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de Groot DMG, Linders L, Kayser R, Nederlof R, de Esch C, Slieker RC, Kuper CF, Wolterbeek A, de Groot VJ, Veltien A, Heerschap A, van Waarde A, Dierckx RAJO, de Vries EFJ. Perinatal exposure to the immune-suppressant di-n-octyltin dichloride affects brain development in rats. Toxicol Mech Methods 2024; 34:283-299. [PMID: 37946400 DOI: 10.1080/15376516.2023.2281610] [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: 08/29/2023] [Accepted: 11/05/2023] [Indexed: 11/12/2023]
Abstract
Disruption of the immune system during embryonic brain development by environmental chemicals was proposed as a possible cause of neurodevelopmental disorders. We previously found adverse effects of di-n-octyltin dichloride (DOTC) on maternal and developing immune systems of rats in an extended one-generation reproductive toxicity study according to the OECD 443 test guideline. We hypothesize that the DOTC-induced changes in the immune system can affect neurodevelopment. Therefore, we used in-vivo MRI and PET imaging and genomics, in addition to behavioral testing and neuropathology as proposed in OECD test guideline 443, to investigate the effect of DOTC on structural and functional brain development. Male rats were exposed to DOTC (0, 3, 10, or 30 mg/kg of diet) from 2 weeks prior to mating of the F0-generation until sacrifice of F1-animals. The brains of rats, exposed to DOTC showed a transiently enlarged volume of specific brain regions (MRI), altered specific gravity, and transient hyper-metabolism ([18F]FDG PET). The alterations in brain development concurred with hyper-responsiveness in auditory startle response and slight hyperactivity in young adult animals. Genomics identified altered transcription of key regulators involved in neurodevelopment and neural function (e.g. Nrgrn, Shank3, Igf1r, Cck, Apba2, Foxp2); and regulators involved in cell size, cell proliferation, and organ development, especially immune system development and functioning (e.g. LOC679869, Itga11, Arhgap5, Cd47, Dlg1, Gas6, Cml5, Mef2c). The results suggest the involvement of immunotoxicity in the impairment of the nervous system by DOTC and support the hypothesis of a close connection between the immune and nervous systems in brain development.
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Affiliation(s)
- Didima M G de Groot
- Department of Toxicology and Applied Pharmacology, TNO Nutrition and Food Research (as part of TNO Quality of Life), Zeist, the Netherlands
| | - Louisa Linders
- Department of Toxicology and Applied Pharmacology, TNO Nutrition and Food Research (as part of TNO Quality of Life), Zeist, the Netherlands
| | - Reinier Kayser
- Department of Toxicology and Applied Pharmacology, TNO Nutrition and Food Research (as part of TNO Quality of Life), Zeist, the Netherlands
| | - Rianne Nederlof
- Department of Toxicology and Applied Pharmacology, TNO Nutrition and Food Research (as part of TNO Quality of Life), Zeist, the Netherlands
| | - Celine de Esch
- Department of Toxicology and Applied Pharmacology, TNO Nutrition and Food Research (as part of TNO Quality of Life), Zeist, the Netherlands
| | - Roderick C Slieker
- Department of Toxicology and Applied Pharmacology, TNO Nutrition and Food Research (as part of TNO Quality of Life), Zeist, the Netherlands
| | - C Frieke Kuper
- Department of Toxicology and Applied Pharmacology, TNO Nutrition and Food Research (as part of TNO Quality of Life), Zeist, the Netherlands
| | - Andre Wolterbeek
- Department of Toxicology and Applied Pharmacology, TNO Nutrition and Food Research (as part of TNO Quality of Life), Zeist, the Netherlands
| | - V Jeroen de Groot
- Department of Toxicology and Applied Pharmacology, TNO Nutrition and Food Research (as part of TNO Quality of Life), Zeist, the Netherlands
| | - Andor Veltien
- Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Arend Heerschap
- Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Aren van Waarde
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Rudi A J O Dierckx
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Erik F J de Vries
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
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2
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Guffart E, Prinz M. Evolution of Microglia. ADVANCES IN NEUROBIOLOGY 2024; 37:39-51. [PMID: 39207685 DOI: 10.1007/978-3-031-55529-9_3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/04/2024]
Abstract
Microglial cells are unique tissue-resident macrophages located in the parenchyma of the central nervous system (CNS). A recent comparative transcriptional study on microglia across more than 20 species from leach across chicken and many more up to humans revealed multiple conserved features. The results indicate the imperative role of microglia over the last 500 million years (Geirsdottir et al. Cell 181:746, 2020). Improved understanding of microglial evolution provides essential insights into conserved and divergent microglial pathways and will have implications for future development of microglia-based therapies to treat CNS disorders. Not only therapeutic approaches may be rethought, but also the understanding of sex specificity of the immune system within the CNS needs to be renewed. Besides revealing the highly detailed characteristics of microglia, the former paradigm of microglia being the only CNS-resident immune cells was outdated by the identification of CNS-associated macrophages (CAMs) as CNS interface residents, who, most likely, accompanied microglia in evolution over the past million years.
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Affiliation(s)
- Elena Guffart
- Institute of Neuropathology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Marco Prinz
- Institute of Neuropathology, Faculty of Medicine, University of Freiburg, Freiburg, Germany.
- Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Freiburg, Germany.
- Center for Basics in NeuroModulation (NeuroModulBasics), Faculty of Medicine, University of Freiburg, Freiburg, Germany.
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3
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Piano I, Votta A, Colucci P, Corsi F, Vitolo S, Cerri C, Puppi D, Lai M, Maya-Vetencourt JF, Leigheb M, Gabellini C, Ferraro E. Anti-inflammatory reprogramming of microglia cells by metabolic modulators to counteract neurodegeneration; a new role for Ranolazine. Sci Rep 2023; 13:20138. [PMID: 37978212 PMCID: PMC10656419 DOI: 10.1038/s41598-023-47540-8] [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: 05/28/2023] [Accepted: 11/14/2023] [Indexed: 11/19/2023] Open
Abstract
Microglia chronic activation is a hallmark of several neurodegenerative diseases, including the retinal ones, possibly contributing to their etiopathogenesis. However, some microglia sub-populations have anti-inflammatory and neuroprotective functions, thus making arduous deciphering the role of these cells in neurodegeneration. Since it has been proposed that functionally different microglia subsets also rely on different metabolic routes, we hypothesized that modulating microglia metabolism might be a tool to enhance their anti-inflammatory features. This would have a preventive and therapeutic potential in counteracting neurodegenerative diseases. For this purpose, we tested various molecules known to act on cell metabolism, and we revealed the anti-inflammatory effect of the FDA-approved piperazine derivative Ranolazine on microglia cells, while confirming the one of the flavonoids Quercetin and Naringenin, both in vitro and in vivo. We also demonstrated the synergistic anti-inflammatory effect of Quercetin and Idebenone, and the ability of Ranolazine, Quercetin and Naringenin to counteract the neurotoxic effect of LPS-activated microglia on 661W neuronal cells. Overall, these data suggest that using the selected molecules -also in combination therapies- might represent a valuable approach to reduce inflammation and neurodegeneration while avoiding long term side effects of corticosteroids.
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Affiliation(s)
- Ilaria Piano
- Department of Pharmacy, University of Pisa, Pisa, Italy
| | - Arianna Votta
- Department of Biology, University of Pisa, Pisa, Italy
| | | | | | - Sara Vitolo
- Department of Biology, University of Pisa, Pisa, Italy
| | - Chiara Cerri
- Department of Pharmacy, University of Pisa, Pisa, Italy
| | - Dario Puppi
- Department of Chemistry and Industrial Chemistry, University of Pisa, Pisa, Italy
| | - Michele Lai
- Retrovirus Center, Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy
| | - José Fernando Maya-Vetencourt
- Department of Biology, University of Pisa, Pisa, Italy
- Centre for Synaptic Neuroscience, Italian Institute of Technology (IIT), Genova, Italy
| | - Massimiliano Leigheb
- Orthopaedics and Traumatology Unit, "Maggiore della Carità" Hospital, Department of Health Sciences, University of Piemonte Orientale (UPO), Novara, Italy
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Martins TG, Soliman R, Cordero-Maldonado ML, Donato C, Ameli C, Mombaerts L, Skupin A, Peri F, Crawford AD. Seizure-induced increase in microglial cell population in the developing zebrafish brain. Epilepsy Res 2023; 195:107203. [PMID: 37572541 DOI: 10.1016/j.eplepsyres.2023.107203] [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: 03/03/2023] [Revised: 06/21/2023] [Accepted: 07/31/2023] [Indexed: 08/14/2023]
Abstract
Epilepsy is a chronic brain disorder characterized by unprovoked and recurrent seizures, of which 60% are of unknown etiology. Recent studies implicate microglia in the pathophysiology of epilepsy. However, their role in this process, in particular following early-life seizures, remains poorly understood due in part to the lack of suitable experimental models allowing the in vivo imaging of microglial activity. Given the advantage of zebrafish larvae for minimally-invasive imaging approaches, we sought for the first time to describe the microglial responses after acute seizures in two different zebrafish larval models: a chemically-induced epileptic model by the systemic injection of kainate at 3 days post-fertilization, and the didys552 genetic epilepsy model, which carries a mutation in scn1lab that leads to spontaneous epileptiform discharges. Kainate-treated larvae exhibited transient brain damage as shown by increased numbers of apoptotic nuclei as early as one day post-injection, which was followed by an increase in the number of microglia in the brain. A similar microglial phenotype was also observed in didys552-/- mutants, suggesting that microglia numbers change in response to seizure-like activity in the brain. Interestingly, kainate-treated larvae also displayed a decreased seizure threshold towards subsequent pentylenetetrazole-induced seizures, as shown by higher locomotor and encephalographic activity in comparison with vehicle-injected larvae. These results are comparable to kainate-induced rodent seizure models and suggest the suitability of these zebrafish seizure models for future studies, in particular to elucidate the links between epileptogenesis and microglial dynamic changes after seizure induction in the developing brain, and to understand how these modulate seizure susceptibility.
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Affiliation(s)
- Teresa G Martins
- Luxembourg Centre for Systems Biomedicine (LCSB), University of Luxembourg, Esch-sur-Alzette, Luxembourg.
| | - Remon Soliman
- Luxembourg Centre for Systems Biomedicine (LCSB), University of Luxembourg, Esch-sur-Alzette, Luxembourg
| | | | - Cristina Donato
- Luxembourg Centre for Systems Biomedicine (LCSB), University of Luxembourg, Esch-sur-Alzette, Luxembourg
| | - Corrado Ameli
- Luxembourg Centre for Systems Biomedicine (LCSB), University of Luxembourg, Esch-sur-Alzette, Luxembourg
| | - Laurent Mombaerts
- Luxembourg Centre for Systems Biomedicine (LCSB), University of Luxembourg, Esch-sur-Alzette, Luxembourg
| | - Alexander Skupin
- Luxembourg Centre for Systems Biomedicine (LCSB), University of Luxembourg, Esch-sur-Alzette, Luxembourg; University of California, San Diego (UCSD), La Jolla, CA, United States
| | - Francesca Peri
- Developmental Biology Group, European Molecular Biology Laboratory (EMBL), Meyerhofstrasse 1, 69117 Heidelberg, Germany
| | - Alexander D Crawford
- Luxembourg Centre for Systems Biomedicine (LCSB), University of Luxembourg, Esch-sur-Alzette, Luxembourg; Institute for Orphan Drug Discovery, Bremerhaven, Germany.
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5
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Barry-Carroll L, Greulich P, Marshall AR, Riecken K, Fehse B, Askew KE, Li K, Garaschuk O, Menassa DA, Gomez-Nicola D. Microglia colonize the developing brain by clonal expansion of highly proliferative progenitors, following allometric scaling. Cell Rep 2023; 42:112425. [PMID: 37099424 DOI: 10.1016/j.celrep.2023.112425] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Revised: 01/25/2023] [Accepted: 04/06/2023] [Indexed: 04/27/2023] Open
Abstract
Microglia arise from the yolk sac and enter the brain during early embryogenesis. Upon entry, microglia undergo in situ proliferation and eventually colonize the entire brain by the third postnatal week in mice. However, the intricacies of their developmental expansion remain unclear. Here, we characterize the proliferative dynamics of microglia during embryonic and postnatal development using complementary fate-mapping techniques. We demonstrate that the developmental colonization of the brain is facilitated by clonal expansion of highly proliferative microglial progenitors that occupy spatial niches throughout the brain. Moreover, the spatial distribution of microglia switches from a clustered to a random pattern between embryonic and late postnatal development. Interestingly, the developmental increase in microglial numbers follows the proportional growth of the brain in an allometric manner until a mosaic distribution has been established. Overall, our findings offer insight into how the competition for space may drive microglial colonization by clonal expansion during development.
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Affiliation(s)
- Liam Barry-Carroll
- School of Biological Sciences, University of Southampton, Southampton General Hospital, Southampton, UK
| | - Philip Greulich
- School of Mathematical Sciences, University of Southampton, Southampton, UK; Institute for Life Sciences (IfLS), University of Southampton, Southampton, UK
| | - Abigail R Marshall
- School of Biological Sciences, University of Southampton, Southampton General Hospital, Southampton, UK
| | - Kristoffer Riecken
- Research Department Cell and Gene Therapy, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Boris Fehse
- Research Department Cell and Gene Therapy, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Katharine E Askew
- School of Biological Sciences, University of Southampton, Southampton General Hospital, Southampton, UK
| | - Kaizhen Li
- Department of Neurophysiology, University of Tübingen, Tübingen, Germany
| | - Olga Garaschuk
- Department of Neurophysiology, University of Tübingen, Tübingen, Germany
| | - David A Menassa
- School of Biological Sciences, University of Southampton, Southampton General Hospital, Southampton, UK; The Queen's College, University of Oxford, Oxford, UK
| | - Diego Gomez-Nicola
- School of Biological Sciences, University of Southampton, Southampton General Hospital, Southampton, UK; Institute for Life Sciences (IfLS), University of Southampton, Southampton, UK.
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6
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Rovira M, Miserocchi M, Montanari A, Hammou L, Chomette L, Pozo J, Imbault V, Bisteau X, Wittamer V. Zebrafish Galectin 3 binding protein is the target antigen of the microglial 4C4 monoclonal antibody. Dev Dyn 2023; 252:400-414. [PMID: 36285351 DOI: 10.1002/dvdy.549] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Revised: 09/15/2022] [Accepted: 10/16/2022] [Indexed: 11/07/2022] Open
Abstract
BACKGROUND Two decades ago, the fish-specific monoclonal antibody 4C4 was found to be highly reactive to zebrafish microglia, the macrophages of the central nervous system. This has resulted in 4C4 being widely used, in combination with available fluorescent transgenic reporters to identify and isolate microglia. However, the target protein of 4C4 remains unidentified, which represents a major caveat. In addition, whether the 4C4 expression pattern is strictly restricted to microglial cells in zebrafish has never been investigated. RESULTS Having demonstrated that 4C4 is able to capture its native antigen from adult brain lysates, we used immunoprecipitation/mass-spectrometry, coupled to recombinant expression analyses, to identify its target. The cognate antigen was found to be a paralog of Galectin 3 binding protein (Lgals3bpb), known as MAC2-binding protein in mammals. Notably, 4C4 did not recognize other paralogs, demonstrating specificity. Moreover, our data show that Lgals3bpb expression, while ubiquitous in microglia, also identifies leukocytes in the periphery, including populations of gut and liver macrophages. CONCLUSIONS The 4C4 monoclonal antibody recognizes Lgals3bpb, a predicted highly glycosylated protein whose function in the microglial lineage is currently unknown. Identification of Lgals3bpb as a new pan-microglia marker will be fundamental in forthcoming studies using the zebrafish model.
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Affiliation(s)
- Mireia Rovira
- Institut de Recherche Interdisciplinaire en Biologie Humaine et Moléculaire (IRIBHM), Université Libre de Bruxelles (ULB), Bruxelles, Belgium
- ULB Neuroscience Institute (UNI), Université Libre de Bruxelles (ULB), Bruxelles, Belgium
| | - Magali Miserocchi
- Institut de Recherche Interdisciplinaire en Biologie Humaine et Moléculaire (IRIBHM), Université Libre de Bruxelles (ULB), Bruxelles, Belgium
- ULB Neuroscience Institute (UNI), Université Libre de Bruxelles (ULB), Bruxelles, Belgium
| | - Alice Montanari
- Institut de Recherche Interdisciplinaire en Biologie Humaine et Moléculaire (IRIBHM), Université Libre de Bruxelles (ULB), Bruxelles, Belgium
- ULB Neuroscience Institute (UNI), Université Libre de Bruxelles (ULB), Bruxelles, Belgium
| | - Latifa Hammou
- Institut de Recherche Interdisciplinaire en Biologie Humaine et Moléculaire (IRIBHM), Université Libre de Bruxelles (ULB), Bruxelles, Belgium
| | - Laura Chomette
- Institut de Recherche Interdisciplinaire en Biologie Humaine et Moléculaire (IRIBHM), Université Libre de Bruxelles (ULB), Bruxelles, Belgium
| | - Jennifer Pozo
- Institut de Recherche Interdisciplinaire en Biologie Humaine et Moléculaire (IRIBHM), Université Libre de Bruxelles (ULB), Bruxelles, Belgium
- ULB Neuroscience Institute (UNI), Université Libre de Bruxelles (ULB), Bruxelles, Belgium
| | - Virginie Imbault
- Institut de Recherche Interdisciplinaire en Biologie Humaine et Moléculaire (IRIBHM), Université Libre de Bruxelles (ULB), Bruxelles, Belgium
| | - Xavier Bisteau
- Institut de Recherche Interdisciplinaire en Biologie Humaine et Moléculaire (IRIBHM), Université Libre de Bruxelles (ULB), Bruxelles, Belgium
| | - Valérie Wittamer
- Institut de Recherche Interdisciplinaire en Biologie Humaine et Moléculaire (IRIBHM), Université Libre de Bruxelles (ULB), Bruxelles, Belgium
- ULB Neuroscience Institute (UNI), Université Libre de Bruxelles (ULB), Bruxelles, Belgium
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7
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Nielson JA, Davis JM. Roles for Microglia in Cryptococcal Brain Dissemination in the Zebrafish Larva. Microbiol Spectr 2023; 11:e0431522. [PMID: 36719205 PMCID: PMC10100726 DOI: 10.1128/spectrum.04315-22] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Accepted: 12/20/2022] [Indexed: 02/01/2023] Open
Abstract
Cryptococcal infection begins in the lungs, but yeast cells subsequently access the bloodstream, from which they can reach the central nervous system (CNS). The resulting meningoencephalitis is the most common presentation and is very difficult to treat. How this fungus interacts with the blood-brain barrier (BBB) and establishes growth in the brain parenchyma remains a central question in fungal pathogenesis. We and others have developed the zebrafish larva as a model host for cryptococcosis and demonstrated that hematogenous CNS infection is replicated in this model. Here, we have used this model to examine the details of BBB crossing and the events immediately before and after. We have observed multiple mechanisms of BBB crossing and found that microglia, the resident phagocytes of the brain, likely have multiple roles. First, microglia either actively transfer yeast cells across the BBB or take up a significant proportion of them immediately after crossing. Second, microglia are capable of clearing individual cryptococcal cells at a developmental stage before adaptive immune cells have emerged. Third, microglia serve to maintain endothelial integrity, preventing other, phagocyte-independent forms of crossing. These proposed microglial functions during infection in the zebrafish larva generate new hypotheses concerning the establishment and control of cryptococcal meningoencephalitis. IMPORTANCE Cryptococcal meningitis is a fungal infection of the brain and a major cause of death in people with uncontrolled HIV. Infection begins in the lungs but can enter the bloodstream and disseminate to the brain. A structure called the blood-brain barrier must be crossed for the fungus to enter and cause meningitis. Learning how Cryptococcus crosses the blood-brain barrier will be crucial to understanding and possibly preventing brain infection. Using the zebrafish larva as a model host, we show that microglia, the resident phagocytes of the brain, potentially play multiple previously unappreciated roles in cryptococcal infection of the brain. These roles include reinforcing the integrity of the blood-brain barrier, clearing cryptococcal cells after they have crossed, and possibly participating directly in crossing via a previously unknown mechanism.
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Affiliation(s)
- Jacquelyn A. Nielson
- Stead Family Department of Pediatrics, Carver College of Medicine, University of Iowa, Iowa City, USA
| | - J. Muse Davis
- Stead Family Department of Pediatrics, Carver College of Medicine, University of Iowa, Iowa City, USA
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8
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Bruckner JJ, Stednitz SJ, Grice MZ, Zaidan D, Massaquoi MS, Larsch J, Tallafuss A, Guillemin K, Washbourne P, Eisen JS. The microbiota promotes social behavior by modulating microglial remodeling of forebrain neurons. PLoS Biol 2022; 20:e3001838. [PMID: 36318534 PMCID: PMC9624426 DOI: 10.1371/journal.pbio.3001838] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Accepted: 09/19/2022] [Indexed: 11/06/2022] Open
Abstract
Host-associated microbiotas guide the trajectory of developmental programs, and altered microbiota composition is linked to neurodevelopmental conditions such as autism spectrum disorder. Recent work suggests that microbiotas modulate behavioral phenotypes associated with these disorders. We discovered that the zebrafish microbiota is required for normal social behavior and reveal a molecular pathway linking the microbiota, microglial remodeling of neural circuits, and social behavior in this experimentally tractable model vertebrate. Examining neuronal correlates of behavior, we found that the microbiota restrains neurite complexity and targeting of forebrain neurons required for normal social behavior and is necessary for localization of forebrain microglia, brain-resident phagocytes that remodel neuronal arbors. The microbiota also influences microglial molecular functions, including promoting expression of the complement signaling pathway and the synaptic remodeling factor c1q. Several distinct bacterial taxa are individually sufficient for normal microglial and neuronal phenotypes, suggesting that host neuroimmune development is sensitive to a feature common among many bacteria. Our results demonstrate that the microbiota influences zebrafish social behavior by stimulating microglial remodeling of forebrain circuits during early neurodevelopment and suggest pathways for new interventions in multiple neurodevelopmental disorders.
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Affiliation(s)
- Joseph J. Bruckner
- Institute of Neuroscience, Department of Biology, University of Oregon, Eugene, Oregon, United States of America
| | - Sarah J. Stednitz
- Institute of Neuroscience, Department of Biology, University of Oregon, Eugene, Oregon, United States of America
| | - Max Z. Grice
- Institute of Neuroscience, Department of Biology, University of Oregon, Eugene, Oregon, United States of America
| | - Dana Zaidan
- Institute of Neuroscience, Department of Biology, University of Oregon, Eugene, Oregon, United States of America
| | - Michelle S. Massaquoi
- Institute of Molecular Biology, Department of Biology, University of Oregon, Eugene, Oregon, United States of America
| | - Johannes Larsch
- Department Genes-Circuits-Behavior, Max Planck Institute of Neurobiology, Martinsried, Germany
| | - Alexandra Tallafuss
- Institute of Neuroscience, Department of Biology, University of Oregon, Eugene, Oregon, United States of America
| | - Karen Guillemin
- Institute of Molecular Biology, Department of Biology, University of Oregon, Eugene, Oregon, United States of America
- Humans and the Microbiome Program, CIFAR, Toronto, Ontario, Canada
| | - Philip Washbourne
- Institute of Neuroscience, Department of Biology, University of Oregon, Eugene, Oregon, United States of America
| | - Judith S. Eisen
- Institute of Neuroscience, Department of Biology, University of Oregon, Eugene, Oregon, United States of America
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9
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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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10
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Zou D, Qin J, Hu W, Wei Z, Zhan Y, He Y, Zhao C, Li L. Macrophages Rapidly Seal off the Punctured Zebrafish Larval Brain through a Vital Honeycomb Network Structure. Int J Mol Sci 2022; 23:ijms231810551. [PMID: 36142462 PMCID: PMC9503817 DOI: 10.3390/ijms231810551] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 08/30/2022] [Accepted: 09/07/2022] [Indexed: 11/26/2022] Open
Abstract
There is accumulating evidence that macrophages play additional important roles in tissue damage besides their typical phagocytosis. Although the aggregation of macrophages on injured sites has long been observed, few researchers have focused on the role of the overall structure of macrophage aggregation. In this study, we developed a standardized traumatic brain injury (TBI) model in zebrafish larvae to mimic edema and brain tissue spillage symptoms after severe brain trauma. Using time-lapse imaging, we showed that macrophages/microglia in zebrafish larvae responded rapidly and dominated the surface of injured tissue, forming a meaningful honeycomb network structure through their compact aggregation and connection. Disrupting this structure led to fatal edema-like symptoms with severe loss of brain tissue. Using the RNA-Seq, together with the manipulation of in vitro cell lines, we found that collagen IV was indispensable to the formation of honeycomb network structures. Our study thus revealed a novel perspective regarding macrophages forming a protective compact structure with collagen IV. This honeycomb network structure acted as a physical barrier to prevent tissue loss and maintain brain homeostasis after TBI. This study may provide new evidence of macrophages’ function for the rapid protection of brain tissue after brain injury.
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Affiliation(s)
- Dandan Zou
- Key Laboratory of Freshwater Fish Reproduction and Development, Ministry of Education, Institute of Developmental Biology and Regenerative Medicine, Southwest University, Beibei, Chongqing 400715, China
| | - Jie Qin
- Key Laboratory of Freshwater Fish Reproduction and Development, Ministry of Education, Institute of Developmental Biology and Regenerative Medicine, Southwest University, Beibei, Chongqing 400715, China
| | - Wenlong Hu
- Key Laboratory of Freshwater Fish Reproduction and Development, Ministry of Education, Institute of Developmental Biology and Regenerative Medicine, Southwest University, Beibei, Chongqing 400715, China
| | - Zongfang Wei
- Key Laboratory of Freshwater Fish Reproduction and Development, Ministry of Education, Institute of Developmental Biology and Regenerative Medicine, Southwest University, Beibei, Chongqing 400715, China
| | - Yandong Zhan
- Key Laboratory of Freshwater Fish Reproduction and Development, Ministry of Education, Institute of Developmental Biology and Regenerative Medicine, Southwest University, Beibei, Chongqing 400715, China
| | - Yuepeng He
- Key Laboratory of Freshwater Fish Reproduction and Development, Ministry of Education, Institute of Developmental Biology and Regenerative Medicine, Southwest University, Beibei, Chongqing 400715, China
| | - Congjian Zhao
- Chongqing Engineering Research Center of Medical Electronics and Information Technology, School of Biomedical Engineering and Informatics, Chongqing University of Posts and Telecommunications, Chongqing 400065, China
| | - Li Li
- Research Center of Stem Cells and Ageing, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 400714, China
- Correspondence:
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11
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Mazzolini J, Le Clerc S, Morisse G, Coulonges C, Zagury J, Sieger D. Wasl is crucial to maintain microglial core activities during glioblastoma initiation stages. Glia 2022; 70:1027-1051. [PMID: 35194846 PMCID: PMC9306864 DOI: 10.1002/glia.24154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 01/19/2022] [Accepted: 01/21/2022] [Indexed: 11/28/2022]
Abstract
Microglia actively promotes the growth of high-grade gliomas. Within the glioma microenvironment an amoeboid microglial morphology has been observed, however the underlying causes and the related impact on microglia functions and their tumor promoting activities is unclear. Using the advantages of the larval zebrafish model, we identified the underlying mechanism and show that microglial morphology and functions are already impaired during glioma initiation stages. The presence of pre-neoplastic HRasV12 expressing cells induces an amoeboid morphology of microglia, increases microglial numbers and decreases their motility and phagocytic activity. RNA sequencing analysis revealed lower expression levels of the actin nucleation promoting factor wasla in microglia. Importantly, a microglia specific rescue of wasla expression restores microglial morphology and functions. This results in increased phagocytosis of pre-neoplastic cells and slows down tumor progression. In conclusion, we identified a mechanism that de-activates core microglial functions within the emerging glioma microenvironment. Restoration of this mechanism might provide a way to impair glioma growth.
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Affiliation(s)
- Julie Mazzolini
- Centre for Discovery Brain SciencesUniversity of EdinburghEdinburghUK
| | - Sigrid Le Clerc
- Laboratoire GBCM, EA7528, Conservatoire National des Arts et MétiersHESAM UniversitéParisFrance
| | - Gregoire Morisse
- Centre for Discovery Brain SciencesUniversity of EdinburghEdinburghUK
| | - Cédric Coulonges
- Laboratoire GBCM, EA7528, Conservatoire National des Arts et MétiersHESAM UniversitéParisFrance
| | - Jean‐François Zagury
- Laboratoire GBCM, EA7528, Conservatoire National des Arts et MétiersHESAM UniversitéParisFrance
| | - Dirk Sieger
- Centre for Discovery Brain SciencesUniversity of EdinburghEdinburghUK
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12
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Kwon V, Cai P, Dixon CT, Hamlin V, Spencer CG, Rojas AM, Hamilton M, Shiau CE. Peripheral NOD-like receptor deficient inflammatory macrophages trigger neutrophil infiltration into the brain disrupting daytime locomotion. Commun Biol 2022; 5:464. [PMID: 35577844 PMCID: PMC9110401 DOI: 10.1038/s42003-022-03410-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Accepted: 04/25/2022] [Indexed: 11/09/2022] Open
Abstract
Inflammation is known to disrupt normal behavior, yet the underlying neuroimmune interactions remain elusive. Here, we investigated whether inappropriate macrophage-evoked inflammation alters CNS control of daily-life animal locomotion using a set of zebrafish mutants selected for specific macrophage dysfunction and microglia deficiency. Large-scale genetic and computational analyses revealed that NOD-like receptor nlrc3l mutants are capable of normal motility and visuomotor response, but preferentially swim less in the daytime, suggesting possible low motivation rather than physical impairment. Examining their brain activities and structures implicates impaired dopaminergic descending circuits, where neutrophils abnormally infiltrate. Furthermore, neutrophil depletion recovered daytime locomotion. Restoring wild-type macrophages reversed behavioral and neutrophil aberrations, while three other microglia-lacking mutants failed to phenocopy nlrc3l mutants. Overall, we reveal how peripheral inflammatory macrophages with elevated pro-inflammatory cues (including il1β, tnfα, cxcl8a) in the absence of microglia co-opt neutrophils to infiltrate the brain, thereby potentially enabling local circuitry modulation affecting daytime locomotion.
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Affiliation(s)
- Victoria Kwon
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Peiwen Cai
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Cameron T Dixon
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Victoria Hamlin
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Caroline G Spencer
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Alison M Rojas
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Matthew Hamilton
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Celia E Shiau
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA. .,Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
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13
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Ranawat N, Masai I. Mechanisms underlying microglial colonization of developing neural retina in zebrafish. eLife 2021; 10:70550. [PMID: 34872632 PMCID: PMC8651297 DOI: 10.7554/elife.70550] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Accepted: 11/02/2021] [Indexed: 12/13/2022] Open
Abstract
Microglia are brain-resident macrophages that function as the first line of defense in brain. Embryonic microglial precursors originate in peripheral mesoderm and migrate into the brain during development. However, the mechanism by which they colonize the brain is incompletely understood. The retina is one of the first brain regions to accommodate microglia. In zebrafish, embryonic microglial precursors use intraocular hyaloid blood vessels as a pathway to migrate into the optic cup via the choroid fissure. Once retinal progenitor cells exit the cell cycle, microglial precursors associated with hyaloid blood vessels start to infiltrate the retina preferentially through neurogenic regions, suggesting that colonization of retinal tissue depends upon the neurogenic state. Along with blood vessels and retinal neurogenesis, IL34 also participates in microglial precursor colonization of the retina. Altogether, CSF receptor signaling, blood vessels, and neuronal differentiation function as cues to create an essential path for microglial migration into developing retina. The immune system is comprised of many different cells which protect our bodies from infection and other illnesses. The brain contains its own population of immune cells called microglia. Unlike neurons, these cells form outside the brain during development. They then travel to the brain and colonize specific regions like the retina, the light-sensing part of the eye in vertebrates. It is poorly understood how newly formed microglia migrate to the retina and whether their entry depends on the developmental state of nerve cells (also known as neurons) in this region. To help answer these questions, Ranawat and Masai attached fluorescent labels that can be seen under a microscope to microglia in the embryos of zebrafish. Developing zebrafish are transparent, making it easy to trace the fluorescent microglia as they travel to the retina and insert themselves among its neurons. Ranawat and Masai found that blood vessels around the retina act as a pathway that microglia move along. Once they reach the retina, the microglia remain attached and only enter the retina at sites where brain cells are starting to mature in to adult neurons. Further experiments showed that microglia fail to infiltrate and colonize the retina when blood vessels are damaged or neuron maturation is blocked. These findings reveal some of the key elements that guide microglia to the retina during development. However, further work is needed to establish the molecular and biochemical processes that allow microglia to attach to blood vessels and detect when cells in the retina are starting to mature.
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Affiliation(s)
- Nishtha Ranawat
- Developmental Neurobiology Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Japan
| | - Ichiro Masai
- Developmental Neurobiology Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Japan
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14
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Silva NJ, Dorman LC, Vainchtein ID, Horneck NC, Molofsky AV. In situ and transcriptomic identification of microglia in synapse-rich regions of the developing zebrafish brain. Nat Commun 2021; 12:5916. [PMID: 34625548 PMCID: PMC8501082 DOI: 10.1038/s41467-021-26206-x] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 09/16/2021] [Indexed: 01/02/2023] Open
Abstract
Microglia are brain resident macrophages that play vital roles in central nervous system (CNS) development, homeostasis, and pathology. Microglia both remodel synapses and engulf apoptotic cell corpses during development, but whether unique molecular programs regulate these distinct phagocytic functions is unknown. Here we identify a molecularly distinct microglial subset in the synapse rich regions of the zebrafish (Danio rerio) brain. We found that ramified microglia increased in synaptic regions of the midbrain and hindbrain between 7 and 28 days post fertilization. In contrast, microglia in the optic tectum were ameboid and clustered around neurogenic zones. Using single-cell mRNA sequencing combined with metadata from regional bulk sequencing, we identified synaptic-region associated microglia (SAMs) that were highly enriched in the hindbrain and expressed multiple candidate synapse modulating genes, including genes in the complement pathway. In contrast, neurogenic associated microglia (NAMs) were enriched in the optic tectum, had active cathepsin activity, and preferentially engulfed neuronal corpses. These data reveal that molecularly distinct phagocytic programs mediate synaptic remodeling and cell engulfment, and establish the zebrafish hindbrain as a model for investigating microglial-synapse interactions. Microglia remodel synapses and engulf apoptotic cells. The molecular program underlying these distinct functions are unclear. Here, the authors identify distinct microglial subsets associated with synaptic vs. neurogenic regions of the developing zebrafish brain.
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Affiliation(s)
- Nicholas J Silva
- Department of Psychiatry and Behavioral Sciences/Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, USA
| | - Leah C Dorman
- Department of Psychiatry and Behavioral Sciences/Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, USA.,Neuroscience Graduate Program, University of California, San Francisco, San Francisco, CA, USA
| | - Ilia D Vainchtein
- Department of Psychiatry and Behavioral Sciences/Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, USA
| | - Nadine C Horneck
- Department of Psychiatry and Behavioral Sciences/Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, USA
| | - Anna V Molofsky
- Department of Psychiatry and Behavioral Sciences/Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, USA. .,Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, San Francisco, CA, USA.
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15
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Solek CM, Farooqi NAI, Brake N, Kesner P, Schohl A, Antel JP, Ruthazer ES. Early Inflammation Dysregulates Neuronal Circuit Formation In Vivo via Upregulation of IL-1β. J Neurosci 2021; 41:6353-6366. [PMID: 34103360 PMCID: PMC8287996 DOI: 10.1523/jneurosci.2159-20.2021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Revised: 04/04/2021] [Accepted: 05/29/2021] [Indexed: 12/18/2022] Open
Abstract
Neuroimmune interaction during development is strongly implicated in the pathogenesis of neurodevelopmental disorders, but the mechanisms that cause neuronal circuit dysregulation are not well understood. We performed in vivo imaging of the developing retinotectal system in the larval zebrafish to characterize the effects of immune system activation on refinement of an archetypal sensory processing circuit. Acute inflammatory insult induced hyperdynamic remodeling of developing retinal axons in larval fish and increased axon arbor elaboration over days. Using calcium imaging in GCaMP6s transgenic fish, we showed that these morphologic changes were accompanied by a shift toward decreased visual acuity in tectal cells. This finding was supported by poorer performance in a visually guided behavioral task. We further found that the pro-inflammatory cytokine, interleukin-1β (IL-1β), is upregulated by the inflammatory insult, and that downregulation of IL-1β abrogated the effects of inflammation on axonal dynamics and growth. Moreover, baseline branching of the retinal ganglion cell arbors in IL-1β morphant animals was significantly different from that in control larvae, and their performance in a predation assay was impaired, indicating a role for this cytokine in normal neuronal development. This work establishes a simple and powerful non-mammalian model of developmental immune activation and demonstrates a role for IL-1β in mediating the pathologic effects of inflammation on neuronal circuit development.SIGNIFICANCE STATEMENT Maternal immune activation can increase the risk of neurodevelopmental disorders in offspring; however, the mechanisms involved are not fully understood. Using a non-mammalian vertebrate model of developmental immune activation, we show that even brief activation of inflammatory pathways has immediate and long-term effects on the arborization of axons, and that these morphologic changes have functional and behavioral consequences. Finally, we show that the pro-inflammatory cytokine IL-1β plays an essential role in both the effects of inflammation on circuit formation and normal axonal development. Our data add to a growing body of evidence supporting epidemiological studies linking immune activation to neurodevelopmental disorders, and help shed light on the molecular and cellular processes that contribute to the etiology of these disorders.
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Affiliation(s)
- Cynthia M Solek
- Department of Neurology and Neurosurgery, Montreal Neurological Institute-Hospital, McGill University, Montreal, Quebec H3A 2B4, Canada
| | - Nasr A I Farooqi
- Department of Neurology and Neurosurgery, Montreal Neurological Institute-Hospital, McGill University, Montreal, Quebec H3A 2B4, Canada
| | - Niklas Brake
- Department of Neurology and Neurosurgery, Montreal Neurological Institute-Hospital, McGill University, Montreal, Quebec H3A 2B4, Canada
| | - Philip Kesner
- Department of Neurology and Neurosurgery, Montreal Neurological Institute-Hospital, McGill University, Montreal, Quebec H3A 2B4, Canada
| | - Anne Schohl
- Department of Neurology and Neurosurgery, Montreal Neurological Institute-Hospital, McGill University, Montreal, Quebec H3A 2B4, Canada
| | - Jack P Antel
- Department of Neurology and Neurosurgery, Montreal Neurological Institute-Hospital, McGill University, Montreal, Quebec H3A 2B4, Canada
| | - Edward S Ruthazer
- Department of Neurology and Neurosurgery, Montreal Neurological Institute-Hospital, McGill University, Montreal, Quebec H3A 2B4, Canada
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16
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Paasila PJ, Fok SYY, Flores‐Rodriguez N, Sajjan S, Svahn AJ, Dennis CV, Holsinger RMD, Kril JJ, Becker TS, Banati RB, Sutherland GT, Graeber MB. Ground state depletion microscopy as a tool for studying microglia-synapse interactions. J Neurosci Res 2021; 99:1515-1532. [PMID: 33682204 PMCID: PMC8251743 DOI: 10.1002/jnr.24819] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 02/02/2021] [Accepted: 02/06/2021] [Indexed: 01/09/2023]
Abstract
Ground state depletion followed by individual molecule return microscopy (GSDIM) has been used in the past to study the nanoscale distribution of protein co-localization in living cells. We now demonstrate the successful application of GSDIM to archival human brain tissue sections including from Alzheimer's disease cases as well as experimental tissue samples from mouse and zebrafish larvae. Presynaptic terminals and microglia and their cell processes were visualized at a resolution beyond diffraction-limited light microscopy, allowing clearer insights into their interactions in situ. The procedure described here offers time and cost savings compared to electron microscopy and opens the spectrum of molecular imaging using antibodies and super-resolution microscopy to the analysis of routine formalin-fixed paraffin sections of archival human brain. The investigation of microglia-synapse interactions in dementia will be of special interest in this context.
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Affiliation(s)
- Patrick Jarmo Paasila
- Faculty of Medicine and HealthCharles Perkins Centre and School of Medical SciencesThe University of SydneyCamperdownNSWAustralia
| | - Sandra Y. Y. Fok
- Biomedical Imaging FacilityMark Wainwright Analytical CentreUniversity of New South Wales SydneyKensingtonNSWAustralia
| | - Neftali Flores‐Rodriguez
- Charles Perkins CentreSydney Microscopy and MicroanalysisThe University of SydneyCamperdownNSWAustralia
| | - Sujata Sajjan
- Faculty of Medicine and HealthBrain and Mind CentreThe University of SydneyCamperdownNSWAustralia
| | - Adam J. Svahn
- Faculty of Medicine and HealthBrain and Mind CentreThe University of SydneyCamperdownNSWAustralia
| | - Claude V. Dennis
- Faculty of Medicine and HealthCharles Perkins Centre and School of Medical SciencesThe University of SydneyCamperdownNSWAustralia
| | - R. M. Damian Holsinger
- Faculty of Medicine and HealthBrain and Mind CentreThe University of SydneyCamperdownNSWAustralia
| | - Jillian J. Kril
- Faculty of Medicine and HealthCharles Perkins Centre and School of Medical SciencesThe University of SydneyCamperdownNSWAustralia
| | - Thomas S. Becker
- Faculty of Medicine and HealthBrain and Mind CentreThe University of SydneyCamperdownNSWAustralia
| | - Richard B. Banati
- Faculty of Medicine and HealthBrain and Mind CentreThe University of SydneyCamperdownNSWAustralia
- Life SciencesAustralian Nuclear Science and Technology OrganisationKirraweeNSWAustralia
| | - Greg T. Sutherland
- Faculty of Medicine and HealthCharles Perkins Centre and School of Medical SciencesThe University of SydneyCamperdownNSWAustralia
| | - Manuel B. Graeber
- Faculty of Medicine and HealthBrain and Mind CentreThe University of SydneyCamperdownNSWAustralia
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17
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Sharma K, Bisht K, Eyo UB. A Comparative Biology of Microglia Across Species. Front Cell Dev Biol 2021; 9:652748. [PMID: 33869210 PMCID: PMC8047420 DOI: 10.3389/fcell.2021.652748] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Accepted: 03/10/2021] [Indexed: 12/26/2022] Open
Abstract
Microglia are unique brain-resident, myeloid cells. They have received growing interest for their implication in an increasing number of neurodevelopmental, acute injury, and neurodegenerative disorders of the central nervous system (CNS). Fate-mapping studies establish microglial ontogeny from the periphery during development, while recent transcriptomic studies highlight microglial identity as distinct from other CNS cells and peripheral myeloid cells. This evidence for a unique microglial ontogeny and identity raises questions regarding their identity and functions across species. This review will examine the available evidence for microglia in invertebrate and vertebrate species to clarify similarities and differences in microglial identity, ontogeny, and physiology across species. This discussion highlights conserved and divergent microglial properties through evolution. Finally, we suggest several interesting research directions from an evolutionary perspective to adequately understand the significance of microglia emergence. A proper appreciation of microglia from this perspective could inform the development of specific therapies geared at targeting microglia in various pathologies.
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Affiliation(s)
- Kaushik Sharma
- Center for Brain Immunology and Glia, University of Virginia, Charlottesville, VA, United States.,Department of Neuroscience, University of Virginia, Charlottesville, VA, United States
| | - Kanchan Bisht
- Center for Brain Immunology and Glia, University of Virginia, Charlottesville, VA, United States.,Department of Neuroscience, University of Virginia, Charlottesville, VA, United States
| | - Ukpong B Eyo
- Center for Brain Immunology and Glia, University of Virginia, Charlottesville, VA, United States.,Department of Neuroscience, University of Virginia, Charlottesville, VA, United States
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18
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Lim TKY, Ruthazer ES. Microglial trogocytosis and the complement system regulate axonal pruning in vivo. eLife 2021; 10:e62167. [PMID: 33724186 PMCID: PMC7963485 DOI: 10.7554/elife.62167] [Citation(s) in RCA: 56] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2020] [Accepted: 02/28/2021] [Indexed: 12/14/2022] Open
Abstract
Partial phagocytosis-called trogocytosis-of axons by microglia has been documented in ex vivo preparations but has not been directly observed in vivo. The mechanisms that modulate microglial trogocytosis of axons and its function in neural circuit development remain poorly understood. Here, we directly observe axon trogocytosis by microglia in vivo in the developing Xenopus laevis retinotectal circuit. We show that microglia regulate pruning of retinal ganglion cell axons and are important for proper behavioral response to dark and bright looming stimuli. Using bioinformatics, we identify amphibian regulator of complement activation 3, a homolog of human CD46, as a neuronally expressed synapse-associated complement inhibitory molecule that inhibits trogocytosis and axonal pruning. Using a membrane-bound complement C3 fusion protein, we demonstrate that enhancing complement activity enhances axonal pruning. Our results support the model that microglia remodel axons via trogocytosis and that neurons can control this process through expression of complement inhibitory proteins.
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Affiliation(s)
- Tony KY Lim
- Department of Neurology & Neurosurgery, Montreal Neurological Institute-Hospital, McGill UniversityMontrealCanada
| | - Edward S Ruthazer
- Department of Neurology & Neurosurgery, Montreal Neurological Institute-Hospital, McGill UniversityMontrealCanada
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19
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Warchol ME, Schrader A, Sheets L. Macrophages Respond Rapidly to Ototoxic Injury of Lateral Line Hair Cells but Are Not Required for Hair Cell Regeneration. Front Cell Neurosci 2021; 14:613246. [PMID: 33488362 PMCID: PMC7820375 DOI: 10.3389/fncel.2020.613246] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Accepted: 12/03/2020] [Indexed: 01/01/2023] Open
Abstract
The sensory organs of the inner ear contain resident populations of macrophages, which are recruited to sites of cellular injury. Such macrophages are known to phagocytose the debris of dying cells but the full role of macrophages in otic pathology is not understood. Lateral line neuromasts of zebrafish contain hair cells that are nearly identical to those in the inner ear, and the optical clarity of larval zebrafish permits direct imaging of cellular interactions. In this study, we used larval zebrafish to characterize the response of macrophages to ototoxic injury of lateral line hair cells. Macrophages migrated into neuromasts within 20 min of exposure to the ototoxic antibiotic neomycin. The number of macrophages in the near vicinity of injured neuromasts was similar to that observed near uninjured neuromasts, suggesting that this early inflammatory response was mediated by "local" macrophages. Upon entering injured neuromasts, macrophages actively phagocytosed hair cell debris. The injury-evoked migration of macrophages was significantly reduced by inhibition of Src-family kinases. Using chemical-genetic ablation of macrophages before the ototoxic injury, we also examined whether macrophages were essential for the initiation of hair cell regeneration. Results revealed only minor differences in hair cell recovery in macrophage-depleted vs. control fish, suggesting that macrophages are not essential for the regeneration of lateral line hair cells.
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Affiliation(s)
- Mark E. Warchol
- Department of Otolaryngology, Washington University School of Medicine, St. Louis, MO, United States
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO, United States
| | - Angela Schrader
- Department of Otolaryngology, Washington University School of Medicine, St. Louis, MO, United States
| | - Lavinia Sheets
- Department of Otolaryngology, Washington University School of Medicine, St. Louis, MO, United States
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO, United States
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20
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Choi KM, Cho DH, Joo MS, Choi HS, Kim MS, Han HJ, Cho MY, Hwang SD, Kim DH, Park CI. Functional characterization and gene expression profile of perforin-2 in starry flounder (Platichthys stellatus). FISH & SHELLFISH IMMUNOLOGY 2020; 107:511-518. [PMID: 33217563 DOI: 10.1016/j.fsi.2020.11.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 10/26/2020] [Accepted: 11/09/2020] [Indexed: 06/11/2023]
Abstract
The membrane attack complex/perforin (MACPF) superfamily consists of multifunctional proteins that form pores on the membrane surface of microorganisms to induce their death and have various immune-related functions. PFN2 is a perforin-like protein with an MACPF domain, and humans with deficient PFN2 levels have increased susceptibility to bacterial infection, which can lead to fatal consequences for some patients. Therefore, in this study, we confirmed the antimicrobial function of PFN2 in starry flounder (Platichthys stellatus). The molecular properties were confirmed based on the verified amino acid sequence of PsPFN2. In addition, the expression characteristics of tissue-specific and pathogen-specific PsPFN2 mRNA were also confirmed. The recombinant protein was produced using Escherichia coli, and the antimicrobial activity was then confirmed. The coding sequence of PFN2 (PsPFN2) in P. stellatus consists of 710 residues. The MACPF domain was conserved throughout evolution, as shown by multiple sequence alignment and phylogenetic analysis. PsPFN2 mRNA is abundantly distributed in immune-related organs such as the spleen and gills of healthy starry flounder, and significant expression changes were confirmed after artificial infection by bacteria or viruses. We cloned the MACPF domain region of PFN2 to produce a recombinant protein (rPFN2) and confirmed its antibacterial effect against a wide range of bacterial species and the parasite (Miamiensis avidus).
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Affiliation(s)
- Kwang-Min Choi
- Department of Marine Biology & Aquaculture, College of Marine Science, Gyeongsang National University, 455, Tongyeong, 650-160, Republic of Korea
| | - Dong-Hee Cho
- Department of Marine Biology & Aquaculture, College of Marine Science, Gyeongsang National University, 455, Tongyeong, 650-160, Republic of Korea
| | - Min-Soo Joo
- Department of Marine Biology & Aquaculture, College of Marine Science, Gyeongsang National University, 455, Tongyeong, 650-160, Republic of Korea
| | - Hye-Sung Choi
- Pathology Research Division, National Institute of Fisheries Science, 408-1 Sirang-ri, Gijang-up, Gijang-gun, Busan, 46083, Republic of Korea
| | - Myoung Sug Kim
- Pathology Research Division, National Institute of Fisheries Science, 408-1 Sirang-ri, Gijang-up, Gijang-gun, Busan, 46083, Republic of Korea
| | - Hyun-Ja Han
- Pathology Research Division, National Institute of Fisheries Science, 408-1 Sirang-ri, Gijang-up, Gijang-gun, Busan, 46083, Republic of Korea
| | - Mi Young Cho
- Pathology Research Division, National Institute of Fisheries Science, 408-1 Sirang-ri, Gijang-up, Gijang-gun, Busan, 46083, Republic of Korea
| | - Seong Don Hwang
- Pathology Research Division, National Institute of Fisheries Science, 408-1 Sirang-ri, Gijang-up, Gijang-gun, Busan, 46083, Republic of Korea
| | - Do-Hyung Kim
- Department of Aquatic Life Medicine, College of Fisheries Science, Pukyong National University, 45, Yongso-ro, Nam-Gu., Busan, Republic of Korea.
| | - Chan-Il Park
- Department of Marine Biology & Aquaculture, College of Marine Science, Gyeongsang National University, 455, Tongyeong, 650-160, Republic of Korea.
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21
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Demy DL, Carrère M, Noche R, Tauzin M, Le Bris M, Baek C, Leshchiner I, Goessling W, Herbomel P. The cationic amino acid exporter Slc7a7 is induced and vital in zebrafish tissue macrophages with sustained efferocytic activity. J Cell Sci 2020; 133:jcs249037. [PMID: 32973110 DOI: 10.1242/jcs.249037] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Accepted: 09/09/2020] [Indexed: 01/02/2023] Open
Abstract
Most tissues harbor a substantial population of resident macrophages. Here, we elucidate a functional link between the Slc7a7 cationic amino acid transporter and tissue macrophages. We identified a mutant zebrafish devoid of microglia due to a mutation in the slc7a7 gene. We found that in Slc7a7-deficient larvae, macrophages do enter the retina and brain to become microglia, but then die during the developmental wave of neuronal apoptosis, which triggers intense efferocytic work from them. A similar macrophage demise occurs in other tissues, at stages where macrophages have to engulf many cell corpses, whether due to developmental or experimentally triggered cell death. We found that Slc7a7 is the main cationic amino acid transporter expressed in macrophages of zebrafish larvae, and that its expression is induced in tissue macrophages within 1-2 h upon efferocytosis. Our data indicate that Slc7a7 is vital not only for microglia but also for any steadily efferocytic tissue macrophages, and that slc7a7 gene induction is one of the adaptive responses that allow them to cope with the catabolism of numerous dead cells without compromising their own viability.
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Affiliation(s)
- Doris Lou Demy
- Institut Pasteur, Department of Developmental & Stem Cell Biology, 75015 Paris, France
- CNRS, UMR3738, 75015 Paris, France
| | - Mireille Carrère
- Institut Pasteur, Department of Developmental & Stem Cell Biology, 75015 Paris, France
- CNRS, UMR3738, 75015 Paris, France
| | - Ramil Noche
- Institut Pasteur, Department of Developmental & Stem Cell Biology, 75015 Paris, France
- CNRS, UMR3738, 75015 Paris, France
| | - Muriel Tauzin
- Institut Pasteur, Department of Developmental & Stem Cell Biology, 75015 Paris, France
- CNRS, UMR3738, 75015 Paris, France
| | - Marion Le Bris
- Institut Pasteur, Department of Developmental & Stem Cell Biology, 75015 Paris, France
- CNRS, UMR3738, 75015 Paris, France
| | - Chooyoung Baek
- Institut Pasteur, Department of Developmental & Stem Cell Biology, 75015 Paris, France
- CNRS, UMR3738, 75015 Paris, France
| | | | - Wolfram Goessling
- Division of Gastroenterology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Philippe Herbomel
- Institut Pasteur, Department of Developmental & Stem Cell Biology, 75015 Paris, France
- CNRS, UMR3738, 75015 Paris, France
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22
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Var SR, Byrd-Jacobs CA. Role of Macrophages and Microglia in Zebrafish Regeneration. Int J Mol Sci 2020; 21:E4768. [PMID: 32635596 PMCID: PMC7369716 DOI: 10.3390/ijms21134768] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 07/02/2020] [Accepted: 07/03/2020] [Indexed: 12/11/2022] Open
Abstract
Currently, there is no treatment for recovery of human nerve function after damage to the central nervous system (CNS), and there are limited regenerative capabilities in the peripheral nervous system. Since fish are known for their regenerative abilities, understanding how these species modulate inflammatory processes following injury has potential translational importance for recovery from damage and disease. Many diseases and injuries involve the activation of innate immune cells to clear damaged cells. The resident immune cells of the CNS are microglia, the primary cells that respond to infection and injury, and their peripheral counterparts, macrophages. These cells serve as key modulators of development and plasticity and have been shown to be important in the repair and regeneration of structure and function after injury. Zebrafish are an emerging model for studying macrophages in regeneration after injury and microglia in neurodegenerative disorders such as Parkinson's disease and Alzheimer's disease. These fish possess a high degree of neuroanatomical, neurochemical, and emotional/social behavioral resemblance with humans, serving as an ideal simulator for many pathologies. This review explores literature on macrophage and microglial involvement in facilitating regeneration. Understanding innate immune cell behavior following damage may help to develop novel methods for treating toxic and chronic inflammatory processes that are seen in trauma and disease.
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23
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Weber T, Schlotawa L, Dosch R, Hamilton N, Kaiser J, Schiller S, Wenske B, Gärtner J, Henneke M. Zebrafish disease model of human RNASET2-deficient cystic leukoencephalopathy displays abnormalities in early microglia. Biol Open 2020; 9:bio049239. [PMID: 32295832 PMCID: PMC7225086 DOI: 10.1242/bio.049239] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Accepted: 04/02/2020] [Indexed: 12/14/2022] Open
Abstract
Human infantile-onset RNASET2-deficient cystic leukoencephalopathy is a Mendelian mimic of in utero cytomegalovirus brain infection with prenatally developing inflammatory brain lesions. We used an RNASET2-deficient zebrafish model to elucidate the underlying disease mechanisms. Mutant and wild-type zebrafish larvae brain development between 2 and 5 days post fertilization (dpf) was examined by confocal live imaging in fluorescent reporter lines of the major types of brain cells. In contrast to wild-type brains, RNASET2-deficient larvae displayed increased numbers of microglia with altered morphology, often containing inclusions of neurons. Furthermore, lysosomes within distinct populations of the myeloid cell lineage including microglia showed increased lysosomal staining. Neurons and oligodendrocyte precursor cells remained unaffected. This study provides a first look into the prenatal onset pathomechanisms of human RNASET2-deficient leukoencephalopathy, linking this inborn lysosomal disease to the innate immune system and other immune-related childhood encephalopathies like Aicardi-Goutières syndrome (AGS).
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Affiliation(s)
- Thomas Weber
- Department of Pediatrics and Adolescent Medicine, University Medical Center Goettingen, Robert- Koch- Str. 40, 37075 Goettingen, Germany
| | - Lars Schlotawa
- Department of Pediatrics and Adolescent Medicine, University Medical Center Goettingen, Robert- Koch- Str. 40, 37075 Goettingen, Germany
| | - Roland Dosch
- Department of Human Genetics, University Medical Center Goettingen, Justus-von-Liebig-Weg 11, 37077 Goettingen, Germany
| | - Noémie Hamilton
- The Bateson Centre, University of Sheffield, Firth Court D31, Sheffield S10 2PT, United Kingdom
| | - Jens Kaiser
- Department of Pediatrics and Adolescent Medicine, University Medical Center Goettingen, Robert- Koch- Str. 40, 37075 Goettingen, Germany
| | - Stina Schiller
- Department of Pediatrics and Adolescent Medicine, University Medical Center Goettingen, Robert- Koch- Str. 40, 37075 Goettingen, Germany
| | - Britta Wenske
- Department of Haematology and Oncology, University Medical Center Goettingen, Robert- Koch- Str. 40, 37075 Goettingen, Germany
| | - Jutta Gärtner
- Department of Pediatrics and Adolescent Medicine, University Medical Center Goettingen, Robert- Koch- Str. 40, 37075 Goettingen, Germany
| | - Marco Henneke
- Department of Pediatrics and Adolescent Medicine, University Medical Center Goettingen, Robert- Koch- Str. 40, 37075 Goettingen, Germany
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24
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Blume ZI, Lambert JM, Lovel AG, Mitchell DM. Microglia in the developing retina couple phagocytosis with the progression of apoptosis via P2RY12 signaling. Dev Dyn 2020; 249:723-740. [PMID: 32072708 DOI: 10.1002/dvdy.163] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Revised: 12/30/2019] [Accepted: 02/07/2020] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Microglia colonize the developing vertebrate central nervous system coincident with the detection of developmental apoptosis. Our understanding of apoptosis in intact tissue in relation to microglial clearance of dying cells is largely based on fixed samples, which is limiting given that microglia are highly motile and mobile phagocytes. Here, we used a system of microglial depletion and in vivo real-time imaging in zebrafish to directly address microglial phagocytosis of apoptotic cells during normal retinal development, the relative timing of phagocytosis in relation to apoptotic progression, and the contribution of P2RY12 signaling to this process. RESULTS The depletion of microglia resulted in accumulation of numerous apoptotic cells in the retina. Real-time imaging revealed precise timing of microglial engulfment with the progression of apoptosis, and dynamic movement and displacement of engulfed apoptotic cells. Inhibition of P2RY12 signaling delayed microglial clearance of apoptotic cells. CONCLUSIONS Microglial engulfment of dying cells is coincident with apoptotic progression and requires P2RY12 signaling, indicating that microglial P2RY12 signaling is shared between development and injury response. Our work provides important in vivo insight into the dynamics of apoptotic cell clearance in the developing vertebrate retina and provides a basis to understand microglial phagocytic behavior in health and disease.
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Affiliation(s)
- Zachary I Blume
- Biological Sciences, University of Idaho, Moscow, Idaho, USA
| | - Jared M Lambert
- Biological Sciences, University of Idaho, Moscow, Idaho, USA
| | - Anna G Lovel
- Biological Sciences, University of Idaho, Moscow, Idaho, USA
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25
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Mazzolini J, Le Clerc S, Morisse G, Coulonges C, Kuil LE, van Ham TJ, Zagury J, Sieger D. Gene expression profiling reveals a conserved microglia signature in larval zebrafish. Glia 2020; 68:298-315. [PMID: 31508850 PMCID: PMC6916425 DOI: 10.1002/glia.23717] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Revised: 08/21/2019] [Accepted: 08/22/2019] [Indexed: 12/23/2022]
Abstract
Microglia are the resident macrophages of the brain. Over the past decade, our understanding of the function of these cells has significantly improved. Microglia do not only play important roles in the healthy brain but are involved in almost every brain pathology. Gene expression profiling allowed to distinguish microglia from other macrophages and revealed that the full microglia signature can only be observed in vivo. Thus, animal models are irreplaceable to understand the function of these cells. One of the popular models to study microglia is the zebrafish larva. Due to their optical transparency and genetic accessibility, zebrafish larvae have been employed to understand a variety of microglia functions in the living brain. Here, we performed RNA sequencing of larval zebrafish microglia at different developmental time points: 3, 5, and 7 days post fertilization (dpf). Our analysis reveals that larval zebrafish microglia rapidly acquire the core microglia signature and many typical microglia genes are expressed from 3 dpf onwards. The majority of changes in gene expression happened between 3 and 5 dpf, suggesting that differentiation mainly takes place during these days. Furthermore, we compared the larval microglia transcriptome to published data sets of adult zebrafish microglia, mouse microglia, and human microglia. Larval microglia shared a significant number of expressed genes with their adult counterparts in zebrafish as well as with mouse and human microglia. In conclusion, our results show that larval zebrafish microglia mature rapidly and express the core microglia gene signature that seems to be conserved across species.
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Affiliation(s)
- Julie Mazzolini
- Centre for Discovery Brain SciencesUniversity of EdinburghEdinburghUK
| | - Sigrid Le Clerc
- Laboratoire GBCM, EA7528, Conservatoire National des Arts et MétiersHESAM UniversitéParisFrance
| | - Gregoire Morisse
- Centre for Discovery Brain SciencesUniversity of EdinburghEdinburghUK
| | - Cédric Coulonges
- Laboratoire GBCM, EA7528, Conservatoire National des Arts et MétiersHESAM UniversitéParisFrance
| | - Laura E. Kuil
- Department of Clinical Genetics, Erasmus MCUniversity Medical Center RotterdamRotterdamThe Netherlands
| | - Tjakko J. van Ham
- Department of Clinical Genetics, Erasmus MCUniversity Medical Center RotterdamRotterdamThe Netherlands
| | - Jean‐François Zagury
- Laboratoire GBCM, EA7528, Conservatoire National des Arts et MétiersHESAM UniversitéParisFrance
| | - Dirk Sieger
- Centre for Discovery Brain SciencesUniversity of EdinburghEdinburghUK
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26
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Zambusi A, Ninkovic J. Regeneration of the central nervous system-principles from brain regeneration in adult zebrafish. World J Stem Cells 2020; 12:8-24. [PMID: 32110272 PMCID: PMC7031763 DOI: 10.4252/wjsc.v12.i1.8] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Revised: 11/25/2019] [Accepted: 12/16/2019] [Indexed: 02/06/2023] Open
Abstract
Poor recovery of neuronal functions is one of the most common healthcare challenges for patients with different types of brain injuries and/or neurodegenerative diseases. Therapeutic interventions face two major challenges: (1) How to generate neurons de novo to replenish the neuronal loss caused by injuries or neurodegeneration (restorative neurogenesis) and (2) How to prevent or limit the secondary tissue damage caused by long-term accumulation of glial cells, including microglia, at injury site (glial scar). In contrast to mammals, zebrafish have extensive regenerative capacity in numerous vital organs, including the brain, thus making them a valuable model to improve the existing therapeutic approaches for human brain repair. In response to injuries to the central nervous system (CNS), zebrafish have developed specific mechanisms to promote the recovery of the lost tissue architecture and functionality of the damaged CNS. These mechanisms include the activation of a restorative neurogenic program in a specific set of glial cells (ependymoglia) and the resolution of both the glial scar and inflammation, thus enabling proper neuronal specification and survival. In this review, we discuss the cellular and molecular mechanisms underlying the regenerative ability in the adult zebrafish brain and conclude with the potential applicability of these mechanisms in repair of the mammalian CNS.
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Affiliation(s)
- Alessandro Zambusi
- Helmholtz Center Munich, Biomedical Center, Inst Stem Cell Res, Institute of Stem Cell Research, Department of Cell Biology and Anatomy, University of Munich, Planegg 82152, Germany
| | - Jovica Ninkovic
- Helmholtz Center Munich, Biomedical Center, Inst Stem Cell Res, Institute of Stem Cell Research, Department of Cell Biology and Anatomy, University of Munich, Planegg 82152, Germany
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27
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Eyo UB, Mo M, Yi MH, Murugan M, Liu J, Yarlagadda R, Margolis DJ, Xu P, Wu LJ. P2Y12R-Dependent Translocation Mechanisms Gate the Changing Microglial Landscape. Cell Rep 2019; 23:959-966. [PMID: 29694903 PMCID: PMC5965271 DOI: 10.1016/j.celrep.2018.04.001] [Citation(s) in RCA: 78] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Revised: 02/21/2018] [Accepted: 03/30/2018] [Indexed: 01/01/2023] Open
Abstract
Microglia are an exquisitely tiled and self-contained population in the CNS that do not receive contributions from circulating monocytes in the periphery. While microglia are long-lived cells, the extent to which their cell bodies are fixed and the molecular mechanisms by which the microglial landscape is regulated have not been determined. Using chronic in vivo two-photon imaging to follow the microglial population in young adult mice, we document a daily rearrangement of the microglial landscape. Furthermore, we show that the microglial landscape can be modulated by severe seizures, acute injury, and sensory deprivation. Finally, we demonstrate a critical role for microglial P2Y12Rs in regulating the microglial landscape through cellular translocation independent of proliferation. These findings suggest that microglial patrol the CNS through both process motility and soma translocation.
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Affiliation(s)
- Ukpong B Eyo
- Department of Neurology, Mayo Clinic, Rochester, MN 55905, USA; Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, NJ 08854, USA
| | - Mingshu Mo
- Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, NJ 08854, USA; Department of Neurology, First Affiliated Hospital of Guangzhou Medical University, Guangdong 510120, China
| | - Min-Hee Yi
- Department of Neurology, Mayo Clinic, Rochester, MN 55905, USA
| | - Madhuvika Murugan
- Department of Neurology, Mayo Clinic, Rochester, MN 55905, USA; Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, NJ 08854, USA
| | - Junting Liu
- Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, NJ 08854, USA
| | - Rohan Yarlagadda
- Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, NJ 08854, USA
| | - David J Margolis
- Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, NJ 08854, USA
| | - Pingyi Xu
- Department of Neurology, First Affiliated Hospital of Guangzhou Medical University, Guangdong 510120, China.
| | - Long-Jun Wu
- Department of Neurology, Mayo Clinic, Rochester, MN 55905, USA; Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, NJ 08854, USA; Department of Neuroscience, Mayo Clinic, Jacksonville, FL 32224, USA.
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28
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Zhang Z, Hou H, Yu S, Zhou C, Zhang X, Li N, Zhang S, Song K, Lu Y, Liu D, Lu H, Xu H. Inflammation-induced mammalian target of rapamycin signaling is essential for retina regeneration. Glia 2019; 68:111-127. [PMID: 31444939 DOI: 10.1002/glia.23707] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2019] [Revised: 08/05/2019] [Accepted: 08/07/2019] [Indexed: 12/18/2022]
Abstract
Upon retina injury, Müller glia in the zebrafish retina respond by generating multipotent progenitors to repair the retina. However, the complete mechanisms underlying retina regeneration remain elusive. Here we report inflammation-induced mammalian target of rapamycin (mTOR) signaling in the Müller glia is essential for retina regeneration in adult zebrafish. We show after a stab injury, mTOR is rapidly activated in Müller glia and later Müller glia-derived progenitor cells (MGPCs). Importantly, mTOR is required for Müller glia dedifferentiation, as well as the proliferation of Müller glia and MGPCs. Interestingly, transient mTOR inhibition by rapamycin only reversibly suppresses MGPC proliferation, while its longer suppression by knocking down Raptor significantly inhibits the regeneration of retinal neurons. We further show mTOR promotes retina regeneration by regulating the mRNA expression of key reprogramming factors ascl1a and lin-28a, cell cycle-related genes and critical cytokines. Surprisingly, we identify microglia/macrophage-mediated inflammation as an important upstream regulator of mTOR in the Müller glia and it promotes retina regeneration through mTOR. Our study not only demonstrates the important functions of mTOR but also reveals an interesting link between inflammation and the mTOR signaling during retina regeneration.
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Affiliation(s)
- Zhiqiang Zhang
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Jiangsu Province, China
| | - Haitao Hou
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Jiangsu Province, China
| | - Shuguang Yu
- State Key Laboratory of Neuroscience, Institute of Neuroscience, Shanghai Institutes for Biological Sciences, Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China
| | - Cuiping Zhou
- Department of Ophthalmology, Eye Institute, Affiliated Hospital of Nantong University, Nantong, Jiangsu Province, China
| | - Xiaoli Zhang
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Jiangsu Province, China
| | - Na Li
- Department of Ophthalmology, Eye Institute, Affiliated Hospital of Nantong University, Nantong, Jiangsu Province, China
| | - Shuqiang Zhang
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Jiangsu Province, China
| | - Kaida Song
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Jiangsu Province, China
| | - Ying Lu
- Department of Ophthalmology, Eye Institute, Affiliated Hospital of Nantong University, Nantong, Jiangsu Province, China
| | - Dong Liu
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Jiangsu Province, China
| | - Hong Lu
- Department of Ophthalmology, Eye Institute, Affiliated Hospital of Nantong University, Nantong, Jiangsu Province, China
| | - Hui Xu
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Jiangsu Province, China
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29
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Eyo UB, Wu LJ. Microglia: Lifelong patrolling immune cells of the brain. Prog Neurobiol 2019; 179:101614. [PMID: 31075285 PMCID: PMC6599472 DOI: 10.1016/j.pneurobio.2019.04.003] [Citation(s) in RCA: 64] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Revised: 04/11/2019] [Accepted: 04/19/2019] [Indexed: 02/02/2023]
Abstract
Microglial cells are the predominant parenchymal immune cell of the brain. Recent evidence suggests that like peripheral immune cells, microglia patrol the brain in health and disease. Reviewing these data, we first examine the evidence that microglia invade the brain mesenchyme early in embryonic development, establish residence therein, proliferate and subsequently maintain their numbers throughout life. We, then, summarize established and novel evidence for microglial process surveillance in the healthy and injured brain. Finally, we discuss emerging evidence for microglial cell body dynamics that challenge existing assumptions of their sessile nature. We conclude that microglia are long-lived immune cells that patrol the brain through both cell body and process movements. This recognition has significant implications for neuroimmune interactions throughout the animal lifespan.
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Affiliation(s)
- Ukpong B Eyo
- Department of Neurology, Mayo Clinic, Rochester, MN 55905, USA; Center for Brain Immunology and Glia (BIG), University of Virginia, Charlottesville, VA, USA; Department of Neuroscience, University of Virginia, Charlottesville, VA, USA
| | - Long-Jun Wu
- Department of Neurology, Mayo Clinic, Rochester, MN 55905, USA; Department of Neuroscience, Mayo Clinic, Jacksonville, FL 32224, USA; Department of Immunology, Mayo Clinic, Rochester, MN 55905, USA.
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30
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Tsujioka H, Yamashita T. Comparison of gene expression profile of the spinal cord of sprouting-capable neonatal and sprouting-incapable adult mice. BMC Genomics 2019; 20:619. [PMID: 31362699 PMCID: PMC6668129 DOI: 10.1186/s12864-019-5974-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Accepted: 07/15/2019] [Indexed: 12/11/2022] Open
Abstract
Background The regenerative ability of severed axons in the central nervous system is limited in mammals. However, after central nervous system injury, neural function is partially recovered by the formation of a compensatory neural circuit. In a mouse pyramidotomy model, axonal sprouting of the intact side of the corticospinal tract is observed in the spinal cord, and the axons make new synapses with the denervated side of propriospinal neurons. Moreover, this sprouting ability is enhanced in neonatal mice compared to that in adult mice. Myelin-associated molecules in the spinal cord or intrinsic factors in corticospinal neurons have been investigated in previous studies, but the factors that determine elevated sprouting ability in neonatal mice are not fully understood. Further, in the early phase after pyramidotomy, glial responses are observed in the spinal cord. To elucidate the basal difference in the spinal cord, we compared gene expression profiles of entire C4–7 cervical cord tissues between neonatal (injured at postnatal day 7) and adult (injured at 8 weeks of age) mice by RNA-sequencing. We also tried to identify discordant gene expression changes that might inhibit axonal sprouting in adult mice at the early phase (3 days) after pyramidotomy. Results A comparison of neonatal and adult sham groups revealed remarkable basal differences in the spinal cord, such as active neural circuit formation, cell proliferation, the development of myelination, and an immature immune system in neonatal mice compared to that observed in adult mice. Some inflammation-related genes were selectively expressed in adult mice after pyramidotomy, implying the possibility that these genes might be related to the low sprouting ability in adult mice. Conclusions This study provides useful information regarding the basal difference between neonatal and adult spinal cords and the possible differential response after pyramidotomy, both of which are necessary to understand why sprouting ability is increased in neonatal mice compared to that in adult mice. Electronic supplementary material The online version of this article (10.1186/s12864-019-5974-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Hiroshi Tsujioka
- Department of Molecular Neuroscience, Graduate School of Medicine, Osaka University, Osaka, Japan.,WPI Immunology Frontier Research Center, Osaka University, Osaka, Japan
| | - Toshihide Yamashita
- Department of Molecular Neuroscience, Graduate School of Medicine, Osaka University, Osaka, Japan. .,WPI Immunology Frontier Research Center, Osaka University, Osaka, Japan. .,Graduate School of Frontier Bioscience, Osaka University, Osaka, Japan. .,Department of Neuro-Medical Science, Graduate School of Medicine, Osaka University, Osaka, Japan.
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31
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Wang T, Yan B, Lou L, Lin X, Yu T, Wu S, Lu Q, Liu W, Huang Z, Zhang M, Zhang W, Wen Z. Nlrc3-like is required for microglia maintenance in zebrafish. J Genet Genomics 2019; 46:291-299. [PMID: 31278008 DOI: 10.1016/j.jgg.2019.06.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Revised: 06/17/2019] [Accepted: 06/17/2019] [Indexed: 01/06/2023]
Abstract
Microglia are tissue-resident macrophages residing in the central nervous system (CNS) and play critical roles in removing cellular debris and infectious agents as well as regulating neurogenesis and neuronal activities. Yet, the molecular basis underlying the establishment of microglia pool and the maintenance of their homeostasis in the CNS remain largely undefined. Here we report the identification and characterization of a mutant zebrafish, which harbors a point mutation in the nucleotide-binding oligomerization domain (NOD) like receptor gene nlrc3-like, resulting in the loss of microglia in a temperature sensitive manner. Temperature shift assay reveals that the late onset of nlrc3-like deficiency leads to excessive microglia cell death. Further analysis shows that the excessive microglia death in nlrc3-like deficient mutants is attributed, at least in part, to aberrant activation of canonical inflammasome pathway. Our study indicates that proper regulation of inflammasome cascade is critical for the maintenance of microglia homeostasis.
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Affiliation(s)
- Tienan Wang
- Division of Life Science and State Key Laboratory of Molecular Neuroscience, Center of Systems Biology and Human Health, The Hong Kong University of Science and Technology, Clearwater Bay, Kowloon, Hong Kong, China; Division of Life Science, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Bo Yan
- Shanghai Public Health Clinical Center, Fudan University, Shanghai, 201508, China; Division of Life Science, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China.
| | - Liang Lou
- Division of Life Science and State Key Laboratory of Molecular Neuroscience, Center of Systems Biology and Human Health, The Hong Kong University of Science and Technology, Clearwater Bay, Kowloon, Hong Kong, China
| | - Xi Lin
- Division of Life Science and State Key Laboratory of Molecular Neuroscience, Center of Systems Biology and Human Health, The Hong Kong University of Science and Technology, Clearwater Bay, Kowloon, Hong Kong, China
| | - Tao Yu
- Division of Life Science and State Key Laboratory of Molecular Neuroscience, Center of Systems Biology and Human Health, The Hong Kong University of Science and Technology, Clearwater Bay, Kowloon, Hong Kong, China
| | - Shuting Wu
- Division of Life Science and State Key Laboratory of Molecular Neuroscience, Center of Systems Biology and Human Health, The Hong Kong University of Science and Technology, Clearwater Bay, Kowloon, Hong Kong, China
| | - Qing Lu
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders, Ministry of Education, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Wei Liu
- Department of Developmental Biology, School of Basic Medical Sciences, South China University of Technology, Guangzhou, 510630, China
| | - Zhibin Huang
- Department of Developmental Biology, School of Basic Medical Sciences, South China University of Technology, Guangzhou, 510630, China
| | - Mingjie Zhang
- Division of Life Science and State Key Laboratory of Molecular Neuroscience, Center of Systems Biology and Human Health, The Hong Kong University of Science and Technology, Clearwater Bay, Kowloon, Hong Kong, China
| | - Wenqing Zhang
- Department of Developmental Biology, School of Basic Medical Sciences, South China University of Technology, Guangzhou, 510630, China.
| | - Zilong Wen
- Division of Life Science and State Key Laboratory of Molecular Neuroscience, Center of Systems Biology and Human Health, The Hong Kong University of Science and Technology, Clearwater Bay, Kowloon, Hong Kong, China.
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Rougeot J, Torraca V, Zakrzewska A, Kanwal Z, Jansen HJ, Sommer F, Spaink HP, Meijer AH. RNAseq Profiling of Leukocyte Populations in Zebrafish Larvae Reveals a cxcl11 Chemokine Gene as a Marker of Macrophage Polarization During Mycobacterial Infection. Front Immunol 2019; 10:832. [PMID: 31110502 PMCID: PMC6499218 DOI: 10.3389/fimmu.2019.00832] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Accepted: 03/29/2019] [Indexed: 12/13/2022] Open
Abstract
Macrophages are phagocytic cells from the innate immune system, which forms the first line of host defense against invading pathogens. These highly dynamic immune cells can adopt specific functional phenotypes, with the pro-inflammatory M1 and anti-inflammatory M2 polarization states as the two extremes. Recently, the process of macrophage polarization during inflammation has been visualized by real time imaging in larvae of the zebrafish. This model organism has also become widely used to study macrophage responses to microbial pathogens. To support the increasing use of zebrafish in macrophage biology, we set out to determine the complete transcriptome of zebrafish larval macrophages. We studied the specificity of the macrophage signature compared with other larval immune cells and the macrophage-specific expression changes upon infection. We made use of the well-established mpeg1, mpx, and lck fluorescent reporter lines to sort and sequence the transcriptome of larval macrophages, neutrophils, and lymphoid progenitor cells, respectively. Our results provide a complete dataset of genes expressed in these different immune cell types and highlight their similarities and differences. Major differences between the macrophage and neutrophil signatures were found within the families of proteinases. Furthermore, expression of genes involved in antigen presentation and processing was specifically detected in macrophages, while lymphoid progenitors showed expression of genes involved in macrophage activation. Comparison with datasets of in vitro polarized human macrophages revealed that zebrafish macrophages express a strongly homologous gene set, comprising both M1 and M2 markers. Furthermore, transcriptome analysis of low numbers of macrophages infected by the intracellular pathogen Mycobacterium marinum revealed that infected macrophages change their transcriptomic response by downregulation of M2-associated genes and overexpression of specific M1-associated genes. Among the infection-induced genes, a homolog of the human CXCL11 chemokine gene, cxcl11aa, stood out as the most strongly overexpressed M1 marker. Upregulation of cxcl11aa in Mycobacterium-infected macrophages was found to require the function of Myd88, a critical adaptor molecule in the Toll-like and interleukin 1 receptor pathways that are central to pathogen recognition and activation of the innate immune response. Altogether, our data provide a valuable data mining resource to support infection and inflammation research in the zebrafish model.
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Affiliation(s)
- Julien Rougeot
- Institute of Biology Leiden, Leiden University, Leiden, Netherlands
| | - Vincenzo Torraca
- Institute of Biology Leiden, Leiden University, Leiden, Netherlands
| | - Ania Zakrzewska
- Institute of Biology Leiden, Leiden University, Leiden, Netherlands
| | - Zakia Kanwal
- Institute of Biology Leiden, Leiden University, Leiden, Netherlands
| | | | - Frida Sommer
- Institute of Biology Leiden, Leiden University, Leiden, Netherlands
| | - Herman P Spaink
- Institute of Biology Leiden, Leiden University, Leiden, Netherlands
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33
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Uweru JO, Eyo UB. A decade of diverse microglial-neuronal physical interactions in the brain (2008-2018). Neurosci Lett 2019; 698:33-38. [PMID: 30625349 PMCID: PMC6435396 DOI: 10.1016/j.neulet.2019.01.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Revised: 12/29/2018] [Accepted: 01/01/2019] [Indexed: 12/17/2022]
Abstract
Microglia are unique cells of the central nervous system (CNS) with a distinct ontogeny and molecular profile. They are the predominant immune resident cell in the CNS. Recent studies have revealed a diversity of transient and terminal physical interactions between microglia and neurons in the vertebrate brain. In this review, we follow the historical trail of the discovery of these interactions, summarize their notable features, provide implications of these discoveries to CNS function, emphasize emerging themes along the way and peak into the future of what outstanding questions remain to move the field forward.
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Affiliation(s)
- Joseph O Uweru
- Department of Neuroscience, University of Virginia, Charlottesville, VA, United States; Neuroscience Graduate Program, University of Virginia, Charlottesville, VA, United States; Center for Brain Immunology and Glia (BIG), University of Virginia, Charlottesville, VA, United States
| | - Ukpong B Eyo
- Department of Neuroscience, University of Virginia, Charlottesville, VA, United States; Neuroscience Graduate Program, University of Virginia, Charlottesville, VA, United States; Center for Brain Immunology and Glia (BIG), University of Virginia, Charlottesville, VA, United States.
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34
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Smolders SMT, Kessels S, Vangansewinkel T, Rigo JM, Legendre P, Brône B. Microglia: Brain cells on the move. Prog Neurobiol 2019; 178:101612. [PMID: 30954517 DOI: 10.1016/j.pneurobio.2019.04.001] [Citation(s) in RCA: 64] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Revised: 02/13/2019] [Accepted: 04/01/2019] [Indexed: 02/08/2023]
Abstract
In the last decade, tremendous progress has been made in understanding the biology of microglia - i.e. the fascinating immigrated resident immune cell population of the central nervous system (CNS). Recent literature reviews have largely dealt with the plentiful functions of microglia in CNS homeostasis, development and pathology, and the influences of sex and the microbiome. In this review, the intriguing aspect of their physical plasticity during CNS development will get specific attention. Microglia move around (mobility) and reshape their processes (motility). Microglial migration into and inside the CNS is most prominent throughout development and consequently most of the data described in this review concern mobility and motility in the changing environment of the developing brain. Here, we first define microglia based on their highly specialized age- and region-dependent gene expression signature and associated functional heterogeneity. Next, we describe their origin, the migration route of immature microglial cells towards the CNS, the mechanisms underlying their invasion of the CNS, and their spatiotemporal localization and surveying behaviour inside the developing CNS. These processes are dependent on microglial mobility and motility which are determined by the microenvironment of the CNS. Therefore, we further zoom in on the changing environment during CNS development. We elaborate on the extracellular matrix and the respective integrin receptors on microglia and we discuss the purinergic and molecular signalling in microglial mobility. In the last section, we discuss the physiological and pathological functions of microglia in which mobility and motility are involved to stress the importance of microglial 'movement'.
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Affiliation(s)
- Sophie Marie-Thérèse Smolders
- UHasselt, BIOMED, Diepenbeek, Belgium; INSERM, UMR-S 1130, CNRS, UMR 8246, Neuroscience Paris Seine, Institute of Biology Paris Seine, Paris, France; Sorbonne Universités, UPMC Université Paris 06, UM CR18, Neuroscience Paris Seine, Paris, France
| | | | | | | | - Pascal Legendre
- INSERM, UMR-S 1130, CNRS, UMR 8246, Neuroscience Paris Seine, Institute of Biology Paris Seine, Paris, France; Sorbonne Universités, UPMC Université Paris 06, UM CR18, Neuroscience Paris Seine, Paris, France
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35
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Mitchell DM, Sun C, Hunter SS, New DD, Stenkamp DL. Regeneration associated transcriptional signature of retinal microglia and macrophages. Sci Rep 2019; 9:4768. [PMID: 30886241 PMCID: PMC6423051 DOI: 10.1038/s41598-019-41298-8] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2018] [Accepted: 03/04/2019] [Indexed: 02/08/2023] Open
Abstract
Zebrafish have the remarkable capacity to regenerate retinal neurons following a variety of damage paradigms. Following initial tissue insult and a period of cell death, a proliferative phase ensues that generates neuronal progenitors, which ultimately regenerate damaged neurons. Recent work has revealed that Müller glia are the source of regenerated neurons in zebrafish. However, the roles of another important class of glia present in the retina, microglia, during this regenerative phase remain elusive. Here, we examine retinal tissue and perform QuantSeq. 3'mRNA sequencing/transcriptome analysis to reveal localization and putative functions, respectively, of mpeg1 expressing cells (microglia/macrophages) during Müller glia-mediated regeneration, corresponding to a time of progenitor proliferation and production of new neurons. Our results indicate that in this regenerative state, mpeg1-expressing cells are located in regions containing regenerative Müller glia and are likely engaged in active vesicle trafficking. Further, mpeg1+ cells congregate at and around the optic nerve head. Our transcriptome analysis reveals several novel genes not previously described in microglia. This dataset represents the first report, to our knowledge, to use RNA sequencing to probe the microglial transcriptome in such context, and therefore provides a resource towards understanding microglia/macrophage function during successful retinal (and central nervous tissue) regeneration.
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Affiliation(s)
- Diana M Mitchell
- Department of Biological Sciences, University of Idaho, Moscow, ID, 83844, USA.
| | - Chi Sun
- Department of Biological Sciences, University of Idaho, Moscow, ID, 83844, USA
- Ophthalmology, Washington University in St. Louis, 4523 Clayton Ave St. Louis, Missouri, 63110, USA
| | - Samuel S Hunter
- Institute for Bioinformatics and Evolutionary Studies, University of Idaho, Moscow, ID, 83844, USA
| | - Daniel D New
- Institute for Bioinformatics and Evolutionary Studies, University of Idaho, Moscow, ID, 83844, USA
| | - Deborah L Stenkamp
- Department of Biological Sciences, University of Idaho, Moscow, ID, 83844, USA
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36
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Midbrain tectal stem cells display diverse regenerative capacities in zebrafish. Sci Rep 2019; 9:4420. [PMID: 30872640 PMCID: PMC6418144 DOI: 10.1038/s41598-019-40734-z] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Accepted: 02/20/2019] [Indexed: 12/18/2022] Open
Abstract
How diverse adult stem and progenitor populations regenerate tissue following damage to the brain is poorly understood. In highly regenerative vertebrates, such as zebrafish, radial-glia (RG) and neuro-epithelial-like (NE) stem/progenitor cells contribute to neuronal repair after injury. However, not all RG act as neural stem/progenitor cells during homeostasis in the zebrafish brain, questioning the role of quiescent RG (qRG) post-injury. To understand the function of qRG during regeneration, we performed a stab lesion in the adult midbrain tectum to target a population of homeostatic qRG, and investigated their proliferative behaviour, differentiation potential, and Wnt/β-catenin signalling. EdU-labelling showed a small number of proliferating qRG after injury (pRG) but that progeny are restricted to RG. However, injury promoted proliferation of NE progenitors in the internal tectal marginal zone (TMZi) resulting in amplified regenerative neurogenesis. Increased Wnt/β-catenin signalling was detected in TMZi after injury whereas homeostatic levels of Wnt/β-catenin signalling persisted in qRG/pRG. Attenuation of Wnt signalling suggested that the proliferative response post-injury was Wnt/β-catenin-independent. Our results demonstrate that qRG in the tectum have restricted capability in neuronal repair, highlighting that RG have diverse functions in the zebrafish brain. Furthermore, these findings suggest that endogenous stem cell compartments compensate lost tissue by amplifying homeostatic growth.
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37
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Kuil LE, Oosterhof N, Geurts SN, van der Linde HC, Meijering E, van Ham TJ. Reverse genetic screen reveals that Il34 facilitates yolk sac macrophage distribution and seeding of the brain. Dis Model Mech 2019; 12:dmm037762. [PMID: 30765415 PMCID: PMC6451432 DOI: 10.1242/dmm.037762] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Accepted: 02/06/2019] [Indexed: 12/30/2022] Open
Abstract
Microglia are brain-resident macrophages, which have specialized functions important in brain development and in disease. They colonize the brain in early embryonic stages, but few factors that drive the migration of yolk sac macrophages (YSMs) into the embryonic brain, or regulate their acquisition of specialized properties, are currently known. Here, we present a CRISPR/Cas9-based in vivo reverse genetic screening pipeline to identify new microglia regulators using zebrafish. Zebrafish larvae are particularly suitable due to their external development, transparency and conserved microglia features. We targeted putative microglia regulators, by Cas9/gRNA complex injections, followed by Neutral-Red-based visualization of microglia. Microglia were quantified automatically in 3-day-old larvae using a software tool we called SpotNGlia. We identified that loss of zebrafish colony-stimulating factor 1 receptor (Csf1r) ligand, Il34, caused reduced microglia numbers. Previous studies on the role of IL34 in microglia development in vivo were ambiguous. Our data, and a concurrent paper, show that, in zebrafish, il34 is required during the earliest seeding of the brain by microglia. Our data also indicate that Il34 is required for YSM distribution to other organs. Disruption of the other Csf1r ligand, Csf1, did not reduce microglia numbers in mutants, whereas overexpression increased the number of microglia. This shows that Csf1 can influence microglia numbers, but might not be essential for the early seeding of the brain. In all, we identified il34 as a modifier of microglia colonization, by affecting distribution of YSMs to target organs, validating our reverse genetic screening pipeline in zebrafish.This article has an associated First Person interview with the joint first authors of the paper.
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Affiliation(s)
- Laura E Kuil
- Department of Clinical Genetics, Erasmus University Medical Center, Wytemaweg 80, 3015 CN Rotterdam, The Netherlands
| | - Nynke Oosterhof
- Department of Clinical Genetics, Erasmus University Medical Center, Wytemaweg 80, 3015 CN Rotterdam, The Netherlands
- European Research Institute for the Biology of Ageing, University Medical Center Groningen, Antonius Deusinglaan 1, 9713 AV Groningen, The Netherlands
| | - Samuël N Geurts
- Biomedical Imaging Group Rotterdam, Departments of Medical Informatics and Radiology, Erasmus University Medical Center, Wytemaweg 80, 3015 CN Rotterdam, The Netherlands
- Quantitative Imaging, Faculty of Applied Sciences, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands
| | - Herma C van der Linde
- Department of Clinical Genetics, Erasmus University Medical Center, Wytemaweg 80, 3015 CN Rotterdam, The Netherlands
| | - Erik Meijering
- Biomedical Imaging Group Rotterdam, Departments of Medical Informatics and Radiology, Erasmus University Medical Center, Wytemaweg 80, 3015 CN Rotterdam, The Netherlands
| | - Tjakko J van Ham
- Department of Clinical Genetics, Erasmus University Medical Center, Wytemaweg 80, 3015 CN Rotterdam, The Netherlands
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38
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Nyamugenda E, Trentzsch M, Russell S, Miles T, Boysen G, Phelan KD, Baldini G. Injury to hypothalamic Sim1 neurons is a common feature of obesity by exposure to high-fat diet in male and female mice. J Neurochem 2019; 149:73-97. [PMID: 30615192 DOI: 10.1111/jnc.14662] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Revised: 10/16/2018] [Accepted: 01/04/2019] [Indexed: 12/13/2022]
Abstract
The hypothalamus is essential for regulation of energy homeostasis and metabolism. Feeding hypercaloric, high-fat (HF) diet induces hypothalamic arcuate nucleus injury and alters metabolism more severely in male than in female mice. The site(s) and extent of hypothalamic injury in male and female mice are not completely understood. In the paraventricular nucleus (PVN) of the hypothalamus, single-minded family basic helix-loop helix transcription factor 1 (Sim1) neurons are essential to control energy homeostasis. We tested the hypothesis that exposure to HF diet induces injury to Sim1 neurons in the PVN of male and female mice. Mice expressing membrane-bound enhanced green fluorescent protein (mEGFP) in Sim1 neurons (Sim1-Cre:Rosa-mEGFP mice) were generated to visualize the effects of exposure to HF diet on these neurons. Male and female Sim1-Cre:Rosa-mEGFP mice exposed to HF diet had increased weight, hyperleptinemia, and developed hepatosteatosis. In male and female mice exposed to HF diet, expression of mEGFP was reduced by > 40% in Sim1 neurons of the PVN, an effect paralleled by cell apoptosis and neuronal loss, but not by microgliosis. In the arcuate nucleus of the Sim1-Cre:Rosa-mEGFP male mice, there was decreased alpha-melanocyte-stimulating hormone in proopiomelanocortin neurons projecting to the PVN, with increased cell apoptosis, neuronal loss, and microgliosis. These defects were undetectable in the arcuate nucleus of female mice exposed to the HF diet. Thus, injury to Sim1 neurons of the PVN is a shared feature of exposure to HF diet in mice of both sexes, while injury to proopiomelanocortin neurons in arcuate nucleus is specific to male mice. OPEN SCIENCE BADGES: This article has received a badge for *Open Materials* because it provided all relevant information to reproduce the study in the manuscript. The complete Open Science Disclosure form for this article can be found at the end of the article. More information about the Open Practices badges can be found at https://cos.io/our-services/open-science-badges/.
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Affiliation(s)
- Eugene Nyamugenda
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Marcus Trentzsch
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Susan Russell
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Tiffany Miles
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Gunnar Boysen
- Department of Environmental and Occupational Health, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA.,The Winthrop P Rockefeller Cancer Institute, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Kevin D Phelan
- Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Giulia Baldini
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
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39
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Martins RR, Ellis PS, MacDonald RB, Richardson RJ, Henriques CM. Resident Immunity in Tissue Repair and Maintenance: The Zebrafish Model Coming of Age. Front Cell Dev Biol 2019; 7:12. [PMID: 30805338 PMCID: PMC6370978 DOI: 10.3389/fcell.2019.00012] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2018] [Accepted: 01/18/2019] [Indexed: 12/21/2022] Open
Abstract
The zebrafish has emerged as an exciting vertebrate model to study different aspects of immune system development, particularly due to its transparent embryonic development, the availability of multiple fluorescent reporter lines, efficient genetic tools and live imaging capabilities. However, the study of immunity in zebrafish has largely been limited to early larval stages due to an incomplete knowledge of the full repertoire of immune cells and their specific markers, in particular, a lack of cell surface antibodies to detect and isolate such cells in living tissues. Here we focus on tissue resident or associated immunity beyond development, in the adult zebrafish. It is our view that, with our increasing knowledge and the development of improved tools and protocols, the adult zebrafish will be increasingly appreciated for offering valuable insights into the role of immunity in tissue repair and maintenance, in both health and disease throughout the lifecourse.
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Affiliation(s)
- Raquel Rua Martins
- Department of Oncology and Metabolism, Medical School, University of Sheffield, Sheffield, United Kingdom.,Bateson Centre, University of Sheffield, Sheffield, United Kingdom
| | - Pam S Ellis
- Department of Oncology and Metabolism, Medical School, University of Sheffield, Sheffield, United Kingdom.,Bateson Centre, University of Sheffield, Sheffield, United Kingdom
| | - Ryan B MacDonald
- Bateson Centre, University of Sheffield, Sheffield, United Kingdom.,Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield, Sheffield, United Kingdom
| | - Rebecca J Richardson
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, United Kingdom
| | - Catarina Martins Henriques
- Department of Oncology and Metabolism, Medical School, University of Sheffield, Sheffield, United Kingdom.,Bateson Centre, University of Sheffield, Sheffield, United Kingdom
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40
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Svahn AJ, Don EK, Badrock AP, Cole NJ, Graeber MB, Yerbury JJ, Chung R, Morsch M. Nucleo-cytoplasmic transport of TDP-43 studied in real time: impaired microglia function leads to axonal spreading of TDP-43 in degenerating motor neurons. Acta Neuropathol 2018; 136:445-459. [PMID: 29943193 PMCID: PMC6096729 DOI: 10.1007/s00401-018-1875-2] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Revised: 06/09/2018] [Accepted: 06/09/2018] [Indexed: 02/08/2023]
Abstract
Transactivating DNA-binding protein-43 (TDP-43) deposits represent a typical finding in almost all ALS patients, more than half of FTLD patients and patients with several other neurodegenerative disorders. It appears that perturbation of nucleo-cytoplasmic transport is an important event in these conditions but the mechanistic role and the fate of TDP-43 during neuronal degeneration remain elusive. We have developed an experimental system for visualising the perturbed nucleocytoplasmic transport of neuronal TDP-43 at the single-cell level in vivo using zebrafish spinal cord. This approach enabled us to image TDP-43-expressing motor neurons before and after experimental initiation of cell death. We report the formation of mobile TDP-43 deposits within degenerating motor neurons, which are normally phagocytosed by microglia. However, when microglial cells were depleted, injury-induced motor neuron degeneration follows a characteristic process that includes TDP-43 redistribution into the cytoplasm, axon and extracellular space. This is the first demonstration of perturbed TDP-43 nucleocytoplasmic transport in vivo, and suggests that impairment in microglial phagocytosis of dying neurons may contribute towards the formation of pathological TDP-43 presentations in ALS and FTLD.
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41
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Zhao X, Eyo UB, Murguan M, Wu LJ. Microglial interactions with the neurovascular system in physiology and pathology. Dev Neurobiol 2018; 78:604-617. [PMID: 29318762 PMCID: PMC5980686 DOI: 10.1002/dneu.22576] [Citation(s) in RCA: 73] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2017] [Revised: 01/01/2018] [Accepted: 01/06/2018] [Indexed: 01/11/2023]
Abstract
Microglia as immune cells of the central nervous system (CNS) play significant roles not only in pathology but also in physiology, such as shaping of the CNS during development and its proper maintenance in maturity. Emerging research is showing a close association between microglia and the neurovasculature that is critical for brain energy supply. In this review, we summarize the current literature on microglial interaction with the vascular system in the normal and diseased brain. First, we highlight data that indicate interesting potential involvement of microglia in developmental angiogenesis. Then we discuss the evidence for microglial participation with the vasculature in neuropathologies from brain tumors to acute injuries such as ischemic stroke to chronic neurodegenerative conditions. We conclude by suggesting future areas of research to advance the field in light of current technical progress and outstanding questions. © 2018 Wiley Periodicals, Inc. Develop Neurobiol 78: 604-617, 2018.
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Affiliation(s)
- Xiaoliang Zhao
- Department of Neurology, Mayo Clinic, Rochester, MN 55905
| | - Ukpong B. Eyo
- Department of Neurology, Mayo Clinic, Rochester, MN 55905
- Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, NJ 08854
| | - Madhuvika Murguan
- Department of Neurology, Mayo Clinic, Rochester, MN 55905
- Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, NJ 08854
| | - Long-Jun Wu
- Department of Neurology, Mayo Clinic, Rochester, MN 55905
- Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, NJ 08854
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42
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Hiragi T, Ikegaya Y, Koyama R. Microglia after Seizures and in Epilepsy. Cells 2018; 7:cells7040026. [PMID: 29597334 PMCID: PMC5946103 DOI: 10.3390/cells7040026] [Citation(s) in RCA: 100] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Revised: 03/24/2018] [Accepted: 03/26/2018] [Indexed: 01/23/2023] Open
Abstract
Microglia are the resident immune cells in the brain that constitute the brain’s innate immune system. Recent studies have revealed various functions of microglia in the development and maintenance of the central nervous system (CNS) in both health and disease. However, the role of microglia in epilepsy remains largely undiscovered, partly because of the complex phenotypes of activated microglia. Activated microglia likely exert different effects on brain function depending on the phase of epileptogenesis. In this review, we mainly focus on the animal models of temporal lobe epilepsy (TLE) and discuss the proepileptic and antiepileptic roles of activated microglia in the epileptic brain. Specifically, we focus on the roles of microglia in the production of inflammatory cytokines, regulation of neurogenesis, and surveillance of the surrounding environment in epilepsy.
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Affiliation(s)
- Toshimitsu Hiragi
- Laboratory of Chemical Pharmacology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-8654, Japan.
| | - Yuji Ikegaya
- Laboratory of Chemical Pharmacology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-8654, Japan.
| | - Ryuta Koyama
- Laboratory of Chemical Pharmacology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-8654, Japan.
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43
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Morrice JR, Gregory-Evans CY, Shaw CA. Modeling Environmentally-Induced Motor Neuron Degeneration in Zebrafish. Sci Rep 2018; 8:4890. [PMID: 29559645 PMCID: PMC5861069 DOI: 10.1038/s41598-018-23018-w] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Accepted: 03/05/2018] [Indexed: 12/13/2022] Open
Abstract
Zebrafish have been used to investigate motor neuron degeneration, including as a model system to examine the pathogenesis of amyotrophic lateral sclerosis (ALS). The use of zebrafish for this purpose has some advantages over other in vivo model systems. In the current paper, we show that bisphenol A (BPA) exposure in zebrafish embryos results in motor neuron degeneration with affected motor function, reduced motor axon length and branching, reduced neuromuscular junction integrity, motor neuron cell death and the presence of activated microglia. In zebrafish, motor axon length is the conventional method for estimating motor neuron degeneration, yet this measurement has not been confirmed as a valid surrogate marker. We also show that reduced motor axon length as measured from the sagittal plane is correlated with increased motor neuron cell death. Our preliminary timeline studies suggest that axonopathy precedes motor cell death. This outcome may have implications for early phase treatments of motor neuron degeneration.
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Affiliation(s)
- Jessica R Morrice
- Experimental Medicine Program, University of British Columbia, Vancouver, Canada
| | - Cheryl Y Gregory-Evans
- Experimental Medicine Program, University of British Columbia, Vancouver, Canada.,Graduate Program in Neuroscience, University of British Columbia, Vancouver, Canada.,Department of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, Canada
| | - Christopher A Shaw
- Experimental Medicine Program, University of British Columbia, Vancouver, Canada. .,Graduate Program in Neuroscience, University of British Columbia, Vancouver, Canada. .,Department of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, Canada.
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44
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Chia K, Mazzolini J, Mione M, Sieger D. Tumor initiating cells induce Cxcr4-mediated infiltration of pro-tumoral macrophages into the brain. eLife 2018; 7:e31918. [PMID: 29465400 PMCID: PMC5821457 DOI: 10.7554/elife.31918] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Accepted: 01/31/2018] [Indexed: 12/28/2022] Open
Abstract
It is now clear that microglia and macrophages are present in brain tumors, but whether or how they affect initiation and development of tumors is not known. Exploiting the advantages of the zebrafish (Danio rerio) model, we showed that macrophages and microglia respond immediately upon oncogene activation in the brain. Overexpression of human AKT1 within neural cells of larval zebrafish led to a significant increase in the macrophage and microglia populations. By using a combination of transgenic and mutant zebrafish lines, we showed that this increase was caused by the infiltration of peripheral macrophages into the brain mediated via Sdf1b-Cxcr4b signaling. Intriguingly, confocal live imaging reveals highly dynamic interactions between macrophages/microglia and pre-neoplastic cells, which do not result in phagocytosis of pre-neoplastic cells. Finally, depletion of macrophages and microglia resulted in a significant reduction of oncogenic cell proliferation. Thus, macrophages and microglia show tumor promoting functions already during the earliest stages of the developing tumor microenvironment.
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Affiliation(s)
- Kelda Chia
- Centre for Discovery Brain SciencesUniversity of EdinburghEdinburghUnited Kingdom
| | - Julie Mazzolini
- Centre for Discovery Brain SciencesUniversity of EdinburghEdinburghUnited Kingdom
| | - Marina Mione
- Centre for Integrative Biology (CIBIO)University of TrentoTrentoItaly
| | - Dirk Sieger
- Centre for Discovery Brain SciencesUniversity of EdinburghEdinburghUnited Kingdom
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Gore AV, Pillay LM, Venero Galanternik M, Weinstein BM. The zebrafish: A fintastic model for hematopoietic development and disease. WILEY INTERDISCIPLINARY REVIEWS-DEVELOPMENTAL BIOLOGY 2018; 7:e312. [PMID: 29436122 DOI: 10.1002/wdev.312] [Citation(s) in RCA: 122] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Revised: 11/30/2017] [Accepted: 12/03/2017] [Indexed: 12/19/2022]
Abstract
Hematopoiesis is a complex process with a variety of different signaling pathways influencing every step of blood cell formation from the earliest precursors to final differentiated blood cell types. Formation of blood cells is crucial for survival. Blood cells carry oxygen, promote organ development and protect organs in different pathological conditions. Hematopoietic stem and progenitor cells (HSPCs) are responsible for generating all adult differentiated blood cells. Defects in HSPCs or their downstream lineages can lead to anemia and other hematological disorders including leukemia. The zebrafish has recently emerged as a powerful vertebrate model system to study hematopoiesis. The developmental processes and molecular mechanisms involved in zebrafish hematopoiesis are conserved with higher vertebrates, and the genetic and experimental accessibility of the fish and the optical transparency of its embryos and larvae make it ideal for in vivo analysis of hematopoietic development. Defects in zebrafish hematopoiesis reliably phenocopy human blood disorders, making it a highly attractive model system to screen small molecules to design therapeutic strategies. In this review, we summarize the key developmental processes and molecular mechanisms of zebrafish hematopoiesis. We also discuss recent findings highlighting the strengths of zebrafish as a model system for drug discovery against hematopoietic disorders. This article is categorized under: Adult Stem Cells, Tissue Renewal, and Regeneration > Stem Cell Differentiation and Reversion Vertebrate Organogenesis > Musculoskeletal and Vascular Nervous System Development > Vertebrates: Regional Development Comparative Development and Evolution > Organ System Comparisons Between Species.
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Affiliation(s)
- Aniket V Gore
- Division of Developmental Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, Maryland
| | - Laura M Pillay
- Division of Developmental Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, Maryland
| | - Marina Venero Galanternik
- Division of Developmental Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, Maryland
| | - Brant M Weinstein
- Division of Developmental Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, Maryland
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Sun C, Galicia C, Stenkamp DL. Transcripts within rod photoreceptors of the Zebrafish retina. BMC Genomics 2018; 19:127. [PMID: 29422031 PMCID: PMC5806438 DOI: 10.1186/s12864-018-4499-y] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Accepted: 01/28/2018] [Indexed: 12/03/2022] Open
Abstract
BACKGROUND The purpose of this study was to identify transcripts of retinal rod photoreceptors of the zebrafish. The zebrafish is an important animal model for vision science due to rapid and tractable development, persistent neurogenesis of rods throughout the lifespan, and capacity for functional retinal regeneration. RESULTS Zebrafish rods, and non-rod retinal cells of the xops:eGFP transgenic line, were separated by cell dissociation and fluorescence-activated cell sorting (FACS), followed by RNA-seq. At a false discovery rate of < 0.01, 597 transcripts were upregulated ("enriched") in rods vs. other retinal cells, and 1032 were downregulated ("depleted"). Thirteen thousand three hundred twenty four total transcripts were detected in rods, including many not previously known to be expressed by rods. Forty five transcripts were validated by qPCR in FACS-sorted rods vs. other retinal cells. Transcripts enriched in rods from adult retinas were also enriched in rods from larval and juvenile retinas, and were also enriched in rods sorted from retinas subjected to a neurotoxic lesion and allowed to regenerate. Many transcripts enriched in rods were upregulated in retinas of wildtype retinas vs. those of a zebrafish model for rod degeneration. CONCLUSIONS We report the generation and validation of an RNA-seq dataset describing the rod transcriptome of the zebrafish, which is now available as a resource for further studies of rod photoreceptor biology and comparative transcriptomics.
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Affiliation(s)
- Chi Sun
- Department of Biological Sciences, University of Idaho, 875 Perimeter Drive, MS 3051, Moscow, ID 83844-3051 USA
| | - Carlos Galicia
- Department of Biological Sciences, University of Idaho, 875 Perimeter Drive, MS 3051, Moscow, ID 83844-3051 USA
| | - Deborah L. Stenkamp
- Department of Biological Sciences, University of Idaho, 875 Perimeter Drive, MS 3051, Moscow, ID 83844-3051 USA
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van der Vaart M, Svoboda O, Weijts BG, Espín-Palazón R, Sapp V, Pietri T, Bagnat M, Muotri AR, Traver D. Mecp2 regulates tnfa during zebrafish embryonic development and acute inflammation. Dis Model Mech 2017; 10:1439-1451. [PMID: 28993314 PMCID: PMC5769600 DOI: 10.1242/dmm.026922] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Accepted: 10/05/2017] [Indexed: 12/15/2022] Open
Abstract
Mutations in MECP2 cause Rett syndrome, a severe neurological disorder with autism-like features. Duplication of MECP2 also causes severe neuropathology. Both diseases display immunological abnormalities that suggest a role for MECP2 in controlling immune and inflammatory responses. Here, we used mecp2-null zebrafish to study the potential function of Mecp2 as an immunological regulator. Mecp2 deficiency resulted in an increase in neutrophil infiltration and upregulated expression of the pro- and anti-inflammatory cytokines Il1b and Il10 as a secondary response to disturbances in tissue homeostasis. By contrast, expression of the proinflammatory cytokine tumor necrosis factor alpha (Tnfa) was consistently downregulated in mecp2-null animals during development, representing the earliest developmental phenotype described for MECP2 deficiency to date. Expression of tnfa was unresponsive to inflammatory stimulation, and was partially restored by re-expression of functional mecp2 Thus, Mecp2 is required for tnfa expression during zebrafish development and inflammation. Finally, RNA sequencing of mecp2-null embryos revealed dysregulated processes predictive for Rett syndrome phenotypes.
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Affiliation(s)
- M van der Vaart
- Department of Cellular and Molecular Medicine, University of California at San Diego, La Jolla, 92093 CA, USA
| | - O Svoboda
- Department of Cellular and Molecular Medicine, University of California at San Diego, La Jolla, 92093 CA, USA
| | - B G Weijts
- Department of Cellular and Molecular Medicine, University of California at San Diego, La Jolla, 92093 CA, USA
| | - R Espín-Palazón
- Department of Cellular and Molecular Medicine, University of California at San Diego, La Jolla, 92093 CA, USA
| | - V Sapp
- Department of Cellular and Molecular Medicine, University of California at San Diego, La Jolla, 92093 CA, USA
| | - T Pietri
- Federated Department of Biological Sciences, New Jersey Institute of Technology, Newark, 07102 NJ, USA
| | - M Bagnat
- Department of Cell Biology, Duke University, Durham, 27708 NC, USA
| | - A R Muotri
- Department of Cellular and Molecular Medicine, University of California at San Diego, La Jolla, 92093 CA, USA
- Department of Pediatrics/Rady Children's Hospital San Diego, School of Medicine, University of California San Diego, La Jolla, 92093 CA, USA
| | - D Traver
- Department of Cellular and Molecular Medicine, University of California at San Diego, La Jolla, 92093 CA, USA
- Section of Cell and Developmental Biology, Division of Biological Sciences, University of California San Diego, La Jolla, 92093 CA, USA
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Lannes N, Eppler E, Etemad S, Yotovski P, Filgueira L. Microglia at center stage: a comprehensive review about the versatile and unique residential macrophages of the central nervous system. Oncotarget 2017; 8:114393-114413. [PMID: 29371994 PMCID: PMC5768411 DOI: 10.18632/oncotarget.23106] [Citation(s) in RCA: 76] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Accepted: 11/15/2017] [Indexed: 02/07/2023] Open
Abstract
Microglia cells are the unique residential macrophages of the central nervous system (CNS). They have a special origin, as they derive from the embryonic yolk sac and enter the developing CNS at a very early stage. They play an important role during CNS development and adult homeostasis. They have a major contribution to adult neurogenesis and neuroinflammation. Thus, they participate in the pathogenesis of neurodegenerative diseases and contribute to aging. They play an important role in sustaining and breaking the blood-brain barrier. As innate immune cells, they contribute substantially to the immune response against infectious agents affecting the CNS. They play also a major role in the growth of tumours of the CNS. Microglia are consequently the key cell population linking the nervous and the immune system. This review covers all different aspects of microglia biology and pathology in a comprehensive way.
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Affiliation(s)
- Nils Lannes
- Albert Gockel, Anatomy, Department of Medicine, University of Fribourg, CH-1700 Fribourg, Switzerland
| | - Elisabeth Eppler
- Pestalozzistrasse Zo, Department of BioMedicine, University of Basel, CH-4056 Basel, Switzerland
| | - Samar Etemad
- Building 71/218 RBWH Herston, Centre for Clinical Research, The University of Queensland, QLD 4029 Brisbane, Australia
| | - Peter Yotovski
- Albert Gockel, Anatomy, Department of Medicine, University of Fribourg, CH-1700 Fribourg, Switzerland
| | - Luis Filgueira
- Albert Gockel, Anatomy, Department of Medicine, University of Fribourg, CH-1700 Fribourg, Switzerland
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Abscopal Activation of Microglia in Embryonic Fish Brain Following Targeted Irradiation with Heavy-Ion Microbeam. Int J Mol Sci 2017; 18:ijms18071428. [PMID: 28677658 PMCID: PMC5535919 DOI: 10.3390/ijms18071428] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Revised: 06/23/2017] [Accepted: 06/28/2017] [Indexed: 12/17/2022] Open
Abstract
Microglia remove apoptotic cells by phagocytosis when the central nervous system is injured in vertebrates. Ionizing irradiation (IR) induces apoptosis and microglial activation in embryonic midbrain of medaka (Oryzias latipes), where apolipoprotein E (ApoE) is upregulated in the later phase of activation of microglia In this study, we found that another microglial marker, l-plastin (lymphocyte cytosolic protein 1), was upregulated at the initial phase of the IR-induced phagocytosis when activated microglia changed their morphology and increased motility to migrate. We further conducted targeted irradiation to the embryonic midbrain using a collimated microbeam of carbon ions (250 μm diameter) and found that the l-plastin upregulation was induced only in the microglia located in the irradiated area. Then, the activated microglia might migrate outside of the irradiated area and spread through over the embryonic brain, expressing ApoE and with activated morphology, for longer than 3 days after the irradiation. These findings suggest that l-plastin and ApoE can be the biomarkers of the activated microglia in the initial and later phase, respectively, in the medaka embryonic brain and that the abscopal and persisted activation of microglia by IR irradiation could be a cause of the abscopal and/or adverse effects following irradiation.
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Smolders SMT, Swinnen N, Kessels S, Arnauts K, Smolders S, Le Bras B, Rigo JM, Legendre P, Brône B. Age-specific function of α5β1 integrin in microglial migration during early colonization of the developing mouse cortex. Glia 2017; 65:1072-1088. [PMID: 28417486 DOI: 10.1002/glia.23145] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Revised: 03/10/2017] [Accepted: 03/14/2017] [Indexed: 12/31/2022]
Abstract
Microglia, the immune cells of the central nervous system, take part in brain development and homeostasis. They derive from primitive myeloid progenitors that originate in the yolk sac and colonize the brain mainly through intensive migration. During development, microglial migration speed declines which suggests that their interaction with the microenvironment changes. However, the matrix-cell interactions allowing dispersion within the parenchyma are unknown. Therefore, we aimed to better characterize the migration behavior and to assess the role of matrix-integrin interactions during microglial migration in the embryonic brain ex vivo. We focused on microglia-fibronectin interactions mediated through the fibronectin receptor α5β1 integrin because in vitro work indirectly suggested a role for this ligand-receptor pair. Using 2-photon time-lapse microscopy on acute ex vivo embryonic brain slices, we found that migration occurs in a saltatory pattern and is developmentally regulated. Most importantly, there is an age-specific function of the α5β1 integrin during microglial cortex colonization. At embryonic day (E) 13.5, α5β1 facilitates migration while from E15.5, it inhibits migration. These results indicate a developmentally regulated function of α5β1 integrin in microglial migration during colonization of the embryonic brain.
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Affiliation(s)
- Sophie Marie-Thérèse Smolders
- UHasselt, BIOMED, Diepenbeek, Belgium.,INSERM, UMR_S 1130, CNRS, UMR 8246, Neuroscience Paris Seine, Institute of Biology Paris Seine, Paris, France.,Sorbonne Universités, UPMC Université Paris 06, UM CR18, Neuroscience Paris Seine, Paris, France
| | | | | | | | - Silke Smolders
- UHasselt, BIOMED, Diepenbeek, Belgium.,Laboratory of Neuronal Differentiation, VIB Center for the Biology of Disease, Leuven and Center for Human Genetics, KU Leuven, Leuven, Belgium
| | - Barbara Le Bras
- INSERM, UMR_S 1130, CNRS, UMR 8246, Neuroscience Paris Seine, Institute of Biology Paris Seine, Paris, France.,Sorbonne Universités, UPMC Université Paris 06, UM CR18, Neuroscience Paris Seine, Paris, France
| | | | - Pascal Legendre
- INSERM, UMR_S 1130, CNRS, UMR 8246, Neuroscience Paris Seine, Institute of Biology Paris Seine, Paris, France.,Sorbonne Universités, UPMC Université Paris 06, UM CR18, Neuroscience Paris Seine, Paris, France
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