1
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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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2
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Wang X, Chen C, Yan J, Xu Y, Pan D, Wang L, Yang M. Druggability of Targets for Diagnostic Radiopharmaceuticals. ACS Pharmacol Transl Sci 2023; 6:1107-1119. [PMID: 37588760 PMCID: PMC10425999 DOI: 10.1021/acsptsci.3c00081] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Indexed: 08/18/2023]
Abstract
Targets play an indispensable and pivotal role in the development of radiopharmaceuticals. However, the initial stages of drug discovery projects are often plagued by frequent failures due to inadequate information on druggability and suboptimal target selection. In this context, we aim to present a comprehensive review of the factors that influence target druggability for diagnostic radiopharmaceuticals. Specifically, we explore the crucial determinants of target specificity, abundance, localization, and positivity rate and their respective implications. Through a detailed analysis of existing protein targets, we elucidate the significance of each factor. By carefully considering and balancing these factors during the selection of targets, more efficacious and targeted radiopharmaceuticals are expected to be designed for the diagnosis of a wide range of diseases in the future.
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Affiliation(s)
- Xinyu Wang
- NHC
Key Laboratory of Nuclear Medicine, Jiangsu Key Laboratory of Molecular
Nuclear Medicine, Jiangsu Institute of Nuclear
Medicine, Wuxi 214063, PR China
- School
of Pharmacy, Nanjing Medical University, Nanjing 211166, PR China
| | - Chongyang Chen
- NHC
Key Laboratory of Nuclear Medicine, Jiangsu Key Laboratory of Molecular
Nuclear Medicine, Jiangsu Institute of Nuclear
Medicine, Wuxi 214063, PR China
| | - Junjie Yan
- NHC
Key Laboratory of Nuclear Medicine, Jiangsu Key Laboratory of Molecular
Nuclear Medicine, Jiangsu Institute of Nuclear
Medicine, Wuxi 214063, PR China
- School
of Pharmacy, Nanjing Medical University, Nanjing 211166, PR China
| | - Yuping Xu
- NHC
Key Laboratory of Nuclear Medicine, Jiangsu Key Laboratory of Molecular
Nuclear Medicine, Jiangsu Institute of Nuclear
Medicine, Wuxi 214063, PR China
- School
of Pharmacy, Nanjing Medical University, Nanjing 211166, PR China
| | - Donghui Pan
- NHC
Key Laboratory of Nuclear Medicine, Jiangsu Key Laboratory of Molecular
Nuclear Medicine, Jiangsu Institute of Nuclear
Medicine, Wuxi 214063, PR China
| | - Lizhen Wang
- NHC
Key Laboratory of Nuclear Medicine, Jiangsu Key Laboratory of Molecular
Nuclear Medicine, Jiangsu Institute of Nuclear
Medicine, Wuxi 214063, PR China
| | - Min Yang
- NHC
Key Laboratory of Nuclear Medicine, Jiangsu Key Laboratory of Molecular
Nuclear Medicine, Jiangsu Institute of Nuclear
Medicine, Wuxi 214063, PR China
- School
of Pharmacy, Nanjing Medical University, Nanjing 211166, PR China
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3
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Lee DW, Kwon JI, Heo H, Woo CW, Yu NH, Kim KW, Woo DC. Cerebral Glutamate Alterations Using Chemical Exchange Saturation Transfer Imaging in a Rat Model of Lipopolysaccharide-Induced Sepsis. Metabolites 2023; 13:metabo13050636. [PMID: 37233677 DOI: 10.3390/metabo13050636] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Revised: 04/26/2023] [Accepted: 05/06/2023] [Indexed: 05/27/2023] Open
Abstract
Glutamate-weighted chemical exchange saturation transfer (GluCEST) is a useful imaging tool to detect glutamate signal alterations caused by neuroinflammation. This study aimed to visualize and quantitatively evaluate hippocampal glutamate alterations in a rat model of sepsis-induced brain injury using GluCEST and proton magnetic resonance spectroscopy (1H-MRS). Twenty-one Sprague Dawley rats were divided into three groups (sepsis-induced groups (SEP05, n = 7 and SEP10, n = 7) and controls (n = 7)). Sepsis was induced through a single intraperitoneal injection of lipopolysaccharide (LPS) at a dose of 5 mg/kg (SEP05) or 10 mg/kg (SEP10). GluCEST values and 1H-MRS concentrations in the hippocampal region were quantified using conventional magnetization transfer ratio asymmetry and a water scaling method, respectively. In addition, we examined immunohistochemical and immunofluorescence staining to observe the immune response and activity in the hippocampal region after LPS exposure. The GluCEST and 1H-MRS results showed that GluCEST values and glutamate concentrations were significantly higher in sepsis-induced rats than those in controls as the LPS dose increased. GluCEST imaging may be a helpful technique for defining biomarkers to estimate glutamate-related metabolism in sepsis-associated diseases.
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Affiliation(s)
- Do-Wan Lee
- Department of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505, Republic of Korea
| | - Jae-Im Kwon
- Department of Medical Science, Asan Medical Institute of Convergence Science and Technology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505, Republic of Korea
- Nonclinical Research Center, QuBEST BIO Inc., Giheung-gu, Yongin-si 17015, Gyeonggi-do, Republic of Korea
| | - Hwon Heo
- Department of Convergence Medicine, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505, Republic of Korea
| | - Chul-Woong Woo
- Convergence Medicine Research Center, Asan Institute for Life Sciences, Asan Medical Center, Seoul 05505, Republic of Korea
| | - Na Hee Yu
- Nonclinical Research Center, QuBEST BIO Inc., Giheung-gu, Yongin-si 17015, Gyeonggi-do, Republic of Korea
| | - Kyung Won Kim
- Department of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505, Republic of Korea
- Department of Medical Science, Asan Medical Institute of Convergence Science and Technology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505, Republic of Korea
| | - Dong-Cheol Woo
- Department of Medical Science, Asan Medical Institute of Convergence Science and Technology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505, Republic of Korea
- Department of Convergence Medicine, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505, Republic of Korea
- Convergence Medicine Research Center, Asan Institute for Life Sciences, Asan Medical Center, Seoul 05505, Republic of Korea
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4
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McGrath T, Baskerville R, Rogero M, Castell L. Emerging Evidence for the Widespread Role of Glutamatergic Dysfunction in Neuropsychiatric Diseases. Nutrients 2022; 14:nu14050917. [PMID: 35267893 PMCID: PMC8912368 DOI: 10.3390/nu14050917] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Revised: 02/06/2022] [Accepted: 02/15/2022] [Indexed: 02/04/2023] Open
Abstract
The monoamine model of depression has long formed the basis of drug development but fails to explain treatment resistance or associations with stress or inflammation. Recent animal research, clinical trials of ketamine (a glutamate receptor antagonist), neuroimaging research, and microbiome studies provide increasing evidence of glutamatergic dysfunction in depression and other disorders. Glutamatergic involvement across diverse neuropathologies including psychoses, neurodevelopmental, neurodegenerative conditions, and brain injury forms the rationale for this review. Glutamate is the brain's principal excitatory neurotransmitter (NT), a metabolic and synthesis substrate, and an immune mediator. These overlapping roles and multiple glutamate NT receptor types complicate research into glutamate neurotransmission. The glutamate microcircuit comprises excitatory glutamatergic neurons, astrocytes controlling synaptic space levels, through glutamate reuptake, and inhibitory GABA interneurons. Astroglia generate and respond to inflammatory mediators. Glutamatergic microcircuits also act at the brain/body interface via the microbiome, kynurenine pathway, and hypothalamus-pituitary-adrenal axis. Disruption of excitatory/inhibitory homeostasis causing neuro-excitotoxicity, with neuronal impairment, causes depression and cognition symptoms via limbic and prefrontal regions, respectively. Persistent dysfunction reduces neuronal plasticity and growth causing neuronal death and tissue atrophy in neurodegenerative diseases. A conceptual overview of brain glutamatergic activity and peripheral interfacing is presented, including the common mechanisms that diverse diseases share when glutamate homeostasis is disrupted.
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Affiliation(s)
- Thomas McGrath
- Green Templeton College, University of Oxford, Oxford OX2 6HG, UK; (T.M.); (L.C.)
| | - Richard Baskerville
- Faculty of Health and Life Sciences, Oxford Brookes University, Oxford OX3 0BP, UK
- Correspondence:
| | - Marcelo Rogero
- School of Public Health, University of Sao Paulo, Sao Paulo 01246-904, Brazil;
| | - Linda Castell
- Green Templeton College, University of Oxford, Oxford OX2 6HG, UK; (T.M.); (L.C.)
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5
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Khoodoruth MAS, Estudillo-Guerra MA, Pacheco-Barrios K, Nyundo A, Chapa-Koloffon G, Ouanes S. Glutamatergic System in Depression and Its Role in Neuromodulatory Techniques Optimization. Front Psychiatry 2022; 13:886918. [PMID: 35492692 PMCID: PMC9047946 DOI: 10.3389/fpsyt.2022.886918] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Accepted: 03/28/2022] [Indexed: 11/17/2022] Open
Abstract
Depressive disorders are among the most common psychiatric conditions and contribute to significant morbidity. Even though the use of antidepressants revolutionized the management of depression and had a tremendous positive impact on the patient's outcome, a significant proportion of patients with major depressive disorder (MDD) show no or partial or response even with adequate treatment. Given the limitations of the prevailing monoamine hypothesis-based pharmacotherapy, glutamate and glutamatergic related pathways may offer an alternative and a complementary option for designing novel intervention strategies. Over the past few decades, there has been a growing interest in understanding the neurobiological underpinnings of glutamatergic dysfunctions in the pathogenesis of depressive disorders and the development of new pharmacological and non-pharmacological treatment options. There is a growing body of evidence for the efficacy of neuromodulation techniques, including transcranial magnetic stimulation, transcutaneous direct current stimulation, transcranial alternating current stimulation, and photo-biomodulation on improving connectivity and neuroplasticity associated with depression. This review attempts to revisit the role of glutamatergic neurotransmission in the etiopathogenesis of depressive disorders and review the current neuroimaging, neurophysiological and clinical evidence of these neuromodulation techniques in the pathophysiology and treatment of depression.
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Affiliation(s)
| | - Maria Anayali Estudillo-Guerra
- Department of Physical Medicine and Rehabilitation, Harvard Medical School, Spaulding Rehabilitation Hospital, Boston, MA, United States
| | - Kevin Pacheco-Barrios
- Neuromodulation Center and Center for Clinical Research Learning, Harvard Medical School, Spaulding Rehabilitation Hospital and Massachusetts General Hospital, Boston, MA, United States.,Universidad San Ignacio de Loyola, Vicerrectorado de Investigación, Unidad de Investigación para la Generación y Síntesis de Evidencias en Salud, Lima, Peru
| | - Azan Nyundo
- Department of Psychiatry and Mental Health, School of Medicine and Dental Health, The University of Dodoma, Dodoma, Tanzania
| | | | - Sami Ouanes
- Department of Psychiatry, Hamad Medical Corporation, Doha, Qatar
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6
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Wahl RL, Chareonthaitawee P, Clarke B, Drzezga A, Lindenberg L, Rahmim A, Thackeray J, Ulaner GA, Weber W, Zukotynski K, Sunderland J. Mars Shot for Nuclear Medicine, Molecular Imaging, and Molecularly Targeted Radiopharmaceutical Therapy. J Nucl Med 2021; 62:6-14. [PMID: 33334911 DOI: 10.2967/jnumed.120.253450] [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: 07/13/2020] [Accepted: 09/23/2020] [Indexed: 02/06/2023] Open
Abstract
The Society of Nuclear Medicine and Molecular Imaging created the Value Initiative in 2017 as a major component of its strategic plan to further demonstrate the value of molecular imaging and molecularly targeted radiopharmaceutical therapy to patients, physicians, payers, and funding agencies. The research and discovery domain, 1 of 5 under the Value Initiative, has a goal of advancing the research and development of diagnostic and therapeutic nuclear medicine. Research and discovery efforts and achievements are essential to ensure a bright future for NM and to translate science to practice. Given the remarkable progress in the field, leaders from the research and discovery domain and society councils identified 5 broad areas of opportunity with potential for substantive growth and clinical impact. This article discusses these 5 growth areas, identifying specific areas of particularly high importance for future study and development. As there was an understanding that goals should be both visionary yet achievable, this effort was called the Mars shot for nuclear medicine.
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Affiliation(s)
- Richard L Wahl
- Mallinckrodt Institute of Radiology, Washington University St. Louis, Missouri
| | | | - Bonnie Clarke
- Research and Discovery, Society of Nuclear Medicine and Molecular Imaging, Reston, Virginia
| | - Alexander Drzezga
- Department of Nuclear Medicine, University of Cologne, Cologne, Germany, German Center for Neurodegenerative Diseases, Bonn-Cologne, Germany, and Institute of Neuroscience and Medicine, Molecular Organization of the Brain, Forschungszentrum Jülich, Jülich, Germany
| | - Liza Lindenberg
- Molecular Imaging Program, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland
| | - Arman Rahmim
- Departments of Radiology and Physics, University of British Columbia, Vancouver, British Columbia, Canada; Department of Integrative Oncology, BC Cancer Research Institute, Vancouver, British Columbia, Canada
| | - James Thackeray
- Department of Nuclear Medicine, Hannover Medical School, Hannover, Germany
| | - Gary A Ulaner
- Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, New York, and Molecular Imaging and Therapy, Hoag Cancer Center, Newport Beach, California
| | - Wolfgang Weber
- Department of Nuclear Medicine, Technical University Munich, Munich, Germany
| | - Katherine Zukotynski
- Departments of Medicine and Radiology, McMaster University, Hamilton, Ontario, Canada; and
| | - John Sunderland
- Departments of Radiology and Physics, University of Iowa, Iowa City, Iowa
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7
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Sun JY, Kumata K, Chen Z, Zhang YD, Chen JH, Hatori A, Fu HL, Rong J, Deng XY, Yamasaki T, Xie L, Hu K, Fujinaga M, Yu QZ, Shao T, Collier TL, Josephson L, Shao YH, Du YF, Wang L, Xu H, Zhang MR, Liang SH. Synthesis and preliminary evaluation of novel 11C-labeled GluN2B-selective NMDA receptor negative allosteric modulators. Acta Pharmacol Sin 2021; 42:491-498. [PMID: 32661351 PMCID: PMC8027431 DOI: 10.1038/s41401-020-0456-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Accepted: 06/03/2020] [Indexed: 12/30/2022] Open
Abstract
N-methyl-D-aspartate receptors (NMDARs) play critical roles in the physiological function of the mammalian central nervous system (CNS), including learning, memory, and synaptic plasticity, through modulating excitatory neurotransmission. Attributed to etiopathology of various CNS disorders and neurodegenerative diseases, GluN2B is one of the most well-studied subtypes in preclinical and clinical studies on NMDARs. Herein, we report the synthesis and preclinical evaluation of two 11C-labeled GluN2B-selective negative allosteric modulators (NAMs) containing N,N-dimethyl-2-(1H-pyrrolo[3,2-b]pyridin-1-yl)acetamides for positron emission tomography (PET) imaging. Two PET ligands, namely [11C]31 and [11C]37 (also called N2B-1810 and N2B-1903, respectively) were labeled with [11C]CH3I in good radiochemical yields (decay-corrected 28% and 32% relative to starting [11C]CO2, respectively), high radiochemical purity (>99%) and high molar activity (>74 GBq/μmol). In particular, PET ligand [11C]31 demonstrated moderate specific binding to GluN2B subtype by in vitro autoradiography studies. However, because in vivo PET imaging studies showed limited brain uptake of [11C]31 (up to 0.5 SUV), further medicinal chemistry and ADME optimization are necessary for this chemotype attributed to low binding specificity and rapid metabolism in vivo.
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Affiliation(s)
- Ji-Yun Sun
- Center of Cyclotron and PET Radiopharmaceuticals, Department of Nuclear Medicine and PET/CT-MRI Center, the First Affiliated Hospital of Jinan University, Guangzhou, 510630, China
- Department of Radiology, Division of Nuclear Medicine and Molecular Imaging Massachusetts General Hospital and Harvard Medical School, 55 Fruit Street, Boston, MA, 02114, USA
| | - Katsushi Kumata
- Department of Advanced Nuclear Medicine Sciences, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, 263-8555, Japan
| | - Zhen Chen
- Department of Radiology, Division of Nuclear Medicine and Molecular Imaging Massachusetts General Hospital and Harvard Medical School, 55 Fruit Street, Boston, MA, 02114, USA
| | - Yi-Ding Zhang
- Department of Advanced Nuclear Medicine Sciences, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, 263-8555, Japan
| | - Jia-Hui Chen
- Center of Cyclotron and PET Radiopharmaceuticals, Department of Nuclear Medicine and PET/CT-MRI Center, the First Affiliated Hospital of Jinan University, Guangzhou, 510630, China
- Department of Radiology, Division of Nuclear Medicine and Molecular Imaging Massachusetts General Hospital and Harvard Medical School, 55 Fruit Street, Boston, MA, 02114, USA
| | - Akiko Hatori
- Department of Advanced Nuclear Medicine Sciences, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, 263-8555, Japan
| | - Hua-Long Fu
- Department of Radiology, Division of Nuclear Medicine and Molecular Imaging Massachusetts General Hospital and Harvard Medical School, 55 Fruit Street, Boston, MA, 02114, USA
| | - Jian Rong
- Department of Radiology, Division of Nuclear Medicine and Molecular Imaging Massachusetts General Hospital and Harvard Medical School, 55 Fruit Street, Boston, MA, 02114, USA
| | - Xiao-Yun Deng
- Department of Radiology, Division of Nuclear Medicine and Molecular Imaging Massachusetts General Hospital and Harvard Medical School, 55 Fruit Street, Boston, MA, 02114, USA
| | - Tomoteru Yamasaki
- Department of Advanced Nuclear Medicine Sciences, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, 263-8555, Japan
| | - Lin Xie
- Department of Advanced Nuclear Medicine Sciences, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, 263-8555, Japan
| | - Kuan Hu
- Department of Advanced Nuclear Medicine Sciences, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, 263-8555, Japan
| | - Masayuki Fujinaga
- Department of Advanced Nuclear Medicine Sciences, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, 263-8555, Japan
| | - Qing-Zhen Yu
- Department of Radiology, Division of Nuclear Medicine and Molecular Imaging Massachusetts General Hospital and Harvard Medical School, 55 Fruit Street, Boston, MA, 02114, USA
| | - Tuo Shao
- Department of Radiology, Division of Nuclear Medicine and Molecular Imaging Massachusetts General Hospital and Harvard Medical School, 55 Fruit Street, Boston, MA, 02114, USA
| | - Thomas Lee Collier
- Department of Radiology, Division of Nuclear Medicine and Molecular Imaging Massachusetts General Hospital and Harvard Medical School, 55 Fruit Street, Boston, MA, 02114, USA
| | - Lee Josephson
- Department of Radiology, Division of Nuclear Medicine and Molecular Imaging Massachusetts General Hospital and Harvard Medical School, 55 Fruit Street, Boston, MA, 02114, USA
| | - Yi-Han Shao
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, OK, 73019, USA
| | - Yun-Fei Du
- Tianjin Key Laboratory for Modern Drug Delivery & High-Efficiency, School of Pharmaceutical Science and Technology, Tianjin University, Tianjin, 300072, China
| | - Lu Wang
- Center of Cyclotron and PET Radiopharmaceuticals, Department of Nuclear Medicine and PET/CT-MRI Center, the First Affiliated Hospital of Jinan University, Guangzhou, 510630, China
- Department of Radiology, Division of Nuclear Medicine and Molecular Imaging Massachusetts General Hospital and Harvard Medical School, 55 Fruit Street, Boston, MA, 02114, USA
| | - Hao Xu
- Center of Cyclotron and PET Radiopharmaceuticals, Department of Nuclear Medicine and PET/CT-MRI Center, the First Affiliated Hospital of Jinan University, Guangzhou, 510630, China.
| | - Ming-Rong Zhang
- Department of Advanced Nuclear Medicine Sciences, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, 263-8555, Japan.
| | - Steven H Liang
- Department of Radiology, Division of Nuclear Medicine and Molecular Imaging Massachusetts General Hospital and Harvard Medical School, 55 Fruit Street, Boston, MA, 02114, USA.
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8
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He Y, Whitehead DM, Briard E, Numao S, Mu L, Schibli R, Ametamey SM, Auberson YP. Evaluation of 5H-Thiazolo[3,2-α]pyrimidin-5-ones as Potential GluN2A PET Tracers. ChemMedChem 2020; 15:2448-2461. [PMID: 32544308 DOI: 10.1002/cmdc.202000340] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Indexed: 11/10/2022]
Abstract
We describe here our efforts to develop a PET tracer for imaging GluN2A-containing NMDA receptors, based on a 5H-thiazolo[3,2-α]pyrimidin-5-one scaffold. The metabolic stability and overall properties could be optimized satisfactorily, although binding affinities remained a limiting factor for in vivo imaging. We nevertheless identified 7-(((2-fluoroethyl)(3-fluorophenyl)amino)-methyl)-3-(2-(hydroxymethyl)cyclopropyl)-2-methyl-5H-thiazolo-[3,2-α]pyrimidin-5-one ([18 F]7b) as a radioligand providing good-quality images in autoradiographic studies, as well as a tritiated derivative, 2-(7-(((2-fluoroethyl)(4-fluorophenyl)amino)methyl)-2-methyl-5-oxo-5H-thiazolo[3,2-α]pyrimidin-3-yl)cyclopropane-1-carbonitrile ([3 H2 ]15b), which was used for the successful development of a radioligand binding assay. These are valuable new tools for the study of GluN2A-containing NMDA receptors, and for the optimization of allosteric modulators binding to the pharmacophore located at the dimer interface of the GluN1-GluN2A ligand-binding domain.
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Affiliation(s)
- Yingfang He
- Department of Chemistry and Applied Biosciences ETH Zürich, Vladimir-Prelog-Weg 4, 8093, Zürich, Switzerland
| | - David M Whitehead
- Global Discovery Chemistry, Novartis Institutes for BioMedical Research, Fabrikstrasse 2, 4056, Basel, Switzerland
| | - Emmanuelle Briard
- Global Discovery Chemistry, Novartis Institutes for BioMedical Research, Fabrikstrasse 2, 4056, Basel, Switzerland
| | - Shin Numao
- Chemical Biology & Therapeutics, Novartis Institutes for BioMedical Research, Fabrikstrasse 2, 4056, Basel, Switzerland
| | - Linjing Mu
- Department of Chemistry and Applied Biosciences ETH Zürich, Vladimir-Prelog-Weg 4, 8093, Zürich, Switzerland
| | - Roger Schibli
- Department of Chemistry and Applied Biosciences ETH Zürich, Vladimir-Prelog-Weg 4, 8093, Zürich, Switzerland
| | - Simon M Ametamey
- Department of Chemistry and Applied Biosciences ETH Zürich, Vladimir-Prelog-Weg 4, 8093, Zürich, Switzerland
| | - Yves P Auberson
- Global Discovery Chemistry, Novartis Institutes for BioMedical Research, Fabrikstrasse 2, 4056, Basel, Switzerland
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9
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Kim JH, Marton J, Ametamey SM, Cumming P. A Review of Molecular Imaging of Glutamate Receptors. Molecules 2020; 25:molecules25204749. [PMID: 33081223 PMCID: PMC7587586 DOI: 10.3390/molecules25204749] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 10/13/2020] [Accepted: 10/14/2020] [Indexed: 12/22/2022] Open
Abstract
Molecular imaging with positron emission tomography (PET) and single photon emission computed tomography (SPECT) is a well-established and important in vivo technique to evaluate fundamental biological processes and unravel the role of neurotransmitter receptors in various neuropsychiatric disorders. Specific ligands are available for PET/SPECT studies of dopamine, serotonin, and opiate receptors, but corresponding development of radiotracers for receptors of glutamate, the main excitatory neurotransmitter in mammalian brain, has lagged behind. This state of affairs has persisted despite the central importance of glutamate neurotransmission in brain physiology and in disorders such as stroke, epilepsy, schizophrenia, and neurodegenerative diseases. Recent years have seen extensive efforts to develop useful ligands for molecular imaging of subtypes of the ionotropic (N-methyl-D-aspartate (NMDA), kainate, and AMPA/quisqualate receptors) and metabotropic glutamate receptors (types I, II, and III mGluRs). We now review the state of development of radioligands for glutamate receptor imaging, placing main emphasis on the suitability of available ligands for reliable in vivo applications. We give a brief account of the radiosynthetic approach for selected molecules. In general, with the exception of ligands for the GluN2B subunit of NMDA receptors, there has been little success in developing radiotracers for imaging ionotropic glutamate receptors; failure of ligands for the PCP/MK801 binding site in vivo doubtless relates their dependence on the open, unblocked state of the ion channel. Many AMPA and kainite receptor ligands with good binding properties in vitro have failed to give measurable specific binding in the living brain. This may reflect the challenge of developing brain-penetrating ligands for amino acid receptors, compounded by conformational differences in vivo. The situation is better with respect to mGluR imaging, particularly for the mGluR5 subtype. Several successful PET ligands serve for investigations of mGluRs in conditions such as schizophrenia, depression, substance abuse and aging. Considering the centrality and diversity of glutamatergic signaling in brain function, we have relatively few selective and sensitive tools for molecular imaging of ionotropic and metabotropic glutamate receptors. Further radiopharmaceutical research targeting specific subtypes and subunits of the glutamate receptors may yet open up new investigational vistas with broad applications in basic and clinical research.
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Affiliation(s)
- Jong-Hoon Kim
- Neuroscience Research Institute, Gachon University, Incheon 21565, Korea
- Gachon Advanced Institute for Health Science and Technology, Graduate School, Incheon 21565, Korea
- Department of Psychiatry, Gil Medical Center, Gachon University College of Medicine, Gachon University, Incheon 21565, Korea
- Correspondence: (J.-H.K.); (P.C.); Tel.: +41-31-664-0498 (P.C.); Fax: +41-31-632-7663 (P.C.)
| | - János Marton
- ABX Advanced Biochemical Compounds, Biomedizinische Forschungsreagenzien GmbH, Heinrich-Glaeser-Strasse 10-14, D-1454 Radeberg, Germany;
| | - Simon Mensah Ametamey
- Centre for Radiopharmaceutical Sciences ETH-PSI-USZ, Institute of Pharmaceutical Sciences ETH, Vladimir-Prelog-Weg 4, CH-8093 Zürich, Switzerland;
| | - Paul Cumming
- Department of Nuclear Medicine, University of Bern, Inselspital, Freiburgstrasse 18, CH-3010 Bern, Switzerland
- School of Psychology and Counselling, Queensland University of Technology, Brisbane QLD 4059, Australia
- Correspondence: (J.-H.K.); (P.C.); Tel.: +41-31-664-0498 (P.C.); Fax: +41-31-632-7663 (P.C.)
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10
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Lee DW, Woo CW, Woo DC, Kim JK, Kim KW, Lee DH. Regional Mapping of Brain Glutamate Distributions Using Glutamate-Weighted Chemical Exchange Saturation Transfer Imaging. Diagnostics (Basel) 2020; 10:E571. [PMID: 32784483 PMCID: PMC7459654 DOI: 10.3390/diagnostics10080571] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 08/06/2020] [Accepted: 08/06/2020] [Indexed: 01/24/2023] Open
Abstract
PURPOSE To investigate glutamate signal distributions in multiple brain regions of a healthy rat brain using glutamate-weighted chemical exchange saturation transfer (GluCEST) imaging. METHOD The GluCEST data were obtained using a 7.0 T magnetic resonance imaging (MRI) scanner, and all data were analyzed using conventional magnetization transfer ratio asymmetry in eight brain regions (cortex, hippocampus, corpus callosum, and rest of midbrain in each hemisphere). GluCEST data acquisition was performed again one month later in five randomly selected rats to evaluate the stability of the GluCEST signal. To evaluate glutamate level changes calculated by GluCEST data, we compared the results with the concentration of glutamate acquired from 1H magnetic resonance spectroscopy (1H MRS) data in the cortex and hippocampus. RESULTS GluCEST signals showed significant differences (all p ≤ 0.001) between the corpus callosum (-1.71 ± 1.04%; white matter) and other brain regions (3.59 ± 0.41%, cortex; 5.47 ± 0.61%, hippocampus; 4.49 ± 1.11%, rest of midbrain; gray matter). The stability test of GluCEST findings for each brain region was not significantly different (all p ≥ 0.263). In line with the GluCEST results, glutamate concentrations measured by 1H MRS also appeared higher in the hippocampus (7.30 ± 0.16 μmol/g) than the cortex (6.89 ± 0.72 μmol/g). CONCLUSION Mapping of GluCEST signals in the healthy rat brain clearly visualize glutamate distributions. These findings may yield a valuable database and insights for comparing glutamate signal changes in pre-clinical brain diseases.
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Affiliation(s)
- Do-Wan Lee
- Department of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Korea; (D.-W.L.); (J.K.K.); (K.W.K.)
| | - Chul-Woong Woo
- Convergence Medicine Research Center, Asan Institute for Life Sciences, Asan Medical Center, Seoul 05505, Korea; (C.-W.W.); (D.-C.W.)
| | - Dong-Cheol Woo
- Convergence Medicine Research Center, Asan Institute for Life Sciences, Asan Medical Center, Seoul 05505, Korea; (C.-W.W.); (D.-C.W.)
- Department of Convergence Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Korea
| | - Jeong Kon Kim
- Department of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Korea; (D.-W.L.); (J.K.K.); (K.W.K.)
| | - Kyung Won Kim
- Department of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Korea; (D.-W.L.); (J.K.K.); (K.W.K.)
| | - Dong-Hoon Lee
- Department of Radiation Convergence Engineering, Yonsei University, Wonju 26493, Korea
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11
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Varlow C, Murrell E, Holland JP, Kassenbrock A, Shannon W, Liang SH, Vasdev N, Stephenson NA. Revisiting the Radiosynthesis of [ 18F]FPEB and Preliminary PET Imaging in a Mouse Model of Alzheimer's Disease. Molecules 2020; 25:molecules25040982. [PMID: 32098347 PMCID: PMC7070414 DOI: 10.3390/molecules25040982] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Revised: 02/19/2020] [Accepted: 02/20/2020] [Indexed: 11/24/2022] Open
Abstract
[18F]FPEB is a positron emission tomography (PET) radiopharmaceutical used for imaging the abundance and distribution of mGluR5 in the central nervous system (CNS). Efficient radiolabeling of the aromatic ring of [18F]FPEB has been an ongoing challenge. Herein, five metal-free precursors for the radiofluorination of [18F]FPEB were compared, namely, a chloro-, nitro-, sulfonium salt, and two spirocyclic iodonium ylide (SCIDY) precursors bearing a cyclopentyl (SPI5) and a new adamantyl (SPIAd) auxiliary. The chloro- and nitro-precursors resulted in a low radiochemical yield (<10% RCY), whereas both SCIDY precursors and the sulfonium salt precursor produced [18F]FPEB in the highest RCYs of 25% and 36%, respectively. Preliminary PET/CT imaging studies with [18F]FPEB were conducted in a transgenic model of Alzheimer’s Disease (AD) using B6C3-Tg(APPswe,PSEN1dE9)85Dbo/J (APP/PS1) mice, and data were compared with age-matched wild-type (WT) B6C3F1/J control mice. In APP/PS1 mice, whole brain distribution at 5 min post-injection showed a slightly higher uptake (SUV = 4.8 ± 0.4) than in age-matched controls (SUV = 4.0 ± 0.2). Further studies to explore mGluR5 as an early biomarker for AD are underway.
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Affiliation(s)
- Cassis Varlow
- Azrieli Centre for Neuro-Radiochemistry, Brain Health Imaging Centre, Centre for Addiction and Mental Health, Toronto, ON M5T 1R8, Canada; (C.V.); (E.M.); (W.S.)
- Institute of Medical Science, University of Toronto, Toronto, ON M5S1A8, Canada
| | - Emily Murrell
- Azrieli Centre for Neuro-Radiochemistry, Brain Health Imaging Centre, Centre for Addiction and Mental Health, Toronto, ON M5T 1R8, Canada; (C.V.); (E.M.); (W.S.)
| | - Jason P. Holland
- Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital & Department of Radiology, Harvard Medical School, Boston, MA 02114, USA; (J.P.H.); (A.K.); (S.H.L.)
- Department of Chemistry, University of Zurich, 8057 Zurich, Switzerland
| | - Alina Kassenbrock
- Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital & Department of Radiology, Harvard Medical School, Boston, MA 02114, USA; (J.P.H.); (A.K.); (S.H.L.)
| | - Whitney Shannon
- Azrieli Centre for Neuro-Radiochemistry, Brain Health Imaging Centre, Centre for Addiction and Mental Health, Toronto, ON M5T 1R8, Canada; (C.V.); (E.M.); (W.S.)
- Department of Chemistry, University of Saskatchewan, Saskatoon, SK S7N OX2, Canada
| | - Steven H. Liang
- Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital & Department of Radiology, Harvard Medical School, Boston, MA 02114, USA; (J.P.H.); (A.K.); (S.H.L.)
| | - Neil Vasdev
- Azrieli Centre for Neuro-Radiochemistry, Brain Health Imaging Centre, Centre for Addiction and Mental Health, Toronto, ON M5T 1R8, Canada; (C.V.); (E.M.); (W.S.)
- Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital & Department of Radiology, Harvard Medical School, Boston, MA 02114, USA; (J.P.H.); (A.K.); (S.H.L.)
- Department of Psychiatry, University of Toronto, Toronto, ON M5T-1R8, Canada
- Correspondence: (N.V.); (N.A.S.); Tel.: +416-535-8501 (ext. 30988) (N.V.); +1-876-927-1910 (N.A.S.)
| | - Nickeisha A. Stephenson
- Azrieli Centre for Neuro-Radiochemistry, Brain Health Imaging Centre, Centre for Addiction and Mental Health, Toronto, ON M5T 1R8, Canada; (C.V.); (E.M.); (W.S.)
- Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital & Department of Radiology, Harvard Medical School, Boston, MA 02114, USA; (J.P.H.); (A.K.); (S.H.L.)
- Department of Chemistry, The University of West Indies at Mona, Kingston 7, Jamaica
- Correspondence: (N.V.); (N.A.S.); Tel.: +416-535-8501 (ext. 30988) (N.V.); +1-876-927-1910 (N.A.S.)
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12
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Beaurain M, Salabert AS, Ribeiro MJ, Arlicot N, Damier P, Le Jeune F, Demonet JF, Payoux P. Innovative Molecular Imaging for Clinical Research, Therapeutic Stratification, and Nosography in Neuroscience. Front Med (Lausanne) 2019; 6:268. [PMID: 31828073 PMCID: PMC6890558 DOI: 10.3389/fmed.2019.00268] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Accepted: 11/01/2019] [Indexed: 01/06/2023] Open
Abstract
Over the past few decades, several radiotracers have been developed for neuroimaging applications, especially in PET. Because of their low steric hindrance, PET radionuclides can be used to label molecules that are small enough to cross the blood brain barrier, without modifying their biological properties. As the use of 11C is limited by its short physical half-life (20 min), there has been an increasing focus on developing tracers labeled with 18F for clinical use. The first such tracers allowed cerebral blood flow and glucose metabolism to be measured, and the development of molecular imaging has since enabled to focus more closely on specific targets such as receptors, neurotransmitter transporters, and other proteins. Hence, PET and SPECT biomarkers have become indispensable for innovative clinical research. Currently, the treatment options for a number of pathologies, notably neurodegenerative diseases, remain only supportive and symptomatic. Treatments that slow down or reverse disease progression are therefore the subject of numerous studies, in which molecular imaging is proving to be a powerful tool. PET and SPECT biomarkers already make it possible to diagnose several neurological diseases in vivo and at preclinical stages, yielding topographic, and quantitative data about the target. As a result, they can be used for assessing patients' eligibility for new treatments, or for treatment follow-up. The aim of the present review was to map major innovative radiotracers used in neuroscience, and explain their contribution to clinical research. We categorized them according to their target: dopaminergic, cholinergic or serotoninergic systems, β-amyloid plaques, tau protein, neuroinflammation, glutamate or GABA receptors, or α-synuclein. Most neurological disorders, and indeed mental disorders, involve the dysfunction of one or more of these targets. Combinations of molecular imaging biomarkers can afford us a better understanding of the mechanisms underlying disease development over time, and contribute to early detection/screening, diagnosis, therapy delivery/monitoring, and treatment follow-up in both research and clinical settings.
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Affiliation(s)
- Marie Beaurain
- CHU de Toulouse, Toulouse, France.,ToNIC, Toulouse NeuroImaging Center, Inserm U1214, Toulouse, France
| | - Anne-Sophie Salabert
- CHU de Toulouse, Toulouse, France.,ToNIC, Toulouse NeuroImaging Center, Inserm U1214, Toulouse, France
| | - Maria Joao Ribeiro
- UMR 1253, iBrain, Université de Tours, Inserm, Tours, France.,Inserm CIC 1415, University Hospital, Tours, France.,CHRU Tours, Tours, France
| | - Nicolas Arlicot
- UMR 1253, iBrain, Université de Tours, Inserm, Tours, France.,Inserm CIC 1415, University Hospital, Tours, France.,CHRU Tours, Tours, France
| | - Philippe Damier
- Inserm U913, Neurology Department, University Hospital, Nantes, France
| | | | - Jean-François Demonet
- Leenards Memory Centre, Department of Clinical Neuroscience, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
| | - Pierre Payoux
- CHU de Toulouse, Toulouse, France.,ToNIC, Toulouse NeuroImaging Center, Inserm U1214, Toulouse, France
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13
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Fu H, Tang W, Chen Z, Belov VV, Zhang G, Shao T, Zhang X, Yu Q, Rong J, Deng X, Han W, Myers SJ, Giffenig P, Wang L, Josephson L, Shao Y, Davenport AT, Daunais JB, Papisov M, Yuan H, Li Z, Traynelis SF, Liang SH. Synthesis and Preliminary Evaluations of a Triazole-Cored Antagonist as a PET Imaging Probe ([ 18F]N2B-0518) for GluN2B Subunit in the Brain. ACS Chem Neurosci 2019; 10:2263-2275. [PMID: 30698943 PMCID: PMC6727982 DOI: 10.1021/acschemneuro.8b00591] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
GluN2B is the most studied subunit of N-methyl-d-aspartate receptors (NMDARs) and implicated in the pathologies of various central nervous system disorders and neurodegenerative diseases. As pan NMDAR antagonists often produce debilitating side effects, new approaches in drug discovery have shifted to subtype-selective NMDAR modulators, especially GluN2B-selective antagonists. While positron emission tomography (PET) studies of GluN2B-selective NMDARs in the living brain would enable target engagement in drug development and improve our understanding in the NMDAR signaling pathways between normal and disease conditions, a suitable PET ligand is yet to be identified. Herein we developed an 18F-labeled potent antagonist, 2-((1-(4-[18F]fluoro-3-methylphenyl)-1 H-1,2,3-triazol-4-yl)methoxy)-5-methoxypyrimidine ([18F]13; also called [18F]N2B-0518) as a PET tracer for imaging the GluN2B subunit. The radiofluorination of [18F]13 was efficiently achieved by our spirocyclic iodonium ylide (SCIDY) method. In in vitro autoradiography studies, [18F]13 displayed highly region-specific binding in brain sections of rat and nonhuman primate, which was in accordance with the expression of GluN2B subunit. Ex vivo biodistribution in mice revealed that [18F]13 could penetrate the blood-brain barrier with moderate brain uptake (3.60% ID/g at 2 min) and rapid washout. Altogether, this work provides a GluN2B-selective PET tracer bearing a new chemical scaffold and shows high specificity to GluN2B subunit in vitro, which may pave the way for the development of a new generation of GluN2B PET ligands.
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Affiliation(s)
- Hualong Fu
- Department of Radiology, Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital and Harvard Medical School, 55 Fruit Street, Boston, Massachusetts 02114, United States
| | - Weiting Tang
- Department of Pharmacology, Emory University School of Medicine, Atlanta, Georgia 30322, United States
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, 410008, P. R. China
| | - Zhen Chen
- Department of Radiology, Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital and Harvard Medical School, 55 Fruit Street, Boston, Massachusetts 02114, United States
| | - Vasily V. Belov
- Department of Radiology, Massachusetts General Hospital, Harvard Medical School, and the Shriners Burns Hospital, Boston, Massachusetts 02114, United States
| | - Genwei Zhang
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, Oklahoma 73019, United States
| | - Tuo Shao
- Department of Radiology, Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital and Harvard Medical School, 55 Fruit Street, Boston, Massachusetts 02114, United States
| | - Xiaofei Zhang
- Department of Radiology, Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital and Harvard Medical School, 55 Fruit Street, Boston, Massachusetts 02114, United States
| | - Qingzhen Yu
- Department of Radiology, Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital and Harvard Medical School, 55 Fruit Street, Boston, Massachusetts 02114, United States
| | - Jian Rong
- Department of Radiology, Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital and Harvard Medical School, 55 Fruit Street, Boston, Massachusetts 02114, United States
| | - Xiaoyun Deng
- Department of Radiology, Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital and Harvard Medical School, 55 Fruit Street, Boston, Massachusetts 02114, United States
| | - Wei Han
- Department of Pharmacology, Emory University School of Medicine, Atlanta, Georgia 30322, United States
- Department of Neurology, Children’s Hospital of Chongqing Medical University, Chongqing, 400014, P. R. China
| | - Scott J. Myers
- Department of Pharmacology, Emory University School of Medicine, Atlanta, Georgia 30322, United States
| | - Pilar Giffenig
- Department of Radiology, Massachusetts General Hospital, Harvard Medical School, and the Shriners Burns Hospital, Boston, Massachusetts 02114, United States
| | - Lu Wang
- Department of Radiology, Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital and Harvard Medical School, 55 Fruit Street, Boston, Massachusetts 02114, United States
- Department of Nuclear Medicine and PET/CT-MRI Center, the First Affiliated Hospital of Jinan University & Institute of Molecular and Functional Imaging, Jinan University, Guangzhou 510630, P. R. China
| | - Lee Josephson
- Department of Radiology, Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital and Harvard Medical School, 55 Fruit Street, Boston, Massachusetts 02114, United States
| | - Yihan Shao
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, Oklahoma 73019, United States
| | - April T. Davenport
- Department of Physiology and Pharmacology, Wake Forest School of Medicine, Winston Salem, North Carolina 27157, United States
| | - James B. Daunais
- Department of Physiology and Pharmacology, Wake Forest School of Medicine, Winston Salem, North Carolina 27157, United States
| | - Mikhail Papisov
- Department of Radiology, Massachusetts General Hospital, Harvard Medical School, and the Shriners Burns Hospital, Boston, Massachusetts 02114, United States
| | - Hongjie Yuan
- Department of Pharmacology, Emory University School of Medicine, Atlanta, Georgia 30322, United States
| | - Zijing Li
- State Key Laboratory of Molecular Vaccinology, Molecular Diagnosis & Center for Molecular Imaging and Translational Medicine, School of Public Health, Xiamen University, Xiamen 361102, P. R. China
| | - Stephen F. Traynelis
- Department of Pharmacology, Emory University School of Medicine, Atlanta, Georgia 30322, United States
| | - Steven H. Liang
- Department of Radiology, Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital and Harvard Medical School, 55 Fruit Street, Boston, Massachusetts 02114, United States
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14
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Fu H, Chen Z, Josephson L, Li Z, Liang SH. Positron Emission Tomography (PET) Ligand Development for Ionotropic Glutamate Receptors: Challenges and Opportunities for Radiotracer Targeting N-Methyl-d-aspartate (NMDA), α-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid (AMPA), and Kainate Receptors. J Med Chem 2019; 62:403-419. [PMID: 30110164 PMCID: PMC6393217 DOI: 10.1021/acs.jmedchem.8b00714] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Ionotropic glutamate receptors (iGluRs) mediate excitatory neurotransmission within the mammalian central nervous system. iGluRs exist as three main groups: N-methyl-d-aspartate receptors (NMDARs), α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (AMPARs), and kainate receptors. The past decades have witnessed a remarkable development of PET tracers targeting different iGluRs including NMDARs and AMPARs, and several of the tracers have advanced to clinical imaging studies. Here, we assess the recent development of iGluR PET probes, focusing on tracer design, brain kinetics, and performance in PET imaging studies. Furthermore, this review will not only present challenges in the tracer development but also provide novel approaches in conjunction with most recent drug discovery efforts on these iGluRs, including subtype-selective NMDAR and transmembrane AMPAR regulatory protein modulators and positive allosteric modulators (PAMs) of AMPARs. These approaches, if successful as PET tracers, may provide fundamental knowledge to understand the roles of iGluR receptors under physiological and pathological conditions.
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Affiliation(s)
- Hualong Fu
- Division of Nuclear Medicine and Molecular Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, 55 Fruit St., Boston, MA 02114 USA
| | - Zhen Chen
- Division of Nuclear Medicine and Molecular Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, 55 Fruit St., Boston, MA 02114 USA
| | - Lee Josephson
- Division of Nuclear Medicine and Molecular Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, 55 Fruit St., Boston, MA 02114 USA
| | - Zijing Li
- State Key Laboratory of Molecular Vaccinology, Molecular Diagnosis & Center for Molecular Imaging and Translational Medicine, School of Public Health, Xiamen University, Xiamen 361102, P. R. China
| | - Steven H. Liang
- Division of Nuclear Medicine and Molecular Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, 55 Fruit St., Boston, MA 02114 USA
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15
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Franco Machado J, Silva RD, Melo R, G Correia JD. Less Exploited GPCRs in Precision Medicine: Targets for Molecular Imaging and Theranostics. Molecules 2018; 24:E49. [PMID: 30583594 PMCID: PMC6337414 DOI: 10.3390/molecules24010049] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2018] [Revised: 12/07/2018] [Accepted: 12/09/2018] [Indexed: 12/18/2022] Open
Abstract
Precision medicine relies on individually tailored therapeutic intervention taking into account individual variability. It is strongly dependent on the availability of target-specific drugs and/or imaging agents that recognize molecular targets and patient-specific disease mechanisms. The most sensitive molecular imaging modalities, Single Photon Emission Computed Tomography (SPECT) and Positron Emission Tomography (PET), rely on the interaction between an imaging radioprobe and a target. Moreover, the use of target-specific molecular tools for both diagnostics and therapy, theranostic agents, represent an established methodology in nuclear medicine that is assuming an increasingly important role in precision medicine. The design of innovative imaging and/or theranostic agents is key for further accomplishments in the field. G-protein-coupled receptors (GPCRs), apart from being highly relevant drug targets, have also been largely exploited as molecular targets for non-invasive imaging and/or systemic radiotherapy of various diseases. Herein, we will discuss recent efforts towards the development of innovative imaging and/or theranostic agents targeting selected emergent GPCRs, namely the Frizzled receptor (FZD), Ghrelin receptor (GHSR-1a), G protein-coupled estrogen receptor (GPER), and Sphingosine-1-phosphate receptor (S1PR). The pharmacological and clinical relevance will be highlighted, giving particular attention to the studies on the synthesis and characterization of targeted molecular imaging agents, biological evaluation, and potential clinical applications in oncology and non-oncology diseases. Whenever relevant, supporting computational studies will be also discussed.
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Affiliation(s)
- João Franco Machado
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, CTN, Estrada Nacional 10 (km 139,7), 2695-066 Bobadela LRS, Portugal.
- Centro de Química Estrutural, Faculdade de Ciências, Universidade de Lisboa, 1749-016 Lisboa, Portugal.
| | - Rúben D Silva
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, CTN, Estrada Nacional 10 (km 139,7), 2695-066 Bobadela LRS, Portugal.
| | - Rita Melo
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, CTN, Estrada Nacional 10 (km 139,7), 2695-066 Bobadela LRS, Portugal.
- Center for Neuroscience and Cell Biology; Rua Larga, Faculdade de Medicina, Polo I, 1ºandar, Universidade de Coimbra, 3004-504 Coimbra, Portugal.
| | - João D G Correia
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, CTN, Estrada Nacional 10 (km 139,7), 2695-066 Bobadela LRS, Portugal.
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16
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Zhou W, Bao W, Jiang D, Kong Y, Hua F, Lu X, Guan Y. [18F]-GE-179 positron emission tomography (PET) tracer for N-methyl-d-aspartate receptors: One-pot synthesis and preliminary micro-PET study in a rat model of MCAO. Nucl Med Biol 2018; 61:45-55. [DOI: 10.1016/j.nucmedbio.2018.04.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Revised: 03/14/2018] [Accepted: 04/10/2018] [Indexed: 12/23/2022]
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17
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Imaging the glutamate receptor subtypes-Much achieved, and still much to do. DRUG DISCOVERY TODAY. TECHNOLOGIES 2017; 25:27-36. [PMID: 29233264 DOI: 10.1016/j.ddtec.2017.10.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Revised: 10/17/2017] [Accepted: 10/24/2017] [Indexed: 11/20/2022]
Abstract
Functional imaging of glutamate receptors using PET imaging modality can be used to study numerous CNS disorders and also to select appropriate doses of clinically relevant glutamate-receptor-targeting candidate drugs. Great strides have been made in developing PET imaging probes for the non-invasive detection of glutamate receptors in the brain. This review highlights recent progress made towards the development of glutamatergic PET imaging agents. Focus is placed on PET imaging probes that have been labelled with either carbon-11 or fluorine-18.
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18
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Yang H, Tam B, Čolović M, Southcott L, Merkens H, Bénard F, Schaffer P. Addressing Chirality in the Structure and Synthesis of [18
F]5-Fluoroaminosuberic Acid ([18
F]FASu). Chemistry 2017; 23:11100-11107. [PMID: 28744973 DOI: 10.1002/chem.201702007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Indexed: 11/07/2022]
Affiliation(s)
- Hua Yang
- Life Sciences; TRIUMF; 4004 Wesbrook Mall V6T 2A3 Vancouver Canada
| | - Brian Tam
- Life Sciences; TRIUMF; 4004 Wesbrook Mall V6T 2A3 Vancouver Canada
| | - Milena Čolović
- The British Columbia Cancer Agency; 675 West 10 Ave. V5Z 1L3 Vancouver Canada
- Department of Radiology; University of British Columbia; 3350-950 West 10 Ave. V5Z 1L9 Vancouver Canada
| | - Lily Southcott
- Life Sciences; TRIUMF; 4004 Wesbrook Mall V6T 2A3 Vancouver Canada
| | - Helen Merkens
- The British Columbia Cancer Agency; 675 West 10 Ave. V5Z 1L3 Vancouver Canada
| | - François Bénard
- The British Columbia Cancer Agency; 675 West 10 Ave. V5Z 1L3 Vancouver Canada
- Department of Radiology; University of British Columbia; 3350-950 West 10 Ave. V5Z 1L9 Vancouver Canada
| | - Paul Schaffer
- Life Sciences; TRIUMF; 4004 Wesbrook Mall V6T 2A3 Vancouver Canada
- Department of Radiology; University of British Columbia; 3350-950 West 10 Ave. V5Z 1L9 Vancouver Canada
- Department of Chemistry; University of Simon Fraser; 8888 University Drive V5A 1S6 Vancouver Canada
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19
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Klein PJ, Schuit RC, Metaxas A, Christiaans JAM, Kooijman E, Lammertsma AA, van Berckel BNM, Windhorst AD. Synthesis, radiolabeling and preclinical evaluation of a [ 11C]GMOM derivative as PET radiotracer for the ion channel of the N-methyl-D-aspartate receptor. Nucl Med Biol 2017; 51:25-32. [PMID: 28528265 DOI: 10.1016/j.nucmedbio.2017.05.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Revised: 03/29/2017] [Accepted: 05/04/2017] [Indexed: 12/22/2022]
Abstract
INTRODUCTION Presently available PET ligands for the NMDAr ion channel generally suffer from fast metabolism. The purpose of this study was to develop a metabolically more stable ligand for the NMDAr ion channel, taking [11C]GMOM ([11C]1) as the lead compound. METHODS [11C]1, its fluoralkyl analogue [18F]PK209 ([18F]2) and the newly synthesized fluorovinyloxy analogue [11C]7b were evaluated ex vivo in male Wistar rats for metabolic stability. In addition, [11C]7b was subjected to a biodistribution study and its affinity (Ki) and lipophilicity (logD7.4) values were determined. RESULTS The addition of a vinyl chain in the fluoromethoxy moiety did not negatively alter the affinity of [11C]7b for the NMDAr, while lipophilicity was increased. Biodistribution studies showed higher uptake of [11C]7b in forebrain regions compared with cerebellum. Pre-treatment with MK-801 decreased the overall brain uptake significantly, but not in a region-specific manner. 45min after injection 78, 90 and 87% of activity in the brain was due to parent compound for [11C]1, [18F]2 and [11C]7b, respectively. In plasma, 26-31% of activity was due to parent compound. CONCLUSION Complete substitution of the alpha-carbon increased lipophilicity to more favorable values. Substitution of one or more hydrogens of the alpha-carbon atom in the methoxy moiety improved metabolic stability. In plasma, more parent compound was found for [18F]2 and [11C]7b then for [11C]1, although differences were not significant. At 45min, significantly more parent [18F]2 and [11C]7b was measured in the brain compared with [11C]1.
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Affiliation(s)
- Pieter J Klein
- Department of Radiology & Nuclear Medicine, Neuroscience Campus Amsterdam, VU University Medical Center, P.O. Box 7057, 1007 MB Amsterdam, The Netherlands.
| | - Robert C Schuit
- Department of Radiology & Nuclear Medicine, Neuroscience Campus Amsterdam, VU University Medical Center, P.O. Box 7057, 1007 MB Amsterdam, The Netherlands
| | - Athanasios Metaxas
- Department of Radiology & Nuclear Medicine, Neuroscience Campus Amsterdam, VU University Medical Center, P.O. Box 7057, 1007 MB Amsterdam, The Netherlands
| | - Johannes A M Christiaans
- Department of Radiology & Nuclear Medicine, Neuroscience Campus Amsterdam, VU University Medical Center, P.O. Box 7057, 1007 MB Amsterdam, The Netherlands
| | - Esther Kooijman
- Department of Radiology & Nuclear Medicine, Neuroscience Campus Amsterdam, VU University Medical Center, P.O. Box 7057, 1007 MB Amsterdam, The Netherlands
| | - Adriaan A Lammertsma
- Department of Radiology & Nuclear Medicine, Neuroscience Campus Amsterdam, VU University Medical Center, P.O. Box 7057, 1007 MB Amsterdam, The Netherlands
| | - Bart N M van Berckel
- Department of Radiology & Nuclear Medicine, Neuroscience Campus Amsterdam, VU University Medical Center, P.O. Box 7057, 1007 MB Amsterdam, The Netherlands
| | - Albert D Windhorst
- Department of Radiology & Nuclear Medicine, Neuroscience Campus Amsterdam, VU University Medical Center, P.O. Box 7057, 1007 MB Amsterdam, The Netherlands
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Menke RAL, Agosta F, Grosskreutz J, Filippi M, Turner MR. Neuroimaging Endpoints in Amyotrophic Lateral Sclerosis. Neurotherapeutics 2017; 14:11-23. [PMID: 27752938 PMCID: PMC5233627 DOI: 10.1007/s13311-016-0484-9] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative, clinically heterogeneous syndrome pathologically overlapping with frontotemporal dementia. To date, therapeutic trials in animal models have not been able to predict treatment response in humans, and the revised ALS Functional Rating Scale, which is based on coarse disability measures, remains the gold-standard measure of disease progression. Advances in neuroimaging have enabled mapping of functional, structural, and molecular aspects of ALS pathology, and these objective measures may be uniquely sensitive to the detection of propagation of pathology in vivo. Abnormalities are detectable before clinical symptoms develop, offering the potential for neuroprotective intervention in familial cases. Although promising neuroimaging biomarker candidates for diagnosis, prognosis, and disease progression have emerged, these have been from the study of necessarily select patient cohorts identified in specialized referral centers. Further multicenter research is now needed to establish their validity as therapeutic outcome measures.
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Affiliation(s)
- Ricarda A L Menke
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Federica Agosta
- Neuroimaging Research Unit, Institute of Experimental Neurology, Division of Neuroscience, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Milan, Italy
| | - Julian Grosskreutz
- Hans-Berger Department of Neurology, Jena University Hospital, Jena, Germany
| | - Massimo Filippi
- Neuroimaging Research Unit, Institute of Experimental Neurology, Division of Neuroscience, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Milan, Italy
- Department of Neurology, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Milan, Italy
| | - Martin R Turner
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK.
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Metabotropic glutamate receptor 5 – a promising target in drug development and neuroimaging. Eur J Nucl Med Mol Imaging 2016; 43:1151-70. [DOI: 10.1007/s00259-015-3301-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2015] [Accepted: 12/22/2015] [Indexed: 10/22/2022]
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Comparative assessment of parametric neuroreceptor mapping approaches based on the simplified reference tissue model using [¹¹C]ABP688 PET. J Cereb Blood Flow Metab 2015; 35:2098-108. [PMID: 26243707 PMCID: PMC4671133 DOI: 10.1038/jcbfm.2015.190] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Revised: 06/17/2015] [Accepted: 07/02/2015] [Indexed: 11/08/2022]
Abstract
In recent years, several linearized model approaches for fast and reliable parametric neuroreceptor mapping based on dynamic nuclear imaging have been developed from the simplified reference tissue model (SRTM) equation. All the methods share the basic SRTM assumptions, but use different schemes to alleviate the effect of noise in dynamic-image voxels. Thus, this study aimed to compare those approaches in terms of their performance in parametric image generation. We used the basis function method and MRTM2 (multilinear reference tissue model with two parameters), which require a division process to obtain the distribution volume ratio (DVR). In addition, a linear model with the DVR as a model parameter (multilinear SRTM) was used in two forms: one based on linear least squares and the other based on extension of total least squares (TLS). Assessment using simulated and actual dynamic [(11)C]ABP688 positron emission tomography data revealed their equivalence with the SRTM, except for different noise susceptibilities. In the DVR image production, the two multilinear SRTM approaches achieved better image quality and regional compatibility with the SRTM than the others, with slightly better performance in the TLS-based method.
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Wierońska JM, Zorn SH, Doller D, Pilc A. Metabotropic glutamate receptors as targets for new antipsychotic drugs: Historical perspective and critical comparative assessment. Pharmacol Ther 2015; 157:10-27. [PMID: 26549541 DOI: 10.1016/j.pharmthera.2015.10.007] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
In this review, we aim to present, discuss and clarify our current understanding regarding the prediction of possible antipsychotic effects of metabotropic glutamate (mGlu) receptor ligands. The number of preclinical trials clearly indicates, that this group of compounds constitutes an excellent alternative to presently used antipsychotic therapy, being effective not only to positive, but also negative and cognitive symptoms of schizophrenia. Although the results of clinical trials that were performed for the group of mGlu2/3 agonists were not so enthusiastic as in animal studies, they still showed that mGlu ligands do not induced variety of side effects typical for presently used antipsychotics, and were generally well tolerated. The lack of satisfactory effectiveness towards schizophrenia symptoms of mGlu2/3 activators in humans could be a result of variety of uncontrolled factors and unidentified biomarkers different for each schizophrenia patient, that should be taken into consideration in the future set of clinical trials. The subject is still open for further research, and the novel classes of mGlu5 or mGlu2/3 agonists/PAMs were recently introduced, including the large group of compounds from the third group of mGlu receptors, especially of mGlu4 subtype. Finally, more precise treatment based on simultaneous administration of minimal doses of the ligands for two or more receptors, seems to be promising in the context of symptoms-specific schizophrenia treatment.
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Affiliation(s)
- Joanna M Wierońska
- Institute of Pharmacology, Polish Academy of Sciences, 31-343 Krakow, Poland
| | | | | | - Andrzej Pilc
- Institute of Pharmacology, Polish Academy of Sciences, 31-343 Krakow, Poland.
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Salabert AS, Fonta C, Fontan C, Adel D, Alonso M, Pestourie C, Belhadj-Tahar H, Tafani M, Payoux P. Radiolabeling of [18F]-fluoroethylnormemantine and initial in vivo evaluation of this innovative PET tracer for imaging the PCP sites of NMDA receptors. Nucl Med Biol 2015; 42:643-53. [PMID: 25963911 DOI: 10.1016/j.nucmedbio.2015.04.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Revised: 03/19/2015] [Accepted: 04/01/2015] [Indexed: 01/01/2023]
Abstract
INTRODUCTION The N-methyl-D-aspartate receptor (NMDAr) is an ionotropic receptor that mediates excitatory transmission. NMDAr overexcitation is thought to be involved in neurological and neuropsychiatric disorders such as Alzheimer disease and schizophrenia. We synthesized [(18)F]-fluoroethylnormemantine ([(18)F]-FNM), a memantine derivative that binds to phencyclidine (PCP) sites within the NMDA channel pore. These sites are primarily accessible when the channel is in the active and open state. METHODS Radiosynthesis was carried out using the Raytest® SynChrom R&D fluorination module. Affinity of this new compound was determined by competition assay. We ran a kinetic study in rats and computed a time-activity curve based on a volume-of-interest analysis, using CARIMAS® software. We performed an ex vivo autoradiography, exposing frozen rat brain sections to a phosphorscreen. Adjacent sections were used to detect NMDAr by immunohistochemistry with an anti-NR1 antibody. As a control of the specificity of our compound for NMDAr, we used a rat anesthetized with ketamine. Correlation analysis was performed with ImageJ software between signal of autoradiography and immunostaining. RESULTS Fluorination yield was 10.5% (end of synthesis), with a mean activity of 3145 MBq and a specific activity above 355 GBq/μmol. Affinity assessment allowed us to determine [(19)F]-FNM IC50 at 6.1 10(-6)M. [(18)F]-FMN concentration gradually increased in the brain, stabilizing at 40 minutes post injection. The brain-to-blood ratio was 6, and 0.4% of the injected dose was found in the brain. Combined ex vivo autoradiography and immunohistochemical staining demonstrated colocalization of NMDAr and [(18)F]-FNM (r=0.622, p<0.0001). The highest intensity was found in the cortex and cerebellum, and the lowest in white matter. A low and homogeneous signal corresponding to unspecific binding was observed when PCP sites were blocked with ketamine. CONCLUSIONS [(18)F]-FNM appears to be a promising tracer for imaging NMDAr activity for undertaking preclinical studies in perspective of clinical detection of neurological or neuropsychological disorders.
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Affiliation(s)
- Anne-Sophie Salabert
- Brain Imaging and Neurological Disability UMR 825, INSERM, F-31059 Toulouse, France; Brain imaging and neurological disability UMR 825, University of Toulouse, UPS, CHU Purpan, Place du Dr Baylac, F-31059 Toulouse Cedex 9, France; Radiopharmacy Department, University Hospital, Toulouse, France.
| | - Caroline Fonta
- Research Center for Brain and Cognition, University of Toulouse UPS, Toulouse, France; CerCo, CNRS, Toulouse, France
| | - Charlotte Fontan
- Brain Imaging and Neurological Disability UMR 825, INSERM, F-31059 Toulouse, France; Brain imaging and neurological disability UMR 825, University of Toulouse, UPS, CHU Purpan, Place du Dr Baylac, F-31059 Toulouse Cedex 9, France; Radiopharmacy Department, University Hospital, Toulouse, France
| | - Djilali Adel
- Brain Imaging and Neurological Disability UMR 825, INSERM, F-31059 Toulouse, France; Brain imaging and neurological disability UMR 825, University of Toulouse, UPS, CHU Purpan, Place du Dr Baylac, F-31059 Toulouse Cedex 9, France
| | - Mathieu Alonso
- Radiopharmacy Department, University Hospital, Toulouse, France
| | | | - Hafid Belhadj-Tahar
- Research and Expertise Group, French Association for the Promotion of Medical Research (AFPREMED), Toulouse, France
| | - Mathieu Tafani
- Brain Imaging and Neurological Disability UMR 825, INSERM, F-31059 Toulouse, France; Brain imaging and neurological disability UMR 825, University of Toulouse, UPS, CHU Purpan, Place du Dr Baylac, F-31059 Toulouse Cedex 9, France; Radiopharmacy Department, University Hospital, Toulouse, France
| | - Pierre Payoux
- Brain Imaging and Neurological Disability UMR 825, INSERM, F-31059 Toulouse, France; Brain imaging and neurological disability UMR 825, University of Toulouse, UPS, CHU Purpan, Place du Dr Baylac, F-31059 Toulouse Cedex 9, France; Nuclear Medicine Department, University Hospital, Toulouse, France
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25
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Stephenson NA, Holland JP, Kassenbrock A, Yokell DL, Livni E, Liang SH, Vasdev N. Iodonium ylide-mediated radiofluorination of 18F-FPEB and validation for human use. J Nucl Med 2015; 56:489-92. [PMID: 25655630 DOI: 10.2967/jnumed.114.151332] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
UNLABELLED Translation of new methodologies for labeling nonactivated aromatic molecules with (18)F remains a challenge. Here, we report a one-step, regioselective, metal-free (18)F-labeling method that uses a hypervalent iodonium(III) ylide precursor, to prepare the radiopharmaceutical (18)F-3-fluoro-5-[(pyridin-3-yl)ethynyl]benzonitrile ((18)F-FPEB). METHODS Automated radiosynthesis of (18)F-FPEB was achieved by reaction of the ylide precursor (4 mg) with (18)F-Et4NF in dimethylformamide at 80°C for 5 min and formulated for injection within 1 h. RESULTS (18)F-FPEB was synthesized in 20% ± 5% (n = 3) uncorrected radiochemical yields relative to (18)F-fluoride, with specific activities of 666 ± 51.8 GBq (18 ± 1.4 Ci)/μmol at the end of synthesis and was validated for human use. CONCLUSION Radiofluorination of iodonium (III) ylides proved to be an efficient radiosynthetic strategy for synthesis of (18)F-labeled radiopharmaceuticals.
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Affiliation(s)
- Nickeisha A Stephenson
- Division of Nuclear Medicine and Molecular Imaging, Center for Advanced Medical Imaging Sciences, Massachusetts General Hospital, Boston, Massachusetts; and Department of Radiology, Harvard Medical School, Boston, Massachusetts
| | - Jason P Holland
- Department of Radiology, Harvard Medical School, Boston, Massachusetts
| | - Alina Kassenbrock
- Division of Nuclear Medicine and Molecular Imaging, Center for Advanced Medical Imaging Sciences, Massachusetts General Hospital, Boston, Massachusetts; and
| | - Daniel L Yokell
- Division of Nuclear Medicine and Molecular Imaging, Center for Advanced Medical Imaging Sciences, Massachusetts General Hospital, Boston, Massachusetts; and
| | - Eli Livni
- Division of Nuclear Medicine and Molecular Imaging, Center for Advanced Medical Imaging Sciences, Massachusetts General Hospital, Boston, Massachusetts; and Department of Radiology, Harvard Medical School, Boston, Massachusetts
| | - Steven H Liang
- Division of Nuclear Medicine and Molecular Imaging, Center for Advanced Medical Imaging Sciences, Massachusetts General Hospital, Boston, Massachusetts; and Department of Radiology, Harvard Medical School, Boston, Massachusetts
| | - Neil Vasdev
- Division of Nuclear Medicine and Molecular Imaging, Center for Advanced Medical Imaging Sciences, Massachusetts General Hospital, Boston, Massachusetts; and Department of Radiology, Harvard Medical School, Boston, Massachusetts
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Rook JM, Tantawy MN, Ansari MS, Felts AS, Stauffer SR, Emmitte KA, Kessler RM, Niswender CM, Daniels JS, Jones CK, Lindsley CW, Conn PJ. Relationship between in vivo receptor occupancy and efficacy of metabotropic glutamate receptor subtype 5 allosteric modulators with different in vitro binding profiles. Neuropsychopharmacology 2015; 40:755-65. [PMID: 25241804 PMCID: PMC4289965 DOI: 10.1038/npp.2014.245] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/14/2014] [Revised: 09/06/2014] [Accepted: 09/09/2014] [Indexed: 11/09/2022]
Abstract
Allosteric modulators of the metabotropic glutamate receptor subtype 5 (mGlu5) have exciting potential as therapeutic agents for multiple brain disorders. Translational studies with mGlu5 modulators have relied on mGlu5 allosteric site positron emission tomography (PET) radioligands to assess receptor occupancy in the brain. However, recent structural and modeling studies suggest that closely related mGlu5 allosteric modulators can bind to overlapping but not identical sites, which could complicate interpretation of in vivo occupancy data, even when PET ligands and drug leads are developed from the same chemical scaffold. We now report that systemic administration of the novel mGlu5 positive allosteric modulator VU0092273 displaced the structurally related mGlu5 PET ligand, [(18)F]FPEB, with measures of in vivo occupancy that closely aligned with its in vivo efficacy. In contrast, a close analog of VU0092273 and [(18)F]FPEB, VU0360172, provided robust efficacy in rodent models in the absence of detectable occupancy. Furthermore, a structurally unrelated mGlu5 negative allosteric modulator, VU0409106, displayed measures of in vivo occupancy that correlated well with behavioral effects, despite the fact that VU0409106 is structurally unrelated to [(18)F]FPEB. Interestingly, all three compounds inhibit radioligand binding to the prototypical MPEP/FPEB allosteric site in vitro. However, VU0092273 and VU0409106 bind to this site in a fully competitive manner, whereas the interaction of VU0360172 is noncompetitive. Thus, while close structural similarity between PET ligands and drug leads does not circumvent issues associated with differential binding to a given target, detailed molecular pharmacology analysis accurately predicts utility of ligand pairs for in vivo occupancy studies.
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Affiliation(s)
- Jerri M Rook
- Department of Pharmacology and Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Mohammed N Tantawy
- Vanderbilt University Institute of Imaging Sciences, Nashville, TN, USA,Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Mohammad S Ansari
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Andrew S Felts
- Department of Pharmacology and Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Shaun R Stauffer
- Department of Pharmacology and Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, TN, USA,Department of Chemistry, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Kyle A Emmitte
- Department of Pharmacology and Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, TN, USA,Department of Chemistry, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Robert M Kessler
- Department of Radiology, University of Alabama, Birmingham, AL, USA
| | - Colleen M Niswender
- Department of Pharmacology and Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, TN, USA
| | - J Scott Daniels
- Department of Pharmacology and Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Carrie K Jones
- Department of Pharmacology and Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Craig W Lindsley
- Department of Pharmacology and Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, TN, USA,Department of Chemistry, Vanderbilt University Medical Center, Nashville, TN, USA
| | - P Jeffrey Conn
- Department of Pharmacology and Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, TN, USA,Department of Pharmacology and Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, 1215D Light Hall, 2215-B Garland Avenue, Nashville, TN 37232-0697, USA, Tel: +1 615 936 2478, Fax: +1 615 343 3088, E-mail:
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Abstract
The glutamate and dopamine hypotheses are leading theories of the pathoaetiology of schizophrenia. Both were initially based on indirect evidence from pharmacological studies supported by post-mortem findings, but have since been substantially advanced by new lines of evidence from in vivo imaging studies. This review provides an update on the latest findings on dopamine and glutamate abnormalities in schizophrenia, focusing on in vivo neuroimaging studies in patients and clinical high-risk groups, and considers their implications for understanding the biology and treatment of schizophrenia. These findings have refined both the dopamine and glutamate hypotheses, enabling greater anatomical and functional specificity, and have been complemented by preclinical evidence showing how the risk factors for schizophrenia impact on the dopamine and glutamate systems. The implications of this new evidence for understanding the development and treatment of schizophrenia are considered, and the gaps in current knowledge highlighted. Finally, the evidence for an integrated model of the interactions between the glutamate and dopamine systems is reviewed, and future directions discussed.
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Affiliation(s)
- Oliver Howes
- Psychiatric Imaging, MRC Clinical Sciences Centre, Hammersmith Hospital, London, UK Institute of Psychiatry, King's College London, London, UK
| | - Rob McCutcheon
- Psychiatric Imaging, MRC Clinical Sciences Centre, Hammersmith Hospital, London, UK Institute of Psychiatry, King's College London, London, UK
| | - James Stone
- Psychiatric Imaging, MRC Clinical Sciences Centre, Hammersmith Hospital, London, UK Institute of Psychiatry, King's College London, London, UK
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Sim N, Parker D. Critical design issues in the targeted molecular imaging of cell surface receptors. Chem Soc Rev 2015; 44:2122-34. [DOI: 10.1039/c4cs00364k] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The molecular imaging of cell-surface receptors draws closer to reality.
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Affiliation(s)
- Neil Sim
- Department of Chemistry
- Durham University
- Durham DH1 3LE
- UK
| | - David Parker
- Department of Chemistry
- Durham University
- Durham DH1 3LE
- UK
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Yang H, Miao Q, Johnson BF, Rishel MJ, Sossi V, Dinelle K, Bénard. F, Yapp DT, Webster JM, Schaffer P. A simple route to [11C]N-Me labeling of aminosuberic acid for proof of feasibility imaging of the xC− transporter. Bioorg Med Chem Lett 2014; 24:5512-5. [DOI: 10.1016/j.bmcl.2014.10.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2014] [Revised: 09/27/2014] [Accepted: 10/01/2014] [Indexed: 01/01/2023]
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30
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Kim JY, Son MH, Choi K, Baek DJ, Ko MK, Lim EJ, Pae AN, Keum G, Lee JK, Cho YS, Choo H, Lee YW, Moon BS, Lee BC, Lee HY, Min SJ. Synthesis and In vivo Evaluation of 5-Methoxy-2-(phenylethynyl)quinoline (MPEQ) and [11C]MPEQ Targeting Metabotropic Glutamate Receptor 5 (mGluR5). B KOREAN CHEM SOC 2014. [DOI: 10.5012/bkcs.2014.35.8.2304] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Rojas DC. The role of glutamate and its receptors in autism and the use of glutamate receptor antagonists in treatment. J Neural Transm (Vienna) 2014; 121:891-905. [PMID: 24752754 PMCID: PMC4134390 DOI: 10.1007/s00702-014-1216-0] [Citation(s) in RCA: 123] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2013] [Accepted: 04/06/2014] [Indexed: 12/11/2022]
Abstract
Glutamate is the major excitatory neurotransmitter in the brain and may be a key neurotransmitter involved in autism. Literature pertaining to glutamate and autism or related disorders (e.g., Fragile X syndrome) is reviewed in this article. Interest in glutamatergic dysfunction in autism is high due to increasing convergent evidence implicating the system in the disorder from peripheral biomarkers, neuroimaging, protein expression, genetics and animal models. Currently, there are no pharmaceutical interventions approved for autism that address glutamate deficits in the disorder. New treatments related to glutamatergic neurotransmission, however, are emerging. In addition, older glutamate-modulating medications with approved indications for use in other disorders are being investigated for re-tasking as treatments for autism. This review presents evidence in support of glutamate abnormalities in autism and the potential for translation into new treatments for the disorder.
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Affiliation(s)
- Donald C Rojas
- Department of Psychology, Campus Delivery 1876, Colorado State University, Fort Collins, CO, 80523, USA,
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