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Campanale A, Inserra A, Comai S. Therapeutic modulation of the kynurenine pathway in severe mental illness and comorbidities: A potential role for serotonergic psychedelics. Prog Neuropsychopharmacol Biol Psychiatry 2024:111058. [PMID: 38885875 DOI: 10.1016/j.pnpbp.2024.111058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Revised: 05/15/2024] [Accepted: 06/14/2024] [Indexed: 06/20/2024]
Abstract
Mounting evidence points towards a crucial role of the kynurenine pathway (KP) in the altered gut-brain axis (GBA) balance in severe mental illness (SMI, namely depression, bipolar disorder, and schizophrenia) and cardiometabolic comorbidities. Preliminary evidence shows that serotonergic psychedelics and their analogues may hold therapeutic potential in addressing the altered KP in the dysregulated GBA in SMI and comorbidities. In fact, aside from their effects on mood, psychedelics elicit therapeutic improvement in preclinical models of obesity, metabolic syndrome, and vascular inflammation, which are highly comorbid with SMI. Here, we review the literature on the therapeutic modulation of the KP in the dysregulated GBA in SMI and comorbidities, and the potential application of psychedelics to address the altered KP in the brain and systemic dysfunction underlying SMI and comorbidities. Endogenous and exogenous psychedelics might therapeutically modulate the KP in the altered GBA in SMI and comorbidities directly, via altering the metabolic pathway by influencing the rate-limiting enzymes of the KP and affecting the levels of available tryptophan, or indirectly, by affecting the gut microbiome, gut metabolome, metabolism, and the immune system. Despite promising preliminary evidence, the mechanisms and outcomes of the KP modulation with psychedelics in SMI and systemic comorbidities remain largely unknown and require further investigation. Several concerns are discussed surrounding the potential side effects of this approach in specific cohorts of individuals with SMI and systemic comorbidities.
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Affiliation(s)
| | - Antonio Inserra
- Department of Psychiatry, McGill University, Montreal, QC, Canada
| | - Stefano Comai
- Department of Psychiatry, McGill University, Montreal, QC, Canada; Department of Pharmaceutical and Pharmacological Sciences, University of Padova, PD, Italy.; IRCCS San Raffaele Scientific Institute, Milan, Italy; Department of Biomedical Sciences, University of Padua, Padua, Italy.
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2
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Frescura F, Stark T, Tiziani E, Di Martino S, Ruda-Kucerova J, Drago F, Ferraro L, Micale V, Beggiato S. Prenatal MAM exposure raises kynurenic acid levels in the prefrontal cortex of adult rats. Pharmacol Rep 2024:10.1007/s43440-024-00604-6. [PMID: 38789891 DOI: 10.1007/s43440-024-00604-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2024] [Revised: 05/15/2024] [Accepted: 05/15/2024] [Indexed: 05/26/2024]
Abstract
BACKGROUND Elevated brain levels of kynurenic acid (KYNA), a metabolite in the kynurenine pathway, are associated with cognitive dysfunctions, which are nowadays often considered as fundamental characteristics of several psychopathologies; however, the role of KYNA in mental illnesses, such as schizophrenia, is not fully elucidated. This study aimed to assess KYNA levels in the prefrontal cortex (PFC) of rats prenatally treated with methylazoxymethanol (MAM) acetate, i.e., a well-validated neurodevelopmental animal model of schizophrenia. The effects of an early pharmacological modulation of the endogenous cannabinoid system were also evaluated. METHODS Pregnant Sprague-Dawley rats were treated with MAM (22 mg/kg, ip) or its vehicle at gestational day 17. Male offspring were treated with the cannabinoid CB1 receptor antagonist/inverse agonist AM251 (0.5 mg/kg/day, ip) or with the typical antipsychotic haloperidol (0.6 mg/kg/day, ip) from postnatal day (PND) 19 to PND39. The locomotor activity and cognitive performance were assessed in the novel object recognition test and the open field test in adulthood. KYNA levels in the PFC of prenatally MAM-treated rats were also assessed. RESULTS A significant cognitive impairment was observed in prenatally MAM-treated rats (p < 0.01), which was associated with enhanced PFC KYNA levels (p < 0.05). The peripubertal AM251, but not haloperidol, treatment ameliorated the cognitive deficit (p < 0.05), by normalizing the PFC KYNA content in MAM rats. CONCLUSIONS The present findings suggest that the cognitive deficit observed in MAM rats may be related to enhanced PFC KYNA levels which could be, in turn, mediated by the activation of cannabinoid CB1 receptor. These results further support the modulation of brain KYNA levels as a potential therapeutic strategy to ameliorate the cognitive dysfunctions in schizophrenia.
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Affiliation(s)
- Francesca Frescura
- Department of Life Sciences and Biotechnology, University of Ferrara, Via L. Borsari 46, 44121, Ferrara, Italy
| | - Tibor Stark
- Department Emotion Research, Max Planck Institute of Psychiatry, 80807, Munich, Germany
| | - Edoardo Tiziani
- Department of Life Sciences and Biotechnology, University of Ferrara, Via L. Borsari 46, 44121, Ferrara, Italy
| | - Serena Di Martino
- Department of Biomedical and Biotechnological Sciences, University of Catania, 95123, Catania, Italy
| | - Jana Ruda-Kucerova
- Department of Pharmacology, Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Filippo Drago
- Department of Biomedical and Biotechnological Sciences, University of Catania, 95123, Catania, Italy
| | - Luca Ferraro
- Department of Life Sciences and Biotechnology, University of Ferrara, Via L. Borsari 46, 44121, Ferrara, Italy.
- LTTA Centre, University of Ferrara, Ferrara, Italy.
- Psychiatric Department, School of Medicine, University of Maryland, Baltimore, MD, USA.
| | - Vincenzo Micale
- Department of Biomedical and Biotechnological Sciences, University of Catania, 95123, Catania, Italy
| | - Sarah Beggiato
- Department of Life Sciences and Biotechnology, University of Ferrara, Via L. Borsari 46, 44121, Ferrara, Italy
- Psychiatric Department, School of Medicine, University of Maryland, Baltimore, MD, USA
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Cadenhead KS, Mirzakhanian H, Achim C, Reyes-Madrigal F, de la Fuente-Sandoval C. Peripheral and central biomarkers associated with inflammation in antipsychotic naïve first episode psychosis: Pilot studies. Schizophr Res 2024; 264:39-48. [PMID: 38091871 DOI: 10.1016/j.schres.2023.11.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Revised: 09/26/2023] [Accepted: 11/28/2023] [Indexed: 03/01/2024]
Abstract
BACKGROUND Elevated serum pro-inflammatory molecules have been reported in early psychosis. What is not known is whether peripheral inflammatory biomarkers are associated with CNS biomarkers. In the brain, release of pro-inflammatory molecules by microglial hyperactivity may lead to neuronal apoptosis seen in neurodegenerative disorders and account for loss of brain tissue observed in psychotic disorders. Neurochemical changes, including elevated glutamate levels, are also associated with neuroinflammation, present in early psychosis and change with antipsychotic treatment. METHODS Antipsychotic naïve patients with first episode psychosis (FEP) were studied as part of a collaborative project of neuroinflammation. In Study 1 we explored associations between plasma inflammatory molecules and neurometabolites in the dorsal caudate using magnetic resonance spectroscopy (1H-MRS) in N = 13 FEP participants. Study 2 examined the relationship between inflammatory molecules in the Plasma and CSF in N = 20 FEP participants. RESULTS In Study 1, the proinflammatory chemokine MDC/CCL22 and IL10 were significantly positively correlated with Glutamate and Glx (glutamate + glutamine) levels in the dorsal caudate. In Study 2, plasma inflammatory molecules (MIP1β/CCL4, MCP1/CCL2, Eotaxin-1/CCL11 and TNFα) were significantly correlated with CSF MIP1β/CCL4, IL10, MCP1/CCL2 and Fractalkine/CX3CL1 and symptoms ratings. DISCUSSION Plasma inflammatory biomarkers are elevated in early psychosis, associated with neurochemical markers as well as CSF inflammatory molecules found in neurodegenerative disorders. Future studies are needed that combine both peripheral and central biomarkers in both FEP and HC to better understand a potential neuroinflammatory subtype of psychosis likely to respond to targeted interventions.
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Affiliation(s)
- Kristin S Cadenhead
- University of California San Diego (UCSD), 9500 Gilman Dr, La Jolla, CA 92093-0810, United States of America.
| | - Heline Mirzakhanian
- University of California San Diego (UCSD), 9500 Gilman Dr, La Jolla, CA 92093-0810, United States of America.
| | - Cristian Achim
- University of California San Diego (UCSD), 9500 Gilman Dr, La Jolla, CA 92093-0810, United States of America.
| | - Francisco Reyes-Madrigal
- Instituto Nacional de Neurología y Neurocirugía (INNN), Insurgentes Sur 3877, Tlalpan, 14269 Mexico City, Mexico.
| | - Camilo de la Fuente-Sandoval
- Instituto Nacional de Neurología y Neurocirugía (INNN), Insurgentes Sur 3877, Tlalpan, 14269 Mexico City, Mexico.
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Sheibani M, Shayan M, Khalilzadeh M, Soltani ZE, Jafari-Sabet M, Ghasemi M, Dehpour AR. Kynurenine pathway and its role in neurologic, psychiatric, and inflammatory bowel diseases. Mol Biol Rep 2023; 50:10409-10425. [PMID: 37848760 DOI: 10.1007/s11033-023-08859-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2023] [Accepted: 09/27/2023] [Indexed: 10/19/2023]
Abstract
Tryptophan metabolism along the kynurenine pathway is of central importance for the immune function. It prevents hyperinflammation and induces long-term immune tolerance. Accumulating evidence also demonstrates cytoprotective and immunomodulatory properties of kynurenine pathway in conditions affecting either central or peripheral nervous system as well as other conditions such as inflammatory bowel disease (IBD). Although multilevel association exists between the inflammatory bowel disease (IBD) and various neurologic (e.g., neurodegenerative) disorders, it is believed that the kynurenine pathway plays a pivotal role in the development of both IBD and neurodegenerative disorders. In this setting, there is strong evidence linking the gut-brain axis with intestinal dysfunctions including IBD which is consistent with the fact that the risk of neurodegenerative diseases is higher in IBD patients. This review aims to highlight the role of kynurenine metabolic pathway in various neurologic and psychiatric diseases as well as relationship between IBD and neurodegenerative disorders in the light of the kynurenine metabolic pathway.
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Affiliation(s)
- Mohammad Sheibani
- Department of Pharmacology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
- Razi Drug Research Centre, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Maryam Shayan
- Experimental Medicine Research Centre, Tehran University of Medical Sciences, Tehran, MS, Iran
- Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Mina Khalilzadeh
- Experimental Medicine Research Centre, Tehran University of Medical Sciences, Tehran, MS, Iran
- Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Zahra Ebrahim Soltani
- Experimental Medicine Research Centre, Tehran University of Medical Sciences, Tehran, MS, Iran
- Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Majid Jafari-Sabet
- Department of Pharmacology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
- Razi Drug Research Centre, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Mehdi Ghasemi
- Department of Neurology, Lahey Hospital and Medical Center, 41 Mall Road, Burlington, MA, 01803, USA.
| | - Ahmad Reza Dehpour
- Experimental Medicine Research Centre, Tehran University of Medical Sciences, Tehran, MS, Iran.
- Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
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Hare SM, Adhikari BM, Mo C, Chen S, Wijtenburg SA, Seneviratne C, Kane-Gerard S, Sathyasaikumar KV, Notarangelo FM, Schwarcz R, Kelly DL, Rowland LM, Buchanan RW. Tryptophan challenge in individuals with schizophrenia and healthy controls: acute effects on circulating kynurenine and kynurenic acid, cognition and cerebral blood flow. Neuropsychopharmacology 2023; 48:1594-1601. [PMID: 37118058 PMCID: PMC10516920 DOI: 10.1038/s41386-023-01587-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 03/31/2023] [Accepted: 04/06/2023] [Indexed: 04/30/2023]
Abstract
Cognitive impairments predict poor functional outcomes in people with schizophrenia. These impairments may be causally related to increased levels of kynurenic acid (KYNA), a major metabolic product of tryptophan (TRYP). In the brain, KYNA acts as an antagonist of the of α7-nicotinic acetylcholine and NMDA receptors, both of which are involved in cognitive processes. To examine whether KYNA plays a role in the pathophysiology of schizophrenia, we compared the acute effects of a single oral dose of TRYP (6 g) in 32 healthy controls (HC) and 37 people with either schizophrenia (Sz), schizoaffective or schizophreniform disorder, in a placebo-controlled, randomized crossover study. We examined plasma levels of KYNA and its precursor kynurenine; selected cognitive measures from the MATRICS Consensus Cognitive Battery; and resting cerebral blood flow (CBF) using arterial spin labeling imaging. In both cohorts, the TRYP challenge produced significant, time-dependent elevations in plasma kynurenine and KYNA. The resting CBF signal (averaged across all gray matter) was affected differentially, such that TRYP was associated with higher CBF in HC, but not in participants with a Sz-related disorder. While TRYP did not significantly impair cognitive test performance, there was a trend for TRYP to worsen visuospatial memory task performance in HC. Our results demonstrate that oral TRYP challenge substantially increases plasma levels of kynurenine and KYNA in both groups, but exerts differential group effects on CBF. Future studies are required to investigate the mechanisms underlying these CBF findings, and to evaluate the impact of KYNA fluctuations on brain function and behavior. (Clinicaltrials.gov: NCT02067975).
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Affiliation(s)
- Stephanie M Hare
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD, 21201, USA.
| | - Bhim M Adhikari
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
| | - Chen Mo
- Harvard Medical School, Boston, MA, 02115, USA
| | - Shuo Chen
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
| | - S Andrea Wijtenburg
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
| | - Chamindi Seneviratne
- Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
| | - Samuel Kane-Gerard
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
| | - Korrapati V Sathyasaikumar
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
| | - Francesca M Notarangelo
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
| | - Robert Schwarcz
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
| | - Deanna L Kelly
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
| | - Laura M Rowland
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
| | - Robert W Buchanan
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
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6
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de Bartolomeis A, Ciccarelli M, De Simone G, Mazza B, Barone A, Vellucci L. Canonical and Non-Canonical Antipsychotics' Dopamine-Related Mechanisms of Present and Next Generation Molecules: A Systematic Review on Translational Highlights for Treatment Response and Treatment-Resistant Schizophrenia. Int J Mol Sci 2023; 24:ijms24065945. [PMID: 36983018 PMCID: PMC10051989 DOI: 10.3390/ijms24065945] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 03/15/2023] [Accepted: 03/17/2023] [Indexed: 03/30/2023] Open
Abstract
Schizophrenia is a severe psychiatric illness affecting almost 25 million people worldwide and is conceptualized as a disorder of synaptic plasticity and brain connectivity. Antipsychotics are the primary pharmacological treatment after more than sixty years after their introduction in therapy. Two findings hold true for all presently available antipsychotics. First, all antipsychotics occupy the dopamine D2 receptor (D2R) as an antagonist or partial agonist, even if with different affinity; second, D2R occupancy is the necessary and probably the sufficient mechanism for antipsychotic effect despite the complexity of antipsychotics' receptor profile. D2R occupancy is followed by coincident or divergent intracellular mechanisms, implying the contribution of cAMP regulation, β-arrestin recruitment, and phospholipase A activation, to quote some of the mechanisms considered canonical. However, in recent years, novel mechanisms related to dopamine function beyond or together with D2R occupancy have emerged. Among these potentially non-canonical mechanisms, the role of Na2+ channels at the dopamine at the presynaptic site, dopamine transporter (DAT) involvement as the main regulator of dopamine concentration at synaptic clefts, and the putative role of antipsychotics as chaperones for intracellular D2R sequestration, should be included. These mechanisms expand the fundamental role of dopamine in schizophrenia therapy and may have relevance to considering putatively new strategies for treatment-resistant schizophrenia (TRS), an extremely severe condition epidemiologically relevant and affecting almost 30% of schizophrenia patients. Here, we performed a critical evaluation of the role of antipsychotics in synaptic plasticity, focusing on their canonical and non-canonical mechanisms of action relevant to the treatment of schizophrenia and their subsequent implication for the pathophysiology and potential therapy of TRS.
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Affiliation(s)
- Andrea de Bartolomeis
- Section of Psychiatry, Laboratory of Translational and Molecular Psychiatry and Unit of Treatment-Resistant Psychosis, Department of Neuroscience, Reproductive Sciences and Dentistry, University Medical School of Naples "Federico II", 80131 Naples, Italy
| | - Mariateresa Ciccarelli
- Section of Psychiatry, Laboratory of Translational and Molecular Psychiatry and Unit of Treatment-Resistant Psychosis, Department of Neuroscience, Reproductive Sciences and Dentistry, University Medical School of Naples "Federico II", 80131 Naples, Italy
| | - Giuseppe De Simone
- Section of Psychiatry, Laboratory of Translational and Molecular Psychiatry and Unit of Treatment-Resistant Psychosis, Department of Neuroscience, Reproductive Sciences and Dentistry, University Medical School of Naples "Federico II", 80131 Naples, Italy
| | - Benedetta Mazza
- Section of Psychiatry, Laboratory of Translational and Molecular Psychiatry and Unit of Treatment-Resistant Psychosis, Department of Neuroscience, Reproductive Sciences and Dentistry, University Medical School of Naples "Federico II", 80131 Naples, Italy
| | - Annarita Barone
- Section of Psychiatry, Laboratory of Translational and Molecular Psychiatry and Unit of Treatment-Resistant Psychosis, Department of Neuroscience, Reproductive Sciences and Dentistry, University Medical School of Naples "Federico II", 80131 Naples, Italy
| | - Licia Vellucci
- Section of Psychiatry, Laboratory of Translational and Molecular Psychiatry and Unit of Treatment-Resistant Psychosis, Department of Neuroscience, Reproductive Sciences and Dentistry, University Medical School of Naples "Federico II", 80131 Naples, Italy
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Deficiency of kynurenine 3-monooxygenase exacerbates impairment of prepulse inhibition induced by phencyclidine. Biochem Biophys Res Commun 2022; 629:142-151. [PMID: 36116377 DOI: 10.1016/j.bbrc.2022.09.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Accepted: 09/01/2022] [Indexed: 11/23/2022]
Abstract
Phencyclidine (PCP) causes mental symptoms that closely resemble schizophrenia through the inhibition of the glutamatergic system. The kynurenine (KYN) pathway (KP) generates metabolites that modulate glutamatergic systems such as kynurenic acid (KA), quinolinic acid (QA), and xanthurenic acid (XA). Kynurenine 3-monooxygenase (KMO) metabolizes KYN to 3-hydroxykynurenine (3-HK), an upstream metabolite of QA and XA. Clinical studies have reported lower KMO mRNA and higher KA levels in the postmortem brains of patients with schizophrenia and exacerbation of symptoms in schizophrenia by PCP. However, the association between KMO deficiency and PCP remains elusive. Here, we demonstrated that a non-effective dose of PCP induced impairment of prepulse inhibition (PPI) in KMO KO mice. KA levels were increased in the prefrontal cortex (PFC) and hippocampus (HIP) of KMO KO mice, but 3-HK levels were decreased. In wild-type C57BL/6 N mice, the PPI impairment induced by PCP is exacerbated by KA, while attenuated by 3-HK, QA and XA. Taken together, KMO KO mice were vulnerable to the PPI impairment induced by PCP through an increase in KA and a decrease in 3-HK, suggesting that an increase in the ratio of KA to 3-HK (QA and XA) may play an important role in the pathophysiology of schizophrenia.
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Marszalek-Grabska M, Zakrocka I, Budzynska B, Marciniak S, Kaszubska K, Lemieszek MK, Winiarczyk S, Kotlinska JH, Rzeski W, Turski WA. Binge-like mephedrone treatment induces memory impairment concomitant with brain kynurenic acid reduction in mice. Toxicol Appl Pharmacol 2022; 454:116216. [PMID: 36057403 DOI: 10.1016/j.taap.2022.116216] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Revised: 08/02/2022] [Accepted: 08/26/2022] [Indexed: 10/31/2022]
Abstract
While mephedrone (4-methylmethcathinone), a synthetic cathinone derivative, is widely abused by adolescents and young adults, the knowledge about its long-term effects on memory processes is limited. Kynurenic acid (KYNA) is a neuroactive metabolite of the kynurenine pathway of tryptophan degradation. KYNA is considered an important endogenous modulator influencing physiological and pathological processes, including learning and memory processes. The aim of this study was to determine whether (A) binge-like mephedrone administration (10.0 and 30.0 mg/kg, intraperitoneally, in 4 doses separated by 2 h) induces memory impairments, assessed 2, 8 and 15 days after mephedrone cessation in the passive avoidance test in mice, and whether (B) KYNA is involved in these memory processes. To clarify the role of KYNA in the mephedrone effects, its level in the murine brain in vivo, and in cortical slices in vitro, as well as the activities of kynurenine aminotransferases (KATs) I and II were assessed. Furthermore, cell line experiments were conducted to investigate the effects of mephedrone on normal human brain cells. Our results showed memory impairments 8 and 15 days after binge-like mephedrone administration. At the same time, reduction in the KYNA level in the murine brain was noted. In vitro studies showed no effect of mephedrone on the production of KYNA in cortical slices or on the activity of the KAT I and II enzymes. Finally, exposure of normal cells to mephedrone in vitro resulted in a modest reduction of cell viability and proliferation.
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Affiliation(s)
- Marta Marszalek-Grabska
- Department of Experimental and Clinical Pharmacology, Medical University, Jaczewskiego 8b, 20-090 Lublin, Poland.
| | - Izabela Zakrocka
- Department of Nephrology, Medical University, Jaczewskiego 8, 20-090 Lublin, Poland
| | - Barbara Budzynska
- Independent Laboratory of Behavioral Studies, Medical University, Chodzki 4a, 20-090 Lublin, Poland
| | - Sebastian Marciniak
- Department of Pharmacology, Medical University, Chodźki 4a, 20-093 Lublin, Poland
| | - Katarzyna Kaszubska
- Department of Pharmacology and Pharmacodynamics, Medical University, Chodzki 4a, 20-093 Lublin, Poland
| | - Marta Kinga Lemieszek
- Department of Medical Biology, Institute of Rural Health, Jaczewskiego 2, 20-090 Lublin, Poland
| | - Sylwia Winiarczyk
- Department of Medical Biology, Institute of Rural Health, Jaczewskiego 2, 20-090 Lublin, Poland
| | - Jolanta H Kotlinska
- Department of Pharmacology and Pharmacodynamics, Medical University, Chodzki 4a, 20-093 Lublin, Poland
| | - Wojciech Rzeski
- Department of Medical Biology, Institute of Rural Health, Jaczewskiego 2, 20-090 Lublin, Poland; Department of Functional Anatomy and Cytobiology, Maria Curie-Skłodowska University, Akademicka 19, 20-033 Lublin, Poland
| | - Waldemar A Turski
- Department of Experimental and Clinical Pharmacology, Medical University, Jaczewskiego 8b, 20-090 Lublin, Poland
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9
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Ding W, Wu F, Zhou S, Li H, Wang R, Ning Y. Increased plasma level of kynurenic acid in drug-free patients with first-episode schizophrenia compared to patients with chronic schizophrenia and healthy controls: preliminary data. Nord J Psychiatry 2022; 76:451-456. [PMID: 34928781 DOI: 10.1080/08039488.2021.1992647] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
BACKGROUND Kynurenic acid (KYNA) is a metabolite of tryptophan (TRP). KYNA levels have been reported with controversial findings in patients with schizophrenia. AIM This study aimed to investigate the probable effects of medication and illness chronicity on peripheral KYNA levels in schizophrenia. METHODS We assessed peripheral (plasma) TRP metabolite levels in 38 drug-free patients with first-episode schizophrenia (FES), 65 patients with chronic schizophrenia (CHS), and 70 healthy controls by using high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS). The symptom severity of patients was evaluated by using the Positive and Negative Syndrome Scale (PANSS). Finally, we analyzed the association of TRP metabolites with symptom severity. RESULTS We found significantly higher KYNA levels in FES patients than in both healthy controls (p < 0.01) and CHS patients (p < 0.05). No significant association was observed between plasma TRP metabolite levels and PANSS scores in either FES or CHS patients. CONCLUSIONS In conclusion, elevated plasma KYNA levels may be a promising biomarker in FES patients. Medication and illness chronicity may affect peripheral KYNA levels with a currently unknown mechanism.
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Affiliation(s)
- Wenhua Ding
- The Affiliated Brain Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China
| | - Fengchun Wu
- The Affiliated Brain Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China
| | - Sumiao Zhou
- The Affiliated Brain Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China
| | - Hehua Li
- The Affiliated Brain Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China
| | - Runhua Wang
- The Affiliated Brain Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China
| | - Yuping Ning
- The Affiliated Brain Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China.,The First School of Clinical Medicine, Southern Medical University, Guangzhou, Guangdong, China
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Hebbrecht K, Morrens M, Giltay EJ, van Nuijs ALN, Sabbe B, van den Ameele S. The Role of Kynurenines in Cognitive Dysfunction in Bipolar Disorder. Neuropsychobiology 2022; 81:184-191. [PMID: 34883494 DOI: 10.1159/000520152] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Accepted: 10/07/2021] [Indexed: 11/19/2022]
Abstract
INTRODUCTION Chronic low-grade inflammation is suggested to play a pathophysiological role in bipolar disorder (BD) and its related cognitive dysfunctions. Although kynurenine (KYN) pathway metabolites are key inflammatory mediators, studies investigating the association between KYN metabolism and cognition in BD are scarce. We aimed to explore the relationship between KYN metabolism and cognitive functioning across different mood states in BD. METHODS Sixty-seven patients with BD (35 depressed and 32 [hypo] manic) and 29 healthy controls were included. Cognitive functioning was assessed at 3 time intervals (baseline, 4, and 8 months) assessing processing speed, sustained attention, verbal memory, working memory, and response inhibition. Plasma samples for quantification of 3-hydroxykynurenine, quinolinic acid, and kynurenic acid (KYNA) were concurrently provided. Linear mixed models were used for statistical analysis. RESULTS The manic group showed deficits in all assessed cognitive domains with the exception of verbal memory at all test moments. The bipolar depression group showed deficits in the processing speed at all test moments. Throughout the whole follow-up period, KYNA was significantly lower in both patient groups than in controls. Only in the bipolar depression group, low KYNA was associated with worse global cognitive functioning (B = 0.114, p = 0.02) and slower processing speed in particular (B = 0.139, p = 0.03). CONCLUSION Only in the bipolar depression group, lower KYNA was associated with worse cognitive functioning. Future large-scale longitudinal studies are warranted to confirm the role of KYN metabolites in cognitive impairment in patients with BD and the possible therapeutic implications of this relationship.
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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.,Department of Psychiatry, University Psychiatric Center KU Leuven, Leuven, 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
| | - 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, The Netherlands
| | - Alexander L N van Nuijs
- Toxicological Centre, Department of Pharmaceutical Sciences, University of Antwerp, Antwerp, Belgium
| | - Bernard Sabbe
- Faculty of Medicine and Health Sciences, Collaborative Antwerp Psychiatric Research Institute (CAPRI), University of Antwerp, Antwerp, Belgium
| | - Seline van den Ameele
- Faculty of Medicine and Health Sciences, Collaborative Antwerp Psychiatric Research Institute (CAPRI), University of Antwerp, Antwerp, Belgium.,Department of Psychiatry, Vrije Universiteit Brussel (VUB), Universitair Ziekenhuis Brussel (UZ Brussel), Brussels, Belgium
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11
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Ostapiuk A, Urbanska EM. Kynurenic acid in neurodegenerative disorders-unique neuroprotection or double-edged sword? CNS Neurosci Ther 2022; 28:19-35. [PMID: 34862742 PMCID: PMC8673711 DOI: 10.1111/cns.13768] [Citation(s) in RCA: 31] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Revised: 10/27/2021] [Accepted: 11/02/2021] [Indexed: 12/24/2022] Open
Abstract
AIMS The family of kynurenine pathway (KP) metabolites includes compounds produced along two arms of the path and acting in clearly opposite ways. The equilibrium between neurotoxic kynurenines, such as 3-hydroxykynurenine (3-HK) or quinolinic acid (QUIN), and neuroprotective kynurenic acid (KYNA) profoundly impacts the function and survival of neurons. This comprehensive review summarizes accumulated evidence on the role of KYNA in Alzheimer's, Parkinson's and Huntington's diseases, and discusses future directions of potential pharmacological manipulations aimed to modulate brain KYNA. DISCUSSION The synthesis of specific KP metabolites is tightly regulated and may considerably vary under physiological and pathological conditions. Experimental data consistently imply that shift of the KP to neurotoxic branch producing 3-HK and QUIN formation, with a relative or absolute deficiency of KYNA, is an important factor contributing to neurodegeneration. Targeting specific brain regions to maintain adequate KYNA levels seems vital; however, it requires the development of precise pharmacological tools, allowing to avoid the potential cognitive adverse effects. CONCLUSIONS Boosting KYNA levels, through interference with the KP enzymes or through application of prodrugs/analogs with high bioavailability and potency, is a promising clinical approach. The use of KYNA, alone or in combination with other compounds precisely influencing specific populations of neurons, is awaiting to become a significant therapy for neurodegenerative disorders.
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Affiliation(s)
- Aleksandra Ostapiuk
- Laboratory of Cellular and Molecular PharmacologyDepartment of Experimental and Clinical PharmacologyMedical University of LublinLublinPoland
- Present address:
Department of Clinical Digestive OncologyKU LeuvenLeuvenBelgium
| | - Ewa M. Urbanska
- Laboratory of Cellular and Molecular PharmacologyDepartment of Experimental and Clinical PharmacologyMedical University of LublinLublinPoland
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12
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Serum kynurenine metabolites might not be associated with risk factors of treatment-resistant schizophrenia. J Psychiatr Res 2022; 145:339-346. [PMID: 34776248 DOI: 10.1016/j.jpsychires.2021.11.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2021] [Revised: 10/11/2021] [Accepted: 11/02/2021] [Indexed: 11/23/2022]
Abstract
BACKGROUND About a third of patients with schizophrenia do not respond adequately to currently available antipsychotics and thus experiences symptoms of greater severity, known as treatment-resistant schizophrenia (TRS). Some evidence suggests that the tryptophan (TRP) pathway (comprising 5-HT and kynurenine sub-pathways) has an important influence on response to antipsychotics. We therefore hypothesized that TRS is linked to metabolites of TRP pathway. METHODS We measured TRP metabolites in 54 patients with TRS and compared them to 49 age- and sex-matched patients who responded to antipsychotics (NTRS), and 62 healthy controls using liquid chromatography-tandem mass spectrometry. Psychopathology and clinical symptoms were assessed by means of schizophrenia positive and negative scales. Working memory abilities, cortical thickness and white matter diffusion tensor imaging fractional anisotropy were appraised in enrolled subjects by neurophysiological tests, as spatial span and digital sequencing tests, and 3T magnetic resonance imaging. RESULTS Patients with TRS had a significantly higher 5-HT/TRP ratio (p = 0.009) than patients with NTRS. However, the two groups did not differ in kynurenine-pathway metabolites or ratios. Additionally, 5-HT/TRP was positively correlated with disorganized symptoms in TRS (r = 0.59, p < 0.001), and negatively correlated with digit-sequencing test scores (r = -0.34, p = 0.02). These correlations were insignificant among patients with NTRS and healthy controls. In patients with TRS, 5-HT/TRP was strongly linked to the right supramarginal cortex (t = -3.2, p = 0.003), and in healthy controls, to the right transverse temporal (t = 3.40, p = 0.001), but significance disappeared after FDR correction. CONCLUSIONS Present results indicate that an upregulated 5-HT biosynthetic pathway can be associated to TRS, suggesting that targeting mechanisms of 5-HT conversion from tryptophan could shed light on the development of new pharmacological approaches of TRS.
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13
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Beggiato S, Ieraci A, Zuccarini M, Di Iorio P, Schwarcz R, Ferraro L. Alterations in rat prefrontal cortex kynurenic acid levels are involved in the enduring cognitive dysfunctions induced by tetrahydrocannabinol exposure during the adolescence. Front Psychiatry 2022; 13:996406. [PMID: 36483135 PMCID: PMC9722723 DOI: 10.3389/fpsyt.2022.996406] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2022] [Accepted: 11/01/2022] [Indexed: 11/23/2022] Open
Abstract
INTRODUCTION Cannabis abuse during adolescence is a risk factor for cognitive impairments in psychiatric disorders later in life. To date, the possible causal relationship between cannabinoids, kynurenic acid (KYNA; i.e., a neuroactive metabolite of tryptophan degradation) and cognition has not been investigated in adolescence. Early exposure to delta 9-tetrahydrocannabinol (THC; i.e., the main psychotropic component of cannabis) causes enduring cognitive deficits, which critically involve impaired glutamatergic function in the prefrontal cortex (PFC). In addition, prenatal cannabis exposure results in enduring increases in PFC KYNA levels. Based on these findings, the effects of chronic THC exposure in rats, during another critical period of neurodevelopment particularly sensitive to perturbation by exogenous stimuli, such as adolescence, have been investigated. METHODS Male Wistar rats were chronically treated with vehicle or ascending intraperitoneal (i.p.) doses of THC starting on postnatal day (PND) 35 until PND 45. In adulthood (PND 75), cognitive assessment (Y-maze) and extracellular KYNA/glutamate levels were measured in the PFC by in vivo microdialysis, before and after a challenge with KYN (5 mg/kg i.p., the biological precursor of KYNA). By using the selective, brain-penetrable KAT II inhibitor PF-04859989, we then examined whether blockade of KYNA neosynthesis prevents the cognitive impairment. RESULTS Compared to vehicle-treated controls, extracellular basal KYNA levels were higher in the PFC of adult rats chronically exposed to THC in adolescence (p < 0.01). No changes were observed in extracellular glutamate levels. Following a challenge with KYN, extracellular KYNA levels similarly increased in both groups (i.e., vehicle- and THC-treated; p < 0.001 and p < 0.01, respectively). Chronic adolescent THC exposure negatively affected short-term memory (reduced spontaneous alternation), in adult animals (p < 0.001), while PF-04859989 (30 mg/kg i.p.) restored the cognitive impairment (p < 0.05). DISCUSSION We propose that the observed alterations in PFC KYNA signaling might be involved in the cognitive dysfunction induced by the exposure to THC during the adolescence. In the translational realm, these experiments raise the prospect of prevention of KYNA neosynthesis as a possible novel approach to counteract some of the detrimental long-term effects of adolescence cannabis use.
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Affiliation(s)
- Sarah Beggiato
- Department of Medical, Oral and Biotechnological Sciences, University of Chieti-Pescara, Chieti, Italy.,Department of Life Sciences and Biotechnologies, University of Ferrara, Ferrara, Italy
| | - Alessandro Ieraci
- Department of Pharmaceutical Sciences, University of Milan, Milan, Italy.,Department of Theoretical and Applied Science, eCampus University, Novedrate, Italy
| | - Mariachiara Zuccarini
- Department of Medical, Oral and Biotechnological Sciences, University of Chieti-Pescara, Chieti, Italy
| | - Patrizia Di Iorio
- Department of Medical, Oral and Biotechnological Sciences, University of Chieti-Pescara, Chieti, Italy
| | - Robert Schwarcz
- Department of Psychiatry, Maryland Psychiatric Research Center, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Luca Ferraro
- Department of Life Sciences and Biotechnologies, University of Ferrara, Ferrara, Italy.,Laboratory for the Technology of Advanced Therapies (LTTA Centre), University of Ferrara, Ferrara, Italy
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14
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Yang Q, Zhang Y, Yang K, Niu Y, Fan F, Chen S, Luo X, Tan S, Wang Z, Tong J, Yang F, Li CSR, Tan Y. Associations of the serum kynurenine pathway metabolites with P50 auditory gating in non-smoking patients with first-episode schizophrenia. Front Psychiatry 2022; 13:1036421. [PMID: 36339840 PMCID: PMC9632432 DOI: 10.3389/fpsyt.2022.1036421] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2022] [Accepted: 10/05/2022] [Indexed: 11/21/2022] Open
Abstract
OBJECTIVE Our study aimed to investigate the associations between the serum level of kynurenine pathway (KP) metabolites and P50 auditory gating in non-smoking patients with first-episode schizophrenia (FES). MATERIALS AND METHODS In this study, 82 non-smoking patients with FES and 73 healthy controls (HC). P50 auditory gating was measured using a fully functional digital 64-channel EEG system, and the components included S1 amplitude, S2 amplitude, gating ratio (S2/S1), and amplitude difference (S1-S2). Serum levels of kynurenine and kynurenine acid were assessed using a combination of liquid chromatography with tandem mass spectrometry. Psychopathology was assessed by the Positive and Negative Syndrome Scale (PANSS). RESULTS The serum kynurenine (251.46 ± 65.93 ng/ml vs. 320.65 ± 65.89 ng/ml, t = -6.38, p < 0.001), and kynurenine acid levels (5.19 ± 2.22 ng/ml vs. 13.26 ± 4.23 ng/ml, t = -14.73, p < 0.001), S1 amplitude [2.88 (1.79, 3.78) μV vs. 3.08 (2.46, 4.56) μV, Z = -2.17, p = 0.030] and S1-S2 [1.60 (0.63, 2.49) μV vs. 1.92 (1.12, 2.93) μV, Z = -2.23, p = 0.026] in patients with FES were significantly lower than those in HC. The serum kynurenine and kynurenine acid levels were negatively associated with S1-S2 (r = -0.32, p = 0.004 and r = -0.42, p < 0.001; respectively) and positively correlated with S2/S1 ratio (r = 0.34, p = 0.002 and r = 0.35, p = 0.002; respectively) in patients. CONCLUSION Our findings suggested that neuroactive metabolites of the KP might play an important role in sensory gating deficit in first episode patients with schizophrenia. Furthermore, metabolites of the KP may be a new target for the treatment of cognitive impairments in schizophrenia.
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Affiliation(s)
- Qingyan Yang
- Peking University Huilongguan Clinical Medical School, Beijing Huilongguan Hospital, Beijing, China
| | - Yong Zhang
- Peking University Huilongguan Clinical Medical School, Beijing Huilongguan Hospital, Beijing, China
| | - Kebing Yang
- Peking University Huilongguan Clinical Medical School, Beijing Huilongguan Hospital, Beijing, China
| | - Yajuan Niu
- Peking University Huilongguan Clinical Medical School, Beijing Huilongguan Hospital, Beijing, China
| | - Fengmei Fan
- Peking University Huilongguan Clinical Medical School, Beijing Huilongguan Hospital, Beijing, China
| | - Song Chen
- Peking University Huilongguan Clinical Medical School, Beijing Huilongguan Hospital, Beijing, China
| | - Xingguang Luo
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, United States
| | - Shuping Tan
- Peking University Huilongguan Clinical Medical School, Beijing Huilongguan Hospital, Beijing, China
| | - Zhiren Wang
- Peking University Huilongguan Clinical Medical School, Beijing Huilongguan Hospital, Beijing, China
| | - Jinghui Tong
- Peking University Huilongguan Clinical Medical School, Beijing Huilongguan Hospital, Beijing, China
| | - Fude Yang
- Peking University Huilongguan Clinical Medical School, Beijing Huilongguan Hospital, Beijing, China
| | - Chiang-Shan R Li
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, United States.,Department of Neuroscience, Yale University School of Medicine, New Haven, CT, United States
| | - Yunlong Tan
- Peking University Huilongguan Clinical Medical School, Beijing Huilongguan Hospital, Beijing, China
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15
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Peripheral kynurenines as biomarkers and targets for prevention and treatment of psychiatric conditions associated with SARS-CoV-2 infection. PERSONALIZED MEDICINE IN PSYCHIATRY 2021. [PMCID: PMC8461219 DOI: 10.1016/j.pmip.2021.100088] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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16
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Büki A, Kekesi G, Horvath G, Vécsei L. A Potential Interface between the Kynurenine Pathway and Autonomic Imbalance in Schizophrenia. Int J Mol Sci 2021; 22:10016. [PMID: 34576179 PMCID: PMC8467675 DOI: 10.3390/ijms221810016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 09/08/2021] [Accepted: 09/09/2021] [Indexed: 02/07/2023] Open
Abstract
Schizophrenia is a neuropsychiatric disorder characterized by various symptoms including autonomic imbalance. These disturbances involve almost all autonomic functions and might contribute to poor medication compliance, worsened quality of life and increased mortality. Therefore, it has a great importance to find a potential therapeutic solution to improve the autonomic disturbances. The altered level of kynurenines (e.g., kynurenic acid), as tryptophan metabolites, is almost the most consistently found biochemical abnormality in schizophrenia. Kynurenic acid influences different types of receptors, most of them involved in the pathophysiology of schizophrenia. Only few data suggest that kynurenines might have effects on multiple autonomic functions. Publications so far have discussed the implication of kynurenines and the alteration of the autonomic nervous system in schizophrenia independently from each other. Thus, the coupling between them has not yet been addressed in schizophrenia, although their direct common points, potential interfaces indicate the consideration of their interaction. The present review gathers autonomic disturbances, the impaired kynurenine pathway in schizophrenia, and the effects of kynurenine pathway on autonomic functions. In the last part of the review, the potential interaction between the two systems in schizophrenia, and the possible therapeutic options are discussed.
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Affiliation(s)
- Alexandra Büki
- Department of Physiology, Albert Szent-Györgyi Medical School, University of Szeged, Dóm tér 10., H-6720 Szeged, Hungary; (A.B.); (G.K.); (G.H.)
| | - Gabriella Kekesi
- Department of Physiology, Albert Szent-Györgyi Medical School, University of Szeged, Dóm tér 10., H-6720 Szeged, Hungary; (A.B.); (G.K.); (G.H.)
| | - Gyongyi Horvath
- Department of Physiology, Albert Szent-Györgyi Medical School, University of Szeged, Dóm tér 10., H-6720 Szeged, Hungary; (A.B.); (G.K.); (G.H.)
| | - László Vécsei
- Department of Neurology, Albert Szent-Györgyi Medical School, University of Szeged, Semmelweis u. 6., H-6725 Szeged, Hungary
- MTA-SZTE Neuroscience Research Group, H-6725 Szeged, Hungary
- Interdisciplinary Excellence Center, Department of Neurology, Albert Szent-Györgyi Medical School, University of Szeged, Semmelweis u. 6., H-6725 Szeged, Hungary
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17
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Imbeault S, Gubert Olivé M, Jungholm O, Erhardt S, Wigström H, Engberg G, Jardemark K. Blockade of KAT II Facilitates LTP in Kynurenine 3-Monooxygenase Depleted Mice. Int J Tryptophan Res 2021; 14:11786469211041368. [PMID: 34483669 PMCID: PMC8411644 DOI: 10.1177/11786469211041368] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Accepted: 08/01/2021] [Indexed: 11/16/2022] Open
Abstract
Excess of brain kynurenic acid (KYNA), a neuroactive metabolite of the kynurenine
pathway, is known to elicit cognitive dysfunction. In the present study, we
investigated spatial working memory in mice with elevated levels of KYNA,
induced by targeted deletion of kynurenine 3-monooxygenase (KMO), as well as
long-term potentiation (LTP) of field excitatory postsynaptic potentials
(fEPSPs) in hippocampal brain slices from these mice. The KMO knock-out
(KMO−/−) mice performed more poorly in the spatial working memory
task as compared to their wild-type (WT) counterparts, as reflected by fewer
correct choices in a T-maze. Both fEPSPs, or LTP, did not significantly differ
between the 2 mouse strains. However, administration of PF-04859989, a
kynurenine aminotransferase (KAT) II inhibitor, limiting the production of KYNA,
facilitated fEPSP and enhanced LTP to a greater extent in hippocampal slices
from KMO−/− mice compared to WT mice. The results of the present
study point to an essential role for KYNA in modulating LTP in the hippocampus
of KMO−/− mice which may account for their dysfunctional spatial
working memory.
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Affiliation(s)
- Sophie Imbeault
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Max Gubert Olivé
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Oscar Jungholm
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Sophie Erhardt
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Holger Wigström
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden.,Department of Medical Biophysics, Institute of Neuroscience and Physiology, University of Gothenburg, Sweden
| | - Göran Engberg
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Kent Jardemark
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
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18
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Mithaiwala MN, Santana-Coelho D, Porter GA, O’Connor JC. Neuroinflammation and the Kynurenine Pathway in CNS Disease: Molecular Mechanisms and Therapeutic Implications. Cells 2021; 10:1548. [PMID: 34205235 PMCID: PMC8235708 DOI: 10.3390/cells10061548] [Citation(s) in RCA: 54] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2021] [Revised: 06/13/2021] [Accepted: 06/15/2021] [Indexed: 12/16/2022] Open
Abstract
Diseases of the central nervous system (CNS) remain a significant health, social and economic problem around the globe. The development of therapeutic strategies for CNS conditions has suffered due to a poor understanding of the underlying pathologies that manifest them. Understanding common etiological origins at the cellular and molecular level is essential to enhance the development of efficacious and targeted treatment options. Over the years, neuroinflammation has been posited as a common link between multiple neurological, neurodegenerative and neuropsychiatric disorders. Processes that precipitate neuroinflammatory conditions including genetics, infections, physical injury and psychosocial factors, like stress and trauma, closely link dysregulation in kynurenine pathway (KP) of tryptophan metabolism as a possible pathophysiological factor that 'fuel the fire' in CNS diseases. In this study, we aim to review emerging evidence that provide mechanistic insights between different CNS disorders, neuroinflammation and the KP. We provide a thorough overview of the different branches of the KP pertinent to CNS disease pathology that have therapeutic implications for the development of selected and efficacious treatment strategies.
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Affiliation(s)
- Mustafa N. Mithaiwala
- Integrated Biomedical Sciences Program, Graduate School of Biomedical Sciences, UT Health San Antonio, San Antonio, TX 78229, USA; (M.N.M.); (D.S.-C.); (G.A.P.)
- Department of Pharmacology, Long School of Medicine, UT Health San Antonio, Mail Code 8864, San Antonio, TX 78229, USA
| | - Danielle Santana-Coelho
- Integrated Biomedical Sciences Program, Graduate School of Biomedical Sciences, UT Health San Antonio, San Antonio, TX 78229, USA; (M.N.M.); (D.S.-C.); (G.A.P.)
- Department of Pharmacology, Long School of Medicine, UT Health San Antonio, Mail Code 8864, San Antonio, TX 78229, USA
| | - Grace A. Porter
- Integrated Biomedical Sciences Program, Graduate School of Biomedical Sciences, UT Health San Antonio, San Antonio, TX 78229, USA; (M.N.M.); (D.S.-C.); (G.A.P.)
- Department of Pharmacology, Long School of Medicine, UT Health San Antonio, Mail Code 8864, San Antonio, TX 78229, USA
| | - Jason C. O’Connor
- Integrated Biomedical Sciences Program, Graduate School of Biomedical Sciences, UT Health San Antonio, San Antonio, TX 78229, USA; (M.N.M.); (D.S.-C.); (G.A.P.)
- Department of Pharmacology, Long School of Medicine, UT Health San Antonio, Mail Code 8864, San Antonio, TX 78229, USA
- Department of Research, Audie L. Murphy VA Hospital, South Texas Veterans Heath System, San Antonio, TX 78229, USA
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19
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Stone TW. Relationships and Interactions between Ionotropic Glutamate Receptors and Nicotinic Receptors in the CNS. Neuroscience 2021; 468:321-365. [PMID: 34111447 DOI: 10.1016/j.neuroscience.2021.06.007] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2021] [Revised: 06/03/2021] [Accepted: 06/04/2021] [Indexed: 02/07/2023]
Abstract
Although ionotropic glutamate receptors and nicotinic receptors for acetylcholine (ACh) have usually been studied separately, they are often co-localized and functionally inter-dependent. The objective of this review is to survey the evidence for interactions between the two receptor families and the mechanisms underlying them. These include the mutual regulation of subunit expression, which change the NMDA:AMPA response balance, and the existence of multi-functional receptor complexes which make it difficult to distinguish between individual receptor sites, especially in vivo. This is followed by analysis of the functional relationships between the receptors from work on transmitter release, cellular electrophysiology and aspects of behavior where these can contribute to understanding receptor interactions. It is clear that nicotinic receptors (nAChRs) on axonal terminals directly regulate the release of glutamate and other neurotransmitters, α7-nAChRs generally promoting release. Hence, α7-nAChR responses will be prevented not only by a nicotinic antagonist, but also by compounds blocking the indirectly activated glutamate receptors. This accounts for the apparent anticholinergic activity of some glutamate antagonists, including the endogenous antagonist kynurenic acid. The activation of presynaptic nAChRs is by the ambient levels of ACh released from pre-terminal synapses, varicosities and glial cells, acting as a 'volume neurotransmitter' on synaptic and extrasynaptic sites. In addition, ACh and glutamate are released as CNS co-transmitters, including 'cholinergic' synapses onto spinal Renshaw cells. It is concluded that ACh should be viewed primarily as a modulator of glutamatergic neurotransmission by regulating the release of glutamate presynaptically, and the location, subunit composition, subtype balance and sensitivity of glutamate receptors, and not primarily as a classical fast neurotransmitter. These conclusions and caveats should aid clarification of the sites of action of glutamate and nicotinic receptor ligands in the search for new centrally-acting drugs.
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Affiliation(s)
- Trevor W Stone
- The Kennedy Institute of Rheumatology, University of Oxford, Oxford OX3 7FY, UK; Institute of Neuroscience, University of Glasgow, G12 8QQ, UK.
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20
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Rentschler KM, Baratta AM, Ditty AL, Wagner NTJ, Wright CJ, Milosavljevic S, Mong JA, Pocivavsek A. Prenatal Kynurenine Elevation Elicits Sex-Dependent Changes in Sleep and Arousal During Adulthood: Implications for Psychotic Disorders. Schizophr Bull 2021; 47:1320-1330. [PMID: 33823027 PMCID: PMC8379538 DOI: 10.1093/schbul/sbab029] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Dysregulation of the kynurenine pathway (KP) of tryptophan catabolism has been implicated in psychotic disorders, including schizophrenia and bipolar disorder. Kynurenic acid (KYNA) is a KP metabolite synthesized by kynurenine aminotransferases (KATs) from its biological precursor kynurenine and acts as an endogenous antagonist of N-methyl-D-aspartate and α7-nicotinic acetylcholine receptors. Elevated KYNA levels found in postmortem brain tissue and cerebrospinal fluid of patients are hypothesized to play a key role in the etiology of cognitive symptoms observed in psychotic disorders. Sleep plays an important role in memory consolidation, and sleep disturbances are common among patients. Yet, little is known about the effect of altered KP metabolism on sleep-wake behavior. We presently utilized a well-established experimental paradigm of embryonic kynurenine (EKyn) exposure wherein pregnant dams are fed a diet laced with kynurenine the last week of gestation and hypothesized disrupted sleep-wake behavior in adult offspring. We examined sleep behavior in adult male and female offspring using electroencephalogram and electromyogram telemetry and determined sex differences in sleep and arousal in EKyn offspring. EKyn males displayed reduced rapid eye movement sleep, while female EKyn offspring were hyperaroused compared to controls. We determined that EKyn males maintain elevated brain KYNA levels, while KYNA levels were unchanged in EKyn females, yet the activity levels of KAT I and KAT II were reduced. Our findings indicate that elevated prenatal kynurenine exposure elicits sex-specific changes in sleep-wake behavior, arousal, and KP metabolism.
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Affiliation(s)
- Katherine M Rentschler
- Department of Pharmacology, Physiology, and Neuroscience, University of South Carolina School of Medicine, Columbia, SC, USA
| | | | - Audrey L Ditty
- Department of Pharmacology, Physiology, and Neuroscience, University of South Carolina School of Medicine, Columbia, SC, USA
| | - Nathan T J Wagner
- Department of Pharmacology, Physiology, and Neuroscience, University of South Carolina School of Medicine, Columbia, SC, USA
| | - Courtney J Wright
- Department of Pharmacology, Physiology, and Neuroscience, University of South Carolina School of Medicine, Columbia, SC, USA
| | - Snezana Milosavljevic
- Department of Pharmacology, Physiology, and Neuroscience, University of South Carolina School of Medicine, Columbia, SC, USA
| | - Jessica A Mong
- Department of Pharmacology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Ana Pocivavsek
- Department of Pharmacology, Physiology, and Neuroscience, University of South Carolina School of Medicine, Columbia, SC, USA,To whom correspondence should be addressed; tel: (803) 216–3509, fax: 803-216-3538, e-mail:
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21
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Dissociating direct and indirect effects: a theoretical framework of how latent toxoplasmosis affects cognitive profile across the lifespan. Neurobiol Aging 2021; 102:119-128. [PMID: 33765425 DOI: 10.1016/j.neurobiolaging.2021.02.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Revised: 01/25/2021] [Accepted: 02/07/2021] [Indexed: 12/16/2022]
Abstract
About one-third of the world's population has latent toxoplasmosis, which is typically most prevalent in old age due to its lifelong persistence. Most infected people do not reveal clinically relevant symptoms, but T. gondii might trigger cognitive changes in otherwise asymptomatic individuals. As intact cognitive processes are essential for various achievements and successful aging, this review focuses on the cognitive profile associated with latent toxoplasmosis across the lifespan. It could be explained by a shift in balance between direct effects (increased dopamine synthesis) and indirect effects (neurodegeneration and chronic inflammation, which can decrease dopamine levels). Based thereon, we provide a possibly comprehensive framework of how T. gondii can differently affect cognitive performance across the lifespan (i.e., from increased catecholaminergic signaling in young age to decreased signaling in old age). We outline how future studies may inform our knowledge on the role of individual differences in response to T. gondii and how longitudinal studies can help trace the temporal dynamics in the shift of the balance between direct and indirect effects.
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Sellgren CM, Imbeault S, Larsson MK, Oliveros A, Nilsson IAK, Codeluppi S, Orhan F, Bhat M, Tufvesson-Alm M, Gracias J, Kegel ME, Zheng Y, Faka A, Svedberg M, Powell SB, Caldwell S, Kamenski ME, Vawter MP, Schulmann A, Goiny M, Svensson CI, Hökfelt T, Schalling M, Schwieler L, Cervenka S, Choi DS, Landén M, Engberg G, Erhardt S. GRK3 deficiency elicits brain immune activation and psychosis. Mol Psychiatry 2021; 26:6820-6832. [PMID: 33976392 PMCID: PMC8760053 DOI: 10.1038/s41380-021-01106-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/18/2020] [Accepted: 04/07/2021] [Indexed: 02/03/2023]
Abstract
The G protein-coupled receptor kinase (GRK) family member protein GRK3 has been linked to the pathophysiology of schizophrenia and bipolar disorder. Expression, as well as protein levels, of GRK3 are reduced in post-mortem prefrontal cortex of schizophrenia subjects. Here, we investigate functional behavior and neurotransmission related to immune activation and psychosis using mice lacking functional Grk3 and utilizing a variety of methods, including behavioral, biochemical, electrophysiological, molecular, and imaging methods. Compared to wildtype controls, the Grk3-/- mice show a number of aberrations linked to psychosis, including elevated brain levels of IL-1β, increased turnover of kynurenic acid (KYNA), hyper-responsiveness to D-amphetamine, elevated spontaneous firing of midbrain dopamine neurons, and disruption in prepulse inhibition. Analyzing human genetic data, we observe a link between psychotic features in bipolar disorder, decreased GRK expression, and increased concentration of CSF KYNA. Taken together, our data suggest that Grk3-/- mice show face and construct validity relating to the psychosis phenotype with glial activation and would be suitable for translational studies of novel immunomodulatory agents in psychotic disorders.
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Affiliation(s)
- Carl M. Sellgren
- grid.4714.60000 0004 1937 0626Department of Physiology & Pharmacology, Karolinska Institutet, Stockholm, Sweden ,grid.4714.60000 0004 1937 0626Centre for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm & Stockholm Health Care Services, Region Stockholm, Sweden
| | - Sophie Imbeault
- grid.4714.60000 0004 1937 0626Department of Physiology & Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Markus K. Larsson
- grid.4714.60000 0004 1937 0626Department of Physiology & Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Alfredo Oliveros
- grid.66875.3a0000 0004 0459 167XDepartment of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic College of Medicine, Rochester, MN USA
| | - Ida A. K. Nilsson
- grid.4714.60000 0004 1937 0626Translational Psychiatry, Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden ,grid.24381.3c0000 0000 9241 5705Center for Molecular Medicine, Karolinska University Hospital, Stockholm, Sweden
| | - Simone Codeluppi
- grid.4714.60000 0004 1937 0626Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Funda Orhan
- grid.4714.60000 0004 1937 0626Department of Physiology & Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Maria Bhat
- grid.418151.80000 0001 1519 6403Research and Development, Innovative Medicines, Personalised Healthcare and Biomarkers, Translational Science Centre, Science for Life Laboratory, AstraZeneca, Solna, Sweden ,grid.4714.60000 0004 1937 0626Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Maximilian Tufvesson-Alm
- grid.4714.60000 0004 1937 0626Department of Physiology & Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Jessica Gracias
- grid.4714.60000 0004 1937 0626Department of Physiology & Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Magdalena E. Kegel
- grid.4714.60000 0004 1937 0626Department of Physiology & Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Yiran Zheng
- grid.4714.60000 0004 1937 0626Department of Physiology & Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Anthi Faka
- grid.4714.60000 0004 1937 0626Department of Physiology & Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Marie Svedberg
- grid.4714.60000 0004 1937 0626Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Susan B. Powell
- grid.266100.30000 0001 2107 4242Department of Psychiatry, University of California San Diego, La Jolla, CA USA
| | - Sorana Caldwell
- grid.266100.30000 0001 2107 4242Department of Psychiatry, University of California San Diego, La Jolla, CA USA
| | - Mary E. Kamenski
- grid.266100.30000 0001 2107 4242Department of Psychiatry, University of California San Diego, La Jolla, CA USA
| | - Marquis P. Vawter
- grid.266093.80000 0001 0668 7243Functional Genomics Laboratory, Department of Psychiatry and Human Behavior, University of California Irvine School of Medicine, Irvine, CA USA
| | - Anton Schulmann
- grid.416868.50000 0004 0464 0574Human Genetics Branch, National Institute of Mental Health, Bethesda, MD USA
| | - Michel Goiny
- grid.4714.60000 0004 1937 0626Department of Physiology & Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Camilla I. Svensson
- grid.4714.60000 0004 1937 0626Department of Physiology & Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Tomas Hökfelt
- grid.4714.60000 0004 1937 0626Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Martin Schalling
- grid.4714.60000 0004 1937 0626Translational Psychiatry, Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden ,grid.24381.3c0000 0000 9241 5705Center for Molecular Medicine, Karolinska University Hospital, Stockholm, Sweden
| | - Lilly Schwieler
- grid.4714.60000 0004 1937 0626Department of Physiology & Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Simon Cervenka
- grid.4714.60000 0004 1937 0626Centre for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm & Stockholm Health Care Services, Region Stockholm, Sweden
| | - Doo-Sup Choi
- grid.66875.3a0000 0004 0459 167XDepartment of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic College of Medicine, Rochester, MN USA ,grid.66875.3a0000 0004 0459 167XDepartment of Psychiatry and Psychology, Mayo Clinic College of Medicine, Rochester, MN USA
| | - Mikael Landén
- grid.8761.80000 0000 9919 9582Institute of Neuroscience and Physiology, University of Gothenburg, Gothenburg, Sweden ,grid.4714.60000 0004 1937 0626Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
| | - Göran Engberg
- Department of Physiology & Pharmacology, Karolinska Institutet, Stockholm, Sweden.
| | - Sophie Erhardt
- grid.4714.60000 0004 1937 0626Department of Physiology & Pharmacology, Karolinska Institutet, Stockholm, Sweden
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Jorratt P, Hoschl C, Ovsepian SV. Endogenous antagonists of N-methyl-d-aspartate receptor in schizophrenia. Alzheimers Dement 2020; 17:888-905. [PMID: 33336545 DOI: 10.1002/alz.12244] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Accepted: 10/24/2020] [Indexed: 12/28/2022]
Abstract
Schizophrenia is a chronic neuropsychiatric brain disorder that has devastating personal impact and rising healthcare costs. Dysregulation of glutamatergic neurotransmission has been implicated in the pathobiology of the disease, attributed largely to the hypofunction of the N-methyl-d-aspartate (NMDA) receptor. Currently, there is a major gap in mechanistic analysis as to how endogenous modulators of the NMDA receptors contribute to the onset and progression of the disease. We present a systematic review of the neurobiology and the role of endogenous NMDA receptor antagonists in animal models of schizophrenia, and in patients. We discuss their neurochemical origin, release from neurons and glia with action mechanisms, and functional effects, which might contribute toward the impairment of neuronal processes underlying this complex pathological state. We consider clinical evidence suggesting dysregulations of endogenous NMDA receptor in schizophrenia, and highlight the pressing need in future studies and emerging directions, to restore the NMDA receptor functions for therapeutic benefits.
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Affiliation(s)
- Pascal Jorratt
- Department of Experimental Neurobiology, National Institute of Mental Health, Klecany, Czech Republic.,Department of Psychiatry and Medical Psychology, Third Faculty of Medicine, Charles University, Prague 10, Czech Republic
| | - Cyril Hoschl
- Department of Experimental Neurobiology, National Institute of Mental Health, Klecany, Czech Republic.,Department of Psychiatry and Medical Psychology, Third Faculty of Medicine, Charles University, Prague 10, Czech Republic
| | - Saak V Ovsepian
- Department of Experimental Neurobiology, National Institute of Mental Health, Klecany, Czech Republic.,Department of Psychiatry and Medical Psychology, Third Faculty of Medicine, Charles University, Prague 10, Czech Republic
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24
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Pearce BD, Massa N, Goldsmith DR, Gandhi ZH, Hankus A, Alrohaibani A, Goel N, Cuthbert B, Fargotstein M, Barr DB, Panuwet P, Brown VM, Duncan E. Toxoplasma gondii Effects on the Relationship of Kynurenine Pathway Metabolites to Acoustic Startle Latency in Schizophrenia vs. Control Subjects. Front Psychiatry 2020; 11:552743. [PMID: 33329089 PMCID: PMC7715008 DOI: 10.3389/fpsyt.2020.552743] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Accepted: 10/20/2020] [Indexed: 01/04/2023] Open
Abstract
Background: Chronic infection with Toxoplasma gondii (TOXO) results in microcysts in the brain that are controlled by inflammatory activation and subsequent changes in the kynurenine pathway. TOXO seropositivity is associated with a heightened risk of schizophrenia (SCZ) and with cognitive impairments. Latency of the acoustic startle response, a putative index of neural processing speed, is slower in SCZ. SCZ subjects who are TOXO seropositive have slower latency than SCZ subjects who are TOXO seronegative. We assessed the relationship between kynurenine pathway metabolites and startle latency as a potential route by which chronic TOXO infection can lead to cognitive slowing in SCZ. Methods: Fourty-seven SCZ subjects and 30 controls (CON) were tested on a standard acoustic startle paradigm. Kynurenine pathway metabolites were measured using liquid chromatography-tandem mass spectrometry were kynurenine (KYN), tryptophan (TRYP), 3-hydroxyanthranilic acid (3-OHAA), anthranilic acid (AA), and kynurenic acid (KYNA). TOXO status was determined by IgG ELISA. Results: In univariate ANCOVAs on onset and peak latency with age and log transformed startle magnitude as covariates, both onset latency [F(1,61) = 5.76; p = 0.019] and peak latency [F(1,61) = 4.34; p = 0.041] were slower in SCZ than CON subjects. In stepwise backward linear regressions after stratification by Diagnosis, slower onset latency in SCZ subjects was predicted by higher TRYP (B = 0.42; p = 0.008) and 3-OHAA:AA (B = 3.68; p = 0.007), and lower KYN:TRYP (B = -185.42; p = 0.034). In regressions with peak latency as the dependent variable, slower peak latency was predicted by higher TRYP (B = 0.47; p = 0.013) and 3-OHAA:AA ratio (B = 4.35; p = 0.010), and by lower KYNA (B = -6.67; p = 0.036). In CON subjects neither onset nor peak latency was predicted by any KYN metabolites. In regressions stratified by TOXO status, in TOXO positive subjects, slower peak latency was predicted by lower concentrations of KYN (B = -8.08; p = 0.008), KYNA (B = -10.64; p = 0.003), and lower KYN:TRYP ratios (B = -347.01; p = 0.03). In TOXO negative subjects neither onset nor peak latency was predicted by any KYN metabolites. Conclusions: KYN pathway markers predict slowing of startle latency in SCZ subjects and in those with chronic TOXO infection, but this is not seen in CON subjects nor TOXO seronegative subjects. These findings coupled with prior work indicating a relationship of slower latency with SCZ and TOXO infection suggest that alterations in KYN pathway markers may be a mechanism by which neural processing speed, as indexed by startle latency, is affected in these subjects.
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Affiliation(s)
- Bradley D. Pearce
- Rollins School of Public Health, Emory University, Atlanta, GA, United States
| | - Nicholas Massa
- Rollins School of Public Health, Emory University, Atlanta, GA, United States
- Atlanta Veterans Affairs Health Care System, Decatur, GA, United States
| | - David R. Goldsmith
- Department of Psychiatry and Behavioral Sciences, Emory University School of Medicine, Atlanta, GA, United States
| | - Zeal H. Gandhi
- Rollins School of Public Health, Emory University, Atlanta, GA, United States
| | - Allison Hankus
- Rollins School of Public Health, Emory University, Atlanta, GA, United States
| | | | - Neha Goel
- Rollins School of Public Health, Emory University, Atlanta, GA, United States
| | - Bruce Cuthbert
- Atlanta Veterans Affairs Health Care System, Decatur, GA, United States
- Department of Psychiatry and Behavioral Sciences, Emory University School of Medicine, Atlanta, GA, United States
| | - Molly Fargotstein
- Department of Psychiatry and Behavioral Sciences, Emory University School of Medicine, Atlanta, GA, United States
| | - Dana Boyd Barr
- Rollins School of Public Health, Emory University, Atlanta, GA, United States
| | - Parinya Panuwet
- Rollins School of Public Health, Emory University, Atlanta, GA, United States
| | - Victoria M. Brown
- Rollins School of Public Health, Emory University, Atlanta, GA, United States
| | - Erica Duncan
- Atlanta Veterans Affairs Health Care System, Decatur, GA, United States
- Department of Psychiatry and Behavioral Sciences, Emory University School of Medicine, Atlanta, GA, United States
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25
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Repeated administration of LPS exaggerates amphetamine-induced locomotor response and causes learning deficits in mice. J Neuroimmunol 2020; 349:577401. [PMID: 33002724 DOI: 10.1016/j.jneuroim.2020.577401] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Revised: 09/03/2020] [Accepted: 09/18/2020] [Indexed: 12/12/2022]
Abstract
Immune activation contributes to the pathophysiology of psychiatric disorders. Administration of a single dose of lipopolysaccharides (LPS) has been shown to induce depressive- and anxiety-like behaviors in rodents through activation of the kynurenine pathway, increasing levels of the N-methyl-d-aspartate (NMDA) receptor agonist quinolinic acid. Conversely, repeated administration of LPS produces increased levels of the NMDA receptor antagonist kynurenic acid. Here we show that repeated LPS administration increases sensitivity to D-amphetamine and produces cognitive deficits and anxiety-like behavior. Together, our behavioral data suggests that repeated LPS administration may be useful to study the contribution of inflammation to psychiatric disorders such as schizophrenia.
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26
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Blanco-Ayala T, Sathyasaikumar KV, Uys JD, Pérez-de-la-Cruz V, Pidugu LS, Schwarcz R. N-Acetylcysteine Inhibits Kynurenine Aminotransferase II. Neuroscience 2020; 444:160-169. [PMID: 32768617 DOI: 10.1016/j.neuroscience.2020.07.049] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 07/08/2020] [Accepted: 07/28/2020] [Indexed: 12/22/2022]
Abstract
The tryptophan metabolite kynurenic acid (KYNA) may play an important role in normal and abnormal cognitive processes, most likely by interfering with α7 nicotinic and NMDA receptor function. KYNA is formed from its immediate precursor kynurenine either by non-enzymatic oxidation or through irreversible transamination by kynurenine aminotransferases. In the mammalian brain, kynurenine aminotransferase II (KAT II) is the principal enzyme responsible for the neosynthesis of rapidly mobilizable KYNA, and therefore constitutes an attractive target for pro-cognitive interventions. N-acetylcysteine (NAC), a brain-penetrant drug with pro-cognitive efficacy in humans, has been proposed to exert its actions by increasing the levels of the anti-oxidant glutathione (GSH) in the brain. We report here that NAC, but not GSH, inhibits KAT II activity in brain tissue homogenates from rats and humans with IC50 values in the high micromolar to low millimolar range. With similar potency, the drug interfered with the de novo formation of KYNA in rat brain slices, and NAC was a competitive inhibitor of recombinant human KAT II (Ki: 450 μM). Furthermore, GSH failed to S-glutathionylate recombinant human KAT II treated with the dithiocarbamate drug disulfiram. Shown by microdialysis in the prefrontal cortex of rats treated with kynurenine (50 mg/kg, i.p.), peripheral administration of NAC (500 mg/kg, i.p., 120 and 60 min before the application of kynurenine) reduced KYNA neosynthesis by ∼50%. Together, these results suggest that NAC exerts its neurobiological effects at least in part by reducing cerebral KYNA formation via KAT II inhibition.
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Affiliation(s)
- T Blanco-Ayala
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD, USA
| | - K V Sathyasaikumar
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD, USA
| | - J D Uys
- Department of Cellular and Molecular Pharmacology and Experimental Therapeutics, Medical University of South Carolina, Charleston, SC, USA
| | - V Pérez-de-la-Cruz
- Laboratorio de Neurobioquimica y Conducta, Instituto Nacional de Neurología y Neurocirugía Manuel Velasco Suárez, S.S.A. Ciudad de México, Mexico
| | - L S Pidugu
- Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - R Schwarcz
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD, USA.
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27
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Buck SA, Baratta AM, Pocivavsek A. Exposure to elevated embryonic kynurenine in rats: Sex-dependent learning and memory impairments in adult offspring. Neurobiol Learn Mem 2020; 174:107282. [PMID: 32738461 DOI: 10.1016/j.nlm.2020.107282] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Revised: 07/21/2020] [Accepted: 07/25/2020] [Indexed: 12/14/2022]
Abstract
Distinct abnormalities in kynurenine pathway (KP) metabolism have been reported in various psychiatric disorders, including schizophrenia (SZ). Kynurenic acid (KYNA), a neuroactive metabolite of the KP, is elevated in individuals diagnosed with SZ and has been linked to cognitive impairments seen in the disorder. To further understand the role of KYNA in SZ etiology, we developed a prenatal insult model where kynurenine (100 mg/day) is fed to pregnant Wistar rats from embryonic day (ED) 15 to ED 22. As sex differences in the prevalence and severity of SZ have been observed, we presently investigated the impact of prenatal kynurenine exposure on KP metabolism and spatial learning and memory in male and female offspring. Specifically, brain tissue and plasma from offspring (control: ECon; kynurenine-treated: EKyn) in prepuberty (postnatal day (PD) 21), adolescence (PD 32-35), and adulthood (PD 56-85) were collected. Separate cohorts of adult offspring were tested in the Barnes maze to assess hippocampus- and prefrontal cortex-mediated learning and memory. Plasma tryptophan, kynurenine, and KYNA were unchanged between ECon and EKyn offspring across all three ages. Hippocampal and frontal cortex KYNA were elevated in male EKyn offspring only in adulthood, compared to ECon, while brain KYNA levels were unchanged in adult females. Male EKyn offspring were significantly impaired during acquisition of the Barnes maze and during reversal learning in the task. In female EKyn offspring, learning and memory remained relatively intact. Taken together, our data demonstrate that exposure to elevated kynurenine during the last week of gestation results in intriguing sex differences and further support the EKyn model as an attractive tool to study the pathophysiology of schizophrenia.
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Affiliation(s)
- Silas A Buck
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Annalisa M Baratta
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Ana Pocivavsek
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD, USA; Department of Pharmacology, Physiology, and Neuroscience, University of South Carolina School of Medicine, Columbia, SC, USA.
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Prenatal THC exposure raises kynurenic acid levels in the prefrontal cortex of adult rats. Prog Neuropsychopharmacol Biol Psychiatry 2020; 100:109883. [PMID: 32032697 PMCID: PMC7260707 DOI: 10.1016/j.pnpbp.2020.109883] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Revised: 01/31/2020] [Accepted: 02/03/2020] [Indexed: 02/08/2023]
Abstract
Cannabis remains one of the most widely used illicit drugs during pregnancy. The main psychoactive component of marijuana (Δ9-tetrahydrocannabinol, THC) is correlated with untoward physiological effects in the offspring. Neurobehavioral and cognitive impairments have been reported in longitudinal studies on children and adolescents prenatally exposed to marijuana, and a link to psychiatric disorders has been proposed. Interestingly, the deleterious effects of prenatal cannabis use are similar to those observed in adult rats prenatally exposed to (L)-kynurenine, the direct bioprecursor of the neuroactive metabolite kynurenic acid (KYNA). We therefore investigated whether alterations in KYNA levels in the rat brain might play a role in the long-term consequences of prenatal cannabinoid exposure. Pregnant Wistar rats were treated daily with THC [5 mg/kg, p.o.] from gestational day (GD)5 through GD20. Using in vivo microdialysis in the medial prefrontal cortex, adult animals were then used to determine the extracellular levels of KYNA and glutamate. Compared to controls, extracellular basal KYNA levels were higher, and basal glutamate levels were lower, in prenatally THC-exposed rats. These rats also showed abnormal short-term memory. Following an additional acute challenge with a low dose of kynurenine (5 mg/kg i.p.) in adulthood, the increase in extracellular KYNA levels in the mPFC was more pronounced in in prenatally THC-exposed rats. These effects could be causally related to the cognitive dysfunction seen in prenatally THC-exposed rats. In the translational realm, these experiments raise the prospect of prevention of KYNA neosynthesis as a promising novel approach to combat some of the detrimental long-term effects of prenatal cannabis use.
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Activation of alpha7 nicotinic and NMDA receptors is necessary for performance in a working memory task. Psychopharmacology (Berl) 2020; 237:1723-1735. [PMID: 32162104 PMCID: PMC7313359 DOI: 10.1007/s00213-020-05495-y] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Accepted: 02/19/2020] [Indexed: 10/24/2022]
Abstract
RATIONALE Working memory deficits are present in schizophrenia (SZ) but remain insufficiently resolved by medications. Similar cognitive dysfunctions can be produced acutely in animals by elevating brain levels of kynurenic acid (KYNA). KYNA's effects may reflect interference with the function of both the α7 nicotinic acetylcholine receptor (α7nAChR) and the glycineB site of the NMDA receptor. OBJECTIVES The aim of the present study was to examine, using pharmacological tools, the respective roles of these two receptor sites on performance in a delayed non-match-to-position working memory (WM) task (DNMTP). METHODS DNMTP consisted of 120 trials/session (5, 10, and 15 s delays). Rats received two doses (25 or 100 mg/kg, i.p.) of L-kynurenine (KYN; bioprecursor of KYNA) or L-4-chlorokynurenine (4-Cl-KYN; bioprecursor of the selective glycineB site antagonist 7-Cl-kynurenic acid). Attenuation of KYN- or 4-Cl-KYN-induced deficits was assessed by co-administration of galantamine (GAL, 3 mg/kg) or PAM-2 (1 mg/kg), two positive modulators of α7nAChR function. Reversal of 4-Cl-KYN-induced deficits was examined using D-cycloserine (DCS; 30 mg/kg), a partial agonist at the glycineB site. RESULTS Both KYN and 4-Cl-KYN administration produced dose-related deficits in DNMTP accuracy that were more severe at the longer delays. In KYN-treated rats, these deficits were reversed to control levels by GAL or PAM-2 but not by DCS. In contrast, DCS eliminated performance deficits in 4-Cl-KYN-treated animals. CONCLUSIONS These experiments reveal that both α7nAChR and NMDAR activity are necessary for normal WM accuracy. They provide substantive new support for the therapeutic potential of positive modulators at these two receptor sites in SZ and other major brain diseases.
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Possibility of Amino Acid Treatment to Prevent the Psychiatric Disorders via Modulation of the Production of Tryptophan Metabolite Kynurenic Acid. Nutrients 2020; 12:nu12051403. [PMID: 32414200 PMCID: PMC7284450 DOI: 10.3390/nu12051403] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2020] [Revised: 05/09/2020] [Accepted: 05/12/2020] [Indexed: 01/06/2023] Open
Abstract
Kynurenic acid, a metabolite of the kynurenine pathway of tryptophan catabolism, acts as an antagonist for both the α7 nicotinic acetylcholine receptor and glycine coagonist sites of the N-methyl-d-aspartic acid receptor at endogenous brain concentrations. Elevation of brain kynurenic acid levels reduces the release of neurotransmitters such as dopamine and glutamate, and kynurenic acid is considered to be involved in psychiatric disorders such as schizophrenia and depression. Thus, the control of kynurenine pathway, especially kynurenic acid production, in the brain is an important target for the improvement of brain function or the effective treatment of brain disorders. Astrocytes uptake kynurenine, the immediate precursor of kynurenic acid, via large neutral amino acid transporters, and metabolize kynurenine to kynurenic acid by kynurenine aminotransferases. The former transport both branched-chain and aromatic amino acids, and the latter have substrate specificity for amino acids and their metabolites. Recent studies have suggested the possibility that amino acids may suppress kynurenic acid production via the blockade of kynurenine transport or via kynurenic acid synthesis reactions. This approach may be useful in the treatment and prevention of neurological and psychiatric diseases associated with elevated kynurenic acid levels.
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De Picker L, Fransen E, Coppens V, Timmers M, de Boer P, Oberacher H, Fuchs D, Verkerk R, Sabbe B, Morrens M. Immune and Neuroendocrine Trait and State Markers in Psychotic Illness: Decreased Kynurenines Marking Psychotic Exacerbations. Front Immunol 2020; 10:2971. [PMID: 32010121 PMCID: PMC6978914 DOI: 10.3389/fimmu.2019.02971] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Accepted: 12/03/2019] [Indexed: 01/18/2023] Open
Abstract
Objective: Different patterns of immune system upregulation are present in the acute vs. post-treatment states of psychotic illness. We explored the existence of state and trait markers in the peripheral immune system and two immune-associated neuroendocrine pathways (IDO and GTP-CH1 pathway) in a longitudinal sample of psychosis patients. We also evaluated the association of these markers with neuropsychiatric symptomatology. Method: Plasma concentrations of peripheral blood markers were measured in a transdiagnostic group of 49 inpatients with acute psychosis and 52 matched healthy control subjects. Samples were obtained in patients within 48 h after hospital admission for an acute psychotic episode (before initiation of antipsychotics), after 1-2 weeks and again after 8 weeks of treatment. Kynurenine, kynurenic acid (KA), 3-hydroxykynurenine (3-HK), quinolinic acid (QA), phenylalanine, tyrosine, nitrite, and neopterin were measured using HPLC and LC-MS/MS analysis. Concentrations of CRP, CCL2 (MCP1) and cytokines were determined with multiplex immunoassay. PANSS interviews and cognitive tests were performed at baseline and follow-up. Mixed model analyses were used to identify trait and state markers. Results: Patients had significantly higher plasma concentrations of CRP, CCL2, IL1RA, and lower concentrations of KA and KA/Kyn at all time points (F7.5-17.5, all p < 0.001). Increased concentrations of IL6, IL8, IL1RA, TNFα, and CCL2 and decreased QA and 3-HK (F8.7-21.0, all p < 0.005) were found in the acute psychotic state and normalized after treatment. Low nitrite concentrations at admission rose sharply after initiation of antipsychotic medication (F42.4, p < 0.001). PANSS positive scale scores during the acute episode correlated with pro-inflammatory immune markers (r ≥ |0.5|), while negative scale scores correlated inversely with IDO pathway markers (r ≥ |0.4|). Normalization of KA and 3-HK levels between admission and follow-up corresponded to a larger improvement of negative symptoms (r = 0.5, p < 0.030) A reverse association was found between relative improvement of SDST scores and decreasing KA levels (r = 0.5, p < 0.010). Conclusion: The acute psychotic state is marked by state-specific increases of immune markers and decreases in peripheral IDO pathway markers. Increased CRP, CCL2, and IL1RA, and decreased KA and KA/Kyn are trait markers of psychotic illness.
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Affiliation(s)
- Livia De Picker
- Faculty of Medicine and Health Sciences, Collaborative Antwerp Psychiatric Research Institute, University of Antwerp, Antwerp, Belgium.,University Department of Psychiatry, Campus Duffel, Antwerp, Belgium
| | - Erik Fransen
- StatUa Center for Statistics, University of Antwerp, Antwerp, Belgium
| | - Violette Coppens
- Faculty of Medicine and Health Sciences, Collaborative Antwerp Psychiatric Research Institute, University of Antwerp, Antwerp, Belgium.,University Department of Psychiatry, Campus Duffel, Antwerp, Belgium
| | - Maarten Timmers
- Janssen Research and Development, Janssen Pharmaceutica N.V., Beerse, Belgium.,Reference Center for Biological Markers of Dementia (BIODEM), Institute Born-Bunge, University of Antwerp, Antwerp, Belgium
| | - Peter de Boer
- Janssen Research and Development, Janssen Pharmaceutica N.V., Beerse, Belgium
| | - Herbert Oberacher
- Core Facility Metabolomics, Institute of Legal Medicine, Medical University of Innsbruck, Innsbruck, Austria
| | - Dietmar Fuchs
- Biocenter, Division of Biological Chemistry, Medical University of Innsbruck, Innsbruck, Austria
| | - Robert Verkerk
- Department of Pharmaceutical Sciences, University of Antwerp, Antwerp, Belgium
| | - Bernard Sabbe
- Faculty of Medicine and Health Sciences, Collaborative Antwerp Psychiatric Research Institute, University of Antwerp, Antwerp, Belgium.,University Department of Psychiatry, Campus Duffel, Antwerp, Belgium
| | - Manuel Morrens
- Faculty of Medicine and Health Sciences, Collaborative Antwerp Psychiatric Research Institute, University of Antwerp, Antwerp, Belgium.,University Department of Psychiatry, Campus Duffel, Antwerp, Belgium
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Abstract
The kynurenine pathway (KP) plays a critical role in generating cellular energy in the form of nicotinamide adenine dinucleotide (NAD+). Because energy requirements are substantially increased during an immune response, the KP is a key regulator of the immune system. Perhaps more importantly in the context of psychiatry, many kynurenines are neuroactive, modulating neuroplasticity and/or exerting neurotoxic effects in part through their effects on NMDA receptor signaling and glutamatergic neurotransmission. As such, it is not surprising that the kynurenines have been implicated in psychiatric illness in the context of inflammation. However, because of their neuromodulatory properties, the kynurenines are not just additional members of a list of inflammatory mediators linked with psychiatric illness, but in preclinical studies have been shown to be necessary components of the behavioral analogs of depression and schizophrenia-like cognitive deficits. Further, as the title suggests, the KP is regulated by, and in turn regulates multiple other physiological systems that are commonly disrupted in psychiatric disorders, including endocrine, metabolic, and hormonal systems. This review provides a broad overview of the mechanistic pathways through which the kynurenines interact with these systems, thus impacting emotion, cognition, pain, metabolic function, and aging, and in so doing potentially increasing the risk of developing psychiatric disorders. Novel therapeutic approaches targeting the KP are discussed. Moreover, electroconvulsive therapy, ketamine, physical exercise, and certain non-steroidal anti-inflammatories have been shown to alter kynurenine metabolism, raising the possibility that kynurenine metabolites may have utility as treatment response or therapeutic monitoring biomarkers.
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Affiliation(s)
- Jonathan Savitz
- Laureate Institute for Brain Research, Tulsa, OK, USA.
- Oxley College of Health Sciences, The University of Tulsa, Tulsa, OK, USA.
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Huang X, Ding W, Wu F, Zhou S, Deng S, Ning Y. Increased Plasma Kynurenic Acid Levels are Associated with Impaired Attention/Vigilance and Social Cognition in Patients with Schizophrenia. Neuropsychiatr Dis Treat 2020; 16:263-271. [PMID: 32158211 PMCID: PMC6986175 DOI: 10.2147/ndt.s239763] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2019] [Accepted: 01/13/2020] [Indexed: 01/10/2023] Open
Abstract
OBJECTIVE Preclinical studies have reported that abnormal kynurenic acid (KYNA) may play a role in cognitive deficits. Schizophrenia (SCZ) is characterized by a wide range of cognitive deficits that may evolve from abnormal KYNA. This study aimed to explore the relationship between KYNA and cognitive impairment in SCZ, which has not yet been reported. METHODS We recruited 30 SCZ patients and 34 healthy controls, measured clinical symptoms by using the Positive and Negative Syndrome Scale and performed cognitive tests using the MATRICS Consensus Cognitive Battery (MCCB). Plasma levels of tryptophan, kynurenine, and KYNA were determined by high-performance liquid chromatography-tandem mass spectrometry. RESULTS We found that plasma KYNA levels were significantly higher in patients than in healthy controls (p=0.009). The cognitive performance of patients in the total MCCB scores and the scores of all subscales were significantly lower than those in healthy controls (all P < 0.01). Correlation analysis showed that KYNA levels were negatively correlated with attention/vigilance (r=-0.457, p=0.019) and social cognition (r=-0.481, p=0.013) only in SCZ patients. CONCLUSION Our results indicate that elevated plasma KYNA levels may serve as a biomarker of cognitive impairment in SCZ patients.
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Affiliation(s)
- Xingbing Huang
- First School of Clinical Medicine, Southern Medical University, Guangzhou, Guangdong, People's Republic of China.,The Affiliated Brain Hospital of Guangzhou Medical University (Guangzhou Huiai Hospital), Guangzhou, Guangdong, People's Republic of China
| | - Wenhua Ding
- The Affiliated Brain Hospital of Guangzhou Medical University (Guangzhou Huiai Hospital), Guangzhou, Guangdong, People's Republic of China
| | - Fengchun Wu
- The Affiliated Brain Hospital of Guangzhou Medical University (Guangzhou Huiai Hospital), Guangzhou, Guangdong, People's Republic of China
| | - Sumiao Zhou
- The Affiliated Brain Hospital of Guangzhou Medical University (Guangzhou Huiai Hospital), Guangzhou, Guangdong, People's Republic of China
| | - Shuhua Deng
- The Affiliated Brain Hospital of Guangzhou Medical University (Guangzhou Huiai Hospital), Guangzhou, Guangdong, People's Republic of China
| | - Yuping Ning
- First School of Clinical Medicine, Southern Medical University, Guangzhou, Guangdong, People's Republic of China.,The Affiliated Brain Hospital of Guangzhou Medical University (Guangzhou Huiai Hospital), Guangzhou, Guangdong, People's Republic of China.,Guangdong Engineering Technology Research Center for Translational Medicine of Mental Disorders, Guangzhou, Guangdong, People's Republic of China
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Boros FA, Vécsei L. Immunomodulatory Effects of Genetic Alterations Affecting the Kynurenine Pathway. Front Immunol 2019; 10:2570. [PMID: 31781097 PMCID: PMC6851023 DOI: 10.3389/fimmu.2019.02570] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Accepted: 10/16/2019] [Indexed: 12/15/2022] Open
Abstract
Several enzymes and metabolites of the kynurenine pathway (KP) have immunomodulatory effects. Modulation of the activities and levels of these molecules might be of particular importance under disease conditions when the amelioration of overreacting immune responses is desired. Results obtained by the use of animal and tissue culture models indicate that by eliminating or decreasing activities of key enzymes of the KP, a beneficial shift in disease outcome can be attained. This review summarizes experimental data of models in which IDO, TDO, or KMO activity modulation was achieved by interventions affecting enzyme production at a genomic level. Elimination of IDO activity was found to improve the outcome of sepsis, certain viral infections, chronic inflammation linked to diabetes, obesity, aorta aneurysm formation, and in anti-tumoral processes. Similarly, lack of TDO activity was advantageous in the case of anti-tumoral immunity, while KMO inhibition was found to be beneficial against microorganisms and in the combat against tumors, as well. On the other hand, the complex interplay among KP metabolites and immune function in some cases requires an increase in a particular enzyme activity for the desired immune response modulation, as was shown by the exacerbation of liver fibrosis due to the elimination of IDO activity and the detrimental effects of TDO inhibition in a mouse model of autoimmune gastritis. The relevance of these studies concerning possible human applications are discussed and highlighted. Finally, a brief overview is presented on naturally occurring genetic variants affecting immune functions via modulation of KP enzyme activity.
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Affiliation(s)
- Fanni A Boros
- Department of Neurology, Faculty of Medicine, Albert Szent-Györgyi Clinical Center, University of Szeged, Szeged, Hungary
| | - László Vécsei
- Department of Neurology, Faculty of Medicine, Albert Szent-Györgyi Clinical Center, University of Szeged, Szeged, Hungary.,MTA-SZTE Neuroscience Research Group of the Hungarian Academy of Sciences, University of Szeged, Szeged, Hungary.,Department of Neurology, Interdisciplinary Excellence Centre, University of Szeged, Szeged, Hungary
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Nakazawa K, Sapkota K. The origin of NMDA receptor hypofunction in schizophrenia. Pharmacol Ther 2019; 205:107426. [PMID: 31629007 DOI: 10.1016/j.pharmthera.2019.107426] [Citation(s) in RCA: 124] [Impact Index Per Article: 24.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Accepted: 10/10/2019] [Indexed: 12/12/2022]
Abstract
N-methyl-d-aspartate (NMDA) receptor (NMDAR) hypofunction plays a key role in pathophysiology of schizophrenia. Since NMDAR hypofunction has also been reported in autism, Alzheimer's disease and cognitive dementia, it is crucial to identify the location, timing, and mechanism of NMDAR hypofunction for schizophrenia for better understanding of disease etiology and for novel therapeutic intervention. In this review, we first discuss the shared underlying mechanisms of NMDAR hypofunction in NMDAR antagonist models and the anti-NMDAR autoantibody model of schizophrenia and suggest that NMDAR hypofunction could occur in GABAergic neurons in both models. Preclinical models using transgenic mice have shown that NMDAR hypofunction in cortical GABAergic neurons, in particular parvalbumin-positive fast-spiking interneurons, in the early postnatal period confers schizophrenia-related phenotypes. Recent studies suggest that NMDAR hypofunction can also occur in PV-positive GABAergic neurons with alterations of NMDAR-associated proteins, such as neuregulin/ErbB4, α7nAChR, and serine racemase. Furthermore, several environmental factors, such as oxidative stress, kynurenic acid and hypoxia, may also potentially elicit NMDAR hypofunction in GABAergic neurons in early postnatal period. Altogether, the studies discussed here support a central role for GABAergic abnormalities in the context of NMDAR hypofunction. We conclude by suggesting potential therapeutic strategies to improve the function of fast-spiking neurons.
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Zádori D, Veres G, Szalárdy L, Klivényi P, Vécsei L. Alzheimer's Disease: Recent Concepts on the Relation of Mitochondrial Disturbances, Excitotoxicity, Neuroinflammation, and Kynurenines. J Alzheimers Dis 2019; 62:523-547. [PMID: 29480191 DOI: 10.3233/jad-170929] [Citation(s) in RCA: 73] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The pathomechanism of Alzheimer's disease (AD) certainly involves mitochondrial disturbances, glutamate excitotoxicity, and neuroinflammation. The three main aspects of mitochondrial dysfunction in AD, i.e., the defects in dynamics, altered bioenergetics, and the deficient transport, act synergistically. In addition, glutamatergic neurotransmission is affected in several ways. The balance between synaptic and extrasynaptic glutamatergic transmission is shifted toward the extrasynaptic site contributing to glutamate excitotoxicity, a phenomenon augmented by increased glutamate release and decreased glutamate uptake. Neuroinflammation in AD is predominantly linked to central players of the innate immune system, with central nervous system (CNS)-resident microglia, astroglia, and perivascular macrophages having been implicated at the cellular level. Several abnormalities have been described regarding the activation of certain steps of the kynurenine (KYN) pathway of tryptophan metabolism in AD. First of all, the activation of indolamine 2,3-dioxygenase, the first and rate-limiting step of the pathway, is well-demonstrated. 3-Hydroxy-L-KYN and its metabolite, 3-hydroxy-anthranilic acid have pro-oxidant, antioxidant, and potent immunomodulatory features, giving relevance to their alterations in AD. Another metabolite, quinolinic acid, has been demonstrated to be neurotoxic, promoting glutamate excitotoxicity, reactive oxygen species production, lipid peroxidation, and microglial neuroinflammation, and its abundant presence in AD pathologies has been demonstrated. Finally, the neuroprotective metabolite, kynurenic acid, has been associated with antagonistic effects at glutamate receptors, free radical scavenging, and immunomodulation, giving rise to potential therapeutic implications. This review presents the multiple connections of KYN pathway-related alterations to three main domains of AD pathomechanism, such as mitochondrial dysfunction, excitotoxicity, and neuroinflammation, implicating possible therapeutic options.
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Affiliation(s)
- Dénes Zádori
- Department of Neurology, Faculty of Medicine, Albert Szent-Györgyi Clinical Center, University of Szeged, Szeged, Hungary
| | - Gábor Veres
- Department of Neurology, Faculty of Medicine, Albert Szent-Györgyi Clinical Center, University of Szeged, Szeged, Hungary
| | - Levente Szalárdy
- Department of Neurology, Faculty of Medicine, Albert Szent-Györgyi Clinical Center, University of Szeged, Szeged, Hungary
| | - Péter Klivényi
- Department of Neurology, Faculty of Medicine, Albert Szent-Györgyi Clinical Center, University of Szeged, Szeged, Hungary
| | - László Vécsei
- Department of Neurology, Faculty of Medicine, Albert Szent-Györgyi Clinical Center, University of Szeged, Szeged, Hungary.,MTA-SZTE Neuroscience Research Group, Szeged, Hungary
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Sekine A, Fukuwatari T. Acute liver failure increases kynurenic acid production in rat brain via changes in tryptophan metabolism in the periphery. Neurosci Lett 2019; 701:14-19. [PMID: 30738081 DOI: 10.1016/j.neulet.2019.02.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Revised: 02/03/2019] [Accepted: 02/04/2019] [Indexed: 12/20/2022]
Abstract
The tryptophan metabolite, kynurenic acid (KYNA), is a preferential antagonist of the α7 nicotinic acetylcholine receptor and N-methyl-d-aspartic acid receptor at endogenous brain concentrations. Recent studies have suggested that increased brain KYNA levels are involved in psychiatric disorders such as schizophrenia and depression. Most of the brain kynurenine (KYN), the KYNA precursor, comes from the periphery, and the liver has a central role in the peripheral tryptophan metabolism. In this study, the effect of acute liver failure (ALF) on brain KYNA production and on the peripheral tryptophan metabolism was investigated in rats. ALF was induced by administration of the hepatotoxin, thioacetamide (TAA). Brain KYNA levels were increased by TAA-induced ALF, and these increases were consistent with KYN levels in the brain, serum and liver. These results suggest that the ALF-induced increase in serum KYN contributes to the increase in brain KYNA via elevated KYN uptake within the brain. This increase in serum KYN level can be caused by the changes in tryptophan-2,3-dioxygenase activity in the liver and the immune-related activation of indoleamine-2,3-dioxygenase in extrahepatic tissues. These findings suggest that hepatic dysfunction may contribute to neurological and psychiatric diseases associated with increased KYNA levels.
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Affiliation(s)
- Airi Sekine
- Department of Nutrition, School of Human Cultures, The University of Shiga Prefecture, 2500 Hassaka, Hikone, Shiga, 522-8533, Japan
| | - Tsutomu Fukuwatari
- Department of Nutrition, School of Human Cultures, The University of Shiga Prefecture, 2500 Hassaka, Hikone, Shiga, 522-8533, Japan.
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Linking phencyclidine intoxication to the tryptophan-kynurenine pathway: Therapeutic implications for schizophrenia. Neurochem Int 2019; 125:1-6. [PMID: 30731185 DOI: 10.1016/j.neuint.2019.02.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Revised: 01/17/2019] [Accepted: 02/04/2019] [Indexed: 12/17/2022]
Abstract
Phencyclidine (PCP) is a dissociative anesthetic that induces psychotic symptoms and neurocognitive deficits in rodents similar to those observed in schizophrenia patients. PCP administration in healthy human subjects induces schizophrenia-like symptoms such as positive and negative symptoms, and a range of cognitive deficits. It has been reported that PCP, ketamine, and related drugs such as N-methyl-D-aspartate-type (NMDA) glutamate receptor antagonists, induce behavioral effects by blocking neurotransmission at NMDA receptors. Further, NMDA receptor antagonists reproduce specific aspects of the symptoms of schizophrenia. Neurochemical models based on the actions of PCP are well established, with increased focus on glutamatergic dysfunction as a basis for both symptoms and cognitive dysfunction in schizophrenia. On the other hand, the endogenous NMDA receptor antagonist, kynurenic acid (KYNA), which is a product of tryptophan-kynurenine pathway (KP) metabolism, is involved in schizophrenia pathogenesis. KYNA concentrations are elevated in the prefrontal cortex and cerebrospinal fluid of patients with schizophrenia. KYNA elevation affects neurotransmitter release in a similar manner to that of psychotomimetic agents such as PCP, underscoring a molecular basis of its involvement in schizophrenia pathophysiology. This review will highlight the relationship between PCP and KP metabolites based on evidence that both exogenous and endogenous NMDA receptor antagonists are involved in the pathogenesis of schizophrenia, and discuss our current understanding of the mechanisms underlying dysfunctional glutamatergic signaling as potential therapeutic targets for schizophrenia.
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Peripheral and central levels of kynurenic acid in bipolar disorder subjects and healthy controls. Transl Psychiatry 2019; 9:37. [PMID: 30696814 PMCID: PMC6351610 DOI: 10.1038/s41398-019-0378-9] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Revised: 11/26/2018] [Accepted: 01/01/2019] [Indexed: 02/08/2023] Open
Abstract
Metabolites of the kynurenine pathway of tryptophan degradation, in particular, the N-Methyl-D-aspartic acid receptor antagonist kynurenic acid (KYNA), are increasingly recognized as primary pathophysiological promoters in several psychiatric diseases. Studies analyzing central KYNA levels from subjects with psychotic disorders have reported increased levels. However, sample sizes are limited and in contrast many larger studies examining this compound in blood from psychotic patients commonly report a decrease. A major question is to what extent peripheral KYNA levels reflect brain KYNA levels under physiological as well as pathophysiological conditions. Here we measured KYNA in plasma from a total of 277 subjects with detailed phenotypic data, including 163 BD subjects and 114 matched healthy controls (HCs), using an HPLC system. Among them, 94 BD subjects and 113 HCs also had CSF KYNA concentrations analyzed. We observe a selective increase of CSF KYNA in BD subjects with previous psychotic episodes although this group did not display altered plasma KYNA levels. In contrast, BD subjects with ongoing depressive symptoms displayed a tendency to decreased plasma KYNA concentrations but unchanged CSF KYNA levels. Sex and age displayed specific effects on KYNA concentrations depending on if measured centrally or in the periphery. These findings implicate brain-specific regulation of KYNA under physiological as well as under pathophysiological conditions and strengthen our previous observation of CSF KYNA as a biomarker in BD. In summary, biomarker and drug discovery studies should include central KYNA measurements for a more reliable estimation of brain KYNA levels.
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Beggiato S, Notarangelo FM, Sathyasaikumar KV, Giorgini F, Schwarcz R. Maternal genotype determines kynurenic acid levels in the fetal brain: Implications for the pathophysiology of schizophrenia. J Psychopharmacol 2018; 32:1223-1232. [PMID: 30354938 DOI: 10.1177/0269881118805492] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
BACKGROUND Several studies suggest a pathophysiologically relevant association between increased brain levels of the neuroinhibitory tryptophan metabolite kynurenic acid and cognitive dysfunctions in people with schizophrenia. Elevated kynurenic acid in schizophrenia may be secondary to a genetic alteration of kynurenine 3-monooxygenase, a pivotal enzyme in the kynurenine pathway of tryptophan degradation. In rats, prenatal exposure to kynurenine, the direct bioprecursor of kynurenic acid, induces cognitive impairments reminiscent of schizophrenia in adulthood, suggesting a developmental dimension to the link between kynurenic acid and schizophrenia. AIM The purpose of this study was to explore the possible impact of the maternal genotype on kynurenine pathway metabolism. METHODS We exposed pregnant wild-type ( Kmo+/+ ) and heterozygous ( Kmo+/-) mice to kynurenine (10 mg/day) during the last week of gestation and determined the levels of kynurenic acid and two other neuroactive kynurenine pathway metabolites, 3-hydroxykynurenine and quinolinic acid, in fetal brain and placenta on embryonic day 17/18. RESULTS Maternal kynurenine treatment raised kynurenic acid levels significantly more in the brain of heterozygous offspring of Kmo+/- than in the brain of Kmo+/+ offspring. Conversely, 3-hydroxykynurenine and quinolinic acid levels in the fetal brain tended to be lower in heterozygous animals derived from kynurenine-treated Kmo+/- mice than in corresponding Kmo+/+ offspring. Genotype-related effects on the placenta were qualitatively similar but less pronounced. Kynurenine treatment also caused a preferential elevation in cerebral kynurenic acid levels in Kmo+/- compared to Kmo+/+ dams. CONCLUSIONS The disproportionate kynurenic acid increase in the brain of Kmo+/- animals indicates that the maternal Kmo genotype may play a key role in the pathophysiology of schizophrenia.
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Affiliation(s)
- Sarah Beggiato
- 1 Department of Life Sciences and Biotechnologies, University of Ferrara, Ferrara, Italy.,2 Laboratory for the Technology of Advanced Therapies (LTTA Centre), University of Ferrara, Ferrara, Italy
| | - Francesca M Notarangelo
- 3 Maryland Psychiatric Research Center, University of Maryland School of Medicine, Baltimore, MD, USA
| | | | - Flaviano Giorgini
- 4 Department of Genetics and Genome Biology, University of Leicester, Leicester, UK
| | - Robert Schwarcz
- 3 Maryland Psychiatric Research Center, University of Maryland School of Medicine, Baltimore, MD, USA
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Tufvesson-Alm M, Schwieler L, Schwarcz R, Goiny M, Erhardt S, Engberg G. Importance of kynurenine 3-monooxygenase for spontaneous firing and pharmacological responses of midbrain dopamine neurons: Relevance for schizophrenia. Neuropharmacology 2018; 138:130-139. [PMID: 29879409 DOI: 10.1016/j.neuropharm.2018.06.003] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Revised: 06/01/2018] [Accepted: 06/03/2018] [Indexed: 12/15/2022]
Abstract
Kynurenine 3-monooxygenase (KMO) is an essential enzyme of the kynurenine pathway, converting kynurenine into 3-hydroxykynurenine. Inhibition of KMO increases kynurenine, resulting in elevated levels of kynurenic acid (KYNA), an endogenous N-methyl-d-aspartate and α*7-nicotinic receptor antagonist. The concentration of KYNA is elevated in the brain of patients with schizophrenia, possibly as a result of a reduced KMO activity. In the present study, using in vivo single cell recording techniques, we investigated the electrophysiological characteristics of ventral tegmental area dopamine (VTA DA) neurons and their response to antipsychotic drugs in a KMO knock-out (K/O) mouse model. KMO K/O mice exhibited a marked increase in spontaneous VTA DA neuron activity as compared to wild-type (WT) mice. Furthermore, VTA DA neurons showed clear-cut, yet qualitatively opposite, responses to the antipsychotic drugs haloperidol and clozapine in the two genotypes. The anti-inflammatory drug parecoxib successfully lowered the firing activity of VTA DA neurons in KMO K/O, but not in WT mice. Minocycline, an antibiotic and anti-inflammatory drug, produced no effect in this regard. Taken together, the present data further support the usefulness of KMO K/O mice for studying distinct aspects of the pathophysiology and pharmacological treatment of psychiatric disorders such as schizophrenia.
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Affiliation(s)
| | - Lilly Schwieler
- Department of Physiology and Pharmacology, Karolinska Institute, Stockholm, Sweden
| | - Robert Schwarcz
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Michel Goiny
- Department of Physiology and Pharmacology, Karolinska Institute, Stockholm, Sweden
| | - Sophie Erhardt
- Department of Physiology and Pharmacology, Karolinska Institute, Stockholm, Sweden
| | - Göran Engberg
- Department of Physiology and Pharmacology, Karolinska Institute, Stockholm, Sweden; Department of Physiology and Pharmacology, Karolinska Institute, Biomedicum 5C, 171 77, Stockholm, Sweden.
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Hahn B, Reneski CH, Pocivavsek A, Schwarcz R. Prenatal kynurenine treatment in rats causes schizophrenia-like broad monitoring deficits in adulthood. Psychopharmacology (Berl) 2018; 235:651-661. [PMID: 29128872 PMCID: PMC5823752 DOI: 10.1007/s00213-017-4780-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Accepted: 11/01/2017] [Indexed: 12/12/2022]
Abstract
RATIONALE Elevated brain kynurenic acid (KYNA) levels are implicated in the pathology and neurodevelopmental pathogenesis of schizophrenia. In rats, embryonic treatment with kynurenine (EKyn) causes elevated brain KYNA levels in adulthood and cognitive deficits reminiscent of schizophrenia. OBJECTIVES Growing evidence suggests that people with schizophrenia have a narrowed attentional focus, and we aimed at establishing whether these abnormalities may be related to KYNA dysregulation. METHODS To test whether EKyn rats display broad monitoring deficits, kynurenine was added to the chow of pregnant Wistar dams on embryonic days 15-22. As adults, 20 EKyn and 20 control rats were trained to stable performance on the five-choice serial reaction time task, requiring the localization of 1-s light stimuli presented randomly across five apertures horizontally arranged along a curved wall, equating the locomotor demands of reaching each hole. RESULTS EKyn rats displayed elevated omission errors and reduced anticipatory responses relative to control rats, indicative of a lower response rate, and showed reduced locomotor activity. The ability to spread attention broadly was measured by parsing performance by stimulus location. Both groups displayed poorer stimulus detection with greater target location eccentricity, but this effect was significantly more pronounced in the EKyn group. Specifically, the groups differed in the spatial distribution of correct but not incorrect responses. This pattern cannot be explained by differences in response rate and is indicative of a narrowed attentional focus. CONCLUSIONS The findings suggest a potential etiology of broad monitoring deficits in schizophrenia, which may constitute a core cognitive deficit.
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Affiliation(s)
- Britta Hahn
- Maryland Psychiatric Research Center, University of Maryland School of Medicine, P.O. Box 21247, Baltimore, MD, 21228, USA.
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Dostal CR, Carson Sulzer M, Kelley KW, Freund GG, M cCusker RH. Glial and tissue-specific regulation of Kynurenine Pathway dioxygenases by acute stress of mice. Neurobiol Stress 2017; 7:1-15. [PMID: 29520368 PMCID: PMC5840960 DOI: 10.1016/j.ynstr.2017.02.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Revised: 01/10/2017] [Accepted: 02/07/2017] [Indexed: 01/11/2023] Open
Abstract
Stressors activate the hypothalamic-pituitary-adrenal (HPA) axis and immune system eliciting changes in cognitive function, mood and anxiety. An important link between stress and altered behavior is stimulation of the Kynurenine Pathway which generates neuroactive and immunomodulatory kynurenines. Tryptophan entry into this pathway is controlled by rate-limiting indoleamine/tryptophan 2,3-dioxygenases (DOs: Ido1, Ido2, Tdo2). Although implicated as mediating changes in behavior, detecting stress-induced DO expression has proven inconsistent. Thus, C57BL/6J mice were used to characterize DO expression in brain-regions, astrocytes and microglia to characterize restraint-stress-induced DO expression. Stress increased kynurenine in brain and plasma, demonstrating increased DO activity. Of three Ido1 transcripts, only Ido1-v1 expression was increased by stress and within astrocytes, not microglia, indicating transcript- and glial-specificity. Stress increased Ido1-v1 only in frontal cortex and hypothalamus, indicating brain-region specificity. Of eight Ido2 transcripts, Ido2-v3 expression was increased by stress, again only within astrocytes. Likewise, stress increased Tdo2-FL expression in astrocytes, not microglia. Interestingly, Ido2 and Tdo2 transcripts were not correspondingly induced in Ido1-knockout (Ido1KO) mice, suggesting that Ido1 is necessary for the central DO response to acute stress. Unlike acute inflammatory models resulting in DO induction within microglia, only astrocyte DO expression was increased by acute restraint-stress, defining their unique role during stress-dependent activation of the Kynurenine Pathway.
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Affiliation(s)
- Carlos R. Dostal
- Neuroscience Program, 250 Edward R Madigan Laboratory, 1201 W. Gregory Drive, Urbana, IL 61801, USA
- Medical Scholars Program, 250 Edward R Madigan Laboratory, 1201 W. Gregory Drive, Urbana, IL 61801, USA
| | - Megan Carson Sulzer
- School of Molecular and Cellular Biology, 250 Edward R Madigan Laboratory, 1201 W. Gregory Drive, Urbana, IL 61801, USA
| | - Keith W. Kelley
- Neuroscience Program, 250 Edward R Madigan Laboratory, 1201 W. Gregory Drive, Urbana, IL 61801, USA
- Department of Animal Sciences, 250 Edward R Madigan Laboratory, 1201 W. Gregory Drive, Urbana, IL 61801, USA
- Department of Pathology, University of Illinois at Urbana-Champaign, 250 Edward R Madigan Laboratory, 1201 W. Gregory Drive, Urbana, IL 61801, USA
| | - Gregory G. Freund
- Neuroscience Program, 250 Edward R Madigan Laboratory, 1201 W. Gregory Drive, Urbana, IL 61801, USA
- Department of Animal Sciences, 250 Edward R Madigan Laboratory, 1201 W. Gregory Drive, Urbana, IL 61801, USA
- Department of Pathology, University of Illinois at Urbana-Champaign, 250 Edward R Madigan Laboratory, 1201 W. Gregory Drive, Urbana, IL 61801, USA
| | - Robert H. McCusker
- Neuroscience Program, 250 Edward R Madigan Laboratory, 1201 W. Gregory Drive, Urbana, IL 61801, USA
- Department of Animal Sciences, 250 Edward R Madigan Laboratory, 1201 W. Gregory Drive, Urbana, IL 61801, USA
- Department of Pathology, University of Illinois at Urbana-Champaign, 250 Edward R Madigan Laboratory, 1201 W. Gregory Drive, Urbana, IL 61801, USA
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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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Oliveros A, Wininger K, Sens J, Larsson MK, Liu XC, Choi S, Faka A, Schwieler L, Engberg G, Erhardt S, Choi DS. LPS-induced cortical kynurenic acid and neurogranin-NFAT signaling is associated with deficits in stimulus processing during Pavlovian conditioning. J Neuroimmunol 2017; 313:1-9. [PMID: 29153599 DOI: 10.1016/j.jneuroim.2017.09.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Revised: 05/04/2017] [Accepted: 09/27/2017] [Indexed: 12/13/2022]
Abstract
The N-Methyl-d-Aspartate receptor (NMDAR) antagonist kynurenic acid (KYNA) and the post-synaptic calmodulin binding protein neurogranin (Nrgn) have been implicated in neurological and neuropsychiatric conditions including Alzheimer's disease and schizophrenia. This study indicates that systemic dual-lipopolysaccharide (LPS) injections increases KYNA in the medial prefrontal cortex (mPFC), which is accompanied with increased phosphorylation of nuclear factor kappa chain of activated B cells (NFκB) and activation of the nuclear factor of activated T- cells (NFAT). Our results also indicate that dual-LPS increases Nrgn phosphorylation and concomitantly reduces phosphorylation of calmodulin kinase-II (CaMKII). We confirmed that systemic blockade of kynurenine-3 monooxygenase in conjunction with kynurenine administration results in significant increases in Nrgn phosphorylation and a significant reduction of CaMKII phosphorylation in the mPFC. Consequently, dual-LPS administration induced significant impairments in stimulus processing during Pavlovian conditioning. Taken together, our study indicates that elevations in KYNA in the mPFC can directly regulate NMDA-Nrgn-CaMKII signaling, suggesting that neuroinflammatory conditions affecting this pathway may be associated with cognitive dysfunction.
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Affiliation(s)
- A Oliveros
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic College of Medicine, Rochester, MN 55905, USA
| | - K Wininger
- Neurobiology of Disease Program, Mayo Clinic College of Medicine, Rochester, MN 55905, USA
| | - J Sens
- Neurobiology of Disease Program, Mayo Clinic College of Medicine, Rochester, MN 55905, USA
| | - M K Larsson
- Department of Physiology and Pharmacology, Karolinska Institute, Stockholm, Sweden
| | - X C Liu
- Department of Physiology and Pharmacology, Karolinska Institute, Stockholm, Sweden
| | - S Choi
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic College of Medicine, Rochester, MN 55905, USA
| | - A Faka
- Department of Physiology and Pharmacology, Karolinska Institute, Stockholm, Sweden
| | - L Schwieler
- Department of Physiology and Pharmacology, Karolinska Institute, Stockholm, Sweden
| | - G Engberg
- Department of Physiology and Pharmacology, Karolinska Institute, Stockholm, Sweden
| | - S Erhardt
- Department of Physiology and Pharmacology, Karolinska Institute, Stockholm, Sweden
| | - D S Choi
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic College of Medicine, Rochester, MN 55905, USA; Department of Psychiatry and Psychology, Mayo Clinic College of Medicine, Rochester, MN 55905, USA; Neurobiology of Disease Program, Mayo Clinic College of Medicine, Rochester, MN 55905, USA.
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Jacobs KR, Castellano-Gonzalez G, Guillemin GJ, Lovejoy DB. Major Developments in the Design of Inhibitors along the Kynurenine Pathway. Curr Med Chem 2017; 24:2471-2495. [PMID: 28464785 PMCID: PMC5748880 DOI: 10.2174/0929867324666170502123114] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Revised: 03/13/2017] [Accepted: 04/18/2017] [Indexed: 12/20/2022]
Abstract
Disrupted kynurenine pathway (KP) metabolism has been implicated in the progression of neurodegenerative disease, psychiatric disorders and cancer. Modulation of enzyme activity along this pathway may therefore offer potential new therapeutic strategies for these conditions. Considering their prominent positions in the KP, the enzymes indoleamine 2,3-dioxygenase, kynurenine 3-monooxygenase and kynurenine aminotransferase, appear the most attractive targets. Already, increasing interest in this pathway has led to the identification of a number of potent and selective enzyme inhibitors with promising pre-clinical data and the elucidation of several enzyme crystal structures provides scope to rationalize the molecular mechanisms of inhibitor activity. The field seems poised to yield one or more inhibitors that should find clinical utility.
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Affiliation(s)
- Kelly R Jacobs
- Neuroinflammation Group, Department of Biomedical Research, Faculty of Medicine and Health Sciences, Macquarie University, Sydney. Australia
| | - Gloria Castellano-Gonzalez
- Neuroinflammation Group, Department of Biomedical Research, Faculty of Medicine and Health Sciences, Macquarie University, Sydney. Australia
| | - Gilles J Guillemin
- Department of Biomedical Research, Faculty of Medicine and Health Science, Macquarie University, 2 Technology Place, Sydney. Australia
| | - David B Lovejoy
- Department of Biomedical Research, Faculty of Medicine and Health Science, Macquarie University, 2 Technology Place, Sydney. Australia
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Barron H, Hafizi S, Mizrahi R. Towards an Integrated View of Early Molecular Changes Underlying Vulnerability to Social Stress in Psychosis. MODERN TRENDS IN PHARMACOPSYCHIATRY 2017; 31:96-106. [PMID: 28738349 DOI: 10.1159/000470810] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Psychotic disorders are heterogeneous and complex, involving many putative causal factors interacting along the course of disease development. Many of the factors implicated in the pathogenesis of psychosis also appear to be involved in disease onset and subsequent neuroprogression. Herein, we highlight the pertinent literature implicating inflammation and oxidative stress in the pathogenesis of psychosis, and the potential contribution of N-methyl-D-aspartate receptors (NMDARs). We also emphasize the role of peripubertal social stress in psychosis, and the ways in which hippocampal dysfunction can mediate dysregulation of the hypothalamic-pituitary-adrenal axis and cortisol release. Finally, we propose a model wherein inflammation and oxidative stress act as a first hit, producing altered parvalbumin interneuron development, NMDAR hypofunction, microglial priming, and sensitivity to a second hit of peripubertal social stress. With a greater understanding of how these factors interact, it may be possible to detect, prevent, and treat psychosis more effectively.
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Plitman E, Iwata Y, Caravaggio F, Nakajima S, Chung JK, Gerretsen P, Kim J, Takeuchi H, Chakravarty MM, Remington G, Graff-Guerrero A. Kynurenic Acid in Schizophrenia: A Systematic Review and Meta-analysis. Schizophr Bull 2017; 43:764-777. [PMID: 28187219 PMCID: PMC5472151 DOI: 10.1093/schbul/sbw221] [Citation(s) in RCA: 132] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Kynurenic acid (KYNA) is an endogenous antagonist of N-methyl-D-aspartate and α7 nicotinic acetylcholine receptors that is derived from astrocytes as part of the kynurenine pathway of tryptophan degradation. Evidence suggests that abnormal KYNA levels are involved in the pathophysiology of schizophrenia. However, this has never been assessed through a meta-analysis. A literature search was conducted through Ovid using Embase, Medline, and PsycINFO databases (last search: December 2016) with the search terms: (kynuren* or KYNA) and (schizophreni* or psychosis). English language studies measuring KYNA levels using any method in patients with schizophrenia and healthy controls (HCs) were identified. Standardized mean differences (SMDs) were calculated to determine differences in KYNA levels between groups. Subgroup analyses were separately performed for nonoverlapping participant samples, KYNA measurement techniques, and KYNA sample source. The influences of patients' age, antipsychotic status (%medicated), and sex (%male) on study SMDs were assessed through a meta-regression. Thirteen studies were deemed eligible for inclusion in the meta-analysis. In the main analysis, KYNA levels were elevated in the patient group. Subgroup analyses demonstrated that KYNA levels were increased in nonoverlapping participant samples, and centrally (cerebrospinal fluid and brain tissue) but not peripherally. Patients' age, %medicated, and %male were each positively associated with study SMDs. Overall, KYNA levels are increased in patients with schizophrenia, specifically within the central nervous system. An improved understanding of KYNA in patients with schizophrenia may contribute to the development of novel diagnostic approaches and therapeutic strategies.
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Affiliation(s)
- Eric Plitman
- Multimodal Imaging Group, Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, ON, Canada;,Institute of Medical Science, University of Toronto, Toronto, ON, Canada
| | - Yusuke Iwata
- Multimodal Imaging Group, Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, ON, Canada
| | - Fernando Caravaggio
- Multimodal Imaging Group, Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, ON, Canada
| | - Shinichiro Nakajima
- Multimodal Imaging Group, Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, ON, Canada;,Department of Psychiatry, University of Toronto, Toronto, ON, Canada;,Geriatric Mental Health Division, Centre for Addiction and Mental Health, Toronto, ON, Canada;,Department of Neuropsychiatry, Keio University, Tokyo, Japan
| | - Jun Ku Chung
- Multimodal Imaging Group, Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, ON, Canada;,Institute of Medical Science, University of Toronto, Toronto, ON, Canada
| | - Philip Gerretsen
- Multimodal Imaging Group, Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, ON, Canada;,Department of Psychiatry, University of Toronto, Toronto, ON, Canada;,Geriatric Mental Health Division, Centre for Addiction and Mental Health, Toronto, ON, Canada
| | - Julia Kim
- Multimodal Imaging Group, Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, ON, Canada;,Institute of Medical Science, University of Toronto, Toronto, ON, Canada
| | - Hiroyoshi Takeuchi
- Department of Psychiatry, University of Toronto, Toronto, ON, Canada;,Department of Neuropsychiatry, Keio University, Tokyo, Japan;,Schizophrenia Division, Centre for Addiction and Mental Health, Toronto, ON, Canada
| | - M. Mallar Chakravarty
- Cerebral Imaging Centre, Douglas Mental Health University Institute, McGill University, Montreal, QC, Canada;,Departments of Psychiatry and Biomedical Engineering, McGill University, Montreal, QC, Canada
| | - Gary Remington
- Institute of Medical Science, University of Toronto, Toronto, ON, Canada;,Department of Psychiatry, University of Toronto, Toronto, ON, Canada;,Schizophrenia Division, Centre for Addiction and Mental Health, Toronto, ON, Canada;,Campbell Institute Research Program, Centre for Addiction and Mental Health, Toronto, ON, Canada
| | - Ariel Graff-Guerrero
- Multimodal Imaging Group, Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, ON, Canada;,Institute of Medical Science, University of Toronto, Toronto, ON, Canada;,Department of Psychiatry, University of Toronto, Toronto, ON, Canada;,Geriatric Mental Health Division, Centre for Addiction and Mental Health, Toronto, ON, Canada;,Campbell Institute Research Program, Centre for Addiction and Mental Health, Toronto, ON, Canada
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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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Correlations of Kynurenic Acid, 3-Hydroxykynurenine, sIL-2R, IFN-α, and IL-4 with Clinical Symptoms During Acute Relapse of Schizophrenia. Neurotox Res 2017; 32:17-26. [DOI: 10.1007/s12640-017-9714-0] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Revised: 02/09/2017] [Accepted: 02/24/2017] [Indexed: 12/13/2022]
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