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Harris SS, Ellingford R, Hartmann J, Dasgupta D, Kehring M, Rajani RM, Graykowski D, Quittot N, Sivasankaran D, Commins C, Fan Z, Bond SA, Wolf F, Dupret D, Dolan RJ, Konnerth A, Neef A, Hyman BT, Busche MA. Alzheimer's disease patient-derived high-molecular-weight tau impairs bursting in hippocampal neurons. Cell 2025:S0092-8674(25)00408-8. [PMID: 40300603 DOI: 10.1016/j.cell.2025.04.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2024] [Revised: 02/21/2025] [Accepted: 04/03/2025] [Indexed: 05/01/2025]
Abstract
Tau accumulation is closely related to cognitive symptoms in Alzheimer's disease (AD). However, the cellular drivers of tau-dependent decline of memory-based cognition remain elusive. Here, we employed in vivo Neuropixels and patch-clamp recordings in mouse models and demonstrate that tau, independent of β-amyloid, selectively debilitates complex-spike burst firing of CA1 hippocampal neurons, a fundamental cellular mechanism underpinning learning and memory. Impaired bursting was associated with altered hippocampal network activities that are coupled to burst firing patterns (i.e., theta rhythms and high-frequency ripples) and was concurrent with reduced neuronal expression of CaV2.3 calcium channels, which are essential for burst firing in vivo. We subsequently identify soluble high molecular weight (HMW) tau, isolated from human AD brain, as the tau species responsible for suppression of burst firing. These data provide a cellular mechanism for tau-dependent cognitive decline in AD and implicate a rare species of intracellular HMW tau as a therapeutic target.
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Affiliation(s)
- Samuel S Harris
- UK Dementia Research Institute at University College London, London, UK.
| | - Robert Ellingford
- UK Dementia Research Institute at University College London, London, UK
| | - Jana Hartmann
- UK Dementia Research Institute at University College London, London, UK
| | - Debanjan Dasgupta
- UK Dementia Research Institute at University College London, London, UK
| | - Marten Kehring
- UK Dementia Research Institute at University College London, London, UK
| | - Rikesh M Rajani
- UK Dementia Research Institute at University College London, London, UK; British Heart Foundation - UK Dementia Research Institute Centre for Vascular Dementia Research at The University of Edinburgh, Edinburgh, UK
| | - David Graykowski
- UK Dementia Research Institute at University College London, London, UK
| | - Noé Quittot
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Dhanush Sivasankaran
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Caitlin Commins
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Zhanyun Fan
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Suraya A Bond
- UK Dementia Research Institute at University College London, London, UK
| | - Fred Wolf
- Göttingen Campus Institute for Dynamics of Biological Networks, Göttingen, Germany
| | - David Dupret
- Medical Research Council Brain Network Dynamics Unit, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Raymond J Dolan
- Max Planck UCL Centre for Computational Psychiatry and Ageing Research, London, UK
| | - Arthur Konnerth
- Institute of Neuroscience, Technical University of Munich, Munich, Germany; Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Andreas Neef
- Göttingen Campus Institute for Dynamics of Biological Networks, Göttingen, Germany
| | - Bradley T Hyman
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Marc Aurel Busche
- UK Dementia Research Institute at University College London, London, UK; Department of Neurodegenerative Diseases, University Hospital of Geriatric Medicine FELIX PLATTER and University of Basel, Basel, Switzerland; Department of Biomedicine, University of Basel, Basel, Switzerland.
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Wan L, Zhong P, Li P, Ren Y, Wang W, Yu M, Feng HY, Yan Z. CRISPR-based epigenetic editing of Gad1 improves synaptic inhibition and cognitive behavior in a Tauopathy mouse model. Neurobiol Dis 2025; 206:106826. [PMID: 39894446 DOI: 10.1016/j.nbd.2025.106826] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2024] [Revised: 01/30/2025] [Accepted: 01/30/2025] [Indexed: 02/04/2025] Open
Abstract
GABAergic signaling in the brain plays a key role in regulating synaptic transmission, neuronal excitability, and cognitive processes. Large-scale sequencing has revealed the diminished expression of GABA-related genes in Alzheimer's disease (AD), however, it is largely unclear about the epigenetic mechanisms that dysregulate the transcription of these genes in AD. We confirmed that GABA synthesizing enzymes, GAD1 and GAD2, were significantly downregulated in prefrontal cortex (PFC) of AD human postmortem tissues. A tauopathy mouse model also had the significantly reduced expression of GABA-related genes, as well as the diminished GABAergic synaptic transmission in PFC pyramidal neurons. To elevate endogenous Gad1 levels, we used the CRISPR/Cas9-based epigenome editing technology to recruit histone acetyltransferase p300 to Gad1. Cells transfected with a fusion protein consisting of the nuclease-null dCas9 protein and the catalytic core of p300 (dCas9p300), as well as a guide RNA targeting Gad1 promoter (gRNAGad1), had significantly increased Gad1 mRNA expression and histone acetylation at Gad1 promoter. Furthermore, the tauopathy mouse model with PFC injection of dCas9p300 and gRNAGad1 lentiviruses had significantly elevated GABAergic synaptic currents and improved spatial memory. These results have provided an epigenetic editing-based gene-targeting strategy to restore synaptic inhibition and cognitive function in AD and related disorders.
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Affiliation(s)
- Lei Wan
- Department of Physiology and Biophysics, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY 14214, USA
| | - Ping Zhong
- Department of Physiology and Biophysics, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY 14214, USA
| | - Pei Li
- Department of Physiology and Biophysics, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY 14214, USA
| | - Yong Ren
- Department of Physiology and Biophysics, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY 14214, USA
| | - Wei Wang
- Department of Physiology and Biophysics, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY 14214, USA
| | - Mingjun Yu
- Department of Physiology and Biophysics, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY 14214, USA
| | - Henry Y Feng
- Department of Physiology and Biophysics, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY 14214, USA
| | - Zhen Yan
- Department of Physiology and Biophysics, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY 14214, USA.
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Zhang X, Zhang Y, Zhang T, Wang J, Liu C, Shang Q, Wei X, Zhu H, Shen H, Sun B. HCN2 deficiency correlates with memory deficits and hyperexcitability of dCA1 pyramidal neurons in Alzheimer's disease. Alzheimers Res Ther 2025; 17:55. [PMID: 40016780 PMCID: PMC11866685 DOI: 10.1186/s13195-025-01704-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2024] [Accepted: 02/19/2025] [Indexed: 03/01/2025]
Abstract
BACKGROUND Abnormal excitability of hippocampal neurons may lead to dysfunction of neural circuits and then causes cognitive impairments in Alzheimer's disease (AD). However, the underlying mechanisms remain to be fully elucidated. METHODS Electrophysiology was performed to examine the intrinsic excitability of CA1 neurons and the activity of the hyperpolarization-activated cyclic nucleotide-gated ion channels (HCNs) of CA1 neurons in wild type (WT) and hAPP-J20 mice. The activity of CA1 pyramidal neurons (PNs) was modulated with chemogenetics. The activity of HCNs was regulated with nonselective facilitator (cAMP) or inhibitor (ZD7288) of HCNs. Immunohistochemical staining or western blotting were performed to examine the expression of HCN1 and HCN2 in the hippocampus of WT and hAPP-J20 mice, or AD patients and non-AD controls. AAVs were injected to specifically modulate the expression of HCN2 in dorsal CA1 (dCA1) PNs. Cognitive performance of mice was assessed with behavioral tests. RESULTS dCA1 PNs were more excitable in hAPP-J20 mice, but the excitability of PNs in the ventral CA1 (vCA1) or PV neurons was comparable between WT and hAPP-J20 mice. The activity of the HCNs was reduced in dCA1 PNs of hAPP-J20 mice, and pharmacologically increasing the activity of HCNs attenuated the hyperexcitability of dCA1 PNs in hAPP-J20 mice, suggesting that the reduced activity of HCNs is associated with the hyperexcitability of dCA1 PNs in hAPP-J20 mice. The expression of HCN2 but not HCN1 was reduced in the hippocampus of hAPP-J20 mice, and the expression of HCN2 was also reduced in the hippocampus of AD patients, suggesting that dysregulation of HCN2 is associated with the reduced activity of HCNs in AD. Overexpressing HCN2 rescued the activity of HCNs, attenuated the hyperexcitability of dCA1 PNs and improved memory of hAPP-J20 mice, and knocking down HCN2 impaired the function of HCNs, increased the excitability of dCA1 PNs and led to memory deficits in WT mice. CONCLUSIONS Our data suggest that dysregulation of HCNs, particularly HCN2, contributes to the abnormal excitability of CA1 PNs in AD mice and probably in AD patients as well, and thus provide new insights into the mechanisms underlying the aberrant activity or excitability of hippocampal neurons in AD.
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Affiliation(s)
- Xiaoqin Zhang
- Department of Pharmacology, Health Science Center of Ningbo University, Ningbo, Zhejiang Province, 315211, China.
| | - Yiping Zhang
- Department of Anesthesiology of the Children's Hospital and School of Brain Science and Brain Medicine, Zhejiang University School of Medicine and National Clinical Research Center for Child Health; NHC and CAMS Key Laboratory of Medical Neurobiology, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, Zhejiang Province, 310058, China
| | - Ting Zhang
- Department of Pharmacology, Health Science Center of Ningbo University, Ningbo, Zhejiang Province, 315211, China
| | - Jing Wang
- Department of Anesthesiology of the Children's Hospital and School of Brain Science and Brain Medicine, Zhejiang University School of Medicine and National Clinical Research Center for Child Health; NHC and CAMS Key Laboratory of Medical Neurobiology, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, Zhejiang Province, 310058, China
| | - Chang Liu
- Department of Pharmacology, Health Science Center of Ningbo University, Ningbo, Zhejiang Province, 315211, China
| | - Qing Shang
- Department of Neurology, The First Affiliated Hospital of Ningbo University, 59 Liuting Street, Haishu District, Ningbo, Zhejiang Province, 315211, China
| | - Xiaojie Wei
- Department of Anesthesiology of the Children's Hospital and School of Brain Science and Brain Medicine, Zhejiang University School of Medicine and National Clinical Research Center for Child Health; NHC and CAMS Key Laboratory of Medical Neurobiology, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, Zhejiang Province, 310058, China
| | - Huaqiang Zhu
- Zhejiang Pharmaceutical College, Ningbo, Zhejiang Province, 315100, China
| | - Haowei Shen
- Department of Pharmacology, Health Science Center of Ningbo University, Ningbo, Zhejiang Province, 315211, China.
| | - Binggui Sun
- Department of Anesthesiology of the Children's Hospital and School of Brain Science and Brain Medicine, Zhejiang University School of Medicine and National Clinical Research Center for Child Health; NHC and CAMS Key Laboratory of Medical Neurobiology, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, Zhejiang Province, 310058, China.
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Wei X, Sun B. CK2-dependent SK channel dysfunction as contributor to neuronal hyperexcitability in Alzheimer's disease. Trends Neurosci 2025; 48:98-99. [PMID: 39757072 DOI: 10.1016/j.tins.2024.12.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2024] [Accepted: 12/18/2024] [Indexed: 01/07/2025]
Abstract
Neuronal hyperexcitability in the cortex and hippocampus represents an early event in Alzheimer's disease (AD). In a recent study, Blankenship and colleagues reported that in a mouse of AD, ventral tegmental area (VTA) dopamine neurons are also hyperexcitable, and this hyperexcitability is due to casein kinase 2 (CK2)-dependent SK channel dysfunction, adding new insights into the underlying mechanisms of aberrant neuronal properties in AD.
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Affiliation(s)
- Xiaojie Wei
- Department of Anesthesiology of the Children's Hospital and School of Brain Science and Brain Medicine, Zhejiang University School of Medicine and National Clinical Research Center for Child Health, Zhejiang University, Hangzhou, Zhejiang Province 310058, China; Institute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou, Zhejiang Province 310020, China
| | - Binggui Sun
- Department of Anesthesiology of the Children's Hospital and School of Brain Science and Brain Medicine, Zhejiang University School of Medicine and National Clinical Research Center for Child Health, Zhejiang University, Hangzhou, Zhejiang Province 310058, China; NHC and CAMS Key Laboratory of Medical Neurobiology, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, Zhejiang Province 310058, China.
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5
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van Nifterick AM, de Haan W, Stam CJ, Hillebrand A, Scheltens P, van Kesteren RE, Gouw AA. Functional network disruption in cognitively unimpaired autosomal dominant Alzheimer's disease: a magnetoencephalography study. Brain Commun 2024; 6:fcae423. [PMID: 39713236 PMCID: PMC11660908 DOI: 10.1093/braincomms/fcae423] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2024] [Revised: 10/09/2024] [Accepted: 11/22/2024] [Indexed: 12/24/2024] Open
Abstract
Understanding the nature and onset of neurophysiological changes, and the selective vulnerability of central hub regions in the functional network, may aid in managing the growing impact of Alzheimer's disease on society. However, the precise neurophysiological alterations occurring in the pre-clinical stage of human Alzheimer's disease remain controversial. This study aims to provide increased insights on quantitative neurophysiological alterations during a true early stage of Alzheimer's disease. Using high spatial resolution source-reconstructed magnetoencephalography, we investigated regional and whole-brain neurophysiological changes in a unique cohort of 11 cognitively unimpaired individuals with pathogenic mutations in the presenilin-1 or amyloid precursor protein gene and a 1:3 matched control group (n = 33) with a median age of 49 years. We examined several quantitative magnetoencephalography measures that have been shown robust in detecting differences in sporadic Alzheimer's disease patients and are sensitive to excitation-inhibition imbalance. This includes spectral power and functional connectivity in different frequency bands. We also investigated hub vulnerability using the hub disruption index. To understand how magnetoencephalography measures change as the disease progresses through its pre-clinical stage, correlations between magnetoencephalography outcomes and various clinical variables like age were analysed. A comparison of spectral power between mutation carriers and controls revealed oscillatory slowing, characterized by widespread higher theta (4-8 Hz) power, a lower posterior peak frequency and lower occipital alpha 2 (10-13 Hz) power. Functional connectivity analyses presented a lower whole-brain (amplitude-based) functional connectivity in the alpha (8-13 Hz) and beta (13-30 Hz) bands, predominantly located in parieto-temporal hub regions. Furthermore, we found a significant hub disruption index for (phase-based) functional connectivity in the theta band, attributed to both higher functional connectivity in 'non-hub' regions alongside a hub disruption. Neurophysiological changes did not correlate with indicators of pre-clinical disease progression in mutation carriers after multiple comparisons correction. Our findings provide evidence that oscillatory slowing and functional connectivity differences occur before cognitive impairment in individuals with autosomal dominant mutations leading to early onset Alzheimer's disease. The nature and direction of these alterations are comparable to those observed in the clinical stages of Alzheimer's disease, suggest an early excitation-inhibition imbalance, and fit with the activity-dependent functional degeneration hypothesis. These insights may prove useful for early diagnosis and intervention in the future.
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Affiliation(s)
- Anne M van Nifterick
- Alzheimer Center Amsterdam, Neurology, Vrije Universiteit Amsterdam, Amsterdam UMC Location VUmc, 1081 HZ Amsterdam, The Netherlands
- Clinical Neurophysiology and MEG Center, Neurology, Amsterdam UMC Location VUmc, 1081 HV Amsterdam, The Netherlands
- Amsterdam Neuroscience, Neurodegeneration, 1081 HV Amsterdam, The Netherlands
| | - Willem de Haan
- Alzheimer Center Amsterdam, Neurology, Vrije Universiteit Amsterdam, Amsterdam UMC Location VUmc, 1081 HZ Amsterdam, The Netherlands
- Amsterdam Neuroscience, Neurodegeneration, 1081 HV Amsterdam, The Netherlands
| | - Cornelis J Stam
- Clinical Neurophysiology and MEG Center, Neurology, Amsterdam UMC Location VUmc, 1081 HV Amsterdam, The Netherlands
- Amsterdam Neuroscience, Neurodegeneration, 1081 HV Amsterdam, The Netherlands
| | - Arjan Hillebrand
- Clinical Neurophysiology and MEG Center, Neurology, Amsterdam UMC Location VUmc, 1081 HV Amsterdam, The Netherlands
- Amsterdam Neuroscience, Brain Imaging, 1081 HV Amsterdam, The Netherlands
- Amsterdam Neuroscience, Systems and Network Neurosciences, 1081 HV Amsterdam, The Netherlands
| | - Philip Scheltens
- Alzheimer Center Amsterdam, Neurology, Vrije Universiteit Amsterdam, Amsterdam UMC Location VUmc, 1081 HZ Amsterdam, The Netherlands
- Amsterdam Neuroscience, Neurodegeneration, 1081 HV Amsterdam, The Netherlands
| | - Ronald E van Kesteren
- Amsterdam Neuroscience, Neurodegeneration, 1081 HV Amsterdam, The Netherlands
- Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Vrije Universiteit Amsterdam, 1081 HV Amsterdam, The Netherlands
| | - Alida A Gouw
- Alzheimer Center Amsterdam, Neurology, Vrije Universiteit Amsterdam, Amsterdam UMC Location VUmc, 1081 HZ Amsterdam, The Netherlands
- Clinical Neurophysiology and MEG Center, Neurology, Amsterdam UMC Location VUmc, 1081 HV Amsterdam, The Netherlands
- Amsterdam Neuroscience, Neurodegeneration, 1081 HV Amsterdam, The Netherlands
- Amsterdam Neuroscience, Systems and Network Neurosciences, 1081 HV Amsterdam, The Netherlands
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6
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Ji C, Yang X, Eleish M, Jiang Y, Tetlow AM, Song SC, 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. Alzheimers Dement 2024; 20:7954-7970. [PMID: 39368113 PMCID: PMC11567809 DOI: 10.1002/alz.14273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2024] [Revised: 08/27/2024] [Accepted: 08/28/2024] [Indexed: 10/07/2024]
Abstract
INTRODUCTION It is unclear how early neuronal deficits occur in tauopathies, if these are associated with changes in neuronal network activity, and if they can be alleviated with therapies. METHODS To address this, we performed in vivo two-photon Ca2+ imaging in tauopathy mice at 6 versus 12 months, compared to controls, and treated the younger animals with a tau antibody. RESULTS Neuronal function was impaired at 6 months but did not deteriorate further at 12 months, presumably because cortical tau burden was comparable at these ages. At 6 months, neurons were mostly hypoactive, with enhanced neuronal synchrony, and had dysregulated responses to stimulus. Ex vivo, electrophysiology revealed altered synaptic transmission and enhanced excitability of motor cortical neurons, which likely explains the altered network activity. Acute tau antibody treatment reduced pathological tau and gliosis and partially restored neuronal function. DISCUSSION Tauopathies are associated with early neuronal deficits that can be attenuated with tau antibody therapy. HIGHLIGHTS Neuronal hypofunction in awake and behaving mice in early stages of tauopathy. Altered network activity disrupted local circuitry engagement in tauopathy mice. Enhanced neuronal excitability and altered synaptic transmission in tauopathy mice. Tau antibody acutely reduced soluble phospho-tau and improved neuronal function.
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Affiliation(s)
- Changyi Ji
- Department of Neuroscience and PhysiologyNeuroscience Institute, New York University Grossman School of MedicineNew YorkUSA
| | - Xiaofeng Yang
- Department of Neuroscience and PhysiologyNeuroscience Institute, New York University Grossman School of MedicineNew YorkUSA
| | - Mohamed Eleish
- Department of Neuroscience and PhysiologyNeuroscience Institute, New York University Grossman School of MedicineNew YorkUSA
| | - Yixiang Jiang
- Department of Neuroscience and PhysiologyNeuroscience Institute, New York University Grossman School of MedicineNew YorkUSA
| | - Amber M. Tetlow
- Department of Neuroscience and PhysiologyNeuroscience Institute, New York University Grossman School of MedicineNew YorkUSA
| | - Soomin C. Song
- Department of PathologyNew York University Grossman School of MedicineNew YorkUSA
- IonLabNew York University Grossman School of MedicineNew YorkUSA
| | - Alejandro Martín‐Ávila
- Department of Neuroscience and PhysiologyNeuroscience Institute, New York University Grossman School of MedicineNew YorkUSA
| | - Qian Wu
- Department of Neuroscience and PhysiologyNeuroscience Institute, New York University Grossman School of MedicineNew YorkUSA
| | - Yanmei Zhou
- Skirball InstituteNew York University Grossman School of MedicineNew YorkUSA
| | - Wenbiao Gan
- Skirball InstituteNew York University Grossman School of MedicineNew YorkUSA
| | - Yan Lin
- Department of Neuroscience and PhysiologyNeuroscience Institute, New York University Grossman School of MedicineNew YorkUSA
| | - Einar M. Sigurdsson
- Department of Neuroscience and PhysiologyNeuroscience Institute, New York University Grossman School of MedicineNew YorkUSA
- Department of PsychiatryNew York University Grossman School of MedicineNew YorkUSA
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7
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Parra Bravo C, Naguib SA, Gan L. Cellular and pathological functions of tau. Nat Rev Mol Cell Biol 2024; 25:845-864. [PMID: 39014245 DOI: 10.1038/s41580-024-00753-9] [Citation(s) in RCA: 36] [Impact Index Per Article: 36.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/10/2024] [Indexed: 07/18/2024]
Abstract
Tau protein is involved in various cellular processes, including having a canonical role in binding and stabilization of microtubules in neurons. Tauopathies are neurodegenerative diseases marked by the abnormal accumulation of tau protein aggregates in neurons, as seen, for example, in conditions such as frontotemporal dementia and Alzheimer disease. Mutations in tau coding regions or that disrupt tau mRNA splicing, tau post-translational modifications and cellular stress factors (such as oxidative stress and inflammation) increase the tendency of tau to aggregate and interfere with its clearance. Pathological tau is strongly implicated in the progression of neurodegenerative diseases, and the propagation of tau aggregates is associated with disease severity. Recent technological advancements, including cryo-electron microscopy and disease models derived from human induced pluripotent stem cells, have increased our understanding of tau-related pathology in neurodegenerative conditions. Substantial progress has been made in deciphering tau aggregate structures and the molecular mechanisms that underlie protein aggregation and toxicity. In this Review, we discuss recent insights into the diverse cellular functions of tau and the pathology of tau inclusions and explore the potential for therapeutic interventions.
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Affiliation(s)
- Celeste Parra Bravo
- Helen and Robert Appel Alzheimer's Disease Research Institute, Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA
- Neuroscience Graduate Program, Weill Cornell Graduate School of Medical Sciences, New York, NY, USA
| | - Sarah A Naguib
- Helen and Robert Appel Alzheimer's Disease Research Institute, Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA
| | - Li Gan
- Helen and Robert Appel Alzheimer's Disease Research Institute, Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA.
- Neuroscience Graduate Program, Weill Cornell Graduate School of Medical Sciences, New York, NY, USA.
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Maksour S, Finol-Urdaneta RK, Hulme AJ, Cabral-da-Silva MEC, Targa Dias Anastacio H, Balez R, Berg T, Turner C, Sanz Muñoz S, Engel M, Kalajdzic P, Lisowski L, Sidhu K, Sachdev PS, Dottori M, Ooi L. Alzheimer's disease induced neurons bearing PSEN1 mutations exhibit reduced excitability. Front Cell Neurosci 2024; 18:1406970. [PMID: 39444394 PMCID: PMC11497635 DOI: 10.3389/fncel.2024.1406970] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2024] [Accepted: 09/23/2024] [Indexed: 10/25/2024] Open
Abstract
Alzheimer's disease (AD) is a devastating neurodegenerative condition that affects memory and cognition, characterized by neuronal loss and currently lacking a cure. Mutations in PSEN1 (Presenilin 1) are among the most common causes of early-onset familial AD (fAD). While changes in neuronal excitability are believed to be early indicators of AD progression, the link between PSEN1 mutations and neuronal excitability remains to be fully elucidated. This study examined iPSC-derived neurons (iNs) from fAD patients with PSEN1 mutations S290C or A246E, alongside CRISPR-corrected isogenic cell lines, to investigate early changes in excitability. Electrophysiological profiling revealed reduced excitability in both PSEN1 mutant iNs compared to their isogenic controls. Neurons bearing S290C and A246E mutations exhibited divergent passive membrane properties compared to isogenic controls, suggesting distinct effects of PSEN1 mutations on neuronal excitability. Additionally, both PSEN1 backgrounds exhibited higher current density of voltage-gated potassium (Kv) channels relative to their isogenic iNs, while displaying comparable voltage-gated sodium (Nav) channel current density. This suggests that the Nav/Kv imbalance contributes to impaired neuronal firing in fAD iNs. Deciphering these early cellular and molecular changes in AD is crucial for understanding disease pathogenesis.
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Affiliation(s)
- Simon Maksour
- School of Chemistry and Molecular Bioscience and Molecular Horizons, University of Wollongong, Wollongong, NSW, Australia
| | - Rocio K. Finol-Urdaneta
- School of Medical and Indigenous Health Science and Molecular Horizons, University of Wollongong, Wollongong, NSW, Australia
| | - Amy J. Hulme
- School of Medical and Indigenous Health Science and Molecular Horizons, University of Wollongong, Wollongong, NSW, Australia
| | | | - Helena Targa Dias Anastacio
- School of Chemistry and Molecular Bioscience and Molecular Horizons, University of Wollongong, Wollongong, NSW, Australia
| | - Rachelle Balez
- School of Chemistry and Molecular Bioscience and Molecular Horizons, University of Wollongong, Wollongong, NSW, Australia
| | - Tracey Berg
- School of Chemistry and Molecular Bioscience and Molecular Horizons, University of Wollongong, Wollongong, NSW, Australia
| | - Calista Turner
- School of Chemistry and Molecular Bioscience and Molecular Horizons, University of Wollongong, Wollongong, NSW, Australia
| | - Sonia Sanz Muñoz
- School of Chemistry and Molecular Bioscience and Molecular Horizons, University of Wollongong, Wollongong, NSW, Australia
| | - Martin Engel
- School of Chemistry and Molecular Bioscience and Molecular Horizons, University of Wollongong, Wollongong, NSW, Australia
| | - Predrag Kalajdzic
- Translational Vectorology Research Unit, Children’s Medical Research Institute, Faculty of Medicine and Health, The University of Sydney, Westmead, NSW, Australia
| | - Leszek Lisowski
- Translational Vectorology Research Unit, Children’s Medical Research Institute, Faculty of Medicine and Health, The University of Sydney, Westmead, NSW, Australia
- Australian Genome Therapeutics Centre, Children’s Medical Research Institute and Sydney Children’s Hospitals Network, Westmead, NSW, Australia
- Laboratory of Molecular Oncology and Innovative Therapies, Military Institute of Medicine – National Research Institute, Warsaw, Poland
| | - Kuldip Sidhu
- Centre for Healthy Brain Ageing, School of Clinical Medicine, University of New South Wales, Sydney, NSW, Australia
| | - Perminder S. Sachdev
- Centre for Healthy Brain Ageing, School of Clinical Medicine, University of New South Wales, Sydney, NSW, Australia
| | - Mirella Dottori
- School of Medical and Indigenous Health Science and Molecular Horizons, University of Wollongong, Wollongong, NSW, Australia
| | - Lezanne Ooi
- School of Chemistry and Molecular Bioscience and Molecular Horizons, University of Wollongong, Wollongong, NSW, Australia
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Alava BR, Morris AR, Liu AC, Abisambra JF, Esser KA. AAV8-P301L tau expression confers age-related disruptions in sleep quantity and timing. NPJ BIOLOGICAL TIMING AND SLEEP 2024; 1:8. [PMID: 39363957 PMCID: PMC11445076 DOI: 10.1038/s44323-024-00009-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/21/2024] [Accepted: 08/08/2024] [Indexed: 10/05/2024]
Abstract
Sleep timing and quantity disturbances persist in tauopathy patients. This has been studied in transgenic models of primary tau neuropathology using traditional electroencephalograms (EEGs) and more recently, the PiezoSleep Mouse Behavioral Tracking System. Here, we generated a primary tauopathy model using an intracerebroventricular injection of human mutant hSyn-P301L-tau, using adeno-associated virus of serotype 8 (AAV8). We discovered distinctions in sleep architecture with altered quantity and timing in AAV8-P301L tau expressing mice of both sexes using the noninvasive PiezoSleep System. The AAV8-P301L tau mice exhibit striking age-related increases in sleep duration specifically at the active phase onset, suggesting a critical and sensitive time-of-day for tauopathy related sleep disturbances to occur. Since our findings show sleep behavior changes at specific transitional periods of the day, tau neuropathology may impact normal diurnal variation in biological processes, which should be explored using the AAV8-P301L tauopathy model.
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Affiliation(s)
- Bryan R. Alava
- Department of Physiology and Aging, University of Florida, Gainesville, FL USA
- Center for Translational Research in Neurodegenerative Disease (CTRND), University of Florida, Gainesville, FL USA
| | - Andrew R. Morris
- Department of Physiology and Aging, University of Florida, Gainesville, FL USA
| | - Andrew C. Liu
- Department of Physiology and Aging, University of Florida, Gainesville, FL USA
| | - Jose F. Abisambra
- Center for Translational Research in Neurodegenerative Disease (CTRND), University of Florida, Gainesville, FL USA
- Department of Neuroscience, University of Florida, Gainesville, FL USA
- Brain Injury Rehabilitation and Neuroresilience (BRAIN) Center, University of Florida, Gainesville, FL USA
| | - Karyn A. Esser
- Department of Physiology and Aging, University of Florida, Gainesville, FL USA
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10
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Yoshioka M, Takahashi M, Kershaw J, Handa M, Takada A, Takuwa H. Two-photon optogenetics-based assessment of neuronal connectivity in healthy and chronic hypoperfusion mice. NEUROPHOTONICS 2024; 11:035009. [PMID: 39345733 PMCID: PMC11436461 DOI: 10.1117/1.nph.11.3.035009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/06/2024] [Revised: 08/16/2024] [Accepted: 08/22/2024] [Indexed: 10/01/2024]
Abstract
Significance Two-photon optogenetics and simultaneous calcium imaging can be used to visualize the response of surrounding neurons with respect to the activity of an optically stimulated target neuron, providing a direct method to assess neuronal connectivity. Aim We aim to develop a two-photon optogenetics-based method for evaluating neuronal connectivity, compare it to the existing indirect resting-state synchrony method, and investigate the application of the method to brain pathophysiology. Approach C1V1-mScarlet was introduced into GCaMP6s-expressing transgenic mice with an adeno-associated virus. Optical stimulation of a single target neuron and simultaneous calcium imaging of the target and surrounding cells were performed. Neuronal connectivity was evaluated from the correlation between the fluorescence intensity of the target and surrounding cells. Results The neuronal connectivity in the living brain was evaluated using two-photon optogenetics. However, resting-state synchrony was not always consistent with two-photon optogenetics-based connectivity. Comparison with neuronal synchrony measured during sensory stimulation suggested that the disagreement was due to external sensory input. Two-photon optogenetics-based connectivity significantly decreased in the common carotid artery occlusion model, whereas there was no significant change in the control group. Conclusions We successfully developed a direct method to evaluate neuronal connectivity in the living brain using two-photon optogenetics. The technique was successful in detecting connectivity impairment in hypoperfusion model mice.
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Affiliation(s)
- Masaki Yoshioka
- National Institutes for Quantum Science and Technology, Institute for Quantum Life Science, Quantum Neuromapping and Neuromodulation Team, Chiba, Japan
- Chiba University, Graduate School of Medicine, Department of Neurological Surgery, Chiba, Japan
| | - Manami Takahashi
- National Institutes for Quantum Science and Technology, Institute for Quantum Life Science, Quantum Neuromapping and Neuromodulation Team, Chiba, Japan
| | - Jeff Kershaw
- National Institutes for Quantum Science and Technology, Institute for Quantum Medical Science, Department of Molecular Imaging and Theranostics, Chiba, Japan
| | - Mariko Handa
- National Institutes for Quantum Science and Technology, Institute for Quantum Life Science, Quantum Neuromapping and Neuromodulation Team, Chiba, Japan
- Chiba University, Graduate School of Science, Department of Quantum Life Science, Chiba, Japan
| | - Ayaka Takada
- National Institutes for Quantum Science and Technology, Institute for Quantum Life Science, Quantum Neuromapping and Neuromodulation Team, Chiba, Japan
- Chiba University, Graduate School of Science, Department of Quantum Life Science, Chiba, Japan
| | - Hiroyuki Takuwa
- National Institutes for Quantum Science and Technology, Institute for Quantum Life Science, Quantum Neuromapping and Neuromodulation Team, Chiba, Japan
- Chiba University, Graduate School of Science, Department of Quantum Life Science, Chiba, Japan
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11
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Linsley JW, Reisine T, Finkbeiner S. Three dimensional and four dimensional live imaging to study mechanisms of progressive neurodegeneration. J Biol Chem 2024; 300:107433. [PMID: 38825007 PMCID: PMC11261153 DOI: 10.1016/j.jbc.2024.107433] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 05/20/2024] [Accepted: 05/26/2024] [Indexed: 06/04/2024] Open
Abstract
Neurodegenerative diseases are complex and progressive, posing challenges to their study and understanding. Recent advances in microscopy imaging technologies have enabled the exploration of neurons in three spatial dimensions (3D) over time (4D). When applied to 3D cultures, tissues, or animals, these technologies can provide valuable insights into the dynamic and spatial nature of neurodegenerative diseases. This review focuses on the use of imaging techniques and neurodegenerative disease models to study neurodegeneration in 4D. Imaging techniques such as confocal microscopy, two-photon microscopy, miniscope imaging, light sheet microscopy, and robotic microscopy offer powerful tools to visualize and analyze neuronal changes over time in 3D tissue. Application of these technologies to in vitro models of neurodegeneration such as mouse organotypic culture systems and human organoid models provide versatile platforms to study neurodegeneration in a physiologically relevant context. Additionally, use of 4D imaging in vivo, including in mouse and zebrafish models of neurodegenerative diseases, allows for the investigation of early dysfunction and behavioral changes associated with neurodegeneration. We propose that these studies have the power to overcome the limitations of two-dimensional monolayer neuronal cultures and pave the way for improved understanding of the dynamics of neurodegenerative diseases and the development of effective therapeutic strategies.
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Affiliation(s)
- Jeremy W Linsley
- Center for Systems and Therapeutics, Gladstone Institutes, San Francisco, California, USA; Operant Biopharma, San Francisco, California, USA
| | - Terry Reisine
- Independent Scientific Consultant, Santa Cruz, California, USA
| | - Steven Finkbeiner
- Center for Systems and Therapeutics, Gladstone Institutes, San Francisco, California, USA; Operant Biopharma, San Francisco, California, USA; Taube/Koret Center for Neurodegenerative Disease, Gladstone Institutes, San Francisco, California, USA; Departments of Neurology and Physiology, University of California, San Francisco, California, USA; Neuroscience Graduate Program, University of California, San Francisco, California, USA; Biomedical Sciences Graduate Program, University of California, San Francisco, California, USA.
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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] [Grants] [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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Chen L, Christenson Wick Z, Vetere LM, Vaughan N, Jurkowski A, Galas A, Diego KS, Philipsberg PA, Soler I, Feng Y, Cai DJ, Shuman T. Progressive Excitability Changes in the Medial Entorhinal Cortex in the 3xTg Mouse Model of Alzheimer's Disease Pathology. J Neurosci 2023; 43:7441-7454. [PMID: 37714705 PMCID: PMC10621765 DOI: 10.1523/jneurosci.1204-23.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Revised: 09/07/2023] [Accepted: 09/08/2023] [Indexed: 09/17/2023] Open
Abstract
Alzheimer's disease (AD) is a chronic neurodegenerative disorder characterized by memory loss and progressive cognitive impairments. In mouse models of AD pathology, studies have found neuronal and synaptic deficits in hippocampus, but less is known about changes in medial entorhinal cortex (MEC), which is the primary spatial input to the hippocampus and an early site of AD pathology. Here, we measured neuronal intrinsic excitability and synaptic activity in MEC layer II (MECII) stellate cells, MECII pyramidal cells, and MEC layer III (MECIII) excitatory neurons at 3 and 10 months of age in the 3xTg mouse model of AD pathology, using male and female mice. At 3 months of age, before the onset of memory impairments, we found early hyperexcitability in intrinsic properties of MECII stellate and pyramidal cells, but this was balanced by a relative reduction in synaptic excitation (E) compared with inhibition (I; E/I ratio), suggesting intact homeostatic mechanisms regulating MECII activity. Conversely, MECIII neurons had reduced intrinsic excitability at this early time point with no change in synaptic E/I ratio. By 10 months of age, after the onset of memory deficits, neuronal excitability of MECII pyramidal cells and MECIII excitatory neurons was largely normalized in 3xTg mice. However, MECII stellate cells remained hyperexcitable, and this was further exacerbated by an increased synaptic E/I ratio. This observed combination of increased intrinsic and synaptic hyperexcitability suggests a breakdown in homeostatic mechanisms specifically in MECII stellate cells at this postsymptomatic time point, which may contribute to the emergence of memory deficits in AD.SIGNIFICANCE STATEMENT AD causes cognitive deficits, but the specific neural circuits that are damaged to drive changes in memory remain unknown. Using a mouse model of AD pathology that expresses both amyloid and tau transgenes, we found that neurons in the MEC have altered excitability. Before the onset of memory impairments, neurons in layer 2 of MEC had increased intrinsic excitability, but this was balanced by reduced inputs onto the cell. However, after the onset of memory impairments, stellate cells in MEC became further hyperexcitable, with increased excitability exacerbated by increased synaptic inputs. Thus, it appears that MEC stellate cells are uniquely disrupted during the progression of memory deficits and may contribute to cognitive deficits in AD.
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Affiliation(s)
- Lingxuan Chen
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, New York 10029
- Department of Physiology and Biophysics, University of California, Irvine, Irvine, California 92697
| | - Zoé Christenson Wick
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, New York 10029
| | - Lauren M Vetere
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, New York 10029
| | - Nick Vaughan
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, New York 10029
| | - Albert Jurkowski
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, New York 10029
- Hunter College, City University of New York, New York, New York 10065
| | - Angelina Galas
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, New York 10029
- New York University, New York, New York 10012
| | - Keziah S Diego
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, New York 10029
| | - Paul A Philipsberg
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, New York 10029
| | - Ivan Soler
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, New York 10029
| | - Yu Feng
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, New York 10029
| | - Denise J Cai
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, New York 10029
| | - Tristan Shuman
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, New York 10029
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14
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van Heusden FC, van Nifterick AM, Souza BC, França ASC, Nauta IM, Stam CJ, Scheltens P, Smit AB, Gouw AA, van Kesteren RE. Neurophysiological alterations in mice and humans carrying mutations in APP and PSEN1 genes. Alzheimers Res Ther 2023; 15:142. [PMID: 37608393 PMCID: PMC10464047 DOI: 10.1186/s13195-023-01287-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Accepted: 08/11/2023] [Indexed: 08/24/2023]
Abstract
BACKGROUND Studies in animal models of Alzheimer's disease (AD) have provided valuable insights into the molecular and cellular processes underlying neuronal network dysfunction. Whether and how AD-related neurophysiological alterations translate between mice and humans remains however uncertain. METHODS We characterized neurophysiological alterations in mice and humans carrying AD mutations in the APP and/or PSEN1 genes, focusing on early pre-symptomatic changes. Longitudinal local field potential recordings were performed in APP/PS1 mice and cross-sectional magnetoencephalography recordings in human APP and/or PSEN1 mutation carriers. All recordings were acquired in the left frontal cortex, parietal cortex, and hippocampus. Spectral power and functional connectivity were analyzed and compared with wildtype control mice and healthy age-matched human subjects. RESULTS APP/PS1 mice showed increased absolute power, especially at higher frequencies (beta and gamma) and predominantly between 3 and 6 moa. Relative power showed an overall shift from lower to higher frequencies over almost the entire recording period and across all three brain regions. Human mutation carriers, on the other hand, did not show changes in power except for an increase in relative theta power in the hippocampus. Mouse parietal cortex and hippocampal power spectra showed a characteristic peak at around 8 Hz which was not significantly altered in transgenic mice. Human power spectra showed a characteristic peak at around 9 Hz, the frequency of which was significantly reduced in mutation carriers. Significant alterations in functional connectivity were detected in theta, alpha, beta, and gamma frequency bands, but the exact frequency range and direction of change differed for APP/PS1 mice and human mutation carriers. CONCLUSIONS Both mice and humans carrying APP and/or PSEN1 mutations show abnormal neurophysiological activity, but several measures do not translate one-to-one between species. Alterations in absolute and relative power in mice should be interpreted with care and may be due to overexpression of amyloid in combination with the absence of tau pathology and cholinergic degeneration. Future studies should explore whether changes in brain activity in other AD mouse models, for instance, those also including tau pathology, provide better translation to the human AD continuum.
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Affiliation(s)
- Fran C van Heusden
- Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Vrije Universiteit Amsterdam, Amsterdam, 1081HV, The Netherlands
| | - Anne M van Nifterick
- Alzheimer Center Amsterdam, Neurology, Vrije Universiteit Amsterdam, Amsterdam UMC Location VUmc, Amsterdam, 1081HV, The Netherlands
- Clinical Neurophysiology and MEG Center, Neurology, Vrije Universiteit Amsterdam, Amsterdam UMC Location VUmc, Amsterdam, 1081HV, The Netherlands
| | - Bryan C Souza
- Donders Institute for Brain, Cognition and Behavior, Radboud University, Nijmegen, 6525AJ, The Netherlands
| | - Arthur S C França
- Donders Institute for Brain, Cognition and Behavior, Radboud University, Nijmegen, 6525AJ, The Netherlands
- Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences, Amsterdam, 1105 BA, The Netherlands
| | - Ilse M Nauta
- MS Center Amsterdam, Neurology, Vrije Universiteit Amsterdam, Amsterdam UMC Location VUmc, Amsterdam, 1081HV, The Netherlands
| | - Cornelis J Stam
- Clinical Neurophysiology and MEG Center, Neurology, Vrije Universiteit Amsterdam, Amsterdam UMC Location VUmc, Amsterdam, 1081HV, The Netherlands
| | - Philip Scheltens
- Alzheimer Center Amsterdam, Neurology, Vrije Universiteit Amsterdam, Amsterdam UMC Location VUmc, Amsterdam, 1081HV, The Netherlands
| | - August B Smit
- Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Vrije Universiteit Amsterdam, Amsterdam, 1081HV, The Netherlands
| | - Alida A Gouw
- Alzheimer Center Amsterdam, Neurology, Vrije Universiteit Amsterdam, Amsterdam UMC Location VUmc, Amsterdam, 1081HV, The Netherlands
- Clinical Neurophysiology and MEG Center, Neurology, Vrije Universiteit Amsterdam, Amsterdam UMC Location VUmc, Amsterdam, 1081HV, The Netherlands
| | - Ronald E van Kesteren
- Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Vrije Universiteit Amsterdam, Amsterdam, 1081HV, The Netherlands.
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15
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Chen L, Wick ZC, Vetere LM, Vaughan N, Jurkowski A, Galas A, Diego KS, Philipsberg P, Cai DJ, Shuman T. Progressive excitability changes in the medial entorhinal cortex in the 3xTg mouse model of Alzheimer's disease pathology. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.30.542838. [PMID: 37398359 PMCID: PMC10312508 DOI: 10.1101/2023.05.30.542838] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
Alzheimer's disease (AD) is a chronic neurodegenerative disorder that is characterized by memory loss and progressive cognitive impairments. In mouse models of AD pathology, studies have found neuronal and synaptic deficits in the hippocampus, but less is known about what happens in the medial entorhinal cortex (MEC), which is the primary spatial input to the hippocampus and an early site of AD pathology. Here, we measured the neuronal intrinsic excitability and synaptic activity in MEC layer II (MECII) stellate cells, MECII pyramidal cells, and MEC layer III (MECIII) excitatory neurons at early (3 months) and late (10 months) time points in the 3xTg mouse model of AD pathology. At 3 months of age, prior to the onset of memory impairments, we found early hyperexcitability in MECII stellate and pyramidal cells' intrinsic properties, but this was balanced by a relative reduction in synaptic excitation (E) compared to inhibition (I), suggesting intact homeostatic mechanisms regulating activity in MECII. Conversely, MECIII neurons had reduced intrinsic excitability at this early time point with no change in the synaptic E/I ratio. By 10 months of age, after the onset of memory deficits, neuronal excitability of MECII pyramidal cells and MECIII excitatory neurons was largely normalized in 3xTg mice. However, MECII stellate cells remained hyperexcitable and this was further exacerbated by an increased synaptic E/I ratio. This observed combination of increased intrinsically and synaptically generated excitability suggests a breakdown in homeostatic mechanisms specifically in MECII stellate cells at this post-symptomatic time point. Together, these data suggest that the breakdown in homeostatic excitability mechanisms in MECII stellate cells may contribute to the emergence of memory deficits in AD.
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Affiliation(s)
- Lingxuan Chen
- Icahn School of Medicine at Mount Sinai, New York NY
- University of California Irvine, Irvine CA
| | | | | | - Nick Vaughan
- Icahn School of Medicine at Mount Sinai, New York NY
| | - Albert Jurkowski
- Icahn School of Medicine at Mount Sinai, New York NY
- CUNY Hunter College, New York NY
| | - Angelina Galas
- Icahn School of Medicine at Mount Sinai, New York NY
- New York University, New York NY
| | | | | | - Denise J. Cai
- Icahn School of Medicine at Mount Sinai, New York NY
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Morrone CD, Raghuraman R, Hussaini SA, Yu WH. Proteostasis failure exacerbates neuronal circuit dysfunction and sleep impairments in Alzheimer's disease. Mol Neurodegener 2023; 18:27. [PMID: 37085942 PMCID: PMC10119020 DOI: 10.1186/s13024-023-00617-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Accepted: 03/29/2023] [Indexed: 04/23/2023] Open
Abstract
Failed proteostasis is a well-documented feature of Alzheimer's disease, particularly, reduced protein degradation and clearance. However, the contribution of failed proteostasis to neuronal circuit dysfunction is an emerging concept in neurodegenerative research and will prove critical in understanding cognitive decline. Our objective is to convey Alzheimer's disease progression with the growing evidence for a bidirectional relationship of sleep disruption and proteostasis failure. Proteostasis dysfunction and tauopathy in Alzheimer's disease disrupts neurons that regulate the sleep-wake cycle, which presents behavior as impaired slow wave and rapid eye movement sleep patterns. Subsequent sleep loss further impairs protein clearance. Sleep loss is a defined feature seen early in many neurodegenerative disorders and contributes to memory impairments in Alzheimer's disease. Canonical pathological hallmarks, β-amyloid, and tau, directly disrupt sleep, and neurodegeneration of locus coeruleus, hippocampal and hypothalamic neurons from tau proteinopathy causes disruption of the neuronal circuitry of sleep. Acting in a positive-feedback-loop, sleep loss and circadian rhythm disruption then increase spread of β-amyloid and tau, through impairments of proteasome, autophagy, unfolded protein response and glymphatic clearance. This phenomenon extends beyond β-amyloid and tau, with interactions of sleep impairment with the homeostasis of TDP-43, α-synuclein, FUS, and huntingtin proteins, implicating sleep loss as an important consideration in an array of neurodegenerative diseases and in cases of mixed neuropathology. Critically, the dynamics of this interaction in the neurodegenerative environment are not fully elucidated and are deserving of further discussion and research. Finally, we propose sleep-enhancing therapeutics as potential interventions for promoting healthy proteostasis, including β-amyloid and tau clearance, mechanistically linking these processes. With further clinical and preclinical research, we propose this dynamic interaction as a diagnostic and therapeutic framework, informing precise single- and combinatorial-treatments for Alzheimer's disease and other brain disorders.
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Affiliation(s)
- Christopher Daniel Morrone
- Brain Health Imaging Centre, Centre for Addiction and Mental Health, 250 College St., Toronto, ON, M5T 1R8, Canada.
| | - Radha Raghuraman
- Taub Institute, Columbia University Irving Medical Center, 630W 168th Street, New York, NY, 10032, USA
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center, 630W 168th Street, New York, NY, 10032, USA
| | - S Abid Hussaini
- Taub Institute, Columbia University Irving Medical Center, 630W 168th Street, New York, NY, 10032, USA.
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center, 630W 168th Street, New York, NY, 10032, USA.
| | - Wai Haung Yu
- Brain Health Imaging Centre, Centre for Addiction and Mental Health, 250 College St., Toronto, ON, M5T 1R8, Canada.
- Geriatric Mental Health Research Services, Centre for Addiction and Mental Health, 250 College St., Toronto, ON, M5T 1R8, Canada.
- Department of Pharmacology and Toxicology, University of Toronto, Medical Sciences Building, 1 King's College Circle, Toronto, ON, M5S 1A8, Canada.
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Xiong H, Tang F, Guo Y, Xu R, Lei P. Neural Circuit Changes in Neurological Disorders: Evidence from in vivo Two-photon Imaging. Ageing Res Rev 2023; 87:101933. [PMID: 37061201 DOI: 10.1016/j.arr.2023.101933] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Accepted: 04/11/2023] [Indexed: 04/17/2023]
Abstract
Neural circuits, such as synaptic plasticity and neural activity, are critical components of healthy brain function. The consequent dynamic remodeling of neural circuits is an ongoing procedure affecting neuronal activities. Disruption of this essential process results in diseases. Advanced microscopic applications such as two-photon laser scanning microscopy have recently been applied to understand neural circuit changes during disease since it can visualize fine structural and functional cellular activation in living animals. In this review, we have summarized the latest work assessing the dynamic rewiring of postsynaptic dendritic spines and modulation of calcium transients in neurons of the intact living brain, focusing on their potential roles in neurological disorders (e.g. Alzheimer's disease, stroke, and epilepsy). Understanding the fine changes that occurred in the brain during disease is crucial for future clinical intervention developments.
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Affiliation(s)
- Huan Xiong
- Department of Neurosurgery, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, 610072, China; Chinese Academy of Sciences Sichuan Translational Medicine Research Hospital, Chengdu, 610072, China; Department of Neurology and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Sichuan, Chengdu, 610041, China
| | - Fei Tang
- Department of Neurology and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Sichuan, Chengdu, 610041, China
| | - Yujie Guo
- Department of Neurology and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Sichuan, Chengdu, 610041, China
| | - Ruxiang Xu
- Department of Neurosurgery, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, 610072, China; Chinese Academy of Sciences Sichuan Translational Medicine Research Hospital, Chengdu, 610072, China
| | - Peng Lei
- Department of Neurology and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Sichuan, Chengdu, 610041, China.
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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: 58] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [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
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19
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Wang J, Mei Y, Zhang X, Wei X, Zhang Y, Wang D, Huang J, Zhu K, Peng G, Sun B. Aberrant serotonergic signaling contributes to the hyperexcitability of CA1 pyramidal neurons in a mouse model of Alzheimer's disease. Cell Rep 2023; 42:112152. [PMID: 36821438 DOI: 10.1016/j.celrep.2023.112152] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2022] [Revised: 11/29/2022] [Accepted: 02/08/2023] [Indexed: 02/24/2023] Open
Abstract
Hyperactivity of pyramidal neurons (PNs) in CA1 is an early event in Alzheimer's disease. However, factors accounting for the hyperactivity of CA1 PNs remain to be completely investigated. In the present study, we report that the serotonergic signaling is abnormal in the hippocampus of hAPP-J20 mice. Interestingly, chemogenetic activation of serotonin (5-hydroxytryptamine; 5-HT) neurons in the median raphe nucleus (MRN) attenuates the activity of CA1 PNs in hAPP-J20 mice by regulating the intrinsic properties or inhibitory synaptic transmission of CA1 PNs through 5-HT3aR and/or 5-HT1aR. Furthermore, activating MRN 5-HT neurons improves memory in hAPP-J20 mice, and this effect is mediated by 5-HT3aR and 5-HT1aR. Direct activation of 5-HT3aR and 5-HT1aR with their selective agonists also improves the memory of hAPP-J20 mice. Together, we identify the impaired 5-HT/5-HT3aR and/or 5-HT/5-HT1aR signaling as pathways contributing to the hyperexcitability of CA1 PNs and the impaired cognition in hAPP-J20 mice.
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Affiliation(s)
- Jing Wang
- Department of Neurobiology and Department of Anesthesiology, the Children's Hospital, Zhejiang University School of Medicine and National Clinical Research Center for Child Health, Hangzhou, Zhejiang 310058, China; NHC and CAMS Key Laboratory of Medical Neurobiology, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Yufei Mei
- Department of Neurobiology and Department of Anesthesiology, the Children's Hospital, Zhejiang University School of Medicine and National Clinical Research Center for Child Health, Hangzhou, Zhejiang 310058, China; NHC and CAMS Key Laboratory of Medical Neurobiology, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, Zhejiang 310058, China; Brain Science and Advanced Technology Institute, School of Medicine, Wuhan University of Science and Technology, Wuhan, Hubei 430081, China.
| | - Xiaoqin Zhang
- Department of Physiology and Pharmacology, Medical School of Ningbo University, Ningbo, Zhejiang 315211, China
| | - Xiaojie Wei
- Department of Neurobiology and Department of Anesthesiology, the Children's Hospital, Zhejiang University School of Medicine and National Clinical Research Center for Child Health, Hangzhou, Zhejiang 310058, China; NHC and CAMS Key Laboratory of Medical Neurobiology, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Yiping Zhang
- Department of Neurobiology and Department of Anesthesiology, the Children's Hospital, Zhejiang University School of Medicine and National Clinical Research Center for Child Health, Hangzhou, Zhejiang 310058, China; NHC and CAMS Key Laboratory of Medical Neurobiology, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Dongpi Wang
- Department of Anesthesiology, The Children's Hospital, Zhejiang University School of Medicine and National Clinical Research Center for Child Health, Hangzhou, Zhejiang 310003, China
| | - Jinjin Huang
- Department of Anesthesiology, The Children's Hospital, Zhejiang University School of Medicine and National Clinical Research Center for Child Health, Hangzhou, Zhejiang 310003, China
| | - Keqing Zhu
- National Human Brain Bank for Health and Disease and Department of Neurology in Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Guoping Peng
- Department of Neurology, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310003, China.
| | - Binggui Sun
- Department of Neurobiology and Department of Anesthesiology, the Children's Hospital, Zhejiang University School of Medicine and National Clinical Research Center for Child Health, Hangzhou, Zhejiang 310058, China; NHC and CAMS Key Laboratory of Medical Neurobiology, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, Zhejiang 310058, China.
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20
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Neurotransmitters in Prevention and Treatment of Alzheimer's Disease. Int J Mol Sci 2023; 24:ijms24043841. [PMID: 36835251 PMCID: PMC9966535 DOI: 10.3390/ijms24043841] [Citation(s) in RCA: 40] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 02/01/2023] [Accepted: 02/02/2023] [Indexed: 02/17/2023] Open
Abstract
Alzheimer's disease (AD) is the most frequent cause of cognitive impairment in middle-aged and older populations. There is a lack of drugs that demonstrate significant efficacy in AD, so the study of the pathogenesis of AD is of great importance. More efficacious interventions are needed, as reflected by our population's fast aging. Synaptic plasticity is the capacity of neurons to adjust their connections, and it is strongly tied to learning and memory, cognitive function, and brain injury recovery. Changes in synaptic strength, such as long-term potentiation (LTP) or inhibition (LTD), are thought to represent the biological foundation of the early stages of learning and memory. The results of numerous studies confirm that neurotransmitters and their receptors play an important role in the regulation of synaptic plasticity. However, so far, there is no definite correlation between the function of neurotransmitters in aberrant neural oscillation and AD-related cognitive impairment. We summarized the AD process to understand the impact of neurotransmitters in the progression and pathogenesis of AD, including the current status of neurotransmitter target drugs, and the latest evidence of neurotransmitters' function and changes in the AD process.
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21
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Alexandersen CG, de Haan W, Bick C, Goriely A. A multi-scale model explains oscillatory slowing and neuronal hyperactivity in Alzheimer's disease. J R Soc Interface 2023; 20:20220607. [PMID: 36596460 PMCID: PMC9810432 DOI: 10.1098/rsif.2022.0607] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Alzheimer's disease is the most common cause of dementia and is linked to the spreading of pathological amyloid-β and tau proteins throughout the brain. Recent studies have highlighted stark differences in how amyloid-β and tau affect neurons at the cellular scale. On a larger scale, Alzheimer's patients are observed to undergo a period of early-stage neuronal hyperactivation followed by neurodegeneration and frequency slowing of neuronal oscillations. Herein, we model the spreading of both amyloid-β and tau across a human connectome and investigate how the neuronal dynamics are affected by disease progression. By including the effects of both amyloid-β and tau pathology, we find that our model explains AD-related frequency slowing, early-stage hyperactivation and late-stage hypoactivation. By testing different hypotheses, we show that hyperactivation and frequency slowing are not due to the topological interactions between different regions but are mostly the result of local neurotoxicity induced by amyloid-β and tau protein.
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Affiliation(s)
| | - Willem de Haan
- Alzheimer Center Amsterdam, Department of Neurology, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam UMC, Amsterdam, The Netherlands
| | - Christian Bick
- Mathematical Institute, University of Oxford, Oxford, UK,Department of Mathematics, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands,Amsterdam Neuroscience—Systems and Network Neuroscience, Amsterdam, The Netherlands
| | - Alain Goriely
- Mathematical Institute, University of Oxford, Oxford, UK
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22
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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: 216] [Impact Index Per Article: 108.0] [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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23
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Samudra N, Ranasinghe K, Kirsch H, Rankin K, Miller B. Etiology and Clinical Significance of Network Hyperexcitability in Alzheimer's Disease: Unanswered Questions and Next Steps. J Alzheimers Dis 2023; 92:13-27. [PMID: 36710680 DOI: 10.3233/jad-220983] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Cortical network hyperexcitability related to synaptic dysfunction in Alzheimer's disease (AD) is a potential target for therapeutic intervention. In recent years, there has been increased interest in the prevalence of silent seizures and interictal epileptiform discharges (IEDs, or seizure tendency), with both entities collectively termed "subclinical epileptiform activity" (SEA), on neurophysiologic studies in AD patients. SEA has been demonstrated to be common in AD, with prevalence estimates ranging between 22-54%. Converging lines of basic and clinical evidence imply that modifying a hyperexcitable state results in an improvement in cognition. In particular, though these results require further confirmation, post-hoc findings from a recent phase II clinical trial suggest a therapeutic effect with levetiracetam administration in patients with AD and IEDs. Here, we review key unanswered questions as well as potential clinical trial avenues. Specifically, we discuss postulated mechanisms and treatment of hyperexcitability in patients with AD, which are of interest in designing future disease-modifying therapies. Criteria to prompt screening and optimal screening methodology for hyperexcitability have yet to be defined, as does timing and personalization of therapeutic intervention.
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Affiliation(s)
- Niyatee Samudra
- Memory and Aging Center, University of California, San Francisco, San Francisco, CA, USA
| | - Kamalini Ranasinghe
- Memory and Aging Center, University of California, San Francisco, San Francisco, CA, USA
| | - Heidi Kirsch
- University of California, San Francisco Comprehensive Epilepsy Center, San Francisco, CA, USA
| | - Katherine Rankin
- Memory and Aging Center, University of California, San Francisco, San Francisco, CA, USA
| | - Bruce Miller
- Memory and Aging Center, University of California, San Francisco, San Francisco, CA, USA
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24
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Lacomme M, Hales SC, Brown TW, Stevanovic K, Jolicoeur C, Cai J, Bois T, Desrosiers M, Dalkara D, Cayouette M. Numb regulates Tau levels and prevents neurodegeneration in tauopathy mouse models. SCIENCE ADVANCES 2022; 8:eabm4295. [PMID: 36260685 PMCID: PMC9581485 DOI: 10.1126/sciadv.abm4295] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Accepted: 09/07/2022] [Indexed: 06/01/2023]
Abstract
Accumulation of the microtubule-associated protein Tau is linked to neuronal cell death in tauopathies, but how intraneuronal Tau levels are regulated in health and disease remains unclear. Here, we show that conditional inactivation of the trafficking adaptor protein Numb in retinal ganglion cells (RGCs) increases Tau levels and leads to axonal blebbing, which is followed by neuronal cell loss in aged mice. In the TauP301S mouse model of tauopathy, conditional inactivation of Numb in RGCs and spinal motoneurons accelerates neurodegeneration, and loss of Numb in motoneurons also leads to precocious hindlimb paralysis. Conversely, overexpression of the long isoform of Numb (Numb-72) decreases intracellular Tau levels and reduces axonal blebbing in TauP301S RGCs, leading to improved electrical activity in cultured neurons and improves performance in a visually guided behavior test in vivo. These results uncover Numb as a key regulator of intracellular Tau levels and identify Numb-72 as a potential therapeutic factor for tauopathies.
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Affiliation(s)
- Marine Lacomme
- Cellular Neurobiology Research Unit, Institut de recherches cliniques de Montréal (IRCM), Montreal, QC H2W 1R7, Canada
| | - Sarah C. Hales
- Cellular Neurobiology Research Unit, Institut de recherches cliniques de Montréal (IRCM), Montreal, QC H2W 1R7, Canada
- Integrated Program in Neuroscience, McGill University, Montreal, QC, Canada
| | - Thomas W. Brown
- Cellular Neurobiology Research Unit, Institut de recherches cliniques de Montréal (IRCM), Montreal, QC H2W 1R7, Canada
- Integrated Program in Neuroscience, McGill University, Montreal, QC, Canada
| | - Katarina Stevanovic
- Cellular Neurobiology Research Unit, Institut de recherches cliniques de Montréal (IRCM), Montreal, QC H2W 1R7, Canada
| | - Christine Jolicoeur
- Cellular Neurobiology Research Unit, Institut de recherches cliniques de Montréal (IRCM), Montreal, QC H2W 1R7, Canada
| | - Jenny Cai
- Cellular Neurobiology Research Unit, Institut de recherches cliniques de Montréal (IRCM), Montreal, QC H2W 1R7, Canada
| | - Therence Bois
- Cellular Neurobiology Research Unit, Institut de recherches cliniques de Montréal (IRCM), Montreal, QC H2W 1R7, Canada
| | - Melissa Desrosiers
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 17 rue Moreau, F-75012 Paris, France
| | - Deniz Dalkara
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 17 rue Moreau, F-75012 Paris, France
| | - Michel Cayouette
- Cellular Neurobiology Research Unit, Institut de recherches cliniques de Montréal (IRCM), Montreal, QC H2W 1R7, Canada
- Integrated Program in Neuroscience, McGill University, Montreal, QC, Canada
- Department of Medicine, Université de Montréal, Montreal, QC H3T 1J4, Canada
- Department of Anatomy and Cell Biology, Division of Experimental Medicine, McGill University, Montreal, QC H3A 0G4, Canada
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25
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Targa Dias Anastacio H, Matosin N, Ooi L. Neuronal hyperexcitability in Alzheimer's disease: what are the drivers behind this aberrant phenotype? Transl Psychiatry 2022; 12:257. [PMID: 35732622 PMCID: PMC9217953 DOI: 10.1038/s41398-022-02024-7] [Citation(s) in RCA: 156] [Impact Index Per Article: 52.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Revised: 06/01/2022] [Accepted: 06/08/2022] [Indexed: 12/13/2022] Open
Abstract
Alzheimer's disease (AD) is a progressive neurodegenerative disorder leading to loss of cognitive abilities and ultimately, death. With no cure available, limited treatments mostly focus on symptom management. Identifying early changes in the disease course may provide new therapeutic targets to halt or reverse disease progression. Clinical studies have shown that cortical and hippocampal hyperactivity are a feature shared by patients in the early stages of disease, progressing to hypoactivity during later stages of neurodegeneration. The exact mechanisms causing neuronal excitability changes are not fully characterized; however, animal and cell models have provided insights into some of the factors involved in this phenotype. In this review, we summarize the evidence for neuronal excitability changes over the course of AD onset and progression and the molecular mechanisms underpinning these differences. Specifically, we discuss contributors to aberrant neuronal excitability, including abnormal levels of intracellular Ca2+ and glutamate, pathological amyloid β (Aβ) and tau, genetic risk factors, including APOE, and impaired inhibitory interneuron and glial function. In light of recent research indicating hyperexcitability could be a predictive marker of cognitive dysfunction, we further argue that the hyperexcitability phenotype could be leveraged to improve the diagnosis and treatment of AD, and present potential targets for future AD treatment development.
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Affiliation(s)
- Helena Targa Dias Anastacio
- grid.510958.0Illawarra Health and Medical Research Institute, Wollongong, NSW 2522 Australia ,grid.1007.60000 0004 0486 528XMolecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW 2522 Australia
| | - Natalie Matosin
- grid.510958.0Illawarra Health and Medical Research Institute, Wollongong, NSW 2522 Australia ,grid.1007.60000 0004 0486 528XMolecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW 2522 Australia
| | - Lezanne Ooi
- Illawarra Health and Medical Research Institute, Wollongong, NSW, 2522, Australia. .,Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW, 2522, Australia.
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26
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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: 18] [Impact Index Per Article: 6.0] [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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27
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Tok S, Maurin H, Delay C, Crauwels D, Manyakov NV, Van Der Elst W, Moechars D, Drinkenburg WHIM. Neurophysiological effects of human-derived pathological tau conformers in the APPKM670/671NL.PS1/L166P amyloid mouse model of Alzheimer's disease. Sci Rep 2022; 12:7784. [PMID: 35546164 PMCID: PMC9094605 DOI: 10.1038/s41598-022-11582-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Accepted: 04/19/2022] [Indexed: 11/09/2022] Open
Abstract
Alzheimer’s Disease (AD) is a neurodegenerative disease characterized by two main pathological hallmarks: amyloid plaques and intracellular tau neurofibrillary tangles. However, a majority of studies focus on the individual pathologies and seldom on the interaction between the two pathologies. Herein, we present the longitudinal neuropathological and neurophysiological effects of a combined amyloid-tau model by hippocampal seeding of human-derived tau pathology in the APP.PS1/L166P amyloid animal model. We statistically assessed both neurophysiological and pathological changes using linear mixed modelling to determine if factors such as the age at which animals were seeded, genotype, seeding or buffer, brain region where pathology was quantified, and time-post injection differentially affect these outcomes. We report that AT8-positive tau pathology progressively develops and is facilitated by the amount of amyloid pathology present at the time of injection. The amount of AT8-positive tau pathology was influenced by the interaction of age at which the animal was injected, genotype, and time after injection. Baseline pathology-related power spectra and Higuchi Fractal Dimension (HFD) score alterations were noted in APP.PS1/L166P before any manipulations were performed, indicating a baseline difference associated with genotype. We also report immediate localized hippocampal dysfunction in the electroencephalography (EEG) power spectra associated with tau seeding which returned to comparable levels at 1 month-post-injection. Longitudinal effects of seeding indicated that tau-seeded wild-type mice showed an increase in gamma power earlier than buffer control comparisons which was influenced by the age at which the animal was injected. A reduction of hippocampal broadband power spectra was noted in tau-seeded wild-type mice, but absent in APP.PS1 animals. HFD scores appeared to detect subtle effects associated with tau seeding in APP.PS1 animals, which was differentially influenced by genotype. Notably, while tau histopathological changes were present, a lack of overt longitudinal electrophysiological alterations was noted, particularly in APP.PS1 animals that feature both pathologies after seeding, reiterating and underscoring the difficulty and complexity associated with elucidating physiologically relevant and translatable biomarkers of Alzheimer’s Disease at the early stages of the disease.
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Affiliation(s)
- S Tok
- Department of Neuroscience, Janssen Research and Development, Janssen Pharmaceutica NV, Turnhoutseweg 30, 2340, Beerse, Belgium. .,Faculty of Science and Engineering, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, The Netherlands.
| | - H Maurin
- Department of Neuroscience, Janssen Research and Development, Janssen Pharmaceutica NV, Turnhoutseweg 30, 2340, Beerse, Belgium
| | - C Delay
- Department of Neuroscience, Janssen Research and Development, Janssen Pharmaceutica NV, Turnhoutseweg 30, 2340, Beerse, Belgium
| | - D Crauwels
- Department of Neuroscience, Janssen Research and Development, Janssen Pharmaceutica NV, Turnhoutseweg 30, 2340, Beerse, Belgium
| | - N V Manyakov
- Data Sciences, Janssen Research and Development, Janssen Pharmaceutica NV, Turnhoutseweg 30, 2340, Beerse, Belgium
| | - W Van Der Elst
- Quantitative Sciences Janssen Research and Development, Janssen Pharmaceutica NV, Turnhoutseweg 30, 2340, Beerse, Belgium
| | - D Moechars
- Department of Neuroscience, Janssen Research and Development, Janssen Pharmaceutica NV, Turnhoutseweg 30, 2340, Beerse, Belgium
| | - W H I M Drinkenburg
- Department of Neuroscience, Janssen Research and Development, Janssen Pharmaceutica NV, Turnhoutseweg 30, 2340, Beerse, Belgium.,Faculty of Science and Engineering, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, The Netherlands
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28
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Stancu IC, Lodder C, Botella Lucena P, Vanherle S, Gutiérrez de Ravé M, Terwel D, Bottelbergs A, Dewachter I. The NLRP3 inflammasome modulates tau pathology and neurodegeneration in a tauopathy model. Glia 2022; 70:1117-1132. [PMID: 35174546 PMCID: PMC9307007 DOI: 10.1002/glia.24160] [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: 12/18/2021] [Revised: 02/02/2022] [Accepted: 02/03/2022] [Indexed: 12/28/2022]
Abstract
An active role of neuroinflammation and the NLRP3 inflammasome in Alzheimer's disease and related tauopathies is increasingly identified, supporting NLRP3 as an interesting therapeutic target. However, its effect on tau‐associated neurodegeneration, a key‐process in tauopathies, remains unknown. While tau pathology and neurodegeneration are closely correlated, different tau forms may act as culprits in both characteristics and NLRP3‐dependent microglial processes may differently affect both processes, indicating the need to study the role of NLRP3 in both processes concomitantly. To study the role of NLRP3 on tau pathology, prion‐like propagation and tau‐associated neurodegeneration we generated crosses of NLRP3 deficient mice with tauP301S (PS19) transgenic mice. In this model we studied non‐seeded tau pathology and hippocampal atrophy, reminiscent characteristics of tauopathies. Tau pathology in hippocampus and cortex was significantly decreased in tau.NLRP3−/− versus tau.NLRP3+/+ mice. Importantly, tau.NLRP3−/− mice also displayed significantly decreased hippocampal atrophy, indicating a role of NLRP3 in neurodegeneration. We furthermore assessed the effect of NLRP3 deficiency on tau propagation and associated hippocampal atrophy. NLRP3 deficiency significantly decreased prion‐like seeding and propagation of tau pathology, reflected in decreased tau pathology in ipsi‐ and contralateral hippocampus and cortex in tau.NLRP3−/− following tau seeding. Most importantly, hippocampal atrophy was significantly less in tau‐seeded tau.NLRP3−/− mice at 8 months. We here demonstrate for the first time that NLRP3 activation affects tau‐associated neurodegeneration and seeded and non‐seeded tau pathology, hence affecting key molecular processes in tauopathies. Our data thereby provide key‐information in the validation of NLRP3 inflammasome as therapeutic target for AD and related tauopathies.
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Affiliation(s)
- Ilie Cosmin Stancu
- Department of Neurosciences, Biomedical Research Institute, Hasselt University, Hasselt, Belgium
| | - Chritica Lodder
- Department of Neurosciences, Biomedical Research Institute, Hasselt University, Hasselt, Belgium
| | - Pablo Botella Lucena
- Department of Neurosciences, Biomedical Research Institute, Hasselt University, Hasselt, Belgium
| | - Sarah Vanherle
- Department of Neurosciences, Biomedical Research Institute, Hasselt University, Hasselt, Belgium
| | - Manuel Gutiérrez de Ravé
- Department of Neurosciences, Biomedical Research Institute, Hasselt University, Hasselt, Belgium
| | - Dick Terwel
- Department of Neurosciences, Biomedical Research Institute, Hasselt University, Hasselt, Belgium
| | - Astrid Bottelbergs
- Neuroscience Department, Janssen Research and Development, A Division of Janssen Pharmaceutica NV, Beerse, Belgium
| | - Ilse Dewachter
- Department of Neurosciences, Biomedical Research Institute, Hasselt University, Hasselt, Belgium
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29
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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: 54] [Impact Index Per Article: 13.5] [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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30
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Tok S, Ahnaou A, Drinkenburg W. Functional Neurophysiological Biomarkers of Early-Stage Alzheimer's Disease: A Perspective of Network Hyperexcitability in Disease Progression. J Alzheimers Dis 2021; 88:809-836. [PMID: 34420957 PMCID: PMC9484128 DOI: 10.3233/jad-210397] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Network hyperexcitability (NH) has recently been suggested as a potential neurophysiological indicator of Alzheimer’s disease (AD), as new, more accurate biomarkers of AD are sought. NH has generated interest as a potential indicator of certain stages in the disease trajectory and even as a disease mechanism by which network dysfunction could be modulated. NH has been demonstrated in several animal models of AD pathology and multiple lines of evidence point to the existence of NH in patients with AD, strongly supporting the physiological and clinical relevance of this readout. Several hypotheses have been put forward to explain the prevalence of NH in animal models through neurophysiological, biochemical, and imaging techniques. However, some of these hypotheses have been built on animal models with limitations and caveats that may have derived NH through other mechanisms or mechanisms without translational validity to sporadic AD patients, potentially leading to an erroneous conclusion of the underlying cause of NH occurring in patients with AD. In this review, we discuss the substantiation for NH in animal models of AD pathology and in human patients, as well as some of the hypotheses considering recently developed animal models that challenge existing hypotheses and mechanisms of NH. In addition, we provide a preclinical perspective on how the development of animal models incorporating AD-specific NH could provide physiologically relevant translational experimental data that may potentially aid the discovery and development of novel therapies for AD.
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Affiliation(s)
- Sean Tok
- Department of Neuroscience, Janssen Research & Development, Janssen Pharmaceutica NV, Beerse, Belgium.,Groningen Institute for Evolutionary Life Sciences, Faculty of Science and Engineering, University of Groningen, The Netherlands
| | - Abdallah Ahnaou
- Department of Neuroscience, Janssen Research & Development, Janssen Pharmaceutica NV, Beerse, Belgium
| | - Wilhelmus Drinkenburg
- Department of Neuroscience, Janssen Research & Development, Janssen Pharmaceutica NV, Beerse, Belgium.,Groningen Institute for Evolutionary Life Sciences, Faculty of Science and Engineering, University of Groningen, The Netherlands
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31
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Neuronal Network Excitability in Alzheimer's Disease: The Puzzle of Similar versus Divergent Roles of Amyloid β and Tau. eNeuro 2021; 8:ENEURO.0418-20.2020. [PMID: 33741601 PMCID: PMC8174042 DOI: 10.1523/eneuro.0418-20.2020] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Revised: 12/02/2020] [Accepted: 12/18/2020] [Indexed: 12/12/2022] Open
Abstract
Alzheimer’s disease (AD) is the most frequent neurodegenerative disorder that commonly causes dementia in the elderly. Recent evidence indicates that network abnormalities, including hypersynchrony, altered oscillatory rhythmic activity, interneuron dysfunction, and synaptic depression, may be key mediators of cognitive decline in AD. In this review, we discuss characteristics of neuronal network excitability in AD, and the role of Aβ and tau in the induction of network hyperexcitability. Many patients harboring genetic mutations that lead to increased Aβ production suffer from seizures and epilepsy before the development of plaques. Similarly, pathologic accumulation of hyperphosphorylated tau has been associated with hyperexcitability in the hippocampus. We present common and divergent roles of tau and Aβ on neuronal hyperexcitability in AD, and hypotheses that could serve as a template for future experiments.
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32
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Jafari M, Schumacher AM, Snaidero N, Ullrich Gavilanes EM, Neziraj T, Kocsis-Jutka V, Engels D, Jürgens T, Wagner I, Weidinger JDF, Schmidt SS, Beltrán E, Hagan N, Woodworth L, Ofengeim D, Gans J, Wolf F, Kreutzfeldt M, Portugues R, Merkler D, Misgeld T, Kerschensteiner M. Phagocyte-mediated synapse removal in cortical neuroinflammation is promoted by local calcium accumulation. Nat Neurosci 2021; 24:355-367. [PMID: 33495636 DOI: 10.1038/s41593-020-00780-7] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Accepted: 12/16/2020] [Indexed: 01/30/2023]
Abstract
Cortical pathology contributes to chronic cognitive impairment of patients suffering from the neuroinflammatory disease multiple sclerosis (MS). How such gray matter inflammation affects neuronal structure and function is not well understood. In the present study, we use functional and structural in vivo imaging in a mouse model of cortical MS to demonstrate that bouts of cortical inflammation disrupt cortical circuit activity coincident with a widespread, but transient, loss of dendritic spines. Spines destined for removal show local calcium accumulations and are subsequently removed by invading macrophages or activated microglia. Targeting phagocyte activation with a new antagonist of the colony-stimulating factor 1 receptor prevents cortical synapse loss. Overall, our study identifies synapse loss as a key pathological feature of inflammatory gray matter lesions that is amenable to immunomodulatory therapy.
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Affiliation(s)
- Mehrnoosh Jafari
- Institute of Clinical Neuroimmunology, University Hospital, Ludwig-Maximilians University Munich, Munich, Germany.,Biomedical Center, Faculty of Medicine, Ludwig-Maximilians University Munich, Munich, Germany
| | - Adrian-Minh Schumacher
- Institute of Clinical Neuroimmunology, University Hospital, Ludwig-Maximilians University Munich, Munich, Germany.,Biomedical Center, Faculty of Medicine, Ludwig-Maximilians University Munich, Munich, Germany
| | - Nicolas Snaidero
- Institute of Clinical Neuroimmunology, University Hospital, Ludwig-Maximilians University Munich, Munich, Germany.,Institute of Neuronal Cell Biology, Technical University of Munich, Munich, Germany.,German Center for Neurodegenerative Diseases, Munich, Germany
| | - Emily M Ullrich Gavilanes
- Institute of Clinical Neuroimmunology, University Hospital, Ludwig-Maximilians University Munich, Munich, Germany.,Biomedical Center, Faculty of Medicine, Ludwig-Maximilians University Munich, Munich, Germany
| | - Tradite Neziraj
- Institute of Clinical Neuroimmunology, University Hospital, Ludwig-Maximilians University Munich, Munich, Germany.,Biomedical Center, Faculty of Medicine, Ludwig-Maximilians University Munich, Munich, Germany
| | - Virág Kocsis-Jutka
- Institute of Clinical Neuroimmunology, University Hospital, Ludwig-Maximilians University Munich, Munich, Germany.,Biomedical Center, Faculty of Medicine, Ludwig-Maximilians University Munich, Munich, Germany
| | - Daniel Engels
- Institute of Clinical Neuroimmunology, University Hospital, Ludwig-Maximilians University Munich, Munich, Germany.,Biomedical Center, Faculty of Medicine, Ludwig-Maximilians University Munich, Munich, Germany
| | - Tanja Jürgens
- Department of Pathology and Immunology, University of Geneva, Geneva, Switzerland
| | - Ingrid Wagner
- Department of Pathology and Immunology, University of Geneva, Geneva, Switzerland
| | - Juan Daniel Flórez Weidinger
- Max Planck Institute for Dynamics and Self-Organization, Göttingen, Germany.,Bernstein Center for Computational Neuroscience, University of Göttingen, Göttingen, Germany.,Max Planck Institute for Experimental Medicine, Göttingen, Germany.,Center for Biostructural Imaging of Neurodegeneration, Göttingen, Germany
| | - Stephanie S Schmidt
- Institute of Clinical Neuroimmunology, University Hospital, Ludwig-Maximilians University Munich, Munich, Germany
| | - Eduardo Beltrán
- Institute of Clinical Neuroimmunology, University Hospital, Ludwig-Maximilians University Munich, Munich, Germany.,Biomedical Center, Faculty of Medicine, Ludwig-Maximilians University Munich, Munich, Germany
| | - Nellwyn Hagan
- Rare and Neurological Disease Research, Sanofi, Framingham, MA, USA
| | - Lisa Woodworth
- Rare and Neurological Disease Research, Sanofi, Framingham, MA, USA
| | - Dimitry Ofengeim
- Rare and Neurological Disease Research, Sanofi, Framingham, MA, USA
| | - Joseph Gans
- Translational Sciences Genomics, Sanofi, Framingham, MA, USA
| | - Fred Wolf
- Max Planck Institute for Dynamics and Self-Organization, Göttingen, Germany.,Bernstein Center for Computational Neuroscience, University of Göttingen, Göttingen, Germany.,Max Planck Institute for Experimental Medicine, Göttingen, Germany.,Center for Biostructural Imaging of Neurodegeneration, Göttingen, Germany.,Campus Institute for Dynamics of Biological Networks, University of Göttingen, Göttingen, Germany
| | - Mario Kreutzfeldt
- Department of Pathology and Immunology, University of Geneva, Geneva, Switzerland.,Division of Clinical Pathology, Geneva University Hospital, Geneva, Switzerland
| | - Ruben Portugues
- Sensorimotor Control, Max Planck Institute of Neurobiology, Munich, Germany.,Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Doron Merkler
- Department of Pathology and Immunology, University of Geneva, Geneva, Switzerland. .,Division of Clinical Pathology, Geneva University Hospital, Geneva, Switzerland.
| | - Thomas Misgeld
- Institute of Neuronal Cell Biology, Technical University of Munich, Munich, Germany. .,German Center for Neurodegenerative Diseases, Munich, Germany. .,Munich Cluster for Systems Neurology (SyNergy), Munich, Germany.
| | - Martin Kerschensteiner
- Institute of Clinical Neuroimmunology, University Hospital, Ludwig-Maximilians University Munich, Munich, Germany. .,Biomedical Center, Faculty of Medicine, Ludwig-Maximilians University Munich, Munich, Germany. .,Munich Cluster for Systems Neurology (SyNergy), Munich, Germany.
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33
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Identification and quantification of neuronal ensembles in optical imaging experiments. J Neurosci Methods 2020; 351:109046. [PMID: 33359231 DOI: 10.1016/j.jneumeth.2020.109046] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 12/12/2020] [Accepted: 12/15/2020] [Indexed: 12/30/2022]
Abstract
Recent technical advances in molecular biology and optical imaging have made it possible to record from up to thousands of densely packed neurons in superficial and deep brain regions in vivo, with cellular subtype specificity and high spatiotemporal fidelity. Such optical neurotechnologies are enabling increasingly fine-scaled studies of neuronal circuits and reliably co-active groups of neurons, so-called ensembles. Neuronal ensembles are thought to constitute the basic functional building blocks of brain systems, potentially exhibiting collective computational properties. While the technical framework of in vivo optical imaging and quantification of neuronal activity follows certain widely held standards, analytical methods for study of neuronal co-activity and ensembles lack consensus and are highly varied across the field. Here we provide a comprehensive step-by-step overview of theoretical, experimental, and analytical considerations for the identification and quantification of neuronal ensemble dynamics in high-resolution in vivo optical imaging studies.
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34
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Toniolo S, Sen A, Husain M. Modulation of Brain Hyperexcitability: Potential New Therapeutic Approaches in Alzheimer's Disease. Int J Mol Sci 2020; 21:E9318. [PMID: 33297460 PMCID: PMC7730926 DOI: 10.3390/ijms21239318] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 11/30/2020] [Accepted: 12/05/2020] [Indexed: 12/12/2022] Open
Abstract
People with Alzheimer's disease (AD) have significantly higher rates of subclinical and overt epileptiform activity. In animal models, oligomeric Aβ amyloid is able to induce neuronal hyperexcitability even in the early phases of the disease. Such aberrant activity subsequently leads to downstream accumulation of toxic proteins, and ultimately to further neurodegeneration and neuronal silencing mediated by concomitant tau accumulation. Several neurotransmitters participate in the initial hyperexcitable state, with increased synaptic glutamatergic tone and decreased GABAergic inhibition. These changes appear to activate excitotoxic pathways and, ultimately, cause reduced long-term potentiation, increased long-term depression, and increased GABAergic inhibitory remodelling at the network level. Brain hyperexcitability has therefore been identified as a potential target for therapeutic interventions aimed at enhancing cognition, and, possibly, disease modification in the longer term. Clinical trials are ongoing to evaluate the potential efficacy in targeting hyperexcitability in AD, with levetiracetam showing some encouraging effects. Newer compounds and techniques, such as gene editing via viral vectors or brain stimulation, also show promise. Diagnostic challenges include identifying best biomarkers for measuring sub-clinical epileptiform discharges. Determining the timing of any intervention is critical and future trials will need to carefully stratify participants with respect to the phase of disease pathology.
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Affiliation(s)
- Sofia Toniolo
- Cognitive Neurology Group, Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, University of Oxford, Oxford OX3 9DU, UK;
- Wellcome Trust Centre for Integrative Neuroimaging, Department of Experimental Psychology, University of Oxford, Oxford OX2 6AE, UK
| | - Arjune Sen
- Oxford Epilepsy Research Group, Nuffield Department Clinical Neurosciences, John Radcliffe Hospital, Oxford OX3 9DU, UK;
| | - Masud Husain
- Cognitive Neurology Group, Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, University of Oxford, Oxford OX3 9DU, UK;
- Wellcome Trust Centre for Integrative Neuroimaging, Department of Experimental Psychology, University of Oxford, Oxford OX2 6AE, UK
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35
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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: 0.8] [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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36
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Busche MA, Hyman BT. Synergy between amyloid-β and tau in Alzheimer's disease. Nat Neurosci 2020; 23:1183-1193. [PMID: 32778792 PMCID: PMC11831977 DOI: 10.1038/s41593-020-0687-6] [Citation(s) in RCA: 715] [Impact Index Per Article: 143.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Accepted: 07/06/2020] [Indexed: 12/24/2022]
Abstract
Patients with Alzheimer's disease (AD) present with both extracellular amyloid-β (Aβ) plaques and intracellular tau-containing neurofibrillary tangles in the brain. For many years, the prevailing view of AD pathogenesis has been that changes in Aβ precipitate the disease process and initiate a deleterious cascade involving tau pathology and neurodegeneration. Beyond this 'triggering' function, it has been typically presumed that Aβ and tau act independently and in the absence of specific interaction. However, accumulating evidence now suggests otherwise and contends that both pathologies have synergistic effects. This could not only help explain negative results from anti-Aβ clinical trials but also suggest that trials directed solely at tau may need to be reconsidered. Here, drawing from extensive human and disease model data, we highlight the latest evidence base pertaining to the complex Aβ-tau interaction and underscore its crucial importance to elucidating disease pathogenesis and the design of next-generation AD therapeutic trials.
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Affiliation(s)
- Marc Aurel Busche
- UK Dementia Research Institute at UCL, University College London, London, UK.
| | - Bradley T Hyman
- MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital, Harvard Medical School, Boston, USA
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37
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Ni R, Chen Z, Gerez JA, Shi G, Zhou Q, Riek R, Nilsson KPR, Razansky D, Klohs J. Detection of cerebral tauopathy in P301L mice using high-resolution large-field multifocal illumination fluorescence microscopy. BIOMEDICAL OPTICS EXPRESS 2020; 11:4989-5002. [PMID: 33014595 PMCID: PMC7510859 DOI: 10.1364/boe.395803] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 07/23/2020] [Accepted: 07/23/2020] [Indexed: 06/11/2023]
Abstract
Current intravital microscopy techniques visualize tauopathy with high-resolution, but have a small field-of-view and depth-of-focus. Herein, we report a transcranial detection of tauopathy over the entire cortex of P301L tauopathy mice using large-field multifocal illumination (LMI) fluorescence microscopy technique and luminescent conjugated oligothiophenes. In vitro assays revealed that fluorescent ligand h-FTAA is optimal for in vivo tau imaging, which was confirmed by observing elevated probe retention in the cortex of P301L mice compared to non-transgenic littermates. Immunohistochemical staining further verified the specificity of h-FTAA to detect tauopathy in P301L mice. The new imaging platform can be leveraged in pre-clinical mechanistic studies of tau spreading and clearance as well as longitudinal monitoring of tau targeting therapeutics.
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Affiliation(s)
- Ruiqing Ni
- University of Zurich & ETH Zurich, Institute for Biomedical Engineering, Department of Information Technology and Electrical Engineering, Wolfgang-Pauli-strasse 27 HIT E22.4, 8093, Zurich, Switzerland
- University of Zurich, Zurich Neuroscience Center, Zurich, Switzerland
| | - Zhenyue Chen
- University of Zurich & ETH Zurich, Institute for Biomedical Engineering, Department of Information Technology and Electrical Engineering, Wolfgang-Pauli-strasse 27 HIT E22.4, 8093, Zurich, Switzerland
- University of Zurich, Faculty of Medicine and Institute of Pharmacology and Toxicology, Zurich, Switzerland
| | - Juan A. Gerez
- ETH Zurich, Laboratory of Physical Chemistry, Department of Chemistry and Applied Biosciences, Zurich, Switzerland
| | - Gloria Shi
- University of Zurich & ETH Zurich, Institute for Biomedical Engineering, Department of Information Technology and Electrical Engineering, Wolfgang-Pauli-strasse 27 HIT E22.4, 8093, Zurich, Switzerland
| | - Quanyu Zhou
- University of Zurich & ETH Zurich, Institute for Biomedical Engineering, Department of Information Technology and Electrical Engineering, Wolfgang-Pauli-strasse 27 HIT E22.4, 8093, Zurich, Switzerland
- University of Zurich, Faculty of Medicine and Institute of Pharmacology and Toxicology, Zurich, Switzerland
| | - Roland Riek
- ETH Zurich, Laboratory of Physical Chemistry, Department of Chemistry and Applied Biosciences, Zurich, Switzerland
| | - K. Peter R. Nilsson
- Linköping University, Division of Chemistry, Department of Physics, Chemistry and Biology, Linköping, Sweden
| | - Daniel Razansky
- University of Zurich & ETH Zurich, Institute for Biomedical Engineering, Department of Information Technology and Electrical Engineering, Wolfgang-Pauli-strasse 27 HIT E22.4, 8093, Zurich, Switzerland
- University of Zurich, Zurich Neuroscience Center, Zurich, Switzerland
- University of Zurich, Faculty of Medicine and Institute of Pharmacology and Toxicology, Zurich, Switzerland
| | - Jan Klohs
- University of Zurich & ETH Zurich, Institute for Biomedical Engineering, Department of Information Technology and Electrical Engineering, Wolfgang-Pauli-strasse 27 HIT E22.4, 8093, Zurich, Switzerland
- University of Zurich, Zurich Neuroscience Center, Zurich, Switzerland
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38
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Lim KH, Joo JY, Baek KH. The potential roles of deubiquitinating enzymes in brain diseases. Ageing Res Rev 2020; 61:101088. [PMID: 32470641 DOI: 10.1016/j.arr.2020.101088] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Revised: 05/12/2020] [Accepted: 05/13/2020] [Indexed: 02/06/2023]
Abstract
Most proteins undergo posttranslational modification such as acetylation, methylation, phosphorylation, biotinylation, and ubiquitination to regulate various cellular processes. Ubiquitin-targeted proteins from the ubiquitin-proteasome system (UPS) are degraded by 26S proteasome, along with this, deubiquitinating enzymes (DUBs) have specific activity against the UPS through detaching of ubiquitin on ubiquitin-targeted proteins. Balancing between protein expression and degradation through interplay between the UPS and DUBs is important to maintain cell homeostasis, and abnormal expression and elongation of proteins lead to diverse diseases such as cancer, diabetes, and autoimmune response. Therefore, development of DUB inhibitors as therapeutic targets has been challenging. In addition, understanding of the roles of DUBs in neurodegeneration, specifically brain diseases, has emerged gradually. This review highlights recent studies on the molecular mechanisms for DUBs, and discusses potential therapeutic targets for DUBs in cases of brain diseases.
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Affiliation(s)
- Key-Hwan Lim
- Neurodegenerative Diseases Research Group, Korea Brain Research Institute, Choeomdan-Ro 61, Daegu 41068, Republic of Korea.
| | - Jae-Yeol Joo
- Neurodegenerative Diseases Research Group, Korea Brain Research Institute, Choeomdan-Ro 61, Daegu 41068, Republic of Korea
| | - Kwang-Hyun Baek
- Department of Biomedical Science, CHA University, Gyeonggi-Do 13488, Republic of Korea
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39
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Harris SS, Wolf F, De Strooper B, Busche MA. Tipping the Scales: Peptide-Dependent Dysregulation of Neural Circuit Dynamics in Alzheimer’s Disease. Neuron 2020; 107:417-435. [DOI: 10.1016/j.neuron.2020.06.005] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Revised: 04/24/2020] [Accepted: 06/01/2020] [Indexed: 02/07/2023]
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40
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Ryan TM, Hinojosa AJ, Vroman R, Papasavvas C, Lagnado L. Correction of z-motion artefacts to allow population imaging of synaptic activity in behaving mice. J Physiol 2020; 598:1809-1827. [PMID: 32020615 PMCID: PMC7318612 DOI: 10.1113/jp278957] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Accepted: 01/24/2020] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS Motion artefacts associated with motor behaviour are an inevitable problem of multiphoton imaging in awake behaving animals, particularly when imaging synapses. Correction of axial motion artefacts usually requires volumetric imaging resulting in slower rates of acquisition. We describe a method to correct z-motion artefacts that is easy to implement and allows population imaging of synaptic activity while scanning a single plane in a standard multiphoton microscope. The method uses a reference volume acquired in two colour channels - an activity reporter and an anatomical marker of blood vessels. The procedure estimates the z-displacement in every frame and applies an intensity correction in which the z intensity profile for each synapse is modelled as a Moffat function. We demonstrate that the method allows synaptic calcium signals to be collected from populations of synaptic boutons in mouse primary visual cortex during locomotion. ABSTRACT Functional imaging of head-fixed, behaving mice using two-photon imaging of fluorescent activity reporters has become a powerful tool for studying the function of the brain. Motion artefacts are an inevitable problem during such experiments and are routinely corrected for in x and y dimensions. However, axial (z) shifts of several microns can also occur, leading to intensity fluctuations in structures such as synapses that are small compared to the axial point-spread function of the microscope. Here we present a simple strategy to correct z-motion artefacts arising over the course of a time-series experiment in a single optical plane. Displacement in z was calculated using dye-filled blood vessels as an anatomical marker, providing high contrast images and accuracy to within ∼0.1 µm. The axial profiles of ROIs corresponding to synapses were described using a Moffat function and this 'ROI-spread function' used to correct activity traces on an ROI-by-ROI basis. We demonstrate the accuracy and utility of the procedures in simulation experiments using fluorescent beads and then apply them to correcting measurements of synaptic activity in populations of vasoactive-intestinal peptide (VIP) interneurons expressing the synaptic reporter SyGCaMP6f. Correction of z-motion artefacts had a substantial impact on the apparent correlation between synaptic activity and running speed, demonstrating the importance of correcting these when performing imaging experiments in awake mice.
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Affiliation(s)
- Thomas Michael Ryan
- Sussex NeuroscienceSchool of Life SciencesUniversity of SussexBrightonBN1 9QGUK
| | | | - Rozan Vroman
- Sussex NeuroscienceSchool of Life SciencesUniversity of SussexBrightonBN1 9QGUK
| | | | - Leon Lagnado
- Sussex NeuroscienceSchool of Life SciencesUniversity of SussexBrightonBN1 9QGUK
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Mehr A, Hick M, Ludewig S, Müller M, Herrmann U, von Engelhardt J, Wolfer DP, Korte M, Müller UC. Lack of APP and APLP2 in GABAergic Forebrain Neurons Impairs Synaptic Plasticity and Cognition. Cereb Cortex 2020; 30:4044-4063. [PMID: 32219307 DOI: 10.1093/cercor/bhaa025] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Amyloid-β precursor protein (APP) is central to the pathogenesis of Alzheimer's disease, yet its physiological functions remain incompletely understood. Previous studies had indicated important synaptic functions of APP and the closely related homologue APLP2 in excitatory forebrain neurons for spine density, synaptic plasticity, and behavior. Here, we show that APP is also widely expressed in several interneuron subtypes, both in hippocampus and cortex. To address the functional role of APP in inhibitory neurons, we generated mice with a conditional APP/APLP2 double knockout (cDKO) in GABAergic forebrain neurons using DlxCre mice. These DlxCre cDKO mice exhibit cognitive deficits in hippocampus-dependent spatial learning and memory tasks, as well as impairments in species-typic nesting and burrowing behaviors. Deficits at the behavioral level were associated with altered neuronal morphology and synaptic plasticity Long-Term Potentiation (LTP). Impaired basal synaptic transmission at the Schafer collateral/CA1 pathway, which was associated with altered compound excitatory/inhibitory synaptic currents and reduced action potential firing of CA1 pyramidal cells, points to a disrupted excitation/inhibition balance in DlxCre cDKOs. Together, these impairments may lead to hippocampal dysfunction. Collectively, our data reveal a crucial role of APP family proteins in inhibitory interneurons to maintain functional network activity.
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Affiliation(s)
- Annika Mehr
- Department of Functional Genomics, Institute of Pharmacy and Molecular Biotechnology (IPMB), University of Heidelberg, 69120 Heidelberg, Germany
| | - Meike Hick
- Institute of Clinical Neuroanatomy, Neuroscience Center, Goethe-University, 60590 Frankfurt am Main, Germany
| | - Susann Ludewig
- Division of Cellular Neurobiology, Zoological Institute, Technische Universität Braunschweig, 38106 Braunschweig, Germany
| | - Michaela Müller
- Institute of Pathophysiology, University Medical Center of the Johannes Gutenberg University Mainz, 55128 Mainz, Germany
| | - Ulrike Herrmann
- Division of Cellular Neurobiology, Zoological Institute, Technische Universität Braunschweig, 38106 Braunschweig, Germany
| | - Jakob von Engelhardt
- Institute of Pathophysiology, University Medical Center of the Johannes Gutenberg University Mainz, 55128 Mainz, Germany
| | - David P Wolfer
- Institute of Anatomy, University of Zürich, 8057 Zürich, Switzerland.,Institute of Human Movement Sciences and Sport, ETH Zürich, 8057 Zürich, Switzerland
| | - Martin Korte
- Division of Cellular Neurobiology, Zoological Institute, Technische Universität Braunschweig, 38106 Braunschweig, Germany.,AG Neuroinflammation and Neurodegeneration, Helmholtz Centre for Infection Research, 38124 Braunschweig, Germany
| | - Ulrike C Müller
- Department of Functional Genomics, Institute of Pharmacy and Molecular Biotechnology (IPMB), University of Heidelberg, 69120 Heidelberg, Germany.,Division of Cellular Neurobiology, Zoological Institute, Technische Universität Braunschweig, 38106 Braunschweig, Germany
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McAllister BB, Lacoursiere SG, Sutherland RJ, Mohajerani MH. Intracerebral seeding of amyloid-β and tau pathology in mice: Factors underlying prion-like spreading and comparisons with α-synuclein. Neurosci Biobehav Rev 2020; 112:1-27. [PMID: 31996301 DOI: 10.1016/j.neubiorev.2020.01.026] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Revised: 01/15/2020] [Accepted: 01/21/2020] [Indexed: 01/08/2023]
Abstract
Alzheimer's disease (AD) is characterized neuropathologically by progressive neurodegeneration and by the presence of amyloid plaques and neurofibrillary tangles. These plaques and tangles are composed, respectively, of amyloid-beta (Aβ) and tau proteins. While long recognized as hallmarks of AD, it remains unclear what causes the formation of these insoluble deposits. One theory holds that prion-like templated misfolding of Aβ and tau induces these proteins to form pathological aggregates, and propagation of this misfolding causes the stereotyped progression of pathology commonly seen in AD. Supporting this theory, numerous studies have been conducted in which aggregated Aβ, tau, or α-synuclein is injected intracerebrally into pathology-free host animals, resulting in robust formation of pathology. Here, we review this literature, focusing on in vivo intracerebral seeding of Aβ and tau in mice. We compare the results of these experiments to what is known about the seeding and spread of α-synuclein pathology, and we discuss how this research informs our understanding of the factors underlying the onset, progression, and outcomes of proteinaceous pathologies.
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Affiliation(s)
- Brendan B McAllister
- Department of Neuroscience, Canadian Centre for Behavioural Neuroscience, University of Lethbridge, Lethbridge, AB, T1K 3M4, Canada
| | - Sean G Lacoursiere
- Department of Neuroscience, Canadian Centre for Behavioural Neuroscience, University of Lethbridge, Lethbridge, AB, T1K 3M4, Canada
| | - Robert J Sutherland
- Department of Neuroscience, Canadian Centre for Behavioural Neuroscience, University of Lethbridge, Lethbridge, AB, T1K 3M4, Canada.
| | - Majid H Mohajerani
- Department of Neuroscience, Canadian Centre for Behavioural Neuroscience, University of Lethbridge, Lethbridge, AB, T1K 3M4, Canada.
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Paudel YN, Angelopoulou E, Jones NC, O’Brien TJ, Kwan P, Piperi C, Othman I, Shaikh MF. Tau Related Pathways as a Connecting Link between Epilepsy and Alzheimer's Disease. ACS Chem Neurosci 2019; 10:4199-4212. [PMID: 31532186 DOI: 10.1021/acschemneuro.9b00460] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Emerging findings point toward an important interconnection between epilepsy and Alzheimer's disease (AD) pathogenesis. Patients with epilepsy (PWE) commonly exhibit cognitive impairment similar to AD patients, who in turn are at a higher risk of developing epilepsy compared to age-matched controls. To date, no disease-modifying treatment strategy is available for either epilepsy or AD, reflecting an immediate need for exploring common molecular targets, which can delineate a possible mechanistic link between epilepsy and AD. This review attempts to disentangle the interconnectivity between epilepsy and AD pathogenesis via the crucial contribution of Tau protein. Tau protein is a microtubule-associated protein (MAP) that has been implicated in the pathophysiology of both epilepsy and AD. Hyperphosphorylation of Tau contributes to the different forms of human epilepsy and inhibition of the same exerted seizure inhibitions and altered disease progression in a range of animal models. Moreover, Tau-protein-mediated therapy has demonstrated promising outcomes in experimental models of AD. In this review, we discuss how Tau-related mechanisms might present a link between the cause of seizures in epilepsy and cognitive disruption in AD. Untangling this interconnection might be instrumental in designing novel therapies that can minimize epileptic seizures and cognitive deficits in patients with epilepsy and AD.
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Affiliation(s)
- Yam Nath Paudel
- Neuropharmacology Research Laboratory, Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Bandar Sunway, Selangor 46150, Malaysia
| | - Efthalia Angelopoulou
- Department of Biological Chemistry, Medical School, National and Kapodistrian University of Athens, Athens 10679, Greece
| | - Nigel C. Jones
- Department of Neuroscience, Central Clinical School, Monash University, The Alfred Hospital, Melbourne 3800, Australia
- Department of Medicine (Royal Melbourne Hospital), The University of Melbourne, Royal Parade, Parkville, Victoria 3010, Australia
| | - Terence J. O’Brien
- Department of Neuroscience, Central Clinical School, Monash University, The Alfred Hospital, Melbourne 3800, Australia
- Department of Medicine (Royal Melbourne Hospital), The University of Melbourne, Royal Parade, Parkville, Victoria 3010, Australia
| | - Patrick Kwan
- Department of Neuroscience, Central Clinical School, Monash University, The Alfred Hospital, Melbourne 3800, Australia
- Department of Medicine (Royal Melbourne Hospital), The University of Melbourne, Royal Parade, Parkville, Victoria 3010, Australia
| | - Christina Piperi
- Department of Biological Chemistry, Medical School, National and Kapodistrian University of Athens, Athens 10679, Greece
| | - Iekhsan Othman
- Neuropharmacology Research Laboratory, Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Bandar Sunway, Selangor 46150, Malaysia
| | - Mohd. Farooq Shaikh
- Neuropharmacology Research Laboratory, Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Bandar Sunway, Selangor 46150, Malaysia
- Department of Neuroscience, Central Clinical School, Monash University, The Alfred Hospital, Melbourne 3800, Australia
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