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Bruno D, Jauregi-Zinkunegi A, Betthauser T, Carlsson C, Bendlin BB, Okonkwo O, Chin NA, Asthana S, Langhough RE, Johnson SC, Mueller KD. Story recall performance and AT classification via positron emission tomography: A comparison of logical memory and Craft Story 21. J Neurol Sci 2024; 464:123148. [PMID: 39096836 DOI: 10.1016/j.jns.2024.123148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2024] [Revised: 07/05/2024] [Accepted: 07/20/2024] [Indexed: 08/05/2024]
Abstract
BACKGROUND Early detection of Alzheimer's disease (AD) is one of the critical components of the global response to the growing dementia crisis. Analysis of serial position performance in story recall tests has yielded sensitive metrics for the prediction of AD at low cost. In this study, we examined whether serial position markers in two story recall tests (the logical memory test, LMT, and the Craft Story 21 test, CST) were sensitive to cross-sectional biomarker-based assessment of in vivo neuropathology. METHODS Participants were selected from the Wisconsin Registry of Alzheimer's Prevention (n = 288; WRAP) and the Alzheimer's Disease Research Center (n = 156; ADRC), both from the University of Wisconsin-Madison. Average age at PET was 68.9 (6.7) and 67.0 (8.0), respectively. Data included tau and PiB PET, and LMT for WRAP participants and CST for ADRC participants. Two sets of Bayesian analyses (logistic regressions and ANCOVAs) were conducted within each cohort, separately. RESULTS Results indicated that the A+T+ classification was best predicted, cross-sectionally, by the recency ratio (Rr), indexing how much of the end of the story was forgotten between initial learning and delayed assessment. Rr outperformed traditional scores and discriminated between A+T+ and A+T-/A-T-, in both cohorts. CONCLUSIONS Overall, this study confirms that serial position analysis of LMT and CST data, and particularly Rr as an index of recency loss, is a valuable tool for the identification of in vivo tau pathology in individuals free of dementia. Diagnostic considerations are discussed.
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Affiliation(s)
- Davide Bruno
- School of Psychology, Liverpool John Moores University, UK.
| | | | - Tobey Betthauser
- Wisconsin Alzheimer's Institute, School of Medicine and Public Health, University of Wisconsin - Madison, Madison, WI, USA; Wisconsin Alzheimer's Disease Research Center, School of Medicine and Public Health, University of Wisconsin - Madison, Madison, WI, USA
| | - Cynthia Carlsson
- Wisconsin Alzheimer's Institute, School of Medicine and Public Health, University of Wisconsin - Madison, Madison, WI, USA; Wisconsin Alzheimer's Disease Research Center, School of Medicine and Public Health, University of Wisconsin - Madison, Madison, WI, USA; Department of Medicine, University of Wisconsin-Madison, Madison, WI, USA; Geriatric Research Education and Clinical Center, William S. Middleton Veterans Hospital, Madison, WI, USA
| | - Barbara B Bendlin
- Wisconsin Alzheimer's Disease Research Center, School of Medicine and Public Health, University of Wisconsin - Madison, Madison, WI, USA; Department of Medicine, University of Wisconsin-Madison, Madison, WI, USA
| | - Ozioma Okonkwo
- Wisconsin Alzheimer's Disease Research Center, School of Medicine and Public Health, University of Wisconsin - Madison, Madison, WI, USA; Department of Medicine, University of Wisconsin-Madison, Madison, WI, USA
| | - Nathaniel A Chin
- Wisconsin Alzheimer's Institute, School of Medicine and Public Health, University of Wisconsin - Madison, Madison, WI, USA; Wisconsin Alzheimer's Disease Research Center, School of Medicine and Public Health, University of Wisconsin - Madison, Madison, WI, USA
| | - Sanjay Asthana
- Wisconsin Alzheimer's Institute, School of Medicine and Public Health, University of Wisconsin - Madison, Madison, WI, USA; Wisconsin Alzheimer's Disease Research Center, School of Medicine and Public Health, University of Wisconsin - Madison, Madison, WI, USA
| | - Rebecca E Langhough
- Wisconsin Alzheimer's Institute, School of Medicine and Public Health, University of Wisconsin - Madison, Madison, WI, USA; Wisconsin Alzheimer's Disease Research Center, School of Medicine and Public Health, University of Wisconsin - Madison, Madison, WI, USA
| | - Sterling C Johnson
- Wisconsin Alzheimer's Institute, School of Medicine and Public Health, University of Wisconsin - Madison, Madison, WI, USA; Wisconsin Alzheimer's Disease Research Center, School of Medicine and Public Health, University of Wisconsin - Madison, Madison, WI, USA; Department of Medicine, University of Wisconsin-Madison, Madison, WI, USA; Geriatric Research Education and Clinical Center, William S. Middleton Veterans Hospital, Madison, WI, USA
| | - Kimberly D Mueller
- Wisconsin Alzheimer's Institute, School of Medicine and Public Health, University of Wisconsin - Madison, Madison, WI, USA; Wisconsin Alzheimer's Disease Research Center, School of Medicine and Public Health, University of Wisconsin - Madison, Madison, WI, USA; Department of Communication Sciences and Disorders, University of Wisconsin - Madison, Madison, WI, USA
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2
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Sheng L, Bhalla R. Biomarkers and Target-Specific Small-Molecule Drugs in Alzheimer's Diagnostic and Therapeutic Research: From Amyloidosis to Tauopathy. Neurochem Res 2024; 49:2273-2302. [PMID: 38844706 PMCID: PMC11310295 DOI: 10.1007/s11064-024-04178-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2024] [Revised: 03/31/2024] [Accepted: 05/22/2024] [Indexed: 08/09/2024]
Abstract
Alzheimer's disease (AD) is the most common type of human dementia and is responsible for over 60% of diagnosed dementia cases worldwide. Abnormal deposition of β-amyloid and the accumulation of neurofibrillary tangles have been recognised as the two pathological hallmarks targeted by AD diagnostic imaging as well as therapeutics. With the progression of pathological studies, the two hallmarks and their related pathways have remained the focus of researchers who seek for AD diagnostic and therapeutic strategies in the past decades. In this work, we reviewed the development of the AD biomarkers and their corresponding target-specific small molecule drugs for both diagnostic and therapeutic applications, underlining their success, failure, and future possibilities.
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Affiliation(s)
- Li Sheng
- Centre for Advanced Imaging, The University of Queensland, St Lucia, Brisbane, QLD, 4072, Australia.
| | - Rajiv Bhalla
- Centre for Advanced Imaging, The University of Queensland, St Lucia, Brisbane, QLD, 4072, Australia
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3
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Sison SA, Paclibar CG, Liang C, Mukherjee J. Radioiodinated Tau Imaging Agent III Molecular Modeling, Synthesis, and Evaluation of a New Tau Imaging Agent, [ 125I]ISAS in Post-Mortem Human Alzheimer's Disease Brain. Molecules 2024; 29:3308. [PMID: 39064887 PMCID: PMC11279437 DOI: 10.3390/molecules29143308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2024] [Revised: 07/01/2024] [Accepted: 07/05/2024] [Indexed: 07/28/2024] Open
Abstract
Using a molecular modeling approach for Tau-binding sites, we modified our previously reported imaging agent, [125I]INFT, for the potential improvement of binding properties to Tau in an Alzheimer's disease (AD) brain. Two new derivatives, namely [125I]ISAS and [125I]NIPZ, were designed, where binding energies at site 1 of Tau were -7.4 and -6.0 kcal/mole, respectively, compared to [125I]INFT (-7.6 kcal/mole). The radiosynthesis of [125I]ISAS and [125I]NIPZ was carried out by using iodine-125 and purified chromatographically to achieve >90% purity. In vitro binding affinities (IC50) for Tau were as follows: INFT = 7.3 × 10-8 M; ISAS = 4.7 × 10-8 M; NIPZ > 10-6 M. The binding of [125I]ISAS to gray matter (GM) correlated with the presence of Tau in the AD brain, confirmed by anti-Tau immunohistochemistry. [125I]NIPZ did not bind to Tau, with similar levels of binding observed in GM and white matter (WM). Four radiotracers were compared and the rank order of binding to Tau was found to be [125I]IPPI > [125I]INFT > [125I]ISAS >>> [125I]NIPZ with GM/WM ratios of [125I]IPPI = 7.74 > [125I]INFT = 4.86 > [125I]ISAS = 3.62 >> [125I]NIPZ = 1.24. The predictive value of Chimera-AutoDock for structurally related compounds binding to the Tau binding sites (measured as binding energy) was good. A binding energy of less than -7 kcal/mole is necessary and less than -8 kcal/mole will be more suitable for developing imaging agents.
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Affiliation(s)
| | | | | | - Jogeshwar Mukherjee
- Preclinical Imaging, Department of Radiological Sciences, University of California-Irvine, Irvine, CA 92697, USA; (S.A.S.); (C.G.P.); (C.L.)
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Lindberg A, Murrell E, Tong J, Mason NS, Sohn D, Sandell J, Ström P, Stehouwer JS, Lopresti BJ, Viklund J, Svensson S, Mathis CA, Vasdev N. Ligand-based design of [ 18F]OXD-2314 for PET imaging in non-Alzheimer's disease tauopathies. Nat Commun 2024; 15:5109. [PMID: 38877019 PMCID: PMC11178805 DOI: 10.1038/s41467-024-49258-1] [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: 07/18/2023] [Accepted: 05/30/2024] [Indexed: 06/16/2024] Open
Abstract
Positron emission tomography (PET) imaging of tau aggregation in Alzheimer's disease (AD) is helping to map and quantify the in vivo progression of AD pathology. To date, no high-affinity tau-PET radiopharmaceutical has been optimized for imaging non-AD tauopathies. Here we show the properties of analogues of a first-in-class 4R-tau lead, [18F]OXD-2115, using ligand-based design. Over 150 analogues of OXD-2115 were synthesized and screened in post-mortem brain tissue for tau affinity against [3H]OXD-2115, and in silico models were used to predict brain uptake. [18F]OXD-2314 was identified as a selective, high-affinity non-AD tau PET radiotracer with favorable brain uptake, dosimetry, and radiometabolite profiles in rats and non-human primate and is being translated for first-in-human PET studies.
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Affiliation(s)
- Anton Lindberg
- Azrieli Centre for Neuro-Radiochemistry, Brain Health Imaging Centre, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Canada
| | - Emily Murrell
- Azrieli Centre for Neuro-Radiochemistry, Brain Health Imaging Centre, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Canada
- Department of Psychiatry, University of Toronto, Toronto, Canada
| | - Junchao Tong
- Azrieli Centre for Neuro-Radiochemistry, Brain Health Imaging Centre, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Canada
| | - N Scott Mason
- Department of Radiology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Daniel Sohn
- Oxiant Discovery, SE-15136, Södertälje, Sweden
| | | | - Peter Ström
- Novandi Chemistry AB, SE-15136, Södertälje, Sweden
| | | | - Brian J Lopresti
- Department of Radiology, University of Pittsburgh, Pittsburgh, PA, USA
| | | | | | - Chester A Mathis
- Department of Radiology, University of Pittsburgh, Pittsburgh, PA, USA.
| | - Neil Vasdev
- Azrieli Centre for Neuro-Radiochemistry, Brain Health Imaging Centre, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Canada.
- Department of Psychiatry, University of Toronto, Toronto, Canada.
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5
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Kong Y, Cao L, Xie F, Wang X, Zuo C, Shi K, Rominger A, Huang Q, Xiao J, Jiang D, Guan Y, Ni R. Reduced SV2A and GABA A receptor levels in the brains of type 2 diabetic rats revealed by [ 18F]SDM-8 and [ 18F]flumazenil PET. Biomed Pharmacother 2024; 172:116252. [PMID: 38325265 DOI: 10.1016/j.biopha.2024.116252] [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: 09/11/2023] [Revised: 12/19/2023] [Accepted: 02/02/2024] [Indexed: 02/09/2024] Open
Abstract
PURPOSE Type 2 diabetes mellitus (T2DM) is associated with a greater risk of Alzheimer's disease. Synaptic impairment and protein aggregates have been reported in the brains of T2DM models. Here, we assessed whether neurodegenerative changes in synaptic vesicle 2 A (SV2A), γ-aminobutyric acid type A (GABAA) receptor, amyloid-β, tau and receptor for advanced glycosylation end product (RAGE) can be detected in vivo in T2DM rats. METHODS Positron emission tomography (PET) using [18F]SDM-8 (SV2A), [18F]flumazenil (GABAA receptor), [18F]florbetapir (amyloid-β), [18F]PM-PBB3 (tau), and [18F]FPS-ZM1 (RAGE) was carried out in 12-month-old diabetic Zucker diabetic fatty (ZDF) and SpragueDawley (SD) rats. Immunofluorescence staining, Thioflavin S staining, proteomic profiling and pathway analysis were performed on the brain tissues of ZDF and SD rats. RESULTS Reduced cortical [18F]SDM-8 uptake and cortical and hippocampal [18F]flumazenil uptake were observed in 12-month-old ZDF rats compared to SD rats. The regional uptake of [18F]florbetapir and [18F]PM-PBB3 was comparable in the brains of 12-month-old ZDF and SD rats. Immunofluorescence staining revealed Thioflavin S-negative, phospho-tau-positive inclusions in the cortex and hypothalamus in the brains of ZDF rats and the absence of amyloid-beta deposits. The level of GABAA receptors was lower in the cortex of ZDF rats than SD rats. Proteomic analysis further demonstrated that, compared with SD rats, synaptic-related proteins and pathways were downregulated in the hippocampus of ZDF rats. CONCLUSION These findings provide in vivo evidence for regional reductions in SV2A and GABAA receptor levels in the brains of aged T2DM ZDF rats.
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Affiliation(s)
- Yanyan Kong
- PET Center, Huashan Hospital, Fudan University, Shanghai, China
| | - Lei Cao
- PET Center, Huashan Hospital, Fudan University, Shanghai, China; Inst. Regenerative Medicine, University of Zurich, Zurich, Switzerland
| | - Fang Xie
- PET Center, Huashan Hospital, Fudan University, Shanghai, China
| | - Xiuzhe Wang
- Dept. Neurology, Shanghai Sixth People's Hospital affiliated with Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Chuantao Zuo
- PET Center, Huashan Hospital, Fudan University, Shanghai, China
| | - Kuangyu Shi
- Dept. Nuclear Medicine, Inselspital, Bern University Hospital, Bern, Switzerland
| | - Axel Rominger
- Dept. Nuclear Medicine, Inselspital, Bern University Hospital, Bern, Switzerland
| | - Qi Huang
- PET Center, Huashan Hospital, Fudan University, Shanghai, China
| | - Jianfei Xiao
- PET Center, Huashan Hospital, Fudan University, Shanghai, China
| | - Donglang Jiang
- PET Center, Huashan Hospital, Fudan University, Shanghai, China
| | - Yihui Guan
- PET Center, Huashan Hospital, Fudan University, Shanghai, China.
| | - Ruiqing Ni
- Inst. Regenerative Medicine, University of Zurich, Zurich, Switzerland; Dept. Nuclear Medicine, Inselspital, Bern University Hospital, Bern, Switzerland; Inst. Biomedical Engineering, University of Zurich & ETH Zurich, Zurich, Switzerland.
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6
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De Leiris N, Perret P, Lombardi C, Gözel B, Chierici S, Millet P, Debiossat M, Bacot S, Tournier BB, Chames P, Lenormand JL, Ghezzi C, Fagret D, Moulin M. A single-domain antibody for the detection of pathological Tau protein in the early stages of oligomerization. J Transl Med 2024; 22:163. [PMID: 38365700 PMCID: PMC10870657 DOI: 10.1186/s12967-024-04987-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Accepted: 02/12/2024] [Indexed: 02/18/2024] Open
Abstract
BACKGROUND Soluble oligomeric forms of Tau protein have emerged as crucial players in the propagation of Tau pathology in Alzheimer's disease (AD). Our objective is to introduce a single-domain antibody (sdAb) named 2C5 as a novel radiotracer for the efficient detection and longitudinal monitoring of oligomeric Tau species in the human brain. METHODS The development and production of 2C5 involved llama immunization with the largest human Tau isoform oligomers of different maturation states. Subsequently, 2C5 underwent comprehensive in vitro characterization for affinity and specificity via Enzyme-Linked Immunosorbent Assay and immunohistochemistry on human brain slices. Technetium-99m was employed to radiolabel 2C5, followed by its administration to healthy mice for biodistribution analysis. RESULTS 2C5 exhibited robust binding affinity towards Tau oligomers (Kd = 6.280 nM ± 0.557) and to Tau fibers (Kd = 5.024 nM ± 0.453), with relatively weaker binding observed for native Tau protein (Kd = 1791 nM ± 8.714) and amyloid peptide (Kd > 10,000 nM). Remarkably, this SdAb facilitated immuno-histological labeling of pathological forms of Tau in neurons and neuritic plaques, yielding a high-contrast outcome in AD patients, closely mirroring the performance of reference antibodies AT8 and T22. Furthermore, 2C5 SdAb was successfully radiolabeled with 99mTc, preserving stability for up to 6 h post-radiolabeling (radiochemical purity > 93%). However, following intravenous injection into healthy mice, the predominant uptake occurred in kidneys, amounting to 115.32 ± 3.67, 97.70 ± 43.14 and 168.20 ± 34.52% of injected dose per gram (% ID/g) at 5, 10 and 45 min respectively. Conversely, brain uptake remained minimal at all measured time points, registering at 0.17 ± 0.03, 0.12 ± 0.07 and 0.02 ± 0.01% ID/g at 5, 10 and 45 min post-injection respectively. CONCLUSION 2C5 demonstrates excellent affinity and specificity for pathological Tau oligomers, particularly in their early stages of oligomerization. However, the current limitation of insufficient blood-brain barrier penetration necessitates further modifications before considering its application in nuclear medicine imaging for humans.
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Affiliation(s)
- Nicolas De Leiris
- University Grenoble Alpes, Clinique Universitaire de Médecine Nucléaire, INSERM, Centre Hospitalier Universitaire Grenoble Alpes, LRB, CS 10217, 38043, Grenoble CEDEX 9, France.
| | - Pascale Perret
- University Grenoble Alpes, INSERM, LRB, 38000, Grenoble, France
| | | | - Bülent Gözel
- University Grenoble Alpes, INSERM, LRB, 38000, Grenoble, France
| | - Sabine Chierici
- University Grenoble Alpes, CNRS, DCM, 38000, Grenoble, France
| | - Philippe Millet
- Division of Adult Psychiatry, Department of Psychiatry, Geneva University Hospitals, Geneva, Switzerland
| | | | - Sandrine Bacot
- University Grenoble Alpes, INSERM, LRB, 38000, Grenoble, France
| | - Benjamin B Tournier
- Division of Adult Psychiatry, Department of Psychiatry, Geneva University Hospitals, Geneva, Switzerland
| | - Patrick Chames
- Aix Marseille University, CNRS, INSERM, Institut Paoli-Calmettes, CRCM, Marseille, France
| | | | | | - Daniel Fagret
- University Grenoble Alpes, INSERM, LRB, 38000, Grenoble, France
| | - Marcelle Moulin
- University Grenoble Alpes, INSERM, LRB, 38000, Grenoble, France
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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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Sahara N, Higuchi M. Diagnostic and therapeutic targeting of pathological tau proteins in neurodegenerative disorders. FEBS Open Bio 2024; 14:165-180. [PMID: 37746832 PMCID: PMC10839408 DOI: 10.1002/2211-5463.13711] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Revised: 09/06/2023] [Accepted: 09/22/2023] [Indexed: 09/26/2023] Open
Abstract
Tauopathies, characterized by fibrillar tau accumulation in neurons and glial cells, constitute a major neuropathological category of neurodegenerative diseases. Neurofibrillary tau lesions are strongly associated with cognitive deficits in these diseases, but the causal mechanisms underlying tau-induced neuronal dysfunction remain unresolved. Recent advances in cryo-electron microscopy examination have revealed various core structures of tau filaments from different tauopathy patients, which can be used to classify tauopathies. In vivo visualization of tau pathology is now available using several tau positron emission tomography tracers. Among these radioprobes, PM-PBB3 allows high-contrast imaging of tau deposits in the brains of patients with diverse disorders and tauopathy mouse models. Selective degradation of pathological tau species by the ubiquitin-proteasome system or autophagy machinery is a potential therapeutic strategy. Alternatively, the non-cell-autonomous clearance of pathological tau species through neuron-glia networks could be reinforced as a disease-modifying treatment. In addition, the development of neuroinflammatory biomarkers is required for understanding the contribution of immunocompetent cells in the brain to preventing neurodegeneration. This review provides an overview of the current research and development of diagnostic and therapeutic agents targeting divergent tau pathologies.
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Affiliation(s)
- Naruhiko Sahara
- Department of Functional Brain Imaging, Institute for Quantum Medical SciencesNational Institutes for Quantum Science and TechnologyChibaJapan
| | - Makoto Higuchi
- Department of Functional Brain Imaging, Institute for Quantum Medical SciencesNational Institutes for Quantum Science and TechnologyChibaJapan
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9
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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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10
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Simon SS, Varangis E, Lee S, Gu Y, Gazes Y, Razlighi QR, Habeck C, Stern Y. In vivo tau is associated with change in memory and processing speed, but not reasoning, in cognitively unimpaired older adults. Neurobiol Aging 2024; 133:28-38. [PMID: 38376885 PMCID: PMC10879688 DOI: 10.1016/j.neurobiolaging.2023.10.001] [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: 03/07/2023] [Revised: 08/30/2023] [Accepted: 10/01/2023] [Indexed: 02/21/2024]
Abstract
The relationship between tau deposition and cognitive decline in cognitively healthy older adults is still unclear. The tau PET tracer 18F-MK-6240 has shown favorable imaging characteristics to identify early tau deposition in aging. We evaluated the relationship between in vivo tau levels (18F-MK-6240) and retrospective cognitive change over 5 years in episodic memory, processing speed, and reasoning. For tau quantification, a set of regions of interest (ROIs) was selected a priori based on previous literature: (1) total-ROI comprising selected areas, (2) medial temporal lobe-ROI, and (3) lateral temporal lobe-ROI and cingulate/parietal lobe-ROI. Higher tau burden in most ROIs was associated with a steeper decline in memory and speed. There were no associations between tau and reasoning change. The novelty of this finding is that tau burden may affect not only episodic memory, a well-established finding but also processing speed. Our finding reinforces the notion that early tau deposition in areas related to Alzheimer's disease is associated with cognitive decline in cognitively unimpaired individuals, even in a sample with low amyloid-β pathology.
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Affiliation(s)
- Sharon Sanz Simon
- Cognitive Neuroscience Division, Department of Neurology, Columbia University, Vagelos College of Physicians and Surgeons, New York, NY, USA
| | - Eleanna Varangis
- School of Kinesiology, University of Michigan, Ann Arbor, MI, USA; Concussion Center, University of Michigan, Ann Arbor, MI, USA
| | - Seonjoo Lee
- Department of Biostatistics, Mailman School of Public Health, Columbia University, New York, NY, USA
| | - Yian Gu
- Cognitive Neuroscience Division, Department of Neurology, Columbia University, Vagelos College of Physicians and Surgeons, New York, NY, USA; Department of Epidemiology, Joseph P. Mailman School of Public Health, Columbia University, New York, NY, USA
| | - Yunglin Gazes
- Cognitive Neuroscience Division, Department of Neurology, Columbia University, Vagelos College of Physicians and Surgeons, New York, NY, USA
| | | | - Christian Habeck
- Cognitive Neuroscience Division, Department of Neurology, Columbia University, Vagelos College of Physicians and Surgeons, New York, NY, USA
| | - Yaakov Stern
- Cognitive Neuroscience Division, Department of Neurology, Columbia University, Vagelos College of Physicians and Surgeons, New York, NY, USA.
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11
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Gogola A, Cohen AD, Snitz B, Minhas D, Tudorascu D, Ikonomovic MD, Shaaban CE, Doré V, Matan C, Bourgeat P, Mason NS, Leuzy A, Aizenstein H, Mathis CA, Lopez OL, Lopresti BJ, Villemagne VL. Implementation and Assessment of Tau Thresholds in Non-Demented Individuals as Predictors of Cognitive Decline in Tau Imaging Studies. J Alzheimers Dis 2024; 100:S75-S92. [PMID: 39121123 DOI: 10.3233/jad-240543] [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: 08/11/2024]
Abstract
Background Tau accumulation in Alzheimer's disease is associated with short term clinical progression and faster rates of cognitive decline in individuals with high amyloid-β deposition. Defining an optimal threshold of tau accumulation predictive of cognitive decline remains a challenge. Objective We tested the ability of regional tau PET sensitivity and specificity thresholds to predict longitudinal cognitive decline. We also tested the predictive performance of thresholds in the proposed new NIA-AA biological staging for Alzheimer's disease where multiple levels of tau positivity are used to stage participants. Methods 18F-flortaucipir scans from 301 non-demented participants were processed and sampled. Four cognitive measures were assessed longitudinally. Regional standardized uptake value ratios were split into infra- and suprathreshold groups at baseline using previously derived thresholds. Survival analysis, log rank testing, and Generalized Estimation Equations assessed the relationship between the application of regional sensitivity/specificity thresholds and change in cognitive measures as well as tau threshold performance in predicting cognitive decline within the new NIA-AA biological staging. Results The meta temporal region was best for predicting risk of short-term cognitive decline in suprathreshold, as compared to infrathreshold participants. When applying multiple levels of tau positivity, each subsequent level of tau identified cognitive decline at earlier timepoints. Conclusions When using 18F-flortaucipir, meta temporal suprathreshold classification was associated with increased risk of cognitive decline, suggesting that abnormal tau deposition in the cortex predicts decline. Likewise, the application of multiple levels of tau clearly predicts the distinctive cognitive trajectories in the new NIA-AA biological staging framework.
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Affiliation(s)
- Alexandra Gogola
- Department of Radiology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Ann D Cohen
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, USA
- Alzheimer's Disease Research Center, University of Pittsburgh, Pittsburgh, PA, USA
| | - Beth Snitz
- Alzheimer's Disease Research Center, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Neurology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Davneet Minhas
- Department of Radiology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Dana Tudorascu
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, USA
- Alzheimer's Disease Research Center, University of Pittsburgh, Pittsburgh, PA, USA
| | - Milos D Ikonomovic
- Alzheimer's Disease Research Center, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Neurology, University of Pittsburgh, Pittsburgh, PA, USA
- Geriatric Research Education and Clinical Center, Veterans Affairs Pittsburgh Healthcare System, Pittsburgh, PA, USA
| | - C Elizabeth Shaaban
- Alzheimer's Disease Research Center, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Epidemiology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Vincent Doré
- Department of Molecular Imaging & Therapy, Austin Health, Melbourne, VIC, Australia
- Commonwealth Scientific and Industrial Research Organisation Health & Biosecurity, Melbourne, VIC, Australia
| | - Cristy Matan
- Department of Radiology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Pierrick Bourgeat
- Commonwealth Scientific and Industrial Research Organisation Health & Biosecurity, Melbourne, VIC, Australia
| | - N Scott Mason
- Department of Radiology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Antoine Leuzy
- Critical Path for Alzheimer's Disease (CPAD) Consortium, Critical Path Institute, Tucson, AZ, USA
| | - Howard Aizenstein
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, USA
- Alzheimer's Disease Research Center, University of Pittsburgh, Pittsburgh, PA, USA
| | - Chester A Mathis
- Department of Radiology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Oscar L Lopez
- Alzheimer's Disease Research Center, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Neurology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Brian J Lopresti
- Department of Radiology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Victor L Villemagne
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, USA
- Alzheimer's Disease Research Center, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Molecular Imaging & Therapy, Austin Health, Melbourne, VIC, Australia
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12
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Taha A, Alassi A, Gjedde A, Wong DF. Transforming Neurology and Psychiatry: Organ-specific PET Instrumentation and Clinical Applications. PET Clin 2024; 19:95-103. [PMID: 37813719 DOI: 10.1016/j.cpet.2023.06.002] [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: 10/11/2023]
Abstract
PET technology has immense potential for furthering understanding of the brain and associated disorders, including advancements in high-resolution tomographs and hybrid imaging modalities. Novel radiotracers targeting specific neurotransmitter systems and molecular markers provide opportunities to unveil intricate mechanisms underlying neurologic and psychiatric conditions. As PET imaging techniques and analysis methods continue to be refined, the field is poised to make significant contributions to personalized medicine for more targeted and effective interventions. PET instrumentation has advanced the fields of neurology and psychiatry, providing insights into pathophysiology and development of effective treatments.
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Affiliation(s)
- Ahmed Taha
- Mallinckrodt Institute of Radiology, Washington University in St Louis, Saint Louis, MO, USA
| | - Amer Alassi
- Mallinckrodt Institute of Radiology, Washington University in St Louis, Saint Louis, MO, USA
| | - Albert Gjedde
- Department of Clinical Medicine, Translational Neuropsychiatry Unit, Aarhus University, Denmark; Department of Neuroscience, University of Copenhagen, Denmark
| | - Dean F Wong
- Mallinckrodt Institute of Radiology, Departments of Radiology, Psychiatry, Neurology, Neuroscience, Washington University in St Louis, Saint Louis, MO, USA.
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13
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Rani N, Alm KH, Corona-Long CA, Speck CL, Soldan A, Pettigrew C, Zhu Y, Albert M, Bakker A. Tau PET burden in Brodmann areas 35 and 36 is associated with individual differences in cognition in non-demented older adults. Front Aging Neurosci 2023; 15:1272946. [PMID: 38161595 PMCID: PMC10757623 DOI: 10.3389/fnagi.2023.1272946] [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: 08/04/2023] [Accepted: 10/23/2023] [Indexed: 01/03/2024] Open
Abstract
Introduction The accumulation of neurofibrillary tau tangles, a neuropathological hallmark of Alzheimer's disease (AD), occurs in medial temporal lobe (MTL) regions early in the disease process, with some of the earliest deposits localized to subregions of the entorhinal cortex. Although functional specialization of entorhinal cortex subregions has been reported, few studies have considered functional associations with localized tau accumulation. Methods In this study, stepwise linear regressions were used to examine the contributions of regional tau burden in specific MTL subregions, as measured by 18F-MK6240 PET, to individual variability in cognition. Dependent measures of interest included the Clinical Dementia Rating Sum of Boxes (CDR-SB), Mini Mental State Examination (MMSE), and composite scores of delayed episodic memory and language. Other model variables included age, sex, education, APOE4 status, and global amyloid burden, indexed by 11C-PiB. Results Tau burden in right Brodmann area 35 (BA35), left and right Brodmann area 36 (BA36), and age each uniquely contributed to the proportion of explained variance in CDR-SB scores, while right BA36 and age were also significant predictors of MMSE scores, and right BA36 was significantly associated with delayed episodic memory performance. Tau burden in both left and right BA36, along with education, uniquely contributed to the proportion of explained variance in language composite scores. Importantly, the addition of more inclusive ROIs, encompassing less granular segmentation of the entorhinal cortex, did not significantly contribute to explained variance in cognition across any of the models. Discussion These findings suggest that the ability to quantify tau burden in more refined MTL subregions may better account for individual differences in cognition, which may improve the identification of non-demented older adults who are on a trajectory of decline due to AD.
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Affiliation(s)
- Nisha Rani
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Kylie H. Alm
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Caitlin A. Corona-Long
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Caroline L. Speck
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Anja Soldan
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Corinne Pettigrew
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Yuxin Zhu
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Marilyn Albert
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Arnold Bakker
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, United States
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, United States
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14
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Gogola A, Lopresti BJ, Tudorascu D, Snitz B, Minhas D, Doré V, Ikonomovic MD, Shaaban CE, Matan C, Bourgeat P, Mason NS, Aizenstein H, Mathis CA, Klunk WE, Rowe CC, Lopez OL, Cohen AD, Villemagne VL. Biostatistical Estimation of Tau Threshold Hallmarks (BETTH) Algorithm for Human Tau PET Imaging Studies. J Nucl Med 2023; 64:1798-1805. [PMID: 37709531 PMCID: PMC10626371 DOI: 10.2967/jnumed.123.265941] [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: 04/26/2023] [Revised: 08/03/2023] [Indexed: 09/16/2023] Open
Abstract
A methodology for determining tau PET thresholds is needed to confidently detect early tau deposition. We compared multiple threshold-determining methods in participants who underwent either 18F-flortaucipir or 18F-MK-6240 PET scans. Methods: 18F-flortaucipir (n = 798) and 18F-MK-6240 (n = 216) scans were processed and sampled to obtain regional SUV ratios. Subsamples of the cohorts were based on participant diagnosis, age, amyloid-β status (positive or negative), and neurodegeneration status (positive or negative), creating older-adult (age ≥ 55 y) cognitively unimpaired (amyloid-β-negative, neurodegeneration-negative) and cognitively impaired (mild cognitive impairment/Alzheimer disease, amyloid-β-positive, neurodegeneration-positive) groups, and then were further subsampled via matching to reduce significant differences in diagnostic prevalence, age, and Mini-Mental State Examination score. We used the biostatistical estimation of tau threshold hallmarks (BETTH) algorithm to determine sensitivity and specificity in 6 composite regions. Results: Parametric double receiver operating characteristic analysis yielded the greatest joint sensitivity in 5 of the 6 regions, whereas hierarchic clustering, gaussian mixture modeling, and k-means clustering all yielded perfect joint specificity (2.00) in all regions. Conclusion: When 18F-flortaucipir and 18F-MK-6240 are used, Alzheimer disease-related tau status is best assessed using 2 thresholds, a sensitivity one based on parametric double receiver operating characteristic analysis and a specificity one based on gaussian mixture modeling, delimiting an uncertainty zone indicating participants who may require further evaluation.
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Affiliation(s)
- Alexandra Gogola
- Department of Radiology, University of Pittsburgh, Pittsburgh, Pennsylvania;
| | - Brian J Lopresti
- Department of Radiology, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Dana Tudorascu
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Beth Snitz
- Department of Neurology, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Davneet Minhas
- Department of Radiology, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Vincent Doré
- Department of Molecular Imaging and Therapy, Austin Health, Melbourne, Victoria, Australia
- Health and Biosecurity, Commonwealth Scientific and Industrial Research Organisation, Melbourne, Victoria, Australia
| | - Milos D Ikonomovic
- Department of Neurology, University of Pittsburgh, Pittsburgh, Pennsylvania
- Geriatric Research Education and Clinical Center, Veterans Affairs Pittsburgh Healthcare System, Pittsburgh, Pennsylvania; and
| | - C Elizabeth Shaaban
- Department of Epidemiology, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Cristy Matan
- Department of Radiology, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Pierrick Bourgeat
- Health and Biosecurity, Commonwealth Scientific and Industrial Research Organisation, Melbourne, Victoria, Australia
| | - N Scott Mason
- Department of Radiology, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Howard Aizenstein
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Chester A Mathis
- Department of Radiology, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - William E Klunk
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Christopher C Rowe
- Department of Molecular Imaging and Therapy, Austin Health, Melbourne, Victoria, Australia
| | - Oscar L Lopez
- Department of Neurology, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Ann D Cohen
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Victor L Villemagne
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, Pennsylvania
- Department of Molecular Imaging and Therapy, Austin Health, Melbourne, Victoria, Australia
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15
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Kunach P, Vaquer-Alicea J, Smith MS, Hopewell R, Monistrol J, Moquin L, Therriault J, Tissot C, Rahmouni N, Massarweh G, Soucy JP, Guiot MC, Shoichet BK, Rosa-Neto P, Diamond MI, Shahmoradian SH. Cryo-EM structure of Alzheimer's disease tau filaments with PET ligand MK-6240. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.22.558671. [PMID: 37790438 PMCID: PMC10542181 DOI: 10.1101/2023.09.22.558671] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 10/05/2023]
Abstract
Positron Emission Tomography (PET) ligands have advanced Alzheimer's disease (AD) diagnosis and treatment. Using autoradiography and cryo-EM, we identified AD brain tissue with elevated tau burden, purified filaments, and determined the structure of second-generation high avidity PET ligand MK-6240 at 2.31 Å resolution, which bound at a 1:1 ratio within the cleft of tau paired-helical filament (PHF), engaging with glutamine 351, lysine K353, and isoleucine 360. This information elucidates the basis of MK-6240 PET in quantifying PHF deposits in AD and may facilitate the structure-based design of superior ligands against tau amyloids.
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Affiliation(s)
- Peter Kunach
- Department of Neurology, McGill University, Montreal, Quebec, Canada
- Center for Alzheimer’s and Neurodegenerative Diseases, Peter O’Donnell Jr. Brain Institute, Dallas, TX, United States
| | - Jaime Vaquer-Alicea
- Center for Alzheimer’s and Neurodegenerative Diseases, Peter O’Donnell Jr. Brain Institute, Dallas, TX, United States
| | - Matthew S. Smith
- Department of Pharmaceutical Chemistry, UCSF, San Francisco, CA, United States
- Program of Biophysics, UCSF, San Francisco, CA, United States
| | | | - Jim Monistrol
- Center for Alzheimer’s and Neurodegenerative Diseases, Peter O’Donnell Jr. Brain Institute, Dallas, TX, United States
| | - Luc Moquin
- Montreal Neurological Institute, Montreal, Quebec, Canada
| | - Joseph Therriault
- Department of Neurology, McGill University, Montreal, Quebec, Canada
| | - Cecile Tissot
- Department of Neurology, McGill University, Montreal, Quebec, Canada
| | - Nesrine Rahmouni
- Department of Neurology, McGill University, Montreal, Quebec, Canada
| | | | | | - Marie-Christine Guiot
- Department of Neurology, McGill University, Montreal, Quebec, Canada
- Montreal Neurological Institute, Montreal, Quebec, Canada
| | - Brian K. Shoichet
- Department of Pharmaceutical Chemistry, UCSF, San Francisco, CA, United States
| | - Pedro Rosa-Neto
- Department of Neurology, McGill University, Montreal, Quebec, Canada
| | - Marc I. Diamond
- Center for Alzheimer’s and Neurodegenerative Diseases, Peter O’Donnell Jr. Brain Institute, Dallas, TX, United States
| | - Sarah H. Shahmoradian
- Center for Alzheimer’s and Neurodegenerative Diseases, Peter O’Donnell Jr. Brain Institute, Dallas, TX, United States
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16
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Cools R, Kerkhofs K, Leitao RCF, Bormans G. Preclinical Evaluation of Novel PET Probes for Dementia. Semin Nucl Med 2023; 53:599-629. [PMID: 37149435 DOI: 10.1053/j.semnuclmed.2023.03.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Accepted: 03/24/2023] [Indexed: 05/08/2023]
Abstract
The development of novel PET imaging agents that selectively bind specific dementia-related targets can contribute significantly to accurate, differential and early diagnosis of dementia causing diseases and support the development of therapeutic agents. Consequently, in recent years there has been a growing body of literature describing the development and evaluation of potential new promising PET tracers for dementia. This review article provides a comprehensive overview of novel dementia PET probes under development, classified by their target, and pinpoints their preclinical evaluation pathway, typically involving in silico, in vitro and ex/in vivo evaluation. Specific target-associated challenges and pitfalls, requiring extensive and well-designed preclinical experimental evaluation assays to enable successful clinical translation and avoid shortcomings observed for previously developed 'well-established' dementia PET tracers are highlighted in this review.
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Affiliation(s)
- Romy Cools
- Laboratory for Radiopharmaceutical Research, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium
| | - Kobe Kerkhofs
- Laboratory for Radiopharmaceutical Research, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium; NURA, Belgian Nuclear Research Centre (SCK CEN), Mol, Belgium
| | - Renan C F Leitao
- Laboratory for Radiopharmaceutical Research, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium
| | - Guy Bormans
- Laboratory for Radiopharmaceutical Research, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium.
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17
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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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18
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Graham TJA, Lindberg A, Tong J, Stehouwer JS, Vasdev N, Mach RH, Mathis CA. In Silico Discovery and Subsequent Characterization of Potent 4R-Tauopathy Positron Emission Tomography Radiotracers. J Med Chem 2023; 66:10628-10638. [PMID: 37487189 PMCID: PMC10424182 DOI: 10.1021/acs.jmedchem.3c00775] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Indexed: 07/26/2023]
Abstract
A chemical fingerprint search identified Z3777013540 (1-(5-(6-fluoro-1H-indol-2-yl)pyrimidin-2-yl)piperidin-4-ol; 1) as a potential 4R-tau binding ligand. Binding assays in post-mortem Alzheimer's disease (AD), progressive supranuclear palsy (PSP), and corticobasal degeneration (CBD) brain with [3H]1 provided KD (nM) values in AD = 4.0, PSP = 5.1, and CBD = 4.5. In vivo positron emission tomography (PET) imaging in rats with [18F]1 demonstrated good brain penetration and rapid clearance from normal brain tissues. A subsequent molecular similarity search using 1 as the query revealed an additional promising compound, Z4169252340 (4-(5-(6-fluoro-1H-indol-2-yl)pyrimidin-2-yl)morpholine; 21). Binding assays with [3H]21 provided KD (nM) values in AD = 1.2, PSP = 1.6, and CBD = 1.7 and lower affinities for binding aggregated α-synuclein and amyloid-beta. PET imaging in rats with [18F]21 demonstrated a higher brain penetration than [18F]1 and rapid clearance from normal brain tissues. We anticipate that 1 and 21 will be useful for the identification of other potent novel 4R-tau radiotracers.
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Affiliation(s)
- Thomas J. A. Graham
- Department
of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, United
States
| | - Anton Lindberg
- Azrieli
Centre for Neuro-Radiochemistry, Brain Health Imaging Centre, Centre for Addiction and Mental Health, Toronto, Ontario M5T 1R8, Canada
| | - Junchao Tong
- Azrieli
Centre for Neuro-Radiochemistry, Brain Health Imaging Centre, Centre for Addiction and Mental Health, Toronto, Ontario M5T 1R8, Canada
| | - Jeffrey S. Stehouwer
- Department
of Radiology, University of Pittsburgh, Pittsburgh, Pennsylvania 15213, United States
| | - Neil Vasdev
- Azrieli
Centre for Neuro-Radiochemistry, Brain Health Imaging Centre, Centre for Addiction and Mental Health, Toronto, Ontario M5T 1R8, Canada
- Department
of Psychiatry, University of Toronto, Toronto, Ontario M5T 1R8, Canada
| | - Robert H. Mach
- Department
of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, United
States
| | - Chester A. Mathis
- Department
of Radiology, University of Pittsburgh, Pittsburgh, Pennsylvania 15213, United States
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19
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Xiang J, Tao Y, Xia Y, Luo S, Zhao Q, Li B, Zhang X, Sun Y, Xia W, Zhang M, Kang SS, Ahn EH, Liu X, Xie F, Guan Y, Yang JJ, Bu L, Wu S, Wang X, Cao X, Liu C, Zhang Z, Li D, Ye K. Development of an α-synuclein positron emission tomography tracer for imaging synucleinopathies. Cell 2023; 186:3350-3367.e19. [PMID: 37421950 PMCID: PMC10527432 DOI: 10.1016/j.cell.2023.06.004] [Citation(s) in RCA: 32] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Revised: 05/16/2023] [Accepted: 06/07/2023] [Indexed: 07/10/2023]
Abstract
Synucleinopathies are characterized by the accumulation of α-synuclein (α-Syn) aggregates in the brain. Positron emission tomography (PET) imaging of synucleinopathies requires radiopharmaceuticals that selectively bind α-Syn deposits. We report the identification of a brain permeable and rapid washout PET tracer [18F]-F0502B, which shows high binding affinity for α-Syn, but not for Aβ or Tau fibrils, and preferential binding to α-Syn aggregates in the brain sections. Employing several cycles of counter screenings with in vitro fibrils, intraneuronal aggregates, and neurodegenerative disease brain sections from several mice models and human subjects, [18F]-F0502B images α-Syn deposits in the brains of mouse and non-human primate PD models. We further determined the atomic structure of the α-Syn fibril-F0502B complex by cryo-EM and revealed parallel diagonal stacking of F0502B on the fibril surface through an intense noncovalent bonding network via inter-ligand interactions. Therefore, [18F]-F0502B is a promising lead compound for imaging aggregated α-Syn in synucleinopathies.
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Affiliation(s)
- Jie Xiang
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA; Department of Neurobiology, Fourth Military Medical University, Xi'an, China
| | - Youqi Tao
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders, Ministry of Education, Shanghai Jiao Tong University, Shanghai, China; Zhangjiang Institute for Advanced Study, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Yiyuan Xia
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA; Department of Pathophysiology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China; Institute of Biomedical Sciences, School of Medicine, JiangHan University, #8, Sanjiaohu Rd., Wuhan 430056, China
| | - Shilin Luo
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA; Department of Pharmacy, the Second Xiangya Hospital, Central South University, Changsha, China
| | - Qinyue Zhao
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders, Ministry of Education, Shanghai Jiao Tong University, Shanghai, China; Zhangjiang Institute for Advanced Study, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Bowei Li
- Shenzhen Institute of Advanced Technology, University of Chinese Academy of Science, Shenzhen, Guangdong 518055, China
| | - Xiaoqian Zhang
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science & Technology, Wuhan 430022, China
| | - Yunpeng Sun
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 201210, China
| | - Wencheng Xia
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 201210, China
| | - Mingming Zhang
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 201210, China
| | - Seong Su Kang
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Eun-Hee Ahn
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Xia Liu
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Fang Xie
- Department of Nuclear Medicine & PET Center, Huashan Hospital, Fudan University, Shanghai, China
| | - Yihui Guan
- Department of Nuclear Medicine & PET Center, Huashan Hospital, Fudan University, Shanghai, China
| | - Jenny J Yang
- Department of Chemistry, Georgia State University, Atlanta, GA 30303, USA
| | - Lihong Bu
- PET-CT/MRI Center, Renmin Hospital of Wuhan University, Wuhan 430060, China
| | - Shengxi Wu
- Department of Neurobiology, Fourth Military Medical University, Xi'an, China
| | - Xiaochuan Wang
- Department of Pathophysiology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xuebing Cao
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science & Technology, Wuhan 430022, China
| | - Cong Liu
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 201210, China; State Key Laboratory of Chemical Biology, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032, China
| | - Zhentao Zhang
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan 430060, China.
| | - Dan Li
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders, Ministry of Education, Shanghai Jiao Tong University, Shanghai, China; Zhangjiang Institute for Advanced Study, Shanghai Jiao Tong University, Shanghai 200240, China.
| | - Keqiang Ye
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA; Faculty of Life and Health Sciences, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, Guangdong 518055, China.
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20
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Limpengco RR, Liang C, Sandhu YK, Mukherjee J. [ 125I]INFT: Synthesis and Evaluation of a New Imaging Agent for Tau Protein in Post-Mortem Human Alzheimer's Disease Brain. Molecules 2023; 28:5769. [PMID: 37570739 PMCID: PMC10421386 DOI: 10.3390/molecules28155769] [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: 06/03/2023] [Revised: 07/24/2023] [Accepted: 07/29/2023] [Indexed: 08/13/2023] Open
Abstract
Aggregation of Tau protein into paired helical filaments causing neurofibrillary tangles (NFT) is a neuropathological feature in Alzheimer's disease (AD). This study aimed to develop and evaluate the effectiveness of a novel radioiodinated tracer, 4-[125I]iodo-3-(1H-pyrrolo[2,3-c]pyridine-1-yl)pyridine ([125I]INFT), for binding to Tau protein in postmortem human AD brain. Radiosynthesis of [125I]INFT was carried out using electrophilic destannylation by iodine-125 and purified chromatographically. Computational modeling of INFT binding on Tau fibril was compared with IPPI. In vitro, autoradiography studies were conducted with [125I]INFT for Tau in AD and cognitively normal (CN) brains. [125I]INFT was produced in >95% purity. Molecular modeling of INFT revealed comparable binding energies to IPPI at site-1 of the Tau fibril with an affinity of IC50 = 7.3 × 10-8 M. Binding of [125I]INFT correlated with the presence of Tau in the AD brain, confirmed by anti-Tau immunohistochemistry. The ratio of average grey matter (GM) [125I]INFT in AD versus CN was found to be 5.9, and AD GM/white matter (WM) = 2.5. Specifically bound [125I]INFT to Tau in AD brains was displaced by IPPI (>90%). Monoamine oxidase inhibitor deprenyl had no effect and clorgyline had little effect on [125I]INFT binding. [125I]INFT is a less lipophilic imaging agent for Tau in AD.
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Affiliation(s)
- Roz R Limpengco
- Preclinical Imaging, Department of Radiological Sciences, University of California-Irvine, Irvine, CA 92697, USA
| | - Christopher Liang
- Preclinical Imaging, Department of Radiological Sciences, University of California-Irvine, Irvine, CA 92697, USA
| | - Yasmin K Sandhu
- Preclinical Imaging, Department of Radiological Sciences, University of California-Irvine, Irvine, CA 92697, USA
| | - Jogeshwar Mukherjee
- Preclinical Imaging, Department of Radiological Sciences, University of California-Irvine, Irvine, CA 92697, USA
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21
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Nikiforova A, Sedov I. Molecular Design of Magnetic Resonance Imaging Agents Binding to Amyloid Deposits. Int J Mol Sci 2023; 24:11152. [PMID: 37446329 DOI: 10.3390/ijms241311152] [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: 06/12/2023] [Revised: 06/27/2023] [Accepted: 06/29/2023] [Indexed: 07/15/2023] Open
Abstract
The ability to detect and monitor amyloid deposition in the brain using non-invasive imaging techniques provides valuable insights into the early diagnosis and progression of Alzheimer's disease and helps to evaluate the efficacy of potential treatments. Magnetic resonance imaging (MRI) is a widely available technique offering high-spatial-resolution imaging. It can be used to visualize amyloid deposits with the help of amyloid-binding diagnostic agents injected into the body. In recent years, a number of amyloid-targeted MRI probes have been developed, but none of them has entered clinical practice. We review the advances in the field and deduce the requirements for the molecular structure and properties of a diagnostic probe candidate. These requirements make up the base for the rational design of MRI-active small molecules targeting amyloid deposits. Particular attention is paid to the novel cryo-EM structures of the fibril aggregates and their complexes, with known binders offering the possibility to use computational structure-based design methods. With continued research and development, MRI probes may revolutionize the diagnosis and treatment of neurodegenerative diseases, ultimately improving the lives of millions of people worldwide.
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Affiliation(s)
- Alena Nikiforova
- Chemical Institute, Kazan Federal University, Kremlevskaya 18, 420008 Kazan, Russia
| | - Igor Sedov
- Chemical Institute, Kazan Federal University, Kremlevskaya 18, 420008 Kazan, Russia
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22
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Zhang S, Dong H, Bian J, Li D, Liu C. Targeting amyloid proteins for clinical diagnosis of neurodegenerative diseases. FUNDAMENTAL RESEARCH 2023; 3:505-519. [PMID: 38933553 PMCID: PMC11197785 DOI: 10.1016/j.fmre.2022.10.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Revised: 10/16/2022] [Accepted: 10/19/2022] [Indexed: 11/05/2022] Open
Abstract
Abnormal aggregation and accumulation of pathological amyloid proteins such as amyloid-β, Tau, and α-synuclein play key pathological roles and serve as histological hallmarks in different neurodegenerative diseases (NDs) such as Alzheimer's disease (AD) and Parkinson's disease (PD). In addition, various post-translational modifications (PTMs) have been identified on pathological amyloid proteins and are subjected to change during disease progression. Given the central role of amyloid proteins in NDs, tremendous efforts have been made to develop amyloid-targeting strategies for clinical diagnosis and molecular classification of NDs. In this review, we summarize two major strategies for targeting amyloid aggregates, with a focus on the trials in AD diagnosis. The first strategy is a positron emission tomography (PET) scan of protein aggregation in the brain. We mainly focus on introducing the development of small-molecule PET tracers for specifically recognizing pathological amyloid fibrils. The second strategy is the detection of PTM biomarkers on amyloid proteins in cerebrospinal fluid and plasma. We discuss the pathological roles of different PTMs in diseases and how we can use the PTM profile of amyloid proteins for clinical diagnosis. Finally, we point out the potential technical challenges of these two strategies, and outline other potential strategies, as well as a combination of multiple strategies, for molecular diagnosis of NDs.
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Affiliation(s)
- Shenqing Zhang
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Shanghai Jiao Tong University, Shanghai 200030, China
- School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200030, China
| | - Hui Dong
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 201210, China
- University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Jiang Bian
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Shanghai Jiao Tong University, Shanghai 200030, China
- School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200030, China
| | - Dan Li
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Shanghai Jiao Tong University, Shanghai 200030, China
- Bio-X-Renji Hospital Research Center, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200240, China
- Zhangjiang Institute for Advanced Study, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Cong Liu
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 201210, China
- State Key Laboratory of Bio-Organic and Natural Products Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032, China
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23
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Macedo AC, Tissot C, Therriault J, Servaes S, Wang YT, Fernandez-Arias J, Rahmouni N, Lussier FZ, Vermeiren M, Bezgin G, Vitali P, Ng KP, Zimmer ER, Guiot MC, Pascoal TA, Gauthier S, Rosa-Neto P. The Use of Tau PET to Stage Alzheimer Disease According to the Braak Staging Framework. J Nucl Med 2023:jnumed.122.265200. [PMID: 37321820 PMCID: PMC10394315 DOI: 10.2967/jnumed.122.265200] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Revised: 04/25/2023] [Indexed: 06/17/2023] Open
Abstract
Amyloid-β plaques and neurofibrillary tangles (NFTs) are the 2 histopathologic hallmarks of Alzheimer disease (AD). On the basis of the pattern of NFT distribution in the brain, Braak and Braak proposed a histopathologic staging system for AD. Braak staging provides a compelling framework for staging and monitoring of NFT progression in vivo using PET imaging. Because AD staging remains based on clinical features, there is an unmet need to translate neuropathologic staging to a biologic clinical staging system. Such a biomarker staging system might play a role in staging preclinical AD or in improving recruitment strategies for clinical trials. Here, we review the literature regarding AD staging with the Braak framework using tau PET imaging, here called PET-based Braak staging. Our aim is to summarize the efforts of implementing Braak staging using PET and assess correspondence with the Braak histopathologic descriptions and with AD biomarkers. Methods: We conducted a systematic literature search in May 2022 on PubMed and Scopus combining the terms "Alzheimer" AND "Braak" AND ("positron emission tomography" OR "PET"). Results: The database search returned 262 results, and after assessment for eligibility, 21 studies were selected. Overall, most studies indicate that PET-based Braak staging may be an efficient method to stage AD since it presents an adequate ability to discriminate between phases of the AD continuum and correlates with clinical, fluid, and imaging biomarkers of AD. However, the translation of the original Braak descriptions to tau PET was done taking into account the limitations of this imaging technique. This led to important interstudy variability in the anatomic definitions of Braak stage regions of interest. Conclusion: Refinements in this staging system are necessary to incorporate atypical variants and Braak-nonconformant cases. Further studies are needed to understand the possible applications of PET-based Braak staging to clinical practice and research. Furthermore, there is a need for standardization in the topographic definitions of Braak stage regions of interest to guarantee reproducibility and methodologic homogeneity across studies.
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Affiliation(s)
- Arthur C Macedo
- Department of Neurology and Neurosurgery, McGill University, Montréal, Québec, Canada
| | - Cécile Tissot
- Department of Neurology and Neurosurgery, McGill University, Montréal, Québec, Canada
| | - Joseph Therriault
- Department of Neurology and Neurosurgery, McGill University, Montréal, Québec, Canada
| | - Stijn Servaes
- Department of Neurology and Neurosurgery, McGill University, Montréal, Québec, Canada
| | - Yi-Ting Wang
- Department of Neurology and Neurosurgery, McGill University, Montréal, Québec, Canada
| | - Jaime Fernandez-Arias
- Department of Neurology and Neurosurgery, McGill University, Montréal, Québec, Canada
| | - Nesrine Rahmouni
- Department of Neurology and Neurosurgery, McGill University, Montréal, Québec, Canada
| | - Firoza Z Lussier
- Department of Psychiatry and Neurology, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Marie Vermeiren
- Department of Neurology and Neurosurgery, McGill University, Montréal, Québec, Canada
| | - Gleb Bezgin
- Department of Neurology and Neurosurgery, McGill University, Montréal, Québec, Canada
| | - Paolo Vitali
- Department of Neurology and Neurosurgery, McGill University, Montréal, Québec, Canada
| | - Kok Pin Ng
- Department of Neurology, National Neuroscience Institute, Singapore, Singapore
| | - Eduardo R Zimmer
- Department of Pharmacology, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil; and
| | | | - Tharick A Pascoal
- Department of Psychiatry and Neurology, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Serge Gauthier
- Department of Neurology and Neurosurgery, McGill University, Montréal, Québec, Canada
| | - Pedro Rosa-Neto
- Department of Neurology and Neurosurgery, McGill University, Montréal, Québec, Canada;
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24
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Guehl NJ, Dhaynaut M, Hanseeuw BJ, Moon SH, Lois C, Thibault E, Fu JF, Price JC, Johnson KA, El Fakhri G, Normandin MD. Measurement of Cerebral Perfusion Indices from the Early Phase of [ 18F]MK6240 Dynamic Tau PET Imaging. J Nucl Med 2023; 64:968-975. [PMID: 36997330 PMCID: PMC10241011 DOI: 10.2967/jnumed.122.265072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Revised: 01/26/2023] [Accepted: 01/26/2023] [Indexed: 04/01/2023] Open
Abstract
6-(fluoro-18F)-3-(1H-pyrrolo[2,3-c]pyridin-1-yl)isoquinolin-5-amine ([18F]MK6240) has high affinity and selectivity for hyperphosphorylated tau and readily crosses the blood-brain barrier. This study investigated whether the early phase of [18F]MK6240 can be used to provide a surrogate index of cerebral perfusion. Methods: Forty-nine subjects who were cognitively normal (CN), had mild cognitive impairment (MCI), or had Alzheimer's disease (AD) underwent paired dynamic [18F]MK6240 and [11C]Pittsburgh compound B (PiB) PET, as well as structural MRI to obtain anatomic information. Arterial blood samples were collected in a subset of 24 subjects for [18F]MK6240 scans to derive metabolite-corrected arterial input functions. Regional time-activity curves were extracted using atlases available in the Montreal Neurologic Institute template space and using FreeSurfer. The early phase of brain time-activity curves was analyzed using a 1-tissue-compartment model to obtain a robust estimate of the rate of transfer from plasma to brain tissue, K 1 (mL⋅cm-3⋅min-1), and the simplified reference tissue model 2 was investigated for noninvasive estimation of the relative delivery rate, R 1 (unitless). A head-to-head comparison with R 1 derived from [11C]PiB scans was performed. Grouped differences in R 1 were evaluated among CN, MCI, and AD subjects. Results: Regional K 1 values suggested a relatively high extraction fraction. R 1 estimated noninvasively from simplified reference tissue model 2 agreed well with R 1 calculated indirectly from the blood-based compartment modeling (r = 0.99; mean difference, 0.024 ± 0.027), suggesting that robust estimates were obtained. R 1 measurements obtained with [18F]MK6240 correlated strongly and overall agreed well with those obtained from [11C]PiB (r = 0.93; mean difference, -0.001 ± 0.068). Statistically significant differences were observed in regional R 1 measurements among CN, MCI, and AD subjects, notably in the temporal and parietal cortices. Conclusion: Our results provide evidence that the early phase of [18F]MK6240 images may be used to derive a useful index of cerebral perfusion. The early and late phases of a [18F]MK6240 dynamic acquisition may thus offer complementary information about the pathophysiologic mechanisms of the disease.
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Affiliation(s)
- Nicolas J Guehl
- Gordon Center for Medical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts;
| | - Maeva Dhaynaut
- Gordon Center for Medical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Bernard J Hanseeuw
- Gordon Center for Medical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
- Department of Neurology, Cliniques Universitaires Saint-Luc, Université Catholique de Louvain, Brussels, Belgium; and
| | - Sung-Hyun Moon
- Gordon Center for Medical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Cristina Lois
- Gordon Center for Medical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Emma Thibault
- Gordon Center for Medical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Jessie Fanglu Fu
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Julie C Price
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Keith A Johnson
- Gordon Center for Medical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Georges El Fakhri
- Gordon Center for Medical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Marc D Normandin
- Gordon Center for Medical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
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25
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Tiss A, Marin T, Chemli Y, Spangler-Bickell M, Gong K, Lois C, Petibon Y, Landes V, Grogg K, Normandin M, Becker A, Thibault E, Johnson K, Fakhri GE, Ouyang J. Impact of motion correction on [ 18F]-MK6240 tau PET imaging. Phys Med Biol 2023; 68:10.1088/1361-6560/acd161. [PMID: 37116511 PMCID: PMC10278956 DOI: 10.1088/1361-6560/acd161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Accepted: 04/28/2023] [Indexed: 04/30/2023]
Abstract
Objective. Positron emission tomography (PET) imaging of tau deposition using [18F]-MK6240 often involves long acquisitions in older subjects, many of whom exhibit dementia symptoms. The resulting unavoidable head motion can greatly degrade image quality. Motion increases the variability of PET quantitation for longitudinal studies across subjects, resulting in larger sample sizes in clinical trials of Alzheimer's disease (AD) treatment.Approach. After using an ultra-short frame-by-frame motion detection method based on the list-mode data, we applied an event-by-event list-mode reconstruction to generate the motion-corrected images from 139 scans acquired in 65 subjects. This approach was initially validated in two phantoms experiments against optical tracking data. We developed a motion metric based on the average voxel displacement in the brain to quantify the level of motion in each scan and consequently evaluate the effect of motion correction on images from studies with substantial motion. We estimated the rate of tau accumulation in longitudinal studies (51 subjects) by calculating the difference in the ratio of standard uptake values in key brain regions for AD. We compared the regions' standard deviations across subjects from motion and non-motion-corrected images.Main results. Individually, 14% of the scans exhibited notable motion quantified by the proposed motion metric, affecting 48% of the longitudinal datasets with three time points and 25% of all subjects. Motion correction decreased the blurring in images from scans with notable motion and improved the accuracy in quantitative measures. Motion correction reduced the standard deviation of the rate of tau accumulation by -49%, -24%, -18%, and -16% in the entorhinal, inferior temporal, precuneus, and amygdala regions, respectively.Significance. The list-mode-based motion correction method is capable of correcting both fast and slow motion during brain PET scans. It leads to improved brain PET quantitation, which is crucial for imaging AD.
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Affiliation(s)
- Amal Tiss
- Gordon Center for Medical Imaging, Department of Imaging, Massachusetts General Hospital, Boston, MA, USA
- Harvard Medical School, Boston MA 02115, USA
| | - Thibault Marin
- Gordon Center for Medical Imaging, Department of Imaging, Massachusetts General Hospital, Boston, MA, USA
- Harvard Medical School, Boston MA 02115, USA
| | - Yanis Chemli
- Gordon Center for Medical Imaging, Department of Imaging, Massachusetts General Hospital, Boston, MA, USA
- Department of Image, Data & Signal, LTCI, Télécom Paris, Institut Polytechnique de Paris, France
| | | | - Kuang Gong
- Gordon Center for Medical Imaging, Department of Imaging, Massachusetts General Hospital, Boston, MA, USA
- Harvard Medical School, Boston MA 02115, USA
| | - Cristina Lois
- Gordon Center for Medical Imaging, Department of Imaging, Massachusetts General Hospital, Boston, MA, USA
- Harvard Medical School, Boston MA 02115, USA
| | - Yoann Petibon
- Gordon Center for Medical Imaging, Department of Imaging, Massachusetts General Hospital, Boston, MA, USA
- Harvard Medical School, Boston MA 02115, USA
| | | | - Kira Grogg
- Gordon Center for Medical Imaging, Department of Imaging, Massachusetts General Hospital, Boston, MA, USA
- Harvard Medical School, Boston MA 02115, USA
| | - Marc Normandin
- Gordon Center for Medical Imaging, Department of Imaging, Massachusetts General Hospital, Boston, MA, USA
- Harvard Medical School, Boston MA 02115, USA
| | - Alex Becker
- Gordon Center for Medical Imaging, Department of Imaging, Massachusetts General Hospital, Boston, MA, USA
- Harvard Medical School, Boston MA 02115, USA
- Department of Neurology, Massachusetts General Hospital, Boston, MA, USA
| | - Emma Thibault
- Gordon Center for Medical Imaging, Department of Imaging, Massachusetts General Hospital, Boston, MA, USA
- Harvard Medical School, Boston MA 02115, USA
- Department of Neurology, Massachusetts General Hospital, Boston, MA, USA
| | - Keith Johnson
- Gordon Center for Medical Imaging, Department of Imaging, Massachusetts General Hospital, Boston, MA, USA
- Harvard Medical School, Boston MA 02115, USA
- Department of Neurology, Massachusetts General Hospital, Boston, MA, USA
| | - Georges El Fakhri
- Gordon Center for Medical Imaging, Department of Imaging, Massachusetts General Hospital, Boston, MA, USA
- Harvard Medical School, Boston MA 02115, USA
| | - Jinsong Ouyang
- Gordon Center for Medical Imaging, Department of Imaging, Massachusetts General Hospital, Boston, MA, USA
- Harvard Medical School, Boston MA 02115, USA
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26
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Turkman N, Xu S, Huang CH, Eyermann C, Salino J, Khan P. High-Contrast PET Imaging with [ 18F]NT160, a Class-IIa Histone Deacetylase Probe for In Vivo Imaging of Epigenetic Machinery in the Central Nervous System. J Med Chem 2023; 66:5611-5621. [PMID: 37068265 PMCID: PMC10150721 DOI: 10.1021/acs.jmedchem.2c02064] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Indexed: 04/19/2023]
Abstract
We utilized positron emission tomography (PET) imaging in vivo to map the spatiotemporal biodistribution/expression of class-IIa histone deacetylases (class-IIa HDACs) in the central nervous system (CNS). Herein we report an improved radiosynthesis of [18F]NT160 using 4-hydroxy-TEMPO which led to a significant improvement in radiochemical yield and molar activity. PET imaging with [18F]NT160, a highly potent class-IIa HDAC inhibitor, led to high-quality and high-contrast images of the brain. [18F]NT160 displayed excellent pharmacokinetic and imaging characteristics: brain uptake is high in gray matter regions, tissue kinetics are appropriate for a 18F-tracer, and specific binding for class-IIa HDACs is demonstrated by self-blockade. Higher uptake with [18F]NT160 was observed in the hippocampus, thalamus, and cortex while the uptake in the cerebellum was relatively low. Overall, our current studies with [18F]NT160 will likely facilitate the development and clinical translation of PET tracers for imaging of class-IIa HDACs biodistribution/expression in cancer and the CNS.
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Affiliation(s)
- Nashaat Turkman
- Stony
Brook Cancer Center, Stony Brook, Long Island, New York 11794, United States
- Department
of Radiology, School of Medicine, Stony
Brook University, Long Island, New York 11794, United States
- Department
of Biomedical Engineering, Stony Brook University, Long Island, New York 11794, United States
| | - Sulan Xu
- Stony
Brook Cancer Center, Stony Brook, Long Island, New York 11794, United States
- Department
of Radiology, School of Medicine, Stony
Brook University, Long Island, New York 11794, United States
| | - Chun-Han Huang
- Stony
Brook Cancer Center, Stony Brook, Long Island, New York 11794, United States
- Department
of Radiology, School of Medicine, Stony
Brook University, Long Island, New York 11794, United States
- Department
of Biomedical Engineering, Stony Brook University, Long Island, New York 11794, United States
| | - Christopher Eyermann
- Department
of Radiology, School of Medicine, Stony
Brook University, Long Island, New York 11794, United States
- Department
of Surgery, School of Medicine, Stony Brook
University, Long Island, New York 11794, United States
| | - Julia Salino
- Stony
Brook Cancer Center, Stony Brook, Long Island, New York 11794, United States
- Department
of Radiology, School of Medicine, Stony
Brook University, Long Island, New York 11794, United States
| | - Palwasha Khan
- Stony
Brook Cancer Center, Stony Brook, Long Island, New York 11794, United States
- Department
of Radiology, School of Medicine, Stony
Brook University, Long Island, New York 11794, United States
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27
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Gholampour M, Seradj H, Sakhteman A. Structure-Selectivity Relationship Prediction of Tau Imaging Tracers Using Machine Learning-Assisted QSAR Models and Interaction Fingerprint Map. ACS Chem Neurosci 2023. [PMID: 37037183 DOI: 10.1021/acschemneuro.3c00038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/12/2023] Open
Abstract
Protein aggregates composed of tau fibrils are major pathologic findings in different tauopathies. An ideal agent for imaging tau fibrils must be highly selective. The molecular basis for the binding of current available compounds to tau aggregates is not well understood. Herein, we provide insights into previously studied positron emission tomography tracers using various computational methods, including machine learning-based quantitative structure-activity relationship (QSAR) classification, docking, and molecular dynamics (MD) simulations to investigate the structural basis of selective tau aggregate binding for potential compounds. The QSAR classification model based on the Random Forest algorithm with an accuracy of 96.6% for the selective and 97.6% for the nonselective class of compounds revealed essential selective moieties. The combination of molecular docking, MD simulations, and molecular mechanics Poisson-Boltzmann surface area (MM/PBSA) binding free-energy calculation showed superior binding energy of ligand 63 toward tau and PHF6, a key hexapeptide in tau aggregation, as the most selective compound in the data set. Dissecting the binding properties of ligand 63 and ligand 8 (the least selective compound) within tau and Aβ structures confirmed that these two compounds favor different binding sites of tau; however, the preferential binding site in Aβ was similar for both with lower binding energies calculated for ligand 8. Results revealed that the number of N-heterocycles, the position of nitrogen atoms, and the presence of tertiary amine are important components of selective binding moieties, and they should be maintained in molecules for selective binding to tau aggregates. The predicted structure-selectivity relationship will facilitate the rational design and further development of selective tau imaging agents.
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Affiliation(s)
- Maryam Gholampour
- Department of Medicinal Chemistry, Faculty of Pharmacy, Shiraz University of Medical Sciences, Shiraz 71468-64685, Iran
| | - Hassan Seradj
- Department of Medicinal Chemistry, Faculty of Pharmacy, Shiraz University of Medical Sciences, Shiraz 71468-64685, Iran
| | - Amirhossein Sakhteman
- Chair of Proteomics and Bioanalytics, Technical University of Munich (TUM), Freising 85354, Germany
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Seibyl JP, DuBois JM, Racine A, Collins J, Guo Q, Wooten D, Stage E, Cheng D, Gunn RN, Porat L, Whittington A, Kuo PH, Ichise M, Comley R, Martarello L, Salinas C. A Visual Interpretation Algorithm for Assessing Brain Tauopathy with 18F-MK-6240 PET. J Nucl Med 2023; 64:444-451. [PMID: 36175137 PMCID: PMC10071795 DOI: 10.2967/jnumed.122.264371] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Revised: 09/21/2022] [Accepted: 09/21/2022] [Indexed: 11/16/2022] Open
Abstract
In vivo characterization of pathologic deposition of tau protein in the human brain by PET imaging is a promising tool in drug development trials of Alzheimer disease (AD). 6-(fluoro-18F)-3-(1H-pyrrolo[2,3-c]pyridin-1-yl)isoquinolin-5-amine (18F-MK-6240) is a radiotracer with high selectivity and subnanomolar affinity for neurofibrillary tangles that shows favorable nonspecific brain penetration and excellent kinetic properties. The purpose of the present investigation was to develop a visual assessment method that provides both an overall assessment of brain tauopathy and regional characterization of abnormal tau deposition. Methods: 18F-MK-6240 scans from 102 participants (including cognitively normal volunteers and patients with AD or other neurodegenerative disorders) were reviewed by an expert nuclear medicine physician masked to each participant's diagnosis to identify common patterns of brain uptake. This initial visual read method was field-tested in a separate, nonoverlapping cohort of 102 participants, with 2 additional naïve readers trained on the method. Visual read outcomes were compared with semiquantitative assessments using volume-of-interest SUV ratio. Results: For the visual read, the readers assessed 8 gray-matter regions per hemisphere as negative (no abnormal uptake) or positive (1%-25% of the region involved, 25%-75% involvement, or >75% involvement) and then characterized the tau binding pattern as positive or negative for evidence of tau and, if positive, whether brain uptake was in an AD pattern. The readers demonstrated agreement 94% of the time for overall positivity or negativity. Concordance on the determination of regional binary outcomes (negative or positive) showed agreement of 74.3% and a Fleiss κ of 0.912. Using clinical diagnosis as the ground truth, the readers demonstrated a sensitivity of 73%-79% and specificity of 91%-93%, with a combined reader-concordance sensitivity of 80% and specificity of 93%. The average SUV ratio in cortical regions showed a robust correlation with visually derived ratings of regional involvement (r = 0.73, P < 0.0001). Conclusion: We developed a visual read algorithm for 18F-MK-6240 PET offering determination of both scan positivity and the regional degree of cortical involvement. These cross-sectional results show strong interreader concordance on both binary and regional assessments of tau deposition, as well as good sensitivity and excellent specificity supporting use as a tool for clinical trials.
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Affiliation(s)
- John P Seibyl
- Institute for Neurodegenerative Disorders, New Haven, Connecticut;
- Invicro, New Haven, Connecticut
| | | | | | | | - Qi Guo
- AbbVie, North Chicago, Illinois
| | | | | | | | | | | | | | | | - Masanori Ichise
- National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
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Tissot C, Servaes S, Lussier FZ, Ferrari-Souza JP, Therriault J, Ferreira PCL, Bezgin G, Bellaver B, Leffa DT, Mathotaarachchi SS, Chamoun M, Stevenson J, Rahmouni N, Kang MS, Pallen V, Margherita-Poltronetti N, Wang YT, Fernandez-Arias J, Benedet AL, Zimmer ER, Soucy JP, Tudorascu DL, Cohen AD, Sharp M, Gauthier S, Massarweh G, Lopresti B, Klunk WE, Baker SL, Villemagne VL, Rosa-Neto P, Pascoal TA. The Association of Age-Related and Off-Target Retention with Longitudinal Quantification of [ 18F]MK6240 Tau PET in Target Regions. J Nucl Med 2023; 64:452-459. [PMID: 36396455 PMCID: PMC10071794 DOI: 10.2967/jnumed.122.264434] [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: 05/26/2022] [Revised: 09/21/2022] [Accepted: 09/21/2022] [Indexed: 11/18/2022] Open
Abstract
6-(fluoro-18F)-3-(1H-pyrrolo[2,3-c]pyridin-1-yl)isoquinolin-5-amine ([18F]MK6240) tau PET tracer quantifies the brain tau neurofibrillary tangle load in Alzheimer disease. The aims of our study were to test the stability of common reference region estimates in the cerebellum over time and across diagnoses and evaluate the effects of age-related and off-target retention on the longitudinal quantification of [18F]MK6240 in target regions. Methods: We assessed reference, target, age-related, and off-target regions in 125 individuals across the aging and Alzheimer disease spectrum with longitudinal [18F]MK6240 SUVs and SUV ratios (SUVRs) (mean ± SD, 2.25 ± 0.40 y of follow-up). We obtained SUVR from meninges, exhibiting frequent off-target retention with [18F]MK6240. Additionally, we compared tracer uptake between 37 cognitively unimpaired young (CUY) (mean age, 23.41 ± 3.33 y) and 27 cognitively unimpaired older (CU) adults (amyloid-β-negative and tau-negative, 58.50 ± 9.01 y) to identify possible nonvisually apparent, age-related signal. Two-tailed t testing and Pearson correlation testing were used to determine the difference between groups and associations between changes in region uptake, respectively. Results: Inferior cerebellar gray matter SUV did not differ on the basis of diagnosis and amyloid-β status, cross-sectionally and over time. [18F]MK6240 uptake significantly differed between CUY and CU adults in the putamen or pallidum (affecting ∼75% of the region) and in the Braak II region (affecting ∼35%). Changes in meningeal and putamen or pallidum SUVRs did not significantly differ from zero, nor did they vary across diagnostic groups. We did not observe significant correlations between longitudinal changes in age-related or meningeal off-target retention and changes in target regions, whereas changes in all target regions were strongly correlated. Conclusion: Inferior cerebellar gray matter was similar across diagnostic groups cross-sectionally and stable over time and thus was deemed a suitable reference region for quantification. Despite not being visually perceptible, [18F]MK6240 has age-related retention in subcortical regions, at a much lower magnitude but topographically colocalized with significant off-target signal of the first-generation tau tracers. The lack of correlation between changes in age-related or meningeal and target retention suggests little influence of possible off-target signals on longitudinal tracer quantification. Nevertheless, the age-related retention in the Braak II region needs to be further investigated. Future postmortem studies should elucidate the source of the newly reported age-related [18F]MK6240 signal, and in vivo studies should further explore its impact on tracer quantification.
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Affiliation(s)
- Cécile Tissot
- McGill University, Montreal, Quebec, Canada
- McGill University Research Center for Studies in Aging, Montreal, Quebec, Canada
- Departments of Psychiatry and Neurology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Stijn Servaes
- McGill University, Montreal, Quebec, Canada
- McGill University Research Center for Studies in Aging, Montreal, Quebec, Canada
| | - Firoza Z Lussier
- Departments of Psychiatry and Neurology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - João Pedro Ferrari-Souza
- Departments of Psychiatry and Neurology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
- Graduate Program in Biological Sciences: Biochemistry, Porto Alegre, Brazil
| | - Joseph Therriault
- McGill University, Montreal, Quebec, Canada
- McGill University Research Center for Studies in Aging, Montreal, Quebec, Canada
| | - Pâmela C L Ferreira
- Departments of Psychiatry and Neurology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Gleb Bezgin
- McGill University, Montreal, Quebec, Canada
- McGill University Research Center for Studies in Aging, Montreal, Quebec, Canada
| | - Bruna Bellaver
- Departments of Psychiatry and Neurology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
- Graduate Program in Biological Sciences: Biochemistry, Porto Alegre, Brazil
| | - Douglas Teixeira Leffa
- Departments of Psychiatry and Neurology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Sulantha S Mathotaarachchi
- McGill University, Montreal, Quebec, Canada
- McGill University Research Center for Studies in Aging, Montreal, Quebec, Canada
| | - Mira Chamoun
- McGill University, Montreal, Quebec, Canada
- McGill University Research Center for Studies in Aging, Montreal, Quebec, Canada
| | - Jenna Stevenson
- McGill University, Montreal, Quebec, Canada
- McGill University Research Center for Studies in Aging, Montreal, Quebec, Canada
| | - Nesrine Rahmouni
- McGill University, Montreal, Quebec, Canada
- McGill University Research Center for Studies in Aging, Montreal, Quebec, Canada
| | - Min Su Kang
- Artificial Intelligence and Computational Neurosciences Lab, Sunnybrook Research Institute, University of Toronto, Toronto, Ontario, Canada
- L.C. Campbell Cognitive Neurology Unit, Hurvitz Brain Sciences Program, Sunnybrook Research Institute, University of Toronto, Toronto, Ontario, Canada
| | - Vanessa Pallen
- McGill University, Montreal, Quebec, Canada
- McGill University Research Center for Studies in Aging, Montreal, Quebec, Canada
| | - Nina Margherita-Poltronetti
- McGill University, Montreal, Quebec, Canada
- McGill University Research Center for Studies in Aging, Montreal, Quebec, Canada
| | - Yi-Ting Wang
- McGill University, Montreal, Quebec, Canada
- McGill University Research Center for Studies in Aging, Montreal, Quebec, Canada
| | - Jaime Fernandez-Arias
- McGill University, Montreal, Quebec, Canada
- McGill University Research Center for Studies in Aging, Montreal, Quebec, Canada
| | | | - Eduardo R Zimmer
- Graduate Program in Biological Sciences: Biochemistry, Porto Alegre, Brazil
- Department of Pharmacology, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | | | - Dana L Tudorascu
- Departments of Psychiatry and Neurology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Annie D Cohen
- Departments of Psychiatry and Neurology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | | | - Serge Gauthier
- McGill University Research Center for Studies in Aging, Montreal, Quebec, Canada
- Douglas Mental Health Institute, Montreal, Quebec, Canada
| | - Gassan Massarweh
- Department of Radiochemistry, Montreal Neurological Institute, Montreal, Quebec, Canada
| | - Brian Lopresti
- Department of Radiology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania; and
| | - William E Klunk
- Departments of Psychiatry and Neurology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | | | - Victor L Villemagne
- Departments of Psychiatry and Neurology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Pedro Rosa-Neto
- McGill University, Montreal, Quebec, Canada
- McGill University Research Center for Studies in Aging, Montreal, Quebec, Canada
- Montreal Neurological Institute, Montreal, Quebec, Canada
- Douglas Mental Health Institute, Montreal, Quebec, Canada
| | - Tharick A Pascoal
- Departments of Psychiatry and Neurology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania;
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Kotari V, Southekal S, Navitsky M, Kennedy IA, Lu M, Morris A, Zimmer JA, Fleisher AS, Mintun MA, Devous MD, Pontecorvo MJ. Early tau detection in flortaucipir images: validation in autopsy-confirmed data and implications for disease progression. Alzheimers Res Ther 2023; 15:41. [PMID: 36855201 PMCID: PMC9972744 DOI: 10.1186/s13195-023-01160-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Accepted: 01/01/2023] [Indexed: 03/02/2023]
Abstract
BACKGROUND There is an increasing interest in utilizing tau PET to identify patients early in Alzheimer's disease (AD). In this work, a temporal lobe composite (Eτ) volume of interest (VOI) was evaluated in a longitudinal flortaucipir cohort and compared to a previously described global neocortical VOI. In a separate autopsy-confirmed study, the sensitivity of the Eτ VOI for identifying intermediate (B2) neurofibrillary tangle (NFT) pathology was evaluated. METHODS A total of 427 subjects received flortaucipir, florbetapir, MRI, and cognitive evaluation at baseline and 18 months. In a separate autopsy study, 67 subjects received ante-mortem flortaucipir scans, and neuropathological findings were recorded according to NIA-AA recommendations by two experts. Two VOIs: Eτ comprising FreeSurfer volumes (bilateral entorhinal cortex, fusiform, parahippocampal, and inferior temporal gyri) transformed to MNI space and a previously published global AD signature-weighted neocortical VOI (ADsignature) (Devous et al., J Nucl Med 59:937-43, 2018), were used to calculate SUVr relative to a white matter reference region (PERSI) (Southekal et al., J Nucl Med Off Publ Soc Nucl Med 59:944-51, 2018). SUVr cutoffs for positivity were determined based on a cohort of young, cognitively normal subjects. Subjects were grouped based on positivity on both VOIs (Eτ+/ADsignature+; Eτ+/ADsignature-; Eτ-/ADsignature-). Groupwise comparisons were performed for baseline SUVr, 18-month changes in SUVr, neurodegeneration, and cognition. For the autopsy study, the sensitivity of Eτ in identifying intermediate Braak pathology (B2) subjects was compared to that of AD signature-weighted neocortical VOI. The average surface maps of subjects in the Eτ+/ADsignature- group and B2 NFT scores were created for visual evaluation of uptake. RESULTS Sixty-four out of 390 analyzable subjects were identified as Eτ+/ADsignature-: 84% were Aβ+, 100% were diagnosed as MCI or AD, and 59% were APOE ε4 carriers. Consistent with the hypothesis that Eτ+/ADsignature- status reflects an early stage of AD, Eτ+/ADsignature- subjects deteriorated significantly faster than Eτ-/ADsignature- subjects, but significantly slower than Eτ+/ADsignature+ subjects, on most measures (i.e., change in ADsignature SUVr, Eτ ROI cortical thickness, and MMSE). The ADsignature VOI was selective for subjects who came to autopsy with a B3 NFT score. In the autopsy study, 12/15 B2 subjects (including 10/11 Braak IV) were Eτ+/ADsignature-. Surface maps showed that flortaucipir uptake was largely captured by the Eτ VOI regions in B2 subjects. CONCLUSION The Eτ VOI identified subjects with elevated temporal but not global tau (Eτ+/ADsignature-) that were primarily Aβ+, APOE ε4 carriers, and diagnosed as MCI or AD. Eτ+/ADsignature- subjects had greater accumulation of tau, greater atrophy, and higher decline on MMSE in 18 months compared to Eτ-/ADsignature- subjects. Finally, the Eτ VOI identified the majority of the intermediate NFT score subjects in an autopsy-confirmed study. As far as we know, this is the first study that presents a visualization of ante-mortem FTP retention patterns that at a group level agree with the neurofibrillary tangle staging scheme proposed by Braak. These findings suggest that the Eτ VOI may be sensitive for detecting impaired subjects early in the course of Alzheimer's disease.
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Affiliation(s)
- Vikas Kotari
- Eli Lilly and Company, Indianapolis, IN, 46285, USA.
| | - Sudeepti Southekal
- grid.417540.30000 0000 2220 2544Eli Lilly and Company, Indianapolis, IN 46285 USA
| | - Michael Navitsky
- grid.417540.30000 0000 2220 2544Eli Lilly and Company, Indianapolis, IN 46285 USA
| | - Ian A. Kennedy
- grid.417540.30000 0000 2220 2544Eli Lilly and Company, Indianapolis, IN 46285 USA
| | - Ming Lu
- grid.417540.30000 0000 2220 2544Eli Lilly and Company, Indianapolis, IN 46285 USA
| | - Amanda Morris
- grid.417540.30000 0000 2220 2544Eli Lilly and Company, Indianapolis, IN 46285 USA
| | - Jennifer Ann Zimmer
- grid.417540.30000 0000 2220 2544Eli Lilly and Company, Indianapolis, IN 46285 USA
| | - Adam S. Fleisher
- grid.417540.30000 0000 2220 2544Eli Lilly and Company, Indianapolis, IN 46285 USA
| | - Mark A. Mintun
- grid.417540.30000 0000 2220 2544Eli Lilly and Company, Indianapolis, IN 46285 USA
| | - Michael D. Devous
- grid.417540.30000 0000 2220 2544Eli Lilly and Company, Indianapolis, IN 46285 USA
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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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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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Hoenig MC, Drzezga A. Clear-headed into old age: Resilience and resistance against brain aging-A PET imaging perspective. J Neurochem 2023; 164:325-345. [PMID: 35226362 DOI: 10.1111/jnc.15598] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 02/18/2022] [Accepted: 02/22/2022] [Indexed: 11/28/2022]
Abstract
With the advances in modern medicine and the adaptation towards healthier lifestyles, the average life expectancy has doubled since the 1930s, with individuals born in the millennium years now carrying an estimated life expectancy of around 100 years. And even though many individuals around the globe manage to age successfully, the prevalence of aging-associated neurodegenerative diseases such as sporadic Alzheimer's disease has never been as high as nowadays. The prevalence of Alzheimer's disease is anticipated to triple by 2050, increasing the societal and economic burden tremendously. Despite all efforts, there is still no available treatment defeating the accelerated aging process as seen in this disease. Yet, given the advances in neuroimaging techniques that are discussed in the current Review article, such as in positron emission tomography (PET) or magnetic resonance imaging (MRI), pivotal insights into the heterogenous effects of aging-associated processes and the contribution of distinct lifestyle and risk factors already have and are still being gathered. In particular, the concepts of resilience (i.e. coping with brain pathology) and resistance (i.e. avoiding brain pathology) have more recently been discussed as they relate to mechanisms that are associated with the prolongation and/or even stop of the progressive brain aging process. Better understanding of the underlying mechanisms of resilience and resistance may one day, hopefully, support the identification of defeating mechanism against accelerating aging.
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Affiliation(s)
- Merle C Hoenig
- Research Center Juelich, Institute for Neuroscience and Medicine II, Molecular Organization of the Brain, Juelich, Germany.,Department of Nuclear Medicine, Faculty of Medicine, University Hospital Cologne, Cologne, Germany
| | - Alexander Drzezga
- Research Center Juelich, Institute for Neuroscience and Medicine II, Molecular Organization of the Brain, Juelich, Germany.,Department of Nuclear Medicine, Faculty of Medicine, University Hospital Cologne, Cologne, Germany.,German Center for Neurodegenerative Diseases, Bonn/Cologne, Germany
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Krishnadas N, Doré V, Robertson JS, Ward L, Fowler C, Masters CL, Bourgeat P, Fripp J, Villemagne VL, Rowe CC. Rates of regional tau accumulation in ageing and across the Alzheimer's disease continuum: an AIBL 18F-MK6240 PET study. EBioMedicine 2023; 88:104450. [PMID: 36709581 PMCID: PMC9900352 DOI: 10.1016/j.ebiom.2023.104450] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2022] [Revised: 12/15/2022] [Accepted: 01/10/2023] [Indexed: 01/28/2023] Open
Abstract
BACKGROUND Tau positron emission tomography (PET) imaging enables longitudinal observation of tau accumulation in Alzheimer's disease (AD). 18F-MK6240 is a high affinity tracer for the paired helical filaments of tau in AD, widely used in clinical trials, despite sparse longitudinal natural history data. We aimed to evaluate the natural history of tau accumulation, and the impact of disease stage and reference region on the magnitude and effect size of regional change. METHODS One hundred and eighty-four participants: 89 cognitively unimpaired (CU) beta-amyloid negative (Aβ-), 44 CU Aβ+, 51 cognitively impaired Aβ+ (26 with mild cognitive impairment [MCI] and 25 with dementia) had follow-up 18F-MK6240 PET for one to four years (median 1.48). Regional standardised uptake value ratios (SUVR) were generated. Two reference regions were examined: cerebellar cortex and eroded subcortical white matter. FINDINGS CU Aβ- participants had very low rates of tau accumulation in the mesial temporal lobe (MTL). In CU Aβ+, significantly higher rate of accumulation was seen in the MTL (particularly the amygdala), extending into the inferior temporal lobes. In MCI Aβ+, the rate of accumulation was greatest in the lateral temporal, parietal and lateral occipital cortex, and plateaued in the MTL. Accumulation was global in AD Aβ+, except for a plateau in the MTL. The eroded subcortical white matter reference region showed no significant advantage over the cerebellar cortex and appeared prone to spill-over in AD participants. Data fitting suggested approximately 15-20 years to accumulate tau to typical AD levels. INTERPRETATION Tau accumulation occurs slowly. Rates vary according to brain region, disease stage and tend to plateau at high levels. Rates of tau accumulation are best measured in the MTL and inferior temporal cortex in preclinical AD and in large neocortical areas, in MCI and AD. FUNDING NHMRC; Cerveau Technologies.
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Affiliation(s)
- Natasha Krishnadas
- Florey Department of Neurosciences & Mental Health, The University of Melbourne, Parkville, Victoria, 3052, Australia; Department of Molecular Imaging & Therapy, Austin Health, Heidelberg, Victoria, 3084, Australia.
| | - Vincent Doré
- Department of Molecular Imaging & Therapy, Austin Health, Heidelberg, Victoria, 3084, Australia; Health and Biosecurity Flagship, The Australian eHealth Research Centre, Melbourne, Victoria, Australia
| | - Joanne S Robertson
- Florey Institute of Neurosciences & Mental Health, Parkville, Victoria, 3010, Australia
| | - Larry Ward
- Florey Institute of Neurosciences & Mental Health, Parkville, Victoria, 3010, Australia
| | - Christopher Fowler
- Florey Institute of Neurosciences & Mental Health, Parkville, Victoria, 3010, Australia
| | - Colin L Masters
- Florey Institute of Neurosciences & Mental Health, Parkville, Victoria, 3010, Australia
| | - Pierrick Bourgeat
- Health and Biosecurity Flagship, The Australian eHealth Research Centre, Brisbane, Queensland, Australia
| | - Jurgen Fripp
- Health and Biosecurity Flagship, The Australian eHealth Research Centre, Brisbane, Queensland, Australia
| | | | - Christopher C Rowe
- Florey Department of Neurosciences & Mental Health, The University of Melbourne, Parkville, Victoria, 3052, Australia; Department of Molecular Imaging & Therapy, Austin Health, Heidelberg, Victoria, 3084, Australia; Florey Institute of Neurosciences & Mental Health, Parkville, Victoria, 3010, Australia
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Loftus JR, Puri S, Meyers SP. Multimodality imaging of neurodegenerative disorders with a focus on multiparametric magnetic resonance and molecular imaging. Insights Imaging 2023; 14:8. [PMID: 36645560 PMCID: PMC9842851 DOI: 10.1186/s13244-022-01358-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Accepted: 12/13/2022] [Indexed: 01/17/2023] Open
Abstract
Neurodegenerative diseases afflict a large number of persons worldwide, with the prevalence and incidence of dementia rapidly increasing. Despite their prevalence, clinical diagnosis of dementia syndromes remains imperfect with limited specificity. Conventional structural-based imaging techniques also lack the accuracy necessary for confident diagnosis. Multiparametric magnetic resonance imaging and molecular imaging provide the promise of improving specificity and sensitivity in the diagnosis of neurodegenerative disease as well as therapeutic monitoring of monoclonal antibody therapy. This educational review will briefly focus on the epidemiology, clinical presentation, and pathologic findings of common and uncommon neurodegenerative diseases. Imaging features of each disease spanning from conventional magnetic resonance sequences to advanced multiparametric methods such as resting-state functional magnetic resonance imaging and arterial spin labeling imaging will be described in detail. Additionally, the review will explore the findings of each diagnosis on molecular imaging including single-photon emission computed tomography and positron emission tomography with a variety of clinically used and experimental radiotracers. The literature and clinical cases provided demonstrate the power of advanced magnetic resonance imaging and molecular techniques in the diagnosis of neurodegenerative diseases and areas of future and ongoing research. With the advent of combined positron emission tomography/magnetic resonance imaging scanners, hybrid protocols utilizing both techniques are an attractive option for improving the evaluation of neurodegenerative diseases.
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Affiliation(s)
- James Ryan Loftus
- grid.412750.50000 0004 1936 9166Department of Imaging Sciences, University of Rochester Medical Center, 601 Elmwood Ave, Rochester, NY 14642 USA
| | - Savita Puri
- grid.412750.50000 0004 1936 9166Department of Imaging Sciences, University of Rochester Medical Center, 601 Elmwood Ave, Rochester, NY 14642 USA
| | - Steven P. Meyers
- grid.412750.50000 0004 1936 9166Department of Imaging Sciences, University of Rochester Medical Center, 601 Elmwood Ave, Rochester, NY 14642 USA
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Shuping JL, Matthews DC, Adamczuk K, Scott D, Rowe CC, Kreisl WC, Johnson SC, Lukic AS, Johnson KA, Rosa‐Neto P, Andrews RD, Van Laere K, Cordes L, Ward L, Wilde CL, Barakos J, Purcell DD, Devanand DP, Stern Y, Luchsinger JA, Sur C, Price JC, Brickman AM, Klunk WE, Boxer AL, Mathotaarachchi SS, Lao PJ, Evelhoch JL. Development, initial validation, and application of a visual read method for [ 18F]MK-6240 tau PET. ALZHEIMER'S & DEMENTIA (NEW YORK, N. Y.) 2023; 9:e12372. [PMID: 36873926 PMCID: PMC9983143 DOI: 10.1002/trc2.12372] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Revised: 12/14/2022] [Accepted: 12/15/2022] [Indexed: 02/15/2023]
Abstract
Background The positron emission tomography (PET) radiotracer [18F]MK-6240 exhibits high specificity for neurofibrillary tangles (NFTs) of tau protein in Alzheimer's disease (AD), high sensitivity to medial temporal and neocortical NFTs, and low within-brain background. Objectives were to develop and validate a reproducible, clinically relevant visual read method supporting [18F]MK-6240 use to identify and stage AD subjects versus non-AD and controls. Methods Five expert readers used their own methods to assess 30 scans of mixed diagnosis (47% cognitively normal, 23% mild cognitive impairment, 20% AD, 10% traumatic brain injury) and provided input regarding regional and global positivity, features influencing assessment, confidence, practicality, and clinical relevance. Inter-reader agreement and concordance with quantitative values were evaluated to confirm that regions could be read reliably. Guided by input regarding clinical applicability and practicality, read classifications were defined. The readers read the scans using the new classifications, establishing by majority agreement a gold standard read for those scans. Two naïve readers were trained and read the 30-scan set, providing initial validation. Inter-rater agreement was further tested by two trained independent readers in 131 scans. One of these readers used the same method to read a full, diverse database of 1842 scans; relationships between read classification, clinical diagnosis, and amyloid status as available were assessed. Results Four visual read classifications were determined: no uptake, medial temporal lobe (MTL) only, MTL and neocortical uptake, and uptake outside MTL. Inter-rater kappas were 1.0 for the naïve readers gold standard scans read and 0.98 for the independent readers 131-scan read. All scans in the full database could be classified; classification frequencies were concordant with NFT histopathology literature. Discussion This four-class [18F]MK-6240 visual read method captures the presence of medial temporal signal, neocortical expansion associated with disease progression, and atypical distributions that may reflect different phenotypes. The method demonstrates excellent trainability, reproducibility, and clinical relevance supporting clinical use. Highlights A visual read method has been developed for [18F]MK-6240 tau positron emission tomography.The method is readily trainable and reproducible, with inter-rater kappas of 0.98.The read method has been applied to a diverse set of 1842 [18F]MK-6240 scans.All scans from a spectrum of disease states and acquisitions could be classified.Read classifications are consistent with histopathological neurofibrillary tangle staging literature.
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Affiliation(s)
| | | | | | | | - Christopher C. Rowe
- Department of Molecular Imaging and TherapyAustin HealthMelbourneVictoriaAustralia
- Florey Department of Neuroscience and Mental HealthThe University of MelbourneMelbourneVictoriaAustralia
| | - William C. Kreisl
- Department of NeurologyThe Taub Institute for Research on Alzheimer's Disease and the Aging BrainColumbia UniversityNew YorkNew YorkUSA
- Columbia University Irving Medical CenterVagelos College of Physicians and SurgeonsNew YorkNew YorkUSA
| | - Sterling C. Johnson
- Department of MedicineDivision of GeriatricsAlzheimer's Disease Research Center, University of WisconsinMadisonWisconsinUSA
| | | | - Keith A. Johnson
- The Gordon Center for Medical ImagingDepartment of NeurologyCenter for Alzheimer Research and TreatmentBrigham and Women's HospitalBostonMassachusettsUSA
- Department of RadiologyAthinoula A. Martinos Center for Biomedical ImagingMassachusetts General HospitalHarvard Medical SchoolCharlestownMassachusettsUSA
| | - Pedro Rosa‐Neto
- Montreal Neurological InstituteMcGill UniversityMontréalQuebecCanada
| | | | - Koen Van Laere
- Nuclear Medicine and Molecular ImagingDepartment of Imaging and Pathology KU LeuvenLeuvenBelgium
| | | | - Larry Ward
- Florey Department of Neuroscience and Mental HealthThe University of MelbourneMelbourneVictoriaAustralia
| | | | | | | | - Davangere P. Devanand
- Department of NeurologyThe Taub Institute for Research on Alzheimer's Disease and the Aging BrainColumbia UniversityNew YorkNew YorkUSA
- Columbia University Irving Medical CenterVagelos College of Physicians and SurgeonsNew YorkNew YorkUSA
- Department of PsychiatryColumbia University Irving Medical CenterNew YorkNew YorkUSA
| | - Yaakov Stern
- Department of NeurologyThe Taub Institute for Research on Alzheimer's Disease and the Aging BrainColumbia UniversityNew YorkNew YorkUSA
- Columbia University Irving Medical CenterVagelos College of Physicians and SurgeonsNew YorkNew YorkUSA
- Department of PsychiatryColumbia University Irving Medical CenterNew YorkNew YorkUSA
- Department of NeurologyGertrude H. Sergievsky CenterColumbia UniversityNew YorkNew YorkUSA
| | - Jose A. Luchsinger
- Columbia University Irving Medical CenterVagelos College of Physicians and SurgeonsNew YorkNew YorkUSA
- Department of Medicine and EpidemiologyColumbia University Irving Medical CenterNew York, NY, 10032 USA For Dr. LuchsingerUSA
| | | | - Julie C. Price
- Department of RadiologyAthinoula A. Martinos Center for Biomedical ImagingMassachusetts General HospitalHarvard Medical SchoolCharlestownMassachusettsUSA
| | - Adam M. Brickman
- Department of NeurologyThe Taub Institute for Research on Alzheimer's Disease and the Aging BrainColumbia UniversityNew YorkNew YorkUSA
- Columbia University Irving Medical CenterVagelos College of Physicians and SurgeonsNew YorkNew YorkUSA
- Department of NeurologyGertrude H. Sergievsky CenterColumbia UniversityNew YorkNew YorkUSA
| | - William E. Klunk
- Department of PsychiatryUniversity of PittsburghPittsburghPennsylvaniaUSA
| | - Adam L. Boxer
- Department of NeurologyMemory and Aging CenterUniversity of CaliforniaSan FranciscoCaliforniaUSA
| | | | - Patrick J. Lao
- Department of NeurologyThe Taub Institute for Research on Alzheimer's Disease and the Aging BrainColumbia UniversityNew YorkNew YorkUSA
- Columbia University Irving Medical CenterVagelos College of Physicians and SurgeonsNew YorkNew YorkUSA
- Department of NeurologyGertrude H. Sergievsky CenterColumbia UniversityNew YorkNew YorkUSA
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Zhang J, Liu Q, Zhang H, Dai M, Song Q, Yang D, Wu G, Chen M. Uncovering the System Vulnerability and Criticality of Human Brain Under Dynamical Neuropathological Events in Alzheimer's Disease. J Alzheimers Dis 2023; 95:1201-1219. [PMID: 37661878 PMCID: PMC11177206 DOI: 10.3233/jad-230027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/05/2023]
Abstract
BACKGROUND Despite the striking efforts in investigating neurobiological factors behind the acquisition of amyloid-β (A), protein tau (T), and neurodegeneration ([N]) biomarkers, the mechanistic pathways of how AT[N] biomarkers spreading throughout the brain remain elusive. OBJECTIVE To disentangle the massive heterogeneities in Alzheimer's disease (AD) progressions and identify vulnerable/critical brain regions to AD pathology. METHODS In this work, we characterized the interaction of AT[N] biomarkers and their propagation across brain networks using a novel bistable reaction-diffusion model, which allows us to establish a new systems biology underpinning of AD progression. We applied our model to large-scale longitudinal neuroimages from the ADNI database and studied the systematic vulnerability and criticality of brains. RESULTS Our model yields long term prediction that is statistically significant linear correlated with temporal imaging data, produces clinically consistent risk prediction, and captures the Braak-like spreading pattern of AT[N] biomarkers in AD development. CONCLUSIONS Our major findings include (i) tau is a stronger indicator of regional risk compared to amyloid, (ii) temporal lobe exhibits higher vulnerability to AD-related pathologies, (iii) proposed critical brain regions outperform hub nodes in transmitting disease factors across the brain, and (iv) comparing the spread of neuropathological burdens caused by amyloid-β and tau diffusions, disruption of metabolic balance is the most determinant factor contributing to the initiation and progression of AD.
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Affiliation(s)
- Jingwen Zhang
- Department of Computer Science, Wake Forest University, Winston-Salem, NC, USA
| | - Qing Liu
- Department of Mathematics, University of North Georgia, Oakwood, GA, USA
| | - Haorui Zhang
- Department of Mathematics, University of North Georgia, Oakwood, GA, USA
| | - Michelle Dai
- Department of Biostatistics, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Qianqian Song
- Department of Cancer Biology, Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - Defu Yang
- Department of Psychiatry, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Guorong Wu
- Department of Psychiatry, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Department of Computer Science, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Minghan Chen
- Department of Computer Science, Wake Forest University, Winston-Salem, NC, USA
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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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39
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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: 10] [Impact Index Per Article: 5.0] [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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40
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Witek JA, Brooks AF, Scott PJH. Classics in Neuroimaging: Untangling the Role of Tau in Neurodegenerative Disorders Using Positron Emission Tomography. ACS Chem Neurosci 2022; 13:2778-2783. [PMID: 36112411 DOI: 10.1021/acschemneuro.2c00519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Imaging of misfolded proteins implicated in neurodegenerative disorders using positron emission tomography (PET) imaging has revolutionized dementia research. In this viewpoint, the development of radiotracers for tau PET is highlighted. We draw attention to key innovations that were essential to development of radiotracers for imaging tau, from early imaging agents, through the structure-activity relationship (SAR) studies required to minimize off-target binding of the newer probes in use today. We also highlight development of Tauvid, the first tau PET radiotracer approved by the US FDA for tau imaging in adult patients with cognitive impairment who are being evaluated for Alzheimer's disease.
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Affiliation(s)
- Jason A Witek
- Department of Radiology, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Allen F Brooks
- Department of Radiology, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Peter J H Scott
- Department of Radiology, University of Michigan, Ann Arbor, Michigan 48109, United States
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41
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Vanderlinden G, Ceccarini J, Vande Casteele T, Michiels L, Lemmens R, Triau E, Serdons K, Tournoy J, Koole M, Vandenbulcke M, Van Laere K. Spatial decrease of synaptic density in amnestic mild cognitive impairment follows the tau build-up pattern. Mol Psychiatry 2022; 27:4244-4251. [PMID: 35794185 DOI: 10.1038/s41380-022-01672-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Revised: 06/03/2022] [Accepted: 06/10/2022] [Indexed: 02/07/2023]
Abstract
Next to amyloid and tau, synaptic loss is a key pathological hallmark in Alzheimer's disease, closely related to cognitive dysfunction and neurodegeneration. Tau is thought to cause synaptic loss, but this has not been experimentally verified in vivo. In a 2-year follow-up study, dual tracer PET-MR was performed in 12 amnestic MCI patients using 18F-MK-6240 for tau and 11C-UCB-J for SV2A as a proxy for synaptic density. Tau already accumulated in the neocortex at baseline with progression in Braak V/VI at follow-up. While synaptic loss was limited to limbic regions at baseline, it followed the specific tau pattern to stage IV/V regions two years later, indicating that tau spread might drive synaptic vulnerability. Moreover, synaptic density changes correlated to changes in cognitive function. This study shows for the first time in vivo that synaptic loss regionally follows tau accumulation after two years, providing a disease-modifying window of opportunity for (combined) tau-targeting therapies.
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Affiliation(s)
- Greet Vanderlinden
- Nuclear Medicine and Molecular Imaging, Imaging Pathology, KU Leuven, Leuven, Belgium.
| | - Jenny Ceccarini
- Nuclear Medicine and Molecular Imaging, Imaging Pathology, KU Leuven, Leuven, Belgium
| | - Thomas Vande Casteele
- Neuropsychiatry, Department of Neurosciences, Leuven Brain Institute, KU Leuven, Leuven, Belgium
| | - Laura Michiels
- Department of Neurosciences, KU Leuven, Leuven, Belgium.,Department of Neurology, University Hospitals UZ Leuven, Leuven, Belgium.,VIB, Center for Brain & Disease Research, Laboratory of Neurobiology, Leuven, Belgium
| | - Robin Lemmens
- Department of Neurosciences, KU Leuven, Leuven, Belgium.,Department of Neurology, University Hospitals UZ Leuven, Leuven, Belgium.,VIB, Center for Brain & Disease Research, Laboratory of Neurobiology, Leuven, Belgium
| | - Eric Triau
- Private Practice Neurology, Leuven, Belgium
| | - Kim Serdons
- Department of Nuclear Medicine, University Hospitals UZ Leuven, Leuven, Belgium
| | - Jos Tournoy
- Department of Geriatric Medicine, University Hospitals UZ Leuven, Leuven, Belgium.,Department of Public Health and Primary Care, Gerontology and Geriatrics, KU Leuven, Leuven, Belgium
| | - Michel Koole
- Nuclear Medicine and Molecular Imaging, Imaging Pathology, KU Leuven, Leuven, Belgium
| | - Mathieu Vandenbulcke
- Neuropsychiatry, Department of Neurosciences, Leuven Brain Institute, KU Leuven, Leuven, Belgium.,Department of Old-Age Psychiatry, University Hospitals UZ Leuven, Leuven, Belgium
| | - Koen Van Laere
- Nuclear Medicine and Molecular Imaging, Imaging Pathology, KU Leuven, Leuven, Belgium.,Department of Nuclear Medicine, University Hospitals UZ Leuven, Leuven, Belgium
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42
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Zhou J, Benoit M, Sharoar MG. Recent advances in pre-clinical diagnosis of Alzheimer's disease. Metab Brain Dis 2022; 37:1703-1725. [PMID: 33900524 DOI: 10.1007/s11011-021-00733-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/02/2021] [Accepted: 04/05/2021] [Indexed: 11/26/2022]
Abstract
Alzheimer's disease (AD) is the most common dementia with currently no known cures or disease modifying treatments (DMTs), despite much time and effort from the field. Diagnosis and intervention of AD during the early pre-symptomatic phase of the disease is thought to be a more effective strategy. Therefore, the detection of biomarkers has emerged as a critical tool for monitoring the effect of new AD therapies, as well as identifying patients most likely to respond to treatment. The establishment of the amyloid/tau/neurodegeneration (A/T/N) framework in 2018 has codified the contexts of use of AD biomarkers in neuroimaging and bodily fluids for research and diagnostic purposes. Furthermore, a renewed drive for novel AD biomarkers and innovative methods of detection has emerged with the goals of adding additional insight to disease progression and discovery of new therapeutic targets. The use of biomarkers has accelerated the development of AD drugs and will bring new therapies to patients in need. This review highlights recent methods utilized to diagnose antemortem AD.
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Affiliation(s)
- John Zhou
- Department of Neuroscience, University of Connecticut Health, Farmington, CT, 06030, USA
- Molecular Medicine Program, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, OH, 44195, USA
| | - Marc Benoit
- Department of Neuroscience, University of Connecticut Health, Farmington, CT, 06030, USA
| | - Md Golam Sharoar
- Department of Neuroscience, University of Connecticut Health, Farmington, CT, 06030, USA.
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43
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Long-term test-retest of cerebral [18F]MK-6240 binding and longitudinal evaluation of extracerebral tracer uptake in healthy controls and amnestic MCI patients. Eur J Nucl Med Mol Imaging 2022; 49:4580-4588. [DOI: 10.1007/s00259-022-05907-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Accepted: 07/07/2022] [Indexed: 11/04/2022]
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44
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Mertens N, Michiels L, Vanderlinden G, Vandenbulcke M, Lemmens R, Van Laere K, Koole M. Impact of meningeal uptake and partial volume correction techniques on [ 18F]MK-6240 binding in aMCI patients and healthy controls. J Cereb Blood Flow Metab 2022; 42:1236-1246. [PMID: 35062837 PMCID: PMC9207493 DOI: 10.1177/0271678x221076023] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
[18F]MK-6240 is a second-generation tau PET-tracer to quantify neurofibrillary tangles in-vivo. However, individually variable levels of meningeal uptake induce spill-in-effects into the cortex, complicating [18F]MK-6240 PET quantification. Group SUVR differences between age-matched HC subgroups with varying extracerebral uptake (EC-low/mixed/high), and between aMCI and each HC subgroup were assessed without and with partial volume correction (PVC). Both Müller-Gartner (MG-)PVC and region-based voxelwise (RBV-)PVC, with the latter also correcting for extracerebral spill-in-effects, were implemented. Between HC groups, where no differences are to be expected, HC EC-high showed spill-in differences compared to HC EC-low when no PVC was applied while for MG-PVC, differences were reduced and, for RBV-PVC, no statistically significant differences were observed. Between aMCI and HC, cortical SUVR differences were statistically significant, both without and with PVC, but modulated by the varying meningeal uptake in HC subgroups when no PVC was applied. After applying PVC, correlations to clinical parameters improved and effect sizes between HC and aMCI increased, independent of the HC-subgroup. Therefore, appropriate PVC with correction for extracerebral spill-in-effects is recommended to minimize the impact of varying meningeal uptake on cortical differences between HC and aMCI.
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Affiliation(s)
- Nathalie Mertens
- Nuclear Medicine and Molecular Imaging, University Hospital and KU Leuven, Leuven, Belgium
| | - Laura Michiels
- Department of Neurosciences, Experimental Neurology, KU Leuven - University of Leuven, Leuven, Belgium.,VIB, Center for Brain & Disease Research, Laboratory of Neurobiology, Leuven, Belgium.,Department of Neurology, University Hospitals Leuven, Leuven, Belgium
| | - Greet Vanderlinden
- Nuclear Medicine and Molecular Imaging, University Hospital and KU Leuven, Leuven, Belgium
| | - Mathieu Vandenbulcke
- Department of Neurosciences, Experimental Neurology, KU Leuven - University of Leuven, Leuven, Belgium.,Old-Age Psychiatry, University Hospital and KU Leuven, Leuven, Belgium
| | - Robin Lemmens
- Department of Neurosciences, Experimental Neurology, KU Leuven - University of Leuven, Leuven, Belgium.,VIB, Center for Brain & Disease Research, Laboratory of Neurobiology, Leuven, Belgium.,Department of Neurology, University Hospitals Leuven, Leuven, Belgium
| | - Koen Van Laere
- Nuclear Medicine and Molecular Imaging, University Hospital and KU Leuven, Leuven, Belgium.,Division of Nuclear Medicine, University Hospitals Leuven, Belgium
| | - Michel Koole
- Nuclear Medicine and Molecular Imaging, University Hospital and KU Leuven, Leuven, Belgium
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45
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Li Y, Liu T, Cui M. Recent development in selective Tau tracers for PET imaging in the brain. CHINESE CHEM LETT 2022. [DOI: 10.1016/j.cclet.2022.03.024] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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46
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Therriault J, Pascoal TA, Lussier FZ, Tissot C, Chamoun M, Bezgin G, Servaes S, Benedet AL, Ashton NJ, Karikari TK, Lantero-Rodriguez J, Kunach P, Wang YT, Fernandez-Arias J, Massarweh G, Vitali P, Soucy JP, Saha-Chaudhuri P, Blennow K, Zetterberg H, Gauthier S, Rosa-Neto P. Biomarker modeling of Alzheimer's disease using PET-based Braak staging. NATURE AGING 2022; 2:526-535. [PMID: 37118445 PMCID: PMC10154209 DOI: 10.1038/s43587-022-00204-0] [Citation(s) in RCA: 80] [Impact Index Per Article: 40.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Accepted: 03/08/2022] [Indexed: 04/30/2023]
Abstract
Gold-standard diagnosis of Alzheimer's disease (AD) relies on histopathological staging systems. Using the topographical information from [18F]MK6240 tau positron-emission tomography (PET), we applied the Braak tau staging system to 324 living individuals. We used PET-based Braak stage to model the trajectories of amyloid-β, phosphorylated tau (pTau) in cerebrospinal fluid (pTau181, pTau217, pTau231 and pTau235) and plasma (pTau181 and pTau231), neurodegeneration and cognitive symptoms. We identified nonlinear AD biomarker trajectories corresponding to the spatial extent of tau-PET, with modest biomarker changes detectable by Braak stage II and significant changes occurring at stages III-IV, followed by plateaus. Early Braak stages were associated with isolated memory impairment, whereas Braak stages V-VI were incompatible with normal cognition. In 159 individuals with follow-up tau-PET, progression beyond stage III took place uniquely in the presence of amyloid-β positivity. Our findings support PET-based Braak staging as a framework to model the natural history of AD and monitor AD severity in living humans.
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Affiliation(s)
- Joseph Therriault
- Translational Neuroimaging Laboratory, McGill Research Centre for Studies in Aging, Douglas Mental Health Institute, Le Centre intégré universitaire de santé et de services sociaux (CIUSSS) de l'Ouest de l'Île de Montréal, Montreal, Quebec, Canada.
- Department of Neurology and Neurosurgery, Faculty of Medicine, McGill University, Montreal, Quebec, Canada.
| | - Tharick A Pascoal
- Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Firoza Z Lussier
- Translational Neuroimaging Laboratory, McGill Research Centre for Studies in Aging, Douglas Mental Health Institute, Le Centre intégré universitaire de santé et de services sociaux (CIUSSS) de l'Ouest de l'Île de Montréal, Montreal, Quebec, Canada
- Department of Neurology and Neurosurgery, Faculty of Medicine, McGill University, Montreal, Quebec, Canada
| | - Cécile Tissot
- Translational Neuroimaging Laboratory, McGill Research Centre for Studies in Aging, Douglas Mental Health Institute, Le Centre intégré universitaire de santé et de services sociaux (CIUSSS) de l'Ouest de l'Île de Montréal, Montreal, Quebec, Canada
- Department of Neurology and Neurosurgery, Faculty of Medicine, McGill University, Montreal, Quebec, Canada
| | - Mira Chamoun
- Translational Neuroimaging Laboratory, McGill Research Centre for Studies in Aging, Douglas Mental Health Institute, Le Centre intégré universitaire de santé et de services sociaux (CIUSSS) de l'Ouest de l'Île de Montréal, Montreal, Quebec, Canada
- Department of Neurology and Neurosurgery, Faculty of Medicine, McGill University, Montreal, Quebec, Canada
| | - Gleb Bezgin
- Translational Neuroimaging Laboratory, McGill Research Centre for Studies in Aging, Douglas Mental Health Institute, Le Centre intégré universitaire de santé et de services sociaux (CIUSSS) de l'Ouest de l'Île de Montréal, Montreal, Quebec, Canada
- Department of Neurology and Neurosurgery, Faculty of Medicine, McGill University, Montreal, Quebec, Canada
| | - Stijn Servaes
- Translational Neuroimaging Laboratory, McGill Research Centre for Studies in Aging, Douglas Mental Health Institute, Le Centre intégré universitaire de santé et de services sociaux (CIUSSS) de l'Ouest de l'Île de Montréal, Montreal, Quebec, Canada
- Department of Neurology and Neurosurgery, Faculty of Medicine, McGill University, Montreal, Quebec, Canada
| | - Andrea L Benedet
- Translational Neuroimaging Laboratory, McGill Research Centre for Studies in Aging, Douglas Mental Health Institute, Le Centre intégré universitaire de santé et de services sociaux (CIUSSS) de l'Ouest de l'Île de Montréal, Montreal, Quebec, Canada
- Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, Mölndal, Sweden
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Nicholas J Ashton
- Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, Mölndal, Sweden
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- King's College London, Institute of Psychiatry, Psychology and Neuroscience, Maurice Wohl Institute Clinical Neuroscience Institute, London, UK
- Biomedical Research Unit for Dementia at South London, NIHR Biomedical Research Centre for Mental Health and Maudsley NHS Foundation, London, UK
| | - Thomas K Karikari
- Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
- Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, Mölndal, Sweden
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Juan Lantero-Rodriguez
- Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, Mölndal, Sweden
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Peter Kunach
- Translational Neuroimaging Laboratory, McGill Research Centre for Studies in Aging, Douglas Mental Health Institute, Le Centre intégré universitaire de santé et de services sociaux (CIUSSS) de l'Ouest de l'Île de Montréal, Montreal, Quebec, Canada
- Department of Neurology and Neurosurgery, Faculty of Medicine, McGill University, Montreal, Quebec, Canada
| | - Yi-Ting Wang
- Translational Neuroimaging Laboratory, McGill Research Centre for Studies in Aging, Douglas Mental Health Institute, Le Centre intégré universitaire de santé et de services sociaux (CIUSSS) de l'Ouest de l'Île de Montréal, Montreal, Quebec, Canada
- Department of Neurology and Neurosurgery, Faculty of Medicine, McGill University, Montreal, Quebec, Canada
| | - Jaime Fernandez-Arias
- Translational Neuroimaging Laboratory, McGill Research Centre for Studies in Aging, Douglas Mental Health Institute, Le Centre intégré universitaire de santé et de services sociaux (CIUSSS) de l'Ouest de l'Île de Montréal, Montreal, Quebec, Canada
- Department of Neurology and Neurosurgery, Faculty of Medicine, McGill University, Montreal, Quebec, Canada
| | - Gassan Massarweh
- Department of Neurology and Neurosurgery, Faculty of Medicine, McGill University, Montreal, Quebec, Canada
| | - Paolo Vitali
- Department of Neurology and Neurosurgery, Faculty of Medicine, McGill University, Montreal, Quebec, Canada
| | - Jean-Paul Soucy
- Department of Neurology and Neurosurgery, Faculty of Medicine, McGill University, Montreal, Quebec, Canada
| | | | - Kaj Blennow
- Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, Mölndal, Sweden
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Henrik Zetterberg
- Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, Mölndal, Sweden
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- Department of Neurodegenerative Disease, UCL Institute of Neurology, Queen Square, London, UK
- UK Dementia Research Institute at UCL, London, UK
| | - Serge Gauthier
- Translational Neuroimaging Laboratory, McGill Research Centre for Studies in Aging, Douglas Mental Health Institute, Le Centre intégré universitaire de santé et de services sociaux (CIUSSS) de l'Ouest de l'Île de Montréal, Montreal, Quebec, Canada
- Department of Neurology and Neurosurgery, Faculty of Medicine, McGill University, Montreal, Quebec, Canada
| | - Pedro Rosa-Neto
- Translational Neuroimaging Laboratory, McGill Research Centre for Studies in Aging, Douglas Mental Health Institute, Le Centre intégré universitaire de santé et de services sociaux (CIUSSS) de l'Ouest de l'Île de Montréal, Montreal, Quebec, Canada.
- Department of Neurology and Neurosurgery, Faculty of Medicine, McGill University, Montreal, Quebec, Canada.
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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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MicroPET Imaging Assessment of Brain Tau and Amyloid Deposition in 6 × Tg Alzheimer’s Disease Model Mice. Int J Mol Sci 2022; 23:ijms23105485. [PMID: 35628296 PMCID: PMC9146140 DOI: 10.3390/ijms23105485] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 05/04/2022] [Accepted: 05/09/2022] [Indexed: 11/23/2022] Open
Abstract
Alzheimer’s disease (AD) is characterized by the deposition of extracellular amyloid plaques and intracellular accumulation of neurofibrillary tangles (NFT). Amyloid beta (Aβ) and tau imaging are widely used for diagnosing and monitoring AD in clinical settings. We evaluated the pathology of a recently developed 6 × Tg − AD (6 × Tg) mouse model by crossbreeding 5 × FAD mice with mice expressing mutant (P301L) tau protein using micro-positron emission tomography (PET) image analysis. PET studies were performed in these 6 × Tg mice using [18F]Flutemetamol, which is an amyloid PET radiotracer; [18F]THK5351 and [18F]MK6240, which are tau PET radiotracers; moreover, [18F]DPA714, which is a translocator protein (TSPO) radiotracer, and comparisons were made with age-matched mice of their respective parental strains. We compared group differences in standardized uptake value ratio (SUVR), kinetic parameters, biodistribution, and histopathology. [18F]Flutemetamol images showed prominent cortical uptake and matched well with 6E10 staining images from 2-month-old 6 × Tg mice. [18F]Flutemetamol images showed a significant correlation with [18F]DPA714 in the cortex and hippocampus. [18F]THK5351 images revealed prominent hippocampal uptake and matched well with AT8 immunostaining images in 4-month-old 6 × Tg mice. Moreover, [18F]THK5351 images were confirmed using [18F]MK6240, which revealed significant correlations in the cortex and hippocampus. Uptake of [18F]THK5351 or [18F]MK6240 was highly correlated with [18F]Flutemetamol in 4-month-old 6 × Tg mice. In conclusion, PET imaging revealed significant age-related uptake of Aβ, tau, and TSPO in 6 × Tg mice, which was highly correlated with age-dependent pathology.
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Blessing EM, Parekh A, Betensky RA, Babb J, Saba N, Debure L, Varga AW, Ayappa I, Rapoport DM, Butler TA, de Leon MJ, Wisniewski T, Lopresti BJ, Osorio RS. Association between lower body temperature and increased tau pathology in cognitively normal older adults. Neurobiol Dis 2022; 171:105748. [PMID: 35550158 DOI: 10.1016/j.nbd.2022.105748] [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: 01/04/2022] [Revised: 04/25/2022] [Accepted: 05/05/2022] [Indexed: 10/18/2022] Open
Abstract
BACKGROUND Preclinical studies suggest body temperature (Tb) and consequently brain temperature has the potential to bidirectionally interact with tau pathology in Alzheimer's Disease (AD). Tau phosphorylation is substantially increased by a small (<1 °C) decrease in temperature within the human physiological range, and thermoregulatory nuclei are affected by tau pathology early in the AD continuum. In this study we evaluated whether Tb (as a proxy for brain temperature) is cross-sectionally associated with clinically utilized markers of tau pathology in cognitively normal older adults. METHODS Tb was continuously measured with ingestible telemetry sensors for 48 h. This period included two nights of nocturnal polysomnography to delineate whether Tb during waking vs sleep is differentially associated with tau pathology. Tau phosphorylation was assessed with plasma and cerebrospinal fluid (CSF) tau phosphorylated at threonine 181 (P-tau), sampled the day following Tb measurement. In addition, neurofibrillary tangle (NFT) burden in early Braak stage regions was imaged with PET-MR using the [18F]MK-6240 radiotracer on average one month later. RESULTS Lower Tb was associated with increased NFT burden, as well as increased plasma and CSF P-tau levels (p < 0.05). NFT burden was associated with lower Tb during waking (p < 0.05) but not during sleep intervals. Plasma and CSF P-tau levels were highly correlated with each other (p < 0.05), and both variables were correlated with tau tangle radiotracer uptake (p < 0.05). CONCLUSIONS These results, the first available for human, suggest that lower Tb in older adults may be associated with increased tau pathology. Our findings add to the substantial preclinical literature associating lower body and brain temperature with tau hyperphosphorylation. CLINICAL TRIAL NUMBER NCT03053908.
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Affiliation(s)
- Esther M Blessing
- Department of Psychiatry, NYU Grossman School of Medicine, New York, NY 10016, United States of America.
| | - Ankit Parekh
- Mount Sinai Integrative Sleep Center, Division of Pulmonary, Critical Care, and Sleep Medicine, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029, United States of America.
| | - Rebecca A Betensky
- Department of NYU School of Global Public Health, New York, NY 10016, United States of America.
| | - James Babb
- Alzheimer's Disease Research Center, Department of Neurology, NYU Grossman School of Medicine, New York, NY 10016, United States of America.
| | - Natalie Saba
- Department of Psychiatry, NYU Grossman School of Medicine, New York, NY 10016, United States of America.
| | - Ludovic Debure
- Alzheimer's Disease Research Center, Department of Neurology, NYU Grossman School of Medicine, New York, NY 10016, United States of America.
| | - Andrew W Varga
- Mount Sinai Integrative Sleep Center, Division of Pulmonary, Critical Care, and Sleep Medicine, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029, United States of America.
| | - Indu Ayappa
- Mount Sinai Integrative Sleep Center, Division of Pulmonary, Critical Care, and Sleep Medicine, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029, United States of America.
| | - David M Rapoport
- Mount Sinai Integrative Sleep Center, Division of Pulmonary, Critical Care, and Sleep Medicine, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029, United States of America.
| | - Tracy A Butler
- Department of Neurology, Weill Cornell Medicine, New York, NY 10065, United States of America.
| | - Mony J de Leon
- Department of Neurology, Weill Cornell Medicine, New York, NY 10065, United States of America.
| | - Thomas Wisniewski
- Alzheimer's Disease Research Center, Department of Neurology, NYU Grossman School of Medicine, New York, NY 10016, United States of America.
| | - Brian J Lopresti
- Department of Radiology, University of Pittsburgh, Pittsburgh, PA 15213, United States of America.
| | - Ricardo S Osorio
- Department of Psychiatry, NYU Grossman School of Medicine, New York, NY 10016, United States of America; Alzheimer's Disease Research Center, Department of Neurology, NYU Grossman School of Medicine, New York, NY 10016, United States of America.
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50
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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; 23:5023. [PMID: 35563414 PMCID: PMC9103893 DOI: 10.3390/ijms23095023] [Citation(s) in RCA: 61] [Impact Index Per Article: 30.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [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
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