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Weinstein JJ, Moeller SJ, Perlman G, Gil R, Van Snellenberg JX, Wengler K, Meng J, Slifstein M, Abi-Dargham A. Imaging the Vesicular Acetylcholine Transporter in Schizophrenia: A Positron Emission Tomography Study Using [ 18F]-VAT. Biol Psychiatry 2024; 96:352-364. [PMID: 38309322 DOI: 10.1016/j.biopsych.2024.01.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Revised: 01/10/2024] [Accepted: 01/23/2024] [Indexed: 02/05/2024]
Abstract
BACKGROUND Despite longstanding interest in the central cholinergic system in schizophrenia (SCZ), cholinergic imaging studies with patients have been limited to receptors. Here, we conducted a proof-of-concept positron emission tomography study using [18F]-VAT, a new radiotracer that targets the vesicular acetylcholine transporter as a proxy measure of acetylcholine transmission capacity, in patients with SCZ and explored relationships of vesicular acetylcholine transporter with clinical symptoms and cognition. METHODS A total of 18 adult patients with SCZ or schizoaffective disorder (the SCZ group) and 14 healthy control participants underwent a positron emission tomography scan with [18F]-VAT. Distribution volume (VT) for [18F]-VAT was derived for each region of interest, and group differences in VT were assessed with 2-sample t tests. Functional significance was explored through correlations between VT and scores on the Positive and Negative Syndrome Scale and a computerized neurocognitive battery (PennCNB). RESULTS No group differences in [18F]-VAT VT were observed. However, within the SCZ group, psychosis symptom severity was positively associated with VT in multiple regions of interest, with the strongest effects in the hippocampus, thalamus, midbrain, cerebellum, and cortex. In addition, in the SCZ group, working memory performance was negatively associated with VT in the substantia innominata and several cortical regions of interest including the dorsolateral prefrontal cortex. CONCLUSIONS In this initial study, the severity of 2 important features of SCZ-psychosis and working memory deficit-was strongly associated with [18F]-VAT VT in several cortical and subcortical regions. These correlations provide preliminary evidence of cholinergic activity involvement in SCZ and, if replicated in larger samples, could lead to a more complete mechanistic understanding of psychosis and cognitive deficits in SCZ and the development of therapeutic targets.
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Affiliation(s)
- Jodi J Weinstein
- Department of Psychiatry and Behavioral Health, Stony Brook University Renaissance School of Medicine, Stony Brook, New York; Department of Psychiatry, Columbia University Vagelos School of Medicine and New York State Psychiatric Institute, New York, New York.
| | - Scott J Moeller
- Department of Psychiatry and Behavioral Health, Stony Brook University Renaissance School of Medicine, Stony Brook, New York
| | - Greg Perlman
- Department of Psychiatry and Behavioral Health, Stony Brook University Renaissance School of Medicine, Stony Brook, New York
| | - Roberto Gil
- Department of Psychiatry and Behavioral Health, Stony Brook University Renaissance School of Medicine, Stony Brook, New York
| | - Jared X Van Snellenberg
- Department of Psychiatry and Behavioral Health, Stony Brook University Renaissance School of Medicine, Stony Brook, New York; Department of Biomedical Engineering, Stony Brook University, Stony Brook, New York; Department of Psychology, Stony Brook University, Stony Brook, New York
| | - Kenneth Wengler
- Department of Psychiatry, Columbia University Vagelos School of Medicine and New York State Psychiatric Institute, New York, New York; Department of Radiology, Stony Brook University Renaissance School of Medicine, Stony Brook, New York
| | - Jiayan Meng
- Department of Psychiatry and Behavioral Health, Stony Brook University Renaissance School of Medicine, Stony Brook, New York
| | - Mark Slifstein
- Department of Psychiatry and Behavioral Health, Stony Brook University Renaissance School of Medicine, Stony Brook, New York
| | - Anissa Abi-Dargham
- Department of Psychiatry and Behavioral Health, Stony Brook University Renaissance School of Medicine, Stony Brook, New York; Department of Psychiatry, Columbia University Vagelos School of Medicine and New York State Psychiatric Institute, New York, New York
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O'Donnell JL, Soda AK, Jiang H, Norris SA, Maiti B, Karimi M, Campbell MC, Moerlein SM, Tu Z, Perlmutter JS. PET Quantification of [ 18F]VAT in Human Brain and Its Test-Retest Reproducibility and Age Dependence. J Nucl Med 2024; 65:956-961. [PMID: 38604762 PMCID: PMC11149597 DOI: 10.2967/jnumed.123.266860] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Revised: 03/13/2024] [Indexed: 04/13/2024] Open
Abstract
Molecular imaging of brain vesicular acetylcholine transporter provides a biomarker to explore cholinergic systems in humans. We aimed to characterize the distribution of, and optimize methods to quantify, the vesicular acetylcholine transporter-specific tracer (-)-(1-(8-(2-[18F]fluoroethoxy)-3-hydroxy-1,2,3,4-tetrahydronaphthalen-2-yl)-piperidin-4-yl)(4-fluorophenyl)methanone ([18F]VAT) in the brain using PET. Methods: Fifty-two healthy participants aged 21-97 y had brain PET with [18F]VAT. [3H]VAT autoradiography identified brain areas devoid of specific binding in cortical white matter. PET image-based white matter reference region size, model start time, and duration were optimized for calculations of Logan nondisplaceable binding potential (BPND). Ten participants had 2 scans to determine test-retest variability. Finally, we analyzed age-dependent differences in participants. Results: [18F]VAT was widely distributed in the brain, with high striatal, thalamic, amygdala, hippocampal, cerebellar vermis, and regionally specific uptake in the cerebral cortex. [3H]VAT autoradiography-specific binding and PET [18F]VAT uptake were low in white matter. [18F]VAT SUVs in the white matter reference region correlated with age, requiring stringent erosion parameters. Logan BPND estimates stabilized using at least 40 min of data starting 25 min after injection. Test-retest variability had excellent reproducibility and reliability in repeat BPND calculations for 10 participants (putamen, 6.8%; r > 0.93). We observed age-dependent decreases in the caudate and putamen (multiple comparisons corrected) and in numerous cortical regions. Finally, we provide power tables to indicate potential mean differences that can be detected between 2 groups of participants. Conclusion: These results validate a reference region for BPND calculations and demonstrate the viability, reproducibility, and utility of using the [18F]VAT tracer in humans to quantify cholinergic pathways.
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Affiliation(s)
- John L O'Donnell
- Neurology, Washington University in Saint Louis, St. Louis, Missouri;
| | - Anil Kumar Soda
- Radiology, Washington University in Saint Louis, St. Louis, Missouri
| | - Hao Jiang
- Radiology, Washington University in Saint Louis, St. Louis, Missouri
| | - Scott A Norris
- Neurology, Washington University in Saint Louis, St. Louis, Missouri
- Radiology, Washington University in Saint Louis, St. Louis, Missouri
| | - Baijayanta Maiti
- Neurology, Washington University in Saint Louis, St. Louis, Missouri
- Radiology, Washington University in Saint Louis, St. Louis, Missouri
| | - Morvarid Karimi
- Neurology, Washington University in Saint Louis, St. Louis, Missouri
- Radiology, Washington University in Saint Louis, St. Louis, Missouri
| | - Meghan C Campbell
- Neurology, Washington University in Saint Louis, St. Louis, Missouri
- Radiology, Washington University in Saint Louis, St. Louis, Missouri
| | - Stephen M Moerlein
- Radiology, Washington University in Saint Louis, St. Louis, Missouri
- Biochemistry and Molecular Biophysics, Washington University in Saint Louis, St. Louis, Missouri; and
| | - Zhude Tu
- Radiology, Washington University in Saint Louis, St. Louis, Missouri
| | - Joel S Perlmutter
- Neurology, Washington University in Saint Louis, St. Louis, Missouri
- Radiology, Washington University in Saint Louis, St. Louis, Missouri
- Neuroscience, Physical, and Occupational Therapy, Washington University in Saint Louis, St. Louis, Missouri
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Ananth MR, Gardus JD, Huang C, Palekar N, Slifstein M, Zaborszky L, Parsey RV, Talmage DA, DeLorenzo C, Role LW. Loss of cholinergic input to the entorhinal cortex is an early indicator of cognitive impairment in natural aging of humans and mice. RESEARCH SQUARE 2024:rs.3.rs-3851086. [PMID: 38260541 PMCID: PMC10802688 DOI: 10.21203/rs.3.rs-3851086/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
In a series of translational experiments using fully quantitative positron emission tomography (PET) imaging with a new tracer specific for the vesicular acetylcholine transporter ([18F]VAT) in vivo in humans, and genetically targeted cholinergic markers in mice, we evaluated whether changes to the cholinergic system were an early feature of age-related cognitive decline. We found that deficits in cholinergic innervation of the entorhinal cortex (EC) and decline in performance on behavioral tasks engaging the EC are, strikingly, early features of the aging process. In human studies, we recruited older adult volunteers that were physically healthy and without prior clinical diagnosis of cognitive impairment. Using [18F]VAT PET imaging, we demonstrate that there is measurable loss of cholinergic inputs to the EC that can serve as an early signature of decline in EC cognitive performance. These deficits are specific to the cholinergic circuit between the medial septum and vertical limb of the diagonal band (MS/vDB; CH1/2) to the EC. Using diffusion imaging, we further demonstrate impaired structural connectivity in the tracts between the MS/vDB and EC in older adults with mild cognitive impairment. Experiments in mouse, designed to parallel and extend upon the human studies, used high resolution imaging to evaluate cholinergic terminal density and immediate early gene (IEG) activity of EC neurons in healthy aging mice and in mice with genetic susceptibility to accelerated accumulation amyloid beta plaques and hyperphosphorylated mouse tau. Across species and aging conditions, we find that the integrity of cholinergic projections to the EC directly correlates with the extent of EC activation and with performance on EC-related object recognition memory tasks. Silencing EC-projecting cholinergic neurons in young, healthy mice during the object-location memory task impairs object recognition performance, mimicking aging. Taken together we identify a role for acetylcholine in normal EC function and establish loss of cholinergic input to the EC as an early, conserved feature of age-related cognitive decline in both humans and rodents.
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d’Orchymont F, Narvaez A, Raymond R, Sachdev P, Charil A, Krause S, Vasdev N. In vitro evaluation of PET radiotracers for imaging synaptic density, the acetylcholine transporter, AMPA-tarp-γ8 and muscarinic M4 receptors in Alzheimer's disease. AMERICAN JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING 2024; 14:1-12. [PMID: 38500748 PMCID: PMC10944377] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 10/18/2023] [Accepted: 02/04/2024] [Indexed: 03/20/2024]
Abstract
Several therapeutics and biomarkers that target Alzheimer's disease (AD) are under development. Our clinical positron emission tomography (PET) research programs are interested in six radiopharmaceuticals to image patients with AD and related dementias, specifically [11C]UCB-J and [18F]SynVesT-1 for synaptic vesicle glycoprotein 2A as a marker of synaptic density, two vesicular acetylcholine transporter PET radiotracers: [18F]FEOBV and [18F]VAT, as well as the transmembrane AMPA receptor regulatory protein (TARP)-γ8 tracer, [18F]JNJ-64511070, and the muscarinic acetylcholine receptor (mAChR) M4 tracer [11C]MK-6884. The goal of this study was to compare all six radiotracers (labeled with tritium or 18F) by measuring their density variability in pathologically diagnosed cases of AD, mild cognitive impairment (MCI) and normal healthy volunteer (NHV) human brains, using thin-section in vitro autoradiography (ARG). Region of interest analysis was used to quantify radioligand binding density and determine whether the radioligands provide a signal-to-noise ratio optimal for showing changes in binding. Our preliminary study confirmed that all six radiotracers show specific binding in MCI and AD. An expected decrease in their respective target density in human AD hippocampus tissues compared to NHV was observed with [3H]UCB-J, [3H]SynVesT-1, [3H]JNJ-64511070, and [3H]MK-6884. This preliminary study will be used to guide human PET imaging of SV2A, TARP-γ8 and the mAChR M4 subtype for imaging in AD and related dementias.
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Affiliation(s)
- Faustine d’Orchymont
- Azrieli Centre for Neuro-Radiochemistry, Brain Health Imaging Centre, Centre for Addiction and Mental Health (CAMH)Toronto, ON, Canada
| | - Andrea Narvaez
- Azrieli Centre for Neuro-Radiochemistry, Brain Health Imaging Centre, Centre for Addiction and Mental Health (CAMH)Toronto, ON, Canada
- Enigma Biomedical Group, Inc.Toronto, ON, Canada
| | - Roger Raymond
- Azrieli Centre for Neuro-Radiochemistry, Brain Health Imaging Centre, Centre for Addiction and Mental Health (CAMH)Toronto, ON, Canada
| | | | | | | | - Neil Vasdev
- Azrieli Centre for Neuro-Radiochemistry, Brain Health Imaging Centre, Centre for Addiction and Mental Health (CAMH)Toronto, ON, Canada
- Department of Psychiatry, University of TorontoToronto, ON, Canada
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5
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Zhang S, Qiu Y, Huang L, Bi L, Guo Y, You K, Huang G, Wang Y, Lu H, Jin H, Shan H. Ankylosing spondylitis PET imaging and quantifications via P2X7 receptor-targeting radioligand [ 18F]GSK1482160. Eur J Nucl Med Mol Imaging 2023; 50:3589-3601. [PMID: 37466648 DOI: 10.1007/s00259-023-06342-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Accepted: 07/12/2023] [Indexed: 07/20/2023]
Abstract
PURPOSE Ankylosing spondylitis (AS) is a chronic inflammatory disease of the axial spine; however, the quantitative detection of inflammation in AS remains a challenge in clinical settings. We aimed to investigate the feasibility of using a specific P2X7R-targeting 18F-labeled tracer [18F]GSK1482160 for positron emission tomography (PET) imaging and the quantification of AS. METHODS The radioligand [18F]GSK1482160 was obtained based on nucleophilic aliphatic substitution. Dynamic [18F]GSK1482160 and [18F]FDG micro-PET/CT imaging were performed on AS mice (n = 8) and age-matched controls (n = 8). Tracer kinetics modeling was performed using Logan's graphical arterial input function analysis to quantify the in vivo expression of P2X7R. The post-PET tissues were collected for hematoxylin-eosin (H&E), immunohistochemical (IHC), and immunofluorescence (IF) staining. RESULTS [18F]GSK1482160 PET/CT imaging revealed that the specific binding in the ankle joint and sacroiliac joint (SIJ) of the AS at 8 weeks group (BPNDankle-AS-8W (non-displaceable binding potential of the ankle) 3.931 ± 0.74; BPND SIJ-AS-8W (BPBD of the SIJ) 4.225 ± 0.84) were significantly higher than the controls at 8 weeks group (BPNDankle-Ctr-8W 0.325 ± 0.15, BPNDSJJ-Ctr-8W 0.319 ± 0.17) respectively, and the AS at 14 weeks group (BPNDankle-AS-14W 12.212 ± 2.25; BPNDSJJ-AS-14W 13.389 ± 3.60) were significantly higher than the controls at 14 weeks group (BPNDankle-Ctr-14W 0.204 ± 0.16, BPNDSJJ-Ctr-14W 0.655 ± 0.35) respectively. The four groups had no significant difference in the [18F]FDG uptake of ankle and SIJ. IHC and IF staining revealed that the overexpression of P2X7R was colocalized with activated macrophages from the ankle synovium and spinal endplate in mice with AS, indicating that quantification of P2X7R may contribute to the understanding of the pathogenesis of inflammation in human AS. CONCLUSION This study developed a novel P2X7R-targeting PET tracer [18F]GSK1482160 to detect the expression of P2X7R in AS mouse models and provided powerful non-invasive PET imaging and quantification for AS.
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Affiliation(s)
- Shiyanjin Zhang
- Department of Spine Surgery, Sun Yat-Sen University Fifth Affiliated Hospital, Zhuhai, 519000, Guangdong Province, China
| | - Yifan Qiu
- Guangdong Provincial Engineering Research Center of Molecular Imaging, The Fifth Affiliated Hospital, Sun Yat-Sen University, Zhuhai, 519000, Guangdong Province, China
| | - Lihua Huang
- Department of Spine Surgery, Sun Yat-Sen University Fifth Affiliated Hospital, Zhuhai, 519000, Guangdong Province, China
- Guangdong Provincial Engineering Research Center of Molecular Imaging, The Fifth Affiliated Hospital, Sun Yat-Sen University, Zhuhai, 519000, Guangdong Province, China
| | - Lei Bi
- Guangdong Provincial Engineering Research Center of Molecular Imaging, The Fifth Affiliated Hospital, Sun Yat-Sen University, Zhuhai, 519000, Guangdong Province, China
| | - Yuanqing Guo
- Department of Spine Surgery, Sun Yat-Sen University Fifth Affiliated Hospital, Zhuhai, 519000, Guangdong Province, China
| | - Ke You
- Department of Spine Surgery, Sun Yat-Sen University Fifth Affiliated Hospital, Zhuhai, 519000, Guangdong Province, China
| | - Guolong Huang
- Guangdong Provincial Engineering Research Center of Molecular Imaging, The Fifth Affiliated Hospital, Sun Yat-Sen University, Zhuhai, 519000, Guangdong Province, China
| | - Yuhan Wang
- Department of Spine Surgery, Sun Yat-Sen University Fifth Affiliated Hospital, Zhuhai, 519000, Guangdong Province, China
| | - Hai Lu
- Department of Spine Surgery, Sun Yat-Sen University Fifth Affiliated Hospital, Zhuhai, 519000, Guangdong Province, China.
| | - Hongjun Jin
- Guangdong Provincial Engineering Research Center of Molecular Imaging, The Fifth Affiliated Hospital, Sun Yat-Sen University, Zhuhai, 519000, Guangdong Province, China.
| | - Hong Shan
- Guangdong Provincial Engineering Research Center of Molecular Imaging, The Fifth Affiliated Hospital, Sun Yat-Sen University, Zhuhai, 519000, Guangdong Province, China
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6
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Cools R, Kerkhofs K, Leitao RCF, Bormans G. Preclinical Evaluation of Novel PET Probes for Dementia. Semin Nucl Med 2023; 53:599-629. [PMID: 37149435 DOI: 10.1053/j.semnuclmed.2023.03.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Accepted: 03/24/2023] [Indexed: 05/08/2023]
Abstract
The development of novel PET imaging agents that selectively bind specific dementia-related targets can contribute significantly to accurate, differential and early diagnosis of dementia causing diseases and support the development of therapeutic agents. Consequently, in recent years there has been a growing body of literature describing the development and evaluation of potential new promising PET tracers for dementia. This review article provides a comprehensive overview of novel dementia PET probes under development, classified by their target, and pinpoints their preclinical evaluation pathway, typically involving in silico, in vitro and ex/in vivo evaluation. Specific target-associated challenges and pitfalls, requiring extensive and well-designed preclinical experimental evaluation assays to enable successful clinical translation and avoid shortcomings observed for previously developed 'well-established' dementia PET tracers are highlighted in this review.
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Affiliation(s)
- Romy Cools
- Laboratory for Radiopharmaceutical Research, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium
| | - Kobe Kerkhofs
- Laboratory for Radiopharmaceutical Research, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium; NURA, Belgian Nuclear Research Centre (SCK CEN), Mol, Belgium
| | - Renan C F Leitao
- Laboratory for Radiopharmaceutical Research, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium
| | - Guy Bormans
- Laboratory for Radiopharmaceutical Research, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium.
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7
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Ananth MR, Rajebhosale P, Kim R, Talmage DA, Role LW. Basal forebrain cholinergic signalling: development, connectivity and roles in cognition. Nat Rev Neurosci 2023; 24:233-251. [PMID: 36823458 PMCID: PMC10439770 DOI: 10.1038/s41583-023-00677-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Accepted: 01/18/2023] [Indexed: 02/25/2023]
Abstract
Acetylcholine plays an essential role in fundamental aspects of cognition. Studies that have mapped the activity and functional connectivity of cholinergic neurons have shown that the axons of basal forebrain cholinergic neurons innervate the pallium with far more topographical and functional organization than was historically appreciated. Together with the results of studies using new probes that allow release of acetylcholine to be detected with high spatial and temporal resolution, these findings have implicated cholinergic networks in 'binding' diverse behaviours that contribute to cognition. Here, we review recent findings on the developmental origins, connectivity and function of cholinergic neurons, and explore the participation of cholinergic signalling in the encoding of cognition-related behaviours.
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Affiliation(s)
- Mala R Ananth
- Section on Circuits, Synapses, and Molecular Signalling, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA.
| | - Prithviraj Rajebhosale
- Section on Genetics of Neuronal Signalling, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
| | - Ronald Kim
- Section on Genetics of Neuronal Signalling, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
| | - David A Talmage
- Section on Genetics of Neuronal Signalling, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
| | - Lorna W Role
- Section on Circuits, Synapses, and Molecular Signalling, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA.
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8
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Singh P, Singh D, Srivastava P, Mishra G, Tiwari AK. Evaluation of advanced, pathophysiologic new targets for imaging of CNS. Drug Dev Res 2023; 84:484-513. [PMID: 36779375 DOI: 10.1002/ddr.22040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2022] [Revised: 12/12/2022] [Accepted: 12/31/2022] [Indexed: 02/14/2023]
Abstract
The inadequate information about the in vivo pathological, physiological, and neurological impairments, as well as the absence of in vivo tools for assessing brain penetrance and the efficiency of newly designed drugs, has hampered the development of new techniques for the treatment for variety of new central nervous system (CNS) diseases. The searching sites such as Science Direct and PubMed were used to find out the numerous distinct tracers across 16 CNS targets including tau, synaptic vesicle glycoprotein, the adenosine 2A receptor, the phosphodiesterase enzyme PDE10A, and the purinoceptor, among others. Among the most encouraging are [18 F]FIMX for mGluR imaging, [11 C]Martinostat for Histone deacetylase, [18 F]MNI-444 for adenosine 2A imaging, [11 C]ER176 for translocator protein, and [18 F]MK-6240 for tau imaging. We also reviewed the findings for each tracer's features and potential for application in CNS pathophysiology and therapeutic evaluation investigations, including target specificity, binding efficacy, and pharmacokinetic factors. This review aims to present a current evaluation of modern positron emission tomography tracers for CNS targets, with a focus on recent advances for targets that have newly emerged for imaging in humans.
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Affiliation(s)
- Priya Singh
- Department of Chemistry, Babasaheb Bhimrao Ambedkar University, Lucknow, Uttar Pradesh, India
| | - Deepika Singh
- Department of Chemistry, Babasaheb Bhimrao Ambedkar University, Lucknow, Uttar Pradesh, India
| | - Pooja Srivastava
- Division of Cyclotron and Radiopharmaceuticals Sciences, Institute of Nuclear Medicine and Allied Sciences, Delhi, India
| | - Gauri Mishra
- Department of Zoology, Swami Shraddhananad College, University of Delhi, Alipur, Delhi, India
| | - Anjani K Tiwari
- Department of Chemistry, Babasaheb Bhimrao Ambedkar University, Lucknow, Uttar Pradesh, India
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9
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Wang J, Jin C, Zhou J, Zhou R, Tian M, Lee HJ, Zhang H. PET molecular imaging for pathophysiological visualization in Alzheimer's disease. Eur J Nucl Med Mol Imaging 2023; 50:765-783. [PMID: 36372804 PMCID: PMC9852140 DOI: 10.1007/s00259-022-05999-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Accepted: 10/09/2022] [Indexed: 11/15/2022]
Abstract
Alzheimer's disease (AD) is the most common dementia worldwide. The exact etiology of AD is unclear as yet, and no effective treatments are currently available, making AD a tremendous burden posed on the whole society. As AD is a multifaceted and heterogeneous disease, and most biomarkers are dynamic in the course of AD, a range of biomarkers should be established to evaluate the severity and prognosis. Positron emission tomography (PET) offers a great opportunity to visualize AD from diverse perspectives by using radiolabeled agents involved in various pathophysiological processes; PET imaging technique helps to explore the pathomechanisms of AD comprehensively and find out the most appropriate biomarker in each AD phase, leading to a better evaluation of the disease. In this review, we discuss the application of PET in the course of AD and summarized radiolabeled compounds with favorable imaging characteristics.
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Affiliation(s)
- Jing Wang
- grid.412465.0Department of Nuclear Medicine and PET Center, The Second Affiliated Hospital of Zhejiang University School of Medicine, 88 Jiefang Road, Hangzhou, 310009 Zhejiang China ,grid.13402.340000 0004 1759 700XInstitute of Nuclear Medicine and Molecular Imaging of Zhejiang University, Hangzhou, 310009 Zhejiang China ,Key Laboratory of Medical Molecular Imaging of Zhejiang Province, Hangzhou, 310009 Zhejiang China
| | - Chentao Jin
- grid.412465.0Department of Nuclear Medicine and PET Center, The Second Affiliated Hospital of Zhejiang University School of Medicine, 88 Jiefang Road, Hangzhou, 310009 Zhejiang China
| | - Jinyun Zhou
- grid.412465.0Department of Nuclear Medicine and PET Center, The Second Affiliated Hospital of Zhejiang University School of Medicine, 88 Jiefang Road, Hangzhou, 310009 Zhejiang China
| | - Rui Zhou
- grid.412465.0Department of Nuclear Medicine and PET Center, The Second Affiliated Hospital of Zhejiang University School of Medicine, 88 Jiefang Road, Hangzhou, 310009 Zhejiang China
| | - Mei Tian
- grid.412465.0Department of Nuclear Medicine and PET Center, The Second Affiliated Hospital of Zhejiang University School of Medicine, 88 Jiefang Road, Hangzhou, 310009 Zhejiang China ,grid.13402.340000 0004 1759 700XInstitute of Nuclear Medicine and Molecular Imaging of Zhejiang University, Hangzhou, 310009 Zhejiang China ,Key Laboratory of Medical Molecular Imaging of Zhejiang Province, Hangzhou, 310009 Zhejiang China
| | - Hyeon Jeong Lee
- grid.13402.340000 0004 1759 700XCollege of Biomedical Engineering and Instrument Science, Zhejiang University, Hangzhou, 310014 Zhejiang China
| | - Hong Zhang
- grid.412465.0Department of Nuclear Medicine and PET Center, The Second Affiliated Hospital of Zhejiang University School of Medicine, 88 Jiefang Road, Hangzhou, 310009 Zhejiang China ,grid.13402.340000 0004 1759 700XInstitute of Nuclear Medicine and Molecular Imaging of Zhejiang University, Hangzhou, 310009 Zhejiang China ,Key Laboratory of Medical Molecular Imaging of Zhejiang Province, Hangzhou, 310009 Zhejiang China ,grid.13402.340000 0004 1759 700XCollege of Biomedical Engineering and Instrument Science, Zhejiang University, Hangzhou, 310014 Zhejiang China ,grid.13402.340000 0004 1759 700XKey Laboratory for Biomedical Engineering of Ministry of Education, Zhejiang University, Hangzhou, 310014 Zhejiang China
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10
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Spano M, Roytman M, Aboian M, Saboury B, Franceschi A, Chiang GC. Brain PET Imaging: Approach to Cognitive Impairment and Dementia. PET Clin 2023; 18:103-113. [PMID: 36442959 PMCID: PMC9713600 DOI: 10.1016/j.cpet.2022.09.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Alzheimer disease (AD) is the most common cause of dementia, accounting for 50% to 60% of cases and affecting nearly 6 million people in the United States. Definitive diagnosis requires either antemortem brain biopsy or postmortem autopsy. However, clinical neuroimaging has been playing a greater role in the diagnosis and management of AD, and several PET tracers approach the sensitivity of tissue diagnosis in identifying AD pathologic condition. This review will focus on the utility of PET imaging in the setting of cognitive impairment, with an emphasis on its role in the diagnosis of AD.
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Affiliation(s)
- Matthew Spano
- Department of Radiology, Weill Cornell Medicine, NewYork-Presbyterian Hospital, 525 East 68th Street, Starr Pavilion, Box 141, New York, NY 10065, USA
| | - Michelle Roytman
- Department of Radiology, Weill Cornell Medicine, NewYork-Presbyterian Hospital, 525 East 68th Street, Starr Pavilion, Box 141, New York, NY 10065, USA
| | - Mariam Aboian
- Department of Radiology, Yale School of Medicine, 330 Cedar Street, New Haven, CT 06520, USA
| | - Babak Saboury
- Department of Radiology and Imaging Sciences, NIH Clinical Center, 10 Center Dr, Bethesda, MD 20892, USA
| | - Ana Franceschi
- Department of Radiology, Northwell Health/Donald and Barbara Zucker School of Medicine, Lenox Hill Hospital, 100 East 77th Street, 3rd Floor, New York, NY 10075, USA
| | - Gloria C Chiang
- Department of Radiology, Weill Cornell Medicine, NewYork-Presbyterian Hospital, 525 East 68th Street, Starr Pavilion, Box 141, New York, NY 10065, USA.
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11
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Tiepolt S, Meyer PM, Patt M, Deuther-Conrad W, Hesse S, Barthel H, Sabri O. PET Imaging of Cholinergic Neurotransmission in Neurodegenerative Disorders. J Nucl Med 2022; 63:33S-44S. [PMID: 35649648 DOI: 10.2967/jnumed.121.263198] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 05/06/2022] [Indexed: 12/13/2022] Open
Abstract
As a neuromodulator, the neurotransmitter acetylcholine plays an important role in cognitive, mood, locomotor, sleep/wake, and olfactory functions. In the pathophysiology of most neurodegenerative diseases, such as Alzheimer disease (AD) or Lewy body disorder (LBD), cholinergic receptors, transporters, or enzymes are involved and relevant as imaging targets. The aim of this review is to summarize current knowledge on PET imaging of cholinergic neurotransmission in neurodegenerative diseases. For PET imaging of presynaptic vesicular acetylcholine transporters (VAChT), (-)-18F-fluoroethoxybenzovesamicol (18F-FEOBV) was the first PET ligand that could be successfully translated to clinical application. Since then, the number of 18F-FEOBV PET investigations on patients with AD or LBD has grown rapidly and provided novel, important findings concerning the pathophysiology of AD and LBD. Regarding the α4β2 nicotinic acetylcholine receptors (nAChRs), various second-generation PET ligands, such as 18F-nifene, 18F-AZAN, 18F-XTRA, (-)-18F-flubatine, and (+)-18F-flubatine, were developed and successfully translated to human application. In neurodegenerative diseases such as AD and LBD, PET imaging of α4β2 nAChRs is of special value for monitoring disease progression and drugs directed to α4β2 nAChRs. For PET of α7 nAChR, 18F-ASEM and 11C-MeQAA were successfully applied in mild cognitive impairment and AD, respectively. The highest potential for α7 nAChR PET is seen in staging, in evaluating disease progression, and in therapy monitoring. PET of selective muscarinic acetylcholine receptors (mAChRs) is still in an early stage, as the development of subtype-selective radioligands is complicated. Promising radioligands to image mAChR subtypes M1 (11C-LSN3172176), M2 (18F-FP-TZTP), and M4 (11C-MK-6884) were developed and successfully translated to humans. PET imaging of mAChRs is relevant for the assessment and monitoring of therapies in AD and LBD. PET of acetylcholine esterase activity has been investigated since the 1990s. Many PET studies with 11C-PMP and 11C-MP4A demonstrated cortical cholinergic dysfunction in dementia associated with AD and LBD. Recent studies indicated a solid relationship between subcortical and cortical cholinergic dysfunction and noncognitive dysfunctions such as balance and gait in LBD. Taken together, PET of distinct components of cholinergic neurotransmission is of great interest for diagnosis, disease monitoring, and therapy monitoring and to gain insight into the pathophysiology of different neurodegenerative disorders.
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Affiliation(s)
- Solveig Tiepolt
- Department of Nuclear Medicine, University of Leipzig, Leipzig, Germany; and
| | - Philipp M Meyer
- Department of Nuclear Medicine, University of Leipzig, Leipzig, Germany; and
| | - Marianne Patt
- Department of Nuclear Medicine, University of Leipzig, Leipzig, Germany; and
| | | | - Swen Hesse
- Department of Nuclear Medicine, University of Leipzig, Leipzig, Germany; and
| | - Henryk Barthel
- Department of Nuclear Medicine, University of Leipzig, Leipzig, Germany; and
| | - Osama Sabri
- Department of Nuclear Medicine, University of Leipzig, Leipzig, Germany; and
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12
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Crișan G, Moldovean-Cioroianu NS, Timaru DG, Andrieș G, Căinap C, Chiș V. Radiopharmaceuticals for PET and SPECT Imaging: A Literature Review over the Last Decade. Int J Mol Sci 2022; 23:ijms23095023. [PMID: 35563414 PMCID: PMC9103893 DOI: 10.3390/ijms23095023] [Citation(s) in RCA: 61] [Impact Index Per Article: 30.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2022] [Revised: 04/23/2022] [Accepted: 04/28/2022] [Indexed: 02/04/2023] Open
Abstract
Positron emission tomography (PET) uses radioactive tracers and enables the functional imaging of several metabolic processes, blood flow measurements, regional chemical composition, and/or chemical absorption. Depending on the targeted processes within the living organism, different tracers are used for various medical conditions, such as cancer, particular brain pathologies, cardiac events, and bone lesions, where the most commonly used tracers are radiolabeled with 18F (e.g., [18F]-FDG and NA [18F]). Oxygen-15 isotope is mostly involved in blood flow measurements, whereas a wide array of 11C-based compounds have also been developed for neuronal disorders according to the affected neuroreceptors, prostate cancer, and lung carcinomas. In contrast, the single-photon emission computed tomography (SPECT) technique uses gamma-emitting radioisotopes and can be used to diagnose strokes, seizures, bone illnesses, and infections by gauging the blood flow and radio distribution within tissues and organs. The radioisotopes typically used in SPECT imaging are iodine-123, technetium-99m, xenon-133, thallium-201, and indium-111. This systematic review article aims to clarify and disseminate the available scientific literature focused on PET/SPECT radiotracers and to provide an overview of the conducted research within the past decade, with an additional focus on the novel radiopharmaceuticals developed for medical imaging.
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Affiliation(s)
- George Crișan
- Faculty of Physics, Babeş-Bolyai University, Str. M. Kogălniceanu 1, 400084 Cluj-Napoca, Romania; (G.C.); (N.S.M.-C.); (D.-G.T.)
- Department of Nuclear Medicine, County Clinical Hospital, Clinicilor 3-5, 400006 Cluj-Napoca, Romania;
| | | | - Diana-Gabriela Timaru
- Faculty of Physics, Babeş-Bolyai University, Str. M. Kogălniceanu 1, 400084 Cluj-Napoca, Romania; (G.C.); (N.S.M.-C.); (D.-G.T.)
| | - Gabriel Andrieș
- Department of Nuclear Medicine, County Clinical Hospital, Clinicilor 3-5, 400006 Cluj-Napoca, Romania;
| | - Călin Căinap
- The Oncology Institute “Prof. Dr. Ion Chiricuţă”, Republicii 34-36, 400015 Cluj-Napoca, Romania;
| | - Vasile Chiș
- Faculty of Physics, Babeş-Bolyai University, Str. M. Kogălniceanu 1, 400084 Cluj-Napoca, Romania; (G.C.); (N.S.M.-C.); (D.-G.T.)
- Institute for Research, Development and Innovation in Applied Natural Sciences, Babeș-Bolyai University, Str. Fântânele 30, 400327 Cluj-Napoca, Romania
- Correspondence:
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13
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Albin RL, Kanel P, van Laar T, van der Zee S, Roytman S, Koeppe RA, Scott PJH, Bohnen NI. No Dopamine Agonist Modulation of Brain [ 18F]FEOBV Binding in Parkinson's Disease. Mol Pharm 2022; 19:1176-1182. [PMID: 35289620 PMCID: PMC8983523 DOI: 10.1021/acs.molpharmaceut.1c00961] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The [18F]fluoroethoxybenzovesamicol ([18F]FEOBV) positron emission tomography (PET) ligand targets the vesicular acetylcholine transporter. Recent [18F]FEOBV PET rodent studies suggest that regional brain [18F]FEOBV binding may be modulated by dopamine D2-like receptor agents. We examined associations of regional brain [18F]FEOBV PET binding in Parkinson's disease (PD) subjects without versus with dopamine D2-like receptor agonist drug treatment. PD subjects (n = 108; 84 males, 24 females; mean age 68.0 ± 7.6 [SD] years), mean disease duration of 6.0 ± 4.0 years, and mean Movement Disorder Society-revised Unified PD Rating Scale III 35.5 ± 14.2 completed [18F]FEOBV brain PET imaging. Thirty-eight subjects were taking dopamine D2-like agonists. Vesicular monoamine transporter type 2 [11C]dihydrotetrabenazine (DTBZ) PET was available in a subset of 54 patients. Subjects on dopamine D2-like agonists were younger, had a longer duration of disease, and were taking a higher levodopa equivalent dose (LED) compared to subjects not taking dopamine agonists. A group comparison between subjects with versus without dopamine D2-like agonist use did not yield significant differences in cortical, striatal, thalamic, or cerebellar gray matter [18F]FEOBV binding. Confounder analysis using age, duration of disease, LED, and striatal [11C]DTBZ binding also failed to show significant regional [18F]FEOBV binding differences between these two groups. Chronic D2-like dopamine agonist use in PD subjects is not associated with significant alterations of regional brain [18F]FEOBV binding.
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Affiliation(s)
- Roger L Albin
- Department of Neurology, University of Michigan, Ann Arbor, Michigan 48109, United States.,GRECC & Neurology Service, VAAAHS, Ann Arbor, Michigan 48105, United States.,University of Michigan Udall Center, Ann Arbor, Michigan 48109, United States.,University of Michigan Parkinson's Foundation Research Center of Excellence, Ann Arbor, Michigan 48109, United States
| | - Prabesh Kanel
- University of Michigan Udall Center, Ann Arbor, Michigan 48109, United States.,Department of Radiology, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Teus van Laar
- University of Michigan Udall Center, Ann Arbor, Michigan 48109, United States.,Department of Neurology, University Medical Center Groningen, University of Groningen, 9713 AV Groningen, The Netherlands
| | - Sygrid van der Zee
- University of Michigan Udall Center, Ann Arbor, Michigan 48109, United States.,Department of Neurology, University Medical Center Groningen, University of Groningen, 9713 AV Groningen, The Netherlands
| | - Stiven Roytman
- Department of Radiology, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Robert A Koeppe
- University of Michigan Udall Center, Ann Arbor, Michigan 48109, United States.,Department of Radiology, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Peter J H Scott
- Department of Radiology, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Nicolaas I Bohnen
- Department of Neurology, University of Michigan, Ann Arbor, Michigan 48109, United States.,GRECC & Neurology Service, VAAAHS, Ann Arbor, Michigan 48105, United States.,University of Michigan Udall Center, Ann Arbor, Michigan 48109, United States.,University of Michigan Parkinson's Foundation Research Center of Excellence, Ann Arbor, Michigan 48109, United States.,Department of Radiology, University of Michigan, Ann Arbor, Michigan 48109, United States
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14
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Liang Q, Joshi S, Liu H, Yu Y, Zhao H, Benzinger TLS, Perlmutter JS, Tu Z. In vitro characterization of [ 3H]VAT in cells, animal and human brain tissues for vesicular acetylcholine transporter. Eur J Pharmacol 2021; 911:174556. [PMID: 34627806 PMCID: PMC8605764 DOI: 10.1016/j.ejphar.2021.174556] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2021] [Revised: 09/02/2021] [Accepted: 09/03/2021] [Indexed: 11/23/2022]
Abstract
Vesicular acetylcholine transporter plays a crucial role in the cholinergic system, and its alterations is implicated in several neurodegenerative disorders. We recently developed a PET imaging tracer [18F]VAT to target VAChT in vivo with high affinity and selectivity. Here we report in vitro characterization of [3H]VAT, a tritiated counterpart of [18F]VAT. Using human VAChT-rich cell membrane extracts, a saturated binding curve was obtained for [3H]VAT with Kd = 6.5 nM and Bmax = 22.89 pmol/mg protein. In the [3H]VAT competition-binding assay with a panel of CNS ligands, binding inhibition of [3H]VAT was observed using VAChT ligands, the Ki values ranged from 5.41 to 33.3 nM. No inhibition was detected using a panel of other CNS ligands. In vitro [3H]VAT autoradiography of rat brain sections showed strong signals in the striatum, moderate to high signals in vermis, thalamus, cortex, and hippocampus, and weak signals in cerebellum. Strong [3H]VAT ARG signals were also observed from striatal sections of normal nonhuman primates and human brains. Competitive ARG study with human striatal sections demonstrated strong ARG signals of [3H]VAT in caudate and putamen were blocked significantly by either VAChT ligand TZ659 or (-)-vesamicol, but not by the σ1 receptor ligand Yun-122. ARG study also indicated that signal in the striatal sections from PSP human brains was lower than normal human brains. These data provide solid evidence supporting [18F]VAT as a suitable PET radiotracer for quantitative assessment of VAChT levels in vivo.
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Affiliation(s)
- Qianwa Liang
- Department of Radiology, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Sumit Joshi
- Department of Radiology, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Hui Liu
- Department of Radiology, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Yanbo Yu
- Department of Radiology, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Haiyang Zhao
- Department of Radiology, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Tammie L S Benzinger
- Department of Radiology, Washington University School of Medicine, St. Louis, MO, 63110, USA; Department of Neuroscience, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Joel S Perlmutter
- Department of Radiology, Washington University School of Medicine, St. Louis, MO, 63110, USA; Department of Neuroscience, Washington University School of Medicine, St. Louis, MO, 63110, USA; Department of Neurology, Program in Occupational Therapy, Program in Physical Therapy, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Zhude Tu
- Department of Radiology, Washington University School of Medicine, St. Louis, MO, 63110, USA.
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15
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Liu H, Luo Z, Gu J, Su Y, Flores H, Parsons SM, Zhou Y, Perlmutter JS, Tu Z. The impact of dopamine D 2-like agonist/antagonist on [ 18F]VAT PET measurement of VAChT in the brain of nonhuman primates. Eur J Pharm Sci 2020; 143:105152. [PMID: 31740395 PMCID: PMC6980745 DOI: 10.1016/j.ejps.2019.105152] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Revised: 10/15/2019] [Accepted: 11/14/2019] [Indexed: 01/11/2023]
Abstract
Vesicular acetylcholine transporter (VAChT) is a promising target for a PET measure of cholinergic deficits which contribute to cognitive impairments. Dopamine D2-like agonists and antagonists are frequently used in the elderly and could alter cholinergic function and VAChT level. Therefore, pretreatment with dopamine D2-like drugs may interfere with PET measures using [18F]VAT, a specific VAChT radioligand. Herein, we investigated the impact of dopaminergic D2-like antagonist/agonist on VAChT level in the brain of macaques using [18F]VAT PET. PET imaging studies were carried out on macaques at baseline or pretreatment conditions. For pretreatment, animals were injected using a VAChT inhibitor (-)-vesamicol, a D2-like antagonist (-)-eticlopride, and a D2-like agonist (-)-quinpirole, separately. (-)-Vesamicol was injected at escalating doses of 0.025, 0.05, 0.125, 0.25 and 0.35 mg/kg; (-)-eticlopride was injected at escalating doses of 0.01, 0.10 and 0.30 mg/kg; (-)-quinpirole was injected at escalating doses of 0.20, 0.30, and 0.50 mg/kg. PET data showed [18F]VAT uptake declined in a dose-dependent manner by (-)-vesamicol pretreatment, demonstrating [18F]VAT uptake is sensitive to reflect the availability of VAChT binding sites. Furthermore, (-)-eticlopride increased [18F]VAT striatal uptake in a dose-dependent manner, while (-)-quinpirole decreased its uptake, suggesting striatal VAChT levels can be regulated by D2-like drug administration. Our findings confirmed [18F]VAT offers a reliable tool to in vivo assess the availability of VAChT binding sites. More importantly, PET with [18F]VAT successfully quantified the impact of dopaminergic D2-like drugs on striatal VAChT level, suggesting [18F]VAT has great potential for investigating the interaction between dopaminergic and cholinergic systems in vivo.
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Affiliation(s)
- Hui Liu
- Department of Radiology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Zonghua Luo
- Department of Radiology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Jiwei Gu
- Department of Radiology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Yi Su
- Department of Radiology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Hubert Flores
- Department of Neurology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Stanley M Parsons
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, CA 93106, USA
| | - Yun Zhou
- Department of Radiology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Joel S Perlmutter
- Department of Radiology, Washington University School of Medicine, St. Louis, MO 63110, USA; Department of Neurology, Washington University School of Medicine, St. Louis, MO 63110, USA; Department of Neuroscience, Physical Therapy and Occupational Therapy, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Zhude Tu
- Department of Radiology, Washington University School of Medicine, St. Louis, MO 63110, USA.
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16
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McCluskey SP, Plisson C, Rabiner EA, Howes O. Advances in CNS PET: the state-of-the-art for new imaging targets for pathophysiology and drug development. Eur J Nucl Med Mol Imaging 2020; 47:451-489. [PMID: 31541283 PMCID: PMC6974496 DOI: 10.1007/s00259-019-04488-0] [Citation(s) in RCA: 73] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Accepted: 08/15/2019] [Indexed: 02/07/2023]
Abstract
PURPOSE A limit on developing new treatments for a number of central nervous system (CNS) disorders has been the inadequate understanding of the in vivo pathophysiology underlying neurological and psychiatric disorders and the lack of in vivo tools to determine brain penetrance, target engagement, and relevant molecular activity of novel drugs. Molecular neuroimaging provides the tools to address this. This article aims to provide a state-of-the-art review of new PET tracers for CNS targets, focusing on developments in the last 5 years for targets recently available for in-human imaging. METHODS We provide an overview of the criteria used to evaluate PET tracers. We then used the National Institute of Mental Health Research Priorities list to identify the key CNS targets. We conducted a PubMed search (search period 1st of January 2013 to 31st of December 2018), which yielded 40 new PET tracers across 16 CNS targets which met our selectivity criteria. For each tracer, we summarised the evidence of its properties and potential for use in studies of CNS pathophysiology and drug evaluation, including its target selectivity and affinity, inter and intra-subject variability, and pharmacokinetic parameters. We also consider its potential limitations and missing characterisation data, but not specific applications in drug development. Where multiple tracers were present for a target, we provide a comparison of their properties. RESULTS AND CONCLUSIONS Our review shows that multiple new tracers have been developed for proteinopathy targets, particularly tau, as well as the purinoceptor P2X7, phosphodiesterase enzyme PDE10A, and synaptic vesicle glycoprotein 2A (SV2A), amongst others. Some of the most promising of these include 18F-MK-6240 for tau imaging, 11C-UCB-J for imaging SV2A, 11C-CURB and 11C-MK-3168 for characterisation of fatty acid amide hydrolase, 18F-FIMX for metabotropic glutamate receptor 1, and 18F-MNI-444 for imaging adenosine 2A. Our review also identifies recurrent issues within the field. Many of the tracers discussed lack in vivo blocking data, reducing confidence in selectivity. Additionally, late-stage identification of substantial off-target sites for multiple tracers highlights incomplete pre-clinical characterisation prior to translation, as well as human disease state studies carried out without confirmation of test-retest reproducibility.
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Affiliation(s)
- Stuart P McCluskey
- Invicro LLC, A Konica Minolta Company, Burlington Danes Building, Imperial College London, Hammersmith Hospital, Du Cane Road, London, W12 0NN, UK.
- Psychiatric Imaging Group, MRC London Institute of Medical Sciences, Imperial College London, Hammersmith Hospital, London, UK.
| | - Christophe Plisson
- Invicro LLC, A Konica Minolta Company, Burlington Danes Building, Imperial College London, Hammersmith Hospital, Du Cane Road, London, W12 0NN, UK
| | - Eugenii A Rabiner
- Invicro LLC, A Konica Minolta Company, Burlington Danes Building, Imperial College London, Hammersmith Hospital, Du Cane Road, London, W12 0NN, UK
| | - Oliver Howes
- Psychiatric Imaging Group, MRC London Institute of Medical Sciences, Imperial College London, Hammersmith Hospital, London, UK
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17
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Yue X, Luo Z, Liu H, Kaneshige K, Parsons SM, Perlmutter JS, Tu Z. Radiosynthesis and evaluation of a fluorine-18 labeled radioligand targeting vesicular acetylcholine transporter. Bioorg Med Chem Lett 2018; 28:3425-3430. [PMID: 30274694 DOI: 10.1016/j.bmcl.2018.09.030] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Revised: 09/21/2018] [Accepted: 09/22/2018] [Indexed: 12/28/2022]
Abstract
Vesicular acetylcholine transporter (VAChT) is a reliable biomarker for assessing the loss of cholinergic neurons in the brain that is associated with cognitive impairment of patients. 5-Hydrotetralin compound (±)-5-OH-VAT is potent (Ki = 4.64 ± 0.32 nM) and selective for VAChT (>1800-fold and 398-fold for σ1 and σ2 receptor, respectively) with favorable hydrophilicity (LogD = 1.78), while (-)-5-OH-VAT originally serves as the radiolabeling precursor of (-)-[18F]VAT, a promising VAChT radiotracer with a logD value of 2.56. To evaluate (-)-5-OH-[18F]VAT as a radiotracer for VAChT, we performed in vitro binding assay to determine the potency of the minus enantiomer (-)-5-OH-VAT and plus enantiomer (+)-5-OH-VAT, indicating that (-)-5-OH-VAT is a more potent VAChT enantiomer. Radiosynthesis of (-)-5-OH-[18F]VAT was explored using three strategies. (-)-5-OH-[18F]VAT was achieved with a good yield (24 ± 6%) and high molar activity (∼37 GBq/µmol, at the end of synthesis) using a microwave assisted two-step one-pot procedure that started with di-MOM protected nitro-containing precursor (-)-6. MicroPET studies in the brain of nonhuman primate (NHP) suggest that (-)-5-OH-[18F]VAT readily penetrated the blood brain barrier and specifically accumulated in the VAChT-enriched striatum with improved washout kinetics from striatum compared to [18F]VAT. Nevertheless, the lower target to non-target ratio may limit its use for in vivo measurement of the VAChT level in the brain.
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Affiliation(s)
- Xuyi Yue
- Department of Radiology, Washington University School of Medicine, St Louis, MO 63110, United States
| | - Zonghua Luo
- Department of Radiology, Washington University School of Medicine, St Louis, MO 63110, United States
| | - Hui Liu
- Department of Radiology, Washington University School of Medicine, St Louis, MO 63110, United States
| | - Kota Kaneshige
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, CA 93106, United States
| | - Stanley M Parsons
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, CA 93106, United States
| | - Joel S Perlmutter
- Department of Radiology, Washington University School of Medicine, St Louis, MO 63110, United States; Department of Neurology, Washington University School of Medicine, St Louis, MO 63110, United States
| | - Zhude Tu
- Department of Radiology, Washington University School of Medicine, St Louis, MO 63110, United States.
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18
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Liu H, Jin H, Luo Z, Yue X, Zhang X, Flores H, Su Y, Perlmutter JS, Tu Z. In Vivo Characterization of Two 18F-Labeled PDE10A PET Radioligands in Nonhuman Primate Brains. ACS Chem Neurosci 2018; 9:1066-1073. [PMID: 29400443 PMCID: PMC5955820 DOI: 10.1021/acschemneuro.7b00458] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Positron emission tomography (PET) with phosphodiesterase 10A (PDE10A) specific radioligands provides a noninvasive and quantitative imaging tool to access the expression of this enzyme in vivo under normal and diseased conditions. We recently reported two potent 18F-labeled PDE10A radioligands (18F-TZ19106B and 18F-TZ8110); initial evaluation in rats and nonhuman primates indicated stable metabolic profiles and excellent target-to-nontarget ratio (striatum/cerebellum) for both tracers. Herein, we focused on in vivo characterization of 18F-TZ19106B and 18F-TZ8110 to identify a suitable radioligand for imaging PDE10A in vivo. We directly compared microPET studies of these two radiotracers in adult male Macaca fascicularis nonhuman primates (NHPs). 18F-TZ19106B had higher striatal uptake and tracer retention in NHP brains than 18F-TZ8110, quantified by either standardized uptake values (SUVs) or nondisplaceable binding potential (BPND) estimated using reference-based modeling analysis. Blocking and displacement studies using the PDE10A inhibitor MP-10 indicated the binding of 18F-TZ19106B to PDE10A was specific and reversible. We also demonstrated sensitivity of 18F-TZ19106B binding to varying number of specific binding sites using escalating doses of MP-10 blockade (0.3, 0.5, 1.0, 1.5, and 2.0 mg/kg). Pretreatment with a dopamine D2-like receptor antagonist enhanced the striatal uptake of 18F-TZ19106B. Our results indicate that 18F-TZ19106B is a promising radioligand candidate for imaging PDE10A in vivo and it may be used to determine target engagement of PDE10A inhibitors and serve as a tool to evaluate the effect of novel antipsychotic therapies.
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Affiliation(s)
- Hui Liu
- Department of Radiology, Physical Therapy and Occupational Therapy, Washington University School of Medicine, St. Louis, Missouri 63110, United States
| | - Hongjun Jin
- Department of Radiology, Physical Therapy and Occupational Therapy, Washington University School of Medicine, St. Louis, Missouri 63110, United States
| | - Zonghua Luo
- Department of Radiology, Physical Therapy and Occupational Therapy, Washington University School of Medicine, St. Louis, Missouri 63110, United States
| | - Xuyi Yue
- Department of Radiology, Physical Therapy and Occupational Therapy, Washington University School of Medicine, St. Louis, Missouri 63110, United States
| | - Xiang Zhang
- Department of Radiology, Physical Therapy and Occupational Therapy, Washington University School of Medicine, St. Louis, Missouri 63110, United States
| | - Hubert Flores
- Department of Neurology, Physical Therapy and Occupational Therapy, Washington University School of Medicine, St. Louis, Missouri 63110, United States
| | - Yi Su
- Department of Radiology, Physical Therapy and Occupational Therapy, Washington University School of Medicine, St. Louis, Missouri 63110, United States
| | - Joel S. Perlmutter
- Department of Radiology, Physical Therapy and Occupational Therapy, Washington University School of Medicine, St. Louis, Missouri 63110, United States
- Department of Neurology, Physical Therapy and Occupational Therapy, Washington University School of Medicine, St. Louis, Missouri 63110, United States
- Department of Neuroscience, Physical Therapy and Occupational Therapy, Washington University School of Medicine, St. Louis, Missouri 63110, United States
| | - Zhude Tu
- Department of Radiology, Physical Therapy and Occupational Therapy, Washington University School of Medicine, St. Louis, Missouri 63110, United States
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