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Gangadin SS, Mandl RCW, de Witte LD, van Haren NEM, Schutte MJL, Begemann MJH, Kahn RS, Sommer IEC. Lower fractional anisotropy without evidence for neuro-inflammation in patients with early-phase schizophrenia spectrum disorders. Schizophr Res 2024; 264:557-566. [PMID: 36577563 DOI: 10.1016/j.schres.2022.12.009] [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: 06/09/2022] [Revised: 12/05/2022] [Accepted: 12/07/2022] [Indexed: 12/28/2022]
Abstract
Various lines of research suggest immune dysregulation as a potential therapeutic target for negative and cognitive symptoms in schizophrenia spectrum disorders (SSD). Immune dysregulation would lead to higher extracellular free-water (EFW) in cerebral white matter (WM), which may partially underlie the frequently reported lower fractional anisotropy (FA) in SSD. We aim to investigate differences in EFW concentrations - a presumed proxy for neuro-inflammation - between early-phase SSD patients (n = 55) and healthy controls (HC; n = 37), and to explore immunological and cognitive correlates. To increase specificity for EFW, we study several complementary magnetic resonance imaging contrasts that are sensitive to EFW. FA, mean diffusivity (MD), magnetization transfer ratio (MTR), myelin water fraction (MWF) and quantitative T1 and T2 were calculated from diffusion-weighted imaging (DWI), magnetization transfer imaging (MTI) and multicomponent driven equilibrium single-pulse observation of T1/T2 (mcDESPOT). For each measure, WM skeletons were constructed with tract-based spatial statistics. Multivariate SSD-HC comparisons with WM skeletons and their average values (i.e. global WM) were not statistically significant. In voxel-wise analyses, FA was significantly lower in SSD in the genu of the corpus callosum and in the left superior longitudinal fasciculus (p < 0.04). Global WM measures did not correlate with immunological markers (i.e. IL1-RA, IL-6, IL-8, IL-10 and CRP) or cognition in HC and SSD after corrections for multiple comparisons. We confirmed lower FA in early-phase SSD patients. However, nonFA measures did not provide additional evidence for immune dysregulation or for higher EFW as the primary mechanism underlying the reported lower FA values in SSD.
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Affiliation(s)
- Shiral S Gangadin
- Section Cognitive Neuroscience, Department of Biomedical Sciences of Cells & Systems, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands.
| | - René C W Mandl
- Section Cognitive Neuroscience, Department of Biomedical Sciences of Cells & Systems, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Lot D de Witte
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York City, NY, USA.
| | - Neeltje E M van Haren
- Department of Child and Adolescent Psychiatry/Psychology, Erasmus University Medical Center-Sophia Children's Hospital, Rotterdam, the Netherlands.
| | - Maya J L Schutte
- Section Cognitive Neuroscience, Department of Biomedical Sciences of Cells & Systems, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands.
| | - Marieke J H Begemann
- Section Cognitive Neuroscience, Department of Biomedical Sciences of Cells & Systems, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands.
| | - René S Kahn
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York City, NY, USA.
| | - Iris E C Sommer
- Section Cognitive Neuroscience, Department of Biomedical Sciences of Cells & Systems, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands.
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2
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Scheepstra KWF, Mizee MR, van Scheppingen J, Adelia A, Wever DD, Mason MRJ, Dubbelaar ML, Hsiao CC, Eggen BJL, Hamann J, Huitinga I. Microglia Transcriptional Profiling in Major Depressive Disorder Shows Inhibition of Cortical Gray Matter Microglia. Biol Psychiatry 2023; 94:619-629. [PMID: 37121366 DOI: 10.1016/j.biopsych.2023.04.020] [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: 02/15/2022] [Revised: 02/01/2023] [Accepted: 04/17/2023] [Indexed: 05/02/2023]
Abstract
BACKGROUND Microglia have been implicated in the pathophysiology of major depressive disorder (MDD), but information on biological mechanisms is limited. Therefore, we investigated the gene expression profile of microglial cells in relation to neuronal regulators of microglia activity in well-characterized MDD and control autopsy brains. METHODS Pure, intact microglia were isolated at brain autopsy from occipital cortex gray matter (GM) and corpus callosum white matter of 13 donors with MDD and 10 age-matched control donors for RNA sequencing. Top differentially expressed genes were validated using immunohistochemistry staining. Because gene expression changes were only detected in GM microglia, neuronal regulators of microglia were investigated in cortical tissue and synaptosomes from the cortex by reverse transcriptase-quantitative polymerase chain reaction and Western blot. RESULTS Transcriptome analysis revealed 92 genes differentially expressed in microglia isolated from GM, but none in microglia from white matter in donors with MDD, compared with control donors. Of these, 81 genes were less abundantly expressed in GM in MDD, including CD163, MKI67, SPP1, CD14, FCGR1A/C, and C1QA/B/C. Accordingly, pathways related to effector mechanisms, such as the complement system and phagocytosis, were differentially regulated in GM microglia in MDD. Immunohistochemistry staining revealed significantly lower expression of CD163 protein in MDD. Whole tissue analysis showed an increase in CD200 (p = .0009) and CD47 (p = .068) messenger RNA, and CD47 protein was significantly elevated (p = .0396) in synaptic fractions of MDD cases. CONCLUSIONS Transcriptional profiling indicates an immune-suppressed microglial phenotype in MDD that is possibly caused by neuronal regulation.
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Affiliation(s)
- Karel W F Scheepstra
- Neuroimmunology Research Group, Netherlands Institute for Neuroscience, Amsterdam, the Netherlands; Psychiatric Program of the Netherlands Brain Bank, Netherlands Institute for Neuroscience, Amsterdam, the Netherlands; Department of Psychiatry, Amsterdam University Medical Centers, Amsterdam Neuroscience, Amsterdam, the Netherlands.
| | - Mark R Mizee
- Neuroimmunology Research Group, Netherlands Institute for Neuroscience, Amsterdam, the Netherlands; Psychiatric Program of the Netherlands Brain Bank, Netherlands Institute for Neuroscience, Amsterdam, the Netherlands
| | - Jackelien van Scheppingen
- Neuroimmunology Research Group, Netherlands Institute for Neuroscience, Amsterdam, the Netherlands; Psychiatric Program of the Netherlands Brain Bank, Netherlands Institute for Neuroscience, Amsterdam, the Netherlands
| | - Adelia Adelia
- Psychiatric Program of the Netherlands Brain Bank, Netherlands Institute for Neuroscience, Amsterdam, the Netherlands
| | - Dennis D Wever
- Neuroimmunology Research Group, Netherlands Institute for Neuroscience, Amsterdam, the Netherlands; Psychiatric Program of the Netherlands Brain Bank, Netherlands Institute for Neuroscience, Amsterdam, the Netherlands
| | - Matthew R J Mason
- Neuroimmunology Research Group, Netherlands Institute for Neuroscience, Amsterdam, the Netherlands
| | - Marissa L Dubbelaar
- Department of Biomedical Sciences of Cells and Systems, Section Molecular Neurobiology, University Medical Center Groningen, Groningen, the Netherlands
| | - Cheng-Chih Hsiao
- Neuroimmunology Research Group, Netherlands Institute for Neuroscience, Amsterdam, the Netherlands; Department of Experimental Immunology, Amsterdam Institute for Infection and Immunity, Amsterdam University Medical Centers, Amsterdam, the Netherlands
| | - Bart J L Eggen
- Department of Biomedical Sciences of Cells and Systems, Section Molecular Neurobiology, University Medical Center Groningen, Groningen, the Netherlands
| | - Jörg Hamann
- Neuroimmunology Research Group, Netherlands Institute for Neuroscience, Amsterdam, the Netherlands; Department of Experimental Immunology, Amsterdam Institute for Infection and Immunity, Amsterdam University Medical Centers, Amsterdam, the Netherlands
| | - Inge Huitinga
- Neuroimmunology Research Group, Netherlands Institute for Neuroscience, Amsterdam, the Netherlands; Psychiatric Program of the Netherlands Brain Bank, Netherlands Institute for Neuroscience, Amsterdam, the Netherlands; Swammerdam Institute for Life Sciences, Center for Neuroscience, University of Amsterdam, Amsterdam, the Netherlands.
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3
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Ai YW, Du Y, Chen L, Liu SH, Liu QS, Cheng Y. Brain Inflammatory Marker Abnormalities in Major Psychiatric Diseases: a Systematic Review of Postmortem Brain Studies. Mol Neurobiol 2023; 60:2116-2134. [PMID: 36600081 DOI: 10.1007/s12035-022-03199-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2022] [Accepted: 12/23/2022] [Indexed: 01/06/2023]
Abstract
Schizophrenia (SCZ), bipolar disorder (BD), and major depressive disorder (MDD) are common neuropsychiatric disorders that lead to neuroinflammation in the pathogenesis. It is possible to further explore the connection between inflammation in the brain and SCZ, BD, and MDD. Therefore, we systematically reviewed PubMed and Web of Science on brain inflammatory markers measured in SCZ, BD, and MDD postmortem brains. Out of 2166 studies yielded by the search, 46 studies met the inclusion criteria in SCZ, BD, and MDD postmortem brains. The results were variable across inflammatory markers. For example, 26 studies were included to measure the differential expression between SCZ and control subjects. Similarly, seven of the included studies measured the differential expression of inflammatory markers in patients with BD. The heterogeneity from the included studies is not clear at present, which may be caused by several factors, including the measured brain region, disease stage, brain source, medication, and other factors.
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Affiliation(s)
- Yang-Wen Ai
- School of Pharmacy, Center on Translational Neuroscience, Minzu University of China, Haidian District, 27 Zhongguancun South St, 100081, Beijing, China
| | - Yang Du
- School of Pharmacy, Center on Translational Neuroscience, Minzu University of China, Haidian District, 27 Zhongguancun South St, 100081, Beijing, China
| | - Lei Chen
- School of Pharmacy, Center on Translational Neuroscience, Minzu University of China, Haidian District, 27 Zhongguancun South St, 100081, Beijing, China
| | - Shu-Han Liu
- School of Pharmacy, Center on Translational Neuroscience, Minzu University of China, Haidian District, 27 Zhongguancun South St, 100081, Beijing, China
| | - Qing-Shan Liu
- School of Pharmacy, Center on Translational Neuroscience, Minzu University of China, Haidian District, 27 Zhongguancun South St, 100081, Beijing, China.
| | - Yong Cheng
- School of Pharmacy, Center on Translational Neuroscience, Minzu University of China, Haidian District, 27 Zhongguancun South St, 100081, Beijing, China. .,Institute of National Security, Minzu University of China, Haidian District, 27 Zhongguancun South St, 100081, Beijing, China.
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4
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Social interaction, psychotic disorders and inflammation: A triangle of interest. Prog Neuropsychopharmacol Biol Psychiatry 2023; 122:110697. [PMID: 36521587 DOI: 10.1016/j.pnpbp.2022.110697] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Accepted: 12/09/2022] [Indexed: 12/14/2022]
Abstract
Social interaction difficulties are a hallmark of psychotic disorders, which in some cases can be definitely traced back to autoimmunological causes. Interestingly, systemic and intrathecal inflammation have been shown to significantly influence social processing by increasing sensitivity to threatening social stimuli, which bears some resemblance to psychosis. In this article, we review evidence for the involvement of systemic and intrathecal inflammatory processes in psychotic disorders and how this might help to explain some of the social impairments associated with this group of disorders. Vice versa, we also discuss evidence for the immunomodulatory function of social interactions and their potential role for therapeutic interventions in psychotic disorders.
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5
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Royse SK, Lopresti BJ, Mathis CA, Tollefson S, Narendran R. Beyond monoamines: II. Novel applications for PET imaging in psychiatric disorders. J Neurochem 2023; 164:401-443. [PMID: 35716057 DOI: 10.1111/jnc.15657] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Revised: 06/07/2022] [Accepted: 06/08/2022] [Indexed: 11/27/2022]
Abstract
Early applications of positron emission tomography (PET) in psychiatry sought to identify derangements of cerebral blood flow and metabolism. The need for more specific neurochemical imaging probes was soon evident, and these probes initially targeted the sites of action of neuroleptic (dopamine D2 receptors) and psychoactive (serotonin receptors) drugs. For nearly 30 years, the centrality of monoamine dysfunction in psychiatric disorders drove the development of an armamentarium of monoaminergic PET radiopharmaceuticals and imaging methodologies. However, continued investments in monoamine-enhancing drug development realized only modest gains in efficacy and tolerability. As patent protection for many widely prescribed and profitable psychiatric drugs lapsed, drug development pipelines shifted away from monoamines in search of novel targets with the promises of improved efficacy, or abandoned altogether. Over this period, PET radiopharmaceutical development activities closely parallelled drug development priorities, resulting in the development of new PET imaging agents for non-monoamine targets. In part two of this review, we survey clinical research studies using the novel targets and radiotracers described in part one across major psychiatric application areas such as substance use disorders, anxiety disorders, eating disorders, personality disorders, mood disorders, and schizophrenia. Important limitations of the studies described are discussed, as well as key methodologic issues, challenges to the field, and the status of clinical trials seeking to exploit these targets for novel therapeutics.
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Affiliation(s)
- Sarah K Royse
- Department of Radiology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Brian J Lopresti
- Department of Radiology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Chester A Mathis
- Department of Radiology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Savannah Tollefson
- Department of Radiology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Rajesh Narendran
- Department of Radiology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA.,Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
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6
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Altered expression of microglial markers of phagocytosis in schizophrenia. Schizophr Res 2023; 251:22-29. [PMID: 36527956 DOI: 10.1016/j.schres.2022.12.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Revised: 09/07/2022] [Accepted: 12/06/2022] [Indexed: 12/23/2022]
Abstract
BACKGROUND Cognitive disturbances in schizophrenia have been linked to a lower density of dendritic spines on pyramidal neurons in the prefrontal cortex (PFC). Complement component C4, which has previously been found at higher levels in schizophrenia, marks synapses for phagocytosis by microglia. Thus, elevated consumption of dendritic spines by microglia mediated through excessive complement activity may play a role in lower spine density in schizophrenia. However, it is unclear if microglia themselves have the molecular capacity for enhanced phagocytosis of spines in schizophrenia. METHODS Transcript levels for complement components and microglia-specific phagocytic markers were quantified using quantitative PCR in the PFC of 62 matched pairs of schizophrenia and unaffected comparison subjects and in antipsychotic-exposed monkeys. RESULTS Relative to comparison subjects, schizophrenia subjects had higher mRNA levels for C4 (+154 %); C1q (+69 %), which initiates the classical complement pathway that includes C4; and for microglia-specific markers that enable phagocytic activity including TAM receptor tyrosine kinases Axl (+27 %) and MerTK (+27 %) and lysosome-associated glycoprotein CD68 (+27 %) (all p ≤ .042). Transcript levels for microglial phagocytic markers were correlated with C4 mRNA levels in schizophrenia subjects (all r ≥ 0.31, p ≤ .015). We also found further evidence consistent with microglial activation in schizophrenia, including higher mRNA levels for THIK1 (TWIK-related halothane-inhibited potassium channel: +30 %) and lower mRNA levels for the purinergic receptor P2Y12 (-27 %) (all p ≤ .016). Transcript levels were unchanged in antipsychotic-exposed monkeys. CONCLUSIONS These results are consistent with the presence of increased complement activity and an elevated molecular capacity of microglia for phagocytosis in the same schizophrenia subjects.
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7
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Rodrigues-Neves AC, Ambrósio AF, Gomes CA. Microglia sequelae: brain signature of innate immunity in schizophrenia. Transl Psychiatry 2022; 12:493. [PMID: 36443303 PMCID: PMC9705537 DOI: 10.1038/s41398-022-02197-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Revised: 09/20/2022] [Accepted: 09/21/2022] [Indexed: 11/29/2022] Open
Abstract
Schizophrenia is a psychiatric disorder with significant impact on individuals and society. The current pharmacologic treatment, which principally alleviates psychosis, is focused on neurotransmitters modulation, relying on drugs with severe side effects and ineffectiveness in a significant percentage of cases. Therefore, and due to difficulties inherent to diagnosis and treatment, it is vital to reassess alternative cellular and molecular drug targets. Distinct risk factors - genetic, developmental, epigenetic, and environmental - have been associated with disease onset and progression, giving rise to the proposal of different pathophysiological mechanisms and putative pharmacological targets. Immunity is involved and, particularly microglia - innate immune cells of the central nervous system, critically involved in brain development - have captured attention as cellular players. Microglia undergo marked morphologic and functional alterations in the human disease, as well as in animal models of schizophrenia, as reported in several original papers. We cluster the main findings of clinical studies by groups of patients: (1) at ultra-high risk of psychosis, (2) with a first episode of psychosis or recent-onset schizophrenia, and (3) with chronic schizophrenia; in translational studies, we highlight the time window of appearance of particular microglia alterations in the most well studied animal model in the field (maternal immune activation). The organization of clinical and translational findings based on schizophrenia-associated microglia changes in different phases of the disease course may help defining a temporal pattern of microglia changes and may drive the design of novel therapeutic strategies.
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Affiliation(s)
- A. Catarina Rodrigues-Neves
- grid.8051.c0000 0000 9511 4342Univ Coimbra, Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, Coimbra, Portugal ,grid.8051.c0000 0000 9511 4342Univ Coimbra, Center for Innovative Biomedicine and Biotechnology (CIBB), Coimbra, Portugal ,grid.8051.c0000 0000 9511 4342Clinical Academic Center of Coimbra (CACC), Coimbra, Portugal ,grid.8051.c0000 0000 9511 4342Univ Coimbra, Faculty of Pharmacy, Coimbra, Portugal
| | - António. F. Ambrósio
- grid.8051.c0000 0000 9511 4342Univ Coimbra, Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, Coimbra, Portugal ,grid.8051.c0000 0000 9511 4342Univ Coimbra, Center for Innovative Biomedicine and Biotechnology (CIBB), Coimbra, Portugal ,grid.8051.c0000 0000 9511 4342Clinical Academic Center of Coimbra (CACC), Coimbra, Portugal
| | - Catarina A. Gomes
- grid.8051.c0000 0000 9511 4342Univ Coimbra, Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, Coimbra, Portugal ,grid.8051.c0000 0000 9511 4342Univ Coimbra, Center for Innovative Biomedicine and Biotechnology (CIBB), Coimbra, Portugal ,grid.8051.c0000 0000 9511 4342Clinical Academic Center of Coimbra (CACC), Coimbra, Portugal ,grid.8051.c0000 0000 9511 4342Univ Coimbra, Faculty of Pharmacy, Coimbra, Portugal
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8
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Rantala MJ, Luoto S, Borráz-León JI, Krams I. Schizophrenia: the new etiological synthesis. Neurosci Biobehav Rev 2022; 142:104894. [PMID: 36181926 DOI: 10.1016/j.neubiorev.2022.104894] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Revised: 08/25/2022] [Accepted: 09/25/2022] [Indexed: 10/31/2022]
Abstract
Schizophrenia has been an evolutionary paradox: it has high heritability, but it is associated with decreased reproductive success. The causal genetic variants underlying schizophrenia are thought to be under weak negative selection. To unravel this paradox, many evolutionary explanations have been suggested for schizophrenia. We critically discuss the constellation of evolutionary hypotheses for schizophrenia, highlighting the lack of empirical support for most existing evolutionary hypotheses-with the exception of the relatively well supported evolutionary mismatch hypothesis. It posits that evolutionarily novel features of contemporary environments, such as chronic stress, low-grade systemic inflammation, and gut dysbiosis, increase susceptibility to schizophrenia. Environmental factors such as microbial infections (e.g., Toxoplasma gondii) can better predict the onset of schizophrenia than polygenic risk scores. However, researchers have not been able to explain why only a small minority of infected people develop schizophrenia. The new etiological synthesis of schizophrenia indicates that an interaction between host genotype, microbe infection, and chronic stress causes schizophrenia, with neuroinflammation and gut dysbiosis mediating this etiological pathway. Instead of just alleviating symptoms with drugs, the parasite x genotype x stress model emphasizes that schizophrenia treatment should focus on detecting and treating possible underlying microbial infection(s), neuroinflammation, gut dysbiosis, and chronic stress.
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Affiliation(s)
- Markus J Rantala
- Department of Biology, University of Turku, FIN-20014 Turku, Finland.
| | - Severi Luoto
- School of Population Health, University of Auckland, 1023 Auckland, New Zealand
| | | | - Indrikis Krams
- Institute of Ecology and Earth Sciences, University of Tartu, 51014 Tartu, Estonia; Department of Zoology and Animal Ecology, Faculty of Biology, University of Latvia, 1004, Rīga, Latvia
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9
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Structural and Functional Deviations of the Hippocampus in Schizophrenia and Schizophrenia Animal Models. Int J Mol Sci 2022; 23:ijms23105482. [PMID: 35628292 PMCID: PMC9143100 DOI: 10.3390/ijms23105482] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Revised: 05/09/2022] [Accepted: 05/11/2022] [Indexed: 01/04/2023] Open
Abstract
Schizophrenia is a grave neuropsychiatric disease which frequently onsets between the end of adolescence and the beginning of adulthood. It is characterized by a variety of neuropsychiatric abnormalities which are categorized into positive, negative and cognitive symptoms. Most therapeutical strategies address the positive symptoms by antagonizing D2-dopamine-receptors (DR). However, negative and cognitive symptoms persist and highly impair the life quality of patients due to their disabling effects. Interestingly, hippocampal deviations are a hallmark of schizophrenia and can be observed in early as well as advanced phases of the disease progression. These alterations are commonly accompanied by a rise in neuronal activity. Therefore, hippocampal formation plays an important role in the manifestation of schizophrenia. Furthermore, studies with animal models revealed a link between environmental risk factors and morphological as well as electrophysiological abnormalities in the hippocampus. Here, we review recent findings on structural and functional hippocampal abnormalities in schizophrenic patients and in schizophrenia animal models, and we give an overview on current experimental approaches that especially target the hippocampus. A better understanding of hippocampal aberrations in schizophrenia might clarify their impact on the manifestation and on the outcome of this severe disease.
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10
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Monji A, Mizoguchi Y. Neuroinflammation in Late-Onset Schizophrenia: Viewing from the Standpoint of the Microglia Hypothesis. Neuropsychobiology 2022; 81:98-103. [PMID: 34515181 DOI: 10.1159/000517861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Accepted: 06/14/2021] [Indexed: 11/19/2022]
Abstract
Schizophrenia develops mainly in adolescence, but late-onset schizophrenia (LOS) is not uncommon. According to the international consensus, schizophrenia which develops over 40 years old is called LOS and psychosis which develops over 60 years old is called very late-onset schizophrenia-like psychosis (VLOS). Compared to early-onset schizophrenia (EOS) that develops before the age of 40 years, LOS and VLOS are reported to be more common in women, and there are clinically clear differences such as less involvement of genetic factors than EOS. This review outlines the abnormalities of the neuroimmune system in the pathophysiology of LOS, especially focusing on the role of microglia.
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Affiliation(s)
- Akira Monji
- Department of Psychiatry, Faculty of Medicine, Saga University, Saga, Japan
| | - Yoshito Mizoguchi
- Department of Psychiatry, Faculty of Medicine, Saga University, Saga, Japan
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11
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Chand GB, Jiang H, Miller JP, Rhodes CH, Tu Z, Wong DF. Differential Sphingosine-1-Phosphate Receptor-1 Protein Expression in the Dorsolateral Prefrontal Cortex Between Schizophrenia Type 1 and Type 2. Front Psychiatry 2022; 13:827981. [PMID: 35350429 PMCID: PMC8957823 DOI: 10.3389/fpsyt.2022.827981] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Accepted: 02/03/2022] [Indexed: 11/25/2022] Open
Abstract
Understanding the etiology and treatment approaches in schizophrenia is challenged in part by the heterogeneity of this disorder. One encouraging progress is the growing evidence that there are subtypes of schizophrenia. Recent in vitro findings of messenger ribonucleic acid (mRNA) gene expression on postmortem dorsolateral prefrontal cortex (DLPFC) showed that schizophrenia has two subtypes, those with a relatively normal DLPFC transcriptome (Type 1) and those with differentially expressed genes (Type 2). Sphingosine-1-phosphate receptor-1 (S1PR1) is one of the genes that was highly upregulated in Type 2 compared to Type 1 and controls. The impact of that finding is limited because it only can be confirmed through analysis of autopsy tissue, and the clinical characteristics such as symptoms severity or illness duration except for cause of death was not available from that Medical Examiner based autopsy study. However, S1PR1 has great potential because it is a target gene that can be accessed via positron emission tomography (PET) in vivo using specific radioligands (starting with [11C]CS1P1) successfully developed at our center in human brain imaging. As a preliminary study to validate this PET target in schizophrenia, S1PR1 protein expression was assessed by receptor autoradiography (ARG) using [3H]CS1P1 and immunohistochemistry (IHC) in the DLPFC from patients with schizophrenia classified as Type 1 or Type 2 based on their DLPFC transcriptomes and from controls. Our analyses demonstrate that ARG S1PR1 protein expression is significantly higher in Type 2 compared to Type 1 (p < 0.05) and controls (p < 0.05), which was consistent with previous mRNA S1PR1. These findings support the possibility that PET S1PR1 can be used as a future imaging biomarker to distinguish these subgroups of schizophrenic patients during life with obvious implications for both patient management and the design of clinical trials to validate novel pharmacologic therapies.
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Affiliation(s)
- Ganesh B. Chand
- Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO, United States
| | - Hao Jiang
- Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO, United States
| | - J. Philip Miller
- Division of Biostatistics, Washington University School of Medicine, St. Louis, MO, United States
| | | | - Zhude Tu
- Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO, United States
| | - Dean Foster Wong
- Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO, United States
- Department of Psychiatry, Neuroscience, and Neurology, Washington University School of Medicine, St. Louis, MO, United States
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12
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Glial Cell Abnormalities in Major Psychiatric Diseases: A Systematic Review of Postmortem Brain Studies. Mol Neurobiol 2022; 59:1665-1692. [PMID: 35013935 DOI: 10.1007/s12035-021-02672-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Accepted: 11/25/2021] [Indexed: 10/19/2022]
Abstract
There have been a large number of reports about glial cell dysfunction being related to major psychiatric diseases such as schizophrenia (SCZ), bipolar disorder (BD), and major depressive disorder (MDD). In this review, we provide an overview of postmortem studies analyzing the structural changes of glial cells in these three major psychiatric diseases, including the density, number and size of glial cells, and the expression of related markers. Up to May 1, 2021, 108 articles that met the inclusion criteria were identified by searching PubMed and Web of Science. Although most studies evaluating total glial cells did not show abnormalities in the brains of postmortem patients, astrocytes, microglial cells, and oligodendrocytes seem to have specific patterns of changes in each disease. For example, out of 20 studies that evaluated astrocyte markers in MDD, 11 studies found decreased astrocyte marker expression in MDD patients. Similarly, out of 25 studies evaluating oligodendrocyte markers in SCZ, 15 studies showed decreased expression of oligodendrocyte markers in different brain regions of SCZ patients. In addition, activated microglial cells were observed in patients with SCZ, BD, and MDD, but suicide may be a confounding factor for the observed effects. Although the data from the included studies were heterogeneous and this cannot be fully explained at present, it is likely that there are a variety of contributing factors, including the measured brain regions, methods of measurement, gender, age at time of death, and medications.
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13
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Aramideh JA, Vidal-Itriago A, Morsch M, Graeber MB. Cytokine Signalling at the Microglial Penta-Partite Synapse. Int J Mol Sci 2021; 22:ijms222413186. [PMID: 34947983 PMCID: PMC8708012 DOI: 10.3390/ijms222413186] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2021] [Revised: 12/01/2021] [Accepted: 12/02/2021] [Indexed: 12/28/2022] Open
Abstract
Microglial cell processes form part of a subset of synaptic contacts that have been dubbed microglial tetra-partite or quad-partite synapses. Since tetrapartite may also refer to the presence of extracellular matrix components, we propose the more precise term microglial penta-partite synapse for synapses that show a microglial cell process in close physical proximity to neuronal and astrocytic synaptic constituents. Microglial cells are now recognised as key players in central nervous system (CNS) synaptic changes. When synaptic plasticity involving microglial penta-partite synapses occurs, microglia may utilise their cytokine arsenal to facilitate the generation of new synapses, eliminate those that are not needed anymore, or modify the molecular and structural properties of the remaining synaptic contacts. In addition, microglia–synapse contacts may develop de novo under pathological conditions. Microglial penta-partite synapses have received comparatively little attention as unique sites in the CNS where microglial cells, cytokines and other factors they release have a direct influence on the connections between neurons and their function. It concerns our understanding of the penta-partite synapse where the confusion created by the term “neuroinflammation” is most counterproductive. The mere presence of activated microglia or the release of their cytokines may occur independent of inflammation, and penta-partite synapses are not usually active in a neuroimmunological sense. Clarification of these details is the main purpose of this review, specifically highlighting the relationship between microglia, synapses, and the cytokines that can be released by microglial cells in health and disease.
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Affiliation(s)
- Jason Abbas Aramideh
- Brain and Mind Centre, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW 2006, Australia;
| | - Andres Vidal-Itriago
- Faculty of Medicine, Health & Human Sciences, Macquarie Medical School, Macquarie University, Sydney, NSW 2109, Australia; (A.V.-I.); (M.M.)
| | - Marco Morsch
- Faculty of Medicine, Health & Human Sciences, Macquarie Medical School, Macquarie University, Sydney, NSW 2109, Australia; (A.V.-I.); (M.M.)
| | - Manuel B. Graeber
- Brain and Mind Centre, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW 2006, Australia;
- Correspondence:
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14
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Chauveau F, Becker G, Boutin H. Have (R)-[ 11C]PK11195 challengers fulfilled the promise? A scoping review of clinical TSPO PET studies. Eur J Nucl Med Mol Imaging 2021; 49:201-220. [PMID: 34387719 PMCID: PMC8712292 DOI: 10.1007/s00259-021-05425-w] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Accepted: 05/19/2021] [Indexed: 12/19/2022]
Abstract
PURPOSE The prototypical TSPO radiotracer (R)-[11C]PK11195 has been used in humans for more than thirty years to visualize neuroinflammation in several pathologies. Alternative radiotracers have been developed to improve signal-to-noise ratio and started to be tested clinically in 2008. Here we examined the scientific value of these "(R)-[11C]PK11195 challengers" in clinical research to determine if they could supersede (R)-[11C]PK11195. METHODS A systematic MEDLINE (PubMed) search was performed (up to end of year 2020) to extract publications reporting TSPO PET in patients with identified pathologies, excluding studies in healthy subjects and methodological studies. RESULTS Of the 288 publications selected, 152 used 13 challengers, and 142 used (R)-[11C]PK11195. Over the last 20 years, the number of (R)-[11C]PK11195 studies remained stable (6 ± 3 per year), but was surpassed by the total number of challenger studies for the last 6 years. In total, 3914 patients underwent a TSPO PET scan, and 47% (1851 patients) received (R)-[11C]PK11195. The 2 main challengers were [11C]PBR28 (24%-938 patients) and [18F]FEPPA (11%-429 patients). Only one-in-ten patients (11%-447) underwent 2 TSPO scans, among whom 40 (1%) were scanned with 2 different TSPO radiotracers. CONCLUSIONS Generally, challengers confirmed disease-specific initial (R)-[11C]PK11195 findings. However, while their better signal-to-noise ratio seems particularly useful in diseases with moderate and widespread neuroinflammation, most challengers present an allelic-dependent (Ala147Thr polymorphism) TSPO binding and genetic stratification is hindering their clinical implementation. As new challengers, insensitive to TSPO human polymorphism, are about to enter clinical evaluation, we propose this systematic review to be regularly updated (living review).
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Affiliation(s)
- Fabien Chauveau
- University of Lyon, Lyon Neuroscience Research Center (CRNL), CNRS UMR5292, INSERM U1028, University Lyon 1, Lyon, France.
| | - Guillaume Becker
- GIGA - CRC In Vivo Imaging, University Liege, Liege, Belgium
- University of Lyon, CarMeN Laboratory, INSERM U1060, University Lyon 1, Hospices Civils Lyon, Lyon, France
| | - Hervé Boutin
- Faculty of Biology Medicine and Health, Wolfson Molecular Imaging Centre, University of Manchester, Manchester, UK.
- Wolfson Molecular Imaging Centre, University of Manchester, Manchester, UK.
- Geoffrey Jefferson Brain Research Centre, Manchester Academic Health Science Centre, Northern Care Alliance & University of Manchester, Manchester, UK.
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15
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De Picker LJ, Haarman BCM. Applicability, potential and limitations of TSPO PET imaging as a clinical immunopsychiatry biomarker. Eur J Nucl Med Mol Imaging 2021; 49:164-173. [PMID: 33735406 DOI: 10.1007/s00259-021-05308-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Accepted: 03/08/2021] [Indexed: 02/08/2023]
Abstract
PURPOSE TSPO PET imaging may hold promise as a single-step diagnostic work-up for clinical immunopsychiatry. This review paper on the clinical applicability of TSPO PET for primary psychiatric disorders discusses if and why TSPO PET imaging might become the first clinical immunopsychiatry biomarker and the investment prerequisites and scientific advancements needed to accommodate this transition from bench to bedside. METHODS We conducted a systematic search of the literature to identify clinical studies of TSPO PET imaging in patients with primary psychiatric disorders. We included both original case-control studies as well as longitudinal cohort studies of patients with a primary psychiatric diagnosis. RESULTS Thirty-one original studies met our inclusion criteria. In the field of immunopsychiatry, TSPO PET has until now mostly been studied in schizophrenia and related psychotic disorders, and to a lesser extent in mood disorders and neurodevelopmental disorders. Quantitative TSPO PET appears most promising as a predictive biomarker for the transdiagnostic identification of subgroups or disease stages that could benefit from immunological treatments, or as a prognostic biomarker forecasting patients' illness course. Current scanning protocols are still too unreliable, impractical and invasive for clinical use in symptomatic psychiatric patients. CONCLUSION TSPO PET imaging in its present form does not yet offer a sufficiently attractive cost-benefit ratio to become a clinical immunopsychiatry biomarker. Its translation to psychiatric clinical practice will depend on the prioritising of longitudinal research and the establishment of a uniform protocol rendering clinically meaningful TSPO uptake quantification at the shortest possible scan duration without arterial cannulation.
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Affiliation(s)
- Livia J De Picker
- University Psychiatric Hospital Campus Duffel, Stationsstraat 22C, 2570, Duffel, Belgium.
- Collaborative Antwerp Psychiatric Research Institute, University of Antwerp, Wilrijkstraat 1, 2650, Edegem, Belgium.
| | - Benno C M Haarman
- Department of Psychiatry, University Medical Center Groningen, University of Groningen, Hanzeplein 1, 9700RA, Groningen, The Netherlands
- Rob Giel Research Center (RGOc), University Medical Center Groningen, University of Groningen, Hanzeplein 1, 9700RA, Groningen, The Netherlands
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16
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De Picker LJ, Victoriano GM, Richards R, Gorvett AJ, Lyons S, Buckland GR, Tofani T, Norman JL, Chatelet DS, Nicoll JAR, Boche D. Immune environment of the brain in schizophrenia and during the psychotic episode: A human post-mortem study. Brain Behav Immun 2021; 97:319-327. [PMID: 34339805 PMCID: PMC8475749 DOI: 10.1016/j.bbi.2021.07.017] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 07/22/2021] [Accepted: 07/24/2021] [Indexed: 02/05/2023] Open
Abstract
A causal relationship between immune dysregulation and schizophrenia has been supported by genome-wide association studies and epidemiological evidence. It remains unclear to what extent the brain immune environment is implicated in this hypothesis. We investigated the immunophenotype of microglia and the presence of perivascular macrophages and T lymphocytes in post-mortem brain tissue. Dorsal prefrontal cortex of 40 controls (22F:18M) and 37 (10F:27M) schizophrenia cases, of whom 16 had active psychotic symptoms at the time of death, was immunostained for seven markers of microglia (CD16, CD32a, CD64, CD68, HLA-DR, Iba1 and P2RY12), two markers for perivascular macrophages (CD163 and CD206) and T-lymphocytes (CD3). Automated quantification was blinded to the case designation and performed separately on the grey and white matter. 3D reconstruction of Iba1-positive microglia was performed in selected cases. An increased cortical expression of microglial Fcγ receptors (CD64 F = 7.92, p = 0.007; CD64/HLA-DR ratio F = 5.02, p = 0.029) highlights the importance of communication between the central and peripheral immune systems in schizophrenia. Patients in whom psychotic symptoms were present at death demonstrated an age-dependent increase of Iba1 and increased CD64/HLA-DR ratios relative to patients without psychotic symptoms. Microglia in schizophrenia demonstrated a primed/reactive morphology. A potential role for T-lymphocytes was observed, but we did not confirm the presence of recruited macrophages in the brains of schizophrenia patients. Taking in account the limitations of a post-mortem study, our findings support the hypothesis of an alteration of the brain immune environment in schizophrenia, with symptomatic state- and age-dependent effects.
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Affiliation(s)
- Livia J De Picker
- Collaborative Antwerp Psychiatric Research Institute, University of Antwerp, Antwerp, Belgium; University Psychiatric Department Campus Duffel, Duffel, Belgium
| | - Gerardo Mendez Victoriano
- Clinical Neurosciences, Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK
| | - Rhys Richards
- Clinical Neurosciences, Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK
| | - Alexander J Gorvett
- Clinical Neurosciences, Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK
| | - Simeon Lyons
- Clinical Neurosciences, Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK
| | - George R Buckland
- Clinical Neurosciences, Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK
| | - Tommaso Tofani
- Psychiatry Unit, Health Science Department, University of Florence, Florence, Italy
| | - Jeanette L Norman
- Histochemistry Research Unit, Clinical and Experimental Sciences, Faculty of Medicine University of Southampton, Southampton, UK
| | - David S Chatelet
- Biomedical Imaging Unit, Southampton General Hospital, University of Southampton, Southampton, UK
| | - James A R Nicoll
- Clinical Neurosciences, Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK; Department of Cellular Pathology, University Hospital Southampton NHS Foundation Trust, Southampton, UK
| | - Delphine Boche
- Clinical Neurosciences, Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK.
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17
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Snijders GJLJ, Sneeboer MAM, Fernández-Andreu A, Udine E, Boks MP, Ormel PR, van Berlekom AB, van Mierlo HC, Bӧttcher C, Priller J, Raj T, Hol EM, Kahn RS, de Witte LD. Distinct non-inflammatory signature of microglia in post-mortem brain tissue of patients with major depressive disorder. Mol Psychiatry 2021; 26:3336-3349. [PMID: 33028963 DOI: 10.1038/s41380-020-00896-z] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 08/22/2020] [Accepted: 09/17/2020] [Indexed: 02/06/2023]
Abstract
Findings from epidemiological studies, biomarker measurements and animal experiments suggest a role for aberrant immune processes in the pathogenesis of major depressive disorder (MDD). Microglia, the resident immune cells of the brain, are likely to play a key role in these processes. Previous post-mortem studies reported conflicting findings regarding microglial activation and an in-depth profiling of those cells in MDD is lacking. The aim of this study was therefore to characterize the phenotype and function of microglia in MDD. We isolated microglia from post-mortem brain tissue of patients with MDD (n = 13-19) and control donors (n = 12-25). Using flow cytometry and quantitative Polymerase Chain Reaction (qPCR), we measured protein and mRNA levels of a panel of microglial markers across four different brain regions (medial frontal gyrus, superior temporal gyrus, thalamus, and subventricular zone). In MDD cases, we found a significant upregulation of CX3CR1 and TMEM119 mRNA expression and a downregulation of CD163 mRNA expression and CD14 protein expression across the four brain regions. Expression levels of microglial activation markers, such as HLA-DRA, IL6, and IL1β, as well as the inflammatory responses to lipopolysaccharide and dexamethasone were unchanged. Our findings suggest that microglia enhance homeostatic functions in MDD but are not immune activated.
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Affiliation(s)
- Gijsje J L J Snijders
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, USA. .,Department of Psychiatry, University Medical Center Utrecht Brain Center, Utrecht University, 3584, CG, Utrecht, The Netherlands.
| | - Marjolein A M Sneeboer
- Department of Psychiatry, University Medical Center Utrecht Brain Center, Utrecht University, 3584, CG, Utrecht, The Netherlands.,Department of Translational Neuroscience, University Medical Center Utrecht Brain Center, Utrecht University, 3584, CG, Utrecht, The Netherlands
| | - Alba Fernández-Andreu
- Department of Translational Neuroscience, University Medical Center Utrecht Brain Center, Utrecht University, 3584, CG, Utrecht, The Netherlands
| | - Evan Udine
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | | | - Marco P Boks
- Department of Psychiatry, University Medical Center Utrecht Brain Center, Utrecht University, 3584, CG, Utrecht, The Netherlands
| | - Paul R Ormel
- Department of Psychiatry, University Medical Center Utrecht Brain Center, Utrecht University, 3584, CG, Utrecht, The Netherlands.,Department of Translational Neuroscience, University Medical Center Utrecht Brain Center, Utrecht University, 3584, CG, Utrecht, The Netherlands
| | - Amber Berdenis van Berlekom
- Department of Psychiatry, University Medical Center Utrecht Brain Center, Utrecht University, 3584, CG, Utrecht, The Netherlands.,Department of Translational Neuroscience, University Medical Center Utrecht Brain Center, Utrecht University, 3584, CG, Utrecht, The Netherlands
| | - Hans C van Mierlo
- Department of Psychiatry, St. Antonius Hospital, Nieuwegein, Koekoekslaan 1, 3430, EM, Nieuwegein, The Netherlands
| | - Chotima Bӧttcher
- Department of Neuropsychiatry and Laboratory of Molecular Psychiatry, Charité-Universitätsmedizin Berlin, 10117, Berlin, Germany
| | - Josef Priller
- Department of Neuropsychiatry and Laboratory of Molecular Psychiatry, Charité-Universitätsmedizin Berlin, 10117, Berlin, Germany.,DZNE and BIH, 10117, Berlin, Germany.,University of Edinburgh and UK DRI, Edinburgh, EH16 4SB, UK
| | - Towfique Raj
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Elly M Hol
- Department of Translational Neuroscience, University Medical Center Utrecht Brain Center, Utrecht University, 3584, CG, Utrecht, The Netherlands.,Neuroimmunology, Netherlands Institute for Neuroscience, an institute of the royal academy of arts and sciences, 1105, BA, Amsterdam, The Netherlands
| | - René S Kahn
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, USA.,Department of Psychiatry, University Medical Center Utrecht Brain Center, Utrecht University, 3584, CG, Utrecht, The Netherlands.,Mental Illness Research Education Clinical, Centers of Excellence, VA, Mental Health, Veterans, Bronx, NY, USA
| | - Lot D de Witte
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, USA.,Department of Psychiatry, University Medical Center Utrecht Brain Center, Utrecht University, 3584, CG, Utrecht, The Netherlands.,Mental Illness Research Education Clinical, Centers of Excellence, VA, Mental Health, Veterans, Bronx, NY, USA
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18
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Izuo N, Nitta A. New Insights Regarding Diagnosis and Medication for Schizophrenia Based on Neuronal Synapse-Microglia Interaction. J Pers Med 2021; 11:jpm11050371. [PMID: 34063598 PMCID: PMC8147599 DOI: 10.3390/jpm11050371] [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: 03/13/2021] [Revised: 04/27/2021] [Accepted: 04/28/2021] [Indexed: 01/01/2023] Open
Abstract
Schizophrenia is a common psychiatric disorder that usually develops during adolescence and young adulthood. Since genetic and environmental factors are involved in the disease, the molecular status of the pathology of schizophrenia differs across patients. Recent genetic studies have focused on the association between schizophrenia and the immune system, especially microglia–synapse interactions. Microglia physiologically eliminate unnecessary synapses during the developmental period. The overactivation of synaptic pruning by microglia is involved in the pathology of brain disease. This paper focuses on the synaptic pruning function and its molecular machinery and introduces the hypothesis that excessive synaptic pruning plays a role in the development of schizophrenia. Finally, we suggest a strategy for diagnosis and medication based on modulation of the interaction between microglia and synapses. This review provides updated information on the involvement of the immune system in schizophrenia and proposes novel insights regarding diagnostic and therapeutic strategies for this disease.
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Affiliation(s)
| | - Atsumi Nitta
- Correspondence: ; Tel.: +81-76-415-8822 (ext. 8823); Fax: +81-76-415-8826
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19
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Snijders GJLJ, van Zuiden W, Sneeboer MAM, Berdenis van Berlekom A, van der Geest AT, Schnieder T, MacIntyre DJ, Hol EM, Kahn RS, de Witte LD. A loss of mature microglial markers without immune activation in schizophrenia. Glia 2021; 69:1251-1267. [PMID: 33410555 PMCID: PMC7986895 DOI: 10.1002/glia.23962] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Revised: 12/04/2020] [Accepted: 12/23/2020] [Indexed: 02/06/2023]
Abstract
Microglia, the immune cells of the brain, are important for neurodevelopment and have been hypothesized to play a role in the pathogenesis of schizophrenia (SCZ). Although previous postmortem studies pointed toward presence of microglial activation, this view has been challenged by more recent hypothesis-driven and hypothesis-free analyses. The aim of the present study is to further understand the observed microglial changes in SCZ. We first performed a detailed meta-analysis on studies that analyzed microglial cell density, microglial morphology, and expression of microglial-specific markers. We then further explored findings from the temporal cortex by performing immunostainings and qPCRs on an additional dataset. A random effect meta-analysis showed that the density of microglial cells was unaltered in SCZ (ES: 0.144 95% CI: 0.102 to 0.390, p = .250), and clear changes in microglial morphology were also absent. The expression of several microglial specific genes, such as CX3CR1, CSF1R, IRF8, OLR1, and TMEM119 was decreased in SCZ (ES: -0.417 95% CI: -0.417 to -0.546, p < .0001), consistent with genome-wide transcriptome meta-analysis results. These results indicate a change in microglial phenotype rather than density, which was validated with the use of TMEM119/Iba1 immunostainings on temporal cortex of a separate cohort. Changes in microglial gene expression were overlapping between SCZ and other psychiatric disorders, but largely opposite from changes reported in Alzheimer's disease. This distinct microglial phenotype provides a crucial molecular hallmark for future research into the role of microglia in SCZ and other psychiatric disorders.
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Affiliation(s)
- Gijsje J. L. J. Snijders
- Department of Psychiatry, University Medical Center Utrecht Brain Center, Utrecht University, Brain Center Rudolf MagnusUniversity Medical Center Utrecht, Utrecht University (BCRM‐UMCU‐UU)UtrechtThe Netherlands
- Department of PsychiatryIcahn School of MedicineNew YorkNew YorkUSA
| | | | | | - Amber Berdenis van Berlekom
- Department of Psychiatry, University Medical Center Utrecht Brain Center, Utrecht University, Brain Center Rudolf MagnusUniversity Medical Center Utrecht, Utrecht University (BCRM‐UMCU‐UU)UtrechtThe Netherlands
- Department of Translational Neuroscience (BCRM‐UMCU‐UU)UtrechtThe Netherlands
| | | | | | - Donald J. MacIntyre
- Division of Psychiatry, Centre for Clinical Brain SciencesUniversity of EdinburghEdinburghUK
| | - Elly M. Hol
- Department of Translational Neuroscience (BCRM‐UMCU‐UU)UtrechtThe Netherlands
- Neuroimmunology, Netherlands Institute for Neuroscience, An Institute of the Royal Academy of Arts and SciencesAmsterdamThe Netherlands
| | - René S. Kahn
- Department of PsychiatryIcahn School of MedicineNew YorkNew YorkUSA
- Mental Illness Research, Education and Clinical Center (MIRECC), James J Peters VA Medical CenterBronxNew YorkUSA
| | - Lot D. de Witte
- Department of Psychiatry, University Medical Center Utrecht Brain Center, Utrecht University, Brain Center Rudolf MagnusUniversity Medical Center Utrecht, Utrecht University (BCRM‐UMCU‐UU)UtrechtThe Netherlands
- Department of PsychiatryIcahn School of MedicineNew YorkNew YorkUSA
- Mental Illness Research, Education and Clinical Center (MIRECC), James J Peters VA Medical CenterBronxNew YorkUSA
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20
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Corsi-Zuelli F, Deakin B. Impaired regulatory T cell control of astroglial overdrive and microglial pruning in schizophrenia. Neurosci Biobehav Rev 2021; 125:637-653. [PMID: 33713699 DOI: 10.1016/j.neubiorev.2021.03.004] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Revised: 02/16/2021] [Accepted: 03/06/2021] [Indexed: 02/07/2023]
Abstract
It is widely held that schizophrenia involves an active process of peripheral inflammation that induces or reflects brain inflammation with activation of microglia, the brain's resident immune cells. However, recent in vivo radioligand binding studies and large-scale transcriptomics in post-mortem brain report reduced markers of microglial inflammation. The findings suggest a contrary hypothesis; that microglia are diverted into their non-inflammatory synaptic remodelling phenotype that interferes with neurodevelopment and perhaps contributes to the relapsing nature of schizophrenia. Recent discoveries on the regulatory interactions between micro- and astroglial cells and immune regulatory T cells (Tregs) cohere with clinical omics data to suggest that: i) disinhibited astrocytes mediate the shift in microglial phenotype via the production of transforming growth factor-beta, which also contributes to the disturbances of dopamine and GABA function in schizophrenia, and ii) systemically impaired functioning of Treg cells contributes to the dysregulation of glial function, the low-grade peripheral inflammation, and the hitherto unexplained predisposition to auto-immunity and reduced life-expectancy in schizophrenia, including greater COVID-19 mortality.
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Affiliation(s)
- Fabiana Corsi-Zuelli
- Department of Neuroscience and Behaviour, Division of Psychiatry, Ribeirão Preto Medical School, University of São Paulo, 14048-900, Ribeirão Preto, São Paulo, Brazil
| | - Bill Deakin
- Division of Neuroscience and Experimental Psychology, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre, Manchester, M13 9PT, UK.
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21
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Plavén-Sigray P, Matheson GJ, Coughlin JM, Hafizi S, Laurikainen H, Ottoy J, De Picker L, Rusjan P, Hietala J, Howes OD, Mizrahi R, Morrens M, Pomper MG, Cervenka S. Meta-analysis of the Glial Marker TSPO in Psychosis Revisited: Reconciling Inconclusive Findings of Patient-Control Differences. Biol Psychiatry 2021; 89:e5-e8. [PMID: 32682565 PMCID: PMC7899168 DOI: 10.1016/j.biopsych.2020.05.028] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Revised: 05/12/2020] [Accepted: 05/17/2020] [Indexed: 12/20/2022]
Affiliation(s)
- Pontus Plavén-Sigray
- Centre for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet and Stockholm Health Care Services, Region Stockholm, Stockholm, Sweden,Neurobiology Research Unit, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | - Granville J. Matheson
- Centre for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet and Stockholm Health Care Services, Region Stockholm, Stockholm, Sweden
| | - Jennifer M. Coughlin
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins Medical Institutions, Baltimore, Maryland,Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Sina Hafizi
- Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada
| | - Heikki Laurikainen
- Department of Psychiatry, University of Turku and Neuropsychiatric Imaging Group, Turku PET Centre, Turku University Hospital, Turku, Finland
| | - Julie Ottoy
- Molecular Imaging Center Antwerp, University of Antwerp, Antwerp, Belgium
| | - Livia De Picker
- Collaborative Antwerp Psychiatric Research Institute (CAPRI), University of Antwerp, Antwerp, Belgium
| | - Pablo Rusjan
- Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada
| | - Jarmo Hietala
- Department of Psychiatry, University of Turku and Neuropsychiatric Imaging Group, Turku PET Centre, Turku University Hospital, Turku, Finland
| | - Oliver D. Howes
- Institute of Psychiatry, Psychology and Neuroscience, King’s College London,MRC London Institute of Medical Sciences, Faculty of Medicine, Imperial College London, London, United Kingdom,Hammersmith Hospital; and Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Romina Mizrahi
- Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada
| | - Manuel Morrens
- Collaborative Antwerp Psychiatric Research Institute (CAPRI), University of Antwerp, Antwerp, Belgium
| | - Martin G. Pomper
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins Medical Institutions, Baltimore, Maryland,Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Simon Cervenka
- Centre for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet and Stockholm Health Care Services, Region Stockholm, Stockholm, Sweden.
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22
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Neuronal activity increases translocator protein (TSPO) levels. Mol Psychiatry 2021; 26:2025-2037. [PMID: 32398717 PMCID: PMC8440208 DOI: 10.1038/s41380-020-0745-1] [Citation(s) in RCA: 69] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Revised: 04/03/2020] [Accepted: 04/20/2020] [Indexed: 12/19/2022]
Abstract
The mitochondrial protein, translocator protein (TSPO), is a widely used biomarker of neuroinflammation, but its non-selective cellular expression pattern implies roles beyond inflammatory processes. In the present study, we investigated whether neuronal activity modifies TSPO levels in the adult central nervous system. First, we used single-cell RNA sequencing to generate a cellular landscape of basal TSPO gene expression in the hippocampus of adult (12 weeks old) C57BL6/N mice, followed by confocal laser scanning microscopy to verify TSPO protein in neuronal and non-neuronal cell populations. We then quantified TSPO mRNA and protein levels after stimulating neuronal activity with distinct stimuli, including designer receptors exclusively activated by designer drugs (DREADDs), exposure to a novel environment and acute treatment with the psychostimulant drug, amphetamine. Single-cell RNA sequencing demonstrated a non-selective and multi-cellular gene expression pattern of TSPO at basal conditions in the adult mouse hippocampus. Confocal laser scanning microscopy confirmed that TSPO protein is present in neuronal and non-neuronal (astrocytes, microglia, vascular endothelial cells) cells of cortical (medial prefrontal cortex) and subcortical (hippocampus) brain regions. Stimulating neuronal activity through chemogenetic (DREADDs), physiological (novel environment exposure) or psychopharmacological (amphetamine treatment) approaches led to consistent increases in TSPO gene and protein levels in neurons, but not in microglia or astrocytes. Taken together, our findings show that neuronal activity has the potential to modify TSPO levels in the adult central nervous system. These findings challenge the general assumption that altered TSPO expression or binding unequivocally mirrors ongoing neuroinflammation and emphasize the need to consider non-inflammatory interpretations in some physiological or pathological contexts.
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Iliopoulou SM, Tsartsalis S, Kaiser S, Millet P, Tournier BB. Dopamine and Neuroinflammation in Schizophrenia - Interpreting the Findings from Translocator Protein (18kDa) PET Imaging. Neuropsychiatr Dis Treat 2021; 17:3345-3357. [PMID: 34819729 PMCID: PMC8608287 DOI: 10.2147/ndt.s334027] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Accepted: 10/09/2021] [Indexed: 12/22/2022] Open
Abstract
Schizophrenia is a complex disease whose pathophysiology is not yet fully understood. In addition to the long prevailing dopaminergic hypothesis, the evidence suggests that neuroinflammation plays a role in the pathophysiology of the disease. Recent studies using positron emission tomography (PET) that target a 18kDa translocator protein (TSPO) in activated microglial cells in an attempt to measure neuroinflammation in patients have shown a decrease or a lack of an increase in TSPO binding. Many biological and methodological considerations have been formulated to explain these findings. Although dopamine has been described as an immunomodulatory molecule, its potential role in neuroinflammation has not been explored in the aforementioned studies. In this review, we discuss the interactions between dopamine and neuroinflammation in psychotic states. Dopamine may inhibit neuroinflammation in activated microglia. Proinflammatory molecules released from microglia may decrease dopaminergic transmission. This could potentially explain why the levels of neuroinflammation in the brain of patients with schizophrenia seem to be unchanged or decreased compared to those in healthy subjects. However, most data are indirect and are derived from animal studies or from studies performed outside the field of schizophrenia. Further studies are needed to combine TSPO and dopamine imaging to study the association between microglial activation and dopamine system function.
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Affiliation(s)
- Sotiria Maria Iliopoulou
- Adult Psychiatry Division, Department of Psychiatry, Geneva University Hospitals (HUG), Geneva, 1225, Switzerland
| | | | - Stefan Kaiser
- Adult Psychiatry Division, Department of Psychiatry, Geneva University Hospitals (HUG), Geneva, 1225, Switzerland.,Faculty of Medicine, University of Geneva, Geneva, 1204, Switzerland
| | - Philippe Millet
- Adult Psychiatry Division, Department of Psychiatry, Geneva University Hospitals (HUG), Geneva, 1225, Switzerland.,Faculty of Medicine, University of Geneva, Geneva, 1204, Switzerland
| | - Benjamin B Tournier
- Adult Psychiatry Division, Department of Psychiatry, Geneva University Hospitals (HUG), Geneva, 1225, Switzerland.,Faculty of Medicine, University of Geneva, Geneva, 1204, Switzerland
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Neuroinflammation as measured by positron emission tomography in patients with recent onset and established schizophrenia: implications for immune pathogenesis. Mol Psychiatry 2021; 26:5398-5406. [PMID: 32606376 PMCID: PMC8589678 DOI: 10.1038/s41380-020-0829-y] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Revised: 06/09/2020] [Accepted: 06/18/2020] [Indexed: 12/30/2022]
Abstract
Positron emission tomography (PET) imaging of the 18 kDa translocator protein (TSPO), which is upregulated in activated microglia, is a method for investigating whether immune activation is evident in the brain of adults with schizophrenia. This study aimed to measure TSPO availability in the largest patient group to date, and to compare it between patients with recent onset (ROS) and established (ES) schizophrenia. In total, 20 ROS patients (14 male), 21 ES (13 male), and 21 healthy controls completed the study. Patients were predominantly antipsychotic-medicated. Participants underwent a PET scan using the TSPO-specific radioligand [11C](R)-PK11195. The primary outcome was binding potential (BPND) in the anterior cingulate cortex (ACC). Secondary outcomes were BPND in six other regions. Correlations were investigated between TSPO availability and symptom severity. Data showed that mean BPND was higher in older (ES and controls) compared with younger (ROS and controls) individuals, but did not significantly differ between ROS or ES and their respective age-matched controls (ACC; ANOVA main effect of diagnosis: F1,58 = 0.407, p = 0.526). Compared with controls, BPND was lower in antipsychotic-free (n = 6), but not in medicated, ROS patients. BPND in the ES group was negatively correlated with positive symptoms, and positively correlated with negative symptom score. Our data suggest ageing is associated with higher TSPO but a diagnosis of schizophrenia is not. Rather, subnormal TSPO levels in drug-free recent-onset patients may imply impaired microglial development and/or function, which is counteracted by antipsychotic treatment. The development of novel radioligands for specific immune-mechanisms is needed for further clarification.
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Dinesh AA, Islam J, Khan J, Turkheimer F, Vernon AC. Effects of Antipsychotic Drugs: Cross Talk Between the Nervous and Innate Immune System. CNS Drugs 2020; 34:1229-1251. [PMID: 32975758 DOI: 10.1007/s40263-020-00765-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 08/29/2020] [Indexed: 12/11/2022]
Abstract
Converging lines of evidence suggest that activation of microglia (innate immune cells in the central nervous system [CNS]) is present in a subset of patients with schizophrenia. The extent to which antipsychotic drug treatment contributes to or combats this effect remains unclear. To address this question, we reviewed the literature for evidence that antipsychotic exposure influences brain microglia as indexed by in vivo neuroimaging and post-mortem studies in patients with schizophrenia and experimental animal models. We found no clear evidence from clinical studies for an effect of antipsychotics on either translocator protein (TSPO) radioligand binding (an in vivo neuroimaging measure of putative gliosis) or markers of brain microglia in post-mortem studies. In experimental animals, where drug and illness effects may be differentiated, we also found no clear evidence for consistent effects of antipsychotic drugs on TSPO radioligand binding. By contrast, we found evidence that chronic antipsychotic exposure may influence central microglia density and morphology. However, these effects were dependent on the dose and duration of drug exposure and whether an immune stimulus was present or not. In the latter case, antipsychotics were generally reported to suppress expression of inflammatory cytokines and inducible inflammatory enzymes such as cyclooxygenase and microglia activation. No clear conclusions could be drawn with regard to any effect of antipsychotics on brain microglia from current clinical data. There is evidence to suggest that antipsychotic drugs influence brain microglia in experimental animals, including possible anti-inflammatory actions. However, we lack detailed information on how these drugs influence brain microglia function at the molecular level. The clinical relevance of the animal data with regard to beneficial treatment effects and detrimental side effects of antipsychotic drugs also remains unknown, and further studies are warranted.
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Affiliation(s)
- Ayushi Anna Dinesh
- School of Medicine, Faculty of Life Sciences and Medicine, King's College London, London, United Kingdom
| | - Juned Islam
- School of Medicine, Faculty of Life Sciences and Medicine, King's College London, London, United Kingdom
| | - Javad Khan
- School of Medicine, Faculty of Life Sciences and Medicine, King's College London, London, United Kingdom
| | - Federico Turkheimer
- Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King's College London, Centre for Neuroimaging Sciences, De Crespigny Park, London, SE5 8AF, United Kingdom
- MRC Centre for Neurodevelopmental Disorders, King's College London, London, SE1 1UL, United Kingdom
| | - Anthony C Vernon
- MRC Centre for Neurodevelopmental Disorders, King's College London, London, SE1 1UL, United Kingdom.
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, Maurice Wohl Clinical Neuroscience Institute, 5 Cutcombe Road, London, SE5 9RT, United Kingdom.
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Comer AL, Carrier M, Tremblay MÈ, Cruz-Martín A. The Inflamed Brain in Schizophrenia: The Convergence of Genetic and Environmental Risk Factors That Lead to Uncontrolled Neuroinflammation. Front Cell Neurosci 2020; 14:274. [PMID: 33061891 PMCID: PMC7518314 DOI: 10.3389/fncel.2020.00274] [Citation(s) in RCA: 100] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Accepted: 08/03/2020] [Indexed: 12/12/2022] Open
Abstract
Schizophrenia is a disorder with a heterogeneous etiology involving complex interplay between genetic and environmental risk factors. The immune system is now known to play vital roles in nervous system function and pathology through regulating neuronal and glial development, synaptic plasticity, and behavior. In this regard, the immune system is positioned as a common link between the seemingly diverse genetic and environmental risk factors for schizophrenia. Synthesizing information about how the immune-brain axis is affected by multiple factors and how these factors might interact in schizophrenia is necessary to better understand the pathogenesis of this disease. Such knowledge will aid in the development of more translatable animal models that may lead to effective therapeutic interventions. Here, we provide an overview of the genetic risk factors for schizophrenia that modulate immune function. We also explore environmental factors for schizophrenia including exposure to pollution, gut dysbiosis, maternal immune activation and early-life stress, and how the consequences of these risk factors are linked to microglial function and dysfunction. We also propose that morphological and signaling deficits of the blood-brain barrier, as observed in some individuals with schizophrenia, can act as a gateway between peripheral and central nervous system inflammation, thus affecting microglia in their essential functions. Finally, we describe the diverse roles that microglia play in response to neuroinflammation and their impact on brain development and homeostasis, as well as schizophrenia pathophysiology.
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Affiliation(s)
- Ashley L. Comer
- Graduate Program for Neuroscience, Boston University, Boston, MA, United States
- Department of Biology, Boston University, Boston, MA, United States
- Neurophotonics Center, Boston University, Boston, MA, United States
- Center for Systems Neuroscience, Boston University, Boston, MA, United States
| | - Micaël Carrier
- Axe Neurosciences, Centre de Recherche du CHU de Québec, Université Laval, Québec City, QC, Canada
| | - Marie-Ève Tremblay
- Axe Neurosciences, Centre de Recherche du CHU de Québec, Université Laval, Québec City, QC, Canada
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
- Department of Biochemistry and Molecular Biology, The University of British Columbia, Vancouver, BC, Canada
| | - Alberto Cruz-Martín
- Graduate Program for Neuroscience, Boston University, Boston, MA, United States
- Department of Biology, Boston University, Boston, MA, United States
- Neurophotonics Center, Boston University, Boston, MA, United States
- Center for Systems Neuroscience, Boston University, Boston, MA, United States
- Department of Pharmacology and Experimental Therapeutics, Boston University, Boston, MA, United States
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