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Brown TC, Crouse EC, Attaway CA, Oakes DK, Minton SW, Borghuis BG, McGee AW. Microglia are dispensable for experience-dependent refinement of mouse visual circuitry. Nat Neurosci 2024; 27:1462-1467. [PMID: 38977886 DOI: 10.1038/s41593-024-01706-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Accepted: 06/17/2024] [Indexed: 07/10/2024]
Abstract
To test the hypothesized crucial role of microglia in the developmental refinement of neural circuitry, we depleted microglia from mice of both sexes with PLX5622 and examined the experience-dependent maturation of visual circuitry and function. We assessed retinal function, receptive field tuning of visual cortex neurons, acuity and experience-dependent plasticity. None of these measurements detectibly differed in the absence of microglia, challenging the role of microglia in sculpting neural circuits.
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Affiliation(s)
- Thomas C Brown
- Department of Anatomical Sciences and Neurobiology, The University of Louisville School of Medicine, Louisville, KY, USA
| | - Emily C Crouse
- Department of Anatomical Sciences and Neurobiology, The University of Louisville School of Medicine, Louisville, KY, USA
| | - Cecilia A Attaway
- Department of Anatomical Sciences and Neurobiology, The University of Louisville School of Medicine, Louisville, KY, USA
| | - Dana K Oakes
- Department of Anatomical Sciences and Neurobiology, The University of Louisville School of Medicine, Louisville, KY, USA
| | - Sarah W Minton
- Department of Anatomical Sciences and Neurobiology, The University of Louisville School of Medicine, Louisville, KY, USA
| | - Bart G Borghuis
- Department of Anatomical Sciences and Neurobiology, The University of Louisville School of Medicine, Louisville, KY, USA
| | - Aaron W McGee
- Department of Anatomical Sciences and Neurobiology, The University of Louisville School of Medicine, Louisville, KY, USA.
- Department of Translational Neuroscience, The University of Arizona College of Medicine - Phoenix, Phoenix, AZ, USA.
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2
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Deng Q, Wu C, Parker E, Liu TCY, Duan R, Yang L. Microglia and Astrocytes in Alzheimer's Disease: Significance and Summary of Recent Advances. Aging Dis 2024; 15:1537-1564. [PMID: 37815901 PMCID: PMC11272214 DOI: 10.14336/ad.2023.0907] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Accepted: 09/07/2023] [Indexed: 10/12/2023] Open
Abstract
Alzheimer's disease, one of the most common forms of dementia, is characterized by a slow progression of cognitive impairment and neuronal loss. Currently, approved treatments for AD are hindered by various side effects and limited efficacy. Despite considerable research, practical treatments for AD have not been developed. Increasing evidence shows that glial cells, especially microglia and astrocytes, are essential in the initiation and progression of AD. During AD progression, activated resident microglia increases the ability of resting astrocytes to transform into reactive astrocytes, promoting neurodegeneration. Extensive clinical and molecular studies show the involvement of microglia and astrocyte-mediated neuroinflammation in AD pathology, indicating that microglia and astrocytes may be potential therapeutic targets for AD. This review will summarize the significant and recent advances of microglia and astrocytes in the pathogenesis of AD in three parts. First, we will review the typical pathological changes of AD and discuss microglia and astrocytes in terms of function and phenotypic changes. Second, we will describe microglia and astrocytes' physiological and pathological role in AD. These roles include the inflammatory response, "eat me" and "don't eat me" signals, Aβ seeding, propagation, clearance, synapse loss, synaptic pruning, remyelination, and demyelination. Last, we will review the pharmacological and non-pharmacological therapies targeting microglia and astrocytes in AD. We conclude that microglia and astrocytes are essential in the initiation and development of AD. Therefore, understanding the new role of microglia and astrocytes in AD progression is critical for future AD studies and clinical trials. Moreover, pharmacological, and non-pharmacological therapies targeting microglia and astrocytes, with specific studies investigating microglia and astrocyte-mediated neuronal damage and repair, may be a promising research direction for future studies regarding AD treatment and prevention.
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Affiliation(s)
- Qianting Deng
- Laboratory of Exercise and Neurobiology, School of Physical Education and Sports Science, South China Normal University, Guangzhou 510006, China.
| | - Chongyun Wu
- Laboratory of Exercise and Neurobiology, School of Physical Education and Sports Science, South China Normal University, Guangzhou 510006, China.
- Laboratory of Regenerative Medicine in Sports Science, School of Physical Education and Sports Science, South China Normal University, Guangzhou 510006, China.
| | - Emily Parker
- Medical College of Georgia at Augusta University, Augusta, GA 30912, USA.
| | - Timon Cheng-Yi Liu
- Laboratory of Laser Sports Medicine, School of Physical Education and Sports Science, South China Normal University, Guangzhou 510006, China.
| | - Rui Duan
- Laboratory of Regenerative Medicine in Sports Science, School of Physical Education and Sports Science, South China Normal University, Guangzhou 510006, China.
| | - Luodan Yang
- Laboratory of Exercise and Neurobiology, School of Physical Education and Sports Science, South China Normal University, Guangzhou 510006, China.
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3
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Baum ML, Wilton DK, Fox RG, Carey A, Hsu YHH, Hu R, Jäntti HJ, Fahey JB, Muthukumar AK, Salla N, Crotty W, Scott-Hewitt N, Bien E, Sabatini DA, Lanser TB, Frouin A, Gergits F, Håvik B, Gialeli C, Nacu E, Lage K, Blom AM, Eggan K, McCarroll SA, Johnson MB, Stevens B. CSMD1 regulates brain complement activity and circuit development. Brain Behav Immun 2024; 119:317-332. [PMID: 38552925 DOI: 10.1016/j.bbi.2024.03.041] [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: 11/20/2023] [Revised: 02/29/2024] [Accepted: 03/26/2024] [Indexed: 04/16/2024] Open
Abstract
Complement proteins facilitate synaptic elimination during neurodevelopmental pruning, but neural complement regulation is not well understood. CUB and Sushi Multiple Domains 1 (CSMD1) can regulate complement activity in vitro, is expressed in the brain, and is associated with increased schizophrenia risk. Beyond this, little is known about CSMD1 including whether it regulates complement activity in the brain or otherwise plays a role in neurodevelopment. We used biochemical, immunohistochemical, and proteomic techniques to examine the regional, cellular, and subcellular distribution as well as protein interactions of CSMD1 in the brain. To evaluate whether CSMD1 is involved in complement-mediated synapse elimination, we examined Csmd1-knockout mice and CSMD1-knockout human stem cell-derived neurons. We interrogated synapse and circuit development of the mouse visual thalamus, a process that involves complement pathway activity. We also quantified complement deposition on synapses in mouse visual thalamus and on cultured human neurons. Finally, we assessed uptake of synaptosomes by cultured microglia. We found that CSMD1 is present at synapses and interacts with complement proteins in the brain. Mice lacking Csmd1 displayed increased levels of complement component C3, an increased colocalization of C3 with presynaptic terminals, fewer retinogeniculate synapses, and aberrant segregation of eye-specific retinal inputs to the visual thalamus during the critical period of complement-dependent refinement of this circuit. Loss of CSMD1 in vivo enhanced synaptosome engulfment by microglia in vitro, and this effect was dependent on activity of the microglial complement receptor, CR3. Finally, human stem cell-derived neurons lacking CSMD1 were more vulnerable to complement deposition. These data suggest that CSMD1 can function as a regulator of complement-mediated synapse elimination in the brain during development.
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Affiliation(s)
- Matthew L Baum
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA; Department of Genetics, Harvard Medical School, Boston, MA 02115, USA; Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; MD-PhD Program of Harvard & MIT, Harvard Medical School, Boston, MA 02115, USA
| | - Daniel K Wilton
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Rachel G Fox
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Alanna Carey
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Yu-Han H Hsu
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Novo Nordisk Foundation Center for Genomic Mechanisms of Disease, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Ruilong Hu
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA; Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Henna J Jäntti
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Jaclyn B Fahey
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Allie K Muthukumar
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Nikkita Salla
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA; Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - William Crotty
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Department of Stem Cell and Regenerative Biology and Harvard Stem Cell Institute, Harvard University, Cambridge, MA 02138, USA
| | - Nicole Scott-Hewitt
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Elizabeth Bien
- Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - David A Sabatini
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Toby B Lanser
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Arnaud Frouin
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Frederick Gergits
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | | | - Chrysostomi Gialeli
- Division of Medical Protein Chemistry, Department of Translational Medicine, Lund University, S-214 28 Malmö, Sweden; Cardiovascular Research - Translational Studies Research Group, Department of Clinical Sciences, Lund University, S-214 28 Malmö, Sweden
| | - Eugene Nacu
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Novo Nordisk Foundation Center for Genomic Mechanisms of Disease, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Kasper Lage
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Novo Nordisk Foundation Center for Genomic Mechanisms of Disease, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Anna M Blom
- Division of Medical Protein Chemistry, Department of Translational Medicine, Lund University, S-214 28 Malmö, Sweden
| | - Kevin Eggan
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Department of Stem Cell and Regenerative Biology and Harvard Stem Cell Institute, Harvard University, Cambridge, MA 02138, USA
| | - Steven A McCarroll
- Department of Genetics, Harvard Medical School, Boston, MA 02115, USA; Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Matthew B Johnson
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA; Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA.
| | - Beth Stevens
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA; Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Howard Hughes Medical Institute, USA.
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Rogerson-Wood L, Goldsbury CS, Sawatari A, Leamey CA. An early enriched experience drives targeted microglial engulfment of miswired neural circuitry during a restricted postnatal period. Glia 2024; 72:1217-1235. [PMID: 38511347 DOI: 10.1002/glia.24522] [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: 10/06/2023] [Revised: 02/17/2024] [Accepted: 02/27/2024] [Indexed: 03/22/2024]
Abstract
Brain function is critically dependent on correct circuit assembly. Microglia are well-known for their important roles in immunological defense and neural plasticity, but whether they can also mediate experience-induced correction of miswired circuitry is unclear. Ten-m3 knockout (KO) mice display a pronounced and stereotyped visuotopic mismapping of ipsilateral retinal inputs in their visual thalamus, providing a useful model to probe circuit correction mechanisms. Environmental enrichment (EE) commenced around birth, but not later in life, can drive a partial correction of the most mismapped retinal inputs in Ten-m3 KO mice. Here, we assess whether enrichment unlocks the capacity for microglia to selectively engulf and remove miswired circuitry, and the timing of this effect. Expression of the microglial-associated lysosomal protein CD68 showed a clear enrichment-driven, spatially restricted change which had not commenced at postnatal day (P)18, was evident at P21, more robust at P25, and had ceased by P30. This was observed specifically at the corrective pruning site and was absent at a control site. An engulfment assay at the corrective pruning site in P25 mice showed EE-driven microglial-uptake of the mismapped axon terminals. This was temporally and spatially specific, as no enrichment-driven microglial engulfment was seen in P18 KO mice, nor the control locus. The timecourse of the EE-driven corrective pruning as determined anatomically, aligned with this pattern of microglia reactivity and engulfment. Collectively, these findings show experience can drive targeted microglial engulfment of miswired neural circuitry during a restricted postnatal window. This may have important therapeutic implications for neurodevelopmental conditions involving aberrant neural connectivity.
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Affiliation(s)
- Lara Rogerson-Wood
- School of Medical Sciences (Neuroscience theme), Faculty of Medicine and Health, University of Sydney, Sydney, New South Wales, Australia
| | - Claire S Goldsbury
- School of Medical Sciences (Neuroscience theme), Faculty of Medicine and Health, University of Sydney, Sydney, New South Wales, Australia
| | - Atomu Sawatari
- School of Medical Sciences (Neuroscience theme), Faculty of Medicine and Health, University of Sydney, Sydney, New South Wales, Australia
| | - Catherine A Leamey
- School of Medical Sciences (Neuroscience theme), Faculty of Medicine and Health, University of Sydney, Sydney, New South Wales, Australia
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5
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Huo A, Wang J, Li Q, Li M, Qi Y, Yin Q, Luo W, Shi J, Cong Q. Molecular mechanisms underlying microglial sensing and phagocytosis in synaptic pruning. Neural Regen Res 2024; 19:1284-1290. [PMID: 37905877 DOI: 10.4103/1673-5374.385854] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2023] [Accepted: 08/03/2023] [Indexed: 11/02/2023] Open
Abstract
ABSTRACT Microglia are the main non-neuronal cells in the central nervous system that have important roles in brain development and functional connectivity of neural circuits. In brain physiology, highly dynamic microglial processes are facilitated to sense the surrounding environment and stimuli. Once the brain switches its functional states, microglia are recruited to specific sites to exert their immune functions, including the release of cytokines and phagocytosis of cellular debris. The crosstalk of microglia between neurons, neural stem cells, endothelial cells, oligodendrocytes, and astrocytes contributes to their functions in synapse pruning, neurogenesis, vascularization, myelination, and blood-brain barrier permeability. In this review, we highlight the neuron-derived "find-me," "eat-me," and "don't eat-me" molecular signals that drive microglia in response to changes in neuronal activity for synapse refinement during brain development. This review reveals the molecular mechanism of neuron-microglia interaction in synaptic pruning and presents novel ideas for the synaptic pruning of microglia in disease, thereby providing important clues for discovery of target drugs and development of nervous system disease treatment methods targeting synaptic dysfunction.
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Affiliation(s)
- Anran Huo
- Clinical Research Center of Neurological Disease, The Second Affiliated Hospital of Soochow University; Institute of Neuroscience and Jiangsu Key Laboratory of Neuropsychiatric Diseases, Soochow University, Suzhou, Jiangsu Province, China
| | - Jiali Wang
- Clinical Research Center of Neurological Disease, The Second Affiliated Hospital of Soochow University; Institute of Neuroscience and Jiangsu Key Laboratory of Neuropsychiatric Diseases, Soochow University, Suzhou, Jiangsu Province, China
| | - Qi Li
- Clinical Research Center of Neurological Disease, The Second Affiliated Hospital of Soochow University; Institute of Neuroscience and Jiangsu Key Laboratory of Neuropsychiatric Diseases, Soochow University, Suzhou, Jiangsu Province, China
| | - Mengqi Li
- Clinical Research Center of Neurological Disease, The Second Affiliated Hospital of Soochow University; Institute of Neuroscience and Jiangsu Key Laboratory of Neuropsychiatric Diseases, Soochow University, Suzhou, Jiangsu Province, China
| | - Yuwan Qi
- Clinical Research Center of Neurological Disease, The Second Affiliated Hospital of Soochow University; Institute of Neuroscience and Jiangsu Key Laboratory of Neuropsychiatric Diseases, Soochow University, Suzhou, Jiangsu Province, China
| | - Qiao Yin
- Department of Neurology and Clinical Research Center of Neurological Disease, The Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu Province, China
| | - Weifeng Luo
- Department of Neurology and Clinical Research Center of Neurological Disease, The Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu Province, China
| | - Jijun Shi
- Department of Neurology and Clinical Research Center of Neurological Disease, The Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu Province, China
| | - Qifei Cong
- Clinical Research Center of Neurological Disease, The Second Affiliated Hospital of Soochow University; Institute of Neuroscience and Jiangsu Key Laboratory of Neuropsychiatric Diseases, Soochow University, Suzhou, Jiangsu Province, China
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Meng J, Zhang L, Zhang YW. Microglial Dysfunction in Autism Spectrum Disorder. Neuroscientist 2024:10738584241252576. [PMID: 38712859 DOI: 10.1177/10738584241252576] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
Autism spectrum disorder (ASD) is a highly heterogeneous neurodevelopmental disorder with onset in childhood. The molecular mechanisms underlying ASD have not yet been elucidated completely. Evidence has emerged to support a link between microglial dysfunction and the etiology of ASD. This review summarizes current research on microglial dysfunction in neuroinflammation and synaptic pruning, which are associated with altered transcriptomes and autophagy in ASD. Dysbiosis of gut microbiota in ASD and its correlation with microglial dysfunction are also addressed.
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Affiliation(s)
- Jian Meng
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, School of Medicine, Xiamen University, Xiamen, China
- Xiamen Key Laboratory of Brain Center, The First Affiliated Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen, China
| | - Lingliang Zhang
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, School of Medicine, Xiamen University, Xiamen, China
- Xiamen Key Laboratory of Brain Center, The First Affiliated Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen, China
| | - Yun-Wu Zhang
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, School of Medicine, Xiamen University, Xiamen, China
- Xiamen Key Laboratory of Brain Center, The First Affiliated Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen, China
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7
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Wang G, Liu HY, Meng XW, Chen Y, Zhao WM, Li WT, Xu HB, Peng K, Ji FH. Complement C1q-mediated microglial synaptic elimination by enhancing desialylation underlies sevoflurane-induced developmental neurotoxicity. Cell Biosci 2024; 14:42. [PMID: 38556890 PMCID: PMC10983687 DOI: 10.1186/s13578-024-01223-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Accepted: 03/25/2024] [Indexed: 04/02/2024] Open
Abstract
BACKGROUND Repeated neonatal sevoflurane exposures led to neurocognitive disorders in young mice. We aimed to assess the role of microglia and complement C1q in sevoflurane-induced neurotoxicity and explore the underlying mechanisms. METHODS Neonatal mice were treated with sevoflurane on postnatal days 6, 8, and 10, and the Morris water maze was performed to assess cognitive functions. For mechanistic explorations, mice were treated with minocycline, C1q-antibody ANX005, and sialidase-inhibitor N-acetyl-2,3-dehydro-2-deoxyneuraminic acid (NADNA) before sevoflurane exposures. Western blotting, RT-qPCR, Golgi staining, 3D reconstruction and engulfment analysis, immunofluorescence, and microglial morphology analysis were performed. In vitro experiments were conducted in microglial cell line BV2 cells. RESULTS Repeated neonatal sevoflurane exposures resulted in deficiencies in learning and cognition of young mice, accompanied by microglial activation and synapse loss. Sevoflurane enhanced microglia-mediated synapse elimination through C1q binding to synapses. Inhibition of microglial activation and phagocytosis with minocycline significantly reduced the loss of synapses. We further revealed the involvement of neuronal sialic acids in this process. The enhanced activity of sialidase by sevoflurane led to the loss of sialic acids, which facilitated C1q binding to synapses. Inhibition of C1q with ANX005 or inhibition of sialidase with NADNA significantly rescued microglia-mediated synapse loss and improved neurocognitive function. Sevoflurane enhanced the engulfment of BV2 cells, which was reversed by ANX005. CONCLUSIONS Our findings demonstrated that C1q-mediated microglial synaptic elimination by enhancing desialylation contributed to sevoflurane-induced developmental neurotoxicity. Inhibition of C1q or sialidase may be a potential therapeutic strategy for this neurotoxicity.
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Affiliation(s)
- Gang Wang
- Department of Anesthesiology, First Affiliated Hospital of Soochow University, 188 Shizi Street, Suzhou, 215006, Jiangsu, China
- Institute of Anesthesiology, Soochow University, Suzhou, 215006, Jiangsu, China
| | - Hua-Yue Liu
- Department of Anesthesiology, First Affiliated Hospital of Soochow University, 188 Shizi Street, Suzhou, 215006, Jiangsu, China
- Institute of Anesthesiology, Soochow University, Suzhou, 215006, Jiangsu, China
- Ambulatory Surgery Center, First Affiliated Hospital of Soochow University, Suzhou, 215006, Jiangsu, China
| | - Xiao-Wen Meng
- Department of Anesthesiology, First Affiliated Hospital of Soochow University, 188 Shizi Street, Suzhou, 215006, Jiangsu, China
- Institute of Anesthesiology, Soochow University, Suzhou, 215006, Jiangsu, China
| | - Ying Chen
- Departments of Neurology, First Affiliated Hospital of Soochow University, Suzhou, 215006, Jiangsu, China
| | - Wei-Ming Zhao
- Department of Anesthesiology, First Affiliated Hospital of Soochow University, 188 Shizi Street, Suzhou, 215006, Jiangsu, China
- Institute of Anesthesiology, Soochow University, Suzhou, 215006, Jiangsu, China
| | - Wen-Ting Li
- Department of Anesthesiology, First Affiliated Hospital of Soochow University, 188 Shizi Street, Suzhou, 215006, Jiangsu, China
- Institute of Anesthesiology, Soochow University, Suzhou, 215006, Jiangsu, China
| | - Han-Bing Xu
- Department of Anesthesiology, First Affiliated Hospital of Soochow University, 188 Shizi Street, Suzhou, 215006, Jiangsu, China
- Institute of Anesthesiology, Soochow University, Suzhou, 215006, Jiangsu, China
| | - Ke Peng
- Department of Anesthesiology, First Affiliated Hospital of Soochow University, 188 Shizi Street, Suzhou, 215006, Jiangsu, China.
- Institute of Anesthesiology, Soochow University, Suzhou, 215006, Jiangsu, China.
| | - Fu-Hai Ji
- Department of Anesthesiology, First Affiliated Hospital of Soochow University, 188 Shizi Street, Suzhou, 215006, Jiangsu, China.
- Institute of Anesthesiology, Soochow University, Suzhou, 215006, Jiangsu, China.
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8
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Durán Laforet V, Schafer DP. Microglia: Activity-dependent regulators of neural circuits. Ann N Y Acad Sci 2024; 1533:38-50. [PMID: 38294960 PMCID: PMC10976428 DOI: 10.1111/nyas.15105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2024]
Abstract
It has been more than a century since Pío del Río-Hortega first characterized microglia in histological stains of brain tissue. Since then, significant advances have been made in understanding the role of these resident central nervous system (CNS) macrophages. In particular, it is now known that microglia can sense neural activity and modulate neuronal circuits accordingly. We review the mechanisms by which microglia detect changes in neural activity to then modulate synapse numbers in the developing and mature CNS. This includes responses to both spontaneous and experience-driven neural activity. We further discuss activity-dependent mechanisms by which microglia regulate synaptic function and neural circuit excitability. Together, our discussion provides a comprehensive review of the activity-dependent functions of microglia within neural circuits in the healthy CNS, and highlights exciting new open questions related to understanding more fully microglia as key components and regulators of neural circuits.
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Affiliation(s)
- Violeta Durán Laforet
- Department of Neurobiology, Brudnick Neuropsychiatric Research Institute, University of Massachusetts Chan Medical School, Worcester, Massachusetts, USA
| | - Dorothy P Schafer
- Department of Neurobiology, Brudnick Neuropsychiatric Research Institute, University of Massachusetts Chan Medical School, Worcester, Massachusetts, USA
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9
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You Y, Chen Z, Hu WW. The role of microglia heterogeneity in synaptic plasticity and brain disorders: Will sequencing shed light on the discovery of new therapeutic targets? Pharmacol Ther 2024; 255:108606. [PMID: 38346477 DOI: 10.1016/j.pharmthera.2024.108606] [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: 10/31/2023] [Revised: 01/05/2024] [Accepted: 02/02/2024] [Indexed: 02/18/2024]
Abstract
Microglia play a crucial role in interacting with neuronal synapses and modulating synaptic plasticity. This function is particularly significant during postnatal development, as microglia are responsible for removing excessive synapses to prevent neurodevelopmental deficits. Dysregulation of microglial synaptic function has been well-documented in various pathological conditions, notably Alzheimer's disease and multiple sclerosis. The recent application of RNA sequencing has provided a powerful and unbiased means to decipher spatial and temporal microglial heterogeneity. By identifying microglia with varying gene expression profiles, researchers have defined multiple subgroups of microglia associated with specific pathological states, including disease-associated microglia, interferon-responsive microglia, proliferating microglia, and inflamed microglia in multiple sclerosis, among others. However, the functional roles of these distinct subgroups remain inadequately characterized. This review aims to refine our current understanding of the potential roles of heterogeneous microglia in regulating synaptic plasticity and their implications for various brain disorders, drawing from recent sequencing research and functional studies. This knowledge may aid in the identification of pathogenetic biomarkers and potential factors contributing to pathogenesis, shedding new light on the discovery of novel drug targets. The field of sequencing-based data mining is evolving toward a multi-omics approach. With advances in viral tools for precise microglial regulation and the development of brain organoid models, we are poised to elucidate the functional roles of microglial subgroups detected through sequencing analysis, ultimately identifying valuable therapeutic targets.
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Affiliation(s)
- Yi You
- Department of Pharmacology and Department of Pharmacy of the Second Affiliated Hospital, Key Laboratory of Medical Neurobiology of the Ministry of Health of China, School of Basic Medical Sciences, Zhejiang University School of Medicine, Hangzhou 310058, China
| | - Zhong Chen
- Department of Pharmacology and Department of Pharmacy of the Second Affiliated Hospital, Key Laboratory of Medical Neurobiology of the Ministry of Health of China, School of Basic Medical Sciences, Zhejiang University School of Medicine, Hangzhou 310058, China; Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, Zhejiang Chinese Medical University, Hangzhou 310053, China
| | - Wei-Wei Hu
- Department of Pharmacology and Department of Pharmacy of the Second Affiliated Hospital, Key Laboratory of Medical Neurobiology of the Ministry of Health of China, School of Basic Medical Sciences, Zhejiang University School of Medicine, Hangzhou 310058, China.
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10
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Matuleviciute R, Akinluyi ET, Muntslag TAO, Dewing JM, Long KR, Vernon AC, Tremblay ME, Menassa DA. Microglial contribution to the pathology of neurodevelopmental disorders in humans. Acta Neuropathol 2023; 146:663-683. [PMID: 37656188 PMCID: PMC10564830 DOI: 10.1007/s00401-023-02629-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Revised: 08/25/2023] [Accepted: 08/26/2023] [Indexed: 09/02/2023]
Abstract
Microglia are the brain's resident macrophages, which guide various developmental processes crucial for brain maturation, activity, and plasticity. Microglial progenitors enter the telencephalic wall by the 4th postconceptional week and colonise the fetal brain in a manner that spatiotemporally tracks key neurodevelopmental processes in humans. However, much of what we know about how microglia shape neurodevelopment comes from rodent studies. Multiple differences exist between human and rodent microglia warranting further focus on the human condition, particularly as microglia are emerging as critically involved in the pathological signature of various cognitive and neurodevelopmental disorders. In this article, we review the evidence supporting microglial involvement in basic neurodevelopmental processes by focusing on the human species. We next concur on the neuropathological evidence demonstrating whether and how microglia contribute to the aetiology of two neurodevelopmental disorders: autism spectrum conditions and schizophrenia. Next, we highlight how recent technologies have revolutionised our understanding of microglial biology with a focus on how these tools can help us elucidate at unprecedented resolution the links between microglia and neurodevelopmental disorders. We conclude by reviewing which current treatment approaches have shown most promise towards targeting microglia in neurodevelopmental disorders and suggest novel avenues for future consideration.
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Affiliation(s)
- Rugile Matuleviciute
- MRC Centre for Neurodevelopmental Disorders, King's College London, London, UK
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Elizabeth T Akinluyi
- Division of Medical Sciences, University of Victoria, Victoria, Canada
- Department of Pharmacology and Therapeutics, Afe Babalola University, Ado Ekiti, Nigeria
| | - Tim A O Muntslag
- Princess Maxima Centre for Paediatric Oncology, Utrecht, The Netherlands
| | | | - Katherine R Long
- MRC Centre for Neurodevelopmental Disorders, King's College London, London, UK
- Centre for Developmental Neurobiology, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Anthony C Vernon
- MRC Centre for Neurodevelopmental Disorders, King's College London, London, UK
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | | | - David A Menassa
- Department of Neuropathology & The Queen's College, University of Oxford, Oxford, UK.
- Department of Women's and Children's Health, Karolinska Institutet, Solna, Sweden.
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11
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Brown TC, Crouse EC, Attaway CA, Oakes DK, Minton SW, Borghuis BG, McGee AW. Microglia are dispensable for experience-dependent refinement of visual circuitry. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.17.562708. [PMID: 37905138 PMCID: PMC10614920 DOI: 10.1101/2023.10.17.562708] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/02/2023]
Abstract
Microglia are proposed to be critical for the refinement of developing neural circuitry. However, evidence identifying specific roles for microglia has been limited and often indirect. Here we examined whether microglia are required for the experience-dependent refinement of visual circuitry and visual function during development. We ablated microglia by administering the colony-stimulating factor 1 receptor (CSF1R) inhibitor PLX5622, and then examined the consequences for retinal function, receptive field tuning of neurons in primary visual cortex (V1), visual acuity, and experience-dependent plasticity in visual circuitry. Eradicating microglia by treating mice with PLX5622 beginning at postnatal day (P) 14 did not alter visual response properties of retinal ganglion cells examined three or more weeks later. Mice treated with PLX5622 from P14 lacked more than 95% of microglia in V1 by P18, prior to the opening of the critical period. Despite the absence of microglia, the receptive field tuning properties of neurons in V1 were normal at P32. Similarly, eradicating microglia did not affect the maturation of visual acuity. Mice treated with PLX5622 displayed typical ocular dominance plasticity in response to brief monocular deprivation. Thus, none of these principal measurements of visual circuit development and function detectibly differed in the absence of microglia. We conclude that microglia are dispensable for experience-dependent refinement of visual circuitry. These findings challenge the proposed critical role of microglia in refining neural circuitry.
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Affiliation(s)
- Thomas C. Brown
- Department of Anatomical Sciences and Neurobiology, School of Medicine; University of Louisville, Louisville, KY, 40202
| | - Emily C. Crouse
- Department of Anatomical Sciences and Neurobiology, School of Medicine; University of Louisville, Louisville, KY, 40202
| | - Cecilia A. Attaway
- Department of Anatomical Sciences and Neurobiology, School of Medicine; University of Louisville, Louisville, KY, 40202
| | - Dana K. Oakes
- Department of Anatomical Sciences and Neurobiology, School of Medicine; University of Louisville, Louisville, KY, 40202
| | - Sarah W. Minton
- Department of Anatomical Sciences and Neurobiology, School of Medicine; University of Louisville, Louisville, KY, 40202
| | - Bart G. Borghuis
- Department of Anatomical Sciences and Neurobiology, School of Medicine; University of Louisville, Louisville, KY, 40202
| | - Aaron W. McGee
- Department of Anatomical Sciences and Neurobiology, School of Medicine; University of Louisville, Louisville, KY, 40202
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12
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Soteros BM, Tillmon H, Wollet M, General J, Chin H, Lee JB, Carreno FR, Morilak DA, Kim JH, Sia GM. Heterogeneous complement and microglia activation mediates stress-induced synapse loss. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.28.546889. [PMID: 37425856 PMCID: PMC10327081 DOI: 10.1101/2023.06.28.546889] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/11/2023]
Abstract
Spatially heterogeneous synapse loss is a characteristic of many psychiatric and neurological disorders, but the underlying mechanisms are unclear. Here, we show that spatially-restricted complement activation mediates stress-induced heterogeneous microglia activation and synapse loss localized to the upper layers of the mouse medial prefrontal cortex (mPFC). Single cell RNA sequencing also reveals a stress-associated microglia state marked by high expression of the apolipoprotein E gene (ApoE high ) localized to the upper layers of the mPFC. Mice lacking complement component C3 are protected from stress-induced layer-specific synapse loss, and the ApoE high microglia population is markedly reduced in the mPFC of these mice. Furthermore, C3 knockout mice are also resilient to stress-induced anhedonia and working memory behavioral deficits. Our findings suggest that region-specific complement and microglia activation can contribute to the disease-specific spatially restricted patterns of synapse loss and clinical symptoms found in many brain diseases.
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13
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Nagappan-Chettiar S, Burbridge TJ, Umemori H. Activity-Dependent Synapse Refinement: From Mechanisms to Molecules. Neuroscientist 2023:10738584231170167. [PMID: 37140155 DOI: 10.1177/10738584231170167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
The refinement of immature neuronal networks into efficient mature ones is critical to nervous system development and function. This process of synapse refinement is driven by the neuronal activity-dependent competition of converging synaptic inputs, resulting in the elimination of weak inputs and the stabilization of strong ones. Neuronal activity, whether in the form of spontaneous activity or experience-evoked activity, is known to drive synapse refinement in numerous brain regions. More recent studies are now revealing the manner and mechanisms by which neuronal activity is detected and converted into molecular signals that appropriately regulate the elimination of weaker synapses and stabilization of stronger ones. Here, we highlight how spontaneous activity and evoked activity instruct neuronal activity-dependent competition during synapse refinement. We then focus on how neuronal activity is transformed into the molecular cues that determine and execute synapse refinement. A comprehensive understanding of the mechanisms underlying synapse refinement can lead to novel therapeutic strategies in neuropsychiatric diseases characterized by aberrant synaptic function.
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Affiliation(s)
- Sivapratha Nagappan-Chettiar
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Timothy J Burbridge
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Hisashi Umemori
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
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14
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Nagappan-Chettiar S, Yasuda M, Johnson-Venkatesh EM, Umemori H. The molecular signals that regulate activity-dependent synapse refinement in the brain. Curr Opin Neurobiol 2023; 79:102692. [PMID: 36805716 PMCID: PMC10023433 DOI: 10.1016/j.conb.2023.102692] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Revised: 12/11/2022] [Accepted: 01/10/2023] [Indexed: 02/19/2023]
Abstract
The formation of appropriate synaptic connections is critical for the proper functioning of the brain. Early in development, neurons form a surplus of immature synapses. To establish efficient, functional neural networks, neurons selectively stabilize active synapses and eliminate less active ones. This process is known as activity-dependent synapse refinement. Defects in this process have been implicated in neuropsychiatric disorders such as schizophrenia and autism. Here we review the manner and mechanisms by which synapse elimination is regulated through activity-dependent competition. We propose a theoretical framework for the molecular mechanisms of synapse refinement, in which three types of signals regulate the refinement. We then describe the identity of these signals and discuss how multiple molecular signals interact to achieve appropriate synapse refinement in the brain.
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Affiliation(s)
- Sivapratha Nagappan-Chettiar
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA. https://twitter.com/sivapratha
| | - Masahiro Yasuda
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Erin M Johnson-Venkatesh
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Hisashi Umemori
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA.
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15
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Botulinum neurotoxin A ameliorates depressive-like behavior in a reserpine-induced Parkinson's disease mouse model via suppressing hippocampal microglial engulfment and neuroinflammation. Acta Pharmacol Sin 2023:10.1038/s41401-023-01058-x. [PMID: 36765267 DOI: 10.1038/s41401-023-01058-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2022] [Accepted: 01/16/2023] [Indexed: 02/12/2023] Open
Abstract
Depression is one of the common non-motor symptoms of Parkinson's disease (PD). In the clinic, botulinum neurotoxin A (BoNT/A) has been used to treat depression. In this study, we investigated the mechanisms underlying the anti-depressive effect of BoNT/A in a PD mouse model. Mice were administered reserpine (3 μg/mL in the drinking water) for 10 weeks. From the 10th week, BoNT/A (10 U·kg-1·d-1) was injected into the cheek for 3 consecutive days. We showed that chronic administration of reserpine produced the behavioral phenotypes of depression and neurochemical changes in the substantia nigra pars compacta (SNpc) and striatum. BoNT/A treatment significantly ameliorated the depressive-like behaviors, but did not improve TH activity in SNpc of reserpine-treated mice. We demonstrated that BoNT/A treatment reversed reserpine-induced complement and microglia activation in the hippocampal CA1 region. Furthermore, BoNT/A treatment significantly attenuated the microglial engulfment of presynaptic synapses, thus ameliorating the apparent synapse and spine loss in the hippocampus in the reserpine-treated mice. Moreover, BoNT/A treatment suppressed microglia-mediated expression of pro-inflammatory cytokines TNF-α and IL-1β in reserpine-treated mice. In addition, we showed that BoNT/A (0.1 U/mL) ameliorated reserpine-induced complement and microglia activation in mouse BV2 microglial cells in vitro. We conclude that BoNT/A ameliorates depressive-like behavior in a reserpine-induced PD mouse model through reversing the synapse loss mediated by classical complement induced-microglial engulfment as well as alleviating microglia-mediated proinflammatory responses. BoNT/A ameliorates depressive-like behavior, and reverses synapse loss mediated by classical complement pathway-initiated microglia engulfment as well as alleviates microglia-mediated proinflammatory response in the reserpine-induced Parkinson's disease mouse model.
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16
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Li J, Wang Y, Yuan X, Kang Y, Song X. New insight in the cross-talk between microglia and schizophrenia: From the perspective of neurodevelopment. Front Psychiatry 2023; 14:1126632. [PMID: 36873215 PMCID: PMC9978517 DOI: 10.3389/fpsyt.2023.1126632] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2022] [Accepted: 01/27/2023] [Indexed: 02/18/2023] Open
Abstract
Characterized by psychotic symptoms, negative symptoms and cognitive deficits, schizophrenia had a catastrophic effect on patients and their families. Multifaceted reliable evidence indicated that schizophrenia is a neurodevelopmental disorder. Microglia, the immune cells in central nervous system, related to many neurodevelopmental diseases. Microglia could affect neuronal survival, neuronal death and synaptic plasticity during neurodevelopment. Anomalous microglia during neurodevelopment may be associated with schizophrenia. Therefore, a hypothesis proposes that the abnormal function of microglia leads to the occurrence of schizophrenia. Nowadays, accumulating experiments between microglia and schizophrenia could afford unparalleled probability to assess this hypothesis. Herein, this review summarizes the latest supporting evidence in order to shed light on the mystery of microglia in schizophrenia.
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Affiliation(s)
- Jingjing Li
- Department of Psychiatry, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China.,Henan International Joint Laboratory of Biological Psychiatry, Zhengzhou, China.,Henan Psychiatric Transformation Research Key Laboratory, Zhengzhou University, Zhengzhou, China
| | - Yu Wang
- College of First Clinical, Chongqing Medical University, Chongqing, China
| | - Xiuxia Yuan
- Department of Psychiatry, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China.,Henan International Joint Laboratory of Biological Psychiatry, Zhengzhou, China.,Henan Psychiatric Transformation Research Key Laboratory, Zhengzhou University, Zhengzhou, China
| | - Yulin Kang
- Institute of Environmental Information, Chinese Research Academy of Environmental Sciences, Beijing, China
| | - Xueqin Song
- Department of Psychiatry, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China.,Henan International Joint Laboratory of Biological Psychiatry, Zhengzhou, China.,Henan Psychiatric Transformation Research Key Laboratory, Zhengzhou University, Zhengzhou, China
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17
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Zhang W, Chen Y, Pei H. C1q and central nervous system disorders. Front Immunol 2023; 14:1145649. [PMID: 37033981 PMCID: PMC10076750 DOI: 10.3389/fimmu.2023.1145649] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Accepted: 03/07/2023] [Indexed: 04/11/2023] Open
Abstract
C1q is a crucial component of the complement system, which is activated through the classical pathway to perform non-specific immune functions, serving as the first line of defense against pathogens. C1q can also bind to specific receptors to carry out immune and other functions, playing a vital role in maintaining immune homeostasis and normal physiological functions. In the developing central nervous system (CNS), C1q functions in synapse formation and pruning, serving as a key player in the development and homeostasis of neuronal networks in the CNS. C1q has a close relationship with microglia and astrocytes, and under their influence, C1q may contribute to the development of CNS disorders. Furthermore, C1q can also have independent effects on neurological disorders, producing either beneficial or detrimental outcomes. Most of the evidence for these functions comes from animal models, with some also from human specimen studies. C1q is now emerging as a promising target for the treatment of a variety of diseases, and clinical trials are already underway for CNS disorders. This article highlights the role of C1q in CNS diseases, offering new directions for the diagnosis and treatment of these conditions.
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Affiliation(s)
- Wenjie Zhang
- Department of Emergency Intensive Care Unit, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
- Department of General Practice, Xingyang Sishui Central Health Center, Zhengzhou, China
| | - Yuan Chen
- Department of Neurology, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Hui Pei
- Department of Emergency Intensive Care Unit, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
- *Correspondence: Hui Pei,
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18
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Schulz K, Trendelenburg M. C1q as a target molecule to treat human disease: What do mouse studies teach us? Front Immunol 2022; 13:958273. [PMID: 35990646 PMCID: PMC9385197 DOI: 10.3389/fimmu.2022.958273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Accepted: 06/24/2022] [Indexed: 11/17/2022] Open
Abstract
The complement system is a field of growing interest for pharmacological intervention. Complement protein C1q, the pattern recognition molecule at the start of the classical pathway of the complement cascade, is a versatile molecule with additional non-canonical actions affecting numerous cellular processes. Based on observations made in patients with hereditary C1q deficiency, C1q is protective against systemic autoimmunity and bacterial infections. Accordingly, C1q deficient mice reproduce this phenotype with susceptibility to autoimmunity and infections. At the same time, beneficial effects of C1q deficiency on disease entities such as neurodegenerative diseases have also been described in murine disease models. This systematic review provides an overview of all currently available literature on the C1q knockout mouse in disease models to identify potential target diseases for treatment strategies focusing on C1q, and discusses potential side-effects when depleting and/or inhibiting C1q.
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Affiliation(s)
- Kristina Schulz
- Laboratory of Clinical Immunology, Department of Biomedicine, University of Basel, Basel, Switzerland
- Division of Internal Medicine, University Hospital Basel, Basel, Switzerland
- *Correspondence: Kristina Schulz,
| | - Marten Trendelenburg
- Laboratory of Clinical Immunology, Department of Biomedicine, University of Basel, Basel, Switzerland
- Division of Internal Medicine, University Hospital Basel, Basel, Switzerland
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19
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Paasila PJ, Aramideh JA, Sutherland GT, Graeber MB. Synapses, Microglia, and Lipids in Alzheimer's Disease. Front Neurosci 2022; 15:778822. [PMID: 35095394 PMCID: PMC8789683 DOI: 10.3389/fnins.2021.778822] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Accepted: 12/06/2021] [Indexed: 12/17/2022] Open
Abstract
Alzheimer's disease (AD) is characterised by synaptic dysfunction accompanied by the microscopically visible accumulation of pathological protein deposits and cellular dystrophy involving both neurons and glia. Late-stage AD shows pronounced loss of synapses and neurons across several differentially affected brain regions. Recent studies of advanced AD using post-mortem brain samples have demonstrated the direct involvement of microglia in synaptic changes. Variants of the Apolipoprotein E and Triggering Receptors Expressed on Myeloid Cells gene represent important determinants of microglial activity but also of lipid metabolism in cells of the central nervous system. Here we review evidence that may help to explain how abnormal lipid metabolism, microglial activation, and synaptic pathophysiology are inter-related in AD.
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Affiliation(s)
- Patrick J. Paasila
- Charles Perkins Centre, School of Medical Sciences, Faculty of Medicine and Health, The University of Sydney, Camperdown, NSW, Australia
- School of Medicine, Western Sydney University, Campbelltown, NSW, Australia
| | - Jason A. Aramideh
- Brain and Mind Centre, Faculty of Medicine and Health, The University of Sydney, Camperdown, NSW, Australia
| | - Greg T. Sutherland
- Charles Perkins Centre, School of Medical Sciences, Faculty of Medicine and Health, The University of Sydney, Camperdown, NSW, Australia
| | - Manuel B. Graeber
- Brain and Mind Centre, Faculty of Medicine and Health, The University of Sydney, Camperdown, NSW, Australia
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