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Reid VJM, McLoughlin WKX, Pandya K, Stott H, Iškauskienė M, Šačkus A, Marti JA, Kurian D, Wishart TM, Lucatelli C, Peters D, Gray GA, Baker AH, Newby DE, Hadoke PWF, Tavares AAS, MacAskill MG. Assessment of the alpha 7 nicotinic acetylcholine receptor as an imaging marker of cardiac repair-associated processes using NS14490. EJNMMI Res 2024; 14:7. [PMID: 38206500 PMCID: PMC10784260 DOI: 10.1186/s13550-023-01058-2] [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: 08/15/2023] [Accepted: 12/12/2023] [Indexed: 01/12/2024] Open
Abstract
BACKGROUND Cardiac repair and remodeling following myocardial infarction (MI) is a multifactorial process involving pro-reparative inflammation, angiogenesis and fibrosis. Noninvasive imaging using a radiotracer targeting these processes could be used to elucidate cardiac wound healing mechanisms. The alpha7 nicotinic acetylcholine receptor (ɑ7nAChR) stimulates pro-reparative macrophage activity and angiogenesis, making it a potential imaging biomarker in this context. We investigated this by assessing in vitro cellular expression of ɑ7nAChR, and by using a tritiated version of the PET radiotracer [18F]NS14490 in tissue autoradiography studies. RESULTS ɑ7nAChR expression in human monocyte-derived macrophages and vascular cells showed the highest relative expression was within macrophages, but only endothelial cells exhibited a proliferation and hypoxia-driven increase in expression. Using a mouse model of inflammatory angiogenesis following sponge implantation, specific binding of [3H]NS14490 increased from 3.6 ± 0.2 µCi/g at day 3 post-implantation to 4.9 ± 0.2 µCi/g at day 7 (n = 4, P < 0.01), followed by a reduction at days 14 and 21. This peak matched the onset of vessel formation, macrophage infiltration and sponge fibrovascular encapsulation. In a rat MI model, specific binding of [3H]NS14490 was low in sham and remote MI myocardium. Specific binding within the infarct increased from day 14 post-MI (33.8 ± 14.1 µCi/g, P ≤ 0.01 versus sham), peaking at day 28 (48.9 ± 5.1 µCi/g, P ≤ 0.0001 versus sham). Histological and proteomic profiling of ɑ7nAChR positive tissue revealed strong associations between ɑ7nAChR and extracellular matrix deposition, and rat cardiac fibroblasts expressed ɑ7nAChR protein under normoxic and hypoxic conditions. CONCLUSION ɑ7nAChR is highly expressed in human macrophages and showed proliferation and hypoxia-driven expression in human endothelial cells. While NS14490 imaging displays a pattern that coincides with vessel formation, macrophage infiltration and fibrovascular encapsulation in the sponge model, this is not the case in the MI model where the ɑ7nAChR imaging signal was strongly associated with extracellular matrix deposition which could be explained by ɑ7nAChR expression in fibroblasts. Overall, these findings support the involvement of ɑ7nAChR across several processes central to cardiac repair, with fibrosis most closely associated with ɑ7nAChR following MI.
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Affiliation(s)
- Victoria J M Reid
- Centre for Cardiovascular Science, The University of Edinburgh, Edinburgh, UK
- Edinburgh Imaging, The University of Edinburgh, Edinburgh, UK
| | | | - Kalyani Pandya
- Centre for Cardiovascular Science, The University of Edinburgh, Edinburgh, UK
- Edinburgh Imaging, The University of Edinburgh, Edinburgh, UK
| | - Holly Stott
- Centre for Cardiovascular Science, The University of Edinburgh, Edinburgh, UK
| | - Monika Iškauskienė
- Department of Organic Chemistry, Kaunas University of Technology, Kaunas, Lithuania
| | - Algirdas Šačkus
- Department of Organic Chemistry, Kaunas University of Technology, Kaunas, Lithuania
| | - Judit A Marti
- Proteomics and Metabolomics Facility, The Roslin Institute, University of Edinburgh, Edinburgh, UK
| | - Dominic Kurian
- Proteomics and Metabolomics Facility, The Roslin Institute, University of Edinburgh, Edinburgh, UK
| | - Thomas M Wishart
- Proteomics and Metabolomics Facility, The Roslin Institute, University of Edinburgh, Edinburgh, UK
| | | | - Dan Peters
- DanPET AB, Malmo, Sweden
- Neurobiology Research Unit, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
| | - Gillian A Gray
- Centre for Cardiovascular Science, The University of Edinburgh, Edinburgh, UK
| | - Andrew H Baker
- Centre for Cardiovascular Science, The University of Edinburgh, Edinburgh, UK
| | - David E Newby
- Centre for Cardiovascular Science, The University of Edinburgh, Edinburgh, UK
| | - Patrick W F Hadoke
- Centre for Cardiovascular Science, The University of Edinburgh, Edinburgh, UK
| | - Adriana A S Tavares
- Centre for Cardiovascular Science, The University of Edinburgh, Edinburgh, UK
- Edinburgh Imaging, The University of Edinburgh, Edinburgh, UK
| | - Mark G MacAskill
- Centre for Cardiovascular Science, The University of Edinburgh, Edinburgh, UK.
- Edinburgh Imaging, The University of Edinburgh, Edinburgh, UK.
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Zhang JJ, Fu H, Lin R, Zhou J, Haider A, Fang W, Elghazawy NH, Rong J, Chen J, Li Y, Ran C, Collier TL, Chen Z, Liang SH. Imaging Cholinergic Receptors in the Brain by Positron Emission Tomography. J Med Chem 2023; 66:10889-10916. [PMID: 37583063 PMCID: PMC10461233 DOI: 10.1021/acs.jmedchem.3c00573] [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: 03/30/2023] [Indexed: 08/17/2023]
Abstract
Cholinergic receptors represent a promising class of diagnostic and therapeutic targets due to their significant involvement in cognitive decline associated with neurological disorders and neurodegenerative diseases as well as cardiovascular impairment. Positron emission tomography (PET) is a noninvasive molecular imaging tool that has helped to shed light on the roles these receptors play in disease development and their diverse functions throughout the central nervous system (CNS). In recent years, there has been a notable advancement in the development of PET probes targeting cholinergic receptors. The purpose of this review is to provide a comprehensive overview of the recent progress in the development of these PET probes for cholinergic receptors with a specific focus on ligand structure, radiochemistry, and pharmacology as well as in vivo performance and applications in neuroimaging. The review covers the structural design, pharmacological properties, radiosynthesis approaches, and preclinical and clinical evaluations of current state-of-the-art PET probes for cholinergic receptors.
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Affiliation(s)
- Jing-Jing Zhang
- Jiangsu
Co-Innovation Center of Efficient Processing and Utilization of Forest
Resources, Jiangsu Provincial Key Lab for the Chemistry and Utilization
of Agro-Forest Biomass, Jiangsu Key Lab of Biomass-Based Green Fuels
and Chemicals, International Innovation Center for Forest Chemicals
and Materials, College of Chemical Engineering, Nanjing Forestry University, Nanjing, Jiangsu 210037, China
| | - Hualong Fu
- Division
of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital
& Department of Radiology, Harvard Medical
School, Boston, Massachusetts 02114, United States
- Key
Laboratory of Radiopharmaceuticals, Ministry of Education, College
of Chemistry, Beijing Normal University, Beijing 100875, China
| | - Ruofan Lin
- Jiangsu
Co-Innovation Center of Efficient Processing and Utilization of Forest
Resources, Jiangsu Provincial Key Lab for the Chemistry and Utilization
of Agro-Forest Biomass, Jiangsu Key Lab of Biomass-Based Green Fuels
and Chemicals, International Innovation Center for Forest Chemicals
and Materials, College of Chemical Engineering, Nanjing Forestry University, Nanjing, Jiangsu 210037, China
| | - Jingyin Zhou
- Key
Laboratory of Radiopharmaceuticals, Ministry of Education, College
of Chemistry, Beijing Normal University, Beijing 100875, China
| | - Ahmed Haider
- Division
of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital
& Department of Radiology, Harvard Medical
School, Boston, Massachusetts 02114, United States
- Department
of Radiology and Imaging Sciences, Emory
University, 1364 Clifton Road, Atlanta, Georgia 30322, United States
| | - Weiwei Fang
- Jiangsu
Co-Innovation Center of Efficient Processing and Utilization of Forest
Resources, Jiangsu Provincial Key Lab for the Chemistry and Utilization
of Agro-Forest Biomass, Jiangsu Key Lab of Biomass-Based Green Fuels
and Chemicals, International Innovation Center for Forest Chemicals
and Materials, College of Chemical Engineering, Nanjing Forestry University, Nanjing, Jiangsu 210037, China
| | - Nehal H. Elghazawy
- Department
of Pharmaceutical, Chemistry, Faculty of Pharmacy & Biotechnology, German University in Cairo, 11835 Cairo, Egypt
| | - Jian Rong
- Division
of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital
& Department of Radiology, Harvard Medical
School, Boston, Massachusetts 02114, United States
- Department
of Radiology and Imaging Sciences, Emory
University, 1364 Clifton Road, Atlanta, Georgia 30322, United States
| | - Jiahui Chen
- Division
of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital
& Department of Radiology, Harvard Medical
School, Boston, Massachusetts 02114, United States
- Department
of Radiology and Imaging Sciences, Emory
University, 1364 Clifton Road, Atlanta, Georgia 30322, United States
| | - Yinlong Li
- Division
of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital
& Department of Radiology, Harvard Medical
School, Boston, Massachusetts 02114, United States
- Department
of Radiology and Imaging Sciences, Emory
University, 1364 Clifton Road, Atlanta, Georgia 30322, United States
| | - Chongzhao Ran
- Athinoula
A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts 02114, United States
| | - Thomas L. Collier
- Division
of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital
& Department of Radiology, Harvard Medical
School, Boston, Massachusetts 02114, United States
- Department
of Radiology and Imaging Sciences, Emory
University, 1364 Clifton Road, Atlanta, Georgia 30322, United States
| | - Zhen Chen
- Jiangsu
Co-Innovation Center of Efficient Processing and Utilization of Forest
Resources, Jiangsu Provincial Key Lab for the Chemistry and Utilization
of Agro-Forest Biomass, Jiangsu Key Lab of Biomass-Based Green Fuels
and Chemicals, International Innovation Center for Forest Chemicals
and Materials, College of Chemical Engineering, Nanjing Forestry University, Nanjing, Jiangsu 210037, China
- Division
of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital
& Department of Radiology, Harvard Medical
School, Boston, Massachusetts 02114, United States
| | - Steven H. Liang
- Division
of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital
& Department of Radiology, Harvard Medical
School, Boston, Massachusetts 02114, United States
- Department
of Radiology and Imaging Sciences, Emory
University, 1364 Clifton Road, Atlanta, Georgia 30322, United States
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Nicotinic Acetylcholine Receptors and Microglia as Therapeutic and Imaging Targets in Alzheimer's Disease. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27092780. [PMID: 35566132 PMCID: PMC9102429 DOI: 10.3390/molecules27092780] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Revised: 04/21/2022] [Accepted: 04/25/2022] [Indexed: 12/12/2022]
Abstract
Amyloid-β (Aβ) accumulation and tauopathy are considered the pathological hallmarks of Alzheimer’s disease (AD), but attenuation in choline signaling, including decreased nicotinic acetylcholine receptors (nAChRs), is evident in the early phase of AD. Currently, there are no drugs that can suppress the progression of AD due to a limited understanding of AD pathophysiology. For this, diagnostic methods that can assess disease progression non-invasively before the onset of AD symptoms are essential, and it would be valuable to incorporate the concept of neurotheranostics, which simultaneously enables diagnosis and treatment. The neuroprotective pathways activated by nAChRs are attractive targets as these receptors may regulate microglial-mediated neuroinflammation. Microglia exhibit both pro- and anti-inflammatory functions that could be modulated to mitigate AD pathogenesis. Currently, single-cell analysis is identifying microglial subpopulations that may have specific functions in different stages of AD pathologies. Thus, the ability to image nAChRs and microglia in AD according to the stage of the disease in the living brain may lead to the development of new diagnostic and therapeutic methods. In this review, we summarize and discuss the recent findings on the nAChRs and microglia, as well as their methods for live imaging in the context of diagnosis, prophylaxis, and therapy for AD.
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4
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Molecular Imaging of Vulnerable Coronary Plaque with Radiolabeled Somatostatin Receptors (SSTR). J Clin Med 2021; 10:jcm10235515. [PMID: 34884218 PMCID: PMC8658082 DOI: 10.3390/jcm10235515] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 11/21/2021] [Accepted: 11/23/2021] [Indexed: 12/25/2022] Open
Abstract
Atherosclerosis is responsible for the majority of heart attacks and is characterized by several modifications of the arterial wall including an inflammatory reaction. The silent course of atherosclerosis has made it necessary to develop predictors of disease complications before symptomatic lesions occur. Vulnerable to rupture atherosclerotic plaques are the target for molecular imaging. To this aim, different radiopharmaceuticals for PET/CT have emerged for the identification of high-risk plaques, with high specificity for the identification of the cellular components and pathophysiological status of plaques. By targeting specific receptors on activated macrophages in high-risk plaques, radiolabelled somatostatin analogues such as 68Ga-DOTA-TOC, TATE,0 or NOC have shown high relevance to detect vulnerable, atherosclerotic plaques. This PET radiopharmaceutical has been tested in several pre-clinical and clinical studies, as reviewed here, showing an important correlation with other risk factors.
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5
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Research progress of 18F labeled small molecule positron emission tomography (PET) imaging agents. Eur J Med Chem 2020; 205:112629. [PMID: 32956956 DOI: 10.1016/j.ejmech.2020.112629] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2020] [Revised: 06/07/2020] [Accepted: 06/28/2020] [Indexed: 01/12/2023]
Abstract
With the development of positron emission tomography (PET) technology, a variety of PET imaging agents labeled with radionuclide 18F have been developed and widely used in the diagnosis and treatment of various clinical diseases in recent years. For example, they have showed a great value of study in the field of tumor detection, tumor treatment and evaluation of tumor therapy in a non-invasive, qualitative and quantitative way. In this review, we highlight the recent development in chemical synthesis, structure and characterization, imaging characterization, and potential applications of these 18F labeled small molecule PET imaging agents for the past five years. The development and application of 18F labeled small molecules will expand our knowledge of the function and distribution of diseases-related molecular targets and shed light on the diagnosis and treatment of various diseases including tumors.
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6
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MacAskill MG, Newby DE, Tavares AAS. Frontiers in positron emission tomography imaging of the vulnerable atherosclerotic plaque. Cardiovasc Res 2020; 115:1952-1962. [PMID: 31233100 DOI: 10.1093/cvr/cvz162] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 04/16/2019] [Accepted: 06/19/2019] [Indexed: 02/07/2023] Open
Abstract
Rupture of vulnerable atherosclerotic plaques leading to an atherothrombotic event is the primary driver of myocardial infarction and stroke. The ability to detect non-invasively the presence and evolution of vulnerable plaques could have a huge impact on the future identification and management of atherosclerotic cardiovascular disease. Positron emission tomography (PET) imaging with an appropriate radiotracer has the potential to achieve this goal. This review will discuss the biological hallmarks of plaque vulnerability before going on to evaluate and to present PET imaging approaches which target these processes. The focus of this review will be on techniques beyond [18F]FDG imaging, some of which are clinically advanced, and others which are on the horizon. As inflammation is the primary driving force behind atherosclerotic plaque development, we will predominantly focus on approaches which either directly, or indirectly, target this process.
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Affiliation(s)
- Mark G MacAskill
- University/BHF Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, UK.,Edinburgh Imaging, University of Edinburgh, Edinburgh, UK
| | - David E Newby
- University/BHF Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, UK
| | - Adriana A S Tavares
- University/BHF Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, UK.,Edinburgh Imaging, University of Edinburgh, Edinburgh, UK
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7
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Donat CK, Hansen HH, Hansen HD, Mease RC, Horti AG, Pomper MG, L’Estrade ET, Herth MM, Peters D, Knudsen GM, Mikkelsen JD. In Vitro and In Vivo Characterization of Dibenzothiophene Derivatives [ 125I]Iodo-ASEM and [ 18F]ASEM as Radiotracers of Homo- and Heteromeric α7 Nicotinic Acetylcholine Receptors. Molecules 2020; 25:molecules25061425. [PMID: 32245032 PMCID: PMC7144377 DOI: 10.3390/molecules25061425] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Revised: 02/25/2020] [Accepted: 02/27/2020] [Indexed: 12/18/2022] Open
Abstract
The α7 nicotinic acetylcholine receptor (α7 nAChR) is involved in several cognitive and physiologic processes; its expression levels and patterns change in neurologic and psychiatric diseases, such as schizophrenia and Alzheimer’s disease, which makes it a relevant drug target. Development of selective radioligands is important for defining binding properties and occupancy of novel molecules targeting the receptor. We tested the in vitro binding properties of [125I]Iodo-ASEM [(3-(1,4-diazabycyclo[3.2.2]nonan-4-yl)-6-(125I-iododibenzo[b,d]thiopentene 5,5-dioxide)] in the mouse, rat and pig brain using autoradiography. The in vivo binding properties of [18F]ASEM were investigated using positron emission tomography (PET) in the pig brain. [125I]Iodo-ASEM showed specific and displaceable high affinity (~1 nM) binding in mouse, rat, and pig brain. Binding pattern overlapped with [125I]α-bungarotoxin, specific binding was absent in α7 nAChR gene-deficient mice and binding was blocked by a range of α7 nAChR orthosteric modulators in an affinity-dependent order in the pig brain. Interestingly, relative to the wild-type, binding in β2 nAChR gene-deficient mice was lower for [125I]Iodo-ASEM (58% ± 2.7%) than [125I]α-bungarotoxin (23% ± 0.2%), potentially indicating different binding properties to heteromeric α7β2 nAChR. [18F]ASEM PET in the pig showed high brain uptake and reversible tracer kinetics with a similar spatial distribution as previously reported for α7 nAChR. Blocking with SSR-180,711 resulted in a significant decrease in [18F]ASEM binding. Our findings indicate that [125I]Iodo-ASEM allows sensitive and selective imaging of α7 nAChR in vitro, with better signal-to-noise ratio than previous tracers. Preliminary data of [18F]ASEM in the pig brain demonstrated principal suitable kinetic properties for in vivo quantification of α7 nAChR, comparable to previously published data.
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Affiliation(s)
- Cornelius K. Donat
- Neurobiology Research Unit, Copenhagen University Hospital, Rigshospitalet, DK-2100 Copenhagen, Denmark; (H.H.H.); (H.D.H.); (E.T.L.); (G.M.K.)
- Department of Brain Sciences, Imperial College London, London W12 0 LS, UK
- Correspondence: (C.K.D.); (J.D.M.); Tel.: +45-40205378 (J.D.M)
| | - Henrik H. Hansen
- Neurobiology Research Unit, Copenhagen University Hospital, Rigshospitalet, DK-2100 Copenhagen, Denmark; (H.H.H.); (H.D.H.); (E.T.L.); (G.M.K.)
| | - Hanne D. Hansen
- Neurobiology Research Unit, Copenhagen University Hospital, Rigshospitalet, DK-2100 Copenhagen, Denmark; (H.H.H.); (H.D.H.); (E.T.L.); (G.M.K.)
| | - Ronnie C. Mease
- Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA; (R.C.M.); (A.G.H.); (M.G.P.)
| | - Andrew G. Horti
- Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA; (R.C.M.); (A.G.H.); (M.G.P.)
| | - Martin G. Pomper
- Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA; (R.C.M.); (A.G.H.); (M.G.P.)
| | - Elina T. L’Estrade
- Neurobiology Research Unit, Copenhagen University Hospital, Rigshospitalet, DK-2100 Copenhagen, Denmark; (H.H.H.); (H.D.H.); (E.T.L.); (G.M.K.)
- Department of Drug Design and Pharmacology, University of Copenhagen, Jagtvej 162, 2100 Copenhagen, Denmark;
- Department of Clinical Physiology, Nuclear Medicine & PET, Rigshospitalet, Blegdamsvej 9, 2100 Copenhagen, Denmark
| | - Matthias M. Herth
- Department of Drug Design and Pharmacology, University of Copenhagen, Jagtvej 162, 2100 Copenhagen, Denmark;
- Department of Clinical Physiology, Nuclear Medicine & PET, Rigshospitalet, Blegdamsvej 9, 2100 Copenhagen, Denmark
| | | | - Gitte M. Knudsen
- Neurobiology Research Unit, Copenhagen University Hospital, Rigshospitalet, DK-2100 Copenhagen, Denmark; (H.H.H.); (H.D.H.); (E.T.L.); (G.M.K.)
| | - Jens D. Mikkelsen
- Neurobiology Research Unit, Copenhagen University Hospital, Rigshospitalet, DK-2100 Copenhagen, Denmark; (H.H.H.); (H.D.H.); (E.T.L.); (G.M.K.)
- Correspondence: (C.K.D.); (J.D.M.); Tel.: +45-40205378 (J.D.M)
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Yue X, Dhavale DD, Li J, Luo Z, Liu J, Yang H, Mach RH, Kotzbauer PT, Tu Z. Design, synthesis, and in vitro evaluation of quinolinyl analogues for α-synuclein aggregation. Bioorg Med Chem Lett 2018; 28:1011-1019. [PMID: 29482941 PMCID: PMC5870887 DOI: 10.1016/j.bmcl.2018.02.031] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2018] [Revised: 02/09/2018] [Accepted: 02/14/2018] [Indexed: 12/19/2022]
Abstract
Here we report the synthesis and in vitro evaluation of 25 new quinolinyl analogues for α-synuclein aggregates. Three lead compounds were subsequently labeled with carbon-11 or fluorine-18 to directly assess their potency in a direct radioactive competitive binding assay ng both α-synuclein fibrils and tissue homogenates from Alzheimer's disease (AD) cases. The modest binding affinities of these three radioligands toward α-synuclein were comparable with results from the Thioflavin T fluorescence assay. However, all three ligand also showed modest binding affinity to the AD homogenates and lack selectivity for α-synuclein. The structure-activity relationship data from these 25 analogues will provide useful information for design and synthesis of new compounds for imaging α-synuclein aggregation.
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Affiliation(s)
- Xuyi Yue
- Department of Radiology, Washington University School of Medicine, St Louis, MO, United States
| | - Dhruva D Dhavale
- Department of Neurology, Washington University School of Medicine, St Louis, MO, United States
| | - Junfeng Li
- Department of Radiology, Washington University School of Medicine, St Louis, MO, United States
| | - Zonghua Luo
- Department of Radiology, Washington University School of Medicine, St Louis, MO, United States
| | - Jialu Liu
- Department of Neurology, Washington University School of Medicine, St Louis, MO, United States
| | - Hao Yang
- Department of Radiology, Washington University School of Medicine, St Louis, MO, United States
| | - Robert H Mach
- Department of Radiology, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA, United States
| | - Paul T Kotzbauer
- Department of Neurology, Washington University School of Medicine, St Louis, MO, United States
| | - Zhude Tu
- Department of Radiology, Washington University School of Medicine, St Louis, MO, United States.
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10
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Potential of α7 nicotinic acetylcholine receptor PET imaging in atherosclerosis. Methods 2017; 130:90-104. [PMID: 28602809 DOI: 10.1016/j.ymeth.2017.06.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Revised: 06/02/2017] [Accepted: 06/06/2017] [Indexed: 02/07/2023] Open
Abstract
Atherosclerotic events are usually acute and often strike otherwise asymptomatic patients. Although multiple clinical risk factors have been associated with atherosclerosis, as of yet no further individual prediction can be made as to who will suffer from its consequences based on biomarker analysis or traditional imaging methods like CT, MRI or angiography. Previously, non-invasive imaging with 18F-fluorodeoxyglucose (18F-FDG) PET was shown to potentially fill this niche as it offers high sensitive detection of metabolic processes associated with inflammatory changes in atherosclerotic plaques. However, 18F-FDG PET imaging of arterial vessels suffers from non-specificity and has still to be proven to reliably identify vulnerable plaques, carrying a high risk of rupture. Therefore, it may be regarded only as a secondary marker for monitoring treatment effects and it does not offer alternative treatment options or direct insight in treatment mechanisms. In this review, an overview is given of the current status and the potential of PET imaging of inflammation and angiogenesis in atherosclerosis in general and special emphasis is given to imaging of α7 nicotinic acetylcholine receptors (α7 nAChRs). Due to the gaps that still exist in our understanding of atherogenesis and the limitations of the available PET tracers, the search continues for a more specific radioligand, able to differentiate between stable atherosclerosis and plaques prone to rupture. The potential role of the α7 nAChR as imaging marker for plaque vulnerability is explored. Today, strong evidence exists that nAChRs are involved in the atherosclerotic disease process. They are suggested to mediate the deleterious effects of the major tobacco component, nicotine, a nAChR agonist. Mainly based on in vitro data, α7 nAChR stimulation might increase plaque burden via increased neovascularization. However, in animal studies, α7 nAChR manipulation appears to reduce plaque size due to its inhibitory effects on inflammatory cells. Thus, reliable identification of α7 nAChRs by in vivo imaging is crucial to investigate the exact role of α7 nAChR in atherosclerosis before any therapeutic approach in the human setting can be justified. In this review, we discuss the first experience with α7 nAChR PET tracers and developmental considerations regarding the "optimal" PET tracer to image vascular nAChRs.
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Kassenbrock A, Vasdev N, Liang SH. Selected PET Radioligands for Ion Channel Linked Neuroreceptor Imaging: Focus on GABA, NMDA and nACh Receptors. Curr Top Med Chem 2017; 16:1830-42. [PMID: 26975506 DOI: 10.2174/1568026616666160315142457] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Revised: 08/01/2015] [Accepted: 08/03/2015] [Indexed: 12/11/2022]
Abstract
Positron emission tomography (PET) neuroimaging of ion channel linked receptors is a developing area of preclinical and clinical research. The present review focuses on recent advances with radiochemistry, preclinical and clinical PET imaging studies of three receptors that are actively pursued in neuropsychiatric drug discovery: namely the γ-aminobutyric acid-benzodiazapine (GABA) receptor, nicotinic acetylcholine receptor (nAChR), and N-methyl-D-aspartate (NMDA) receptor. Recent efforts to develop new PET radioligands for these targets with improved brain uptake, selectivity, stability and pharmacokinetics are highlighted.
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Affiliation(s)
| | | | - Steven H Liang
- Division of Nuclear Medicine and Molecular Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA.
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12
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van der Born D, Pees A, Poot AJ, Orru RVA, Windhorst AD, Vugts DJ. Fluorine-18 labelled building blocks for PET tracer synthesis. Chem Soc Rev 2017; 46:4709-4773. [DOI: 10.1039/c6cs00492j] [Citation(s) in RCA: 113] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
This review presents a comprehensive overview of the synthesis and application of fluorine-18 labelled building blocks since 2010.
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Affiliation(s)
- Dion van der Born
- Department of Radiology & Nuclear Medicine
- VU University Medical Center
- 1081 HV Amsterdam
- The Netherlands
| | - Anna Pees
- Department of Radiology & Nuclear Medicine
- VU University Medical Center
- 1081 HV Amsterdam
- The Netherlands
| | - Alex J. Poot
- Department of Radiology & Nuclear Medicine
- VU University Medical Center
- 1081 HV Amsterdam
- The Netherlands
| | - Romano V. A. Orru
- Department of Chemistry and Pharmaceutical Sciences and Amsterdam Institute for Molecules
- Medicines & Systems (AIMMS)
- VU University Amsterdam
- Amsterdam
- The Netherlands
| | - Albert D. Windhorst
- Department of Radiology & Nuclear Medicine
- VU University Medical Center
- 1081 HV Amsterdam
- The Netherlands
| | - Danielle J. Vugts
- Department of Radiology & Nuclear Medicine
- VU University Medical Center
- 1081 HV Amsterdam
- The Netherlands
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13
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Rötering S, Scheunemann M, Günther R, Löser R, Hiller A, Dan Peters, Brust P, Fischer S, Steinbach J. Tos-Nos-Mos: Synthesis of different aryl sulfonate precursors for the radiosynthesis of the alpha7 nicotinic acetylcholine receptor radioligand [18F]NS14490. Appl Radiat Isot 2016; 114:57-62. [DOI: 10.1016/j.apradiso.2016.04.028] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Revised: 04/09/2016] [Accepted: 04/27/2016] [Indexed: 10/21/2022]
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Abstract
During the past years, non-neuronal vascular nicotinic acetylcholine receptors (nAChRs) increasingly have gained interest in cardiovascular research, as they are known to mediate the deleterious effects of nicotine and nitrosamines, components of tobacco smoke, on the vasculature. Because smoking is a major risk factor for the development of atherosclerosis, it is obvious that understanding the pathophysiologic role of nAChRs in the atherosclerotic disease process, as well as in the development of new diagnostic and therapeutic nAChR-related options, has become more important. Accordingly, we briefly summarize the pathophysiologic role of vascular nAChRs in the atherosclerotic disease process. We also provide an overview of currently available nAChR positron emission tomography (PET) tracers and their performance in the noninvasive imaging of vascular nAChRs, as well as potential nAChR PET tracers that might be an option for vascular nAChR PET imaging in the future.
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Affiliation(s)
- Matthias Bauwens
- Department of Nuclear Medicine, Maastricht University Medical Center (MUMC+), Maastricht, The Netherlands
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15
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Chalon S, Vercouillie J, Guilloteau D, Suzenet F, Routier S. PET tracers for imaging brain α7 nicotinic receptors: an update. Chem Commun (Camb) 2016; 51:14826-31. [PMID: 26359819 DOI: 10.1039/c5cc04536c] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Positron emission tomography (PET) molecular imaging of brain targets is a powerful tool to diagnose, follow up, and develop treatments and personalized medicine for a number of acute and chronic brain disorders. The availability of β+ emitter tracers labelled with [(11)C] or [(18)F] having optimal characteristics of affinity and selectivity for alpha-7 nicotinic receptors (α7R) has received considerable attention, due to the major implication of these receptors in brain functions. The aim of this review is to identify the interest and need for the in vivo exploration of α7R by PET molecular imaging, which tools are currently available for this and how to progress.
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Affiliation(s)
- S Chalon
- UMR Inserm U930, Université François-Rabelais de Tours, F-37000 Tours, France.
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16
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Wenzel B, Mollitor J, Deuther-Conrad W, Dukic-Stefanovic S, Kranz M, Vraka C, Teodoro R, Günther R, Donat CK, Ludwig FA, Fischer S, Smits R, Wadsak W, Mitterhauser M, Steinbach J, Hoepping A, Brust P. Development of a Novel Nonpeptidic 18F-Labeled Radiotracer for in Vivo Imaging of Oxytocin Receptors with Positron Emission Tomography. J Med Chem 2016; 59:1800-17. [DOI: 10.1021/acs.jmedchem.5b01080] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Barbara Wenzel
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Research Site Leipzig, Department of Neuroradiopharmaceuticals,, Permoserstr. 15, 04318 Leipzig, Germany
| | - Jan Mollitor
- ABX Advanced Biochemical Compounds GmbH, 01454 Radeberg, Germany
| | - Winnie Deuther-Conrad
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Research Site Leipzig, Department of Neuroradiopharmaceuticals,, Permoserstr. 15, 04318 Leipzig, Germany
| | - Sladjana Dukic-Stefanovic
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Research Site Leipzig, Department of Neuroradiopharmaceuticals,, Permoserstr. 15, 04318 Leipzig, Germany
| | - Mathias Kranz
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Research Site Leipzig, Department of Neuroradiopharmaceuticals,, Permoserstr. 15, 04318 Leipzig, Germany
| | - Chrysoula Vraka
- Radiopharmacy
and Experimental Nuclear Medicine, Division of Nuclear Medicine, Medical University of Vienna, A-1090 Vienna, Austria
| | - Rodrigo Teodoro
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Research Site Leipzig, Department of Neuroradiopharmaceuticals,, Permoserstr. 15, 04318 Leipzig, Germany
| | - Robert Günther
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Research Site Leipzig, Department of Neuroradiopharmaceuticals,, Permoserstr. 15, 04318 Leipzig, Germany
| | - Cornelius K. Donat
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Research Site Leipzig, Department of Neuroradiopharmaceuticals,, Permoserstr. 15, 04318 Leipzig, Germany
| | - Friedrich-Alexander Ludwig
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Research Site Leipzig, Department of Neuroradiopharmaceuticals,, Permoserstr. 15, 04318 Leipzig, Germany
| | - Steffen Fischer
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Research Site Leipzig, Department of Neuroradiopharmaceuticals,, Permoserstr. 15, 04318 Leipzig, Germany
| | - Rene Smits
- ABX Advanced Biochemical Compounds GmbH, 01454 Radeberg, Germany
| | - Wolfgang Wadsak
- Radiopharmacy
and Experimental Nuclear Medicine, Division of Nuclear Medicine, Medical University of Vienna, A-1090 Vienna, Austria
| | - Markus Mitterhauser
- Radiopharmacy
and Experimental Nuclear Medicine, Division of Nuclear Medicine, Medical University of Vienna, A-1090 Vienna, Austria
| | - Jörg Steinbach
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Research Site Leipzig, Department of Neuroradiopharmaceuticals,, Permoserstr. 15, 04318 Leipzig, Germany
| | | | - Peter Brust
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Research Site Leipzig, Department of Neuroradiopharmaceuticals,, Permoserstr. 15, 04318 Leipzig, Germany
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17
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Teodoro R, Scheunemann M, Deuther-Conrad W, Wenzel B, Fasoli FM, Gotti C, Kranz M, Donat CK, Patt M, Hillmer A, Zheng MQ, Peters D, Steinbach J, Sabri O, Huang Y, Brust P. A Promising PET Tracer for Imaging of α₇ Nicotinic Acetylcholine Receptors in the Brain: Design, Synthesis, and in Vivo Evaluation of a Dibenzothiophene-Based Radioligand. Molecules 2015; 20:18387-421. [PMID: 26473809 PMCID: PMC6332508 DOI: 10.3390/molecules201018387] [Citation(s) in RCA: 12] [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: 07/15/2015] [Revised: 09/25/2015] [Accepted: 09/28/2015] [Indexed: 01/22/2023] Open
Abstract
Changes in the expression of α7 nicotinic acetylcholine receptors (α7 nAChRs) in the human brain are widely assumed to be associated with neurological and neurooncological processes. Investigation of these receptors invivo depends on the availability of imaging agents such as radioactively labelled ligands applicable in positron emission tomography (PET). We report on a series of new ligands for α7 nAChRs designed by the combination of dibenzothiophene dioxide as a novel hydrogen bond acceptor functionality with diazabicyclononane as an established cationic center. To assess the structure-activity relationship (SAR) of this new basic structure, we further modified the cationic center systematically by introduction of three different piperazine-based scaffolds. Based on invitro binding affinity and selectivity, assessed by radioligand displacement studies at different rat and human nAChR subtypes and at the structurally related human 5-HT3 receptor, we selected the compound 7-(1,4-diazabicyclo[3.2.2]nonan-4-yl)-2-fluorodibenzo-[b,d]thiophene 5,5-dioxide (10a) for radiolabeling and further evaluation invivo. Radiosynthesis of [18F]10a was optimized and transferred to an automated module. Dynamic PET imaging studies with [18F]10a in piglets and a monkey demonstrated high uptake of radioactivity in the brain, followed by washout and target-region specific accumulation under baseline conditions. Kinetic analysis of [18F]10a in pig was performed using a two-tissue compartment model with arterial-derived input function. Our initial evaluation revealed that the dibenzothiophene-based PET radioligand [18F]10a ([18F]DBT-10) has high potential to provide clinically relevant information about the expression and availability of α7 nAChR in the brain.
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Affiliation(s)
- Rodrigo Teodoro
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Permoserstraße 15, Leipzig 04318, Germany.
| | - Matthias Scheunemann
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Permoserstraße 15, Leipzig 04318, Germany.
| | - Winnie Deuther-Conrad
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Permoserstraße 15, Leipzig 04318, Germany.
| | - Barbara Wenzel
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Permoserstraße 15, Leipzig 04318, Germany.
| | - Francesca Maria Fasoli
- Consiglio Nazionale delle Ricerche, Institute of Neuroscience, Biometra-Institute University of Milan, Via Luigi Vanvitelli 32, Milano 20129, Italy.
| | - Cecilia Gotti
- Consiglio Nazionale delle Ricerche, Institute of Neuroscience, Biometra-Institute University of Milan, Via Luigi Vanvitelli 32, Milano 20129, Italy.
| | - Mathias Kranz
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Permoserstraße 15, Leipzig 04318, Germany.
| | - Cornelius K Donat
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Permoserstraße 15, Leipzig 04318, Germany.
| | - Marianne Patt
- Department of Nuclear Medicine, University Hospital Leipzig, Liebigstraße 18, Leipzig 04103, Germany.
| | - Ansel Hillmer
- PET Center, Yale University, P.O. Box 208048, 801 Howard Avenue, New Haven, CT 06520-8048, USA.
| | - Ming-Qiang Zheng
- PET Center, Yale University, P.O. Box 208048, 801 Howard Avenue, New Haven, CT 06520-8048, USA.
| | - Dan Peters
- Dan PET AB, Rosenstigen 7, Malmö SE-21619, Sweden.
| | - Jörg Steinbach
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Permoserstraße 15, Leipzig 04318, Germany.
| | - Osama Sabri
- Department of Nuclear Medicine, University Hospital Leipzig, Liebigstraße 18, Leipzig 04103, Germany.
| | - Yiyun Huang
- PET Center, Yale University, P.O. Box 208048, 801 Howard Avenue, New Haven, CT 06520-8048, USA.
| | - Peter Brust
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Permoserstraße 15, Leipzig 04318, Germany.
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18
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Wu A, Li X, Xue Q, Liu Y, Lu X, Yan X, Zhang H. Radio synthesis and in vivo evaluation of two α7 nAChRs radioligands: [125I]CAIPE and [125I]IPPU. J Radioanal Nucl Chem 2015. [DOI: 10.1007/s10967-015-4235-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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19
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Kniess T, Laube M, Brust P, Steinbach J. 2-[18F]Fluoroethyl tosylate – a versatile tool for building18F-based radiotracers for positron emission tomography. MEDCHEMCOMM 2015. [DOI: 10.1039/c5md00303b] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The review highlights the role of 2-[18F]fluoroethyltosylate ([18F]FETs) in PET radiotracer design since it is a preferred labeling reagent according to its high reactivity to phenolic, amine, thiophenolic and carboxylic functions.
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Affiliation(s)
- Torsten Kniess
- Helmholtz-Zentrum Dresden-Rossendorf
- Institute of Radiopharmaceutical Cancer Research
- Dresden
- Germany
| | - Markus Laube
- Helmholtz-Zentrum Dresden-Rossendorf
- Institute of Radiopharmaceutical Cancer Research
- Dresden
- Germany
| | - Peter Brust
- Helmholtz-Zentrum Dresden-Rossendorf
- Institute of Radiopharmaceutical Cancer Research
- Dresden
- Germany
| | - Jörg Steinbach
- Helmholtz-Zentrum Dresden-Rossendorf
- Institute of Radiopharmaceutical Cancer Research
- Dresden
- Germany
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20
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Teodoro R, Wenzel B, Oh-Nishi A, Fischer S, Peters D, Suhara T, Deuther-Conrad W, Brust P. A high-yield automated radiosynthesis of the alpha-7 nicotinic receptor radioligand [ 18F]NS10743. Appl Radiat Isot 2014; 95:76-84. [PMID: 25464181 DOI: 10.1016/j.apradiso.2014.09.016] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Revised: 09/16/2014] [Accepted: 09/29/2014] [Indexed: 01/30/2023]
Abstract
[18F]NS10743, a promising and highly competitive α7 nAChR radioligand has been synthesized so far by microwave irradiation using a manual single-mode device followed by a palladium-catalyzed reduction of remaining nitro-precursor for HPLC separation purposes. For further preclinical and clinical use, regulated production of [18F]NS10743 by fully automated radiosynthesis is a crucial requirement. Therefore, we chose a commercial synthesis module and developed the automated radiosynthesis of [18F]NS10743. Besides evaluation of several radiosynthesis procedures, we performed an extensive HPLC study for quantitative separation of [18F]NS10743 from the corresponding nitro precursor. After implementation of the optimized procedure on a TRACERlabTM FX F-N synthesis module, [18F]NS10743 was obtained in high radiochemical purity (≥99%) with an overall radiochemical yield of 32.2±7% (n=3). The specific activities at the end of the synthesis were 571±17GBq/µmol (n=3).
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Affiliation(s)
- Rodrigo Teodoro
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Research Site Leipzig, Germany.
| | - Barbara Wenzel
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Research Site Leipzig, Germany
| | - Arata Oh-Nishi
- Molecular Neuroimaging Program, Molecular Imaging Center, National Institute of Radiological Sciences, Inage-ku, Chiba, Japan
| | - Steffen Fischer
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Research Site Leipzig, Germany
| | | | - Tetsuya Suhara
- Molecular Neuroimaging Program, Molecular Imaging Center, National Institute of Radiological Sciences, Inage-ku, Chiba, Japan
| | - Winnie Deuther-Conrad
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Research Site Leipzig, Germany
| | - Peter Brust
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Research Site Leipzig, Germany
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21
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Development of (18)F-labeled radiotracers for neuroreceptor imaging with positron emission tomography. Neurosci Bull 2014; 30:777-811. [PMID: 25172118 DOI: 10.1007/s12264-014-1460-6] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2014] [Accepted: 06/02/2014] [Indexed: 12/14/2022] Open
Abstract
Positron emission tomography (PET) is an in vivo molecular imaging tool which is widely used in nuclear medicine for early diagnosis and treatment follow-up of many brain diseases. PET uses biomolecules as probes which are labeled with radionuclides of short half-lives, synthesized prior to the imaging studies. These probes are called radiotracers. Fluorine-18 is a radionuclide routinely used in the radiolabeling of neuroreceptor ligands for PET because of its favorable half-life of 109.8 min. The delivery of such radiotracers into the brain provides images of transport, metabolic, and neurotransmission processes on the molecular level. After a short introduction into the principles of PET, this review mainly focuses on the strategy of radiotracer development bridging from basic science to biomedical application. Successful radiotracer design as described here provides molecular probes which not only are useful for imaging of human brain diseases, but also allow molecular neuroreceptor imaging studies in various small-animal models of disease, including genetically-engineered animals. Furthermore, they provide a powerful tool for in vivo pharmacology during the process of pre-clinical drug development to identify new drug targets, to investigate pathophysiology, to discover potential drug candidates, and to evaluate the pharmacokinetics and pharmacodynamics of drugs in vivo.
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22
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Rötering S, Deuther-Conrad W, Cumming P, Donat CK, Scheunemann M, Fischer S, Xiong G, Steinbach J, Peters D, Sabri O, Bucerius J, Brust P. Imaging of α7 nicotinic acetylcholine receptors in brain and cerebral vasculature of juvenile pigs with [(18)F]NS14490. EJNMMI Res 2014; 4:43. [PMID: 25136512 PMCID: PMC4129469 DOI: 10.1186/s13550-014-0043-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Accepted: 07/17/2014] [Indexed: 11/21/2022] Open
Abstract
Background The α7 nicotinic acetylcholine receptor (nAChR) is an important molecular target in neuropsychiatry and oncology. Development of applicable highly specific radiotracers has been challenging due to comparably low protein expression. To identify novel ligands as candidates for positron emission tomography (PET), a library of diazabicyclononane compounds was screened regarding affinity and specificity towards α7 nAChRs. From these, [18F]NS14490 has been shown to yield reliable results in organ distribution studies; however, the radiosynthesis of [18F]NS14490 required optimization and automation to obtain the radiotracer in quantities allowing dynamic PET studies in piglets. Methods Automated radiosynthesis of [18F]NS14490 has been performed by [18F]fluorination with the tosylate precursor in the TRACERlab™ FX F-N synthesis module (Waukesha, WI, USA). After optimization, the radiochemical yield of [18F]NS14490 was consistently approximately 35%, and the total synthesis time was about 90 min. The radiotracer was prepared with >92% radiochemical purity, and the specific activity at the end of the synthesis was 226 ± 68 GBq μmol−1. PET measurements were performed in young pigs to investigate the metabolic stability and cerebral binding of [18F]NS14490 without and with administration of the α7 nAChR partial agonist NS6740 in baseline and blocking conditions. Results The total distribution volume relative to the metabolite-corrected arterial input was 3.5 to 4.0 mL g−1 throughout the telencephalon and was reduced to 2.6 mL g−1 in animals treated with NS6740. Assuming complete blockade, this displacement indicated a binding potential (BPND) of approximately 0.5 in the brain of living pigs. In addition, evidence for specific binding in major brain arteries has been obtained. Conclusion [18F]NS14490 is not only comparable to other preclinically investigated PET radiotracers for imaging of α7 nAChR in brain but also could be a potential PET radiotracer for imaging of α7 nAChR in vulnerable plaques of diseased vessels.
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Affiliation(s)
- Sven Rötering
- Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf, Permoserstr. 15, Leipzig 04318, Germany
| | - Winnie Deuther-Conrad
- Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf, Permoserstr. 15, Leipzig 04318, Germany
| | - Paul Cumming
- Department of Nuclear Medicine, Friedrich-Alexander-Universität, Ulmenweg 18, Erlangen 91054, Germany ; Department of Pharmacology and Neuroscience, Copenhagen University, Blegdamsvej 3B, Copenhagen 2200, Denmark
| | - Cornelius K Donat
- Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf, Permoserstr. 15, Leipzig 04318, Germany
| | - Matthias Scheunemann
- Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf, Permoserstr. 15, Leipzig 04318, Germany
| | - Steffen Fischer
- Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf, Permoserstr. 15, Leipzig 04318, Germany
| | - Guoming Xiong
- Department of Nuclear Medicine, Ludwig-Maximilians-Universität, Marchioninistr. 15, Munich 83177, Germany
| | - Jörg Steinbach
- Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf, Permoserstr. 15, Leipzig 04318, Germany
| | - Dan Peters
- DanPET AB, Rosenstigen 7, Malmö SE-21619, Sweden
| | - Osama Sabri
- Department of Nuclear Medicine, Universität Leipzig, Liebigstr. 18, Leipzig 04103, Germany
| | - Jan Bucerius
- Department of Nuclear Medicine, Maastricht University Medical Center, P. Debeylaan 25, Maastricht 6229, The Netherlands ; Cardiovascular Research Institute Maastricht (CARIM), Maastricht University Medical Center, P. Debeylaan 25, Maastricht 6229, The Netherlands ; Department of Nuclear Medicine, University Hospital RWTH Aachen, Pauwelstr. 30, Aachen 52074, Germany
| | - Peter Brust
- Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf, Permoserstr. 15, Leipzig 04318, Germany
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Design of α7 nicotinic acetylcholine receptor ligands in quinuclidine, tropane and quinazoline series. Chemistry, molecular modeling, radiochemistry, in vitro and in rats evaluations of a [18F] quinuclidine derivative. Eur J Med Chem 2014; 82:214-24. [DOI: 10.1016/j.ejmech.2014.04.057] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2014] [Revised: 04/17/2014] [Accepted: 04/19/2014] [Indexed: 12/23/2022]
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Teodoro R, Moldovan RP, Lueg C, Günther R, Donat CK, Ludwig FA, Fischer S, Deuther-Conrad W, Wünsch B, Brust P. Radiofluorination and biological evaluation of N-aryl-oxadiazolyl-propionamides as potential radioligands for PET imaging of cannabinoid CB2 receptors. Org Med Chem Lett 2013; 3:11. [PMID: 24063584 PMCID: PMC3856494 DOI: 10.1186/2191-2858-3-11] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Accepted: 09/15/2013] [Indexed: 11/10/2022] Open
Abstract
Background The level of expression of cannabinoid receptor type 2 (CB2R) in healthy and diseased brain has not been fully elucidated. Therefore, there is a growing interest to assess the regional expression of CB2R in the brain. Positron emission tomography (PET) is an imaging technique, which allows quantitative monitoring of very low amounts of radiolabelled compounds in living organisms at high temporal and spatial resolution and, thus, has been widely used as a diagnostic tool in nuclear medicine. Here, we report on the radiofluorination of N-aryl-oxadiazolyl-propionamides at two different positions in the lead structure and on the biological evaluation of the potential of the two tracers [18F]1 and [18F]2 as CB2 receptor PET imaging agents. Results High binding affinity and specificity towards CB2 receptors of the lead structure remained unaffected by the structural changes such as the insertion of the aliphatic and aromatic fluorine in the selected labelling sites of 1 and 2. Aliphatic and aromatic radiofluorinations were optimized, and [18F]1 and [18F]2 were achieved in radiochemical yields of ≥30% with radiochemical purities of ≥98% and specific activities of 250 to 450 GBq/μmol. Organ distribution studies in female CD1 mice revealed that both radiotracers cross the blood–brain barrier (BBB) but undergo strong peripheral metabolism. At 30 min after injection, unmetabolized [18F]1 and [18F]2 accounted for 60% and 2% as well as 68% and 88% of the total activity in the plasma and brain, respectively. The main radiometabolite of [18F]2 could be identified as the free acid [18F]10, which has no affinity towards the CB1 and CB2 receptors but can cross the BBB. Conclusions N-aryl-oxadiazolyl-propionamides can successfully be radiolabelled with 18F at different positions. Fluorine substitution at these positions did not affect affinity and specificity towards CB2R. Despite a promising in vitro behavior, a rather rapid peripheral metabolism of [18F]1 and [18F]2 in mice and the generation of brain permeable radiometabolites hamper the application of these radiotracers in vivo. However, it is expected that future synthetic modification aiming at a replacement of metabolically susceptible structural elements of [18F]1 and [18F]2 will help to elucidate the potential of this class of compounds for CB2R PET studies.
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Affiliation(s)
- Rodrigo Teodoro
- Department of Pharmaceutical and Medicinal Chemistry, University of Münster, Corrensstraße 58-62, 48149 Münster, Germany.
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25
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Gao Y, Kellar KJ, Yasuda RP, Tran T, Xiao Y, Dannals RF, Horti AG. Derivatives of dibenzothiophene for positron emission tomography imaging of α7-nicotinic acetylcholine receptors. J Med Chem 2013; 56:7574-89. [PMID: 24050653 DOI: 10.1021/jm401184f] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
A new series of derivatives of 3-(1,4-diazabicyclo[3.2.2]nonan-4-yl)dibenzo[b,d]thiophene 5,5-dioxide with high binding affinities and selectivity for α7-nicotinic acetylcholine receptors (α7-nAChRs) (Ki = 0.4-20 nM) has been synthesized for positron emission tomography (PET) imaging of α7-nAChRs. Two radiolabeled members of the series [(18)F]7a (Ki = 0.4 nM) and [(18)F]7c (Ki = 1.3 nM) were synthesized. [(18)F]7a and [(18)F]7c readily entered the mouse brain and specifically labeled α7-nAChRs. The α7-nAChR selective ligand 1 (SSR180711) blocked the binding of [(18)F]7a in the mouse brain in a dose-dependent manner. The mouse blocking studies with non-α7-nAChR central nervous system drugs demonstrated that [(18)F]7a is highly α7-nAChR selective. In agreement with its binding affinity the binding potential of [(18)F]7a (BPND = 5.3-8.0) in control mice is superior to previous α7-nAChR PET radioligands. Thus, [(18)F]7a displays excellent imaging properties in mice and has been chosen for further evaluation as a potential PET radioligand for imaging of α7-nAChR in non-human primates.
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Affiliation(s)
- Yongjun Gao
- Russell H. Morgan Department of Radiology and Radiological Sciences, Division of Nuclear Medicine, The Johns Hopkins University School of Medicine , 600 North Wolfe Street, Baltimore, Maryland 21287-0816, United States
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