1
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Alhadidy MM, Kanaan NM. Biochemical approaches to assess the impact of post-translational modifications on pathogenic tau conformations using recombinant protein. Biochem Soc Trans 2024; 52:301-318. [PMID: 38348781 PMCID: PMC10903483 DOI: 10.1042/bst20230596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Revised: 01/24/2024] [Accepted: 01/26/2024] [Indexed: 02/29/2024]
Abstract
Tau protein is associated with many neurodegenerative disorders known as tauopathies. Aggregates of tau are thought of as a main contributor to neurodegeneration in these diseases. Increasingly, evidence points to earlier, soluble conformations of abnormally modified monomers and multimeric tau as toxic forms of tau. The biological processes driving tau from physiological species to pathogenic conformations remain poorly understood, but certain avenues are currently under investigation including the functional consequences of various pathological tau changes (e.g. mutations, post-translational modifications (PTMs), and protein-protein interactions). PTMs can regulate several aspects of tau biology such as proteasomal and autophagic clearance, solubility, and aggregation. Moreover, PTMs can contribute to the transition of tau from normal to pathogenic conformations. However, our understating of how PTMs specifically regulate the transition of tau into pathogenic conformations is partly impeded by the relative lack of structured frameworks to assess and quantify these conformations. In this review, we describe a set of approaches that includes several in vitro assays to determine the contribution of PTMs to tau's transition into known pathogenic conformations. The approaches begin with different methods to create recombinant tau proteins carrying specific PTMs followed by validation of the PTMs status. Then, we describe a set of biochemical and biophysical assays that assess the contribution of a given PTM to different tau conformations, including aggregation, oligomerization, exposure of the phosphatase-activating domain, and seeding. Together, these approaches can facilitate the advancement of our understanding of the relationships between PTMs and tau conformations.
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Affiliation(s)
- Mohammed M. Alhadidy
- Department of Translational Neuroscience, College of Human Medicine, Michigan State University, Grand Rapids, MI, U.S.A
- Neuroscience Program, Michigan State University, East Lansing, MI, U.S.A
| | - Nicholas M. Kanaan
- Department of Translational Neuroscience, College of Human Medicine, Michigan State University, Grand Rapids, MI, U.S.A
- Neuroscience Program, Michigan State University, East Lansing, MI, U.S.A
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2
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Mahady L, Perez SE, Malek-Ahmadi M, Mufson EJ. Oligomeric, phosphorylated, and truncated tau and spliceosome pathology within the entorhinal-hippocampal connectome across stages of Alzheimer's disease. J Comp Neurol 2023; 531:2080-2108. [PMID: 36989381 PMCID: PMC10539478 DOI: 10.1002/cne.25466] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Revised: 01/27/2023] [Accepted: 02/06/2023] [Indexed: 03/31/2023]
Abstract
Neurofibrillary tangles (NFTs) contain abnormally phosphorylated tau proteins, which spread within components of the medial temporal lobe (MTL) memory circuit in Alzheimer's disease (AD). Here, we used quantitative immunohistochemistry to determine the density of posttranslational oligomeric (TOC1 and TNT1), phosphorylated (AT8), and late truncated (TauC3) tau epitopes within the MTL subfields including entorhinal cortex (EC) layer II, subiculum, Cornu Ammonis (CA) subfields, and dentate gyrus (DG) in subjects who died with a clinical diagnosis of no cognitive impairment (NCI), mild cognitive impairment (MCI), and AD. We also examined whether alterations of the nuclear alternative splicing protein, SRSF2, are associated with tau pathology. Although a significant increase in TOC1, TNT1, and AT8 neuron density occurred in the EC in MCI and AD, subicular, DG granule cell, and CA1 and CA3 densities were only significantly higher in AD. TauC3 counts were not different between connectome regions and clinical groups. SRSF2 intensity in AT8-positive cells decreased significantly in all regions independent of the clinical groups examined. CA1 and subicular AT8, TauC3, and oligomeric densities correlated across clinical groups. EC AT8 counts correlated with CA subfields and subicular and DG values across clinical groups. Oligomeric and AT8 CA1, EC, and subicular density correlated with Braak stage. Decreased nuclear SRSF2 in the presence of cytoplasmic phosphorylated tau suggests a dual-hit process in NFT formation within the entorhinal hippocampal connectome during the onset of AD. Although oligomeric and phosphorylated tau follow a stereotypical pattern, clinical disease stage determined density of tau deposition and not anatomic location within the entorhinal-hippocampal connectome.
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Affiliation(s)
- Laura Mahady
- Dept. of Translational Neuroscience, Phoenix, AZ
| | | | | | - Elliott J. Mufson
- Dept. of Translational Neuroscience, Phoenix, AZ
- Dept. of Neurology, Barrow Neurological Institute, Phoenix, AZ 85013
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3
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Bhargava S, Kulkarni R, Dewangan B, Kulkarni N, Jiaswar C, Kumar K, Kumar A, Bodhe PR, Kumar H, Sahu B. Microtubule stabilising peptides: new paradigm towards management of neuronal disorders. RSC Med Chem 2023; 14:2192-2205. [PMID: 37974959 PMCID: PMC10650357 DOI: 10.1039/d3md00012e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Accepted: 08/09/2023] [Indexed: 11/19/2023] Open
Abstract
Neuronal cells made of soma, axon, and dendrites are highly compartmentalized and possess a specialized transport system that can convey long-distance electrical signals for the cross-talk. The transport system is made up of microtubule (MT) polymers and MT-binding proteins. MTs play vital and diverse roles in various cellular processes. Therefore, defects and dysregulation of MTs and their binding proteins lead to many neurological disorders as exemplified by Parkinson's disease, Alzheimer's disease, amyotrophic lateral sclerosis, Huntington's disease, and many others. MT-stabilising agents (MSAs) altering the MT-associated protein connections have shown great potential for several neurodegenerative disorders. Peptides are an important class of molecules with high specificity, biocompatibility and are devoid of side effects. In the past, peptides have been explored in various neuronal disorders as therapeutics. Davunetide, a MT-stabilising octapeptide, has entered into phase II clinical trials for schizophrenia. Numerous examples of peptides emerging as MSAs reflect the emergence of a new paradigm for peptides which can be explored further as drug candidates for neuronal disorders. Although small molecule-based MSAs have been reviewed in the past, there is no systematic review in recent years focusing on peptides as MSAs apart from davunetide in 2013. Therefore, a systematic updated review on MT stabilising peptides may shed light on many hidden aspects and enable researchers to develop new therapies for diseases related to the CNS. In this review we have summarised the recent examples of peptides as MSAs.
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Affiliation(s)
- Shubhangi Bhargava
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research Ahmedabad India
| | - Riya Kulkarni
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research Ahmedabad India
| | - Bhaskar Dewangan
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research Ahmedabad India
| | - Neeraj Kulkarni
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research Ahmedabad India
| | - Chirag Jiaswar
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research Ahmedabad India
| | - Kunal Kumar
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research Ahmedabad India
| | - Amit Kumar
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research Ahmedabad India
| | - Praveen Reddy Bodhe
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research Ahmedabad India
| | - Hemant Kumar
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research Ahmedabad India
| | - Bichismita Sahu
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research Ahmedabad India
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4
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Cario A, Berger CL. Tau, microtubule dynamics, and axonal transport: New paradigms for neurodegenerative disease. Bioessays 2023; 45:e2200138. [PMID: 37489532 PMCID: PMC10630968 DOI: 10.1002/bies.202200138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Revised: 05/04/2023] [Accepted: 05/23/2023] [Indexed: 07/26/2023]
Abstract
The etiology of Tauopathies, a diverse class of neurodegenerative diseases associated with the Microtubule Associated Protein (MAP) Tau, is usually described by a common mechanism in which Tau dysfunction results in the loss of axonal microtubule stability. Here, we reexamine and build upon the canonical disease model to encompass other Tau functions. In addition to regulating microtubule dynamics, Tau acts as a modulator of motor proteins, a signaling hub, and a scaffolding protein. This diverse array of functions is related to the dynamic nature of Tau isoform expression, post-translational modification (PTM), and conformational flexibility. Thus, there is no single mechanism that can describe Tau dysfunction. The effects of specific pathogenic mutations or aberrant PTMs need to be examined on all of the various functions of Tau in order to understand the unique etiology of each disease state.
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Affiliation(s)
- Alisa Cario
- Department of Molecular Physiology and Biophysics, University of Vermont, Burlington, VT 05405
| | - Christopher L. Berger
- Department of Molecular Physiology and Biophysics, University of Vermont, Burlington, VT 05405
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5
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Desai AA, Zupancic JM, Trzeciakiewicz H, Gerson JE, DuBois KN, Skinner ME, Sharkey LM, McArthur N, Ferris SP, Bhatt NN, Makowski EK, Smith MD, Chen H, Huang J, Jerez C, Kane RS, Kanaan NM, Paulson HL, Tessier PM. Flow cytometric isolation of drug-like conformational antibodies specific for amyloid fibrils. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.04.547698. [PMID: 37461643 PMCID: PMC10349928 DOI: 10.1101/2023.07.04.547698] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/26/2023]
Abstract
Antibodies that recognize specific protein conformational states are broadly important for research, diagnostic and therapeutic applications, yet they are difficult to generate in a predictable and systematic manner using either immunization or in vitro antibody display methods. This problem is particularly severe for conformational antibodies that recognize insoluble antigens such as amyloid fibrils associated with many neurodegenerative disorders. Here we report a quantitative fluorescence-activated cell sorting (FACS) method for directly selecting high-quality conformational antibodies against different types of insoluble (amyloid fibril) antigens using a single, off-the-shelf human library. Our approach uses quantum dots functionalized with antibodies to capture insoluble antigens, and the resulting quantum dot conjugates are used in a similar manner as conventional soluble antigens for multi-parameter FACS selections. Notably, we find that this approach is robust for isolating high-quality conformational antibodies against tau and α-synuclein fibrils from the same human library with combinations of high affinity, high conformational specificity and, in some cases, low off-target binding that rival or exceed those of clinical-stage antibodies specific for tau (zagotenemab) and α-synuclein (cinpanemab). This approach is expected to enable conformational antibody selection and engineering against diverse types of protein aggregates and other insoluble antigens (e.g., membrane proteins) that are compatible with presentation on the surface of antibody-functionalized quantum dots.
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6
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Christensen KR, Combs B, Richards C, Grabinski T, Alhadidy MM, Kanaan NM. Phosphomimetics at Ser199/Ser202/Thr205 in Tau Impairs Axonal Transport in Rat Hippocampal Neurons. Mol Neurobiol 2023; 60:3423-3438. [PMID: 36859689 PMCID: PMC10122714 DOI: 10.1007/s12035-023-03281-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Accepted: 02/16/2023] [Indexed: 03/03/2023]
Abstract
Our understanding of the biological functions of the tau protein now includes its role as a scaffolding protein involved in signaling regulation, which also has implications for tau-mediated dysfunction and degeneration in Alzheimer's disease and other tauopathies. Recently, we found that pseudophosphorylation at sites linked to the pathology-associated AT8 phosphoepitope of tau disrupts normal fast axonal transport through a protein phosphatase 1 (PP1)-dependent pathway in squid axoplasm. Activation of the pathway and the resulting transport deficits required tau's N-terminal phosphatase-activating domain (PAD) and PP1 but the connection between tau and PP1 was not well defined. Here, we studied functional interactions between tau and PP1 isoforms and their effects on axonal transport in mammalian neurons. First, we found that wild-type tau interacted with PP1α and PP1γ primarily through its microtubule-binding repeat domain. Pseudophosphorylation of tau at S199/S202/T205 (psTau) increased PAD exposure, enhanced interactions with PP1γ, and increased active PP1γ levels in mammalian cells. Expression of psTau also significantly impaired axonal transport in primary rat hippocampal neurons. Deletion of PAD in psTau significantly reduced the interaction with PP1γ, eliminated increases of active PP1γ levels, and rescued axonal transport impairment in neurons. These data suggest that a functional consequence of phosphorylation within S199-T205 in tau, which occurs in AD and several other tauopathies, may be aberrant interaction with and activation of PP1γ and subsequent axonal transport disruption in a PAD-dependent fashion.
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Affiliation(s)
- Kyle R Christensen
- Department of Translational Neuroscience, Michigan State University, 400 Monroe Ave NW, Grand Rapids, MI, 49503, USA
- Neuroscience Program, Michigan State University, East Lansing, MI, 48824, USA
| | - Benjamin Combs
- Department of Translational Neuroscience, Michigan State University, 400 Monroe Ave NW, Grand Rapids, MI, 49503, USA
| | - Collin Richards
- Department of Translational Neuroscience, Michigan State University, 400 Monroe Ave NW, Grand Rapids, MI, 49503, USA
| | - Tessa Grabinski
- Department of Translational Neuroscience, Michigan State University, 400 Monroe Ave NW, Grand Rapids, MI, 49503, USA
| | - Mohammed M Alhadidy
- Department of Translational Neuroscience, Michigan State University, 400 Monroe Ave NW, Grand Rapids, MI, 49503, USA
- Neuroscience Program, Michigan State University, East Lansing, MI, 48824, USA
| | - Nicholas M Kanaan
- Department of Translational Neuroscience, Michigan State University, 400 Monroe Ave NW, Grand Rapids, MI, 49503, USA.
- Neuroscience Program, Michigan State University, East Lansing, MI, 48824, USA.
- Hauenstein Neuroscience Center, Mercy Health Saint Mary's, Grand Rapids, MI, 49503, USA.
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7
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Veselkina ER, Trostnikov MV, Roshina NV, Pasyukova EG. The Effect of the Tau Protein on D. melanogaster Lifespan Depends on GSK3 Expression and Sex. Int J Mol Sci 2023; 24:2166. [PMID: 36768490 PMCID: PMC9916465 DOI: 10.3390/ijms24032166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Revised: 01/16/2023] [Accepted: 01/18/2023] [Indexed: 01/25/2023] Open
Abstract
The microtubule-associated conserved protein tau has attracted significant attention because of its essential role in the formation of pathological changes in the nervous system, which can reduce longevity. The study of the effects caused by tau dysfunction and the molecular mechanisms underlying them is complicated because different forms of tau exist in humans and model organisms, and the changes in protein expression can be multidirectional. In this article, we show that an increase in the expression of the main isoform of the Drosophila melanogaster tau protein in the nervous system has differing effects on lifespan depending on the sex of individuals but has no effect on the properties of the nervous system, in particular, the synaptic activity and distribution of another microtubule-associated protein, Futsch, in neuromuscular junctions. Reduced expression of tau in the nervous system does not affect the lifespan of wild-type flies, but it does increase the lifespan dramatically shortened by overexpression of the shaggy gene encoding the GSK3 (Glycogen Synthase Kinase 3) protein kinase, which is one of the key regulators of tau phosphorylation levels. This effect is accompanied by the normalization of the Futsch protein distribution impaired by shaggy overexpression. The results presented in this article demonstrate that multidirectional changes in tau expression can lead to effects that depend on the sex of individuals and the expression level of GSK3.
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Affiliation(s)
- Ekaterina R. Veselkina
- Institute of Molecular Genetics, National Research Centre “Kurchatov Institute”, 123182 Moscow, Russia
| | - Mikhail V. Trostnikov
- Institute of Molecular Genetics, National Research Centre “Kurchatov Institute”, 123182 Moscow, Russia
- Skolkovo Institute of Science and Technology, 121205 Moscow, Russia
| | - Natalia V. Roshina
- Institute of Molecular Genetics, National Research Centre “Kurchatov Institute”, 123182 Moscow, Russia
- Vavilov Institute of General Genetics, Russian Academy of Sciences, 119991 Moscow, Russia
| | - Elena G. Pasyukova
- Institute of Molecular Genetics, National Research Centre “Kurchatov Institute”, 123182 Moscow, Russia
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8
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Balabanian L, Lessard DV, Swaminathan K, Yaninska P, Sébastien M, Wang S, Stevens PW, Wiseman PW, Berger CL, Hendricks AG. Tau differentially regulates the transport of early endosomes and lysosomes. Mol Biol Cell 2022; 33:ar128. [PMID: 36129768 PMCID: PMC9634973 DOI: 10.1091/mbc.e22-01-0018] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Microtubule-associated proteins (MAPs) modulate the motility of kinesin and dynein along microtubules to control the transport of vesicles and organelles. The neuronal MAP tau inhibits kinesin-dependent transport. Phosphorylation of tau at Tyr-18 by fyn kinase results in weakened inhibition of kinesin-1. We examined the motility of early endosomes and lysosomes in cells expressing wild-type (WT) tau and phosphomimetic Y18E tau. We quantified the effects on motility as a function of the tau expression level. Lysosome motility is strongly inhibited by tau. Y18E tau preferentially inhibits lysosomes in the cell periphery, while centrally located lysosomes are less affected. Early endosomes are more sensitive to tau than lysosomes and are inhibited by both WT and Y18E tau. Our results show that different cargoes have disparate responses to tau, likely governed by the types of kinesin motors driving their transport. In support of this model, kinesin-1 and -3 are strongly inhibited by tau while kinesin-2 and dynein are less affected. In contrast to kinesin-1, we find that kinesin-3 is strongly inhibited by phosphorylated tau.
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Affiliation(s)
- Linda Balabanian
- Departments of Bioengineering, McGill University, Montreal, QC H3A 0E9, Canada
| | - Dominique V. Lessard
- Department of Molecular Physiology and Biophysics, University of Vermont, Burlington, VT 05405
| | | | - Pamela Yaninska
- Chemistry and Physics, McGill University, Montreal, QC H3A 0E9, Canada
| | - Muriel Sébastien
- Departments of Bioengineering, McGill University, Montreal, QC H3A 0E9, Canada
| | - Samuel Wang
- Departments of Bioengineering, McGill University, Montreal, QC H3A 0E9, Canada
| | - Piper W. Stevens
- Departments of Bioengineering, McGill University, Montreal, QC H3A 0E9, Canada
| | - Paul W. Wiseman
- Chemistry and Physics, McGill University, Montreal, QC H3A 0E9, Canada
| | - Christopher L. Berger
- Department of Molecular Physiology and Biophysics, University of Vermont, Burlington, VT 05405
| | - Adam G. Hendricks
- Departments of Bioengineering, McGill University, Montreal, QC H3A 0E9, Canada,*Address correspondence to: Adam G. Hendricks ()
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9
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Immunogenicity of MultiTEP platform technology-based Tau vaccine in non-human primates. NPJ Vaccines 2022; 7:117. [PMID: 36224191 PMCID: PMC9556597 DOI: 10.1038/s41541-022-00544-3] [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: 05/26/2022] [Accepted: 09/22/2022] [Indexed: 11/09/2022] Open
Abstract
Pathological forms of Tau protein are directly associated with neurodegeneration and correlate with Alzheimer’s Disease (AD) symptoms, progression, and severity. Previously, using various mouse models of Tauopathies and AD, we have demonstrated the immunogenicity and efficacy of the MultiTEP-based adjuvanted vaccine targeting the phosphatase activating domain (PAD) of Tau, AV-1980R/A. Here, we analyzed its immunogenicity in non-human primates (NHP), the closest phylogenic relatives to humans with a similar immune system, to initiate the transition of this vaccine into clinical trials. We have demonstrated that AV-1980R/A is highly immunogenic in these NHPs, activating a broad but unique to each monkey repertoire of MultiTEP-specific T helper (Th) cells that, in turn, activate B cells specific to PAD. The resulting anti-PAD IgG antibodies recognize pathological Tau tangles and Tau-positive neuritis in AD case brain sections with no staining in control non-AD cases. These published data and efficacy results support the AV-1980R/A vaccine progression to first-in-human clinical trials.
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10
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The ubiquitous microtubule-associated protein 4 (MAP4) controls organelle distribution by regulating the activity of the kinesin motor. Proc Natl Acad Sci U S A 2022; 119:e2206677119. [PMID: 36191197 PMCID: PMC9565364 DOI: 10.1073/pnas.2206677119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Regulation of organelle transport by molecular motors along the cytoskeletal microtubules is central to maintaining cellular functions. Here, we show that the ubiquitous tau-related microtubule-associated protein 4 (MAP4) can bias the bidirectional transport of organelles toward the microtubule minus-ends. This is concurrent with MAP4 phosphorylation, mediated by the kinase GSK3β. We demonstrate that MAP4 achieves this bias by tethering the cargo to the microtubules, allowing it to impair the force generation of the plus-end motor kinesin-1. Consistent with this mechanism, MAP4 physically interacts with dynein and dynactin and, when phosphorylated, associates with the cargo-motor complex through its projection domain. Its phosphorylation coincides with the perinuclear accumulation of organelles, a phenotype that is rescued by abolishing the cargo-microtubule MAP4 tether or by the pharmacological inhibition of dynein, confirming the ability of kinesin to inch along, albeit inefficiently, in the presence of phosphorylated MAP4. These findings have broad biological significance because of the ubiquity of MAP4 and the involvement of GSK3β in multiple diseases, more specifically in cancer, where the MAP4-dependent redistribution of organelles may be prevalent in cancer cells, as we demonstrate here for mitochondria in lung carcinoma epithelial cells.
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11
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Cario A, Wickramasinghe SP, Rhoades E, Berger CL. The N-terminal disease-associated R5L Tau mutation increases microtubule shrinkage rate due to disruption of microtubule-bound Tau patches. J Biol Chem 2022; 298:102526. [PMID: 36162501 PMCID: PMC9589210 DOI: 10.1016/j.jbc.2022.102526] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Revised: 09/07/2022] [Accepted: 09/08/2022] [Indexed: 11/25/2022] Open
Abstract
Regulation of the neuronal microtubule cytoskeleton is achieved through the coordination of microtubule-associated proteins (MAPs). MAP-Tau, the most abundant MAP in the axon, functions to modulate motor motility, participate in signaling cascades, as well as directly mediate microtubule dynamics. Tau misregulation is associated with a class of neurodegenerative diseases, known as tauopathies, including progressive supranuclear palsy, Pick's disease, and Alzheimer's disease. Many disease-associated mutations in Tau are found in the C-terminal microtubule-binding domain. These mutations decrease microtubule-binding affinity and are proposed to reduce microtubule stability, leading to disease. N-terminal disease-associated mutations also exist, but the mechanistic details of their downstream effects are not as clear. Here, we investigate the effect of the progressive supranuclear palsy–associated N-terminal R5L mutation on Tau-mediated microtubule dynamics using an in vitro reconstituted system. We show that the R5L mutation does not alter Tau interactions with tubulin by fluorescence correlation spectroscopy. Using total internal reflection fluorescence microscopy, we determined that the R5L mutation has no effect on microtubule growth rate, catastrophe frequency, or rescue frequency. Rather, the R5L mutation increases microtubule shrinkage rate. We determine this is due to disruption of Tau patches, larger order Tau complexes known to form on the GDP-microtubule lattice. Altogether, these results provide insight into the role of Tau patches in mediating microtubule dynamics and suggesting a novel mechanism by which mutations in the N-terminal projection domain reduce microtubule stability.
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Affiliation(s)
- Alisa Cario
- Department of Molecular Physiology and Biophysics, University of Vermont, Burlington, VT 05405
| | - Sanjula P Wickramasinghe
- Biochemistry and Molecular Biophysics Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Elizabeth Rhoades
- Biochemistry and Molecular Biophysics Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania; Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Christopher L Berger
- Department of Molecular Physiology and Biophysics, University of Vermont, Burlington, VT 05405.
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12
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Saroja SR, Sharma A, Hof PR, Pereira AC. Differential expression of tau species and the association with cognitive decline and synaptic loss in Alzheimer's disease. Alzheimers Dement 2022; 18:1602-1615. [PMID: 34873815 PMCID: PMC9170833 DOI: 10.1002/alz.12518] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 10/03/2021] [Accepted: 10/13/2021] [Indexed: 01/24/2023]
Abstract
Pathological tau proteins in patients with Alzheimer's disease (AD) mainly accumulate in the form of neurofibrillary tangles (NFTs) and neuritic plaques (NPs). However, the molecular properties of tau species present in NFTs and NPs are not known. We tested the hypothesis that tau species within NFT-predominant tissue (NFT_AD) are distinct and more toxic than those in NP-predominant tissue (NP_AD). We analyzed the tau species from post mortem prefrontal cortical brains of NFT_AD and NP_AD. Compared to NP_AD, NFT_AD displayed highly phosphorylated tau oligomers, possessed tau oligomers in extracellular vesicles, and the 3-repeat (3R) and 4-repeat (4R) isoforms were differentially expressed between the groups. Comparison of tau proteins isolated from NFT- versus NP-AD subjects demonstrated higher tau seeding activity in NFT subjects and a greater degree of inducing synaptic loss in cultured neurons. We propose that tau species from NFT-predominant tissues possess greater levels of degenerative properties, thereby causing synaptic loss and cognitive decline.
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Affiliation(s)
- Sivaprakasam R. Saroja
- Department of Neurology, Icahn School of MedicineMount SinaiNew YorkNew YorkUSA
- Nash Family Department of Neuroscience and Friedman Brain InstituteIcahn School of Medicine at Mount SinaiNew YorkNew YorkUSA
| | - Abhijeet Sharma
- Department of Neurology, Icahn School of MedicineMount SinaiNew YorkNew YorkUSA
- Nash Family Department of Neuroscience and Friedman Brain InstituteIcahn School of Medicine at Mount SinaiNew YorkNew YorkUSA
| | - Patrick R. Hof
- Nash Family Department of Neuroscience and Friedman Brain InstituteIcahn School of Medicine at Mount SinaiNew YorkNew YorkUSA
- Ronald M. Loeb Center for Alzheimer's DiseaseIcahn School of Medicine at Mount SinaiNew YorkNew YorkUSA
| | - Ana C. Pereira
- Department of Neurology, Icahn School of MedicineMount SinaiNew YorkNew YorkUSA
- Nash Family Department of Neuroscience and Friedman Brain InstituteIcahn School of Medicine at Mount SinaiNew YorkNew YorkUSA
- Ronald M. Loeb Center for Alzheimer's DiseaseIcahn School of Medicine at Mount SinaiNew YorkNew YorkUSA
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13
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The pathogenic R5L mutation disrupts formation of Tau complexes on the microtubule by altering local N-terminal structure. Proc Natl Acad Sci U S A 2022; 119:2114215119. [PMID: 35135879 PMCID: PMC8851524 DOI: 10.1073/pnas.2114215119] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/27/2021] [Indexed: 11/21/2022] Open
Abstract
The microtubule-associated protein (MAP) Tau is an intrinsically disordered protein (IDP) primarily expressed in axons, where it functions to regulate microtubule dynamics, modulate motor protein motility, and participate in signaling cascades. Tau misregulation and point mutations are linked to neurodegenerative diseases, including progressive supranuclear palsy (PSP), Pick's disease, and Alzheimer's disease. Many disease-associated mutations in Tau occur in the C-terminal microtubule-binding domain of the protein. Effects of C-terminal mutations in Tau have led to the widely accepted disease-state theory that missense mutations in Tau reduce microtubule-binding affinity or increase Tau propensity to aggregate. Here, we investigate the effect of an N-terminal arginine to leucine mutation at position 5 in Tau (R5L), associated with PSP, on Tau-microtubule interactions using an in vitro reconstituted system. Contrary to the canonical disease-state theory, we determine that the R5L mutation does not reduce Tau affinity for the microtubule using total internal reflection fluorescence microscopy. Rather, the R5L mutation decreases the ability of Tau to form larger-order complexes, or Tau patches, at high concentrations of Tau. Using NMR, we show that the R5L mutation results in a local structural change that reduces interactions of the projection domain in the presence of microtubules. Altogether, these results challenge both the current paradigm of how mutations in Tau lead to disease and the role of the projection domain in modulating Tau behavior on the microtubule surface.
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Morris SL, Brady ST. Tau phosphorylation and PAD exposure in regulation of axonal growth. Front Cell Dev Biol 2022; 10:1023418. [PMID: 36742197 PMCID: PMC9893789 DOI: 10.3389/fcell.2022.1023418] [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: 08/19/2022] [Accepted: 12/23/2022] [Indexed: 01/20/2023] Open
Abstract
Introduction: Tau is a microtubule associated phosphoprotein found principally in neurons. Prevailing dogma continues to define microtubule stabilization as the major function of tau in vivo, despite several lines of evidence suggesting this is not the case. Most importantly, tau null mice have deficits in axonal outgrowth and neuronal migration while still possessing an extensive microtubule network. Instead, mounting evidence suggests that tau may have a major function in the regulation of fast axonal transport (FAT) through activation of neuronal signaling pathways. Previous studies identified a phosphatase activating domain (PAD) at the tau N-terminal that is normally sequestered, but is constitutively exposed in tauopathies. When exposed, the PAD activates a signaling cascade involving PP1 and GSK3β which affects cellular functions including release of cargo from kinesin. Furthermore, we discovered that PAD exposure can be regulated by a single phosphorylation at T205. Exposure of the PAD is an early event in multiple tauopathies and a major contributing factor to neurodegeneration associated with tau hyperphosphorylation. However, effects of tau PAD exposure on anterograde FAT raised the interesting possibility that this pathway may be a mechanism for physiological regulation of cargo delivery through site-specific phosphorylation of tau and transient activation of PP1 and GSK3β. Significantly, there is already evidence of local control of PP1 and GSK3β at sites which require cargo delivery. Methods: To investigate this hypothesis, first we evaluated cellular localization of tau PAD exposure, pT205 tau phosphorylation, and active GSK3β in primary hippocampal neurons during development. Second, we analyzed the axonal outgrowth of tau knockout neurons following transfection with full length hTau40-WT, hTau40-ΔPAD, or hTau40-T205A. Results and Discussion: The results presented here suggest that transient activation of a PP1-GSK3β signaling pathway through locally regulated PAD exposure is a mechanism for cargo delivery, and thereby important for neurite outgrowth of developing neurons.
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Affiliation(s)
- S L Morris
- Department of Anatomy and Cell Biology, University of Illinois at Chicago, Chicago, IL, United States
| | - S T Brady
- Department of Anatomy and Cell Biology, University of Illinois at Chicago, Chicago, IL, United States
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15
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Frontotemporal Lobar Dementia Mutant Tau Impairs Axonal Transport through a Protein Phosphatase 1γ-Dependent Mechanism. J Neurosci 2021; 41:9431-9451. [PMID: 34607969 PMCID: PMC8580143 DOI: 10.1523/jneurosci.1914-20.2021] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 08/19/2021] [Accepted: 08/21/2021] [Indexed: 11/21/2022] Open
Abstract
Pathologic tau modifications are characteristic of Alzheimer's disease and related dementias, but mechanisms of tau toxicity continue to be debated. Inherited mutations in tau cause early onset frontotemporal lobar dementias (FTLD-tau) and are commonly used to model mechanisms of tau toxicity in tauopathies. Previous work in the isolated squid axoplasm model demonstrated that several pathogenic forms of tau inhibit axonal transport through a mechanism involving activation of protein phosphatase 1 (PP1). Here, we determined that P301L and R5L FTLD mutant tau proteins elicit a toxic effect on axonal transport as monomeric proteins. We evaluated interactions of wild-type or mutant tau with specific PP1 isoforms (α, β, and γ) to examine how the interaction contributes to this toxic effect using primary rat hippocampal neurons from both sexes. Pull-down and bioluminescence resonance energy transfer experiments revealed selective interactions of wild-type tau with PP1α and PP1γ isoforms, but not PP1β, which were significantly increased by the P301L tau mutation. The results from proximity ligation assays confirmed the interaction in primary hippocampal neurons. Moreover, expression of FTLD-linked mutant tau in these neurons enhanced levels of active PP1, also increasing the pausing frequency of fluorescently labeled vesicles in both anterograde and retrograde directions. Knockdown of PP1γ, but not PP1α, rescued the cargo-pausing effects of P301L and R5L tau, a result replicated by deleting a phosphatase-activating domain in the amino terminus of P301L tau. These findings support a model of tau toxicity involving aberrant activation of a specific PP1γ-dependent pathway that disrupts axonal transport in neurons. SIGNIFICANCE STATEMENT Tau pathology is closely associated with neurodegeneration in Alzheimer's disease and other tauopathies, but the toxic mechanisms remain a debated topic. We previously proposed that pathologic tau forms induce dysfunction and degeneration through aberrant activation of a PP1-dependent pathway that disrupts axonal transport. Here, we show that tau directly interacts with specific PP1 isoforms, increasing levels of active PP1. Pathogenic tau mutations enhance this interaction, further increasing active PP1 levels and impairing axonal transport in isolated squid axoplasm and primary hippocampal neurons. Mutant-tau-mediated impairment of axonal transport was mediated by PP1γ and a phosphatase-activating domain located at the amino terminus of tau. This work has important implications for understanding and potentially mitigating tau-mediated neurotoxicity in tauopathies.
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Sinsky J, Pichlerova K, Hanes J. Tau Protein Interaction Partners and Their Roles in Alzheimer's Disease and Other Tauopathies. Int J Mol Sci 2021; 22:9207. [PMID: 34502116 PMCID: PMC8431036 DOI: 10.3390/ijms22179207] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 08/23/2021] [Accepted: 08/25/2021] [Indexed: 02/06/2023] Open
Abstract
Tau protein plays a critical role in the assembly, stabilization, and modulation of microtubules, which are important for the normal function of neurons and the brain. In diseased conditions, several pathological modifications of tau protein manifest. These changes lead to tau protein aggregation and the formation of paired helical filaments (PHF) and neurofibrillary tangles (NFT), which are common hallmarks of Alzheimer's disease and other tauopathies. The accumulation of PHFs and NFTs results in impairment of physiological functions, apoptosis, and neuronal loss, which is reflected as cognitive impairment, and in the late stages of the disease, leads to death. The causes of this pathological transformation of tau protein haven't been fully understood yet. In both physiological and pathological conditions, tau interacts with several proteins which maintain their proper function or can participate in their pathological modifications. Interaction partners of tau protein and associated molecular pathways can either initiate and drive the tau pathology or can act neuroprotective, by reducing pathological tau proteins or inflammation. In this review, we focus on the tau as a multifunctional protein and its known interacting partners active in regulations of different processes and the roles of these proteins in Alzheimer's disease and tauopathies.
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Affiliation(s)
| | | | - Jozef Hanes
- Institute of Neuroimmunology, Slovak Academy of Sciences, Dubravska Cesta 9, 845 10 Bratislava, Slovakia; (J.S.); (K.P.)
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17
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Rai SK, Savastano A, Singh P, Mukhopadhyay S, Zweckstetter M. Liquid-liquid phase separation of tau: From molecular biophysics to physiology and disease. Protein Sci 2021; 30:1294-1314. [PMID: 33930220 PMCID: PMC8197432 DOI: 10.1002/pro.4093] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Revised: 04/24/2021] [Accepted: 04/27/2021] [Indexed: 12/14/2022]
Abstract
Biomolecular condensation via liquid-liquid phase separation (LLPS) of intrinsically disordered proteins/regions (IDPs/IDRs), with and without nucleic acids, has drawn widespread interest due to the rapidly unfolding role of phase-separated condensates in a diverse range of cellular functions and human diseases. Biomolecular condensates form via transient and multivalent intermolecular forces that sequester proteins and nucleic acids into liquid-like membrane-less compartments. However, aberrant phase transitions into gel-like or solid-like aggregates might play an important role in neurodegenerative and other diseases. Tau, a microtubule-associated neuronal IDP, is involved in microtubule stabilization, regulates axonal outgrowth and transport in neurons. A growing body of evidence indicates that tau can accomplish some of its cellular activities via LLPS. However, liquid-to-solid transition resulting in the abnormal aggregation of tau is associated with neurodegenerative diseases. The physical chemistry of tau is crucial for governing its propensity for biomolecular condensation which is governed by various intermolecular and intramolecular interactions leading to simple one-component and complex multi-component condensates. In this review, we aim at capturing the current scientific state in unveiling the intriguing molecular mechanism of phase separation of tau. We particularly focus on the amalgamation of existing and emerging biophysical tools that offer unique spatiotemporal resolutions on a wide range of length- and time-scales. We also discuss the link between quantitative biophysical measurements and novel biological insights into biomolecular condensation of tau. We believe that this account will provide a broad and multidisciplinary view of phase separation of tau and its association with physiology and disease.
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Affiliation(s)
- Sandeep K. Rai
- Centre for Protein Science, Design and Engineering, Department of Biological Sciences, and Department of Chemical SciencesIndian Institute of Science Education and Research (IISER)MohaliIndia
| | - Adriana Savastano
- Research group Translational Structural BiologyGerman Center for Neurodegenerative Diseases (DZNE)GöttingenGermany
| | - Priyanka Singh
- Centre for Protein Science, Design and Engineering, Department of Biological Sciences, and Department of Chemical SciencesIndian Institute of Science Education and Research (IISER)MohaliIndia
| | - Samrat Mukhopadhyay
- Centre for Protein Science, Design and Engineering, Department of Biological Sciences, and Department of Chemical SciencesIndian Institute of Science Education and Research (IISER)MohaliIndia
| | - Markus Zweckstetter
- Research group Translational Structural BiologyGerman Center for Neurodegenerative Diseases (DZNE)GöttingenGermany
- Department for NMR‐based Structural BiologyMax Planck Institute for Biophysical ChemistryGöttingenGermany
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18
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Xia Y, Prokop S, Giasson BI. "Don't Phos Over Tau": recent developments in clinical biomarkers and therapies targeting tau phosphorylation in Alzheimer's disease and other tauopathies. Mol Neurodegener 2021; 16:37. [PMID: 34090488 PMCID: PMC8180161 DOI: 10.1186/s13024-021-00460-5] [Citation(s) in RCA: 78] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Accepted: 05/26/2021] [Indexed: 12/11/2022] Open
Abstract
Phosphorylation is one of the most prevalent post-translational modifications found in aggregated tau isolated from Alzheimer’s disease (AD) patient brains. In tauopathies like AD, increased phosphorylation or hyperphosphorylation can contribute to microtubule dysfunction and is associated with tau aggregation. In this review, we provide an overview of the structure and functions of tau protein as well as the physiologic roles of tau phosphorylation. We also extensively survey tau phosphorylation sites identified in brain tissue and cerebrospinal fluid from AD patients compared to age-matched healthy controls, which may serve as disease-specific biomarkers. Recently, new assays have been developed to measure minute amounts of specific forms of phosphorylated tau in both cerebrospinal fluid and plasma, which could potentially be useful for aiding clinical diagnosis and monitoring disease progression. Additionally, multiple therapies targeting phosphorylated tau are in various stages of clinical trials including kinase inhibitors, phosphatase activators, and tau immunotherapy. With promising early results, therapies that target phosphorylated tau could be useful at slowing tau hyperphosphorylation and aggregation in AD and other tauopathies.
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Affiliation(s)
- Yuxing Xia
- Department of Neuroscience, College of Medicine, University of Florida, BMS J483/CTRND, 1275 Center Drive, Gainesville, FL, 32610, USA.,Center for Translational Research in Neurodegenerative Disease, College of Medicine, University of Florida, Gainesville, Florida, 32610, USA
| | - Stefan Prokop
- Center for Translational Research in Neurodegenerative Disease, College of Medicine, University of Florida, Gainesville, Florida, 32610, USA.,Department of Pathology, College of Medicine, University of Florida, Gainesville, Florida, 32610, USA.,McKnight Brain Institute, College of Medicine, University of Florida, Gainesville, Florida, 32610, USA
| | - Benoit I Giasson
- Department of Neuroscience, College of Medicine, University of Florida, BMS J483/CTRND, 1275 Center Drive, Gainesville, FL, 32610, USA. .,Center for Translational Research in Neurodegenerative Disease, College of Medicine, University of Florida, Gainesville, Florida, 32610, USA. .,McKnight Brain Institute, College of Medicine, University of Florida, Gainesville, Florida, 32610, USA.
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19
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Wysocka A, Palasz E, Steczkowska M, Niewiadomska G. Dangerous Liaisons: Tau Interaction with Muscarinic Receptors. Curr Alzheimer Res 2021; 17:224-237. [PMID: 32329686 PMCID: PMC7509759 DOI: 10.2174/1567205017666200424134311] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Revised: 02/05/2020] [Accepted: 03/25/2020] [Indexed: 11/22/2022]
Abstract
The molecular processes underlying neurodegenerative diseases (such as Alzheimer's Disease - AD) remain poorly understood. There is also an imperative need for disease-modifying therapies in AD since the present treatments, acetylcholinesterase inhibitors and NMDA antagonists, do not halt its progression. AD and other dementias present unique pathological features such as that of microtubule associated protein tau metabolic regulation. Tau has numerous binding partners, including signaling molecules, cytoskeletal elements and lipids, which suggests that it is a multifunctional protein. AD has also been associated with severe loss of cholinergic markers in the brain and such loss may be due to the toxic interaction of tau with cholinergic muscarinic receptors. By using specific antagonists of muscarinic receptors it was found in vitro that extracellular tau binds to M1 and M3 receptors and which the increase of intracellular calcium found in neuronal cells upon tau-binding. However, so far, the significance of tau signaling through muscarinic receptor in vivo in tauopathic models remains uncertain. The data reviewed in the present paper highlight the significant effect of M1 receptor/tau interaction in exacerbating tauopathy related pathological features and suggest that selective M1 agonists may serve as a prototype for future therapeutic development toward modification of currently intractable neurodegenerative diseases, such as tauopathies.
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Affiliation(s)
- Adrianna Wysocka
- Neurobiology Center, Nencki Institute of Experimental Biology, 02-093 Warsaw, Poland
| | - Ewelina Palasz
- Department of Applied Physiology, Mossakowski Medical Research Center, 02-093 Warsaw, Poland
| | - Marta Steczkowska
- Department of Applied Physiology, Mossakowski Medical Research Center, 02-093 Warsaw, Poland
| | - Grazyna Niewiadomska
- Neurobiology Center, Nencki Institute of Experimental Biology, 02-093 Warsaw, Poland
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20
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Mueller RL, Combs B, Alhadidy MM, Brady ST, Morfini GA, Kanaan NM. Tau: A Signaling Hub Protein. Front Mol Neurosci 2021; 14:647054. [PMID: 33815057 PMCID: PMC8017207 DOI: 10.3389/fnmol.2021.647054] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Accepted: 02/23/2021] [Indexed: 12/23/2022] Open
Abstract
Over four decades ago, in vitro experiments showed that tau protein interacts with and stabilizes microtubules in a phosphorylation-dependent manner. This observation fueled the widespread hypotheses that these properties extend to living neurons and that reduced stability of microtubules represents a major disease-driving event induced by pathological forms of tau in Alzheimer’s disease and other tauopathies. Accordingly, most research efforts to date have addressed this protein as a substrate, focusing on evaluating how specific mutations, phosphorylation, and other post-translational modifications impact its microtubule-binding and stabilizing properties. In contrast, fewer efforts were made to illuminate potential mechanisms linking physiological and disease-related forms of tau to the normal and pathological regulation of kinases and phosphatases. Here, we discuss published work indicating that, through interactions with various kinases and phosphatases, tau may normally act as a scaffolding protein to regulate phosphorylation-based signaling pathways. Expanding on this concept, we also review experimental evidence linking disease-related tau species to the misregulation of these pathways. Collectively, the available evidence supports the participation of tau in multiple cellular processes sustaining neuronal and glial function through various mechanisms involving the scaffolding and regulation of selected kinases and phosphatases at discrete subcellular compartments. The notion that the repertoire of tau functions includes a role as a signaling hub should widen our interpretation of experimental results and increase our understanding of tau biology in normal and disease conditions.
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Affiliation(s)
- Rebecca L Mueller
- Department of Translational Neuroscience, Michigan State University, Grand Rapids, MI, United States.,Neuroscience Program, Michigan State University, East Lansing, MI, United States
| | - Benjamin Combs
- Department of Translational Neuroscience, Michigan State University, Grand Rapids, MI, United States
| | - Mohammed M Alhadidy
- Department of Translational Neuroscience, Michigan State University, Grand Rapids, MI, United States.,Neuroscience Program, Michigan State University, East Lansing, MI, United States
| | - Scott T Brady
- Department of Anatomy and Cell Biology, The University of Illinois at Chicago, Chicago, IL, United States.,Marine Biological Laboratory, Woods Hole, MA, United States
| | - Gerardo A Morfini
- Department of Anatomy and Cell Biology, The University of Illinois at Chicago, Chicago, IL, United States.,Marine Biological Laboratory, Woods Hole, MA, United States
| | - Nicholas M Kanaan
- Department of Translational Neuroscience, Michigan State University, Grand Rapids, MI, United States.,Neuroscience Program, Michigan State University, East Lansing, MI, United States.,Hauenstein Neuroscience Center, Mercy Health Saint Mary's, Grand Rapids, MI, United States
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21
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Characterization of tau binding by gosuranemab. Neurobiol Dis 2020; 146:105120. [DOI: 10.1016/j.nbd.2020.105120] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 09/11/2020] [Accepted: 09/24/2020] [Indexed: 12/15/2022] Open
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22
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Strong MJ, Donison NS, Volkening K. Alterations in Tau Metabolism in ALS and ALS-FTSD. Front Neurol 2020; 11:598907. [PMID: 33329356 PMCID: PMC7719764 DOI: 10.3389/fneur.2020.598907] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Accepted: 10/27/2020] [Indexed: 12/15/2022] Open
Abstract
There is increasing acceptance that amyotrophic lateral sclerosis (ALS), classically considered a neurodegenerative disease affecting almost exclusively motor neurons, is syndromic with both clinical and biological heterogeneity. This is most evident in its association with a broad range of neuropsychological, behavioral, speech and language deficits [collectively termed ALS frontotemporal spectrum disorder (ALS-FTSD)]. Although the most consistent pathology of ALS and ALS-FTSD is a disturbance in TAR DNA binding protein 43 kDa (TDP-43) metabolism, alterations in microtubule-associated tau protein (tau) metabolism can also be observed in ALS-FTSD, most prominently as pathological phosphorylation at Thr175 (pThr175tau). pThr175 has been shown to promote exposure of the phosphatase activating domain (PAD) in the tau N-terminus with the consequent activation of GSK3β mediated phosphorylation at Thr231 (pThr231tau) leading to pathological oligomer formation. This pathological cascade of tau phosphorylation has been observed in chronic traumatic encephalopathy with ALS (CTE-ALS) and in both in vivo and in vitro experimental paradigms, suggesting that it is of critical relevance to the pathobiology of ALS-FTSD. It is also evident that the co-existence of alterations in the metabolism of TDP-43 and tau acts synergistically in a rodent model to exacerbate the pathology of either.
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Affiliation(s)
- Michael J Strong
- Molecular Medicine, Schulich School of Medicine and Dentistry, Robarts Research Institute, Western University, London, ON, Canada.,Department of Clinical Neurological Sciences, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada
| | - Neil S Donison
- Molecular Medicine, Schulich School of Medicine and Dentistry, Robarts Research Institute, Western University, London, ON, Canada.,Neuroscience Graduate Program, Western University, London, ON, Canada
| | - Kathryn Volkening
- Molecular Medicine, Schulich School of Medicine and Dentistry, Robarts Research Institute, Western University, London, ON, Canada.,Department of Clinical Neurological Sciences, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada
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23
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Boumil EF, Vohnoutka RB, Lee S, Shea TB. Tau interferes with axonal neurite stabilization and cytoskeletal composition independently of its ability to associate with microtubules. Biol Open 2020; 9:9/9/bio052530. [PMID: 32978225 PMCID: PMC7522022 DOI: 10.1242/bio.052530] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Tau impacts overall axonal transport particularly when overexpressed by interfering with translocation of kinesin along microtubules (MTs) and/or as a cargo of kinesin by outcompeting other kinesin cargo. To discern between which of these mechanisms was more robust during axonal outgrowth, we overexpressed phosphomimetic (E18; which is incapable of MT binding), phospho-null (A18) or wild-type (WT) full-length human tau conjugated to EGFP, the latter two of which bind MTs. Expression of WT and A18 displayed increased acetylated MTs and resistance to colchicine, while expression of E18 did not, indicating that E18 did not contribute to MT stabilization. Expression of all tau constructs reduced overall levels of neurofilaments (NFs) within axonal neurites, and distribution of NFs along neurite lengths. Since NFs are another prominent cargo of kinesin during axonal neurite outgrowth, this finding is consistent with WT, A18 and E18 inhibiting NF transport to the same extent by competing as cargo of kinesin. These findings indicate that tau can impair axonal transport independently of association with MTs in growing axonal neurites.
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Affiliation(s)
- Edward F Boumil
- Laboratory for Neuroscience, Department of Biological Sciences, UMass Lowell, Lowell, MA 01854, USA
| | - Rishel B Vohnoutka
- Laboratory for Neuroscience, Department of Biological Sciences, UMass Lowell, Lowell, MA 01854, USA
| | - Sangmook Lee
- Laboratory for Neuroscience, Department of Biological Sciences, UMass Lowell, Lowell, MA 01854, USA
| | - Thomas B Shea
- Laboratory for Neuroscience, Department of Biological Sciences, UMass Lowell, Lowell, MA 01854, USA
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24
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Activity-dependent neuroprotective protein (ADNP)-end-binding protein (EB) interactions regulate microtubule dynamics toward protection against tauopathy. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2020; 177:65-90. [PMID: 33453943 DOI: 10.1016/bs.pmbts.2020.07.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The 1102-amino-acid activity-dependent neuroprotective protein (ADNP) was originally discovered by expression cloning through the immunological identification of its 8-amino-acid sequence NAPVSIPQ (NAP), constituting the smallest active neuroprotective fragment of the protein. ADNP expression is essential for brain formation and cognitive function and is dysregulated in a variety of neurodegenerative diseases (Alzheimer's disease, Parkinson's disease, and schizophrenia). ADNP has been found to be mutated in autism, with an estimated prevalence of 0.17% (together, these autism cases now constitute ADNP syndrome cases) and our recent results showed somatic mutations in ADNP in Alzheimer's disease brains correlating with tauopathy. Furthermore, Adnp haploinsufficiency in mice causes an age-dependent reduction in cognitive functions coupled with tauopathy-like features such as an increased formation of tangle-like structures, defective axonal transport, and Tau hyperphosphorylation. ADNP and its derived peptides, NAP and SKIP, directly interact with end-binding proteins (EBs), which decorate plus-tips of the growing axonal cytoskeleton-microtubules (MTs). Functionally, NAP and SKIP are neuroprotective and stimulate axonal transport. Clinical trials have suggested the potential efficacy of NAP (davunetide, CP201) for improving cognitive performance/functional activities of daily living in amnestic mild cognitive impairment (aMCI) and schizophrenia patients, respectively. However, NAP was not found to be an effective treatment (though well-tolerated) for progressive supranuclear palsy (PSP) patients. Here we review the molecular mechanism of NAP activity on MTs and how NAP modulates the MT-Tau-EBs crosstalk. We offer a molecular explanation for the different protective potency of NAP in selected tauopathies (aMCI vs. PSP) expressing different ratios/pathologies of the alternatively spliced Tau mRNA and its resulting protein (aMCI expressing similar quantities of the dynamic Tau 3-MT binding isoform (Tau3R) and the Tau 4-MT binding isoform (Tau4R) and PSP enriched in Tau4R pathology). We reveal the direct effect of truncated ADNPs (resulting from de novo autism and newly discovered Alzheimer's disease-related somatic mutations) on MT dynamics. We show that the peptide SKIP affects MT dynamics and MT-Tau association. Since MT impairment is linked with neurodegenerative and neurodevelopmental conditions, the current study implicates a paucity/dysregulation of MT-interacting endogenous proteins, like ADNP, as a contributing mechanism and provides hope for NAP and SKIP as MT-modulating drug candidates.
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25
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Liquid-liquid phase separation induces pathogenic tau conformations in vitro. Nat Commun 2020; 11:2809. [PMID: 32499559 PMCID: PMC7272632 DOI: 10.1038/s41467-020-16580-3] [Citation(s) in RCA: 143] [Impact Index Per Article: 35.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Accepted: 05/08/2020] [Indexed: 01/21/2023] Open
Abstract
Formation of membrane-less organelles via liquid-liquid phase separation is one way cells meet the biological requirement for spatiotemporal regulation of cellular components and reactions. Recently, tau, a protein known for its involvement in Alzheimer’s disease and other tauopathies, was found to undergo liquid–liquid phase separation making it one of several proteins associated with neurodegenerative diseases to do so. Here, we demonstrate that tau forms dynamic liquid droplets in vitro at physiological protein levels upon molecular crowding in buffers that resemble physiological conditions. Tau droplet formation is significantly enhanced by disease-associated modifications, including the AT8 phospho-epitope and the P301L tau mutation linked to an inherited tauopathy. Moreover, tau droplet dynamics are significantly reduced by these modified forms of tau. Extended phase separation promoted a time-dependent adoption of toxic conformations and oligomerization, but not filamentous aggregation. P301L tau protein showed the greatest oligomer formation following extended phase separation. These findings suggest that phase separation of tau may facilitate the formation of non-filamentous pathogenic tau conformations. Tau plays an important role in tauopathies and undergoes liquid-liquid phase separation (LLPS). The authors show that disease-related P301L mutant and phosphomimic (S199E/S202E/T205E) tau enhance LLPS in vitro at physiological levels, and using specific antibodies, that tau LLPS leads to pathological conformations such as N-terminal exposure and oligomeric species.
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26
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Fischer I, Baas PW. Resurrecting the Mysteries of Big Tau. Trends Neurosci 2020; 43:493-504. [PMID: 32434664 DOI: 10.1016/j.tins.2020.04.007] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Revised: 03/28/2020] [Accepted: 04/20/2020] [Indexed: 12/16/2022]
Abstract
Tau, a microtubule-associated protein that modifies the dynamic properties and organization of microtubules in neurons and affects axonal transport, shows remarkable heterogeneity, with multiple isoforms (45-65 kDa) generated by alternative splicing. A high-molecular-weight (HMW) isoform (110 kDa) that contains an additional large exon termed 4a was discovered more than 25 years ago. This isoform, called Big tau, is expressed mainly in the adult peripheral nervous system (PNS), but also in adult neurons of the central nervous system (CNS) that extend processes into the periphery. Surprisingly little has been learned about Big tau since its initial characterization, leaving a significant gap in knowledge about how the dramatic switch to Big tau affects the properties of neurons in the context of development, disease, or injury. Here we review what was learned about the structure and distribution of Big tau in those earlier studies, and add contemporary insights to resurrect interest in the mysteries of Big tau and thereby set a path for future studies.
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Affiliation(s)
- Itzhak Fischer
- Drexel University College of Medicine, Department of Neurobiology and Anatomy, 2900 Queen Lane, Philadelphia, PA 19129, USA.
| | - Peter W Baas
- Drexel University College of Medicine, Department of Neurobiology and Anatomy, 2900 Queen Lane, Philadelphia, PA 19129, USA.
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Targeting Aggrephagy for the Treatment of Alzheimer's Disease. Cells 2020; 9:cells9020311. [PMID: 32012902 PMCID: PMC7072705 DOI: 10.3390/cells9020311] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2019] [Revised: 01/25/2020] [Accepted: 01/26/2020] [Indexed: 12/17/2022] Open
Abstract
Alzheimer’s disease (AD) is one of the most common neurodegenerative diseases in older individuals with specific neuropsychiatric symptoms. It is a proteinopathy, pathologically characterized by the presence of misfolded protein (Aβ and Tau) aggregates in the brain, causing progressive dementia. Increasing studies have provided evidence that the defect in protein-degrading systems, especially the autophagy-lysosome pathway (ALP), plays an important role in the pathogenesis of AD. Recent studies have demonstrated that AD-associated protein aggregates can be selectively recognized by some receptors and then be degraded by ALP, a process termed aggrephagy. In this study, we reviewed the role of aggrephagy in AD development and discussed the strategy of promoting aggrephagy using small molecules for the treatment of AD.
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Hintermayer MA, Volkening K, Moszczynski AJ, Donison N, Strong MJ. Tau protein phosphorylation at Thr 175 initiates fibril formation via accessibility of the N-terminal phosphatase-activating domain. J Neurochem 2019; 155:313-326. [PMID: 31853971 DOI: 10.1111/jnc.14942] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2019] [Revised: 12/10/2019] [Accepted: 12/13/2019] [Indexed: 01/21/2023]
Abstract
One of the neuropathological hallmarks of the tauopathies is the formation of neuronal cytoplasmic inclusions and fibrils of microtubule-associated tau protein (tau). The phosphorylation of Thr175 of tau (pThr175 tau) appears to be sufficient for fibril formation in vitro and in vivo, but the mechanism by which this initiates fibril formation is unknown. Using transient transfections of tau mutants into HEK293T cells, we determined that the phosphorylation of Thr175 leads to exposure of the tau N-terminal phosphatase-activating domain (PAD). The exposed PAD is known to interact with protein phosphatase-1 (PP1) resulting in glycogen synthase kinase 3β (GSK3β) activation. In vivo, a single traumatic controlled cortical injury in rats also resulted in the phosphorylation of Thr175 and increased exposure of tau PAD followed by pathological tau fibril formation. Taken together, these data suggest that neurotoxicity may be precipitated by phosphorylation at Thr175 and subsequent tau PAD exposure, GSK3β activation and tau fibril formation. Cover Image for this issue: doi: 10.1111/jnc.14767.
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Affiliation(s)
- Matthew A Hintermayer
- Molecular Brain Research Group, Robarts Research Institute, Schulich School of Medicine & Dentistry, Western University, London, Ontario, Canada
| | - Kathryn Volkening
- Molecular Brain Research Group, Robarts Research Institute, Schulich School of Medicine & Dentistry, Western University, London, Ontario, Canada.,Department of Clinical Neurological Sciences, Schulich School of Medicine & Dentistry, Western University, London, ON, Canada
| | - Alexander J Moszczynski
- Molecular Brain Research Group, Robarts Research Institute, Schulich School of Medicine & Dentistry, Western University, London, Ontario, Canada
| | - Neil Donison
- Molecular Brain Research Group, Robarts Research Institute, Schulich School of Medicine & Dentistry, Western University, London, Ontario, Canada
| | - Michael J Strong
- Molecular Brain Research Group, Robarts Research Institute, Schulich School of Medicine & Dentistry, Western University, London, Ontario, Canada.,Department of Clinical Neurological Sciences, Schulich School of Medicine & Dentistry, Western University, London, ON, Canada
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A MultiTEP platform-based epitope vaccine targeting the phosphatase activating domain (PAD) of tau: therapeutic efficacy in PS19 mice. Sci Rep 2019; 9:15455. [PMID: 31664089 PMCID: PMC6820729 DOI: 10.1038/s41598-019-51809-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Accepted: 10/08/2019] [Indexed: 11/30/2022] Open
Abstract
Pathological tau correlates well with cognitive impairments in Alzheimer’s disease (AD) patients and therefore represents a promising target for immunotherapy. Targeting an appropriate B cell epitope in pathological tau could in theory produce an effective reduction of pathology without disrupting the function of normal native tau. Recent data demonstrate that the N-terminal region of tau (aa 2-18), termed the “phosphatase activation domain (PAD)”, is hidden within native Tau in a ‘paperclip’-like conformation. Conversely, PAD is exposed in pathological tau and plays an essential role in the inhibition of fast axonal transport and tau polymerization. Thus, we hypothesized that anti-tau2-18 antibodies may safely and specifically reduce pathological tau and prevent further aggregation, which in turn would neutralize tau toxicity. Therefore, we evaluated the immunogenicity and therapeutic efficacy of our MultiTEP platform-based vaccine targeting tau2-18 formulated with AdvaxCpG adjuvant (AV-1980R/A) in PS19 tau transgenic mice. The AV-1980R/A induced extremely high antibody responses and the resulting sera recognized neurofibrillary tangles and plaque-associated dystrophic neurites in AD brain sections. In addition, under non-denaturing conditions AV-1980R/A sera preferentially recognized AD-associated tau. Importantly, vaccination also prevented age-related motor and cognitive deficits in PS19 mice and significantly reduced insoluble total and phosphorylated tau species. Taken together, these findings suggest that predominantly targeting misfolded tau with AV-1980R/A could represent an effective strategy for AD immunotherapy.
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30
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Shoeibi A, Olfati N, Litvan I. Frontrunner in Translation: Progressive Supranuclear Palsy. Front Neurol 2019; 10:1125. [PMID: 31695675 PMCID: PMC6817677 DOI: 10.3389/fneur.2019.01125] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Accepted: 10/08/2019] [Indexed: 12/26/2022] Open
Abstract
Progressive supranuclear palsy (PSP) is a four-repeat tau proteinopathy. Abnormal tau deposition is not unique for PSP and is the basic pathologic finding in some other neurodegenerative disorders such as Alzheimer's disease (AD), age-related tauopathy, frontotemporal degeneration, corticobasal degeneration, and chronic traumatic encephalopathy. While AD research has mostly been focused on amyloid beta pathology until recently, PSP as a prototype of a primary tauopathy with high clinical-pathologic correlation and a rapid course is a crucial candidate for tau therapeutic research. Several novel approaches to slow disease progression are being developed. It is expected that the benefits of translational research in this disease will extend beyond the PSP population. This article reviews advances in the diagnosis, epidemiology, pathology, hypothesized etiopathogenesis, and biomarkers and disease-modifying therapeutic approaches of PSP that is leading it to become a frontrunner in translation.
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Affiliation(s)
- Ali Shoeibi
- Department of Neurology, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Nahid Olfati
- Department of Neurology, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Irene Litvan
- UC San Diego Department of Neurosciences, Parkinson and Other Movement Disorder Center, La Jolla, CA, United States
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31
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Joly-Amado A, Davtyan H, Serraneau K, Jules P, Zitnyar A, Pressman E, Zagorski K, Antonyan T, Hovakimyan A, Paek HJ, Gordon MN, Cribbs DH, Petrovsky N, Agadjanyan MG, Ghochikyan A, Morgan D. Active immunization with tau epitope in a mouse model of tauopathy induced strong antibody response together with improvement in short memory and pSer396-tau pathology. Neurobiol Dis 2019; 134:104636. [PMID: 31629891 DOI: 10.1016/j.nbd.2019.104636] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Revised: 08/30/2019] [Accepted: 10/07/2019] [Indexed: 12/16/2022] Open
Abstract
Abnormal tau hyperphosphorylation and its aggregation into neurofibrillary tangles are a hallmark of tauopathies, neurodegenerative disorders that include Alzheimer's disease (AD). Active and passive Tau-immunotherapy has been proposed as a therapeutic approach to AD with mixed results. One of the limitations of active immunotherapy may be associated with the mediocre immunogenicity of vaccines that are not inducing therapeutically potent titers of antibodies. The aim of this study was to test the efficacy of an anti-tau vaccine, AV-1980R/A composed of N terminal peptide of this molecule fused with an immunogenic MultiTEP platform and formulated in a strong adjuvant, AdvaxCpG in a Tg4510 mouse model of tauopathy. Experimental mice were immunized with AV-1980R/A and a control group of mice were injected with adjuvant only. Nontransgenic and tetracycline transactivator (tTA) transgenic littermates were included as baseline controls to contrast with the tau phenotype. Active immunization with AV-1980R/A induced very strong anti-tau humoral immune responses in both nontransgenic and transgenic mice with evidence of IgG in brains of AV-1980R/A vaccinated mice. These experimental animals displayed an improvement in short-term memory during a novel object recognition test. However, impairments in other behavioral tasks were not prevented by AV-1980R/A vaccinations. At the same time, high titers of anti-tau antibodies reduced hyperphosphorylated pSer396 tau but did not lower the level of other phosphorylated tau species in the brains of AV-1980R/A vaccinated mice. These data indicate that active immunotherapy with an N-terminal Tau epitope was only partially effective in improving cognition and reducing pathology in the stringent Tg4510 mouse model of tauopathy.
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Affiliation(s)
- A Joly-Amado
- USF Health Byrd Alzheimer's Institute, Tampa, FL 33613, USA.
| | - H Davtyan
- The Institute for Molecular Medicine, Huntington Beach, CA 92647, USA; Institute for Memory Impairments and Neurological Disorders, University of California Irvine, Irvine, CA 92697, USA
| | - K Serraneau
- USF Health Byrd Alzheimer's Institute, Tampa, FL 33613, USA
| | - P Jules
- USF Health Byrd Alzheimer's Institute, Tampa, FL 33613, USA
| | - A Zitnyar
- USF Health Byrd Alzheimer's Institute, Tampa, FL 33613, USA
| | - E Pressman
- USF Health Byrd Alzheimer's Institute, Tampa, FL 33613, USA
| | - K Zagorski
- The Institute for Molecular Medicine, Huntington Beach, CA 92647, USA
| | - T Antonyan
- The Institute for Molecular Medicine, Huntington Beach, CA 92647, USA
| | - A Hovakimyan
- The Institute for Molecular Medicine, Huntington Beach, CA 92647, USA
| | - H J Paek
- Molecular Pharmacology and Physiology, College of Medicine, University of South Florida, Tampa, FL, USA
| | - M N Gordon
- USF Health Byrd Alzheimer's Institute, Tampa, FL 33613, USA
| | - D H Cribbs
- Institute for Memory Impairments and Neurological Disorders, University of California Irvine, Irvine, CA 92697, USA
| | - N Petrovsky
- Flinders Med. Ctr., Bedford Park, Adelaide 5042, Australia
| | - M G Agadjanyan
- The Institute for Molecular Medicine, Huntington Beach, CA 92647, USA
| | - A Ghochikyan
- The Institute for Molecular Medicine, Huntington Beach, CA 92647, USA
| | - D Morgan
- USF Health Byrd Alzheimer's Institute, Tampa, FL 33613, USA
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32
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Ivashko-Pachima Y, Gozes I. A Novel Microtubule-Tau Association Enhancer and Neuroprotective Drug Candidate: Ac-SKIP. Front Cell Neurosci 2019; 13:435. [PMID: 31632241 PMCID: PMC6779860 DOI: 10.3389/fncel.2019.00435] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Accepted: 09/12/2019] [Indexed: 11/13/2022] Open
Abstract
Activity-dependent neuroprotective protein (ADNP) has been initially discovered through its eight amino acid sequence NAPVSIPQ, which shares SIP motif with SALLRSIPA - a peptide derived from activity-dependent neurotrophic factor (ADNF). Mechanistically, both NAPVSIPQ and SALLRSIPA contain a SIP motif that is identified as a variation of SxIP domain, providing direct interaction with microtubule end-binding proteins (EBs). The peptide SKIP was shown before to provide neuroprotection in vitro and protect against Adnp-related axonal transport deficits in vivo. Here we show, for the first time that SKIP enhanced microtubule dynamics, and prevented Tau-microtubule dissociation and microtubule disassembly induced by the Alzheimer's related zinc intoxication. Furthermore, we introduced, CH3CO-SKIP-NH2 (Ac-SKIP), providing efficacious neuroprotection. Since microtubule - Tau organization and dynamics is central in axonal microtubule cytoskeleton and transport, tightly related to aging processes and Alzheimer's disease, our current study provides a compelling molecular explanation to the in vivo activity of SKIP, placing SKIP motif as a central focus for MT-based neuroprotection in tauopathies with axonal transport implications.
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Affiliation(s)
- Yanina Ivashko-Pachima
- Dr. Diana and Zelman Elton (Elbaum) Laboratory for Molecular Neuroendocrinology, Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Sagol School of Neuroscience, Adams Super Center for Brain Studies, Tel Aviv University, Tel Aviv, Israel
| | - Illana Gozes
- Dr. Diana and Zelman Elton (Elbaum) Laboratory for Molecular Neuroendocrinology, Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Sagol School of Neuroscience, Adams Super Center for Brain Studies, Tel Aviv University, Tel Aviv, Israel
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33
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Multi-site dynamic recording for Aβ oligomers-induced Alzheimer's disease in vitro based on neuronal network chip. Biosens Bioelectron 2019; 133:183-191. [PMID: 30928737 DOI: 10.1016/j.bios.2019.03.025] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Revised: 03/11/2019] [Accepted: 03/13/2019] [Indexed: 01/31/2023]
Abstract
Alzheimer's disease (AD) is a chronic central neurodegenerative disease. The pathological features of AD are the extracellular deposition of senile plaques formed by amyloid-β oligomers (AβOs) and the intracellular accumulation of neurofibrillary tangles. However, due to the lack of effective method and experimental models to study the cognitive decline, communication at cell resolution and the implementation of interventions, the diagnosis and treatment on AD still progress slowly. In this paper, we established a pathological model of AD in vitro based on AβOs-induced hippocampal neuronal network chip for multi-site dynamic analysis of the neuronal electrical activity and network connection. The multiple characteristic parameters, including positive and negative spike intervals, firing rate and peak-to-peak values, were extracted through the analysis of spike signals, and two firing patterns from the interneurons and pyramidal neurons were recorded. The spatial firing patterns mapping and cross-correlation between channels were performed to validate the degeneration of neuronal network connectivity. Moreover, an electrical stimulation with frequency at 40 Hz was exerted to preliminarily explore the therapeutic effect on the pathological model of AD. This neuronal network chip enables the implementation of AD models in vitro for studying basic mechanisms of neurodegeneration within networks and for the parallel testing of various potential therapies. It can be a novel technique in the research of AD pathological model in vitro.
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34
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Christensen KR, Beach TG, Serrano GE, Kanaan NM. Pathogenic tau modifications occur in axons before the somatodendritic compartment in mossy fiber and Schaffer collateral pathways. Acta Neuropathol Commun 2019; 7:29. [PMID: 30819250 PMCID: PMC6394076 DOI: 10.1186/s40478-019-0675-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Accepted: 02/07/2019] [Indexed: 12/19/2022] Open
Abstract
The deposition of tau pathology in Alzheimer's disease (AD) may occur first in axons of neurons and then progress back into the cell bodies to form neurofibrillary tangles, however, studies have not directly analyzed this relationship in relatively discrete circuits within the human hippocampus. In the early phases of tau deposition, both AT8 phosphorylation and exposure of the amino terminus of tau occurs in tauopathies, and these modifications are linked to mechanisms of synaptic and axonal dysfunction. Here, we examined the localization of these tau pathologies in well-characterized post-mortem human tissue samples from the hippocampus of 44 cases ranging between non-demented and mild cognitively impaired to capture a time at which intrahippocampal pathways show a range in the extent of tau deposition. The tissue sections were analyzed for AT8 (AT8 antibody), amino terminus exposure (TNT2 antibody), and amyloid-β (MOAB2 antibody) pathology in hippocampal strata containing the axons and neuronal cell bodies of the CA3-Schaffer collateral and dentate granule-mossy fiber pathways. We show that tau pathology first appears in the axonal compartment of affected neurons in the absence of observable tau pathology in the corresponding cell bodies in several cases. Additionally, deposition of tau in these intrahippocampal pathways was independent of the presence of Aβ plaques. We confirmed that the majority of tau pathology positive neuropil threads were axonal in origin and not dendritic using an axonal marker (i.e. SMI312 antibody) and somatodendritic marker (i.e. MAP2 antibody). Taken together, these results support the hypothesis that AT8 phosphorylation and amino terminus exposure are early pathological events and that the deposition of tau pathology, at least in the studied pathways, occurs first in the axonal compartment prior to observable pathology in the somata. These findings highlight the importance on targeting tau deposition, ideally in the initial phases of its deposition in axons.
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Affiliation(s)
- Kyle R Christensen
- Department of Translational Science and Molecular Medicine, Michigan State University, College of Human Medicine, 400 Monroe Ave NW, Grand Rapids, MI, 49053, USA
- Neuroscience Program, Michigan State University, East Lansing, MI, USA
| | | | | | - Nicholas M Kanaan
- Department of Translational Science and Molecular Medicine, Michigan State University, College of Human Medicine, 400 Monroe Ave NW, Grand Rapids, MI, 49053, USA.
- Neuroscience Program, Michigan State University, East Lansing, MI, USA.
- Hauenstein Neuroscience Center, Mercy Health Saint Mary's, Grand Rapids, MI, USA.
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35
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Combs B, Mueller RL, Morfini G, Brady ST, Kanaan NM. Tau and Axonal Transport Misregulation in Tauopathies. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1184:81-95. [PMID: 32096030 DOI: 10.1007/978-981-32-9358-8_7] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Tau is a microtubule-associated protein that is involved in both normal and pathological processes in neurons. Since the discovery and characterization of tau over 40 years ago, our understanding of tau's normal functions and toxic roles in neurodegenerative tauopathies has continued to expand. Fast axonal transport is a critical process for maintaining axons and functioning synapses, critical subcellular compartments underlying neuronal connectivity. Signs of fast axonal transport disruption are pervasive in Alzheimer's disease and other tauopathies and various mechanisms have been proposed for regulation of fast axonal transport by tau. Post-translational modifications of tau including phosphorylation at specific sites, FTDP-17 point mutations, and oligomerization, confer upon tau a toxic effect on fast axonal transport. Consistent with the well-established dependence of axons on fast axonal transport, these disease-related modifications are closely associated temporally and spatially with axonal degeneration in the early disease stages. These factors position tau as a potentially critical factor mediating the disruption of fast axonal transport that precedes synaptic dysfunction and axonal degeneration at later disease stages. In this chapter, we review the evidence that tau affects fast axonal transport and examine several potential mechanisms proposed to underlie this toxicity.
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Affiliation(s)
- Benjamin Combs
- Department of Translational Neuroscience, College of Human Medicine, Michigan State University, Grand Rapids, MI, USA
| | - Rebecca L Mueller
- Department of Translational Neuroscience, College of Human Medicine, Michigan State University, Grand Rapids, MI, USA.,Neuroscience Program, Michigan State University, East Lansing, MI, USA
| | - Gerardo Morfini
- Department of Anatomy and Cell Biology, University of Illinois at Chicago, Chicago, IL, USA.,Marine Biological Laboratory, Woods Hole, MA, USA
| | - Scott T Brady
- Department of Anatomy and Cell Biology, University of Illinois at Chicago, Chicago, IL, USA.,Marine Biological Laboratory, Woods Hole, MA, USA
| | - Nicholas M Kanaan
- Department of Translational Neuroscience, College of Human Medicine, Michigan State University, Grand Rapids, MI, USA. .,Neuroscience Program, Michigan State University, East Lansing, MI, USA. .,Hauenstein Neuroscience Center, Mercy Health Saint Mary's, Grand Rapids, MI, USA.
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36
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Gallardo G, Holtzman DM. Amyloid-β and Tau at the Crossroads of Alzheimer's Disease. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1184:187-203. [PMID: 32096039 DOI: 10.1007/978-981-32-9358-8_16] [Citation(s) in RCA: 89] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Alzheimer's disease (AD) is the most common form of dementia characterized neuropathologically by senile plaques and neurofibrillary tangles (NFTs). Early breakthroughs in AD research led to the discovery of amyloid-β as the major component of senile plaques and tau protein as the major component of NFTs. Shortly following the identification of the amyloid-β (Aβ) peptide was the discovery that a genetic mutation in the amyloid precursor protein (APP), a type1 transmembrane protein, can be a cause of autosomal dominant familial AD (fAD). These discoveries, coupled with other breakthroughs in cell biology and human genetics, have led to a theory known as the "amyloid hypothesis", which postulates that amyloid-β is the predominant driving factor in AD development. Nonetheless, more recent advances in imaging analysis, biomarkers and mouse models are now redefining this original hypothesis, as it is likely amyloid-β, tau and other pathophysiological mechanism such as inflammation, come together at a crossroads that ultimately leads to the development of AD.
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Affiliation(s)
- Gilbert Gallardo
- Department of Neurology, Washington University School of Medicine, St. Louis, MO, USA.,Hope Center for Neurological Disorders, Washington University, St. Louis, MO, USA
| | - David M Holtzman
- Department of Neurology, Washington University School of Medicine, St. Louis, MO, USA. .,Hope Center for Neurological Disorders, Washington University, St. Louis, MO, USA. .,Charles F. and Joanne Knight Alzheimer's Disease Research Center, Washington University, St. Louis, MO, USA.
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37
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Tapia-Rojas C, Cabezas-Opazo F, Deaton CA, Vergara EH, Johnson GVW, Quintanilla RA. It's all about tau. Prog Neurobiol 2018; 175:54-76. [PMID: 30605723 DOI: 10.1016/j.pneurobio.2018.12.005] [Citation(s) in RCA: 108] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2017] [Revised: 12/07/2018] [Accepted: 12/28/2018] [Indexed: 12/21/2022]
Abstract
Tau is a protein that is highly enriched in neurons and was originally defined by its ability to bind and stabilize microtubules. However, it is now becoming evident that the functions of tau extend beyond its ability to modulate microtubule dynamics. Tau plays a role in mediating axonal transport, synaptic structure and function, and neuronal signaling pathways. Although tau plays important physiological roles in neurons, its involvement in neurodegenerative diseases, and most prominently in the pathogenesis of Alzheimer disease (AD), has directed the majority of tau studies. However, a thorough knowledge of the physiological functions of tau and its post-translational modifications under normal conditions are necessary to provide the foundation for understanding its role in pathological settings. In this review, we will focus on human tau, summarizing tau structure and organization, as well as its posttranslational modifications associated with physiological processes. We will highlight possible mechanisms involved in mediating the turnover of tau and finally discuss newly elucidated tau functions in a physiological context.
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Affiliation(s)
- Cheril Tapia-Rojas
- Laboratory of Neurobiology of Aging, Centro de Biología Celular y Biomedicina (CEBICEM), Universidad San Sebastián, Santiago, Chile
| | - Fabian Cabezas-Opazo
- Laboratory of Neurodegenerative Diseases, Centro de Investigación Biomédica, Universidad Autónoma de Chile, Santiago, Chile
| | - Carol A Deaton
- Department of Anesthesiology and Perioperative Medicine, University of Rochester Medical Center, NY, USA
| | - Erick H Vergara
- Laboratory of Neurodegenerative Diseases, Centro de Investigación Biomédica, Universidad Autónoma de Chile, Santiago, Chile
| | - Gail V W Johnson
- Department of Anesthesiology and Perioperative Medicine, University of Rochester Medical Center, NY, USA
| | - Rodrigo A Quintanilla
- Laboratory of Neurodegenerative Diseases, Centro de Investigación Biomédica, Universidad Autónoma de Chile, Santiago, Chile; Centro de Investigación y Estudio del Consumo de Alcohol en Adolescentes (CIIA), Santiago, Chile.
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38
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Rad SK, Arya A, Karimian H, Madhavan P, Rizwan F, Koshy S, Prabhu G. Mechanism involved in insulin resistance via accumulation of β-amyloid and neurofibrillary tangles: link between type 2 diabetes and Alzheimer's disease. Drug Des Devel Ther 2018; 12:3999-4021. [PMID: 30538427 PMCID: PMC6255119 DOI: 10.2147/dddt.s173970] [Citation(s) in RCA: 85] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The pathophysiological link between type 2 diabetes mellitus (T2DM) and Alzheimer's disease (AD) has been suggested in several reports. Few findings suggest that T2DM has strong link in the development process of AD, and the complete mechanism is yet to be revealed. Formation of amyloid plaques (APs) and neurofibrillary tangles (NFTs) are two central hallmarks in the AD. APs are the dense composites of β-amyloid protein (Aβ) which accumulates around the nerve cells. Moreover, NFTs are the twisted fibers containing hyperphosphorylated tau proteins present in certain residues of Aβ that build up inside the brain cells. Certain factors contribute to the aetiogenesis of AD by regulating insulin signaling pathway in the brain and accelerating the formation of neurotoxic Aβ and NFTs via various mechanisms, including GSK3β, JNK, CamKII, CDK5, CK1, MARK4, PLK2, Syk, DYRK1A, PPP, and P70S6K. Progression to AD could be influenced by insulin signaling pathway that is affected due to T2DM. Interestingly, NFTs and APs lead to the impairment of several crucial cascades, such as synaptogenesis, neurotrophy, and apoptosis, which are regulated by insulin, cholesterol, and glucose metabolism. The investigation of the molecular cascades through insulin functions in brain contributes to probe and perceive progressions of diabetes to AD. This review elaborates the molecular insights that would help to further understand the potential mechanisms linking T2DM and AD.
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Affiliation(s)
- Sima Kianpour Rad
- Department of Molecular Medicine, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Aditya Arya
- Department of Pharmacology and Therapeutics, School of Medicine, Faculty of Health and Medical Sciences, Taylor's University, Subang Jaya, Malaysia,
- Department of Pharmacology and Therapeutics, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Parkville, VIC, Australia,
- Malaysian Institute of Pharmaceuticals and Nutraceuticals (IPharm), Bukit Gambir, Gelugor, Pulau Pinang, Malaysia,
| | - Hamed Karimian
- Department of Pharmacology and Therapeutics, School of Medicine, Faculty of Health and Medical Sciences, Taylor's University, Subang Jaya, Malaysia,
| | - Priya Madhavan
- School of Medicine, Faculty of Health and Medical Sciences, Taylor's University, Subang Jaya, Malaysia
| | - Farzana Rizwan
- School of Medicine, Faculty of Health and Medical Sciences, Taylor's University, Subang Jaya, Malaysia
| | - Shajan Koshy
- School of Medicine, Faculty of Health and Medical Sciences, Taylor's University, Subang Jaya, Malaysia
| | - Girish Prabhu
- School of Medicine, Faculty of Health and Medical Sciences, Taylor's University, Subang Jaya, Malaysia
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39
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Chen Y, Fu AKY, Ip NY. Synaptic dysfunction in Alzheimer's disease: Mechanisms and therapeutic strategies. Pharmacol Ther 2018; 195:186-198. [PMID: 30439458 DOI: 10.1016/j.pharmthera.2018.11.006] [Citation(s) in RCA: 108] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Alzheimer's disease (AD), the most prevalent neurodegenerative disease in the elderly population, is characterized by progressive cognitive decline and pathological hallmarks of amyloid plaques and neurofibrillary tangles. However, its pathophysiological mechanisms are poorly understood, and diagnostic tools and interventions are limited. Here, we review recent research on the amyloid hypothesis and beta-amyloid-induced dysfunction of neuronal synapses through distinct cell surface receptors. We also review how tau protein leads to synaptotoxicity through pathological modification, localization, and propagation. Finally, we discuss experimental therapeutics for AD and propose potential applications of disease-modifying strategies targeting synaptic failure for improved treatment of AD.
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Affiliation(s)
- Yu Chen
- Division of Life Science, State Key Laboratory of Molecular Neuroscience and Molecular Neuroscience Center, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China; The Brain Cognition and Brain Disease Institute, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, Guangdong, China; Guangdong Provincial Key Laboratory of Brain Science, Disease and Drug Development, HKUST Shenzhen Research Institute, Shenzhen, Guangdong, China.
| | - Amy K Y Fu
- Division of Life Science, State Key Laboratory of Molecular Neuroscience and Molecular Neuroscience Center, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China; Guangdong Provincial Key Laboratory of Brain Science, Disease and Drug Development, HKUST Shenzhen Research Institute, Shenzhen, Guangdong, China
| | - Nancy Y Ip
- Division of Life Science, State Key Laboratory of Molecular Neuroscience and Molecular Neuroscience Center, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China; Guangdong Provincial Key Laboratory of Brain Science, Disease and Drug Development, HKUST Shenzhen Research Institute, Shenzhen, Guangdong, China.
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Tiernan CT, Ginsberg SD, He B, Ward SM, Guillozet-Bongaarts AL, Kanaan NM, Mufson EJ, Counts SE. Pretangle pathology within cholinergic nucleus basalis neurons coincides with neurotrophic and neurotransmitter receptor gene dysregulation during the progression of Alzheimer's disease. Neurobiol Dis 2018; 117:125-136. [PMID: 29859871 PMCID: PMC6278831 DOI: 10.1016/j.nbd.2018.05.021] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2018] [Accepted: 05/30/2018] [Indexed: 01/22/2023] Open
Abstract
Cholinergic basal forebrain neurons of the nucleus basalis of Meynert (nbM) regulate attentional and memory function and are exquisitely prone to tau pathology and neurofibrillary tangle (NFT) formation during the progression of Alzheimer's disease (AD). nbM neurons require the neurotrophin nerve growth factor (NGF), its cognate receptor TrkA, and the pan-neurotrophin receptor p75NTR for their maintenance and survival. Additionally, nbM neuronal activity and cholinergic tone are regulated by the expression of nicotinic (nAChR) and muscarinic (mAChR) acetylcholine receptors as well as receptors modulating glutamatergic and catecholaminergic afferent signaling. To date, the molecular and cellular relationships between the evolution of tau pathology and nbM neuronal survival remain unknown. To address this knowledge gap, we profiled cholinotrophic pathway genes within nbM neurons immunostained for pS422, a pretangle phosphorylation event preceding tau C-terminal truncation at D421, or dual-labeled for pS422 and TauC3, a later stage tau neo-epitope revealed by this same C-terminal truncation event, via single-population custom microarray analysis. nbM neurons were obtained from postmortem tissues from subjects who died with an antemortem clinical diagnosis of no cognitive impairment (NCI), mild cognitive impairment (MCI), or mild/moderate AD. Quantitative analysis revealed significant downregulation of mRNAs encoding TrkA as well as TrkB, TrkC, and the Trk-mediated downstream pro-survival kinase Akt in pS422+ compared to unlabeled, pS422-negative nbM neurons. In addition, pS422+ neurons displayed a downregulation of transcripts encoding NMDA receptor subunit 2B, metabotropic glutamate receptor 2, D2 dopamine receptor, and β1 adrenoceptor. By contrast, transcripts encoding p75NTR were downregulated in dual-labeled pS422+/TauC3+ neurons. Appearance of the TauC3 epitope was also associated with an upregulation of the α7 nAChR subunit and differential downregulation of the β2 nAChR subunit. Notably, we found that gene expression patterns for each cell phenotype did not differ with clinical diagnosis. However, linear regression revealed that global cognition and Braak stage were predictors of select transcript changes within both unlabeled and pS422+/TauC3- neurons. Taken together, these cell phenotype-specific gene expression profiling data suggest that dysregulation of neurotrophic and neurotransmitter signaling is an early pathogenic mechanism associated with NFT formation in vulnerable nbM neurons and cognitive decline in AD, which may be amenable to therapeutic intervention early in the disease process.
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Affiliation(s)
- Chelsea T Tiernan
- Department of Translational Science and Molecular Medicine, Michigan State University, Grand Rapids, MI, USA
| | - Stephen D Ginsberg
- Center for Dementia Research, Nathan Kline Institute, Orangeburg, NY, USA; Department of Psychiatry, NYU Langone School of Medicine, New York, NY, USA; Department of Physiology & Neuroscience, NYU Langone School of Medicine, New York, NY, USA; NYU Neuroscience Institute, NYU Langone School of Medicine, New York, NY, USA
| | - Bin He
- Department of Neurobiology, Barrow Neurological Institute, Phoenix, AZ, USA
| | - Sarah M Ward
- Department of Translational Science and Molecular Medicine, Michigan State University, Grand Rapids, MI, USA
| | | | - Nicholas M Kanaan
- Department of Translational Science and Molecular Medicine, Michigan State University, Grand Rapids, MI, USA; Hauenstein Neurosciences Center, Mercy Health Saint Mary's Hospital, Grand Rapids, MI, USA
| | - Elliott J Mufson
- Department of Neurobiology, Barrow Neurological Institute, Phoenix, AZ, USA
| | - Scott E Counts
- Department of Translational Science and Molecular Medicine, Michigan State University, Grand Rapids, MI, USA; Hauenstein Neurosciences Center, Mercy Health Saint Mary's Hospital, Grand Rapids, MI, USA; Department of Family Medicine, Michigan State University, Grand Rapids, MI, USA; Michigan Alzheimer's Disease Core Center, Ann Arbor, MI, USA.
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41
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Selective targeting of 3 repeat Tau with brain penetrating single chain antibodies for the treatment of neurodegenerative disorders. Acta Neuropathol 2018; 136:69-87. [PMID: 29934874 DOI: 10.1007/s00401-018-1869-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Revised: 05/22/2018] [Accepted: 05/22/2018] [Indexed: 01/20/2023]
Abstract
Alzheimer's disease (AD) is the most common form of dementia in the elderly affecting more than 5 million people in the U.S. AD is characterized by the accumulation of β-amyloid (Aβ) and Tau in the brain, and is manifested by severe impairments in memory and cognition. Therefore, removing tau pathology has become one of the main therapeutic goals for the treatment of AD. Tau (tubulin-associated unit) is a major neuronal cytoskeletal protein found in the CNS encoded by the gene MAPT. Alternative splicing generates two major isoforms of tau containing either 3 or 4 repeat (R) segments. These 3R or 4RTau species are differentially expressed in neurodegenerative diseases. Previous studies have been focused on reducing Tau accumulation with antibodies against total Tau, 4RTau or phosphorylated isoforms. Here, we developed a brain penetrating, single chain antibody that specifically recognizes a pathogenic 3RTau. This single chain antibody was modified by the addition of a fragment of the apoB protein to facilitate trafficking into the brain, once in the CNS these antibody fragments reduced the accumulation of 3RTau and related deficits in a transgenic mouse model of tauopathy. NMR studies showed that the single chain antibody recognized an epitope at aa 40-62 of 3RTau. This single chain antibody reduced 3RTau transmission and facilitated the clearance of Tau via the endosomal-lysosomal pathway. Together, these results suggest that targeting 3RTau with highly specific, brain penetrating, single chain antibodies might be of potential value for the treatment of tauopathies such as Pick's Disease.
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Bencze J, Mórotz GM, Seo W, Bencs V, Kálmán J, Miller CCJ, Hortobágyi T. Biological function of Lemur tyrosine kinase 2 (LMTK2): implications in neurodegeneration. Mol Brain 2018; 11:20. [PMID: 29631601 PMCID: PMC5891947 DOI: 10.1186/s13041-018-0363-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Accepted: 03/26/2018] [Indexed: 12/14/2022] Open
Abstract
Neurodegenerative disorders are frequent, incurable diseases characterised by abnormal protein accumulation and progressive neuronal loss. Despite their growing prevalence, the underlying pathomechanism remains unclear. Lemur tyrosine kinase 2 (LMTK2) is a member of a transmembrane serine/threonine-protein kinase family. Although it was described more than a decade ago, our knowledge on LMTK2’s biological functions is still insufficient. Recent evidence has suggested that LMTK2 is implicated in neurodegeneration. After reviewing the literature, we identified three LMTK2-mediated mechanisms which may contribute to neurodegenerative processes: disrupted axonal transport, tau hyperphosphorylation and enhanced apoptosis. Moreover, LMTK2 gene expression is decreased in an Alzheimer’s disease mouse model. According to these features, LMTK2 might be a promising therapeutic target in near future. However, further investigations are required to clarify the exact biological functions of this unique protein.
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Affiliation(s)
- János Bencze
- Division of Neuropathology, Institute of Pathology, Faculty of Medicine, University of Debrecen, Nagyerdei krt. 98., Debrecen, H-4032, Hungary
| | - Gábor Miklós Mórotz
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry Psychology and Neuroscience, King's College London, London, UK
| | - Woosung Seo
- Division of Neuropathology, Institute of Pathology, Faculty of Medicine, University of Debrecen, Nagyerdei krt. 98., Debrecen, H-4032, Hungary
| | - Viktor Bencs
- Division of Neuropathology, Institute of Pathology, Faculty of Medicine, University of Debrecen, Nagyerdei krt. 98., Debrecen, H-4032, Hungary
| | - János Kálmán
- Department of Psychiatry, Faculty of Medicine, University of Szeged, Szeged, Hungary
| | - Christopher Charles John Miller
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry Psychology and Neuroscience, King's College London, London, UK
| | - Tibor Hortobágyi
- Division of Neuropathology, Institute of Pathology, Faculty of Medicine, University of Debrecen, Nagyerdei krt. 98., Debrecen, H-4032, Hungary. .,MTA-DE Cerebrovascular and Neurodegenerative Research Group, Debrecen, Hungary. .,Department of Pathology, Faculty of Medicine, University of Szeged, Szeged, Hungary. .,Department of Old Age Psychiatry, Institute of Psychiatry Psychology and Neuroscience, King's College London, London, UK.
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43
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Tiernan CT, Mufson EJ, Kanaan NM, Counts SE. Tau Oligomer Pathology in Nucleus Basalis Neurons During the Progression of Alzheimer Disease. J Neuropathol Exp Neurol 2018; 77:246-259. [PMID: 29378005 PMCID: PMC6251641 DOI: 10.1093/jnen/nlx120] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Although tau is the primary constituent of neurofibrillary tangles (NFTs), evidence suggests that its toxic moiety is oligomeric in Alzheimer disease (AD). In this regard, tau oligomers correlate more strongly with neuronal loss than NFTs and exhibit neurotoxicity in preclinical AD models. Here, we investigated the spatiotemporal progression of oligomeric tau accumulation within the highly vulnerable cholinergic neurons of the nucleus basalis of Meynert (nbM) in AD. Tissue from subjects who died with a clinical diagnosis of no cognitive impairment, mild cognitive impairment, or AD was immunostained with the tau oligomeric complex 1 (TOC1) antibody, a marker of tau oligomers, and p75NTR, a cholinergic cell marker. Stereological estimates revealed a significant increase in the number of TOC1 nbM immunopositive (+) neurons with a concomitant decrease in p75NTR+ nbM neurons during the transition from mild cognitive impairment to AD. Immunofluorescence identified TOC1+ neurons that colocalized with the pretangle tau marker phospho-Ser422, which persisted into late stage NFTs immunoreactive for MN423. Analysis of the nbM subfields revealed a topographical caudal to rostral gradient of TOC1+ neurons during disease progression. Taken together, these data suggest that toxic tau oligomers accumulate caudorostrally in selectively vulnerable nbM neurons during the onset of AD.
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Affiliation(s)
| | - Elliott J Mufson
- Department of Neurobiology, Barrow Neurological Institute, Phoenix, Arizona
| | - Nicholas M Kanaan
- Department of Translational Science and Molecular Medicine
- Mercy Health Saint Mary’s Hospital, Hauenstein Neurosciences Center, Grand Rapids
| | - Scott E Counts
- Department of Translational Science and Molecular Medicine
- Department of Family Medicine, Michigan State University, Grand Rapids, Michigan
- Mercy Health Saint Mary’s Hospital, Hauenstein Neurosciences Center, Grand Rapids
- Michigan Alzheimer’s Disease Core Center, Ann Arbor, Michigan
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44
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Chaudhary AR, Berger F, Berger CL, Hendricks AG. Tau directs intracellular trafficking by regulating the forces exerted by kinesin and dynein teams. Traffic 2017; 19:111-121. [PMID: 29077261 DOI: 10.1111/tra.12537] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Revised: 10/19/2017] [Accepted: 10/19/2017] [Indexed: 12/13/2022]
Abstract
Organelles, proteins, and mRNA are transported bidirectionally along microtubules by plus-end directed kinesin and minus-end directed dynein motors. Microtubules are decorated by microtubule-associated proteins (MAPs) that organize the cytoskeleton, regulate microtubule dynamics and modulate the interaction between motor proteins and microtubules to direct intracellular transport. Tau is a neuronal MAP that stabilizes axonal microtubules and crosslinks them into bundles. Dysregulation of tau leads to a range of neurodegenerative diseases known as tauopathies including Alzheimer's disease (AD). Tau reduces the processivity of kinesin and dynein by acting as an obstacle on the microtubule. Single-molecule assays indicate that kinesin-1 is more strongly inhibited than kinesin-2 or dynein, suggesting tau might act to spatially modulate the activity of specific motors. To investigate the role of tau in regulating bidirectional transport, we isolated phagosomes driven by kinesin-1, kinesin-2, and dynein and reconstituted their motility along microtubules. We find that tau biases bidirectional motility towards the microtubule minus-end in a dose-dependent manner. Optical trapping measurements show that tau increases the magnitude and frequency of forces exerted by dynein through inhibiting opposing kinesin motors. Mathematical modeling indicates that tau controls the directional bias of intracellular cargoes through differentially tuning the processivity of kinesin-1, kinesin-2, and dynein. Taken together, these results demonstrate that tau modulates motility in a motor-specific manner to direct intracellular transport, and suggests that dysregulation of tau might contribute to neurodegeneration by disrupting the balance of plus- and minus-end directed transport.
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Affiliation(s)
| | - Florian Berger
- Laboratory of Sensory Neuroscience, The Rockefeller University, New York, New York
| | - Christopher L Berger
- Department of Molecular Physiology and Biophysics, University of Vermont, Burlington, Vermont
| | - Adam G Hendricks
- Department of Bioengineering, McGill University, Montréal, Quebec, Canada
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45
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Köhler C, Fuhr V, Dinekov M. Distribution of spleen tyrosine kinase and tau phosphorylated at tyrosine 18 in a mouse model of tauopathy and in the human hippocampus. Brain Res 2017; 1677:1-13. [DOI: 10.1016/j.brainres.2017.08.029] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Revised: 08/11/2017] [Accepted: 08/25/2017] [Indexed: 12/01/2022]
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46
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Kneynsberg A, Combs B, Christensen K, Morfini G, Kanaan NM. Axonal Degeneration in Tauopathies: Disease Relevance and Underlying Mechanisms. Front Neurosci 2017; 11:572. [PMID: 29089864 PMCID: PMC5651019 DOI: 10.3389/fnins.2017.00572] [Citation(s) in RCA: 70] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Accepted: 09/29/2017] [Indexed: 12/14/2022] Open
Abstract
Tauopathies are a diverse group of diseases featuring progressive dying-back neurodegeneration of specific neuronal populations in association with accumulation of abnormal forms of the microtubule-associated protein tau. It is well-established that the clinical symptoms characteristic of tauopathies correlate with deficits in synaptic function and neuritic connectivity early in the course of disease, but mechanisms underlying these critical pathogenic events are not fully understood. Biochemical in vitro evidence fueled the widespread notion that microtubule stabilization represents tau's primary biological role and that the marked atrophy of neurites observed in tauopathies results from loss of microtubule stability. However, this notion contrasts with the mild phenotype associated with tau deletion. Instead, an analysis of cellular hallmarks common to different tauopathies, including aberrant patterns of protein phosphorylation and early degeneration of axons, suggests that alterations in kinase-based signaling pathways and deficits in axonal transport (AT) associated with such alterations contribute to the loss of neuronal connectivity triggered by pathogenic forms of tau. Here, we review a body of literature providing evidence that axonal pathology represents an early and common pathogenic event among human tauopathies. Observations of axonal degeneration in animal models of specific tauopathies are discussed and similarities to human disease highlighted. Finally, we discuss potential mechanistic pathways other than microtubule destabilization by which disease-related forms of tau may promote axonopathy.
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Affiliation(s)
- Andrew Kneynsberg
- Neuroscience Program, Michigan State University, East Lansing, MI, United States.,Department of Translational Science and Molecular Medicine, College of Human Medicine, Michigan State University, Grand Rapids, MI, United States
| | - Benjamin Combs
- Department of Translational Science and Molecular Medicine, College of Human Medicine, Michigan State University, Grand Rapids, MI, United States
| | - Kyle Christensen
- Neuroscience Program, Michigan State University, East Lansing, MI, United States.,Department of Translational Science and Molecular Medicine, College of Human Medicine, Michigan State University, Grand Rapids, MI, United States
| | - Gerardo Morfini
- Department of Anatomy and Cell Biology, University of Illinois at Chicago, Chicago, IL, United States
| | - Nicholas M Kanaan
- Neuroscience Program, Michigan State University, East Lansing, MI, United States.,Department of Translational Science and Molecular Medicine, College of Human Medicine, Michigan State University, Grand Rapids, MI, United States.,Hauenstein Neuroscience Center, Mercy Health Saint Mary's, Grand Rapids, MI, United States
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47
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Tau Isoforms Imbalance Impairs the Axonal Transport of the Amyloid Precursor Protein in Human Neurons. J Neurosci 2017; 37:58-69. [PMID: 28053030 DOI: 10.1523/jneurosci.2305-16.2016] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Revised: 09/21/2016] [Accepted: 11/04/2016] [Indexed: 01/11/2023] Open
Abstract
Tau, as a microtubule (MT)-associated protein, participates in key neuronal functions such as the regulation of MT dynamics, axonal transport, and neurite outgrowth. Alternative splicing of exon 10 in the tau primary transcript gives rise to protein isoforms with three (3R) or four (4R) MT binding repeats. Although tau isoforms are balanced in the normal adult human brain, imbalances in 3R:4R ratio have been tightly associated with the pathogenesis of several neurodegenerative disorders, yet the underlying molecular mechanisms remain elusive. Several studies exploiting tau overexpression and/or mutations suggested that perturbations in tau metabolism impair axonal transport. Nevertheless, no physiological model has yet demonstrated the consequences of altering the endogenous relative content of tau isoforms over axonal transport regulation. Here, we addressed this issue using a trans-splicing strategy that allows modulating tau exon 10 inclusion/exclusion in differentiated human-derived neurons. Upon changes in 3R:4R tau relative content, neurons showed no morphological changes, but live imaging studies revealed that the dynamics of the amyloid precursor protein (APP) were significantly impaired. Single trajectory analyses of the moving vesicles showed that predominance of 3R tau favored the anterograde movement of APP vesicles, increasing anterograde run lengths and reducing retrograde runs and segmental velocities. Conversely, the imbalance toward the 4R isoform promoted a retrograde bias by a significant reduction of anterograde velocities. These findings suggest that changes in 3R:4R tau ratio has an impact on the regulation of axonal transport and specifically in APP dynamics, which might link tau isoform imbalances with APP abnormal metabolism in neurodegenerative processes. SIGNIFICANCE STATEMENT The tau protein has a relevant role in the transport of cargos throughout neurons. Dysfunction in tau metabolism underlies several neurological disorders leading to dementia. In the adult human brain, two tau isoforms are found in equal amounts, whereas changes in such equilibrium have been associated with neurodegenerative diseases. We investigated the role of tau in human neurons in culture and found that perturbations in the endogenous balance of tau isoforms were sufficient to impair the transport of the Alzheimer's disease-related amyloid precursor protein (APP), although neuronal morphology was normal. Our results provide evidence of a direct relationship between tau isoform imbalance and defects in axonal transport, which induce an abnormal APP metabolism with important implications in neurodegeneration.
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48
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Milenkovic I, Jarc J, Dassler E, Aronica E, Iyer A, Adle-Biassette H, Scharrer A, Reischer T, Hainfellner JA, Kovacs GG. The physiological phosphorylation of tau is critically changed in fetal brains of individuals with Down syndrome. Neuropathol Appl Neurobiol 2017; 44:314-327. [PMID: 28455903 DOI: 10.1111/nan.12406] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Revised: 03/17/2017] [Accepted: 04/15/2017] [Indexed: 01/15/2023]
Abstract
AIMS Down syndrome (DS) is a common cause of mental retardation accompanied by cognitive impairment. Comprehensive studies suggested a link between development and ageing, as nearly all individuals with DS develop Alzheimer disease (AD)-like pathology. However, there is still a paucity of data on tau in early DS to support this notion. METHODS Using morphometric immunohistochemistry we compared tau phosphorylation in normal brains and in brains of individuals with DS from early development until early postnatal life. RESULTS We observed in DS a critical loss of physiological phosphorylation of tau. Rhombencephalic structures showed prominent differences between controls and DS using antibodies AT8 (Ser-202/Thr-205) and AT180 (Thr-231). In contrast, in the subiculum only a small portion of controls deviated from DS using antibodies AT100 (Thr-212/Ser-214) and AT270 (Thr-181). With exception of the subiculum, phosphorylation-independent tau did not differ between groups, as confirmed by immunostaining for the HT-7 antibody (epitope between 159 and 163 of the human tau) as well. DISCUSSION Our observations suggest functional tau disturbance in DS brains during development, rather than axonal loss. This supports the role of tau as a further important player in the pathophysiology of cognitive impairment in DS and related AD.
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Affiliation(s)
- I Milenkovic
- Department of Neurology, Medical University of Vienna, Vienna, Austria.,Institute of Neurology, Neurodegeneration Research Group, Medical University of Vienna, Vienna, Austria
| | - J Jarc
- Institute of Neurology, Neurodegeneration Research Group, Medical University of Vienna, Vienna, Austria
| | - E Dassler
- Institute of Neurology, Neurodegeneration Research Group, Medical University of Vienna, Vienna, Austria
| | - E Aronica
- Department of (Neuro)Pathology, Academic Medical Center, University of Amsterdam, The Netherlands.,SEIN - Stichting Epilepsie Instellingen Nederland, Heemstede, The Netherlands.,Swammerdam Institute for Life Sciences, Center for Neuroscience, University of Amsterdam, The Netherlands
| | - A Iyer
- Department of (Neuro)Pathology, Academic Medical Center, University of Amsterdam, The Netherlands
| | - H Adle-Biassette
- Inserm U1141, Paris, France.,Univ Paris Diderot, Sorbonne Paris Cité, UMRS 676, Paris, France.,Lariboisière Hospital, APHP, Paris, France
| | - A Scharrer
- Department of Pathology, Medical University of Vienna, Vienna, Austria
| | - T Reischer
- Department of Obstetrics and Gynecology, Medical University of Vienna, Vienna, Austria
| | - J A Hainfellner
- Institute of Neurology, Neurodegeneration Research Group, Medical University of Vienna, Vienna, Austria
| | - G G Kovacs
- Institute of Neurology, Neurodegeneration Research Group, Medical University of Vienna, Vienna, Austria
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49
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Agadjanyan MG, Zagorski K, Petrushina I, Davtyan H, Kazarian K, Antonenko M, Davis J, Bon C, Blurton-Jones M, Cribbs DH, Ghochikyan A. Humanized monoclonal antibody armanezumab specific to N-terminus of pathological tau: characterization and therapeutic potency. Mol Neurodegener 2017; 12:33. [PMID: 28472993 PMCID: PMC5418694 DOI: 10.1186/s13024-017-0172-1] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Accepted: 04/07/2017] [Indexed: 01/01/2023] Open
Abstract
Background The experience from clinical trials indicates that anti-Aβ immunotherapy could be effective in early/pre-clinical stages of AD, whereas at the late stages promoting the clearing of Aβ alone may be insufficient to halt the disease progression. At the same time, pathological tau correlates much better with the degree of dementia than Aβ deposition. Therefore, targeting pathological tau may provide a more promising approach for the treatment of advanced stages of AD. Recent data demonstrates that the N-terminal region of tau spanning aa 2–18 termed “phosphatase activation domain” that is normally hidden in the native protein in ‘paperclip’-like conformation, becomes exposed in pathological tau and plays an essential role in the inhibition of fast axonal transport and in aggregation of tau. Hence, we hypothesized that anti-Tau2–18 monoclonal antibodies (mAb) may recognize pathological, but not normal tau at very early stages of tauopathy and prevent or decrease the aggregation of this molecule. Methods Mouse mAbs were generated using standard hybridoma methodology. CDR grafting was used for humanization of mouse mAb. Humanized mAb (Armanezumab) was characterized and tested in vitro/ex vivo/in vivo using biochemical and immunological methods (HPLC, Biacore, ELISA, IHC, FRET, etc.). Stable DG44 cell line expressing Armanezumab was generated by clone selection with increased concentrations of methotrexate (MTX). Results A panel of mouse mAbs was generated, clone 1C9 was selected based on binding to pathological human tau with high affinity and humanized. Fine epitope mapping revealed conservation of the epitope of human tau recognized by the parent murine mAb and Armanezumab. Importantly, Armanezumab (i) bound to tau with high affinity as determined by Biacore; (ii) bound pathological tau in brains from AD, FTD and Pick’s disease cases; (iii) inhibited seeding effect of aggregated tau from brain lysate of P301S Tg mice; (iv) inhibited cytotoxic effect of tau oligomers; (v) reduced total tau (HT7) and AT100, PHF1, AT8, AT180, p212, p214-positive tau species in brains of tau transgenic mice after intracranial injection. A stable CHO cell line producing >1.5 g/l humanized mAb, Armanezumab was generated. Conclusion These findings suggest that Armanezumab could be therapeutic in clinical studies for treatment of AD.
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Affiliation(s)
- Michael G Agadjanyan
- Department of Molecular Immunology, Institute for Molecular Medicine, 16371 Gothard St, Huntington Beach, CA, 92647, USA. .,The Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, Irvine, CA, 92697, USA.
| | - Karen Zagorski
- Department of Molecular Immunology, Institute for Molecular Medicine, 16371 Gothard St, Huntington Beach, CA, 92647, USA.,Department of Pharmaceutical Sciences, University of Nebraska Medical Center, Omaha, NE, 68198-6025, USA
| | - Irina Petrushina
- The Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, Irvine, CA, 92697, USA
| | - Hayk Davtyan
- Department of Molecular Immunology, Institute for Molecular Medicine, 16371 Gothard St, Huntington Beach, CA, 92647, USA
| | - Konstantin Kazarian
- Department of Molecular Immunology, Institute for Molecular Medicine, 16371 Gothard St, Huntington Beach, CA, 92647, USA
| | - Maxim Antonenko
- Department of Molecular Immunology, Institute for Molecular Medicine, 16371 Gothard St, Huntington Beach, CA, 92647, USA
| | - Joy Davis
- Sue and Bill Gross Stem Cell Research Center, University of California, Irvine, Irvine, CA, 92697, USA
| | | | - Mathew Blurton-Jones
- The Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, Irvine, CA, 92697, USA.,Sue and Bill Gross Stem Cell Research Center, University of California, Irvine, Irvine, CA, 92697, USA
| | - David H Cribbs
- The Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, Irvine, CA, 92697, USA
| | - Anahit Ghochikyan
- Department of Molecular Immunology, Institute for Molecular Medicine, 16371 Gothard St, Huntington Beach, CA, 92647, USA.
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50
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Guo T, Noble W, Hanger DP. Roles of tau protein in health and disease. Acta Neuropathol 2017; 133:665-704. [PMID: 28386764 PMCID: PMC5390006 DOI: 10.1007/s00401-017-1707-9] [Citation(s) in RCA: 546] [Impact Index Per Article: 78.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Revised: 03/26/2017] [Accepted: 03/26/2017] [Indexed: 01/18/2023]
Abstract
Tau is well established as a microtubule-associated protein in neurons. However, under pathological conditions, aberrant assembly of tau into insoluble aggregates is accompanied by synaptic dysfunction and neural cell death in a range of neurodegenerative disorders, collectively referred to as tauopathies. Recent advances in our understanding of the multiple functions and different locations of tau inside and outside neurons have revealed novel insights into its importance in a diverse range of molecular pathways including cell signalling, synaptic plasticity, and regulation of genomic stability. The present review describes the physiological and pathophysiological properties of tau and how these relate to its distribution and functions in neurons. We highlight the post-translational modifications of tau, which are pivotal in defining and modulating tau localisation and its roles in health and disease. We include discussion of other pathologically relevant changes in tau, including mutation and aggregation, and how these aspects impinge on the propensity of tau to propagate, and potentially drive neuronal loss, in diseased brain. Finally, we describe the cascade of pathological events that may be driven by tau dysfunction, including impaired axonal transport, alterations in synapse and mitochondrial function, activation of the unfolded protein response and defective protein degradation. It is important to fully understand the range of neuronal functions attributed to tau, since this will provide vital information on its involvement in the development and pathogenesis of disease. Such knowledge will enable determination of which critical molecular pathways should be targeted by potential therapeutic agents developed for the treatment of tauopathies.
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Affiliation(s)
- Tong Guo
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, SE5 9NU, UK
| | - Wendy Noble
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, SE5 9NU, UK
| | - Diane P Hanger
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, SE5 9NU, UK.
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