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Beesley S, Kumar SS. The t-N-methyl-d-aspartate receptor: Making the case for d-Serine to be considered its inverse co-agonist. Neuropharmacology 2023:109654. [PMID: 37437688 DOI: 10.1016/j.neuropharm.2023.109654] [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: 04/27/2023] [Revised: 06/22/2023] [Accepted: 07/06/2023] [Indexed: 07/14/2023]
Abstract
The N-methyl-d-aspartate receptor (NMDAR) is an enigmatic macromolecule that has garnered a good deal of attention on account of its involvement in the cellular processes that underlie learning and memory, following its discovery in the mid twentieth century (Baudry and Davis, 1991). Yet, despite advances in knowledge about its function, there remains much more to be uncovered regarding the receptor's biophysical properties, subunit composition, and role in CNS physiology and pathophysiology. The motivation for this review stems from the need for synthesizing new information gathered about these receptors that sheds light on their role in synaptic plasticity and their dichotomous relationship with the amino acid d-serine through which they influence the pathogenesis of neurodegenerative diseases like temporal lobe epilepsy (TLE), the most common type of adult epilepsies (Beesley et al., 2020a). This review will outline pertinent ideas relating structure and function of t-NMDARs (GluN3 subunit-containing triheteromeric NMDARs) for which d-serine might serve as an inverse co-agonist. We will explore how tracing d-serine's origins blends glutamate-receptor biology with glial biology to help provide fresh perspectives on how neurodegeneration might interlink with neuroinflammation to initiate and perpetuate the disease state. Taken together, we envisage the review to deepen our understanding of endogenous d-serine's new role in the brain while also recognizing its therapeutic potential in the treatment of TLE that is oftentimes refractory to medications.
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Affiliation(s)
- Stephen Beesley
- Department of Biomedical Sciences, College of Medicine & Program in Neuroscience Florida State University, 1115 W. Call Street, Tallahassee, FL, 32306-4300, USA
| | - Sanjay S Kumar
- Department of Biomedical Sciences, College of Medicine & Program in Neuroscience Florida State University, 1115 W. Call Street, Tallahassee, FL, 32306-4300, USA.
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2
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Liu Y, Wu Z, Armstrong DW, Wolosker H, Zheng Y. Detection and analysis of chiral molecules as disease biomarkers. Nat Rev Chem 2023; 7:355-373. [PMID: 37117811 PMCID: PMC10175202 DOI: 10.1038/s41570-023-00476-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/09/2023] [Indexed: 04/30/2023]
Abstract
The chirality of small metabolic molecules is important in controlling physiological processes and indicating the health status of humans. Abnormal enantiomeric ratios of chiral molecules in biofluids and tissues occur in many diseases, including cancers and kidney and brain diseases. Thus, chiral small molecules are promising biomarkers for disease diagnosis, prognosis, adverse drug-effect monitoring, pharmacodynamic studies and personalized medicine. However, it remains difficult to achieve cost-effective and reliable analysis of small chiral molecules in clinical procedures, in part owing to their large variety and low concentration. In this Review, we describe current and emerging techniques that detect and quantify small-molecule enantiomers and their biological importance.
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Affiliation(s)
- Yaoran Liu
- Department of Electrical and Computer Engineering, The University of Texas at Austin, Austin, TX, USA
| | - Zilong Wu
- Walker Department of Mechanical Engineering, The University of Texas at Austin, Austin, TX, USA.
- Texas Materials Institute, The University of Texas at Austin, Austin, TX, USA.
| | - Daniel W Armstrong
- Department of Chemistry & Biochemistry, University of Texas at Arlington, Arlington, TX, USA.
| | - Herman Wolosker
- Department of Biochemistry, Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel.
| | - Yuebing Zheng
- Department of Electrical and Computer Engineering, The University of Texas at Austin, Austin, TX, USA.
- Walker Department of Mechanical Engineering, The University of Texas at Austin, Austin, TX, USA.
- Texas Materials Institute, The University of Texas at Austin, Austin, TX, USA.
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX, USA.
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3
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Yovanno RA, Chou TH, Brantley SJ, Furukawa H, Lau AY. Excitatory and inhibitory D-serine binding to the NMDA receptor. eLife 2022; 11:e77645. [PMID: 36301074 PMCID: PMC9612912 DOI: 10.7554/elife.77645] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2022] [Accepted: 09/09/2022] [Indexed: 01/19/2023] Open
Abstract
N-methyl-D-aspartate receptors (NMDARs) uniquely require binding of two different neurotransmitter agonists for synaptic transmission. D-serine and glycine bind to one subunit, GluN1, while glutamate binds to the other, GluN2. These agonists bind to the receptor's bi-lobed ligand-binding domains (LBDs), which close around the agonist during receptor activation. To better understand the unexplored mechanisms by which D-serine contributes to receptor activation, we performed multi-microsecond molecular dynamics simulations of the GluN1/GluN2A LBD dimer with free D-serine and glutamate agonists. Surprisingly, we observed D-serine binding to both GluN1 and GluN2A LBDs, suggesting that D-serine competes with glutamate for binding to GluN2A. This mechanism is confirmed by our electrophysiology experiments, which show that D-serine is indeed inhibitory at high concentrations. Although free energy calculations indicate that D-serine stabilizes the closed GluN2A LBD, its inhibitory behavior suggests that it either does not remain bound long enough or does not generate sufficient force for ion channel gating. We developed a workflow using pathway similarity analysis to identify groups of residues working together to promote binding. These conformation-dependent pathways were not significantly impacted by the presence of N-linked glycans, which act primarily by interacting with the LBD bottom lobe to stabilize the closed LBD.
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Affiliation(s)
- Remy A Yovanno
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of MedicineBaltimoreUnited States
| | - Tsung Han Chou
- W.M. Keck Structural Biology Laboratory, Cold Spring Harbor LaboratoryCold Spring HarborUnited States
| | - Sarah J Brantley
- Department of Biology, Johns Hopkins UniversityBaltimoreUnited States
| | - Hiro Furukawa
- W.M. Keck Structural Biology Laboratory, Cold Spring Harbor LaboratoryCold Spring HarborUnited States
| | - Albert Y Lau
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of MedicineBaltimoreUnited States
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4
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Multi-target action of β-alanine protects cerebellar tissue from ischemic damage. Cell Death Dis 2022; 13:747. [PMID: 36038575 PMCID: PMC9424312 DOI: 10.1038/s41419-022-05159-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Revised: 05/26/2022] [Accepted: 08/03/2022] [Indexed: 01/21/2023]
Abstract
Brain ischemic stroke is among the leading causes of death and long-term disability. New treatments that alleviate brain cell damage until blood supply is restored are urgently required. The emerging focus of anti-stroke strategies has been on blood-brain-barrier permeable drugs that exhibit multiple sites of action. Here, we combine single-cell electrophysiology with live-cell imaging to find that β-Alanine (β-Ala) protects key physiological functions of brain cells that are exposed to acute stroke-mimicking conditions in ex vivo brain preparations. β-Ala exerts its neuroprotective action through several distinct pharmacological mechanisms, none of which alone could reproduce the neuroprotective effect. Since β-Ala crosses the blood-brain barrier and is part of a normal human diet, we suggest that it has a strong potential for acute stroke treatment and facilitation of recovery.
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5
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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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6
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Ni X, Mori H. Complex Processes Underlying the Dynamic Changes of D-serine Levels in AD Brains. Curr Alzheimer Res 2022; 19:485-493. [PMID: 35346007 DOI: 10.2174/1567205019666220328123048] [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: 09/22/2021] [Revised: 02/02/2022] [Accepted: 02/10/2022] [Indexed: 01/27/2023]
Abstract
BACKGROUND Alzheimer's disease (AD) is a neurodegenerative disorder characterized by extracellular β-amyloid (Aβ) plaques and cognitive impairments. D-Serine, produced by the enzyme serine racemase (SR) in the brain, functions as an endogenous co-agonist at the glycine-binding site of N-methyl-D-aspartate receptor (NMDAR), has been implicated in the pathophysiological progression of AD. OBJECTIVES Evidence regarding the understanding of the role and dynamic modulation of D-serine during AD progression remains controversial. This literature review aims to offer novel research directions for studying the functions and metabolisms of D-serine in AD brains. METHODS We searched PubMed, using D-serine/SR and AD as keywords. Studies related to NMDAR dysfunction, neuronal excitotoxicity, D-serine dynamic changes and inflammatory response were included. RESULTS This review primarily discusses: (i) Aβ oligomers' role in NMDAR dysregulation, and the subsequent synaptic dysfunction and neuronal damage in AD, (ii) D-serine's role in NMDAR-elicited excitotoxicity, and (iii) the involvement of D-serine and SR in AD-related inflammatory pathological progression. CONCLUSION We also presented supposed metabolism and dynamic changes of D-serine during AD progression and hypothesized that: (i) the possible modulation of D-serine levels or SR expression as an effective method of alleviating neurotoxicity during AD pathophysiological progression, and (ii) the dynamic changes of D-serine levels in AD brains possibly resulting from complex processes.
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Affiliation(s)
- Xiance Ni
- Graduate School of Innovative Life Science, University of Toyama, Toyama 930-0194, Japan
| | - Hisashi Mori
- Graduate School of Innovative Life Science, University of Toyama, Toyama 930-0194, Japan.,Research Center for Idling Brain Science (RCIBS), University of Toyama, Toyama 930-0194, Japan
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7
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Umino A, Iwama H, Umino M, Shimazu D, Kiuchi Y, Nishikawa T. Effects of Quinolinate-Induced Lesion of the Medial Prefrontal Cortex on Prefrontal and Striatal Concentrations of D-Serine in the Rat. Neurochem Res 2022; 47:2728-2740. [PMID: 35604516 DOI: 10.1007/s11064-022-03627-8] [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: 11/01/2021] [Revised: 04/19/2022] [Accepted: 05/05/2022] [Indexed: 11/28/2022]
Abstract
D-Serine has been shown to play an important role in the expression and control of a variety of brain functions by acting as the endogenous coagonist for the N-methyl-D-aspartate type glutamate receptor (NMDAR), at least, in the forebrain. To obtain further insight into the still debatable cellular localization of the D-amino acid, we have examined the effects of the selective destruction of the neuronal cell bodies by quinolinate on the tissue or extracellular D-serine concentrations in the medial prefrontal cortex of the rat. A local quinolinate infusion into the bilateral medial prefrontal cortex produced a cortical lesion with a marked (- 65%) and non-significant alteration (- 5%) in the cortical and striatal tissue D-serine concentrations, respectively, 7 days post-infusion. In vivo microdialysis experiments in the right prefrontal lesion site 9 days after the quinolinate application revealed that the basal extracellular D-serine levels were also dramatically reduced (- 64%). A prominent reduction in the tissue levels of GABA in the interneurons of the prefrontal cortex (- 78%) without significant changes in those in the striatum (+ 12%) verified that a major lesion part was confined to the cortical portion. The lack of a significant influence of the prefrontal quinolinate lesion on its dopamine concentrations in the mesocortical dopamine projections suggests that the nerve terminals and axons in the lesion site may be spared. These findings are consistent with the perikarya-selective nature of the present quinolinate-induced lesion and further support the view that neuronal cell bodies of intrinsic neurons in the prefrontal cortical region contain substantial amounts of D-serine, which may sustain the basal extracellular concentrations of D-serine.
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Affiliation(s)
- Asami Umino
- Department of Pharmacology, School of Medicine, and Pharmacological Research Center, Showa University, Shinagawa-ku, Tokyo, 142-8555, Japan.,Psychiatry and Behavioral Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Bunkyo-ku, Tokyo, 113-8519, Japan.,Departments of Mental Disorder Research, National Institute of Neuroscience, NCNP, Kodaira-shi, Tokyo, 187-8502, Japan
| | - Hisayuki Iwama
- Psychiatry and Behavioral Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Bunkyo-ku, Tokyo, 113-8519, Japan.,Departments of Mental Disorder Research, National Institute of Neuroscience, NCNP, Kodaira-shi, Tokyo, 187-8502, Japan.,Kanagawa Psychiatric Center, Yokohama-shi, Kanagawa, 233-0006, Japan
| | - Masakazu Umino
- Department of Pharmacology, School of Medicine, and Pharmacological Research Center, Showa University, Shinagawa-ku, Tokyo, 142-8555, Japan.,Psychiatry and Behavioral Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Bunkyo-ku, Tokyo, 113-8519, Japan
| | - Dai Shimazu
- Psychiatry and Behavioral Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Bunkyo-ku, Tokyo, 113-8519, Japan.,Departments of Mental Disorder Research, National Institute of Neuroscience, NCNP, Kodaira-shi, Tokyo, 187-8502, Japan.,Musashishinjo-Kokorono Clinic, Kawasaki-shi, Kanagawa, 211-0044, Japan
| | - Yuji Kiuchi
- Department of Pharmacology, School of Medicine, and Pharmacological Research Center, Showa University, Shinagawa-ku, Tokyo, 142-8555, Japan
| | - Toru Nishikawa
- Department of Pharmacology, School of Medicine, and Pharmacological Research Center, Showa University, Shinagawa-ku, Tokyo, 142-8555, Japan. .,Psychiatry and Behavioral Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Bunkyo-ku, Tokyo, 113-8519, Japan. .,Departments of Mental Disorder Research, National Institute of Neuroscience, NCNP, Kodaira-shi, Tokyo, 187-8502, Japan.
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8
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Yoshikawa M, Kan T, Shirose K, Watanabe M, Matsuda M, Ito K, Kawaguchi M. Free d-Amino Acids in Salivary Gland in Rat. BIOLOGY 2022; 11:390. [PMID: 35336764 PMCID: PMC8944958 DOI: 10.3390/biology11030390] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Revised: 02/21/2022] [Accepted: 02/28/2022] [Indexed: 06/14/2023]
Abstract
Free d-amino acids, which are enantiomers of l-amino acids, are found in mammals, including humans, and play an important role in a range of physiological functions in the central nervous system and peripheral tissues. Several d-amino acids have been observed in saliva, but their origin and the enzymes involved in their metabolism and catabolism remain to be clarified. In the present study, large amounts of d-aspartic acid and small amounts of d-serine and d-alanine were detected in all three major salivary glands in rat. No other d-enantiomers were detected. Protein expression of d-amino acid oxidase and d-aspartate oxidase, the enzymes responsible for the oxidative deamination of neutral and dicarboxylic d-amino acids, respectively, were detected in all three types of salivary gland. Furthermore, protein expression of the d-serine metabolic enzyme, serine racemase, in parotid glands amounted to approximately 40% of that observed in the cerebral cortex. The N-methyl-d-aspartic acid subunit proteins NR1 and NR2D were detected in all three major salivary glands. The results of the present study suggest that d-amino acids play a physiological role in a range of endocrine and exocrine function in salivary glands.
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Affiliation(s)
- Masanobu Yoshikawa
- Department of Clinical Pharmacology, School of Medicine, Tokai University, Isehara 259-1193, Japan
| | - Takugi Kan
- Department of Anesthesiology, School of Medicine, Tokai University, Isehara 259-1193, Japan; (T.K.); (K.S.); (M.W.); (M.M.); (K.I.)
| | - Kosuke Shirose
- Department of Anesthesiology, School of Medicine, Tokai University, Isehara 259-1193, Japan; (T.K.); (K.S.); (M.W.); (M.M.); (K.I.)
| | - Mariko Watanabe
- Department of Anesthesiology, School of Medicine, Tokai University, Isehara 259-1193, Japan; (T.K.); (K.S.); (M.W.); (M.M.); (K.I.)
| | - Mitsumasa Matsuda
- Department of Anesthesiology, School of Medicine, Tokai University, Isehara 259-1193, Japan; (T.K.); (K.S.); (M.W.); (M.M.); (K.I.)
| | - Kenji Ito
- Department of Anesthesiology, School of Medicine, Tokai University, Isehara 259-1193, Japan; (T.K.); (K.S.); (M.W.); (M.M.); (K.I.)
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9
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Astrocytic contribution to glutamate-related central respiratory chemoreception in vertebrates. Respir Physiol Neurobiol 2021; 294:103744. [PMID: 34302992 DOI: 10.1016/j.resp.2021.103744] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 07/01/2021] [Accepted: 07/18/2021] [Indexed: 12/24/2022]
Abstract
Central respiratory chemoreceptors play a key role in the respiratory homeostasis by sensing CO2 and H+ in brain and activating the respiratory neural network. This ability of specific brain regions to respond to acidosis and hypercapnia is based on neuronal and glial mechanisms. Several decades ago, glutamatergic transmission was proposed to be involved as a main mechanism in central chemoreception. However, a complete identification of mechanism has been elusive. At the rostral medulla, chemosensitive neurons of the retrotrapezoid nucleus (RTN) are glutamatergic and they are stimulated by ATP released by RTN astrocytes in response to hypercapnia. In addition, recent findings show that caudal medullary astrocytes in brainstem can also contribute as CO2 and H+ sensors that release D-serine and glutamate, both gliotransmitters able to activate the respiratory neural network. In this review, we describe the mammalian astrocytic glutamatergic contribution to the central respiratory chemoreception trying to trace in vertebrates the emergence of several components involved in this process.
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10
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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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11
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Kellner S, Abbasi A, Carmi I, Heinrich R, Garin-Shkolnik T, Hershkovitz T, Giladi M, Haitin Y, Johannesen KM, Steensbjerre Møller R, Berlin S. Two de novo GluN2B mutations affect multiple NMDAR-functions and instigate severe pediatric encephalopathy. eLife 2021; 10:67555. [PMID: 34212862 PMCID: PMC8260228 DOI: 10.7554/elife.67555] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Accepted: 06/27/2021] [Indexed: 12/15/2022] Open
Abstract
The N-methyl-D-aspartate receptors (NMDARs; GluNRS) are glutamate receptors, commonly located at excitatory synapses. Mutations affecting receptor function often lead to devastating neurodevelopmental disorders. We have identified two toddlers with different heterozygous missense mutations of the same, and highly conserved, glycine residue located in the ligand-binding-domain of GRIN2B: G689C and G689S. Structure simulations suggest severely impaired glutamate binding, which we confirm by functional analysis. Both variants show three orders of magnitude reductions in glutamate EC50, with G689S exhibiting the largest reductions observed for GRIN2B (~2000-fold). Moreover, variants multimerize with, and upregulate, GluN2Bwt-subunits, thus engendering a strong dominant-negative effect on mixed channels. In neurons, overexpression of the variants instigates suppression of synaptic GluNRs. Lastly, while exploring spermine potentiation as a potential treatment, we discovered that the variants fail to respond due to G689’s novel role in proton-sensing. Together, we describe two unique variants with extreme effects on channel function. We employ protein-stability measures to explain why current (and future) LBD mutations in GluN2B primarily instigate Loss-of-Function.
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Affiliation(s)
- Shai Kellner
- Department of Neuroscience, Ruth and Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel
| | - Abeer Abbasi
- Department of Neuroscience, Ruth and Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel
| | - Ido Carmi
- Department of Neuroscience, Ruth and Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel
| | - Ronit Heinrich
- Department of Neuroscience, Ruth and Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel
| | | | | | - Moshe Giladi
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Yoni Haitin
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Katrine M Johannesen
- Department of Epilepsy Genetics and Personalized Treatment, the Danish Epilepsy Centre, Dianalund, Denmark.,Institute for Regional Health Services, University of Southern Denmark, Odense, Denmark
| | - Rikke Steensbjerre Møller
- Department of Epilepsy Genetics and Personalized Treatment, the Danish Epilepsy Centre, Dianalund, Denmark.,Institute for Regional Health Services, University of Southern Denmark, Odense, Denmark
| | - Shai Berlin
- Department of Neuroscience, Ruth and Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel
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12
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Ploux E, Bouet V, Radzishevsky I, Wolosker H, Freret T, Billard JM. Serine Racemase Deletion Affects the Excitatory/Inhibitory Balance of the Hippocampal CA1 Network. Int J Mol Sci 2020; 21:E9447. [PMID: 33322577 PMCID: PMC7763099 DOI: 10.3390/ijms21249447] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 12/02/2020] [Accepted: 12/10/2020] [Indexed: 12/13/2022] Open
Abstract
d-serine is the major co-agonist of N-methyl-D-aspartate receptors (NMDAR) at CA3/CA1 hippocampal synapses, the activation of which drives long-term potentiation (LTP). The use of mice with targeted deletion of the serine racemase (SR) enzyme has been an important tool to uncover the physiological and pathological roles of D-serine. To date, some uncertainties remain regarding the direction of LTP changes in SR-knockout (SR-KO) mice, possibly reflecting differences in inhibitory GABAergic tone in the experimental paradigms used in the different studies. On the one hand, our extracellular recordings in hippocampal slices show that neither isolated NMDAR synaptic potentials nor LTP were altered in SR-KO mice. This was associated with a compensatory increase in hippocampal levels of glycine, another physiologic NMDAR co-agonist. SR-KO mice displayed no deficits in spatial learning, reference memory and cognitive flexibility. On the other hand, SR-KO mice showed a weaker LTP and a lower increase in NMDAR potentials compared to controls when GABAA receptors were pharmacologically blocked. Our results indicate that depletion of endogenous D-serine caused a reduced inhibitory activity in CA1 hippocampal networks, altering the excitatory/inhibitory balance, which contributes to preserve functional plasticity at synapses and to maintain related cognitive abilities.
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Affiliation(s)
- Eva Ploux
- UNICAEN, INSERM, COMETE, Cyceron, CHU Caen, Normandie University, 14000 Caen, France; (E.P.); (V.B.); (T.F.)
| | - Valentine Bouet
- UNICAEN, INSERM, COMETE, Cyceron, CHU Caen, Normandie University, 14000 Caen, France; (E.P.); (V.B.); (T.F.)
| | - Inna Radzishevsky
- Department of Biochemistry, Technion-Israel Institute of Technology, Rappaport Faculty of Medicine, Haifa 31096, Israel; (I.R.); (H.W.)
| | - Herman Wolosker
- Department of Biochemistry, Technion-Israel Institute of Technology, Rappaport Faculty of Medicine, Haifa 31096, Israel; (I.R.); (H.W.)
| | - Thomas Freret
- UNICAEN, INSERM, COMETE, Cyceron, CHU Caen, Normandie University, 14000 Caen, France; (E.P.); (V.B.); (T.F.)
| | - Jean-Marie Billard
- UNICAEN, INSERM, COMETE, Cyceron, CHU Caen, Normandie University, 14000 Caen, France; (E.P.); (V.B.); (T.F.)
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13
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Roles of N-methyl-D-aspartate receptors and D-amino acids in cancer cell viability. Mol Biol Rep 2020; 47:6749-6758. [PMID: 32892308 DOI: 10.1007/s11033-020-05733-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Accepted: 08/19/2020] [Indexed: 12/22/2022]
Abstract
N-methyl-D-aspartate (NMDA) receptors, which are widely present in the central nervous system, have also been found to be up-regulated in a variety of cancer cells and tumors and they can play active roles in cancer cell growth regulation. NMDA receptor antagonists have been found to affect cancer cell viability and interfere with tumor growth. Moreover, cancer cells also have been shown to have elevated levels of some D-amino acids. Two human skin cell lines: Hs 895.T skin cancer and Hs 895.Sk skin normal cells were investigated. They were derived from the same patient to provide tumor and normal counterparts for comparative studies. The expression of specific NMDA receptors was confirmed for the first time in both skin cell lines. Dizocilpine (MK-801) and memantine, NMDA receptor channel blockers, were found to inhibit the growth of human skin cells by reducing or stopping NMDA receptor activity. Addition of D-Ser, D-Ala, or D-Asp, however, significantly reversed the antiproliferative effect on the human skin cells triggered by MK-801 or memantine. Even more interesting was the finding that the specific intracellular composition of a few relatively uncommon amino acids was selectively elevated in skin cancer cells when exposed to MK-801. It appears that a few specific and upregulated D-amino acids can reverse the drug-induced antiproliferative effect in skin cancer cells via the reactivation of NMDA receptors. This study provides a possible innovative anticancer therapy by acting on the D-amino acid pathway in cancer cells either blocking or activating their regulatory enzymes.
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14
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Beltrán-Castillo S, Olivares MJ, Ochoa M, Barria J, Chacón M, von Bernhardi R, Eugenín J. d-serine regulation of the timing and architecture of the inspiratory burst in neonatal mice. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2020; 1868:140484. [PMID: 32652125 DOI: 10.1016/j.bbapap.2020.140484] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2020] [Revised: 06/08/2020] [Accepted: 06/30/2020] [Indexed: 10/23/2022]
Abstract
d-serine, released from mouse medullary astrocytes in response to increased CO2 levels, boosts the respiratory frequency to adapt breathing to physiological demands. We analyzed in mouse neonates, the influence of d-serine upon inspiratory/expiratory durations and the architecture of the inspiratory burst, assessed by pwelch's power spectrum density (PSD) and continuous wavelet transform (CWT) analyses. Suction electrode recordings were performed in slices from the ventral respiratory column (VRC), site of generation of the respiratory rhythm, and in brainstem-spinal cord (en bloc) preparations, from the C5 ventral roots, containing phrenic fibers that in vivo innervate and drive the diaphragm, the main inspiratory muscle. In en bloc and slice preparations, d-serine (100 μM) reduced the expiratory, but not the inspiratory duration, and increased the frequency and the regularity of the respiratory rhythm. In en bloc preparations, d-serine (100 μM) also increased slightly the amplitude of the integrated inspiratory burst and the area under the curve of the integrated inspiratory burst, suggesting a change in the recruitment or the firing pattern of neurons within the burst. Time-frequency analyses revealed that d-serine changed the burst architecture of phrenic roots, widening their frequency spectrum and shifting the position of the core of firing frequencies towards the onset of the inspiratory burst. At the VRC, no clear d-serine induced changes in the frequency-time domain could be established. Our results show that d-serine not only regulates the timing of the respiratory cycle, but also the recruitment strategy of phrenic motoneurons within the inspiratory burst.
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Affiliation(s)
- S Beltrán-Castillo
- Facultad de Química y Biología, Departamento de Biología, Universidad de Santiago de Chile, USACH, PO 9170022, Santiago, Chile; Facultad de Medicina, Departamento de Neurología, Pontificia Universidad Católica de Chile, PO 8330024, Santiago, Chile
| | - M J Olivares
- Facultad de Química y Biología, Departamento de Biología, Universidad de Santiago de Chile, USACH, PO 9170022, Santiago, Chile
| | - M Ochoa
- Facultad de Química y Biología, Departamento de Biología, Universidad de Santiago de Chile, USACH, PO 9170022, Santiago, Chile
| | - J Barria
- Facultad de Química y Biología, Departamento de Biología, Universidad de Santiago de Chile, USACH, PO 9170022, Santiago, Chile; Facultad de Medicina, Universidad Diego Portales, PO 8370007, Santiago, Chile
| | - M Chacón
- Facultad de Ingeniería, Departamento de Ingeniería Informática, Universidad de Santiago de Chile, USACH, PO 9170022 Santiago, Chile
| | - R von Bernhardi
- Facultad de Medicina, Departamento de Neurología, Pontificia Universidad Católica de Chile, PO 8330024, Santiago, Chile.
| | - J Eugenín
- Facultad de Química y Biología, Departamento de Biología, Universidad de Santiago de Chile, USACH, PO 9170022, Santiago, Chile.
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15
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McLaughlin C, Clements J, Oprişoreanu AM, Sylantyev S. The role of tonic glycinergic conductance in cerebellar granule cell signalling and the effect of gain-of-function mutation. J Physiol 2019; 597:2457-2481. [PMID: 30875431 DOI: 10.1113/jp277626] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Accepted: 03/14/2019] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS A T258F mutation of the glycine receptor increases the receptor affinity to endogenous agonists, modifies single-channel conductance and shapes response decay kinetics. Glycine receptors of cerebellar granule cells play their functional role not continuously, but when the granule cell layer starts receiving a high amount of excitatory inputs. Despite their relative scarcity, tonically active glycine receptors of cerebellar granule cells make a significant impact on action potential generation and inter-neuronal crosstalk, and modulate synaptic plasticity in neural networks; extracellular glycine increases probability of postsynaptic response occurrence acting at NMDA receptors and decreases this probability acting at glycine receptors. Tonic conductance through glycine receptors of cerebellar granule cells is a yet undiscovered element of the biphasic mechanism that regulates processing of sensory inputs in the cerebellum. A T258F point mutation disrupts this biphasic mechanism, thus illustrating the possible role of the gain-of-function mutations of the glycine receptor in development of neural pathologies. ABSTRACT Functional glycine receptors (GlyRs) have been repeatedly detected in cerebellar granule cells (CGCs), where they deliver exclusively tonic inhibitory signals. The functional role of this signalling, however, remains unclear. Apart from that, there is accumulating evidence of the important role of GlyRs in cerebellar structures in development of neural pathologies such as hyperekplexia, which can be triggered by GlyR gain-of-function mutations. In this research we initially tested functional properties of GlyRs, carrying the yet understudied T258F gain-of-function mutation, and found that this mutation makes significant modifications in GlyR response to endogenous agonists. Next, we clarified the role of tonic GlyR conductance in neuronal signalling generated by single CGCs and by neural networks in cell cultures and in living cerebellar tissue of C57Bl-6J mice. We found that GlyRs of CGCs deliver a significant amount of tonic inhibition not continuously, but when the cerebellar granule layer starts receiving substantial excitatory input. Under these conditions tonically active GlyRs become a part of neural signalling machinery allowing generation of action potential (AP) bursts of limited length in response to sensory-evoked signals. GlyRs of CGCs support a biphasic modulatory mechanism which enhances AP firing when excitatory input intensity is low, but suppresses it when excitatory input rises to a certain critical level. This enables one of the key functions of the CGC layer: formation of sensory representations and their translation into motor output. Finally, we have demonstrated that the T258F mutation in CGC GlyRs modifies single-cell and neural network signalling, and breaks a biphasic modulation of the AP-generating machinery.
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Affiliation(s)
- Catherine McLaughlin
- Gene Therapy Group, The Roslin Institute, University of Edinburgh, Easter Bush, Midlothian, EH25 9RG, UK
| | - John Clements
- The John Curtin School of Medical Research, Australian National University, 131 Garran Road, Canberra, ACT 2601, Australia
| | - Ana-Maria Oprişoreanu
- Center for Discovery Brain Sciences, University of Edinburgh, 49 Little France Crescent, Edinburgh, EH16 4SB, UK
| | - Sergiy Sylantyev
- Center for Clinical Brain Sciences, University of Edinburgh, 49 Little France Crescent, Edinburgh, EH16 4SB, UK
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16
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Abudara V, Retamal MA, Del Rio R, Orellana JA. Synaptic Functions of Hemichannels and Pannexons: A Double-Edged Sword. Front Mol Neurosci 2018; 11:435. [PMID: 30564096 PMCID: PMC6288452 DOI: 10.3389/fnmol.2018.00435] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Accepted: 11/08/2018] [Indexed: 01/18/2023] Open
Abstract
The classical view of synapses as the functional contact between presynaptic and postsynaptic neurons has been challenged in recent years by the emerging regulatory role of glial cells. Astrocytes, traditionally considered merely supportive elements are now recognized as active modulators of synaptic transmission and plasticity at the now so-called "tripartite synapse." In addition, an increasing body of evidence indicates that beyond immune functions microglia also participate in various processes aimed to shape synaptic plasticity. Release of neuroactive compounds of glial origin, -process known as gliotransmission-, constitute a widespread mechanism through which glial cells can either potentiate or reduce the synaptic strength. The prevailing vision states that gliotransmission depends on an intracellular Ca2+/exocytotic-mediated release; notwithstanding, growing evidence is pointing at hemichannels (connexons) and pannexin channels (pannexons) as alternative non-vesicular routes for gliotransmitters efflux. In concurrence with this novel concept, both hemichannels and pannexons are known to mediate the transfer of ions and signaling molecules -such as ATP and glutamate- between the cytoplasm and the extracellular milieu. Importantly, recent reports show that glial hemichannels and pannexons are capable to perceive synaptic activity and to respond to it through changes in their functional state. In this article, we will review the current information supporting the "double edge sword" role of hemichannels and pannexons in the function of central and peripheral synapses. At one end, available data support the idea that these channels are chief components of a feedback control mechanism through which gliotransmitters adjust the synaptic gain in either resting or stimulated conditions. At the other end, we will discuss how the excitotoxic release of gliotransmitters and [Ca2+]i overload linked to the opening of hemichannels/pannexons might impact cell function and survival in the nervous system.
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Affiliation(s)
- Verónica Abudara
- Departamento de Fisiología, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
| | - Mauricio A Retamal
- Centro de Fisiología Celular e Integrativa, Facultad de Medicina, Clínica Alemana Universidad del Desarrollo, Santiago, Chile.,Department of Cell Physiology and Molecular Biophysics, Center for Membrane Protein Research, Texas Tech University Health Sciences Center, Lubbock, TX, United States.,Programa de Comunicación Celular en Cáncer, Instituto de Ciencias e Innovación en Medicina, Santiago, Chile
| | - Rodrigo Del Rio
- Laboratory of Cardiorespiratory Control, Departamento de Fisiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile.,Centro de Envejecimiento y Regeneración, Pontificia Universidad Católica de Chile, Santiago, Chile.,Centro de Excelencia en Biomedicina de Magallanes, Universidad de Magallanes, Punta Arenas, Chile
| | - Juan A Orellana
- Departamento de Neurología, Escuela de Medicina and Centro Interdisciplinario de Neurociencias, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile.,Centro de Investigación y Estudio del Consumo de Alcohol en Adolescentes, Santiago, Chile
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17
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Monitoring hippocampal glycine with the computationally designed optical sensor GlyFS. Nat Chem Biol 2018; 14:861-869. [DOI: 10.1038/s41589-018-0108-2] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2017] [Accepted: 06/21/2018] [Indexed: 01/01/2023]
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18
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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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19
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Campos-Beltrán D, Konradsson-Geuken Å, Quintero JE, Marshall L. Amperometric Self-Referencing Ceramic Based Microelectrode Arrays for D-Serine Detection. BIOSENSORS-BASEL 2018; 8:bios8010020. [PMID: 29509674 PMCID: PMC5872068 DOI: 10.3390/bios8010020] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Revised: 02/15/2018] [Accepted: 03/02/2018] [Indexed: 01/29/2023]
Abstract
D-serine is the major D-amino acid in the mammalian central nervous system. As the dominant co-agonist of the endogenous synaptic NMDA receptor, D-serine plays a role in synaptic plasticity, learning, and memory. Alterations in D-serine are linked to neuropsychiatric disorders including schizophrenia. Thus, it is of increasing interest to monitor the concentration of D-serine in vivo as a relevant player in dynamic neuron-glia network activity. Here we present a procedure for amperometric detection of D-serine with self-referencing ceramic-based microelectrode arrays (MEAs) coated with D-amino acid oxidase from the yeast Rhodotorulagracilis (RgDAAO). We demonstrate in vitro D-serine recordings with a mean sensitivity of 8.61 ± 0.83 pA/µM to D-serine, a limit of detection (LOD) of 0.17 ± 0.01 µM, and a selectivity ratio of 80:1 or greater for D-serine over ascorbic acid (mean ± SEM; n = 12) that can be used for freely moving studies.
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Affiliation(s)
- Diana Campos-Beltrán
- Institute of Experimental and Clinical Pharmacology and Toxicology, University of Lübeck, Ratzeburger Allee 160, 23562 Lübeck, Germany.
| | - Åsa Konradsson-Geuken
- The Department of Pharmaceutical Biosciences, Uppsala University, 75124 Uppsala, Sweden.
- The Department of Physiology and Pharmacology, Karolinska Institutet, 17177 Stockholm, Sweden.
| | - Jorge E Quintero
- CenMeT, University of Kentucky, Lexington, 40506 KY, USA.
- Quanteon LLC, Nicholasville, 40356 KY, USA.
| | - Lisa Marshall
- Institute of Experimental and Clinical Pharmacology and Toxicology, University of Lübeck, Ratzeburger Allee 160, 23562 Lübeck, Germany.
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20
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Ishiwata S, Hattori K, Sasayama D, Teraishi T, Miyakawa T, Yokota Y, Matsumura R, Nishikawa T, Kunugi H. Cerebrospinal fluid D-serine concentrations in major depressive disorder negatively correlate with depression severity. J Affect Disord 2018; 226:155-162. [PMID: 28985587 DOI: 10.1016/j.jad.2017.09.035] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2017] [Revised: 07/09/2017] [Accepted: 09/23/2017] [Indexed: 12/28/2022]
Abstract
BACKGROUND D-serine is an endogenous co-agonist of N-methyl-D-aspartate receptor (NMDAR) and plays an important role in glutamate neurotransmission. Several studies suggested the possible involvement of D-serine related in the pathophysiology of psychiatric disorders including major depression disorders (MDD). We tried to examine whether cerebrospinal fluid (CSF) or plasma D-serine concentrations are altered in MDD and whether D-serine concentrations correlated with disease severity. METHODS 26 MDD patients and 27 healthy controls matched for age, sex and ethnicity were enrolled. We measured amino acids in these samples using by high-performance liquid chromatography with fluorometric detection. RESULTS D-serine and L-serine, precursor of D-serine, levels in CSF or plasma were not significantly different in patients of MDD compared to controls. Furthermore, a significant correlation between D-serine levels in CSF and Hamilton Depression Rating Scale (HAMD)-17 score was observed (r = -0.65, p = 0.006). Furthermore, we found a positive correlation between CSF D-serine and HVA concentrations in MDD patients (r = 0.54, p = 0.007). CSF D-serine concentrations were correlated with those of plasma in MDD (r = 0.61, p = 0.01) but not in controls. In CSF, we also confirmed a significant correlation between D-serine and L-serine levels in MDD (r = 0.72, p < 0.0001) and controls (r = 0.70, p < 0.0001). CONCLUSIONS The study has some limitations; sample size was relatively small and most patients were medicated. We revealed that CSF D-serine concentrations were correlated with depression severity and HVA concentrations and further investigation were required to reveal the effect of medication and disease heterogeneity.
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Affiliation(s)
- Sayuri Ishiwata
- Department of Mental Disorder Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Tokyo 187-8502, Japan; Department of Psychiatry and Behavioral Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo 113-8519, Japan
| | - Kotaro Hattori
- Department of Mental Disorder Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Tokyo 187-8502, Japan; Translational Medical Center, National Center of Neurology and Psychiatry, Tokyo 187-8551, Japan
| | - Daimei Sasayama
- Department of Mental Disorder Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Tokyo 187-8502, Japan
| | - Toshiya Teraishi
- Department of Mental Disorder Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Tokyo 187-8502, Japan
| | - Tomoko Miyakawa
- Translational Medical Center, National Center of Neurology and Psychiatry, Tokyo 187-8551, Japan
| | - Yuuki Yokota
- Translational Medical Center, National Center of Neurology and Psychiatry, Tokyo 187-8551, Japan
| | - Ryo Matsumura
- Translational Medical Center, National Center of Neurology and Psychiatry, Tokyo 187-8551, Japan
| | - Toru Nishikawa
- Department of Psychiatry and Behavioral Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo 113-8519, Japan
| | - Hiroshi Kunugi
- Department of Mental Disorder Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Tokyo 187-8502, Japan.
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21
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Beltrán-Castillo S, Olivares MJ, Contreras RA, Zúñiga G, Llona I, von Bernhardi R, Eugenín JL. D-serine released by astrocytes in brainstem regulates breathing response to CO 2 levels. Nat Commun 2017; 8:838. [PMID: 29018191 PMCID: PMC5635109 DOI: 10.1038/s41467-017-00960-3] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Accepted: 08/09/2017] [Indexed: 11/17/2022] Open
Abstract
Central chemoreception is essential for adjusting breathing to physiological demands, and for maintaining CO2 and pH homeostasis in the brain. CO2-induced ATP release from brainstem astrocytes stimulates breathing. NMDA receptor (NMDAR) antagonism reduces the CO2-induced hyperventilation by unknown mechanisms. Here we show that astrocytes in the mouse caudal medullary brainstem can synthesize, store, and release d-serine, an agonist for the glycine-binding site of the NMDAR, in response to elevated CO2 levels. We show that systemic and raphe nucleus d-serine administration to awake, unrestrained mice increases the respiratory frequency. Application of d-serine to brainstem slices also increases respiratory frequency, which was prevented by NMDAR blockade. Inhibition of d-serine synthesis, enzymatic degradation of d-serine, or the sodium fluoroacetate-induced impairment of astrocyte functions decrease the basal respiratory frequency and the CO2-induced respiratory response in vivo and in vitro. Our findings suggest that astrocytic release of d-serine may account for the glutamatergic contribution to central chemoreception. Astrocytes are involved in chemoreception in brainstem areas that regulate breathing rhythm, and astrocytes are known to release d-serine. Here the authors show that astrocyte release of d-serine contributes to CO2 sensing and breathing in brainstem slices, and in vivo in awake unrestrained mice.
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Affiliation(s)
- S Beltrán-Castillo
- Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile, USACH, Santiago, 9170022, Chile
| | - M J Olivares
- Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile, USACH, Santiago, 9170022, Chile
| | - R A Contreras
- Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile, USACH, Santiago, 9170022, Chile
| | - G Zúñiga
- Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile, USACH, Santiago, 9170022, Chile
| | - I Llona
- Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile, USACH, Santiago, 9170022, Chile
| | - R von Bernhardi
- Departamento de Neurología, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago, 8330024, Chile.
| | - J L Eugenín
- Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile, USACH, Santiago, 9170022, Chile.
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22
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Ishiwata S, Umino A, Nishikawa T. Involvement of neuronal and glial activities in control of the extracellular d-serine concentrations by the AMPA glutamate receptor in the mouse medial prefrontal cortex. Neurochem Int 2017; 119:120-125. [PMID: 28966065 DOI: 10.1016/j.neuint.2017.09.009] [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: 06/16/2017] [Revised: 09/03/2017] [Accepted: 09/13/2017] [Indexed: 11/30/2022]
Abstract
It has been well accepted that d-serine may be an exclusive endogenous coagonist for the N-methyl-d-aspartate (NMDA)-type glutamate receptor in mammalian forebrain regions. We have recently found by using an in vivo dialysis method that an intra-medial prefrontal cortex infusion of S-α-amino-3-hydroxyl-5-methyl-4-isoxazole-propionate (S-AMPA), a selective AMPA-type glutamate receptor agonist, causes a reduction in the extracellular levels of d-serine in a calcium-permeable AMPA receptor antagonist-sensitive manner. The inhibitory influence by the AMPA receptor on the extracellular d-serine, however, contradicts the data obtained from in vitro experiments that the AMPA receptor stimulation leads to facilitation of the d-serine liberation. This discrepancy appears to be due to the different cell setups between the in vivo and in vitro preparations. From the viewpoints of the previous reports indicating (1) the neuronal presence of d-serine synthesizing enzyme, serine racemase, and d-serine-like immunoreactivity and (2) the same high tissue concentrations of d-serine in the glia-enriched white matter and in the neuron-enriched gray matter of the mammalian neocortex, we have now investigated in the mouse medial prefrontal cortex, the effects of attenuation of neuronal and glial activities, by tetrodotoxin or fluorocitrate, respectively, on the S-AMPA-induced downregulation of the extracellular d-serine contents. In vivo dialysis studies revealed that a local infusion of tetrodotoxin or fluorocitrate eliminated the ability of S-AMPA given intra-cortically to cause a significant decrease in the dialysate concentrations of d-serine without affecting the elevating effects of S-AMPA on those of glycine, another intrinsic coagonist for the NMDA receptor. These findings suggest that the control by the AMPA receptor of the extracellular d-serine levels could be modulated by the neuronal and glial activities in the prefrontal cortex. It cannot be excluded that fluorocitrate would indirectly alter the modulation by changing synaptic neurotransmission via glial activity attenuation as previously reported.
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Affiliation(s)
- Sayuri Ishiwata
- Department of Psychiatry and Behavioral Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8519, Japan; Center for Brain Integration Research, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8519, Japan
| | - Asami Umino
- Department of Psychiatry and Behavioral Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8519, Japan; Center for Brain Integration Research, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8519, Japan
| | - Toru Nishikawa
- Department of Psychiatry and Behavioral Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8519, Japan; Center for Brain Integration Research, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8519, Japan.
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Contribution of Astroglial Cx43 Hemichannels to the Modulation of Glutamatergic Currents by D-Serine in the Mouse Prefrontal Cortex. J Neurosci 2017; 37:9064-9075. [PMID: 28821660 DOI: 10.1523/jneurosci.2204-16.2017] [Citation(s) in RCA: 69] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Revised: 05/16/2017] [Accepted: 06/10/2017] [Indexed: 11/21/2022] Open
Abstract
Astrocytes interact dynamically with neurons by modifying synaptic activity and plasticity. This interplay occurs through a process named gliotransmission, meaning that neuroactive molecules are released by astrocytes. Acting as a gliotransmitter, D-serine, a co-agonist of the NMDA receptor at the glycine-binding site, can be released by astrocytes in a calcium [Ca2+]i-dependent manner. A typical feature of astrocytes is their high expression level of connexin43 (Cx43), a protein forming gap junction channels and hemichannels associated with dynamic neuroglial interactions. Pharmacological and genetic inhibition of Cx43 hemichannel activity reduced the amplitude of NMDA EPSCs in mouse layer 5 prefrontal cortex pyramidal neurons without affecting AMPA EPSC currents. This reduction of NMDA EPSCs was rescued by addition of D-serine in the extracellular medium. LTP of NMDA and AMPA EPSCs after high-frequency stimulation was reduced by prior inhibition of Cx43 hemichannel activity. Inactivation of D-serine synthesis within the astroglial network resulted in the reduction of NMDA EPSCs, which was rescued by adding extracellular D-serine. We showed that the activity of Cx43 hemichannels recorded in cultured astrocytes was [Ca2+]I dependent. Accordingly, in acute cortical slices, clamping [Ca2+]i at a low level in astroglial network resulted in an inhibition of NMDA EPSC potentiation that was rescued by adding extracellular D-serine. This work demonstrates that astroglial Cx43 hemichannel activity is associated with D-serine release. This process, occurring by direct permeation of D-serine through hemichannels or indirectly by Ca2+ entry and activation of other [Ca2+]i-dependent mechanisms results in the modulation of synaptic activity and plasticity.SIGNIFICANCE STATEMENT We recorded neuronal glutamatergic (NMDA and AMPA) responses in prefrontal cortex (PFC) neurons and used pharmacological and genetic interventions to block connexin-mediated hemichannel activity specifically in a glial cell population. For the first time in astrocytes, we demonstrated that hemichannel activity depends on the intracellular calcium concentration and is associated with D-serine release. Blocking hemichannel activity reduced the LTP of these excitatory synaptic currents triggered by high-frequency stimulation. These observations may be particularly relevant in the PFC, where D-serine and its converting enzyme are highly expressed.
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Umino A, Ishiwata S, Iwama H, Nishikawa T. Evidence for Tonic Control by the GABA A Receptor of Extracellular D-Serine Concentrations in the Medial Prefrontal Cortex of Rodents. Front Mol Neurosci 2017; 10:240. [PMID: 28824371 PMCID: PMC5539225 DOI: 10.3389/fnmol.2017.00240] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2017] [Accepted: 07/17/2017] [Indexed: 11/18/2022] Open
Abstract
Endogenous D-serine is a putative dominant co-agonist for the N-methyl-D-aspartate glutamate receptor (NMDAR) in the mammalian forebrain. Although the NMDAR regulates the higher order brain functions by interacting with various neurotransmitter systems, the possible interactions between D-serine and an extra-glutamatergic system largely remain elusive. For the first time, we show in the rat and mouse using an in vivo microdialysis technique that the extracellular D-serine concentrations are under tonic increasing control by a major inhibitory transmitter, GABA, via the GABAA (GABAAR) in the medial prefrontal cortex (mPFC). Thus, an intra-mPFC infusion of a selective GABAAR antagonist, bicuculline (BIC), caused a concentration-dependent and reversible decrease in the extracellular levels of D-serine in the rat mPFC without affecting those of another intrinsic NMDAR coagonist, glycine and an NMDAR agonist, L-glutamate. The decreasing effects of BIC were eliminated by co-infusion of a selective GABAA agonist, muscimol (MUS) and were mimicked by a GABAA antagonist, gabazine (GBZ). In contrast, selective blockade of the GABAB or homomeric ρGABAA (formerly GABAC) receptor by saclofen or (1,2,5,6-tetrahydropyridin-4-yl)-methylphosphinic acid (TPMPA), respectively, failed to downregulate the prefrontal extracellular D-serine levels. Moreover, the local BIC application attenuated the ability of NMDA given to the mPFC to increase the cortical extracellular concentrations of taurine, indicating the hypofunction of the NMDAR. Finally, in the mouse mPFC, the reduction of the extracellular D-serine levels by a local injection of BIC into the prefrontal portion was replicated, and was precluded by inhibition of the neuronal or glial activity by co-local injection with tetrodotoxin (TTX) or fluorocitrate (Fluo), respectively. These findings suggest that the GABAAR-mediated regulation of the D-serine signaling may exert fine-tuning of the NMDAR function and require both neuronal and glial activities in the mammalian mPFC.
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Affiliation(s)
- Asami Umino
- Department of Psychiatry and Behavioral Sciences, Tokyo Medical and Dental UniversityTokyo, Japan.,Center for Brain Integration Research, Tokyo Medical and Dental UniversityTokyo, Japan
| | - Sayuri Ishiwata
- Department of Psychiatry and Behavioral Sciences, Tokyo Medical and Dental UniversityTokyo, Japan.,Center for Brain Integration Research, Tokyo Medical and Dental UniversityTokyo, Japan
| | - Hisayuki Iwama
- Department of Psychiatry and Behavioral Sciences, Tokyo Medical and Dental UniversityTokyo, Japan.,Center for Brain Integration Research, Tokyo Medical and Dental UniversityTokyo, Japan
| | - Toru Nishikawa
- Department of Psychiatry and Behavioral Sciences, Tokyo Medical and Dental UniversityTokyo, Japan.,Center for Brain Integration Research, Tokyo Medical and Dental UniversityTokyo, Japan
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Liu J, Saponjian Y, Mahoney MM, Staley KJ, Berdichevsky Y. Epileptogenesis in organotypic hippocampal cultures has limited dependence on culture medium composition. PLoS One 2017; 12:e0172677. [PMID: 28225808 PMCID: PMC5321418 DOI: 10.1371/journal.pone.0172677] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Accepted: 02/08/2017] [Indexed: 01/10/2023] Open
Abstract
Rodent organotypic hippocampal cultures spontaneously develop epileptiform activity after approximately 2 weeks in vitro and are increasingly used as a model of chronic post-traumatic epilepsy. However, organotypic cultures are maintained in an artificial environment (culture medium), which contains electrolytes, glucose, amino acids and other components that are not present at the same concentrations in cerebrospinal fluid (CSF). Therefore, it is possible that epileptogenesis in organotypic cultures is driven by these components. We examined the influence of medium composition on epileptogenesis. Epileptogenesis was evaluated by measurements of lactate and lactate dehydrogenase (LDH) levels (biomarkers of ictal activity and cell death, respectively) in spent culture media, immunohistochemistry and automated 3-D cell counts, and extracellular recordings from CA3 regions. Changes in culture medium components moderately influenced lactate and LDH levels as well as electrographic seizure burden and cell death. However, epileptogenesis occurred in any culture medium that was capable of supporting neural survival. We conclude that medium composition is unlikely to be the cause of epileptogenesis in the organotypic hippocampal culture model of chronic post-traumatic epilepsy.
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Affiliation(s)
- Jing Liu
- Department of Electrical and Computer Engineering, Lehigh University, Bethlehem, Pennsylvania, United States of America
| | - Yero Saponjian
- Department of Neurology, Massachusetts General Hospital, Boston, Massachusetts, United States of America
- Harvard Medical School, Boston, Massachusetts, United States of America
| | - Mark M. Mahoney
- Bioengineering Program, Lehigh University, Bethlehem, Pennsylvania, United States of America
| | - Kevin J. Staley
- Department of Neurology, Massachusetts General Hospital, Boston, Massachusetts, United States of America
- Harvard Medical School, Boston, Massachusetts, United States of America
| | - Yevgeny Berdichevsky
- Department of Electrical and Computer Engineering, Lehigh University, Bethlehem, Pennsylvania, United States of America
- Bioengineering Program, Lehigh University, Bethlehem, Pennsylvania, United States of America
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26
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Real-Time Chiral Metabolic Monitoring of Single Cell Using Microchip Electrophoresis Coupled with Electrospray Ionization Mass Spectrometry. ChemistrySelect 2016. [DOI: 10.1002/slct.201600748] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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Chen Z, Huang W, Srinivas SR, Jones CR, Ganapathy V, Prasad PD. Serine Racemase and D-Serine Transport in Human Placenta and Evidence for a Transplacental Gradient for D-Serine in Humans. ACTA ACUST UNITED AC 2016; 11:294-303. [PMID: 15219883 DOI: 10.1016/j.jsgi.2004.02.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
OBJECTIVE To investigate the possible role of human placenta in providing D-serine to the developing fetus. METHODS Expression of serine racemase in placenta was determined by reverse transcriptase polymerase chain reaction and northern analysis and confirmed by subsequent cloning. The transport of D-serine by human ATB(0) was characterized by expressing the cloned cDNA transiently in mammalian cells using the vaccinia virus expression system. D-serine levels in maternal and fetal blood were measured by fluorescence high-performance liquid chromatography (HPLC) after derivatization of the amino acids with o-phthaldialdehyde and N-tertiary-butyloxycarbonyl-L-cysteine. RESULTS mRNA for serine racemase was detected in placenta. ATB(0) was capable of d-serine transport, and the transport process is obligatorily dependent on sodium (Na+) with a Na(+):substrate stoichiometry of 1:1 and saturable with a Michaelis-Menten constant of 310 +/- 30 microM. Furthermore, studies have shown that ATB(0) is not expressed in the maternal-facing brush border membrane of human placental syncytiotrophoblast. The circulating concentration of D-serine in maternal serum is 5.8 +/- 0.5 microM, and the corresponding value in the fetal serum is 14.6 +/- 1.2 microM, indicating a two- to three-fold higher concentration of D-serine in the fetus than in the mother. CONCLUSION We speculate that D-serine is synthesized in human placenta by the racemization of L-serine and that ATB(0), expressed on the basal membrane of the syncytiotrophoblast, mediates the efflux of D-serine into the fetal circulation in exchange for other amino acids in fetal blood.
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Affiliation(s)
- Zhong Chen
- Department of Biochemistry and Molecular Biology, Medical College of Georgia, 1120 Laney Walker Boulevard, Augusta, GA 30912-2100, USA
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Sánchez-López E, Marcos A, Ambrosio E, Marina ML, Crego AL. Enantioseparation of the constituents involved in the phenylalanine-tyrosine metabolic pathway by capillary electrophoresis tandem mass spectrometry. J Chromatogr A 2016; 1467:372-382. [PMID: 27371023 DOI: 10.1016/j.chroma.2016.06.053] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Revised: 06/10/2016] [Accepted: 06/16/2016] [Indexed: 02/07/2023]
Abstract
Catecholamines dopamine, norepinephrine, and epinephrine are well-known neurotransmitters playing different roles in the nervous and endocrine system. These compounds are biologically synthesized in the phenylalanine-tyrosine pathway which consists on the successive conversion of l-phenylalanine into l-tyrosine, l-3,4-dihydroxyphenylalanine (L-DOPA), dopamine, norepinephrine, and epinephrine. This work describes the development of an enantioselective CE-ESI-MS2 methodology enabling, for the first time, the simultaneous enantioseparation of all the constituents involved in the Phe-Tyr metabolic pathway, since all these compounds except dopamine are chiral. The developed method was based on the use of a dual CDs system formed by 180mM of methyl-β-CD and 40mM of 2-hydroxypropyl-β-CD dissolved in 2M formic acid (pH 1.2) and presented the advantage of avoiding the use of any time-consuming labelling procedure. LODs ranged from 40 to 150nM and the unequivocal identification of the compounds investigated was achieved through their MS2 spectra. The applicability of this methodology to the analysis of biological samples (rat plasma) was also demonstrated.
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Affiliation(s)
- Elena Sánchez-López
- Departamento de Química Analítica, Química Física e Ingeniería Química, Universidad de Alcalá, Ctra. Madrid-Barcelona, Km. 33.600, 28871 Alcalá de Henares, Madrid, Spain
| | - Alberto Marcos
- Departamento de Psicobiología, UNED, Juan del Rosal 10, Ciudad Universitaria, 28040 Madrid, Spain
| | - Emilio Ambrosio
- Departamento de Psicobiología, UNED, Juan del Rosal 10, Ciudad Universitaria, 28040 Madrid, Spain
| | - María Luisa Marina
- Departamento de Química Analítica, Química Física e Ingeniería Química, Universidad de Alcalá, Ctra. Madrid-Barcelona, Km. 33.600, 28871 Alcalá de Henares, Madrid, Spain
| | - Antonio L Crego
- Departamento de Química Analítica, Química Física e Ingeniería Química, Universidad de Alcalá, Ctra. Madrid-Barcelona, Km. 33.600, 28871 Alcalá de Henares, Madrid, Spain.
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Meunier CNJ, Dallérac G, Le Roux N, Sacchi S, Levasseur G, Amar M, Pollegioni L, Mothet JP, Fossier P. D-Serine and Glycine Differentially Control Neurotransmission during Visual Cortex Critical Period. PLoS One 2016; 11:e0151233. [PMID: 27003418 PMCID: PMC4803205 DOI: 10.1371/journal.pone.0151233] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Accepted: 02/25/2016] [Indexed: 12/18/2022] Open
Abstract
N-methyl-D-aspartate receptors (NMDARs) play a central role in synaptic plasticity. Their activation requires the binding of both glutamate and d-serine or glycine as co-agonist. The prevalence of either co-agonist on NMDA-receptor function differs between brain regions and remains undetermined in the visual cortex (VC) at the critical period of postnatal development. Here, we therefore investigated the regulatory role that d-serine and/or glycine may exert on NMDARs function and on synaptic plasticity in the rat VC layer 5 pyramidal neurons of young rats. Using selective enzymatic depletion of d-serine or glycine, we demonstrate that d-serine and not glycine is the endogenous co-agonist of synaptic NMDARs required for the induction and expression of Long Term Potentiation (LTP) at both excitatory and inhibitory synapses. Glycine on the other hand is not involved in synaptic efficacy per se but regulates excitatory and inhibitory neurotransmission by activating strychnine-sensitive glycine receptors, then producing a shunting inhibition that controls neuronal gain and results in a depression of synaptic inputs at the somatic level after dendritic integration. In conclusion, we describe for the first time that in the VC both D-serine and glycine differentially regulate somatic depolarization through the activation of distinct synaptic and extrasynaptic receptors.
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Affiliation(s)
- Claire N. J. Meunier
- Institut de Neuroscience Paris-Saclay (NeuroPSI), UMR 9197 CNRS-Université Paris-Sud, Bât 446, F-91405, Orsay cedex, France
| | - Glenn Dallérac
- Aix-Marseille University, CRN2M UMR7286 CNRS, 51 Bd Pierre Dramard, 13344, Marseille, France
| | - Nicolas Le Roux
- Institut de Neuroscience Paris-Saclay (NeuroPSI), UMR 9197 CNRS-Université Paris-Sud, Bât 446, F-91405, Orsay cedex, France
| | - Silvia Sacchi
- Dipartimento di Biotecnologie e Scienze della Vita, Università degli Studi dell’Insubria, via J.H. Dunant 3, Varese, Italy
- “The Protein Factory”, Centro Interuniversitario di Biotecnologie Proteiche, Politecnico di Milano, ICRM-CNR, Milano, Italy
- Università degli Studi dell’Insubria, via Mancinelli 7, Milano, Italy
| | - Grégoire Levasseur
- Aix-Marseille University, CRN2M UMR7286 CNRS, 51 Bd Pierre Dramard, 13344, Marseille, France
| | - Muriel Amar
- Institut de Neuroscience Paris-Saclay (NeuroPSI), UMR 9197 CNRS-Université Paris-Sud, Bât 446, F-91405, Orsay cedex, France
| | - Loredano Pollegioni
- Dipartimento di Biotecnologie e Scienze della Vita, Università degli Studi dell’Insubria, via J.H. Dunant 3, Varese, Italy
- “The Protein Factory”, Centro Interuniversitario di Biotecnologie Proteiche, Politecnico di Milano, ICRM-CNR, Milano, Italy
- Università degli Studi dell’Insubria, via Mancinelli 7, Milano, Italy
| | - Jean-Pierre Mothet
- Aix-Marseille University, CRN2M UMR7286 CNRS, 51 Bd Pierre Dramard, 13344, Marseille, France
- * E-mail: (PF); (JPM)
| | - Philippe Fossier
- Institut de Neuroscience Paris-Saclay (NeuroPSI), UMR 9197 CNRS-Université Paris-Sud, Bât 446, F-91405, Orsay cedex, France
- * E-mail: (PF); (JPM)
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Cabrera-Pastor A, Taoro-Gonzalez L, Felipo V. Hyperammonemia alters glycinergic neurotransmission and modulation of the glutamate-nitric oxide-cGMP pathway by extracellular glycine in cerebellum in vivo. J Neurochem 2016; 137:539-48. [PMID: 26875688 DOI: 10.1111/jnc.13579] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2015] [Revised: 02/01/2016] [Accepted: 02/03/2016] [Indexed: 01/14/2023]
Abstract
The glutamate-nitric oxide (NO)-cGMP pathway modulates some forms of learning. How glycine modulates this pathway is unclear. Glycine could modulate the pathway biphasically, enhancing its function through NMDA receptor activation or reducing it through glycine receptor activation. Chronic hyperammonemia impairs the glutamate-NO-cGMP pathway in the cerebellum and induces cognitive impairment. The possible alterations in hyperammonemia of glycinergic neurotransmission and of glutamate-NO-cGMP pathway modulation by glycine remain unknown. The aims were to assess, by in vivo microdialysis in cerebellum: (i) the effects of different glycine concentrations, administered through the microdialysis probe, on the glutamate-NO-cGMP pathway function; (ii) the effects of tonic glycine receptors activation on the pathway function, by blocking them with strychnine; (iii) whether hyperammonemia alters the pathway modulation by glycine; (iv) and whether hyperammonemia alters extracellular glycine concentration and/or glycine receptor membrane expression. In control rats, low glycine levels reduce the pathway function, likely by activating glycine receptors, while 20 μM glycine enhances the pathway function, likely by enhancing NMDA receptor activation. In hyperammonemic rats, glycine did not reduce the pathway function, but enhanced it when administered at 1-20 μM. Hyperammonemia reduces extracellular glycine concentration by approximately 50% and glycine receptor membrane expression. However, tonic glycine receptor activation seems to be enhanced in hyperammonemic rats, as indicated by the larger increase in extracellular cGMP induced by strychnine. These data show that glycine modulates the glutamate-NO-cGMP pathway biphasically and that hyperammonemia strongly alters glycinergic neurotransmission and modulation by glycine of the glutamate-NO-cGMP pathway. These alterations may contribute to the cerebellar aspects of cognitive alterations in hyperammonemia. The findings reported in this study show that hyperammonemia alters glycinergic neurotransmission and the glutamate-NO-cGMP pathway modulation by glycine. In control rats, low glycine levels reduced the pathway function, likely by activating glycine receptors, while 20 μM glycine enhanced the pathway, likely by enhancing NMDA receptor activation. In hyperammonemic rats, glycine (administered at 1-20 μM) enhances the pathway, likely by activating NMDA receptors.
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Affiliation(s)
- Andrea Cabrera-Pastor
- Laboratorio de Neurobiología, Centro Investigación Príncipe Felipe de Valencia, Valencia, Spain
| | - Lucas Taoro-Gonzalez
- Laboratorio de Neurobiología, Centro Investigación Príncipe Felipe de Valencia, Valencia, Spain
| | - Vicente Felipo
- Laboratorio de Neurobiología, Centro Investigación Príncipe Felipe de Valencia, Valencia, Spain
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Kiriyama Y, Nochi H. D-Amino Acids in the Nervous and Endocrine Systems. SCIENTIFICA 2016; 2016:6494621. [PMID: 28053803 PMCID: PMC5178360 DOI: 10.1155/2016/6494621] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Accepted: 11/14/2016] [Indexed: 05/12/2023]
Abstract
Amino acids are important components for peptides and proteins and act as signal transmitters. Only L-amino acids have been considered necessary in mammals, including humans. However, diverse D-amino acids, such as D-serine, D-aspartate, D-alanine, and D-cysteine, are found in mammals. Physiological roles of these D-amino acids not only in the nervous system but also in the endocrine system are being gradually revealed. N-Methyl-D-aspartate (NMDA) receptors are associated with learning and memory. D-Serine, D-aspartate, and D-alanine can all bind to NMDA receptors. H2S generated from D-cysteine reduces disulfide bonds in receptors and potentiates their activity. Aberrant receptor activity is related to diseases of the central nervous system (CNS), such as Alzheimer's disease, amyotrophic lateral sclerosis, and schizophrenia. Furthermore, D-amino acids are detected in parts of the endocrine system, such as the pineal gland, hypothalamus, pituitary gland, pancreas, adrenal gland, and testis. D-Aspartate is being investigated for the regulation of hormone release from various endocrine organs. Here we focused on recent findings regarding the synthesis and physiological functions of D-amino acids in the nervous and endocrine systems.
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Affiliation(s)
- Yoshimitsu Kiriyama
- Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University, Shido 1314-1, Sanuki, Kagawa 769-2193, Japan
| | - Hiromi Nochi
- Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University, Shido 1314-1, Sanuki, Kagawa 769-2193, Japan
- *Hiromi Nochi:
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Uversky VN. The intrinsic disorder alphabet. III. Dual personality of serine. INTRINSICALLY DISORDERED PROTEINS 2015; 3:e1027032. [PMID: 28232888 DOI: 10.1080/21690707.2015.1027032] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2015] [Revised: 02/16/2015] [Accepted: 03/02/2015] [Indexed: 12/23/2022]
Abstract
Proteins are natural polypeptides consisting of 20 major amino acid residues, content and order of which in a given amino acid sequence defines the ability of a related protein to fold into unique functional state or to stay intrinsically disordered. Amino acid sequences code for both foldable (ordered) proteins/domains and for intrinsically disordered proteins (IDPs) and IDP regions (IDPRs), but these sequence codes are dramatically different. This difference starts with a very general property of the corresponding amino acid sequences, namely, their compositions. IDPs/IDPRs are enriched in specific disorder-promoting residues, whereas amino acid sequences of ordered proteins/domains typically contain more order-promoting residues. Therefore, the relative abundances of various amino acids in ordered and disordered proteins can be used to scale amino acids according to their disorder promoting potentials. This review continues a series of publications on the roles of different amino acids in defining the phenomenon of protein intrinsic disorder and represents serine, which is the third most disorder-promoting residue. Similar to previous publications, this review represents some physico-chemical properties of serine and the roles of this residue in structures and functions of ordered proteins, describes major posttranslational modifications tailored to serine, and finally gives an overview of roles of serine in structure and functions of intrinsically disordered proteins.
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Affiliation(s)
- Vladimir N Uversky
- Department of Molecular Medicine and USF Health Byrd Alzheimer Research Institute; Morsani College of Medicine, University of South Florida; Tampa, FL USA; Biology Department; Faculty of Science, King Abdulaziz University; Jeddah, Kingdom of Saudi Arabia; Institute for Biological Instrumentation, Russian Academy of Sciences; Pushchino, Moscow Region, Russia; Laboratory of Structural Dynamics, Stability and Folding of Proteins; Institute of Cytology, Russian Academy of Sciences; St. Petersburg, Russia
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Cappelletti P, Piubelli L, Murtas G, Caldinelli L, Valentino M, Molla G, Pollegioni L, Sacchi S. Structure-function relationships in human d-amino acid oxidase variants corresponding to known SNPs. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2015; 1854:1150-9. [PMID: 25701391 DOI: 10.1016/j.bbapap.2015.02.005] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Revised: 02/05/2015] [Accepted: 02/07/2015] [Indexed: 12/11/2022]
Abstract
In the brain, d-amino acid oxidase plays a key role in modulating the N-methyl-d-aspartate receptor (NMDAR) activation state, catalyzing the stereospecific degradation of the coagonist d-serine. A relationship between d-serine signaling deregulation, NMDAR dysfunction, and CNS diseases is presumed. Notably, the R199W substitution in human DAAO (hDAAO) was associated with familial amyotrophic lateral sclerosis (ALS), and further coding substitutions, i.e., R199Q and W209R, were also deposited in the single nucleotide polymorphism database. Here, we investigated the biochemical properties of these different hDAAO variants. The W209R hDAAO variant shows an improved d-serine degradation ability (higher activity and affinity for the cofactor FAD) and produces a greater decrease in cellular d/(d+l) serine ratio than the wild-type counterpart when expressed in U87 cells. The production of H2O2 as result of excessive d-serine degradation by this hDAAO variant may represent the factor affecting cell viability after stable transfection. The R199W/Q substitution in hDAAO altered the protein conformation and enzymatic activity was lost under conditions resembling the cellular ones: this resulted in an abnormal increase in cellular d-serine levels. Altogether, these results indicate that substitutions that affect hDAAO functionality directly impact on d-serine cellular levels (at least in the model cell system used). The pathological effect of the expression of the R199W hDAAO, as observed in familial ALS, originates from both protein instability and a decrease in kinetic efficiency: the increase in synaptic d-serine may be mainly responsible for the neurotoxic effect. This information is expected to drive future targeted treatments.
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Affiliation(s)
- 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, ICMR-CNR, Università degli Studi dell'Insubria, via Mancinelli 7, 20131 Milano, Italy
| | - Luciano Piubelli
- 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, ICMR-CNR, Università degli Studi dell'Insubria, via Mancinelli 7, 20131 Milano, Italy
| | - 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, ICMR-CNR, Università degli Studi dell'Insubria, via Mancinelli 7, 20131 Milano, Italy
| | - Mattia Valentino
- The Protein Factory, Politecnico di Milano, ICMR-CNR, Università degli Studi dell'Insubria, via Mancinelli 7, 20131 Milano, Italy; CNR, Istituto di Chimica del Riconoscimento Molecolare, Sezione Adolfo Quilico, via M. Bianchi 9, 20131 Milano, Italy
| | - Gianluca Molla
- 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, ICMR-CNR, Università degli Studi dell'Insubria, via Mancinelli 7, 20131 Milano, 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, ICMR-CNR, Università degli Studi dell'Insubria, via Mancinelli 7, 20131 Milano, 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, ICMR-CNR, Università degli Studi dell'Insubria, via Mancinelli 7, 20131 Milano, Italy.
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Novel human D-amino acid oxidase inhibitors stabilize an active-site lid-open conformation. Biosci Rep 2014; 34:BSR20140071. [PMID: 25001371 PMCID: PMC4127593 DOI: 10.1042/bsr20140071] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
The NMDAR (N-methyl-D-aspartate receptor) is a central regulator of synaptic plasticity and learning and memory. hDAAO (human D-amino acid oxidase) indirectly reduces NMDAR activity by degrading the NMDAR co-agonist D-serine. Since NMDAR hypofunction is thought to be a foundational defect in schizophrenia, hDAAO inhibitors have potential as treatments for schizophrenia and other nervous system disorders. Here, we sought to identify novel chemicals that inhibit hDAAO activity. We used computational tools to design a focused, purchasable library of compounds. After screening this library for hDAAO inhibition, we identified the structurally novel compound, 'compound 2' [3-(7-hydroxy-2-oxo-4-phenyl-2H-chromen-6-yl)propanoic acid], which displayed low nM hDAAO inhibitory potency (Ki=7 nM). Although the library was expected to enrich for compounds that were competitive for both D-serine and FAD, compound 2 actually was FAD uncompetitive, much like canonical hDAAO inhibitors such as benzoic acid. Compound 2 and an analog were independently co-crystalized with hDAAO. These compounds stabilized a novel conformation of hDAAO in which the active-site lid was in an open position. These results confirm previous hypotheses regarding active-site lid flexibility of mammalian D-amino acid oxidases and could assist in the design of the next generation of hDAAO inhibitors.
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Saitoh A, Ohashi M, Suzuki S, Tsukagoshi M, Sugiyama A, Yamada M, Oka JI, Inagaki M, Yamada M. Activation of the prelimbic medial prefrontal cortex induces anxiety-like behaviors via N-Methyl-D-aspartate receptor-mediated glutamatergic neurotransmission in mice. J Neurosci Res 2014; 92:1044-53. [DOI: 10.1002/jnr.23391] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2013] [Revised: 03/11/2014] [Accepted: 03/13/2014] [Indexed: 12/19/2022]
Affiliation(s)
- Akiyoshi Saitoh
- Department of Neuropsychopharmacology; National Institute of Mental Health, National Center of Neurology and Psychiatry; Tokyo Japan
| | - Masanori Ohashi
- Department of Neuropsychopharmacology; National Institute of Mental Health, National Center of Neurology and Psychiatry; Tokyo Japan
- Laboratory of Pharmacology; Faculty of Pharmaceutical Sciences; Tokyo University of Science; Chiba Japan
| | - Satoshi Suzuki
- Department of Neuropsychopharmacology; National Institute of Mental Health, National Center of Neurology and Psychiatry; Tokyo Japan
- Laboratory of Pharmacology; Faculty of Pharmaceutical Sciences; Tokyo University of Science; Chiba Japan
| | - Mai Tsukagoshi
- Department of Neuropsychopharmacology; National Institute of Mental Health, National Center of Neurology and Psychiatry; Tokyo Japan
- Laboratory of Pharmacology; Faculty of Pharmaceutical Sciences; Tokyo University of Science; Chiba Japan
| | - Azusa Sugiyama
- Department of Neuropsychopharmacology; National Institute of Mental Health, National Center of Neurology and Psychiatry; Tokyo Japan
- Laboratory of Pharmacology; Faculty of Pharmaceutical Sciences; Tokyo University of Science; Chiba Japan
| | - Misa Yamada
- Department of Neuropsychopharmacology; National Institute of Mental Health, National Center of Neurology and Psychiatry; Tokyo Japan
| | - Jun-Ichiro Oka
- Laboratory of Pharmacology; Faculty of Pharmaceutical Sciences; Tokyo University of Science; Chiba Japan
| | - Masatoshi Inagaki
- Department of Neuropsychiatry; Okayama University Hospital; Okayama Japan
| | - Mitsuhiko Yamada
- Department of Neuropsychopharmacology; National Institute of Mental Health, National Center of Neurology and Psychiatry; Tokyo Japan
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Modulation of extracellular d-serine content by calcium permeable AMPA receptors in rat medial prefrontal cortex as revealed by in vivo microdialysis. Int J Neuropsychopharmacol 2013; 16:1395-406. [PMID: 23298512 DOI: 10.1017/s1461145712001484] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
In mammalian brains, d-serine has been shown to be required for the regulation of glutamate neurotransmission as an endogenous co-agonist for the N-methyl-d-aspartate type glutamate receptor that is essential for the expression of higher-order brain functions. The exact control mechanisms for the extracellular d-serine dynamics, however, await further elucidation. To obtain an insight into this issue, we have characterized the effects of agents acting at the α-amino-3-hydroxy-5-methyl-4-isoxazolepropioinic acid (AMPA) type glutamate receptor on the extracellular d-serine contents in the medial prefrontal cortex of freely moving rats by an in vivo microdialysis technique in combination with high-performance liquid chromatography with fluorometric detection. In vivo experiments are needed in terms of a crucial role of d-serine in the neuron-glia communications despite the previous in vitro studies on AMPA receptor-d-serine interactions using the separated preparations of neurons or glial cells. Here, we show that the intra-cortical infusion of (S)-AMPA, an active enantiomer at the AMPA receptor, causes a significant and concentration-dependent reduction in the prefrontal extracellular contents of d-serine, which is reversed by an AMPA/kainate receptor antagonist, 2,3-dioxo-6-nitro-1,2,3,4-tetrahydrobenzo[f]quinoxaline-7-sulfonamide disodium salt, and a calcium permeable AMPA receptor antagonist, 1-naphthyl acetyl spermine. The d-serine reducing effects of (S)-AMPA are augmented by co-infusion of cyclothiazide that prevents AMPA receptor desensitization. Our data support the view that a calcium permeable AMPA receptor subtype may exert a phasic inhibitory control on the extracellular d-serine release in the mammalian prefrontal cortex in vivo.
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Billard JM. Serine racemase as a prime target for age-related memory deficits. Eur J Neurosci 2013; 37:1931-8. [DOI: 10.1111/ejn.12226] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2012] [Revised: 02/26/2013] [Accepted: 03/22/2013] [Indexed: 11/29/2022]
Affiliation(s)
- J.-M. Billard
- Centre de Psychiatrie et Neurosciences; Faculté de Médecine; Université Paris Descartes; UMR 894; Sorbonne Paris Cité; 2 ter rue d'Alésia; Paris; 75014; France
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Fliegel S, Brand I, Spanagel R, Noori HR. Ethanol-induced alterations of amino acids measured by in vivo microdialysis in rats: a meta-analysis. In Silico Pharmacol 2013; 1:7. [PMID: 25505652 PMCID: PMC4230485 DOI: 10.1186/2193-9616-1-7] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2013] [Accepted: 05/07/2013] [Indexed: 12/14/2022] Open
Abstract
PURPOSE In recent years in vivo microdialysis has become an important method in research studies investigating the alterations of neurotransmitters in the extracellular fluid of the brain. Based on the major involvement of glutamate and γ-aminobutyric acid (GABA) in mediating a variety of alcohol effects in the mammalian brain, numerous microdialysis studies have focused on the dynamical behavior of these systems in response to alcohol. METHODS Here we performed multiple meta-analyses on published datasets from the rat brain: (i) we studied basal extracellular concentrations of glutamate and GABA in brain regions that belong to a neurocircuitry involved in neuropsychiatric diseases, especially in alcoholism (Noori et al., Addict Biol 17:827-864, 2012); (ii) we examined the effect of acute ethanol administration on glutamate and GABA levels within this network and (iii) we studied alcohol withdrawal-induced alterations in glutamate and GABA levels within this neurocircuitry. RESULTS For extraction of basal concentrations of these neurotransmitters, datasets of 6932 rats were analyzed and the absolute basal glutamate and GABA levels were estimated for 18 different brain sites. In response to different doses of acute ethanol administration, datasets of 529 rats were analyzed and a non-linear dose response (glutamate and GABA release) relationship was observed in several brain sites. Specifically, glutamate in the nucleus accumbens shows a decreasing logarithmic dose response curve. Finally, regression analysis of 11 published reports employing brain microdialysis experiments in 104 alcohol-dependent rats reveals very consistent augmented extracellular glutamate and GABA levels in various brain sites that correlate with the intensity of the withdrawal response were identified. CONCLUSIONS In summary, our results provide standardized basal values for future experimental and in silico studies on neurotransmitter release in the rat brain and may be helpful to understand the effect of ethanol on neurotransmitter release. Furthermore, this study illustrates the benefit of meta-analyses using the generalization of a wide range of preclinical data.
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Affiliation(s)
- Sarah Fliegel
- Institute of Psychopharmacology, Central Institute of Mental Health, Faculty of Medicine Mannheim, University of Heidelberg, J5, 68159 Mannheim, Germany
| | - Ines Brand
- Institute of Psychopharmacology, Central Institute of Mental Health, Faculty of Medicine Mannheim, University of Heidelberg, J5, 68159 Mannheim, Germany
| | - Rainer Spanagel
- Institute of Psychopharmacology, Central Institute of Mental Health, Faculty of Medicine Mannheim, University of Heidelberg, J5, 68159 Mannheim, Germany
| | - Hamid R Noori
- Institute of Psychopharmacology, Central Institute of Mental Health, Faculty of Medicine Mannheim, University of Heidelberg, J5, 68159 Mannheim, Germany
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Maucler C, Pernot P, Vasylieva N, Pollegioni L, Marinesco S. In vivo D-serine hetero-exchange through alanine-serine-cysteine (ASC) transporters detected by microelectrode biosensors. ACS Chem Neurosci 2013; 4:772-81. [PMID: 23581544 DOI: 10.1021/cn4000549] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
D-serine, a co-agonist of N-methyl D-aspartate (NMDA) receptors, has been implicated in neurological and psychiatric disorders such as cerebral ischemia, lateral amyotrophic sclerosis, or schizophrenia. D-serine signaling represents an important pharmacological target for treating these diseases; however, the biochemical mechanisms controlling extracellular D-serine levels in vivo are still unclear. D-serine heteroexchange through small neutral amino acid transporters has been shown in cell cultures and brain slices and could provide a biochemical mechanism for the control of D-serine extracellular concentration in vivo. Alternatively, exocytotic D-serine release has also been proposed. In this study, the dynamics of D-serine release and clearance were explored in vivo on a second-by-second time scale using microelectrode biosensors. The rate of D-serine clearance in the rat frontal cortex after a microionophoretic injection revealed a transporter-mediated uptake mechanism. D-serine uptake was blocked by small neutral l-amino acids, implicating alanine-serine-cysteine (ASC) transporters, in particular high affinity Asc-1 and low affinity ASCT2 transporters. Interestingly, changes in alanine, serine, or threonine levels resulted in D-serine release through ASC transporters. Asc-1, but not ASCT2, appeared to release D-serine in response to changes in amino acid concentrations. Finally, neuronal silencing by tetrodotoxin increased D-serine extracellular concentration by an ASC-transporter-dependent mechanism. Together, these results indicate that D-serine heteroexchange through ASC transporters is present in vivo and may constitute a key component in the regulation of D-serine extracellular concentration.
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Affiliation(s)
- Caroline Maucler
- INSERM U1028; CNRS UMR5292 Lyon Neuroscience Research Center, AniRA-Neurochem technological platform, team WAKING, Lyon F-69000, France
- Université Claude Bernard Lyon 1, Lyon F-69000, France
| | - Pierre Pernot
- INSERM U1028; CNRS UMR5292 Lyon Neuroscience Research Center, AniRA-Neurochem technological platform, team WAKING, Lyon F-69000, France
- Université Claude Bernard Lyon 1, Lyon F-69000, France
| | - Natalia Vasylieva
- INSERM U1028; CNRS UMR5292 Lyon Neuroscience Research Center, AniRA-Neurochem technological platform, team WAKING, Lyon F-69000, France
- Université Claude Bernard Lyon 1, Lyon F-69000, France
- Institut de nanotechnologie de Lyon, CNRS UMR-5270, INSA de Lyon, France
| | - Loredano Pollegioni
- Dipartimento di Biotecnologie e Scienze della Vita, Università degli studi dell’Insubria, Varese, Italy
- “The Protein Factory”, Centro Interuniversitario di Ricerca in Biotecnologie Proteiche ICRM-CNR Milano, Politecnico di Milano and Università degli studi dell’Insubria, Italy
| | - Stéphane Marinesco
- INSERM U1028; CNRS UMR5292 Lyon Neuroscience Research Center, AniRA-Neurochem technological platform, team WAKING, Lyon F-69000, France
- Université Claude Bernard Lyon 1, Lyon F-69000, France
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Ishiwata S, Ogata S, Umino A, Shiraku H, Ohashi Y, Kajii Y, Nishikawa T. Increasing effects of S-methyl-L-cysteine on the extracellular D-serine concentrations in the rat medial frontal cortex. Amino Acids 2013; 44:1391-5. [PMID: 23417484 DOI: 10.1007/s00726-013-1464-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2012] [Accepted: 01/23/2013] [Indexed: 02/06/2023]
Abstract
In an in vivo dialysis experiment, the intra-medial frontal cortex infusion of a system A and Asc-1 transporter inhibitor, S-methyl-L-cysteine, caused a concentration-dependent increase in the dialysate contents of an endogenous coagonist for the N-methyl-D-aspartate (NMDA) type glutamate receptor, D-serine, in the cortical portion. These results suggest that these neutral amino acid transporters could control the extracellular D-serine signaling in the brain and be a target for the development of a novel threapy for neuropsychiatric disorders with an NMDA receptor dysfunction.
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Affiliation(s)
- Sayuri Ishiwata
- Department of Psychiatry and Behavioral Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo 113-8519, Japan
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Tanahashi S, Yamamura S, Nakagawa M, Motomura E, Okada M. Clozapine, but not haloperidol, enhances glial D-serine and L-glutamate release in rat frontal cortex and primary cultured astrocytes. Br J Pharmacol 2012; 165:1543-55. [PMID: 21880034 DOI: 10.1111/j.1476-5381.2011.01638.x] [Citation(s) in RCA: 117] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
BACKGROUND AND PURPOSE Deficient transmission at the glutamate NMDA receptor is considered a key component of the pathophysiology of schizophrenia. However, the effects of antipsychotic drugs on the release of the endogenous NMDA receptor partial agonist, D-serine, remain to be clarified. EXPERIMENTAL APPROACH We determined the interaction between antipsychotic drugs (clozapine and haloperidol) and transmission-modulating toxins (tetanus toxin, fluorocitrate, tetrodotoxin) on the release of L-glutamate and D-serine in the medial prefrontal cortex (mPFC) of freely moving rats, using microdialysis, and primary cultures of astrocytes using extreme high-pressure liquid chromatography. KEY RESULTS Release of L-glutamate and D-serine in the mPFC and in cultured astrocytes was inhibited by tetanus toxin (a synaptobrevin inhibitor) and fluorocitrate (a glial toxin), whereas tetrodotoxin (a voltage-sensitive Na(+) blocker) inhibited depolarization-induced L-glutamate release in the mPFC without affecting that of D-serine. Clozapine (1 and 5 mg·kg(-1)), but not haloperidol (0.5 and 1 mg·kg(-1)), dose-dependently increased L-glutamate and D-serine release from both astrocytes and mPFC. Clozapine-induced release of L-glutamate and D-serine was also reduced by tetanus toxin and fluorocitrate. Tetrodotoxin reduced clozapine-induced mPFC L-glutamate release but not that of D-serine. Clozapine-induced L-glutamate release preceded clozapine-induced D-serine release. MK-801 (a NMDA receptor antagonist) inhibited the delayed clozapine-induced L-glutamate release without affecting that of D-serine. CONCLUSIONS AND IMPLICATIONS Clozapine predominantly activated glial exocytosis of D-serine, and this clozapine-induced D-serine release subsequently enhances neuronal L-glutamate release via NMDA receptor activation. The enhanced D-serine associated glial transmission seems a novel mechanism of action of clozapine but not haloperidol.
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Affiliation(s)
- Shunske Tanahashi
- Department of Psychiatry, Division of Neuroscience, Graduate School of Medicine, Brain Science and Animal Model Research Center, Mie University, 2-174 Edobashi, Tsu, Mie, Japan
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Billard JM. d-Amino acids in brain neurotransmission and synaptic plasticity. Amino Acids 2012; 43:1851-60. [DOI: 10.1007/s00726-012-1346-3] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2012] [Accepted: 06/16/2012] [Indexed: 01/25/2023]
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43
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Mohd Zain Z, Ab Ghani S, O’Neill RD. Amperometric microbiosensor as an alternative tool for investigation of d-serine in brain. Amino Acids 2012; 43:1887-94. [DOI: 10.1007/s00726-012-1365-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2012] [Accepted: 07/06/2012] [Indexed: 12/23/2022]
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Pernot P, Maucler C, Tholance Y, Vasylieva N, Debilly G, Pollegioni L, Cespuglio R, Marinesco S. d-Serine diffusion through the blood-brain barrier: effect on d-serine compartmentalization and storage. Neurochem Int 2012; 60:837-45. [PMID: 22465696 DOI: 10.1016/j.neuint.2012.03.008] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2012] [Revised: 03/08/2012] [Accepted: 03/13/2012] [Indexed: 11/17/2022]
Abstract
d-Serine is a co-agonist of N-methyl-d-aspartate (NMDA) receptors. It has been implicated in the etiology of schizophrenia and has shown efficacy as an adjuvant to reduce positive and negative symptoms of schizophrenia. In addition, d-serine can modulate cognition in animals when administered alone. However, the neurochemical effects of exogenous d-serine on extra- and intra-cellular d-serine brain levels are poorly understood. In this study, we used both high performance liquid chromatography (HPLC) and enzyme-based microelectrode biosensors to quantify d-serine in the rat brain. We demonstrated levels of 2.3-2.8μM in the extracellular medium, 4μM in plasma and 188pmol/mg in brain tissue samples. An intraperitoneal (i.p.) d-serine injection (1g/kg) produced a slow increase in extracellular d-serine concentration in the cortex despite a surge in d-serine up to 13mM in the plasma, indicating poor diffusion through the blood-brain barrier. Using the respective volume fractions of blood, extracellular and intracellular spaces published in the literature, we estimated that d-serine intracellular stores represented more than 99% of total d-serine. These intracellular stores almost doubled 3h after d-serine administration. Overall, our data indicate that d-serine administration increases brain extra- and intra-cellular concentrations despite weak diffusion through the blood-brain barrier. These results pave the way for a better understanding of the neurochemical mechanisms by which d-serine administration modulates cognition.
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Affiliation(s)
- Pierre Pernot
- Lyon Neuroscience Research Center, Plate-forme technologique AniRA-Neurochem, Team WAKE, Lyon F-69000, France
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Coactivation of NMDA receptors by glutamate and D-serine induces dilation of isolated middle cerebral arteries. J Cereb Blood Flow Metab 2012; 32:537-47. [PMID: 22068228 PMCID: PMC3293118 DOI: 10.1038/jcbfm.2011.161] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
N-methyl-D-aspartate (NMDA) receptors are glutamate-gated cation channels that mediate excitatory neurotransmission in the central nervous system. In addition to glutamate, NMDA receptors are also activated by coagonist binding of the gliotransmitter, D-serine. Neuronal NMDA receptors mediate activity-dependent blood flow regulation in the brain. Our objective was to determine whether NMDA receptors expressed by brain endothelial cells can induce vasodilation of isolated brain arteries. Adult mouse middle cerebral arteries (MCAs) were isolated, pressurized, and preconstricted with norepinephrine. N-methyl-D-aspartate receptor agonists, glutamate and NMDA, significantly dilated MCAs in a concentration-dependent manner in the presence of D-serine but not alone. Dilation was significantly inhibited by NMDA receptor antagonists, D-2-amino-5-phosphonopentanoate and 5,7-dichlorokynurenic acid, indicating a response dependent on NMDA receptor glutamate and D-serine binding sites, respectively. Vasodilation was inhibited by denuding the endothelium and by selective inhibition or genetic knockout of endothelial nitric oxide synthase (eNOS). We also found evidence for expression of the pan-NMDA receptor subunit, NR1, in mouse primary brain endothelial cells, and for the NMDA receptor subunit NR2C in cortical arteries in situ. Overall, we conclude that NMDA receptor coactivation by glutamate and D-serine increases lumen diameter in pressurized MCA in an endothelial and eNOS-dependent mechanism.
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46
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Astrocyte calcium signaling transforms cholinergic modulation to cortical plasticity in vivo. J Neurosci 2012; 31:18155-65. [PMID: 22159127 DOI: 10.1523/jneurosci.5289-11.2011] [Citation(s) in RCA: 295] [Impact Index Per Article: 24.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Global brain state dynamics regulate plasticity in local cortical circuits, but the underlying cellular and molecular mechanisms are unclear. Here, we demonstrate that astrocyte Ca(2+) signaling provides a critical bridge between cholinergic activation, associated with attention and vigilance states, and somatosensory plasticity in mouse barrel cortex in vivo. We investigated first whether a combined stimulation of mouse whiskers and the nucleus basalis of Meynert (NBM), the principal source of cholinergic innervation to the cortex, leads to enhanced whisker-evoked local field potential. This plasticity is dependent on muscarinic acetylcholine receptors (mAChR) and N-methyl-d-aspartic acid receptors (NMDARs). During the induction of this synaptic plasticity, we find that astrocytic [Ca(2+)](i) is pronouncedly elevated, which is blocked by mAChR antagonists. The elevation of astrocytic [Ca(2+)](i) is crucial in this type of synaptic plasticity, as the plasticity could not be induced in inositol-1,4,5-trisphosphate receptor type 2 knock-out (IP(3)R2-KO) mice, in which astrocytic [Ca(2+)](i) surges are diminished. Moreover, NBM stimulation led to a significant increase in the extracellular concentration of the NMDAR coagonist d-serine in wild-type mice when compared to IP(3)R2-KO mice. Finally, plasticity in IP(3)R2-KO mice could be rescued by externally supplying d-serine. Our data present coherent lines of in vivo evidence for astrocytic involvement in cortical plasticity. These findings suggest an unexpected role of astrocytes as a gate for cholinergic plasticity in the cortex.
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Cao H, Ren WH, Zhu MY, Zhao ZQ, Zhang YQ. Activation of glycine site and GluN2B subunit of NMDA receptors is necessary for ERK/CREB signaling cascade in rostral anterior cingulate cortex in rats: implications for affective pain. Neurosci Bull 2012; 28:77-87. [PMID: 22233892 PMCID: PMC5560288 DOI: 10.1007/s12264-012-1060-x] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2011] [Accepted: 12/08/2011] [Indexed: 11/30/2022] Open
Abstract
OBJECTIVE The rostral anterior cingulate cortex (rACC) is implicated in processing the emotional component of pain. N-methyl-D-aspartate receptors (NMDARs) are highly expressed in the rACC and mediate pain-related affect by activating a signaling pathway that involves cyclic adenosine monophosphate (cAMP)/protein kinase A (PKA) and/or extracellular regulated kinase (ERK)/cAMP-response element-binding protein (CREB). The present study investigated the contributions of the NMDAR glycine site and GluN2B subunit to the activation of ERK and CREB both in vitro and in vivo in rat rACC. METHODS Immunohistochemistry and Western blot analysis were used to separately assess the expression of phospho-ERK (pERK) and phospho-CREB (pCREB) in vitro and in vivo. Double immunostaining was also used to determine the colocalization of pERK and pCREB. RESULTS Both bath application of NMDA in brain slices in vitro and intraplantar injection of formalin into the rat hindpaw in vivo induced significant up-regulation of pERK and pCREB in the rACC, which was inhibited by the NMDAR antagonist DL-2-amino-5-phospho-novaleric acid. Selective blockade of the NMDAR GluN2B subunit and the glycine-binding site, or degradation of endogenous D-serine, a co-agonist for the glycine site, significantly decreased the up-regulation of pERK and pCREB expression in the rACC. Further, the activated ERK predominantly colocalized with CREB. CONCLUSION Either the glycine site or the GluN2B subunit of NMDARs participates in the phosphorylation of ERK and CREB induced by bath application of NMDA in brain slices or hindpaw injection of 5% formalin in rats, and these might be fundamental molecular mechanisms underlying pain affect.
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Affiliation(s)
- Hong Cao
- Institutes of Neurobiology, Institute of Brain Science and State Key Laboratory of Medical Neurobiology, Shanghai Medical College, Fudan University, Shanghai, 200032 China
| | - Wen-Hua Ren
- Institutes of Neurobiology, Institute of Brain Science and State Key Laboratory of Medical Neurobiology, Shanghai Medical College, Fudan University, Shanghai, 200032 China
| | - Mu-Ye Zhu
- Department of Life Science, Fudan University, Shanghai, 200433 China
| | - Zhi-Qi Zhao
- Institutes of Neurobiology, Institute of Brain Science and State Key Laboratory of Medical Neurobiology, Shanghai Medical College, Fudan University, Shanghai, 200032 China
| | - Yu-Qiu Zhang
- Institutes of Neurobiology, Institute of Brain Science and State Key Laboratory of Medical Neurobiology, Shanghai Medical College, Fudan University, Shanghai, 200032 China
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Thompson M, Marecki JC, Marinesco S, Labrie V, Roder JC, Barger SW, Crow JP. Paradoxical roles of serine racemase and D-serine in the G93A mSOD1 mouse model of amyotrophic lateral sclerosis. J Neurochem 2012; 120:598-610. [PMID: 22117694 DOI: 10.1111/j.1471-4159.2011.07601.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
D-serine is an endogenous neurotransmitter that binds to the NMDA receptor, thereby increasing the affinity for glutamate, and the potential for excitotoxicity. The primary source of D-serine in vivo is enzymatic racemization by serine racemase (SR). Regulation of D-serine in vivo is poorly understood, but is thought to involve a combination of controlled production, synaptic reuptake by transporters, and intracellular degradation by D-amino acid oxidase (DAO). However, SR itself possesses a well-characterized eliminase activity, which effectively degrades D-serine as well. D-serine is increased two-fold in spinal cords of G93A Cu,Zn-superoxide dismutase (SOD1) mice--the standard model of amyotrophic lateral sclerosis (ALS). ALS mice with SR disruption show earlier symptom onset, but survive longer (progression phase is slowed), in an SR-dependent manner. Paradoxically, administration of D-serine to ALS mice dramatically lowers cord levels of D-serine, leading to changes in the onset and survival very similar to SR deletion. D-serine treatment also increases cord levels of the alanine-serine-cysteine transporter 1 (Asc-1). Although the mechanism by which SOD1 mutations increases D-serine is not known, these results strongly suggest that SR and D-serine are fundamentally involved in both the pre-symptomatic and progression phases of disease, and offer a direct link between mutant SOD1 and a glial-derived toxic mediator.
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Affiliation(s)
- Misty Thompson
- Department of Pharmacology and Toxicology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
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Daniels BA, Wood L, Tremblay F, Baldridge WH. Functional evidence for D-serine inhibition of non-N-methyl-D-aspartate ionotropic glutamate receptors in retinal neurons. Eur J Neurosci 2011; 35:56-65. [PMID: 22128843 DOI: 10.1111/j.1460-9568.2011.07925.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
D-Serine is an important signaling molecule throughout the central nervous system, acting as an N-methyl-D-aspartate (NMDA) receptor coagonist. This study investigated the D-serine modulation of non-NMDA ionotropic glutamate receptors expressed by inner retinal neurons. We first identified that the degradation of endogenous retinal D-serine, by application of D-amino acid oxidase, caused an enhancement of kainate- and α-amino-3-hydroxy-5-methyl-4-isoxazoleproprionic acid (AMPA) receptor-mediated calcium responses from the ganglion cell layer of the isolated rat retina and light-evoked responses obtained by multi-electrode array recordings from the guinea pig retina. Approximately 30-45% of cells were endogenously inhibited by D-serine, as suggested by the effect of D-amino acid oxidase. Conversely, bath application of D-serine caused a reduction in multi-electrode array recorded responses and decreased kainate, but not potassium-induced calcium responses, in a concentration-dependent manner (IC(50), 280 μm). Using cultured retinal ganglion cells to reduce network influences, D-serine reduced kainate-induced calcium responses and AMPA induced whole-cell currents. Finally, the inhibitory effect of D-serine on the kainate-induced calcium response was abolished by IEM 1460, thereby identifying calcium-permeable AMPA receptors as a potential target for D-serine. To our knowledge, this is the first study to address specifically the effect of D-serine on AMPA/kainate receptors in intact central nervous system tissue, to identify its effect on calcium permeable AMPA receptors and to report the endogenous inhibition of AMPA/kainate receptors.
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Affiliation(s)
- Bryan A Daniels
- Department of Anatomy and Neurobiology, Dalhousie University, Sir Charles Tupper Building, 5850 College Street, Halifax, NS, Canada B3H 4R2
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Nishikawa T. Analysis of free d-serine in mammals and its biological relevance. J Chromatogr B Analyt Technol Biomed Life Sci 2011; 879:3169-83. [DOI: 10.1016/j.jchromb.2011.08.030] [Citation(s) in RCA: 109] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2011] [Revised: 08/16/2011] [Accepted: 08/24/2011] [Indexed: 11/29/2022]
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