1
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Chauveau F, Winkeler A, Chalon S, Boutin H, Becker G. PET imaging of neuroinflammation: any credible alternatives to TSPO yet? Mol Psychiatry 2024:10.1038/s41380-024-02656-9. [PMID: 38997465 DOI: 10.1038/s41380-024-02656-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Revised: 06/26/2024] [Accepted: 07/01/2024] [Indexed: 07/14/2024]
Abstract
Over the last decades, the role of neuroinflammation in neuropsychiatric conditions has attracted an exponentially growing interest. A key driver for this trend was the ability to image brain inflammation in vivo using PET radioligands targeting the Translocator Protein 18 kDa (TSPO), which is known to be expressed in activated microglia and astrocytes upon inflammatory events as well as constitutively in endothelial cells. TSPO is a mitochondrial protein that is expressed mostly by microglial cells upon activation but is also expressed by astrocytes in some conditions and constitutively by endothelial cells. Therefore, our current understanding of neuroinflammation dynamics is hampered by the lack of alternative targets available for PET imaging. We performed a systematic search and review on radiotracers developed for neuroinflammation PET imaging apart from TSPO. The following targets of interest were identified through literature screening (including previous narrative reviews): P2Y12R, P2X7R, CSF1R, COX (microglial targets), MAO-B, I2BS (astrocytic targets), CB2R & S1PRs (not specific of a single cell type). We determined the level of development and provided a scoping review for each target. Strikingly, astrocytic biomarker MAO-B has progressed in clinical investigations the furthest, while few radiotracers (notably targeting S1P1Rs, CSF1R) are being implemented in clinical investigations. Other targets such as CB2R and P2X7R have proven disappointing in clinical studies (e.g. poor signal, lack of changes in disease conditions, etc.). While astrocytic targets are promising, development of new biomarkers and tracers specific for microglial activation has proven challenging.
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Affiliation(s)
- Fabien Chauveau
- Université Claude Bernard Lyon 1, Centre de Recherche en Neurosciences de Lyon, Inserm U1028, CNRS UMR5292, BIORAN, Groupement Hospitalier Est - CERMEP, 59 boulevard Pinel, 69677, Bron, Cedex, France
| | - Alexandra Winkeler
- Université Paris-Saclay, Inserm, CNRS, CEA, BioMaps, Service Hospitalier Frédéric Joliot, 4 place du général Leclerc, 91401, Orsay, France
| | - Sylvie Chalon
- UMR 1253 iBrain, Université de Tours - INSERM, Bâtiment Planiol, UFR de Médecine, 10 Boulevard Tonnellé, 37032, Tours, Cedex 01, France
| | - Hervé Boutin
- UMR 1253 iBrain, Université de Tours - INSERM, Bâtiment Planiol, UFR de Médecine, 10 Boulevard Tonnellé, 37032, Tours, Cedex 01, France.
| | - Guillaume Becker
- Université Claude Bernard Lyon 1, Centre de Recherche en Neurosciences de Lyon, Inserm U1028, CNRS UMR5292, BIORAN, Groupement Hospitalier Est - CERMEP, 59 boulevard Pinel, 69677, Bron, Cedex, France
- Agence Nationale de Sécurité Sanitaire de l'Alimentation, de l'Environnement et du Travail, 14 rue Pierre et Marie Curie, 94701, Maisons-Alfort, Cedex, France
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2
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Xie L, Zhao J, Li Y, Bai J. PET brain imaging in neurological disorders. Phys Life Rev 2024; 49:100-111. [PMID: 38574584 DOI: 10.1016/j.plrev.2024.03.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2024] [Accepted: 03/20/2024] [Indexed: 04/06/2024]
Abstract
Brain disorders are a series of conditions with damage or loss of neurons, such as Parkinson's disease (PD), Alzheimer's disease (AD), or drug dependence. These individuals have gradual deterioration of cognitive, motor, and other central nervous system functions affected. This degenerative trajectory is intricately associated with dysregulations in neurotransmitter systems. Positron Emission Tomography (PET) imaging, employing radiopharmaceuticals and molecular imaging techniques, emerges as a crucial tool for detecting brain biomarkers. It offers invaluable insights for early diagnosis and distinguishing brain disorders. This article comprehensively reviews the application and progress of conventional and novel PET imaging agents in diagnosing brain disorders. Furthermore, it conducts a thorough analysis on merits and limitations. The article also provides a forward-looking perspective in the future development directions of PET imaging agents for diagnosing brain disorders and proposes potential innovative strategies. It aims to furnish clinicians and researchers with an all-encompassing overview of the latest advancements and forthcoming trends in the utilization of PET imaging for diagnosing brain disorders.
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Affiliation(s)
- Lijun Xie
- Faculty of Life science and Technology, Kunming University of Science and Technology, Kunming 650500, PR China; Laboratory of Molecular Neurobiology, Medical school, Kunming University of Science and Technology, Kunming 650500, PR China; Department of Nuclear Medicine, First Affiliated Hospital of Kunming Medical University, Kunming 650032, PR China
| | - Jihua Zhao
- Department of Nuclear Medicine, First Affiliated Hospital of Kunming Medical University, Kunming 650032, PR China
| | - Ye Li
- Laboratory of Molecular Neurobiology, Medical school, Kunming University of Science and Technology, Kunming 650500, PR China.
| | - Jie Bai
- Laboratory of Molecular Neurobiology, Medical school, Kunming University of Science and Technology, Kunming 650500, PR China.
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3
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Giladi M, Montgomery AP, Kassiou M, Danon JJ. Structure-based drug design for TSPO: Challenges and opportunities. Biochimie 2024:S0300-9084(24)00120-2. [PMID: 38782353 DOI: 10.1016/j.biochi.2024.05.018] [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: 02/19/2024] [Revised: 04/27/2024] [Accepted: 05/21/2024] [Indexed: 05/25/2024]
Abstract
The translocator protein 18 kDa (TSPO) is an evolutionarily conserved mitochondrial transmembrane protein implicated in various neuropathologies and inflammatory conditions, making it a longstanding diagnostic and therapeutic target of interest. Despite the development of various classes of TSPO ligand chemotypes, and the elucidation of bacterial and non-human mammalian experimental structures, many unknowns exist surrounding its differential structural and functional features in health and disease. There are several limitations associated with currently used computational methodologies for modelling the native structure and ligand-binding behaviour of this enigmatic protein. In this perspective, we provide a critical analysis of the developments in the uses of these methods, outlining their uses, inherent limitations, and continuing challenges. We offer suggestions of unexplored opportunities that exist in the use of computational methodologies which offer promise for enhancing our understanding of the TSPO.
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Affiliation(s)
- Mia Giladi
- School of Chemistry, The University of Sydney, 2050, Sydney, NSW, Australia
| | | | - Michael Kassiou
- School of Chemistry, The University of Sydney, 2050, Sydney, NSW, Australia.
| | - Jonathan J Danon
- School of Chemistry, The University of Sydney, 2050, Sydney, NSW, Australia.
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4
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Chalet L, Debatisse J, Wateau O, Boutelier T, Wiart M, Costes N, Mérida I, Redouté J, Langlois JB, Lancelot S, Léon C, Cho TH, Mechtouff L, Eker OF, Nighoghossian N, Canet-Soulas E, Becker G. The PREMISE database of 20 Macaca fascicularis PET/MRI brain images available for research. Lab Anim (NY) 2024; 53:13-17. [PMID: 37996697 PMCID: PMC10766538 DOI: 10.1038/s41684-023-01289-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Accepted: 10/17/2023] [Indexed: 11/25/2023]
Abstract
Non-human primate studies are unique in translational research, especially in neurosciences where neuroimaging approaches are the preferred methods used for cross-species comparative neurosciences. In this regard, neuroimaging database development and sharing are encouraged to increase the number of subjects available to the community, while limiting the number of animals used in research. Here we present a simultaneous positron emission tomography (PET)/magnetic resonance (MR) dataset of 20 Macaca fascicularis images structured according to the Brain Imaging Data Structure standards. This database contains multiple MR imaging sequences (anatomical, diffusion and perfusion imaging notably), as well as PET perfusion and inflammation imaging using respectively [15O]H2O and [11C]PK11195 radiotracers. We describe the pipeline method to assemble baseline data from various cohorts and qualitatively assess all the data using signal-to-noise and contrast-to-noise ratios as well as the median of intensity and the pseudo-noise-equivalent-count rate (dynamic and at maximum) for PET data. Our study provides a detailed example for quality control integration in preclinical and translational PET/MR studies with the aim of increasing reproducibility. The PREMISE database is stored and available through the PRIME-DE consortium repository.
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Affiliation(s)
- Lucie Chalet
- CarMeN Laboratory, Université Claude Bernard Lyon 1, INSERM U1060, INRA U1397, Lyon, France
- Olea Medical, La Ciotat, France
| | - Justine Debatisse
- Institut des Sciences Cognitives Marc Jeannerod (ISCMJ), UMR 5229 CNRS, Bron Cedex, France
| | | | | | - Marlène Wiart
- CarMeN Laboratory, Université Claude Bernard Lyon 1, INSERM U1060, INRA U1397, Lyon, France
| | | | | | | | | | | | - Christelle Léon
- CarMeN Laboratory, Université Claude Bernard Lyon 1, INSERM U1060, INRA U1397, Lyon, France
| | - Tae-Hee Cho
- CarMeN Laboratory, Université Claude Bernard Lyon 1, INSERM U1060, INRA U1397, Lyon, France
- Hospices Civils de Lyon, Lyon, France
| | - Laura Mechtouff
- CarMeN Laboratory, Université Claude Bernard Lyon 1, INSERM U1060, INRA U1397, Lyon, France
- Hospices Civils de Lyon, Lyon, France
| | - Omer Faruk Eker
- Hospices Civils de Lyon, Lyon, France
- CREATIS, CNRS UMR 5220, INSERM U1206, Université Lyon 1, INSA Lyon, Bât. Blaise Pascal, Villeurbanne, France
| | - Norbert Nighoghossian
- CarMeN Laboratory, Université Claude Bernard Lyon 1, INSERM U1060, INRA U1397, Lyon, France
- Hospices Civils de Lyon, Lyon, France
| | - Emmanuelle Canet-Soulas
- CarMeN Laboratory, Université Claude Bernard Lyon 1, INSERM U1060, INRA U1397, Lyon, France.
| | - Guillaume Becker
- CarMeN Laboratory, Université Claude Bernard Lyon 1, INSERM U1060, INRA U1397, Lyon, France.
- Lyon Neuroscience Research Center, University Claude Bernard Lyon 1, INSERM U1028, CNRS UMR 5292, Lyon, France.
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Strobel J, Müller HP, Ludolph AC, Beer AJ, Sollmann N, Kassubek J. New Perspectives in Radiological and Radiopharmaceutical Hybrid Imaging in Progressive Supranuclear Palsy: A Systematic Review. Cells 2023; 12:2776. [PMID: 38132096 PMCID: PMC10742083 DOI: 10.3390/cells12242776] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Revised: 11/28/2023] [Accepted: 12/04/2023] [Indexed: 12/23/2023] Open
Abstract
Progressive supranuclear palsy (PSP) is a neurodegenerative disease characterized by four-repeat tau deposition in various cell types and anatomical regions, and can manifest as several clinical phenotypes, including the most common phenotype, Richardson's syndrome. The limited availability of biomarkers for PSP relates to the overlap of clinical features with other neurodegenerative disorders, but identification of a growing number of biomarkers from imaging is underway. One way to increase the reliability of imaging biomarkers is to combine different modalities for multimodal imaging. This review aimed to provide an overview of the current state of PSP hybrid imaging by combinations of positron emission tomography (PET) and magnetic resonance imaging (MRI). Specifically, combined PET and MRI studies in PSP highlight the potential of [18F]AV-1451 to detect tau, but also the challenge in differentiating PSP from other neurodegenerative diseases. Studies over the last years showed a reduced synaptic density in [11C]UCB-J PET, linked [11C]PK11195 and [18F]AV-1451 markers to disease progression, and suggested the potential role of [18F]RO948 PET for identifying tau pathology in subcortical regions. The integration of quantitative global and regional gray matter analysis by MRI may further guide the assessment of reduced cortical thickness or volume alterations, and diffusion MRI could provide insight into microstructural changes and structural connectivity in PSP. Challenges in radiopharmaceutical biomarkers and hybrid imaging require further research targeting markers for comprehensive PSP diagnosis.
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Affiliation(s)
- Joachim Strobel
- Department of Nuclear Medicine, University Hospital Ulm, 89081 Ulm, Germany;
| | - Hans-Peter Müller
- Department of Neurology, University Hospital Ulm, 89081 Ulm, Germany; (H.-P.M.); (A.C.L.); (J.K.)
| | - Albert C. Ludolph
- Department of Neurology, University Hospital Ulm, 89081 Ulm, Germany; (H.-P.M.); (A.C.L.); (J.K.)
- German Center for Neurodegenerative Diseases (DZNE), Ulm University, 89081 Ulm, Germany
| | - Ambros J. Beer
- Department of Nuclear Medicine, University Hospital Ulm, 89081 Ulm, Germany;
| | - Nico Sollmann
- Department of Diagnostic and Interventional Radiology, University Hospital Ulm, 89081 Ulm, Germany;
- Department of Diagnostic and Interventional Neuroradiology, School of Medicine, Klinikum rechts der Isar, Technical University of Munich, 81675 Munich, Germany
- TUM-Neuroimaging Center, Klinikum rechts der Isar, Technical University of Munich, 81675 Munich, Germany
| | - Jan Kassubek
- Department of Neurology, University Hospital Ulm, 89081 Ulm, Germany; (H.-P.M.); (A.C.L.); (J.K.)
- German Center for Neurodegenerative Diseases (DZNE), Ulm University, 89081 Ulm, Germany
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6
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Mostert JM, Dur NB, Li X, Ellermann JM, Hemke R, Hales L, Mazzoli V, Kogan F, Griffith JF, Oei EH, van der Heijden RA. Advanced Magnetic Resonance Imaging and Molecular Imaging of the Painful Knee. Semin Musculoskelet Radiol 2023; 27:618-631. [PMID: 37935208 PMCID: PMC10629992 DOI: 10.1055/s-0043-1775741] [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] [Indexed: 11/09/2023]
Abstract
Chronic knee pain is a common condition. Causes of knee pain include trauma, inflammation, and degeneration, but in many patients the pathophysiology remains unknown. Recent developments in advanced magnetic resonance imaging (MRI) techniques and molecular imaging facilitate more in-depth research focused on the pathophysiology of chronic musculoskeletal pain and more specifically inflammation. The forthcoming new insights can help develop better targeted treatment, and some imaging techniques may even serve as imaging biomarkers for predicting and assessing treatment response in the future. This review highlights the latest developments in perfusion MRI, diffusion MRI, and molecular imaging with positron emission tomography/MRI and their application in the painful knee. The primary focus is synovial inflammation, also known as synovitis. Bone perfusion and bone metabolism are also addressed.
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Affiliation(s)
- Jacob M. Mostert
- Department of Radiology and Nuclear Medicine, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Niels B.J. Dur
- Department of Radiology and Nuclear Medicine, Erasmus University Medical Center, Rotterdam, The Netherlands
- Department of Orthopedics and Sports Medicine, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Xiufeng Li
- Department of Radiology, Center for Magnetic Resonance Research (CMRR), University of Minnesota, Minneapolis, Minnesota
| | - Jutta M. Ellermann
- Department of Radiology, Center for Magnetic Resonance Research (CMRR), University of Minnesota, Minneapolis, Minnesota
| | - Robert Hemke
- Department of Radiology and Nuclear Medicine, Amsterdam University Medical Center, Amsterdam, The Netherlands
| | - Laurel Hales
- Department of Radiology, Stanford University, Stanford, California
| | | | - Feliks Kogan
- Department of Radiology, Stanford University, Stanford, California
| | - James F. Griffith
- Department of Imaging and Interventional Radiology Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong
| | - Edwin H.G. Oei
- Department of Radiology and Nuclear Medicine, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Rianne A. van der Heijden
- Department of Radiology and Nuclear Medicine, Erasmus University Medical Center, Rotterdam, The Netherlands
- Department of Radiology, University of Wisconsin-Madison, Madison, Wisconsin
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7
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Garland EF, Dennett O, Lau LC, Chatelet DS, Bottlaender M, Nicoll JAR, Boche D. The mitochondrial protein TSPO in Alzheimer's disease: relation to the severity of AD pathology and the neuroinflammatory environment. J Neuroinflammation 2023; 20:186. [PMID: 37580767 PMCID: PMC10424356 DOI: 10.1186/s12974-023-02869-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Accepted: 08/02/2023] [Indexed: 08/16/2023] Open
Abstract
The 18kD translocator protein (TSPO) is used as a positron emission tomography (PET) target to quantify neuroinflammation in patients. In Alzheimer's disease (AD), the cerebellum is the pseudo-reference region for comparison with the cerebral cortex due to the absence of AD pathology and lower levels of TSPO. However, using the cerebellum as a pseudo-reference region is debated, with other brain regions suggested as more suitable. This paper aimed to establish the neuroinflammatory differences between the temporal cortex and cerebellar cortex, including TSPO expression. Using 60 human post-mortem samples encompassing the spectrum of Braak stages (I-VI), immunostaining for pan-Aβ, hyperphosphorylated (p)Tau, TSPO and microglial proteins Iba1, HLA-DR and MSR-A was performed in the temporal cortex and cerebellum. In the cerebellum, Aβ but not pTau, increased over the course of the disease, in contrast to the temporal cortex, where both proteins were significantly increased. TSPO increased in the temporal cortex, more than twofold in the later stages of AD compared to the early stages, but not in the cerebellum. Conversely, Iba1 increased in the cerebellum, but not in the temporal cortex. TSPO was associated with pTau in the temporal cortex, suggesting that TSPO positive microglia may be reacting to pTau itself and/or neurodegeneration at later stages of AD. Furthermore, the neuroinflammatory microenvironment was examined, using MesoScale Discovery assays, and IL15 only was significantly increased in the temporal cortex. Together this data suggests that the cerebellum maintains a more homeostatic environment compared to the temporal cortex, with a consistent TSPO expression, supporting its use as a pseudo-reference region for quantification in TSPO PET scans.
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Affiliation(s)
- Emma F Garland
- Clinical Neurosciences, Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton General Hospital, Southampton, SO16 6YD, UK
| | - Oliver Dennett
- Clinical Neurosciences, Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton General Hospital, Southampton, SO16 6YD, UK
| | - Laurie C Lau
- Clinical Neurosciences, Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton General Hospital, Southampton, SO16 6YD, UK
| | - David S Chatelet
- Biomedical Imaging Unit, University of Southampton, Southampton General Hospital, Southampton, SO16 6YD, UK
| | - Michel Bottlaender
- CEA, CNRS, Inserm, BioMaps, Service Hospitalier Frederic Joliot, Paris-Sacaly University, 91400, Orsay, France
- UNIACT Neurospin, CEA, Gif-Sur-Yvette, 91191, France
| | - James A R Nicoll
- Clinical Neurosciences, Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton General Hospital, Southampton, SO16 6YD, UK
- Department of Cellular Pathology, University Hospital Southampton NHS Trust, Southampton, SO16 6YD, UK
| | - Delphine Boche
- Clinical Neurosciences, Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton General Hospital, Southampton, SO16 6YD, UK.
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8
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Lapo Pais M, Jorge L, Martins R, Canário N, Xavier AC, Bernardes R, Abrunhosa A, Santana I, Castelo-Branco M. Textural properties of microglial activation in Alzheimer's disease as measured by (R)-[ 11C]PK11195 PET. Brain Commun 2023; 5:fcad148. [PMID: 37229217 PMCID: PMC10205176 DOI: 10.1093/braincomms/fcad148] [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: 04/29/2022] [Revised: 02/10/2023] [Accepted: 05/04/2023] [Indexed: 05/27/2023] Open
Abstract
Alzheimer's disease is the most common form of dementia worldwide, accounting for 60-70% of diagnosed cases. According to the current understanding of molecular pathogenesis, the main hallmarks of this disease are the abnormal accumulation of amyloid plaques and neurofibrillary tangles. Therefore, biomarkers reflecting these underlying biological mechanisms are recognized as valid tools for an early diagnosis of Alzheimer's disease. Inflammatory mechanisms, such as microglial activation, are known to be involved in Alzheimer's disease onset and progression. This activated state of the microglia is associated with increased expression of the translocator protein 18 kDa. On that account, PET tracers capable of measuring this signature, such as (R)-[11C]PK11195, might be instrumental in assessing the state and evolution of Alzheimer's disease. This study aims to investigate the potential of Gray Level Co-occurrence Matrix-based textural parameters as an alternative to conventional quantification using kinetic models in (R)-[11C]PK11195 PET images. To achieve this goal, kinetic and textural parameters were computed on (R)-[11C]PK11195 PET images of 19 patients with an early diagnosis of Alzheimer's disease and 21 healthy controls and submitted separately to classification using a linear support vector machine. The classifier built using the textural parameters showed no inferior performance compared to the classical kinetic approach, yielding a slightly larger classification accuracy (accuracy of 0.7000, sensitivity of 0.6957, specificity of 0.7059 and balanced accuracy of 0.6967). In conclusion, our results support the notion that textural parameters may be an alternative to conventional quantification using kinetic models in (R)-[11C]PK11195 PET images. The proposed quantification method makes it possible to use simpler scanning procedures, which increase patient comfort and convenience. We further speculate that textural parameters may also provide an alternative to kinetic analysis in (R)-[11C]PK11195 PET neuroimaging studies involving other neurodegenerative disorders. Finally, we recognize that the potential role of this tracer is not in diagnosis but rather in the assessment and progression of the diffuse and dynamic distribution of inflammatory cell density in this disorder as a promising therapeutic target.
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Affiliation(s)
- Marta Lapo Pais
- Coimbra Institute for Biomedical Imaging and Translational Research (CIBIT), Institute for Nuclear Sciences Applied to Health (ICNAS), University of Coimbra, 3000-548 Coimbra, Portugal
| | - Lília Jorge
- Coimbra Institute for Biomedical Imaging and Translational Research (CIBIT), Institute for Nuclear Sciences Applied to Health (ICNAS), University of Coimbra, 3000-548 Coimbra, Portugal
| | - Ricardo Martins
- Coimbra Institute for Biomedical Imaging and Translational Research (CIBIT), Institute for Nuclear Sciences Applied to Health (ICNAS), University of Coimbra, 3000-548 Coimbra, Portugal
| | - Nádia Canário
- Coimbra Institute for Biomedical Imaging and Translational Research (CIBIT), Institute for Nuclear Sciences Applied to Health (ICNAS), University of Coimbra, 3000-548 Coimbra, Portugal
- Clinical Academic Centre of Coimbra (CACC), Faculty of Medicine (FMUC), University of Coimbra, 3000-548 Coimbra, Portugal
| | - Ana Carolina Xavier
- Coimbra Institute for Biomedical Imaging and Translational Research (CIBIT), Institute for Nuclear Sciences Applied to Health (ICNAS), University of Coimbra, 3000-548 Coimbra, Portugal
| | - Rui Bernardes
- Coimbra Institute for Biomedical Imaging and Translational Research (CIBIT), Institute for Nuclear Sciences Applied to Health (ICNAS), University of Coimbra, 3000-548 Coimbra, Portugal
- Clinical Academic Centre of Coimbra (CACC), Faculty of Medicine (FMUC), University of Coimbra, 3000-548 Coimbra, Portugal
| | - Antero Abrunhosa
- Coimbra Institute for Biomedical Imaging and Translational Research (CIBIT), Institute for Nuclear Sciences Applied to Health (ICNAS), University of Coimbra, 3000-548 Coimbra, Portugal
| | - Isabel Santana
- Clinical Academic Centre of Coimbra (CACC), Faculty of Medicine (FMUC), University of Coimbra, 3000-548 Coimbra, Portugal
- Department of Neurology, Coimbra University Hospital, 3000-076 Coimbra, Portugal
| | - Miguel Castelo-Branco
- Correspondence to: Dr Miguel Castelo-Branco ICNAS/CIBIT, Pólo das Ciências da Saúde da Universidade de Coimbra Azinhaga de Santa Comba, 3000-548 Coimbra, Portugal E-mail:
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9
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Park J, Wasim S, Jung JH, Kim MH, Lee BC, Alam MM, Lee SY. Synthesis, In Silico and In Vitro Characterization of Novel N, N-Substituted Pyrazolopyrimidine Acetamide Derivatives for the 18KDa Translocator Protein (TSPO). Pharmaceuticals (Basel) 2023; 16:ph16040576. [PMID: 37111333 PMCID: PMC10142799 DOI: 10.3390/ph16040576] [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: 02/08/2023] [Revised: 04/01/2023] [Accepted: 04/06/2023] [Indexed: 04/29/2023] Open
Abstract
The translocator protein (TSPO) is an interesting biological target for molecular imaging and therapy because the overexpression of TSPO is associated with microglial activation caused by neuronal damage or neuroinflammation, and these activated microglia are involved in various central nervous system (CNS) diseases. The TSPO is a target for neuroprotective treatment, which is used with the aim of reducing microglial cell activation. The novel N,N-disubstituted pyrazolopyrimidine acetamides scaffold (GMA 7-17), which bears a fluorine atom and is directly linked to the phenyl moiety, was synthesized, and each of the novel ligands was characterized in vitro. All of the newly synthesized ligands displayed picomolar to nanomolar affinity for the TSPO. Particularly, an in vitro affinity study led to the discovery of 2-(5,7-diethyl-2-(4-fluorophenyl)pyrazolo [1,5-a]pyrimidin-3-yl)-N-ethyl-N-phenylacetamide GMA 15 (Ki = 60 pM), a novel TSPO ligand that exhibits a 61-fold enhancement in affinity compared to the reference standard DPA-714 (Ki = 3.66 nM). Molecular dynamic (MD) studies of the highest affinity binder, GMA 15, were carried out to check its time-dependent stability with the receptor compared to DPA-714 and PK11195. The hydrogen bond plot also indicated that GMA 15 formed higher hydrogen bonds compared to DPA-714 and PK11195. We anticipate that further optimization to enhance the potency in a cellular assay needs to be followed, but our strategy of identifying potential TSPO binding novel scaffolds may open up a new avenue to develop novel TSPO ligands suited for potential molecular imaging and a wide range of therapeutic applications.
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Affiliation(s)
- Jaekyung Park
- Gachon Advanced Institute for Health Science and Technology, Graduate School, Gachon University, Incheon 21999, Republic of Korea
| | - Sobia Wasim
- Department of Biochemistry, College of Medicine, Gachon University, Incheon 21999, Republic of Korea
| | - Jae Ho Jung
- Department of Nuclear Medicine, Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seongnam 13620, Republic of Korea
| | - Mi-Hyun Kim
- Gachon Institute of Pharmaceutical Science and Department of Pharmacy, College of Pharmacy, Gachon University, Incheon 21936, Republic of Korea
| | - Byung Chul Lee
- Department of Nuclear Medicine, Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seongnam 13620, Republic of Korea
- Center for Nanomolecular Imaging and Innovative Drug Development, Advanced Institutes of Convergence Technology, Suwon 16229, Republic of Korea
| | | | - Sang-Yoon Lee
- Gachon Advanced Institute for Health Science and Technology, Graduate School, Gachon University, Incheon 21999, Republic of Korea
- Neuroscience Research Institute, Gachon University, Incheon 20565, Republic of Korea
- Department of Neuroscience, College of Medicine, Gachon University, Incheon 21936, Republic of Korea
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10
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Lehto J, Sucksdorff M, Nylund M, Raitanen R, Matilainen M, Airas L. PET-measurable innate immune cell activation reduction in chronic active lesions in PPMS brain after rituximab treatment: a case report. J Neurol 2023; 270:2329-2332. [PMID: 36576574 DOI: 10.1007/s00415-022-11539-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 12/15/2022] [Accepted: 12/16/2022] [Indexed: 12/29/2022]
Abstract
OBJECTIVES To evaluate the effects of rituximab treatment on innate immune cell activation in primary progressive multiple sclerosis (PPMS). METHODS A 48-year-old woman with PPMS was started on rituximab shortly after diagnosis. [11C]PK11195 PET imaging was employed to assess innate immune cell activation with special interest in the white matter around chronic lesions. PET, MRI, and disability measurements were performed at baseline and after 18 months of rituximab treatment. Specific binding of [11C]PK11195 was quantified using mean distribution volume ratios (DVRs), and at voxel-level based on proportions of active voxels. RESULTS The PPMS patient had higher PK11195 DVRs and higher proportions of active voxels in the thalamus and the normal appearing white matter compared to the healthy control group. The thalamic and perilesional white matter DVRs and the proportions of active voxels decreased after rituximab treatment. The patient remained clinically stable during the 5-years follow-up. CONCLUSIONS This case suggests that while a degree of smoldering activity persists, high efficacy B-cell-targeting therapy may contribute to reduced innate immune cell activation in PPMS brain areas relevant for disease progression. This case supports the therapeutic concept that controlling smoldering brain inflammation is beneficial for slowing down progression independent of relapses.
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Affiliation(s)
- Jussi Lehto
- Turku PET Centre, Turku University Hospital, Po Box 52, 20521, Turku, Finland.
- Neurocenter, Turku University Hospital, Turku, Finland.
| | - Marcus Sucksdorff
- Turku PET Centre, Turku University Hospital, Po Box 52, 20521, Turku, Finland
- Clinical Neurosciences, University of Turku, Turku, Finland
- Neurocenter, Turku University Hospital, Turku, Finland
| | - Marjo Nylund
- Turku PET Centre, Turku University Hospital, Po Box 52, 20521, Turku, Finland
- Clinical Neurosciences, University of Turku, Turku, Finland
| | - Roope Raitanen
- Turku PET Centre, Turku University Hospital, Po Box 52, 20521, Turku, Finland
- Clinical Neurosciences, University of Turku, Turku, Finland
| | - Markus Matilainen
- Turku PET Centre, Turku University Hospital, Po Box 52, 20521, Turku, Finland
- Faculty of Science and Engineering, Åbo Akademi University, Turku, Finland
| | - Laura Airas
- Clinical Neurosciences, University of Turku, Turku, Finland
- Neurocenter, Turku University Hospital, Turku, Finland
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11
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Becker G, Debatisse J, Rivière M, Crola Da Silva C, Beaudoin-Gobert M, Eker O, Wateau O, Cho TH, Wiart M, Tremblay L, Costes N, Mérida I, Redouté J, Léon C, Langlois JB, Le Bars D, Lancelot S, Nighoghossian N, Mechtouff L, Canet-Soulas E. Spatio-Temporal Characterization of Brain Inflammation in a Non-human Primate Stroke Model Mimicking Endovascular Thrombectomy. Neurotherapeutics 2023; 20:789-802. [PMID: 36976495 PMCID: PMC10275847 DOI: 10.1007/s13311-023-01368-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/13/2023] [Indexed: 03/29/2023] Open
Abstract
Reperfusion therapies in acute ischemic stroke have demonstrated their efficacy in promoting clinical recovery. However, ischemia/reperfusion injury and related inflammation remain a major challenge in patient clinical management. We evaluated the spatio-temporal evolution of inflammation using sequential clinical [11C]PK11195 PET-MRI in a non-human primate (NHP) stroke model mimicking endovascular thrombectomy (EVT) with a neuroprotective cyclosporine A (CsA) treatment. The NHP underwent a 110-min transient endovascular middle cerebral artery occlusion. We acquired [11C]PK11195 dynamic PET-MR imaging at baseline, 7 and 30 days after intervention. Individual voxel-wise analysis was performed thanks to a baseline scan database. We quantified [11C]PK11195 in anatomical regions and in lesioned areas defined on per-occlusion MR diffusion-weighted imaging and perfusion [15O2]H2OPET imaging. [11C]PK11195 parametric maps showed a clear uptake overlapping the lesion core at D7, which further increased at D30. Voxel-wise analysis identified individuals with significant inflammation at D30, with voxels located within the most severe diffusion reduction area during occlusion, mainly in the putamen. The quantitative analysis revealed that thalamic inflammation lasted until D30 and was significantly reduced in the CsA-treated group compared to the placebo. In conclusion, we showed that chronic inflammation matched ADC decrease at occlusion time, a region exposed to an initial burst of damage-associated molecular patterns, in an NHP stroke model mimicking EVT. We described secondary thalamic inflammation and the protective effect of CsA in this region. We propose that major ADC drop in the putamen during occlusion may identify individuals who could benefit from early personalized treatment targeting inflammation.
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Affiliation(s)
- Guillaume Becker
- CarMeN Laboratory, INRAE U1397, INSERM U1060, Groupement Hospitalier Est, University Claude Bernard Lyon 1, 59 Boulevard Pinel, 69500, Lyon, Bron, France.
| | - Justine Debatisse
- CarMeN Laboratory, INRAE U1397, INSERM U1060, Groupement Hospitalier Est, University Claude Bernard Lyon 1, 59 Boulevard Pinel, 69500, Lyon, Bron, France
| | - Margaux Rivière
- CarMeN Laboratory, INRAE U1397, INSERM U1060, Groupement Hospitalier Est, University Claude Bernard Lyon 1, 59 Boulevard Pinel, 69500, Lyon, Bron, France
| | - Claire Crola Da Silva
- CarMeN Laboratory, INRAE U1397, INSERM U1060, Groupement Hospitalier Est, University Claude Bernard Lyon 1, 59 Boulevard Pinel, 69500, Lyon, Bron, France
| | - Maude Beaudoin-Gobert
- Lyon Neuroscience Research Center, UMR5295, INSERM U1028, CNRS, Université Claude Bernard Lyon 1, Lyon, France
| | - Omer Eker
- UMR-5220, CREATIS, CNRS, INSERM U1206, Université Lyon 1, INSA Lyon, Villeurbanne, France
- , Hospices Civils de Lyon, Lyon, France
| | | | - Tae Hee Cho
- CarMeN Laboratory, INRAE U1397, INSERM U1060, Groupement Hospitalier Est, University Claude Bernard Lyon 1, 59 Boulevard Pinel, 69500, Lyon, Bron, France
- , Hospices Civils de Lyon, Lyon, France
| | - Marlène Wiart
- CarMeN Laboratory, INRAE U1397, INSERM U1060, Groupement Hospitalier Est, University Claude Bernard Lyon 1, 59 Boulevard Pinel, 69500, Lyon, Bron, France
| | - Léon Tremblay
- Cognitive Neuroscience Center, CNRS UMR5229, Université Claude Bernard Lyon 1, Lyon, France
| | | | | | | | - Christelle Léon
- CarMeN Laboratory, INRAE U1397, INSERM U1060, Groupement Hospitalier Est, University Claude Bernard Lyon 1, 59 Boulevard Pinel, 69500, Lyon, Bron, France
| | | | - Didier Le Bars
- , Hospices Civils de Lyon, Lyon, France
- CERMEP, Lyon, France
| | | | - Norbert Nighoghossian
- CarMeN Laboratory, INRAE U1397, INSERM U1060, Groupement Hospitalier Est, University Claude Bernard Lyon 1, 59 Boulevard Pinel, 69500, Lyon, Bron, France
- , Hospices Civils de Lyon, Lyon, France
| | - Laura Mechtouff
- CarMeN Laboratory, INRAE U1397, INSERM U1060, Groupement Hospitalier Est, University Claude Bernard Lyon 1, 59 Boulevard Pinel, 69500, Lyon, Bron, France
- , Hospices Civils de Lyon, Lyon, France
| | - Emmanuelle Canet-Soulas
- CarMeN Laboratory, INRAE U1397, INSERM U1060, Groupement Hospitalier Est, University Claude Bernard Lyon 1, 59 Boulevard Pinel, 69500, Lyon, Bron, France
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12
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Tan Z, Haider A, Zhang S, Chen J, Wei J, Liao K, Li G, Wei H, Dong C, Ran W, Li Y, Li Y, Rong J, Li Y, Liang SH, Xu H, Wang L. Quantitative assessment of translocator protein (TSPO) in the non-human primate brain and clinical translation of [ 18F]LW223 as a TSPO-targeted PET radioligand. Pharmacol Res 2023; 189:106681. [PMID: 36746361 DOI: 10.1016/j.phrs.2023.106681] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Revised: 01/12/2023] [Accepted: 01/30/2023] [Indexed: 02/05/2023]
Abstract
OBJECTIVES Translocator protein 18 kDa (TSPO) positron emission tomography (PET) can be harnessed for the non-invasive detection of macrophage-driven inflammation. [18F]LW223, a newly reported TSPO PET tracer which was insensitive to rs6971 polymorphism, showed favorable performance characteristics in a recent imaging study involving a rat myocardial infarction model. To enable quantitative neuroimaging with [18F]LW223, we conducted kinetic analysis in the non-human primate (NHP) brain. Further, we sought to assess the utility of [18F]LW223-based TSPO imaging in a first-in-human study. METHODS Radiosynthesis of [18F]LW223 was accomplished on an automated module, whereas molar activities, stability in formulation, lipophilicity and unbound free fraction (fu) of the probe were measured. Brain penetration and target specificity of [18F]LW223 in NHPs were corroborated by PET-MR imaging under baseline and pre-blocking conditions using the validated TSPO inhibitor, (R)-PK11195, at doses ranging from 5 to 10 mg/kg. Kinetic modeling was performed using one-tissue compartment model (1TCM), two-tissue compartment model (2TCM) and Logan graphical analyses, using dynamic PET data acquisition, arterial blood collection and metabolic stability testing. Clinical PET scans were performed in two healthy volunteers (HVs). Regional brain standard uptake value ratio (SUVr) was assessed for different time intervals. RESULTS [18F]LW223 was synthesized in non-decay corrected radiochemical yields (n.d.c. RCYs) of 33.3 ± 6.5% with molar activities ranging from 1.8 ± 0.7 Ci/µmol (n = 11). [18F]LW223 was stable in formulation for up to 4 h and LogD7.4 of 2.31 ± 0.13 (n = 6) and fu of 5.80 ± 1.42% (n = 6) were determined. [18F]LW223 exhibited good brain penetration in NHPs, with a peak SUV value of ca. 1.79 in the whole brain. Pre-treatment with (R)-PK11195 substantially accelerated the washout and attenuated the area under the time-activity curve, indicating in vivo specificity of [18F]LW223 towards TSPO. Kinetic modeling demonstrated that 2TCM was the most suitable model for [18F]LW223-based neuroimaging. Global transfer rate constants (K1) and total volumes of distribution (VT) were found to be 0.10 ± 0.01 mL/cm3/min and 2.30 ± 0.17 mL/cm3, respectively. Dynamic PET data analyses across distinct time windows revealed that the VT values were relatively stable after 60 min post-injection. In a preliminary clinical study with two healthy volunteers, [18F]LW223 exhibited good brain uptake and considerable tracer retention across all analyzed brain regions. Of note, an excellent correlation between SUVr with VT was obtained when assessing the time interval from 20 to 40 min post tracer injection (SUVr(20-40 min), R2 = 0.94, p < 0.0001), suggesting this time window may be suitable to estimate specific binding to TSPO in human brain. CONCLUSION Our findings indicate that [18F]LW223 is suitable for quantitative TSPO-targeted PET imaging in higher species. Employing state-of-the-art kinetic modeling, we found that [18F]LW223 was effective in mapping TSPO throughout the NHP brain, with best model fits obtained from 2TCM and Logan graphical analyses. Overall, our results indicate that [18F]LW223 exhibits favorable tracer performance characteristics in higher species, and this novel imaging tool may hold promise to provide effective neuroinflammation imaging in patients with neurological disease.
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Affiliation(s)
- Zhiqiang Tan
- Center of Cyclotron and PET Radiopharmaceuticals, Department of Nuclear Medicine and PET/CT-MRI Center, The First Affiliated Hospital of Jinan University, Guangzhou 510630, China
| | - Ahmed Haider
- Department of Radiology and Imaging Sciences, Emory University, 1364 Clifton Rd, Atlanta, GA 30322, USA
| | - Shaojuan Zhang
- Center of Cyclotron and PET Radiopharmaceuticals, Department of Nuclear Medicine and PET/CT-MRI Center, The First Affiliated Hospital of Jinan University, Guangzhou 510630, China
| | - Jiahui Chen
- Department of Radiology and Imaging Sciences, Emory University, 1364 Clifton Rd, Atlanta, GA 30322, USA
| | - Junjie Wei
- Center of Cyclotron and PET Radiopharmaceuticals, Department of Nuclear Medicine and PET/CT-MRI Center, The First Affiliated Hospital of Jinan University, Guangzhou 510630, China
| | - Kai Liao
- Center of Cyclotron and PET Radiopharmaceuticals, Department of Nuclear Medicine and PET/CT-MRI Center, The First Affiliated Hospital of Jinan University, Guangzhou 510630, China
| | - Guocong Li
- Center of Cyclotron and PET Radiopharmaceuticals, Department of Nuclear Medicine and PET/CT-MRI Center, The First Affiliated Hospital of Jinan University, Guangzhou 510630, China
| | - Huiyi Wei
- Center of Cyclotron and PET Radiopharmaceuticals, Department of Nuclear Medicine and PET/CT-MRI Center, The First Affiliated Hospital of Jinan University, Guangzhou 510630, China
| | - Chenchen Dong
- Center of Cyclotron and PET Radiopharmaceuticals, Department of Nuclear Medicine and PET/CT-MRI Center, The First Affiliated Hospital of Jinan University, Guangzhou 510630, China
| | - Wenqing Ran
- Center of Cyclotron and PET Radiopharmaceuticals, Department of Nuclear Medicine and PET/CT-MRI Center, The First Affiliated Hospital of Jinan University, Guangzhou 510630, China
| | - Ying Li
- Center of Cyclotron and PET Radiopharmaceuticals, Department of Nuclear Medicine and PET/CT-MRI Center, The First Affiliated Hospital of Jinan University, Guangzhou 510630, China
| | - Yuefeng Li
- Guangdong Landau Biotechnology Co. Ltd., Guangzhou 510555, China
| | - Jian Rong
- Department of Radiology and Imaging Sciences, Emory University, 1364 Clifton Rd, Atlanta, GA 30322, USA
| | - Yinlong Li
- Department of Radiology and Imaging Sciences, Emory University, 1364 Clifton Rd, Atlanta, GA 30322, USA
| | - Steven H Liang
- Department of Radiology and Imaging Sciences, Emory University, 1364 Clifton Rd, Atlanta, GA 30322, USA.
| | - Hao Xu
- Center of Cyclotron and PET Radiopharmaceuticals, Department of Nuclear Medicine and PET/CT-MRI Center, The First Affiliated Hospital of Jinan University, Guangzhou 510630, China.
| | - Lu Wang
- Center of Cyclotron and PET Radiopharmaceuticals, Department of Nuclear Medicine and PET/CT-MRI Center, The First Affiliated Hospital of Jinan University, Guangzhou 510630, China.
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13
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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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14
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Evaluation of (R)-[ 11C]PK11195 PET/MRI for Spinal Cord-Related Neuropathic Pain in Patients with Cervical Spinal Disorders. J Clin Med 2022; 12:jcm12010116. [PMID: 36614916 PMCID: PMC9821277 DOI: 10.3390/jcm12010116] [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: 11/25/2022] [Revised: 12/19/2022] [Accepted: 12/21/2022] [Indexed: 12/28/2022] Open
Abstract
Activated microglia are involved in secondary injury after acute spinal cord injury (SCI) and in development of spinal cord-related neuropathic pain (NeP). The aim of the study was to assess expression of translocator protein 18 kDa (TSPO) as an indicator of microglial activation and to investigate visualization of the dynamics of activated microglia in the injured spinal cord using PET imaging with (R)-[11C]PK11195, a specific ligand for TSPO. In SCI chimeric animal models, TSPO was expressed mainly in activated microglia. Accumulation of (R)-[3H]PK11195 was confirmed in autoradiography and its dynamics in the injured spinal cord were visualized by (R)-[11C]PK11195 PET imaging in the acute phase after SCI. In clinical application of (R)-[11C]PK11195 PET/MRI of the cervical spinal cord in patients with NeP related to cervical disorders, uptake was found in cases up to 10 months after injury or surgery. No uptake could be visualized in the injured spinal cord in patients with chronic NeP at more than 1 year after injury or surgery, regardless of the degree of NeP. However, a positive correlation was found between standardized uptake value ratio and the severity of NeP, suggesting the potential of clinical application for objective evaluation of chronic NeP.
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15
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Meier SR, Sehlin D, Syvänen S. Passive and receptor mediated brain delivery of an anti-GFAP nanobody. Nucl Med Biol 2022; 114-115:121-127. [PMID: 35487832 DOI: 10.1016/j.nucmedbio.2022.04.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 03/24/2022] [Accepted: 04/04/2022] [Indexed: 12/27/2022]
Abstract
PURPOSE Antibody-based constructs, engineered to enter the brain using transferrin receptor (TfR) mediated transcytosis, have been successfully used as PET radioligands for imaging of amyloid-beta (Aβ) in preclinical studies. However, these radioligands have been large and associated with long circulation times, i.e. non-optimal properties for neuroPET radioligands. The aim of this study was to investigate the in vivo brain delivery of the radiolabeled nanobody VHH-E9 that binds to glial fibrillary acidic protein (GFAP) expressed by reactive astrocytes, without and with fusion to a TfR binding moiety, as potential tools to detect neuroinflammation. METHODS Three protein constructs were recombinantly expressed: 1) The GFAP specific nanobody VHH-E9, 2) VHH-E9 fused to a single chain variable fragment of the TfR binding antibody 8D3 (scFv8D3) and 3) scFv8D3 alone. Brain delivery of the constructs was investigated at 2 h post injection. Binding to GFAP was studied with autoradiography while in vivo brain retention of [125I]VHH-E9 and [125I]VHH-E9-scFv8D3 was further investigated at 8 h, 24 h and 48 h in wild-type (WT), and at the same time points in transgenic mice (ArcSwe) that in addition to Aβ pathology also display neuroinflammation. RESULTS At 2 h after administration, [125I]VHH-E9-scFv8D3 and [125I]scFv8D3 displayed 3-fold higher brain concentrations than [125I]VHH-E9. In vitro autoradiography showed distinct binding of both [125I]VHH-E9-scFv8D3 and [125I]VHH-E9 to regions with abundant GFAP in ArcSwe mice. However, in vivo, there was no difference in brain concentrations between WT and ArcSwe at any of the studied time points. CONCLUSIONS Fused to scFv8D3, VHH-E9 displayed increased brain delivery. When radiolabeled and applied on brain sections, the bispecific construct was able to discriminate between WT and ArcSwe mice, but in vivo brain uptake and retention over time did not differ between WT and ArcSwe mice.
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Affiliation(s)
- Silvio R Meier
- Department of Public Health and Caring Sciences, Uppsala University, Uppsala, Sweden
| | - Dag Sehlin
- Department of Public Health and Caring Sciences, Uppsala University, Uppsala, Sweden
| | - Stina Syvänen
- Department of Public Health and Caring Sciences, Uppsala University, Uppsala, Sweden.
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16
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Wongso H. Recent progress on the development of fluorescent probes targeting the translocator protein 18 kDa (TSPO). Anal Biochem 2022; 655:114854. [PMID: 35963341 DOI: 10.1016/j.ab.2022.114854] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Accepted: 08/06/2022] [Indexed: 11/01/2022]
Abstract
The translocator protein 18 kDa (TSPO) was first identified in 1997, and has now become one of the appealing subcellular targets in medicinal chemistry and its related fields. TSPO involves in a variety of diseases, covering neurodegenerative diseases, psychiatric disorders, cancers, and so on. To date, various high-affinity TSPO ligands labelled with single-photon emission computed tomography (SPECT)/positron emission tomography (PET) radionuclides have been reported, with some third-generation radioligands advanced to clinical trials. On the other hand, only a few number of TSPO ligands have been labelled with fluorophores for disease diagnosis. It is noteworthy that the majority of the TSPO fluorescent probes synthesised to date are based on visible fluorophores, suggesting that their applications are limited to in vitro studies, such as in vitro imaging of cancer cells, post-mortem analysis, and tissue biopsies examinations. In this context, the potential application of TSPO ligands can be broadened for in vivo investigations of human diseases by labelling with near-infrared (NIR)-fluorophores or substituting visible fluorophores with NIR-fluorophores on the currently developed fluorescent probes. In this review article, recent progress on fluorescent probes targeting the TSPO are summarised, with an emphasis on development trend in recent years and application prospects in the future.
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Affiliation(s)
- Hendris Wongso
- Research Center for Radioisotope, Radiopharmaceutical, and Biodosimetry Technology, Research Organization for Nuclear Energy, National Research and Innovation Agency, Puspiptek, Banten, 15314, Indonesia.
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17
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Xue X, Duan R, Zheng G, Chen H, Zhang W, Shi L. Translocator protein (18 kDa) regulates the microglial phenotype in Parkinson's disease through P47. Bioengineered 2022; 13:11061-11071. [PMID: 35475466 PMCID: PMC9208449 DOI: 10.1080/21655979.2022.2068754] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022] Open
Abstract
Numerous studies have suggested that the phenotypic transformation of microglia plays a role in the pathogenesis of Parkinson's disease (PD). Translocator protein (TSPO) is an 18 kDa translocator membrane protein that acts as a marker of neuroinflammation and suppresses neuroinflammation; however, its underlying mechanism remains unclear. Although TSPO ligands were found to be protective in several neurodegenerative paradigms, few studies have evaluated their effects on microglial polarization, and underlying mechanisms need to be explored. In the present study, we examined the effects of TSPO and PK11195, a TSPO ligand, on lipopolysaccharide (LPS)+interferon (IFN)-γ-induced inflammatory factors and oxidative stress in microglia using enzyme-linked immunosorbent assay. The effect of TSPO and PK11195 on LPS+IFN-γ-induced microglial cell apoptosis was examined using immunofluorescence (IF), flow cytometry, and western blotting. The interaction between TSPO and P47 was investigated using IF and co-immunoprecipitation analysis. In vivo experiments confirmed the influence of TSPO and its ligand on motility, a-Syn, and dopaminergic neuronal damage. Our findings indicate that TSPO may regulate the microglial phenotype in PD via P47, suggesting a potential role in anti-PD therapy.
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Affiliation(s)
- Xue Xue
- Department of Nuclear Medicine, Nanjing First Hospital, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Rui Duan
- Department of Neurology, Nanjing First Hospital, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Guoyan Zheng
- Department of Nuclear Medicine, Nanjing First Hospital, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Hucheng Chen
- Department of Nuclear Medicine, Nanjing First Hospital, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Weiwei Zhang
- Department of Pathogenic Biology, Nanjing University of Chinese Medicine, Nanjing, Jiangsu, China
| | - Liang Shi
- Department of Nuclear Medicine, Nanjing First Hospital, Nanjing Medical University, Nanjing, Jiangsu, China
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18
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Young JW, Barback CV, Stolz LA, Groman SM, Vera DR, Hoh C, Kotta KK, Minassian A, Powell SB, Brody AL. MicroPET evidence for a hypersensitive neuroinflammatory profile of gp120 mouse model of HIV. Psychiatry Res Neuroimaging 2022; 321:111445. [PMID: 35101828 DOI: 10.1016/j.pscychresns.2022.111445] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Revised: 01/19/2022] [Accepted: 01/24/2022] [Indexed: 02/07/2023]
Abstract
Despite increased survivability for people living with HIV (PLWH), HIV-related cognitive deficits persist. Determining biological mechanism(s) underlying abnormalities is critical to minimize the long-term impact of HIV. Positron emission tomography (PET) studies reveal that PLWH exhibit elevated neuroinflammation, potentially contributing to these problems. PLWH are hypersensitive to environmental insults that drive elevated inflammatory profiles. Gp120 is an envelope glycoprotein exposed on the surface of the HIV envelope which enables HIV entry into a cell contributing to HIV-related neurotoxicity. In vivo evidence for mice overexpressing gp120 (transgenic) mice exhibiting neuroinflammation remains unclear. Here, we conducted microPET imaging in gp120 transgenic and wildtype mice, using the radiotracer [(18)F]FEPPA (binds to the translocator protein expressed by activated microglial serving as a neuroinflammatory marker). Imaging was performed at baseline and 24 h after lipopolysaccharide (LPS; 5 mg/kg) treatment (endotoxin that triggers an immune response). Gp120 transgenic mice exhibited elevated [(18F)]FEPPA in response to LPS vs. wildtype mice throughout the brain including dorsal and ventral striata, hypothalamus, and hippocampus. Gp120 transgenic mice are hypersensitive to environmental inflammatory insults, consistent with PLWH, measurable in vivo. It remains to-be-determined whether this heightened sensitivity is connected to the behavioral abnormalities of these mice or sensitive to any treatments.
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Affiliation(s)
- Jared W Young
- Department of Psychiatry, University of California San Diego, 9500 Gilman Drive MC 0804, La Jolla, CA 92093-0804, USA; Research Service, VA San Diego Healthcare System, San Diego, CA, USA.
| | - Christopher V Barback
- Department of Radiology, University of California, San Diego, La Jolla California; UCSD In Vivo Cancer and Molecular Imaging Program
| | - Louise A Stolz
- Department of Psychiatry, University of California San Diego, 9500 Gilman Drive MC 0804, La Jolla, CA 92093-0804, USA
| | - Stephanie M Groman
- Department of Neuroscience, Medical Discovery Team on Addiction, University of Minnesota
| | - David R Vera
- Department of Radiology, University of California, San Diego, La Jolla California; UCSD In Vivo Cancer and Molecular Imaging Program
| | - Carl Hoh
- Department of Radiology, University of California, San Diego, La Jolla California; UCSD In Vivo Cancer and Molecular Imaging Program
| | - Kishore K Kotta
- Department of Radiology, University of California, San Diego, La Jolla California; UCSD In Vivo Cancer and Molecular Imaging Program
| | - Arpi Minassian
- Department of Psychiatry, University of California San Diego, 9500 Gilman Drive MC 0804, La Jolla, CA 92093-0804, USA; Research Service, VA San Diego Healthcare System, San Diego, CA, USA
| | - Susan B Powell
- Department of Psychiatry, University of California San Diego, 9500 Gilman Drive MC 0804, La Jolla, CA 92093-0804, USA; Research Service, VA San Diego Healthcare System, San Diego, CA, USA
| | - Arthur L Brody
- Department of Psychiatry, University of California San Diego, 9500 Gilman Drive MC 0804, La Jolla, CA 92093-0804, USA; Research Service, VA San Diego Healthcare System, San Diego, CA, USA
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Non-invasive quantification of acute macrophagic lung inflammation with [ 11C](R)-PK11195 using a three-tissue compartment kinetic model in experimental acute respiratory distress syndrome. Eur J Nucl Med Mol Imaging 2022; 49:2122-2136. [PMID: 35129652 DOI: 10.1007/s00259-022-05713-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Accepted: 01/30/2022] [Indexed: 12/18/2022]
Abstract
PURPOSE Imaging of acute lung inflammation is pivotal to evaluate innovative ventilation strategies. We aimed to develop and validate a three-tissue compartment kinetic model (3TCM) of [11C](R)-PK11195 lung uptake in experimental acute respiratory distress syndrome (ARDS) to help quantify macrophagic inflammation, while accounting for the impact of its non-specific and irreversible uptake in lung tissues. MATERIAL AND METHODS We analyzed the data of 38 positron emission tomography (PET) studies performed in 21 swine with or without experimental ARDS, receiving general anesthesia and mechanical ventilation. Model input function was a plasma, metabolite-corrected, image-derived input function measured in the main pulmonary artery. Regional lung analysis consisted in applying both the 3TCM and the two-tissue compartment model (2TCM); in each region, the best model was selected using a selection algorithm with a goodness-of-fit criterion. Regional best model binding potentials (BPND) were compared to lung macrophage presence, semi-quantified in pathology. RESULTS The 3TCM was preferred in 142 lung regions (62%, 95% confidence interval: 56 to 69%). BPND determined by the 2TCM was significantly higher than the value computed with the 3TCM (overall median with interquartile range: 0.81 [0.44-1.33] vs. 0.60 [0.34-0.94], p < 0.02). Regional macrophage score was significantly associated with the best model BPND (p = 0.03). Regional BPND was significantly increased in the hyperinflated lung compartment, compared to the normally aerated one (median with interquartile range: 0.8 [0.6-1.7] vs. 0.6 [0.3-0.8], p = 0.03). CONCLUSION To assess the intensity and spatial distribution of acute macrophagic lung inflammation in the context of experimental ARDS with mechanical ventilation, PET quantification of [11C](R)-PK11195 lung uptake was significantly improved in most lung regions using the 3TCM. This new methodology offers the opportunity to non-invasively evaluate innovative ventilatory strategies aiming at controlling acute lung inflammation.
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Kumari N, Kaul A, Deepika, Srivastava K, Mishra G, Bhagat S, Singh VK, KumarTiwari A. [99mTc-BBPA]: A possible SPECT agent to understand role of 18-kDa translocator protein (PBR/TSPO) during neuro-glial interaction. Bioorg Chem 2022; 121:105678. [DOI: 10.1016/j.bioorg.2022.105678] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Revised: 11/11/2021] [Accepted: 02/08/2022] [Indexed: 11/02/2022]
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Wimberley C, Buvat I, Boutin H. Imaging translocator protein expression with positron emission tomography. Eur J Nucl Med Mol Imaging 2021; 49:74-76. [PMID: 34729627 DOI: 10.1007/s00259-021-05601-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Catriona Wimberley
- Edinburgh Imaging QMRI, BioQuarter, University of Edinburgh, Edinburgh, EH16 4SB, UK.,Centre for Clinical Brain Sciences, Chancellor's Building, BioQuarter, University of Edinburgh, Edinburgh, EH14 4SB, UK
| | - Irene Buvat
- Institut Curie, Université PSL, Inserm, U1288 LITO, Orsay, France
| | - Hervé Boutin
- Division of Neuroscience and Experimental Psychology, School of Biological Sciences, Faculty of Brain and Mental Health, University of Manchester, Manchester, M13 9PL, UK. .,Wolfson Molecular Imaging Centre, University of Manchester, Manchester, M20 3LJ, UK. .,Geoffrey Jefferson Brain Research Centre, Manchester Academic Health Science Centre, Northern Care Alliance & University of Manchester, Manchester, UK.
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