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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Lee N, Choi JY, Ryu YH. The development status of PET radiotracers for evaluating neuroinflammation. Nucl Med Mol Imaging 2024; 58:160-176. [PMID: 38932754 PMCID: PMC11196502 DOI: 10.1007/s13139-023-00831-4] [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: 10/11/2023] [Revised: 11/16/2023] [Accepted: 12/05/2023] [Indexed: 06/28/2024] Open
Abstract
Neuroinflammation is associated with the pathophysiologies of neurodegenerative and psychiatric disorders. Evaluating neuroinflammation using positron emission tomography (PET) plays an important role in the early diagnosis and determination of proper treatment of brain diseases. To quantify neuroinflammatory responses in vivo, many PET tracers have been developed using translocator proteins, imidazole-2 binding site, cyclooxygenase, monoamine oxidase-B, adenosine, cannabinoid, purinergic P2X7, and CSF-1 receptors as biomarkers. In this review, we introduce the latest developments in PET tracers that can image neuroinflammation, focusing on clinical trials, and further consider their current implications.
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Affiliation(s)
- Namhun Lee
- Division of Applied RI, Korea Institute of Radiological & Medical Sciences, 75 Nowon-ro, Nowon-gu, Seoul, 01812 Korea
| | - Jae Yong Choi
- Division of Applied RI, Korea Institute of Radiological & Medical Sciences, 75 Nowon-ro, Nowon-gu, Seoul, 01812 Korea
- Radiological and Medico-Oncological Sciences, University of Science and Technology (UST), Seoul, Korea
| | - Young Hoon Ryu
- Department of Nuclear Medicine, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
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3
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Garrett TR, Gilchrist J, McKenzie ADJ, Larik FA, Danon JJ, Werry EL, Kassiou M. An Investigation on Linker Modifications of Cyanoguanidine-Based P2X7 Receptor Antagonists. ChemMedChem 2024:e202400163. [PMID: 38782733 DOI: 10.1002/cmdc.202400163] [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: 02/29/2024] [Revised: 05/23/2024] [Accepted: 05/23/2024] [Indexed: 05/25/2024]
Abstract
Despite their acknowledged significance in the inflammatory signalling cascade across a range of disease states, P2X7R antagonists have not yet proven to be effective in clinical trials. In this study, we present findings on P2X7 receptor antagonists that are based on a core adamantyl-cyanoguanidine-quinoline lead. To investigate the specific features of the cyanoguanidine moiety that influence compound potency we carried out a structure-activity relationship (SAR) study. Compound potency was assessed using an in vitro dye-uptake assay measuring P2X7R pore formation. While none of the compounds displayed superior potency to the lead, we established key structural requirements for potent P2X7R antagonism. An additional SAR using different aryl groups was performed based on the promising activity displayed by the squaramide derivative.
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Affiliation(s)
- Taylor R Garrett
- School of Chemistry, The University of Sydney, Sydney, NSW 2006, Australia
| | - Jayson Gilchrist
- School of Chemistry, The University of Sydney, Sydney, NSW 2006, Australia
| | - Andre D J McKenzie
- School of Chemistry, The University of Sydney, Sydney, NSW 2006, Australia
| | - Fayaz Ali Larik
- School of Chemistry, The University of Sydney, Sydney, NSW 2006, Australia
| | - Jonathan J Danon
- School of Chemistry, The University of Sydney, Sydney, NSW 2006, Australia
| | - Eryn L Werry
- School of Chemistry, The University of Sydney, Sydney, NSW 2006, Australia
- Central Clinical School, Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales, 2006, Australia
| | - Michael Kassiou
- School of Chemistry, The University of Sydney, Sydney, NSW 2006, Australia
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4
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Placzek M, Wilton DK, Weïwer M, Manter MA, Reid SE, Meyer CJ, Campbell AJ, Bajrami B, Bigot A, Bricault S, Fayet A, Frouin A, Gergits F, Gupta M, Jiang W, Melanson M, Romano CD, Riley MM, Wang JM, Wey HY, Wagner FF, Stevens B, Hooker JM. A Fast-Binding, Functionally Reversible, COX-2 Radiotracer for CNS PET Imaging. ACS CENTRAL SCIENCE 2024; 10:1105-1114. [PMID: 38799654 PMCID: PMC11117721 DOI: 10.1021/acscentsci.3c01564] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Revised: 04/12/2024] [Accepted: 04/18/2024] [Indexed: 05/29/2024]
Abstract
Cyclooxygenase-2 (COX-2) is an enzyme that plays a pivotal role in peripheral inflammation and pain via the prostaglandin pathway. In the central nervous system (CNS), COX-2 is implicated in neurodegenerative and psychiatric disorders as a potential therapeutic target and biomarker. However, clinical studies with COX-2 have yielded inconsistent results, partly due to limited mechanistic understanding of how COX-2 activity relates to CNS pathology. Therefore, developing COX-2 positron emission tomography (PET) radiotracers for human neuroimaging is of interest. This study introduces [11C]BRD1158, which is a potent and uniquely fast-binding, selective COX-2 PET radiotracer. [11C]BRD1158 was developed by prioritizing potency at COX-2, isoform selectivity over COX-1, fast binding kinetics, and free fraction in the brain. Evaluated through in vivo PET neuroimaging in rodent models with human COX-2 overexpression, [11C]BRD1158 demonstrated high brain uptake, fast target-engagement, functional reversibility, and excellent specific binding, which is advantageous for human imaging applications. Lastly, post-mortem samples from Huntington's disease (HD) patients and preclinical HD mouse models showed that COX-2 levels were elevated specifically in disease-affected brain regions, primarily from increased expression in microglia. These findings indicate that COX-2 holds promise as a novel clinical marker of HD onset and progression, one of many potential applications of [11C]BRD1158 human PET.
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Affiliation(s)
- Michael
S. Placzek
- Athinoula
A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts 02129, United States
| | - Daniel K. Wilton
- Department
of Neurology and F.M. Kirby Neurobiology Center, Boston Children’s
Hospital, Harvard Medical School, Boston, Massachusetts 02115, United States
| | - Michel Weïwer
- Center
for the Development of Therapeutics, Broad
Institute of MIT and Harvard, 75 Ames Street, Cambridge, Massachusetts 02142, United States
| | - Mariah A. Manter
- Athinoula
A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts 02129, United States
- Lurie
Center for Autism, 1
Maguire Road, Lexington, Massachusetts 02421, United States
- Massachusetts
General Hospital, 55
Fruit St., Boston, Massachusetts 02114, United States
| | - Sarah E. Reid
- Athinoula
A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts 02129, United States
| | - Christopher J. Meyer
- Center
for the Development of Therapeutics, Broad
Institute of MIT and Harvard, 75 Ames Street, Cambridge, Massachusetts 02142, United States
| | - Arthur J. Campbell
- Center
for the Development of Therapeutics, Broad
Institute of MIT and Harvard, 75 Ames Street, Cambridge, Massachusetts 02142, United States
| | - Besnik Bajrami
- Center
for the Development of Therapeutics, Broad
Institute of MIT and Harvard, 75 Ames Street, Cambridge, Massachusetts 02142, United States
| | - Antoine Bigot
- Center
for the Development of Therapeutics, Broad
Institute of MIT and Harvard, 75 Ames Street, Cambridge, Massachusetts 02142, United States
| | - Sarah Bricault
- Athinoula
A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts 02129, United States
| | - Agathe Fayet
- Center
for the Development of Therapeutics, Broad
Institute of MIT and Harvard, 75 Ames Street, Cambridge, Massachusetts 02142, United States
| | - Arnaud Frouin
- Department
of Neurology and F.M. Kirby Neurobiology Center, Boston Children’s
Hospital, Harvard Medical School, Boston, Massachusetts 02115, United States
| | - Frederick Gergits
- Department
of Neurology and F.M. Kirby Neurobiology Center, Boston Children’s
Hospital, Harvard Medical School, Boston, Massachusetts 02115, United States
| | - Mehak Gupta
- Center
for the Development of Therapeutics, Broad
Institute of MIT and Harvard, 75 Ames Street, Cambridge, Massachusetts 02142, United States
| | - Wei Jiang
- Center
for the Development of Therapeutics, Broad
Institute of MIT and Harvard, 75 Ames Street, Cambridge, Massachusetts 02142, United States
| | - Michelle Melanson
- Center
for the Development of Therapeutics, Broad
Institute of MIT and Harvard, 75 Ames Street, Cambridge, Massachusetts 02142, United States
| | - Chiara D. Romano
- Center
for the Development of Therapeutics, Broad
Institute of MIT and Harvard, 75 Ames Street, Cambridge, Massachusetts 02142, United States
| | - Misha M. Riley
- Athinoula
A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts 02129, United States
| | - Jessica M. Wang
- Athinoula
A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts 02129, United States
| | - Hsiao-Ying Wey
- Athinoula
A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts 02129, United States
| | - Florence F. Wagner
- Center
for the Development of Therapeutics, Broad
Institute of MIT and Harvard, 75 Ames Street, Cambridge, Massachusetts 02142, United States
| | - Beth Stevens
- Department
of Neurology and F.M. Kirby Neurobiology Center, Boston Children’s
Hospital, Harvard Medical School, Boston, Massachusetts 02115, United States
- Stanley
Center for Psychiatric Research, Broad Institute
of MIT and Harvard, 75 Ames Street, Cambridge, Massachusetts 02142, United
- Howard
Hughes Medical Institute, Boston Children’s Hospital, Harvard Medical School, Boston, Massachusetts 02115, United States
| | - Jacob M. Hooker
- Athinoula
A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts 02129, United States
- Lurie
Center for Autism, 1
Maguire Road, Lexington, Massachusetts 02421, United States
- Massachusetts
General Hospital, 55
Fruit St., Boston, Massachusetts 02114, United States
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5
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Huang Q, Ying J, Yu W, Dong Y, Xiong H, Zhang Y, Liu J, Wang X, Hua F. P2X7 Receptor: an Emerging Target in Alzheimer's Disease. Mol Neurobiol 2024; 61:2866-2880. [PMID: 37940779 PMCID: PMC11043177 DOI: 10.1007/s12035-023-03699-9] [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: 06/15/2023] [Accepted: 10/06/2023] [Indexed: 11/10/2023]
Abstract
Alzheimer's disease (AD) is a major cause of age-related dementia, which is becoming a global health crisis. However, the pathogenesis and etiology of AD are still not fully understood. And there are no valid treatment methods or precise diagnostic tools for AD. There is increasing evidence that P2X7R expression is upregulated in AD and is involved in multiple related pathological processes such as Aβ plaques, neurogenic fiber tangles, oxidative stress, and chronic neuroinflammation. This suggests that P2X7R may be a key player in the development of AD. P2X7R is a member of the ligand-gated purinergic receptor (P2X) family. It has received attention in neuroscience due to its role in a wide range of aging and age-related neurological disorders. In this review, we summarize current information on the roles of P2X7R in AD and suggest potential pharmacological interventions to slow down AD progression.
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Affiliation(s)
- Qiang Huang
- Department of Anesthesiology, the Second Affiliated Hospital of Nanchang University, 1# Minde Road, Nanchang, 330006, Jiangxi, China
- Key Laboratory of Anesthesiology of Jiangxi Province, 1# Minde Road, 330006, Nanchang City, Jiangxi Province, People's Republic of China
| | - Jun Ying
- Department of Anesthesiology, the Second Affiliated Hospital of Nanchang University, 1# Minde Road, Nanchang, 330006, Jiangxi, China
- Key Laboratory of Anesthesiology of Jiangxi Province, 1# Minde Road, 330006, Nanchang City, Jiangxi Province, People's Republic of China
| | - Wen Yu
- Department of Anesthesiology, the Second Affiliated Hospital of Nanchang University, 1# Minde Road, Nanchang, 330006, Jiangxi, China
- Key Laboratory of Anesthesiology of Jiangxi Province, 1# Minde Road, 330006, Nanchang City, Jiangxi Province, People's Republic of China
| | - Yao Dong
- Department of Anesthesiology, the Second Affiliated Hospital of Nanchang University, 1# Minde Road, Nanchang, 330006, Jiangxi, China
- Key Laboratory of Anesthesiology of Jiangxi Province, 1# Minde Road, 330006, Nanchang City, Jiangxi Province, People's Republic of China
| | - Hao Xiong
- Department of Anesthesiology, the Second Affiliated Hospital of Nanchang University, 1# Minde Road, Nanchang, 330006, Jiangxi, China
- Key Laboratory of Anesthesiology of Jiangxi Province, 1# Minde Road, 330006, Nanchang City, Jiangxi Province, People's Republic of China
| | - Yiping Zhang
- Department of Anesthesiology, the Second Affiliated Hospital of Nanchang University, 1# Minde Road, Nanchang, 330006, Jiangxi, China
- Key Laboratory of Anesthesiology of Jiangxi Province, 1# Minde Road, 330006, Nanchang City, Jiangxi Province, People's Republic of China
| | - Jie Liu
- Department of Anesthesiology, the Second Affiliated Hospital of Nanchang University, 1# Minde Road, Nanchang, 330006, Jiangxi, China
- Key Laboratory of Anesthesiology of Jiangxi Province, 1# Minde Road, 330006, Nanchang City, Jiangxi Province, People's Republic of China
| | - Xifeng Wang
- Department of Anesthesiology, the First Affiliated Hospital of Nanchang University, 17# Yongwai Road, Nanchang, 330006, Jiangxi, China.
| | - Fuzhou Hua
- Department of Anesthesiology, the Second Affiliated Hospital of Nanchang University, 1# Minde Road, Nanchang, 330006, Jiangxi, China.
- Key Laboratory of Anesthesiology of Jiangxi Province, 1# Minde Road, 330006, Nanchang City, Jiangxi Province, People's Republic of China.
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6
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Yin Y, Wei L, Caseley EA, Lopez‐Charcas O, Wei Y, Li D, Muench SP, Roger S, Wang L, Jiang L. Leveraging the ATP-P2X7 receptor signalling axis to alleviate traumatic CNS damage and related complications. Med Res Rev 2023; 43:1346-1373. [PMID: 36924449 PMCID: PMC10947395 DOI: 10.1002/med.21952] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 11/11/2022] [Accepted: 02/28/2023] [Indexed: 03/18/2023]
Abstract
The P2X7 receptor is an exceptional member of the P2X purinergic receptor family, with its activation requiring high concentrations of extracellular adenosine 5'-triphosphate (ATP) that are often associated with tissue damage and inflammation. In the central nervous system (CNS), it is highly expressed in glial cells, particularly in microglia. In this review, we discuss the role and mechanisms of the P2X7 receptor in mediating neuroinflammation and other pathogenic events in a variety of traumatic CNS damage conditions, which lead to loss of neurological and cognitive functions. We raise the perspective on the steady progress in developing CNS-penetrant P2X7 receptor-specific antagonists that leverage the ATP-P2X7 receptor signaling axis as a potential therapeutic strategy to alleviate traumatic CNS damage and related complications.
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Affiliation(s)
- Yaling Yin
- Sino‐UK Joint Laboratory of Brain Function and Injury of Henan Province, Department of Physiology and PathophysiologyXinxiang Medical UniversityXinxiangChina
| | - Linyu Wei
- Sino‐UK Joint Laboratory of Brain Function and Injury of Henan Province, Department of Physiology and PathophysiologyXinxiang Medical UniversityXinxiangChina
| | - Emily A. Caseley
- Faculty of Biological Sciences, School of Biomedical SciencesUniversity of LeedsLeedsUK
| | - Osbaldo Lopez‐Charcas
- EA4245, Transplantation, Immunology and Inflammation, Faculty of MedicineUniversity of ToursToursFrance
| | - Yingjuan Wei
- Sino‐UK Joint Laboratory of Brain Function and Injury of Henan Province, Department of Physiology and PathophysiologyXinxiang Medical UniversityXinxiangChina
| | - Dongliang Li
- Sino‐UK Joint Laboratory of Brain Function and Injury of Henan Province, Department of Physiology and PathophysiologyXinxiang Medical UniversityXinxiangChina
- Sanquan College of Xinxiang Medical UniversityXinxiangChina
| | - Steve P. Muench
- Faculty of Biological Sciences, School of Biomedical SciencesUniversity of LeedsLeedsUK
| | - Sebastian Roger
- EA4245, Transplantation, Immunology and Inflammation, Faculty of MedicineUniversity of ToursToursFrance
| | - Lu Wang
- Sino‐UK Joint Laboratory of Brain Function and Injury of Henan Province, Department of Physiology and PathophysiologyXinxiang Medical UniversityXinxiangChina
| | - Lin‐Hua Jiang
- Sino‐UK Joint Laboratory of Brain Function and Injury of Henan Province, Department of Physiology and PathophysiologyXinxiang Medical UniversityXinxiangChina
- Faculty of Biological Sciences, School of Biomedical SciencesUniversity of LeedsLeedsUK
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7
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Cools R, Kerkhofs K, Leitao RCF, Bormans G. Preclinical Evaluation of Novel PET Probes for Dementia. Semin Nucl Med 2023; 53:599-629. [PMID: 37149435 DOI: 10.1053/j.semnuclmed.2023.03.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Accepted: 03/24/2023] [Indexed: 05/08/2023]
Abstract
The development of novel PET imaging agents that selectively bind specific dementia-related targets can contribute significantly to accurate, differential and early diagnosis of dementia causing diseases and support the development of therapeutic agents. Consequently, in recent years there has been a growing body of literature describing the development and evaluation of potential new promising PET tracers for dementia. This review article provides a comprehensive overview of novel dementia PET probes under development, classified by their target, and pinpoints their preclinical evaluation pathway, typically involving in silico, in vitro and ex/in vivo evaluation. Specific target-associated challenges and pitfalls, requiring extensive and well-designed preclinical experimental evaluation assays to enable successful clinical translation and avoid shortcomings observed for previously developed 'well-established' dementia PET tracers are highlighted in this review.
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Affiliation(s)
- Romy Cools
- Laboratory for Radiopharmaceutical Research, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium
| | - Kobe Kerkhofs
- Laboratory for Radiopharmaceutical Research, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium; NURA, Belgian Nuclear Research Centre (SCK CEN), Mol, Belgium
| | - Renan C F Leitao
- Laboratory for Radiopharmaceutical Research, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium
| | - Guy Bormans
- Laboratory for Radiopharmaceutical Research, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium.
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8
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Morgan J, Moreno O, Alves M, Baz Z, Menéndez Méndez A, Leister H, Melia C, Smith J, Visekruna A, Nicke A, Bhattacharya A, Ceusters M, Henshall DC, Gómez-Vallejo V, Llop J, Engel T. Increased uptake of the P2X7 receptor radiotracer 18 F-JNJ-64413739 in the brain and peripheral organs according to the severity of status epilepticus in male mice. Epilepsia 2023; 64:511-523. [PMID: 36507708 PMCID: PMC10108015 DOI: 10.1111/epi.17484] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Revised: 12/02/2022] [Accepted: 12/09/2022] [Indexed: 12/14/2022]
Abstract
OBJECTIVE The P2X7 receptor (P2X7R) is an important contributor to neuroinflammation, responding to extracellularly released adenosine triphosphate. Expression of the P2X7R is increased in the brain in experimental and human epilepsy, and genetic or pharmacologic targeting of the receptor can reduce seizure frequency and severity in preclinical models. Experimentally induced seizures also increase levels of the P2X7R in blood. Here, we tested 18 F-JNJ-64413739, a positron emission tomography (PET) P2X7R antagonist, as a potential noninvasive biomarker of seizure-damage and epileptogenesis. METHODS Status epilepticus was induced via an intra-amygdala microinjection of kainic acid. Static PET studies (30 min duration, initiated 30 min after tracer administration) were conducted 48 h after status epilepticus via an intravenous injection of 18 F-JNJ-64413739. PET images were coregistered with a brain magnetic resonance imaging atlas, tracer uptake was determined in the different brain regions and peripheral organs, and values were correlated to seizure severity during status epilepticus. 18 F-JNJ-64413739 was also applied to ex vivo human brain slices obtained following surgical resection for intractable temporal lobe epilepsy. RESULTS P2X7R radiotracer uptake correlated strongly with seizure severity during status epilepticus in brain structures including the cerebellum and ipsi- and contralateral cortex, hippocampus, striatum, and thalamus. In addition, a correlation between radiotracer uptake and seizure severity was also evident in peripheral organs such as the heart and the liver. Finally, P2X7R radiotracer uptake was found elevated in brain sections from patients with temporal lobe epilepsy when compared to control. SIGNIFICANCE Taken together, our data suggest that P2X7R-based PET imaging may help to identify seizure-induced neuropathology and temporal lobe epilepsy patients with increased P2X7R levels possibly benefitting from P2X7R-based treatments.
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Affiliation(s)
- James Morgan
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, Dublin, Ireland
- Division of Developmental Biology and Medicine, School of Medical Sciences, Faculty of Biology, Medicine, and Health, University of Manchester, Manchester, UK
| | - Oscar Moreno
- CIC biomaGUNE, Basque Research and Technology Alliance (BRTA), San Sebastian, Spain
| | - Mariana Alves
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, Dublin, Ireland
| | - Zuriñe Baz
- CIC biomaGUNE, Basque Research and Technology Alliance (BRTA), San Sebastian, Spain
| | - Aida Menéndez Méndez
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, Dublin, Ireland
| | - Hanna Leister
- Institute for Medical Microbiology and Hygiene, Philipps University, Marburg, Germany
| | - Ciara Melia
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, Dublin, Ireland
| | - Jonathon Smith
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, Dublin, Ireland
- FutureNeuro, Science Foundation Ireland (SFI) Research Centre for Chronic and Rare Neurological Diseases, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, Dublin, Ireland
| | - Alexander Visekruna
- Institute for Medical Microbiology and Hygiene, Philipps University, Marburg, Germany
| | - Annette Nicke
- Walther Straub Institute of Pharmacology and Toxicology, Ludwig Maximilian University of Munich, Munich, Germany
| | - Anindya Bhattacharya
- Neuroimmunology Discover, Neuroscience, Janssen Research and Development, San Diego, California, USA
| | - Marc Ceusters
- Neuroscience Therapeutic Area, Janssen Research and Development, Janssen Pharmaceutica, Beerse, Belgium
- Marc Ceusters Company, Beerse, Belgium
| | - David C Henshall
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, Dublin, Ireland
- FutureNeuro, Science Foundation Ireland (SFI) Research Centre for Chronic and Rare Neurological Diseases, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, Dublin, Ireland
| | | | - Jordi Llop
- CIC biomaGUNE, Basque Research and Technology Alliance (BRTA), San Sebastian, Spain
| | - Tobias Engel
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, Dublin, Ireland
- FutureNeuro, Science Foundation Ireland (SFI) Research Centre for Chronic and Rare Neurological Diseases, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, Dublin, Ireland
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9
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Spotlight on P2X7 Receptor PET Imaging: A Bright Target or a Failing Star? Int J Mol Sci 2023; 24:ijms24021374. [PMID: 36674884 PMCID: PMC9861945 DOI: 10.3390/ijms24021374] [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: 11/24/2022] [Revised: 12/23/2022] [Accepted: 01/07/2023] [Indexed: 01/13/2023] Open
Abstract
The homotrimeric P2X7 receptor (P2X7R) is expressed by virtually all cells of the innate and adaptive immune system and plays a crucial role in various pathophysiological processes such as autoimmune and neurodegenerative diseases, inflammation, neuropathic pain and cancer. Consequently, the P2X7R is considered a promising target for therapy and diagnosis. As the development of tracers comes hand-in-hand with the development of potent and selective receptor ligands, there is a rising number of PET tracers available in preclinical and clinical studies. This review analyzes the development of P2X7R positron emission tomography (PET) tracers and their potential in various PET imaging applications.
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10
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Mikkelsen JD, Aripaka SS, Kaad S, Pazarlar BA, Pinborg L, Finsen B, Varrone A, Bang-Andersen B, Bastlund JF. Characterization of the Novel P2X7 Receptor Radioligand [ 3H]JNJ-64413739 in Human Brain Tissue. ACS Chem Neurosci 2022; 14:111-118. [PMID: 36535632 PMCID: PMC9817075 DOI: 10.1021/acschemneuro.2c00561] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Radioligands targeting microglia cells have been developed to identify and determine neuroinflammation in the living brain. One recently discovered ligand is JNJ-64413739 that binds selectively to the purinergic receptor P2X7R. The expression of P2X7R is increased under inflammation; hence, the ligand is considered useful in the detection of neuroinflammation in the brain. [18F]JNJ-64413739 has been evaluated in healthy subjects with positron emission tomography; however, the in vitro binding properties of the ligand in human brain tissue have not been investigated. Therefore, the purpose of this study was to measure Bmax and Kd of [3H]JNJ-64413739 using autoradiography on human cortical tissue sections resected from a total of 48 patients with treatment-resistant epilepsy. Correlations between the specific binding of [3H]JNJ-64413739 with age, sex, and duration of disease were explored. Finally, to examine the relationship between P2X7R and TSPO availability, specific binding of [3H]JNJ-64413739 and [123I]CLINDE was examined in the same tissue. The binding was measured in both cortical gray and subcortical white matter. Saturation revealed a Kd (5 nM) value similar between gray and white matter but a larger Bmax in the white than in the gray matter. The binding was completely displaced by the cold ligand and structurally different P2X7R ligands. The variability in saturable binding among the samples was found to be 38% in gray and white matter but was not correlated to either age, sex, or the duration of the disease. Interestingly, there was no significant correlation between [3H]JNJ-64413739 and [123I]CLINDE binding. These data demonstrate that [3H]JNJ-64413739 is a suitable radioligand for evaluating the distribution and expression of the P2X7R in the human brain.
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Affiliation(s)
- Jens D. Mikkelsen
- Neurobiology
Research Unit, University Hospital Rigshospitalet, Copenhagen 2100, Denmark,Institute
of Neuroscience, University of Copenhagen, Copenhagen 2200, Denmark,Department
of Molecular Medicine, University of Southern
Denmark, Odense 5000, Denmark,. Tel.: +45 3545 6701
| | - Sanjay S. Aripaka
- Neurobiology
Research Unit, University Hospital Rigshospitalet, Copenhagen 2100, Denmark
| | - Sif Kaad
- Neurobiology
Research Unit, University Hospital Rigshospitalet, Copenhagen 2100, Denmark
| | - Burcu A. Pazarlar
- Neurobiology
Research Unit, University Hospital Rigshospitalet, Copenhagen 2100, Denmark,Physiology
Department, Faculty of Medicine, Izmir Katip
Celebi University, Izmir 35330, Turkey
| | - Lars Pinborg
- Neurobiology
Research Unit, University Hospital Rigshospitalet, Copenhagen 2100, Denmark,Epilepsy
Clinic, Department of Neurology, Copenhagen
University Hospital, Rigshospitalet, Copenhagen 2100, Denmark
| | - Bente Finsen
- Department
of Molecular Medicine, University of Southern
Denmark, Odense 5000, Denmark
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11
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Genetzakis E, Gilchrist J, Kassiou M, Figtree GA. Development and clinical translation of P2X7 receptor antagonists: A potential therapeutic target in coronary artery disease? Pharmacol Ther 2022; 237:108228. [DOI: 10.1016/j.pharmthera.2022.108228] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Revised: 05/17/2022] [Accepted: 06/06/2022] [Indexed: 12/12/2022]
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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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Brumberg J, Varrone A. New PET radiopharmaceuticals for imaging CNS diseases. Nucl Med Mol Imaging 2022. [DOI: 10.1016/b978-0-12-822960-6.00002-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
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14
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Chen Z, Haider A, Chen J, Xiao Z, Gobbi L, Honer M, Grether U, Arnold SE, Josephson L, Liang SH. The Repertoire of Small-Molecule PET Probes for Neuroinflammation Imaging: Challenges and Opportunities beyond TSPO. J Med Chem 2021; 64:17656-17689. [PMID: 34905377 PMCID: PMC9094091 DOI: 10.1021/acs.jmedchem.1c01571] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Neuroinflammation is an adaptive response of the central nervous system to diverse potentially injurious stimuli, which is closely associated with neurodegeneration and typically characterized by activation of microglia and astrocytes. As a noninvasive and translational molecular imaging tool, positron emission tomography (PET) could provide a better understanding of neuroinflammation and its role in neurodegenerative diseases. Ligands to translator protein (TSPO), a putative marker of neuroinflammation, have been the most commonly studied in this context, but they suffer from serious limitations. Herein we present a repertoire of different structural chemotypes and novel PET ligand design for classical and emerging neuroinflammatory targets beyond TSPO. We believe that this Perspective will support multidisciplinary collaborations in academic and industrial institutions working on neuroinflammation and facilitate the progress of neuroinflammation PET probe development for clinical use.
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Affiliation(s)
- Zhen Chen
- Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital & Department of Radiology, Harvard Medical School, Boston, MA, 02114, United States
| | - Ahmed Haider
- Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital & Department of Radiology, Harvard Medical School, Boston, MA, 02114, United States
| | - Jiahui Chen
- Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital & Department of Radiology, Harvard Medical School, Boston, MA, 02114, United States
| | - Zhiwei Xiao
- Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital & Department of Radiology, Harvard Medical School, Boston, MA, 02114, United States
| | - Luca Gobbi
- Pharma Research and Early Development, F. Hoffmann-La Roche Ltd, CH-4070 Basel, Switzerland
| | - Michael Honer
- Pharma Research and Early Development, F. Hoffmann-La Roche Ltd, CH-4070 Basel, Switzerland
| | - Uwe Grether
- Pharma Research and Early Development, F. Hoffmann-La Roche Ltd, CH-4070 Basel, Switzerland
| | - Steven E. Arnold
- Department of Neurology and the Massachusetts Alzheimer’s Disease Research Center, Massachusetts General Hospital, Harvard Medical School, 114 16th Street, Charlestown, Massachusetts 02129, USA
| | - Lee Josephson
- Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital & Department of Radiology, Harvard Medical School, Boston, MA, 02114, United States
| | - Steven H. Liang
- Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital & Department of Radiology, Harvard Medical School, Boston, MA, 02114, United States
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15
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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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16
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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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17
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Mertens N, Schmidt ME, Hijzen A, Van Weehaeghe D, Ravenstijn P, Depre M, de Hoon J, Van Laere K, Koole M. Minimally invasive quantification of cerebral P2X7R occupancy using dynamic [ 18F]JNJ-64413739 PET and MRA-driven image derived input function. Sci Rep 2021; 11:16172. [PMID: 34373571 PMCID: PMC8352986 DOI: 10.1038/s41598-021-95715-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2021] [Accepted: 07/29/2021] [Indexed: 01/21/2023] Open
Abstract
[18F]JNJ-64413739 has been evaluated as PET-ligand for in vivo quantification of purinergic receptor subtype 7 receptor (P2X7R) using Logan graphical analysis with a metabolite-corrected arterial plasma input function. In the context of a P2X7R PET dose occupancy study, we evaluated a minimally invasive approach by limiting arterial sampling to baseline conditions. Meanwhile, post dose distribution volumes (VT) under blocking conditions were estimated by combining baseline blood to plasma ratios and metabolite fractions with an MR angiography driven image derived input function (IDIF). Regional postdose VT,IDIF values were compared with corresponding VT,AIF estimates using a arterial input function (AIF), in terms of absolute values, test–retest reliability and receptor occupancy. Compared to an invasive AIF approach, postdose VT,IDIF values and corresponding receptor occupancies showed only limited bias (Bland–Altman analysis: 0.06 ± 0.27 and 3.1% ± 6.4%) while demonstrating a high correlation (Spearman ρ = 0.78 and ρ = 0.98 respectively). In terms of test–retest reliability, regional intraclass correlation coefficients were 0.98 ± 0.02 for VT,IDIF compared to 0.97 ± 0.01 for VT,AIF. These results confirmed that a postdose IDIF, guided by MR angiography and using baseline blood and metabolite data, can be considered for accurate [18F]JNJ-64413739 PET quantification in a repeated PET study design, thus avoiding multiple invasive arterial sampling and increasing dosing flexibility.
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Affiliation(s)
- Nathalie Mertens
- Nuclear Medicine and Molecular Imaging, Department of Imaging and Pathology, University Hospital and KU Leuven, Herestraat 49, 3000, Leuven, Belgium.
| | | | - Anja Hijzen
- Janssen Research and Development, Beerse, Belgium
| | - Donatienne Van Weehaeghe
- Nuclear Medicine and Molecular Imaging, Department of Imaging and Pathology, University Hospital and KU Leuven, Herestraat 49, 3000, Leuven, Belgium
| | | | - Marleen Depre
- Center for Clinical Pharmacology, University Hospital and KU Leuven, Leuven, Belgium
| | - Jan de Hoon
- Center for Clinical Pharmacology, University Hospital and KU Leuven, Leuven, Belgium
| | - Koen Van Laere
- Nuclear Medicine and Molecular Imaging, Department of Imaging and Pathology, University Hospital and KU Leuven, Herestraat 49, 3000, Leuven, Belgium
| | - Michel Koole
- Nuclear Medicine and Molecular Imaging, Department of Imaging and Pathology, University Hospital and KU Leuven, Herestraat 49, 3000, Leuven, Belgium
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18
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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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Zarrinmayeh H, Territo PR. Purinergic Receptors of the Central Nervous System: Biology, PET Ligands, and Their Applications. Mol Imaging 2021; 19:1536012120927609. [PMID: 32539522 PMCID: PMC7297484 DOI: 10.1177/1536012120927609] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Purinergic receptors play important roles in central nervous system (CNS). These receptors are involved in cellular neuroinflammatory responses that regulate functions of neurons, microglial and astrocytes. Based on their endogenous ligands, purinergic receptors are classified into P1 or adenosine, P2X and P2Y receptors. During brain injury or under pathological conditions, rapid diffusion of extracellular adenosine triphosphate (ATP) or uridine triphosphate (UTP) from the damaged cells, promote microglial activation that result in the changes in expression of several of these receptors in the brain. Imaging of the purinergic receptors with selective Positron Emission Tomography (PET) radioligands has advanced our understanding of the functional roles of some of these receptors in healthy and diseased brains. In this review, we have accumulated a list of currently available PET radioligands of the purinergic receptors that are used to elucidate the receptor functions and participations in CNS disorders. We have also reviewed receptors lacking radiotracer, laying the foundation for future discoveries of novel PET radioligands to reveal these receptors roles in CNS disorders.
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Affiliation(s)
- Hamideh Zarrinmayeh
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Paul R Territo
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, USA
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20
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Scott MC, Bedi SS, Olson SD, Sears CM, Cox CS. Microglia as therapeutic targets after neurological injury: strategy for cell therapy. Expert Opin Ther Targets 2021; 25:365-380. [PMID: 34029505 DOI: 10.1080/14728222.2021.1934447] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
INTRODUCTION Microglia is the resident tissue macrophages of the central nervous system. Prolonged microglial activation often occurs after traumatic brain injury and is associated with deteriorating neurocognitive outcomes. Resolution of microglial activation is associated with limited tissue loss and improved neurocognitive outcomes. Limiting the prolonged pro-inflammatory response and the associated secondary tissue injury provides the rationale and scientific premise for considering microglia as a therapeutic target. AREAS COVERED In this review, we discuss markers of microglial activation, such as immunophenotype and microglial response to injury, including cytokine/chemokine release, free radical formation, morphology, phagocytosis, and metabolic shifts. We compare the origin and role in neuroinflammation of microglia and monocytes/macrophages. We review potential therapeutic targets to shift microglial polarization. Finally, we review the effect of cell therapy on microglia. EXPERT OPINION Dysregulated microglial activation after neurologic injury, such as traumatic brain injury, can worsen tissue damage and functional outcomes. There are potential targets in microglia to attenuate this activation, such as proteins and molecules that regulate microglia polarization. Cellular therapeutics that limit, but do not eliminate, the inflammatory response have improved outcomes in animal models by reducing pro-inflammatory microglial activation via secondary signaling. These findings have been replicated in early phase clinical trials.
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Affiliation(s)
- M Collins Scott
- Department of Pediatric Surgery, University of Texas Health Science Center at Houston (Uthealth), USA
| | - Supinder S Bedi
- Department of Pediatric Surgery, University of Texas Medical School at Houston, Houston, Texas, USA
| | - Scott D Olson
- Department of Pediatric Surgery, University of Texas Medical School at Houston, Houston, Texas, USA
| | - Candice M Sears
- Department of Pediatric Surgery, University of Texas Medical School at Houston, Houston, Texas, USA
| | - Charles S Cox
- Department of Pediatric Surgery, University of Texas Medical School at Houston, Houston, Texas, USA
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21
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Territo PR, Zarrinmayeh H. P2X 7 Receptors in Neurodegeneration: Potential Therapeutic Applications From Basic to Clinical Approaches. Front Cell Neurosci 2021; 15:617036. [PMID: 33889073 PMCID: PMC8055960 DOI: 10.3389/fncel.2021.617036] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Accepted: 03/02/2021] [Indexed: 12/27/2022] Open
Abstract
Purinergic receptors play important roles in central nervous system (CNS), where the bulk of these receptors are implicated in neuroinflammatory responses and regulation of cellular function of neurons, microglial and astrocytes. Within the P2X receptor family, P2X7 receptor is generally known for its inactivity in normal conditions and activation by moderately high concentrations (>100 μM) of extracellular adenosine 5′-triphosphate (ATP) released from injured cells as a result of brain injury or pathological conditions. Activation of P2X7R contributes to the activation and proliferation of microglia and directly contribute to neurodegeneration by provoking microglia-mediated neuronal death, glutamate-mediated excitotoxicity, and NLRP3 inflammasome activation that results in initiation, maturity and release of the pro-inflammatory cytokines and generation of reactive oxygen and nitrogen species. These components of the inflammatory response play important roles in many neural pathologies and neurodegeneration disorders. In CNS, expression of P2X7R on microglia, astrocytes, and oligodendrocytes are upregulated under neuroinflammatory conditions. Several in vivo studies have demonstrated beneficial effects of the P2X7 receptor antagonists in animal model systems of neurodegenerative diseases. A number of specific and selective P2X7 receptor antagonists have been developed, but only few of them have shown efficient brain permeability. Finding potent and selective P2X7 receptor inhibitors which are also CNS penetrable and display acceptable pharmacokinetics (PK) has presented challenges for both academic researchers and pharmaceutical companies. In this review, we discuss the role of P2X7 receptor function in neurodegenerative diseases, the pharmacological inhibition of the receptor, and PET radiopharmaceuticals which permit non-invasive monitoring of the P2X7 receptor contribution to neuroinflammation associated with neurodegeneration.
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Affiliation(s)
- Paul R Territo
- Department of Medicine, Indiana University School of Medicine, Indianapolis, IN, United States.,Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, United States
| | - Hamideh Zarrinmayeh
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, United States
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22
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Imaging Inflammation with Positron Emission Tomography. Biomedicines 2021; 9:biomedicines9020212. [PMID: 33669804 PMCID: PMC7922638 DOI: 10.3390/biomedicines9020212] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2021] [Revised: 01/28/2021] [Accepted: 02/12/2021] [Indexed: 12/19/2022] Open
Abstract
The impact of inflammation on the outcome of many medical conditions such as cardiovascular diseases, neurological disorders, infections, cancer, and autoimmune diseases has been widely acknowledged. However, in contrast to neurological, oncologic, and cardiovascular disorders, imaging plays a minor role in research and management of inflammation. Imaging can provide insights into individual and temporospatial biology and grade of inflammation which can be of diagnostic, therapeutic, and prognostic value. There is therefore an urgent need to evaluate and understand current approaches and potential applications for imaging of inflammation. This review discusses radiotracers for positron emission tomography (PET) that have been used to image inflammation in cardiovascular diseases and other inflammatory conditions with a special emphasis on radiotracers that have already been successfully applied in clinical settings.
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Goud NS, Bhattacharya A, Joshi RK, Nagaraj C, Bharath RD, Kumar P. Carbon-11: Radiochemistry and Target-Based PET Molecular Imaging Applications in Oncology, Cardiology, and Neurology. J Med Chem 2021; 64:1223-1259. [PMID: 33499603 DOI: 10.1021/acs.jmedchem.0c01053] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The positron emission tomography (PET) molecular imaging technique has gained its universal value as a remarkable tool for medical diagnosis and biomedical research. Carbon-11 is one of the promising radiotracers that can report target-specific information related to its pharmacology and physiology to understand the disease status. Currently, many of the available carbon-11 (t1/2 = 20.4 min) PET radiotracers are heterocyclic derivatives that have been synthesized using carbon-11 inserted different functional groups obtained from primary and secondary carbon-11 precursors. A spectrum of carbon-11 PET radiotracers has been developed against many of the upregulated and emerging targets for the diagnosis, prognosis, prediction, and therapy in the fields of oncology, cardiology, and neurology. This review focuses on the carbon-11 radiochemistry and various target-specific PET molecular imaging agents used in tumor, heart, brain, and neuroinflammatory disease imaging along with its associated pathology.
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Affiliation(s)
- Nerella Sridhar Goud
- Department of Neuroimaging and Interventional Radiology (NIIR), National Institute of Mental Health and Neuro Sciences (NIMHANS), Bengaluru 560 029, India
| | - Ahana Bhattacharya
- Department of Neuroimaging and Interventional Radiology (NIIR), National Institute of Mental Health and Neuro Sciences (NIMHANS), Bengaluru 560 029, India
| | - Raman Kumar Joshi
- Department of Neuroimaging and Interventional Radiology (NIIR), National Institute of Mental Health and Neuro Sciences (NIMHANS), Bengaluru 560 029, India
| | - Chandana Nagaraj
- Department of Neuroimaging and Interventional Radiology (NIIR), National Institute of Mental Health and Neuro Sciences (NIMHANS), Bengaluru 560 029, India
| | - Rose Dawn Bharath
- Department of Neuroimaging and Interventional Radiology (NIIR), National Institute of Mental Health and Neuro Sciences (NIMHANS), Bengaluru 560 029, India
| | - Pardeep Kumar
- Department of Neuroimaging and Interventional Radiology (NIIR), National Institute of Mental Health and Neuro Sciences (NIMHANS), Bengaluru 560 029, India
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Beaino W, Janssen B, Kooijman E, Vos R, Schuit RC, O'Brien-Brown J, Kassiou M, van Het Hof B, Vugts DJ, de Vries HE, Windhorst AD. PET imaging of P2X 7R in the experimental autoimmune encephalomyelitis model of multiple sclerosis using [ 11C]SMW139. J Neuroinflammation 2020; 17:300. [PMID: 33054803 PMCID: PMC7556947 DOI: 10.1186/s12974-020-01962-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Accepted: 09/23/2020] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Non-invasive imaging of the activation status of microglia and the ability to identify a pro- or anti-inflammatory environment can provide valuable insights not only into pathogenesis of neuro-inflammatory and neurodegenerative diseases but also the monitoring of the efficacy of immunomodulatory therapies. P2X7R is highly expressed on pro-inflammatory microglia and [11C]SMW139, a specific P2X7R tracer for positron emission tomography imaging, showed good pharmacokinetics, stability, and brain permeability in vivo. Our objective was to evaluate the potential of [11C]SMW139 for PET imaging of neuroinflammation in vivo in the experimental autoimmune encephalomyelitis (EAE) model. METHODS We induced EAE in Lewis rats by immunization with MBP 69-88 in complete Freund's adjuvant (CFA). We determined the affinity of [11C]SMW139 to human and rat P2X7R using saturation binding assay. Using this tracer, PET imaging was performed at the peak of disease and in the recovery phase. In vivo blocking experiments were conducted to validate the specific brain uptake of the tracer. Immunohistochemistry staining and autoradiography were performed to evaluate the level of neuroinflammation and validate the specific binding of [11C]SMW139. RESULTS [11C]SMW139 showed good affinity for the rat P2X7R with a Kd of 20.6 ± 1.7 nM. The uptake of [11C]SMW139 was significantly higher in EAE animals at the peak of disease compared to the recovery phase but not in CFA control animals. The amplitude of increase of [11C]SMW139 uptake showed significant positive correlation with clinical scores mainly in the spinal cord (Pearson = 0.75, Spearman = 0.76; p < 0.0001). Treating EAE animals with P2X7R antagonist JNJ-47965567 blocked the uptake of [11C]SMW139 in the spinal cord, cerebellum, and brain stem, demonstrating specific accumulation of the tracer. P-glycoprotein blocking with tariquidar (30 mg/kg) did not affect tracer penetration in the brain showing that [11C]SMW139 is not a Pgp substrate. CONCLUSION Our data shows that [11C]SMW139 is a promising PET tracer for imaging neuroinflammation and evaluating the dynamics of pro-inflammatory microglia in the brain. This can provide crucial insights into the role of microglia in disease progression and enables the development of novel treatment strategies aimed at modulating the immune response in order to promote neuroprotection.
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Affiliation(s)
- Wissam Beaino
- Department of Radiology and Nuclear Medicine, Amsterdam UMC, location VUmc, Amsterdam, The Netherlands.
| | - Bieneke Janssen
- Department of Radiology and Nuclear Medicine, Amsterdam UMC, location VUmc, Amsterdam, The Netherlands.,Present address: Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Esther Kooijman
- Department of Radiology and Nuclear Medicine, Amsterdam UMC, location VUmc, Amsterdam, The Netherlands
| | - Ricardo Vos
- Department of Radiology and Nuclear Medicine, Amsterdam UMC, location VUmc, Amsterdam, The Netherlands
| | - Robert C Schuit
- Department of Radiology and Nuclear Medicine, Amsterdam UMC, location VUmc, Amsterdam, The Netherlands
| | | | - Michael Kassiou
- School of Chemistry, The University of Sydney, Sydney, NSW, Australia
| | - Bert van Het Hof
- Department of Molecular Cell Biology and Immunology, AUMC MS Center Amsterdam, Amsterdam Neuroscience, Amsterdam University Medical Center, Amsterdam, The Netherlands
| | - Danielle J Vugts
- Department of Radiology and Nuclear Medicine, Amsterdam UMC, location VUmc, Amsterdam, The Netherlands
| | - Helga E de Vries
- Department of Molecular Cell Biology and Immunology, AUMC MS Center Amsterdam, Amsterdam Neuroscience, Amsterdam University Medical Center, Amsterdam, The Netherlands
| | - Albert D Windhorst
- Department of Radiology and Nuclear Medicine, Amsterdam UMC, location VUmc, Amsterdam, The Netherlands
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Positron Emission Tomography in the Inflamed Cerebellum: Addressing Novel Targets among G Protein-Coupled Receptors and Immune Receptors. Pharmaceutics 2020; 12:pharmaceutics12100925. [PMID: 32998351 PMCID: PMC7601272 DOI: 10.3390/pharmaceutics12100925] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Revised: 09/17/2020] [Accepted: 09/25/2020] [Indexed: 01/12/2023] Open
Abstract
Inflammatory processes preceding clinical manifestation of brain diseases are moving increasingly into the focus of positron emission tomographic (PET) investigations. A key role in inflammation and as a target of PET imaging efforts is attributed to microglia. Cerebellar microglia, with a predominant ameboid and activated subtype, is of special interest also regarding improved and changing knowledge on functional involvement of the cerebellum in mental activities in addition to its regulatory role in motor function. The present contribution considers small molecule ligands as potential PET tools for the visualization of several receptors recognized to be overexpressed in microglia and which can potentially serve as indicators of inflammatory processes in the cerebellum. The sphingosine 1 phosphate receptor 1 (S1P1), neuropeptide Y receptor 2 (NPY2) and purinoceptor Y12 (P2Y12) cannabinoid receptors and the chemokine receptor CX3CR1 as G-protein-coupled receptors and the ionotropic purinoceptor P2X7 provide structures with rather classical binding behavior, while the immune receptor for advanced glycation end products (RAGE) and the triggering receptor expressed on myeloid cells 2 (TREM2) might depend for instance on further accessory proteins. Improvement in differentiation between microglial functional subtypes in comparison to the presently used 18 kDa translocator protein ligands as well as of the knowledge on the role of polymorphisms are special challenges in such developments.
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P2X7 Receptors Amplify CNS Damage in Neurodegenerative Diseases. Int J Mol Sci 2020; 21:ijms21175996. [PMID: 32825423 PMCID: PMC7504621 DOI: 10.3390/ijms21175996] [Citation(s) in RCA: 66] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 08/07/2020] [Accepted: 08/17/2020] [Indexed: 12/11/2022] Open
Abstract
ATP is a (co)transmitter and signaling molecule in the CNS. It acts at a multitude of ligand-gated cationic channels termed P2X to induce rapid depolarization of the cell membrane. Within this receptor-channel family, the P2X7 receptor (R) allows the transmembrane fluxes of Na+, Ca2+, and K+, but also allows the slow permeation of larger organic molecules. This is supposed to cause necrosis by excessive Ca2+ influx, as well as depletion of intracellular ions and metabolites. Cell death may also occur by apoptosis due to the activation of the caspase enzymatic cascade. Because P2X7Rs are localized in the CNS preferentially on microglia, but also at a lower density on neuroglia (astrocytes, oligodendrocytes) the stimulation of this receptor leads to the release of neurodegeneration-inducing bioactive molecules such as pro-inflammatory cytokines, chemokines, proteases, reactive oxygen and nitrogen molecules, and the excitotoxic glutamate/ATP. Various neurodegenerative reactions of the brain/spinal cord following acute harmful events (mechanical CNS damage, ischemia, status epilepticus) or chronic neurodegenerative diseases (neuropathic pain, Alzheimer’s disease, Parkinson’s disease, multiple sclerosis, amyotrophic lateral sclerosis) lead to a massive release of ATP via the leaky plasma membrane of neural tissue. This causes cellular damage superimposed on the original consequences of neurodegeneration. Hence, blood-brain-barrier permeable pharmacological antagonists of P2X7Rs with excellent bioavailability are possible therapeutic agents for these diseases. The aim of this review article is to summarize our present state of knowledge on the involvement of P2X7R-mediated events in neurodegenerative illnesses endangering especially the life quality and duration of the aged human population.
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Abstract
Neuroimaging with positron emission tomography (PET) is the most powerful tool for understanding pharmacology, neurochemistry, and pathology in the living human brain. This technology combines high-resolution scanners to measure radioactivity throughout the human body with specific, targeted radioactive molecules, which allow measurements of a myriad of biological processes in vivo. While PET brain imaging has been active for almost 40 years, the pace of development for neuroimaging tools, known as radiotracers, and for quantitative analytical techniques has increased dramatically over the past decade. Accordingly, the fundamental questions that can be addressed with PET have expanded in basic neurobiology, psychiatry, neurology, and related therapeutic development. In this review, we introduce the field of human PET neuroimaging, some of its conceptual underpinnings, and motivating questions. We highlight some of the more recent advances in radiotracer development, quantitative modeling, and applications of PET to the study of the human brain.
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Affiliation(s)
- Jacob M Hooker
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts 02129, USA;
| | - Richard E Carson
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, Connecticut 06520, USA;
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29
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Zheng QH. Radioligands targeting purinergic P2X7 receptor. Bioorg Med Chem Lett 2020; 30:127169. [DOI: 10.1016/j.bmcl.2020.127169] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Revised: 04/01/2020] [Accepted: 04/02/2020] [Indexed: 12/12/2022]
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Berdyyeva T, Xia C, Taylor N, He Y, Chen G, Huang C, Zhang W, Kolb H, Letavic M, Bhattacharya A, Szardenings AK. PET Imaging of the P2X7 Ion Channel with a Novel Tracer [ 18F]JNJ-64413739 in a Rat Model of Neuroinflammation. Mol Imaging Biol 2020; 21:871-878. [PMID: 30632003 DOI: 10.1007/s11307-018-01313-2] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
PURPOSE The P2X7 receptor, an adenosine triphosphate (ATP)-gated purinoreceptor, has emerged as one of the key players in neuroinflammatory processes. Therefore, developing a positron emission tomography (PET) tracer for imaging of P2X7 receptors in vivo presents a promising approach to diagnose, monitor, and study neuroinflammation in a variety of brain disorders. To fulfill the goal of developing a P2X7 PET ligand as a biomarker of neuroinflammation, [18F]JNJ-64413739 has been recently disclosed. PROCEDURES We evaluated [18F]JNJ-64413739 in a rat model of neuroinflammation induced by an intracerebral injection of lipopolysaccharide (LPS). In vivo brain uptake was determined by PET imaging. Upregulation of neuroinflammatory biomarkers was determined by quantitative polymerase chain reaction (qPCR). Distribution of the tracer in the brain was determined by ex vivo autoradiography (ARG). The specificity of [18F]JNJ-64413739 was confirmed by performing blocking experiments with the P2X7 antagonist JNJ-54175446. RESULTS Brain regions of rats injected with LPS had a significantly increased uptake (34 % ± 3 % s.e.m., p = 0.036, t test, standardized uptake value measured over the entire scanning period) of [18F]JNJ-64413739 relative to the corresponding brain regions of control animals injected with phosphate-buffered saline (PBS). The uptake in the contralateral regions and cerebellum was not significantly different between the groups of animals. The increase in uptake of [18F]JNJ-64413739 at the LPS-injected site observed by PET imaging was concordant with ex vivo ARG, upregulation of neuroinflammatory biomarkers, and elevated P2X7 expression levels. CONCLUSIONS While further work is needed to study [18F]JNJ-64413739 in other types of neuroinflammation, the current results favorably characterize [18F]JNJ-64413739 as a potential PET tracer of central neuroinflammation.
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Affiliation(s)
- Tamara Berdyyeva
- Janssen Research & Development LLC, 3210 Merryfield Row, San Diego, CA, 92121, USA.
| | - Chunfang Xia
- Janssen Research & Development LLC, 3210 Merryfield Row, San Diego, CA, 92121, USA
| | - Natalie Taylor
- Janssen Research & Development LLC, 3210 Merryfield Row, San Diego, CA, 92121, USA
| | - Yingbo He
- Janssen Research & Development LLC, 3210 Merryfield Row, San Diego, CA, 92121, USA
| | - Gang Chen
- Janssen Research & Development LLC, 3210 Merryfield Row, San Diego, CA, 92121, USA
| | - Chaofeng Huang
- Janssen Research & Development LLC, 3210 Merryfield Row, San Diego, CA, 92121, USA
| | - Wei Zhang
- Janssen Research & Development LLC, 3210 Merryfield Row, San Diego, CA, 92121, USA
| | - Hartmuth Kolb
- Janssen Research & Development LLC, 3210 Merryfield Row, San Diego, CA, 92121, USA
| | - Michael Letavic
- Janssen Research & Development LLC, 3210 Merryfield Row, San Diego, CA, 92121, USA
| | - Anindya Bhattacharya
- Janssen Research & Development LLC, 3210 Merryfield Row, San Diego, CA, 92121, USA
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Abstract
This review discusses nuclear imaging of inflammation using molecular probes beyond fluoro-d-glucose, is structured by cellular targets, and focuses on those tracers that have been successfully applied clinically.
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Affiliation(s)
- Malte Kircher
- Department of Nuclear Medicine, University Hospital Augsburg, Stenglinstr. 2, Würzburg 86156, Germany
| | - Constantin Lapa
- Department of Nuclear Medicine, University Hospital Augsburg, Stenglinstr. 2, Würzburg 86156, Germany.
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McCluskey SP, Plisson C, Rabiner EA, Howes O. Advances in CNS PET: the state-of-the-art for new imaging targets for pathophysiology and drug development. Eur J Nucl Med Mol Imaging 2020; 47:451-489. [PMID: 31541283 PMCID: PMC6974496 DOI: 10.1007/s00259-019-04488-0] [Citation(s) in RCA: 73] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Accepted: 08/15/2019] [Indexed: 02/07/2023]
Abstract
PURPOSE A limit on developing new treatments for a number of central nervous system (CNS) disorders has been the inadequate understanding of the in vivo pathophysiology underlying neurological and psychiatric disorders and the lack of in vivo tools to determine brain penetrance, target engagement, and relevant molecular activity of novel drugs. Molecular neuroimaging provides the tools to address this. This article aims to provide a state-of-the-art review of new PET tracers for CNS targets, focusing on developments in the last 5 years for targets recently available for in-human imaging. METHODS We provide an overview of the criteria used to evaluate PET tracers. We then used the National Institute of Mental Health Research Priorities list to identify the key CNS targets. We conducted a PubMed search (search period 1st of January 2013 to 31st of December 2018), which yielded 40 new PET tracers across 16 CNS targets which met our selectivity criteria. For each tracer, we summarised the evidence of its properties and potential for use in studies of CNS pathophysiology and drug evaluation, including its target selectivity and affinity, inter and intra-subject variability, and pharmacokinetic parameters. We also consider its potential limitations and missing characterisation data, but not specific applications in drug development. Where multiple tracers were present for a target, we provide a comparison of their properties. RESULTS AND CONCLUSIONS Our review shows that multiple new tracers have been developed for proteinopathy targets, particularly tau, as well as the purinoceptor P2X7, phosphodiesterase enzyme PDE10A, and synaptic vesicle glycoprotein 2A (SV2A), amongst others. Some of the most promising of these include 18F-MK-6240 for tau imaging, 11C-UCB-J for imaging SV2A, 11C-CURB and 11C-MK-3168 for characterisation of fatty acid amide hydrolase, 18F-FIMX for metabotropic glutamate receptor 1, and 18F-MNI-444 for imaging adenosine 2A. Our review also identifies recurrent issues within the field. Many of the tracers discussed lack in vivo blocking data, reducing confidence in selectivity. Additionally, late-stage identification of substantial off-target sites for multiple tracers highlights incomplete pre-clinical characterisation prior to translation, as well as human disease state studies carried out without confirmation of test-retest reproducibility.
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Affiliation(s)
- Stuart P McCluskey
- Invicro LLC, A Konica Minolta Company, Burlington Danes Building, Imperial College London, Hammersmith Hospital, Du Cane Road, London, W12 0NN, UK.
- Psychiatric Imaging Group, MRC London Institute of Medical Sciences, Imperial College London, Hammersmith Hospital, London, UK.
| | - Christophe Plisson
- Invicro LLC, A Konica Minolta Company, Burlington Danes Building, Imperial College London, Hammersmith Hospital, Du Cane Road, London, W12 0NN, UK
| | - Eugenii A Rabiner
- Invicro LLC, A Konica Minolta Company, Burlington Danes Building, Imperial College London, Hammersmith Hospital, Du Cane Road, London, W12 0NN, UK
| | - Oliver Howes
- Psychiatric Imaging Group, MRC London Institute of Medical Sciences, Imperial College London, Hammersmith Hospital, London, UK
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New approach in radiometabolite analysis of positron emission tomography (PET) radioligands; lead-shielded microextraction by packed sorbent as a tool for in vivo radiometabolite analysis of [11C]SMW139 in rat plasma. Talanta 2020; 208:120449. [DOI: 10.1016/j.talanta.2019.120449] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2019] [Revised: 10/01/2019] [Accepted: 10/04/2019] [Indexed: 02/05/2023]
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Gelin CF, Bhattacharya A, Letavic MA. P2X7 receptor antagonists for the treatment of systemic inflammatory disorders. PROGRESS IN MEDICINAL CHEMISTRY 2020; 59:63-99. [PMID: 32362329 DOI: 10.1016/bs.pmch.2019.11.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
P2X7 has continued to be a target of immense interest since it is implicated in several peripheral and central nervous system disorders that result from inflammation. This review primarily describes new P2X7 receptor antagonists that have been investigated and disclosed in patent applications or primary literature since 2015. While a crystal structure of the receptor to aid in the design of novel chemical structures remains elusive, many of the chemotypes that have been disclosed contain similarities, with an amide motif present in all series that have been explored to date. Several of the recent antagonists described are brain penetrant, and two compounds are currently in clinical trials for CNS indications. Additionally, brain penetrant PET ligands have been developed that aid in measuring target engagement and these ligands can potentially be used as biomarkers.
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Affiliation(s)
- Christine F Gelin
- Discovery Chemistry, Discovery Sciences, Janssen Research and Development, LLC, San Diego, CA, United States.
| | - Anindya Bhattacharya
- Neuroscience, Janssen Research and Development, LLC, San Diego, CA, United States
| | - Michael A Letavic
- Discovery Chemistry, Discovery Sciences, Janssen Research and Development, LLC, San Diego, CA, United States
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Hagens MHJ, Golla SSV, Janssen B, Vugts DJ, Beaino W, Windhorst AD, O’Brien-Brown J, Kassiou M, Schuit RC, Schwarte LA, de Vries HE, Killestein J, Barkhof F, van Berckel BNM, Lammertsma AA. The P2X 7 receptor tracer [ 11C]SMW139 as an in vivo marker of neuroinflammation in multiple sclerosis: a first-in man study. Eur J Nucl Med Mol Imaging 2019; 47:379-389. [PMID: 31705174 PMCID: PMC6974509 DOI: 10.1007/s00259-019-04550-x] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Accepted: 09/24/2019] [Indexed: 12/21/2022]
Abstract
Purpose The novel PET tracer [11C]SMW139 binds with high affinity to the P2X7 receptor, which is expressed on pro-inflammatory microglia. The purposes of this first in-man study were to characterise pharmacokinetics of [11C]SMW139 in patients with active relapsing remitting multiple sclerosis (RRMS) and healthy controls (HC) and to evaluate its potential to identify in vivo neuroinflammation in RRMS. Methods Five RRMS patients and 5 age-matched HC underwent 90-min dynamic [11C]SMW139 PET scans, with online continuous and manual arterial sampling to generate a metabolite-corrected arterial plasma input function. Tissue time activity curves were fitted to single- and two-tissue compartment models, and the model that provided the best fits was determined using the Akaike information criterion. Results The optimal model for describing [11C]SMW139 kinetics in both RRMS and HC was a reversible two-tissue compartment model with blood volume parameter and with the dissociation rate k4 fixed to the whole-brain value. Exploratory group level comparisons demonstrated an increased volume of distribution (VT) and binding potential (BPND) in RRMS compared with HC in normal appearing brain regions. BPND in MS lesions was decreased compared with non-lesional white matter, and a further decrease was observed in gadolinium-enhancing lesions. In contrast, increased VT was observed in enhancing lesions, possibly resulting from disruption of the blood-brain barrier in active MS lesions. In addition, there was a high correlation between parameters obtained from 60- to 90-min datasets, although analyses using 60-min data led to a slight underestimation in regional VT and BPND values. Conclusions This first in-man study demonstrated that uptake of [11C]SMW139 can be quantified with PET using BPND as a measure for specific binding in healthy controls and RRMS patients. Additional studies are warranted for further clinical evaluation of this novel neuroinflammation tracer. Electronic supplementary material The online version of this article (10.1007/s00259-019-04550-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Marloes H. J. Hagens
- MS Center Amsterdam, Amsterdam Neuroscience, Amsterdam UMC - location VUmc, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands
- Department of Neurology, Amsterdam Neuroscience, Amsterdam UMC - location VUmc, De Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands
| | - Sandeep S. V. Golla
- Department of Radiology and Nuclear Medicine, Amsterdam Neuroscience, Amsterdam UMC - location VUmc, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands
| | - Bieneke Janssen
- Department of Radiology and Nuclear Medicine, Amsterdam Neuroscience, Amsterdam UMC - location VUmc, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands
| | - Danielle J. Vugts
- Department of Radiology and Nuclear Medicine, Amsterdam Neuroscience, Amsterdam UMC - location VUmc, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands
| | - Wissam Beaino
- Department of Molecular Cell Biology and Immunology, Amsterdam UMC - location VUmc, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands
| | - Albert D. Windhorst
- Department of Radiology and Nuclear Medicine, Amsterdam Neuroscience, Amsterdam UMC - location VUmc, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands
| | | | - Michael Kassiou
- School of Chemistry, University of Sydney, Sydney, Australia
| | - Robert C. Schuit
- Department of Radiology and Nuclear Medicine, Amsterdam Neuroscience, Amsterdam UMC - location VUmc, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands
| | - Lothar A. Schwarte
- Department of Anaesthesiology, Amsterdam UMC - location VUmc, De Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands
| | - Helga E. de Vries
- MS Center Amsterdam, Amsterdam Neuroscience, Amsterdam UMC - location VUmc, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands
- Department of Molecular Cell Biology and Immunology, Amsterdam UMC - location VUmc, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands
| | - Joep Killestein
- MS Center Amsterdam, Amsterdam Neuroscience, Amsterdam UMC - location VUmc, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands
- Department of Neurology, Amsterdam Neuroscience, Amsterdam UMC - location VUmc, De Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands
| | - Frederik Barkhof
- MS Center Amsterdam, Amsterdam Neuroscience, Amsterdam UMC - location VUmc, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands
- Department of Radiology and Nuclear Medicine, Amsterdam Neuroscience, Amsterdam UMC - location VUmc, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands
- Institutes of Neurology and Healthcare Engineering, UCL Institute of Neurology, London, UK
| | - Bart N. M. van Berckel
- Department of Radiology and Nuclear Medicine, Amsterdam Neuroscience, Amsterdam UMC - location VUmc, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands
| | - Adriaan A. Lammertsma
- Department of Radiology and Nuclear Medicine, Amsterdam Neuroscience, Amsterdam UMC - location VUmc, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands
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Van Weehaeghe D, Van Schoor E, De Vocht J, Koole M, Attili B, Celen S, Declercq L, Thal DR, Van Damme P, Bormans G, Van Laere K. TSPO Versus P2X7 as a Target for Neuroinflammation: An In Vitro and In Vivo Study. J Nucl Med 2019; 61:604-607. [PMID: 31562223 DOI: 10.2967/jnumed.119.231985] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Accepted: 08/26/2019] [Indexed: 12/12/2022] Open
Abstract
Neuroinflammation is important in amyotrophic lateral sclerosis (ALS). The P2X7 receptor (P2X7R) is a promising target for neuroinflammation. The objective of this study was to compare 18F-DPA714, a second-generation translocator protein tracer, with 11C-JNJ717, a novel P2X7R tracer, in vitro and in vivo in ALS. Methods: For the in vitro portion of the study, autoradiography with 18F-DPA714 and 11C-JNJ717 was performed on human ALS brain sections in comparison to immunofluorescence with Iba1 and GFAP. For the in vivo portion, 3 male patients with early-stage ALS (59.3 ± 7.2 y old) and 6 healthy volunteers (48.2 ± 16.5 y old, 2 men and 4 women) underwent dynamic PET/MR scanning with 18F-DPA714 and 11C-JNJ717. Volume-of-distribution images were calculated using Logan plots and analyzed on a volume-of-interest basis. Results: Autoradiography showed no difference in 11C-JNJ717 binding but did show increased 18F-DPA714 binding in the motor cortex correlating with Iba1 expression (glial cells). Similar findings were observed in vivo, with a 13% increase in 18F-DPA714 binding in the motor cortex. Conclusion: In symptomatic ALS patients, 18F-DPA714 showed increased signal whereas 11C-JNJ717 was not elevated.
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Affiliation(s)
- Donatienne Van Weehaeghe
- Division of Nuclear Medicine, Department of Imaging and Pathology, University Hospitals Leuven, KU Leuven, Leuven, Belgium
| | - Evelien Van Schoor
- Department of Neurology, University Hospitals Leuven, and Laboratory of Neurobiology, Center for Brain and Disease Research, VIB, KU Leuven, Leuven, Belgium.,Leuven Brain Institute, KU Leuven, Leuven, Belgium.,Laboratory for Neuropathology, Department of Imaging and Pathology, KU Leuven, Leuven, Belgium
| | - Joke De Vocht
- Department of Neurology, University Hospitals Leuven, and Laboratory of Neurobiology, Center for Brain and Disease Research, VIB, KU Leuven, Leuven, Belgium
| | - Michel Koole
- Division of Nuclear Medicine, Department of Imaging and Pathology, University Hospitals Leuven, KU Leuven, Leuven, Belgium
| | - Bala Attili
- Laboratory for Radiopharmaceutical Research, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium; and
| | - Sofie Celen
- Laboratory for Radiopharmaceutical Research, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium; and
| | - Lieven Declercq
- Laboratory for Radiopharmaceutical Research, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium; and
| | - Dietmar R Thal
- Leuven Brain Institute, KU Leuven, Leuven, Belgium.,Laboratory for Neuropathology, Department of Imaging and Pathology, KU Leuven, Leuven, Belgium.,Department of Pathology, UZ Leuven, Leuven, Belgium
| | - Philip Van Damme
- Department of Neurology, University Hospitals Leuven, and Laboratory of Neurobiology, Center for Brain and Disease Research, VIB, KU Leuven, Leuven, Belgium
| | - Guy Bormans
- Laboratory for Radiopharmaceutical Research, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium; and
| | - Koen Van Laere
- Division of Nuclear Medicine, Department of Imaging and Pathology, University Hospitals Leuven, KU Leuven, Leuven, Belgium
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Van Weehaeghe D, Koole M, Schmidt ME, Deman S, Jacobs AH, Souche E, Serdons K, Sunaert S, Bormans G, Vandenberghe W, Van Laere K. [ 11C]JNJ54173717, a novel P2X7 receptor radioligand as marker for neuroinflammation: human biodistribution, dosimetry, brain kinetic modelling and quantification of brain P2X7 receptors in patients with Parkinson's disease and healthy volunteers. Eur J Nucl Med Mol Imaging 2019; 46:2051-2064. [PMID: 31243495 DOI: 10.1007/s00259-019-04369-6] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Accepted: 05/23/2019] [Indexed: 01/11/2023]
Abstract
PURPOSE The P2X7 receptor (P2X7R) is an ATP-gated ion channel predominantly expressed on activated microglia and is important in neurodegenerative diseases including Parkinson's disease (PD). In this first-in-human study, we investigated [11C]JNJ54173717 ([11C]JNJ717), a selective P2X7R tracer, in healthy volunteers (HV) and PD patients. Biodistribution, dosimetry, kinetic modelling and short-term test-retest variation (TRV), as well as possible genotype effects, were investigated. METHODS Biodistribution and radiation dosimetry studies were performed in three HV (mean age 30 ± 2 years, two women) using whole-body PET/CT. The most appropriate kinetic model was determined in 11 HV (mean age 62 ± 10 years, six women) and 10 PD patients (mean age 64 ± 8 years, three women; mean UPDRS motor score 21 ± 8) using 90-min dynamic simultaneous PET/MR scans. The total volume of distribution (VT) was calculated using a one-tissue and a two-tissue compartment model (1TCM, 2TCM) and Logan graphical analysis, and its time stability was assessed. Seven subjects underwent retest scans (mean age 60 ± 13 years, four HV, one woman). A group analysis was performed to compare PD patients and HV. Finally, 13 exons of P2X7R were genotyped in all subjects included in the second part of the study. RESULTS The mean effective dose was 4.47 ± 0.32 μSv/MBq, with the highest absorbed doses to the gallbladder, liver and small intestine. A reversible 2TCM was the most appropriate kinetic model with relatively homogeneous VT values in the grey and white matter. Average VT values were 3.4 ± 0.8 in HV and 3.3 ± 0.7 in PD patients, with no significant difference between the groups, but a possible genotype effect (rs3751143) was identified which can affect VT. Average TRV was 10-15%. The stability of VT over time allowed a reduction in scan time to 70 min. CONCLUSION [11C]JNJ717 is safe and suitable for quantifying P2X7R expression in human brain. In this pilot study, no significant differences in P2X7R binding were found between HV and PD patients. The results also suggest that genotype effects need to be incorporated in future P2X7R PET analyses.
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Affiliation(s)
- Donatienne Van Weehaeghe
- Division of Nuclear Medicine and Molecular Imaging, University Hospitals of Leuven and KU Leuven, Leuven, Belgium.
| | - Michel Koole
- Division of Nuclear Medicine and Molecular Imaging, University Hospitals of Leuven and KU Leuven, Leuven, Belgium
| | - Mark E Schmidt
- Janssen Research and Development: Beerse, Beerse, Belgium
| | - Stephanie Deman
- Genomics Core, UZ Leuven, Leuven, Belgium
- Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - Andreas H Jacobs
- European Institute for Molecular Imaging (EIMI), Westfalian Wilhelms University (WWU) Münster, Münster, Germany
- Department of Geriatrics and Neurology, Johanniter Hospital Bonn, Bonn, Germany
| | - Erika Souche
- Genomics Core, UZ Leuven, Leuven, Belgium
- Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - Kim Serdons
- Division of Nuclear Medicine and Molecular Imaging, University Hospitals of Leuven and KU Leuven, Leuven, Belgium
| | - Stefan Sunaert
- Department of Radiology, University Hospitals Leuven, Gasthuisberg, UZ, Leuven, Belgium
| | - Guy Bormans
- Laboratory for Radiopharmaceutical Research, KU Leuven, Leuven, Belgium
| | - Wim Vandenberghe
- Department of Neurosciences, KU Leuven, Leuven, Belgium
- Department of Neurology, University Hospitals Leuven, Leuven, Belgium
| | - Koen Van Laere
- Division of Nuclear Medicine and Molecular Imaging, University Hospitals of Leuven and KU Leuven, Leuven, Belgium
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Crabbé M, Van der Perren A, Bollaerts I, Kounelis S, Baekelandt V, Bormans G, Casteels C, Moons L, Van Laere K. Increased P2X7 Receptor Binding Is Associated With Neuroinflammation in Acute but Not Chronic Rodent Models for Parkinson's Disease. Front Neurosci 2019; 13:799. [PMID: 31417352 PMCID: PMC6684733 DOI: 10.3389/fnins.2019.00799] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Accepted: 07/17/2019] [Indexed: 12/26/2022] Open
Abstract
The purinergic P2X7 receptor is a key mediator in (neuro)inflammation, a process that is associated with neurodegeneration and excitotoxicity in Parkinson’s disease (PD). Recently, P2X7 imaging has become possible with [11C]JNJ-(54173)717. We investigated P2X7 availability, in comparison with availability of the translocator protein (TSPO), in two well-characterized rat models of PD using in vitro autoradiography at multiple time points throughout the disease progression. Rats received either a unilateral injection with 6-hydroxydopamine (6-OHDA) in the striatum, or with recombinant adeno-associated viral vector overexpressing human A53T alpha-synuclein (α-SYN) in the substantia nigra. Transverse cryosections were incubated with [11C]JNJ-717 for P2X7 or [18F]DPA-714 for TSPO. [11C]JNJ-717 binding ratios were transiently elevated in the striatum of 6-OHDA rats at day 14–28 post-injection, with peak P2X7 binding at day 14. This largely coincided with the time course of striatal [18F]DPA-714 binding which was elevated at day 7–21, with peak TSPO binding at day 7. Increased P2X7 availability co-localized with microglial, but not astrocyte or neuronal markers. In the chronic α-SYN model, no significant differences were found in P2X7 binding, although in vitro TSPO overexpression was reported previously. This first study showed an increased P2X7 availability in the acute PD model in a time window corresponding with elevated TSPO binding and motor behavior changes. In contrast, the dynamics of TSPO and P2X7 were divergent in the chronic α-SYN model where no P2X7 changes were detectable. Overall, extended P2X7 phenotyping is warranted prior to implementation of P2X7 imaging for monitoring of neuroinflammation.
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Affiliation(s)
- Melissa Crabbé
- Nuclear Medicine and Molecular Imaging, Department of Imaging and Pathology, University Hospital Leuven, KU Leuven, Leuven, Belgium.,Molecular Small Animal Imaging Center, Department of Imaging and Pathology, KU Leuven, Leuven, Belgium
| | - Anke Van der Perren
- Laboratory for Neurobiology and Gene therapy, Department of Neurosciences, KU Leuven, Leuven, Belgium.,Leuven Viral Vector Core, KU Leuven, Leuven, Belgium
| | - Ilse Bollaerts
- Laboratory of Neuronal Circuit Development and Regeneration, Department of Biology, KU Leuven, Leuven, Belgium
| | - Savannah Kounelis
- Nuclear Medicine and Molecular Imaging, Department of Imaging and Pathology, University Hospital Leuven, KU Leuven, Leuven, Belgium.,Molecular Small Animal Imaging Center, Department of Imaging and Pathology, KU Leuven, Leuven, Belgium
| | - Veerle Baekelandt
- Laboratory for Neurobiology and Gene therapy, Department of Neurosciences, KU Leuven, Leuven, Belgium.,Leuven Viral Vector Core, KU Leuven, Leuven, Belgium.,Leuven Brain Institute, KU Leuven, Leuven, Belgium
| | - Guy Bormans
- Molecular Small Animal Imaging Center, Department of Imaging and Pathology, KU Leuven, Leuven, Belgium.,Radiopharmaceutical Research, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium
| | - Cindy Casteels
- Nuclear Medicine and Molecular Imaging, Department of Imaging and Pathology, University Hospital Leuven, KU Leuven, Leuven, Belgium.,Molecular Small Animal Imaging Center, Department of Imaging and Pathology, KU Leuven, Leuven, Belgium
| | - Lieve Moons
- Laboratory of Neuronal Circuit Development and Regeneration, Department of Biology, KU Leuven, Leuven, Belgium.,Leuven Brain Institute, KU Leuven, Leuven, Belgium
| | - Koen Van Laere
- Nuclear Medicine and Molecular Imaging, Department of Imaging and Pathology, University Hospital Leuven, KU Leuven, Leuven, Belgium.,Molecular Small Animal Imaging Center, Department of Imaging and Pathology, KU Leuven, Leuven, Belgium
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Vermeulen K, Vandamme M, Bormans G, Cleeren F. Design and Challenges of Radiopharmaceuticals. Semin Nucl Med 2019; 49:339-356. [PMID: 31470930 DOI: 10.1053/j.semnuclmed.2019.07.001] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
This review describes general concepts with regard to radiopharmaceuticals for diagnostic or therapeutic applications that help to understand the specific challenges encountered during the design, (radio)synthesis, in vitro and in vivo evaluation and clinical translation of novel radiopharmaceuticals. The design of a radiopharmaceutical requires upfront decisions with regard to combining a suitable vector molecule with an appropriate radionuclide, considering the type and location of the molecular target, the desired application, and the time constraints imposed by the relatively short half-life of radionuclides. Well-designed in vitro and in vivo experiments allow nonclinical validation of radiotracers. Ultimately, in combination with a limited toxicology package, the radiotracer becomes a radiopharmaceutical for clinical evaluation, produced in compliance with regulatory requirements for medicines for intravenous (IV) injection.
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Affiliation(s)
- Koen Vermeulen
- Laboratory for Radiopharmaceutical Research, Department of Pharmaceutical and Pharmacological Sciences, University of Leuven, Leuven, Belgium
| | - Mathilde Vandamme
- Laboratory for Radiopharmaceutical Research, Department of Pharmaceutical and Pharmacological Sciences, University of Leuven, Leuven, Belgium
| | - Guy Bormans
- Laboratory for Radiopharmaceutical Research, Department of Pharmaceutical and Pharmacological Sciences, University of Leuven, Leuven, Belgium.
| | - Frederik Cleeren
- Laboratory for Radiopharmaceutical Research, Department of Pharmaceutical and Pharmacological Sciences, University of Leuven, Leuven, Belgium
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40
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Gao M, Wang M, Meyer JA, Territo PR, Hutchins GD, Zarrinmayeh H, Zheng QH. Synthesis and in vitro biological evaluation of new P2X7R radioligands [11C]halo-GSK1482160 analogs. Bioorg Med Chem Lett 2019; 29:1476-1480. [DOI: 10.1016/j.bmcl.2019.04.018] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Revised: 04/08/2019] [Accepted: 04/10/2019] [Indexed: 02/07/2023]
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41
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Illes P, Rubini P, Huang L, Tang Y. The P2X7 receptor: a new therapeutic target in Alzheimer’s disease. Expert Opin Ther Targets 2019; 23:165-176. [DOI: 10.1080/14728222.2019.1575811] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Peter Illes
- Rudolf-Boehm-Institut für Pharmakologie und Toxikologie, Universität Leipzig, Leipzig, Germany
- Acupuncture and Tuina School, Chengdu University of TCM, Chengdu, China
| | - Patrizia Rubini
- Acupuncture and Tuina School, Chengdu University of TCM, Chengdu, China
| | - Lumei Huang
- Acupuncture and Tuina School, Chengdu University of TCM, Chengdu, China
| | - Yong Tang
- Acupuncture and Tuina School, Chengdu University of TCM, Chengdu, China
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Kolb HC, Barret O, Bhattacharya A, Chen G, Constantinescu C, Huang C, Letavic M, Tamagnan G, Xia CA, Zhang W, Szardenings AK. Preclinical Evaluation and Nonhuman Primate Receptor Occupancy Study of 18F-JNJ-64413739, a PET Radioligand for P2X7 Receptors. J Nucl Med 2019; 60:1154-1159. [PMID: 30733317 DOI: 10.2967/jnumed.118.212696] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 01/01/2019] [Indexed: 12/24/2022] Open
Abstract
The P2X7 receptor is an adenosine triphosphate-gated ion channel, which is abundantly expressed in glial cells within the central nervous system and in the periphery. P2X7 receptor activation leads to the release of the proinflammatory cytokine IL-1β in the brain, and antagonism of the P2X7 receptor is a novel therapeutic strategy to dampen adenosine triphosphate-dependent IL-1β signaling. PET ligands for the P2X7 receptor will not only be valuable to assess central target engagement of drug candidates but also hold promise as surrogate markers of central neuroinflammation. Herein we describe the in vitro and in vivo evaluation of 18F-JNJ-64413739, an 18F-labeled PET ligand for imaging the P2X7 receptor in the brain. Methods: P2X7 receptor affinity and specificity, pharmacokinetics, metabolic stability, blood-brain barrier permeability, and off-target binding of JNJ-64413739 were evaluated in a series of in vitro, ex vivo, and in vivo assays. 18F-JNJ-64413739 was radiolabeled via a one-step nucleophilic aromatic substitution. The tracer was also studied in rhesus macaques, and PET images were analyzed with an arterial plasma input function-based Logan graphical analysis. Results: The potency (half-maximal inhibitory concentration) of the P2X7 receptor antagonist JNJ-64413739 is 1.0 ± 0.2 nM and 2.0 ± 0.6 nM at the recombinant human and rat P2X7 receptor, respectively, and the binding affinity is 2.7 nM (rat cortex binding assay) and 15.9 nM (human P2X7 receptor). In nonhuman primate PET imaging studies, dose-dependent receptor occupancy of JNJ-54175446 was observed in 2 rhesus monkeys. At a 0.1 mg/kg dose (intravenous) of JNJ-54175446, the receptor occupancy was calculated to be 17% by Logan graphical analysis, whereas a dose of 2.5 mg/kg yielded a receptor occupancy of 60%. Conclusion: The preclinical evaluation of 18F-JNJ-64413739 demonstrates that the tracer engages the P2X7 receptor. Reproducible and dose-dependent receptor occupancy studies with the P2X7 receptor antagonist JNJ-54175446 were obtained in rhesus monkeys. This novel PET tracer exhibits in vitro and in vivo characteristics suitable for imaging the P2X7 receptor in the brain and warrants further studies in humans.
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Affiliation(s)
- Hartmuth C Kolb
- Janssen Research and Development LLC, San Diego, California; and
| | | | | | - Gang Chen
- Janssen Research and Development LLC, San Diego, California; and
| | | | - Chaofeng Huang
- Janssen Research and Development LLC, San Diego, California; and
| | - Michael Letavic
- Janssen Research and Development LLC, San Diego, California; and
| | | | - Chunfang A Xia
- Janssen Research and Development LLC, San Diego, California; and
| | - Wei Zhang
- Janssen Research and Development LLC, San Diego, California; and
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43
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Fu Z, Lin Q, Hu B, Zhang Y, Chen W, Zhu J, Zhao Y, Choi HS, Shi H, Cheng D. P2X7 PET Radioligand 18F-PTTP for Differentiation of Lung Tumor from Inflammation. J Nucl Med 2019; 60:930-936. [PMID: 30655332 DOI: 10.2967/jnumed.118.222547] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Accepted: 12/10/2018] [Indexed: 12/28/2022] Open
Abstract
Site-specific imaging agents play a key role in tumor targeting, but only a few agents are currently available for inflammation targeting. Since the P2X7 receptor (P2X7R) is a promising molecular target for inflammation, we evaluated the potential value of the 18F-labeled tracer 18F-PTTP (5-{[2-Chloro-3-(trifluoromethyl)phenyl]carbonyl}-1-pyrimidin-2-yl-4,5,6,7-tetrahydro-1H-[1,2,3]triazolo[4,5-c]pyridin) for targeting P2X7Rs and thus differentiating inflammation from tumors. Methods: The radioligand 18F-PTTP was achieved by a 1-step 18F-trifluoromethylation reaction. The binding affinity of the ligand for P2X7R and its stability were evaluated in vitro. Blood pharmacokinetics tests and biodistribution studies were performed in vivo. Dynamic 18F-PTTP small-animal PET/CT imaging was performed for 60 min on A549 tumor-bearing mice and inflammation-model mice for targeting differentiation. Results: 18F-PTTP was afforded with decay-corrected radiochemical yields of 2.5%-7.0%, specific activity of 296-370 MBq/μmol, and radiochemical purity over 95%. 18F-PTTP showed excellent stability in 0.9% NaCl and 0.1% bovine serum albumin, good affinity to RAW264.7 cells, and rapid blood clearance in mice. In inflammation-model mice, uptake of 18F-PTTP peaked at 5 min after injection and kept at an imageable level till 30 min, whereas no significant radioactivity uptake was found in tumor grafts till 1 h after injection. The specificity of 18F-PTTP was verified by blocking studies and histologic analysis. Conclusion: The current study provides compelling data that 18F-PTTP is a novel radioligand targeting P2X7R and has potential to screen new drugs, quantify peripheral inflammation, and distinguish inflammation from certain solid tumors.
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Affiliation(s)
- Zhequan Fu
- Department of Nuclear Medicine, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Qingyu Lin
- Department of Nuclear Medicine, Zhongshan Hospital, Fudan University, Shanghai, China.,Shanghai Institute of Medical Imaging, Shanghai, China; and
| | - Bingxin Hu
- Department of Nuclear Medicine, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Yingying Zhang
- Department of Nuclear Medicine, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Weijia Chen
- Department of Nuclear Medicine, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Jing Zhu
- Department of Nuclear Medicine, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Yanzhao Zhao
- Department of Nuclear Medicine, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Hak Soo Choi
- Department of Radiology, Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts
| | - Hongcheng Shi
- Department of Nuclear Medicine, Zhongshan Hospital, Fudan University, Shanghai, China .,Shanghai Institute of Medical Imaging, Shanghai, China; and
| | - Dengfeng Cheng
- Department of Nuclear Medicine, Zhongshan Hospital, Fudan University, Shanghai, China .,Shanghai Institute of Medical Imaging, Shanghai, China; and
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Inhibitors of NF-κB and P2X7/NLRP3/Caspase 1 pathway in microglia: Novel therapeutic opportunities in neuroinflammation induced early-stage Alzheimer’s disease. J Neuroimmunol 2019; 326:62-74. [DOI: 10.1016/j.jneuroim.2018.11.010] [Citation(s) in RCA: 107] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Revised: 11/16/2018] [Accepted: 11/18/2018] [Indexed: 12/21/2022]
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45
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Development of brain PET imaging agents: Strategies for imaging neuroinflammation in Alzheimer's disease. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2019; 165:371-399. [DOI: 10.1016/bs.pmbts.2019.04.005] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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46
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Beckers L, Ory D, Geric I, Declercq L, Koole M, Kassiou M, Bormans G, Baes M. Increased Expression of Translocator Protein (TSPO) Marks Pro-inflammatory Microglia but Does Not Predict Neurodegeneration. Mol Imaging Biol 2018; 20:94-102. [PMID: 28695372 DOI: 10.1007/s11307-017-1099-1] [Citation(s) in RCA: 65] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
PURPOSE Activation of the innate immune system plays a significant role in pathologies of the central nervous system (CNS). In order to follow disease progression and evaluate effectiveness of potential treatments involved in neuroinflammation, it is important to track neuroinflammatory markers in vivo longitudinally. The translocator protein (TSPO) is used as a target to image neuroinflammation as its expression is upregulated in reactive glial cells during CNS pathologies. However, it remains unclear in which microglial phenotypes TSPO levels are upregulated, as microglia can display a plethora of activation states that can be protective or detrimental to the CNS. PROCEDURES We assessed the levels of TSPO transcripts in cultured microglia that were polarized into pro- and anti-inflammatory states in vitro and in the brain of mice in which an anti-inflammatory environment was induced in vivo. In addition, we used a mouse model of peroxisomal multifunctional protein-2 (MFP2) deficiency that exhibits widespread neuroinflammation despite no neuronal loss and monitored TSPO expression by immunohistochemistry and by imaging using the TSPO radiotracer [18F]DPA-714. RESULTS TSPO expression was selectively increased in so-called classically activated or M1 microglia but not in alternatively activated or M2 microglia in vitro. In agreement, TSPO transcript levels were not induced in an anti-inflammatory brain environment. We found that both transcript and protein levels of TSPO are significantly increased in the brain of Mfp2 -/- compared to those of the control mice and TSPO immunoreactivity colocalized predominantly with microglia in Mfp2 -/- brain. In vitro and ex vivo autoradiography in Mfp2 -/- mice using the TSPO radiotracer [18F]DPA-714 confirmed increased expression of TSPO. These data demonstrate that TSPO imaging reveals microgliosis in non-neurodegenerative brain pathologies. CONCLUSIONS We show that induced TSPO expression marks a pro-inflammatory brain environment that is not necessarily accompanied by neuronal loss.
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Affiliation(s)
- Lien Beckers
- Department of Pharmaceutical and Pharmacological Sciences, Laboratory for Cell Metabolism, KU Leuven - University of Leuven, Campus Gasthuisberg O/N2, Herestraat 49, 3000, Leuven, Belgium
| | - Dieter Ory
- Department of Pharmaceutical and Pharmacological Sciences, Laboratory for Radiopharmacy, KU Leuven - University of Leuven, Leuven, Belgium
| | - Ivana Geric
- Department of Pharmaceutical and Pharmacological Sciences, Laboratory for Cell Metabolism, KU Leuven - University of Leuven, Campus Gasthuisberg O/N2, Herestraat 49, 3000, Leuven, Belgium
| | - Lieven Declercq
- Department of Pharmaceutical and Pharmacological Sciences, Laboratory for Radiopharmacy, KU Leuven - University of Leuven, Leuven, Belgium
| | - Michel Koole
- Department of Nuclear Medicine and Molecular Imaging, KU Leuven- University of Leuven, Leuven, Belgium
| | - Michael Kassiou
- School of Chemistry, The University of Sydney, Sydney, NSW, 2006, Australia
| | - Guy Bormans
- Department of Pharmaceutical and Pharmacological Sciences, Laboratory for Radiopharmacy, KU Leuven - University of Leuven, Leuven, Belgium
| | - Myriam Baes
- Department of Pharmaceutical and Pharmacological Sciences, Laboratory for Cell Metabolism, KU Leuven - University of Leuven, Campus Gasthuisberg O/N2, Herestraat 49, 3000, Leuven, Belgium.
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Bhattacharya A, Lord B, Grigoleit JS, He Y, Fraser I, Campbell SN, Taylor N, Aluisio L, O’Connor JC, Papp M, Chrovian C, Carruthers N, Lovenberg TW, Letavic MA. Neuropsychopharmacology of JNJ-55308942: evaluation of a clinical candidate targeting P2X7 ion channels in animal models of neuroinflammation and anhedonia. Neuropsychopharmacology 2018; 43:2586-2596. [PMID: 30026598 PMCID: PMC6224414 DOI: 10.1038/s41386-018-0141-6] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Revised: 06/26/2018] [Accepted: 06/27/2018] [Indexed: 11/09/2022]
Abstract
Emerging data continues to point towards a relationship between neuroinflammation and neuropsychiatric disorders. ATP-induced activation of P2X7 results in IL-1β release causing neuroinflammation and microglial activation. This study describes the in-vitro and in-vivo neuropharmacology of a novel brain-penetrant P2X7 antagonist, JNJ-55308942, currently in clinical development. JNJ-55308942 is a high-affinity, selective, brain-penetrant (brain/plasma of 1) P2X7 functional antagonist. In human blood and in mouse blood and microglia, JNJ-55308942 attenuated IL-1β release in a potent and concentration-dependent manner. After oral dosing, the compound exhibited both dose and concentration-dependent occupancy of rat brain P2X7 with an ED50 of 0.07 mg/kg. The P2X7 antagonist (3 mg/kg, oral) blocked Bz-ATP-induced brain IL-1β release in conscious rats, demonstrating functional effects of target engagement in the brain. JNJ-55308942 (30 mg/kg, oral) attenuated LPS-induced microglial activation in mice, assessed at day 2 after a single systemic LPS injection (0.8 mg/kg, i.p.), suggesting a role for P2X7 in microglial activation. In a model of BCG-induced depression, JNJ-55308942 dosed orally (30 mg/kg), reversed the BCG-induced deficits of sucrose preference and social interaction, indicating for the first time a role of P2X7 in the BCG model of depression, probably due to the neuroinflammatory component induced by BCG inoculation. Finally, in a rat model of chronic stress induced sucrose intake deficit, JNJ-55308942 reversed the deficit with concurrent high P2X7 brain occupancy as measured by autoradiography. This body of data demonstrates that JNJ-55308942 is a potent P2X7 antagonist, engages the target in brain, modulates IL-1β release and microglial activation leading to efficacy in two models of anhedonia in rodents.
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Affiliation(s)
- Anindya Bhattacharya
- Janssen Research & Development, LLC. Neuroscience Therapeutic Area, San Diego, CA, 92131, USA.
| | - Brian Lord
- Janssen Research & Development, LLC. Neuroscience Therapeutic Area, San Diego, CA 92131 USA
| | | | - Yingbo He
- Janssen Research & Development, LLC. Neuroscience Therapeutic Area, San Diego, CA 92131 USA
| | - Ian Fraser
- Janssen Research & Development, LLC. Neuroscience Therapeutic Area, San Diego, CA 92131 USA
| | - Shannon N. Campbell
- Janssen Research & Development, LLC. Neuroscience Therapeutic Area, San Diego, CA 92131 USA
| | - Natalie Taylor
- Janssen Research & Development, LLC. Neuroscience Therapeutic Area, San Diego, CA 92131 USA
| | - Leah Aluisio
- Janssen Research & Development, LLC. Neuroscience Therapeutic Area, San Diego, CA 92131 USA
| | - Jason C. O’Connor
- 0000 0004 0617 9080grid.414059.dDepartment of Pharmacology, UT Health San Antonio, 7703 Floyd Curl Dr. and Audie L. Murphy VA Hospital, 7400 Merton Minter Blvd, San Antonio, TX 78229 USA
| | - Mariusz Papp
- 0000 0001 2227 8271grid.418903.7Institute of Pharmacology, Polish Academy of Sciences, 12 Smętna, Krakow, 31-343 Poland
| | - Christa Chrovian
- Janssen Research & Development, LLC. Neuroscience Therapeutic Area, San Diego, CA 92131 USA
| | - Nicholas Carruthers
- Janssen Research & Development, LLC. Neuroscience Therapeutic Area, San Diego, CA 92131 USA
| | - Timothy W. Lovenberg
- Janssen Research & Development, LLC. Neuroscience Therapeutic Area, San Diego, CA 92131 USA
| | - Michael A. Letavic
- Janssen Research & Development, LLC. Neuroscience Therapeutic Area, San Diego, CA 92131 USA
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Bhattacharya A, Jones DNC. Emerging role of the P2X7-NLRP3-IL1β pathway in mood disorders. Psychoneuroendocrinology 2018; 98:95-100. [PMID: 30121550 DOI: 10.1016/j.psyneuen.2018.08.015] [Citation(s) in RCA: 69] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Revised: 08/03/2018] [Accepted: 08/09/2018] [Indexed: 12/30/2022]
Abstract
The science of neuroimmunopsychiatry has evolved rapidly in the last few years with the hope of tackling the unmet need in mood disorders. This article focuses on an inflammatory pathway, highly conserved in myeloid cells that may play a role in neuroinflammatory disorders including depression. Within the brain tissue, microglia are the myeloid cells that express the P2X7 ion channel that is connected through the NLRP3 inflammasome complex leading to release of IL-1β and IL-18. We present, in the way of reviewing relevant literature, the preclinical data and scientific rationale supporting the role of the P2X7-NLRP3-IL-1β pathway in mood disorders. We also highlight recent advances in drug discovery and development of P2X7 small molecule antagonists and P2X7 PET ligands which provide optimism that clinical tools are availableto address critical proof-of-concept experiments in mood disorders.
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Affiliation(s)
- Anindya Bhattacharya
- Janssen Research & Development, Neuroscience Therapeutic Area, 3210 Merryfield Row, San Diego, CA 92121, United States.
| | - Declan N C Jones
- Neuroscience External Innovation, Johnson & Johnson Innovation Centre, One Chapel Place, London, W1G 0BG, United Kingdom
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Shen Z, Bao X, Wang R. Clinical PET Imaging of Microglial Activation: Implications for Microglial Therapeutics in Alzheimer's Disease. Front Aging Neurosci 2018; 10:314. [PMID: 30349474 PMCID: PMC6186779 DOI: 10.3389/fnagi.2018.00314] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Accepted: 09/19/2018] [Indexed: 12/19/2022] Open
Abstract
In addition to extracellular β-amyloid plaques and intracellular neurofibrillary tangles, neuroinflammation has been identified as a key pathological characteristic of Alzheimer's disease (AD). Once activated, neuroinflammatory cells called microglia acquire different activation phenotypes. At the early stage of AD, activated microglia are mainly dominated by the neuroprotective and anti-inflammatory M2 phenotype. Conversely, in the later stage of AD, the excessive activation of microglia is considered detrimental and pro-inflammatory, turning into the M1 phenotype. Therapeutic strategies targeting the modulation of microglia may regulate their specific phenotype. Fortunately, with the rapid development of in vivo imaging methodologies, visualization of microglial activation has been well-explored. In this review, we summarize the critical role of activated microglia during the pathogenesis of AD and current studies concerning imaging of microglial activation in AD patients. We explore the possibilities for identifying activated microglial phenotypes with imaging techniques and highlight promising therapies that regulate the microglial phenotype in AD mice.
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Affiliation(s)
- Zhiwei Shen
- Department of Neurosurgery, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China
| | - Xinjie Bao
- Department of Neurosurgery, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China
| | - Renzhi Wang
- Department of Neurosurgery, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China
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50
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Koole M, Schmidt ME, Hijzen A, Ravenstijn P, Vandermeulen C, Van Weehaeghe D, Serdons K, Celen S, Bormans G, Ceusters M, Zhang W, Van Nueten L, Kolb H, de Hoon J, Van Laere K. 18F-JNJ-64413739, a Novel PET Ligand for the P2X7 Ion Channel: Radiation Dosimetry, Kinetic Modeling, Test-Retest Variability, and Occupancy of the P2X7 Antagonist JNJ-54175446. J Nucl Med 2018; 60:683-690. [PMID: 30262518 DOI: 10.2967/jnumed.118.216747] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Accepted: 09/18/2018] [Indexed: 12/27/2022] Open
Abstract
The P2X7 receptor (P2X7R) is an adenosine triphosphate-gated ion channel that is predominantly expressed on microglial cells in the central nervous system. We report the clinical qualification of P2X7-specific PET ligand 18F-JNJ-64413739 in healthy volunteers, including dosimetry, kinetic modeling, test-retest variability, and blocking by the P2X7 antagonist JNJ-54175446. Methods: Whole-body dosimetry was performed in 3 healthy male subjects by consecutive whole-body PET/CT scanning, estimation of the normalized cumulated activity, and calculation of the effective dose using OLINDA (v1.1). Next, 5 healthy male subjects underwent a 120-min dynamic 18F-JNJ-64413739 PET/MRI scan with arterial blood sampling to determine the appropriate kinetic model. For this purpose, 1- and 2-tissue compartment models and Logan graphic analysis (LGA) were evaluated for estimating regional volumes of distribution (VT). PET/MRI scanning was repeated in 4 of these subjects to evaluate medium-term test-retest variability (interscan interval, 26-97 d). For the single-dose occupancy study, 8 healthy male subjects underwent baseline and postdose 18F-JNJ-64413739 PET/MRI scans 4-6 h after the administration of a single oral dose of JNJ-54175446 (dose range, 5-300 mg). P2X7 occupancies were estimated using a Lassen plot and regional baseline and postdose VT Results: The average (mean ± SD) effective dose was 22.0 ± 1.0 μSv/MBq. The 2-tissue compartment model was the most appropriate kinetic model, with LGA showing very similar results. Regional 2-tissue compartment model VT values were about 3 and were rather homogeneous across all brain regions, with slightly higher estimates for the thalamus, striatum, and brain stem. Between-subject VT variability was relatively high, with cortical VT showing an approximate 3-fold range across subjects. As for time stability, the acquisition time could be reduced to 90 min. The average regional test-retest variability values were 10.7% ± 2.2% for 2-tissue compartment model VT and 11.9% ± 2.2% for LGA VT P2X7 occupancy approached saturation for single doses of JNJ-54175446 higher than 50 mg, and no reference region could be identified. Conclusion: 18F-JNJ-64413739 is a suitable PET ligand for the quantification of P2X7R expression in the human brain. It can be used to provide insight into P2X7R expression in health and disease, to evaluate target engagement by P2X7 antagonists, and to guide dose selection.
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Affiliation(s)
- Michel Koole
- Division of Nuclear Medicine and Molecular Imaging, University Hospitals Leuven, Leuven, Belgium.,Department of Imaging and Pathology, KU Leuven, Leuven, Belgium
| | | | - Anja Hijzen
- Janssen Research and Development, Beerse, Belgium
| | | | - Corinne Vandermeulen
- Center for Clinical Pharmacology, University Hospitals Leuven, Leuven, Belgium; and
| | - Donatienne Van Weehaeghe
- Division of Nuclear Medicine and Molecular Imaging, University Hospitals Leuven, Leuven, Belgium
| | - Kim Serdons
- Division of Nuclear Medicine and Molecular Imaging, University Hospitals Leuven, Leuven, Belgium
| | - Sofie Celen
- Laboratory for Radiopharmaceutical Research, KU Leuven, Leuven, Belgium
| | - Guy Bormans
- Laboratory for Radiopharmaceutical Research, KU Leuven, Leuven, Belgium
| | | | - Wei Zhang
- Janssen Research and Development, Beerse, Belgium
| | | | | | - Jan de Hoon
- Center for Clinical Pharmacology, University Hospitals Leuven, Leuven, Belgium; and
| | - Koen Van Laere
- Division of Nuclear Medicine and Molecular Imaging, University Hospitals Leuven, Leuven, Belgium .,Department of Imaging and Pathology, KU Leuven, Leuven, Belgium
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