1
|
Supplisson S. Dynamic role of GlyT1 as glycine sink or source: Pharmacological implications for the gain control of NMDA receptors. Neuroscience 2024:S0306-4522(24)00350-6. [PMID: 39059742 DOI: 10.1016/j.neuroscience.2024.07.037] [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: 02/27/2024] [Revised: 07/03/2024] [Accepted: 07/22/2024] [Indexed: 07/28/2024]
Abstract
Glycine transporter 1 (GlyT1) mediates the termination of inhibitory glycinergic receptor signaling in the spinal cord and brainstem, and is also present diffusely in the forebrain. Here, it regulates the ambient glycine concentration and influences the 'glycine' site occupancy of N-methyl-d-aspartate receptors (NMDARs). GlyT1 is a reversible transporter with a substantial, but not excessive, sodium-motive force for uphill transport. This study investigates its role as a potential source of glycine supply, either by reverse uptake or heteroexchange. Indeed, glutamate alone does not induce NMDAR current in "naive" oocytes co-expressing GluN1/GluN2A and GlyT1, a previously characterized cellular model . However, after substantial intracellular glycine accumulation, GlyT1 reverses its transport mode, and begins to release glycine into the external compartment, allowing NMDAR activation by glutamate alone. These uptake-dependent glutamate currents were blocked by ALX-5407 and potentiated by sarcosine, a specific inhibitor and substrate of GlyT1, respectively, suggesting a higher occupancy of the co-agonist site when GlyT1 functions as a glycine source either by reversed-uptake or by heteroexchange. These two glycine release mechanisms can be distinguished by their voltage dependence, as the reversed-uptake cycle dcreases at hyperpolarized potentials, whereas heteroexchange electroneutrality preserves glycine efflux and NMDAR activation at these potentials. These results establish GlyT1-mediated efflux as a positive regulator of NMDAR coagonist site occupancy, and demonstrate the efficacy of sarcosine heteroexchange in enhancing coagonist site occupancy. Because NMDAR facilitation by GlyT1-inhibitors and sarcosine relies on different transport mechanisms, their actions may be a source of variability in reversing NMDAR hypofunction in schizophrenia.
Collapse
Affiliation(s)
- Stéphane Supplisson
- Institut de Biologie de l'ENS (IBENS), Ecole normale supérieure, Université PSL, CNRS, INSERM, Paris, F-75005, France.
| |
Collapse
|
2
|
Fornaro M, Caiazza C, Billeci M, Berk M, Marx W, Balanzá-Martinez V, De Prisco M, Pezone R, De Simone G, Solini N, Iasevoli F, Berna F, Fond G, Boyer L, Carvalho AF, Dragioti E, Fiedorowicz JG, de Bartolomeis A, Correll CU, Solmi M. Nutraceuticals and phytoceuticals in the treatment of schizophrenia: a systematic review and network meta-analysis "Nutra NMA SCZ". Mol Psychiatry 2024:10.1038/s41380-024-02645-y. [PMID: 39026098 DOI: 10.1038/s41380-024-02645-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Revised: 06/18/2024] [Accepted: 06/21/2024] [Indexed: 07/20/2024]
Abstract
Sub-optimal response in schizophrenia is frequent, warranting augmentation strategies over treatment-as-usual (TAU). We assessed nutraceuticals/phytoceutical augmentation strategies via network meta-analysis. Randomized controlled trials in schizophrenia/schizoaffective disorder were identified via the following databases: PubMed, MEDLINE, EMBASE, Scopus, PsycINFO, CENTRAL, and ClinicalTrials.gov. Change (Standardized Mean Difference = SMD) in total symptomatology and acceptability (Risk Ratio = RR) were co-primary outcomes. Secondary outcomes were positive, negative, cognitive, and depressive symptom changes, general psychopathology, tolerability, and response rates. We conducted subset analyses by disease phase and sensitivity analyses by risk of bias and assessed global/local inconsistency, publication bias, risk of bias, and confidence in the evidence. The systematic review included 49 records documenting 50 studies (n = 2384) documenting 22 interventions. Citicoline (SMD =-1.05,95%CI = -1.85; -0.24), L-lysine (SMD = -1.04,95%CI = -1.84; -0.25), N-acetylcysteine (SMD = -0.87, 95%CI = -1.27; -0.47) and sarcosine (SMD = -0.5,95%CI = -0.87-0.13) outperformed placebo for total symptomatology. High heterogeneity (tau2 = 0.10, I2 = 55.9%) and global inconsistency (Q = 40.79, df = 18, p = 0.002) emerged without publication bias (Egger's test, p = 0.42). Sarcosine improved negative symptoms (SMD = -0.65, 95%CI = -1.10; -0.19). N-acetylcysteine improved negative symptoms (SMD = -0.90, 95%CI = -1.42; -0.39)/general psychopathology (SMD = -0.76, 95%CI = -1.39; -0.13). No compound improved total symptomatology within acute phase studies (k = 7, n = 422). Sarcosine (SMD = -1.26,95%CI = -1.91; -0.60), citicoline (SMD = -1.05,95%CI = -1.65;-0.44), and N-acetylcysteine (SMD = -0.55,95%CI = -0.92,-0.19) outperformed placebo augmentation in clinically stable participants. Sensitivity analyses removing high-risk-of-bias studies confirmed overall findings in all phases and clinically stable samples. In contrast, the acute phase analysis restricted to low risk-of-bias studies showed a superior effect vs. placebo for N-acetylcysteine (SMD = -1.10, 95%CI = -1.75,-0.45), L-lysine (SMD = -1.05,95%CI = -1.55, -0.19), omega-3 fatty acids (SMD = -0.83,95%CI = -1.31, -0.34) and withania somnifera (SMD = -0.71,95%CI = -1.21,-0.22). Citicoline (SMD = -1.05,95%CI = -1.86,-0.23), L-lysine (SMD = -1.04,95%CI = -1.84,-0.24), N-acetylcysteine (SMD = -0.89,95%CI = -1.35,-0.43) and sarcosine (SMD = -0.61,95%CI = -1.02,-0.21) outperformed placebo augmentation of TAU ("any phase"). Drop-out due to any cause or adverse events did not differ between nutraceutical/phytoceutical vs. placebo+TAU. Sarcosine, citicoline, and N-acetylcysteine are promising augmentation interventions in stable patients with schizophrenia, yet the quality of evidence is low to very low. Further high-quality trials in acute phases/specific outcomes/difficult-to-treat schizophrenia are warranted.
Collapse
Affiliation(s)
- Michele Fornaro
- Department of Neuroscience, Reproductive Sciences, and Dentistry, Section of Psychiatry, University School of Medicine Federico II, Naples, Italy.
| | - Claudio Caiazza
- Department of Neuroscience, Reproductive Sciences, and Dentistry, Section of Psychiatry, University School of Medicine Federico II, Naples, Italy
| | - Martina Billeci
- Department of Neuroscience, Reproductive Sciences, and Dentistry, Section of Psychiatry, University School of Medicine Federico II, Naples, Italy
| | - Michael Berk
- Deakin University, IMPACT, the Institute for Mental and Physical Health and Clinical Translation Strategic Research Centre, School of Medicine, Geelong, VIC, Australia
- Mental Health Drug and Alcohol Services, Barwon Health, Geelong, VIC, Australia
- Orygen, The National Centre of Excellence in Youth Mental Health, Melbourne, VIC, Australia
- Centre for Youth Mental Health, Florey Institute for Neuroscience and Mental Health, Melbourne, VIC, Australia
- Department of Psychiatry, The University of Melbourne, Melbourne, VIC, Australia
| | - Wolfgang Marx
- Food & Mood Centre, Deakin University, IMPACT (the Institute for Mental and Physical Health and Clinical Translation), Geelong, VIC, Australia
| | - Vicent Balanzá-Martinez
- Teaching Unit of Psychiatry and Psychological Medicine, Department of Medicine, Centro de Investigación Biomédica En Red de Salud Mental (CIBERSAM), University of Valencia, Valencia, Spain
| | - Michele De Prisco
- Bipolar and Depressive Disorders Unit, Institute of Neuroscience, Hospital Clinic, CIBERSAM, University of Barcelona, IDIBAPS, Barcelona, Catalonia, Spain
| | - Rosanna Pezone
- Department of Neuroscience, Reproductive Sciences, and Dentistry, Section of Psychiatry, University School of Medicine Federico II, Naples, Italy
| | - Giuseppe De Simone
- Department of Neuroscience, Reproductive Sciences, and Dentistry, Section of Psychiatry, University School of Medicine Federico II, Naples, Italy
| | - Niccolò Solini
- Department of Neuroscience, Reproductive Sciences, and Dentistry, Section of Psychiatry, University School of Medicine Federico II, Naples, Italy
| | - Felice Iasevoli
- Department of Neuroscience, Reproductive Sciences, and Dentistry, Section of Psychiatry, University School of Medicine Federico II, Naples, Italy
- Section of Psychiatry, Laboratory of Translational and Molecular Psychiatry and Unit of Treatment-Resistant Psychosis, Department of Neuroscience, Reproductive Sciences and Odontostomatology, University Medical School of Naples "Federico II", Naples, Italy
| | - Fabrice Berna
- Department of Psychiatry, Strasbourg University Hospital, University of Strasbourg, Strasbourg, France
| | - Guillaume Fond
- CEReSS-Health Service Research and Quality of Life Center, UR3279, Assistance Publique des Hôpitaux de Marseille, Aix-Marseille University, Marseille, France
- Fondation FondaMental Fondation de Coopération Scientifique en Santé Mentale, Université Paris Est, Créteil, France
| | - Laurent Boyer
- CEReSS-Health Service Research and Quality of Life Center, UR3279, Assistance Publique des Hôpitaux de Marseille, Aix-Marseille University, Marseille, France
- Fondation FondaMental Fondation de Coopération Scientifique en Santé Mentale, Université Paris Est, Créteil, France
| | - Andre Fèrrer Carvalho
- Innovation in Mental and Physical Health and Clinical Treatment (IMPACT) Strategic Research Centre, School of Medicine, Barwon Health, Deakin University, Geelong, VIC, Australia
| | - Elena Dragioti
- Pain and Rehabilitation Center, Department of Medicine and Health Sciences, Linköping University, Linköping, Sweden
| | - Jess G Fiedorowicz
- Department of Psychiatry, University of Ottawa, Ottawa, ON, Canada
- Department of Mental Health, The Ottawa Hospital, Ottawa, ON, Canada
- Ottawa Hospital Research Institute, University of Ottawa, Ottawa, ON, Canada
| | - Andrea de Bartolomeis
- Department of Neuroscience, Reproductive Sciences, and Dentistry, Section of Psychiatry, University School of Medicine Federico II, Naples, Italy
- Section of Psychiatry, Laboratory of Translational and Molecular Psychiatry and Unit of Treatment-Resistant Psychosis, Department of Neuroscience, Reproductive Sciences and Odontostomatology, University Medical School of Naples "Federico II", Naples, Italy
| | - Christoph U Correll
- Department of Psychiatry, Zucker Hillside Hospital, Northwell Health, Glen Oaks, NY, USA
- Department of Psychiatry and Molecular Medicine, Zucker School of Medicine at Hofstra/Northwell, Hempstead, NY, USA
- Center for Psychiatric Neuroscience, Feinstein Institute for Medical Research, Manhasset, NY, USA
- Department of Child and Adolescent Psychiatry, Charité Universitätsmedizin, Berlin, Germany
| | - Marco Solmi
- Department of Psychiatry, University of Ottawa, Ottawa, ON, Canada
- Department of Mental Health, The Ottawa Hospital, Ottawa, ON, Canada
- Ottawa Hospital Research Institute, University of Ottawa, Ottawa, ON, Canada
- Department of Child and Adolescent Psychiatry, Charité Universitätsmedizin, Berlin, Germany
| |
Collapse
|
3
|
Singer P, Yee BK. Inhibition of astrocytic glycine transporter-1: friend or foe for ameliorating NMDA receptor hypofunction? Front Cell Neurosci 2024; 18:1389718. [PMID: 38854433 PMCID: PMC11158624 DOI: 10.3389/fncel.2024.1389718] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2024] [Accepted: 05/09/2024] [Indexed: 06/11/2024] Open
Affiliation(s)
- Philipp Singer
- Roche Diagnostics International AG, Rotkreuz, Switzerland
| | - Benjamin K. Yee
- Department of Rehabilitation Sciences, The Hong Kong Polytechnic University, Kowloon, Hong Kong SAR, China
- Mental Health Research Centre, The Hong Kong Polytechnic University, Kowloon, Hong Kong SAR, China
| |
Collapse
|
4
|
Fornaro M, Caiazza C, Billeci M, Berk M, Marx W, Balanzá-Martínez V, De Prisco M, Pezone R, De Simone G, Solini N, Iasevoli F, Berna F, Fond G, Boyer L, Carvalho AF, Dragioti E, Fiedorowicz J, de Bartolomeis A, Correll C, Solmi M. Nutraceuticals and phytoceuticals in the treatment of schizophrenia: a systematic review and network meta-analysis. RESEARCH SQUARE 2024:rs.3.rs-3787917. [PMID: 38260297 PMCID: PMC10802721 DOI: 10.21203/rs.3.rs-3787917/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
Background Sub-optimal response in schizophrenia is frequent, warranting augmentation strategies over treatment-as-usual (TAU). Methods We assessed nutraceuticals/phytoceutical augmentation strategies via network meta-analysis. Randomized controlled trials in schizophrenia/schizoaffective disorder were identified via the following databases: PubMed, MEDLINE, EMBASE, Scopus, PsycINFO, CENTRAL, and ClinicalTrials.gov. Change (Standardized Mean Difference=SMD) in total symptomatology and acceptability (Risk Ratio=RR) were co-primary outcomes. Secondary outcomes were positive, negative, cognitive, and depressive symptom changes, general psychopathology, tolerability, and response rates. We conducted subset analyses by disease phase and sensitivity analyses by risk of bias and assessed global/local inconsistency, publication bias, risk of bias, and confidence in the evidence. Results The systematic review included 49 records documenting 50 studies (n=2,384) documenting 22 interventions. Citicoline (SMD=-1.05,95%CI=-1.85; -.24), L-lysine (SMD=-1.04,95%CI=-1.84;-.25), N-acetylcysteine (SMD=-.87,95%CI=-1.27;-.47) and sarcosine (SMD=-.5,95%CI=-.87-.13) outperformed placebo for total symptomatology. High heterogeneity (tau2=.10, I2=55.9%) and global inconsistency (Q=40.79, df=18, p=.002) emerged without publication bias (Egger's test, p=.42). Sarcosine improved negative symptoms (SMD=-.65, 95%CI=-1.10; -.19). N-acetylcysteine improved negative symptoms (SMD=-.90, 95%CI=-1.42; -.39)/general psychopathology (SMD=-.76, 95%CI=-1.39; -.13). No compound improved total symptomatology within acute phase studies (k=7, n=422). Sarcosine (SMD=-1.26,95%CI=-1.91; -.60), citicoline (SMD=-1.05,95%CI=-1.65;-.44), and N-acetylcysteine (SMD=-.55,95%CI=-.92,-.19) outperformed placebo augmentation in clinically stable participants. Sensitivity analyses removing high-risk-of-bias studies confirmed overall findings in all phases and clinically stable samples. In contrast, the acute phase analysis restricted to low risk-of-bias studies showed a superior effect vs. placebo for N-acetylcysteine (SMD=-1.10,95%CI=-1.75,-.45), L-lysine (SMD=-1.05,95%CI=-1.55,-.19), omega-3 fatty acids (SMD=-.83,95%CI=-1.31,-.34) and withania somnifera (SMD=-.71,95%CI=-1.21,-.22). Citicoline (SMD=-1.05,95%CI=-1.86,-.23), L-lysine (SMD=-1.04,95%CI=-1.84,-.24), N-acetylcysteine (SMD=-.89,95%CI=-1.35,-.43) and sarcosine (SMD=-.61,95%CI=-1.02,-.21) outperformed placebo augmentation of TAU ("any phase"). Drop-out due to any cause or adverse events did not differ between nutraceutical/phytoceutical vs. placebo+TAU. Conclusions Sarcosine, citicoline, and N-acetylcysteine are promising augmentation interventions in stable patients with schizophrenia, yet the quality of evidence is low to very low. Further high-quality trials in acute phases/specific outcomes/difficult-to-treat schizophrenia are warranted.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | | | - Laurent Boyer
- Innovation in Mental and Physical Health and Clinical Treatment (IMPACT) Strategic Research Centre, School of Medicine, Barwon Health, Deakin University, Geelong, VIC, Australia
| | - Andre F Carvalho
- Innovation in Mental and Physical Health and Clinical Treatment (IMPACT) Strategic Research Centre, School of Medicine, Barwon Health, Deakin University, Geelong, VIC, Australia
| | - Elena Dragioti
- Donald and Barbara Zucker School of Medicine at Hofstra/Northwell
| | - Jess Fiedorowicz
- Donald and Barbara Zucker School of Medicine at Hofstra/Northwell
| | | | | | | |
Collapse
|
5
|
Surti TS, Ranganathan M, Johannesen JK, Gueorguieva R, Deaso E, Kenney JG, Krystal JH, D'Souza DC. Randomized controlled trial of the glycine transporter 1 inhibitor PF-03463275 to enhance cognitive training and neuroplasticity in schizophrenia. Schizophr Res 2023; 256:36-43. [PMID: 37141764 PMCID: PMC10257994 DOI: 10.1016/j.schres.2023.04.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2022] [Revised: 03/23/2023] [Accepted: 04/19/2023] [Indexed: 05/06/2023]
Abstract
N-methyl-d-aspartate glutamate receptor (NMDAR) hypofunction is implicated in the impaired neuroplasticity and cognitive impairments associated with schizophrenia (CIAS). We hypothesized that enhancing NMDAR function by inhibiting the glycine transporter-1 (GLYT1) would improve neuroplasticity and thereby augment benefits of non-pharmacological cognitive training (CT) strategies. This study examined whether co-administration of a GLYT1 inhibitor and computerized CT would have synergistic effects on CIAS. Stable outpatients with schizophrenia participated in this double-blind, placebo-controlled, within-subject, crossover augmentation study. Participants received placebo or GLYT1 inhibitor (PF-03463275) for two 5-week periods separated by 2 weeks of washout. PF-03463275 doses (40 or 60 mg twice daily) were selected to produce high GLYT1 occupancy. To limit pharmacodynamic variability, only cytochrome P450 2D6 extensive metabolizers were included. Medication adherence was confirmed daily. Participants received 4 weeks of CT in each treatment period. Cognitive performance (MATRICS Consensus Cognitive Battery) and psychotic symptoms (Positive and Negative Syndrome Scale) were assessed in each period. 71 participants were randomized. PF-03463275 in combination with CT was feasible, safe, and well-tolerated at the doses prescribed but did not produce greater improvement in CIAS compared to CT alone. PF-03463275 was not associated with improved CT learning parameters. Participation in CT was associated with improvement in MCCB scores.
Collapse
Affiliation(s)
- Toral S Surti
- Schizophrenia and Neuropharmacology Research Group, VA Connecticut Healthcare System, West Haven, CT, United States of America; Abraham Ribicoff Research Facilities, Connecticut Mental Health Center, New Haven, CT, United States of America; Department of Psychiatry, Yale University School of Medicine, New Haven, CT, United States of America.
| | - Mohini Ranganathan
- Schizophrenia and Neuropharmacology Research Group, VA Connecticut Healthcare System, West Haven, CT, United States of America; Abraham Ribicoff Research Facilities, Connecticut Mental Health Center, New Haven, CT, United States of America; Department of Psychiatry, Yale University School of Medicine, New Haven, CT, United States of America
| | - Jason K Johannesen
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, United States of America
| | - Ralitza Gueorguieva
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, United States of America
| | - Emma Deaso
- Schizophrenia and Neuropharmacology Research Group, VA Connecticut Healthcare System, West Haven, CT, United States of America; Abraham Ribicoff Research Facilities, Connecticut Mental Health Center, New Haven, CT, United States of America; Department of Psychiatry, Yale University School of Medicine, New Haven, CT, United States of America
| | - Joshua G Kenney
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, United States of America
| | - John H Krystal
- Schizophrenia and Neuropharmacology Research Group, VA Connecticut Healthcare System, West Haven, CT, United States of America; Abraham Ribicoff Research Facilities, Connecticut Mental Health Center, New Haven, CT, United States of America; Department of Psychiatry, Yale University School of Medicine, New Haven, CT, United States of America; Mental Health Service Line, Veterans Affairs Connecticut Healthcare System, West Haven, CT, United States of America
| | - Deepak Cyril D'Souza
- Schizophrenia and Neuropharmacology Research Group, VA Connecticut Healthcare System, West Haven, CT, United States of America; Abraham Ribicoff Research Facilities, Connecticut Mental Health Center, New Haven, CT, United States of America; Department of Psychiatry, Yale University School of Medicine, New Haven, CT, United States of America
| |
Collapse
|
6
|
Ju J, Liu L, Yang X, Men S, Hou ST. Distinctive effects of NMDA receptor modulators on cerebral microcirculation in a schizophrenia mouse model. Biochem Biophys Res Commun 2023; 653:62-68. [PMID: 36857901 DOI: 10.1016/j.bbrc.2023.02.040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Revised: 01/16/2023] [Accepted: 02/15/2023] [Indexed: 02/18/2023]
Abstract
Substantial evidence demonstrates that schizophrenia patients have altered cerebral microcirculation. However, little is known regarding how cerebral microcirculatory blood flow (microCBF) changes in schizophrenia. Here, using time-lapse two-photon imaging of individual capillaries, we demonstrated a substantial decrease in cerebral microcirculation in a mouse model of schizophrenia. The involvement of NMDA receptor (NMDAR) functions was investigated to understand further the mechanism of microcirculation reduction in this animal model. Administration of D-serine, a selective full agonist at the glycine site of NMDAR, significantly increased the microCBF in the schizophrenia mouse. Interestingly, administration of GNE-8324, a GluN2A-selective positive allosteric modulator that selectively enhances NMDAR-mediated synaptic responses in inhibitory but not excitatory neurons, had no effect on the microCBF of the schizophrenia mice. Together, these data indicated that NMDAR participated in the regulation of microcirculation in schizophrenia using a mechanism dependent on the tonic NMDAR signaling and the selective modulation of inhibitory neuron activity. Further studies are warranted to establish NMDAR's role in modulating microcirculation in schizophrenia.
Collapse
Affiliation(s)
- Jun Ju
- Brain Research Centre and Department of Biology, Southern University of Science and Technology, Shenzhen, China
| | - Luping Liu
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, NT, Hong Kong Special Administrative Region of China
| | - Xinyi Yang
- Brain Research Centre and Department of Biology, Southern University of Science and Technology, Shenzhen, China
| | - Siqi Men
- Brain Research Centre and Department of Biology, Southern University of Science and Technology, Shenzhen, China
| | - Sheng-Tao Hou
- Brain Research Centre and Department of Biology, Southern University of Science and Technology, Shenzhen, China.
| |
Collapse
|
7
|
Piniella D, Zafra F. Functional crosstalk of the glycine transporter GlyT1 and NMDA receptors. Neuropharmacology 2023; 232:109514. [PMID: 37003571 DOI: 10.1016/j.neuropharm.2023.109514] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 03/10/2023] [Accepted: 03/20/2023] [Indexed: 04/03/2023]
Abstract
NMDA-type glutamate receptors (NMDARs) constitute one of the main glutamate (Glu) targets in the central nervous system and are involved in synaptic plasticity, which is the molecular substrate of learning and memory. Hypofunction of NMDARs has been associated with schizophrenia, while overstimulation causes neuronal death in neurodegenerative diseases or in stroke. The function of NMDARs requires coincidental binding of Glu along with other cellular signals such as neuronal depolarization, and the presence of other endogenous ligands that modulate their activity by allosterism. Among these allosteric modulators are zinc, protons and Gly, which is an obligatory co-agonist. These characteristics differentiate NMDARs from other receptors, and their structural bases have begun to be established in recent years. In this review we focus on the crosstalk between Glu and glycine (Gly), whose concentration in the NMDAR microenvironment is maintained by various Gly transporters that remove or release it into the medium in a regulated manner. The GlyT1 transporter is particularly involved in this task, and has become a target of great interest for the treatment of schizophrenia since its inhibition leads to an increase in synaptic Gly levels that enhances the activity of NMDARs. However, the only drug that has completed phase III clinical trials did not yield the expected results. Notwithstanding, there are additional drugs that continue to be investigated, and it is hoped that knowledge gained from the recently published 3D structure of GlyT1 may allow the rational design of more effective new drugs.
Collapse
Affiliation(s)
- Dolores Piniella
- Centro de Biología Molecular Severo Ochoa, Facultad de Ciencias, Consejo Superior de Investigaciones Científicas, Universidad Autónoma de Madrid, Madrid, Spain; IdiPAZ, Institute of Health Carlos III (ISCIII), Spain
| | - Francisco Zafra
- Centro de Biología Molecular Severo Ochoa, Facultad de Ciencias, Consejo Superior de Investigaciones Científicas, Universidad Autónoma de Madrid, Madrid, Spain; IdiPAZ, Institute of Health Carlos III (ISCIII), Spain.
| |
Collapse
|
8
|
Chakraborty P, Dey A, Gopalakrishnan AV, Swati K, Ojha S, Prakash A, Kumar D, Ambasta RK, Jha NK, Jha SK, Dewanjee S. Glutamatergic neurotransmission: A potential pharmacotherapeutic target for the treatment of cognitive disorders. Ageing Res Rev 2023; 85:101838. [PMID: 36610558 DOI: 10.1016/j.arr.2022.101838] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2022] [Revised: 12/27/2022] [Accepted: 12/29/2022] [Indexed: 01/06/2023]
Abstract
In the mammalian brain, glutamate is regarded to be the primary excitatory neurotransmitter due to its widespread distribution and wide range of metabolic functions. Glutamate plays key roles in regulating neurogenesis, synaptogenesis, neurite outgrowth, and neuron survival in the brain. Ionotropic and metabotropic glutamate receptors, neurotransmitters, neurotensin, neurosteroids, and others co-ordinately formulate a complex glutamatergic network in the brain that maintains optimal excitatory neurotransmission. Cognitive activities are potentially synchronized by the glutamatergic activities in the brain via restoring synaptic plasticity. Dysfunctional glutamate receptors and other glutamatergic components are responsible for the aberrant glutamatergic activity in the brain that cause cognitive impairments, loss of synaptic plasticity, and neuronal damage. Thus, controlling the brain's glutamatergic transmission and modifying glutamate receptor function could be a potential therapeutic strategy for cognitive disorders. Certain drugs that regulate glutamate receptor activities have shown therapeutic promise in improving cognitive functions in preclinical and clinical studies. However, several issues regarding precise functional information of glutamatergic activity are yet to be comprehensively understood. The present article discusses the scope of developing glutamatergic systems as prospective pharmacotherapeutic targets to treat cognitive disorders. Special attention has been given to recent developments, challenges, and future prospects.
Collapse
Affiliation(s)
- Pratik Chakraborty
- Advanced Pharmacognosy Research Laboratory, Department of Pharmaceutical Technology, Jadavpur University, Kolkata 700032, India
| | - Abhijit Dey
- Department of Life Sciences, Presidency University, Kolkata 700073, West Bengal, India
| | - Abilash Valsala Gopalakrishnan
- Department of Biomedical Sciences, School of Bio Sciences and Technology, Vellore Institute of Technology (VIT), Vellore, Tamil Nadu 632014, India
| | - Kumari Swati
- Department of Biotechnology, School of Life Science, Mahatma Gandhi Central University, Motihari, Bihar, India
| | - Shreesh Ojha
- Department of Pharmacology and Therapeutics, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, Abu Dhabi, United Arab Emirates
| | - Anand Prakash
- Department of Biotechnology, School of Life Science, Mahatma Gandhi Central University, Motihari, Bihar, India
| | - Dhruv Kumar
- School of Health Sciences & Technology, UPES University, Dehradun, Uttarakhand 248007, India
| | - Rashmi K Ambasta
- Molecular Neuroscience and Functional Genomics Laboratory, Department of Biotechnology, Delhi Technological University (Formerly DCE), Delhi 110042, India
| | - Niraj Kumar Jha
- Department of Biotechnology, School of Engineering and Technology, Sharda University, Greater Noida 201310, UP, India; School of Bioengineering & Biosciences, Lovely Professional University, Phagwara, Punjab 144411, India.
| | - Saurabh Kumar Jha
- Department of Biotechnology, School of Engineering and Technology, Sharda University, Greater Noida 201310, UP, India; Department of Biotechnology Engineering and Food Technology, Chandigarh University, Mohali 140413, India; Department of Biotechnology, School of Applied & Life Sciences (SALS), Uttaranchal University, Dehradun 248007, India.
| | - Saikat Dewanjee
- Advanced Pharmacognosy Research Laboratory, Department of Pharmaceutical Technology, Jadavpur University, Kolkata 700032, India.
| |
Collapse
|
9
|
Ketamine, benzoate, and sarcosine for treating depression. Neuropharmacology 2023; 223:109351. [PMID: 36423705 DOI: 10.1016/j.neuropharm.2022.109351] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Revised: 11/18/2022] [Accepted: 11/20/2022] [Indexed: 11/23/2022]
Abstract
Studies have demonstrated the beneficial therapeutic effects of sarcosine, benzoate, and ketamine (including esketamine and arketamine) on depression. These drugs mainly act by modulating N-methyl-d-aspartate glutamate receptors (NMDARs) and reducing inflammation in the brain. Although ketamine, benzoate, and sarcosine act differently as the antagonists or coagonists of NMDARs, they all have demonstrated efficacy in animal models or human trials. In vitro and in vivo studies have indicated that sarcosine, benzoate, and ketamine exert their anti-inflammatory effects by inhibiting microglial activity. This review summarizes and compares the efficacy of the possible therapeutic mechanisms of sarcosine, benzoate, ketamine, esketamine, and arketamine. These compounds act as both NMDAR modulators and anti-inflammatory drugs and thus can be effective in the treatment of depression.
Collapse
|
10
|
Glutamatergic dysfunction in Schizophrenia. Transl Psychiatry 2022; 12:500. [PMID: 36463316 PMCID: PMC9719533 DOI: 10.1038/s41398-022-02253-w] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Revised: 11/05/2022] [Accepted: 11/09/2022] [Indexed: 12/04/2022] Open
Abstract
The NMDA-R hypofunction model of schizophrenia started with the clinical observation of the precipitation of psychotic symptoms in patients with schizophrenia exposed to PCP or ketamine. Healthy volunteers exposed to acute low doses of ketamine experienced mild psychosis but also negative and cognitive type symptoms reminiscent of the full clinical picture of schizophrenia. In rodents, acute systemic ketamine resulted in a paradoxical increase in extracellular frontal glutamate as well as of dopamine. Similar increase in prefrontal glutamate was documented with acute ketamine in healthy volunteers with 1H-MRS. Furthermore, sub-chronic low dose PCP lead to reductions in frontal dendritic tree density in rodents. In post-mortem ultrastructural studies in schizophrenia, a broad reduction in dendritic complexity and somal volume of pyramidal cells has been repeatedly described. This most likely accounts for the broad, subtle progressive cortical thinning described with MRI in- vivo. Additionally, prefrontal reductions in the obligatory GluN1 subunit of the NMDA-R has been repeatedly found in post-mortem tissue. The vast 1H-MRS literature in schizophrenia has documented trait-like small increases in glutamate concentrations in striatum very early in the illness, before antipsychotic treatment (the same structure where increased pre-synaptic release of dopamine has been reported with PET). The more recent genetic literature has reliably detected very small risk effects for common variants involving several glutamate-related genes. The pharmacological literature has followed two main tracks, directly informed by the NMDA-R hypo model: agonism at the glycine site (as mostly add-on studies targeting negative and cognitive symptoms); and pre-synaptic modulation of glutamatergic release (as single agents for acute psychosis). Unfortunately, both approaches have failed so far. There is little doubt that brain glutamatergic abnormalities are present in schizophrenia and that some of these are related to the etiology of the illness. The genetic literature directly supports a non- specific etiological role for glutamatergic dysfunction. Whether NMDA-R hypofunction as a specific mechanism accounts for any important component of the illness is still not evident. However, a glutamatergic model still has heuristic value to guide future research in schizophrenia. New tools to jointly examine brain glutamatergic, GABA-ergic and dopaminergic systems in-vivo, early in the illness, may lay the ground for a next generation of clinical trials that go beyond dopamine D2 blockade.
Collapse
|
11
|
Deiana S, Hauber W, Munster A, Sommer S, Ferger B, Marti A, Schmid B, Dorner-Ciossek C, Rosenbrock H. Pro-cognitive effects of the GlyT1 inhibitor Bitopertin in rodents. Eur J Pharmacol 2022; 935:175306. [DOI: 10.1016/j.ejphar.2022.175306] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Revised: 09/26/2022] [Accepted: 09/26/2022] [Indexed: 12/01/2022]
|
12
|
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.
Collapse
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.)
| |
Collapse
|
13
|
Rosenbrock H, Dorner-Ciossek C, Giovannini R, Schmid B, Schuelert N. Effects of the glycine transporter-1 inhibitor iclepertin (BI 425809) on sensory processing, neural network function, and cognition in animal models related to schizophrenia. J Pharmacol Exp Ther 2022; 382:223-232. [PMID: 35661632 DOI: 10.1124/jpet.121.001071] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Accepted: 05/04/2022] [Indexed: 11/22/2022] Open
Abstract
N-methyl-D-aspartate (NMDA) receptor hypofunction leading to neural network dysfunction is thought to play an important role in the pathophysiology of cognitive impairment associated with schizophrenia (CIAS). Increasing extracellular concentrations of the NMDA receptor co-agonist glycine through inhibition of glycine transporter-1 (GlyT1) has the potential to treat CIAS by improving cortical network function through enhanced glutamatergic signaling. Indeed, the novel GlyT1 inhibitor iclepertin (BI 425809) improved cognition in a recent clinical study in patients with schizophrenia. The present study tested the ability of iclepertin to reverse MK-801-induced deficits in auditory sensory processing and cortical network function using electroencephalography (EEG) to measure auditory event-related potentials (AERP) and 40 Hz auditory steady-state response (ASSR). In addition, improvements in memory performance with iclepertin were evaluated using the T-maze spontaneous alternation test in MK-801-treated mice and the social recognition test in naïve rats. Iclepertin reversed MK-801-induced deficits in the AERP readouts N1 amplitude and N1 gating, as well as 40 Hz ASSR power and inter-trial coherence. Additionally, iclepertin significantly attenuated an MK-801-induced increase in basal gamma power. Furthermore, iclepertin reversed MK-801-induced working memory deficits in mice and improved social recognition memory performance in rats. Overall, this study demonstrates that inhibition of GlyT1 is sufficient to attenuate MK-801-induced deficits in translatable EEG parameters relevant to schizophrenia. Moreover, iclepertin showed memory-enhancing effects in rodent cognition tasks, further demonstrating the potential for GlyT1 inhibition to treat CIAS. Significance Statement Despite the significant patient burden caused by cognitive impairment associated with schizophrenia, there are currently no approved pharmacotherapies. In this preclinical study, the novel glycine transporter inhibitor iclepertin (BI 425809) reversed sensory processing deficits and neural network dysfunction evoked by inhibition of N-methyl-D-aspartate (NMDA) receptors, and enhanced working memory performance and social recognition in rodents. These findings support previous clinical evidence for the pro-cognitive effects of iclepertin.
Collapse
Affiliation(s)
- Holger Rosenbrock
- CNS Discovery Research, Boehringer Ingelheim Pharma GmbH & Co. KG, Germany
| | | | | | - Bernhard Schmid
- Drug Discovery Sciences, Boehringer Ingelheim Pharma GmbH & Co. KG, Germany
| | - Niklas Schuelert
- CNS Discovery Research, Boehringer Ingelheim Pharma GmbH & Co. KG, Germany
| |
Collapse
|
14
|
Kim J, Roh JD, Kim S, Kang H, Bae M, Kim E. Slc6a20a Heterozygous and Homozygous Mutant Mice Display Differential Behavioral and Transcriptomic Changes. Front Mol Neurosci 2022; 15:857820. [PMID: 35321029 PMCID: PMC8936588 DOI: 10.3389/fnmol.2022.857820] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Accepted: 01/28/2022] [Indexed: 11/23/2022] Open
Abstract
SLC6A20A is a proline and glycine transporter known to regulate glycine homeostasis and NMDA receptor (NMDAR) function in the brain. A previous study found increases in ambient glycine levels and NMDA receptor-mediated synaptic transmission in the brains of Slc6a20a-haploinsufficient mice, but it remained unknown whether Slc6a20a deficiency leads to disease-related behavioral deficits in mice. Here, we report that Slc6a20a heterozygous and homozygous mutant mice display differential behavioral phenotypes in locomotor, repetitive behavioral, and spatial and fear memory domains. In addition, these mice show differential transcriptomic changes in synapse, ribosome, mitochondria, autism, epilepsy, and neuron-related genes. These results suggest that heterozygous and homozygous Slc6a20a deletions in mice lead to differential changes in behaviors and transcriptomes.
Collapse
Affiliation(s)
- Junhyung Kim
- Department of Biological Sciences, Korea Advanced Institute for Science and Technology (KAIST), Daejeon, South Korea
| | - Junyeop Daniel Roh
- Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS), Daejeon, South Korea
| | - Seongbin Kim
- Department of Biological Sciences, Korea Advanced Institute for Science and Technology (KAIST), Daejeon, South Korea
| | - Hyojin Kang
- Division of National Supercomputing, Korea Institute of Science and Technology Information (KISTI), Daejeon, South Korea
| | - Mihyun Bae
- Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS), Daejeon, South Korea
| | - Eunjoon Kim
- Department of Biological Sciences, Korea Advanced Institute for Science and Technology (KAIST), Daejeon, South Korea
- Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS), Daejeon, South Korea
- *Correspondence: Eunjoon Kim,
| |
Collapse
|
15
|
Seetharam JC, Maiti R, Mishra A, Mishra BR. Efficacy and safety of add-on sodium benzoate, a D-amino acid oxidase inhibitor, in treatment of schizophrenia: A systematic review and meta-analysis. Asian J Psychiatr 2022; 68:102947. [PMID: 34890931 DOI: 10.1016/j.ajp.2021.102947] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Revised: 10/22/2021] [Accepted: 11/26/2021] [Indexed: 02/04/2023]
Abstract
BACKGROUND The role of sodium benzoate, an NMDA receptor enhancer, in schizophrenia has been evaluated in a few clinical trials, but results are contradictory and inconclusive. The present meta-analysis has evaluated the efficacy and safety of add-on sodium benzoate for the treatment of schizophrenia. METHODS After performing a literature search on MEDLINE/PubMed, Scopus, Cochrane databases and International Clinical Trial Registry Platform, reviewers assessed eligibility and extracted data from four relevant articles. PRISMA guidelines were followed in the selection, analysis, and reporting of findings. The random-effect model was used to estimate effect size. Quality assessment was done using the risk of bias assessment tool, and sensitivity analysis was done in case of high heterogeneity. RESULTS Add-on sodium benzoate can improve positive symptoms of schizophrenia significantly (MD: -1.87; 95%CI: -3.25 to -0.48; p = 0.008) but had no significant favourable effect on negative symptoms (p = 0.84), general psychopathology (p = 0.49), and total PANSS score (p = 0.19) over the control. There was no significant improvement in GAF (p = 0.43), CGI (p = 0.58), cognitive function (p = 0.46) and quality of life (p = 0.73). Extrapyramidal symptoms were significantly higher (MD: 0.39; 95% CI:0.19-0.60; p = 0.0002) in the sodium benzoate group in comparison to the control group; however, there was no significant difference in respect to other adverse events. CONCLUSION Sodium benzoate can improve the positive symptoms of schizophrenia without any beneficial effect on other symptomatology, cognition, quality of life and functioning. Further studies are needed to evaluate long-term efficacy, safety and use in specific subgroups of patients.
Collapse
Affiliation(s)
| | - Rituparna Maiti
- Department of Pharmacology All India Institute of Medical Sciences (AIIMS), Bhubaneswar, India.
| | - Archana Mishra
- Department of Pharmacology All India Institute of Medical Sciences (AIIMS), New Delhi, India.
| | - Biswa Ranjan Mishra
- Department of Psychiatry All India Institute of Medical Sciences (AIIMS), Bhubaneswar, India.
| |
Collapse
|
16
|
Veselinović T, Neuner I. Progress and Pitfalls in Developing Agents to Treat Neurocognitive Deficits Associated with Schizophrenia. CNS Drugs 2022; 36:819-858. [PMID: 35831706 PMCID: PMC9345797 DOI: 10.1007/s40263-022-00935-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 06/06/2022] [Indexed: 12/11/2022]
Abstract
Cognitive impairments associated with schizophrenia (CIAS) represent a central element of the symptomatology of this severe mental disorder. CIAS substantially determine the disease prognosis and hardly, if at all, respond to treatment with currently available antipsychotics. Remarkably, all drugs presently approved for the treatment of schizophrenia are, to varying degrees, dopamine D2/D3 receptor blockers. In turn, rapidly growing evidence suggests the immense significance of systems other than the dopaminergic system in the genesis of CIAS. Accordingly, current efforts addressing the unmet needs of patients with schizophrenia are primarily based on interventions in other non-dopaminergic systems. In this review article, we provide a brief overview of the available evidence on the importance of specific systems in the development of CIAS. In addition, we describe the promising targets for the development of new drugs that have been used so far. In doing so, we present the most important candidates that have been investigated in the field of the specific systems in recent years and present a summary of the results available at the time of drafting this review (May 2022), as well as the currently ongoing studies.
Collapse
Affiliation(s)
- Tanja Veselinović
- Department of Psychiatry, Psychotherapy and Psychosomatics, RWTH Aachen University, Pauwelsstrasse 30, 52074, Aachen, Germany.
- Institute of Neuroscience and Medicine 4, INM-4, Forschungszentrum Jülich, Jülich, Germany.
| | - Irene Neuner
- Department of Psychiatry, Psychotherapy and Psychosomatics, RWTH Aachen University, Pauwelsstrasse 30, 52074, Aachen, Germany
- Institute of Neuroscience and Medicine 4, INM-4, Forschungszentrum Jülich, Jülich, Germany
- JARA-BRAIN, Aachen, Germany
| |
Collapse
|
17
|
Hoffmann C, Evcüman S, Neumaier F, Zlatopolskiy BD, Humpert S, Bier D, Holschbach M, Schulze A, Endepols H, Neumaier B. [ 18F]ALX5406: A Brain-Penetrating Prodrug for GlyT1-Specific PET Imaging. ACS Chem Neurosci 2021; 12:3335-3346. [PMID: 34449193 DOI: 10.1021/acschemneuro.1c00284] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Selective inhibition of glycine transporter 1 (GlyT1) has emerged as a potential approach to alleviate N-methyl-d-aspartate receptor (NMDAR) hypofunction in patients with schizophrenia and cognitive decline. ALX5407 is a potent and selective inhibitor of GlyT1 derived from the metabolic intermediate sarcosine (N-methylglycine) that showed antipsychotic potential in a number of animal models. Whereas clinical application of ALX5407 is limited by adverse effects on motor performance and respiratory function, a suitably radiolabeled drug could represent a promising PET tracer for the visualization of GlyT1 in the brain. Herein, [18F]ALX5407 and the corresponding methyl ester, [18F]ALX5406, were prepared by alcohol-enhanced copper mediated radiofluorination and studied in vitro in rat brain slices and in vivo in normal rats. [18F]ALX5407 demonstrated accumulation consistent with the distribution of GlyT1 in in vitro autoradiographic studies but no brain uptake in μPET experiments in naı̈ve rats. In contrast, the methyl ester [18F]ALX5406 rapidly entered the brain and was enzymatically transformed into [18F]ALX5407, resulting in a regional accumulation pattern consistent with GlyT1 specific binding. We conclude that [18F]ALX5406 is a promising and easily accessible PET probe for preclinical in vivo imaging of GlyT1 in the brain.
Collapse
Affiliation(s)
- Chris Hoffmann
- Nuclear Chemistry (INM-5), Institute of Neuroscience and Medicine, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
- Institute of Radiochemistry and Experimental Molecular Imaging, University of Cologne, Faculty of Medicine, and University Hospital Cologne, 50937 Cologne, Germany
| | - Sibel Evcüman
- Nuclear Chemistry (INM-5), Institute of Neuroscience and Medicine, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - Felix Neumaier
- Nuclear Chemistry (INM-5), Institute of Neuroscience and Medicine, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
- Institute of Radiochemistry and Experimental Molecular Imaging, University of Cologne, Faculty of Medicine, and University Hospital Cologne, 50937 Cologne, Germany
| | - Boris D. Zlatopolskiy
- Nuclear Chemistry (INM-5), Institute of Neuroscience and Medicine, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
- Institute of Radiochemistry and Experimental Molecular Imaging, University of Cologne, Faculty of Medicine, and University Hospital Cologne, 50937 Cologne, Germany
| | - Swen Humpert
- Nuclear Chemistry (INM-5), Institute of Neuroscience and Medicine, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - Dirk Bier
- Nuclear Chemistry (INM-5), Institute of Neuroscience and Medicine, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - Marcus Holschbach
- Nuclear Chemistry (INM-5), Institute of Neuroscience and Medicine, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - Annette Schulze
- Nuclear Chemistry (INM-5), Institute of Neuroscience and Medicine, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - Heike Endepols
- Nuclear Chemistry (INM-5), Institute of Neuroscience and Medicine, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
- Institute of Radiochemistry and Experimental Molecular Imaging, University of Cologne, Faculty of Medicine, and University Hospital Cologne, 50937 Cologne, Germany
- Nuclear Medicine Department, University of Cologne, Faculty of Medicine, and University Hospital Cologne, 50937 Cologne, Germany
| | - Bernd Neumaier
- Nuclear Chemistry (INM-5), Institute of Neuroscience and Medicine, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
- Institute of Radiochemistry and Experimental Molecular Imaging, University of Cologne, Faculty of Medicine, and University Hospital Cologne, 50937 Cologne, Germany
- Max Planck Institute of Metabolism Research, 50931 Cologne, Germany
| |
Collapse
|
18
|
Goh KK, Wu TH, Chen CH, Lu ML. Efficacy of N-methyl- D-aspartate receptor modulator augmentation in schizophrenia: A meta-analysis of randomised, placebo-controlled trials. J Psychopharmacol 2021; 35:236-252. [PMID: 33406959 DOI: 10.1177/0269881120965937] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
BACKGROUND Dysfunction of the N-methyl-D-aspartate glutamate receptor is involved in the putative pathology of schizophrenia. There is growing interest in the potential of N-methyl-D-aspartate receptor modulators to improve the symptoms of schizophrenia, but the evidence for the use of glutamatergic agents for augmenting schizophrenia remains inconclusive. AIMS We conducted a meta-analysis to test the efficacy and safety of N-methyl-D-aspartate receptor modulator supplements in patients with schizophrenia. METHODS Following a systemic search in MEDLINE, Embase, Cochrane and Scopus, 40 double-blinded, randomised, placebo-controlled trials involving 4937 patients with schizophrenia were included in this meta-analysis. The change in the severity of symptoms among patients with schizophrenia was defined as the primary outcome, whereas the safety profiles of the intervention, including the discontinuation rate and adverse events, were defined as secondary outcomes. RESULTS When added to antipsychotic treatments, N-methyl-D-aspartate receptor modulators improved multiple schizophrenia symptoms, particularly negative symptoms, and had satisfactory side effects and safety profile. Among the seven glutamatergic agents analysed, glycine, D-serine and sarcosine had better treatment profiles than other agents, and NMDA receptor co-agonists, as a group, provided a reduction in schizophrenia symptoms compared to antipsychotic treatments without supplementation. Augmentation with N-methyl-D-aspartate receptor modulators was only effective among patients treated with antipsychotics other than clozapine. CONCLUSIONS The results indicate that N-methyl-D-aspartate receptor modulators, particularly with glycine, D-serine and sarcosine, are more beneficial than the placebo in treating schizophrenia, and the effects extended to both positive and negative symptoms, when augmented with antipsychotics other than clozapine.
Collapse
Affiliation(s)
- Kah Kheng Goh
- Department of Psychiatry, Wan-Fang Hospital, Taipei Medical University, Taipei, Taiwan.,Psychiatric Research Center, Wan-Fang Hospital, Taipei Medical University, Taipei, Taiwan
| | - Tzu-Hua Wu
- Psychiatric Research Center, Wan-Fang Hospital, Taipei Medical University, Taipei, Taiwan.,Department of Clinical Pharmacy, School of Pharmacy, College of Pharmacy, Taipei Medical University, Taipei, Taiwan
| | - Chun-Hsin Chen
- Department of Psychiatry, Wan-Fang Hospital, Taipei Medical University, Taipei, Taiwan.,Psychiatric Research Center, Wan-Fang Hospital, Taipei Medical University, Taipei, Taiwan.,Department of Psychiatry, School of Medicine, College of Medicine, Taipei Medical University, Tapei, Taiwan
| | - Mong-Liang Lu
- Department of Psychiatry, Wan-Fang Hospital, Taipei Medical University, Taipei, Taiwan.,Psychiatric Research Center, Wan-Fang Hospital, Taipei Medical University, Taipei, Taiwan.,Department of Psychiatry, School of Medicine, College of Medicine, Taipei Medical University, Tapei, Taiwan
| |
Collapse
|
19
|
Marchi M, Galli G, Magarini FM, Mattei G, Galeazzi GM. Sarcosine as an add-on treatment to antipsychotic medication for people with schizophrenia: a systematic review and meta-analysis of randomized controlled trials. Expert Opin Drug Metab Toxicol 2021; 17:483-493. [PMID: 33538213 DOI: 10.1080/17425255.2021.1885648] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Background: N-methyl-glycine (sarcosine) may improve symptoms of schizophrenia via NMDA-receptor modulation. We undertook a systematic review and meta-analysis to determine the short- and long-term effectiveness of sarcosine for schizophrenia.Research design and methods: The databases Medline, Scopus, EMBASE, Cochrane Library, and PsycINFO were searched. We included six independent randomized controlled trials of sarcosine as add-on treatment to current antipsychotic medication, involving 234 adult participants with schizophrenia, and reporting data on symptom severity. Standardized mean differences (SMDs) were used to assess continuous outcomes.Results: In all of the trials, sarcosine was administered orally at 2 g/day. Treatment with sarcosine did not show a significant effect size at any of the pre-established time points (2, 4, 6, or >6 weeks), due to marked quantitative heterogeneity. However, sarcosine was associated with significant reductions of symptom severity in the subgroups of people with chronic schizophrenia and no treatment resistance (namely, without added-on clozapine) in relation to the SMD after 6 weeks treatment at -0.36 and -0.31, respectively.Conclusions: People with chronic and non-refractory schizophrenia may benefit from the use of sarcosine as an add-on treatment to antipsychotic medication. Due to the good tolerability of this compound, future trials with larger sample sizes appear worthwhile.
Collapse
Affiliation(s)
- Mattia Marchi
- Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - Giacomo Galli
- Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - Federica Maria Magarini
- Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - Giorgio Mattei
- Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy.,Labor, Development and Innovation, Marco Biagi Department of Economics & Marco Biagi Foundation, University of Modena and Reggio Emilia, Modena, Italy
| | - Gian Maria Galeazzi
- Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy.,Center for Neuroscience and Neurotechnology, University of Modena and Reggio Emilia, Modena, Italy
| |
Collapse
|
20
|
Bae M, Roh JD, Kim Y, Kim SS, Han HM, Yang E, Kang H, Lee S, Kim JY, Kang R, Jung H, Yoo T, Kim H, Kim D, Oh H, Han S, Kim D, Han J, Bae YC, Kim H, Ahn S, Chan AM, Lee D, Kim JW, Kim E. SLC6A20 transporter: a novel regulator of brain glycine homeostasis and NMDAR function. EMBO Mol Med 2021; 13:e12632. [PMID: 33428810 PMCID: PMC7863395 DOI: 10.15252/emmm.202012632] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 10/22/2020] [Accepted: 11/19/2020] [Indexed: 12/25/2022] Open
Abstract
Glycine transporters (GlyT1 and GlyT2) that regulate levels of brain glycine, an inhibitory neurotransmitter with co‐agonist activity for NMDA receptors (NMDARs), have been considered to be important targets for the treatment of brain disorders with suppressed NMDAR function such as schizophrenia. However, it remains unclear whether other amino acid transporters expressed in the brain can also regulate brain glycine levels and NMDAR function. Here, we report that SLC6A20A, an amino acid transporter known to transport proline based on in vitro data but is understudied in the brain, regulates proline and glycine levels and NMDAR function in the mouse brain. SLC6A20A transcript and protein levels were abnormally increased in mice carrying a mutant PTEN protein lacking the C terminus through enhanced β‐catenin binding to the Slc6a20a gene. These mice displayed reduced extracellular levels of brain proline and glycine and decreased NMDAR currents. Elevating glycine levels back to normal ranges by antisense oligonucleotide‐induced SLC6A20 knockdown, or the competitive GlyT1 antagonist sarcosine, normalized NMDAR currents and repetitive climbing behavior observed in these mice. Conversely, mice lacking SLC6A20A displayed increased extracellular glycine levels and NMDAR currents. Lastly, both mouse and human SLC6A20 proteins mediated proline and glycine transports, and SLC6A20 proteins could be detected in human neurons. These results suggest that SLC6A20 regulates proline and glycine homeostasis in the brain and that SLC6A20 inhibition has therapeutic potential for brain disorders involving NMDAR hypofunction.
Collapse
Affiliation(s)
- Mihyun Bae
- Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS), Daejeon, Korea
| | - Junyeop Daniel Roh
- Department of Biological Sciences, Korea Advanced Institute for Science and Technology (KAIST), Daejeon, Korea
| | - Youjoung Kim
- Department of Biological Sciences, Korea Advanced Institute for Science and Technology (KAIST), Daejeon, Korea
| | - Seong Soon Kim
- Therapeutics and Biotechnology Division, Korea Research Institute of Chemical Technology (KRICT), Daejeon, Korea
| | - Hye Min Han
- Department of Anatomy and Neurobiology, School of Dentistry, Kyungpook National University, Daegu, Korea
| | - Esther Yang
- Department of Anatomy and Division of Brain Korea 21, Biomedical Science, College of Medicine, Korea University, Seoul, Korea
| | - Hyojin Kang
- Division of National Supercomputing, KISTI, Daejeon, Korea
| | - Suho Lee
- Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS), Daejeon, Korea
| | - Jin Yong Kim
- Department of Anatomy and Division of Brain Korea 21, Biomedical Science, College of Medicine, Korea University, Seoul, Korea
| | - Ryeonghwa Kang
- Department of Biological Sciences, Korea Advanced Institute for Science and Technology (KAIST), Daejeon, Korea
| | - Hwajin Jung
- Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS), Daejeon, Korea
| | - Taesun Yoo
- Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS), Daejeon, Korea
| | - Hyosang Kim
- Department of Biological Sciences, Korea Advanced Institute for Science and Technology (KAIST), Daejeon, Korea
| | - Doyoun Kim
- Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS), Daejeon, Korea
| | - Heejeong Oh
- Department of Biological Sciences, Korea Advanced Institute for Science and Technology (KAIST), Daejeon, Korea
| | - Sungwook Han
- Department of Biological Sciences, Korea Advanced Institute for Science and Technology (KAIST), Daejeon, Korea
| | - Dayeon Kim
- Graduate School of Medical Science and Engineering, KAIST, Daejeon, Korea
| | - Jinju Han
- Graduate School of Medical Science and Engineering, KAIST, Daejeon, Korea
| | - Yong Chul Bae
- Department of Anatomy and Neurobiology, School of Dentistry, Kyungpook National University, Daegu, Korea
| | - Hyun Kim
- Department of Anatomy and Division of Brain Korea 21, Biomedical Science, College of Medicine, Korea University, Seoul, Korea
| | - Sunjoo Ahn
- Therapeutics and Biotechnology Division, Korea Research Institute of Chemical Technology (KRICT), Daejeon, Korea
| | - Andrew M Chan
- School of Biomedical Sciences, The Chinese University of Hong Kong, Hong Kong, Hong Kong SAR, China
| | - Daeyoup Lee
- Department of Biological Sciences, Korea Advanced Institute for Science and Technology (KAIST), Daejeon, Korea
| | - Jin Woo Kim
- Department of Biological Sciences, Korea Advanced Institute for Science and Technology (KAIST), Daejeon, Korea
| | - Eunjoon Kim
- Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS), Daejeon, Korea.,Department of Biological Sciences, Korea Advanced Institute for Science and Technology (KAIST), Daejeon, Korea
| |
Collapse
|
21
|
Pei JC, Luo DZ, Gau SS, Chang CY, Lai WS. Directly and Indirectly Targeting the Glycine Modulatory Site to Modulate NMDA Receptor Function to Address Unmet Medical Needs of Patients With Schizophrenia. Front Psychiatry 2021; 12:742058. [PMID: 34658976 PMCID: PMC8517243 DOI: 10.3389/fpsyt.2021.742058] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Accepted: 09/02/2021] [Indexed: 12/30/2022] Open
Abstract
Schizophrenia is a severe mental illness that affects ~1% of the world's population. It is clinically characterized by positive, negative, and cognitive symptoms. Currently available antipsychotic medications are relatively ineffective in improving negative and cognitive deficits, which are related to a patient's functional outcomes and quality of life. Negative symptoms and cognitive deficits are unmet by the antipsychotic medications developed to date. In recent decades, compelling animal and clinical studies have supported the NMDA receptor (NMDAR) hypofunction hypothesis of schizophrenia and have suggested some promising therapeutic agents. Notably, several NMDAR-enhancing agents, especially those that function through the glycine modulatory site (GMS) of NMDAR, cause significant reduction in psychotic and cognitive symptoms in patients with schizophrenia. Given that the NMDAR-mediated signaling pathway has been implicated in cognitive/social functions and that GMS is a potential therapeutic target for enhancing the activation of NMDARs, there is great interest in investigating the effects of direct and indirect GMS modulators and their therapeutic potential. In this review, we focus on describing preclinical and clinical studies of direct and indirect GMS modulators in the treatment of schizophrenia, including glycine, D-cycloserine, D-serine, glycine transporter 1 (GlyT1) inhibitors, and D-amino acid oxidase (DAO or DAAO) inhibitors. We highlight some of the most promising recently developed pharmacological compounds designed to either directly or indirectly target GMS and thus augment NMDAR function to treat the cognitive and negative symptoms of schizophrenia. Overall, the current findings suggest that indirectly targeting of GMS appears to be more beneficial and leads to less adverse effects than direct targeting of GMS to modulate NMDAR functions. Indirect GMS modulators, especially GlyT1 inhibitors and DAO inhibitors, open new avenues for the treatment of unmet medical needs for patients with schizophrenia.
Collapse
Affiliation(s)
- Ju-Chun Pei
- Department of Psychology, National Taiwan University, Taipei, Taiwan
| | - Da-Zhong Luo
- Department of Psychology, National Taiwan University, Taipei, Taiwan
| | - Shiang-Shin Gau
- Department of Psychology, National Taiwan University, Taipei, Taiwan
| | - Chia-Yuan Chang
- Department of Psychology, National Taiwan University, Taipei, Taiwan.,Neurobiology and Cognitive Science Center, National Taiwan University, Taipei, Taiwan
| | - Wen-Sung Lai
- Department of Psychology, National Taiwan University, Taipei, Taiwan.,Neurobiology and Cognitive Science Center, National Taiwan University, Taipei, Taiwan.,Graduate Institute of Brain and Mind Sciences, National Taiwan University, Taipei, Taiwan
| |
Collapse
|
22
|
Sonnenschein SF, Grace AA. Emerging therapeutic targets for schizophrenia: a framework for novel treatment strategies for psychosis. Expert Opin Ther Targets 2021; 25:15-26. [PMID: 33170748 PMCID: PMC7855878 DOI: 10.1080/14728222.2021.1849144] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Accepted: 11/05/2020] [Indexed: 01/10/2023]
Abstract
Introduction: Antipsychotic drugs are central to the treatment of schizophrenia, but their limitations necessitate improved treatment strategies. Multiple lines of research have implicated glutamatergic dysfunction in the hippocampus as an early source of pathophysiology in schizophrenia. Novel compounds have been designed to treat glutamatergic dysfunction, but they have produced inconsistent results in clinical trials. Areas covered: This review discusses how the hippocampus is thought to drive psychotic symptoms through its influence on the dopamine system. It offers the reader an evaluation of proposed treatment strategies including direct modulation of GABA or glutamate neurotransmission or reducing the deleterious impact of stress on circuit development. Finally, we offer a perspective on aspects of future research that will advance our knowledge and may create new therapeutic opportunities. PubMed was searched for relevant literature between 2010 and 2020 and related studies. Expert opinion: Targeting aberrant excitatory-inhibitory neurotransmission in the hippocampus and its related circuits has the potential to alleviate symptoms and reduce the risk of transition to psychosis if implemented as an early intervention. Longitudinal multimodal brain imaging combined with mechanistic theories generated from animal models can be used to better understand the progression of hippocampal-dopamine circuit dysfunction and heterogeneity in treatment response.
Collapse
Affiliation(s)
| | - Anthony A. Grace
- Departments of Neuroscience, Psychiatry and Psychology, University of Pittsburgh, Pittsburgh, PA, USA
| |
Collapse
|
23
|
Hons J, Zirko R, Vasatova M, Doubek P, Klimova B, Masopust J, Valis M, Kuca K. Impairment of Executive Functions Associated With Lower D-Serine Serum Levels in Patients With Schizophrenia. Front Psychiatry 2021; 12:514579. [PMID: 33854443 PMCID: PMC8039447 DOI: 10.3389/fpsyt.2021.514579] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/27/2019] [Accepted: 02/16/2021] [Indexed: 12/01/2022] Open
Abstract
A core symptom that is frequently linked with dysregulation of glutamatergic neurotransmission in regard to schizophrenia is impairment or damage of executive functioning as a component of cognitive deficiency. The amino acid D-serine plays the role of an endogenous coagonist at the glutamatergic N-methyl-D-aspartate (NMDA) receptor glycine modulatory site. Considerably reduced serum levels of D-serine were found in patients suffering from schizophrenia compared with healthy control participants. An increase in D-serine led to augmented cognitive functionality in patients suffering from schizophrenia who were undergoing clinical trials and given the treatment of first- and second-generation antipsychotics. The study proposed the hypothesis that the D-serine blood serum levels may be linked with the extent of executive functionality in those suffering from the mental illness in question. For the purpose of examining executive function in such patients, the Rey-Osterrieth Complex Figure, Trail Making, and Wisconsin Card Sorting tests were applied (n = 50). High-performance liquid chromatography was used to gauge the total serine and D-serine levels. The extent of damage was examined through neuropsychological tests and was found to be considerably linked to D-serine serum level and the D-serine/total serine ratio (p < 0.05) in the sample being considered. A lower average serum level of D-serine and lower D-serine/total serine ratio were observed in participants with the worst performance compared with those displaying the best performance-this was true when the patients were split into quartile groups based on their results (p < 0.05). The findings of modified D-serine serum levels and the D-serine/total serine ratio linked to the extent of damage in executive functioning indicate that serine metabolism that is coresponsible for NMDA receptor dysfunction has been changed.
Collapse
Affiliation(s)
- Jaromir Hons
- Center for Psychiatry, Regional Hospital Liberec, Liberec, Czechia.,Institute of Health Studies, Technical University of Liberec, Liberec, Czechia
| | - Rastislav Zirko
- Department of Psychiatry, Faculty of Medicine in Hradec Kralove, University Hospital Hradec Kralove and Charles University in Prague, Hradec Kralove, Czechia
| | - Martina Vasatova
- Institute of Clinical Biochemistry and Diagnostics, University Hospital Hradec Kralove and Charles University in Prague, Hradec Kralove, Czechia
| | - Pavel Doubek
- Department of Psychiatry, 1st Faculty of Medicine, General Teaching Hospital and Charles University in Prague, Prague, Czechia
| | - Blanka Klimova
- Department of Neurology, Faculty of Medicine in Hradec Kralove, University Hospital Hradec Kralove and Charles University in Prague, Hradec Kralove, Czechia
| | - Jiri Masopust
- Department of Psychiatry, Faculty of Medicine in Hradec Kralove, University Hospital Hradec Kralove and Charles University in Prague, Hradec Kralove, Czechia.,Department of Neurology, Faculty of Medicine in Hradec Kralove, University Hospital Hradec Kralove and Charles University in Prague, Hradec Kralove, Czechia
| | - Martin Valis
- Department of Neurology, Faculty of Medicine in Hradec Kralove, University Hospital Hradec Kralove and Charles University in Prague, Hradec Kralove, Czechia
| | - Kamil Kuca
- Biomedical Research Center, University Hospital Hradec Kralove, Hradec Kralove, Czechia.,Faculty of Science, University of Hradec Kralove, Hradec Kralove, Czechia
| |
Collapse
|
24
|
Distinct Fecal and Plasma Metabolites in Children with Autism Spectrum Disorders and Their Modulation after Microbiota Transfer Therapy. mSphere 2020; 5:5/5/e00314-20. [PMID: 33087514 PMCID: PMC7580952 DOI: 10.1128/msphere.00314-20] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Despite the prevalence of autism and its extensive impact on our society, no U.S. Food and Drug Administration-approved treatment is available for this complex neurobiological disorder. Based on mounting evidences that support a link between autism and the gut microbiome, we previously performed a pioneering open-label clinical trial using intensive fecal microbiota transplant. The therapy significantly improved gastrointestinal and behavioral symptoms. Comprehensive metabolomic measurements in this study showed that children with autism spectrum disorder (ASD) had different levels of many plasma metabolites at baseline compared to those in typically developing children. Microbiota transfer therapy (MTT) had a systemic effect, resulting in substantial changes in plasma metabolites, driving a number of metabolites to be more similar to those from typically developing children. Our results provide evidence that changes in metabolites are one mechanism of the gut-brain connection mediated by the gut microbiota and offer plausible clinical evidence for a promising autism treatment and biomarkers. Accumulating evidence has strengthened a link between dysbiotic gut microbiota and autism. Fecal microbiota transplant (FMT) is a promising therapy to repair dysbiotic gut microbiota. We previously performed intensive FMT called microbiota transfer therapy (MTT) for children with autism spectrum disorders (ASD) and observed a substantial improvement of gastrointestinal and behavioral symptoms. We also reported modulation of the gut microbiome toward a healthy one. In this study, we report comprehensive metabolite profiles from plasma and fecal samples of the children who participated in the MTT trial. With 619 plasma metabolites detected, we found that the autism group had distinctive metabolic profiles at baseline. Eight metabolites (nicotinamide riboside, IMP, iminodiacetate, methylsuccinate, galactonate, valylglycine, sarcosine, and leucylglycine) were significantly lower in the ASD group at baseline, while caprylate and heptanoate were significantly higher in the ASD group. MTT drove global shifts in plasma profiles across various metabolic features, including nicotinate/nicotinamide and purine metabolism. In contrast, for 669 fecal metabolites detected, when correcting for multiple hypotheses, no metabolite was significantly different at baseline. Although not statistically significant, p-cresol sulfate was relatively higher in the ASD group at baseline, and after MTT, the levels decreased and were similar to levels in typically developing (TD) controls. p-Cresol sulfate levels were inversely correlated with Desulfovibrio, suggesting a potential role of Desulfovibrio on p-cresol sulfate modulation. Further studies of metabolites in a larger ASD cohort, before and after MTT, are warranted, as well as clinical trials of other therapies to address the metabolic changes which MTT was not able to correct. IMPORTANCE Despite the prevalence of autism and its extensive impact on our society, no U.S. Food and Drug Administration-approved treatment is available for this complex neurobiological disorder. Based on mounting evidences that support a link between autism and the gut microbiome, we previously performed a pioneering open-label clinical trial using intensive fecal microbiota transplant. The therapy significantly improved gastrointestinal and behavioral symptoms. Comprehensive metabolomic measurements in this study showed that children with autism spectrum disorder (ASD) had different levels of many plasma metabolites at baseline compared to those in typically developing children. Microbiota transfer therapy (MTT) had a systemic effect, resulting in substantial changes in plasma metabolites, driving a number of metabolites to be more similar to those from typically developing children. Our results provide evidence that changes in metabolites are one mechanism of the gut-brain connection mediated by the gut microbiota and offer plausible clinical evidence for a promising autism treatment and biomarkers.
Collapse
|
25
|
Bayazeid O, Nemutlu E, Eylem CC, İlhan M, Küpeli-Akkol E, Karahan H, Kelicen-Uğur P, Ersoz T, Yalçın FN. Neuroactivity of the naturally occurring aporphine alkaloid, roemerine. Nat Prod Res 2020; 35:6147-6152. [PMID: 33025828 DOI: 10.1080/14786419.2020.1830395] [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] [Indexed: 12/11/2022]
Abstract
Roemerine is a naturally occurring aporphine alkaloid. In this study, we screened a conformer library of Food and Drug Administration (FDA)-approved drugs to identify similar drugs that can assist in identifying the biological targets of roemerine. To assess the neuroactivity in vitro, we measured the levels of cell metabolites, Brain-Derived Neurotrophic Factor (BDNF) and serotonin (5-HT) in SH-SY5Y cell line. By means of structure-based virtual screening, we identified five drugs that are similar to roemerine; mirtazapine, atomoxetine, epinastine, diphenhydramine and orphenadrine. GC-MS metabolomics study revealed that roemerine has a high impact on alanine-aspartate-glutamate pathway in cell lysate and cultured medium. Additionally, roemerine increased intercellular 5-HT level and intracellular BDNF protein expression at 10 µM. In conclusion, roemerine - a major alkaloid in antidepressant-like effect possessing plants (P. lacerum and P. syriacum) - has a neuronal activity through increasing BDNF protein expression and affecting serotonergic and glutamatergic systems in SH-SY5Y cell line.
Collapse
Affiliation(s)
- Omer Bayazeid
- Faculty of Pharmacy, Department of Pharmacognosy, Hacettepe University, Sihhiye, Ankara, Turkey
| | - Emirhan Nemutlu
- Faculty of Pharmacy, Department of Analytical Chemistry, Hacettepe University, Sihhiye, Ankara, Turkey
| | - Cemil Can Eylem
- Faculty of Pharmacy, Department of Analytical Chemistry, Hacettepe University, Sihhiye, Ankara, Turkey
| | - Mert İlhan
- Faculty of Pharmacy, Department of Pharmacognosy, Gazi University, Ankara, Turkey
| | - Esra Küpeli-Akkol
- Faculty of Pharmacy, Department of Pharmacognosy, Gazi University, Ankara, Turkey
| | - Hande Karahan
- Faculty of Pharmacy, Department of Pharmacology, Hacettepe University, Sihhiye, Ankara, Turkey
| | - Pelin Kelicen-Uğur
- Faculty of Pharmacy, Department of Pharmacology, Hacettepe University, Sihhiye, Ankara, Turkey
| | - Tayfun Ersoz
- Faculty of Pharmacy, European University of Lefke, Lefke, Turkey
| | - Funda N Yalçın
- Faculty of Pharmacy, Department of Pharmacognosy, Hacettepe University, Sihhiye, Ankara, Turkey
| |
Collapse
|
26
|
Novel biomarkers and age-related metabolite correlations in plasma and dried blood spots from patients with succinic semialdehyde dehydrogenase deficiency. Orphanet J Rare Dis 2020; 15:261. [PMID: 32967698 PMCID: PMC7510106 DOI: 10.1186/s13023-020-01522-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Accepted: 08/24/2020] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND Previous work has identified age-related negative correlations for γ-hydroxybutyric acid (GHB) and γ-aminobutyric acid (GABA) in plasma of patients with succinic semialdehyde dehydrogenase deficiency (SSADHD). Using plasma and dried blood spots (DBS) collected in an ongoing natural history study, we tested the hypothesis that other biomarkers would follow a similar age-related negative correlation as seen for GHB/GABA. Samples (mixed sex) included: patients (n = 21 unique samples, 1-39.5 yrs) and parallel controls (n = 9 unique samples, 8.4-34.8 yrs). Archival control data (DBS only; n = 171, 0.5-39.9 yrs) was also included. RESULTS Metabolites assessed included amino acids (plasma, DBS) and acylcarnitines, creatine, creatinine, and guanidinoacetate (DBS only). Age-related negative correlations for glycine (plasma, DBS) and sarcosine (N-methylglycine, plasma) were detected, accompanied by elevated proline and decreased levels of succinylacetone, argininosuccinate, formaminoglutamate, and creatinine. Significantly low acylcarnitines were detected in patients across all chain lengths (short-, medium- and long-chain). Significant age-dependent positive correlations for selected acylcarnitines (C6-, C12DC(dicarboxylic)-, C16-, C16:1-, C18:1-, C18:2OH-carnitines) were detected in patients and absent in controls. Receiver operating characteristic (ROC) curves for all binary comparisons revealed argininosuccinate and succinylacetone to be the most discriminating biomarkers (area > 0.92). CONCLUSIONS Age-dependent acylcarnitine correlations may represent metabolic compensation responsive to age-related changes in GHB and GABA. Our study highlights novel biomarkers in SSADHD and expands the metabolic pathophysiology of this rare disorder of GABA metabolism.
Collapse
|
27
|
Bayazeid O, Nemutlu E, Eylem CC, Yalçın FN. Neuroactivity of naturally occurring proaporphine alkaloid, pronuciferine. J Biochem Mol Toxicol 2020; 34:e22601. [PMID: 32852096 DOI: 10.1002/jbt.22601] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Accepted: 08/10/2020] [Indexed: 11/06/2022]
Abstract
Pronuciferine is a naturally occurring proaporphine alkaloid that belongs to isoquinoline alkaloids. The aim of this study is to investigate the neuroactivity of pronuciferine. We assessed the neuroprotective effect of pronuciferine against hydrogen peroxide (H2 O2 )-induced apoptosis in human neuronal SH-SY5Y cells. In addition, we measured the effect of pronuciferine on cell metabolites and brain-derived neurotrophic factor (BDNF) level in SH-SY5Y cells. In vitro result shows that pronuciferine at 10 µM significantly (P < .001) increased the proliferation of SH-SY5Y by 45%, and upon H2 O2 addition, pronuciferine significantly (P < .001) suppressed neuronal death caused by H2 O2 . Gas Chromatography-Mass Spectrometry (GC-MS) metabolomics study revealed that pronuciferine has a high impact on glycine-serine-threonine pathway by changing the intracellular level of serine dimethylglycine, sarcosine, and threonine. Also, pronuciferine increased the intercellular level of aspartic acid, glutamine, and tryptophan. Additionally, pronuciferine significantly (P < .05) increased the intracellular BDNF protein expression at 10 µM. Therefore, pronuciferine is a neuroactive molecule that might act as a neuroprotective agent to prevent apoptosis in neurodegenerative diseases.
Collapse
Affiliation(s)
- Omer Bayazeid
- Department of Pharmacognosy, Faculty of Pharmacy, Hacettepe University, Sihhiye, Ankara, Turkey
| | - Emirhan Nemutlu
- Department of Analytical Chemistry, Faculty of Pharmacy, Hacettepe University, Sihhiye, Ankara, Turkey
| | - Cemil C Eylem
- Department of Analytical Chemistry, Faculty of Pharmacy, Hacettepe University, Sihhiye, Ankara, Turkey
| | - Funda N Yalçın
- Department of Pharmacognosy, Faculty of Pharmacy, Hacettepe University, Sihhiye, Ankara, Turkey
| |
Collapse
|
28
|
Wang Y, Wang X, Yan H, Jiang C, Ge L, Xu T. Bipolar membrane electrodialysis for cleaner production of
N
‐methylated
glycine derivative amino acids. AIChE J 2020. [DOI: 10.1002/aic.17023] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Yaoming Wang
- CAS Key Laboratory of Soft Matter Chemistry, Collaborative Innovation Center of Chemistry for Energy Materials School of Chemistry and Materials Science, University of Science and Technology of China Hefei Anhui P.R. China
| | - Xiaoli Wang
- CAS Key Laboratory of Soft Matter Chemistry, Collaborative Innovation Center of Chemistry for Energy Materials School of Chemistry and Materials Science, University of Science and Technology of China Hefei Anhui P.R. China
| | - Haiyang Yan
- CAS Key Laboratory of Soft Matter Chemistry, Collaborative Innovation Center of Chemistry for Energy Materials School of Chemistry and Materials Science, University of Science and Technology of China Hefei Anhui P.R. China
| | - Chenxiao Jiang
- CAS Key Laboratory of Soft Matter Chemistry, Collaborative Innovation Center of Chemistry for Energy Materials School of Chemistry and Materials Science, University of Science and Technology of China Hefei Anhui P.R. China
| | - Liang Ge
- CAS Key Laboratory of Soft Matter Chemistry, Collaborative Innovation Center of Chemistry for Energy Materials School of Chemistry and Materials Science, University of Science and Technology of China Hefei Anhui P.R. China
| | - Tongwen Xu
- CAS Key Laboratory of Soft Matter Chemistry, Collaborative Innovation Center of Chemistry for Energy Materials School of Chemistry and Materials Science, University of Science and Technology of China Hefei Anhui P.R. China
| |
Collapse
|
29
|
Do damaging variants of SLC6A9, the gene for the glycine transporter 1 (GlyT-1), protect against schizophrenia? Psychiatr Genet 2020; 30:150-152. [PMID: 32796235 DOI: 10.1097/ypg.0000000000000260] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The aim of the investigation was to test whether genetic variants predicted to impair the functionality of SLC6A9, which codes for the GlyT-1 glycine transporter, are protective against schizophrenia. In an exome sequenced sample of 4225 schizophrenia cases and 5834 controls, variants occurring in SLC6A9 were annotated and weights were assigned using GENEVARASSOC. Genotype counts were compared using SCOREASSOC. Variants predicted to be deleterious by SIFT and damaging by PolyPhen were examined. Genotypes at 1:44466494-G/A seemed likely to be erroneous. If these were ignored then there were 15 damaging variants in controls and five in cases. The results are consistent with the hypothesis that variants which damage SLC6A9 are protective against schizophrenia but a larger sample would be required to confirm this.
Collapse
|
30
|
Oh SJ, Fan X. Current understanding on the role of nitric oxide and therapeutic potential of NO supplementation in schizophrenia. Schizophr Res 2020; 222:23-30. [PMID: 32475621 DOI: 10.1016/j.schres.2020.05.050] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Revised: 05/05/2020] [Accepted: 05/18/2020] [Indexed: 10/24/2022]
Affiliation(s)
- SeungJu Jackie Oh
- University of Massachusetts Medical School, Worcester, MA, 01655, United States of America
| | - Xiaoduo Fan
- UMass Memorial Health Care, University of Massachusetts Medical School, United States of America.
| |
Collapse
|
31
|
Chang CH, Lin CH, Liu CY, Chen SJ, Lane HY. Efficacy and cognitive effect of sarcosine (N-methylglycine) in patients with schizophrenia: A systematic review and meta-analysis of double-blind randomised controlled trials. J Psychopharmacol 2020; 34:495-505. [PMID: 32122256 DOI: 10.1177/0269881120908016] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
BACKGROUND Sarcosine (N-methylglycine), a type 1 glycine transporter inhibitor (GlyT1), has shown therapeutic potential for treating schizophrenia; however, studies have reported conflicting results. This meta-analysis aimed to explore the efficacy and cognitive effect of sarcosine for schizophrenia. METHODS In this study, PubMed, Cochrane Systematic Reviews, and Cochrane Collaboration Central Register of Controlled Clinical Trials were searched electronically for double-blinded randomised controlled trials that used sarcosine for treating schizophrenia. We used the published trials up to November 2019 to investigate the efficacy of sarcosine in schizophrenia. We pooled studies by using a random-effect model for comparing sarcosine treatment effects. Patients who were diagnosed with schizophrenia according to the criteria of the Diagnostic and Statistical Manual of Mental Disorders-Fourth Edition were recruited. Clinical improvement and cognitive function scores between baseline and after sarcosine use were compared using the standardised mean difference (SMD) with 95% confidence intervals (CIs). The heterogeneity of the included trials was evaluated through visual inspection of funnel plots and through the I2 statistic. RESULTS We identified seven trials with 326 participants with schizophrenia meeting the inclusion criteria. All these studies evaluated the overall clinical symptoms, and four of them evaluated overall cognitive functions. Sarcosine use achieved more significant effects than the use of its comparators in relieving overall clinical symptoms (SMD = 0.51, CI = 0.26-0.76, p < 0.01). Moreover, studies with the low Positive and Negative Syndrome Scale range of 70-79 showed significant effect size (ES)s of 0.67 (95% CI: 0.03-1.31, p = 0.04). In addition, trials enrolling patients with stable clinical symptoms had significant ESs: 0.53 (95% CI: 0.21-0.85, p < 0.01). Add-on sarcosine combined with first- and second-generation antipsychotics, except clozapine, had a positive effect. For overall cognitive functions, sarcosine showed a positive but insignificant effect compared with its comparators (SMD = 0.27, CI = -0.06 to 0.60, p = 0.10). The effects were correlated with increased female proportions and decreased illness duration, albeit nonsignificantly. CONCLUSIONS The meta-analysis suggests that sarcosine may be associated with treatment effect on overall clinical symptoms in patients with schizophrenia but not cognitive functions.
Collapse
Affiliation(s)
- Chun-Hung Chang
- Institute of Clinical Medical Science, China Medical University, Taichung.,Department of Psychiatry & Brain Disease Research Center, China Medical University Hospital, Taichung.,An Nan Hospital, China Medical University, Tainan
| | - Chieh-Hsin Lin
- Institute of Clinical Medical Science, China Medical University, Taichung.,Graduate Institute of Biomedical Sciences, China Medical University, Taichung.,Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Kaohsiung
| | - Chieh-Yu Liu
- Department of Speech Language Pathology and Audiology, Biostatistical Consulting Lab, National Taipei University of Nursing and Health Sciences, Taipei
| | - Shaw-Ji Chen
- Department of Psychiatry, Mackay Memorial Hospital Taitung Branch, Taitung.,Department of Medicine, Mackay Medical College, New Taipei
| | - Hsien-Yuan Lane
- Institute of Clinical Medical Science, China Medical University, Taichung.,Department of Psychiatry & Brain Disease Research Center, China Medical University Hospital, Taichung.,Graduate Institute of Biomedical Sciences, China Medical University, Taichung.,Department of Psychology, College of Medical and Health Sciences, Asia University, Taichung
| |
Collapse
|
32
|
Mindt M, Walter T, Kugler P, Wendisch VF. Microbial Engineering for Production of N-Functionalized Amino Acids and Amines. Biotechnol J 2020; 15:e1900451. [PMID: 32170807 DOI: 10.1002/biot.201900451] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2019] [Revised: 03/04/2020] [Indexed: 01/04/2023]
Abstract
N-functionalized amines play important roles in nature and occur, for example, in the antibiotic vancomycin, the immunosuppressant cyclosporine, the cytostatic actinomycin, the siderophore aerobactin, the cyanogenic glucoside linamarin, and the polyamine spermidine. In the pharmaceutical and fine-chemical industries N-functionalized amines are used as building blocks for the preparation of bioactive molecules. Processes based on fermentation and on enzyme catalysis have been developed to provide sustainable manufacturing routes to N-alkylated, N-hydroxylated, N-acylated, or other N-functionalized amines including polyamines. Metabolic engineering for provision of precursor metabolites is combined with heterologous N-functionalizing enzymes such as imine or ketimine reductases, opine or amino acid dehydrogenases, N-hydroxylases, N-acyltransferase, or polyamine synthetases. Recent progress and applications of fermentative processes using metabolically engineered bacteria and yeasts along with the employed enzymes are reviewed and the perspectives on developing new fermentative processes based on insight from enzyme catalysis are discussed.
Collapse
Affiliation(s)
- Melanie Mindt
- Genetics of Prokaryotes, Biology and CeBiTec, Bielefeld University, Bielefeld, 33615, Germany.,BU Bioscience, Wageningen University and Research, Wageningen, 6708 PB, The Netherlands
| | - Tatjana Walter
- Genetics of Prokaryotes, Biology and CeBiTec, Bielefeld University, Bielefeld, 33615, Germany
| | - Pierre Kugler
- Genetics of Prokaryotes, Biology and CeBiTec, Bielefeld University, Bielefeld, 33615, Germany
| | - Volker F Wendisch
- Genetics of Prokaryotes, Biology and CeBiTec, Bielefeld University, Bielefeld, 33615, Germany
| |
Collapse
|
33
|
Tarasov VV, Svistunov AA, Chubarev VN, Sologova SS, Mukhortova P, Levushkin D, Somasundaram SG, Kirkland CE, Bachurin SO, Aliev G. Alterations of Astrocytes in the Context of Schizophrenic Dementia. Front Pharmacol 2020; 10:1612. [PMID: 32116664 PMCID: PMC7020441 DOI: 10.3389/fphar.2019.01612] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Accepted: 12/10/2019] [Indexed: 12/19/2022] Open
Abstract
The levels of the astrocyte markers (GFAP, S100B) were increased unevenly in patients with schizophrenia. Reactive astrogliosis was found in approximately 70% of patients with schizophrenia. The astrocytes play a major role in etiology and pathogenesis of schizophrenia. Astrocytes produce the components that altered in schizophrenia extracellular matrix system which are involved in inflammation, functioning of interneurons, glio-, and neurotransmitter system, especially glutamate system. Astrocytes activate the interneurons through glutamate release and ATP. Decreased expression of astrocyte glutamate transporters was observed in patients with schizophrenia. Astrocytes influence on N-methyl-d-aspartate (NMDA) receptors via D-serine, an agonist of the glycine-binding site of NMDA receptors, and kynurenic acid, an endogenous antagonist. NMDA receptors, on its turn, control the impulses of dopamine neurons. Therefore following theories of schizophrenia are proposed. They are a) activation of astrocytes for neuroinflammation, b) glutamate and dopamine theory, as astrocyte products control the activity of NMDA receptors, which influence on the dopamine neurons.
Collapse
Affiliation(s)
- Vadim V Tarasov
- I.M. Sechenov First Moscow State Medical University (Sechenov University), Moscow, Russia
| | - Andrey A Svistunov
- I.M. Sechenov First Moscow State Medical University (Sechenov University), Moscow, Russia
| | - Vladimir N Chubarev
- I.M. Sechenov First Moscow State Medical University (Sechenov University), Moscow, Russia
| | - Susanna S Sologova
- I.M. Sechenov First Moscow State Medical University (Sechenov University), Moscow, Russia
| | - Polina Mukhortova
- I.M. Sechenov First Moscow State Medical University (Sechenov University), Moscow, Russia
| | - Dmitrii Levushkin
- I.M. Sechenov First Moscow State Medical University (Sechenov University), Moscow, Russia
| | - Siva G Somasundaram
- Department of Biological Sciences, Salem University, Salem, WV, United States
| | - Cecil E Kirkland
- Department of Biological Sciences, Salem University, Salem, WV, United States
| | - Sergey O Bachurin
- Institute of Physiologically Active Compounds Russian Academy of Sciences, Chernogolovka, Russia
| | - Gjumrakch Aliev
- I.M. Sechenov First Moscow State Medical University (Sechenov University), Moscow, Russia.,Institute of Physiologically Active Compounds Russian Academy of Sciences, Chernogolovka, Russia.,Federal State Budgetary Institution, Research Institute of Human Morphology, Russian Federation, Moscow, Russia.,GALLY International Research Institute, San Antonio, TX, United States
| |
Collapse
|
34
|
Ali JS, Ain NU, Naz S, Zia M. Biomarker selection and imaging design in cancer: A link with biochemical pathways for imminent engineering. Heliyon 2020; 6:e03340. [PMID: 32055737 PMCID: PMC7005466 DOI: 10.1016/j.heliyon.2020.e03340] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Revised: 05/27/2019] [Accepted: 01/29/2020] [Indexed: 01/15/2023] Open
Abstract
Malignant cells reprogram metabolic pathways to meet the demands of growth and proliferation. These altered manners of metabolism are now identified as hallmarks of cancer. Studies have revealed tumor cells alter specific pathways such as glycolysis, fatty acid synthesis and amino acid synthesis to support their proliferation. In this review, we provide a theoretical framework to understand metabolic reprogramming and the mechanisms accompanying distorted metabolism to tumor progression. How these alterations will be assisting in cancer diagnostics and advances in standard techniques in marker identification and imagining are also discussed.
Collapse
Affiliation(s)
| | | | | | - Muhammad Zia
- Department of Biotechnology, Quaid-i-Azam University Islamabad 45320 Pakistan
| |
Collapse
|
35
|
Yao L, Wang Z, Deng D, Yan R, Ju J, Zhou Q. The impact of D-cycloserine and sarcosine on in vivo frontal neural activity in a schizophrenia-like model. BMC Psychiatry 2019; 19:314. [PMID: 31653237 PMCID: PMC6814999 DOI: 10.1186/s12888-019-2306-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Accepted: 09/30/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND N-methyl-D-aspartate receptor (NMDAR) hypofunction has been proposed to underlie the pathogenesis of schizophrenia. Specifically, reduced function of NMDARs leads to altered balance between excitation and inhibition which further drives neural network malfunctions. Clinical studies suggested that NMDAR modulators (glycine, D-serine, D-cycloserine and glycine transporter inhibitors) may be beneficial in treating schizophrenia patients. Preclinical evidence also suggested that these NMDAR modulators may enhance synaptic NMDAR function and synaptic plasticity in brain slices. However, an important issue that has not been addressed is whether these NMDAR modulators modulate neural activity/spiking in vivo. METHODS By using in vivo calcium imaging and single unit recording, we tested the effect of D-cycloserine, sarcosine (glycine transporter 1 inhibitor) and glycine, on schizophrenia-like model mice. RESULTS In vivo neural activity is significantly higher in the schizophrenia-like model mice, compared to control mice. D-cycloserine and sarcosine showed no significant effect on neural activity in the schizophrenia-like model mice. Glycine induced a large reduction in movement in home cage and reduced in vivo brain activity in control mice which prevented further analysis of its effect in schizophrenia-like model mice. CONCLUSIONS We conclude that there is no significant impact of the tested NMDAR modulators on neural spiking in the schizophrenia-like model mice.
Collapse
Affiliation(s)
- Lulu Yao
- 0000 0001 2256 9319grid.11135.37School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, Shenzhen, 518055 China
| | - Zongliang Wang
- 0000 0001 2256 9319grid.11135.37School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, Shenzhen, 518055 China
| | - Di Deng
- 0000 0001 2256 9319grid.11135.37School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, Shenzhen, 518055 China
| | - Rongzhen Yan
- 0000 0001 2256 9319grid.11135.37School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, Shenzhen, 518055 China
| | - Jun Ju
- 0000 0001 2256 9319grid.11135.37School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, Shenzhen, 518055 China
| | - Qiang Zhou
- School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, Shenzhen, 518055, China. .,State Key Laboratory of Chemical Oncogenomics, Key Laboratory of Chemical Genomics, Peking University Shenzhen Graduate School, Shenzhen, 518055, China.
| |
Collapse
|
36
|
Kynurenines and the Endocannabinoid System in Schizophrenia: Common Points and Potential Interactions. Molecules 2019; 24:molecules24203709. [PMID: 31619006 PMCID: PMC6832375 DOI: 10.3390/molecules24203709] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Revised: 10/09/2019] [Accepted: 10/14/2019] [Indexed: 12/15/2022] Open
Abstract
Schizophrenia, which affects around 1% of the world’s population, has been described as a complex set of symptoms triggered by multiple factors. However, the exact background mechanisms remain to be explored, whereas therapeutic agents with excellent effectivity and safety profiles have yet to be developed. Kynurenines and the endocannabinoid system (ECS) play significant roles in both the development and manifestation of schizophrenia, which have been extensively studied and reviewed previously. Accordingly, kynurenines and the ECS share multiple features and mechanisms in schizophrenia, which have yet to be reviewed. Thus, the present study focuses on the main common points and potential interactions between kynurenines and the ECS in schizophrenia, which include (i) the regulation of glutamatergic/dopaminergic/γ-aminobutyric acidergic neurotransmission, (ii) their presence in astrocytes, and (iii) their role in inflammatory mechanisms. Additionally, promising pharmaceutical approaches involving the kynurenine pathway and the ECS will be reviewed herein.
Collapse
|
37
|
Pei JC, Hung WL, Lin BX, Shih MH, Lu LY, Luo DZ, Tai HC, Studer V, Min MY, Lai WS. Therapeutic potential and underlying mechanism of sarcosine (N-methylglycine) in N-methyl-D-aspartate (NMDA) receptor hypofunction models of schizophrenia. J Psychopharmacol 2019; 33:1288-1302. [PMID: 31294644 DOI: 10.1177/0269881119856558] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
BACKGROUND Compelling animal and clinical studies support the N-methyl-D-aspartate receptor (NMDAR) hypofunction hypothesis of schizophrenia and suggest promising pharmacological agents to ameliorate negative and cognitive symptoms of schizophrenia, including sarcosine, a glycine transporter-1 inhibitor. AIMS AND METHODS It is imperative to evaluate the therapeutic potential of sarcosine in animal models, which provide indispensable tools for testing drug effects in detail and elucidating the underlying mechanisms. In this study, a series of seven experiments was conducted to investigate the effect of sarcosine in ameliorating behavioral deficits and the underlying mechanism in pharmacological (i.e., MK-801-induced) and genetic (i.e., serine racemase-null mutant (SR-/-) mice) NMDAR hypofunction models. RESULTS In Experiment 1, the acute administration of 500/1000 mg/kg sarcosine (i.p.) had no adverse effects on motor function and serum biochemical responses. In Experiments 2-4, sarcosine significantly alleviated MK-801-induced (0.2 mg/kg) brain abnormalities and behavioral deficits in MK-801-induced and SR-/- mouse models. In Experiment 5, the injection of sarcosine enhanced CSF levels of glycine and serine in rat brain. In Experiments 6-7, we show for the first time that sarcosine facilitated NMDAR-mediated hippocampal field excitatory postsynaptic potentials and influenced the movement of surface NMDARs at extrasynaptic sites. CONCLUSIONS Sarcosine effectively regulated the surface trafficking of NMDARs, NMDAR-evoked electrophysiological activity, brain glycine levels and MK-801-induced abnormalities in the brain, which contributed to the amelioration of behavioral deficits in mouse models of NMDAR hypofunction.
Collapse
Affiliation(s)
- Ju-Chun Pei
- Department of Psychology, National Taiwan University, Taipei, Taiwan
| | - Wei-Li Hung
- Department of Psychology, National Taiwan University, Taipei, Taiwan
| | - Bei-Xuan Lin
- Institute of Zoology, National Taiwan University, Taipei, Taiwan
| | - Min-Han Shih
- Department of Chemistry, National Taiwan University, Taipei, Taiwan
| | - Liang-Yin Lu
- Department of Psychology, National Taiwan University, Taipei, Taiwan
| | - Da-Zhong Luo
- Department of Psychology, National Taiwan University, Taipei, Taiwan
| | - Hwan-Ching Tai
- Department of Chemistry, National Taiwan University, Taipei, Taiwan
| | - Vincent Studer
- Interdisciplinary Institute for Neuroscience, University of Bordeaux, Bordeaux, France.,French National Center for Scientific Research (CNRS), Bordeaux, France
| | - Ming-Yuan Min
- Institute of Zoology, National Taiwan University, Taipei, Taiwan.,Graduate Institute of Brain and Mind Sciences, National Taiwan University, Taipei, Taiwan.,Neurobiology and Cognitive Science Center, National Taiwan University, Taipei, Taiwan
| | - Wen-Sung Lai
- Department of Psychology, National Taiwan University, Taipei, Taiwan.,Graduate Institute of Brain and Mind Sciences, National Taiwan University, Taipei, Taiwan.,Neurobiology and Cognitive Science Center, National Taiwan University, Taipei, Taiwan
| |
Collapse
|
38
|
Zhand N, Attwood DG, Harvey PD. Glutamate modulators for treatment of schizophrenia. ACTA ACUST UNITED AC 2019. [DOI: 10.1016/j.pmip.2019.02.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
|
39
|
Mindt M, Heuser M, Wendisch VF. Xylose as preferred substrate for sarcosine production by recombinant Corynebacterium glutamicum. BIORESOURCE TECHNOLOGY 2019; 281:135-142. [PMID: 30818264 DOI: 10.1016/j.biortech.2019.02.084] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Revised: 02/17/2019] [Accepted: 02/18/2019] [Indexed: 06/09/2023]
Abstract
The aim of this work was to study the fermentative production of the N-methylated amino acid sarcosine by C. glutamicum. Characterization of the imine reductase DpkA from Pseudomonas putida revealed that it catalyses N-methylamination of glyoxylate to sarcosine. Heterologous expression of dpkA in a C. glutamicum strain engineered for glyoxylate overproduction enabled fermentative production of sarcosine from sugars and monomethylamine. Glucose-based fermentation reached sarcosine production titers of 2.4 ± 0.1 g L-1. Sarcosine production based on the second generation feedstocks xylose and arabinose led to higher product titers of 2.7 ± 0.1 g L-1 and 3.4 ± 0.3 g L-1, respectively, than glucose-based production. Optimization of production conditions with xylose and potassium acetate blends increased sarcosine titers to 8.7 ± 0.2 g L-1 with a yield of 0.25 g g-1. This is the first example in which a C. glutamicum process using lignocellulosic pentoses is superior to glucose-based production.
Collapse
Affiliation(s)
- Melanie Mindt
- Genetics of Prokaryotes, Faculty of Biology & CeBiTec, Bielefeld University, Universitätsstr. 25, 33615 Bielefeld, Germany
| | - Maria Heuser
- Genetics of Prokaryotes, Faculty of Biology & CeBiTec, Bielefeld University, Universitätsstr. 25, 33615 Bielefeld, Germany
| | - Volker F Wendisch
- Genetics of Prokaryotes, Faculty of Biology & CeBiTec, Bielefeld University, Universitätsstr. 25, 33615 Bielefeld, Germany.
| |
Collapse
|
40
|
Lin CH, Lane HY. The Role of N-Methyl-D-Aspartate Receptor Neurotransmission and Precision Medicine in Behavioral and Psychological Symptoms of Dementia. Front Pharmacol 2019; 10:540. [PMID: 31191302 PMCID: PMC6539199 DOI: 10.3389/fphar.2019.00540] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2018] [Accepted: 04/29/2019] [Indexed: 12/16/2022] Open
Abstract
While the world’s population is aging, the prevalence of dementia and the associated behavioral and psychological symptoms of dementia (BPSD) rises rapidly. BPSD are associated with worsening of cognitive function and poorer prognosis. No pharmacological treatment has been approved to be beneficial for BPSD to date. Dysfunction of the N-methyl-D-aspartate receptor (NMDAR)-related neurotransmission leads to cognitive impairment and behavioral changes, both of which are core symptoms of BPSD. Memantine, an NMDAR partial antagonist, is used to treat moderate to severe Alzheimer’s disease (AD). On the other hand, a D-amino acid oxidase inhibitor improved early-phase AD. Whether to enhance or to attenuate the NMDAR may depend on the phases of dementia. It will be valuable to develop biomarkers indicating the activity of NMDAR, particularly in BPSD. In addition, recent reports suggest that gender difference exists in the treatment of dementia. Selecting subpopulations of patients with BPSD who are prone to improvement with treatment would be important. We reviewed literatures regarding the treatment of BPSD, focusing on the NMDAR-related modulation and precision medicine. Future studies examining the NMDAR modulators with the aid of potential biomarkers to tailor the treatment for individualized patients with BPSD are warranted.
Collapse
Affiliation(s)
- Chieh-Hsin Lin
- Department of Psychiatry, Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Kaohsiung, Taiwan.,School of Medicine, Chang Gung University, Taoyuan, Taiwan.,Graduate Institute of Biomedical Sciences, China Medical University, Taichung, Taiwan
| | - Hsien-Yuan Lane
- Graduate Institute of Biomedical Sciences, China Medical University, Taichung, Taiwan.,Department of Psychiatry and Brain Disease Research Center, China Medical University Hospital, Taichung, Taiwan.,Department of Psychology, College of Medical and Health Sciences, Asia University, Taichung, Taiwan
| |
Collapse
|
41
|
Insights on current and novel antipsychotic mechanisms from the MAM model of schizophrenia. Neuropharmacology 2019; 163:107632. [PMID: 31077730 DOI: 10.1016/j.neuropharm.2019.05.009] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Revised: 04/25/2019] [Accepted: 05/07/2019] [Indexed: 12/18/2022]
Abstract
Current antipsychotic drugs (APDs) act on D2 receptors, and preclinical studies demonstrate that repeated D2 antagonist administration downregulates spontaneously active DA neurons by producing overexcitation-induced inactivation of firing (depolarization block). Animal models of schizophrenia based on the gestational MAM administration produces offspring with adult phenotypes consistent with schizophrenia, including ventral hippocampal hyperactivity and a DA neuron overactivity. The MAM model reveals that APDs act differently in a hyperdopamineregic system compared to a normal one, including rapid onset of depolarization block in response to acute D2 antagonist administration and downregulation of DA neuron population activity following acute and repeated D2 partial agonist administration, none of which are observed in normal rats. Novel target compounds have been developed based on the theory that glutamatergic dysfunction is central to schizophrenia pathology. Despite showing promise in preclinical research, none of the novel drugs succeeded in clinical trials. However, preclinical research is generally performed in normal, drug-naïve rats, whereas models with disease-relevant pathology and prior APD exposure may improve the predictive validity of preclinical research. Indeed, in MAM rats, chronic D2 antagonist treatment leads to persistent DA supersensitivity that interferes with the response to drugs that target upstream pathology. Moreover, MAM rats revealed that the peri-pubertal period is a stress-sensitive window that can be targeted to prevent the development of MAM pathology in adulthood. Neurodevelopmental models, such as the MAM model, can thus be used to test potential pharmacotherapies that may be able to treat schizophrenia in early stages of the disease. This article is part of the issue entitled 'Special Issue on Antipsychotics'.
Collapse
|
42
|
Guercio GD, Thomas ME, Cisneros-Franco JM, Voss P, Panizzutti R, de Villers-Sidani E. Improving cognitive training for schizophrenia using neuroplasticity enhancers: Lessons from decades of basic and clinical research. Schizophr Res 2019; 207:80-92. [PMID: 29730045 DOI: 10.1016/j.schres.2018.04.028] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Revised: 04/13/2018] [Accepted: 04/17/2018] [Indexed: 01/29/2023]
Abstract
Mounting evidence indicates that schizophrenia is a disorder that stems from maladaptive plasticity within neural circuits and produces broad cognitive deficits leading to loss of autonomy. A large number of studies have identified abnormalities spanning many neurotransmitter systems in schizophrenia, and as a result, a variety of drugs have been developed to attempt to treat these abnormalities and enhance cognition. Unfortunately, positive results have been limited so far. This may be in part because the scope of abnormalities in the schizophrenic brain requires a treatment capable of engaging many different neurotransmitter systems. One approach to achieving this kind of treatment has been to use neuroplasticity-based computerized cognitive training programs to stimulate the formation of more adaptive circuits. Although the number of studies implementing this approach has increased exponentially in recent years, effect sizes for cognitive gains have been modest and adherence to treatment remains an important challenge in many studies, as patients are often required to train for 40 h or more. In the present paper, we argue that cognitive training protocols will benefit from the addition of cognitive enhancers to produce more robust and longer lasting targeted neuroplasticity. Indeed, recent data from animal studies have provided support for combining plasticity-enhancing drugs with tailored behavioral training paradigms to restore normal function within dysfunctioning neural circuits. The advantages and challenges of applying this approach to patients with schizophrenia will be discussed.
Collapse
Affiliation(s)
- G D Guercio
- Biomedical Sciences Institute, Federal University of Rio de Janeiro, RJ, Brazil; Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, QC, Canada.
| | - M E Thomas
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, QC, Canada
| | - J M Cisneros-Franco
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, QC, Canada
| | - P Voss
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, QC, Canada
| | - R Panizzutti
- Biomedical Sciences Institute, Federal University of Rio de Janeiro, RJ, Brazil
| | - E de Villers-Sidani
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, QC, Canada.
| |
Collapse
|
43
|
Kantrowitz JT. N-methyl-d-aspartate-type glutamate receptor modulators and related medications for the enhancement of auditory system plasticity in schizophrenia. Schizophr Res 2019; 207:70-79. [PMID: 29459050 DOI: 10.1016/j.schres.2018.02.003] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Revised: 01/30/2018] [Accepted: 02/02/2018] [Indexed: 12/14/2022]
Abstract
Deficits in N-methyl-d-aspartate-type (NMDAR) function contribute to cognitive deficits in schizophrenia, particularly dysfunction in neuroplasticity, defined as reduced learning during training on exercises that place implicit, increasing demands on early sensory (auditory and visual) information processing. Auditory mismatch negativity (MMN) can be both a target engagement biomarker for the NMDAR and a proxy measure of neurophysiological plasticity. This review covers the evidence for using NMDAR modulator and related compounds for enhancement of cognition, with a particular focus on early auditory processing/plasticity. Compounds covered include glycine site agonists, glycine and system A-type transporter inhibitors, d-amino acid oxidase inhibitors, memantine and nicotinic alpha-7 acetylcholine receptor agonists. As opposed to daily treatment studies focusing on schizophrenia in general, intermittent, non-daily treatment combining NMDAR modulators with neuroplasticity-based paradigms, using MMN as target-engagement biomarkers show promise as treatments to both remediate plasticity deficits and overall functional deficits.
Collapse
Affiliation(s)
- Joshua T Kantrowitz
- Schizophrenia Research Center, Nathan Kline Institute for Psychiatric Research, Orangeburg, NY 10962, USA; Division of Experimental Therapeutics, Department of Psychiatry, Columbia University, New York, NY 10032, USA.
| |
Collapse
|
44
|
Lin CH, Lane HY. Early Identification and Intervention of Schizophrenia: Insight From Hypotheses of Glutamate Dysfunction and Oxidative Stress. Front Psychiatry 2019; 10:93. [PMID: 30873052 PMCID: PMC6400883 DOI: 10.3389/fpsyt.2019.00093] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/09/2018] [Accepted: 02/08/2019] [Indexed: 12/22/2022] Open
Abstract
Schizophrenia is a severe mental disorder which leads to functional deterioration. Early detection and intervention are vital for better prognosis. However, the diagnosis of schizophrenia still depends on clinical observation to date. Without reliable biomarkers, schizophrenia is difficult to detect in its early phase. Further, there is no approved medication for prodromal schizophrenia because current antipsychotics fail to show satisfactory efficacy and safety. Therefore, to develop an effective early diagnostic and therapeutic approach for schizophrenia, especially in its prodromal phase, is crucial. Glutamate signaling dysfunction and dysregulation of oxidative stress have been considered to play important roles in schizophrenic prodrome. The N-methyl-D-aspartate receptor (NMDAR) is one of three types of ionotropic glutamate receptors. In this article, we reviewed literature regarding NMDAR hypofunction, oxidative stress, and the linkage between both in prodromal schizophrenia. The efficacy of NMDAR enhancers such as D-amino acid oxidase inhibitor was addressed. Finally, we highlighted potential biomarkers related to NMDAR and oxidative stress regulation, and therefore suggested the strategies of early detection and intervention of prodromal schizophrenia. Future larger-scale studies combining biomarkers and novel drug development for early psychosis are warranted.
Collapse
Affiliation(s)
- Chieh-Hsin Lin
- Department of Psychiatry, Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Kaohsiung, Taiwan
- School of Medicine, Chang Gung University, Taoyuan, Taiwan
- Graduate Institute of Biomedical Sciences, China Medical University, Taichung, Taiwan
| | - Hsien-Yuan Lane
- Graduate Institute of Biomedical Sciences, China Medical University, Taichung, Taiwan
- Department of Psychiatry and Brain Disease Research Center, China Medical University Hospital, Taichung, Taiwan
- Department of Psychology, College of Medical and Health Sciences, Asia University, Taichung, Taiwan
| |
Collapse
|
45
|
The past and future of novel, non-dopamine-2 receptor therapeutics for schizophrenia: A critical and comprehensive review. J Psychiatr Res 2019; 108:57-83. [PMID: 30055853 DOI: 10.1016/j.jpsychires.2018.07.006] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Revised: 06/13/2018] [Accepted: 07/12/2018] [Indexed: 01/28/2023]
Abstract
Since the discovery of chlorpromazine in the 1950's, antipsychotic drugs have been the cornerstone of treatment of schizophrenia, and all attenuate dopamine transmission at the dopamine-2 receptor. Drug development for schizophrenia since that time has led to improvements in side effects and tolerability, and limited improvements in efficacy, with the exception of clozapine. However, the reasons for clozapine's greater efficacy remain unclear, despite the great efforts and resources invested therewith. We performed a comprehensive review of the literature to determine the fate of previously tested, non-dopamine-2 receptor experimental treatments. Overall we included 250 studies in the review from the period 1970 to 2017 including treatments with glutamatergic, serotonergic, cholinergic, neuropeptidergic, hormone-based, dopaminergic, metabolic, vitamin/naturopathic, histaminergic, infection/inflammation-based, and miscellaneous mechanisms. Despite there being several promising targets, such as allosteric modulation of the NMDA and α7 nicotinic receptors, we cannot confidently state that any of the mechanistically novel experimental treatments covered in this review are definitely effective for the treatment of schizophrenia and ready for clinical use. We discuss potential reasons for the relative lack of progress in developing non-dopamine-2 receptor treatments for schizophrenia and provide recommendations for future efforts pursuing novel drug development for schizophrenia.
Collapse
|
46
|
Merk W, Kucia K, Mędrala T, Kowalczyk M, Owczarek A, Kowalski J. Association study of the excitatory amino acid transporter 2 (EAAT2) and glycine transporter 1 (GlyT1) gene polymorphism with schizophrenia in a Polish population. Neuropsychiatr Dis Treat 2019; 15:989-1000. [PMID: 31118638 PMCID: PMC6499478 DOI: 10.2147/ndt.s194924] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Accepted: 02/14/2019] [Indexed: 01/28/2023] Open
Abstract
Background: Excitatory amino acid transporter 2 encoded by SLC1A2 is responsible for approximately 90% of glutamate uptake. Glycine transporter 1, encoded by SLC6A9, is responsible for maintaining a low concentration of the N-methyl-D-aspartate receptor (NMDAR) co-agonist - glycine in the synaptic cleft, suggesting its participation in the development of the NMDARs hypofunction described in schizophrenia. Aim: The aim of this study was to evaluate whether the functional polymorphism-181 A/C (rs4354668) of the SLC1A2 and the rs2486001 (IVS3+411 G/A) in the SLC6A9 are involved in schizophrenia development and its clinical picture in the Polish population. Methods: The study group consisted of 393 unrelated Caucasian patients (157 [39.9%] females and 236 [60.1%] males; mean age 41±12) diagnosed with schizophrenia according to the DSM-5, and 462 healthy controls. The results of the Positive and Negative Syndrome Scale (PANSS) were presented in the five-dimensional model. Polymorphisms of SLC1A2 and SLC6A9 were genotyped with the use of PCR-RFLP assay. Results: There were no statistically significant differences in the frequency of genotypes and alleles between the patients and controls for SLC1A2 and SLC6A9 polymorphisms in either the entire sample or after stratification according to gender. In the haplotype analysis, men with CA haplotype had more than 1.5 higher risk to develop schizophrenia than women (OR=1.63 [95% CI=1.17-2.27, p<0.05]). The influence of gender, genotypes of both analyzed polymorphisms and gender x genotype interactions on individual dimensions of the PANSS scale has not been observed. Also, there was no association of either polymorphism with suicide attempts. Conclusion: The results of the present study did not indicate an association of polymorphism-181 A/C (rs4354668) in SLC1A2 and rs2486001 in SLC6A9 with onset of schizophrenia and its psychopathology in a Polish population.
Collapse
Affiliation(s)
- Wojciech Merk
- Department of Psychiatry and Psychotherapy, School of Medicine in Katowice, Medical University of Silesia, Katowice, Poland
| | - Krzysztof Kucia
- Department of Psychiatry and Psychotherapy, School of Medicine in Katowice, Medical University of Silesia, Katowice, Poland
| | - Tomasz Mędrala
- Department of Psychiatry and Psychotherapy, School of Medicine in Katowice, Medical University of Silesia, Katowice, Poland
| | - Małgorzata Kowalczyk
- Department of Medical Genetics, School of Pharmacy with the Division of Laboratory Medicine in Sosnowiec, Medical University of Silesia, Katowice, Poland
| | - Aleksander Owczarek
- Division of Statistics, Department of Instrumental Analysis, School of Pharmacy with the Division of Laboratory Medicine in Sosnowiec, Medical University of Silesia, Katowice, Poland.,Department of Instrumental Analysis, School of Pharmacy with the Division of Laboratory Medicine in Sosnowiec, Medical University of Silesia, Katowice, Poland
| | - Jan Kowalski
- Department of Medical Genetics, School of Pharmacy with the Division of Laboratory Medicine in Sosnowiec, Medical University of Silesia, Katowice, Poland
| |
Collapse
|
47
|
Uhlirova D, Stankova M, Docekalova M, Hosnedlova B, Kepinska M, Ruttkay-Nedecky B, Ruzicka J, Fernandez C, Milnerowicz H, Kizek R. A Rapid Method for the Detection of Sarcosine Using SPIONs/Au/CS/SOX/NPs for Prostate Cancer Sensing. Int J Mol Sci 2018; 19:E3722. [PMID: 30467297 PMCID: PMC6320840 DOI: 10.3390/ijms19123722] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Revised: 11/16/2018] [Accepted: 11/18/2018] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Sarcosine is an amino acid that is formed by methylation of glycine and is present in trace amounts in the body. Increased sarcosine concentrations in blood plasma and urine are manifested in sarcosinemia and in some other diseases such as prostate cancer. For this purpose, sarcosine detection using the nanomedicine approach was proposed. In this study, we have prepared superparamagnetic iron oxide nanoparticles (SPIONs) with different modified surface area. Nanoparticles (NPs) were modified by chitosan (CS), and sarcosine oxidase (SOX). SPIONs without any modification were taken as controls. Methods and Results: The obtained NPs were characterized by physicochemical methods. The size of the NPs determined by the dynamic light scattering method was as follows: SPIONs/Au/NPs (100⁻300 nm), SPIONs/Au/CS/NPs (300⁻700 nm), and SPIONs/Au/CS/SOX/NPs (600⁻1500 nm). The amount of CS deposited on the NP surface was found to be 48 mg/mL for SPIONs/Au/CS/NPs and 39 mg/mL for SPIONs/Au/CS/SOX/NPs, and repeatability varied around 10%. Pseudo-peroxidase activity of NPs was verified using sarcosine, horseradish peroxidase (HRP) and 3,3',5,5'-tetramethylbenzidine (TMB) as a substrate. For TMB, all NPs tested evinced substantial pseudo-peroxidase activity at 650 nm. The concentration of SPIONs/Au/CS/SOX/NPs in the reaction mixture was optimized to 0⁻40 mg/mL. Trinder reaction for sarcosine detection was set up at 510 nm at an optimal reaction temperature of 37 °C and pH 8.0. The course of the reaction was linear for 150 min. The smallest amount of NPs that was able to detect sarcosine was 0.2 mg/well (200 µL of total volume) with the linear dependence y = 0.0011x - 0.0001 and the correlation coefficient r = 0.9992, relative standard deviation (RSD) 6.35%, limit of detection (LOD) 5 µM. The suggested method was further validated for artificial urine analysis (r = 0.99, RSD 21.35%, LOD 18 µM). The calculation between the detected and applied concentrations showed a high correlation coefficient (r = 0.99). NPs were tested for toxicity and no significant growth inhibition was observed in any model system (S. cerevisiae, S. aureus, E. coli). The hemolytic activity of the prepared NPs was similar to that of the phosphate buffered saline (PBS) control. The reaction system was further tested on real urine specimens. Conclusion: The proposed detection system allows the analysis of sarcosine at micromolar concentrations and to monitor changes in its levels as a potential prostate cancer marker. The whole system is suitable for low-cost miniaturization and point-of-care testing technology and diagnostic systems. This system is simple, inexpensive, and convenient for screening tests and telemedicine applications.
Collapse
Affiliation(s)
- Dagmar Uhlirova
- Department of Research and Development, Prevention Medicals, Tovarni 342, 742 13 Studenka-Butovice, Czech Republic.
| | - Martina Stankova
- Department of Research and Development, Prevention Medicals, Tovarni 342, 742 13 Studenka-Butovice, Czech Republic.
| | - Michaela Docekalova
- Department of Research and Development, Prevention Medicals, Tovarni 342, 742 13 Studenka-Butovice, Czech Republic.
| | - Bozena Hosnedlova
- Department of Human Pharmacology and Toxicology, Faculty of Pharmacy, University of Veterinary and Pharmaceutical Sciences Brno, Palackeho 1946/1, 612 42 Brno, Czech Republic.
| | - Marta Kepinska
- Department of Biomedical and Environmental Analyses, Faculty of Pharmacy with Division of Laboratory Diagnostics, Wroclaw Medical University, Borowska 211, 50-556 Wroclaw, Poland.
| | - Branislav Ruttkay-Nedecky
- Department of Human Pharmacology and Toxicology, Faculty of Pharmacy, University of Veterinary and Pharmaceutical Sciences Brno, Palackeho 1946/1, 612 42 Brno, Czech Republic.
| | - Josef Ruzicka
- Department of Research and Development, Prevention Medicals, Tovarni 342, 742 13 Studenka-Butovice, Czech Republic.
| | - Carlos Fernandez
- School of Pharmacy and Life Sciences, Robert Gordon University, Garthdee Road, Aberdeen AB10 7QB, UK.
| | - Halina Milnerowicz
- Department of Biomedical and Environmental Analyses, Faculty of Pharmacy with Division of Laboratory Diagnostics, Wroclaw Medical University, Borowska 211, 50-556 Wroclaw, Poland.
| | - Rene Kizek
- Department of Research and Development, Prevention Medicals, Tovarni 342, 742 13 Studenka-Butovice, Czech Republic.
- Department of Human Pharmacology and Toxicology, Faculty of Pharmacy, University of Veterinary and Pharmaceutical Sciences Brno, Palackeho 1946/1, 612 42 Brno, Czech Republic.
- Department of Biomedical and Environmental Analyses, Faculty of Pharmacy with Division of Laboratory Diagnostics, Wroclaw Medical University, Borowska 211, 50-556 Wroclaw, Poland.
| |
Collapse
|
48
|
Riché R, Liao M, Pena IA, Leung KY, Lepage N, Greene NDE, Sarafoglou K, Schimmenti LA, Drapeau P, Samarut É. Glycine decarboxylase deficiency-induced motor dysfunction in zebrafish is rescued by counterbalancing glycine synaptic level. JCI Insight 2018; 3:124642. [PMID: 30385710 DOI: 10.1172/jci.insight.124642] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Accepted: 09/19/2018] [Indexed: 11/17/2022] Open
Abstract
Glycine encephalopathy (GE), or nonketotic hyperglycinemia (NKH), is a rare recessive genetic disease caused by defective glycine cleavage and characterized by increased accumulation of glycine in all tissues. Here, based on new case reports of GLDC loss-of-function mutations in GE patients, we aimed to generate a zebrafish model of severe GE in order to unravel the molecular mechanism of the disease. Using CRISPR/Cas9, we knocked out the gldc gene and showed that gldc-/- fish recapitulate GE on a molecular level and present a motor phenotype reminiscent of severe GE symptoms. The molecular characterization of gldc-/- mutants showed a broad metabolic disturbance affecting amino acids and neurotransmitters other than glycine, with lactic acidosis at stages preceding death. Although a transient imbalance was found in cell proliferation in the brain of gldc-/- zebrafish, the main brain networks were not affected, thus suggesting that GE pathogenicity is mainly due to metabolic defects. We confirmed that the gldc-/- hypotonic phenotype is due to NMDA and glycine receptor overactivation, and demonstrated that gldc-/- larvae depict exacerbated hyperglycinemia at these synapses. Remarkably, we were able to rescue the motor dysfunction of gldc-/- larvae by counterbalancing pharmacologically or genetically the level of glycine at the synapse.
Collapse
Affiliation(s)
- Raphaëlle Riché
- Research Center of the University of Montreal Hospital Center (CRCHUM), Department of Neurosciences, Université de Montréal, Montreal, Quebec, Canada
| | - Meijiang Liao
- Research Center of the University of Montreal Hospital Center (CRCHUM), Department of Neurosciences, Université de Montréal, Montreal, Quebec, Canada
| | - Izabella A Pena
- Children's Hospital of Eastern Ontario Research Institute and Department of Pediatrics, Faculty of Medicine, University of Ottawa, Ontario, Canada
| | - Kit-Yi Leung
- Developmental Biology and Cancer Programme, UCL Great Ormond Street Institute of Child Health, University College London, London, United Kingdom
| | - Nathalie Lepage
- Children's Hospital of Eastern Ontario Research Institute and Department of Pediatrics, Faculty of Medicine, University of Ottawa, Ontario, Canada
| | - Nicolas DE Greene
- Developmental Biology and Cancer Programme, UCL Great Ormond Street Institute of Child Health, University College London, London, United Kingdom
| | - Kyriakie Sarafoglou
- Division of Pediatric Endocrinology, Department of Pediatrics, University of Minnesota, Minneapolis, Minnesota, USA
| | - Lisa A Schimmenti
- Department of Otorhinolaryngology.,Department of Pediatrics, and.,Department of Clinical Genomics, Mayo Clinic College of Medicine, Rochester, Minnesota, USA
| | - Pierre Drapeau
- Research Center of the University of Montreal Hospital Center (CRCHUM), Department of Neurosciences, Université de Montréal, Montreal, Quebec, Canada.,DanioDesign Inc., Montréal, Quebec, Canada
| | - Éric Samarut
- Research Center of the University of Montreal Hospital Center (CRCHUM), Department of Neurosciences, Université de Montréal, Montreal, Quebec, Canada.,DanioDesign Inc., Montréal, Quebec, Canada
| |
Collapse
|
49
|
Walters RO, Arias E, Diaz A, Burgos ES, Guan F, Tiano S, Mao K, Green CL, Qiu Y, Shah H, Wang D, Hudgins AD, Tabrizian T, Tosti V, Shechter D, Fontana L, Kurland IJ, Barzilai N, Cuervo AM, Promislow DEL, Huffman DM. Sarcosine Is Uniquely Modulated by Aging and Dietary Restriction in Rodents and Humans. Cell Rep 2018; 25:663-676.e6. [PMID: 30332646 PMCID: PMC6280974 DOI: 10.1016/j.celrep.2018.09.065] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Revised: 08/02/2018] [Accepted: 09/19/2018] [Indexed: 02/06/2023] Open
Abstract
A hallmark of aging is a decline in metabolic homeostasis, which is attenuated by dietary restriction (DR). However, the interaction of aging and DR with the metabolome is not well understood. We report that DR is a stronger modulator of the rat metabolome than age in plasma and tissues. A comparative metabolomic screen in rodents and humans identified circulating sarcosine as being similarly reduced with aging and increased by DR, while sarcosine is also elevated in long-lived Ames dwarf mice. Pathway analysis in aged sarcosine-replete rats identify this biogenic amine as an integral node in the metabolome network. Finally, we show that sarcosine can activate autophagy in cultured cells and enhances autophagic flux in vivo, suggesting a potential role in autophagy induction by DR. Thus, these data identify circulating sarcosine as a biomarker of aging and DR in mammalians and may contribute to age-related alterations in the metabolome and in proteostasis.
Collapse
Affiliation(s)
- Ryan O Walters
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY, USA; Department of Medicine, Albert Einstein College of Medicine, Bronx, NY, USA; Institute for Aging Research, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Esperanza Arias
- Department of Medicine, Albert Einstein College of Medicine, Bronx, NY, USA; Institute for Aging Research, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Antonio Diaz
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, NY, USA; Institute for Aging Research, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Emmanuel S Burgos
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Fangxia Guan
- Department of Medicine, Albert Einstein College of Medicine, Bronx, NY, USA; Institute for Aging Research, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Simoni Tiano
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, NY, USA; Institute for Aging Research, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Kai Mao
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY, USA; Department of Medicine, Albert Einstein College of Medicine, Bronx, NY, USA; Institute for Aging Research, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Cara L Green
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, Scotland, UK
| | - Yungping Qiu
- Department of Medicine, Albert Einstein College of Medicine, Bronx, NY, USA; Einstein-Mount Sinai Diabetes Research Center, Stable Isotope and Metabolomics Core Facility, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Hardik Shah
- Department of Medicine, Albert Einstein College of Medicine, Bronx, NY, USA; Einstein-Mount Sinai Diabetes Research Center, Stable Isotope and Metabolomics Core Facility, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Donghai Wang
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY, USA; Institute for Aging Research, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Adam D Hudgins
- Department of Genetics, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Tahmineh Tabrizian
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY, USA; Institute for Aging Research, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Valeria Tosti
- Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - David Shechter
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Luigi Fontana
- Charles Perkins Centre, The University of Sydney, NSW 2006, Australia; Central Clinical School, The University of Sydney, NSW 2006, Australia; Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA; Department of Clinical and Experimental Sciences, Brescia University Medical School, Brescia, Italy
| | - Irwin J Kurland
- Department of Medicine, Albert Einstein College of Medicine, Bronx, NY, USA; Einstein-Mount Sinai Diabetes Research Center, Stable Isotope and Metabolomics Core Facility, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Nir Barzilai
- Department of Medicine, Albert Einstein College of Medicine, Bronx, NY, USA; Department of Genetics, Albert Einstein College of Medicine, Bronx, NY, USA; Institute for Aging Research, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Ana Maria Cuervo
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, NY, USA; Institute for Aging Research, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Daniel E L Promislow
- Department of Pathology, University of Washington, Seattle, WA, USA; Department of Biology, University of Washington, Seattle, WA, USA
| | - Derek M Huffman
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY, USA; Department of Medicine, Albert Einstein College of Medicine, Bronx, NY, USA; Institute for Aging Research, Albert Einstein College of Medicine, Bronx, NY, USA.
| |
Collapse
|
50
|
Strzelecki D, Urban-Kowalczyk M, Wysokiński A. Serum levels of TNF-alpha in patients with chronic schizophrenia during treatment augmentation with sarcosine (results of the PULSAR study). Psychiatry Res 2018; 268:447-453. [PMID: 30130712 DOI: 10.1016/j.psychres.2018.08.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Revised: 05/30/2018] [Accepted: 08/01/2018] [Indexed: 12/16/2022]
Abstract
Sarcosine, glycine transporter inhibitor, increases glycine levels around NMDA receptor, improving primary negative symptoms of schizophrenia. The aim of our study was to find a potential relationship between initial TNF-alpha level, its changes and schizophrenia symptoms severity, resulting from adding sarcosine to a stable antipsychotic treatment. Sixty subjects with stable schizophrenia were randomized to receive either 2 g of sarcosine or placebo and completed a 6-month, double blind, placebo-controlled study. Three patients on sarcosine and one taking placebo did not complete TNF-alpha tests, planned at the beginning, after 6 weeks and after 6 months. For clinical assessments we used PANSS and CDSS scales. No changes in TNF-alpha serum concentrations in both groups at any time-points was noted. The sarcosine group achieved significant improvement in negative symptoms, general psychopathology and total PANSS score group, however without any significant correlations between TNF-alpha levels and PANSS scores in all assessments. Positive correlations between TNF-alpha levels and CDSS score were found in the placebo group and total study group. Initial TNF-alpha concentrations cannot be used as a predictor of the improvement resulting from adding sarcosine. Sarcosine does not significantly affect TNF-alpha levels. TNF-alpha may be involved in mechanisms related to depressive symptomatology in schizophrenia.
Collapse
Affiliation(s)
- Dominik Strzelecki
- Department of Affective and Psychotic Disorders, Central Clinical Hospital, Medical University of Łódź, ul. Czechosłowacka 8/10, 92-216, Łódź, Poland.
| | - Małgorzata Urban-Kowalczyk
- Department of Affective and Psychotic Disorders, Central Clinical Hospital, Medical University of Łódź, ul. Czechosłowacka 8/10, 92-216, Łódź, Poland
| | - Adam Wysokiński
- Department of Old Age Psychiatry and Psychotic Disorders, Medical University of Łódź, Łódź, Poland
| |
Collapse
|