1
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Yamaguchi T, Hamano T, Sada K, Asano R, Kanaan NM, Sasaki H, Yen SH, Kitazaki Y, Endo Y, Enomoto S, Shirafuji N, Ikawa M, Yamamura O, Fujita Y, Aoki K, Naiki H, Morishima M, Saito Y, Murayama S, Nakamoto Y. Syk inhibitors reduce tau protein phosphorylation and oligomerization. Neurobiol Dis 2024; 201:106656. [PMID: 39233131 DOI: 10.1016/j.nbd.2024.106656] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2024] [Revised: 08/23/2024] [Accepted: 08/31/2024] [Indexed: 09/06/2024] Open
Abstract
Spleen tyrosine kinase (Syk), a non-receptor-type tyrosine kinase, has a wide range of physiological functions. A possible role of Syk in Alzheimer's disease (AD) has been proposed. We evaluated the localization of Syk in the brains of patients with AD and control participants. Human neuroblastoma M1C cells harboring wild-type tau (4R0N) were used with the tetracycline off (TetOff) induction system. In this model of neuronal tauopathy, the effects of the Syk inhibitors-BAY 61-3606 and R406-on tau phosphorylation and oligomerization were explored using several phosphorylated tau-specific antibodies and an oligomeric tau antibody, and the effects of these Syk inhibitors on autophagy were examined using western blot analyses. Moreover, the effects of the Syk inhibitor R406 were evaluated in vivo using wild-type mice. In AD brains, Syk and phosphorylated tau colocalized in the cytosol. In M1C cells, Syk protein (72 kDa) was detected using western blot analysis. Syk inhibitors decreased the expression levels of several tau phosphoepitopes including PHF-1, CP13, AT180, and AT270. Syk inhibitors also decreased the levels of caspase-cleaved tau (TauC3), a pathological tau form. Syk inhibitors increased inactivated glycogen synthase kinase 3β expression and decreased active p38 mitogen-activated protein kinase expression and demethylated protein phosphatase 2 A levels, indicating that Syk inhibitors inactivate tau kinases and activate tau phosphatases. Syk inhibitors also activated autophagy, as indicated by increased LC3II and decreased p62 levels. In vivo, the Syk inhibitor R406 decreased phosphorylated tau levels in wild-type mice. These findings suggest that Syk inhibitors offer novel therapeutic strategies for tauopathies, including AD.
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Affiliation(s)
- Tomohisa Yamaguchi
- Second Department of Internal Medicine, Faculty of Medical Sciences, University of Fukui, Fukui, Japan
| | - Tadanori Hamano
- Second Department of Internal Medicine, Faculty of Medical Sciences, University of Fukui, Fukui, Japan; Department of Aging and Dementia (DAD), Faculty of Medical Sciences, University of Fukui, Fukui, Japan; Life Science Innovation Center, University of Fukui, Fukui, Japan.
| | - Kiyonao Sada
- Department of Genome Science and Microbiology, Faculty of Medical Sciences, University of Fukui, Fukui, Japan
| | - Rei Asano
- Second Department of Internal Medicine, Faculty of Medical Sciences, University of Fukui, Fukui, Japan
| | - Nicholas M Kanaan
- Department of Translational Neuroscience, College of Human Medicine, Michigan State University, MI, USA
| | - Hirohito Sasaki
- Second Department of Internal Medicine, Faculty of Medical Sciences, University of Fukui, Fukui, Japan
| | - Shu-Hui Yen
- Department of Neuroscience, Mayo Clinic Jacksonville, FL, USA
| | - Yuki Kitazaki
- Second Department of Internal Medicine, Faculty of Medical Sciences, University of Fukui, Fukui, Japan
| | - Yoshinori Endo
- Second Department of Internal Medicine, Faculty of Medical Sciences, University of Fukui, Fukui, Japan
| | - Soichi Enomoto
- Second Department of Internal Medicine, Faculty of Medical Sciences, University of Fukui, Fukui, Japan
| | - Norimichi Shirafuji
- Second Department of Internal Medicine, Faculty of Medical Sciences, University of Fukui, Fukui, Japan
| | - Masamichi Ikawa
- Second Department of Internal Medicine, Faculty of Medical Sciences, University of Fukui, Fukui, Japan
| | - Osamu Yamamura
- Second Department of Internal Medicine, Faculty of Medical Sciences, University of Fukui, Fukui, Japan
| | - Youshi Fujita
- Department of Neurology, Fujita Neurological Hospital, Fukui, Japan
| | - Koji Aoki
- Department of Pharmacology, Faculty of Medical Sciences, University of Fukui, Fukui, Japan
| | - Hironobu Naiki
- Department of Molecular Pathology, Faculty of Medical Sciences, University of Fukui, Fukui, Japan
| | - Maho Morishima
- Brain Bank for Aging Research, Tokyo Metropolitan Institute for Geriatrics and Gerontology, Tokyo, Japan
| | - Yuko Saito
- Brain Bank for Aging Research, Tokyo Metropolitan Institute for Geriatrics and Gerontology, Tokyo, Japan
| | - Shigeo Murayama
- Brain Bank for Aging Research, Tokyo Metropolitan Institute for Geriatrics and Gerontology, Tokyo, Japan
| | - Yasunari Nakamoto
- Second Department of Internal Medicine, Faculty of Medical Sciences, University of Fukui, Fukui, Japan
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2
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Mansour HM. The interference between SARS-COV-2 and Alzheimer's disease: Potential immunological and neurobiological crosstalk from a kinase perspective reveals a delayed pandemic. Ageing Res Rev 2024; 94:102195. [PMID: 38244862 DOI: 10.1016/j.arr.2024.102195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Revised: 01/06/2024] [Accepted: 01/08/2024] [Indexed: 01/22/2024]
Abstract
Coronavirus disease 2019 (COVID-19) has infected over 700 million people, with up to 30% developing neurological manifestations, including dementias. However, there is a lack of understanding of common molecular brain markers causing Alzheimer's disease (AD). COVID-19 has etiological cofactors with AD, making patients with AD a vulnerable population at high risk of experiencing more severe symptoms and worse consequences. Both AD and COVID-19 have upregulated several shared kinases, leading to the repositioning of kinase inhibitors (KIs) for the treatment of both diseases. This review provides an overview of the interactions between the immune system and the nervous system in relation to receptor tyrosine kinases, including epidermal growth factor receptors, vascular growth factor receptors, and non-receptor tyrosine kinases such as Bruton tyrosine kinase, spleen tyrosine kinase, c-ABL, and JAK/STAT. We will discuss the promising results of kinase inhibitors in pre-clinical and clinical studies for both COVID-19 and Alzheimer's disease (AD), as well as the challenges in repositioning KIs for these diseases. Understanding the shared kinases between AD and COVID-19 could help in developing therapeutic approaches for both.
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Affiliation(s)
- Heba M Mansour
- General Administration of Innovative Products, Central Administration of Biological, Innovative Products, and Clinical Studies (Bio-INN), Egyptian Drug Authority (EDA), Giza, Egypt.
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3
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Lee G. Tau and signal transduction. Cytoskeleton (Hoboken) 2024; 81:103-106. [PMID: 38053488 DOI: 10.1002/cm.21814] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2023] [Revised: 11/24/2023] [Accepted: 11/25/2023] [Indexed: 12/07/2023]
Affiliation(s)
- Gloria Lee
- Department of Internal Medicine, Iowa Neuroscience Institute, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA
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4
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Hu Z, Chen PH, Li W, Douglas T, Hines J, Liu Y, Crews CM. Targeted Dephosphorylation of Tau by Phosphorylation Targeting Chimeras (PhosTACs) as a Therapeutic Modality. J Am Chem Soc 2023; 145:4045-4055. [PMID: 36753634 DOI: 10.1021/jacs.2c11706] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Abstract
Microtubule-associated protein tau is essential for microtubule assembly and stabilization. Hyperphosphorylation of the microtubule-associated protein tau plays an important pathological role in the development of Alzheimer's disease and other tauopathies. In vivo studies using kinase inhibitors suggest that reducing tau phosphorylation levels has therapeutic potential; however, such approaches showed limited benefits. We sought to further develop our phosphorylation targeting chimera (PhosTAC) technology to specifically induce tau dephosphorylation. Herein, we use small molecule-based PhosTACs to recruit tau to PP2A, a native tau phosphatase. PhosTACs induced the formation of a stable ternary complex, leading to rapid, efficient, and sustained tau dephosphorylation, which also correlated with the enhanced downregulation of tau protein. Mass spectrometry data validated that PhosTACs downregulated multiple phosphorylation sites of tau. We believe that PhosTAC possesses several advantages over current strategies to modulate tau phosphorylation and represents a new avenue for disease-modifying therapies for tauopathies.
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Affiliation(s)
- Zhenyi Hu
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, Connecticut 06511, United States
| | - Po-Han Chen
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, Connecticut 06511, United States
- Department of Biochemistry and Molecular Biology, College of Medicine, National Cheng Kung University, Tainan City 701, Taiwan
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan city 701, Taiwan
| | - Wenxue Li
- Yale Cancer Biology Institute, West Haven, Connecticut 06516, United States
| | - Todd Douglas
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, Connecticut 06511, United States
| | - John Hines
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, Connecticut 06511, United States
| | - Yansheng Liu
- Yale Cancer Biology Institute, West Haven, Connecticut 06516, United States
| | - Craig M Crews
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, Connecticut 06511, United States
- Department of Chemistry, Yale University, New Haven, Connecticut 06511, United States
- Department of Pharmacology, Yale University, New Haven, Connecticut 06511, United States
- Yale University School of Medicine, New Haven, Connecticut 06511, United States
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5
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Kao DS, Du Y, DeMarco AG, Min S, Hall MC, Rochet JC, Tao WA. Identification of Novel Kinases of Tau Using Fluorescence Complementation Mass Spectrometry (FCMS). Mol Cell Proteomics 2022; 21:100441. [PMID: 36379402 PMCID: PMC9755369 DOI: 10.1016/j.mcpro.2022.100441] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2022] [Revised: 11/09/2022] [Accepted: 11/10/2022] [Indexed: 11/15/2022] Open
Abstract
Hyperphosphorylation of the microtubule-associated protein Tau is a major hallmark of Alzheimer's disease and other tauopathies. Understanding the protein kinases that phosphorylate Tau is critical for the development of new drugs that target Tau phosphorylation. At present, the repertoire of the Tau kinases remains incomplete, and methods to uncover novel upstream protein kinases are still limited. Here, we apply our newly developed proteomic strategy, fluorescence complementation mass spectrometry, to identify novel kinase candidates of Tau. By constructing Tau- and kinase-fluorescent fragment library, we detected 59 Tau-associated kinases, including 23 known kinases of Tau and 36 novel candidate kinases. In the validation phase using in vitro phosphorylation, among 15 candidate kinases we attempted to purify and test, four candidate kinases, OXSR1 (oxidative-stress responsive gene 1), DAPK2 (death-associated protein kinase 2), CSK (C-terminal SRC kinase), and ZAP70 (zeta chain of T-cell receptor-associated protein kinase 70), displayed the ability to phosphorylate Tau in time-course experiments. Furthermore, coexpression of these four kinases along with Tau increased the phosphorylation of Tau in human neuroglioma H4 cells. We demonstrate that fluorescence complementation mass spectrometry is a powerful proteomic strategy to systematically identify potential kinases that can phosphorylate Tau in cells. Our discovery of new candidate kinases of Tau can present new opportunities for developing Alzheimer's disease therapeutic strategies.
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Affiliation(s)
- Der-Shyang Kao
- Department of Biochemistry, Purdue University, West Lafayette, Indiana, USA
| | - Yanyan Du
- Department of Biochemistry, Purdue University, West Lafayette, Indiana, USA
| | - Andrew G DeMarco
- Department of Biochemistry, Purdue University, West Lafayette, Indiana, USA
| | - Sehong Min
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, Indiana, USA
| | - Mark C Hall
- Department of Biochemistry, Purdue University, West Lafayette, Indiana, USA; Purdue Center for Cancer Research, Purdue University, West Lafayette, Indiana, USA
| | - Jean-Christophe Rochet
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, Indiana, USA; Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, Indiana, USA
| | - W Andy Tao
- Department of Biochemistry, Purdue University, West Lafayette, Indiana, USA; Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, Indiana, USA; Purdue Center for Cancer Research, Purdue University, West Lafayette, Indiana, USA; Department of Chemistry, Purdue University, West Lafayette, Indiana, USA.
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6
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Kumar R, Tiwari V, Dey S. Role of proline-rich tyrosine kinase 2 (Pyk2) in the pathogenesis of Alzheimer's disease. Eur J Neurosci 2022; 56:5442-5452. [PMID: 34905657 DOI: 10.1111/ejn.15569] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Revised: 12/02/2021] [Accepted: 12/03/2021] [Indexed: 12/14/2022]
Abstract
Alzheimer's disease (AD), a progressive neurodegenerative disorder, is the most common form of dementia in the elderly. Two major pathological hallmarks have been identified for AD: extracellular amyloid plaques and intracellular neurofibrillary tangles (NFT). Recently, proline-rich tyrosine kinase 2 (Pyk2), which belongs to the focal adhesion kinase (FAK) non-receptor tyrosine kinase family, was recognized to contribute significantly towards the pathogenesis of AD. Pyk2 can influence the formation of amyloid plaques as well as NFTs. The kinase can directly phosphorylate tau, which is a significant component of NFTs and enhances tau pathology. Several competitive inhibitors have been developed for Pyk2, tested in several cancer models, as Pyk2 is known to be overexpressed under those conditions. The current review article discusses the possible mechanistic pathways by which Pyk2 can influence the pathogenesis of AD. Besides, it describes various inhibitors for Pyk2 and their potential role as therapeutics for AD in the future.
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Affiliation(s)
- Rahul Kumar
- Department of Biotechnology, GITAM Institute of Sciences, GITAM University, Visakhapatnam, India
| | - Vishvanath Tiwari
- Department of Biochemistry, Central University of Rajasthan, Ajmer, India
| | - Sharmistha Dey
- Department of Biophysics, All India Institute of Medical Sciences, New Delhi, India
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7
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Bao Z, Liu J, Fu J. Comprehensive binary interaction mapping of τ phosphotyrosine sites with SH2 domains in the human genome: Implications for the rational design of self-inhibitory phosphopeptides to target τ hyperphosphorylation signaling in Alzheimer's Disease. Amino Acids 2022; 54:859-875. [PMID: 35622130 DOI: 10.1007/s00726-022-03171-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Accepted: 05/08/2022] [Indexed: 11/01/2022]
Abstract
Human microtubule-associated protein Tau (τ) is abundant in the axons of neurons where it stabilizes microtubule bundles; abnormally hyperphosphorylated τ is a hallmark of Alzheimer's disease (AD) and related tauopathies. The hyperphosphorylation events can be recognized by phosphotyrosine-recognition domain SH2 (Src homology 2) to elicit downstream τ signaling in AD pathology. In this study, a comprehensive binary interaction map (CBIM) of all the 6 τ phosphotyrosine sites with 120 SH2 domains in the human genome was systematically created at structural level using computational analyses and binding assays, from which we were able to identify those of strong and moderate binding pairs of sites to domains. It is found that the SH2-recognition specificity of different τ phosphotyrosine sites has been evolutionally optimized to become roughly orthogonal to each other, and thus these site phosphorylations would regulate different but probably partially overlapped biological functions in τ signaling. Some SH2 groups such as SRC, RIN, PLCG, SOCS and SH2D were revealed to have effective binding potency as compared to others; they could be regarded as potential τ-associated proteins to transduce the downstream signaling. We further determined the systematic binding affinities of 6 τ-phosphopeptides to the 11 SH2 domains in SRC group, from which the FYN-τ18 and YES-τ29 pairs were identified as strong binders. Subsequently, rational molecular design was performed on τ18 and τ29 to derive a number of τ-phosphopeptide mutants with increased affinity; they are self-inhibitory candidates to competitively target τ hyperphosphorylation events in AD. In addition, it is revealed that the primary anchor pY0 and secondary anchor X+3 of τ-phosphopeptides play an important role in SRC-group SH2 recognition, which confer stability and specificity to the SH2-phosphopeptide binding, respectively.
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Affiliation(s)
- Zhonglei Bao
- Department of Neurology, the Second Affiliated Hospital, Harbin Medical University, Harbin, 150086, China
| | - Jianghua Liu
- Department of Neurology, Daqing Oilfield General Hospital, Daqing, 163001, China
| | - Jin Fu
- Department of Neurology, the Second Affiliated Hospital, Harbin Medical University, Harbin, 150086, China.
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8
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Richens JL, Bramble JP, Spencer HL, Cantlay F, Butler M, O'Shea P. Towards defining the Mechanisms of Alzheimer's disease based on a contextual analysis of molecular pathways. AIMS GENETICS 2021. [DOI: 10.3934/genet.2016.1.25] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
AbstractAlzheimer's disease (AD) is posing an increasingly profound problem to society. Our genuine understanding of the pathogenesis of AD is inadequate and as a consequence, diagnostic and therapeutic strategies are currently insufficient. The understandable focus of many studies is the identification of molecules with high diagnostic utility however the opportunity to obtain a further understanding of the mechanistic origins of the disease from such putative biomarkers is often overlooked. This study examines the involvement of biomarkers in AD to shed light on potential mechanisms and pathways through which they are implicated in the pathology of this devastating neurodegenerative disorder. The computational tools required to analyse ever-growing datasets in the context of AD are also discussed.
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Affiliation(s)
- Joanna L. Richens
- Cell Biophysics Group, School of Life Sciences, University of Nottingham, University Park, Nottingham, United Kingdom
| | - Jonathan P. Bramble
- Cell Biophysics Group, School of Life Sciences, University of Nottingham, University Park, Nottingham, United Kingdom
| | - Hannah L. Spencer
- Cell Biophysics Group, School of Life Sciences, University of Nottingham, University Park, Nottingham, United Kingdom
| | - Fiona Cantlay
- Cell Biophysics Group, School of Life Sciences, University of Nottingham, University Park, Nottingham, United Kingdom
| | - Molly Butler
- Cell Biophysics Group, School of Life Sciences, University of Nottingham, University Park, Nottingham, United Kingdom
| | - Paul O'Shea
- Cell Biophysics Group, School of Life Sciences, University of Nottingham, University Park, Nottingham, United Kingdom
- Address as of 1st July 2016: Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, Canada
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9
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Mueller RL, Combs B, Alhadidy MM, Brady ST, Morfini GA, Kanaan NM. Tau: A Signaling Hub Protein. Front Mol Neurosci 2021; 14:647054. [PMID: 33815057 PMCID: PMC8017207 DOI: 10.3389/fnmol.2021.647054] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Accepted: 02/23/2021] [Indexed: 12/23/2022] Open
Abstract
Over four decades ago, in vitro experiments showed that tau protein interacts with and stabilizes microtubules in a phosphorylation-dependent manner. This observation fueled the widespread hypotheses that these properties extend to living neurons and that reduced stability of microtubules represents a major disease-driving event induced by pathological forms of tau in Alzheimer’s disease and other tauopathies. Accordingly, most research efforts to date have addressed this protein as a substrate, focusing on evaluating how specific mutations, phosphorylation, and other post-translational modifications impact its microtubule-binding and stabilizing properties. In contrast, fewer efforts were made to illuminate potential mechanisms linking physiological and disease-related forms of tau to the normal and pathological regulation of kinases and phosphatases. Here, we discuss published work indicating that, through interactions with various kinases and phosphatases, tau may normally act as a scaffolding protein to regulate phosphorylation-based signaling pathways. Expanding on this concept, we also review experimental evidence linking disease-related tau species to the misregulation of these pathways. Collectively, the available evidence supports the participation of tau in multiple cellular processes sustaining neuronal and glial function through various mechanisms involving the scaffolding and regulation of selected kinases and phosphatases at discrete subcellular compartments. The notion that the repertoire of tau functions includes a role as a signaling hub should widen our interpretation of experimental results and increase our understanding of tau biology in normal and disease conditions.
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Affiliation(s)
- Rebecca L Mueller
- Department of Translational Neuroscience, Michigan State University, Grand Rapids, MI, United States.,Neuroscience Program, Michigan State University, East Lansing, MI, United States
| | - Benjamin Combs
- Department of Translational Neuroscience, Michigan State University, Grand Rapids, MI, United States
| | - Mohammed M Alhadidy
- Department of Translational Neuroscience, Michigan State University, Grand Rapids, MI, United States.,Neuroscience Program, Michigan State University, East Lansing, MI, United States
| | - Scott T Brady
- Department of Anatomy and Cell Biology, The University of Illinois at Chicago, Chicago, IL, United States.,Marine Biological Laboratory, Woods Hole, MA, United States
| | - Gerardo A Morfini
- Department of Anatomy and Cell Biology, The University of Illinois at Chicago, Chicago, IL, United States.,Marine Biological Laboratory, Woods Hole, MA, United States
| | - Nicholas M Kanaan
- Department of Translational Neuroscience, Michigan State University, Grand Rapids, MI, United States.,Neuroscience Program, Michigan State University, East Lansing, MI, United States.,Hauenstein Neuroscience Center, Mercy Health Saint Mary's, Grand Rapids, MI, United States
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10
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Ait-Bouziad N, Chiki A, Limorenko G, Xiao S, Eliezer D, Lashuel HA. Phosphorylation of the overlooked tyrosine 310 regulates the structure, aggregation, and microtubule- and lipid-binding properties of Tau. J Biol Chem 2020; 295:7905-7922. [PMID: 32341125 PMCID: PMC7278352 DOI: 10.1074/jbc.ra119.012517] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Revised: 04/22/2020] [Indexed: 01/15/2023] Open
Abstract
The microtubule-associated protein Tau is implicated in the pathogenesis of several neurodegenerative disorders, including Alzheimer's disease. Increasing evidence suggests that post-translational modifications play critical roles in regulating Tau's normal functions and its pathogenic properties in tauopathies. Very little is known about how phosphorylation of tyrosine residues influences the structure, aggregation, and microtubule- and lipid-binding properties of Tau. Here, we sought to determine the relative contributions of phosphorylation of one or several of the five tyrosine residues in Tau (Tyr-18, -29, -197, -310, and -394) to the regulation of its biophysical, aggregation, and functional properties. We used a combination of site-specific mutagenesis and in vitro phosphorylation by c-Abl kinase to generate Tau species phosphorylated at all five tyrosine residues, all tyrosine residues except Tyr-310 or Tyr-394 (pTau-Y310F and pTau-Y394F, respectively) and Tau phosphorylated only at Tyr-310 or Tyr-394 (4F/pTyr-310 or 4F/pTyr-394). We observed that phosphorylation of all five tyrosine residues, multiple N-terminal tyrosine residues (Tyr-18, -29, and -197), or specific phosphorylation only at residue Tyr-310 abolishes Tau aggregation and inhibits its microtubule- and lipid-binding properties. NMR experiments indicated that these effects are mediated by a local decrease in β-sheet propensity of Tau's PHF6 domain. Our findings underscore Tyr-310 phosphorylation has a unique role in the regulation of Tau aggregation, microtubule, and lipid interactions. These results also highlight the importance of conducting further studies to elucidate the role of Tyr-310 in the regulation of Tau's normal functions and pathogenic properties.
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Affiliation(s)
- Nadine Ait-Bouziad
- Laboratory of Molecular and Chemical Biology of Neurodegeneration, Brain Mind Institute, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Anass Chiki
- Laboratory of Molecular and Chemical Biology of Neurodegeneration, Brain Mind Institute, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Galina Limorenko
- Laboratory of Molecular and Chemical Biology of Neurodegeneration, Brain Mind Institute, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Shifeng Xiao
- Shenzhen Key Laboratory of Marine Biotechnology and Ecology, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, China
- Department of Biochemistry and Program in Structural Biology, Weill Cornell Medical College, New York, New York
| | - David Eliezer
- Department of Biochemistry and Program in Structural Biology, Weill Cornell Medical College, New York, New York
| | - Hilal A Lashuel
- Laboratory of Molecular and Chemical Biology of Neurodegeneration, Brain Mind Institute, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
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11
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Li C, Götz J. Pyk2 is a Novel Tau Tyrosine Kinase that is Regulated by the Tyrosine Kinase Fyn. J Alzheimers Dis 2019; 64:205-221. [PMID: 29782321 PMCID: PMC6004899 DOI: 10.3233/jad-180054] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The protein tyrosine kinase Pyk2 is encoded by PTK2B, a novel Alzheimer’s disease (AD) susceptibility variant, with the PTK2B risk allele being associated with increased mRNA levels, suggestive of increased Pyk2 levels. However, the role of Pyk2, a member of the focal adhesion kinase (FAK) family, in AD pathology and its regulation are largely unknown. To address this, we generated mice with neuronal expression of human Pyk2. Because we had previously reported an association of Pyk2 and hyperphosphorylated tau (a hallmark feature of AD) in human tau transgenic pR5 mice, we also generated Pyk2/tau double-transgenic mice, which exhibit increased tyrosine phosphorylation and accumulation of tau. We further demonstrated that Pyk2 colocalizes, interacts with, and phosphorylates tau in vivo and in vitro. Importantly, although Pyk2 interacts with the established tyrosine-directed tau kinase Fyn, we identified an increased Pyk2 activity in mice which constitutively overexpress Fyn (FynCA), and a decreased activity in mice lacking Fyn (FynKO). Together, our study reveals a novel role for Pyk2 as a direct tyrosine kinase of tau that is active downstream of Fyn. Our analysis may enhance the understanding of how the PTK2B risk allele contributes to tauopathy.
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Affiliation(s)
- Chuanzhou Li
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, St Lucia Campus (Brisbane), QLD, Australia.,Department of Medical Genetics, School of Basic Medicine and Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Jürgen Götz
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, St Lucia Campus (Brisbane), QLD, Australia
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12
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Rad SK, Arya A, Karimian H, Madhavan P, Rizwan F, Koshy S, Prabhu G. Mechanism involved in insulin resistance via accumulation of β-amyloid and neurofibrillary tangles: link between type 2 diabetes and Alzheimer's disease. Drug Des Devel Ther 2018; 12:3999-4021. [PMID: 30538427 PMCID: PMC6255119 DOI: 10.2147/dddt.s173970] [Citation(s) in RCA: 85] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The pathophysiological link between type 2 diabetes mellitus (T2DM) and Alzheimer's disease (AD) has been suggested in several reports. Few findings suggest that T2DM has strong link in the development process of AD, and the complete mechanism is yet to be revealed. Formation of amyloid plaques (APs) and neurofibrillary tangles (NFTs) are two central hallmarks in the AD. APs are the dense composites of β-amyloid protein (Aβ) which accumulates around the nerve cells. Moreover, NFTs are the twisted fibers containing hyperphosphorylated tau proteins present in certain residues of Aβ that build up inside the brain cells. Certain factors contribute to the aetiogenesis of AD by regulating insulin signaling pathway in the brain and accelerating the formation of neurotoxic Aβ and NFTs via various mechanisms, including GSK3β, JNK, CamKII, CDK5, CK1, MARK4, PLK2, Syk, DYRK1A, PPP, and P70S6K. Progression to AD could be influenced by insulin signaling pathway that is affected due to T2DM. Interestingly, NFTs and APs lead to the impairment of several crucial cascades, such as synaptogenesis, neurotrophy, and apoptosis, which are regulated by insulin, cholesterol, and glucose metabolism. The investigation of the molecular cascades through insulin functions in brain contributes to probe and perceive progressions of diabetes to AD. This review elaborates the molecular insights that would help to further understand the potential mechanisms linking T2DM and AD.
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Affiliation(s)
- Sima Kianpour Rad
- Department of Molecular Medicine, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Aditya Arya
- Department of Pharmacology and Therapeutics, School of Medicine, Faculty of Health and Medical Sciences, Taylor's University, Subang Jaya, Malaysia,
- Department of Pharmacology and Therapeutics, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Parkville, VIC, Australia,
- Malaysian Institute of Pharmaceuticals and Nutraceuticals (IPharm), Bukit Gambir, Gelugor, Pulau Pinang, Malaysia,
| | - Hamed Karimian
- Department of Pharmacology and Therapeutics, School of Medicine, Faculty of Health and Medical Sciences, Taylor's University, Subang Jaya, Malaysia,
| | - Priya Madhavan
- School of Medicine, Faculty of Health and Medical Sciences, Taylor's University, Subang Jaya, Malaysia
| | - Farzana Rizwan
- School of Medicine, Faculty of Health and Medical Sciences, Taylor's University, Subang Jaya, Malaysia
| | - Shajan Koshy
- School of Medicine, Faculty of Health and Medical Sciences, Taylor's University, Subang Jaya, Malaysia
| | - Girish Prabhu
- School of Medicine, Faculty of Health and Medical Sciences, Taylor's University, Subang Jaya, Malaysia
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13
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Amyloid-β oligomers synaptotoxicity: The emerging role of EphA4/c-Abl signaling in Alzheimer's disease. Biochim Biophys Acta Mol Basis Dis 2018; 1864:1148-1159. [DOI: 10.1016/j.bbadis.2018.01.023] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Revised: 01/12/2018] [Accepted: 01/23/2018] [Indexed: 12/11/2022]
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14
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Ferguson SA, Mouzon BC, Lynch C, Lungmus C, Morin A, Crynen G, Carper B, Bieler G, Mufson EJ, Stewart W, Mullan M, Crawford F. Negative Impact of Female Sex on Outcomes from Repetitive Mild Traumatic Brain Injury in hTau Mice Is Age Dependent: A Chronic Effects of Neurotrauma Consortium Study. Front Aging Neurosci 2017; 9:416. [PMID: 29311903 PMCID: PMC5744460 DOI: 10.3389/fnagi.2017.00416] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Accepted: 12/04/2017] [Indexed: 11/13/2022] Open
Abstract
Traumatic brain injury (TBI) is a serious public health concern which strikes someone every 15 s on average in the US. Even mild TBI, which comprise as many as 75% of all TBI cases, carries long term consequences. The effects of age and sex on long term outcome from TBI is not fully understood, but due to the increased risk for neurodegenerative diseases after TBI it is important to understand how these factors influence the outcome from TBI. This study examined the neurobehavioral and neuropathological effects of age and sex on the outcome 15 days following repetitive mild traumatic brain injury (r-mTBI) in mice transgenic for human tau (hTau). These mice express the six human isoforms of tau but do not express endogenous murine tau and they develop tau pathology and memory impairment in an age-dependent manner. After 5 mild impacts, aged female mice showed motor impairments that were absent in aged male mice, as well as younger animals. Conversely, aged female sham mice outperformed all other groups of aged mice in a Barnes maze spatial memory test. Pathologically, increases in IBA-1 and GFAP staining typically seen in this model of r-mTBI showed the expected increases with both injury and age, but phosphorylated tau stained with CP13 in the hippocampus (reduced in female sham mice compared to males) and PHF1 in the cortex (reduced in female TBI mice compared to male TBI mice) showed the only histological signs of sex-dependent differences in these mice.
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Affiliation(s)
- Scott A Ferguson
- Roskamp Institute, Sarasota, FL, United States.,James A. Haley Veterans' Hospital, Tampa, FL, United States
| | - Benoit C Mouzon
- Roskamp Institute, Sarasota, FL, United States.,James A. Haley Veterans' Hospital, Tampa, FL, United States
| | | | | | | | | | - Benjamin Carper
- RTI International, Research Triangle Park, NC, United States
| | - Gayle Bieler
- RTI International, Research Triangle Park, NC, United States
| | - Elliott J Mufson
- Department of Neurobiology, Barrow Neurological Institute, Phoenix, AZ, United States
| | - William Stewart
- Queen Elizabeth Glasgow University Hospital, Glasgow, United Kingdom.,Institute of Neuroscience and Psychology, University of Glasgow, Glasgow, United Kingdom
| | | | - Fiona Crawford
- Roskamp Institute, Sarasota, FL, United States.,James A. Haley Veterans' Hospital, Tampa, FL, United States
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15
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Köhler C, Fuhr V, Dinekov M. Distribution of spleen tyrosine kinase and tau phosphorylated at tyrosine 18 in a mouse model of tauopathy and in the human hippocampus. Brain Res 2017; 1677:1-13. [DOI: 10.1016/j.brainres.2017.08.029] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Revised: 08/11/2017] [Accepted: 08/25/2017] [Indexed: 12/01/2022]
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16
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Oliveira J, Costa M, de Almeida MSC, da Cruz e Silva OA, Henriques AG. Protein Phosphorylation is a Key Mechanism in Alzheimer’s Disease. J Alzheimers Dis 2017; 58:953-978. [DOI: 10.3233/jad-170176] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Joana Oliveira
- Department of Medical Sciences, Neuroscience and Signalling Laboratory, iBiMED, University of Aveiro, Aveiro, Portugal
| | - Márcio Costa
- Department of Medical Sciences, Neuroscience and Signalling Laboratory, iBiMED, University of Aveiro, Aveiro, Portugal
| | | | - Odete A.B. da Cruz e Silva
- Department of Medical Sciences, Neuroscience and Signalling Laboratory, iBiMED, University of Aveiro, Aveiro, Portugal
| | - Ana Gabriela Henriques
- Department of Medical Sciences, Neuroscience and Signalling Laboratory, iBiMED, University of Aveiro, Aveiro, Portugal
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17
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Radiofluorination process development and Tau protein imaging studies of [F-18]FEONM. J Taiwan Inst Chem Eng 2016. [DOI: 10.1016/j.jtice.2016.09.035] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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18
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Granulovacuolar degeneration: a neurodegenerative change that accompanies tau pathology. Acta Neuropathol 2016; 132:339-59. [PMID: 27062260 DOI: 10.1007/s00401-016-1562-0] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Revised: 03/08/2016] [Accepted: 03/14/2016] [Indexed: 10/22/2022]
Abstract
Granule-containing vacuoles in the cytoplasm of hippocampal neurons are a neuropathological feature of Alzheimer's disease. Granulovacuolar degeneration (GVD) is not disease-specific and can be observed in other neurodegenerative disorders and even in the brains of non-demented elderly people. However, several studies have reported much higher numbers of neurons undergoing GVD in the hippocampus of Alzheimer's disease cases. Recently, a neuropathological staging system for GVD has facilitated neuropathological assessment. Data obtained by electron microscopy and immunolabeling suggest that GVD inclusions are a special form of autophagic vacuole. GVD frequently occurs together with pathological changes of the microtubule-associated protein tau, but to date, the relationship between the two lesions remains elusive. Originally identified in hematoxylin- and silver-stained sections, immunolabeling has shown that the granules are composed of a variety of proteins, including those related to tau pathology, autophagy, diverse signal transduction pathways, cell stress and apoptosis. Several of these proteins serve as markers of GVD. Most researchers and authors have interpreted the sequestration of proteins into GVD inclusions as either a cellular defense mechanism or one that leads to the impairment of important cellular functions. This review provides a detailed overview of the various aspects of GVD and focuses on the relationship between tau pathology and GVD.
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19
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Nishikawa T, Takahashi T, Nakamori M, Hosomi N, Maruyama H, Miyazaki Y, Izumi Y, Matsumoto M. The identification of raft-derived tau-associated vesicles that are incorporated into immature tangles and paired helical filaments. Neuropathol Appl Neurobiol 2015; 42:639-653. [PMID: 26501932 DOI: 10.1111/nan.12288] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Revised: 10/07/2015] [Accepted: 10/26/2015] [Indexed: 12/14/2022]
Abstract
AIMS Neurofibrillary tangles (NFTs), a cardinal pathological feature of neurodegenerative disorders, such as Alzheimer's disease (AD) are primarily composed of hyper-phosphorylated tau protein. Recently, several other molecules, including flotillin-1, phosphatidylinositol-4,5-bisphosphate [PtdIns(4,5)P2] and cyclin-dependent kinase 5 (CDK5), have also been revealed as constituents of NFTs. Flotillin-1 and PtdIns(4,5)P2 are considered markers of raft microdomains, whereas CDK5 is a tau kinase. Therefore, we hypothesized that NFTs have a relationship with raft domains and the tau phosphorylation that occurs within NFTs. METHODS We investigated six cases of AD, six cases of other neurodegenerative diseases with NFTs and three control cases. We analysed the PtdIns(4,5)P2-immunopositive material in detail, using super-resolution microscopy and electron microscopy to elucidate its pattern of expression. We also investigated the spatial relationship between the PtdIns(4,5)P2-immunopositive material and tau kinases through double immunofluorescence analysis. RESULTS Pretangles contained either paired helical filaments (PHFs) or PtdIns(4,5)P2-immunopositive small vesicles (approximately 1 μm in diameter) with nearly identical topology to granulovacuolar degeneration (GVD) bodies. Various combinations of these vesicles and GVD bodies, the latter of which are pathological hallmarks observed within the neurons of AD patients, were found concurrently in neurons. These vesicles and GVD bodies were both immunopositive not only for PtdIns(4,5)P2, but also for several tau kinases such as glycogen synthase kinase-3β and spleen tyrosine kinase. CONCLUSIONS These observations suggest that clusters of raft-derived vesicles that resemble GVD bodies are substructures of pretangles other than PHFs. These tau kinase-bearing vesicles are likely involved in the modification of tau protein and in NFT formation.
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Affiliation(s)
- T Nishikawa
- Department of Clinical Neuroscience and Therapeutics, Hiroshima University Graduate School of Biomedical and Health Sciences, Hiroshima, Japan
| | - T Takahashi
- Department of Clinical Neuroscience and Therapeutics, Hiroshima University Graduate School of Biomedical and Health Sciences, Hiroshima, Japan
| | - M Nakamori
- Department of Clinical Neuroscience and Therapeutics, Hiroshima University Graduate School of Biomedical and Health Sciences, Hiroshima, Japan
| | - N Hosomi
- Department of Clinical Neuroscience and Therapeutics, Hiroshima University Graduate School of Biomedical and Health Sciences, Hiroshima, Japan
| | - H Maruyama
- Department of Clinical Neuroscience and Therapeutics, Hiroshima University Graduate School of Biomedical and Health Sciences, Hiroshima, Japan
| | - Y Miyazaki
- Department of Clinical Neuroscience, Institute of Health Biosciences, Graduate School of Medicine, University of Tokushima, Tokushima, Japan
| | - Y Izumi
- Department of Clinical Neuroscience, Institute of Health Biosciences, Graduate School of Medicine, University of Tokushima, Tokushima, Japan
| | - M Matsumoto
- Department of Clinical Neuroscience and Therapeutics, Hiroshima University Graduate School of Biomedical and Health Sciences, Hiroshima, Japan
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20
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Secchi C, Carta M, Crescio C, Spano A, Arras M, Caocci G, Galimi F, La Nasa G, Pippia P, Turrini F, Pantaleo A. T cell tyrosine phosphorylation response to transient redox stress. Cell Signal 2015; 27:777-88. [PMID: 25572700 DOI: 10.1016/j.cellsig.2014.12.014] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2014] [Revised: 12/09/2014] [Accepted: 12/24/2014] [Indexed: 12/29/2022]
Abstract
Reactive Oxygen Species (ROS) are crucial to multiple biological processes involved in the pathophysiology of inflammation, and are also involved in redox signaling responses. Although previous reports have described an association between oxidative events and the modulation of innate immunity, a role for redox signaling in T cell mediated adaptive immunity has not been described yet. This work aims at assessing if T cells can sense redox stress through protein sulfhydryl oxidation and respond with tyrosine phosphorylation changes. Our data show that Jurkat T cells respond to -SH group oxidation with specific tyrosine phosphorylation events. The release of T cell cytokines TNF, IFNγ and IL2 as well as the expression of a number of receptors are affected by those changes. Additionally, experiments with spleen tyrosine kinase (Syk) inhibitors showed a major involvement of Syk in these responses. The experiments described herein show a link between cysteine oxidation and tyrosine phosphorylation changes in T cells, as well as a novel mechanism by which Syk inhibitors exert their anti-inflammatory activity through the inhibition of a response initiated by ROS.
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Affiliation(s)
- Christian Secchi
- Department of Biomedical Sciences, University of Sassari, I-07100 Sassari, Italy; Istituto Nazionale Biostrutture e Biosistemi, University of Sassari, I-07100, Sassari, Italy
| | - Marissa Carta
- Department of Biomedical Sciences, University of Sassari, I-07100 Sassari, Italy
| | - Claudia Crescio
- Department of Biomedical Sciences, University of Sassari, I-07100 Sassari, Italy
| | - Alessandra Spano
- Department of Biomedical Sciences, University of Sassari, I-07100 Sassari, Italy
| | - Marcella Arras
- Haematology, Hospital Binaghi, ASL 8 Cagliari, I-09126, Cagliari, Italy
| | - Giovanni Caocci
- Haematology, Department of Medical Sciences, University of Cagliari, I-09042 Cagliari, Italy
| | - Francesco Galimi
- Department of Biomedical Sciences, University of Sassari, I-07100 Sassari, Italy; Istituto Nazionale Biostrutture e Biosistemi, University of Sassari, I-07100, Sassari, Italy
| | - Giorgio La Nasa
- Haematology, Department of Medical Sciences, University of Cagliari, I-09042 Cagliari, Italy
| | - Proto Pippia
- Department of Biomedical Sciences, University of Sassari, I-07100 Sassari, Italy
| | - Francesco Turrini
- Department of Genetics, Biology and Biochemistry, University of Turin, I-10126 Turin, Italy
| | - Antonella Pantaleo
- Department of Biomedical Sciences, University of Sassari, I-07100 Sassari, Italy.
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21
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Paris D, Ait-Ghezala G, Bachmeier C, Laco G, Beaulieu-Abdelahad D, Lin Y, Jin C, Crawford F, Mullan M. The spleen tyrosine kinase (Syk) regulates Alzheimer amyloid-β production and Tau hyperphosphorylation. J Biol Chem 2014; 289:33927-44. [PMID: 25331948 DOI: 10.1074/jbc.m114.608091] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
We have previously shown that the L-type calcium channel (LCC) antagonist nilvadipine reduces brain amyloid-β (Aβ) accumulation by affecting both Aβ production and Aβ clearance across the blood-brain barrier (BBB). Nilvadipine consists of a mixture of two enantiomers, (+)-nilvadipine and (-)-nilvadipine, in equal proportion. (+)-Nilvadipine is the active enantiomer responsible for the inhibition of LCC, whereas (-)-nilvadipine is considered inactive. Both nilvadipine enantiomers inhibit Aβ production and improve the clearance of Aβ across the BBB showing that these effects are not related to LCC inhibition. In addition, treatment of P301S mutant human Tau transgenic mice (transgenic Tau P301S) with (-)-nilvadipine reduces Tau hyperphosphorylation at several Alzheimer disease (AD) pertinent epitopes. A search for the mechanism of action of (-)-nilvadipine revealed that this compound inhibits the spleen tyrosine kinase (Syk). We further validated Syk as a target-regulating Aβ by showing that pharmacological inhibition of Syk or down-regulation of Syk expression reduces Aβ production and increases the clearance of Aβ across the BBB mimicking (-)-nilvadipine effects. Moreover, treatment of transgenic mice overexpressing Aβ and transgenic Tau P301S mice with a selective Syk inhibitor respectively decreased brain Aβ accumulation and Tau hyperphosphorylation at multiple AD relevant epitopes. We show that Syk inhibition induces an increased phosphorylation of the inhibitory Ser-9 residue of glycogen synthase kinase-3β, a primary Tau kinase involved in Tau phosphorylation, by activating protein kinase A, providing a mechanism explaining the reduction of Tau phosphorylation at GSK3β-dependent epitopes following Syk inhibition. Altogether our data highlight Syk as a promising target for preventing both Aβ accumulation and Tau hyperphosphorylation in AD.
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Affiliation(s)
- Daniel Paris
- From the Roskamp Institute, Sarasota, Florida 34243
| | | | | | - Gary Laco
- From the Roskamp Institute, Sarasota, Florida 34243
| | | | - Yong Lin
- From the Roskamp Institute, Sarasota, Florida 34243
| | - Chao Jin
- From the Roskamp Institute, Sarasota, Florida 34243
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22
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Uckun FM, Qazi S. Spleen tyrosine kinase as a molecular target for treatment of leukemias and lymphomas. Expert Rev Anticancer Ther 2014; 10:1407-18. [DOI: 10.1586/era.10.112] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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23
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Comprehensive gene expression profiling reveals synergistic functional networks in cerebral vessels after hypertension or hypercholesterolemia. PLoS One 2013; 8:e68335. [PMID: 23874591 PMCID: PMC3712983 DOI: 10.1371/journal.pone.0068335] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2013] [Accepted: 05/28/2013] [Indexed: 01/09/2023] Open
Abstract
Atherosclerotic stenosis of cerebral arteries or intracranial large artery disease (ICLAD) is a major cause of stroke especially in Asians, Hispanics and Africans, but relatively little is known about gene expression changes in vessels at risk. This study compares comprehensive gene expression profiles in the middle cerebral artery (MCA) of New Zealand White rabbits exposed to two stroke risk factors i.e. hypertension and/or hypercholesterolemia, by the 2-Kidney-1-Clip method, or dietary supplementation with cholesterol. Microarray and Ingenuity Pathway Analyses of the MCA of the hypertensive rabbits showed up-regulated genes in networks containing the node molecules: UBC (ubiquitin), P38 MAPK, ERK, NFkB, SERPINB2, MMP1 and APP (amyloid precursor protein); and down-regulated genes related to MAPK, ERK 1/2, Akt, 26 s proteasome, histone H3 and UBC. The MCA of hypercholesterolemic rabbits showed differentially expressed genes that are surprisingly, linked to almost the same node molecules as the hypertensive rabbits, despite a relatively low percentage of ‘common genes’ (21 and 7%) between the two conditions. Up-regulated common genes were related to: UBC, SERPINB2, TNF, HNF4A (hepatocyte nuclear factor 4A) and APP, and down-regulated genes, related to UBC. Increased HNF4A message and protein were verified in the aorta. Together, these findings reveal similar nodal molecules and gene pathways in cerebral vessels affected by hypertension or hypercholesterolemia, which could be a basis for synergistic action of risk factors in the pathogenesis of ICLAD.
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24
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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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25
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Tau protein kinases: involvement in Alzheimer's disease. Ageing Res Rev 2013; 12:289-309. [PMID: 22742992 DOI: 10.1016/j.arr.2012.06.003] [Citation(s) in RCA: 423] [Impact Index Per Article: 38.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2012] [Revised: 05/21/2012] [Accepted: 06/06/2012] [Indexed: 02/07/2023]
Abstract
Tau phosphorylation is regulated by a balance between tau kinase and phosphatase activities. Disruption of this equilibrium was suggested to be at the origin of abnormal tau phosphorylation and thereby might contribute to tau aggregation. Thus, understanding the regulation modes of tau phosphorylation is of high interest in determining the possible causes at the origin of the formation of tau aggregates in order to elaborate protection strategies to cope with these lesions in Alzheimer's disease. Among the possible and specific interventions that reverse tau phosphorylation is the inhibition of certain tau kinases. Here, we extensively reviewed tau protein kinases, their physiological roles and regulation, their involvement in tau phosphorylation and their relevance to AD. We also reviewed the most common inhibitory compounds acting on each tau kinase.
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26
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Martin L, Latypova X, Wilson CM, Magnaudeix A, Perrin ML, Terro F. Tau protein phosphatases in Alzheimer's disease: the leading role of PP2A. Ageing Res Rev 2013; 12:39-49. [PMID: 22771380 DOI: 10.1016/j.arr.2012.06.008] [Citation(s) in RCA: 160] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2012] [Accepted: 06/28/2012] [Indexed: 12/21/2022]
Abstract
Tau phosphorylation is regulated by a balance between tau kinase and phosphatase activities. Disruption of this equilibrium was suggested to be at the origin of abnormal tau phosphorylation and thereby that might contributes to tau aggregation. Thus, understanding the regulation modes of tau dephosphorylation is of high interest in determining the possible causes at the origin of the formation of tau aggregates and to elaborate protection strategies to cope with these lesions in AD. Among the possible and relatively specific interventions that reverse tau phosphorylation is the stimulation of certain tau phosphatases. Here, we reviewed tau protein phosphatases, their physiological roles and regulation, their involvement in tau phosphorylation and the relevance to AD. We also reviewed the most common compounds acting on each tau phosphatase including PP2A.
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Affiliation(s)
- Ludovic Martin
- Groupe de Neurobiologie Cellulaire, Homéostasie cellulaire et pathologies, Faculté de Médecine, Limoges, France.
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27
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Liang D, Han G, Feng X, Sun J, Duan Y, Lei H. Concerted perturbation observed in a hub network in Alzheimer's disease. PLoS One 2012; 7:e40498. [PMID: 22815752 PMCID: PMC3398025 DOI: 10.1371/journal.pone.0040498] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2011] [Accepted: 06/11/2012] [Indexed: 12/31/2022] Open
Abstract
Alzheimer’s disease (AD) is a progressive neurodegenerative disease involving the alteration of gene expression at the whole genome level. Genome-wide transcriptional profiling of AD has been conducted by many groups on several relevant brain regions. However, identifying the most critical dys-regulated genes has been challenging. In this work, we addressed this issue by deriving critical genes from perturbed subnetworks. Using a recent microarray dataset on six brain regions, we applied a heaviest induced subgraph algorithm with a modular scoring function to reveal the significantly perturbed subnetwork in each brain region. These perturbed subnetworks were found to be significantly overlapped with each other. Furthermore, the hub genes from these perturbed subnetworks formed a connected hub network consisting of 136 genes. Comparison between AD and several related diseases demonstrated that the hub network was robustly and specifically perturbed in AD. In addition, strong correlation between the expression level of these hub genes and indicators of AD severity suggested that this hub network can partially reflect AD progression. More importantly, this hub network reflected the adaptation of neurons to the AD-specific microenvironment through a variety of adjustments, including reduction of neuronal and synaptic activities and alteration of survival signaling. Therefore, it is potentially useful for the development of biomarkers and network medicine for AD.
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Affiliation(s)
- Dapeng Liang
- CAS key laboratory of genome sciences and information, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, China
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28
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Abstract
Tauopathies are age-related neurodegenerative diseases that are characterized by the presence of aggregates of abnormally phosphorylated tau. As tau was originally discovered as a microtubule-associated protein, it has been hypothesized that neurodegeneration results from a loss of the ability of tau to associate with microtubules. However, tau has been found to have other functions aside from the promotion and stabilization of microtubule assembly. It is conceivable that such functions may be affected by the abnormal phosphorylation of tau and might have consequences for neuronal function or viability. This chapter provides an overview of tau structure, functions, and its involvement in neurodegenerative diseases.
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29
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Satoh JI, Tabunoki H, Ishida T, Yagishita S, Jinnai K, Futamura N, Kobayashi M, Toyoshima I, Yoshioka T, Enomoto K, Arai N, Saito Y, Arima K. Phosphorylated Syk expression is enhanced in Nasu-Hakola disease brains. Neuropathology 2011; 32:149-57. [PMID: 21981270 DOI: 10.1111/j.1440-1789.2011.01256.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Nasu-Hakola disease (NHD) is a rare autosomal recessive disorder, characterized by progressive presenile dementia and formation of multifocal bone cysts, caused by a loss-of-function mutation of DNAX-activation protein 12 (DAP12) or triggering receptor expressed on myeloid cells 2 (TREM2). TREM2 and DAP12 constitute a receptor/adaptor complex on myeloid cells. The post-receptor signals are transmitted via rapid phosphorylation of the immunoreceptor tyrosine-based activating motif (ITAM) of DAP12, mediated by Src protein tyrosine kinases, followed by binding of phosphorylated ITAM to Src homology 2 (SH2) domains of spleen tyrosine kinase (Syk), resulting in autophosphorylation of the activation loop of Syk. To elucidate the molecular mechanism underlying the pathogenesis of NHD, we investigated Syk expression and activation in the frontal cortex and the hippocampus of three NHD and eight control brains by immunohistochemistry. In NHD brains, the majority of neurons expressed intense immunoreactivities for Syk and Y525/Y526-phosphorylated Syk (pSyk) chiefly located in the cytoplasm, while more limited populations of neurons expressed Src. The levels of pSyk expression were elevated significantly in NHD brains compared with control brains. In both NHD and control brains, substantial populations of microglia and macrophages expressed pSyk, while the great majority of reactive astrocytes and myelinating oligodendrocytes did not express pSyk, Syk or Src. These observations indicate that neuronal expression of pSyk was greatly enhanced in the cerebral cortex and the hippocampus of NHD brains, possibly via non-TREM2/DAP12 signaling pathways involved in Syk activation.
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Affiliation(s)
- Jun-Ichi Satoh
- Department of Bioinformatics and Molecular Neuropathology, Meiji Pharmaceutical University Department of Clinical Neuropathology, Tokyo, Japan.
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30
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Hatterer E, Benon A, Chounlamountri N, Watrin C, Angibaud J, Jouanneau E, Boudin H, Honnorat J, Pellier-Monnin V, Noraz N. Syk kinase is phosphorylated in specific areas of the developing nervous system. Neurosci Res 2011; 70:172-82. [PMID: 21354221 DOI: 10.1016/j.neures.2011.02.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2010] [Revised: 01/31/2011] [Accepted: 02/16/2011] [Indexed: 11/26/2022]
Abstract
An increasing number of data involve immunoreceptors in brain development, synaptic plasticity and behavior. However it has yet to be determined whether these proteins in fact transmit an immunoreceptor-like signal in non-hematopoietic neuronal cells. The recruitment and activation of the Syk family tyrosine kinases, Syk and ZAP-70, being a critical step in this process, we conducted a thorough analysis of Syk/ZAP-70 expression pattern in nervous tissues. Syk/ZAP-70 is present in neurons of different structures including the cerebellum, the hippocampus, the visual system and the olfactory system. During the olfactory system ontogeny the protein is detected from the 16th embryonic day and persists in adulthood. Importantly, Syk was phosphorylated on tyrosine residues representative of an active form of the kinase in specialized neuronal subpopulations comprising rostral migratory stream neuronal progenitor cells, hippocampal pyramidal cells, retinal ganglion cells and cerebellar granular cells. Phospho-Syk staining was also observed in synapse-rich regions such as the olfactory bulb glomeruli and the retina inner plexiform layer. Furthermore, our work on cultured primary hippoccampal neurons indicates that as for hematopoietic cells, Syk phosphorylation is readily induced upon pervanadate treatment. Therefore, Syk appears to be a serious candidate in connecting immunoreceptors to downstream adaptor/effector molecules in neurons.
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Affiliation(s)
- Eric Hatterer
- INSERM U1028, CNRS UMR5292, Lyon Neuroscience Research Center, Neuro-oncology & Neuro-inflammation Team, University of Lyon 1, Lyon F-69000, France
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Scales TM, Derkinderen P, Leung KY, Byers HL, Ward MA, Price C, Bird IN, Perera T, Kellie S, Williamson R, Anderton BH, Reynolds CH. Tyrosine phosphorylation of tau by the SRC family kinases lck and fyn. Mol Neurodegener 2011; 6:12. [PMID: 21269457 PMCID: PMC3037338 DOI: 10.1186/1750-1326-6-12] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2010] [Accepted: 01/26/2011] [Indexed: 11/10/2022] Open
Abstract
Background Tau protein is the principal component of the neurofibrillary tangles found in Alzheimer's disease, where it is hyperphosphorylated on serine and threonine residues, and recently phosphotyrosine has been demonstrated. The Src-family kinase Fyn has been linked circumstantially to the pathology of Alzheimer's disease, and shown to phosphorylate Tyr18. Recently another Src-family kinase, Lck, has been identified as a genetic risk factor for this disease. Results In this study we show that Lck is a tau kinase. In vitro, comparison of Lck and Fyn showed that while both kinases phosphorylated Tyr18 preferentially, Lck phosphorylated other tyrosines somewhat better than Fyn. In co-transfected COS-7 cells, mutating any one of the five tyrosines in tau to phenylalanine reduced the apparent level of tau tyrosine phosphorylation to 25-40% of that given by wild-type tau. Consistent with this, tau mutants with only one remaining tyrosine gave poor phosphorylation; however, Tyr18 was phosphorylated better than the others. Conclusions Fyn and Lck have subtle differences in their properties as tau kinases, and the phosphorylation of tau is one mechanism by which the genetic risk associated with Lck might be expressed pathogenically.
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Affiliation(s)
- Timothy Me Scales
- MRC Centre for Neurodegeneration Research, Department of Neuroscience, Institute of Psychiatry, King's College London, De Crespigny Park, Denmark Hill, London, SE5 8AF, UK.
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Bhaskar K, Hobbs GA, Yen SH, Lee G. Tyrosine phosphorylation of tau accompanies disease progression in transgenic mouse models of tauopathy. Neuropathol Appl Neurobiol 2011; 36:462-77. [PMID: 20609109 DOI: 10.1111/j.1365-2990.2010.01103.x] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
AIM Tau protein is a prominent component of paired helical filaments in Alzheimer's disease (AD) and other tauopathies. While the abnormal phosphorylation of tau on serine and threonine has been well established in the disease process, its phosphorylation on tyrosine has only recently been described. We previously showed that the Src family non-receptor tyrosine kinases (SFKs) Fyn and Src phosphorylate tau on Tyr18 and that phospho-Tyr18-tau was present in AD brain. In this study, we have investigated the appearance of phospho-Tyr18-tau, activated SFK and proliferating cell nuclear antigen (PCNA) during disease progression in a mouse model of human tauopathy. METHODS We have used JNPL3, which expresses human tau with P301L mutation, and antibodies specific for phospho-Tyr18-tau (9G3), ser/thr phosphorylated tau (AT8), activated SFK and PCNA. Antibody staining was viewed by either epifluorescence or confocal microscopy. RESULTS Phospho-Tyr18-tau appeared concurrently with AT8-reactive tau as early as 4 months in JNPL3. Some 9G3-positive cells also contained activated SFKs and PCNA. We also investigated the triple transgenic mouse model of AD and found that unlike the JNPL3 model, the appearance of 9G3 reactivity did not coincide with AT8 in the hippocampus, suggesting that the presence of APP/presenilin influences tau phosphorylation. Also, Thioflavin S-positive plaques were 9G3-negative, suggesting that phospho-Tyr18-tau is absent from the dystrophic neurites of the mouse triple transgenic brain. CONCLUSIONS Our results provide evidence for the association of tyrosine-phosphorylated tau with mechanisms of neuropathogenesis and indicate that SFK activation and cell cycle activation are also involved in JNPL3.
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Affiliation(s)
- K Bhaskar
- Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA
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Motoi Y, Sahara N, Kambe T, Hattori N. Tau and neurodegenerative disorders. Biomol Concepts 2010; 1:131-45. [DOI: 10.1515/bmc.2010.017] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
AbstractThe mechanisms that render tau a toxic agent are still unclear, although increasing evidence supports the assertion that alterations of tau can directly cause neuronal degeneration. In addition, it is unclear whether neurodegeneration in various tauopathies occurs via a common mechanism or that specific differences exist. The aim of this review is to provide an overview of tauopathies from bench to bedside. The review begins with clinicopathological findings of familial and sporadic tauopathies. It includes a discussion of the similarities and differences between these two conditions. The second part concentrates on biochemical alterations of tau such as phosphorylation, truncation and acetylation. Although pathological phosphorylation of tau has been studied for many years, recently researchers have focused on the physiological role of tau during development. Finally, the review contains a summary of the significance of tauopathy model mice for research on neurofibrillary tangles, axonopathies, and synaptic alteration.
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Affiliation(s)
- Yumiko Motoi
- 1Department of Neurology, Juntendo University School of Medicine, 2-1-1, Hongo Bunkyo-ku Tokyo 113-8421, Tokyo, Japan
| | - Naruhiko Sahara
- 2Department of Neuroscience, Mayo Clinic, Jacksonville, FL 32224, USA
| | - Taiki Kambe
- 1Department of Neurology, Juntendo University School of Medicine, 2-1-1, Hongo Bunkyo-ku Tokyo 113-8421, Tokyo, Japan
| | - Nobutaka Hattori
- 1Department of Neurology, Juntendo University School of Medicine, 2-1-1, Hongo Bunkyo-ku Tokyo 113-8421, Tokyo, Japan
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Tremblay MA, Acker CM, Davies P. Tau phosphorylated at tyrosine 394 is found in Alzheimer's disease tangles and can be a product of the Abl-related kinase, Arg. J Alzheimers Dis 2010; 19:721-33. [PMID: 20110615 DOI: 10.3233/jad-2010-1271] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Tau is a microtubule-associated protein and a main component of neurofibrillary tangles, one of the pathologic hallmarks of Alzheimer's disease. The paired helical filaments (PHF) that comprise neurofibrillary tangles contain an abnormally hyperphosphorylated form of tau. Historically, most of the tau phosphorylation sites that have been characterized are serine and threonine residues. Recent reports state that tau can be phosphorylated at tyrosine residues by kinases including Fyn, Syk, and c-abl (Abl). Proteomic analyses show that tau phosphorylated at tyrosine 394 (Y394) exists within PHF samples taken from Alzheimer's disease brains. This study also confirms phosphorylation of Y394 as an Alzheimer's disease-specific event by immunohistochemistry. To date, only Abl is known to phosphorylate this particular site on tau. We report, for the first time, that Arg, the other member of the Abl family of tyrosine kinases, also phosphorylates tau at Y394 in a manner independent of Abl activity. Given the reported role of Arg in oxidative stress response and neural development, the ability to phosphorylate tau at Y394 implicates Arg as a potential player in the pathogenesis of Alzheimer's disease and other tauopathies.
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Affiliation(s)
- Matthew A Tremblay
- Department of Pathology, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
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Rouer E. [Neuronal isoforms of Src, Fyn and Lck tyrosine kinases: A specific role for p56lckN in neuron protection]. C R Biol 2010; 333:1-10. [PMID: 20176329 DOI: 10.1016/j.crvi.2009.10.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2009] [Revised: 10/14/2009] [Accepted: 10/15/2009] [Indexed: 12/06/2022]
Abstract
The two main tyrosine kinases (TK) in the brain are p60Src and p59Fyn, expressed as specific isoforms (p60SrcNI, p60SrcNI+NII and p59fynB). They play a pivotal role in some major processes such as neuronal growth and myelinisation. Another member of this TK family was then reported in brain, the p56lck. Its name Lck (lymphocyte cell kinase) indicates its cellular specificity observed initially, so its presence in the brain was intriguing. But no further studies were performed to understand its role in brain until recent clinical studies on Alzheimer patients' brains. One study reveals a decreased p56lck level in the brains of these patients while another study shows an association between one peculiar SNP (single nucleotide polymorphism) of the lck gene and some cases of the disease. These new data prompt us to reinvestigate the original biochemical data and to confront them with the present knowledge. This analysis suggests some hypothesis concerning both the Lck protein expressed in the brain (rather an isoform than the lymphocyte protein itself) and its role (to maintain the neuronal survival presumably by protecting them from inflammation, the main pathway that leads to neuron degeneracy).
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Affiliation(s)
- Evelyne Rouer
- Inserm U-839, institut du Fer-à-Moulin, 37, rue du Fer-à-Moulin, 75005 Paris, France.
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Gendron TF, Petrucelli L. The role of tau in neurodegeneration. Mol Neurodegener 2009; 4:13. [PMID: 19284597 PMCID: PMC2663562 DOI: 10.1186/1750-1326-4-13] [Citation(s) in RCA: 312] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2009] [Accepted: 03/11/2009] [Indexed: 01/31/2023] Open
Abstract
Since the identification of tau as the main component of neurofibrillary tangles in Alzheimer's disease and related tauopathies, and the discovery that mutations in the tau gene cause frontotemporal dementia, much effort has been directed towards determining how the aggregation of tau into fibrillar inclusions causes neuronal death. As evidence emerges that tau-mediated neuronal death can occur even in the absence of tangle formation, a growing number of studies are focusing on understanding how abnormalities in tau (e.g. aberrant phosphorylation, glycosylation or truncation) confer toxicity. Though data obtained from experimental models of tauopathies strongly support the involvement of pathologically modified tau and tau aggregates in neurodegeneration, the exact neurotoxic species remain unclear, as do the mechanism(s) by which they cause neuronal death. Nonetheless, it is believed that tau-mediated neurodegeneration is likely to result from a combination of toxic gains of function as well as from the loss of normal tau function. To truly appreciate the detrimental consequences of aberrant tau function, a better understanding of all functions carried out by tau, including but not limited to the role of tau in microtubule assembly and stabilization, is required. This review will summarize what is currently known regarding the involvement of tau in the initiation and development of neurodegeneration in tauopathies, and will also highlight some of the remaining questions in need of further investigation.
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Affiliation(s)
- Tania F Gendron
- Department of Neuroscience, Mayo Clinic College of Medicine, Jacksonville, Florida, USA.
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