1
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Alzghool OM, Aarnio R, Helin JS, Wahlroos S, Keller T, Matilainen M, Solis J, Danon JJ, Kassiou M, Snellman A, Solin O, Rinne JO, Haaparanta-Solin M. Glial reactivity in a mouse model of beta-amyloid deposition assessed by PET imaging of P2X7 receptor and TSPO using [ 11C]SMW139 and [ 18F]F-DPA. EJNMMI Res 2024; 14:25. [PMID: 38446249 PMCID: PMC10917722 DOI: 10.1186/s13550-024-01085-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Accepted: 02/22/2024] [Indexed: 03/07/2024] Open
Abstract
BACKGROUND P2X7 receptor has emerged as a potentially superior PET imaging marker to TSPO, the gold standard for imaging glial reactivity. [11C]SMW139 is the most recently developed radiotracer to image P2X7 receptor. The aim of this study was to image reactive glia in the APP/PS1-21 transgenic (TG) mouse model of Aβ deposition longitudinally using [11C]SMW139 targeting P2X7 receptor and to compare tracer uptake to that of [18F]F-DPA targeting TSPO at the final imaging time point. TG and wild type (WT) mice underwent longitudinal in vivo PET imaging using [11C]SMW139 at 5, 8, 11, and 14 months, followed by [18F]F-DPA PET scan only at 14 months. In vivo imaging results were verified by ex vivo brain autoradiography, immunohistochemical staining, and analysis of [11C]SMW139 unmetabolized fraction in TG and WT mice. RESULTS Longitudinal change in [11C]SMW139 standardized uptake values (SUVs) showed no statistically significant increase in the neocortex and hippocampus of TG or WT mice, which was consistent with findings from ex vivo brain autoradiography. Significantly higher [18F]F-DPA SUVs were observed in brain regions of TG compared to WT mice. Quantified P2X7-positive staining in the cortex and thalamus of TG mice showed a minor increase in receptor expression with ageing, while TSPO-positive staining in the same regions showed a more robust increase in expression in TG mice as they aged. [11C]SMW139 was rapidly metabolized in mice, with 33% of unmetabolized fraction in plasma and 29% in brain homogenates 30 min after injection. CONCLUSIONS [11C]SMW139, which has a lower affinity for the rodent P2X7 receptor than the human version of the receptor, was unable to image the low expression of P2X7 receptor in the APP/PS1-21 mouse model. Additionally, the rapid metabolism of [11C]SMW139 in mice and the presence of several brain-penetrating radiometabolites significantly impacted the analysis of in vivo PET signal of the tracer. Finally, [18F]F-DPA targeting TSPO was more suitable for imaging reactive glia and neuroinflammatory processes in the APP/PS1-21 mouse model, based on the findings presented in this study and previous studies with this mouse model.
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Affiliation(s)
- Obada M Alzghool
- PET Preclinical Imaging Laboratory, Turku PET Centre, University of Turku, Tykistökatu 6 A, 20520, Turku, Finland.
- Medicity Research Laboratory, University of Turku, Tykistökatu 6 A, 20520, Turku, Finland.
- Drug Research Doctoral Programme, University of Turku, Turku, Finland.
- Turku University Hospital, Turku PET Centre, Kiinamyllynkatu 4-8, 20520, Turku, Finland.
| | - Richard Aarnio
- PET Preclinical Imaging Laboratory, Turku PET Centre, University of Turku, Tykistökatu 6 A, 20520, Turku, Finland
- Medicity Research Laboratory, University of Turku, Tykistökatu 6 A, 20520, Turku, Finland
- Drug Research Doctoral Programme, University of Turku, Turku, Finland
| | - Jatta S Helin
- PET Preclinical Imaging Laboratory, Turku PET Centre, University of Turku, Tykistökatu 6 A, 20520, Turku, Finland
- Medicity Research Laboratory, University of Turku, Tykistökatu 6 A, 20520, Turku, Finland
| | - Saara Wahlroos
- Radiopharmaceutical Chemistry Laboratory, Turku PET Centre, University of Turku, Kiinamyllynkatu 4-8, 20520, Turku, Finland
| | - Thomas Keller
- Radiopharmaceutical Chemistry Laboratory, Turku PET Centre, University of Turku, Kiinamyllynkatu 4-8, 20520, Turku, Finland
| | - Markus Matilainen
- Turku University Hospital, Turku PET Centre, Kiinamyllynkatu 4-8, 20520, Turku, Finland
| | - Junel Solis
- Turku BioImaging, Åbo Akademi University and University of Turku, Turku, Finland
| | - Jonathan J Danon
- School of Chemistry, The University of Sydney, Sydney, NSW, 2006, Australia
| | - Michael Kassiou
- School of Chemistry, The University of Sydney, Sydney, NSW, 2006, Australia
| | - Anniina Snellman
- PET Preclinical Imaging Laboratory, Turku PET Centre, University of Turku, Tykistökatu 6 A, 20520, Turku, Finland
| | - Olof Solin
- Radiopharmaceutical Chemistry Laboratory, Turku PET Centre, University of Turku, Kiinamyllynkatu 4-8, 20520, Turku, Finland
- Department of Chemistry, University of Turku, Henrikinkatu 2, 20500, Turku, Finland
- Accelerator Laboratory, Turku PET Centre, Åbo Akademi University, Kiinamyllynkatu 4-8, 20520, Turku, Finland
| | - Juha O Rinne
- Turku University Hospital, Turku PET Centre, Kiinamyllynkatu 4-8, 20520, Turku, Finland
- Department of Neurology, Turku University Hospital, Kiinamyllynkatu 4-8, 20520, Turku, Finland
| | - Merja Haaparanta-Solin
- PET Preclinical Imaging Laboratory, Turku PET Centre, University of Turku, Tykistökatu 6 A, 20520, Turku, Finland
- Medicity Research Laboratory, University of Turku, Tykistökatu 6 A, 20520, Turku, Finland
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2
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Tang H, Wei W, Luo Y, Lu X, Chen J, Yang S, Wu F, Zhou H, Ma W, Yang X. P2X7 receptors: a bibliometric review from 2002 to 2023. Purinergic Signal 2024:10.1007/s11302-024-09996-9. [PMID: 38421486 DOI: 10.1007/s11302-024-09996-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Accepted: 02/21/2024] [Indexed: 03/02/2024] Open
Abstract
For many years, there has been ongoing research on the P2X7 receptor (P2X7R). A comprehensive, systematic, and objective evaluation of the scientific output and status of P2X7R will be instrumental in guiding future research directions. This study aims to present the status and trends of P2X7R research from 2002 to 2023. Publications related to P2X7R were retrieved from the Web of Science Core Collection database. Quantitative analysis and visualization tools were Microsoft Excel, VOSviewer, and CiteSpace software. The analysis content included publication trends, literature co-citation, and keywords. 3282 records were included in total, with the majority of papers published within the last 10 years. Based on literature co-citation and keyword analysis, neuroinflammation, neuropathic pain, gastrointestinal diseases, tumor microenvironment, rheumatoid arthritis, age-related macular degeneration, and P2X7R antagonists were considered to be the hotspots and frontiers of P2X7R research. Researchers will get a more intuitive understanding of the status and trends of P2X7R research from this study.
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Affiliation(s)
- Haiting Tang
- School of Health and Rehabilitation, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China
| | - Wei Wei
- School of Health and Rehabilitation, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China
| | - Yu Luo
- School of Health and Rehabilitation, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China
| | - Xiaoqing Lu
- School of Health and Rehabilitation, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China
| | - Jun Chen
- School of Health and Rehabilitation, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China
| | - Shenqiao Yang
- School of Health and Rehabilitation, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China
| | - Fei Wu
- School of Foreign Languages, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China
| | - Haiyan Zhou
- School of Acupuncture and Tuina, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China
| | - Wenbin Ma
- School of Health and Rehabilitation, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China
| | - Xin Yang
- School of Health and Rehabilitation, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China.
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3
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Etebar F, Harkin DG, White AR, Dando SJ. Non-invasive in vivo imaging of brain and retinal microglia in neurodegenerative diseases. Front Cell Neurosci 2024; 18:1355557. [PMID: 38348116 PMCID: PMC10859418 DOI: 10.3389/fncel.2024.1355557] [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: 12/14/2023] [Accepted: 01/10/2024] [Indexed: 02/15/2024] Open
Abstract
Microglia play crucial roles in immune responses and contribute to fundamental biological processes within the central nervous system (CNS). In neurodegenerative diseases, microglia undergo functional changes and can have both protective and pathogenic roles. Microglia in the retina, as an extension of the CNS, have also been shown to be affected in many neurological diseases. While our understanding of how microglia contribute to pathological conditions is incomplete, non-invasive in vivo imaging of brain and retinal microglia in living subjects could provide valuable insights into their role in the neurodegenerative diseases and open new avenues for diagnostic biomarkers. This mini-review provides an overview of the current brain and retinal imaging tools for studying microglia in vivo. We focus on microglia targets, the advantages and limitations of in vivo microglia imaging approaches, and applications for evaluating the pathogenesis of neurological conditions, such as Alzheimer's disease and multiple sclerosis.
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Affiliation(s)
- Fazeleh Etebar
- Centre for Immunology and Infection Control, School of Biomedical Sciences, Faculty of Health, Queensland University of Technology (QUT), Brisbane, QLD, Australia
- Mental Health and Neuroscience Program, QIMR Berghofer Medical Research Institute, Herston, QLD, Australia
| | - Damien G. Harkin
- Centre for Vision and Eye Research, School of Biomedical Sciences, Faculty of Health, Queensland University of Technology (QUT), Brisbane, QLD, Australia
| | - Anthony R. White
- Mental Health and Neuroscience Program, QIMR Berghofer Medical Research Institute, Herston, QLD, Australia
| | - Samantha J. Dando
- Centre for Immunology and Infection Control, School of Biomedical Sciences, Faculty of Health, Queensland University of Technology (QUT), Brisbane, QLD, Australia
- Centre for Vision and Eye Research, School of Biomedical Sciences, Faculty of Health, Queensland University of Technology (QUT), Brisbane, QLD, Australia
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4
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Hu Z, Luo Y, Zhu J, Jiang D, Luo Z, Wu L, Li J, Peng S, Hu J. Role of the P2 × 7 receptor in neurodegenerative diseases and its pharmacological properties. Cell Biosci 2023; 13:225. [PMID: 38093352 PMCID: PMC10720200 DOI: 10.1186/s13578-023-01161-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2023] [Accepted: 11/02/2023] [Indexed: 12/17/2023] Open
Abstract
Neurodegenerative diseases seriously affect patients' physical and mental health, reduce their quality of life, and impose a heavy burden on society. However, their treatment remains challenging. Therefore, exploring factors potentially related to the pathogenesis of neurodegenerative diseases and improving their diagnosis and treatment are urgently needed. Recent studies have shown that P2 × 7R plays a crucial role in regulating neurodegenerative diseases caused by neuroinflammation. P2 × 7R is an adenosine 5'-triphosphate ligand-gated cation channel receptor present in most tissues of the human body. An increase in P2 × 7R levels can affect the progression of neurodegenerative diseases, and the inhibition of P2 × 7R can alleviate neurodegenerative diseases. In this review, we comprehensively describe the biological characteristics (structure, distribution, and function) of this gene, focusing on its potential association with neurodegenerative diseases, and we discuss the pharmacological effects of drugs (P2 × 7R inhibitors) used to treat neurodegenerative diseases.
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Affiliation(s)
- Ziyan Hu
- Department of the second Clinical Medical College, Nanchang University, Nanchang, 330006, China
| | - Yifan Luo
- Department of the second Clinical Medical College, Nanchang University, Nanchang, 330006, China
| | - Jinxi Zhu
- Department of the second Clinical Medical College, Nanchang University, Nanchang, 330006, China
| | - Danling Jiang
- Department of Ultrasound Medicine, The Second Affiliated Hospital of Nanchang University, Nanchang, 330006, China
| | - Zhenzhong Luo
- Department of Anesthesiology, The Second Affiliated Hospital of Nanchang University, Nanchang, 330006, China
| | - Lidong Wu
- Department of Emergency medicine, The Second Affiliated Hospital of Nanchang University, Nanchang, 330006, China
| | - Jin Li
- Department of Emergency medicine, The Second Affiliated Hospital of Nanchang University, Nanchang, 330006, China.
| | - Shengliang Peng
- Department of Anesthesiology, The Second Affiliated Hospital of Nanchang University, Nanchang, 330006, China.
| | - Jialing Hu
- Department of Emergency medicine, The Second Affiliated Hospital of Nanchang University, Nanchang, 330006, China.
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5
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Oh J, Airas L, Harrison D, Järvinen E, Livingston T, Lanker S, Malik RA, Okuda DT, Villoslada P, de Vries HE. Neuroimaging to monitor worsening of multiple sclerosis: advances supported by the grant for multiple sclerosis innovation. Front Neurol 2023; 14:1319869. [PMID: 38107636 PMCID: PMC10722910 DOI: 10.3389/fneur.2023.1319869] [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: 10/11/2023] [Accepted: 11/13/2023] [Indexed: 12/19/2023] Open
Abstract
Key unmet needs in multiple sclerosis (MS) include detection of early pathology, disability worsening independent of relapses, and accurate monitoring of treatment response. Collaborative approaches to address these unmet needs have been driven in part by industry-academic networks and initiatives such as the Grant for Multiple Sclerosis Innovation (GMSI) and Multiple Sclerosis Leadership and Innovation Network (MS-LINK™) programs. We review the application of recent advances, supported by the GMSI and MS-LINK™ programs, in neuroimaging technology to quantify pathology related to central pathology and disease worsening, and potential for their translation into clinical practice/trials. GMSI-supported advances in neuroimaging methods and biomarkers include developments in magnetic resonance imaging, positron emission tomography, ocular imaging, and machine learning. However, longitudinal studies are required to facilitate translation of these measures to the clinic and to justify their inclusion as endpoints in clinical trials of new therapeutics for MS. Novel neuroimaging measures and other biomarkers, combined with artificial intelligence, may enable accurate prediction and monitoring of MS worsening in the clinic, and may also be used as endpoints in clinical trials of new therapies for MS targeting relapse-independent disease pathology.
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Affiliation(s)
- Jiwon Oh
- Division of Neurology, St. Michael’s Hospital, Department of Medicine, University of Toronto, Toronto, ON, Canada
- Department of Neurology, Johns Hopkins University, Baltimore, MD, United States
| | - Laura Airas
- Turku PET Centre, Turku University Hospital and University of Turku, Turku, Finland
- Division of Clinical Neurosciences, Turku University Hospital and University of Turku, Turku, Finland
| | - Daniel Harrison
- Department of Neurology, University of Maryland School of Medicine, Baltimore, MD, United States
- Baltimore VA Medical Center, VA Maryland Healthcare System, Baltimore, MD, United States
| | - Elina Järvinen
- Neurology and Immunology, Medical Unit N&I, Merck OY (an affiliate of Merck KGaA), Espoo, Finland
| | - Terrie Livingston
- Patient Solutions and Center of Excellence Strategic Engagement, EMD Serono, Inc., Rockland, MA, United States
| | - Stefan Lanker
- Neurology & Immunology, US Medical Affairs, EMD Serono Research & Development Institute, Inc., (an affiliate of Merck KGaA), Billerica, MA, United States
| | - Rayaz A. Malik
- Weill Cornell Medicine-Qatar, Research Division, Doha, Qatar
- Institute of Cardiovascular Sciences, University of Manchester, Manchester, United Kingdom
| | - Darin T. Okuda
- Department of Neurology, Neuroinnovation Program, Multiple Sclerosis and Neuroimmunology Imaging Program, Clinical Center for Multiple Sclerosis, UT Southwestern Medical Center, Dallas, TX, United States
| | - Pablo Villoslada
- August Pi i Sunyer Biomedical Research Institute (IDIBAPS), Barcelona, Spain
| | - Helga E. de Vries
- MS Center Amsterdam, Department of Molecular Cell Biology and Immunology, Vrije Universiteit Amsterdam, Amsterdam Neuroscience, Amsterdam University Medical Centers (Amsterdam UMC), Location VUmc, Amsterdam, Netherlands
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6
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Lopresti BJ, Royse SK, Mathis CA, Tollefson SA, Narendran R. Beyond monoamines: I. Novel targets and radiotracers for Positron emission tomography imaging in psychiatric disorders. J Neurochem 2023; 164:364-400. [PMID: 35536762 DOI: 10.1111/jnc.15615] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 04/05/2022] [Accepted: 04/06/2022] [Indexed: 10/18/2022]
Abstract
With the emergence of positron emission tomography (PET) in the late 1970s, psychiatry had access to a tool capable of non-invasive assessment of human brain function. Early applications in psychiatry focused on identifying characteristic brain blood flow and metabolic derangements using radiotracers such as [15 O]H2 O and [18 F]FDG. Despite the success of these techniques, it became apparent that more specific probes were needed to understand the neurochemical bases of psychiatric disorders. The first neurochemical PET imaging probes targeted sites of action of neuroleptic (dopamine D2 receptors) and psychoactive (serotonin receptors) drugs. Based on the centrality of monoamine dysfunction in psychiatric disorders and the measured success of monoamine-enhancing drugs in treating them, the next 30 years witnessed the development of an armamentarium of PET radiopharmaceuticals and imaging methodologies for studying monoamines. Continued development of monoamine-enhancing drugs over this time however was less successful, realizing only modest gains in efficacy and tolerability. As patent protection for many widely prescribed and profitable psychiatric drugs lapsed, drug development pipelines shifted away from monoamines in search of novel targets with the promises of improved efficacy, or abandoned altogether. Over this period, PET radiopharmaceutical development activities closely paralleled drug development priorities resulting in the development of new PET imaging agents for non-monoamine targets. Part one of this review will briefly survey novel PET imaging targets with relevance to the field of psychiatry, which include the metabotropic glutamate receptor type 5 (mGluR5), purinergic P2 X7 receptor, type 1 cannabinoid receptor (CB1 ), phosphodiesterase 10A (PDE10A), and describe radiotracers developed for these and other targets that have matured to human subject investigations. Current limitations of the targets and techniques will also be discussed.
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Affiliation(s)
- Brian J Lopresti
- Departments of Radiology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Sarah K Royse
- Departments of Radiology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Chester A Mathis
- Departments of Radiology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Savannah A Tollefson
- Departments of Radiology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Rajesh Narendran
- Departments of Radiology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA.,Departments of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
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7
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Brumberg J, Aarnio R, Forsberg A, Marjamäki P, Kerstens V, Moein MM, Nag S, Wahlroos S, Kassiou M, Windhorst AD, Halldin C, Haaparanta-Solin M, Fazio P, Oikonen V, Rinne JO, Varrone A. Quantification of the purinergic P2X 7 receptor with [ 11C]SMW139 improves through correction for brain-penetrating radiometabolites. J Cereb Blood Flow Metab 2023; 43:258-268. [PMID: 36163685 PMCID: PMC9903223 DOI: 10.1177/0271678x221126830] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
The membrane-based purinergic 7 receptor (P2X7R) is expressed on activated microglia and the target of the radioligand [11C]SMW139 for in vivo assessment of neuroinflammation. This study investigated the contribution of radiolabelled metabolites which potentially affect its quantification. Ex vivo high-performance liquid chromatography with a radio detector (radioHPLC) was used to evaluate the parent and radiometabolite fractions of [11C]SMW139 in the brain and plasma of eleven mice. Twelve healthy humans underwent 90-min [11C]SMW139 brain PET with arterial blood sampling and radiometabolite analysis. The volume of distribution was estimated by using one- and two- tissue compartment (TCM) modeling with single (VT) and dual (VTp) input functions. RadioHPLC showed three major groups of radiometabolite peaks with increasing concentrations in the plasma of all mice and humans. Two radiometabolite peaks were also visible in mice brain homogenates and therefore considered for dual input modeling in humans. 2TCM with single input function provided VT estimates with a wide range (0.10-10.74) and high coefficient of variation (COV: 159.9%), whereas dual input function model showed a narrow range of VTp estimates (0.04-0.24; COV: 33.3%). In conclusion, compartment modeling with correction for brain-penetrant radiometabolites improves the in vivo quantification of [11C]SMW139 binding to P2X7R in the human brain.
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Affiliation(s)
- Joachim Brumberg
- Centre for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet & Stockholm Health Care Services, Stockholm, Sweden.,Department of Nuclear Medicine, Medical Center - University of Freiburg, Freiburg, Germany
| | - Richard Aarnio
- Turku PET Centre, University of Turku and Turku University Hospital, Turku, Finland
| | - Anton Forsberg
- Centre for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet & Stockholm Health Care Services, Stockholm, Sweden
| | - Päivi Marjamäki
- Turku PET Centre, University of Turku and Turku University Hospital, Turku, Finland
| | - Vera Kerstens
- Centre for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet & Stockholm Health Care Services, Stockholm, Sweden
| | - Mohammad M Moein
- Centre for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet & Stockholm Health Care Services, Stockholm, Sweden
| | - Sangram Nag
- Centre for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet & Stockholm Health Care Services, Stockholm, Sweden
| | - Saara Wahlroos
- Turku PET Centre, University of Turku and Turku University Hospital, Turku, Finland
| | - Michael Kassiou
- School of Chemistry, The University of Sydney, Sydney, Australia
| | - Albert D Windhorst
- Department of Radiology and Nuclear Medicine, Amsterdam UMC location Vrije Universiteit Amsterdam, Amsterdam, The Netherlands.,Amsterdam Neuroscience, Brain Imaging, Amsterdam, The Netherlands
| | - Christer Halldin
- Centre for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet & Stockholm Health Care Services, Stockholm, Sweden
| | | | - Patrik Fazio
- Centre for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet & Stockholm Health Care Services, Stockholm, Sweden.,Department of Neurology, Karolinska University Hospital, Stockholm, Sweden
| | - Vesa Oikonen
- Turku PET Centre, University of Turku and Turku University Hospital, Turku, Finland
| | - Juha O Rinne
- Turku PET Centre, University of Turku and Turku University Hospital, Turku, Finland
| | - Andrea Varrone
- Centre for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet & Stockholm Health Care Services, Stockholm, Sweden
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8
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Buttigieg E, Scheller A, El Waly B, Kirchhoff F, Debarbieux F. Contribution of Intravital Neuroimaging to Study Animal Models of Multiple Sclerosis. Neurotherapeutics 2023; 20:22-38. [PMID: 36653665 PMCID: PMC10119369 DOI: 10.1007/s13311-022-01324-6] [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] [Accepted: 10/23/2022] [Indexed: 01/20/2023] Open
Abstract
Multiple sclerosis (MS) is a complex and long-lasting neurodegenerative disease of the central nervous system (CNS), characterized by the loss of myelin within the white matter and cortical fibers, axonopathy, and inflammatory responses leading to consequent sensory-motor and cognitive deficits of patients. While complete resolution of the disease is not yet a reality, partial tissue repair has been observed in patients which offers hope for therapeutic strategies. To address the molecular and cellular events of the pathomechanisms, a variety of animal models have been developed to investigate distinct aspects of MS disease. Recent advances of multiscale intravital imaging facilitated the direct in vivo analysis of MS in the animal models with perspective of clinical transfer to patients. This review gives an overview of MS animal models, focusing on the current imaging modalities at the microscopic and macroscopic levels and emphasizing the importance of multimodal approaches to improve our understanding of the disease and minimize the use of animals.
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Affiliation(s)
- Emeline Buttigieg
- Molecular Physiology, Center for Integrative Physiology and Molecular Medicine (CIPMM), University of Saarland, 66421, Homburg, Germany
- Institut des Neurosciences de la Timone (INT), Aix-Marseille Université, CNRS UMR7289, 13005, Marseille, France
- Centre Européen de Recherche en Imagerie Médicale (CERIMED), Aix-Marseille Université, Marseille, France
| | - Anja Scheller
- Molecular Physiology, Center for Integrative Physiology and Molecular Medicine (CIPMM), University of Saarland, 66421, Homburg, Germany
| | - Bilal El Waly
- Institut des Neurosciences de la Timone (INT), Aix-Marseille Université, CNRS UMR7289, 13005, Marseille, France
- Centre Européen de Recherche en Imagerie Médicale (CERIMED), Aix-Marseille Université, Marseille, France
| | - Frank Kirchhoff
- Molecular Physiology, Center for Integrative Physiology and Molecular Medicine (CIPMM), University of Saarland, 66421, Homburg, Germany
| | - Franck Debarbieux
- Institut des Neurosciences de la Timone (INT), Aix-Marseille Université, CNRS UMR7289, 13005, Marseille, France.
- Centre Européen de Recherche en Imagerie Médicale (CERIMED), Aix-Marseille Université, Marseille, France.
- Institut Universitaire de France (IUF), Paris, France.
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9
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Fu Z, Lin Q, Xu Z, Fu W, Shi D, Cheng Y, Yang T, Liu G, Shi H, Cheng D. Longitudinal Positron Emission Tomography Imaging with P2X7 Receptor-Specific Radioligand 18F-FTTM in a Kainic Acid Rat Model of Temporal Lobe Epilepsy. ACS Chem Neurosci 2022; 13:3512-3522. [PMID: 36383137 DOI: 10.1021/acschemneuro.2c00557] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
P2X7 receptors (P2X7R), as a brain inflammation biomarker, play important roles in the epileptogenic progress. Mounting evidence supports their activation in the brain during epilepsy, and inhibition of the P2X7 receptor reduces the seizure frequency and severity. In this study, we investigate P2X7R-targeted (18F-FTTM) position emission tomography (PET) imaging in a rat model of temporal lobe epilepsy to obtain further insights into the role of P2X7R during epileptogenesis. 18F-FTTM (5-10% radiochemical yield, over 99% radiochemical purity, and a specific activity of 270-300 MBq/nmol, n = 6, EOS) was first synthesized. Then, the rat models induced by intrahippocampal injection of saline (1.2 μL, n = 15) or kainic acid (1.2 μL, 0.5 μg/μL, n = 35) were examined using 18F-FTTM Micro-PET/CT longitudinal imaging, respectively. The imaging results showed that increases in the 18F-FTTM uptake was evident after status epilepticus (SE) in the epileptogenesis-associated brain regions, such as the hippocampus, amygdala, or temporal cortex, and this peaked during the latent period. The histopathological analysis revealed that the P2X7R PET uptake reached a peak at 7 days after SE and was mostly related to microglial activation. Thus, P2X7R-targeted PET imaging agent 18F-FTTM may act as a useful tool for identifying brain inflammation during epilepsy. P2X7R PET is a highly potent longitudinal biomarker of epilepsy and could be of interest to determine the therapeutic windows in epilepsy and to monitor treatment response, and it warrants further clinical studies.
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Affiliation(s)
- Zhequan Fu
- Department of Nuclear Medicine, Zhongshan Hospital, Fudan University, Shanghai 200032, China.,Institute of Nuclear Medicine, Fudan University, Shanghai 200032, China.,Shanghai Institute of Medical Imaging, Shanghai 200032, China
| | - Qingyu Lin
- Department of Nuclear Medicine, Zhongshan Hospital, Fudan University, Shanghai 200032, China.,Institute of Nuclear Medicine, Fudan University, Shanghai 200032, China.,Shanghai Institute of Medical Imaging, Shanghai 200032, China
| | - Zhan Xu
- Department of Nuclear Medicine, Zhongshan Hospital, Fudan University, Shanghai 200032, China.,Institute of Nuclear Medicine, Fudan University, Shanghai 200032, China.,Shanghai Institute of Medical Imaging, Shanghai 200032, China
| | - Wenhui Fu
- Department of Nuclear Medicine, Zhongshan Hospital, Fudan University, Shanghai 200032, China.,Institute of Nuclear Medicine, Fudan University, Shanghai 200032, China.,Shanghai Institute of Medical Imaging, Shanghai 200032, China
| | - Dai Shi
- Department of Nuclear Medicine, Zhongshan Hospital, Fudan University, Shanghai 200032, China.,Institute of Nuclear Medicine, Fudan University, Shanghai 200032, China.,Shanghai Institute of Medical Imaging, Shanghai 200032, China
| | - Yuan Cheng
- Department of Nuclear Medicine, Zhongshan Hospital, Fudan University, Shanghai 200032, China.,Institute of Nuclear Medicine, Fudan University, Shanghai 200032, China.,Shanghai Institute of Medical Imaging, Shanghai 200032, China
| | - Tingting Yang
- Department of Nuclear Medicine, Zhongshan Hospital, Fudan University, Shanghai 200032, China.,Institute of Nuclear Medicine, Fudan University, Shanghai 200032, China.,Shanghai Institute of Medical Imaging, Shanghai 200032, China
| | - Guobing Liu
- Department of Nuclear Medicine, Zhongshan Hospital, Fudan University, Shanghai 200032, China.,Institute of Nuclear Medicine, Fudan University, Shanghai 200032, China.,Shanghai Institute of Medical Imaging, Shanghai 200032, China
| | - Hongcheng Shi
- Department of Nuclear Medicine, Zhongshan Hospital, Fudan University, Shanghai 200032, China.,Institute of Nuclear Medicine, Fudan University, Shanghai 200032, China.,Shanghai Institute of Medical Imaging, Shanghai 200032, China
| | - Dengfeng Cheng
- Department of Nuclear Medicine, Zhongshan Hospital, Fudan University, Shanghai 200032, China.,Institute of Nuclear Medicine, Fudan University, Shanghai 200032, China.,Shanghai Institute of Medical Imaging, Shanghai 200032, China
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10
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Huang J. Novel brain PET imaging agents: Strategies for imaging neuroinflammation in Alzheimer’s disease and mild cognitive impairment. Front Immunol 2022; 13:1010946. [PMID: 36211392 PMCID: PMC9537554 DOI: 10.3389/fimmu.2022.1010946] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Accepted: 09/06/2022] [Indexed: 11/25/2022] Open
Abstract
Alzheimer’s disease (AD) is a devastating neurodegenerative disease with a concealed onset and continuous deterioration. Mild cognitive impairment (MCI) is the prodromal stage of AD. Molecule-based imaging with positron emission tomography (PET) is critical in tracking pathophysiological changes among AD and MCI patients. PET with novel targets is a promising approach for diagnostic imaging, particularly in AD patients. Our present review overviews the current status and applications of in vivo molecular imaging toward neuroinflammation. Although radiotracers can remarkably diagnose AD and MCI patients, a variety of limitations prevent the recommendation of a single technique. Recent studies examining neuroinflammation PET imaging suggest an alternative approach to evaluate disease progression. This review concludes that PET imaging towards neuroinflammation is considered a promising approach to deciphering the enigma of the pathophysiological process of AD and MCI.
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11
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Cao L, Kong Y, Ji B, Ren Y, Guan Y, Ni R. Positron Emission Tomography in Animal Models of Tauopathies. Front Aging Neurosci 2022; 13:761913. [PMID: 35082657 PMCID: PMC8784812 DOI: 10.3389/fnagi.2021.761913] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Accepted: 11/30/2021] [Indexed: 12/18/2022] Open
Abstract
The microtubule-associated protein tau (MAPT) plays an important role in Alzheimer's disease and primary tauopathy diseases. The abnormal accumulation of tau contributes to the development of neurotoxicity, inflammation, neurodegeneration, and cognitive deficits in tauopathy diseases. Tau synergically interacts with amyloid-beta in Alzheimer's disease leading to detrimental consequence. Thus, tau has been an important target for therapeutics development for Alzheimer's disease and primary tauopathy diseases. Tauopathy animal models recapitulating the tauopathy such as transgenic, knock-in mouse and rat models have been developed and greatly facilitated the understanding of disease mechanisms. The advance in PET and imaging tracers have enabled non-invasive detection of the accumulation and spread of tau, the associated microglia activation, metabolic, and neurotransmitter receptor alterations in disease animal models. In vivo microPET studies on mouse or rat models of tauopathy have provided significant insights into the phenotypes and time course of pathophysiology of these models and allowed the monitoring of treatment targeting at tau. In this study, we discuss the utilities of PET and recently developed tracers for evaluating the pathophysiology in tauopathy animal models. We point out the outstanding challenges and propose future outlook in visualizing tau-related pathophysiological changes in brain of tauopathy disease animal models.
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Affiliation(s)
- Lei Cao
- Institute for Regenerative Medicine, University of Zurich, Zurich, Switzerland
- Changes Technology Corporation Ltd., Shanghai, China
| | - Yanyan Kong
- PET Center, Huashan Hospital, Fudan University, Shanghai, China
| | - Bin Ji
- Department of Radiopharmacy and Molecular Imaging, School of Pharmacy, Fudan University, Shanghai, China
| | - Yutong Ren
- Guangdong Robotics Association, Guangzhou, China
| | - Yihui Guan
- PET Center, Huashan Hospital, Fudan University, Shanghai, China
| | - Ruiqing Ni
- Institute for Regenerative Medicine, University of Zurich, Zurich, Switzerland
- Institute for Biomedical Engineering, ETH Zurich and University of Zurich, Zurich, Switzerland
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12
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Abstract
The P2X7 receptor has been proposed as a novel drug target for different types of diseases associated with inflammation, including brain diseases, peripheral inflammation, and cancers. Structurally diverse P2X7 receptor antagonists, mainly negative allosteric modulators (NAMs), have been developed in recent years, and several P2X7 receptor antagonists are currently evaluated in clinical trials. The P2X7 receptor requires high micro- to even millimolar ATP concentrations to be activated. Selective agonists for the P2X7 receptor are not available. Positive allosteric modulators (PAMs) have been described, but PAMs with high potency and selectivity are still lacking. This chapter discusses medicinal chemistry approaches toward the development of P2X7 receptor modulators and presents a selection of recommended tool compounds for studying P2X7 receptors in humans and rodents.
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Affiliation(s)
- Christa E Müller
- Pharmaceutical & Medicinal Chemistry, PharmaCenter Bonn, Pharmaceutical Institute, University of Bonn, Bonn, Germany.
| | - Vigneshwaran Namasivayam
- Pharmaceutical & Medicinal Chemistry, PharmaCenter Bonn, Pharmaceutical Institute, University of Bonn, Bonn, Germany
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13
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van der Wildt B, Janssen B, Pekošak A, Stéen EJL, Schuit RC, Kooijman EJM, Beaino W, Vugts DJ, Windhorst AD. Novel Thienopyrimidine-Based PET Tracers for P2Y 12 Receptor Imaging in the Brain. ACS Chem Neurosci 2021; 12:4465-4474. [PMID: 34757711 PMCID: PMC8640995 DOI: 10.1021/acschemneuro.1c00641] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
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The P2Y12 receptor (P2Y12R) is uniquely expressed
on microglia in the brain, and its expression level directly depends
on the microglial activation state. Therefore, P2Y12R provides
a promising imaging marker for distinguishing the pro- and anti-inflammatory
microglial phenotypes, both of which play crucial roles in neuroinflammatory
diseases. In this study, three P2Y12R antagonists were
selected from the literature, radiolabeled with carbon-11 or fluorine-18,
and evaluated in healthy Wistar rats. Brain imaging was performed
with and without blocking of efflux transporters P-glycoprotein and breast cancer resistance protein using tariquidar.
Low brain uptake in healthy rats was observed for all tracers at baseline
conditions, whereas blocking of efflux transporters resulted in a
strong (6–7 fold) increase in brain uptake for both of them.
Binding of the most promising tracer, [18F]3, was further evaluated by in vitro autoradiography on rat brain
sections, ex vivo metabolite studies, and in vivo P2Y12R blocking studies. In vitro binding of [18F]3 on rat brain sections indicated high P2Y12R targeting
with approximately 70% selective and specific binding. At 60 min post-injection,
over 95% of radioactivity in the brain accounted for an intact tracer.
In blood plasma, still 40% intact tracer was found, and formed metabolites
did not enter the brain. A moderate P2Y12R blocking effect
was observed in vivo by positron emission tomography (PET) imaging
with [18F]3 (p = 0.04). To
conclude, three potential P2Y12R PET tracers were obtained
and analyzed for P2Y12R targeting in the brain. Unfortunately,
the brain uptake appeared low. Future work will focus on the design
of P2Y12R inhibitors with improved physicochemical characteristics
to reduce efflux transport and increase brain penetration.
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Affiliation(s)
- Berend van der Wildt
- Department of Radiology & Nuclear Medicine, Neuroscience Amsterdam, Amsterdam UMC, Vrije Universiteit Amsterdam, De Boelelaan 1117, 1081HV Amsterdam, The Netherlands
| | - Bieneke Janssen
- Department of Radiology & Nuclear Medicine, Neuroscience Amsterdam, Amsterdam UMC, Vrije Universiteit Amsterdam, De Boelelaan 1117, 1081HV Amsterdam, The Netherlands
| | - Aleksandra Pekošak
- Department of Radiology & Nuclear Medicine, Neuroscience Amsterdam, Amsterdam UMC, Vrije Universiteit Amsterdam, De Boelelaan 1117, 1081HV Amsterdam, The Netherlands
| | - E. Johanna L. Stéen
- Department of Radiology & Nuclear Medicine, Neuroscience Amsterdam, Amsterdam UMC, Vrije Universiteit Amsterdam, De Boelelaan 1117, 1081HV Amsterdam, The Netherlands
| | - Robert C. Schuit
- Department of Radiology & Nuclear Medicine, Neuroscience Amsterdam, Amsterdam UMC, Vrije Universiteit Amsterdam, De Boelelaan 1117, 1081HV Amsterdam, The Netherlands
| | - Esther J. M. Kooijman
- Department of Radiology & Nuclear Medicine, Neuroscience Amsterdam, Amsterdam UMC, Vrije Universiteit Amsterdam, De Boelelaan 1117, 1081HV Amsterdam, The Netherlands
| | - Wissam Beaino
- Department of Radiology & Nuclear Medicine, Neuroscience Amsterdam, Amsterdam UMC, Vrije Universiteit Amsterdam, De Boelelaan 1117, 1081HV Amsterdam, The Netherlands
| | - Danielle J. Vugts
- Department of Radiology & Nuclear Medicine, Neuroscience Amsterdam, Amsterdam UMC, Vrije Universiteit Amsterdam, De Boelelaan 1117, 1081HV Amsterdam, The Netherlands
| | - Albert D. Windhorst
- Department of Radiology & Nuclear Medicine, Neuroscience Amsterdam, Amsterdam UMC, Vrije Universiteit Amsterdam, De Boelelaan 1117, 1081HV Amsterdam, The Netherlands
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14
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Zhou R, Ji B, Kong Y, Qin L, Ren W, Guan Y, Ni R. PET Imaging of Neuroinflammation in Alzheimer's Disease. Front Immunol 2021; 12:739130. [PMID: 34603323 PMCID: PMC8481830 DOI: 10.3389/fimmu.2021.739130] [Citation(s) in RCA: 46] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2021] [Accepted: 08/27/2021] [Indexed: 12/15/2022] Open
Abstract
Neuroinflammation play an important role in Alzheimer's disease pathogenesis. Advances in molecular imaging using positron emission tomography have provided insights into the time course of neuroinflammation and its relation with Alzheimer's disease central pathologies in patients and in animal disease models. Recent single-cell sequencing and transcriptomics indicate dynamic disease-associated microglia and astrocyte profiles in Alzheimer's disease. Mitochondrial 18-kDa translocator protein is the most widely investigated target for neuroinflammation imaging. New generation of translocator protein tracers with improved performance have been developed and evaluated along with tau and amyloid imaging for assessing the disease progression in Alzheimer's disease continuum. Given that translocator protein is not exclusively expressed in glia, alternative targets are under rapid development, such as monoamine oxidase B, matrix metalloproteinases, colony-stimulating factor 1 receptor, imidazoline-2 binding sites, cyclooxygenase, cannabinoid-2 receptor, purinergic P2X7 receptor, P2Y12 receptor, the fractalkine receptor, triggering receptor expressed on myeloid cells 2, and receptor for advanced glycation end products. Promising targets should demonstrate a higher specificity for cellular locations with exclusive expression in microglia or astrocyte and activation status (pro- or anti-inflammatory) with highly specific ligand to enable in vivo brain imaging. In this review, we summarised recent advances in the development of neuroinflammation imaging tracers and provided an outlook for promising targets in the future.
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Affiliation(s)
- Rong Zhou
- Department of Nephrology, Yangpu Hospital, School of Medicine, Tongji University, Shanghai, China
| | - Bin Ji
- Department of Radiopharmacy and Molecular Imaging, School of Pharmacy, Fudan University, Shanghai, China
| | - Yanyan Kong
- Positron Emission Tomography (PET) Center, Huashan Hospital, Fudan University, Shanghai, China
| | - Limei Qin
- Inner Mongolia Baicaotang Qin Chinese Mongolia Hospital, Hohhot, China
| | - Wuwei Ren
- School of Information Science and Technology, Shanghaitech University, Shanghai, China
| | - Yihui Guan
- Positron Emission Tomography (PET) Center, Huashan Hospital, Fudan University, Shanghai, China
| | - Ruiqing Ni
- Institute for Regenerative Medicine, University of Zurich, Zurich, Switzerland
- Institute for Biomedical Engineering, University of Zurich & Eidgenössische Technische Hochschule Zürich (ETH Zurich), Zurich, Switzerland
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15
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Beaino W, Janssen B, Vugts DJ, de Vries HE, Windhorst AD. Towards PET imaging of the dynamic phenotypes of microglia. Clin Exp Immunol 2021; 206:282-300. [PMID: 34331705 PMCID: PMC8561701 DOI: 10.1111/cei.13649] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 07/21/2021] [Accepted: 07/21/2021] [Indexed: 02/06/2023] Open
Abstract
There is increasing evidence showing the heterogeneity of microglia activation in neuroinflammatory and neurodegenerative diseases. It has been hypothesized that pro‐inflammatory microglia are detrimental and contribute to disease progression, while anti‐inflammatory microglia play a role in damage repair and remission. The development of therapeutics targeting the deleterious glial activity and modulating it into a regenerative phenotype relies heavily upon a clearer understanding of the microglia dynamics during disease progression and the ability to monitor therapeutic outcome in vivo. To that end, molecular imaging techniques are required to assess microglia dynamics and study their role in disease progression as well as to evaluate the outcome of therapeutic interventions. Positron emission tomography (PET) is such a molecular imaging technique, and provides unique capabilities for non‐invasive quantification of neuroinflammation and has the potential to discriminate between microglia phenotypes and define their role in the disease process. However, several obstacles limit the possibility for selective in vivo imaging of microglia phenotypes mainly related to the poor characterization of specific targets that distinguish the two ends of the microglia activation spectrum and lack of suitable tracers. PET tracers targeting translocator protein 18 kDa (TSPO) have been extensively explored, but despite the success in evaluating neuroinflammation they failed to discriminate between microglia activation statuses. In this review, we highlight the current knowledge on the microglia phenotypes in the major neuroinflammatory and neurodegenerative diseases. We also discuss the current and emerging PET imaging targets, the tracers and their potential in discriminating between the pro‐ and anti‐inflammatory microglia activation states.
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Affiliation(s)
- Wissam Beaino
- Department of Radiology and Nuclear Medicine, Tracer Center Amsterdam, Amsterdam UMC, Vrije Universiteit, Amsterdam, the Netherlands
| | - Bieneke Janssen
- Department of Radiology and Nuclear Medicine, Tracer Center Amsterdam, Amsterdam UMC, Vrije Universiteit, Amsterdam, the Netherlands
| | - Danielle J Vugts
- Department of Radiology and Nuclear Medicine, Tracer Center Amsterdam, Amsterdam UMC, Vrije Universiteit, Amsterdam, the Netherlands
| | - Helga E de Vries
- Department of Molecular Cell Biology and Immunology, MS Center Amsterdam, Amsterdam Neuroscience, Amsterdam UMC, Vrije Universiteit, Amsterdam, the Netherlands
| | - Albert D Windhorst
- Department of Radiology and Nuclear Medicine, Tracer Center Amsterdam, Amsterdam UMC, Vrije Universiteit, Amsterdam, the Netherlands
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