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Ford J, Ortalli S, Gouverneur V. The 18F-Difluoromethyl Group: Challenges, Impact and Outlook. Angew Chem Int Ed Engl 2024; 63:e202404957. [PMID: 38640422 DOI: 10.1002/anie.202404957] [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: 03/12/2024] [Revised: 04/18/2024] [Accepted: 04/19/2024] [Indexed: 04/21/2024]
Abstract
The difluoromethyl functionality has proven useful in drug discovery, as it can modulate the properties of bioactive molecules. For PET imaging, this structural motif has been largely underexploited in (pre)clinical radiotracers due to a lack of user-friendly radiosynthetic routes. This Minireview provides an overview of the challenges facing radiochemists and summarises the efforts made to date to access 18F-difluoromethyl-containing radiotracers. Two distinct approaches have prevailed, the first of which relies on 18F-fluorination. A second approach consists of a 18F-difluoromethylation process, which uses 18F-labelled reagents capable of releasing key reactive intermediates such as the [18F]CF2H radical or [18F]difluorocarbene. Finally, we provide an outlook for future directions in the radiosynthesis of [18F]CF2H compounds and their application in tracer radiosynthesis.
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Affiliation(s)
- Joseph Ford
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, 12 Mansfield Road, Oxford, OX1 3TA, United Kingdom
| | - Sebastiano Ortalli
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, 12 Mansfield Road, Oxford, OX1 3TA, United Kingdom
| | - Véronique Gouverneur
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, 12 Mansfield Road, Oxford, OX1 3TA, United Kingdom
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2
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Bonanno F, Saw RS, Bleher D, Papadopoulos I, Bowden GD, Bjerregaard-Andersen K, Windhorst AD, Pichler BJ, Herfert K, Maurer A. Advancing Parkinson's Disease Diagnostics: The Potential of Arylpyrazolethiazole Derivatives for Imaging α-Synuclein Aggregates. ACS OMEGA 2024; 9:24774-24788. [PMID: 38882134 PMCID: PMC11170759 DOI: 10.1021/acsomega.4c01301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/13/2024] [Revised: 04/24/2024] [Accepted: 05/15/2024] [Indexed: 06/18/2024]
Abstract
The development of positron emission tomography (PET) tracers capable of detecting α-synuclein (α-syn) aggregates in vivo would represent a breakthrough for advancing the understanding and enabling the early diagnosis of Parkinson's disease and related disorders. It also holds the potential to assess the efficacy of therapeutic interventions. However, this remains challenging due to different structures of α-syn aggregates, the need for selectivity over other structurally similar amyloid proteins, like amyloid-β (Aβ), which frequently coexist with α-syn pathology, and the low abundance of the target in the brain that requires the development of a high-affinity ligand. To develop a successful PET tracer for the central nervous system (CNS), stringent criteria in terms of polarity and molecular size must also be considered, as the tracer must penetrate the blood-brain barrier and have low nonspecific binding to brain tissue. Here, we report a series of arylpyrazolethiazole (APT) derivatives, rationally designed from a structure-activity relationship study centered on existing ligands for α-syn fibrils, with a particular focus on the selectivity toward α-syn fibrils and control of physicochemical properties suitable for a CNS PET tracer. In vitro competition binding assays performed against [3H]MODAG-001 using recombinant α-syn and Aβ1-42 fibrils revealed APT-13 with an inhibition constant of 27.8 ± 9.7 nM and a selectivity of more than 3.3 fold over Aβ. Radiolabeled [11C]APT-13 demonstrated excellent brain penetration in healthy mice with a peak standardized uptake value of 1.94 ± 0.29 and fast washout from the brain (t 1/2 = 9 ± 1 min). This study highlights the potential of APT-13 as a lead compound for developing PET tracers to detect α-syn aggregates in vivo.
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Affiliation(s)
- Federica Bonanno
- Werner Siemens Imaging Center, Department of Preclinical Imaging and Radiopharmacy, Eberhard Karls University Tübingen, Röntgenweg 13, Tübingen 72076, Germany
| | - Ran Sing Saw
- Werner Siemens Imaging Center, Department of Preclinical Imaging and Radiopharmacy, Eberhard Karls University Tübingen, Röntgenweg 13, Tübingen 72076, Germany
| | - Daniel Bleher
- Werner Siemens Imaging Center, Department of Preclinical Imaging and Radiopharmacy, Eberhard Karls University Tübingen, Röntgenweg 13, Tübingen 72076, Germany
| | - Ioannis Papadopoulos
- Werner Siemens Imaging Center, Department of Preclinical Imaging and Radiopharmacy, Eberhard Karls University Tübingen, Röntgenweg 13, Tübingen 72076, Germany
| | - Gregory D Bowden
- Werner Siemens Imaging Center, Department of Preclinical Imaging and Radiopharmacy, Eberhard Karls University Tübingen, Röntgenweg 13, Tübingen 72076, Germany
- Cluster of Excellence iFIT (EXC 2180) "Image-Guided and Functionally Instructed Tumor Therapies", Eberhard Karls University Tübingen, Röntgenweg 11, Tübingen 72076, Germany
| | | | - Albert D Windhorst
- Department of Radiology and Nuclear Medicine, Amsterdam UMC, Vrije Universiteit Amsterdam, De Boelelaan 1085c, 1081 HV Amsterdam, The Netherlands
| | - Bernd J Pichler
- Werner Siemens Imaging Center, Department of Preclinical Imaging and Radiopharmacy, Eberhard Karls University Tübingen, Röntgenweg 13, Tübingen 72076, Germany
- Cluster of Excellence iFIT (EXC 2180) "Image-Guided and Functionally Instructed Tumor Therapies", Eberhard Karls University Tübingen, Röntgenweg 11, Tübingen 72076, Germany
| | - Kristina Herfert
- Werner Siemens Imaging Center, Department of Preclinical Imaging and Radiopharmacy, Eberhard Karls University Tübingen, Röntgenweg 13, Tübingen 72076, Germany
| | - Andreas Maurer
- Werner Siemens Imaging Center, Department of Preclinical Imaging and Radiopharmacy, Eberhard Karls University Tübingen, Röntgenweg 13, Tübingen 72076, Germany
- Cluster of Excellence iFIT (EXC 2180) "Image-Guided and Functionally Instructed Tumor Therapies", Eberhard Karls University Tübingen, Röntgenweg 11, Tübingen 72076, Germany
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3
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Miyajima I, Yoshikawa A, Sahashi K, Seki C, Nagai Y, Watabe H, Shidahara M. DOCK-PET: database of CNS kinetic parameters in the healthy human brain for existing PET tracers. Ann Nucl Med 2024:10.1007/s12149-024-01947-z. [PMID: 38814564 DOI: 10.1007/s12149-024-01947-z] [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: 10/27/2023] [Accepted: 04/24/2024] [Indexed: 05/31/2024]
Abstract
PURPOSE Information about developed positron emission tomography (PET) tracers and obtained clinical PET images is publicly available in a database. However, findings regarding the kinetic parameters of PET tracers are yet to be summarized. Therefore, in this study, we created an open-access database of central nervous system (CNS) kinetic parameters in the healthy human brain for existing PET tracers (DOCK-PET). METHODS Our database includes information on the kinetic parameters and compounds of existing CNS-PET tracers. The kinetic parameter dataset comprises the analysis methods, VT, BPND, K parameters, relevant literature, and study details. The list of PET tracers and kinetic parameter information was compiled through keyword-based searches of PubMed and the Molecular Imaging and Contrast Agent Database (MICAD). The kinetic parameters obtained, including VT, BPND, and K parameters, were reorganized based on the defined brain anatomical regions. All data were rigorously double-checked before being summarized in Microsoft Excel and JavaScript Object Notation (JSON) formats. RESULTS Of the 247 PET tracers identified through searches using the PubMed and MICAD websites, the kinetic parameters of 120 PET tracers were available. Among the 120 PET tracers, compound structures with chemical and physical properties were obtained from the PubChem website or the ChemDraw software. Furthermore, the affinity information of the 104 PET tracers was gathered from PubChem or extensive literature surveys of the 120 PET tracers. CONCLUSIONS We developed a comprehensive open-access database, DOCK-PET, that includes both kinetic parameters of healthy humans and compound information for existing CNS-PET tracers.
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Affiliation(s)
- Itsuki Miyajima
- Department of Quantum Science and Energy Engineering, Graduate School of Engineering, Tohoku University, Sendai, Japan
| | - Ayano Yoshikawa
- Department of Quantum Science and Energy Engineering, Graduate School of Engineering, Tohoku University, Sendai, Japan
| | - Kyosei Sahashi
- Department of Quantum Science and Energy Engineering, Graduate School of Engineering, Tohoku University, Sendai, Japan
| | - Chie Seki
- Advanced Neuroimaging Center, Institute for Quantum Medical Science, National Institutes for Quantum Science and Technology, Chiba, Japan
| | - Yuji Nagai
- Advanced Neuroimaging Center, Institute for Quantum Medical Science, National Institutes for Quantum Science and Technology, Chiba, Japan
| | - Hiroshi Watabe
- Division of Radiation Protection and Nuclear Safety, Research Center for Accelerator and Radioisotope Science, Tohoku University, Sendai, Japan
| | - Miho Shidahara
- Department of Quantum Science and Energy Engineering, Graduate School of Engineering, Tohoku University, Sendai, Japan.
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4
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Eertink JJ, Bahce I, Waterton JC, Huisman MC, Boellaard R, Wunder A, Thiele A, Menke-van der Houven van Oordt CW. The development process of 'fit-for-purpose' imaging biomarkers to characterize the tumor microenvironment. Front Med (Lausanne) 2024; 11:1347267. [PMID: 38818386 PMCID: PMC11138661 DOI: 10.3389/fmed.2024.1347267] [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: 11/30/2023] [Accepted: 04/24/2024] [Indexed: 06/01/2024] Open
Abstract
Immune-based treatment approaches are successfully used for the treatment of patients with cancer. While such therapies can be highly effective, many patients fail to benefit. To provide optimal therapy choices and to predict treatment responses, reliable biomarkers for the assessment of immune features in patients with cancer are of significant importance. Biomarkers (BM) that enable a comprehensive and repeatable assessment of the tumor microenvironment (TME), the lymphoid system, and the dynamics induced by drug treatment can fill this gap. Medical imaging, notably positron emission tomography (PET) and magnetic resonance imaging (MRI), providing whole-body imaging BMs, might deliver such BMs. However, those imaging BMs must be well characterized as being 'fit for purpose' for the intended use. This review provides an overview of the key steps involved in the development of 'fit-for-purpose' imaging BMs applicable in drug development, with a specific focus on pharmacodynamic biomarkers for assessing the TME and its modulation by immunotherapy. The importance of the qualification of imaging BMs according to their context of use (COU) as defined by the Food and Drug Administration (FDA) and National Institutes of Health Biomarkers, EndpointS, and other Tools (BEST) glossary is highlighted. We elaborate on how an imaging BM qualification for a specific COU can be achieved.
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Affiliation(s)
- Jakoba J. Eertink
- Department of Medical Oncology, Amsterdam UMC Location Vrije Universiteit Amsterdam, Amsterdam, Netherlands
- Imaging and Biomarkers, Cancer Center Amsterdam, Amsterdam, Netherlands
| | - Idris Bahce
- Imaging and Biomarkers, Cancer Center Amsterdam, Amsterdam, Netherlands
- Department of Pulmonary Medicine, Amsterdam UMC Location Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - John C. Waterton
- Centre for Imaging Sciences, University of Manchester, Manchester, United Kingdom
| | - Marc C. Huisman
- Imaging and Biomarkers, Cancer Center Amsterdam, Amsterdam, Netherlands
- Department of Radiology and Nuclear Medicine, Amsterdam UMC Location Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - Ronald Boellaard
- Imaging and Biomarkers, Cancer Center Amsterdam, Amsterdam, Netherlands
- Department of Radiology and Nuclear Medicine, Amsterdam UMC Location Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - Andreas Wunder
- Department of Translational Medicine and Clinical Pharmacology, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach and der Riss, Germany
| | - Andrea Thiele
- Department of Translational Medicine and Clinical Pharmacology, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach and der Riss, Germany
| | - Catharina W. Menke-van der Houven van Oordt
- Department of Medical Oncology, Amsterdam UMC Location Vrije Universiteit Amsterdam, Amsterdam, Netherlands
- Imaging and Biomarkers, Cancer Center Amsterdam, Amsterdam, Netherlands
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5
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Lin D, Lechermann LM, Huestis MP, Marik J, Sap JBI. Light-Driven Radiochemistry with Fluorine-18, Carbon-11 and Zirconium-89. Angew Chem Int Ed Engl 2024; 63:e202317136. [PMID: 38135665 DOI: 10.1002/anie.202317136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2023] [Revised: 12/18/2023] [Accepted: 12/20/2023] [Indexed: 12/24/2023]
Abstract
This review discusses recent advances in light-driven radiochemistry for three key isotopes: fluorine-18, carbon-11, and zirconium-89, and their applications in positron emission tomography (PET). In the case of fluorine-18, the predominant approach involves the use of cyclotron-produced [18F]fluoride or reagents derived thereof. Light serves to activate either the substrate or the fluorine-18 labeled reagent. Advancements in carbon-11 photo-mediated radiochemistry have been leveraged for the radiolabeling of small molecules, achieving various transformations, including 11C-methylation, 11C-carboxylation, 11C-carbonylation, and 11C-cyanation. Contrastingly, zirconium-89 photo-mediated radiochemistry differs from fluorine-18 and carbon-11 approaches. In these cases, light facilitates a postlabeling click reaction, which has proven valuable for the labeling of large biomolecules such as monoclonal antibodies (mAbs). New technological developments, such as the incorporation of photoreactors in commercial radiosynthesizers, illustrate the commitment the field is making in embracing photochemistry. Taken together, these advances in photo-mediated radiochemistry enable radiochemists to apply new retrosynthetic strategies in accessing novel PET radiotracers.
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Affiliation(s)
- Daniel Lin
- Department of Translational Imaging, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA
- Current address: University of Southern California Department of Chemistry, Loker Hydrocarbon Research Institute, 837 Bloom Walk, Los Angeles, CA 90089, USA
| | - Laura M Lechermann
- Department of Translational Imaging, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Malcolm P Huestis
- Discovery Chemistry, Genentech, Inc., DNA Way, South San Francisco, CA 94080, USA
| | - Jan Marik
- Department of Translational Imaging, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA
- Discovery Chemistry, Genentech, Inc., DNA Way, South San Francisco, CA 94080, USA
| | - Jeroen B I Sap
- Department of Translational Imaging, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA
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6
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Yang T, Zheng W, Cheng X, Chen H, Jiang Z, Yu Z, Zhang L, Xie Y, Du L, Ge X, Zhang J, Yuan L, Liu Y, Wu Z. 18F-Labeled PET Tracers Specific for Adenosine A 2A Receptor: Design, Synthesis, and Biological Evaluation. ACS Chem Neurosci 2024; 15:1286-1297. [PMID: 38457777 DOI: 10.1021/acschemneuro.4c00066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/10/2024] Open
Abstract
By modifying the structures of targeted A2AR antagonists and tracers, novel compounds 3, 7a, 9, 12c, and BIBD-399 were designed and synthesized. In vitro inhibition experiments demonstrated that 3, 12c, and BIBD-399 have high affinity for A2AR. [18F]3 and [18F]BIBD-399 were successfully synthesized. In terms of biological distribution, the brain uptake of [18F]MNI-444 exhibits greater than that of [18F]3 and [18F]BIBD-399. PET imaging shows that [18F]3 is off-target in the brain, while [18F]BIBD-399 and [18F]MNI-444 can be specifically imaged in regions with high A2AR expression. Differently, [18F]BIBD-399 could quickly reach equilibrium in the targeted region within 10 min after administration, while [18F]MNI-444 shows a slowly increasing trend within 2 h of administration. [18F]BIBD-399 is mainly metabolized by the liver and kidney, and there is no obvious defluorination in vivo. Additional in vitro autoradiography showed that the striatal signals of [18F]BIBD-399 and [18F]MNI-444 were inhibited by the A2AR antagonist SCH442416 but not by the A1R antagonist DPCPX, demonstrating the high A2AR binding specificity of [18F]BIBD-399. Molecular docking further confirms the high affinity of MNI-444 and BIBD-399 for A2AR. Further tMCAo imaging showed that [18F]BIBD-399 can sensitively distinguish between infarcted and noninfarcted sides, a capability not observed with [18F]MNI-444. Given its pharmacokinetic properties and the ability to identify lesion regions, [18F]BIBD-399 has potential advantages in monitoring A2AR changes, meriting further clinical investigation.
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Affiliation(s)
- Tingyu Yang
- School of Pharmaceutical Science, Capital Medical University, Beijing 100069, China
| | - Wei Zheng
- Beijing Institute of Brain Disorders, Laboratory of Brain Disorders, Ministry of Science and Technology, Collaborative Innovation Center for Brain Disorders, Capital Medical University, Beijing 100069, China
| | - Xuebo Cheng
- Beijing Institute of Brain Disorders, Laboratory of Brain Disorders, Ministry of Science and Technology, Collaborative Innovation Center for Brain Disorders, Capital Medical University, Beijing 100069, China
| | - Hualong Chen
- Beijing Institute of Brain Disorders, Laboratory of Brain Disorders, Ministry of Science and Technology, Collaborative Innovation Center for Brain Disorders, Capital Medical University, Beijing 100069, China
| | - Zeng Jiang
- Beijing Institute of Brain Disorders, Laboratory of Brain Disorders, Ministry of Science and Technology, Collaborative Innovation Center for Brain Disorders, Capital Medical University, Beijing 100069, China
| | - Ziyue Yu
- Beijing Institute of Brain Disorders, Laboratory of Brain Disorders, Ministry of Science and Technology, Collaborative Innovation Center for Brain Disorders, Capital Medical University, Beijing 100069, China
| | - Lu Zhang
- Beijing Institute of Brain Disorders, Laboratory of Brain Disorders, Ministry of Science and Technology, Collaborative Innovation Center for Brain Disorders, Capital Medical University, Beijing 100069, China
| | - Yi Xie
- Beijing Institute of Brain Disorders, Laboratory of Brain Disorders, Ministry of Science and Technology, Collaborative Innovation Center for Brain Disorders, Capital Medical University, Beijing 100069, China
| | - Lianjie Du
- School of Pharmaceutical Science, Capital Medical University, Beijing 100069, China
| | - Xuan Ge
- Beijing Institute of Brain Disorders, Laboratory of Brain Disorders, Ministry of Science and Technology, Collaborative Innovation Center for Brain Disorders, Capital Medical University, Beijing 100069, China
| | - Jiahuai Zhang
- Center for Clinical Laboratory, Capital Medical University, Beijing 100069, China
| | - Leilei Yuan
- Department of Nuclear Medicine, Beijing Tiantan Hospital, Capital Medical University, Beijing 100070, China
| | - Yajing Liu
- School of Pharmaceutical Science, Capital Medical University, Beijing 100069, China
| | - Zehui Wu
- Beijing Institute of Brain Disorders, Laboratory of Brain Disorders, Ministry of Science and Technology, Collaborative Innovation Center for Brain Disorders, Capital Medical University, Beijing 100069, China
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7
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Saito H, Watanabe H, Ono M. Synthesis and biological evaluation of novel 18F-labeled 2,4-diaminopyrimidine derivatives for detection of ghrelin receptor in the brain. Bioorg Med Chem Lett 2024; 99:129625. [PMID: 38253227 DOI: 10.1016/j.bmcl.2024.129625] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Revised: 12/25/2023] [Accepted: 01/19/2024] [Indexed: 01/24/2024]
Abstract
The ghrelin receptor (GHSR) is known to regulate various physiological processes including appetite, food intake, and growth hormone release. Its expression is mainly observed in the brain, pancreas, stomach, and intestine. However, the functions of the receptor have not been fully elucidated. GHSR imaging with positron emission tomography (PET) is expected to further understanding of the functions and pathologies of the receptor. In this study, we newly designed and synthesized diaminopyrimidine derivatives ([18F]BPP-1 and [18F]BPP-2) and evaluated their utility as novel PET probes targeting GHSR. In in vitro competitive binding assays, the binding affinity of BPP-2 for GHSR (Ki = 274 nM) was comparable to that of the diaminopyimidine lead compound Abb8a (Ki = 109 nM). In a biodistribution study using normal mice, [18F]BPP-2 displayed low uptake in the brain and moderate uptake in the pancreas, but high radioactivity accumulation in bone was observed due to its defluorination in vivo. Taken together, although further improvement of the pharmacokinetics is needed, the diaminopyrimidine scaffold has potential for the development of useful GHSR-targeting PET probes.
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Affiliation(s)
- Haruka Saito
- Department of Patho-Functional Bioanalysis, Graduate School of Pharmaceutical Sciences, Kyoto University, 46-29 Yoshida Shimoadachi-cho, Sakyo-ku, Kyoto 606-8501, Japan
| | - Hiroyuki Watanabe
- Department of Patho-Functional Bioanalysis, Graduate School of Pharmaceutical Sciences, Kyoto University, 46-29 Yoshida Shimoadachi-cho, Sakyo-ku, Kyoto 606-8501, Japan.
| | - Masahiro Ono
- Department of Patho-Functional Bioanalysis, Graduate School of Pharmaceutical Sciences, Kyoto University, 46-29 Yoshida Shimoadachi-cho, Sakyo-ku, Kyoto 606-8501, Japan.
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8
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Cawthorne CJ, Volpe A, Fruhwirth GO. The Basics of Visualizing, Analyzing, and Reporting Preclinical PET/CT Imaging Data. Methods Mol Biol 2024; 2729:195-220. [PMID: 38006498 DOI: 10.1007/978-1-0716-3499-8_12] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2023]
Abstract
Positron emission tomography (PET) has transformed medical imaging, and while first developed and applied to the human setting, it has found widespread application at the preclinical level over the past two decades. Its strength is that it offers noninvasive 3D tomographic imaging in a quantitative manner at very high sensitivity. Paired with the right molecular probes, invaluable insights into physiology and pathophysiology have been accessible and therapeutic development has been enhanced through preclinical PET imaging. PET imaging is now often routinely combined with either computed tomography (CT) or magnetic resonance imaging (MRI) to provide additional anatomical context. All these developments were accompanied by the provision of ever more complex and powerful analysis software enabling users to visualize and quantify signals from PET imaging data. Aside from experimental complexities, there are also various pitfalls in PET image data analysis, which can negatively impact on reporting and reproducibility.Here, we provide a protocol intended to guide the inexperienced user through PET/CT data analysis. We describe the general principles and workflows required for PET/CT image data visualization and quantitative analysis using various software packages popular in the field. Moreover, we present recommendations for reporting of preclinical PET/CT data including examples of good and poor practice.
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Affiliation(s)
- Christopher J Cawthorne
- Nuclear Medicine and Molecular Imaging, Department of Imaging and Pathology, Katholieke Universiteit Leuven, Leuven, Belgium.
| | - Alessia Volpe
- Molecular Imaging Group, Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Gilbert O Fruhwirth
- Imaging Therapies and Cancer Group, Comprehensive Cancer Centre, School of Cancer and Pharmaceutical Sciences, King's College London, London, UK.
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9
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Howes OD, Bukala BR, Beck K. Schizophrenia: from neurochemistry to circuits, symptoms and treatments. Nat Rev Neurol 2024; 20:22-35. [PMID: 38110704 DOI: 10.1038/s41582-023-00904-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/08/2023] [Indexed: 12/20/2023]
Abstract
Schizophrenia is a leading cause of global disability. Current pharmacotherapy for the disease predominantly uses one mechanism - dopamine D2 receptor blockade - but often shows limited efficacy and poor tolerability. These limitations highlight the need to better understand the aetiology of the disease to aid the development of alternative therapeutic approaches. Here, we review the latest meta-analyses and other findings on the neurobiology of prodromal, first-episode and chronic schizophrenia, and the link to psychotic symptoms, focusing on imaging evidence from people with the disorder. This evidence demonstrates regionally specific neurotransmitter alterations, including higher glutamate and dopamine measures in the basal ganglia, and lower glutamate, dopamine and γ-aminobutyric acid (GABA) levels in cortical regions, particularly the frontal cortex, relative to healthy individuals. We consider how dysfunction in cortico-thalamo-striatal-midbrain circuits might alter brain information processing to underlie psychotic symptoms. Finally, we discuss the implications of these findings for developing new, mechanistically based treatments and precision medicine for psychotic symptoms, as well as negative and cognitive symptoms.
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Affiliation(s)
- Oliver D Howes
- Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK.
- Faculty of Medicine, Institute of Clinical Sciences, Imperial College London, London, UK.
| | - Bernard R Bukala
- Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
| | - Katherine Beck
- Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
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10
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Derdau V, Elmore CS, Hartung T, McKillican B, Mejuch T, Rosenbaum C, Wiebe C. The Future of (Radio)-Labeled Compounds in Research and Development within the Life Science Industry. Angew Chem Int Ed Engl 2023; 62:e202306019. [PMID: 37610759 DOI: 10.1002/anie.202306019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2023] [Revised: 08/23/2023] [Accepted: 08/23/2023] [Indexed: 08/24/2023]
Abstract
In this review the applications of isotopically labeled compounds are discussed and put into the context of their future impact in the life sciences. Especially discussing their use in the pharma and crop science industries to follow their fate in the environment, in vivo or in complex matrices to understand the potential harm of new chemical structures and to increase the safety of human society.
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Affiliation(s)
- Volker Derdau
- Sanofi-Aventis Deutschland GmbH, Research & Development, Integrated Drug Discovery, Isotope Chemistry, Industriepark Höchst, G876, 65926, Frankfurt am Main, Germany
| | - Charles S Elmore
- Early Chemical Development, Pharmaceutical Sciences, R&D, AstraZeneca, Mölndal, Sweden
| | - Thomas Hartung
- Pharma Research and Early Development, F. Hoffmann-La Roche Ltd, Basel, Switzerland
| | - Bruce McKillican
- Syngenta Crop Protection, LLC, North America Product Safety (retired), USA
| | - Tom Mejuch
- BASF SE, Agricultural Solutions, Ludwigshafen, Germany
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11
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Arjmand S, Bender D, Jakobsen S, Wegener G, Landau AM. Peering into the Brain's Estrogen Receptors: PET Tracers for Visualization of Nuclear and Extranuclear Estrogen Receptors in Brain Disorders. Biomolecules 2023; 13:1405. [PMID: 37759805 PMCID: PMC10526964 DOI: 10.3390/biom13091405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Revised: 09/12/2023] [Accepted: 09/15/2023] [Indexed: 09/29/2023] Open
Abstract
Estrogen receptors (ERs) play a multitude of roles in brain function and are implicated in various brain disorders. The use of positron emission tomography (PET) tracers for the visualization of ERs' intricate landscape has shown promise in oncology but remains limited in the context of brain disorders. Despite recent progress in the identification and development of more selective ligands for various ERs subtypes, further optimization is necessary to enable the reliable and efficient imaging of these receptors. In this perspective, we briefly touch upon the significance of estrogen signaling in the brain and raise the setbacks associated with the development of PET tracers for identification of specific ERs subtypes in the brain. We then propose avenues for developing efficient PET tracers to non-invasively study the dynamics of ERs in the brain, as well as neuropsychiatric diseases associated with their malfunction in a longitudinal manner. This perspective puts several potential candidates on the table and highlights the unmet needs and areas requiring further research to unlock the full potential of PET tracers for ERs imaging, ultimately aiding in deepening our understanding of ERs and forging new avenues for potential therapeutic strategies.
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Affiliation(s)
- Shokouh Arjmand
- Translational Neuropsychiatry Unit, Department of Clinical Medicine, Aarhus University, 8200 Aarhus, Denmark;
- Department of Nuclear Medicine and PET Center, Aarhus University Hospital, 8200 Aarhus, Denmark; (D.B.); (S.J.)
| | - Dirk Bender
- Department of Nuclear Medicine and PET Center, Aarhus University Hospital, 8200 Aarhus, Denmark; (D.B.); (S.J.)
| | - Steen Jakobsen
- Department of Nuclear Medicine and PET Center, Aarhus University Hospital, 8200 Aarhus, Denmark; (D.B.); (S.J.)
| | - Gregers Wegener
- Translational Neuropsychiatry Unit, Department of Clinical Medicine, Aarhus University, 8200 Aarhus, Denmark;
| | - Anne M. Landau
- Translational Neuropsychiatry Unit, Department of Clinical Medicine, Aarhus University, 8200 Aarhus, Denmark;
- Department of Nuclear Medicine and PET Center, Aarhus University Hospital, 8200 Aarhus, Denmark; (D.B.); (S.J.)
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12
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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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13
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Lo CH, Zeng J. Defective lysosomal acidification: a new prognostic marker and therapeutic target for neurodegenerative diseases. Transl Neurodegener 2023; 12:29. [PMID: 37287072 DOI: 10.1186/s40035-023-00362-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Accepted: 05/12/2023] [Indexed: 06/09/2023] Open
Abstract
Lysosomal acidification dysfunction has been implicated as a key driving factor in the pathogenesis of neurodegenerative diseases, including Alzheimer's disease and Parkinson's disease. Multiple genetic factors have been linked to lysosomal de-acidification through impairing the vacuolar-type ATPase and ion channels on the organelle membrane. Similar lysosomal abnormalities are also present in sporadic forms of neurodegeneration, although the underlying pathogenic mechanisms are unclear and remain to be investigated. Importantly, recent studies have revealed early occurrence of lysosomal acidification impairment before the onset of neurodegeneration and late-stage pathology. However, there is a lack of methods for organelle pH monitoring in vivo and a dearth of lysosome-acidifying therapeutic agents. Here, we summarize and present evidence for the notion of defective lysosomal acidification as an early indicator of neurodegeneration and urge the critical need for technological advancement in developing tools for lysosomal pH monitoring and detection both in vivo and for clinical applications. We further discuss current preclinical pharmacological agents that modulate lysosomal acidification, including small molecules and nanomedicine, and their potential clinical translation into lysosome-targeting therapies. Both timely detection of lysosomal dysfunction and development of therapeutics that restore lysosomal function represent paradigm shifts in targeting neurodegenerative diseases.
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Affiliation(s)
- Chih Hung Lo
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, 308232, Singapore.
| | - Jialiu Zeng
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, 308232, Singapore.
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14
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Howes OD, Onwordi EC. The synaptic hypothesis of schizophrenia version III: a master mechanism. Mol Psychiatry 2023; 28:1843-1856. [PMID: 37041418 PMCID: PMC10575788 DOI: 10.1038/s41380-023-02043-w] [Citation(s) in RCA: 23] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 03/16/2023] [Accepted: 03/20/2023] [Indexed: 04/13/2023]
Abstract
The synaptic hypothesis of schizophrenia has been highly influential. However, new approaches mean there has been a step-change in the evidence available, and some tenets of earlier versions are not supported by recent findings. Here, we review normal synaptic development and evidence from structural and functional imaging and post-mortem studies that this is abnormal in people at risk and with schizophrenia. We then consider the mechanism that could underlie synaptic changes and update the hypothesis. Genome-wide association studies have identified a number of schizophrenia risk variants converging on pathways regulating synaptic elimination, formation and plasticity, including complement factors and microglial-mediated synaptic pruning. Induced pluripotent stem cell studies have demonstrated that patient-derived neurons show pre- and post-synaptic deficits, synaptic signalling alterations, and elevated, complement-dependent elimination of synaptic structures compared to control-derived lines. Preclinical data show that environmental risk factors linked to schizophrenia, such as stress and immune activation, can lead to synapse loss. Longitudinal MRI studies in patients, including in the prodrome, show divergent trajectories in grey matter volume and cortical thickness compared to controls, and PET imaging shows in vivo evidence for lower synaptic density in patients with schizophrenia. Based on this evidence, we propose version III of the synaptic hypothesis. This is a multi-hit model, whereby genetic and/or environmental risk factors render synapses vulnerable to excessive glia-mediated elimination triggered by stress during later neurodevelopment. We propose the loss of synapses disrupts pyramidal neuron function in the cortex to contribute to negative and cognitive symptoms and disinhibits projections to mesostriatal regions to contribute to dopamine overactivity and psychosis. It accounts for the typical onset of schizophrenia in adolescence/early adulthood, its major risk factors, and symptoms, and identifies potential synaptic, microglial and immune targets for treatment.
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Affiliation(s)
- Oliver D Howes
- Faculty of Medicine, Institute of Clinical Sciences (ICS), Imperial College London, London, W12 0NN, UK.
- Psychiatric Imaging Group, Medical Research Council, London Institute of Medical Sciences, Hammersmith Hospital, London, W12 0NN, UK.
- Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, SE5 8AF, UK.
| | - Ellis Chika Onwordi
- Faculty of Medicine, Institute of Clinical Sciences (ICS), Imperial College London, London, W12 0NN, UK.
- Psychiatric Imaging Group, Medical Research Council, London Institute of Medical Sciences, Hammersmith Hospital, London, W12 0NN, UK.
- Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, SE5 8AF, UK.
- Centre for Psychiatry and Mental Health, Wolfson Institute of Population Health, Queen Mary University of London, London, E1 2AB, UK.
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15
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Watanabe H, Ide T, Ono M. Synthesis and Characterization of Novel Radioiodinated Triazole-Pyrolidine Derivative to Detect Orexin 2 Receptor in the Brain. Chem Pharm Bull (Tokyo) 2023; 71:234-239. [PMID: 36858529 DOI: 10.1248/cpb.c22-00770] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/03/2023]
Abstract
It is generally accepted that the orexin 2 receptor (OX2R) plays a critical role in the arousal-promoting function, and in vivo imaging of OX2R is expected to contribute to elucidation of orexin systems and the development of drugs to treat sleep disorder. In this study, we newly synthesized and characterized a radioiodinated triazole-pyrolidine derivative ([125I]TPI) to detect OX2R in the brain. In vitro studies using OX1R or OX2R expression cells showed selective binding of [125I]TPI to OX2R. In addition, in vitro autoradiography using rat brain sections showed high accumulation of radioactivity in the OX2R expression region. However, [125I]TPI showed low brain uptake in normal mice. These results suggest that [125I]TPI has a fundamental character to detect OX2R in vitro, but further structural modification to improve brain pharmacokinetics is required to use it for in vivo detection of OX2R.
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Affiliation(s)
- Hiroyuki Watanabe
- Department of Patho-Functional Bioanalysis, Graduate School of Pharmaceutical Sciences, Kyoto University
| | - Takuji Ide
- Department of Patho-Functional Bioanalysis, Graduate School of Pharmaceutical Sciences, Kyoto University
| | - Masahiro Ono
- Department of Patho-Functional Bioanalysis, Graduate School of Pharmaceutical Sciences, Kyoto University
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16
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Kong L, He Q, Li Q, Schreiber R, Kaitin KI, Shao L. Rapid progress in neuroimaging technologies fuels central nervous system translational medicine. Drug Discov Today 2023; 28:103485. [PMID: 36623797 DOI: 10.1016/j.drudis.2023.103485] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Revised: 12/12/2022] [Accepted: 01/03/2023] [Indexed: 01/09/2023]
Abstract
Central nervous system (CNS) drug discovery suffers from high attrition rates; translational neuroscience approaches aiming to reduce these high rates include the use of brain imaging technologies. However, there is a need to better understand what methods are being used and for what diseases and purposes. Our analysis of the literature found that magnetic resonance imaging (MRI), positron emission tomography (PET), and single-photon emission computed tomography (SPECT) were the neuroimaging techniques used most often in clinical trials for the most prevalent CNS diseases: Alzheimer's disease (AD), Parkinson's disease (PD), depression, and schizophrenia. Moreover, the number of initiated clinical trials using MRI, PET, and SPECT increased over the period 1981-2021. Such insights indicate that the significant increase in the use of neuroimaging studies could decrease the attrition of novel drug candidates in late clinical development.
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Affiliation(s)
- Linghui Kong
- School of Pharmacy, Fudan University, 826 Zhangheng Road, Zhangjiang Hi-tech Park, Pudong, Shanghai 201203, China
| | - Qian He
- School of Pharmacy, Fudan University, 826 Zhangheng Road, Zhangjiang Hi-tech Park, Pudong, Shanghai 201203, China
| | - Qiu Li
- Shanghai Center for iDrug Discovery & Development, 826 Zhangheng Road, Zhangjiang Hi-tech Park, Pudong, Shanghai 201203, China
| | - Rudy Schreiber
- Faculty of Psychology and Neuroscience, Section Neuropsychology & Psychopharmacology, Universiteitssingel 40, Maastricht University, PO Box 616, 6229 ER Maastricht, the Netherlands
| | - Kenneth I Kaitin
- Tufts Center for the Study of Drug Development (CSDD), Tufts University School of Medicine, Boston, MA, USA
| | - Liming Shao
- School of Pharmacy, Fudan University, 826 Zhangheng Road, Zhangjiang Hi-tech Park, Pudong, Shanghai 201203, China; Shanghai Center for iDrug Discovery & Development, 826 Zhangheng Road, Zhangjiang Hi-tech Park, Pudong, Shanghai 201203, China; State Key Laboratory of Medical Neurobiology, Fudan University, No. 138 Yixueyuan Road, Shanghai 200032, China.
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17
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Raval NR, Wetherill RR, Wiers CE, Dubroff JG, Hillmer AT. Positron Emission Tomography of Neuroimmune Responses in Humans: Insights and Intricacies. Semin Nucl Med 2023; 53:213-229. [PMID: 36270830 DOI: 10.1053/j.semnuclmed.2022.08.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Accepted: 08/30/2022] [Indexed: 11/06/2022]
Abstract
The brain's immune system plays a critical role in responding to immune challenges and maintaining homeostasis. However, dysregulated neuroimmune function contributes to neurodegenerative disease and neuropsychiatric conditions. In vivo positron emission tomography (PET) imaging of the neuroimmune system has facilitated a greater understanding of its physiology and the pathology of some neuropsychiatric conditions. This review presents an in-depth look at PET findings from human neuroimmune function studies, highlighting their importance in current neuropsychiatric research. Although the majority of human PET studies feature radiotracers targeting the translocator protein 18 kDa (TSPO), this review also considers studies with other neuroimmune targets, including monoamine oxidase B, cyclooxygenase-1 and cyclooxygenase-2, nitric oxide synthase, and the purinergic P2X7 receptor. Promising new targets, such as colony-stimulating factor 1, Sphingosine-1-phosphate receptor 1, and the purinergic P2Y12 receptor, are also discussed. The significance of validating neuroimmune targets and understanding their function and expression is emphasized in this review to better identify and interpret PET results.
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Affiliation(s)
- Nakul R Raval
- Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT; Yale PET Center, Yale University, New Haven, CT
| | - Reagan R Wetherill
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Corinde E Wiers
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA; Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Jacob G Dubroff
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Ansel T Hillmer
- Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT; Yale PET Center, Yale University, New Haven, CT; Department of Psychiatry, Yale University, New Haven, CT.
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18
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Singh P, Singh D, Srivastava P, Mishra G, Tiwari AK. Evaluation of advanced, pathophysiologic new targets for imaging of CNS. Drug Dev Res 2023; 84:484-513. [PMID: 36779375 DOI: 10.1002/ddr.22040] [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: 10/23/2022] [Revised: 12/12/2022] [Accepted: 12/31/2022] [Indexed: 02/14/2023]
Abstract
The inadequate information about the in vivo pathological, physiological, and neurological impairments, as well as the absence of in vivo tools for assessing brain penetrance and the efficiency of newly designed drugs, has hampered the development of new techniques for the treatment for variety of new central nervous system (CNS) diseases. The searching sites such as Science Direct and PubMed were used to find out the numerous distinct tracers across 16 CNS targets including tau, synaptic vesicle glycoprotein, the adenosine 2A receptor, the phosphodiesterase enzyme PDE10A, and the purinoceptor, among others. Among the most encouraging are [18 F]FIMX for mGluR imaging, [11 C]Martinostat for Histone deacetylase, [18 F]MNI-444 for adenosine 2A imaging, [11 C]ER176 for translocator protein, and [18 F]MK-6240 for tau imaging. We also reviewed the findings for each tracer's features and potential for application in CNS pathophysiology and therapeutic evaluation investigations, including target specificity, binding efficacy, and pharmacokinetic factors. This review aims to present a current evaluation of modern positron emission tomography tracers for CNS targets, with a focus on recent advances for targets that have newly emerged for imaging in humans.
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Affiliation(s)
- Priya Singh
- Department of Chemistry, Babasaheb Bhimrao Ambedkar University, Lucknow, Uttar Pradesh, India
| | - Deepika Singh
- Department of Chemistry, Babasaheb Bhimrao Ambedkar University, Lucknow, Uttar Pradesh, India
| | - Pooja Srivastava
- Division of Cyclotron and Radiopharmaceuticals Sciences, Institute of Nuclear Medicine and Allied Sciences, Delhi, India
| | - Gauri Mishra
- Department of Zoology, Swami Shraddhananad College, University of Delhi, Alipur, Delhi, India
| | - Anjani K Tiwari
- Department of Chemistry, Babasaheb Bhimrao Ambedkar University, Lucknow, Uttar Pradesh, India
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19
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Ni R. PET imaging in animal models of Parkinson's disease. Behav Brain Res 2023; 438:114174. [PMID: 36283568 DOI: 10.1016/j.bbr.2022.114174] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2022] [Revised: 09/20/2022] [Accepted: 09/27/2022] [Indexed: 12/05/2022]
Abstract
Alpha-synucleinopathies, such as Parkinson's disease, dementia with Lewy bodies and multiple system atrophy, are characterized by aberrant accumulation of alpha-synuclein and synaptic dysfunction leading to motor and cognitive deficits. Animal models of alpha-synucleinopathy have greatly facilitated the mechanistic understanding of the disease and the development of therapeutics. Various transgenic, alpha-synuclein fibril-injected, and toxin-injected animal models of Parkinson's disease and multiple system atrophy that recapitulate the disease pathology have been developed and widely used. Recent advances in positron emission tomography have allowed the noninvasive visualization of molecular alterations, underpinning behavioral dysfunctions in the brains of animal models and the longitudinal monitoring of treatment effects. Imaging studies in these disease animal models have employed multi-tracer PET designs to reveal dopaminergic deficits together with other molecular alterations. This review focuses on the development of new positron emission tomography tracers and studies of alpha-synuclein, synaptic vesicle glycoprotein 2A neurotransmitter receptor deficits such as dopaminergic receptor, dopaminergic transporter, serotonergic receptor, vesicular monoamine transporter 2, hypometabolism, neuroinflammation, mitochondrial dysfunction and leucine rich repeat kinase 2 in animal models of Parkinson's disease. The outstanding challenges and emerging applications are outlined, such as investigating the gut-brain-axis by using positron emission tomography in animal models, and provide a future outlook.
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Affiliation(s)
- Ruiqing Ni
- Institute for Regenerative Medicine, University of Zurich, Zurich, Switzerland; Institute for Biomedical Engineering, University of Zurich & ETH Zurich, Zurich, Switzerland.
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20
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Lopresti BJ, Royse SK, Mathis CA, Tollefson SA, Narendran R. Beyond monoamines: I. Novel targets and radiotracers for Positron emission tomography imaging in psychiatric disorders. J Neurochem 2023; 164:364-400. [PMID: 35536762 DOI: 10.1111/jnc.15615] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 04/05/2022] [Accepted: 04/06/2022] [Indexed: 10/18/2022]
Abstract
With the emergence of positron emission tomography (PET) in the late 1970s, psychiatry had access to a tool capable of non-invasive assessment of human brain function. Early applications in psychiatry focused on identifying characteristic brain blood flow and metabolic derangements using radiotracers such as [15 O]H2 O and [18 F]FDG. Despite the success of these techniques, it became apparent that more specific probes were needed to understand the neurochemical bases of psychiatric disorders. The first neurochemical PET imaging probes targeted sites of action of neuroleptic (dopamine D2 receptors) and psychoactive (serotonin receptors) drugs. Based on the centrality of monoamine dysfunction in psychiatric disorders and the measured success of monoamine-enhancing drugs in treating them, the next 30 years witnessed the development of an armamentarium of PET radiopharmaceuticals and imaging methodologies for studying monoamines. Continued development of monoamine-enhancing drugs over this time however was less successful, realizing only modest gains in efficacy and tolerability. As patent protection for many widely prescribed and profitable psychiatric drugs lapsed, drug development pipelines shifted away from monoamines in search of novel targets with the promises of improved efficacy, or abandoned altogether. Over this period, PET radiopharmaceutical development activities closely paralleled drug development priorities resulting in the development of new PET imaging agents for non-monoamine targets. Part one of this review will briefly survey novel PET imaging targets with relevance to the field of psychiatry, which include the metabotropic glutamate receptor type 5 (mGluR5), purinergic P2 X7 receptor, type 1 cannabinoid receptor (CB1 ), phosphodiesterase 10A (PDE10A), and describe radiotracers developed for these and other targets that have matured to human subject investigations. Current limitations of the targets and techniques will also be discussed.
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Affiliation(s)
- Brian J Lopresti
- Departments of Radiology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Sarah K Royse
- Departments of Radiology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Chester A Mathis
- Departments of Radiology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Savannah A Tollefson
- Departments of Radiology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Rajesh Narendran
- Departments of Radiology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA.,Departments of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
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21
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Howes OD, Cummings C, Chapman GE, Shatalina E. Neuroimaging in schizophrenia: an overview of findings and their implications for synaptic changes. Neuropsychopharmacology 2023; 48:151-167. [PMID: 36056106 PMCID: PMC9700830 DOI: 10.1038/s41386-022-01426-x] [Citation(s) in RCA: 31] [Impact Index Per Article: 31.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 08/03/2022] [Accepted: 08/05/2022] [Indexed: 11/09/2022]
Abstract
Over the last five decades, a large body of evidence has accrued for structural and metabolic brain alterations in schizophrenia. Here we provide an overview of these findings, focusing on measures that have traditionally been thought to reflect synaptic spine density or synaptic activity and that are relevant for understanding if there is lower synaptic density in the disorder. We conducted literature searches to identify meta-analyses or other relevant studies in patients with chronic or first-episode schizophrenia, or in people at high genetic or clinical risk for psychosis. We identified 18 meta-analyses including over 50,000 subjects in total, covering: structural MRI measures of gyrification index, grey matter volume, grey matter density and cortical thickness, neurite orientation dispersion and density imaging, PET imaging of regional glucose metabolism and magnetic resonance spectroscopy measures of N-acetylaspartate. We also review preclinical evidence on the relationship between ex vivo synaptic measures and structural MRI imaging, and PET imaging of synaptic protein 2A (SV2A). These studies show that schizophrenia is associated with lower grey matter volumes and cortical thickness, accelerated grey matter loss over time, abnormal gyrification patterns, and lower regional SV2A levels and metabolic markers in comparison to controls (effect sizes from ~ -0.11 to -1.0). Key regions affected include frontal, anterior cingulate and temporal cortices and the hippocampi. We identify several limitations for the interpretation of these findings in terms of understanding synaptic alterations. Nevertheless, taken with post-mortem findings, they suggest that schizophrenia is associated with lower synaptic density in some brain regions. However, there are several gaps in evidence, in particular whether SV2A findings generalise to other cohorts.
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Affiliation(s)
- Oliver D Howes
- Psychiatric Imaging Group, MRC London Institute of Medical Sciences, Hammersmith Hospital, Imperial College London, London, UK.
- Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK.
- South London and Maudsley NHS Foundation Trust, London, UK.
| | - Connor Cummings
- Psychiatric Imaging Group, MRC London Institute of Medical Sciences, Hammersmith Hospital, Imperial College London, London, UK
- Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
- South London and Maudsley NHS Foundation Trust, London, UK
- Clare Hall (College), University of Cambridge, Cambridge, UK
| | - George E Chapman
- Psychiatric Imaging Group, MRC London Institute of Medical Sciences, Hammersmith Hospital, Imperial College London, London, UK
- Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
- South London and Maudsley NHS Foundation Trust, London, UK
| | - Ekaterina Shatalina
- Psychiatric Imaging Group, MRC London Institute of Medical Sciences, Hammersmith Hospital, Imperial College London, London, UK
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22
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Meduri G, Guillemeau K, Daguinot C, Dounane O, Genet M, Ferrara L, Chambraud B, Baulieu EE, Giustiniani J. Concomitant Neuronal Tau Deposition and FKBP52 Decrease Is an Early Feature of Different Human and Experimental Tauopathies. J Alzheimers Dis 2023; 94:313-331. [PMID: 37248902 PMCID: PMC10357213 DOI: 10.3233/jad-230127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/22/2023] [Indexed: 05/31/2023]
Abstract
BACKGROUND Pathological tau proteins constitute neurofibrillary tangles that accumulate in tauopathies including Alzheimer's disease (AD), progressive supranuclear palsy (PSP), and familial frontotemporal lobar degeneration (FTLD-Tau). We previously showed that the FKBP52 immunophilin interacts functionally with tau and strongly decreases in AD brain neurons in correlation with tau deposition. We also reported that FKBP52 co-localizes with autophagy-lysosomal markers and an early pathological tau isoform in AD neurons, suggesting its involvement in autophagic tau clearance. OBJECTIVE Our objective was to evaluate if differences in neuronal FKBP52 expression levels and subcellular localization might be detected in AD, PSP, familial FTLD-Tau, and in the hTau-P301 S mouse model compared to controls. METHODS Cell by cell immunohistofluorescence analyses and quantification of FKBP52 were performed on postmortem brain samples of some human tauopathies and on hTau-P301 S mice spinal cords. RESULTS We describe a similar FKBP52 decrease and its localization with early pathological tau forms in the neuronal autophagy-lysosomal pathway in various tauopathies and hTau-P301 S mice. We find that FKBP52 decreases early during the pathologic process as it occurs in rare neurons with tau deposits in the marginally affected frontal cortex region of AD Braak IV brains and in the spinal cord of symptomless 1-month-old hTau-P301 S mice. CONCLUSION As FKBP52 plays a significant role in cellular signaling and conceivably in tau clearance, our data support the idea that the prevention of FKBP52 decrease or the restoration of its normal expression at early pathologic stages might represent a new potential therapeutic approach in tauopathies including AD, familial FTLD-Tau, and PSP.
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Affiliation(s)
- Geri Meduri
- Institut Professeur Baulieu, Kremlin-Bicêtre, France
| | | | | | - Omar Dounane
- Institut Professeur Baulieu, Kremlin-Bicêtre, France
| | - Melanie Genet
- Institut Professeur Baulieu, Kremlin-Bicêtre, France
| | - Luigi Ferrara
- Department of Biosciences, Biotechnology and Biopharmacology, UNIBA University, Bari, Italy
| | | | - Etienne Emile Baulieu
- Université Paris-Saclay, INSERM U1195, Kremlin-Bicêtre, France
- Institut Professeur Baulieu, Kremlin-Bicêtre, France
| | - Julien Giustiniani
- Université Paris-Saclay, INSERM U1195, Kremlin-Bicêtre, France
- Institut Professeur Baulieu, Kremlin-Bicêtre, France
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23
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Oxidation-Cyclisation of Biphenyl Thioethers to Dibenzothiophenium Salts for Ultrarapid 18F-Labelling of PET Tracers. Int J Mol Sci 2022; 23:ijms232415481. [PMID: 36555122 PMCID: PMC9779140 DOI: 10.3390/ijms232415481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Revised: 11/25/2022] [Accepted: 12/01/2022] [Indexed: 12/12/2022] Open
Abstract
18F-labelled radiotracers are in high demand and play an important role for diagnostic imaging with positron emission tomography (PET). Challenges associated with the synthesis of the labelling precursors and the incorporation of [18F]fluoride with practical activity yields at batch scale are the main limitations for the development of new 18F-PET tracers. Herein, we report a high-yielding and robust synthetic method to access naked dibenzothiophenium salt precursors of complex PET tracers and their labelling with [18F]fluoride. C-S cross-coupling of biphenyl-2-thioacetate with aryl halides followed by sequential oxidation-cyclisation of the corresponding thioethers gives dibenzothiophenium salts in good to excellent yields. Labelling of neutral and electron-deficient substrates with [18F]fluoride is ultrarapid and occurs under mild conditions (1 min at 90 °C) with high activity yields. The method enables facile synthesis of complex and sensitive radiotracers, as exemplified by radiofluorination of three clinically relevant PET tracers [18F]UCB-J, [18F]AldoView and [18F]FNDP, and can accelerate the development and clinical translation of new 18F-radiopharmaceuticals.
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24
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Edelmann MR. Radiolabelling small and biomolecules for tracking and monitoring. RSC Adv 2022; 12:32383-32400. [PMID: 36425706 PMCID: PMC9650631 DOI: 10.1039/d2ra06236d] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Accepted: 11/02/2022] [Indexed: 11/13/2022] Open
Abstract
Radiolabelling small molecules with beta-emitters has been intensively explored in the last decades and novel concepts for the introduction of radionuclides continue to be reported regularly. New catalysts that induce carbon/hydrogen activation are able to incorporate isotopes such as deuterium or tritium into small molecules. However, these established labelling approaches have limited applicability for nucleic acid-based drugs, therapeutic antibodies, or peptides, which are typical of the molecules now being investigated as novel therapeutic modalities. These target molecules are usually larger (significantly >1 kDa), mostly multiply charged, and often poorly soluble in organic solvents. However, in preclinical research they often require radiolabelling in order to track and monitor drug candidates in metabolism, biotransformation, or pharmacokinetic studies. Currently, the most established approach to introduce a tritium atom into an oligonucleotide is based on a multistep synthesis, which leads to a low specific activity with a high level of waste and high costs. The most common way of tritiating peptides is using appropriate precursors. The conjugation of a radiolabelled prosthetic compound to a functional group within a protein sequence is a commonly applied way to introduce a radionuclide or a fluorescent tag into large molecules. This review highlights the state-of-the-art in different radiolabelling approaches for oligonucleotides, peptides, and proteins, as well as a critical assessment of the impact of the label on the properties of the modified molecules. Furthermore, applications of radiolabelled antibodies in biodistribution studies of immune complexes and imaging of brain targets are reported.
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Affiliation(s)
- Martin R Edelmann
- Department of Pharmacy and Pharmacology, University of Bath Bath BA2 7AY UK
- Roche Pharma Research and Early Development, Roche Innovation Center Basel, Therapeutic Modalities, Small Molecule Research, Isotope Synthesis, F. Hoffmann-La Roche Ltd CH-4070 Basel Switzerland
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Koike T. Development of Specific PET Tracers for Central Nervous System Drug Targets. J SYN ORG CHEM JPN 2022. [DOI: 10.5059/yukigoseikyokaishi.80.1044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Tatsuki Koike
- Neuroscience Drug Discovery Unit, Research, Takeda Pharmaceutical Company Limited
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Wenzel B, Fritzsche SR, Toussaint M, Briel D, Kopka K, Brust P, Scheunemann M, Deuther-Conrad W. Radiosynthesis and Preclinical Evaluation of an 18F-Labeled Triazolopyridopyrazine-Based Inhibitor for Neuroimaging of the Phosphodiesterase 2A (PDE2A). Pharmaceuticals (Basel) 2022; 15:ph15101272. [PMID: 36297384 PMCID: PMC9609767 DOI: 10.3390/ph15101272] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Revised: 10/11/2022] [Accepted: 10/12/2022] [Indexed: 11/10/2022] Open
Abstract
The cyclic nucleotide phosphodiesterase 2A is an intracellular enzyme which hydrolyzes the secondary messengers cAMP and cGMP and therefore plays an important role in signaling cascades. A high expression in distinct brain areas as well as in cancer cells makes PDE2A an interesting therapeutic and diagnostic target for neurodegenerative and neuropsychiatric diseases as well as for cancer. Aiming at specific imaging of this enzyme in the brain with positron emission tomography (PET), a new triazolopyridopyrazine-based derivative (11) was identified as a potent PDE2A inhibitor (IC50, PDE2A = 1.99 nM; IC50, PDE10A ~2000 nM) and has been radiofluorinated for biological evaluation. In vitro autoradiographic studies revealed that [18F]11 binds with high affinity and excellent specificity towards PDE2A in the rat brain. For the PDE2A-rich region nucleus caudate and putamen an apparent KD value of 0.24 nM and an apparent Bmax value of 16 pmol/mg protein were estimated. In vivo PET-MR studies in rats showed a moderate brain uptake of [18F]11 with a highest standardized uptake value (SUV) of 0.97. However, no considerable enrichment in PDE2A-specific regions in comparison to a reference region was detectable (SUVcaudate putamen = 0.51 vs. SUVcerebellum = 0.40 at 15 min p.i.). Furthermore, metabolism studies revealed a considerable uptake of radiometabolites of [18F]11 in the brain (66% parent fraction at 30 min p.i.). Altogether, despite the low specificity and the blood−brain barrier crossing of radiometabolites observed in vivo, [18F]11 is a valuable imaging probe for the in vitro investigation of PDE2A in the brain and has potential as a lead compound for further development of a PDE2A-specific PET ligand for neuroimaging.
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Affiliation(s)
- Barbara Wenzel
- Department of Neuroradiopharmaceuticals, Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf, 04318 Leipzig, Germany
- Correspondence: (B.W.); (W.D.-C.)
| | - Stefan R. Fritzsche
- Institute for Drug Discovery, Faculty of Medicine, Leipzig University, 04103 Leipzig, Germany
| | - Magali Toussaint
- Department of Neuroradiopharmaceuticals, Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf, 04318 Leipzig, Germany
| | - Detlef Briel
- Institute for Drug Discovery, Faculty of Medicine, Leipzig University, 04103 Leipzig, Germany
| | - Klaus Kopka
- Department of Neuroradiopharmaceuticals, Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf, 04318 Leipzig, Germany
- Faculty of Chemistry and Food Chemistry, School of Science, Technical University Dresden, 01069 Dresden, Germany
| | - Peter Brust
- Department of Neuroradiopharmaceuticals, Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf, 04318 Leipzig, Germany
| | - Matthias Scheunemann
- Department of Neuroradiopharmaceuticals, Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf, 04318 Leipzig, Germany
| | - Winnie Deuther-Conrad
- Department of Neuroradiopharmaceuticals, Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf, 04318 Leipzig, Germany
- Correspondence: (B.W.); (W.D.-C.)
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Chen KC, Yang YK, Howes OD, Lee IH, Yeh TL, Chiu NT, Chen PS, David AS, Bramon E. Striatal dopamine D 2/3 receptors in medication-naïve schizophrenia: an [ 123I] IBZM SPECT study. Psychol Med 2022; 52:3251-3259. [PMID: 33682657 PMCID: PMC9693693 DOI: 10.1017/s0033291720005413] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 12/10/2020] [Accepted: 12/24/2020] [Indexed: 01/05/2023]
Abstract
BACKGROUND The hyper-function of the striatal dopamine system has been suggested to underlie key pathophysiological mechanisms in schizophrenia. Moreover, patients have been observed to present a significant elevation of dopamine receptor availability compared to healthy controls. Although it is difficult to measure dopamine levels directly in humans, neurochemical imaging techniques such as single-photon emission computed tomography (SPECT) provide indirect indices of in vivo dopamine synthesis and release, and putative synaptic levels. METHODS We focused on the role of dopamine postsynaptic regulation using [123I] iodobenzamide (IBZM) SPECT. We compared D2/3 receptor availability between 53 healthy controls and 21 medication-naive patients with recent-onset schizophrenia. RESULT The mean specific striatal binding showed no significant difference between patients and controls (estimated difference = 0.001; 95% CI -0.11 to 0.11; F = 0.00, df = 1, 69; p = 0.99). There was a highly significant effect of age whereby IBZM binding declined with advancing age [estimated change per decade of age = -0.01(binding ratio); 95% CI -0.01 to -0.004; F = 11.5, df = 1, 69; p = 0.001]. No significant correlations were found between the mean specific striatal binding and psychopathological or cognitive rating scores. CONCLUSIONS Medication-naïve patients with recent-onset schizophrenia have similar D2/3 receptor availability to healthy controls. We suggest that, rather than focusing exclusively on postsynaptic receptors, future treatments should target the presynaptic control of dopamine synthesis and release.
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Affiliation(s)
- Kao Chin Chen
- Department of Psychiatry, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Yen Kuang Yang
- Department of Psychiatry, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan
- Institute of Behavioral Medicine, College of Medicine, National Cheng Kung University, Tainan, Taiwan
- Department of Psychiatry, Tainan Hospital, Ministry of Health and Welfare, Tainan, Taiwan
| | - Oliver D. Howes
- Department of Psychosis Studies, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
- Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, London, UK
| | - I Hui Lee
- Department of Psychiatry, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Tzung Lieh Yeh
- Department of Psychiatry, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Nan Tsing Chiu
- Department of Nuclear Medicine, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Po See Chen
- Department of Psychiatry, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan
- Institute of Behavioral Medicine, College of Medicine, National Cheng Kung University, Tainan, Taiwan
- Department of Psychiatry, National Cheng Kung University, Dou-Liou Branch, Yunlin, Taiwan
| | - Anthony S. David
- Institute of Mental Health, University College London, London, UK
| | - Elvira Bramon
- Mental Health Neurosciences Research Department, Division of Psychiatry, University College London, London, UK
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Gao X, Gong K, Wang M, Xu B, Han J. Preparation of [ 18F]Alkenyl Fluorides Using No-Carrier-Added [ 18F]AgF via Silver-Mediated Direct Radiofluorination of Alkynes. Org Lett 2022; 24:6438-6442. [DOI: 10.1021/acs.orglett.2c02553] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Xinyan Gao
- Institute of Radiation Medicine, Fudan University, Xietu Road 2094, Shanghai 200032, China
| | - Kehao Gong
- Institute of Radiation Medicine, Fudan University, Xietu Road 2094, Shanghai 200032, China
| | - Mingwei Wang
- Department of Nuclear Medicine, Fudan University Shanghai Cancer Center, 270 Dong’An Road, Shanghai 200032, China
| | - Bo Xu
- College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, North Renmin Road 2999, Shanghai 201620, China
| | - Junbin Han
- Institute of Radiation Medicine, Fudan University, Xietu Road 2094, Shanghai 200032, China
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29
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Prange S, Theis H, Banwinkler M, van Eimeren T. Molecular Imaging in Parkinsonian Disorders—What’s New and Hot? Brain Sci 2022; 12:brainsci12091146. [PMID: 36138882 PMCID: PMC9496752 DOI: 10.3390/brainsci12091146] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Revised: 08/23/2022] [Accepted: 08/24/2022] [Indexed: 12/02/2022] Open
Abstract
Highlights Abstract Neurodegenerative parkinsonian disorders are characterized by a great diversity of clinical symptoms and underlying neuropathology, yet differential diagnosis during lifetime remains probabilistic. Molecular imaging is a powerful method to detect pathological changes in vivo on a cellular and molecular level with high specificity. Thereby, molecular imaging enables to investigate functional changes and pathological hallmarks in neurodegenerative disorders, thus allowing to better differentiate between different forms of degenerative parkinsonism, improve the accuracy of the clinical diagnosis and disentangle the pathophysiology of disease-related symptoms. The past decade led to significant progress in the field of molecular imaging, including the development of multiple new and promising radioactive tracers for single photon emission computed tomography (SPECT) and positron emission tomography (PET) as well as novel analytical methods. Here, we review the most recent advances in molecular imaging for the diagnosis, prognosis, and mechanistic understanding of parkinsonian disorders. First, advances in imaging of neurotransmission abnormalities, metabolism, synaptic density, inflammation, and pathological protein aggregation are reviewed, highlighting our renewed understanding regarding the multiplicity of neurodegenerative processes involved in parkinsonian disorders. Consequently, we review the role of molecular imaging in the context of disease-modifying interventions to follow neurodegeneration, ensure stratification, and target engagement in clinical trials.
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Affiliation(s)
- Stéphane Prange
- Multimodal Neuroimaging Group, Department of Nuclear Medicine, Faculty of Medicine, University Hospital of Cologne, University of Cologne, 50937 Cologne, Germany
- Institut des Sciences Cognitives Marc Jeannerod, CNRS, UMR 5229, Université de Lyon, 69675 Bron, France
- Correspondence: (S.P.); (T.v.E.); Tel.: +49-221-47882843 (T.v.E.)
| | - Hendrik Theis
- Multimodal Neuroimaging Group, Department of Nuclear Medicine, Faculty of Medicine, University Hospital of Cologne, University of Cologne, 50937 Cologne, Germany
- Department of Neurology, Faculty of Medicine, University Hospital of Cologne, University of Cologne, 50937 Cologne, Germany
| | - Magdalena Banwinkler
- Multimodal Neuroimaging Group, Department of Nuclear Medicine, Faculty of Medicine, University Hospital of Cologne, University of Cologne, 50937 Cologne, Germany
| | - Thilo van Eimeren
- Multimodal Neuroimaging Group, Department of Nuclear Medicine, Faculty of Medicine, University Hospital of Cologne, University of Cologne, 50937 Cologne, Germany
- Department of Neurology, Faculty of Medicine, University Hospital of Cologne, University of Cologne, 50937 Cologne, Germany
- Correspondence: (S.P.); (T.v.E.); Tel.: +49-221-47882843 (T.v.E.)
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30
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Sap JBI, Meyer CF, Ford J, Straathof NJW, Dürr AB, Lelos MJ, Paisey SJ, Mollner TA, Hell SM, Trabanco AA, Genicot C, Am Ende CW, Paton RS, Tredwell M, Gouverneur V. [ 18F]Difluorocarbene for positron emission tomography. Nature 2022; 606:102-108. [PMID: 35344982 DOI: 10.1038/s41586-022-04669-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Accepted: 03/21/2022] [Indexed: 11/09/2022]
Abstract
The advent of total-body positron emission tomography (PET) has vastly broadened the range of research and clinical applications of this powerful molecular imaging technology1. Such possibilities have accelerated progress in fluorine-18 (18F) radiochemistry with numerous methods available to 18F-label (hetero)arenes and alkanes2. However, access to 18F-difluoromethylated molecules in high molar activity is mostly an unsolved problem, despite the indispensability of the difluoromethyl group for pharmaceutical drug discovery3. Here we report a general solution by introducing carbene chemistry to the field of nuclear imaging with a [18F]difluorocarbene reagent capable of a myriad of 18F-difluoromethylation processes. In contrast to the tens of known difluorocarbene reagents, this 18F-reagent is carefully designed for facile accessibility, high molar activity and versatility. The issue of molar activity is solved using an assay examining the likelihood of isotopic dilution on variation of the electronics of the difluorocarbene precursor. Versatility is demonstrated with multiple [18F]difluorocarbene-based reactions including O-H, S-H and N-H insertions, and cross-couplings that harness the reactivity of ubiquitous functional groups such as (thio)phenols, N-heteroarenes and aryl boronic acids that are easy to install. The impact is illustrated with the labelling of highly complex and functionalized biologically relevant molecules and radiotracers.
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Affiliation(s)
- Jeroen B I Sap
- University of Oxford, Chemistry Research Laboratory, Oxford, UK
| | - Claudio F Meyer
- University of Oxford, Chemistry Research Laboratory, Oxford, UK
- Discovery Chemistry Janssen Research and Development, Toledo, Spain
| | - Joseph Ford
- University of Oxford, Chemistry Research Laboratory, Oxford, UK
| | | | | | | | - Stephen J Paisey
- Wales Research and Diagnostic PET Imaging Centre (PETIC), School of Medicine, Cardiff University, Cardiff, UK
| | - Tim A Mollner
- University of Oxford, Chemistry Research Laboratory, Oxford, UK
| | - Sandrine M Hell
- University of Oxford, Chemistry Research Laboratory, Oxford, UK
| | | | | | | | - Robert S Paton
- Department of Chemistry, Colorado State University, Fort Collins, CO, USA
| | - Matthew Tredwell
- Wales Research and Diagnostic PET Imaging Centre (PETIC), School of Medicine, Cardiff University, Cardiff, UK
- School of Chemistry, Cardiff University, Cardiff, UK
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Synthesis, Biological Evaluation, and Docking Studies of Antagonistic Hydroxylated Arecaidine Esters Targeting mAChRs. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27103173. [PMID: 35630651 PMCID: PMC9145622 DOI: 10.3390/molecules27103173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Revised: 05/05/2022] [Accepted: 05/14/2022] [Indexed: 11/17/2022]
Abstract
The muscarinic acetylcholine receptor family is a highly sought-after target in drug and molecular imaging discovery efforts aimed at neurological disorders. Hampered by the structural similarity of the five subtypes’ orthosteric binding pockets, these efforts largely failed to deliver subtype-selective ligands. Building on our recent successes with arecaidine-derived ligands targeting M1, herein we report the synthesis of a related series of 11 hydroxylated arecaidine esters. Their physicochemical property profiles, expressed in terms of their computationally calculated CNS MPO scores and HPLC-logD values, point towards blood–brain barrier permeability. By means of a competitive radioligand binding assay, the binding affinity values towards each of the individual human mAChR subtypes hM1–hM5 were determined. The most promising compound of this series 17b was shown to have a binding constant towards hM1 in the single-digit nanomolar region (5.5 nM). Similar to our previously reported arecaidine-derived esters, the entire series was shown to act as hM1R antagonists in a calcium flux assay. Overall, this study greatly expanded our understanding of this recurring scaffolds’ structure–activity relationship and will guide the development towards highly selective mAChRs ligands.
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Neelamegam R, Chaly T, Dileep Kumar J. Radiosynthesis and in vivo imaging of [11C]BTFP, a potent inhibitor of VEGFR2. RESULTS IN CHEMISTRY 2022. [DOI: 10.1016/j.rechem.2022.100381] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
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Crișan G, Moldovean-Cioroianu NS, Timaru DG, Andrieș G, Căinap C, Chiș V. Radiopharmaceuticals for PET and SPECT Imaging: A Literature Review over the Last Decade. Int J Mol Sci 2022; 23:ijms23095023. [PMID: 35563414 PMCID: PMC9103893 DOI: 10.3390/ijms23095023] [Citation(s) in RCA: 61] [Impact Index Per Article: 30.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2022] [Revised: 04/23/2022] [Accepted: 04/28/2022] [Indexed: 02/04/2023] Open
Abstract
Positron emission tomography (PET) uses radioactive tracers and enables the functional imaging of several metabolic processes, blood flow measurements, regional chemical composition, and/or chemical absorption. Depending on the targeted processes within the living organism, different tracers are used for various medical conditions, such as cancer, particular brain pathologies, cardiac events, and bone lesions, where the most commonly used tracers are radiolabeled with 18F (e.g., [18F]-FDG and NA [18F]). Oxygen-15 isotope is mostly involved in blood flow measurements, whereas a wide array of 11C-based compounds have also been developed for neuronal disorders according to the affected neuroreceptors, prostate cancer, and lung carcinomas. In contrast, the single-photon emission computed tomography (SPECT) technique uses gamma-emitting radioisotopes and can be used to diagnose strokes, seizures, bone illnesses, and infections by gauging the blood flow and radio distribution within tissues and organs. The radioisotopes typically used in SPECT imaging are iodine-123, technetium-99m, xenon-133, thallium-201, and indium-111. This systematic review article aims to clarify and disseminate the available scientific literature focused on PET/SPECT radiotracers and to provide an overview of the conducted research within the past decade, with an additional focus on the novel radiopharmaceuticals developed for medical imaging.
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Affiliation(s)
- George Crișan
- Faculty of Physics, Babeş-Bolyai University, Str. M. Kogălniceanu 1, 400084 Cluj-Napoca, Romania; (G.C.); (N.S.M.-C.); (D.-G.T.)
- Department of Nuclear Medicine, County Clinical Hospital, Clinicilor 3-5, 400006 Cluj-Napoca, Romania;
| | | | - Diana-Gabriela Timaru
- Faculty of Physics, Babeş-Bolyai University, Str. M. Kogălniceanu 1, 400084 Cluj-Napoca, Romania; (G.C.); (N.S.M.-C.); (D.-G.T.)
| | - Gabriel Andrieș
- Department of Nuclear Medicine, County Clinical Hospital, Clinicilor 3-5, 400006 Cluj-Napoca, Romania;
| | - Călin Căinap
- The Oncology Institute “Prof. Dr. Ion Chiricuţă”, Republicii 34-36, 400015 Cluj-Napoca, Romania;
| | - Vasile Chiș
- Faculty of Physics, Babeş-Bolyai University, Str. M. Kogălniceanu 1, 400084 Cluj-Napoca, Romania; (G.C.); (N.S.M.-C.); (D.-G.T.)
- Institute for Research, Development and Innovation in Applied Natural Sciences, Babeș-Bolyai University, Str. Fântânele 30, 400327 Cluj-Napoca, Romania
- Correspondence:
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Dassanayake P, Cui L, Finger E, Kewin M, Hadaway J, Soddu A, Jakoby B, Zuehlsdorf S, Lawrence KSS, Moran G, Anazodo UC. caliPER: A software for blood-free parametric Patlak mapping using PET/MRI input function. Neuroimage 2022; 256:119261. [PMID: 35500806 DOI: 10.1016/j.neuroimage.2022.119261] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Revised: 04/05/2022] [Accepted: 04/26/2022] [Indexed: 01/23/2023] Open
Abstract
Routine clinical use of absolute PET quantification techniques is limited by the need for serial arterial blood sampling for input function and more importantly by the lack of automated pharmacokinetic analysis tools that can be readily implemented in clinic with minimal effort. PET/MRI provides the ability for absolute quantification of PET probes without the need for serial arterial blood sampling using image-derived input functions (IDIFs). Here we introduce caliPER, a modular and scalable software for simplified pharmacokinetic modelling of PET probes with irreversible uptake or binding based on PET/MR IDIFs and Patlak Plot analysis. caliPER generates regional values or parametric maps of net influx rate (Ki) using reconstructed dynamic PET images and anatomical MRI aligned to PET for IDIF vessel delineation. We evaluated the performance of caliPER for blood-free region-based and pixel-wise Patlak analyses of [18F] FDG by comparing caliPER IDIF to serial arterial blood input functions and its application in imaging brain glucose hypometabolism in Frontotemporal dementia. IDIFs corrected for partial volume errors including spill-out and spill-in effects were similar to arterial blood input functions with a general bias of around 6-8%, even for arteries <5 mm. The Ki and cerebral metabolic rate of glucose estimated using caliPER IDIF were similar to estimates using arterial blood sampling (<2%) and within limits of whole brain values reported in literature. Overall, caliPER is a promising tool for irreversible PET tracer quantification and can simplify the ability to perform parametric analysis in clinical settings without the need for blood sampling.
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Affiliation(s)
- Praveen Dassanayake
- Lawson Health Research Institute, Ontario, London, Canada; Department of Medical Biophysics, Western University, Ontario, London, Canada
| | - Lumeng Cui
- Division of Biomedical Engineering, University of Saskatchewan, Saskatoon, Canada; Siemens Healthineers, Ontario, Mississauga, Oakville, Canada
| | - Elizabeth Finger
- Lawson Health Research Institute, Ontario, London, Canada; Department of Clinical Neurological Sciences, Schulich School of Medicine and Dentistry, Western University, Ontario, London, Canada
| | - Matthew Kewin
- Department of Medical Biophysics, Western University, Ontario, London, Canada
| | | | - Andrea Soddu
- Department of Physics and Astronomy, Western University, Ontario, London, Canada
| | - Bjoern Jakoby
- Siemens Healthcare GmbH, Healthineers, Erlangen, Germany
| | - Sven Zuehlsdorf
- Siemens Medical Solutions USA, Inc. Hoffman Estates, IL, USA
| | - Keith S St Lawrence
- Lawson Health Research Institute, Ontario, London, Canada; Department of Medical Biophysics, Western University, Ontario, London, Canada
| | - Gerald Moran
- Siemens Healthineers, Ontario, Mississauga, Oakville, Canada
| | - Udunna C Anazodo
- Lawson Health Research Institute, Ontario, London, Canada; Department of Medical Biophysics, Western University, Ontario, London, Canada; Department of Neurology and Neurosurgery, Montreal Neurological Institute, Montreal, Canada.
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Gündel D, Toussaint M, Lai TH, Deuther-Conrad W, Cumming P, Schröder S, Teodoro R, Moldovan RP, Pan-Montojo F, Sattler B, Kopka K, Sabri O, Brust P. Quantitation of the A2A Adenosine Receptor Density in the Striatum of Mice and Pigs with [18F]FLUDA by Positron Emission Tomography. Pharmaceuticals (Basel) 2022; 15:ph15050516. [PMID: 35631343 PMCID: PMC9146919 DOI: 10.3390/ph15050516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Revised: 04/14/2022] [Accepted: 04/19/2022] [Indexed: 12/10/2022] Open
Abstract
The cerebral expression of the A2A adenosine receptor (A2AAR) is altered in neurodegenerative diseases such as Parkinson’s (PD) and Huntington’s (HD) diseases, making these receptors an attractive diagnostic and therapeutic target. We aimed to further investigate the pharmacokinetic properties in the brain of our recently developed A2AAR–specific antagonist radiotracer [18F]FLUDA. For this purpose, we retrospectively analysed dynamic PET studies of healthy mice and rotenone–treated mice, and conducted dynamic PET studies with healthy pigs. We performed analysis of mouse brain time–activity curves to calculate the mean residence time (MRT) by non–compartmental analysis, and the binding potential (BPND) of [18F]FLUDA using the simplified reference tissue model (SRTM). For the pig studies, we performed a Logan graphical analysis to calculate the radiotracer distribution volume (VT) at baseline and under blocking conditions with tozadenant. The MRT of [18F]FLUDA in the striatum of mice was decreased by 30% after treatment with the A2AAR antagonist istradefylline. Mouse results showed the highest BPND (3.9 to 5.9) in the striatum. SRTM analysis showed a 20% lower A2AAR availability in the rotenone–treated mice compared to the control–aged group. Tozadenant treatment significantly decreased the VT (14.6 vs. 8.5 mL · g−1) and BPND values (1.3 vs. 0.3) in pig striatum. This study confirms the target specificity and a high BPND of [18F]FLUDA in the striatum. We conclude that [18F]FLUDA is a suitable tool for the non–invasive quantitation of altered A2AAR expression in neurodegenerative diseases such as PD and HD, by PET.
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Affiliation(s)
- Daniel Gündel
- Department of Neuroradiopharmaceuticals, Institute of Radiopharmaceutical Cancer Research, Helmholtz–Zentrum Dresden–Rossendorf, 04308 Leipzig, Germany; (M.T.); (T.H.L.); (W.D.-C.); (R.T.); (R.-P.M.); (K.K.); (P.B.)
- Correspondence: ; Tel.: +49-341-234179-4615
| | - Magali Toussaint
- Department of Neuroradiopharmaceuticals, Institute of Radiopharmaceutical Cancer Research, Helmholtz–Zentrum Dresden–Rossendorf, 04308 Leipzig, Germany; (M.T.); (T.H.L.); (W.D.-C.); (R.T.); (R.-P.M.); (K.K.); (P.B.)
| | - Thu Hang Lai
- Department of Neuroradiopharmaceuticals, Institute of Radiopharmaceutical Cancer Research, Helmholtz–Zentrum Dresden–Rossendorf, 04308 Leipzig, Germany; (M.T.); (T.H.L.); (W.D.-C.); (R.T.); (R.-P.M.); (K.K.); (P.B.)
- Department of Research and Development, ROTOP Pharmaka Ltd., 01328 Dresden, Germany;
| | - Winnie Deuther-Conrad
- Department of Neuroradiopharmaceuticals, Institute of Radiopharmaceutical Cancer Research, Helmholtz–Zentrum Dresden–Rossendorf, 04308 Leipzig, Germany; (M.T.); (T.H.L.); (W.D.-C.); (R.T.); (R.-P.M.); (K.K.); (P.B.)
| | - Paul Cumming
- Department of Nuclear Medicine, Bern University Hospital, 3010 Bern, Switzerland;
- School of Psychology and Counselling, Queensland University of Technology, Brisbane 4000, Australia
| | - Susann Schröder
- Department of Research and Development, ROTOP Pharmaka Ltd., 01328 Dresden, Germany;
| | - Rodrigo Teodoro
- Department of Neuroradiopharmaceuticals, Institute of Radiopharmaceutical Cancer Research, Helmholtz–Zentrum Dresden–Rossendorf, 04308 Leipzig, Germany; (M.T.); (T.H.L.); (W.D.-C.); (R.T.); (R.-P.M.); (K.K.); (P.B.)
- Department of Research and Development, Life Molecular Imaging GmbH, 13353 Berlin, Germany
| | - Rareş-Petru Moldovan
- Department of Neuroradiopharmaceuticals, Institute of Radiopharmaceutical Cancer Research, Helmholtz–Zentrum Dresden–Rossendorf, 04308 Leipzig, Germany; (M.T.); (T.H.L.); (W.D.-C.); (R.T.); (R.-P.M.); (K.K.); (P.B.)
| | - Francisco Pan-Montojo
- Department of Psychiatry, University Hospital Munich, Ludwig–Maximilians–Universität (LMU) Munich, 80336 Munich, Germany;
- Department of Neurology, University Hospital Munich, Ludwig–Maximilians–Universität (LMU) Munich, 81377 Munich, Germany
| | - Bernhard Sattler
- Department for Nuclear Medicine, University Hospital Leipzig, 04103 Leipzig, Germany; (B.S.); (O.S.)
| | - Klaus Kopka
- Department of Neuroradiopharmaceuticals, Institute of Radiopharmaceutical Cancer Research, Helmholtz–Zentrum Dresden–Rossendorf, 04308 Leipzig, Germany; (M.T.); (T.H.L.); (W.D.-C.); (R.T.); (R.-P.M.); (K.K.); (P.B.)
- Faculty of Chemistry and Food Chemistry, School of Science, TU Dresden, 01069 Dresden, Germany
| | - Osama Sabri
- Department for Nuclear Medicine, University Hospital Leipzig, 04103 Leipzig, Germany; (B.S.); (O.S.)
| | - Peter Brust
- Department of Neuroradiopharmaceuticals, Institute of Radiopharmaceutical Cancer Research, Helmholtz–Zentrum Dresden–Rossendorf, 04308 Leipzig, Germany; (M.T.); (T.H.L.); (W.D.-C.); (R.T.); (R.-P.M.); (K.K.); (P.B.)
- The Lübeck Institute of Experimental Dermatology, University Medical Center Schleswig–Holstein, 23562 Lübeck, Germany
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Tan Z, Wei H, Song X, Mai W, Yan J, Ye W, Ling X, Hou L, Zhang S, Yan S, Xu H, Wang L. Positron Emission Tomography in the Neuroimaging of Autism Spectrum Disorder: A Review. Front Neurosci 2022; 16:806876. [PMID: 35495051 PMCID: PMC9043810 DOI: 10.3389/fnins.2022.806876] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Accepted: 03/14/2022] [Indexed: 12/11/2022] Open
Abstract
Autism spectrum disorder (ASD) is a basket term for neurodevelopmental disorders characterized by marked impairments in social interactions, repetitive and stereotypical behaviors, and restricted interests and activities. Subtypes include (A) disorders with known genetic abnormalities including fragile X syndrome, Rett syndrome, and tuberous sclerosis and (B) idiopathic ASD, conditions with unknown etiologies. Positron emission tomography (PET) is a molecular imaging technology that can be utilized in vivo for dynamic and quantitative research, and is a valuable tool for exploring pathophysiological mechanisms, evaluating therapeutic efficacy, and accelerating drug development in ASD. Recently, several imaging studies on ASD have been published and physiological changes during ASD progression was disclosed by PET. This paper reviews the specific radioligands for PET imaging of critical biomarkers in ASD, and summarizes and discusses the similar and different discoveries in outcomes of previous studies. It is of great importance to identify general physiological changes in cerebral glucose metabolism, cerebral blood flow perfusion, abnormalities in neurotransmitter systems, and inflammation in the central nervous system in ASD, which may provide excellent points for further ASD research.
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Affiliation(s)
- Zhiqiang Tan
- Center of Cyclotron and PET Radiopharmaceuticals, Department of Nuclear Medicine and PET/CT-MRI Center, The First Affiliated Hospital of Jinan University, Guangzhou, China
| | - Huiyi Wei
- Center of Cyclotron and PET Radiopharmaceuticals, Department of Nuclear Medicine and PET/CT-MRI Center, The First Affiliated Hospital of Jinan University, Guangzhou, China
| | - Xiubao Song
- Department of Rehabilitation Medicine, The First Affiliated Hospital of Jinan University, Jinan University, Guangzhou, China
| | - Wangxiang Mai
- Department of Rehabilitation Medicine, The First Affiliated Hospital of Jinan University, Jinan University, Guangzhou, China
| | - Jiajian Yan
- Department of Rehabilitation Medicine, The First Affiliated Hospital of Jinan University, Jinan University, Guangzhou, China
| | - Weijian Ye
- Center of Cyclotron and PET Radiopharmaceuticals, Department of Nuclear Medicine and PET/CT-MRI Center, The First Affiliated Hospital of Jinan University, Guangzhou, China
| | - Xueying Ling
- Center of Cyclotron and PET Radiopharmaceuticals, Department of Nuclear Medicine and PET/CT-MRI Center, The First Affiliated Hospital of Jinan University, Guangzhou, China
| | - Lu Hou
- Center of Cyclotron and PET Radiopharmaceuticals, Department of Nuclear Medicine and PET/CT-MRI Center, The First Affiliated Hospital of Jinan University, Guangzhou, China
| | - Shaojuan Zhang
- Center of Cyclotron and PET Radiopharmaceuticals, Department of Nuclear Medicine and PET/CT-MRI Center, The First Affiliated Hospital of Jinan University, Guangzhou, China
| | - Sen Yan
- Guangdong-Hongkong-Macau Institute of CNS Regeneration, Ministry of Education CNS Regeneration Collaborative Joint Laboratory, Jinan University, Guangzhou, China
| | - Hao Xu
- Center of Cyclotron and PET Radiopharmaceuticals, Department of Nuclear Medicine and PET/CT-MRI Center, The First Affiliated Hospital of Jinan University, Guangzhou, China
- *Correspondence: Hao Xu,
| | - Lu Wang
- Center of Cyclotron and PET Radiopharmaceuticals, Department of Nuclear Medicine and PET/CT-MRI Center, The First Affiliated Hospital of Jinan University, Guangzhou, China
- Lu Wang,
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Li X, Tang Y, Yao Z, Hu S, Zhou H, Mo X, She C, Lu X, Huang G. FDG-PET/CT Assessment of the Cerebral Protective Effects of Hydrogen in Rabbits with Cardiac Arrest. Curr Med Imaging 2022; 18:977-985. [PMID: 35319386 DOI: 10.2174/1573405618666220321122214] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 12/20/2021] [Accepted: 02/08/2022] [Indexed: 11/22/2022]
Abstract
BACKGROUND Anatomical imaging methods and histological examinations have limited clinical value for early monitoring of brain function damage after cardiac arrest (CA) in vivo. OBJECTIVE We aimed to assess the cerebral protective effects of hydrogen in rabbits with CA by using fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT). METHODS Male rabbits were divided into the hydrogen-treated (n=6), control (n=6), and sham (n=3) groups. Maximum standardized uptake values (SUVmax) were measured by FDG-PET/CT at baseline and post-resuscitation. Blood Ubiquitin C-terminal hydrolase-L1 (UCH-L1) and neuron specific enolase (NSE) were measured before and after the operation. After surgical euthanasia, brain tissues were extracted for Nissl staining. RESULTS SUVmax values first decreased at 2 and 24 h after resuscitation before rising in the hydrogen-treated and control groups. SUVmax values in the frontal, occipital, and left temporal lobes and in the whole brain were significantly different between the hydrogen and control groups at 2 and 24 h post-resuscitation (P<0.05). The neurological deficit scores at 24 and 48 h were lower in the hydrogen-treated group (P<0.05). At 24 h, the serum UCH-L1 and NSE levels were increased in the hydrogen and control groups (P<0.05), but not in the sham group. At 48 and 72 h post-CA, the plasma UCH-L1 and NSE levels in the hydrogen and control groups gradually decreased. Neuronal damage was smaller in the hydrogen group compared with the control group at 72 h. CONCLUSION FDG-PET/CT could be used to monitor early cerebral damage, indicating a novel method for evaluating the protective effects of hydrogen on the brain after CA.
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Affiliation(s)
- Xiangmin Li
- Department of Emergency, Xiangya Hospital Central South University, Changsha 410008, Hunan, China
| | - Yongxiang Tang
- Department of Nuclear Medicine (PET Center), Xiangya Hospital Central South University, Changsha 410008, Hunan, China
| | - Zhengbin Yao
- Department of Emergency, Xiangya Hospital Central South University, Changsha 410008, Hunan, China
| | - Shuo Hu
- Department of Nuclear Medicine (PET Center), Xiangya Hospital Central South University, Changsha 410008, Hunan, China
- Key Laboratory of Biological Nanotechnology of National Health Commission, Xiangya Hospital, Central South University, Changsha, Hunan, China
- National Clinical Research Center for Geriatric Disorders (XIANGYA), Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Hui Zhou
- Department of Radiology, Xiangya Hospital Central South University, Changsha 410008, Hunan, China
| | - Xiaoye Mo
- Department of Emergency, Xiangya Hospital Central South University, Changsha 410008, Hunan, China
| | - Changshou She
- Department of Emergency, Xiangya Hospital Central South University, Changsha 410008, Hunan, China
| | - Xiaoqin Lu
- Department of Emergency, Xiangya Hospital Central South University, Changsha 410008, Hunan, China
| | - Guoqing Huang
- Department of Emergency, Xiangya Hospital Central South University, Changsha 410008, Hunan, China
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38
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Nerella SG, Singh P, Sanam T, Digwal CS. PET Molecular Imaging in Drug Development: The Imaging and Chemistry Perspective. Front Med (Lausanne) 2022; 9:812270. [PMID: 35295604 PMCID: PMC8919964 DOI: 10.3389/fmed.2022.812270] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Accepted: 01/18/2022] [Indexed: 11/13/2022] Open
Abstract
Positron emission tomography with selective radioligands advances the drug discovery and development process by revealing information about target engagement, proof of mechanism, pharmacokinetic and pharmacodynamic profiles. Positron emission tomography (PET) is an essential and highly significant tool to study therapeutic drug development, dose regimen, and the drug plasma concentrations of new drug candidates. Selective radioligands bring up target-specific information in several disease states including cancer, cardiovascular, and neurological conditions by quantifying various rates of biological processes with PET, which are associated with its physiological changes in living subjects, thus it reveals disease progression and also advances the clinical investigation. This study explores the major roles, applications, and advances of PET molecular imaging in drug discovery and development process with a wide range of radiochemistry as well as clinical outcomes of positron-emitting carbon-11 and fluorine-18 radiotracers.
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Affiliation(s)
- Sridhar Goud Nerella
- Department of Neuroimaging and Interventional Radiology, National Institute of Mental Health and Neurosciences, Bengaluru, India
| | - Priti Singh
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research, Hyderabad, India
| | - Tulja Sanam
- Department of Microbiology and Applied Sciences, University of Agricultural Sciences, Bangalore, India
| | - Chander Singh Digwal
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research, Hyderabad, India
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Design, Synthesis, and Biological Evaluation of 4,4’-Difluorobenzhydrol Carbamates as Selective M1 Antagonists. Pharmaceuticals (Basel) 2022; 15:ph15020248. [PMID: 35215360 PMCID: PMC8879200 DOI: 10.3390/ph15020248] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Revised: 02/05/2022] [Accepted: 02/14/2022] [Indexed: 11/17/2022] Open
Abstract
Due to their important role in mediating a broad range of physiological functions, muscarinic acetylcholine receptors (mAChRs) have been a promising target for therapeutic and diagnostic applications alike; however, the list of truly subtype-selective ligands is scarce. Within this work, we have identified a series of twelve 4,4’-difluorobenzhydrol carbamates through a rigorous docking campaign leveraging commercially available amine databases. After synthesis, these compounds have been evaluated for their physico–chemical property profiles, including characteristics such as HPLC-logD, tPSA, logBB, and logPS. For all the synthesized carbamates, these characteristics indicate the potential for BBB permeation. In competitive radioligand binding experiments using Chinese hamster ovary cell membranes expressing the individual human mAChR subtype hM1-hM5, the most promising compound 2 displayed a high binding affinitiy towards hM1R (1.2 nM) while exhibiting modest-to-excellent selectivity versus the hM2-5R (4–189-fold). All 12 compounds were shown to act in an antagonistic fashion towards hM1R using a dose-dependent calcium mobilization assay. The structural eligibility for radiolabeling and their pharmacological and physico–chemical property profiles render compounds 2, 5, and 7 promising candidates for future position emission tomography (PET) tracer development.
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40
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Boisson F, Serriere S, Cao L, Bodard S, Pilleri A, Thomas L, Sportelli G, Vercouillie J, Emond P, Tauber C, Belcari N, Lefaucheur JL, Brasse D, Galineau L. Performance evaluation of the IRIS XL-220 PET/CT system, a new camera dedicated to non-human primates. EJNMMI Phys 2022; 9:10. [PMID: 35122556 PMCID: PMC8818072 DOI: 10.1186/s40658-022-00440-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Accepted: 01/24/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Non-human primates (NHP) are critical in biomedical research to better understand the pathophysiology of diseases and develop new therapies. Based on its translational and longitudinal abilities along with its non-invasiveness, PET/CT systems dedicated to non-human primates can play an important role for future discoveries in medical research. The aim of this study was to evaluate the performance of a new PET/CT system dedicated to NHP imaging, the IRIS XL-220 developed by Inviscan SAS. This was performed based on the National Electrical Manufacturers Association (NEMA) NU 4-2008 standard recommendations (NEMA) to characterize the spatial resolution, the scatter fraction, the sensitivity, the count rate, and the image quality of the system. Besides, the system was evaluated in real conditions with two NHP with 18F-FDG and (-)-[18F]FEOBV which targets the vesicular acetylcholine transporter, and one rat using 18F-FDG. RESULTS The full width at half maximum obtained with the 3D OSEM algorithm ranged between 0.89 and 2.11 mm in the field of view. Maximum sensitivity in the 400-620 keV and 250-750 keV energy windows were 2.37% (22 cps/kBq) and 2.81% (25 cps/kBq), respectively. The maximum noise equivalent count rate (NEC) for a rat phantom was 82 kcps at 75 MBq and 88 kcps at 75 MBq for energy window of 250-750 and 400-620 keV, respectively. For the monkey phantom, the maximum NEC was 18 kcps at 126 MBq and 19 kcps at 126 MBq for energy window of 250-750 and 400-620 keV, respectively. The IRIS XL provided an excellent quality of images in non-human primates and rats using 18F-FDG. The images acquired using (-)-[18F]FEOBV were consistent with those previously reported in non-human primates. CONCLUSIONS Taken together, these results showed that the IRIS XL-220 is a high-resolution system well suited for PET/CT imaging in non-human primates.
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Affiliation(s)
- Frédéric Boisson
- Institut Pluridisciplinaire Hubert Curien, Université de Strasbourg, 23 rue du Loess, 67037, Strasbourg, France.,UMR7178, CNRS, 67037, Strasbourg, France
| | - Sophie Serriere
- UMR 1253, IBrain, Équipe Imagerie, Biomarqueurs et Thérapie, Université de Tours, Inserm, UFR Médecine, 10 boulevard Tonnellé, Bât. Planiol 4ème étage, 37000, Tours, France.,Département d'Imagerie Préclinique, Plateforme Scientifique et Technique Analyse des Systèmes Biologiques, Université de Tours, Tours, France
| | - Liji Cao
- Inviscan SAS, Strasbourg, France
| | - Sylvie Bodard
- UMR 1253, IBrain, Équipe Imagerie, Biomarqueurs et Thérapie, Université de Tours, Inserm, UFR Médecine, 10 boulevard Tonnellé, Bât. Planiol 4ème étage, 37000, Tours, France
| | - Alessandro Pilleri
- Department of Physics, University of Pisa, Largo Bruno Pontecorvo 3, 56127, Pisa, Italy
| | - Lionel Thomas
- Institut Pluridisciplinaire Hubert Curien, Université de Strasbourg, 23 rue du Loess, 67037, Strasbourg, France.,UMR7178, CNRS, 67037, Strasbourg, France
| | - Giancarlo Sportelli
- Department of Physics, University of Pisa, Largo Bruno Pontecorvo 3, 56127, Pisa, Italy
| | - Johnny Vercouillie
- UMR 1253, IBrain, Équipe Imagerie, Biomarqueurs et Thérapie, Université de Tours, Inserm, UFR Médecine, 10 boulevard Tonnellé, Bât. Planiol 4ème étage, 37000, Tours, France
| | - Patrick Emond
- UMR 1253, IBrain, Équipe Imagerie, Biomarqueurs et Thérapie, Université de Tours, Inserm, UFR Médecine, 10 boulevard Tonnellé, Bât. Planiol 4ème étage, 37000, Tours, France.,Département d'Imagerie Préclinique, Plateforme Scientifique et Technique Analyse des Systèmes Biologiques, Université de Tours, Tours, France
| | - Clovis Tauber
- UMR 1253, IBrain, Équipe Imagerie, Biomarqueurs et Thérapie, Université de Tours, Inserm, UFR Médecine, 10 boulevard Tonnellé, Bât. Planiol 4ème étage, 37000, Tours, France
| | - Nicola Belcari
- Department of Physics, University of Pisa, Largo Bruno Pontecorvo 3, 56127, Pisa, Italy
| | | | - David Brasse
- Institut Pluridisciplinaire Hubert Curien, Université de Strasbourg, 23 rue du Loess, 67037, Strasbourg, France.,UMR7178, CNRS, 67037, Strasbourg, France
| | - Laurent Galineau
- UMR 1253, IBrain, Équipe Imagerie, Biomarqueurs et Thérapie, Université de Tours, Inserm, UFR Médecine, 10 boulevard Tonnellé, Bât. Planiol 4ème étage, 37000, Tours, France. .,Département d'Imagerie Préclinique, Plateforme Scientifique et Technique Analyse des Systèmes Biologiques, Université de Tours, Tours, France.
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Neuroimaging of Mouse Models of Alzheimer’s Disease. Biomedicines 2022; 10:biomedicines10020305. [PMID: 35203515 PMCID: PMC8869427 DOI: 10.3390/biomedicines10020305] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 01/25/2022] [Accepted: 01/25/2022] [Indexed: 12/23/2022] Open
Abstract
Magnetic resonance imaging (MRI) and positron emission tomography (PET) have made great strides in the diagnosis and our understanding of Alzheimer’s Disease (AD). Despite the knowledge gained from human studies, mouse models have and continue to play an important role in deciphering the cellular and molecular evolution of AD. MRI and PET are now being increasingly used to investigate neuroimaging features in mouse models and provide the basis for rapid translation to the clinical setting. Here, we provide an overview of the human MRI and PET imaging landscape as a prelude to an in-depth review of preclinical imaging in mice. A broad range of mouse models recapitulate certain aspects of the human AD, but no single model simulates the human disease spectrum. We focused on the two of the most popular mouse models, the 3xTg-AD and the 5xFAD models, and we summarized all known published MRI and PET imaging data, including contrasting findings. The goal of this review is to provide the reader with broad framework to guide future studies in existing and future mouse models of AD. We also highlight aspects of MRI and PET imaging that could be improved to increase rigor and reproducibility in future imaging studies.
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Masturzo L, Carra P, Erba PA, Morrocchi M, Pilleri A, Sportelli G, Belcari N. Monte Carlo Characterization of the Trimage Brain PET System. J Imaging 2022; 8:jimaging8020021. [PMID: 35200724 PMCID: PMC8878795 DOI: 10.3390/jimaging8020021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 01/13/2022] [Accepted: 01/20/2022] [Indexed: 11/16/2022] Open
Abstract
The TRIMAGE project aims to develop a brain-dedicated PET/MR/EEG (Positron Emission Tomography/Magnetic Resonance/Electroencephalogram) system that is able to perform simultaneous PET, MR and EEG acquisitions. The PET component consists of a full ring with 18 sectors. Each sector includes three square detector modules based on dual sstaggered LYSO:Ce matrices read out by SiPMs. Using Monte Carlo simulations and following NEMA (National Electrical Manufacturers Association) guidelines, image quality procedures have been applied to evaluate the performance of the PET component of the system. The performance are reported in terms of spatial resolution, uniformity, recovery coefficient, spill over ratio, noise equivalent count rate (NECR) and scatter fraction. The results show that the TRIMAGE system is at the top of the current brain PET technologies.
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Affiliation(s)
- Luigi Masturzo
- Department of Physics “E. Fermi”, University of Pisa, 56127 Pisa, Italy; (L.M.); (P.C.); (M.M.); (A.P.); (N.B.)
| | - Pietro Carra
- Department of Physics “E. Fermi”, University of Pisa, 56127 Pisa, Italy; (L.M.); (P.C.); (M.M.); (A.P.); (N.B.)
- National Institute of Nuclear Physics (INFN), Pisa Section, 56127 Pisa, Italy
| | - Paola Anna Erba
- Department of Translational Research and New Technology in Medicine and Surgery, Regional Center of Nuclear Medicine, Azienda Ospedaliero Universitaria Pisana, University of Pisa, 56126 Pisa, Italy;
| | - Matteo Morrocchi
- Department of Physics “E. Fermi”, University of Pisa, 56127 Pisa, Italy; (L.M.); (P.C.); (M.M.); (A.P.); (N.B.)
- National Institute of Nuclear Physics (INFN), Pisa Section, 56127 Pisa, Italy
| | - Alessandro Pilleri
- Department of Physics “E. Fermi”, University of Pisa, 56127 Pisa, Italy; (L.M.); (P.C.); (M.M.); (A.P.); (N.B.)
| | - Giancarlo Sportelli
- Department of Physics “E. Fermi”, University of Pisa, 56127 Pisa, Italy; (L.M.); (P.C.); (M.M.); (A.P.); (N.B.)
- National Institute of Nuclear Physics (INFN), Pisa Section, 56127 Pisa, Italy
- Correspondence:
| | - Nicola Belcari
- Department of Physics “E. Fermi”, University of Pisa, 56127 Pisa, Italy; (L.M.); (P.C.); (M.M.); (A.P.); (N.B.)
- National Institute of Nuclear Physics (INFN), Pisa Section, 56127 Pisa, Italy
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Fu Z, Lin Q, Xu Z, Zhao Y, Cheng Y, Shi D, Fu W, Yang T, Shi H, Cheng D. P2X7 receptor-specific radioligand 18F-FTTM for atherosclerotic plaque PET imaging. Eur J Nucl Med Mol Imaging 2022; 49:2595-2604. [PMID: 35048153 DOI: 10.1007/s00259-022-05689-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Accepted: 01/11/2022] [Indexed: 11/28/2022]
Abstract
PURPOSE P2X7 receptors have been considered as a promising biomarker for vulnerable atherosclerotic plaques, which are highly expressed by that instability-associated factors such as macrophages. Thus, we aim to investigate the feasibility of using specific P2X7-targeted 18F-labeled tracer 18F-FTTM ((2-chloro-3-[18F]fluorophenyl)[1,4,6,7-tetrahydro-1-(2-pyrimidinyl)-5H-1,2,3-triazolo[4,5-c]pyridin-5-yl]methanone) for PET study of vulnerable atherosclerotic plaques identification. METHOD The radioligand 18F-FTTM was achieved based on the copper-mediated radiofluorination of arylstannane. In vitro and in vivo experiments were performed to verify the biochemical properties. Dynamic 18F-FTTM Micro-PET/CT imaging was performed for 1 h on ApoE-/- mice (10, 20, 30 weeks on high-fat diet) and wild-type C57BL/6 J mice on normal diet. Ex vivo PET imaging was conducted to verify the specificity of the radioligand. Serum inflammatory cytokines, lipids, and lipoproteins profiles were detected by ELISA. The lipid distribution and morphology of plaques were evaluated by Oil Red O, HE, Masson, and immunofluorescence stainings. RESULTS 18F-FTTM was afforded with decay-corrected radiochemical yields of 5-10%, specific activity of 269-320 MBq/nmol (n = 8, EOS), and radiochemical purity of above 99%. 18F-FTTM showed excellent stability in vitro, rapid blood clearance in mice, good affinity to RAW264.7 cells. We observed an increase in both in vivo and ex vivo imagings as disease progressed, and the imaging signatures correlated with histopathological features. Furthermore, compared with 18F-FDG imaging, the SUVmax values of 18F-FTTM at the aortic arch of ApoE-/- mice of high-fat feeding for 20 and 30 weeks were 43% and 53% higher than those of the control group, respectively. CONCLUSION We innovatively apply a new type P2X7-targeted PET probe (18F-FTTM) to identify vulnerable atherosclerotic plaques, to detect the inflammatory response of atherosclerosis, and to provide a powerful non-invasive method for the diagnosis of atherosclerotic lesions and new drug screening for accurate treatment.
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Affiliation(s)
- Zhequan Fu
- Department of Nuclear Medicine, Zhongshan Hospital, Fudan University, 180 Fenglin Rd, Shanghai, 200032, China.,Institute of Nuclear Medicine, Fudan University, Shanghai, 200032, China.,Shanghai Institute of Medical Imaging, Shanghai, 200032, China
| | - Qingyu Lin
- Department of Nuclear Medicine, Zhongshan Hospital, Fudan University, 180 Fenglin Rd, Shanghai, 200032, China.,Institute of Nuclear Medicine, Fudan University, Shanghai, 200032, China.,Shanghai Institute of Medical Imaging, Shanghai, 200032, China
| | - Zhan Xu
- Department of Nuclear Medicine, Zhongshan Hospital, Fudan University, 180 Fenglin Rd, Shanghai, 200032, China.,Institute of Nuclear Medicine, Fudan University, Shanghai, 200032, China.,Shanghai Institute of Medical Imaging, Shanghai, 200032, China
| | - Yanzhao Zhao
- Department of Nuclear Medicine, Zhongshan Hospital, Fudan University, 180 Fenglin Rd, Shanghai, 200032, China.,Institute of Nuclear Medicine, Fudan University, Shanghai, 200032, China.,Shanghai Institute of Medical Imaging, Shanghai, 200032, China
| | - Yuan Cheng
- Department of Nuclear Medicine, Zhongshan Hospital, Fudan University, 180 Fenglin Rd, Shanghai, 200032, China.,Institute of Nuclear Medicine, Fudan University, Shanghai, 200032, China.,Shanghai Institute of Medical Imaging, Shanghai, 200032, China
| | - Dai Shi
- Department of Nuclear Medicine, Zhongshan Hospital, Fudan University, 180 Fenglin Rd, Shanghai, 200032, China.,Institute of Nuclear Medicine, Fudan University, Shanghai, 200032, China.,Shanghai Institute of Medical Imaging, Shanghai, 200032, China
| | - Wenhui Fu
- Department of Nuclear Medicine, Zhongshan Hospital, Fudan University, 180 Fenglin Rd, Shanghai, 200032, China.,Institute of Nuclear Medicine, Fudan University, Shanghai, 200032, China.,Shanghai Institute of Medical Imaging, Shanghai, 200032, China
| | - Tingting Yang
- Department of Nuclear Medicine, Zhongshan Hospital, Fudan University, 180 Fenglin Rd, Shanghai, 200032, China.,Institute of Nuclear Medicine, Fudan University, Shanghai, 200032, China.,Shanghai Institute of Medical Imaging, Shanghai, 200032, China
| | - Hongcheng Shi
- Department of Nuclear Medicine, Zhongshan Hospital, Fudan University, 180 Fenglin Rd, Shanghai, 200032, China. .,Institute of Nuclear Medicine, Fudan University, Shanghai, 200032, China. .,Shanghai Institute of Medical Imaging, Shanghai, 200032, China.
| | - Dengfeng Cheng
- Department of Nuclear Medicine, Zhongshan Hospital, Fudan University, 180 Fenglin Rd, Shanghai, 200032, China. .,Institute of Nuclear Medicine, Fudan University, Shanghai, 200032, China. .,Shanghai Institute of Medical Imaging, Shanghai, 200032, China.
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44
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Khoodoruth MAS, Estudillo-Guerra MA, Pacheco-Barrios K, Nyundo A, Chapa-Koloffon G, Ouanes S. Glutamatergic System in Depression and Its Role in Neuromodulatory Techniques Optimization. Front Psychiatry 2022; 13:886918. [PMID: 35492692 PMCID: PMC9047946 DOI: 10.3389/fpsyt.2022.886918] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Accepted: 03/28/2022] [Indexed: 11/17/2022] Open
Abstract
Depressive disorders are among the most common psychiatric conditions and contribute to significant morbidity. Even though the use of antidepressants revolutionized the management of depression and had a tremendous positive impact on the patient's outcome, a significant proportion of patients with major depressive disorder (MDD) show no or partial or response even with adequate treatment. Given the limitations of the prevailing monoamine hypothesis-based pharmacotherapy, glutamate and glutamatergic related pathways may offer an alternative and a complementary option for designing novel intervention strategies. Over the past few decades, there has been a growing interest in understanding the neurobiological underpinnings of glutamatergic dysfunctions in the pathogenesis of depressive disorders and the development of new pharmacological and non-pharmacological treatment options. There is a growing body of evidence for the efficacy of neuromodulation techniques, including transcranial magnetic stimulation, transcutaneous direct current stimulation, transcranial alternating current stimulation, and photo-biomodulation on improving connectivity and neuroplasticity associated with depression. This review attempts to revisit the role of glutamatergic neurotransmission in the etiopathogenesis of depressive disorders and review the current neuroimaging, neurophysiological and clinical evidence of these neuromodulation techniques in the pathophysiology and treatment of depression.
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Affiliation(s)
| | - Maria Anayali Estudillo-Guerra
- Department of Physical Medicine and Rehabilitation, Harvard Medical School, Spaulding Rehabilitation Hospital, Boston, MA, United States
| | - Kevin Pacheco-Barrios
- Neuromodulation Center and Center for Clinical Research Learning, Harvard Medical School, Spaulding Rehabilitation Hospital and Massachusetts General Hospital, Boston, MA, United States.,Universidad San Ignacio de Loyola, Vicerrectorado de Investigación, Unidad de Investigación para la Generación y Síntesis de Evidencias en Salud, Lima, Peru
| | - Azan Nyundo
- Department of Psychiatry and Mental Health, School of Medicine and Dental Health, The University of Dodoma, Dodoma, Tanzania
| | | | - Sami Ouanes
- Department of Psychiatry, Hamad Medical Corporation, Doha, Qatar
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45
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Shimojo M, Ono M, Takuwa H, Mimura K, Nagai Y, Fujinaga M, Kikuchi T, Okada M, Seki C, Tokunaga M, Maeda J, Takado Y, Takahashi M, Minamihisamatsu T, Zhang M, Tomita Y, Suzuki N, Maximov A, Suhara T, Minamimoto T, Sahara N, Higuchi M. A genetically targeted reporter for PET imaging of deep neuronal circuits in mammalian brains. EMBO J 2021; 40:e107757. [PMID: 34636430 PMCID: PMC8591537 DOI: 10.15252/embj.2021107757] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2021] [Revised: 08/24/2021] [Accepted: 08/31/2021] [Indexed: 01/27/2023] Open
Abstract
Positron emission tomography (PET) allows biomolecular tracking but PET monitoring of brain networks has been hampered by a lack of suitable reporters. Here, we take advantage of bacterial dihydrofolate reductase, ecDHFR, and its unique antagonist, TMP, to facilitate in vivo imaging in the brain. Peripheral administration of radiofluorinated and fluorescent TMP analogs enabled PET and intravital microscopy, respectively, of neuronal ecDHFR expression in mice. This technique can be used to the visualize neuronal circuit activity elicited by chemogenetic manipulation in the mouse hippocampus. Notably, ecDHFR-PET allows mapping of neuronal projections in non-human primate brains, demonstrating the applicability of ecDHFR-based tracking technologies for network monitoring. Finally, we demonstrate the utility of TMP analogs for PET studies of turnover and self-assembly of proteins tagged with ecDHFR mutants. These results establish opportunities for a broad spectrum of previously unattainable PET analyses of mammalian brain circuits at the molecular level.
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Affiliation(s)
- Masafumi Shimojo
- Department of Functional Brain ImagingNational Institutes for Quantum and Radiological Science and TechnologyChibaJapan
| | - Maiko Ono
- Department of Functional Brain ImagingNational Institutes for Quantum and Radiological Science and TechnologyChibaJapan
| | - Hiroyuki Takuwa
- Department of Functional Brain ImagingNational Institutes for Quantum and Radiological Science and TechnologyChibaJapan
| | - Koki Mimura
- Department of Functional Brain ImagingNational Institutes for Quantum and Radiological Science and TechnologyChibaJapan
| | - Yuji Nagai
- Department of Functional Brain ImagingNational Institutes for Quantum and Radiological Science and TechnologyChibaJapan
| | - Masayuki Fujinaga
- Department of Radiopharmaceuticals DevelopmentNational Institutes for Quantum and Radiological Science and TechnologyChibaJapan
| | - Tatsuya Kikuchi
- Department of Radiopharmaceuticals DevelopmentNational Institutes for Quantum and Radiological Science and TechnologyChibaJapan
| | - Maki Okada
- Department of Radiopharmaceuticals DevelopmentNational Institutes for Quantum and Radiological Science and TechnologyChibaJapan
| | - Chie Seki
- Department of Functional Brain ImagingNational Institutes for Quantum and Radiological Science and TechnologyChibaJapan
| | - Masaki Tokunaga
- Department of Functional Brain ImagingNational Institutes for Quantum and Radiological Science and TechnologyChibaJapan
| | - Jun Maeda
- Department of Functional Brain ImagingNational Institutes for Quantum and Radiological Science and TechnologyChibaJapan
| | - Yuhei Takado
- Department of Functional Brain ImagingNational Institutes for Quantum and Radiological Science and TechnologyChibaJapan
| | - Manami Takahashi
- Department of Functional Brain ImagingNational Institutes for Quantum and Radiological Science and TechnologyChibaJapan
| | - Takeharu Minamihisamatsu
- Department of Functional Brain ImagingNational Institutes for Quantum and Radiological Science and TechnologyChibaJapan
| | - Ming‐Rong Zhang
- Department of Radiopharmaceuticals DevelopmentNational Institutes for Quantum and Radiological Science and TechnologyChibaJapan
| | - Yutaka Tomita
- Department of NeurologyKeio University School of MedicineTokyoJapan
| | - Norihiro Suzuki
- Department of NeurologyKeio University School of MedicineTokyoJapan
| | - Anton Maximov
- Department of NeuroscienceThe Scripps Research InstituteLa JollaCAUSA
| | - Tetsuya Suhara
- Department of Functional Brain ImagingNational Institutes for Quantum and Radiological Science and TechnologyChibaJapan
| | - Takafumi Minamimoto
- Department of Functional Brain ImagingNational Institutes for Quantum and Radiological Science and TechnologyChibaJapan
| | - Naruhiko Sahara
- Department of Functional Brain ImagingNational Institutes for Quantum and Radiological Science and TechnologyChibaJapan
| | - Makoto Higuchi
- Department of Functional Brain ImagingNational Institutes for Quantum and Radiological Science and TechnologyChibaJapan
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46
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de Laat B, Hoye J, Liu H, Morris ED. EC 50 images, a novel endpoint from PET target occupancy studies, reveal spatial variation in apparent drug affinity. Eur J Nucl Med Mol Imaging 2021; 49:1232-1241. [PMID: 34636937 DOI: 10.1007/s00259-021-05561-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Accepted: 09/06/2021] [Indexed: 11/25/2022]
Abstract
PURPOSE We recently introduced voxel-level images of drug occupancy from PET via our "Lassen plot filter." Occupancy images revealed clear dependence of 11C-flumazenil displacement on dose of GABAa inhibitor, CVL-865, but with different scales in different brain regions. We hypothesized that regions requiring higher drug concentrations to achieve desired occupancy would have higher EC50 values. We introduce an "EC50 image" from human data to evaluate this hypothesis. METHODS Five healthy subjects were scanned with the nonselective GABAa tracer, 11C-flumazenil, before and (twice) after administration of CVL-865. We created ten occupancy images and applied an Emax model locally to create one EC50 image. We also performed simulations to confirm our observations of regional variation in EC50 and to identify the main source of variability in EC50. RESULTS As expected, the EC50 image revealed spatial variation in apparent drug affinity. High EC50 was found in areas of low occupancy for a given drug dose. Simulations demonstrated that sampling from an inadequate range of plasma drug concentrations could impair precision. CONCLUSION Our results argue for (a) confidence in the ability of the EC50 images to identify regional differences and (b) a need to tailor the range of drug doses in an occupancy study to regularize the precision of the EC50 throughout the brain. The EC50 image could add value to early-phase drug development by identifying regional variation in affinity that might impact therapy or safety and by guiding dose selection for later-phase trials.
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Affiliation(s)
- Bart de Laat
- Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT, USA
| | - Jocelyn Hoye
- Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT, USA
| | - Heather Liu
- Department of Biomedical Engineering, Yale University, CT, New Haven, USA
| | - Evan D Morris
- Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT, USA.
- Department of Psychiatry, Yale University, New Haven, CT, USA.
- Department of Biomedical Engineering, Yale University, CT, New Haven, USA.
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47
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Lim TX, Ahamed M, Reutens DC. The aryl hydrocarbon receptor: A diagnostic and therapeutic target in glioma. Drug Discov Today 2021; 27:422-435. [PMID: 34624509 DOI: 10.1016/j.drudis.2021.09.021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 07/29/2021] [Accepted: 09/29/2021] [Indexed: 12/19/2022]
Abstract
Glioblastoma multiforme (GBM) is a deadly disease; 5-year survival rates have shown little improvement over the past 30 years. In vivo positron emission tomography (PET) imaging is an important method of identifying potential diagnostic and therapeutic molecular targets non-invasively. The aryl hydrocarbon receptor (AhR) is a transcription factor that regulates multiple genes involved in immune response modulation and tumorigenesis. The AhR is an attractive potential drug target and studies have shown that its activation by small molecules can modulate innate and adaptive immunity beneficially and prevent AhR-mediated tumour promotion in several cancer types. In this review, we provide an overview of the role of the AhR in glioma tumorigenesis and highlight its potential as an emerging biomarker for glioma therapies targeting the tumour immune response and PET diagnostics.
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Affiliation(s)
- Ting Xiang Lim
- ARC Centre for Innovation in Biomedical Imaging Technology, Centre for Advanced Imaging, The University of Queensland, Brisbane, QLD, Australia
| | - Muneer Ahamed
- ARC Centre for Innovation in Biomedical Imaging Technology, Centre for Advanced Imaging, The University of Queensland, Brisbane, QLD, Australia
| | - David C Reutens
- ARC Centre for Innovation in Biomedical Imaging Technology, Centre for Advanced Imaging, The University of Queensland, Brisbane, QLD, Australia.
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48
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Tournier N, Comtat C, Lebon V, Gennisson JL. Challenges and Perspectives of the Hybridization of PET with Functional MRI or Ultrasound for Neuroimaging. Neuroscience 2021; 474:80-93. [DOI: 10.1016/j.neuroscience.2020.10.015] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2020] [Revised: 10/06/2020] [Accepted: 10/08/2020] [Indexed: 02/08/2023]
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49
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Veronese M, Rizzo G, Belzunce M, Schubert J, Searle G, Whittington A, Mansur A, Dunn J, Reader A, Gunn RN. Reproducibility of findings in modern PET neuroimaging: insight from the NRM2018 grand challenge. J Cereb Blood Flow Metab 2021; 41:2778-2796. [PMID: 33993794 PMCID: PMC8504414 DOI: 10.1177/0271678x211015101] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 03/10/2021] [Accepted: 04/03/2021] [Indexed: 11/16/2022]
Abstract
The reproducibility of findings is a compelling methodological problem that the neuroimaging community is facing these days. The lack of standardized pipelines for image processing, quantification and statistics plays a major role in the variability and interpretation of results, even when the same data are analysed. This problem is well-known in MRI studies, where the indisputable value of the method has been complicated by a number of studies that produce discrepant results. However, any research domain with complex data and flexible analytical procedures can experience a similar lack of reproducibility. In this paper we investigate this issue for brain PET imaging. During the 2018 NeuroReceptor Mapping conference, the brain PET community was challenged with a computational contest involving a simulated neurotransmitter release experiment. Fourteen international teams analysed the same imaging dataset, for which the ground-truth was known. Despite a plurality of methods, the solutions were consistent across participants, although not identical. These results should create awareness that the increased sharing of PET data alone will only be one component of enhancing confidence in neuroimaging results and that it will be important to complement this with full details of the analysis pipelines and procedures that have been used to quantify data.
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Affiliation(s)
- Mattia Veronese
- Centre for Neuroimaging Sciences, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, UK
| | | | - Martin Belzunce
- School of Biomedical Engineering and Imaging Sciences, St Thomas’ Hospital, King’s College London, London, UK
| | - Julia Schubert
- Centre for Neuroimaging Sciences, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, UK
| | | | | | - Ayla Mansur
- Invicro LLC, London, UK
- Department of Brain Sciences, Imperial College London, London, UK
| | - Joel Dunn
- School of Biomedical Engineering and Imaging Sciences, St Thomas’ Hospital, King’s College London, London, UK
- King's College London & Guy's and St. Thomas' PET Centre, London, UK
| | - Andrew Reader
- School of Biomedical Engineering and Imaging Sciences, St Thomas’ Hospital, King’s College London, London, UK
| | - Roger N Gunn
- Invicro LLC, London, UK
- Department of Brain Sciences, Imperial College London, London, UK
| | - and the Grand Challenge Participants#
- Centre for Neuroimaging Sciences, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, UK
- Invicro LLC, London, UK
- School of Biomedical Engineering and Imaging Sciences, St Thomas’ Hospital, King’s College London, London, UK
- Department of Brain Sciences, Imperial College London, London, UK
- King's College London & Guy's and St. Thomas' PET Centre, London, UK
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50
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Bidesi NSR, Vang Andersen I, Windhorst AD, Shalgunov V, Herth MM. The role of neuroimaging in Parkinson's disease. J Neurochem 2021; 159:660-689. [PMID: 34532856 PMCID: PMC9291628 DOI: 10.1111/jnc.15516] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Revised: 09/09/2021] [Accepted: 09/10/2021] [Indexed: 11/29/2022]
Abstract
Parkinson's disease (PD) is a neurodegenerative disorder that affects millions of people worldwide. Two hallmarks of PD are the accumulation of alpha-synuclein and the loss of dopaminergic neurons in the brain. There is no cure for PD, and all existing treatments focus on alleviating the symptoms. PD diagnosis is also based on the symptoms, such as abnormalities of movement, mood, and cognition observed in the patients. Molecular imaging methods such as magnetic resonance imaging (MRI), single-photon emission computed tomography (SPECT), and positron emission tomography (PET) can detect objective alterations in the neurochemical machinery of the brain and help diagnose and study neurodegenerative diseases. This review addresses the application of functional MRI, PET, and SPECT in PD patients. We provide an overview of the imaging targets, discuss the rationale behind target selection, the agents (tracers) with which the imaging can be performed, and the main findings regarding each target's state in PD. Molecular imaging has proven itself effective in supporting clinical diagnosis of PD and has helped reveal that PD is a heterogeneous disorder, which has important implications for the development of future therapies. However, the application of molecular imaging for early diagnosis of PD or for differentiation between PD and atypical parkinsonisms has remained challenging. The final section of the review is dedicated to new imaging targets with which one can detect the PD-related pathological changes upstream from dopaminergic degeneration. The foremost of those targets is alpha-synuclein. We discuss the progress of tracer development achieved so far and challenges on the path toward alpha-synuclein imaging in humans.
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Affiliation(s)
- Natasha S R Bidesi
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - Ida Vang Andersen
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - Albert D Windhorst
- Radiology and Nuclear Medicine, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - Vladimir Shalgunov
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - Matthias M Herth
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark.,Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, Copenhagen, Denmark
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