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Froudist-Walsh S, Xu T, Niu M, Rapan L, Zhao L, Margulies DS, Zilles K, Wang XJ, Palomero-Gallagher N. Gradients of neurotransmitter receptor expression in the macaque cortex. Nat Neurosci 2023; 26:1281-1294. [PMID: 37336976 PMCID: PMC10322721 DOI: 10.1038/s41593-023-01351-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Accepted: 05/01/2023] [Indexed: 06/21/2023]
Abstract
Dynamics and functions of neural circuits depend on interactions mediated by receptors. Therefore, a comprehensive map of receptor organization across cortical regions is needed. In this study, we used in vitro receptor autoradiography to measure the density of 14 neurotransmitter receptor types in 109 areas of macaque cortex. We integrated the receptor data with anatomical, genetic and functional connectivity data into a common cortical space. We uncovered a principal gradient of receptor expression per neuron. This aligns with the cortical hierarchy from sensory cortex to higher cognitive areas. A second gradient, driven by serotonin 5-HT1A receptors, peaks in the anterior cingulate, default mode and salience networks. We found a similar pattern of 5-HT1A expression in the human brain. Thus, the macaque may be a promising translational model of serotonergic processing and disorders. The receptor gradients may enable rapid, reliable information processing in sensory cortical areas and slow, flexible integration in higher cognitive areas.
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MESH Headings
- Aged
- Animals
- Female
- Humans
- Male
- Rats
- Autoradiography
- Brain Mapping
- Cerebral Cortex/cytology
- Cerebral Cortex/metabolism
- Cognition
- Dendritic Spines
- Gyrus Cinguli/cytology
- Gyrus Cinguli/metabolism
- Macaca fascicularis
- Rats, Inbred Lew
- Receptor, Serotonin, 5-HT1A/analysis
- Receptor, Serotonin, 5-HT1A/metabolism
- Receptors, Cholinergic/analysis
- Receptors, Cholinergic/metabolism
- Receptors, Dopamine/analysis
- Receptors, Dopamine/metabolism
- Receptors, Neurotransmitter/analysis
- Receptors, Neurotransmitter/metabolism
- Serotonin/metabolism
- Species Specificity
- Myelin Sheath/metabolism
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Affiliation(s)
- Sean Froudist-Walsh
- Computational Neuroscience Unit, Faculty of Engineering, University of Bristol, Bristol, UK
- Center for Neural Science, New York University, New York, NY, USA
| | - Ting Xu
- Child Mind Institute, New York, NY, USA
| | - Meiqi Niu
- Institute of Neuroscience and Medicine (INM-1), Research Centre Jülich, Jülich, Germany
| | - Lucija Rapan
- Institute of Neuroscience and Medicine (INM-1), Research Centre Jülich, Jülich, Germany
| | - Ling Zhao
- Institute of Neuroscience and Medicine (INM-1), Research Centre Jülich, Jülich, Germany
| | - Daniel S Margulies
- Integrative Neuroscience and Cognition Center, University of Paris Cité, Paris, France
| | | | - Xiao-Jing Wang
- Center for Neural Science, New York University, New York, NY, USA
| | - Nicola Palomero-Gallagher
- Institute of Neuroscience and Medicine (INM-1), Research Centre Jülich, Jülich, Germany.
- Cécile and Oskar Vogt Institute for Brain Research, Medical Faculty, University Hospital Düsseldorf, Heinrich Heine University Düsseldorf, Düsseldorf, Germany.
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2
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Fu H, Rong J, Chen Z, Zhou J, Collier T, Liang SH. Positron Emission Tomography (PET) Imaging Tracers for Serotonin Receptors. J Med Chem 2022; 65:10755-10808. [PMID: 35939391 DOI: 10.1021/acs.jmedchem.2c00633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Serotonin (5-hydroxytryptamine, 5-HT) and 5-HT receptors (5-HTRs) have crucial roles in various neuropsychiatric disorders and neurodegenerative diseases, making them attractive diagnostic and therapeutic targets. Positron emission tomography (PET) is a noninvasive nuclear molecular imaging technique and is an essential tool in clinical diagnosis and drug discovery. In this context, numerous PET ligands have been developed for "visualizing" 5-HTRs in the brain and translated into human use to study disease mechanisms and/or support drug development. Herein, we present a comprehensive repertoire of 5-HTR PET ligands by focusing on their chemotypes and performance in PET imaging studies. Furthermore, this Perspective summarizes recent 5-HTR-focused drug discovery, including biased agonists and allosteric modulators, which would stimulate the development of more potent and subtype-selective 5-HTR PET ligands and thus further our understanding of 5-HTR biology.
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Affiliation(s)
- Hualong Fu
- Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, China
| | - Jian Rong
- Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital, Boston, Massachusetts 02114, United States.,Department of Radiology, Harvard Medical School, Boston, Massachusetts 02115, United States
| | - Zhen Chen
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, 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
| | - Thomas Collier
- Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital, Boston, Massachusetts 02114, United States.,Department of Radiology, Harvard Medical School, Boston, Massachusetts 02115, United States
| | - Steven H Liang
- Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital, Boston, Massachusetts 02114, United States.,Department of Radiology, Harvard Medical School, Boston, Massachusetts 02115, United States
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3
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Mangeant R, Dubost E, Cailly T, Collot V. Radiotracers for the Central Serotoninergic System. Pharmaceuticals (Basel) 2022; 15:ph15050571. [PMID: 35631397 PMCID: PMC9143978 DOI: 10.3390/ph15050571] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Revised: 04/27/2022] [Accepted: 04/28/2022] [Indexed: 12/10/2022] Open
Abstract
This review lists the most important radiotracers described so far for imaging the central serotoninergic system. Single-photon emission computed tomography and positron emission tomography radiotracers are reviewed and critically discussed for each receptor.
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Affiliation(s)
- Reynald Mangeant
- Centre d’Etudes et de Recherche sur le Médicament de Normandie (CERMN), UNICAEN, Normandie Univ., 14000 Caen, France; (R.M.); (E.D.)
- Institut Blood and Brain @ Caen Normandie (BB@C), Boulevard Henri Becquerel, 14000 Caen, France
| | - Emmanuelle Dubost
- Centre d’Etudes et de Recherche sur le Médicament de Normandie (CERMN), UNICAEN, Normandie Univ., 14000 Caen, France; (R.M.); (E.D.)
- Institut Blood and Brain @ Caen Normandie (BB@C), Boulevard Henri Becquerel, 14000 Caen, France
| | - Thomas Cailly
- Centre d’Etudes et de Recherche sur le Médicament de Normandie (CERMN), UNICAEN, Normandie Univ., 14000 Caen, France; (R.M.); (E.D.)
- Institut Blood and Brain @ Caen Normandie (BB@C), Boulevard Henri Becquerel, 14000 Caen, France
- UNICAEN, IMOGERE, Normandie Univ., 14000 Caen, France
- CHU Côte de Nacre, Department of Nuclear Medicine, 14000 Caen, France
- Correspondence: (T.C.); (V.C.)
| | - Valérie Collot
- Centre d’Etudes et de Recherche sur le Médicament de Normandie (CERMN), UNICAEN, Normandie Univ., 14000 Caen, France; (R.M.); (E.D.)
- Institut Blood and Brain @ Caen Normandie (BB@C), Boulevard Henri Becquerel, 14000 Caen, France
- Correspondence: (T.C.); (V.C.)
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4
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Hazari PP, Pandey A, Chaturvedi S, Mishra AK. New Trends and Current Status of Positron-Emission Tomography and Single-Photon-Emission Computerized Tomography Radioligands for Neuronal Serotonin Receptors and Serotonin Transporter. Bioconjug Chem 2017; 28:2647-2672. [PMID: 28767225 DOI: 10.1021/acs.bioconjchem.7b00243] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The critical role of serotonin (5-hydroxytryptamine; 5-HT) and its receptors (5-HTRs) in the pathophysiology of diverse neuropsychiatric and neurodegenerative disorders render them attractive diagnostic and therapeutic targets for brain disorders. Therefore, the in vivo assessment of binding of 5-HT receptor ligands under a multitude of physiologic and pathologic scenarios may support more-accurate identification of disease and its progression and the patient's response to therapy as well as the screening of novel therapeutic strategies. The present Review aims to focus on the current status of radioligands used for positron-emission tomography (PET) and single-photon-emission computerized tomography (SPECT) imaging of human brain serotonin receptors. We further elaborate upon and emphasize the attributes that qualify a radioligand for theranostics on the basis of its frequency of use in clinics, its benefit to risk assessment in humans, and its continuous evolution, along with the major limitations.
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Affiliation(s)
- Puja Panwar Hazari
- Division of Cyclotron and Radiopharmaceutical Sciences, Institute of Nuclear Medicine and Allied Sciences , Brig S.K. Mazumdar Road, Delhi 110054, India
| | - Ankita Pandey
- Division of Cyclotron and Radiopharmaceutical Sciences, Institute of Nuclear Medicine and Allied Sciences , Brig S.K. Mazumdar Road, Delhi 110054, India
| | - Shubhra Chaturvedi
- Division of Cyclotron and Radiopharmaceutical Sciences, Institute of Nuclear Medicine and Allied Sciences , Brig S.K. Mazumdar Road, Delhi 110054, India
| | - Anil Kumar Mishra
- Division of Cyclotron and Radiopharmaceutical Sciences, Institute of Nuclear Medicine and Allied Sciences , Brig S.K. Mazumdar Road, Delhi 110054, India
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5
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García G, Abet V, Alajarín R, Álvarez-Builla J, Delgado M, García-García L, Bascuñana-Almarcha P, Peña-Salcedo C, Kelly J, Pozo MA. N-(4-[(18)F]-fluoropyridin-2-yl)-N-{2-[4-(2-methoxyphenyl)piperazin-1-yl]ethyl}carboxamides as analogs of WAY100635. New PET tracers of serotonin 5-HT(1A) receptors. Eur J Med Chem 2014; 85:795-806. [PMID: 25171752 DOI: 10.1016/j.ejmech.2014.07.096] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2014] [Revised: 07/24/2014] [Accepted: 07/25/2014] [Indexed: 10/25/2022]
Abstract
N-(4-[(18)F]-Fluoropyridin-2-yl)-N-{2-[4-(2-methoxyphenyl)piperazin-1-yl]ethyl}-carboxamides were prepared by labeling their 4-nitropyridin-2-yl precursors through nitro substitution by the (18)F anion. In vitro and in vivo tests showed that the cyclohexanecarboxamide derivative is a reversible, selective and high affinity 5-HT1A receptor antagonist (IC50 = 0.29 nM, ki = 0.18 nM) with high brain uptake, slow brain clearance and stability to defluorination when compared with conventional standards. This PET radioligand is a promising candidate for an improved in vivo quantification of 5-HT1A receptors in neuropsychiatric disorders.
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Affiliation(s)
- Gonzalo García
- Departamento de Química Orgánica, Universidad de Alcalá, Alcalá de Henares, Madrid 28871, Spain
| | - Valentina Abet
- Departamento de Química Orgánica, Universidad de Alcalá, Alcalá de Henares, Madrid 28871, Spain
| | - Ramón Alajarín
- Departamento de Química Orgánica, Universidad de Alcalá, Alcalá de Henares, Madrid 28871, Spain
| | - Julio Álvarez-Builla
- Departamento de Química Orgánica, Universidad de Alcalá, Alcalá de Henares, Madrid 28871, Spain.
| | - Mercedes Delgado
- CAI Cartografía Cerebral, Instituto Pluridisciplinar UCM, Paseo Juan XXIII, 1, Madrid 28040, Spain
| | - Luis García-García
- CAI Cartografía Cerebral, Instituto Pluridisciplinar UCM, Paseo Juan XXIII, 1, Madrid 28040, Spain
| | - Pablo Bascuñana-Almarcha
- CAI Cartografía Cerebral, Instituto Pluridisciplinar UCM, Paseo Juan XXIII, 1, Madrid 28040, Spain
| | - Carmen Peña-Salcedo
- Instituto Tecnológico PET, Calle Manuel Bartolomé Cossío 10, Madrid 28040, Spain
| | - James Kelly
- Instituto Tecnológico PET, Calle Manuel Bartolomé Cossío 10, Madrid 28040, Spain
| | - Miguel A Pozo
- CAI Cartografía Cerebral, Instituto Pluridisciplinar UCM, Paseo Juan XXIII, 1, Madrid 28040, Spain; Instituto Tecnológico PET, Calle Manuel Bartolomé Cossío 10, Madrid 28040, Spain.
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6
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Hazari PP, Schulz J, Vimont D, Chadha N, Allard M, Szlosek-Pinaud M, Fouquet E, Mishra AK. A new SiF-Dipropargyl glycerol scaffold as a versatile prosthetic group to design dimeric radioligands: synthesis of the [(18) F]BMPPSiF tracer to image serotonin receptors. ChemMedChem 2013; 9:337-49. [PMID: 24376058 DOI: 10.1002/cmdc.201300458] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2013] [Indexed: 11/12/2022]
Abstract
A novel SiX-dipropargyl glycerol scaffold (X: H, F, or (18) F) was developed as a versatile prosthetic group that provides technical advantages for the preparation of dimeric radioligands based on silicon fluoride acceptor pre- or post-labeling with fluorine-18. Rapid conjugation with the prosthetic group takes place in microwave-assisted click conjugation under mild conditions. Thus, a bivalent homodimeric SiX-dipropargyl glycerol derivatized radioligand, [(18) F]BMPPSiF, with enhanced affinity was developed by using click conjugation. High uptake of the radioligand was demonstrated in 5-HT1A receptor-rich regions in the brain with positron emission tomography. Molecular docking studies (rigid protein-flexible ligand) of BMPPSiF and known antagonists (WAY-100635, MPPF, and MefWAY) with monomeric, dimeric, and multimeric 5-HT1A receptor models were performed, with the highest G score obtained for docked BMPPSiF: -6.766 as compared with all three antagonists on the monomeric model. Multimeric induced-fit docking was also performed to visualize the comparable mode of binding under in vivo conditions, and a notably improved G score of -8.455 was observed for BMPPSiF. These data directly correlate the high binding potential of BMPPSiF with the bivalent binding mode obtained in the biological studies. The present study warrants wide application of the SiX-dipropargyl glycerol prosthetic group in the development of ligands for imaging with enhanced affinity markers for specific targeting based on peptides, nucleosides, and lipids.
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Affiliation(s)
- Puja Panwar Hazari
- Division of Cyclotron and Radiopharamceutical Sciences, Brig. SK Mazumdar Road, Delhi 110054 (India)
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7
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Choi JY, Kim CH, Ryu YH, Seo YB, Truong P, Kim EJ, Choi TH, Kang J, Lee M, Kim DG, Lee JD, Jeon TJ. Optimization of the radiosynthesis of [18F]MEFWAY for imaging brain serotonin 1A receptors by using the GE TracerLab FXFN-Promodule. J Labelled Comp Radiopharm 2013; 56:589-94. [DOI: 10.1002/jlcr.3067] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2013] [Revised: 04/12/2013] [Accepted: 05/06/2013] [Indexed: 11/10/2022]
Affiliation(s)
- Jae Yong Choi
- Department of Nuclear Medicine; Yonsei University College of Medicine, Gangnam Severance Hospital; Seoul 135-720 Korea
| | - Chul Hoon Kim
- Department of Pharmacology; Brain Research Institute, Brain Korea 21 Project for Medical Science, Yonsei University College of Medicine; Seoul 120-752 Korea
| | - Young Hoon Ryu
- Department of Nuclear Medicine; Yonsei University College of Medicine, Gangnam Severance Hospital; Seoul 135-720 Korea
| | - Young Beom Seo
- Department of Nuclear Medicine; Yonsei University College of Medicine, Gangnam Severance Hospital; Seoul 135-720 Korea
| | - Phong Truong
- Global Radiopharmacy Molecular Imaging Technologies; GE Healthcare; Husbyborg 15024 Uppsala Sweden
| | - Eun Jung Kim
- Department of Molecular Imaging; Korea Institute of Radiological & Medical Sciences; Seoul 139-706 Korea
| | - Tae Hyun Choi
- Department of Molecular Imaging; Korea Institute of Radiological & Medical Sciences; Seoul 139-706 Korea
| | - JeeHae Kang
- Swarthmore College; 500 College Avenue Swarthmore; PA 19081 USA
| | - Minkyung Lee
- Department of Nuclear Medicine; Yonsei University College of Medicine, Gangnam Severance Hospital; Seoul 135-720 Korea
| | - Dong Goo Kim
- Department of Pharmacology; Brain Research Institute, Brain Korea 21 Project for Medical Science, Yonsei University College of Medicine; Seoul 120-752 Korea
| | - Jong Doo Lee
- Department of Nuclear Medicine; Yonsei University College of Medicine, Gangnam Severance Hospital; Seoul 135-720 Korea
| | - Tae Joo Jeon
- Department of Nuclear Medicine; Yonsei University College of Medicine, Gangnam Severance Hospital; Seoul 135-720 Korea
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8
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Choi JY, Kim CH, Jeon TJ, Kim BS, Yi CH, Woo KS, Seo YB, Han SJ, Kim KM, Yi DI, Lee M, Kim DG, Kim JY, Lee KC, Choi TH, An G, Ryu YH. Effective MicroPET imaging of brain 5-HT1Areceptors in rats with [18F]MeFWAY by suppression of radioligand defluorination. Synapse 2012; 66:1015-23. [DOI: 10.1002/syn.21607] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2012] [Accepted: 08/21/2012] [Indexed: 11/11/2022]
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Abstract
The serotonergic system plays a key modulatory role in the brain and is the target for many drug treatments for brain disorders either through reuptake blockade or via interactions at the 14 subtypes of 5-HT receptors. This review provides the history and current status of radioligands used for positron emission tomography (PET) and single photon emission computerized tomography (SPECT) imaging of human brain serotonin (5-HT) receptors, the 5-HT transporter (SERT), and 5-HT synthesis rate. Currently available radioligands for in vivo brain imaging of the 5-HT system in humans include antagonists for the 5-HT(1A), 5-HT(1B), 5-HT(2A), and 5-HT(4) receptors, and for SERT. Here we describe the evolution of these radioligands, along with the attempts made to develop radioligands for additional serotonergic targets. We describe the properties needed for a radioligand to become successful and the main caveats. The success of a PET or SPECT radioligand can ultimately be assessed by its frequency of use, its utility in humans, and the number of research sites using it relative to its invention date, and so these aspects are also covered. In conclusion, the development of PET and SPECT radioligands to image serotonergic targets is of high interest, and successful evaluation in humans is leading to invaluable insight into normal and abnormal brain function, emphasizing the need for continued development of both SPECT and PET radioligands for human brain imaging.
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Affiliation(s)
- Louise M Paterson
- Neuropsychopharmacology Unit, Division of Experimental Medicine, Imperial College London, Burlington Danes Building, Du Cane Road, London, United Kingdom
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Abstract
Molecular in vivo neuroimaging techniques can be used to measure regional changes in endogenous neurotransmitters, evoked by challenges that alter synaptic neurotransmitter concentration. This technique has most successfully been applied to the study of endogenous dopamine release using positron emission tomography, but has not yet been adequately extended to other neurotransmitter systems. This review focuses on how the technique has been applied to the study of the 5-hydroxytryptamine (5-HT) system. The principles behind visualising fluctuations in neurotransmitters are introduced, with reference to the dopaminergic system. Studies that aim to image acute, endogenous 5-HT release or depletion at 5-HT receptor targets are summarised, with particular attention to studies in humans. Radiotracers targeting the 5-HT(1A), 5-HT(2A), and 5-HT(4) receptors and the serotonin reuptake transporter have been explored for their sensitivity to 5-HT fluctuations, but with mixed outcomes; tracers for these targets cannot reliably image endogenous 5-HT in humans. Shortcomings in our basic knowledge of the mechanisms underlying changes in binding potential are addressed, and suggestions are made as to how the selection of targets, radiotracers, challenge paradigms, and experimental design might be optimised to improve our chances of successfully imaging endogenous neurotransmitters in the future.
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Mengod G, Cortés R, Vilaró MT, Hoyer D. Distribution of 5-HT Receptors in the Central Nervous System. Handbook of Behavioral Neuroscience 2010. [DOI: 10.1016/s1569-7339(10)70074-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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Affiliation(s)
- Simon M Ametamey
- Center for Radiopharmaceutical Science of ETH, PSI and USZ, Department of Chemistry and Applied Biosciences of ETH, CH-8093 Zurich, Switzerland.
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Dollé F. [18F]fluoropyridines: From conventional radiotracers to the labeling of macromolecules such as proteins and oligonucleotides. Ernst Schering Res Found Workshop 2007:113-57. [PMID: 17172154 DOI: 10.1007/978-3-540-49527-7_5] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/13/2023]
Abstract
Molecular in vivo imaging with the high-resolution and sensitive positron emission tomography (PET) technique requires the preparation of a positron-emitting radiolabeled probe or radiotracer. For this purpose, fluorine-18 is becoming increasingly the radionuclide of choice due to its adequate physical and nuclear characteristics, and also because of the successful use in clinical oncology of 2-[18F]fluoro-2-deoxy-D-glucose ([18F]FDG), which is currently the most widely used PET-radiopharmaceutical and probably the driving force behind the growing availability and interest for this positron-emitter in radiopharmaceutical chemistry. With a few exceptions, radiofluorinations involving fluorine-18 of high specific radioactivity (e.g. > 185 GBq/micromole) had, until recently, been limited to nucleophilic substitutions in homoaromatic and aliphatic series with [18F]fluoride. Considering chemical structures showing a fluoropyridinyl moiety, nucleophilic heteroaromatic substitution at the ortho-position with no-carrier-added [l8F]fluoride, as its K[18F]F-K222 complex, appears today as a highly efficient method for the radiosynthesis of radiotracers and radiopharmaceuticals. This chapter summarizes the recent applications of this methodology and highlights its potential in the design and preparation of, often drug-based, fluorine-18-labeled probes of high specific radioactivity for PET imaging, including macromolecules of biological interest such as peptides, proteins and oligonucleotides.
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Affiliation(s)
- F Dollé
- Service Hospitalier Frédéric Joliot, Département de Recherche Médicale - CEA, Orsay, France.
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Lavén M, Itsenko O, Markides K, Långström B. Determination of metabolic stability of positron emission tomography tracers by LC–MS/MS: An example in WAY-100635 and two analogues. J Pharm Biomed Anal 2006; 40:943-51. [PMID: 16388927 DOI: 10.1016/j.jpba.2005.08.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2004] [Revised: 08/05/2005] [Accepted: 08/06/2005] [Indexed: 10/25/2022]
Abstract
A method is presented for determination of microsomal metabolic stability of potential positron emission tomography (PET) tracers by LC-MS/MS in the lower nm range. The PET tracers used for the study were the serotonin receptor antagonist WAY-100635 and two potential tracer analogues. The sensitivity permitted the substrates to be directly collected from PET radiolabelling batches, containing very low amounts of substance (0.3-7 microg), for subsequent metabolic stability incubations. Sample preparation was minimal, with addition of internal standard, acetonitrile and a fast centrifugation step, as a result of the low protein concentration of the microsome solutions. Linearity (R2 > or = 0.99), precision (inter-assay R.S.D. < 7%) and accuracy (bias < or = 8%) for the tested concentration range 0.5-5 nM proved to be well within accepted limits. No significant differences in metabolic rates were detected using substrates from cold (non-labelling) chemistry syntheses and PET labelling batches, indicating the validity of using substrates from the latter source. A para-methoxy-benzamide analogue (MeO-WAY) displayed a significantly lower rate of metabolism compared to WAY-100635, whereas a para-iodo-benzamide analogue was more susceptible to metabolic transformation. LC-MS/MS Analysis of formed metabolites from WAY-100635 and MeO-WAY suggested similar metabolic pathways, with hydroxylation, demethylation and dearylation reactions. The main metabolic route in humans, amide hydrolysis, was not observed with the rat liver microsome assay.
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Affiliation(s)
- M Lavén
- Department of Analytical Chemistry, Institute of Chemistry, Uppsala University, Box 599, 751 24 Uppsala, Sweden
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15
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McCarron JA, Marchais-Oberwinkler S, Pike VW, Tarkiainen J, Halldin C, Sóvagó J, Gulyas B, Wikström HV, Farde L. Two C-Methyl Derivatives of [11C]WAY-100635 – Effects of an Amido α-Methyl Group on Metabolism and Brain 5-HT1A Receptor Radioligand Behavior in Monkey*. Mol Imaging Biol 2005; 7:209-19. [PMID: 15912425 DOI: 10.1007/s11307-005-4127-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
PURPOSE [carbonyl-11C]N-(2-(1-(4-(2-methoxyphenyl)-piperazinyl)ethyl)-N-pyridinyl)cyclohexanecarboxamide ([carbonyl-11C]WAY-100635) is an effective radioligand for imaging brain 5-HT1A receptors with positron emission tomography (PET). However, this radioligand has some drawbacks for deriving relative regional receptor densities, including rapid metabolism, which acts against accurate definition of an arterial input function for compartmental modeling, and very low nonspecific binding in brain, which detracts from the accuracy of modeling by a simplified reference tissue (cerebellum) approach. Here, in a search for a radioligand that overcomes these limitations, we investigated the effects of introducing a single methyl group at either of the carbon atoms alpha to the amide bond in [11C]WAY-100635. PROCEDURES Ligands with a methyl group on the alpha carbon of the cyclohexyl group (SWAY) or the alpha carbon of the C2H4 linker ((R,S)-JWAY) were synthesized and tested for binding affinity and intrinsic activity at 5-HT1A receptors. SWAY was labeled with carbon-11 (t1/2 = 20.4 minutes; beta+ = 99.8%) in its O-methyl group and (R,S)-JWAY in its carbonyl group. Each radioligand was evaluated by PET experiments in cynomolgus monkey. RESULTS SWAY and (R,S)-JWAY were found to be high-affinity antagonists at 5-HT1A receptors. After injection of [11C]SWAY into monkey, radioactivity uptake in brain reached a maximum of 3% at 4.5 minutes and decreased to 0.7% at 72 minutes. However, over the time span of the experiment, radioactivity concentrations in 5-HT1A receptor-rich brain regions were only fractionally higher than in cerebellum. Radioactivity represented by parent radioligand in plasma was 39% at 45 minutes. After injection of [11C](R,S)-JWAY alone, radioactivity uptake in brain reached a maximum of 4.8% at 2.5 minutes and decreased to 1.2% at 90 minutes. At this time, radioactivity concentration in 5-HT1A receptor-rich brain regions was markedly greater than in cerebellum. In another PET experiment, the monkey was predosed with WAY-100635 before [11C](R,S)-JWAY injection. At 90 minutes after injection, the ratio of radioactivity in 5-HT1A receptor-rich regions to that in cerebellum was reduced to near unity. Radioactivity represented by parent radioligand in plasma was 12% at 45 minutes. CONCLUSIONS [11C](R,S)-JWAY, but not [11C]SWAY, gives a sizeable 5-HT1A receptor-selective PET signal in monkey. The presence of a C-methyl group adjacent to the amide bond in SWAY or (R,S)-JWAY fails to counter metabolism.
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Affiliation(s)
- Julie A McCarron
- MRC Cyclotron Unit, Imperial College School of Medicine, Hammersmith Hospital, Ducane Road, London, W12 0NN, UK.
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Marchais-Oberwinkler S, Nowicki B, Pike VW, Halldin C, Sandell J, Chou YH, Gulyas B, Brennum LT, Farde L, Wikström HV. N-Oxide analogs of WAY-100635: new high affinity 5-HT1A receptor antagonists. Bioorg Med Chem 2005; 13:883-93. [PMID: 15653354 DOI: 10.1016/j.bmc.2004.10.033] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2003] [Accepted: 10/13/2004] [Indexed: 11/30/2022]
Abstract
WAY-100635 [N-(2-(1-(4-(2-methoxyphenyl)piperazinyl)ethyl))-N-(2-pyridinyl)cyclohexanecarboxamide] 1 and its O-desmethyl derivative DWAY 2 are well-known high affinity 5-HT(1A) receptor antagonists, which when labeled with carbon-11 (beta+; t(1/2) = 20.4 min) in the carbonyl group are effective radioligands for imaging brain 5-HT(1A) receptors with positron emission tomography (PET). In a search for new 5-HT(1A) antagonists with different pharmacokinetic and metabolic properties, the pyridinyl N-oxide moiety was incorporated into analogs of 1 and 2. NOWAY 3, in which the pyridinyl ring of 1 was oxidized to the pyridinyl N-oxide, was prepared via nucleophilic substitution of 2-[4-(2-methoxyphenyl)piperazin-1-yl]ethylamine on 2-chloropyridine-N-oxide followed by acylation with cyclohexanecarbonyl chloride. 6Cl-NOWAY 4, a more lipophilic (pyridinyl-6)-chloro derivative of 3, was prepared by treating 1-(2-methoxyphenyl)-4-(2-(2-(6-bromo)aminopyridinyl-N-oxide)ethyl)piperazine with cyclohexanecarbonyl chloride for acylation and concomitant chloro for bromo substitution. NEWWAY 5, in which the 2-hydroxy-phenyl group of 2 is replaced with a 2-pyridinyl N-oxide group with the intention of mimicking the topology of 2, was prepared in five steps from 2-(chloroacetylamino)pyridine. N-Oxides 3-5 were found to be high affinity antagonists at 5-HT(1A) receptors, with 3 having the highest affinity and a Ki value (0.22 nM) comparable to that of 1 (0.17 nM). By calculation the lipophilicity of 3 (LogP = 1.87) is lower than that of 1 by 1.25 LogP units while TLC and reverse phase HPLC indicate that 3 has slightly lower lipophilicity than 1. On the basis of these encouraging findings, the N-oxide 3 was selected for labeling with carbon-11 in its carbonyl group and for evaluation as a radioligand with PET. After intravenous injection of [carbonyl-11C]3 into cynomolgus monkey there was very low uptake of radioactivity into brain and no PET image of brain 5-HT(1A) receptors was obtained. Either 3 inadequately penetrates the blood-brain barrier or it is excluded from brain by an active efflux mechanism. Rapid deacylation of 3 was not apparent in vivo; in cynomolgus monkey plasma radioactive metabolites of [carbonyl-11C]3 appeared less rapidly than from the radioligands [carbonyl-11C]1 and [carbonyl-11C]2, which are known to be primarily metabolized by deacylation. Ligand 3 may have value as a new pharmacological tool, but not as a radioligand for brain imaging.
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Affiliation(s)
- Sandrine Marchais-Oberwinkler
- Department of Medicinal Chemistry, University Center for Pharmacy, University of Groningen, Antonius Deusinglaan 1, NL-9713 AV Groningen, The Netherlands.
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Karramkam M, Hinnen F, Berrehouma M, Hlavacek C, Vaufrey F, Halldin C, McCarron JA, Pike VW, Dollé F. Synthesis of a [6-pyridinyl-18F]-labelled fluoro derivative of WAY-100635 as a candidate radioligand for brain 5-HT1A receptor imaging with PET. Bioorg Med Chem 2003; 11:2769-82. [PMID: 12788351 DOI: 10.1016/s0968-0896(03)00225-6] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
In recent years, considerable effort has been spent on the design, synthesis and pharmacological characterization of radiofluorinated derivatives of the 5-HT(1A) receptor antagonist, WAY-100635, for the in vivo study of these receptors in human brain with PET. (Pyridinyl-6)-fluoro- and (pyridinyl-5)-fluoro-analogues of WAY-100635 (6-fluoro and 5-fluoro-WAY-100635, 5a/6a) were synthesized as well as the corresponding chloro-, bromo- and nitro-derivatives as precursors for labelling (5b-d and 6b-d). Comparative radiolabelling of these precursors with fluorine-18 (positron-emitting isotope, 109.8 min half-life) clearly demonstrated that only ortho-fluorination in this pyridine series, and not meta-fluorination, is of interest for the preparation of a radioligand by nucleophilic heteroaromatic substitution. 6-[(18)F]Fluoro-WAY-100635 ([(18)F]5a) can be efficiently synthesized in one step, either from the corresponding 6-bromo precursor (using conventional heating at 145 degrees C for 10 min) or from the corresponding 6-nitro precursor (using microwave activation at 100 W for 1 min). Typically, 15-25 mCi (0.55-0.92 GBq) of 6-[(18)F]fluoro-WAY-100635 ([(18)F]5a, 1-2 Ci/micromol or 37-72 GBq/micromol) were obtained in 50-70 min starting from a 100 mCi (3.7 GBq) aliquot of a batch of cyclotron-produced [(18)F]fluoride. This (18)F-labelled radioligand is now being evaluated in PET studies.
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Affiliation(s)
- Mylène Karramkam
- Service Hospitalier Frédéric Joliot, Département de Recherche Médicale, CEA, 4 place du Général Leclerc, F-91401 Orsay, France
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Drews A, Pietzsch HJ, Syhre R, Seifert S, Varnäs K, Hall H, Halldin C, Kraus W, Karlsson P, Johnsson C, Spies H, Johannsen B. Synthesis and biological evaluation of technetium(III) mixed-ligand complexes with high affinity for the cerebral 5-HT(1A) receptor and the alpha1-adrenergic receptor. Nucl Med Biol 2002; 29:389-98. [PMID: 12031873 DOI: 10.1016/s0969-8051(02)00296-2] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Tc(III) and Re(III) complexes [M(NS(3))(CNR)] (M = Re, 99mTc, NS(3) = 2,2',2"-nitrilotris(ethanethiol), CNR = functionalized isocyanide bearing a derivative of WAY 100635) have been synthesized and characterized. Re was used as Tc surrogate for chemical characterization and in vitro receptor-binding studies. For two representatives subnanomolar affinities for the 5-HT(1A) as well as for the alpha1-adrenergic receptor were reached. Biodistribution studies in rats of the 99mTc complexes showed brain uptakes between 0.3 and 0.5% ID/organ (5 min p.i.). In vitro autoradiography of one 99mTc representative in sections of post mortem human brain indicate its accumulation in 5-HT(1A) receptor-rich brain regions. However, addition of the specific 5-HT(1A) receptor agonist 8-OH-DPAT as well as the alpha1-adrenoceptor antagonist prazosin could not substantially block this tracer accumulation. A preliminary SPET study in a monkey showed negligible brain uptake.
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Affiliation(s)
- A Drews
- Forschungszentrum Rossendorf, Institut für Bioanorganische und Radiopharmazeutische Chemie, Dresden, Germany
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Sandell J, Halldin C, Chou YH, Swahn CG, Thorberg SO, Farde L. PET-examination and metabolite evaluation in monkey of [(11)C]NAD-299, a radioligand for visualisation of the 5-HT(1A) receptor. Nucl Med Biol 2002; 29:39-45. [PMID: 11786274 DOI: 10.1016/s0969-8051(01)00272-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
NAD-299 is a selective 5-HT(1A) receptor antagonist that is currently developed as a putative antidepressant drug. [(11)C]NAD-299 was examined in the cynomolgus monkey brain with positron emission tomography (PET). After radioligand injection high accumulation of radioactivity was observed in the frontal and temporal cortex and the raphe nuclei, regions known to contain a high density of 5-HT(1A) receptors. Peak equilibrium appeared already at about 10 min after i.v. injection. Pre-treatment with a high dose of the antagonist WAY-100635 reduced the amount of radioactivity in the cortex and the raphe to the level of the cerebellum. A strong pre-treatment effect could also be achieved using pindolol, a partial agonist at the 5-HT(1A)-receptors. The appearance of labeled metabolites in monkey plasma was measured with HPLC. At 45 minutes after injection 49% (range 27-55%, n = 5) of radioactivity in monkey plasma represented unchanged radioligand. [(11)C]NAD-299 was metabolized to more polar labeled metabolites of which one has the same chromatographic mobility as the descyclobutyl analogue of NAD-299 (NAD-272). The results indicate that [(11)C]NAD-299 has potential as a PET radioligand for studies of 5-HT(1A) receptors in the primate brain.
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Affiliation(s)
- Johan Sandell
- Karolinska Institutet, Department of Clinical Neuroscience, Psychiatry Section, Karolinska Hospital, S-171 76 Stockholm, Sweden.
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