1
|
Couch ACM, Brown AM, Raimundo C, Solomon S, Taylor M, Sichlinger L, Matuleviciute R, Srivastava DP, Vernon AC. Transcriptional and cellular response of hiPSC-derived microglia-neural progenitor co-cultures exposed to IL-6. Brain Behav Immun 2024:S0889-1591(24)00529-4. [PMID: 39098436 DOI: 10.1016/j.bbi.2024.08.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/11/2024] [Revised: 07/12/2024] [Accepted: 08/01/2024] [Indexed: 08/06/2024] Open
Abstract
Elevated interleukin (IL-)6 levels during prenatal development have been linked to increased risk for neurodevelopmental disorders (NDD) in the offspring, but the mechanism remains unclear. Human-induced pluripotent stem cell (hiPSC) models offer a valuable tool to study the effects of IL-6 on features relevant for human neurodevelopment in vitro. We previously reported that hiPSC-derived microglia-like cells (MGLs) respond to IL-6, but neural progenitor cells (NPCs) in monoculture do not. Therefore, we investigated whether co-culturing hiPSC-derived MGLs with NPCs would trigger a cellular response to IL-6 stimulation via secreted factors from the MGLs. Using N=4 donor lines without psychiatric diagnosis, we first confirmed that NPCs can respond to IL-6 through trans-signalling when recombinant IL-6Ra is present, and that this response is dose-dependent. MGLs secreted soluble IL-6R, but at lower levels than found in vivo and below that needed to activate trans-signalling in NPCs. Whilst transcriptomic and secretome analysis confirmed that MGLs undergo substantial transcriptomic changes after IL-6 exposure and subsequently secrete a cytokine milieu, NPCs in co-culture with MGLs exhibited a minimal transcriptional response. Furthermore, there were no significant cell fate-acquisition changes when differentiated into post-mitotic cultures, nor alterations in synaptic densities in mature neurons. These findings highlight the need to investigate if trans-IL-6 signalling to NPCs is a relevant disease mechanism linking prenatal IL-6 exposure to increased risk for psychiatric disorders. Moreover, our findings underscore the importance of establishing more complex in vitro human models with diverse cell types, which may show cell-specific responses to microglia-released cytokines to fully understand how IL-6 exposure may influence human neurodevelopment.
Collapse
Affiliation(s)
- Amalie C M Couch
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK; MRC Centre for Neurodevelopmental Disorders, King's College London, London, UK.
| | - Amelia M Brown
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK; MRC Centre for Neurodevelopmental Disorders, King's College London, London, UK
| | - Catarina Raimundo
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK; Faculty of Life Sciences and Medicine, King's College London, London, UK
| | - Shiden Solomon
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Morgan Taylor
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Laura Sichlinger
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK; MRC Centre for Neurodevelopmental Disorders, King's College London, London, UK
| | - Rugile Matuleviciute
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK; MRC Centre for Neurodevelopmental Disorders, King's College London, London, UK
| | - Deepak P Srivastava
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK; MRC Centre for Neurodevelopmental Disorders, King's College London, London, UK
| | - Anthony C Vernon
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK; MRC Centre for Neurodevelopmental Disorders, King's College London, London, UK.
| |
Collapse
|
2
|
Schoonover KE, Miller NE, Fish KN, Lewis DA. Scaling of smaller pyramidal neuron size and lower energy production in schizophrenia. Neurobiol Dis 2024; 191:106394. [PMID: 38176569 PMCID: PMC10898364 DOI: 10.1016/j.nbd.2023.106394] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Revised: 12/21/2023] [Accepted: 12/21/2023] [Indexed: 01/06/2024] Open
Abstract
BACKGROUND Dorsolateral prefrontal cortex (DLPFC) dysfunction in schizophrenia appears to reflect alterations in layer 3 pyramidal neurons (L3PNs), including smaller cell bodies and lower expression of mitochondrial energy production genes. However, prior somal size studies used biased strategies for identifying L3PNs, and somal size and levels of energy production markers have not been assessed in individual L3PNs. STUDY DESIGN We combined fluorescent in situ hybridization (FISH) of vesicular glutamate transporter 1 (VGLUT1) mRNA and immunohistochemical-labeling of NeuN to determine if the cytoplasmic distribution of VGLUT1 mRNA permits the unbiased identification and somal size quantification of L3PNs. Dual-label FISH for VGLUT1 mRNA and cytochrome C oxidase subunit 4I1 (COX4I1) mRNA, a marker of energy production, was used to assess somal size and COX4I1 transcript levels in individual DLPFC L3PNs from schizophrenia (12 males; 2 females) and unaffected comparison (13 males; 1 female) subjects. STUDY RESULTS Measures of L3PN somal size with NeuN immunohistochemistry or VGLUT1 mRNA provided nearly identical results (ICC = 0.96, p < 0.0001). Mean somal size of VGLUT1-identified L3PNs was 8.7% smaller (p = 0.004) and mean COX4I1 mRNA levels per L3PN were 16.7% lower (p = 0.01) in schizophrenia. These measures were correlated across individual L3PNs in both subject groups (rrm = 0.81-0.86). CONCLUSIONS This preliminary study presents a novel method for combining unbiased neuronal identification with quantitative assessments of somal size and mRNA levels. We replicated findings of smaller somal size and lower COX4I1 mRNA levels in DLPFC L3PNs in schizophrenia. The normal scaling of COX4I1 mRNA levels with somal size in schizophrenia suggests that lower markers of energy production are secondary to L3PN morphological alterations in the illness.
Collapse
Affiliation(s)
- Kirsten E Schoonover
- Translational Neuroscience Program, Department of Psychiatry, School of Medicine, University of Pittsburgh, Department of Psychiatry Biomedical Science Tower, W1653 3811 O'Hara Street Pittsburgh, PA 15213, United States of America
| | - Nora E Miller
- Department of Neuroscience, Dietrich School of Arts and Sciences, University of Pittsburgh, Department of Psychiatry, Biomedical Science Tower W1653 3811 O'Hara Street Pittsburgh, PA 15213, United States of America
| | - Kenneth N Fish
- Translational Neuroscience Program, Department of Psychiatry, School of Medicine, University of Pittsburgh, Department of Psychiatry Biomedical Science Tower, W1653 3811 O'Hara Street Pittsburgh, PA 15213, United States of America
| | - David A Lewis
- Translational Neuroscience Program, Department of Psychiatry, School of Medicine, University of Pittsburgh, Department of Psychiatry Biomedical Science Tower, W1653 3811 O'Hara Street Pittsburgh, PA 15213, United States of America.
| |
Collapse
|
3
|
Abstract
Rett syndrome is a neurodevelopmental disorder caused by loss-of-function mutations in the methyl-CpG binding protein-2 (MeCP2) gene that is characterized by epilepsy, intellectual disability, autistic features, speech deficits, and sleep and breathing abnormalities. Neurologically, patients with all three disorders display microcephaly, aberrant dendritic morphology, reduced spine density, and an imbalance of excitatory/inhibitory signaling. Loss-of-function mutations in the cyclin-dependent kinase-like 5 (CDKL5) and FOXG1 genes also cause similar behavioral and neurobiological defects and were referred to as congenital or variant Rett syndrome. The relatively recent realization that CDKL5 deficiency disorder (CDD), FOXG1 syndrome, and Rett syndrome are distinct neurodevelopmental disorders with some distinctive features have resulted in separate focus being placed on each disorder with the assumption that distinct molecular mechanisms underlie their pathogenesis. However, given that many of the core symptoms and neurological features are shared, it is likely that the disorders share some critical molecular underpinnings. This review discusses the possibility that deregulation of common molecules in neurons and astrocytes plays a central role in key behavioral and neurological abnormalities in all three disorders. These include KCC2, a chloride transporter, vGlut1, a vesicular glutamate transporter, GluD1, an orphan-glutamate receptor subunit, and PSD-95, a postsynaptic scaffolding protein. We propose that reduced expression or activity of KCC2, vGlut1, PSD-95, and AKT, along with increased expression of GluD1, is involved in the excitatory/inhibitory that represents a key aspect in all three disorders. In addition, astrocyte-derived brain-derived neurotrophic factor (BDNF), insulin-like growth factor 1 (IGF-1), and inflammatory cytokines likely affect the expression and functioning of these molecules resulting in disease-associated abnormalities.
Collapse
Affiliation(s)
- Santosh R D’Mello
- Department of Biological Sciences, Louisiana State University Shreveport, Shreveport, LA 71104, USA
| |
Collapse
|
4
|
Derome M, Kozuharova P, Diaconescu AO, Denève S, Jardri R, Allen P. Functional connectivity and glutamate levels of the medial prefrontal cortex in schizotypy are related to sensory amplification in a probabilistic reasoning task. Neuroimage 2023; 278:120280. [PMID: 37460012 DOI: 10.1016/j.neuroimage.2023.120280] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Revised: 07/04/2023] [Accepted: 07/13/2023] [Indexed: 07/27/2023] Open
Abstract
The circular inference (CI) computational model assumes a corruption of sensory data by prior information and vice versa, leading at the extremes to 'see what we expect' (through prior amplification) and/or to 'expect what we see' (through sensory amplification). Although a CI mechanism has been reported in a schizophrenia population, it has not been investigated in individuals experiencing psychosis-like experiences, such as people with high schizotypy traits. Furthermore, the neurobiological basis of CI, such as the link between hierarchical amplifications, excitatory neurotransmission, and resting state functional connectivity (RSFC), remains untested. The participants included in the present study consisted of a subsample of those recruited in a study previously published by our group, Kozhuharova et al. (2021b). We included 36 participants with High (n=18) and Low (n=18) levels of schizotypy who completed a probabilistic reasoning task (the Fisher task) for which individual confidence levels were obtained and fitted to the CI model. Participants also underwent a 1H-Magnetic Resonance Spectroscopy (MRS) scan to measure medial prefrontal cortex (mPFC) glutamate metabolite levels, and a functional Magnetic Resonance Imaging (fMRI) scan to measure RSFC of the medial prefrontal cortex (mPFC). People with high levels of schizotypy exhibited changes in CI parameters, altered cortical excitatory neurotransmission and RSFC that were all associated with sensory amplification. Our findings capture a multimodal signature of CI that is observable in people early in the psychosis spectrum.
Collapse
Affiliation(s)
- Mélodie Derome
- School of Psychology, University of Roehampton, Whitelands College, Hollybourne Avenue, London SW154JD, UK; Lille Neuroscience & Cognition Centre (LiNC), Plasticity & Subjectivity Team, Univ Lille, INSERM U-1172, CHU Lille, FR 59037, France; Combined Universities Brain Imaging Centre, Royal Holloway University, London TW200EX, UK
| | - Petya Kozuharova
- School of Psychology, University of Roehampton, Whitelands College, Hollybourne Avenue, London SW154JD, UK
| | - Andreea O Diaconescu
- Department of Psychiatry, Brain and Therapeutics, Krembil Centre for Neuroinformatics, CAMH, Toronto M5S2S1, Canada; Department of Psychiatry, University of Toronto, Toronto, ON MS5, Canada
| | - Sophie Denève
- Laboratoire de Neurosciences Cognitives et Computationnelles (LNC²), ENS, INSERM U-960, PSL Research University, Paris, FR 75006, France
| | - Renaud Jardri
- School of Psychology, University of Roehampton, Whitelands College, Hollybourne Avenue, London SW154JD, UK; Laboratoire de Neurosciences Cognitives et Computationnelles (LNC²), ENS, INSERM U-960, PSL Research University, Paris, FR 75006, France.
| | - Paul Allen
- School of Psychology, University of Roehampton, Whitelands College, Hollybourne Avenue, London SW154JD, UK; Combined Universities Brain Imaging Centre, Royal Holloway University, London TW200EX, UK; Department of Neuroimaging, Institute of Psychiatry, Psychology & Neuroscience, King's College London, SE58AF, UK.
| |
Collapse
|
5
|
Tipton AE, Del Angel YC, Hixson K, Carlsen J, Strode D, Busquet N, Mesches MH, Gonzalez MI, Napoli E, Russek SJ, Brooks-Kayal AR. Selective Neuronal Knockout of STAT3 Function Inhibits Epilepsy Progression, Improves Cognition, and Restores Dysregulated Gene Networks in a Temporal Lobe Epilepsy Model. Ann Neurol 2023; 94:106-122. [PMID: 36935347 PMCID: PMC10313781 DOI: 10.1002/ana.26644] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Revised: 03/14/2023] [Accepted: 03/16/2023] [Indexed: 03/21/2023]
Abstract
OBJECTIVE Temporal lobe epilepsy (TLE) is a progressive disorder mediated by pathological changes in molecular cascades and hippocampal neural circuit remodeling that results in spontaneous seizures and cognitive dysfunction. Targeting these cascades may provide disease-modifying treatments for TLE patients. Janus Kinase/Signal Transducer and Activator of Transcription (JAK/STAT) inhibitors have emerged as potential disease-modifying therapies; a more detailed understanding of JAK/STAT participation in epileptogenic responses is required, however, to increase the therapeutic efficacy and reduce adverse effects associated with global inhibition. METHODS We developed a mouse line in which tamoxifen treatment conditionally abolishes STAT3 signaling from forebrain excitatory neurons (nSTAT3KO). Seizure frequency (continuous in vivo electroencephalography) and memory (contextual fear conditioning and motor learning) were analyzed in wild-type and nSTAT3KO mice after intrahippocampal kainate (IHKA) injection as a model of TLE. Hippocampal RNA was obtained 24 h after IHKA and subjected to deep sequencing. RESULTS Selective STAT3 knock-out in excitatory neurons reduced seizure progression and hippocampal memory deficits without reducing the extent of cell death or mossy fiber sprouting induced by IHKA injection. Gene expression was rescued in major networks associated with response to brain injury, neuronal plasticity, and learning and memory. We also provide the first evidence that neuronal STAT3 may directly influence brain inflammation. INTERPRETATION Inhibiting neuronal STAT3 signaling improved outcomes in an animal model of TLE, prevented progression of seizures and cognitive co-morbidities while rescuing pathogenic changes in gene expression of major networks associated with epileptogenesis. Specifically targeting neuronal STAT3 may be an effective disease-modifying strategy for TLE. ANN NEUROL 2023;94:106-122.
Collapse
Affiliation(s)
- Allison E. Tipton
- Graduate Program for Neuroscience, Center for Systems Neuroscience, Boston University, Boston, MA, USA
| | - Yasmin Cruz Del Angel
- Department of Neurology, University of California Davis School of Medicine, Sacramento, CA, USA
| | - Kathryn Hixson
- Graduate Program for Neuroscience, Center for Systems Neuroscience, Boston University, Boston, MA, USA
| | - Jessica Carlsen
- Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO, USA
| | - Dana Strode
- Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO, USA
| | - Nicolas Busquet
- Department of Neurology, University of Colorado School of Medicine, Aurora, CO, USA
| | - Michael H. Mesches
- Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO, USA
| | - Marco I. Gonzalez
- Department of Neurology, University of California Davis School of Medicine, Sacramento, CA, USA
| | - Eleonora Napoli
- Department of Neurology, University of California Davis School of Medicine, Sacramento, CA, USA
| | - Shelley J. Russek
- Graduate Program for Neuroscience, Center for Systems Neuroscience, Boston University, Boston, MA, USA
- Department of Pharmacology and Experimental Therapeutics, Boston University School of Medicine, Boston, MA, USA
| | - Amy R. Brooks-Kayal
- Department of Neurology, University of California Davis School of Medicine, Sacramento, CA, USA
| |
Collapse
|
6
|
de Bartolomeis A, Ciccarelli M, De Simone G, Mazza B, Barone A, Vellucci L. Canonical and Non-Canonical Antipsychotics' Dopamine-Related Mechanisms of Present and Next Generation Molecules: A Systematic Review on Translational Highlights for Treatment Response and Treatment-Resistant Schizophrenia. Int J Mol Sci 2023; 24:ijms24065945. [PMID: 36983018 PMCID: PMC10051989 DOI: 10.3390/ijms24065945] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 03/15/2023] [Accepted: 03/17/2023] [Indexed: 03/30/2023] Open
Abstract
Schizophrenia is a severe psychiatric illness affecting almost 25 million people worldwide and is conceptualized as a disorder of synaptic plasticity and brain connectivity. Antipsychotics are the primary pharmacological treatment after more than sixty years after their introduction in therapy. Two findings hold true for all presently available antipsychotics. First, all antipsychotics occupy the dopamine D2 receptor (D2R) as an antagonist or partial agonist, even if with different affinity; second, D2R occupancy is the necessary and probably the sufficient mechanism for antipsychotic effect despite the complexity of antipsychotics' receptor profile. D2R occupancy is followed by coincident or divergent intracellular mechanisms, implying the contribution of cAMP regulation, β-arrestin recruitment, and phospholipase A activation, to quote some of the mechanisms considered canonical. However, in recent years, novel mechanisms related to dopamine function beyond or together with D2R occupancy have emerged. Among these potentially non-canonical mechanisms, the role of Na2+ channels at the dopamine at the presynaptic site, dopamine transporter (DAT) involvement as the main regulator of dopamine concentration at synaptic clefts, and the putative role of antipsychotics as chaperones for intracellular D2R sequestration, should be included. These mechanisms expand the fundamental role of dopamine in schizophrenia therapy and may have relevance to considering putatively new strategies for treatment-resistant schizophrenia (TRS), an extremely severe condition epidemiologically relevant and affecting almost 30% of schizophrenia patients. Here, we performed a critical evaluation of the role of antipsychotics in synaptic plasticity, focusing on their canonical and non-canonical mechanisms of action relevant to the treatment of schizophrenia and their subsequent implication for the pathophysiology and potential therapy of TRS.
Collapse
Affiliation(s)
- Andrea de Bartolomeis
- Section of Psychiatry, Laboratory of Translational and Molecular Psychiatry and Unit of Treatment-Resistant Psychosis, Department of Neuroscience, Reproductive Sciences and Dentistry, University Medical School of Naples "Federico II", 80131 Naples, Italy
| | - Mariateresa Ciccarelli
- Section of Psychiatry, Laboratory of Translational and Molecular Psychiatry and Unit of Treatment-Resistant Psychosis, Department of Neuroscience, Reproductive Sciences and Dentistry, University Medical School of Naples "Federico II", 80131 Naples, Italy
| | - Giuseppe De Simone
- Section of Psychiatry, Laboratory of Translational and Molecular Psychiatry and Unit of Treatment-Resistant Psychosis, Department of Neuroscience, Reproductive Sciences and Dentistry, University Medical School of Naples "Federico II", 80131 Naples, Italy
| | - Benedetta Mazza
- Section of Psychiatry, Laboratory of Translational and Molecular Psychiatry and Unit of Treatment-Resistant Psychosis, Department of Neuroscience, Reproductive Sciences and Dentistry, University Medical School of Naples "Federico II", 80131 Naples, Italy
| | - Annarita Barone
- Section of Psychiatry, Laboratory of Translational and Molecular Psychiatry and Unit of Treatment-Resistant Psychosis, Department of Neuroscience, Reproductive Sciences and Dentistry, University Medical School of Naples "Federico II", 80131 Naples, Italy
| | - Licia Vellucci
- Section of Psychiatry, Laboratory of Translational and Molecular Psychiatry and Unit of Treatment-Resistant Psychosis, Department of Neuroscience, Reproductive Sciences and Dentistry, University Medical School of Naples "Federico II", 80131 Naples, Italy
| |
Collapse
|
7
|
Roberts RC, McCollum LA, Schoonover KE, Mabry SJ, Roche JK, Lahti AC. Ultrastructural evidence for glutamatergic dysregulation in schizophrenia. Schizophr Res 2022; 249:4-15. [PMID: 32014360 PMCID: PMC7392793 DOI: 10.1016/j.schres.2020.01.016] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Revised: 01/16/2020] [Accepted: 01/18/2020] [Indexed: 12/14/2022]
Abstract
The aim of this paper is to summarize ultrastructural evidence for glutamatergic dysregulation in several linked regions in postmortem schizophrenia brain. Following a brief summary of glutamate circuitry and how synapses are identified at the electron microscopic (EM) level, we will review EM pathology in the cortex and basal ganglia. We will include the effects of antipsychotic drugs and the relation of treatment response. We will discuss how these findings support or confirm other postmortem findings as well as imaging results. Briefly, synaptic and mitochondrial density in anterior cingulate cortex was decreased in schizophrenia, versus normal controls (NCs), in a selective layer specific pattern. In dorsal striatum, increases in excitatory synaptic density were detected in caudate matrix, a compartment associated with cognitive and motor function, and in the putamen patches, a region associated with limbic function and in the core of the nucleus accumbens. Patients who were treatment resistant or untreated had significantly elevated numbers of excitatory synapses in limbic striatal areas in comparison to NCs and responders. Protein levels of vGLUT2, found in subcortical glutamatergic neurons, were increased in the nucleus accumbens in schizophrenia. At the EM level, schizophrenia subjects had an increase in density of excitatory synapses in several areas of the basal ganglia. In the substantia nigra, the protein levels of vGLUT2 were elevated in untreated patients compared to NCs. The density of inhibitory synapses was decreased in schizophrenia versus NCs. In schizophrenia, glutamatergic synapses are differentially affected depending on the brain region, treatment status, and treatment response.
Collapse
Affiliation(s)
- Rosalinda C Roberts
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama, Birmingham, AL 35294, United States of America.
| | - Lesley A McCollum
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama, Birmingham, AL 35294, United States of America
| | - Kirsten E Schoonover
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama, Birmingham, AL 35294, United States of America
| | - Samuel J Mabry
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama, Birmingham, AL 35294, United States of America
| | - Joy K Roche
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama, Birmingham, AL 35294, United States of America
| | - Adrienne C Lahti
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama, Birmingham, AL 35294, United States of America
| |
Collapse
|
8
|
Relevance of interactions between dopamine and glutamate neurotransmission in schizophrenia. Mol Psychiatry 2022; 27:3583-3591. [PMID: 35681081 PMCID: PMC9712151 DOI: 10.1038/s41380-022-01649-w] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Revised: 05/16/2022] [Accepted: 05/25/2022] [Indexed: 02/08/2023]
Abstract
Dopamine (DA) and glutamate neurotransmission are strongly implicated in schizophrenia pathophysiology. While most studies focus on contributions of neurons that release only DA or glutamate, neither DA nor glutamate models alone recapitulate the full spectrum of schizophrenia pathophysiology. Similarly, therapeutic strategies limited to either system cannot effectively treat all three major symptom domains of schizophrenia: positive, negative, and cognitive symptoms. Increasing evidence suggests extensive interactions between the DA and glutamate systems and more effective treatments may therefore require the targeting of both DA and glutamate signaling. This offers the possibility that disrupting DA-glutamate circuitry between these two systems, particularly in the striatum and forebrain, culminate in schizophrenia pathophysiology. Yet, the mechanisms behind these interactions and their contributions to schizophrenia remain unclear. In addition to circuit- or system-level interactions between neurons that solely release either DA or glutamate, here we posit that functional alterations involving a subpopulation of neurons that co-release both DA and glutamate provide a novel point of integration between DA and glutamate systems, offering a key missing link in our understanding of schizophrenia pathophysiology. Better understanding of mechanisms underlying DA/glutamate co-release from these neurons may therefore shed new light on schizophrenia pathophysiology and lead to more effective therapeutics.
Collapse
|
9
|
Bauminger H, Gaisler-Salomon I. Beyond NMDA Receptors: Homeostasis at the Glutamate Tripartite Synapse and Its Contributions to Cognitive Dysfunction in Schizophrenia. Int J Mol Sci 2022; 23:8617. [PMID: 35955750 PMCID: PMC9368772 DOI: 10.3390/ijms23158617] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Revised: 07/30/2022] [Accepted: 08/01/2022] [Indexed: 02/01/2023] Open
Abstract
Cognitive deficits are core symptoms of schizophrenia but remain poorly addressed by dopamine-based antipsychotic medications. Glutamate abnormalities are implicated in schizophrenia-related cognitive deficits. While the role of the NMDA receptor has been extensively studied, less attention was given to other components that control glutamate homeostasis. Glutamate dynamics at the tripartite synapse include presynaptic and postsynaptic components and are tightly regulated by neuron-astrocyte crosstalk. Here, we delineate the role of glutamate homeostasis at the tripartite synapse in schizophrenia-related cognitive dysfunction. We focus on cognitive domains that can be readily measured in humans and rodents, i.e., working memory, recognition memory, cognitive flexibility, and response inhibition. We describe tasks used to measure cognitive function in these domains in humans and rodents, and the relevance of glutamate alterations in these domains. Next, we delve into glutamate tripartite synaptic components and summarize findings that implicate the relevance of these components to specific cognitive domains. These collective findings indicate that neuron-astrocyte crosstalk at the tripartite synapse is essential for cognition, and that pre- and postsynaptic components play a critical role in maintaining glutamate homeostasis and cognitive well-being. The contribution of these components to cognitive function should be considered in order to better understand the role played by glutamate signaling in cognition and develop efficient pharmacological treatment avenues for schizophrenia treatment-resistant symptoms.
Collapse
Affiliation(s)
- Hagar Bauminger
- School of Psychological Sciences, Department of Psychology, University of Haifa, Haifa 3498838, Israel;
- The Integrated Brain and Behavior Research Center (IBBRC), University of Haifa, Haifa 3498838, Israel
| | - Inna Gaisler-Salomon
- School of Psychological Sciences, Department of Psychology, University of Haifa, Haifa 3498838, Israel;
- The Integrated Brain and Behavior Research Center (IBBRC), University of Haifa, Haifa 3498838, Israel
| |
Collapse
|
10
|
Rostamipour K, Talandashti R, Mehrnejad F. Atomistic insight into the luminal allosteric regulation of vesicular glutamate transporter 2 by chloride and protons: An
all‐atom
molecular dynamics simulation study. Proteins 2022; 90:2045-2057. [DOI: 10.1002/prot.26396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Revised: 05/27/2022] [Accepted: 06/28/2022] [Indexed: 11/08/2022]
Affiliation(s)
- Kiana Rostamipour
- Department of Life Sciences Engineering, Faculty of New Sciences and Technologies University of Tehran Tehran Iran
| | - Reza Talandashti
- Department of Life Sciences Engineering, Faculty of New Sciences and Technologies University of Tehran Tehran Iran
| | - Faramarz Mehrnejad
- Department of Life Sciences Engineering, Faculty of New Sciences and Technologies University of Tehran Tehran Iran
| |
Collapse
|
11
|
Wu X, Shukla R, Alganem K, Zhang X, Eby HM, Devine EA, Depasquale E, Reigle J, Simmons M, Hahn MK, Au-Yeung C, Asgariroozbehani R, Hahn CG, Haroutunian V, Meller J, Meador-Woodruff J, McCullumsmith RE. Transcriptional profile of pyramidal neurons in chronic schizophrenia reveals lamina-specific dysfunction of neuronal immunity. Mol Psychiatry 2021; 26:7699-7708. [PMID: 34272489 PMCID: PMC8761210 DOI: 10.1038/s41380-021-01205-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 06/03/2021] [Accepted: 06/18/2021] [Indexed: 02/06/2023]
Abstract
While the pathophysiology of schizophrenia has been extensively investigated using homogenized postmortem brain samples, few studies have examined changes in brain samples with techniques that may attribute perturbations to specific cell types. To fill this gap, we performed microarray assays on mRNA isolated from anterior cingulate cortex (ACC) superficial and deep pyramidal neurons from 12 schizophrenia and 12 control subjects using laser-capture microdissection. Among all the annotated genes, we identified 134 significantly increased and 130 decreased genes in superficial pyramidal neurons, while 93 significantly increased and 101 decreased genes were found in deep pyramidal neurons, in schizophrenia compared to control subjects. In these differentially expressed genes, we detected lamina-specific changes of 55 and 31 genes in superficial and deep neurons in schizophrenia, respectively. Gene set enrichment analysis (GSEA) was applied to the entire pre-ranked differential expression gene lists to gain a complete pathway analysis throughout all annotated genes. Our analysis revealed overrepresented groups of gene sets in schizophrenia, particularly in immunity and synapse-related pathways, suggesting the disruption of these pathways plays an important role in schizophrenia. We also detected other pathways previously demonstrated in schizophrenia pathophysiology, including cytokine and chemotaxis, postsynaptic signaling, and glutamatergic synapses. In addition, we observed several novel pathways, including ubiquitin-independent protein catabolic process. Considering the effects of antipsychotic treatment on gene expression, we applied a novel bioinformatics approach to compare our differential expression gene profiles with 51 antipsychotic treatment datasets, demonstrating that our results were not influenced by antipsychotic treatment. Taken together, we found pyramidal neuron-specific changes in neuronal immunity, synaptic dysfunction, and olfactory dysregulation in schizophrenia, providing new insights for the cell-subtype specific pathophysiology of chronic schizophrenia.
Collapse
Affiliation(s)
- Xiaojun Wu
- Department of Neurosciences, University of Toledo College of Medicine, Toledo, OH, USA
| | - Rammohan Shukla
- Department of Neurosciences, University of Toledo College of Medicine, Toledo, OH, USA
| | - Khaled Alganem
- Department of Neurosciences, University of Toledo College of Medicine, Toledo, OH, USA
| | - Xiaolu Zhang
- Department of Neurosciences, University of Toledo College of Medicine, Toledo, OH, USA
| | - Hunter M. Eby
- Department of Neurosciences, University of Toledo College of Medicine, Toledo, OH, USA
| | - Emily A. Devine
- Department of Neurosciences, University of Toledo College of Medicine, Toledo, OH, USA
| | - Erica Depasquale
- Department of Biomedical Informatics, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH, USA
| | - James Reigle
- Department of Biomedical Informatics, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH, USA
| | - Micah Simmons
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham School of Medicine, Birmingham, AL, USA
| | - Margaret K. Hahn
- Centre for Addiction and Mental Health, 250 College Street, Toronto, Ontario, Canada, M5T 1R8,Institute of Medical Sciences, University of Toronto, 1 King’s College Circle, Toronto, Ontario, Canada, M5S 1A8
| | - Christy Au-Yeung
- Centre for Addiction and Mental Health, 250 College Street, Toronto, Ontario, Canada, M5T 1R8
| | - Roshanak Asgariroozbehani
- Centre for Addiction and Mental Health, 250 College Street, Toronto, Ontario, Canada, M5T 1R8,Institute of Medical Sciences, University of Toronto, 1 King’s College Circle, Toronto, Ontario, Canada, M5S 1A8
| | - Chang-Gyu Hahn
- Department of Psychiatry, Vickie & Jack Farber Institute for Neuroscience, Jefferson University Hospitals, Philadelphia, PA, USA
| | - Vahram Haroutunian
- Departments of Psychiatry and Neuroscience, The Icahn School of Medicine at Mount Sinai, NY, USA,James J. Peters VA Medical Center, Mental Illness Research Education and Clinical Center (MIRECC), Bronx, NY, USA
| | - Jarek Meller
- Department of Biomedical Informatics, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH, USA
| | - James Meador-Woodruff
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham School of Medicine, Birmingham, AL, USA
| | - Robert E. McCullumsmith
- Department of Neurosciences, University of Toledo College of Medicine, Toledo, OH, USA,Neurosciences Institute, ProMedica, Toledo, OH, USA,Author for correspondence: Robert E. McCullumsmith, M.D., Ph.D., Department of Neurosciences, University of Toledo College of Medicine, 3000 Arlington Avenue, Block Health Science Building, Mail Stop 1007, Toledo, OH 43614,
| |
Collapse
|
12
|
Smucny J, Carter CS, Maddock RJ. Medial Prefrontal Cortex Glutamate Is Reduced in Schizophrenia and Moderated by Measurement Quality: A Meta-analysis of Proton Magnetic Resonance Spectroscopy Studies. Biol Psychiatry 2021; 90:643-651. [PMID: 34344534 PMCID: PMC9303057 DOI: 10.1016/j.biopsych.2021.06.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 06/01/2021] [Accepted: 06/06/2021] [Indexed: 02/08/2023]
Abstract
BACKGROUND Magnetic resonance spectroscopy studies measuring brain glutamate separately from glutamine are helping elucidate schizophrenia pathophysiology. An expanded literature and improved methodologies motivate an updated meta-analysis examining effects of measurement quality and other moderating factors in characterizing abnormal glutamate levels in schizophrenia. METHODS Searching previous meta-analyses and the MEDLINE database identified 83 proton magnetic resonance spectroscopy datasets published through March 25, 2020. Three quality metrics were extracted-Cramér-Rao lower bound (CRLB), line width, and coefficient of variation. Pooled effect sizes (Hedges' g) were calculated with random-effects, inverse variance-weighted models. Moderator analyses were conducted using quality metrics, field strength, echo time, medication, age, and stage of illness. RESULTS Across 36 datasets (2086 participants), medial prefrontal cortex glutamate was significantly reduced in patients (g = -0.19, confidence interval [CI] = -0.07 to -0.32). CRLB and coefficient of variation quality subgroups significantly moderated this effect. Glutamate was significantly more reduced in studies with lower CRLB or coefficient of variation (g = -0.44, CI = -0.29 to -0.60, and g = -0.43, CI = -0.29 to -0.57, respectively). Studies using echo time ≤20 ms also showed significantly greater reduction in glutamate (g = -0.41, CI = -0.26 to -0.55). Across 11 hippocampal datasets, group differences and moderator effects were nonsignificant. Group effects in thalamus and dorsolateral prefrontal cortex were also nonsignificant. CONCLUSIONS High-quality measurements reveal consistently reduced medial prefrontal cortex glutamate in schizophrenia. Stricter CRLB criteria and reduced nuisance variance may increase the sensitivity of future studies examining additional regions and the pathophysiological significance of abnormal glutamate levels in schizophrenia.
Collapse
Affiliation(s)
- Jason Smucny
- Department of Psychiatry and Behavioral Sciences, University of California Davis, Davis, California
| | - Cameron S Carter
- Department of Psychiatry and Behavioral Sciences, University of California Davis, Davis, California
| | - Richard J Maddock
- Department of Psychiatry and Behavioral Sciences, University of California Davis, Davis, California.
| |
Collapse
|
13
|
Ayala-Lopez N, Watts SW. Physiology and Pharmacology of Neurotransmitter Transporters. Compr Physiol 2021; 11:2279-2295. [PMID: 34190339 DOI: 10.1002/cphy.c200035] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Regulation of the ability of a neurotransmitter [our focus: serotonin, norepinephrine, dopamine, acetylcholine, glycine, and gamma-aminobutyric acid (GABA)] to reach its receptor targets is regulated in part by controlling the access the neurotransmitter has to receptors. Transporters, located at both the cellular plasma membrane and in subcellular vesicles, carry a myriad of responsibilities that include enabling neurotransmitter release and controlling uptake of neurotransmitter back into a cell or vesicle. Driven largely by electrochemical gradients, these transporters move neurotransmitters. The regulation of the transporters themselves through changes in expression and/or posttranslational modification allows for fine-tuning of this system. Transporters have been best recognized as targets for psychoactive stimulants and remain a mainstay target of primarily central nervous system (CNS) acting drugs for treatment of debilitating diseases such as depression and anxiety. Studies reveal, however, that transporters are found and functional in tissues outside the CNS (gastrointestinal and cardiovascular tissues, for example). The importance of neurotransmitter transporters is underscored with discoveries that dysfunction of transporters can cause life-changing disease. This article provides a high-level review of major classes of both plasma membrane transporters and vesicular transporters. © 2021 American Physiological Society. Compr Physiol 11:2279-2295, 2021.
Collapse
Affiliation(s)
- Nadia Ayala-Lopez
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Stephanie W Watts
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, Michigan, USA
| |
Collapse
|
14
|
Zhou JW, Zhao M, Rang WL, Zhang XY, Liu ZM, Zhang LR, Wang TX, Wu CT, Cheng XR, Zhou WX. Proteome Profiling Identified Amyloid-β Protein Precursor as a Novel Binding Partner and Modulator of VGLUT1. J Alzheimers Dis 2021; 81:981-1038. [PMID: 33896843 DOI: 10.3233/jad-210117] [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: 11/15/2022]
Abstract
BACKGROUND The toxicity of excessive glutamate release has been implicated in various acute and chronic neurodegenerative conditions. Vesicular glutamate transporters (VGLUTs) are the major mediators for the uptake of glutamate into synaptic vesicles. However, the dynamics and mechanism of this process in glutamatergic neurons are still largely unknown. OBJECTIVE This study aimed to investigate the candidate protein partners of VGLUT1 and their regulatory roles in the vesicles in rat brain. METHODS Pull down assay, co-immunoprecipitation assay, or split-ubiquitin membrane yeast two hybrid screening coupled with nanoRPLC-MS/MS were used to identify the candidate protein partners of VGLUT1 in the vesicles in rat brain. The in vitro and in vivo models were used to test effects of AβPP, Atp6ap2, Gja1, and Synataxin on VGLUT1 expression. RESULTS A total of 255 and 225 proteins and 172 known genes were identified in the pull down assay, co-immunoprecipitation assay, or split-ubiquitin yeast two-hybrid screening respectively. The physiological interactions of SV2A, Syntaxin 12, Gja1, AβPP, and Atp6ap2 to VGLUT1 were further confirmed. Knockdown of Atp6ap2, Gja1, and Synataxin increased VGLUT1 mRNA expression and only knockdown of AβPP increased both mRNA and protein levels of VGLUT1 in PC12 cells. The regulatory function of AβPP on VGLUT1 expression was further confirmed in the in vitro and in vivo models. CONCLUSION These results elucidate that the AβPP and VGLUT1 interacts at vesicular level and AβPP plays a role in the regulation of VGLUT1 expression which is essential for maintaining vesicular activities.
Collapse
Affiliation(s)
- Jin-Wu Zhou
- School of Chemical Engineering and Technology, Tianjin University, Tianjin, China
| | - Man Zhao
- Department of Blood Transfusion, Chinese PLA General Hospital, Beijing, China
| | - Wen-Liang Rang
- Department of Experimental Hematology, Beijing Institute of Radiation Medicine, Beijing, China
| | - Xiao-Yan Zhang
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing, China
| | - Zhen-Ming Liu
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing, China
| | - Liang-Ren Zhang
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing, China
| | - Tong-Xing Wang
- Beijing Institute of Pharmacology and Toxicology, Beijing, China
| | - Chu-Tse Wu
- School of Chemical Engineering and Technology, Tianjin University, Tianjin, China.,Department of Experimental Hematology, Beijing Institute of Radiation Medicine, Beijing, China
| | - Xiao-Rui Cheng
- Beijing Institute of Pharmacology and Toxicology, Beijing, China.,State Key Laboratory of Toxicology and Medical Countermeasures, Beijing, China
| | - Wen-Xia Zhou
- Beijing Institute of Pharmacology and Toxicology, Beijing, China.,State Key Laboratory of Toxicology and Medical Countermeasures, Beijing, China
| |
Collapse
|
15
|
Nakakubo Y, Abe S, Yoshida T, Takami C, Isa M, Wojcik SM, Brose N, Takamori S, Hori T. Vesicular Glutamate Transporter Expression Ensures High-Fidelity Synaptic Transmission at the Calyx of Held Synapses. Cell Rep 2021; 32:108040. [PMID: 32814044 DOI: 10.1016/j.celrep.2020.108040] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Revised: 07/01/2020] [Accepted: 07/24/2020] [Indexed: 12/26/2022] Open
Abstract
Recycling of synaptic vesicles (SVs) at presynaptic terminals is required for sustained neurotransmitter release. Although SV endocytosis is a rate-limiting step for synaptic transmission, it is unclear whether the rate of the subsequent SV refilling with neurotransmitter also influences synaptic transmission. By analyzing vesicular glutamate transporter 1 (VGLUT1)-deficient calyx of Held synapses, in which both VGLUT1 and VGLUT2 are co-expressed in wild-type situation, we found that VGLUT1 loss causes a drastic reduction in SV refilling rate down to ∼25% of wild-type values, with only subtle changes in basic synaptic parameters. Strikingly, VGLUT1-deficient synapses exhibited abnormal synaptic failures within a few seconds during high-frequency repetitive firing, which was recapitulated by manipulating presynaptic Cl- concentrations to retard SV refilling. Our data show that the speed of SV refilling can be rate limiting for synaptic transmission under certain conditions that entail reduced VGLUT levels during development as well as various neuropathological processes.
Collapse
Affiliation(s)
- Yutaro Nakakubo
- Department of Neurophysiology, Graduate School of Life and Medical Sciences, Doshisha University, Kyoto 610-0394, Japan
| | - Saeka Abe
- Department of Neurophysiology, Graduate School of Life and Medical Sciences, Doshisha University, Kyoto 610-0394, Japan
| | - Tomofumi Yoshida
- Laboratory of Neural Membrane Biology, Graduate School of Brain Science, Doshisha University, Kyoto 610-0394, Japan
| | - Chihiro Takami
- Laboratory of Neural Membrane Biology, Graduate School of Brain Science, Doshisha University, Kyoto 610-0394, Japan
| | - Masayuki Isa
- Laboratory of Neural Membrane Biology, Graduate School of Brain Science, Doshisha University, Kyoto 610-0394, Japan
| | - Sonja M Wojcik
- Department of Molecular Neurobiology, Max Planck Institute for Experimental Medicine, Göttingen 37075, Germany
| | - Nils Brose
- Department of Molecular Neurobiology, Max Planck Institute for Experimental Medicine, Göttingen 37075, Germany
| | - Shigeo Takamori
- Laboratory of Neural Membrane Biology, Graduate School of Brain Science, Doshisha University, Kyoto 610-0394, Japan.
| | - Tetsuya Hori
- Department of Neurophysiology, Graduate School of Life and Medical Sciences, Doshisha University, Kyoto 610-0394, Japan.
| |
Collapse
|
16
|
Schoonover KE, Dienel SJ, Lewis DA. Prefrontal cortical alterations of glutamate and GABA neurotransmission in schizophrenia: Insights for rational biomarker development. Biomark Neuropsychiatry 2020; 3. [PMID: 32656540 PMCID: PMC7351254 DOI: 10.1016/j.bionps.2020.100015] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Certain cognitive deficits in schizophrenia, such as impaired working memory, are thought to reflect alterations in the neural circuitry of the dorsolateral prefrontal cortex (DLPFC). Gamma oscillations in the DLPFC appear to be a neural corollary of working memory function, and the power of these oscillations during working memory tasks is lower in individuals with schizophrenia. Thus, gamma oscillations represent a potentially useful biomarker to index dysfunction in the DLPFC circuitry responsible for working memory in schizophrenia. Postmortem studies, by identifying the cellular basis of DLPFC dysfunction, can help inform the utility of biomarker measures obtained in vivo. Given that gamma oscillations reflect network activity of excitatory pyramidal neurons and inhibitory GABA neurons, we review postmortem findings of alterations to both cell types in the DLPFC and discuss how these findings might inform future biomarker development and use.
Collapse
Affiliation(s)
- Kirsten E Schoonover
- Translational Neuroscience Program, Department of Psychiatry, School of Medicine, University of Pittsburgh, United States
| | - Samuel J Dienel
- Translational Neuroscience Program, Department of Psychiatry, School of Medicine, University of Pittsburgh, United States.,Medical Scientist Training Program, University of Pittsburgh, United States.,Department of Neuroscience, Dietrich School of Arts and Sciences, University of Pittsburgh, United States.,Center for the Neural Basis of Cognition, Carnegie Mellon University, United States
| | - David A Lewis
- Translational Neuroscience Program, Department of Psychiatry, School of Medicine, University of Pittsburgh, United States.,Department of Neuroscience, Dietrich School of Arts and Sciences, University of Pittsburgh, United States.,Center for the Neural Basis of Cognition, Carnegie Mellon University, United States
| |
Collapse
|
17
|
Li F, Eriksen J, Finer-Moore J, Chang R, Nguyen P, Bowen A, Myasnikov A, Yu Z, Bulkley D, Cheng Y, Edwards RH, Stroud RM. Ion transport and regulation in a synaptic vesicle glutamate transporter. Science 2020; 368:893-897. [PMID: 32439795 DOI: 10.1126/science.aba9202] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Accepted: 03/27/2020] [Indexed: 12/28/2022]
Abstract
Synaptic vesicles accumulate neurotransmitters, enabling the quantal release by exocytosis that underlies synaptic transmission. Specific neurotransmitter transporters are responsible for this activity and therefore are essential for brain function. The vesicular glutamate transporters (VGLUTs) concentrate the principal excitatory neurotransmitter glutamate into synaptic vesicles, driven by membrane potential. However, the mechanism by which they do so remains poorly understood owing to a lack of structural information. We report the cryo-electron microscopy structure of rat VGLUT2 at 3.8-angstrom resolution and propose structure-based mechanisms for substrate recognition and allosteric activation by low pH and chloride. A potential permeation pathway for chloride intersects with the glutamate binding site. These results demonstrate how the activity of VGLUTs can be coordinated with large shifts in proton and chloride concentrations during the synaptic vesicle cycle to ensure normal synaptic transmission.
Collapse
Affiliation(s)
- Fei Li
- Department of Biochemistry and Biophysics, University of California San Francisco (UCSF) School of Medicine, San Francisco, CA, USA.,Departments of Neurology and Physiology, UCSF School of Medicine, San Francisco, CA, USA
| | - Jacob Eriksen
- Departments of Neurology and Physiology, UCSF School of Medicine, San Francisco, CA, USA
| | - Janet Finer-Moore
- Department of Biochemistry and Biophysics, University of California San Francisco (UCSF) School of Medicine, San Francisco, CA, USA
| | - Roger Chang
- Departments of Neurology and Physiology, UCSF School of Medicine, San Francisco, CA, USA.,Graduate Program in Biomedical Sciences, UCSF, San Francisco, CA, USA
| | - Phuong Nguyen
- Department of Biochemistry and Biophysics, University of California San Francisco (UCSF) School of Medicine, San Francisco, CA, USA
| | - Alisa Bowen
- Department of Biochemistry and Biophysics, University of California San Francisco (UCSF) School of Medicine, San Francisco, CA, USA
| | - Alexander Myasnikov
- Department of Biochemistry and Biophysics, University of California San Francisco (UCSF) School of Medicine, San Francisco, CA, USA
| | - Zanlin Yu
- Department of Biochemistry and Biophysics, University of California San Francisco (UCSF) School of Medicine, San Francisco, CA, USA
| | - David Bulkley
- Department of Biochemistry and Biophysics, University of California San Francisco (UCSF) School of Medicine, San Francisco, CA, USA
| | - Yifan Cheng
- Department of Biochemistry and Biophysics, University of California San Francisco (UCSF) School of Medicine, San Francisco, CA, USA.,Howard Hughes Medical Institute, UCSF, San Francisco, CA, USA
| | - Robert H Edwards
- Departments of Neurology and Physiology, UCSF School of Medicine, San Francisco, CA, USA.
| | - Robert M Stroud
- Department of Biochemistry and Biophysics, University of California San Francisco (UCSF) School of Medicine, San Francisco, CA, USA.
| |
Collapse
|
18
|
Pietrancosta N, Djibo M, Daumas S, El Mestikawy S, Erickson JD. Molecular, Structural, Functional, and Pharmacological Sites for Vesicular Glutamate Transporter Regulation. Mol Neurobiol 2020; 57:3118-3142. [PMID: 32474835 PMCID: PMC7261050 DOI: 10.1007/s12035-020-01912-7] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Accepted: 03/30/2020] [Indexed: 12/11/2022]
Abstract
Vesicular glutamate transporters (VGLUTs) control quantal size of glutamatergic transmission and have been the center of numerous studies over the past two decades. VGLUTs contain two independent transport modes that facilitate glutamate packaging into synaptic vesicles and phosphate (Pi) ion transport into the synaptic terminal. While a transmembrane proton electrical gradient established by a vacuolar-type ATPase powers vesicular glutamate transport, recent studies indicate that binding sites and flux properties for chloride, potassium, and protons within VGLUTs themselves regulate VGLUT activity as well. These intrinsic ionic binding and flux properties of VGLUTs can therefore be modulated by neurophysiological conditions to affect levels of glutamate available for release from synapses. Despite their extraordinary importance, specific and high-affinity pharmacological compounds that interact with these sites and regulate VGLUT function, distinguish between the various modes of transport, and the different isoforms themselves, are lacking. In this review, we provide an overview of the physiologic sites for VGLUT regulation that could modulate glutamate release in an over-active synapse or in a disease state.
Collapse
Affiliation(s)
- Nicolas Pietrancosta
- Neuroscience Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS) INSERM, CNRS, Sorbonne Université, Paris, France. .,Laboratoire des Biomolécules, Sorbonne Université, CNRS, ENS, LBM, 75005, Paris, France.
| | - Mahamadou Djibo
- Sorbonne Paris Cité, Université Paris Descartes, LCBPT, UMR 8601, 75006, Paris, France
| | - Stephanie Daumas
- Neuroscience Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS) INSERM, CNRS, Sorbonne Université, Paris, France
| | - Salah El Mestikawy
- Neuroscience Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS) INSERM, CNRS, Sorbonne Université, Paris, France. .,Douglas Hospital Research Center, Department of Psychiatry, McGill University, 6875 boulevard Lasalle, Verdun, Montreal, QC, Canada.
| | - Jeffrey D Erickson
- Neuroscience Center, Louisiana State University, New Orleans, LA, 70112, USA. .,Department of Pharmacology, Louisiana State University, New Orleans, LA, 70112, USA.
| |
Collapse
|
19
|
Mallya AP, Wang HD, Lee HNR, Deutch AY. Microglial Pruning of Synapses in the Prefrontal Cortex During Adolescence. Cereb Cortex 2020; 29:1634-1643. [PMID: 29668872 DOI: 10.1093/cercor/bhy061] [Citation(s) in RCA: 90] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Revised: 02/19/2018] [Accepted: 02/22/2018] [Indexed: 12/20/2022] Open
Abstract
Exaggerated synaptic elimination in the prefrontal cortex (PFC) during adolescence has been suggested to contribute to the neuropathological changes of schizophrenia. Recent data indicate that microglia (MG) sculpt synapses during early postnatal development. However, it is not known if MG contribute to the structural maturation of the PFC, which has a protracted postnatal development. We determined if MG are involved in developmentally specific synapse elimination in the PFC, focusing on adolescence. Layer 5 PFC pyramidal cells (PCs) were intracellularly filled with Lucifer Yellow for dendritic spine measurements in postnatal day (P) 24, P30, P35, P39, and P50 rats. In the contralateral PFC we evaluated if MG engulfed presynaptic (glutamatergic) and postsynaptic (dendritic spines) elements. Dendritic spine density increased from P24 to P35, when spine density peaked. There was a significant increase in MG engulfment of spines at P39 relative to earlier ages; this subsided by P50. MG also phagocytosed presynaptic glutamatergic terminals. These data indicate that MG transiently prune synapses of PFC PCs during adolescence, when the symptoms of schizophrenia typically first appear. An increase in MG-mediated synaptic remodeling of PFC PCs may contribute to the structural changes observed in schizophrenia.
Collapse
Affiliation(s)
| | - Hui-Dong Wang
- Department of Psychiatry and Behavioral Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Han Noo Ri Lee
- Neuroscience Program, Vanderbilt University, Nashville, TN, USA
| | - Ariel Y Deutch
- Neuroscience Program, Vanderbilt University, Nashville, TN, USA.,Department of Psychiatry and Behavioral Sciences, Vanderbilt University Medical Center, Nashville, TN, USA.,Department of Pharmacology, Vanderbilt University, Nashville, TN, USA
| |
Collapse
|
20
|
Bitanihirwe BKY, Woo TUW. A conceptualized model linking matrix metalloproteinase-9 to schizophrenia pathogenesis. Schizophr Res 2020; 218:28-35. [PMID: 32001079 DOI: 10.1016/j.schres.2019.12.015] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Revised: 12/18/2019] [Accepted: 12/18/2019] [Indexed: 12/11/2022]
Abstract
Matrix metalloproteinase 9 (MMP-9) is an extracellularly operating zinc-dependent endopeptidase that is commonly expressed in the brain, other tissues. It is synthesized in a latent zymogen form known as pro-MMP-9 that is subsequently converted to the active MMP-9 enzyme following cleavage of the pro-domain. Within the central nervous system, MMP-9 is localized and released from neurons, astrocytes and microglia where its expression levels are modulated by cytokines and growth factors during both normal and pathological conditions as well as by reactive oxygen species generated during oxidative stress. MMP-9 is involved in a number of key neurodevelopmental processes that are thought to be affected in schizophrenia, including maturation of the inhibitory neurons that contain the calcium-binding protein parvalbumin, developmental formation of the specialized extracellular matrix structure perineuronal net, synaptic pruning, and myelination. In this context, the present article provides a narrative synthesis of the existing evidence linking MMP-9 dysregulation to schizophrenia pathogenesis. We start by providing an overview of MMP-9 involvement in brain development and physiology. We then discuss the potential mechanisms through which MMP-9 dysregulation may affect neural circuitry maturation as well as how these anomalies may contribute to the disease process of schizophrenia. We conclude by articulating a comprehensive, cogent, and experimentally testable hypothesis linking MMP-9 to the developmental pathophysiologic cascade that triggers the onset and sustains the chronicity of the illness.
Collapse
Affiliation(s)
| | - Tsung-Ung W Woo
- Department of Psychiatry, Beth Israel Deaconess Medical Center, Boston, MA, USA; Program in Cellular Neuropathology, McLean Hospital, Belmont, MA, USA; Department of Psychiatry, Harvard Medical School, Boston, MA, USA.
| |
Collapse
|
21
|
Poirel O, Mamer LE, Herman MA, Arnulf-Kempcke M, Kervern M, Potier B, Miot S, Wang J, Favre-Besse FC, Brabet I, Laras Y, Bertrand HO, Acher F, Pin JP, Puel JL, Giros B, Epelbaum J, Rosenmund C, Dutar P, Daumas S, El Mestikawy S, Pietrancosta N. LSP5-2157 a new inhibitor of vesicular glutamate transporters. Neuropharmacology 2019; 164:107902. [PMID: 31811873 DOI: 10.1016/j.neuropharm.2019.107902] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Revised: 10/08/2019] [Accepted: 12/02/2019] [Indexed: 11/19/2022]
Abstract
Vesicular glutamate transporters (VGLUT1-3) mediate the uptake of glutamate into synaptic vesicles. VGLUTs are pivotal actors of excitatory transmission and of almost all brain functions. Their implication in various pathologies has been clearly documented. Despite their functional importance, the pharmacology of VGLUTs is limited to a few dyes such as Trypan Blue, Rose Bengal or Brilliant Yellow type. Here, we report the design and evaluation of new potent analogs based on Trypan Blue scaffold. Our best compound, named LSP5-2157, has an EC50 of 50 nM on glutamate vesicular uptake. Using a 3D homology model of VGLUT1 and docking experiments, we determined its putative binding subdomains within vesicular glutamate transporters and validated the structural requirement for VGLUT inhibition. To better estimate the specificity and potency of LSP5-2157, we also investigated its ability to block glutamatergic transmission in autaptic hippocampal cells. Neither glutamate receptors nor GABAergic transmission or transmission machinery were affected by LSP5-2157. Low doses of compound reversibly reduce glutamatergic neurotransmission in hippocampal autpases. LSP5-2157 had a low and depressing effect on synaptic efficacy in hippocampal slice. Furthermore, LSP5-2157 had no effect on NMDA-R- mediated fEPSP but reduce synaptic plasticity induced by 3 trains of 100 Hz. Finally, LSP5-2157 had the capacity to inhibit VGLUT3-dependent auditory synaptic transmission in the guinea pig cochlea. In this model, it abolished the compound action potential of auditory nerve at high concentration showing the limited permeation of LSP5-2157 in an in-vivo model. In summary, the new ligand LSP5-2157, has a high affinity and specificity for VGLUTs and shows some permeability in isolated neuron, tissue preparations or in vivo in the auditory system. These findings broaden the field of VGLUTs inhibitors and open the way to their use to assess glutamatergic functions in vitro and in vivo.
Collapse
Affiliation(s)
- Odile Poirel
- Sorbonne Université, INSERM, CNRS, Neurosciences Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS), 75005, Paris, France
| | - Lauren E Mamer
- Institut für Neurophysiologie, Charité Universitätsmedizin, Charitéplatz 1, 10117, Berlin, Germany; The Ohio State University College of Medicine, The Ohio State University, Columbus, OH, 43210, USA
| | - Melissa A Herman
- Institut für Neurophysiologie, Charité Universitätsmedizin, Charitéplatz 1, 10117, Berlin, Germany
| | - Marie Arnulf-Kempcke
- Centre de Psychiatrie et Neurosciences, Université Paris Descartes, Sorbonne Paris Cité, UMR 894, Paris, 75014, France
| | - Myriam Kervern
- Centre de Psychiatrie et Neurosciences, Université Paris Descartes, Sorbonne Paris Cité, UMR 894, Paris, 75014, France
| | - Brigitte Potier
- Centre de Psychiatrie et Neurosciences, Université Paris Descartes, Sorbonne Paris Cité, UMR 894, Paris, 75014, France; Present address: Laboratoire Aimée Cotton, CNRS, Université Paris-Sud, ENS Paris-Saclay, 91405, Orsay, France
| | - Stephanie Miot
- Sorbonne Université, INSERM, CNRS, Neurosciences Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS), 75005, Paris, France; Institute for Neuroscience Montpellier (INM), INSERM U1051, Université Montpellier, 34091, Montpellier, France
| | - Jing Wang
- Institute for Neuroscience Montpellier (INM), INSERM U1051, Université Montpellier, 34091, Montpellier, France
| | | | - Isabelle Brabet
- Institut de Génomique Fonctionnelle UMR 5203 CNRS - U 1191 INSERM - Univ. Montpellier, 30094, Montpellier, France
| | - Younès Laras
- LCBPT, Université Paris Descartes, Sorbonne Paris Cité, UMR 8601, CNRS, Paris, 75006, France
| | - Hugues-Olivier Bertrand
- BIOVIA, Dassault Systèmes, 10 rue Marcel Dassault, CS 40501, 78946, Velizy-Villacoublay Cedex, France
| | - Francine Acher
- LCBPT, Université Paris Descartes, Sorbonne Paris Cité, UMR 8601, CNRS, Paris, 75006, France
| | - Jean-Philippe Pin
- Institut de Génomique Fonctionnelle UMR 5203 CNRS - U 1191 INSERM - Univ. Montpellier, 30094, Montpellier, France
| | - Jean-Luc Puel
- Institute for Neuroscience Montpellier (INM), INSERM U1051, Université Montpellier, 34091, Montpellier, France
| | - Bruno Giros
- Sorbonne Université, INSERM, CNRS, Neurosciences Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS), 75005, Paris, France; Douglas Hospital Research Center, Department of Psychiatry, McGill University, 6875, boulevard Lasalle Verdun, QC, Canada
| | - Jacques Epelbaum
- Centre de Psychiatrie et Neurosciences, Université Paris Descartes, Sorbonne Paris Cité, UMR 894, Paris, 75014, France
| | - Christian Rosenmund
- Institut für Neurophysiologie, Charité Universitätsmedizin, Charitéplatz 1, 10117, Berlin, Germany
| | - Patrick Dutar
- Centre de Psychiatrie et Neurosciences, Université Paris Descartes, Sorbonne Paris Cité, UMR 894, Paris, 75014, France; Present address: Laboratoire Aimée Cotton, CNRS, Université Paris-Sud, ENS Paris-Saclay, 91405, Orsay, France
| | - Stephanie Daumas
- Sorbonne Université, INSERM, CNRS, Neurosciences Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS), 75005, Paris, France
| | - Salah El Mestikawy
- Sorbonne Université, INSERM, CNRS, Neurosciences Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS), 75005, Paris, France; Douglas Hospital Research Center, Department of Psychiatry, McGill University, 6875, boulevard Lasalle Verdun, QC, Canada.
| | - Nicolas Pietrancosta
- Sorbonne Université, INSERM, CNRS, Neurosciences Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS), 75005, Paris, France; LCBPT, Université Paris Descartes, Sorbonne Paris Cité, UMR 8601, CNRS, Paris, 75006, France; Sorbonne Université, École normale supérieure, PSL University, CNRS, Laboratoire des Biomolécules, LBM, 75005 Paris, France.
| |
Collapse
|
22
|
Thaweethee B, Suttajit S, Thanoi S, Dalton CF, Reynolds GP, Nudmamud-Thanoi S. Association of SLC1A2 and SLC17A7 polymorphisms with major depressive disorder in a Thai population. ASIAN BIOMED 2019. [DOI: 10.1515/abm-2019-0012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
Background
Major depressive disorder (MDD) is a common psychiatric disorder with high prevalence and high risk of suicide. Genetic variation of glutamate transporters may associate with MDD and suicide attempt.
Objectives
To evaluate polymorphisms of excitatory amino acid transporter 2 gene (SLC1A2; rs752949, rs1885343, rs4755404, and rs4354668) and vesicular glutamate transporter 1 gene (SLC17A7; rs1043558, rs2946848, and rs11669017) in patients with MDD with and without suicide attempt, and determine the association of these polymorphisms with age of onset and severity of MDD.
Methods
DNA was extracted from blood taken from patients with MDD (n = 100; including nonsuicidal [n = 50] and suicidal [n = 50] subgroups) and controls (n = 100). Genotyping was conducted using TaqMan single-nucleotide polymorphism (SNP) genotyping.
Results
We found a significant difference in SLC17A7 rs2946848 genotype distribution between patients in the MDD and control groups (P = 0.016). Moreover, significant differences in SLC1A2 rs752949 (P = 0.022) and SLC17A7 rs2946848 (P = 0.026) genotype distributions were observed between patients in the nonsuicidal MDD and suicidal MDD groups. SLC1A2 rs1885343 A allele carriers showed significantly lower age of onset than GG genotype (P = 0.049). Furthermore, the severity of MDD indicated by the Hamilton Depression Rating Scale (HDRS) score of G allele carriers of SLC1A2 rs4755404 was significantly greater than the CC genotype (P = 0.013).
Conclusions
Polymorphisms of SLC1A2 and SLC17A7 may contribute to the risk of MDD and/or suicide attempt. An association of an SLC1A2 polymorphism with the severity of MDD was apparent.
Collapse
Affiliation(s)
- Benjamard Thaweethee
- Department of Anatomy, Faculty of Medical Science, Naresuan University , Phitsanulok 65000 , Thailand
- Centre of Excellence in Medical Biotechnology, Faculty of Medical Science, Naresuan University , Phitsanulok 65000 , Thailand
| | - Sirijit Suttajit
- Department of Psychiatry, Faculty of Medicine, Chiang Mai University , Chiang Mai 50200 , Thailand
| | - Samur Thanoi
- Department of Anatomy, Faculty of Medical Science, Naresuan University , Phitsanulok 65000 , Thailand
- Centre of Excellence in Medical Biotechnology, Faculty of Medical Science, Naresuan University , Phitsanulok 65000 , Thailand
| | - Caroline F. Dalton
- Biomolecular Sciences Research Centre, Sheffield Hallam University , Sheffield S1 1WB , UK
| | - Gavin P. Reynolds
- Centre of Excellence in Medical Biotechnology, Faculty of Medical Science, Naresuan University , Phitsanulok 65000 , Thailand
- Biomolecular Sciences Research Centre, Sheffield Hallam University , Sheffield S1 1WB , UK
| | - Sutisa Nudmamud-Thanoi
- Department of Anatomy, Faculty of Medical Science, Naresuan University , Phitsanulok 65000 , Thailand
- Centre of Excellence in Medical Biotechnology, Faculty of Medical Science, Naresuan University , Phitsanulok 65000 , Thailand
| |
Collapse
|
23
|
Scott MR, Meador-Woodruff JH. Intracellular compartment-specific proteasome dysfunction in postmortem cortex in schizophrenia subjects. Mol Psychiatry 2019; 25:776-790. [PMID: 30683941 PMCID: PMC6658356 DOI: 10.1038/s41380-019-0359-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Revised: 12/19/2018] [Accepted: 01/11/2019] [Indexed: 12/19/2022]
Abstract
Protein homeostasis is an emerging component of schizophrenia (SZ) pathophysiology. Proteomic alterations in SZ are well-documented and changes in transcript expression are frequently not associated with changes in protein expression in SZ brain. The underlying mechanism driving these changes remains unknown, though altered expression of ubiquitin proteasome system (UPS) components have implicated protein degradation. Previous studies have been limited to protein and transcript expression, however, and do not directly test the function of the proteasome. To address this gap in knowledge, we measured enzymatic activity associated with the proteasome (chymotrypsin-, trypsin-, and caspase-like) in the superior temporal gyrus (STG) of 25 SZ and 25 comparison subjects using flourogenic substrates. As localization regulates which cellular processes the proteasome contributes to, we measured proteasome activity and subunit expression in fractions enriched for nucleus, cytosolic, and membrane compartments. SZ subjects had decreased trypsin-like activity in total homogenate. This finding was specific to the nucleus-enriched fraction and was not associated with changes in proteasome subunit expression. Interestingly, both chymotrypsin-like activity and protein expression of 19S RP subunits, which facilitate ubiquitin-dependent degradation, were decreased in the cytosol-enriched fraction of SZ subjects. Intracellular compartment-specific proteasome dysfunction implicates dysregulation of protein expression both through altered ubiquitin-dependent degradation of cytosolic proteins and regulation of protein synthesis due to degradation of transcription factors and transcription machinery in the nucleus. Together, these findings implicate proteasome dysfunction in SZ, which likely has a broad impact on the proteomic landscape and cellular function in the pathophysiology of this illness.
Collapse
Affiliation(s)
- Madeline R. Scott
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - James H. Meador-Woodruff
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| |
Collapse
|
24
|
Zygmunt M, Piechota M, Rodriguez Parkitna J, Korostyński M. Decoding the transcriptional programs activated by psychotropic drugs in the brain. GENES BRAIN AND BEHAVIOR 2018; 18:e12511. [PMID: 30084543 DOI: 10.1111/gbb.12511] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Revised: 07/25/2018] [Accepted: 08/03/2018] [Indexed: 01/01/2023]
Abstract
Analysis of drug-induced gene expression in the brain has long held the promise of revealing the molecular mechanisms of drug actions as well as predicting their long-term clinical efficacy. However, despite some successes, this promise has yet to be fulfilled. Here, we present an overview of the current state of understanding of drug-induced gene expression in the brain and consider the obstacles to achieving a robust prediction of the properties of psychoactive compounds based on gene expression profiles. We begin with a comprehensive overview of the mechanisms controlling drug-inducible transcription and the complexity resulting from expression of noncoding RNAs and alternative gene isoforms. Particular interest is placed on studies that examine the associations within drug classes with regard to the effects on gene transcription, alterations in cell signaling and neuropharmacological drug properties. While the ability of gene expression signatures to distinguish specific clinical classes of psychotropic and addictive drugs remains unclear, some reports show that under specific constraints, drug properties can be predicted based on gene expression. Such signatures offer a simple and effective way to classify psychotropic drugs and screen novel psychoactive compounds. Finally, we note that the amount of data regarding molecular programs activated in the brain by drug treatment has grown exponentially in recent years and that future advances may therefore come in large part from integrating the currently available high-throughput data sets.
Collapse
Affiliation(s)
- Magdalena Zygmunt
- Department of Molecular Neuropharmacology, Institute of Pharmacology of the Polish Academy of Sciences, Krakow, Poland
| | - Marcin Piechota
- Department of Molecular Neuropharmacology, Institute of Pharmacology of the Polish Academy of Sciences, Krakow, Poland
| | - Jan Rodriguez Parkitna
- Department of Molecular Neuropharmacology, Institute of Pharmacology of the Polish Academy of Sciences, Krakow, Poland
| | - Michał Korostyński
- Department of Molecular Neuropharmacology, Institute of Pharmacology of the Polish Academy of Sciences, Krakow, Poland
| |
Collapse
|
25
|
Abstract
Contrary to the notion that neurology but not psychiatry is the domain of disorders evincing structural brain alterations, it is now clear that there are subtle but consistent neuropathological changes in schizophrenia. These range from increases in ventricular size to dystrophic changes in dendritic spines. A decrease in dendritic spine density in the prefrontal cortex (PFC) is among the most replicated of postmortem structural findings in schizophrenia. Examination of the mechanisms that account for the loss of dendritic spines has in large part focused on genes and molecules that regulate neuronal structure. But the simple question of what is the effector of spine loss, ie, where do the lost spines go, is unanswered. Recent data on glial cells suggest that microglia (MG), and perhaps astrocytes, play an important physiological role in synaptic remodeling of neurons during development. Synapses are added to the dendrites of pyramidal cells during the maturation of these neurons; excess synapses are subsequently phagocytosed by MG. In the PFC, this occurs during adolescence, when certain symptoms of schizophrenia emerge. This brief review discusses recent advances in our understanding of MG function and how these non-neuronal cells lead to structural changes in neurons in schizophrenia.
Collapse
Affiliation(s)
| | - Ariel Y Deutch
- Neuroscience Program, Vanderbilt University, Nashville, TN
- Department of Psychiatry and Behavioral Sciences, Vanderbilt University Medical Center, Nashville, TN
- Department of Pharmacology, Vanderbilt University, Nashville, TN
| |
Collapse
|
26
|
Sullivan CR, O'Donovan SM, McCullumsmith RE, Ramsey A. Defects in Bioenergetic Coupling in Schizophrenia. Biol Psychiatry 2018; 83:739-750. [PMID: 29217297 PMCID: PMC5891385 DOI: 10.1016/j.biopsych.2017.10.014] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Revised: 09/18/2017] [Accepted: 10/09/2017] [Indexed: 02/06/2023]
Abstract
Synaptic neurotransmission relies on maintenance of the synapse and meeting the energy demands of neurons. Defects in excitatory and inhibitory synapses have been implicated in schizophrenia, likely contributing to positive and negative symptoms as well as impaired cognition. Recently, accumulating evidence has suggested that bioenergetic systems, important in both synaptic function and cognition, are abnormal in psychiatric illnesses such as schizophrenia. Animal models of synaptic dysfunction demonstrated endophenotypes of schizophrenia as well as bioenergetic abnormalities. We report findings on the bioenergetic interplay of astrocytes and neurons and discuss how dysregulation of these pathways may contribute to the pathogenesis of schizophrenia, highlighting metabolic systems as important therapeutic targets.
Collapse
Affiliation(s)
- Courtney R Sullivan
- Department of Psychiatry and Behavioral Neuroscience, University of Cincinnati, Cincinnati, Ohio
| | - Sinead M O'Donovan
- Department of Psychiatry and Behavioral Neuroscience, University of Cincinnati, Cincinnati, Ohio
| | - Robert E McCullumsmith
- Department of Psychiatry and Behavioral Neuroscience, University of Cincinnati, Cincinnati, Ohio.
| | - Amy Ramsey
- Department of Pharmacology and Toxicology, University of Toronto, Ontario, Canada
| |
Collapse
|
27
|
Boksha IS, Tereshkina EB, Savushkina OK, Prokhorova TA, Vorobyeva EA, Burbaeva GS. Comparative Studies of Glutamine Synthetase Levels in the Brains of Patients with Schizophrenia and Mentally Healthy People. NEUROCHEM J+ 2018. [DOI: 10.1134/s1819712418010026] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
|
28
|
Sathyasaikumar KV, Tararina M, Wu HQ, Neale SA, Weisz F, Salt TE, Schwarcz R. Xanthurenic Acid Formation from 3-Hydroxykynurenine in the Mammalian Brain: Neurochemical Characterization and Physiological Effects. Neuroscience 2017; 367:85-97. [PMID: 29031603 PMCID: PMC5819007 DOI: 10.1016/j.neuroscience.2017.10.006] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Revised: 10/02/2017] [Accepted: 10/04/2017] [Indexed: 02/09/2023]
Abstract
Xanthurenic acid (XA), formed from 3-hydroxykynurenine (3-HK) in the kynurenine pathway of tryptophan degradation, may modulate glutamatergic neurotransmission by inhibiting the vesicular glutamate transporter and/or activating Group II metabotropic glutamate receptors. Here we examined the molecular and cellular mechanisms by which 3-HK controls the neosynthesis of XA in rat, mouse and human brain, and compared the physiological actions of 3-HK and XA in the rat brain. In tissue homogenates, XA formation from 3-HK was observed in all three species and traced to a major role of kynurenine aminotransferase II (KAT II). Transamination of 3-HK to XA was also demonstrated using human recombinant KAT II. Neosynthesis of XA was significantly increased in the quinolinate-lesioned rat striatum, indicating a non-neuronal localization of the process. Studies using rat cortical slices revealed that newly produced XA is rapidly released into the extracellular compartment, and that XA biosynthesis can be manipulated experimentally in the same way as the production of kynurenic acid from kynurenine (omission of Na+ or glucose, depolarizing conditions, or addition of 2-oxoacids). The synthesis of XA from 3-HK was confirmed in vivo by striatal microdialysis. In slices from the rat hippocampus, both 3-HK and XA reduced the slopes of dentate gyrus field EPSPs. The effect of 3-HK was reduced in the presence of the KAT inhibitor aminooxyacetic acid. Finally, both 3-HK and XA reduced the power of gamma-oscillatory activity recorded from the hippocampal CA3 region. Endogenous XA, newly formed from 3-HK, may therefore play a physiological role in attentional and cognitive processes.
Collapse
Affiliation(s)
- K V Sathyasaikumar
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD 21228, USA
| | - M Tararina
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD 21228, USA
| | - H-Q Wu
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD 21228, USA
| | - S A Neale
- Institute of Ophthalmology, University College London, London, UK; Neurexpert Ltd., London, UK
| | - F Weisz
- Institute of Ophthalmology, University College London, London, UK
| | - T E Salt
- Institute of Ophthalmology, University College London, London, UK; Neurexpert Ltd., London, UK
| | - R Schwarcz
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD 21228, USA.
| |
Collapse
|
29
|
Martineau M, Guzman RE, Fahlke C, Klingauf J. VGLUT1 functions as a glutamate/proton exchanger with chloride channel activity in hippocampal glutamatergic synapses. Nat Commun 2017; 8:2279. [PMID: 29273736 PMCID: PMC5741633 DOI: 10.1038/s41467-017-02367-6] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Accepted: 11/24/2017] [Indexed: 12/18/2022] Open
Abstract
Glutamate is the major excitatory transmitter in the vertebrate nervous system. To maintain synaptic efficacy, recycling synaptic vesicles (SV) are refilled with glutamate by vesicular glutamate transporters (VGLUTs). The dynamics and mechanism of glutamate uptake in intact neurons are still largely unknown. Here, we show by live-cell imaging with pH- and chloride-sensitive fluorescent probes in cultured hippocampal neurons of wild-type and VGLUT1-deficient mice that in SVs VGLUT functions as a glutamate/proton exchanger associated with a channel-like chloride conductance. After endocytosis most internalized Cl− is substituted by glutamate in an electrically, and presumably osmotically, neutral manner, and this process is driven by both the Cl− gradient itself and the proton motive force provided by the vacuolar H+-ATPase. Our results shed light on the transport mechanism of VGLUT under physiological conditions and provide a framework for how modulation of glutamate transport via Cl− and pH can change synaptic strength. During neurotransmission synaptic vesicles are filled with glutamate by vesicular glutamate transporters (VGLUTs). Here, authors image intact neurons and show that in synaptic vesicles VGLUT functions as a glutamate/proton exchanger associated with a channel-like chloride conductance.
Collapse
Affiliation(s)
- Magalie Martineau
- Department of Cellular Biophysics, Institute for Medical Physics and Biophysics, University of Muenster, 48149, Muenster, Germany. .,University of Bordeaux and Centre National de la Recherche Scientifique, Interdisciplinary Institute for Neuroscience, UMR 5297, F-33000, Bordeaux, France.
| | - Raul E Guzman
- Institute of Complex Systems, Zelluläre Biophysik (ICS-4), Forschungszentrum Jülich, 52425, Jülich, Germany
| | - Christoph Fahlke
- Institute of Complex Systems, Zelluläre Biophysik (ICS-4), Forschungszentrum Jülich, 52425, Jülich, Germany
| | - Jürgen Klingauf
- Department of Cellular Biophysics, Institute for Medical Physics and Biophysics, University of Muenster, 48149, Muenster, Germany. .,IZKF Münster and Cluster of Excellence EXC 1003, Cells in Motion (CiM), 48149, Muenster, Germany.
| |
Collapse
|
30
|
7T Proton Magnetic Resonance Spectroscopy of Gamma-Aminobutyric Acid, Glutamate, and Glutamine Reveals Altered Concentrations in Patients With Schizophrenia and Healthy Siblings. Biol Psychiatry 2017; 81:525-535. [PMID: 27316853 DOI: 10.1016/j.biopsych.2016.04.007] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Revised: 04/08/2016] [Accepted: 04/11/2016] [Indexed: 12/21/2022]
Abstract
BACKGROUND The N-methyl-D-aspartate receptor hypofunction model of schizophrenia predicts dysfunction in both glutamatergic and gamma-aminobutyric acidergic (GABAergic) transmission. We addressed this hypothesis by measuring GABA, glutamate, glutamine, and the sum of glutamine plus glutamate concentrations in vivo in patients with schizophrenia using proton magnetic resonance spectroscopy at 7T, which allows separation of metabolites that would otherwise overlap at lower field strengths. In addition, we investigated whether altered levels of GABA, glutamate, glutamine, and the sum of glutamine plus glutamate reflect genetic vulnerability to schizophrenia by including healthy first-degree relatives. METHODS Proton magnetic resonance spectroscopy at 7T was performed in 21 patients with chronic schizophrenia who were taking medication, 23 healthy first-degree relatives of patients with schizophrenia, and 24 healthy nonrelatives. Glutamate, glutamine, and GABA were measured cortically and subcortically in bilateral basal ganglia and occipital cortex. RESULTS Patients with schizophrenia had reduced cortical GABA compared with healthy relatives and the combined sample of healthy relatives and healthy nonrelatives, suggesting that altered GABAergic systems in schizophrenia are associated with either disease state or medication effects. Reduced cortical glutamine relative to healthy control subjects was observed in patients with schizophrenia and the combined sample of healthy relatives and patients with schizophrenia, suggesting that altered glutamatergic metabolite levels are associated with illness liability. No group differences were found in the basal ganglia. CONCLUSIONS Taken together, these findings are consistent with alterations in GABAergic and glutamatergic systems in patients with schizophrenia and provide novel insights into these systems in healthy relatives.
Collapse
|
31
|
Piyabhan P, Wannasiri S, Naowaboot J. Bacopa monnieri(Brahmi) improved novel object recognition task and increased cerebral vesicular glutamate transporter type 3 in sub-chronic phencyclidine rat model of schizophrenia. Clin Exp Pharmacol Physiol 2016; 43:1234-1242. [DOI: 10.1111/1440-1681.12658] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Revised: 08/01/2016] [Accepted: 08/17/2016] [Indexed: 12/12/2022]
Affiliation(s)
- Pritsana Piyabhan
- Division of Physiology; Department of Preclinical Science; Faculty of Medicine; Thammasat University; Klongluang Pathumthani Thailand
| | - Supaporn Wannasiri
- Division of Physiology; Department of Preclinical Science; Faculty of Medicine; Thammasat University; Klongluang Pathumthani Thailand
| | - Jarinyaporn Naowaboot
- Division of Pharmacology; Department of Preclinical Science; Faculty of Medicine; Thammasat University; Klongluang Pathumthani Thailand
| |
Collapse
|
32
|
O'Tuathaigh CMP, Desbonnet L, Moran PM, Kirby BP, Waddington JL. Molecular genetic models related to schizophrenia and psychotic illness: heuristics and challenges. Curr Top Behav Neurosci 2016; 7:87-119. [PMID: 21298380 DOI: 10.1007/7854_2010_111] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Schizophrenia is a heritable disorder that may involve several common genes of small effect and/or rare copy number variation, with phenotypic heterogeneity across patients. Furthermore, any boundaries vis-à-vis other psychotic disorders are far from clear. Consequently, identification of informative animal models for this disorder, which typically relate to pharmacological and putative pathophysiological processes of uncertain validity, faces considerable challenges. In juxtaposition, the majority of mutant models for schizophrenia relate to the functional roles of a diverse set of genes associated with risk for the disorder or with such putative pathophysiological processes. This chapter seeks to outline the evidence from phenotypic studies in mutant models related to schizophrenia. These have commonly assessed the degree to which mutation of a schizophrenia-related gene is associated with the expression of several aspects of the schizophrenia phenotype or more circumscribed, schizophrenia-related endophenotypes; typically, they place specific emphasis on positive and negative symptoms and cognitive deficits, and extend to structural and other pathological features. We first consider the primary technological approaches to the generation of such mutants, to include their relative merits and demerits, and then highlight the diverse phenotypic approaches that have been developed for their assessment. The chapter then considers the application of mutant phenotypes to study pathobiological and pharmacological mechanisms thought to be relevant for schizophrenia, particularly in terms of dopaminergic and glutamatergic dysfunction, and to an increasing range of candidate susceptibility genes and copy number variants. Finally, we discuss several pertinent issues and challenges within the field which relate to both phenotypic evaluation and a growing appreciation of the functional genomics of schizophrenia and the involvement of gene × environment interactions.
Collapse
Affiliation(s)
- Colm M P O'Tuathaigh
- Molecular and Cellular Therapeutics, Royal College of Surgeons in Ireland, 123 St. Stephen's Green, Dublin 2, Ireland,
| | | | | | | | | |
Collapse
|
33
|
Brandt AS, Unschuld PG, Pradhan S, Lim IAL, Churchill G, Harris AD, Hua J, Barker PB, Ross CA, van Zijl PCM, Edden RAE, Margolis RL. Age-related changes in anterior cingulate cortex glutamate in schizophrenia: A (1)H MRS Study at 7 Tesla. Schizophr Res 2016; 172:101-5. [PMID: 26925800 PMCID: PMC4821673 DOI: 10.1016/j.schres.2016.02.017] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/25/2015] [Revised: 02/08/2016] [Accepted: 02/10/2016] [Indexed: 12/27/2022]
Abstract
The extent of age-related changes in glutamate and other neurometabolites in the anterior cingulate cortex (ACC) in individuals with schizophrenia remain unclear. Magnetic resonance spectroscopy (MRS) at 7 T, which yields precise measurements of various metabolites and can distinguish glutamate from glutamine, was used to determine levels of ACC glutamate and other metabolites in 24 individuals with schizophrenia and 24 matched controls. Multiple regression analysis revealed that ACC glutamate decreased with age in patients but not controls. No changes were detected in levels of glutamine, N-acetylaspartate, N-acetylaspartylglutamic acid, myo-inositol, GABA, glutathione, total creatine, and total choline. These results suggest that age may be an important modifier of ACC glutamate in schizophrenia.
Collapse
Affiliation(s)
- Allison S Brandt
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Paul G Unschuld
- Laboratory for Aging Neuroscience and Neuroimaging, Division of Psychiatry Research and Psychogeriatric Medicine, University of Zürich, Zurich, Switzerland
| | - Subechhya Pradhan
- Russell H. Morgan Department of Radiology and Radiological Science, Division of MR Research, Johns Hopkins University School of Medicine, Baltimore, MD, USA; F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, United States
| | - Issel Anne L Lim
- Russell H. Morgan Department of Radiology and Radiological Science, Division of MR Research, Johns Hopkins University School of Medicine, Baltimore, MD, USA; F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, United States
| | - Gregory Churchill
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Ashley D Harris
- Russell H. Morgan Department of Radiology and Radiological Science, Division of MR Research, Johns Hopkins University School of Medicine, Baltimore, MD, USA; F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, United States
| | - Jun Hua
- Russell H. Morgan Department of Radiology and Radiological Science, Division of MR Research, Johns Hopkins University School of Medicine, Baltimore, MD, USA; F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, United States
| | - Peter B Barker
- Russell H. Morgan Department of Radiology and Radiological Science, Division of MR Research, Johns Hopkins University School of Medicine, Baltimore, MD, USA; F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, United States
| | - Christopher A Ross
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of Neurology and Program in Cellular and Molecular Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Departments of Pharmacology and Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Peter C M van Zijl
- Russell H. Morgan Department of Radiology and Radiological Science, Division of MR Research, Johns Hopkins University School of Medicine, Baltimore, MD, USA; F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, United States
| | - Richard A E Edden
- Russell H. Morgan Department of Radiology and Radiological Science, Division of MR Research, Johns Hopkins University School of Medicine, Baltimore, MD, USA; F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, United States
| | - Russell L Margolis
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of Neurology and Program in Cellular and Molecular Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
| |
Collapse
|
34
|
Scott MR, Rubio MD, Haroutunian V, Meador-Woodruff JH. Protein Expression of Proteasome Subunits in Elderly Patients with Schizophrenia. Neuropsychopharmacology 2016; 41:896-905. [PMID: 26202105 PMCID: PMC4707836 DOI: 10.1038/npp.2015.219] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Revised: 06/12/2015] [Accepted: 06/22/2015] [Indexed: 12/27/2022]
Abstract
The ubiquitin proteasome system (UPS) is a major regulator of protein processing, trafficking, and degradation. While protein ubiquitination is utilized for many cellular processes, one major function of this system is to target proteins to the proteasome for degradation. In schizophrenia, studies have found UPS transcript abnormalities in both blood and brain, and we have previously reported decreased protein expression of ubiquitin-associated proteins in brain. To test whether the proteasome is similarly dysregulated, we measured the protein expression of proteasome catalytic subunits as well as essential subunits from proteasome regulatory complexes in 14 pair-matched schizophrenia and comparison subjects in superior temporal cortex. We found decreased expression of Rpt1, Rpt3, and Rpt6, subunits of the 19S regulatory particle essential for ubiquitin-dependent degradation by the proteasome. Additionally, the α subunit of the 11S αβ regulatory particle, which enhances proteasomal degradation of small peptides and unfolded proteins, was also decreased. Haloperidol-treated rats did not have altered expression of these subunits, suggesting the changes we observed in schizophrenia are likely not due to chronic antipsychotic treatment. Interestingly, expression of the catalytic subunits of both the standard and immunoproteasome were unchanged, suggesting the abnormalities we observed may be specific to the complexed state of the proteasome. Aging has significant effects on the proteasome, and several subunits (20S β2, Rpn10, Rpn13, 11Sβ, and 11Sγ) were significantly correlated with subject age. These data provide further evidence of dysfunction of the ubiquitin-proteasome system in schizophrenia, and suggest that altered proteasome activity may be associated with the pathophysiology of this illness.
Collapse
Affiliation(s)
- Madeline R Scott
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Maria D Rubio
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Vahram Haroutunian
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - James H Meador-Woodruff
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham, Birmingham, AL, USA
| |
Collapse
|
35
|
Lisek M, Boczek T, Ferenc B, Zylinska L. Regional brain dysregulation of Ca(2+)-handling systems in ketamine-induced rat model of experimental psychosis. Cell Tissue Res 2015; 363:609-20. [PMID: 26685921 PMCID: PMC4761010 DOI: 10.1007/s00441-015-2332-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Accepted: 11/11/2015] [Indexed: 01/21/2023]
Abstract
Chronic N-methyl-D-aspartate receptor (NMDAR) antagonist treatment can provide valuable neurochemical and neuroanatomical models of experimental psychosis. One such antagonist, ketamine, with its short half-time and well-documented psychotomimetic action, has cognitive effects resembling various aspects of schizophrenia-like symptoms. In order to obtain insights into possible relationships between Ca(2+) homeostasis and schizophrenia-related symptoms, we investigate the effects of chronic ketamine administration on intracellular Ca(2+) levels in various brain regions and on the expression level of key members of the neuronal Ca(2+)-handling system in rats. We show increased intracellular [Ca(2+)] in all of the examined brain regions following ketamine treatment but an altered cytosolic Ca(2+) level correlated with hyperlocomotor activity was only established for the cortex and striatum. Our findings also suggest that an imbalance in the expression between the calcium "on" and "off" systems contributes to the deregulation of brain Ca(2+) homeostasis in our ketamine-induced model of experimental psychosis. Identification of the genes whose expression is affected by ketamine treatment indicates their involvement as putative etiological factors in schizophrenia.
Collapse
Affiliation(s)
- Malwina Lisek
- Department of Molecular Neurochemistry, Faculty of Health Sciences, Medical University of Lodz, 6/8 Mazowiecka Street, 92215, Lodz, Poland.
| | - Tomasz Boczek
- Department of Molecular Neurochemistry, Faculty of Health Sciences, Medical University of Lodz, 6/8 Mazowiecka Street, 92215, Lodz, Poland
| | - Bozena Ferenc
- Department of Molecular Neurochemistry, Faculty of Health Sciences, Medical University of Lodz, 6/8 Mazowiecka Street, 92215, Lodz, Poland
| | - Ludmila Zylinska
- Department of Molecular Neurochemistry, Faculty of Health Sciences, Medical University of Lodz, 6/8 Mazowiecka Street, 92215, Lodz, Poland
| |
Collapse
|
36
|
McCollum LA, Roberts RC. Uncovering the role of the nucleus accumbens in schizophrenia: A postmortem analysis of tyrosine hydroxylase and vesicular glutamate transporters. Schizophr Res 2015; 169:369-373. [PMID: 26386900 PMCID: PMC4755276 DOI: 10.1016/j.schres.2015.08.041] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Revised: 08/26/2015] [Accepted: 08/31/2015] [Indexed: 10/23/2022]
Abstract
The nucleus accumbens (NAcc) is often implicated in schizophrenia (SZ) pathology, but with little evidence to support its role. This study examined postmortem human tissue to determine if abnormalities are present in the dopaminergic or glutamatergic systems in the NAcc in SZ. We compared the protein levels of tyrosine hydroxylase (TH) and vesicular glutamate transporters vGLUT1 and vGLUT2 in control (n=7) and schizophrenia (n=13) subjects using Western blot analysis. The SZ subjects were further divided by treatment status: SZ on-drug (SZ-ON, n=6) and SZ off-drug (SZ-OFF, n=7), to assess the effects of antipsychotic treatment. TH protein levels were similar between control and SZ subjects, and there was no difference between SZ-ON and SZ-OFF subjects. Protein levels of vGLUT1 were similar in control and SZ subjects, and there was no difference in vGLUT1 protein levels between SZ-ON and SZ-OFF subjects. In contrast, vGLUT2 protein levels were significantly elevated in the SZ group (25% increase). Protein levels of vGLUT2 did not differ between SZ-ON and SZ-OFF subjects. Similar levels of TH suggest the presynaptic DA pathway may be normal in the NAcc in SZ. The elevated vGLUT2 protein levels, but not vGLUT1, suggest the NAcc receives increased glutamatergic input in SZ, possibly from thalamic or other subcortical origins. The similarity between SZ-ON and SZ-OFF subjects suggests that the results are not caused by APD treatment. These findings provide further insight into the role of the NAcc in SZ.
Collapse
|
37
|
Pundir AS, Singh UA, Ahuja N, Makhija S, Dikshit PC, Radotra B, Kumar P, Shankar SK, Mahadevan A, Roy TS, Iyengar S. Growth and refinement of excitatory synapses in the human auditory cortex. Brain Struct Funct 2015; 221:3641-74. [PMID: 26438332 DOI: 10.1007/s00429-015-1124-6] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Accepted: 09/25/2015] [Indexed: 02/03/2023]
Abstract
We had earlier demonstrated a neurofilament-rich plexus of axons in the presumptive human auditory cortex during fetal development which became adult-like during infancy. To elucidate the origin of these axons, we studied the expression of the vesicular glutamate transporters (VGLUT) 1 and 2 in the human auditory cortex at different stages of development. While VGLUT-1 expression predominates in intrinsic and cortico-cortical synapses, VGLUT-2 expression predominates in thalamocortical synapses. Levels of VGLUT-2 mRNA were higher in the auditory cortex before birth compared to postnatal development. In contrast, levels of VGLUT-1 mRNA were low before birth and increased during postnatal development to peak during childhood and then began to decrease in adolescence. Both VGLUT-1 and VGLUT-2 proteins were present in the human auditory cortex as early as 15GW. Further, immunohistochemistry revealed that the supra- and infragranular layers were more immunoreactive for VGLUT-1 compared to that in Layer IV at 34GW and this pattern was maintained until adulthood. As for VGLUT-1 mRNA, VGLUT-1 synapses increased in density between prenatal development and childhood in the human auditory cortex after which they appeared to undergo attrition or pruning. The adult pattern of VGLUT-2 immunoreactivity (a dense band of VGLUT-2-positive terminals in Layer IV) also began to appear in the presumptive Heschl's gyrus at 34GW. The density of VGLUT-2-positive puncta in Layer IV increased between prenatal development and adolescence, followed by a decrease in adulthood, suggesting that thalamic axons which innervate the human auditory cortex undergo pruning comparatively late in development.
Collapse
Affiliation(s)
- Arvind Singh Pundir
- Division of Systems Neuroscience, National Brain Research Centre (Deemed University), NH-8, Manesar, Gurgaon, Haryana, 122051, India
| | - Utkarsha A Singh
- Division of Systems Neuroscience, National Brain Research Centre (Deemed University), NH-8, Manesar, Gurgaon, Haryana, 122051, India
| | - Nikhil Ahuja
- Division of Systems Neuroscience, National Brain Research Centre (Deemed University), NH-8, Manesar, Gurgaon, Haryana, 122051, India
| | - Sonal Makhija
- Division of Systems Neuroscience, National Brain Research Centre (Deemed University), NH-8, Manesar, Gurgaon, Haryana, 122051, India
| | - P C Dikshit
- Department of Forensic Medicine, Maulana Azad Medical College, Bahadur Shah Zafar Marg, New Delhi, 110002, India
| | - Bishan Radotra
- Department of Histopathology, Post Graduate Institute of Medical Education and Research, Sector-12, Chandigarh, 160012, India
| | - Praveen Kumar
- Department of Obstetrics and Gynecology, Base Hospital, Delhi Cantonment, Delhi, 110010, India
| | - S K Shankar
- Department of Neuropathology, National Institute of Mental Health and Allied Sciences, Hosur Road, Bangalore, 560029, India
| | - Anita Mahadevan
- Department of Neuropathology, National Institute of Mental Health and Allied Sciences, Hosur Road, Bangalore, 560029, India
| | - T S Roy
- Department of Anatomy, All India Institute of Medical Sciences, New Delhi, 110002, India
| | - Soumya Iyengar
- Division of Systems Neuroscience, National Brain Research Centre (Deemed University), NH-8, Manesar, Gurgaon, Haryana, 122051, India.
| |
Collapse
|
38
|
Roberts RC, Barksdale KA, Roche JK, Lahti AC. Decreased synaptic and mitochondrial density in the postmortem anterior cingulate cortex in schizophrenia. Schizophr Res 2015; 168:543-53. [PMID: 26210550 PMCID: PMC4591176 DOI: 10.1016/j.schres.2015.07.016] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Revised: 07/07/2015] [Accepted: 07/10/2015] [Indexed: 12/24/2022]
Abstract
Schizophrenia (SZ) is a mental illness characterized by psychosis, negative symptoms, and cognitive deficits. The anterior cingulate cortex (ACC), a structurally and functionally diverse region, is one of several brain regions that is abnormal in SZ. The present study compared synaptic organization and mitochondrial number and morphology in postmortem ACC in SZ versus normal control (NC). Total synaptic density in the combined ACC was decreased in SZ, to 72% of normal controls (NCs), due to selective decreases in axospinous synapses, both asymmetric (excitatory) and symmetric (inhibitory). These changes were present in layers 3 and 5/6. The density of mitochondria in all axon terminals combined in SZ was decreased to 64% of NC. In layer 3, mitochondrial density was decreased only in terminals forming asymmetric synapses with spines, while in layers 5/6 mitochondrial density was decreased in terminals forming symmetric synapses with spines and dendrites. The proportion of terminals making symmetric synapses that contained mitochondria was significantly lower in SZ than in NCs, especially for symmetric axospinous synapses. The number of mitochondria per neuronal somata was decreased in the ACC in SZ compared to NCs; this finding was present in layers 5-6. The size of mitochondria in neuronal somata and throughout the neuropil was similar in SZ and NCs. Our results, though preliminary, are well supported by the literature, and support an anatomical substrate for some of the altered executive functions found in SZ.
Collapse
Affiliation(s)
- R C Roberts
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama, Birmingham, AL 35294, United States.
| | - K A Barksdale
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama, Birmingham, AL 35294, United States
| | - J K Roche
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama, Birmingham, AL 35294, United States
| | - A C Lahti
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama, Birmingham, AL 35294, United States
| |
Collapse
|
39
|
Bristow GC, Bostrom JA, Haroutunian V, Sodhi MS. Sex differences in GABAergic gene expression occur in the anterior cingulate cortex in schizophrenia. Schizophr Res 2015; 167:57-63. [PMID: 25660468 PMCID: PMC4524801 DOI: 10.1016/j.schres.2015.01.025] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2014] [Revised: 01/15/2015] [Accepted: 01/17/2015] [Indexed: 01/30/2023]
Abstract
GABAergic dysfunction has been strongly implicated in the pathophysiology of schizophrenia. In this study, we analyzed the expression levels of several GABAergic genes in the anterior cingulate cortex (ACC) of postmortem subjects with schizophrenia (n=21) and a comparison group of individuals without a history of psychiatric illness (n=18). Our analyses revealed a significant sex by diagnosis effect, along with significant differences in GABAergic gene expression based on medication status. Analyses revealed that in male groups, the expression of GABAergic genes was generally lower in schizophrenia cases compared to the controls, with significantly lower expression levels of GABA-Aα5, GABA-Aβ1, and GABA-Aε. In females, the expression of GABAergic genes was higher in the schizophrenia cases, with significantly higher expression of the GABA-Aβ1 and GAD67 genes. Analysis of the effect of medication in the schizophrenia subjects revealed significantly higher expression of GABA-Aα1-3, GABA-Aβ2, GABA-Aγ2, and GAD67 in the medicated group compared to the unmedicated group. These data show that sex differences in the expression of GABAergic genes occur in the ACC in schizophrenia. Therefore, our data support previous findings of GABAergic dysfunction in schizophrenia and emphasize the importance of considering sex in analyses of the pathophysiology of schizophrenia. Sex differences in the GABAergic regulation of ACC function may contribute to the differences observed in the symptoms of male and female patients with schizophrenia. In addition, our findings indicate that antipsychotic medications may alter GABAergic signaling in the ACC, supporting the potential of GABAergic targets for the development of novel antipsychotic medication.
Collapse
Affiliation(s)
- Greg C. Bristow
- Department of Pharmacy Practice and Center for Pharmaceutical Biotechnology, College of Pharmacy, University of Illinois at Chicago, Chicago IL 60607, USA.,Corresponding author: Dr. Greg Bristow, Department of Pharmacy Practice, University of Illinois at Chicago, 900 S. Ashland Ave., MC870, Chicago IL 60607-4067, USA. Tel: +1-312-996-1413, Fax: +1-312-413-9303,
| | - John A. Bostrom
- Department of Pharmacy Practice and Center for Pharmaceutical Biotechnology, College of Pharmacy, University of Illinois at Chicago, Chicago IL 60607, USA
| | - Vahram Haroutunian
- Department of Psychiatry, Mount Sinai School of Medicine, New York, NY, USA
| | - Monsheel S. Sodhi
- Department of Pharmacy Practice and Center for Pharmaceutical Biotechnology, College of Pharmacy, University of Illinois at Chicago, Chicago IL 60607, USA.,Department of Psychiatry, University of Illinois at Chicago, Chicago, IL 60612, USA
| |
Collapse
|
40
|
Sullivan CR, Funk AJ, Shan D, Haroutunian V, McCullumsmith RE. Decreased chloride channel expression in the dorsolateral prefrontal cortex in schizophrenia. PLoS One 2015; 10:e0123158. [PMID: 25826365 PMCID: PMC4380350 DOI: 10.1371/journal.pone.0123158] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2014] [Accepted: 02/17/2015] [Indexed: 12/17/2022] Open
Abstract
Alterations in GABAergic neurotransmission are implicated in several psychiatric illnesses, including schizophrenia. The Na-K-Cl and K-Cl cotransporters regulate intracellular chloride levels. Abnormalities in cotransporter expression levels could shift the chloride electrochemical gradient and impair GABAergic transmission. In this study, we performed Western blot analysis to investigate whether the Na-K-Cl and K-Cl cotransporter protein is abnormally expressed in the dorsal lateral prefrontal cortex and the anterior cingulate cortex in patients with schizophrenia versus a control group. We found decreased K-Cl cotransporter protein expression in the dorsal lateral prefrontal cortex, but not the anterior cingulate cortex, in subjects with schizophrenia, supporting the hypothesis of region level abnormal GABAergic function in the pathophysiology of schizophrenia. Subjects with schizophrenia off antipsychotic medication at the time of death had decreased K-Cl cotransporter protein expression compared to both normal controls and subjects with schizophrenia on antipsychotics. Our results provide evidence for KCC2 protein abnormalities in schizophrenia and suggest that antipsychotic medications might reverse deficits of this protein in the illness.
Collapse
Affiliation(s)
- Courtney R. Sullivan
- University of Cincinnati College of Medicine, Neuroscience Graduate Program, Cincinnati, Ohio, United States of America
- Department of Psychiatry and Behavioral Neuroscience, University of Cincinnati, Cincinnati, Ohio, United States of America
| | - Adam J. Funk
- Department of Psychiatry and Behavioral Neuroscience, University of Cincinnati, Cincinnati, Ohio, United States of America
| | - Dan Shan
- Department of Nephrology, University of Alabama Birmingham, Birmingham, Alabama, United States of America
| | - Vahram Haroutunian
- Department of Psychiatry, Mount Sinai School of Medicine, New York, New York, United States of America
- James J Peters Veterans Affairs Medical Center, New York, New York, United States of America
| | - Robert E. McCullumsmith
- Department of Psychiatry and Behavioral Neuroscience, University of Cincinnati, Cincinnati, Ohio, United States of America
- * E-mail:
| |
Collapse
|
41
|
Vigneault É, Poirel O, Riad M, Prud'homme J, Dumas S, Turecki G, Fasano C, Mechawar N, El Mestikawy S. Distribution of vesicular glutamate transporters in the human brain. Front Neuroanat 2015; 9:23. [PMID: 25798091 PMCID: PMC4350397 DOI: 10.3389/fnana.2015.00023] [Citation(s) in RCA: 76] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Accepted: 02/12/2015] [Indexed: 11/19/2022] Open
Abstract
Glutamate is the major excitatory transmitter in the brain. Vesicular glutamate transporters (VGLUT1-3) are responsible for uploading glutamate into synaptic vesicles. VGLUT1 and VGLUT2 are considered as specific markers of canonical glutamatergic neurons, while VGLUT3 is found in neurons previously shown to use other neurotransmitters than glutamate. Although there exists a rich literature on the localization of these glutamatergic markers in the rodent brain, little is currently known about the distribution of VGLUT1-3 in the human brain. In the present study, using subtype specific probes and antisera, we examined the localization of the three vesicular glutamate transporters in the human brain by in situ hybridization, immunoautoradiography and immunohistochemistry. We found that the VGLUT1 transcript was highly expressed in the cerebral cortex, hippocampus and cerebellum, whereas VGLUT2 mRNA was mainly found in the thalamus and brainstem. VGLUT3 mRNA was localized in scarce neurons within the cerebral cortex, hippocampus, striatum and raphe nuclei. Following immunoautoradiographic labeling, intense VGLUT1- and VGLUT2-immunoreactivities were observed in all regions investigated (cerebral cortex, hippocampus, caudate-putamen, cerebellum, thalamus, amygdala, substantia nigra, raphe) while VGLUT3 was absent from the thalamus and cerebellum. This extensive mapping of VGLUT1-3 in human brain reveals distributions that correspond for the most part to those previously described in rodent brains.
Collapse
Affiliation(s)
- Érika Vigneault
- Department of Psychiatry, Douglas Mental Health University Institute, McGill University Montreal, QC, Canada
| | - Odile Poirel
- Institut National de la Santé et de la Recherche Médicale, UMR-S 1130, Neuroscience Paris Seine Paris, France ; Centre National de la Recherche Scientifique UMR 8246, Neuroscience Paris Seine Paris, France ; Sorbonne University, Université Pierre et Marie Curie Paris 06, UM119, Neuroscience Paris Seine Paris, France
| | - Mustapha Riad
- Department of Psychiatry, Douglas Mental Health University Institute, McGill University Montreal, QC, Canada
| | - Josée Prud'homme
- Department of Psychiatry, Douglas Mental Health University Institute, McGill University Montreal, QC, Canada
| | | | - Gustavo Turecki
- Department of Psychiatry, Douglas Mental Health University Institute, McGill University Montreal, QC, Canada
| | - Caroline Fasano
- Department of Psychiatry, Douglas Mental Health University Institute, McGill University Montreal, QC, Canada
| | - Naguib Mechawar
- Department of Psychiatry, Douglas Mental Health University Institute, McGill University Montreal, QC, Canada
| | - Salah El Mestikawy
- Department of Psychiatry, Douglas Mental Health University Institute, McGill University Montreal, QC, Canada ; Institut National de la Santé et de la Recherche Médicale, UMR-S 1130, Neuroscience Paris Seine Paris, France ; Centre National de la Recherche Scientifique UMR 8246, Neuroscience Paris Seine Paris, France ; Sorbonne University, Université Pierre et Marie Curie Paris 06, UM119, Neuroscience Paris Seine Paris, France
| |
Collapse
|
42
|
Antipsychotic treatment modulates glutamate transport and NMDA receptor expression. Eur Arch Psychiatry Clin Neurosci 2014; 264 Suppl 1:S67-82. [PMID: 25214389 DOI: 10.1007/s00406-014-0534-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2014] [Accepted: 09/02/2014] [Indexed: 12/21/2022]
Abstract
Schizophrenia patients often suffer from treatment-resistant cognitive and negative symptoms, both of which are influenced by glutamate neurotransmission. Innovative therapeutic strategies such as agonists at metabotropic glutamate receptors or glycin reuptake inhibitors try to modulate the brain's glutamate network. Interactions of amino acids with monoamines have been described on several levels, and first- and second-generation antipsychotic agents (FGAs, SGAs) are known to exert modulatory effects on the glutamatergic system. This review summarizes the current knowledge on effects of FGAs and SGAs on glutamate transport and receptor expression derived from pharmacological studies. Such studies serve as a control for molecular findings in schizophrenia brain tissue and are clinically relevant. Moreover, they may validate animal models for psychosis, foster basic research on antipsychotic substances and finally lead to a better understanding of how monoaminergic and amino acid neurotransmissions are intertwined. In the light of these results, important differences dependent on antipsychotic substances, dosage and duration of treatment became obvious. While some post-mortem findings might be confounded with multifold drug effects, others are unlikely to be influenced by antipsychotic treatment and could represent important markers of schizophrenia pathophysiology. In similarity to the convergence of toxic and psychotomimetic effects of dopaminergic, serotonergic and anti-glutamatergic substances, the therapeutic mechanisms of SGAs might merge on a yet to be defined molecular level. In particular, serotonergic effects of SGAs, such as an agonism at 5HT1A receptors, represent important targets for further clinical research.
Collapse
|
43
|
Hu W, MacDonald ML, Elswick DE, Sweet RA. The glutamate hypothesis of schizophrenia: evidence from human brain tissue studies. Ann N Y Acad Sci 2014; 1338:38-57. [PMID: 25315318 DOI: 10.1111/nyas.12547] [Citation(s) in RCA: 169] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
A number of studies have indicated that antagonists of the N-methyl-d-aspartate subtypes of glutamate receptors can cause schizophrenia-like symptoms in healthy individuals and exacerbate symptoms in individuals with schizophrenia. These findings have led to the glutamate hypothesis of schizophrenia. Here we review the evidence for this hypothesis in postmortem studies of brain tissue from individuals affected by schizophrenia, summarizing studies of glutamate neuron morphology, of expression of glutamate receptors and transporters, and of the synthesizing and metabolizing enzymes for glutamate and its co-agonists. We found consistent evidence of morphological alterations of dendrites of glutamatergic neurons in the cerebral cortex of subjects with schizophrenia and of reduced levels of the axon bouton marker synaptophysin. There were no consistent alterations of mRNA expression of glutamate receptors, although there has been limited study of the corresponding proteins. Studies of the glutamate metabolic pathway have been limited, although there is some evidence that excitatory amino acid transporter-2, glutamine synthetase, and glutaminase have altered expression in schizophrenia. Future studies would benefit from additional direct examination of glutamatergic proteins. Further advances, such as selective testing of synaptic microdomains, cortical layers, and neuronal subtypes, may also be required to elucidate the nature of glutamate signaling impairments in schizophrenia.
Collapse
Affiliation(s)
- Wei Hu
- Department of Behavioral Medicine and Psychiatry, West Virginia University Health Sciences Center, Morgantown, West Virginia
| | | | | | | |
Collapse
|
44
|
Funk AJ, Haroutunian V, Meador-Woodruff JH, McCullumsmith RE. Increased G protein-coupled receptor kinase (GRK) expression in the anterior cingulate cortex in schizophrenia. Schizophr Res 2014; 159:130-5. [PMID: 25153362 PMCID: PMC4177355 DOI: 10.1016/j.schres.2014.07.040] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2014] [Revised: 07/18/2014] [Accepted: 07/20/2014] [Indexed: 01/11/2023]
Abstract
BACKGROUND Current pharmacological treatments for schizophrenia target G protein-coupled receptors (GPCRs), including dopamine receptors. Ligand-bound GPCRs are regulated by a family of G protein-coupled receptor kinases (GRKs), members of which uncouple the receptor from heterotrimeric G proteins, desensitize the receptor, and induce receptor internalization via the arrestin family of scaffolding and signaling molecules. GRKs initiate the activation of downstream signaling pathways, can regulate receptors and signaling molecules independent of GPCR phosphorylation, and modulate epigenetic regulators like histone deacetylases (HDACs). We hypothesize that the expression of GRK proteins is altered in schizophrenia, consistent with previous findings of alterations upstream and downstream from this family of molecules that facilitate intracellular signaling processes. METHODS In this study, we measured protein expression via Western blot analysis for GRKs 2, 3, 5, and 6 in the anterior cingulate cortex of patients with schizophrenia (n=36) and a comparison group (n=33). To control for antipsychotic treatment, we measured these same targets in haloperidol-treated vs. untreated rats (n=10 for both). RESULTS We found increased levels of GRK5 in schizophrenia. No changes were detected in GRK protein expression in rats treated with haloperidol decanoate for 9 months. CONCLUSION These data suggest that increased GRK5 expression may contribute to the pathophysiology of schizophrenia via abnormal regulation of the cytoskeleton, endocytosis, signaling, GPCRs, and histone modification.
Collapse
Affiliation(s)
- Adam J. Funk
- Department of Psychiatry and Behavioral Neuroscience, University of Cincinnati, CARE 5830, 231 Albert Sabin Way, Cincinnati, OH 45267-0583
| | - Vahram Haroutunian
- Department of Psychiatry, Mount Sinai School of Medicine, One Gustave L. Levy Place, Box 1230, New York, NY 10029
| | - James H. Meador-Woodruff
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama Birmingham, SC 560, 1530 3 Avenue South, Birmingham, AL 35294,Evelyn F. McKnight Brain Institute, University of Alabama Birmingham, Shelby 911, 1530 3 Avenue South, Birmingham, AL 35294
| | - Robert E. McCullumsmith
- Department of Psychiatry and Behavioral Neuroscience, University of Cincinnati, CARE 5830, 231 Albert Sabin Way, Cincinnati, OH 45267-0583
| |
Collapse
|
45
|
Synaptic proteins in the postmortem anterior cingulate cortex in schizophrenia: relationship to treatment and treatment response. Neuropsychopharmacology 2014; 39:2095-103. [PMID: 24603856 PMCID: PMC4104326 DOI: 10.1038/npp.2014.57] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Revised: 02/14/2014] [Accepted: 03/04/2014] [Indexed: 12/27/2022]
Abstract
The anterior cingulate cortex (ACC) is one of several brain regions that are abnormal in schizophrenia (SZ). Here we compared markers of synapse and mitochondrial function using western blots of postmortem ACC in: 1) normal controls (NCs, n=13) vs subjects with SZ (n=25); NC, treatment-resistant SZ, and treatment-responsive SZ; and 3) NC and SZ treated with typical or atypical antipsychotic drugs (APDs). Protein levels of synaptophysin, mitofusin-2, vGLUT1, and calcineurin did not differ between the NC and SZ group as a whole, or the NCs vs the SZ group divided by treatment response or type of APDs. In several cases, the levels of vGLUT1 were minuscule or absent. The proportion of NCs lacking vGLUT1 was significantly less than that of the SZ groups. There were several positive correlations across all subjects between: 1) synaptophysin and vGLUT1; 2) synaptophysin and calcineurin; 3) synaptophysin and mitofusin; and 4) calcineurin and mitofusin. Synaptophysin and calcineurin were positively correlated in responders, and this correlation was significantly stronger than that in treatment-resistant SZ subjects or in NCs. Synaptophysin and calcineurin were positively correlated in SZ patients on atypical APDs; this correlation was significantly stronger than that in SZ patients on typical APDs or in NCs. Mitofusin-2 and calcineurin were positively correlated in SZ patients on atypical APDs and in NCs; this correlation was stronger in SZ patients on atypical rather than typical APDs or in NCs. The correlation between these proteins, which have roles in synaptic vesicle cycling, glutamate transmission, mitochondrial fusion, and calcium buffering, is complex and was differentially regulated among the groups.
Collapse
|
46
|
Inhibition of vesicular glutamate transporters contributes to attenuate methamphetamine-induced conditioned place preference in rats. Behav Brain Res 2014; 267:1-5. [DOI: 10.1016/j.bbr.2014.02.047] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2013] [Revised: 02/19/2014] [Accepted: 02/22/2014] [Indexed: 11/23/2022]
|
47
|
King MV, Kurian N, Qin S, Papadopoulou N, Westerink BHC, Cremers TI, Epping-Jordan MP, Le Poul E, Ray DE, Fone KCF, Kendall DA, Marsden CA, Sharp TV. Lentiviral delivery of a vesicular glutamate transporter 1 (VGLUT1)-targeting short hairpin RNA vector into the mouse hippocampus impairs cognition. Neuropsychopharmacology 2014; 39:464-76. [PMID: 24037344 PMCID: PMC3870793 DOI: 10.1038/npp.2013.220] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/28/2013] [Revised: 08/07/2013] [Accepted: 08/08/2013] [Indexed: 01/28/2023]
Abstract
Glutamate is the principle excitatory neurotransmitter in the mammalian brain, and dysregulation of glutamatergic neurotransmission is implicated in the pathophysiology of several psychiatric and neurological diseases. This study utilized novel lentiviral short hairpin RNA (shRNA) vectors to target expression of the vesicular glutamate transporter 1 (VGLUT1) following injection into the dorsal hippocampus of adult mice, as partial reductions in VGLUT1 expression should attenuate glutamatergic signaling and similar reductions have been reported in schizophrenia. The VGLUT1-targeting vector attenuated tonic glutamate release in the dorsal hippocampus without affecting GABA, and selectively impaired novel object discrimination (NOD) and retention (but not acquisition) in the Morris water maze, without influencing contextual fear-motivated learning or causing any adverse locomotor or central immune effects. This pattern of cognitive impairment is consistent with the accumulating evidence for functional differentiation along the dorsoventral axis of the hippocampus, and supports the involvement of dorsal hippocampal glutamatergic neurotransmission in both spatial and nonspatial memory. Future use of this nonpharmacological VGLUT1 knockdown mouse model could improve our understanding of glutamatergic neurobiology and aid assessment of novel therapies for cognitive deficits such as those seen in schizophrenia.
Collapse
Affiliation(s)
- Madeleine V King
- School of Biomedical Sciences, University of Nottingham Medical School, Queen's Medical Centre, Nottingham, UK
| | - Nisha Kurian
- School of Biomedical Sciences, University of Nottingham Medical School, Queen's Medical Centre, Nottingham, UK
| | - Si Qin
- Department of Biomonitoring and Sensoring, Groningen Research Institute of Pharmacy (GRIP), University of Groningen, Groningen, The Netherlands
- Brains On-Line BV, Groningen, The Netherlands
| | - Nektaria Papadopoulou
- School of Biomedical Sciences, University of Nottingham Medical School, Queen's Medical Centre, Nottingham, UK
| | - Ben HC Westerink
- Department of Biomonitoring and Sensoring, Groningen Research Institute of Pharmacy (GRIP), University of Groningen, Groningen, The Netherlands
- Brains On-Line BV, Groningen, The Netherlands
| | - Thomas I Cremers
- Department of Biomonitoring and Sensoring, Groningen Research Institute of Pharmacy (GRIP), University of Groningen, Groningen, The Netherlands
- Brains On-Line BV, Groningen, The Netherlands
| | | | | | - David E Ray
- School of Biomedical Sciences, University of Nottingham Medical School, Queen's Medical Centre, Nottingham, UK
| | - Kevin CF Fone
- School of Biomedical Sciences, University of Nottingham Medical School, Queen's Medical Centre, Nottingham, UK
| | - David A Kendall
- School of Biomedical Sciences, University of Nottingham Medical School, Queen's Medical Centre, Nottingham, UK
| | - Charles A Marsden
- School of Biomedical Sciences, University of Nottingham Medical School, Queen's Medical Centre, Nottingham, UK
| | - Tyson V Sharp
- School of Biomedical Sciences, University of Nottingham Medical School, Queen's Medical Centre, Nottingham, UK
| |
Collapse
|
48
|
McCullumsmith RE, Hammond JH, Shan D, Meador-Woodruff JH. Postmortem brain: an underutilized substrate for studying severe mental illness. Neuropsychopharmacology 2014; 39:65-87. [PMID: 24091486 PMCID: PMC3857666 DOI: 10.1038/npp.2013.239] [Citation(s) in RCA: 81] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2013] [Revised: 07/30/2013] [Accepted: 08/02/2013] [Indexed: 02/08/2023]
Abstract
We propose that postmortem tissue is an underutilized substrate that may be used to translate genetic and/or preclinical studies, particularly for neuropsychiatric illnesses with complex etiologies. Postmortem brain tissues from subjects with schizophrenia have been extensively studied, and thus serve as a useful vehicle for illustrating the challenges associated with this biological substrate. Schizophrenia is likely caused by a combination of genetic risk and environmental factors that combine to create a disease phenotype that is typically not apparent until late adolescence. The complexity of this illness creates challenges for hypothesis testing aimed at understanding the pathophysiology of the illness, as postmortem brain tissues collected from individuals with schizophrenia reflect neuroplastic changes from a lifetime of severe mental illness, as well as treatment with antipsychotic medications. While there are significant challenges with studying postmortem brain, such as the postmortem interval, it confers a translational element that is difficult to recapitulate in animal models. On the other hand, data derived from animal models typically provide specific mechanistic and behavioral measures that cannot be generated using human subjects. Convergence of these two approaches has led to important insights for understanding molecular deficits and their causes in this illness. In this review, we discuss the problem of schizophrenia, review the common challenges related to postmortem studies, discuss the application of biochemical approaches to this substrate, and present examples of postmortem schizophrenia studies that illustrate the role of the postmortem approach for generating important new leads for understanding the pathophysiology of severe mental illness.
Collapse
Affiliation(s)
| | - John H Hammond
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama-Birmingham, Birmingham, AL, USA
| | - Dan Shan
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama-Birmingham, Birmingham, AL, USA
| | - James H Meador-Woodruff
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama-Birmingham, Birmingham, AL, USA
| |
Collapse
|
49
|
A combined metabonomic and proteomic approach identifies frontal cortex changes in a chronic phencyclidine rat model in relation to human schizophrenia brain pathology. Neuropsychopharmacology 2013; 38:2532-44. [PMID: 23942359 PMCID: PMC3799075 DOI: 10.1038/npp.2013.160] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2013] [Revised: 06/03/2013] [Accepted: 06/14/2013] [Indexed: 01/30/2023]
Abstract
Current schizophrenia (SCZ) treatments fail to treat the broad range of manifestations associated with this devastating disorder. Thus, new translational models that reproduce the core pathological features are urgently needed to facilitate novel drug discovery efforts. Here, we report findings from the first comprehensive label-free liquid-mass spectrometry proteomic- and proton nuclear magnetic resonance-based metabonomic profiling of the rat frontal cortex after chronic phencyclidine (PCP) intervention, which induces SCZ-like symptoms. The findings were compared with results from a proteomic profiling of post-mortem prefrontal cortex from SCZ patients and with relevant findings in the literature. Through this approach, we identified proteomic alterations in glutamate-mediated Ca(2+) signaling (Ca(2+)/calmodulin-dependent protein kinase II, PPP3CA, and VISL1), mitochondrial function (GOT2 and PKLR), and cytoskeletal remodeling (ARP3). Metabonomic profiling revealed changes in the levels of glutamate, glutamine, glycine, pyruvate, and the Ca(2+) regulator taurine. Effects on similar pathways were also identified in the prefrontal cortex tissue from human SCZ subjects. The discovery of similar but not identical proteomic and metabonomic alterations in the chronic PCP rat model and human brain indicates that this model recapitulates only some of the molecular alterations of the disease. This knowledge may be helpful in understanding mechanisms underlying psychosis, which, in turn, can facilitate improved therapy and drug discovery for SCZ and other psychiatric diseases. Most importantly, these molecular findings suggest that the combined use of multiple models may be required for more effective translation to studies of human SCZ.
Collapse
|
50
|
Neale SA, Copeland CS, Salt TE. Effect of VGLUT inhibitors on glutamatergic synaptic transmission in the rodent hippocampus and prefrontal cortex. Neurochem Int 2013; 73:159-65. [PMID: 24121008 DOI: 10.1016/j.neuint.2013.10.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Revised: 09/30/2013] [Accepted: 10/02/2013] [Indexed: 01/23/2023]
Abstract
Vesicular glutamate transporters (VGLUTs) are known to be important in the uptake of glutamate into vesicles in the presynaptic terminal; thereby playing a role in synaptic function. VGLUT dysfunction has also been suggested in neurological and psychiatric disorders such as epilepsy and schizophrenia. A number of compounds have been identified as VGLUT inhibitors; however, little is known as to how these compounds affect synaptic transmission. We therefore investigated the effects of structurally unrelated VGLUT inhibitors on synaptic transmission in the rodent hippocampus and prefrontal cortex. In the CA1 and dentate gyrus regions of the in vitro slice preparation of mouse hippocampus, AMPA receptor-mediated field excitatory postsynaptic potentials (fEPSPs) were evoked in response to Schaffer collateral/commissural pathway stimulation. Application of the VGLUT inhibitors Rose Bengal (RB), Congo Red (CR) or Chicago Sky Blue 6B (CB) resulted in a concentration-related reduction of fEPSP amplitudes. RB (30μM) or CB (300μM) also depressed NMDA receptor-mediated responses in the CA1 region. The naturally occurring kynurenine Xanthurenic Acid (XA) is reported to be a VGLUT inhibitor. We found XA attenuated both AMPA and NMDA receptor-mediated synaptic transmission. The potency order of the VGLUT inhibitors was consistent with literature Ki values for VGLUT inhibition. Impaired glutamatergic neurotransmission is believed to contribute to schizophrenia, and VGLUTs have also been implicated in this disease. We therefore investigated the effect of VGLUT inhibition in the prefrontal cortex. Application of the VGLUT inhibitors RB or CB resulted in a concentration-dependent reduction in the amplitude of glutamate receptor-mediated fEPSPs recorded in layer V/VI in response to stimulation in the forceps minor. We conclude that VGLUT inhibitors can modulate glutamatergic synaptic transmission in the PFC and hippocampus. This could be important in the pathophysiology of nervous system disorders and might represent a target for developing novel pharmacological therapies.
Collapse
Affiliation(s)
- S A Neale
- Neurexpert Ltd., Kemp House, London EC1V 2NX, UK; UCL Institute of Ophthalmology, London EC1V 9EL, UK
| | - C S Copeland
- UCL Institute of Ophthalmology, London EC1V 9EL, UK
| | - T E Salt
- UCL Institute of Ophthalmology, London EC1V 9EL, UK.
| |
Collapse
|