151
|
Chen MK, Mecca AP, Naganawa M, Finnema SJ, Toyonaga T, Lin SF, Najafzadeh S, Ropchan J, Lu Y, McDonald JW, Michalak HR, Nabulsi NB, Arnsten AFT, Huang Y, Carson RE, van Dyck CH. Assessing Synaptic Density in Alzheimer Disease With Synaptic Vesicle Glycoprotein 2A Positron Emission Tomographic Imaging. JAMA Neurol 2019; 75:1215-1224. [PMID: 30014145 DOI: 10.1001/jamaneurol.2018.1836] [Citation(s) in RCA: 279] [Impact Index Per Article: 55.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Importance Synaptic loss is well established as the major structural correlate of cognitive impairment in Alzheimer disease (AD). The ability to measure synaptic density in vivo could accelerate the development of disease-modifying treatments for AD. Synaptic vesicle glycoprotein 2A is an essential vesicle membrane protein expressed in virtually all synapses and could serve as a suitable target for synaptic density. Objective To compare hippocampal synaptic vesicle glycoprotein 2A (SV2A) binding in participants with AD and cognitively normal participants using positron emission tomographic (PET) imaging. Design, Setting, and Participants This cross-sectional study recruited 10 participants with AD and 11 participants who were cognitively normal between November 2015 and June 2017. We hypothesized a reduction in hippocampal SV2A binding in AD, based on the early degeneration of entorhinal cortical cell projections to the hippocampus (via the perforant path) and hippocampal SV2A reductions that had been observed in postmortem studies. Participants underwent high-resolution PET scanning with ((R)-1-((3-(11C-methyl-11C)pyridin-4-yl)methyl)-4-(3,4,5-trifluorophenyl)pyrrolidin-2-one), a compound more commonly known as 11C-UCB-J, for SV2A. They also underwent high-resolution PET scanning with carbon 11-labeled Pittsburgh Compound B (11C-PiB) for β-amyloid, magnetic resonance imaging, and cognitive and neurologic evaluation. Main Outcomes and Measures Outcomes were 11C-UCB-J-specific binding (binding potential [BPND]) via PET imaging in brain regions of interest in participants with AD and participants who were cognitively normal. Results Ten participants with AD (5 male and 5 female; mean [SD] age, 72.7 [6.3] years; 10 [100%] β-amyloid positive) were compared with 11 participants who were cognitively normal (5 male and 6 female; mean [SD] age, 72.9 [8.7] years; 11 [100%] β-amyloid negative). Participants with AD spanned the disease stages from amnestic mild cognitive impairment (n = 5) to mild dementia (n = 5). Participants with AD had significant reduction in hippocampal SV2A specific binding (41%) compared with cognitively normal participants, as assessed by 11C-UCB-J-PET BPND (cognitively normal participants: mean [SD] BPND, 1.47 [0.37]; participants with AD: 0.87 [0.50]; P = .005). These reductions remained significant after correction for atrophy (ie, partial volume correction; participants who were cognitively normal: mean [SD], 2.71 [0.46]; participants with AD: 2.15 [0.55]; P = .02). Hippocampal SV2A-specific binding BPND was correlated with a composite episodic memory score in the overall sample (R = 0.56; P = .01). Conclusions and Relevance To our knowledge, this is the first study to investigate synaptic density in vivo in AD using 11C-UCB-J-PET imaging. This approach may provide a direct measure of synaptic density, and it therefore holds promise as an in vivo biomarker for AD and as an outcome measure for trials of disease-modifying therapies, particularly those targeted at the preservation and restoration of synapses.
Collapse
Affiliation(s)
- Ming-Kai Chen
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, Connecticut
| | - Adam P Mecca
- Department of Psychiatry, Yale University School of Medicine, New Haven, Connecticut
| | - Mika Naganawa
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, Connecticut
| | - Sjoerd J Finnema
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, Connecticut
| | - Takuya Toyonaga
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, Connecticut
| | - Shu-Fei Lin
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, Connecticut
| | - Soheila Najafzadeh
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, Connecticut
| | - Jim Ropchan
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, Connecticut
| | - Yihuan Lu
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, Connecticut
| | - Julia W McDonald
- Department of Psychiatry, Yale University School of Medicine, New Haven, Connecticut
| | - Hannah R Michalak
- Department of Psychiatry, Yale University School of Medicine, New Haven, Connecticut
| | - Nabeel B Nabulsi
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, Connecticut
| | - Amy F T Arnsten
- Department of Psychiatry, Yale University School of Medicine, New Haven, Connecticut
| | - Yiyun Huang
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, Connecticut
| | - Richard E Carson
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, Connecticut
| | | |
Collapse
|
152
|
Taddei C, Pike VW. [ 11C]Carbon monoxide: advances in production and application to PET radiotracer development over the past 15 years. EJNMMI Radiopharm Chem 2019; 4:25. [PMID: 31659516 PMCID: PMC6751244 DOI: 10.1186/s41181-019-0073-4] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Accepted: 07/22/2019] [Indexed: 12/18/2022] Open
Abstract
[11C]Carbon monoxide is an appealing synthon for introducing carbon-11 at a carbonyl position (C=O) in a wide variety of chemotypes (e.g., amides, ketones, acids, esters, and ureas). The prevalence of the carbonyl group in drug molecules and the present-day broad versatility of carbonylation reactions have led to an upsurge in the production of this synthon and in its application to PET radiotracer development. This review focuses on the major advances of the past 15 years.
Collapse
Affiliation(s)
- Carlotta Taddei
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, 10 Center Drive, Rm B3C342, Bethesda, MD, 20892-1003, USA.
| | - Victor W Pike
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, 10 Center Drive, Rm B3C342, Bethesda, MD, 20892-1003, USA
| |
Collapse
|
153
|
Trump L, Lemos A, Lallemand B, Pasau P, Mercier J, Lemaire C, Luxen A, Genicot C. Late-Stage 18 F-Difluoromethyl Labeling of N-Heteroaromatics with High Molar Activity for PET Imaging. Angew Chem Int Ed Engl 2019; 58:13149-13154. [PMID: 31323171 PMCID: PMC6790700 DOI: 10.1002/anie.201907488] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2019] [Revised: 07/16/2019] [Indexed: 01/22/2023]
Abstract
Despite a growing interest in CHF2 in medicinal chemistry, there is a lack of efficient methods for the insertion of CHF18 F into druglike compounds. Herein described is a photoredox flow reaction for 18 F-difluoromethylation of N-heteroaromatics that are widely used in medicinal chemistry. Following the two-step synthesis for a new 18 F-difluoromethylation reagent, the photoredox reaction is completed within two minutes and proceeds by C-H activation, circumventing the need for pre-functionalization of the substrate. The method is operationally simple and affords straightforward access to radiolabeled N-heteroaromatics with high molar activity suitable for biological in vivo studies and clinical application.
Collapse
Affiliation(s)
- Laura Trump
- Global Chemistry, UCB NewMedicinesUCB Biopharma sprl1420Braine-l'AlleudBelgium
- GIGA-CRC In Vivo ImagingCyclotron Research Center-B30Université de LiègeQuartier Agora, 6 allée du six août4000LiègeBelgium
| | - Agostinho Lemos
- GIGA-CRC In Vivo ImagingCyclotron Research Center-B30Université de LiègeQuartier Agora, 6 allée du six août4000LiègeBelgium
| | - Bénédicte Lallemand
- Global Chemistry, UCB NewMedicinesUCB Biopharma sprl1420Braine-l'AlleudBelgium
| | - Patrick Pasau
- Global Chemistry, UCB NewMedicinesUCB Biopharma sprl1420Braine-l'AlleudBelgium
| | - Joël Mercier
- Global Chemistry, UCB NewMedicinesUCB Biopharma sprl1420Braine-l'AlleudBelgium
| | - Christian Lemaire
- GIGA-CRC In Vivo ImagingCyclotron Research Center-B30Université de LiègeQuartier Agora, 6 allée du six août4000LiègeBelgium
| | - André Luxen
- GIGA-CRC In Vivo ImagingCyclotron Research Center-B30Université de LiègeQuartier Agora, 6 allée du six août4000LiègeBelgium
| | - Christophe Genicot
- Global Chemistry, UCB NewMedicinesUCB Biopharma sprl1420Braine-l'AlleudBelgium
| |
Collapse
|
154
|
AD molecular: Molecular imaging of Alzheimer's disease: PET imaging of neurotransmitter systems. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2019. [PMID: 31481161 DOI: 10.1016/bs.pmbts.2019.04.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
Current understanding of Alzheimer's disease (AD) pathogenesis relies on the observed accumulations of amyloid β and phosphorylated tau aggregates that are thought to play key roles in initiating or propagating disease. However, other processes including changes in synaptic proteins and neurotransmitter loss have been suggested as important etiologies or contributors. Positron emission tomography (PET) imaging allows in vivo investigations of molecular changes associated with AD. PET imaging with multiple radiotracers can be used in combination with other modalities such as magnetic resonance imaging (MRI), and with assessments of cognition and neuropsychiatric symptoms to investigate the molecular underpinnings of AD. Studies of synaptic protein changes may improve the understanding of disease mechanisms and provide valuable markers of disease progression and therapeutic efficacy. This chapter will illustrate the importance of in vivo molecular imaging in the study of AD with a specific emphasis on PET and radioligands for several non-amyloid targets.
Collapse
|
155
|
In vivo imaging of synaptic loss in Alzheimer's disease with [18F]UCB-H positron emission tomography. Eur J Nucl Med Mol Imaging 2019; 47:390-402. [PMID: 31468182 DOI: 10.1007/s00259-019-04461-x] [Citation(s) in RCA: 67] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Accepted: 07/24/2019] [Indexed: 11/27/2022]
Abstract
PURPOSE Loss of brain synapses is an early pathological feature of Alzheimer's disease. The current study assessed synaptic loss in vivo with positron emission tomography and an 18F-labelled radiotracer of the synaptic vesicle protein 2A, [18F]UCB-H. METHODS Twenty-four patients with mild cognitive impairment or Alzheimer's disease and positive [18F]Flutemetamol amyloid-PET were compared to 19 healthy controls. [18F]UCB-H brain uptake was quantified with Logan graphical analysis using an image-derived blood input function. SPM12 and regions-of-interest (ROI) analyses were used for group comparisons of regional brain distribution volumes and for correlation with cognitive measures. RESULTS A significant decrease of [18F]UCB-H uptake was observed in several cortical areas (11 to 18% difference) and in the thalamus (16% difference), with the largest effect size in the hippocampus (31% difference). Reduced hippocampal uptake was related to patients' cognitive decline (ROI analysis) and unawareness of memory problems (SPM and ROI analyses). CONCLUSIONS The findings thus highlight predominant synaptic loss in the hippocampus, confirming previous autopsy-based studies and a recent PET study with an 11C-labelled SV2A radiotracer. [18F]UCB-H PET allows to image in vivo synaptic changes in Alzheimer's disease and to relate them to patients' cognitive impairment.
Collapse
|
156
|
Trump L, Lemos A, Lallemand B, Pasau P, Mercier J, Lemaire C, Luxen A, Genicot C. Late‐Stage
18
F‐Difluoromethyl Labeling of N‐Heteroaromatics with High Molar Activity for PET Imaging. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201907488] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Laura Trump
- Global Chemistry, UCB NewMedicines UCB Biopharma sprl 1420 Braine-l'Alleud Belgium
- GIGA-CRC In Vivo Imaging Cyclotron Research Center-B30 Université de Liège Quartier Agora, 6 allée du six août 4000 Liège Belgium
| | - Agostinho Lemos
- GIGA-CRC In Vivo Imaging Cyclotron Research Center-B30 Université de Liège Quartier Agora, 6 allée du six août 4000 Liège Belgium
| | - Bénédicte Lallemand
- Global Chemistry, UCB NewMedicines UCB Biopharma sprl 1420 Braine-l'Alleud Belgium
| | - Patrick Pasau
- Global Chemistry, UCB NewMedicines UCB Biopharma sprl 1420 Braine-l'Alleud Belgium
| | - Joël Mercier
- Global Chemistry, UCB NewMedicines UCB Biopharma sprl 1420 Braine-l'Alleud Belgium
| | - Christian Lemaire
- GIGA-CRC In Vivo Imaging Cyclotron Research Center-B30 Université de Liège Quartier Agora, 6 allée du six août 4000 Liège Belgium
| | - André Luxen
- GIGA-CRC In Vivo Imaging Cyclotron Research Center-B30 Université de Liège Quartier Agora, 6 allée du six août 4000 Liège Belgium
| | - Christophe Genicot
- Global Chemistry, UCB NewMedicines UCB Biopharma sprl 1420 Braine-l'Alleud Belgium
| |
Collapse
|
157
|
Mansur A, Rabiner EA, Comley RA, Lewis Y, Middleton LT, Huiban M, Passchier J, Tsukada H, Gunn RN. Characterization of 3 PET Tracers for Quantification of Mitochondrial and Synaptic Function in Healthy Human Brain: 18F-BCPP-EF, 11C-SA-4503, and 11C-UCB-J. J Nucl Med 2019; 61:96-103. [PMID: 31324712 DOI: 10.2967/jnumed.119.228080] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Accepted: 06/04/2019] [Indexed: 11/16/2022] Open
Abstract
Mitochondrial complex 1 is involved in maintaining brain bioenergetics; σ-1 receptor responds to neuronal stress; and synaptic vesicle protein 2A reflects synaptic integrity. Expression of each of these proteins is altered in neurodegenerative diseases. Here, we characterize the kinetic behavior of 3 PET radioligands-18F-BCPP-EF, 11C-SA-4503, and 11C-UCB-J-for the measurement of mitochondrial complex 1, σ-1 receptor, and synaptic vesicle protein 2A, respectively, and determine appropriate analysis workflows for their application in future studies of the in vivo molecular pathology of these diseases. Methods: Twelve human subjects underwent dynamic PET scans with each radioligand, including associated arterial blood sampling. A range of kinetic models was investigated to identify an optimal kinetic analysis method for each radioligand and a suitable acquisition duration. Results: All 3 radioligands readily entered the brain and yielded heterogeneous uptake consistent with the known distribution of the targets. The optimal models determined for the regional estimates of volume of distribution were multilinear analysis 1 (MA1) and the 2-tissue-compartment model for 18F-BCPP-EF, MA1 for 11C-SA-4503, and both MA1 and the 1-tissue-compartment model for 11C-UCB-J. Acquisition times of 70, 80, and 60 min for 18F-BCPP-EF, 11C-SA-4503, 11C-UCB-J, respectively, provided good estimates of regional volume of distribution values. An effect of age was observed on 18F-BCPP-EF and 11C-UCB-J signal in the caudate. Conclusion: These ligands can be assessed for their potential to stratify patients or monitor the progression of molecular neuropathology in neurodegenerative diseases.
Collapse
Affiliation(s)
- Ayla Mansur
- Invicro LLC, London, United Kingdom .,Division of Brain Sciences, Imperial College London, London, United Kingdom
| | - Eugenii A Rabiner
- Invicro LLC, London, United Kingdom.,King's College London, London, United Kingdom
| | | | | | - Lefkos T Middleton
- Neuroepidemiology and Ageing Research Unit, Imperial College London, London, United Kingdom; and
| | | | - Jan Passchier
- Invicro LLC, London, United Kingdom.,Division of Brain Sciences, Imperial College London, London, United Kingdom
| | - Hideo Tsukada
- Hamamatsu Photonics, Hamamatsu City, Shizuoka, Japan
| | | | | |
Collapse
|
158
|
|
159
|
Synthesis and in vivo evaluation of [ 18F]UCB-J for PET imaging of synaptic vesicle glycoprotein 2A (SV2A). Eur J Nucl Med Mol Imaging 2019; 46:1952-1965. [PMID: 31175396 DOI: 10.1007/s00259-019-04357-w] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Accepted: 05/02/2019] [Indexed: 02/05/2023]
Abstract
PURPOSE Synaptic abnormalities have been implicated in a variety of neuropsychiatric disorders, including epilepsy, Alzheimer's disease, and schizophrenia. Hence, PET imaging of the synaptic vesicle glycoprotein 2A (SV2A) may be a valuable in vivo biomarker for neurologic and psychiatric diseases. We previously developed [11C]UCB-J, a PET radiotracer with high affinity and selectivity toward SV2A; however, the short radioactive half-life (20 min for 11C) places some limitations on its broader application. Herein, we report the first synthesis of the longer-lived 18F-labeled counterpart (half-life: 110 min), [18F]UCB-J, and its evaluation in nonhuman primates. METHODS [18F]UCB-J was synthesized from the iodonium precursors. PET imaging experiments with [18F]UCB-J were conducted in rhesus monkeys to assess the pharmacokinetic and in vivo binding properties. Arterial samples were taken for analysis of radioactive metabolites and generation of input functions. Regional time-activity curves were analyzed using the one-tissue compartment model to derive regional distribution volumes and binding potentials for comparison with [11C]UCB-J. RESULTS [18F]UCB-J was prepared in high radiochemical and enantiomeric purity, but low radiochemical yield. Evaluation in nonhuman primates indicated that the radiotracer displayed pharmacokinetic and imaging characteristics similar to those of [11C]UCB-J, with moderate metabolism rate, high brain uptake, fast and reversible binding kinetics, and high specific binding signals. CONCLUSION We have accomplished the first synthesis of the novel SV2A radiotracer [18F]UCB-J. [18F]UCB-J is demonstrated to be an excellent imaging agent and may prove to be useful for imaging and quantification of SV2A expression, and synaptic density, in humans.
Collapse
|
160
|
Márquez F, Yassa MA. Neuroimaging Biomarkers for Alzheimer's Disease. Mol Neurodegener 2019; 14:21. [PMID: 31174557 PMCID: PMC6555939 DOI: 10.1186/s13024-019-0325-5] [Citation(s) in RCA: 129] [Impact Index Per Article: 25.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Accepted: 05/28/2019] [Indexed: 12/11/2022] Open
Abstract
Currently, over five million Americans suffer with Alzheimer's disease (AD). In the absence of a cure, this number could increase to 13.8 million by 2050. A critical goal of biomedical research is to establish indicators of AD during the preclinical stage (i.e. biomarkers) allowing for early diagnosis and intervention. Numerous advances have been made in developing biomarkers for AD using neuroimaging approaches. These approaches offer tremendous versatility in terms of targeting distinct age-related and pathophysiological mechanisms such as structural decline (e.g. volumetry, cortical thinning), functional decline (e.g. fMRI activity, network correlations), connectivity decline (e.g. diffusion anisotropy), and pathological aggregates (e.g. amyloid and tau PET). In this review, we survey the state of the literature on neuroimaging approaches to developing novel biomarkers for the amnestic form of AD, with an emphasis on combining approaches into multimodal biomarkers. We also discuss emerging methods including imaging epigenetics, neuroinflammation, and synaptic integrity using PET tracers. Finally, we review the complementary information that neuroimaging biomarkers provide, which highlights the potential utility of composite biomarkers as suitable outcome measures for proof-of-concept clinical trials with experimental therapeutics.
Collapse
Affiliation(s)
- Freddie Márquez
- Department of Neurobiology and Behavior, Center for the Neurobiology of Learning and Memory, University of California Irvine, Irvine, CA, 92697, USA.
| | - Michael A Yassa
- Department of Neurobiology and Behavior, Center for the Neurobiology of Learning and Memory, University of California Irvine, Irvine, CA, 92697, USA.
| |
Collapse
|
161
|
Toyonaga T, Smith LM, Finnema SJ, Gallezot JD, Naganawa M, Bini J, Mulnix T, Cai Z, Ropchan J, Huang Y, Strittmatter SM, Carson RE. In Vivo Synaptic Density Imaging with 11C-UCB-J Detects Treatment Effects of Saracatinib in a Mouse Model of Alzheimer Disease. J Nucl Med 2019; 60:1780-1786. [PMID: 31101744 DOI: 10.2967/jnumed.118.223867] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2018] [Accepted: 05/13/2019] [Indexed: 11/16/2022] Open
Abstract
11C-UCB-J is a new PET tracer for synaptic density imaging. Recently, we conducted 11C-UCB-J PET on patients with mild cognitive impairment or early Alzheimer disease (AD) and found a 41% decrease in specific binding in the hippocampus compared with healthy subjects. We hypothesized that 11C-UCB-J may have potential to be a general biomarker for evaluating AD treatment effects via monitoring of synaptic density changes. In this study, we performed longitudinal 11C-UCB-J PET on AD mice to measure the treatment effects of saracatinib, which previously demonstrated synaptic changes with postmortem methods. Methods: Nine wild-type (WT) mice and 9 amyloid precursor protein and presenilin 1 double-transgenic (APPswe/PS1ΔE9 [APP/PS1]) mice underwent 3 11C-UCB-J PET measurements: at baseline, after treatment, and during drug washout. After baseline measurements, saracatinib, a Fyn kinase inhibitor currently in clinical development for AD treatment, was administered by oral gavage for 41 ± 11 d. Treatment-phase measurements were performed on the last day of treatment, and washout-phase measurements occurred more than 27 d after the end of treatment. SUVs from 30 to 60 min after injection of 11C-UCB-J were calculated and normalized by the whole-brain (WB) or brain stem (BS) average values as SUV ratio (SUVR(WB) or SUVR-1(BS)). Results: Hippocampal SUVR(WB) at baseline was significantly lower in APP/PS1 than WT mice (APP/PS1: 1.11 ± 0.04, WT: 1.15 ± 0.02, P = 0.033, unpaired t test). Using SUVR-1(BS) in the hippocampus, there was also a significant difference at baseline (APP/PS1: 0.48 ± 0.13, WT: 0.65 ± 0.10, P = 0.017, unpaired t test). After treatment with saracatinib, hippocampal SUVR(WB) in APP/PS1 mice was significantly increased (P = 0.037, paired t test). A trend-level treatment effect was seen with hippocampal SUVR-1(BS). Saracatinib treatment effects may persist, as there were no significant differences between WT and APP/PS1 mice after drug washout. Conclusion: On the basis of the 11C-UCB-J PET results, hippocampal synaptic density was lower in APP/PS1 mice than in WT mice at baseline, and this deficit was normalized by treatment with saracatinib. These results support the use of 11C-UCB-J PET to identify disease-specific synaptic deficits and to monitor treatment effects in AD.
Collapse
Affiliation(s)
- Takuya Toyonaga
- PET Center, Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, Connecticut
| | - Levi M Smith
- Department of Cell Biology, Yale University School of Medicine, New Haven, Connecticut.,Program in Cellular Neuroscience, Neurodegeneration, and Repair, Yale University School of Medicine, New Haven, Connecticut; and
| | - Sjoerd J Finnema
- PET Center, Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, Connecticut
| | - Jean-Dominique Gallezot
- PET Center, Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, Connecticut
| | - Mika Naganawa
- PET Center, Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, Connecticut
| | - Jason Bini
- PET Center, Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, Connecticut
| | - Tim Mulnix
- PET Center, Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, Connecticut
| | - Zhengxin Cai
- PET Center, Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, Connecticut
| | - Jim Ropchan
- PET Center, Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, Connecticut
| | - Yiyun Huang
- PET Center, Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, Connecticut
| | - Stephen M Strittmatter
- Program in Cellular Neuroscience, Neurodegeneration, and Repair, Yale University School of Medicine, New Haven, Connecticut; and.,Department of Neurology, Yale University School of Medicine, New Haven, Connecticut
| | - Richard E Carson
- PET Center, Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, Connecticut
| |
Collapse
|
162
|
Finnema SJ, Rossano S, Naganawa M, Henry S, Gao H, Pracitto R, Maguire RP, Mercier J, Kervyn S, Nicolas J, Klitgaard H, DeBruyn S, Otoul C, Martin P, Muglia P, Matuskey D, Nabulsi NB, Huang Y, Kaminski RM, Hannestad J, Stockis A, Carson RE. A single-center, open-label positron emission tomography study to evaluate brivaracetam and levetiracetam synaptic vesicle glycoprotein 2A binding in healthy volunteers. Epilepsia 2019; 60:958-967. [PMID: 30924924 PMCID: PMC6532410 DOI: 10.1111/epi.14701] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Revised: 03/03/2019] [Accepted: 03/04/2019] [Indexed: 02/06/2023]
Abstract
OBJECTIVE Brivaracetam (BRV) and levetiracetam (LEV) are antiepileptic drugs that bind synaptic vesicle glycoprotein 2A (SV2A). In vitro and in vivo animal studies suggest faster brain penetration and SV2A occupancy (SO) after dosing with BRV than LEV. We evaluated human brain penetration and SO time course of BRV and LEV at therapeutically relevant doses using the SV2A positron emission tomography (PET) tracer 11 C-UCB-J (EP0074; NCT02602860). METHODS Healthy volunteers were recruited into three cohorts. Cohort 1 (n = 4) was examined with PET at baseline and during displacement after intravenous BRV (100 mg) or LEV (1500 mg). Cohort 2 (n = 5) was studied during displacement and 4 hours postdose (BRV 50-200 mg or LEV 1500 mg). Cohort 3 (n = 4) was examined at baseline and steady state after 4 days of twice-daily oral dosing of BRV (50-100 mg) and 4 hours postdose of LEV (250-600 mg). Half-time of 11 C-UCB-J signal change was computed from displacement measurements. Half-saturation concentrations (IC50 ) were determined from calculated SO. RESULTS Observed tracer displacement half-times were 18 ± 6 minutes for BRV (100 mg, n = 4), 9.7 and 10.1 minutes for BRV (200 mg, n = 2), and 28 ± 6 minutes for LEV (1500 mg, n = 6). Estimated corrected half-times were 8 minutes shorter. The SO was 66%-70% for 100 mg intravenous BRV, 84%-85% for 200 mg intravenous BRV, and 78%-84% for intravenous 1500 mg LEV. The IC50 of BRV (0.46 μg/mL) was 8.7-fold lower than of LEV (4.02 μg/mL). BRV data fitted a single SO versus plasma concentration relationship. Steady state SO for 100 mg BRV was 86%-87% (peak) and 76%-82% (trough). SIGNIFICANCE BRV achieves high SO more rapidly than LEV when intravenously administered at therapeutic doses. Thus, BRV may have utility in treating acute seizures; further clinical studies are needed for confirmation.
Collapse
Affiliation(s)
- Sjoerd J. Finnema
- Department of Radiology and Biomedical ImagingPositron Emission Tomography CenterYale UniversityNew HavenConnecticut
| | - Samantha Rossano
- Department of Radiology and Biomedical ImagingPositron Emission Tomography CenterYale UniversityNew HavenConnecticut
- Department of Biomedical EngineeringYale UniversityNew HavenConnecticut
| | - Mika Naganawa
- Department of Radiology and Biomedical ImagingPositron Emission Tomography CenterYale UniversityNew HavenConnecticut
| | - Shannan Henry
- Department of Radiology and Biomedical ImagingPositron Emission Tomography CenterYale UniversityNew HavenConnecticut
| | - Hong Gao
- Department of Radiology and Biomedical ImagingPositron Emission Tomography CenterYale UniversityNew HavenConnecticut
| | - Richard Pracitto
- Department of Radiology and Biomedical ImagingPositron Emission Tomography CenterYale UniversityNew HavenConnecticut
| | | | | | | | | | | | | | | | | | | | - David Matuskey
- Department of Radiology and Biomedical ImagingPositron Emission Tomography CenterYale UniversityNew HavenConnecticut
| | - Nabeel B. Nabulsi
- Department of Radiology and Biomedical ImagingPositron Emission Tomography CenterYale UniversityNew HavenConnecticut
| | - Yiyun Huang
- Department of Radiology and Biomedical ImagingPositron Emission Tomography CenterYale UniversityNew HavenConnecticut
| | | | | | | | - Richard E. Carson
- Department of Radiology and Biomedical ImagingPositron Emission Tomography CenterYale UniversityNew HavenConnecticut
- Department of Biomedical EngineeringYale UniversityNew HavenConnecticut
| |
Collapse
|
163
|
Evaluating the In Vivo Specificity of [ 18F]UCB-H for the SV2A Protein, Compared with SV2B and SV2C in Rats Using microPET. Molecules 2019; 24:molecules24091705. [PMID: 31052478 PMCID: PMC6538996 DOI: 10.3390/molecules24091705] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Revised: 04/28/2019] [Accepted: 04/29/2019] [Indexed: 11/25/2022] Open
Abstract
The synaptic vesicle protein 2 (SV2) is involved in synaptic vesicle trafficking. The SV2A isoform is the most studied and its implication in epilepsy therapy led to the development of the first SV2A PET radiotracer [18F]UCB-H. The objective of this study was to evaluate in vivo, using microPET in rats, the specificity of [18F]UCB-H for SV2 isoform A in comparison with the other two isoforms (B and C) through a blocking assay. Twenty Sprague Dawley rats were pre-treated either with the vehicle, or with specific competitors against SV2A (levetiracetam), SV2B (UCB5203) and SV2C (UCB0949). The distribution volume (Vt, Logan plot, t* 15 min) was obtained with a population-based input function. The Vt analysis for the entire brain showed statistically significant differences between the levetiracetam group and the other groups (p < 0.001), but also between the vehicle and the SV2B group (p < 0.05). An in-depth Vt analysis conducted for eight relevant brain structures confirmed the statistically significant differences between the levetiracetam group and the other groups (p < 0.001) and highlighted the superior and the inferior colliculi along with the cortex as regions also displaying statistically significant differences between the vehicle and SV2B groups (p < 0.05). These results emphasize the in vivo specificity of [18F]UCB-H for SV2A against SV2B and SV2C, confirming that [18F]UCB-H is a suitable radiotracer for in vivo imaging of the SV2A proteins with PET.
Collapse
|
164
|
Holmes SE, Scheinost D, Finnema SJ, Naganawa M, Davis MT, DellaGioia N, Nabulsi N, Matuskey D, Angarita GA, Pietrzak RH, Duman RS, Sanacora G, Krystal JH, Carson RE, Esterlis I. Lower synaptic density is associated with depression severity and network alterations. Nat Commun 2019; 10:1529. [PMID: 30948709 PMCID: PMC6449365 DOI: 10.1038/s41467-019-09562-7] [Citation(s) in RCA: 249] [Impact Index Per Article: 49.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Accepted: 03/18/2019] [Indexed: 12/21/2022] Open
Abstract
Synaptic loss and deficits in functional connectivity are hypothesized to contribute to symptoms associated with major depressive disorder (MDD) and post-traumatic stress disorder (PTSD). The synaptic vesicle glycoprotein 2A (SV2A) can be used to index the number of nerve terminals, an indirect estimate of synaptic density. Here, we used positron emission tomography (PET) with the SV2A radioligand [11C]UCB-J to examine synaptic density in n = 26 unmedicated individuals with MDD, PTSD, or comorbid MDD/PTSD. The severity of depressive symptoms was inversely correlated with SV2A density, and individuals with high levels of depression showing lower SV2A density compared to healthy controls (n = 21). SV2A density was also associated with aberrant network function, as measured by magnetic resonance imaging (MRI) functional connectivity. This is the first in vivo evidence linking lower synaptic density to network alterations and symptoms of depression. Our findings provide further incentive to evaluate interventions that restore synaptic connections to treat depression.
Collapse
Affiliation(s)
- Sophie E Holmes
- Department of Psychiatry, Yale School of Medicine, New Haven, CT, 06511, USA
| | - Dustin Scheinost
- Radiology and Biomedical Imaging, Yale School of Medicine, New Haven, CT, 06511, USA
| | - Sjoerd J Finnema
- Department of Psychiatry, Yale School of Medicine, New Haven, CT, 06511, USA
| | - Mika Naganawa
- Radiology and Biomedical Imaging, Yale School of Medicine, New Haven, CT, 06511, USA
| | - Margaret T Davis
- Department of Psychiatry, Yale School of Medicine, New Haven, CT, 06511, USA
| | - Nicole DellaGioia
- Department of Psychiatry, Yale School of Medicine, New Haven, CT, 06511, USA
| | - Nabeel Nabulsi
- Radiology and Biomedical Imaging, Yale School of Medicine, New Haven, CT, 06511, USA
| | - David Matuskey
- Department of Psychiatry, Yale School of Medicine, New Haven, CT, 06511, USA
- Radiology and Biomedical Imaging, Yale School of Medicine, New Haven, CT, 06511, USA
| | - Gustavo A Angarita
- Department of Psychiatry, Yale School of Medicine, New Haven, CT, 06511, USA
| | - Robert H Pietrzak
- Department of Psychiatry, Yale School of Medicine, New Haven, CT, 06511, USA
- U.S. Department of Veteran Affairs National Center for Posttraumatic Stress Disorder, Clinical Neurosciences Division, VA Connecticut Healthcare System, West Haven, CT, 06516, USA
| | - Ronald S Duman
- Department of Psychiatry, Yale School of Medicine, New Haven, CT, 06511, USA
| | - Gerard Sanacora
- Department of Psychiatry, Yale School of Medicine, New Haven, CT, 06511, USA
| | - John H Krystal
- Department of Psychiatry, Yale School of Medicine, New Haven, CT, 06511, USA
- U.S. Department of Veteran Affairs National Center for Posttraumatic Stress Disorder, Clinical Neurosciences Division, VA Connecticut Healthcare System, West Haven, CT, 06516, USA
| | - Richard E Carson
- Radiology and Biomedical Imaging, Yale School of Medicine, New Haven, CT, 06511, USA
| | - Irina Esterlis
- Department of Psychiatry, Yale School of Medicine, New Haven, CT, 06511, USA.
- U.S. Department of Veteran Affairs National Center for Posttraumatic Stress Disorder, Clinical Neurosciences Division, VA Connecticut Healthcare System, West Haven, CT, 06516, USA.
| |
Collapse
|
165
|
Li S, Cai Z, Wu X, Holden D, Pracitto R, Kapinos M, Gao H, Labaree D, Nabulsi N, Carson RE, Huang Y. Synthesis and in Vivo Evaluation of a Novel PET Radiotracer for Imaging of Synaptic Vesicle Glycoprotein 2A (SV2A) in Nonhuman Primates. ACS Chem Neurosci 2019; 10:1544-1554. [PMID: 30396272 PMCID: PMC6810685 DOI: 10.1021/acschemneuro.8b00526] [Citation(s) in RCA: 66] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Structural disruption and alterations of synapses are associated with many brain disorders including Alzheimer's disease, epilepsy, depression, and schizophrenia. We have previously developed the PET radiotracer 11C-UCB-J for imaging and quantification of synaptic vesicle glycoprotein 2A (SV2A) and synaptic density in nonhuman primates and humans. Here we report the synthesis of a novel radiotracer 18F-SDM-8 and its in vivo evaluation in rhesus monkeys. The in vitro binding assay of SDM-8 showed high SV2A binding affinity ( Ki = 0.58 nM). 18F-SDM-8 was prepared in high molar activity (241.7 MBq/nmol) and radiochemical purity (>98%). In the brain, 18F-SDM-8 displayed very high uptake with peak standardized uptake value (SVU) greater than 8 and fast and reversible kinetics. A displacement study with levetiracetam and blocking studies with UCB-J and levetiracetam demonstrated its binding reversibility and specificity toward SV2A. Regional binding potential values were calculated and ranged from 0.8 in the brainstem to 4.5 in the cingulate cortex. By comparing to 11C-UCB-J, 18F-SDM-8 displayed the same attractive imaging properties: very high brain uptake, appropriate tissue kinetics, and high levels of specific binding. Given the longer half-life of F-18 and the feasibility for central production and multisite distribution, 18F-SDM-8 holds promise as an excellent radiotracer for SV2A and as a biomarker for synaptic density measurement in neurodegenerative diseases and psychiatric disorders.
Collapse
Affiliation(s)
- Songye Li
- PET Center, Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, Connecticut 06520, United States
| | - Zhengxin Cai
- PET Center, Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, Connecticut 06520, United States
| | - Xiaoai Wu
- Department of Nuclear Medicine, West China Hospital, Laboratory of Clinical Nuclear Medicine, West China Hospital, Sichuan University, Chengdu 610041, Sichuan Province, China
| | - Daniel Holden
- PET Center, Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, Connecticut 06520, United States
| | - Richard Pracitto
- PET Center, Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, Connecticut 06520, United States
| | - Michael Kapinos
- PET Center, Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, Connecticut 06520, United States
| | - Hong Gao
- PET Center, Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, Connecticut 06520, United States
| | - David Labaree
- PET Center, Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, Connecticut 06520, United States
| | - Nabeel Nabulsi
- PET Center, Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, Connecticut 06520, United States
| | - Richard E. Carson
- PET Center, Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, Connecticut 06520, United States
| | - Yiyun Huang
- PET Center, Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, Connecticut 06520, United States
| |
Collapse
|
166
|
Nabulsi NB, Holden D, Zheng MQ, Bois F, Lin SF, Najafzadeh S, Gao H, Ropchan J, Lara-Jaime T, Labaree D, Shirali A, Slieker L, Jesudason C, Barth V, Navarro A, Kant N, Carson RE, Huang Y. Evaluation of 11C-LSN3172176 as a Novel PET Tracer for Imaging M 1 Muscarinic Acetylcholine Receptors in Nonhuman Primates. J Nucl Med 2019; 60:1147-1153. [PMID: 30733324 DOI: 10.2967/jnumed.118.222034] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Accepted: 12/29/2018] [Indexed: 11/16/2022] Open
Abstract
The M1 muscarinic acetylcholine receptor (mAChR) plays an important role in learning and memory, and therefore is a target for development of drugs for treatment of cognitive impairments in Alzheimer disease and schizophrenia. The availability of M1-selective radiotracers for PET will help in developing therapeutic agents by providing an imaging tool for assessment of drug dose-receptor occupancy relationship. Here we report the synthesis and evaluation of 11C-LSN3172176 (ethyl 4-(6-(methyl-11 C)-2-oxoindolin-1-yl)-[1,4'-bipiperidine]-1'-carboxylate) in nonhuman primates. Methods: 11C-LSN3172176 was radiolabeled via the Suzuki-Miyaura cross-coupling method. PET scans in rhesus macaques were acquired for 2 h with arterial blood sampling and metabolite analysis to measure the input function. Blocking scans with scopolamine (50 μg/kg) and the M1-selective agent AZD6088 (0.67 and 2 mg/kg) were obtained to assess tracer binding specificity and selectivity. Regional brain time-activity curves were analyzed with the 1-tissue-compartment model and the multilinear analysis method (MA1) to calculate regional distribution volume. Nondisplaceable binding potential values were calculated using the cerebellum as a reference region. Results: 11C-LSN3172176 was synthesized with greater than 99% radiochemical purity and high molar activity. In rhesus monkeys, 11C-LSN3172176 metabolized rapidly (29% ± 6% parent remaining at 15 min) and displayed fast kinetics and extremely high uptake in the brain. Imaging data were modeled well with the 1-tissue-compartment model and MA1 methods. MA1-derived distribution volume values were high (range, 10-81 mL/cm3) in all known M1 mAChR-rich brain regions. Pretreatment with scopolamine and AZD6088 significantly reduced the brain uptake of 11C-LSN3172176, thus demonstrating its binding specificity and selectivity in vivo. The cerebellum appeared to be a suitable reference region for derivation of nondisplaceable binding potential, which ranged from 2.42 in the globus pallidus to 8.48 in the nucleus accumbens. Conclusion: 11C-LSN3172176 exhibits excellent in vivo binding and imaging characteristics in nonhuman primates and appears to be the first appropriate radiotracer for PET imaging of human M1 AChR.
Collapse
Affiliation(s)
- Nabeel B Nabulsi
- Yale PET Center, Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT; and
| | - Daniel Holden
- Yale PET Center, Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT; and
| | - Ming-Qiang Zheng
- Yale PET Center, Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT; and
| | - Frederic Bois
- Yale PET Center, Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT; and
| | - Shu-Fei Lin
- Yale PET Center, Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT; and
| | - Soheila Najafzadeh
- Yale PET Center, Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT; and
| | - Hong Gao
- Yale PET Center, Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT; and
| | - Jim Ropchan
- Yale PET Center, Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT; and
| | - Teresa Lara-Jaime
- Yale PET Center, Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT; and
| | - David Labaree
- Yale PET Center, Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT; and
| | - Anupama Shirali
- Yale PET Center, Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT; and
| | | | | | | | | | - Nancy Kant
- Eli Lilly and Co., Indianapolis, Indiana
| | - Richard E Carson
- Yale PET Center, Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT; and
| | - Yiyun Huang
- Yale PET Center, Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT; and
| |
Collapse
|
167
|
Cai Z, Li S, Matuskey D, Nabulsi N, Huang Y. PET imaging of synaptic density: A new tool for investigation of neuropsychiatric diseases. Neurosci Lett 2019; 691:44-50. [PMID: 30075287 PMCID: PMC6339829 DOI: 10.1016/j.neulet.2018.07.038] [Citation(s) in RCA: 77] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Revised: 07/25/2018] [Accepted: 07/26/2018] [Indexed: 12/14/2022]
Abstract
Synaptic vesicle glycoprotein 2A (SV2A) is expressed ubiquitously in neurons of the central nervous system, and is the binding target of the anti-epileptic drug levetiracetam. Because of the availability of positron emission tomography (PET) ligands targeting SV2A, there is increasing enthusiasm on the use of SV2A PET to study a variety of neuropsychiatric diseases. This review discusses the recent development of radioligands for PET imaging of SV2A and their potential use in the research and diagnosis of CNS diseases.
Collapse
Affiliation(s)
- Zhengxin Cai
- PET Center, Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT 06520, USA.
| | - Songye Li
- PET Center, Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT 06520, USA
| | - David Matuskey
- PET Center, Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT 06520, USA
| | - Nabeel Nabulsi
- PET Center, Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT 06520, USA
| | - Yiyun Huang
- PET Center, Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT 06520, USA
| |
Collapse
|
168
|
Finnema SJ, Nabulsi NB, Mercier J, Lin SF, Chen MK, Matuskey D, Gallezot JD, Henry S, Hannestad J, Huang Y, Carson RE. Kinetic evaluation and test-retest reproducibility of [ 11C]UCB-J, a novel radioligand for positron emission tomography imaging of synaptic vesicle glycoprotein 2A in humans. J Cereb Blood Flow Metab 2018; 38:2041-2052. [PMID: 28792356 PMCID: PMC6259313 DOI: 10.1177/0271678x17724947] [Citation(s) in RCA: 135] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2016] [Revised: 07/07/2017] [Accepted: 07/09/2017] [Indexed: 11/15/2022]
Abstract
Synaptic vesicle glycoprotein 2A (SV2A) is ubiquitously present in presynaptic terminals. Here we report kinetic modeling and test-retest reproducibility assessment of the SV2A positron emission tomography (PET) radioligand [11C]UCB-J in humans. Five volunteers were examined twice on the HRRT after bolus injection of [11C]UCB-J. Arterial blood samples were collected for measurements of radiometabolites and free fraction. Regional time-activity curves were analyzed with 1-tissue (1T) and 2-tissue (2T) compartment models to estimate volumes of distribution ( VT). Parametric maps were generated using the 1T model. [11C]UCB-J metabolized fairly quickly, with parent fraction of 36 ± 13% at 15 min after injection. Plasma free fraction was 32 ± 1%. Regional time-activity curves displayed rapid kinetics and were well described by the 1T model, except for the cerebellum and hippocampus. VT values estimated with the 2T model were similar to 1T values. Parametric maps were of high quality and VT values correlated well with time activity curve (TAC)-based estimates. Shortening of acquisition time from 120 min to 60 min had a negligible effect on VT values. The mean absolute test-retest reproducibility for VT was 3-9% across regions. In conclusion, [11C]UCB-J exhibited excellent PET tracer characteristics and has potential as a general purpose tool for measuring synaptic density in neurodegenerative disorders.
Collapse
Affiliation(s)
- Sjoerd J Finnema
- Department of Radiology and Biomedical
Imaging, Yale Positron Emission Tomography Center,
Yale
University, New Haven, CT, USA
| | - Nabeel B Nabulsi
- Department of Radiology and Biomedical
Imaging, Yale Positron Emission Tomography Center,
Yale
University, New Haven, CT, USA
| | | | - Shu-fei Lin
- Department of Radiology and Biomedical
Imaging, Yale Positron Emission Tomography Center,
Yale
University, New Haven, CT, USA
| | - Ming-Kai Chen
- Department of Radiology and Biomedical
Imaging, Yale Positron Emission Tomography Center,
Yale
University, New Haven, CT, USA
| | - David Matuskey
- Department of Radiology and Biomedical
Imaging, Yale Positron Emission Tomography Center,
Yale
University, New Haven, CT, USA
| | - Jean-Dominique Gallezot
- Department of Radiology and Biomedical
Imaging, Yale Positron Emission Tomography Center,
Yale
University, New Haven, CT, USA
| | - Shannan Henry
- Department of Radiology and Biomedical
Imaging, Yale Positron Emission Tomography Center,
Yale
University, New Haven, CT, USA
| | | | - Yiyun Huang
- Department of Radiology and Biomedical
Imaging, Yale Positron Emission Tomography Center,
Yale
University, New Haven, CT, USA
| | - Richard E Carson
- Department of Radiology and Biomedical
Imaging, Yale Positron Emission Tomography Center,
Yale
University, New Haven, CT, USA
- Department of Biomedical Engineering,
Yale
University, New Haven, CT, USA
| |
Collapse
|
169
|
Affiliation(s)
- Elizabeth C. Mormino
- Department of Neurology and Neurological Sciences, Stanford University, Stanford, California
| | - William J. Jagust
- Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley
| |
Collapse
|
170
|
Gendron T, Sander K, Cybulska K, Benhamou L, Sin PKB, Khan A, Wood M, Porter MJ, Årstad E. Ring-Closing Synthesis of Dibenzothiophene Sulfonium Salts and Their Use as Leaving Groups for Aromatic 18F-Fluorination. J Am Chem Soc 2018; 140:11125-11132. [PMID: 30132661 PMCID: PMC6128620 DOI: 10.1021/jacs.8b06730] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Indexed: 01/18/2023]
Abstract
Herein, we report a novel intramolecular ring-closing reaction of biaryl thioethers that give access to highly functionalized dibenzothiophene sulfonium salts under mild conditions. The resulting precursors react regioselectively with [18F]fluoride to give [18F]fluoroarenes in predictable radiochemical yields. The strategy expands the available radiochemical space and provides superior labeling efficiency for clinically relevant PET tracers.
Collapse
Affiliation(s)
- Thibault Gendron
- Institute
of Nuclear Medicine, University College
London, 235 Euston Road (T-5), London NW1 2BU, United Kingdom
- Department
of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, United Kingdom
| | - Kerstin Sander
- Institute
of Nuclear Medicine, University College
London, 235 Euston Road (T-5), London NW1 2BU, United Kingdom
- Department
of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, United Kingdom
| | - Klaudia Cybulska
- Department
of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, United Kingdom
| | - Laure Benhamou
- Institute
of Nuclear Medicine, University College
London, 235 Euston Road (T-5), London NW1 2BU, United Kingdom
- Department
of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, United Kingdom
| | - Pak Kwan Brian Sin
- Institute
of Nuclear Medicine, University College
London, 235 Euston Road (T-5), London NW1 2BU, United Kingdom
- Department
of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, United Kingdom
| | - Aqsa Khan
- Department
of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, United Kingdom
| | - Michael Wood
- Department
of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, United Kingdom
| | - Michael J. Porter
- Department
of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, United Kingdom
| | - Erik Årstad
- Institute
of Nuclear Medicine, University College
London, 235 Euston Road (T-5), London NW1 2BU, United Kingdom
- Department
of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, United Kingdom
| |
Collapse
|
171
|
Stankoff B, Poirion E, Tonietto M, Bodini B. Exploring the heterogeneity of MS lesions using positron emission tomography: a reappraisal of their contribution to disability. Brain Pathol 2018; 28:723-734. [PMID: 30020560 PMCID: PMC8099240 DOI: 10.1111/bpa.12641] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2018] [Accepted: 07/09/2018] [Indexed: 12/22/2022] Open
Abstract
The biological mechanisms driving disability worsening in multiple sclerosis (MS) are only partly understood. Monitoring changes in lesion load on MRI has a limited predictive value on the progression of clinical disability, and there is an essential need for novel imaging markers specific for the main candidate mechanisms underlying neurodegeneration which include failing myelin repair, innate immune cell activation and gray matter neuronal damage. Positron Emission Tomography (PET) is an imaging technology based on the injection of radiotracers directed against specific molecular targets, which has recently allowed the selective quantification in-vivo of the key biological mechanisms relevant to MS pathophysiology. Pilot PET studies performed in patients with all forms of MS allowed to revisit the contribution of MS lesions to disability worsening and showed that the evolution of lesions toward chronic activation, together with their remyelination profile were relevant predictors of disability worsening. PET offers the opportunity to bridge a critical gap between neuropathology and in-vivo imaging. This technique provides an original approach to disentangle some of the most relevant pathological components driving MS progression, to follow-up their temporal evolution, to investigate their clinical relevance and to evaluate novel therapeutics aimed to prevent disease progression.
Collapse
Affiliation(s)
- Bruno Stankoff
- Sorbonne UniversitésUPMC Paris 06Institut du Cerveau et de la Moelle épinièreICMHôpital de la Pitié SalpêtrièreInserm UMR S 1127CNRS UMR 7225ParisFrance
- AP‐HPHôpital Saint‐AntoineParisFrance
| | - Emilie Poirion
- Sorbonne UniversitésUPMC Paris 06Institut du Cerveau et de la Moelle épinièreICMHôpital de la Pitié SalpêtrièreInserm UMR S 1127CNRS UMR 7225ParisFrance
| | - Matteo Tonietto
- Sorbonne UniversitésUPMC Paris 06Institut du Cerveau et de la Moelle épinièreICMHôpital de la Pitié SalpêtrièreInserm UMR S 1127CNRS UMR 7225ParisFrance
| | - Benedetta Bodini
- Sorbonne UniversitésUPMC Paris 06Institut du Cerveau et de la Moelle épinièreICMHôpital de la Pitié SalpêtrièreInserm UMR S 1127CNRS UMR 7225ParisFrance
- AP‐HPHôpital Saint‐AntoineParisFrance
| |
Collapse
|
172
|
Quantifying SV2A density and drug occupancy in the human brain using [11C]UCB-J PET imaging and subcortical white matter as reference tissue. Eur J Nucl Med Mol Imaging 2018; 46:396-406. [DOI: 10.1007/s00259-018-4119-8] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Accepted: 07/30/2018] [Indexed: 11/26/2022]
|
173
|
Bini J, Naganawa M, Nabulsi N, Huang Y, Ropchan J, Lim K, Najafzadeh S, Herold KC, Cline GW, Carson RE. Evaluation of PET Brain Radioligands for Imaging Pancreatic β-Cell Mass: Potential Utility of 11C-(+)-PHNO. J Nucl Med 2018; 59:1249-1254. [PMID: 29371405 DOI: 10.2967/jnumed.117.197285] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Accepted: 12/07/2017] [Indexed: 12/21/2022] Open
Abstract
Type 1 diabetes mellitus (T1DM) is characterized by a loss of β-cells in the islets of Langerhans of the pancreas and subsequent deficient insulin secretion in response to hyperglycemia. Development of an in vivo test to measure β-cell mass (BCM) would greatly enhance the ability to track diabetes therapies. β-cells and neurologic tissues have common cellular receptors and transporters, therefore, we screened brain radioligands for their ability to identify β-cells. Methods: We examined a β-cell gene atlas for endocrine pancreas receptor targets and cross-referenced these targets with brain radioligands that were available at our institution. Twelve healthy control subjects and 2 T1DM subjects underwent dynamic PET/CT scans with 6 tracers. Results: The D2/D3 receptor agonist radioligand 11C-(+)-4-propyl-9-hydroxynaphthoxazine (PHNO) was the only radioligand to demonstrate sustained uptake in the pancreas with high contrast versus abdominal organs such as the kidneys, liver, and spleen, based on the first 30 min of data. Mean SUV from 20 to 30 min demonstrated high uptake of 11C-(+)-PHNO in healthy controls (SUV, 13.8) with a 71% reduction in a T1DM subject with undetectable levels of C-peptide (SUV, 4.0) and a 20% reduction in a T1DM subject with fasting C-peptide level of 0.38 ng/mL (SUV, 11.0). SUV in abdominal organs outside the pancreas did not show measurable differences between the control and T1DM subjects, suggesting that the changes in SUV of 11C-(+)-PHNO may be specific to changes in the pancreas between healthy controls and T1DM subjects. When D3 and D2 antagonists were used in nonhuman primates, specific pancreatic binding (SUVR-1) of 11C-PHNO was reduced by 57% and 38%, respectively. Conclusion:11C-(+)-PHNO is a potential marker of BCM, with 2:1 binding of D3 receptors over D2 receptors. Further in vitro and in vivo studies to establish D2/D3 receptor specificity to β-cells is warranted to characterize 11C-(+)-PHNO as a candidate for clinical measurement of BCM in healthy control and diabetic subjects.
Collapse
Affiliation(s)
- Jason Bini
- PET Center, Yale University School of Medicine, New Haven, CT .,Department of Biomedical Engineering, Yale University, New Haven, CT; and
| | - Mika Naganawa
- PET Center, Yale University School of Medicine, New Haven, CT
| | - Nabeel Nabulsi
- PET Center, Yale University School of Medicine, New Haven, CT
| | - Yiyun Huang
- PET Center, Yale University School of Medicine, New Haven, CT
| | - Jim Ropchan
- PET Center, Yale University School of Medicine, New Haven, CT
| | - Keunpoong Lim
- PET Center, Yale University School of Medicine, New Haven, CT
| | | | - Kevan C Herold
- Department of Immunobiology and Internal Medicine, Yale University School of Medicine, New Haven, CT
| | - Gary W Cline
- Department of Immunobiology and Internal Medicine, Yale University School of Medicine, New Haven, CT
| | - Richard E Carson
- PET Center, Yale University School of Medicine, New Haven, CT.,Department of Biomedical Engineering, Yale University, New Haven, CT; and
| |
Collapse
|
174
|
Henriques AD, Benedet AL, Camargos EF, Rosa-Neto P, Nóbrega OT. Fluid and imaging biomarkers for Alzheimer's disease: Where we stand and where to head to. Exp Gerontol 2018; 107:169-177. [PMID: 29307736 DOI: 10.1016/j.exger.2018.01.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2017] [Revised: 12/29/2017] [Accepted: 01/02/2018] [Indexed: 10/18/2022]
Abstract
There is increasing evidence that a number of potentially informative biomarkers for Alzheimer disease (AD) can improve the accuracy of diagnosing this form of dementia, especially when used as a panel of diagnostic assays and interpreted in the context of neuroimaging and clinical data. Moreover, by combining the power of CSF biomarkers with neuroimaging techniques to visualize Aβ deposits (or neurodegenerative lesions), it might be possible to better identify individuals at greatest risk for developing MCI and converting to AD. The objective of this article was to review recent progress in selected imaging and chemical biomarkers for prediction, early diagnosis and progression of AD. We present our view point of a scenario that places CSF and imaging markers on the verge of general utility based on accuracy levels that already match (or even surpass) current clinical precision.
Collapse
Affiliation(s)
- Adriane Dallanora Henriques
- Medical Centre for the Elderly, University Hospital, University of Brasília (UnB), 70910-900 Brasília, DF, Brazil
| | - Andrea Lessa Benedet
- Translational Neuroimaging Laboratory, Research Centre for Studies in Aging, Douglas Hospital, McGill University, H4H 1R3 Montreal, QC, Canada
| | - Einstein Francisco Camargos
- Medical Centre for the Elderly, University Hospital, University of Brasília (UnB), 70910-900 Brasília, DF, Brazil
| | - Pedro Rosa-Neto
- Translational Neuroimaging Laboratory, Research Centre for Studies in Aging, Douglas Hospital, McGill University, H4H 1R3 Montreal, QC, Canada; Montreal Neurological Institute, H3A 2B4 Montreal, QC, Canada
| | - Otávio Toledo Nóbrega
- Medical Centre for the Elderly, University Hospital, University of Brasília (UnB), 70910-900 Brasília, DF, Brazil.
| |
Collapse
|
175
|
Quantitative PET Imaging in Drug Development: Estimation of Target Occupancy. Bull Math Biol 2017; 81:3508-3541. [PMID: 29230702 DOI: 10.1007/s11538-017-0374-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Accepted: 11/27/2017] [Indexed: 01/13/2023]
Abstract
Positron emission tomography, an imaging tool using radiolabeled tracers in humans and preclinical species, has been widely used in recent years in drug development, particularly in the central nervous system. One important goal of PET in drug development is assessing the occupancy of various molecular targets (e.g., receptors, transporters, enzymes) by exogenous drugs. The current linear mathematical approaches used to determine occupancy using PET imaging experiments are presented. These algorithms use results from multiple regions with different target content in two scans, a baseline (pre-drug) scan and a post-drug scan. New mathematical estimation approaches to determine target occupancy, using maximum likelihood, are presented. A major challenge in these methods is the proper definition of the covariance matrix of the regional binding measures, accounting for different variance of the individual regional measures and their nonzero covariance, factors that have been ignored by conventional methods. The novel methods are compared to standard methods using simulation and real human occupancy data. The simulation data showed the expected reduction in variance and bias using the proper maximum likelihood methods, when the assumptions of the estimation method matched those in simulation. Between-method differences for data from human occupancy studies were less obvious, in part due to small dataset sizes. These maximum likelihood methods form the basis for development of improved PET covariance models, in order to minimize bias and variance in PET occupancy studies.
Collapse
|
176
|
Finnema SJ, Nabulsi NB, Eid T, Detyniecki K, Lin SF, Chen MK, Dhaher R, Matuskey D, Baum E, Holden D, Spencer DD, Mercier J, Hannestad J, Huang Y, Carson RE. Imaging synaptic density in the living human brain. Sci Transl Med 2017; 8:348ra96. [PMID: 27440727 DOI: 10.1126/scitranslmed.aaf6667] [Citation(s) in RCA: 317] [Impact Index Per Article: 45.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Accepted: 06/24/2016] [Indexed: 12/26/2022]
Abstract
Chemical synapses are the predominant neuron-to-neuron contact in the central nervous system. Presynaptic boutons of neurons contain hundreds of vesicles filled with neurotransmitters, the diffusible signaling chemicals. Changes in the number of synapses are associated with numerous brain disorders, including Alzheimer's disease and epilepsy. However, all current approaches for measuring synaptic density in humans require brain tissue from autopsy or surgical resection. We report the use of the synaptic vesicle glycoprotein 2A (SV2A) radioligand [(11)C]UCB-J combined with positron emission tomography (PET) to quantify synaptic density in the living human brain. Validation studies in a baboon confirmed that SV2A is an alternative synaptic density marker to synaptophysin. First-in-human PET studies demonstrated that [(11)C]UCB-J had excellent imaging properties. Finally, we confirmed that PET imaging of SV2A was sensitive to synaptic loss in patients with temporal lobe epilepsy. Thus, [(11)C]UCB-J PET imaging is a promising approach for in vivo quantification of synaptic density with several potential applications in diagnosis and therapeutic monitoring of neurological and psychiatric disorders.
Collapse
Affiliation(s)
- Sjoerd J Finnema
- Yale Positron Emission Tomography Center, Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT 06520, USA.
| | - Nabeel B Nabulsi
- Yale Positron Emission Tomography Center, Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT 06520, USA
| | - Tore Eid
- Department of Laboratory Medicine, Yale University, New Haven, CT 06520, USA
| | - Kamil Detyniecki
- Department of Neurology, Yale University, New Haven, CT 06520, USA
| | - Shu-Fei Lin
- Yale Positron Emission Tomography Center, Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT 06520, USA
| | - Ming-Kai Chen
- Yale Positron Emission Tomography Center, Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT 06520, USA
| | - Roni Dhaher
- Department of Laboratory Medicine, Yale University, New Haven, CT 06520, USA
| | - David Matuskey
- Yale Positron Emission Tomography Center, Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT 06520, USA
| | - Evan Baum
- Yale Positron Emission Tomography Center, Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT 06520, USA
| | - Daniel Holden
- Yale Positron Emission Tomography Center, Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT 06520, USA
| | - Dennis D Spencer
- Department of Neurosurgery, Yale University, New Haven, CT 06520, USA
| | | | | | - Yiyun Huang
- Yale Positron Emission Tomography Center, Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT 06520, USA
| | - Richard E Carson
- Yale Positron Emission Tomography Center, Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT 06520, USA. Department of Biomedical Engineering, Yale University, New Haven, CT 06520, USA
| |
Collapse
|
177
|
Schifani C, Hafizi S, Da Silva T, Watts JJ, Khan MS, Mizrahi R. Using molecular imaging to understand early schizophrenia-related psychosis neurochemistry: a review of human studies. Int Rev Psychiatry 2017; 29:555-566. [PMID: 29219634 PMCID: PMC8011813 DOI: 10.1080/09540261.2017.1396205] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Schizophrenia is a chronic psychiatric disorder generally preceded by a so-called prodromal phase, which is characterized by attenuated psychotic symptoms. Advances in clinical research have enabled prospective identification of those individuals who are at clinical high risk (CHR) for psychosis, with the power to predict psychosis onset within the near future. Changes in several brain neurochemical systems and molecular mechanisms are implicated in the pathophysiology of schizophrenia and the psychosis spectrum, including the dopaminergic, γ-aminobutyric acid (GABA)-ergic, glutamatergic, endocannabinoid, and immunologic (i.e. glial activation) system and other promising future directions such as synaptic density, which are possible to quantify in vivo using positron emission tomography (PET). This paper aims to review in vivo PET studies in the mentioned systems in the early course of psychosis (i.e. CHR and first-episode psychosis (FEP)). The results of reviewed studies are promising; however, the current understanding of the underlying pathology of psychosis is still limited. Importantly, promising efforts involve the development of novel PET radiotracers targeting systems with growing interest in schizophrenia, like the nociceptive system and synaptic density.
Collapse
Affiliation(s)
- Christin Schifani
- Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, ON, Canada
| | - Sina Hafizi
- Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, ON, Canada
| | - Tania Da Silva
- Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, ON, Canada
| | - Jeremy Joseph Watts
- Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, ON, Canada
| | - M. Saad Khan
- Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, ON, Canada
| | - Romina Mizrahi
- Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, ON, Canada
- Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, ON, Canada
| |
Collapse
|
178
|
Mercier J, Provins L, Valade A. Discovery and development of SV2A PET tracers: Potential for imaging synaptic density and clinical applications. DRUG DISCOVERY TODAY. TECHNOLOGIES 2017; 25:45-52. [PMID: 29233267 DOI: 10.1016/j.ddtec.2017.11.003] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Revised: 11/08/2017] [Accepted: 11/09/2017] [Indexed: 10/18/2022]
Abstract
Imaging synaptic density in vivo has promise for numerous research and clinical applications in the diagnosis and treatment monitoring of neurodegenerative and psychiatric diseases. Recent developments in the field of PET, such as SV2A human imaging with the novel tracers UCB-A, UCB-H and UCB-J, may help in realizing this potential and bring significant benefit for the patients suffering from these diseases. This review provides an overview of the most recent progress in the field of SV2A PET imaging, its potential for use as a biomarker of synaptic density and the future development areas.
Collapse
|
179
|
Rabiner EA. Imaging Synaptic Density: A Different Look at Neurologic Diseases. J Nucl Med 2017; 59:380-381. [PMID: 29123011 DOI: 10.2967/jnumed.117.198317] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2017] [Accepted: 10/30/2017] [Indexed: 11/16/2022] Open
Affiliation(s)
- Eugenii A Rabiner
- Imanova Ltd. and Centre for Neuroimaging Sciences, Institute of Psychiatry, Psychology, and Neuroscience, King's College, London, United Kingdom
| |
Collapse
|
180
|
Boscutti G, Huiban M, Passchier J. Use of carbon-11 labelled tool compounds in support of drug development. DRUG DISCOVERY TODAY. TECHNOLOGIES 2017; 25:3-10. [PMID: 29233265 DOI: 10.1016/j.ddtec.2017.11.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2017] [Revised: 11/15/2017] [Accepted: 11/16/2017] [Indexed: 06/07/2023]
Abstract
The pharmaceutical industry is facing key challenges to improve return on R&D investment. Positron emission tomography (PET), by itself or in combination with complementary technologies such as magnetic resonance imaging (MRI), provides a unique opportunity to confirm a candidate's ability to meet the so-called 'three pillars' of drug development. Positive confirmation provides confidence for go/no-go decision making at an early stage of the development process and enables informed clinical progression. Whereas fluorine-18 has probably gained wider use in the community, there are benefits to using carbon-11 given the greater flexibility the use of this isotope permits in adaptive clinical study design. This review explores the scope of available carbon-11 chemistries and provides clinical examples to highlight its value in PET studies in support of drug development.
Collapse
Affiliation(s)
- Giulia Boscutti
- Imanova Ltd., Burlington Danes Building, Imperial College London, Hammersmith Hospital, Du Cane Road, London W12 0NN, UK
| | - Mickael Huiban
- Imanova Ltd., Burlington Danes Building, Imperial College London, Hammersmith Hospital, Du Cane Road, London W12 0NN, UK
| | - Jan Passchier
- Imanova Ltd., Burlington Danes Building, Imperial College London, Hammersmith Hospital, Du Cane Road, London W12 0NN, UK.
| |
Collapse
|
181
|
Becker G, Warnier C, Serrano ME, Bahri MA, Mercier J, Lemaire C, Salmon E, Luxen A, Plenevaux A. Pharmacokinetic Characterization of [ 18F]UCB-H PET Radiopharmaceutical in the Rat Brain. Mol Pharm 2017. [PMID: 28651055 DOI: 10.1021/acs.molpharmaceut.7b00235] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The synaptic vesicle glycoprotein 2A (SV2A), a protein essential to the proper nervous system function, is found in presynaptic vesicles. Thus, SV2A targeting, using dedicated radiotracers combined with positron emission tomography (PET), allows the assessment of synaptic density in the living brain. The first-in-class fluorinated SV2A specific radioligand, [18F]UCB-H, is now available at high activity through an efficient radiosynthesis compliant with current good manufacturing practices (cGMP). We report here a noninvasive method to quantify [18F]UCB-H binding in rat brain with microPET. Validation study in rats confirmed the need of high enantiomeric purity to target SV2A in vivo. We demonstrated the reliability of a population-based input function to quantify SV2A in preclinical microPET setting. Finally, we investigated the in vivo metabolism of [18F]UCB-H and confirmed the negligible amount of radiometabolites in the rat brain. Hence, the in vivo quantification of SV2A using [18F]UCB-H microPET seems a promising tool for the assessment of the synaptic density in the rat brain, and opens the way for longitudinal follow-up in neurodegenerative disease rodent models.
Collapse
Affiliation(s)
- Guillaume Becker
- GIGA Cyclotron Research Centre In Vivo Imaging, University of Liège , 4000 Liège, Belgium
| | - Corentin Warnier
- GIGA Cyclotron Research Centre In Vivo Imaging, University of Liège , 4000 Liège, Belgium
| | - Maria Elisa Serrano
- GIGA Cyclotron Research Centre In Vivo Imaging, University of Liège , 4000 Liège, Belgium
| | - Mohamed Ali Bahri
- GIGA Cyclotron Research Centre In Vivo Imaging, University of Liège , 4000 Liège, Belgium
| | | | - Christian Lemaire
- GIGA Cyclotron Research Centre In Vivo Imaging, University of Liège , 4000 Liège, Belgium
| | - Eric Salmon
- GIGA Cyclotron Research Centre In Vivo Imaging, University of Liège , 4000 Liège, Belgium
| | - André Luxen
- GIGA Cyclotron Research Centre In Vivo Imaging, University of Liège , 4000 Liège, Belgium
| | - Alain Plenevaux
- GIGA Cyclotron Research Centre In Vivo Imaging, University of Liège , 4000 Liège, Belgium
| |
Collapse
|
182
|
Bao W, Jia H, Finnema S, Cai Z, Carson RE, Huang YH. PET Imaging for Early Detection of Alzheimer's Disease: From Pathologic to Physiologic Biomarkers. PET Clin 2017; 12:329-350. [PMID: 28576171 DOI: 10.1016/j.cpet.2017.03.001] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
This article describes the application of various PET imaging agents in the investigation and diagnosis of Alzheimer's disease (AD), including radiotracers for pathologic biomarkers of AD such as β-amyloid deposits and tau protein aggregates, and the neuroinflammation biomarker 18 kDa translocator protein, as well as physiologic biomarkers, such as cholinergic receptors, glucose metabolism, and the synaptic density biomarker synaptic vesicle glycoprotein 2A. Potential of these biomarkers for early AD diagnosis is also assessed.
Collapse
Affiliation(s)
- Weiqi Bao
- PET Center, Huanshan Hospital, Fudan University, No. 518, East Wuzhong Road, Xuhui District, Shanghai 200235, China
| | - Hongmei Jia
- Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry, Beijing Normal University, No. 19, Xinjiekouwai Street, Beijing 10075, China
| | - Sjoerd Finnema
- Department of Radiology and Biomedical Imaging, PET Center, Yale University School of Medicine, PO Box 208048, New Haven, CT 06520-8048, USA
| | - Zhengxin Cai
- Department of Radiology and Biomedical Imaging, PET Center, Yale University School of Medicine, PO Box 208048, New Haven, CT 06520-8048, USA
| | - Richard E Carson
- Department of Radiology and Biomedical Imaging, PET Center, Yale University School of Medicine, PO Box 208048, New Haven, CT 06520-8048, USA
| | - Yiyun Henry Huang
- Department of Radiology and Biomedical Imaging, PET Center, Yale University School of Medicine, PO Box 208048, New Haven, CT 06520-8048, USA.
| |
Collapse
|
183
|
Positron emission tomography in amyotrophic lateral sclerosis: Towards targeting of molecular pathological hallmarks. Eur J Nucl Med Mol Imaging 2016; 44:533-547. [DOI: 10.1007/s00259-016-3587-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2016] [Accepted: 11/23/2016] [Indexed: 12/18/2022]
|
184
|
Löscher W, Gillard M, Sands ZA, Kaminski RM, Klitgaard H. Synaptic Vesicle Glycoprotein 2A Ligands in the Treatment of Epilepsy and Beyond. CNS Drugs 2016; 30:1055-1077. [PMID: 27752944 PMCID: PMC5078162 DOI: 10.1007/s40263-016-0384-x] [Citation(s) in RCA: 100] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The synaptic vesicle glycoprotein SV2A belongs to the major facilitator superfamily (MFS) of transporters and is an integral constituent of synaptic vesicle membranes. SV2A has been demonstrated to be involved in vesicle trafficking and exocytosis, processes crucial for neurotransmission. The anti-seizure drug levetiracetam was the first ligand to target SV2A and displays a broad spectrum of anti-seizure activity in various preclinical models. Several lines of preclinical and clinical evidence, including genetics and protein expression changes, support an important role of SV2A in epilepsy pathophysiology. While the functional consequences of SV2A ligand binding are not fully elucidated, studies suggest that subsequent SV2A conformational changes may contribute to seizure protection. Conversely, the recently discovered negative SV2A modulators, such as UCB0255, counteract the anti-seizure effect of levetiracetam and display procognitive properties in preclinical models. More broadly, dysfunction of SV2A may also be involved in Alzheimer's disease and other types of cognitive impairment, suggesting potential novel therapies for levetiracetam and its congeners. Furthermore, emerging data indicate that there may be important roles for two other SV2 isoforms (SV2B and SV2C) in the pathogenesis of epilepsy, as well as other neurodegenerative diseases. Utilization of recently developed SV2A positron emission tomography ligands will strengthen and reinforce the pharmacological evidence that SV2A is a druggable target, and will provide a better understanding of its role in epilepsy and other neurological diseases, aiding in further defining the full therapeutic potential of SV2A modulation.
Collapse
Affiliation(s)
- Wolfgang Löscher
- Department of Pharmacology, Toxicology and Pharmacy, University of Veterinary Medicine Hannover, Bünteweg 17, 30559, Hannover, Germany.
- Center for Systems Neuroscience, Hannover, Germany.
| | | | | | | | | |
Collapse
|
185
|
Slifstein M, Abi-Dargham A. Recent Developments in Molecular Brain Imaging of Neuropsychiatric Disorders. Semin Nucl Med 2016; 47:54-63. [PMID: 27987558 DOI: 10.1053/j.semnuclmed.2016.09.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Molecular imaging with PET or SPECT has been an important research tool in psychiatry for as long as these modalities have been available. Here, we discuss two areas of neuroimaging relevant to current psychiatry research. The first is the use of imaging to study neurotransmission. We discuss the use of pharmacologic probes to induce changes in levels of neurotransmitters that can be inferred through their effects on outcome measures of imaging experiments, from their historical origins focusing on dopamine transmission through recent developments involving serotonin, GABA, and glutamate. Next, we examine imaging of neuroinflammation in the context of psychiatry. Imaging markers of neuroinflammation have been studied extensively in other areas of brain research, but they have more recently attracted interest in psychiatry research, based on accumulating evidence that there may be an inflammatory component to some psychiatric conditions. Furthermore, new probes are under development that would allow unprecedented insights into cellular processes. In summary, molecular imaging would continue to offer great potential as a unique tool to further our understanding of brain function in health and disease.
Collapse
Affiliation(s)
- Mark Slifstein
- Department of Psychiatry, Columbia University Medical Center, New York, NY; New York State Psychiatric Institute, New York, NY; Department of Psychiatry, Stony Brook University, New York, NY.
| | - Anissa Abi-Dargham
- Department of Psychiatry, Columbia University Medical Center, New York, NY; Department of Radiology, Columbia University Medical Center, New York, NY; New York State Psychiatric Institute, New York, NY; Department of Psychiatry, Stony Brook University, New York, NY
| |
Collapse
|
186
|
Warnier C, Lemaire C, Becker G, Zaragoza G, Giacomelli F, Aerts J, Otabashi M, Bahri MA, Mercier J, Plenevaux A, Luxen A. Enabling Efficient Positron Emission Tomography (PET) Imaging of Synaptic Vesicle Glycoprotein 2A (SV2A) with a Robust and One-Step Radiosynthesis of a Highly Potent 18F-Labeled Ligand ([ 18F]UCB-H). J Med Chem 2016; 59:8955-8966. [PMID: 27598384 DOI: 10.1021/acs.jmedchem.6b00905] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
We herein describe the straightforward synthesis of a stable pyridyl(4-methoxyphenyl)iodonium salt and its [18F] radiolabeling within a one-step, fully automated and cGMP compliant radiosynthesis of [18F]UCB-H ([18F]7), a PET tracer for the imaging of synaptic vesicle glycoprotein 2A (SV2A). Over the course of 1 year, 50 automated productions provided 34 ± 2% of injectable [18F]7 from up to 285 GBq (7.7 Ci) of [18F]fluoride in 50 min (uncorrected radiochemical yield, specific activity of 815 ± 185 GBq/μmol). The successful implementation of our synthetic strategy within routine, high-activity, and cGMP productions attests to its practicality and reliability for the production of large doses of [18F]7. In addition to enabling efficient and cost-effective clinical research on a range of neurological pathologies through the imaging of SV2A, this work further demonstrates the real value of iodonium salts for the cGMP 18F-PET tracer manufacturing industry, and their ability to fulfill practical and regulatory requirements in that field.
Collapse
Affiliation(s)
- Corentin Warnier
- GIGA Cyclotron Research Centre In Vivo Imaging, University of Liege , 4000 Liege, Belgium
| | - Christian Lemaire
- GIGA Cyclotron Research Centre In Vivo Imaging, University of Liege , 4000 Liege, Belgium
| | - Guillaume Becker
- GIGA Cyclotron Research Centre In Vivo Imaging, University of Liege , 4000 Liege, Belgium
| | - Guillermo Zaragoza
- Unidad de RX, Universidade de Santiago de Compostela , 15782 Santiago de Compostela, Spain
| | - Fabrice Giacomelli
- GIGA Cyclotron Research Centre In Vivo Imaging, University of Liege , 4000 Liege, Belgium
| | - Joël Aerts
- GIGA Cyclotron Research Centre In Vivo Imaging, University of Liege , 4000 Liege, Belgium.,INSERM U1148 , 75018 Paris, France
| | | | - Mohamed Ali Bahri
- GIGA Cyclotron Research Centre In Vivo Imaging, University of Liege , 4000 Liege, Belgium
| | | | - Alain Plenevaux
- GIGA Cyclotron Research Centre In Vivo Imaging, University of Liege , 4000 Liege, Belgium
| | - André Luxen
- GIGA Cyclotron Research Centre In Vivo Imaging, University of Liege , 4000 Liege, Belgium
| |
Collapse
|