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Kouli A, Spindler LRB, Fryer TD, Hong YT, Malpetti M, Aigbirhio FI, White SR, Camacho M, O’Brien JT, Williams-Gray CH. Neuroinflammation is linked to dementia risk in Parkinson's disease. Brain 2024; 147:923-935. [PMID: 37757857 PMCID: PMC10907093 DOI: 10.1093/brain/awad322] [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: 04/20/2023] [Revised: 08/09/2023] [Accepted: 09/07/2023] [Indexed: 09/29/2023] Open
Abstract
The development of dementia is a devastating aspect of Parkinson's disease (PD), affecting nearly half of patients within 10 years post-diagnosis. For effective therapies to prevent and slow progression to PD dementia (PDD), the key mechanisms that determine why some people with PD develop early dementia, while others remain cognitively unaffected, need to be understood. Neuroinflammation and tau protein accumulation have been demonstrated in post-mortem PD brains, and in many other neurodegenerative disorders leading to dementia. However, whether these processes mediate dementia risk early on in the PD disease course is not established. To this end, we used PET neuroimaging with 11C-PK11195 to index neuroinflammation and 18F-AV-1451 for misfolded tau in early PD patients, stratified according to dementia risk in our 'Neuroinflammation and Tau Accumulation in Parkinson's Disease Dementia' (NET-PDD) study. The NET-PDD study longitudinally assesses newly-diagnosed PD patients in two subgroups at low and high dementia risk (stratified based on pentagon copying, semantic fluency, MAPT genotype), with comparison to age- and sex-matched controls. Non-displaceable binding potential (BPND) in 43 brain regions (Hammers' parcellation) was compared between groups (pairwise t-tests), and associations between BPND of the tracers tested (linear-mixed-effect models). We hypothesized that people with higher dementia risk have greater inflammation and/or tau accumulation in advance of significant cognitive decline. We found significantly elevated neuroinflammation (11C-PK11195 BPND) in multiple subcortical and restricted cortical regions in the high dementia risk group compared with controls, while in the low-risk group this was limited to two cortical areas. The high dementia risk group also showed significantly greater neuroinflammation than the low-risk group concentrated on subcortical and basal ganglia regions. Neuroinflammation in most of these regions was associated with worse cognitive performance (Addenbrooke's Cognitive Examination-III score). Overall neuroinflammation burden also correlated with serum levels of pro-inflammatory cytokines. In contrast, increases in 18F-AV-1451 (tau) BPND in PD versus controls were restricted to subcortical regions where off-target binding is typically seen, with no relationship to cognition found. Whole-brain 18F-AV-1451 burden correlated with serum phosphorylated tau181 levels. Although there was minimal regional tau accumulation in PD, regional neuroinflammation and tau burden correlated in PD participants, with the strongest association in the high dementia risk group, suggesting possible co-localization of these pathologies. In conclusion, our findings suggest that significant regional neuroinflammation in early PD might underpin higher risk for PDD development, indicating neuroinflammation as a putative early modifiable aetiopathological disease factor to prevent or slow dementia development using immunomodulatory strategies.
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Affiliation(s)
- Antonina Kouli
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, CB2 0PY, UK
| | - Lennart R B Spindler
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, CB2 0PY, UK
| | - Tim D Fryer
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, CB2 0PY, UK
- Wolfson Brain Imaging Centre, University of Cambridge, Cambridge, CB2 0QQ, UK
| | - Young T Hong
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, CB2 0PY, UK
- Wolfson Brain Imaging Centre, University of Cambridge, Cambridge, CB2 0QQ, UK
| | - Maura Malpetti
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, CB2 0PY, UK
| | - Franklin I Aigbirhio
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, CB2 0PY, UK
- Wolfson Brain Imaging Centre, University of Cambridge, Cambridge, CB2 0QQ, UK
| | - Simon R White
- Medical Research Council Biostatistics Unit, Cambridge Institute of Public Health, Cambridge, CB2 0SL, UK
| | - Marta Camacho
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, CB2 0PY, UK
| | - John T O’Brien
- Department of Psychiatry, University of Cambridge, Cambridge, CB2 0SZ, UK
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Chisholm TS, Hunter CA. A closer look at amyloid ligands, and what they tell us about protein aggregates. Chem Soc Rev 2024; 53:1354-1374. [PMID: 38116736 DOI: 10.1039/d3cs00518f] [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: 12/21/2023]
Abstract
The accumulation of amyloid fibrils is characteristic of neurodegenerative diseases such as Alzheimer's disease (AD) and Parkinson's disease. Detecting these fibrils with fluorescent or radiolabelled ligands is one strategy for diagnosing and better understanding these diseases. A vast number of amyloid-binding ligands have been reported in the literature as a result. To obtain a better understanding of how amyloid ligands bind, we have compiled a database of 3457 experimental dissociation constants for 2076 unique amyloid-binding ligands. These ligands target Aβ, tau, or αSyn fibrils, as well as relevant biological samples including AD brain homogenates. From this database significant variation in the reported dissociation constants of ligands was found, possibly due to differences in the morphology of the fibrils being studied. Ligands were also found to bind to Aβ(1-40) and Aβ(1-42) fibrils with similar affinities, whereas a greater difference was found for binding to Aβ and tau or αSyn fibrils. Next, the binding of ligands to fibrils was shown to be largely limited by the hydrophobic effect. Some Aβ ligands do not fit into this hydrophobicity-limited model, suggesting that polar interactions can play an important role when binding to this target. Finally several binding site models were outlined for amyloid fibrils that describe what ligands target what binding sites. These models provide a foundation for interpreting and designing site-specific binding assays.
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Affiliation(s)
- Timothy S Chisholm
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1 EW, UK.
| | - Christopher A Hunter
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1 EW, UK.
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Bisi N, Pinzi L, Rastelli G, Tonali N. Early Diagnosis of Neurodegenerative Diseases: What Has Been Undertaken to Promote the Transition from PET to Fluorescence Tracers. Molecules 2024; 29:722. [PMID: 38338465 PMCID: PMC10856728 DOI: 10.3390/molecules29030722] [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: 01/04/2024] [Revised: 01/29/2024] [Accepted: 01/30/2024] [Indexed: 02/12/2024] Open
Abstract
Alzheimer's Disease (AD) and Parkinson's Disease (PD) represent two among the most frequent neurodegenerative diseases worldwide. A common hallmark of these pathologies is the misfolding and consequent aggregation of amyloid proteins into soluble oligomers and insoluble β-sheet-rich fibrils, which ultimately lead to neurotoxicity and cell death. After a hundred years of research on the subject, this is the only reliable histopathological feature in our hands. Since AD and PD are diagnosed only once neuronal death and the first symptoms have appeared, the early detection of these diseases is currently impossible. At present, there is no effective drug available, and patients are left with symptomatic and inconclusive therapies. Several reasons could be associated with the lack of effective therapeutic treatments. One of the most important factors is the lack of selective probes capable of detecting, as early as possible, the most toxic amyloid species involved in the onset of these pathologies. In this regard, chemical probes able to detect and distinguish among different amyloid aggregates are urgently needed. In this article, we will review and put into perspective results from ex vivo and in vivo studies performed on compounds specifically interacting with such early species. Following a general overview on the three different amyloid proteins leading to insoluble β-sheet-rich amyloid deposits (amyloid β1-42 peptide, Tau, and α-synuclein), a list of the advantages and disadvantages of the approaches employed to date is discussed, with particular attention paid to the translation of fluorescence imaging into clinical applications. Furthermore, we also discuss how the progress achieved in detecting the amyloids of one neurodegenerative disease could be leveraged for research into another amyloidosis. As evidenced by a critical analysis of the state of the art, substantial work still needs to be conducted. Indeed, the early diagnosis of neurodegenerative diseases is a priority, and we believe that this review could be a useful tool for better investigating this field.
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Affiliation(s)
- Nicolò Bisi
- Université Paris-Saclay, CNRS, BioCIS, Bat. Henri Moissan, 17, Av. des Sciences, 91400 Orsay, France
| | - Luca Pinzi
- Department of Life Sciences, University of Modena and Reggio Emilia, Via Giuseppe Campi 103, 41125 Modena, Italy; (L.P.); (G.R.)
| | - Giulio Rastelli
- Department of Life Sciences, University of Modena and Reggio Emilia, Via Giuseppe Campi 103, 41125 Modena, Italy; (L.P.); (G.R.)
| | - Nicolò Tonali
- Université Paris-Saclay, CNRS, BioCIS, Bat. Henri Moissan, 17, Av. des Sciences, 91400 Orsay, France
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Satoh R, Ali F, Botha H, Lowe VJ, Josephs KA, Whitwell JL. Direct comparison between 18F-Flortaucipir tau PET and quantitative susceptibility mapping in progressive supranuclear palsy. Neuroimage 2024; 286:120509. [PMID: 38184157 PMCID: PMC10868646 DOI: 10.1016/j.neuroimage.2024.120509] [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: 09/11/2023] [Revised: 12/22/2023] [Accepted: 01/03/2024] [Indexed: 01/08/2024] Open
Abstract
PURPOSE The pattern of flortaucipir tau PET uptake is topographically similar to the pattern of magnetic susceptibility in progressive supranuclear palsy (PSP); both with increased signal in subcortical structures such as the basal ganglia and midbrain, suggesting that they may be closely related. However, their relationship remains unknown since no studies have directly compared these two modalities in the same PSP cohort. We hypothesized that some flortaucipir uptake in PSP is associated with magnetic susceptibility, and hence iron deposition. The aim of this study was to evaluate the regional relationship between flortaucipir uptake and magnetic susceptibility and to examine the effects of susceptibility on flortaucipir uptake in PSP. METHODS Fifty PSP patients and 67 cognitively normal controls were prospectively recruited and underwent three Tesla MRI and flortaucipir tau PET scans. Quantitative susceptibility maps were reconstructed from multi-echo gradient-echo MRI images. Region of interest (ROI) analysis was performed to obtain flortaucipir and susceptibility values in the subcortical regions. Relationships between flortaucipir and susceptibility signals were evaluated using partial correlation analysis in the subcortical ROIs and voxel-based analysis in the whole brain. The effects of susceptibility on flortaucipir uptake were examined by using the framework of mediation analysis. RESULTS Both flortaucipir and susceptibility were greater in PSP compared to controls in the putamen, pallidum, subthalamic nucleus, red nucleus, and cerebellar dentate (p<0.05). The ROI-based and voxel-based analyses showed that these two signals were positively correlated in these five regions (r = 0.36-0.59, p<0.05). Mediation analysis showed that greater flortaucipir uptake was partially explained by susceptibility in the putamen, pallidum, subthalamic nucleus, and red nucleus, and fully explained in the cerebellar dentate. CONCLUSIONS These results suggest that some of the flortaucipir uptake in subcortical regions in PSP is related to iron deposition. These findings will contribute to our understanding of the mechanisms underlying flortaucipir tau PET findings in PSP and other neurodegenerative diseases.
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Affiliation(s)
- Ryota Satoh
- Department of Neurology, Mayo Clinic, Rochester, MN, USA
| | - Farwa Ali
- Department of Neurology, Mayo Clinic, Rochester, MN, USA
| | - Hugo Botha
- Department of Neurology, Mayo Clinic, Rochester, MN, USA
| | - Val J Lowe
- Department of Radiology, Mayo Clinic, 200 1st St SW, 55905, Rochester, MN, USA
| | | | - Jennifer L Whitwell
- Department of Radiology, Mayo Clinic, 200 1st St SW, 55905, Rochester, MN, USA.
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Aguero C, Dhaynaut M, Amaral AC, Moon SH, Neelamegam R, Scapellato M, Carazo-Casas C, Kumar S, El Fakhri G, Johnson K, Frosch MP, Normandin MD, Gómez-Isla T. Head-to-head comparison of [ 18F]-Flortaucipir, [ 18F]-MK-6240 and [ 18F]-PI-2620 postmortem binding across the spectrum of neurodegenerative diseases. Acta Neuropathol 2024; 147:25. [PMID: 38280071 PMCID: PMC10822013 DOI: 10.1007/s00401-023-02672-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Revised: 12/19/2023] [Accepted: 12/19/2023] [Indexed: 01/29/2024]
Abstract
We and others have shown that [18F]-Flortaucipir, the most validated tau PET tracer thus far, binds with strong affinity to tau aggregates in Alzheimer's (AD) but has relatively low affinity for tau aggregates in non-AD tauopathies and exhibits off-target binding to neuromelanin- and melanin-containing cells, and to hemorrhages. Several second-generation tau tracers have been subsequently developed. [18F]-MK-6240 and [18F]-PI-2620 are the two that have garnered most attention. Our recent data indicated that the binding pattern of [18F]-MK-6240 closely parallels that of [18F]-Flortaucipir. The present study aimed at the direct comparison of the autoradiographic binding properties and off-target profile of [18F]-Flortaucipir, [18F]-MK-6240 and [18F]-PI-2620 in human tissue specimens, and their potential binding to monoamine oxidases (MAO). Phosphor-screen and high resolution autoradiographic patterns of the three tracers were studied in the same postmortem tissue material from AD and non-AD tauopathies, cerebral amyloid angiopathy, synucleopathies, transactive response DNA-binding protein 43 (TDP-43)-frontotemporal lobe degeneration and controls. Our results show that the three tracers show nearly identical autoradiographic binding profiles. They all strongly bind to neurofibrillary tangles in AD but do not seem to bind to a significant extent to tau aggregates in non-AD tauopathies pointing to their limited utility for the in vivo detection of non-AD tau lesions. None of them binds to lesions containing β-amyloid, α-synuclein or TDP-43 but they all show strong off-target binding to neuromelanin and melanin-containing cells, as well as weaker binding to areas of hemorrhage. The autoradiographic binding signals of the three tracers are only weakly displaced by competing concentrations of selective MAO-B inhibitor deprenyl but not by MAO-A inhibitor clorgyline suggesting that MAO enzymes do not appear to be a significant binding target of any of them. These findings provide relevant insights for the correct interpretation of the in vivo behavior of these three tau PET tracers.
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Affiliation(s)
- Cinthya Aguero
- MassGeneral Institute for NeuroDegenerative Disease, Charlestown, MA, USA
- Department of Neurology, Massachusetts General Hospital, WACC Suite 715, 15th Parkman St., Boston, MA, 02114, USA
| | - Maeva Dhaynaut
- Gordon Center for Medical Imaging, Department of Radiology, Massachusetts General Hospital, Boston, MA, USA
| | - Ana C Amaral
- MassGeneral Institute for NeuroDegenerative Disease, Charlestown, MA, USA
- Department of Neurology, Massachusetts General Hospital, WACC Suite 715, 15th Parkman St., Boston, MA, 02114, USA
| | - S-H Moon
- Gordon Center for Medical Imaging, Department of Radiology, Massachusetts General Hospital, Boston, MA, USA
| | - Ramesh Neelamegam
- Gordon Center for Medical Imaging, Department of Radiology, Massachusetts General Hospital, Boston, MA, USA
| | - Margaret Scapellato
- MassGeneral Institute for NeuroDegenerative Disease, Charlestown, MA, USA
- Department of Neurology, Massachusetts General Hospital, WACC Suite 715, 15th Parkman St., Boston, MA, 02114, USA
| | - Carlos Carazo-Casas
- MassGeneral Institute for NeuroDegenerative Disease, Charlestown, MA, USA
- Department of Neurology, Massachusetts General Hospital, WACC Suite 715, 15th Parkman St., Boston, MA, 02114, USA
| | - Sunny Kumar
- MassGeneral Institute for NeuroDegenerative Disease, Charlestown, MA, USA
- Department of Neurology, Massachusetts General Hospital, WACC Suite 715, 15th Parkman St., Boston, MA, 02114, USA
| | - Georges El Fakhri
- Gordon Center for Medical Imaging, Department of Radiology, Massachusetts General Hospital, Boston, MA, USA
| | - Keith Johnson
- Department of Neurology, Massachusetts General Hospital, WACC Suite 715, 15th Parkman St., Boston, MA, 02114, USA
- Gordon Center for Medical Imaging, Department of Radiology, Massachusetts General Hospital, Boston, MA, USA
| | - Matthew P Frosch
- MassGeneral Institute for NeuroDegenerative Disease, Charlestown, MA, USA
- Department of Neurology, Massachusetts General Hospital, WACC Suite 715, 15th Parkman St., Boston, MA, 02114, USA
- C.S. Kubik Laboratory for Neuropathology, Massachusetts General Hospital, Boston, MA, USA
| | - Marc D Normandin
- Gordon Center for Medical Imaging, Department of Radiology, Massachusetts General Hospital, Boston, MA, USA
| | - Teresa Gómez-Isla
- MassGeneral Institute for NeuroDegenerative Disease, Charlestown, MA, USA.
- Department of Neurology, Massachusetts General Hospital, WACC Suite 715, 15th Parkman St., Boston, MA, 02114, USA.
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6
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Burnham SC, Iaccarino L, Pontecorvo MJ, Fleisher AS, Lu M, Collins EC, Devous MD. A review of the flortaucipir literature for positron emission tomography imaging of tau neurofibrillary tangles. Brain Commun 2023; 6:fcad305. [PMID: 38187878 PMCID: PMC10768888 DOI: 10.1093/braincomms/fcad305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Revised: 09/13/2023] [Accepted: 11/14/2023] [Indexed: 01/09/2024] Open
Abstract
Alzheimer's disease is defined by the presence of β-amyloid plaques and neurofibrillary tau tangles potentially preceding clinical symptoms by many years. Previously only detectable post-mortem, these pathological hallmarks are now identifiable using biomarkers, permitting an in vivo definitive diagnosis of Alzheimer's disease. 18F-flortaucipir (previously known as 18F-T807; 18F-AV-1451) was the first tau positron emission tomography tracer to be introduced and is the only Food and Drug Administration-approved tau positron emission tomography tracer (Tauvid™). It has been widely adopted and validated in a number of independent research and clinical settings. In this review, we present an overview of the published literature on flortaucipir for positron emission tomography imaging of neurofibrillary tau tangles. We considered all accessible peer-reviewed literature pertaining to flortaucipir through 30 April 2022. We found 474 relevant peer-reviewed publications, which were organized into the following categories based on their primary focus: typical Alzheimer's disease, mild cognitive impairment and pre-symptomatic populations; atypical Alzheimer's disease; non-Alzheimer's disease neurodegenerative conditions; head-to-head comparisons with other Tau positron emission tomography tracers; and technical considerations. The available flortaucipir literature provides substantial evidence for the use of this positron emission tomography tracer in assessing neurofibrillary tau tangles in Alzheimer's disease and limited support for its use in other neurodegenerative disorders. Visual interpretation and quantitation approaches, although heterogeneous, mostly converge and demonstrate the high diagnostic and prognostic value of flortaucipir in Alzheimer's disease.
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Affiliation(s)
| | | | | | | | - Ming Lu
- Avid, Eli Lilly and Company, Philadelphia, PA 19104, USA
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Wu N, Zhang L, Zhang X, Zhang Q, Liu J, Li Y, Yan XX, Liang Y, Zhang J, Cui M. Synthesis and Bioevaluation of 2-Styrylquinoxaline Derivatives as Tau-PET Tracers. Mol Pharm 2023; 20:5865-5876. [PMID: 37852240 DOI: 10.1021/acs.molpharmaceut.3c00717] [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] [Indexed: 10/20/2023]
Abstract
This study focused on designing and evaluating Tau-PET tracers for noninvasive positron emission computed tomography (PET) imaging of neurofibrillary tangles (NFTs), a hallmark pathology of Alzheimer's disease (AD). The tracers were synthesized with a 2-styrylquinoxaline scaffold and varying lengths of FPEG chains. The compound [18F]15, which had two ethoxy units, showed high affinity for recombinant K18-Tau aggregates (Ki = 41.48 nM) and the highest selectivity versus Aβ1-42 aggregates (8.83-fold). In vitro autoradiography and fluorescent staining profiles further validated the binding of [18F]15 or 15 toward NFTs in brain sections from AD patients and Tau-transgenic mice. In normal ICR mice, [18F]15 exhibited an ideal initial brain uptake (11.21% ID/g at 2 min) and moderate washout ratio (2.29), and micro-PET studies in rats confirmed its ability to penetrate the blood-brain barrier with the peak SUV value of 1.94 in the cortex. These results suggest that [18F]15 has the potential to be developed into a useful Tau-PET tracer for early AD diagnosis and evaluation of anti-Tau therapeutics.
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Affiliation(s)
- Nan Wu
- Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, China
| | - Longfei Zhang
- Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, China
| | - Xiaojun Zhang
- Department of Nuclear Medicine, Chinese PLA General Hospital, Beijing 100853, China
| | - Qilei Zhang
- Department of Anatomy and Neurobiology, Xiangya School of Medicine, Central South University, Changsha 410013, China
| | - Jiaqi Liu
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Taikang Center for Life and Medical Science, Hubei Key Laboratory of Cell Homeostasis, Wuhan University, Wuhan 430072, China
| | - Yuying Li
- Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, China
| | - Xiao-Xin Yan
- Department of Anatomy and Neurobiology, Xiangya School of Medicine, Central South University, Changsha 410013, China
| | - Yi Liang
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Taikang Center for Life and Medical Science, Hubei Key Laboratory of Cell Homeostasis, Wuhan University, Wuhan 430072, China
| | - Jinming Zhang
- Department of Nuclear Medicine, Chinese PLA General Hospital, Beijing 100853, China
| | - Mengchao Cui
- Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, China
- Center for Advanced Materials Research, Beijing Normal University, Zhuhai 519087, China
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8
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Bollack A, Pemberton HG, Collij LE, Markiewicz P, Cash DM, Farrar G, Barkhof F. Longitudinal amyloid and tau PET imaging in Alzheimer's disease: A systematic review of methodologies and factors affecting quantification. Alzheimers Dement 2023; 19:5232-5252. [PMID: 37303269 DOI: 10.1002/alz.13158] [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: 12/21/2022] [Revised: 04/21/2023] [Accepted: 04/25/2023] [Indexed: 06/13/2023]
Abstract
Deposition of amyloid and tau pathology can be quantified in vivo using positron emission tomography (PET). Accurate longitudinal measurements of accumulation from these images are critical for characterizing the start and spread of the disease. However, these measurements are challenging; precision and accuracy can be affected substantially by various sources of errors and variability. This review, supported by a systematic search of the literature, summarizes the current design and methodologies of longitudinal PET studies. Intrinsic, biological causes of variability of the Alzheimer's disease (AD) protein load over time are then detailed. Technical factors contributing to longitudinal PET measurement uncertainty are highlighted, followed by suggestions for mitigating these factors, including possible techniques that leverage shared information between serial scans. Controlling for intrinsic variability and reducing measurement uncertainty in longitudinal PET pipelines will provide more accurate and precise markers of disease evolution, improve clinical trial design, and aid therapy response monitoring.
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Affiliation(s)
- Ariane Bollack
- Department of Medical Physics and Biomedical Engineering, Centre for Medical Image Computing (CMIC), University College London, London, UK
| | - Hugh G Pemberton
- Department of Medical Physics and Biomedical Engineering, Centre for Medical Image Computing (CMIC), University College London, London, UK
- GE Healthcare, Amersham, UK
- UCL Queen Square Institute of Neurology, London, UK
| | - Lyduine E Collij
- Department of Radiology and Nuclear Medicine, Amsterdam UMC, location VUmc, Amsterdam, The Netherlands
- Clinical Memory Research Unit, Department of Clinical Sciences, Lund University, Malmö, Sweden
| | - Pawel Markiewicz
- Department of Medical Physics and Biomedical Engineering, Centre for Medical Image Computing (CMIC), University College London, London, UK
| | - David M Cash
- UCL Queen Square Institute of Neurology, London, UK
- UK Dementia Research Institute at University College London, London, UK
| | | | - Frederik Barkhof
- Department of Medical Physics and Biomedical Engineering, Centre for Medical Image Computing (CMIC), University College London, London, UK
- UCL Queen Square Institute of Neurology, London, UK
- Department of Radiology and Nuclear Medicine, Amsterdam UMC, location VUmc, Amsterdam, The Netherlands
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9
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Tuncel H, Visser D, Timmers T, Wolters EE, Ossenkoppele R, van der Flier WM, van Berckel BNM, Boellaard R, Golla SSV. Head-to-head comparison of relative cerebral blood flow derived from dynamic [ 18F]florbetapir and [ 18F]flortaucipir PET in subjects with subjective cognitive decline. EJNMMI Res 2023; 13:93. [PMID: 37889456 PMCID: PMC10611685 DOI: 10.1186/s13550-023-01041-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Accepted: 10/11/2023] [Indexed: 10/28/2023] Open
Abstract
BACKGROUND Dynamic PET imaging studies provide accurate estimates of specific binding, but also measure the relative tracer delivery (R1), which is a proxy for relative cerebral blood flow (rCBF). Recently, studies suggested that R1 obtained from different tracers could be used interchangeably and is irrespective of target tissue. However, the similarities or differences of R1 obtained from different PET tracers still require validation. Therefore, the goal of the current study was to compare R1 estimates, derived from dynamic [18F]florbetapir (amyloid) and [18F]flortaucipir (tau) PET, in the same subjects with subjective cognitive decline (SCD). RESULTS Voxel-wise analysis presented a small cluster (1.6% of the whole brain) with higher R1 values for [18F]flortaucipir compared to [18F]florbetapir in the Aβ-negative group. These voxels were part of the hippocampus and the left middle occipital gyrus. In part of the thalamus, midbrain and cerebellum, voxels (2.5% of the whole brain) with higher R1 values for [18F]florbetapir were observed. In the Aβ-positive group, a cluster (0.2% of the whole brain) of higher R1 values was observed in part of the hippocampus, right parahippocampal gyrus and in the left sagittal stratum for [18F]flortaucipir compared to [18F]florbetapir. Furthermore, in part of the thalamus, left amygdala, midbrain and right parahippocampal gyrus voxels (0.4% of the whole brain) with higher R1 values for [18F]florbetapir were observed. Despite these differences, [18F]florbetapir R1 had high correspondence with [18F]flortaucipir R1 across all regions of interest (ROIs) and subjects (Aβ-:r2 = 0.79, slope = 0.85, ICC = 0.76; Aβ+: r2 = 0.87, slope = 0.93, ICC = 0.77). CONCLUSION [18F]flortaucipir and [18F]florbetapir showed similar R1 estimates in cortical regions. This finding, put together with previous studies, indicates that R1 could be considered a surrogate for relative cerebral blood flow (rCBF) in the cortex and may be used interchangeably, but with caution, regardless of the choice of these two tracers.
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Affiliation(s)
- Hayel Tuncel
- Department of Radiology and Nuclear Medicine, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam UMC, De Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands
| | - Denise Visser
- Department of Radiology and Nuclear Medicine, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam UMC, De Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands
| | - Tessa Timmers
- Department of Radiology and Nuclear Medicine, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam UMC, De Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands
- Department of Neurology, Alzheimer Center Amsterdam, Vrije Universiteit Amsterdam, Amsterdam UMC, Amsterdam, The Netherlands
| | - Emma E Wolters
- Department of Radiology and Nuclear Medicine, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam UMC, De Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands
- Department of Neurology, Alzheimer Center Amsterdam, Vrije Universiteit Amsterdam, Amsterdam UMC, Amsterdam, The Netherlands
| | - Rik Ossenkoppele
- Department of Neurology, Alzheimer Center Amsterdam, Vrije Universiteit Amsterdam, Amsterdam UMC, Amsterdam, The Netherlands
- Clinical Memory Research Unit, Lund University, Lund, Sweden
| | - Wiesje M van der Flier
- Department of Neurology, Alzheimer Center Amsterdam, Vrije Universiteit Amsterdam, Amsterdam UMC, Amsterdam, The Netherlands
- Department of Epidemiology and Biostatistics, Vrije Universiteit Amsterdam, Amsterdam UMC, Amsterdam, The Netherlands
| | - Bart N M van Berckel
- Department of Radiology and Nuclear Medicine, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam UMC, De Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands
| | - Ronald Boellaard
- Department of Radiology and Nuclear Medicine, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam UMC, De Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands
| | - Sandeep S V Golla
- Department of Radiology and Nuclear Medicine, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam UMC, De Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands.
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10
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Matsuda H, Yamao T. Tau positron emission tomography in patients with cognitive impairment and suspected Alzheimer's disease. Fukushima J Med Sci 2023; 69:85-93. [PMID: 37302841 PMCID: PMC10480511 DOI: 10.5387/fms.2023-08] [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: 03/17/2023] [Accepted: 05/10/2023] [Indexed: 06/13/2023] Open
Abstract
Alzheimer's disease (AD) is diagnosed by the presence of both amyloid β and tau proteins. Recent advances in molecular PET imaging have made it possible to assess the accumulation of these proteins in the living brain. PET ligands have been developed that bind to 3R/4R tau in AD, but not to 3R tau or 4R tau alone. Of the first-generation PET ligands, 18F-flortaucipir has recently been approved by the Food and Drug Administration. Several second-generation PET probes with less off-target binding have been developed and are being applied clinically. Visual interpretation of tau PET should be based on neuropathological neurofibrillary tangle staging instead of a simple positive or negative classification. Four visual read classifications have been proposed: "no uptake," "medial temporal lobe (MTL) only," "MTL AND," and "outside MTL." As an adjunct to visual interpretation, quantitative analysis has been proposed using MRI-based native space FreeSurfer parcellations. The standardized uptake value ratio of the target area is measured using the cerebellar gray matter as a reference region. In the near future, the Centiloid scale of tau PET is expected to be used as a harmonized value for standardizing each analytical method or PET ligand used, similar to amyloid PET.
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Affiliation(s)
- Hiroshi Matsuda
- Department of Biofunctional Imaging, Fukushima Medical University
| | - Tensho Yamao
- Department of Radiological Sciences, School of Health Sciences, Fukushima Medical University
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11
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Björk L, Klingstedt T, Nilsson KPR. Thiophene-Based Ligands: Design, Synthesis and Their Utilization for Optical Assignment of Polymorphic-Disease-Associated Protein Aggregates. Chembiochem 2023; 24:e202300044. [PMID: 36891883 PMCID: PMC10404026 DOI: 10.1002/cbic.202300044] [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: 01/20/2023] [Revised: 03/03/2023] [Accepted: 03/08/2023] [Indexed: 03/10/2023]
Abstract
The development of ligands for detecting protein aggregates is of great interest, as these aggregated proteinaceous species are the pathological hallmarks of several devastating diseases, including Alzheimer's disease. In this regard, thiophene-based ligands have emerged as powerful tools for fluorescent assessment of these pathological entities. The intrinsic conformationally sensitive photophysical properties of poly- and oligothiophenes have allowed optical assignment of disease-associated protein aggregates in tissue sections, as well as real-time in vivo imaging of protein deposits. Herein, we recount the chemical evolution of different generations of thiophene-based ligands, and exemplify their use for the optical distinction of polymorphic protein aggregates. Furthermore, the chemical determinants for achieving a superior fluorescent thiophene-based ligand, as well as the next generation of thiophene-based ligands targeting distinct aggregated species are described. Finally, the directions for future research into the chemical design of thiophene-based ligands that can aid in resolving the scientific challenges around protein aggregation diseases are discussed.
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Affiliation(s)
- Linnea Björk
- Department of Physics, Chemistry and Biology, Linköping University, 581 83, Linköping, Sweden
| | - Therése Klingstedt
- Department of Physics, Chemistry and Biology, Linköping University, 581 83, Linköping, Sweden
| | - K Peter R Nilsson
- Department of Physics, Chemistry and Biology, Linköping University, 581 83, Linköping, Sweden
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12
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Miyamoto M, Okuyama C, Kagawa S, Kusano K, Takahashi M, Takahata K, Jang MK, Yamauchi H. Radiation dosimetry and pharmacokinetics of the tau PET tracer florzolotau (18F) in healthy Japanese subjects. Ann Nucl Med 2023; 37:300-309. [PMID: 36890399 PMCID: PMC10129982 DOI: 10.1007/s12149-023-01828-x] [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: 11/25/2022] [Accepted: 02/14/2023] [Indexed: 03/10/2023]
Abstract
OBJECTIVE Abnormal aggregation of tau in the brain is a major contributing factor in various neurodegenerative diseases. Florzolotau (18F) (florzolotau, APN-1607, PM-PBB3) has been shown to be a probe for tau fibrils in an animal model and patients with Alzheimer's disease and those with non-Alzheimer's disease tauopathies. The objective of this study is to evaluate the safety, pharmacokinetics, and radiation dose following a single intravenous administration of florzolotau in healthy Japanese subjects. METHODS Three healthy male Japanese subjects aged between 20 and 64 were enrolled in this study. Subjects were determined to be eligible based on the screening assessments at the study site. Subjects received a single intravenous dose of 195.0 ± 0.5 MBq of florzolotau and underwent the whole-body PET scan 10 times in total to calculate absorbed doses to major organs/tissues and effective dose. Radioactivities in whole blood and urine were also measured for pharmacokinetic evaluation. Absorbed doses to major organs/tissues and effective dose were estimated using the medical internal radiation dose (MIRD) method. Vital signs, electrocardiography (ECG), and blood tests were done for safety evaluation. RESULTS The intravenous injection of florzolotau was well tolerated. There were no adverse events or clinically detectable pharmacologic effects related to the tracer in any subjects. No significant changes in vital signs and ECG were observed. The highest mean initial uptake at 15 min after injection was in the liver (29.0 ± 4.0%ID), intestine (4.69 ± 1.65%ID), and brain (2.13 ± 0.18%ID). The highest absorbed dose was 508 μGy/MBq of the gallbladder wall, followed by the liver of 79.4 μGy/MBq, the pancreas of 42.5 μGy/MBq, and the upper large intestine of 34.2 μGy/MBq. The effective dose was calculated as 19.7 μSv/MBq according to the tissue weighting factor reported by ICRP-103. CONCLUSION Florzolotau intravenous injection was well tolerated in healthy male Japanese subjects. The effective dose was determined as 3.61 mSv when 185 MBq florzolotau was given.
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Affiliation(s)
| | - Chio Okuyama
- Shiga Medical Center Research Institute, Moriyama, Japan
| | - Shinya Kagawa
- Shiga Medical Center Research Institute, Moriyama, Japan
| | | | | | - Keisuke Takahata
- Institute for Quantum Medical Science, Quantum Life and Medical Science Directorate, National Institutes for Quantum Science and Technology, Chiba, Japan
| | | | - Hiroshi Yamauchi
- Shiga Medical Center Research Institute, Moriyama, Japan
- Department of Psychiatry, Graduate School of Medicine, Kyoto University, Kyoto, Japan
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13
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Varlow C, Vasdev N. Evaluation of Tau Radiotracers in Chronic Traumatic Encephalopathy. J Nucl Med 2023; 64:460-465. [PMID: 36109185 PMCID: PMC10071800 DOI: 10.2967/jnumed.122.264404] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Revised: 09/06/2022] [Accepted: 09/06/2022] [Indexed: 11/16/2022] Open
Abstract
Chronic traumatic encephalopathy (CTE) is a neurologic disorder associated with head injuries, diagnosed by the perivascular accumulation of hyperphosphorylated tau protein (phospho-tau) identified at autopsy. Tau PET radiopharmaceuticals developed for imaging Alzheimer disease are under evaluation for brain injuries. The goal of this study was to conduct a head-to-head in vitro evaluation of 5 tau PET radiotracers in subjects pathologically diagnosed with CTE. Methods: Autoradiography was used to assess the specific binding and distribution of 3H-flortaucipir (also known as Tauvid, AV-1451, and T807), 3H-MK-6240 (also known as florquinitau), 3H-PI-2620, 3H-APN-1607 (also known as PM-PBB3 and florzolotau), and 3H-CBD-2115 (also known as 3H-OXD-2115) in fresh-frozen human postmortem CTE brain tissue (stages I-IV). Immunohistochemistry was performed for phospho-tau with AT8, 3R tau with RD3, 4R tau with RD4 and amyloid-β with 6F/3D antibodies. Tau target density (maximum specific binding) was quantified by saturation analysis with 3H-flortaucipir in tissue sections. Results: 3H-flortaucipir demonstrated a positive signal in all CTE cases examined, with varying degrees of specific binding (68.7% ± 10.5%; n = 12) defined by homologous blockade and to a lesser extent by heterologous blockade with MK-6240 (27.3% ± 13.6%; n = 12). The 3H-flortaucipir signal was also displaced by the monoamine oxidase (MAO)-A inhibitor clorgyline (43.9% ± 4.6%; n = 3), indicating off-target binding to MAO-A. 3H-APN-1607 was moderately displaced in homologous blocking studies and was not displaced by 3H-flortaucipir; however, substantial displacement was observed when blocking with the β-amyloid-targeting compound NAV-4694. 3H-MK-6240 and 3H-PI-2620 had negligible binding in all but 2 CTE IV cases, and binding may be attributed to pathology severity or mixed Alzheimer disease/CTE pathology. 3H-CBD-2115 showed moderate binding, displaced under homologous blockade, and aligned with 4R-tau immunostaining. Conclusion: In human CTE tissues, 3H-flortaucipir and 3H-APN-1607 revealed off-target binding to MAO-A and amyloid-β, respectively, and should be considered if these radiotracers are used in PET imaging studies of patients with brain injuries. 3H-MK-6240 and 3H-PI-2620 bind to CTE tau in severe- or mixed-pathology cases, and their respective 18F PET radiotracers warrant further evaluation in patients with severe suspected CTE.
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Affiliation(s)
- Cassis Varlow
- Azrieli Centre for Neuro-Radiochemistry, Brain Health Imaging Centre, Centre for Addiction and Mental Health, and Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada
| | - Neil Vasdev
- Azrieli Centre for Neuro-Radiochemistry, Brain Health Imaging Centre, Centre for Addiction and Mental Health, and Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada
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14
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Singh P, Singh D, Srivastava P, Mishra G, Tiwari AK. Evaluation of advanced, pathophysiologic new targets for imaging of CNS. Drug Dev Res 2023; 84:484-513. [PMID: 36779375 DOI: 10.1002/ddr.22040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2022] [Revised: 12/12/2022] [Accepted: 12/31/2022] [Indexed: 02/14/2023]
Abstract
The inadequate information about the in vivo pathological, physiological, and neurological impairments, as well as the absence of in vivo tools for assessing brain penetrance and the efficiency of newly designed drugs, has hampered the development of new techniques for the treatment for variety of new central nervous system (CNS) diseases. The searching sites such as Science Direct and PubMed were used to find out the numerous distinct tracers across 16 CNS targets including tau, synaptic vesicle glycoprotein, the adenosine 2A receptor, the phosphodiesterase enzyme PDE10A, and the purinoceptor, among others. Among the most encouraging are [18 F]FIMX for mGluR imaging, [11 C]Martinostat for Histone deacetylase, [18 F]MNI-444 for adenosine 2A imaging, [11 C]ER176 for translocator protein, and [18 F]MK-6240 for tau imaging. We also reviewed the findings for each tracer's features and potential for application in CNS pathophysiology and therapeutic evaluation investigations, including target specificity, binding efficacy, and pharmacokinetic factors. This review aims to present a current evaluation of modern positron emission tomography tracers for CNS targets, with a focus on recent advances for targets that have newly emerged for imaging in humans.
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Affiliation(s)
- Priya Singh
- Department of Chemistry, Babasaheb Bhimrao Ambedkar University, Lucknow, Uttar Pradesh, India
| | - Deepika Singh
- Department of Chemistry, Babasaheb Bhimrao Ambedkar University, Lucknow, Uttar Pradesh, India
| | - Pooja Srivastava
- Division of Cyclotron and Radiopharmaceuticals Sciences, Institute of Nuclear Medicine and Allied Sciences, Delhi, India
| | - Gauri Mishra
- Department of Zoology, Swami Shraddhananad College, University of Delhi, Alipur, Delhi, India
| | - Anjani K Tiwari
- Department of Chemistry, Babasaheb Bhimrao Ambedkar University, Lucknow, Uttar Pradesh, India
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15
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Mohammadi Z, Alizadeh H, Marton J, Cumming P. The Sensitivity of Tau Tracers for the Discrimination of Alzheimer's Disease Patients and Healthy Controls by PET. Biomolecules 2023; 13:290. [PMID: 36830659 PMCID: PMC9953528 DOI: 10.3390/biom13020290] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Revised: 01/12/2023] [Accepted: 01/25/2023] [Indexed: 02/09/2023] Open
Abstract
Hyperphosphorylated tau aggregates, also known as neurofibrillary tangles, are a hallmark neuropathological feature of Alzheimer's disease (AD). Molecular imaging of tau by positron emission tomography (PET) began with the development of [18F]FDDNP, an amyloid β tracer with off-target binding to tau, which obtained regional specificity through the differing distributions of amyloid β and tau in AD brains. A concerted search for more selective and affine tau PET tracers yielded compounds belonging to at least eight structural categories; 18F-flortaucipir, known variously as [18F]-T807, AV-1451, and Tauvid®, emerged as the first tau tracer approved by the American Food and Drug Administration. The various tau tracers differ concerning their selectivity over amyloid β, off-target binding at sites such as monoamine oxidase and neuromelanin, and degree of uptake in white matter. While there have been many reviews of molecular imaging of tau in AD and other conditions, there has been no systematic comparison of the fitness of the various tracers for discriminating between AD patient and healthy control (HC) groups. In this narrative review, we endeavored to compare the binding properties of the various tau tracers in vitro and the effect size (Cohen's d) for the contrast by PET between AD patients and age-matched HC groups. The available tracers all gave good discrimination, with Cohen's d generally in the range of two-three in culprit brain regions. Overall, Cohen's d was higher for AD patient groups with more severe illness. Second-generation tracers, while superior concerning off-target binding, do not have conspicuously higher sensitivity for the discrimination of AD and HC groups. We suppose that available pharmacophores may have converged on a maximal affinity for tau fibrils, which may limit the specific signal imparted in PET studies.
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Affiliation(s)
- Zohreh Mohammadi
- Immunology Research Center, Tabriz University of Medical Sciences, Tabriz 5166/15731, Iran
- Student Research Committee, Tabriz University of Medical Sciences, Tabriz 5166/15731, Iran
| | - Hadi Alizadeh
- Immunology Research Center, Tabriz University of Medical Sciences, Tabriz 5166/15731, Iran
| | - János Marton
- ABX Advanced Biochemical Compounds Biomedizinische Forschungsreagenzien GmbH, Heinrich-Glaeser-Straße 10-14, D-01454 Radeberg, Germany
| | - Paul Cumming
- Department of Nuclear Medicine, Bern University Hospital, Freiburgstraße 18, CH-3010 Bern, Switzerland
- School of Psychology and Counselling, Queensland University of Technology, Brisbane, QLD 4059, Australia
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16
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Li XY, Jiao FY, Yao RX, Ju ZZ, Chen MJ, Ge JJ, Li G, Sun YM, Wu P, Wu JJ, Yen TC, Zuo C, Wang J, Lu JY, Liu FT. The Monoamine Oxidase-B Inhibitor Selegiline Does Not Affect 18 F-Florzolotau Uptake in Patients with Progressive Supranuclear Palsy: A Longitudinal Case Series. Mov Disord 2023; 38:705-707. [PMID: 36707403 DOI: 10.1002/mds.29328] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Revised: 01/04/2023] [Accepted: 01/05/2023] [Indexed: 01/29/2023] Open
Affiliation(s)
- Xin-Yi Li
- Department of Neurology, National Research Center for Aging and Medicine, National Center for Neurological Disorders, and State Key Laboratory of Medical Neurobiology, Huashan Hospital, Fudan University, Shanghai, China
| | - Fang-Yang Jiao
- Department of Nuclear Medicine & PET Center, National Center for Neurological Disorders, and National Clinical Research Center for Aging and Medicine, Huashan Hospital, Fudan University, Shanghai, China
| | - Rui-Xin Yao
- Department of Neurology, National Research Center for Aging and Medicine, National Center for Neurological Disorders, and State Key Laboratory of Medical Neurobiology, Huashan Hospital, Fudan University, Shanghai, China
| | - Zi-Zhao Ju
- Department of Nuclear Medicine & PET Center, National Center for Neurological Disorders, and National Clinical Research Center for Aging and Medicine, Huashan Hospital, Fudan University, Shanghai, China
| | - Ming-Jia Chen
- Department of Neurology, National Research Center for Aging and Medicine, National Center for Neurological Disorders, and State Key Laboratory of Medical Neurobiology, Huashan Hospital, Fudan University, Shanghai, China
| | - Jing-Jie Ge
- Department of Nuclear Medicine & PET Center, National Center for Neurological Disorders, and National Clinical Research Center for Aging and Medicine, Huashan Hospital, Fudan University, Shanghai, China
| | - Gen Li
- Department of Neurology, National Research Center for Aging and Medicine, National Center for Neurological Disorders, and State Key Laboratory of Medical Neurobiology, Huashan Hospital, Fudan University, Shanghai, China
| | - Yi-Min Sun
- Department of Neurology, National Research Center for Aging and Medicine, National Center for Neurological Disorders, and State Key Laboratory of Medical Neurobiology, Huashan Hospital, Fudan University, Shanghai, China
| | - Ping Wu
- Department of Nuclear Medicine & PET Center, National Center for Neurological Disorders, and National Clinical Research Center for Aging and Medicine, Huashan Hospital, Fudan University, Shanghai, China
| | - Jian-Jun Wu
- Department of Neurology, National Research Center for Aging and Medicine, National Center for Neurological Disorders, and State Key Laboratory of Medical Neurobiology, Huashan Hospital, Fudan University, Shanghai, China
| | | | - Chuantao Zuo
- Department of Nuclear Medicine & PET Center, National Center for Neurological Disorders, and National Clinical Research Center for Aging and Medicine, Huashan Hospital, Fudan University, Shanghai, China
| | - Jian Wang
- Department of Neurology, National Research Center for Aging and Medicine, National Center for Neurological Disorders, and State Key Laboratory of Medical Neurobiology, Huashan Hospital, Fudan University, Shanghai, China
| | - Jia-Ying Lu
- Department of Nuclear Medicine & PET Center, National Center for Neurological Disorders, and National Clinical Research Center for Aging and Medicine, Huashan Hospital, Fudan University, Shanghai, China
| | - Feng-Tao Liu
- Department of Neurology, National Research Center for Aging and Medicine, National Center for Neurological Disorders, and State Key Laboratory of Medical Neurobiology, Huashan Hospital, Fudan University, Shanghai, China
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17
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Gatto RG, Carlos AF, Reichard RR, Lowe VJ, Whitwell JL, Josephs KA. Comparative assessment of regional tau distribution by Tau-PET and Post-mortem neuropathology in a representative set of Alzheimer's & frontotemporal lobar degeneration patients. PLoS One 2023; 18:e0284182. [PMID: 37167210 PMCID: PMC10174492 DOI: 10.1371/journal.pone.0284182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Accepted: 03/24/2023] [Indexed: 05/13/2023] Open
Abstract
Flortaucipir (FTP) PET is a key imaging technique to evaluate tau burden indirectly. However, it appears to have greater utility for 3R+4R tau found in Alzheimer's disease (AD), compared to other non-AD tauopathies. The purpose of this study is to determine how flortaucipir uptake links to neuropathologically determined tau burden in AD and non-AD tauopathies. We identified nine individuals who had undergone antemortem tau-PET and postmortem neuropathological analyses. The cohort included three patients with low, moderate, and high AD neuropathologic changes (ADNC), five patients with a non-AD tauopathy (one Pick's disease, three progressive supranuclear palsies, and one globular glial tauopathy), and one control without ADNC. We compared regional flortaucipir PET uptake with tau burden using an anti-AT8 antibody. There was a very good correlation between flortaucipir uptake and tau burden in those with ADNC although, in one ADNC patient, flortaucipir uptake and tau burden did not match due to the presence of argyrophilic grains disease. Non-AD patients showed lower flortaucipir uptake globally compared to ADNC patients. In the non-AD patients, some regional associations between flortaucipir uptake and histopathological tau burden were observed. Flortaucipir uptake is strongly linked to underlying tau burden in patients with ADNC but there are instances where they do not match. On-the-other hand, flortaucipir has a limited capacity to represent histopathological tau burden in non-AD patients although there are instances where regional uptake correlates with regional tau burden. There is a definite need for the development of future generations of tau-PET ligands that can detect non-AD tau.
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Affiliation(s)
- Rodolfo G Gatto
- Department of Neurology, Mayo Clinic, Rochester, MN, United States of America
| | - Arenn F Carlos
- Department of Neurology, Mayo Clinic, Rochester, MN, United States of America
| | - R Ross Reichard
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, United States of America
| | - Val J Lowe
- Department of Radiology, Mayo Clinic, Rochester, MN, United States of America
| | - Jennifer L Whitwell
- Department of Radiology, Mayo Clinic, Rochester, MN, United States of America
| | - Keith A Josephs
- Department of Neurology, Mayo Clinic, Rochester, MN, United States of America
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18
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Holt A. Conventional Receptor Radioligand Binding Techniques Applied to the Study of Monoamine Oxidase. Methods Mol Biol 2023; 2558:75-96. [PMID: 36169857 DOI: 10.1007/978-1-0716-2643-6_7] [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] [Indexed: 06/16/2023]
Abstract
Designed to measure binding interactions between small molecules and receptor proteins, radioligand binding approaches may also be applied to interactions between monoamine oxidase (MAO) and its ligands. The technique may be used with tissue homogenates or with mitochondrial membranes and can provide information about binding site density, ligand affinity, binding rate constants, and binding events at sites that do not impact absorbance characteristics of the flavin cofactor and that may not be amenable to spectrophotometric studies. This overview describes the use of a cell harvester in a common filtration approach to measure binding to MAO of radiolabeled substrates, inhibitors, or allosteric ligands in saturation analyses and to take advantage of the principles of competition to obtain quantitative binding data for unlabeled ligands that may bind with much lower affinity. The quality and reproducibility of data are impacted by factors such as choice of ligand concentrations, pipetting technique, graphing and regression approaches, and scintillation counting parameters, and consideration is given to these and other factors that may influence the results.
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Affiliation(s)
- Andrew Holt
- Neurochemical Research Unit, Department of Psychiatry, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada.
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19
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Kallinen A, Kassiou M. Tracer development for PET imaging of proteinopathies. Nucl Med Biol 2022; 114-115:108-120. [PMID: 35487833 DOI: 10.1016/j.nucmedbio.2022.04.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Revised: 02/17/2022] [Accepted: 04/04/2022] [Indexed: 12/27/2022]
Abstract
This review outlines small molecule radiotracers developed for positron emission tomography (PET) imaging of proteinopathies, neurodegenerative diseases characterised by accumulation of malformed proteins, over the last two decades with the focus on radioligands that have progressed to clinical studies. Introduction provides a short summary of proteinopathy targets used for PET imaging, including vastly studied proteins Aβ and tau and emerging α-synuclein. In the main section, clinically relevant Aβ and tau radioligand classes and their properties are discussed, including an overview of lead compounds and radioligand candidates studied as α-synuclein imaging agents in the early discovery and preclinical development phase. Lastly, the specific challenges and future directions in proteinopathy radioligand development are summarized.
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Affiliation(s)
- Annukka Kallinen
- Garvan Institute of Medical Research, 384 Victoria St, NSW 2010, Australia.
| | - Michael Kassiou
- School of Chemistry, The University of Sydney, NSW 2006, Australia
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20
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Knight AC, Morrone CD, Varlow C, Yu WH, McQuade P, Vasdev N. Head-to-Head Comparison of Tau-PET Radioligands for Imaging TDP-43 in Post-Mortem ALS Brain. Mol Imaging Biol 2022; 25:513-527. [PMID: 36258099 DOI: 10.1007/s11307-022-01779-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 09/27/2022] [Accepted: 10/03/2022] [Indexed: 11/25/2022]
Abstract
PURPOSE In vivo detection of transactivation response element DNA binding protein-43 kDa (TDP-43) aggregates through positron emission tomography (PET) would impact the ability to successfully develop therapeutic interventions for a variety of neurodegenerative diseases, including amyotrophic lateral sclerosis (ALS). The purpose of the present study is to evaluate the ability of six tau PET radioligands to bind to TDP-43 aggregates in post-mortem brain tissues from ALS patients. PROCEDURES Herein, we report the first head-to-head evaluation of six tritium labeled isotopologs of tau-targeting PET radioligands, [3H]MK-6240 (a.k.a. florquinitau), [3H]Genentech Tau Probe-1 (GTP-1), [3H]JNJ-64326067(JNJ-067), [3H]CBD-2115, [3H]flortaucipir, and [3H]APN-1607, and their ability to bind to the β-pleated sheet structures of aggregate TDP-43 in post-mortem ALS brain tissues by autoradiography and immunostaining methods. Post-mortem frontal cortex, motor cortex, and cerebellum tissues were evaluated, and binding intensity was aligned with areas of elevated phosphorylated tau (ptau), pTDP-43, and β-amyloid. RESULTS Negligible binding was observed with [3H]MK-6240, [3H]JNJ-067, and [3H]GTP-1. While [3H]CBD-2115 displayed marginal specific binding, this binding did not significantly correlate with the distribution of pTDP-43 and AT8 inclusions. Of the remaining ligands, the distribution of [3H]flortaucipir did not significantly correlate to pTDP-43 pathology; however, specific binding trends to a positive relationship with tau. Finally, [3H]APN-1607 relates most strongly to amyloid load and does not indicate pTDP-43 pathology as confirmed by [3H]PiB distribution in sister sections. CONCLUSIONS Our results demonstrate the prominent nature of mixed pathology in ALS, and do not support the application of [3H]MK-6240, [3H]JNJ-067, [3H]GTP-1, [3H]CBD-2115, [3H]flortaucipir, or [3H]APN-1607 for selective imaging TDP-43 in ALS for clinical research with the currently available in vitro data. Identification of potent and selective radiotracers for TDP-43 remains an ongoing challenge.
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Affiliation(s)
- Ashley C Knight
- Azrieli Centre for Neuro-Radiochemistry, Brain Health Imaging Centre, Centre for Addiction and Mental Health, 250 College Street, Toronto, Canada
- Institute of Medical Science, University of Toronto, 1 King's College Circle, Toronto, Canada
| | - Christopher D Morrone
- Azrieli Centre for Neuro-Radiochemistry, Brain Health Imaging Centre, Centre for Addiction and Mental Health, 250 College Street, Toronto, Canada
| | - Cassis Varlow
- Azrieli Centre for Neuro-Radiochemistry, Brain Health Imaging Centre, Centre for Addiction and Mental Health, 250 College Street, Toronto, Canada
- Institute of Medical Science, University of Toronto, 1 King's College Circle, Toronto, Canada
| | - Wai Haung Yu
- Azrieli Centre for Neuro-Radiochemistry, Brain Health Imaging Centre, Centre for Addiction and Mental Health, 250 College Street, Toronto, Canada
- Department of Pharmacology and Toxicology, University of Toronto, 1 King's College Circle, Toronto, Canada
| | - Paul McQuade
- Takeda Pharmaceutical Company, Ltd, 35 Landsdowne Street, Cambridge, MA, USA
| | - Neil Vasdev
- Azrieli Centre for Neuro-Radiochemistry, Brain Health Imaging Centre, Centre for Addiction and Mental Health, 250 College Street, Toronto, Canada.
- Institute of Medical Science, University of Toronto, 1 King's College Circle, Toronto, Canada.
- Department of Psychiatry, University of Toronto, 250 College Street, Toronto, Canada.
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21
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Fu L, Zhang J, Zhou K, Zhang X, Xie H, Zhu M, Cui M, Wang R. In vivo imaging of tau deposition in Alzheimer’s disease using both [18F]-THK5317 and [18F]-S16: A pilot human study. Front Aging Neurosci 2022; 14:994750. [PMID: 36092808 PMCID: PMC9459225 DOI: 10.3389/fnagi.2022.994750] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Accepted: 08/11/2022] [Indexed: 11/13/2022] Open
Abstract
Objective To evaluate the effectiveness of a new tracer (S)-1-(4-(6-(dimethylamino)quinoxalin-2-yl)phenoxy)-3-fluoropropan-2-ol ([18F]-S16), in distinguishing patients with AD from HCs. Methods Paired [18F]-S16 and [18F]-THK5317 scans were acquired in five patients with AD, six HCs, one subject with a semantic variant of primary progressive aphasia (sv-PPA) and one subject with probable progressive supranuclear palsy (PSP). Dynamic PET scanning was performed over 90 min after injection of the tracers. Standardized uptake values (SUV) and cortical-to-cerebellum standardized uptake value ratios (SUVRs) were used for tau deposition semi-quantization. A voxel-based analysis was employed to assess the uptake difference between populations. Results [18F]-S16 exhibited excellent blood-brain-barrier penetration. AD patients showed increased cortical [18F]-THK5317 and [18F]-S16 binding. Compared to HCs, AD patients showed significantly increased cortical [18F]-S16 uptake in the bilateral occipital cortex, posterior cingulated cortex/precuneus, and lateral frontal cortex. Notable [18F]-S16 uptake was observed in the basal ganglia and brainstem compared to the neocortex. A substantial [18F]-S16 signal was detected in the basal ganglia and midbrain in a patient with probable PSP and in the bilateral anterior temporal cortex in a sv-PPA patient. Conclusion [18F]-S16 might be of help to detect tau protein in vivo.
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Affiliation(s)
- Liping Fu
- Department of Nuclear Medicine, China-Japan Friendship Hospital, Beijing, China
- *Correspondence: Liping Fu,
| | - Jinming Zhang
- Department of Nuclear Medicine, First Medical Center, Chinese PLA General Hospital, Beijing, China
| | - Kaixiang Zhou
- Key Laboratory of Radiopharmaceuticals, Ministry of Education, Beijing Normal University, Beijing, China
| | - Xiaojun Zhang
- Department of Nuclear Medicine, First Medical Center, Chinese PLA General Hospital, Beijing, China
| | - Hengge Xie
- Department of Neurology, The Second Medical Center, Chinese PLA General Hospital, Beijing, China
| | - Mingwei Zhu
- Department of Neurology, The Second Medical Center, Chinese PLA General Hospital, Beijing, China
| | - Mengchao Cui
- Key Laboratory of Radiopharmaceuticals, Ministry of Education, Beijing Normal University, Beijing, China
| | - Ruimin Wang
- Department of Nuclear Medicine, First Medical Center, Chinese PLA General Hospital, Beijing, China
- Ruimin Wang,
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22
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Mohamed AZ, Cumming P, Nasrallah FA. Escalation of Tau Accumulation after a Traumatic Brain Injury: Findings from Positron Emission Tomography. Brain Sci 2022; 12:876. [PMID: 35884683 PMCID: PMC9313362 DOI: 10.3390/brainsci12070876] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 06/27/2022] [Accepted: 06/28/2022] [Indexed: 01/27/2023] Open
Abstract
Traumatic brain injury (TBI) has come to be recognized as a risk factor for Alzheimer's disease (AD), with poorly understood underlying mechanisms. We hypothesized that a history of TBI would be associated with greater tau deposition in elders with high-risk for dementia. A Groups of 20 participants with self-reported history of TBI and 100 without any such history were scanned using [18F]-AV1451 positron emission tomography as part of the Alzheimer's Disease Neuroimaging Initiative (ADNI). Scans were stratified into four groups according to TBI history, and by clinical dementia rating scores into cognitively normal (CDR = 0) and those showing cognitive decline (CDR ≥ 0.5). We pursued voxel-based group comparison of [18F]-AV1451 uptake to identify the effect of TBI history on brain tau deposition, and for voxel-wise correlation analyses between [18F]-AV1451 uptake and different neuropsychological measures and cerebrospinal fluid (CSF) biomarkers. Compared to the TBI-/CDR ≥ 0.5 group, the TBI+/CDR ≥ 0.5 group showed increased tau deposition in the temporal pole, hippocampus, fusiform gyrus, and inferior and middle temporal gyri. Furthermore, the extent of tau deposition in the brain of those with TBI history positively correlated with the extent of cognitive decline, CSF-tau, and CSF-amyloid. This might suggest TBI to increase the risk for tauopathies and Alzheimer's disease later in life.
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Affiliation(s)
- Abdalla Z. Mohamed
- Thompson Institute, University of Sunshine Coast, Birtinya, QLD 4575, Australia;
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Paul Cumming
- Department of Nuclear Medicine, Bern University Hospital, 3010 Bern, Switzerland;
- School of Psychology and Counselling, Queensland University of Technology, Brisbane, QLD 4059, Australia
| | - Fatima A. Nasrallah
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
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23
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Künze G, Kümpfel R, Rullmann M, Barthel H, Brendel M, Patt M, Sabri O. Molecular Simulations Reveal Distinct Energetic and Kinetic Binding Properties of [ 18F]PI-2620 on Tau Filaments from 3R/4R and 4R Tauopathies. ACS Chem Neurosci 2022; 13:2222-2234. [PMID: 35762647 DOI: 10.1021/acschemneuro.2c00291] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Tauopathies are a class of neurodegenerative disorders characterized by the accumulation of tau protein filaments in the brain. On the basis of isoforms with three or four microtubule-binding repeats (3R or 4R) that constitute tau filaments, tauopathies can be divided into 3R, 4R, and 3R/4R tauopathies. [18F]PI-2620 is a tau-positron emission tomography (PET) tracer that detects tau filaments in the 3R/4R tauopathy Alzheimer's disease (AD) and the 4R tauopathies corticobasal degeneration (CBD) and progressive supranuclear palsy (PSP) with differential binding characteristics. A multiscale simulation workflow, including molecular docking, molecular dynamics simulation, metadynamics, and Brownian dynamics, was applied to uncover the molecular basis for the different binding properties of [18F]PI-2620 in these tauopathies. The energetically best binding sites of [18F]PI-2620 in the AD-tau filament are located in the C-shaped groove of the filament core structure that is accessible to the outside. The most favorable binding sites in CBD-tau and PSP-tau filaments are localized to cavities in the inner filament core. Sites on the outer surface have higher binding free energies, and interaction of [18F]PI-2620 at these sites was short-lived in the molecular dynamics simulations. Computationally predicted associated rates of [18F]PI-2620 with the groove sites in the AD-tau filament were higher than association rates with the cavity sites in the CBD- and PSP-tau filaments. The results indicate that tau filaments in AD combine favorable energetic and kinetic properties with regard to tracer binding, while the binding of [18F]PI-2620 to filaments in CBD and PSP is kinetically restricted. Our findings reveal that distinct structural, energetic, and kinetic properties of tau filaments from AD, CBD, and PSP govern their interaction with PET tracers, which highlights the possibility to achieve tau isoform specificity in future tracer developments.
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Affiliation(s)
- Georg Künze
- Institute for Drug Discovery, University of Leipzig, 04103 Leipzig, Germany
| | - Richy Kümpfel
- Institute for Drug Discovery, University of Leipzig, 04103 Leipzig, Germany
| | - Michael Rullmann
- Department of Nuclear Medicine, University of Leipzig, Leipzig 04103, Germany
| | - Henryk Barthel
- Department of Nuclear Medicine, University of Leipzig, Leipzig 04103, Germany
| | - Matthias Brendel
- Department of Nuclear Medicine, University Hospital of Munich, LMU Munich, 81377 Munich, Germany.,German Center for Neurodegenerative Diseases (DZNE), Munich 81377, Germany.,Munich Cluster for Systems Neurology (SyNergy), Munich 81377, Germany
| | - Marianne Patt
- Department of Nuclear Medicine, University of Leipzig, Leipzig 04103, Germany
| | - Osama Sabri
- Department of Nuclear Medicine, University of Leipzig, Leipzig 04103, Germany
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24
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Josephs KA, Tosakulwong N, Weigand SD, Buciuc M, Lowe VJ, Dickson DW, Whitwell JL. Relationship Between 18F-Flortaucipir Uptake and Histologic Lesion Types in 4-Repeat Tauopathies. J Nucl Med 2022; 63:931-935. [PMID: 34556525 PMCID: PMC9157721 DOI: 10.2967/jnumed.121.262685] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Revised: 09/21/2021] [Indexed: 11/16/2022] Open
Abstract
Progressive supranuclear palsy (PSP) and corticobasal degeneration (CBD) are 4-repeat (4R) tauopathies with overlapping, but also morphologically distinct, tau immunoreactive lesions that vary in count by brain region. 18F-flortaucipir PET uptake has been reported to correlate with overall tau burden, and-in 1 CBD case-to have greater affinity to threads than tangles. We determined whether 18F-flortaucipir uptake is associated with histologic lesion type in 4R tauopathies. Methods: We performed semiquantitative regional lesion counts on pretangles/neurofibrillary tangles, threads, oligodendroglial coiled bodies, tufted astrocytes, and astrocytic plaques in 29 cases of autopsied 4R tauopathy (PSP, 16; CBD, 13). Regression models were used for statistical analyses. Results:18F-flortaucipir uptake marginally correlated with threads in the precentral cortex (P = 0.04) and with astrocytic lesions in the red nucleus (P = 0.05). Conclusion: The findings do not support 18F-flortaucipir's having differential affinity to any 4R tau lesion type.
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Affiliation(s)
| | | | - Stephen D Weigand
- Department of Health Sciences Research, Mayo Clinic, Rochester, Minnesota
| | - Marina Buciuc
- Department of Neurology, Mayo Clinic, Rochester, Minnesota
| | - Val J Lowe
- Department of Radiology, Mayo Clinic, Rochester, Minnesota; and
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25
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Wright JP, Goodman JR, Lin YG, Lieberman BP, Clemens J, Gomez LF, Liang Q, Hoye AT, Pontecorvo MJ, Conway KA. Monoamine oxidase binding not expected to significantly affect [ 18F]flortaucipir PET interpretation. Eur J Nucl Med Mol Imaging 2022; 49:3797-3808. [PMID: 35596745 PMCID: PMC9399028 DOI: 10.1007/s00259-022-05822-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Accepted: 04/25/2022] [Indexed: 11/28/2022]
Abstract
Purpose [18F]-labeled positron emission tomography (PET) radioligands permit in vivo assessment of Alzheimer’s disease biomarkers, including aggregated neurofibrillary tau (NFT) with [18F]flortaucipir. Due to structural similarities of flortaucipir with some monoamine oxidase A (MAO-A) inhibitors, this study aimed to evaluate flortaucipir binding to MAO-A and MAO-B and any potential impact on PET interpretation. Methods [18F]Flortaucipir autoradiography was performed on frozen human brain tissue slices, and PET imaging was conducted in rats. Dissociation constants were determined by saturation binding, association and dissociation rates were measured by kinetic binding experiments, and IC50 values were determined by competition binding. Results Under stringent wash conditions, specific [18F]flortaucipir binding was observed on tau NFT-rich Alzheimer’s disease tissue and not control tissue. In vivo PET experiments in rats revealed no evidence of [18F]flortaucipir binding to MAO-A; pre-treatment with MAO inhibitor pargyline did not impact uptake or wash-out of [18F]flortaucipir. [18F]Flortaucipir bound with low nanomolar affinity to human MAO-A in a microsomal preparation in vitro but with a fast dissociation rate relative to MAO-A ligand fluoroethyl-harmol, consistent with no observed in vivo binding in rats of [18F]flortaucipir to MAO-A. Direct binding of flortaucipir to human MAO-B was not detected in a microsomal preparation. A high concentration of flortaucipir (IC50 of 1.3 μM) was found to block binding of the MAO-B ligand safinamide to MAO-B on microsomes suggesting that, at micromolar concentrations, flortaucipir weakly binds to MAO-B in vitro. Conclusion These data suggest neither MAO-A nor MAO-B binding will contribute significantly to the PET signal in cortical target areas relevant to the interpretation of [18F]flortaucipir. Supplementary Information The online version contains supplementary material available at 10.1007/s00259-022-05822-9.
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Affiliation(s)
- Justin P Wright
- Avid Radiopharmaceuticals, Eli Lilly & Company, Philadelphia, PA, USA
| | - Jason R Goodman
- Avid Radiopharmaceuticals, Eli Lilly & Company, Philadelphia, PA, USA
| | - Yin-Guo Lin
- Avid Radiopharmaceuticals, Eli Lilly & Company, Philadelphia, PA, USA
| | - Brian P Lieberman
- Avid Radiopharmaceuticals, Eli Lilly & Company, Philadelphia, PA, USA
| | - Jennifer Clemens
- Avid Radiopharmaceuticals, Eli Lilly & Company, Philadelphia, PA, USA
| | - Luis F Gomez
- Avid Radiopharmaceuticals, Eli Lilly & Company, Philadelphia, PA, USA
| | - Qianwa Liang
- Avid Radiopharmaceuticals, Eli Lilly & Company, Philadelphia, PA, USA
| | - Adam T Hoye
- Avid Radiopharmaceuticals, Eli Lilly & Company, Philadelphia, PA, USA
| | | | - Kelly A Conway
- Avid Radiopharmaceuticals, Eli Lilly & Company, Philadelphia, PA, USA.
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26
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Crișan G, Moldovean-Cioroianu NS, Timaru DG, Andrieș G, Căinap C, Chiș V. Radiopharmaceuticals for PET and SPECT Imaging: A Literature Review over the Last Decade. Int J Mol Sci 2022; 23:ijms23095023. [PMID: 35563414 PMCID: PMC9103893 DOI: 10.3390/ijms23095023] [Citation(s) in RCA: 60] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2022] [Revised: 04/23/2022] [Accepted: 04/28/2022] [Indexed: 02/04/2023] Open
Abstract
Positron emission tomography (PET) uses radioactive tracers and enables the functional imaging of several metabolic processes, blood flow measurements, regional chemical composition, and/or chemical absorption. Depending on the targeted processes within the living organism, different tracers are used for various medical conditions, such as cancer, particular brain pathologies, cardiac events, and bone lesions, where the most commonly used tracers are radiolabeled with 18F (e.g., [18F]-FDG and NA [18F]). Oxygen-15 isotope is mostly involved in blood flow measurements, whereas a wide array of 11C-based compounds have also been developed for neuronal disorders according to the affected neuroreceptors, prostate cancer, and lung carcinomas. In contrast, the single-photon emission computed tomography (SPECT) technique uses gamma-emitting radioisotopes and can be used to diagnose strokes, seizures, bone illnesses, and infections by gauging the blood flow and radio distribution within tissues and organs. The radioisotopes typically used in SPECT imaging are iodine-123, technetium-99m, xenon-133, thallium-201, and indium-111. This systematic review article aims to clarify and disseminate the available scientific literature focused on PET/SPECT radiotracers and to provide an overview of the conducted research within the past decade, with an additional focus on the novel radiopharmaceuticals developed for medical imaging.
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Affiliation(s)
- George Crișan
- Faculty of Physics, Babeş-Bolyai University, Str. M. Kogălniceanu 1, 400084 Cluj-Napoca, Romania; (G.C.); (N.S.M.-C.); (D.-G.T.)
- Department of Nuclear Medicine, County Clinical Hospital, Clinicilor 3-5, 400006 Cluj-Napoca, Romania;
| | | | - Diana-Gabriela Timaru
- Faculty of Physics, Babeş-Bolyai University, Str. M. Kogălniceanu 1, 400084 Cluj-Napoca, Romania; (G.C.); (N.S.M.-C.); (D.-G.T.)
| | - Gabriel Andrieș
- Department of Nuclear Medicine, County Clinical Hospital, Clinicilor 3-5, 400006 Cluj-Napoca, Romania;
| | - Călin Căinap
- The Oncology Institute “Prof. Dr. Ion Chiricuţă”, Republicii 34-36, 400015 Cluj-Napoca, Romania;
| | - Vasile Chiș
- Faculty of Physics, Babeş-Bolyai University, Str. M. Kogălniceanu 1, 400084 Cluj-Napoca, Romania; (G.C.); (N.S.M.-C.); (D.-G.T.)
- Institute for Research, Development and Innovation in Applied Natural Sciences, Babeș-Bolyai University, Str. Fântânele 30, 400327 Cluj-Napoca, Romania
- Correspondence:
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Abstract
PURPOSE OF REVIEW This article reviews tau PET imaging with an emphasis on first-generation and second-generation tau radiotracers and their application in neurodegenerative disorders, including Alzheimer's disease and non-Alzheimer's disease tauopathies. RECENT FINDINGS Tau is a critical protein, abundant in neurons within the central nervous system, which plays an important role in maintaining microtubules by binding to tubulin in axons. In its abnormal hyperphosphorylated form, accumulation of tau has been linked to a variety of neurodegenerative disorders, collectively referred to as tauopathies, which include Alzheimer's disease and non-Alzheimer's disease tauopathies [e.g., corticobasal degeneration (CBD), argyrophilic grain disease, progressive supranuclear palsy (PSP), and Pick's disease]. A number of first-generation and second-generation tau PET radiotracers have been developed, including the first FDA-approved agent [18F]-flortaucipir, which allow for in-vivo molecular imaging of underlying histopathology antemortem, ultimately guiding disease staging and development of disease-modifying therapeutics. SUMMARY Tau PET is an emerging imaging modality in the diagnosis and staging of tauopathies.
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Affiliation(s)
| | - Michelle Roytman
- Department of Radiology, New York-Presbyterian Hospital/Weill Cornell Medical College, New York
| | - Gloria C. Chiang
- Department of Radiology, New York-Presbyterian Hospital/Weill Cornell Medical College, New York
| | - Yi Li
- Department of Radiology, New York-Presbyterian Hospital/Weill Cornell Medical College, New York
| | - Marc L. Gordon
- Departments of Neurology and Psychiatry, Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, The Litwin-Zucker Research Center, Feinstein Institutes for Medical Research, Manhasset
| | - Ana M. Franceschi
- Neuroradiology Division, Department of Radiology, Northwell Health/Donald and Barbara Zucker School of Medicine, Lenox Hill Hospital, New York, New York, USA
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28
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Harada R, Furumoto S, Kudo Y, Yanai K, Villemagne VL, Okamura N. Imaging of Reactive Astrogliosis by Positron Emission Tomography. Front Neurosci 2022; 16:807435. [PMID: 35210989 PMCID: PMC8862631 DOI: 10.3389/fnins.2022.807435] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Accepted: 01/14/2022] [Indexed: 11/13/2022] Open
Abstract
Many neurodegenerative diseases are neuropathologically characterized by neuronal loss, gliosis, and the deposition of misfolded proteins such as β-amyloid (Aβ) plaques and tau tangles in Alzheimer’s disease (AD). In postmortem AD brains, reactive astrocytes and activated microglia are observed surrounding Aβ plaques and tau tangles. These activated glial cells secrete pro-inflammatory cytokines and reactive oxygen species, which may contribute to neurodegeneration. Therefore, in vivo imaging of glial response by positron emission tomography (PET) combined with Aβ and tau PET would provide new insights to better understand the disease process, as well as aid in the differential diagnosis, and monitoring glial response disease-specific therapeutics. There are two promising targets proposed for imaging reactive astrogliosis: monoamine oxidase-B (MAO-B) and imidazoline2 binding site (I2BS), which are predominantly expressed in the mitochondrial membranes of astrocytes and are upregulated in various neurodegenerative conditions. PET tracers targeting these two MAO-B and I2BS have been evaluated in humans. [18F]THK-5351, which was originally designed to target tau aggregates in AD, showed high affinity for MAO-B and clearly visualized reactive astrocytes in progressive supranuclear palsy (PSP). However, the lack of selectivity of [18F]THK-5351 binding to both MAO-B and tau, severely limits its clinical utility as a biomarker. Recently, [18F]SMBT-1 was developed as a selective and reversible MAO-B PET tracer via compound optimization of [18F]THK-5351. In this review, we summarize the strategy underlying molecular imaging of reactive astrogliosis and clinical studies using MAO-B and I2BS PET tracers.
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Affiliation(s)
- Ryuichi Harada
- Department of Pharmacology, Tohoku University Graduate School of Medicine, Sendai, Japan
- *Correspondence: Ryuichi Harada,
| | - Shozo Furumoto
- Cyclotron and Radioisotope Center, Tohoku University, Sendai, Japan
| | - Yukitsuka Kudo
- Department of New Therapeutics Innovation for Alzheimer’s and Dementia, Institute of Development and Aging, Tohoku University, Sendai, Japan
| | - Kazuhiko Yanai
- Department of Pharmacology, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Victor L. Villemagne
- Department of Molecular Imaging and Therapy, Austin Health, Melbourne, VIC, Australia
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, United States
| | - Nobuyuki Okamura
- Division of Pharmacology, Faculty of Medicine, Tohoku Medical and Pharmaceutical University, Sendai, Japan
- Nobuyuki Okamura,
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Prem Kumar A, Singh N, Nair D, Justin A. Neuronal PET tracers for Alzheimer's disease. Biochem Biophys Res Commun 2022; 587:58-62. [PMID: 34864547 DOI: 10.1016/j.bbrc.2021.11.093] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Revised: 11/25/2021] [Accepted: 11/25/2021] [Indexed: 11/02/2022]
Abstract
Advancements in brain imaging techniques have emerged as a significant tool in detecting Alzheimer's disease (AD) progression. The complicated cascade of AD progression can be detected using radio imaging, especially with Positron emission tomography (PET). The review focus on recently introduced investigational PET tracers targeting neurofibrillary tau aggregates found typically in AD. Herein, we also address the use of different PET tracers and the clinical implementation of established and newer generation tracers. This review also intends to discuss the importance of several PET radiotracers and challenges in PET imaging.
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Affiliation(s)
- Ashwini Prem Kumar
- Department of Pharmacology, JSS College of Pharmacy, JSS Academy of Higher Education & Research, Ooty, 643001, Nilgiris, Tamilnadu, India
| | - Nivedita Singh
- Centre for Neuroscience, Indian Institute of Science, Bangalore, 560012, Karnataka, India
| | - Deepak Nair
- Centre for Neuroscience, Indian Institute of Science, Bangalore, 560012, Karnataka, India
| | - Antony Justin
- Department of Pharmacology, JSS College of Pharmacy, JSS Academy of Higher Education & Research, Ooty, 643001, Nilgiris, Tamilnadu, India.
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Jia H, Xie T. Tracers progress for positron emission tomography imaging of glial-related disease. J Biomed Res 2022; 36:321-335. [PMID: 36131689 PMCID: PMC9548440 DOI: 10.7555/jbr.36.20220017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Glial cells play an essential part in the neuron system. They can not only serve as structural blocks in the human brain but also participate in many biological processes. Extensive studies have shown that astrocytes and microglia play an important role in neurodegenerative diseases, such as Alzheimer's disease, Parkinson's disease, Huntington's disease, as well as glioma, epilepsy, ischemic stroke, and infections. Positron emission tomography is a functional imaging technique providing molecular-level information before anatomic changes are visible and has been widely used in many above-mentioned diseases. In this review, we focus on the positron emission tomography tracers used in pathologies related to glial cells, such as glioma, Alzheimer's disease, and neuroinflammation.
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Affiliation(s)
- Haoran Jia
- Institute of Radiation Medicine, Fudan University, Shanghai 200032, China
| | - Tianwu Xie
- Institute of Radiation Medicine, Fudan University, Shanghai 200032, China
- Tianwu Xie, Institute of Radiation Medicine, Fudan University, 2094 Xietu Road, Shanghai 200032, China. Tel: +86-21-64048363, E-mail:
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31
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Brumberg J, Varrone A. New PET radiopharmaceuticals for imaging CNS diseases. Nucl Med Mol Imaging 2022. [DOI: 10.1016/b978-0-12-822960-6.00002-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
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Kroth H, Oden F, Serra AM, Molette J, Mueller A, Berndt M, Capotosti F, Gabellieri E, Schmitt-Willich H, Hickman D, Pfeifer A, Dinkelborg L, Stephens A. Structure-activity relationship around PI-2620 highlights the importance of the nitrogen atom position in the tricyclic core. Bioorg Med Chem 2021; 52:116528. [PMID: 34839158 DOI: 10.1016/j.bmc.2021.116528] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Revised: 11/12/2021] [Accepted: 11/16/2021] [Indexed: 10/19/2022]
Abstract
Tau aggregates represent a critical pathology in Alzheimer's disease (AD) and other forms of dementia. The extent of Tau neurofibrillary tangles across defined brain regions corresponds well to the observed level of cognitive decline in AD. Compound 1 (PI-2620) was recently identified as a promising Tau positron emission tomography tracer for AD and non-AD tauopathies. To evaluate the impact of the N-atom position with respect to Tau- and off-target binding, tricyclic core analogs of PI-2620 with nitrogen atoms at different positions were prepared. Affinity to aggregated Tau was evaluated using human AD brain homogenates, and their off-target binding was evaluated in a monoamine oxidase A (MAO-A) competition assay. The novel tricyclic core derivatives all displayed inferior Tau binding or MAO-A off-target selectivity, indicating PI-2620 to be the optimal design for high affinity binding to Tau and high MAO-A selectivity.
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Affiliation(s)
- Heiko Kroth
- AC Immune SA, EPFL Innovation Park, Building B, 1015 Lausanne, Switzerland.
| | - Felix Oden
- Life Molecular Imaging GmbH, Tegeler Strasse 6-7, 13353 Berlin, Germany
| | | | - Jerome Molette
- AC Immune SA, EPFL Innovation Park, Building B, 1015 Lausanne, Switzerland
| | - Andre Mueller
- Life Molecular Imaging GmbH, Tegeler Strasse 6-7, 13353 Berlin, Germany
| | - Mathias Berndt
- Life Molecular Imaging GmbH, Tegeler Strasse 6-7, 13353 Berlin, Germany
| | | | | | | | - David Hickman
- AC Immune SA, EPFL Innovation Park, Building B, 1015 Lausanne, Switzerland
| | - Andrea Pfeifer
- AC Immune SA, EPFL Innovation Park, Building B, 1015 Lausanne, Switzerland
| | - Ludger Dinkelborg
- Life Molecular Imaging GmbH, Tegeler Strasse 6-7, 13353 Berlin, Germany
| | - Andrew Stephens
- Life Molecular Imaging GmbH, Tegeler Strasse 6-7, 13353 Berlin, Germany
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Ricci M, Cimini A, Camedda R, Chiaravalloti A, Schillaci O. Tau Biomarkers in Dementia: Positron Emission Tomography Radiopharmaceuticals in Tauopathy Assessment and Future Perspective. Int J Mol Sci 2021; 22:ijms222313002. [PMID: 34884804 PMCID: PMC8657996 DOI: 10.3390/ijms222313002] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Revised: 11/14/2021] [Accepted: 11/25/2021] [Indexed: 01/20/2023] Open
Abstract
Abnormal accumulation of Tau protein is closely associated with neurodegeneration and cognitive impairment and it is a biomarker of neurodegeneration in the dementia field, especially in Alzheimer’s disease (AD); therefore, it is crucial to be able to assess the Tau deposits in vivo. Beyond the fluid biomarkers of tauopathy described in this review in relationship with the brain glucose metabolic patterns, this review aims to focus on tauopathy assessment by using Tau PET imaging. In recent years, several first-generation Tau PET tracers have been developed and applied in the dementia field. Common limitations of first-generation tracers include off-target binding and subcortical white-matter uptake; therefore, several institutions are working on developing second-generation Tau tracers. The increasing knowledge about the distribution of first- and second-generation Tau PET tracers in the brain may support physicians with Tau PET data interpretation, both in the research and in the clinical field, but an updated description of differences in distribution patterns among different Tau tracers, and in different clinical conditions, has not been reported yet. We provide an overview of first- and second-generation tracers used in ongoing clinical trials, also describing the differences and the properties of novel tracers, with a special focus on the distribution patterns of different Tau tracers. We also describe the distribution patterns of Tau tracers in AD, in atypical AD, and further neurodegenerative diseases in the dementia field.
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Affiliation(s)
- Maria Ricci
- Department of Biomedicine and Prevention, University of Rome Tor Vergata, 00133 Rome, Italy; (A.C.); (R.C.); (A.C.); (O.S.)
- Correspondence:
| | - Andrea Cimini
- Department of Biomedicine and Prevention, University of Rome Tor Vergata, 00133 Rome, Italy; (A.C.); (R.C.); (A.C.); (O.S.)
| | - Riccardo Camedda
- Department of Biomedicine and Prevention, University of Rome Tor Vergata, 00133 Rome, Italy; (A.C.); (R.C.); (A.C.); (O.S.)
| | - Agostino Chiaravalloti
- Department of Biomedicine and Prevention, University of Rome Tor Vergata, 00133 Rome, Italy; (A.C.); (R.C.); (A.C.); (O.S.)
- Nuclear Medicine Section, IRCCS Neuromed, 86077 Pozzilli, Italy
| | - Orazio Schillaci
- Department of Biomedicine and Prevention, University of Rome Tor Vergata, 00133 Rome, Italy; (A.C.); (R.C.); (A.C.); (O.S.)
- Nuclear Medicine Section, IRCCS Neuromed, 86077 Pozzilli, Italy
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Colato E, Chiotis K, Ferreira D, Mazrina MS, Lemoine L, Mohanty R, Westman E, Nordberg A, Rodriguez-Vieitez E. Assessment of Tau Pathology as Measured by 18F-THK5317 and 18F-Flortaucipir PET and Their Relation to Brain Atrophy and Cognition in Alzheimer's Disease. J Alzheimers Dis 2021; 84:103-117. [PMID: 34511502 PMCID: PMC8609906 DOI: 10.3233/jad-210614] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND In Alzheimer's disease (AD), the abnormal aggregation of hyperphosphorylated tau leads to synaptic dysfunction and neurodegeneration. Recently developed tau PET imaging tracers are candidate biomarkers for diagnosis and staging of AD. OBJECTIVE We aimed to investigate the discriminative ability of 18F-THK5317 and 18F-flortaucipir tracers and brain atrophy at different stages of AD, and their respective associations with cognition. METHODS Two cohorts, each including 29 participants (healthy controls [HC], prodromal AD, and AD dementia patients), underwent 18F-THK5317 or 18F-flortaucipir PET, T1-weighted MRI, and neuropsychological assessment. For each subject, we quantified regional 18F-THK5317 and 18F-flortaucipir uptake within six bilateral and two composite regions of interest. We assessed global brain atrophy for each individual by quantifying the brain volume index, a measure of brain volume-to-cerebrospinal fluid ratio. We then quantified the discriminative ability of regional 18F-THK5317, 18F-flortaucipir, and brain volume index between diagnostic groups, and their associations with cognition in patients. RESULTS Both 18F-THK5317 and 18F-flortaucipir outperformed global brain atrophy in discriminating between HC and both prodromal AD and AD dementia groups. 18F-THK5317 provided the highest discriminative ability between HC and prodromal AD groups. 18F-flortaucipir performed best at discriminating between prodromal and dementia stages of AD. Across all patients, both tau tracers were predictive of RAVL learning, but only 18F-flortaucipir predicted MMSE. CONCLUSION Our results warrant further in vivo head-to-head and antemortem-postmortem evaluations. These validation studies are needed to select tracers with high clinical validity as biomarkers for early diagnosis, prognosis, and disease staging, which will facilitate their incorporation in clinical practice and therapeutic trials.
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Affiliation(s)
- Elisa Colato
- Division of Clinical Geriatrics, Center for Alzheimer Research, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden
| | - Konstantinos Chiotis
- Division of Clinical Geriatrics, Center for Alzheimer Research, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden.,Department of Neurology, Karolinska University Hospital, Stockholm, Sweden
| | - Daniel Ferreira
- Division of Clinical Geriatrics, Center for Alzheimer Research, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden
| | - Mariam S Mazrina
- Division of Clinical Geriatrics, Center for Alzheimer Research, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden
| | - Laetitia Lemoine
- Division of Clinical Geriatrics, Center for Alzheimer Research, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden
| | - Rosaleena Mohanty
- Division of Clinical Geriatrics, Center for Alzheimer Research, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden
| | - Eric Westman
- Division of Clinical Geriatrics, Center for Alzheimer Research, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden
| | - Agneta Nordberg
- Division of Clinical Geriatrics, Center for Alzheimer Research, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden.,Theme Aging, Karolinska University Hospital, Stockholm, Sweden
| | - Elena Rodriguez-Vieitez
- Division of Clinical Geriatrics, Center for Alzheimer Research, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden
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Klingstedt T, Shirani H, Ghetti B, Vidal R, R. Nilsson KP. Thiophene-Based Optical Ligands That Selectively Detect Aβ Pathology in Alzheimer's Disease. Chembiochem 2021; 22:2568-2581. [PMID: 34101954 PMCID: PMC8409278 DOI: 10.1002/cbic.202100199] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 06/04/2021] [Indexed: 11/25/2022]
Abstract
In several neurodegenerative diseases, the presence of aggregates of specific proteins in the brain is a significant pathological hallmark; thus, developing ligands able to bind to the aggregated proteins is essential for any effort related to imaging and therapeutics. Here we report the synthesis of thiophene-based ligands containing nitrogen heterocycles. The ligands selectively recognized amyloid-β (Aβ) aggregates in brain tissue from individuals diagnosed neuropathologically as having Alzheimer's disease (AD). The selectivity for Aβ was dependent on the position of nitrogen in the heterocyclic compounds, and the ability to bind Aβ was shown to be reduced when introducing anionic substituents on the thiophene backbone. Our findings provide the structural and functional basis for the development of ligands that can differentiate between aggregated proteinaceous species comprised of distinct proteins. These ligands might also be powerful tools for studying the pathogenesis of Aβ aggregation and for designing molecules for imaging of Aβ pathology.
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Affiliation(s)
- Therése Klingstedt
- Department of PhysicsChemistry and BiologyLinköping UniversitySE-581 83LinköpingSweden
| | - Hamid Shirani
- Department of PhysicsChemistry and BiologyLinköping UniversitySE-581 83LinköpingSweden
| | - Bernardino Ghetti
- Department of Pathology and Laboratory MedicineIndiana University School of MedicineIndianapolis46202IndianaUSA
| | - Ruben Vidal
- Department of Pathology and Laboratory MedicineIndiana University School of MedicineIndianapolis46202IndianaUSA
| | - K. Peter R. Nilsson
- Department of PhysicsChemistry and BiologyLinköping UniversitySE-581 83LinköpingSweden
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36
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Bischof GN, Dodich A, Boccardi M, van Eimeren T, Festari C, Barthel H, Hansson O, Nordberg A, Ossenkoppele R, Sabri O, Giovanni BFG, Garibotto V, Drzezga A. Clinical validity of second-generation tau PET tracers as biomarkers for Alzheimer's disease in the context of a structured 5-phase development framework. Eur J Nucl Med Mol Imaging 2021; 48:2110-2120. [PMID: 33590274 PMCID: PMC8175320 DOI: 10.1007/s00259-020-05156-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Accepted: 12/07/2020] [Indexed: 12/16/2022]
Abstract
PURPOSE In 2017, the Geneva Alzheimer's disease (AD) strategic biomarker roadmap initiative proposed a framework of the systematic validation AD biomarkers to harmonize and accelerate their development and implementation in clinical practice. Here, we use this framework to examine the translatability of the second-generation tau PET tracers into the clinical context. METHODS All available literature was systematically searched based on a set of search terms that related independently to analytic validity (phases 1-2), clinical validity (phase 3-4), and clinical utility (phase 5). The progress on each of the phases was determined based on scientific criteria applied for each phase and coded as fully, partially, preliminary achieved or not achieved at all. RESULTS The validation of the second-generation tau PET tracers has successfully passed the analytical phase 1 of the strategic biomarker roadmap. Assay definition studies showed evidence on the superiority over first-generation tau PET tracers in terms of off-target binding. Studies have partially achieved the primary aim of the analytical validity stage (phase 2), and preliminary evidence has been provided for the assessment of covariates on PET signal retention. Studies investigating of the clinical validity in phases 3, 4, and 5 are still underway. CONCLUSION The current literature provides overall preliminary evidence on the establishment of the second-generation tau PET tracers into the clinical context, thereby successfully addressing some methodological issues from the tau PET tracer of the first generation. Nevertheless, bigger cohort studies, longitudinal follow-up, and examination of diverse disease population are still needed to gauge their clinical validity.
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Affiliation(s)
- Gérard N Bischof
- Department of Nuclear Medicine, University Hospital Cologne, Cologne, Germany.
| | - Alessandra Dodich
- NIMTlab, Neuroimaging and Innovative Molecular Tracers Laboratory, University of Geneva, Geneva, Switzerland
- Center for Neurocognitive Rehabilitation (CeRiN), CIMeC, University of Trento, Trento, Italy
| | - Marina Boccardi
- German Center for Neurodegenerative Disorders (DZNE), Rostock/Greifswald, Rostock, Germany
- German Center for Neurodegenerative Disorders (DZNE), Bonn/Cologne, Germany
| | - Thilo van Eimeren
- Department of Nuclear Medicine, University Hospital Cologne, Cologne, Germany
- German Center for Neurodegenerative Disorders (DZNE), Rostock/Greifswald, Rostock, Germany
- German Center for Neurodegenerative Disorders (DZNE), Bonn/Cologne, Germany
| | - Cristina Festari
- LANE - Laboratory of Alzheimer's Neuroimaging and Epidemiology, IRCCS Istituto Centro San Giovanni di Dio Fatebenefratelli, Brescia, Italy
| | - Henryk Barthel
- Department of Nuclear Medicine, University of Leipzig, Leipzig, Germany
| | - Oskar Hansson
- Memory Clinic, Skåne University Hopsital, Malmö, Sweden
- Clinical Memory Research Unit, Department of Clinical Sciences Malmö, Lund University, Lund, Sweden
| | - Agneta Nordberg
- Division of Clinical Geriatrics, Center for Alzheimer Research, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden
| | - Rik Ossenkoppele
- Clinical Memory Research Unit, Department of Clinical Sciences Malmö, Lund University, Lund, Sweden
- Alzheimer Center Amsterdam, Department of Neurology, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam UMC, Amsterdam, Netherlands
| | - Osama Sabri
- Department of Nuclear Medicine, University of Leipzig, Leipzig, Germany
| | - B Frisoni G Giovanni
- NIMTlab, Neuroimaging and Innovative Molecular Tracers Laboratory, University of Geneva, Geneva, Switzerland
- Memory Center - Department of Rehabilitation and Geriatrics, Geneva University Hospitals, Geneva, Switzerland
| | - Valentina Garibotto
- NIMTlab, Neuroimaging and Innovative Molecular Tracers Laboratory, University of Geneva, Geneva, Switzerland
- Nuclear Medicine and Molecular Imaging Division, Diagnostic Department, Geneva University Hospitals, Genève, Switzerland
| | - Alexander Drzezga
- Department of Nuclear Medicine, University Hospital Cologne, Cologne, Germany
- German Center for Neurodegenerative Disorders (DZNE), Rostock/Greifswald, Rostock, Germany
- German Center for Neurodegenerative Disorders (DZNE), Bonn/Cologne, Germany
- Molecular Organization of the Brain, Institute for Neuroscience and Medicine (INM-2), Jülich, Germany
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Goodheart AE, Locascio JJ, Samore WR, Collins JA, Brickhouse M, Schultz A, Touroutoglou A, Johnson KA, Frosch MP, Growdon JH, Dickerson BC, Gomperts SN. 18F-AV-1451 positron emission tomography in neuropathological substrates of corticobasal syndrome. Brain 2021; 144:266-277. [PMID: 33578418 DOI: 10.1093/brain/awaa383] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Revised: 08/18/2020] [Accepted: 08/24/2020] [Indexed: 11/12/2022] Open
Abstract
Multiple neuropathological processes can manifest in life as a corticobasal syndrome. We sought to relate retention of the tau-PET tracer 18F-AV-1451 and structural magnetic resonance measures of regional atrophy to clinical features in clinically diagnosed and neuropathologically confirmed cases of corticobasal syndrome and to determine whether these vary with the underlying neuropathological changes. In this observational, cross-sectional study, 11 subjects (eight female and three male, median age 72 years) with corticobasal syndrome underwent structural MRI, tau-PET with 18F-AV-1451, amyloid-PET with 11C-Pittsburgh compound B, detailed clinical examinations and neuropsychological testing. Of the 11, three had evidence of high amyloid burden consistent with Alzheimer's disease while eight did not. Neuropathological evaluations were acquired in six cases. Mixed effects general linear models were used to compare 18F-AV-1451 retention and atrophy in amyloid-negative corticobasal syndrome cases to 32 age-matched healthy control subjects and to relate cortical and subcortical 18F-AV-1451 retention and atrophy to clinical features. Subjects without amyloid, including three with pathologically confirmed corticobasal degeneration, showed greater regional 18F-AV-1451 retention and associated regional atrophy in areas commonly associated with corticobasal degeneration pathology than healthy control subjects [retention was higher compared to healthy controls (P = 0.0011), driven especially by the precentral gyrus (P = 0.011) and pallidum (P < 0.0001), and greater atrophy was seen in subjects compared to control subjects (P = 0.0004)]. Both 18F-AV-1451 retention and atrophy were greater in the clinically more affected hemisphere [on average, retention was 0.173 standardized uptake value ratio units higher on the more affected side (95% confidence interval, CI 0.11-0.24, P < 0.0001), and volume was 0.719 lower on the more affected side (95% CI 0.35-1.08, P = 0.0001)]. 18F-AV-1451 retention was greater in subcortical than in cortical regions, P < 0.0001. In contrast to these findings, subjects with amyloid-positive corticobasal syndrome, including two neuropathologically confirmed cases of Alzheimer's disease, demonstrated greater and more widespread 18F-AV-1451 retention and regional atrophy than observed in the amyloid-negative cases. There was thalamic 18F-AV-1451 retention but minimal cortical and basal ganglia uptake in a single corticobasal syndrome subject without neuropathological evidence of tau pathology, likely representing non-specific signal. Asymmetric cortical and basal ganglia 18F-AV-1451 retention consonant with the clinical manifestations characterize corticobasal syndrome due to corticobasal degeneration, whereas the cortical retention in cases associated with Alzheimer's disease is greater and more diffuse.
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Affiliation(s)
- Anna E Goodheart
- Department of Neurology, Massachusetts General Hospital, Charlestown, MA, USA.,Massachusetts Alzheimer's Disease Research Center, Massachusetts General Hospital, Boston, MA, USA
| | - Joseph J Locascio
- Department of Neurology, Massachusetts General Hospital, Charlestown, MA, USA.,Massachusetts Alzheimer's Disease Research Center, Massachusetts General Hospital, Boston, MA, USA
| | - Wesley R Samore
- Department of Pathology, Massachusetts General Hospital, Boston, MA, USA
| | - Jessica A Collins
- Department of Neurology, Massachusetts General Hospital, Charlestown, MA, USA.,Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA
| | - Michael Brickhouse
- Department of Neurology, Massachusetts General Hospital, Charlestown, MA, USA.,Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA
| | - Aaron Schultz
- Massachusetts Alzheimer's Disease Research Center, Massachusetts General Hospital, Boston, MA, USA.,Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA.,Department of Radiology, Massachusetts General Hospital, Boston, MA, USA
| | - Alexandra Touroutoglou
- Department of Neurology, Massachusetts General Hospital, Charlestown, MA, USA.,Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA
| | - Keith A Johnson
- Department of Neurology, Massachusetts General Hospital, Charlestown, MA, USA.,Massachusetts Alzheimer's Disease Research Center, Massachusetts General Hospital, Boston, MA, USA.,Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA.,Department of Radiology, Massachusetts General Hospital, Boston, MA, USA
| | - Matthew P Frosch
- Massachusetts Alzheimer's Disease Research Center, Massachusetts General Hospital, Boston, MA, USA.,Department of Pathology, Massachusetts General Hospital, Boston, MA, USA
| | - John H Growdon
- Department of Neurology, Massachusetts General Hospital, Charlestown, MA, USA.,Massachusetts Alzheimer's Disease Research Center, Massachusetts General Hospital, Boston, MA, USA
| | - Bradford C Dickerson
- Department of Neurology, Massachusetts General Hospital, Charlestown, MA, USA.,Massachusetts Alzheimer's Disease Research Center, Massachusetts General Hospital, Boston, MA, USA.,Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA
| | - Stephen N Gomperts
- Department of Neurology, Massachusetts General Hospital, Charlestown, MA, USA.,Massachusetts Alzheimer's Disease Research Center, Massachusetts General Hospital, Boston, MA, USA
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Hansen AK, Parbo P, Ismail R, Østergaard K, Brooks DJ, Borghammer P. Tau Tangles in Parkinson's Disease: A 2-Year Follow-Up Flortaucipir PET Study. JOURNAL OF PARKINSONS DISEASE 2021; 10:161-171. [PMID: 31815700 DOI: 10.3233/jpd-191774] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
BACKGROUND Flortaucipir PET, a marker of tau tangles, has shown lower than expected cortical uptake in Parkinson's disease (PD), than would be predicted from neuropathologic estimates of Alzheimer's disease co-pathology. Instead, the most characteristic finding of flortaucipir imaging in PD is decreased uptake in the substantia nigra, reflecting reduction in its "off-target" binding to neuromelanin. We have previously reported these observations in cross-sectional studies. OBJECTIVE Here, we present two-year follow-up data of cortical and nigral flortaucipir uptake in PD patients. METHODS Seventeen PD patients received repeat flortaucipir PET two years after baseline. We interrogated vertex-based group-wise cortical tracer binding (SUVRs) with a cerebellar reference using the general linear model while mean substantia nigra SUVRs were compared with volumes of interest group comparisons and voxel-wise group analyses using ANOVA. Finally, we performed linear regressions of tau load with changes in MoCA and UPDRS motor scores. RESULTS We found no significant changes in substantia nigra or cortex flortaucipir uptake in Parkinson's disease patients over two years and no association with changes in cognitive symptoms. Signal reduction in the medial substantia nigra trended towards an association with worsening of motor symptoms. CONCLUSION No significant increase in tau tangles occurred after a two-year follow-up of Parkinson's disease patients using flortaucipir PET.
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Affiliation(s)
- Allan K Hansen
- Department of Nuclear Medicine and PET, Aarhus University Hospital, Aarhus, Denmark
| | - Peter Parbo
- Department of Nuclear Medicine and PET, Aarhus University Hospital, Aarhus, Denmark
| | - Rola Ismail
- PET-Centre, Institute of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | | | - David J Brooks
- PET-Centre, Institute of Clinical Medicine, Aarhus University, Aarhus, Denmark.,Institute of Neuroscience, Newcastle University, Newcastle, UK.,Division of Brain Sciences, Imperial College London, London, UK
| | - Per Borghammer
- Department of Nuclear Medicine and PET, Aarhus University Hospital, Aarhus, Denmark.,PET-Centre, Institute of Clinical Medicine, Aarhus University, Aarhus, Denmark
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Campese N, Palermo G, Del Gamba C, Beatino MF, Galgani A, Belli E, Del Prete E, Della Vecchia A, Vergallo A, Siciliano G, Ceravolo R, Hampel H, Baldacci F. Progress regarding the context-of-use of tau as biomarker of Alzheimer's disease and other neurodegenerative diseases. Expert Rev Proteomics 2021; 18:27-48. [PMID: 33545008 DOI: 10.1080/14789450.2021.1886929] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Introduction: Tau protein misfolding and accumulation in toxic species is a critical pathophysiological process of Alzheimer's disease (AD) and other neurodegenerative disorders (NDDs). Tau biomarkers, namely cerebrospinal fluid (CSF) total-tau (t-tau), 181-phosphorylated tau (p-tau), and tau-PET tracers, have been recently embedded in the diagnostic criteria for AD. Nevertheless, the role of tau as a diagnostic and prognostic biomarker for other NDDs remains controversial.Areas covered: We performed a systematical PubMed-based review of the most recent advances in tau-related biomarkers for NDDs. We focused on papers published from 2015 to 2020 assessing the diagnostic or prognostic value of each biomarker.Expert opinion: The assessment of tau biomarkers in alternative easily accessible matrices, through the development of ultrasensitive techniques, represents the most significant perspective for AD-biomarker research. In NDDs, novel tau isoforms (e.g. p-tau217) or proteolytic fragments (e.g. N-terminal fragments) may represent candidate diagnostic and prognostic biomarkers and may help monitoring disease progression. Protein misfolding amplification assays, allowing the identification of different tau strains (e.g. 3 R- vs. 4 R-tau) in CSF, may constitute a breakthrough for the in vivo stratification of NDDs. Tau-PET may help tracking the spatial-temporal evolution of tau pathophysiology in AD but its application outside the AD-spectrum deserves further studies.
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Affiliation(s)
- Nicole Campese
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Giovanni Palermo
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Claudia Del Gamba
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | | | - Alessandro Galgani
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Elisabetta Belli
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Eleonora Del Prete
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | | | - Andrea Vergallo
- GRC N° 21, Alzheimer Precision Medicine (APM), AP-HP, Pitié-Salpêtrière Hospital, Boulevard De L'hôpital, Sorbonne University, Paris, France
| | - Gabriele Siciliano
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Roberto Ceravolo
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Harald Hampel
- GRC N° 21, Alzheimer Precision Medicine (APM), AP-HP, Pitié-Salpêtrière Hospital, Boulevard De L'hôpital, Sorbonne University, Paris, France
| | - Filippo Baldacci
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy.,GRC N° 21, Alzheimer Precision Medicine (APM), AP-HP, Pitié-Salpêtrière Hospital, Boulevard De L'hôpital, Sorbonne University, Paris, France
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40
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Frontal Variant of Alzheimer Disease Differentiated From Frontotemporal Dementia Using in Vivo Amyloid and Tau Imaging. Cogn Behav Neurol 2021; 33:288-293. [PMID: 33264158 DOI: 10.1097/wnn.0000000000000251] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The frontal variant of Alzheimer disease (fvAD) is characterized by behavioral and/or dysexecutive impairments that can resemble those of behavioral-variant frontotemporal dementia (bvFTD). This overlap, in addition to the lack of consensus clinical criteria for fvAD, complicates its identification. We provide the first case report of fvAD differentiated in vivo from bvFTD using amyloid-beta and tau PET imaging. The patient, a right-handed woman, presented with forgetfulness at age 60. Cognitive testing at that time revealed mild impairments in memory, attention, and executive functions. Three years later, her family reported that she was displaying socially inappropriate behaviors, inertia, diminished social interest, and altered food preferences-the sum of which met the criteria for possible bvFTD. PET using an amyloid-beta tracer (F-AZD4694) identified diffuse amyloid plaques across the cerebral cortex. PET using a tau tracer specific for neurofibrillary tangles (F-MK6240) identified substantial tau pathology in the brain's frontal lobes. Together with the clinical findings, these images supported the diagnosis of fvAD rather than bvFTD. Considering past and emerging evidence that tau topography in Alzheimer disease (AD) matches the clinical features of AD, we discuss the potential utility of in vivo tau imaging using F-MK6240 for identifying fvAD.
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41
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Frey KA, Bohnen NILJ. Molecular Imaging of Neurodegenerative Parkinsonism. PET Clin 2021; 16:261-272. [PMID: 33589385 DOI: 10.1016/j.cpet.2020.12.002] [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] [Indexed: 11/18/2022]
Abstract
Advances in molecular PET imaging of neurodegenerative parkinsonism are reviewed with focus on neuropharmacologic radiotracers depicting terminals of selectively vulnerable neurons in these conditions. Degeneration and losses of dopamine, norepinephrine, serotonin, and acetylcholine imaging markers thus far do not differentiate among the parkinsonian conditions. Recent studies performed with [18F]fluorodeoxyglucose PET are limited by the need for automated image analysis tools and by lack of routine coverage for this imaging indication in the United States. Ongoing research engages use of novel molecular modeling and in silico methods for design of imaging ligands targeting these specific proteinopathies.
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Affiliation(s)
- Kirk A Frey
- Department of Radiology (Nuclear Medicine and Molecular Imaging), University of Michigan, 1500 East Medical Center Drive, Room B1-G505 UH, Ann Arbor, MI 48109-5028, USA; Department of Neurology, University of Michigan, 1500 East Medical Center Drive, Room B1-G505 UH, Ann Arbor, MI 48109-5028, USA.
| | - Nicolaas I L J Bohnen
- Department of Radiology (Nuclear Medicine and Molecular Imaging), University of Michigan, 24 Frank Lloyd Wright Drive, Box 362, Ann Arbor, MI 48105, USA; Department of Neurology, University of Michigan, 24 Frank Lloyd Wright Drive, Box 362, Ann Arbor, MI 48105, USA; Ann Arbor Veterans Administration Medical Center, Ann Arbor, MI, USA
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42
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Fang H, Wu M, Ji W, Wang L, Chen Y, Chen D, Yang N, Wu Q, Yu C, Liu J, Liu J, Bai H, Peng B, Huang X, Yu HD, Li L. Simultaneously Detecting Monoamine Oxidase A and B in Disease Cell/Tissue Samples Using Paper-Based Devices. ACS APPLIED BIO MATERIALS 2021; 4:1395-1402. [PMID: 35014490 DOI: 10.1021/acsabm.0c01288] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
As enzymes in the outer membrane of the mitochondrion, monoamine oxidases (MAOs) can catalyze the oxidative deamination of monoamines in the human body. According to different substrates, MAOs can be divided into MAO-A and MAO-B. The imbalance of the MAO-A is associated with neurological degeneration, while excess MAO-B activity is closely connected with Parkinson's disease (PD) and Alzheimer's disease (AD); therefore, detection of MAOs is of great significance for the diagnosis and treatment of these diseases. This work reports the multiplexed detection of MAO-A and MAO-B using paper-based devices based on chemiluminescence (CL). The detection limits were 5.01 pg/mL for MAO-A and 8.50 pg/mL for MAO-B in human serum. In addition, we used paper-based devices to detect MAOs in human cells and tissue samples and found that the results of paper-based detection and Western blotting (WB) showed the same trend. While only one antibody can be incubated on the same membrane by WB, multiple antibodies incubated on the same paper enabled simultaneous detection of MAO-A and MAO-B by paper-based devices. The paper-based assay could be used for preliminary early screening of clinical samples for MAOs and can be extended as an alternative to WB for multiplexed detection of various proteins in disease cell or tissue samples.
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Affiliation(s)
- Haixiao Fang
- Key Laboratory of Flexible Electronics (KLOFE) and Institute of Advanced Materials (IAM), Nanjing Tech University (NanjingTech), 30 South Puzhu Road, Nanjing 211816, P. R. China
| | - Meirong Wu
- Key Laboratory of Flexible Electronics (KLOFE) and Institute of Advanced Materials (IAM), Nanjing Tech University (NanjingTech), 30 South Puzhu Road, Nanjing 211816, P. R. China
| | - Wenhui Ji
- Key Laboratory of Flexible Electronics (KLOFE) and Institute of Advanced Materials (IAM), Nanjing Tech University (NanjingTech), 30 South Puzhu Road, Nanjing 211816, P. R. China
| | - Limin Wang
- Frontiers Science Center for Flexible Electronics, Xi'an Institute of Flexible Electronics (IFE) and Xi'an Institute of Biomedical Materials & Engineering, Northwestern Polytechnical University, 127 West Youyi Road, Xi'an 710072, P. R. China
| | - Yipei Chen
- Frontiers Science Center for Flexible Electronics, Xi'an Institute of Flexible Electronics (IFE) and Xi'an Institute of Biomedical Materials & Engineering, Northwestern Polytechnical University, 127 West Youyi Road, Xi'an 710072, P. R. China
| | - Ding Chen
- Key Laboratory of Flexible Electronics (KLOFE) and Institute of Advanced Materials (IAM), Nanjing Tech University (NanjingTech), 30 South Puzhu Road, Nanjing 211816, P. R. China
| | - Naidi Yang
- Key Laboratory of Flexible Electronics (KLOFE) and Institute of Advanced Materials (IAM), Nanjing Tech University (NanjingTech), 30 South Puzhu Road, Nanjing 211816, P. R. China
| | - Qiong Wu
- Key Laboratory of Flexible Electronics (KLOFE) and Institute of Advanced Materials (IAM), Nanjing Tech University (NanjingTech), 30 South Puzhu Road, Nanjing 211816, P. R. China
| | - Changmin Yu
- Key Laboratory of Flexible Electronics (KLOFE) and Institute of Advanced Materials (IAM), Nanjing Tech University (NanjingTech), 30 South Puzhu Road, Nanjing 211816, P. R. China
| | - Jie Liu
- Key Laboratory of Flexible Electronics (KLOFE) and Institute of Advanced Materials (IAM), Nanjing Tech University (NanjingTech), 30 South Puzhu Road, Nanjing 211816, P. R. China
| | - Jinhua Liu
- Key Laboratory of Flexible Electronics (KLOFE) and Institute of Advanced Materials (IAM), Nanjing Tech University (NanjingTech), 30 South Puzhu Road, Nanjing 211816, P. R. China
| | - Hua Bai
- Frontiers Science Center for Flexible Electronics, Xi'an Institute of Flexible Electronics (IFE) and Xi'an Institute of Biomedical Materials & Engineering, Northwestern Polytechnical University, 127 West Youyi Road, Xi'an 710072, P. R. China
| | - Bo Peng
- Frontiers Science Center for Flexible Electronics, Xi'an Institute of Flexible Electronics (IFE) and Xi'an Institute of Biomedical Materials & Engineering, Northwestern Polytechnical University, 127 West Youyi Road, Xi'an 710072, P. R. China
| | - Xiao Huang
- Key Laboratory of Flexible Electronics (KLOFE) and Institute of Advanced Materials (IAM), Nanjing Tech University (NanjingTech), 30 South Puzhu Road, Nanjing 211816, P. R. China
| | - Hai-Dong Yu
- Key Laboratory of Flexible Electronics (KLOFE) and Institute of Advanced Materials (IAM), Nanjing Tech University (NanjingTech), 30 South Puzhu Road, Nanjing 211816, P. R. China.,Frontiers Science Center for Flexible Electronics, Xi'an Institute of Flexible Electronics (IFE) and Xi'an Institute of Biomedical Materials & Engineering, Northwestern Polytechnical University, 127 West Youyi Road, Xi'an 710072, P. R. China
| | - Lin Li
- Key Laboratory of Flexible Electronics (KLOFE) and Institute of Advanced Materials (IAM), Nanjing Tech University (NanjingTech), 30 South Puzhu Road, Nanjing 211816, P. R. China
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Jie CVML, Treyer V, Schibli R, Mu L. Tauvid™: The First FDA-Approved PET Tracer for Imaging Tau Pathology in Alzheimer's Disease. Pharmaceuticals (Basel) 2021; 14:ph14020110. [PMID: 33573211 PMCID: PMC7911942 DOI: 10.3390/ph14020110] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Revised: 01/25/2021] [Accepted: 01/27/2021] [Indexed: 12/03/2022] Open
Abstract
Tauvid has been approved by the U.S. Food and Drug Administration (FDA) in 2020 for positron emission tomography (PET) imaging of adult patients with cognitive impairments undergoing evaluation for Alzheimer’s disease (AD) based on tau pathology. Abnormal aggregation of tau proteins is one of the main pathologies present in AD and is receiving increasing attention as a diagnostic and therapeutic target. In this review, we summarised the production and quality control of Tauvid, its clinical application, pharmacology and pharmacokinetics, as well as its limitation due to off-target binding. Moreover, a brief overview on the second-generation of Tau PET tracers is provided. The approval of Tauvid marks a step forward in the field of AD research and opens up opportunities for second-generation tau tracers to advance tau PET imaging in the clinic.
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Affiliation(s)
- Caitlin V. M. L. Jie
- Center for Radiopharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Zürich, 8093 Zurich, Switzerland; (C.V.M.L.J.); (R.S.)
| | - Valerie Treyer
- Department of Nuclear Medicine, University Hospital Zurich, 8091 Zurich, Switzerland;
| | - Roger Schibli
- Center for Radiopharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Zürich, 8093 Zurich, Switzerland; (C.V.M.L.J.); (R.S.)
| | - Linjing Mu
- Center for Radiopharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Zürich, 8093 Zurich, Switzerland; (C.V.M.L.J.); (R.S.)
- Department of Nuclear Medicine, University Hospital Zurich, 8091 Zurich, Switzerland;
- Correspondence:
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Whittington A, Gunn RN. Tau IQ: A Canonical Image Based Algorithm to Quantify Tau PET Scans. J Nucl Med 2021; 62:1292-1300. [PMID: 33517326 DOI: 10.2967/jnumed.120.258962] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Accepted: 01/13/2021] [Indexed: 12/20/2022] Open
Abstract
Recently, AmyloidIQ was introduced as a new canonical image-based algorithm to quantify amyloid PET scans and demonstrated increased power over traditional SUV ratio (SUVR) approaches when assessed in cross-sectional and longitudinal analyses. We build further on this mathematical framework to develop a TauIQ algorithm for the quantitative analysis of the more complex spatial distribution displayed by tau PET radiotracers. Methods: Cross-sectional (n = 615) and longitudinal (n = 149) 18F-flortaucipir data were obtained from the Alzheimer's Disease Neuroimaging Initiative along with necessary adjunct amyloid PET and T1-weighted structural MRI data. A subset of these data were used to derive a chronological tau dataset, using AmyloidIQ analysis of associated amyloid PET data to calculate the subject's temporal position in the canonical AD disease process, from which canonical images for the nonspecific and specific binding components of 18F-flortaucipir in AD were calculated. These 2 canonical images were incorporated into the TauIQ algorithm that enables the quantification of both global and local tau outcome measures using an image-based regression and statistical parametric analysis of the initial residual image. Performance of the TauIQ algorithm was compared with SUVR approaches for cross-sectional analyses, longitudinal analyses, and correlation with clinical measures (Alzheimer Disease Assessment Scale-Cognitive Subscale [ADAS-Cog], Clinical Dementia Rating scale-sum of boxes [CDR-SB], and Mini-Mental State Examination [MMSE]). Results: TauIQ successfully calculated global tau load (TauL) in all 791 scans analyzed (range, -3.5% to 185.2%; mean ± SD, 23% ± 20.5%) with a nonzero additional local tau component being required in 31% of all scans (cognitively normal [CN], 22%; mild cognitive impairment [MCI], 35%; dementia, 72%). TauIQ was compared with the best SUVR approach in the cross-sectional analysis (TauL increase in effect size: CN- vs. CN+, +45%; CN- vs. MCI+, -5.6%; CN- vs. dementia+, +2.3%) (+/- indicates amyloid-positive or -negative) and correlation with clinical scores (TauL increase in r 2: CDR-SB+, 7%; MMSE+, 38%; ADAS-Cog+, 0%). TauIQ substantially outperformed SUVR approaches in the longitudinal analysis (TauIQ increase in power: CN+, >3.2-fold; MCI+, >2.2-fold; dementia+, >2.9-fold). Conclusion: TauL as calculated by TauIQ provides a superior approach for the quantification of tau PET data. In particular, it provides a substantial improvement in power for longitudinal analyses and the early detection of tau deposition and thus should have significant value for clinical imaging trials in AD that are investigating the attenuation of tau deposition with novel therapies.
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Affiliation(s)
| | - Roger N Gunn
- Invicro LLC, London, United Kingdom; and.,Department of Brain Sciences, Imperial College London, Hammersmith Hospital Campus, London, United Kingdom
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Abstract
This article presents an overview of imaging agents for PET that have been applied for research and diagnostic purposes in patients affected by dementia. Classified by the target which the agents visualize, seven groups of tracers can be distinguished, namely radiopharmaceuticals for: (1) Misfolded proteins (ß-amyloid, tau, α-synuclein), (2) Neuroinflammation (overexpression of translocator protein), (3) Elements of the cholinergic system, (4) Elements of monoamine neurotransmitter systems, (5) Synaptic density, (6) Cerebral energy metabolism (glucose transport/ hexokinase), and (7) Various other proteins. This last category contains proteins involved in mechanisms underlying neuroinflammation or cognitive impairment, which may also be potential therapeutic targets. Many receptors belong to this category: AMPA, cannabinoid, colony stimulating factor 1, metabotropic glutamate receptor 1 and 5 (mGluR1, mGluR5), opioid (kappa, mu), purinergic (P2X7, P2Y12), sigma-1, sigma-2, receptor for advanced glycation endproducts, and triggering receptor expressed on myeloid cells-1, besides several enzymes: cyclooxygenase-1 and 2 (COX-1, COX-2), phosphodiesterase-5 and 10 (PDE5, PDE10), and tropomyosin receptor kinase. Significant advances in neuroimaging have been made in the last 15 years. The use of 2-[18F]-fluoro-2-deoxy-D-glucose (FDG) for quantification of regional cerebral glucose metabolism is well-established. Three tracers for ß-amyloid plaques have been approved by the Food and Drug Administration and European Medicines Agency. Several tracers for tau neurofibrillary tangles are already applied in clinical research. Since many novel agents are in the preclinical or experimental stage of development, further advances in nuclear medicine imaging can be expected in the near future. PET studies with established tracers and tracers for novel targets may result in early diagnosis and better classification of neurodegenerative disorders and in accurate monitoring of therapy trials which involve these targets. PET data have prognostic value and may be used to assess the response of the human brain to interventions, or to select the appropriate treatment strategy for an individual patient.
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Affiliation(s)
- Aren van Waarde
- University of Groningen, University Medical Center Groningen, Department of Nuclear Medicine and Molecular Imaging, Groningen, the Netherlands.
| | - Sofia Marcolini
- University of Groningen, University Medical Center Groningen, Department of Neurology, Groningen, the Netherlands
| | - Peter Paul de Deyn
- University of Groningen, University Medical Center Groningen, Department of Neurology, Groningen, the Netherlands; University of Antwerp, Born-Bunge Institute, Neurochemistry and Behavior, Campus Drie Eiken, Wilrijk, Belgium
| | - Rudi A J O Dierckx
- University of Groningen, University Medical Center Groningen, Department of Nuclear Medicine and Molecular Imaging, Groningen, the Netherlands; Ghent University, Ghent, Belgium
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Frey KA. Molecular Imaging of Extrapyramidal Movement Disorders With Dementia: The 4R Tauopathies. Semin Nucl Med 2021; 51:275-285. [PMID: 33431202 DOI: 10.1053/j.semnuclmed.2020.12.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Two pathologically distinct neurodegenerative conditions, progressive supranuclear palsy and corticobasal degeneration, share in common deposits of tau proteins that differ both molecularly and ultrastructurally from the common tau deposits diagnostic of Alzheimer disease. The proteinopathy in these disorders is characterized by fibrillary aggregates of 4R tau proteins. The clinical presentations of progressive supranuclear palsy and of corticobasal degeneration are often confused with more common disorders such as Parkinson disease or subtypes of frontotemporal lobar degeneration. Neither of these 4R tau disorders has effective therapy, and while there are emerging molecular imaging approaches to identify patients earlier in the course of disease, there are as yet no reliably sensitive and specific approaches to diagnoses in life. In this review, aspects of the clinical syndromes, neuropathology, and molecular biomarker imaging studies applicable to progressive supranuclear palsy and to corticobasal degeneration will be presented. Future development of more accurate molecular imaging approaches is proposed.
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Affiliation(s)
- Kirk A Frey
- Division of Nuclear Medicine and Molecular Imaging, Department of Radiology, The University of Michigan Health System, Ann Arbor, MI.
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Drzezga A, Bischof GN, Giehl K, van Eimeren T. PET and SPECT Imaging of Neurodegenerative Diseases. Mol Imaging 2021. [DOI: 10.1016/b978-0-12-816386-3.00085-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
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Chiotis K, Savitcheva I, Poulakis K, Saint-Aubert L, Wall A, Antoni G, Nordberg A. [ 18F]THK5317 imaging as a tool for predicting prospective cognitive decline in Alzheimer's disease. Mol Psychiatry 2021; 26:5875-5887. [PMID: 32616831 PMCID: PMC8758479 DOI: 10.1038/s41380-020-0815-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2019] [Revised: 05/09/2020] [Accepted: 06/08/2020] [Indexed: 11/09/2022]
Abstract
Cross-sectional studies have indicated potential for positron emission tomography (PET) in imaging tau pathology in Alzheimer's disease (AD); however, its prognostic utility remains unproven. In a longitudinal, multi-modal, prognostic study of cognitive decline, 20 patients with a clinical biomarker-based diagnosis in the AD spectrum (mild cognitive impairment or dementia and a positive amyloid-beta PET scan) were recruited from the Cognitive Clinic at Karolinska University Hospital. The participants underwent baseline neuropsychological assessment, PET imaging with [18F]THK5317, [11C]PIB and [18F]FDG, magnetic resonance imaging, and in a subgroup cerebrospinal fluid (CSF) sampling, with clinical follow-up after a median 48 months (interquartile range = 32:56). In total, 11 patients declined cognitively over time, while 9 remained cognitively stable. The accuracy of baseline [18F]THK5317 binding in temporal areas was excellent at predicting future cognitive decline (area under the receiver operating curve 0.84-1.00) and the biomarker levels were strongly associated with the rate of cognitive decline (β estimate -33.67 to -31.02, p < 0.05). The predictive accuracy of the other baseline biomarkers was poor (area under the receiver operating curve 0.58-0.77) and their levels were not associated with the rate of cognitive decline (β estimate -4.64 to 15.78, p > 0.05). Baseline [18F]THK5317 binding and CSF tau levels were more strongly associated with the MMSE score at follow-up than at baseline (p < 0.05). These findings support a temporal dissociation between tau deposition and cognitive impairment, and suggest that [18F]THK5317 predicts future cognitive decline better than other biomarkers. The use of imaging markers for tau pathology could prove useful for clinical prognostic assessment and screening before inclusion in relevant clinical trials.
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Affiliation(s)
- Konstantinos Chiotis
- grid.4714.60000 0004 1937 0626Nordberg Translational Molecular Imaging Lab, Division of Clinical Geriatrics, Center for Alzheimer Research, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden ,grid.24381.3c0000 0000 9241 5705Theme Neurology, Karolinska University Hospital, Stockholm, Sweden
| | - Irina Savitcheva
- grid.24381.3c0000 0000 9241 5705Medical Radiation Physics and Nuclear Medicine, Karolinska University Hospital, Stockholm, Sweden
| | - Konstantinos Poulakis
- grid.4714.60000 0004 1937 0626Westman neuroimaging group, Division of Clinical Geriatrics, Center for Alzheimer Research, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden
| | - Laure Saint-Aubert
- grid.4714.60000 0004 1937 0626Nordberg Translational Molecular Imaging Lab, Division of Clinical Geriatrics, Center for Alzheimer Research, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden ,grid.15781.3a0000 0001 0723 035XToulouse NeuroImaging Center, University of Toulouse, Inserm, UPS, Toulouse, France
| | - Anders Wall
- grid.8993.b0000 0004 1936 9457Section for Nuclear Medicine and PET, Department of Surgical Sciences, Uppsala University, Uppsala, Sweden
| | - Gunnar Antoni
- grid.8993.b0000 0004 1936 9457Department of Medicinal Chemistry, Uppsala University, Uppsala, Sweden
| | - Agneta Nordberg
- Nordberg Translational Molecular Imaging Lab, Division of Clinical Geriatrics, Center for Alzheimer Research, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden. .,Theme Aging, Karolinska University Hospital, Stockholm, Sweden.
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Abstract
Pathological accumulated misfolded tau underlies various neurodegenerative diseases and associated clinical syndromes. To diagnose those diseases reliable before death or even at early stages, many different tau-specific radiotracers have been developed in the last decade to be used with positron-emission-tomography. In contrast to amyloid-β imaging, different isoforms of tau exist further complicating radiotracer development. First-generation radiotracers like [11C]PBB3, [18F]AV1451 and [18F]THK5351 have been extensively investigated in vitro and in vivo. In Alzheimer's disease (AD), high specific binding could be detected, and evidence of clinical applicability recently led to clinical approval of [18F]flortaucipir ([18F]AV1451) by the FDA. Nevertheless, absent or minor binding to non-AD tau isoforms and high off-target binding to non-tau brain structures limit the diagnostic applicability especially in non-AD tauopathies demanding further tracer development. In vitro assays and autoradiography results of next-generation radiotracers [18F]MK-6240, [18F]RO-948, [18F]PM-PBB3, [18F]GTP-1 and [18F]PI-2620 clearly indicate less off-target binding and high specific binding to tau neurofibrils. First in human studies have been conducted with promising results for all tracers in AD patients, and also some positive experience in non-AD tauopathies. Overall, larger scaled autoradiography and human studies are needed to further evaluate the most promising candidates and support future clinical approval.
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Affiliation(s)
- Leonie Beyer
- Department of Nuclear Medicine, University Hospital of Munich, Munich, Germany.
| | - Matthias Brendel
- Department of Nuclear Medicine, University Hospital of Munich, Munich, Germany; Munich Cluster for Systems Neurology (SyNergy), Munich, Germany.
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Novel PET Biomarkers to Disentangle Molecular Pathways across Age-Related Neurodegenerative Diseases. Cells 2020; 9:cells9122581. [PMID: 33276490 PMCID: PMC7761606 DOI: 10.3390/cells9122581] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 11/25/2020] [Accepted: 11/28/2020] [Indexed: 12/11/2022] Open
Abstract
There is a need to disentangle the etiological puzzle of age-related neurodegenerative diseases, whose clinical phenotypes arise from known, and as yet unknown, pathways that can act distinctly or in concert. Enhanced sub-phenotyping and the identification of in vivo biomarker-driven signature profiles could improve the stratification of patients into clinical trials and, potentially, help to drive the treatment landscape towards the precision medicine paradigm. The rapidly growing field of neuroimaging offers valuable tools to investigate disease pathophysiology and molecular pathways in humans, with the potential to capture the whole disease course starting from preclinical stages. Positron emission tomography (PET) combines the advantages of a versatile imaging technique with the ability to quantify, to nanomolar sensitivity, molecular targets in vivo. This review will discuss current research and available imaging biomarkers evaluating dysregulation of the main molecular pathways across age-related neurodegenerative diseases. The molecular pathways focused on in this review involve mitochondrial dysfunction and energy dysregulation; neuroinflammation; protein misfolding; aggregation and the concepts of pathobiology, synaptic dysfunction, neurotransmitter dysregulation and dysfunction of the glymphatic system. The use of PET imaging to dissect these molecular pathways and the potential to aid sub-phenotyping will be discussed, with a focus on novel PET biomarkers.
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