1
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Green TRF, Rowe RK. Quantifying microglial morphology: an insight into function. Clin Exp Immunol 2024; 216:221-229. [PMID: 38456795 PMCID: PMC11097915 DOI: 10.1093/cei/uxae023] [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: 08/09/2023] [Revised: 01/17/2024] [Accepted: 03/06/2024] [Indexed: 03/09/2024] Open
Abstract
Microglia are specialized immune cells unique to the central nervous system (CNS). Microglia have a highly plastic morphology that changes rapidly in response to injury or infection. Qualitative and quantitative measurements of ever-changing microglial morphology are considered a cornerstone of many microglia-centric research studies. The distinctive morphological variations seen in microglia are a useful marker of inflammation and severity of tissue damage. Although a wide array of damage-associated microglial morphologies has been documented, the exact functions of these distinct morphologies are not fully understood. In this review, we discuss how microglia morphology is not synonymous with microglia function, however, morphological outcomes can be used to make inferences about microglial function. For a comprehensive examination of the reactive status of a microglial cell, both histological and genetic approaches should be combined. However, the importance of quality immunohistochemistry-based analyses should not be overlooked as they can succinctly answer many research questions.
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Affiliation(s)
- Tabitha R F Green
- Department of Integrative Physiology, The University of Colorado Boulder, Boulder, CO, USA
| | - Rachel K Rowe
- Department of Integrative Physiology, The University of Colorado Boulder, Boulder, CO, USA
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2
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Deng W, Yi P, Xiong Y, Ying J, Lin Y, Dong Y, Wei G, Wang X, Hua F. Gut Metabolites Acting on the Gut-Brain Axis: Regulating the Functional State of Microglia. Aging Dis 2024; 15:480-502. [PMID: 37548933 PMCID: PMC10917527 DOI: 10.14336/ad.2023.0727] [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: 05/25/2023] [Accepted: 07/27/2023] [Indexed: 08/08/2023] Open
Abstract
The gut-brain axis is a communication channel that mediates a complex interplay of intestinal flora with the neural, endocrine, and immune systems, linking gut and brain functions. Gut metabolites, a group of small molecules produced or consumed by biochemical processes in the gut, are involved in central nervous system regulation via the highly interconnected gut-brain axis affecting microglia indirectly by influencing the structure of the gut-brain axis or directly affecting microglia function and activity. Accordingly, pathological changes in the central nervous system are connected with changes in intestinal metabolite levels as well as altered microglia function and activity, which may contribute to the pathological process of each neuroinflammatory condition. Here, we discuss the mechanisms by which gut metabolites, for instance, the bile acids, short-chain fatty acids, and tryptophan metabolites, regulate the structure of each component of the gut-brain axis, and explore the important roles of gut metabolites in the central nervous system from the perspective of microglia. At the same time, we highlight the roles of gut metabolites affecting microglia in the pathogenesis of neurodegenerative diseases and neurodevelopmental disorders. Understanding the relationship between microglia, gut microbiota, neuroinflammation, and neurodevelopmental disorders will help us identify new strategies for treating neuropsychiatric disorders.
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Affiliation(s)
- Wenze Deng
- Department of Anesthesiology, the Second Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China.
- Key Laboratory of Anesthesiology of Jiangxi Province, Nanchang City, Jiangxi, China.
| | - Pengcheng Yi
- Department of Anesthesiology, the Second Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China.
- Key Laboratory of Anesthesiology of Jiangxi Province, Nanchang City, Jiangxi, China.
| | - Yanhong Xiong
- Department of Anesthesiology, the Second Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China.
- Key Laboratory of Anesthesiology of Jiangxi Province, Nanchang City, Jiangxi, China.
| | - Jun Ying
- Department of Anesthesiology, the Second Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China.
- Key Laboratory of Anesthesiology of Jiangxi Province, Nanchang City, Jiangxi, China.
| | - Yue Lin
- Department of Anesthesiology, the Second Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China.
- Key Laboratory of Anesthesiology of Jiangxi Province, Nanchang City, Jiangxi, China.
| | - Yao Dong
- Department of Anesthesiology, the Second Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China.
- Key Laboratory of Anesthesiology of Jiangxi Province, Nanchang City, Jiangxi, China.
| | - Gen Wei
- Department of Anesthesiology, the Second Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China.
- Key Laboratory of Anesthesiology of Jiangxi Province, Nanchang City, Jiangxi, China.
| | - Xifeng Wang
- Department of Anesthesiology, the First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China.
| | - Fuzhou Hua
- Department of Anesthesiology, the Second Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China.
- Key Laboratory of Anesthesiology of Jiangxi Province, Nanchang City, Jiangxi, China.
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3
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Neațu M, Covaliu A, Ioniță I, Jugurt A, Davidescu EI, Popescu BO. Monoclonal Antibody Therapy in Alzheimer's Disease. Pharmaceutics 2023; 16:60. [PMID: 38258071 PMCID: PMC11154277 DOI: 10.3390/pharmaceutics16010060] [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: 11/03/2023] [Revised: 12/22/2023] [Accepted: 12/28/2023] [Indexed: 01/24/2024] Open
Abstract
Alzheimer's disease is a neurodegenerative condition marked by the progressive deterioration of cognitive abilities, memory impairment, and the accumulation of abnormal proteins, specifically beta-amyloid plaques and tau tangles, within the brain. Despite extensive research efforts, Alzheimer's disease remains without a cure, presenting a significant global healthcare challenge. Recently, there has been an increased focus on antibody-based treatments as a potentially effective method for dealing with Alzheimer's disease. This paper offers a comprehensive overview of the current status of research on antibody-based molecules as therapies for Alzheimer's disease. We will briefly mention their mechanisms of action, therapeutic efficacy, and safety profiles while addressing the challenges and limitations encountered during their development. We also highlight some crucial considerations in antibody-based treatment development, including patient selection criteria, dosing regimens, or safety concerns. In conclusion, antibody-based therapies present a hopeful outlook for addressing Alzheimer's disease. While challenges remain, the accumulating evidence suggests that these therapies may offer substantial promise in ameliorating or preventing the progression of this debilitating condition, thus potentially enhancing the quality of life for the millions of individuals and families affected by Alzheimer's disease worldwide.
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Affiliation(s)
- Monica Neațu
- Department of Clinical Neurosciences, “Carol Davila” University of Medicine and Pharmacy, 050474 Bucharest, Romania; (M.N.); (A.C.); (I.I.); (A.J.); (B.O.P.)
- Department of Neurology, Colentina Clinical Hospital, 020125 Bucharest, Romania
| | - Anca Covaliu
- Department of Clinical Neurosciences, “Carol Davila” University of Medicine and Pharmacy, 050474 Bucharest, Romania; (M.N.); (A.C.); (I.I.); (A.J.); (B.O.P.)
- Department of Neurology, Colentina Clinical Hospital, 020125 Bucharest, Romania
| | - Iulia Ioniță
- Department of Clinical Neurosciences, “Carol Davila” University of Medicine and Pharmacy, 050474 Bucharest, Romania; (M.N.); (A.C.); (I.I.); (A.J.); (B.O.P.)
- Department of Neurology, Colentina Clinical Hospital, 020125 Bucharest, Romania
| | - Ana Jugurt
- Department of Clinical Neurosciences, “Carol Davila” University of Medicine and Pharmacy, 050474 Bucharest, Romania; (M.N.); (A.C.); (I.I.); (A.J.); (B.O.P.)
- Department of Neurology, Colentina Clinical Hospital, 020125 Bucharest, Romania
| | - Eugenia Irene Davidescu
- Department of Clinical Neurosciences, “Carol Davila” University of Medicine and Pharmacy, 050474 Bucharest, Romania; (M.N.); (A.C.); (I.I.); (A.J.); (B.O.P.)
- Department of Neurology, Colentina Clinical Hospital, 020125 Bucharest, Romania
| | - Bogdan Ovidiu Popescu
- Department of Clinical Neurosciences, “Carol Davila” University of Medicine and Pharmacy, 050474 Bucharest, Romania; (M.N.); (A.C.); (I.I.); (A.J.); (B.O.P.)
- Department of Neurology, Colentina Clinical Hospital, 020125 Bucharest, Romania
- Department of Cell Biology, Neurosciences and Experimental Myology, “Victor Babeș” National Institute of Pathology, 050096 Bucharest, Romania
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4
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Ju LS, Morey TE, Seubert CN, Martynyuk AE. Intergenerational Perioperative Neurocognitive Disorder. BIOLOGY 2023; 12:biology12040567. [PMID: 37106766 PMCID: PMC10135810 DOI: 10.3390/biology12040567] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 04/04/2023] [Accepted: 04/05/2023] [Indexed: 04/29/2023]
Abstract
Accelerated neurocognitive decline after general anesthesia/surgery, also known as perioperative neurocognitive disorder (PND), is a widely recognized public health problem that may affect millions of patients each year. Advanced age, with its increasing prevalence of heightened stress, inflammation, and neurodegenerative alterations, is a consistent contributing factor to the development of PND. Although a strong homeostatic reserve in young adults makes them more resilient to PND, animal data suggest that young adults with pathophysiological conditions characterized by excessive stress and inflammation may be vulnerable to PND, and this altered phenotype may be passed to future offspring (intergenerational PND). The purpose of this narrative review of data in the literature and the authors' own experimental findings in rodents is to draw attention to the possibility of intergenerational PND, a new phenomenon which, if confirmed in humans, may unravel a big new population that may be affected by parental PND. In particular, we discuss the roles of stress, inflammation, and epigenetic alterations in the development of PND. We also discuss experimental findings that demonstrate the effects of surgery, traumatic brain injury, and the general anesthetic sevoflurane that interact to induce persistent dysregulation of the stress response system, inflammation markers, and behavior in young adult male rats and in their future offspring who have neither trauma nor anesthetic exposure (i.e., an animal model of intergenerational PND).
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Affiliation(s)
- Ling-Sha Ju
- Department of Anesthesiology, College of Medicine, University of Florida, P.O. Box 100254, JHMHC, 1600 SW Archer Road, Gainesville, FL 32610, USA
| | - Timothy E Morey
- Department of Anesthesiology, College of Medicine, University of Florida, P.O. Box 100254, JHMHC, 1600 SW Archer Road, Gainesville, FL 32610, USA
| | - Christoph N Seubert
- Department of Anesthesiology, College of Medicine, University of Florida, P.O. Box 100254, JHMHC, 1600 SW Archer Road, Gainesville, FL 32610, USA
| | - Anatoly E Martynyuk
- Department of Anesthesiology, College of Medicine, University of Florida, P.O. Box 100254, JHMHC, 1600 SW Archer Road, Gainesville, FL 32610, USA
- Brain Institute, College of Medicine, University of Florida, Gainesville, FL 32610, USA
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5
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Peng L, Hu G, Yao Q, Wu J, He Z, Law BYK, Hu G, Zhou X, Du J, Wu A, Yu L. Microglia autophagy in ischemic stroke: A double-edged sword. Front Immunol 2022; 13:1013311. [PMID: 36466850 PMCID: PMC9708732 DOI: 10.3389/fimmu.2022.1013311] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2022] [Accepted: 10/25/2022] [Indexed: 08/14/2023] Open
Abstract
Ischemic stroke (IS) is one of the major types of cerebrovascular diseases causing neurological morbidity and mortality worldwide. In the pathophysiological process of IS, microglia play a beneficial role in tissue repair. However, it could also cause cellular damage, consequently leading to cell death. Inflammation is characterized by the activation of microglia, and increasing evidence showed that autophagy interacts with inflammation through regulating correlative mediators and signaling pathways. In this paper, we summarized the beneficial and harmful effects of microglia in IS. In addition, we discussed the interplay between microglia autophagy and ischemic inflammation, as along with its application in the treatment of IS. We believe this could help to provide the theoretical references for further study into IS and treatments in the future.
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Affiliation(s)
- Li Peng
- Sichuan Key Medical Laboratory of New Drug Discovery and Druggability Evaluation, School of Pharmacy, Southwest Medical University, Luzhou, China
- Luzhou Key Laboratory of Activity Screening and Druggability Evaluation for Chinese Materia Medica, School of Pharmacy, Southwest Medical University, Luzhou, China
- Department of Medicine Imaging, School of Clinical Medicine, Southwest Medical University, Luzhou, China
| | - Guangqiang Hu
- Department of Anatomy, School of Basic Medical Sciences, Southwest Medical University, Luzhou, China
| | - Qianfang Yao
- Sichuan Key Medical Laboratory of New Drug Discovery and Druggability Evaluation, School of Pharmacy, Southwest Medical University, Luzhou, China
- Luzhou Key Laboratory of Activity Screening and Druggability Evaluation for Chinese Materia Medica, School of Pharmacy, Southwest Medical University, Luzhou, China
| | - Jianming Wu
- Sichuan Key Medical Laboratory of New Drug Discovery and Druggability Evaluation, School of Pharmacy, Southwest Medical University, Luzhou, China
- Luzhou Key Laboratory of Activity Screening and Druggability Evaluation for Chinese Materia Medica, School of Pharmacy, Southwest Medical University, Luzhou, China
| | - Ziyang He
- Sichuan Key Medical Laboratory of New Drug Discovery and Druggability Evaluation, School of Pharmacy, Southwest Medical University, Luzhou, China
- Luzhou Key Laboratory of Activity Screening and Druggability Evaluation for Chinese Materia Medica, School of Pharmacy, Southwest Medical University, Luzhou, China
| | - Betty Yuen-Kwan Law
- State Key Laboratory of Quality Research in Chinese Medicine, Macau University of Science and Technology, Macao, Macao SAR, China
| | - Guishan Hu
- Sichuan Key Medical Laboratory of New Drug Discovery and Druggability Evaluation, School of Pharmacy, Southwest Medical University, Luzhou, China
- Luzhou Key Laboratory of Activity Screening and Druggability Evaluation for Chinese Materia Medica, School of Pharmacy, Southwest Medical University, Luzhou, China
| | - Xiaogang Zhou
- Sichuan Key Medical Laboratory of New Drug Discovery and Druggability Evaluation, School of Pharmacy, Southwest Medical University, Luzhou, China
- Luzhou Key Laboratory of Activity Screening and Druggability Evaluation for Chinese Materia Medica, School of Pharmacy, Southwest Medical University, Luzhou, China
| | - Junrong Du
- Key Laboratory of Drug Targeting and Drug Delivery Systems of Ministry of Education, Department of Pharmacology, West China School of Pharmacy, Sichuan University, Chengdu, China
| | - Anguo Wu
- Sichuan Key Medical Laboratory of New Drug Discovery and Druggability Evaluation, School of Pharmacy, Southwest Medical University, Luzhou, China
- Luzhou Key Laboratory of Activity Screening and Druggability Evaluation for Chinese Materia Medica, School of Pharmacy, Southwest Medical University, Luzhou, China
| | - Lu Yu
- Sichuan Key Medical Laboratory of New Drug Discovery and Druggability Evaluation, School of Pharmacy, Southwest Medical University, Luzhou, China
- Luzhou Key Laboratory of Activity Screening and Druggability Evaluation for Chinese Materia Medica, School of Pharmacy, Southwest Medical University, Luzhou, China
- Department of Medicine Imaging, School of Clinical Medicine, Southwest Medical University, Luzhou, China
- Department of Chemistry, School of Basic Medical Sciences, Southwest Medical University, Luzhou, China
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6
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Vidal-Itriago A, Radford RAW, Aramideh JA, Maurel C, Scherer NM, Don EK, Lee A, Chung RS, Graeber MB, Morsch M. Microglia morphophysiological diversity and its implications for the CNS. Front Immunol 2022; 13:997786. [PMID: 36341385 PMCID: PMC9627549 DOI: 10.3389/fimmu.2022.997786] [Citation(s) in RCA: 59] [Impact Index Per Article: 29.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Accepted: 09/20/2022] [Indexed: 07/30/2023] Open
Abstract
Microglia are mononuclear phagocytes of mesodermal origin that migrate to the central nervous system (CNS) during the early stages of embryonic development. After colonizing the CNS, they proliferate and remain able to self-renew throughout life, maintaining the number of microglia around 5-12% of the cells in the CNS parenchyma. They are considered to play key roles in development, homeostasis and innate immunity of the CNS. Microglia are exceptionally diverse in their morphological characteristics, actively modifying the shape of their processes and soma in response to different stimuli. This broad morphological spectrum of microglia responses is considered to be closely correlated to their diverse range of functions in health and disease. However, the morphophysiological attributes of microglia, and the structural and functional features of microglia-neuron interactions, remain largely unknown. Here, we assess the current knowledge of the diverse microglial morphologies, with a focus on the correlation between microglial shape and function. We also outline some of the current challenges, opportunities, and future directions that will help us to tackle unanswered questions about microglia, and to continue unravelling the mysteries of microglia, in all its shapes.
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Affiliation(s)
- Andrés Vidal-Itriago
- Faculty of Medicine, Health and Human Sciences, Macquarie Medical School, Macquarie University, Sydney, NSW, Australia
| | - Rowan A. W. Radford
- Faculty of Medicine, Health and Human Sciences, Macquarie Medical School, Macquarie University, Sydney, NSW, Australia
| | - Jason A. Aramideh
- Brain and Mind Centre, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia
| | - Cindy Maurel
- Faculty of Medicine, Health and Human Sciences, Macquarie Medical School, Macquarie University, Sydney, NSW, Australia
| | - Natalie M. Scherer
- Faculty of Medicine, Health and Human Sciences, Macquarie Medical School, Macquarie University, Sydney, NSW, Australia
| | - Emily K. Don
- Faculty of Medicine, Health and Human Sciences, Macquarie Medical School, Macquarie University, Sydney, NSW, Australia
| | - Albert Lee
- Faculty of Medicine, Health and Human Sciences, Macquarie Medical School, Macquarie University, Sydney, NSW, Australia
| | - Roger S. Chung
- Faculty of Medicine, Health and Human Sciences, Macquarie Medical School, Macquarie University, Sydney, NSW, Australia
| | - Manuel B. Graeber
- Brain and Mind Centre, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia
| | - Marco Morsch
- Faculty of Medicine, Health and Human Sciences, Macquarie Medical School, Macquarie University, Sydney, NSW, Australia
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7
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Bosch LFP, Kierdorf K. The Shape of μ—How Morphological Analyses Shape the Study of Microglia. Front Cell Neurosci 2022; 16:942462. [PMID: 35846562 PMCID: PMC9276927 DOI: 10.3389/fncel.2022.942462] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Accepted: 06/13/2022] [Indexed: 11/14/2022] Open
Abstract
Microglia, the innate immune cells of the CNS parenchyma, serve as the first line of defense in a myriad of neurodevelopmental, neurodegenerative, and neuroinflammatory conditions. In response to the peripheral inflammation, circulating mediators, and other external signals that are produced by these conditions, microglia dynamically employ different transcriptional programs as well as morphological adaptations to maintain homeostasis. To understand these cells’ function, the field has established a number of essential analysis approaches, such as gene expression, cell quantification, and morphological reconstruction. Although high-throughput approaches are becoming commonplace in regard to other types of analyses (e.g., single-cell scRNA-seq), a similar standard for morphological reconstruction has yet to be established. In this review, we offer an overview of microglial morphological analysis methods, exploring the advantages and disadvantages of each, highlighting a number of key studies, and emphasizing how morphological analysis has significantly contributed to our understanding of microglial function in the CNS parenchyma. In doing so, we advocate for the use of unbiased, automated morphological reconstruction approaches in future studies, in order to capitalize on the valuable information embedded in the cellular structures microglia inhabit.
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Affiliation(s)
- Lance Fredrick Pahutan Bosch
- Institute of Neuropathology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Katrin Kierdorf
- Institute of Neuropathology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Center for Basics in NeuroModulation (NeuroModulBasics), Faculty of Medicine, University of Freiburg, Freiburg, Germany
- CIBSS–Centre for Integrative Biological Signalling Studies, University of Freiburg, Freiburg, Germany
- *Correspondence: Katrin Kierdorf,
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Hristu R, Eftimie LG, Stanciu SG, Glogojeanu RR, Gheorghita P, Stanciu GA. Assessment of Extramammary Paget Disease by Two-Photon Microscopy. Front Med (Lausanne) 2022; 9:839786. [PMID: 35280872 PMCID: PMC8913931 DOI: 10.3389/fmed.2022.839786] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Accepted: 01/24/2022] [Indexed: 12/29/2022] Open
Abstract
Two-photon microscopy techniques are non-linear optical imaging methods which are gaining momentum in the investigation of fixed tissue sections, fresh tissue or even for in vivo experiments. Two-photon excited fluorescence and second harmonic generation are two non-linear optical contrast mechanisms which can be simultaneously used for offering complementary information on the tissue architecture. While the former can originate from endogenous autofluorescence sources (e.g., NADH, FAD, elastin, keratin, lipofuscins, or melanin), or exogenous eosin, the latter is generated in fibrillar structures within living organisms (e.g., collagen and myosin). Here we test the ability of both these contrast mechanisms to highlight features of the extramammary Paget disease on fixed tissue sections prepared for standard histological examination using immunohistochemical markers and hematoxylin and eosin staining. We also demonstrate the label-free abilities of both imaging techniques to highlight histological features on unstained fixed tissue sections. The study demonstrated that two-photon microscopy can detect specific cellular features of the extramammary Paget disease in good correlation with histopathological results.
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Affiliation(s)
- Radu Hristu
- Center for Microscopy-Microanalysis and Information Processing, University Politehnica of Bucharest, Bucharest, Romania
| | - Lucian G. Eftimie
- Center for Microscopy-Microanalysis and Information Processing, University Politehnica of Bucharest, Bucharest, Romania
- Pathology Department, Central University Emergency Military Hospital, Bucharest, Romania
| | - Stefan G. Stanciu
- Center for Microscopy-Microanalysis and Information Processing, University Politehnica of Bucharest, Bucharest, Romania
| | - Remus R. Glogojeanu
- Department of Special Motricity and Medical Recovery, The National University of Physical Education and Sports, Bucharest, Romania
| | - Pavel Gheorghita
- Center for Microscopy-Microanalysis and Information Processing, University Politehnica of Bucharest, Bucharest, Romania
- Faculty of Energetics, University Politehnica of Bucharest, Bucharest, Romania
| | - George A. Stanciu
- Center for Microscopy-Microanalysis and Information Processing, University Politehnica of Bucharest, Bucharest, Romania
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García-Morales V, González-Acedo A, Melguizo-Rodríguez L, Pardo-Moreno T, Costela-Ruiz VJ, Montiel-Troya M, Ramos-Rodríguez JJ. Current Understanding of the Physiopathology, Diagnosis and Therapeutic Approach to Alzheimer's Disease. Biomedicines 2021; 9:1910. [PMID: 34944723 PMCID: PMC8698840 DOI: 10.3390/biomedicines9121910] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Revised: 12/08/2021] [Accepted: 12/10/2021] [Indexed: 02/06/2023] Open
Abstract
Alzheimer's disease (AD) is the most common cause of dementia. It is characterized by cognitive decline and progressive memory loss. The aim of this review was to update the state of knowledge on the pathophysiological mechanisms, diagnostic methods and therapeutic approach to AD. Currently, the amyloid cascade hypothesis remains the leading theory in the pathophysiology of AD. This hypothesis states that amyloid-β (Aβ) deposition triggers a chemical cascade of events leading to the development of AD dementia. The antemortem diagnosis of AD is still based on clinical parameters. Diagnostic procedures in AD include fluid-based biomarkers such as those present in cerebrospinal fluid and plasma or diagnostic imaging methods. Currently, the therapeutic armory available focuses on symptom control and is based on four pillars: pharmacological treatment where acetylcholinesterase inhibitors stand out; pharmacological treatment under investigation which includes drugs focused on the control of Aβ pathology and tau hyperphosphorylation; treatment focusing on risk factors such as diabetes; or nonpharmacological treatments aimed at preventing development of the disease or treating symptoms through occupational therapy or psychological help. AD remains a largely unknown disease. Further research is needed to identify new biomarkers and therapies that can prevent progression of the pathology.
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Affiliation(s)
- Victoria García-Morales
- Department of Biomedicine, Biotechnology and Public Health, Physiology Area, Faculty of Medicine, University of Cádiz, 11003 Cádiz, Spain;
| | - Anabel González-Acedo
- Biomedical Group (BIO277), Department of Nursing, Faculty of Health Sciences, University of Granada, 18016 Granada, Spain; (A.G.-A.); (V.J.C.-R.)
| | - Lucía Melguizo-Rodríguez
- Biomedical Group (BIO277), Department of Nursing, Faculty of Health Sciences, University of Granada, 18016 Granada, Spain; (A.G.-A.); (V.J.C.-R.)
- Instituto de Investigación Biosanitaria, Ibs Granada, 18012 Granada, Spain
| | - Teresa Pardo-Moreno
- Instituto Nacional de Gestión Sanitaria (INGESA), Primary Health Care, 51003 Ceuta, Spain;
| | - Víctor Javier Costela-Ruiz
- Biomedical Group (BIO277), Department of Nursing, Faculty of Health Sciences, University of Granada, 18016 Granada, Spain; (A.G.-A.); (V.J.C.-R.)
- Instituto de Investigación Biosanitaria, Ibs Granada, 18012 Granada, Spain
| | - María Montiel-Troya
- Department of Nursing, Faculty of Health Sciences (Ceuta), University of Granada, 51001 Ceuta, Spain;
| | - Juan José Ramos-Rodríguez
- Department of Physiology, Faculty of Health Sciences (Ceuta), University of Granada, 51001 Ceuta, Spain;
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10
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de Fraga LS, Tassinari ID, Jantsch J, Guedes RP, Bambini-Junior V. 'A picture is worth a thousand words': The use of microscopy for imaging neuroinflammation. Clin Exp Immunol 2021; 206:325-345. [PMID: 34596237 DOI: 10.1111/cei.13669] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 09/21/2021] [Accepted: 09/22/2021] [Indexed: 01/08/2023] Open
Abstract
Since the first studies of the nervous system by the Nobel laureates Camillo Golgi and Santiago Ramon y Cajal using simple dyes and conventional light microscopes, microscopy has come a long way to the most recent techniques that make it possible to perform images in live cells and animals in health and disease. Many pathological conditions of the central nervous system have already been linked to inflammatory responses. In this scenario, several available markers and techniques can help imaging and unveil the neuroinflammatory process. Moreover, microscopy imaging techniques have become even more necessary to validate the large quantity of data generated in the era of 'omics'. This review aims to highlight how to assess neuroinflammation by using microscopy as a tool to provide specific details about the cell's architecture during neuroinflammatory conditions. First, we describe specific markers that have been used in light microscopy studies and that are widely applied to unravel and describe neuroinflammatory mechanisms in distinct conditions. Then, we discuss some important methodologies that facilitate the imaging of these markers, such as immunohistochemistry and immunofluorescence techniques. Emphasis will be given to studies using two-photon microscopy, an approach that revolutionized the real-time assessment of neuroinflammatory processes. Finally, some studies integrating omics with microscopy will be presented. The fusion of these techniques is developing, but the high amount of data generated from these applications will certainly improve comprehension of the molecular mechanisms involved in neuroinflammation.
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Affiliation(s)
- Luciano Stürmer de Fraga
- Programa de Pós-Graduação em Ciências Biológicas: Fisiologia, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil.,Centro de Pesquisa Experimental, Hospital de Clínicas de Porto Alegre (HCPA), Porto Alegre, Brazil
| | - Isadora D'Ávila Tassinari
- Programa de Pós-Graduação em Ciências Biológicas: Fisiologia, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil.,Centro de Pesquisa Experimental, Hospital de Clínicas de Porto Alegre (HCPA), Porto Alegre, Brazil
| | - Jeferson Jantsch
- Programa de Pós-Graduação em Biociências, Universidade Federal de Ciências da Saúde de Porto Alegre (UFCSPA), Porto Alegre, Brazil
| | - Renata Padilha Guedes
- Programa de Pós-Graduação em Biociências, Universidade Federal de Ciências da Saúde de Porto Alegre (UFCSPA), Porto Alegre, Brazil
| | - Victorio Bambini-Junior
- School of Pharmacy and Biomedical Sciences, University of Central Lancashire (UCLan), Preston, UK
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11
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Clarke D, Crombag HS, Hall CN. An open-source pipeline for analysing changes in microglial morphology. Open Biol 2021; 11:210045. [PMID: 34375551 PMCID: PMC8354754 DOI: 10.1098/rsob.210045] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Changes in microglial morphology are powerful indicators of the inflammatory state of the brain. Here, we provide an open-source microglia morphology analysis pipeline that first cleans and registers images of microglia, before extracting 62 parameters describing microglial morphology. It then compares control and 'inflammation' training data and uses dimensionality reduction to generate a single metric of morphological change (an 'inflammation index'). This index can then be calculated for test data to assess inflammation, as we demonstrate by investigating the effect of short-term high-fat diet consumption in heterozygous Cx3CR1-GFP mice, finding no significant effects of diet. Our pipeline represents the first open-source microglia morphology pipeline combining semi-automated image processing and dimensionality reduction. It uses free software (ImageJ and R) and can be applied to a wide variety of experimental paradigms. We anticipate it will enable others to more easily take advantage of the powerful insights microglial morphology analysis provides.
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Affiliation(s)
- Devin Clarke
- School of Psychology and Sussex Neuroscience, The University of Sussex, Falmer, Brighton BN1 9QH, UK
| | - Hans S Crombag
- School of Psychology and Sussex Neuroscience, The University of Sussex, Falmer, Brighton BN1 9QH, UK
| | - Catherine N Hall
- School of Psychology and Sussex Neuroscience, The University of Sussex, Falmer, Brighton BN1 9QH, UK
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12
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Whitelaw BS, Tanny S, Johnston CJ, Majewska AK, O'Banion MK, Marples B. In Vivo Imaging of the Microglial Landscape After Whole Brain Radiation Therapy. Int J Radiat Oncol Biol Phys 2021; 111:1066-1071. [PMID: 34314813 DOI: 10.1016/j.ijrobp.2021.07.038] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Revised: 07/12/2021] [Accepted: 07/16/2021] [Indexed: 12/31/2022]
Abstract
PURPOSE Whole brain radiation therapy (WBRT) is an important treatment for patients with multiple brain metastases, but can also cause cognitive deterioration. Microglia, the resident immune cells of the brain, promote a proinflammatory environment and likely contribute to cognitive decline after WBRT. To investigate the temporal dynamics of the microglial reaction in individual mice to WBRT, we developed a novel in vivo experimental model using cranial window implants and longitudinal imaging. METHODS AND MATERIALS Chronic cranial windows were surgically implanted over the somatosensory cortex of transgenic Cx3cr1-enhanced green fluorescent protein (EGFP)/+ C57BL/6 mice, where microglia were fluorescently tagged with EGFP. Cx3cr1-EGFP/+ mice were also crossed with Thy1-YFP mice to fluorescently dual label microglia and subsets of neurons throughout the brain. Three weeks after window implantation and recovery, computed tomography image guided WBRT was delivered (single dose 10 Gy using two 5 Gy parallel-opposed lateral beams). Radiation dosing was confirmed using radiochromic film. Then, in vivo 2-photon microscopy was used to longitudinally image the microglial landscape and microglial motility at 7 days and 16 days after irradiation in the same mice. RESULTS Film dosimetry confirmed the average delivered dose per beam at midpoint was accurate within 2%, with no attenuation from the window frame. By 7 days after WBRT, significant changes in the microglial landscape were seen, characterized by apparent loss of microglial cells (20%) and significant rearrangements of microglial location with time after irradiation (36% of cells not found in original location). CONCLUSIONS Using longitudinal in vivo 2-photon imaging, this study demonstrated the feasibility of imaging microglia-neuron interactions and defining how microglia react to WBRT in the same mouse. Having demonstrated utility of the model, this experimental paradigm can be used to investigate the dynamic changes of many different brain cell types and their interactions after WBRT and uncover the underlying cellular mechanisms of WBRT-induced cognitive decline.
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Affiliation(s)
| | | | | | - Ania K Majewska
- Department of Neuroscience; Center for Visual Science; Del Monte Neuroscience Institute, University of Rochester, Rochester, New York
| | - M Kerry O'Banion
- Department of Neuroscience; Department of Neurology; Del Monte Neuroscience Institute, University of Rochester, Rochester, New York
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13
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Bernier LP, Brunner C, Cottarelli A, Balbi M. Location Matters: Navigating Regional Heterogeneity of the Neurovascular Unit. Front Cell Neurosci 2021; 15:696540. [PMID: 34276312 PMCID: PMC8277940 DOI: 10.3389/fncel.2021.696540] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Accepted: 05/31/2021] [Indexed: 12/27/2022] Open
Abstract
The neurovascular unit (NVU) of the brain is composed of multiple cell types that act synergistically to modify blood flow to locally match the energy demand of neural activity, as well as to maintain the integrity of the blood-brain barrier (BBB). It is becoming increasingly recognized that the functional specialization, as well as the cellular composition of the NVU varies spatially. This heterogeneity is encountered as variations in vascular and perivascular cells along the arteriole-capillary-venule axis, as well as through differences in NVU composition throughout anatomical regions of the brain. Given the wide variations in metabolic demands between brain regions, especially those of gray vs. white matter, the spatial heterogeneity of the NVU is critical to brain function. Here we review recent evidence demonstrating regional specialization of the NVU between brain regions, by focusing on the heterogeneity of its individual cellular components and briefly discussing novel approaches to investigate NVU diversity.
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Affiliation(s)
- Louis-Philippe Bernier
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada
| | - Clément Brunner
- Neuro-Electronics Research Flanders, Leuven, Belgium.,Vlaams Instituut voor Biotechnologie, Leuven, Belgium.,Interuniversity Microeletronics Centre, Leuven, Belgium.,Department of Neurosciences, KU Leuven, Leuven, Belgium
| | | | - Matilde Balbi
- Queensland Brain Institute, University of Queensland, Brisbane, QLD, Australia
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14
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Parellada E, Gassó P. Glutamate and microglia activation as a driver of dendritic apoptosis: a core pathophysiological mechanism to understand schizophrenia. Transl Psychiatry 2021; 11:271. [PMID: 33958577 PMCID: PMC8102516 DOI: 10.1038/s41398-021-01385-9] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 04/09/2021] [Accepted: 04/20/2021] [Indexed: 02/03/2023] Open
Abstract
Schizophrenia disorder remains an unsolved puzzle. However, the integration of recent findings from genetics, molecular biology, neuroimaging, animal models and translational clinical research offers evidence that the synaptic overpruning hypothesis of schizophrenia needs to be reassessed. During a critical period of neurodevelopment and owing to an imbalance of excitatory glutamatergic pyramidal neurons and inhibitory GABAergic interneurons, a regionally-located glutamate storm might occur, triggering excessive dendritic pruning with the activation of local dendritic apoptosis machinery. The apoptotic loss of dendritic spines would be aggravated by microglia activation through a recently described signaling system from complement abnormalities and proteins of the MHC, thus implicating the immune system in schizophrenia. Overpruning of dendritic spines coupled with aberrant synaptic plasticity, an essential function for learning and memory, would lead to brain misconnections and synaptic inefficiency underlying the primary negative symptoms and cognitive deficits of schizophrenia. This driving hypothesis has relevant therapeutic implications, including the importance of pharmacological interventions during the prodromal phase or the transition to psychosis, targeting apoptosis, microglia cells or the glutamate storm. Future research on apoptosis and brain integrity should combine brain imaging, CSF biomarkers, animal models and cell biology.
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Affiliation(s)
- Eduard Parellada
- Barcelona Clínic Schizophrenia Unit (BCSU). Institute of Neuroscience, Hospital Clínic of Barcelona, University of Barcelona, Barcelona, Catalonia, Spain.
- The August Pi i Sunyer Biomedical Research Institute (IDIBAPS), Barcelona, Catalonia, Spain.
- Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), Madrid, Spain.
| | - Patricia Gassó
- Barcelona Clínic Schizophrenia Unit (BCSU). Institute of Neuroscience, Hospital Clínic of Barcelona, University of Barcelona, Barcelona, Catalonia, Spain
- The August Pi i Sunyer Biomedical Research Institute (IDIBAPS), Barcelona, Catalonia, Spain
- Department of Basic Clinical Practice, Unit of Pharmacology, University of Barcelona, Barcelona, Catalonia, Spain
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15
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Candlish M, Hefendehl JK. Microglia Phenotypes Converge in Aging and Neurodegenerative Disease. Front Neurol 2021; 12:660720. [PMID: 34025562 PMCID: PMC8133315 DOI: 10.3389/fneur.2021.660720] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Accepted: 03/19/2021] [Indexed: 01/22/2023] Open
Abstract
Microglia, the primary immune cells of the central nervous system, hold a multitude of tasks in order to ensure brain homeostasis and are one of the best predictors of biological age on a cellular level. We and others have shown that these long-lived cells undergo an aging process that impedes their ability to perform some of the most vital homeostatic functions such as immune surveillance, acute injury response, and clearance of debris. Microglia have been described as gradually transitioning from a homeostatic state to an activated state in response to various insults, as well as aging. However, microglia show diverse responses to presented stimuli in the form of acute injury or chronic disease. This complexity is potentially further compounded by the distinct alterations that globally occur in the aging process. In this review, we discuss factors that may contribute to microglial aging, as well as transcriptional microglia alterations that occur in old age. We then compare these distinct phenotypic changes with microglial phenotype in neurodegenerative disease.
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Affiliation(s)
- Michael Candlish
- Institute of Cell Biology and Neuroscience, Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Jasmin K Hefendehl
- Institute of Cell Biology and Neuroscience, Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, Frankfurt am Main, Germany
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16
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Choo YW, Jeong J, Jung K. Recent advances in intravital microscopy for investigation of dynamic cellular behavior in vivo. BMB Rep 2021. [PMID: 32475382 PMCID: PMC7396917 DOI: 10.5483/bmbrep.2020.53.7.069] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Currently, most biological research relies on conventional experimental techniques that allow only static analyses at certain time points in vitro or ex vivo. However, if one could visualize cellular dynamics in living organisms, that would provide a unique opportunity to study key biological phenomena in vivo. Intravital microscopy (IVM) encompasses diverse optical systems for direct viewing of objects, including biological structures and individual cells in live animals. With the current development of devices and techniques, IVM addresses important questions in various fields of biological and biomedical sciences. In this mini-review, we provide a general introduction to IVM and examples of recent applications in the field of immunology, oncology, and vascular biology. We also introduce an advanced type of IVM, dubbed real-time IVM, equipped with video-rate resonant scanning. Since the real-time IVM can render cellular dynamics with high temporal resolution in vivo, it allows visualization and analysis of rapid biological processes.
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Affiliation(s)
- Yeon Woong Choo
- Department of Biomedical Sciences, BK21 Plus Biomedical Science Project, Seoul National University College of Medicine, Seoul 03080, Korea
| | - Juhee Jeong
- Department of Biomedical Sciences, BK21 Plus Biomedical Science Project, Seoul National University College of Medicine, Seoul 03080, Korea
| | - Keehoon Jung
- Department of Biomedical Sciences, BK21 Plus Biomedical Science Project, Seoul National University College of Medicine, Seoul 03080; Department of Anatomy and Cell Biology, Seoul National University College of Medicine, Seoul 03080; Institute of Allergy and Clinical Immunology, Seoul National University Medical Research Center, Seoul 03080, Korea
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17
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Epigenetics and Communication Mechanisms in Microglia Activation with a View on Technological Approaches. Biomolecules 2021; 11:biom11020306. [PMID: 33670563 PMCID: PMC7923060 DOI: 10.3390/biom11020306] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 02/12/2021] [Accepted: 02/14/2021] [Indexed: 12/13/2022] Open
Abstract
Microglial cells, the immune cells of the central nervous system (CNS), play a crucial role for the proper brain development and function and in CNS homeostasis. While in physiological conditions, microglia continuously check the state of brain parenchyma, in pathological conditions, microglia can show different activated phenotypes: In the early phases, microglia acquire the M2 phenotype, increasing phagocytosis and releasing neurotrophic and neuroprotective factors. In advanced phases, they acquire the M1 phenotype, becoming neurotoxic and contributing to neurodegeneration. Underlying this phenotypic change, there is a switch in the expression of specific microglial genes, in turn modulated by epigenetic changes, such as DNA methylation, histones post-translational modifications and activity of miRNAs. New roles are attributed to microglial cells, including specific communication with neurons, both through direct cell–cell contact and by release of many different molecules, either directly or indirectly, through extracellular vesicles. In this review, recent findings on the bidirectional interaction between neurons and microglia, in both physiological and pathological conditions, are highlighted, with a focus on the complex field of microglia immunomodulation through epigenetic mechanisms and/or released factors. In addition, advanced technologies used to study these mechanisms, such as microfluidic, 3D culture and in vivo imaging, are presented.
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18
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Liang Y, Walczak P. Long term intravital single cell tracking under multiphoton microscopy. J Neurosci Methods 2020; 349:109042. [PMID: 33340557 DOI: 10.1016/j.jneumeth.2020.109042] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 12/07/2020] [Accepted: 12/11/2020] [Indexed: 12/13/2022]
Abstract
Visualizing and tracking cells over time in a living organism has been a much-coveted dream before the invention of intravital microscopy. The opaque nature of tissue was a major hurdle that was remedied by the multiphoton microscopy. With the advancement of optical imaging and fluorescent labeling tools, intravital high resolution imaging has become increasingly accessible over the past few years. Long-term intravital tracking of single cells (LIST) under multiphoton microscopy provides a unique opportunity to gain insight into the longitudinal changes in the morphology, migration, or function of cells or subcellular structures. It is particularly suitable for studying slow-evolving cellular and molecular events during normal development or disease progression, without losing the opportunity of catching fast events such as calcium signals. Here, we review the application of LIST under 2-photon microscopy in various fields of neurobiology and discuss challenges and new directions in labeling and imaging methods for LIST. Overall, this review provides an overview of current applications of LIST in mammals, which is an emerging field that will contribute to a better understanding of essential molecular and cellular events in health and disease.
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Affiliation(s)
- Yajie Liang
- Department of Diagnostic Radiology and Nuclear Medicine, University of Maryland School of Medicine, Baltimore, MD, USA.
| | - Piotr Walczak
- Department of Diagnostic Radiology and Nuclear Medicine, University of Maryland School of Medicine, Baltimore, MD, USA
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19
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Shipley FB, Dani N, Xu H, Deister C, Cui J, Head JP, Sadegh C, Fame RM, Shannon ML, Flores VI, Kishkovich T, Jang E, Klein EM, Goldey GJ, He K, Zhang Y, Holtzman MJ, Kirchhausen T, Wyart C, Moore CI, Andermann ML, Lehtinen MK. Tracking Calcium Dynamics and Immune Surveillance at the Choroid Plexus Blood-Cerebrospinal Fluid Interface. Neuron 2020; 108:623-639.e10. [PMID: 32961128 PMCID: PMC7847245 DOI: 10.1016/j.neuron.2020.08.024] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Revised: 05/18/2020] [Accepted: 08/25/2020] [Indexed: 12/26/2022]
Abstract
The choroid plexus (ChP) epithelium is a source of secreted signaling factors in cerebrospinal fluid (CSF) and a key barrier between blood and brain. Here, we develop imaging tools to interrogate these functions in adult lateral ventricle ChP in whole-mount explants and in awake mice. By imaging epithelial cells in intact ChP explants, we observed calcium activity and secretory events that increased in frequency following delivery of serotonergic agonists. Using chronic two-photon imaging in awake mice, we observed spontaneous subcellular calcium events as well as strong agonist-evoked calcium activation and cytoplasmic secretion into CSF. Three-dimensional imaging of motility and mobility of multiple types of ChP immune cells at baseline and following immune challenge or focal injury revealed a range of surveillance and defensive behaviors. Together, these tools should help illuminate the diverse functions of this understudied body-brain interface.
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Affiliation(s)
- Frederick B Shipley
- Department of Pathology, Boston Children's Hospital, Boston, MA 02115, USA; Graduate Program in Biophysics, Harvard University, Cambridge, MA 02138, USA
| | - Neil Dani
- Department of Pathology, Boston Children's Hospital, Boston, MA 02115, USA
| | - Huixin Xu
- Department of Pathology, Boston Children's Hospital, Boston, MA 02115, USA
| | - Christopher Deister
- Carney Institute for Brain Science, Brown University, Providence, RI 02912, USA
| | - Jin Cui
- Department of Pathology, Boston Children's Hospital, Boston, MA 02115, USA
| | - Joshua P Head
- Department of Pathology, Boston Children's Hospital, Boston, MA 02115, USA
| | - Cameron Sadegh
- Department of Pathology, Boston Children's Hospital, Boston, MA 02115, USA; Department of Neurosurgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - Ryann M Fame
- Department of Pathology, Boston Children's Hospital, Boston, MA 02115, USA
| | - Morgan L Shannon
- Department of Pathology, Boston Children's Hospital, Boston, MA 02115, USA
| | - Vanessa I Flores
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Beth Israel Deaconess Medical Center, Boston, MA 02115, USA
| | - Thomas Kishkovich
- Carney Institute for Brain Science, Brown University, Providence, RI 02912, USA
| | - Emily Jang
- Carney Institute for Brain Science, Brown University, Providence, RI 02912, USA
| | - Eric M Klein
- Carney Institute for Brain Science, Brown University, Providence, RI 02912, USA
| | - Glenn J Goldey
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Beth Israel Deaconess Medical Center, Boston, MA 02115, USA
| | - Kangmin He
- Department of Cell Biology and Department of Pediatrics, Harvard Medical School, Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, MA 02115, USA
| | - Yong Zhang
- Pulmonary and Critical Care Medicine, Department of Medicine, Washington University, St. Louis, MO 63110, USA
| | - Michael J Holtzman
- Pulmonary and Critical Care Medicine, Department of Medicine, Washington University, St. Louis, MO 63110, USA
| | - Tomas Kirchhausen
- Department of Cell Biology and Department of Pediatrics, Harvard Medical School, Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, MA 02115, USA
| | - Claire Wyart
- Institut du Cerveau et de la Moelle Épinière (ICM), Sorbonne Université, Inserm U1127, CNRS UMR 7225, 75013 Paris, France
| | - Christopher I Moore
- Carney Institute for Brain Science, Brown University, Providence, RI 02912, USA
| | - Mark L Andermann
- Graduate Program in Biophysics, Harvard University, Cambridge, MA 02138, USA; Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Beth Israel Deaconess Medical Center, Boston, MA 02115, USA.
| | - Maria K Lehtinen
- Department of Pathology, Boston Children's Hospital, Boston, MA 02115, USA; Graduate Program in Biophysics, Harvard University, Cambridge, MA 02138, USA.
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20
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Eme-Scolan E, Dando SJ. Tools and Approaches for Studying Microglia In vivo. Front Immunol 2020; 11:583647. [PMID: 33117395 PMCID: PMC7576994 DOI: 10.3389/fimmu.2020.583647] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Accepted: 08/24/2020] [Indexed: 12/13/2022] Open
Abstract
Microglia are specialized resident macrophages of the central nervous system (CNS) that have important functions during neurodevelopment, homeostasis and disease. This mini-review provides an overview of the current tools and approaches for studying microglia in vivo. We focus on tools for labeling microglia, highlighting the advantages and limitations of microglia markers/antibodies and reporter mice. We also discuss techniques for imaging microglia in situ, including in vivo live imaging of brain and retinal microglia. Finally, we review microglia depletion approaches and their use to investigate microglial function in CNS homeostasis and disease.
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Affiliation(s)
- Elisa Eme-Scolan
- École Normale Supérieure de Lyon, Université Claude Bernard Lyon I, Université de Lyon, Lyon, France.,Faculty of Health, Centre for Immunology and Infection Control, School of Biomedical Sciences, Queensland University of Technology (QUT), Brisbane, QLD, Australia
| | - Samantha J Dando
- Faculty of Health, Centre for Immunology and Infection Control, School of Biomedical Sciences, Queensland University of Technology (QUT), Brisbane, QLD, Australia
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21
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Fan W, Mai L, Zhu X, Huang F, He H. The Role of Microglia in Perioperative Neurocognitive Disorders. Front Cell Neurosci 2020; 14:261. [PMID: 32973455 PMCID: PMC7461842 DOI: 10.3389/fncel.2020.00261] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Accepted: 07/27/2020] [Indexed: 12/12/2022] Open
Abstract
Perioperative neurocognitive disorder (PND) is a common phenomenon associated with anesthesia and surgery and has been frequently described in the elderly and susceptible individuals. Microglia, which are the brain’s major resident immune cells, play critical roles in maintaining neuronal homeostasis and synaptic plasticity. Accumulating evidence suggests microglial dysfunction occurring after anesthesia and surgery might perturb neuronal function and induce PND. This review aims to provide an overview of the involvement of microglia in PND to date. Possible cellular and molecular mechanisms regarding the connection between microglial activation and PND are discussed.
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Affiliation(s)
- Wenguo Fan
- Department of Anesthesiology, Guanghua School of Stomatology, Hospital of Stomatology, Sun Yat-sen University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Stomatology, Guangzhou, China
| | - Lijia Mai
- Guangdong Provincial Key Laboratory of Stomatology, Guangzhou, China
| | - Xiao Zhu
- The Marine Biomedical Research Institute, Guangdong Medical University, Zhanjiang, China
| | - Fang Huang
- Guangdong Provincial Key Laboratory of Stomatology, Guangzhou, China
| | - Hongwen He
- Guangdong Provincial Key Laboratory of Stomatology, Guangzhou, China
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22
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Cheng H, Tong S, Deng X, Li J, Qiu P, Wang K. In vivo deep-brain imaging of microglia enabled by three-photon fluorescence microscopy. OPTICS LETTERS 2020; 45:5271-5274. [PMID: 32932509 DOI: 10.1364/ol.408329] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Accepted: 08/26/2020] [Indexed: 06/11/2023]
Abstract
Microglia act as the first and main form of active immune defense in brain. However, in animal models, research on these cells is limited to the superficial layer of the brain, due to the lack of a deep-imaging technique. Here we break this depth limit using three-photon fluorescence (3PF) microscopy excited at the 1700-nm window. Three-photon action cross-section (ησ3) measurement lays the basis for dye selection and the resultant maximization of 3PF generation. 3PF imaging suppresses the surface background, leading to a much improved signal-to-background ratio compared to the commonly used two-photon microscopy (2PM). We can image microglia 1124 µm below the brain surface in vivo, 3.7 times deeper than previous results using 2PM for microglia imaging. This technique enables us to visualize microglia in the white matter layer in vivo for the first time.
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23
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Yang Q, Wu B, Eles JR, Vazquez AL, Kozai TDY, Cui XT. Zwitterionic Polymer Coating Suppresses Microglial Encapsulation to Neural Implants In Vitro and In Vivo. ADVANCED BIOSYSTEMS 2020; 4:e1900287. [PMID: 32363792 PMCID: PMC7686959 DOI: 10.1002/adbi.201900287] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Revised: 03/23/2020] [Accepted: 03/30/2020] [Indexed: 01/08/2023]
Abstract
For brain computer interfaces (BCI), the immune response to implanted electrodes is a major biological cause of device failure. Bioactive coatings such as neural adhesion molecule L1 have been shown to improve the biocompatibility, but are difficult to handle or produce in batches. Here, a synthetic zwitterionic polymer coating, poly(sulfobetaine methacrylate) (PSBMA) is developed for neural implants with the goal of reducing the inflammatory host response. In tests in vitro, the zwitterionic coating inhibits protein adsorption and the attachment of fibroblasts and microglia, and remains stable for at least 4 weeks. In vivo two-photon microscopy on CX3CR1-GFP mice shows that the zwitterionic coating significantly suppresses the microglial encapsulation of neural microelectrodes over a 6 h observation period. Furthermore, the lower microglial encapsulation on zwitterionic polymer-coated microelectrodes is revealed to originate from a reduction in the size but not the number of microglial end feet. This work provides a facile method for coating neural implants with zwitterionic polymers and illustrates the initial interaction between microglia and coated surface at high temporal and spatial resolution.
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Affiliation(s)
- Qianru Yang
- Biomedical Science Tower 3, University of Pittsburgh, 3501 Fifth Ave, Pittsburgh, PA, 15232, USA
| | - Bingchen Wu
- Biomedical Science Tower 3, University of Pittsburgh, 3501 Fifth Ave, Pittsburgh, PA, 15232, USA
| | - James R Eles
- Biomedical Science Tower 3, University of Pittsburgh, 3501 Fifth Ave, Pittsburgh, PA, 15232, USA
| | - Alberto L Vazquez
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, 3025 East Carson Street, Pittsburgh, PA, 15219, USA
| | - Takashi D Y Kozai
- Center for Biotechnology and Bioengineering, University of Pittsburgh, 300 Technology Dr, Pittsburgh, PA, 15213, USA
| | - X Tracy Cui
- Biomedical Science Tower 3, University of Pittsburgh, 3501 Fifth Ave, Pittsburgh, PA, 15232, USA
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24
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Lee SH, Choe YH, Kang RH, Kim YR, Kim NH, Kang S, Kim Y, Park S, Hyun YM, Kim D. A bright blue fluorescent dextran for two-photon in vivo imaging of blood vessels. Bioorg Chem 2019; 89:103019. [DOI: 10.1016/j.bioorg.2019.103019] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Revised: 05/01/2019] [Accepted: 05/28/2019] [Indexed: 01/06/2023]
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25
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Evans TA, Barkauskas DS, Silver J. Intravital imaging of immune cells and their interactions with other cell types in the spinal cord: Experiments with multicolored moving cells. Exp Neurol 2019; 320:112972. [PMID: 31234058 DOI: 10.1016/j.expneurol.2019.112972] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Revised: 05/25/2019] [Accepted: 06/04/2019] [Indexed: 12/25/2022]
Abstract
Intravital imaging of the immune system is a powerful technique for studying biology of the immune response in the spinal cord using a variety of disease models ranging from traumatic injury to autoimmune disorders. Here, we will discuss specific technical aspects as well as many intriguing biological phenomena that have been revealed with the use of intravital imaging for investigation of the immune system in the spinal cord. We will discuss surgical techniques for exposing and stabilizing the spine that are critical for obtaining images, visualizing immune and CNS cells with genetically expressed fluorescent proteins, fluorescent labeling techniques and briefly discuss some of the challenges of image analysis.
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Affiliation(s)
- Teresa A Evans
- Department of Pediatrics, Stanford University, Stanford, CA, USA.
| | | | - Jerry Silver
- Department of Neurosciences, Case Western Reserve University, Cleveland, OH, USA
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Chaves-Filho AJM, Macedo DS, de Lucena DF, Maes M. Shared microglial mechanisms underpinning depression and chronic fatigue syndrome and their comorbidities. Behav Brain Res 2019; 372:111975. [PMID: 31136774 DOI: 10.1016/j.bbr.2019.111975] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Revised: 04/09/2019] [Accepted: 05/23/2019] [Indexed: 12/24/2022]
Abstract
In 2011, it was reviewed that a) there is a strong co-occurrence between major depression and chronic fatigue syndrome (CFS), with fatigue and physio-somatic symptoms being key symptoms of depression, and depressive symptoms appearing during the course of CFS; and b) the comorbidity between both disorders may in part be explained by activated immune-inflammatory pathways, including increased translocation of Gram-negative bacteria and increased levels of pro-inflammatory cytokines, such as interleukin (IL)-1. Nevertheless, the possible involvement of activated microglia in this comorbidity has remained unclear. This paper aims to review microglial disturbances in major depression, CFS and their comorbidity. A comprehensive literature search was conducted using the PubMed / MEDLINE database to identify studies, which are relevant to this current review. Depressed patients present neuroinflammatory alterations, probably related to microglial activation, while animal models show that a microglial response to immune challenges including lipopolysaccharides is accompanied by depressive-like behaviors. Recent evidence from preclinical studies indicates that activated microglia have a key role in the onset of fatigue. In chronic inflammatory conditions, such as infections and senescence, microglia orchestrate an inflammatory microenvironment thereby causing fatigue. In conclusion, based on our review we may posit that shared immune-inflammatory pathways and especially activated microglia underpin comorbid depression and CFS. As such, microglial activation and neuro-inflammation may be promising targets to treat the overlapping manifestations of both depression and CFS.
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Affiliation(s)
- Adriano José Maia Chaves-Filho
- Neuropsychopharmacology Laboratory, Drug Research and Development Center, Faculty of Medicine, Federal University of Ceara, Fortaleza, CE, Brazil.
| | - Danielle S Macedo
- Neuropsychopharmacology Laboratory, Drug Research and Development Center, Faculty of Medicine, Federal University of Ceara, Fortaleza, CE, Brazil; National Institute for Translational Medicine (INCT-TM, CNPq), Ribeirão Preto, Brazil.
| | - David Freitas de Lucena
- Neuropsychopharmacology Laboratory, Drug Research and Development Center, Faculty of Medicine, Federal University of Ceara, Fortaleza, CE, Brazil.
| | - Michael Maes
- Department of Psychiatry, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand; IMPACT Strategic Research Center, Deakin University, Geelong, Australia.
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