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Singh S, Sutkus L, Li Z, Baker S, Bear J, Dilger RN, Miller DJ. Standardization of a silver stain to reveal mesoscale myelin in histological preparations of the mammalian brain. J Neurosci Methods 2024; 407:110139. [PMID: 38626852 DOI: 10.1016/j.jneumeth.2024.110139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2024] [Revised: 03/26/2024] [Accepted: 04/12/2024] [Indexed: 04/29/2024]
Abstract
BACKGROUND The brain is built of neurons supported by myelin, a fatty substance that improves cellular communication. Noninvasive magnetic resonance imaging (MRI) is now able to measure brain structure like myelin and requires histological validation. NEW METHOD Here we present work in small and large biomedical model mammals to standardize a silver impregnation method as a high-throughput histological myelin visualization procedure. Specifically, we built a new staining well plate to increase batch size, and then systematically varied the staining and clearing cycles to describe the staining response curve across taxa and conditions. We compared tissues fixed by immersion or perfusion, mounted versus free-floating, and cut as thicker or thinner slices, with two-weeks of post-fixation. RESULTS The staining response curves show optimal staining with a single exposure across taxa when incubation and clearing epochs are held to within 3-9 min. We show that clearing was slower in mounted vs free-floating tissue, and that staining was faster and caused fracturing earlier in thinner sliced and smaller volumes of tissue. COMPARISON WITH EXISTING METHODS We developed a batch processing approach to increase throughput while ensuring reproducibility and demonstrate the optimal conditions for fine myelinated fiber morphology visualization with short cycles (<9 minutes). CONCLUSIONS We present our optimized protocol to reveal mesoscale neuroanatomical myelin content in histology across mammals. This standard staining procedure will facilitate multiscale analyses of myelin content across development as well as in the presence of injury or disease.
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Affiliation(s)
- S Singh
- Department of Evolution, Ecology, and Behavior, at the University of Illinois at Urbana-Champaign, 505 South Goodwin Ave, Urbana, IL 61801, United States of America
| | - L Sutkus
- Neuroscience Program, at the University of Illinois at Urbana-Champaign, 505 South Goodwin Ave, Urbana, IL 61801, United States of America
| | - Z Li
- Neuroscience Program, at the University of Illinois at Urbana-Champaign, 505 South Goodwin Ave, Urbana, IL 61801, United States of America
| | - S Baker
- Machine Shop, at the University of Illinois at Urbana-Champaign, 505 South Goodwin Ave, Urbana, IL 61801, United States of America
| | - J Bear
- Machine Shop, at the University of Illinois at Urbana-Champaign, 505 South Goodwin Ave, Urbana, IL 61801, United States of America
| | - R N Dilger
- Department of Animal Sciences, at the University of Illinois at Urbana-Champaign, 505 South Goodwin Ave, Urbana, IL 61801, United States of America; Neuroscience Program, at the University of Illinois at Urbana-Champaign, 505 South Goodwin Ave, Urbana, IL 61801, United States of America; Beckman Institute for Advanced Science and Technology, at the University of Illinois at Urbana-Champaign, 505 South Goodwin Ave, Urbana, IL 61801, United States of America
| | - D J Miller
- Department of Evolution, Ecology, and Behavior, at the University of Illinois at Urbana-Champaign, 505 South Goodwin Ave, Urbana, IL 61801, United States of America; Neuroscience Program, at the University of Illinois at Urbana-Champaign, 505 South Goodwin Ave, Urbana, IL 61801, United States of America; Beckman Institute for Advanced Science and Technology, at the University of Illinois at Urbana-Champaign, 505 South Goodwin Ave, Urbana, IL 61801, United States of America.
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Zhu Y, Webster MJ, Walker AK, Massa P, Middleton FA, Weickert CS. Increased prefrontal cortical cells positive for macrophage/microglial marker CD163 along blood vessels characterizes a neuropathology of neuroinflammatory schizophrenia. Brain Behav Immun 2023; 111:46-60. [PMID: 36972743 DOI: 10.1016/j.bbi.2023.03.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 03/01/2023] [Accepted: 03/23/2023] [Indexed: 03/29/2023] Open
Abstract
Transcript levels of cytokines and SERPINA3 have been used to define a substantial subset (40%) of individuals with schizophrenia with elevated inflammation and worse neuropathology in the dorsolateral prefrontal cortex (DLPFC). In this study, we tested if inflammatory proteins are likewise related to high and low inflammatory states in the human DLFPC in people with schizophrenia and controls. Levels of inflammatory cytokines (IL6, IL1β, IL18, IL8) and a macrophage marker (CD163 protein) were measured in brains obtained from the National Institute of Mental Health (NIMH) (N = 92). First, we tested for diagnostic differences in protein levels overall, then we determined the percentage of individuals that could be defined as "high" inflammation using protein levels. IL-18 was the only cytokine to show increased expression in schizophrenia compared to controls overall. Interestingly, two-step recursive clustering analysis showed that IL6, IL18, and CD163 protein levels could be used as predictors of "high and low" inflammatory subgroups. By this model, a significantly greater proportion of schizophrenia cases (18/32; 56.25%; SCZ) were identified as belonging to the high inflammatory (HI) subgroup compared to control cases (18/60; 30%; CTRL) [χ2(1) = 6.038, p = 0.014]. When comparing across inflammatory subgroups, IL6, IL1β, IL18, IL8, and CD163 protein levels were elevated in both SCZ-HI and CTRL-HI compared to both low inflammatory subgroups (all p < 0.05). Surprisingly, TNFα levels were significantly decreased (-32.2%) in schizophrenia compared to controls (p < 0.001), and were most diminished in the SCZ-HI subgroup compared to both CTRL-LI and CTRL-HI subgroups (p < 0.05). Next, we asked if the anatomical distribution and density of CD163+ macrophages differed in those with schizophrenia and high inflammation status. Macrophages were localized to perivascular sites and found surrounding small, medium and large blood vessels in both gray matter and white matter, with macrophage density highest at the pial surface in all schizophrenia cases examined. A higher density of CD163+ macrophages, that were also larger and more darkly stained, was found in the SCZ-HI subgroup (+154% p < 0.05). We also confirmed the rare existence of parenchymal CD163+ macrophages in both high inflammation subgroups (schizophrenia and controls). Brain CD163+ cell density around blood vessels positively correlated with CD163 protein levels. In conclusion, we find a link between elevated interleukin cytokine protein levels, decreased TNFα protein levels, and elevated CD163+ macrophage densities especially along small blood vessels in those with neuroinflammatory schizophrenia.
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Affiliation(s)
- Yunting Zhu
- Department of Neuroscience & Physiology, Upstate Medical University, Syracuse, NY 13210, USA
| | | | - Adam K Walker
- School of Psychiatry, Faculty of Medicine, University of New South Wales, Sydney, NSW 2052, Australia; Laboratory of Immunopsychiatry, Neuroscience Research Australia, Sydney, NSW, Australia; Monash Institute of Pharmaceutical Science, Monash University, Parkville, Vic, Australia
| | - Paul Massa
- Department of Neurology, Upstate Medical University, Syracuse, NY 13210, USA; Department of Microbiology and Immunology, Upstate Medical University, Syracuse, NY 13210, USA
| | - Frank A Middleton
- Department of Neuroscience & Physiology, Upstate Medical University, Syracuse, NY 13210, USA
| | - Cynthia Shannon Weickert
- Department of Neuroscience & Physiology, Upstate Medical University, Syracuse, NY 13210, USA; School of Psychiatry, Faculty of Medicine, University of New South Wales, Sydney, NSW 2052, Australia; Schizophrenia Research Laboratory, Neuroscience Research Australia, Randwick, NSW 2031, Australia.
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Messina A, Cuccì G, Crescimanno C, Signorelli MS. Clinical anatomy of the precuneus and pathogenesis of the schizophrenia. Anat Sci Int 2023:10.1007/s12565-023-00730-w. [PMID: 37340095 DOI: 10.1007/s12565-023-00730-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Accepted: 05/12/2023] [Indexed: 06/22/2023]
Abstract
Recent evidence has shown that the precuneus plays a role in the pathogenesis of schizophrenia. The precuneus is a structure of the parietal lobe's medial and posterior cortex, representing a central hub involved in multimodal integration processes. Although neglected for several years, the precuneus is highly complex and crucial for multimodal integration. It has extensive connections with different cerebral areas and is an interface between external stimuli and internal representations. In human evolution, the precuneus has increased in size and complexity, allowing the development of higher cognitive functions, such as visual-spatial ability, mental imagery, episodic memory, and other tasks involved in emotional processing and mentalization. This paper reviews the functions of the precuneus and discusses them concerning the psychopathological aspects of schizophrenia. The different neuronal circuits, such as the default mode network (DMN), in which the precuneus is involved and its alterations in the structure (grey matter) and the disconnection of pathways (white matter) are described.
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Affiliation(s)
- Antonino Messina
- Department of Clinical and Experimental Medicine, Psychiatry Unit, University of Catania, Catania, Italy.
| | | | | | - Maria Salvina Signorelli
- Department of Clinical and Experimental Medicine, Psychiatry Unit, University of Catania, Catania, Italy
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Smigielski L, Stämpfli P, Wotruba D, Buechler R, Sommer S, Gerstenberg M, Theodoridou A, Walitza S, Rössler W, Heekeren K. White matter microstructure and the clinical risk for psychosis: A diffusion tensor imaging study of individuals with basic symptoms and at ultra-high risk. Neuroimage Clin 2022; 35:103067. [PMID: 35679786 PMCID: PMC9178487 DOI: 10.1016/j.nicl.2022.103067] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 05/19/2022] [Accepted: 05/28/2022] [Indexed: 12/29/2022]
Abstract
This DTI cross-sectional study compared UHR, basic symptom & control groups (n = 112). The splenium of UHR individuals exhibited differences in fractional anisotropy (FA). Basic symptoms alone were not associated with white matter microstructure changes. Large differences in FA & radial diffusivity were found in converters to psychosis. Regional FA was inversely correlated with the general psychopathology domain.
Background Widespread white matter abnormalities are a frequent finding in chronic schizophrenia patients. More inconsistent results have been provided by the sparser literature on at-risk states for psychosis, i.e., emerging subclinical symptoms. However, considering risk as a homogenous construct, an approach of earlier studies, may impede our understanding of neuro-progression into psychosis. Methods An analysis was conducted of 3-Tesla MRI diffusion and symptom data from 112 individuals (mean age, 21.97 ± 4.19) within two at-risk paradigm subtypes, only basic symptoms (n = 43) and ultra-high risk (n = 37), and controls (n = 32). Between-group comparisons (involving three study groups and further split based on the subsequent transition to schizophrenia) of four diffusion-tensor-imaging-derived scalars were performed using voxelwise tract-based spatial statistics, followed by correlational analyses with Structured Interview for Prodromal Syndromes responses. Results Relative to controls, fractional anisotropy was lower in the splenium of the corpus callosum of ultra-high-risk individuals, but only before stringent multiple-testing correction, and negatively correlated with General Symptom severity among at-risk individuals. At-risk participants who transitioned to schizophrenia within 3 years, compared to those that did not transition, had more severe WM differences in fractional anisotropy and radial diffusivity (particularly in the corpus callosum, anterior corona radiata, and motor/sensory tracts), which were even more extensive compared to healthy controls. Conclusions These findings align with the subclinical symptom presentation and more extensive disruptions in converters, suggestive of severity-related demyelination or axonal pathology. Fine-grained but detectable differences among ultra-high-risk subjects (i.e., with brief limited intermittent and/or attenuated psychotic symptoms) point to the splenium as a discrete site of emerging psychopathology, while basic symptoms alone were not associated with altered fractional anisotropy.
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Affiliation(s)
- Lukasz Smigielski
- The Zurich Program for Sustainable Development of Mental Health Services (ZInEP), Psychiatric University Hospital Zurich, University of Zurich, Zurich, Switzerland; Department of Child and Adolescent Psychiatry and Psychotherapy, Psychiatric University Hospital Zurich, University of Zurich, Zurich, Switzerland.
| | - Philipp Stämpfli
- Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric University Hospital Zurich, University of Zurich, Zurich, Switzerland; MR-Center of the Psychiatric Hospital and the Department of Child and Adolescent Psychiatry, University of Zurich, Zurich, Switzerland
| | - Diana Wotruba
- The Zurich Program for Sustainable Development of Mental Health Services (ZInEP), Psychiatric University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Roman Buechler
- The Zurich Program for Sustainable Development of Mental Health Services (ZInEP), Psychiatric University Hospital Zurich, University of Zurich, Zurich, Switzerland; Department of Neuroradiology, University Hospital of Zurich, Zurich, Switzerland
| | - Stefan Sommer
- Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric University Hospital Zurich, University of Zurich, Zurich, Switzerland; MR-Center of the Psychiatric Hospital and the Department of Child and Adolescent Psychiatry, University of Zurich, Zurich, Switzerland
| | - Miriam Gerstenberg
- Department of Child and Adolescent Psychiatry and Psychotherapy, Psychiatric University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Anastasia Theodoridou
- The Zurich Program for Sustainable Development of Mental Health Services (ZInEP), Psychiatric University Hospital Zurich, University of Zurich, Zurich, Switzerland; Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Susanne Walitza
- Department of Child and Adolescent Psychiatry and Psychotherapy, Psychiatric University Hospital Zurich, University of Zurich, Zurich, Switzerland; Neuroscience Center Zurich, University of Zurich and ETH Zurich, Zurich, Switzerland; Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
| | - Wulf Rössler
- The Zurich Program for Sustainable Development of Mental Health Services (ZInEP), Psychiatric University Hospital Zurich, University of Zurich, Zurich, Switzerland; Department of Psychiatry and Psychotherapy, Charité Universitätsmedizin, Campus Charité Mitte, Berlin, Germany; Laboratory of Neuroscience (LIM 27), Institute of Psychiatry, Universidade de São Paulo, São Paulo, Brazil
| | - Karsten Heekeren
- The Zurich Program for Sustainable Development of Mental Health Services (ZInEP), Psychiatric University Hospital Zurich, University of Zurich, Zurich, Switzerland; Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric University Hospital Zurich, University of Zurich, Zurich, Switzerland; Department of Psychiatry and Psychotherapy I, LVR-Hospital, Cologne, Germany
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Jiang Y, Schulze-Hentrich JM, Jakovcevski M. Editorial: Neuroepigenetics of Neuropsychiatric Disease—Hope, Success and Obstacles for Translational Findings and Applications. Front Neurosci 2022; 16:886695. [PMID: 35431770 PMCID: PMC9011190 DOI: 10.3389/fnins.2022.886695] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Accepted: 03/07/2022] [Indexed: 11/13/2022] Open
Affiliation(s)
- Yan Jiang
- Institute of Brain Science, Fudan University, Shanghai, China
| | - Julia M. Schulze-Hentrich
- Centre for Rare Diseases, Institute of Medical Genetics and Applied Genomics, University Hospital and Faculty of Medicine, University of Tübingen, Tübingen, Germany
| | - Mira Jakovcevski
- Institute of Biology II - Functional Epigenetics in the Animal Model, RWTH Aachen University, Aachen, Germany
- *Correspondence: Mira Jakovcevski
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6
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Chang S, Varadarajan D, Yang J, Chen IA, Kura S, Magnain C, Augustinack JC, Fischl B, Greve DN, Boas DA, Wang H. Scalable mapping of myelin and neuron density in the human brain with micrometer resolution. Sci Rep 2022; 12:363. [PMID: 35013441 PMCID: PMC8748995 DOI: 10.1038/s41598-021-04093-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Accepted: 12/03/2021] [Indexed: 12/23/2022] Open
Abstract
Optical coherence tomography (OCT) is an emerging 3D imaging technique that allows quantification of intrinsic optical properties such as scattering coefficient and back-scattering coefficient, and has proved useful in distinguishing delicate microstructures in the human brain. The origins of scattering in brain tissues are contributed by the myelin content, neuron size and density primarily; however, no quantitative relationships between them have been reported, which hampers the use of OCT in fundamental studies of architectonic areas in the human brain and the pathological evaluations of diseases. Here, we built a generalized linear model based on Mie scattering theory that quantitatively links tissue scattering to myelin content and neuron density in the human brain. We report a strong linear relationship between scattering coefficient and the myelin content that is retained across different regions of the brain. Neuronal cell body turns out to be a secondary contribution to the overall scattering. The optical property of OCT provides a label-free solution for quantifying volumetric myelin content and neuron cells in the human brain.
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Affiliation(s)
- Shuaibin Chang
- Department of Electrical and Computer Engineering, Boston University, 8 St Mary's St, Boston, 02215, USA
| | - Divya Varadarajan
- Department of Radiology, Massachusetts General Hospital, A.A. Martinos Center for Biomedical Imaging, 13th Street, Boston, 02129, USA
| | - Jiarui Yang
- Department of Biomedical Engineering, Boston University, 44 Cummington Mall, Boston, 02215, USA
| | - Ichun Anderson Chen
- Department of Biomedical Engineering, Boston University, 44 Cummington Mall, Boston, 02215, USA
| | - Sreekanth Kura
- Department of Biomedical Engineering, Boston University, 44 Cummington Mall, Boston, 02215, USA
| | - Caroline Magnain
- Department of Radiology, Massachusetts General Hospital, A.A. Martinos Center for Biomedical Imaging, 13th Street, Boston, 02129, USA
| | - Jean C Augustinack
- Department of Radiology, Massachusetts General Hospital, A.A. Martinos Center for Biomedical Imaging, 13th Street, Boston, 02129, USA
| | - Bruce Fischl
- Department of Radiology, Massachusetts General Hospital, A.A. Martinos Center for Biomedical Imaging, 13th Street, Boston, 02129, USA
| | - Douglas N Greve
- Department of Radiology, Massachusetts General Hospital, A.A. Martinos Center for Biomedical Imaging, 13th Street, Boston, 02129, USA
| | - David A Boas
- Department of Biomedical Engineering, Boston University, 44 Cummington Mall, Boston, 02215, USA
- Department of Electrical and Computer Engineering, Boston University, 8 St Mary's St, Boston, 02215, USA
| | - Hui Wang
- Department of Radiology, Massachusetts General Hospital, A.A. Martinos Center for Biomedical Imaging, 13th Street, Boston, 02129, USA.
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Sustained ErbB Activation Causes Demyelination and Hypomyelination by Driving Necroptosis of Mature Oligodendrocytes and Apoptosis of Oligodendrocyte Precursor Cells. J Neurosci 2021; 41:9872-9890. [PMID: 34725188 PMCID: PMC8638686 DOI: 10.1523/jneurosci.2922-20.2021] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Revised: 09/27/2021] [Accepted: 10/24/2021] [Indexed: 11/26/2022] Open
Abstract
Oligodendrocytes are vulnerable to genetic and environmental insults and its injury leads to demyelinating diseases. The roles of ErbB receptors in maintaining the CNS myelin integrity are largely unknown. Here, we overactivate ErbB receptors that mediate signaling of either neuregulin (NRG) or epidermal growth factor (EGF) family growth factors and found their synergistic activation caused deleterious outcomes in white matter. Sustained ErbB activation induced by the tetracycline-dependent mouse tool Plp-tTA resulted in demyelination, axonal degeneration, oligodendrocyte precursor cell (OPC) proliferation, astrogliosis, and microgliosis in white matter. Moreover, there was hypermyelination before these inflammatory pathologic events. In contrast, sustained ErbB activation induced by another tetracycline-dependent mouse tool Sox10+/rtTA caused hypomyelination in the corpus callosum and optic nerve, which appeared to be a developmental deficit and did not associate with OPC regeneration, astrogliosis, or microgliosis. By tracing the differentiation states of cells expressing tetracycline-controlled transcriptional activator (tTA)/reverse tTA (rtTA)-dependent transgene or pulse-labeled reporter proteins in vitro and in vivo, we found that Plp-tTA targeted mainly mature oligodendrocytes (MOs), whereas Sox10+/rtTA targeted OPCs and newly-formed oligodendrocytes (NFOs). The distinct phenotypes of mice with ErbB overactivation induced by Plp-tTA and Sox10+/rtTA consolidated their nonoverlapping targeting preferences in the oligodendrocyte lineage, and enabled us to demonstrate that ErbB overactivation in MOs induced necroptosis that caused inflammatory demyelination, whereas in OPCs induced apoptosis that caused noninflammatory hypomyelination. Early interference with aberrant ErbB activation ceased oligodendrocyte deaths and restored myelin development in both mice. This study suggests that aberrant ErbB activation is an upstream pathogenetic mechanism of demyelinating diseases, providing a potential therapeutic target. SIGNIFICANCE STATEMENT Primary oligodendropathy is one of the etiologic mechanisms for multiple sclerosis, and oligodendrocyte necroptosis is a pathologic hallmark in the disease. Moreover, the demyelinating disease is now a broad concept that embraces schizophrenia, in which white matter lesions are an emerging feature. ErbB overactivation has been implicated in schizophrenia by genetic analysis and postmortem studies. This study suggests the etiologic implications of ErbB overactivation in myelin pathogenesis and elucidates the pathogenetic mechanisms.
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Schoonover KE, Roberts RC. Markers of copper transport in the cingulum bundle in schizophrenia. Schizophr Res 2021; 228:124-133. [PMID: 33434726 PMCID: PMC7988290 DOI: 10.1016/j.schres.2020.11.053] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 11/16/2020] [Accepted: 11/30/2020] [Indexed: 11/26/2022]
Abstract
Imaging and postmortem studies indicate that schizophrenia subjects exhibit abnormal connectivity in several white matter tracts, including the cingulum bundle. Copper chelators given to experimental animals damage myelin and myelin-producing oligodendrocytes, and the substantia nigra of schizophrenia subjects shows lower levels of copper, copper transporters, and copper-utilizing enzymes. This study aimed to elucidate the potential role of copper homeostasis in white matter pathology in schizophrenia. Protein levels of the copper transporters ATP7A and CTR1, and dysbindin-1, an upstream modulator of copper metabolism and schizophrenia susceptibility factor, were measured using Western blot analyses of the postmortem cingulum bundle of schizophrenia subjects (n=16) and matched controls (n=13). Additionally, the patient group was subdivided by treatment status: off- (n=8) or on-medication (n=8). Relationships between proteins from the current study were correlated among themselves and markers of axonal integrity previously measured in the same cohort. Schizophrenia subjects exhibited similar protein levels to controls, with no effect of antipsychotic treatment. The dysbindin-1A/1BC relationship was positive in controls and schizophrenia subjects; however, antipsychotic treatment appeared to reverse this relationship in a statistically different manner from that of controls and unmedicated subjects. The relationships between dysbindin-1A/neurofilament heavy and ATP7A/α-tubulin were positively correlated in the schizophrenia group that was significantly different from the lack of correlation in controls. Copper transporters and dysbindin-1 appear to be more significantly affected in the grey matter of schizophrenia subjects. However, the relationships among proteins in white matter may be more substantial and dependent on treatment status.
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Affiliation(s)
- Kirsten E Schoonover
- Department of Psychology and Behavioral Neuroscience, University of Alabama at Birmingham, Birmingham, AL 35294, United States of America.
| | - Rosalinda C Roberts
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham, Birmingham, AL 35294, United States of America.
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9
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Uranova NA, Vikhreva OV, Rakhmanova VI, Orlovskaya DD. Dystrophy of Oligodendrocytes and Adjacent Microglia in Prefrontal Gray Matter in Schizophrenia. Front Psychiatry 2020; 11:204. [PMID: 32292358 PMCID: PMC7135882 DOI: 10.3389/fpsyt.2020.00204] [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] [Received: 12/10/2019] [Accepted: 03/02/2020] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Some evidence support the notion that microglia activation in acute state of schizophrenia might contribute to damage of oligodendrocytes and myelinated fibers. Previously we found dystrophic changes of oligodendrocytes in prefrontal white matter in schizophrenia subjects displaying predominantly positive symptoms as compared to controls. The aim of the study was to verify whether microglial activation might contribute to dystrophic changes of oligodendrocytes in prefrontal gray matter in this clinical subgroup. METHODS Transmission electron microscopy and morphometry of microglia and adjacent oligodendrocytes were performed in layer 5 of the prefrontal cortex (BA10) in the schizophrenia subjects displaying predominantly positive symptoms (SPPS, n = 12), predominantly negative symptoms (SPNS, n = 9) and healthy controls (n = 20). RESULTS Qualitative study showed microglial activation and dystrophic alterations of microglia and oligodendrocytes adjacent to each other in both subgroups as compared to controls. A significant reduction in volume density (Vv) and the number (N) of mitochondria and an increase in N of lipofuscin granules were found in oligodendrocytes and adjacent microglia in both subgroups. Vv of lipofuscin granules, Vv and N of vacuoles of endoplasmic reticulum in microglia were increased significantly in the SPPS subgroup as compared to controls. In the SPPS subgroup Vv and N of mitochondria in microglia were correlated with N of vacuoles in microglia (r = -0.61, p < 0.05) and with Vv (r = 0.79, p < 0.01) and N (r = 0.59, p < 0.05) of mitochondria in oligodendrocytes. Vv of mitochondria in microglia was also correlated with Vv and N of vacuoles in oligodendrocytes in the SPPS subgroup (r = 0.76, p < 0.01). Area of nucleus of microglial cells was correlated negatively with age (r = -0.76, p < 0.01) and age at illness onset (r = -0.65, p < 0.05) in the SPPS subgroup. In the SPNS subgroup N of mitochondria in microglia was correlated with Vv of lipofuscin granules in oligodendrocytes (r = -0.9, p < 0.01). There were no significant correlations between these parameters in the control group. DISCUSSION Microglial dystrophy might contribute to oligodendrocyte dystrophy in the schizophrenia subjects with predominantly positive symptoms during relapse. Mitochondria in microglia and oligodendrocytes may be a target for treatment strategy of schizophrenia.
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Affiliation(s)
- Natalya A Uranova
- Laboratory of Clinical Neuropathology, Mental Health Research Center, Moscow, Russia
| | - Olga V Vikhreva
- Laboratory of Clinical Neuropathology, Mental Health Research Center, Moscow, Russia
| | | | - Diana D Orlovskaya
- Laboratory of Clinical Neuropathology, Mental Health Research Center, Moscow, Russia
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Raabe FJ, Slapakova L, Rossner MJ, Cantuti-Castelvetri L, Simons M, Falkai PG, Schmitt A. Oligodendrocytes as A New Therapeutic Target in Schizophrenia: From Histopathological Findings to Neuron-Oligodendrocyte Interaction. Cells 2019; 8:cells8121496. [PMID: 31771166 PMCID: PMC6952785 DOI: 10.3390/cells8121496] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Revised: 11/20/2019] [Accepted: 11/21/2019] [Indexed: 12/11/2022] Open
Abstract
Imaging and postmortem studies have revealed disturbed oligodendroglia-related processes in patients with schizophrenia and provided much evidence for disturbed myelination, irregular gene expression, and altered numbers of oligodendrocytes in the brains of schizophrenia patients. Oligodendrocyte deficits in schizophrenia might be a result of failed maturation and disturbed regeneration and may underlie the cognitive deficits of the disease, which are strongly associated with impaired long-term outcome. Cognition depends on the coordinated activity of neurons and interneurons and intact connectivity. Oligodendrocyte precursors form a synaptic network with parvalbuminergic interneurons, and disturbed crosstalk between these cells may be a cellular basis of pathology in schizophrenia. However, very little is known about the exact axon-glial cellular and molecular processes that may be disturbed in schizophrenia. Until now, investigations were restricted to peripheral tissues, such as blood, correlative imaging studies, genetics, and molecular and histological analyses of postmortem brain samples. The advent of human-induced pluripotent stem cells (hiPSCs) will enable functional analysis in patient-derived living cells and holds great potential for understanding the molecular mechanisms of disturbed oligodendroglial function in schizophrenia. Targeting such mechanisms may contribute to new treatment strategies for previously treatment-resistant cognitive symptoms.
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Affiliation(s)
- Florian J. Raabe
- Department of Psychiatry and Psychotherapy, University Hospital, LMU Munich, Nussbaumstrasse 7, 80336 Munich, Germany; (F.J.R.); (L.S.); (P.G.F.)
- International Max Planck Research School for Translational Psychiatry (IMPRS-TP), Kraepelinstr, 2-10, 80804 Munich, Germany
- Molecular and Behavioural Neurobiology, Department of Psychiatry and Psychotherapy, University Hospital, LMU Munich, 80336 Munich, Germany;
| | - Lenka Slapakova
- Department of Psychiatry and Psychotherapy, University Hospital, LMU Munich, Nussbaumstrasse 7, 80336 Munich, Germany; (F.J.R.); (L.S.); (P.G.F.)
- International Max Planck Research School for Translational Psychiatry (IMPRS-TP), Kraepelinstr, 2-10, 80804 Munich, Germany
| | - Moritz J. Rossner
- Molecular and Behavioural Neurobiology, Department of Psychiatry and Psychotherapy, University Hospital, LMU Munich, 80336 Munich, Germany;
| | - Ludovico Cantuti-Castelvetri
- German Center for Neurodegenerative Diseases (DZNE), Feodor-Lynen Str. 17, 81377 Munich, Germany; (L.C.-C.); (M.S.)
| | - Mikael Simons
- German Center for Neurodegenerative Diseases (DZNE), Feodor-Lynen Str. 17, 81377 Munich, Germany; (L.C.-C.); (M.S.)
- Munich Cluster for Systems Neurology (SyNergy), 81377 Munich, Germany
- Institute of Neuronal Cell Biology, Technical University Munich, 80805 Munich, Germany
| | - Peter G. Falkai
- Department of Psychiatry and Psychotherapy, University Hospital, LMU Munich, Nussbaumstrasse 7, 80336 Munich, Germany; (F.J.R.); (L.S.); (P.G.F.)
| | - Andrea Schmitt
- Department of Psychiatry and Psychotherapy, University Hospital, LMU Munich, Nussbaumstrasse 7, 80336 Munich, Germany; (F.J.R.); (L.S.); (P.G.F.)
- Molecular and Behavioural Neurobiology, Department of Psychiatry and Psychotherapy, University Hospital, LMU Munich, 80336 Munich, Germany;
- Laboratory of Neuroscience (LIM27), Institute of Psychiatry, University of Sao Paulo, 05453-010 São Paulo, Brazil
- Correspondence: ; Tel.: +49-(0)89-4400-52761; Fax: +49-(0)89-4400-55530
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11
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Lee FHF, Lai TKY, Su P, Liu F. Altered cortical Cytoarchitecture in the Fmr1 knockout mouse. Mol Brain 2019; 12:56. [PMID: 31200759 PMCID: PMC6570929 DOI: 10.1186/s13041-019-0478-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Accepted: 06/03/2019] [Indexed: 12/15/2022] Open
Abstract
Fragile X syndrome (FXS) is a neurodevelopmental disorder caused by silencing of the FMR1 gene and subsequent loss of its protein product, fragile X retardation protein (FMRP). One of the most robust neuropathological findings in post-mortem human FXS and Fmr1 KO mice is the abnormal increase in dendritic spine densities, with the majority of spines showing an elongated immature morphology. However, the exact mechanisms of how FMRP can regulate dendritic spine development are still unclear. Abnormal dendritic spines can result from disturbances of multiple factors during neurodevelopment, such as alterations in neuron numbers, position and glial cells. In this study, we undertook a comprehensive histological analysis of the cerebral cortex in Fmr1 KO mice. They displayed significantly fewer neuron and PV-interneuron numbers, along with altered cortical lamination patterns. In terms of glial cells, Fmr1 KO mice exhibited an increase in Olig2-oligodendrocytes, which corresponded to the abnormally higher myelin expression in the corpus callosum. Iba1-microglia were significantly reduced but GFAP-astrocyte numbers and intensity were elevated. Using primary astrocytes derived from KO mice, we further demonstrated the presence of astrogliosis characterized by an increase in GFAP expression and astrocyte hypertrophy. Our findings provide important information on the cortical architecture of Fmr1 KO mice, and insights towards possible mechanisms associated with FXS.
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Affiliation(s)
- Frankie H F Lee
- Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Ontario, M5T 1R8, Canada
| | - Terence K Y Lai
- Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Ontario, M5T 1R8, Canada.,Department of Physiology, University of Toronto, Toronto, Ontario, M5T 1R8, Canada
| | - Ping Su
- Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Ontario, M5T 1R8, Canada
| | - Fang Liu
- Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Ontario, M5T 1R8, Canada. .,Department of Physiology, University of Toronto, Toronto, Ontario, M5T 1R8, Canada. .,Department of Psychiatry, University of Toronto, Toronto, Ontario, M5T 1R8, Canada.
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12
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Discoidin domain receptor 1 gene variants are associated with decreased white matter fractional anisotropy and decreased processing speed in schizophrenia. J Psychiatr Res 2019; 110:74-82. [PMID: 30597424 DOI: 10.1016/j.jpsychires.2018.12.021] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Revised: 12/04/2018] [Accepted: 12/21/2018] [Indexed: 12/20/2022]
Abstract
DDR1 has been linked to schizophrenia (SZ) and myelination. Here, we tested whether DDR1 variants in people at risk for SZ influence white matter (WM) structural variations and cognitive processing speed (PS). First, following a case-control design (Study 1), SZ patients (N = 1193) and controls (N = 1839) were genotyped for rs1264323 and rs2267641 at DDR1, and the frequencies were compared. We replicated the association between DDR1 and SZ (rs1264323, adjusted P = 0.015). Carriers of the rs1264323AA combined with the rs2267641AC or CC genotype are at risk to develop SZ compared to the other genotype combinations. Second, SZ patients (Study 2, N = 194) underwent an evaluation of PS using the Trail Making Test (TMT) and DDR1 genotyping. To compare PS between DDR1 genotype groups, we conducted an analysis of covariance (including rs1264323 as a covariate) and found that SZ patients with the rs2267641CC genotype had decreased PS compared to patients with the AA and AC genotypes. Third, 54 patients (Study 3) from Study 2 were selected based on rs1264323 genotype to undergo reevaluation, including a DTI-MRI brain scan. To test for associations between PS, WM microstructure and DDR1 genotype, we first localized those WM regions where fractional anisotropy (FA) was correlated with PS and tested whether FA showed differences between the rs1264323 genotypes. SZ patients with the rs1264323AA genotype showed decreased FA in WM regions associated with decreased PS. We conclude that DDR1 variants may confer a risk of SZ through WM microstructural alterations leading to cognitive dysfunction.
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13
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Studying and modulating schizophrenia-associated dysfunctions of oligodendrocytes with patient-specific cell systems. NPJ SCHIZOPHRENIA 2018; 4:23. [PMID: 30451850 PMCID: PMC6242875 DOI: 10.1038/s41537-018-0066-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Accepted: 10/30/2018] [Indexed: 02/07/2023]
Abstract
Postmortem studies in patients with schizophrenia (SCZ) have revealed deficits in myelination, abnormalities in myelin gene expression and altered numbers of oligodendrocytes in the brain. However, gaining mechanistic insight into oligodendrocyte (OL) dysfunction and its contribution to SCZ has been challenging because of technical hurdles. The advent of individual patient-derived human-induced pluripotent stem cells (hiPSCs), combined with the generation of in principle any neuronal and glial cell type, including OLs and oligodendrocyte precursor cells (OPCs), holds great potential for understanding the molecular basis of the aetiopathogenesis of genetically complex psychiatric diseases such as SCZ and could pave the way towards personalized medicine. The development of neuronal and glial co-culture systems now appears to enable the in vitro study of SCZ-relevant neurobiological endophenotypes, including OL dysfunction and myelination, with unprecedented construct validity. Nonetheless, the meaningful stratification of patients before the subsequent functional analyses of patient-derived cell systems still represents an important bottleneck. Here, to improve the predictive power of ex vivo disease modelling we propose using hiPSC technology to focus on representatives of patient subgroups stratified for genomic and/or phenomic features and neurobiological cell systems. Therefore, this review will outline the evidence for the involvement of OPCs/OLs in SCZ in the context of their proposed functions, including myelination and axon support, the implications for hiPSC-based cellular disease modelling and potential strategies for patient selection.
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14
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Increased gyrification in schizophrenia and non affective first episode of psychosis. Schizophr Res 2018; 193:269-275. [PMID: 28729037 DOI: 10.1016/j.schres.2017.06.060] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Revised: 06/28/2017] [Accepted: 06/29/2017] [Indexed: 11/23/2022]
Abstract
BACKGROUND Prefrontal cortex gyrification has been suggested to be altered in patients with schizophrenia and first episode psychosis. Therefore, it may represent a possible trait marker for these illnesses and an indirect evidence of a disrupted underlying connectivity. The aim of this study was to add further evidence to the existing literature on the role of prefrontal gyrification in psychosis by carrying out a study on a sizeable sample of chronic patients with schizophrenia and non-affective first-episode psychosis (FEP-NA) patients. METHODS Seventy-two patients with schizophrenia, 51 FEP-NA patients (12 who later develop schizophrenia) and 95 healthy controls (HC) underwent magnetic resonance imaging (MRI). Cortical folding was quantified using the automated gyrification index (GI). GI values were compared among groups and related to clinical variables. RESULTS Both FEP-NA and patients with schizophrenia showed a higher mean prefrontal GI compared to HC (all p<0.05). Interestingly, no differences have been observed between the two patients groups as well as between FEP-NA patients who did and did not develop schizophrenia. CONCLUSIONS Our results suggest the presence of a shared aberrant prefrontal GI in subjects with both schizophrenia and first-episode psychosis. These findings support the hypothesis that altered GI represents a neurodevelopmental trait marker for psychosis, which may be involved in the associated neurocognitive deficits.
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15
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Ramanathan M, Majzoub K, Rao DS, Neela PH, Zarnegar BJ, Mondal S, Roth JG, Gai H, Kovalski JR, Siprashvili Z, Palmer TD, Carette JE, Khavari PA. RNA-protein interaction detection in living cells. Nat Methods 2018; 15:207-212. [PMID: 29400715 DOI: 10.1038/nmeth.4601] [Citation(s) in RCA: 206] [Impact Index Per Article: 34.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Accepted: 12/19/2017] [Indexed: 12/30/2022]
Abstract
RNA-protein interactions play numerous roles in cellular function and disease. Here we describe RNA-protein interaction detection (RaPID), which uses proximity-dependent protein labeling, based on the BirA* biotin ligase, to rapidly identify the proteins that bind RNA sequences of interest in living cells. RaPID displays utility in multiple applications, including in evaluating protein binding to mutant RNA motifs in human genetic disorders, in uncovering potential post-transcriptional networks in breast cancer, and in discovering essential host proteins that interact with Zika virus RNA. To improve the BirA*-labeling component of RaPID, moreover, a new mutant BirA* was engineered from Bacillus subtilis, termed BASU, that enables >1,000-fold faster kinetics and >30-fold increased signal-to-noise ratio over the prior standard Escherichia coli BirA*, thereby enabling direct study of RNA-protein interactions in living cells on a timescale as short as 1 min.
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Affiliation(s)
- Muthukumar Ramanathan
- Program in Epithelial Biology, Stanford University School of Medicine, Stanford, California, USA
| | - Karim Majzoub
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, California, USA
| | - Deepti S Rao
- Program in Epithelial Biology, Stanford University School of Medicine, Stanford, California, USA
| | - Poornima H Neela
- Program in Epithelial Biology, Stanford University School of Medicine, Stanford, California, USA
| | - Brian J Zarnegar
- Program in Epithelial Biology, Stanford University School of Medicine, Stanford, California, USA
| | - Smarajit Mondal
- Program in Epithelial Biology, Stanford University School of Medicine, Stanford, California, USA
| | - Julien G Roth
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, California, USA
| | - Hui Gai
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, California, USA
| | - Joanna R Kovalski
- Program in Epithelial Biology, Stanford University School of Medicine, Stanford, California, USA
| | - Zurab Siprashvili
- Program in Epithelial Biology, Stanford University School of Medicine, Stanford, California, USA
| | - Theo D Palmer
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, California, USA
| | - Jan E Carette
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, California, USA
| | - Paul A Khavari
- Program in Epithelial Biology, Stanford University School of Medicine, Stanford, California, USA.,Veterans Affairs Palo Alto Healthcare System, Palo Alto, California, USA
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16
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Fontana BD, Mezzomo NJ, Kalueff AV, Rosemberg DB. The developing utility of zebrafish models of neurological and neuropsychiatric disorders: A critical review. Exp Neurol 2018; 299:157-171. [DOI: 10.1016/j.expneurol.2017.10.004] [Citation(s) in RCA: 130] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Revised: 09/15/2017] [Accepted: 10/04/2017] [Indexed: 12/30/2022]
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17
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Genetic variation is associated with RTN4R expression and working memory processing in healthy humans. Brain Res Bull 2017; 134:162-167. [PMID: 28755979 DOI: 10.1016/j.brainresbull.2017.07.015] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Revised: 07/19/2017] [Accepted: 07/23/2017] [Indexed: 02/01/2023]
Abstract
The Nogo receptor (NgR) is implicated in neurodevelopmental processes and it participates in inhibiting axonal growth. Consistent with its high levels of expression in the prefrontal cortex, animal studies indicate that NgR is relevant for prefrontal-related cognitive processing. Given that genetic variation may alter mechanisms of gene expression impacting molecular and systems-level phenotypes, we investigated the association of genetic variation with the expression of the NgR coding gene (RTN4R), as well as with prefrontal correlates at progressively greater biological distance from gene effects. First, we studied the association of single nucleotide polymorphisms (SNPs) with RTN4R mRNA expression in postmortem prefrontal cortex of humans without psychiatric illnesses. Then, we probed in peripheral blood mononuclear cells (PBMCs) the association that we found in prefrontal tissue. Thus, we investigated whether functional genetic variation affecting RTN4R expression is also associated with prefrontal activity during working memory. We found that rs696884 (A/G) predicted these phenotypes. Specifically, the AA genotype was associated with lower RTN4R mRNA expression levels in the prefrontal cortex and PBMCs and inefficient prefrontal activity during working memory compared to the GG genotype. These results suggest that genetic variation associated with RTN4R mRNA expression influences prefrontal physiology in healthy individuals. Furthermore, they highlight the need for further investigations of the role of NgR in the pathophysiology of brain disorders associated with prefrontal dysfunction.
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18
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Weickenmeier J, de Rooij R, Budday S, Steinmann P, Ovaert T, Kuhl E. Brain stiffness increases with myelin content. Acta Biomater 2016; 42:265-272. [PMID: 27475531 DOI: 10.1016/j.actbio.2016.07.040] [Citation(s) in RCA: 172] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Revised: 05/31/2016] [Accepted: 07/22/2016] [Indexed: 10/21/2022]
Abstract
UNLABELLED Brain stiffness plays an important role in neuronal development and disease, but reported stiffness values vary significantly for different species, for different brains, and even for different regions within the same brain. Despite extensive research throughout the past decade, the mechanistic origin of these stiffness variations remains elusive. Here we show that brain tissue stiffness is correlated to the underlying tissue microstructure and directly proportional to the local myelin content. In 116 indentation tests of six freshly harvested bovine brains, we found that the cerebral stiffnesses of 1.33±0.63kPa in white matter and 0.68±0.20kPa in gray matter were significantly different (p<0.01). Strikingly, while the inter-specimen variation was rather moderate, the minimum and maximum cerebral white matter stiffnesses of 0.59±0.19 kPa and 2.36±0.64kPa in each brain varied by a factor of four on average. To provide a mechanistic interpretation for this variation, we performed a histological characterization of the tested brain regions. We stained the samples with hematoxylin and eosin and luxol fast blue and quantified the local myelin content using image analysis. Interestingly, we found that the cerebral white matter stiffness increased with increasing myelin content, from 0.72kPa at a myelin content of 64-2.45kPa at a myelin content of 89%, with a Pearson correlation coefficient of ρ=0.91 (p<0.01). This direct correlation could have significant neurological implications. During development, our results could help explain why immature, incompletely myelinated brains are softer than mature, myelinated brains and more vulnerable to mechanical insult as evident, for example, in shaken baby syndrome. During demyelinating disease, our findings suggest to use stiffness alterations as clinical markers for demyelination to quantify the onset of disease progression, for example, in multiple sclerosis. Taken together, our study indicates that myelin might play a more important function than previously thought: It not only insulates signal propagation and improves electrical function of single axons, it also provides structural support and mechanical stiffness to the brain as a whole. STATEMENT OF SIGNIFICANCE Increasing evidence suggests that the mechanical environment of the brain plays an important role in neuronal development and disease. Reported stiffness values vary significantly, but the origin of these variations remains unknown. Here we show that stiffness of our brain is correlated to the underlying tissue microstructure and directly proportional to the local myelin content. Myelin has been discovered in 1854 as an insulating layer around nerve cells to improve electric signal propagation. Our study now shows that it also plays an important mechanical role: Using a combined mechanical characterization and histological characterization, we found that the white matter stiffness increases linearly with increasing myelin content, from 0.5kPa at a myelin content of 63-2.5kPa at 92%.
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Increased density of DISC1-immunoreactive oligodendroglial cells in fronto-parietal white matter of patients with paranoid schizophrenia. Eur Arch Psychiatry Clin Neurosci 2016; 266:495-504. [PMID: 26315603 DOI: 10.1007/s00406-015-0640-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Accepted: 08/20/2015] [Indexed: 12/11/2022]
Abstract
Profound white matter abnormalities have repeatedly been described in schizophrenia, which involve the altered expression of numerous oligodendrocyte-associated genes. Transcripts of the disrupted-in-schizophrenia 1 (DISC1) gene, a key susceptibility factor in schizophrenia, have recently been shown to be expressed by oligodendroglial cells and to negatively regulate oligodendrocyte differentiation and maturation. To learn more about the putative role(s) of oligodendroglia-associated DISC1 in schizophrenia, we analyzed the density of DISC1-immunoreactive oligodendrocytes in the fronto-parietal white matter in postmortem brains of patients with schizophrenia. Compared with controls (N = 12) and cases with undifferentiated/residual schizophrenia (N = 6), there was a significantly increased density of DISC1-expressing glial cells in paranoid schizophrenia (N = 12), which unlikely resulted from neuroleptic treatment. Pathophysiologically, over-expression of DISC1 protein(s) in white matter oligodendrocytes might add to the reduced levels of two myelin markers, 2',3'-cyclic-nucleotide 3'-phosphodiesterase and myelin basic protein in schizophrenia. Moreover, it might significantly contribute to cell cycle abnormalities as well as to deficits in oligodendroglial cell differentiation and maturation found in schizophrenia.
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20
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Halene TB, Kozlenkov A, Jiang Y, Mitchell A, Javidfar B, Dincer A, Park R, Wiseman J, Croxson P, Giannaris EL, Hof PR, Roussos P, Dracheva S, Hemby SE, Akbarian S. NeuN+ neuronal nuclei in non-human primate prefrontal cortex and subcortical white matter after clozapine exposure. Schizophr Res 2016; 170:235-44. [PMID: 26776227 PMCID: PMC4740223 DOI: 10.1016/j.schres.2015.12.016] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2015] [Revised: 12/24/2015] [Accepted: 12/28/2015] [Indexed: 12/01/2022]
Abstract
Increased neuronal densities in subcortical white matter have been reported for some cases with schizophrenia. The underlying cellular and molecular mechanisms remain unresolved. We exposed 26 young adult macaque monkeys for 6 months to either clozapine, haloperidol or placebo and measured by structural MRI frontal gray and white matter volumes before and after treatment, followed by observer-independent, flow-cytometry-based quantification of neuronal and non-neuronal nuclei and molecular fingerprinting of cell-type specific transcripts. After clozapine exposure, the proportion of nuclei expressing the neuronal marker NeuN increased by approximately 50% in subcortical white matter, in conjunction with a more subtle and non-significant increase in overlying gray matter. Numbers and proportions of nuclei expressing the oligodendrocyte lineage marker, OLIG2, and cell-type specific RNA expression patterns, were maintained after antipsychotic drug exposure. Frontal lobe gray and white matter volumes remained indistinguishable between antipsychotic-drug-exposed and control groups. Chronic clozapine exposure increases the proportion of NeuN+ nuclei in frontal subcortical white matter, without alterations in frontal lobe volumes or cell type-specific gene expression. Further exploration of neurochemical plasticity in non-human primate brain exposed to antipsychotic drugs is warranted.
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Affiliation(s)
- Tobias B. Halene
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, USA,Corresponding author: Tobias B. Halene, MD PhD, Icahn School of Medicine at Mount Sinai, Department of Psychiatry, 1470 Madison Ave, Hess 9-105, New York, NY 10029, Tel: 646 627 5529, Fax: 646-537-9583,
| | - Alexey Kozlenkov
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Yan Jiang
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Amanda Mitchell
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Behnam Javidfar
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Aslihan Dincer
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Royce Park
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Jennifer Wiseman
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Paula Croxson
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Eustathia Lela Giannaris
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, Worcester, MA, USA
| | - Patrick R. Hof
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Panos Roussos
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, USA,Department of Genetics and Genomic Science and Institute for Multiscale Biology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Stella Dracheva
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Scott E. Hemby
- Department of Physiology and Pharmacology, Wake Forest University, Winston-Salem, NC, USA
| | - Schahram Akbarian
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, USA
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21
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Monin A, Fournier M, Baumann PS, Cuénod M, Do KQ. Role of Redox Dysregulation in White Matter Anomalies Associated with Schizophrenia. HANDBOOK OF BEHAVIORAL NEUROSCIENCE 2016. [DOI: 10.1016/b978-0-12-800981-9.00028-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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Converging models of schizophrenia--Network alterations of prefrontal cortex underlying cognitive impairments. Prog Neurobiol 2015; 134:178-201. [PMID: 26408506 DOI: 10.1016/j.pneurobio.2015.09.010] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2015] [Revised: 09/10/2015] [Accepted: 09/17/2015] [Indexed: 02/08/2023]
Abstract
The prefrontal cortex (PFC) and its connections with other brain areas are crucial for cognitive function. Cognitive impairments are one of the core symptoms associated with schizophrenia, and manifest even before the onset of the disorder. Altered neural networks involving PFC contribute to cognitive impairments in schizophrenia. Both genetic and environmental risk factors affect the development of the local circuitry within PFC as well as development of broader brain networks, and make the system vulnerable to further insults during adolescence, leading to the onset of the disorder in young adulthood. Since spared cognitive functions correlate with functional outcome and prognosis, a better understanding of the mechanisms underlying cognitive impairments will have important implications for novel therapeutics for schizophrenia focusing on cognitive functions. Multidisciplinary approaches, from basic neuroscience to clinical studies, are required to link molecules, circuitry, networks, and behavioral phenotypes. Close interactions among such fields by sharing a common language on connectomes, behavioral readouts, and other concepts are crucial for this goal.
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23
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Cassoli JS, Guest PC, Malchow B, Schmitt A, Falkai P, Martins-de-Souza D. Disturbed macro-connectivity in schizophrenia linked to oligodendrocyte dysfunction: from structural findings to molecules. NPJ SCHIZOPHRENIA 2015; 1:15034. [PMID: 27336040 PMCID: PMC4849457 DOI: 10.1038/npjschz.2015.34] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Revised: 08/10/2015] [Accepted: 08/19/2015] [Indexed: 01/20/2023]
Abstract
Schizophrenia is a severe psychiatric disorder with multi-factorial characteristics. A number of findings have shown disrupted synaptic connectivity in schizophrenia patients and emerging evidence suggests that this results from dysfunctional oligodendrocytes, the cells responsible for myelinating axons in white matter to promote neuronal conduction. The exact cause of this is not known, although recent imaging and molecular profiling studies of schizophrenia patients have identified changes in white matter tracts connecting multiple brain regions with effects on protein signaling networks involved in the myelination process. Further understanding of oligodendrocyte dysfunction in schizophrenia could lead to identification of novel drug targets for this devastating disease.
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Affiliation(s)
- Juliana Silva Cassoli
- Laboratory of Neuroproteomics, Department of Biochemistry and Tissue Biology, Institute of Biology, University of Campinas (UNICAMP) , Campinas, Brazil
| | - Paul C Guest
- Laboratory of Neuroproteomics, Department of Biochemistry and Tissue Biology, Institute of Biology, University of Campinas (UNICAMP) , Campinas, Brazil
| | - Berend Malchow
- Department of Psychiatry and Psychotherapy, Ludwig-Maximilians-University (LMU) , Munich, Germany
| | - Andrea Schmitt
- Department of Psychiatry and Psychotherapy, Ludwig-Maximilians-University (LMU), Munich, Germany; Laboratory of Neurosciences (LIM-27), Institute of Psychiatry, University of São Paulo (USP), São Paulo, Brazil
| | - Peter Falkai
- Department of Psychiatry and Psychotherapy, Ludwig-Maximilians-University (LMU) , Munich, Germany
| | - Daniel Martins-de-Souza
- Laboratory of Neuroproteomics, Department of Biochemistry and Tissue Biology, Institute of Biology, University of Campinas (UNICAMP), Campinas, Brazil; Laboratory of Neurosciences (LIM-27), Institute of Psychiatry, University of São Paulo (USP), São Paulo, Brazil; UNICAMP's Neurobiology Center, Campinas, Brazil
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The Paradoxical Relationship between White Matter, Psychopathology and Cognition in Schizophrenia: A Diffusion Tensor and Proton Spectroscopic Imaging Study. Neuropsychopharmacology 2015; 40:2248-57. [PMID: 25786581 PMCID: PMC4613618 DOI: 10.1038/npp.2015.72] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/03/2014] [Revised: 02/23/2015] [Accepted: 02/24/2015] [Indexed: 12/19/2022]
Abstract
White matter disruption has been repeatedly documented in schizophrenia consistent with microstructural disorganization (reduced fractional anisotropy (FA)) and axonal dysfunction (reduced N-acetylaspartate NAAc). However, the clinical significance of these abnormalities is poorly understood. Diffusion tensor and proton spectroscopic imaging where used to assess FA, axial diffusivity and radial diffusivity (RD), and supra-ventricular white matter NAAc, respectively, in 64 schizophrenia and 64 healthy subjects. Schizophrenia patients had reduced FA across several regions, with additional regions where FA correlated positively with positive symptoms severity. These regions included genu, body and splenium of corpus callosum, anterior and superior corona radiata, superior longitudinal and inferior fronto-occipital fasciculi, and internal capsule. The FA/symptoms relationships corresponded with opposite correlations between RD and positive symptoms. The schizophrenia group (SP group) had progressively reduced NAAc with age, and NAAc correlated negatively with positive symptoms. Cognition correlated positively with both FA and NAAc in controls, whereas in the SP group it had a negative correlation with NAAc and no significant relationship with FA. Antipsychotic dose did not account for the results. Correlates of psychosis, cognitive and negative symptoms can be found in white matter. The significant correlations between positive symptoms in schizophrenia and diffusion and NAAc measures suggest decreased axonal density with increased glial cells and higher myelination in this subpopulation. A separate set of abnormal relationships between cognition and FA/RD, as well as with NAAc, converge to suggest that in schizophrenia, white matter microstructure supports the two core illness domains: psychosis and cognitive/negative symptoms.
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Ueda S, Niwa M, Hioki H, Sohn J, Kaneko T, Sawa A, Sakurai T. Sequence of Molecular Events during the Maturation of the Developing Mouse Prefrontal Cortex. MOLECULAR NEUROPSYCHIATRY 2015; 1:94-104. [PMID: 26457295 DOI: 10.1159/000430095] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Recent progress in psychiatric research has accumulated many mouse models relevant to developmental neuropsychiatric disorders using numerous genetic and environmental manipulations. Since the prefrontal cortex (PFC) is essential for cognitive functions whose impairments are central symptoms associated with the disorders in humans, it has become crucial to clarify altered developmental processes of PFC circuits in these mice. To that end, we aimed to understand a sequence of molecular events during normal mouse PFC development. Expression profiles for representative genes covering diverse biological processes showed that while there were little changes in genes for neuroreceptors and synaptic molecules during postnatal period, there were dramatic increases in expression of myelin-related genes and parvalbumin gene, peaking at postnatal day (P) 21 and P35, respectively. The timing of the peaks is different from one observed in the striatum. Furthermore, evaluation of the circuitry maturation by measuring extracellular glutamate in PFC revealed that sensitivity to an NMDA antagonist became adult-like pattern at P56, suggesting that some of maturation processes continue till P56. The trajectory of molecular events in the PFC maturation described here should help us to characterize how the processes are affected in model mice, an important first step for translational research.
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Affiliation(s)
- Shuhei Ueda
- Medical Innovation Center, Kyoto University Graduate School of Medicine, Kyoto 606-8501, Japan
| | - Minae Niwa
- Department of Psychiatry, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Hiroyuki Hioki
- Department of Morphological Brain Science, Kyoto University Graduate School of Medicine, Kyoto 606-8501, Japan
| | - Jaerin Sohn
- Department of Morphological Brain Science, Kyoto University Graduate School of Medicine, Kyoto 606-8501, Japan
| | - Takeshi Kaneko
- Department of Morphological Brain Science, Kyoto University Graduate School of Medicine, Kyoto 606-8501, Japan
| | - Akira Sawa
- Department of Psychiatry, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Takeshi Sakurai
- Medical Innovation Center, Kyoto University Graduate School of Medicine, Kyoto 606-8501, Japan
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Xing J, Wang C, Kimura H, Takasaki Y, Kunimoto S, Yoshimi A, Nakamura Y, Koide T, Banno M, Kushima I, Uno Y, Okada T, Aleksic B, Ikeda M, Iwata N, Ozaki N. Resequencing and association analysis of PTPRA, a possible susceptibility gene for schizophrenia and autism spectrum disorders. PLoS One 2014; 9:e112531. [PMID: 25393624 PMCID: PMC4231042 DOI: 10.1371/journal.pone.0112531] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2014] [Accepted: 09/30/2014] [Indexed: 12/30/2022] Open
Abstract
Background The PTPRA gene, which encodes the protein RPTP-α, is critical to neurodevelopment. Previous linkage studies, genome-wide association studies, controlled expression analyses and animal models support an association with both schizophrenia and autism spectrum disorders, both of which share a substantial portion of genetic risks. Methods We sequenced the protein-encoding areas of the PTPRA gene for single nucleotide polymorphisms or small insertions/deletions (InDel) in 382 schizophrenia patients. To validate their association with the disorders, rare (minor allele frequency <1%), missense mutations as well as one InDel in the 3′UTR region were then genotyped in another independent sample set comprising 944 schizophrenia patients, 336 autism spectrum disorders patients, and 912 healthy controls. Results Eight rare mutations, including 3 novel variants, were identified during the mutation-screening phase. In the following association analysis, L59P, one of the two missense mutations, was only observed among patients of schizophrenia. Additionally, a novel duplication in the 3′UTR region, 174620_174623dupTGAT, was predicted to be located within a Musashi Binding Element. Major Conclusions No evidence was seen for the association of rare, missense mutations in the PTPRA gene with schizophrenia or autism spectrum disorders; however, we did find some rare variants with possibly damaging effects that may increase the susceptibility of carriers to the disorders.
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Affiliation(s)
- Jingrui Xing
- Department of Psychiatry, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Chenyao Wang
- Department of Psychiatry, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Hiroki Kimura
- Department of Psychiatry, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Yuto Takasaki
- Department of Psychiatry, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Shohko Kunimoto
- Department of Psychiatry, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Akira Yoshimi
- Department of Psychiatry, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Yukako Nakamura
- Department of Psychiatry, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Takayoshi Koide
- Department of Psychiatry, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Masahiro Banno
- Department of Psychiatry, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Itaru Kushima
- Department of Psychiatry, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Yota Uno
- Department of Psychiatry, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Takashi Okada
- Department of Psychiatry, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Branko Aleksic
- Department of Psychiatry, Nagoya University Graduate School of Medicine, Nagoya, Japan
- * E-mail:
| | - Masashi Ikeda
- Department of Psychiatry, School of Medicine, Fujita Health University, Toyoake, Aichi, Japan
| | - Nakao Iwata
- Department of Psychiatry, School of Medicine, Fujita Health University, Toyoake, Aichi, Japan
| | - Norio Ozaki
- Department of Psychiatry, Nagoya University Graduate School of Medicine, Nagoya, Japan
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Gray matter myelination of 1555 human brains using partial volume corrected MRI images. Neuroimage 2014; 105:473-85. [PMID: 25449739 DOI: 10.1016/j.neuroimage.2014.10.054] [Citation(s) in RCA: 116] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2014] [Revised: 09/19/2014] [Accepted: 10/19/2014] [Indexed: 11/23/2022] Open
Abstract
The myelin content of the cortex changes over the human lifetime and aberrant cortical myelination is associated with diseases such as schizophrenia and multiple sclerosis. Recently magnetic resonance imaging (MRI) techniques have shown potential in differentiating between myeloarchitectonically distinct cortical regions in vivo. Here we introduce a new algorithm for correcting partial volume effects present in mm-scale MRI images which was used to investigate the myelination pattern of the cerebral cortex in 1555 clinically normal subjects using the ratio of T1-weighted (T1w) and T2-weighted (T2w) MRI images. A significant linear cross-sectional age increase in T1w/T2w estimated myelin was detected across an 18 to 35 year age span (highest value of ~ 1%/year compared to mean T1w/T2w myelin value at 18 years). The cortex was divided at mid-thickness and the value of T1w/T2w myelin calculated for the inner and outer layers separately. The increase in T1w/T2w estimated myelin occurs predominantly in the inner layer for most cortical regions. The ratio of the inner and outer layer T1w/T2w myelin was further validated using high-resolution in vivo MRI scans and also a high-resolution MRI scan of a postmortem brain. Additionally, the relationships between cortical thickness, curvature and T1w/T2w estimated myelin were found to be significant, although the relationships varied across the cortex. We discuss these observations as well as limitations of using the T1w/T2w ratio as an estimate of cortical myelin.
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Hagihara H, Ohira K, Takao K, Miyakawa T. Transcriptomic evidence for immaturity of the prefrontal cortex in patients with schizophrenia. Mol Brain 2014; 7:41. [PMID: 24886351 PMCID: PMC4066280 DOI: 10.1186/1756-6606-7-41] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2014] [Accepted: 05/20/2014] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Schizophrenia, a severe psychiatric disorder, has a lifetime prevalence of 1%. The exact mechanisms underlying this disorder remain unknown, though theories abound. Recent studies suggest that particular cell types and biological processes in the schizophrenic cortex have a pseudo-immature status in which the molecular properties partially resemble those in the normal immature brain. However, genome-wide gene expression patterns in the brains of patients with schizophrenia and those of normal infants have not been directly compared. Here, we show that the gene expression patterns in the schizophrenic prefrontal cortex (PFC) resemble those in the juvenile PFC. RESULTS We conducted a gene expression meta-analysis in which, using microarray data derived from different studies, altered expression patterns in the dorsolateral PFC (DLFC) of patients with schizophrenia were compared with those in the DLFC of developing normal human brains, revealing a striking similarity. The results were replicated in a second DLFC data set and a medial PFC (MFC) data set. We also found that about half of the genes representing the transcriptomic immaturity of the schizophrenic PFC were developmentally regulated in fast-spiking interneurons, astrocytes, and oligodendrocytes. Furthermore, to test whether medications, which often confound the results of postmortem analyses, affect on the juvenile-like gene expressions in the schizophrenic PFC, we compared the gene expression patterns showing transcriptomic immaturity in the schizophrenic PFC with those in the PFC of rodents treated with antipsychotic drugs. The results showed no apparent similarities between the two conditions, suggesting that the juvenile-like gene expression patterns observed in the schizophrenic PFC could not be accounted for by medication effects. Moreover, the developing human PFC showed a gene expression pattern similar to that of the PFC of naive Schnurri-2 knockout mice, an animal model of schizophrenia with good face and construct validity. This result also supports the idea that the transcriptomic immaturity of the schizophrenic PFC is not due to medication effects. CONCLUSIONS Collectively, our results provide evidence that pseudo-immaturity of the PFC resembling juvenile PFC may be an endophenotype of schizophrenia.
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Affiliation(s)
- Hideo Hagihara
- Division of Systems Medical Science, Institute for Comprehensive Medical Science, Fujita Health University, 1-98 Dengakugakubo, Kutsukake-cho, Toyoake, Aichi 470-1192, Japan
- CREST, JST, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan
| | - Koji Ohira
- Division of Systems Medical Science, Institute for Comprehensive Medical Science, Fujita Health University, 1-98 Dengakugakubo, Kutsukake-cho, Toyoake, Aichi 470-1192, Japan
- CREST, JST, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan
| | - Keizo Takao
- CREST, JST, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan
- Section of Behavior Patterns, Center for Genetic Analysis of Behavior, National Institute for Physiological Sciences, 38 Aza-Nishigo-naka, Myodaiji-cho, Okazaki, Aichi 444-8787, Japan
| | - Tsuyoshi Miyakawa
- Division of Systems Medical Science, Institute for Comprehensive Medical Science, Fujita Health University, 1-98 Dengakugakubo, Kutsukake-cho, Toyoake, Aichi 470-1192, Japan
- CREST, JST, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan
- Section of Behavior Patterns, Center for Genetic Analysis of Behavior, National Institute for Physiological Sciences, 38 Aza-Nishigo-naka, Myodaiji-cho, Okazaki, Aichi 444-8787, Japan
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Bitanihirwe BKY, Woo TUW. Perineuronal nets and schizophrenia: the importance of neuronal coatings. Neurosci Biobehav Rev 2014; 45:85-99. [PMID: 24709070 DOI: 10.1016/j.neubiorev.2014.03.018] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2013] [Revised: 02/19/2014] [Accepted: 03/25/2014] [Indexed: 12/17/2022]
Abstract
Schizophrenia is a complex brain disorder associated with deficits in synaptic connectivity. The insidious onset of this illness during late adolescence and early adulthood has been reported to be dependent on several key processes of brain development including synaptic refinement, myelination and the physiological maturation of inhibitory neural networks. Interestingly, these events coincide with the appearance of perineuronal nets (PNNs), reticular structures composed of components of the extracellular matrix that coat a variety of cells in the mammalian brain. Until recently, the functions of the PNN had remained enigmatic, but are now considered to be important in development of the central nervous system, neuronal protection and synaptic plasticity, all elements which have been associated with schizophrenia. Here, we review the emerging evidence linking PNNs to schizophrenia. Future studies aimed at further elucidating the functions of PNNs will provide new insights into the pathophysiology of schizophrenia leading to the identification of novel therapeutic targets with the potential to restore normal synaptic integrity in the brain of patients afflicted by this illness.
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Affiliation(s)
| | - Tsung-Ung W Woo
- Program in Cellular Neuropathology, McLean Hospital, Belmont, MA, USA; Department of Psychiatry, Harvard Medical School, Boston, MA, USA; Department of Psychiatry, Beth Israel Deaconess Medical Center, Boston, MA, USA.
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Guillozet-Bongaarts AL, Hyde TM, Dalley RA, Hawrylycz MJ, Henry A, Hof PR, Hohmann J, Jones AR, Kuan CL, Royall J, Shen E, Swanson B, Zeng H, Kleinman JE. Altered gene expression in the dorsolateral prefrontal cortex of individuals with schizophrenia. Mol Psychiatry 2014; 19:478-85. [PMID: 23528911 PMCID: PMC3965839 DOI: 10.1038/mp.2013.30] [Citation(s) in RCA: 81] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2012] [Revised: 01/24/2013] [Accepted: 02/06/2013] [Indexed: 01/31/2023]
Abstract
The underlying pathology of schizophrenia (SZ) is likely as heterogeneous as its symptomatology. A variety of cortical and subcortical regions, including the prefrontal cortex, have been implicated in its pathology, and a number of genes have been identified as risk factors for disease development. We used in situ hybridization (ISH) to examine the expression of 58 genes in the dorsolateral prefrontal cortex (DLPFC, comprised of Brodmann areas 9 and 46) from 19 individuals with a premorbid diagnosis of SZ and 33 control individuals. Genes were selected based on: (1) previous identification as risk factors for SZ; (2) cell type markers or (3) laminar markers. Cell density and staining intensity were compared in the DLPFC, as well as separately in Brodmann areas 9 and 46. The expression patterns of a variety of genes, many of which are associated with the GABAergic system, were altered in SZ when compared with controls. Additional genes, including C8orf79 and NR4A2, showed alterations in cell density or staining intensity between the groups, highlighting the need for additional studies. Alterations were, with only a few exceptions, limited to Brodmann area 9, suggesting regional specificity of pathology in the DLPFC. Our results agree with previous studies on the GABAergic involvement in SZ, and suggest that areas 9 and 46 may be differentially affected in the disease. This study also highlights additional genes that may be altered in SZ, and indicates that these potentially interesting genes can be identified by ISH and high-throughput image analysis techniques.
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Affiliation(s)
- A L Guillozet-Bongaarts
- Allen Institute for Brain Science, Seattle, WA, USA,Data Annotations and Analysis, Allen Institute for Brain Science, 551North 34th Street, Seattle, WA 98103, USA. E-mail:
| | - T M Hyde
- Lieber Institute for Brain Development, Johns Hopkins Medical Campus, Baltimore, MD, USA,Clinical Brain Disorders Branch, Genes Cognition and Psychosis Program, Intramural Research Program, NIMH, NIH, Bethesda, MD, USA,Department of Psychiatry and Behavioral Sciences, and Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - R A Dalley
- Allen Institute for Brain Science, Seattle, WA, USA
| | | | - A Henry
- Allen Institute for Brain Science, Seattle, WA, USA
| | - P R Hof
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine, Mount Sinai, New York, NY, USA
| | - J Hohmann
- Allen Institute for Brain Science, Seattle, WA, USA
| | - A R Jones
- Allen Institute for Brain Science, Seattle, WA, USA
| | - C L Kuan
- Allen Institute for Brain Science, Seattle, WA, USA
| | - J Royall
- Allen Institute for Brain Science, Seattle, WA, USA
| | - E Shen
- Allen Institute for Brain Science, Seattle, WA, USA
| | - B Swanson
- Allen Institute for Brain Science, Seattle, WA, USA
| | - H Zeng
- Allen Institute for Brain Science, Seattle, WA, USA
| | - J E Kleinman
- Lieber Institute for Brain Development, Johns Hopkins Medical Campus, Baltimore, MD, USA,Clinical Brain Disorders Branch, Genes Cognition and Psychosis Program, Intramural Research Program, NIMH, NIH, Bethesda, MD, USA
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Sasamoto A, Miyata J, Kubota M, Hirao K, Kawada R, Fujimoto S, Tanaka Y, Hazama M, Sugihara G, Sawamoto N, Fukuyama H, Takahashi H, Murai T. Global association between cortical thinning and white matter integrity reduction in schizophrenia. Schizophr Bull 2014; 40:420-7. [PMID: 23461997 PMCID: PMC3932083 DOI: 10.1093/schbul/sbt030] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Previous neuroimaging studies have revealed that both gray matter (GM) and white matter (WM) are altered in several morphological aspects in schizophrenia patients. Although several studies reported associations between GM and WM alterations in restricted regions, the existence of a global association between GM and WM pathologies is unknown. Considering the wide distribution of GM morphological changes and the profound genetic background of WM abnormalities, it would be natural to postulate a global association between pathologies of GM and WM in schizophrenia. In this investigation, we studied 35 schizophrenia patients and 35 healthy control subjects using T1-weighted magnetic resonance imaging and diffusion tensor imaging (DTI) and investigated the association between GM thickness and WM fractional anisotropy (FA) as a proxy of pathology in each tissue. To investigate cortical thickness, surface-based analysis was used. The mean cortical thickness for the whole brain was computed for each hemisphere, and group comparisons were performed. For DTI data, mean FA for the whole brain was calculated, and group comparisons were performed. Subsequently, the correlation between mean cortical thickness and mean FA was investigated. Results showed that the mean cortical thickness was significantly thinner, and the mean FA was significantly lower in schizophrenia patients. Only in the patient group the mean cortical thickness and mean FA showed significant positive correlations in both hemispheres. This correlation remained significant even after controlling for demographic and clinical variables. Thus, our results indicate that the GM and WM pathologies of schizophrenia are intertwined at the global level.
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Affiliation(s)
- Akihiko Sasamoto
- *To whom correspondence should be addressed; 54 Shogoin-Kawahara-cho, Kyoto 606-8507, Japan; tel: +81 75 751 3386, fax: +81 75 751 3246, e-mail:
| | - Jun Miyata
- Department of Psychiatry, Graduate School of Medicine, Kyoto University, Kyoto, Japan;,*To whom correspondence should be addressed; 54 Shogoin-Kawahara-cho, Kyoto 606–8507, Japan; tel: +81 75 751 3386, fax: +81 75 751 3246, e-mail:
| | - Manabu Kubota
- Department of Psychiatry, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Kazuyuki Hirao
- Department of Psychiatry, Graduate School of Medicine, Kyoto University, Kyoto, Japan;,Department of Clinical Psychology, Kyoto Bunkyo University, Uji, Japan
| | - Ryosaku Kawada
- Department of Psychiatry, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Shinsuke Fujimoto
- Department of Psychiatry, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Yusuke Tanaka
- Department of Psychiatry, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Masaaki Hazama
- Department of Psychiatry, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Genichi Sugihara
- Department of Psychiatry, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Nobukatsu Sawamoto
- Human Brain Research Center, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Hidenao Fukuyama
- Human Brain Research Center, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Hidehiko Takahashi
- Department of Psychiatry, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Toshiya Murai
- Department of Psychiatry, Graduate School of Medicine, Kyoto University, Kyoto, Japan
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Feigenson KA, Kusnecov AW, Silverstein SM. Inflammation and the two-hit hypothesis of schizophrenia. Neurosci Biobehav Rev 2014; 38:72-93. [PMID: 24247023 PMCID: PMC3896922 DOI: 10.1016/j.neubiorev.2013.11.006] [Citation(s) in RCA: 186] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Revised: 10/26/2013] [Accepted: 11/07/2013] [Indexed: 12/12/2022]
Abstract
The high societal and individual cost of schizophrenia necessitates finding better, more effective treatment, diagnosis, and prevention strategies. One of the obstacles in this endeavor is the diverse set of etiologies that comprises schizophrenia. A substantial body of evidence has grown over the last few decades to suggest that schizophrenia is a heterogeneous syndrome with overlapping symptoms and etiologies. At the same time, an increasing number of clinical, epidemiological, and experimental studies have shown links between schizophrenia and inflammatory conditions. In this review, we analyze the literature on inflammation and schizophrenia, with a particular focus on comorbidity, biomarkers, and environmental insults. We then identify several mechanisms by which inflammation could influence the development of schizophrenia via the two-hit hypothesis. Lastly, we note the relevance of these findings to clinical applications in the diagnosis, prevention, and treatment of schizophrenia.
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Affiliation(s)
- Keith A Feigenson
- Robert Wood Johnson Medical School at Rutgers, The State University of New Jersey, 675 Hoes Lane, Piscataway, NJ 08854, USA.
| | - Alex W Kusnecov
- Department of Psychology, Behavioral and Systems Neuroscience Program and Joint Graduate Program in Toxicology, Rutgers University, 52 Frelinghuysen Road, Piscataway, NJ 08854-8020, USA.
| | - Steven M Silverstein
- Robert Wood Johnson Medical School at Rutgers, The State University of New Jersey, 675 Hoes Lane, Piscataway, NJ 08854, USA; University Behavioral Health Care at Rutgers, The State University of New Jersey, 671 Hoes Lane, Piscataway, NJ 08855, USA.
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Mitterauer BJ. Pathophysiology of Schizophrenia Based on Impaired Glial-Neuronal Interactions. ACTA ACUST UNITED AC 2014. [DOI: 10.4236/ojmp.2014.32016] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Höistad M, Heinsen H, Wicinski B, Schmitz C, Hof PR. Stereological assessment of the dorsal anterior cingulate cortex in schizophrenia: absence of changes in neuronal and glial densities. Neuropathol Appl Neurobiol 2013; 39:348-61. [PMID: 22860626 DOI: 10.1111/j.1365-2990.2012.01296.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
AIMS The prefrontal and anterior cingulate cortices are implicated in schizophrenia, and many studies have assessed volume, cortical thickness, and neuronal densities or numbers in these regions. Available data, however, are rather conflicting and no clear cortical alteration pattern has been established. Changes in oligodendrocytes and white matter have been observed in schizophrenia, introducing a hypothesis about a myelin deficit as a key event in disease development. METHODS We investigated the dorsal anterior cingulate cortex (dACC) in 13 men with schizophrenia and 13 age- and gender-matched controls. We assessed stereologically the dACC volume, neuronal and glial densities, total neurone and glial numbers, and glia/neurone index (GNI) in both layers II-III and V-VI. RESULTS We observed no differences in neuronal or glial densities. No changes were observed in dACC cortical volume, total neurone numbers, and total glial numbers in schizophrenia. This contrasts with previous findings and suggests that the dACC may not undergo as severe changes in schizophrenia as is generally believed. However, we observed higher glial densities in layers V-VI than in layers II-III in both controls and patients with schizophrenia, pointing to possible layer-specific effects on oligodendrocyte distribution during development. CONCLUSIONS Using rigorous stereological methods, we demonstrate a seemingly normal cortical organization in an important neocortical area for schizophrenia, emphasizing the importance of such morphometric approaches in quantitative neuropathology. We discuss the significance of subregion- and layer-specific alterations in the development of schizophrenia, and the discrepancies between post mortem histopathological studies and in vivo brain imaging findings in patients.
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Affiliation(s)
- M Höistad
- Fishberg Department of Neuroscience and Friedman Brain Institute, Mount Sinai School of Medicine, New York, New York, USA
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Mosebach J, Keilhoff G, Gos T, Schiltz K, Schoeneck L, Dobrowolny H, Mawrin C, Müller S, Schroeter ML, Bernstein HG, Bogerts B, Steiner J. Increased nuclear Olig1-expression in the pregenual anterior cingulate white matter of patients with major depression: a regenerative attempt to compensate oligodendrocyte loss? J Psychiatr Res 2013; 47:1069-79. [PMID: 23615187 DOI: 10.1016/j.jpsychires.2013.03.018] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2012] [Revised: 02/17/2013] [Accepted: 03/19/2013] [Indexed: 12/27/2022]
Abstract
BACKGROUND Structural and functional oligodendrocyte deficits as well as impaired myelin integrity have been described in affective disorders and schizophrenia, and may disturb the connectivity between disease-relevant brain regions. Olig1, an oligodendroglial transcription factor, might be important in this context, but has not been systematically studied so far. METHODS Nissl- and Olig1-stained oligodendrocytes were quantified in the pregenual anterior cingulate (pACC)/dorsolateral prefrontal cortex (DLPFC), and adjacent white matter of patients with major depressive disorder (MDD, n = 9), bipolar disorder (BD, n = 8), schizophrenia (SZ, n = 13), and matched controls (n = 16). Potential downstream effects of increased Olig1-expression were analyzed. Antidepressant drug effects on Olig1-expression were further explored in OLN-93 oligodendrocyte cultures. RESULTS Nissl-stainings of both white matter regions showed a 19-27% reduction of total oligodendrocyte densities in MDD and BD, but not in SZ. In contrast, nuclear Olig1-immunoreactivity was elevated in MDD in the pACC-adjacent white matter (left: p = 0.008; right: p = 0.018); this effect tended to increase with antidepressant dosage (r = 0.631, p = 0.069). This reactive increase of Olig1 was confirmed by partly dose-dependent effects of imipramine and amitriptyline in oligodendrocyte cultures. Correspondingly, MBP expression in the pACC-adjacent white matter tended to increase with antidepressant dosage (r = 0.637, p = 0.065). Other tested brain regions showed no diagnosis-dependent differences regarding Olig1-immunoreactivity. CONCLUSIONS Since nuclear Olig1-expression marks oligodendrocyte precursor cells, its increased expression along with reduced total oligodendrocyte densities (Nissl-stained) in the pACC-adjacent white matter of MDD patients might indicate a (putatively medication-boosted) regenerative attempt to compensate oligodendrocyte loss.
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Affiliation(s)
- Jennifer Mosebach
- Department of Psychiatry, University of Magdeburg, Magdeburg, Germany
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Johnsen E, Hugdahl K, Fusar-Poli P, Kroken RA, Kompus K. Neuropsychopharmacology of auditory hallucinations: insights from pharmacological functional MRI and perspectives for future research. Expert Rev Neurother 2013; 13:23-36. [PMID: 23253389 DOI: 10.1586/ern.12.147] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Experiencing auditory verbal hallucinations is a prominent symptom in schizophrenia that also occurs in subjects at enhanced risk for psychosis and in the general population. Drug treatment of auditory hallucinations is challenging, because the current understanding is limited with respect to the neural mechanisms involved, as well as how CNS drugs, such as antipsychotics, influence the subjective experience and neurophysiology of hallucinations. In this article, the authors review studies of the effect of antipsychotic medication on brain activation as measured with functional MRI in patients with auditory verbal hallucinations. First, the authors examine the neural correlates of ongoing auditory hallucinations. Then, the authors critically discuss studies addressing the antipsychotic effect on the neural correlates of complex cognitive tasks. Current evidence suggests that blood oxygen level-dependant effects of antipsychotic drugs reflect specific, regional effects but studies on the neuropharmacology of auditory hallucinations are scarce. Future directions for pharmacological neuroimaging of auditory hallucinations are discussed.
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Affiliation(s)
- Erik Johnsen
- Division of Psychiatry, Haukeland University Hospital, Bergen, Norway.
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Lochman J, Balcar VJ, Sťastný F, Serý O. Preliminary evidence for association between schizophrenia and polymorphisms in the regulatory Regions of the ADRA2A, DRD3 and SNAP-25 Genes. Psychiatry Res 2013; 205:7-12. [PMID: 22940547 DOI: 10.1016/j.psychres.2012.08.003] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/22/2012] [Revised: 07/18/2012] [Accepted: 08/03/2012] [Indexed: 10/27/2022]
Abstract
The results of linkage and candidate gene association studies have led to a range of hypotheses about the pathogenesis of schizophrenia. We limited our study to polymorphisms in candidate genes involved in dopaminergic and noradrenergic systems, and in the 25KDa synaptosomal-associated protein (SNAP-25) gene that is related to neurotransmitter exocytosis. Eight single nucleotide polymorphisms (SNPs) in regulating or coding regions of genes for the alpha-2A adrenergic receptor (ADRA2A), dopamine receptors D1 and D3 (DRD1 and DRD3), dopamine β-hydroxylase (DBH) and SNAP-25 were genotyped in male patients with schizophrenia (n=192) and in healthy controls (n=213). These polymorphisms were previously associated with schizophrenia. The allelic association between schizophrenia and ADRA2A rs1800544 polymorphism, SNAP-25 rs1503112 polymorphism, and DRD3 rs6280 polymorphism was found in our study. However, only observations for rs1503112 survived correction for multiple testing. Association was also evaluated by considering the polymorphisms as interactions; in this case, a likelihood ratio test (LRT) revealed evidence for association with schizophrenia in four polymorphism combinations: two DRD3*SNAP-25 combinations (rs6280*rs3746544 and rs6280*rs3746544, P=0.02), one ADRA2A*SNAP25 combination (rs1800544*rs3746544) and one ADRA2A*DBH combination (rs1800544*rs2519152). Our results are in agreement with the previously proposed role of DNA polymorphisms involved in dopaminergic, noradrenergic and synaptic functions in the pathogenesis of schizophrenia. Further relevant studies including larger sample size and more markers are needed to confirm our results.
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Affiliation(s)
- Jan Lochman
- Department of Biochemistry, Faculty of Science, Masaryk University, Brno, Czech Republic.
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Schmitt A, Reich-Erkelenz D, Gebicke-Härter P, Falkai P. Estudos transcriptômicos no contexto da conectividade perturbada em esquizofrenia. ACTA ACUST UNITED AC 2012. [DOI: 10.1590/s0101-60832012005000001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Esquizofrenia é uma severa doença neurobiológica com fatores genéticos e ambientais desempenhando um papel na fisiopatologia. Diversas regiões cerebrais têm sido implicadas no processo da doença e estão conectadas em complexos circuitos neuronais. Nos níveis molecular e celular, a conectividade afetada entre essas regiões, envolvendo mielinização disfuncional dos axônios neuronais, bem como as alterações no nível sináptico e metabolismo energético levando a distúrbios na plasticidade sináptica, são os maiores achados em estudos post-mortem. Estudos de microarranjos investigando a expressão gênica contribuíram para os achados de alterações em vias complexas em regiões cerebrais relevantes na esquizofrenia. Além disso, estudos utilizando microdissecção e captura a laser permitiram a investigação da expressão gênica em grupos específicos de neurônios. Entretanto, deve ser mantido em mente que em estudos post-mortem, confusos efeitos de medicação, qualidade de RNAm, bem como capacidade de mecanismos regenerativos neuroplásticos do cérebro em indivíduos com história de vida de esquizofrenia, podem influenciar o complexo padrão de alterações no nível molecular. Apesar dessas limitações, estudos transcriptômicos livres de hipóteses em tecido cerebral de pacientes esquizofrênicos oferecem uma possibilidade única para aprender mais sobre os mecanismos subjacentes, levando a novas ópticas da fisiopatologia da doença.
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Affiliation(s)
- Andrea Schmitt
- Universidade de Göttingen, Alemanha; Universidade Ludwig Maximilians, Alemanha; Universidade de São Paulo, Brasil
| | | | | | - Peter Falkai
- Universidade de Göttingen, Alemanha; Universidade Ludwig Maximilians, Alemanha
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Rosenbluth J, Bobrowski-Khoury N. Structural bases for central nervous system malfunction in the quaking mouse: dysmyelination in a potential model of schizophrenia. J Neurosci Res 2012; 91:374-81. [PMID: 23224912 DOI: 10.1002/jnr.23167] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2012] [Revised: 09/20/2012] [Accepted: 10/08/2012] [Indexed: 11/07/2022]
Abstract
The dysmyelinating mouse mutant quaking (qk) is thought to be a model of schizophrenia based on diminution of CNS myelin (Andreone et al., 2007) and downregulation of the Qk gene (Haroutunian et al., 2006) in the brains of schizophrenic patients. The purpose of this study was to identify specific structural defects in the qk mouse CNS that could compromise physiologic function and that in humans might account for some of the cognitive defects characteristic of schizophrenia. Ultrastructural analysis of qk mouse CNS myelinated fibers shows abnormalities in nodal, internodal, and paranodal regions, including marked variation in myelin thickness among neighboring fibers, spotty disruption of paranodal junctions, abnormal distribution of nodal and paranodal ion channel complexes, generalized thinning and incompactness of myelin, and on many axonal profiles complete absence of myelin. These structural defects are likely to cause abnormalities in conduction velocity, synchrony of activation, temporal ordering of signals, and other physiological parameters. We conclude that the structural abnormalities described are likely to be responsible for significant functional impairment both in the qk mouse CNS and in the human CNS with comparable myelin pathology.
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Affiliation(s)
- J Rosenbluth
- Department of Physiology and Neuroscience, New York University School of Medicine, New York, New York 10016, USA.
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Takahashi N, Sakurai T. Roles of glial cells in schizophrenia: possible targets for therapeutic approaches. Neurobiol Dis 2012; 53:49-60. [PMID: 23146995 DOI: 10.1016/j.nbd.2012.11.001] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2012] [Revised: 09/30/2012] [Accepted: 11/01/2012] [Indexed: 12/20/2022] Open
Abstract
Glial cells consisting of oligodendrocytes, astrocytes, microglia, and NG2 positive cells are major cell populations in the central nervous system, number-wise. They function as effectors and modulators of neurodevelopment through a wide variety of neuron-glial cell interactions in brain development and functions. Glial cells can be affected by both genetic and environmental factors, leading to their dysfunctions in supporting neuronal development and functions. These in turn can affect neuronal cells, causing alterations at the circuitry level that manifest as behavioral characteristics associated with schizophrenia in late teens-early twenties. Glial cells are also involved in neuroinflammatory processes, which sometimes have deleterious effects on the normal brain development. If the glial involvement plays significant roles in schizophrenia, the processes involving glial cells can become possible therapeutic targets for schizophrenia. A number of known antipsychotics are shown to have beneficial effects on glial cells, but other drugs targeting glial cell functions may also have therapeutic effects on schizophrenia. The latter can be taken into consideration for future drug development for schizophrenia.
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Affiliation(s)
- Nagahide Takahashi
- Department of Psychiatry, Nagoya University Graduate School of Medicine, Showa-ku, Nagoya, Japan
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Abstract
Nerve myelination facilitates saltatory action potential conduction and exhibits spatiotemporal variation during development associated with the acquisition of behavioral and cognitive maturity. Although human cognitive development is unique, it is not known whether the ontogenetic progression of myelination in the human neocortex is evolutionarily exceptional. In this study, we quantified myelinated axon fiber length density and the expression of myelin-related proteins throughout postnatal life in the somatosensory (areas 3b/3a/1/2), motor (area 4), frontopolar (prefrontal area 10), and visual (areas 17/18) neocortex of chimpanzees (N = 20) and humans (N = 33). Our examination revealed that neocortical myelination is developmentally protracted in humans compared with chimpanzees. In chimpanzees, the density of myelinated axons increased steadily until adult-like levels were achieved at approximately the time of sexual maturity. In contrast, humans displayed slower myelination during childhood, characterized by a delayed period of maturation that extended beyond late adolescence. This comparative research contributes evidence crucial to understanding the evolution of human cognition and behavior, which arises from the unfolding of nervous system development within the context of an enriched cultural environment. Perturbations of normal developmental processes and the decreased expression of myelin-related molecules have been related to psychiatric disorders such as schizophrenia. Thus, these species differences suggest that the human-specific shift in the timing of cortical maturation during adolescence may have implications for vulnerability to certain psychiatric disorders.
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Confounders of excessive brain volume loss in schizophrenia. Neurosci Biobehav Rev 2012; 37:2418-23. [PMID: 23000300 DOI: 10.1016/j.neubiorev.2012.09.006] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2012] [Revised: 08/15/2012] [Accepted: 09/11/2012] [Indexed: 11/23/2022]
Abstract
There is convincing evidence that schizophrenia is characterised by progressive brain volume changes during the course of the illness. In a large longitudinal study it was shown that different age-related trajectories of brain tissue loss are present in patients compared to healthy subjects, suggesting that brain maturation that occurs in the third and fourth decade of life is abnormal in schizophrenia. However, studies show that medication intake and cannabis use are important confounding factors when interpreting brain volume (change) abnormalities. Indeed, continues use of cannabis, but not cigarette smoking, is associated to a more pronounced loss of grey matter in the anterior cingulated and the prefrontal cortex. Atypical antipsychotics have been found to be related to smaller decreases in tissue loss. Moreover, independent of antipsychotic medication intake, the brain volume abnormalities appear associated to the outcome of the illness.
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Increased density of prohibitin-immunoreactive oligodendrocytes in the dorsolateral prefrontal white matter of subjects with schizophrenia suggests extraneuronal roles for the protein in the disease. Neuromolecular Med 2012; 14:270-80. [PMID: 22711522 DOI: 10.1007/s12017-012-8185-y] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2012] [Accepted: 06/01/2012] [Indexed: 12/22/2022]
Abstract
Prohibitin has previously been implicated in the synaptic pathology of schizophrenia. The recently discovered abundant expression of prohibitin in human prefrontal oligodendrocytes raises the issue, whether this protein might also be part of the well-known white matter abnormalities in schizophrenia. Hence, post-mortem brains of ten patients with schizophrenia and ten matched control cases were investigated. Using a direct, 3D-counting technique we morphometrically analyzed the number and density of prohibitin-immunoreactive oligodendroglial cells in the left and right dorsolateral, anterior cingulate, and orbitofrontal cortex white matter. Additionally, we studied the prohibitin expression in different neuronal and non-neuronal cell populations in rat cell cultures. We could confirm the strong expression of prohibitin in oligodendrocytes. Intracellularly, the protein was localized to mitochondria and some cell nuclei. In schizophrenia, the numerical density of prohibitin-expressing oligodendrocytes was significantly increased in the right dorsolateral white matter area. Taking into consideration the dual intracellular localization of prohibitin in oligodendrocyte mitochondria and cell nuclei, one may suggest an involvement of the protein in mitochondrial dysfunction and/or cycle abnormalities in schizophrenia.
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das Neves Duarte JM, Kulak A, Gholam-Razaee MM, Cuenod M, Gruetter R, Do KQ. N-acetylcysteine normalizes neurochemical changes in the glutathione-deficient schizophrenia mouse model during development. Biol Psychiatry 2012; 71:1006-14. [PMID: 21945305 DOI: 10.1016/j.biopsych.2011.07.035] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2011] [Revised: 07/11/2011] [Accepted: 07/29/2011] [Indexed: 12/21/2022]
Abstract
BACKGROUND Glutathione (GSH) is the major cellular redox-regulator and antioxidant. Redox-imbalance due to genetically impaired GSH synthesis is among the risk factors for schizophrenia. Here we used a mouse model with chronic GSH deficit induced by knockout (KO) of the key GSH-synthesizing enzyme, glutamate-cysteine ligase modulatory subunit (GCLM). METHODS With high-resolution magnetic resonance spectroscopy at 14.1 T, we determined the neurochemical profile of GCLM-KO, heterozygous, and wild-type mice in anterior cortex throughout development in a longitudinal study design. RESULTS Chronic GSH deficit was accompanied by an elevation of glutamine (Gln), glutamate (Glu), Gln/Glu, N-acetylaspartate, myo-Inositol, lactate, and alanine. Changes were predominantly present at prepubertal ages (postnatal days 20 and 30). Treatment with N-acetylcysteine from gestation on normalized most neurochemical alterations to wild-type level. CONCLUSIONS Changes observed in GCLM-KO anterior cortex, notably the increase in Gln, Glu, and Gln/Glu, were similar to those reported in early schizophrenia, emphasizing the link between redox imbalance and the disease and validating the model. The data also highlight the prepubertal period as a sensitive time for redox-related neurochemical changes and demonstrate beneficial effects of early N-acetylcysteine treatment. Moreover, the data demonstrate the translational value of magnetic resonance spectroscopy to study brain disease in preclinical models.
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Affiliation(s)
- Joao Miguel das Neves Duarte
- Laboratory for Functional and Metabolic Imaging, Center for Biomedical Imaging, Ecole Polytechnique Federale, University Hospital Lausanne, Switzerland.
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Bennett M. Schizophrenia: susceptibility genes, dendritic-spine pathology and gray matter loss. Prog Neurobiol 2011; 95:275-300. [DOI: 10.1016/j.pneurobio.2011.08.003] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2011] [Revised: 08/12/2011] [Accepted: 08/15/2011] [Indexed: 02/01/2023]
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Loss of function studies in mice and genetic association link receptor protein tyrosine phosphatase α to schizophrenia. Biol Psychiatry 2011; 70:626-35. [PMID: 21831360 PMCID: PMC3176920 DOI: 10.1016/j.biopsych.2011.06.016] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/18/2010] [Revised: 05/17/2011] [Accepted: 06/02/2011] [Indexed: 01/06/2023]
Abstract
BACKGROUND Solid evidence links schizophrenia (SZ) susceptibility to neurodevelopmental processes involving tyrosine phosphorylation-mediated signaling. Mouse studies implicate the Ptpra gene, encoding protein tyrosine phosphatase RPTPα, in the control of radial neuronal migration, cortical cytoarchitecture, and oligodendrocyte differentiation. The human gene encoding RPTPα, PTPRA, maps to a chromosomal region (20p13) associated with susceptibility to psychotic illness. METHODS We characterized neurobehavioral parameters, as well as gene expression in the central nervous system, of mice with a null mutation in the Ptpra gene. We searched for genetic association between polymorphisms in PTPRA and schizophrenia risk (two independent cohorts, 1420 cases and 1377 controls), and we monitored PTPRA expression in prefrontal dorsolateral cortex of SZ patients (35 cases, 2 control groups of 35 cases). RESULTS We found that Ptpra⁻/⁻ mice reproduce neurobehavioral endophenotypes of human SZ: sensitization to methamphetamine-induced hyperactivity, defective sensorimotor gating, and defective habituation to a startle response. Ptpra loss of function also leads to reduced expression of multiple myelination genes, mimicking the hypomyelination-associated changes in gene expression observed in postmortem patient brains. We further report that a polymorphism at the PTPRA locus is genetically associated with SZ, and that PTPRA mRNA levels are reduced in postmortem dorsolateral prefrontal cortex of subjects with SZ. CONCLUSIONS The implication of this well-studied signaling protein in SZ risk and endophenotype manifestation provides novel entry points into the etiopathology of this disease.
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Marx C, Bradford D, Hamer R, Naylor J, Allen T, Lieberman J, Strauss J, Kilts J. Pregnenolone as a novel therapeutic candidate in schizophrenia: emerging preclinical and clinical evidence. Neuroscience 2011; 191:78-90. [DOI: 10.1016/j.neuroscience.2011.06.076] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2011] [Revised: 05/30/2011] [Accepted: 06/28/2011] [Indexed: 10/18/2022]
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Xu H, Li XM. White matter abnormalities and animal models examining a putative role of altered white matter in schizophrenia. SCHIZOPHRENIA RESEARCH AND TREATMENT 2011; 2011:826976. [PMID: 22937274 PMCID: PMC3420616 DOI: 10.1155/2011/826976] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/20/2011] [Accepted: 06/21/2011] [Indexed: 11/18/2022]
Abstract
Schizophrenia is a severe mental disorder affecting about 1% of the population worldwide. Although the dopamine (DA) hypothesis is still keeping a dominant position in schizophrenia research, new advances have been emerging in recent years, which suggest the implication of white matter abnormalities in schizophrenia. In this paper, we will briefly review some of recent human studies showing white matter abnormalities in schizophrenic brains and altered oligodendrocyte-(OL-) and myelin-related genes in patients with schizophrenia and will consider abnormal behaviors reported in patients with white matter diseases. Following these, we will selectively introduce some animal models examining a putative role of white matter abnormalities in schizophrenia. The emphasis will be put on the cuprizone (CPZ) model. CPZ-fed mice show demyelination and OLs loss, display schizophrenia-related behaviors, and have higher DA levels in the prefrontal cortex. These features suggest that the CPZ model is a novel animal model of schizophrenia.
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Affiliation(s)
- Haiyun Xu
- Department of Anatomy, Southern Illinois University Carbondale, Carbondale, IL 62901, USA
| | - Xin-Min Li
- Department of Psychiatry, Faculty of Medicine, University of Manitoba, Winnipeg, MB, Canada R3T 2N2
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Mitterauer BJ, Kofler-Westergren B. Possible effects of synaptic imbalances on oligodendrocyte-axonic interactions in schizophrenia: a hypothetical model. Front Psychiatry 2011; 2:15. [PMID: 21647404 PMCID: PMC3102422 DOI: 10.3389/fpsyt.2011.00015] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2011] [Accepted: 03/28/2011] [Indexed: 11/13/2022] Open
Abstract
A model of glial-neuronal interactions is proposed that could be explanatory for the demyelination identified in brains with schizophrenia. It is based on two hypotheses: (1) that glia-neuron systems are functionally viable and important for normal brain function, and (2) that disruption of this postulated function disturbs the glial categorization function, as shown by formal analysis. According to this model, in schizophrenia receptors on astrocytes in glial-neuronal synaptic units are not functional, loosing their modulatory influence on synaptic neurotransmission. Hence, an unconstrained neurotransmission flux occurs that hyperactivates the axon and floods the cognate receptors of neurotransmitters on oligodendrocytes. The excess of neurotransmitters may have a toxic effect on oligodendrocytes and myelin, causing demyelination. In parallel, an increasing impairment of axons may disconnect neuronal networks. It is formally shown how oligodendrocytes normally categorize axonic information processing via their processes. Demyelination decomposes the oligodendrocyte-axonic system making it incapable to generate categories of information. This incoherence may be responsible for symptoms of disorganization in schizophrenia, such as thought disorder, inappropriate affect and incommunicable motor behavior. In parallel, the loss of oligodendrocytes affects gap junctions in the panglial syncytium, presumably responsible for memory impairment in schizophrenia.
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Affiliation(s)
- Bernhard J. Mitterauer
- Volitronics – Institute for Basic Research, Psychopathology and Brain PhilosophyWals/Salzburg, Austria
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Molina V, Papiol S, Sanz J, Rosa A, Arias B, Fatjó-Vilas M, Calama J, Hernández AI, Bécker J, Fañanás L. Convergent evidence of the contribution of TP53 genetic variation (Pro72Arg) to metabolic activity and white matter volume in the frontal lobe in schizophrenia patients. Neuroimage 2011; 56:45-51. [PMID: 21296169 DOI: 10.1016/j.neuroimage.2011.01.076] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2010] [Revised: 01/13/2011] [Accepted: 01/28/2011] [Indexed: 10/18/2022] Open
Abstract
Abnormalities in white matter (WM) volumes and integrity in schizophrenia, together with post-mortem studies showing reduced expression of oligodendrocyte/myelination genes and apoptotic processes taking place in oligodendrocytes, suggest the interest of major regulators of apoptosis as candidate genes for some features related to myelin integrity in schizophrenia. Protein p53, encoded by TP53 gene, has a central role in the control of apoptosis and is involved in oligodendrocyte development. TP53 gene polymorphisms may account for variability in WM features, metabolic activity and biochemical markers of neuronal integrity and membrane turnover. Pro72Arg and Ins16bp polymorphisms at TP53 gene were analyzed in 20 DSM-IV schizophrenia patients. T1/T2-weighted sequences of these patients were acquired using a 1.5T Philips Gyroscan system. Scans were transformed into Talairach space and segmented into gray matter (GM), WM and cerebrospinal fluid (CSF) using Statistical Parametric Mapping under a ROI approach. Likewise dorsolateral prefrontal cortex (DLPFC) metabolic activity was measured using a procedure based on MRI/PET image fusion. In 13 of these patients proton magnetic resonance spectroscopy was used to examine N-acetylaspartate (NAA), creatine (Cr) and choline (Cho) levels in dorsolateral-medial prefrontal cortex (DLMPFC). MRI data were adjusted for age and brain volume using regression parameters from a healthy control group (n=45). Patients Pro/Arg heterozygous (Pro72Arg polymorphism) showed a generalized deficit in whole-brain WM that was especially prominent in frontal lobe and a lower metabolic activity in the DLPFC as compared to Pro/Pro homozygous. Pro/Arg subjects also showed decreased NAA/Cho and increased Cho/Cr ratios in right DLMPFC. TP53 genetic variability influences WM volumes in frontal lobes and it seems to modulate the metabolic activity in this region. Our results suggest that TP53 might influence aspects of myelin and white matter integrity which may account for some of the frontal dysfunction features commonly described in these patients.
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Affiliation(s)
- Vicente Molina
- Department of Psychiatry, Hospital Clínico de Salamanca, Salamanca, Spain.
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