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Ozolmez N, Silindir-Gunay M, Volkan-Salanci B. An overview: Radiotracers and nano-radiopharmaceuticals for diagnosis of Parkinson's disease. Appl Radiat Isot 2024; 203:111110. [PMID: 37989065 DOI: 10.1016/j.apradiso.2023.111110] [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: 07/25/2023] [Revised: 11/09/2023] [Accepted: 11/10/2023] [Indexed: 11/23/2023]
Abstract
Parkinson's disease (PD) is a widespread progressive neurodegenerative disease. Clinical diagnosis approaches are insufficient to provide an early and accurate diagnosis before a substantial of loss of dopaminergic neurons. PET and SPECT can be used for accurate and early diagnosis of PD by using target-specific radiotracers. Additionally, the importance of BBB penetrating targeted nanosystems has increased in recent years. This article reviews targeted radiopharmaceuticals used in clinics and novel nanocarriers for research purposes of PD imaging.
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Affiliation(s)
- Nur Ozolmez
- Hacettepe University, Faculty of Pharmacy, Department of Radiopharmacy, Ankara, Turkey.
| | - Mine Silindir-Gunay
- Hacettepe University, Faculty of Pharmacy, Department of Radiopharmacy, Ankara, Turkey.
| | - Bilge Volkan-Salanci
- Hacettepe University, Faculty of Medicine, Department of Nuclear Medicine, Ankara, Turkey.
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Zhao R, Zha Z, Yao X, Ploessl K, Choi SR, Liu F, Zhu L, Kung HF. VMAT2 imaging agent, D6-[ 18F]FP-(+)-DTBZ: Improved radiosynthesis, purification by solid-phase extraction and characterization. Nucl Med Biol 2019; 72-73:26-35. [PMID: 31330409 DOI: 10.1016/j.nucmedbio.2019.07.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Revised: 06/06/2019] [Accepted: 07/06/2019] [Indexed: 02/06/2023]
Abstract
OBJECTIVES Recently, a deuterated tracer, D6-[18F]FP-(+)-DTBZ, 9-O-hexadeutero-3-[18F]fluoropropoxyl-(+)-dihydrotetrabenazine ([18F]9), targeting vesicular monoamine transporter 2 (VMAT2) in the central nervous system, was reported as a useful imaging agent for the diagnosis of Parkinson's disease (PD). The production of [18F]9 was optimized and simplified by using solid-phase extraction (SPE) purification. METHODS Three major nonradioactive impurities were synthesized and characterized. The preparation of [18F]9 was optimized by using different labeling conditions, and an SPE purification method was evaluated. The influence of chemical impurities in the final dose of [18F]9 was assessed by an in vitro binding assay, an assay of the in vivo biodistribution in mice, and ex vivo and in vitro autoradiography of brain sections. RESULTS Optimized fluorination conditions for [18F]9 were found - heating at 130 °C for 10 min in DMSO, and a high radiochemical yield and three major chemical impurities were observed. An SPE method involving a Sep-Pak® tC18 Plus Light cartridge with a two-step elution process was successfully implemented. This process gave a good radiochemical yield (38.7 ± 10.5%, decay corrected; radiochemical purity >99%) and low chemical impurities. An in vivo biodistribution study and autoradiography of brain sections showed that there was no significant difference between HPLC-purified and SPE-purified [18F]9. CONCLUSION A VMAT2 targeting imaging agent, D6-[18F]FP-(+)-DTBZ, [18F]9, was prepared by optimized labeling conditions and an easy SPE purification. This method offers a short preparation time and operational simplicity. In conjunction with PET imaging, this new VMAT2 agent might be a useful clinical tool for diagnosing PD.
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Affiliation(s)
- Ruiyue Zhao
- College of Chemistry, Beijing Normal University, Beijing 100875, PR China; Department of Radiology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Zhihao Zha
- Department of Radiology, University of Pennsylvania, Philadelphia, PA 19104, USA; Five Eleven Pharma Inc., Philadelphia, PA 19104, USA
| | - Xinyue Yao
- College of Chemistry, Beijing Normal University, Beijing 100875, PR China; Department of Radiology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Karl Ploessl
- Five Eleven Pharma Inc., Philadelphia, PA 19104, USA
| | - Seok Rye Choi
- Five Eleven Pharma Inc., Philadelphia, PA 19104, USA
| | - Futao Liu
- College of Chemistry, Beijing Normal University, Beijing 100875, PR China
| | - Lin Zhu
- College of Chemistry, Beijing Normal University, Beijing 100875, PR China
| | - Hank F Kung
- Department of Radiology, University of Pennsylvania, Philadelphia, PA 19104, USA; Five Eleven Pharma Inc., Philadelphia, PA 19104, USA.
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Cline GW, Naganawa M, Chen L, Chidsey K, Carvajal-Gonzalez S, Pawlak S, Rossulek M, Zhang Y, Bini J, McCarthy TJ, Carson RE, Calle RA. Decreased VMAT2 in the pancreas of humans with type 2 diabetes mellitus measured in vivo by PET imaging. Diabetologia 2018; 61:2598-2607. [PMID: 29721633 DOI: 10.1007/s00125-018-4624-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Accepted: 03/29/2018] [Indexed: 12/14/2022]
Abstract
AIMS/HYPOTHESIS The progressive loss of beta cell function is part of the natural history of type 2 diabetes. Autopsy studies suggest that this is, in part, due to loss of beta cell mass (BCM), but this has not been confirmed in vivo. Non-invasive methods to quantify BCM may contribute to a better understanding of type 2 diabetes pathophysiology and the development of therapeutic strategies. In humans, the localisation of vesicular monoamine transporter type 2 (VMAT2) in beta cells and pancreatic polypeptide cells, with minimal expression in other exocrine or endocrine pancreatic cells, has led to its development as a measure of BCM. We used the VMAT2 tracer [18F]fluoropropyl-(+)-dihydrotetrabenazine to quantify BCM in humans with impaired glucose tolerance (prediabetes) or type 2 diabetes, and in healthy obese volunteers (HOV). METHODS Dynamic positron emission tomography (PET) data were obtained for 4 h with metabolite-corrected arterial blood measurement in 16 HOV, five prediabetic and 17 type 2 diabetic participants. Eleven participants (six HOV and five with type 2 diabetes) underwent two abdominal PET/computed tomography (CT) scans for the assessment of test-retest variability. Standardised uptake value ratio (SUVR) was calculated in pancreatic subregions (head, body and tail), with the spleen as a reference region to determine non-specific tracer uptake at 3-4 h. The outcome measure SUVR minus 1 (SUVR-1) accounts for non-specific tracer uptake. Functional beta cell capacity was assessed by C-peptide release following standard (arginine stimulus test [AST]) and acute insulin response to the glucose-enhanced AST (AIRargMAX). Pearson correlation analysis was performed between the binding variables and the C-peptide AUC post-AST and post-AIRargMAX. RESULTS Absolute test-retest variability (aTRV) was ≤15% for all regions. Variability and overlap of SUVR-1 was measured in all groups; HOV and participants with prediabetes and with type 2 diabetes. SUVR-1 showed significant positive correlations with AIRargMAX (all groups) in all pancreas subregions (whole pancreas p = 0.009 and pancreas head p = 0.009; body p = 0.019 and tail p = 0.023). SUVR-1 inversely correlated with HbA1c (all groups) in the whole pancreas (p = 0.033) and pancreas head (p = 0.008). SUVR-1 also inversely correlated with years since diagnosis of type 2 diabetes in the pancreas head (p = 0.049) and pancreas tail (p = 0.035). CONCLUSIONS/INTERPRETATION The observed correlations of VMAT2 density in the pancreas and pancreas regions with years since diagnosis of type 2 diabetes, glycaemic control and beta cell function suggest that loss of BCM contributes to deficient insulin secretion in humans with type 2 diabetes.
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Affiliation(s)
- Gary W Cline
- Yale University, 801 Howard Avenue, PO Box 208048, New Haven, CT, 06520, USA.
| | - Mika Naganawa
- Yale University, 801 Howard Avenue, PO Box 208048, New Haven, CT, 06520, USA
| | | | | | | | | | | | | | - Jason Bini
- Yale University, 801 Howard Avenue, PO Box 208048, New Haven, CT, 06520, USA
| | | | - Richard E Carson
- Yale University, 801 Howard Avenue, PO Box 208048, New Haven, CT, 06520, USA
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Liu F, Choi SR, Zha Z, Ploessl K, Zhu L, Kung HF. Deuterated 18F-9-O-hexadeutero-3-fluoropropoxyl-(+)-dihydrotetrabenazine (D6-FP-(+)-DTBZ): A vesicular monoamine transporter 2 (VMAT2) imaging agent. Nucl Med Biol 2017; 57:42-49. [PMID: 29306111 DOI: 10.1016/j.nucmedbio.2017.11.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Revised: 11/21/2017] [Accepted: 11/28/2017] [Indexed: 11/19/2022]
Abstract
INTRODUCTION Vesicular monoamine transporters 2 (VMAT2) in the brain serve as transporter for packaging monoamine in vesicles for normal CNS neurotransmission. Several VMAT2 imaging agents, [11C]-(+)-DTBZ, dihydrotetrabenazine and [18F]FP-(+)-DTBZ (9-O-fluoropropyl-(+)-dihydro tetrabenazine, a.k.a. [18F]AV-133), are useful for studying the changes in brain function related to monoamine transmission by in vivo imaging. Deuterated analogs have been reported targeting VMAT2 binding sites. METHODS A novel deuterated [18F]9-O-hexaduterofluoropropyl-(+)-dihydrotetrabenazine, [18F]D6-FP-(+)-DTBZ, [18F]1, was prepared as a VMAT2 imaging agent. This 18F agent which targeted VMAT2 was evaluated by in vitro binding, in vivo biodistribution and microPET imaging studies in rodents. RESULTS The one step radiolabeling reaction led to the desired [18F]D6-FP-(+)-DTBZ, [18F]1, which showed excellent binding affinity to VMAT2 (Ki=0.32±0.07nM) comparable to that of FP-(+)-DTBZ (Ki=0.33±0.02nM) using [18F]FP-(+)-DTBZ and rat striatum membrane homogenates. In vivo biodistribution in normal rats showed that 1, exhibited excellent brain uptake and comparable high ratio of striatum to cerebellum (target/background) ratio at 1h after injection (ratio of 6.05±0.43 vs 5.66±0.72 for [18F]FP-(+)-DTBZ vs [18F]1, respectively). MicroPET imaging studies in rats further confirm that the striatum with high VMAT2 concentration was clearly delineated in normal rat brain after iv injection of [18F]1. We observed minor changes of metabolism in rat plasma between these two agents; however, the changes showed little effect on regional brain uptake and retention. CONCLUSIONS The results reported here lend support for using [18F]D6-FP-(+)-DTBZ, [18F]1, as in vivo PET imaging agent for VMAT2 binding in the brain.
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Affiliation(s)
- Futao Liu
- Key Laboratory of Radiopharmaceuticals, Beijing Normal University, Ministry of Education, Beijing 100875, PR China; Department of Radiology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Seok Rye Choi
- Department of Radiology, University of Pennsylvania, Philadelphia, PA 19104, USA; Five Eleven Pharma Inc., Philadelphia, PA 19104, USA
| | - Zhihao Zha
- Department of Radiology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Karl Ploessl
- Department of Radiology, University of Pennsylvania, Philadelphia, PA 19104, USA; Five Eleven Pharma Inc., Philadelphia, PA 19104, USA
| | - Lin Zhu
- Key Laboratory of Radiopharmaceuticals, Beijing Normal University, Ministry of Education, Beijing 100875, PR China; Department of Radiology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Hank F Kung
- Department of Radiology, University of Pennsylvania, Philadelphia, PA 19104, USA; Five Eleven Pharma Inc., Philadelphia, PA 19104, USA.
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Structural requirement of C11b chirality of tetrabenazine analogs as VMAT2 imaging ligands: synthesis and in vivo evaluation. J Radioanal Nucl Chem 2017. [DOI: 10.1007/s10967-017-5333-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Kilbourn MR. PET studies in non-human primates: Choosing drug doses. Nucl Med Biol 2017; 47:1-3. [DOI: 10.1016/j.nucmedbio.2016.12.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Accepted: 12/05/2016] [Indexed: 11/29/2022]
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Quantitative analysis of the therapeutic effect of magnolol on MPTP-induced mouse model of Parkinson's disease using in vivo 18F-9-fluoropropyl-(+)-dihydrotetrabenazine PET imaging. PLoS One 2017; 12:e0173503. [PMID: 28257461 PMCID: PMC5336287 DOI: 10.1371/journal.pone.0173503] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Accepted: 02/21/2017] [Indexed: 02/04/2023] Open
Abstract
18F-9-Fluoropropyl-(+)-dihydrotetrabenazine [18F-FP-(+)-DTBZ] positron emission tomography (PET) has been shown to detect dopaminergic neuron loss associated with Parkinson’s disease (PD) in human and neurotoxin-induced animal models. A polyphenol compound, magnolol, was recently proposed as having a potentially restorative effect in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)- or 6-hydroxydopamine-treated animal models. In this study, 18F-FP-(+)-DTBZ PET was used to determine the therapeutic efficacy of magnolol in an MPTP–PD mouse model that was prepared by giving an intraperitoneally (i.p.) daily dose of 25 mg/kg MPTP to male C57BL/6 mice for 5 consecutive days. Twenty-minute static 18F-FP-(+)-DTBZ PET scans were performed before MPTP treatment and 5 days after the termination of MPTP treatment to set up the baseline control. Half of the MPTP-treated mice then received a daily dose of magnolol (10 mg/kg dissolved in corn oil, i.p.) for 6 days. 18F-FP-(+)-DTBZ PET imaging was performed the day after the final treatment. All 18F-FP-(+)-DTBZ PET images were analysed and the specific uptake ratio (SUr) was calculated. Ex vivo autoradiography (ARG) and corresponding immunohistochemistry (IHC) studies were conducted to confirm the distribution of dopaminergic terminals in the striatum. The striatal SUr ratios of 18F-FP-(+)-DTBZ PET images for the Sham, the MPTP, and the MPTP + Magnolol-treated groups were 1.25 ± 0.05, 0.75 ± 0.06, and 1.00 ± 0.11, respectively (n = 4 for each group). The ex vivo 18F-FP-(+)-DTBZ ARG and IHC results correlated favourably with the PET imaging results. 18F-FP-(+)-DTBZ PET imaging suggested that magnolol post-treatment may reverse the neuronal damage in the MPTP-lesioned PD mice. In vivo imaging of the striatal vesicular monoamine transporter type 2 (VMAT2) distribution using 18F-FP-(+)-DTBZ animal PET is a useful method to evaluate the efficacy of therapeutic drugs i.e., magnolol, for the management of PD.
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Wu X, Zhou X, Zhang S, Zhang Y, Deng A, Han J, Zhu L, Kung HF, Qiao J. Brain uptake of a non-radioactive pseudo-carrier and its effect on the biodistribution of [(18)F]AV-133 in mouse brain. Nucl Med Biol 2015; 42:630-6. [PMID: 25910857 DOI: 10.1016/j.nucmedbio.2015.03.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Revised: 03/28/2015] [Accepted: 03/30/2015] [Indexed: 10/23/2022]
Abstract
INTRODUCTION 9-[(18)F]Fluoropropyl-(+)-dihydrotetrabenazine ([(18)F]AV-133) is a new PET imaging agent targeting vesicular monoamine transporter type II (VMAT2). To shorten the preparation of [(18)F]AV-133 and to make it more widely available, a simple and rapid purification method using solid-phase extraction (SPE) instead of high-pressure liquid chromatography (HPLC) was developed. The SPE method produced doses containing the non-radioactive pseudo-carrier 9-hydroxypropyl-(+)-dihydrotetrabenazine (AV-149). The objectives of this study were to evaluate the brain uptake of AV-149 by UPLC-MS/MS and its effect on the biodistribution of [(18)F]AV-133 in the brains of mice. METHODS The mice were injected with a bolus including [(18)F]AV-133 and different doses of AV-149. Brain tissue and blood samples were harvested. The effect of different amounts of AV-149 on [(18)F]AV-133 was evaluated by quantifying the brain distribution of radiolabelled tracer [(18)F]AV-133. The concentrations of AV-149 in the brain and plasma were analyzed using a UPLC-MS/MS method. RESULTS The concentrations of AV-149 in the brain and plasma exhibited a good linear relationship with the doses. The receptor occupancy curve was fit, and the calculated ED50 value was 8.165mg/kg. The brain biodistribution and regional selectivity of [(18)F]AV-133 had no obvious differences at AV-149 doses lower than 0.1mg/kg. With increasing doses of AV-149, the brain biodistribution of [(18)F]AV-133 changed significantly. CONCLUSION The results are important to further support that the improved radiolabelling procedure of [(18)F]AV-133 using an SPE method may be suitable for routine clinical application.
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Affiliation(s)
- Xianying Wu
- Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing, China
| | - Xue Zhou
- Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing, China
| | - Shuxian Zhang
- Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing, China
| | - Yan Zhang
- Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing, China
| | - Aifang Deng
- Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing, China
| | - Jie Han
- Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing, China
| | - Lin Zhu
- Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing, China; Center of Parkinson's Disease, Beijing Institute for Brain Disorders, Beijing, China.
| | - Hank F Kung
- Center of Parkinson's Disease, Beijing Institute for Brain Disorders, Beijing, China
| | - Jinping Qiao
- Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing, China.
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Kunigami M, Hara S. Synthesis of fluoromethyl ethers and fluoromethyl esters by the reaction of the corresponding methylthiomethyl ethers and methylthiomethyl esters with IF5-pyridine-HF. J Fluor Chem 2014. [DOI: 10.1016/j.jfluchem.2014.05.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Kilbourn MR. PET radioligands for the vesicular transporters for monoamines and acetylcholine. J Labelled Comp Radiopharm 2014; 56:167-71. [PMID: 24285322 DOI: 10.1002/jlcr.2998] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2012] [Revised: 06/15/2012] [Accepted: 11/06/2012] [Indexed: 11/09/2022]
Abstract
The vesicular transporters for the monoamine and acetylcholine have been successfully targeted for the development of radioligands for human brain imaging. The vesicular monoamine transporter type 2 ligands are based on the structure of tetrabenazine, a known clinically used drug. In contrast, the radioligands for vesicular acetylcholine transporter are based on vesamicol, a toxic xenobiotic. The similarities and differences in the development of these two classes of radioligands are discussed.
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Affiliation(s)
- Michael R Kilbourn
- Division of Nuclear Medicine, Department of Radiology, University of Michigan Medical School, Ann Arbor, MI, USA
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Deng A, Wu X, Zhou X, Zhang Y, Yin W, Qiao J, Zhu L. Mapping the target localization and biodistribution of non-radiolabeled VMAT2 ligands in rat brain. AAPS JOURNAL 2014; 16:592-9. [PMID: 24706374 DOI: 10.1208/s12248-014-9584-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2013] [Accepted: 02/21/2014] [Indexed: 01/02/2023]
Abstract
Imaging targeting vesicular monoamine transporter (VMAT2) alterations is a sensitive tool for early diagnosis of Parkinson's disease. Our group has reported several novel 2-amino-DTBZ derivatives as potential VMAT2 imaging agents. The objective of this paper is to develop a non-radiolabeled methodology to screen the candidate compounds for accelerating the drug discovery process. 9-[(18)F]fluoropropyl-(+)-dihydrotetrabenazine ([(18)F]AV-133) is a PET imaging agent targeting VMAT2 binding sites in the brain. Nonradioactive AV-133 was injected (iv) into rats, at the end of the allotted time, the animals were killed and six regions of brain and plasma from each animal were processed for quantitative measurement of AV-133 by LC-MS/MS. These data were converted to the percentage injected dose per gram tissue weight (%ID/g tissue) and the brain target tissue to background ratios to allow direct comparison with data obtained by gamma counting of the injected radioactive [(18)F]AV-133. The %ID/g and the brain target tissue to background ratios calculated using the LC-MS/MS method were highly correlated to the values obtained by standard radioactivity measurements of [(18)F]AV-133. The pattern of AV-133 in rat brain was consistent with the known distribution of VMAT2. The concordance indicated that high-sensitivity LC-MS/MS is an indispensable tool in evaluating the quantity of administered chemical in tissue as part of the development of new molecular imaging probes. Furthermore, several novel 2-amino-DTBZ derivatives were detected using this methodology, and their biodistribution data in rat brain were obtained. The information about target engagements of candidates was provided.
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Affiliation(s)
- Aifang Deng
- Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing, 100875, People's Republic of China
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Li X, Chen Z, Tang J, Liu C, Zou P, Huang H, Tan C, Yu H. Synthesis and biological evaluation of 10-(11) C-dihydrotetrabenazine as a vesicular monoamine transporter 2 radioligand. Arch Pharm (Weinheim) 2014; 347:313-9. [PMID: 24497196 DOI: 10.1002/ardp.201300307] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2013] [Revised: 11/14/2013] [Accepted: 11/15/2013] [Indexed: 11/06/2022]
Abstract
In this study, we synthesized a new carbon-11-labeled radiotracer, 10-(11) C-dihydrotetrabenazine (10-(11) C-DTBZ), and evaluated its potential as a vesicular monoamine transporter 2 (VMAT2) radioligand. The radiolabeled precursor 10-O-desmethyl-dihydrotetrabenazine (10-O-desmethyl-DTBZ) was prepared with a six-step reaction using 3-methoxy-4-benzyloxybenzaldehyde as starting material. 10-(11) C-DTBZ was synthesized by heating 1.0 mg of 10-hydroxy precursor and (11) C-methyl iodide in the presence of 0.3 mL of dimethyl sulfoxide and 4.0 µL of 3 N KOH at room temperature for 3 min. After purification by solid phase extraction using an alumina Sep-Pak cartridge, the final 10-(11) C-DTBZ product was obtained with a radiochemical purity of >99% and an uncorrected radiochemical yield of 18-26% (end of bombardment (EOB), n = 6). The overall synthesis time was approximately 20 min from the EOB to release of the product for quality control. Using small-animal positron emission tomography (microPET), the striatum of normal rats was found to exhibit symmetrical labeling (STR /STL = 0.98 ± 0.05, n = 3) and the highest uptake of radioactivity (striatum/cerebellum, ST/CB = 2.89 ± 0.31 at 30-60 min, n = 3). In contrast, rats with 6-hydroxydopamine unilateral lesions yielded asymmetrical striatal images with a higher 10-(11) C-DTBZ concentration on the unlesioned side (STunlesioned /CB = 2.53 ± 0.18, at 30-60 min, n = 3) compared with the lesioned side (STlesioned /CB = 1.26 ± 0.10, n = 3). These results suggest that 10-(11) C-DTBZ may represent a promising PET radiotracer for imaging VMAT2.
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Affiliation(s)
- Xiaomin Li
- Key Laboratory of Nuclear Medicine, Ministry of Health, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi, P. R. China
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Liu Y, Yue F, Tang R, Tao G, Pan X, Zhu L, Kung HF, Chan P. Progressive loss of striatal dopamine terminals in MPTP-induced acute parkinsonism in cynomolgus monkeys using vesicular monoamine transporter type 2 PET imaging ([(18)F]AV-133). Neurosci Bull 2013; 30:409-16. [PMID: 24061965 DOI: 10.1007/s12264-013-1374-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2013] [Accepted: 07/01/2013] [Indexed: 11/28/2022] Open
Abstract
The 1-methyl-4-phenyl-1,2,3,4-tetrahydropyridine (MPTP)-induced parkinsonism model, particularly in non-human primates, remains the gold-standard for studying the pathogenesis and assessing novel therapies for Parkinson's disease. However, whether the loss of dopaminergic neurons in this model is progressive remains controversial, mostly due to the lack of objective in vivo assessment of changes in the integrity of these neurons. In the present study, parkinsonism was induced in cynomolgus monkeys by intravenous administration of MPTP (0.2 mg/kg) for 15 days; stable parkinsonism developed over 90 days, when the symptoms were stable. Noninvasive positron emission tomographic neuroimaging of vesicular monoamine transporter 2 with 9-[(18)F] fluoropropyl-(+)-dihydrotetrabenazine ([(18)F]AV-133) was used before, and 15 and 90 days after the beginning of acute MPTP treatment. The imaging showed evident progressive loss of striatal uptake of [(18)F]AV-133. The dopaminergic denervation severity had a significant linear correlation with the clinical rating scores and the bradykinesia subscores. These findings demonstrated that [(18)F]AV-133 PET imaging is a useful tool to noninvasively evaluate the evolution of monoaminergic terminal loss in a monkey model of MPTP-induced parkinsonism.
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Affiliation(s)
- Yajing Liu
- Department of Neurobiology, Xuanwu Hospital of Capital Medical University, Beijing, 100053, China
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14
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Park C, Lee BS, Chi DY. High efficiency synthesis of F-18 fluoromethyl ethers: an attractive alternative for C-11 methyl groups in positron emission tomography radiopharmaceuticals. Org Lett 2013; 15:4346-9. [PMID: 23930998 DOI: 10.1021/ol401792n] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
A rapid and efficient method for the synthesis of O-fluoromethyl aliphatic and aromatic ethers is presented. This method is so mild that it can be used for the preparation of positron emission tomography (PET) radiopharmaceuticals bearing O-[(18)F]fluoromethyl groups.
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Affiliation(s)
- Chansoo Park
- Department of Chemistry, Sogang University, 35 Baekbeomro Mapogu, Seoul 121-742, Korea
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Schäfer MKH, Hartwig NR, Kalmbach N, Klietz M, Anlauf M, Eiden LE, Weihe E. Species-specific vesicular monoamine transporter 2 (VMAT2) expression in mammalian pancreatic beta cells: implications for optimising radioligand-based human beta cell mass (BCM) imaging in animal models. Diabetologia 2013; 56:1047-56. [PMID: 23404442 PMCID: PMC3955760 DOI: 10.1007/s00125-013-2847-7] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/05/2012] [Accepted: 01/11/2013] [Indexed: 12/15/2022]
Abstract
AIMS/HYPOTHESIS Imaging of beta cell mass (BCM) is a major challenge in diabetes research. The vesicular monoamine transporter 2 (VMAT2) is abundantly expressed in human beta cells. Radiolabelled analogues of tetrabenazine (TBZ; a low-molecular-weight, cell-permeant VMAT2-selective ligand) have been employed for pancreatic islet imaging in humans. Since reports on TBZ-based VMAT2 imaging in rodent pancreas have been fraught with confusion, we compared VMAT2 gene expression patterns in the mouse, rat, pig and human pancreas, to identify appropriate animal models with which to further validate and optimise TBZ imaging in humans. METHODS We used a panel of highly sensitive VMAT2 antibodies developed against equivalently antigenic regions of the transporter from each species in combination with immunostaining for insulin and species-specific in situ hybridisation probes. Individual pancreatic islets were obtained by laser-capture microdissection and subjected to analysis of mRNA expression of VMAT2. RESULTS The VMAT2 protein was not expressed in beta cells in the adult pancreas of common mouse or rat laboratory strains, in contrast to its expression in beta cells (but not other pancreatic endocrine cell types) in the pancreas of pigs and humans. VMAT2- and tyrosine hydroxylase co-positive (catecholaminergic) innervation was less abundant in humans than in rodents. VMAT2-positive mast cells were identified in the pancreas of all species. CONCLUSIONS/INTERPRETATION Primates and pigs are suitable models for TBZ imaging of beta cells. Rodents, because of a complete lack of VMAT2 expression in the endocrine pancreas, are a 'null' model for assessing interference with BCM measurements by VMAT2-positive mast cells and sympathetic innervation in the pancreas.
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Affiliation(s)
- M K-H Schäfer
- Department of Molecular Neuroscience, Institute of Anatomy and Cell Biology, Philipps University Marburg, Robert-Koch-Straße 8, 35037 Marburg, Germany.
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liu C, Chen Z, Li X, Tang J, Qin X. (+)-9-Benzyloxy-α-Dihydrotetrabenazine as an Important Intermediate for the VMAT2 Imaging Agents: Absolute Configuration and Chiral Recognition. Chirality 2013; 25:215-23. [DOI: 10.1002/chir.22126] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2012] [Accepted: 09/21/2012] [Indexed: 11/06/2022]
Affiliation(s)
- Chunyi liu
- Key Laboratory of Nuclear Medicine, Ministry of Health, Jiangsu Key Laboratory of Molecular Nuclear Medicine; Jiangsu Institute of Nuclear Medicine; Wuxi; Jiangsu; China; 214063
| | - Zhengping Chen
- Key Laboratory of Nuclear Medicine, Ministry of Health, Jiangsu Key Laboratory of Molecular Nuclear Medicine; Jiangsu Institute of Nuclear Medicine; Wuxi; Jiangsu; China; 214063
| | - Xiaomin Li
- Key Laboratory of Nuclear Medicine, Ministry of Health, Jiangsu Key Laboratory of Molecular Nuclear Medicine; Jiangsu Institute of Nuclear Medicine; Wuxi; Jiangsu; China; 214063
| | - Jie Tang
- Key Laboratory of Nuclear Medicine, Ministry of Health, Jiangsu Key Laboratory of Molecular Nuclear Medicine; Jiangsu Institute of Nuclear Medicine; Wuxi; Jiangsu; China; 214063
| | - Xiaofeng Qin
- Key Laboratory of Nuclear Medicine, Ministry of Health, Jiangsu Key Laboratory of Molecular Nuclear Medicine; Jiangsu Institute of Nuclear Medicine; Wuxi; Jiangsu; China; 214063
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Zhu L, Qiao H, Lieberman BP, Wu J, Liu Y, Pan Z, Ploessl K, Choi SR, Chan P, Kung HF. Imaging of VMAT2 binding sites in the brain by (18)F-AV-133: the effect of a pseudo-carrier. Nucl Med Biol 2012; 39:897-904. [PMID: 22749185 DOI: 10.1016/j.nucmedbio.2012.05.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2012] [Revised: 05/17/2012] [Accepted: 05/21/2012] [Indexed: 11/28/2022]
Abstract
OBJECTIVES Recently, 9-[(18)F]fluoropropyl-(+)-dihydrotetrabenazine ((18)F-AV-133) was reported as a new vesicular monoamine transporter (VMAT2) imaging agent for diagnosis of Parkinson's disease (PD). To shorten the preparation of (18)F-AV-133 and to make it more widely available, we evaluated a simple, rapid purification with a solid-phase extraction method (SPE) using an Oasis HLB cartridge instead of high pressure liquid chromatography (HPLC). The SPE method produced doses containing a pseudo-carrier, 9-hydroxypropyl-(+)-dihydrotetrabenazine (AV-149). METHODS To test the possible side effects of this pseudo-carrier, comparative dynamic PET scans of the brains of normal monkeys (2 each) and uni-laterally 6-OH-dopamine-lesioned PD monkeys (2 each) were performed using (18)F-AV-133 doses prepared by either SPE (containing pseudo-carrier) or HPLC (containing no pseudo-carrier). Autoradiographs of post mortem monkey brain sections were evaluated to confirm the relative (18)F-AV-133 uptake in the PD monkey brains and the effects of the pseudo-carrier on VMAT2 binding. RESULTS The radiochemical purity of the (18)F-AV-133, whether prepared by SPE or by HPLC, was excellent (>99%). PET scans of normal and PD monkey brains showed an expected reduction of VMAT2 in the lesioned areas of the striatum. It was not affected by the presence of the pseudo-carrier, AV-149 (maximally 250 μg/dose). The reduced uptake in the striatum of the lesioned monkey brains was confirmed by autoradiography. Ex vivo inhibition studies of (18)F-AV-133 binding in rat brains, conducted with increasing amounts of AV-149, suggested that at the highest concentration (3.5mg/kg) the VMAT2 binding in the striatum was only moderately blocked (20% reduction). CONCLUSIONS The pseudo-carrier, AV-149, did not affect the (18)F-AV-133/PET imaging of VMAT2 binding sites in normal or uni-laterally lesioned monkey brains. The new streamlined SPE purification method will enable (18)F-AV-133 to be widely available for routine clinical application in determining changes in monoamine neurons for patient with movement disorders or other psychiatric illnesses.
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Affiliation(s)
- Lin Zhu
- Key Laboratory of Radiopharmaceuticals (Beijing Normal University) Ministry of Education, Beijing, China
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Chao KT, Tsao HH, Weng YH, Hsiao IT, Hsieh CJ, Wey SP, Yen TC, Kung MP, Lin KJ. Quantitative analysis of binding sites for 9-fluoropropyl-(+)-dihydrotetrabenazine ([18F]AV-133) in a MPTP-lesioned PD mouse model. Synapse 2012; 66:823-31. [DOI: 10.1002/syn.21572] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2012] [Accepted: 05/08/2012] [Indexed: 02/06/2023]
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Lee KM, Kim JC, Kang P, Lee WK, Eum H, Ha HJ. Chiral aziridine-2-carboxylates: versatile precursors for functionalized tetrahydroisoquinoline (THIQ) containing heterocycles. Tetrahedron 2012. [DOI: 10.1016/j.tet.2011.11.031] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
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Abstract
Advances in imaging have made it possible to detect functional and, increasingly, structural changes in Parkinson's disease. Although imaging is not yet routinely used for diagnosis, such an application is becoming increasingly feasible. Of potentially greater interest, however, is the use of imaging as a biomarker to detect premotor disease and disease progression. Imaging also provides insights into complications of Parkinson's disease and its long-term treatment, and the role of dopamine in the normal brain. Furthermore, these techniques can be applied to animal models, to help validate these models and allow their use in the study of potential disease-modifying therapies.
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Affiliation(s)
- A Jon Stoessl
- Pacific Parkinson's Research Centre, University of British Columbia, Vancouver, BC, Canada.
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21
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Distribution of vesicular monoamine transporter 2 protein in human brain: implications for brain imaging studies. J Cereb Blood Flow Metab 2011; 31:2065-75. [PMID: 21522164 PMCID: PMC3208151 DOI: 10.1038/jcbfm.2011.63] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The choice of reference region in positron emission tomography (PET) human brain imaging of the vesicular monoamine transporter 2 (VMAT2), a marker of striatal dopamine innervation, has been arbitrary, with cerebellar, whole cerebral, frontal, or occipital cortices used. To establish whether levels of VMAT2 are in fact low in these cortical areas, we measured VMAT2 protein distribution by quantitative immunoblotting in autopsied normal human brain (n=6). Four or five species of VMAT2 immunoreactivity (75, 55, 52, 45, 35 kDa) were detected, which were all markedly reduced in intensity in nigrostriatal regions of patients with parkinsonian conditions versus matched controls (n=9 to 10 each). Using the intact VMAT2 immunoreactivity, cerebellar and cerebral neocortices had levels of the transporter >100-fold lower than the VMAT2-rich striatum and with no significant differences among the cortical regions. We conclude that human cerebellar and cerebral cortices contain negligible VMAT2 protein versus the striatum and, in this respect, all satisfy a criterion for a useful reference region for VMAT2 imaging. The slightly lower PET signal for VMAT2 binding in occipital (the currently preferred reference region) versus cerebellar cortex might not therefore be explained by differences in VMAT2 protein itself but possibly by other imaging variables, for example, partial volume effects.
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Zhou X, Qiao J, Yin W, Zhu L, Kung HF. Determination of the penetration of 9-fluoropropyl-(+)-dihydrotetrabenazine across the blood-brain barrier in rats by microdialysis combined with liquid chromatography-tandem mass spectrometry. J Chromatogr B Analyt Technol Biomed Life Sci 2011; 879:3041-6. [PMID: 21937290 DOI: 10.1016/j.jchromb.2011.08.043] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2011] [Revised: 08/16/2011] [Accepted: 08/30/2011] [Indexed: 11/19/2022]
Abstract
To evaluate the penetration of the blood-brain barrier by 9-fluoropropyl-(+)-dihydrotetrabenazine (AV-133), microdialysis probes were implanted simultaneously into rat blood and brain, and a liquid chromatography-tandem mass spectrometric method was developed and validated to monitor the AV-133 concentration in the microdialysates. The chromatographic separation was performed on an XTerra C(18) column (150 mm × 2.1 mm i.d., 5 μm particles) with gradient elution. The mass spectrometer was operated in positive mode using electrospray ionization. The analytes were measured using the multiple-reaction-monitoring mode. The calibration curves were linear over the range of 5.00-1000 ng/mL AV-133, with a coefficient of determination >0.995. The accuracies ranged from 99.5% to 105.0% and the precisions were <10% for AV-133. This method was used to determine the concentrations of AV-133 and its pharmacokinetics in the brains and blood of rats. The blood and brain concentration-time profiles for AV-133 were obtained, and the blood-brain barrier penetration was evaluated.
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Affiliation(s)
- Xue Zhou
- Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, PR China
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Wimalasena K. Vesicular monoamine transporters: structure-function, pharmacology, and medicinal chemistry. Med Res Rev 2011; 31:483-519. [PMID: 20135628 PMCID: PMC3019297 DOI: 10.1002/med.20187] [Citation(s) in RCA: 119] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Vesicular monoamine transporters (VMAT) are responsible for the uptake of cytosolic monoamines into synaptic vesicles in monoaminergic neurons. Two closely related VMATs with distinct pharmacological properties and tissue distributions have been characterized. VMAT1 is preferentially expressed in neuroendocrine cells and VMAT2 is primarily expressed in the CNS. The neurotoxicity and addictive properties of various psychostimulants have been attributed, at least partly, to their interference with VMAT2 functions. The quantitative assessment of the VMAT2 density by PET scanning has been clinically useful for early diagnosis and monitoring of the progression of Parkinson's and Alzheimer's diseases and drug addiction. The classical VMAT2 inhibitor, tetrabenazine, has long been used for the treatment of chorea associated with Huntington's disease in the United Kingdom, Canada, and Australia, and recently approved in the United States. The VMAT2 imaging may also be useful for exploiting the onset of diabetes mellitus, as VMAT2 is also expressed in the β-cells of the pancreas. VMAT1 gene SLC18A1 is a locus with strong evidence of linkage with schizophrenia and, thus, the polymorphic forms of the VMAT1 gene may confer susceptibility to schizophrenia. This review summarizes the current understanding of the structure-function relationships of VMAT2, and the role of VMAT2 on addiction and psychostimulant-induced neurotoxicity, and the therapeutic and diagnostic applications of specific VMAT2 ligands. The evidence for the linkage of VMAT1 gene with schizophrenia and bipolar disorder I is also discussed.
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Zheng P, Lieberman BP, Choi SR, Plöessl K, Kung HF. Synthesis and biological evaluation of 3-alkyl-dihydrotetrabenazine derivatives as vesicular monoamine transporter-2 (VMAT2) ligands. Bioorg Med Chem Lett 2011; 21:3435-8. [PMID: 21531556 DOI: 10.1016/j.bmcl.2011.03.113] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2011] [Revised: 03/24/2011] [Accepted: 03/29/2011] [Indexed: 11/19/2022]
Abstract
In the search of new probes for in vivo brain imaging of vesicular monoamine transporter type 2 (VMAT2), we have developed an efficient synthesis of a novel series of 3-alkyl-dihydrotetrabenazine (DTBZ) derivatives. The affinity of VMAT2 was evaluated by an in vitro inhibitory binding assay using [(125)I]-iodovinyl-TBZ or [(18)F](+)-FP-DTBZ as radioligands in rat striatal tissue homogenates. New DTBZ derivatives exhibited moderate to good binding affinity to VMAT2. Among these new ligands, compound 4b showed the best affinity for VMAT2 (K(i)=5.98 nM) and may be a useful lead compound for future structure-activity studies.
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Affiliation(s)
- Pinguan Zheng
- Department of Radiology, University of Pennsylvania, Philadelphia, PA 19104, USA
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Fluorine-18 radiopharmaceuticals beyond [18F]FDG for use in oncology and neurosciences. Nucl Med Biol 2011; 37:727-40. [PMID: 20870148 DOI: 10.1016/j.nucmedbio.2010.04.185] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2010] [Revised: 04/23/2010] [Accepted: 04/27/2010] [Indexed: 11/21/2022]
Abstract
Positron emission tomography (PET) is a rapidly expanding clinical modality worldwide thanks to the availability of compact medical cyclotrons and automated chemistry for the production of radiopharmaceuticals. There is an armamentarium of fluorine-18 ((18)F) tracers that can be used for PET studies in the fields of oncology and neurosciences. However, most of the (18)F-tracers other than 2-deoxy-2-[18F]fluoro-D-glucose (FDG) are in less than optimum human use and there is considerable scope to bring potentially useful (18)F-tracers to clinical investigation stage. The International Atomic Energy Agency (IAEA) convened a consultants' group meeting to review the current status of (18)F-based radiotracers and to suggest means for accelerating their use for diagnostic applications. The consultants reviewed the developments including the synthetic approaches for the preparation of (18)F-tracers for oncology and neurosciences. A selection of three groups of (18)F-tracers that are useful either in oncology or in neurosciences was done based on well-defined criteria such as application, lack of toxicity, availability of precursors and ease of synthesis. Based on the recommendations of the consultants' group meeting, IAEA started a coordinated research project on "Development of (18)F radiopharmaceuticals (beyond [(18)F]FDG) for use in oncology and neurosciences" in which 14 countries are participating in a 3-year collaborative program. The outcomes of the coordinated research project are expected to catalyze the wider application of several more (18)F-radiopharmaceuticals beyond FDG for diagnostic applications in oncology and neurosciences.
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Zhou X, Qiao J, Yin W, Zhu L, Kung HF. Study the effect of a pseudo-carrier on pharmacokinetics of 9-fluoropropyl-(+)-dihydrotetrabenazine in rat plasma by ultra-performance liquid chromatography-tandem mass spectrometry. J Chromatogr B Analyt Technol Biomed Life Sci 2011; 879:505-10. [PMID: 21277842 DOI: 10.1016/j.jchromb.2011.01.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2010] [Revised: 11/21/2010] [Accepted: 01/09/2011] [Indexed: 10/18/2022]
Abstract
To evaluate the effect of a pseudo-carrier (9-hydroxypropyl-(+)-dihydrotetrabenazine, AV-149) on pharmacokinetics of 9-fluoropropyl-(+)-dihydrotetrabenazine (AV-133), an ultra-performance liquid chromatography-tandem mass spectrometric (UPLC-MS/MS) method was developed and validated for the determination of AV-133 and AV-149 in rat plasma. AV-133 and AV-149 were extracted from plasma following protein precipitation. The chromatographic analysis was performed on an ACQUITY UPLC BEH™ C₁₈ column (50 mm x 2.1 mm x 1.7 μm) by a gradient elution. The mass spectrometer was operated in positive mode using electrospray ionization. The analytes were measured using the multiple reaction-monitoring mode (MRM). An external calibration was used, and the calibration curves were linear in the range of 1.00-800 ng/mL for AV-133 and AV-149. The accuracy ranged from 90.8% to 113.2% and the precision ranged from 2.7% to 9.9% for each analyte. The effect of a pseudo-carrier on pharmacokinetics of AV-133 was studied using the presented method.
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Affiliation(s)
- Xue Zhou
- Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, PR China
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27
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Pancreatic beta cell mass PET imaging and quantification with [11C]DTBZ and [18F]FP-(+)-DTBZ in rodent models of diabetes. Mol Imaging Biol 2010; 13:973-84. [PMID: 20824509 DOI: 10.1007/s11307-010-0406-x] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2010] [Accepted: 07/06/2010] [Indexed: 12/15/2022]
Abstract
PURPOSE The aim of this study is to compare the utility of two positron emission tomography (PET) imaging ligands ((+)-[(11)C]dihydrotetrabenazine ([(11)C]DTBZ) and the fluoropropyl analog ([(18)F]FP-(+)-DTBZ)) that target islet β-cell vesicular monoamine transporter type II to measure pancreatic β-cell mass (BCM). PROCEDURES [(11)C]DTBZ or [(18)F]FP-(+)-DTBZ was injected, and serial PET images were acquired in rat models of diabetes (streptozotocin-treated and Zucker diabetic fatty) and β-cell compensation (Zucker fatty). Radiotracer standardized uptake values (SUV) were correlated to pancreas insulin content measured biochemically and histomorphometrically. RESULTS On a group level, a positive correlation of [(11)C]DTBZ pancreatic SUV with pancreas insulin content and BCM was observed. In the STZ diabetic model, both [(18)F]FP-(+)-DTBZ and [(11)C]DTBZ correlated positively with BCM, although only ∼25% of uptake could be attributed to β-cell uptake. [(18)F]FP-(+)-DTBZ displacement studies indicate that there is a substantial fraction of specific binding that is not to pancreatic islet β cells. CONCLUSIONS PET imaging with [(18)F]FP-(+)-DTBZ provides a noninvasive means to quantify insulin-positive BCM and may prove valuable as a diagnostic tool in assessing treatments to maintain or restore BCM.
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Lin KJ, Weng YH, Wey SP, Hsiao IT, Lu CS, Skovronsky D, Chang HP, Kung MP, Yen TC. Whole-Body Biodistribution and Radiation Dosimetry of 18F-FP-(+)-DTBZ (18F-AV-133): A Novel Vesicular Monoamine Transporter 2 Imaging Agent. J Nucl Med 2010; 51:1480-5. [DOI: 10.2967/jnumed.110.078196] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Wang JL, Oya S, Parhi AK, Lieberman BP, Ploessl K, Hou C, Kung HF. In vivo studies of the SERT-selective [18F]FPBM and VMAT2-selective [18F]AV-133 radiotracers in a rat model of Parkinson's disease. Nucl Med Biol 2010; 37:479-86. [PMID: 20447560 DOI: 10.1016/j.nucmedbio.2010.01.006] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2009] [Revised: 01/14/2010] [Accepted: 01/27/2010] [Indexed: 11/26/2022]
Abstract
INTRODUCTION The utility of [(18)F]FPBM [2-(2'-((dimethylamino)methyl)-4'-(3-[(18)F]-fluoropropoxy)phenylthio)benzenamine], a selective serotonin transporter (SERT) tracer, and [(18)F]AV-133 [(+)-2-Hydroxy-3-isobutyl-9-(3-fluoropropoxy)-10-methoxy-1,2,3,4,6,7-hexahydro-11bH-benzo[a]quinolizine], a selective vesicular monoamine transporter 2 (VMAT2) tracer, were tested in the 6-hydroxydopamine (6-OHDA) unilateral lesioned rat model. METHODS Positron emission tomography (PET) imaging of three 6-OHDA unilateral lesioned male Sprague Dawley rats (Rats 1-3) were performed with [(18)F]FPBM and [(18)F]AV-133 to examine whether changes in SERT and VMAT2 binding, respectively, could be detected in the brain. The brains of the three rats were then removed and examined by in vitro autoradiography with [(18)F]FPBM and the dopamine transporter ligand, [(125)I]IPT [N-(3'-[(125)I]-iodopropen-2'-yl)-2-beta-carbomethoxy-3-beta-(4-chloro phenyl) tropane, for confirmation. Biodistribution of [(18)F]FPBM in a separate group of p-chloroamphetamine (PCA) treated rats were also performed. RESULTS PET image analysis showed varying levels of SERT binding reduction (Rat 1=-11%, Rat 2=-4%, Rat 3=-43%; n=2) and a clear and definitive loss of VMAT2 binding (Rat 1=-87%, Rat 2=-72%, and Rat 3=-91%; n=1) in the left striatum when compared to the right (non-lesioned side) striatum. The results from PET imaging were corroborated with quantitative in vitro autoradiography. Rats treated with a selective serotonin toxin (p-chloroamphetamine) showed a significant reduction of [(18)F]FPBM uptake in the cortex and hypothalamus regions of the brain. CONCLUSION The preliminary data suggest that [(18)F]FPBM and [(18)F]AV-133 may be useful for the examination of serotonergic and dopaminergic neuron integrity, respectively, in the living brain.
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Affiliation(s)
- Julie L Wang
- Department of Pharmacology, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA
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Abstract
The early detection and monitoring of neurodegenerative diseases, including Parkinson disease, Alzheimer disease, dementia with Lewy bodies and other dementias, and movement disorders, represent a significant unmet medical need. Tools for accurate and early differential diagnosis are necessary to determine the appropriate treatment for patients and to minimize inappropriate use of potentially harmful treatments. Such diagnostic imaging tools are expected to permit monitoring of disease progression and will thus accelerate testing and development of disease-modifying drugs. The new imaging tests may be useful as prognostic tools by identifying humans with neurodegenerative diseases before the clinical manifestations become evident.
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Tsao HH, Lin KJ, Juang JH, Skovronsky DM, Yen TC, Wey SP, Kung MP. Binding characteristics of 9-fluoropropyl-(+)-dihydrotetrabenzazine (AV-133) to the vesicular monoamine transporter type 2 in rats. Nucl Med Biol 2010; 37:413-9. [DOI: 10.1016/j.nucmedbio.2010.01.002] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2009] [Revised: 12/22/2009] [Accepted: 01/07/2010] [Indexed: 10/19/2022]
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Eriksson O, Jahan M, Johnström P, Korsgren O, Sundin A, Halldin C, Johansson L. In vivo and in vitro characterization of [18F]-FE-(+)-DTBZ as a tracer for beta-cell mass. Nucl Med Biol 2010; 37:357-63. [DOI: 10.1016/j.nucmedbio.2009.12.004] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2009] [Revised: 12/03/2009] [Accepted: 12/06/2009] [Indexed: 11/16/2022]
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An improved radiosynthesis of [18F]AV-133: a PET imaging agent for vesicular monoamine transporter 2. Nucl Med Biol 2010; 37:133-41. [DOI: 10.1016/j.nucmedbio.2009.10.005] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2009] [Revised: 10/23/2009] [Accepted: 10/26/2009] [Indexed: 11/23/2022]
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Zhu L, Liu J, Kung HF. Synthesis and evaluation of 2-amino-dihydrotetrabenzine derivatives as probes for imaging vesicular monoamine transporter-2. Bioorg Med Chem Lett 2009; 19:5026-8. [PMID: 19632829 DOI: 10.1016/j.bmcl.2009.07.048] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2009] [Revised: 07/07/2009] [Accepted: 07/08/2009] [Indexed: 11/29/2022]
Abstract
A novel series of analogs of 2-amino-dihydrotetrabenazine derivatives, 4-6, targeting the vesicular monoamine transporter have been prepared. In vitro binding was carried out in tissue homogenates prepared from rat striatal tissue homogenates with both [(125)I]-iodovinyl-TBZ and [(3)H]DTBZ. There was a good correlation (r(2)=0.925) between the affinities of the different compounds for [(125)I]-iodovinyl-TBZ and [(3)H]-DTBZ binding. Compound 5 exhibited a better affinity for the vesicular monoamine transporter (K(i)=8.68+/-1.26 nM and 7.01+/-0.07 nM, respectively), which may be a good lead compound for further structural modification to develop useful probes for VMAT2.
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Affiliation(s)
- Lin Zhu
- Key Laboratory of Radiopharmaceuticals (Beijing Normal University), Ministry of Education, Beijing, PR China
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Rishel MJ, Amarasinghe KKD, Dinn SR, Johnson BF. Asymmetric synthesis of tetrabenazine and dihydrotetrabenazine. J Org Chem 2009; 74:4001-4. [PMID: 19374381 DOI: 10.1021/jo900480n] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The enantioselective synthesis of (+)-tetrabenazine (TBZ) and (+)-dihydrotetrabenazine (DTBZ), agents of significant interest for therapeutic and molecular imaging applications, has been completed in 21% (TBZ) and 16% (DTBZ) overall yield and in >97% ee from the starting dihydroisoquinoline. The synthesis utilizes Sodeoka's palladium-catalyzed asymmetric malonate addition to set the initial stereocenter followed by a number of diastereoselective transformations to incorporate the remaining asymmetric centers.
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Affiliation(s)
- Michael J Rishel
- GE Global Research, One Research Circle, Niskayuna, New York 12309, USA.
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Kung MP, Hou C, Lieberman BP, Oya S, Ponde DE, Blankemeyer E, Skovronsky D, Kilbourn MR, Kung HF. In vivo imaging of beta-cell mass in rats using 18F-FP-(+)-DTBZ: a potential PET ligand for studying diabetes mellitus. J Nucl Med 2008; 49:1171-6. [PMID: 18552132 DOI: 10.2967/jnumed.108.051680] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
UNLABELLED Recent studies on gene expression of beta-cell mass (BCM) in the pancreas showed that vesicular monoamine transporter 2 (VMAT2) is highly expressed in the BCM (mainly in the islets of Langerhans). Imaging pancreatic BCM may provide an important tool for understanding the relationship between loss of insulin-secreting beta-cells and onset of diabetes mellitus. In this article, 9-fluoropropyl-(+)-dihydrotetrabenazine (FP-(+)-DTBZ), which is a VMAT2 imaging agent, was evaluated as a PET agent for estimating BCM in vivo. METHODS Organ biodistribution after an intravenous injection of (18)F-FP-(+)-DTBZ (active isomer) and (18)F-FP-(-)-DTBZ (inactive isomer) was evaluated in normal rats. The specificity of uptake of (18)F-FP-(+)-DTBZ was assessed by a pretreatment (3.8 mg of (+)-DTBZ per kilogram and 3.5 mg of FP-(+)-DTBZ per kilogram, intravenously, 5 min prior) or coadministration (2 mg of (+)-DTBZ per kilogram). PET studies were performed in normal rats. RESULTS The in vivo biodistribution of (18)F-FP-(+)-DTBZ in rats showed the highest uptake in the pancreas (5% dose/g at 30 min after injection), whereas (18)F-FP-(-)-DTBZ showed a very low pancreas uptake. Rats pretreated with FP-(+)-DTBZ displayed a 78% blockade of pancreas uptake. PET studies in normal rats demonstrated an avid pancreas uptake of (18)F-FP-(+)-DTBZ. CONCLUSION The preliminary data obtained with (18)F-FP-(+)-DTBZ suggest that this fluorinated derivative of DTBZ shows good pancreas specificity and has the potential to be useful for quantitative measurement of VMAT2 binding sites reflecting BCM in the pancreas.
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Affiliation(s)
- Mei-Ping Kung
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
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