1
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Li Y, Dahl K, Johnström P, Varnäs K, Farde L, Halldin C, Medd A, Maier D, Powell ME, Chen J, Van R, Patel J, Chaudhary A, Gao Y, Song Z, Haider A, Shao Y, Elmore CS, Liang S, Schou M. Radiosynthesis and Evaluation of 11C-Labeled Isoindolone-Based Positive Allosteric Modulators for Positron Emission Tomography Imaging of Metabotropic Glutamate Receptor 2. ACS Pharmacol Transl Sci 2024; 7:2414-2423. [PMID: 39144551 PMCID: PMC11320742 DOI: 10.1021/acsptsci.4c00261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2024] [Revised: 06/23/2024] [Accepted: 06/26/2024] [Indexed: 08/16/2024]
Abstract
The metabotropic glutamate receptor 2 (mGluR2) has emerged as a potential therapeutic target for the treatment of various neurological diseases, prompting substantial interest in the development of mGluR2-targeted drug candidates. As part of our medicinal chemistry program, we synthesized a series of isoindolone derivatives and assessed their potential as mGluR2 positive allosteric modulators (PAMs). Notably, AZ12559322 exhibited high affinity (K i mGluR2 = 1.31 nM) and an excellent in vitro binding specificity of 89% while demonstrating selectivity over other mGluR subtypes (>4000-fold). Autoradiography with the radiolabeled counterpart, [3H]AZ12559322, revealed a heterogeneous accumulation with the highest binding in mGluR2-rich brain regions. Radioligand binding was significantly reduced by pretreatment with nonradioactive mGluR2 PAMs in brains of rats and nonhuman primates. Although positron emission tomography imaging of [11C]AZ12559322 (6a) revealed low brain uptake in a nonhuman primate, this study provides valuable guidance to further design novel isoindolone-based mGluR2 PAMs with improved brain exposure.
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Affiliation(s)
- Yinlong Li
- Department
of Radiology and Imaging Sciences, Emory
University, 1364 Clifton
Road, Atlanta, Georgia 30322, United States
| | - Kenneth Dahl
- PET
Science Centre, Precision Medicine and Biosamples, Oncology R&D,
AstraZeneca, Karolinska Institutet, Stockholm S-17176, Sweden
- Department
of Clinical Neuroscience, Centre for Psychiatry Research, Karolinska Institutet and Stockholm County Council, Stockholm S-17176, Sweden
| | - Peter Johnström
- PET
Science Centre, Precision Medicine and Biosamples, Oncology R&D,
AstraZeneca, Karolinska Institutet, Stockholm S-17176, Sweden
- Department
of Clinical Neuroscience, Centre for Psychiatry Research, Karolinska Institutet and Stockholm County Council, Stockholm S-17176, Sweden
| | - Katarina Varnäs
- Department
of Clinical Neuroscience, Centre for Psychiatry Research, Karolinska Institutet and Stockholm County Council, Stockholm S-17176, Sweden
| | - Lars Farde
- Department
of Clinical Neuroscience, Centre for Psychiatry Research, Karolinska Institutet and Stockholm County Council, Stockholm S-17176, Sweden
| | - Christer Halldin
- Department
of Clinical Neuroscience, Centre for Psychiatry Research, Karolinska Institutet and Stockholm County Council, Stockholm S-17176, Sweden
| | - Amy Medd
- Neuroscience,
BioPharmaceuticals R&D, AstraZeneca, Wilmington, Delaware 19803, United States
| | - Donna Maier
- Neuroscience,
BioPharmaceuticals R&D, AstraZeneca, Wilmington, Delaware 19803, United States
| | - Mark E. Powell
- Neuroscience,
BioPharmaceuticals R&D, AstraZeneca, Wilmington, Delaware 19803, United States
| | - Jiahui Chen
- Department
of Radiology and Imaging Sciences, Emory
University, 1364 Clifton
Road, Atlanta, Georgia 30322, United States
| | - Richard Van
- Department
of Chemistry and Biochemistry, University
of Oklahoma, Norman, Oklahoma 73019-5251, United States
| | - Jimmy Patel
- Department
of Radiology and Imaging Sciences, Emory
University, 1364 Clifton
Road, Atlanta, Georgia 30322, United States
| | - Ahmad Chaudhary
- Department
of Radiology and Imaging Sciences, Emory
University, 1364 Clifton
Road, Atlanta, Georgia 30322, United States
| | - Yabiao Gao
- Department
of Radiology and Imaging Sciences, Emory
University, 1364 Clifton
Road, Atlanta, Georgia 30322, United States
| | - Zhendong Song
- Department
of Radiology and Imaging Sciences, Emory
University, 1364 Clifton
Road, Atlanta, Georgia 30322, United States
| | - Ahmed Haider
- Department
of Radiology and Imaging Sciences, Emory
University, 1364 Clifton
Road, Atlanta, Georgia 30322, United States
| | - Yihan Shao
- Department
of Chemistry and Biochemistry, University
of Oklahoma, Norman, Oklahoma 73019-5251, United States
| | - Charles S. Elmore
- Neuroscience,
BioPharmaceuticals R&D, AstraZeneca, Wilmington, Delaware 19803, United States
- Early
Chemical Development, Pharmaceutical Sciences, R&D, AstraZeneca Pharmaceuticals, Gothenburg 43183, Sweden
| | - Steven Liang
- Department
of Radiology and Imaging Sciences, Emory
University, 1364 Clifton
Road, Atlanta, Georgia 30322, United States
| | - Magnus Schou
- PET
Science Centre, Precision Medicine and Biosamples, Oncology R&D,
AstraZeneca, Karolinska Institutet, Stockholm S-17176, Sweden
- Department
of Clinical Neuroscience, Centre for Psychiatry Research, Karolinska Institutet and Stockholm County Council, Stockholm S-17176, Sweden
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2
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Cools R, Kerkhofs K, Leitao RCF, Bormans G. Preclinical Evaluation of Novel PET Probes for Dementia. Semin Nucl Med 2023; 53:599-629. [PMID: 37149435 DOI: 10.1053/j.semnuclmed.2023.03.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Accepted: 03/24/2023] [Indexed: 05/08/2023]
Abstract
The development of novel PET imaging agents that selectively bind specific dementia-related targets can contribute significantly to accurate, differential and early diagnosis of dementia causing diseases and support the development of therapeutic agents. Consequently, in recent years there has been a growing body of literature describing the development and evaluation of potential new promising PET tracers for dementia. This review article provides a comprehensive overview of novel dementia PET probes under development, classified by their target, and pinpoints their preclinical evaluation pathway, typically involving in silico, in vitro and ex/in vivo evaluation. Specific target-associated challenges and pitfalls, requiring extensive and well-designed preclinical experimental evaluation assays to enable successful clinical translation and avoid shortcomings observed for previously developed 'well-established' dementia PET tracers are highlighted in this review.
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Affiliation(s)
- Romy Cools
- Laboratory for Radiopharmaceutical Research, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium
| | - Kobe Kerkhofs
- Laboratory for Radiopharmaceutical Research, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium; NURA, Belgian Nuclear Research Centre (SCK CEN), Mol, Belgium
| | - Renan C F Leitao
- Laboratory for Radiopharmaceutical Research, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium
| | - Guy Bormans
- Laboratory for Radiopharmaceutical Research, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium.
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3
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Yuan G, Dhaynaut M, Guehl NJ, Neelamegam R, Moon SH, Qu X, Poutiainen P, Afshar S, Fakhri GE, Normandin MD, Brownell AL. PET imaging studies to investigate functional expression of mGluR2 using [ 11C]mG2P001. J Cereb Blood Flow Metab 2023; 43:296-308. [PMID: 36172629 PMCID: PMC9903221 DOI: 10.1177/0271678x221130387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Revised: 08/11/2022] [Accepted: 08/15/2022] [Indexed: 01/24/2023]
Abstract
Metabotropic glutamate receptor 2 (mGluR2) has been extensively studied for the treatment of various neurological and psychiatric disorders. Understanding of the mGluR2 function is pivotal in supporting the drug discovery targeting mGluR2. Herein, the positive allosteric modulation of mGluR2 was investigated via the in vivo positron emission tomography (PET) imaging using 2-((4-(2-[11C]methoxy-4-(trifluoromethyl)phenyl)piperidin-1-yl)methyl)-1-methyl-1H-imidazo[4,5-b]pyridine ([11C]mG2P001). Distinct from the orthosteric compounds, pretreatment with the unlabeled mG2P001, a potent mGluR2 positive allosteric modulator (PAM), resulted in a significant increase instead of decrease of the [11C]mG2P001 accumulation in rat brain detected by PET imaging. Subsequent in vitro studies with [3H]mG2P001 revealed the cooperative binding mechanism of mG2P001 with glutamate and its pharmacological effect that contributed to the enhanced binding of [3H]mG2P001 in transfected CHO cells expressing mGluR2. The in vivo PET imaging and quantitative analysis of [11C]mG2P001 in non-human primates (NHPs) further validated the characteristics of [11C]mG2P001 as an imaging ligand for mGluR2. Self-blocking studies in primates enhanced accumulation of [11C]mG2P001. Altogether, these studies show that [11C]mG2P001 is a sensitive biomarker for mGluR2 expression and the binding is affected by the tissue glutamate concentration.
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Affiliation(s)
- Gengyang Yuan
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 125 Nashua Street, Suite 660, Boston, MA 02114, USA
| | - Maeva Dhaynaut
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 125 Nashua Street, Suite 660, Boston, MA 02114, USA
| | - Nicolas J Guehl
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 125 Nashua Street, Suite 660, Boston, MA 02114, USA
| | - Ramesh Neelamegam
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 125 Nashua Street, Suite 660, Boston, MA 02114, USA
| | - Sung-Hyun Moon
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 125 Nashua Street, Suite 660, Boston, MA 02114, USA
| | - Xiying Qu
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 125 Nashua Street, Suite 660, Boston, MA 02114, USA
| | - Pekka Poutiainen
- Department of Clinical Physiology and Nuclear Medicine, Kuopio University Hospital, Kuopio, 70210, Finland
| | - Sepideh Afshar
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 125 Nashua Street, Suite 660, Boston, MA 02114, USA
| | - Georges El Fakhri
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 125 Nashua Street, Suite 660, Boston, MA 02114, USA
| | - Marc D Normandin
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 125 Nashua Street, Suite 660, Boston, MA 02114, USA
| | - Anna-Liisa Brownell
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 125 Nashua Street, Suite 660, Boston, MA 02114, USA
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4
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Yuan G, Dhaynaut M, Guehl NJ, Afshar S, Huynh D, Moon SH, Iyengar SM, Jain MK, Pickett JE, Kang HJ, Ondrechen MJ, El Fakhri G, Normandin MD, Brownell AL. Design, Synthesis, and Characterization of [ 18F]mG2P026 as a High-Contrast PET Imaging Ligand for Metabotropic Glutamate Receptor 2. J Med Chem 2022; 65:9939-9954. [PMID: 35802702 PMCID: PMC9434700 DOI: 10.1021/acs.jmedchem.2c00593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
An array of triazolopyridines based on JNJ-46356479 (6) were synthesized as potential positron emission tomography radiotracers for metabotropic glutamate receptor 2 (mGluR2). The selected candidates 8-10 featured enhanced positive allosteric modulator (PAM) activity (20-fold max.) and mGluR2 agonist activity (25-fold max.) compared to compound 6 in the cAMP GloSensor assays. Radiolabeling of compounds 8 and 9 (mG2P026) was achieved via Cu-mediated radiofluorination with satisfactory radiochemical yield, >5% (non-decay-corrected); high molar activity, >180 GBq/μmol; and excellent radiochemical purity, >98%. Preliminary characterization of [18F]8 and [18F]9 in rats confirmed their excellent brain permeability and binding kinetics. Further evaluation of [18F]9 in a non-human primate confirmed its superior brain heterogeneity in mapping mGluR2 and higher affinity than [18F]6. Pretreatment with different classes of PAMs in rats and a primate led to similarly enhanced brain uptake of [18F]9. As a selective ligand, [18F]9 has the potential to be developed for translational studies.
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Affiliation(s)
- Gengyang Yuan
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 3rd Avenue, Charlestown, Massachusetts 02129, United States
| | - Maeva Dhaynaut
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 3rd Avenue, Charlestown, Massachusetts 02129, United States
| | - Nicolas J Guehl
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 3rd Avenue, Charlestown, Massachusetts 02129, United States
| | - Sepideh Afshar
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 3rd Avenue, Charlestown, Massachusetts 02129, United States
| | - Dalena Huynh
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 3rd Avenue, Charlestown, Massachusetts 02129, United States
| | - Sung-Hyun Moon
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 3rd Avenue, Charlestown, Massachusetts 02129, United States
| | - Suhasini M Iyengar
- Department of Chemistry and Chemical Biology, Northeastern University, 360 Huntington Avenue, Boston, Massachusetts 02115, United States
| | - Manish Kumar Jain
- Department of Pharmacology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, North Carolina 27599, United States
| | - Julie E Pickett
- Department of Pharmacology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, North Carolina 27599, United States
| | - Hye Jin Kang
- Department of Pharmacology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, North Carolina 27599, United States
| | - Mary Jo Ondrechen
- Department of Chemistry and Chemical Biology, Northeastern University, 360 Huntington Avenue, Boston, Massachusetts 02115, United States
| | - Georges El Fakhri
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 3rd Avenue, Charlestown, Massachusetts 02129, United States
| | - Marc D Normandin
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 3rd Avenue, Charlestown, Massachusetts 02129, United States
| | - Anna-Liisa Brownell
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 3rd Avenue, Charlestown, Massachusetts 02129, United States
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5
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Yuan G, Dhaynaut M, Lan Y, Guehl NJ, Huynh D, Iyengar SM, Afshar S, Jain MK, Pickett JE, Kang HJ, Wang H, Moon SH, Ondrechen MJ, Wang C, Shoup TM, El Fakhri G, Normandin MD, Brownell AL. Synthesis and Characterization of 5-(2-Fluoro-4-[ 11C]methoxyphenyl)-2,2-dimethyl-3,4-dihydro-2 H-pyrano[2,3- b]pyridine-7-carboxamide as a PET Imaging Ligand for Metabotropic Glutamate Receptor 2. J Med Chem 2022; 65:2593-2609. [PMID: 35089713 PMCID: PMC9434702 DOI: 10.1021/acs.jmedchem.1c02004] [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] [Indexed: 11/30/2022]
Abstract
Metabotropic glutamate receptor 2 (mGluR2) is a therapeutic target for several neuropsychiatric disorders. An mGluR2 function in etiology could be unveiled by positron emission tomography (PET). In this regard, 5-(2-fluoro-4-[11C]methoxyphenyl)-2,2-dimethyl-3,4-dihydro-2H-pyrano[2,3-b]pyridine-7-carboxamide ([11C]13, [11C]mG2N001), a potent negative allosteric modulator (NAM), was developed to support this endeavor. [11C]13 was synthesized via the O-[11C]methylation of phenol 24 with a high molar activity of 212 ± 76 GBq/μmol (n = 5) and excellent radiochemical purity (>99%). PET imaging of [11C]13 in rats demonstrated its superior brain heterogeneity and reduced accumulation with pretreatment of mGluR2 NAMs, VU6001966 (9) and MNI-137 (26), the extent of which revealed a time-dependent drug effect of the blocking agents. In a nonhuman primate, [11C]13 selectively accumulated in mGluR2-rich regions and resulted in high-contrast brain images. Therefore, [11C]13 is a potential candidate for translational PET imaging of the mGluR2 function.
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Affiliation(s)
- Gengyang Yuan
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 3rd Avenue, Charlestown, Massachusetts 02129, United States
| | - Maeva Dhaynaut
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 3rd Avenue, Charlestown, Massachusetts 02129, United States
| | - Yu Lan
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts 02129, United States
| | - Nicolas J Guehl
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 3rd Avenue, Charlestown, Massachusetts 02129, United States
| | - Dalena Huynh
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 3rd Avenue, Charlestown, Massachusetts 02129, United States
| | - Suhasini M Iyengar
- Department of Chemistry and Chemical Biology, Northeastern University, 360 Huntington Avenue, Boston, Massachusetts 02115, United States
| | - Sepideh Afshar
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 3rd Avenue, Charlestown, Massachusetts 02129, United States
| | - Manish Kumar Jain
- Department of Pharmacology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, North Carolina 27599, United States
| | - Julie E Pickett
- Department of Pharmacology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, North Carolina 27599, United States
| | - Hye Jin Kang
- Department of Pharmacology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, North Carolina 27599, United States
| | - Hao Wang
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts 02129, United States
| | - Sung-Hyun Moon
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 3rd Avenue, Charlestown, Massachusetts 02129, United States
| | - Mary Jo Ondrechen
- Department of Chemistry and Chemical Biology, Northeastern University, 360 Huntington Avenue, Boston, Massachusetts 02115, United States
| | - Changning Wang
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts 02129, United States
| | - Timothy M Shoup
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 3rd Avenue, Charlestown, Massachusetts 02129, United States
| | - Georges El Fakhri
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 3rd Avenue, Charlestown, Massachusetts 02129, United States
| | - Marc D Normandin
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 3rd Avenue, Charlestown, Massachusetts 02129, United States
| | - Anna-Liisa Brownell
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 3rd Avenue, Charlestown, Massachusetts 02129, United States
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Guo J, Yang W, Zhang D, Wang SG, Wang X. Mechanistic Insights into Formation of All-Carbon Quaternary Centers via Scandium-Catalyzed C-H Alkylation of Imidazoles with 1,1-Disubstituted Alkenes. J Org Chem 2021; 86:4598-4606. [PMID: 33686862 DOI: 10.1021/acs.joc.0c03054] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
This density functional theory (DFT) study reveals a detailed plausible mechanism for the Sc-catalyzed C-H cycloaddition of imidazoles to 1,1-disubstituted alkenes to form all-carbon quaternary stereocenters. The Sc complex binds the imidazole substrate to enable deprotonative C2-H bond activation by the Sc-bound α-carbon to afford the active species. This complex undergoes intramolecular cyclization (C═C into Sc-imidazolyl insertion) with exo-selectivity, generating a β-all-carbon-substituted quaternary center in the polycyclic imidazole derivative. The Sc-bound α-carbon deprotonates the imidazole C2-H bond to deliver the product and regenerate the active catalyst, which is the rate-determining step. Calculations illuminate the electronic effect of the ancillary Cp ligand on the catalyst activity and reveal the steric bias caused by using a chiral catalyst that induce the enantioselectivity. The insights can have implications for advancing rare-earth metal-catalyzed C-H functionalization of imidazoles.
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Affiliation(s)
- Jiandong Guo
- Hoffmann Institute of Advanced Materials, Postdoctoral Innovation Practice Base, Shenzhen Polytechnic, 7098 Liuxian Boulevard, Nanshan District, Shenzhen 518055, P. R. China.,Institute of Theoretical Chemistry, School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, P. R. China
| | - Wu Yang
- Hoffmann Institute of Advanced Materials, Postdoctoral Innovation Practice Base, Shenzhen Polytechnic, 7098 Liuxian Boulevard, Nanshan District, Shenzhen 518055, P. R. China.,Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, P. R. China
| | - Dongju Zhang
- Institute of Theoretical Chemistry, School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, P. R. China
| | - Shou-Guo Wang
- Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, P. R. China
| | - Xiaotai Wang
- Hoffmann Institute of Advanced Materials, Postdoctoral Innovation Practice Base, Shenzhen Polytechnic, 7098 Liuxian Boulevard, Nanshan District, Shenzhen 518055, P. R. China.,Department of Chemistry, University of Colorado Denver, Campus Box 194, P. O. Box 1733, Denver, Colorado 80217-3364, United States
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7
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Yuan G, Guehl NJ, Zheng B, Qu X, Moon SH, Dhaynaut M, Shoup TM, Afshar S, Kang HJ, Zhang Z, El Fakhri G, Normandin MD, Brownell AL. Synthesis and Characterization of [ 18F]JNJ-46356479 as the First 18F-Labeled PET Imaging Ligand for Metabotropic Glutamate Receptor 2. Mol Imaging Biol 2021; 23:527-536. [PMID: 33559035 DOI: 10.1007/s11307-021-01586-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Revised: 01/11/2021] [Accepted: 01/27/2021] [Indexed: 02/07/2023]
Abstract
PURPOSE Metabotropic glutamate receptor 2 (mGluR2) has been implicated in various psychiatric and neurological disorders, such as schizophrenia and Alzheimer's disease. We have previously developed [11C]7 as a PET radioligand for imaging mGluR2. Herein, [18F]JNJ-46356479 ([18F]8) was synthesized and characterized as the first 18F-labeled mGluR2 imaging ligand to enhance diagnostic approaches for mGluR2-related disorders. PROCEDURES JNJ-46356479 (8) was radiolabeled via the copper (I)-mediated radiofluorination of organoborane 9. In vivo PET imaging experiments with [18F]8 were conducted first in C57BL/6 J mice and Sprague-Dawley rats to obtain whole body biodistribution and brain uptake profile. Subsequent PET studies were done in a cynomolgus monkey (Macaca fascicularis) to investigate the uptake of [18F]8 in the brain, its metabolic stability, as well as pharmacokinetic properties. RESULTS JNJ-46356479 (8) exhibited excellent selectivity against other mGluRs. In vivo PET imaging studies showed reversible and specific binding characteristic of [18F]8 in rodents. In the non-human primate, [18F]8 displayed good in vivo metabolic stability, excellent brain permeability, fast and reversible kinetics with moderate heterogeneity across brain regions. Pre-treatment studies with compound 7 revealed time-dependent decrease of [18F]8 accumulation in mGluR2 rich regions based on SUV values with the highest decrease in the nucleus accumbens (18.7 ± 5.9%) followed by the cerebellum (18.0 ± 7.9%), the parietal cortex (16.9 ± 7.8%), and the hippocampus (16.8 ± 6.9%), similar to results obtained in the rat studies. However, the volume of distribution (VT) results derived from 2T4k model showed enhanced VT from a blocking study with compound 7. This is probably because of the potentiating effect of compound 7 as an mGluR2 PAM as well as related non-specific binding in the tissue data. CONCLUSIONS [18F]8 readily crosses the blood-brain barrier and demonstrates fast and reversible kinetics both in rodents and in a non-human primate. Further investigation of [18F]8 on its binding specificity would warrant translational study in human.
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Affiliation(s)
- Gengyang Yuan
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 3rd Avenue, Charlestown, MA, 02129, USA.
| | - Nicolas J Guehl
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 3rd Avenue, Charlestown, MA, 02129, USA
| | - Baohui Zheng
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 3rd Avenue, Charlestown, MA, 02129, USA
| | - Xiying Qu
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 3rd Avenue, Charlestown, MA, 02129, USA
| | - Sung-Hyun Moon
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 3rd Avenue, Charlestown, MA, 02129, USA
| | - Maeva Dhaynaut
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 3rd Avenue, Charlestown, MA, 02129, USA
| | - Timothy M Shoup
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 3rd Avenue, Charlestown, MA, 02129, USA
| | - Sepideh Afshar
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 3rd Avenue, Charlestown, MA, 02129, USA
| | - Hye Jin Kang
- Department of Pharmacology, University of North Carolina Chapel Hill School of Medicine, Chapel Hill, NC, 27514, USA
| | - Zhaoda Zhang
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, 149 Thirteenth Street, Suite 2301, Charlestown, MA, 02129, USA
| | - Georges El Fakhri
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 3rd Avenue, Charlestown, MA, 02129, USA
| | - Marc D Normandin
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 3rd Avenue, Charlestown, MA, 02129, USA
| | - Anna-Liisa Brownell
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, 3rd Avenue, Charlestown, MA, 02129, USA.
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