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Xiao L, Xiang S, Chen C, Zhu H, Zhou M, Tang Y, Feng L, Hu S. Association of synaptic density and cognitive performance in temporal lobe epilepsy: Humans and animals PET imaging study with [ 18F]SynVesT-1. Psychiatry Clin Neurosci 2024. [PMID: 38804583 DOI: 10.1111/pcn.13682] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Revised: 04/08/2024] [Accepted: 05/03/2024] [Indexed: 05/29/2024]
Abstract
AIM Cognitive impairment is a common comorbidity in individuals with temporal lobe epilepsy (TLE), yet the underlying mechanisms remain unknown. This study explored the putative association between in vivo synaptic loss and cognitive outcomes in TLE patients by PET imaging of synaptic vesicle glycoprotein 2A (SV2A). METHODS We enrolled 16 TLE patients and 10 cognitively normal controls. All participants underwent SV2A PET imaging using [18F]SynVesT-1 and cognitive assessment. Lithium chloride-pilocarpine-induced rats with status epilepticus (n = 20) and controls (n = 6) rats received levetiracetam (LEV, specifically binds to SV2A), valproic acid (VPA), or saline for 14 days. Then, synaptic density was quantified by [18F]SynVesT-1 micro-PET/CT. The novel object recognition and Morris water maze tests evaluated TLE-related cognitive function. SV2A expression was examined and confirmed by immunohistochemistry. RESULTS Temporal lobe epilepsy patients showed significantly reduced synaptic density in hippocampus, which was associated with cognitive performance. In the rat model of TLE, the expression of SV2A and synaptic density decreased consistently in a wider range of brain regions, including the entorhinal cortex, insula, hippocampus, amygdala, thalamus, and cortex. We treated TLE animal models with LEV or VPA to explore whether synaptic loss contributes to cognitive deficits. It was found that LEV significantly exerted protective effects against brain synaptic deficits and cognitive impairment. CONCLUSION This is the first study to link synaptic loss to cognitive deficits in TLE, suggesting [18F]SynVesT-1 PET could be a promising biomarker for monitoring synaptic loss and cognitive dysfunction. LEV might help reverse synaptic deficits and ameliorate learning and memory impairments in TLE patients.
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Affiliation(s)
- Ling Xiao
- Department of Nuclear Medicine, Xiangya Hospital, Central South University, Changsha, China
| | - Shijun Xiang
- Department of Nuclear Medicine, Xiangya Hospital, Central South University, Changsha, China
| | - Chen Chen
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China
| | - Haoyue Zhu
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Ming Zhou
- Department of Nuclear Medicine, Xiangya Hospital, Central South University, Changsha, China
| | - Yongxiang Tang
- Department of Nuclear Medicine, Xiangya Hospital, Central South University, Changsha, China
- National Clinical Research Center for Geriatric Diseases, Xiangya Hospital, Central South University, Changsha, China
| | - Li Feng
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
- National Clinical Research Center for Geriatric Diseases, Xiangya Hospital, Central South University, Changsha, China
| | - Shuo Hu
- Department of Nuclear Medicine, Xiangya Hospital, Central South University, Changsha, China
- National Clinical Research Center for Geriatric Diseases, Xiangya Hospital, Central South University, Changsha, China
- Key Laboratory of Biological Nanotechnology of National Health Commission, Xiangya Hospital, Central South University, Changsha, China
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Li J, Zou R, Varrone A, Nag S, Halldin C, Ågren H. Exploring the Interactions between two Ligands, UCB-J and UCB-F, and Synaptic Vesicle Glycoprotein 2 Isoforms. ACS Chem Neurosci 2024; 15:2018-2027. [PMID: 38701380 PMCID: PMC11099911 DOI: 10.1021/acschemneuro.4c00029] [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: 01/13/2024] [Revised: 04/14/2024] [Accepted: 04/15/2024] [Indexed: 05/05/2024] Open
Abstract
In silico modeling was applied to study the efficiency of two ligands, namely, UCB-J and UCB-F, to bind to isoforms of the synaptic vesicle glycoprotein 2 (SV2) that are involved in the regulation of synaptic function in the nerve terminals, with the ultimate goal to understand the selectivity of the interaction between UCB-J and UCB-F to different isoforms of SV2. Docking and large-scale molecular dynamics simulations were carried out to unravel various binding patterns, types of interactions, and binding free energies, covering hydrogen bonding and nonspecific hydrophobic interactions, water bridge, π-π, and cation-π interactions. The overall preference for bonding types of UCB-J and UCB-F with particular residues in the protein pockets can be disclosed in detail. A unique interaction fingerprint, namely, hydrogen bonding with additional cation-π interaction with the pyridine moiety of UCB-J, could be established as an explanation for its high selectivity over the SV2 isoform A (SV2A). Other molecular details, primarily referring to the presence of π-π interactions and hydrogen bonding, could also be analyzed as sources of selectivity of the UCB-F tracer for the three isoforms. The simulations provide atomic details to support future development of new selective tracers targeting synaptic vesicle glycoproteins and their associated diseases.
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Affiliation(s)
- Junhao Li
- Department
of Physics and Astronomy, Uppsala University, Box 516, Uppsala SE-751 20, Sweden
| | - Rongfeng Zou
- Department
of Physics and Astronomy, Uppsala University, Box 516, Uppsala SE-751 20, Sweden
| | - Andrea Varrone
- Department
of Clinical Neuroscience, Centre for Psychiatry Research, Karolinska Institutet and Stockholm Health Care Services, Stockholm 171 77, Sweden
| | - Sangram Nag
- Department
of Clinical Neuroscience, Centre for Psychiatry Research, Karolinska Institutet and Stockholm Health Care Services, Stockholm 171 77, Sweden
| | - Christer Halldin
- Department
of Clinical Neuroscience, Centre for Psychiatry Research, Karolinska Institutet and Stockholm Health Care Services, Stockholm 171 77, Sweden
| | - Hans Ågren
- Department
of Physics and Astronomy, Uppsala University, Box 516, Uppsala SE-751 20, Sweden
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He K, Li B, Wang J, Wang Y, You Z, Chen X, Chen H, Li J, Huang Q, Guo Q, Huang YH, Guan Y, Chen K, Zhao J, Deng Y, Xie F. APOE ε4 is associated with decreased synaptic density in cognitively impaired participants. Alzheimers Dement 2024; 20:3157-3166. [PMID: 38477490 PMCID: PMC11095422 DOI: 10.1002/alz.13775] [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: 09/30/2023] [Revised: 02/03/2024] [Accepted: 02/07/2024] [Indexed: 03/14/2024]
Abstract
INTRODUCTION We aimed to investigate the effect of apolipoprotein E4 (APOE) ε4 on synaptic density in cognitively impaired (CI) participants. METHODS One hundred ten CI participants underwent amyloid positron emission tomography (PET) with 18F-florbetapir and synaptic density PET with 18F-SynVesT-1. We evaluated the influence of APOE ε4 allele on synaptic density and investigated the effects of ε4 genotype on the associations of synaptic density with Alzheimer's disease (AD) biomarkers. The mediation effects of AD biomarkers on ε4-associated synaptic density loss were analyzed. RESULTS Compared with non-carriers, APOE ε4 allele carriers exhibited significant synaptic loss in the medial temporal lobe. Amyloid beta (Aβ) and tau pathology mediated the effects of APOE ε4 on synaptic density to different extents. The associations between synaptic density and tau pathology were regulated by the APOE ε4 genotype. DISCUSSION The APOE ε4 allele was associated with decreased synaptic density in CI individuals and may be driven by AD biomarkers.
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Affiliation(s)
- Kun He
- Department of Nuclear Medicine & PET CenterHuashan Hospital, Fudan UniversityShanghaiChina
| | - Binyin Li
- Department of Neurology & Institute of Neurology, Ruijin HospitalShanghai Jiao Tong University School of MedicineShanghaiChina
- Clinical Neuroscience CenterRuijin Hospital LuWan BranchShanghai Jiao Tong University School of MedicineShanghaiChina
| | - Jie Wang
- Department of Nuclear Medicine & PET CenterHuashan Hospital, Fudan UniversityShanghaiChina
| | - Ying Wang
- Department of GerontologyShanghai Jiaotong University Affiliated Sixth People's HospitalShanghaiChina
| | - Zhiwen You
- Department of Nuclear MedicineShanghai East HospitalTongji University School of MedicineShanghaiChina
| | - Xing Chen
- Department of Nuclear MedicineShanghai East HospitalTongji University School of MedicineShanghaiChina
| | - Haijuan Chen
- Department of Neurology & Institute of Neurology, Ruijin HospitalShanghai Jiao Tong University School of MedicineShanghaiChina
| | - Junpeng Li
- Department of Nuclear Medicine & PET CenterHuashan Hospital, Fudan UniversityShanghaiChina
| | - Qi Huang
- Department of Nuclear Medicine & PET CenterHuashan Hospital, Fudan UniversityShanghaiChina
| | - Qihao Guo
- Department of GerontologyShanghai Jiaotong University Affiliated Sixth People's HospitalShanghaiChina
| | - Yiyun Henry Huang
- PET CenterDepartment of Radiology and Biomedical ImagingYale University School of MedicineNew HavenUSA
| | - Yihui Guan
- Department of Nuclear Medicine & PET CenterHuashan Hospital, Fudan UniversityShanghaiChina
| | - Kewei Chen
- Banner Alzheimer InstituteArizona State University, University of Arizona and Arizona Alzheimer's ConsortiumPhoenixUSA
| | - Jun Zhao
- Department of Nuclear MedicineShanghai East HospitalTongji University School of MedicineShanghaiChina
| | - Yulei Deng
- Department of Neurology & Institute of Neurology, Ruijin HospitalShanghai Jiao Tong University School of MedicineShanghaiChina
- Clinical Neuroscience CenterRuijin Hospital LuWan BranchShanghai Jiao Tong University School of MedicineShanghaiChina
| | - Fang Xie
- Department of Nuclear Medicine & PET CenterHuashan Hospital, Fudan UniversityShanghaiChina
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain ScienceFudan UniversityShanghaiChina
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Melrose J. Keratan sulfate, an electrosensory neurosentient bioresponsive cell instructive glycosaminoglycan. Glycobiology 2024; 34:cwae014. [PMID: 38376199 PMCID: PMC10987296 DOI: 10.1093/glycob/cwae014] [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: 01/18/2024] [Revised: 02/12/2024] [Accepted: 02/13/2024] [Indexed: 02/21/2024] Open
Abstract
The roles of keratan sulfate (KS) as a proton detection glycosaminoglycan in neurosensory processes in the central and peripheral nervous systems is reviewed. The functional properties of the KS-proteoglycans aggrecan, phosphacan, podocalyxcin as components of perineuronal nets in neurosensory processes in neuronal plasticity, cognitive learning and memory are also discussed. KS-glycoconjugate neurosensory gels used in electrolocation in elasmobranch fish species and KS substituted mucin like conjugates in some tissue contexts in mammals need to be considered in sensory signalling. Parallels are drawn between KS's roles in elasmobranch fish neurosensory processes and its roles in mammalian electro mechanical transduction of acoustic liquid displacement signals in the cochlea by the tectorial membrane and stereocilia of sensory inner and outer hair cells into neural signals for sound interpretation. The sophisticated structural and functional proteins which maintain the unique high precision physical properties of stereocilia in the detection, transmittance and interpretation of acoustic signals in the hearing process are important. The maintenance of the material properties of stereocilia are essential in sound transmission processes. Specific, emerging roles for low sulfation KS in sensory bioregulation are contrasted with the properties of high charge density KS isoforms. Some speculations are made on how the molecular and electrical properties of KS may be of potential application in futuristic nanoelectronic, memristor technology in advanced ultrafast computing devices with low energy requirements in nanomachines, nanobots or molecular switches which could be potentially useful in artificial synapse development. Application of KS in such innovative areas in bioregulation are eagerly awaited.
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Affiliation(s)
- James Melrose
- Graduate School of Biomedical Engineering, University of New South Wales, Sydney, NSW 2052, Australia
- Raymond Purves Laboratory, Institute of Bone and Joint Research, Kolling Institute of Medical Research, Northern Sydney Local Health District, Royal North Shore Hospital, St. Leonards, NSW 2065, Australia
- Sydney Medical School, Northern, University of Sydney at Royal North Shore Hospital, St. Leonards, NSW 2065, Australia
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5
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Rossi R, Bærentzen SL, Thomsen MB, Real CC, Wegener G, Grassi-Oliveira R, Gjedde A, Landau AM. A single dose of cocaine raises SV2A density in hippocampus of adolescent rats. Acta Neuropsychiatr 2024; 36:109-117. [PMID: 36847240 DOI: 10.1017/neu.2023.14] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 03/01/2023]
Abstract
OBJECTIVE Cocaine is a highly addictive psychostimulant that affects synaptic activity with structural and functional adaptations of neurons. The transmembrane synaptic vesicle glycoprotein 2A (SV2A) of pre-synaptic vesicles is commonly used to measure synaptic density, as a novel approach to the detection of synaptic changes. We do not know if a single dose of cocaine suffices to affect pre-synaptic SV2A density, especially during adolescence when synapses undergo intense maturation. Here, we explored potential changes of pre-synaptic SV2A density in target brain areas associated with the cocaine-induced boost of dopaminergic neurotransmission, specifically testing if the effects would last after the return of dopamine levels to baseline. METHODS We administered cocaine (20 mg/kg i.p.) or saline to rats in early adolescence, tested their activity levels and removed the brains 1 hour and 7 days after injection. To evaluate immediate and lasting effects, we did autoradiography with [3H]UCB-J, a specific tracer for SV2A, in medial prefrontal cortex, striatum, nucleus accumbens, amygdala, and dorsal and ventral areas of hippocampus. We also measured the striatal binding of [3H]GBR-12935 to test cocaine's occupancy of the dopamine transporter at both times of study. RESULTS We found a significant increase of [3H]UCB-J binding in the dorsal and ventral sections of hippocampus 7 days after the cocaine administration compared to saline-injected rats, but no differences 1 hour after the injection. The [3H]GBR-12935 binding remained unchanged at both times. CONCLUSION Cocaine provoked lasting changes of hippocampal synaptic SV2A density after a single exposure during adolescence.
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Affiliation(s)
- Rachele Rossi
- Translational Neuropsychiatry Unit, Department of Clinical Medicine, Aarhus University, Denmark
- Department of Nuclear Medicine and PET Center, Aarhus University Hospital, Aarhus, Denmark
| | - Simone Larsen Bærentzen
- Translational Neuropsychiatry Unit, Department of Clinical Medicine, Aarhus University, Denmark
- Department of Nuclear Medicine and PET Center, Aarhus University Hospital, Aarhus, Denmark
| | - Majken B Thomsen
- Translational Neuropsychiatry Unit, Department of Clinical Medicine, Aarhus University, Denmark
- Department of Nuclear Medicine and PET Center, Aarhus University Hospital, Aarhus, Denmark
| | - Caroline C Real
- Translational Neuropsychiatry Unit, Department of Clinical Medicine, Aarhus University, Denmark
- Department of Nuclear Medicine and PET Center, Aarhus University Hospital, Aarhus, Denmark
| | - Gregers Wegener
- Translational Neuropsychiatry Unit, Department of Clinical Medicine, Aarhus University, Denmark
| | - Rodrigo Grassi-Oliveira
- Translational Neuropsychiatry Unit, Department of Clinical Medicine, Aarhus University, Denmark
| | - Albert Gjedde
- Translational Neuropsychiatry Unit, Department of Clinical Medicine, Aarhus University, Denmark
- Department of Neuroscience, University of Copenhagen, Denmark
- Department of Neurology and Neurosurgery, McGill University, Montreal, Canada
| | - Anne M Landau
- Translational Neuropsychiatry Unit, Department of Clinical Medicine, Aarhus University, Denmark
- Department of Nuclear Medicine and PET Center, Aarhus University Hospital, Aarhus, Denmark
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6
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Martin SL, Uribe C, Strafella AP. PET imaging of synaptic density in Parkinsonian disorders. J Neurosci Res 2024; 102:e25253. [PMID: 37814917 DOI: 10.1002/jnr.25253] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Revised: 08/31/2023] [Accepted: 09/21/2023] [Indexed: 10/11/2023]
Abstract
Synaptic dysfunction and altered synaptic pruning are present in people with Parkinsonian disorders. Dopamine loss and alpha-synuclein accumulation, two hallmarks of Parkinson's disease (PD) pathology, contribute to synaptic dysfunction and reduced synaptic density in PD. Atypical Parkinsonian disorders are likely to have unique spatiotemporal patterns of synaptic density, differentiating them from PD. Therefore, quantification of synaptic density has the potential to support diagnoses, monitor disease progression, and treatment efficacy. Novel radiotracers for positron emission tomography which target the presynaptic vesicle protein SV2A have been developed to quantify presynaptic density. The radiotracers have successfully investigated synaptic density in preclinical models of PD and people with Parkinsonian disorders. Therefore, this review will summarize the preclinical and clinical utilization of SV2A radiotracers in people with Parkinsonian disorders. We will evaluate how SV2A abundance is associated with other imaging modalities and the considerations for interpreting SV2A in Parkinsonian pathology.
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Affiliation(s)
- Sarah L Martin
- Brain Health Imaging Centre, Centre for Addiction and Mental Health, Toronto, Ontario, Canada
| | - Carme Uribe
- Brain Health Imaging Centre, Centre for Addiction and Mental Health, Toronto, Ontario, Canada
- Unitat de Psicologia Medica, Departament de Medicina, Institute of Neuroscience, Universitat de Barcelona, Barcelona, Spain
| | - Antonio P Strafella
- Brain Health Imaging Centre, Centre for Addiction and Mental Health, Toronto, Ontario, Canada
- Edmond J. Safra Parkinson Disease Program, Neurology Division, Toronto Western Hospital & Krembil Brain Institute, University Health Network, University of Toronto, Toronto, Ontario, Canada
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7
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van Dyck CH, Mecca AP, O'Dell RS, Bartlett HH, Diepenbrock NG, Huang Y, Hamby ME, Grundman M, Catalano SM, Caggiano AO, Carson RE. A pilot study to evaluate the effect of CT1812 treatment on synaptic density and other biomarkers in Alzheimer's disease. Alzheimers Res Ther 2024; 16:20. [PMID: 38273408 PMCID: PMC10809445 DOI: 10.1186/s13195-024-01382-2] [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: 08/04/2023] [Accepted: 01/01/2024] [Indexed: 01/27/2024]
Abstract
BACKGROUND Effective, disease-modifying therapeutics for the treatment of Alzheimer's disease (AD) remain a large unmet need. Extensive evidence suggests that amyloid beta (Aβ) is central to AD pathophysiology, and Aβ oligomers are among the most toxic forms of Aβ. CT1812 is a novel brain penetrant sigma-2 receptor ligand that interferes with the binding of Aβ oligomers to neurons. Preclinical studies of CT1812 have demonstrated its ability to displace Aβ oligomers from neurons, restore synapses in cell cultures, and improve cognitive measures in mouse models of AD. CT1812 was found to be generally safe and well tolerated in a placebo-controlled phase 1 clinical trial in healthy volunteers and phase 1a/2 clinical trials in patients with mild to moderate dementia due to AD. The unique objective of this study was to incorporate synaptic positron emission tomography (PET) imaging as an outcome measure for CT1812 in AD patients. METHODS The present phase 1/2 study was a randomized, double-blind, placebo-controlled, parallel-group trial conducted in 23 participants with mild to moderate dementia due to AD to primarily evaluate the safety of CT1812 and secondarily its pharmacodynamic effects. Participants received either placebo or 100 mg or 300 mg per day of oral CT1812 for 24 weeks. Pharmacodynamic effects were assessed using the exploratory efficacy endpoints synaptic vesicle glycoprotein 2A (SV2A) PET, fluorodeoxyglucose (FDG) PET, volumetric MRI, cognitive clinical measures, as well as cerebrospinal fluid (CSF) biomarkers of AD pathology and synaptic degeneration. RESULTS No treatment differences relative to placebo were observed in the change from baseline at 24 weeks in either SV2A or FDG PET signal, the cognitive clinical rating scales, or in CSF biomarkers. Composite region volumetric MRI revealed a trend towards tissue preservation in participants treated with either dose of CT1812, and nominally significant differences with both doses of CT1812 compared to placebo were found in the pericentral, prefrontal, and hippocampal cortices. CT1812 was safe and well tolerated. CONCLUSIONS The safety findings of this 24-week study and the observed changes on volumetric MRI with CT1812 support its further clinical development. TRIAL REGISTRATION The clinical trial described in this manuscript is registered at clinicaltrials.gov (NCT03493282).
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Affiliation(s)
- Christopher H van Dyck
- Alzheimer's Disease Research Unit, Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA.
| | - Adam P Mecca
- Alzheimer's Disease Research Unit, Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
| | - Ryan S O'Dell
- Alzheimer's Disease Research Unit, Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
| | - Hugh H Bartlett
- Alzheimer's Disease Research Unit, Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
| | - Nina G Diepenbrock
- Alzheimer's Disease Research Unit, Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
| | - Yiyun Huang
- Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT, USA
| | - Mary E Hamby
- Cognition Therapeutics Inc., Pittsburgh, PA, USA
| | - Michael Grundman
- Global R&D Partners, LLC, San Diego, CA, USA
- Department of Neurosciences, University of California, San Diego, USA
| | | | | | - Richard E Carson
- Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT, USA
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8
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Silva-Rudberg JA, Salardini E, O'Dell RS, Chen MK, Ra J, Georgelos JK, Morehouse MR, Melino KP, Varma P, Toyonaga T, Nabulsi NB, Huang Y, Carson RE, van Dyck CH, Mecca AP. Assessment of Gray Matter Microstructure and Synaptic Density in Alzheimer's Disease: A Multimodal Imaging Study With DTI and SV2A PET. Am J Geriatr Psychiatry 2024; 32:17-28. [PMID: 37673749 PMCID: PMC10840732 DOI: 10.1016/j.jagp.2023.08.002] [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: 05/25/2023] [Revised: 07/19/2023] [Accepted: 08/05/2023] [Indexed: 09/08/2023]
Abstract
OBJECTIVE Multimodal imaging techniques have furthered our understanding of how different aspects of Alzheimer's disease (AD) pathology relate to one another. Diffusion tensor imaging (DTI) measures such as mean diffusivity (MD) may be a surrogate measure of the changes in gray matter structure associated with AD. Positron emission tomography (PET) imaging of synaptic vesicle glycoprotein 2A (SV2A) has been used to quantify synaptic loss, which is the major pathological correlate of cognitive impairment in AD. In this study, we investigated the relationship between gray matter microstructure and synaptic density. METHODS DTI was used to measure MD and [11C]UCB-J PET to measure synaptic density in 33 amyloid-positive participants with AD and 17 amyloid-negative cognitively normal (CN) participants aged 50-83. Univariate regression analyses were used to assess the association between synaptic density and MD in both the AD and CN groups. RESULTS Hippocampal MD was inversely associated with hippocampal synaptic density in participants with AD (r = -0.55, p <0.001, df = 31) but not CN (r = 0.13, p = 0.62, df = 15). Exploratory analyses across other regions known to be affected in AD suggested widespread inverse associations between synaptic density and MD in the AD group. CONCLUSION In the setting of AD, an increase in gray matter MD is inversely associated with synaptic density. These co-occurring changes may suggest a link between synaptic loss and gray matter microstructural changes in AD. Imaging studies of gray matter microstructure and synaptic density may allow important insights into AD-related neuropathology.
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Affiliation(s)
- Jason A Silva-Rudberg
- Alzheimer's Disease Research Unit (JAS-R, ES, RSO, JR, JKG, MRM, KPM, CHvD, APM), Yale University School of Medicine, New Haven, CT; Department of Psychiatry (JAS-R, ES, RSO, JR, JKG, MRM, KPM, CHvD, APM), Yale University School of Medicine, New Haven, CT.
| | - Elaheh Salardini
- Alzheimer's Disease Research Unit (JAS-R, ES, RSO, JR, JKG, MRM, KPM, CHvD, APM), Yale University School of Medicine, New Haven, CT; Department of Psychiatry (JAS-R, ES, RSO, JR, JKG, MRM, KPM, CHvD, APM), Yale University School of Medicine, New Haven, CT
| | - Ryan S O'Dell
- Alzheimer's Disease Research Unit (JAS-R, ES, RSO, JR, JKG, MRM, KPM, CHvD, APM), Yale University School of Medicine, New Haven, CT; Department of Psychiatry (JAS-R, ES, RSO, JR, JKG, MRM, KPM, CHvD, APM), Yale University School of Medicine, New Haven, CT
| | - Ming-Kai Chen
- Department of Radiology and Biomedical Imaging (M-KC, PV, TT, NBN, YH, REC), Yale University School of Medicine, New Haven, CT
| | - Jocelyn Ra
- Alzheimer's Disease Research Unit (JAS-R, ES, RSO, JR, JKG, MRM, KPM, CHvD, APM), Yale University School of Medicine, New Haven, CT; Department of Psychiatry (JAS-R, ES, RSO, JR, JKG, MRM, KPM, CHvD, APM), Yale University School of Medicine, New Haven, CT
| | - Jamie K Georgelos
- Alzheimer's Disease Research Unit (JAS-R, ES, RSO, JR, JKG, MRM, KPM, CHvD, APM), Yale University School of Medicine, New Haven, CT; Department of Psychiatry (JAS-R, ES, RSO, JR, JKG, MRM, KPM, CHvD, APM), Yale University School of Medicine, New Haven, CT
| | - Mackenzie R Morehouse
- Alzheimer's Disease Research Unit (JAS-R, ES, RSO, JR, JKG, MRM, KPM, CHvD, APM), Yale University School of Medicine, New Haven, CT; Department of Psychiatry (JAS-R, ES, RSO, JR, JKG, MRM, KPM, CHvD, APM), Yale University School of Medicine, New Haven, CT
| | - Kaitlyn P Melino
- Alzheimer's Disease Research Unit (JAS-R, ES, RSO, JR, JKG, MRM, KPM, CHvD, APM), Yale University School of Medicine, New Haven, CT; Department of Psychiatry (JAS-R, ES, RSO, JR, JKG, MRM, KPM, CHvD, APM), Yale University School of Medicine, New Haven, CT
| | - Pradeep Varma
- Department of Radiology and Biomedical Imaging (M-KC, PV, TT, NBN, YH, REC), Yale University School of Medicine, New Haven, CT
| | - Takuya Toyonaga
- Department of Radiology and Biomedical Imaging (M-KC, PV, TT, NBN, YH, REC), Yale University School of Medicine, New Haven, CT
| | - Nabeel B Nabulsi
- Department of Radiology and Biomedical Imaging (M-KC, PV, TT, NBN, YH, REC), Yale University School of Medicine, New Haven, CT
| | - Yiyun Huang
- Department of Radiology and Biomedical Imaging (M-KC, PV, TT, NBN, YH, REC), Yale University School of Medicine, New Haven, CT
| | - Richard E Carson
- Department of Radiology and Biomedical Imaging (M-KC, PV, TT, NBN, YH, REC), Yale University School of Medicine, New Haven, CT
| | - Christopher H van Dyck
- Alzheimer's Disease Research Unit (JAS-R, ES, RSO, JR, JKG, MRM, KPM, CHvD, APM), Yale University School of Medicine, New Haven, CT; Department of Psychiatry (JAS-R, ES, RSO, JR, JKG, MRM, KPM, CHvD, APM), Yale University School of Medicine, New Haven, CT; Department of Neuroscience (CHvD), Yale University School of Medicine, New Haven, CT; Department of Neurology (CHvD), Yale University School of Medicine, New Haven, CT
| | - Adam P Mecca
- Alzheimer's Disease Research Unit (JAS-R, ES, RSO, JR, JKG, MRM, KPM, CHvD, APM), Yale University School of Medicine, New Haven, CT; Department of Psychiatry (JAS-R, ES, RSO, JR, JKG, MRM, KPM, CHvD, APM), Yale University School of Medicine, New Haven, CT.
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9
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Zhang J, Wang J, Xu X, You Z, Huang Q, Huang Y, Guo Q, Guan Y, Zhao J, Liu J, Xu W, Deng Y, Xie F, Li B. In vivo synaptic density loss correlates with impaired functional and related structural connectivity in Alzheimer's disease. J Cereb Blood Flow Metab 2023; 43:977-988. [PMID: 36718002 PMCID: PMC10196742 DOI: 10.1177/0271678x231153730] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/17/2022] [Revised: 12/29/2022] [Accepted: 01/02/2023] [Indexed: 02/01/2023]
Abstract
Synapse loss has been considered as a major pathological change in Alzheimer's disease (AD). It remains unclear about whether and how synapse loss relates to functional and structural connectivity dysfunction in AD. We measured synaptic vesicle glycoprotein 2 A (SV2A) binding using 18F-SynVesT-1 PET to evaluate synaptic alterations in 33 participants with AD, 31 with mild cognitive impairment (MCI), and 30 controls. We examined the correlation between synaptic density and cognitive function. Functional MRI was performed to analyze functional connectivity in lower synaptic density regions. We tracked the white matter tracts between impaired functional connectivity regions using Diffusion MRI. In AD group, lower synaptic density in bilateral cortex and hippocampus was found when compared with controls. The synaptic density changes in right insular cortex and bilateral caudal middle frontal gyrus (MFG) were correlated with cognitive decline. Among them, right MFG synaptic density was positively associated with right MFG - bilateral superior frontal gyrus (SFG) functional connectivity. AD had lower probability of tract (POT) between right MFG and SFG than controls, which was significantly associated with global cognition. These findings provide evidence supporting synapse loss contributes to functional and related structural connectivity alterations underlying cognitive impairment of AD.
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Affiliation(s)
- Junfang Zhang
- Department of Neurology and
Institute of Neurology, Ruijin Hospital, Shanghai Jiao Tong University School of
Medicine, Shanghai, China
| | - Jie Wang
- Department of Nuclear Medicine
& PET Center, Huashan Hospital, Fudan University, Shanghai, China
| | - Xiaomeng Xu
- Department of Neurology and
Institute of Neurology, Ruijin Hospital, Shanghai Jiao Tong University School of
Medicine, Shanghai, China
| | - Zhiwen You
- Department of Nuclear Medicine,
Shanghai East Hospital, Tongji University School of Medicine, Shanghai,
China
| | - Qi Huang
- Department of Nuclear Medicine
& PET Center, Huashan Hospital, Fudan University, Shanghai, China
| | - Yiyun Huang
- PET Center, Department of Radiology
and Biomedical Imaging, Yale University School of Medicine, New Haven,
Connecticut, USA
| | - Qihao Guo
- Department of Gerontology, Shanghai
Jiao Tong University Affiliated Sixth People’s Hospital, Shanghai, China
| | - Yihui Guan
- Department of Nuclear Medicine
& PET Center, Huashan Hospital, Fudan University, Shanghai, China
| | - Jun Zhao
- Department of Nuclear Medicine,
Shanghai East Hospital, Tongji University School of Medicine, Shanghai,
China
| | - Jun Liu
- Department of Neurology and
Institute of Neurology, Ruijin Hospital, Shanghai Jiao Tong University School of
Medicine, Shanghai, China
- Clinical Neuroscience Center,
Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai,
China
| | - Wei Xu
- Department of Neurology and
Institute of Neurology, Ruijin Hospital, Shanghai Jiao Tong University School of
Medicine, Shanghai, China
| | - Yulei Deng
- Department of Neurology and
Institute of Neurology, Ruijin Hospital, Shanghai Jiao Tong University School of
Medicine, Shanghai, China
- Clinical Neuroscience Center,
Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai,
China
- Department of Neurology, Ruijin
Hospital LuWan Branch, Shanghai Jiao Tong University School of Medicine,
Shanghai, China
| | - Fang Xie
- Department of Nuclear Medicine
& PET Center, Huashan Hospital, Fudan University, Shanghai, China
| | - Binyin Li
- Department of Neurology and
Institute of Neurology, Ruijin Hospital, Shanghai Jiao Tong University School of
Medicine, Shanghai, China
- Clinical Neuroscience Center,
Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai,
China
- Department of Neurology, Ruijin
Hospital LuWan Branch, Shanghai Jiao Tong University School of Medicine,
Shanghai, China
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10
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Mecca AP, O'Dell RS, Sharp ES, Banks ER, Bartlett HH, Zhao W, Lipior S, Diepenbrock NG, Chen M, Naganawa M, Toyonaga T, Nabulsi NB, Vander Wyk BC, Arnsten AFT, Huang Y, Carson RE, van Dyck CH. Synaptic density and cognitive performance in Alzheimer's disease: A PET imaging study with [ 11 C]UCB-J. Alzheimers Dement 2022; 18:2527-2536. [PMID: 35174954 PMCID: PMC9381645 DOI: 10.1002/alz.12582] [Citation(s) in RCA: 51] [Impact Index Per Article: 25.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Revised: 11/23/2021] [Accepted: 12/12/2021] [Indexed: 01/31/2023]
Abstract
INTRODUCTION For 30 years synapse loss has been referred to as the major pathological correlate of cognitive impairment in Alzheimer's disease (AD). However, this statement is based on remarkably few patients studied by autopsy or biopsy. With the recent advent of synaptic vesicle glycoprotein 2A (SV2A) positron emission tomography (PET) imaging, we have begun to evaluate the consequences of synaptic alterations in vivo. METHODS We examined the relationship between synaptic density measured by [11 C]UCB-J PET and neuropsychological test performance in 45 participants with early AD. RESULTS Global synaptic density showed a significant positive association with global cognition and performance on five individual cognitive domains in participants with early AD. Synaptic density was a stronger predictor of cognitive performance than gray matter volume. CONCLUSION These results confirm neuropathologic studies demonstrating a significant association between synaptic density and cognitive performance, and suggest that this correlation extends to the early stages of AD.
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Affiliation(s)
- Adam P. Mecca
- Alzheimer's Disease Research UnitYale University School of MedicineNew HavenConnecticutUSA
- Department of PsychiatryYale University School of MedicineNew HavenConnecticutUSA
| | - Ryan S. O'Dell
- Alzheimer's Disease Research UnitYale University School of MedicineNew HavenConnecticutUSA
- Department of PsychiatryYale University School of MedicineNew HavenConnecticutUSA
| | - Emily S. Sharp
- Alzheimer's Disease Research UnitYale University School of MedicineNew HavenConnecticutUSA
- Department of NeurologyYale University School of MedicineNew HavenConnecticutUSA
| | - Emmie R. Banks
- Alzheimer's Disease Research UnitYale University School of MedicineNew HavenConnecticutUSA
- Department of PsychiatryYale University School of MedicineNew HavenConnecticutUSA
| | - Hugh H. Bartlett
- Alzheimer's Disease Research UnitYale University School of MedicineNew HavenConnecticutUSA
- Department of PsychiatryYale University School of MedicineNew HavenConnecticutUSA
| | - Wenzhen Zhao
- Alzheimer's Disease Research UnitYale University School of MedicineNew HavenConnecticutUSA
- Department of PsychiatryYale University School of MedicineNew HavenConnecticutUSA
| | - Sylwia Lipior
- Alzheimer's Disease Research UnitYale University School of MedicineNew HavenConnecticutUSA
- Department of PsychiatryYale University School of MedicineNew HavenConnecticutUSA
| | - Nina G. Diepenbrock
- Alzheimer's Disease Research UnitYale University School of MedicineNew HavenConnecticutUSA
- Department of PsychiatryYale University School of MedicineNew HavenConnecticutUSA
| | - Ming‐Kai Chen
- Department of Radiology and Biomedical ImagingYale University School of MedicineNew HavenConnecticutUSA
| | - Mika Naganawa
- Department of Radiology and Biomedical ImagingYale University School of MedicineNew HavenConnecticutUSA
| | - Takuya Toyonaga
- Department of Radiology and Biomedical ImagingYale University School of MedicineNew HavenConnecticutUSA
| | - Nabeel B. Nabulsi
- Department of Radiology and Biomedical ImagingYale University School of MedicineNew HavenConnecticutUSA
| | | | - Amy F. T. Arnsten
- Alzheimer's Disease Research UnitYale University School of MedicineNew HavenConnecticutUSA
- Department of NeuroscienceYale University School of MedicineNew HavenConnecticutUSA
| | - Yiyun Huang
- Program on AgingYale University School of MedicineNew HavenConnecticutUSA
| | - Richard E. Carson
- Program on AgingYale University School of MedicineNew HavenConnecticutUSA
| | - Christopher H. van Dyck
- Alzheimer's Disease Research UnitYale University School of MedicineNew HavenConnecticutUSA
- Department of PsychiatryYale University School of MedicineNew HavenConnecticutUSA
- Department of NeurologyYale University School of MedicineNew HavenConnecticutUSA
- Department of NeuroscienceYale University School of MedicineNew HavenConnecticutUSA
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11
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Bertoglio D, Zajicek F, Lombaerde SD, Miranda A, Stroobants S, Wang Y, Dominguez C, Munoz-Sanjuan I, Bard J, Liu L, Verhaeghe J, Staelens S. Validation, kinetic modeling, and test-retest reproducibility of [ 18F]SynVesT-1 for PET imaging of synaptic vesicle glycoprotein 2A in mice. J Cereb Blood Flow Metab 2022; 42:1867-1878. [PMID: 35570828 PMCID: PMC9536120 DOI: 10.1177/0271678x221101648] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Alterations in synaptic vesicle glycoprotein 2 A (SV2A) have been associated with several neuropsychiatric and neurodegenerative disorders. Therefore, SV2A positron emission tomography (PET) imaging may provide a unique tool to investigate synaptic density dynamics during disease progression and after therapeutic intervention. This study aims to extensively characterize the novel radioligand [18F]SynVesT-1 for preclinical applications. In C57Bl/6J mice (n = 39), we assessed the plasma profile of [18F]SynVesT-1, validated the use of a noninvasive image-derived input function (IDIF) compared to an arterial input function (AIF), performed a blocking study with levetiracetam (50 and 200 mg/kg, i.p.) to verify the specificity towards SV2A, examined kinetic models for volume of distribution (VT) quantification, and explored test-retest reproducibility of [18F]SynVesT-1 in the central nervous system (CNS). Plasma availability of [18F]SynVesT-1 decreased rapidly (13.4 ± 1.5% at 30 min post-injection). VT based on AIF and IDIF showed excellent agreement (r2 = 0.95, p < 0.0001) and could be reliably estimated with a 60-min acquisition. The blocking study resulted in a complete blockade with no suitable reference region. Test-retest analysis indicated good reproducibility (mean absolute variability <10%). In conclusion, [18F]SynVesT-1 is selective for SV2A with optimal kinetics representing a candidate tool to quantify CNS synaptic density non-invasively.
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Affiliation(s)
- Daniele Bertoglio
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Antwerp, Belgium
| | - Franziska Zajicek
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Antwerp, Belgium
| | - Stef De Lombaerde
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Antwerp, Belgium.,Department of Nuclear Medicine, Antwerp University Hospital, Edegem, Belgium
| | - Alan Miranda
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Antwerp, Belgium
| | - Sigrid Stroobants
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Antwerp, Belgium.,Department of Nuclear Medicine, Antwerp University Hospital, Edegem, Belgium
| | - Yuchuan Wang
- CHDI Management/CHDI Foundation, Los Angeles, California, USA
| | - Celia Dominguez
- CHDI Management/CHDI Foundation, Los Angeles, California, USA
| | | | - Jonathan Bard
- CHDI Management/CHDI Foundation, Los Angeles, California, USA
| | - Longbin Liu
- CHDI Management/CHDI Foundation, Los Angeles, California, USA
| | - Jeroen Verhaeghe
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Antwerp, Belgium
| | - Steven Staelens
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Antwerp, Belgium
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12
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Carson RE, Naganawa M, Toyonaga T, Koohsari S, Yang Y, Chen MK, Matuskey D, Finnema SJ. Imaging of Synaptic Density in Neurodegenerative Disorders. J Nucl Med 2022; 63:60S-67S. [PMID: 35649655 DOI: 10.2967/jnumed.121.263201] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 02/10/2022] [Indexed: 02/07/2023] Open
Abstract
PET technology has produced many radiopharmaceuticals that target specific brain proteins and other measures of brain function. Recently, a new approach has emerged to image synaptic density by targeting the synaptic vesicle protein 2A (SV2A), an integral glycoprotein in the membrane of synaptic vesicles and widely distributed throughout the brain. Multiple SV2A ligands have been developed and translated to human use. The most successful of these to date is 11C-UCB-J, because of its high uptake, moderate metabolism, and effective quantification with a 1-tissue-compartment model. Further, since SV2A is the target of the antiepileptic drug levetiracetam, human blocking studies have characterized specific binding and potential reference regions. Regional brain SV2A levels were shown to correlate with those of synaptophysin, another commonly used marker of synaptic density, providing the basis for SV2A PET imaging to have broad utility across neuropathologic diseases. In this review, we highlight the development of SV2A tracers and the evaluation of quantification methods, including compartment modeling and simple tissue ratios. Mouse and rat models of neurodegenerative diseases have been studied with small-animal PET, providing validation by comparison to direct tissue measures. Next, we review human PET imaging results in multiple neurodegenerative disorders. Studies on Parkinson disease and Alzheimer disease have progressed most rapidly at multiple centers, with generally consistent results of patterns of SV2A or synaptic loss. In Alzheimer disease, the synaptic loss patterns differ from those of amyloid, tau, and 18F-FDG, although intertracer and interregional correlations have been found. Smaller studies have been reported in other disorders, including Lewy body dementia, frontotemporal dementia, Huntington disease, progressive supranuclear palsy, and corticobasal degeneration. In conclusion, PET imaging of SV2A has rapidly developed, and qualified radioligands are available. PET studies on humans indicate that SV2A loss might be specific to disease-associated brain regions and consistent with synaptic density loss. The recent availability of new 18F tracers, 18F-SynVesT-1 and 18F-SynVesT-2, will substantially broaden the application of SV2A PET. Future studies are needed in larger patient cohorts to establish the clinical value of SV2A PET and its potential for diagnosis and progression monitoring of neurodegenerative diseases, as well as efficacy assessment of disease-modifying therapies.
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Affiliation(s)
- Richard E Carson
- Department of Radiology and Biomedical Imaging, Yale Positron Emission Tomography Center, Yale University, New Haven, Connecticut;
- Department of Biomedical Engineering, Yale University, New Haven, Connecticut
| | - Mika Naganawa
- Department of Radiology and Biomedical Imaging, Yale Positron Emission Tomography Center, Yale University, New Haven, Connecticut
| | - Takuya Toyonaga
- Department of Radiology and Biomedical Imaging, Yale Positron Emission Tomography Center, Yale University, New Haven, Connecticut
| | - Sheida Koohsari
- Department of Radiology and Biomedical Imaging, Yale Positron Emission Tomography Center, Yale University, New Haven, Connecticut
| | - Yanghong Yang
- Department of Radiology and Biomedical Imaging, Yale Positron Emission Tomography Center, Yale University, New Haven, Connecticut
| | - Ming-Kai Chen
- Department of Radiology and Biomedical Imaging, Yale Positron Emission Tomography Center, Yale University, New Haven, Connecticut
| | - David Matuskey
- Department of Radiology and Biomedical Imaging, Yale Positron Emission Tomography Center, Yale University, New Haven, Connecticut
- Department of Psychiatry, Yale School of Medicine, New Haven, Connecticut
- Department of Neurology, Yale School of Medicine, New Haven, Connecticut; and
| | - Sjoerd J Finnema
- Neuroscience Discovery Research, Translational Imaging, AbbVie, North Chicago, Illinois
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13
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Rossi R, Arjmand S, Bærentzen SL, Gjedde A, Landau AM. Synaptic Vesicle Glycoprotein 2A: Features and Functions. Front Neurosci 2022; 16:864514. [PMID: 35573314 PMCID: PMC9096842 DOI: 10.3389/fnins.2022.864514] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Accepted: 04/05/2022] [Indexed: 01/05/2023] Open
Abstract
In recent years, the field of neuroimaging dramatically moved forward by means of the expeditious development of specific radioligands of novel targets. Among these targets, the synaptic vesicle glycoprotein 2A (SV2A) is a transmembrane protein of synaptic vesicles, present in all synaptic terminals, irrespective of neurotransmitter content. It is involved in key functions of neurons, focused on the regulation of neurotransmitter release. The ubiquitous expression in gray matter regions of the brain is the basis of its candidacy as a marker of synaptic density. Following the development of molecules derived from the structure of the anti-epileptic drug levetiracetam, which selectively binds to SV2A, several radiolabeled markers have been synthetized to allow the study of SV2A distribution with positron emission tomography (PET). These radioligands permit the evaluation of in vivo changes of SV2A distribution held to be a potential measure of synaptic density in physiological and pathological conditions. The use of SV2A as a biomarker of synaptic density raises important questions. Despite numerous studies over the last decades, the biological function and the expressional properties of SV2A remain poorly understood. Some functions of SV2A were claimed, but have not been fully elucidated. While the expression of SV2A is ubiquitous, stronger associations between SV2A and Υ amino butyric acid (GABA)-ergic rather than glutamatergic synapses were observed in some brain structures. A further issue is the unclear interaction between SV2A and its tracers, which reflects a need to clarify what really is detected with neuroimaging tools. Here, we summarize the current knowledge of the SV2A protein and we discuss uncertain aspects of SV2A biology and physiology. As SV2A expression is ubiquitous, but likely more strongly related to a certain type of neurotransmission in particular circumstances, a more extensive knowledge of the protein would greatly facilitate the analysis and interpretation of neuroimaging results by allowing the evaluation not only of an increase or decrease of the protein level, but also of the type of neurotransmission involved.
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Affiliation(s)
- Rachele Rossi
- Translational Neuropsychiatry Unit, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.,Department of Nuclear Medicine and PET Center, Aarhus University Hospital, Aarhus, Denmark
| | - Shokouh Arjmand
- Translational Neuropsychiatry Unit, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Simone Larsen Bærentzen
- Translational Neuropsychiatry Unit, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.,Department of Nuclear Medicine and PET Center, Aarhus University Hospital, Aarhus, Denmark
| | - Albert Gjedde
- Translational Neuropsychiatry Unit, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.,Department of Neuroscience, University of Copenhagen, Copenhagen, Denmark.,Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada
| | - Anne M Landau
- Translational Neuropsychiatry Unit, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.,Department of Nuclear Medicine and PET Center, Aarhus University Hospital, Aarhus, Denmark
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14
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Association of entorhinal cortical tau deposition and hippocampal synaptic density in older individuals with normal cognition and early Alzheimer's disease. Neurobiol Aging 2022; 111:44-53. [PMID: 34963063 PMCID: PMC8761170 DOI: 10.1016/j.neurobiolaging.2021.11.004] [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: 04/18/2021] [Revised: 11/09/2021] [Accepted: 11/16/2021] [Indexed: 01/26/2023]
Abstract
Sites of early neuropathologic change provide important clues regarding the initial clinical features of Alzheimer's disease (AD). We have shown significant reductions in hippocampal synaptic density in participants with AD, consistent with the early degeneration of entorhinal cortical (ERC) cells that project to hippocampus via the perforant path. In this study, [11C]UCB-J binding to synaptic vesicle glycoprotein 2A (SV2A) and [18F]flortaucipir binding to tau were measured via PET in 10 participants with AD (5 mild cognitive impairment, 5 mild dementia) and 10 cognitively normal participants. In the overall sample, ERC tau was inversely associated with hippocampal synaptic density (r = -0.59, p = 0.009). After correction for partial volume effects, the association of ERC tau with hippocampal synaptic density was stronger in the overall sample (r = -0.61, p = 0.007) and in the AD group where the effect size was large, but not statistically significant (r = -0.58, p = 0.06). This inverse association of ERC tau and hippocampal synaptic density may reflect synaptic failure due to tau pathology in ERC neurons projecting to the hippocampus.
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15
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Angarita GA, Worhunsky PD, Naganawa M, Toyonaga T, Nabulsi NB, Li CSR, Esterlis I, Skosnik PD, Radhakrishnan R, Pittman B, Gueorguieva R, Potenza MN, Finnema SJ, Huang Y, Carson RE, Malison RT. Lower prefrontal cortical synaptic vesicle binding in cocaine use disorder: An exploratory 11 C-UCB-J positron emission tomography study in humans. Addict Biol 2022; 27:e13123. [PMID: 34852401 PMCID: PMC8891080 DOI: 10.1111/adb.13123] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 09/22/2021] [Accepted: 11/12/2021] [Indexed: 12/22/2022]
Abstract
Preclinical studies have revealed robust and long-lasting alterations in dendritic spines in the brain following cocaine exposure. Such alterations are hypothesized to underlie enduring maladaptive behaviours observed in cocaine use disorder (CUD). The current study explored whether synaptic density is altered in CUD. Fifteen individuals with DSM-5 CUD and 15 demographically matched healthy control (HC) subjects participated in a single 11 C-UCB-J positron emission tomography scan to assess density of synaptic vesicle glycoprotein 2A (SV2A). The volume of distribution (VT ) and the plasma-free fraction-corrected form of the total volume of distribution (VT /fP ) were analysed in the anterior cingulate cortex (ACC), dorsomedial and ventromedial prefrontal cortex (PFC), lateral and medial orbitofrontal cortex (OFC) and ventral striatum. A significant diagnostic-group-by-region interaction was observed for VT and VT /fP . Post hoc analyses revealed no differences on VT , while for VT /fP showed lower values in CUD as compared with HC subjects in the ACC (-10.9%, p = 0.02), ventromedial PFC (-9.9%, p = 0.02) and medial OFC (-9.9%, p = 0.04). Regional VT /fP values in CUD, though unrelated to measures of lifetime cocaine use, were positively correlated with the frequency of recent cocaine use (p = 0.02-0.03) and negatively correlated with cocaine abstinence (p = 0.008-0.03). These findings provide initial preliminary in vivo evidence of altered (lower) synaptic density in the PFC of humans with CUD. Cross-sectional variation in SV2A availability as a function of recent cocaine use and abstinence suggests that synaptic density may be dynamically and plastically regulated by acute cocaine, an observation that merits direct testing by studies using more definitive longitudinal designs.
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Affiliation(s)
- Gustavo A. Angarita
- Department of Psychiatry, Yale University School of Medicine, 300 George Street, Suite # 901, New Haven, CT 06511
- Connecticut Mental Health Center, 34 Park Street, New Haven, CT 06519
| | - Patrick D. Worhunsky
- Department of Psychiatry, Yale University School of Medicine, 300 George Street, Suite # 901, New Haven, CT 06511
| | - Mika Naganawa
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, 801 Howard Ave, New Haven, CT 06519
| | - Takuya Toyonaga
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, 801 Howard Ave, New Haven, CT 06519
| | - Nabeel B. Nabulsi
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, 801 Howard Ave, New Haven, CT 06519
| | - Chiang-Shan R. Li
- Department of Psychiatry, Yale University School of Medicine, 300 George Street, Suite # 901, New Haven, CT 06511
- Connecticut Mental Health Center, 34 Park Street, New Haven, CT 06519
| | - Irina Esterlis
- Department of Psychiatry, Yale University School of Medicine, 300 George Street, Suite # 901, New Haven, CT 06511
| | - Patrick D. Skosnik
- Department of Psychiatry, Yale University School of Medicine, 300 George Street, Suite # 901, New Haven, CT 06511
| | - Rajiv Radhakrishnan
- Department of Psychiatry, Yale University School of Medicine, 300 George Street, Suite # 901, New Haven, CT 06511
| | - Brian Pittman
- Department of Psychiatry, Yale University School of Medicine, 300 George Street, Suite # 901, New Haven, CT 06511
| | - Ralitza Gueorguieva
- Department of Biostatistics, Yale School of Public Health, 60 College Street, New Haven CT 06520
| | - Marc N. Potenza
- Department of Psychiatry, Yale University School of Medicine, 300 George Street, Suite # 901, New Haven, CT 06511
- Connecticut Mental Health Center, 34 Park Street, New Haven, CT 06519
- Connecticut Council on Problem Gambling, 100 Great Meadow Road, Wethersfield, CT 06109
- Child Study Center, Yale University School of Medicine, 234 South Frontage Road, New Haven, CT 06510
- Department of Neuroscience, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06510
| | - Sjoerd J. Finnema
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, 801 Howard Ave, New Haven, CT 06519
| | - Yiyun Huang
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, 801 Howard Ave, New Haven, CT 06519
| | - Richard E. Carson
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, 801 Howard Ave, New Haven, CT 06519
| | - Robert T. Malison
- Department of Psychiatry, Yale University School of Medicine, 300 George Street, Suite # 901, New Haven, CT 06511
- Connecticut Mental Health Center, 34 Park Street, New Haven, CT 06519
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16
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Martins D, Giacomel A, Williams SCR, Turkheimer F, Dipasquale O, Veronese M. Imaging transcriptomics: Convergent cellular, transcriptomic, and molecular neuroimaging signatures in the healthy adult human brain. Cell Rep 2021; 37:110173. [PMID: 34965413 DOI: 10.1016/j.celrep.2021.110173] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Revised: 09/30/2021] [Accepted: 12/03/2021] [Indexed: 12/12/2022] Open
Abstract
The integration of transcriptomic and neuroimaging data, "imaging transcriptomics," has recently emerged to generate hypotheses about potential biological pathways underlying regional variability in neuroimaging features. However, the validity of this approach is yet to be examined in depth. Here, we sought to bridge this gap by performing transcriptomic decoding of the regional distribution of well-known molecular markers spanning different elements of the biology of the healthy human brain. Imaging transcriptomics identifies biological and cell pathways that are consistent with the known biology of a wide range of molecular neuroimaging markers. The extent to which it can capture patterns of gene expression that align well with elements of the biology of the neuroinflammatory axis, at least in healthy controls without a proinflammatory challenge, is inconclusive. Imaging transcriptomics might constitute an interesting approach to improve our understanding of the biological pathways underlying regional variability in a wide range of neuroimaging phenotypes.
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Affiliation(s)
- Daniel Martins
- Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King's College London, De Crespigny Park, London SE5 8AF, UK.
| | - Alessio Giacomel
- Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King's College London, De Crespigny Park, London SE5 8AF, UK
| | - Steven C R Williams
- Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King's College London, De Crespigny Park, London SE5 8AF, UK
| | - Federico Turkheimer
- Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King's College London, De Crespigny Park, London SE5 8AF, UK
| | - Ottavia Dipasquale
- Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King's College London, De Crespigny Park, London SE5 8AF, UK
| | - Mattia Veronese
- Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King's College London, De Crespigny Park, London SE5 8AF, UK; Department of Information Engineering, University of Padua, Via Gradenigo, 6/b, 35131 Padova, Italy.
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17
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Yee SW, Giacomini KM. Emerging Roles of the Human Solute Carrier 22 Family. Drug Metab Dispos 2021; 50:DMD-MR-2021-000702. [PMID: 34921098 PMCID: PMC9488978 DOI: 10.1124/dmd.121.000702] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 11/22/2021] [Accepted: 12/08/2021] [Indexed: 11/22/2022] Open
Abstract
The human Solute Carrier 22 family (SLC22), also termed the organic ion transporter family, consists of 28 distinct multi-membrane spanning proteins, which phylogenetically cluster together according to their charge specificity for organic cations (OCTs), organic anions (OATs) and organic zwitterion/cations (OCTNs). Some SLC22 family members are well characterized in terms of their substrates, transport mechanisms and expression patterns, as well as their roles in human physiology and pharmacology, whereas others remain orphans with no known ligands. Pharmacologically, SLC22 family members play major roles as determinants of the absorption and disposition of many prescription drugs, and several including the renal transporters, OCT2, OAT1 and OAT3 are targets for many clinically important drug-drug interactions. In addition, mutations in some of these transporters (SLC22A5 (OCTN2) and SLC22A12 (URAT1) lead to rare monogenic disorders. Genetic polymorphisms in SLC22 transporters have been associated with common human disease, drug response and various phenotypic traits. Three members in this family were deorphaned in very recently: SLC22A14, SLC22A15 and SLC22A24, and found to transport specific compounds such as riboflavin (SLC22A14), anti-oxidant zwitterions (SLC22A15) and steroid conjugates (SLC22A24). Their physiologic and pharmacological roles need further investigation. This review aims to summarize the substrates, expression patterns and transporter mechanisms of individual SLC22 family members and their roles in human disease and drug disposition and response. Gaps in our understanding of SLC22 family members are described. Significance Statement In recent years, three members of the SLC22 family of transporters have been deorphaned and found to play important roles in the transport of diverse solutes. New research has furthered our understanding of the mechanisms, pharmacological roles, and clinical impact of SLC22 transporters. This minireview provides overview of SLC22 family members of their physiologic and pharmacologic roles, the impact of genetic variants in the SLC22 family on disease and drug response, and summary of recent studies deorphaning SLC22 family members.
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Affiliation(s)
- Sook Wah Yee
- Bioengineering and Therapeutic Sciences, Univerity of California, San Francisco, United States
| | - Kathleen M Giacomini
- Bioengineering and Therapeutic Sciences, Univerity of California, San Francisco, United States
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18
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In vivo evidence of lower synaptic vesicle density in schizophrenia. Mol Psychiatry 2021; 26:7690-7698. [PMID: 34135473 DOI: 10.1038/s41380-021-01184-0] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/12/2020] [Revised: 05/20/2021] [Accepted: 05/28/2021] [Indexed: 02/05/2023]
Abstract
Decreased synaptic spine density has been the most consistently reported postmortem finding in schizophrenia (SCZ). A recently developed in vivo measure of synaptic vesicle density estimated using the novel positron emission tomography (PET) ligand [11C]UCB-J is a proxy measure of synaptic density. In this study we determined whether [11C]UCB-J binding, an in vivo measure of synaptic vesicle density, is altered in SCZ. SCZ patients (n = 13, 3 F) and age-, gender-matched healthy controls (HCs) (n = 15, 3 F) underwent PET imaging using [11C]UCB-J and high-resolution research tomography (HRRT). [11C]UCB-J distribution volume (VT) and binding potential (BPND) were estimated using a 1T model with centrum-semiovale as the reference region. Relative to HCs, SCZ patients, showed significantly lower [11C]UCB-J BPND with significant differences in the frontal cortex (-10%, Cohen's d = 1.01), anterior cingulate (-11%, Cohen's d = 1.24), hippocampus (-15%, Cohen's d = 1.29), occipital cortex (-14%, Cohen's d = 1.34), parietal cortex (-10%, p = 0.03, Cohen's d = 0.85) and temporal cortex (-11%, Cohen's d = 1.23). These differences remained significant after partial volume correction. [11C]UCB-J BPND did not correlate with cumulative antipsychotic exposure or gray-matter volume. Consistent with the postmortem and in vivo findings, synaptic vesicle density is lower across several brain regions in SCZ. Frontal synaptic vesicle density correlated with psychosis symptom severity and cognitive performance on social cognition and processing speed. These findings indicate that [11C]UCB-J PET is a sensitive tool to detect lower synaptic density in SCZ and holds promise for future studies of early detection and disease progression.
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19
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Chen MK, Mecca AP, Naganawa M, Gallezot JD, Toyonaga T, Mondal J, Finnema SJ, Lin SF, O’Dell RS, McDonald JW, Michalak HR, Vander Wyk B, Nabulsi NB, Huang Y, Arnsten AFT, van Dyck CH, Carson RE. Comparison of [ 11C]UCB-J and [ 18F]FDG PET in Alzheimer's disease: A tracer kinetic modeling study. J Cereb Blood Flow Metab 2021; 41:2395-2409. [PMID: 33757318 PMCID: PMC8393289 DOI: 10.1177/0271678x211004312] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Revised: 01/29/2021] [Accepted: 02/21/2021] [Indexed: 11/16/2022]
Abstract
[11C]UCB-J PET for synaptic vesicle glycoprotein 2 A (SV2A) has been proposed as a suitable marker for synaptic density in Alzheimer's disease (AD). We compared [11C]UCB-J binding for synaptic density and [18F]FDG uptake for metabolism (correlated with neuronal activity) in 14 AD and 11 cognitively normal (CN) participants. We assessed both absolute and relative outcome measures in brain regions of interest, i.e., K1 or R1 for [11C]UCB-J perfusion, VT (volume of distribution) or DVR to cerebellum for [11C]UCB-J binding to SV2A; and Ki or KiR to cerebellum for [18F]FDG metabolism. [11C]UCB-J binding and [18F]FDG metabolism showed a similar magnitude of reduction in the medial temporal lobe of AD -compared to CN participants. However, the magnitude of reduction of [11C]UCB-J binding in neocortical regions was less than that observed with [18F]FDG metabolism. Inter-tracer correlations were also higher in the medial temporal regions between synaptic density and metabolism, with lower correlations in neocortical regions. [11C]UCB-J perfusion showed a similar pattern to [18F]FDG metabolism, with high inter-tracer regional correlations. In summary, we conducted the first in vivo PET imaging of synaptic density and metabolism in the same AD participants and reported a concordant reduction in medial temporal regions but a discordant reduction in neocortical regions.
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Affiliation(s)
- Ming-Kai Chen
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, CT, USA
| | - Adam P Mecca
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
| | - Mika Naganawa
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, CT, USA
| | - Jean-Dominique Gallezot
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, CT, USA
| | - Takuya Toyonaga
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, CT, USA
| | - Jayanta Mondal
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, CT, USA
| | - Sjoerd J Finnema
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, CT, USA
| | - Shu-fei Lin
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, CT, USA
| | - Ryan S O’Dell
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
| | - Julia W McDonald
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
| | - Hannah R Michalak
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
| | - Brent Vander Wyk
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
| | - Nabeel B Nabulsi
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, CT, USA
| | - Yiyun Huang
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, CT, USA
| | - Amy FT Arnsten
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
| | | | - Richard E Carson
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, CT, USA
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20
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Holland N, Malpetti M, Rittman T, Mak EE, Passamonti L, Kaalund SS, Hezemans FH, Jones PS, Savulich G, Hong YT, Fryer TD, Aigbirhio FI, O'Brien JT, Rowe JB. Molecular pathology and synaptic loss in primary tauopathies: an 18F-AV-1451 and 11C-UCB-J PET study. Brain 2021; 145:340-348. [PMID: 34398211 PMCID: PMC8967099 DOI: 10.1093/brain/awab282] [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] [Received: 03/02/2021] [Revised: 07/02/2021] [Accepted: 07/10/2021] [Indexed: 12/02/2022] Open
Abstract
The relationship between in vivo synaptic density and molecular pathology in primary tauopathies is key to understanding the impact of tauopathy on functional decline and in informing new early therapeutic strategies. In this cross-sectional observational study, we determine the in vivo relationship between synaptic density and molecular pathology in the primary tauopathies of progressive supranuclear palsy and corticobasal degeneration as a function of disease severity. Twenty-three patients with progressive supranuclear palsy and 12 patients with corticobasal syndrome were recruited from a tertiary referral centre. Nineteen education-, sex- and gender-matched control participants were recruited from the National Institute for Health Research ‘Join Dementia Research’ platform. Cerebral synaptic density and molecular pathology, in all participants, were estimated using PET imaging with the radioligands 11C-UCB-J and 18F-AV-1451, respectively. Patients with corticobasal syndrome also underwent amyloid PET imaging with 11C-PiB to exclude those with likely Alzheimer’s pathology—we refer to the amyloid-negative cohort as having corticobasal degeneration, although we acknowledge other underlying pathologies exist. Disease severity was assessed with the progressive supranuclear palsy rating scale; regional non-displaceable binding potentials of 11C-UCB-J and 18F-AV-1451 were estimated in regions of interest from the Hammersmith Atlas, excluding those with known off-target binding for 18F-AV-1451. As an exploratory analysis, we also investigated the relationship between molecular pathology in cortical brain regions and synaptic density in subcortical areas. Across brain regions, there was a positive correlation between 11C-UCB-J and 18F-AV-1451 non-displaceable binding potentials (β = 0.4, t = 3.6, P = 0.001), independent of age or time between PET scans. However, this correlation became less positive as a function of disease severity in patients (β = −0.02, t = −2.9, P = 0.007, R = −0.41). Between regions, cortical 18F-AV-1451 binding was negatively correlated with synaptic density in subcortical areas (caudate nucleus, putamen). Brain regions with higher synaptic density are associated with a higher 18F-AV-1451 binding in progressive supranuclear palsy/corticobasal degeneration, but this association diminishes with disease severity. Moreover, higher cortical 18F-AV-1451 binding correlates with lower subcortical synaptic density. Longitudinal imaging is required to confirm the mediation of synaptic loss by molecular pathology. However, the effect of disease severity suggests a biphasic relationship between synaptic density and molecular pathology with synapse-rich regions vulnerable to accrual of pathological aggregates, followed by a loss of synapses in response to the molecular pathology. Given the importance of synaptic function for cognition and action, our study elucidates the pathophysiology of primary tauopathies and may inform the design of future clinical trials.
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Affiliation(s)
- Negin Holland
- Department of Clinical Neurosciences, University of Cambridge, Cambridge Biomedical Campus, Cambridge, CB2 0SZ, UK.,Cambridge University Hospitals NHS Foundation Trust, Cambridge, CB2 0QQ, UK
| | - Maura Malpetti
- Department of Clinical Neurosciences, University of Cambridge, Cambridge Biomedical Campus, Cambridge, CB2 0SZ, UK
| | - Timothy Rittman
- Department of Clinical Neurosciences, University of Cambridge, Cambridge Biomedical Campus, Cambridge, CB2 0SZ, UK.,Cambridge University Hospitals NHS Foundation Trust, Cambridge, CB2 0QQ, UK
| | - Elijah E Mak
- Department of Psychiatry, University of Cambridge, School of Clinical Medicine, Cambridge Biomedical Campus, CB2 0QQ, UK
| | - Luca Passamonti
- Department of Clinical Neurosciences, University of Cambridge, Cambridge Biomedical Campus, Cambridge, CB2 0SZ, UK.,Istituto di Bioimmagini e Fisiologia Molecolare (IBFM), Consiglio Nazionale delle Ricerche (CNR), 20090, Milano, Italy
| | - Sanne S Kaalund
- Department of Clinical Neurosciences, University of Cambridge, Cambridge Biomedical Campus, Cambridge, CB2 0SZ, UK
| | - Frank H Hezemans
- Department of Clinical Neurosciences, University of Cambridge, Cambridge Biomedical Campus, Cambridge, CB2 0SZ, UK.,Medical Research Council Cognition and Brain Sciences Unit, University of Cambridge, CB2 7EF, UK
| | - P Simon Jones
- Department of Clinical Neurosciences, University of Cambridge, Cambridge Biomedical Campus, Cambridge, CB2 0SZ, UK
| | - George Savulich
- Department of Psychiatry, University of Cambridge, School of Clinical Medicine, Cambridge Biomedical Campus, CB2 0QQ, UK
| | - Young T Hong
- Wolfson Brain Imaging Centre, University of Cambridge, CB2 0QQ, UK
| | - Tim D Fryer
- Department of Clinical Neurosciences, University of Cambridge, Cambridge Biomedical Campus, Cambridge, CB2 0SZ, UK.,Wolfson Brain Imaging Centre, University of Cambridge, CB2 0QQ, UK
| | - Franklin I Aigbirhio
- Department of Clinical Neurosciences, University of Cambridge, Cambridge Biomedical Campus, Cambridge, CB2 0SZ, UK
| | - John T O'Brien
- Cambridge University Hospitals NHS Foundation Trust, Cambridge, CB2 0QQ, UK.,Department of Psychiatry, University of Cambridge, School of Clinical Medicine, Cambridge Biomedical Campus, CB2 0QQ, UK
| | - James B Rowe
- Department of Clinical Neurosciences, University of Cambridge, Cambridge Biomedical Campus, Cambridge, CB2 0SZ, UK.,Cambridge University Hospitals NHS Foundation Trust, Cambridge, CB2 0QQ, UK.,Medical Research Council Cognition and Brain Sciences Unit, University of Cambridge, CB2 7EF, UK
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21
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Binda KH, Lillethorup TP, Real CC, Bærentzen SL, Nielsen MN, Orlowski D, Brooks DJ, Chacur M, Landau AM. Exercise protects synaptic density in a rat model of Parkinson's disease. Exp Neurol 2021; 342:113741. [PMID: 33965411 DOI: 10.1016/j.expneurol.2021.113741] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Accepted: 05/04/2021] [Indexed: 01/09/2023]
Abstract
BACKGROUND Parkinson's disease (PD) is characterized by Lewy body and neurite pathology associated with dopamine terminal dysfunction. Clinically, it is associated with motor slowing, rigidity, and tremor. Postural instability and pain are also features. Physical exercise benefits PD patients - possibly by promoting neuroplasticity including synaptic regeneration. OBJECTIVES In a parkinsonian rat model, we test the hypotheses that exercise: (a) increases synaptic density and reduces neuroinflammation and (b) lowers the nociceptive threshold by increasing μ-opioid receptor expression. METHODS Brain autoradiography was performed on rats unilaterally injected with either 6-hydroxydopamine (6-OHDA) or saline and subjected to treadmill exercise over 5 weeks. [3H]UCB-J was used to measure synaptic vesicle glycoprotein 2A (SV2A) density. Dopamine D2/3 receptor and μ-opioid receptor availability were assessed with [3H]Raclopride and [3H]DAMGO, respectively, while neuroinflammation was detected with the 18kDA translocator protein (TSPO) marker [3H]PK11195. The nociceptive threshold was determined prior to and throughout the exercise protocol. RESULTS We confirmed a dopaminegic deficit with increased striatal [3H]Raclopride D2/3 receptor availability and reduced nigral tyrosine hydroxylase immunoreactivity in the ipsilateral hemisphere of all 6-OHDA-injected rats. Sedentary rats lesioned with 6-OHDA showed significant reduction of ipsilateral striatal and substantia nigra [3H]UCB-J binding while [3H]PK11195 showed increased ipsilateral striatal neuroinflammation. Lesioned rats who exercised had higher levels of ipsilateral striatal [3H]UCB-J binding and lower levels of neuroinflammation compared to sedentary lesioned rats. Striatal 6-OHDA injections reduced thalamic μ-opioid receptor availability but subsequent exercise restored binding. Exercise also raised thalamic and hippocampal SV2A synaptic density in 6-OHDA lesioned rats, accompanied by a rise in nociceptive threshold. CONCLUSION These data suggest that treadmill exercise protects nigral and striatal synaptic integrity in a rat lesion model of PD - possibly by promoting compensatory mechanisms. Exercise was also associated with reduced neuroinflammation post lesioning and altered opioid transmission resulting in an increased nociceptive threshold.
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Affiliation(s)
- K H Binda
- Translational Neuropsychiatry Unit, Aarhus University, Universitetsbyen 13, Building 2b, Aarhus C 8000, Denmark; Department of Nuclear Medicine and PET, Aarhus University and Hospital, Palle Juul-Jensens Boulevard 165, J109, Aarhus N 8200, Denmark; Laboratory of Functional Neuroanatomy of Pain, Departamento de Anatomia, Universidade de Sao Paulo, Sao Paulo, SP, Brazil.
| | - T P Lillethorup
- Department of Nuclear Medicine and PET, Aarhus University and Hospital, Palle Juul-Jensens Boulevard 165, J109, Aarhus N 8200, Denmark.
| | - C C Real
- Translational Neuropsychiatry Unit, Aarhus University, Universitetsbyen 13, Building 2b, Aarhus C 8000, Denmark; Department of Nuclear Medicine and PET, Aarhus University and Hospital, Palle Juul-Jensens Boulevard 165, J109, Aarhus N 8200, Denmark; Laboratory of Nuclear Medicine (LIM 43), Faculdade de Medicina FMUSP, Universidade de Sao Paulo, Sao Paulo, SP, Brazil.
| | - S L Bærentzen
- Translational Neuropsychiatry Unit, Aarhus University, Universitetsbyen 13, Building 2b, Aarhus C 8000, Denmark; Department of Nuclear Medicine and PET, Aarhus University and Hospital, Palle Juul-Jensens Boulevard 165, J109, Aarhus N 8200, Denmark.
| | - M N Nielsen
- Translational Neuropsychiatry Unit, Aarhus University, Universitetsbyen 13, Building 2b, Aarhus C 8000, Denmark.
| | - D Orlowski
- Center for Experimental Neuroscience (CENSE), Department of Clinical Medicine, Aarhus University and Department of Neurosurgery, Aarhus University Hospital, Aarhus N, 8200, Denmark.
| | - D J Brooks
- Department of Nuclear Medicine and PET, Aarhus University and Hospital, Palle Juul-Jensens Boulevard 165, J109, Aarhus N 8200, Denmark; Institute for Translational and Clinical Research, Newcastle University, Newcastle upon Tyne NE4 5PL, UK.
| | - M Chacur
- Laboratory of Functional Neuroanatomy of Pain, Departamento de Anatomia, Universidade de Sao Paulo, Sao Paulo, SP, Brazil.
| | - A M Landau
- Translational Neuropsychiatry Unit, Aarhus University, Universitetsbyen 13, Building 2b, Aarhus C 8000, Denmark; Department of Nuclear Medicine and PET, Aarhus University and Hospital, Palle Juul-Jensens Boulevard 165, J109, Aarhus N 8200, Denmark.
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22
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Takahashi S, Takechi K, Jozukuri N, Niimura T, Chuma M, Goda M, Zamami Y, Izawa-Ishizawa Y, Imanishi M, Horinouchi Y, Ikeda Y, Tsuchiya K, Yanagawa H, Ishizawa K. Examination of the antiepileptic effects of valacyclovir using kindling mice- search for novel antiepileptic agents by drug repositioning using a large medical information database. Eur J Pharmacol 2021; 902:174099. [PMID: 33910036 DOI: 10.1016/j.ejphar.2021.174099] [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: 01/06/2021] [Revised: 03/31/2021] [Accepted: 04/07/2021] [Indexed: 11/26/2022]
Abstract
Despite the availability of more than 20 clinical antiepileptic drugs, approximately 30% of patients with epilepsy do not respond to antiepileptic drug treatment. Therefore, it is important to develop antiepileptic products that function via novel mechanisms. In the present study, we evaluated data from one of the largest global databases to identify drugs with antiepileptic effects, and subsequently attempted to understand the effect of the combination of antiepileptic drugs and valacyclovir in epileptic seizures using a kindling model. To induce kindling in mice, pentylenetetrazol at a dose of 40 mg/kg was administered once every 48 h. Valacyclovir was orally administered 30 min before antiepileptic drug injection in kindled mice, and behavioral seizures were monitored for 20 min following pentylenetetrazol administration. Additionally, c-Fos expression in the hippocampal dentate gyrus was measured in kindled mice. Valacyclovir showed inhibitory effects on pentylenetetrazol-induced kindled seizures. In addition, simultaneous use of levetiracetam and valacyclovir caused more potent inhibition of seizure activity, and neither valproic acid nor diazepam augmented the anti-seizure effect in kindled mice. Furthermore, kindled mice showed increased c-Fos levels in the dentate gyrus. The increase in c-Fos expression was significantly inhibited by the simultaneous use of levetiracetam and valacyclovir. The findings of the present study indicate that a combination of levetiracetam and valacyclovir had possible anticonvulsive effects on pentylenetetrazol-induced kindled epileptic seizures. These results suggest that valacyclovir may have an antiseizure effect in patients with epilepsy.
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Affiliation(s)
- Shimon Takahashi
- Department of Clinical Pharmacology and Therapeutics, Tokushima University Graduate School of Biomedical Sciences, Japan; Department of Pharmacy, Tokushima University Hospital, Japan
| | - Kenshi Takechi
- Department of Drug Information Analysis, College of Pharmaceutical Sciences, Matsuyama University, Japan.
| | - Natsumi Jozukuri
- Department of Clinical Pharmacology and Therapeutics, Tokushima University Graduate School of Biomedical Sciences, Japan
| | - Takahiro Niimura
- Department of Clinical Pharmacology and Therapeutics, Tokushima University Graduate School of Biomedical Sciences, Japan
| | - Masayuki Chuma
- Department of Hospital Pharmacy & Pharmacology, Asahikawa Medical University & University Hospital, Japan
| | - Mitsuhiro Goda
- Department of Clinical Pharmacology and Therapeutics, Tokushima University Graduate School of Biomedical Sciences, Japan; Clinical Research Center for Developmental Therapeutics, Tokushima University Hospital, Tokushima, Japan
| | - Yoshito Zamami
- Department of Clinical Pharmacology and Therapeutics, Tokushima University Graduate School of Biomedical Sciences, Japan; Department of Pharmacy, Tokushima University Hospital, Japan
| | - Yuki Izawa-Ishizawa
- Department of Pharmacology, Institute of Biomedical Sciences, Tokushima University Graduate School, AWA Support Center, Japan
| | - Masaki Imanishi
- Department of Clinical Pharmacology and Therapeutics, Tokushima University Graduate School of Biomedical Sciences, Japan
| | - Yuya Horinouchi
- Department of Pharmaceutical Care and Clinical Pharmacy, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, 180 Nishihamabouji Yamashiro-cho, Tokushima, 770-8514, Japan
| | - Yasumasa Ikeda
- Department of Pharmacology, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan
| | - Koichiro Tsuchiya
- Department of Medical Pharmacology, Tokushima University Graduate School of Biomedical Sciences, Tokushima, Japan
| | - Hiroaki Yanagawa
- Clinical Research Center for Developmental Therapeutics, Tokushima University Hospital, Tokushima, Japan
| | - Keisuke Ishizawa
- Department of Clinical Pharmacology and Therapeutics, Tokushima University Graduate School of Biomedical Sciences, Japan; Department of Pharmacy, Tokushima University Hospital, Japan
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23
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Lekholm E, Ceder MM, Forsberg EC, Schiöth HB, Fredriksson R. Differentiation of two human neuroblastoma cell lines alters SV2 expression patterns. Cell Mol Biol Lett 2021; 26:5. [PMID: 33588752 PMCID: PMC7885392 DOI: 10.1186/s11658-020-00243-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Accepted: 12/07/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The synaptic vesicle glycoprotein 2 (SV2) family is essential to the synaptic machinery involved in neurotransmission and vesicle recycling. The isoforms SV2A, SV2B and SV2C are implicated in neurological diseases such as epilepsy, Alzheimer's and Parkinson's disease. Suitable cell systems for studying regulation of these proteins are essential. Here we present gene expression data of SV2A, SV2B and SV2C in two human neuroblastoma cell lines after differentiation. METHODS Human neuroblastoma cell lines SiMa and IMR-32 were treated for seven days with growth supplements (B-27 and N-2), all-trans-retinoic acid (ATRA) or vasoactive intestinal peptide (VIP) and gene expression levels of SV2 and neuronal targets were analyzed. RESULTS The two cell lines reacted differently to the treatments, and only one of the three SV2 isoforms was affected at a time. SV2B and choline O-acetyltransferase (CHAT) expression was changed in concert after growth supplement treatment, decreasing in SiMa cells while increasing in IMR-32. ATRA treatment resulted in no detected changes in SV2 expression in either cell line while VIP increased both SV2C and dopamine transporter (DAT) in IMR-32 cells. CONCLUSION The synergistic expression patterns between SV2B and CHAT as well as between SV2C and DAT mirror the connectivity between these targets found in disease models and knock-out animals, although here no genetic alteration was made. These cell lines and differentiation treatments could possibly be used to study SV2 regulation and function.
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Affiliation(s)
- Emilia Lekholm
- Functional Pharmacology, Department of Neuroscience, Uppsala University, Uppsala, Sweden. .,Molecular Neuropharmacology, Department of Pharmaceutical Biosciences, Uppsala University, Uppsala, Sweden.
| | - Mikaela M Ceder
- Molecular Neuropharmacology, Department of Pharmaceutical Biosciences, Uppsala University, Uppsala, Sweden
| | - Erica C Forsberg
- Molecular Neuropharmacology, Department of Pharmaceutical Biosciences, Uppsala University, Uppsala, Sweden
| | - Helgi B Schiöth
- Functional Pharmacology, Department of Neuroscience, Uppsala University, Uppsala, Sweden.,Institute for Translational Medicine and Biotechnology, Sechenov First Moscow State Medical University, Moscow, Russia
| | - Robert Fredriksson
- Molecular Neuropharmacology, Department of Pharmaceutical Biosciences, Uppsala University, Uppsala, Sweden
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24
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Calame DG, Herman I, Riviello JJ. A de novo heterozygous rare variant in SV2A causes epilepsy and levetiracetam-induced drug-resistant status epilepticus. Epilepsy Behav Rep 2021; 15:100425. [PMID: 33554103 PMCID: PMC7844124 DOI: 10.1016/j.ebr.2020.100425] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 12/23/2020] [Accepted: 12/28/2020] [Indexed: 11/01/2022] Open
Abstract
SV2A encodes a neuronal synaptic vesicle glycoprotein essential for neurotransmitter release. Altered SV2A function leads to epilepsy in animal models, yet only two reports of human variants have linked SV2A to syndromic drug-resistant epileptic encephalopathies and epilepsy. SV2A is also the binding site for the commonly used antiseizure medication levetiracetam (LEV). However, information about how rare SV2A variants influence LEV response is lacking. Here, we report a two-year-old child with new-onset epilepsy found to have a de novo heterozygous rare variant in SV2A (NM_014849.5:c.1978G>A;p.Gly660Arg) who developed refractory status epilepticus after escalation of LEV treatment for initial baseline seizure control. This report provides additional evidence that monoallelic pathogenic SV2A variants cause epilepsy and that genetic variation in SV2A could lead to paradoxical seizure worsening when treated with LEV.
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Affiliation(s)
- Daniel G Calame
- Department of Pediatrics, Section of Pediatric Neurology and Developmental Neuroscience, Baylor College of Medicine, Houston, TX 77030, United States
| | - Isabella Herman
- Department of Pediatrics, Section of Pediatric Neurology and Developmental Neuroscience, Baylor College of Medicine, Houston, TX 77030, United States
| | - James J Riviello
- Department of Pediatrics, Section of Pediatric Neurology and Developmental Neuroscience, Baylor College of Medicine, Houston, TX 77030, United States
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25
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Goud NS, Bhattacharya A, Joshi RK, Nagaraj C, Bharath RD, Kumar P. Carbon-11: Radiochemistry and Target-Based PET Molecular Imaging Applications in Oncology, Cardiology, and Neurology. J Med Chem 2021; 64:1223-1259. [PMID: 33499603 DOI: 10.1021/acs.jmedchem.0c01053] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The positron emission tomography (PET) molecular imaging technique has gained its universal value as a remarkable tool for medical diagnosis and biomedical research. Carbon-11 is one of the promising radiotracers that can report target-specific information related to its pharmacology and physiology to understand the disease status. Currently, many of the available carbon-11 (t1/2 = 20.4 min) PET radiotracers are heterocyclic derivatives that have been synthesized using carbon-11 inserted different functional groups obtained from primary and secondary carbon-11 precursors. A spectrum of carbon-11 PET radiotracers has been developed against many of the upregulated and emerging targets for the diagnosis, prognosis, prediction, and therapy in the fields of oncology, cardiology, and neurology. This review focuses on the carbon-11 radiochemistry and various target-specific PET molecular imaging agents used in tumor, heart, brain, and neuroinflammatory disease imaging along with its associated pathology.
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Affiliation(s)
- Nerella Sridhar Goud
- Department of Neuroimaging and Interventional Radiology (NIIR), National Institute of Mental Health and Neuro Sciences (NIMHANS), Bengaluru 560 029, India
| | - Ahana Bhattacharya
- Department of Neuroimaging and Interventional Radiology (NIIR), National Institute of Mental Health and Neuro Sciences (NIMHANS), Bengaluru 560 029, India
| | - Raman Kumar Joshi
- Department of Neuroimaging and Interventional Radiology (NIIR), National Institute of Mental Health and Neuro Sciences (NIMHANS), Bengaluru 560 029, India
| | - Chandana Nagaraj
- Department of Neuroimaging and Interventional Radiology (NIIR), National Institute of Mental Health and Neuro Sciences (NIMHANS), Bengaluru 560 029, India
| | - Rose Dawn Bharath
- Department of Neuroimaging and Interventional Radiology (NIIR), National Institute of Mental Health and Neuro Sciences (NIMHANS), Bengaluru 560 029, India
| | - Pardeep Kumar
- Department of Neuroimaging and Interventional Radiology (NIIR), National Institute of Mental Health and Neuro Sciences (NIMHANS), Bengaluru 560 029, India
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O’Dell RS, Mecca AP, Chen MK, Naganawa M, Toyonaga T, Lu Y, Godek TA, Harris JE, Bartlett HH, Banks ER, Kominek VL, Zhao W, Nabulsi NB, Ropchan J, Ye Y, Vander Wyk BC, Huang Y, Arnsten AFT, Carson RE, van Dyck CH. Association of Aβ deposition and regional synaptic density in early Alzheimer's disease: a PET imaging study with [ 11C]UCB-J. Alzheimers Res Ther 2021; 13:11. [PMID: 33402201 PMCID: PMC7786921 DOI: 10.1186/s13195-020-00742-y] [Citation(s) in RCA: 46] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Accepted: 12/07/2020] [Indexed: 01/18/2023]
Abstract
BACKGROUND Attempts to associate amyloid-β (Aβ) pathogenesis with synaptic loss in Alzheimer's disease (AD) have thus far been limited to small numbers of postmortem studies. Aβ plaque burden is not well-correlated with indices of clinical severity or neurodegeneration-at least in the dementia stage-as deposition of Aβ reaches a ceiling. In this study, we examined in vivo the association between fibrillar Aβ deposition and synaptic density in early AD using positron emission tomography (PET). We hypothesized that global Aβ deposition would be more strongly inversely associated with hippocampal synaptic density in participants with amnestic mild cognitive impairment (aMCI; a stage of continued Aβ accumulation) compared to those with dementia (a stage of relative Aβ plateau). METHODS We measured SV2A binding ([11C]UCB-J) and Aβ deposition ([11C]PiB) in 14 participants with aMCI due to AD and 24 participants with mild AD dementia. Distribution volume ratios (DVR) with a cerebellar reference region were calculated for both tracers to investigate the association between global Aβ deposition and SV2A binding in hippocampus. Exploratory analyses examined correlations between both global and regional Aβ deposition and SV2A binding across a broad range of brain regions using both ROI- and surface-based approaches. RESULTS We observed a significant inverse association between global Aβ deposition and hippocampal SV2A binding in participants with aMCI (r = - 0.55, P = 0.04), but not mild dementia (r = 0.05, P = 0.82; difference statistically significant by Fisher z = - 1.80, P = 0.04). Exploratory analyses across other ROIs and whole brain analyses demonstrated no broad or consistent associations between global Aβ deposition and regional SV2A binding in either diagnostic group. ROI-based analyses of the association between regional Aβ deposition and SV2A binding also revealed no consistent pattern but suggested a "paradoxical" positive association between local Aβ deposition and SV2A binding in the hippocampus. CONCLUSIONS Our findings lend support to a model in which fibrillar Aβ is still accumulating in the early stages of clinical disease but approaching a relative plateau, a point at which Aβ may uncouple from neurodegenerative processes including synaptic loss. Future research should investigate the relationship between Aβ deposition and synaptic loss in larger cohorts beginning preclinically and followed longitudinally in conjunction with other biomarkers.
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Affiliation(s)
- Ryan S. O’Dell
- Alzheimer’s Disease Research Unit, Yale University School of Medicine, One Church Street, 8th Floor, New Haven, CT 06510 USA
- Department of Psychiatry, Yale University School of Medicine, 300 George Street, New Haven, CT 06510 USA
| | - Adam P. Mecca
- Alzheimer’s Disease Research Unit, Yale University School of Medicine, One Church Street, 8th Floor, New Haven, CT 06510 USA
- Department of Psychiatry, Yale University School of Medicine, 300 George Street, New Haven, CT 06510 USA
| | - Ming-Kai Chen
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, P.O. Box 208048, New Haven, CT 06520 USA
| | - Mika Naganawa
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, P.O. Box 208048, New Haven, CT 06520 USA
| | - Takuya Toyonaga
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, P.O. Box 208048, New Haven, CT 06520 USA
| | - Yihuan Lu
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, P.O. Box 208048, New Haven, CT 06520 USA
| | - Tyler A. Godek
- Alzheimer’s Disease Research Unit, Yale University School of Medicine, One Church Street, 8th Floor, New Haven, CT 06510 USA
- Department of Psychiatry, Yale University School of Medicine, 300 George Street, New Haven, CT 06510 USA
| | - Joanna E. Harris
- Alzheimer’s Disease Research Unit, Yale University School of Medicine, One Church Street, 8th Floor, New Haven, CT 06510 USA
- Department of Psychiatry, Yale University School of Medicine, 300 George Street, New Haven, CT 06510 USA
| | - Hugh H. Bartlett
- Alzheimer’s Disease Research Unit, Yale University School of Medicine, One Church Street, 8th Floor, New Haven, CT 06510 USA
- Department of Psychiatry, Yale University School of Medicine, 300 George Street, New Haven, CT 06510 USA
| | - Emmie R. Banks
- Alzheimer’s Disease Research Unit, Yale University School of Medicine, One Church Street, 8th Floor, New Haven, CT 06510 USA
- Department of Psychiatry, Yale University School of Medicine, 300 George Street, New Haven, CT 06510 USA
| | - Victoria L. Kominek
- Alzheimer’s Disease Research Unit, Yale University School of Medicine, One Church Street, 8th Floor, New Haven, CT 06510 USA
- Department of Psychiatry, Yale University School of Medicine, 300 George Street, New Haven, CT 06510 USA
| | - Wenzhen Zhao
- Alzheimer’s Disease Research Unit, Yale University School of Medicine, One Church Street, 8th Floor, New Haven, CT 06510 USA
- Department of Psychiatry, Yale University School of Medicine, 300 George Street, New Haven, CT 06510 USA
| | - Nabeel B. Nabulsi
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, P.O. Box 208048, New Haven, CT 06520 USA
| | - Jim Ropchan
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, P.O. Box 208048, New Haven, CT 06520 USA
| | - Yunpeng Ye
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, P.O. Box 208048, New Haven, CT 06520 USA
| | - Brent C. Vander Wyk
- Program on Aging, Yale University School of Medicine, P.O. Box 207900, New Haven, CT 06520 USA
| | - Yiyun Huang
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, P.O. Box 208048, New Haven, CT 06520 USA
| | - Amy F. T. Arnsten
- Department of Neuroscience, Yale University School of Medicine, P.O. Box 208001, New Haven, CT 06520 USA
| | - Richard E. Carson
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, P.O. Box 208048, New Haven, CT 06520 USA
| | - Christopher H. van Dyck
- Alzheimer’s Disease Research Unit, Yale University School of Medicine, One Church Street, 8th Floor, New Haven, CT 06510 USA
- Department of Psychiatry, Yale University School of Medicine, 300 George Street, New Haven, CT 06510 USA
- Department of Neuroscience, Yale University School of Medicine, P.O. Box 208001, New Haven, CT 06520 USA
- Department of Neurology, Yale University School of Medicine, P.O. Box 208018, New Haven, CT 06520 USA
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Holland N, Jones PS, Savulich G, Wiggins JK, Hong YT, Fryer TD, Manavaki R, Sephton SM, Boros I, Malpetti M, Hezemans FH, Aigbirhio FI, Coles JP, O’Brien J, Rowe JB. Synaptic Loss in Primary Tauopathies Revealed by [ 11 C]UCB-J Positron Emission Tomography. Mov Disord 2020; 35:1834-1842. [PMID: 32652635 PMCID: PMC7611123 DOI: 10.1002/mds.28188] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Revised: 05/26/2020] [Accepted: 06/08/2020] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND Synaptic loss is a prominent and early feature of many neurodegenerative diseases. OBJECTIVES We tested the hypothesis that synaptic density is reduced in the primary tauopathies of progressive supranuclear palsy (PSP) (Richardson's syndrome) and amyloid-negative corticobasal syndrome (CBS). METHODS Forty-four participants (15 CBS, 14 PSP, and 15 age-/sex-/education-matched controls) underwent PET with the radioligand [11 C]UCB-J, which binds to synaptic vesicle glycoprotein 2A, a marker of synaptic density; participants also had 3 Tesla MRI and clinical and neuropsychological assessment. RESULTS Nine CBS patients had negative amyloid biomarkers determined by [11 C]PiB PET and hence were deemed likely to have corticobasal degeneration (CBD). Patients with PSP-Richardson's syndrome and amyloid-negative CBS were impaired in executive, memory, and visuospatial tasks. [11 C]UCB-J binding was reduced across frontal, temporal, parietal, and occipital lobes, cingulate, hippocampus, insula, amygdala, and subcortical structures in both PSP and CBD patients compared to controls (P < 0.01), with median reductions up to 50%, consistent with postmortem data. Reductions of 20% to 30% were widespread even in areas of the brain with minimal atrophy. There was a negative correlation between global [11 C]UCB-J binding and the PSP and CBD rating scales (R = -0.61, P < 0.002; R = -0.72, P < 0.001, respectively) and a positive correlation with the revised Addenbrooke's Cognitive Examination (R = 0.52; P = 0.01). CONCLUSIONS We confirm severe synaptic loss in PSP and CBD in proportion to disease severity, providing critical insight into the pathophysiology of primary degenerative tauopathies. [11 C]UCB-J may facilitate treatment strategies for disease-modification, synaptic maintenance, or restoration. © 2020 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.
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Affiliation(s)
- Negin Holland
- Department of Clinical Neurosciences, University of Cambridge
| | - P. Simon Jones
- Department of Clinical Neurosciences, University of Cambridge
| | | | | | - Young T. Hong
- Department of Clinical Neurosciences, University of Cambridge
- Wolfson Brain Imaging Centre, University of Cambridge
| | - Tim D. Fryer
- Department of Clinical Neurosciences, University of Cambridge
- Wolfson Brain Imaging Centre, University of Cambridge
| | | | - Selena Milicevic Sephton
- Department of Clinical Neurosciences, University of Cambridge
- Wolfson Brain Imaging Centre, University of Cambridge
| | - Istvan Boros
- Department of Clinical Neurosciences, University of Cambridge
- Wolfson Brain Imaging Centre, University of Cambridge
| | - Maura Malpetti
- Department of Clinical Neurosciences, University of Cambridge
| | - Frank H. Hezemans
- Department of Clinical Neurosciences, University of Cambridge
- Medical Research Council Cognition and Brain Sciences Unit, University of Cambridge
| | | | - Jonathan P. Coles
- Division of Anaesthesia, Department of Medicine, University of Cambridge
- Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK
| | - John O’Brien
- Department of Psychiatry, University of Cambridge
- Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK
| | - James B. Rowe
- Department of Clinical Neurosciences, University of Cambridge
- Medical Research Council Cognition and Brain Sciences Unit, University of Cambridge
- Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK
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28
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Kneppe K, Czell D. [Brivaracetam-A good alternative for the treatment of muscle cramps]. DER NERVENARZT 2020; 91:1130-1133. [PMID: 32990789 DOI: 10.1007/s00115-020-01001-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 08/07/2020] [Indexed: 11/30/2022]
Abstract
BACKGROUND Muscle cramps are suddenly occurring involuntary, mostly painful contractions of a single muscle, rarely of a muscle group. They can be idiopathic or occur in various neuromuscular diseases and can sometimes substantially impair the quality of life due to the frequency and strength. Only a few drugs are available for the effective treatment of cramps. RESULTS In this case series we report on five patients with cramps of different origin who responded well to treatment with brivaracetam. DISCUSSION Brivaracetam is actually used for the treatment of epileptic seizures. It binds to the synaptic vesicle protein 2A (SV2A), which also occurs in nerves and nerve roots. The SV2A regulates the exocytotic release of neurotransmitters, which could explain the effect of brivaracetam on muscle cramps. CONCLUSION Further studies are needed to demonstrate the effect of brivaracetam on muscle cramps.
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Affiliation(s)
- Katharina Kneppe
- Department of Medicine, Neurology, Spital Linth, Uznach, Schweiz
| | - David Czell
- Department of Medicine, Neurology, Spital Linth, Uznach, Schweiz.
- Neurologen am Zürichsee, Spital Männedorf, Asylstraße 10, 8708, Männedorf, Schweiz.
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29
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Bertoglio D, Verhaeghe J, Miranda A, Kertesz I, Cybulska K, Korat Š, Wyffels L, Stroobants S, Mrzljak L, Dominguez C, Liu L, Skinbjerg M, Munoz-Sanjuan I, Staelens S. Validation and noninvasive kinetic modeling of [ 11C]UCB-J PET imaging in mice. J Cereb Blood Flow Metab 2020; 40:1351-1362. [PMID: 31307287 PMCID: PMC7232782 DOI: 10.1177/0271678x19864081] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Synaptic pathology is associated with several brain disorders, thus positron emission tomography (PET) imaging of synaptic vesicle glycoprotein 2A (SV2A) using the radioligand [11C]UCB-J may provide a tool to measure synaptic alterations. Given the pivotal role of mouse models in understanding neuropsychiatric and neurodegenerative disorders, this study aims to validate and characterize [11C]UCB-J in mice. We performed a blocking study to verify the specificity of the radiotracer to SV2A, examined kinetic models using an image-derived input function (IDIF) for quantification of the radiotracer, and investigated the in vivo metabolism. Regional TACs during baseline showed rapid uptake of [11C]UCB-J into the brain. Pretreatment with levetiracetam confirmed target engagement in a dose-dependent manner. VT (IDIF) values estimated with one- and two-tissue compartmental models (1TCM and 2TCM) were highly comparable (r=0.999, p < 0.0001), with 1TCM performing better than 2TCM for K1 (IDIF). A scan duration of 60 min was sufficient for reliable VT (IDIF) and K1 (IDIF) estimations. In vivo metabolism of [11C]UCB-J was relatively rapid, with a parent fraction of 22.5 ± 4.2% at 15 min p.i. In conclusion, our findings show that [11C]UCB-J selectively binds to SV2A with optimal kinetics in the mouse representing a promising tool to noninvasively quantify synaptic density in comparative or therapeutic studies in neuropsychiatric and neurodegenerative disorder models.
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Affiliation(s)
- Daniele Bertoglio
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Wilrijk, Belgium
| | - Jeroen Verhaeghe
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Wilrijk, Belgium
| | - Alan Miranda
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Wilrijk, Belgium
| | - Istvan Kertesz
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Wilrijk, Belgium.,Department of Nuclear Medicine, Antwerp University Hospital, Edegem, Belgium
| | - Klaudia Cybulska
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Wilrijk, Belgium.,Department of Nuclear Medicine, Antwerp University Hospital, Edegem, Belgium
| | - Špela Korat
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Wilrijk, Belgium.,Department of Nuclear Medicine, Antwerp University Hospital, Edegem, Belgium
| | - Leonie Wyffels
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Wilrijk, Belgium.,Department of Nuclear Medicine, Antwerp University Hospital, Edegem, Belgium
| | - Sigrid Stroobants
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Wilrijk, Belgium.,Department of Nuclear Medicine, Antwerp University Hospital, Edegem, Belgium
| | | | | | - Longbin Liu
- CHDI Management/CHDI Foundation, Los Angeles, CA, USA
| | | | | | - Steven Staelens
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Wilrijk, Belgium
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30
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Serrano ME, Bahri MA, Becker G, Seret A, Mievis F, Giacomelli F, Lemaire C, Salmon E, Luxen A, Plenevaux A. Quantification of [ 18F]UCB-H Binding in the Rat Brain: From Kinetic Modelling to Standardised Uptake Value. Mol Imaging Biol 2020; 21:888-897. [PMID: 30460626 DOI: 10.1007/s11307-018-1301-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
PURPOSE [18F]UCB-H is a specific positron emission tomography (PET) biomarker for the Synaptic Vesicle protein 2A (SV2A), the binding site of the antiepileptic drug levetiracetam. With a view to optimising acquisition time and simplifying data analysis with this radiotracer, we compared two parameters: the distribution volume (Vt) obtained from Logan graphical analysis using a Population-Based Input Function, and the Standardised Uptake Value (SUV). PROCEDURES Twelve Sprague Dawley male rats, pre-treated with three different doses of levetiracetam were employed to develop the methodology. Three additional kainic acid (KA) treated rats (temporal lobe epilepsy model) were also used to test the procedure. Image analyses focused on: (i) length of the dynamic acquisition (90 versus 60 min); (ii) correlations between Vt and SUV over 20-min consecutive time-frames; (iii) and (iv) evaluation of differences between groups using the Vt and the SUV; and (v) preliminary evaluation of the methodology in the KA epilepsy model. RESULTS A large correlation between the Vt issued from 60 to 90-min acquisitions was observed. Further analyses highlighted a large correlation (r > 0.8) between the Vt and the SUV. Equivalent differences between groups were detected for both parameters, especially in the 20-40 and 40-60-min time-frames. The same results were also obtained with the epilepsy model. CONCLUSIONS Our results enable the acquisition setting to be changed from a 90-min dynamic to a 20-min static PET acquisition. According to a better image quality, the 20-40-min time-frame appears optimal. Due to its equivalence to the Vt, the SUV parameter can be considered in order to quantify [18F]UCB-H uptake in the rat brain. This work, therefore, establishes a starting point for the simplification of SV2A in vivo quantification with [18F]UCB-H, and represents a step forward to the clinical application of this PET radiotracer.
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Affiliation(s)
- Maria Elisa Serrano
- GIGA - CRC In Vivo Imaging, University of Liège, Allée du 6 Août, Building B30, Sart Tilman, 4000, Liège, Belgium.
| | - Mohamed Ali Bahri
- GIGA - CRC In Vivo Imaging, University of Liège, Allée du 6 Août, Building B30, Sart Tilman, 4000, Liège, Belgium
| | - Guillaume Becker
- GIGA - CRC In Vivo Imaging, University of Liège, Allée du 6 Août, Building B30, Sart Tilman, 4000, Liège, Belgium
| | - Alain Seret
- GIGA - CRC In Vivo Imaging, University of Liège, Allée du 6 Août, Building B30, Sart Tilman, 4000, Liège, Belgium
| | - Frédéric Mievis
- Nucleis, University of Liège, Allée du 6 Août, Building B30, Sart Tilman, 4000, Liège, Belgium
| | - Fabrice Giacomelli
- Nucleis, University of Liège, Allée du 6 Août, Building B30, Sart Tilman, 4000, Liège, Belgium
| | - Christian Lemaire
- GIGA - CRC In Vivo Imaging, University of Liège, Allée du 6 Août, Building B30, Sart Tilman, 4000, Liège, Belgium
| | - Eric Salmon
- GIGA - CRC In Vivo Imaging, University of Liège, Allée du 6 Août, Building B30, Sart Tilman, 4000, Liège, Belgium
| | - André Luxen
- GIGA - CRC In Vivo Imaging, University of Liège, Allée du 6 Août, Building B30, Sart Tilman, 4000, Liège, Belgium
| | - Alain Plenevaux
- GIGA - CRC In Vivo Imaging, University of Liège, Allée du 6 Août, Building B30, Sart Tilman, 4000, Liège, Belgium
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31
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Mecca AP, Chen MK, O'Dell RS, Naganawa M, Toyonaga T, Godek TA, Harris JE, Bartlett HH, Zhao W, Nabulsi NB, Wyk BCV, Varma P, Arnsten AFT, Huang Y, Carson RE, van Dyck CH. In vivo measurement of widespread synaptic loss in Alzheimer's disease with SV2A PET. Alzheimers Dement 2020; 16:974-982. [PMID: 32400950 PMCID: PMC7383876 DOI: 10.1002/alz.12097] [Citation(s) in RCA: 155] [Impact Index Per Article: 38.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Revised: 02/18/2020] [Accepted: 03/02/2020] [Indexed: 12/18/2022]
Abstract
Introduction Synaptic loss is a robust and consistent pathology in Alzheimer's disease (AD) and the major structural correlate of cognitive impairment. Positron emission tomography (PET) imaging of synaptic vesicle glycoprotein 2A (SV2A) has emerged as a promising biomarker of synaptic density. Methods We measured SV2A binding in 34 participants with early AD and 19 cognitively normal (CN) participants using [11C]UCB‐J PET and a cerebellar reference region for calculation of the distribution volume ratio. Results We observed widespread reductions of SV2A binding in medial temporal and neocortical brain regions in early AD compared to CN participants. These reductions were largely maintained after correction for volume loss and were more extensive than decreases in gray matter volume. Conclusion We were able to measure widespread synaptic loss due to AD using [11C]UCB‐J PET. Future studies will continue to evaluate the utility of SV2A PET for tracking AD progression and for monitoring potential therapies.
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Affiliation(s)
- Adam P Mecca
- Alzheimer's Disease Research Unit, Yale University School of Medicine, New Haven, Connecticut.,Department of Psychiatry, Yale University School of Medicine, New Haven, Connecticut
| | - Ming-Kai Chen
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, Connecticut.,Department of Neuroscience, Yale University School of Medicine, New Haven, Connecticut
| | - Ryan S O'Dell
- Alzheimer's Disease Research Unit, Yale University School of Medicine, New Haven, Connecticut.,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
| | - Takuya Toyonaga
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, Connecticut
| | - Tyler A Godek
- Alzheimer's Disease Research Unit, Yale University School of Medicine, New Haven, Connecticut.,Department of Psychiatry, Yale University School of Medicine, New Haven, Connecticut
| | - Joanna E Harris
- Alzheimer's Disease Research Unit, Yale University School of Medicine, New Haven, Connecticut.,Department of Psychiatry, Yale University School of Medicine, New Haven, Connecticut
| | - Hugh H Bartlett
- Alzheimer's Disease Research Unit, Yale University School of Medicine, New Haven, Connecticut.,Department of Psychiatry, Yale University School of Medicine, New Haven, Connecticut
| | - Wenzhen Zhao
- Alzheimer's Disease Research Unit, Yale University School of Medicine, New Haven, Connecticut.,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
| | - Brent C Vander Wyk
- Program on Aging, Yale University School of Medicine, New Haven, Connecticut
| | - Pradeep Varma
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, Connecticut
| | - Amy F T Arnsten
- Department of Neuroscience, 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
| | - Christopher H van Dyck
- Alzheimer's Disease Research Unit, Yale University School of Medicine, New Haven, Connecticut.,Department of Psychiatry, Yale University School of Medicine, New Haven, Connecticut.,Department of Neuroscience, Yale University School of Medicine, New Haven, Connecticut.,Department of Neurology, Yale University School of Medicine, New Haven, Connecticut
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32
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Development and In Vivo Preclinical Imaging of Fluorine-18-Labeled Synaptic Vesicle Protein 2A (SV2A) PET Tracers. Mol Imaging Biol 2020; 21:509-518. [PMID: 30084043 DOI: 10.1007/s11307-018-1260-5] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
PURPOSE Synaptic vesicle protein 2A (SV2A) serves as a biomarker of synaptic density and positron emission tomography (PET) imaging of SV2A could provide a tool to assess progression of neurodegenerative diseases. Two tracers have primarily been reported and characterized in vivo: [11C]UCB-J and [18F]UCB-H. In early human studies, [11C]UCB-J showed promising results, while its F-18-labeled analogue [18F]UCB-H showed suboptimal specific signal in comparison to [11C]UCB-J. Considering the limited use of [11C]UCB-J to facilities with a cyclotron, having a F-18 variant would facilitate large, multicenter imaging trials. We have screened several F-18 derivatives of UCB-J in non-human primates and identified a promising F-18 PET candidate, [18F]MNI-1126, with additional investigations of the racemate [18F]MNI-1038, affording a signal comparable to [11C]UCB-J. PROCEDURES F-18 derivatives of UCB-J and UCB-H were synthesized and administered to non-human primates for microPET imaging. Following screenings, [18F]MNI-1038 (racemate) and [18F]MNI-1126 (R-enantiomer) were identified with the highest signal and favorable kinetics and were selected for further imaging. Kinetic modeling with one- and two-tissue compartmental models, and linear methods were applied to PET data using metabolite-corrected arterial input function. Pre-block scans with levetiracetam (LEV, 10, 30 mg/kg, iv) were performed to determine the tracers' in vivo specificity for SV2A. Two whole-body PET studies were performed with [18F]MNI-1038 in one male and one female rhesus, and radiation absorbed dose estimates and effective dose (ED, ICRP-103) were estimated with OLINDA/EXM 2.0. RESULTS All compounds screened displayed very good brain penetration, with a plasma-free fraction of ~ 40 %. [18F]MNI-1126 and [18F]MNI-1038 showed uptake and distribution the most consistent with UCB-J, while the other derivatives showed suboptimal results, with similar or lower uptake than [18F]UCB-H. VT of [18F]MNI-1126 and [18F]MNI-1038 was high in all gray matter regions (within animal averages ~ 30 ml/cm3) and highly correlated with [11C]UCB-J (r > 0.99). Pre-blocking of [18F]MNI-1126 or [18F]MNI-1038 with LEV showed robust occupancy across all gray matter regions, similar to that reported with [11C]UCB-J (~ 85 % at 30 mg/kg, ~ 65 % at 10 mg/kg). Using the centrum semiovale as a reference region, BPND of [18F]MNI-1126 reached values of up to ~ 30 to 40 % higher than those reported for [11C]UCB-J. From whole-body imaging average ED of [18F]MNI-1038 was estimated to be 22.3 μSv/MBq, with tracer being eliminated via both urinary and hepatobiliary pathways. CONCLUSIONS We have identified a F-18-labeled tracer ([18F]MNI-1126) that exhibits comparable in vivo characteristics and specificity for SV2A to [11C]UCB-J in non-human primates, which makes [18F]MNI-1126 a promising PET radiotracer for imaging SV2A in human trials.
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Matuskey D, Tinaz S, Wilcox KC, Naganawa M, Toyonaga T, Dias M, Henry S, Pittman B, Ropchan J, Nabulsi N, Suridjan I, Comley RA, Huang Y, Finnema SJ, Carson RE. Synaptic Changes in Parkinson Disease Assessed with in vivo Imaging. Ann Neurol 2020; 87:329-338. [PMID: 31953875 PMCID: PMC7065227 DOI: 10.1002/ana.25682] [Citation(s) in RCA: 102] [Impact Index Per Article: 25.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Revised: 01/13/2020] [Accepted: 01/14/2020] [Indexed: 01/01/2023]
Abstract
OBJECTIVE Parkinson disease is characterized by motor and nonmotor symptoms, reduced striatal dopamine signaling, and loss of dopamine neurons in the substantia nigra. It is now known that the pathological process in Parkinson disease may begin decades before the clinical diagnosis and include a variety of neuronal alterations in addition to the dopamine system. METHODS This study examined the density of all synapses with synaptic vesicle glycoprotein 2A (SV2A) in Parkinson disease subjects with mild bilateral disease (n = 12) and matched normal controls (n = 12) using in vivo high-resolution positron emission tomographic imaging as well as postmortem autoradiography in an independent sample with Parkinson disease (n = 15) and normal controls (n = 13) in the substantia nigra and putamen. RESULTS A group-by-brain region interaction effect (F10, 22 = 3.52, p = 0.007) was observed in the primary brain areas with in vivo SV2A binding. Post hoc analyses revealed that the Parkinson disease group exhibited lower SV2A in the substantia nigra (-45%; p < 0.001), red nucleus (-31%; p = 0.03), and locus coeruleus (-17%; p = 0.03). Exploratory analyses also revealed lower SV2A binding in clinically relevant cortical areas. Using autoradiography, we confirmed lower SV2A in the substantia nigra (-17%; p < 0.005) and nonsignificant findings in the putamen (-4%; p = 0.06). INTERPRETATION This work provides the first evidence of synaptic loss in brainstem nuclei involved in the pathogenesis of Parkinson disease in living patients. SV2A imaging holds promise for understanding synaptic changes central to the disease. Ann Neurol 2020;87:329-338.
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Affiliation(s)
- David Matuskey
- Positron Emission Tomography Research Center, Department of Radiology and Biomedical ImagingYale UniversityNew HavenCT
- Department of PsychiatryYale UniversityNew HavenCT
- Department of NeurologyYale UniversityNew HavenCT
| | - Sule Tinaz
- Department of NeurologyYale UniversityNew HavenCT
| | - Kyle C. Wilcox
- Translational ImagingIntegrated Science and TechnologyAbbVieNorth ChicagoIL
| | - Mika Naganawa
- Positron Emission Tomography Research Center, Department of Radiology and Biomedical ImagingYale UniversityNew HavenCT
| | - Takuya Toyonaga
- Positron Emission Tomography Research Center, Department of Radiology and Biomedical ImagingYale UniversityNew HavenCT
| | - Mark Dias
- Positron Emission Tomography Research Center, Department of Radiology and Biomedical ImagingYale UniversityNew HavenCT
| | - Shannan Henry
- Positron Emission Tomography Research Center, Department of Radiology and Biomedical ImagingYale UniversityNew HavenCT
| | | | - Jim Ropchan
- Positron Emission Tomography Research Center, Department of Radiology and Biomedical ImagingYale UniversityNew HavenCT
| | - Nabeel Nabulsi
- Positron Emission Tomography Research Center, Department of Radiology and Biomedical ImagingYale UniversityNew HavenCT
| | - Ivonne Suridjan
- Translational ImagingIntegrated Science and TechnologyAbbVieNorth ChicagoIL
| | - Robert A. Comley
- Translational ImagingIntegrated Science and TechnologyAbbVieNorth ChicagoIL
| | - Yiyun Huang
- Positron Emission Tomography Research Center, Department of Radiology and Biomedical ImagingYale UniversityNew HavenCT
| | - Sjoerd J. Finnema
- Positron Emission Tomography Research Center, Department of Radiology and Biomedical ImagingYale UniversityNew HavenCT
- Translational ImagingIntegrated Science and TechnologyAbbVieNorth ChicagoIL
| | - Richard E. Carson
- Positron Emission Tomography Research Center, Department of Radiology and Biomedical ImagingYale UniversityNew HavenCT
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Makinde HM, Winter DR, Procissi D, Mike EV, Stock AD, Kando MJ, Gadhvi GT, Droho S, Bloomfield CL, Dominguez ST, Mayr MG, Lavine JA, Putterman C, Cuda CM. A Novel Microglia-Specific Transcriptional Signature Correlates With Behavioral Deficits in Neuropsychiatric Lupus. Front Immunol 2020; 11:230. [PMID: 32174913 PMCID: PMC7055359 DOI: 10.3389/fimmu.2020.00230] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Accepted: 01/28/2020] [Indexed: 12/14/2022] Open
Abstract
Neuropsychiatric symptoms of systemic lupus erythematosus (NP-SLE) affect over one-half of SLE patients, yet underlying mechanisms remain largely unknown. We demonstrate that SLE-prone mice (CReCOM) develop NP-SLE, including behavioral deficits prior to systemic autoimmunity, reduced brain volumes, decreased vascular integrity, and brain-infiltrating leukocytes. NP-SLE microglia exhibit numerical expansion, increased synaptic uptake, and a more metabolically active phenotype. Microglia from multiple SLE-prone models express a "NP-SLE signature" unrelated to type I interferon. Rather, the signature is associated with lipid metabolism, scavenger receptor activity and downregulation of inflammatory and chemotaxis processes, suggesting a more regulatory, anti-inflammatory profile. NP-SLE microglia also express genes associated with disease-associated microglia (DAM), a subset of microglia thought to be instrumental in neurodegenerative diseases. Further, expression of "NP-SLE" and "DAM" signatures correlate with the severity of behavioral deficits in young SLE-prone mice prior to overt systemic disease. Our data are the first to demonstrate the predictive value of our newly identified microglia-specific "NP-SLE" and "DAM" signatures as a surrogate for NP-SLE clinical outcomes and suggests that microglia-intrinsic defects precede contributions from systemic SLE for neuropsychiatric manifestations.
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Affiliation(s)
- Hadijat M Makinde
- Division of Rheumatology, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
| | - Deborah R Winter
- Division of Rheumatology, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
| | - Daniele Procissi
- Department of Radiology, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
| | - Elise V Mike
- Division of Rheumatology, Department of Medicine, Albert Einstein College of Medicine, The Bronx, NY, United States
| | - Ariel D Stock
- Division of Rheumatology, Department of Medicine, Albert Einstein College of Medicine, The Bronx, NY, United States
| | - Mary J Kando
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
| | - Gaurav T Gadhvi
- Division of Rheumatology, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
| | - Steven Droho
- Department of Ophthalmology, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
| | - Christina L Bloomfield
- Division of Rheumatology, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
| | - Salina T Dominguez
- Division of Rheumatology, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
| | - Maximilian G Mayr
- Division of Rheumatology, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
| | - Jeremy A Lavine
- Department of Ophthalmology, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
| | - Chaim Putterman
- Division of Rheumatology, Department of Medicine, Albert Einstein College of Medicine, The Bronx, NY, United States.,Research Division, Azrieli Faculty of Medicine and Galilee Medical Center, Nahariya, Israel
| | - Carla M Cuda
- Division of Rheumatology, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
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Wood M, Daniels V, Provins L, Wolff C, Kaminski RM, Gillard M. Pharmacological Profile of the Novel Antiepileptic Drug Candidate Padsevonil: Interactions with Synaptic Vesicle 2 Proteins and the GABAA Receptor. J Pharmacol Exp Ther 2019; 372:1-10. [DOI: 10.1124/jpet.119.261149] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Accepted: 10/10/2019] [Indexed: 11/22/2022] Open
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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: 271] [Impact Index Per Article: 54.2] [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.
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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
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Analysis of Differential Expression of Synaptic Vesicle Protein 2A in the Adult Rat Brain. Neuroscience 2019; 419:108-120. [PMID: 31520710 DOI: 10.1016/j.neuroscience.2019.09.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Accepted: 09/05/2019] [Indexed: 01/02/2023]
Abstract
Synaptic vesicle protein 2A (SV2A), which plays an important role in the pathophysiology of epilepsy, is a unique vesicular protein recognized as a pharmacological target of anticonvulsant drugs. Furthermore, SV2A is a potential synaptic density marker, as it is ubiquitously expressed throughout the brain in all nerve terminals independently of their neurotransmitter content. Due to the growing interest in this protein, we thoroughly analyzed SV2A levels, expression patterns and colocalization in both excitatory and inhibitory synapses among different brain structures in healthy rats. In addition, we discuss the main semiquantitative methodologies used to study SV2A because these techniques might represent powerful tools for evaluating synaptic changes associated with brain disorders. Our results showed that the SV2A expression levels differed among the analyzed structures, and a positive correlation between the SV2A mRNA copy number and protein level was observed by Western blot. In addition, immunohistochemistry demonstrated slight but consistent asymmetrical SV2A levels in different laminated structures, and SV2A expression was increased by up to 40% in some specific layers compared to that in others. Finally, triple immunofluorescence revealed strong SV2A colocalization with GABAergic terminals, mainly around the principal cells, suggesting that SV2A primarily participates in this inhibitory system in different rat brain structures. Although the SV2A protein is considered a good candidate marker of synaptic density, our data show that changes in its expression in pathological processes must be viewed as not only increased or decreased synapse numbers but also in light of the type of neurotransmission being affected.
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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.
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The neurobiological basis for novel experimental therapeutics in dystonia. Neurobiol Dis 2019; 130:104526. [PMID: 31279827 DOI: 10.1016/j.nbd.2019.104526] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Revised: 06/13/2019] [Accepted: 07/03/2019] [Indexed: 12/17/2022] Open
Abstract
Dystonia is a movement disorder characterized by involuntary muscle contractions, twisting movements, and abnormal postures that may affect one or multiple body regions. Dystonia is the third most common movement disorder after Parkinson's disease and essential tremor. Despite its relative frequency, small molecule therapeutics for dystonia are limited. Development of new therapeutics is further hampered by the heterogeneity of both clinical symptoms and etiologies in dystonia. Recent advances in both animal and cell-based models have helped clarify divergent etiologies in dystonia and have facilitated the identification of new therapeutic targets. Advances in medicinal chemistry have also made available novel compounds for testing in biochemical, physiological, and behavioral models of dystonia. Here, we briefly review motor circuit anatomy and the anatomical and functional abnormalities in dystonia. We then discuss recently identified therapeutic targets in dystonia based on recent preclinical animal studies and clinical trials investigating novel therapeutics.
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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.
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Ciruelas K, Marcotulli D, Bajjalieh SM. Synaptic vesicle protein 2: A multi-faceted regulator of secretion. Semin Cell Dev Biol 2019; 95:130-141. [PMID: 30826548 DOI: 10.1016/j.semcdb.2019.02.003] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Revised: 01/11/2019] [Accepted: 02/21/2019] [Indexed: 01/01/2023]
Abstract
Synaptic Vesicle Protein 2 (SV2) comprises a recently evolved family of proteins unique to secretory vesicles that undergo calcium-regulated exocytosis. In this review we consider SV2s' structural features, evolution, and function and discuss its therapeutic potential as the receptors for an expanding class of drugs used to treat epilepsy and cognitive decline.
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Affiliation(s)
- Kristine Ciruelas
- Department of Pharmacology, University of Washington, Seattle, WA, United States
| | - Daniele Marcotulli
- Department of Pharmacology, University of Washington, Seattle, WA, United States
| | - Sandra M Bajjalieh
- Department of Pharmacology, University of Washington, Seattle, WA, United States.
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Differential expression of SV2A in hippocampal glutamatergic and GABAergic terminals during postnatal development. Brain Res 2019; 1715:73-83. [PMID: 30905653 DOI: 10.1016/j.brainres.2019.03.021] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Revised: 03/08/2019] [Accepted: 03/20/2019] [Indexed: 01/15/2023]
Abstract
The function of synaptic vesicle protein 2A (SV2A) has not been clearly identified, although it has an essential role in normal neurotransmission. Changes in SV2A expression have been linked to several diseases that could implicate an imbalance between excitation and inhibition, such as epilepsy. Although it is known that SV2A expression is necessary for survival, SV2A expression and its relationship with γ-aminobutyric acid (GABA) and glutamate neurotransmitter systems along development has not been addressed. This report follows SV2A expression levels in the rat hippocampus and their association with glutamatergic and GABAergic terminals along postnatal development. Total SV2A expression was assessed by real time PCR and western blot, while immunofluorescence was used to identify SV2A protein in the different hippocampal layers and its co-localization with GABA or glutamate vesicular transporters. SV2A was dynamically regulated along development and its association with GABA or glutamate transporters varied in the different hippocampal layers. In the principal cells layers (granular and pyramidal), SV2A protein was preferentially localized to GABAergic terminals, while in the hilus and stratum lucidum SV2A was associated mainly to glutamatergic terminals. Although SV2A was ubiquitously expressed in the entire hippocampus, it established a differential association with excitatory or inhibitory terminals, which could contribute to the maturation of excitatory/inhibitory balance.
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Tokudome K, Shimizu S, Serikawa T, Ohno Y. [Function of synaptic vesicle protein 2A (SV2A) as a novel therapeutic target for epilepsy]. Nihon Yakurigaku Zasshi 2018; 152:275-280. [PMID: 30531097 DOI: 10.1254/fpj.152.275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Epilepsy is a chronic neurologic disease characterized by recurrent seizures, affecting nearly 1% of the population. Synaptic vesicle protein 2A (SV2A) is a membrane protein specifically expressed in synaptic vesicles and is now implicated in the pathogenesis of epileptic disorders. This is because 1) Sv2a-knockout mice exhibit severe seizures, 2) SV2A serves as a specific binding site for certain antiepileptics (e.g., levetiracetam and its analogues) and 3) the SV2A expression changes under various epileptic conditions both in animals (e.g., kindling) and humans (e.g., intractable temporal lobe epilepsy and focal cortical dysplasia). Furthermore, it has been shown that a missense mutation in the SV2A gene caused intractable epilepsy, involuntary movements and developmental retardation, indicating a causative role of SV2A dysfunction in epilepsy. In order to explore the mechanism of SV2A in modulating development of epileptogenesis, we recently developed a novel rat model (Sv2aL174Q rat) carrying a missense mutation (Leu174Gln) in the Sv2a gene. These rats were highly susceptible to the kindling development associated with repeated pentylenetetrazole treatments or electrical stimulations of the amygdala. In addition, the Sv2aL174Q mutation specifically impaired depolarization-induced GABA, but not glutamate, release in the hippocampus and amygdala. All this evidence indicates that the SV2A-GABAergic system plays a crucial role in modulating epileptogenesis and encourages discovery research into the novel antiepileptic agents which enhance the function of the SV2A-GABA system.
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Affiliation(s)
- Kentaro Tokudome
- Department of Pharmacology, Osaka University of Pharmaceutical Sciences
| | - Saki Shimizu
- Department of Pharmacology, Osaka University of Pharmaceutical Sciences
| | - Tadao Serikawa
- Department of Pharmacology, Osaka University of Pharmaceutical Sciences
| | - Yukihiro Ohno
- Department of Pharmacology, Osaka University of Pharmaceutical Sciences
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Contreras-García IJ, Pichardo-Macías LA, Santana-Gómez CE, Sánchez-Huerta K, Ramírez-Hernández R, Gómez-González B, Rocha L, Mendoza Torreblanca JG. Differential expression of synaptic vesicle protein 2A after status epilepticus and during epilepsy in a lithium-pilocarpine model. Epilepsy Behav 2018; 88:283-294. [PMID: 30336420 DOI: 10.1016/j.yebeh.2018.08.023] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Revised: 07/04/2018] [Accepted: 08/17/2018] [Indexed: 11/25/2022]
Abstract
Synaptic vesicle protein 2A (SV2A) has become an attractive target of investigation because of its role in the pathophysiology of epilepsy; SV2A is expressed ubiquitously throughout the brain in all nerve terminals independently of their neurotransmitter content and plays an important but poorly defined role in neurotransmission. Previous studies have shown that modifications in the SV2A protein expression could be a direct consequence of disease severity. Furthermore, these SV2A modifications may depend on specific changes in the nerve tissue following the induction of epilepsy and might be present in both excitatory and inhibitory terminals. Thus, we evaluated SV2A protein expression throughout the hippocampi of lithium-pilocarpine rats after status epilepticus (SE) and during early and late epilepsy. In addition, we determined the γ-aminobutyric acid (GABA)ergic or glutamatergic nature associated with SV2A modifications. Wistar rats were treated with lithium-pilocarpine to induce SE and subsequently were shown to present spontaneous recurrent seizures (SRS). Later, we conducted an exhaustive semi-quantitative analysis of SV2A optical density (OD) throughout the hippocampus by immunohistochemistry. Levels of the SV2A protein were substantially increased in layers formed by principal neurons after SE, mainly because of GABAergic activity. No changes were observed in the early stage of epilepsy. In the late stage of epilepsy, there were minor changes in SV2A OD compared with the robust modifications of SE; however, SV2A protein expression generally showed an increment reaching significant differences in two dendritic layers and hilus, without clear modifications of GABAergic or glutamatergic systems. Our results suggest that the SV2A variations may depend on several factors, such as neuronal activity, and might appear in both excitatory and inhibitory systems depending on the epilepsy stage.
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Affiliation(s)
- Itzel Jatziri Contreras-García
- Instituto Nacional de Pediatría, Subdirección de Medicina experimental, Laboratorio de Neurociencias, México; Posgrado en Biología Experimental, Universidad Autónoma Metropolitana, Unidad Iztapalapa, México
| | - Luz Adriana Pichardo-Macías
- Instituto Nacional de Pediatría, Subdirección de Medicina experimental, Laboratorio de Neurociencias, México; Instituto Politécnico Nacional, Escuela Nacional de Ciencias Biológicas, Departamento de Fisiología, México
| | - César Emmanuel Santana-Gómez
- Centro de Investigación y de Estudios Avanzados, del Instituto Politécnico Nacional, Sede Sur México, Departamento de Farmacobiología
| | - Karla Sánchez-Huerta
- Instituto Nacional de Pediatría, Subdirección de Medicina experimental, Laboratorio de Neurociencias, México
| | - Rogelio Ramírez-Hernández
- Instituto Nacional de Pediatría, Subdirección de Medicina experimental, Laboratorio de Neurociencias, México
| | | | - Luisa Rocha
- Centro de Investigación y de Estudios Avanzados, del Instituto Politécnico Nacional, Sede Sur México, Departamento de Farmacobiología
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Antipova V, Wree A, Holzmann C, Mann T, Palomero-Gallagher N, Zilles K, Schmitt O, Hawlitschka A. Unilateral Botulinum Neurotoxin-A Injection into the Striatum of C57BL/6 Mice Leads to a Different Motor Behavior Compared with Rats. Toxins (Basel) 2018; 10:E295. [PMID: 30018211 PMCID: PMC6070800 DOI: 10.3390/toxins10070295] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Revised: 07/13/2018] [Accepted: 07/15/2018] [Indexed: 12/26/2022] Open
Abstract
Different morphological changes in the caudate-putamen (CPu) of naïve rats and mice were observed after intrastriatal botulinum neurotoxin-A (BoNT-A) injection. For this purpose we here studied various motor behaviors in mice (n = 46) longitudinally up to 9 months after intrastriatal BoNT-A administration as previously reported for rats, and compared both outcomes. Apomorphine- and amphetamine-induced rotational behavior, spontaneous motor behavior, as well as lateralized neglect were studied in mice after the injection of single doses of BoNT-A into the right CPu, comparing them with sham-injected animals. Unilateral intrastriatal injection of BoNT-A in mice induced significantly increased contralateral apomorphine-induced rotations for 1 to 3 months, as well as significantly increased contralateral amphetamine-induced rotations 1 to 9 months after injection. In rats (n = 28), unilateral BoNT-A injection also induced significantly increased contralateral apomorphine-induced rotations 3 months after injection, but did not provoke amphetamine-induced rotations at all. Lateralized sensorimotor integration, forelimb preference, and forelimb stepping were significantly impaired on the left side. The differences in motor behaviors between rats and mice may be caused by different BoNT-A effects on cholinergic and catecholaminergic fibers in rat and mouse striata, interspecies differences in striatal receptor densities, and different connectomes of the basal ganglia.
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Affiliation(s)
- Veronica Antipova
- Institute of Anatomy, Rostock University Medical Center, Gertrudenstrasse 9, D-18057 Rostock, Germany.
- Gottfried Schatz Research Center for Cell Signaling, Metabolism and Aging, Macroscopic and Clinical Anatomy, Medical University of Graz, Harrachgasse 21/1, A-8010 Graz, Austria.
| | - Andreas Wree
- Institute of Anatomy, Rostock University Medical Center, Gertrudenstrasse 9, D-18057 Rostock, Germany.
| | - Carsten Holzmann
- Institute of Medical Genetics, Rostock University Medical Center, Ernst-Heydemann-Strasse 8, D-18057 Rostock, Germany.
| | - Teresa Mann
- Institute of Anatomy, Rostock University Medical Center, Gertrudenstrasse 9, D-18057 Rostock, Germany.
| | - Nicola Palomero-Gallagher
- Institute of Neuroscience and Medicine INM-1, Research Center Jülich, D-52425 Jülich, Germany.
- Department of Psychiatry, Psychotherapy and Psychosomatics, Medical Faculty, RWTH Aachen, D-52062 Aachen, Germany.
| | - Karl Zilles
- Institute of Neuroscience and Medicine INM-1, Research Center Jülich, D-52425 Jülich, Germany.
- Department of Psychiatry, Psychotherapy and Psychosomatics, Medical Faculty, RWTH Aachen, D-52062 Aachen, Germany.
- JARA-Translational Brain Medicine, D-52062 Aachen, Germany.
| | - Oliver Schmitt
- Institute of Anatomy, Rostock University Medical Center, Gertrudenstrasse 9, D-18057 Rostock, Germany.
| | - Alexander Hawlitschka
- Institute of Anatomy, Rostock University Medical Center, Gertrudenstrasse 9, D-18057 Rostock, Germany.
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Johnston TH, Lacoste AMB, Visanji NP, Lang AE, Fox SH, Brotchie JM. Repurposing drugs to treat l-DOPA-induced dyskinesia in Parkinson's disease. Neuropharmacology 2018; 147:11-27. [PMID: 29907424 DOI: 10.1016/j.neuropharm.2018.05.035] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Revised: 05/29/2018] [Accepted: 05/31/2018] [Indexed: 01/05/2023]
Abstract
In this review, we discuss the opportunity for repurposing drugs for use in l-DOPA-induced dyskinesia (LID) in Parkinson's disease. LID is a particularly suitable indication for drug repurposing given its pharmacological diversity, translatability of animal-models, availability of Phase II proof-of-concept (PoC) methodologies and the indication-specific regulatory environment. A compound fit for repurposing is defined as one with appropriate human safety-data as well as animal safety, toxicology and pharmacokinetic data as found in an Investigational New Drug (IND) package for another indication. We first focus on how such repurposing candidates can be identified and then discuss development strategies that might progress such a candidate towards a Phase II clinical PoC. We discuss traditional means for identifying repurposing candidates and contrast these with newer approaches, especially focussing on the use of computational and artificial intelligence (AI) platforms. We discuss strategies that can be categorised broadly as: in vivo phenotypic screening in a hypothesis-free manner; in vivo phenotypic screening based on analogy to a related disorder; hypothesis-driven evaluation of candidates in vivo and in silico screening with a hypothesis-agnostic component to the selection. To highlight the power of AI approaches, we describe a case study using IBM Watson where a training set of compounds, with demonstrated ability to reduce LID, were employed to identify novel repurposing candidates. Using the approaches discussed, many diverse candidates for repurposing in LID, originally envisaged for other indications, will be described that have already been evaluated for efficacy in non-human primate models of LID and/or clinically. This article is part of the Special Issue entitled 'Drug Repurposing: old molecules, new ways to fast track drug discovery and development for CNS disorders'.
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Affiliation(s)
- Tom H Johnston
- Krembil Research Institute, University Health Network, Toronto, ON, Canada; Atuka Inc., Toronto, ON, Canada.
| | | | - Naomi P Visanji
- Edmund J Safra Movement Disorders Clinic, Division of Neurology, University of Toronto, Toronto Western Hospital, Toronto, ON, Canada
| | - Anthony E Lang
- Edmund J Safra Movement Disorders Clinic, Division of Neurology, University of Toronto, Toronto Western Hospital, Toronto, ON, Canada
| | - Susan H Fox
- Edmund J Safra Movement Disorders Clinic, Division of Neurology, University of Toronto, Toronto Western Hospital, Toronto, ON, Canada
| | - Jonathan M Brotchie
- Krembil Research Institute, University Health Network, Toronto, ON, Canada; Atuka Inc., Toronto, ON, Canada
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Caterson B, Melrose J. Keratan sulfate, a complex glycosaminoglycan with unique functional capability. Glycobiology 2018; 28:182-206. [PMID: 29340594 PMCID: PMC5993099 DOI: 10.1093/glycob/cwy003] [Citation(s) in RCA: 139] [Impact Index Per Article: 23.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2017] [Revised: 12/20/2017] [Accepted: 01/08/2018] [Indexed: 12/19/2022] Open
Abstract
From an evolutionary perspective keratan sulfate (KS) is the newest glycosaminoglycan (GAG) but the least understood. KS is a sophisticated molecule with a diverse structure, and unique functional roles continue to be uncovered for this GAG. The cornea is the richest tissue source of KS in the human body but the central and peripheral nervous systems also contain significant levels of KS and a diverse range of KS-proteoglycans with essential functional roles. KS also displays important cell regulatory properties in epithelial and mesenchymal tissues and in bone and in tumor development of diagnostic and prognostic utility. Corneal KS-I displays variable degrees of sulfation along the KS chain ranging from non-sulfated polylactosamine, mono-sulfated and disulfated disaccharide regions. Skeletal KS-II is almost completely sulfated consisting of disulfated disaccharides interrupted by occasional mono-sulfated N-acetyllactosamine residues. KS-III also contains highly sulfated KS disaccharides but differs from KS-I and KS-II through 2-O-mannose linkage to serine or threonine core protein residues on proteoglycans such as phosphacan and abakan in brain tissue. Historically, the major emphasis on the biology of KS has focused on its sulfated regions for good reason. The sulfation motifs on KS convey important molecular recognition information and direct cell behavior through a number of interactive proteins. Emerging evidence also suggest functional roles for the poly-N-acetyllactosamine regions of KS requiring further investigation. Thus further research is warranted to better understand the complexities of KS.
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Affiliation(s)
- Bruce Caterson
- Connective Tissue Biology Laboratories, School of Biosciences, College of Biological & Life Sciences, Cardiff University, Cardiff, Wales, UK
| | - James Melrose
- Raymond Purves Bone and Joint Research Laboratory, Kolling Institute of Medical Research, Northern Sydney Local Health District, St. Leonards, NSW, Australia
- Sydney Medical School, Northern, The University of Sydney, Royal North Shore Hospital, St. Leonards, NSW, Australia
- Graduate School of Biomedical Engineering, University of New South Wales, Sydney, NSW, Australia
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48
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Russo E, Citraro R, Mula M. The preclinical discovery and development of brivaracetam for the treatment of focal epilepsy. Expert Opin Drug Discov 2017; 12:1169-1178. [DOI: 10.1080/17460441.2017.1366985] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- Emilio Russo
- Science of Health Department, School of Medicine and Surgery, University of Catanzaro, Catanzaro, Italy
| | - Rita Citraro
- Science of Health Department, School of Medicine and Surgery, University of Catanzaro, Catanzaro, Italy
| | - Marco Mula
- Atkinson Morley Regional Neuroscience Centre, St George’s University Hospitals NHS Foundation Trust, London, UK
- Institute of Medical and Biomedical Education, St George’s University of London, London, UK
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49
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Synaptic vesicle 2C and its synaptic-related function. Clin Chim Acta 2017; 472:112-117. [PMID: 28774501 DOI: 10.1016/j.cca.2017.07.029] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Revised: 07/27/2017] [Accepted: 07/30/2017] [Indexed: 11/22/2022]
Abstract
Synaptic vesicle 2 C (SV2C) is a novel isoform belonging to the synaptic vesicle 2 (SV2) protein superfamily; a family of proteins known to have roles in vesicle trafficking, exocytosis and neurotransmission. In humans, SV2C is expressed in evolutionarily older brain regions, and is a known receptor for botulinum neurotoxin/A (BoNT/A), controlling glucose-evoked granule recruitment and regulating dopamine release, thus serving as a potential target molecule in the treatment of psychosis. In addition, recent researches have shown that SV2C regulates hypertension and accelerates venous thromboembolism (VTE) and coagulation pathways and may play roles in several non-nervous system diseases. In terms of regulation, SV2C is positively regulated by both alendronate and statins. As SV2C may provide a potential novel therapeutic target for psychosis and other diseases, this article reviews the progress made thus far in understanding the structure, distribution, function and regulation of SV2C.
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50
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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.
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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.
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