1
|
Maes ME, Colombo G, Schoot Uiterkamp FE, Sternberg F, Venturino A, Pohl EE, Siegert S. Mitochondrial network adaptations of microglia reveal sex-specific stress response after injury and UCP2 knockout. iScience 2023; 26:107780. [PMID: 37731609 PMCID: PMC10507162 DOI: 10.1016/j.isci.2023.107780] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Revised: 08/10/2023] [Accepted: 08/28/2023] [Indexed: 09/22/2023] Open
Abstract
Mitochondrial networks remodel their connectivity, content, and subcellular localization to support optimized energy production in conditions of increased environmental or cellular stress. Microglia rely on mitochondria to respond to these stressors, however our knowledge about mitochondrial networks and their adaptations in microglia in vivo is limited. Here, we generate a mouse model that selectively labels mitochondria in microglia. We identify that mitochondrial networks are more fragmented with increased content and perinuclear localization in vitro vs. in vivo. Mitochondrial networks adapt similarly in microglia closest to the injury site after optic nerve crush. Preventing microglial UCP2 increase after injury by selective knockout induces cellular stress. This results in mitochondrial hyperfusion in male microglia, a phenotype absent in females due to circulating estrogens. Our results establish the foundation for mitochondrial network analysis of microglia in vivo, emphasizing the importance of mitochondrial-based sex effects of microglia in other pathologies.
Collapse
Affiliation(s)
- Margaret E. Maes
- Institute of Science and Technology Austria (ISTA), Am Campus 1, 3400 Klosterneuburg, Austria
| | - Gloria Colombo
- Institute of Science and Technology Austria (ISTA), Am Campus 1, 3400 Klosterneuburg, Austria
| | | | - Felix Sternberg
- Institute of Physiology, Pathophysiology and Biophysics, University of Veterinary Medicine, Veterinärplatz 1, 1210 Vienna, Austria
| | - Alessandro Venturino
- Institute of Science and Technology Austria (ISTA), Am Campus 1, 3400 Klosterneuburg, Austria
| | - Elena E. Pohl
- Institute of Physiology, Pathophysiology and Biophysics, University of Veterinary Medicine, Veterinärplatz 1, 1210 Vienna, Austria
| | - Sandra Siegert
- Institute of Science and Technology Austria (ISTA), Am Campus 1, 3400 Klosterneuburg, Austria
| |
Collapse
|
2
|
Dissing-Olesen L, Walker AJ, Feng Q, Barr HJ, Walker AC, Xie L, Wilton DK, Das I, Benowitz LI, Stevens B. FEAST: A flow cytometry-based toolkit for interrogating microglial engulfment of synaptic and myelin proteins. Nat Commun 2023; 14:6015. [PMID: 37758703 PMCID: PMC10533836 DOI: 10.1038/s41467-023-41448-7] [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: 12/09/2022] [Accepted: 09/04/2023] [Indexed: 09/29/2023] Open
Abstract
Although engulfment is a hallmark of microglia function, fully validated platforms that facilitate high-throughput quantification of this process are lacking. Here, we present FEAST (Flow cytometric Engulfment Assay for Specific Target proteins), which enables interrogation of in vivo engulfment of synaptic material by brain resident macrophages at single-cell resolution. We optimize FEAST for two different analyses: quantification of fluorescent material inside live cells and of engulfed endogenous proteins within fixed cells. To overcome false-positive engulfment signals, we introduce an approach suitable for interrogating engulfment in microglia from perfusion-fixed tissue. As a proof-of-concept for the specificity and versatility of FEAST, we examine the engulfment of synaptic proteins after optic nerve crush and of myelin in two mouse models of demyelination (treatment with cuprizone and injections of lysolecithin). We find that microglia, but not brain-border associated macrophages, engulf in these contexts. Our work underscores how FEAST can be utilized to gain critical insight into functional neuro-immune interactions that shape development, homeostasis, and disease.
Collapse
Affiliation(s)
- Lasse Dissing-Olesen
- Department of Neurology, Boston Children's Hospital, F.M. Kirby Neurobiology Center, Boston, MA, 02115, USA
- Harvard Medical School, Boston, MA, 02115, USA
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, 02139, USA
| | - Alec J Walker
- Department of Neurology, Boston Children's Hospital, F.M. Kirby Neurobiology Center, Boston, MA, 02115, USA
- Harvard Medical School, Boston, MA, 02115, USA
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, 02139, USA
| | - Qian Feng
- Department of Neurosurgery, Boston Children's Hospital, F.M. Kirby Neurobiology Center, Boston, MA, 02115, USA
| | - Helena J Barr
- Department of Neurology, Boston Children's Hospital, F.M. Kirby Neurobiology Center, Boston, MA, 02115, USA
- Harvard Medical School, Boston, MA, 02115, USA
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, 02139, USA
| | - Alicia C Walker
- Department of Neurology, Boston Children's Hospital, F.M. Kirby Neurobiology Center, Boston, MA, 02115, USA
- Harvard Medical School, Boston, MA, 02115, USA
| | - Lili Xie
- Department of Neurosurgery, Boston Children's Hospital, F.M. Kirby Neurobiology Center, Boston, MA, 02115, USA
| | - Daniel K Wilton
- Department of Neurology, Boston Children's Hospital, F.M. Kirby Neurobiology Center, Boston, MA, 02115, USA
- Harvard Medical School, Boston, MA, 02115, USA
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, 02139, USA
| | - Indrani Das
- Department of Neurology, Boston Children's Hospital, F.M. Kirby Neurobiology Center, Boston, MA, 02115, USA
- Harvard Medical School, Boston, MA, 02115, USA
| | - Larry I Benowitz
- Department of Neurosurgery, Boston Children's Hospital, F.M. Kirby Neurobiology Center, Boston, MA, 02115, USA
- Ophthalmology, Harvard Medical School, Boston, MA, 02115, USA
| | - Beth Stevens
- Department of Neurology, Boston Children's Hospital, F.M. Kirby Neurobiology Center, Boston, MA, 02115, USA.
- Harvard Medical School, Boston, MA, 02115, USA.
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, 02139, USA.
- Howard Hughes Medical Institute, Boston Children's Hospital, Boston, MA, 02115, USA.
| |
Collapse
|
3
|
Rosito M, Sanchini C, Gosti G, Moreno M, De Panfilis S, Giubettini M, Debellis D, Catalano F, Peruzzi G, Marotta R, Indrieri A, De Leonibus E, De Stefano ME, Ragozzino D, Ruocco G, Di Angelantonio S, Bartolini F. Microglia reactivity entails microtubule remodeling from acentrosomal to centrosomal arrays. Cell Rep 2023; 42:112104. [PMID: 36787220 PMCID: PMC10423306 DOI: 10.1016/j.celrep.2023.112104] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 12/02/2022] [Accepted: 01/27/2023] [Indexed: 02/15/2023] Open
Abstract
Microglia reactivity entails a large-scale remodeling of cellular geometry, but the behavior of the microtubule cytoskeleton during these changes remains unexplored. Here we show that activated microglia provide an example of microtubule reorganization from a non-centrosomal array of parallel and stable microtubules to a radial array of more dynamic microtubules. While in the homeostatic state, microglia nucleate microtubules at Golgi outposts, and activating signaling induces recruitment of nucleating material nearby the centrosome, a process inhibited by microtubule stabilization. Our results demonstrate that a hallmark of microglia reactivity is a striking remodeling of the microtubule cytoskeleton and suggest that while pericentrosomal microtubule nucleation may serve as a distinct marker of microglia activation, inhibition of microtubule dynamics may provide a different strategy to reduce microglia reactivity in inflammatory disease.
Collapse
Affiliation(s)
- Maria Rosito
- Center for Life Nano- & Neuro-Science, Istituto Italiano di Tecnologia, 00161 Rome, Italy; Department of Physiology and Pharmacology, Sapienza University, 00185 Rome, Italy
| | - Caterina Sanchini
- Center for Life Nano- & Neuro-Science, Istituto Italiano di Tecnologia, 00161 Rome, Italy; Department of Physiology and Pharmacology, Sapienza University, 00185 Rome, Italy
| | - Giorgio Gosti
- Center for Life Nano- & Neuro-Science, Istituto Italiano di Tecnologia, 00161 Rome, Italy; Soft and Living Matter Laboratory, Institute of Nanotechnology, Consiglio Nazionale delle Ricerche, 00185 Rome, Italy
| | - Manuela Moreno
- Department of Physiology and Pharmacology, Sapienza University, 00185 Rome, Italy
| | - Simone De Panfilis
- Center for Life Nano- & Neuro-Science, Istituto Italiano di Tecnologia, 00161 Rome, Italy
| | | | - Doriana Debellis
- Electron Microscopy Facility, Istituto Italiano di Tecnologia, 16163 Genova, Italy
| | - Federico Catalano
- Electron Microscopy Facility, Istituto Italiano di Tecnologia, 16163 Genova, Italy
| | - Giovanna Peruzzi
- Center for Life Nano- & Neuro-Science, Istituto Italiano di Tecnologia, 00161 Rome, Italy
| | - Roberto Marotta
- Electron Microscopy Facility, Istituto Italiano di Tecnologia, 16163 Genova, Italy
| | - Alessia Indrieri
- Telethon Institute of Genetics and Medicine, 80078 Pozzuoli, Italy; Institute for Genetic and Biomedical Research, National Research Council, 20090 Milan, Italy
| | - Elvira De Leonibus
- Telethon Institute of Genetics and Medicine, 80078 Pozzuoli, Italy; Institute of Biochemistry and Cellular Biology, National Research Council, 00015 Rome, Italy
| | - Maria Egle De Stefano
- Department of Biology and Biotechnologies "Charles Darwin", Sapienza University, 00185 Rome, Italy
| | - Davide Ragozzino
- Department of Physiology and Pharmacology, Sapienza University, 00185 Rome, Italy; Santa Lucia Foundation (IRCCS Fondazione Santa Lucia), 00179 Rome, Italy
| | - Giancarlo Ruocco
- Center for Life Nano- & Neuro-Science, Istituto Italiano di Tecnologia, 00161 Rome, Italy; Department of Physics, Sapienza University, 00185 Rome, Italy
| | - Silvia Di Angelantonio
- Center for Life Nano- & Neuro-Science, Istituto Italiano di Tecnologia, 00161 Rome, Italy; Department of Physiology and Pharmacology, Sapienza University, 00185 Rome, Italy; D-Tails s.r.l, 00165 Rome, Italy.
| | - Francesca Bartolini
- Department of Pathology and Cell Biology, Columbia University Medical Center, New York, NY 10032, USA.
| |
Collapse
|
4
|
Bosch LFP, Kierdorf K. The Shape of μ—How Morphological Analyses Shape the Study of Microglia. Front Cell Neurosci 2022; 16:942462. [PMID: 35846562 PMCID: PMC9276927 DOI: 10.3389/fncel.2022.942462] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Accepted: 06/13/2022] [Indexed: 11/14/2022] Open
Abstract
Microglia, the innate immune cells of the CNS parenchyma, serve as the first line of defense in a myriad of neurodevelopmental, neurodegenerative, and neuroinflammatory conditions. In response to the peripheral inflammation, circulating mediators, and other external signals that are produced by these conditions, microglia dynamically employ different transcriptional programs as well as morphological adaptations to maintain homeostasis. To understand these cells’ function, the field has established a number of essential analysis approaches, such as gene expression, cell quantification, and morphological reconstruction. Although high-throughput approaches are becoming commonplace in regard to other types of analyses (e.g., single-cell scRNA-seq), a similar standard for morphological reconstruction has yet to be established. In this review, we offer an overview of microglial morphological analysis methods, exploring the advantages and disadvantages of each, highlighting a number of key studies, and emphasizing how morphological analysis has significantly contributed to our understanding of microglial function in the CNS parenchyma. In doing so, we advocate for the use of unbiased, automated morphological reconstruction approaches in future studies, in order to capitalize on the valuable information embedded in the cellular structures microglia inhabit.
Collapse
Affiliation(s)
- Lance Fredrick Pahutan Bosch
- Institute of Neuropathology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Katrin Kierdorf
- Institute of Neuropathology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Center for Basics in NeuroModulation (NeuroModulBasics), Faculty of Medicine, University of Freiburg, Freiburg, Germany
- CIBSS–Centre for Integrative Biological Signalling Studies, University of Freiburg, Freiburg, Germany
- *Correspondence: Katrin Kierdorf,
| |
Collapse
|
5
|
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.
Collapse
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
| |
Collapse
|
6
|
Cockram TOJ, Dundee JM, Popescu AS, Brown GC. The Phagocytic Code Regulating Phagocytosis of Mammalian Cells. Front Immunol 2021; 12:629979. [PMID: 34177884 PMCID: PMC8220072 DOI: 10.3389/fimmu.2021.629979] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Accepted: 05/18/2021] [Indexed: 01/21/2023] Open
Abstract
Mammalian phagocytes can phagocytose (i.e. eat) other mammalian cells in the body if they display certain signals, and this phagocytosis plays fundamental roles in development, cell turnover, tissue homeostasis and disease prevention. To phagocytose the correct cells, phagocytes must discriminate which cells to eat using a 'phagocytic code' - a set of over 50 known phagocytic signals determining whether a cell is eaten or not - comprising find-me signals, eat-me signals, don't-eat-me signals and opsonins. Most opsonins require binding to eat-me signals - for example, the opsonins galectin-3, calreticulin and C1q bind asialoglycan eat-me signals on target cells - to induce phagocytosis. Some proteins act as 'self-opsonins', while others are 'negative opsonins' or 'phagocyte suppressants', inhibiting phagocytosis. We review known phagocytic signals here, both established and novel, and how they integrate to regulate phagocytosis of several mammalian targets - including excess cells in development, senescent and aged cells, infected cells, cancer cells, dead or dying cells, cell debris and neuronal synapses. Understanding the phagocytic code, and how it goes wrong, may enable novel therapies for multiple pathologies with too much or too little phagocytosis, such as: infectious disease, cancer, neurodegeneration, psychiatric disease, cardiovascular disease, ageing and auto-immune disease.
Collapse
Affiliation(s)
| | | | | | - Guy C. Brown
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| |
Collapse
|
7
|
Gipson CD, Rawls S, Scofield MD, Siemsen BM, Bondy EO, Maher EE. Interactions of neuroimmune signaling and glutamate plasticity in addiction. J Neuroinflammation 2021; 18:56. [PMID: 33612110 PMCID: PMC7897396 DOI: 10.1186/s12974-021-02072-8] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Accepted: 01/05/2021] [Indexed: 02/28/2023] Open
Abstract
Chronic use of drugs of abuse affects neuroimmune signaling; however, there are still many open questions regarding the interactions between neuroimmune mechanisms and substance use disorders (SUDs). Further, chronic use of drugs of abuse can induce glutamatergic changes in the brain, but the relationship between the glutamate system and neuroimmune signaling in addiction is not well understood. Therefore, the purpose of this review is to bring into focus the role of neuroimmune signaling and its interactions with the glutamate system following chronic drug use, and how this may guide pharmacotherapeutic treatment strategies for SUDs. In this review, we first describe neuroimmune mechanisms that may be linked to aberrant glutamate signaling in addiction. We focus specifically on the nuclear factor-kappa B (NF-κB) pathway, a potentially important neuroimmune mechanism that may be a key player in driving drug-seeking behavior. We highlight the importance of astroglial-microglial crosstalk, and how this interacts with known glutamatergic dysregulations in addiction. Then, we describe the importance of studying non-neuronal cells with unprecedented precision because understanding structure-function relationships in these cells is critical in understanding their role in addiction neurobiology. Here we propose a working model of neuroimmune-glutamate interactions that underlie drug use motivation, which we argue may aid strategies for small molecule drug development to treat substance use disorders. Together, the synthesis of this review shows that interactions between glutamate and neuroimmune signaling may play an important and understudied role in addiction processes and may be critical in developing more efficacious pharmacotherapies to treat SUDs.
Collapse
Affiliation(s)
- Cassandra D Gipson
- Department of Family and Community Medicine, University of Kentucky, 741 S. Limestone, BBSRB, Room 363, Lexington, KY, 40536-0509, USA.
| | - Scott Rawls
- Department of Pharmacology, Lewis Katz School of Medicine, Temple University, Philadelphia, USA
| | - Michael D Scofield
- Department of Anesthesiology, Medical University of South Carolina, Charleston, USA
- Department of Neuroscience, Medical University of South Carolina, Charleston, USA
| | - Benjamin M Siemsen
- Department of Anesthesiology, Medical University of South Carolina, Charleston, USA
| | - Emma O Bondy
- Department of Family and Community Medicine, University of Kentucky, 741 S. Limestone, BBSRB, Room 363, Lexington, KY, 40536-0509, USA
| | - Erin E Maher
- Department of Family and Community Medicine, University of Kentucky, 741 S. Limestone, BBSRB, Room 363, Lexington, KY, 40536-0509, USA
| |
Collapse
|
8
|
Carrier M, Robert MÈ, González Ibáñez F, Desjardins M, Tremblay MÈ. Imaging the Neuroimmune Dynamics Across Space and Time. Front Neurosci 2020; 14:903. [PMID: 33071723 PMCID: PMC7539119 DOI: 10.3389/fnins.2020.00903] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Accepted: 08/04/2020] [Indexed: 12/13/2022] Open
Abstract
The immune system is essential for maintaining homeostasis, as well as promoting growth and healing throughout the brain and body. Considering that immune cells respond rapidly to changes in their microenvironment, they are very difficult to study without affecting their structure and function. The advancement of non-invasive imaging methods greatly contributed to elucidating the physiological roles performed by immune cells in the brain across stages of the lifespan and contexts of health and disease. For instance, techniques like two-photon in vivo microscopy were pivotal for studying microglial functional dynamics in the healthy brain. Through these observations, their interactions with neurons, astrocytes, blood vessels and synapses were uncovered. High-resolution electron microscopy with immunostaining and 3D-reconstruction, as well as super-resolution fluorescence microscopy, provided complementary insights by revealing microglial interventions at synapses (phagocytosis, trogocytosis, synaptic stripping, etc.). In addition, serial block-face scanning electron microscopy has provided the first 3D reconstruction of a microglial cell at nanoscale resolution. This review will discuss the technical toolbox that currently allows to study microglia and other immune cells in the brain, as well as introduce emerging methods that were developed and could be used to increase the spatial and temporal resolution of neuroimmune imaging. A special attention will also be placed on positron emission tomography and the development of selective functional radiotracers for microglia and peripheral macrophages, considering their strong potential for research translation between animals and humans, notably when paired with other imaging modalities such as magnetic resonance imaging.
Collapse
Affiliation(s)
- Micaël Carrier
- Axe Neurosciences, Centre de Recherche du CHU de Québec, Université Laval, Québec City, QC, Canada
| | - Marie-Ève Robert
- Axe Neurosciences, Centre de Recherche du CHU de Québec, Université Laval, Québec City, QC, Canada
| | - Fernando González Ibáñez
- Axe Neurosciences, Centre de Recherche du CHU de Québec, Université Laval, Québec City, QC, Canada
| | - Michèle Desjardins
- Axe Oncologie, Centre de Recherche du CHU de Québec, Université Laval, Québec City, QC, Canada
- Department of Physics, Physical Engineering and Optics, Université Laval, Québec City, QC, Canada
| | - Marie-Ève Tremblay
- Axe Neurosciences, Centre de Recherche du CHU de Québec, Université Laval, Québec City, QC, Canada
- Department of Molecular Medicine, Université Laval, Québec City, QC, Canada
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
| |
Collapse
|
9
|
Bernier LP, Bohlen CJ, York EM, Choi HB, Kamyabi A, Dissing-Olesen L, Hefendehl JK, Collins HY, Stevens B, Barres BA, MacVicar BA. Nanoscale Surveillance of the Brain by Microglia via cAMP-Regulated Filopodia. Cell Rep 2020; 27:2895-2908.e4. [PMID: 31167136 DOI: 10.1016/j.celrep.2019.05.010] [Citation(s) in RCA: 125] [Impact Index Per Article: 31.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Revised: 03/14/2019] [Accepted: 04/30/2019] [Indexed: 02/07/2023] Open
Abstract
Microglia, the brain's immune cells, maintain homeostasis and sense pathological changes by continuously surveying the parenchyma with highly motile large processes. Here, we demonstrate that microglia also use thin actin-dependent filopodia that allow fast nanoscale sensing within discrete regions. Filopodia are distinct from large processes by their size, speed, and regulation mechanism. Increasing cyclic AMP (cAMP) by activating norepinephrine Gs-coupled receptors, applying nitric oxide, or inhibiting phosphodiesterases rapidly increases filopodia but collapses large processes. Alternatively, Gi-coupled P2Y12 receptor activation collapses filopodia but triggers large processes extension with bulbous tips. Similar control of cytoskeletal dynamics and microglial morphology by cAMP is observed in ramified primary microglia, suggesting that filopodia are intrinsically generated sensing structures. Therefore, nanoscale surveillance of brain parenchyma by microglia requires localized cAMP increases that drive filopodia formation. Shifting intracellular cAMP levels controls the polarity of microglial responses to changes in brain homeostasis and alters the scale of immunosurveillance.
Collapse
Affiliation(s)
- Louis-Philippe Bernier
- University of British Columbia, Djavad Mowafaghian Centre for Brain Health, Vancouver, BC V6T 1Z3, Canada.
| | - Christopher J Bohlen
- Stanford University School of Medicine, Department of Neurobiology, Stanford, CA 94305, USA
| | - Elisa M York
- University of British Columbia, Djavad Mowafaghian Centre for Brain Health, Vancouver, BC V6T 1Z3, Canada
| | - Hyun B Choi
- University of British Columbia, Djavad Mowafaghian Centre for Brain Health, Vancouver, BC V6T 1Z3, Canada
| | - Alireza Kamyabi
- University of British Columbia, Djavad Mowafaghian Centre for Brain Health, Vancouver, BC V6T 1Z3, Canada
| | - Lasse Dissing-Olesen
- University of British Columbia, Djavad Mowafaghian Centre for Brain Health, Vancouver, BC V6T 1Z3, Canada; F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School Boston, MA 02115, USA
| | - Jasmin K Hefendehl
- University of British Columbia, Djavad Mowafaghian Centre for Brain Health, Vancouver, BC V6T 1Z3, Canada
| | - Hannah Y Collins
- Stanford University School of Medicine, Department of Neurobiology, Stanford, CA 94305, USA
| | - Beth Stevens
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School Boston, MA 02115, USA
| | - Ben A Barres
- Stanford University School of Medicine, Department of Neurobiology, Stanford, CA 94305, USA
| | - Brian A MacVicar
- University of British Columbia, Djavad Mowafaghian Centre for Brain Health, Vancouver, BC V6T 1Z3, Canada.
| |
Collapse
|
10
|
Matejuk A, Ransohoff RM. Crosstalk Between Astrocytes and Microglia: An Overview. Front Immunol 2020; 11:1416. [PMID: 32765501 PMCID: PMC7378357 DOI: 10.3389/fimmu.2020.01416] [Citation(s) in RCA: 210] [Impact Index Per Article: 52.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Accepted: 06/02/2020] [Indexed: 12/19/2022] Open
Abstract
Based on discoveries enabled by new technologies and analysis using novel computational tools, neuroscience can be re-conceived in terms of information exchange in dense networks of intercellular connections rather than in the context of individual populations, such as glia or neurons. Cross-talk between neurons and microglia or astrocytes has been addressed, however, the manner in which non-neuronal cells communicate and interact remains less well-understood. We review this intriguing crosstalk among CNS cells, focusing on astrocytes and microglia and how it contributes to brain development and neurodegenerative diseases. The goal of studying these intercellular communications is to promote our ability to combat incurable neurological disorders.
Collapse
Affiliation(s)
- Agata Matejuk
- Department of Immunology, Collegium Medicum, University of Zielona Góra, Zielona Góra, Poland
| | - Richard M Ransohoff
- Third Rock Ventures, Boston, MA, United States.,Department of Cell Biology, Harvard Medical School, Boston, MA, United States
| |
Collapse
|
11
|
Savage JC, Carrier M, Tremblay MÈ. Morphology of Microglia Across Contexts of Health and Disease. Methods Mol Biol 2019; 2034:13-26. [PMID: 31392674 DOI: 10.1007/978-1-4939-9658-2_2] [Citation(s) in RCA: 94] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Microglia, the brain's resident macrophages, are incredibly plastic and dynamic cells. In this chapter, we aim to describe and classify the many morphological changes they can display in normal development, aging, and disease. Although microglia in healthy adult brain tissue are often ramified with small somas, they can undergo massive and rapid morphological shifts in response to stimuli, becoming amoeboid or hypertrophic. Older animals occasionally contain dystrophic, senescent, and gitter cell-like microglia, and brain injury can be accompanied by an increase in rod cells. By a careful study of microglial morphology, coupled with ultrastructural insights gleaned using electron microscopy, insights can be provided into the functions performed by these various morphological phenotypes.
Collapse
Affiliation(s)
- Julie C Savage
- Axe Neurosciences, Centre de Recherche du CHU de Québec-Université Laval, Québec, QC, Canada
| | - Micaël Carrier
- Axe Neurosciences, Centre de Recherche du CHU de Québec-Université Laval, Québec, QC, Canada
| | - Marie-Ève Tremblay
- Axe Neurosciences, Centre de Recherche du CHU de Québec-Université Laval, Québec, QC, Canada. .,Département de Médecine Moléculaire, Faculté de Médecine, Université Laval, Québec, QC, Canada.
| |
Collapse
|