid, which is consistent with the observation that ketamine has therapeutic effects in major depression. Few publications have studied NMDA receptor modulating kynurenines in the brain, however. CONCLUSIONS Future research on the cerebral cell-type specific distribution of kynurenine metabolites and their brain-regional concentration imbalances will be required to connect peripheral immune changes, the hypotheses of blood-brain barrier dysfunction and glial pathology with concepts of altered neurotransmission in schizophrenia and major depression.
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Affiliation(s)
- Johann Steiner
- Department of Psychiatry, University of Magdeburg, Magdeburg, Germany.
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42
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Neuroinflammation and depression: the role of indoleamine 2,3-dioxygenase (IDO) as a molecular pathway. Psychosom Med 2012; 74:668-72. [PMID: 22923699 DOI: 10.1097/psy.0b013e318268de9f] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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A rodent model of premenstrual dysphoria: progesterone withdrawal induces depression-like behavior that is differentially sensitive to classes of antidepressants. Behav Brain Res 2012; 234:238-47. [PMID: 22789402 DOI: 10.1016/j.bbr.2012.06.034] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2012] [Revised: 06/25/2012] [Accepted: 06/30/2012] [Indexed: 11/20/2022]
Abstract
Premenstrual dysphoric disorder (PMDD) is characterized by a range of physical and affective symptoms including anxiety, irritability, anhedonia, social withdrawal and depression. We demonstrate robust and reproducible depression-like behavior during progesterone withdrawal (PWD) protocols with different methodological variables. Comparable immobility in the forced swim test was evident with different routes of administration (i.e. injections vs. implants), with and without exogenous estrogens in addition to progesterone, and in both single and multiple withdrawal paradigms. Furthermore, withdrawal from physiological doses of progesterone resulted in modest social withdrawal in the social preference test and anhedonia in the saccharin preference test without altering general activity levels or total liquid consumption. However, progesterone withdrawal did not alter serotonin levels in the cortex or hippocampus. Furthermore tryptophan depletion did not augment immobility during PWD. Neither fluoxetine nor duloxetine reduced depression-like behavior during PWD in the forced swim test. In contrast, the tricyclic antidepressant, amitriptyline, was effective in reducing the immobility in forced swim test. These data demonstrate that progesterone withdrawal is a reproducible model of PMDD in several critical behavioral domains. Furthermore, these data do not support alterations in serotonin levels in the etiology of hormonally induced depression.
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Akagbosu CO, Evans GC, Gulick D, Suckow RF, Bucci DJ. Exposure to kynurenic acid during adolescence produces memory deficits in adulthood. Schizophr Bull 2012; 38:769-78. [PMID: 21172906 PMCID: PMC3577048 DOI: 10.1093/schbul/sbq151] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The glia-derived molecule kynurenic acid (KYNA) is an antagonist of α7 nicotinic acetylcholine receptors and the glycine(B) binding site on n-methyl-d-aspartateglutamate receptors, both of which have critical roles in neural plasticity as well as learning and memory. KYNA levels are increased in the brains and cerebral spinal fluid of persons with schizophrenia, leading to the notion that changes in KYNA concentration might contribute to cognitive dysfunction associated with this disorder. Indeed, recent studies indicate that increasing endogenous KYNA concentration by administering l-kynurenine (L-KYN, the precursor of KYNA) impairs spatial as well as contextual learning and memory in adult rats. In the present study, rats were treated with L-KYN (100 mg/kg) throughout adolescence to increase endogenous KYNA concentration during this critical time in brain development. Rats were then tested drug-free as adults to test the hypothesis that exposure to elevated levels of KYNA during development may contribute to cognitive dysfunction later in life. Consistent with prior studies in which adult rats were treated acutely with L-KYN, juvenile rats exposed to increased KYNA concentration during adolescence exhibited deficits in contextual fear memory, but cue-specific fear memory was not impaired. In addition, rats treated with L-KYN as adolescents were impaired on a novel object recognition memory task when tested as adults. The memory deficits could not be explained by drug-induced changes in locomotor activity or shock sensitivity. Together, these findings add to the growing literature supporting the notion that exposure to increased concentration of KYNA may contribute to cognitive deficits typically observed in schizophrenia.
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Affiliation(s)
- Cynthia O. Akagbosu
- Department of Psychological and Brain Sciences, Dartmouth College, Hanover, NH
| | - Gretchen C. Evans
- Department of Psychological and Brain Sciences, Dartmouth College, Hanover, NH
| | - Danielle Gulick
- Department of Psychiatry, Dartmouth Medical School, Lebanon, NH
| | | | - David J. Bucci
- Department of Psychological and Brain Sciences, Dartmouth College, Hanover, NH,To whom correspondence should be addressed; tel: 603-646-3439, fax: 603-646-1419, e-mail:
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Möller M, Du Preez JL, Emsley R, Harvey BH. Social isolation rearing in rats alters plasma tryptophan metabolism and is reversed by sub-chronic clozapine treatment. Neuropharmacology 2012; 62:2499-506. [DOI: 10.1016/j.neuropharm.2012.02.021] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2011] [Revised: 02/08/2012] [Accepted: 02/25/2012] [Indexed: 10/28/2022]
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46
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Development and validation of a single analytical method for the determination of tryptophan, and its kynurenine metabolites in rat plasma. J Chromatogr B Analyt Technol Biomed Life Sci 2012; 898:121-9. [DOI: 10.1016/j.jchromb.2012.04.030] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2012] [Revised: 04/24/2012] [Accepted: 04/25/2012] [Indexed: 02/03/2023]
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47
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Linderholm KR, Skogh E, Olsson SK, Dahl ML, Holtze M, Engberg G, Samuelsson M, Erhardt S. Increased levels of kynurenine and kynurenic acid in the CSF of patients with schizophrenia. Schizophr Bull 2012; 38:426-32. [PMID: 20729465 PMCID: PMC3329991 DOI: 10.1093/schbul/sbq086] [Citation(s) in RCA: 222] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
BACKGROUND The kynurenic acid (KYNA) hypothesis for schizophrenia is partly based on studies showing increased brain levels of KYNA in patients. KYNA is an endogenous metabolite of tryptophan (TRP) produced in astrocytes and antagonizes N-methyl-D-aspartate and α7* nicotinic receptors. METHODS The formation of KYNA is determined by the availability of substrate, and hence, we analyzed KYNA and its precursors, kynurenine (KYN) and TRP, in the cerebrospinal fluid (CSF) of patients with schizophrenia. CSF from male patients with schizophrenia on olanzapine treatment (n = 16) was compared with healthy male volunteers (n = 29). RESULTS KYN and KYNA concentrations were higher in patients with schizophrenia (60.7 ± 4.37 nM and 2.03 ± 0.23 nM, respectively) compared with healthy volunteers (28.6 ± 1.44 nM and 1.36 ± 0.08 nM, respectively), whereas TRP did not differ between the groups. In all subjects, KYN positively correlated to KYNA. CONCLUSION Our results demonstrate increased levels of CSF KYN and KYNA in patients with schizophrenia and further support the hypothesis that KYNA is involved in the pathophysiology of schizophrenia.
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Affiliation(s)
- Klas R. Linderholm
- Department of Physiology and Pharmacology, Nanna Svartz väg 2, Karolinska Institutet, SE-171 77 Stockholm, Sweden
| | - Elisabeth Skogh
- Department of Clinical and Experimental Medicine, Section of Psychiatry, Faculty of Health Sciences, Linköping University, Linköping, Sweden
| | - Sara K. Olsson
- Department of Physiology and Pharmacology, Nanna Svartz väg 2, Karolinska Institutet, SE-171 77 Stockholm, Sweden
| | - Marja-Liisa Dahl
- Department of Medical Sciences, Clinical Pharmacology, Uppsala University, Uppsala, Sweden
- Department of Clinical Pharmacology, Karolinska University Hospital, Stockholm, Sweden
| | - Maria Holtze
- Department of Physiology and Pharmacology, Nanna Svartz väg 2, Karolinska Institutet, SE-171 77 Stockholm, Sweden
| | - Göran Engberg
- Department of Physiology and Pharmacology, Nanna Svartz väg 2, Karolinska Institutet, SE-171 77 Stockholm, Sweden
| | - Martin Samuelsson
- Department of Clinical and Experimental Medicine, Section of Psychiatry, Faculty of Health Sciences, Linköping University, Linköping, Sweden
| | - Sophie Erhardt
- Department of Physiology and Pharmacology, Nanna Svartz väg 2, Karolinska Institutet, SE-171 77 Stockholm, Sweden
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Actions of Xanthurenic acid, a putative endogenous Group II metabotropic glutamate receptor agonist, on sensory transmission in the thalamus. Neuropharmacology 2012; 66:133-42. [PMID: 22491023 DOI: 10.1016/j.neuropharm.2012.03.009] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2012] [Revised: 02/29/2012] [Accepted: 03/13/2012] [Indexed: 11/21/2022]
Abstract
Xanthurenic acid (XA), a molecule arising from tryptophan metabolism by transamination of 3-hydroxykynurenine, has recently been identified as an endogenous Group II (mGlu2 and mGlu3) metabotropic glutamate (mGlu) receptor ligand in vitro. Impairments in Group II mGlu receptor expression and function have been implicated in the pathophysiology of schizophrenia, as have multiple steps in the kynurenine metabolism pathway. Therefore, we examined XA in vivo to further investigate its potential as a Group II mGlu receptor ligand using a preparation that has been previously demonstrated to efficiently reveal the action of other Group II mGlu receptor ligands in vivo. Extracellular single-neurone recordings were made in the rat ventrobasal thalamus (VB) in conjunction with iontophoresis of agonists, an antagonist and a positive allosteric modulator and/or intravenous (i.v.) injection of XA. We found the XA effect on sensory inhibition, when applied iontophoretically and i.v., was similar to that of other Group II mGlu receptor agonists in reducing inhibition evoked in the VB from the thalamic reticular nucleus upon physiological sensory stimulation. Furthermore, we postulate that XA may be the first potential endogenous allosteric agonist (termed 'endocoid') for the mGlu receptors. As the Group II receptors and kynurenine metabolism pathway have both been heavily implicated in the pathophysiology of schizophrenia, XA could play a pivotal role in antipsychotic research as this potential endocoid represents both a convergence within these two biological parameters and a novel class of Group II mGlu receptor ligand. This article is part of a Special Issue entitled 'Metabotropic Glutamate Receptors'.
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49
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Administration of kynurenine during adolescence, but not during adulthood, impairs social behavior in rats. Schizophr Res 2011; 133:156-8. [PMID: 21907545 PMCID: PMC3225639 DOI: 10.1016/j.schres.2011.08.014] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2011] [Revised: 08/18/2011] [Accepted: 08/22/2011] [Indexed: 11/20/2022]
Abstract
Kynurenic acid (KYNA) is a tryptophan metabolite that is present at high concentrations in the brains of persons with schizophrenia. This study tested the hypothesis that treatment with L-kynurenine (L-KYN), which increases KYNA concentration, would produce deficits in social behavior similar to those associated with schizophrenia. Rats treated with L-KYN throughout adolescence exhibited decreased social interaction when tested drug-free as adults. In contrast, neither acute nor chronic treatment during adulthood affected social behavior. These findings demonstrate that increases in KYNA concentration produce deficits in social behavior and that the adolescent brain is particularly susceptible to the effects of high KYNA concentration.
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50
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Sathyasaikumar KV, Stachowski EK, Wonodi I, Roberts RC, Rassoulpour A, McMahon RP, Schwarcz R. Impaired kynurenine pathway metabolism in the prefrontal cortex of individuals with schizophrenia. Schizophr Bull 2011; 37:1147-56. [PMID: 21036897 PMCID: PMC3196941 DOI: 10.1093/schbul/sbq112] [Citation(s) in RCA: 183] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The levels of kynurenic acid (KYNA), an astrocyte-derived metabolite of the branched kynurenine pathway (KP) of tryptophan degradation and antagonist of α7 nicotinic acetylcholine and N-methyl-D-aspartate receptors, are elevated in the prefrontal cortex (PFC) of individuals with schizophrenia (SZ). Because endogenous KYNA modulates extracellular glutamate and acetylcholine levels in the PFC, these increases may be pathophysiologically significant. Using brain tissue from SZ patients and matched controls, we now measured the activity of several KP enzymes (kynurenine 3-monooxygenase [KMO], kynureninase, 3-hydroxyanthranilic acid dioxygenase [3-HAO], quinolinic acid phosphoribosyltransferase [QPRT], and kynurenine aminotransferase II [KAT II]) in the PFC, ie, Brodmann areas (BA) 9 and 10. Compared with controls, the activities of KMO (in BA 9 and 10) and 3-HAO (in BA 9) were significantly reduced in SZ, though there were no significant differences between patients and controls in kynureninase, QPRT, and KAT II. In the same samples, we also confirmed the increase in the tissue levels of KYNA in SZ. As examined in rats treated chronically with the antipsychotic drug risperidone, the observed biochemical changes were not secondary to medication. A persistent reduction in KMO activity may have a particular bearing on pathology because it may signify a shift of KP metabolism toward enhanced KYNA synthesis. The present results further support the hypothesis that the normalization of cortical KP metabolism may constitute an effective new treatment strategy in SZ.
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Affiliation(s)
- Korrapati V. Sathyasaikumar
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore
| | - Erin K. Stachowski
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore
| | - Ikwunga Wonodi
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore
| | - Rosalinda C. Roberts
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore,Present address: Department of Psychiatry and Behavioral Neurobiology, University of Alabama, Birmingham, AL 35294
| | - Arash Rassoulpour
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore
| | - Robert P. McMahon
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore
| | - Robert Schwarcz
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore,To whom correspondence should be addressed; Maryland Psychiatric Research Center, PO Box 21247, Baltimore, MD 21228; tel: 410-402-7635, fax: 410-747-2434, e-mail:
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