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Ji C, Yang X, Eleish M, Jiang Y, Tetlow A, Song S, Martín-Ávila A, Wu Q, Zhou Y, Gan W, Lin Y, Sigurdsson EM. Neuronal hypofunction and network dysfunction in a mouse model at an early stage of tauopathy. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.29.591735. [PMID: 38746288 PMCID: PMC11092661 DOI: 10.1101/2024.04.29.591735] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2024]
Abstract
We previously reported altered neuronal Ca 2+ dynamics in the motor cortex of 12-month-old JNPL3 tauopathy mice during quiet wakefulness or forced running, with a tau antibody treatment significantly restoring the neuronal Ca 2+ activity profile and decreasing pathological tau in these mice 1 . Whether neuronal functional deficits occur at an early stage of tauopathy and if tau antibody treatment is effective in younger tauopathy mice needed further investigation. In addition, neuronal network activity and neuronal firing patterns have not been well studied in behaving tauopathy models. In this study, we first performed in vivo two-photon Ca 2+ imaging in JNPL3 mice in their early stage of tauopathy at 6 months of age, compared to 12 month old mice and age-matched wild-type controls to evaluate neuronal functional deficits. At the animal level, frequency of neuronal Ca 2+ transients decreased only in 6 month old tauopathy mice compared to controls, and only when animals were running on a treadmill. The amplitude of neuronal transients decreased in tauopathy mice compared to controls under resting and running conditions in both age groups. Total neuronal activity decreased only in 6 month old tauopathy mice compared to controls under resting and running conditions. Within either tauopathy or wild-type group, only total activity decreased in older wild-type animals. The tauopathy mice at different ages did not differ in neuronal Ca 2+ transient frequency, amplitude or total activity. In summary, neuronal function did significantly attenuate at an early age in tauopathy mice compared to controls but interestingly did not deteriorate between 6 and 12 months of age. A more detailed populational analysis of the pattern of Ca 2+ activity at the neuronal level in the 6 month old cohort confirmed neuronal hypoactivity in layer 2/3 of primary motor cortex, compared to wild-type controls, when animals were either resting or running on a treadmill. Despite reduced activity, neuronal Ca 2+ profiles exhibited enhanced synchrony and dysregulated responses to running stimulus. Further ex vivo electrophysiological recordings revealed reduction of spontaneous excitatory synaptic transmission onto and in pyramidal neurons and enhanced excitability of inhibitory neurons in motor cortex, which were likely responsible for altered neuronal network activity in this region. Lastly, tau antibody treatment reduced pathological tau and gliosis partially restored the neuronal Ca 2+ activity deficits but failed to rescue altered network changes. Taken together, substantial neuronal and network dysfunction occurred in the early stage of tauopathy that was partially alleviated with acute tau antibody treatment, which highlights the importance of functional assessment when evaluating the therapeutic potential of tau antibodies. Highlights Layer 2/3 motor cortical neurons exhibited hypofunction in awake and behaving mice at the early stage of tauopathy.Altered neuronal network activity disrupted local circuitry engagement in tauopathy mice during treadmill running.Layer 2/3 motor cortical neurons in tauopathy mice exhibited enhanced neuronal excitability and altered excitatory synaptic transmissions.Acute tau antibody treatment reduced pathological tau and gliosis, and partially restored neuronal hypofunction profiles but not network dysfunction.
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2
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Vandael D, Jonas P. Structure, biophysics, and circuit function of a "giant" cortical presynaptic terminal. Science 2024; 383:eadg6757. [PMID: 38452088 DOI: 10.1126/science.adg6757] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Accepted: 01/19/2024] [Indexed: 03/09/2024]
Abstract
The hippocampal mossy fiber synapse, formed between axons of dentate gyrus granule cells and dendrites of CA3 pyramidal neurons, is a key synapse in the trisynaptic circuitry of the hippocampus. Because of its comparatively large size, this synapse is accessible to direct presynaptic recording, allowing a rigorous investigation of the biophysical mechanisms of synaptic transmission and plasticity. Furthermore, because of its placement in the very center of the hippocampal memory circuit, this synapse seems to be critically involved in several higher network functions, such as learning, memory, pattern separation, and pattern completion. Recent work based on new technologies in both nanoanatomy and nanophysiology, including presynaptic patch-clamp recording, paired recording, super-resolution light microscopy, and freeze-fracture and "flash-and-freeze" electron microscopy, has provided new insights into the structure, biophysics, and network function of this intriguing synapse. This brings us one step closer to answering a fundamental question in neuroscience: how basic synaptic properties shape higher network computations.
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Affiliation(s)
- David Vandael
- Institute of Science and Technology Austria (ISTA), A-3400 Klosterneuburg, Austria
| | - Peter Jonas
- Institute of Science and Technology Austria (ISTA), A-3400 Klosterneuburg, Austria
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3
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Li X, Quan M, Wei Y, Wang W, Xu L, Wang Q, Jia J. Critical thinking of Alzheimer's transgenic mouse model: current research and future perspective. SCIENCE CHINA. LIFE SCIENCES 2023; 66:2711-2754. [PMID: 37480469 DOI: 10.1007/s11427-022-2357-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Accepted: 04/23/2023] [Indexed: 07/24/2023]
Abstract
Transgenic models are useful tools for studying the pathogenesis of and drug development for Alzheimer's Disease (AD). AD models are constructed usually using overexpression or knock-in of multiple pathogenic gene mutations from familial AD. Each transgenic model has its unique behavioral and pathological features. This review summarizes the research progress of transgenic mouse models, and their progress in the unique mechanism of amyloid-β oligomers, including the first transgenic mouse model built in China based on a single gene mutation (PSEN1 V97L) found in Chinese familial AD. We further summarized the preclinical findings of drugs using the models, and their future application in exploring the upstream mechanisms and multitarget drug development in AD.
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Affiliation(s)
- Xinyue Li
- Innovation Center for Neurological Disorders and Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, 100053, China
| | - Meina Quan
- Innovation Center for Neurological Disorders and Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, 100053, China
- National Medical Center for Neurological Diseases and National Clinical Research Center for Geriatric Diseases, Beijing, 100053, China
| | - Yiping Wei
- Innovation Center for Neurological Disorders and Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, 100053, China
| | - Wei Wang
- Innovation Center for Neurological Disorders and Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, 100053, China
- National Medical Center for Neurological Diseases and National Clinical Research Center for Geriatric Diseases, Beijing, 100053, China
| | - Lingzhi Xu
- Innovation Center for Neurological Disorders and Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, 100053, China
| | - Qi Wang
- Innovation Center for Neurological Disorders and Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, 100053, China
- National Medical Center for Neurological Diseases and National Clinical Research Center for Geriatric Diseases, Beijing, 100053, China
| | - Jianping Jia
- Innovation Center for Neurological Disorders and Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, 100053, China.
- National Medical Center for Neurological Diseases and National Clinical Research Center for Geriatric Diseases, Beijing, 100053, China.
- Beijing Key Laboratory of Geriatric Cognitive Disorders, Beijing, 100053, China.
- Clinical Center for Neurodegenerative Disease and Memory Impairment, Capital Medical University, Beijing, 100053, China.
- Center of Alzheimer's Disease, Beijing Institute of Brain Disorders, Collaborative Innovation Center for Brain Disorders, Capital Medical University, Beijing, 100053, China.
- Key Laboratory of Neurodegenerative Diseases, Ministry of Education, Beijing, 100053, China.
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4
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Longfield SF, Mollazade M, Wallis TP, Gormal RS, Joensuu M, Wark JR, van Waardenberg AJ, Small C, Graham ME, Meunier FA, Martínez-Mármol R. Tau forms synaptic nano-biomolecular condensates controlling the dynamic clustering of recycling synaptic vesicles. Nat Commun 2023; 14:7277. [PMID: 37949856 PMCID: PMC10638352 DOI: 10.1038/s41467-023-43130-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2022] [Accepted: 11/01/2023] [Indexed: 11/12/2023] Open
Abstract
Neuronal communication relies on the release of neurotransmitters from various populations of synaptic vesicles. Despite displaying vastly different release probabilities and mobilities, the reserve and recycling pool of vesicles co-exist within a single cluster suggesting that small synaptic biomolecular condensates could regulate their nanoscale distribution. Here, we performed a large-scale activity-dependent phosphoproteome analysis of hippocampal neurons in vitro and identified Tau as a highly phosphorylated and disordered candidate protein. Single-molecule super-resolution microscopy revealed that Tau undergoes liquid-liquid phase separation to generate presynaptic nanoclusters whose density and number are regulated by activity. This activity-dependent diffusion process allows Tau to translocate into the presynapse where it forms biomolecular condensates, to selectively control the mobility of recycling vesicles. Tau, therefore, forms presynaptic nano-biomolecular condensates that regulate the nanoscale organization of synaptic vesicles in an activity-dependent manner.
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Affiliation(s)
- Shanley F Longfield
- Clem Jones Centre for Ageing Dementia Research (CJCADR), Queensland Brain Institute (QBI), The University of Queensland; St Lucia Campus, Brisbane, QLD, 4072, Australia
| | - Mahdie Mollazade
- Clem Jones Centre for Ageing Dementia Research (CJCADR), Queensland Brain Institute (QBI), The University of Queensland; St Lucia Campus, Brisbane, QLD, 4072, Australia
| | - Tristan P Wallis
- Clem Jones Centre for Ageing Dementia Research (CJCADR), Queensland Brain Institute (QBI), The University of Queensland; St Lucia Campus, Brisbane, QLD, 4072, Australia
| | - Rachel S Gormal
- Clem Jones Centre for Ageing Dementia Research (CJCADR), Queensland Brain Institute (QBI), The University of Queensland; St Lucia Campus, Brisbane, QLD, 4072, Australia
| | - Merja Joensuu
- Clem Jones Centre for Ageing Dementia Research (CJCADR), Queensland Brain Institute (QBI), The University of Queensland; St Lucia Campus, Brisbane, QLD, 4072, Australia
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland; St Lucia Campus, Brisbane, QLD, 4072, Australia
| | - Jesse R Wark
- Synapse Proteomics, Children's Medical Research Institute (CMRI), The University of Sydney, 214 Hawkesbury Road, Westmead, NSW, 2145, Australia
| | | | - Christopher Small
- Clem Jones Centre for Ageing Dementia Research (CJCADR), Queensland Brain Institute (QBI), The University of Queensland; St Lucia Campus, Brisbane, QLD, 4072, Australia
| | - Mark E Graham
- Synapse Proteomics, Children's Medical Research Institute (CMRI), The University of Sydney, 214 Hawkesbury Road, Westmead, NSW, 2145, Australia
| | - Frédéric A Meunier
- Clem Jones Centre for Ageing Dementia Research (CJCADR), Queensland Brain Institute (QBI), The University of Queensland; St Lucia Campus, Brisbane, QLD, 4072, Australia.
- School of Biomedical Science, The University of Queensland; St Lucia Campus, Brisbane, QLD, 4072, Australia.
| | - Ramón Martínez-Mármol
- Clem Jones Centre for Ageing Dementia Research (CJCADR), Queensland Brain Institute (QBI), The University of Queensland; St Lucia Campus, Brisbane, QLD, 4072, Australia.
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Beck G, Yamashita R, Kido K, Ikenaka K, Chiba T, Yonenobu Y, Saito Y, Morii E, Hasegawa M, Murayama S, Mochizuki H. An autopsy case of progressive supranuclear palsy treated with monoclonal antibody against tau. Neuropathology 2023; 43:326-332. [PMID: 36593715 DOI: 10.1111/neup.12890] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Revised: 12/06/2022] [Accepted: 12/19/2022] [Indexed: 01/04/2023]
Abstract
We report an autopsy case of progressive supranuclear palsy (PSP-Richardson syndrome). The individual had been enrolled in a phase 2 trial and received a monoclonal tau antibody (tilavonemab, ABBV-8E12); he died of intrahepatic cholangiocarcinoma and gastrointestinal bleeding during the clinical trial. Neuropathological examination demonstrated neuronal loss, gliosis, and widespread deposits of phosphorylated tau in the neurofibrillary tangles, tufted astrocytes, coiled bodies, and threads, which mainly occurred in the inferior olive nucleus, dentate nucleus of the cerebellum, substantia nigra, midbrain tegmentum, subthalamic nuclei, globus pallidus, putamen, and precentral gyrus, confirming typical PSP pathology. Phosphorylated tau was also found to accumulate in Betz cells, Purkinje cells, and pencil fibers in the basal ganglia. In conclusion, no additional changes or pathological modifications, which were expected from immunotherapy targeting tau, were visible in the present case.
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Affiliation(s)
- Goichi Beck
- Department of Neurology, Osaka University Graduate School of Medicine, Suita, Japan
| | - Rika Yamashita
- Department of Neurology, Osaka University Graduate School of Medicine, Suita, Japan
| | - Kansuke Kido
- Department of Pathology, Osaka University Graduate School of Medicine, Suita, Japan
| | - Kensuke Ikenaka
- Department of Neurology, Osaka University Graduate School of Medicine, Suita, Japan
| | - Tomoya Chiba
- Department of Neurology, Osaka University Graduate School of Medicine, Suita, Japan
| | - Yuki Yonenobu
- Department of Neurology, Osaka University Graduate School of Medicine, Suita, Japan
| | - Yuko Saito
- Department of Neurology and Neuropathology (Brain Bank for Aging Research), Tokyo Metropolitan Geriatric Hospital and Institute of Gerontology, Tokyo, Japan
| | - Eiichi Morii
- Department of Pathology, Osaka University Graduate School of Medicine, Suita, Japan
| | - Masato Hasegawa
- Dementia Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Shigeo Murayama
- Department of Neurology, Osaka University Graduate School of Medicine, Suita, Japan
- Department of Neurology and Neuropathology (Brain Bank for Aging Research), Tokyo Metropolitan Geriatric Hospital and Institute of Gerontology, Tokyo, Japan
- Brain Bank for Neurodevelopmental, Neurological and Psychiatric Disorders, Molecular Research Center for Children's Mental Development, United Graduate School of Child Development, Osaka University, Suita, Japan
| | - Hideki Mochizuki
- Department of Neurology, Osaka University Graduate School of Medicine, Suita, Japan
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6
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Wu M, Chen Z, Jiang M, Bao B, Li D, Yin X, Wang X, Liu D, Zhu LQ. Friend or foe: role of pathological tau in neuronal death. Mol Psychiatry 2023; 28:2215-2227. [PMID: 36918705 DOI: 10.1038/s41380-023-02024-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Revised: 02/25/2023] [Accepted: 02/28/2023] [Indexed: 03/16/2023]
Abstract
Neuronal death is one of the most common pathological hallmarks of diverse neurological diseases, which manifest varying degrees of cognitive or motor dysfunction. Neuronal death can be classified into multiple forms with complicated and unique regulatory signaling pathways. Tau is a key microtubule-associated protein that is predominantly expressed in neurons to stabilize microtubules under physiological conditions. In contrast, pathological tau always detaches from microtubules and is implicated in a series of neurological disorders that are characterized by irreversible neuronal death, such as necrosis, apoptosis, necroptosis, pyroptosis, ferroptosis, autophagy-dependent neuronal death and phagocytosis by microglia. However, recent studies have also revealed that pathological tau can facilitate neuron escape from acute apoptosis, delay necroptosis through its action on granulovacuolar degeneration bodies (GVBs), and facilitate iron export from neurons to block ferroptosis. In this review, we briefly describe the current understanding of how pathological tau exerts dual effects on neuronal death by acting as a double-edged sword in different neurological diseases. We propose that elucidating the mechanism by which pathological tau affects neuronal death is critical for exploring novel and precise therapeutic strategies for neurological disorders.
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Affiliation(s)
- Moxin Wu
- Department of Medical Laboratory, Affiliated Hospital of Jiujiang University, Jiujiang, 332000, China
- Jiujiang Clinical Precision Medicine Research Center, Jiujiang, 332000, China
| | - Zhiying Chen
- Jiujiang Clinical Precision Medicine Research Center, Jiujiang, 332000, China
- Department of Neurology, Affiliated Hospital of Jiujiang University, Jiujiang, 332000, China
| | - Min Jiang
- Jiujiang Clinical Precision Medicine Research Center, Jiujiang, 332000, China
| | - Bing Bao
- Jiujiang Clinical Precision Medicine Research Center, Jiujiang, 332000, China
- Department of Neurology, Affiliated Hospital of Jiujiang University, Jiujiang, 332000, China
| | - Dongling Li
- Jiujiang Clinical Precision Medicine Research Center, Jiujiang, 332000, China
- Department of Neurology, Affiliated Hospital of Jiujiang University, Jiujiang, 332000, China
| | - Xiaoping Yin
- Jiujiang Clinical Precision Medicine Research Center, Jiujiang, 332000, China.
- Department of Neurology, Affiliated Hospital of Jiujiang University, Jiujiang, 332000, China.
| | - Xueren Wang
- Department of Anesthesiology, Shanxi Bethune Hospital, Taiyuan, 030032, China.
- Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.
| | - Dan Liu
- Department of Medical Genetics, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.
| | - Ling-Qiang Zhu
- Department of Pathophysiology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.
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7
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Zhang X, Li H, Ma Y, Zhong D, Hou S. Study liquid-liquid phase separation with optical microscopy: A methodology review. APL Bioeng 2023; 7:021502. [PMID: 37180732 PMCID: PMC10171890 DOI: 10.1063/5.0137008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Accepted: 04/28/2023] [Indexed: 05/16/2023] Open
Abstract
Intracellular liquid-liquid phase separation (LLPS) is a critical process involving the dynamic association of biomolecules and the formation of non-membrane compartments, playing a vital role in regulating biomolecular interactions and organelle functions. A comprehensive understanding of cellular LLPS mechanisms at the molecular level is crucial, as many diseases are linked to LLPS, and insights gained can inform drug/gene delivery processes and aid in the diagnosis and treatment of associated diseases. Over the past few decades, numerous techniques have been employed to investigate the LLPS process. In this review, we concentrate on optical imaging methods applied to LLPS studies. We begin by introducing LLPS and its molecular mechanism, followed by a review of the optical imaging methods and fluorescent probes employed in LLPS research. Furthermore, we discuss potential future imaging tools applicable to the LLPS studies. This review aims to provide a reference for selecting appropriate optical imaging methods for LLPS investigations.
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Affiliation(s)
| | | | - Yue Ma
- Institute of Systems and Physical Biology, Shenzhen Bay Laboratory, Shenzhen 518055, China
| | | | - Shangguo Hou
- Institute of Systems and Physical Biology, Shenzhen Bay Laboratory, Shenzhen 518055, China
- Authors to whom correspondence should be addressed: and
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8
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Anglada-Huguet M, Endepols H, Sydow A, Hilgers R, Neumaier B, Drzezga A, Kaniyappan S, Mandelkow E, Mandelkow EM. Reversal of Tau-Dependent Cognitive Decay by Blocking Adenosine A1 Receptors: Comparison of Transgenic Mouse Models with Different Levels of Tauopathy. Int J Mol Sci 2023; 24:ijms24119260. [PMID: 37298211 DOI: 10.3390/ijms24119260] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Revised: 05/12/2023] [Accepted: 05/12/2023] [Indexed: 06/12/2023] Open
Abstract
The accumulation of tau is a hallmark of several neurodegenerative diseases and is associated with neuronal hypoactivity and presynaptic dysfunction. Oral administration of the adenosine A1 receptor antagonist rolofylline (KW-3902) has previously been shown to reverse spatial memory deficits and to normalize the basic synaptic transmission in a mouse line expressing full-length pro-aggregant tau (TauΔK) at low levels, with late onset of disease. However, the efficacy of treatment remained to be explored for cases of more aggressive tauopathy. Using a combination of behavioral assays, imaging with several PET-tracers, and analysis of brain tissue, we compared the curative reversal of tau pathology by blocking adenosine A1 receptors in three mouse models expressing different types and levels of tau and tau mutants. We show through positron emission tomography using the tracer [18F]CPFPX (a selective A1 receptor ligand) that intravenous injection of rolofylline effectively blocks A1 receptors in the brain. Moreover, when administered to TauΔK mice, rolofylline can reverse tau pathology and synaptic decay. The beneficial effects are also observed in a line with more aggressive tau pathology, expressing the amyloidogenic repeat domain of tau (TauRDΔK) with higher aggregation propensity. Both models develop a progressive tau pathology with missorting, phosphorylation, accumulation of tau, loss of synapses, and cognitive decline. TauRDΔK causes pronounced neurofibrillary tangle assembly concomitant with neuronal death, whereas TauΔK accumulates only to tau pretangles without overt neuronal loss. A third model tested, the rTg4510 line, has a high expression of mutant TauP301L and hence a very aggressive phenotype starting at ~3 months of age. This line failed to reverse pathology upon rolofylline treatment, consistent with a higher accumulation of tau-specific PET tracers and inflammation. In conclusion, blocking adenosine A1 receptors by rolofylline can reverse pathology if the pathological potential of tau remains below a threshold value that depends on concentration and aggregation propensity.
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Affiliation(s)
- Marta Anglada-Huguet
- German Center for Neurodegenerative Diseases (DZNE), Building 99, Venusberg Campus 1, 53127 Bonn, Germany
| | - Heike Endepols
- Institute of Radiochemistry and Experimental Molecular Imaging, Faculty of Medicine and University Hospital Cologne, University of Cologne, 50937 Cologne, Germany
- Department of Nuclear Medicine, Faculty of Medicine and University Hospital Cologne, University of Cologne, 50923 Cologne, Germany
- Forschungszentrum Jülich GmbH, Institute of Neuroscience and Medicine, Nuclear Chemistry (INM-5), Wilhelm-Johnen-Straße, 52428 Jülich, Germany
| | - Astrid Sydow
- German Center for Neurodegenerative Diseases (DZNE), Building 99, Venusberg Campus 1, 53127 Bonn, Germany
| | - Ronja Hilgers
- German Center for Neurodegenerative Diseases (DZNE), Building 99, Venusberg Campus 1, 53127 Bonn, Germany
| | - Bernd Neumaier
- Institute of Radiochemistry and Experimental Molecular Imaging, Faculty of Medicine and University Hospital Cologne, University of Cologne, 50937 Cologne, Germany
- Forschungszentrum Jülich GmbH, Institute of Neuroscience and Medicine, Nuclear Chemistry (INM-5), Wilhelm-Johnen-Straße, 52428 Jülich, Germany
- Max Planck Institute for Metabolism Research, 50931 Cologne, Germany
| | - Alexander Drzezga
- German Center for Neurodegenerative Diseases (DZNE), Building 99, Venusberg Campus 1, 53127 Bonn, Germany
- Department of Nuclear Medicine, Faculty of Medicine and University Hospital Cologne, University of Cologne, 50923 Cologne, Germany
- Forschungszentrum Jülich GmbH, Institute of Neuroscience and Medicine, Molecular Organization of the Brain (INM-2), Wilhelm-Johnen-Straße, 52428 Jülich, Germany
| | - Senthilvelrajan Kaniyappan
- German Center for Neurodegenerative Diseases (DZNE), Building 99, Venusberg Campus 1, 53127 Bonn, Germany
- MPI Neurobiology Behavior-caesar, Ludwig-Erhard-Allee 2, 53175 Bonn, Germany
- Department of Neurodegenerative Diseases and Geriatric Psychiatry, University of Bonn, 53127 Bonn, Germany
| | - Eckhard Mandelkow
- German Center for Neurodegenerative Diseases (DZNE), Building 99, Venusberg Campus 1, 53127 Bonn, Germany
- MPI Neurobiology Behavior-caesar, Ludwig-Erhard-Allee 2, 53175 Bonn, Germany
- Department of Neurodegenerative Diseases and Geriatric Psychiatry, University of Bonn, 53127 Bonn, Germany
| | - Eva-Maria Mandelkow
- German Center for Neurodegenerative Diseases (DZNE), Building 99, Venusberg Campus 1, 53127 Bonn, Germany
- MPI Neurobiology Behavior-caesar, Ludwig-Erhard-Allee 2, 53175 Bonn, Germany
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9
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Meftah S, Gan J. Alzheimer’s disease as a synaptopathy: Evidence for dysfunction of synapses during disease progression. Front Synaptic Neurosci 2023; 15:1129036. [PMID: 36970154 PMCID: PMC10033629 DOI: 10.3389/fnsyn.2023.1129036] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Accepted: 02/23/2023] [Indexed: 03/11/2023] Open
Abstract
The synapse has consistently been considered a vulnerable and critical target within Alzheimer’s disease, and synapse loss is, to date, one of the main biological correlates of cognitive decline within Alzheimer’s disease. This occurs prior to neuronal loss with ample evidence that synaptic dysfunction precedes this, in support of the idea that synaptic failure is a crucial stage within disease pathogenesis. The two main pathological hallmarks of Alzheimer’s disease, abnormal aggregates of amyloid or tau proteins, have had demonstrable effects on synaptic physiology in animal and cellular models of Alzheimer’s disease. There is also growing evidence that these two proteins may have a synergistic effect on neurophysiological dysfunction. Here, we review some of the main findings of synaptic alterations in Alzheimer’s disease, and what we know from Alzheimer’s disease animal and cellular models. First, we briefly summarize some of the human evidence to suggest that synapses are altered, including how this relates to network activity. Subsequently, animal and cellular models of Alzheimer’s disease are considered, highlighting mouse models of amyloid and tau pathology and the role these proteins may play in synaptic dysfunction, either in isolation or examining how the two pathologies may interact in dysfunction. This specifically focuses on neurophysiological function and dysfunction observed within these animal models, typically measured using electrophysiology or calcium imaging. Following synaptic dysfunction and loss, it would be impossible to imagine that this would not alter oscillatory activity within the brain. Therefore, this review also discusses how this may underpin some of the aberrant oscillatory patterns seen in animal models of Alzheimer’s disease and human patients. Finally, an overview of some key directions and considerations in the field of synaptic dysfunction in Alzheimer’s disease is covered. This includes current therapeutics that are targeted specifically at synaptic dysfunction, but also methods that modulate activity to rescue aberrant oscillatory patterns. Other important future avenues of note in this field include the role of non-neuronal cell types such as astrocytes and microglia, and mechanisms of dysfunction independent of amyloid and tau in Alzheimer’s disease. The synapse will certainly continue to be an important target within Alzheimer’s disease for the foreseeable future.
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Affiliation(s)
- Soraya Meftah
- UK Dementia Research Institute, The University of Edinburgh, Edinburgh, United Kingdom
- Centre for Discovery Brain Sciences, The University of Edinburgh, Edinburgh, United Kingdom
| | - Jian Gan
- UK Dementia Research Institute, The University of Edinburgh, Edinburgh, United Kingdom
- Centre for Discovery Brain Sciences, The University of Edinburgh, Edinburgh, United Kingdom
- *Correspondence: Jian Gan,
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10
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Tzioras M, McGeachan RI, Durrant CS, Spires-Jones TL. Synaptic degeneration in Alzheimer disease. Nat Rev Neurol 2023; 19:19-38. [PMID: 36513730 DOI: 10.1038/s41582-022-00749-z] [Citation(s) in RCA: 109] [Impact Index Per Article: 109.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/04/2022] [Indexed: 12/15/2022]
Abstract
Alzheimer disease (AD) is characterized by progressive cognitive decline in older individuals accompanied by the presence of two pathological protein aggregates - amyloid-β and phosphorylated tau - in the brain. The disease results in brain atrophy caused by neuronal loss and synapse degeneration. Synaptic loss strongly correlates with cognitive decline in both humans and animal models of AD. Indeed, evidence suggests that soluble forms of amyloid-β and tau can cause synaptotoxicity and spread through neural circuits. These pathological changes are accompanied by an altered phenotype in the glial cells of the brain - one hypothesis is that glia excessively ingest synapses and modulate the trans-synaptic spread of pathology. To date, effective therapies for the treatment or prevention of AD are lacking, but understanding how synaptic degeneration occurs will be essential for the development of new interventions. Here, we highlight the mechanisms through which synapses degenerate in the AD brain, and discuss key questions that still need to be answered. We also cover the ways in which our understanding of the mechanisms of synaptic degeneration is leading to new therapeutic approaches for AD.
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Affiliation(s)
- Makis Tzioras
- Centre for Discovery Brain Sciences, The University of Edinburgh, Edinburgh, UK.,UK Dementia Research Institute, The University of Edinburgh, Edinburgh, UK
| | - Robert I McGeachan
- Centre for Discovery Brain Sciences, The University of Edinburgh, Edinburgh, UK.,UK Dementia Research Institute, The University of Edinburgh, Edinburgh, UK.,The Hospital for Small Animals, Royal (Dick) School of Veterinary Studies, The University of Edinburgh, Edinburgh, UK
| | - Claire S Durrant
- Centre for Discovery Brain Sciences, The University of Edinburgh, Edinburgh, UK.,UK Dementia Research Institute, The University of Edinburgh, Edinburgh, UK
| | - Tara L Spires-Jones
- Centre for Discovery Brain Sciences, The University of Edinburgh, Edinburgh, UK. .,UK Dementia Research Institute, The University of Edinburgh, Edinburgh, UK.
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11
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Dong R, Lv P, Han Y, Jiang L, Wang Z, Peng L, Ma Z, Xia T, Zhang B, Gu X. Enhancement of astrocytic gap junctions Connexin43 coupling can improve long-term isoflurane anesthesia-mediated brain network abnormalities and cognitive impairment. CNS Neurosci Ther 2022; 28:2281-2297. [PMID: 36153812 PMCID: PMC9627365 DOI: 10.1111/cns.13974] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Revised: 08/31/2022] [Accepted: 09/03/2022] [Indexed: 02/06/2023] Open
Abstract
AIM Astrocytes are connected by gap junctions Connexin43 (GJs-Cx43) forming an extensive intercellular network and maintain brain homeostasis. Perioperative neurocognitive disorder (PND) occurs frequently after anesthesia/surgery and worsens patient outcome, but the neural circuit mechanisms remain unclear. This study aimed to determine the effects of the GJs-Cx43-mediated astrocytic network on PND and ascertain the underlying neural circuit mechanism. METHODS Male C57BL/6 mice were treated with long-term isoflurane exposure to construct a mouse model of PND. We also exposed primary mouse astrocytes to long-term isoflurane exposure to simulate the conditions of in vivo cognitive dysfunction. Behavioral tests were performed using the Y-maze and fear conditioning (FC) tests. Manganese-enhanced magnetic resonance imaging (MEMRI) and resting-state functional magnetic resonance imaging (rs-fMRI) were used to investigate brain activity and functional connectivity. Western blot and flow cytometry analysis were used to assess protein expression. RESULTS Reconfiguring the astrocytic network by increasing GJs-Cx43 expression can modulate 22 subregions affected by PND in three ways: reversed activation, reversed inhibition, and intensified activation. The brain functional connectivity analysis further suggests that PND is a brain network disorder that includes sleep-wake rhythm-related brain regions, contextual and fear memory-related subregions, the hippocampal-amygdala circuit, the septo-hippocampal circuit, and the entorhinal-hippocampal circuit. Notably, remodeling the astrocytic network by upregulation of GJs-Cx43 can partially reverse the abnormalities in the above circuits. Pathophysiological degeneration in hippocampus is one of the primary hallmarks of PND pathology, and long-term isoflurane anesthesia contributes to oxidative stress and neuroinflammation in the hippocampus. However, promoting the formation of GJs-Cx43 ameliorated cognitive dysfunction induced by long-term isoflurane anesthesia through the attenuation of oxidative stress in hippocampus. CONCLUSION Enhancing GJs-Cx43 coupling can improve brain network abnormalities and cognitive impairment induced by long-term isoflurane anesthesia, its mechanisms might be associated with the regulation of oxidative stress and neuroinflammation.
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Affiliation(s)
- Rui Dong
- Department of AnesthesiologyThe Affiliated Drum Tower Hospital of Nanjing University Medical SchoolNanjingChina
| | - Pin Lv
- Department of RadiologyThe Affiliated Drum Tower Hospital of Nanjing University Medical SchoolNanjingChina
| | - Yuqiang Han
- Department of AnesthesiologyThe Affiliated Drum Tower Hospital of Nanjing University Medical SchoolNanjingChina
| | - Linhao Jiang
- Department of AnesthesiologyThe Affiliated Drum Tower Hospital of Nanjing University Medical SchoolNanjingChina
| | - Zimo Wang
- Department of AnesthesiologyThe Affiliated Drum Tower Hospital of Nanjing University Medical SchoolNanjingChina
| | - Liangyu Peng
- Department of AnesthesiologyThe Affiliated Drum Tower Hospital of Nanjing University Medical SchoolNanjingChina
| | - Zhengliang Ma
- Department of AnesthesiologyThe Affiliated Drum Tower Hospital of Nanjing University Medical SchoolNanjingChina
| | - Tianjiao Xia
- Medical SchoolNanjing UniversityNanjingChina,Jiangsu Key Laboratory of Molecular MedicineNanjingChina
| | - Bing Zhang
- Department of RadiologyThe Affiliated Drum Tower Hospital of Nanjing University Medical SchoolNanjingChina,Jiangsu Key Laboratory of Molecular MedicineNanjingChina,Institute of Medical Imaging and Artificial IntelligenceNanjing UniversityNanjingChina,Institute of Brain ScienceNanjing UniversityNanjingChina
| | - Xiaoping Gu
- Department of AnesthesiologyThe Affiliated Drum Tower Hospital of Nanjing University Medical SchoolNanjingChina
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12
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Congdon EE, Jiang Y, Sigurdsson EM. Targeting tau only extracellularly is likely to be less efficacious than targeting it both intra- and extracellularly. Semin Cell Dev Biol 2022; 126:125-137. [PMID: 34896021 PMCID: PMC9680670 DOI: 10.1016/j.semcdb.2021.12.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Revised: 12/01/2021] [Accepted: 12/01/2021] [Indexed: 12/11/2022]
Abstract
Aggregation of the tau protein is thought to be responsible for the neurodegeneration and subsequent functional impairments in diseases that are collectively named tauopathies. Alzheimer's disease is the most common tauopathy, but the group consists of over 20 different diseases, many of which have tau pathology as their primary feature. The development of tau therapies has mainly focused on preventing the formation of and/or clearing these aggregates. Of these, immunotherapies that aim to either elicit endogenous tau antibodies or deliver exogenous ones are the most common approach in clinical trials. While their mechanism of action can involve several pathways, both extra- and intracellular, pharmaceutical companies have primarily focused on antibody-mediated clearance of extracellular tau. As we have pointed out over the years, this is rather surprising because it is well known that most of pathological tau protein is found intracellularly. It has been repeatedly shown by several groups over the past decades that antibodies can enter neurons and that their cellular uptake can be enhanced by various means, particularly by altering their charge. Here, we will briefly describe the potential extra- and intracellular mechanisms involved in antibody-mediated clearance of tau pathology, discuss these in the context of recent failures of some of the tau antibody trials, and finally provide a brief overview of how the intracellular efficacy of tau antibodies can potentially be further improved by certain modifications that aim to enhance tau clearance via specific intracellular degradation pathways.
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Affiliation(s)
- Erin E Congdon
- Department of Neuroscience and Physiology, Neuroscience Institute, New York University Grossman School of Medicine, New York, NY 10016, United States.
| | - Yixiang Jiang
- Department of Neuroscience and Physiology, Neuroscience Institute, New York University Grossman School of Medicine, New York, NY 10016, United States
| | - Einar M Sigurdsson
- Department of Neuroscience and Physiology, Neuroscience Institute, New York University Grossman School of Medicine, New York, NY 10016, United States; Department of Psychiatry, New York University Grossman School of Medicine, New York, NY 10016, United States.
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13
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Marshall CA, McBride JD, Changolkar L, Riddle DM, Trojanowski JQ, Lee VMY. Inhibition of CK2 mitigates Alzheimer's tau pathology by preventing NR2B synaptic mislocalization. Acta Neuropathol Commun 2022; 10:30. [PMID: 35246269 PMCID: PMC8895919 DOI: 10.1186/s40478-022-01331-w] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Accepted: 02/11/2022] [Indexed: 12/15/2022] Open
Abstract
Alzheimer’s disease (AD) is a neurodegenerative disorder that exhibits pathological changes in both tau and synaptic function. AD patients display increases in hyperphosphorylated tau and synaptic activity. Previous studies have individually identified the role of NR2B subunit-containing NMDA receptors in AD related synaptic dysfunction and aggregated tau without reconciling the conflicting differences and implications of NR2B expression. Inhibition of extrasynaptically located NR2B mitigates tau pathology in AD models, whereas the inhibition of synaptic NR2B replicates tau-associated hyperactivity. This suggests that a simultaneous increase in extrasynaptic NR2B and decrease in synaptic NR2B may be responsible for tau pathology and synaptic dysfunction, respectively. The synaptic location of NR2B is regulated by casein kinase 2 (CK2), which is highly expressed in AD patients. Here, we used patient brains diagnosed with AD, corticobasal degeneration, progressive supranuclear palsy or Pick’s disease to characterize CK2 expression across these diverse tauopathies. Human derived material was also utilized in conjunction with cultured hippocampal neurons in order to investigate AD-induced changes in NR2B location. We further assessed the therapeutic effect of CK2 inhibition on NR2B synaptic distribution and tau pathology. We found that aberrant expression of CK2, and synaptically translocated NR2B, is unique to AD patients compared to other tauopathies. Increased CK2 was also observed in AD-tau treated neurons in addition to the mislocalization of NR2B receptors. Tau burden was alleviated in vitro by correcting synaptic:extrasynaptic NR2B function. Restoring NR2B physiological expression patterns with CK2 inhibition and inhibiting the function of excessive extrasynaptic NR2B with Memantine both mitigated tau accumulation in vitro. However, the combined pharmacological treatment promoted the aggregation of tau. Our data suggests that the synaptic:extrasynaptic balance of NR2B function regulates AD-tau pathogenesis, and that the inhibition of CK2, and concomitant prevention of NR2B mislocalization, may be a useful therapeutic tool for AD patients.
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14
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Aillaud I, Kaniyappan S, Chandupatla RR, Ramirez LM, Alkhashrom S, Eichler J, Horn AHC, Zweckstetter M, Mandelkow E, Sticht H, Funke SA. A novel D-amino acid peptide with therapeutic potential (ISAD1) inhibits aggregation of neurotoxic disease-relevant mutant Tau and prevents Tau toxicity in vitro. Alzheimers Res Ther 2022; 14:15. [PMID: 35063014 PMCID: PMC8783508 DOI: 10.1186/s13195-022-00959-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Accepted: 01/06/2022] [Indexed: 12/19/2022]
Abstract
Background Alzheimer’s disease (AD), the most common form of dementia, is a progressive neurodegenerative disorder that mainly affects older adults. One of the pathological hallmarks of AD is abnormally aggregated Tau protein that forms fibrillar deposits in the brain. In AD, Tau pathology correlates strongly with clinical symptoms, cognitive dysfunction, and neuronal death. Methods We aimed to develop novel therapeutic D-amino acid peptides as Tau fibrillization inhibitors. It has been previously demonstrated that D-amino acid peptides are protease stable and less immunogenic than L-peptides, and these characteristics may render them suitable for in vivo applications. Using a phage display procedure against wild type full-length Tau (TauFL), we selected a novel Tau binding L-peptide and synthesized its D-amino acid version ISAD1 and its retro inversed form, ISAD1rev, respectively. Results While ISAD1rev inhibited Tau aggregation only moderately, ISAD1 bound to Tau in the aggregation-prone PHF6 region and inhibited fibrillization of TauFL, disease-associated mutant full-length Tau (TauFLΔK, TauFL-A152T, TauFL-P301L), and pro-aggregant repeat domain Tau mutant (TauRDΔK). ISAD1 and ISAD1rev induced the formation of large high molecular weight TauFL and TauRDΔK oligomers that lack proper Thioflavin-positive β-sheet conformation even at lower concentrations. In silico modeling of ISAD1 Tau interaction at the PHF6 site revealed a binding mode similar to those known for other PHF6 binding peptides. Cell culture experiments demonstrated that ISAD1 and its inverse form are taken up by N2a-TauRDΔK cells efficiently and prevent cytotoxicity of externally added Tau fibrils as well as of internally expressed TauRDΔK. Conclusions ISAD1 and related peptides may be suitable for therapy development of AD by promoting off-pathway assembly of Tau, thus preventing its toxicity. Supplementary Information The online version contains supplementary material available at 10.1186/s13195-022-00959-z.
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Affiliation(s)
- Isabelle Aillaud
- Institute of Bioanalysis, Coburg University of Applied Sciences, Coburg, Germany
| | - Senthilvelrajan Kaniyappan
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany.,Department of Neurodegenerative Diseases and Geriatric Psychiatry, University of Bonn, Bonn, Germany
| | | | - Lisa Marie Ramirez
- Forschungsgruppe Translationale Strukturbiologie, Deutsches Zentrum für Neurodegenerative Erkrankungen (DZNE), Göttingen, Germany
| | - Sewar Alkhashrom
- Institut für Chemie und Pharmazie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Jutta Eichler
- Institut für Chemie und Pharmazie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Anselm H C Horn
- Bioinformatik, Institut für Biochemie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany.,Institut für Medizinische Genetik, Universität Zürich, Zürich, Switzerland
| | - Markus Zweckstetter
- Forschungsgruppe Translationale Strukturbiologie, Deutsches Zentrum für Neurodegenerative Erkrankungen (DZNE), Göttingen, Germany.,Abteilung für NMR-basierte Strukturbiologie, Max-Planck-Institut für Biophysikalische Chemie, Göttingen, Germany
| | - Eckhard Mandelkow
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany.,Department of Neurodegenerative Diseases and Geriatric Psychiatry, University of Bonn, Bonn, Germany.,CAESAR Research Center, Bonn, Germany
| | - Heinrich Sticht
- Bioinformatik, Institut für Biochemie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Susanne Aileen Funke
- Institute of Bioanalysis, Coburg University of Applied Sciences, Coburg, Germany.
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15
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Zhu MH, Jogdand AH, Jang J, Nagella SC, Das B, Milosevic MM, Yan R, Antic SD. Evoked Cortical Depolarizations Before and After the Amyloid Plaque Accumulation: Voltage Imaging Study. J Alzheimers Dis 2022; 88:1443-1458. [PMID: 35811528 PMCID: PMC10493004 DOI: 10.3233/jad-220249] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND In Alzheimer's disease (AD), synaptic dysfunction is thought to occur many years before the onset of cognitive decline. OBJECTIVE Detecting synaptic dysfunctions at the earliest stage of AD would be desirable in both clinic and research settings. METHODS Population voltage imaging allows monitoring of synaptic depolarizations, to which calcium imaging is relatively blind. We developed an AD mouse model (APPswe/PS1dE9 background) expressing a genetically-encoded voltage indicator (GEVI) in the neocortex. GEVI was restricted to the excitatory pyramidal neurons (unlike the voltage-sensitive dyes). RESULTS Expression of GEVI did not disrupt AD model formation of amyloid plaques. GEVI expression was stable in both AD model mice and Control (healthy) littermates (CTRL) over 247 days postnatal. Brain slices were stimulated in layer 2/3. From the evoked voltage waveforms, we extracted several parameters for comparison AD versus CTRL. Some parameters (e.g., temporal summation, refractoriness, and peak latency) were weak predictors, while other parameters (e.g., signal amplitude, attenuation with distance, and duration (half-width) of the evoked transients) were stronger predictors of the AD condition. Around postnatal age 150 days (P150) and especially at P200, synaptically-evoked voltage signals in brain slices were weaker in the AD groups versus the age- and sex-matched CTRL groups, suggesting an AD-mediated synaptic weakening that coincides with the accumulation of plaques. However, at the youngest ages examined, P40 and P80, the AD groups showed differentially stronger signals, suggesting "hyperexcitability" prior to the formation of plaques. CONCLUSION Our results indicate bidirectional alterations in cortical physiology in AD model mice; occurring both prior (P40-80), and after (P150-200) the amyloid deposition.
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Affiliation(s)
- Mei Hong Zhu
- Department of Neuroscience, UConn Health, School of Medicine, Farmington, CT, USA
| | - Aditi H Jogdand
- Department of Neuroscience, UConn Health, School of Medicine, Farmington, CT, USA
| | - Jinyoung Jang
- Department of Neuroscience, UConn Health, School of Medicine, Farmington, CT, USA
| | - Sai C Nagella
- Department of Neuroscience, UConn Health, School of Medicine, Farmington, CT, USA
| | - Brati Das
- Department of Neuroscience, UConn Health, School of Medicine, Farmington, CT, USA
| | - Milena M Milosevic
- Department of Neuroscience, UConn Health, School of Medicine, Farmington, CT, USA
| | - Riqiang Yan
- Department of Neuroscience, UConn Health, School of Medicine, Farmington, CT, USA
| | - Srdjan D Antic
- Department of Neuroscience, UConn Health, School of Medicine, Farmington, CT, USA
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16
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Wu M, Zhang M, Yin X, Chen K, Hu Z, Zhou Q, Cao X, Chen Z, Liu D. The role of pathological tau in synaptic dysfunction in Alzheimer's diseases. Transl Neurodegener 2021; 10:45. [PMID: 34753506 PMCID: PMC8579533 DOI: 10.1186/s40035-021-00270-1] [Citation(s) in RCA: 59] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Accepted: 10/25/2021] [Indexed: 12/12/2022] Open
Abstract
Alzheimer’s disease (AD) is a neurodegenerative disease characterized by progressive cognitive decline, accompanied by amyloid-β (Aβ) overload and hyperphosphorylated tau accumulation in the brain. Synaptic dysfunction, an important pathological hallmark in AD, is recognized as the main cause of the cognitive impairments. Accumulating evidence suggests that synaptic dysfunction could be an early pathological event in AD. Pathological tau, which is detached from axonal microtubules and mislocalized into pre- and postsynaptic neuronal compartments, is suggested to induce synaptic dysfunction in several ways, including reducing mobility and release of presynaptic vesicles, decreasing glutamatergic receptors, impairing the maturation of dendritic spines at postsynaptic terminals, disrupting mitochondrial transport and function in synapses, and promoting the phagocytosis of synapses by microglia. Here, we review the current understanding of how pathological tau mediates synaptic dysfunction and contributes to cognitive decline in AD. We propose that elucidating the mechanism by which pathological tau impairs synaptic function is essential for exploring novel therapeutic strategies for AD.
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Affiliation(s)
- Moxin Wu
- Department of Medical Laboratory, Affiliated Hospital of Jiujiang University, Jiujiang, 332000, China.,Jiujiang Clinical Precision Medicine Research Center, Jiujiang, 332000, China
| | - Manqing Zhang
- Medical College of Jiujiang University, Jiujiang, 332000, China
| | - Xiaoping Yin
- Jiujiang Clinical Precision Medicine Research Center, Jiujiang, 332000, China.,Department of Neurology, Affiliated Hospital of Jiujiang University, Jiujiang, 332000, China
| | - Kai Chen
- Department of Dermatology, Wuhan No. 1 Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
| | - Zhijian Hu
- Department of Medical Laboratory, Affiliated Hospital of Jiujiang University, Jiujiang, 332000, China
| | - Qin Zhou
- Jiujiang Clinical Precision Medicine Research Center, Jiujiang, 332000, China
| | - Xianming Cao
- Jiujiang Clinical Precision Medicine Research Center, Jiujiang, 332000, China.,Department of Neurology, Affiliated Hospital of Jiujiang University, Jiujiang, 332000, China
| | - Zhiying Chen
- Jiujiang Clinical Precision Medicine Research Center, Jiujiang, 332000, China. .,Department of Neurology, Affiliated Hospital of Jiujiang University, Jiujiang, 332000, China.
| | - Dan Liu
- Department of Medical Genetics, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.
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17
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Super-resolution microscopy: a closer look at synaptic dysfunction in Alzheimer disease. Nat Rev Neurosci 2021; 22:723-740. [PMID: 34725519 DOI: 10.1038/s41583-021-00531-y] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/27/2021] [Indexed: 11/08/2022]
Abstract
The synapse has emerged as a critical neuronal structure in the degenerative process of Alzheimer disease (AD), in which the pathogenic signals of two key players - amyloid-β (Aβ) and tau - converge, thereby causing synaptic dysfunction and cognitive deficits. The synapse presents a dynamic, confined microenvironment in which to explore how key molecules travel, localize, interact and assume different levels of organizational complexity, thereby affecting neuronal function. However, owing to their small size and the diffraction-limited resolution of conventional light microscopic approaches, investigating synaptic structure and dynamics has been challenging. Super-resolution microscopy (SRM) techniques have overcome the resolution barrier and are revolutionizing our quantitative understanding of biological systems in unprecedented spatio-temporal detail. Here we review critical new insights provided by SRM into the molecular architecture and dynamic organization of the synapse and, in particular, the interactions between Aβ and tau in this compartment. We further highlight how SRM can transform our understanding of the molecular pathological mechanisms that underlie AD. The application of SRM for understanding the roles of synapses in AD pathology will provide a stepping stone towards a broader understanding of dysfunction in other subcellular compartments and at cellular and circuit levels in this disease.
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18
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Robbins M, Clayton E, Kaminski Schierle GS. Synaptic tau: A pathological or physiological phenomenon? Acta Neuropathol Commun 2021; 9:149. [PMID: 34503576 PMCID: PMC8428049 DOI: 10.1186/s40478-021-01246-y] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Accepted: 08/12/2021] [Indexed: 12/17/2022] Open
Abstract
In this review, we discuss the synaptic aspects of Tau pathology occurring during Alzheimer's disease (AD) and how this may relate to memory impairment, a major hallmark of AD. Whilst the clinical diagnosis of AD patients is a loss of working memory and long-term declarative memory, the histological diagnosis is the presence of neurofibrillary tangles of hyperphosphorylated Tau and Amyloid-beta plaques. Tau pathology spreads through synaptically connected neurons to impair synaptic function preceding the formation of neurofibrillary tangles, synaptic loss, axonal retraction and cell death. Alongside synaptic pathology, recent data suggest that Tau has physiological roles in the pre- or post- synaptic compartments. Thus, we have seen a shift in the research focus from Tau as a microtubule-stabilising protein in axons, to Tau as a synaptic protein with roles in accelerating spine formation, dendritic elongation, and in synaptic plasticity coordinating memory pathways. We collate here the myriad of emerging interactions and physiological roles of synaptic Tau, and discuss the current evidence that synaptic Tau contributes to pathology in AD.
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19
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Schwab K, Melis V, Harrington CR, Wischik CM, Magbagbeolu M, Theuring F, Riedel G. Proteomic Analysis of Hydromethylthionine in the Line 66 Model of Frontotemporal Dementia Demonstrates Actions on Tau-Dependent and Tau-Independent Networks. Cells 2021; 10:2162. [PMID: 34440931 PMCID: PMC8391171 DOI: 10.3390/cells10082162] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Revised: 08/16/2021] [Accepted: 08/19/2021] [Indexed: 12/21/2022] Open
Abstract
Abnormal aggregation of tau is the pathological hallmark of tauopathies including frontotemporal dementia (FTD). We have generated tau-transgenic mice that express the aggregation-prone P301S human tau (line 66). These mice present with early-onset, high tau load in brain and FTD-like behavioural deficiencies. Several of these behavioural phenotypes and tau pathology are reversed by treatment with hydromethylthionine but key pathways underlying these corrections remain elusive. In two proteomic experiments, line 66 mice were compared with wild-type mice and then vehicle and hydromethylthionine treatments of line 66 mice were compared. The brain proteome was investigated using two-dimensional electrophoresis and mass spectrometry to identify protein networks and pathways that were altered due to tau overexpression or modified by hydromethylthionine treatment. Overexpression of mutant tau induced metabolic/mitochondrial dysfunction, changes in synaptic transmission and in stress responses, and these functions were recovered by hydromethylthionine. Other pathways, such as NRF2, oxidative phosphorylation and protein ubiquitination were activated by hydromethylthionine, presumably independent of its function as a tau aggregation inhibitor. Our results suggest that hydromethylthionine recovers cellular activity in both a tau-dependent and a tau-independent fashion that could lead to a wide-spread improvement of homeostatic function in the FTD brain.
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Affiliation(s)
- Karima Schwab
- School of Medicine, Medical Sciences and Nutrition, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, UK; (K.S.); (V.M.); (C.R.H.); (C.M.W.)
- Charité—Universitätsmedizin Berlin, Hessische Str. 3-4, 10115 Berlin, Germany; (M.M.); (F.T.)
| | - Valeria Melis
- School of Medicine, Medical Sciences and Nutrition, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, UK; (K.S.); (V.M.); (C.R.H.); (C.M.W.)
| | - Charles R. Harrington
- School of Medicine, Medical Sciences and Nutrition, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, UK; (K.S.); (V.M.); (C.R.H.); (C.M.W.)
- TauRx Therapeutics Ltd., 395 King Street, Aberdeen AB24 5RP, UK
| | - Claude M. Wischik
- School of Medicine, Medical Sciences and Nutrition, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, UK; (K.S.); (V.M.); (C.R.H.); (C.M.W.)
- TauRx Therapeutics Ltd., 395 King Street, Aberdeen AB24 5RP, UK
| | - Mandy Magbagbeolu
- Charité—Universitätsmedizin Berlin, Hessische Str. 3-4, 10115 Berlin, Germany; (M.M.); (F.T.)
| | - Franz Theuring
- Charité—Universitätsmedizin Berlin, Hessische Str. 3-4, 10115 Berlin, Germany; (M.M.); (F.T.)
| | - Gernot Riedel
- School of Medicine, Medical Sciences and Nutrition, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, UK; (K.S.); (V.M.); (C.R.H.); (C.M.W.)
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20
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Niewiadomska G, Niewiadomski W, Steczkowska M, Gasiorowska A. Tau Oligomers Neurotoxicity. Life (Basel) 2021; 11:28. [PMID: 33418848 PMCID: PMC7824853 DOI: 10.3390/life11010028] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Revised: 12/31/2020] [Accepted: 01/04/2021] [Indexed: 12/11/2022] Open
Abstract
Although the mechanisms of toxic activity of tau are not fully recognized, it is supposed that the tau toxicity is related rather not to insoluble tau aggregates but to its intermediate forms. It seems that neurofibrillar tangles (NFTs) themselves, despite being composed of toxic tau, are probably neither necessary nor sufficient for tau-induced neuronal dysfunction and toxicity. Tau oligomers (TauOs) formed during the early stages of tau aggregation are the pathological forms that play a key role in eliciting the loss of neurons and behavioral impairments in several neurodegenerative disorders called tauopathies. They can be found in tauopathic diseases, the most common of which is Alzheimer's disease (AD). Evidence of co-occurrence of b-amyloid, α-synuclein, and tau into their most toxic forms, i.e., oligomers, suggests that these species interact and influence each other's aggregation in several tauopathies. The mechanism responsible for oligomeric tau neurotoxicity is a subject of intensive investigation. In this review, we summarize the most recent literature on the damaging effect of TauOs on the stability of the genome and the function of the nucleus, energy production and mitochondrial function, cell signaling and synaptic plasticity, the microtubule assembly, neuronal cytoskeleton and axonal transport, and the effectiveness of the protein degradation system.
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Affiliation(s)
- Grazyna Niewiadomska
- Nencki Institute of Experimental Biology, Polish Academy of Sciences, 02-093 Warsaw, Poland
| | - Wiktor Niewiadomski
- Mossakowski Medical Research Centre, Polish Academy of Sciences, 02-106 Warsaw, Poland; (W.N.); (M.S.); (A.G.)
| | - Marta Steczkowska
- Mossakowski Medical Research Centre, Polish Academy of Sciences, 02-106 Warsaw, Poland; (W.N.); (M.S.); (A.G.)
| | - Anna Gasiorowska
- Mossakowski Medical Research Centre, Polish Academy of Sciences, 02-106 Warsaw, Poland; (W.N.); (M.S.); (A.G.)
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21
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Lemke N, Melis V, Lauer D, Magbagbeolu M, Neumann B, Harrington CR, Riedel G, Wischik CM, Theuring F, Schwab K. Differential compartmental processing and phosphorylation of pathogenic human tau and native mouse tau in the line 66 model of frontotemporal dementia. J Biol Chem 2020; 295:18508-18523. [PMID: 33127647 PMCID: PMC7939472 DOI: 10.1074/jbc.ra120.014890] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 10/09/2020] [Indexed: 12/23/2022] Open
Abstract
Synapse loss is associated with motor and cognitive decline in multiple neurodegenerative disorders, and the cellular redistribution of tau is related to synaptic impairment in tauopathies, such as Alzheimer's disease and frontotemporal dementia. Here, we examined the cellular distribution of tau protein species in human tau overexpressing line 66 mice, a transgenic mouse model akin to genetic variants of frontotemporal dementia. Line 66 mice express intracellular tau aggregates in multiple brain regions and exhibit sensorimotor and motor learning deficiencies. Using a series of anti-tau antibodies, we observed, histologically, that nonphosphorylated transgenic human tau is enriched in synapses, whereas phosphorylated tau accumulates predominantly in cell bodies and axons. Subcellular fractionation confirmed that human tau is highly enriched in insoluble cytosolic and synaptosomal fractions, whereas endogenous mouse tau is virtually absent from synapses. Cytosolic tau was resistant to solubilization with urea and Triton X-100, indicating the formation of larger tau aggregates. By contrast, synaptic tau was partially soluble after Triton X-100 treatment and most likely represents aggregates of smaller size. MS corroborated that synaptosomal tau is nonphosphorylated. Tau enriched in the synapse of line 66 mice, therefore, appears to be in an oligomeric and nonphosphorylated state, and one that could have a direct impact on cognitive function.
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Affiliation(s)
- Nora Lemke
- Charité-Universitätsmedizin Berlin, Berlin, Germany; Bundesanstalt für Materialforschung und-prüfung, Berlin, Germany
| | - Valeria Melis
- School of Medicine, Medical Sciences and Nutrition, University of Aberdeen, Foresterhill, Aberdeen, United Kingdom
| | | | | | - Boris Neumann
- Charité-Universitätsmedizin Berlin, Berlin, Germany; Proteome Factory AG, Berlin, Germany
| | - Charles R Harrington
- School of Medicine, Medical Sciences and Nutrition, University of Aberdeen, Foresterhill, Aberdeen, United Kingdom; TauRx Therapeutics Ltd., Aberdeen, United Kingdom
| | - Gernot Riedel
- School of Medicine, Medical Sciences and Nutrition, University of Aberdeen, Foresterhill, Aberdeen, United Kingdom
| | - Claude M Wischik
- School of Medicine, Medical Sciences and Nutrition, University of Aberdeen, Foresterhill, Aberdeen, United Kingdom; TauRx Therapeutics Ltd., Aberdeen, United Kingdom
| | | | - Karima Schwab
- Charité-Universitätsmedizin Berlin, Berlin, Germany.
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22
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Wu Q, Bai Y, Li W, Congdon EE, Liu W, Lin Y, Ji C, Gan WB, Sigurdsson EM. Increased neuronal activity in motor cortex reveals prominent calcium dyshomeostasis in tauopathy mice. Neurobiol Dis 2020; 147:105165. [PMID: 33166699 DOI: 10.1016/j.nbd.2020.105165] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Revised: 11/01/2020] [Accepted: 11/03/2020] [Indexed: 12/25/2022] Open
Abstract
Perturbed neuronal Ca2+ homeostasis is implicated in Alzheimer's disease, which has primarily been demonstrated in mice with amyloid-β deposits but to a lesser and more variable extent in tauopathy models. In this study, we injected AAV to express Ca2+ indicator in layer II/III motor cortex neurons and measured neuronal Ca2+ activity by two photon imaging in awake transgenic JNPL3 tauopathy and wild-type mice. Various biochemical measurements were conducted in postmortem mouse brains for mechanistic insight and a group of animals received two intravenous injections of a tau monoclonal antibody spaced by four days to test whether the Ca2+ dyshomeostasis was related to pathological tau protein. Under running conditions, we found abnormal neuronal Ca2+ activity in tauopathy mice compared to age-matched wild-type mice with higher frequency of Ca2+ transients, lower amplitude of peak Ca2+ transients and lower total Ca2+ activity in layer II/III motor cortex neurons. While at resting conditions, only Ca2+ frequency was increased. Brain levels of soluble pathological tau correlated better than insoluble tau levels with the degree of Ca2+ dysfunction in tauopathy mice. Furthermore, tau monoclonal antibody 4E6 partially rescued Ca2+ activity abnormalities in tauopathy mice after two intravenous injections and decreased soluble pathological tau protein within the brain. This correlation and antibody effects strongly suggest that the neuronal Ca2+ dyshomeostasis is causally linked to pathological tau protein. These findings also reveal more pronounced neuronal Ca2+ dysregulation in tauopathy mice than previously reported by two-photon imaging that can be partially corrected with an acute tau antibody treatment.
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Affiliation(s)
- Qian Wu
- New York University Grossman School of Medicine, Department of Neuroscience and Physiology, Science Building, 435 East 30th Street, New York, NY 10016, United States of America; New York University Grossman School of Medicine, Neuroscience Institute, Science Building, 435 East 30th Street, New York, NY 10016, United States of America.
| | - Yang Bai
- New York University Grossman School of Medicine, Department of Neuroscience and Physiology, Science Building, 435 East 30th Street, New York, NY 10016, United States of America; New York University Grossman School of Medicine, Neuroscience Institute, Science Building, 435 East 30th Street, New York, NY 10016, United States of America; New York University Grossman School of Medicine, Skirball Institute, 550 First Avenue, New York, NY 10016, United States of America.
| | - Wei Li
- New York University Grossman School of Medicine, Department of Neuroscience and Physiology, Science Building, 435 East 30th Street, New York, NY 10016, United States of America; New York University Grossman School of Medicine, Neuroscience Institute, Science Building, 435 East 30th Street, New York, NY 10016, United States of America; New York University Grossman School of Medicine, Skirball Institute, 550 First Avenue, New York, NY 10016, United States of America
| | - Erin E Congdon
- New York University Grossman School of Medicine, Department of Neuroscience and Physiology, Science Building, 435 East 30th Street, New York, NY 10016, United States of America; New York University Grossman School of Medicine, Neuroscience Institute, Science Building, 435 East 30th Street, New York, NY 10016, United States of America.
| | - Wenke Liu
- New York University Grossman School of Medicine, Department of Psychiatry, 550 First Avenue, New York, NY 10016, United States of America.
| | - Yan Lin
- New York University Grossman School of Medicine, Department of Neuroscience and Physiology, Science Building, 435 East 30th Street, New York, NY 10016, United States of America; New York University Grossman School of Medicine, Neuroscience Institute, Science Building, 435 East 30th Street, New York, NY 10016, United States of America.
| | - Changyi Ji
- New York University Grossman School of Medicine, Department of Neuroscience and Physiology, Science Building, 435 East 30th Street, New York, NY 10016, United States of America; New York University Grossman School of Medicine, Neuroscience Institute, Science Building, 435 East 30th Street, New York, NY 10016, United States of America.
| | - Wen-Biao Gan
- New York University Grossman School of Medicine, Department of Neuroscience and Physiology, Science Building, 435 East 30th Street, New York, NY 10016, United States of America; New York University Grossman School of Medicine, Neuroscience Institute, Science Building, 435 East 30th Street, New York, NY 10016, United States of America; New York University Grossman School of Medicine, Skirball Institute, 550 First Avenue, New York, NY 10016, United States of America.
| | - Einar M Sigurdsson
- New York University Grossman School of Medicine, Department of Neuroscience and Physiology, Science Building, 435 East 30th Street, New York, NY 10016, United States of America; New York University Grossman School of Medicine, Neuroscience Institute, Science Building, 435 East 30th Street, New York, NY 10016, United States of America; Department of Psychiatry, New York University Grossman School of Medicine, New York, NY 10016, United States of America.
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23
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Keramidis I, Vourkou E, Papanikolopoulou K, Skoulakis EMC. Functional Interactions of Tau Phosphorylation Sites That Mediate Toxicity and Deficient Learning in Drosophila melanogaster. Front Mol Neurosci 2020; 13:569520. [PMID: 33192295 PMCID: PMC7609872 DOI: 10.3389/fnmol.2020.569520] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Accepted: 09/15/2020] [Indexed: 01/01/2023] Open
Abstract
Hyperphosphorylated Tau protein is the main component of the neurofibrillary tangles, characterizing degenerating neurons in Alzheimer’s disease and other Tauopathies. Expression of human Tau protein in Drosophila CNS results in increased toxicity, premature mortality and learning and memory deficits. Herein we use novel transgenic lines to investigate the contribution of specific phosphorylation sites previously implicated in Tau toxicity. These three different sites, Ser238, Thr245, and Ser262 were tested either by blocking their phosphorylation, by Ser/Thr to Ala substitution, or pseudophosphorylation, by changing Ser/Thr to Glu. We validate the hypothesis that phosphorylation at Ser262 is necessary for Tau-dependent learning deficits and a “facilitatory gatekeeper” to Ser238 occupation, which is linked to Tau toxicity. Importantly we reveal that phosphorylation at Thr245 acts as a “suppressive gatekeeper”, preventing phosphorylation of many sites including Ser262 and consequently of Ser238. Therefore, we elucidate novel interactions among phosphosites central to Tau mediated neuronal dysfunction and toxicity, likely driven by phosphorylation-dependent conformational plasticity.
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Affiliation(s)
- Iason Keramidis
- Biomedical Sciences Research Centre "Alexander Fleming", Institute for Fundamental Biomedical Research, Vari, Greece
| | - Ergina Vourkou
- Biomedical Sciences Research Centre "Alexander Fleming", Institute for Fundamental Biomedical Research, Vari, Greece.,1st Department of Neurology, Memory and Movement Disorders Clinic, Eginition Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - Katerina Papanikolopoulou
- Biomedical Sciences Research Centre "Alexander Fleming", Institute for Fundamental Biomedical Research, Vari, Greece
| | - Efthimios M C Skoulakis
- Biomedical Sciences Research Centre "Alexander Fleming", Institute for Fundamental Biomedical Research, Vari, Greece
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24
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Brandt R, Trushina NI, Bakota L. Much More Than a Cytoskeletal Protein: Physiological and Pathological Functions of the Non-microtubule Binding Region of Tau. Front Neurol 2020; 11:590059. [PMID: 33193056 PMCID: PMC7604284 DOI: 10.3389/fneur.2020.590059] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Accepted: 09/16/2020] [Indexed: 12/21/2022] Open
Abstract
Tau protein (MAPT) is classified as a microtubule-associated protein (MAP) and is believed to regulate the axonal microtubule arrangement. It belongs to the tau/MAP2/MAP4 family of MAPs that have a similar microtubule binding region at their carboxy-terminal half. In tauopathies, such as Alzheimer's disease, tau is distributed more in the somatodendritic compartment, where it aggregates into filamentous structures, the formation of which correlates with cognitive impairments in patients. While microtubules are the dominant interaction partners of tau under physiological conditions, tau has many additional interaction partners that can contribute to its physiological and pathological role. In particular, the amino-terminal non-microtubule binding domain (N-terminal projection region, NTR) of tau interacts with many partners that are involved in membrane organization. The NTR contains intrinsically disordered regions (IDRs) that show a strong evolutionary increase in the disorder and may have been the basis for the development of new, tau-specific interactions. In this review we discuss the functional organization of the tau protein and the special features of the tau non-microtubule binding region also in the connection with the results of Tau KO models. We consider possible physiological and pathological functions of tau's non-microtubule interactions, which could indicate that interactions mediated by tau's NTR and regulated by far-reaching functional interactions of the PRR and the extreme C-terminus of tau contribute to the pathological processes.
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Affiliation(s)
- Roland Brandt
- Department of Neurobiology, University of Osnabrück, Osnabrück, Germany.,Center for Cellular Nanoanalytics, University of Osnabrück, Osnabrück, Germany.,Institute of Cognitive Science, University of Osnabrück, Osnabrück, Germany
| | | | - Lidia Bakota
- Department of Neurobiology, University of Osnabrück, Osnabrück, Germany
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25
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Siano G, Varisco M, Scarlatti A, Caiazza MC, Dunville K, Cremisi F, Costa M, Pancrazi L, Di Primio C, Cattaneo A. Gene Expression of Disease-related Genes in Alzheimer's Disease is Impaired by Tau Aggregation. J Mol Biol 2020; 432:166675. [PMID: 33058882 DOI: 10.1016/j.jmb.2020.10.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2020] [Revised: 09/24/2020] [Accepted: 10/07/2020] [Indexed: 12/19/2022]
Abstract
Neuronal hyperexcitability linked to an increase in glutamate signalling is a peculiar trait of the early stages of Alzheimer's disease (AD) and tauopathies, however, a progressive reduction in glutamate release follows in advanced stages. We recently reported that in the early phases of the neurodegenerative process, soluble, non-aggregated Tau accumulates in the nucleus and modulates the expression of disease-relevant genes directly involved in glutamatergic transmission, thus establishing a link between Tau instability and altered neurotransmission. Here we report that while the nuclear translocation of Tau in cultured cells is not impaired by its own aggregation, the nuclear amyloid inclusions of aggregated Tau abolish Tau-dependent increased expression of the glutamate transporter. Remarkably, we observed that in the prefrontal cortex (PFC) of AD patient brain, the glutamate transporter is upregulated at early stages and is downregulated at late stages. The Gene Set Enrichment Analysis indicates that the modulation of Tau-dependent gene expression along the disease progression can be extended to all protein pathways of the glutamatergic synapse. Together, this evidence links the altered glutamatergic function in the PFC during AD progression to the newly discovered function of nuclear Tau.
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Affiliation(s)
- G Siano
- Laboratorio di Biologia BIO@SNS, Scuola Normale Superiore, Pisa, Italy
| | - M Varisco
- Laboratorio di Biologia BIO@SNS, Scuola Normale Superiore, Pisa, Italy
| | - A Scarlatti
- Laboratorio di Biologia BIO@SNS, Scuola Normale Superiore, Pisa, Italy
| | - M C Caiazza
- Laboratorio di Biologia BIO@SNS, Scuola Normale Superiore, Pisa, Italy
| | - K Dunville
- Laboratorio di Biologia BIO@SNS, Scuola Normale Superiore, Pisa, Italy
| | - F Cremisi
- Laboratorio di Biologia BIO@SNS, Scuola Normale Superiore, Pisa, Italy
| | - M Costa
- Istituto di Neuroscienze, CNR, Pisa, Italy
| | - L Pancrazi
- Istituto di Neuroscienze, CNR, Pisa, Italy
| | - C Di Primio
- Laboratorio di Biologia BIO@SNS, Scuola Normale Superiore, Pisa, Italy; Istituto di Neuroscienze, CNR, Pisa, Italy.
| | - A Cattaneo
- Laboratorio di Biologia BIO@SNS, Scuola Normale Superiore, Pisa, Italy.
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26
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Tau and Alpha Synuclein Synergistic Effect in Neurodegenerative Diseases: When the Periphery Is the Core. Int J Mol Sci 2020; 21:ijms21145030. [PMID: 32708732 PMCID: PMC7404325 DOI: 10.3390/ijms21145030] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 07/13/2020] [Accepted: 07/14/2020] [Indexed: 02/08/2023] Open
Abstract
In neuronal cells, tau is a microtubule-associated protein placed in axons and alpha synuclein is enriched at presynaptic terminals. They display a propensity to form pathologic aggregates, which are considered the underlying cause of Alzheimer's and Parkinson's diseases. Their functional impairment induces loss of axonal transport, synaptic and mitochondrial disarray, leading to a "dying back" pattern of degeneration, which starts at the periphery of cells. In addition, pathologic spreading of alpha-synuclein from the peripheral nervous system to the brain through anatomical connectivity has been demonstrated for Parkinson's disease. Thus, examination of the extent and types of tau and alpha-synuclein in peripheral tissues and their relation to brain neurodegenerative diseases is of relevance since it may provide insights into patterns of protein aggregation and neurodegeneration. Moreover, peripheral nervous tissues are easily accessible in-vivo and can play a relevant role in the early diagnosis of these conditions. Up-to-date investigations of tau species in peripheral tissues are scant and have mainly been restricted to rodents, whereas, more evidence is available on alpha synuclein in peripheral tissues. Here we aim to review the literature on the functional role of tau and alpha synuclein in physiological conditions and disease at the axonal level, their distribution in peripheral tissues, and discuss possible commonalities/diversities as well as their interaction in proteinopathies.
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27
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Liquid-liquid phase separation induces pathogenic tau conformations in vitro. Nat Commun 2020; 11:2809. [PMID: 32499559 PMCID: PMC7272632 DOI: 10.1038/s41467-020-16580-3] [Citation(s) in RCA: 177] [Impact Index Per Article: 44.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Accepted: 05/08/2020] [Indexed: 01/21/2023] Open
Abstract
Formation of membrane-less organelles via liquid-liquid phase separation is one way cells meet the biological requirement for spatiotemporal regulation of cellular components and reactions. Recently, tau, a protein known for its involvement in Alzheimer’s disease and other tauopathies, was found to undergo liquid–liquid phase separation making it one of several proteins associated with neurodegenerative diseases to do so. Here, we demonstrate that tau forms dynamic liquid droplets in vitro at physiological protein levels upon molecular crowding in buffers that resemble physiological conditions. Tau droplet formation is significantly enhanced by disease-associated modifications, including the AT8 phospho-epitope and the P301L tau mutation linked to an inherited tauopathy. Moreover, tau droplet dynamics are significantly reduced by these modified forms of tau. Extended phase separation promoted a time-dependent adoption of toxic conformations and oligomerization, but not filamentous aggregation. P301L tau protein showed the greatest oligomer formation following extended phase separation. These findings suggest that phase separation of tau may facilitate the formation of non-filamentous pathogenic tau conformations. Tau plays an important role in tauopathies and undergoes liquid-liquid phase separation (LLPS). The authors show that disease-related P301L mutant and phosphomimic (S199E/S202E/T205E) tau enhance LLPS in vitro at physiological levels, and using specific antibodies, that tau LLPS leads to pathological conformations such as N-terminal exposure and oligomeric species.
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28
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Barthet G, Mulle C. Presynaptic failure in Alzheimer's disease. Prog Neurobiol 2020; 194:101801. [PMID: 32428558 DOI: 10.1016/j.pneurobio.2020.101801] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Revised: 03/24/2020] [Accepted: 04/03/2020] [Indexed: 12/14/2022]
Abstract
Synaptic loss is the best correlate of cognitive deficits in Alzheimer's disease (AD). Extensive experimental evidence also indicates alterations of synaptic properties at the early stages of disease progression, before synapse loss and neuronal degeneration. A majority of studies in mouse models of AD have focused on post-synaptic mechanisms, including impairment of long-term plasticity, spine structure and glutamate receptor-mediated transmission. Here we review the literature indicating that the synaptic pathology in AD includes a strong presynaptic component. We describe the evidence indicating presynaptic physiological functions of the major molecular players in AD. These include the amyloid precursor protein (APP) and the two presenilin (PS) paralogs PS1 or PS2, genetically linked to the early-onset form of AD, in addition to tau which accumulates in a pathological form in the AD brain. Three main mechanisms participating in presynaptic functions are highlighted. APP fragments bind to presynaptic receptors (e.g. nAChRs and GABAB receptors), presenilins control Ca2+ homeostasis and Ca2+-sensors, and tau regulates the localization of presynaptic molecules and synaptic vesicles. We then discuss how impairment of these presynaptic physiological functions can explain or forecast the hallmarks of synaptic impairment and associated dysfunction of neuronal circuits in AD. Beyond the physiological roles of the AD-related proteins, studies in AD brains also support preferential presynaptic alteration. This review features presynaptic failure as a strong component of pathological mechanisms in AD.
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Affiliation(s)
- Gael Barthet
- Interdisciplinary Institute for Neuroscience, CNRS UMR 5297, University of Bordeaux, France
| | - Christophe Mulle
- Interdisciplinary Institute for Neuroscience, CNRS UMR 5297, University of Bordeaux, France.
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29
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Regan P, Cho K. The Role of Tau in the Post-synapse. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1184:113-121. [PMID: 32096033 DOI: 10.1007/978-981-32-9358-8_10] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
It is well documented that tauopathy is involved in various forms of neurodegenerative disease. However, there is a huge gap in terms of our understanding of the neurophysiological roles of tau, and how these can be aberrantly regulated by pathological processes. Tau is enriched in the axon but is also localized to synapses. The finding of synaptically localised tau has undoubtedly created more questions than it has answered. What is the physiological role of tau at the synapse? Whether and how does tau interact with and effect other synaptic proteins to mediate this function? Are these effects regulated by post-translational modifications of tau, such as phosphorylation? Such questions require significant attention from the scientific community if we are to resolve this critical aspect of tau biology. This chapter will describe our current understanding of synaptic tau and its functions and illuminate the numerous remaining challenges in this evolving research area.
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Affiliation(s)
- Philip Regan
- Henry Wellcome Laboratories for Integrative Neuroscience and Endocrinology, Bristol Medical School, Faculty of Health Sciences, University of Bristol, Bristol, UK
| | - Kwangwook Cho
- UK-Dementia Research Institute, Department of Basic and Clinical Neuroscience, Maurice Wohl Clinical Neuroscience Institute, King's College London, London, UK.
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30
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Samimi N, Asada A, Ando K. Tau Abnormalities and Autophagic Defects in Neurodegenerative Disorders; A Feed-forward Cycle. Galen Med J 2020; 9:e1681. [PMID: 34466566 PMCID: PMC8343705 DOI: 10.31661/gmj.v9i0.1681] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Revised: 11/11/2019] [Accepted: 11/24/2019] [Indexed: 11/16/2022] Open
Abstract
Abnormal deposition of misfolded proteins is a neuropathological characteristic shared by many neurodegenerative disorders including Alzheimer’s disease (AD). Generation of excessive amounts of aggregated proteins and impairment of degradation systems for misfolded proteins such as autophagy can lead to accumulation of proteins in diseased neurons. Molecules that contribute to both these effects are emerging as critical players in disease pathogenesis. Furthermore, impairment of autophagy under disease conditions can be both a cause and a consequence of abnormal protein accumulation. Specifically, disease-causing proteins can impair autophagy, which further enhances the accumulation of abnormal proteins. In this short review, we focus on the relationship between the microtubule-associated protein tau and autophagy to highlight a feed-forward mechanism in disease pathogenesis.
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Affiliation(s)
- Nastaran Samimi
- Noncommunicable Diseases Research Center, Fasa University of Medical Sciences, Fasa, Iran
- Department of Brain and Cognitive Sciences, Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, ACECR, Tehran, Iran
| | - Akiko Asada
- Department of Biological Sciences, School of Science, Tokyo Metropolitan University, Tokyo, Japan
- Graduate School of Science, Tokyo Metropolitan University, Tokyo, Japan
| | - Kanae Ando
- Department of Biological Sciences, School of Science, Tokyo Metropolitan University, Tokyo, Japan
- Graduate School of Science, Tokyo Metropolitan University, Tokyo, Japan
- Correspondence to: Kanae Ando, Department of Biological Sciences, School of Science, Tokyo Metropolitan University, Tokyo 192- 0397, Japan Telephone Number: +81-42-677-2769 Email Address:
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31
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Amadoro G, Latina V, Corsetti V, Calissano P. N-terminal tau truncation in the pathogenesis of Alzheimer's disease (AD): Developing a novel diagnostic and therapeutic approach. Biochim Biophys Acta Mol Basis Dis 2019; 1866:165584. [PMID: 31676377 DOI: 10.1016/j.bbadis.2019.165584] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Revised: 09/23/2019] [Accepted: 09/24/2019] [Indexed: 01/04/2023]
Abstract
Tau truncation occurs at early stages during the development of human Alzheimer's disease (AD) and other tauopathy dementias. Tau cleavage, particularly in its N-terminal projection domain, is able to drive per se neurodegeneration, regardless of its pro-aggregative pathway(s) and in fragment(s)-dependent way. In this short review, we highlight the pathological relevance of the 20-22 kDa NH2-truncated tau fragment which is endowed with potent neurotoxic "gain-of-function" action(s), both in vitro and in vivo. An extensive comment on its clinical value as novel progression/diagnostic biomarker and potential therapeutic target in the context of tau-mediated neurodegeneration is also provided.
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Affiliation(s)
- G Amadoro
- European Brain Research Institute (EBRI), Viale Regina Elena 295, 00161 Rome, Italy; Institute of Translational Pharmacology (IFT)-CNR, Via Fosso del Cavaliere 100, 00133 Rome, Italy.
| | - V Latina
- European Brain Research Institute (EBRI), Viale Regina Elena 295, 00161 Rome, Italy
| | - V Corsetti
- European Brain Research Institute (EBRI), Viale Regina Elena 295, 00161 Rome, Italy
| | - P Calissano
- European Brain Research Institute (EBRI), Viale Regina Elena 295, 00161 Rome, Italy
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32
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Iwata M, Watanabe S, Yamane A, Miyasaka T, Misonou H. Regulatory mechanisms for the axonal localization of tau protein in neurons. Mol Biol Cell 2019; 30:2441-2457. [PMID: 31364926 PMCID: PMC6743362 DOI: 10.1091/mbc.e19-03-0183] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Tau is a microtubule (MT)-associated protein that is thought to be localized to the axon. However, its precise localization in developing neurons and mechanisms for the axonal localization have not been fully addressed. In this study, we found that the axonal localization of tau in cultured rat hippocampal neurons mainly occur during early neuronal development. Interestingly, transient expression of human tau in very immature neurons, but not in mature neurons, mimicked the developmental localization of endogenous tau to the axon. We therefore were able to establish an experimental model, in which exogenously expressed tau can be properly localized to the axon. Using this model, we obtained a surprising finding that the axonal localization of tau did not require stable MT binding. Tau lacking the MT-binding domain (MTBD) exhibited high diffusivity but localized properly to the axon. In contrast, a dephosphorylation-mimetic mutant of the proline-rich region 2 showed reinforced MT binding and mislocalization. Our results suggest that tight binding to MTs prevents tau from entering the axon and results in mislocalization in the soma and dendrites when expressed in mature neurons. This study therefore provides a novel mechanism independent of MTBD for the axonal localization of tau.
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Affiliation(s)
- Minori Iwata
- Laboratory of Ion Channel Pathophysiology, Graduate School of Brain Science, Doshisha University, Kyotanabe-shi, Kyoto 610-0394, Japan
| | - Shoji Watanabe
- Laboratory of Ion Channel Pathophysiology, Graduate School of Brain Science, Doshisha University, Kyotanabe-shi, Kyoto 610-0394, Japan
| | - Ayaka Yamane
- Laboratory of Ion Channel Pathophysiology, Graduate School of Brain Science, Doshisha University, Kyotanabe-shi, Kyoto 610-0394, Japan
| | - Tomohiro Miyasaka
- Department of Neuropathology, Faculty of Life and Medical Sciences, Doshisha University, Kyotanabe-shi, Kyoto 610-0394, Japan.,Center for Research in Neurodegenerative Diseases, Doshisha University, Kyotanabe-shi, Kyoto 610-0394, Japan
| | - Hiroaki Misonou
- Laboratory of Ion Channel Pathophysiology, Graduate School of Brain Science, Doshisha University, Kyotanabe-shi, Kyoto 610-0394, Japan.,Center for Research in Neurodegenerative Diseases, Doshisha University, Kyotanabe-shi, Kyoto 610-0394, Japan
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33
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Ke YD, Chan G, Stefanoska K, Au C, Bi M, Müller J, Przybyla M, Feiten A, Prikas E, Halliday GM, Piguet O, Kiernan MC, Kassiou M, Hodges JR, Loy CT, Mattick JS, Ittner A, Kril JJ, Sutherland GT, Ittner LM. CNS cell type-specific gene profiling of P301S tau transgenic mice identifies genes dysregulated by progressive tau accumulation. J Biol Chem 2019; 294:14149-14162. [PMID: 31366728 DOI: 10.1074/jbc.ra118.005263] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Revised: 07/24/2019] [Indexed: 12/20/2022] Open
Abstract
The microtubule-associated protein tau undergoes aberrant modification resulting in insoluble brain deposits in various neurodegenerative diseases, including frontotemporal dementia (FTD), progressive supranuclear palsy, and corticobasal degeneration. Tau aggregates can form in different cell types of the central nervous system (CNS) but are most prevalent in neurons. We have previously recapitulated aspects of human FTD in mouse models by overexpressing mutant human tau in CNS neurons, including a P301S tau variant in TAU58/2 mice, characterized by early-onset and progressive behavioral deficits and FTD-like neuropathology. The molecular mechanisms underlying the functional deficits of TAU58/2 mice remain mostly elusive. Here, we employed functional genomics (i.e. RNAseq) to determine differentially expressed genes in young and aged TAU58/2 mice to identify alterations in cellular processes that may contribute to neuropathy. We identified genes in cortical brain samples differentially regulated between young and old TAU58/2 mice relative to nontransgenic littermates and by comparative analysis with a dataset of CNS cell type-specific genes expressed in nontransgenic mice. Most differentially-regulated genes had known or putative roles in neurons and included presynaptic and excitatory genes. Specifically, we observed changes in presynaptic factors, glutamatergic signaling, and protein scaffolding. Moreover, in the aged mice, expression levels of several genes whose expression was annotated to occur in other brain cell types were altered. Immunoblotting and immunostaining of brain samples from the TAU58/2 mice confirmed altered expression and localization of identified and network-linked proteins. Our results have revealed genes dysregulated by progressive tau accumulation in an FTD mouse model.
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Affiliation(s)
- Yazi D Ke
- Dementia Research Centre and Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, New South Wales 2109, Australia
| | - Gabriella Chan
- Dementia Research Centre and Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, New South Wales 2109, Australia
| | - Kristie Stefanoska
- Dementia Research Centre and Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, New South Wales 2109, Australia
| | - Carol Au
- Dementia Research Centre and Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, New South Wales 2109, Australia
| | - Mian Bi
- Dementia Research Centre and Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, New South Wales 2109, Australia
| | - Julius Müller
- The Jenner Institute, University of Oxford, Old Road Campus Research Building, Roosevelt Drive, Oxford OX3 7DQ, United Kingdom
| | - Magdalena Przybyla
- Dementia Research Centre and Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, New South Wales 2109, Australia
| | - Astrid Feiten
- Dementia Research Centre and Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, New South Wales 2109, Australia
| | - Emmanuel Prikas
- Dementia Research Centre and Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, New South Wales 2109, Australia
| | - Glenda M Halliday
- Brain and Mind Centre, University of Sydney, Sydney, New South Wales 2005, Australia
| | - Olivier Piguet
- Brain and Mind Centre, University of Sydney, Sydney, New South Wales 2005, Australia.,School of Psychology, University of Sydney, Sydney, New South Wales 2005, Australia.,ARC Centre of Excellence in Cognition and Its Disorders, University of Sydney, Sydney, New South Wales 2005, Australia
| | - Matthew C Kiernan
- Brain and Mind Centre, University of Sydney, Sydney, New South Wales 2005, Australia.,Institute of Clinical Neurosciences, Royal Prince Alfred Hospital, Sydney, New South Wales 2005, Australia
| | - Michael Kassiou
- School of Chemistry, University of Sydney, Sydney, New South Wales 2005, Australia
| | - John R Hodges
- Brain and Mind Centre, University of Sydney, Sydney, New South Wales 2005, Australia
| | - Clement T Loy
- Garvan Institute of Medical Research, Darlinghurst, New South Wales 2010, Australia.,St. Vincent's Clinical School, Faculty of Medicine, University of New South Wales, New South Wales 2010, Australia.,Sydney School of Public Health, University of Sydney, New South Wales 2006, Australia
| | - John S Mattick
- Garvan Institute of Medical Research, Darlinghurst, New South Wales 2010, Australia.,St. Vincent's Clinical School, Faculty of Medicine, University of New South Wales, New South Wales 2010, Australia
| | - Arne Ittner
- Dementia Research Centre and Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, New South Wales 2109, Australia
| | - Jillian J Kril
- Charles Perkins Centre and Discipline of Pathology, Faculty of Medicine and Health, University of Sydney, Sydney, New South Wales 2005, Australia
| | - Greg T Sutherland
- Charles Perkins Centre and Discipline of Pathology, Faculty of Medicine and Health, University of Sydney, Sydney, New South Wales 2005, Australia
| | - Lars M Ittner
- Dementia Research Centre and Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, New South Wales 2109, Australia
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Ittner A, Ittner LM. Dendritic Tau in Alzheimer's Disease. Neuron 2019; 99:13-27. [PMID: 30001506 DOI: 10.1016/j.neuron.2018.06.003] [Citation(s) in RCA: 159] [Impact Index Per Article: 31.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Revised: 05/07/2018] [Accepted: 06/01/2018] [Indexed: 01/08/2023]
Abstract
The microtubule-associated protein tau and amyloid-β (Aβ) are key players in Alzheimer's disease (AD). Aβ and tau are linked in a molecular pathway at the post-synapse with tau-dependent synaptic dysfunction being a major pathomechanism in AD. Recent work on site-specific modification of dendritic and more specifically post-synaptic tau has revealed new endogenous functions of tau that limits synaptic Aβ toxicity. Thus, molecular studies opened a new perspective on tau, placing it at the center of neurotoxic and neuroprotective signaling at the post-synapse. Here, we review recent advances on tau in the dendritic compartments, with implications for understanding and treatment of AD and related neurological conditions.
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Affiliation(s)
- Arne Ittner
- Dementia Research Unit, School of Medical Sciences, University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Lars M Ittner
- Dementia Research Unit, School of Medical Sciences, University of New South Wales, Sydney, New South Wales 2052, Australia; Neuroscience Research Australia, Sydney, New South Wales 2031, Australia; Dementia Research Centre, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, New South Wales 2109, Australia.
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35
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Green C, Sydow A, Vogel S, Anglada-Huguet M, Wiedermann D, Mandelkow E, Mandelkow EM, Hoehn M. Functional networks are impaired by elevated tau-protein but reversible in a regulatable Alzheimer's disease mouse model. Mol Neurodegener 2019; 14:13. [PMID: 30917861 PMCID: PMC6438042 DOI: 10.1186/s13024-019-0316-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Accepted: 03/15/2019] [Indexed: 12/31/2022] Open
Abstract
Background Aggregation of tau proteins is a distinct hallmark of tauopathies and has been a focus of research and clinical trials for Alzheimer’s Disease. Recent reports have pointed towards a toxic effect of soluble or oligomeric tau in the spreading of tau pathology in Alzheimer’s disease. Here we investigated the effects of expressing human tau repeat domain (tauRD) with pro- or anti-aggregant mutations in regulatable transgenic mouse models of Alzheimer’s Disease on the functional neuronal networks and the structural connectivity strength. Methods Pro-aggregant and anti-aggregant mice were studied when their mutant tauRD was switched on for 12 months to reach the stage where pro-aggregant mice show cognitive impairment, whereas anti-aggregant mice remained cognitively normal. Then, mutant tauRD was switched off by doxycycline treatment for 8 weeks so that soluble transgenic tau disappeared and cognition recovered in the pro-aggregant mice, although some aggregates remained. At these two time points, at baseline after 12 months of mutant tau expression and after 8 weeks of doxycycline treatment, resting state fMRI and diffusion MRI were used to determine functional neuronal networks and fiber connectivities. Results of the transgenic mice were compared with wildtype littermates. Results Functional connectivity was strongly reduced in transgenic animals during mutant tauRD expression, in relation to WT mice. Interestingly, transgenic mice with the non-aggregant tau mutant showed identical functional deficits as the pro-aggregant mice, even though in this case there was no cognitive decline by behavioral testing. Upon 8 weeks doxycycline treatment and transgene switch-off, functional connectivity in both transgenic groups presented complete normalization of functional connectivity strength, equivalent to the situation in WT littermates. Structural connectivity was found only marginally sensitive to mutant tau expression (both pro- and anti-aggregant tauRD) and by doxycycline treatment. Conclusions Our in vivo investigations unravel for the first time a strong reduction of functional neuronal networks by the presence of increased soluble rather than fibrillary tau, independent of its intrinsic propensity of aggregation, which is reversible by switching tau off. Our functional MRI study thus is an unexpected in vivo validation of a novel property of tau, while previous results pointed to a role of aggregation propensity for a pathological state by histopathology and cognitive decline. Our results present further evidence for early tauopathy biomarkers or a potential early stage drug target by functional networks analysis. Electronic supplementary material The online version of this article (10.1186/s13024-019-0316-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Claudia Green
- In-vivo-NMR Laboratory, Max Planck Institute for Metabolism Research, Gleuelerstrasse 50, D-50931, Cologne, Germany
| | - Astrid Sydow
- Max-Planck-Institute for Metabolism Research, Hamburg Outstation, c/o DESY, Notkestrasse 85, 22607, Hamburg, Germany
| | - Stefanie Vogel
- In-vivo-NMR Laboratory, Max Planck Institute for Metabolism Research, Gleuelerstrasse 50, D-50931, Cologne, Germany
| | - Marta Anglada-Huguet
- Max-Planck-Institute for Metabolism Research, Hamburg Outstation, c/o DESY, Notkestrasse 85, 22607, Hamburg, Germany
| | - Dirk Wiedermann
- In-vivo-NMR Laboratory, Max Planck Institute for Metabolism Research, Gleuelerstrasse 50, D-50931, Cologne, Germany
| | - Eckhard Mandelkow
- German Center for Neurodegenerative Diseases (DZNE), Ludwig-Erhard-Allee 2, 53175, Bonn, Germany.,CAESAR Research Center, Ludwig-Erhard-Allee 2, 53175, Bonn, Germany
| | - Eva-Maria Mandelkow
- German Center for Neurodegenerative Diseases (DZNE), Ludwig-Erhard-Allee 2, 53175, Bonn, Germany.,CAESAR Research Center, Ludwig-Erhard-Allee 2, 53175, Bonn, Germany
| | - Mathias Hoehn
- In-vivo-NMR Laboratory, Max Planck Institute for Metabolism Research, Gleuelerstrasse 50, D-50931, Cologne, Germany. .,Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands. .,Percuros B.V., Enschede, The Netherlands.
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36
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Presynaptic Pathophysiology Encoded in Different Domains of Tau - Hyper-Versus Hypoexcitability? ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1184:97-103. [PMID: 32096031 DOI: 10.1007/978-981-32-9358-8_8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Mutations in MAPT (Tau) have been implicated in several types of tauopathy, but the pathways leading to neurodegeneration have remained elusive and are heterogeneous. Here we describe the effects of two mutations, both linked to AD or FTD, that are located in different domains of Tau and show different pathways of toxicity. The deletion mutation ΔK280 lies in the repeat domain and strongly increases β-structure and hence aggregation, whereas the mutation A152T lies in the N-terminal projection domain, has little effect on aggregation but instead on signalling. Both mutations cause presynaptic dysfunction, but in opposite ways, leading to hypoexcitability/hypoactivity vs. hyperexcitability/excitotoxicity, respectively. In organotypic slices these abnormal states can be reversed by drugs, e.g. Tau aggregation inhibitors or modulators of glutamate uptake. This information could contribute to the understanding of "normal" Tau biology and possible therapeutical strategies.
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37
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Castellani RJ, Perry G. Tau Biology, Tauopathy, Traumatic Brain Injury, and Diagnostic Challenges. J Alzheimers Dis 2019; 67:447-467. [PMID: 30584140 PMCID: PMC6398540 DOI: 10.3233/jad-180721] [Citation(s) in RCA: 61] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/08/2018] [Indexed: 12/12/2022]
Abstract
There is considerable interest in the pathobiology of tau protein, given its potential role in neurodegenerative diseases and aging. Tau is an important microtubule associated protein, required for the assembly of tubulin into microtubules and maintaining structural integrity of axons. Tau has other diverse cellular functions involving signal transduction, cellular proliferation, developmental neurobiology, neuroplasticity, and synaptic activity. Alternative splicing results in tau isoforms with differing microtubule binding affinity, differing representation in pathological inclusions in certain disease states, and differing roles in developmental biology and homeostasis. Tau haplotypes confer differing susceptibility to neurodegeneration. Tau phosphorylation is a normal metabolic process, critical in controlling tau's binding to microtubules, and is ongoing within the brain at all times. Tau may be hyperphosphorylated, and may aggregate as detectable fibrillar deposits in tissues, in both aging and neurodegenerative disease. The hypothesis that p-tau is neurotoxic has prompted constructs related to isomers, low-n assembly intermediates or oligomers, and the "tau prion". Human postmortem studies have elucidated broad patterns of tauopathy, with tendencies for those patterns to differ as a function of disease phenotype. However, there is extensive overlap, not only between genuine neurodegenerative diseases, but also between aging and disease. Recent studies highlight uniqueness to pathological patterns, including a pattern attributed to repetitive head trauma, although clinical correlations have been elusive. The diagnostic process for tauopathies and neurodegenerative diseases in general is challenging in many respects, and may be particularly problematic for postmortem evaluation of former athletes and military service members.
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Affiliation(s)
- Rudy J. Castellani
- Departments of Pathology and Neuroscience, West Virginia University School of Medicine, Morgantown, WV, USA
| | - George Perry
- College of Sciences, University of Texas, San Antonio, San Antonio, TX, USA
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38
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Chen Y, Fu AKY, Ip NY. Synaptic dysfunction in Alzheimer's disease: Mechanisms and therapeutic strategies. Pharmacol Ther 2018; 195:186-198. [PMID: 30439458 DOI: 10.1016/j.pharmthera.2018.11.006] [Citation(s) in RCA: 115] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Alzheimer's disease (AD), the most prevalent neurodegenerative disease in the elderly population, is characterized by progressive cognitive decline and pathological hallmarks of amyloid plaques and neurofibrillary tangles. However, its pathophysiological mechanisms are poorly understood, and diagnostic tools and interventions are limited. Here, we review recent research on the amyloid hypothesis and beta-amyloid-induced dysfunction of neuronal synapses through distinct cell surface receptors. We also review how tau protein leads to synaptotoxicity through pathological modification, localization, and propagation. Finally, we discuss experimental therapeutics for AD and propose potential applications of disease-modifying strategies targeting synaptic failure for improved treatment of AD.
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Affiliation(s)
- Yu Chen
- Division of Life Science, State Key Laboratory of Molecular Neuroscience and Molecular Neuroscience Center, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China; The Brain Cognition and Brain Disease Institute, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, Guangdong, China; Guangdong Provincial Key Laboratory of Brain Science, Disease and Drug Development, HKUST Shenzhen Research Institute, Shenzhen, Guangdong, China.
| | - Amy K Y Fu
- Division of Life Science, State Key Laboratory of Molecular Neuroscience and Molecular Neuroscience Center, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China; Guangdong Provincial Key Laboratory of Brain Science, Disease and Drug Development, HKUST Shenzhen Research Institute, Shenzhen, Guangdong, China
| | - Nancy Y Ip
- Division of Life Science, State Key Laboratory of Molecular Neuroscience and Molecular Neuroscience Center, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China; Guangdong Provincial Key Laboratory of Brain Science, Disease and Drug Development, HKUST Shenzhen Research Institute, Shenzhen, Guangdong, China.
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39
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Schverer M, Lanfumey L, Baulieu EE, Froger N, Villey I. Neurosteroids: non-genomic pathways in neuroplasticity and involvement in neurological diseases. Pharmacol Ther 2018; 191:190-206. [PMID: 29953900 DOI: 10.1016/j.pharmthera.2018.06.011] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Neurosteroids are neuroactive brain-born steroids. They can act through non-genomic and/or through genomic pathways. Genomic pathways are largely described for steroid hormones: the binding to nuclear receptors leads to transcription regulation. Pregnenolone, Dehydroepiandrosterone, their respective sulfate esters and Allopregnanolone have no corresponding nuclear receptor identified so far whereas some of their non-genomic targets have been identified. Neuroplasticity is the capacity that neuronal networks have to change their structure and function in response to biological and/or environmental signals; it is regulated by several mechanisms, including those that involve neurosteroids. In this review, after a description of their biosynthesis, the effects of Pregnenolone, Dehydroepiandrosterone, their respective sulfate esters and Allopregnanolone on their targets will be exposed. We then shall highlight that neurosteroids, by acting on these targets, can regulate neurogenesis, structural and functional plasticity. Finally, we will discuss the therapeutic potential of neurosteroids in the pathophysiology of neurological diseases in which alterations of neuroplasticity are associated with changes in neurosteroid levels.
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Affiliation(s)
- Marina Schverer
- Inserm U894, Centre de Psychiatrie et Neurosciences, Université Paris Descartes, 75014 Paris, France
| | - Laurence Lanfumey
- Inserm U894, Centre de Psychiatrie et Neurosciences, Université Paris Descartes, 75014 Paris, France.
| | - Etienne-Emile Baulieu
- MAPREG SAS, Le Kremlin-Bicêtre, France; Inserm UMR 1195, Université Paris-Saclay, Le Kremlin Bicêtre, France
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Asgharzadeh P, Özdemir B, Reski R, Röhrle O, Birkhold AI. Computational 3D imaging to quantify structural components and assembly of protein networks. Acta Biomater 2018; 69:206-217. [PMID: 29378323 DOI: 10.1016/j.actbio.2018.01.020] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Revised: 12/21/2017] [Accepted: 01/16/2018] [Indexed: 12/11/2022]
Abstract
Traditionally, protein structures have been described by the secondary structure architecture and fold arrangement. However, the relatively novel method of 3D confocal microscopy of fluorescent-protein-tagged networks in living cells allows resolving the detailed spatial organization of these networks. This provides new possibilities to predict network functionality, as structure and function seem to be linked at various scales. Here, we propose a quantitative approach using 3D confocal microscopy image data to describe protein networks based on their nano-structural characteristics. This analysis is constructed in four steps: (i) Segmentation of the microscopic raw data into a volume model and extraction of a spatial graph representing the protein network. (ii) Quantifying protein network gross morphology using the volume model. (iii) Quantifying protein network components using the spatial graph. (iv) Linking these two scales to obtain insights into network assembly. Here, we quantitatively describe the filamentous temperature sensitive Z protein network of the moss Physcomitrella patens and elucidate relations between network size and assembly details. Future applications will link network structure and functionality by tracking dynamic structural changes over time and comparing different states or types of networks, possibly allowing more precise identification of (mal) functions or the design of protein-engineered biomaterials for applications in regenerative medicine. STATEMENT OF SIGNIFICANCE Protein networks are highly complex and dynamic structures that play various roles in biological environments. Analyzing the detailed spatial structure of these networks may lead to new insight into biological functions and malfunctions. Here, we propose a tool set that extracts structural information at two scales of the protein network and allows therefore to address questions such as "how is the network built?" or "how networks grow?".
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41
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AD-Related N-Terminal Truncated Tau Is Sufficient to Recapitulate In Vivo the Early Perturbations of Human Neuropathology: Implications for Immunotherapy. Mol Neurobiol 2018; 55:8124-8153. [PMID: 29508283 DOI: 10.1007/s12035-018-0974-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Accepted: 02/19/2018] [Indexed: 01/08/2023]
Abstract
The NH2tau 26-44 aa (i.e., NH2htau) is the minimal biologically active moiety of longer 20-22-kDa NH2-truncated form of human tau-a neurotoxic fragment mapping between 26 and 230 amino acids of full-length protein (htau40)-which is detectable in presynaptic terminals and peripheral CSF from patients suffering from AD and other non-AD neurodegenerative diseases. Nevertheless, whether its exogenous administration in healthy nontransgenic mice is able to elicit a neuropathological phenotype resembling human tauopathies has not been yet investigated. We explored the in vivo effects evoked by subchronic intracerebroventricular (i.c.v.) infusion of NH2htau or its reverse counterpart into two lines of young (2-month-old) wild-type mice (C57BL/6 and B6SJL). Six days after its accumulation into hippocampal parenchyma, significant impairment in memory/learning performance was detected in NH2htau-treated group in association with reduced synaptic connectivity and neuroinflammatory response. Compromised short-term plasticity in paired-pulse facilitation paradigm (PPF) was detected in the CA3/CA1 synapses from NH2htau-impaired animals along with downregulation in calcineurin (CaN)-stimulated pCREB/c-Fos pathway(s). Importantly, these behavioral, synaptotoxic, and neuropathological effects were independent from the genetic background, occurred prior to frank neuronal loss, and were specific because no alterations were detected in the control group infused with its reverse counterpart. Finally, a 2.0-kDa peptide which biochemically and immunologically resembles the injected NH2htau was endogenously detected in vivo, being present in hippocampal synaptosomal preparations from AD subjects. Given that the identification of the neurotoxic tau species is mandatory to develop a more effective tau-based immunological approach, our evidence can have important translational implications for cure of human tauopathies.
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42
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Wang X, Cheng D, Jiang W, Ma Y. Mechanisms Underlying Aluminum Neurotoxicity Related to 14-3-3ζ Protein. Toxicol Sci 2018; 163:45-56. [DOI: 10.1093/toxsci/kfy021] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Affiliation(s)
- Xiaomei Wang
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, People’s Republic of China
| | - Dai Cheng
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, People’s Republic of China
- College of Food Engineering and Biotechnology, Tianjin University of Science and Technology, Tianjin, People’s Republic of China
| | - Weibo Jiang
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, People’s Republic of China
| | - Yuxia Ma
- Department of Nutrition and Hygiene, Hebei Medical University, Shijiazhuang, China
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43
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Pir GJ, Choudhary B, Mandelkow E. Caenorhabditis elegans models of tauopathy. FASEB J 2017; 31:5137-5148. [PMID: 29191965 DOI: 10.1096/fj.201701007] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Accepted: 09/20/2017] [Indexed: 12/14/2022]
Abstract
One of the hallmarks of the tauopathies, which include the neurodegenerative disorders, such as Alzheimer disease (AD), corticobasal degeneration, frontotemporal dementia, and progressive supranuclear palsy (PSP), is the abnormal accumulation of post-translationally modified, insoluble tau. The result is a loss of neurons, decreased mental function, and complete dependence of patients on others. Aggregation of tau, which under physiologic conditions is a highly soluble protein, is thought to be central to the pathogenesis of these diseases. Indeed one of the strongest lines of evidence is the MAPT gene polymorphisms that lead to the familial forms of tauopathy. Extensive research in animal models over the years has contributed some of the most important findings regarding the pathogenesis of these diseases. Despite this, the precise molecular mechanisms that lead to abnormal tau folding, accumulation, and spreading remain unknown. Owing to the fact that most of the biochemical pathways are conserved, Caenorhabditis elegans provides an alternative approach to identify cellular mechanisms and druggable genes that operate in such disorders. Many human genes implicated in neurodegenerative diseases have counterparts in C. elegans, making it an excellent model in which to study their pathogenesis. In this article, we review some of the important findings gained from C. elegans tauopathy models.-Pir, G. J., Choudhary, B., Mandelkow, E. Caenorhabditiselegans models of tauopathy.
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Affiliation(s)
- Ghulam Jeelani Pir
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany; .,Max-Planck-Institute for Metabolism Research-Cologne, Hamburg, Germany
| | - Bikash Choudhary
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany.,Max-Planck-Institute for Metabolism Research-Cologne, Hamburg, Germany
| | - Eckhard Mandelkow
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany.,Max-Planck-Institute for Metabolism Research-Cologne, Hamburg, Germany.,Caesar Research Center, Bonn, Germany
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44
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Kneynsberg A, Combs B, Christensen K, Morfini G, Kanaan NM. Axonal Degeneration in Tauopathies: Disease Relevance and Underlying Mechanisms. Front Neurosci 2017; 11:572. [PMID: 29089864 PMCID: PMC5651019 DOI: 10.3389/fnins.2017.00572] [Citation(s) in RCA: 70] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Accepted: 09/29/2017] [Indexed: 12/14/2022] Open
Abstract
Tauopathies are a diverse group of diseases featuring progressive dying-back neurodegeneration of specific neuronal populations in association with accumulation of abnormal forms of the microtubule-associated protein tau. It is well-established that the clinical symptoms characteristic of tauopathies correlate with deficits in synaptic function and neuritic connectivity early in the course of disease, but mechanisms underlying these critical pathogenic events are not fully understood. Biochemical in vitro evidence fueled the widespread notion that microtubule stabilization represents tau's primary biological role and that the marked atrophy of neurites observed in tauopathies results from loss of microtubule stability. However, this notion contrasts with the mild phenotype associated with tau deletion. Instead, an analysis of cellular hallmarks common to different tauopathies, including aberrant patterns of protein phosphorylation and early degeneration of axons, suggests that alterations in kinase-based signaling pathways and deficits in axonal transport (AT) associated with such alterations contribute to the loss of neuronal connectivity triggered by pathogenic forms of tau. Here, we review a body of literature providing evidence that axonal pathology represents an early and common pathogenic event among human tauopathies. Observations of axonal degeneration in animal models of specific tauopathies are discussed and similarities to human disease highlighted. Finally, we discuss potential mechanistic pathways other than microtubule destabilization by which disease-related forms of tau may promote axonopathy.
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Affiliation(s)
- Andrew Kneynsberg
- Neuroscience Program, Michigan State University, East Lansing, MI, United States.,Department of Translational Science and Molecular Medicine, College of Human Medicine, Michigan State University, Grand Rapids, MI, United States
| | - Benjamin Combs
- Department of Translational Science and Molecular Medicine, College of Human Medicine, Michigan State University, Grand Rapids, MI, United States
| | - Kyle Christensen
- Neuroscience Program, Michigan State University, East Lansing, MI, United States.,Department of Translational Science and Molecular Medicine, College of Human Medicine, Michigan State University, Grand Rapids, MI, United States
| | - Gerardo Morfini
- Department of Anatomy and Cell Biology, University of Illinois at Chicago, Chicago, IL, United States
| | - Nicholas M Kanaan
- Neuroscience Program, Michigan State University, East Lansing, MI, United States.,Department of Translational Science and Molecular Medicine, College of Human Medicine, Michigan State University, Grand Rapids, MI, United States.,Hauenstein Neuroscience Center, Mercy Health Saint Mary's, Grand Rapids, MI, United States
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45
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Florenzano F, Veronica C, Ciasca G, Ciotti MT, Pittaluga A, Olivero G, Feligioni M, Iannuzzi F, Latina V, Maria Sciacca MF, Sinopoli A, Milardi D, Pappalardo G, Marco DS, Papi M, Atlante A, Bobba A, Borreca A, Calissano P, Amadoro G. Extracellular truncated tau causes early presynaptic dysfunction associated with Alzheimer's disease and other tauopathies. Oncotarget 2017; 8:64745-64778. [PMID: 29029390 PMCID: PMC5630290 DOI: 10.18632/oncotarget.17371] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2017] [Accepted: 04/11/2017] [Indexed: 12/14/2022] Open
Abstract
The largest part of tau secreted from AD nerve terminals and released in cerebral spinal fluid (CSF) is C-terminally truncated, soluble and unaggregated supporting potential extracellular role(s) of NH2 -derived fragments of protein on synaptic dysfunction underlying neurodegenerative tauopathies, including Alzheimer's disease (AD). Here we show that sub-toxic doses of extracellular-applied human NH2 tau 26-44 (aka NH 2 htau) -which is the minimal active moiety of neurotoxic 20-22kDa peptide accumulating in vivo at AD synapses and secreted into parenchyma- acutely provokes presynaptic deficit in K+ -evoked glutamate release on hippocampal synaptosomes along with alteration in local Ca2+ dynamics. Neuritic dystrophy, microtubules breakdown, deregulation in presynaptic proteins and loss of mitochondria located at nerve endings are detected in hippocampal cultures only after prolonged exposure to NH 2 htau. The specificity of these biological effects is supported by the lack of any significant change, either on neuronal activity or on cellular integrity, shown by administration of its reverse sequence counterpart which behaves as an inactive control, likely due to a poor conformational flexibility which makes it unable to dynamically perturb biomembrane-like environments. Our results demonstrate that one of the AD-relevant, soluble and secreted N-terminally truncated tau forms can early contribute to pathology outside of neurons causing alterations in synaptic activity at presynaptic level, independently of overt neurodegeneration.
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Affiliation(s)
| | | | - Gabriele Ciasca
- Institute of Physics, Catholic University of the Sacred Heart, Largo F Vito 1, Rome, Italy
| | - Maria Teresa Ciotti
- Institute of Cellular Biology and Neuroscience, CNR, IRCSS Santa Lucia Foundation, Rome, Italy
| | - Anna Pittaluga
- Department of Pharmacy, Pharmacology and Toxicology Section, University of Genoa, Genoa, Viale Cembrano, Italy
| | - Gunedalina Olivero
- Department of Pharmacy, Pharmacology and Toxicology Section, University of Genoa, Genoa, Viale Cembrano, Italy
| | - Marco Feligioni
- European Brain Research Institute, Rome, Italy
- Department of Neurorehabilitation Sciences, Casa Cura Policlinico, Milan, Italy
| | | | | | | | | | - Danilo Milardi
- Institute of Biostructures and Bioimaging, CNR, Catania, Italy
| | | | - De Spirito Marco
- Institute of Physics, Catholic University of the Sacred Heart, Largo F Vito 1, Rome, Italy
| | - Massimiliano Papi
- Institute of Physics, Catholic University of the Sacred Heart, Largo F Vito 1, Rome, Italy
| | - Anna Atlante
- Institute of Biomembranes and Bioenergetics, CNR, Bari, Italy
- Center of Excellence for Biomedical Research, University of Genoa, Genoa, Viale Benedetto XV, Italy
| | - Antonella Bobba
- Institute of Biomembranes and Bioenergetics, CNR, Bari, Italy
- Center of Excellence for Biomedical Research, University of Genoa, Genoa, Viale Benedetto XV, Italy
| | - Antonella Borreca
- Institute of Cellular Biology and Neuroscience, CNR, IRCSS Santa Lucia Foundation, Rome, Italy
| | | | - Giuseppina Amadoro
- European Brain Research Institute, Rome, Italy
- Institute of Translational Pharmacology, CNR, Rome, Italy
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46
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Pawlowski M, Meuth SG, Duning T. Cerebrospinal Fluid Biomarkers in Alzheimer's Disease-From Brain Starch to Bench and Bedside. Diagnostics (Basel) 2017; 7:diagnostics7030042. [PMID: 28703785 PMCID: PMC5617942 DOI: 10.3390/diagnostics7030042] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2017] [Revised: 06/21/2017] [Accepted: 07/06/2017] [Indexed: 12/13/2022] Open
Abstract
Alzheimer’s disease is the most common cause of dementia. Over the last three decades, research has advanced dramatically and provided a detailed understanding of the molecular events underlying the pathogenesis of Alzheimer’s disease. In parallel, assays for the detection of biomarkers that reflect the typical Alzheimer’s disease-associated pathology have been developed and validated in myriads of clinical studies. Such biomarkers complement clinical diagnosis and improve diagnostic accuracy. The use of biomarkers will become even more important with the advent of disease-modifying therapies. Such therapies will likely be most beneficial when administered early in the disease course. Here, we summarise the development of the core Alzheimer’s disease cerebrospinal fluid biomarkers: amyloid-β and tau. We provide an overview of their role in cellular physiology and Alzheimer’s disease pathology, and embed their development as cerebrospinal fluid biomarkers into the historical context of Alzheimer’s disease research. Finally, we summarise recommendations for their use in clinical practice, and outline perspectives for novel cerebrospinal fluid candidate biomarkers.
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Affiliation(s)
- Matthias Pawlowski
- Department of Neurology, University Hospital Münster, Albert-Schweitzer-Campus 1, Building A1, Münster 48149, Germany.
| | - Sven G Meuth
- Department of Neurology, University Hospital Münster, Albert-Schweitzer-Campus 1, Building A1, Münster 48149, Germany.
| | - Thomas Duning
- Department of Neurology, University Hospital Münster, Albert-Schweitzer-Campus 1, Building A1, Münster 48149, Germany.
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Kaniyappan S, Chandupatla RR, Mandelkow EM, Mandelkow E. Extracellular low-n oligomers of tau cause selective synaptotoxicity without affecting cell viability. Alzheimers Dement 2017; 13:1270-1291. [PMID: 28528849 DOI: 10.1016/j.jalz.2017.04.002] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Revised: 03/27/2017] [Accepted: 04/11/2017] [Indexed: 12/30/2022]
Abstract
INTRODUCTION Tau-mediated toxicity in Alzheimer's disease is thought to operate through low-n oligomers, rather than filamentous aggregates. However, the nature of oligomers and pathways of toxicity are poorly understood. Therefore, we investigated structural and functional aspects of highly purified oligomers of a pro-aggregant tau species. METHODS Purified oligomers of the tau repeat domain were characterized by biophysical and structural methods. Functional aspects were investigated by cellular assays ((3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay of cell viability, lactate dehydrogenase release assay [for cell toxicity], reactive oxygen species production, and calcium assay), combined with analysis of neuronal dendritic spines exposed to oligomers. RESULTS Purified low-n oligomers are roughly globular, with sizes around 1.6 to 5.4 nm, exhibit an altered conformation, but do not have substantial β-structure. Treatment of primary neurons with oligomers impairs spine morphology and density, accompanied by increased reactive oxygen species and intracellular calcium, but without affecting cell viability (by (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay of cell viability and lactate dehydrogenase release assay [for cell toxicity]). DISCUSSION Tau oligomers are toxic to synapses but not lethal to cells.
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Affiliation(s)
- Senthilvelrajan Kaniyappan
- DZNE, German Center for Neurodegenerative Diseases, Bonn, Germany; MPI for Metabolism Research, Hamburg, Germany.
| | - Ram Reddy Chandupatla
- DZNE, German Center for Neurodegenerative Diseases, Bonn, Germany; MPI for Metabolism Research, Hamburg, Germany
| | - Eva-Maria Mandelkow
- DZNE, German Center for Neurodegenerative Diseases, Bonn, Germany; MPI for Metabolism Research, Hamburg, Germany; CAESAR Research Center, Bonn, Germany
| | - Eckhard Mandelkow
- DZNE, German Center for Neurodegenerative Diseases, Bonn, Germany; MPI for Metabolism Research, Hamburg, Germany; CAESAR Research Center, Bonn, Germany.
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48
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Zhou L, McInnes J, Wierda K, Holt M, Herrmann AG, Jackson RJ, Wang YC, Swerts J, Beyens J, Miskiewicz K, Vilain S, Dewachter I, Moechars D, De Strooper B, Spires-Jones TL, De Wit J, Verstreken P. Tau association with synaptic vesicles causes presynaptic dysfunction. Nat Commun 2017; 8:15295. [PMID: 28492240 PMCID: PMC5437271 DOI: 10.1038/ncomms15295] [Citation(s) in RCA: 238] [Impact Index Per Article: 34.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Accepted: 03/17/2017] [Indexed: 12/18/2022] Open
Abstract
Tau is implicated in more than 20 neurodegenerative diseases, including Alzheimer's disease. Under pathological conditions, Tau dissociates from axonal microtubules and missorts to pre- and postsynaptic terminals. Patients suffer from early synaptic dysfunction prior to Tau aggregate formation, but the underlying mechanism is unclear. Here we show that pathogenic Tau binds to synaptic vesicles via its N-terminal domain and interferes with presynaptic functions, including synaptic vesicle mobility and release rate, lowering neurotransmission in fly and rat neurons. Pathological Tau mutants lacking the vesicle binding domain still localize to the presynaptic compartment but do not impair synaptic function in fly neurons. Moreover, an exogenously applied membrane-permeable peptide that competes for Tau-vesicle binding suppresses Tau-induced synaptic toxicity in rat neurons. Our work uncovers a presynaptic role of Tau that may be part of the early pathology in various Tauopathies and could be exploited therapeutically.
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Affiliation(s)
- Lujia Zhou
- VIB-KU Leuven Center for Brain & Disease Research, Leuven 3000, Belgium
- KU Leuven, Department of Neurosciences, Leuven Research Institute for Neuroscience and Disease (LIND), Leuven 3000, Belgium
| | - Joseph McInnes
- VIB-KU Leuven Center for Brain & Disease Research, Leuven 3000, Belgium
- KU Leuven, Department of Neurosciences, Leuven Research Institute for Neuroscience and Disease (LIND), Leuven 3000, Belgium
| | - Keimpe Wierda
- VIB-KU Leuven Center for Brain & Disease Research, Leuven 3000, Belgium
- KU Leuven, Department of Neurosciences, Leuven Research Institute for Neuroscience and Disease (LIND), Leuven 3000, Belgium
| | - Matthew Holt
- VIB-KU Leuven Center for Brain & Disease Research, Leuven 3000, Belgium
- KU Leuven, Department of Neurosciences, Leuven Research Institute for Neuroscience and Disease (LIND), Leuven 3000, Belgium
| | - Abigail G. Herrmann
- University of Edinburgh, Centre for Cognitive and Neural Systems, Center for Dementia Prevention and Euan MacDonald Centre, Edinburgh EH8 9JZ, UK
| | - Rosemary J. Jackson
- University of Edinburgh, Centre for Cognitive and Neural Systems, Center for Dementia Prevention and Euan MacDonald Centre, Edinburgh EH8 9JZ, UK
| | - Yu-Chun Wang
- VIB-KU Leuven Center for Brain & Disease Research, Leuven 3000, Belgium
- KU Leuven, Department of Neurosciences, Leuven Research Institute for Neuroscience and Disease (LIND), Leuven 3000, Belgium
| | - Jef Swerts
- VIB-KU Leuven Center for Brain & Disease Research, Leuven 3000, Belgium
- KU Leuven, Department of Neurosciences, Leuven Research Institute for Neuroscience and Disease (LIND), Leuven 3000, Belgium
| | - Jelle Beyens
- VIB-KU Leuven Center for Brain & Disease Research, Leuven 3000, Belgium
- KU Leuven, Department of Neurosciences, Leuven Research Institute for Neuroscience and Disease (LIND), Leuven 3000, Belgium
| | - Katarzyna Miskiewicz
- VIB-KU Leuven Center for Brain & Disease Research, Leuven 3000, Belgium
- KU Leuven, Department of Neurosciences, Leuven Research Institute for Neuroscience and Disease (LIND), Leuven 3000, Belgium
| | - Sven Vilain
- VIB-KU Leuven Center for Brain & Disease Research, Leuven 3000, Belgium
- KU Leuven, Department of Neurosciences, Leuven Research Institute for Neuroscience and Disease (LIND), Leuven 3000, Belgium
| | - Ilse Dewachter
- Catholic University of Louvain, Alzheimer Dementia Group, Institute of Neuroscience, Brussels 1200, Belgium
- University of Hasselt, Biomedical Research Institute, Hasselt 3500, Belgium
| | - Diederik Moechars
- A Division of Janssen Pharmaceutica NV, Neuroscience Department, Janssen Research and Development, Beerse 2340, Belgium
| | - Bart De Strooper
- VIB-KU Leuven Center for Brain & Disease Research, Leuven 3000, Belgium
- KU Leuven, Department of Neurosciences, Leuven Research Institute for Neuroscience and Disease (LIND), Leuven 3000, Belgium
| | - Tara L. Spires-Jones
- University of Edinburgh, Centre for Cognitive and Neural Systems, Center for Dementia Prevention and Euan MacDonald Centre, Edinburgh EH8 9JZ, UK
| | - Joris De Wit
- VIB-KU Leuven Center for Brain & Disease Research, Leuven 3000, Belgium
- KU Leuven, Department of Neurosciences, Leuven Research Institute for Neuroscience and Disease (LIND), Leuven 3000, Belgium
| | - Patrik Verstreken
- VIB-KU Leuven Center for Brain & Disease Research, Leuven 3000, Belgium
- KU Leuven, Department of Neurosciences, Leuven Research Institute for Neuroscience and Disease (LIND), Leuven 3000, Belgium
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49
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Forner S, Baglietto-Vargas D, Martini AC, Trujillo-Estrada L, LaFerla FM. Synaptic Impairment in Alzheimer's Disease: A Dysregulated Symphony. Trends Neurosci 2017; 40:347-357. [PMID: 28494972 DOI: 10.1016/j.tins.2017.04.002] [Citation(s) in RCA: 286] [Impact Index Per Article: 40.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2017] [Revised: 04/13/2017] [Accepted: 04/14/2017] [Indexed: 11/30/2022]
Abstract
Alzheimer's disease (AD) is characterized by memory loss, cognitive decline, and devastating neurodegeneration, not only as a result of the extracellular accumulation of beta-amyloid peptide (Aβ) and intracellular accumulation of tau, but also as a consequence of the dysfunction and loss of synapses. Although significant advances have been made in our understanding of the relationship of the pathological role of Aβ and tau in synapse dysfunction, several questions remain as to how Aβ and tau interdependently cause impairments in synaptic function in AD. Overall, more insight into these questions should enable researchers in this field to develop novel therapeutic targets to mitigate or delay the cognitive deficits associated with this devastating disease.
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Affiliation(s)
- Stefania Forner
- Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, CA 92697, USA
| | - David Baglietto-Vargas
- Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, CA 92697, USA
| | - Alessandra C Martini
- Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, CA 92697, USA
| | - Laura Trujillo-Estrada
- Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, CA 92697, USA
| | - Frank M LaFerla
- Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, CA 92697, USA; Department of Neurobiology and Behavior, University of California, Irvine, CA 92697, USA.
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50
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Fontaine SN, Ingram A, Cloyd RA, Meier SE, Miller E, Lyons D, Nation GK, Mechas E, Weiss B, Lanzillotta C, Di Domenico F, Schmitt F, Powell DK, Vandsburger M, Abisambra JF. Identification of changes in neuronal function as a consequence of aging and tauopathic neurodegeneration using a novel and sensitive magnetic resonance imaging approach. Neurobiol Aging 2017; 56:78-86. [PMID: 28500878 DOI: 10.1016/j.neurobiolaging.2017.04.007] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Revised: 03/09/2017] [Accepted: 04/09/2017] [Indexed: 12/20/2022]
Abstract
Tauopathies, the most common of which is Alzheimer's disease (AD), constitute the most crippling neurodegenerative threat to our aging population. Tauopathic patients have significant cognitive decline accompanied by irreversible and severe brain atrophy, and it is thought that neuronal dysfunction begins years before diagnosis. Our current understanding of tauopathies has yielded promising therapeutic interventions but have all failed in clinical trials. This is partly due to the inability to identify and intervene in an effective therapeutic window early in the disease process. A major challenge that contributes to the definition of an early therapeutic window is limited technologies. To address these challenges, we modified and adapted a manganese-enhanced magnetic resonance imaging (MEMRI) approach to provide sensitive and quantitative power to detect changes in broad neuronal function in aging mice. Considering that tau tangle burden correlates well with cognitive impairment in Alzheimer's patients, we performed our MEMRI approach in a time course of aging mice and an accelerated mouse model of tauopathy. We measured significant changes in broad neuronal function as a consequence of age, and in transgenic mice, before the deposition of bona fide tangles. This MEMRI approach represents the first diagnostic measure of neuronal dysfunction in mice. Successful translation of this technology in the clinic could serve as a sensitive diagnostic tool for the definition of effective therapeutic windows.
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Affiliation(s)
- Sarah N Fontaine
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA; Epilepsy Center, University of Kentucky, Lexington, KY, USA
| | - Alexandria Ingram
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA
| | - Ryan A Cloyd
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA
| | - Shelby E Meier
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA; Department of Physiology, College of Medicine, University of Kentucky, Lexington, KY, USA
| | - Emily Miller
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA
| | - Danielle Lyons
- Spinal Cord Injury and Brain Injury Research Center, University of Kentucky, Lexington, KY, USA
| | - Grant K Nation
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA
| | - Elizabeth Mechas
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA
| | - Blaine Weiss
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA
| | - Chiara Lanzillotta
- Department of Biochemical Sciences, Sapienza University of Rome, Rome, Italy
| | - Fabio Di Domenico
- Department of Biochemical Sciences, Sapienza University of Rome, Rome, Italy
| | - Frederick Schmitt
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA
| | - David K Powell
- Department of Biomedical Engineering, University of Kentucky, Lexington, KY, USA
| | - Moriel Vandsburger
- Department of Physiology, College of Medicine, University of Kentucky, Lexington, KY, USA; Department of Biomedical Engineering, University of Kentucky, Lexington, KY, USA
| | - Jose F Abisambra
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA; Epilepsy Center, University of Kentucky, Lexington, KY, USA; Department of Physiology, College of Medicine, University of Kentucky, Lexington, KY, USA; Spinal Cord Injury and Brain Injury Research Center, University of Kentucky, Lexington, KY, USA.
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