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Alberto AVP, Ferreira NCDS, Bonavita AGC, Nihei OK, de Farias FP, Bisaggio RDC, de Albuquerque C, Savino W, Coutinho‐Silva R, Persechini PM, Alves LA. Physiologic roles of P2 receptors in leukocytes. J Leukoc Biol 2022; 112:983-1012. [PMID: 35837975 PMCID: PMC9796137 DOI: 10.1002/jlb.2ru0421-226rr] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2021] [Revised: 06/13/2022] [Indexed: 01/01/2023] Open
Abstract
Since their discovery in the 1970s, purinergic receptors have been shown to play key roles in a wide variety of biologic systems and cell types. In the immune system, purinergic receptors participate in innate immunity and in the modulation of the adaptive immune response. In particular, P2 receptors, which respond to extracellular nucleotides, are widely expressed on leukocytes, causing the release of cytokines and chemokines and the formation of inflammatory mediators, and inducing phagocytosis, degranulation, and cell death. The activity of these receptors is regulated by ectonucleotidases-expressed in these same cell types-which regulate the availability of nucleotides in the extracellular environment. In this article, we review the characteristics of the main purinergic receptor subtypes present in the immune system, focusing on the P2 family. In addition, we describe the physiologic roles of the P2 receptors already identified in leukocytes and how they can positively or negatively modulate the development of infectious diseases, inflammation, and pain.
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Affiliation(s)
- Anael Viana Pinto Alberto
- Laboratory of Cellular Communication, Oswaldo Cruz InstituteOswaldo Cruz FoundationRio de JaneiroRJBrazil
| | | | | | - Oscar Kenji Nihei
- Center of Education and LetterState University of the West of ParanáFoz do IguaçuPRBrazil
| | | | - Rodrigo da Cunha Bisaggio
- Laboratory of Cellular Communication, Oswaldo Cruz InstituteOswaldo Cruz FoundationRio de JaneiroRJBrazil,Federal Institute of Education, Science, and Technology of Rio de JaneiroRio de JaneiroRJBrazil
| | | | - Wilson Savino
- Laboratory on Thymus Research, Oswaldo Cruz InstituteOswaldo Cruz FoundationRio de JaneiroRJBrazil,Brazilian National Institute of Science and Technology on NeuroimmunomodulationRio de Janeiro Research Network on NeuroinflammationRio de JaneiroRJBrazil
| | - Robson Coutinho‐Silva
- Laboratory of Immunophysiology, Carlos Chagas Filho Biophysics InstituteFederal University of Rio de JaneiroRio de JaneiroRJBrazil
| | - Pedro Muanis Persechini
- Laboratory of Immunobiophysics, Carlos Chagas Filho Biophysics InstituteFederal University of Rio de JaneiroRio de JaneiroRJBrazil
| | - Luiz Anastacio Alves
- Laboratory of Cellular Communication, Oswaldo Cruz InstituteOswaldo Cruz FoundationRio de JaneiroRJBrazil
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2
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Iring A, Tóth A, Baranyi M, Otrokocsi L, Módis LV, Gölöncsér F, Varga B, Hortobágyi T, Bereczki D, Dénes Á, Sperlágh B. The dualistic role of the purinergic P2Y12-receptor in an in vivo model of Parkinson's disease: Signalling pathway and novel therapeutic targets. Pharmacol Res 2022; 176:106045. [PMID: 34968684 DOI: 10.1016/j.phrs.2021.106045] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Revised: 12/09/2021] [Accepted: 12/23/2021] [Indexed: 10/19/2022]
Abstract
Parkinson's disease (PD) is a chronic, progressive neurodegenerative condition; characterized with the degeneration of the nigrostriatal dopaminergic pathway and neuroinflammation. During PD progression, microglia, the resident immune cells in the central nervous system (CNS) display altered activity, but their role in maintaining PD development has remained unclear to date. The purinergic P2Y12-receptor (P2Y12R), which is expressed on the microglia in the CNS has been shown to regulate microglial activity and responses; however, the function of the P2Y12R in PD is unknown. Here we show that MPTP-induced PD symptoms in mice are associated with marked neuroinflammatory changes and P2Y12R contribute to the activation of microglia and progression of the disease. Surprisingly, while pharmacological or genetic targeting of the P2Y12R augments acute mortality in MPTP-treated mice, these interventions protect against the neurodegenerative cell loss and the development of neuroinflammation in vivo. Pharmacological inhibition of receptors during disease development reverses the symptoms of PD and halts disease progression. We found that P2Y12R regulates ROCK and p38 MAPK activity and control cytokine production. Our principal finding is that the receptor has a dualistic role in PD: functional P2Y12Rs are essential to initiate a protective inflammatory response, since the lack of the receptor leads to reduced survival; however, at later stages of neurodegeneration, P2Y12Rs are apparently responsible for maintaining the activated state of microglia and stimulating pro-inflammatory cytokine response. Understanding protective and detrimental P2Y12R-mediated actions in the CNS may reveal novel approaches to control neuroinflammation and modify disease progression in PD.
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Affiliation(s)
- András Iring
- Laboratory of Molecular Pharmacology, Institute of Experimental Medicine, 1083 Budapest, Hungary
| | - Adrián Tóth
- Laboratory of Molecular Pharmacology, Institute of Experimental Medicine, 1083 Budapest, Hungary; János Szentágothai School of Neurosciences, Semmelweis University School of Ph.D. Studies, 1085 Budapest, Hungary; Department of Neurology, Faculty of Medicine, Semmelweis University, 1083 Budapest, Hungary
| | - Mária Baranyi
- Laboratory of Molecular Pharmacology, Institute of Experimental Medicine, 1083 Budapest, Hungary
| | - Lilla Otrokocsi
- Laboratory of Molecular Pharmacology, Institute of Experimental Medicine, 1083 Budapest, Hungary
| | - László V Módis
- MTA-DE Cerebrovascular and Neurodegenerative Research Group, Department of Neurology, University of Debrecen, 4032 Debrecen, Hungary
| | - Flóra Gölöncsér
- Laboratory of Molecular Pharmacology, Institute of Experimental Medicine, 1083 Budapest, Hungary
| | - Bernadett Varga
- Laboratory of Molecular Pharmacology, Institute of Experimental Medicine, 1083 Budapest, Hungary; János Szentágothai School of Neurosciences, Semmelweis University School of Ph.D. Studies, 1085 Budapest, Hungary
| | - Tibor Hortobágyi
- MTA-DE Cerebrovascular and Neurodegenerative Research Group, Department of Neurology, University of Debrecen, 4032 Debrecen, Hungary; Institute of Pathology, Faculty of Medicine, University of Szeged, 6725 Szeged, Hungary; Department of Old Age Psychiatry, Institute of Psychiatry Psychology and Neuroscience, King's College London, London SE5 8AF, UK; Centre for Age-Related Medicine, SESAM, Stavanger University Hospital, 4011 Stavanger, Norway
| | - Dániel Bereczki
- Department of Neurology, Faculty of Medicine, Semmelweis University, 1083 Budapest, Hungary
| | - Ádám Dénes
- Momentum Laboratory of Neuroimmunology, Institute of Experimental Medicine, 1083 Budapest, Hungary
| | - Beáta Sperlágh
- Laboratory of Molecular Pharmacology, Institute of Experimental Medicine, 1083 Budapest, Hungary; János Szentágothai School of Neurosciences, Semmelweis University School of Ph.D. Studies, 1085 Budapest, Hungary.
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3
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Zahiri D, Burow P, Großmann C, Müller CE, Klapperstück M, Markwardt F. Sphingosine-1-phosphate induces migration of microglial cells via activation of volume-sensitive anion channels, ATP secretion and activation of purinergic receptors. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2020; 1868:118915. [PMID: 33271273 DOI: 10.1016/j.bbamcr.2020.118915] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 11/20/2020] [Accepted: 11/24/2020] [Indexed: 12/17/2022]
Abstract
Microglia cells are versatile players coordinating inflammatory and regenerative processes in the central nervous system in which sphingosine-1-phosphate (S1P)-mediated migration is essential. We investigated the involved signaling cascade by means of voltage clamp, measurement of ATP secretion, and wound healing assay in murine microglial BV-2 cells. S1P and extracellular hypoosmolar solution evoked an anion conductance of the cell membrane. The corresponding ion currents were inhibited by intracellular hypoosmolar solution and by the anion channel antagonists NPPB, tamoxifen, and carbenoxolone, pointing to the activation of volume-regulated anion channels (VRAC). The knockdown by siRNA indicates the involvement of LRRC8A subunits. The S1PR1-antagonist W123 and pertussis-toxin prevented the S1P-induced currents, showing the involvement of the Gi-protein-coupled S1P receptor 1 (S1PR1). Furthermore, S1P and hypoosmolar extracellular solution induced an increase of ATP levels in the supernatants of BV-2 cells, which was inhibited by NPPB, tamoxifen, and W123. S1P, ATP, and ADP stimulated cell migration into the scratch area. The inhibition of S1PR1 and the downstream Gi proteins hampered cell migration. Antagonists of VRAC were also able to diminish the migration of BV-2 cells. Furthermore, direct inhibition of ATP-gated P2X4 or P2X7 receptors or ADP-stimulated P2Y12 receptors blocked the stimulating effects of S1P on BV-2 cell migration. We conclude that there is an interaction between S1P receptors and purinergic receptors mediated by an S1P-induced ATP release via VRAC and that the amount of released ATP is capable of stimulating cell migration of BV-2 microglia cells via activation of P2X4, P2X7, and P2Y12 receptors.
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Affiliation(s)
- Danyal Zahiri
- Julius-Bernstein-Institute for Physiology, Martin-Luther-University Halle, Magdeburger Straße 6, D-06097 Halle/Saale, Germany
| | - Philipp Burow
- Julius-Bernstein-Institute for Physiology, Martin-Luther-University Halle, Magdeburger Straße 6, D-06097 Halle/Saale, Germany
| | - Claudia Großmann
- Julius-Bernstein-Institute for Physiology, Martin-Luther-University Halle, Magdeburger Straße 6, D-06097 Halle/Saale, Germany
| | - Christa E Müller
- Pharmaceutical Institute, Pharmaceutical & Medicinal Chemistry, University of Bonn, Germany
| | - Manuela Klapperstück
- Julius-Bernstein-Institute for Physiology, Martin-Luther-University Halle, Magdeburger Straße 6, D-06097 Halle/Saale, Germany
| | - Fritz Markwardt
- Julius-Bernstein-Institute for Physiology, Martin-Luther-University Halle, Magdeburger Straße 6, D-06097 Halle/Saale, Germany.
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4
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Lesion stage-dependent causes for impaired remyelination in MS. Acta Neuropathol 2020; 140:359-375. [PMID: 32710244 PMCID: PMC7424408 DOI: 10.1007/s00401-020-02189-9] [Citation(s) in RCA: 54] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 06/16/2020] [Accepted: 06/28/2020] [Indexed: 02/08/2023]
Abstract
Multiple sclerosis (MS) is the most frequent demyelinating disease and a leading cause for disability in young adults. Despite significant advances in immunotherapies in recent years, disease progression still cannot be prevented. Remyelination, meaning the formation of new myelin sheaths after a demyelinating event, can fail in MS lesions. Impaired differentiation of progenitor cells into myelinating oligodendrocytes may contribute to remyelination failure and, therefore, the development of pharmacological approaches which promote oligodendroglial differentiation and by that remyelination, represents a promising new treatment approach. However, this generally accepted concept has been challenged recently. To further understand mechanisms contributing to remyelination failure in MS, we combined detailed histological analyses assessing oligodendroglial cell numbers, presence of remyelination as well as the inflammatory environment in different MS lesion types in white matter with in vitro experiments using induced-pluripotent stem cell (iPSC)-derived oligodendrocytes (hiOL) and supernatants from polarized human microglia. Our findings suggest that there are multiple reasons for remyelination failure in MS which are dependent on lesion stage. These include lack of myelin sheath formation despite the presence of mature oligodendrocytes in a subset of active lesions as well as oligodendroglial loss and a hostile tissue environment in mixed active/inactive lesions. Therefore, we conclude that better in vivo and in vitro models which mimic the pathological hallmarks of the different MS lesion types are required for the successful development of remyelination promoting drugs.
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5
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Venkateswarlu K, Suman G, Dhyani V, Swain S, Giri L, Samavedi S. Three‐dimensional imaging and quantification of real‐time cytosolic calcium oscillations in microglial cells cultured on electrospun matrices using laser scanning confocal microscopy. Biotechnol Bioeng 2020; 117:3108-3123. [DOI: 10.1002/bit.27465] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2020] [Revised: 05/24/2020] [Accepted: 06/16/2020] [Indexed: 12/28/2022]
Affiliation(s)
- Kojja Venkateswarlu
- Department of Chemical Engineering Indian Institute of Technology Hyderabad Sangareddy Telangana India
| | - Gare Suman
- Department of Chemical Engineering Indian Institute of Technology Hyderabad Sangareddy Telangana India
| | - Vaibhav Dhyani
- Department of Chemical Engineering Indian Institute of Technology Hyderabad Sangareddy Telangana India
| | - Sarpras Swain
- Department of Chemical Engineering Indian Institute of Technology Hyderabad Sangareddy Telangana India
| | - Lopamudra Giri
- Department of Chemical Engineering Indian Institute of Technology Hyderabad Sangareddy Telangana India
| | - Satyavrata Samavedi
- Department of Chemical Engineering Indian Institute of Technology Hyderabad Sangareddy Telangana India
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Konttinen H, Cabral-da-Silva MEC, Ohtonen S, Wojciechowski S, Shakirzyanova A, Caligola S, Giugno R, Ishchenko Y, Hernández D, Fazaludeen MF, Eamen S, Budia MG, Fagerlund I, Scoyni F, Korhonen P, Huber N, Haapasalo A, Hewitt AW, Vickers J, Smith GC, Oksanen M, Graff C, Kanninen KM, Lehtonen S, Propson N, Schwartz MP, Pébay A, Koistinaho J, Ooi L, Malm T. PSEN1ΔE9, APPswe, and APOE4 Confer Disparate Phenotypes in Human iPSC-Derived Microglia. Stem Cell Reports 2019; 13:669-683. [PMID: 31522977 PMCID: PMC6829767 DOI: 10.1016/j.stemcr.2019.08.004] [Citation(s) in RCA: 107] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Revised: 08/14/2019] [Accepted: 08/15/2019] [Indexed: 12/20/2022] Open
Abstract
Here we elucidate the effect of Alzheimer disease (AD)-predisposing genetic backgrounds, APOE4, PSEN1ΔE9, and APPswe, on functionality of human microglia-like cells (iMGLs). We present a physiologically relevant high-yield protocol for producing iMGLs from induced pluripotent stem cells. Differentiation is directed with small molecules through primitive erythromyeloid progenitors to re-create microglial ontogeny from yolk sac. The iMGLs express microglial signature genes and respond to ADP with intracellular Ca2+ release distinguishing them from macrophages. Using 16 iPSC lines from healthy donors, AD patients and isogenic controls, we reveal that the APOE4 genotype has a profound impact on several aspects of microglial functionality, whereas PSEN1ΔE9 and APPswe mutations trigger minor alterations. The APOE4 genotype impairs phagocytosis, migration, and metabolic activity of iMGLs but exacerbates their cytokine secretion. This indicates that APOE4 iMGLs are fundamentally unable to mount normal microglial functionality in AD. APOE4 genotype has a profound impact on several functions of microglia-like cells Inflammatory responses are aggravated in cells with APOE4 genotype Metabolism, phagocytosis, and migration are decreased in APOE4 microglia-like cells Familial mutations APPswe and PSEN1ΔE9 have only minor effects on functionality
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Affiliation(s)
- Henna Konttinen
- A.I.Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio 70211, Finland
| | - Mauricio E Castro Cabral-da-Silva
- School of Chemistry and Molecular Bioscience, Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, NSW 2522, Australia
| | - Sohvi Ohtonen
- A.I.Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio 70211, Finland
| | - Sara Wojciechowski
- A.I.Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio 70211, Finland
| | - Anastasia Shakirzyanova
- A.I.Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio 70211, Finland
| | - Simone Caligola
- Department of Computer Science, University of Verona, Verona 37134, Italy
| | - Rosalba Giugno
- Department of Computer Science, University of Verona, Verona 37134, Italy
| | - Yevheniia Ishchenko
- A.I.Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio 70211, Finland
| | - Damián Hernández
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, VIC 3002, Australia; Department of Surgery, the University of Melbourne, Melbourne, VIC 3002, Australia; Department of Anatomy and Neuroscience, the University of Melbourne, Melbourne, VIC 3002, Australia
| | | | - Shaila Eamen
- A.I.Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio 70211, Finland
| | - Mireia Gómez Budia
- A.I.Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio 70211, Finland
| | - Ilkka Fagerlund
- A.I.Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio 70211, Finland
| | - Flavia Scoyni
- A.I.Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio 70211, Finland
| | - Paula Korhonen
- A.I.Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio 70211, Finland
| | - Nadine Huber
- A.I.Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio 70211, Finland
| | - Annakaisa Haapasalo
- A.I.Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio 70211, Finland
| | - Alex W Hewitt
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, VIC 3002, Australia; Department of Surgery, the University of Melbourne, Melbourne, VIC 3002, Australia; School of Medicine, Menzies Institute for Medical Research, University of Tasmania, Hobart, VIC 7005, Australia
| | - James Vickers
- Wicking Dementia Research and Education Centre, University of Tasmania, Hobart, TAS 7000, Australia
| | - Grady C Smith
- School of Chemistry and Molecular Bioscience, Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, NSW 2522, Australia
| | - Minna Oksanen
- A.I.Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio 70211, Finland
| | - Caroline Graff
- Department NVS, Division of Neurogeriatrics, Karolinka Institutet, Stockholm 17176, Sweden; Theme Aging, Genetics Unit, Karolinska University Hospital-Solna, Stockholm 17176, Sweden
| | - Katja M Kanninen
- A.I.Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio 70211, Finland
| | - Sarka Lehtonen
- A.I.Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio 70211, Finland
| | - Nicholas Propson
- Department of Molecular and Cell Biology and the Huffington Center on Aging, Baylor College of Medicine, Houston, TX 77030, USA
| | - Michael P Schwartz
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Alice Pébay
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, VIC 3002, Australia; Department of Surgery, the University of Melbourne, Melbourne, VIC 3002, Australia; Department of Anatomy and Neuroscience, the University of Melbourne, Melbourne, VIC 3002, Australia
| | - Jari Koistinaho
- A.I.Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio 70211, Finland; Neuroscience Center, University of Helsinki, Helsinki 00014, Finland
| | - Lezanne Ooi
- School of Chemistry and Molecular Bioscience, Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, NSW 2522, Australia
| | - Tarja Malm
- A.I.Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio 70211, Finland.
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7
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Human microglia regional heterogeneity and phenotypes determined by multiplexed single-cell mass cytometry. Nat Neurosci 2018; 22:78-90. [DOI: 10.1038/s41593-018-0290-2] [Citation(s) in RCA: 209] [Impact Index Per Article: 34.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Accepted: 11/13/2018] [Indexed: 11/08/2022]
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8
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Owen DR, Narayan N, Wells L, Healy L, Smyth E, Rabiner EA, Galloway D, Williams JB, Lehr J, Mandhair H, Peferoen LA, Taylor PC, Amor S, Antel JP, Matthews PM, Moore CS. Pro-inflammatory activation of primary microglia and macrophages increases 18 kDa translocator protein expression in rodents but not humans. J Cereb Blood Flow Metab 2017; 37:2679-2690. [PMID: 28530125 PMCID: PMC5536262 DOI: 10.1177/0271678x17710182] [Citation(s) in RCA: 131] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The 18kDa Translocator Protein (TSPO) is the most commonly used tissue-specific marker of inflammation in positron emission tomography (PET) studies. It is expressed in myeloid cells such as microglia and macrophages, and in rodent myeloid cells expression increases with cellular activation. We assessed the effect of myeloid cell activation on TSPO gene expression in both primary human and rodent microglia and macrophages in vitro, and also measured TSPO radioligand binding with 3H-PBR28 in primary human macrophages. As observed previously, we found that TSPO expression increases (∼9-fold) in rodent-derived macrophages and microglia upon pro-inflammatory stimulation. However, TSPO expression does not increase with classical pro-inflammatory activation in primary human microglia (fold change 0.85 [95% CI 0.58-1.12], p = 0.47). In contrast, pro-inflammatory activation of human monocyte-derived macrophages is associated with a reduction of both TSPO gene expression (fold change 0.60 [95% CI 0.45-0.74], p = 0.02) and TSPO binding site abundance (fold change 0.61 [95% CI 0.49-0.73], p < 0.0001). These findings have important implications for understanding the biology of TSPO in activated macrophages and microglia in humans. They are also clinically relevant for the interpretation of PET studies using TSPO targeting radioligands, as they suggest changes in TSPO expression may reflect microglial and macrophage density rather than activation phenotype.
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Affiliation(s)
- David R Owen
- 1 Division of Brain Sciences, Department of Medicine Hammersmith Hospital, Imperial College London, London, UK
| | - Nehal Narayan
- 2 Nuffield Department of Orthopaedics, Rheumatology & Musculoskeletal Sciences, Botnar Research Centre, University of Oxford, Oxford, UK
| | - Lisa Wells
- 3 Imanova Centre for Imaging Science, Hammersmith Hospital, London, UK
| | - Luke Healy
- 4 Neuroimmunology Unit, Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada
| | - Erica Smyth
- 3 Imanova Centre for Imaging Science, Hammersmith Hospital, London, UK
| | - Eugenii A Rabiner
- 3 Imanova Centre for Imaging Science, Hammersmith Hospital, London, UK.,5 Centre for Neuroimaging Sciences, King's College, London, UK
| | - Dylan Galloway
- 6 Division of Biomedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John's, Newfoundland
| | - John B Williams
- 6 Division of Biomedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John's, Newfoundland
| | - Joshua Lehr
- 6 Division of Biomedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John's, Newfoundland
| | - Harpreet Mandhair
- 2 Nuffield Department of Orthopaedics, Rheumatology & Musculoskeletal Sciences, Botnar Research Centre, University of Oxford, Oxford, UK
| | - Laura An Peferoen
- 7 Pathology Department, VU Medical Centre, VU University of Amsterdam, The Netherlands
| | - Peter C Taylor
- 2 Nuffield Department of Orthopaedics, Rheumatology & Musculoskeletal Sciences, Botnar Research Centre, University of Oxford, Oxford, UK
| | - Sandra Amor
- 7 Pathology Department, VU Medical Centre, VU University of Amsterdam, The Netherlands.,8 Neuroimmunology Unit, Blizard Institute, Barts and the London School of medicine & Dentistry Queen Mary University of London, UK
| | - Jack P Antel
- 4 Neuroimmunology Unit, Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada
| | - Paul M Matthews
- 1 Division of Brain Sciences, Department of Medicine Hammersmith Hospital, Imperial College London, London, UK.,9 UK Dementia Research Institute, Imperial College London, London, UK
| | - Craig S Moore
- 6 Division of Biomedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John's, Newfoundland
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9
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Inhibition of P2X Receptors Protects Human Monocytes against Damage by Leukotoxin from Aggregatibacter actinomycetemcomitans and α-Hemolysin from Escherichia coli. Infect Immun 2016; 84:3114-3130. [PMID: 27528275 DOI: 10.1128/iai.00674-16] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Accepted: 08/05/2016] [Indexed: 01/14/2023] Open
Abstract
α-Hemolysin (HlyA) from Escherichia coli and leukotoxin A (LtxA) from Aggregatibacter actinomycetemcomitans are important virulence factors in ascending urinary tract infections and aggressive periodontitis, respectively. The extracellular signaling molecule ATP is released immediately after insertion of the toxins into plasma membranes and, via P2X receptors, is essential for the erythrocyte damage inflicted by these toxins. Moreover, ATP signaling is required for the ensuing recognition and phagocytosis of damaged erythrocytes by the monocytic cell line THP-1. Here, we investigate how these toxins affect THP-1 monocyte function. We demonstrate that both toxins trigger early ATP release and a following increase in the intracellular Ca2+ concentration ([Ca2+]i) in THP-1 monocytes. The HlyA- and LtxA-induced [Ca2+]i response is diminished by the P2 receptor antagonist in a pattern that fits the functional P2 receptor expression in these cells. Both toxins are capable of lysing THP-1 cells, with LtxA being more aggressive. Either desensitization or blockage of P2X1, P2X4, or P2X7 receptors markedly reduces toxin-induced cytolysis. This pattern is paralleled in freshly isolated human monocytes from healthy volunteers. Interestingly, only a minor fraction of the toxin-damaged THP-1 monocytes eventually lyse. P2X7 receptor inhibition generally prevents cell damage, except from a distinct cell shrinkage that prevails in response to the toxins. Moreover, we find that preexposure to HlyA preserves the capacity of THP-1 monocytes to phagocytose damaged erythrocytes and may induce readiness to discriminate between damaged and healthy erythrocytes. These findings suggest a new pharmacological target for protecting monocytes during exposure to pore-forming cytolysins during infection or injury.
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10
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Pires LR, Pêgo AP. Bridging the lesion-engineering a permissive substrate for nerve regeneration. Regen Biomater 2015; 2:203-14. [PMID: 26816642 PMCID: PMC4669012 DOI: 10.1093/rb/rbv012] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2015] [Revised: 07/21/2015] [Accepted: 06/30/2015] [Indexed: 01/30/2023] Open
Abstract
Biomaterial-based strategies to restore connectivity after lesion at the spinal cord are focused on bridging the lesion and providing an favourable substrate and a path for axonal re-growth. Following spinal cord injury (SCI) a hostile environment for neuronal cell growth is established by the activation of multiple inhibitory mechanisms that hamper regeneration to occur. Implantable scaffolds can provide mechanical support and physical guidance for axon re-growth and, at the same time, contribute to alleviate the hostile environment by the in situ delivery of therapeutic molecules and/or relevant cells. Basic research on SCI has been contributing with the description of inhibitory mechanisms for regeneration as well as identifying drugs/molecules that can target inhibition. This knowledge is the background for the development of combined strategies with biomaterials. Additionally, scaffold design is significantly evolving. From the early simple hollow conduits, scaffolds with complex architectures that can modulate cell fate are currently being tested. A number of promising pre-clinical studies combining scaffolds, cells, drugs and/or nucleic acids are reported in the open literature. Overall, it is considered that to address the multi-factorial inhibitory environment of a SCI, a multifaceted therapeutic approach is imperative. The progress in the identification of molecules that target inhibition after SCI and its combination with scaffolds and/or cells are described and discussed in this review.
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Affiliation(s)
- Liliana R. Pires
- INEB—Instituto de Engenharia Biomédica, Universidade do Porto, Rua do Campo Alegre 823, 4150-180 Porto, Portugal
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Portugal
- Faculdade de Engenharia—Universidade do Porto (FEUP), Porto, Portugal and
| | - Ana P. Pêgo
- INEB—Instituto de Engenharia Biomédica, Universidade do Porto, Rua do Campo Alegre 823, 4150-180 Porto, Portugal
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Portugal
- Faculdade de Engenharia—Universidade do Porto (FEUP), Porto, Portugal and
- Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto, Porto, Portugal
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11
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Pires LR, Rocha DN, Ambrosio L, Pêgo AP. The role of the surface on microglia function: implications for central nervous system tissue engineering. J R Soc Interface 2015; 12:rsif.2014.1224. [PMID: 25540243 DOI: 10.1098/rsif.2014.1224] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
In tissue engineering, it is well accepted that a scaffold surface has a decisive impact on cell behaviour. Here we focused on microglia-the resident immune cells of the central nervous system (CNS)-and on their response to poly(trimethylene carbonate-co-ε-caprolactone) (P(TMC-CL)) fibrous and flat surfaces obtained by electrospinning and solvent cast, respectively. This study aims to provide cues for the design of instructive surfaces that can contribute to the challenging process of CNS regeneration. Cell morphology was evidently affected by the substrate, mirroring the surface main features. Cells cultured on flat substrates presented a round shape, while cells with elongated processes were observed on the electrospun fibres. A higher concentration of the pro-inflammatory cytokine tumour necrosis factor-α was detected in culture media from microglia on fibres. Still, astrogliosis is not exacerbated when astrocytes are cultured in the presence of microglia-conditioned media obtained from cultures in contact with either substrate. Furthermore, a significant percentage of microglia was found to participate in the process of myelin phagocytosis, with the formation of multinucleated giant cells being observed only on films. Altogether, the results presented suggest that microglia in contact with the tested substrates may contribute to the regeneration process, putting forward P(TMC-CL) substrates as supporting matrices for nerve regeneration.
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Affiliation(s)
- Liliana R Pires
- INEB-Instituto de Engenharia Biomédica, Porto, Portugal Faculdade de Engenharia, Universidade do Porto, Porto, Portugal
| | - Daniela N Rocha
- INEB-Instituto de Engenharia Biomédica, Porto, Portugal Faculdade de Engenharia, Universidade do Porto, Porto, Portugal
| | - Luigi Ambrosio
- Department of Chemical Sciences and Materials Technology, National Research Council of Italy, Rome, Italy
| | - Ana Paula Pêgo
- INEB-Instituto de Engenharia Biomédica, Porto, Portugal Faculdade de Engenharia, Universidade do Porto, Porto, Portugal Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Porto, Portugal
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12
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Fung S, Cherry AE, Xu C, Stella N. Alkylindole-sensitive receptors modulate microglial cell migration and proliferation. Glia 2015; 63:1797-808. [PMID: 25914169 DOI: 10.1002/glia.22845] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2014] [Revised: 03/06/2015] [Accepted: 04/07/2015] [Indexed: 02/01/2023]
Abstract
Ligands targeting G protein-coupled receptors (GPCR) expressed by microglia have been shown to regulate distinct components of their activation process, including cell proliferation, migration and differentiation into M1 or M2 phenotypes. Cannabinoids, including the active component of the Cannabis plant, tetrahydrocannabinol (THC), and the synthetic alkylindole (AI) compound, WIN55212-2 (WIN-2), activate two molecularly identified GPCRs: CB1 and CB2 . Previous studies reported that WIN-2 activates an additional unknown GPCR that is not activated by plant-derived cannabinoids, and evidence indicates that microglia express these receptors. Detailed studies on the role of AI-sensitive receptors in microglial cell activation were difficult as no selective pharmacological tools were available. Here, three newly-developed AI analogues allowed us to determine if microglia express AI-sensitive receptors and if so, study how they regulate the microglial cell activation process. We found that mouse microglia in primary culture express functional AI-sensitive receptors as measured by radioligand binding and changes in intracellular cAMP levels, and that these receptors control both basal and ATP-stimulated migration. AI analogues inhibit cell proliferation stimulated by macrophage-colony stimulating factor (M-CSF) without affecting basal cell proliferation. Remarkably, AI analogues do not control the expression of effector proteins characteristic of M1 or M2 phenotypes; yet activating microglia with M1 and M2 cytokines reduces the microglial response to AI analogues. Our results suggest that microglia express functional AI-sensitive receptors that control select components of their activation process. Agonists of these novel targets might represent a novel class of therapeutics to influence the microglial cell activation process.
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Affiliation(s)
- Susan Fung
- Department of Pharmacology, University of Washington, 1959 NE Pacific Way, Seattle, Washington.,Graduate Program in Neurobiology and Behavior, University of Washington, 1959 NE Pacific St., Seattle, Washington
| | - Allison E Cherry
- Department of Pharmacology, University of Washington, 1959 NE Pacific Way, Seattle, Washington
| | - Cong Xu
- Department of Pharmacology, University of Washington, 1959 NE Pacific Way, Seattle, Washington
| | - Nephi Stella
- Department of Pharmacology, University of Washington, 1959 NE Pacific Way, Seattle, Washington.,Graduate Program in Neurobiology and Behavior, University of Washington, 1959 NE Pacific St., Seattle, Washington.,Department of Psychiatry and Behavioral Sciences, University of Washington, 1959 NE Pacific Way, Seattle, Washington
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13
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Moore CS, Ase AR, Kinsara A, Rao VTS, Michell-Robinson M, Leong SY, Butovsky O, Ludwin SK, Séguéla P, Bar-Or A, Antel JP. P2Y12 expression and function in alternatively activated human microglia. NEUROLOGY-NEUROIMMUNOLOGY & NEUROINFLAMMATION 2015; 2:e80. [PMID: 25821842 PMCID: PMC4370387 DOI: 10.1212/nxi.0000000000000080] [Citation(s) in RCA: 129] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/21/2014] [Accepted: 01/15/2015] [Indexed: 11/18/2022]
Abstract
Objective: To investigate and measure the functional significance of altered P2Y12 expression in the context of human microglia activation. Methods: We performed in vitro and in situ experiments to measure how P2Y12 expression can influence disease-relevant functional properties of classically activated (M1) and alternatively activated (M2) human microglia in the inflamed brain. Results: We demonstrated that compared to resting and classically activated (M1) human microglia, P2Y12 expression is increased under alternatively activated (M2) conditions. In response to ADP, the endogenous ligand of P2Y12, M2 microglia have increased ligand-mediated calcium responses, which are blocked by selective P2Y12 antagonism. P2Y12 antagonism was also shown to decrease migratory and inflammatory responses in human microglia upon exposure to nucleotides that are released during CNS injury; no effects were observed in human monocytes or macrophages. In situ experiments confirm that P2Y12 is selectively expressed on human microglia and elevated under neuropathologic conditions that promote Th2 responses, such as parasitic CNS infection. Conclusion: These findings provide insight into the roles of M2 microglia in the context of neuroinflammation and suggest a mechanism to selectively target a functionally unique population of myeloid cells in the CNS.
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Affiliation(s)
- Craig S Moore
- Division of BioMedical Sciences (C.S.M.), Neuroscience, Memorial University of Newfoundland and Labrador, St. John's, Newfoundland, Canada; Neuroimmunology Unit (C.S.M., A.A., A.K., V.T.S.R., M.M.-R., S.Y.L., P.S., A.B.-O., J.P.A.), Department of Neurology and Neurosurgery, Montreal Neurological Institute and Hospital, McGill University, Montreal, Quebec, Canada; Center for Neurologic Diseases (O.B.), Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA; and Department of Pathology and Molecular Medicine (S.K.L.), Queens University, Kingston, Ontario, Canada
| | - Ariel R Ase
- Division of BioMedical Sciences (C.S.M.), Neuroscience, Memorial University of Newfoundland and Labrador, St. John's, Newfoundland, Canada; Neuroimmunology Unit (C.S.M., A.A., A.K., V.T.S.R., M.M.-R., S.Y.L., P.S., A.B.-O., J.P.A.), Department of Neurology and Neurosurgery, Montreal Neurological Institute and Hospital, McGill University, Montreal, Quebec, Canada; Center for Neurologic Diseases (O.B.), Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA; and Department of Pathology and Molecular Medicine (S.K.L.), Queens University, Kingston, Ontario, Canada
| | - Angham Kinsara
- Division of BioMedical Sciences (C.S.M.), Neuroscience, Memorial University of Newfoundland and Labrador, St. John's, Newfoundland, Canada; Neuroimmunology Unit (C.S.M., A.A., A.K., V.T.S.R., M.M.-R., S.Y.L., P.S., A.B.-O., J.P.A.), Department of Neurology and Neurosurgery, Montreal Neurological Institute and Hospital, McGill University, Montreal, Quebec, Canada; Center for Neurologic Diseases (O.B.), Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA; and Department of Pathology and Molecular Medicine (S.K.L.), Queens University, Kingston, Ontario, Canada
| | - Vijayaraghava T S Rao
- Division of BioMedical Sciences (C.S.M.), Neuroscience, Memorial University of Newfoundland and Labrador, St. John's, Newfoundland, Canada; Neuroimmunology Unit (C.S.M., A.A., A.K., V.T.S.R., M.M.-R., S.Y.L., P.S., A.B.-O., J.P.A.), Department of Neurology and Neurosurgery, Montreal Neurological Institute and Hospital, McGill University, Montreal, Quebec, Canada; Center for Neurologic Diseases (O.B.), Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA; and Department of Pathology and Molecular Medicine (S.K.L.), Queens University, Kingston, Ontario, Canada
| | - Mackenzie Michell-Robinson
- Division of BioMedical Sciences (C.S.M.), Neuroscience, Memorial University of Newfoundland and Labrador, St. John's, Newfoundland, Canada; Neuroimmunology Unit (C.S.M., A.A., A.K., V.T.S.R., M.M.-R., S.Y.L., P.S., A.B.-O., J.P.A.), Department of Neurology and Neurosurgery, Montreal Neurological Institute and Hospital, McGill University, Montreal, Quebec, Canada; Center for Neurologic Diseases (O.B.), Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA; and Department of Pathology and Molecular Medicine (S.K.L.), Queens University, Kingston, Ontario, Canada
| | - Soo Yuen Leong
- Division of BioMedical Sciences (C.S.M.), Neuroscience, Memorial University of Newfoundland and Labrador, St. John's, Newfoundland, Canada; Neuroimmunology Unit (C.S.M., A.A., A.K., V.T.S.R., M.M.-R., S.Y.L., P.S., A.B.-O., J.P.A.), Department of Neurology and Neurosurgery, Montreal Neurological Institute and Hospital, McGill University, Montreal, Quebec, Canada; Center for Neurologic Diseases (O.B.), Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA; and Department of Pathology and Molecular Medicine (S.K.L.), Queens University, Kingston, Ontario, Canada
| | - Oleg Butovsky
- Division of BioMedical Sciences (C.S.M.), Neuroscience, Memorial University of Newfoundland and Labrador, St. John's, Newfoundland, Canada; Neuroimmunology Unit (C.S.M., A.A., A.K., V.T.S.R., M.M.-R., S.Y.L., P.S., A.B.-O., J.P.A.), Department of Neurology and Neurosurgery, Montreal Neurological Institute and Hospital, McGill University, Montreal, Quebec, Canada; Center for Neurologic Diseases (O.B.), Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA; and Department of Pathology and Molecular Medicine (S.K.L.), Queens University, Kingston, Ontario, Canada
| | - Samuel K Ludwin
- Division of BioMedical Sciences (C.S.M.), Neuroscience, Memorial University of Newfoundland and Labrador, St. John's, Newfoundland, Canada; Neuroimmunology Unit (C.S.M., A.A., A.K., V.T.S.R., M.M.-R., S.Y.L., P.S., A.B.-O., J.P.A.), Department of Neurology and Neurosurgery, Montreal Neurological Institute and Hospital, McGill University, Montreal, Quebec, Canada; Center for Neurologic Diseases (O.B.), Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA; and Department of Pathology and Molecular Medicine (S.K.L.), Queens University, Kingston, Ontario, Canada
| | - Philippe Séguéla
- Division of BioMedical Sciences (C.S.M.), Neuroscience, Memorial University of Newfoundland and Labrador, St. John's, Newfoundland, Canada; Neuroimmunology Unit (C.S.M., A.A., A.K., V.T.S.R., M.M.-R., S.Y.L., P.S., A.B.-O., J.P.A.), Department of Neurology and Neurosurgery, Montreal Neurological Institute and Hospital, McGill University, Montreal, Quebec, Canada; Center for Neurologic Diseases (O.B.), Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA; and Department of Pathology and Molecular Medicine (S.K.L.), Queens University, Kingston, Ontario, Canada
| | - Amit Bar-Or
- Division of BioMedical Sciences (C.S.M.), Neuroscience, Memorial University of Newfoundland and Labrador, St. John's, Newfoundland, Canada; Neuroimmunology Unit (C.S.M., A.A., A.K., V.T.S.R., M.M.-R., S.Y.L., P.S., A.B.-O., J.P.A.), Department of Neurology and Neurosurgery, Montreal Neurological Institute and Hospital, McGill University, Montreal, Quebec, Canada; Center for Neurologic Diseases (O.B.), Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA; and Department of Pathology and Molecular Medicine (S.K.L.), Queens University, Kingston, Ontario, Canada
| | - Jack P Antel
- Division of BioMedical Sciences (C.S.M.), Neuroscience, Memorial University of Newfoundland and Labrador, St. John's, Newfoundland, Canada; Neuroimmunology Unit (C.S.M., A.A., A.K., V.T.S.R., M.M.-R., S.Y.L., P.S., A.B.-O., J.P.A.), Department of Neurology and Neurosurgery, Montreal Neurological Institute and Hospital, McGill University, Montreal, Quebec, Canada; Center for Neurologic Diseases (O.B.), Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA; and Department of Pathology and Molecular Medicine (S.K.L.), Queens University, Kingston, Ontario, Canada
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Migration and Phagocytic Ability of Activated Microglia During Post-natal Development is Mediated by Calcium-Dependent Purinergic Signalling. Mol Neurobiol 2015; 53:944-954. [PMID: 25575683 DOI: 10.1007/s12035-014-9064-3] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Accepted: 12/09/2014] [Indexed: 01/10/2023]
Abstract
Microglia play an important role in synaptic pruning and controlled phagocytosis of neuronal cells during developmental stages. However, the mechanisms that regulate these functions are not completely understood. The present study was designed to investigate the role of purinergic signalling in microglial migration and phagocytic activity during post-natal brain development. One-day-old BALB/c mice received lipopolysaccharide (LPS) and/or a purinergic analogue (2-methylthioladenosine-5'-diphosphate; 2MeSADP), intracerebroventrically (i.c.v.). Combined administration of LPS and 2MeSADP resulted in activation of microglia as evident from increased expression of ionised calcium-binding adapter molecule 1 (Iba1). Activated microglia showed increased expression of purinergic receptors (P2Y2, P2Y6 and P2Y12). LPS either alone or in combination with 2MeSADP induced the expression of Na(+)/Ca(2+) exchanger (NCX-1) and P/Q-type Ca(2+) channels along with MARCKS-related protein (MRP), which is an integral component of cell migration machinery. In addition, LPS and 2MeSADP administration induced the expression of microglial CD11b and DAP12 (DNAX-activation protein 12), which are known to be involved in phagocytosis of neurons during development. Interestingly, administration of thapsigargin (TG), a specific Ca(2+)-ATPase inhibitor of endoplasmic reticulum, prevented the LPS/2MeSADP-induced microglial activation and migration by down-regulating the expression of Iba1 and MRP, respectively. Moreover, TG also reduced the LPS/2MeSADP-induced expression of CD11b/DAP12. Taken together, the findings reveal for the first time that Ca(2+)-mediated purinergic receptors regulate the migration and phagocytic ability of microglia during post-natal brain development.
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15
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Watkins LR, Hutchinson MR. A concern on comparing ‘apples’ and ‘oranges’ when differences between microglia used in human and rodent studies go far, far beyond simply species: comment on Smith and Dragunow. Trends Neurosci 2014; 37:189-90. [DOI: 10.1016/j.tins.2014.02.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2014] [Accepted: 02/06/2014] [Indexed: 10/25/2022]
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16
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Smith AM, Dragunow M. The human side of microglia. Trends Neurosci 2014; 37:125-35. [DOI: 10.1016/j.tins.2013.12.001] [Citation(s) in RCA: 131] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2013] [Revised: 12/04/2013] [Accepted: 12/05/2013] [Indexed: 12/13/2022]
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17
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Shieh CH, Heinrich A, Serchov T, van Calker D, Biber K. P2X7-dependent, but differentially regulated release of IL-6, CCL2, and TNF-α in cultured mouse microglia. Glia 2014; 62:592-607. [PMID: 24470356 DOI: 10.1002/glia.22628] [Citation(s) in RCA: 153] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2013] [Revised: 12/20/2013] [Accepted: 12/23/2013] [Indexed: 01/04/2023]
Abstract
ATP is an important regulator of microglia and its effects on microglial cytokine release are currently discussed as important contributors in a variety of brain diseases. We here analyzed the effects of ATP on the production of six inflammatory mediators (IL-6, IL-10, CCL2, IFN-γ, TNF-α, and IL-12p70) in cultured mouse primary microglia. Stimulation of P2X7 receptor by ATP (1 mM) or BzATP (500 µM) evoked the mRNA expression and release of proinflammatory cytokines IL-6, TNF-α, and the chemokine CCL2 in WT cells but not in P2X7(-/-) cells. The effects of ATP and BzATP were inhibited by the nonselective P2 receptor antagonists PPADs and suramin. Various selective P2X7 receptor antagonists blocked the P2X7-dependent release of IL-6 and CCL2, but, surprisingly, had no effect on BzATP-induced release of TNF-α in microglia. Calcium measurements confirmed that P2X7 is the main purine receptor activated by BzATP in microglia and showed that all P2X7 antagonists were functional. It is also presented that pannexin-1 hemichannel function and potential P2X4/P2X7 heterodimers are not involved in P2X7-dependent release of IL-6, CCL2, and TNF-α in microglia. How P2X7-specific antagonists only affect P2X7-dependent IL-6 and CCL2 release, but not TNF-α release is at the moment unclear, but indicates that the P2X7-dependent release of cytokines in microglia is differentially regulated.
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Affiliation(s)
- Chu-Hsin Shieh
- Department of Psychiatry and Psychotherapy, University Hospital of Freiburg, Freiburg, Germany; Faculty of Biology, University of Freiburg, Freiburg, Germany
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18
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Moore CS, Rao VTS, Durafourt BA, Bedell BJ, Ludwin SK, Bar-Or A, Antel JP. miR-155 as a multiple sclerosis-relevant regulator of myeloid cell polarization. Ann Neurol 2013; 74:709-20. [PMID: 23818336 DOI: 10.1002/ana.23967] [Citation(s) in RCA: 171] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2013] [Revised: 06/08/2013] [Accepted: 06/19/2013] [Indexed: 12/19/2022]
Abstract
OBJECTIVE To define the functional significance of increased miR-155 expression in myeloid cells in multiple sclerosis (MS). METHODS miR-155 expression levels were measured in CD14+ monocytes from untreated relapsing-remitting MS patients and compared to healthy controls. Similar microRNA (miRNA) analyses were performed in laser-captured CD68+ cells from perivascular (blood-derived macrophages) and parenchymal (microglia) brain regions in both active MS lesions and noninflammatory cases. Using human adult blood-derived macrophages and brain-derived microglia, in vitro experiments were performed to demonstrate how miR-155 influences the polarization state, phenotype, and functional properties of myeloid cells, in addition to their ability to subsequently impact adaptive T-cell responses. RESULTS In MS, miR-155 expression was significantly increased in both peripheral circulating CD14+ monocytes and active lesions (CD68+ cells) compared to control donor monocytes and parenchymal microglia, respectively. In vitro, miR-155 was significantly increased in both M1-polarized primary human macrophages and microglia. Transfection of an miR-155 mimic increased proinflammatory cytokine secretion and costimulatory surface marker expression in both cell types; an miR-155 inhibitor decreased proinflammatory cytokine expression. Coculture experiments demonstrated that allogeneic T-cell responses were significantly enhanced in the presence of miR-155-transfected myeloid cells compared to controls. INTERPRETATION Our results demonstrate that miR-155 regulates proinflammatory responses in both blood-derived and central nervous system (CNS)-resident myeloid cells, in addition to impacting subsequent adaptive immune responses. Differential miRNA expression may therefore provide insight into mechanisms responsible for distinct phenotypic and functional properties of myeloid cells, thus impacting their ability to influence CNS injury and repair.
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Affiliation(s)
- Craig S Moore
- Neuroimmunology Unit, Department of Neurology and Neurosurgery, Montreal Neurological Institute and Hospital, McGill University, Montreal, Quebec
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19
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The controversial role of microglia in malignant gliomas. Clin Dev Immunol 2013; 2013:285246. [PMID: 23983766 PMCID: PMC3741958 DOI: 10.1155/2013/285246] [Citation(s) in RCA: 146] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2013] [Accepted: 06/19/2013] [Indexed: 01/01/2023]
Abstract
Malignant gliomas contain stroma and a variety of immune cells including abundant activated microglia/macrophages. Mounting evidence indicates that the glioma microenvironment converts the glioma-associated microglia/macrophages (GAMs) into glioma-supportive, immunosuppressive cells; however, GAMs can retain intrinsic anti-tumor properties. Here, we review and discuss this duality and the potential therapeutic strategies that may inhibit their glioma-supportive and propagating functions.
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Smith AM, Gibbons HM, Oldfield RL, Bergin PM, Mee EW, Curtis MA, Faull RLM, Dragunow M. M-CSF increases proliferation and phagocytosis while modulating receptor and transcription factor expression in adult human microglia. J Neuroinflammation 2013; 10:85. [PMID: 23866312 PMCID: PMC3729740 DOI: 10.1186/1742-2094-10-85] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2013] [Accepted: 07/09/2013] [Indexed: 11/18/2022] Open
Abstract
Background Microglia are the primary immune cells of the brain whose phenotype largely depends on their surrounding micro-environment. Microglia respond to a multitude of soluble molecules produced by a variety of brain cells. Macrophage colony-stimulating factor (M-CSF) is a cytokine found in the brain whose receptor is expressed by microglia. Previous studies suggest a critical role for M-CSF in brain development and normal functioning as well as in several disease processes involving neuroinflammation. Methods Using biopsy tissue from patients with intractable temporal epilepsy and autopsy tissue, we cultured primary adult human microglia to investigate their response to M-CSF. Mixed glial cultures were treated with 25 ng/ml M-CSF for 96 hours. Proliferation and phagocytosis assays, and high through-put immunocytochemistry, microscopy and image analysis were performed to investigate microglial phenotype and function. Results We found that the phenotype of primary adult human microglia was markedly changed following exposure to M-CSF. A greater number of microglia were present in the M-CSF- treated cultures as the percentage of proliferating (BrdU and Ki67-positive) microglia was greatly increased. A number of changes in protein expression occurred following M-CSF treatment, including increased transcription factors PU.1 and C/EBPβ, increased DAP12 adaptor protein, increased M-CSF receptor (CSF-1R) and IGF-1 receptor, and reduced HLA-DP, DQ, DR antigen presentation protein. Furthermore, a distinct morphological change was observed with elongation of microglial processes. These changes in phenotype were accompanied by a functional increase in phagocytosis of Aβ1-42 peptide. Conclusions We show here that the cytokine M-CSF dramatically influences the phenotype of adult human microglia. These results pave the way for future investigation of M-CSF-related targets for human therapeutic benefit.
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Affiliation(s)
- Amy M Smith
- Department of Pharmacology and Clinical Pharmacology, The University of Auckland, Private Bag 92019, Auckland 1142, New Zealand
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21
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Corriden R, Insel PA. New insights regarding the regulation of chemotaxis by nucleotides, adenosine, and their receptors. Purinergic Signal 2012; 8:587-98. [PMID: 22528684 PMCID: PMC3360098 DOI: 10.1007/s11302-012-9311-x] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2011] [Accepted: 01/05/2012] [Indexed: 12/23/2022] Open
Abstract
The directional movement of cells can be regulated by ATP, certain other nucleotides (e.g., ADP, UTP), and adenosine. Such regulation occurs for cells that are "professional phagocytes" (e.g., neutrophils, macrophages, certain lymphocytes, and microglia) and that undergo directional migration and subsequent phagocytosis. Numerous other cell types (e.g., fibroblasts, endothelial cells, neurons, and keratinocytes) also change motility and migration in response to ATP, other nucleotides, and adenosine. In this article, we review how nucleotides and adenosine modulate chemotaxis and motility and highlight the importance of nucleotide- and adenosine-regulated cell migration in several cell types: neutrophils, microglia, endothelial cells, and cancer cells. We also discuss difficulties in conducting experiments and drawing conclusions regarding the ability of nucleotides and adenosine to modulate the migration of professional and non-professional phagocytes.
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Affiliation(s)
- Ross Corriden
- Institute of Cell Signalling, University of Nottingham, Nottingham, UK
| | - Paul A. Insel
- Departments of Pharmacology and Medicine, University of California, San Diego, CA USA
- Department of Pharmacology, University of California San Diego, 9500 Gilman Drive, Mail code 0636, La Jolla, CA 92093 USA
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Hidetoshi TS, Makoto T, Inoue K. P2Y receptors in microglia and neuroinflammation. ACTA ACUST UNITED AC 2012. [DOI: 10.1002/wmts.46] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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Immune system in the brain: a modulatory role on dendritic spine morphophysiology? Neural Plast 2012; 2012:348642. [PMID: 22548192 PMCID: PMC3324176 DOI: 10.1155/2012/348642] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2011] [Revised: 01/10/2012] [Accepted: 01/26/2012] [Indexed: 12/14/2022] Open
Abstract
The central nervous system is closely linked to the immune system at several levels. The brain parenchyma is separated from the periphery by the blood brain barrier, which under normal conditions prevents the entry of mediators such as activated leukocytes, antibodies, complement factors, and cytokines. The myeloid cell lineage plays a crucial role in the development of immune responses at the central level, and it comprises two main subtypes: (1) resident microglia, distributed throughout the brain parenchyma; (2) perivascular macrophages located in the brain capillaries of the basal lamina and the choroid plexus. In addition, astrocytes, oligodendrocytes, endothelial cells, and, to a lesser extent, neurons are implicated in the immune response in the central nervous system. By modulating synaptogenesis, microglia are most specifically involved in restoring neuronal connectivity following injury. These cells release immune mediators, such as cytokines, that modulate synaptic transmission and that alter the morphology of dendritic spines during the inflammatory process following injury. Thus, the expression and release of immune mediators in the brain parenchyma are closely linked to plastic morphophysiological changes in neuronal dendritic spines. Based on these observations, it has been proposed that these immune mediators are also implicated in learning and memory processes.
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Garcia-Oscos F, Salgado H, Hall S, Thomas F, Farmer GE, Bermeo J, Galindo LC, Ramirez RD, D’Mello S, Rose-John S, Atzori M. The stress-induced cytokine interleukin-6 decreases the inhibition/excitation ratio in the rat temporal cortex via trans-signaling. Biol Psychiatry 2012; 71:574-82. [PMID: 22196984 PMCID: PMC4732871 DOI: 10.1016/j.biopsych.2011.11.018] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2011] [Revised: 10/26/2011] [Accepted: 11/11/2011] [Indexed: 10/14/2022]
Abstract
BACKGROUND Although it is known that stress elevates the levels of pro-inflammatory cytokines and promotes hyper-excitable central conditions, a causal relationship between these two factors has not yet been identified. Recent studies suggest that increases in interleukin 6 (IL-6) levels are specifically associated with stress. We hypothesized that IL-6 acutely and directly induces cortical hyper-excitability by altering the balance between synaptic excitation and inhibition. METHODS We used patch-clamp to determine the effects of exogenous or endogenous IL-6 on electrically evoked postsynaptic currents on a cortical rat slice preparation. We used control subjects or animals systemically injected with lipopolysaccharide or subjected to electrical foot-shock as rat models of stress. RESULTS In control animals, IL-6 did not affect excitatory postsynaptic currents but selectively and reversibly reduced the amplitude of inhibitory postsynaptic currents with a postsynaptic effect. The IL-6-induced inhibitory postsynaptic currents decrease was inhibited by drugs interfering with receptor trafficking and/or internalization, including wortmannin, Brefeldin A, 2-Br-hexadecanoic acid, or dynamin peptide inhibitor. In both animal models, stress-induced decrease in synaptic inhibition/excitation ratio was prevented by prior intra-ventricular injection of an analog of the endogenous IL-6 trans-signaling blocker gp130. CONCLUSIONS Our results suggest that stress-induced IL-6 shifts the balance between synaptic inhibition and excitation in favor of the latter, possibly by decreasing the density of functional γ-aminobutyric acid A receptors, accelerating their removal and/or decreasing their insertion rate from/to the plasma membrane. We speculate that this mechanism could contribute to stress-induced detrimental long-term increases in central excitability present in a variety of neurological and psychiatric conditions.
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Durafourt BA, Moore CS, Zammit DA, Johnson TA, Zaguia F, Guiot MC, Bar-Or A, Antel JP. Comparison of polarization properties of human adult microglia and blood-derived macrophages. Glia 2012; 60:717-27. [DOI: 10.1002/glia.22298] [Citation(s) in RCA: 331] [Impact Index Per Article: 27.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2011] [Revised: 12/21/2011] [Accepted: 01/06/2012] [Indexed: 11/05/2022]
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Commentary on Landry et al.: "Propentofylline, a CNS glial modulator, does not decrease pain in post-herpetic neuralgia patients: in vitro evidence for differential responses in human and rodent microglia and macrophages". Exp Neurol 2012; 234:351-3. [PMID: 22269389 DOI: 10.1016/j.expneurol.2012.01.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2011] [Revised: 12/21/2011] [Accepted: 01/05/2012] [Indexed: 11/20/2022]
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Landry RP, Jacobs VL, Romero-Sandoval EA, DeLeo JA. Propentofylline, a CNS glial modulator does not decrease pain in post-herpetic neuralgia patients: in vitro evidence for differential responses in human and rodent microglia and macrophages. Exp Neurol 2011; 234:340-50. [PMID: 22119425 DOI: 10.1016/j.expneurol.2011.11.006] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2011] [Revised: 10/20/2011] [Accepted: 11/07/2011] [Indexed: 12/13/2022]
Abstract
There is a growing body of preclinical evidence for the potential involvement of glial cells in neuropathic pain conditions. Several glial-targeted agents are in development for the treatment of pain conditions. Here we report the failure of a glial modulating agent, propentofylline, to decrease pain reported in association with post-herpetic neuralgia. We offer new evidence to help explain why propentofylline failed in patients by describing in vitro functional differences between rodent and human microglia and macrophages. We directly compared the proinflammatory response induced by lipopolysaccharide (LPS) with or without propentofylline using rat postnatal microglia, rat peritoneal macrophages, human fetal microglia, human peripheral macrophages and human immortalized THP-1 cells. We measured tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β) and nitrite release (as an indicator of nitric oxide (NO)) as downstream indicators. We found that LPS treatment did not induce nitrite in human microglia, macrophages or THP-1 cells; however LPS treatment did induce nitrite release in rat microglia and macrophages. Following LPS exposure, propentofylline blocked TNF-α release in rodent microglia with all the doses tested (1-100 μM), and dose-dependently decreased TNF-α release in rodent macrophages. Propentofylline partially decreased TNF-α (35%) at 100 μM in human microglia, macrophages and THP-1 macrophages. Propentofylline blocked nitrite release from LPS stimulated rat microglia and inhibited nitrite in LPS-stimulated rat macrophages. IL-1β was decreased in LPS-stimulated human microglia following propentofylline at 100 μM. Overall, human microglia were less responsive to LPS stimulation and propentofylline treatment than the other cell types. Our data demonstrate significant functional differences between cell types and species following propentofylline treatment and LPS stimulation. These results may help explain the differential behavioral effects of propentofylline observed between rodent models of pain and the human clinical trial.
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Affiliation(s)
- Russell P Landry
- Department of Pharmacology and Toxicology, Dartmouth Medical School, Hanover, NH 03755, USA
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Jacobs VL, Landry RP, Liu Y, Romero-Sandoval EA, De Leo JA. Propentofylline decreases tumor growth in a rodent model of glioblastoma multiforme by a direct mechanism on microglia. Neuro Oncol 2011; 14:119-31. [PMID: 22086978 DOI: 10.1093/neuonc/nor194] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Glioblastoma multiforme (GBM) is the most common and aggressive primary brain cancer, with a median survival of less than 2 years after diagnosis. The tumor microenvironment plays a critical role in tumor invasion and progression. Microglia and infiltrating macrophages are the most abundant immune cells in the tumor. In the present study, we demonstrate that systemic propentofylline (PPF), an atypical methylxanthine with central nervous system (CNS) glial modulating and anti-inflammatory actions, significantly decreased tumor growth in a CNS-1 rat model of GBM by targeting microglia and not tumor cells. Rats received tumor injections of 1 × 10(5) CNS-1 cells in the right striatum with daily intraperitonial injections of PPF (50 mg/kg) or saline beginning the day of tumor injection. PPF did not cause apoptosis or decrease proliferation of CNS-1 tumor cells. Furthermore, we demonstrate, using in vitro methods, that PPF decreased microglial migration toward CNS-1 tumor cells and decreased MMP-9 expression. The effects of PPF were shown to be specific to microglia and not peripheral macrophages. These results support a differential functional role of resident microglia and infiltrating macrophages in the brain tumor environment. Our data highlight microglia as a crucial target for future therapeutic development and present PPF as a possible drug for treatment of human GBM.
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Affiliation(s)
- Valerie L Jacobs
- Department of Pharmacology, Dartmouth Medical School, Hanover, NH 03755, USA
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Sargsyan SA, Blackburn DJ, Barber SC, Grosskreutz J, De Vos KJ, Monk PN, Shaw PJ. A comparison of in vitro properties of resting SOD1 transgenic microglia reveals evidence of reduced neuroprotective function. BMC Neurosci 2011; 12:91. [PMID: 21943126 PMCID: PMC3191510 DOI: 10.1186/1471-2202-12-91] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2011] [Accepted: 09/23/2011] [Indexed: 12/11/2022] Open
Abstract
Background Overexpression of mutant copper/zinc superoxide dismutase (SOD1) in rodents has provided useful models for studying the pathogenesis of amyotrophic lateral sclerosis (ALS). Microglia have been shown to contribute to ALS disease progression in these models, although the mechanism of this contribution remains to be elucidated. Here, we present the first evidence of the effects of overexpression of mutant (TG G93A) and wild type (TG WT) human SOD1 transgenes on a set of functional properties of microglia relevant to ALS progression, including expression of integrin β-1, spreading and migration, phagocytosis of apoptotic neuronal cell debris, and intracellular calcium changes in response to an inflammatory stimulus. Results TG SOD1 G93A but not TG SOD1 WT microglia had lower expression levels of the cell adhesion molecule subunit integrin β-1 than their NTG control cells [NTG (G93A) and NTG (WT), respectively, 92.8 ± 2.8% on TG G93A, 92.0 ± 6.6% on TG WT, 100.0 ± 1.6% on NTG (G93A), and 100.0 ± 2.7% on NTG (WT) cells], resulting in decreased spreading ability, with no effect on ability to migrate. Both TG G93A and TG WT microglia had reduced capacity to phagocytose apoptotic neuronal cell debris (13.0 ± 1.3% for TG G93A, 16.5 ± 1.9% for TG WT, 28.6 ± 1.8% for NTG (G93A), and 26.9 ± 2.8% for NTG (WT) cells). Extracellular stimulation of microglia with ATP resulted in smaller increase in intracellular free calcium in TG G93A and TG WT microglia relative to NTG controls (0.28 ± 0.02 μM for TG G93A, 0.24 ± 0.03 μM for TG WT, 0.39 ± 0.03 μM for NTG (G93A), and 0.37 ± 0.05 μM for NTG (WT) microglia). Conclusions These findings indicate that, under resting conditions, microglia from mutant SOD1 transgenic mice have a reduced capacity to elicit physiological responses following tissue disturbances and that higher levels of stimulatory signals, and/or prolonged stimulation may be necessary to initiate these responses. Overall, resting mutant SOD1-overexpressing microglia may have reduced capacity to function as sensors of disturbed tissue/cellular homeostasis in the CNS and thus have reduced neuroprotective function.
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Affiliation(s)
- Siranush A Sargsyan
- Department of Medicine, University of Colorado Denver School of Medicine, CO, USA.
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Cudaback E, Li X, Montine KS, Montine TJ, Keene CD. Apolipoprotein E isoform-dependent microglia migration. FASEB J 2011; 25:2082-91. [PMID: 21385991 DOI: 10.1096/fj.10-176891] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Complement component C5a and ATP are potent effectors of microglial movement and are increased in diverse neurodegenerative diseases and at sites of injury. Apolipoprotein E (apoE) influences microglial function, and different human apoE isoforms confer variable risk for development of neurodegenerative disorders, especially Alzheimer's disease. The purpose of this investigation was to test the hypothesis that mouse apoE and human apoE isoforms influence microglial migration. Using primary wild-type and apoE-deficient microglia, we show that C5a- and ATP-stimulated chemotaxis are largely apoE-dependent processes with different molecular bases. Although the C5a-dependent chemotaxis of wild-type microglia was completely blocked by receptor-associated protein (RAP), suggesting apoE receptor involvement, ATP-stimulated migration was unaffected by RAP but was associated with differential ERK phosphorylation. Studies using primary microglia derived from targeted replacement mice "humanized" for the coding exons (protein isoform) of human ε2 (apoE2), ε3 (apoE3), or ε4 (apoE4) allele of APOE revealed that primary mouse microglia expressing apoE4 or apoE2 exhibited significantly reduced C5a- and ATP-stimulated migration compared with microglia expressing human apoE3. This study, for the first time, demonstrates apoE dependence and apoE isoform-specific modulation of microglial migration in response to distinct chemotactic stimuli commonly associated with neurodegenerative disease.
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Affiliation(s)
- Eiron Cudaback
- Department of Pathology, Neuropathology Division, University of Washington, Seattle, Washington, USA
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Abstract
The immune and inflammatory responses initiated by the interaction of a pathogen with airway surfaces constitute vital mechanisms to eradicate an infection. Sentinel dendritic cells embedded in the mucosa migrate to the lymph nodes to induce immune responses, whereas epithelial cells release chemokines to recruit inflammatory cells engaged in the active destruction of the intruder. All immune and inflammatory cells are regulated by customized purinergic networks of receptors and ectonucleotidases. The general concept is that bacterial products induce ATP release, which activates P2 receptors to initiate an inflammatory response, and is terminated by the conversion of ATP into adenosine (ADO) to initiate P1 receptor-mediated negative feedback responses. However, this chapter exposes a far more complex purinergic regulation of critical functions, such as the differentiation of naive lymphocytes and the complex maturation and secretion of pro-cytokines (i.e. IL-1β) by the "inflammasome". This material also reconciles decades of research by exposing the specificity and plasticity of the signaling network expressed by each immune and inflammatory cell, which changes through cell differentiation and in response to infectious or inflammatory mediators. By the end of this chapter, the reader will have a new appreciation for this aspect of airway defenses, and several leads in terms of therapeutic applications for the treatment of chronic respiratory diseases.
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Tatar CL, Appikatla S, Bessert DA, Paintlia AS, Singh I, Skoff RP. Increased Plp1 gene expression leads to massive microglial cell activation and inflammation throughout the brain. ASN Neuro 2010; 2:e00043. [PMID: 20885931 PMCID: PMC2946597 DOI: 10.1042/an20100016] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2010] [Revised: 08/11/2010] [Accepted: 08/19/2010] [Indexed: 02/06/2023] Open
Abstract
PMD (Pelizaeus-Merzbacher disease) is a rare neurodegenerative disorder that impairs motor and cognitive functions and is associated with a shortened lifespan. The cause of PMD is mutations of the PLP1 [proteolipid protein 1 gene (human)] gene. Transgenic mice with increased Plp1 [proteolipid protein 1 gene (non-human)] copy number model most aspects of PMD patients with duplications. Hypomyelination and demyelination are believed to cause the neurological abnormalities in mammals with PLP1 duplications. We show, for the first time, intense microglial reactivity throughout the grey and white matter of a transgenic mouse line with increased copy number of the native Plp1 gene. Activated microglia in the white and grey matter of transgenic mice are found as early as postnatal day 7, before myelin commences in normal cerebra. This finding indicates that degeneration of myelin does not cause the microglial response. Microglial numbers are doubled due to in situ proliferation. Compared with the jp (jimpy) mouse, which has much more oligodendrocyte death and hardly any myelin, microglia in the overexpressors show a more dramatic microglial reactivity than jp, especially in the grey matter. Predictably, many classical markers of an inflammatory response, including TNF-α (tumour necrosis factor-α) and IL-6, are significantly up-regulated manyfold. Because inflammation is believed to contribute to axonal degeneration in multiple sclerosis and other neurodegenerative diseases, inflammation in mammals with increased Plp1 gene dosage may also contribute to axonal degeneration described in patients and rodents with PLP1 increased gene dosage.
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Key Words
- BrdU, bromodeoxyuridine
- CCL3, CC chemokine ligand 3
- CCR1, CC chemokine receptor 1
- CD11b, cluster of differentiation molecule 11B
- CD8, cluster of differentiation 8
- CNS, central nervous system
- CRP, C-reactive protein
- CXCL, CXC chemokine ligand
- DAB, diaminobenzidine
- DPN, day postnatal
- EAE, experimental allergic encephalomyelitis
- GAPDH, glyceraldehyde-3-phosphate dehydrogenase
- HRP, horseradish peroxidase
- IL-1β, interleukin-1β
- Iba1, ionized calcium-binding adaptor molecule 1
- MOG, myelin oligodendrocyte glycoprotein
- PLP1, proteolipid protein 1 gene (human)
- PMD, Pelizaeus–Merzbacher disease
- Pelizaeus–Merzbacher disease
- Plp1, proteolipid protein 1 gene (non-human)
- QPCR, quantitative PCR
- TNF-α, tumour necrosis factor-α
- Ta, Tabby
- iNOS, inducible nitric oxide synthase
- inflammation
- jp, jimpy
- microglia
- myelin
- oligodendrocyte
- proteolipid protein
- qRT–PCR, quantitative reverse transcription–PCR
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Affiliation(s)
- Carrie L Tatar
- *Department of Anatomy and Cell Biology, Wayne State University, Detroit, MI 48201, U.S.A
| | - Sunita Appikatla
- *Department of Anatomy and Cell Biology, Wayne State University, Detroit, MI 48201, U.S.A
| | - Denise A Bessert
- *Department of Anatomy and Cell Biology, Wayne State University, Detroit, MI 48201, U.S.A
| | - Ajaib S Paintlia
- †Department of Pediatrics, Medical University of South Carolina, Charleston, SC 29425, U.S.A
| | - Inderjit Singh
- †Department of Pediatrics, Medical University of South Carolina, Charleston, SC 29425, U.S.A
| | - Robert P Skoff
- *Department of Anatomy and Cell Biology, Wayne State University, Detroit, MI 48201, U.S.A
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Gupta S, Knight AG, Gupta S, Knapp PE, Hauser KF, Keller JN, Bruce-Keller AJ. HIV-Tat elicits microglial glutamate release: role of NAPDH oxidase and the cystine-glutamate antiporter. Neurosci Lett 2010; 485:233-6. [PMID: 20849923 DOI: 10.1016/j.neulet.2010.09.019] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2010] [Revised: 08/16/2010] [Accepted: 09/03/2010] [Indexed: 10/19/2022]
Abstract
Excitotoxicity and/or microglial reactivity might underlie neurologic dysfunction in HIV patients. The HIV regulatory protein Tat is both neurotoxic and pro-inflammatory, suggesting that Tat might participate in the pathogenesis of HIV-associated neurocognitive disorders (HAND). The present study was undertaken to evaluate if Tat can increase extracellular glutamate, and was specifically designed to determine the degree to which, and the mechanisms by which Tat could drive microglial glutamate release. Data show that application of Tat to cultured primary microglia caused dose-dependent increases in extracellular glutamate that were exacerbated by morphine, which is known to worsen Tat cytotoxicity. Tat-induced glutamate release was decreased by inhibitors of p38 and p42/44 MAPK, and by inhibitors of NADPH oxidase and the x(c)(-) cystine-glutamate antiporter. Furthermore, Tat increased expression of the catalytic subunit of x(c)(-) (xCT), but Tat-induced increases in xCT mRNA were not affected by inhibition of NADPH oxidase or x(c)(-) activity. Together, these data describe a specific and biologically significant signaling component of the microglial response to Tat, and suggest that excitotoxic neuropathology associated with HIV infection might originate in part with Tat-induced activation of microglial glutamate release.
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Affiliation(s)
- Sunita Gupta
- Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, LA 70808, USA
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