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Iovino L, VanderZwaag J, Kaur G, Khakpour M, Giusti V, Donadon M, Chiavegato A, Tenorio-Lopes L, Greggio E, Tremblay ME, Civiero L. Investigation of microglial diversity in a LRRK2 G2019S mouse model of Parkinson's disease. Neurobiol Dis 2024; 195:106481. [PMID: 38527708 DOI: 10.1016/j.nbd.2024.106481] [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: 11/10/2023] [Revised: 02/15/2024] [Accepted: 03/21/2024] [Indexed: 03/27/2024] Open
Abstract
Microglia contribute to the outcomes of various pathological conditions including Parkinson's disease (PD). Microglia are heterogenous, with a variety of states recently identified in aging and neurodegenerative disease models. Here, we delved into the diversity of microglia in a preclinical PD model featuring the G2019S mutation in LRRK2, a known pathological mutation associated with PD. Specifically, we investigated the 'dark microglia' (DM) and the 'disease-associated microglia' (DAM) which present a selective enrichment of CLEC7A expression. In the dorsal striatum - a region affected by PD pathology - extensive ultrastructural features of cellular stress as well as reduced direct cellular contacts, were observed for microglia from old LRRK2 G2019S mice versus controls. In addition, DM were more prevalent while CLEC7A-positive microglia had extensive phagocytic ultrastructural characteristics in the LRRK2 G2019S mice. Furthermore, our findings revealed a higher proportion of DM in LRRK2 G2019S mice, and an increased number of CLEC7A-positive cells with age, exacerbated by the pathological mutation. These CLEC7A-positive cells exhibited a selective enrichment of ameboid morphology and tended to cluster in the affected animals. In summary, we provide novel insights into the occurrence and features of recently defined microglial states, CLEC7A-positive cells and DM, in the context of LRRK2 G2019S PD pathology.
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Affiliation(s)
- L Iovino
- National Research Council (CNR), Institute of Neuroscience, Pisa, Italy; Stella Maris Foundation, IRCCS, Calambrone, Pisa, Italy
| | - J VanderZwaag
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada; Neuroscience Graduate Program, University of Victoria, Victoria, BC, Canada
| | - G Kaur
- University of Padua, Department of Biology, Padova, Italy
| | - M Khakpour
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
| | - V Giusti
- University of Padua, Department of Biology, Padova, Italy; San Camillo Hospital srl Società unipersonale, IRCCS, Venice, Italy
| | - M Donadon
- University of Padua, Department of Biology, Padova, Italy
| | - A Chiavegato
- National Research Council (CNR), Neuroscience Institute, Section of Padova, Padova, Italy; Università degli Studi di Padova, Department of Biomedical Sciences, Padova, Italy
| | - L Tenorio-Lopes
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
| | - E Greggio
- University of Padua, Department of Biology, Padova, Italy; University of Padova, Study Center for Neurodegeneration (CESNE), Padova, Italy
| | - M E Tremblay
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada; Département de médecine moléculaire, Université Laval, Québec City, QC, Canada; Axe Neurosciences, Centre de Recherche du CHU de Québec, Université Laval, Québec City, QC, Canada; Neurology and Neurosurgery Department, McGill University, Montreal, QC, Canada; Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, BC, Canada; Centre for Advanced Materials and Related Technology (CAMTEC), University of Victoria, Victoria, BC, Canada; Institute for Aging and Lifelong Health, University of Victoria, Victoria, BC, Canada
| | - L Civiero
- University of Padua, Department of Biology, Padova, Italy; San Camillo Hospital srl Società unipersonale, IRCCS, Venice, Italy.
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2
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St-Pierre MK, González Ibáñez F, Kroner A, Tremblay MÈ. Microglia/macrophages are ultrastructurally altered by their proximity to spinal cord injury in adult female mice. J Neuroinflammation 2023; 20:273. [PMID: 37990235 PMCID: PMC10664529 DOI: 10.1186/s12974-023-02953-0] [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: 07/28/2023] [Accepted: 11/08/2023] [Indexed: 11/23/2023] Open
Abstract
Traumatic spinal cord injury can cause immediate physical damage to the spinal cord and result in severe neurological deficits. The primary, mechanical tissue damage triggers a variety of secondary damage mechanisms at the injury site which significantly contribute to a larger lesion size and increased functional damage. Inflammatory mechanisms which directly involve both microglia (MG) and monocyte-derived macrophages (MDM) play important roles in the post-injury processes, including inflammation and debris clearing. In the current study, we investigated changes in the structure and function of MG/MDM in the injured spinal cord of adult female mice, 7 days after a thoracic contusion SCI. With the use of chip mapping scanning electron microscopy, which allows to image large samples at the nanoscale, we performed an ultrastructural comparison of MG/MDM located near the lesion vs adjacent regions to provide novel insights into the mechanisms at play post-injury. We found that MG/MDM located near the lesion had more mitochondria overall, including mitochondria with and without morphological alterations, and had a higher proportion of altered mitochondria. MG/MDM near the lesion also showed an increased number of phagosomes, including phagosomes containing myelin and partiallydigested materials. MG/MDM near the injury interacted differently with the spinal cord parenchyma, as shown by their reduced number of direct contacts with synaptic elements, axon terminals and dendritic spines. In this study, we characterized the ultrastructural changes of MG/MDM in response to spinal cord tissue damage in mice, uncovering changes in phagocytic activity, mitochondrial ultrastructure, and inter-cellular interactions within the spinal cord parenchyma.
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Affiliation(s)
- Marie-Kim St-Pierre
- Axe Neurosciences, Centre de Recherche du CHU de Québec-Université Laval, Québec City, QC, Canada
- Department of Molecular Medicine, Université Laval, Québec City, QC, Canada
- Division of Medical Sciences, University of Victoria, 3800 Finnerty Road, Victoria, BC, V8P 5C2, Canada
| | - Fernando González Ibáñez
- Axe Neurosciences, Centre de Recherche du CHU de Québec-Université Laval, Québec City, QC, Canada
- Department of Molecular Medicine, Université Laval, Québec City, QC, Canada
- Division of Medical Sciences, University of Victoria, 3800 Finnerty Road, Victoria, BC, V8P 5C2, Canada
| | - Antje Kroner
- Department of Neurosurgery, Medical College of Wisconsin, Milwaukee, WI, USA.
- Department of Microbiology and Immunology, Medical College of Wisconsin, Milwaukee, WI, USA.
- Clement J. Zablocki Veterans Affairs Medical Center, 5000 W. National Ave, Milwaukee, WI, 53295, USA.
| | - Marie-Ève Tremblay
- Axe Neurosciences, Centre de Recherche du CHU de Québec-Université Laval, Québec City, QC, Canada.
- Department of Molecular Medicine, Université Laval, Québec City, QC, Canada.
- Division of Medical Sciences, University of Victoria, 3800 Finnerty Road, Victoria, BC, V8P 5C2, Canada.
- Department of Biochemistry and Molecular Biology, The University of British Columbia, Vancouver, BC, Canada.
- Department of Neurology and Neurosurgery, McGill University, Montréal, QC, Canada.
- Centre for Advanced Materials and Related Technology (CAMTEC) and Institute on Aging and Lifelong Health (IALH), University of Victoria, Victoria, BC, Canada.
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3
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Wang J, He W, Zhang J. A richer and more diverse future for microglia phenotypes. Heliyon 2023; 9:e14713. [PMID: 37025898 PMCID: PMC10070543 DOI: 10.1016/j.heliyon.2023.e14713] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Revised: 03/01/2023] [Accepted: 03/15/2023] [Indexed: 03/29/2023] Open
Abstract
Microglia are the only resident innate immune cells derived from the mesoderm in the nerve tissue. They play a role in the development and maturation of the central nervous system (CNS). Microglia mediate the repair of CNS injury and participate in endogenous immune response induced by various diseases by exerting neuroprotective or neurotoxic effects. Traditionally, microglia are considered to be in a resting state, the M0 type, under physiological conditions. In this state, they perform immune surveillance by constantly monitoring pathological responses in the CNS. In the pathological state, microglia undergo a series of morphological and functional changes from the M0 state and eventually polarize into classically activated microglia (M1) and alternatively activated microglia (M2). M1 microglia release inflammatory factors and toxic substances to inhibit pathogens, while M2 microglia exert neuroprotective effects by promoting nerve repair and regeneration. However, in recent years, the view regarding M1/M2 polarization of microglia has gradually changed. According to some researchers, the phenomenon of microglia polarization is not yet confirmed. The M1/M2 polarization term is used for a simplified description of its phenotype and function. Other researchers believe that the microglia polarization process is rich and diverse, and consequently, the classification method of M1/M2 has limitations. This conflict hinders the academic community from establishing more meaningful microglia polarization pathways and terms, and therefore, a careful revision of the concept of microglia polarization is required. The present article briefly reviews the current consensus and controversy regarding microglial polarization typing to provide supporting materials for a more objective understanding of the functional phenotype of microglia.
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4
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St-Pierre MK, Carrier M, González Ibáñez F, Khakpour M, Wallman MJ, Parent M, Tremblay MÈ. Astrocytes display ultrastructural alterations and heterogeneity in the hippocampus of aged APP-PS1 mice and human post-mortem brain samples. J Neuroinflammation 2023; 20:73. [PMID: 36918925 PMCID: PMC10015698 DOI: 10.1186/s12974-023-02752-7] [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: 12/15/2022] [Accepted: 02/24/2023] [Indexed: 03/16/2023] Open
Abstract
The past decade has witnessed increasing evidence for a crucial role played by glial cells, notably astrocytes, in Alzheimer's disease (AD). To provide novel insights into the roles of astrocytes in the pathophysiology of AD, we performed a quantitative ultrastructural characterization of their intracellular contents and parenchymal interactions in an aged mouse model of AD pathology, as aging is considered the main risk factor for developing AD. We compared 20-month-old APP-PS1 and age-matched C57BL/6J male mice, among the ventral hippocampus CA1 strata lacunosum-moleculare and radiatum, two hippocampal layers severely affected by AD pathology. Astrocytes in both layers interacted more with synaptic elements and displayed more ultrastructural markers of increased phagolysosomal activity in APP-PS1 versus C57BL6/J mice. In addition, we investigated the ultrastructural heterogeneity of astrocytes, describing in the two examined layers a dark astrocytic state that we characterized in terms of distribution, interactions with AD hallmarks, and intracellular contents. This electron-dense astrocytic state, termed dark astrocytes, was observed throughout the hippocampal parenchyma, closely associated with the vasculature, and possessed several ultrastructural markers of cellular stress. A case study exploring the hippocampal head of an aged human post-mortem brain sample also revealed the presence of a similar electron-dense, dark astrocytic state. Overall, our study provides the first ultrastructural quantitative analysis of astrocytes among the hippocampus in aged AD pathology, as well as a thorough characterization of a dark astrocytic state conserved from mouse to human.
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Affiliation(s)
- Marie-Kim St-Pierre
- Axe Neurosciences, Centre de Recherche du CHU de Québec-Université Laval, Québec, QC, Canada.,Départment de Médecine Moléculaire, Faculté de Médecine, Université Laval, Québec, QC, Canada.,Division of Medical Sciences, Medical Sciences Building, University of Victoria, Victoria, BC, Canada
| | - Micaël Carrier
- Axe Neurosciences, Centre de Recherche du CHU de Québec-Université Laval, Québec, QC, Canada.,Division of Medical Sciences, Medical Sciences Building, University of Victoria, Victoria, BC, Canada
| | - Fernando González Ibáñez
- Axe Neurosciences, Centre de Recherche du CHU de Québec-Université Laval, Québec, QC, Canada.,Départment de Médecine Moléculaire, Faculté de Médecine, Université Laval, Québec, QC, Canada.,Division of Medical Sciences, Medical Sciences Building, University of Victoria, Victoria, BC, Canada
| | - Mohammadparsa Khakpour
- Division of Medical Sciences, Medical Sciences Building, University of Victoria, Victoria, BC, Canada
| | - Marie-Josée Wallman
- Département de Psychiatrie et de Neurosciences, Faculté de Médecine, Université Laval, Québec, QC, Canada.,CERVO Brain Research Center, Quebec City, QC, Canada
| | - Martin Parent
- Département de Psychiatrie et de Neurosciences, Faculté de Médecine, Université Laval, Québec, QC, Canada.,CERVO Brain Research Center, Quebec City, QC, Canada
| | - Marie-Ève Tremblay
- Axe Neurosciences, Centre de Recherche du CHU de Québec-Université Laval, Québec, QC, Canada. .,Départment de Médecine Moléculaire, Faculté de Médecine, Université Laval, Québec, QC, Canada. .,Division of Medical Sciences, Medical Sciences Building, University of Victoria, Victoria, BC, Canada. .,Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, BC, Canada. .,Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada. .,Centre for Advanced Materials and Related Technology (CAMTEC), University of Victoria, Victoria, BC, Canada. .,Institute on Aging and Lifelong Health, University of Victoria, Victoria, BC, Canada.
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5
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St-Pierre MK, Šimončičová E, Carrier M, Tremblay MÈ. Microglia in Human Postmortem Brain Samples: Quantitative Ultrastructural Analysis of Scanning Electron Microscopy Images. Methods Mol Biol 2023; 2561:63-85. [PMID: 36399265 DOI: 10.1007/978-1-0716-2655-9_4] [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: 06/16/2023]
Abstract
In this protocol, we describe the specific steps required to prepare human postmortem brain samples for ultrastructural microglial analysis. A detailed procedure is provided to improve the ultrastructural quality of the samples, using aldehyde fixatives followed by immunoperoxidase staining of allograft inflammatory factor 1 (AIF1, also known as IBA1), a marker of myeloid cells, and cluster of differentiation 68 (CD68), a marker of phagolysosomal activity. Additionally, we describe an osmium-thiocarbohydrazide-osmium (OTO) post-fixation method that preserves and increases the contrast of cellular membranes in human postmortem brain samples, as well as the steps necessary to acquire scanning electron microscopy (SEM) images of microglial cell bodies. In the last section, we cover the quantitative analysis of various microglial cytoplasmic organelles and their interactions with other parenchymal elements.
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Affiliation(s)
- Marie-Kim St-Pierre
- Axe neurosciences, Centre de recherche du CHU de Québec-Université Laval, Québec, QC, Canada
- Département de médecine moléculaire, Faculté de médecine, Université Laval, Québec, QC, Canada
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
| | - Eva Šimončičová
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
- Neuroscience Graduate Program, University of Victoria, Victoria, Canada
| | - Micaël Carrier
- Axe neurosciences, Centre de recherche du CHU de Québec-Université Laval, Québec, QC, Canada
- Département de médecine moléculaire, Faculté de médecine, Université Laval, Québec, QC, Canada
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
| | - Marie-Ève Tremblay
- Axe neurosciences, Centre de recherche du CHU de Québec-Université Laval, Québec, QC, Canada.
- Département de médecine moléculaire, Faculté de médecine, Université Laval, Québec, QC, Canada.
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada.
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, BC, Canada.
- Department of Neurology and Neurosurgery, McGill University, Montréal, QC, Canada.
- Centre for Advanced Materials and Related Technology (CAMTEC), University of Victoria, Victoria, Canada.
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6
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Wang C, Zong S, Cui X, Wang X, Wu S, Wang L, Liu Y, Lu Z. The effects of microglia-associated neuroinflammation on Alzheimer's disease. Front Immunol 2023; 14:1117172. [PMID: 36911732 PMCID: PMC9992739 DOI: 10.3389/fimmu.2023.1117172] [Citation(s) in RCA: 35] [Impact Index Per Article: 35.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Accepted: 02/10/2023] [Indexed: 02/24/2023] Open
Abstract
Alzheimer's disease (AD) is defined as a severe chronic degenerative neurological disease in human. The pathogenic mechanism of AD has been convincingly elucidated by the "amyloid cascade hypothesis" with the main focus of the pathological accretion of β-amyloid (Aβ) peptides outside the cell. However, increasing evidence suggests that this hypothesis is weak in explaining the pathogenesis of AD. Neuroinflammation is crucial in the development of AD, which is proven by the elevated levels of inflammatory markers and the identification of AD risk genes relevant to the innate immune function. Here, we summarize the effects of microglia-mediated neuroinflammation on AD, focusing on the temporal and spatial changes in microglial phenotype, the interactions among microglia, Aβ, tau, and neurons, and the prospects and recent advances in neuroinflammation as a diagnostic and therapeutic target of AD.
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Affiliation(s)
- Cuicui Wang
- Department of Clinical Laboratory Medicine, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong, China
| | - Shuai Zong
- Department of Clinical Laboratory Medicine, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong, China
| | - Xiaolin Cui
- School of Medicine, Shandong University, Jinan, Shandong, China
| | - Xueying Wang
- Department of Clinical Laboratory Medicine, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong, China
| | - Shuang Wu
- School of Medicine, Shandong University, Jinan, Shandong, China
| | - Le Wang
- Department of Clinical Laboratory Medicine, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong, China
| | - Yingchao Liu
- Department of Clinical Laboratory Medicine, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong, China
| | - Zhiming Lu
- Department of Clinical Laboratory Medicine, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong, China
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7
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De Felice E, Gonçalves de Andrade E, Golia MT, González Ibáñez F, Khakpour M, Di Castro MA, Garofalo S, Di Pietro E, Benatti C, Brunello N, Tascedda F, Kaminska B, Limatola C, Ragozzino D, Tremblay ME, Alboni S, Maggi L. Microglial diversity along the hippocampal longitudinal axis impacts synaptic plasticity in adult male mice under homeostatic conditions. J Neuroinflammation 2022; 19:292. [PMID: 36482444 PMCID: PMC9730634 DOI: 10.1186/s12974-022-02655-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Accepted: 11/22/2022] [Indexed: 12/13/2022] Open
Abstract
The hippocampus is a plastic brain area that shows functional segregation along its longitudinal axis, reflected by a higher level of long-term potentiation (LTP) in the CA1 region of the dorsal hippocampus (DH) compared to the ventral hippocampus (VH), but the mechanisms underlying this difference remain elusive. Numerous studies have highlighted the importance of microglia-neuronal communication in modulating synaptic transmission and hippocampal plasticity, although its role in physiological contexts is still largely unknown. We characterized in depth the features of microglia in the two hippocampal poles and investigated their contribution to CA1 plasticity under physiological conditions. We unveiled the influence of microglia in differentially modulating the amplitude of LTP in the DH and VH, showing that minocycline or PLX5622 treatment reduced LTP amplitude in the DH, while increasing it in the VH. This was recapitulated in Cx3cr1 knockout mice, indicating that microglia have a key role in setting the conditions for plasticity processes in a region-specific manner, and that the CX3CL1-CX3CR1 pathway is a key element in determining the basal level of CA1 LTP in the two regions. The observed LTP differences at the two poles were associated with transcriptional changes in the expression of genes encoding for Il-1, Tnf-α, Il-6, and Bdnf, essential players of neuronal plasticity. Furthermore, microglia in the CA1 SR region showed an increase in soma and a more extensive arborization, an increased prevalence of immature lysosomes accompanied by an elevation in mRNA expression of phagocytic markers Mertk and Cd68 and a surge in the expression of microglial outward K+ currents in the VH compared to DH, suggesting a distinct basal phenotypic state of microglia across the two hippocampal poles. Overall, we characterized the molecular, morphological, ultrastructural, and functional profile of microglia at the two poles, suggesting that modifications in hippocampal subregions related to different microglial statuses can contribute to dissect the phenotypical aspects of many diseases in which microglia are known to be involved.
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Affiliation(s)
- E. De Felice
- grid.7841.aDepartment of Physiology and Pharmacology, Sapienza University of Rome, Piazzale Aldo Moro, 5, 00185 Rome, Italy
| | - E. Gonçalves de Andrade
- grid.143640.40000 0004 1936 9465Division of Medical Sciences, University of Victoria, Victoria, Canada
| | - M. T. Golia
- grid.7841.aDepartment of Physiology and Pharmacology, Sapienza University of Rome, Piazzale Aldo Moro, 5, 00185 Rome, Italy
| | - F. González Ibáñez
- grid.143640.40000 0004 1936 9465Division of Medical Sciences, University of Victoria, Victoria, Canada ,grid.411081.d0000 0000 9471 1794Faculté de Médecine and Centre de Recherche, CHU de Québec-Université Laval, Quebec, Canada
| | - M. Khakpour
- grid.143640.40000 0004 1936 9465Division of Medical Sciences, University of Victoria, Victoria, Canada
| | - M. A. Di Castro
- grid.7841.aDepartment of Physiology and Pharmacology, Sapienza University of Rome, Piazzale Aldo Moro, 5, 00185 Rome, Italy
| | - S. Garofalo
- grid.7841.aDepartment of Physiology and Pharmacology, Sapienza University of Rome, Piazzale Aldo Moro, 5, 00185 Rome, Italy
| | - E. Di Pietro
- grid.7841.aDepartment of Physiology and Pharmacology, Sapienza University of Rome, Piazzale Aldo Moro, 5, 00185 Rome, Italy
| | - C. Benatti
- grid.7548.e0000000121697570Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy ,grid.7548.e0000000121697570Centre of Neuroscience and Neurotechnology, University of Modena and Reggio Emilia, Modena, Italy
| | - N. Brunello
- grid.7548.e0000000121697570Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - F. Tascedda
- grid.7548.e0000000121697570Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy ,grid.7548.e0000000121697570Centre of Neuroscience and Neurotechnology, University of Modena and Reggio Emilia, Modena, Italy
| | - B. Kaminska
- grid.419305.a0000 0001 1943 2944Laboratory of Molecular Neurobiology, Nencki Institute of Experimental Biology of the Polish Academy of Sciences, Warsaw, Poland
| | - C. Limatola
- grid.419543.e0000 0004 1760 3561IRCCS Neuromed, Pozzilli, Italy ,grid.7841.aDepartment of Physiology and Pharmacology, Laboratory Affiliated to Istituto Pasteur, Sapienza University, Rome, Italy
| | - D. Ragozzino
- grid.7841.aDepartment of Physiology and Pharmacology, Sapienza University of Rome, Piazzale Aldo Moro, 5, 00185 Rome, Italy ,grid.417778.a0000 0001 0692 3437Santa Lucia Foundation (IRCCS Fondazione Santa Lucia), Rome, Italy
| | - M. E. Tremblay
- grid.143640.40000 0004 1936 9465Division of Medical Sciences, University of Victoria, Victoria, Canada ,grid.411081.d0000 0000 9471 1794Faculté de Médecine and Centre de Recherche, CHU de Québec-Université Laval, Quebec, Canada
| | - S. Alboni
- grid.7548.e0000000121697570Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy ,grid.7548.e0000000121697570Centre of Neuroscience and Neurotechnology, University of Modena and Reggio Emilia, Modena, Italy
| | - L. Maggi
- grid.7841.aDepartment of Physiology and Pharmacology, Sapienza University of Rome, Piazzale Aldo Moro, 5, 00185 Rome, Italy
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8
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St-Pierre MK, Carrier M, González Ibáñez F, Šimončičová E, Wallman MJ, Vallières L, Parent M, Tremblay MÈ. Ultrastructural characterization of dark microglia during aging in a mouse model of Alzheimer's disease pathology and in human post-mortem brain samples. J Neuroinflammation 2022; 19:235. [PMID: 36167544 PMCID: PMC9513936 DOI: 10.1186/s12974-022-02595-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2022] [Accepted: 09/12/2022] [Indexed: 11/10/2022] Open
Abstract
A diverse heterogeneity of microglial cells was previously described in Alzheimer's disease (AD) pathology, including dark microglia, a state characterized by ultrastructural markers of cellular stress. To provide novel insights into the roles of dark microglia during aging in the context of AD pathology, we performed a quantitative density and ultrastructural analysis of these cells using high-throughput scanning electron microscopy in the ventral hippocampus CA1 stratum lacunosum-moleculare of 20-month-old APP-PS1 vs C57BL/6J male mice. The density of dark microglia was significantly higher in APP-PS1 vs C57BL/6J mice, with these cells accounting for nearly half of all microglia observed near amyloid-beta (Aβ) plaques. This dark microglial state interacted more with dystrophic neurites compared to other APP-PS1 microglia and possessed glycogen granules, associated with a metabolic shift toward glycolysis, which provides the first ultrastructural evidence of their presence in microglia. Dark microglia were further observed in aging human post-mortem brain samples showing similar ultrastructural features as in mouse. Overall, our results provide a quantitative ultrastructural characterization of a microglial state associated with cellular stress (i.e., dark microglia) that is primarily restricted near Aβ plaques and dystrophic neurites. The presence of this microglial state in the aging human post-mortem brain is further revealed.
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Affiliation(s)
- Marie-Kim St-Pierre
- Axe Neurosciences, Centre de Recherche du CHU de Québec-Université Laval, Québec, QC, Canada.,Department of Molecular Medicine, Université Laval, Québec City, QC, Canada.,Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
| | - Micaël Carrier
- Axe Neurosciences, Centre de Recherche du CHU de Québec-Université Laval, Québec, QC, Canada.,Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
| | - Fernando González Ibáñez
- Department of Molecular Medicine, Université Laval, Québec City, QC, Canada.,Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
| | - Eva Šimončičová
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada.,Neuroscience Graduate Program, University of Victoria, Victoria, BC, Canada
| | - Marie-Josée Wallman
- Département de Psychiatrie et de Neurosciences, Faculté de Médecine, Université Laval, Quebec, QC, Canada.,CERVO Brain Research Center, Quebec, QC, Canada
| | - Luc Vallières
- Axe Neurosciences, Centre de Recherche du CHU de Québec-Université Laval, Québec, QC, Canada.,Department of Molecular Medicine, Université Laval, Québec City, QC, Canada
| | - Martin Parent
- Département de Psychiatrie et de Neurosciences, Faculté de Médecine, Université Laval, Quebec, QC, Canada.,CERVO Brain Research Center, Quebec, QC, Canada
| | - Marie-Ève Tremblay
- Axe Neurosciences, Centre de Recherche du CHU de Québec-Université Laval, Québec, QC, Canada. .,Department of Molecular Medicine, 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. .,Department of Neurology and Neurosurgery, McGill University, Montréal, QC, Canada. .,Centre for Advanced Materials and Related Technology (CAMTEC), University of Victoria, Victoria, BC, Canada.
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9
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St-Pierre MK, VanderZwaag J, Loewen S, Tremblay MÈ. All roads lead to heterogeneity: The complex involvement of astrocytes and microglia in the pathogenesis of Alzheimer’s disease. Front Cell Neurosci 2022; 16:932572. [PMID: 36035256 PMCID: PMC9413962 DOI: 10.3389/fncel.2022.932572] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Accepted: 07/11/2022] [Indexed: 01/04/2023] Open
Abstract
In recent years, glial cells have been acknowledged as key players in the pathogenesis of Alzheimer’s disease (AD), a neurodegenerative condition in which an accumulation of intracellular neurofibrillary tangles and extracellular fibrillar amyloid beta is notably observed in the central nervous system. Genome-wide association studies have shown, both in microglia and astrocytes, an increase in gene variants associated with a higher risk of developing late-onset AD. Microglia, the resident innate immune cells of the brain, and astrocytes, glial cells crucial for vascular integrity and neuronal support, both agglomerate near amyloid beta plaques and dystrophic neurites where they participate in the elimination of these harmful parenchymal elements. However, their role in AD pathogenesis has been challenging to resolve due to the highly heterogeneous nature of these cell populations, i.e., their molecular, morphological, and ultrastructural diversity, together with their ever-changing responsiveness and functions throughout the pathological course of AD. With the recent expansions in the field of glial heterogeneity through innovative advances in state-of-the-art microscopy and -omics techniques, novel concepts and questions arose, notably pertaining to how the diverse microglial and astrocytic states interact with each other and with the AD hallmarks, and how their concerted efforts/actions impact the progression of the disease. In this review, we discuss the recent advances and findings on the topic of glial heterogeneity, particularly focusing on the relationships of these cells with AD hallmarks (e.g., amyloid beta plaques, neurofibrillary tangles, synaptic loss, and dystrophic neurites) in murine models of AD pathology and post-mortem brain samples of patients with AD.
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Affiliation(s)
- Marie-Kim St-Pierre
- Département de Médecine Moléculaire, Université Laval, Quebec City, QC, Canada
- Axe Neurosciences, Center de Recherche du CHU de Québec, Université Laval, Quebec City, QC, Canada
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
| | - Jared VanderZwaag
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
- Neuroscience Graduate Program, University of Victoria, Victoria, BC, Canada
| | - Sophia Loewen
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
- Department of Biology, University of Victoria, Victoria, BC, Canada
| | - Marie-Ève Tremblay
- Département de Médecine Moléculaire, Université Laval, Quebec City, QC, Canada
- Axe Neurosciences, Center de Recherche du CHU de Québec, Université Laval, Quebec City, QC, Canada
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
- Neurology and Neurosurgery Department, McGill University, Montréal, QC, Canada
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, BC, Canada
- Center for Advanced Materials and Related Technology (CAMTEC), University of Victoria, Victoria, BC, Canada
- *Correspondence: Marie-Ève Tremblay,
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10
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St-Pierre MK, Carrier M, Lau V, Tremblay MÈ. Investigating Microglial Ultrastructural Alterations and Intimate Relationships with Neuronal Stress, Dystrophy, and Degeneration in Mouse Models of Alzheimer's Disease. METHODS IN MOLECULAR BIOLOGY (CLIFTON, N.J.) 2022; 2515:29-58. [PMID: 35776344 DOI: 10.1007/978-1-0716-2409-8_3] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
In recent decades, microglia have taken the field of neuroscience by storm, with numerous studies identifying key roles for these cells in the pathophysiology of neurodegenerative conditions, such as Alzheimer's disease (AD). The heterogeneity of these cells (e.g., the presence of various subtypes like the disease-associated microglia, microglia associated with neurodegeneration, dark microglia, lipid droplet-accumulating microglia), and their ultrastructural alterations arising from environmental challenges have become a central focus of recent studies. Dark microglia are electron-dense cells defined by their ultrastructural markers of cellular stress using electron microscopy (EM). In this protocol, we first describe the steps required for proper brain tissue preparation for EM experiments. Ultrastructural analysis of microglia and neurons/synapses in AD mouse models is also detailed, using transmission or scanning EM. We next explain how to characterize several ultrastructural markers of cellular stress, dystrophy or degeneration, in microglia and neurons/synapses, with relation to amyloid beta plaques.
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Affiliation(s)
- Marie-Kim St-Pierre
- Axe neurosciences, Centre de recherche du CHU de Québec-Université Laval, Québec, QC, Canada.,Département de médecine moléculaire, Faculté de médecine, Université Laval, Québec, QC, Canada.,Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
| | - Micaël Carrier
- Axe neurosciences, Centre de recherche du CHU de Québec-Université Laval, Québec, QC, Canada.,Division of Medical Sciences, University of Victoria, Victoria, BC, Canada.,Département de neurosciences, Faculté de médecine, Université Laval, Québec, QC, Canada
| | - Victor Lau
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada.,Department of Biomedical Physiology & Kinesiology, Simon Fraser University, Victoria, BC, Canada
| | - Marie-Ève Tremblay
- Axe neurosciences, Centre de recherche du CHU de Québec-Université Laval, Québec, QC, Canada. .,Département de médecine moléculaire, Faculté de médecine, Université Laval, Québec, QC, Canada. .,Division of Medical Sciences, University of Victoria, Victoria, BC, Canada. .,The Department of Biochemistry and Molecular Biology, The University of British Columbia, Vancouver, BC, Canada. .,Department of Neurology and Neurosurgery, McGill University, Montréal, QC, Canada. .,Centre for Advanced Materials and Related Technology (CAMTEC), University of Victoria , Victoria, Canada.
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11
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Uyar O, Dominguez JM, Bordeleau M, Lapeyre L, Ibáñez FG, Vallières L, Tremblay ME, Corbeil J, Boivin G. Single-cell transcriptomics of the ventral posterolateral nucleus-enriched thalamic regions from HSV-1-infected mice reveal a novel microglia/microglia-like transcriptional response. J Neuroinflammation 2022; 19:81. [PMID: 35387656 PMCID: PMC8985399 DOI: 10.1186/s12974-022-02437-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Accepted: 03/13/2022] [Indexed: 12/17/2022] Open
Abstract
Background Microglia participate in the immune response upon central nervous system (CNS) infections. However, the role of these cells during herpes simplex encephalitis (HSE) has not been fully characterized. We sought to identify different microglia/microglia-like cells and describe the potential mechanisms and signaling pathways involved during HSE. Methods The transcriptional response of CD11b+ immune cells, including microglia/microglia-like cells, was investigated using single-cell RNA sequencing (scRNA-seq) on cells isolated from the ventral posterolateral nucleus (VPL)-enriched thalamic regions of C57BL/6 N mice intranasally infected with herpes simplex virus-1 (HSV-1) (6 × 105 PFUs/20 µl). We further performed scanning electronic microscopy (SEM) analysis in VPL regions on day 6 post-infection (p.i.) to provide insight into microglial functions. Results We describe a novel microglia-like transcriptional response associated with a rare cell population (7% of all analyzed cells), named “in transition” microglia/microglia-like cells in HSE. This new microglia-like transcriptional signature, found in the highly infected thalamic regions, was enriched in specific genes (Retnlg, Cxcr2, Il1f9) usually associated with neutrophils. Pathway analysis of this cell-type transcriptome showed increased NLRP3-inflammasome-mediated interleukin IL-1β production, promoting a pro-inflammatory response. These cells' increased expression of viral transcripts suggests that the distinct “in transition” transcriptome corresponds to the intrinsic antiviral immune signaling of HSV-1-infected microglia/microglia-like cells in the thalamus. In accordance with this phenotype, we observed several TMEM119+/IBA-I+ microglia/microglia-like cells immunostained for HSV-1 in highly infected regions. Conclusions A new microglia/microglia-like state may potentially shed light on how microglia could react to HSV-1 infection. Our observations suggest that infected microglia/microglia-like cells contribute to an exacerbated CNS inflammation. Further characterization of this transitory state of the microglia/microglia-like cell transcriptome may allow the development of novel immunomodulatory approaches to improve HSE outcomes by regulating the microglial immune response. Supplementary Information The online version contains supplementary material available at 10.1186/s12974-022-02437-7.
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Affiliation(s)
- Olus Uyar
- Research Center in Infectious Diseases, CHU de Québec-Laval University Research Center and Department of Pediatrics and Microbiology, Faculty of Medicine, Laval University, Quebec City, QC, Canada
| | - Juan Manuel Dominguez
- Research Center in Infectious Diseases, CHU de Québec-Laval University Research Center and Department of Molecular Medicine and Big Data Research Centre, Faculty of Medicine, Laval University, Quebec City, QC, Canada
| | - Maude Bordeleau
- Integrated Program in Neuroscience, McGill University, Montreal, QC, Canada.,Neurosciences Unit, CHU de Québec-Laval University Research Center, Quebec City, QC, Canada
| | - Lina Lapeyre
- Research Center in Infectious Diseases, CHU de Québec-Laval University Research Center and Department of Pediatrics and Microbiology, Faculty of Medicine, Laval University, Quebec City, QC, Canada
| | - Fernando González Ibáñez
- Neurosciences Unit, CHU de Québec-Laval University Research Center, Quebec City, QC, Canada.,Department of Molecular Medicine, Laval University, Quebec City, QC, Canada.,Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
| | - Luc Vallières
- Neurosciences Unit, CHU de Québec-Laval University Research Center, Quebec City, QC, Canada.,Department of Molecular Medicine, Laval University, Quebec City, QC, Canada
| | - Marie-Eve Tremblay
- Neurosciences Unit, CHU de Québec-Laval University Research Center, Quebec City, QC, Canada.,Department of Molecular Medicine, Laval University, Quebec City, QC, Canada.,Division of Medical Sciences, University of Victoria, Victoria, BC, Canada.,Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada.,Department of Biochemistry and Molecular Biology, The University of British Columbia, Vancouver, BC, Canada.,Centre for Advanced Materials and Related Technology (CAMTEC), University of Victoria, Victoria, BC, Canada
| | - Jacques Corbeil
- Research Center in Infectious Diseases, CHU de Québec-Laval University Research Center and Department of Molecular Medicine and Big Data Research Centre, Faculty of Medicine, Laval University, Quebec City, QC, Canada.,Department of Molecular Medicine, Laval University, Quebec City, QC, Canada
| | - Guy Boivin
- Research Center in Infectious Diseases, CHU de Québec-Laval University Research Center and Department of Pediatrics and Microbiology, Faculty of Medicine, Laval University, Quebec City, QC, Canada.
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12
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Decoeur F, Picard K, St-Pierre MK, Greenhalgh AD, Delpech JC, Sere A, Layé S, Tremblay ME, Nadjar A. N-3 PUFA Deficiency Affects the Ultrastructural Organization and Density of White Matter Microglia in the Developing Brain of Male Mice. Front Cell Neurosci 2022; 16:802411. [PMID: 35221920 PMCID: PMC8866569 DOI: 10.3389/fncel.2022.802411] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Accepted: 01/17/2022] [Indexed: 02/03/2023] Open
Abstract
Over the last century, westernization of dietary habits has led to a dramatic reduction in dietary intake of n-3 polyunsaturated fatty acids (n-3 PUFAs). In particular, low maternal intake of n-3 PUFAs throughout gestation and lactation causes defects in brain myelination. Microglia are recognized for their critical contribution to neurodevelopmental processes, such as myelination. These cells invade the white matter in the first weeks of the post-natal period, where they participate in oligodendrocyte maturation and myelin production. Therefore, we investigated whether an alteration of white matter microglia accompanies the myelination deficits observed in the brain of n-3 PUFA-deficient animals. Macroscopic imaging analysis shows that maternal n-3 PUFA deficiency decreases the density of white matter microglia around post-natal day 10. Microscopic electron microscopy analyses also revealed alterations of microglial ultrastructure, a decrease in the number of contacts between microglia and myelin sheet, and a decreased amount of myelin debris in their cell body. White matter microglia further displayed increased mitochondrial abundance and network area under perinatal n-3 PUFA deficiency. Overall, our data suggest that maternal n-3 PUFA deficiency alters the structure and function of microglial cells located in the white matter of pups early in life, and this could be the key to understand myelination deficits during neurodevelopment.
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Affiliation(s)
- Fanny Decoeur
- INRAE, Bordeaux INP, NutriNeuro, Université de Bordeaux, Bordeaux, France
| | - Katherine Picard
- Axe Neurosciences, Centre de Recherche du CHU de Québec–Université Laval, Québec, QC, Canada
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
- Département de Médecine Moléculaire, Université Laval, Québec, QC, Canada
| | - Marie-Kim St-Pierre
- Axe Neurosciences, Centre de Recherche du CHU de Québec–Université Laval, Québec, QC, Canada
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
- Département de Médecine Moléculaire, Université Laval, Québec, QC, Canada
| | | | | | - Alexandra Sere
- INRAE, Bordeaux INP, NutriNeuro, Université de Bordeaux, Bordeaux, France
| | - Sophie Layé
- INRAE, Bordeaux INP, NutriNeuro, Université de Bordeaux, Bordeaux, France
| | - Marie-Eve Tremblay
- Axe Neurosciences, Centre de Recherche du CHU de Québec–Université Laval, Québec, QC, Canada
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
- Département de Médecine Moléculaire, Université Laval, Québec, QC, Canada
- Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada
- Department of Biochemistry and Molecular Biology, The University of British Columbia, Vancouver, BC, Canada
| | - Agnès Nadjar
- INRAE, Bordeaux INP, NutriNeuro, Université de Bordeaux, Bordeaux, France
- Neurocentre Magendie, U1215, INSERM-Université de Bordeaux, Bordeaux, France
- Institut Universitaire de France (IUF), Paris, France
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13
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Maternal high-fat diet in mice induces cerebrovascular, microglial and long-term behavioural alterations in offspring. Commun Biol 2022; 5:26. [PMID: 35017640 PMCID: PMC8752761 DOI: 10.1038/s42003-021-02947-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Various environmental exposures during pregnancy, like maternal diet, can compromise, at critical periods of development, the neurovascular maturation of the offspring. Foetal exposure to maternal high-fat diet (mHFD), common to Western societies, has been shown to disturb neurovascular development in neonates and long-term permeability of the neurovasculature. Nevertheless, the effects of mHFD on the offspring’s cerebrovascular health remains largely elusive. Here, we sought to address this knowledge gap by using a translational mouse model of mHFD exposure. Three-dimensional and ultrastructure analysis of the neurovascular unit (vasculature and parenchymal cells) in mHFD-exposed offspring revealed major alterations of the neurovascular organization and metabolism. These alterations were accompanied by changes in the expression of genes involved in metabolism and immunity, indicating that neurovascular changes may result from abnormal brain metabolism and immune regulation. In addition, mHFD-exposed offspring showed persisting behavioural alterations reminiscent of neurodevelopmental disorders, specifically an increase in stereotyped and repetitive behaviours into adulthood. In order to advance our understanding of the effects of maternal high-fat diet (mHFD) on the cerebrovascular health of offspring, Bordeleau et al. use a translational mouse model of mHFD exposure. They demonstrate that mHFD induces cerebrovascular and microglial changes in the offspring as well as behavioural alterations that are reminiscent of neurodevelopmental disorders associated with repetitive behaviours at adulthood.
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14
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Bordeleau M, Fernández de Cossío L, Lacabanne C, Savage JC, Vernoux N, Chakravarty M, Tremblay MÈ. Maternal high-fat diet modifies myelin organization, microglial interactions, and results in social memory and sensorimotor gating deficits in adolescent mouse offspring. Brain Behav Immun Health 2021; 15:100281. [PMID: 34589781 PMCID: PMC8474164 DOI: 10.1016/j.bbih.2021.100281] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Accepted: 06/04/2021] [Indexed: 12/29/2022] Open
Abstract
Prenatal exposure to maternal high-fat diet (mHFD) acts as a risk factor for various neurodevelopmental alterations in the progeny. Recent studies in mice revealed that mHFD results in both neuroinflammation and hypomyelination in the exposed offspring. Microglia, the brain-resident macrophages, play crucial roles during brain development, notably by modulating oligodendrocyte populations and performing phagocytosis of myelin sheaths. Previously, we reported that mHFD modifies microglial phenotype (i.e., morphology, interactions with their microenvironment, transcripts) in the hippocampus of male and female offspring. In the current study, we further explored whether mHFD may induce myelination changes among the hippocampal-corpus callosum-prefrontal cortex pathway, and result in behavioral outcomes in adolescent offspring of the two sexes. To this end, female mice were fed with control chow or HFD for 4 weeks before mating, during gestation, and until weaning of their litter. Histological and ultrastructural analyses revealed an increased density of myelin associated with a reduced area of cytosolic myelin channels in the corpus callosum of mHFD-exposed male compared to female offspring. Transcripts of myelination-associated genes including Igf1 -a growth factor released by microglia- were also lower, specifically in the hippocampus (without changes in the prefrontal cortex) of adolescent male mouse offspring. These changes in myelin were not related to an altered density, distribution, or maturation of oligodendrocytes, instead we found that microglia within the corpus callosum of mHFD-exposed offspring showed reduced numbers of mature lysosomes and increased synaptic contacts, suggesting microglial implication in the modified myelination. At the behavioral level, both male and female mHFD-exposed adolescent offspring presented loss of social memory and sensorimotor gating deficits. These results together highlight the importance of studying oligodendrocyte-microglia crosstalk and its involvement in the long-term brain alterations that result from prenatal mHFD in offspring across sexes.
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Affiliation(s)
- Maude Bordeleau
- Integrated Program in Neuroscience, McGill University, Montréal, QC, Canada.,Axe Neurosciences, Centre de Recherche du CHU de Québec - Université Laval, Québec, QC, Canada
| | | | - Chloé Lacabanne
- Integrated Program in Neuroscience, McGill University, Montréal, QC, Canada
| | - Julie C Savage
- Axe Neurosciences, Centre de Recherche du CHU de Québec - Université Laval, Québec, QC, Canada
| | - Nathalie Vernoux
- Axe Neurosciences, Centre de Recherche du CHU de Québec - Université Laval, Québec, QC, Canada
| | - Mallar Chakravarty
- Integrated Program in Neuroscience, McGill University, Montréal, QC, Canada.,Cerebral Imaging Center, Douglas Mental Health University Institute, McGill University, Montréal, QC, Canada.,Department of Psychiatry, McGill University, Montréal, QC, Canada.,Department of Biological and Biomedical Engineering, McGill University, Montréal, QC, Canada
| | - Marie-Ève Tremblay
- Axe Neurosciences, Centre de Recherche du CHU de Québec - Université Laval, Québec, QC, Canada.,Département de Médecine Moléculaire, Université Laval, Québec, QC, Canada.,Department of Neurology and Neurosurgery, McGill University, Montréal, QC, Canada.,Division of Medical Sciences, University of Victoria, Victoria, BC, Canada.,Department of Biochemistry and Molecular Biology, Faculty of Medicine, The University of British Colombia, Vancouver, BC, Canada
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15
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Augusto-Oliveira M, Arrifano GP, Delage CI, Tremblay MÈ, Crespo-Lopez ME, Verkhratsky A. Plasticity of microglia. Biol Rev Camb Philos Soc 2021; 97:217-250. [PMID: 34549510 DOI: 10.1111/brv.12797] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 09/02/2021] [Accepted: 09/06/2021] [Indexed: 02/06/2023]
Abstract
Microglial cells are the scions of foetal macrophages which invade the neural tube early during embryogenesis. The nervous tissue environment instigates the phenotypic metamorphosis of foetal macrophages into idiosyncratic surveilling microglia, which are generally characterised by a small cell body and highly ramified motile processes that constantly scan the nervous tissue for signs of changes in homeostasis and allow microglia to perform crucial homeostatic functions. The surveilling microglial phenotype is evolutionarily conserved from early invertebrates to humans. Despite this evolutionary conservation, microglia show substantial heterogeneity in their gene and protein expression, as well as morphological appearance. These differences are age, region and context specific and reflect a high degree of plasticity underlying the life-long adaptation of microglia, supporting the exceptional adaptive capacity of the central nervous system. Microgliocytes are essential elements of cellular network formation and refinement in the developing nervous tissue. Several distinct patrolling modes of microglial processes contribute to the formation, modification, and pruning of synapses; to the support and protection of neurones through microglial-somatic junctions; and to the control of neuronal and axonal excitability by specific microglia-axonal contacts. In pathology, microglia undergo proliferation and reactive remodelling known as microgliosis, which is context dependent, yet represents an evolutionarily conserved defence response. Microgliosis results in the emergence of multiple disease and context-specific reactive states; in addition, neuropathology is associated with the appearance of specific protective or recovery microglial forms. In summary, the plasticity of microglia supports the development and functional activity of healthy nervous tissue and provides highly sophisticated defences against disease.
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Affiliation(s)
- Marcus Augusto-Oliveira
- Laboratório de Farmacologia Molecular, Instituto de Ciências Biológicas, Universidade Federal do Pará, 66075-110, Belém, Brazil
| | - Gabriela P Arrifano
- Laboratório de Farmacologia Molecular, Instituto de Ciências Biológicas, Universidade Federal do Pará, 66075-110, Belém, Brazil
| | - Charlotte Isabelle Delage
- Division of Medical Sciences, Medical Sciences Building, University of Victoria, Victoria, BC, V8P 5C2, Canada
| | - Marie-Ève Tremblay
- Division of Medical Sciences, Medical Sciences Building, University of Victoria, Victoria, BC, V8P 5C2, Canada.,Axe Neurosciences, Centre de Recherche du CHU de Québec-Université Laval, 2705 Boulevard Laurier, Québec City, QC, G1V 4G2, Canada.,Neurology and Neurosurgery Department, McGill University, 3801 University Street, Montreal, QC, H3A 2B4, Canada.,Department of Molecular Medicine, Université Laval, Pavillon Ferdinand-Vandry, Bureau 4835, 1050 Avenue de la Médecine, Québec City, QC, G1V 0A6, Canada.,Department of Biochemistry and Molecular Biology, The University of British Columbia, Life Sciences Center, 2350 Health Sciences Mall, Vancouver, BC, V6T 1Z3, Canada
| | - Maria Elena Crespo-Lopez
- Laboratório de Farmacologia Molecular, Instituto de Ciências Biológicas, Universidade Federal do Pará, 66075-110, Belém, Brazil
| | - Alexei Verkhratsky
- Faculty of Life Sciences, The University of Manchester, Oxford Road, Manchester, M13 9PT, U.K.,Achucarro Center for Neuroscience, IKERBASQUE, 48011, Bilbao, Spain.,Department of Stem Cell Biology, State Research Institute Centre for Innovative Medicine, LT-01102, Vilnius, Lithuania
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16
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St-Pierre MK, Šimončičová E, Bögi E, Tremblay MÈ. Shedding Light on the Dark Side of the Microglia. ASN Neuro 2021; 12:1759091420925335. [PMID: 32443939 PMCID: PMC7249604 DOI: 10.1177/1759091420925335] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Microglia, the resident immune cells of the central nervous system, are not a
homogeneous population; their morphology, molecular profile, and even their
ultrastructure greatly vary from one cell to another. Recent advances in the
field of neuroimmunology have helped to demystify the enigma that currently
surrounds microglial heterogeneity. Indeed, numerous microglial subtypes have
been discovered such as the disease-associated microglia, neurodegenerative
phenotype, and Cd11c-positive developmental population. Another subtype is the
dark microglia (DM), a population defined by its ultrastructural changes
associated with cellular stress. Since their first characterization using
transmission electron microscopy, they have been identified in numerous disease
conditions, from mouse models of Alzheimer’s disease, schizophrenia, fractalkine
signaling deficiency to chronic stress, just to name a few. A recent study also
identified the presence of cells with a similar ultrastructure to the DM in
postmortem brain samples from schizophrenic patients,
underlining the importance of understanding the function of these cells. In this
minireview, we aim to summarize the current knowledge on the DM, from their
initial ultrastructural characterization to their documentation in various
pathological contexts across multiple species. We will also highlight the
current limitations surrounding the study of these cells and the future that
awaits the DM.
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Affiliation(s)
| | - Eva Šimončičová
- Axe Neurosciences, Centre de Recherche du CHU de Québec-Université Laval.,Department of Pharmacology, Jessenius Faculty of Medicine, Comenius University, Martin, Slovak Republic.,Institute of Experimental Pharmacology and Toxicology, Centre of Experimental Medicine, Slovak Academy of Sciences, Bratislava, Slovak Republic
| | - Eszter Bögi
- Department of Pharmacology, Jessenius Faculty of Medicine, Comenius University, Martin, Slovak Republic
| | - Marie-Ève Tremblay
- Axe Neurosciences, Centre de Recherche du CHU de Québec-Université Laval
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17
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Enlow W, Bordeleau M, Piret J, Ibáñez FG, Uyar O, Venable MC, Goyette N, Carbonneau J, Tremblay ME, Boivin G. Microglia are involved in phagocytosis and extracellular digestion during Zika virus encephalitis in young adult immunodeficient mice. J Neuroinflammation 2021; 18:178. [PMID: 34399779 PMCID: PMC8369691 DOI: 10.1186/s12974-021-02221-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Accepted: 07/16/2021] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND Zika virus (ZIKV) has been associated with several neurological complications in adult patients. METHODS We used a mouse model deficient in TRIF and IPS-1 adaptor proteins, which are involved in type I interferon production, to study the role of microglia during brain infection by ZIKV. Young adult mice were infected intravenously with the contemporary ZIKV strain PRVABC59 (1 × 105 PFUs/100 µL). RESULTS Infected mice did not present overt clinical signs of the disease nor body weight loss compared with noninfected animals. However, mice exhibited a viremia and a brain viral load that were maximal (1.3 × 105 genome copies/mL and 9.8 × 107 genome copies/g of brain) on days 3 and 7 post-infection (p.i.), respectively. Immunohistochemistry analysis showed that ZIKV antigens were distributed in several regions of the brain, especially the dorsal hippocampus. The number of Iba1+/TMEM119+ microglia remained similar in infected versus noninfected mice, but their cell body and arborization areas significantly increased in the stratum radiatum and stratum lacunosum-moleculare layers of the dorsal hippocampus cornu ammoni (CA)1, indicating a reactive state. Ultrastructural analyses also revealed that microglia displayed increased phagocytic activities and extracellular digestion of degraded elements during infection. Mice pharmacologically depleted in microglia with PLX5622 presented a higher brain viral load compared to untreated group (2.8 × 1010 versus 8.5 × 108 genome copies/g of brain on day 10 p.i.) as well as an increased number of ZIKV antigens labeled with immunogold in the cytoplasm and endoplasmic reticulum of neurons and astrocytes indicating an enhanced viral replication. Furthermore, endosomes of astrocytes contained nanogold particles together with digested materials, suggesting a compensatory phagocytic activity upon microglial depletion. CONCLUSIONS These results indicate that microglia are involved in the control of ZIKV replication and/or its elimination in the brain. After depletion of microglia, the removal of ZIKV-infected cells by phagocytosis could be partly compensated by astrocytes.
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Affiliation(s)
- William Enlow
- Centre de Recherche en Infectiologie, Centre de Recherche du CHU de Québec-Université Laval, Quebec City, QC, Canada
| | - Maude Bordeleau
- Integrated Program in Neuroscience, McGill University, Montreal, QC, Canada.,Neurosciences Axis, Centre de recherche du CHU de Québec-Université Laval, Quebec City, QC, Canada
| | - Jocelyne Piret
- Centre de Recherche en Infectiologie, Centre de Recherche du CHU de Québec-Université Laval, Quebec City, QC, Canada
| | - Fernando González Ibáñez
- Neurosciences Axis, Centre de recherche du CHU de Québec-Université Laval, Quebec City, QC, Canada.,Department of Molecular Medicine, Université Laval, Quebec City, QC, Canada.,Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
| | - Olus Uyar
- Centre de Recherche en Infectiologie, Centre de Recherche du CHU de Québec-Université Laval, Quebec City, QC, Canada
| | - Marie-Christine Venable
- Centre de Recherche en Infectiologie, Centre de Recherche du CHU de Québec-Université Laval, Quebec City, QC, Canada
| | - Nathalie Goyette
- Centre de Recherche en Infectiologie, Centre de Recherche du CHU de Québec-Université Laval, Quebec City, QC, Canada
| | - Julie Carbonneau
- Centre de Recherche en Infectiologie, Centre de Recherche du CHU de Québec-Université Laval, Quebec City, QC, Canada
| | - Marie-Eve Tremblay
- Neurosciences Axis, Centre de recherche du CHU de Québec-Université Laval, Quebec City, QC, Canada. .,Department of Molecular Medicine, Université Laval, Quebec City, QC, Canada. .,Division of Medical Sciences, University of Victoria, Victoria, BC, Canada. .,Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada. .,Department of Biochemistry and Molecular Biology, The University of British Columbia, Vancouver, BC, Canada.
| | - Guy Boivin
- Centre de Recherche en Infectiologie, Centre de Recherche du CHU de Québec-Université Laval, Quebec City, QC, Canada.
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18
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Nahirney PC, Tremblay ME. Brain Ultrastructure: Putting the Pieces Together. Front Cell Dev Biol 2021; 9:629503. [PMID: 33681208 PMCID: PMC7930431 DOI: 10.3389/fcell.2021.629503] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2020] [Accepted: 01/20/2021] [Indexed: 12/11/2022] Open
Abstract
Unraveling the fine structure of the brain is important to provide a better understanding of its normal and abnormal functioning. Application of high-resolution electron microscopic techniques gives us an unprecedented opportunity to discern details of the brain parenchyma at nanoscale resolution, although identifying different cell types and their unique features in two-dimensional, or three-dimensional images, remains a challenge even to experts in the field. This article provides insights into how to identify the different cell types in the central nervous system, based on nuclear and cytoplasmic features, amongst other unique characteristics. From the basic distinction between neurons and their supporting cells, the glia, to differences in their subcellular compartments, organelles and their interactions, ultrastructural analyses can provide unique insights into the changes in brain function during aging and disease conditions, such as stroke, neurodegeneration, infection and trauma. Brain parenchyma is composed of a dense mixture of neuronal and glial cell bodies, together with their intertwined processes. Intracellular components that vary between cells, and can become altered with aging or disease, relate to the cytoplasmic and nucleoplasmic density, nuclear heterochromatin pattern, mitochondria, endoplasmic reticulum and Golgi complex, lysosomes, neurosecretory vesicles, and cytoskeletal elements (actin, intermediate filaments, and microtubules). Applying immunolabeling techniques to visualize membrane-bound or intracellular proteins in neurons and glial cells gives an even better appreciation of the subtle differences unique to these cells across contexts of health and disease. Together, our observations reveal how simple ultrastructural features can be used to identify specific changes in cell types, their health status, and functional relationships in the brain.
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19
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Picard K, St-Pierre MK, Vecchiarelli HA, Bordeleau M, Tremblay MÈ. Neuroendocrine, neuroinflammatory and pathological outcomes of chronic stress: A story of microglial remodeling. Neurochem Int 2021; 145:104987. [PMID: 33587954 DOI: 10.1016/j.neuint.2021.104987] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 02/07/2021] [Accepted: 02/08/2021] [Indexed: 02/07/2023]
Abstract
Microglia, the resident macrophage cells of the central nervous system (CNS), are involved in a myriad of processes required to maintain CNS homeostasis. These cells are dynamic and can adapt their phenotype and functions to the physiological needs of the organism. Microglia rapidly respond to changes occurring in their microenvironment, such as the ones taking place during stress. While stress can be beneficial for the organism to adapt to a situation, it can become highly detrimental when it turns chronic. Microglial response to prolonged stress may lead to an alteration of their beneficial physiological functions, becoming either maladaptive or pro-inflammatory. In this review, we aim to summarize the effects of chronic stress exerted on microglia through the neuroendocrine system and inflammation at adulthood. We also discuss how these effects of chronic stress could contribute to microglial involvement in neuropsychiatric and sleep disorders, as well as neurodegenerative diseases.
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Affiliation(s)
- Katherine Picard
- Axe Neurosciences, Centre de recherche du CHU de Québec-Université Laval, Québec, QC, Canada; Division of Medical Sciences, University of Victoria, Victoria, BC, Canada; Department of Molecular Medicine, Faculty of Medicine, Université Laval, Québec, QC, Canada
| | - Marie-Kim St-Pierre
- Axe Neurosciences, Centre de recherche du CHU de Québec-Université Laval, Québec, QC, Canada; Division of Medical Sciences, University of Victoria, Victoria, BC, Canada; Department of Molecular Medicine, Faculty of Medicine, Université Laval, Québec, QC, Canada
| | | | - Maude Bordeleau
- Axe Neurosciences, Centre de recherche du CHU de Québec-Université Laval, Québec, QC, Canada; Integrated Program in Neuroscience, McGill University, Montreal, QC, Canada
| | - Marie-Ève Tremblay
- Axe Neurosciences, Centre de recherche du CHU de Québec-Université Laval, Québec, QC, Canada; Division of Medical Sciences, University of Victoria, Victoria, BC, Canada; Department of Molecular Medicine, Faculty of Medicine, Université Laval, Québec, QC, Canada; Neurology and Neurosurgery Department, McGill University, Montréal, QC, Canada; Department of Biochemistry and Molecular Biology, The University of British Columbia, Vancouver, BC, Canada.
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20
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Gratuze M, Leyns CE, Sauerbeck AD, St-Pierre MK, Xiong M, Kim N, Serrano JR, Tremblay MÈ, Kummer TT, Colonna M, Ulrich JD, Holtzman DM. Impact of TREM2R47H variant on tau pathology-induced gliosis and neurodegeneration. J Clin Invest 2021; 130:4954-4968. [PMID: 32544086 DOI: 10.1172/jci138179] [Citation(s) in RCA: 125] [Impact Index Per Article: 41.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Accepted: 06/10/2020] [Indexed: 12/24/2022] Open
Abstract
Alzheimer's disease (AD) is characterized by plaques containing amyloid-β (Aβ) and neurofibrillary tangles composed of aggregated, hyperphosphorylated tau. Beyond tau and Aβ, evidence suggests that microglia play an important role in AD pathogenesis. Rare variants in the microglia-expressed triggering receptor expressed on myeloid cells 2 (TREM2) gene increase AD risk 2- to 4-fold. It is likely that these TREM2 variants increase AD risk by decreasing the response of microglia to Aβ and its local toxicity. However, neocortical Aβ pathology occurs many years before neocortical tau pathology in AD. Thus, it will be important to understand the role of TREM2 in the context of tauopathy. We investigated the impact of the AD-associated TREM2 variant (R47H) on tau-mediated neuropathology in the PS19 mouse model of tauopathy. We assessed PS19 mice expressing human TREM2CV (common variant) or human TREM2R47H. PS19-TREM2R47H mice had significantly attenuated brain atrophy and synapse loss versus PS19-TREM2CV mice. Gene expression analyses and CD68 immunostaining revealed attenuated microglial reactivity in PS19-TREM2R47H versus PS19-TREM2CV mice. There was also a decrease in phagocytosis of postsynaptic elements by microglia expressing TREM2R47H in the PS19 mice and in human AD brains. These findings suggest that impaired TREM2 signaling reduces microglia-mediated neurodegeneration in the setting of tauopathy.
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Affiliation(s)
- Maud Gratuze
- Department of Neurology.,Hope Center for Neurological Disorders, and.,Knight Alzheimer's Disease Research Center, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Cheryl Eg Leyns
- Department of Neurology.,Hope Center for Neurological Disorders, and.,Knight Alzheimer's Disease Research Center, Washington University School of Medicine, St. Louis, Missouri, USA
| | | | - Marie-Kim St-Pierre
- Axe Neurosciences, Centre de Recherche, Centre Hospitalier Universitaire (CHU) de Québec-Université Laval, Québec City, Québec, Canada.,Division of Medical Sciences, University of Victoria, Victoria, British Columbia, Canada
| | - Monica Xiong
- Department of Neurology.,Hope Center for Neurological Disorders, and.,Knight Alzheimer's Disease Research Center, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Nayeon Kim
- Department of Neurology.,Hope Center for Neurological Disorders, and.,Knight Alzheimer's Disease Research Center, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Javier Remolina Serrano
- Department of Neurology.,Hope Center for Neurological Disorders, and.,Knight Alzheimer's Disease Research Center, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Marie-Ève Tremblay
- Axe Neurosciences, Centre de Recherche, Centre Hospitalier Universitaire (CHU) de Québec-Université Laval, Québec City, Québec, Canada.,Division of Medical Sciences, University of Victoria, Victoria, British Columbia, Canada
| | | | - Marco Colonna
- Hope Center for Neurological Disorders, and.,Knight Alzheimer's Disease Research Center, Washington University School of Medicine, St. Louis, Missouri, USA.,Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Jason D Ulrich
- Department of Neurology.,Hope Center for Neurological Disorders, and.,Knight Alzheimer's Disease Research Center, Washington University School of Medicine, St. Louis, Missouri, USA
| | - David M Holtzman
- Department of Neurology.,Hope Center for Neurological Disorders, and.,Knight Alzheimer's Disease Research Center, Washington University School of Medicine, St. Louis, Missouri, USA
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21
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Abstract
Unraveling the fine structure of the brain is important to provide a better understanding of its normal and abnormal functioning. Application of high-resolution electron microscopic techniques gives us an unprecedented opportunity to discern details of the brain parenchyma at nanoscale resolution, although identifying different cell types and their unique features in two-dimensional, or three-dimensional images, remains a challenge even to experts in the field. This article provides insights into how to identify the different cell types in the central nervous system, based on nuclear and cytoplasmic features, amongst other unique characteristics. From the basic distinction between neurons and their supporting cells, the glia, to differences in their subcellular compartments, organelles and their interactions, ultrastructural analyses can provide unique insights into the changes in brain function during aging and disease conditions, such as stroke, neurodegeneration, infection and trauma. Brain parenchyma is composed of a dense mixture of neuronal and glial cell bodies, together with their intertwined processes. Intracellular components that vary between cells, and can become altered with aging or disease, relate to the cytoplasmic and nucleoplasmic density, nuclear heterochromatin pattern, mitochondria, endoplasmic reticulum and Golgi complex, lysosomes, neurosecretory vesicles, and cytoskeletal elements (actin, intermediate filaments, and microtubules). Applying immunolabeling techniques to visualize membrane-bound or intracellular proteins in neurons and glial cells gives an even better appreciation of the subtle differences unique to these cells across contexts of health and disease. Together, our observations reveal how simple ultrastructural features can be used to identify specific changes in cell types, their health status, and functional relationships in the brain.
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Affiliation(s)
- Patrick C Nahirney
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
| | - Marie-Eve Tremblay
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
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22
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Lecours C, St-Pierre MK, Picard K, Bordeleau M, Bourque M, Awogbindin IO, Benadjal A, Ibanez FG, Gagnon D, Cantin L, Parent M, Di Paolo T, Tremblay ME. Levodopa partially rescues microglial numerical, morphological, and phagolysosomal alterations in a monkey model of Parkinson's disease. Brain Behav Immun 2020; 90:81-96. [PMID: 32755645 DOI: 10.1016/j.bbi.2020.07.044] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/11/2020] [Revised: 07/23/2020] [Accepted: 07/29/2020] [Indexed: 02/07/2023] Open
Abstract
Parkinson's disease (PD) is the most common neurodegenerative motor disorder. The mechanisms underlying the onset and progression of Levodopa (L-Dopa)-induced dyskinesia (LID) during PD treatment remain elusive. Emerging evidence implicates functional modification of microglia in the development of LID. Thus, understanding the link between microglia and the development of LID may provide the knowledge required to preserve or promote beneficial microglial functions, even during a prolonged L-Dopa treatment. To provide novel insights into microglial functional alterations in PD pathophysiology, we characterized their density, morphology, ultrastructure, and degradation activity in the sensorimotor functional territory of the putamen, using 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) cynomolgus monkeys. A subset of MPTP monkeys was treated orally with L-Dopa and developed LID similar to PD patients. Using a combination of light, confocal and transmission electron microscopy, our quantitative analyses revealed alterations of microglial density, morphology and phagolysosomal activity following MPTP intoxication that were partially normalized with L-Dopa treatment. In particular, microglial density, cell body and arborization areas were increased in the MPTP monkeys, whereas L-Dopa-treated MPTP animals presented a microglial phenotype similar to the control animals. At the ultrastructural level, microglia did not differ between groups in their markers of cellular stress or aging. Nevertheless, microglia from the MPTP monkeys displayed reduced numbers of endosomes, compared with control animals, that remained lower after L-Dopa treatment. Microglia from MPTP monkeys treated with L-Dopa also had increased numbers of primary lysosomes compared with non-treated MPTP animals, while secondary and tertiary lysosomes remained unchanged. Moreover, a decrease microglial immunoreactivity for CD68, considered a marker of phagocytosis and lysosomal activity, was measured in the MPTP monkeys treated with L-Dopa, compared with non-treated MPTP animals. Taken together, these findings revealed significant changes in microglia during PD pathophysiology that were partially rescued by L-Dopa treatment. Albeit, this L-Dopa treatment conferred phagolysosomal insufficiency on microglia in the dyskinetic Parkinsonian monkeys.
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Affiliation(s)
- Cynthia Lecours
- Axe Neurosciences, Centre de Recherche du CHU de Québec-Université Laval, Québec, QC, Canada; Faculté de Pharmacie, Université Laval, Québec, QC, Canada
| | - Marie-Kim St-Pierre
- Axe Neurosciences, Centre de Recherche du CHU de Québec-Université Laval, Québec, QC, Canada
| | - Katherine Picard
- Axe Neurosciences, Centre de Recherche du CHU de Québec-Université Laval, Québec, QC, Canada
| | - Maude Bordeleau
- Axe Neurosciences, Centre de Recherche du CHU de Québec-Université Laval, Québec, QC, Canada; Integrated Program of Neuroscience, Faculty of Medicine, McGill University, Montréal, QC, Canada
| | - Melanie Bourque
- Axe Neurosciences, Centre de Recherche du CHU de Québec-Université Laval, Québec, QC, Canada
| | - Ifeoluwa Oluleke Awogbindin
- Axe Neurosciences, Centre de Recherche du CHU de Québec-Université Laval, Québec, QC, Canada; Neuroimmunology Group, Molecular Drug Metabolism and Toxicology Laboratory, Department of Biochemistry, University of Ibadan, Ibadan, Nigeria
| | - Amin Benadjal
- Axe Neurosciences, Centre de Recherche du CHU de Québec-Université Laval, Québec, QC, Canada; Biologie Intégrative et Physiologie, Sorbonne Université, Paris VI, France
| | | | - Dave Gagnon
- Département de Psychiatrie et de Neurosciences, Faculté de Médecine, Université Laval, Québec, QC, Canada; CERVO Brain Research Center, Québec, QC, Canada
| | - Leo Cantin
- Axe Neurosciences, Centre de Recherche du CHU de Québec-Université Laval, Québec, QC, Canada; Département de Chirurgie, Faculté de Médecine, Université Laval, Québec, QC, Canada
| | - Martin Parent
- Département de Psychiatrie et de Neurosciences, Faculté de Médecine, Université Laval, Québec, QC, Canada; CERVO Brain Research Center, Québec, QC, Canada
| | - Therese Di Paolo
- Axe Neurosciences, Centre de Recherche du CHU de Québec-Université Laval, Québec, QC, Canada; Faculté de Pharmacie, Université Laval, Québec, QC, Canada.
| | - Marie-Eve Tremblay
- Axe Neurosciences, Centre de Recherche du CHU de Québec-Université Laval, Québec, QC, Canada; Département de Médecine Moléculaire, Faculté de Médecine, Université Laval, Québec, 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.
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23
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Bordeleau M, Lacabanne C, Fernández de Cossío L, Vernoux N, Savage JC, González-Ibáñez F, Tremblay MÈ. Microglial and peripheral immune priming is partially sexually dimorphic in adolescent mouse offspring exposed to maternal high-fat diet. J Neuroinflammation 2020; 17:264. [PMID: 32891154 PMCID: PMC7487673 DOI: 10.1186/s12974-020-01914-1] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Accepted: 07/29/2020] [Indexed: 12/12/2022] Open
Abstract
Background Maternal nutrition is critical for proper fetal development. While increased nutrient intake is essential during pregnancy, an excessive consumption of certain nutrients, like fat, can lead to long-lasting detrimental consequences on the offspring. Animal work investigating the consequences of maternal high-fat diet (mHFD) revealed in the offspring a maternal immune activation (MIA) phenotype associated with increased inflammatory signals. This inflammation was proposed as one of the mechanisms causing neuronal circuit dysfunction, notably in the hippocampus, by altering the brain-resident macrophages—microglia. However, the understanding of mechanisms linking inflammation and microglial activities to pathological brain development remains limited. We hypothesized that mHFD-induced inflammation could prime microglia by altering their specific gene expression signature, population density, and/or functions. Methods We used an integrative approach combining molecular (i.e., multiplex-ELISA, rt-qPCR) and cellular (i.e., histochemistry, electron microscopy) techniques to investigate the effects of mHFD (saturated and unsaturated fats) vs control diet on inflammatory priming, as well as microglial transcriptomic signature, density, distribution, morphology, and ultrastructure in mice. These analyses were performed on the mothers and/or their adolescent offspring at postnatal day 30. Results Our study revealed that mHFD results in MIA defined by increased circulating levels of interleukin (IL)-6 in the mothers. This phenotype was associated with an exacerbated inflammatory response to peripheral lipopolysaccharide in mHFD-exposed offspring of both sexes. Microglial morphology was also altered, and there were increased microglial interactions with astrocytes in the hippocampus CA1 of mHFD-exposed male offspring, as well as decreased microglia-associated extracellular space pockets in the same region of mHFD-exposed offspring of the two sexes. A decreased mRNA expression of the inflammatory-regulating cytokine Tgfb1 and microglial receptors Tmem119, Trem2, and Cx3cr1 was additionally measured in the hippocampus of mHFD-exposed offspring, especially in males. Conclusions Here, we described how dietary habits during pregnancy and nurturing, particularly the consumption of an enriched fat diet, can influence peripheral immune priming in the offspring. We also found that microglia are affected in terms of gene expression signature, morphology, and interactions with the hippocampal parenchyma, in a partially sexually dimorphic manner, which may contribute to the adverse neurodevelopmental outcomes on the offspring.
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Affiliation(s)
- Maude Bordeleau
- Integrated Program in Neuroscience, McGill University, Montreal, QC, Canada.,Axe neurosciences, Centre de recherche du CHU de Québec-Université Laval, Québec, QC, Canada.,Cerebral Imaging Center, Douglas Mental Health University Institute, McGill University, Montréal, QC, Canada
| | - Chloé Lacabanne
- Integrated Program in Neuroscience, McGill University, Montreal, QC, Canada
| | | | - Nathalie Vernoux
- Axe neurosciences, Centre de recherche du CHU de Québec-Université Laval, Québec, QC, Canada
| | - Julie C Savage
- Axe neurosciences, Centre de recherche du CHU de Québec-Université Laval, Québec, QC, Canada.,Département de médecine moléculaire, Université Laval, Québec, QC, Canada
| | - Fernando González-Ibáñez
- Axe neurosciences, Centre de recherche du CHU de Québec-Université Laval, Québec, QC, Canada.,Département de médecine moléculaire, Université Laval, Québec, QC, Canada
| | - Marie-Ève Tremblay
- Axe neurosciences, Centre de recherche du CHU de Québec-Université Laval, Québec, QC, Canada. .,Département de médecine moléculaire, Université Laval, Québec, QC, Canada. .,Department of Neurology and Neurosurgery, McGill University, Montréal, QC, Canada. .,Division of Medical Sciences, University of Victoria, Victoria, BC, Canada. .,Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, BC, Canada.
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