51
|
Beaurain M, Salabert AS, Ribeiro MJ, Arlicot N, Damier P, Le Jeune F, Demonet JF, Payoux P. Innovative Molecular Imaging for Clinical Research, Therapeutic Stratification, and Nosography in Neuroscience. Front Med (Lausanne) 2019; 6:268. [PMID: 31828073 PMCID: PMC6890558 DOI: 10.3389/fmed.2019.00268] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Accepted: 11/01/2019] [Indexed: 01/06/2023] Open
Abstract
Over the past few decades, several radiotracers have been developed for neuroimaging applications, especially in PET. Because of their low steric hindrance, PET radionuclides can be used to label molecules that are small enough to cross the blood brain barrier, without modifying their biological properties. As the use of 11C is limited by its short physical half-life (20 min), there has been an increasing focus on developing tracers labeled with 18F for clinical use. The first such tracers allowed cerebral blood flow and glucose metabolism to be measured, and the development of molecular imaging has since enabled to focus more closely on specific targets such as receptors, neurotransmitter transporters, and other proteins. Hence, PET and SPECT biomarkers have become indispensable for innovative clinical research. Currently, the treatment options for a number of pathologies, notably neurodegenerative diseases, remain only supportive and symptomatic. Treatments that slow down or reverse disease progression are therefore the subject of numerous studies, in which molecular imaging is proving to be a powerful tool. PET and SPECT biomarkers already make it possible to diagnose several neurological diseases in vivo and at preclinical stages, yielding topographic, and quantitative data about the target. As a result, they can be used for assessing patients' eligibility for new treatments, or for treatment follow-up. The aim of the present review was to map major innovative radiotracers used in neuroscience, and explain their contribution to clinical research. We categorized them according to their target: dopaminergic, cholinergic or serotoninergic systems, β-amyloid plaques, tau protein, neuroinflammation, glutamate or GABA receptors, or α-synuclein. Most neurological disorders, and indeed mental disorders, involve the dysfunction of one or more of these targets. Combinations of molecular imaging biomarkers can afford us a better understanding of the mechanisms underlying disease development over time, and contribute to early detection/screening, diagnosis, therapy delivery/monitoring, and treatment follow-up in both research and clinical settings.
Collapse
Affiliation(s)
- Marie Beaurain
- CHU de Toulouse, Toulouse, France.,ToNIC, Toulouse NeuroImaging Center, Inserm U1214, Toulouse, France
| | - Anne-Sophie Salabert
- CHU de Toulouse, Toulouse, France.,ToNIC, Toulouse NeuroImaging Center, Inserm U1214, Toulouse, France
| | - Maria Joao Ribeiro
- UMR 1253, iBrain, Université de Tours, Inserm, Tours, France.,Inserm CIC 1415, University Hospital, Tours, France.,CHRU Tours, Tours, France
| | - Nicolas Arlicot
- UMR 1253, iBrain, Université de Tours, Inserm, Tours, France.,Inserm CIC 1415, University Hospital, Tours, France.,CHRU Tours, Tours, France
| | - Philippe Damier
- Inserm U913, Neurology Department, University Hospital, Nantes, France
| | | | - Jean-François Demonet
- Leenards Memory Centre, Department of Clinical Neuroscience, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
| | - Pierre Payoux
- CHU de Toulouse, Toulouse, France.,ToNIC, Toulouse NeuroImaging Center, Inserm U1214, Toulouse, France
| |
Collapse
|
52
|
Chowdhury SR, Lu HP. Spontaneous Rupture and Entanglement of Human Neuronal Tau Protein Induced by Piconewton Compressive Force. ACS Chem Neurosci 2019; 10:4061-4067. [PMID: 31423763 DOI: 10.1021/acschemneuro.9b00295] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Mechanical force vector fluctuations in living cells can have a significant impact on protein behavior and functions. Here we report that a human tau protein tertiary structure can abruptly and spontaneously rupture, like a balloon, under biologically available piconewton compressive force, using a home-modified atomic force microscopy single-molecule manipulation. The rupture behavior is dependent on the physiological level of presence of ions, such as K+ and Mg2+. We observed rupture events in the presence of K+ but not in the presence of Mg2+ ions. We have also explored the entangled protein state formed following the events of the multiple and simultaneous protein ruptures under crowding. Crowded proteins simultaneously rupture and then spontaneously refold to an entangled folding state, different from either folded and unfolded states of the tau protein, which can be a plausible pathway for the tau protein aggregation that is related to a number of neurodegenerative diseases.
Collapse
Affiliation(s)
- S. Roy Chowdhury
- Department of Chemistry, Center for Photochemical Sciences, Bowling Green State University, Bowling Green, Ohio 43403, United States
| | - H. Peter Lu
- Department of Chemistry, Center for Photochemical Sciences, Bowling Green State University, Bowling Green, Ohio 43403, United States
| |
Collapse
|
53
|
AD molecular: Imaging tau aggregates with positron emissions tomography. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2019; 165:107-138. [PMID: 31481160 DOI: 10.1016/bs.pmbts.2019.07.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Pathologic aggregates of tau protein are observed in several neurodegenerative diseases and are used to diagnose and stage disease postmortem. Recent advances in positron emission tomography radioligands allow for the detection of aggregated tau proteins in living persons. This chapter describes the development and characterization of several positron emission tomography radioligands used to detect tau pathophysiology in vivo, and how these ligands are being used in clinical aging and neurodegenerative disease research with a focus on imaging tau aggregates in Alzheimer's disease.
Collapse
|
54
|
Huang YY, Chiu MJ, Yen RF, Tsai CL, Hsieh HY, Chiu CH, Wu CH, Hsin LW, Tzen KY, Cheng CY, Ma KH, Shiue CY. An one-pot two-step automated synthesis of [18F]T807 injection, its biodistribution in mice and monkeys, and a preliminary study in humans. PLoS One 2019; 14:e0217384. [PMID: 31260447 PMCID: PMC6602418 DOI: 10.1371/journal.pone.0217384] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Accepted: 05/11/2019] [Indexed: 12/22/2022] Open
Abstract
[18F]T807 is a potent tau protein imaging agent. In order to fulfill the demand from preclinical and clinical studies, we developed an automated one-pot two-step synthesis of this potent tau imaging agent and studied its stability, and dosimetry in mice and monkeys. We also conducted a preliminary study of this imaging agent in humans. Using this one-pot two-step method, the radiochemical yield (RCY) of [18F]T807 was 20.5 ± 6.1% (n = 15) at the end of bombardment (EOB) in a synthesis time of 70±5 min. The chemical and radiochemical purities were >90% and the specific activities were 151 ± 52 GBq/μmol. The quality of [18F]T807 synthesized by this method met the U.S. Pharmacopoeia (USP) criteria. The stability test showed that the [18F]T807 injection was stable at room temperature for up to 4 h after the end of synthesis (EOS). The estimated effective dose of the [18F]T807 injection extrapolated from monkeys was 19 μSv/MBq (n = 2), while the estimated effective doses of the [18F]T807 injection extrapolated from fasted and non-fasted mice were 123 ± 27 (n = 3) and 94 ± 19 (n = 4) μSv/MBq, respectively. This one-pot two-step automated method produced the [18F]T807 injection with high reproducibility and high quality. PET imaging and radiation dosimetry evaluation in mice and Formosan rock monkeys suggested that the [18F]T807 injection synthesized by this method is suitable for use in human PET imaging studies. Thus, this method could fulfill the demand for the [18F]T807 injection in both preclinical and clinical studies of tauopathies, especially for nearby study sites without cyclotrons.
Collapse
Affiliation(s)
- Ya-Yao Huang
- PET Center, Department of Nuclear Medicine, National Taiwan University Hospital, Taipei, Taiwan
| | - Ming-Jang Chiu
- Molecular Imaging Center, National Taiwan University, Taipei, Taiwan
- Departments of Neurology, National Taiwan University Hospital, Taipei, Taiwan
- Institute of Brain and Mind Sciences, College of Medicine, National Taiwan University, Zhongzheng Dist., Taipei, Taiwan
- Department of Psychology, National Taiwan University, Taipei, Taiwan
- Graduate Institute of Biomedical Engineering and Bio-informatics, National Taiwan University, Taipei, Taiwan
| | - Ruoh-Fang Yen
- PET Center, Department of Nuclear Medicine, National Taiwan University Hospital, Taipei, Taiwan
- Molecular Imaging Center, National Taiwan University, Taipei, Taiwan
- Department of Radiology, National Taiwan University College of Medicine, Taipei, Taiwan
| | - Chia-Ling Tsai
- PET Center, Department of Nuclear Medicine, National Taiwan University Hospital, Taipei, Taiwan
| | - Hao-Yu Hsieh
- School of Pharmacy, College of Medicine, National Taiwan University, Zhongzheng Dist., Taipei, Taiwan
| | - Ching-Hung Chiu
- PET Center, Department of Nuclear Medicine, National Taiwan University Hospital, Taipei, Taiwan
| | - Chi-Han Wu
- Molecular Imaging Center, National Taiwan University, Taipei, Taiwan
| | - Ling-Wei Hsin
- Molecular Imaging Center, National Taiwan University, Taipei, Taiwan
- School of Pharmacy, College of Medicine, National Taiwan University, Zhongzheng Dist., Taipei, Taiwan
| | - Kai-Yuan Tzen
- PET Center, Department of Nuclear Medicine, National Taiwan University Hospital, Taipei, Taiwan
- Molecular Imaging Center, National Taiwan University, Taipei, Taiwan
| | - Cheng-Yi Cheng
- PET Center, Department of Nuclear Medicine, Tri-Service General Hospital, Neihu, Taipei, Taiwan
| | - Kuo-Hsing Ma
- Department of Biology and Anatomy, National Defense Medical Center, Taipei, Taiwan
| | - Chyng-Yann Shiue
- PET Center, Department of Nuclear Medicine, National Taiwan University Hospital, Taipei, Taiwan
- Molecular Imaging Center, National Taiwan University, Taipei, Taiwan
- PET Center, Department of Nuclear Medicine, Tri-Service General Hospital, Neihu, Taipei, Taiwan
| |
Collapse
|
55
|
Watanabe H, Fukui K, Shimizu Y, Idoko Y, Nakamoto Y, Togashi K, Saji H, Ono M. Synthesis and biological evaluation of F-18 labeled tetrahydroisoquinoline derivatives targeting orexin 1 receptor. Bioorg Med Chem Lett 2019; 29:1620-1623. [DOI: 10.1016/j.bmcl.2019.04.044] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Revised: 04/17/2019] [Accepted: 04/26/2019] [Indexed: 12/31/2022]
|
56
|
De P, Bhattacharyya D, Roy K. Application of multilayered strategy for variable selection in QSAR modeling of PET and SPECT imaging agents as diagnostic agents for Alzheimer’s disease. Struct Chem 2019. [DOI: 10.1007/s11224-019-01376-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
57
|
Sala A, Perani D. Brain Molecular Connectivity in Neurodegenerative Diseases: Recent Advances and New Perspectives Using Positron Emission Tomography. Front Neurosci 2019; 13:617. [PMID: 31258466 PMCID: PMC6587303 DOI: 10.3389/fnins.2019.00617] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Accepted: 05/29/2019] [Indexed: 12/12/2022] Open
Abstract
Positron emission tomography (PET) represents a unique molecular tool to get in vivo access to a wide spectrum of biological and neuropathological processes, of crucial relevance for neurodegenerative conditions. Although most PET findings are based on massive univariate approaches, in the last decade the increasing interest in multivariate methods has paved the way to the assessment of unexplored cerebral features, spanning from resting state brain networks to whole-brain connectome properties. Currently, the combination of molecular neuroimaging techniques with multivariate connectivity methods represents one of the most powerful, yet still emerging, approach to achieve novel insights into the pathophysiology of neurodegenerative diseases. In this review, we will summarize the available evidence in the field of PET molecular connectivity, with the aim to provide an overview of how these studies may increase the understanding of the pathogenesis of neurodegenerative diseases, over and above "traditional" structural/functional connectivity studies. Considering the available evidence, a major focus will be represented by molecular connectivity studies using [18F]FDG-PET, today applied in the major neuropathological spectra, from amyloidopathies and tauopathies to synucleinopathies and beyond. Pioneering studies using PET tracers targeting brain neuropathology and neurotransmission systems for connectivity studies will be discussed, their strengths and limitations highlighted with reference to both applied methodology and results interpretation. The most common methods for molecular connectivity assessment will be reviewed, with particular emphasis on the available strategies to investigate molecular connectivity at the single-subject level, of potential relevance for not only research but also diagnostic purposes. Finally, we will highlight possible future perspectives in the field, with reference in particular to newly available PET tracers, which will expand the application of molecular connectivity to new, exciting, unforeseen possibilities.
Collapse
Affiliation(s)
- Arianna Sala
- Faculty of Medicine and Surgery, Vita-Salute San Raffaele University, Milan, Italy.,Division of Neuroscience, Faculty of Psychology, San Raffaele Scientific Institute (IRCCS), Milan, Italy
| | - Daniela Perani
- Division of Neuroscience, Faculty of Psychology, San Raffaele Scientific Institute (IRCCS), Milan, Italy.,Faculty of Psychology, Vita-Salute San Raffaele University, Milan, Italy.,Nuclear Medicine Unit, Faculty of Psychology, San Raffaele Hospital (IRCCS), Milan, Italy
| |
Collapse
|
58
|
Abstract
Purpose of Review Abnormal accumulation of tau protein is the main hallmark of tauopathies and is closely associated with neurodegeneration and cognitive impairment, whereas the advance in PET imaging provides a non-invasive detection of tau inclusions in the brain. In this review, we discuss the potential of PET imaging as a biomarker in tauopathies, the latest development of novel tau tracers with new clinical information that has been disclosed, and the opportunities for improving diagnosis and designing clinical trials in the future. Recent Findings In recent years, several first-generation tau PET tracers including [11C]PBB3, [18F]THK-5117, [18F]THK-5351 and [18F]AV-1451 have been developed and succeeded in imaging neurofibrillary pathology in vivo. Due to the common off-target binding and subcortical white matter uptake seen in the first-generation tracers, several research institutes and pharmaceutical companies have been working on developing second-generation tau PET tracers which exhibit higher binding affinity and selectivity. Summary Tau PET imaging is promising to serve as a biomarker to support differential diagnosis and monitor disease progression in many neurodegenerative diseases.
Collapse
Affiliation(s)
- Yi Ting Wang
- Neurology Imaging Unit, Division of Brain Sciences, Department of Medicine, Imperial College London, 1st Floor B Block, Hammersmith Hospital Campus, Du Cane Road, London, W12 0NN, UK
| | - Paul Edison
- Neurology Imaging Unit, Division of Brain Sciences, Department of Medicine, Imperial College London, 1st Floor B Block, Hammersmith Hospital Campus, Du Cane Road, London, W12 0NN, UK. .,Cardiff University, Cardiff, CF10 3AT, UK.
| |
Collapse
|
59
|
Yang F, Wang K, Zhou K, Dai B, Dai J, Liang Y, Cui M. Synthesis and bioevaluation of technetium-99 m / rhenium labeled phenylquinoxaline derivatives as Tau imaging probes. Eur J Med Chem 2019; 177:291-301. [PMID: 31158745 DOI: 10.1016/j.ejmech.2019.05.065] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Revised: 05/09/2019] [Accepted: 05/23/2019] [Indexed: 10/26/2022]
Abstract
Based on our previous research on the fluorinated phenylquinoxaline scaffold, in this study, different positions of N,N-dimethyl amino group, and alkyl linkers with various lengths were introduced into this scaffold to regulate their lipophilicity and binding affinity to Tau. Four novel 99mTc/Re complexes with diethyl iminodiacetate chelator were synthesized and evaluated as Tau imaging tracers in the brain of Alzheimer's disease. Their specific binding to neurofibrillary tangles was verified by in vitro fluorescence staining and further confirmed by the results of immunofluorescence staining on the same brain sections from AD patient and Tg-tau mice. From in vitro binding assay using recombinant Tau aggregates, complex 4.2 with 6-N(CH3)2 and longer carbon chain (n = 4) displayed the highest affinity (Kd = 59.95 nM). [99mTc]4.2 was achieved by the ligand exchange reaction between dicarboxylic precursor and [99mTc(CO)3(H2O)3]+ intermediate with radiochemical yield over 45%. Ex vivo biodistribution studies on normal ICR mice revealed that [99mTc]4.2 exhibited moderate initial brain uptake (0.61% ID/g) and more structure optimizations are still required to improve the blood-brain barrier permeability.
Collapse
Affiliation(s)
- Fan Yang
- Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing, 100875, China
| | - Kan Wang
- Hubei Key Laboratory of Cell Homeostasis, State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, 430072, China
| | - Kaixiang Zhou
- Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing, 100875, China
| | - Bin Dai
- Hubei Key Laboratory of Cell Homeostasis, State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, 430072, China
| | - Jiapei Dai
- Wuhan Institute for Neuroscience and Neuroengineering, South-Central University for Nationalities, Wuhan, 430074, China
| | - Yi Liang
- Hubei Key Laboratory of Cell Homeostasis, State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, 430072, China.
| | - Mengchao Cui
- Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing, 100875, China.
| |
Collapse
|
60
|
Kim H, Im YH, Ahn J, Yang J, Choi JY, Lee KH, Kim BT, Choe YS. Synthesis and in vivo characterization of 18F-labeled difluoroboron-curcumin derivative for β-amyloid plaque imaging. Sci Rep 2019; 9:6747. [PMID: 31043696 PMCID: PMC6494845 DOI: 10.1038/s41598-019-43257-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Accepted: 04/17/2019] [Indexed: 11/09/2022] Open
Abstract
Positron emission tomography imaging of β-amyloid (Aβ) plaques has proven useful in the diagnosis of Alzheimer’s disease. A previous study from our group showed that 4′-O-[18F]fluoropropylcurcumin has poor brain permeability, which is thought to be due to its rapid metabolism. In this study, we synthesized difluoroboron complexes of fluorine-substituted curcumin derivatives (1–4) and selected one of them based on the in vitro binding assays. The selected ligand 2 was found to distinctively stain Aβ plaques in APP/PS1 transgenic mouse brain sections. Radioligand [18F]2 was synthesized via a two-step reaction consisting of [18F]fluorination and subsequent aldol condensation. Biodistribution and metabolism studies indicated that radioligand [18F]2 was converted to polar radioactive products and trapped in the normal mouse brain. In contrast, optical images of mice acquired after injection of 2 showed moderate fluorescence signal intensity in the mouse brain at 2 min with a decrease in the signal within 30 min. In the ex vivo optical images, the fluorescence signals in major tissues disappeared within 30 min. Taken together, these results suggest that [18F]2 may be converted to polar 18F-labeled blue-shifted fluorescent products. Further structural modifications are thus needed to render the radioligand metabolically stable.
Collapse
Affiliation(s)
- Hyunjung Kim
- Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul, 06351, Korea
| | - Young Hoon Im
- Department of Nuclear Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, 06351, Korea
| | - Jinhee Ahn
- Department of Nuclear Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, 06351, Korea
| | - Jehoon Yang
- Laboratory Animal Research Center, Samsung Medical Center, Seoul, 06351, Korea
| | - Joon Young Choi
- Department of Nuclear Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, 06351, Korea
| | - Kyung-Han Lee
- Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul, 06351, Korea.,Department of Nuclear Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, 06351, Korea
| | - Byung-Tae Kim
- Department of Nuclear Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, 06351, Korea
| | - Yearn Seong Choe
- Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul, 06351, Korea. .,Department of Nuclear Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, 06351, Korea.
| |
Collapse
|
61
|
Wilson H, Pagano G, Politis M. Dementia spectrum disorders: lessons learnt from decades with PET research. J Neural Transm (Vienna) 2019; 126:233-251. [PMID: 30762136 PMCID: PMC6449308 DOI: 10.1007/s00702-019-01975-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Accepted: 01/21/2019] [Indexed: 02/07/2023]
Abstract
The dementia spectrum encompasses a range of disorders with complex diagnosis, pathophysiology and limited treatment options. Positron emission tomography (PET) imaging provides insights into specific neurodegenerative processes underlying dementia disorders in vivo. Here we focus on some of the most common dementias: Alzheimer’s disease, Parkinsonism dementias including Parkinson’s disease with dementia, dementia with Lewy bodies, progressive supranuclear palsy and corticobasal syndrome, and frontotemporal lobe degeneration. PET tracers have been developed to target specific proteinopathies (amyloid, tau and α-synuclein), glucose metabolism, cholinergic system and neuroinflammation. Studies have shown distinct imaging abnormalities can be detected early, in some cases prior to symptom onset, allowing disease progression to be monitored and providing the potential to predict symptom onset. Furthermore, advances in PET imaging have identified potential therapeutic targets and novel methods to accurately discriminate between different types of dementias in vivo. There are promising imaging markers with a clinical application on the horizon, however, further studies are required before they can be implantation into clinical practice.
Collapse
Affiliation(s)
- Heather Wilson
- Neurodegeneration Imaging Group, Maurice Wohl Clinical Neuroscience Institute, 125 Coldharbour Lane, Camberwell, London, SE5 9NU, UK
| | - Gennaro Pagano
- Neurodegeneration Imaging Group, Maurice Wohl Clinical Neuroscience Institute, 125 Coldharbour Lane, Camberwell, London, SE5 9NU, UK
| | - Marios Politis
- Neurodegeneration Imaging Group, Maurice Wohl Clinical Neuroscience Institute, 125 Coldharbour Lane, Camberwell, London, SE5 9NU, UK.
| |
Collapse
|
62
|
Evaluation of the Feasibility of Screening Tau Radiotracers Using an Amyloid Biomathematical Screening Methodology. COMPUTATIONAL AND MATHEMATICAL METHODS IN MEDICINE 2019; 2018:6287913. [PMID: 30662517 PMCID: PMC6314003 DOI: 10.1155/2018/6287913] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Revised: 11/06/2018] [Accepted: 11/21/2018] [Indexed: 11/17/2022]
Abstract
The purpose of this study is to evaluate the feasibility of extending a previously developed amyloid biomathematical screening methodology to support the screening of tau radiotracers during compound development. 22 tau-related PET radiotracers were investigated. For each radiotracer, in silico MLogP, V x, and in vitro K D were input into the model to predict the in vivo K 1, k 2, and BPND under healthy control (HC), mild cognitive impaired (MCI), and Alzheimer's disease (AD) conditions. These kinetic parameters were used to simulate the time activity curves (TACs) in the target regions of HC, MCI, and AD and a reference region. Standardized uptake value ratios (SUVR) were determined from the integrated area under the TACs of the target region over the reference region within a default time window of 90-110 min. The predicted K 1, k 2, and BPND values were compared with the clinically observed values. The TACs and SUVR distributions were also simulated with population variations and noise. Finally, the clinical usefulness index (CUI) ranking was compared with clinical comparison results. The TACs and SUVR distributions differed for tau radiotracers with lower tau selectivity. The CUI values ranged from 0.0 to 16.2, with 6 out of 9 clinically applied tau radiotracers having CUI values higher than the recommend CUI value of 3.0. The differences between the clinically observed TACs and SUVR results showed that the evaluation of the clinical usefulness of tau radiotracer based on single target binding could not fully reflect in vivo tau binding. The screening methodology requires further study to improve the accuracy of screening tau radiotracers. However, the higher CUI rankings of clinically applied tau radiotracers with higher signal-to-noise ratio supported the use of the screening methodology in radiotracer development by allowing comparison of candidate radiotracers with clinically applied radiotracers based on SUVR, with respect to binding to a single target.
Collapse
|
63
|
Ishikawa A, Tokunaga M, Maeda J, Minamihisamatsu T, Shimojo M, Takuwa H, Ono M, Ni R, Hirano S, Kuwabara S, Ji B, Zhang MR, Aoki I, Suhara T, Higuchi M, Sahara N. In Vivo Visualization of Tau Accumulation, Microglial Activation, and Brain Atrophy in a Mouse Model of Tauopathy rTg4510. J Alzheimers Dis 2019; 61:1037-1052. [PMID: 29332041 DOI: 10.3233/jad-170509] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
BACKGROUND Tau imaging using PET is a promising tool for the diagnosis and evaluation of tau-related neurodegenerative disorders, but the relationship among PET-detectable tau, neuroinflammation, and neurodegeneration is not yet fully understood. OBJECTIVE We aimed to elucidate sequential changes in tau accumulation, neuroinflammation, and brain atrophy by PET and MRI in a tauopathy mouse model. METHODS rTg4510 transgenic (tg) mice expressing P301L mutated tau and non-tg mice were examined with brain MRI and PET imaging (analyzed numbers: tg = 17, non-tg = 13; age 2.5∼14 months). As PET probes, [11C]PBB3 (Pyridinyl-Butadienyl-Benzothiazole 3) and [11C]AC-5216 were used to visualize tau pathology and 18-kDa translocator protein (TSPO) neuroinflammation. Tau pathology and microglia activation were subsequently analyzed by histochemistry. RESULTS PET studies revealed age-dependent increases in [11C]PBB3 and [11C]AC-5216 signals, which were correlated with age-dependent volume reduction in the forebrain on MRI. However, the increase in [11C]PBB3 signals reached a plateau at age 7 months, and therefore its significant correlation with [11C]AC-5216 disappeared after age 7 months. In contrast, [11C]AC-5216 showed a strong correlation with both age and volume reduction until age 14 months. Histochemical analyses confirmed the relevance of pathological tau accumulation and elevated TSPO immunoreactivity in putative microglia. CONCLUSION Our results showed that tau accumulation is associated with neuroinflammation and brain atrophy in a tauopathy mouse model. The time-course of the [11C]PBB3- and TSPO-PET finding suggests that tau deposition triggers progressive neuroinflammation, and the sequential changes can be evaluated in vivo in mouse brains.
Collapse
Affiliation(s)
- Ai Ishikawa
- National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan.,Department of Neurology, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Masaki Tokunaga
- National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
| | - Jun Maeda
- National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
| | | | - Masafumi Shimojo
- National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
| | - Hiroyuki Takuwa
- National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
| | - Maiko Ono
- National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
| | - Ruiqing Ni
- Institute of Biomedical Engineering/Institute for Pharmaceutical Sciences ETH Zurich, Switzerland
| | - Shigeki Hirano
- Department of Neurology, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Satoshi Kuwabara
- Department of Neurology, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Bin Ji
- National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
| | - Ming-Rong Zhang
- National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
| | - Ichio Aoki
- National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
| | - Tetsuya Suhara
- National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
| | - Makoto Higuchi
- National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
| | - Naruhiko Sahara
- National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
| |
Collapse
|
64
|
Duarte Y, Fonseca A, Gutiérrez M, Adasme‐Carreño F, Muñoz‐Gutierrez C, Alzate‐Morales J, Santana L, Uriarte E, Álvarez R, Matos MJ. Novel Coumarin‐Quinoline Hybrids: Design of Multitarget Compounds for Alzheimer's Disease. ChemistrySelect 2019. [DOI: 10.1002/slct.201803222] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
- Yorley Duarte
- Laboratorio de Síntesis Orgánica y Actividad BiológicaInstituto de Química de Recursos NaturalesUniversidad de Talca, Casilla 747 3460000 Talca Chile
- Center for Bioinformatics and Integrative BiologyFacultad de Ciencias de la VidaUniversidad Andrés Bello Santiago 8370146 Chile
| | - André Fonseca
- Departamento de Química OrgánicaFacultad de FarmaciaUniversidade de Santiago de Compostela 15782 Santiago de Compostela España
| | - Margarita Gutiérrez
- Laboratorio de Síntesis Orgánica y Actividad BiológicaInstituto de Química de Recursos NaturalesUniversidad de Talca, Casilla 747 3460000 Talca Chile
| | - Francisco Adasme‐Carreño
- Centro de Bioinformática y Simulación MolecularUniversidad de Talca, Casilla 721 3460000 Talca Chile
| | - Camila Muñoz‐Gutierrez
- Centro de Bioinformática y Simulación MolecularUniversidad de Talca, Casilla 721 3460000 Talca Chile
| | - Jans Alzate‐Morales
- Centro de Bioinformática y Simulación MolecularUniversidad de Talca, Casilla 721 3460000 Talca Chile
| | - Lourdes Santana
- Departamento de Química OrgánicaFacultad de FarmaciaUniversidade de Santiago de Compostela 15782 Santiago de Compostela España
| | - Eugenio Uriarte
- Departamento de Química OrgánicaFacultad de FarmaciaUniversidade de Santiago de Compostela 15782 Santiago de Compostela España
- Instituto de Ciencias Químicas AplicadasUniversidad Autónoma de Chile 7500912 Santiago Chile
| | - Rocío Álvarez
- Laboratory of PharmacologyFaculty of PharmacyUniversidad de Valparaíso Gran Bretaña 1093 2360102 Valparaíso Chile
- Centro de Investigación Farmacopea Chilena (CIFAR), Valparaíso Chile
| | - Maria João Matos
- Departamento de Química OrgánicaFacultad de FarmaciaUniversidade de Santiago de Compostela 15782 Santiago de Compostela España
| |
Collapse
|
65
|
|
66
|
Magro-Checa C, Steup-Beekman GM, Huizinga TW, van Buchem MA, Ronen I. Laboratory and Neuroimaging Biomarkers in Neuropsychiatric Systemic Lupus Erythematosus: Where Do We Stand, Where To Go? Front Med (Lausanne) 2018; 5:340. [PMID: 30564579 PMCID: PMC6288259 DOI: 10.3389/fmed.2018.00340] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Accepted: 11/19/2018] [Indexed: 01/18/2023] Open
Abstract
Systemic lupus erythematosus (SLE) is a chronic autoimmune disease characterized by multi-systemic involvement. Nervous system involvement in SLE leads to a series of uncommon and heterogeneous neuropsychiatric (NP) manifestations. Current knowledge on the underlying pathogenic processes and their subsequent pathophysiological changes leading to NP-SLE manifestations is incomplete. Several putative laboratory biomarkers have been proposed as contributors to the genesis of SLE-related nervous system damage. Alongside the laboratory biomarkers, several neuroimaging tools have shown to reflect the nature of tissue microstructural damage associated with SLE, and thus were suggested to contribute to the understanding of the pathophysiological changes and subsequently help in clinical decision making. However, the number of useful biomarkers in NP-SLE in clinical practice is disconcertingly modest. In some cases it is not clear whether the biomarker is truly involved in pathogenesis, or the result of non-specific pathophysiological changes in the nervous system (e.g., neuroinflammation) or whether it is the consequence of a concomitant underlying abnormality related to SLE activity. In order to improve the diagnosis of NP-SLE and provide a better targeted care to these patients, there is still a need to develop and validate a range of biomarkers that reliably capture the different aspects of disease heterogeneity. This article critically reviews the current state of knowledge on laboratory and neuroimaging biomarkers in NP-SLE, discusses the factors that need to be addressed to make these biomarkers suitable for clinical application, and suggests potential future research paths to address important unmet needs in the NP-SLE field.
Collapse
Affiliation(s)
- César Magro-Checa
- Department of Rheumatology, Leiden University Medical Center, Leiden, Netherlands.,Department of Rheumatology, Zuyderland Medical Center, Heerlen, Netherlands
| | | | - Tom W Huizinga
- Department of Rheumatology, Leiden University Medical Center, Leiden, Netherlands
| | - Mark A van Buchem
- Department of Radiology, Leiden University Medical Center, Leiden, Netherlands.,Department of Radiology, C.J. Gorter Center for High Field MRI, Leiden University Medical Center, Leiden, Netherlands
| | - Itamar Ronen
- Department of Radiology, C.J. Gorter Center for High Field MRI, Leiden University Medical Center, Leiden, Netherlands
| |
Collapse
|
67
|
A Closer Look into the Role of Protein Tau in the Identification of Promising Therapeutic Targets for Alzheimer's Disease. Brain Sci 2018; 8:brainsci8090162. [PMID: 30149687 PMCID: PMC6162660 DOI: 10.3390/brainsci8090162] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2018] [Revised: 08/24/2018] [Accepted: 08/24/2018] [Indexed: 01/09/2023] Open
Abstract
One of the most commonly known chronic neurodegenerative disorders, Alzheimer's disease (AD), manifests the common type of dementia in 60⁻80% of cases. From a clinical standpoint, a patent cognitive decline and a severe change in personality, as caused by a loss of neurons, is usually evident in AD with about 50 million people affected in 2016. The disease progression in patients is distinguished by a gradual plummet in cognitive functions, eliciting symptoms such as memory loss, and eventually requiring full-time medical care. From a histopathological standpoint, the defining characteristics are intracellular aggregations of hyper-phosphorylated tau protein, known as neurofibrillary tangles (NFT), and depositions of amyloid β-peptides (Aβ) in the brain. The abnormal phosphorylation of tau protein is attributed to a wide gamut of neurological disorders known as tauopathies. In addition to the hyperphosphorylated tau lesions, neuroinflammatory processes could occur in a sustained manner through astro-glial activation, resulting in the disease progression. Recent findings have suggested a strong interplay between the mechanism of Tau phosphorylation, disruption of microtubules, and synaptic loss and pathology of AD. The mechanisms underlying these interactions along with their respective consequences in Tau pathology are still ill-defined. Thus, in this review: (1) we highlight the interplays existing between Tau pathology and AD; and (2) take a closer look into its role while identifying some promising therapeutic advances including state of the art imaging techniques.
Collapse
|
68
|
Harada R, Okamura N, Furumoto S, Yanai K. Imaging Protein Misfolding in the Brain Using β-Sheet Ligands. Front Neurosci 2018; 12:585. [PMID: 30186106 PMCID: PMC6110819 DOI: 10.3389/fnins.2018.00585] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Accepted: 08/06/2018] [Indexed: 12/12/2022] Open
Abstract
Neurodegenerative diseases characterized by pathological protein accumulation in cells are termed “proteinopathies.” Although various protein aggregates share cross-β-sheet structures, actual conformations vary among each type of protein deposit. Recent progress in the development of radiotracers for positron emission tomography (PET) has enabled the visualization of protein aggregates in living brains. Amyloid PET tracers have been developed, and are widely used for the diagnosis of Alzheimer’s disease and non-invasive assessment of amyloid burden in clinical trials of anti-dementia drugs. Furthermore, several tau PET tracers have been successfully developed and used in the clinical studies. However, recent studies have identified the presence of off-target binding of radiotracers in areas of tau deposition, suggesting that concomitant neuroinflammatory changes might affect tracer binding. In contrast to amyloid and tau PET, there are no established tracers for imaging Lewy bodies in the human brain. In this review, we describe lessons learned from the development of PET tracers and discuss the future direction of tracer development for protein misfolding diseases.
Collapse
Affiliation(s)
- Ryuichi Harada
- Department of Pharmacology, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Nobuyuki Okamura
- Division of Pharmacology, Tohoku Medical and Pharmaceutical University, Sendai, Japan
| | - Shozo Furumoto
- Cyclotron and Radioisotope Center, Tohoku University, Sendai, Japan
| | - Kazuhiko Yanai
- Department of Pharmacology, Tohoku University Graduate School of Medicine, Sendai, Japan.,Cyclotron and Radioisotope Center, Tohoku University, Sendai, Japan
| |
Collapse
|
69
|
Valotassiou V, Malamitsi J, Papatriantafyllou J, Dardiotis E, Tsougos I, Psimadas D, Alexiou S, Hadjigeorgiou G, Georgoulias P. SPECT and PET imaging in Alzheimer’s disease. Ann Nucl Med 2018; 32:583-593. [PMID: 30128693 DOI: 10.1007/s12149-018-1292-6] [Citation(s) in RCA: 82] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Accepted: 08/14/2018] [Indexed: 12/21/2022]
Affiliation(s)
- Varvara Valotassiou
- Nuclear Medicine Department, University Hospital of Larissa, Mezourlo, 41110, Larissa, Thessaly, Greece.
| | - Julia Malamitsi
- Medical Physics, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | | | | | - Ioannis Tsougos
- Nuclear Medicine Department, University Hospital of Larissa, Mezourlo, 41110, Larissa, Thessaly, Greece
| | - Dimitrios Psimadas
- Nuclear Medicine Department, University Hospital of Larissa, Mezourlo, 41110, Larissa, Thessaly, Greece
| | - Sotiria Alexiou
- Nuclear Medicine Department, University Hospital of Larissa, Mezourlo, 41110, Larissa, Thessaly, Greece
| | - George Hadjigeorgiou
- Neurology Department, University Hospital of Larissa, Thessaly, Greece
- Department of Neurology, Medical School, University of Cyprus, Nicosia, Greece
| | - Panagiotis Georgoulias
- Nuclear Medicine Department, University Hospital of Larissa, Mezourlo, 41110, Larissa, Thessaly, Greece
| |
Collapse
|
70
|
Li C, Takahashi T, Shrestha T, Kinoshita E, Matsubara T, Matsumoto M, Maruyama H. 4',6-Diamidino-2-Phenylindole Distinctly Labels Tau Deposits. J Histochem Cytochem 2018; 66:737-751. [PMID: 30106598 DOI: 10.1369/0022155418793600] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Tau deposits have distinct biochemical characteristics and vary morphologically based on identification with tau antibodies and several chemical dyes. Here, we report 4',6-diamidino-2-phenylindole (DAPI)-positivity of tau deposits. Furthermore, we investigated the cause for this positivity. DAPI was positive in 3R/4R (3-repeat/4-repeat) tau deposits in Alzheimer's disease, myotonic dystrophy, and neurodegeneration with brain iron accumulation, and in 4R tau deposits in corticobasal degeneration, but negative in 4R tau deposits in frontotemporal dementia with parkinsonism-17 and progressive supranuclear palsy. The peak emission wavelength of DAPI after binding to a tau deposit was similar to that after binding to a nucleus. This DAPI-positivity was conspicuous at the optimum concentration of 2 μg/ml. DAPI-positivity was diminished after formic acid treatment, but preserved after nucleic acid elimination and phosphate moiety blocking. Our results suggest that staining with 2 μg/ml DAPI is a common but useful tool to differentially detect tau deposits in various tauopathies.
Collapse
Affiliation(s)
- Chengyu Li
- Department of Clinical Neuroscience and Therapeutics, Graduate School of Biomedical & Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Tetsuya Takahashi
- Department of Clinical Neuroscience and Therapeutics, Graduate School of Biomedical & Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Tejashwi Shrestha
- Department of Clinical Neuroscience and Therapeutics, Graduate School of Biomedical & Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Eiji Kinoshita
- Department of Functional Molecular Science, Graduate School of Biomedical & Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Tomoyasu Matsubara
- Department of Clinical Neuroscience and Therapeutics, Graduate School of Biomedical & Health Sciences, Hiroshima University, Hiroshima, Japan.,Department of Neuropathology, Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan
| | - Masayasu Matsumoto
- Department of Clinical Neuroscience and Therapeutics, Graduate School of Biomedical & Health Sciences, Hiroshima University, Hiroshima, Japan.,Sakai City Medical Center, Sakai, Japan
| | - Hirofumi Maruyama
- Department of Clinical Neuroscience and Therapeutics, Graduate School of Biomedical & Health Sciences, Hiroshima University, Hiroshima, Japan
| |
Collapse
|
71
|
|
72
|
Okamura N, Harada R, Ishiki A, Kikuchi A, Nakamura T, Kudo Y. The development and validation of tau PET tracers: current status and future directions. Clin Transl Imaging 2018; 6:305-316. [PMID: 30148121 PMCID: PMC6096533 DOI: 10.1007/s40336-018-0290-y] [Citation(s) in RCA: 111] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Accepted: 07/03/2018] [Indexed: 01/02/2023]
Abstract
Purpose To provide an overview on positron emission tomography (PET) imaging of tau pathology in Alzheimer’s disease (AD) and other neurodegenerative disorders. Results Different classes of tau tracers such as flortaucipir, THK5317, and PBB3 have been developed and utilized in previous clinical studies. In AD, the topographical distribution of tracer binding follows the known distribution of neurofibrillary tangles and is closely associated with neurodegeneration as well as the clinical phenotype of dementia. Significant retention of tracers has also been observed in the frequent site of the 4-repeat (4R) tau isoform deposits in non-AD tauopathies, such as in progressive supranuclear palsy. However, in vitro binding studies indicate that most tau tracers are less sensitive to straight tau filaments, in contrast to their high binding affinity to paired helical filaments of tau (PHF-tau). The first-generation of tau tracers shows off-target binding in the basal ganglia, midbrain, thalamus, choroid plexus, and venous sinus. Off-target binding of THK5351 to monoamine oxidase B (MAO-B) has been observed in disease-associated brain regions linked to neurodegeneration and is associated with astrogliosis in areas of misfolded protein accumulation. The second generation of tau tracers, such as [18F]MK-6240, is highly selective to PHF-tau with little off-target binding and have enabled the reliable assessment of PHF-tau burden in aging and AD. Conclusions Tau PET tracers have enabled in vivo quantification of PHF-tau burden in human brains. Tau PET can help in understanding the underlying cause of dementia symptoms, and in patient selection for clinical trials of anti-dementia therapies.
Collapse
Affiliation(s)
- Nobuyuki Okamura
- 1Division of Pharmacology, Faculty of Medicine, Tohoku Medical and Pharmaceutical University, Sendai, Japan.,3Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan
| | - Ryuichi Harada
- 2Department of Pharmacology, Tohoku University School of Medicine, Sendai, Japan
| | - Aiko Ishiki
- 3Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan
| | - Akio Kikuchi
- 4Department of Neurology, Tohoku University School of Medicine, Sendai, Japan
| | - Tadaho Nakamura
- 1Division of Pharmacology, Faculty of Medicine, Tohoku Medical and Pharmaceutical University, Sendai, Japan
| | - Yukitsuka Kudo
- 3Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan
| |
Collapse
|
73
|
Murugan NA, Nordberg A, Ågren H. Different Positron Emission Tomography Tau Tracers Bind to Multiple Binding Sites on the Tau Fibril: Insight from Computational Modeling. ACS Chem Neurosci 2018; 9:1757-1767. [PMID: 29630333 DOI: 10.1021/acschemneuro.8b00093] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Using the recently reported cryo-EM structure for the tau fibril [ Fitzpatrick et al. (2017) Nature 547, 185-190 ], which is a potential target concerning Alzheimer's disease, we present the first molecular modeling studies on its interaction with various positron emission tomography (PET) tracers. Experimentally, based on the binding assay studies, at least three different high-affinity binding sites have been reported for tracers in the tau fibril. Herein, through integrated modeling using molecular docking, molecular dynamics, and binding free energy calculations, we provide insight into the binding patterns of various tracers to the tau fibril. We suggest that there are four different high-affinity binding sites available for many of the studied tracers showing varying binding affinity to different binding sites. Thus, PBB3 binds most strongly to site 4, and interestingly, this site is not a preferable site for any other tracers. For THK5351, our data show that it strongly binds to sites 3 and 1, the former one being more preferable. We also find that MK6240 and T807 bind to site 1 specifically. The modeling data also give some insight into whether a tracer bound to a specific site can be replaced by others or not. For example, the displacement of T807 by PBB3 as reported experimentally can also be explained and attributed to the larger binding affinity of the latter compound in all binding sites. The binding free energy results explain very well the small binding affinity of THK523 compared to all the aryl quinoline moieties containing THK tracers. The ability of certain tau tracers, like FDDNP and THK523, to bind to amyloid fibrils has also been investigated. Furthermore, such off-target interaction of tau tracers with amyloid beta fibrils has been validated using a quantum mechanical fragmentation approach.
Collapse
Affiliation(s)
- N. Arul Murugan
- Division of Theoretical Chemistry and Biology, School of Biotechnology, Royal Institute of Technology (KTH), AlbaNova University Center, S-106 91 Stockholm, Sweden
| | - Agneta Nordberg
- Department of Neurobiology, Care Sciences and Society, Center of Alzheimer Research, Division of Clinical Geriatric, Karolinska Institutet, Huddinge, S-141 86 Stockholm, Sweden
- Theme Aging, Karolinska University Hospital, Huddinge, S-141 86 Stockholm, Sweden
| | - Hans Ågren
- Division of Theoretical Chemistry and Biology, School of Biotechnology, Royal Institute of Technology (KTH), AlbaNova University Center, S-106 91 Stockholm, Sweden
- Department of Physics and Astronomy, Uppsala University, SE-751 20 Uppsala, Sweden
| |
Collapse
|
74
|
Molecular imaging in dementia: Past, present, and future. Alzheimers Dement 2018; 14:1522-1552. [DOI: 10.1016/j.jalz.2018.06.2855] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Revised: 06/02/2018] [Accepted: 06/03/2018] [Indexed: 12/14/2022]
|
75
|
Sahara N, Maeda J, Ishikawa A, Tokunaga M, Suhara T, Higuchi M. Microglial Activation During Pathogenesis of Tauopathy in rTg4510 Mice: Implications for the Early Diagnosis of Tauopathy. J Alzheimers Dis 2018; 64:S353-S359. [DOI: 10.3233/jad-179933] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Affiliation(s)
- Naruhiko Sahara
- National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
| | - Jun Maeda
- National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
| | - Ai Ishikawa
- National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
- Department of Neurology, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Masaki Tokunaga
- National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
| | - Tetsuya Suhara
- National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
| | - Makoto Higuchi
- National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
| |
Collapse
|
76
|
Abstract
PURPOSE OF REVIEW To present the new PET markers that could become in the coming years, relevant to advanced clinical approaches to dementia diagnosis, drug trials, and treatment strategies and discuss their advantages and limitations. RECENT FINDINGS The most advanced new PET tracers are the markers of the amyloid plaques, the τ compounds and the tracers of the translocator protein as markers of neuroinflammation. The main advantages but also the weaknesses of each of these markers are discussed. The main pitfall remains the heterogeneity of the available results that cast doubt to a rapid introduction of these new ligands in clinical practice. SUMMARY With the advent of biomarkers in clinical management and findings of molecular neuroimaging studies in the evaluation of patients with suspected dementia, the impact of functional neuroimaging has increased considerably these last years and has been integrated into many clinical guidelines in the field of dementia. In addition to conventional single PET brain perfusion and dopaminergic neurotransmission, 18F-fluorodeoxyglucose (18F-FDG) PET is used in advanced diagnosis procedures. Furthermore, new tracers are being developed to quantify key neuropathological features in the brain tissue as highly specific diagnosis is crucial to comply with the global medical and public health objectives in this domain. A strategic road map for further developments, adapted from the approach to cancer biomarkers, should be proposed so as to optimize the rationale of the PET-based molecular diagnosis of Alzheimer's disease and related disorders.
Collapse
|
77
|
Khan TK. An Algorithm for Preclinical Diagnosis of Alzheimer's Disease. Front Neurosci 2018; 12:275. [PMID: 29760644 PMCID: PMC5936981 DOI: 10.3389/fnins.2018.00275] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Accepted: 04/09/2018] [Indexed: 12/20/2022] Open
Abstract
Almost all Alzheimer's disease (AD) therapeutic trials have failed in recent years. One of the main reasons for failure is due to designing the disease-modifying clinical trials at the advanced stage of the disease when irreversible brain damage has already occurred. Diagnosis of the preclinical stage of AD and therapeutic intervention at this phase, with a perfect target, are key points to slowing the progression of the disease. Various AD biomarkers hold enormous promise for identifying individuals with preclinical AD and predicting the development of AD dementia in the future, but no single AD biomarker has the capability to distinguish the AD preclinical stage. A combination of complimentary AD biomarkers in cerebrospinal fluid (Aβ42, tau, and phosphor-tau), non-invasive neuroimaging, and genetic evidence of AD can detect preclinical AD in the in-vivo ante mortem brain. Neuroimaging studies have examined region-specific cerebral blood flow (CBF) and microstructural changes in the preclinical AD brain. Functional MRI (fMRI), diffusion tensor imaging (DTI) MRI, arterial spin labeling (ASL) MRI, and advanced PET have potential application in preclinical AD diagnosis. A well-validated simple framework for diagnosis of preclinical AD is urgently needed. This article proposes a comprehensive preclinical AD diagnostic algorithm based on neuroimaging, CSF biomarkers, and genetic markers.
Collapse
Affiliation(s)
- Tapan K Khan
- Center for Neurodegenerative Diseases, Blanchette Rockefeller Neurosciences Institute, West Virginia University, Morgantown, WV, United States
| |
Collapse
|
78
|
Abstract
PURPOSE OF REVIEW Tauopathies represent a spectrum of incurable and progressive age-associated neurodegenerative diseases that currently are diagnosed definitively only at autopsy. Few clinical diagnoses, such as classic Richardson's syndrome of progressive supranuclear palsy, are specific for underlying tauopathy and no clinical syndrome is fully sensitive to reliably identify all forms of clinically manifest tauopathy. Thus, a major unmet need for the development and implementation of tau-targeted therapies is precise antemortem diagnosis. This article reviews new and emerging diagnostic therapies for tauopathies including novel imaging techniques and biomarkers and also reviews recent tau therapeutics. RECENT FINDINGS Building evidence from animal and cell models suggests that prion-like misfolding and propagation of pathogenic tau proteins between brain cells are central to the neurodegenerative process. These rapidly growing developments build rationale and motivation for the development of therapeutics targeting this mechanism through altering phosphorylation and other post-translational modifications of the tau protein, blocking aggregation and spread using small molecular compounds or immunotherapy and reducing or silencing expression of the MAPT tau gene. New clinical criteria, CSF, MRI, and PET biomarkers will aid in identifying tauopathies earlier and more accurately which will aid in selection for new clinical trials which focus on a variety of agents including immunotherapy and gene silencing.
Collapse
Affiliation(s)
- David Coughlin
- Frontotemporal Dementia Center (FTDC), University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA.,University of Pennsylvania Perelman School of Medicine, Hospital of the University of Pennsylvania, 3600 Spruce Street, Philadelphia, PA, 19104, USA
| | - David J Irwin
- Frontotemporal Dementia Center (FTDC), University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA.
| |
Collapse
|
79
|
Abstract
PURPOSE Primary progressive aphasia (PPA) is a neurological syndrome in which language functions become progressively impaired with relative sparing of memory and other instrumental functions. The pathologic causes of PPA are heterogeneous, but studies suggest that logopenic PPA (LPA) is underpinned by Alzheimer disease (AD) pathology in a high proportion of cases. The purposes of this descriptive and retrospective study were to characterize F-florbetapir PET imaging in a group of patients with a clinical syndrome of PPA, to determine the value of clinical characterization based on language phenotype in predicting the underlying pathology of PPA with F-florbetapir, and to quantify amyloid load in PPA subjects classified as "positive" F-florbetapir scans. Then, we compare the quantification and distribution of F-florbetapir uptake with those of typical, predominantly amnestic AD patients. METHODS We conducted a PET study with F-florbetapir in a cohort of 12 right-handed patients diagnosed with PPA: 3 patients with semantic-variant PPA, 5 with nonfluent PPA, 1 with LPA, and 3 unclassifiable patients. We evaluated amyloid deposition between APP groups and 11 patients with typical amnestic AD. RESULTS Among the 12 patients with PPA syndrome, 8 (66.7%) were considered as amyloid positive. One of the 3 patients with semantic-variant PPA was F-florbetapir positive. In contrast, 4 of the 5 nonfluent-variant PPA, 2 of the 3 unclassifiable cases and the single patient with LPA were F-florbetapir positive. A significantly higher F-florbetapir uptake was observed in PPA F-florbetapir-positive patients compared with typical AD patients. This difference was observed in all regions of interest, except in posterior cingulate and temporal cortex. CONCLUSIONS These results suggest that F-florbetapir PET may be useful in a routine clinical procedure to improve the reliability of identifying AD pathology in patients with PPA syndrome, with different clinical subtypes of the PPA syndrome.
Collapse
|
80
|
Iqbal K, Liu F, Gong CX. Recent developments with tau-based drug discovery. Expert Opin Drug Discov 2018; 13:399-410. [DOI: 10.1080/17460441.2018.1445084] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Affiliation(s)
- Khalid Iqbal
- Department of Neurochemistry, Inge Grundke-Iqbal Research Floor, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, NY, USA
| | - Fei Liu
- Department of Neurochemistry, Inge Grundke-Iqbal Research Floor, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, NY, USA
| | - Cheng-Xin Gong
- Department of Neurochemistry, Inge Grundke-Iqbal Research Floor, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, NY, USA
| |
Collapse
|
81
|
Lyoo CH, Cho H, Choi JY, Ryu YH, Lee MS. Tau Positron Emission Tomography Imaging in Degenerative Parkinsonisms. J Mov Disord 2018; 11:1-12. [PMID: 29381890 PMCID: PMC5790630 DOI: 10.14802/jmd.17071] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Accepted: 11/20/2017] [Indexed: 01/08/2023] Open
Abstract
In recent years, several radiotracers that selectively bind to pathological tau proteins have been developed. Evidence is emerging that binding patterns of in vivo tau positron emission tomography (PET) studies in Alzheimer’s disease (AD) patients closely resemble the distribution patterns of known neurofibrillary tangle pathology, with the extent of tracer binding reflecting the clinical and pathological progression of AD. In Lewy body diseases (LBD), tau PET imaging has clearly revealed cortical tau burden with a distribution pattern distinct from AD and increased cortical binding within the LBD spectrum. In progressive supranuclear palsy, the globus pallidus and midbrain have shown increased binding most prominently. Tau PET patterns in patients with corticobasal syndrome are characterized by asymmetrical uptake in the motor cortex and underlying white matter, as well as in the basal ganglia. Even in the patients with multiple system atrophy, which is basically a synucleinopathy, 18F-flortaucipir, a widely used tau PET tracer, also binds to the atrophic posterior putamen, possibly due to off-target binding. These distinct patterns of tau-selective radiotracer binding in the various degenerative parkinsonisms suggest its utility as a potential imaging biomarker for the differential diagnosis of parkinsonisms.
Collapse
Affiliation(s)
- Chul Hyoung Lyoo
- Department of Neurology, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
| | - Hanna Cho
- Department of Neurology, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
| | - Jae Yong Choi
- Department of Nuclear Medicine, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.,Division of RI-Convergence Research, Korea Institute Radiological and Medical Sciences, Seoul, Korea
| | - Young Hoon Ryu
- Department of Nuclear Medicine, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
| | - Myung Sik Lee
- Department of Neurology, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
| |
Collapse
|
82
|
Wu XL, Piña-Crespo J, Zhang YW, Chen XC, Xu HX. Tau-mediated Neurodegeneration and Potential Implications in Diagnosis and Treatment of Alzheimer's Disease. Chin Med J (Engl) 2017; 130:2978-2990. [PMID: 29237931 PMCID: PMC5742926 DOI: 10.4103/0366-6999.220313] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2017] [Indexed: 11/18/2022] Open
Abstract
OBJECTIVE To review recent research advances on tau, a major player in Alzheimer's disease (AD) pathogenesis, a biomarker for AD onset, and potential target for AD therapy. DATA SOURCES This review was based on a comprehensive search using online literature databases, including PubMed, Web of Science, and Google Scholar. STUDY SELECTION Literature search was based on the following keywords: Alzheimer's disease, tau protein, biomarker, cerebrospinal fluid (CSF), therapeutics, plasma, imaging, propagation, spreading, seeding, prion, conformational templating, and posttranslational modification. Relevant articles were carefully reviewed, with no exclusions applied to study design and publication type. RESULTS Amyloid plaques enriched with extracellular amyloid beta (Aβ) and intracellular neurofibrillary tangles comprised of hyperphosphorylated tau proteins are the two main pathological hallmarks of AD. Although the Aβ hypothesis has dominated AD research for many years, clinical Aβ-targeting strategies have consistently failed to effectively treat AD or prevent AD onset. The research focus in AD has recently shifted to the role of tau in AD. In addition to phosphorylation, tau is acetylated and proteolytically cleaved, which also contribute to its physiological and pathological functions. Emerging evidence characterizing pathological tau propagation and spreading provides new avenues for research into the molecular and cellular mechanisms underlying AD pathogenesis. Techniques to detect tau at minute levels in CSF and blood have been developed, and improved tracers have facilitated tau imaging in the brain. These advances have potential to accurately determine tau levels at early diagnostic stages in AD. Given that tau is a potential therapeutic target, anti-tau immunotherapy may potentially be a viable treatment strategy in AD intervention. CONCLUSION Detecting changes in tau and targeting tau pathology represent a promising lead in the diagnosis and treatment of AD.
Collapse
Affiliation(s)
- Xi-Lin Wu
- Neuroscience Initiative, Neuroscience and Aging Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
- Department of Neurology, Fujian Institute of Geriatrics, Fujian Medical University Union Hospital, Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou, Fujian 350001, China
| | - Juan Piña-Crespo
- Neuroscience Initiative, Neuroscience and Aging Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
| | - Yun-Wu Zhang
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, College of Medicine, Xiamen University, Xiamen, Fujian 361102, China
| | - Xiao-Chun Chen
- Department of Neurology, Fujian Institute of Geriatrics, Fujian Medical University Union Hospital, Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou, Fujian 350001, China
| | - Hua-Xi Xu
- Neuroscience Initiative, Neuroscience and Aging Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, College of Medicine, Xiamen University, Xiamen, Fujian 361102, China
| |
Collapse
|
83
|
Sahara N, Shimojo M, Ono M, Takuwa H, Febo M, Higuchi M, Suhara T. In Vivo Tau Imaging for a Diagnostic Platform of Tauopathy Using the rTg4510 Mouse Line. Front Neurol 2017; 8:663. [PMID: 29375461 PMCID: PMC5770623 DOI: 10.3389/fneur.2017.00663] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Accepted: 11/23/2017] [Indexed: 12/23/2022] Open
Abstract
Association of tau deposition with neurodegeneration in Alzheimer's disease (AD) and related tau-positive neurological disorders collectively referred to as tauopathies indicates contribution of tau aggregates to neurotoxicity. The discovery of tau gene mutations in FTDP-17-tau kindreds has provided unequivocal evidence that tau abnormalities alone can induce neurodegenerative disorders. Therefore, visualization of tau accumulation would offer a reliable, objective index to aid in the diagnosis of tauopathy and to assess the disease progression. Positron emission tomography (PET) imaging of tau lesions is currently available using several tau PET ligands. Because most tau PET ligands have the property of an extrinsic fluorescent dye, these ligands are considered to be useful for both PET and fluorescence imaging. In addition, small-animal magnetic resonance imaging (MRI) is available for both structural and functional imaging. Using these advanced imaging techniques, in vivo studies on a mouse model of tauopathy will provide significant insight into the translational research of neurodegenerative diseases. In this review, we will discuss the utilities of PET, MRI, and fluorescence imaging for evaluating the disease progression of tauopathy.
Collapse
Affiliation(s)
- Naruhiko Sahara
- Department of Functional Brain Imaging Research, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
| | - Masafumi Shimojo
- Department of Functional Brain Imaging Research, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
| | - Maiko Ono
- Department of Functional Brain Imaging Research, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
| | - Hiroyuki Takuwa
- Department of Functional Brain Imaging Research, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
| | - Marcelo Febo
- Department of Psychiatry and Neuroscience, University of Florida College of Medicine, Gainesville, FL, United States
| | - Makoto Higuchi
- Department of Functional Brain Imaging Research, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
| | - Tetsuya Suhara
- Department of Functional Brain Imaging Research, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
| |
Collapse
|
84
|
Brier MR, Gordon B, Friedrichsen K, McCarthy J, Stern A, Christensen J, Owen C, Aldea P, Su Y, Hassenstab J, Cairns NJ, Holtzman DM, Fagan AM, Morris JC, Benzinger TLS, Ances BM. Tau and Aβ imaging, CSF measures, and cognition in Alzheimer's disease. Sci Transl Med 2017; 8:338ra66. [PMID: 27169802 PMCID: PMC5267531 DOI: 10.1126/scitranslmed.aaf2362] [Citation(s) in RCA: 504] [Impact Index Per Article: 72.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Accepted: 04/22/2016] [Indexed: 12/12/2022]
Abstract
Alzheimer's disease (AD) is characterized by two molecular pathologies: cerebral β-amyloidosis in the form of β-amyloid (Aβ) plaques and tauopathy in the form of neurofibrillary tangles, neuritic plaques, and neuropil threads. Until recently, only Aβ could be studied in humans using positron emission tomography (PET) imaging owing to a lack of tau PET imaging agents. Clinical pathological studies have linked tau pathology closely to the onset and progression of cognitive symptoms in patients with AD. We report PET imaging of tau and Aβ in a cohort of cognitively normal older adults and those with mild AD. Multivariate analyses identified unique disease-related stereotypical spatial patterns (topographies) for deposition of tau and Aβ. These PET imaging tau and Aβ topographies were spatially distinct but correlated with disease progression. Cerebrospinal fluid measures of tau, often used to stage preclinical AD, correlated with tau deposition in the temporal lobe. Tau deposition in the temporal lobe more closely tracked dementia status and was a better predictor of cognitive performance than Aβ deposition in any region of the brain. These data support models of AD where tau pathology closely tracks changes in brain function that are responsible for the onset of early symptoms in AD.
Collapse
Affiliation(s)
- Matthew R Brier
- Department of Neurology, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Brian Gordon
- Department of Radiology, Washington University in St. Louis, St. Louis, MO 63110, USA. Knight Alzheimer's Disease Research Center, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Karl Friedrichsen
- Department of Radiology, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - John McCarthy
- Department of Mathematics, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Ari Stern
- Department of Mathematics, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Jon Christensen
- Department of Radiology, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Christopher Owen
- Department of Radiology, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Patricia Aldea
- Department of Radiology, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Yi Su
- Department of Radiology, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Jason Hassenstab
- Department of Neurology, Washington University in St. Louis, St. Louis, MO 63110, USA. Knight Alzheimer's Disease Research Center, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Nigel J Cairns
- Department of Neurology, Washington University in St. Louis, St. Louis, MO 63110, USA. Knight Alzheimer's Disease Research Center, Washington University in St. Louis, St. Louis, MO 63110, USA. Department of Pathology, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - David M Holtzman
- Department of Neurology, Washington University in St. Louis, St. Louis, MO 63110, USA. Knight Alzheimer's Disease Research Center, Washington University in St. Louis, St. Louis, MO 63110, USA. Hope Center for Neurological Disorders, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Anne M Fagan
- Department of Neurology, Washington University in St. Louis, St. Louis, MO 63110, USA. Knight Alzheimer's Disease Research Center, Washington University in St. Louis, St. Louis, MO 63110, USA. Hope Center for Neurological Disorders, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - John C Morris
- Department of Neurology, Washington University in St. Louis, St. Louis, MO 63110, USA. Knight Alzheimer's Disease Research Center, Washington University in St. Louis, St. Louis, MO 63110, USA. Department of Pathology, Washington University in St. Louis, St. Louis, MO 63110, USA. Hope Center for Neurological Disorders, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Tammie L S Benzinger
- Department of Radiology, Washington University in St. Louis, St. Louis, MO 63110, USA. Knight Alzheimer's Disease Research Center, Washington University in St. Louis, St. Louis, MO 63110, USA. Department of Neurosurgery, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Beau M Ances
- Department of Neurology, Washington University in St. Louis, St. Louis, MO 63110, USA. Department of Radiology, Washington University in St. Louis, St. Louis, MO 63110, USA. Knight Alzheimer's Disease Research Center, Washington University in St. Louis, St. Louis, MO 63110, USA. Hope Center for Neurological Disorders, Washington University in St. Louis, St. Louis, MO 63110, USA.
| |
Collapse
|
85
|
Shirani H, Appelqvist H, Bäck M, Klingstedt T, Cairns NJ, Nilsson KPR. Synthesis of Thiophene-Based Optical Ligands That Selectively Detect Tau Pathology in Alzheimer's Disease. Chemistry 2017; 23:17127-17135. [PMID: 28926133 PMCID: PMC5928317 DOI: 10.1002/chem.201703846] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Indexed: 01/09/2023]
Abstract
The accumulation of protein aggregates is associated with many devastating neurodegenerative diseases and the development of molecular ligands able to detect these pathological hallmarks is essential. Here, the synthesis of thiophene based optical ligands, denoted bi-thiophene-vinyl-benzothiazoles (bTVBTs) that can be utilized for selective assignment of tau aggregates in brain tissue with Alzheimer's disease (AD) pathology is reported. The ability of the ligands to selectively distinguish tau deposits from the other AD associated pathological hallmark, senile plaques consisting of aggregated amyloid-β (Aβ) peptide, was reduced when the chemical composition of the ligands was altered, verifying that specific molecular interactions between the ligands and the aggregates are necessary for the selective detection of tau deposits. Our findings provide the structural and functional basis for the development of new fluorescent ligands that can distinguish between aggregated proteinaceous species consisting of different proteins. In addition, the bTVBT scaffold might be utilized to create powerful practical research tools for studying the underlying molecular events of tau aggregation and for creating novel agents for clinical imaging of tau pathology in AD.
Collapse
Affiliation(s)
- Hamid Shirani
- Division of Chemistry, Department of Physics, Chemistry and Biology, Linköping University, SE-581 83 Linköping, Sweden
| | - Hanna Appelqvist
- Division of Chemistry, Department of Physics, Chemistry and Biology, Linköping University, SE-581 83 Linköping, Sweden
| | - Marcus Bäck
- Division of Chemistry, Department of Physics, Chemistry and Biology, Linköping University, SE-581 83 Linköping, Sweden
| | - Therése Klingstedt
- Division of Chemistry, Department of Physics, Chemistry and Biology, Linköping University, SE-581 83 Linköping, Sweden
| | - Nigel J. Cairns
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri, U.S.A
| | - K. Peter R. Nilsson
- Division of Chemistry, Department of Physics, Chemistry and Biology, Linköping University, SE-581 83 Linköping, Sweden
| |
Collapse
|
86
|
Boudjelal A, Messali Z, Elmoataz A, Attallah B. Improved Simultaneous Algebraic Reconstruction Technique Algorithm for Positron-Emission Tomography Image Reconstruction via Minimizing the Fast Total Variation. J Med Imaging Radiat Sci 2017; 48:385-393. [PMID: 31047474 DOI: 10.1016/j.jmir.2017.09.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Revised: 09/05/2017] [Accepted: 09/15/2017] [Indexed: 12/15/2022]
Abstract
CONTEXT There has been considerable progress in the instrumentation for data measurement and computer methods for generating images of measured PET data. These computer methods have been developed to solve the inverse problem, also known as the "image reconstruction from projections" problem. AIM In this paper, we propose a modified Simultaneous Algebraic Reconstruction Technique (SART) algorithm to improve the quality of image reconstruction by incorporating total variation (TV) minimization into the iterative SART algorithm. METHODOLOGY The SART updates the estimated image by forward projecting the initial image onto the sinogram space. Then, the difference between the estimated sinogram and the given sinogram is back-projected onto the image domain. This difference is then subtracted from the initial image to obtain a corrected image. Fast total variation (FTV) minimization is applied to the image obtained in the SART step. The second step is the result obtained from the previous FTV update. The SART and the FTV minimization steps run iteratively in an alternating manner. Fifty iterations were applied to the SART algorithm used in each of the regularization-based methods. In addition to the conventional SART algorithm, spatial smoothing was used to enhance the quality of the image. All images were sized at 128 × 128 pixels. RESULTS The proposed algorithm successfully accomplished edge preservation. A detailed scrutiny revealed that the reconstruction algorithms differed; for example, the SART and the proposed FTV-SART algorithm effectively preserved the hot lesion edges, whereas artifacts and deviations were more likely to occur in the ART algorithm than in the other algorithms. CONCLUSIONS Compared to the standard SART, the proposed algorithm is more robust in removing background noise while preserving edges to suppress the existent image artifacts. The quality measurements and visual inspections show a significant improvement in image quality compared to the conventional SART and Algebraic Reconstruction Technique (ART) algorithms.
Collapse
Affiliation(s)
- Abdelwahhab Boudjelal
- Electronics Department, University of Mohammed Boudiaf-M'sila, M'sila, Algeria; Image Team, GREYC Laboratory, University of Caen Normandy, Caen Cedex, France.
| | - Zoubeida Messali
- Electronics Department, University of Mohamed El Bachir El Ibrahimi-Bordj Bou Arréridj, Bordj Bou Arréridj, Algeria
| | - Abderrahim Elmoataz
- Image Team, GREYC Laboratory, University of Caen Normandy, Caen Cedex, France
| | - Bilal Attallah
- Electronics Department, University of Mohammed Boudiaf-M'sila, M'sila, Algeria; Image Team, GREYC Laboratory, University of Caen Normandy, Caen Cedex, France
| |
Collapse
|
87
|
Okamura N, Harada R, Furumoto S, Nakamura T, Yanai K, Kudo Y. Development of molecular imaging probe targeted at Alzheimer's disease pathology. Nihon Yakurigaku Zasshi 2017; 150:172-176. [PMID: 28966214 DOI: 10.1254/fpj.150.172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
88
|
Alves GS, de Carvalho LDA, Sudo FK, Briand L, Laks J, Engelhardt E. A panel of clinical and neuropathological features of cerebrovascular disease through the novel neuroimaging methods. Dement Neuropsychol 2017; 11:343-355. [PMID: 29354214 PMCID: PMC5769992 DOI: 10.1590/1980-57642016dn11-040003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
UNLABELLED The last decade has witnessed substantial progress in acquiring diagnostic biomarkers for the diagnostic workup of cerebrovascular disease (CVD). Advanced neuroimaging methods not only provide a strategic contribution for the differential diagnosis of vascular dementia (VaD) and vascular cognitive impairment (VCI), but also help elucidate the pathophysiological mechanisms ultimately leading to small vessel disease (SVD) throughout its course. OBJECTIVE In this review, the novel imaging methods, both structural and metabolic, were summarized and their impact on the diagnostic workup of age-related CVD was analysed. Methods: An electronic search between January 2010 and 2017 was carried out on PubMed/MEDLINE, Institute for Scientific Information Web of Knowledge and EMBASE. RESULTS The use of full functional multimodality in simultaneous Magnetic Resonance (MR)/Positron emission tomography (PET) may potentially improve the clinical characterization of VCI-VaD; for structural imaging, MRI at 3.0 T enables higher-resolution scanning with greater imaging matrices, thinner slices and more detail on the anatomical structure of vascular lesions. CONCLUSION Although the importance of most of these techniques in the clinical setting has yet to be recognized, there is great expectancy in achieving earlier and more refined therapeutic interventions for the effective management of VCI-VaD.
Collapse
Affiliation(s)
| | | | - Felipe Kenji Sudo
- Departamento de Psicologia, Pontifícia Universidade Católica do Rio de Janeiro, RJ, Brazil
- Instituto D'Or de Ensino e Pesquisa, Rio de Janeiro, RJ, Brazil
| | - Lucas Briand
- Departamento de Medicina Interna, Universidade Federal do Ceará, CE, Brazil
| | - Jerson Laks
- Instituto de Psiquiatria, Universidade Federal do Rio de Janeiro, RJ, Brazil
- Programa de Pós-Graduação em Biomedicina Translacional (BIOTRANS), Unigranrio, Duque de Caxias, RJ, Brazil
| | - Eliasz Engelhardt
- Setor de Neurologia Cognitiva e do Comportamento, Instituto de Neurologia Deolindo Couto (INDC-CDA/IPUB), Rio de Janeiro, RJ, Brazil
| |
Collapse
|
89
|
Villemagne VL. Selective Tau Imaging: Der Stand der Dinge. J Nucl Med 2017; 59:175-176. [PMID: 28935837 DOI: 10.2967/jnumed.117.198325] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Accepted: 09/13/2017] [Indexed: 11/16/2022] Open
Affiliation(s)
- Victor L Villemagne
- Department of Molecular Imaging and Therapy, Austin Health, Melbourne, Australia; Department of Medicine, Austin Health, University of Melbourne, Melbourne, Australia; and Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, Australia
| |
Collapse
|
90
|
Tau plasma levels in subjective cognitive decline: Results from the DELCODE study. Sci Rep 2017; 7:9529. [PMID: 28842559 PMCID: PMC5573353 DOI: 10.1038/s41598-017-08779-0] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Accepted: 07/18/2017] [Indexed: 12/23/2022] Open
Abstract
Previous studies have demonstrated increased tau plasma levels in patients with Alzheimer’s disease (AD) and mild cognitive impairment (MCI) due to AD. Much less is known whether increased tau plasma levels can already be detected in the pre-MCI stage of subjective cognitive decline (SCD). In the present study we measured tau plasma levels in 111 SCD patients and 134 age- and gender-matched cognitively healthy controls participating in the DZNE (German Center for Neurodegenerative Diseases) longitudinal study on cognition and dementia (DELCODE). Tau plasma levels were measured using ultra-sensitive, single-molecule array (Simoa) technology. We found no significant different tau plasma levels in SCD (3.4 pg/ml) compared with healthy controls (3.6 pg/ml) after controlling for age, gender, and education (p = 0.137). In addition, tau plasma levels did not correlate with Aβ42 (r = 0.073; p = 0.634), tau (r = −0.179; p = 0.240), and p-tau181 (r = −0.208; p = 0.171) cerebrospinal fluid (CSF) levels in a subgroup of 45 SCD patients with available CSF. In conclusion, plasma tau is not increased in SCD patients. In addition, the lack of correlation between tau in plasma and CSF in the examined cohort suggests that tau levels are affected by different factors in both biofluids.
Collapse
|
91
|
Abstract
Frontotemporal dementia (FTD) is the second most common cause of dementia following Alzheimer's disease (AD). Between 20 and 50% of cases are familial. Mutations in MAPT, GRN and C9orf72 are found in 60% of familial FTD cases. C9orf72 mutations are the most common and account for 25%. Rarer mutations (<5%) occur in other genes such as VPC, CHMP2B, TARDP, FUS, ITM2B, TBK1 and TBP. The diagnosis is often challenging due to symptom overlap with AD and other conditions. We review the genetics, clinical presentations, neuroimaging, neuropathology, animal studies and therapeutic trials in FTD. We describe clinical scenarios including the original family with the tau stem loop mutation (+14) and also the recently discovered 'missing tau' mutation +15 that 'closed the loop' in 2015.
Collapse
|
92
|
Bischof GN, Endepols H, van Eimeren T, Drzezga A. Tau-imaging in neurodegeneration. Methods 2017; 130:114-123. [PMID: 28790016 DOI: 10.1016/j.ymeth.2017.08.003] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2017] [Revised: 07/25/2017] [Accepted: 08/04/2017] [Indexed: 10/19/2022] Open
Abstract
Pathological cerebral aggregations of proteins are suggested to play a crucial role in the development of neurodegenerative disorders. For example, aggregation of the protein ß-amyloid in form of extracellular amyloid-plaques as well as intraneuronal depositions of the protein tau in form of neurofibrillary tangles represent hallmarks of Alzheimer's disease (AD). Recently, novel tracers for in vivo molecular imaging of tau-aggregates in the brain have been introduced, complementing existing tracers for imaging amyloid-plaques. Available data on these novel tracers indicate that the subject of Tau-PET may be of considerable complexity. On the one hand this refers to the various forms of appearance of tau-pathology in different types of neurodegenerative disorders. On the other hand, a number of hurdles regarding validation of these tracers still need to be overcome with regard to comparability and standardization of the different tracers, observed off-target/non-specific binding and quantitative interpretation of the signal. These issues will have to be clarified before systematic clinical application of this exciting new methodological approach may become possible. Potential applications refer to early detection of neurodegeneration, differential diagnosis between tauopathies and non-tauopathies and specific patient selection and follow-up in therapy trials.
Collapse
Affiliation(s)
| | - Heike Endepols
- Department of Nuclear Medicine, University of Cologne, Germany
| | - Thilo van Eimeren
- Department of Nuclear Medicine, University of Cologne, Germany; German Research Center for Neurodegenerative Diseases (DZNE), Germany
| | - Alexander Drzezga
- Department of Nuclear Medicine, University of Cologne, Germany; German Research Center for Neurodegenerative Diseases (DZNE), Germany.
| |
Collapse
|
93
|
Abstract
Newly developed tissue clearing techniques can be used to render intact tissues transparent. When combined with fluorescent labeling technologies and optical sectioning microscopy, this allows visualization of fine structure in three dimensions. Gene-transfection techniques have proved very useful in visualizing cellular structures in animal models, but they are not applicable to human brain tissue. Here, we discuss the characteristics of an ideal chemical fluorescent probe for use in brain and other cleared tissues, and offer a comprehensive overview of currently available chemical probes. We describe their working principles and compare their performance with the goal of simplifying probe selection for neuropathologists and stimulating probe development by chemists. We propose several approaches for the development of innovative chemical labeling methods which, when combined with tissue clearing, have the potential to revolutionize how we study the structure and function of the human brain.
Collapse
Affiliation(s)
- Hei Ming Lai
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR, China; Neuropathology Unit, Division of Brain Sciences, Department of Medicine, Imperial College London, London W12 0NN, UK.
| | - Wai-Lung Ng
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3TA, UK
| | - Steve M Gentleman
- Neuropathology Unit, Division of Brain Sciences, Department of Medicine, Imperial College London, London W12 0NN, UK.
| | - Wutian Wu
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR, China; State Key Laboratory of Brain and Cognitive Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR, China; Research Center of Reproduction, Development and Growth, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR, China; Joint Laboratory of Jinan University and The University of Hong Kong, GHM Institute of CNS Regeneration, Jinan University, Guangzhou 510632, China.
| |
Collapse
|
94
|
Mathis CA, Lopresti BJ, Ikonomovic MD, Klunk WE. Small-molecule PET Tracers for Imaging Proteinopathies. Semin Nucl Med 2017; 47:553-575. [PMID: 28826526 DOI: 10.1053/j.semnuclmed.2017.06.003] [Citation(s) in RCA: 77] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
In this chapter, we provide a review of the challenges and advances in developing successful PET imaging agents for 3 major types of aggregated amyloid proteins: amyloid-beta (Aβ), tau, and alpha-synuclein (α-syn). These 3 amyloids are involved in the pathogenesis of a variety of neurodegenerative diseases, referred to as proteinopathies or proteopathies, that include Alzheimer disease, Lewy body dementias, multiple system atrophy, and frontotemporal dementias, among others. In the Introduction section, we briefly discuss the history of amyloid in neurodegenerative diseases and describe why progress in developing effective imaging agents has been hampered by the failure of crystallography to provide definitive ligand-protein interactions for rational radioligand design efforts. Instead, the field has relied on largely serendipitous, trial-and-error methods to achieve useful and specific PET amyloid imaging tracers for Aβ, tau, and α-syn deposits. Because many of the proteopathies involve more than 1 amyloid protein, it is important to develop selective PET tracers for the different amyloids to help assess the relative contribution of each to total amyloid burden. We use Pittsburgh compound B to illustrate some of the critical steps in developing a potent and selective Aβ PET imaging agent. Other selective Aβ and tau PET imaging compounds have followed similar pathways in their developmental processes. Success for selective α-syn PET imaging agents has not been realized yet, but work is ongoing in multiple laboratories throughout the world. In the tau sections, we provide background regarding 3-repeat (3R) and 4-repeat (4R) tau proteins and how they can affect the binding of tau radioligands in different tauopathies. We review the ongoing efforts to assess the properties of tau ligands, which are useful in 3R, 4R, or combined 3R-4R tauopathies. Finally, we describe in the α-syn sections recent attempts to develop selective tracers to image α-synucleinopathies.
Collapse
Affiliation(s)
- Chester A Mathis
- Department of Radiology, University of Pittsburgh School of Medicine, Pittsburgh, PA.
| | - Brian J Lopresti
- Department of Radiology, University of Pittsburgh School of Medicine, Pittsburgh, PA
| | - Milos D Ikonomovic
- Department of Neurology, University of Pittsburgh School of Medicine, Pittsburgh, PA
| | - William E Klunk
- Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, PA
| |
Collapse
|
95
|
Vāvere AL, Scott PJH. Clinical Applications of Small-molecule PET Radiotracers: Current Progress and Future Outlook. Semin Nucl Med 2017; 47:429-453. [PMID: 28826519 DOI: 10.1053/j.semnuclmed.2017.05.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Radiotracers, or radiopharmaceuticals, are bioactive molecules tagged with a radionuclide used for diagnostic imaging or radiotherapy and, when a positron-emitting radionuclide is chosen, the radiotracers are used for PET imaging. The development of novel PET radiotracers in many ways parallels the development of new pharmaceuticals, and small molecules dominate research and development pipelines in both disciplines. The 4 decades since the introduction of [18F]FDG have seen the development of many small molecule PET radiotracers. Ten have been approved by the US Food and Drug Administration as of 2016, whereas hundreds more are being evaluated clinically. These radiotracers are being used in personalized medicine and to support drug discovery programs where they are greatly improving our understanding of and ability to treat diseases across many areas of medicine including neuroscience, cardiovascular medicine, and oncology.
Collapse
Affiliation(s)
- Amy L Vāvere
- Department of Diagnostic Imaging, St. Jude Children's Research Hospital, Memphis, TN
| | - Peter J H Scott
- Department of Radiology, University of Michigan, Ann Arbor, MI.
| |
Collapse
|
96
|
Rauch JN, Olson SH, Gestwicki JE. Interactions between Microtubule-Associated Protein Tau (MAPT) and Small Molecules. Cold Spring Harb Perspect Med 2017; 7:cshperspect.a024034. [PMID: 27940599 DOI: 10.1101/cshperspect.a024034] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Tau aggregation is linked to multiple neurodegenerative disorders that are collectively termed tauopathies. Small molecules are powerful probes of the aggregation process, helping to reveal the key steps and serving as diagnostics and reporters. Moreover, some of these small molecules may have potential as therapeutics. This review details how small molecules and chemical biology have helped to elucidate the mechanisms of tau aggregation and how they are being used to detect and prevent tau aggregation. In addition, we comment on how new insights into tau prions are changing the approach to small molecule discovery.
Collapse
Affiliation(s)
- Jennifer N Rauch
- Institute for Neurodegenerative Diseases, Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, California 94158
| | - Steven H Olson
- Institute for Neurodegenerative Diseases, Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, California 94158
| | - Jason E Gestwicki
- Institute for Neurodegenerative Diseases, Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, California 94158
| |
Collapse
|
97
|
Hall B, Mak E, Cervenka S, Aigbirhio FI, Rowe JB, O’Brien JT. In vivo tau PET imaging in dementia: Pathophysiology, radiotracer quantification, and a systematic review of clinical findings. Ageing Res Rev 2017; 36:50-63. [PMID: 28315409 DOI: 10.1016/j.arr.2017.03.002] [Citation(s) in RCA: 85] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Revised: 02/15/2017] [Accepted: 03/06/2017] [Indexed: 12/14/2022]
Abstract
In addition to the deposition of β-amyloid plaques, neurofibrillary tangles composed of aggregated hyperphosphorylated tau are one of the pathological hallmarks of Alzheimer's disease and other neurodegenerative disorders. Until now, our understanding about the natural history and topography of tau deposition has only been based on post-mortem and cerebrospinal fluid studies, and evidence continues to implicate tau as a central driver of downstream neurodegenerative processes and cognitive decline. Recently, it has become possible to assess the regional distribution and severity of tau burden in vivo with the development of novel radiotracers for positron emission tomography (PET) imaging. In this article, we provide a comprehensive discussion of tau pathophysiology, its quantification with novel PET radiotracers, as well as a systematic review of tau PET imaging in normal aging and various dementia conditions: mild cognitive impairment, Alzheimer's disease, frontotemporal dementia, progressive supranuclear palsy, and Lewy body dementia. We discuss the main findings in relation to group differences, clinical-cognitive correlations of tau PET, and multi-modal relationships among tau PET and other pathological markers. Collectively, the small but growing literature of tau PET has yielded consistent anatomical patterns of tau accumulation that recapitulate post-mortem distribution of neurofibrillary tangles which correlate with cognitive functions and other markers of pathology. In general, AD is characterised by increased tracer retention in the inferior temporal lobe, extending into the frontal and parietal regions in more severe cases. It is also noted that the spatial topography of tau accumulation is markedly distinct to that of amyloid burden in aging and AD. Tau PET imaging has also revealed characteristic spatial patterns among various non-AD tauopathies, supporting its potential role for differential diagnosis. Finally, we propose novel directions for future tau research, including (a) longitudinal imaging in preclinical dementia, (b) multi-modal mapping of tau pathology onto other pathological processes such as neuroinflammation, and (c) the need for more validation studies against post-mortem samples of the same subjects.
Collapse
|
98
|
Coakeley S, Strafella AP. Imaging tau pathology in Parkinsonisms. NPJ Parkinsons Dis 2017; 3:22. [PMID: 28685158 PMCID: PMC5491530 DOI: 10.1038/s41531-017-0023-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Revised: 06/01/2017] [Accepted: 06/02/2017] [Indexed: 12/23/2022] Open
Abstract
The recent development of positron emission tomography radiotracers targeting pathological tau in vivo has led to numerous human trials. While investigations have primarily focused on the most common tauopathy, Alzheimer's disease, it is imperative that testing also be performed in parkinsonian tauopathies, such as progressive supranuclear palsy, corticobasal degeneration, and frontotemporal dementia and parkinsonism linked to chromosome 17. Tau aggregates differ in isoforms and conformations across disorders, and as a result one radiotracer may not be appropriate for all tauopathies. In this review, we evaluate the preclinical and clinical reports of current tau radiotracers in parkinsonian disorders. These radiotracers include [18F]FDDNP, [11C]PBB3, [18F]THK-5317, [18F]THK-5351, and [18F]AV-1451 ([18F]T807). There are concerns of off-target binding with [18F]FDDNP and [11C]PBB3, which may increase the signal to noise ratio and thereby decrease the efficacy of these radiotracers. Testing in [18F]THK-5317, [18F]THK-5351, and [18F]AV-1451 has been performed in progressive supranuclear palsy, while [18F]THK-5317 and [18F]AV-1451 have also been tested in corticobasal degeneration patients. [18F]THK-5317 and [18F]THK-5351 have demonstrated binding in brain regions known to be afflicted with pathological tau; however, due to small sample sizes these studies should be replicated before concluding their appropriateness in parkinsonian tauopathies. [18F]AV-1451 has demonstrated mixed results in progressive supranuclear palsy patients and post-mortem analysis shows minimal to no binding to non-Alzheimer's disease tauopathies brain slices.
Collapse
Affiliation(s)
- Sarah Coakeley
- Research Imaging Centre, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, University of Toronto, Toronto, ON Canada
- Division of Brain, Imaging and Behaviour—Systems Neuroscience, Krembil Research Institute, UHN, University of Toronto, Toronto, ON Canada
| | - Antonio P. Strafella
- Research Imaging Centre, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, University of Toronto, Toronto, ON Canada
- Division of Brain, Imaging and Behaviour—Systems Neuroscience, Krembil Research Institute, UHN, University of Toronto, Toronto, ON Canada
- Morton and Gloria Shulman Movement Disorder Unit and E.J. Safra Parkinson Disease Program, Neurology Division, Dept. of Medicine, Toronto Western Hospital, UHN, University of Toronto, Toronto, ON Canada
| |
Collapse
|
99
|
|
100
|
Choi Y, Ha S, Lee YS, Kim YK, Lee DS, Kim DJ. Development of tau PET Imaging Ligands and their Utility in Preclinical and Clinical Studies. Nucl Med Mol Imaging 2017; 52:24-30. [PMID: 29391909 DOI: 10.1007/s13139-017-0484-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Revised: 05/10/2017] [Accepted: 05/22/2017] [Indexed: 12/16/2022] Open
Abstract
The pathological features of Alzheimer's disease are senile plaques which are aggregates of β-amyloid peptides and neurofibrillary tangles in the brain. Neurofibrillary tangles are aggregates of hyperphosphorylated tau proteins, and these induce various other neurodegenerative diseases, such as progressive supranuclear palsy, corticobasal degeneration, frontotemporal lobar degeneration, frontotemporal dementia and parkinsonism linked to chromosome 17 (FTDP-17), and chronic traumatic encephalopathy. In the case of Alzheimer's disease, the measurement of neurofibrillary tangles associated with cognitive decline is suitable for differential diagnosis, disease progression assessment, and to monitor the effects of therapeutic treatment. This review discusses considerations for the development of tau ligands for imaging and summarizes the results of the first-in-human and preclinical studies of the tau tracers that have been developed thus far. The development of tau ligands for imaging studies will be helpful for differential diagnosis and for the development of therapeutic treatments for tauopathies including Alzheimer's disease.
Collapse
Affiliation(s)
- Yoori Choi
- 1Department of Nuclear Medicine, College of Medicine, Seoul National University, 110-744, 28 Yongon-Dong, Jongno-Gu, Seoul, South Korea.,2Department of Nuclear Medicine, Seoul National University Hospital, 28 Yongon-Dong, Jongno-Gu, Seoul, 110-744 South Korea
| | - Seunggyun Ha
- 1Department of Nuclear Medicine, College of Medicine, Seoul National University, 110-744, 28 Yongon-Dong, Jongno-Gu, Seoul, South Korea.,3Department of Molecular Medicine and Biopharmaceutical Sciences, Graduate School of Convergence Science and Technology, and College of Medicine or College of Pharmacy, Seoul National University, 03080, 103 Daehak-ro, Jongno-gu, Seoul, South Korea
| | - Yun-Sang Lee
- 1Department of Nuclear Medicine, College of Medicine, Seoul National University, 110-744, 28 Yongon-Dong, Jongno-Gu, Seoul, South Korea.,3Department of Molecular Medicine and Biopharmaceutical Sciences, Graduate School of Convergence Science and Technology, and College of Medicine or College of Pharmacy, Seoul National University, 03080, 103 Daehak-ro, Jongno-gu, Seoul, South Korea
| | - Yun Kyung Kim
- 4Institute of Brain Science, Korean Institute of Science and Technology, Hwarangno 14-gil 5, Seongbuk-gu, Seoul, 136-791 South Korea
| | - Dong Soo Lee
- 1Department of Nuclear Medicine, College of Medicine, Seoul National University, 110-744, 28 Yongon-Dong, Jongno-Gu, Seoul, South Korea.,2Department of Nuclear Medicine, Seoul National University Hospital, 28 Yongon-Dong, Jongno-Gu, Seoul, 110-744 South Korea.,3Department of Molecular Medicine and Biopharmaceutical Sciences, Graduate School of Convergence Science and Technology, and College of Medicine or College of Pharmacy, Seoul National University, 03080, 103 Daehak-ro, Jongno-gu, Seoul, South Korea
| | - Dong Jin Kim
- 4Institute of Brain Science, Korean Institute of Science and Technology, Hwarangno 14-gil 5, Seongbuk-gu, Seoul, 136-791 South Korea
| |
Collapse
|