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Liu J, Kang J, Qi M, Tang J, Fang Y, Liu C, Hong J, Zuo J, Chen Z. Synthesis and initial evaluation of radioiodine-labelled deuterated tropane derivatives targeting dopamine transporter. Bioorg Med Chem Lett 2024; 102:129678. [PMID: 38408514 DOI: 10.1016/j.bmcl.2024.129678] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Revised: 02/21/2024] [Accepted: 02/23/2024] [Indexed: 02/28/2024]
Abstract
The dopamine transporter (DAT) is closely related to a variety of neurological disorders including Parkinson's disease (PD) and other neurodegenerative diseases. In vivo imaging of DAT with radio-labelled tracers has become a powerful technique in related disorders. The radioiodine-labelled tropane derivative [123I]FP-CIT ([123I]1a) is widely used in clinical single photon emission computed tomography (SPECT) imaging as a DAT imaging agent. To develop more metabolically stable DAT radioligands for accurate imaging, this work compared two novel deuterated tropane derivatives ([131I]1c-d) with non-deuterated tropane derivatives ([131I]1a-b). [131I]1a-d were obtained in high radiochemical purity (RCP) above 99 % with molar activities of 7.0-10.0 GBq/μmol. The [131I]1a and [131I]1c exhibited relatively higher affinity to DAT (Ki: 2.0-3.12 nM) than [131I]1b and [131I]1d. Biodistribution results showed that [131I]1c consistently exhibited a higher ratio of the target to non-target (striatum/cerebellum) than [131I]1a. Furthermore, metabolism studies indicated that the in vivo metabolic stability of [131I]1c was superior to that of [131I]1a. Ex vivo autoradiography showed that [131I]1c selectively localized on DAT-rich striatal regions and the specific signal could be blocked by DAT inhibitor. These results indicated that [131I]1c might be a potential probe for DAT SPECT imaging in the brain.
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Affiliation(s)
- Jie Liu
- Department of Radiopharmaceuticals, School of Pharmacy, Nanjing Medical University, Nanjing 211166, China; NHC Key Laboratory of Nuclear Medicine, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi 214063, China
| | - Jing Kang
- Department of Radiopharmaceuticals, School of Pharmacy, Nanjing Medical University, Nanjing 211166, China; NHC Key Laboratory of Nuclear Medicine, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi 214063, China
| | - Meihui Qi
- NHC Key Laboratory of Nuclear Medicine, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi 214063, China; School of Pharmaceutical Science, Inner Mongolia Medical University, Hohhot 010110, China
| | - Jie Tang
- NHC Key Laboratory of Nuclear Medicine, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi 214063, China
| | - Yi Fang
- NHC Key Laboratory of Nuclear Medicine, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi 214063, China
| | - Chunyi Liu
- NHC Key Laboratory of Nuclear Medicine, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi 214063, China
| | - Jingjing Hong
- NHC Key Laboratory of Nuclear Medicine, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi 214063, China; Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, School of Pharmacy, Xuzhou Medical University, Xuzhou 221004, China
| | - Jiaojiao Zuo
- NHC Key Laboratory of Nuclear Medicine, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi 214063, China; School of Pharmaceutical Science, Inner Mongolia Medical University, Hohhot 010110, China
| | - Zhengping Chen
- Department of Radiopharmaceuticals, School of Pharmacy, Nanjing Medical University, Nanjing 211166, China; NHC Key Laboratory of Nuclear Medicine, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi 214063, China; School of Pharmaceutical Science, Inner Mongolia Medical University, Hohhot 010110, China; Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, School of Pharmacy, Xuzhou Medical University, Xuzhou 221004, China.
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2
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Xu Y, Peremans K, Salden S, Audenaert K, Dobbeleir A, Van Eeckhaut A, De Bundel D, Saunders JH, Baeken C. Accelerated high frequency rTMS induces time-dependent dopaminergic alterations: a DaTSCAN brain imaging study in healthy beagle dogs. Front Vet Sci 2023; 10:1154596. [PMID: 37261109 PMCID: PMC10228829 DOI: 10.3389/fvets.2023.1154596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Accepted: 05/03/2023] [Indexed: 06/02/2023] Open
Abstract
Aim The neurobiological effects of repetitive transcranial magnetic stimulation are believed to run in part through the dopaminergic system. Accelerated high frequency rTMS (aHF-rTMS), a new form of stimuli delivery, is currently being tested for its usefulness in treating human and canine mental disorders. However, the short-and long-term neurobiological effects are still unclear, including the effects on the dopaminergic system. In aHF-rTMS, multiple sessions are delivered within 1 day instead of one session per day, not only to accelerate the time to response but also to increase clinical efficacy. To gain more insight into the neurobiology of aHF-rTMS, we investigated whether applying five sessions in 1 day has direct and/or delayed effects on the dopamine transporter (DAT), and on dopamine metabolites of cerebrospinal fluid (CSF) in beagles. Materials and methods Thirteen beagles were randomly divided into two groups: five active stimulation sessions (n = 9), and 5 sham stimulation sessions (n = 4). Using DaTSCAN, DAT binding indices (BI) were obtained at baseline, after 1 day, 1 month, and 3 months post stimulation. CSF samples were collected after each scan. Results Active aHF-rTMS significantly reduced striatal DAT BI 1 day post-active stimulation session (p < 0.01), and the effect lasted to 1 month (p < 0.01). No significant DAT BI change was found in sham group. No significant changes in dopamine metabolites of CSF were found. Conclusion Although no significant effects on CSF dopamine metabolites were observed, five sessions of active aHF-rTMS significantly decreased striatal DAT BI after 1 day and up to 1 month post stimulation, indicating immediate and delayed effects on the brain dopaminergic system. Our findings in healthy beagles further substantiate the assumption that (a)HF-rTMS affects the brain dopaminergic system and it may pave the way to apply (a)HF-rTMS treatment in behaviorally disturbed dogs.
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Affiliation(s)
- Yangfeng Xu
- Department of Head and Skin, Ghent Experimental Psychiatry (GHEP) Lab, Ghent University, Ghent, Belgium
- Department of Morphology, Imaging, Orthopedics, Rehabilitation and Nutrition, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Kathelijne Peremans
- Department of Morphology, Imaging, Orthopedics, Rehabilitation and Nutrition, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Sofie Salden
- Department of Morphology, Imaging, Orthopedics, Rehabilitation and Nutrition, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Kurt Audenaert
- Department of Head and Skin, Ghent Experimental Psychiatry (GHEP) Lab, Ghent University, Ghent, Belgium
| | - Andre Dobbeleir
- Department of Morphology, Imaging, Orthopedics, Rehabilitation and Nutrition, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Ann Van Eeckhaut
- Department of Pharmaceutical Chemistry, Drug Analysis and Drug Information (FASC), Research Group Experimental Pharmacology, Center for Neurosciences (C4N), Vrije Universiteit Brussel, Brussels, Belgium
| | - Dimitri De Bundel
- Department of Pharmaceutical Chemistry, Drug Analysis and Drug Information (FASC), Research Group Experimental Pharmacology, Center for Neurosciences (C4N), Vrije Universiteit Brussel, Brussels, Belgium
| | - Jimmy H Saunders
- Department of Morphology, Imaging, Orthopedics, Rehabilitation and Nutrition, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Chris Baeken
- Department of Head and Skin, Ghent Experimental Psychiatry (GHEP) Lab, Ghent University, Ghent, Belgium
- Department of Psychiatry, Vrije Universiteit Brussel, Universitair Ziekenhuis Brussel (UZBrussel), Brussels, Belgium
- Department of Electrical Engineering, Eindhoven University of Technology, Eindhoven, Netherlands
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3
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Cao S, Tang J, Liu C, Fang Y, Ji L, Xu Y, Chen Z. Synthesis and Biological Evaluation of [ 18F]FECNT-d 4 as a Novel PET Agent for Dopamine Transporter Imaging. Mol Imaging Biol 2021; 23:733-744. [PMID: 33851345 DOI: 10.1007/s11307-021-01603-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 03/21/2021] [Accepted: 04/02/2021] [Indexed: 11/27/2022]
Abstract
PURPOSE The dopamine transporter (DAT) is a marker of the occurrence and development of Parkinson's disease (PD) and other diseases with nigrostriatal degeneration. 2β-Carbomethoxy-3β-(4-chlorophenyl)-8-(2-[18F]-fluoroethyl)nortropane ([18F]FECNT), an 18F-labelled tropane derivative, was reported to be a useful positron-emitting probe for DAT. However, the rapid formation of brain-penetrating radioactive metabolites is an impediment to the proper quantitation of DAT in PET studies with [18F]FECNT. Deuterium-substituted analogues have presented better in vivo stability to reduce metabolites. This study aimed to synthesize a deuterium-substituted DAT radiotracer, [18F]FECNT-d4, and to make a preliminary investigation of its properties as a DAT tracer in vivo. PROCEDURES The ligand [18F]FECNT-d4 was obtained by one-step radiolabelling reaction. The lipophilicity was measured by the shake-flask method. Binding properties of [18F]FECNT-d4 were estimated by in vitro binding assay, biodistribution, and microPET imaging in rats. In vivo stability of [18F]FECNT-d4 was estimated by radio-HPLC. RESULTS [18F]FECNT-d4 was synthesized at an average activity yield of 46 ± 17 % (n = 15) and the molar activity was 67 ± 12 GBq/μmol. The deuterated tracer showed suitable lipophilicity and the ability to penetrate the blood-brain barrier (brain uptake of 1.72 % ID at 5 min). [18F]FECNT-d4 displayed a high binding affinity for DAT comparable to that of [18F]FECNT in rat striatum homogenates. Biodistribution results in normal rats showed that [18F]FECNT-d4 exhibited a higher ratio of the target to non-target (striatum/cerebellum) at 15 min post administration (5.00 ± 0.44 vs 3.84 ± 0.24 for [18F]FECNT-d4 vs [18F]FECNT). MicroPET imaging studies of [18F]FECNT-d4 in normal rats showed that the ligand selectively localized to DAT-rich striatal regions and the accumulation could be blocked with DAT inhibitor. Furthermore, in the unilateral PD model rat, a significant reduction of the signal was found in the lesioned side relative to the unlesioned side. Striatal standardized uptake value of [18F]FECNT-d4 remained ~4.02 in the striatum between 5 and 20 min, whereas that of [18F]FECNT fell rapidly from 4.11 to 2.95. Radio-HPLC analysis of the plasma demonstrated better in vivo stability of [18F]FECNT-d4 than [18F]FECNT. CONCLUSION The deuterated compound [18F]FECNT-d4 may serve as a promising PET imaging agent to assess DAT-related disorders.
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Affiliation(s)
- Shanshan Cao
- Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, School of Pharmacy, Xuzhou Medical University, Xuzhou, 221004, China
| | - Jie Tang
- NHC Key Laboratory of Nuclear Medicine, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi, 214063, China
| | - Chunyi Liu
- NHC Key Laboratory of Nuclear Medicine, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi, 214063, China
| | - Yi Fang
- NHC Key Laboratory of Nuclear Medicine, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi, 214063, China
| | - Linyang Ji
- Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, School of Pharmacy, Xuzhou Medical University, Xuzhou, 221004, China
| | - Yingjiao Xu
- NHC Key Laboratory of Nuclear Medicine, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi, 214063, China
| | - Zhengping Chen
- Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, School of Pharmacy, Xuzhou Medical University, Xuzhou, 221004, China. .,NHC Key Laboratory of Nuclear Medicine, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi, 214063, China.
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4
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Pees A, Windhorst AD, Vosjan MJWD, Tadino V, Vugts DJ. Synthesis of [18
F]Fluoroform with High Molar Activity. European J Org Chem 2020. [DOI: 10.1002/ejoc.202000056] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Anna Pees
- Radiology and Nuclear Medicine; Radionuclide Center; Amsterdam UMC, VU University; De Boelelaan 1085c Amsterdam The Netherlands
| | - Albert D. Windhorst
- Radiology and Nuclear Medicine; Radionuclide Center; Amsterdam UMC, VU University; De Boelelaan 1085c Amsterdam The Netherlands
| | | | - Vincent Tadino
- ORA Neptis; Rue de la Gendarmerie 50/B 5600 Philippeville Belgium
| | - Danielle J. Vugts
- Radiology and Nuclear Medicine; Radionuclide Center; Amsterdam UMC, VU University; De Boelelaan 1085c Amsterdam The Netherlands
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5
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A dopaminergic mechanism of antipsychotic drug efficacy, failure, and failure reversal: the role of the dopamine transporter. Mol Psychiatry 2020; 25:2101-2118. [PMID: 30038229 PMCID: PMC7473845 DOI: 10.1038/s41380-018-0114-5] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Revised: 04/30/2018] [Accepted: 05/25/2018] [Indexed: 12/21/2022]
Abstract
Antipsychotic drugs are effective interventions in schizophrenia. However, the efficacy of these agents often decreases over time, which leads to treatment failure and symptom recurrence. We report that antipsychotic efficacy in rat models declines in concert with extracellular striatal dopamine levels rather than insufficient dopamine D2 receptor occupancy. Antipsychotic efficacy was associated with a suppression of dopamine transporter activity, which was reversed during failure. Antipsychotic failure coincided with reduced dopamine neuron firing, which was not observed during antipsychotic efficacy. Synaptic field responses in dopamine target areas declined during antipsychotic efficacy and showed potentiation during failure. Antipsychotics blocked synaptic vesicle release during efficacy but enhanced this release during failure. We found that the pharmacological inhibition of the dopamine transporter rescued antipsychotic drug treatment outcomes, supporting the hypothesis that the dopamine transporter is a main target of antipsychotic drugs and predicting that dopamine transporter blockers may be an adjunct treatment to reverse antipsychotic treatment failure.
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Amato D, Kruyer A, Samaha AN, Heinz A. Hypofunctional Dopamine Uptake and Antipsychotic Treatment-Resistant Schizophrenia. Front Psychiatry 2019; 10:314. [PMID: 31214054 PMCID: PMC6557273 DOI: 10.3389/fpsyt.2019.00314] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Accepted: 04/23/2019] [Indexed: 01/07/2023] Open
Abstract
Antipsychotic treatment resistance in schizophrenia remains a major issue in psychiatry. Nearly 30% of patients with schizophrenia do not respond to antipsychotic treatment, yet the underlying neurobiological causes are unknown. All effective antipsychotic medications are thought to achieve their efficacy by targeting the dopaminergic system. Here we review early literature describing the fundamental mechanisms of antipsychotic drug efficacy, highlighting mechanistic concepts that have persisted over time. We then reconsider the original framework for understanding antipsychotic efficacy in light of recent advances in our scientific understanding of the dopaminergic effects of antipsychotics. Based on these new insights, we describe a role for the dopamine transporter in the genesis of both antipsychotic therapeutic response and primary resistance. We believe that this discussion will help delineate the dopaminergic nature of antipsychotic treatment-resistant schizophrenia.
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Affiliation(s)
- Davide Amato
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, United States
| | - Anna Kruyer
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, United States
| | - Anne-Noël Samaha
- Department of Pharmacology and Physiology, Faculty of Medicine, Université de Montréal, Montreal, QC, Canada
| | - Andreas Heinz
- Department of Psychiatry, Charité University Medicine Berlin, Campus Charité Mitte, Berlin, Germany
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7
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Smith CT, San Juan MD, Dang LC, Katz DT, Perkins SF, Burgess LL, Cowan RL, Manning HC, Nickels ML, Claassen DO, Samanez-Larkin GR, Zald DH. Ventral striatal dopamine transporter availability is associated with lower trait motor impulsivity in healthy adults. Transl Psychiatry 2018; 8:269. [PMID: 30531858 PMCID: PMC6286354 DOI: 10.1038/s41398-018-0328-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Revised: 11/13/2018] [Accepted: 11/15/2018] [Indexed: 12/18/2022] Open
Abstract
Impulsivity is a transdiagnostic feature of a range of externalizing psychiatric disorders. Preclinical work links reduced ventral striatal dopamine transporter (DAT) availability with heightened impulsivity and novelty seeking. However, there is a lack of human data investigating the relationship between DAT availability, particularly in subregions of the striatum, and the personality traits of impulsivity and novelty seeking. Here we collected PET measures of DAT availability (BPND) using the tracer 18F-FE-PE2I in 47 healthy adult subjects and examined relations between BPND in striatum, including its subregions: caudate, putamen, and ventral striatum (VS), and trait impulsivity (Barratt Impulsiveness Scale: BIS-11) and novelty seeking (Tridimensional Personality Questionnaire: TPQ-NS), controlling for age and sex. DAT BPND in each striatal subregion showed nominal negative associations with total BIS-11 but not TPQ-NS. At the subscale level, VS DAT BPND was significantly associated with BIS-11 motor impulsivity (e.g., taking actions without thinking) after correction for multiple comparisons. VS DAT BPND explained 13.2% of the variance in motor impulsivity. Our data demonstrate that DAT availability in VS is negatively related to impulsivity and suggest a particular influence of DAT regulation of dopamine signaling in VS on acting without deliberation (BIS motor impulsivity). While needing replication, these data converge with models of ventral striatal functions that emphasize its role as a key interface linking motivation to action.
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Affiliation(s)
- Christopher T. Smith
- 0000 0001 2264 7217grid.152326.1Department of Psychology, PMB 407817, Vanderbilt University, 2301 Vanderbilt Place, Nashville, TN 37240-7817 USA
| | - M. Danica San Juan
- 0000 0001 2264 7217grid.152326.1Department of Psychology, PMB 407817, Vanderbilt University, 2301 Vanderbilt Place, Nashville, TN 37240-7817 USA
| | - Linh C. Dang
- 0000 0001 2264 7217grid.152326.1Department of Psychology, PMB 407817, Vanderbilt University, 2301 Vanderbilt Place, Nashville, TN 37240-7817 USA
| | - Daniel T. Katz
- 0000 0001 2264 7217grid.152326.1Department of Psychology, PMB 407817, Vanderbilt University, 2301 Vanderbilt Place, Nashville, TN 37240-7817 USA
| | - Scott F. Perkins
- 0000 0001 2264 7217grid.152326.1Department of Psychology, PMB 407817, Vanderbilt University, 2301 Vanderbilt Place, Nashville, TN 37240-7817 USA
| | - Leah L. Burgess
- 0000 0001 2264 7217grid.152326.1Department of Psychology, PMB 407817, Vanderbilt University, 2301 Vanderbilt Place, Nashville, TN 37240-7817 USA
| | - Ronald L. Cowan
- 0000 0001 2264 7217grid.152326.1Department of Psychology, PMB 407817, Vanderbilt University, 2301 Vanderbilt Place, Nashville, TN 37240-7817 USA ,0000 0004 1936 9916grid.412807.8Department of Psychiatry and Behavioral Sciences, Vanderbilt University Medical Center, 1601 23rd Avenue South, Suite 3057, Nashville, TN 37212 USA ,0000 0004 1936 9916grid.412807.8Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Medical Center North, 1161 21st Avenue South, Nashville, TN 37232 USA
| | - H. Charles Manning
- 0000 0004 1936 9916grid.412807.8Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Medical Center North, 1161 21st Avenue South, Nashville, TN 37232 USA ,0000 0001 2264 7217grid.152326.1Department of Chemistry, Vanderbilt University, 7330 Stevenson Center, Station B 351822, Nashville, TN 37235 USA ,0000 0001 2264 7217grid.152326.1Department of Biomedical Engineering, PMB 351826, Vanderbilt University, 2301 Vanderbilt Place, Nashville, TN 37235-1826 USA ,0000 0004 1936 9916grid.412807.8Department of Neurological Surgery, Vanderbilt University Medical Center, 1161 21st Avenue South, T4224 Medical Center North, Nashville, TN 37232-2380 USA
| | - Michael L. Nickels
- 0000 0004 1936 9916grid.412807.8Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Medical Center North, 1161 21st Avenue South, Nashville, TN 37232 USA
| | - Daniel O. Claassen
- 0000 0004 1936 9916grid.412807.8Department of Neurology, Vanderbilt University Medical Center, 1161 21st Avenue South, A-0118, Nashville, TN 37232-2551 USA
| | - Gregory R. Samanez-Larkin
- 0000 0004 1936 7961grid.26009.3dDepartment of Psychology and Neuroscience, Duke University, 417 Chapel Drive, Durham, NC 27708 USA
| | - David H. Zald
- 0000 0001 2264 7217grid.152326.1Department of Psychology, PMB 407817, Vanderbilt University, 2301 Vanderbilt Place, Nashville, TN 37240-7817 USA ,0000 0004 1936 9916grid.412807.8Department of Psychiatry and Behavioral Sciences, Vanderbilt University Medical Center, 1601 23rd Avenue South, Suite 3057, Nashville, TN 37212 USA
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8
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Cumming P, Burgher B, Patkar O, Breakspear M, Vasdev N, Thomas P, Liu GJ, Banati R. Sifting through the surfeit of neuroinflammation tracers. J Cereb Blood Flow Metab 2018; 38:204-224. [PMID: 29256293 PMCID: PMC5951023 DOI: 10.1177/0271678x17748786] [Citation(s) in RCA: 73] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Revised: 10/26/2017] [Accepted: 11/09/2017] [Indexed: 01/09/2023]
Abstract
The first phase of molecular brain imaging of microglial activation in neuroinflammatory conditions began some 20 years ago with the introduction of [11C]-( R)-PK11195, the prototype isoquinoline ligand for translocator protein (18 kDa) (TSPO). Investigations by positron emission tomography (PET) revealed microgliosis in numerous brain diseases, despite the rather low specific binding signal imparted by [11C]-( R)-PK11195. There has since been enormous expansion of the repertoire of TSPO tracers, many with higher specific binding, albeit complicated by allelic dependence of the affinity. However, the specificity of TSPO PET for revealing microglial activation not been fully established, and it has been difficult to judge the relative merits of the competing tracers and analysis methods with respect to their sensitivity for detecting microglial activation. We therefore present a systematic comparison of 13 TSPO PET and single photon computed tomography (SPECT) tracers belonging to five structural classes, each of which has been investigated by compartmental analysis in healthy human brain relative to a metabolite-corrected arterial input. We emphasize the need to establish the non-displaceable binding component for each ligand and conclude with five recommendations for a standard approach to define the cellular distribution of TSPO signals, and to characterize the properties of candidate TSPO tracers.
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Affiliation(s)
- Paul Cumming
- School of Psychology and Counselling and IHBI, Faculty of Health, Queensland University of Technology, Brisbane, Australia
- QIMR Berghofer Institute, Brisbane, Australia
| | - Bjorn Burgher
- QIMR Berghofer Institute, Brisbane, Australia
- Metro North Mental Health Service, Brisbane, Australia
| | - Omkar Patkar
- School of Psychology and Counselling and IHBI, Faculty of Health, Queensland University of Technology, Brisbane, Australia
- QIMR Berghofer Institute, Brisbane, Australia
| | - Michael Breakspear
- QIMR Berghofer Institute, Brisbane, Australia
- Metro North Mental Health Service, Brisbane, Australia
| | - Neil Vasdev
- Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital, Boston, MA, USA
- Department of Radiology, Harvard Medical School, Boston, MA, USA
| | - Paul Thomas
- Herston Imaging Research Facility, Faculty of Medicine, University of Queensland Centre for Clinical Research, Herston, Australia
| | - Guo-Jun Liu
- Australian Nuclear Science and Technology Organisation, Lucas Heights, Australia
- National Imaging Facility, Brain and Mind Centre and Faculty of Health Sciences, University of Sydney, Camperdown, Australia
| | - Richard Banati
- Australian Nuclear Science and Technology Organisation, Lucas Heights, Australia
- National Imaging Facility, Brain and Mind Centre and Faculty of Health Sciences, University of Sydney, Camperdown, Australia
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9
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Rafique W, Khanapur S, Spilhaug MM, Riss PJ. Reaching out for Sensitive Evaluation of the Mu Opioid Receptor in Vivo: Positron Emission Tomography Imaging of the Agonist [ 11C]AH7921. ACS Chem Neurosci 2017; 8:1847-1852. [PMID: 28590714 DOI: 10.1021/acschemneuro.7b00075] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Imaging of the mu opioid receptor (MOR) availability with positron emission tomography (PET) is a pertinent challenge in Neuroscience. Both, regulation of receptor expression and occupancy by endogeneous opioids play into cognitive and behavioral phenotypes of healthy function and disease. Receptor expression in the active and inactive states can be measured using high affinity radioagonist and radioantagonist PET tracers, respectively. Occupancy assessment requires radioligands showing competitive and reversible binding with moderate affinity to the MOR, which may lead to physical extinction of the receptor specific signal in vivo. We investigated a moderately potent, selective MOR agonist in rat to test if a radiotracer design paradigm tailored to competition with endogeneous opioids leads to viable imaging results. The benzamide 3,4-dichlorobenzenecarboxylic acid (dimethylamino)cyclohexyl)methyl amide (AH-7921, 1) was synthesized and characterized in rat brain using autoradiography and positron emission tomography. Compound 1 was found to activate with low nanomolar potency the MOR and to a lesser extent KOR as a full agonist. Concentration dependent binding studies with agonist and antagonist radioligands were conducted to assess competition behavior and obtain inhibition constants. Kinetic analysis of 3,4-dichlorobenzene[11C]carboxylic acid (dimethylamino)cyclohexyl)methyl amide binding in rat brain resulted in low but reproducible binding potential in the thalamus (0.8 ± 0.1). A radioactive metabolite was detected in brain (17%, after 15 min). Nonetheless, we conclude that quantitative imaging of MOR availability is possible when using a moderate affinity radiotracer.
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Affiliation(s)
- Waqas Rafique
- realomics
SFI, Kjemisk Institutt, Universitetet i Oslo, Sem Sælands vei 26, Kjemibygningen, 0371 Oslo, Norway
| | - Shivashankar Khanapur
- realomics
SFI, Kjemisk Institutt, Universitetet i Oslo, Sem Sælands vei 26, Kjemibygningen, 0371 Oslo, Norway
- Radboud Translational Medicine BV, Geert Grooteplein
21, Postbus 9101, 6500HB Nijmegen, Netherland
| | - Mona M. Spilhaug
- realomics
SFI, Kjemisk Institutt, Universitetet i Oslo, Sem Sælands vei 26, Kjemibygningen, 0371 Oslo, Norway
| | - Patrick J. Riss
- realomics
SFI, Kjemisk Institutt, Universitetet i Oslo, Sem Sælands vei 26, Kjemibygningen, 0371 Oslo, Norway
- Klinik
for Kirurgi og Nevrofag, Oslo Universitets Sykehus HF−Rikshospitalet, Postboks
4950 Nydalen, 0424 Oslo, Norway
- Norsk Medisinsk Syklotronsenter AS, Gaustad, Postboks 4950 Nydalen, 0424 Oslo, Norway
- Radboud Translational Medicine BV, Geert Grooteplein
21, Postbus 9101, 6500HB Nijmegen, Netherland
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10
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Cross-sectional and longitudinal small animal PET shows pre and post-synaptic striatal dopaminergic deficits in an animal model of HIV. Nucl Med Biol 2017; 55:27-33. [PMID: 29031113 DOI: 10.1016/j.nucmedbio.2017.08.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2017] [Revised: 07/01/2017] [Accepted: 08/23/2017] [Indexed: 11/20/2022]
Abstract
INTRODUCTION In vivo imaging biomarkers of various HIV neuropathologies, including dopaminergic dysfunction, are still lacking. Towards developing dopaminergic biomarkers of brain involvement in HIV, we assessed the pre and postsynaptic components of the dopaminergic system in the HIV-1 transgenic rat (Tg), a well-characterized model of treated HIV+ patients, using small-animal PET imaging. METHODS Fifteen to 18 month-old Tg and wild type (WT) rats were imaged with both [18F]-FP-CMT, a dopamine transporter (DAT) ligand (n=16), and [18F]-Fallypride, a D2/D3 dopamine receptor (D2/D3DR) ligand (n=16). Five to 8 month-old Tg and WT rats (n=18) were also imaged with [18F]-FP-CMT. A subset of animals was imaged longitudinally at 7 and 17 months of age. Multiplex immunohistochemistry staining for DAT, tyrosine hydroxylase, D2DR, D3DR, GFAP, Iba1 and NeuN was performed on a subgroup of the scanned animals. RESULTS [18F]-FP-CMT and [18F]-Fallypride binding potential (BPND) values were significantly lower in 15-18 month-old Tg compared to age-matched WT rats (p<0.0001 and 0.001, respectively). [18F]-FP-CMT BPND values in 5-8 month-old rats, however, were not significantly different. Longitudinal age-related decrease in [18F]-FP-CMT BPND was exacerbated in the Tg rat. Immunohistochemistry showed decreased staining of dopaminergic markers in Tg rats. Rats with higher serum gp120 had lower mean BPND values for both ligands. CONCLUSIONS We found presynaptic and postsynaptic dopaminergic dysfunction/loss in older Tg compared to WT rats. We believe this to be related to neurotoxicity of viral proteins present in the Tg rats' serum and brain. ADVANCES IN KNOWLEDGE Our findings confirm prior reports of neurobehavioral abnormalities suggestive of dopaminergic dysfunction in this model. They also suggest similarities between the Tg rat and HIV+ patients as far as dopaminergic dysfunction. IMPLICATIONS FOR PATIENT CARE The Tg rat, along with the above-described quantitative PET imaging biomarkers, can have a role in the evaluation of HIV neuroprotective therapies prior to human translation.
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van der Born D, Pees A, Poot AJ, Orru RVA, Windhorst AD, Vugts DJ. Fluorine-18 labelled building blocks for PET tracer synthesis. Chem Soc Rev 2017; 46:4709-4773. [DOI: 10.1039/c6cs00492j] [Citation(s) in RCA: 113] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
This review presents a comprehensive overview of the synthesis and application of fluorine-18 labelled building blocks since 2010.
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Affiliation(s)
- Dion van der Born
- Department of Radiology & Nuclear Medicine
- VU University Medical Center
- 1081 HV Amsterdam
- The Netherlands
| | - Anna Pees
- Department of Radiology & Nuclear Medicine
- VU University Medical Center
- 1081 HV Amsterdam
- The Netherlands
| | - Alex J. Poot
- Department of Radiology & Nuclear Medicine
- VU University Medical Center
- 1081 HV Amsterdam
- The Netherlands
| | - Romano V. A. Orru
- Department of Chemistry and Pharmaceutical Sciences and Amsterdam Institute for Molecules
- Medicines & Systems (AIMMS)
- VU University Amsterdam
- Amsterdam
- The Netherlands
| | - Albert D. Windhorst
- Department of Radiology & Nuclear Medicine
- VU University Medical Center
- 1081 HV Amsterdam
- The Netherlands
| | - Danielle J. Vugts
- Department of Radiology & Nuclear Medicine
- VU University Medical Center
- 1081 HV Amsterdam
- The Netherlands
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Nebel N, Maschauer S, Kuwert T, Hocke C, Prante O. In Vitro and In Vivo Characterization of Selected Fluorine-18 Labeled Radioligands for PET Imaging of the Dopamine D3 Receptor. Molecules 2016; 21:molecules21091144. [PMID: 27589704 PMCID: PMC6272905 DOI: 10.3390/molecules21091144] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Revised: 08/25/2016] [Accepted: 08/26/2016] [Indexed: 02/07/2023] Open
Abstract
Cerebral dopamine D3 receptors seem to play a key role in the control of drug-seeking behavior. The imaging of their regional density with positron emission tomography (PET) could thus help in the exploration of the molecular basis of drug addiction. A fluorine-18 labeled D3 subtype selective radioligand would be beneficial for this purpose; however, as yet, there is no such tracer available. The three candidates [18F]1, [18F]2a and [18F]2b were chosen for in vitro and in vivo characterization as radioligands suitable for selective PET imaging of the D3 receptor. Their evaluation included the analysis of radiometabolites and the assessment of non-specific binding by in vitro rat brain autoradiography. While [18F]1 and [18F]2a revealed high non-specific uptake in in vitro rat brain autoradiography, the D3 receptor density was successfully determined on rat brain sections (n = 4) with the candidate [18F]2b offering a Bmax of 20.38 ± 2.67 pmol/g for the islands of Calleja, 19.54 ± 1.85 pmol/g for the nucleus accumbens and 16.58 ± 1.63 pmol/g for the caudate putamen. In PET imaging studies, the carboxamide 1 revealed low signal/background ratios in the rat brain and relatively low uptake in the pituitary gland, while the azocarboxamides [18F]2a and [18F]2b showed binding that was blockable by the D3 receptor ligand BP897 in the ventricular system and the pituitary gland in PET imaging studies in living rats.
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Affiliation(s)
- Natascha Nebel
- Molecular Imaging and Radiochemistry, Department of Nuclear Medicine, Friedrich Alexander University (FAU), Erlangen 91054, Germany.
| | - Simone Maschauer
- Molecular Imaging and Radiochemistry, Department of Nuclear Medicine, Friedrich Alexander University (FAU), Erlangen 91054, Germany.
| | - Torsten Kuwert
- Molecular Imaging and Radiochemistry, Department of Nuclear Medicine, Friedrich Alexander University (FAU), Erlangen 91054, Germany.
| | - Carsten Hocke
- Molecular Imaging and Radiochemistry, Department of Nuclear Medicine, Friedrich Alexander University (FAU), Erlangen 91054, Germany.
| | - Olaf Prante
- Molecular Imaging and Radiochemistry, Department of Nuclear Medicine, Friedrich Alexander University (FAU), Erlangen 91054, Germany.
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Maschauer S, Haller A, Riss PJ, Kuwert T, Prante O, Cumming P. Specific binding of [(18)F]fluoroethyl-harmol to monoamine oxidase A in rat brain cryostat sections, and compartmental analysis of binding in living brain. J Neurochem 2015; 135:908-17. [PMID: 26386360 DOI: 10.1111/jnc.13370] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2015] [Revised: 09/08/2015] [Accepted: 09/10/2015] [Indexed: 11/28/2022]
Abstract
We investigated [(18)F]fluoroethyl-harmol ([(18)F]FEH) as a reversible and selective ligand for positron emission tomography (PET) studies of monoamine oxidase A (MAO-A). Binding of [(18)F]FEH in rat brain cryostat sections indicated high affinity (KD = 3 nM), and density (Bmax; 600 pmol/g). The plasma free fraction was 45%, and untransformed parent constituted only 13% of plasma radioactivity at 10 min after injection. Compartmental analysis of PET recordings in pargyline-treated rats showed high permeability to brain (K1; 0.32 mL/g/min) and slow washout (k2; 0.024/min), resulting in a uniformly high equilibrium distribution volume (VD; 20 mL/g). Using this VD to estimate unbound ligand in brain of untreated rats, the binding potential ranged from 4.2 in cerebellum to 7.2 in thalamus. We also calculated maps of rats receiving [(18)F]FEH at a range of specific activities, and then estimated saturation binding parameters in the living brain. In thalamus, striatum and frontal cortex KD was globally close to 300 nM and Bmax was close to 1600 pmol/g; the 100-fold discrepancy in affinity suggests a very low free fraction for [(18)F]FEH in the living brain. Based on a synthesis of findings, we calculate the endogenous dopamine concentration to be 0.4 μM in the striatal compartment containing MAO-A, thus unlikely to exert competition against [(18)F]FEH binding in vivo. In summary, [(18)F]FEH has good properties for the detection of MAO-A in the rat brain by PET, and may present logistic advantages for clinical research at centers lacking a medical cyclotron. We made a compartmental analysis of [(18)F]fluoroethylharmol ([(18)F]FEH) binding to monoamine oxidase A (MAO-A) in living rat brain and estimated the saturation binding parameters from the binding potential (BPND). The Bmax was of comparable magnitude to that in vitro, but with apparent affinity (300 nM), it was 100-fold lower in vivo. PET imaging with [(18) F]FEH is well suited for quantitation of MAO-A in living brain.
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Affiliation(s)
- Simone Maschauer
- Laboratory of Molecular Imaging and Radiochemistry, Department of Nuclear Medicine, Friedrich Alexander University, Erlangen, Germany
| | - Adelina Haller
- Laboratory of Molecular Imaging and Radiochemistry, Department of Nuclear Medicine, Friedrich Alexander University, Erlangen, Germany
| | - Patrick J Riss
- Department of Chemistry, Universitetet i Oslo & Norsk Medisinisk Syklotronsenter AS, Oslo, Norway
| | - Torsten Kuwert
- Laboratory of Molecular Imaging and Radiochemistry, Department of Nuclear Medicine, Friedrich Alexander University, Erlangen, Germany
| | - Olaf Prante
- Laboratory of Molecular Imaging and Radiochemistry, Department of Nuclear Medicine, Friedrich Alexander University, Erlangen, Germany
| | - Paul Cumming
- Department of Neuroscience and Pharmacology, Copenhagen University, Copenhagen, Denmark.,Department of Neuropsychiatry and Psychosomatic Medicine, OUS-Rikshospitalet, Oslo, Norway
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Geisler S, Beindorff N, Cremer M, Hoffmann K, Brenner W, Cumming P, Meyer PT, Langen KJ, Fuchs E, Buchert R. Characterization of [123I]FP-CIT binding to the dopamine transporter in the striatum of tree shrews by quantitativein vitroautoradiography. Synapse 2015; 69:497-504. [DOI: 10.1002/syn.21838] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2015] [Revised: 06/22/2015] [Accepted: 06/25/2015] [Indexed: 11/09/2022]
Affiliation(s)
- Stefanie Geisler
- Forschungszentrum Jülich GmbH - Institute of Neuroscience and Medicine; Jülich Germany
| | - Nicola Beindorff
- Department of Nuclear Medicine; Charité - Universitätsmedizin Berlin; Berlin Germany
| | - Markus Cremer
- Forschungszentrum Jülich GmbH - Institute of Neuroscience and Medicine; Jülich Germany
| | | | - Winfried Brenner
- Department of Nuclear Medicine; Charité - Universitätsmedizin Berlin; Berlin Germany
| | - Paul Cumming
- Department of Nuclear Medicine; Friedrich-Alexander University; Erlangen/Nürnberg Germany
- Department of Neuroscience and Pharmacology; University of Copenhagen; Denmark
| | - Philipp T. Meyer
- Department of Nuclear Medicine; University of Freiburg; Freiburg Germany
| | - Karl-Josef Langen
- Forschungszentrum Jülich GmbH - Institute of Neuroscience and Medicine; Jülich Germany
- Department of Nuclear Medicine; University of Aachen; Aachen Germany
| | - Eberhard Fuchs
- German Primate Center; Göttingen Germany
- Department of Neurology; University Medical Center, Georg-August-University Göttingen; Göttingen Germany
| | - Ralph Buchert
- Department of Nuclear Medicine; Charité - Universitätsmedizin Berlin; Berlin Germany
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Perturbed Development of Striatal Dopamine Transporters in Fatty Versus Lean Zucker Rats: a Follow-up Small Animal PET Study. Mol Imaging Biol 2014; 17:521-8. [DOI: 10.1007/s11307-014-0811-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2014] [Revised: 10/31/2014] [Accepted: 11/24/2014] [Indexed: 01/09/2023]
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