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Xie L, Zhao J, Li Y, Bai J. PET brain imaging in neurological disorders. Phys Life Rev 2024; 49:100-111. [PMID: 38574584 DOI: 10.1016/j.plrev.2024.03.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2024] [Accepted: 03/20/2024] [Indexed: 04/06/2024]
Abstract
Brain disorders are a series of conditions with damage or loss of neurons, such as Parkinson's disease (PD), Alzheimer's disease (AD), or drug dependence. These individuals have gradual deterioration of cognitive, motor, and other central nervous system functions affected. This degenerative trajectory is intricately associated with dysregulations in neurotransmitter systems. Positron Emission Tomography (PET) imaging, employing radiopharmaceuticals and molecular imaging techniques, emerges as a crucial tool for detecting brain biomarkers. It offers invaluable insights for early diagnosis and distinguishing brain disorders. This article comprehensively reviews the application and progress of conventional and novel PET imaging agents in diagnosing brain disorders. Furthermore, it conducts a thorough analysis on merits and limitations. The article also provides a forward-looking perspective in the future development directions of PET imaging agents for diagnosing brain disorders and proposes potential innovative strategies. It aims to furnish clinicians and researchers with an all-encompassing overview of the latest advancements and forthcoming trends in the utilization of PET imaging for diagnosing brain disorders.
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Affiliation(s)
- Lijun Xie
- Faculty of Life science and Technology, Kunming University of Science and Technology, Kunming 650500, PR China; Laboratory of Molecular Neurobiology, Medical school, Kunming University of Science and Technology, Kunming 650500, PR China; Department of Nuclear Medicine, First Affiliated Hospital of Kunming Medical University, Kunming 650032, PR China
| | - Jihua Zhao
- Department of Nuclear Medicine, First Affiliated Hospital of Kunming Medical University, Kunming 650032, PR China
| | - Ye Li
- Laboratory of Molecular Neurobiology, Medical school, Kunming University of Science and Technology, Kunming 650500, PR China.
| | - Jie Bai
- Laboratory of Molecular Neurobiology, Medical school, Kunming University of Science and Technology, Kunming 650500, PR China.
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Li J, Huang Q, Qi N, He K, Li S, Huang L, Pan F, Ren S, Hua F, Huang Y, Guan Y, Guo Q, Zhao J, Xie F. The associations between synaptic density and "A/T/N" biomarkers in Alzheimer's disease: An 18F-SynVesT-1 PET/MR study. J Cereb Blood Flow Metab 2024; 44:1199-1207. [PMID: 38295871 PMCID: PMC11179616 DOI: 10.1177/0271678x241230733] [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] [Received: 06/29/2023] [Revised: 12/08/2023] [Accepted: 12/26/2023] [Indexed: 06/13/2024]
Abstract
A newly developed SV2A radiotracer, 18F-SynVesT-1, was used in this study to investigate synaptic density and its association with Alzheimer's disease (AD) "A/T/N" biomarkers. The study included a cohort of 97 subjects, consisting of 64 patients with cognitive impairment (CI) and 33 individuals with normal cognition (CU). All subjects underwent 18F-SynVesT-1 PET/MR and 18F-florbetapir PET/CT scans. Additionally, a subgroup of individuals also underwent 18F-MK-6240, 18F-FDG PET/CT, plasma Aβ42/Aβ40 and p-tau181 tests. The differences in synaptic density between the groups and the correlations between synaptic density and AD "A/T/N" biomarkers were analyzed. The results showed that compared to the CU group, the CI with Aβ+ (CI+) group exhibited the most pronounced synapse loss in the hippocampus, with some loss also observed in the neocortex. Furthermore, synaptic density in the hippocampus and parahippocampal gyrus showed associations with AD biomarkers detected by both imaging and plasma tests in the CI group. The associations between synaptic density and FDG uptake and hippocampal volume were also observed in the CI+ group. In conclusion, the study demonstrated significant synaptic density loss, as measured by the promising tracer 18F-SynVesT-1, and its close correlation with "A/T/N" biomarkers in patients with both Alzheimer's clinical syndrome and pathological changes.
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Affiliation(s)
- Junpeng Li
- Department of Nuclear Medicine & PET Center, Huashan Hospital, Fudan University, Shanghai, China
- Department of Nuclear Medicine, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Qi Huang
- Department of Nuclear Medicine & PET Center, Huashan Hospital, Fudan University, Shanghai, China
| | - Na Qi
- Department of Nuclear Medicine, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, China
| | - Kun He
- Department of Nuclear Medicine & PET Center, Huashan Hospital, Fudan University, Shanghai, China
| | - Songye Li
- PET Center, Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Lin Huang
- Department of Gerontology, Shanghai Jiaotong University Affiliated Sixth People’s Hospital, Shanghai, China
| | - Fengfeng Pan
- Department of Gerontology, Shanghai Jiaotong University Affiliated Sixth People’s Hospital, Shanghai, China
| | - Shuhua Ren
- Department of Nuclear Medicine & PET Center, Huashan Hospital, Fudan University, Shanghai, China
| | - Fengchun Hua
- Department of Nuclear Medicine, Longhua Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Yiyun Huang
- PET Center, Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Yihui Guan
- Department of Nuclear Medicine & PET Center, Huashan Hospital, Fudan University, Shanghai, China
| | - Qihao Guo
- Department of Gerontology, Shanghai Jiaotong University Affiliated Sixth People’s Hospital, Shanghai, China
| | - Jun Zhao
- Department of Nuclear Medicine, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, China
| | - Fang Xie
- Department of Nuclear Medicine & PET Center, Huashan Hospital, Fudan University, Shanghai, China
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Zhao M, Chen X, Liu J, Feng Y, Wang C, Xu T, Liu W, Liu X, Liu M, Hou D. Sorl1 knockout inhibits expression of brain-derived neurotrophic factor: involvement in the development of late-onset Alzheimer's disease. Neural Regen Res 2024; 19:1602-1607. [PMID: 38051905 PMCID: PMC10883503 DOI: 10.4103/1673-5374.387975] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Accepted: 09/15/2023] [Indexed: 12/07/2023] Open
Affiliation(s)
- Mingri Zhao
- Center for Medical Genetics & Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan Province, China
| | - Xun Chen
- Department of Neurology, The Third Xiangya Hospital of Central South University, Changsha, Hunan Province, China
| | - Jiangfeng Liu
- Department of Neurology, The Third Xiangya Hospital of Central South University, Changsha, Hunan Province, China
| | - Yanjin Feng
- Department of Neurology, The Third Xiangya Hospital of Central South University, Changsha, Hunan Province, China
| | - Chen Wang
- Department of Neurology, The Third Xiangya Hospital of Central South University, Changsha, Hunan Province, China
| | - Ting Xu
- Department of Neurology, The Third Xiangya Hospital of Central South University, Changsha, Hunan Province, China
| | - Wanxi Liu
- Center for Medical Genetics & Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan Province, China
| | - Xionghao Liu
- Center for Medical Genetics & Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan Province, China
| | - Mujun Liu
- Department of Cell Biology, School of Life Sciences, Central South University, Changsha, Hunan Province, China
| | - Deren Hou
- Department of Neurology, The Third Xiangya Hospital of Central South University, Changsha, Hunan Province, China
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Wang J, Huang Q, He K, Li J, Guo T, Yang Y, Lin Z, Li S, Vanderlinden G, Huang Y, Van Laere K, Guan Y, Guo Q, Ni R, Li B, Xie F. Presynaptic density determined by SV2A PET is closely associated with postsynaptic metabotropic glutamate receptor 5 availability and independent of amyloid pathology in early cognitive impairment. Alzheimers Dement 2024; 20:3876-3888. [PMID: 38634334 PMCID: PMC11180932 DOI: 10.1002/alz.13817] [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: 11/27/2023] [Revised: 02/28/2024] [Accepted: 03/06/2024] [Indexed: 04/19/2024]
Abstract
INTRODUCTION Metabotropic glutamate receptor 5 (mGluR5) is involved in regulating integrative brain function and synaptic transmission. Aberrant mGluR5 signaling and relevant synaptic failure play a key role in the pathophysiological mechanism of Alzheimer's disease (AD). METHODS Ten cognitively impaired (CI) individuals and 10 healthy controls (HCs) underwent [18F]SynVesT-1 and [18F]PSS232 positron emission tomography (PET)/magnetic resonance to assess synaptic density and mGluR5 availability. The associations between mGluR5 availability and synaptic density were examined. A mediation analysis was performed to investigate the possible mediating effects of mGluR5 availability and synaptic loss on the relationship between amyloid deposition and cognition. RESULTS CI patients exhibited lower mGluR5 availability and synaptic density in the medial temporal lobe than HCs. Regional synaptic density was closely associated with regional mGluR5 availability. mGluR5 availability and synaptic loss partially mediated the relationship between amyloid deposition and cognition. CONCLUSIONS Reductions in mGluR5 availability and synaptic density exhibit similar spatial patterns in AD and are closely linked. HIGHLIGHTS Cognitively impaired patients exhibited lower mGluR5 availability and synaptic density in the medial temporal lobe than HCs. Reductions in mGluR5 availability and synaptic density exhibit similar spatial patterns in AD. Regional synaptic density was closely associated with regional mGluR5 availability. mGluR5 availability and synaptic loss partially mediated the relationship between amyloid deposition and global cognition. With further research, modulating mGluR5 availability might be a potential therapeutic strategy for improving synaptic function in AD.
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Affiliation(s)
- Jie Wang
- Department of Nuclear Medicine & PET CenterHuashan Hospital, Fudan UniversityShanghaiChina
| | - Qi Huang
- Department of Nuclear Medicine & PET CenterHuashan Hospital, Fudan UniversityShanghaiChina
| | - Kun He
- Department of Nuclear Medicine & PET CenterHuashan Hospital, Fudan UniversityShanghaiChina
| | - Junpeng Li
- Department of Nuclear Medicine & PET CenterHuashan Hospital, Fudan UniversityShanghaiChina
| | - Tengfei Guo
- Institute of Biomedical Engineering, Shenzhen Bay LaboratoryShenzhenChina
| | - Yang Yang
- Beijing United Imaging Research Institute of Intelligent ImagingBeijingChina
| | - Zengping Lin
- Central Research Institute, United Imaging Healthcare Group Co., LtdShanghaiChina
| | - Songye Li
- Department of Radiology and Biomedical ImagingPET CenterYale University School of MedicineNew HavenConnecticutUSA
| | - Greet Vanderlinden
- Department of Imaging and PathologyNuclear Medicine and Molecular Imaging, KU LeuvenLeuvenBelgium
| | - Yiyun Huang
- Department of Radiology and Biomedical ImagingPET CenterYale University School of MedicineNew HavenConnecticutUSA
| | - Koen Van Laere
- Department of Imaging and PathologyNuclear Medicine and Molecular Imaging, KU LeuvenLeuvenBelgium
| | - Yihui Guan
- Department of Nuclear Medicine & PET CenterHuashan Hospital, Fudan UniversityShanghaiChina
| | - Qihao Guo
- Department of GerontologyShanghai Jiao Tong University Affiliated Sixth People's HospitalShanghaiChina
| | - Ruiqing Ni
- Institute for Biomedical Engineering, University of Zurich & ETH ZurichZurichSwitzerland
- Institute for Regenerative MedicineUniversity of ZurichZurichSwitzerland
| | - Binying Li
- Department of Neurology and Institute of NeurologyRuijin Hospital, Shanghai 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 Science, Fudan UniversityShanghaiChina
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Penny LK, Lofthouse R, Arastoo M, Porter A, Palliyil S, Harrington CR, Wischik CM. Considerations for biomarker strategies in clinical trials investigating tau-targeting therapeutics for Alzheimer's disease. Transl Neurodegener 2024; 13:25. [PMID: 38773569 PMCID: PMC11107038 DOI: 10.1186/s40035-024-00417-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Accepted: 04/24/2024] [Indexed: 05/24/2024] Open
Abstract
The use of biomarker-led clinical trial designs has been transformative for investigating amyloid-targeting therapies for Alzheimer's disease (AD). The designs have ensured the correct selection of patients on these trials, supported target engagement and have been used to support claims of disease modification and clinical efficacy. Ultimately, this has recently led to approval of disease-modifying, amyloid-targeting therapies for AD; something that should be noted for clinical trials investigating tau-targeting therapies for AD. There is a clear overlap of the purpose of biomarker use at each stage of clinical development between amyloid-targeting and tau-targeting clinical trials. However, there are differences within the potential context of use and interpretation for some biomarkers in particular measurements of amyloid and utility of soluble, phosphorylated tau biomarkers. Given the complexities of tau in health and disease, it is paramount that therapies target disease-relevant tau and, in parallel, appropriate assays of target engagement are developed. Tau positron emission tomography, fluid biomarkers reflecting tau pathology and downstream measures of neurodegeneration will be important both for participant recruitment and for monitoring disease-modification in tau-targeting clinical trials. Bespoke design of biomarker strategies and interpretations for different modalities and tau-based targets should also be considered.
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Affiliation(s)
- Lewis K Penny
- Institute of Medical Sciences, University of Aberdeen, Aberdeen, UK
- Scottish Biologics Facility, University of Aberdeen, Aberdeen, UK
- TauRx Therapeutics Ltd, Aberdeen, UK
| | - Richard Lofthouse
- Institute of Medical Sciences, University of Aberdeen, Aberdeen, UK
- Scottish Biologics Facility, University of Aberdeen, Aberdeen, UK
| | - Mohammad Arastoo
- Institute of Medical Sciences, University of Aberdeen, Aberdeen, UK
- Scottish Biologics Facility, University of Aberdeen, Aberdeen, UK
| | - Andy Porter
- Institute of Medical Sciences, University of Aberdeen, Aberdeen, UK
- Scottish Biologics Facility, University of Aberdeen, Aberdeen, UK
| | - Soumya Palliyil
- Institute of Medical Sciences, University of Aberdeen, Aberdeen, UK
- Scottish Biologics Facility, University of Aberdeen, Aberdeen, UK
| | - Charles R Harrington
- Institute of Medical Sciences, University of Aberdeen, Aberdeen, UK
- GT Diagnostics (UK) Ltd, Aberdeen, UK
- TauRx Therapeutics Ltd, Aberdeen, UK
| | - Claude M Wischik
- Institute of Medical Sciences, University of Aberdeen, Aberdeen, UK.
- GT Diagnostics (UK) Ltd, Aberdeen, UK.
- TauRx Therapeutics Ltd, Aberdeen, UK.
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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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Bavarsad MS, Grinberg LT. SV2A PET imaging in human neurodegenerative diseases. Front Aging Neurosci 2024; 16:1380561. [PMID: 38699560 PMCID: PMC11064927 DOI: 10.3389/fnagi.2024.1380561] [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: 02/01/2024] [Accepted: 03/20/2024] [Indexed: 05/05/2024] Open
Abstract
This manuscript presents a thorough review of synaptic vesicle glycoprotein 2A (SV2A) as a biomarker for synaptic integrity using Positron Emission Tomography (PET) in neurodegenerative diseases. Synaptic pathology, characterized by synaptic loss, has been linked to various brain diseases. Therefore, there is a need for a minimally invasive approach to measuring synaptic density in living human patients. Several radiotracers targeting synaptic vesicle protein 2A (SV2A) have been created and effectively adapted for use in human subjects through PET scans. SV2A is an integral glycoprotein found in the membranes of synaptic vesicles in all synaptic terminals and is widely distributed throughout the brain. The review delves into the development of SV2A-specific PET radiotracers, highlighting their advancements and limitations in neurodegenerative diseases. Among these tracers, 11C-UCB-J is the most used so far. We summarize and discuss an increasing body of research that compares measurements of synaptic density using SV2A PET with other established indicators of neurodegenerative diseases, including cognitive performance and radiological findings, thus providing a comprehensive analysis of SV2A's effectiveness and reliability as a diagnostic tool in contrast to traditional markers. Although the literature overall suggests the promise of SV2A as a diagnostic and therapeutic monitoring tool, uncertainties persist regarding the superiority of SV2A as a biomarker compared to other available markers. The review also underscores the paucity of studies characterizing SV2A distribution and loss in human brain tissue from patients with neurodegenerative diseases, emphasizing the need to generate quantitative neuropathological maps of SV2A density in cases with neurodegenerative diseases to fully harness the potential of SV2A PET imaging in clinical settings. We conclude by outlining future research directions, stressing the importance of integrating SV2A PET imaging with other biomarkers and clinical assessments and the need for longitudinal studies to track SV2A changes throughout neurodegenerative disease progression, which could lead to breakthroughs in early diagnosis and the evaluation of new treatments.
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Affiliation(s)
| | - Lea T. Grinberg
- Memory and Aging Center, Weill Institute for Neurosciences, University of California, San Francisco (UCSF), San Francisco, CA, United States
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Wang X, Zhang X, Liu J, Zhang J, Liu C, Cui Y, Song Q, Hou Y, Wang Y, Zhang Q, Zhang Y, Fan Y, Jia J, Wang P. Synaptic vesicle glycoprotein 2 A in serum is an ideal biomarker for early diagnosis of Alzheimer's disease. Alzheimers Res Ther 2024; 16:82. [PMID: 38615037 PMCID: PMC11015666 DOI: 10.1186/s13195-024-01440-9] [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: 01/16/2024] [Accepted: 03/26/2024] [Indexed: 04/15/2024]
Abstract
BACKGROUND Previous studies have demonstrated that early intervention was the best plan to inhibit the progression of Alzheimer's disease (AD), which relied on the discovery of early diagnostic biomarkers. In this study, synaptic vesicle glycoprotein 2 A (SV2A) was examined to improve the early diagnostic efficiency in AD. METHODS In this study, biomarker testing was performed through the single-molecule array (Simoa). A total of 121 subjects including cognitively unimpaired controls, amnestic mild cognitive impairment (aMCI), AD and other types of dementia underwent cerebrospinal fluid (CSF) SV2A testing; 430 subjects including health controls, aMCI, AD and other types of dementia underwent serum SV2A, glial fibrillary acidic protein (GFAP), neurofilament light chain (NfL) and p-tau217 testing; 92 subjects including aMCI and AD underwent both CSF SV2A and serum SV2A testing; 115 cognitively unimpaired subjects including APOE ε4 carriers and APOE ε4 non-carriers were tested for serum SV2A, GFAP, NfL and p-tau217. Then, the efficacy of SV2A for the early diagnosis of AD and its ability to identify those at high risk of AD from a cognitively unimpaired population were further analyzed. RESULTS Both CSF and serum SV2A significantly and positively correlated with cognitive performance in patients with AD, and their levels gradually decreased with the progression of AD. Serum SV2A demonstrated excellent diagnostic efficacy for aMCI, with a sensitivity of 97.8%, which was significantly higher than those of NfL, GFAP, and p-tau217. The SV2A-positive rates ranged from 92.86 to 100% in aMCI cases that were negative for the above three biomarkers. Importantly, of all the biomarkers tested, serum SV2A had the highest positivity rate (81.82%) in individuals at risk for AD. CONCLUSIONS Serum SV2A was demonstrated to be a novel and ideal biomarker for the early diagnosis of AD, which can effectively distinguish those at high risk of AD in cognitively unimpaired populations.
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Affiliation(s)
- Xiaoling Wang
- Department of Clinical Laboratory, Xuanwu Hospital, National Clinical Research Center for Geriatric Diseases, Capital Medical University, 45 Changchun Street, Beijing, 100053, China
| | - Xiaomin Zhang
- Department of Clinical Laboratory, Xuanwu Hospital, National Clinical Research Center for Geriatric Diseases, Capital Medical University, 45 Changchun Street, Beijing, 100053, China
| | - Jing Liu
- Department of Clinical Laboratory, Xuanwu Hospital, National Clinical Research Center for Geriatric Diseases, Capital Medical University, 45 Changchun Street, Beijing, 100053, China
| | - Jingjing Zhang
- Department of Clinical Laboratory, Xuanwu Hospital, National Clinical Research Center for Geriatric Diseases, Capital Medical University, 45 Changchun Street, Beijing, 100053, China
| | - Congcong Liu
- Department of Clinical Laboratory, Xuanwu Hospital, National Clinical Research Center for Geriatric Diseases, Capital Medical University, 45 Changchun Street, Beijing, 100053, China
| | - Yuting Cui
- Department of Clinical Laboratory, Xuanwu Hospital, National Clinical Research Center for Geriatric Diseases, Capital Medical University, 45 Changchun Street, Beijing, 100053, China
| | - Qiao Song
- Department of Clinical Laboratory, Xuanwu Hospital, National Clinical Research Center for Geriatric Diseases, Capital Medical University, 45 Changchun Street, Beijing, 100053, China
| | - Yuli Hou
- Department of Clinical Laboratory, Xuanwu Hospital, National Clinical Research Center for Geriatric Diseases, Capital Medical University, 45 Changchun Street, Beijing, 100053, China
| | - Yaqi Wang
- Department of Clinical Laboratory, Xuanwu Hospital, National Clinical Research Center for Geriatric Diseases, Capital Medical University, 45 Changchun Street, Beijing, 100053, China
| | - Qian Zhang
- Department of Clinical Laboratory, Xuanwu Hospital, National Clinical Research Center for Geriatric Diseases, Capital Medical University, 45 Changchun Street, Beijing, 100053, China
| | - Yingzhen Zhang
- Department of Clinical Laboratory, Xuanwu Hospital, National Clinical Research Center for Geriatric Diseases, Capital Medical University, 45 Changchun Street, Beijing, 100053, China
| | - Yujian Fan
- Department of Clinical Laboratory, Xuanwu Hospital, National Clinical Research Center for Geriatric Diseases, Capital Medical University, 45 Changchun Street, Beijing, 100053, China
| | - Jianping Jia
- National Clinical Research Center for Geriatric Disorders, 45 Changchun Street, Beijing, 100053, China.
- Innovation Center for Neurological Disorders, Department of Neurology, Xuanwu Hospital, Capital Medical University, 45 Changchun Street, Beijing, 100053, China.
- Beijing Key Laboratory of Geriatric Cognitive Disorders, 45 Changchun Street, Beijing, 100053, China.
- Clinical Center for Neurodegenerative Disease and Memory Impairment, Capital Medical University, 45 Changchun Street, Beijing, 100053, China.
- Center of Alzheimer's Disease, Beijing Institute for Brain Disorders, 45 Changchun Street, Beijing, 100053, China.
- Key Laboratory of Neurodegenerative Diseases, Ministry of Education, 45 Changchun Street, Beijing, 100053, China.
| | - Peichang Wang
- Department of Clinical Laboratory, Xuanwu Hospital, National Clinical Research Center for Geriatric Diseases, Capital Medical University, 45 Changchun Street, Beijing, 100053, China.
- National Clinical Research Center for Geriatric Disorders, 45 Changchun Street, Beijing, 100053, China.
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Wang J, Huang Q, Chen X, You Z, He K, Guo Q, Huang Y, Yang Y, Lin Z, Guo T, Zhao J, Guan Y, Li B, Xie F. Tau pathology is associated with synaptic density and longitudinal synaptic loss in Alzheimer's disease. Mol Psychiatry 2024:10.1038/s41380-024-02501-z. [PMID: 38589563 DOI: 10.1038/s41380-024-02501-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Revised: 02/23/2024] [Accepted: 02/27/2024] [Indexed: 04/10/2024]
Abstract
The associations of synaptic loss with amyloid-β (Aβ) and tau pathology measured by positron emission tomography (PET) and plasma analysis in Alzheimer's disease (AD) patients are unknown. Seventy-five participants, including 26 AD patients, 19 mild cognitive impairment (MCI) patients, and 30 normal controls (NCs), underwent [18F]SynVesT-1 PET/MR scans to assess synaptic density and [18F]florbetapir and [18F]MK6240 PET/CT scans to evaluate Aβ plaques and tau tangles. Among them, 19 AD patients, 12 MCI patients, and 29 NCs had plasma Aβ42/40 and p-tau181 levels measured by the Simoa platform. Twenty-three individuals, 6 AD patients, 4 MCI patients, and 13 NCs, underwent [18F]SynVesT-1 PET/MRI and [18F]MK6240 PET/CT scans during a one-year follow-up assessment. The associations of Aβ and tau pathology with cross-sectional and longitudinal synaptic loss were investigated using Pearson correlation analyses, generalized linear models and mediation analyses. AD patients exhibited lower synaptic density than NCs and MCI patients. In the whole cohort, global Aβ deposition was associated with synaptic loss in the medial (r = -0.431, p < 0.001) and lateral (r = -0.406, p < 0.001) temporal lobes. Synaptic density in almost all regions was related to the corresponding regional tau tangles independent of global Aβ deposition in the whole cohort and stratified groups. Synaptic density in the medial and lateral temporal lobes was correlated with plasma Aβ42/40 (r = 0.300, p = 0.020/r = 0.289, p = 0.025) and plasma p-tau 181 (r = -0.412, p = 0.001/r = -0.529, p < 0.001) levels in the whole cohort. Mediation analyses revealed that tau tangles mediated the relationship between Aβ plaques and synaptic density in the whole cohort. Baseline tau pathology was positively associated with longitudinal synaptic loss. This study suggested that tau burden is strongly linked to synaptic density independent of Aβ plaques, and also can predict longitudinal synaptic loss.
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Affiliation(s)
- Jie Wang
- Department of Nuclear Medicine & PET Center, Huashan Hospital, Fudan University, Shanghai, 200040, China
| | - Qi Huang
- Department of Nuclear Medicine & PET Center, Huashan Hospital, Fudan University, Shanghai, 200040, China
| | - Xing Chen
- Department of Nuclear Medicine, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, 310000, China
| | - Zhiwen You
- Department of Nuclear Medicine, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, 310000, China
| | - Kun He
- Department of Nuclear Medicine & PET Center, Huashan Hospital, Fudan University, Shanghai, 200040, China
| | - Qihao Guo
- Department of Gerontology, Shanghai Jiaotong University Affiliated Sixth People's Hospital, Shanghai, 200233, China
| | - Yiyun Huang
- PET Center, Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, Connecticut, CT, 06520-8048, USA
| | - Yang Yang
- Beijing United Imaging Research Institute of Intelligent Imaging, Beijing, 100089, China
| | - Zengping Lin
- Central Research Institute, United Imaging Healthcare Group Co., Ltd, Shanghai, 201807, China
| | - Tengfei Guo
- Institute of Biomedical Engineering, Shenzhen Bay Laboratory, Shenzhen, 518000, China
| | - Jun Zhao
- Department of Nuclear Medicine, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, 310000, China
| | - Yihui Guan
- Department of Nuclear Medicine & PET Center, Huashan Hospital, Fudan University, Shanghai, 200040, China.
| | - Binyin Li
- Department of Neurology and Institute of Neurology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China.
| | - Fang Xie
- Department of Nuclear Medicine & PET Center, Huashan Hospital, Fudan University, Shanghai, 200040, China.
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10
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DiFilippo A, Jonaitis E, Makuch R, Gambetti B, Fleming V, Ennis G, Barnhart T, Engle J, Bendlin B, Johnson S, Handen B, Krinsky-McHale S, Hartley S, Christian B. Measurement of synaptic density in Down syndrome using PET imaging: a pilot study. Sci Rep 2024; 14:4676. [PMID: 38409349 PMCID: PMC10897336 DOI: 10.1038/s41598-024-54669-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Accepted: 02/15/2024] [Indexed: 02/28/2024] Open
Abstract
Down syndrome (DS) is the most prevalent genetic cause of intellectual disability, resulting from trisomy 21. Recently, positron emission tomography (PET) imaging has been used to image synapses in vivo. The motivation for this pilot study was to investigate whether synaptic density in low functioning adults with DS can be evaluated using the PET radiotracer [11C]UCB-J. Data were acquired from low functioning adults with DS (n = 4) and older neurotypical (NT) adults (n = 37). Motion during the scans required the use of a 10-minute acquisition window for the calculation of synaptic density using SUVR50-60,CS which was determined to be a suitable approximation for specific binding in this analysis using dynamic data from the NT group. Of the regions analyzed a large effect was observed when comparing DS and NT hippocampus and cerebral cortex synaptic density as well as hippocampus and cerebellum volumes. In this pilot study, PET imaging of [11C]UCB-J was successfully completed and synaptic density measured in low functioning DS adults. This work provides the basis for studies where synaptic density may be compared between larger groups of NT adults and adults with DS who have varying degrees of baseline cognitive status.
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Affiliation(s)
- Alexandra DiFilippo
- Madison School of Medicine and Public Health, University of Wisconsin, Madison, WI, USA.
| | - Erin Jonaitis
- Madison School of Medicine and Public Health, University of Wisconsin, Madison, WI, USA
| | - Renee Makuch
- University of Wisconsin-Madison Waisman Center, Madison, WI, USA
| | - Brianna Gambetti
- University of Wisconsin-Madison Waisman Center, Madison, WI, USA
| | - Victoria Fleming
- University of Wisconsin-Madison Waisman Center, Madison, WI, USA
| | - Gilda Ennis
- Madison School of Medicine and Public Health, University of Wisconsin, Madison, WI, USA
| | - Todd Barnhart
- Madison School of Medicine and Public Health, University of Wisconsin, Madison, WI, USA
| | - Jonathan Engle
- Madison School of Medicine and Public Health, University of Wisconsin, Madison, WI, USA
| | - Barbara Bendlin
- Madison School of Medicine and Public Health, University of Wisconsin, Madison, WI, USA
| | - Sterling Johnson
- Madison School of Medicine and Public Health, University of Wisconsin, Madison, WI, USA
| | - Benjamin Handen
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, USA
| | - Sharon Krinsky-McHale
- New York State Institute for Basic Research in Developmental Disabilities, Staten Island, NY, USA
| | - Sigan Hartley
- University of Wisconsin-Madison Waisman Center, Madison, WI, USA
| | - Bradley Christian
- Madison School of Medicine and Public Health, University of Wisconsin, Madison, WI, USA
- University of Wisconsin-Madison Waisman Center, Madison, WI, USA
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11
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Drake LR, Wu Y, Naganawa M, Asch R, Zheng C, Najafzadeh S, Pracitto R, Lindemann M, Li S, Ropchan J, Labaree D, Emery PR, Dias M, Henry S, Nabulsi N, Matuskey D, Hillmer AT, Gallezot JD, Carson RE, Cai Z, Huang Y. First-in-Human Study of 18F-SynVesT-2: An SV2A PET Imaging Probe with Fast Brain Kinetics and High Specific Binding. J Nucl Med 2024; 65:jnumed.123.266470. [PMID: 38360052 PMCID: PMC10924160 DOI: 10.2967/jnumed.123.266470] [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: 07/31/2023] [Revised: 12/19/2023] [Accepted: 12/19/2023] [Indexed: 02/17/2024] Open
Abstract
PET imaging of synaptic vesicle glycoprotein 2A allows for noninvasive quantification of synapses. This first-in-human study aimed to evaluate the kinetics, test-retest reproducibility, and extent of specific binding of a recently developed synaptic vesicle glycoprotein 2A PET ligand, (R)-4-(3-(18F-fluoro)phenyl)-1-((3-methylpyridin-4-yl)methyl)pyrrolidine-2-one (18F-SynVesT-2), with fast brain kinetics. Methods: Nine healthy volunteers participated in this study and were scanned on a High Resolution Research Tomograph scanner with 18F-SynVesT-2. Five volunteers were scanned twice on 2 different days. Five volunteers were rescanned with preinjected levetiracetam (20 mg/kg, intravenously). Arterial blood was collected to calculate the plasma free fraction and generate the arterial input function. Individual MR images were coregistered to a brain atlas to define regions of interest for generating time-activity curves, which were fitted with 1- and 2-tissue-compartment (1TC and 2TC) models to derive the regional distribution volume (V T). The regional nondisplaceable binding potential (BP ND) was calculated from 1TC V T, using the centrum semiovale (CS) as the reference region. Results: 18F-SynVesT-2 was synthesized with high molar activity (187 ± 69 MBq/nmol, n = 19). The parent fraction of 18F-SynVesT-2 in plasma was 28% ± 8% at 30 min after injection, and the plasma free fraction was high (0.29 ± 0.04). 18F-SynVesT-2 entered the brain quickly, with an SUVpeak of 8 within 10 min after injection. Regional time-activity curves fitted well with both the 1TC and the 2TC models; however, V T was estimated more reliably using the 1TC model. The 1TC V T ranged from 1.9 ± 0.2 mL/cm3 in CS to 7.6 ± 0.8 mL/cm3 in the putamen, with low absolute test-retest variability (6.0% ± 3.6%). Regional BP ND ranged from 1.76 ± 0.21 in the hippocampus to 3.06 ± 0.29 in the putamen. A 20-min scan was sufficient to provide reliable V T and BP ND Conclusion: 18F-SynVesT-2 has fast kinetics, high specific uptake, and low nonspecific uptake in the brain. Consistent with the nonhuman primate results, the kinetics of 18F-SynVesT-2 is faster than the kinetics of 11C-UCB-J and 18F-SynVesT-1 in the human brain and enables a shorter dynamic scan to derive physiologic information on cerebral blood flow and synapse density.
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Affiliation(s)
| | - Yanjun Wu
- Yale PET Center, New Haven, Connecticut
| | | | - Ruth Asch
- Yale PET Center, New Haven, Connecticut
| | | | | | | | | | - Songye Li
- Yale PET Center, New Haven, Connecticut
| | | | | | | | - Mark Dias
- Yale PET Center, New Haven, Connecticut
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12
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Wen L, Bi D, Shen Y. Complement-mediated synapse loss in Alzheimer's disease: mechanisms and involvement of risk factors. Trends Neurosci 2024; 47:135-149. [PMID: 38129195 DOI: 10.1016/j.tins.2023.11.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 10/25/2023] [Accepted: 11/27/2023] [Indexed: 12/23/2023]
Abstract
The complement system is increasingly recognized as a key player in the synapse loss and cognitive impairments observed in Alzheimer's disease (AD). In particular, the process of complement-dependent synaptic pruning through phagocytosis is over-activated in AD brains, driving detrimental excessive synapse elimination and contributing to synapse loss, which is the strongest neurobiological correlate of cognitive impairments in AD. Herein we review recent advances in characterizing complement-mediated synapse loss in AD, summarize the underlying mechanisms, and discuss the possible involvement of AD risk factors such as aging and various risk genes. We conclude with an overview of key questions that remain to be addressed.
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Affiliation(s)
- Lang Wen
- Department of Neurology and Institute on Aging and Brain Disorders, The First Affiliated Hospital of USTC, Neurodegenerative Disease Research Center, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, 230026, China
| | - Danlei Bi
- Department of Neurology and Institute on Aging and Brain Disorders, The First Affiliated Hospital of USTC, Neurodegenerative Disease Research Center, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, 230026, China; Anhui Province Key Laboratory of Biomedical Aging Research, University of Science and Technology of China, Hefei, 230026, China; Institute of Artificial Intelligence, Hefei Comprehensive National Science Center, Hefei, 230026, China; CAS Key Laboratory of Brain Function and Disease, School of Life Sciences, University of Science and Technology of China, Hefei, 230026, China; Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, 200031, China.
| | - Yong Shen
- Department of Neurology and Institute on Aging and Brain Disorders, The First Affiliated Hospital of USTC, Neurodegenerative Disease Research Center, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, 230026, China; Anhui Province Key Laboratory of Biomedical Aging Research, University of Science and Technology of China, Hefei, 230026, China; CAS Key Laboratory of Brain Function and Disease, School of Life Sciences, University of Science and Technology of China, Hefei, 230026, China; Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, 200031, China.
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13
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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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14
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Wang J, He Y, Chen X, Huang L, Li J, You Z, Huang Q, Ren S, He K, Schibli R, Mu L, Guan Y, Guo Q, Zhao J, Xie F. Metabotropic glutamate receptor 5 (mGluR5) is associated with neurodegeneration and amyloid deposition in Alzheimer's disease: A [ 18F]PSS232 PET/MRI study. Alzheimers Res Ther 2024; 16:9. [PMID: 38217040 PMCID: PMC10785459 DOI: 10.1186/s13195-024-01385-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Accepted: 01/04/2024] [Indexed: 01/14/2024]
Abstract
BACKGROUND Metabotropic glutamate receptor 5 (mGluR5) is involved in regulating integrative brain function and synaptic transmission. Aberrant mGluR5 signaling and relevant synaptic failure play a key role in the initial pathophysiological mechanism of Alzheimer's disease (AD). The study aims to investigate the association between mGluR5 availability and AD's biomarkers and cognitive function. METHODS We examined 35 individuals with mGluR5 tracer [18F]PSS232 to assess mGluR5 availability, and with [18F]Florbetapir PET to assess global amyloid deposition, and [18F]FDG PET to assess glucose metabolism. The plasma neurofilament light (NfL) and p-tau181 levels in a subset of individuals were measured (n = 27). The difference in mGluR5 availability between the AD and normal control (NC) groups was explored. The associations of mGluR5 availability with amyloid deposition, glucose metabolism, gray matter volume (GMV), neuropsychological assessment scores, and plasma biomarkers were analyzed. RESULTS The mGluR5 availability was significantly reduced in AD patients' hippocampus and parahippocampal gyrus compared to NCs. Global amyloid deposition was positively associated with mGluR5 availability in the AD group and reversely associated in the NC group. The mGluR5 availability was positively correlated with regional glucose metabolism in the overall and stratified analyses. The availability of mGluR5 in the hippocampus and parahippocampal gyrus demonstrated a strong relationship with the GMV of the medial temporal lobe, plasma p-tau181 or NfL levels, and global cognitive performance. CONCLUSIONS [18F]PSS232 PET can quantify the changes of mGluR5 availability in the progression of AD. mGluR5 availability correlated not only with neuropathological biomarkers of AD but also with neurodegenerative biomarkers and cognitive performance. mGluR5 may be a novel neurodegenerative biomarker, and whether mGluR5 could be a potential therapeutic target for AD needs to be further studied.
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Affiliation(s)
- Jie Wang
- Department of Nuclear Medicine &PET Center, Huashan Hospital, Fudan University, Shanghai, China
| | - Yingfang He
- Department of Chemistry and Applied Biosciences, Center for Radiopharmaceutical Sciences, Institute of Pharmaceutical Sciences, ETH Zurich, CH-8093, Zurich, Switzerland
| | - Xing Chen
- Department of Nuclear Medicine, Shanghai East Hospital, School of Medicine, Tongji University, Shanghai, China
| | - Lin Huang
- Department of Gerontology, Shanghai Jiaotong University Affiliated Sixth People's Hospital, Shanghai, China
| | - Junpeng Li
- Department of Nuclear Medicine &PET Center, Huashan Hospital, Fudan University, Shanghai, China
| | - Zhiwen You
- Department of Nuclear Medicine, Shanghai East Hospital, School of Medicine, Tongji University, Shanghai, China
| | - Qi Huang
- Department of Nuclear Medicine &PET Center, Huashan Hospital, Fudan University, Shanghai, China
| | - Shuhua Ren
- Department of Nuclear Medicine &PET Center, Huashan Hospital, Fudan University, Shanghai, China
| | - Kun He
- Department of Nuclear Medicine &PET Center, Huashan Hospital, Fudan University, Shanghai, China
| | - Roger Schibli
- Department of Chemistry and Applied Biosciences, Center for Radiopharmaceutical Sciences, Institute of Pharmaceutical Sciences, ETH Zurich, CH-8093, Zurich, Switzerland
| | - Linjing Mu
- Department of Chemistry and Applied Biosciences, Center for Radiopharmaceutical Sciences, Institute of Pharmaceutical Sciences, ETH Zurich, CH-8093, Zurich, Switzerland
| | - Yihui Guan
- Department of Nuclear Medicine &PET Center, Huashan Hospital, Fudan University, Shanghai, China.
| | - Qihao Guo
- Department of Gerontology, Shanghai Jiaotong University Affiliated Sixth People's Hospital, Shanghai, China.
| | - Jun Zhao
- Department of Nuclear Medicine, Shanghai East Hospital, School of Medicine, Tongji University, Shanghai, China.
| | - Fang Xie
- Department of Nuclear Medicine &PET Center, Huashan Hospital, Fudan University, Shanghai, China.
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15
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Frigerio I, Bouwman MMA, Noordermeer RTGMM, Podobnik E, Popovic M, Timmermans E, Rozemuller AJM, van de Berg WDJ, Jonkman LE. Regional differences in synaptic degeneration are linked to alpha-synuclein burden and axonal damage in Parkinson's disease and dementia with Lewy bodies. Acta Neuropathol Commun 2024; 12:4. [PMID: 38173031 PMCID: PMC10765668 DOI: 10.1186/s40478-023-01711-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Accepted: 12/11/2023] [Indexed: 01/05/2024] Open
Abstract
Regional differences in synaptic degeneration may underlie differences in clinical presentation and neuropathological disease progression in Parkinson's Disease (PD) and Dementia with Lewy bodies (DLB). Here, we mapped and quantified synaptic degeneration in cortical brain regions in PD, PD with dementia (PDD) and DLB, and assessed whether regional differences in synaptic loss are linked to axonal degeneration and neuropathological burden. We included a total of 47 brain donors, 9 PD, 12 PDD, 6 DLB and 20 non-neurological controls. Synaptophysin+ and SV2A+ puncta were quantified in eight cortical regions using a high throughput microscopy approach. Neurofilament light chain (NfL) immunoreactivity, Lewy body (LB) density, phosphorylated-tau and amyloid-β load were also quantified. Group differences in synaptic density, and associations with neuropathological markers and Clinical Dementia Rating (CDR) scores, were investigated using linear mixed models. We found significantly decreased synaptophysin and SV2A densities in the cortex of PD, PDD and DLB cases compared to controls. Specifically, synaptic density was decreased in cortical regions affected at Braak α-synuclein stage 5 in PD (middle temporal gyrus, anterior cingulate and insula), and was additionally decreased in cortical regions affected at Braak α-synuclein stage 4 in PDD and DLB compared to controls (entorhinal cortex, parahippocampal gyrus and fusiform gyrus). Synaptic loss associated with higher NfL immunoreactivity and LB density. Global synaptophysin loss associated with longer disease duration and higher CDR scores. Synaptic neurodegeneration occurred in temporal, cingulate and insular cortices in PD, as well as in parahippocampal regions in PDD and DLB. In addition, synaptic loss was linked to axonal damage and severe α-synuclein burden. These results, together with the association between synaptic loss and disease progression and cognitive impairment, indicate that regional synaptic loss may underlie clinical differences between PD and PDD/DLB. Our results might provide useful information for the interpretation of synaptic biomarkers in vivo.
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Affiliation(s)
- Irene Frigerio
- Department of Anatomy and Neurosciences, Section Clinical Neuroanatomy and Biobanking, Amsterdam UMC location Vrije Universiteit Amsterdam, De Boelelaan 1118, Amsterdam, 1081 HV, The Netherlands.
- Amsterdam Neuroscience, Neurodegeneration, Amsterdam, The Netherlands.
- Amsterdam Neuroscience, Brain imaging, Amsterdam, The Netherlands.
| | - Maud M A Bouwman
- Department of Anatomy and Neurosciences, Section Clinical Neuroanatomy and Biobanking, Amsterdam UMC location Vrije Universiteit Amsterdam, De Boelelaan 1118, Amsterdam, 1081 HV, The Netherlands
- Amsterdam Neuroscience, Neurodegeneration, Amsterdam, The Netherlands
- Amsterdam Neuroscience, Brain imaging, Amsterdam, The Netherlands
| | - Ruby T G M M Noordermeer
- Department of Anatomy and Neurosciences, Section Clinical Neuroanatomy and Biobanking, Amsterdam UMC location Vrije Universiteit Amsterdam, De Boelelaan 1118, Amsterdam, 1081 HV, The Netherlands
| | - Ema Podobnik
- Department of Anatomy and Neurosciences, Section Clinical Neuroanatomy and Biobanking, Amsterdam UMC location Vrije Universiteit Amsterdam, De Boelelaan 1118, Amsterdam, 1081 HV, The Netherlands
| | - Marko Popovic
- Department Molecular cell biology & Immunology, Amsterdam UMC location Vrije Universiteit Amsterdam, De Boelelaan 1117, Amsterdam, Netherlands
| | - Evelien Timmermans
- Department of Anatomy and Neurosciences, Section Clinical Neuroanatomy and Biobanking, Amsterdam UMC location Vrije Universiteit Amsterdam, De Boelelaan 1118, Amsterdam, 1081 HV, The Netherlands
| | - Annemieke J M Rozemuller
- Department of Pathology, Amsterdam UMC location Vrije Universiteit Amsterdam, De Boelelaan 1117, Amsterdam, Netherlands
| | - Wilma D J van de Berg
- Department of Anatomy and Neurosciences, Section Clinical Neuroanatomy and Biobanking, Amsterdam UMC location Vrije Universiteit Amsterdam, De Boelelaan 1118, Amsterdam, 1081 HV, The Netherlands
- Amsterdam Neuroscience, Neurodegeneration, Amsterdam, The Netherlands
| | - Laura E Jonkman
- Department of Anatomy and Neurosciences, Section Clinical Neuroanatomy and Biobanking, Amsterdam UMC location Vrije Universiteit Amsterdam, De Boelelaan 1118, Amsterdam, 1081 HV, The Netherlands
- Amsterdam Neuroscience, Neurodegeneration, Amsterdam, The Netherlands
- Amsterdam Neuroscience, Brain imaging, Amsterdam, The Netherlands
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16
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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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Li A, Yang B, Naganawa M, Fontaine K, Toyonaga T, Carson RE, Tang J. Dose reduction in dynamic synaptic vesicle glycoprotein 2A PET imaging using artificial neural networks. Phys Med Biol 2023; 68:245006. [PMID: 37857316 PMCID: PMC10739622 DOI: 10.1088/1361-6560/ad0535] [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: 07/20/2022] [Revised: 10/02/2023] [Accepted: 10/19/2023] [Indexed: 10/21/2023]
Abstract
Objective. Reducing dose in positron emission tomography (PET) imaging increases noise in reconstructed dynamic frames, which inevitably results in higher noise and possible bias in subsequently estimated images of kinetic parameters than those estimated in the standard dose case. We report the development of a spatiotemporal denoising technique for reduced-count dynamic frames through integrating a cascade artificial neural network (ANN) with the highly constrained back-projection (HYPR) scheme to improve low-dose parametric imaging.Approach. We implemented and assessed the proposed method using imaging data acquired with11C-UCB-J, a PET radioligand bound to synaptic vesicle glycoprotein 2A (SV2A) in the human brain. The patch-based ANN was trained with a reduced-count frame and its full-count correspondence of a subject and was used in cascade to process dynamic frames of other subjects to further take advantage of its denoising capability. The HYPR strategy was then applied to the spatial ANN processed image frames to make use of the temporal information from the entire dynamic scan.Main results. In all the testing subjects including healthy volunteers and Parkinson's disease patients, the proposed method reduced more noise while introducing minimal bias in dynamic frames and the resulting parametric images, as compared with conventional denoising methods.Significance. Achieving 80% noise reduction with a bias of -2% in dynamic frames, which translates into 75% and 70% of noise reduction in the tracer uptake (bias, -2%) and distribution volume (bias, -5%) images, the proposed ANN+HYPR technique demonstrates the denoising capability equivalent to a 11-fold dose increase for dynamic SV2A PET imaging with11C-UCB-J.
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Affiliation(s)
- Andi Li
- Department of Biomedical Engineering, University of Cincinnati, Cincinnati, OH, United States of America
| | - Bao Yang
- School of Biomedical Engineering, Southern Medical University, Guangzhou, Guangdong, People’s Republic of China
| | - Mika Naganawa
- Positron Emission Tomography Center, Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT, United States of America
| | - Kathryn Fontaine
- Positron Emission Tomography Center, Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT, United States of America
| | - Takuya Toyonaga
- Positron Emission Tomography Center, Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT, United States of America
| | - Richard E Carson
- Positron Emission Tomography Center, Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT, United States of America
| | - Jing Tang
- Department of Biomedical Engineering, University of Cincinnati, Cincinnati, OH, United States of America
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Wang YTT, Rosa-Neto P, Gauthier S. Advanced brain imaging for the diagnosis of Alzheimer disease. Curr Opin Neurol 2023; 36:481-490. [PMID: 37639461 DOI: 10.1097/wco.0000000000001198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/31/2023]
Abstract
PURPOSE OF REVIEW The purpose is to review the latest advances of brain imaging for the diagnosis of Alzheimer disease (AD). RECENT FINDINGS Brain imaging techniques provide valuable and complementary information to support the diagnosis of Alzheimer disease in clinical and research settings. The recent FDA accelerated approvals of aducanumab, lecanemab and donanemab made amyloid-PET critical in helping determine the optimal window for anti-amyloid therapeutic interventions. Tau-PET, on the other hand, is considered of key importance for the tracking of disease progression and for monitoring therapeutic interventions in clinical trials. PET imaging for microglial activation, astrocyte reactivity and synaptic degeneration are still new techniques only used in the research field, and more studies are needed to validate their use in the clinical diagnosis of AD. Finally, artificial intelligence has opened new prospective in the early detection of AD using MRI modalities. SUMMARY Brain imaging techniques using PET improve our understanding of the different AD-related pathologies and their relationship with each other along the course of disease. With more robust validation, machine learning and deep learning algorithms could be integrated with neuroimaging modalities to serve as valuable tools for clinicians to make early diagnosis and prognosis of AD.
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Zhao Q, Du X, Chen W, Zhang T, Xu Z. Advances in diagnosing mild cognitive impairment and Alzheimer's disease using 11C-PIB- PET/CT and common neuropsychological tests. Front Neurosci 2023; 17:1216215. [PMID: 37492405 PMCID: PMC10363609 DOI: 10.3389/fnins.2023.1216215] [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: 05/03/2023] [Accepted: 06/15/2023] [Indexed: 07/27/2023] Open
Abstract
Alzheimer's disease (AD) is a critical health issue worldwide that has a negative impact on patients' quality of life, as well as on caregivers, society, and the environment. Positron emission tomography (PET)/computed tomography (CT) and neuropsychological scales can be used to identify AD and mild cognitive impairment (MCI) early, provide a differential diagnosis, and offer early therapies to impede the course of the illness. However, there are few reports of large-scale 11C-PIB-PET/CT investigations that focus on the pathology of AD and MCI. Therefore, further research is needed to determine how neuropsychological test scales and PET/CT measurements of disease progression interact.
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Affiliation(s)
- Qing Zhao
- Department of Neurology, China-Japan Union Hospital of Jilin University, Changchun, Jilin, China
| | - Xinxin Du
- Department of Neurology, China-Japan Union Hospital of Jilin University, Changchun, Jilin, China
| | - Wenhong Chen
- Department of Sleep Medicine, Guangxi Zhuang Autonomous Region People's Hospital, Nanning, Guangxi, China
| | - Ting Zhang
- Department of Rehabilitation, China-Japan Union Hospital of Jilin University, Changchun, Jilin, China
- Rehabilitation Therapeutics, School of Nursing of Jilin University, Changchun, Jilin, China
| | - Zhuo Xu
- Department of Rehabilitation, China-Japan Union Hospital of Jilin University, Changchun, Jilin, China
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20
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O'Dell RS, Higgins-Chen A, Gupta D, Chen MK, Naganawa M, Toyonaga T, Lu Y, Ni G, Chupak A, Zhao W, Salardini E, Nabulsi NB, Huang Y, Arnsten AFT, Carson RE, van Dyck CH, Mecca AP. Principal component analysis of synaptic density measured with [ 11C]UCB-J PET in early Alzheimer's disease. Neuroimage Clin 2023; 39:103457. [PMID: 37422964 PMCID: PMC10338149 DOI: 10.1016/j.nicl.2023.103457] [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: 09/20/2022] [Revised: 05/01/2023] [Accepted: 06/19/2023] [Indexed: 07/11/2023]
Abstract
BACKGROUND Synaptic loss is considered an early pathological event and major structural correlate of cognitive impairment in Alzheimer's disease (AD). We used principal component analysis (PCA) to identify regional patterns of covariance in synaptic density using [11C]UCB-J PET and assessed the association between principal components (PC) subject scores with cognitive performance. METHODS [11C]UCB-J binding was measured in 45 amyloid + participants with AD and 19 amyloid- cognitively normal participants aged 55-85. A validated neuropsychological battery assessed performance across five cognitive domains. PCA was applied to the pooled sample using distribution volume ratios (DVR) standardized (z-scored) by region from 42 bilateral regions of interest (ROI). RESULTS Parallel analysis determined three significant PCs explaining 70.2% of the total variance. PC1 was characterized by positive loadings with similar contributions across the majority of ROIs. PC2 was characterized by positive and negative loadings with strongest contributions from subcortical and parietooccipital cortical regions, respectively, while PC3 was characterized by positive and negative loadings with strongest contributions from rostral and caudal cortical regions, respectively. Within the AD group, PC1 subject scores were positively correlated with performance across all cognitive domains (Pearson r = 0.24-0.40, P = 0.06-0.006), PC2 subject scores were inversely correlated with age (Pearson r = -0.45, P = 0.002) and PC3 subject scores were significantly correlated with CDR-sb (Pearson r = 0.46, P = 0.04). No significant correlations were observed between cognitive performance and PC subject scores in CN participants. CONCLUSIONS This data-driven approach defined specific spatial patterns of synaptic density correlated with unique participant characteristics within the AD group. Our findings reinforce synaptic density as a robust biomarker of disease presence and severity in the early stages of AD.
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Affiliation(s)
- Ryan S O'Dell
- Alzheimer's Disease Research Unit, Yale University School of Medicine, One Church Street, 8(th) Floor, New Haven, CT 06510, USA; Department of Psychiatry, Yale University School of Medicine, 300 George Street, New Haven, CT 06510, USA.
| | - Albert Higgins-Chen
- Alzheimer's Disease Research Unit, Yale University School of Medicine, One Church Street, 8(th) Floor, New Haven, CT 06510, USA; Department of Psychiatry, Yale University School of Medicine, 300 George Street, New Haven, CT 06510, USA; Pain Research, Informatics, Multi-morbidities, and Education Center, VA Connecticut Healthcare System, West Haven, CT, USA
| | - Dhruva Gupta
- Alzheimer's Disease Research Unit, Yale University School of Medicine, One Church Street, 8(th) Floor, 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
| | - Gessica Ni
- Alzheimer's Disease Research Unit, Yale University School of Medicine, One Church Street, 8(th) Floor, New Haven, CT 06510, USA; Department of Psychiatry, Yale University School of Medicine, 300 George Street, New Haven, CT 06510, USA
| | - Anna Chupak
- Alzheimer's Disease Research Unit, Yale University School of Medicine, One Church Street, 8(th) 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, 8(th) Floor, New Haven, CT 06510, USA; Department of Psychiatry, Yale University School of Medicine, 300 George Street, New Haven, CT 06510, USA
| | - Elaheh Salardini
- Alzheimer's Disease Research Unit, Yale University School of Medicine, One Church Street, 8(th) 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
| | - 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, 8(th) 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
| | - Adam P Mecca
- Alzheimer's Disease Research Unit, Yale University School of Medicine, One Church Street, 8(th) Floor, New Haven, CT 06510, USA; Department of Psychiatry, Yale University School of Medicine, 300 George Street, New Haven, CT 06510, USA.
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21
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Mikkelsen JD, Kaad S, Aripaka SS, Finsen B. Synaptic vesicle glycoprotein 2A (SV2A) levels in the cerebral cortex in patients with Alzheimer's disease: a radioligand binding study in postmortem brains. Neurobiol Aging 2023; 129:50-57. [PMID: 37269646 DOI: 10.1016/j.neurobiolaging.2023.05.003] [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: 12/02/2022] [Revised: 04/04/2023] [Accepted: 05/03/2023] [Indexed: 06/05/2023]
Abstract
Histological and biochemical analyses in postmortem tissues have demonstrated neurodegenerative changes in the cerebral cortex in patients with Alzheimer's disease (AD), and it has been suggested that this represents a loss of synapses. PET imaging of the (pre)synaptic vesicular glycoprotein 2A (SV2A) has demonstrated a reduction in synapse density in AD in the hippocampus but not consistently in the neocortex. This investigation examines the level of [3H]UCB-J binding in postmortem cortical tissue from patients with AD and matched healthy controls using autoradiography. Among the neocortical areas examined, the binding was significantly lower only in the middle frontal gyrus in AD compared to matched controls. No differences were observed in the parietal, temporal, or occipital cortex. The binding levels in the frontal cortex in the AD cohort displayed large variability among subjects, and this revealed a highly significant negative association with the age of the patient. These results demonstrate low UCB-J binding in the frontal cortex of patients with AD, and this biomarker correlates negatively with age, which may further indicate that SV2A could be an important biomarker in AD patients.
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Affiliation(s)
- Jens D Mikkelsen
- Neurobiology Research Unit, University Hospital Rigshospitalet, Copenhagen, Denmark; Institute of Neuroscience, University of Copenhagen, Copenhagen, Denmark; Department of Molecular Medicine, University of Southern Denmark, Odense, Denmark.
| | - Sif Kaad
- Neurobiology Research Unit, University Hospital Rigshospitalet, Copenhagen, Denmark
| | - Sanjay S Aripaka
- Neurobiology Research Unit, University Hospital Rigshospitalet, Copenhagen, Denmark
| | - Bente Finsen
- Department of Molecular Medicine, University of Southern Denmark, Odense, Denmark
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Hindley N, Sanchez Avila A, Henstridge C. Bringing synapses into focus: Recent advances in synaptic imaging and mass-spectrometry for studying synaptopathy. Front Synaptic Neurosci 2023; 15:1130198. [PMID: 37008679 PMCID: PMC10050382 DOI: 10.3389/fnsyn.2023.1130198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Accepted: 02/28/2023] [Indexed: 03/17/2023] Open
Abstract
Synapses are integral for healthy brain function and are becoming increasingly recognized as key structures in the early stages of brain disease. Understanding the pathological processes driving synaptic dysfunction will unlock new therapeutic opportunities for some of the most devastating diseases of our time. To achieve this we need a solid repertoire of imaging and molecular tools to interrogate synaptic biology at greater resolution. Synapses have historically been examined in small numbers, using highly technical imaging modalities, or in bulk, using crude molecular approaches. However, recent advances in imaging techniques are allowing us to analyze large numbers of synapses, at single-synapse resolution. Furthermore, multiplexing is now achievable with some of these approaches, meaning we can examine multiple proteins at individual synapses in intact tissue. New molecular techniques now allow accurate quantification of proteins from isolated synapses. The development of increasingly sensitive mass-spectrometry equipment means we can now scan the synaptic molecular landscape almost in totality and see how this changes in disease. As we embrace these new technical developments, synapses will be viewed with clearer focus, and the field of synaptopathy will become richer with insightful and high-quality data. Here, we will discuss some of the ways in which synaptic interrogation is being facilitated by methodological advances, focusing on imaging, and mass spectrometry.
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Affiliation(s)
- Nicole Hindley
- Division of Cellular and Systems Medicine, University of Dundee, Dundee, United Kingdom
- *Correspondence: Nicole Hindley,
| | - Anna Sanchez Avila
- Division of Cellular and Systems Medicine, University of Dundee, Dundee, United Kingdom
- Euan Macdonald Centre for Motor Neuron Disease, University of Edinburgh, Edinburgh, United Kingdom
| | - Christopher Henstridge
- Division of Cellular and Systems Medicine, University of Dundee, Dundee, United Kingdom
- Euan Macdonald Centre for Motor Neuron Disease, University of Edinburgh, Edinburgh, United Kingdom
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23
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Lopresti BJ, Royse SK, Mathis CA, Tollefson SA, Narendran R. Beyond monoamines: I. Novel targets and radiotracers for Positron emission tomography imaging in psychiatric disorders. J Neurochem 2023; 164:364-400. [PMID: 35536762 DOI: 10.1111/jnc.15615] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 04/05/2022] [Accepted: 04/06/2022] [Indexed: 10/18/2022]
Abstract
With the emergence of positron emission tomography (PET) in the late 1970s, psychiatry had access to a tool capable of non-invasive assessment of human brain function. Early applications in psychiatry focused on identifying characteristic brain blood flow and metabolic derangements using radiotracers such as [15 O]H2 O and [18 F]FDG. Despite the success of these techniques, it became apparent that more specific probes were needed to understand the neurochemical bases of psychiatric disorders. The first neurochemical PET imaging probes targeted sites of action of neuroleptic (dopamine D2 receptors) and psychoactive (serotonin receptors) drugs. Based on the centrality of monoamine dysfunction in psychiatric disorders and the measured success of monoamine-enhancing drugs in treating them, the next 30 years witnessed the development of an armamentarium of PET radiopharmaceuticals and imaging methodologies for studying monoamines. Continued development of monoamine-enhancing drugs over this time however was less successful, realizing only modest gains in efficacy and tolerability. As patent protection for many widely prescribed and profitable psychiatric drugs lapsed, drug development pipelines shifted away from monoamines in search of novel targets with the promises of improved efficacy, or abandoned altogether. Over this period, PET radiopharmaceutical development activities closely paralleled drug development priorities resulting in the development of new PET imaging agents for non-monoamine targets. Part one of this review will briefly survey novel PET imaging targets with relevance to the field of psychiatry, which include the metabotropic glutamate receptor type 5 (mGluR5), purinergic P2 X7 receptor, type 1 cannabinoid receptor (CB1 ), phosphodiesterase 10A (PDE10A), and describe radiotracers developed for these and other targets that have matured to human subject investigations. Current limitations of the targets and techniques will also be discussed.
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Affiliation(s)
- Brian J Lopresti
- Departments of Radiology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Sarah K Royse
- Departments of Radiology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Chester A Mathis
- Departments of Radiology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Savannah A Tollefson
- Departments of Radiology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Rajesh Narendran
- Departments of Radiology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA.,Departments of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
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Ribarič S. Detecting Early Cognitive Decline in Alzheimer's Disease with Brain Synaptic Structural and Functional Evaluation. Biomedicines 2023; 11:biomedicines11020355. [PMID: 36830892 PMCID: PMC9952956 DOI: 10.3390/biomedicines11020355] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 01/22/2023] [Accepted: 01/24/2023] [Indexed: 01/28/2023] Open
Abstract
Early cognitive decline in patients with Alzheimer's (AD) is associated with quantifiable structural and functional connectivity changes in the brain. AD dysregulation of Aβ and tau metabolism progressively disrupt normal synaptic function, leading to loss of synapses, decreased hippocampal synaptic density and early hippocampal atrophy. Advances in brain imaging techniques in living patients have enabled the transition from clinical signs and symptoms-based AD diagnosis to biomarkers-based diagnosis, with functional brain imaging techniques, quantitative EEG, and body fluids sampling. The hippocampus has a central role in semantic and episodic memory processing. This cognitive function is critically dependent on normal intrahippocampal connections and normal hippocampal functional connectivity with many cortical regions, including the perirhinal and the entorhinal cortex, parahippocampal cortex, association regions in the temporal and parietal lobes, and prefrontal cortex. Therefore, decreased hippocampal synaptic density is reflected in the altered functional connectivity of intrinsic brain networks (aka large-scale networks), including the parietal memory, default mode, and salience networks. This narrative review discusses recent critical issues related to detecting AD-associated early cognitive decline with brain synaptic structural and functional markers in high-risk or neuropsychologically diagnosed patients with subjective cognitive impairment or mild cognitive impairment.
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Affiliation(s)
- Samo Ribarič
- Faculty of Medicine, Institute of Pathophysiology, University of Ljubljana, Zaloška 4, SI-1000 Ljubljana, Slovenia
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25
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Oxidation-Cyclisation of Biphenyl Thioethers to Dibenzothiophenium Salts for Ultrarapid 18F-Labelling of PET Tracers. Int J Mol Sci 2022; 23:ijms232415481. [PMID: 36555122 PMCID: PMC9779140 DOI: 10.3390/ijms232415481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Revised: 11/25/2022] [Accepted: 12/01/2022] [Indexed: 12/12/2022] Open
Abstract
18F-labelled radiotracers are in high demand and play an important role for diagnostic imaging with positron emission tomography (PET). Challenges associated with the synthesis of the labelling precursors and the incorporation of [18F]fluoride with practical activity yields at batch scale are the main limitations for the development of new 18F-PET tracers. Herein, we report a high-yielding and robust synthetic method to access naked dibenzothiophenium salt precursors of complex PET tracers and their labelling with [18F]fluoride. C-S cross-coupling of biphenyl-2-thioacetate with aryl halides followed by sequential oxidation-cyclisation of the corresponding thioethers gives dibenzothiophenium salts in good to excellent yields. Labelling of neutral and electron-deficient substrates with [18F]fluoride is ultrarapid and occurs under mild conditions (1 min at 90 °C) with high activity yields. The method enables facile synthesis of complex and sensitive radiotracers, as exemplified by radiofluorination of three clinically relevant PET tracers [18F]UCB-J, [18F]AldoView and [18F]FNDP, and can accelerate the development and clinical translation of new 18F-radiopharmaceuticals.
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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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Correlation of Global and Regional Amyloid Burden by 18F-Florbetaben PET/CT With Cognitive Impairment Profile and Severity. Clin Nucl Med 2022; 47:923-930. [DOI: 10.1097/rlu.0000000000004370] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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28
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Vanderlinden G, Ceccarini J, Vande Casteele T, Michiels L, Lemmens R, Triau E, Serdons K, Tournoy J, Koole M, Vandenbulcke M, Van Laere K. Spatial decrease of synaptic density in amnestic mild cognitive impairment follows the tau build-up pattern. Mol Psychiatry 2022; 27:4244-4251. [PMID: 35794185 DOI: 10.1038/s41380-022-01672-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Revised: 06/03/2022] [Accepted: 06/10/2022] [Indexed: 02/07/2023]
Abstract
Next to amyloid and tau, synaptic loss is a key pathological hallmark in Alzheimer's disease, closely related to cognitive dysfunction and neurodegeneration. Tau is thought to cause synaptic loss, but this has not been experimentally verified in vivo. In a 2-year follow-up study, dual tracer PET-MR was performed in 12 amnestic MCI patients using 18F-MK-6240 for tau and 11C-UCB-J for SV2A as a proxy for synaptic density. Tau already accumulated in the neocortex at baseline with progression in Braak V/VI at follow-up. While synaptic loss was limited to limbic regions at baseline, it followed the specific tau pattern to stage IV/V regions two years later, indicating that tau spread might drive synaptic vulnerability. Moreover, synaptic density changes correlated to changes in cognitive function. This study shows for the first time in vivo that synaptic loss regionally follows tau accumulation after two years, providing a disease-modifying window of opportunity for (combined) tau-targeting therapies.
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Affiliation(s)
- Greet Vanderlinden
- Nuclear Medicine and Molecular Imaging, Imaging Pathology, KU Leuven, Leuven, Belgium.
| | - Jenny Ceccarini
- Nuclear Medicine and Molecular Imaging, Imaging Pathology, KU Leuven, Leuven, Belgium
| | - Thomas Vande Casteele
- Neuropsychiatry, Department of Neurosciences, Leuven Brain Institute, KU Leuven, Leuven, Belgium
| | - Laura Michiels
- Department of Neurosciences, KU Leuven, Leuven, Belgium.,Department of Neurology, University Hospitals UZ Leuven, Leuven, Belgium.,VIB, Center for Brain & Disease Research, Laboratory of Neurobiology, Leuven, Belgium
| | - Robin Lemmens
- Department of Neurosciences, KU Leuven, Leuven, Belgium.,Department of Neurology, University Hospitals UZ Leuven, Leuven, Belgium.,VIB, Center for Brain & Disease Research, Laboratory of Neurobiology, Leuven, Belgium
| | - Eric Triau
- Private Practice Neurology, Leuven, Belgium
| | - Kim Serdons
- Department of Nuclear Medicine, University Hospitals UZ Leuven, Leuven, Belgium
| | - Jos Tournoy
- Department of Geriatric Medicine, University Hospitals UZ Leuven, Leuven, Belgium.,Department of Public Health and Primary Care, Gerontology and Geriatrics, KU Leuven, Leuven, Belgium
| | - Michel Koole
- Nuclear Medicine and Molecular Imaging, Imaging Pathology, KU Leuven, Leuven, Belgium
| | - Mathieu Vandenbulcke
- Neuropsychiatry, Department of Neurosciences, Leuven Brain Institute, KU Leuven, Leuven, Belgium.,Department of Old-Age Psychiatry, University Hospitals UZ Leuven, Leuven, Belgium
| | - Koen Van Laere
- Nuclear Medicine and Molecular Imaging, Imaging Pathology, KU Leuven, Leuven, Belgium.,Department of Nuclear Medicine, University Hospitals UZ Leuven, Leuven, Belgium
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29
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Focal-type, but not Diffuse-type, Amyloid Beta Plaques are Correlated with Alzheimer's Neuropathology, Cognitive Dysfunction, and Neuroinflammation in the Human Hippocampus. Neurosci Bull 2022; 38:1125-1138. [PMID: 36028642 PMCID: PMC9554074 DOI: 10.1007/s12264-022-00927-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2021] [Accepted: 04/28/2022] [Indexed: 11/24/2022] Open
Abstract
Amyloid beta (Aβ) plaques are one of the hallmarks of Alzheimer’s disease (AD). However, currently available anti-amyloid therapies fail to show effectiveness in the treatment of AD in humans. It has been found that there are different types of Aβ plaque (diffuse and focal types) in the postmortem human brain. In this study, we aimed to investigate the correlations among different types of Aβ plaque and AD-related neuropathological and cognitive changes based on a postmortem human brain bank in China. The results indicated that focal plaques, but not diffuse plaques, significantly increased with age in the human hippocampus. We also found that the number of focal plaques was positively correlated with the severity of AD-related neuropathological changes (measured by the “ABC” scoring system) and cognitive decline (measured by the Everyday Cognitive Insider Questionnaire). Furthermore, most of the focal plaques were co-localized with neuritic plaques (identified by Bielschowsky silver staining) and accompanied by microglial and other inflammatory cells. Our findings suggest the potential of using focal-type but not general Aβ plaques as biomarkers for the neuropathological evaluation of AD.
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30
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Hansen JY, Shafiei G, Vogel JW, Smart K, Bearden CE, Hoogman M, Franke B, van Rooij D, Buitelaar J, McDonald CR, Sisodiya SM, Schmaal L, Veltman DJ, van den Heuvel OA, Stein DJ, van Erp TGM, Ching CRK, Andreassen OA, Hajek T, Opel N, Modinos G, Aleman A, van der Werf Y, Jahanshad N, Thomopoulos SI, Thompson PM, Carson RE, Dagher A, Misic B. Local molecular and global connectomic contributions to cross-disorder cortical abnormalities. Nat Commun 2022; 13:4682. [PMID: 35948562 PMCID: PMC9365855 DOI: 10.1038/s41467-022-32420-y] [Citation(s) in RCA: 29] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Accepted: 07/28/2022] [Indexed: 12/21/2022] Open
Abstract
Numerous brain disorders demonstrate structural brain abnormalities, which are thought to arise from molecular perturbations or connectome miswiring. The unique and shared contributions of these molecular and connectomic vulnerabilities to brain disorders remain unknown, and has yet to be studied in a single multi-disorder framework. Using MRI morphometry from the ENIGMA consortium, we construct maps of cortical abnormalities for thirteen neurodevelopmental, neurological, and psychiatric disorders from N = 21,000 participants and N = 26,000 controls, collected using a harmonised processing protocol. We systematically compare cortical maps to multiple micro-architectural measures, including gene expression, neurotransmitter density, metabolism, and myelination (molecular vulnerability), as well as global connectomic measures including number of connections, centrality, and connection diversity (connectomic vulnerability). We find a relationship between molecular vulnerability and white-matter architecture that drives cortical disorder profiles. Local attributes, particularly neurotransmitter receptor profiles, constitute the best predictors of both disorder-specific cortical morphology and cross-disorder similarity. Finally, we find that cross-disorder abnormalities are consistently subtended by a small subset of network epicentres in bilateral sensory-motor, inferior temporal lobe, precuneus, and superior parietal cortex. Collectively, our results highlight how local molecular attributes and global connectivity jointly shape cross-disorder cortical abnormalities.
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Affiliation(s)
- Justine Y Hansen
- McConnell Brain Imaging Centre, Montréal Neurological Institute, McGill University, Montréal, QC, Canada
| | - Golia Shafiei
- McConnell Brain Imaging Centre, Montréal Neurological Institute, McGill University, Montréal, QC, Canada
| | - Jacob W Vogel
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Kelly Smart
- Department of Radiology and Biomedical Imaging, Yale School of Medicine, New Haven, CT, 06520, USA
| | - Carrie E Bearden
- Departments of Psychiatry and Biobehavioral Sciences and Psychology, Semel Institute for Neuroscience and Human Behavior, University of California, Los Angeles, CA, USA
| | - Martine Hoogman
- Departments of Psychiatry and Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition and Behavior, Radboud University, Nijmegen, The Netherlands
| | - Barbara Franke
- Departments of Psychiatry and Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition and Behavior, Radboud University, Nijmegen, The Netherlands
| | - Daan van Rooij
- Donders Institute for Brain, Cognition and Behavior, Radboud University, Nijmegen, The Netherlands
| | - Jan Buitelaar
- Donders Institute for Brain, Cognition and Behavior, Radboud University, Nijmegen, The Netherlands
| | - Carrie R McDonald
- Department of Psychiatry, University of California San Diego, La Jolla, CA, USA
| | - Sanjay M Sisodiya
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, WC1N 3BG, UK
| | - Lianne Schmaal
- Centre for Youth Mental Health, The University of Melbourne, Melbourne, VIC, Australia
| | - Dick J Veltman
- Department of Psychiatry, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam Neuroscience, Amsterdam, The Netherlands
| | - Odile A van den Heuvel
- Department of Psychiatry, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam Neuroscience, Amsterdam, The Netherlands
- Department of Anatomy & Neuroscience, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam Neuroscience, Amsterdam, the Netherlands
| | - Dan J Stein
- SA MRC Unit on Risk & Resilience in Mental Disorders, Dept of Psychiatry & Neuroscience Institute, University of Cape Town, Cape Town, South Africa
| | - Theo G M van Erp
- Clinical Translational Neuroscience Laboratory, Department of Psychiatry and Human Behavior, & Center for the Neurobiology of Leaning and Memory, University of California Irvine, 309 Qureshey Research Lab, Irvine, CA, USA
| | - Christopher R K Ching
- Keck School of Medicine, Imaging Genetics Center, Mark and Mary Stevens Neuroimaging and Informatics Institute, University of Southern California, Los Angeles, CA, USA
| | - Ole A Andreassen
- NORMENT Centre, Institute of Clinical Medicine, University of Oslo and Division of Mental Health and Addiction, Oslo University Hospital, Oslo, Norway
| | - Tomas Hajek
- Department of Psychiatry, Dalhousie University, Halifax, NS, Canada
| | - Nils Opel
- Institute of Translational Psychiatry, University of Münster, Münster, Germany & Department of Psychiatry, Jena University Hospital/Friedrich-Schiller-University Jena, Jena, Germany
| | - Gemma Modinos
- Department of Psychosis Studies & MRC Centre for Neurodevelopmental Disorders, King's College London, London, UK
| | - André Aleman
- Department of Biomedical Sciences of Cells and Systems, University of Groningen, Groningen, The Netherlands
| | - Ysbrand van der Werf
- Department of Anatomy & Neuroscience, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam Neuroscience, Amsterdam, the Netherlands
| | - Neda Jahanshad
- Keck School of Medicine, Imaging Genetics Center, Mark and Mary Stevens Neuroimaging and Informatics Institute, University of Southern California, Los Angeles, CA, USA
| | - Sophia I Thomopoulos
- Keck School of Medicine, Imaging Genetics Center, Mark and Mary Stevens Neuroimaging and Informatics Institute, University of Southern California, Los Angeles, CA, USA
| | - Paul M Thompson
- Keck School of Medicine, Imaging Genetics Center, Mark and Mary Stevens Neuroimaging and Informatics Institute, University of Southern California, Los Angeles, CA, USA
| | - Richard E Carson
- Department of Radiology and Biomedical Imaging, Yale School of Medicine, New Haven, CT, 06520, USA
| | - Alain Dagher
- McConnell Brain Imaging Centre, Montréal Neurological Institute, McGill University, Montréal, QC, Canada
| | - Bratislav Misic
- McConnell Brain Imaging Centre, Montréal Neurological Institute, McGill University, Montréal, QC, Canada.
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32
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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: 32] [Impact Index Per Article: 16.0] [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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33
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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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34
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Serrano ME, Kim E, Petrinovic MM, Turkheimer F, Cash D. Imaging Synaptic Density: The Next Holy Grail of Neuroscience? Front Neurosci 2022; 16:796129. [PMID: 35401097 PMCID: PMC8990757 DOI: 10.3389/fnins.2022.796129] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Accepted: 02/15/2022] [Indexed: 12/19/2022] Open
Abstract
The brain is the central and most complex organ in the nervous system, comprising billions of neurons that constantly communicate through trillions of connections called synapses. Despite being formed mainly during prenatal and early postnatal development, synapses are continually refined and eliminated throughout life via complicated and hitherto incompletely understood mechanisms. Failure to correctly regulate the numbers and distribution of synapses has been associated with many neurological and psychiatric disorders, including autism, epilepsy, Alzheimer’s disease, and schizophrenia. Therefore, measurements of brain synaptic density, as well as early detection of synaptic dysfunction, are essential for understanding normal and abnormal brain development. To date, multiple synaptic density markers have been proposed and investigated in experimental models of brain disorders. The majority of the gold standard methodologies (e.g., electron microscopy or immunohistochemistry) visualize synapses or measure changes in pre- and postsynaptic proteins ex vivo. However, the invasive nature of these classic methodologies precludes their use in living organisms. The recent development of positron emission tomography (PET) tracers [such as (18F)UCB-H or (11C)UCB-J] that bind to a putative synaptic density marker, the synaptic vesicle 2A (SV2A) protein, is heralding a likely paradigm shift in detecting synaptic alterations in patients. Despite their limited specificity, novel, non-invasive magnetic resonance (MR)-based methods also show promise in inferring synaptic information by linking to glutamate neurotransmission. Although promising, all these methods entail various advantages and limitations that must be addressed before becoming part of routine clinical practice. In this review, we summarize and discuss current ex vivo and in vivo methods of quantifying synaptic density, including an evaluation of their reliability and experimental utility. We conclude with a critical assessment of challenges that need to be overcome before successfully employing synaptic density biomarkers as diagnostic and/or prognostic tools in the study of neurological and neuropsychiatric disorders.
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Affiliation(s)
- Maria Elisa Serrano
- Department of Neuroimaging, The BRAIN Centre, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom.,Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, Kings College London, London, United Kingdom
| | - Eugene Kim
- Department of Neuroimaging, The BRAIN Centre, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom.,Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, Kings College London, London, United Kingdom
| | - Marija M Petrinovic
- Department of Forensic and Neurodevelopmental Sciences, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom.,MRC Centre for Neurodevelopmental Disorders, King's College London, London, United Kingdom
| | - Federico Turkheimer
- Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, Kings College London, London, United Kingdom
| | - Diana Cash
- Department of Neuroimaging, The BRAIN Centre, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom.,Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, Kings College London, London, United Kingdom
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35
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Bashir S, Uzair M, Abualait T, Arshad M, Khallaf RA, Niaz A, Thani Z, Yoo WK, Túnez I, Demirtas-Tatlidede A, Meo SA. Effects of transcranial magnetic stimulation on neurobiological changes in Alzheimer's disease (Review). Mol Med Rep 2022; 25:109. [PMID: 35119081 PMCID: PMC8845030 DOI: 10.3892/mmr.2022.12625] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Accepted: 12/15/2021] [Indexed: 11/05/2022] Open
Abstract
Alzheimer's disease (AD) is a neurodegenerative disorder characterized by cognitive decline and brain neuronal loss. A pioneering field of research in AD is brain stimulation via electromagnetic fields (EMFs), which may produce clinical benefits. Noninvasive brain stimulation techniques, such as transcranial magnetic stimulation (TMS), have been developed to treat neurological and psychiatric disorders. The purpose of the present review is to identify neurobiological changes, including inflammatory, neurodegenerative, apoptotic, neuroprotective and genetic changes, which are associated with repetitive TMS (rTMS) treatment in patients with AD. Furthermore, it aims to evaluate the effect of TMS treatment in patients with AD and to identify the associated mechanisms. The present review highlights the changes in inflammatory and apoptotic mechanisms, mitochondrial enzymatic activities, and modulation of gene expression (microRNA expression profiles) associated with rTMS or sham procedures. At the molecular level, it has been suggested that EMFs generated by TMS may affect the cell redox status and amyloidogenic processes. TMS may also modulate gene expression by acting on both transcriptional and post‑transcriptional regulatory mechanisms. TMS may increase brain cortical excitability, induce specific potentiation phenomena, and promote synaptic plasticity and recovery of impaired functions; thus, it may re‑establish cognitive performance in patients with AD.
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Affiliation(s)
- Shahid Bashir
- Neuroscience Center, King Fahad Specialist Hospital Dammam, Dammam, Eastern Province 32253, Saudi Arabia
| | - Mohammad Uzair
- Department of Biological Sciences, Faculty of Basic and Applied Sciences, International Islamic University Islamabad, Islamabad 44000, Pakistan
| | - Turki Abualait
- College of Applied Medical Sciences, Imam Abdulrahman Bin Faisal University, Dammam, Eastern Province 34212, Saudi Arabia
| | - Muhammad Arshad
- Department of Biological Sciences, Faculty of Basic and Applied Sciences, International Islamic University Islamabad, Islamabad 44000, Pakistan
| | - Roaa A. Khallaf
- Neuroscience Center, King Fahad Specialist Hospital Dammam, Dammam, Eastern Province 32253, Saudi Arabia
| | - Asim Niaz
- Neuroscience Center, King Fahad Specialist Hospital Dammam, Dammam, Eastern Province 32253, Saudi Arabia
| | - Ziyad Thani
- Neuroscience Center, King Fahad Specialist Hospital Dammam, Dammam, Eastern Province 32253, Saudi Arabia
| | - Woo-Kyoung Yoo
- Department of Physical Medicine and Rehabilitation, Hallym University College of Medicine, Anyang, Gyeonggi-do 24252, Republic of Korea
| | - Isaac Túnez
- Department of Biochemistry and Molecular Biology, Faculty of Medicine and Nursing/ Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC), University of Cordoba, Cordoba 14071, Spain
- Cooperative Research Thematic Excellent Network on Brain Stimulation (REDESTIM), Ministry for Economy, Industry and Competitiveness, 28046 Madrid, Spain
| | | | - Sultan Ayoub Meo
- Department of Physiology, College of Medicine, King Saud University, Riyadh 11451, Saudi Arabia
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36
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Chételat G. How to use neuroimaging biomarkers in the diagnosis framework of neurodegenerative diseases? Rev Neurol (Paris) 2022; 178:490-497. [DOI: 10.1016/j.neurol.2022.03.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Revised: 03/08/2022] [Accepted: 03/08/2022] [Indexed: 11/29/2022]
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37
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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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Chaudhary S, Zhornitsky S, Chao HH, van Dyck CH, Li CSR. Hypothalamic Functional Connectivity and Apathy in People with Alzheimer's Disease and Cognitively Normal Healthy Controls. J Alzheimers Dis 2022; 90:1615-1628. [PMID: 36314209 PMCID: PMC10064487 DOI: 10.3233/jad-220708] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
BACKGROUND Earlier studies have described the neural markers of apathy in Alzheimer's disease (AD) and mild cognitive impairment (MCI), but few focused on the motivation circuits. Here, we targeted hypothalamus, a hub of the motivation circuit. OBJECTIVE To examine hypothalamic resting state functional connectivity (rsFC) in relation to apathy. METHODS We performed whole-brain regression of hypothalamic rsFC against Apathy Evaluation Scale (AES) total score and behavioral, cognitive, and emotional subscores in 29 patients with AD/MCI and 28 healthy controls (HC), controlling for age, sex, education, cognitive status, and depression. We evaluated the results at a corrected threshold and employed path analyses to assess possible interaction between hypothalamic rsFCs, apathy and depression/memory. Finally, we re-examined the findings in a subsample of amyloid-β-verified AD. RESULTS AES total score correlated negatively with hypothalamic precuneus (PCu)/posterior cingulate cortex (PCC) and positively with left middle temporal gyrus (MTG) and supramarginal gyrus rsFCs. Behavioral subscore correlated negatively with hypothalamic PCu/PCC and positively with middle frontal gyrus rsFC. Cognitive subscore correlated positively with hypothalamic MTG rsFC. Emotional subscore correlated negatively with hypothalamic calcarine cortex rsFC. In path analyses, hypothalamic-PCu/PCC rsFC negatively modulated apathy and, in turn, depression. The model where hypothalamic MTG rsFC and memory independently modulated apathy also showed a good fit. The findings of diminished hypothalamic-PCu/PCC rsFC in relation to apathy and, in turn, depression were confirmed in amyloid-verified AD. CONCLUSION The findings together support a role of altered hypothalamic connectivity in relation to apathy and depression, and modulation of apathy by memory dysfunction.
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Affiliation(s)
- Shefali Chaudhary
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
| | - Simon Zhornitsky
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
| | - Herta H Chao
- VA Connecticut Healthcare System, West Haven, CT, USA.,Department of Medicine & Yale Comprehensive Cancer Center, Yale University School of Medicine, New Haven, CT, USA
| | - Christopher H van Dyck
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA.,Alzheimer's Disease Research Unit, Yale University School of Medicine, New Haven, CT, USA.,Department of Neuroscience, Yale University School of Medicine, New Haven, CT, USA.,Interdepartmental Neuroscience Program, Yale University School of Medicine, New Haven, CT, USA
| | - Chiang-Shan R Li
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA.,Department of Neuroscience, Yale University School of Medicine, New Haven, CT, USA.,Interdepartmental Neuroscience Program, Yale University School of Medicine, New Haven, CT, USA.,Wu Tsai Institute, Yale University, New Haven, CT, USA
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Chaudhary S, Zhornitsky S, Chao HH, van Dyck CH, Li CSR. Cerebral Volumetric Correlates of Apathy in Alzheimer's Disease and Cognitively Normal Older Adults: Meta-Analysis, Label-Based Review, and Study of an Independent Cohort. J Alzheimers Dis 2022; 85:1251-1265. [PMID: 34924392 PMCID: PMC9215906 DOI: 10.3233/jad-215316] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
BACKGROUND Affecting nearly half of the patients with Alzheimer's disease (AD), apathy is associated with higher morbidity and reduced quality of life. Basal ganglia and cortical atrophy have been implicated in apathy. However, the findings have varied across studies and left unclear whether subdomains of apathy may involve distinct neuroanatomical correlates. OBJECTIVE To identify neuroanatomical correlates of AD-associated apathy. METHODS We performed a meta-analysis and label-based review of the literature. Further, following published routines of voxel-based morphometry, we aimed to confirm the findings in an independent cohort of 19 patients with AD/mild cognitive impairment and 25 healthy controls assessed with the Apathy Evaluation Scale. RESULTS Meta-analysis of 167 AD and 56 healthy controls showed convergence toward smaller basal ganglia gray matter volume (GMV) in apathy. Label-based review showed anterior cingulate, putamen, insula, inferior frontal gyrus (IFG) and middle temporal gyrus (MTG) atrophy in AD apathy. In the independent cohort, with small-volume-correction, right putamen and MTG showed GMVs in negative correlation with Apathy Evaluation Scale total, behavioral, and emotional scores, and right IFG with emotional score (p < 0.05 family-wise error (FWE)-corrected), controlling for age, education, intracranial volume, and depression. With the Mini-Mental State Examination scores included as an additional covariate, the correlation of right putamen GMV with behavioral and emotional score, right MTG GMV with total and emotional score, and right IFG GMV with emotional score were significant. CONCLUSION The findings implicate putamen, MTG and IFG atrophy in AD associated apathy, potentially independent of cognitive impairment and depression, and suggest potentially distinct volumetric correlates of apathy.
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Affiliation(s)
- Shefali Chaudhary
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT 06519
| | - Simon Zhornitsky
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT 06519
| | - Herta H. Chao
- Comprehensive Cancer Center, Department of Medicine, Yale University School of Medicine, New Haven, CT 06519
| | - Christopher H. van Dyck
- Disease Research Center, Department of Psychiatry; Department of Neuroscience; Interdepartmental Neuroscience, Program, Yale University School of Medicine, New Haven, CT 06520
| | - Chiang-Shan R. Li
- Department of Psychiatry; Department of Neuroscience; Interdepartmental Neuroscience, Program, Wu Tsai Institute, Yale University, Yale University School of Medicine, New Haven, CT 06520
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40
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Xu B, He Y, Liu L, Ye G, Chen L, Wang Q, Chen M, Chen Y, Long D. The Effects of Physical Running on Dendritic Spines and Amyloid-beta Pathology in 3xTg-AD Male Mice. Aging Dis 2022; 13:1293-1310. [PMID: 35855335 PMCID: PMC9286906 DOI: 10.14336/ad.2022.0110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Accepted: 01/10/2022] [Indexed: 11/01/2022] Open
Abstract
Memory loss is the key symptom of Alzheimer's disease (AD). As successful drug treatments have not yet been identified, non-pharmaceutical interventions such as physical exercise and training have been employed to improve the memory function of people with dementia. We investigated the effect of prolonged physical running on hippocampal-dependent spatial memory and its underlying mechanisms using a well-established rodent model of AD. 3xTg-AD transgenic mice and non-transgenic mice were subjected to voluntary wheel running for 5 months (1 hour per day, 5 days per week), followed by spatial memory testing. After the behavioral testing, dendritic spines, synapses, and synaptic proteins as well as amyloid-beta (Aβ) pathology were analyzed in the dorsal hippocampi. Running improved hippocampal-dependent spatial memory in 3xTg-AD mice. This running strategy prevented both thin and mushroom-type spines on CA1 pyramidal cells in 3xTg-AD mice, whereas the effects of running in non-transgenic mice were limited to thin spines. The enormous effects of running on spines were accompanied by an increased number of synapses and upregulated expression of synaptic proteins. Notably, running downregulated the processing of amyloid precursor protein, decreasing intracellular APP expression and extracellular Aβ accumulation, and spatial memory performance correlated with levels of Aβ peptides Aβ1-40 and Aβ1-42. These data suggest that prolonged running may improve memory in preclinical AD via slowing down the amyloid pathology and preventing the loss of synaptic contacts.
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Affiliation(s)
- Benke Xu
- Department of Human Anatomy, School of Basic Medical Sciences, Yangtze University, Hubei 434023, China.
| | - Yun He
- Department of Human Anatomy, School of Basic Medical Sciences, Yangtze University, Hubei 434023, China.
| | - Lian Liu
- Department of Pharmacology, School of Basic Medical Sciences, Yangtze University, Hubei 434023, China.
| | - Guosheng Ye
- Key Lab of Neuroscience, School of Basic Medical Sciences, Guangzhou Medical University, Guangzhou 511436, China.
| | - Lulu Chen
- Key Lab of Neuroscience, School of Basic Medical Sciences, Guangzhou Medical University, Guangzhou 511436, China.
| | - Qingning Wang
- Key Lab of Neuroscience, School of Basic Medical Sciences, Guangzhou Medical University, Guangzhou 511436, China.
| | - Michael Chen
- University of California, Los Angeles, CA 90095, USA.
| | - Yuncai Chen
- Department of Pediatrics, University of California, Irvine, CA 92697, USA.
- Correspondence should be addressed to: Dr. Dahong Long, Key Lab of Neuroscience, School of Basic Medical Sciences, Guangzhou Medical University, Guangzhou 511436, China. E-mail: or Dr. Yuncai Chen, Department of Pediatrics, University of California-Irvine, Irvine, California 92697, USA. E-mail:
| | - Dahong Long
- Key Lab of Neuroscience, School of Basic Medical Sciences, Guangzhou Medical University, Guangzhou 511436, China.
- Correspondence should be addressed to: Dr. Dahong Long, Key Lab of Neuroscience, School of Basic Medical Sciences, Guangzhou Medical University, Guangzhou 511436, China. E-mail: or Dr. Yuncai Chen, Department of Pediatrics, University of California-Irvine, Irvine, California 92697, USA. E-mail:
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41
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Möck EEA, Honkonen E, Airas L. Synaptic Loss in Multiple Sclerosis: A Systematic Review of Human Post-mortem Studies. Front Neurol 2021; 12:782599. [PMID: 34912290 PMCID: PMC8666414 DOI: 10.3389/fneur.2021.782599] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Accepted: 10/26/2021] [Indexed: 11/13/2022] Open
Abstract
Background: Gray matter pathology plays a central role in the progression of multiple sclerosis (MS). The occurrence of synaptic loss appears to be important but, to date, still poorly investigated aspect of MS pathology. In this systematic review, we drew from the recent knowledge about synaptic loss in human post-mortem studies. Methods: We conducted a systematic search with PubMed to identify relevant publications. Publications available from15 June 2021 were taken into account. We selected human post-mortem studies that quantitatively assessed the synapse number in MS tissue. Results: We identified 14 relevant publications out of which 9 reported synaptic loss in at least one investigated subregion. The most commonly used synaptic marker was synaptophysin; non-etheless, we found substantial differences in the methodology and the selection of reference tissue. Investigated regions included the cortex, the hippocampus, the cerebellum, the thalamus, and the spinal cord. Conclusion: Synaptic loss seems to take place throughout the entire central nervous system. However, the results are inconsistent, probably due to differences in the methodology. Moreover, synaptic loss appears to be a dynamic process, and thus the nature of this pathology might be captured using in vivo synaptic density measurements.
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Affiliation(s)
- E E Amelie Möck
- Division of Clinical Neurosciences, Turku University Hospital and University of Turku, Turku, Finland.,Turku PET Centre, Turku University Hospital and University of Turku, Turku, Finland
| | - Eveliina Honkonen
- Division of Clinical Neurosciences, Turku University Hospital and University of Turku, Turku, Finland.,Turku PET Centre, Turku University Hospital and University of Turku, Turku, Finland
| | - Laura Airas
- Division of Clinical Neurosciences, Turku University Hospital and University of Turku, Turku, Finland.,Turku PET Centre, Turku University Hospital and University of Turku, Turku, Finland
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42
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Raval NR, Gudmundsen F, Juhl M, Andersen IV, Speth N, Videbæk A, Petersen IN, Mikkelsen JD, Fisher PM, Herth MM, Plavén-Sigray P, Knudsen GM, Palner M. Synaptic Density and Neuronal Metabolic Function Measured by Positron Emission Tomography in the Unilateral 6-OHDA Rat Model of Parkinson's Disease. Front Synaptic Neurosci 2021; 13:715811. [PMID: 34867258 PMCID: PMC8636601 DOI: 10.3389/fnsyn.2021.715811] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Accepted: 10/06/2021] [Indexed: 11/30/2022] Open
Abstract
Parkinson’s disease (PD) is caused by progressive neurodegeneration and characterised by motor dysfunction. Neurodegeneration of dopaminergic neurons also causes aberrations within the cortico-striato-thalamo-cortical (CSTC) circuit, which has been hypothesised to lead to non-motor symptoms such as depression. Individuals with PD have both lower synaptic density and changes in neuronal metabolic function in the basal ganglia, as measured using [11C]UCB-J and [18F]FDG positron emission tomography (PET), respectively. However, the two radioligands have not been directly compared in the same PD subject or in neurodegeneration animal models. Here, we investigate [11C]UCB-J binding and [18F]FDG uptake in the CSTC circuit following a unilateral dopaminergic lesion in rats and compare it to sham lesioned rats. Rats received either a unilateral injection of 6-hydroxydopamine (6-OHDA) or saline in the medial forebrain bundle and rostral substantia nigra (n = 4/group). After 3 weeks, all rats underwent two PET scans using [18F]FDG, followed by [11C]UCB-J on a separate day. [18F]FDG uptake and [11C]UCB-J binding were both lower in the ipsilateral striatal regions compared to the contralateral regions. Using [11C]UCB-J, we could detect an 8.7% decrease in the ipsilateral ventral midbrain, compared to a 2.9% decrease in ventral midbrain using [18F]FDG. Differential changes between hemispheres for [11C]UCB-J and [18F]FDG outcomes were also evident in the CSTC circuit’s cortical regions, especially in the orbitofrontal cortex and medial prefrontal cortex where higher synaptic density yet lower neuronal metabolic function was observed, following lesioning. In conclusion, [11C]UCB-J and [18F]FDG PET can detect divergent changes following a dopaminergic lesion in rats, especially in cortical regions that are not directly affected by the neurotoxin. These results suggest that combined [11C]UCB-J and [18F]FDG scans could yield a better picture of the heterogeneous cerebral changes in neurodegenerative disorders.
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Affiliation(s)
- Nakul Ravi Raval
- Neurobiology Research Unit, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark.,Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Frederik Gudmundsen
- Neurobiology Research Unit, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | - Morten Juhl
- Cardiology Stem Cell Centre, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | - Ida Vang Andersen
- Neurobiology Research Unit, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark.,Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Nikolaj Speth
- Neurobiology Research Unit, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | - Annesofie Videbæk
- Neurobiology Research Unit, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | - Ida Nymann Petersen
- Department of Clinical Physiology, Nuclear Medicine & PET, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | - Jens D Mikkelsen
- Neurobiology Research Unit, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark.,Department of Neuroscience, University of Copenhagen, Copenhagen, Denmark
| | | | - Matthias Manfred Herth
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,Department of Clinical Physiology, Nuclear Medicine & PET, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | - Pontus Plavén-Sigray
- Neurobiology Research Unit, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | - Gitte Moos Knudsen
- Neurobiology Research Unit, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark.,Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Mikael Palner
- Neurobiology Research Unit, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark.,Clinical Physiology and Nuclear Medicine, Department of Clinical Research, University of Southern Denmark, Odense, Denmark.,Department of Nuclear Medicine, Odense University Hospital, Odense, Denmark
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43
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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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Ni R. Positron Emission Tomography in Animal Models of Alzheimer's Disease Amyloidosis: Translational Implications. Pharmaceuticals (Basel) 2021; 14:1179. [PMID: 34832961 PMCID: PMC8623863 DOI: 10.3390/ph14111179] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Revised: 11/13/2021] [Accepted: 11/15/2021] [Indexed: 12/30/2022] Open
Abstract
Animal models of Alzheimer's disease amyloidosis that recapitulate cerebral amyloid-beta pathology have been widely used in preclinical research and have greatly enabled the mechanistic understanding of Alzheimer's disease and the development of therapeutics. Comprehensive deep phenotyping of the pathophysiological and biochemical features in these animal models is essential. Recent advances in positron emission tomography have allowed the non-invasive visualization of the alterations in the brain of animal models and in patients with Alzheimer's disease. These tools have facilitated our understanding of disease mechanisms and provided longitudinal monitoring of treatment effects in animal models of Alzheimer's disease amyloidosis. In this review, we focus on recent positron emission tomography studies of cerebral amyloid-beta accumulation, hypoglucose metabolism, synaptic and neurotransmitter receptor deficits (cholinergic and glutamatergic system), blood-brain barrier impairment, and neuroinflammation (microgliosis and astrocytosis) in animal models of Alzheimer's disease amyloidosis. We further propose the emerging targets and tracers for reflecting the pathophysiological changes and discuss outstanding challenges in disease animal models and future outlook in the on-chip characterization of imaging biomarkers towards clinical translation.
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Affiliation(s)
- Ruiqing Ni
- Institute for Biomedical Engineering, ETH & University of Zurich, 8093 Zurich, Switzerland;
- Institute for Regenerative Medicine, University of Zurich, 8952 Zurich, Switzerland
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Pursuit of precision medicine: Systems biology approaches in Alzheimer's disease mouse models. Neurobiol Dis 2021; 161:105558. [PMID: 34767943 PMCID: PMC10112395 DOI: 10.1016/j.nbd.2021.105558] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 11/05/2021] [Accepted: 11/08/2021] [Indexed: 12/12/2022] Open
Abstract
Alzheimer's disease (AD) is a complex disease that is mediated by numerous factors and manifests in various forms. A systems biology approach to studying AD involves analyses of various body systems, biological scales, environmental elements, and clinical outcomes to understand the genotype to phenotype relationship that potentially drives AD development. Currently, there are many research investigations probing how modifiable and nonmodifiable factors impact AD symptom presentation. This review specifically focuses on how imaging modalities can be integrated into systems biology approaches using model mouse populations to link brain level functional and structural changes to disease onset and progression. Combining imaging and omics data promotes the classification of AD into subtypes and paves the way for precision medicine solutions to prevent and treat AD.
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46
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Kong Y, Zhang S, Huang L, Zhang C, Xie F, Zhang Z, Huang Q, Jiang D, Li J, Zhou W, Hua T, Sun B, Wang J, Guan Y. Positron Emission Computed Tomography Imaging of Synaptic Vesicle Glycoprotein 2A in Alzheimer's Disease. Front Aging Neurosci 2021; 13:731114. [PMID: 34795573 PMCID: PMC8593388 DOI: 10.3389/fnagi.2021.731114] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2021] [Accepted: 10/11/2021] [Indexed: 12/16/2022] Open
Abstract
Alzheimer's disease (AD) is the most common neurodegenerative disorder seen in age-dependent dementia. There is currently no effective treatment for AD, which may be attributed in part to lack of a clear underlying mechanism. Early diagnosis of AD is of great significance to control the development of the disease. Synaptic loss is an important pathology in the early stage of AD, therefore the measurement of synaptic density using molecular imaging technology may be an effective way to early diagnosis of AD. Synaptic vesicle glycoprotein 2A (SV2A) is located in the presynaptic vesicle membrane of virtually all synapses. SV2A Positron Emission Computed Tomography (PET) could provide a way to measure synaptic density quantitatively in living humans and to track changes in synaptic density in AD. In view of the fact that synaptic loss is the pathology of both epilepsy and AD, this review summarizes the potential role of SV2A in the pathogenesis of AD, and suggests that SV2A should be used as an important target molecule of PET imaging agent for the early diagnosis of AD.
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Affiliation(s)
- Yanyan Kong
- PET Center, Huashan Hospital, Fudan University, Shanghai, China
| | - Shibo Zhang
- Laboratory of Molecular Neural Biology, School of Life Sciences, Shanghai University, Shanghai, China
| | - Lin Huang
- Laboratory of Molecular Neural Biology, School of Life Sciences, Shanghai University, Shanghai, China
| | - Chencheng Zhang
- Department of Neurosurgery, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Fang Xie
- PET Center, Huashan Hospital, Fudan University, Shanghai, China
| | - Zhengwei Zhang
- PET Center, Huashan Hospital, Fudan University, Shanghai, China
| | - Qi Huang
- PET Center, Huashan Hospital, Fudan University, Shanghai, China
| | - Donglang Jiang
- PET Center, Huashan Hospital, Fudan University, Shanghai, China
| | - Junpeng Li
- PET Center, Huashan Hospital, Fudan University, Shanghai, China
| | - Weiyan Zhou
- PET Center, Huashan Hospital, Fudan University, Shanghai, China
| | - Tao Hua
- PET Center, Huashan Hospital, Fudan University, Shanghai, China
| | - Bomin Sun
- Department of Neurosurgery, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Jiao Wang
- Laboratory of Molecular Neural Biology, School of Life Sciences, Shanghai University, Shanghai, China
| | - Yihui Guan
- PET Center, Huashan Hospital, Fudan University, Shanghai, China
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47
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Czapski GA, Strosznajder JB. Glutamate and GABA in Microglia-Neuron Cross-Talk in Alzheimer's Disease. Int J Mol Sci 2021; 22:ijms222111677. [PMID: 34769106 PMCID: PMC8584169 DOI: 10.3390/ijms222111677] [Citation(s) in RCA: 56] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Revised: 10/19/2021] [Accepted: 10/21/2021] [Indexed: 12/18/2022] Open
Abstract
The physiological balance between excitation and inhibition in the brain is significantly affected in Alzheimer’s disease (AD). Several neuroactive compounds and their signaling pathways through various types of receptors are crucial in brain homeostasis, among them glutamate and γ-aminobutyric acid (GABA). Activation of microglial receptors regulates the immunological response of these cells, which in AD could be neuroprotective or neurotoxic. The novel research approaches revealed the complexity of microglial function, including the interplay with other cells during neuroinflammation and in the AD brain. The purpose of this review is to describe the role of several proteins and multiple receptors on microglia and neurons, and their involvement in a communication network between cells that could lead to different metabolic loops and cell death/survival. Our review is focused on the role of glutamatergic, GABAergic signaling in microglia–neuronal cross-talk in AD and neuroinflammation. Moreover, the significance of AD-related neurotoxic proteins in glutamate/GABA-mediated dialogue between microglia and neurons was analyzed in search of novel targets in neuroprotection, and advanced pharmacological approaches.
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48
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Andersen KB, Hansen AK, Damholdt MF, Horsager J, Skjaerbaek C, Gottrup H, Klit H, Schacht AC, Danielsen EH, Brooks DJ, Borghammer P. Reduced Synaptic Density in Patients with Lewy Body Dementia: An [ 11 C]UCB-J PET Imaging Study. Mov Disord 2021; 36:2057-2065. [PMID: 33899255 DOI: 10.1002/mds.28617] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 03/23/2021] [Accepted: 03/24/2021] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND Patients with Parkinson's disease (PD) often develop dementia, but the underlying substrate is incompletely understood. Generalized synaptic degeneration may contribute to dysfunction and cognitive decline in Lewy body dementias, but in vivo evidence is lacking. OBJECTIVE The objective of this study was to assess the density of synapses in non-demented PD (nPD) subjects (N = 21), patients with PD-dementia or Dementia with Lewy bodies (DLB) (N = 13), and age-matched healthy controls (N = 15). METHOD Using in vivo PET imaging and the novel synaptic-vesicle-glycoprotein 2A (SV2A) radioligand [11C]UCB-J, SUVR-1 values were obtained for 12 pre-defined regions. Volumes-of-interest were defined on MRI T1 scans. Voxel-level between-group comparisons of [11C]UCB-J SUVR-1 were performed. All subjects underwent neuropsychological assessment. Correlations between [11C]UCB- J PET and domain-specific cognitive functioning were examined. RESULTS nPD patients only demonstrated significantly reduced SUVR-1 values in the substantia nigra (SN) compared to HC. DLB/PDD patients demonstrated reduced SUVR-1 values in SN and all cortical VOIs except for the hippocampus and amygdala. The voxel-based analysis supported the VOI results. Significant correlation was seen between middle frontal gyrus [11C]UCB-J SUVR-1 and performance on tests of executive function. CONCLUSION Widespread cortical reduction of synaptic density was documented in a cohort of DLB/PDD subjects using in vivo [11C]UCB-J PET. Our study confirms previously reported synaptic loss in SN of nPD patients. [11C]UCB-J binding in selected cortical VOIs of the DLB/PDD patients correlated with their levels of cognitive function across relevant neuropsychological domains. These findings suggest that the loss of synaptic density contributes to cognitive impairment in nPD and DLB/PDD. © 2021 International Parkinson and Movement Disorder Society.
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Affiliation(s)
- Katrine B Andersen
- Department of Nuclear Medicine and PET, Aarhus University Hospital, Aarhus, Denmark
| | - Allan K Hansen
- Department of Nuclear Medicine and PET, Aarhus University Hospital, Aarhus, Denmark
| | - Malene F Damholdt
- Department of Psychology and Behavioural Science, Aarhus University, Aarhus, Denmark
| | - Jacob Horsager
- Department of Nuclear Medicine and PET, Aarhus University Hospital, Aarhus, Denmark
| | - Casper Skjaerbaek
- Department of Nuclear Medicine and PET, Aarhus University Hospital, Aarhus, Denmark
| | - Hanne Gottrup
- Department of Neurology, Aarhus University Hospital, Aarhus, Denmark
| | - Henriette Klit
- Department of Neurology, Aarhus University Hospital, Aarhus, Denmark
| | | | - Erik H Danielsen
- Department of Neurology, Aarhus University Hospital, Aarhus, Denmark
| | - David J Brooks
- Department of Nuclear Medicine and PET, Aarhus University Hospital, Aarhus, Denmark.,Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, UK.,Department of Brain Sciences, Imperial College London, London, UK
| | - Per Borghammer
- Department of Nuclear Medicine and PET, Aarhus University Hospital, Aarhus, Denmark
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Cawthorne C, Maguire P, Mercier J, Sciberras D, Serdons K, Bormans G, de Hoon J, Van Laere K, Koole M. Human biodistribution and dosimetry of [ 11C]-UCB-J, a PET radiotracer for imaging synaptic density. EJNMMI Phys 2021; 8:37. [PMID: 33891195 PMCID: PMC8065069 DOI: 10.1186/s40658-021-00384-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Accepted: 04/13/2021] [Indexed: 11/10/2022] Open
Abstract
RATIONALE [11C]-UCB-J is an emerging tool for the noninvasive measurement of synaptic vesicle density in vivo. Here, we report human biodistribution and dosimetry estimates derived from sequential whole-body PET using two versions of the OLINDA dosimetry program. METHODS Sequential whole-body PET scans were performed in 3 healthy subjects for 2 h after injection of 254 ± 77 MBq [11C]-UCB-J. Volumes of interest were drawn over relevant source organs to generate time-activity curves and calculate time-integrated activity coefficients, with effective dose coefficients calculated using OLINDA 2.1 and compared to values derived from OLINDA 1.1 and those recently reported in the literature. RESULTS [11C]-UCB-J administration was safe and showed mixed renal and hepatobiliary clearance, with largest organ absorbed dose coefficients for the urinary bladder wall and small intestine (21.7 and 23.5 μGy/MBq, respectively). The average (±SD) effective dose coefficient was 5.4 ± 0.7 and 5.1 ± 0.8 μSv/MBq for OLINDA versions 1.1 and 2.1 respectively. Doses were lower than previously reported in the literature using either software version. CONCLUSIONS A single IV administration of 370 MBq [11C]-UCB-J corresponds to an effective dose of less than 2.0 mSv, enabling multiple PET examinations to be carried out in the same subject. TRIAL REGISTRATION EudraCT number: 2016-001190-32. Registered 16 March 2016, no URL available for phase 1 trials.
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Affiliation(s)
- Christopher Cawthorne
- Nuclear Medicine and Molecular Imaging, Department of Imaging and Pathology, KU Leuven, Leuven, Belgium
| | | | | | | | - Kim Serdons
- Division of Nuclear Medicine, University Hospitals Leuven, Leuven, Belgium
| | - Guy Bormans
- Laboratory for Radiopharmaceutical Research, KU Leuven, Leuven, Belgium
| | - Jan de Hoon
- Center for Clinical Pharmacology, University Hospitals Leuven, Leuven, Belgium
| | - Koen Van Laere
- Nuclear Medicine and Molecular Imaging, Department of Imaging and Pathology, KU Leuven, Leuven, Belgium.,Division of Nuclear Medicine, University Hospitals Leuven, Leuven, Belgium
| | - Michel Koole
- Nuclear Medicine and Molecular Imaging, Department of Imaging and Pathology, KU Leuven, Leuven, Belgium.
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