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Uzun Uysal E, Tomruk NB, Çakır Şen C, Yıldızhan E. D-serine and D-amino acid oxidase levels in patients with schizophrenia spectrum disorders in the first episode and 6-month follow-up. J Psychiatr Res 2024; 175:123-130. [PMID: 38728915 DOI: 10.1016/j.jpsychires.2024.05.004] [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: 03/03/2024] [Revised: 04/28/2024] [Accepted: 05/02/2024] [Indexed: 05/12/2024]
Abstract
BACKGROUND D-serine and the D-amino acid oxidase (DAO) enzyme, which breaks down d-amino acids, may be involved in the pathophysiology of schizophrenia by affecting the N-methyl-D-aspartate (NMDA) receptor. The exact role of D-serine and DAO, as well as the consequences of increased DAO activity in patients with schizophrenia, remain unclear. We aimed to investigate D-serine and DAO levels in patients with first-episode schizophrenia spectrum disorders before treatment and after six months of treatment. METHOD Comparisons for the serum levels of D-serine and DAO were made between 81 healthy controls and 89 patients with first-episode schizophrenia spectrum disorders without a history of treatment. Further comparisons were made after 6 months for changes in these levels in the 41 patients in follow-up. The Positive and Negative Syndrome Scale (PANNS), Calgary Scale for Depression in Schizophrenia (CDSS), Montreal Cognitive Assessment Scale (MoCA), Global Assessment Scale (GAS), and Clinical Global Impression Scale (CGI) were used to evaluate the symptom severity and functionality. Secondary results included comparisons related to antipsychotic equivalent doses. RESULTS Before treatment, patients had significantly lower levels of D-serine, DAO, and D-serine/DAO ratio compared to healthy individuals (p < 0.001; p < 0.001; p = 0.004). DAO and D-serine levels of the patients were higher after six months of treatment (p = 0.025; p = 0.001). There was correlation of DAO levels with antipsychotic dosage and with PANSS negative and total subscale scores (rho = 0.421, p = 0.01; rho = 0.280, p = 0.008; rho = 0.371, p = 0.000). No correlation was found between serum D-serine level, DAO level, and the D-serine/DAO ratio with cognitive function. CONCLUSIONS The results suggest that D-serine and DAO may play a role that is sensitive to treatment effects in schizophrenia spectrum disorders. To gain a more comprehensive understanding of the impact antipsychotic drugs have on NMDA receptor dysfunction, there is a requirement for studies that directly evaluates the activity of the DAO enzyme.
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Affiliation(s)
- Eda Uzun Uysal
- Arnavutkoy State Hospital, Department of Psychiatry, Istanbul, Turkey.
| | - Nesrin Buket Tomruk
- Bakırköy Research and Training Hospital for Psychiatry, Neurology and Neurosurgery, Department of Psychiatry, Istanbul, Turkey
| | - Cansu Çakır Şen
- Bakırköy Research and Training Hospital for Psychiatry, Neurology and Neurosurgery, Department of Psychiatry, Istanbul, Turkey
| | - Eren Yıldızhan
- Bakırköy Research and Training Hospital for Psychiatry, Neurology and Neurosurgery, Department of Psychiatry, Istanbul, Turkey
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2
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Yap SH, Lee CS, Zulkifli ND, Suresh D, Hamase K, Das KT, Rajasuriar R, Leong KH. D-Amino acids differentially trigger an inflammatory environment in vitro. Amino Acids 2024; 56:6. [PMID: 38310167 PMCID: PMC10838247 DOI: 10.1007/s00726-023-03360-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Accepted: 12/20/2023] [Indexed: 02/05/2024]
Abstract
Studies in vivo have demonstrated that the accumulation of D-amino acids (D-AAs) is associated with age-related diseases and increased immune activation. However, the underlying mechanism(s) of these observations are not well defined. The metabolism of D-AAs by D-amino oxidase (DAO) produces hydrogen peroxide (H2O2), a reactive oxygen species involved in several physiological processes including immune response, cell differentiation, and proliferation. Excessive levels of H2O2 contribute to oxidative stress and eventual cell death, a characteristic of age-related pathology. Here, we explored the molecular mechanisms of D-serine (D-Ser) and D-alanine (D-Ala) in human liver cancer cells, HepG2, with a focus on the production of H2O2 the downstream secretion of pro-inflammatory cytokine and chemokine, and subsequent cell death. In HepG2 cells, we demonstrated that D-Ser decreased H2O2 production and induced concentration-dependent depolarization of mitochondrial membrane potential (MMP). This was associated with the upregulation of activated NF-кB, pro-inflammatory cytokine, TNF-α, and chemokine, IL-8 secretion, and subsequent apoptosis. Conversely, D-Ala-treated cells induced H2O2 production, and were also accompanied by the upregulation of activated NF-кB, TNF-α, and IL-8, but did not cause significant apoptosis. The present study confirms the role of both D-Ser and D-Ala in inducing inflammatory responses, but each via unique activation pathways. This response was associated with apoptotic cell death only with D-Ser. Further research is required to gain a better understanding of the mechanisms underlying D-AA-induced inflammation and its downstream consequences, especially in the context of aging given the wide detection of these entities in systemic circulation.
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Affiliation(s)
- Siew Hwei Yap
- Centre of Excellence for Research in AIDS (CERiA), Universiti Malaya, Kuala Lumpur, Malaysia
- Department of Medicine, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia
| | - Cheng Siang Lee
- Centre of Excellence for Research in AIDS (CERiA), Universiti Malaya, Kuala Lumpur, Malaysia
| | - Nur Diyana Zulkifli
- Department of Biomedical Sciences, Advanced Medical and Dental Institute, Universiti Sains Malaysia, Kepala Batas, Malaysia
| | - Darshinie Suresh
- Department of Biomedical Sciences, Advanced Medical and Dental Institute, Universiti Sains Malaysia, Kepala Batas, Malaysia
- Department of Biological Sciences and Biotechnology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, Bangi, Malaysia
| | - Kenji Hamase
- Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan
| | - Kumitaa Theva Das
- Department of Biomedical Sciences, Advanced Medical and Dental Institute, Universiti Sains Malaysia, Kepala Batas, Malaysia
| | - Reena Rajasuriar
- Centre of Excellence for Research in AIDS (CERiA), Universiti Malaya, Kuala Lumpur, Malaysia
- Department of Medicine, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia
- Peter Doherty Institute for Infection and Immunity, Melbourne University, Melbourne, VIC, Australia
| | - Kok Hoong Leong
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Universiti Malaya, Kuala Lumpur, Malaysia.
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3
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Katane M, Homma H. Biosynthesis and Degradation of Free D-Amino Acids and Their Physiological Roles in the Periphery and Endocrine Glands. Biol Pharm Bull 2024; 47:562-579. [PMID: 38432912 DOI: 10.1248/bpb.b23-00485] [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] [Indexed: 03/05/2024]
Abstract
It was long believed that D-amino acids were either unnatural isomers or laboratory artifacts, and that the important functions of amino acids were exerted only by L-amino acids. However, recent investigations have revealed a variety of D-amino acids in mammals that play important roles in physiological functions, including free D-serine and D-aspartate that are crucial in the central nervous system. The functions of several D-amino acids in the periphery and endocrine glands are also receiving increasing attention. Here, we present an overview of recent advances in elucidating the physiological roles of D-amino acids, especially in the periphery and endocrine glands.
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Affiliation(s)
- Masumi Katane
- Medicinal Research Laboratories, Graduate School of Pharmaceutical Sciences, Kitasato University
| | - Hiroshi Homma
- Laboratory of Analytical Chemistry, Graduate School of Pharmaceutical Sciences, Kitasato University
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4
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The Role of D-Serine and D-Aspartate in the Pathogenesis and Therapy of Treatment-Resistant Schizophrenia. Nutrients 2022; 14:nu14235142. [PMID: 36501171 PMCID: PMC9736950 DOI: 10.3390/nu14235142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Revised: 11/28/2022] [Accepted: 11/30/2022] [Indexed: 12/12/2022] Open
Abstract
Schizophrenia (Sch) is a severe and widespread mental disorder. Antipsychotics (APs) of the first and new generations as the first-line treatment of Sch are not effective in about a third of cases and are also unable to treat negative symptoms and cognitive deficits of schizophrenics. This explains the search for new therapeutic strategies for a disease-modifying therapy for treatment-resistant Sch (TRS). Biological compounds are of great interest to researchers and clinicians, among which D-Serine (D-Ser) and D-Aspartate (D-Asp) are among the promising ones. The Sch glutamate theory suggests that neurotransmission dysfunction caused by glutamate N-methyl-D-aspartate receptors (NMDARs) may represent a primary deficiency in this mental disorder and play an important role in the development of TRS. D-Ser and D-Asp are direct NMDAR agonists and may be involved in modulating the functional activity of dopaminergic neurons. This narrative review demonstrates both the biological role of D-Ser and D-Asp in the normal functioning of the central nervous system (CNS) and in the pathogenesis of Sch and TRS. Particular attention is paid to D-Ser and D-Asp as promising components of a nutritive disease-modifying therapy for TRS.
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5
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Kuo CY, Lin CH, Lane HY. Targeting D-Amino Acid Oxidase (DAAO) for the Treatment of Schizophrenia: Rationale and Current Status of Research. CNS Drugs 2022; 36:1143-1153. [PMID: 36194364 DOI: 10.1007/s40263-022-00959-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 09/14/2022] [Indexed: 11/29/2022]
Abstract
In the brain, D-amino acid oxidase (DAAO) is a peroxisomal flavoenzyme. Through oxidative deamination by DAAO, D-serine, the main coagonist of synaptic N-methyl-D-aspartate receptors (NMDARs), is degraded into α-keto acids and ammonia; flavin adenine dinucleotide (FAD) is simultaneously reduced to dihydroflavine-adenine dinucleotide (FADH2), which is subsequently reoxidized to FAD, with hydrogen peroxide produced as a byproduct. NMDAR hypofunction is implicated in the pathogenesis of schizophrenia. In previous studies, compared with control subjects, patients with schizophrenia had lower D-serine levels in peripheral blood and cerebrospinal fluid but higher DAAO expression and activity in the brain. Inhibiting DAAO activity and slowing D-serine degradation by using DAAO inhibitors to enhance NMDAR function may be a new strategy for use in the treatment of schizophrenia. The aim of this leading article is to review the current research in DAAO inhibitors.
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Affiliation(s)
- Chien-Yi Kuo
- Department of Psychiatry, China Medical University Hospital, No. 2, Yude Rd., North Dist., Taichung City, 404327, Taiwan, ROC.,Graduate Institute of Biomedical Sciences, China Medical University, No. 91, Xueshi Rd., North Dis., Taichung City, 404333, Taiwan, ROC
| | - Chieh-Hsin Lin
- Graduate Institute of Biomedical Sciences, China Medical University, No. 91, Xueshi Rd., North Dis., Taichung City, 404333, Taiwan, ROC. .,Department of Psychiatry, Kaohsiung Chang Gung Memorial Hospital, No. 123, Dapi Rd., Niaosong Dist., Kaohsiung City, 83301, Taiwan, ROC. .,School of Medicine, Chang Gung University, No. 259, Wenhua 1st Rd., Guishan Dist., Taoyuan City, 33302, Taiwan, ROC.
| | - Hsien-Yuan Lane
- Department of Psychiatry, China Medical University Hospital, No. 2, Yude Rd., North Dist., Taichung City, 404327, Taiwan, ROC. .,Graduate Institute of Biomedical Sciences, China Medical University, No. 91, Xueshi Rd., North Dis., Taichung City, 404333, Taiwan, ROC. .,Department of Psychology, College of Medical and Health Sciences, Asia University, No. 500, Lioufeng Rd., Wufeng Dist., Taichung City, 413305, Taiwan, ROC.
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6
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Bauminger H, Gaisler-Salomon I. Beyond NMDA Receptors: Homeostasis at the Glutamate Tripartite Synapse and Its Contributions to Cognitive Dysfunction in Schizophrenia. Int J Mol Sci 2022; 23:8617. [PMID: 35955750 PMCID: PMC9368772 DOI: 10.3390/ijms23158617] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Revised: 07/30/2022] [Accepted: 08/01/2022] [Indexed: 02/01/2023] Open
Abstract
Cognitive deficits are core symptoms of schizophrenia but remain poorly addressed by dopamine-based antipsychotic medications. Glutamate abnormalities are implicated in schizophrenia-related cognitive deficits. While the role of the NMDA receptor has been extensively studied, less attention was given to other components that control glutamate homeostasis. Glutamate dynamics at the tripartite synapse include presynaptic and postsynaptic components and are tightly regulated by neuron-astrocyte crosstalk. Here, we delineate the role of glutamate homeostasis at the tripartite synapse in schizophrenia-related cognitive dysfunction. We focus on cognitive domains that can be readily measured in humans and rodents, i.e., working memory, recognition memory, cognitive flexibility, and response inhibition. We describe tasks used to measure cognitive function in these domains in humans and rodents, and the relevance of glutamate alterations in these domains. Next, we delve into glutamate tripartite synaptic components and summarize findings that implicate the relevance of these components to specific cognitive domains. These collective findings indicate that neuron-astrocyte crosstalk at the tripartite synapse is essential for cognition, and that pre- and postsynaptic components play a critical role in maintaining glutamate homeostasis and cognitive well-being. The contribution of these components to cognitive function should be considered in order to better understand the role played by glutamate signaling in cognition and develop efficient pharmacological treatment avenues for schizophrenia treatment-resistant symptoms.
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Affiliation(s)
- Hagar Bauminger
- School of Psychological Sciences, Department of Psychology, University of Haifa, Haifa 3498838, Israel;
- The Integrated Brain and Behavior Research Center (IBBRC), University of Haifa, Haifa 3498838, Israel
| | - Inna Gaisler-Salomon
- School of Psychological Sciences, Department of Psychology, University of Haifa, Haifa 3498838, Israel;
- The Integrated Brain and Behavior Research Center (IBBRC), University of Haifa, Haifa 3498838, Israel
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de Bartolomeis A, Vellucci L, Austin MC, De Simone G, Barone A. Rational and Translational Implications of D-Amino Acids for Treatment-Resistant Schizophrenia: From Neurobiology to the Clinics. Biomolecules 2022; 12:biom12070909. [PMID: 35883465 PMCID: PMC9312470 DOI: 10.3390/biom12070909] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Revised: 06/25/2022] [Accepted: 06/26/2022] [Indexed: 12/13/2022] Open
Abstract
Schizophrenia has been conceptualized as a neurodevelopmental disorder with synaptic alterations and aberrant cortical–subcortical connections. Antipsychotics are the mainstay of schizophrenia treatment and nearly all share the common feature of dopamine D2 receptor occupancy, whereas glutamatergic abnormalities are not targeted by the presently available therapies. D-amino acids, acting as N-methyl-D-aspartate receptor (NMDAR) modulators, have emerged in the last few years as a potential augmentation strategy in those cases of schizophrenia that do not respond well to antipsychotics, a condition defined as treatment-resistant schizophrenia (TRS), affecting almost 30–40% of patients, and characterized by serious cognitive deficits and functional impairment. In the present systematic review, we address with a direct and reverse translational perspective the efficacy of D-amino acids, including D-serine, D-aspartate, and D-alanine, in poor responders. The impact of these molecules on the synaptic architecture is also considered in the light of dendritic spine changes reported in schizophrenia and antipsychotics’ effect on postsynaptic density proteins. Moreover, we describe compounds targeting D-amino acid oxidase and D-aspartate oxidase enzymes. Finally, other drugs acting at NMDAR and proxy of D-amino acids function, such as D-cycloserine, sarcosine, and glycine, are considered in the light of the clinical burden of TRS, together with other emerging molecules.
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Affiliation(s)
- Andrea de Bartolomeis
- Laboratory of Translational and Molecular Psychiatry and Unit of Treatment-Resistant Psychosis, Section of Psychiatry, Department of Neuroscience, Reproductive Sciences and Dentistry, University of Naples Federico II, 80131 Naples, Italy; (L.V.); (G.D.S.); (A.B.)
- Correspondence: ; Tel.: +39-081-7463673 or +39-081-7463884 or +39-3662745592; Fax: +39-081-7462644
| | - Licia Vellucci
- Laboratory of Translational and Molecular Psychiatry and Unit of Treatment-Resistant Psychosis, Section of Psychiatry, Department of Neuroscience, Reproductive Sciences and Dentistry, University of Naples Federico II, 80131 Naples, Italy; (L.V.); (G.D.S.); (A.B.)
| | - Mark C. Austin
- Clinical Psychopharmacology Program, College of Pharmacy, Idaho State University, Pocatello, ID 83209, USA;
| | - Giuseppe De Simone
- Laboratory of Translational and Molecular Psychiatry and Unit of Treatment-Resistant Psychosis, Section of Psychiatry, Department of Neuroscience, Reproductive Sciences and Dentistry, University of Naples Federico II, 80131 Naples, Italy; (L.V.); (G.D.S.); (A.B.)
| | - Annarita Barone
- Laboratory of Translational and Molecular Psychiatry and Unit of Treatment-Resistant Psychosis, Section of Psychiatry, Department of Neuroscience, Reproductive Sciences and Dentistry, University of Naples Federico II, 80131 Naples, Italy; (L.V.); (G.D.S.); (A.B.)
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8
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Gonda Y, Ishii C, Mita M, Nishizaki N, Ohtomo Y, Hamase K, Shimizu T, Sasabe J. Astrocytic D -amino acid oxidase degrades D -serine in the hindbrain. FEBS Lett 2022; 596:2889-2897. [PMID: 35665501 DOI: 10.1002/1873-3468.14417] [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: 03/29/2022] [Revised: 05/22/2022] [Accepted: 05/25/2022] [Indexed: 11/11/2022]
Abstract
D -serine modulates excitatory neurotransmission by binding to N-methyl-D -aspartate glutamate receptors. D- amino acid oxidase (DAO) degrades D -amino acids, such as D -serine, in the central nervous system, and is associated with neurological and psychiatric disorders. However, cell types that express brain DAO remain controversial, and whether brain DAO influences systemic D -amino acids in addition to brain D -serine remains unclear. Here, we created astrocyte-specific DAO-conditional knockout mice. Knockout in glial fibrillary acidic protein (GFAP)-positive cells eliminated DAO expression in the hindbrain and increased D -serine levels significantly in the cerebellum. Brain DAO did not influence levels of D -amino acids in the forebrain or periphery. These results show that astrocytic DAO regulates D -serine specifically in the hindbrain.
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Affiliation(s)
- Yusuke Gonda
- Department of Pharmacology, Keio University School of Medicine, 160-8582, Tokyo, Japan.,Department of Pediatrics and Adolescent Medicine, Juntendo University Graduate school of Medicine, 113-8431, Tokyo, Japan
| | - Chiharu Ishii
- Graduate School of Pharmaceutical Sciences, Kyushu University, 812-8582, Fukuoka, Japan
| | | | - Naoto Nishizaki
- Department of Pediatrics, Juntendo University Urayasu Hospital, 279-0021, Chiba, Japan
| | - Yoshiyuki Ohtomo
- Department of Pediatrics, Juntendo University Nerima Hospital, 177-8521, Tokyo, Japan
| | - Kenji Hamase
- Graduate School of Pharmaceutical Sciences, Kyushu University, 812-8582, Fukuoka, Japan
| | - Toshiaki Shimizu
- Department of Pediatrics and Adolescent Medicine, Juntendo University Graduate school of Medicine, 113-8431, Tokyo, Japan
| | - Jumpei Sasabe
- Department of Pharmacology, Keio University School of Medicine, 160-8582, Tokyo, Japan
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9
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Wu S, Zhou J, Zhang H, Barger SW. Serine Racemase Expression Differentiates Aging from Alzheimer's Brain. Curr Alzheimer Res 2022; 19:494-502. [PMID: 35929621 DOI: 10.2174/1567205019666220805105106] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Revised: 06/27/2022] [Accepted: 06/29/2022] [Indexed: 01/27/2023]
Abstract
Aging is an inevitable process characterized by progressive loss of physiological integrity and increased susceptibility to cancer, diabetes, cardiovascular, and neurodegenerative diseases; aging is the primary risk factor for Alzheimer's disease (AD), the most common cause of dementia. AD is characterized by brain pathology, including extracellular deposition of amyloid aggregation and intracellular accumulation of neurofibrillary tangles composed of hyperphosphorylated tau protein. In addition, losses of synapses and a wide range of neurons are pivotal pathologies in the AD brain. Accumulating evidence demonstrates hypoactivation of hippocampal neural networks in the aging brain, whereas AD-related mild cognitive impairment (AD-MCI) begins with hyperactivation, followed by a diminution of hippocampal activity as AD develops. The biphasic trends of the activity of the hippocampal neural network are consistent with the alteration of N-methyl-D-aspartate receptor (NMDA-R) activity from aging to prodromal (AD-MCI) to mid-/late stage AD. D-serine, a product of racemization catalyzed by serine racemase (SR), is an important co-agonist of the NMDA-R which is involved in synaptic events including neurotransmission, synaptogenesis, long-term potentiation (LTP), development, and excitotoxicity. SR and D-serine are decreased in the hippocampus of the aging brain, correlating with impairment of cognitive function. By contrast, SR is increased in AD brain, which is associated with a greater degree of cognitive dysfunction. Emerging studies suggest that D-serine levels in the brain or in cerebral spinal fluid from AD patients are higher than in age-matched controls, but the results are inconsistent. Very recently, serum D-serine levels in AD were reported to correlate with sex and clinical dementia rating (CDR) stage. This review will discuss alterations of NMDA-R and SR in aging and AD brain, and the mechanisms underlying the differential regulation of SR will be probed. Collectively, we propose that SR may be a molecular switch that distinguishes the effects of aging from those of AD on the brain.
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Affiliation(s)
- Shengzhou Wu
- School of Optometry and Ophthalmology and the Eye Hospital, Wenzhou Medical University, State Key Laboratory of Optometry, Wenzhou, Zhejiang 325003, P.R. China
| | - Jing Zhou
- School of Optometry and Ophthalmology and the Eye Hospital, Wenzhou Medical University, State Key Laboratory of Optometry, Wenzhou, Zhejiang 325003, P.R. China
| | - He Zhang
- School of Optometry and Ophthalmology and the Eye Hospital, Wenzhou Medical University, State Key Laboratory of Optometry, Wenzhou, Zhejiang 325003, P.R. China.,College of Life and Environmental Sciences, Wenzhou University, Wenzhou, Zhejiang, P.R. China
| | - Steven W Barger
- Department of Geriatrics, University of Arkansas for Medical Sciences, Little Rock AR, USA.,Geriatric Research, Education & Clinical Center, Central Arkansas Veterans Healthcare System, Little Rock AR, USA
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10
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Shindo T, Shikanai H, Watarai A, Hiraide S, Iizuka K, Izumi T. D-serine metabolism in the medial prefrontal cortex, but not the hippocampus, is involved in AD/HD-like behaviors in SHRSP/Ezo. Eur J Pharmacol 2022; 923:174930. [PMID: 35364072 DOI: 10.1016/j.ejphar.2022.174930] [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: 06/16/2021] [Revised: 03/03/2022] [Accepted: 03/25/2022] [Indexed: 12/26/2022]
Abstract
Attention-deficit/hyperactivity disorder (AD/HD) is a mild neurodevelopmental disorder with inattention, hyperactivity, and impulsivity as its core symptoms. We previously revealed that an AD/HD animal model, juvenile stroke-prone spontaneously hypertensive rats (SHRSP/Ezo) exhibited functional abnormalities in N-methyl-D-aspartate (NMDA) receptors in the prefrontal cortex. D-serine is an endogenous co-ligand that acts on the glycine-binding site of NMDA receptors, which is essential for the physiological activation of NMDA receptors. We herein performed neurochemical and pharmacological behavioral experiments to elucidate dysfunctions in D-serine metabolism (namely, biosynthesis and catabolism) associated to AD/HD. The serine enantiomers ratio (D-serine/D-serine + L-serine, DL ratio) in the medial prefrontal cortex (mPFC) and hippocampus (HIP) was lower in SHRSP/Ezo than in its genetic control. The level of D-amino acid oxidase (DAAO, D-serine degrading enzyme) was higher in the mPFC, and the level of serine racemase (SR, D-serine biosynthetic enzyme), was lower in the HIP in SHRSP/Ezo. Thus, changes in these enzymes may contribute to the lower DL ratio of SHRSP/Ezo. Moreover, a microinjection of a DAAO inhibitor into the mPFC in SHRSP/Ezo increased DL ratio and attenuated AD/HD-like behaviors, such as inattention and hyperactivity, in the Y-maze test. Injection into the HIP also increased the DL ratio, but had no effect on behaviors. These results suggest that AD/HD-like behaviors in SHRSP/Ezo are associated with an abnormal D-serine metabolism underlying NMDA receptor dysfunction in the mPFC. These results will contribute to elucidating the pathogenesis of AD/HD and the development of new treatment strategies for AD/HD.
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Affiliation(s)
- Tsugumi Shindo
- Department of Pharmacology, Faculty of Pharmaceutical Sciences, Health Science University of Hokkaido, Japan
| | - Hiroki Shikanai
- Department of Pharmacology, Faculty of Pharmaceutical Sciences, Health Science University of Hokkaido, Japan; Advanced Research Promotion Center, Health Science University of Hokkaido, Japan.
| | - Akane Watarai
- Department of Pharmacology, Faculty of Pharmaceutical Sciences, Health Science University of Hokkaido, Japan
| | - Sachiko Hiraide
- Department of Pharmacology, Faculty of Pharmaceutical Sciences, Health Science University of Hokkaido, Japan
| | - Kenji Iizuka
- Department of Pharmacology, Faculty of Pharmaceutical Sciences, Health Science University of Hokkaido, Japan
| | - Takeshi Izumi
- Department of Pharmacology, Faculty of Pharmaceutical Sciences, Health Science University of Hokkaido, Japan; Advanced Research Promotion Center, Health Science University of Hokkaido, Japan
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11
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Wang J, Serratrice N, Lee CJ, François F, Sweedler JV, Puel JL, Mothet JP, Ruel J. Physiopathological Relevance of D-Serine in the Mammalian Cochlea. Front Cell Neurosci 2022; 15:733004. [PMID: 34975405 PMCID: PMC8718999 DOI: 10.3389/fncel.2021.733004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Accepted: 11/29/2021] [Indexed: 12/02/2022] Open
Abstract
NMDA receptors (NMDARs) populate the complex between inner hair cell (IHC) and spiral ganglion neurons (SGNs) in the developing and mature cochlea. However, in the mature cochlea, activation of NMDARs is thought to mainly occur under pathological conditions such as excitotoxicity. Ototoxic drugs such as aspirin enable cochlear arachidonic-acid-sensitive NMDAR responses, and induced chronic tinnitus was blocked by local application of NMDAR antagonists into the cochlear fluids. We largely ignore if other modulators are also engaged. In the brain, D-serine is the primary physiological co-agonist of synaptic NMDARs. Whether D-serine plays a role in the cochlea had remained unexplored. We now reveal the presence of D-serine and its metabolic enzymes prior to, and at hearing onset, in the sensory and non-neuronal cells of the cochlea of several vertebrate species. In vivo intracochlear perfusion of D-serine in guinea pigs reduces sound-evoked activity of auditory nerve fibers without affecting the receptor potentials, suggesting that D-serine acts specifically on the postsynaptic auditory neurons without altering the functional state of IHC or of the stria vascularis. Indeed, we demonstrate in vitro that agonist-induced activation of NMDARs produces robust calcium responses in rat SGN somata only in the presence of D-serine, but not of glycine. Surprisingly, genetic deletion in mice of serine racemase (SR), the enzyme that catalyzes D-serine, does not affect hearing function, but offers protection against noise-induced permanent hearing loss as measured 3 months after exposure. However, the mechanisms of activation of NMDA receptors in newborn rats may be different from those in adult guinea pigs. Taken together, these results demonstrate for the first time that the neuro-messenger D-serine has a pivotal role in the cochlea by promoting the activation of silent cochlear NMDAR in pathological situations. Thus, D-serine and its signaling pathway may represent a new druggable target for treating sensorineural hearing disorders (i.e., hearing loss, tinnitus).
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Affiliation(s)
- Jing Wang
- Institute for Neurosciences of Montpellier (INM), University Montpellier, Institut National de la Santé et de la Recherche Médicale (INSERM), Montpellier, France.,ENT Department, Hospital and University of Montpellier, Montpellier, France
| | - Nicolas Serratrice
- Institute for Neurosciences of Montpellier (INM), University Montpellier, Institut National de la Santé et de la Recherche Médicale (INSERM), Montpellier, France
| | - Cindy J Lee
- Department of Chemistry, Beckman Institute, University of Illinois at Urbana-Champaign, Urbana, IL, United States
| | - Florence François
- Institute for Neurosciences of Montpellier (INM), University Montpellier, Institut National de la Santé et de la Recherche Médicale (INSERM), Montpellier, France
| | - Jonathan V Sweedler
- Department of Chemistry, Beckman Institute, University of Illinois at Urbana-Champaign, Urbana, IL, United States
| | - Jean-Luc Puel
- Institute for Neurosciences of Montpellier (INM), University Montpellier, Institut National de la Santé et de la Recherche Médicale (INSERM), Montpellier, France
| | - Jean-Pierre Mothet
- Laboratoire LuMin, Biophotonics and Synapse Physiopathology Team, Université Paris-Saclay, Centre National de la Recherche Scientifique (CNRS), ENS Paris Saclay, Centrale Supélec, Gif-sur-Yvette, France
| | - Jérôme Ruel
- Institute for Neurosciences of Montpellier (INM), University Montpellier, Institut National de la Santé et de la Recherche Médicale (INSERM), Montpellier, France.,Aix-Marseille Université, Centre National de la Recherche Scientifique (CNRS), Laboratoire de Neurosciences Cognitives, Marseille, France
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12
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d-Amino Acids and pLG72 in Alzheimer's Disease and Schizophrenia. Int J Mol Sci 2021; 22:ijms222010917. [PMID: 34681579 PMCID: PMC8535920 DOI: 10.3390/ijms222010917] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 10/01/2021] [Accepted: 10/06/2021] [Indexed: 01/02/2023] Open
Abstract
Numerous studies over the last several years have shown that d-amino acids, especially d-serine, have been related to brain and neurological disorders. Acknowledged neurological functions of d-amino acids include neurotransmission and learning and memory functions through modulating N-methyl-d-aspartate type glutamate receptors (NMDARs). Aberrant d-amino acids level and polymorphisms of genes related to d-amino acids metabolism are associated with neurodegenerative brain conditions. This review summarizes the roles of d-amino acids and pLG72, also known as d-amino acid oxidase activator, on two neurodegenerative disorders, schizophrenia and Alzheimer’s disease (AD). The scope includes the changes in d-amino acids levels, gene polymorphisms of G72 genomics, and the role of pLG72 on NMDARs and mitochondria in schizophrenia and AD. The clinical diagnostic value of d-amino acids and pLG72 and the therapeutic importance are also reviewed.
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13
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Cystine/Glutamate Antiporter in Schizophrenia: From Molecular Mechanism to Novel Biomarker and Treatment. Int J Mol Sci 2021; 22:ijms22189718. [PMID: 34575878 PMCID: PMC8466274 DOI: 10.3390/ijms22189718] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Revised: 09/06/2021] [Accepted: 09/06/2021] [Indexed: 01/04/2023] Open
Abstract
Glutamate, a crucial excitatory neurotransmitter, plays a major role in the modulation of schizophrenia’s pathogenesis. New drug developments for schizophrenia have been prompted by the hypoglutamatergic hypothesis of schizophrenia. The cystine/glutamate antiporter system xc− is related to glutamate-release regulation. Patients with schizophrenia were recently discovered to exhibit downregulation of xc− subunits—the solute carrier (SLC) family 3 member 2 and the SLC family 7 member 11. We searched for relevant studies from 1980, when Bannai and Kitamura first identified the protein subunit system xc− in lung fibroblasts, with the aim of compiling the biological, functional, and pharmacological characteristics of antiporter xc−, which consists of several subunits. Some of them can significantly stimulate the human brain through the glutamate pathway. Initially, extracellular cysteine activates neuronal xc−, causing glutamate efflux. Next, excitatory amino acid transporters enhance the unidirectional transportation of glutamate and sodium. These two biochemical pathways are also crucial to the production of glutathione, a protective agent for neural and glial cells and astrocytes. Investigation of the expression of system xc− genes in the peripheral white blood cells of patients with schizophrenia can facilitate better understanding of the mental disorder and future development of novel biomarkers and treatments for schizophrenia. In addition, the findings further support the hypoglutamatergic hypothesis of schizophrenia.
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14
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Meftah A, Hasegawa H, Kantrowitz JT. D-Serine: A Cross Species Review of Safety. Front Psychiatry 2021; 12:726365. [PMID: 34447324 PMCID: PMC8384137 DOI: 10.3389/fpsyt.2021.726365] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Accepted: 07/13/2021] [Indexed: 12/18/2022] Open
Abstract
Background:D-Serine, a direct, full agonist at the D-serine/glycine modulatory site of the N-methyl-D-aspartate-type glutamate receptors (NMDAR), has been assessed as a treatment for multiple psychiatric and neurological conditions. Based on studies in rats, concerns of nephrotoxicity have limited D-serine research in humans, particularly using high doses. A review of D-serine's safety is timely and pertinent, as D-serine remains under active study for schizophrenia, both directly (R61 MH116093) and indirectly through D-amino acid oxidase (DAAO) inhibitors. The principal focus is on nephrotoxicity, but safety in other physiologic and pathophysiologic systems are also reviewed. Methods: Using the search terms "D-serine," "D-serine and schizophrenia," "D-serine and safety," "D-serine and nephrotoxicity" in PubMed, we conducted a systematic review on D-serine safety. D-serine physiology, dose-response and efficacy in clinical studies and dAAO inhibitor safety is also discussed. Results: When D-serine doses >500 mg/kg are used in rats, nephrotoxicity, manifesting as an acute tubular necrosis syndrome, seen within hours of administration is highly common, if not universal. In other species, however, D-serine induced nephrotoxicity has not been reported, even in other rodent species such as mice and rabbits. Even in rats, D--serine related toxicity is dose dependent and reversible; and does not appear to be present in rats at doses producing an acute Cmax of <2,000 nmol/mL. For comparison, the Cmax of D-serine 120 mg/kg, the highest dose tested in humans, is ~500 nmol/mL in acute dosing. Across all published human studies, only one subject has been reported to have abnormal renal values related to D-serine treatment. This abnormality did not clearly map on to the acute tubular necrosis syndrome seen in rats, and fully resolved within a few days of stopping treatment. DAAO inhibitors may be nephroprotective. D-Serine may have a physiologic role in metabolic, extra-pyramidal, cardiac and other systems, but no other clinically significant safety concerns are revealed in the literature. Conclusions: Even before considering human to rat differences in renal physiology, using current FDA guided monitoring paradigms, D-serine appears safe at currently studied maximal doses, with potential safety in combination with DAAO inhibitors.
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Affiliation(s)
- Amir Meftah
- College of Physicians and Surgeons, Columbia University, New York City, NY, United States
- New York State Psychiatric Institute, New York City, NY, United States
| | - Hiroshi Hasegawa
- Department of Pathophysiology, Tokyo University of Pharmacy and Life Sciences, Tokyo, Japan
| | - Joshua T. Kantrowitz
- College of Physicians and Surgeons, Columbia University, New York City, NY, United States
- New York State Psychiatric Institute, New York City, NY, United States
- Nathan Kline Institute, Orangeburg, NY, United States
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15
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Sherwood MW, Oliet SHR, Panatier A. NMDARs, Coincidence Detectors of Astrocytic and Neuronal Activities. Int J Mol Sci 2021; 22:7258. [PMID: 34298875 PMCID: PMC8307462 DOI: 10.3390/ijms22147258] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 06/30/2021] [Accepted: 06/30/2021] [Indexed: 12/18/2022] Open
Abstract
Synaptic plasticity is an extensively studied cellular correlate of learning and memory in which NMDARs play a starring role. One of the most interesting features of NMDARs is their ability to act as a co-incident detector. It is unique amongst neurotransmitter receptors in this respect. Co-incident detection is possible because the opening of NMDARs requires membrane depolarisation and the binding of glutamate. Opening of NMDARs also requires a co-agonist. Although the dynamic regulation of glutamate and membrane depolarization have been well studied in coincident detection, the role of the co-agonist site is unexplored. It turns out that non-neuronal glial cells, astrocytes, regulate co-agonist availability, giving them the ability to influence synaptic plasticity. The unique morphology and spatial arrangement of astrocytes at the synaptic level affords them the capacity to sample and integrate information originating from unrelated synapses, regardless of any pre-synaptic and post-synaptic commonality. As astrocytes are classically considered slow responders, their influence at the synapse is widely recognized as modulatory. The aim herein is to reconsider the potential of astrocytes to participate directly in ongoing synaptic NMDAR activity and co-incident detection.
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Affiliation(s)
- Mark W. Sherwood
- University of Bordeaux, INSERM, Neurocentre Magendie, U1215, F-3300 Bordeaux, France;
| | | | - Aude Panatier
- University of Bordeaux, INSERM, Neurocentre Magendie, U1215, F-3300 Bordeaux, France;
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16
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Pollegioni L, Molla G, Sacchi S, Murtas G. Human D-aspartate Oxidase: A Key Player in D-aspartate Metabolism. Front Mol Biosci 2021; 8:689719. [PMID: 34250021 PMCID: PMC8260693 DOI: 10.3389/fmolb.2021.689719] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Accepted: 06/09/2021] [Indexed: 11/15/2022] Open
Abstract
In recent years, the D-enantiomers of amino acids have been recognized as natural molecules present in all kingdoms, playing a variety of biological roles. In humans, d-serine and d-aspartate attracted attention for their presence in the central nervous system. Here, we focus on d-aspartate, which is involved in glutamatergic neurotransmission and the synthesis of various hormones. The biosynthesis of d-aspartate is still obscure, while its degradation is due to the peroxisomal flavin adenine dinucleotide (FAD)-containing enzyme d-aspartate oxidase. d-Aspartate emergence is strictly controlled: levels decrease in brain within the first days of life while increasing in endocrine glands postnatally and through adulthood. The human d-aspartate oxidase (hDASPO) belongs to the d-amino acid oxidase-like family: its tertiary structure closely resembles that of human d-amino acid oxidase (hDAAO), the enzyme that degrades neutral and basic d-amino acids. The structure-function relationships of the physiological isoform of hDASPO (named hDASPO_341) and the regulation of gene expression and distribution and properties of the longer isoform hDASPO_369 have all been recently elucidated. Beyond the substrate preference, hDASPO and hDAAO also differ in kinetic efficiency, FAD-binding affinity, pH profile, and oligomeric state. Such differences suggest that evolution diverged to create two different ways to modulate d-aspartate and d-serine levels in the human brain. Current knowledge about hDASPO is shedding light on the molecular mechanisms underlying the modulation of d-aspartate levels in human tissues and is pushing novel, targeted therapeutic strategies. Now, it has been proposed that dysfunction in NMDA receptor-mediated neurotransmission is caused by disrupted d-aspartate metabolism in the nervous system during the onset of various disorders (such as schizophrenia): the design of suitable hDASPO inhibitors aimed at increasing d-aspartate levels thus represents a novel and useful form of therapy.
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Affiliation(s)
- Loredano Pollegioni
- Department of Biotechnology and Life Sciences, University of Insubria, Varese, Italy
| | - Gianluca Molla
- Department of Biotechnology and Life Sciences, University of Insubria, Varese, Italy
| | - Silvia Sacchi
- Department of Biotechnology and Life Sciences, University of Insubria, Varese, Italy
| | - Giulia Murtas
- Department of Biotechnology and Life Sciences, University of Insubria, Varese, Italy
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17
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Sacchi S, Rabattoni V, Miceli M, Pollegioni L. Yin and Yang in Post-Translational Modifications of Human D-Amino Acid Oxidase. Front Mol Biosci 2021; 8:684934. [PMID: 34041270 PMCID: PMC8141710 DOI: 10.3389/fmolb.2021.684934] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Accepted: 04/23/2021] [Indexed: 11/30/2022] Open
Abstract
In the central nervous system, the flavoprotein D-amino acid oxidase is responsible for catabolizing D-serine, the main endogenous coagonist of N-methyl-D-aspartate receptor. Dysregulation of D-serine brain levels in humans has been associated with neurodegenerative and psychiatric disorders. This D-amino acid is synthesized by the enzyme serine racemase, starting from the corresponding L-enantiomer, and degraded by both serine racemase (via an elimination reaction) and the flavoenzyme D-amino acid oxidase. To shed light on the role of human D-amino acid oxidase (hDAAO) in D-serine metabolism, the structural/functional relationships of this enzyme have been investigated in depth and several strategies aimed at controlling the enzymatic activity have been identified. Here, we focused on the effect of post-translational modifications: by using a combination of structural analyses, biochemical methods, and cellular studies, we investigated whether hDAAO is subjected to nitrosylation, sulfhydration, and phosphorylation. hDAAO is S-nitrosylated and this negatively affects its activity. In contrast, the hydrogen sulfide donor NaHS seems to alter the enzyme conformation, stabilizing a species with higher affinity for the flavin adenine dinucleotide cofactor and thus positively affecting enzymatic activity. Moreover, hDAAO is phosphorylated in cerebellum; however, the protein kinase involved is still unknown. Taken together, these findings indicate that D-serine levels can be also modulated by post-translational modifications of hDAAO as also known for the D-serine synthetic enzyme serine racemase.
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Affiliation(s)
- Silvia Sacchi
- "The Protein Factory 2.0", Dipartimento di Biotecnologie e Scienze della Vita, Università degli Studi Dell'Insubria, Varese, Italy
| | - Valentina Rabattoni
- "The Protein Factory 2.0", Dipartimento di Biotecnologie e Scienze della Vita, Università degli Studi Dell'Insubria, Varese, Italy
| | - Matteo Miceli
- "The Protein Factory 2.0", Dipartimento di Biotecnologie e Scienze della Vita, Università degli Studi Dell'Insubria, Varese, Italy
| | - Loredano Pollegioni
- "The Protein Factory 2.0", Dipartimento di Biotecnologie e Scienze della Vita, Università degli Studi Dell'Insubria, Varese, Italy
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18
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Pei JC, Luo DZ, Gau SS, Chang CY, Lai WS. Directly and Indirectly Targeting the Glycine Modulatory Site to Modulate NMDA Receptor Function to Address Unmet Medical Needs of Patients With Schizophrenia. Front Psychiatry 2021; 12:742058. [PMID: 34658976 PMCID: PMC8517243 DOI: 10.3389/fpsyt.2021.742058] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Accepted: 09/02/2021] [Indexed: 12/30/2022] Open
Abstract
Schizophrenia is a severe mental illness that affects ~1% of the world's population. It is clinically characterized by positive, negative, and cognitive symptoms. Currently available antipsychotic medications are relatively ineffective in improving negative and cognitive deficits, which are related to a patient's functional outcomes and quality of life. Negative symptoms and cognitive deficits are unmet by the antipsychotic medications developed to date. In recent decades, compelling animal and clinical studies have supported the NMDA receptor (NMDAR) hypofunction hypothesis of schizophrenia and have suggested some promising therapeutic agents. Notably, several NMDAR-enhancing agents, especially those that function through the glycine modulatory site (GMS) of NMDAR, cause significant reduction in psychotic and cognitive symptoms in patients with schizophrenia. Given that the NMDAR-mediated signaling pathway has been implicated in cognitive/social functions and that GMS is a potential therapeutic target for enhancing the activation of NMDARs, there is great interest in investigating the effects of direct and indirect GMS modulators and their therapeutic potential. In this review, we focus on describing preclinical and clinical studies of direct and indirect GMS modulators in the treatment of schizophrenia, including glycine, D-cycloserine, D-serine, glycine transporter 1 (GlyT1) inhibitors, and D-amino acid oxidase (DAO or DAAO) inhibitors. We highlight some of the most promising recently developed pharmacological compounds designed to either directly or indirectly target GMS and thus augment NMDAR function to treat the cognitive and negative symptoms of schizophrenia. Overall, the current findings suggest that indirectly targeting of GMS appears to be more beneficial and leads to less adverse effects than direct targeting of GMS to modulate NMDAR functions. Indirect GMS modulators, especially GlyT1 inhibitors and DAO inhibitors, open new avenues for the treatment of unmet medical needs for patients with schizophrenia.
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Affiliation(s)
- Ju-Chun Pei
- Department of Psychology, National Taiwan University, Taipei, Taiwan
| | - Da-Zhong Luo
- Department of Psychology, National Taiwan University, Taipei, Taiwan
| | - Shiang-Shin Gau
- Department of Psychology, National Taiwan University, Taipei, Taiwan
| | - Chia-Yuan Chang
- Department of Psychology, National Taiwan University, Taipei, Taiwan.,Neurobiology and Cognitive Science Center, National Taiwan University, Taipei, Taiwan
| | - Wen-Sung Lai
- Department of Psychology, National Taiwan University, Taipei, Taiwan.,Neurobiology and Cognitive Science Center, National Taiwan University, Taipei, Taiwan.,Graduate Institute of Brain and Mind Sciences, National Taiwan University, Taipei, Taiwan
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19
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Nagy LV, Bali ZK, Kapus G, Pelsőczi P, Farkas B, Lendvai B, Lévay G, Hernádi I. Converging Evidence on D-Amino Acid Oxidase-Dependent Enhancement of Hippocampal Firing Activity and Passive Avoidance Learning in Rats. Int J Neuropsychopharmacol 2020; 24:434-445. [PMID: 33305805 PMCID: PMC8130201 DOI: 10.1093/ijnp/pyaa095] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 12/02/2020] [Accepted: 12/08/2020] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND N-methyl-D-aspartate (NMDA) receptor activation requires the binding of a co-agonist on the glycine-binding site. D-serine is the main endogenous co-agonist of NMDA receptors, and its availability significantly depends on the activity of the metabolic enzyme D-amino acid oxidase (DAAO). Inhibition of DAAO increases the brain levels of D-serine and modulates a variety of physiological functions, including cognitive behavior. METHODS Here, we examined the effects of a novel 4-hydroxypyridazin-3(2H)-one derivative DAAO inhibitor, Compound 30 (CPD30), on passive avoidance learning and on neuronal firing activity in rats. RESULTS D-serine administration was applied as reference, which increased cognitive performance and enhanced hippocampal firing activity and responsiveness to NMDA after both local and systemic application. Similarly to D-serine, CPD30 (0.1 mg/kg) effectively reversed MK-801-induced memory impairment in the passive avoidance test. Furthermore, local iontophoretic application of CPD30 in the vicinity of hippocampal pyramidal neurons significantly increased firing rate and enhanced their responses to locally applied NMDA. CPD30 also enhanced hippocampal firing activity after systemic administration. In 0.1- to 1.0-mg/kg doses, CPD30 increased spontaneous and NMDA-evoked firing activity of the neurons. Effects of CPD30 on NMDA responsiveness emerged faster (at 10 minutes post-injection) when a 1.0-mg/kg dose was applied compared with the onset of the effects of 0.1 mg/kg CPD30 (at 30 minutes post-injection). CONCLUSIONS The present results confirm that the inhibition of DAAO enzyme is an effective strategy for cognitive enhancement. Our findings further facilitate the understanding of the cellular mechanisms underlying the behavioral effects of DAAO inhibition in the mammalian brain.
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Affiliation(s)
- Lili Veronika Nagy
- Department of Experimental Zoology and Neurobiology, Faculty of Sciences, University of Pécs, Pécs, Hungary,Szentágothai Research Center, Center for Neuroscience, University of Pécs, Pécs, Hungary
| | - Zsolt Kristóf Bali
- Szentágothai Research Center, Center for Neuroscience, University of Pécs, Pécs, Hungary,Grastyán Translational Research Center, University of Pécs, Pécs, Hungary,Institute of Physiology, Medical School, University of Pécs, Pécs, Hungary,Correspondence: Zsolt Kristóf Bali, PhD, Translational Neuroscience Research Group, Grastyán Translational Research Center, 6 Ifjúság út, H-7624, Pécs, Hungary ()
| | - Gábor Kapus
- Pharmacological and Drug Safety Research, Gedeon Richter Plc, Budapest, Hungary
| | - Péter Pelsőczi
- Pharmacological and Drug Safety Research, Gedeon Richter Plc, Budapest, Hungary
| | - Bence Farkas
- Pharmacological and Drug Safety Research, Gedeon Richter Plc, Budapest, Hungary
| | - Balázs Lendvai
- Pharmacological and Drug Safety Research, Gedeon Richter Plc, Budapest, Hungary
| | - György Lévay
- Pharmacological and Drug Safety Research, Gedeon Richter Plc, Budapest, Hungary,Department of Morphology and Physiology, Faculty of Health Sciences, Semmelweis University, Budapest, Hungary
| | - István Hernádi
- Department of Experimental Zoology and Neurobiology, Faculty of Sciences, University of Pécs, Pécs, Hungary,Szentágothai Research Center, Center for Neuroscience, University of Pécs, Pécs, Hungary,Grastyán Translational Research Center, University of Pécs, Pécs, Hungary,Institute of Physiology, Medical School, University of Pécs, Pécs, Hungary
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20
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Deng X, Zhang Y, Chen Z, Kumata K, Van R, Rong J, Shao T, Hatori A, Mori W, Yu Q, Hu K, Fujinaga M, Wey HY, Shao Y, Josephson L, Murtas G, Pollegioni L, Zhang MR, Liang S. Synthesis and preliminary evaluation of 4-hydroxy-6-(3-[ 11C]methoxyphenethyl)pyridazin-3(2H)-one, a 11C-labeled d-amino acid oxidase (DAAO) inhibitor for PET imaging. Bioorg Med Chem Lett 2020; 30:127326. [PMID: 32631531 DOI: 10.1016/j.bmcl.2020.127326] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 06/03/2020] [Accepted: 06/04/2020] [Indexed: 11/19/2022]
Abstract
Selective DAAO inhibitors have demonstrated promising therapeutic effects in clinical studies, including clinically alleviating symptoms of schizophrenic patients and ameliorating cognitive function in Alzheimer's patients with early phase. Herein we report the synthesis and preliminary evaluation of a 11C-labeled positron emission tomography ligand based on a DAAO inhibitor, DAO-1903 (8). 11C-Isotopologue of 8 was prepared in high radiochemical yield with high radiochemical purity (>99%) and high molar activity (>37 GBq/µmol). In vitro autoradiography studies indicated that the ligand possessed high in vitro specific binding to DAAO, while in vivo dynamic PET studies demonstrated that [11C]8 failed to cross the blood-brain barrier possibly due to moderate brain efflux mechanism. Further chemical scaffold optimization is necessary to overcome limited brain permeability and improve specific binding.
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Affiliation(s)
- Xiaoyun Deng
- Department of Radiology, Massachusetts General Hospital and Harvard Medical School, 55 Fruit Street, Boston, MA 02114, United States
| | - Yiding Zhang
- Department of Radiopharmaceutics Development, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba 263-8555, Japan
| | - Zhen Chen
- Department of Radiology, Massachusetts General Hospital and Harvard Medical School, 55 Fruit Street, Boston, MA 02114, United States
| | - Katsushi Kumata
- Department of Radiopharmaceutics Development, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba 263-8555, Japan
| | - Richard Van
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, OK 73019, United States
| | - Jian Rong
- Department of Radiology, Massachusetts General Hospital and Harvard Medical School, 55 Fruit Street, Boston, MA 02114, United States
| | - Tuo Shao
- Department of Radiology, Massachusetts General Hospital and Harvard Medical School, 55 Fruit Street, Boston, MA 02114, United States
| | - Akiko Hatori
- Department of Radiopharmaceutics Development, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba 263-8555, Japan
| | - Wakana Mori
- Department of Radiopharmaceutics Development, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba 263-8555, Japan
| | - Qingzhen Yu
- Department of Radiology, Massachusetts General Hospital and Harvard Medical School, 55 Fruit Street, Boston, MA 02114, United States
| | - Kuan Hu
- Department of Radiopharmaceutics Development, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba 263-8555, Japan
| | - Masayuki Fujinaga
- Department of Radiopharmaceutics Development, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba 263-8555, Japan
| | - Hsiao-Ying Wey
- Department of Radiology, Massachusetts General Hospital and Harvard Medical School, 55 Fruit Street, Boston, MA 02114, United States
| | - Yihan Shao
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, OK 73019, United States
| | - Lee Josephson
- Department of Radiology, Massachusetts General Hospital and Harvard Medical School, 55 Fruit Street, Boston, MA 02114, United States
| | - Giulia Murtas
- Dipartimento di Biotecnologie e Scienze della Vita, Università degli Studi dell'Insubria, Varese 21100, Italy
| | - Loredano Pollegioni
- Dipartimento di Biotecnologie e Scienze della Vita, Università degli Studi dell'Insubria, Varese 21100, Italy
| | - Ming-Rong Zhang
- Department of Radiopharmaceutics Development, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba 263-8555, Japan.
| | - Steven Liang
- Department of Radiology, Massachusetts General Hospital and Harvard Medical School, 55 Fruit Street, Boston, MA 02114, United States.
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21
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Schoonover KE, Dienel SJ, Lewis DA. Prefrontal cortical alterations of glutamate and GABA neurotransmission in schizophrenia: Insights for rational biomarker development. Biomark Neuropsychiatry 2020; 3. [PMID: 32656540 PMCID: PMC7351254 DOI: 10.1016/j.bionps.2020.100015] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Certain cognitive deficits in schizophrenia, such as impaired working memory, are thought to reflect alterations in the neural circuitry of the dorsolateral prefrontal cortex (DLPFC). Gamma oscillations in the DLPFC appear to be a neural corollary of working memory function, and the power of these oscillations during working memory tasks is lower in individuals with schizophrenia. Thus, gamma oscillations represent a potentially useful biomarker to index dysfunction in the DLPFC circuitry responsible for working memory in schizophrenia. Postmortem studies, by identifying the cellular basis of DLPFC dysfunction, can help inform the utility of biomarker measures obtained in vivo. Given that gamma oscillations reflect network activity of excitatory pyramidal neurons and inhibitory GABA neurons, we review postmortem findings of alterations to both cell types in the DLPFC and discuss how these findings might inform future biomarker development and use.
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Affiliation(s)
- Kirsten E Schoonover
- Translational Neuroscience Program, Department of Psychiatry, School of Medicine, University of Pittsburgh, United States
| | - Samuel J Dienel
- Translational Neuroscience Program, Department of Psychiatry, School of Medicine, University of Pittsburgh, United States.,Medical Scientist Training Program, University of Pittsburgh, United States.,Department of Neuroscience, Dietrich School of Arts and Sciences, University of Pittsburgh, United States.,Center for the Neural Basis of Cognition, Carnegie Mellon University, United States
| | - David A Lewis
- Translational Neuroscience Program, Department of Psychiatry, School of Medicine, University of Pittsburgh, United States.,Department of Neuroscience, Dietrich School of Arts and Sciences, University of Pittsburgh, United States.,Center for the Neural Basis of Cognition, Carnegie Mellon University, United States
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22
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Murtas G, Sacchi S, Pollegioni L. Substitution of Arginine 120 in Human D-Amino Acid Oxidase Favors FAD-Binding and Nuclear Mistargeting. Front Mol Biosci 2019; 6:125. [PMID: 31799256 PMCID: PMC6862323 DOI: 10.3389/fmolb.2019.00125] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Accepted: 10/28/2019] [Indexed: 01/23/2023] Open
Abstract
The peroxisomal enzyme human D-amino acid oxidase (hDAAO) is attracting attention owing to its role in degrading D-serine, the main co-agonist of N-methyl D-aspartate receptors in brain, and its involvement in brain functions and diseases. Here, we focused on arginine 120, a residue located at the protein interface, 20 Å from the assumed second ligand-binding site, showing a different orientation of the side chain in the hDAAO-benzoate complex, and corresponding to Ser119 in rat DAAO, which is part of a putative nuclear translocation signal (NTS). By substituting Arg120 in hDAAO with a glutamate (to mimic the active NTS) or a leucine (to eliminate the positive charge) the protein conformation, thermal stability, and kinetic properties are slightly altered, while the dimeric structure and the ligand-binding properties are unchanged. The most relevant alteration in Arg120 variants is the strongest interaction with FAD. Nevertheless, the activity assayed at low D-serine and FAD concentrations (resembling physiological conditions) was quite similar for wild-type and Arg120 hDAAO variants. These results resemble the ones obtained substituting another residue located at the interface region (i.e., the W209R variant), indicating that substitutions at the monomer-monomer interface mainly affects the FAD binding in hDAAO. Indeed, U87 glioblastoma cells transiently transfected for hDAAO variants show that substitution of Arg120 favors mistargeting: the increase in cytosolic localization observed for the variants promotes nuclear targeting, especially for the R120E hDAAO, without affecting cell viability. Notably, mistargeting to the nucleus is an innate process as it is apparent for the wild-type hDAAO, too: whether such a process is related to specific pathologic processes is still unknown.
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Affiliation(s)
- Giulia Murtas
- Dipartimento di Biotecnologie e Scienze della Vita, Università degli Studi dell'Insubria, Varese, Italy
| | - Silvia Sacchi
- Dipartimento di Biotecnologie e Scienze della Vita, Università degli Studi dell'Insubria, Varese, Italy
| | - Loredano Pollegioni
- Dipartimento di Biotecnologie e Scienze della Vita, Università degli Studi dell'Insubria, Varese, Italy
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Selective demethylation of two CpG sites causes postnatal activation of the Dao gene and consequent removal of D-serine within the mouse cerebellum. Clin Epigenetics 2019; 11:149. [PMID: 31661019 PMCID: PMC6819446 DOI: 10.1186/s13148-019-0732-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Accepted: 08/29/2019] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND Programmed epigenetic modifications occurring at early postnatal brain developmental stages may have a long-lasting impact on brain function and complex behavior throughout life. Notably, it is now emerging that several genes that undergo perinatal changes in DNA methylation are associated with neuropsychiatric disorders. In this context, we envisaged that epigenetic modifications during the perinatal period may potentially drive essential changes in the genes regulating brain levels of critical neuromodulators such as D-serine and D-aspartate. Dysfunction of this fine regulation may contribute to the genesis of schizophrenia or other mental disorders, in which altered levels of D-amino acids are found. We recently demonstrated that Ddo, the D-aspartate degradation gene, is actively demethylated to ultimately reduce D-aspartate levels. However, the role of epigenetics as a mechanism driving the regulation of appropriate D-ser levels during brain development has been poorly investigated to date. METHODS We performed comprehensive ultradeep DNA methylation and hydroxymethylation profiling along with mRNA expression and HPLC-based D-amino acids level analyses of genes controlling the mammalian brain levels of D-serine and D-aspartate. DNA methylation changes occurring in specific cerebellar cell types were also investigated. We conducted high coverage targeted bisulfite sequencing by next-generation sequencing and single-molecule bioinformatic analysis. RESULTS We report consistent spatiotemporal modifications occurring at the Dao gene during neonatal development in a specific brain region (the cerebellum) and within specific cell types (astrocytes) for the first time. Dynamic demethylation at two specific CpG sites located just downstream of the transcription start site was sufficient to strongly activate the Dao gene, ultimately promoting the complete physiological degradation of cerebellar D-serine a few days after mouse birth. High amount of 5'-hydroxymethylcytosine, exclusively detected at relevant CpG sites, strongly evoked the occurrence of an active demethylation process. CONCLUSION The present investigation demonstrates that robust and selective demethylation of two CpG sites is associated with postnatal activation of the Dao gene and consequent removal of D-serine within the mouse cerebellum. A single-molecule methylation approach applied at the Dao locus promises to identify different cell-type compositions and functions in different brain areas and developmental stages.
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Liu H, Zhao M, Wang Z, Han Q, Wu H, Mao X, Wang Y. Involvement of d-amino acid oxidase in cerebral ischaemia induced by transient occlusion of the middle cerebral artery in mice. Br J Pharmacol 2019; 176:3336-3349. [PMID: 31309542 PMCID: PMC6692583 DOI: 10.1111/bph.14764] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Revised: 05/03/2019] [Accepted: 05/16/2019] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND AND PURPOSE d-Amino acid oxidase (DAAO) is a flavine adenine dinucleotide-containing flavoenzyme and specifically catalyses oxidative deamination of d-amino acids. This study aimed to explore the association between increased cerebral DAAO expression or enzymic activity and the development of cerebral ischaemia. EXPERIMENTAL APPROACH A mouse model of transient (90 min) middle cerebral artery occlusion (MCAO) was established, and western blotting, enzymic activity assay, and fluorescent immunostaining techniques were used. KEY RESULTS The expression and enzymic activity of DAAO increased over time in the cortical peri-infarct area of the mice subjected to transient MCAO. The DAAO was specifically expressed in astrocytes, and its double immunostaining with the astrocytic intracellular marker, glial fibrillary acidic protein, in the cortical peri-infarct area was up-regulated following ischaemic insult, with peak increase on Day 5 after MCAO. Single intravenous injection of the specific and potent DAAO inhibitor Compound SUN reduced the cerebral DAAO enzymic activity and attenuated neuronal infarction and neurobehavioural deficits with optimal improvement apparent immediately after the MCAO procedure. The neuroprotective effect was dose dependent, with ED50 values of 3.9-4.5 mg·kg-1 . Intracerebroventricular injection of the DAAO gene silencer siRNA/DAAO significantly reduced cerebral DAAO expression and attenuated MCAO-induced neuronal infarction and behavioural deficits. CONCLUSIONS AND IMPLICATIONS Our results, for the first time, demonstrated that increased cerebral astrocytic DAAO expression and enzymic activity were causally associated with the development of neuronal destruction following ischaemic insults, suggesting that targeting cerebral DAAO could be a potential approach for treatment of neurological conditions following cerebral ischaemia.
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Affiliation(s)
- Hao Liu
- King's LabShanghai Jiao Tong University School of PharmacyShanghaiChina
| | - Meng‐Jing Zhao
- King's LabShanghai Jiao Tong University School of PharmacyShanghaiChina
| | - Zi‐Ying Wang
- King's LabShanghai Jiao Tong University School of PharmacyShanghaiChina
| | - Qiao‐Qiao Han
- King's LabShanghai Jiao Tong University School of PharmacyShanghaiChina
| | - Hai‐Yun Wu
- King's LabShanghai Jiao Tong University School of PharmacyShanghaiChina
| | - Xiao‐fang Mao
- King's LabShanghai Jiao Tong University School of PharmacyShanghaiChina
| | - Yong‐Xiang Wang
- King's LabShanghai Jiao Tong University School of PharmacyShanghaiChina
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25
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The levels of the NMDA receptor co-agonist D-serine are reduced in the substantia nigra of MPTP-lesioned macaques and in the cerebrospinal fluid of Parkinson's disease patients. Sci Rep 2019; 9:8898. [PMID: 31222058 PMCID: PMC6586824 DOI: 10.1038/s41598-019-45419-1] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Accepted: 06/03/2019] [Indexed: 01/31/2023] Open
Abstract
Dysfunction of NMDA receptor (NMDAR)-mediated transmission is supposed to contribute to the motor and non-motor symptoms of Parkinson’s Disease (PD), and to L-DOPA-induced dyskinesia. Besides the main agonist L-glutamate, two other amino acids in the atypical D-configuration, D-serine and D-aspartate, activate NMDARs. In the present work, we investigated the effect of dopamine depletion on D-amino acids metabolism in the brain of MPTP-lesioned Macaca mulatta, and in the serum and cerebrospinal fluid of PD patients. We found that MPTP treatment increases D-aspartate and D-serine in the monkey putamen while L-DOPA rescues both D-amino acids levels. Conversely, dopaminergic denervation is associated with selective D-serine reduction in the substantia nigra. Such decrease suggests that the beneficial effect of D-serine adjuvant therapy previously reported in PD patients may derive from the normalization of endogenous D-serine levels and consequent improvement of nigrostriatal hypoglutamatergic transmission at glycine binding site. We also found reduced D-serine concentration in the cerebrospinal fluid of L-DOPA-free PD patients. These results further confirm the existence of deep interaction between dopaminergic and glutamatergic neurotransmission in PD and disclose a possible direct influence of D-amino acids variations in the changes of NMDAR transmission occurring under dopamine denervation and L-DOPA therapy.
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26
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Chen YC, Chou WH, Tsou HH, Fang CP, Liu TH, Tsao HH, Hsu WC, Weng YC, Wang Y, Liu YL. A Post-hoc Study of D-Amino Acid Oxidase in Blood as an Indicator of Post-stroke Dementia. Front Neurol 2019; 10:402. [PMID: 31105635 PMCID: PMC6497996 DOI: 10.3389/fneur.2019.00402] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Accepted: 04/03/2019] [Indexed: 02/03/2023] Open
Abstract
Stroke is an important risk factor for dementia. Epidemiological studies have indicated a high incidence of dementia in stroke patients. There is currently no effective biomarker for the diagnosis of post-stroke dementia (PSD). D-amino acid oxidase (DAO) is a flavin-dependent enzyme widely distributed in the central nervous system. DAO oxidizes D-amino acids, a process which generates neurotoxic hydrogen peroxide and leads to neurodegeneration. This study aimed to examine post-stroke plasma DAO levels as a biomarker for PSD. In total, 53 patients with PSD, 20 post-stroke patients without dementia (PSNoD), and 71 age- and gender-matched normal controls were recruited. Cognitive function was evaluated at more than 30 days post-stroke. Plasma DAO was measured using the enzyme-linked immunosorbent assay. White matter hyperintensity (WMH), a neuroimaging biomarker of cerebral small vessel diseases, was determined by magnetic resonance imaging. We found that plasma DAO levels were independently higher in PSD subjects than in PSNoD subjects or the controls and were correlated with the WMH load in stroke patients. Using an area under the curve (AUC)/receiver operating characteristic analysis, plasma DAO levels were significantly reliable for the diagnosis of PSD. The sensitivity and specificity of the optimal cut-off value of 321 ng/ml of plasma DAO for the diagnosis of PSD were 75 and 88.7%, respectively. In conclusion, our data support that plasma DAO levels were increased in PSD patients and correlated with brain WMH, independent of age, gender, hypertension, and renal function. Plasma DAO levels may therefore aid in PSD diagnosis.
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Affiliation(s)
- Yi-Chun Chen
- Department of Neurology, Chang Gung Memorial Hospital Linkou Medical Center and College of Medicine, Chang Gung University, Taoyuan, Taiwan.,Dementia Center, Chang Gung Memorial Hospital, Taoyuan, Taiwan
| | - Wen-Hai Chou
- Center for Neuropsychiatric Research, National Health Research Institutes, Miaoli, Taiwan
| | - Hsiao-Hui Tsou
- Division of Biostatistics and Bioinformatics, Institute of Population Health Sciences, National Health Research Institutes, Miaoli, Taiwan.,Graduate Institute of Biostatistics, China Medical University, Taichung, Taiwan
| | - Chiu-Ping Fang
- Center for Neuropsychiatric Research, National Health Research Institutes, Miaoli, Taiwan
| | - Tung-Hsia Liu
- Center for Neuropsychiatric Research, National Health Research Institutes, Miaoli, Taiwan
| | - Hsien-Hao Tsao
- Department of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Wen-Chuin Hsu
- Department of Neurology, Chang Gung Memorial Hospital Linkou Medical Center and College of Medicine, Chang Gung University, Taoyuan, Taiwan.,Dementia Center, Chang Gung Memorial Hospital, Taoyuan, Taiwan
| | - Yi-Chinn Weng
- Center for Neuropsychiatric Research, National Health Research Institutes, Miaoli, Taiwan
| | - Yun Wang
- Center for Neuropsychiatric Research, National Health Research Institutes, Miaoli, Taiwan
| | - Yu-Li Liu
- Center for Neuropsychiatric Research, National Health Research Institutes, Miaoli, Taiwan
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27
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Scott MR, Meador-Woodruff JH. Intracellular compartment-specific proteasome dysfunction in postmortem cortex in schizophrenia subjects. Mol Psychiatry 2019; 25:776-790. [PMID: 30683941 PMCID: PMC6658356 DOI: 10.1038/s41380-019-0359-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Revised: 12/19/2018] [Accepted: 01/11/2019] [Indexed: 12/19/2022]
Abstract
Protein homeostasis is an emerging component of schizophrenia (SZ) pathophysiology. Proteomic alterations in SZ are well-documented and changes in transcript expression are frequently not associated with changes in protein expression in SZ brain. The underlying mechanism driving these changes remains unknown, though altered expression of ubiquitin proteasome system (UPS) components have implicated protein degradation. Previous studies have been limited to protein and transcript expression, however, and do not directly test the function of the proteasome. To address this gap in knowledge, we measured enzymatic activity associated with the proteasome (chymotrypsin-, trypsin-, and caspase-like) in the superior temporal gyrus (STG) of 25 SZ and 25 comparison subjects using flourogenic substrates. As localization regulates which cellular processes the proteasome contributes to, we measured proteasome activity and subunit expression in fractions enriched for nucleus, cytosolic, and membrane compartments. SZ subjects had decreased trypsin-like activity in total homogenate. This finding was specific to the nucleus-enriched fraction and was not associated with changes in proteasome subunit expression. Interestingly, both chymotrypsin-like activity and protein expression of 19S RP subunits, which facilitate ubiquitin-dependent degradation, were decreased in the cytosol-enriched fraction of SZ subjects. Intracellular compartment-specific proteasome dysfunction implicates dysregulation of protein expression both through altered ubiquitin-dependent degradation of cytosolic proteins and regulation of protein synthesis due to degradation of transcription factors and transcription machinery in the nucleus. Together, these findings implicate proteasome dysfunction in SZ, which likely has a broad impact on the proteomic landscape and cellular function in the pathophysiology of this illness.
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Affiliation(s)
- Madeline R. Scott
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - James H. Meador-Woodruff
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham, Birmingham, AL 35294, USA
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28
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MacKay MAB, Kravtsenyuk M, Thomas R, Mitchell ND, Dursun SM, Baker GB. D-Serine: Potential Therapeutic Agent and/or Biomarker in Schizophrenia and Depression? Front Psychiatry 2019; 10:25. [PMID: 30787885 PMCID: PMC6372501 DOI: 10.3389/fpsyt.2019.00025] [Citation(s) in RCA: 80] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/28/2018] [Accepted: 01/15/2019] [Indexed: 11/17/2022] Open
Abstract
D-Serine is a potent co-agonist at the NMDA glutamate receptor and has been the object of many preclinical studies to ascertain the nature of its metabolism, its regional and cellular distribution in the brain, its physiological functions and its possible clinical relevance. The enzymes involved in its formation and catabolism are serine racemase (SR) and D-amino acid oxidase (DAAO), respectively, and manipulations of the activity of those enzymes have been useful in developing animal models of schizophrenia and in providing clues to the development of potential new antipsychotic strategies. Clinical studies have been conducted in schizophrenia patients to evaluate body fluid levels of D-serine and/or to use D-serine alone or in combination with antipsychotics to determine its effectiveness as a therapeutic agent. D-serine has also been used in combination with DAAO inhibitors in preclinical investigations, and interesting results have been obtained. Genetic studies and postmortem brain studies have also been conducted on D-serine and the enzymes involved in its metabolism. It is also of considerable interest that in recent years clinical and preclinical investigations have suggested that D-serine may also have antidepressant properties. Clinical studies have also shown that D-serine may be a biomarker for antidepressant response to ketamine. Relevant to both schizophrenia and depression, preclinical and clinical studies with D-serine indicate that it may be effective in reducing cognitive dysfunction.
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Affiliation(s)
- Mary-Anne B MacKay
- Neurochemical Research Unit and Bebensee Schizophrenia Research Unit, Department of Psychiatry, University of Alberta, Edmonton, AB, Canada.,Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada
| | - Maryana Kravtsenyuk
- Neurochemical Research Unit and Bebensee Schizophrenia Research Unit, Department of Psychiatry, University of Alberta, Edmonton, AB, Canada.,Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada
| | - Rejish Thomas
- Neurochemical Research Unit and Bebensee Schizophrenia Research Unit, Department of Psychiatry, University of Alberta, Edmonton, AB, Canada
| | - Nicholas D Mitchell
- Neurochemical Research Unit and Bebensee Schizophrenia Research Unit, Department of Psychiatry, University of Alberta, Edmonton, AB, Canada.,Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada
| | - Serdar M Dursun
- Neurochemical Research Unit and Bebensee Schizophrenia Research Unit, Department of Psychiatry, University of Alberta, Edmonton, AB, Canada.,Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada
| | - Glen B Baker
- Neurochemical Research Unit and Bebensee Schizophrenia Research Unit, Department of Psychiatry, University of Alberta, Edmonton, AB, Canada.,Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada
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29
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Kim R, Healey KL, Sepulveda-Orengo MT, Reissner KJ. Astroglial correlates of neuropsychiatric disease: From astrocytopathy to astrogliosis. Prog Neuropsychopharmacol Biol Psychiatry 2018; 87:126-146. [PMID: 28989099 PMCID: PMC5889368 DOI: 10.1016/j.pnpbp.2017.10.002] [Citation(s) in RCA: 85] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Revised: 09/24/2017] [Accepted: 10/04/2017] [Indexed: 01/22/2023]
Abstract
Complex roles for astrocytes in health and disease continue to emerge, highlighting this class of cells as integral to function and dysfunction of the nervous system. In particular, escalating evidence strongly implicates a range of changes in astrocyte structure and function associated with neuropsychiatric diseases including major depressive disorder, schizophrenia, and addiction. These changes can range from astrocytopathy, degeneration, and loss of function, to astrogliosis and hypertrophy, and can be either adaptive or maladaptive. Evidence from the literature indicates a myriad of changes observed in astrocytes from both human postmortem studies as well as preclinical animal models, including changes in expression of glial fibrillary protein, as well as changes in astrocyte morphology and astrocyte-mediated regulation of synaptic function. In this review, we seek to provide a comprehensive assessment of these findings and consequently evidence for common themes regarding adaptations in astrocytes associated with neuropsychiatric disease. While results are mixed across conditions and models, general findings indicate decreased astrocyte cellular features and gene expression in depression, chronic stress and anxiety, but increased inflammation in schizophrenia. Changes also vary widely in response to different drugs of abuse, with evidence reflective of features of astrocytopathy to astrogliosis, varying across drug classes, route of administration and length of withdrawal.
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Affiliation(s)
- Ronald Kim
- Department of Psychology and Neuroscience, CB 3270, UNC Chapel Hill, Chapel Hill, NC 27599, United States
| | - Kati L Healey
- Department of Psychology and Neuroscience, CB 3270, UNC Chapel Hill, Chapel Hill, NC 27599, United States
| | - Marian T Sepulveda-Orengo
- Department of Psychology and Neuroscience, CB 3270, UNC Chapel Hill, Chapel Hill, NC 27599, United States
| | - Kathryn J Reissner
- Department of Psychology and Neuroscience, CB 3270, UNC Chapel Hill, Chapel Hill, NC 27599, United States..
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30
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Stimulation of N-methyl-D-aspartate receptors by exogenous and endogenous ligands improves outcome of brain injury. Curr Opin Neurol 2018; 31:687-692. [DOI: 10.1097/wco.0000000000000612] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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31
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Pollegioni L, Sacchi S, Murtas G. Human D-Amino Acid Oxidase: Structure, Function, and Regulation. Front Mol Biosci 2018; 5:107. [PMID: 30547037 PMCID: PMC6279847 DOI: 10.3389/fmolb.2018.00107] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2018] [Accepted: 11/12/2018] [Indexed: 12/11/2022] Open
Abstract
D-Amino acid oxidase (DAAO) is an FAD-containing flavoenzyme that catalyzes with absolute stereoselectivity the oxidative deamination of all natural D-amino acids, the only exception being the acidic ones. This flavoenzyme plays different roles during evolution and in different tissues in humans. Its three-dimensional structure is well conserved during evolution: minute changes are responsible for the functional differences between enzymes from microorganism sources and those from humans. In recent years several investigations focused on human DAAO, mainly because of its role in degrading the neuromodulator D-serine in the central nervous system. D-Serine is the main coagonist of N-methyl D-aspartate receptors, i.e., excitatory amino acid receptors critically involved in main brain functions and pathologic conditions. Human DAAO possesses a weak interaction with the FAD cofactor; thus, in vivo it should be largely present in the inactive, apoprotein form. Binding of active-site ligands and the substrate stabilizes flavin binding, thus pushing the acquisition of catalytic competence. Interestingly, the kinetic efficiency of the enzyme on D-serine is very low. Human DAAO interacts with various proteins, in this way modulating its activity, targeting, and cell stability. The known properties of human DAAO suggest that its activity must be finely tuned to fulfill a main physiological function such as the control of D-serine levels in the brain. At present, studies are focusing on the epigenetic modulation of human DAAO expression and the role of post-translational modifications on its main biochemical properties at the cellular level.
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Affiliation(s)
- Loredano Pollegioni
- Dipartimento di Biotecnologie e Scienze della Vita, Università degli Studi dell'Insubria, Varese, Italy
| | - Silvia Sacchi
- Dipartimento di Biotecnologie e Scienze della Vita, Università degli Studi dell'Insubria, Varese, Italy
| | - Giulia Murtas
- Dipartimento di Biotecnologie e Scienze della Vita, Università degli Studi dell'Insubria, Varese, Italy
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32
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Billard JM. Changes in Serine Racemase-Dependent Modulation of NMDA Receptor: Impact on Physiological and Pathological Brain Aging. Front Mol Biosci 2018; 5:106. [PMID: 30555832 PMCID: PMC6282039 DOI: 10.3389/fmolb.2018.00106] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Accepted: 11/09/2018] [Indexed: 02/02/2023] Open
Abstract
The N-methyl-D-Aspartate glutamate receptors (NMDARs) are pivotal for the functional and morphological plasticity that are required in neuronal networks for efficient brain activities and notably for cognitive-related abilities. Because NMDARs are heterogeneous in subunit composition and associated with multiple functional regulatory sites, their efficacy is under the tonic influence of numerous allosteric modulations, whose dysfunction generally represents the first step generating pathological states. Among the enzymatic candidates, serine racemase (SR) has recently gathered an increasing interest considering that it tightly regulates the production of d-serine, an amino acid now viewed as the main endogenous co-agonist necessary for NMDAR activation. Nowadays, SR deregulation is associated with a wide range of neurological and psychiatric diseases including schizophrenia, amyotrophic lateral sclerosis, and depression. This review aims at compelling the most recent experimental evidences indicating that changes in SR-related modulation of NMDARs also govern opposite functional dysfunctions in physiological and pathological (Alzheimer's disease) aging that finally results in memory disabilities in both cases. It also highlights SR as a relevant alternative target for new pharmacological strategies aimed at preventing functional alterations and cognitive impairments linked to the aging process.
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33
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Popiolek M, Tierney B, Steyn SJ, DeVivo M. Lack of Effect of Sodium Benzoate at Reported Clinical Therapeutic Concentration on d-Alanine Metabolism in Dogs. ACS Chem Neurosci 2018; 9:2832-2837. [PMID: 29893546 DOI: 10.1021/acschemneuro.8b00229] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Cognitive decline and psychosis have been hypothesized to be mediated by N-methyl-d-aspartate receptor (NMDAR) hypofunction. Consistent with this hypothesis, chronic treatment with d-alanine, a coagonist at the glycine site of the NMDAR, leads to an improvement of positive and cognitive symptoms in schizophrenic patients. d-alanine is oxidized by d-amino acid oxidase (DAAO); thus, an inhibitor of DAAO would be expected to enhance d-alanine levels and likewise lead to desirable clinical outcomes. Sodium benzoate, on the basis of d-amino acid inhibition, was observed to display beneficial clinical effects in schizophrenic and Alzheimer's patients. However, in the clinical pilot studies using sodium benzoate, d-amino acids were not quantified to verify that sodium benzoate's efficacy was mediated through DAAO inhibition. In this study, d-alanine content was monitored in cerebral spinal fluid (CSF) of dogs treated with daily injections of d-alanine (30 mg/kg) alone and in combination with sodium benzoate (30 mg/kg) for seven consecutive days. We reasoned that the cerebral spinal fluid d-alanine quantity is reflective of the brain d-alanine levels and it would increase as a consequence of DAAO inhibition with sodium benzoate. We found that d-alanine treatment lead to maximal concentration of 7.51 μM CSF d-alanine level; however, coadministration of sodium benzoate and d-alanine did not change CSF d-alanine level beyond that of d-alanine treatment alone. As a consequence, we conclude that clinical efficacy associated with chronic administration of sodium benzoate in schizophrenic and Alzheimer's patients is likely not mediated through inhibition of DAAO.
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34
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Harrison PJ. D-Amino Acid Oxidase Inhibition: A New Glutamate Twist for Clozapine Augmentation in Schizophrenia? Biol Psychiatry 2018; 84:396-398. [PMID: 30165950 DOI: 10.1016/j.biopsych.2018.06.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Revised: 06/04/2018] [Accepted: 06/04/2018] [Indexed: 01/18/2023]
Affiliation(s)
- Paul J Harrison
- Department of Psychiatry, University of Oxford, and Oxford Health NHS Foundation Trust, Warneford Hospital, Oxford, United Kingdom.
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35
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Keller S, Punzo D, Cuomo M, Affinito O, Coretti L, Sacchi S, Florio E, Lembo F, Carella M, Copetti M, Cocozza S, Balu DT, Errico F, Usiello A, Chiariotti L. DNA methylation landscape of the genes regulating D-serine and D-aspartate metabolism in post-mortem brain from controls and subjects with schizophrenia. Sci Rep 2018; 8:10163. [PMID: 29976992 PMCID: PMC6033866 DOI: 10.1038/s41598-018-28332-x] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Accepted: 06/21/2018] [Indexed: 01/24/2023] Open
Abstract
The spatio-temporal regulation of genes involved in the synthesis and degradation of D-serine and D-aspartate such as serine racemase (SR), D-amino acid oxidase (DAO), G72 and D-aspartate oxidase (DDO), play pivotal roles in determining the correct levels of these D-amino acids in the human brain. Here we provide a comprehensive analysis of mRNA expression and DNA methylation status of these genes in post-mortem samples from hippocampus, dorsolateral prefrontal cortex, and cerebellum from patients with schizophrenia and non-psychiatric controls. DNA methylation analysis was performed at an ultradeep level, measuring individual epialleles frequency by single molecule approach. Differential CpG methylation and expression was detected across different brain regions, although no significant correlations were found with diagnosis. G72 showed the highest CpG and non-CpG methylation degree, which may explain the repression of G72 transcription in the brain regions considered here. Conversely, in line with the sustained SR mRNA expression in the analyzed areas, very low methylation levels were detected at this gene’s regulatory regions. Furthermore, for DAO and DDO, our single-molecule methylation approach demonstrated that analysis of epiallele distribution was able to detect differences in DNA methylation representing area-specific methylation signatures, which are likely not detectable with targeted or genome-wide classic methylation analyses.
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Affiliation(s)
- Simona Keller
- Department of Molecular Medicine and Medical Biotechnology, University of Naples "Federico II", 80131, Naples, Italy.,Endocrinology and Molecular Oncology Institute (I.E.O.S.), National Research Council (C.N.R.), 80131, Naples, Italy
| | - Daniela Punzo
- Laboratory of Behavioural Neuroscience, Ceinge Biotecnologie Avanzate, 80145, Naples, Italy.,Department of Environmental, Biological and Pharmaceutical Sciences and Technologies, Università degli Studi della Campania "Luigi Vanvitelli", 81100, Caserta, Italy
| | - Mariella Cuomo
- Department of Molecular Medicine and Medical Biotechnology, University of Naples "Federico II", 80131, Naples, Italy
| | - Ornella Affinito
- Department of Molecular Medicine and Medical Biotechnology, University of Naples "Federico II", 80131, Naples, Italy.,Endocrinology and Molecular Oncology Institute (I.E.O.S.), National Research Council (C.N.R.), 80131, Naples, Italy
| | - Lorena Coretti
- Department of Molecular Medicine and Medical Biotechnology, University of Naples "Federico II", 80131, Naples, Italy.,Endocrinology and Molecular Oncology Institute (I.E.O.S.), National Research Council (C.N.R.), 80131, Naples, Italy
| | - Silvia Sacchi
- Dipartimento di Biotecnologie e Scienze della Vita, Università degli Studi dell'Insubria, 21100, Varese, Italy.,The Protein Factory, Politecnico di Milano and Università degli studi dell'Insubria, 20131, Milano, Italy
| | - Ermanno Florio
- Department of Molecular Medicine and Medical Biotechnology, University of Naples "Federico II", 80131, Naples, Italy.,Endocrinology and Molecular Oncology Institute (I.E.O.S.), National Research Council (C.N.R.), 80131, Naples, Italy.,Department of Medicine, University of California, San Diego UCSD, La Jolla, 95000, CA, USA
| | - Francesca Lembo
- Department of Molecular Medicine and Medical Biotechnology, University of Naples "Federico II", 80131, Naples, Italy
| | - Massimo Carella
- Medical Genetics Unit, IRCCS Casa Sollievo della Sofferenza, 71013, San Giovanni Rotondo, FG, Italy
| | - Massimiliano Copetti
- Unit of Biostatistics, IRCCS Casa Sollievo della Sofferenza, 71013, San Giovanni Rotondo, FG, Italy
| | - Sergio Cocozza
- Department of Molecular Medicine and Medical Biotechnology, University of Naples "Federico II", 80131, Naples, Italy.,Endocrinology and Molecular Oncology Institute (I.E.O.S.), National Research Council (C.N.R.), 80131, Naples, Italy
| | - Darrick T Balu
- Department of Psychiatry, Harvard Medical School, Boston, 02115, MA, USA.,Translational Psychiatry Laboratory, McLean Hospital, Belmont, 02478, MA, USA
| | - Francesco Errico
- Laboratory of Behavioural Neuroscience, Ceinge Biotecnologie Avanzate, 80145, Naples, Italy.,Department of Agricultural Sciences, University of Naples "Federico II", 80055, Portici, Italy
| | - Alessandro Usiello
- Laboratory of Behavioural Neuroscience, Ceinge Biotecnologie Avanzate, 80145, Naples, Italy. .,Department of Environmental, Biological and Pharmaceutical Sciences and Technologies, Università degli Studi della Campania "Luigi Vanvitelli", 81100, Caserta, Italy. .,Medical Genetics Unit, IRCCS Casa Sollievo della Sofferenza, 71013, San Giovanni Rotondo, FG, Italy.
| | - Lorenzo Chiariotti
- Department of Molecular Medicine and Medical Biotechnology, University of Naples "Federico II", 80131, Naples, Italy. .,Endocrinology and Molecular Oncology Institute (I.E.O.S.), National Research Council (C.N.R.), 80131, Naples, Italy.
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Sacchi S, Cappelletti P, Murtas G. Biochemical Properties of Human D-amino Acid Oxidase Variants and Their Potential Significance in Pathologies. Front Mol Biosci 2018; 5:55. [PMID: 29946548 PMCID: PMC6005901 DOI: 10.3389/fmolb.2018.00055] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Accepted: 05/23/2018] [Indexed: 12/11/2022] Open
Abstract
The stereoselective flavoenzyme D-amino acid oxidase (DAAO) catalyzes the oxidative deamination of neutral and polar D-amino acids producing the corresponding α-keto acids, ammonia, and hydrogen peroxide. Despite its peculiar and atypical substrates, DAAO is widespread expressed in most eukaryotic organisms. In mammals (and humans in particular), DAAO is involved in relevant physiological processes ranging from D-amino acid detoxification in kidney to neurotransmission in the central nervous system, where DAAO is responsible of the catabolism of D-serine, a key endogenous co-agonist of N-methyl-D-aspartate receptors. Recently, structural and functional studies have brought to the fore the distinctive biochemical properties of human DAAO (hDAAO). It appears to have evolved to allow a strict regulation of its activity, so that the enzyme can finely control the concentration of substrates (such as D-serine in the brain) without yielding to an excessive production of hydrogen peroxide, a potentially toxic reactive oxygen species (ROS). Indeed, dysregulation in D-serine metabolism, likely resulting from altered levels of hDAAO expression and activity, has been implicated in several pathologies, ranging from renal disease to neurological, neurodegenerative, and psychiatric disorders. Only one mutation in DAO gene was unequivocally associated to a human disease. However, several single nucleotide polymorphisms (SNPs) are reported in the database and the biochemical characterization of the corresponding recombinant hDAAO variants is of great interest for investigating the effect of mutations. Here we reviewed recently published data focusing on the modifications of the structural and functional properties induced by amino acid substitutions encoded by confirmed SNPs and on their effect on D-serine cellular levels. The potential significance of the different hDAAO variants in human pathologies will be also discussed.
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Affiliation(s)
- Silvia Sacchi
- Dipartimento di Biotecnologie e Scienze della Vita, Università degli Studi dell'Insubria, Varese, Italy.,The Protein Factory, Politecnico di Milano and Università degli Studi dell'Insubria, Milan, Italy
| | - Pamela Cappelletti
- Dipartimento di Biotecnologie e Scienze della Vita, Università degli Studi dell'Insubria, Varese, Italy.,The Protein Factory, Politecnico di Milano and Università degli Studi dell'Insubria, Milan, Italy
| | - Giulia Murtas
- Dipartimento di Biotecnologie e Scienze della Vita, Università degli Studi dell'Insubria, Varese, Italy
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Relevance of Alternative Routes of Kynurenic Acid Production in the Brain. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2018; 2018:5272741. [PMID: 29977455 PMCID: PMC5994304 DOI: 10.1155/2018/5272741] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Accepted: 04/24/2018] [Indexed: 01/24/2023]
Abstract
The catabolism of tryptophan has gained great importance in recent years due to the fact that the metabolites produced during this process, with neuroactive and redox properties, are involved in physiological and pathological events. One of these metabolites is kynurenic acid (KYNA), which is considered as a neuromodulator since it can interact with NMDA, nicotinic, and GPR35 receptors among others, modulating the release of neurotransmitters as glutamate, dopamine, and acetylcholine. Kynureninate production is attributed to kynurenine aminotransferases. However, in some physiological and pathological conditions, its high production cannot be explained just with kynurenine aminotransferases. This review focuses on the alternative mechanism whereby KYNA can be produced, either from D-amino acids or by means of other enzymes as D-amino acid oxidase or by the participation of free radicals. It is important to mention that an increase in KYNA levels in processes as brain development, aging, neurodegenerative diseases, and psychiatric disorders, which share common factors as oxidative stress, inflammation, immune response activation, and participation of gut microbiota that can also be related with the alternative routes of KYNA production, has been observed.
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Liraz-Zaltsman S, Slusher B, Atrakchi-Baranes D, Rosenblatt K, Friedman Levi Y, Kesner E, Silva AJ, Biegon A, Shohami E. Enhancement of Brain d-Serine Mediates Recovery of Cognitive Function after Traumatic Brain Injury. J Neurotrauma 2018; 35:1667-1680. [PMID: 29648983 DOI: 10.1089/neu.2017.5561] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Cognitive deficits, especially memory loss, are common and devastating neuropsychiatric sequelae of traumatic brain injury (TBI). The deficits may persist for years and may be accompanied by increased risk of developing early- onset dementia. Past attempts to reverse the neuropathological effects of brain injury with glutamate-N-methyl-d-aspartate (NMDA) antagonists failed to show any benefits or worsened the outcome, suggesting that activation, rather than blockage, of the NMDA receptor (NMDAR) may be useful in the subacute period after TBI and stroke. Activation of the NMDAR requires occupation of the glycine-modulatory site by co-agonists to achieve its synaptic functions. Glycine and d-serine are endogenous ligands/co-agonists of synaptic NMDARs in many areas of the mature brain. The aim of the present study was to evaluate the effect of 6-chlorobenzo(d)isoxazol-3-ol (CBIO), an inhibitor of D-amino acid oxidase (DAAO), which degrades d-serine, on cognitive outcome in a mouse model of TBI. Because treating TBI animals with CBIO elevates the endogenous levels of d-serine, we compared this novel treatment with treatment by exogenous d-serine alone and combined with CBIO. The results show that a single treatment (24 h post-injury) with CBIO in the mouse model of closed head injury significantly improves cognitive and motor function, and decreases lesion volume and the inflammatory response. Moreover, the compound proved to be neuroprotective, as the hippocampal volume and the number of neurons in hippocampal regions increased. Treatment with CBIO boosted the NR1 and phospho- NR1 subunits of the NMDAR and affected the CREB, phospho-CREB, and brain-derived neurotropic factor (BDNF) pathways. These findings render CBIO a promising, novel treatment for cognitive impairment following TBI.
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Affiliation(s)
- Sigal Liraz-Zaltsman
- 1 The Joseph Sagol Neuroscience Center, Sheba Medical Center , Tel Hashomer, Israel .,2 Department of Pharmacology, Institute for Drug Research, Hebrew University , Jerusalem, Israel
| | - Barbara Slusher
- 3 Johns Hopkin Drug Discovery and Department of Neurology, Johns Hopkins School of Medicine , Baltimore, Maryland
| | | | | | - Yael Friedman Levi
- 2 Department of Pharmacology, Institute for Drug Research, Hebrew University , Jerusalem, Israel
| | - Efrat Kesner
- 2 Department of Pharmacology, Institute for Drug Research, Hebrew University , Jerusalem, Israel
| | - Alcino J Silva
- 5 Integrative Center for Learning and Memory Brain Research Institute, University of California , Los Angeles, California
| | - Anat Biegon
- 6 Department of Radiology and Neurology, Stony Brook University School of Medicine , Stony Brook, New York
| | - Esther Shohami
- 2 Department of Pharmacology, Institute for Drug Research, Hebrew University , Jerusalem, Israel
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Li W, Talukder M, Sun XT, Zhang C, Li XN, Ge J, Li JL. Selenoprotein W as a molecular target of d-amino acid oxidase is regulated by d-amino acid in chicken neurons. Metallomics 2018; 10:751-758. [DOI: 10.1039/c8mt00042e] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Selenoprotein W (SelW), an important member of the avian selenoprotein family, can combine with d-amino acid oxidase (DAAO). Selenium (Se) can inhibit the toxicity of d-serine and maybe has a detoxifying ability by increasing the expression of SelW and decreasing the activity of DAAO.
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Affiliation(s)
- Wei Li
- College of Veterinary Medicine
- Northeast Agricultural University
- Harbin
- P. R. China
| | - Milton Talukder
- College of Veterinary Medicine
- Northeast Agricultural University
- Harbin
- P. R. China
- Department of Physiology and Pharmacology
| | - Xue-Tong Sun
- College of Veterinary Medicine
- Northeast Agricultural University
- Harbin
- P. R. China
| | - Cong Zhang
- College of Veterinary Medicine
- Northeast Agricultural University
- Harbin
- P. R. China
| | - Xue-Nan Li
- College of Veterinary Medicine
- Northeast Agricultural University
- Harbin
- P. R. China
| | - Jing Ge
- College of Veterinary Medicine
- Northeast Agricultural University
- Harbin
- P. R. China
| | - Jin-Long Li
- College of Veterinary Medicine
- Northeast Agricultural University
- Harbin
- P. R. China
- Heilongjiang Key Laboratory for Laboratory Animals and Comparative Medicine
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40
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Murtas G, Caldinelli L, Cappelletti P, Sacchi S, Pollegioni L. Human d-amino acid oxidase: The inactive G183R variant. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2017; 1866:822-830. [PMID: 29274788 DOI: 10.1016/j.bbapap.2017.12.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Revised: 12/12/2017] [Accepted: 12/14/2017] [Indexed: 12/11/2022]
Abstract
In the brain, the enzyme d-amino acid oxidase (DAAO) catalyzes the oxidative deamination of d-serine, a main positive modulator of the N-methyl-d-aspartate subtype of glutamate receptors (NMDAR). Dysregulation in d-serine signaling is implicated in the NMDAR dysfunctions observed in various brain diseases, such as amyotrophic lateral sclerosis, Alzheimer's disease, schizophrenia. A strain of ddY mice lacking DAAO activity due to the G181R substitution (DAAOG181R mice) and exhibiting increased d-serine concentration as compared to wild-type mice shows altered pain response, improved adaptative learning and cognitive functions, and larger hippocampal long-term potentiation. In past years, this mice line has been used to shed light on physiological and pathological brain functions related to NMDAR. Here, we decided to introduce the corresponding substitution in human DAAO (hDAAO). The recombinant G183R hDAAO is produced as an inactive apoprotein: the substitution alters the protein conformation that negatively affects the ability to bind the flavin cofactor in the orientation required for hydride-transfer during catalysis. At the cellular level, the overexpressed G183R hDAAO is not fully targeted to peroxisomes, forms protein aggregates showing a strong colocalization with ubiquitin, and significantly (7-fold) increases both the d-serine cellular concentration and the D/(D+L)-serine ratio. Taken together, our investigation warrants caution in using DAAOG181R mice: the abolition of enzymatic activity is coupled to DAAO aggregation, a central process in different pathological conditions. The effect due to G181R substitution in DAAO could be misleading: the effects due to impairment of d-serine degradation overlap with those related to aggregates accumulation.
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Affiliation(s)
- Giulia Murtas
- Dipartimento di Biotecnologie e Scienze della Vita, Università degli studi dell'Insubria, via J. H. Dunant 3, 21100 Varese, Italy.
| | - Laura Caldinelli
- Dipartimento di Biotecnologie e Scienze della Vita, Università degli studi dell'Insubria, via J. H. Dunant 3, 21100 Varese, Italy; The Protein Factory, Politecnico di Milano and Università degli studi dell'Insubria, via Mancinelli 7, 20131 Milan, Italy
| | - Pamela Cappelletti
- Dipartimento di Biotecnologie e Scienze della Vita, Università degli studi dell'Insubria, via J. H. Dunant 3, 21100 Varese, Italy; The Protein Factory, Politecnico di Milano and Università degli studi dell'Insubria, via Mancinelli 7, 20131 Milan, Italy
| | - Silvia Sacchi
- Dipartimento di Biotecnologie e Scienze della Vita, Università degli studi dell'Insubria, via J. H. Dunant 3, 21100 Varese, Italy; The Protein Factory, Politecnico di Milano and Università degli studi dell'Insubria, via Mancinelli 7, 20131 Milan, Italy
| | - Loredano Pollegioni
- Dipartimento di Biotecnologie e Scienze della Vita, Università degli studi dell'Insubria, via J. H. Dunant 3, 21100 Varese, Italy; The Protein Factory, Politecnico di Milano and Università degli studi dell'Insubria, via Mancinelli 7, 20131 Milan, Italy
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41
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Onozato M, Nakazawa H, Ishimaru K, Nagashima C, Fukumoto M, Hakariya H, Sakamoto T, Ichiba H, Fukushima T. Alteration in plasma and striatal levels of d-serine after d-serine administration with or without nicergoline: An in vivo microdialysis study. Heliyon 2017; 3:e00399. [PMID: 28924620 PMCID: PMC5591394 DOI: 10.1016/j.heliyon.2017.e00399] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Revised: 05/10/2017] [Accepted: 08/29/2017] [Indexed: 12/18/2022] Open
Abstract
Aims d-Serine (d-Ser), a co-agonist of N-methyl-d-aspartate receptor (NMDAR), is effective for treating schizophrenia. The present study investigated changes in plasma and striatal d-Ser levels in Sprague-Dawley (SD) rats after intraperitoneal d-Ser administration alone or together with nicergoline (Nic), a commercial cerebral ameliorating drug, using in vivo microdialysis (MD) to explore the function of Nic. Main methods Phosphate-buffered saline (PBS) or Nic (0, 1.0, or 3.0 mg/kg) followed by d-Ser (5.0, 10.0, 20.0, and 50.0 mg/kg for PBS or 20.0 mg/kg for Nic) was administered intraperitoneally to male SD rats, and the profiles of d-Ser levels in plasma and striatal MD samples were examined by high-performance liquid chromatography (HPLC) with fluorescence detection. The area under the curve (AUC) for the MD and plasma samples was also calculated and statistically compared among groups. Key findings AUC values of d-Ser increased in a d-Ser dose-dependent manner in plasma samples, while a proportional increase in the AUC values of striatal MD samples was only observed in d-Ser doses up to 20 mg/kg. The Nic co-administered group showed a significant increase in the AUC of plasma d-Ser in a Nic dose-dependent manner, but the AUC in striatal d-Ser significantly decreased with increasing Nic doses suggesting that Nic may prevent excess d-Ser from penetrating the central nervous system (CNS). Significance Nic may prevent an excessive distribution of exogenous d-Ser, such as that from a dietary origin, into the CNS by suppressing excitatory neurotransmission through NMDAR.
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Affiliation(s)
- Mayu Onozato
- Faculty of Pharmaceutical Sciences, Toho University, 2-2-1 Miyama, Funabashi-shi, Chiba 274-8510, Japan
| | - Hiromi Nakazawa
- Faculty of Pharmaceutical Sciences, Toho University, 2-2-1 Miyama, Funabashi-shi, Chiba 274-8510, Japan
| | - Katsuyuki Ishimaru
- Faculty of Pharmaceutical Sciences, Toho University, 2-2-1 Miyama, Funabashi-shi, Chiba 274-8510, Japan
| | - Chihiro Nagashima
- Faculty of Pharmaceutical Sciences, Toho University, 2-2-1 Miyama, Funabashi-shi, Chiba 274-8510, Japan
| | - Minori Fukumoto
- Faculty of Pharmaceutical Sciences, Toho University, 2-2-1 Miyama, Funabashi-shi, Chiba 274-8510, Japan
| | - Hitomi Hakariya
- Faculty of Pharmaceutical Sciences, Toho University, 2-2-1 Miyama, Funabashi-shi, Chiba 274-8510, Japan
| | - Tatsuya Sakamoto
- Faculty of Pharmaceutical Sciences, Toho University, 2-2-1 Miyama, Funabashi-shi, Chiba 274-8510, Japan
| | - Hideaki Ichiba
- Faculty of Pharmaceutical Sciences, Toho University, 2-2-1 Miyama, Funabashi-shi, Chiba 274-8510, Japan
| | - Takeshi Fukushima
- Faculty of Pharmaceutical Sciences, Toho University, 2-2-1 Miyama, Funabashi-shi, Chiba 274-8510, Japan
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42
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Understanding renal nuclear protein accumulation: an in vitro approach to explain an in vivo phenomenon. Arch Toxicol 2017; 91:3599-3611. [PMID: 28451739 DOI: 10.1007/s00204-017-1970-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Accepted: 04/19/2017] [Indexed: 01/01/2023]
Abstract
Proper subcellular trafficking is essential to prevent protein mislocalization and aggregation. Transport of the peroxisomal enzyme D-amino acid oxidase (DAAO) appears dysregulated by specific pharmaceuticals, e.g., the anti-overactive bladder drug propiverine or a norepinephrine/serotonin reuptake inhibitor (NSRI), resulting in massive cytosolic and nuclear accumulations in rat kidney. To assess the underlying molecular mechanism of the latter, we aimed to characterize the nature of peroxisomal and cyto-nuclear shuttling of human and rat DAAO overexpressed in three cell lines using confocal microscopy. Indeed, interference with peroxisomal transport via deletion of the PTS1 signal or PEX5 knockdown resulted in induced nuclear DAAO localization. Having demonstrated the absence of active nuclear import and employing variably sized mCherry- and/or EYFP-fusion proteins of DAAO and catalase, we showed that peroxisomal proteins ≤134 kDa can passively diffuse into mammalian cell nuclei-thereby contradicting the often-cited 40 kDa diffusion limit. Moreover, their inherent nuclear presence and nuclear accumulation subsequent to proteasome inhibition or abrogated peroxisomal transport suggests that nuclear localization is a characteristic in the lifecycle of peroxisomal proteins. Based on this molecular trafficking analysis, we suggest that pharmaceuticals like propiverine or an NSRI may interfere with peroxisomal protein targeting and import, consequently resulting in massive nuclear protein accumulation in vivo.
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43
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Decreased free d-aspartate levels are linked to enhanced d-aspartate oxidase activity in the dorsolateral prefrontal cortex of schizophrenia patients. NPJ SCHIZOPHRENIA 2017; 3:16. [PMID: 28560262 PMCID: PMC5441530 DOI: 10.1038/s41537-017-0015-7] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Revised: 02/10/2017] [Accepted: 02/22/2017] [Indexed: 01/02/2023]
Abstract
It is long acknowledged that the N-methyl d-aspartate receptor co-agonist, d-serine, plays a crucial role in several N-methyl d-aspartate receptor-mediated physiological and pathological processes, including schizophrenia. Besides d-serine, another free d-amino acid, d-aspartate, is involved in the activation of N-methyl d-aspartate receptors acting as an agonist of this receptor subclass, and is abundantly detected in the developing human brain. Based on the hypothesis of N-methyl d-aspartate receptor hypofunction in the pathophysiology of schizophrenia and considering the ability of d-aspartate and d-serine to stimulate N-methyl d-aspartate receptor-dependent transmission, in the present work we assessed the concentration of these two d-amino acids in the post-mortem dorsolateral prefrontal cortex and hippocampus of patients with schizophrenia and healthy subjects. Moreover, in this cohort of post-mortem brain samples we investigated the spatiotemporal variations of d-aspartate and d-serine. Consistent with previous work, we found that d-aspartate content was selectively decreased by around 30% in the dorsolateral prefrontal cortex, but not in the hippocampus, of schizophrenia-affected patients, compared to healthy subjects. Interestingly, such selective reduction was associated to greater (around 25%) cortical activity of the enzyme responsible for d-aspartate catabolism, d-aspartate oxidase. Conversely, no significant changes were found in the methylation state and transcription of DDO gene in patients with schizophrenia, compared to control individuals, as well as in the expression levels of serine racemase, the major enzyme responsible for d-serine biosynthesis, which also catalyzes aspartate racemization. These results reveal the potential involvement of altered d-aspartate metabolism in the dorsolateral prefrontal cortex as a factor contributing to dysfunctional N-methyl d-aspartate receptor-mediated transmission in schizophrenia. Altered metabolism of an amino acid activator of ion channels in the brain could explain dysfunctional nerve signaling in schizophrenia. Researchers in Italy led by Alessandro Usiello from Ceinge Biotecnologie Avanzate and Loredano Pollegioni from the University of Insubria measured the levels of two amino acids—D-aspartate and D-serine—in post-mortem tissues taken from two brain regions of patients with and without schizophrenia. Both amino acids activate the N-methyl D-aspartate receptor, which is known to be less active in people with schizophrenia. The researchers found a mild increase in D-serine levels but a major decrease in D-aspartate in the schizophrenia patients’ dorsolateral prefrontal cortex (DLPFC), a memory and reasoning part of the brain, but not in the hippocampus. They also documented a greater activity of the enzyme responsible for D-aspartate breakdown in the DLPFC.
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44
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Jagannath V, Marinova Z, Monoranu CM, Walitza S, Grünblatt E. Expression of D-Amino Acid Oxidase ( DAO/ DAAO) and D-Amino Acid Oxidase Activator ( DAOA/G72) during Development and Aging in the Human Post-mortem Brain. Front Neuroanat 2017; 11:31. [PMID: 28428746 PMCID: PMC5382383 DOI: 10.3389/fnana.2017.00031] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2016] [Accepted: 03/24/2017] [Indexed: 12/30/2022] Open
Abstract
In the brain, D-amino acid oxidase (DAO/DAAO) mainly oxidizes D-serine, a co-agonist of the N-methyl-D-aspartate (NMDA) receptors. Thus, DAO can regulate the function of NMDA receptors via D-serine breakdown. Furthermore, DAO activator (DAOA)/G72 has been reported as both DAOA and repressor. The co-expression of DAO and DAOA genes and proteins in the human brain is not yet elucidated. The aim of this study was to understand the regional and age span distribution of DAO and DAOA (mRNA and protein) in a concomitant manner. We determined DAO and DAOA mRNA and protein expression across six brain regions in normal human post-mortem brain samples (16 weeks of gestation to 91 years) using quantitative real-time reverse transcription-polymerase chain reaction and enzyme-linked immunosorbent assay. We found higher expression of DAO mRNA in the cerebellum, whereas lower expression of DAO protein in the cerebellum compared to the other brain regions studied, which suggests post-transcriptional regulation. We detected DAOA protein but not DAOA mRNA in all brain regions studied, suggesting a tightly regulated expression. To understand this regulation at the transcriptional level, we analyzed DNA methylation levels at DAO and DAOA CpG sites in the cerebellum and frontal cortex of control human post-mortem brain obtained from Gene Expression Omnibus datasets. Indeed, DAO and DAOA CpG sites in the cerebellum were significantly more methylated than those in the frontal cortex. While investigating lifespan effects, we found that DAO mRNA levels were positively correlated with age <2 years in the cerebellum and amygdala. We also detected a significant positive correlation (controlled for age) between DAO and DAOA protein in all of the brain regions studied except for the frontal cortex. In summary, DAO and DAOA expression in the human brain are both age and brain region dependent.
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Affiliation(s)
- Vinita Jagannath
- Molecular and Neurobiochemistry Laboratory, Centre for Child and Adolescent Psychiatry Research, Department of Child and Adolescent Psychiatry and Psychotherapy, University Hospital of Psychiatry Zurich, University of ZurichZurich, Switzerland
| | - Zoya Marinova
- Molecular and Neurobiochemistry Laboratory, Centre for Child and Adolescent Psychiatry Research, Department of Child and Adolescent Psychiatry and Psychotherapy, University Hospital of Psychiatry Zurich, University of ZurichZurich, Switzerland
| | - Camelia-Maria Monoranu
- Department of Neuropathology, Institute of Pathology, University of WürzburgWürzburg, Germany
| | - Susanne Walitza
- Molecular and Neurobiochemistry Laboratory, Centre for Child and Adolescent Psychiatry Research, Department of Child and Adolescent Psychiatry and Psychotherapy, University Hospital of Psychiatry Zurich, University of ZurichZurich, Switzerland.,Neuroscience Center Zurich, University of Zurich and ETH ZurichZurich, Switzerland.,Zurich Center for Integrative Human Physiology, University of ZurichZurich, Switzerland
| | - Edna Grünblatt
- Molecular and Neurobiochemistry Laboratory, Centre for Child and Adolescent Psychiatry Research, Department of Child and Adolescent Psychiatry and Psychotherapy, University Hospital of Psychiatry Zurich, University of ZurichZurich, Switzerland.,Neuroscience Center Zurich, University of Zurich and ETH ZurichZurich, Switzerland.,Zurich Center for Integrative Human Physiology, University of ZurichZurich, Switzerland
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Acton D, Miles GB. Differential regulation of NMDA receptors by d-serine and glycine in mammalian spinal locomotor networks. J Neurophysiol 2017; 117:1877-1893. [PMID: 28202572 PMCID: PMC5411468 DOI: 10.1152/jn.00810.2016] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Revised: 01/11/2017] [Accepted: 02/11/2017] [Indexed: 12/11/2022] Open
Abstract
We provide evidence that NMDARs within murine spinal locomotor networks determine the frequency and amplitude of ongoing locomotor-related activity in vitro and that NMDARs are regulated by d-serine and glycine in a synapse-specific and activity-dependent manner. In addition, glycine transporter-1 is shown to be an important regulator of NMDARs during locomotor-related activity. These results show how excitatory transmission can be tuned to diversify the output repertoire of spinal locomotor networks in mammals. Activation of N-methyl-d-aspartate receptors (NMDARs) requires the binding of a coagonist, either d-serine or glycine, in addition to glutamate. Changes in occupancy of the coagonist binding site are proposed to modulate neural networks including those controlling swimming in frog tadpoles. Here, we characterize regulation of the NMDAR coagonist binding site in mammalian spinal locomotor networks. Blockade of NMDARs by d(−)-2-amino-5-phosphonopentanoic acid (d-APV) or 5,7-dichlorokynurenic acid reduced the frequency and amplitude of pharmacologically induced locomotor-related activity recorded from the ventral roots of spinal-cord preparations from neonatal mice. Furthermore, d-APV abolished synchronous activity induced by blockade of inhibitory transmission. These results demonstrate an important role for NMDARs in murine locomotor networks. Bath-applied d-serine enhanced the frequency of locomotor-related but not disinhibited bursting, indicating that coagonist binding sites are saturated during the latter but not the former mode of activity. Depletion of endogenous d-serine by d-amino acid oxidase or the serine-racemase inhibitor erythro-β-hydroxy-l-aspartic acid (HOAsp) increased the frequency of locomotor-related activity, whereas application of l-serine to enhance endogenous d-serine synthesis reduced burst frequency, suggesting a requirement for d-serine at a subset of synapses onto inhibitory interneurons. Consistent with this, HOAsp was ineffective during disinhibited activity. Bath-applied glycine (1–100 µM) failed to alter locomotor-related activity, whereas ALX 5407, a selective inhibitor of glycine transporter-1 (GlyT1), enhanced burst frequency, supporting a role for GlyT1 in NMDAR regulation. Together these findings indicate activity-dependent and synapse-specific regulation of the coagonist binding site within spinal locomotor networks, illustrating the importance of NMDAR regulation in shaping motor output. NEW & NOTEWORTHY We provide evidence that NMDARs within murine spinal locomotor networks determine the frequency and amplitude of ongoing locomotor-related activity in vitro and that NMDARs are regulated by d-serine and glycine in a synapse-specific and activity-dependent manner. In addition, glycine transporter-1 is shown to be an important regulator of NMDARs during locomotor-related activity. These results show how excitatory transmission can be tuned to diversify the output repertoire of spinal locomotor networks in mammals.
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Affiliation(s)
- David Acton
- School of Psychology and Neuroscience, University of St Andrews, St Andrews, Fife, United Kingdom
| | - Gareth B Miles
- School of Psychology and Neuroscience, University of St Andrews, St Andrews, Fife, United Kingdom
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46
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El-Tallawy HN, Saleem TH, El-Ebidi AM, Hassan MH, Gabra RH, Farghaly WM, Abo El-Maali N, Sherkawy HS. Clinical and biochemical study of d-serine metabolism among schizophrenia patients. Neuropsychiatr Dis Treat 2017; 13:1057-1063. [PMID: 28435276 PMCID: PMC5391825 DOI: 10.2147/ndt.s126979] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND Schizophrenia is a typical N-methyl-d-aspartate receptor (NMDA-R) hypofunction disorder. Decreased d-serine (d-Ser) levels in the periphery occur in schizophrenia and may reflect decreased availability of d-Ser to activate NMDA-R in the brain. OBJECTIVE The objective of this study was to investigate the role of d-Ser metabolism in the pathogenesis of schizophrenia via biochemical assays and correlates, the serum level of d-Ser, d-serine racemase (SR) (responsible for its formation from l-serine [l-Ser]) and d-amino acid oxidase (DAAO) (responsible for its catabolism), among different clinical types of schizophrenia patients. PATIENTS AND METHODS This cross-sectional case-control study was carried out on 100 patients and 50 controls. They were recruited from the outpatients' psychiatric unit of the Neuropsychiatric Department of Assiut University Hospital, Upper Egypt. The type of schizophrenia was determined according to the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV), while the severity of schizophrenia was determined according to the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5). Serum d-Ser levels were estimated using high-performance liquid chromatography (HPLC), while serum SR and DAAO were measured using commercially available enzyme-linked immunosorbent assay kits. RESULTS There were significantly lower mean serum levels of d-Ser and SR and significantly higher mean serum levels of DAAO (P-value <0.01 for each) among schizophrenia patients when compared with the control group. Paranoid schizophrenia had the highest frequency, with a significantly lower serum levels of d-Ser and SR in the residual type and significantly higher serum levels of DAAO in undifferentiated and catatonic types. Combined receiver-operating characteristic curve for serum d-Ser, SR and DAAO indicated that the best serum level cutoff points at which schizophrenia manifestations started to appear were ≤ 61.4 mg/L for d-Ser, ≤ 15.5 pg/mL for SR and >35.6 pg/mL for DAAO. CONCLUSION The present study confirms that disturbed d-Ser metabolism could be implicated in the pathogenesis of schizophrenia.
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Affiliation(s)
| | - Tahia H Saleem
- Department of Medical Biochemistry and Molecular Biology, Faculty of Medicine, Assiut University, Assiut
| | - Abdallah Maa El-Ebidi
- Department of Medical Biochemistry and Molecular Biology, Faculty of Medicine, Aswan University, Aswan
| | - Mohammed H Hassan
- Department of Medical Biochemistry and Molecular Biology, Qena Faculty of Medicine, South Valley University, Qena
| | | | | | - Nagwa Abo El-Maali
- Department of Chemistry, Faculty of Science, Assiut University, Assiut, Egypt
| | - Hoda S Sherkawy
- Department of Medical Biochemistry and Molecular Biology, Faculty of Medicine, Aswan University, Aswan
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47
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Jagannath V, Theodoridou A, Gerstenberg M, Franscini M, Heekeren K, Correll CU, Rössler W, Grünblatt E, Walitza S. Prediction Analysis for Transition to Schizophrenia in Individuals at Clinical High Risk for Psychosis: The Relationship of DAO, DAOA, and NRG1 Variants with Negative Symptoms and Cognitive Deficits. Front Psychiatry 2017; 8:292. [PMID: 29326614 PMCID: PMC5742321 DOI: 10.3389/fpsyt.2017.00292] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Accepted: 12/06/2017] [Indexed: 12/31/2022] Open
Abstract
Schizophrenia is characterized by positive and negative symptoms and cognitive dysfunction. The glutamate hypothesis of schizophrenia has been hypothesized to explain the negative symptoms and cognitive deficits better than the dopamine hypothesis alone. Therefore, we aimed to evaluate whether glutamatergic variants such as d-amino acid oxidase (DAO), DAO activator (DAOA)/G72, and neuregulin 1 (NRG1) single-nucleotide polymorphisms (SNPs) and their mRNA levels predicted (i) transition to schizophrenia spectrum disorders and (ii) research domain criteria (RDoC) domains, mainly negative valence and cognitive systems. In a 3-year prospective study cohort of 185 individuals (age: 13-35 years) at high risk and ultra-high risk (UHR) for psychosis, we assessed DAO (rs3918347, rs4623951), DAOA (rs778293, rs3916971, rs746187), and NRG1 (rs10503929) SNPs and their mRNA expression. Furthermore, we investigated their association with RDoC domains, mainly negative valence (e.g., anxiety, hopelessness) and cognitive (e.g., perception disturbances, disorganized symptoms) systems. NRG1 rs10503929 CC + CT versus TT genotype carriers experienced significantly more disorganized symptoms. DAOA rs746187 CC versus CT + TT genotype, DAOA rs3916971 TT versus TC + CC genotype, and DAO rs3918347 GA + AA versus GG genotype carriers experienced nominally more hopelessness, visual perception disturbances, and auditory perception disturbances, respectively. The schizophrenia risk G-allele of DAO rs3918347 nominally increased risk for those UHR individuals with attenuated positive symptoms syndrome. No association between DAO, DAOA, NRG1 SNPs, and conversion to schizophrenia spectrum disorders was observed. Our findings suggest that DAO, DAOA, and NRG1 polymorphisms might influence both RDoC negative valence and cognitive systems, but not transition to schizophrenia spectrum disorders.
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Affiliation(s)
- Vinita Jagannath
- Department of Child and Adolescent Psychiatry and Psychotherapy, University Hospital of Psychiatry Zurich, University of Zurich, Zurich, Switzerland
| | - Anastasia Theodoridou
- The Zurich Program for Sustainable Development of Mental Health Services (ZInEP), University Hospital of Psychiatry Zurich, Zurich, Switzerland.,Department of Psychiatry, Psychotherapy and Psychosomatics, University Hospital of Psychiatry Zurich, University of Zurich, Zurich, Switzerland
| | - Miriam Gerstenberg
- Department of Child and Adolescent Psychiatry and Psychotherapy, University Hospital of Psychiatry Zurich, University of Zurich, Zurich, Switzerland
| | - Maurizia Franscini
- Department of Child and Adolescent Psychiatry and Psychotherapy, University Hospital of Psychiatry Zurich, University of Zurich, Zurich, Switzerland
| | - Karsten Heekeren
- The Zurich Program for Sustainable Development of Mental Health Services (ZInEP), University Hospital of Psychiatry Zurich, Zurich, Switzerland.,Department of Psychiatry, Psychotherapy and Psychosomatics, University Hospital of Psychiatry Zurich, University of Zurich, Zurich, Switzerland
| | - Christoph U Correll
- The Zucker Hillside Hospital, Psychiatry Research, Northwell Health, Glen Oaks, NY, United States.,Hofstra Northwell School of Medicine, Hempstead, NY, United States.,The Feinstein Institute for Medical Research, Manhasset, NY, United States
| | - Wulf Rössler
- The Zurich Program for Sustainable Development of Mental Health Services (ZInEP), University Hospital of Psychiatry Zurich, Zurich, Switzerland
| | - Edna Grünblatt
- Department of Child and Adolescent Psychiatry and Psychotherapy, University Hospital of Psychiatry Zurich, University of Zurich, Zurich, Switzerland.,Neuroscience Center Zurich, University of Zurich and ETH Zurich, Zurich, Switzerland.,Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
| | - Susanne Walitza
- Department of Child and Adolescent Psychiatry and Psychotherapy, University Hospital of Psychiatry Zurich, University of Zurich, Zurich, Switzerland.,Neuroscience Center Zurich, University of Zurich and ETH Zurich, Zurich, Switzerland.,Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
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48
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Fujita Y, Ishima T, Hashimoto K. Supplementation with D-serine prevents the onset of cognitive deficits in adult offspring after maternal immune activation. Sci Rep 2016; 6:37261. [PMID: 27853241 PMCID: PMC5112512 DOI: 10.1038/srep37261] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Accepted: 10/26/2016] [Indexed: 12/26/2022] Open
Abstract
Prenatal maternal infection contributes to the etiology of schizophrenia, with D-serine, an endogenous co-agonist of the N-methyl-D-aspartate (NMDA) receptor, playing a role in the pathophysiology of this disease. We examined whether supplementation with D-serine during juvenile and adolescent stages could prevent the onset of cognitive deficits, prodromal and the core symptoms of schizophrenia in adult offspring after maternal immune activation (MIA). Juvenile offspring exposed prenatally to poly(I:C) showed reduced expression of NMDA receptor subunits in the hippocampus. Supplementing drinking water with D-serine (600 mg/L from P28 to P56) prevented the onset of cognitive deficits in adult offspring after MIA, in a significant manner. This study shows that supplementing offspring with D-serine during juvenile and adolescent stages could prevent the onset of psychosis in adulthood, after MIA. Therefore, early intervention with D-serine may prevent the occurrence of psychosis in high-risk subjects.
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Affiliation(s)
- Yuko Fujita
- Division of Clinical Neuroscience, Chiba University Center for Forensic Mental Health, Chiba 260-8670, Japan
| | - Tamaki Ishima
- Division of Clinical Neuroscience, Chiba University Center for Forensic Mental Health, Chiba 260-8670, Japan
| | - Kenji Hashimoto
- Division of Clinical Neuroscience, Chiba University Center for Forensic Mental Health, Chiba 260-8670, Japan
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49
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Schmidt RW, Thompson ML. Glycinergic signaling in the human nervous system: An overview of therapeutic drug targets and clinical effects. Ment Health Clin 2016; 6:266-276. [PMID: 29955481 PMCID: PMC6007534 DOI: 10.9740/mhc.2016.11.266] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Glycine and related endogenous compounds (d-serine, d-alanine, sarcosine) serve critical roles in both excitatory and inhibitory neurotransmission and are influenced by a multitude of enzymes and transporters, including glycine transporter 1 and 2 (GlyT1 and GlyT2), d-amino acid oxidase (DAAO), serine racemase (SRR), alanine-serine-cysteine transporter 1 (Asc-1), and kynurenine aminotransferase (KAT). MEDLINE, Web of Science, and PsychINFO were searched for relevant human trials of compounds. Many studies utilizing exogenous administration of small molecule agonists of the glycineB site of n-methyl-d-aspartate receptor have been studied as have a growing number of glycine transporter type 1 (GlyT1) inhibitors. The clinical effects of these compounds are reviewed as are the potential effects of newer novel compounds.
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Affiliation(s)
- Robert W Schmidt
- Clinical Pharmacy Specialist, Mental Health, Hunter Holmes McGuire Veterans Affairs Medical Center, Richmond, Virginia,
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50
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Rojas C, Alt J, Ator NA, Wilmoth H, Rais R, Hin N, DeVivo M, Popiolek M, Tsukamoto T, Slusher BS. Oral administration of D-alanine in monkeys robustly increases plasma and cerebrospinal fluid levels but experimental D-amino acid oxidase inhibitors had minimal effect. J Psychopharmacol 2016; 30:887-95. [PMID: 27287825 DOI: 10.1177/0269881116652586] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Hypofunction of the N-methyl-d-aspartate (NMDA) receptor is thought to exacerbate psychosis in patients diagnosed with schizophrenia. Consistent with this hypothesis, D-alanine, a co-agonist at the glycine site of the NMDA receptor, was shown to improve positive and cognitive symptoms when used as add-on therapy for schizophrenia treatment. However, D-alanine had to be administered at high doses (~7 g) to observe clinical effects. One possible reason for the high dose is that D-alanine could be undergoing oxidation by D-amino acid oxidase (DAAO) before it reaches the brain. If this is the case, the dose could be reduced by co-administration of D-alanine with a DAAO inhibitor (DAAOi). Early studies with rodents showed that co-administration of D-alanine with 5-chloro-benzo[d]isoxazol-3-ol (CBIO), a prototype DAAOi, significantly enhanced the levels of extracellular D-alanine in the frontal cortex compared with D-alanine alone. Further, the use of CBIO reduced the dose of D-alanine needed to attenuate prepulse inhibition deficits induced by dizocilpine. The objective of the work reported herein was to confirm the hypothesis that DAAO inhibition can enhance D-alanine exposure in a species closer to humans: non-human primates. We report that while oral D-alanine administration to baboons (10 mg/kg) enhanced D-alanine plasma and CSF levels over 20-fold versus endogenous levels, addition of experimental DAAOi to the regimen exhibited a 2.2-fold enhancement in plasma and no measurable effect on CSF levels. The results provide caution regarding the utility of DAAO inhibition to increase D-amino acid levels as treatment for patients with schizophrenia.
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Affiliation(s)
- Camilo Rojas
- Johns Hopkins Drug Discovery Program, Johns Hopkins School of Medicine, Baltimore, MD, USA Department of Comparative Medicine and Molecular Pathobiology, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - Jesse Alt
- Johns Hopkins Drug Discovery Program, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - Nancy A Ator
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - Heather Wilmoth
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - Rana Rais
- Johns Hopkins Drug Discovery Program, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - Niyada Hin
- Johns Hopkins Drug Discovery Program, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | | | | | - Takashi Tsukamoto
- Johns Hopkins Drug Discovery Program, Johns Hopkins School of Medicine, Baltimore, MD, USA Department of Neurology, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - Barbara S Slusher
- Johns Hopkins Drug Discovery Program, Johns Hopkins School of Medicine, Baltimore, MD, USA Department of Psychiatry and Behavioral Sciences, Johns Hopkins School of Medicine, Baltimore, MD, USA Department of Neurology, Johns Hopkins School of Medicine, Baltimore, MD, USA Department of Neuroscience, Johns Hopkins School of Medicine, Baltimore, MD, USA Department of Medicine, Johns Hopkins School of Medicine, Baltimore, MD, USA
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