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Zhang YL, Jia SY, Yang B, Miao J, Su C, Cui ZG, Yang LM, Guo JH. Non-linear association of liver enzymes with cognitive performance in the elderly: A cross-sectional study. PLoS One 2024; 19:e0306839. [PMID: 39042647 PMCID: PMC11265699 DOI: 10.1371/journal.pone.0306839] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2024] [Accepted: 06/23/2024] [Indexed: 07/25/2024] Open
Abstract
BACKGROUND Although liver metabolic dysfunction has been found to potentially elevate susceptibility to cognitive impairment and dementia, there is still insufficient evidence to explore the non-linear association of liver enzymes with cognitive performance. Therefore, we aimed to elucidate the non-linear relationship between liver enzymes and cognitive performance. METHODS In this cross-sectional study, 2764 individuals aged ≥ 60 who participated in the National Health and Nutrition Survey (NHANES) between 2011 and 2014 were included. The primary data comprised liver enzyme levels (alkaline phosphatase (ALP), aspartate aminotransferase (AST), alanine aminotransferase (ALT), AST/ALT ratio, and gamma-glutamyl transferase (GGT)), and cognitive performance was the major measured outcome. The associations were analyzed using weighted multivariate logistic regression, subgroup analysis, a generalized additive model, smooth fitting curves, and threshold effects. RESULTS The results of the fully adjusted model indicated that ALP was negatively associated with the animal fluency test (AFT) score (OR = 1.48, 95% CI: 1.11-1.98), whereas ALT demonstrated a positive association with the consortium to establish a registry for Alzheimer's disease (CERAD) test score (OR = 0.72, 95% CI: 0.53-0.97). Additionally, the AST/ALT ratio was negatively associated with the global cognitive test (OR = 2.39, 95% CI: 1.53-3.73), CERAD (OR = 2.61, 95% CI: 1.77-3.84), and digit symbol substitution test (DSST) scores (OR = 2.51, 95% CI: 1.57-4.02). GGT was also negatively associated with the AFT score (OR = 1.16, 95% CI: 1.01-1.33) in unadjusted model. A non-linear relationship was observed between liver enzymes and the risk of cognitive impairment as assessed by the global cognitive test. Specifically, when ALP > 60 U/L, 0.77 < AST/ALT < 1.76, and 25 < GGT < 94 U/L, higher liver enzyme levels were significantly associated with an elevated cognitive impairment risk, while a lower cognitive impairment risk when ALT level was > 17 U/L. CONCLUSIONS There is a non-linear relationship between liver enzymes and cognitive performance, indicating that liver enzyme levels should be maintained within a certain level to mitigate the risk of cognitive impairment.
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Affiliation(s)
- Yan-Li Zhang
- Department of Neurological Intensive Care Unit, Sixth Hospital of Shanxi Medical University (General Hospital of Tisco), Taiyuan, Shanxi, China
| | - Shi-Ying Jia
- Department of Neurology, First Hospital of Shanxi Medical University, Taiyuan, Shanxi, China
| | - Bo Yang
- Department of Hernia and Abdominal Wall Surgery, Shanxi Bethune Hospital, Shanxi Academy of Medical Sciences, Tongji Shanxi Hospital, Third Hospital of Shanxi Medical University, Taiyuan, Shanxi, China
| | - Jie Miao
- Department of Neurology, First Hospital of Shanxi Medical University, Taiyuan, Shanxi, China
| | - Chen Su
- Department of Neurology, First Hospital of Shanxi Medical University, Taiyuan, Shanxi, China
| | - Zhi-Gang Cui
- Department of Neurology, The Third People’s Hospital of Datong, Datong, Shanxi, China
| | - Li-Ming Yang
- Department of Neurological Intensive Care Unit, Sixth Hospital of Shanxi Medical University (General Hospital of Tisco), Taiyuan, Shanxi, China
| | - Jun-Hong Guo
- Department of Neurology, First Hospital of Shanxi Medical University, Taiyuan, Shanxi, China
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2
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Otake M, Teranishi M, Komatsu C, Hara M, Yoshiyama KO, Hidema J. Poaceae plants transfer cyclobutane pyrimidine dimer photolyase to chloroplasts for ultraviolet-B resistance. PLANT PHYSIOLOGY 2024; 195:326-342. [PMID: 38345835 PMCID: PMC11060685 DOI: 10.1093/plphys/kiae060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Accepted: 01/07/2024] [Indexed: 05/02/2024]
Abstract
Photoreactivation enzyme that repairs cyclobutane pyrimidine dimer (CPD) induced by ultraviolet-B radiation, commonly called CPD photolyase (PHR) is essential for plants living under sunlight. Rice (Oryza sativa) PHR (OsPHR) is a unique triple-targeting protein. The signal sequences required for its translocation to the nucleus or mitochondria are located in the C-terminal region but have yet to be identified for chloroplasts. Here, we identified sequences located in the N-terminal region, including the serine-phosphorylation site at position 7 of OsPHR, and found that OsPHR is transported/localized to chloroplasts via a vesicle transport system under the control of serine-phosphorylation. However, the sequence identified in this study is only conserved in some Poaceae species, and in many other plants, PHR is not localized to the chloroplasts. Therefore, we reasoned that Poaceae species need the ability to repair CPD in the chloroplast genome to survive under sunlight and have uniquely acquired this mechanism for PHR chloroplast translocation.
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Affiliation(s)
- Momo Otake
- Graduate School of Life Sciences, Tohoku University, Sendai 980-8577, Japan
| | - Mika Teranishi
- Graduate School of Life Sciences, Tohoku University, Sendai 980-8577, Japan
| | - Chiharu Komatsu
- Graduate School of Life Sciences, Tohoku University, Sendai 980-8577, Japan
| | - Mamoru Hara
- Graduate School of Life Sciences, Tohoku University, Sendai 980-8577, Japan
| | | | - Jun Hidema
- Graduate School of Life Sciences, Tohoku University, Sendai 980-8577, Japan
- Division for the Establishment of Frontier Sciences of the Organization for Advanced Studies, Tohoku University, Sendai, Miyagi 980-8577, Japan
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3
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Younas N, Saleem T, Younas A, Zerr I. Nuclear face of Tau: an inside player in neurodegeneration. Acta Neuropathol Commun 2023; 11:196. [PMID: 38087392 PMCID: PMC10714511 DOI: 10.1186/s40478-023-01702-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2023] [Accepted: 11/29/2023] [Indexed: 12/18/2023] Open
Abstract
Tau (Tubulin associated unit) protein is a major hallmark of Alzheimer's disease (AD) and tauopathies. Tau is predominantly an axonal protein with a crucial role in the stabilization and dynamics of the microtubules. Since the discovery of Tau protein in 1975, research efforts were concentrated on the pathophysiological role of Tau protein in the context of the microtubules. Although, for more than three decades, different localizations of Tau protein have been discovered e.g., in the nuclear compartments. Discovery of the role of Tau protein in various cellular compartments especially in the nucleus opens up a new fold of complexity in tauopathies. Data from cellular models, animal models, and the human brain indicate that nuclear Tau is crucial for genome stability and to cope with cellular distress. Moreover, it's nature of nuclear translocation, its interactions with the nuclear DNA/RNA and proteins suggest it could play multiple roles in the nucleus. To comprehend Tau pathophysiology and efficient Tau-based therapies, there is an urgent need to understand whole repertoire of Tau species (nuclear and cytoplasmic) and their functional relevance. To complete the map of Tau repertoire, understanding of various species of Tau in the nucleus and cytoplasm, identification if specific transcripts of Tau, isoforms and post-translational modifications could foretell Tau's localizations and functions, and how they are modified in neurodegenerative diseases like AD, is urgently required. In this review, we explore the nuclear face of Tau protein, its nuclear localizations and functions and its linkage with Alzheimer's disease.
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Affiliation(s)
- Neelam Younas
- University Medical Center Göttingen, National Reference Center for Surveillance of TSE, Department of Neurology, Robert-Koch strasse 40, 37075, Göttingen, Germany.
- German Center for Neurodegenerative Diseases (DZNE), Göttingen, 37075, Germany.
| | - Tayyaba Saleem
- University Medical Center Göttingen, National Reference Center for Surveillance of TSE, Department of Neurology, Robert-Koch strasse 40, 37075, Göttingen, Germany
- German Center for Neurodegenerative Diseases (DZNE), Göttingen, 37075, Germany
| | - Abrar Younas
- University Medical Center Göttingen, National Reference Center for Surveillance of TSE, Department of Neurology, Robert-Koch strasse 40, 37075, Göttingen, Germany
- German Center for Neurodegenerative Diseases (DZNE), Göttingen, 37075, Germany
| | - Inga Zerr
- University Medical Center Göttingen, National Reference Center for Surveillance of TSE, Department of Neurology, Robert-Koch strasse 40, 37075, Göttingen, Germany
- German Center for Neurodegenerative Diseases (DZNE), Göttingen, 37075, Germany
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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: 7] [Impact Index Per Article: 7.0] [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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MacAinsh M, Zhou H. Partial mimicry of the microtubule binding of tau by its membrane binding. Protein Sci 2023; 32:e4581. [PMID: 36710643 PMCID: PMC9926470 DOI: 10.1002/pro.4581] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Revised: 01/10/2023] [Accepted: 01/26/2023] [Indexed: 01/31/2023]
Abstract
Tau, as typical of intrinsically disordered proteins (IDPs), binds to multiple targets including microtubules and acidic membranes. The latter two surfaces are both highly negatively charged, raising the prospect of mimicry in their binding by tau. The tau-microtubule complex was recently determined by cryo-electron microscopy. Here, we used molecular dynamics simulations to characterize the dynamic binding of tau K19 to an acidic membrane. This IDP can be divided into three repeats, each containing an amphipathic helix. The three amphipathic helices, along with flanking residues, tether the protein to the membrane interface. The separation between and membrane positioning of the amphipathic helices in the simulations are validated by published EPR data. The membrane contact probabilities of individual residues in tau show both similarities to and distinctions from native contacts with microtubules. In particular, a Lys that is conserved among the repeats forms similar interactions with membranes and with microtubules, as does a conserved Val. This partial mimicry facilitates both the membrane anchoring of microtubules by tau and the transfer of tau from membranes to microtubules.
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Affiliation(s)
- Matthew MacAinsh
- Department of ChemistryUniversity of Illinois at ChicagoChicagoIllinoisUSA
| | - Huan‐Xiang Zhou
- Department of ChemistryUniversity of Illinois at ChicagoChicagoIllinoisUSA
- Department of PhysicsUniversity of Illinois at ChicagoChicagoIllinoisUSA
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6
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Mahakud AK, Shaikh J, Rifa Iqbal VV, Gupta A, Tiwari A, Saleem M. Amyloids on Membrane Interfaces: Implications for Neurodegeneration. J Membr Biol 2022; 255:705-722. [PMID: 35670831 DOI: 10.1007/s00232-022-00245-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Accepted: 05/12/2022] [Indexed: 12/24/2022]
Abstract
Membrane interfaces are vital for various cellular processes, and their involvement in neurodegenerative disorders such as Alzheimer's and Parkinson's disease has taken precedence in recent years. The amyloidogenic proteins associated with neurodegenerative diseases interact with the neuronal membrane through various means, which has implications for both the onset and progression of the disease. The parameters that regulate the interaction between the membrane and the amyloids remain poorly understood. The review focuses on the various aspects of membrane interactions of amyloids, particularly amyloid-β (Aβ) peptides and Tau involved in Alzheimer's and α-synuclein involved in Parkinson's disease. The genetic, cell biological, biochemical, and biophysical studies that form the basis for our current understanding of the membrane interactions of Aβ peptides, Tau, and α-synuclein are discussed.
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Affiliation(s)
- Amaresh Kumar Mahakud
- School of Biological Sciences, National Institute of Science Education and Research, Bhubaneswar, India.,Homi Bhabha National Institute, Mumbai, India
| | - Jafarulla Shaikh
- School of Biological Sciences, National Institute of Science Education and Research, Bhubaneswar, India.,Homi Bhabha National Institute, Mumbai, India
| | - V V Rifa Iqbal
- School of Biological Sciences, National Institute of Science Education and Research, Bhubaneswar, India.,Homi Bhabha National Institute, Mumbai, India
| | - Abhinav Gupta
- School of Biological Sciences, National Institute of Science Education and Research, Bhubaneswar, India.,Homi Bhabha National Institute, Mumbai, India
| | - Anuj Tiwari
- Department of Life Sciences, National Institute of Technology, Rourkela, India
| | - Mohammed Saleem
- School of Biological Sciences, National Institute of Science Education and Research, Bhubaneswar, India. .,Homi Bhabha National Institute, Mumbai, India.
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7
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Yao QQ, Wen J, Perrett S, Wu S. Distinct lipid membrane-mediated pathways of Tau assembly revealed by single-molecule analysis. NANOSCALE 2022; 14:4604-4613. [PMID: 35260870 DOI: 10.1039/d1nr05960b] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
The conversion of intrinsically disordered Tau to highly ordered amyloid aggregates is associated with a wide range of neurodegenerative diseases termed tauopathies. The presence of lipid bilayer membranes is a critical factor that accelerates the abnormal aggregation of Tau protein. However, the lipid membrane-induced conformational changes of Tau and the mechanism for the accelerated fibrillation remain elusive. In this study, single-molecule Förster resonance energy transfer (smFRET) and fluorescence correlation spectroscopy (FCS) were applied to detect the conformational changes and intermolecular interactions of full-length Tau in the presence of different concentrations of 1,2-dimyristoyl-sn-glycero-3-phosphatidylserine (DMPS) vesicles. The results show that the conformation of Tau becomes expanded with opening of the N-terminal and C-terminal domains of Tau upon binding to DMPS. At low DMPS concentrations, Tau forms oligomers with a partially extended conformation which facilitates the amyloid fibrillization process. At high DMPS concentrations, Tau monomer binds to lipid membranes in a fully expanded conformation at low density thus inhibiting intermolecular aggregation. Our study reveals the underlying mechanisms by which lipid membranes influence amyloid formation of Tau, providing a foundation for further understanding of the pathogenesis and physiology of the interplay between Tau protein and lipid membranes.
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Affiliation(s)
- Qiong-Qiong Yao
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Chaoyang District, Beijing 100101, China.
- University of the Chinese Academy of Sciences, 19A Yuquan Road, Shijingshan District, Beijing 100049, China
| | - Jitao Wen
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Chaoyang District, Beijing 100101, China.
- University of the Chinese Academy of Sciences, 19A Yuquan Road, Shijingshan District, Beijing 100049, China
| | - Sarah Perrett
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Chaoyang District, Beijing 100101, China.
- University of the Chinese Academy of Sciences, 19A Yuquan Road, Shijingshan District, Beijing 100049, China
| | - Si Wu
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Chaoyang District, Beijing 100101, China.
- University of the Chinese Academy of Sciences, 19A Yuquan Road, Shijingshan District, Beijing 100049, China
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8
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Ruiz-Gabarre D, Carnero-Espejo A, Ávila J, García-Escudero V. What's in a Gene? The Outstanding Diversity of MAPT. Cells 2022; 11:840. [PMID: 35269461 PMCID: PMC8909800 DOI: 10.3390/cells11050840] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Revised: 02/25/2022] [Accepted: 02/27/2022] [Indexed: 02/04/2023] Open
Abstract
Tau protein is a microtubule-associated protein encoded by the MAPT gene that carries out a myriad of physiological functions and has been linked to certain pathologies collectively termed tauopathies, including Alzheimer's disease, frontotemporal dementia, Huntington's disease, progressive supranuclear palsy, etc. Alternative splicing is a physiological process by which cells generate several transcripts from one single gene and may in turn give rise to different proteins from the same gene. MAPT transcripts have been proven to be subjected to alternative splicing, generating six main isoforms in the central nervous system. Research throughout the years has demonstrated that the splicing landscape of the MAPT gene is far more complex than that, including at least exon skipping events, the use of 3' and 5' alternative splice sites and, as has been recently discovered, also intron retention. In addition, MAPT alternative splicing has been showed to be regulated spatially and developmentally, further evidencing the complexity of the gene's splicing regulation. It is unclear what would drive the need for the existence of so many isoforms encoded by the same gene, but a wide range of functions have been ascribed to these Tau isoforms, both in physiology and pathology. In this review we offer a comprehensive up-to-date exploration of the mechanisms leading to the outstanding diversity of isoforms expressed from the MAPT gene and the functions in which such isoforms are involved, including their potential role in the onset and development of tauopathies such as Alzheimer's disease.
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Affiliation(s)
- Daniel Ruiz-Gabarre
- Anatomy, Histology and Neuroscience Department, School of Medicine, Universidad Autónoma de Madrid (UAM), 28029 Madrid, Spain; (D.R.-G.); (A.C.-E.)
- Centro de Biología Molecular Severo Ochoa (UAM-CSIC), 28049 Madrid, Spain
- Graduate Program in Neuroscience, Universidad Autónoma de Madrid (UAM), 28029 Madrid, Spain
| | - Almudena Carnero-Espejo
- Anatomy, Histology and Neuroscience Department, School of Medicine, Universidad Autónoma de Madrid (UAM), 28029 Madrid, Spain; (D.R.-G.); (A.C.-E.)
- Graduate Program in Neuroscience, Universidad Autónoma de Madrid (UAM), 28029 Madrid, Spain
| | - Jesús Ávila
- Centro de Biología Molecular Severo Ochoa (UAM-CSIC), 28049 Madrid, Spain
- Networking Research Center on Neurodegenerative Diseases (CIBERNED), Instituto de Salud Carlos III, 28031 Madrid, Spain
| | - Vega García-Escudero
- Anatomy, Histology and Neuroscience Department, School of Medicine, Universidad Autónoma de Madrid (UAM), 28029 Madrid, Spain; (D.R.-G.); (A.C.-E.)
- Centro de Biología Molecular Severo Ochoa (UAM-CSIC), 28049 Madrid, Spain
- Graduate Program in Neuroscience, Universidad Autónoma de Madrid (UAM), 28029 Madrid, Spain
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9
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Carroll T, Guha S, Nehrke K, Johnson GVW. Tau Post-Translational Modifications: Potentiators of Selective Vulnerability in Sporadic Alzheimer's Disease. BIOLOGY 2021; 10:1047. [PMID: 34681146 PMCID: PMC8533264 DOI: 10.3390/biology10101047] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Revised: 10/08/2021] [Accepted: 10/13/2021] [Indexed: 12/14/2022]
Abstract
Sporadic Alzheimer's Disease (AD) is the most common form of dementia, and its severity is characterized by the progressive formation of tau neurofibrillary tangles along a well-described path through the brain. This spatial progression provides the basis for Braak staging of the pathological progression for AD. Tau protein is a necessary component of AD pathology, and recent studies have found that soluble tau species with selectively, but not extensively, modified epitopes accumulate along the path of disease progression before AD-associated insoluble aggregates form. As such, modified tau may represent a key cellular stressing agent that potentiates selective vulnerability in susceptible neurons during AD progression. Specifically, studies have found that tau phosphorylated at sites such as T181, T231, and S396 may initiate early pathological changes in tau by disrupting proper tau localization, initiating tau oligomerization, and facilitating tau accumulation and extracellular export. Thus, this review elucidates potential mechanisms through which tau post-translational modifications (PTMs) may simultaneously serve as key modulators of the spatial progression observed in AD development and as key instigators of early pathology related to neurodegeneration-relevant cellular dysfunctions.
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Affiliation(s)
- Trae Carroll
- Department of Pathology, University of Rochester Medical Center (URMC), Rochester, NY 14642, USA;
| | - Sanjib Guha
- Department of Anesthesiology and Perioperative Medicine, University of Rochester Medical Center (URMC), Rochester, NY 14642, USA;
| | - Keith Nehrke
- Department of Medicine, Nephrology Division, University of Rochester Medical Center (URMC), Rochester, NY 14642, USA;
| | - Gail V. W. Johnson
- Department of Anesthesiology and Perioperative Medicine, University of Rochester Medical Center (URMC), Rochester, NY 14642, USA;
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10
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Do Carmo S, Spillantini MG, Cuello AC. Editorial: Tau Pathology in Neurological Disorders. Front Neurol 2021; 12:754669. [PMID: 34630315 PMCID: PMC8497747 DOI: 10.3389/fneur.2021.754669] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Accepted: 08/26/2021] [Indexed: 12/27/2022] Open
Affiliation(s)
- Sonia Do Carmo
- Department of Pharmacology and Therapeutics, McGill University, Montreal, QC, Canada
| | - Maria Grazia Spillantini
- Department of Clinical Neurosciences, Clifford Allbutt Building, University of Cambridge, Cambridge, United Kingdom
| | - A Claudio Cuello
- Department of Pharmacology and Therapeutics, McGill University, Montreal, QC, Canada.,Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada.,Department of Anatomy and Cell Biology, McGill University, Montreal, QC, Canada.,Department of Pharmacology, Oxford University, Oxford, United Kingdom
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11
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Loh D, Reiter RJ. Melatonin: Regulation of Biomolecular Condensates in Neurodegenerative Disorders. Antioxidants (Basel) 2021; 10:1483. [PMID: 34573116 PMCID: PMC8465482 DOI: 10.3390/antiox10091483] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Revised: 09/10/2021] [Accepted: 09/13/2021] [Indexed: 12/12/2022] Open
Abstract
Biomolecular condensates are membraneless organelles (MLOs) that form dynamic, chemically distinct subcellular compartments organizing macromolecules such as proteins, RNA, and DNA in unicellular prokaryotic bacteria and complex eukaryotic cells. Separated from surrounding environments, MLOs in the nucleoplasm, cytoplasm, and mitochondria assemble by liquid-liquid phase separation (LLPS) into transient, non-static, liquid-like droplets that regulate essential molecular functions. LLPS is primarily controlled by post-translational modifications (PTMs) that fine-tune the balance between attractive and repulsive charge states and/or binding motifs of proteins. Aberrant phase separation due to dysregulated membrane lipid rafts and/or PTMs, as well as the absence of adequate hydrotropic small molecules such as ATP, or the presence of specific RNA proteins can cause pathological protein aggregation in neurodegenerative disorders. Melatonin may exert a dominant influence over phase separation in biomolecular condensates by optimizing membrane and MLO interdependent reactions through stabilizing lipid raft domains, reducing line tension, and maintaining negative membrane curvature and fluidity. As a potent antioxidant, melatonin protects cardiolipin and other membrane lipids from peroxidation cascades, supporting protein trafficking, signaling, ion channel activities, and ATPase functionality during condensate coacervation or dissolution. Melatonin may even control condensate LLPS through PTM and balance mRNA- and RNA-binding protein composition by regulating N6-methyladenosine (m6A) modifications. There is currently a lack of pharmaceuticals targeting neurodegenerative disorders via the regulation of phase separation. The potential of melatonin in the modulation of biomolecular condensate in the attenuation of aberrant condensate aggregation in neurodegenerative disorders is discussed in this review.
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Affiliation(s)
- Doris Loh
- Independent Researcher, Marble Falls, TX 78654, USA
| | - Russel J. Reiter
- Department of Cellular and Structural Biology, UT Health Science Center, San Antonio, TX 78229, USA
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12
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Gaunitz S, Tjernberg LO, Schedin-Weiss S. What Can N-glycomics and N-glycoproteomics of Cerebrospinal Fluid Tell Us about Alzheimer Disease? Biomolecules 2021; 11:858. [PMID: 34207636 PMCID: PMC8226827 DOI: 10.3390/biom11060858] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Revised: 05/28/2021] [Accepted: 06/04/2021] [Indexed: 12/18/2022] Open
Abstract
Proteomics-large-scale studies of proteins-has over the last decade gained an enormous interest for studies aimed at revealing proteins and pathways involved in disease. To fully understand biological and pathological processes it is crucial to also include post-translational modifications in the "omics". To this end, glycomics (identification and quantification of glycans enzymatically or chemically released from proteins) and glycoproteomics (identification and quantification of peptides/proteins with the glycans still attached) is gaining interest. The study of protein glycosylation requires a workflow that involves an array of sample preparation and analysis steps that needs to be carefully considered. Herein, we briefly touch upon important steps such as sample preparation and preconcentration, glycan release, glycan derivatization and quantification and advances in mass spectrometry that today are the work-horse for glycomics and glycoproteomics studies. Several proteins related to Alzheimer disease pathogenesis have altered protein glycosylation, and recent glycomics studies have shown differences in cerebrospinal fluid as well as in brain tissue in Alzheimer disease as compared to controls. In this review, we discuss these techniques and how they have been used to shed light on Alzheimer disease and to find glycan biomarkers in cerebrospinal fluid.
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Affiliation(s)
- Stefan Gaunitz
- Department of Clinical Chemistry, Karolinska University Hospital, 14186 Stockholm, Sweden;
| | - Lars O. Tjernberg
- Division of Neurogeriatrics, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, 17164 Solna, Sweden;
| | - Sophia Schedin-Weiss
- Division of Neurogeriatrics, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, 17164 Solna, Sweden;
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13
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Flores-Rodríguez P, Harrington CR, Wischik CM, Ibarra-Bracamontes V, Zarco N, Navarrete A, Martínez-Maldonado A, Guadarrama-Ortíz P, Villanueva-Fierro I, Ontiveros-Torres MA, Perry G, Alonso AD, Floran-Garduño B, Segovia J, Luna-Muñoz J. Phospho-Tau Protein Expression in the Cell Cycle of SH-SY5Y Neuroblastoma Cells: A Morphological Study. J Alzheimers Dis 2020; 71:631-645. [PMID: 31424392 DOI: 10.3233/jad-190155] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
It has been reported that the main function of tau protein is to stabilize microtubules and promote the movement of organelles through the axon in neurons. In Alzheimer's disease, tau protein is the major constituent of the paired helical filament, and it undergoes post-translational modifications including hyperphosphorylation and truncation. Whether other functions of tau protein are involved in Alzheimer's disease is less clear. We used SH-SY5Y human neuroblastoma cells as an in vitro model to further study the functions of tau protein. We detected phosphorylated tau protein as small dense dots in the cell nucleus, which strongly colocalize with intranuclear speckle structures that were also labelled with an antibody to SC35, a protein involved in nuclear RNA splicing. We have shown further that tau protein, phosphorylated at the sites recognized by pT231, TG-3, and AD2 antibodies, is closely associated with cell division. Different functions may be characteristic of phosphorylation at specific sites. Our findings suggest that the presence of tau protein is involved in separation of sister chromatids in anaphase, and that tau protein also participates in maintaining the integrity of the DNA (pT231, prophase) and chromosomes during cell division (TG-3).
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Affiliation(s)
- Paola Flores-Rodríguez
- Deparment of Physiology, Biophysics and Neuroscience, CINVESTAV, CDMX, México.,Brain Bank, Laboratorio Nacional de Servicios Experimentales, LaNSE-CINVESTAV, CDMX, México.,CIIDIR Durango, Instituto Politécnico Nacional, Becario COFAA, Durango, México
| | - Charles R Harrington
- School of Medicine, Medical Sciences and Nutrition, University of Aberdeen, Aberdeen, UK
| | - Claude M Wischik
- School of Medicine, Medical Sciences and Nutrition, University of Aberdeen, Aberdeen, UK
| | - Vanessa Ibarra-Bracamontes
- Deparment of Physiology, Biophysics and Neuroscience, CINVESTAV, CDMX, México.,Brain Bank, Laboratorio Nacional de Servicios Experimentales, LaNSE-CINVESTAV, CDMX, México
| | - Natanael Zarco
- Deparment of Physiology, Biophysics and Neuroscience, CINVESTAV, CDMX, México
| | - Araceli Navarrete
- Deparment of Physiology, Biophysics and Neuroscience, CINVESTAV, CDMX, México
| | - Alejandra Martínez-Maldonado
- Deparment of Physiology, Biophysics and Neuroscience, CINVESTAV, CDMX, México.,Anahuac University North Mexico, CDMX, México
| | | | | | | | - George Perry
- College of Sciences, University of Texas at San Antonio, TX, USA
| | - Alejandra D Alonso
- Biology Department and Center for Developmental Neuroscience, College of Staten Island, The City University of New York, Staten Island, NY, USA
| | | | - José Segovia
- Deparment of Physiology, Biophysics and Neuroscience, CINVESTAV, CDMX, México
| | - José Luna-Muñoz
- Brain Bank, Laboratorio Nacional de Servicios Experimentales, LaNSE-CINVESTAV, CDMX, México
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14
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Electrostatics of Tau Protein by Molecular Dynamics. Biomolecules 2019; 9:biom9030116. [PMID: 30909607 PMCID: PMC6468555 DOI: 10.3390/biom9030116] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Revised: 03/19/2019] [Accepted: 03/20/2019] [Indexed: 12/25/2022] Open
Abstract
Tau is a microtubule-associated protein that promotes microtubule assembly and stability. This protein is implicated in several neurodegenerative diseases, including Alzheimer’s. To date, the three-dimensional (3D) structure of tau has not been fully solved, experimentally. Even the most recent information is sometimes controversial in regard to how this protein folds, interacts, and behaves. Predicting the tau structure and its profile sheds light on the knowledge about its properties and biological function, such as the binding to microtubules (MT) and, for instance, the effect on ionic conductivity. Our findings on the tau structure suggest a disordered protein, with discrete portions of well-defined secondary structure, mostly at the microtubule binding region. In addition, the first molecular dynamics simulation of full-length tau along with an MT section was performed, unveiling tau structure when associated with MT and interaction sites. Electrostatics and conductivity were also examined to understand how tau affects the ions in the intracellular fluid environment. Our results bring a new insight into tau and tubulin MT proteins, their characteristics, and the structure–function relationship.
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15
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Sotiropoulos I, Silva JM, Gomes P, Sousa N, Almeida OFX. Stress and the Etiopathogenesis of Alzheimer's Disease and Depression. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1184:241-257. [PMID: 32096043 DOI: 10.1007/978-981-32-9358-8_20] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Alzheimer's disease (AD) is a multifactorial neurodegenerative disorder with a complex physiopathology whose initiators are poorly defined. Accumulating clinical and experimental evidence suggests a causal role of lifetime stress in AD. This chapter summarizes current knowledge about how chronic stress and its accompanying high levels of glucocorticoid (GC) secretion, trigger the two main pathomechanisms of AD: (i) misprocessing of amyloid precursor protein (APP) and the generation of amyloid beta (Aβ) and (ii) Tau hyperphosphorylation and aggregation. Given that depression is a well-known stress-related illness, and the evidence that depression may precede AD, this chapter also explores neurobiological mechanisms that may be common to depressive and AD pathologies. This review also discusses emerging insights into the role of Tau and its malfunction in disrupting neuronal cascades and neuroplasticity and, thus triggering brain pathology.
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Affiliation(s)
- Ioannis Sotiropoulos
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho - Campus de Gualtar, Braga, Portugal.
- ICVS/3B's - PT Government Associate Laboratory, Braga/Guimarães, Portugal.
| | - Joana M Silva
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho - Campus de Gualtar, Braga, Portugal
- ICVS/3B's - PT Government Associate Laboratory, Braga/Guimarães, Portugal
| | - Patricia Gomes
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho - Campus de Gualtar, Braga, Portugal
- ICVS/3B's - PT Government Associate Laboratory, Braga/Guimarães, Portugal
| | - Nuno Sousa
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho - Campus de Gualtar, Braga, Portugal
- ICVS/3B's - PT Government Associate Laboratory, Braga/Guimarães, Portugal
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16
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Karikari TK, Nagel DA, Grainger A, Clarke-Bland C, Hill EJ, Moffat KG. Preparation of stable tau oligomers for cellular and biochemical studies. Anal Biochem 2018; 566:67-74. [PMID: 30315761 PMCID: PMC6331036 DOI: 10.1016/j.ab.2018.10.013] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Revised: 09/26/2018] [Accepted: 10/08/2018] [Indexed: 02/02/2023]
Abstract
Increasing evidence suggests that small oligomers are the principal neurotoxic species of tau in Alzheimer's disease and other tauopathies. However, mechanisms of tau oligomer-mediated neurodegeneration are poorly understood. The transience of oligomers due to aggregation can compromise the stability of oligomers prepared in vitro. Consequently, we sought to develop an efficient method which maintains the stability and globular conformation of preformed oligomers. This study demonstrates that labeling a single-cysteine form of the pro-aggregant tau four-repeat region (K18) with either Alexa Fluor 488-C5-maleimide or N-ethylmaleimide in reducing conditions stabilizes oligomers by impeding their further aggregation. Furthermore, the use of this approach to study the propagation of labeled extracellular tau K18 oligomers into human neuroblastoma cells and human stem cell-derived neurons is described. This method is potentially applicable for preparing stabilized oligomers of tau for diagnostic and biomarker tests, as well as for in vitro structure-activity relationship assays. The transient nature of tau aggregation makes it difficult to maintain the stability of preformed oligomers. Efficient labeling of tau K18 with Alexa Fluor-488-C5-maleimide or N-ethyl maleimide stabilizes the resulting oligomers. Oligomers applied exogenously are propagated intracellularly by cultured human iPSC neurons and neuroblastoma cells. Oligomer preparation by maleimide labeling allows mechanistic studies of tau aggregation and its link to neurodegeneration.
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Affiliation(s)
- Thomas K Karikari
- School of Life Sciences, University of Warwick, Coventry, CV4 7AL, UK; Midlands Integrative Biosciences Training Partnership, University of Warwick, Coventry, CV4 7AL, UK.
| | - David A Nagel
- School of Life and Health Sciences, Aston University, Birmingham, B4 7ET, UK
| | - Alastair Grainger
- School of Life and Health Sciences, Aston University, Birmingham, B4 7ET, UK
| | | | - Eric J Hill
- School of Life and Health Sciences, Aston University, Birmingham, B4 7ET, UK
| | - Kevin G Moffat
- School of Life Sciences, University of Warwick, Coventry, CV4 7AL, UK
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17
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Vaz-Silva J, Gomes P, Jin Q, Zhu M, Zhuravleva V, Quintremil S, Meira T, Silva J, Dioli C, Soares-Cunha C, Daskalakis NP, Sousa N, Sotiropoulos I, Waites CL. Endolysosomal degradation of Tau and its role in glucocorticoid-driven hippocampal malfunction. EMBO J 2018; 37:embj.201899084. [PMID: 30166454 DOI: 10.15252/embj.201899084] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Revised: 08/03/2018] [Accepted: 08/09/2018] [Indexed: 12/24/2022] Open
Abstract
Emerging studies implicate Tau as an essential mediator of neuronal atrophy and cognitive impairment in Alzheimer's disease (AD), yet the factors that precipitate Tau dysfunction in AD are poorly understood. Chronic environmental stress and elevated glucocorticoids (GC), the major stress hormones, are associated with increased risk of AD and have been shown to trigger intracellular Tau accumulation and downstream Tau-dependent neuronal dysfunction. However, the mechanisms through which stress and GC disrupt Tau clearance and degradation in neurons remain unclear. Here, we demonstrate that Tau undergoes degradation via endolysosomal sorting in a pathway requiring the small GTPase Rab35 and the endosomal sorting complex required for transport (ESCRT) machinery. Furthermore, we find that GC impair Tau degradation by decreasing Rab35 levels, and that AAV-mediated expression of Rab35 in the hippocampus rescues GC-induced Tau accumulation and related neurostructural deficits. These studies indicate that the Rab35/ESCRT pathway is essential for Tau clearance and part of the mechanism through which GC precipitate brain pathology.
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Affiliation(s)
- João Vaz-Silva
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal.,ICVS/3B's - PT Government Associate Laboratory, Braga, Portugal.,Department of Pathology and Cell Biology, Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University Medical Center, New York, NY, USA
| | - Patrícia Gomes
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal.,ICVS/3B's - PT Government Associate Laboratory, Braga, Portugal
| | - Qi Jin
- Department of Pathology and Cell Biology, Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University Medical Center, New York, NY, USA
| | - Mei Zhu
- Department of Pathology and Cell Biology, Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University Medical Center, New York, NY, USA
| | - Viktoriya Zhuravleva
- Department of Pathology and Cell Biology, Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University Medical Center, New York, NY, USA.,Neurobiology and Behavior Graduate Program, Columbia University, New York, NY, USA
| | - Sebastian Quintremil
- Department of Pathology and Cell Biology, Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University Medical Center, New York, NY, USA
| | - Torcato Meira
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal.,ICVS/3B's - PT Government Associate Laboratory, Braga, Portugal.,Department of Neuroscience, Columbia University, New York, NY, USA
| | - Joana Silva
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal.,ICVS/3B's - PT Government Associate Laboratory, Braga, Portugal
| | - Chrysoula Dioli
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal.,ICVS/3B's - PT Government Associate Laboratory, Braga, Portugal
| | - Carina Soares-Cunha
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal.,ICVS/3B's - PT Government Associate Laboratory, Braga, Portugal
| | | | - Nuno Sousa
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal.,ICVS/3B's - PT Government Associate Laboratory, Braga, Portugal
| | - Ioannis Sotiropoulos
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal.,ICVS/3B's - PT Government Associate Laboratory, Braga, Portugal
| | - Clarissa L Waites
- Department of Pathology and Cell Biology, Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University Medical Center, New York, NY, USA .,Department of Neuroscience, Columbia University, New York, NY, USA
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18
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Jebarupa B, Muralidharan M, Srinivasu BY, Mandal AK, Mitra G. Effect of altered solution conditions on tau conformational dynamics: Plausible implication on order propensity and aggregation. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2018; 1866:668-679. [DOI: 10.1016/j.bbapap.2018.04.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Revised: 04/03/2018] [Accepted: 04/05/2018] [Indexed: 01/23/2023]
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19
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Florenzano F, Veronica C, Ciasca G, Ciotti MT, Pittaluga A, Olivero G, Feligioni M, Iannuzzi F, Latina V, Maria Sciacca MF, Sinopoli A, Milardi D, Pappalardo G, Marco DS, Papi M, Atlante A, Bobba A, Borreca A, Calissano P, Amadoro G. Extracellular truncated tau causes early presynaptic dysfunction associated with Alzheimer's disease and other tauopathies. Oncotarget 2017; 8:64745-64778. [PMID: 29029390 PMCID: PMC5630290 DOI: 10.18632/oncotarget.17371] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2017] [Accepted: 04/11/2017] [Indexed: 12/14/2022] Open
Abstract
The largest part of tau secreted from AD nerve terminals and released in cerebral spinal fluid (CSF) is C-terminally truncated, soluble and unaggregated supporting potential extracellular role(s) of NH2 -derived fragments of protein on synaptic dysfunction underlying neurodegenerative tauopathies, including Alzheimer's disease (AD). Here we show that sub-toxic doses of extracellular-applied human NH2 tau 26-44 (aka NH 2 htau) -which is the minimal active moiety of neurotoxic 20-22kDa peptide accumulating in vivo at AD synapses and secreted into parenchyma- acutely provokes presynaptic deficit in K+ -evoked glutamate release on hippocampal synaptosomes along with alteration in local Ca2+ dynamics. Neuritic dystrophy, microtubules breakdown, deregulation in presynaptic proteins and loss of mitochondria located at nerve endings are detected in hippocampal cultures only after prolonged exposure to NH 2 htau. The specificity of these biological effects is supported by the lack of any significant change, either on neuronal activity or on cellular integrity, shown by administration of its reverse sequence counterpart which behaves as an inactive control, likely due to a poor conformational flexibility which makes it unable to dynamically perturb biomembrane-like environments. Our results demonstrate that one of the AD-relevant, soluble and secreted N-terminally truncated tau forms can early contribute to pathology outside of neurons causing alterations in synaptic activity at presynaptic level, independently of overt neurodegeneration.
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Affiliation(s)
| | | | - Gabriele Ciasca
- Institute of Physics, Catholic University of the Sacred Heart, Largo F Vito 1, Rome, Italy
| | - Maria Teresa Ciotti
- Institute of Cellular Biology and Neuroscience, CNR, IRCSS Santa Lucia Foundation, Rome, Italy
| | - Anna Pittaluga
- Department of Pharmacy, Pharmacology and Toxicology Section, University of Genoa, Genoa, Viale Cembrano, Italy
| | - Gunedalina Olivero
- Department of Pharmacy, Pharmacology and Toxicology Section, University of Genoa, Genoa, Viale Cembrano, Italy
| | - Marco Feligioni
- European Brain Research Institute, Rome, Italy
- Department of Neurorehabilitation Sciences, Casa Cura Policlinico, Milan, Italy
| | | | | | | | | | - Danilo Milardi
- Institute of Biostructures and Bioimaging, CNR, Catania, Italy
| | | | - De Spirito Marco
- Institute of Physics, Catholic University of the Sacred Heart, Largo F Vito 1, Rome, Italy
| | - Massimiliano Papi
- Institute of Physics, Catholic University of the Sacred Heart, Largo F Vito 1, Rome, Italy
| | - Anna Atlante
- Institute of Biomembranes and Bioenergetics, CNR, Bari, Italy
- Center of Excellence for Biomedical Research, University of Genoa, Genoa, Viale Benedetto XV, Italy
| | - Antonella Bobba
- Institute of Biomembranes and Bioenergetics, CNR, Bari, Italy
- Center of Excellence for Biomedical Research, University of Genoa, Genoa, Viale Benedetto XV, Italy
| | - Antonella Borreca
- Institute of Cellular Biology and Neuroscience, CNR, IRCSS Santa Lucia Foundation, Rome, Italy
| | | | - Giuseppina Amadoro
- European Brain Research Institute, Rome, Italy
- Institute of Translational Pharmacology, CNR, Rome, Italy
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20
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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: 565] [Impact Index Per Article: 80.7] [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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21
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Chiarini A, Armato U, Gardenal E, Gui L, Dal Prà I. Amyloid β-Exposed Human Astrocytes Overproduce Phospho-Tau and Overrelease It within Exosomes, Effects Suppressed by Calcilytic NPS 2143-Further Implications for Alzheimer's Therapy. Front Neurosci 2017; 11:217. [PMID: 28473749 PMCID: PMC5397492 DOI: 10.3389/fnins.2017.00217] [Citation(s) in RCA: 76] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2016] [Accepted: 03/31/2017] [Indexed: 11/13/2022] Open
Abstract
The two main drivers of Alzheimer's disease (AD), amyloid-β (Aβ) and hyperphosphorylated Tau (p-Tau) oligomers, cooperatively accelerate AD progression, but a hot debate is still ongoing about which of the two appears first. Here we present preliminary evidence showing that Tau and p-Tau are expressed by untransformed cortical adult human astrocytes in culture and that exposure of such cells to an Aβ42 proxy, Aβ25−35, which binds the calcium-sensing receptor (CaSR) and activates its signaling, significantly increases intracellular p-Tau levels, an effect CaSR antagonist (calcilytic) NPS 2143 wholly hinders. The astrocytes also release both Tau and p-Tau by means of exosomes into the extracellular medium, an activity that could mediate p-Tau diffusion within the brain. Preliminary data also indicate that exosomal levels of p-Tau increase after Aβ25−35 exposure, but remain unchanged in cells pre-treated for 30-min with NPS 2143 before adding Aβ25−35. Thus, our previous and present findings raise the unifying prospect that Aβ•CaSR signaling plays a crucial role in AD development and progression by simultaneously activating (i) the amyloidogenic processing of amyloid precursor holoprotein, whose upshot is a surplus production and secretion of Aβ42 oligomers, and (ii) the GSK-3β-mediated increased production of p-Tau oligomers which are next released extracellularly inside exosomes. Therefore, as calcilytics suppress both effects on Aβ42 and p-Tau metabolic handling, these highly selective antagonists of pathological Aβ•CaSR signaling would effectively halt AD's progressive spread preserving patients' cognition and life quality.
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Affiliation(s)
- Anna Chiarini
- Human Histology and Embryology Unit, Medical School, University of VeronaVerona, Venetia, Italy
| | - Ubaldo Armato
- Human Histology and Embryology Unit, Medical School, University of VeronaVerona, Venetia, Italy
| | - Emanuela Gardenal
- Human Histology and Embryology Unit, Medical School, University of VeronaVerona, Venetia, Italy
| | - Li Gui
- Department of Neurology, Southwest Hospital, Third Military Medical UniversityChongqing, China
| | - Ilaria Dal Prà
- Human Histology and Embryology Unit, Medical School, University of VeronaVerona, Venetia, Italy
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22
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Shafiei SS, Guerrero-Muñoz MJ, Castillo-Carranza DL. Tau Oligomers: Cytotoxicity, Propagation, and Mitochondrial Damage. Front Aging Neurosci 2017; 9:83. [PMID: 28420982 PMCID: PMC5378766 DOI: 10.3389/fnagi.2017.00083] [Citation(s) in RCA: 200] [Impact Index Per Article: 28.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Accepted: 03/16/2017] [Indexed: 11/13/2022] Open
Abstract
Aging has long been considered as the main risk factor for several neurodegenerative disorders including a large group of diseases known as tauopathies. Even though neurofibrillary tangles (NFTs) have been examined as the main histopathological hallmark, they do not seem to play a role as the toxic entities leading to disease. Recent studies suggest that an intermediate form of tau, prior to NFT formation, the tau oligomer, is the true toxic species. However, the mechanisms by which tau oligomers trigger neurodegeneration remain unknown. This review summarizes recent findings regarding the role of tau oligomers in disease, including release from cells, propagation from affected to unaffected brain regions, uptake into cells, and toxicity via mitochondrial dysfunction. A greater understanding of tauopathies may lead to future advancements in regards to prevention and treatment.
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Affiliation(s)
- Scott S Shafiei
- Department of Neurology, Neuroscience and Cell Biology, University of Texas Medical BranchGalveston, TX, USA
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23
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Maphis NM, Jiang S, Binder J, Wright C, Gopalan B, Lamb BT, Bhaskar K. Whole Genome Expression Analysis in a Mouse Model of Tauopathy Identifies MECP2 as a Possible Regulator of Tau Pathology. Front Mol Neurosci 2017; 10:69. [PMID: 28367114 PMCID: PMC5355442 DOI: 10.3389/fnmol.2017.00069] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Accepted: 02/28/2017] [Indexed: 11/14/2022] Open
Abstract
Increasing evidence suggests that hyperphosphorylation and aggregation of microtubule-associated protein tau (MAPT or tau) correlates with the development of cognitive impairment in Alzheimer’s disease (AD) and related tauopathies. While numerous attempts have been made to model AD-relevant tau pathology in various animal models, there has been very limited success for these models to fully recapitulate the progression of disease as seen in human tauopathies. Here, we performed whole genome gene expression in a genomic mouse model of tauopathy that expressed human MAPT gene under the control of endogenous human MAPT promoter and also were complete knockout for endogenous mouse tau [referred to as ‘hTauMaptKO(Duke)′ mice]. First, whole genome expression analysis revealed 64 genes, which were differentially expressed (32 up-regulated and 32 down-regulated) in the hippocampus of 6-month-old hTauMaptKO(Duke) mice compared to age-matched non-transgenic controls. Genes relevant to neuronal function or neurological disease include up-regulated genes: PKC-alpha (Prkca), MECP2 (Mecp2), STRN4 (Strn4), SLC40a1 (Slc40a1), POLD2 (Pold2), PCSK2 (Pcsk2), and down-regulated genes: KRT12 (Krt12), LASS1 (Cers1), PLAT (Plat), and NRXN1 (Nrxn1). Second, network analysis suggested anatomical structure development, cellular metabolic process, cell death, signal transduction, and stress response were significantly altered biological processes in the hTauMaptKO(Duke) mice as compared to age-matched non-transgenic controls. Further characterization of a sub-group of significantly altered genes revealed elevated phosphorylation of MECP2 (methyl-CpG-binding protein-2), which binds to methylated CpGs and associates with chromatin, in hTauMaptKO(Duke) mice compared to age-matched controls. Third, phoshpho-MECP2 was elevated in autopsy brain samples from human AD compared to healthy controls. Finally, siRNA-mediated knockdown of MECP2 in human tau expressing N2a cells resulted in a significant decrease in total and phosphorylated tau. Together, these results suggest that MECP2 is a potential novel regulator of tau pathology relevant to AD and tauopathies.
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Affiliation(s)
- Nicole M Maphis
- Department of Molecular Genetics and Microbiology, University of New Mexico, Albuquerque NM, USA
| | - Shanya Jiang
- Department of Molecular Genetics and Microbiology, University of New Mexico, Albuquerque NM, USA
| | - Jessica Binder
- Department of Molecular Genetics and Microbiology, University of New Mexico, Albuquerque NM, USA
| | - Carrie Wright
- Lieber Institute for Brain Development, Baltimore MD, USA
| | - Banu Gopalan
- Department of Biostatistics, Cleveland Clinic Foundation Cleveland OH, USA
| | - Bruce T Lamb
- Stark Neurosciences Research Institute, Indiana University, Indianapolis IN, USA
| | - Kiran Bhaskar
- Department of Molecular Genetics and Microbiology, University of New Mexico, Albuquerque NM, USA
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24
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Qi ZP, Wang GX, Xia P, Hou TT, Zhou HL, Wang TJ, Yang XY. Effects of microtubule-associated protein tau expression on neural stem cell migration after spinal cord injury. Neural Regen Res 2016; 11:332-7. [PMID: 27073389 PMCID: PMC4811000 DOI: 10.4103/1673-5374.177744] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Our preliminary proteomics analysis suggested that expression of microtubule-associated protein tau is elevated in the spinal cord after injury. Therefore, the first aim of the present study was to examine tau expression in the injured spinal cord. The second aim was to determine whether tau can regulate neural stem cell migration, a critical factor in the successful treatment of spinal cord injury. We established rat models of spinal cord injury and injected them with mouse hippocampal neural stem cells through the tail vein. We used immunohistochemistry to show that the expression of tau protein and the number of migrated neural stem cells were markedly increased in the injured spinal cord. Furthermore, using a Transwell assay, we showed that neural stem cell migration was not affected by an elevated tau concentration in the outer chamber, but it was decreased by changes in intracellular tau phosphorylation state. These results demonstrate that neural stem cells have targeted migration capability at the site of injury, and that although tau is not a chemokine for targeted migration of neural stem cells, intracellular tau phosphorylation/dephosphorylation can inhibit cell migration.
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Affiliation(s)
- Zhi-Ping Qi
- Department of Orthopedics, the Second Hospital of Jilin University, Changchun, Jilin Province, China
| | - Guo-Xiang Wang
- Department of Orthopedics, the Second Hospital of Jilin University, Changchun, Jilin Province, China
| | - Peng Xia
- Department of Orthopedics, the Second Hospital of Jilin University, Changchun, Jilin Province, China
| | - Ting-Ting Hou
- Department of Orthopedics, the Second Hospital of Jilin University, Changchun, Jilin Province, China
| | - Hong-Li Zhou
- Department of Orthopedics, China-Japan Union Hospital of Jilin University, Changchun, Jilin Province, China
| | - Tie-Jun Wang
- Department of Orthopedics, the Second Hospital of Jilin University, Changchun, Jilin Province, China
| | - Xiao-Yu Yang
- Department of Orthopedics, the Second Hospital of Jilin University, Changchun, Jilin Province, China
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Eftekharzadeh B, Hyman BT, Wegmann S. Structural studies on the mechanism of protein aggregation in age related neurodegenerative diseases. Mech Ageing Dev 2016; 156:1-13. [PMID: 27005270 DOI: 10.1016/j.mad.2016.03.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Revised: 02/12/2016] [Accepted: 03/03/2016] [Indexed: 01/09/2023]
Abstract
The progression of many neurodegenerative diseases is assumed to be caused by misfolding of specific characteristic diseases related proteins, resulting in aggregation and fibril formation of these proteins. Protein misfolding associated age related diseases, although different in disease manifestations, share striking similarities. In all cases, one disease protein aggregates and loses its function or additionally shows a toxic gain of function. However, the clear link between these individual amyloid-like protein aggregates and cellular toxicity is often still uncertain. The similar features of protein misfolding and aggregation in this group of proteins, all involved in age related neurodegenerative diseases, results in high interest in characterization of their structural properties. We review here recent findings on structural properties of some age related disease proteins, in the context of their biological importance in disease.
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Affiliation(s)
- Bahareh Eftekharzadeh
- Department of Neurology, Massachusetts General Hospital and Mass General Institute for Neurodegenerative Disease, Charlestown, MA 02129, USA.
| | - Bradley T Hyman
- Department of Neurology, Massachusetts General Hospital and Mass General Institute for Neurodegenerative Disease, Charlestown, MA 02129, USA
| | - Susanne Wegmann
- Department of Neurology, Massachusetts General Hospital and Mass General Institute for Neurodegenerative Disease, Charlestown, MA 02129, USA
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26
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Liu C, Song X, Nisbet R, Götz J. Co-immunoprecipitation with Tau Isoform-specific Antibodies Reveals Distinct Protein Interactions and Highlights a Putative Role for 2N Tau in Disease. J Biol Chem 2016; 291:8173-88. [PMID: 26861879 PMCID: PMC4825019 DOI: 10.1074/jbc.m115.641902] [Citation(s) in RCA: 97] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2015] [Indexed: 01/24/2023] Open
Abstract
Alternative splicing generates multiple isoforms of the microtubule-associated protein Tau, but little is known about their specific function. In the adult mouse brain, three Tau isoforms are expressed that contain either 0, 1, or 2 N-terminal inserts (0N, 1N, and 2N). We generated Tau isoform-specific antibodies and performed co-immunoprecipitations followed by tandem mass tag multiplexed quantitative mass spectrometry. We identified novel Tau-interacting proteins of which one-half comprised membrane-bound proteins, localized to the plasma membrane, mitochondria, and other organelles. Tau was also found to interact with proteins involved in presynaptic signal transduction. MetaCore analysis revealed one major Tau interaction cluster that contained 33 Tau pulldown proteins. To explore the pathways in which these proteins are involved, we conducted an ingenuity pathway analysis that revealed two significant overlapping pathways, “cell-to-cell signaling and interaction” and “neurological disease.” The functional enrichment tool DAVID showed that in particular the 2N Tau-interacting proteins were specifically associated with neurological disease. Finally, for a subset of Tau interactions (apolipoprotein A1 (apoA1), apoE, mitochondrial creatine kinase U-type, β-synuclein, synaptogyrin-3, synaptophysin, syntaxin 1B, synaptotagmin, and synapsin 1), we performed reverse co-immunoprecipitations, confirming the preferential interaction of specific isoforms. For example, apoA1 displayed a 5-fold preference for the interaction with 2N, whereas β-synuclein showed preference for 0N. Remarkably, a reverse immunoprecipitation with apoA1 detected only the 2N isoform. This highlights distinct protein interactions of the different Tau isoforms, suggesting that they execute different functions in brain tissue.
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Affiliation(s)
- Chang Liu
- From the Sydney Medical School, Brain and Mind Research Institute, University of Sydney, Camperdown, New South Wales 2050
| | - Xiaomin Song
- the Australian Proteome Analysis Facility, Macquarie University (Sydney), New South Wales 2109, and
| | - Rebecca Nisbet
- the Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, University of Queensland, St. Lucia Campus (Brisbane), Queensland 4072, Australia
| | - Jürgen Götz
- the Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, University of Queensland, St. Lucia Campus (Brisbane), Queensland 4072, Australia
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Bukar Maina M, Al-Hilaly YK, Serpell LC. Nuclear Tau and Its Potential Role in Alzheimer's Disease. Biomolecules 2016; 6:9. [PMID: 26751496 PMCID: PMC4808803 DOI: 10.3390/biom6010009] [Citation(s) in RCA: 100] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Revised: 12/16/2015] [Accepted: 12/23/2015] [Indexed: 12/14/2022] Open
Abstract
Tau protein, found in both neuronal and non-neuronal cells, forms aggregates in neurons that constitutes one of the hallmarks of Alzheimer’s disease (AD). For nearly four decades, research efforts have focused more on tau’s role in physiology and pathology in the context of the microtubules, even though, for over three decades, tau has been localised in the nucleus and the nucleolus. Its nuclear and nucleolar localisation had stimulated many questions regarding its role in these compartments. Data from cell culture, mouse brain, and the human brain suggests that nuclear tau could be essential for genome defense against cellular distress. However, its nature of translocation to the nucleus, its nuclear conformation and interaction with the DNA and other nuclear proteins highly suggest it could play multiple roles in the nucleus. To find efficient tau-based therapies, there is a need to understand more about the functional relevance of the varied cellular distribution of tau, identify whether specific tau transcripts or isoforms could predict tau’s localisation and function and how they are altered in diseases like AD. Here, we explore the cellular distribution of tau, its nuclear localisation and function and its possible involvement in neurodegeneration.
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Affiliation(s)
- Mahmoud Bukar Maina
- School of Life Sciences, University of Sussex, Falmer, Brighton BN1 9QG, East Sussex, UK.
- Department of Human Anatomy, College of Medical Science, Gombe State University, Gombe 760, Nigeria.
| | - Youssra K Al-Hilaly
- School of Life Sciences, University of Sussex, Falmer, Brighton BN1 9QG, East Sussex, UK.
- Chemistry Department, College of Sciences, Al-Mustansiriyah University, Baghdad, Iraq.
| | - Louise C Serpell
- School of Life Sciences, University of Sussex, Falmer, Brighton BN1 9QG, East Sussex, UK.
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Medina M, Avila J. Further understanding of tau phosphorylation: implications for therapy. Expert Rev Neurother 2015; 15:115-22. [PMID: 25555397 DOI: 10.1586/14737175.2015.1000864] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Tau is a brain microtubule-associated protein that regulates microtubule structure and function. Prominent tau neurofibrillary pathology is a common feature in a number of neurodegenerative disorders collectively referred to as tauopathies, the most common of which is Alzheimer's disease. Beyond its classical role as a microtubule-associated protein, recent advances in our understanding of tau cellular functions have unveiled novel important tau cellular functions that may also play a pivotal role in pathogenesis and render novel targets for therapeutic intervention. Regulation of tau behavior and function under physiological and pathological conditions is mainly achieved through post-translational modifications, especially phosphorylation, which has significant implications for the development of novel therapeutic approaches in a number of neurodegenerative disorders.
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Affiliation(s)
- Miguel Medina
- Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED), Valderrebollo 5, 28041-Madrid, Spain
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Abstract
Epidemiologic and experimental data suggest the involvement of cholesterol metabolism in the development and progression of Alzheimer disease and Niemann-Pick type C disease, but not of frontotemporal dementias. In these 3 neurodegenerative diseases, however, protein tau hyperphosphorylation and aggregation into neurofibrillary tangles are observed. To elucidate the relationship between cholesterol and tau, we compared sterol levels of neurons burdened with neurofibrillary tangles with those of their unaffected neighbors using semiquantitative filipin fluorescence microscopy in mice expressing P301L mutant human tau (a well-described model of FTDP-17) and in P301L transgenic mice lacking apolipoprotein E (the major cholesterol transporter in the brain). Cellular unesterified cholesterol was higher in neurons affected by tau pathology irrespective of apolipoprotein E deficiency. This argues for an impact of tau pathology on cellular cholesterol homeostasis. We suggest that there is a bidirectional mode of action: Disturbances in cellular cholesterol metabolism may promote tau pathology, but tau pathology may also alter neuronal cholesterol homeostasis; once it is established, a vicious cycle may promote neurofibrillary tangle formation.
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LAGUNES TERESA, HERRERA-RIVERO MARISOL, HERNÁNDEZ-AGUILAR MARÍAELENA, ARANDA-ABREU GONZALOE. Abeta(1-42) induces abnormal alternative splicing of tau exons 2/3 in NGF-induced PC12 cells. AN ACAD BRAS CIENC 2014; 86:1927-34. [DOI: 10.1590/0001-3765201420130333] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2013] [Accepted: 08/06/2014] [Indexed: 12/19/2022] Open
Abstract
Protein tau plays a pivotal role in the pathophysiology of Alzheimer's disease, where its hyperphos-phorylation promotes aggregation and microtubule destabilization. Tau undergoes alternative splicing which generates six isoforms in the human brain, due to inclusion/exclusion of exons 2, 3 and 10. Dysregulation of the splicing process of tau exon 10 is sufficient to cause tauopathy and has shown to be influenced by beta-amyloid peptides, but splicing of other exons is less studied. We studied the effects of beta-amyloid(42) in the alternative splicing of tau exons 2/3 and 6, using untreated and Nerve Growth Factor-induced PC12 cells. Beta-amyloid exposure caused formed cell processes to retract in differentiated cells and altered the expression of exons 2/3 in both undifferentiated and differentiated cells. Expression of exon 6 was repressed in undifferentiated cells only. Our results suggest that beta-amyloid interferes with the splicing process of exons 2/3, favoring their exclusion and thus the expression of immature tau isoforms that are less efficient in stabilizing microtubules and may also be more prone to hyperphosphorylation. The molecular mechanism for this amyloid-tau interaction remains to be determined, but may have potential implications for the understanding of the underlying neuropathological processes in Alzheimer's disease.
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31
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Frequent and symmetric deposition of misfolded tau oligomers within presynaptic and postsynaptic terminals in Alzheimer's disease. Acta Neuropathol Commun 2014; 2:146. [PMID: 25330988 PMCID: PMC4209049 DOI: 10.1186/s40478-014-0146-2] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Accepted: 07/25/2014] [Indexed: 11/10/2022] Open
Abstract
The accumulation of neurofibrillary tangles in Alzheimer’s disease (AD) propagates with characteristic spatiotemporal patterns which follow brain network connections, implying trans-synaptic transmission of tauopathy. Since misfolded tau has been shown to transmit across synapses in AD animal models, we hypothesized that synapses in AD patients may contain misfolded tau. By immunofluorescence imaging of bipartite synapses from AD subjects, we detected tau protein in 38.4% of presynaptic and 50.9% of postsynaptic terminals. The pre/post distribution for hyperphosphorylated tau was 26.9%/30.7%, and for misfolded tau 18.3%/19.3%. In the temporal cortex, microscopic aggregates of tau, containing ultra-stable oligomers, were estimated to accumulate within trillions of synapses, outnumbering macroscopic tau aggregates such as tangles by 10000 fold. Non-demented elderly also showed considerable synaptic tau hyperphosphorylation and some misfolding, implicating the synapse as one of the first subcellular compartments affected by tauopathy. Misfolding of tau protein appeared to occur in situ inside synaptic terminals, without mislocalizing or mistrafficking. Misfolded tau at synapses may represent early signs of neuronal degeneration, mediators of synaptotoxicity, and anatomical substrates for transmitting tauopathy, but its actual role in these processes remain to be elucidated.
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Collin L, Bohrmann B, Göpfert U, Oroszlan-Szovik K, Ozmen L, Grüninger F. Neuronal uptake of tau/pS422 antibody and reduced progression of tau pathology in a mouse model of Alzheimer‘s disease. Brain 2014; 137:2834-46. [DOI: 10.1093/brain/awu213] [Citation(s) in RCA: 142] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
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The formation of tau pore-like structures is prevalent and cell specific: possible implications for the disease phenotypes. Acta Neuropathol Commun 2014; 2:56. [PMID: 24887264 PMCID: PMC4231072 DOI: 10.1186/2051-5960-2-56] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2014] [Accepted: 05/13/2014] [Indexed: 12/01/2022] Open
Abstract
Pathological aggregation of the microtubule-associated protein tau and subsequent accumulation of neurofibrillary tangles (NFTs) or other tau-containing inclusions are defining histopathological features of many neurodegenerative diseases, which are collectively known as tauopathies. Due to conflicting results regarding a correlation between the presence of NFTs and disease progression, the mechanism linking pathological tau aggregation with cell death is poorly understood. An emerging view is that NFTs are not the toxic entity in tauopathies; rather, tau intermediates between monomers and NFTs are pathogenic. Several proteins associated with neurodegenerative diseases, such as β-amyloid (Aβ) and α-synuclein, have the tendency to form pore-like amyloid structures (annular protofibrils, APFs) that mimic the membrane-disrupting properties of pore-forming protein toxins. The present study examined the similarities of tau APFs with other tau amyloid species and showed for the first time the presence of tau APFs in brain tissue from patients with progressive supranuclear palsy (PSP) and dementia with Lewy bodies (DLB), as well as in the P301L mouse model, which overexpresses mutated tau. Furthermore, we found that APFs are preceded by tau oligomers and do not go on to form NFTs, evading fibrillar fate. Collectively, our results demonstrate that in vivo APF formation depends on mutations in tau, phosphorylation levels, and cell type. These findings establish the pathological significance of tau APFs in vivo and highlight their suitability as therapeutic targets for several neurodegenerative tauopathies.
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Maurin H, Lechat B, Borghgraef P, Devijver H, Jaworski T, Van Leuven F. Terminal hypothermic Tau.P301L mice have increased Tau phosphorylation independently of glycogen synthase kinase 3α/β. Eur J Neurosci 2014; 40:2442-53. [DOI: 10.1111/ejn.12595] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2014] [Revised: 03/20/2014] [Accepted: 03/23/2014] [Indexed: 01/28/2023]
Affiliation(s)
- Hervé Maurin
- Experimental Genetics Group LEGTEGG; Department of Human Genetics; KU Leuven; Campus Gasthuisberg ON1 06.602 Herestraat 49 B-3000 Leuven Belgium
| | - Benoit Lechat
- Experimental Genetics Group LEGTEGG; Department of Human Genetics; KU Leuven; Campus Gasthuisberg ON1 06.602 Herestraat 49 B-3000 Leuven Belgium
| | - Peter Borghgraef
- Experimental Genetics Group LEGTEGG; Department of Human Genetics; KU Leuven; Campus Gasthuisberg ON1 06.602 Herestraat 49 B-3000 Leuven Belgium
| | - Herman Devijver
- Experimental Genetics Group LEGTEGG; Department of Human Genetics; KU Leuven; Campus Gasthuisberg ON1 06.602 Herestraat 49 B-3000 Leuven Belgium
| | | | - Fred Van Leuven
- Experimental Genetics Group LEGTEGG; Department of Human Genetics; KU Leuven; Campus Gasthuisberg ON1 06.602 Herestraat 49 B-3000 Leuven Belgium
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Pooler AM, Noble W, Hanger DP. A role for tau at the synapse in Alzheimer's disease pathogenesis. Neuropharmacology 2014; 76 Pt A:1-8. [PMID: 24076336 DOI: 10.1016/j.neuropharm.2013.09.018] [Citation(s) in RCA: 129] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2013] [Revised: 09/06/2013] [Accepted: 09/07/2013] [Indexed: 01/05/2023]
Abstract
Alzheimer's disease (AD) is characterized by brain deposition of amyloid plaques and tau neurofibrillary tangles along with steady cognitive decline. Although the mechanism by which AD pathogenesis occurs is unclear, accumulating evidence suggests that dysfunction and loss of synaptic connections may be an early event underlying disease progression. Profound synapse degeneration is observed in AD, and the density of these connections strongly correlates with cognitive ability. Initial investigations into AD-related synaptic changes focused on the toxic effects of amyloid. However, recent research suggests an emerging role for tau at the synapse. Even in the absence of tangles, mice overexpressing human tau display significant synaptic degeneration, suggesting that soluble, oligomeric tau is the synaptotoxic species. However, the localization of tau within synapses in both healthy and AD brains indicates that tau might play a role in normal synaptic function, which may be disrupted in disease. Tau is able to impact synaptic activity in several ways: studies show tau interacting directly with post-synaptic signaling complexes, regulating glutamatergic receptor content in dendritic spines, and influencing targeting and function of synaptic mitochondria. Early trials of tau-targeted immunotherapy reduce tau pathology and synapse loss, indicating that the toxic effects of tau may be reversible within a certain time frame. Understanding the role of tau in both normal and degenerating synapses is crucial for the development of therapeutic strategies designed to ameliorate synapse loss and prevent AD pathogenesis. This article is part of the Special Issue entitled 'The Synaptic Basis of Neurodegenerative Disorders'.
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Affiliation(s)
- Amy M Pooler
- King's College London, Institute of Psychiatry, Department of Neuroscience (PO37), De Crespigny Park, London SE5 8AF, United Kingdom
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Propagation of tau pathology in Alzheimer's disease: identification of novel therapeutic targets. ALZHEIMERS RESEARCH & THERAPY 2013; 5:49. [PMID: 24152385 PMCID: PMC3978816 DOI: 10.1186/alzrt214] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Accumulation and aggregation of the microtubule-associated protein tau are a pathological hallmark of neurodegenerative disorders such as Alzheimer’s disease (AD). In AD, tau becomes abnormally phosphorylated and forms inclusions throughout the brain, starting in the entorhinal cortex and progressively affecting additional brain regions as the disease progresses. Formation of these inclusions is thought to lead to synapse loss and cell death. Tau is also found in the cerebrospinal fluid (CSF), and elevated levels are a biomarker for AD. Until recently, it was thought that the presence of tau in the CSF was due to the passive release of aggregated tau from dead or dying tangle-bearing neurons. However, accumulating evidence from different AD model systems suggests that tau is actively secreted and transferred between synaptically connected neurons. Transgenic mouse lines with localized expression of aggregating human tau in the entorhinal cortex have demonstrated that, as these animals age, tau becomes mislocalized from axons to cell bodies and dendrites and that human tau-positive aggregates form first in the entorhinal cortex and later in downstream projection targets. Numerous in vitro and in vivo studies have provided insight into the mechanisms by which tau may be released and internalized by neurons and have started to provide insight into how tau pathology may spread in AD. In this review, we discuss the evidence for regulated tau release and its specific uptake by neurons. Furthermore, we identify possible therapeutic targets for preventing the propagation of tau pathology, as inhibition of tau transfer may restrict development of tau tangles in a small subset of neurons affected in early stages of AD and therefore prevent widespread neuron loss and cognitive dysfunction associated with later stages of the disease.
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Sontag JM, Nunbhakdi-Craig V, Sontag E. Leucine carboxyl methyltransferase 1 (LCMT1)-dependent methylation regulates the association of protein phosphatase 2A and Tau protein with plasma membrane microdomains in neuroblastoma cells. J Biol Chem 2013; 288:27396-27405. [PMID: 23943618 DOI: 10.1074/jbc.m113.490102] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Down-regulation of protein phosphatase 2A (PP2A) methylation occurs in Alzheimer disease (AD). However, the regulation of PP2A methylation remains poorly understood. We have reported that altered leucine carboxyl methyltransferase (LCMT1)-dependent PP2A methylation is associated with down-regulation of PP2A holoenzymes containing the Bα subunit (PP2A/Bα) and subsequent accumulation of phosphorylated Tau in N2a cells, in vivo and in AD. Here, we show that pools of LCMT1, methylated PP2A, and PP2A/Bα are co-enriched in cholesterol-rich plasma membrane microdomains/rafts purified from N2a cells. In contrast, demethylated PP2A is preferentially distributed in non-rafts wherein small amounts of the PP2A methylesterase PME-1 are exclusively present. A methylation-incompetent PP2A mutant is excluded from rafts. Enhanced methylation of PP2A promotes the association of PP2A and Tau with the plasma membrane. Altered PP2A methylation following expression of a catalytically inactive LCMT1 mutant, knockdown of LCMT1, or alterations in one-carbon metabolism all result in a loss of plasma membrane-associated PP2A and Tau in N2a cells. This correlates with accumulation of soluble phosphorylated Tau, a hallmark of AD and other tauopathies. Thus, our findings reveal a distinct compartmentalization of PP2A and PP2A regulatory enzymes in plasma membrane microdomains and identify a novel methylation-dependent mechanism involved in modulating the targeting of PP2A, and its substrate Tau, to the plasma membrane. We propose that alterations in the membrane localization of PP2A and Tau following down-regulation of LCMT1 may lead to PP2A and Tau dysfunction in AD.
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Affiliation(s)
- Jean-Marie Sontag
- School of Biomedical Sciences and Pharmacy, Faculty of Health and Medicine, University of Newcastle, Callaghan, New South Wales 2308, Australia
| | | | - Estelle Sontag
- School of Biomedical Sciences and Pharmacy, Faculty of Health and Medicine, University of Newcastle, Callaghan, New South Wales 2308, Australia.
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Noble W, Hanger DP, Miller CCJ, Lovestone S. The importance of tau phosphorylation for neurodegenerative diseases. Front Neurol 2013; 4:83. [PMID: 23847585 PMCID: PMC3696910 DOI: 10.3389/fneur.2013.00083] [Citation(s) in RCA: 263] [Impact Index Per Article: 23.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2013] [Accepted: 06/14/2013] [Indexed: 01/20/2023] Open
Abstract
Fibrillar deposits of highly phosphorylated tau are a key pathological feature of several neurodegenerative tauopathies including Alzheimer's disease (AD) and some frontotemporal dementias. Increasing evidence suggests that the presence of these end-stage neurofibrillary lesions do not cause neuronal loss, but rather that alterations to soluble tau proteins induce neurodegeneration. In particular, aberrant tau phosphorylation is acknowledged to be a key disease process, influencing tau structure, distribution, and function in neurons. Although typically described as a cytosolic protein that associates with microtubules and regulates axonal transport, several additional functions of tau have recently been demonstrated, including roles in DNA stabilization, and synaptic function. Most recently, studies examining the trans-synaptic spread of tau pathology in disease models have suggested a potential role for extracellular tau in cell signaling pathways intrinsic to neurodegeneration. Here we review the evidence showing that tau phosphorylation plays a key role in neurodegenerative tauopathies. We also comment on the tractability of altering phosphorylation-dependent tau functions for therapeutic intervention in AD and related disorders.
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Affiliation(s)
- Wendy Noble
- Department of Neuroscience, King's College London, Institute of Psychiatry , London , UK
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Rodríguez-Martín T, Cuchillo-Ibáñez I, Noble W, Nyenya F, Anderton BH, Hanger DP. Tau phosphorylation affects its axonal transport and degradation. Neurobiol Aging 2013; 34:2146-57. [PMID: 23601672 PMCID: PMC3684773 DOI: 10.1016/j.neurobiolaging.2013.03.015] [Citation(s) in RCA: 118] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2012] [Revised: 02/15/2013] [Accepted: 03/11/2013] [Indexed: 11/24/2022]
Abstract
Phosphorylated forms of microtubule-associated protein tau accumulate in neurofibrillary tangles in Alzheimer's disease. To investigate the effects of specific phosphorylated tau residues on its function, wild type or phosphomutant tau was expressed in cells. Elevated tau phosphorylation decreased its microtubule binding and bundling, and increased the number of motile tau particles, without affecting axonal transport kinetics. In contrast, reducing tau phosphorylation enhanced the amount of tau bound to microtubules and inhibited axonal transport of tau. To determine whether differential tau clearance is responsible for the increase in phosphomimic tau, we inhibited autophagy in neurons which resulted in a 3-fold accumulation of phosphomimic tau compared with wild type tau, and endogenous tau was unaffected. In autophagy-deficient mouse embryonic fibroblasts, but not in neurons, proteasomal degradation of phosphomutant tau was also reduced compared with wild type tau. Therefore, autophagic and proteasomal pathways are involved in tau degradation, with autophagy appearing to be the primary route for clearing phosphorylated tau in neurons. Defective autophagy might contribute to the accumulaton of tau in neurodegenerative diseases.
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Isoform transition from four-repeat to three-repeat tau underlies dendrosomatic and regional progression of neurofibrillary pathology. Acta Neuropathol 2013; 125:565-79. [PMID: 23407988 DOI: 10.1007/s00401-013-1097-6] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2012] [Accepted: 02/03/2013] [Indexed: 10/27/2022]
Abstract
Regional progression of neurofibrillary tangles (NFTs) around the hippocampus was traced on thick sections double immunofluorolabeled with RD3 and RD4 antibodies, specific for three- and four-repeat tau, respectively. As reported, the cubic density of all tau-positive neurons was predominant in the entorhinal cortex and cornu ammonis (CA)1, and decreased progressively to the CA2-4 subregions. Among the three isoform profiles (RD3+/4-, RD3+/4+, and RD3-/4+), this regional gradient was replicated with RD3+/4- and RD3+/4+ neurons, while RD3-/4+ neurons exhibited the reverse gradient. Comparison of the subregion pairs confirmed a consistent profile shift along this gradient in every case regardless of the abundance of NFTs. To clarify the underlying mechanism of this regional profile shift, intraneuronal intensity of RD3 and RD4 immunoreactivity (IR) was quantified. Although their intensities were both lower in dendrites than in the soma, this gradient was steeper with RD4, leaving RD3 IR in dendrites. Dendritic arborization was abundant in RD3-/4+ pretangles, attenuated in RD3+/4+ neurons, and further attenuated in RD3+/4- ghost tangles. These findings suggest that dendritic RD4 IR retracts first, leaving RD3 IR in the dendrites. Taken together, this dendrite-oriented retraction initiates the gradual shift from RD3-/4+ pretangle neurons to RD3+/4- ghost tangles by way of RD3+/4+ NFTs. This intraneuronal profile shift may be a basis for the regional gradation featured by the similar profile shift during progression of NFT pathology.
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Abstract
The lack or excess of the protein tau can be deleterious for neurons. The absence of tau can result in retarded neurogenesis and neuronal differentiation, although adult mice deficient in tau are viable, probably because of the compensation of the loss of tau by other MAPs (microtubule-associated proteins). On the contrary, the overexpression of tau can be toxic for the cell. One way to reduce intracellular tau levels can be achieved by its secretion through microvesicles to the extracellular space. Furthermore, tau can be found in the extracellular space because of the neuronal cell death occurring in neurodegenerative disorders such as Alzheimer's disease. The presence of toxic extracellular tau could be the mechanism for the spreading of tau pathology in these neurodegenerative disorders.
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43
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Aso E, Lomoio S, López‐González I, Joda L, Carmona M, Fernández‐Yagüe N, Moreno J, Juvés S, Pujol A, Pamplona R, Portero‐Otin M, Martín V, Díaz M, Ferrer I. Amyloid generation and dysfunctional immunoproteasome activation with disease progression in animal model of familial Alzheimer's disease. Brain Pathol 2012; 22:636-53. [PMID: 22188425 PMCID: PMC8057644 DOI: 10.1111/j.1750-3639.2011.00560.x] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2011] [Accepted: 12/12/2011] [Indexed: 12/16/2022] Open
Abstract
Double-transgenic amyloid precursor protein/presenilin 1 (APP/PS1) mice express a chimeric mouse/human APP bearing the Swedish mutation (Mo/HuAPP695swe) and a mutant human PS1-dE9 both causative of familial Alzheimer's disease (FAD). Transgenic mice show impaired memory and learning performance from the age of 6 months onwards. Double-transgenic APP/PS1 mice express altered APP and PS1 mRNAs and proteins, reduced β-secretase 1 (BACE1) mRNA and normal BACE1 protein, all of which suggest a particular mechanism of amyloidogenesis when compared with sporadic AD. The first β-amyloid plaques in APP/PS1 mice appear at 3 months, and they increase in number and distribution with disease progression in parallel with increased levels of brain soluble β-amyloid 1-42 and 1-40, but also with reduced 1-42/1-40 ratio with age. Amyloid deposition in plaques is accompanied by altered mitochondria and increased oxidative damage, post-translational modifications and accumulation of altered proteins at the dystrophic neurites surrounding plaques. Degradation pathways are also modified with disease progression including activation of the immunoproteasome together with variable alterations of the different protease activities of the ubiquitin-proteasome system. Present observations show modifications in the production of β-amyloid and activation and malfunction of the subcellular degradation pathways that have general implications in the pathogenesis of AD and more particularly in specificities of FAD amyloidogenesis.
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MESH Headings
- Age Factors
- Alzheimer Disease/complications
- Alzheimer Disease/genetics
- Alzheimer Disease/pathology
- Amyloid beta-Peptides/metabolism
- Amyloid beta-Protein Precursor/genetics
- Animals
- Aspartic Acid Endopeptidases/genetics
- Aspartic Acid Endopeptidases/metabolism
- Avoidance Learning/physiology
- Brain/metabolism
- Brain/pathology
- Brain/ultrastructure
- Cognition Disorders/etiology
- Cysteine Endopeptidases/metabolism
- Disease Models, Animal
- Disease Progression
- Gene Expression Regulation/genetics
- Humans
- Mice
- Mice, Inbred C57BL
- Mice, Transgenic
- Microscopy, Electron, Transmission
- Microscopy, Immunoelectron
- Mitogen-Activated Protein Kinases
- Mutation/genetics
- Neuropsychological Tests
- Plaque, Amyloid/metabolism
- Plaque, Amyloid/pathology
- Plaque, Amyloid/ultrastructure
- Presenilin-1/genetics
- Proteasome Endopeptidase Complex/genetics
- Proteasome Endopeptidase Complex/metabolism
- RNA, Messenger/metabolism
- Recognition, Psychology/physiology
- Signal Transduction/genetics
- Superoxide Dismutase/metabolism
- Superoxide Dismutase-1
- Ubiquitin Thiolesterase/metabolism
- alpha-Synuclein/metabolism
- tau Proteins/metabolism
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Affiliation(s)
- Ester Aso
- Institut de Neuropatologia, IDIBELL‐Hospital Universitari de Bellvitge, Universitat de Barcelona, Hospitalet de Llobregat; Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED), Barcelona, Spain
| | - Selene Lomoio
- Institut de Neuropatologia, IDIBELL‐Hospital Universitari de Bellvitge, Universitat de Barcelona, Hospitalet de Llobregat; Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED), Barcelona, Spain
- Dipartimento di Biologia Animale, Laboratorio di Biologia Cellulare e Neurobiologia, Università di Pavia, Pavia, Italy
| | - Irene López‐González
- Institut de Neuropatologia, IDIBELL‐Hospital Universitari de Bellvitge, Universitat de Barcelona, Hospitalet de Llobregat; Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED), Barcelona, Spain
| | - Laura Joda
- Institut de Neuropatologia, IDIBELL‐Hospital Universitari de Bellvitge, Universitat de Barcelona, Hospitalet de Llobregat; Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED), Barcelona, Spain
| | - Margarita Carmona
- Institut de Neuropatologia, IDIBELL‐Hospital Universitari de Bellvitge, Universitat de Barcelona, Hospitalet de Llobregat; Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED), Barcelona, Spain
| | - Núria Fernández‐Yagüe
- Institut de Neuropatologia, IDIBELL‐Hospital Universitari de Bellvitge, Universitat de Barcelona, Hospitalet de Llobregat; Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED), Barcelona, Spain
| | - Jesús Moreno
- Institut de Neuropatologia, IDIBELL‐Hospital Universitari de Bellvitge, Universitat de Barcelona, Hospitalet de Llobregat; Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED), Barcelona, Spain
| | - Salvador Juvés
- Institut de Neuropatologia, IDIBELL‐Hospital Universitari de Bellvitge, Universitat de Barcelona, Hospitalet de Llobregat; Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED), Barcelona, Spain
| | - Aurora Pujol
- Catalan Institution of Research and Advanced Studies (ICREA), Centre de Genètica Mèdica i Molecular, Institut d'Investigació Biomèdica de Bellvitge (IDIBELL), Hospitalet de Llobregat, Barcelona, Spain
| | - Reinald Pamplona
- Departament de Medicina Experimental, Universitat de Lleida‐IRBLleida, Lleida, Spain
| | - Manuel Portero‐Otin
- Departament de Medicina Experimental, Universitat de Lleida‐IRBLleida, Lleida, Spain
| | - Virginia Martín
- Laboratorio de Fisiología y Biofísica de Membranas, Departamento de Biología Animal e Instituto de Tecnologías Biomédicas, Universidad de La Laguna, Tenerife, Spain
| | - Mario Díaz
- Laboratorio de Fisiología y Biofísica de Membranas, Departamento de Biología Animal e Instituto de Tecnologías Biomédicas, Universidad de La Laguna, Tenerife, Spain
| | - Isidro Ferrer
- Institut de Neuropatologia, IDIBELL‐Hospital Universitari de Bellvitge, Universitat de Barcelona, Hospitalet de Llobregat; Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED), Barcelona, Spain
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44
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Rahman A, Khan KM, Al-Khaledi G, Khan I, Al-Shemary T. Over activation of hippocampal serine/threonine protein phosphatases PP1 and PP2A is involved in lead-induced deficits in learning and memory in young rats. Neurotoxicology 2012; 33:370-83. [DOI: 10.1016/j.neuro.2012.02.014] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2011] [Revised: 02/15/2012] [Accepted: 02/21/2012] [Indexed: 11/27/2022]
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45
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Tau Phosphorylation by GSK3 in Different Conditions. Int J Alzheimers Dis 2012; 2012:578373. [PMID: 22675648 PMCID: PMC3362846 DOI: 10.1155/2012/578373] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2012] [Accepted: 03/15/2012] [Indexed: 11/18/2022] Open
Abstract
Almost a 20% of the residues of tau protein are phosphorylatable amino acids: serine, threonine, and tyrosine. In this paper we comment on the consequences for tau of being a phosphoprotein. We will focus on serine/threonine phosphorylation. It will be discussed that, depending on the modified residue in tau molecule, phosphorylation could be protective, in processes like hibernation, or toxic like in development of those diseases known as tauopathies, which are characterized by an hyperphosphorylation and aggregation of tau.
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46
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Abstract
Tau is a microtubule-associated protein that fulfills several functions critical for neuronal formation and health. Tau discharges its functions by producing multiple isoforms via regulated alternative splicing. These isoforms modulate tau function in normal brain by altering the domains of the protein, thereby influencing its localization, conformation, and post-translational modifications and hence its availability and affinity for microtubules and other ligands. Disturbances in tau expression result in disruption of the neuronal cytoskeleton and formation of tau structures (neurofibrillary tangles) found in brains of dementia sufferers. More specifically, aberrations in tau splicing regulation directly cause several neurodegenerative diseases, which lead to dementia. In this review, I present our cumulative knowledge of tau splicing regulation in connection with neurodegeneration and also briefly go over the still-extensive list of questions that are connected to tau (dys)function.
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Affiliation(s)
- Athena Andreadis
- Department of Cell Biology, University of Massachusetts Medical School, Worcester, Massachusetts 01655, USA.
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47
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Polyansky A, Zagrovic B. Protein Electrostatic Properties Predefining the Level of Surface Hydrophobicity Change upon Phosphorylation. J Phys Chem Lett 2012; 3:973-976. [PMID: 23914287 PMCID: PMC3726239 DOI: 10.1021/jz300103p] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2012] [Accepted: 03/22/2012] [Indexed: 06/02/2023]
Abstract
We use explicit-solvent, molecular dynamics simulations to study the change in polar properties of a solvent-accessible surface for proteins undergoing phosphorylation. We analyze eight different pairs of proteins representing different structural classes in native and phosphorylated states and estimate the polarity of their surface using the molecular hydrophobicity potential approach. Whereas the phosphorylation-induced hydrophobicity change in the vicinity of phosphosites does not vary strongly among the studied proteins, the equivalent change for complete proteins covers a surprisingly wide range of effects including even an increase in the overall hydrophobicity in some cases. Importantly, the observed changes are strongly related to electrostatic properties of proteins, such as the net charge per residue, the distribution of charged side-chain contacts, and the isoelectric point. These features predefine the level of surface hydrophobicity change upon phosphorylation and may thus contribute to the phosphorylation-induced alteration of the interactions between a protein and its environment.
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Affiliation(s)
- Anton
A. Polyansky
- Department of Structural and Computational Biology, Max F. Perutz Laboratories, University of Vienna, Campus Vienna Biocenter 5, Vienna AT-1030, Austria
- M.M. Shemyakin and Yu.A. Ovchinnikov Institute
of Bioorganic Chemistry, Russian Academy of Sciences, Moscow 117997, Russia
- Mediterranean Institute for Life Sciences, Split, Croatia
| | - Bojan Zagrovic
- Department of Structural and Computational Biology, Max F. Perutz Laboratories, University of Vienna, Campus Vienna Biocenter 5, Vienna AT-1030, Austria
- Mediterranean Institute for Life Sciences, Split, Croatia
- Department of Physics, Faculty of Science, University of Split, Split, Croatia
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48
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Vardy ER, Kellett KA, Cocklin SL, Hooper NM. Alkaline Phosphatase Is Increased in both Brain and Plasma in Alzheimer’s Disease. NEURODEGENER DIS 2012; 9:31-7. [DOI: 10.1159/000329722] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2011] [Accepted: 05/30/2011] [Indexed: 11/19/2022] Open
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49
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Hanger DP, Noble W. Functional implications of glycogen synthase kinase-3-mediated tau phosphorylation. Int J Alzheimers Dis 2011; 2011:352805. [PMID: 21776376 PMCID: PMC3139124 DOI: 10.4061/2011/352805] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2011] [Accepted: 05/06/2011] [Indexed: 11/29/2022] Open
Abstract
Tau is primarily a neuronal microtubule-associated protein that has functions related to the stabilisation of microtubules. Phosphorylation of tau is an important dynamic and regulatory element involved in the binding of tau to tubulin. Thus, highly phosphorylated tau is more likely to be present in the cytosolic compartment of neurons, whereas reduced phosphate burden allows tau to bind to and stabilise the microtubule cytoskeleton. Highly phosphorylated forms of tau are deposited in the brain in a range of neurodegenerative disorders including Alzheimer's disease, progressive supranuclear palsy, and frontotemporal lobar degeneration associated with Pick bodies. A key candidate kinase for both physiological and pathological tau phosphorylation is glycogen synthase kinase-3 (GSK-3). Multiple phosphorylation sites have been identified on tau exposed to GSK-3 in vitro and in cells. In this review, we highlight recent data suggesting a role for GSK-3 activity on physiological tau function and on tau dysfunction in neurodegenerative disease.
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Affiliation(s)
- Diane P Hanger
- Department of Neuroscience (P037), MRC Centre for Neurodegeneration Research, King's College London, Institute of Psychiatry, De Crespigny Park, London SE5 8AF, UK
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50
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Pooler AM, Usardi A, Evans CJ, Philpott KL, Noble W, Hanger DP. Dynamic association of tau with neuronal membranes is regulated by phosphorylation. Neurobiol Aging 2011; 33:431.e27-38. [PMID: 21388709 DOI: 10.1016/j.neurobiolaging.2011.01.005] [Citation(s) in RCA: 100] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2010] [Revised: 12/10/2010] [Accepted: 01/15/2011] [Indexed: 10/18/2022]
Abstract
Tau is an abundant cytosolic protein which regulates cytoskeletal stability by associating with microtubules in a phosphorylation-dependent manner. We have found a significant proportion of tau is located in the membrane fraction of rat cortical neurons and is dephosphorylated, at least at Tau-1 (Ser199/Ser202), AT8 (Ser199/Ser202/Thr205) and PHF-1 (Ser396/Ser404) epitopes. Inhibition of tau kinases casein kinase 1 (CK1) or glycogen synthase kinase-3 decreased tau phosphorylation and significantly increased amounts of tau in the membrane fraction. Mutation of serine/threonine residues to glutamate to mimic phosphorylation in the N-terminal, but not C-terminal, region of tau prevented its membrane localization in transfected cells, demonstrating that the phosphorylation state of tau directly impacts its localization. Inhibiting CK1 in neurons lacking the tyrosine kinase fyn also induced tau dephosphorylation but did not affect its membrane association. Furthermore, inhibition of CK1 increased binding of neuronal tau to the fyn-SH3 domain. We conclude that trafficking of tau between the cytosol and the neuronal membrane is dynamically regulated by tau phosphorylation through a mechanism dependent on fyn expression.
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Affiliation(s)
- Amy M Pooler
- King's College London, MRC Centre for Neurodegeneration Research, Department of Neuroscience, Institute of Psychiatry, London, UK.
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