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Nag S, Miranda-Azpiazu P, Jia Z, Datta P, Arakawa R, Moein MM, Yang Z, Tu Y, Lemoine L, Ågren H, Nordberg A, Långström B, Halldin C. Development of 11C-Labeled ASEM Analogues for the Detection of Neuronal Nicotinic Acetylcholine Receptors (α7-nAChR). ACS Chem Neurosci 2022; 13:352-362. [PMID: 35020351 PMCID: PMC8815074 DOI: 10.1021/acschemneuro.1c00730] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Accepted: 01/04/2022] [Indexed: 12/31/2022] Open
Abstract
The homo-pentameric alpha 7 receptor is one of the major types of neuronal nicotinic acetylcholine receptors (α7-nAChRs) related to cognition, memory formation, and attention processing. The mapping of α7-nAChRs by PET pulls a lot of attention to realize the mechanism and development of CNS diseases such as AD, PD, and schizophrenia. Several PET radioligands have been explored for the detection of the α7-nAChR. 18F-ASEM is the most functional for in vivo quantification of α7-nAChRs in the human brain. The first aim of this study was to initially use results from in silico and machine learning techniques to prescreen and predict the binding energy and other properties of ASEM analogues and to interpret these properties in terms of atomic structures using 18F-ASEM as a lead structure, and second, to label some selected candidates with carbon-11/hydrogen-3 (11C/3H) and to evaluate the binding properties in vitro and in vivo using the labeled candidates. In silico predictions are obtained from perturbation free-energy calculations preceded by molecular docking, molecular dynamics, and metadynamics simulations. Machine learning techniques have been applied for the BBB and P-gp-binding properties. Six analogues of ASEM were labeled with 11C, and three of them were additionally labeled with 3H. Binding properties were further evaluated using autoradiography (ARG) and PET measurements in non-human primates (NHPs). Radiometabolites were measured in NHP plasma. All six compounds were successfully synthesized. Evaluation with ARG showed that 11C-Kln83 was preferably binding to the α7-nAChR. Competition studies showed that 80% of the total binding was displaced. Further ARG studies using 3H-KIn-83 replicated the preliminary results. In the NHP PET study, the distribution pattern of 11C-KIn-83 was similar to other α7 nAChR PET tracers. The brain uptake was relatively low and increased by the administration of tariquidar, indicating a substrate of P-gp. The ASEM blocking study showed that 11C-KIn-83 specifically binds to α7 nAChRs. Preliminary in vitro evaluation of KIn-83 by ARG with both 11C and 3H and in vivo evaluation in NHP showed favorable properties for selectively imaging α7-nAChRs, despite a relatively low brain uptake.
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Affiliation(s)
- Sangram Nag
- Department
of Clinical Neuroscience, Centre for Psychiatry Research, Karolinska Institutet and Stockholm County Council, 171 76 Stockholm, Sweden
| | - Patricia Miranda-Azpiazu
- Department
of Clinical Neuroscience, Centre for Psychiatry Research, Karolinska Institutet and Stockholm County Council, 171 76 Stockholm, Sweden
| | - Zhisheng Jia
- Department
of Clinical Neuroscience, Centre for Psychiatry Research, Karolinska Institutet and Stockholm County Council, 171 76 Stockholm, Sweden
| | - Prodip Datta
- Department
of Clinical Neuroscience, Centre for Psychiatry Research, Karolinska Institutet and Stockholm County Council, 171 76 Stockholm, Sweden
| | - Ryosuke Arakawa
- Department
of Clinical Neuroscience, Centre for Psychiatry Research, Karolinska Institutet and Stockholm County Council, 171 76 Stockholm, Sweden
| | - Mohammad Mahdi Moein
- Department
of Clinical Neuroscience, Centre for Psychiatry Research, Karolinska Institutet and Stockholm County Council, 171 76 Stockholm, Sweden
| | - Zhou Yang
- Department
of Physics and Astronomy, Uppsala University, 751 20 Uppsala, Sweden
| | - Yaoquan Tu
- Division
of Theoretical Chemistry and Biology, Royal
Institute of Technology (KTH), 11428 Stockholm, Sweden
| | - Laetitia Lemoine
- Department
of Neurobiology, Care Sciences and Society, Karolinska Institutet, 141 52 Stockholm Sweden
| | - Hans Ågren
- Department
of Physics and Astronomy, Uppsala University, 751 20 Uppsala, Sweden
| | - Agneta Nordberg
- Department
of Neurobiology, Care Sciences and Society, Karolinska Institutet, 141 52 Stockholm Sweden
- Theme Aging, Karolinska University
Hospital, 141 52 Stockholm, Sweden
| | - Bengt Långström
- Department
of Chemistry, Uppsala University, 75123 Uppsala, Sweden
| | - Christer Halldin
- Department
of Clinical Neuroscience, Centre for Psychiatry Research, Karolinska Institutet and Stockholm County Council, 171 76 Stockholm, Sweden
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Zhou Y, Li J, Nordberg A, Ågren H. Dissecting the Binding Profile of PET Tracers to Corticobasal Degeneration Tau Fibrils. ACS Chem Neurosci 2021; 12:3487-3496. [PMID: 34464084 PMCID: PMC8447187 DOI: 10.1021/acschemneuro.1c00536] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
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Alzheimer’s
disease and primary tauopathies are characterized
by the presence of tau pathology in brain. Several tau positron emission
tomography (PET) tracers have been developed and studied in Alzheimer’s
disease (AD), but there is still a lack of 4R-tau specific tracers
for non-AD tauopathies. We here present the first computational study
on the binding profiles of four tau different PET tracers, PI2620,
CBD2115, PM-PBB3, and MK6240, to corticobasal degeneration (CBD) tau.
The in silico results showed different preferences
for the various binding sites on the 4R fibril, and especially an
entry site, a concave site, and a core site showed high binding affinity
to these tracers. The core site and entry site both showed higher
binding affinity than the surface sites, but the tracers were less
likely to enter these sites. PI2620, CBD2115, and PM-PBB3 all showed
higher binding affinities to CBD tau than the 3R/4R tracer MK6240.
The same strategy has also been applied to AD tau fibrils, and significant
differences in selectivity of binding sites were also observed. A
higher binding affinity was observed for CBD2115 and PM-PBB3 to AD
tau compared to PI2620. None of the studied tracers showed a selectivity
for 4R compared to 3R/4R tau. This study clearly shows that identified
binding sites from cryo-EM with low resolution can be further refined
by metadynamics simulations in order to provide atomic resolution
of the binding modes as well as of the thermodynamic properties.
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Affiliation(s)
- Yang Zhou
- Department of Physics and Astronomy, Uppsala University, Box 516, SE-751 20 Uppsala, Sweden
| | - Junhao Li
- Department of Physics and Astronomy, Uppsala University, Box 516, SE-751 20 Uppsala, Sweden
| | - Agneta Nordberg
- Division of Clinical Geriatrics, Center for Alzheimer Research, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, 141 84, Stockholm, Sweden
- Theme Aging Karolinska University Hospital, S-141 86 Stockholm, Sweden
| | - Hans Ågren
- Department of Physics and Astronomy, Uppsala University, Box 516, SE-751 20 Uppsala, Sweden
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Zhou Y, Kuang G, Li J, Halldin C, Nordberg A, Långström B, Tu Y, Ågren H. In silico studies of ASEM analogues targeting α7-nAChR and experimental verification. RSC Adv 2021; 11:3942-3951. [PMID: 35747361 PMCID: PMC9134020 DOI: 10.1039/d0ra10435c] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Accepted: 01/11/2021] [Indexed: 01/05/2023] Open
Abstract
The α7 nicotinic acetylcholine receptor (α7-nAChR) is implicated in a variety of neurodegenerative and neuropsychiatric disorders, such as Alzheimer's disease (AD) and schizophrenia. The progress of these disorders can be studied using positron emission tomography (PET) with radiotracers for α7-nAChR. [18F]ASEM and [18F] para-ASEM (also referred to as [18F]DBT-10) are novel and potent α7-nAChR PET radiotracers which have successfully been used in human subjects and nonhuman primates, though further improvement of them is still a pressing task in the community of neurodegeneration research. In this work, we demonstrate the use of modern in silico techniques to predict the binding modes, binding strengths, and residence times for molecular PET tracers binding to proteins, using ASEM and DBT-10 as a showcase of the predictive and interpretational power of such techniques, in particular free energy perturbation theory. The corresponding compounds were synthesized and further tested by in vitro binding experiment for validation. Encouragingly, our in silico modeling can correctly predict the binding affinities of the ASEM analogues. The structure-activity relationships for the ortho- and para-substitutions are well explained at the atomistic level and provide structure-based guiding for the future development of PET tracers for α7-nAChR. A discussion is presented on the complementary use of in silico rational methods based on atomic and electronic principles for in vitro characterization of PET tracers.
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Affiliation(s)
- Yang Zhou
- School of Pharmacy, Jinan University Guangzhou 510632 China
- Department of Physics and Astronomy, Uppsala University Box 516 SE-751 20 Uppsala Sweden
| | - Guanglin Kuang
- Division of Theoretical Chemistry and Biology, School of Biotechnology, Royal Institute of Technology (KTH), AlbaNova University Center S-106 91 Stockholm Sweden
| | - Junhao Li
- Division of Theoretical Chemistry and Biology, School of Biotechnology, Royal Institute of Technology (KTH), AlbaNova University Center S-106 91 Stockholm Sweden
| | - Christer Halldin
- Karolinska Institutet, Department of Clinical Neuroscience, Centre for Psychiatric Research 171 76 Stockholm Sweden
| | - Agneta Nordberg
- Nordberg Translational Molecular Imaging Lab, Division of Clinical Geriatrics, Center for Alzheimer Research, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet 141 84 Stockholm Sweden
- Theme Aging Karolinska University Hospital S-141 86 Stockholm Sweden
| | - Bengt Långström
- Department of Chemistry, Uppsala University SE- 751 23 Uppsala Sweden
| | - Yaoquan Tu
- Division of Theoretical Chemistry and Biology, School of Biotechnology, Royal Institute of Technology (KTH), AlbaNova University Center S-106 91 Stockholm Sweden
| | - Hans Ågren
- Department of Physics and Astronomy, Uppsala University Box 516 SE-751 20 Uppsala Sweden
- College of Chemistry and Chemical Engineering, Henan University Kaifeng Henan 475004 P.R. China
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Zhou Y, Zou R, Kuang G, Långström B, Halldin C, Ågren H, Tu Y. Enhanced Sampling Simulations of Ligand Unbinding Kinetics Controlled by Protein Conformational Changes. J Chem Inf Model 2019; 59:3910-3918. [DOI: 10.1021/acs.jcim.9b00523] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Yang Zhou
- Department of Theoretical Chemistry and Biology, KTH Royal Institute of Technology, AlbaNova University Center, Stockholm 10691, Sweden
| | - Rongfeng Zou
- Department of Theoretical Chemistry and Biology, KTH Royal Institute of Technology, AlbaNova University Center, Stockholm 10691, Sweden
| | - Guanglin Kuang
- Department of Theoretical Chemistry and Biology, KTH Royal Institute of Technology, AlbaNova University Center, Stockholm 10691, Sweden
| | - Bengt Långström
- Department of Chemistry, Uppsala University, Uppsala 75123, Sweden
| | - Christer Halldin
- Department of Clinical Neuroscience, Center for Psychiatric Research, Karolinska Institutet and Stockholm County Council, Stockholm 17176, Sweden
| | - Hans Ågren
- Department of Theoretical Chemistry and Biology, KTH Royal Institute of Technology, AlbaNova University Center, Stockholm 10691, Sweden
- College of Chemistry and Chemical Engineering, Henan University, Kaifeng, Henan 475004, P. R. China
| | - Yaoquan Tu
- Department of Theoretical Chemistry and Biology, KTH Royal Institute of Technology, AlbaNova University Center, Stockholm 10691, Sweden
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