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Festoff BW, Citron BA. Thrombin and the Coag-Inflammatory Nexus in Neurotrauma, ALS, and Other Neurodegenerative Disorders. Front Neurol 2019; 10:59. [PMID: 30804878 PMCID: PMC6371052 DOI: 10.3389/fneur.2019.00059] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Accepted: 01/17/2019] [Indexed: 12/15/2022] Open
Abstract
This review details our current understanding of thrombin signaling in neurodegeneration, with a focus on amyotrophic lateral sclerosis (ALS, Lou Gehrig's disease) as well as future directions to be pursued. The key factors are multifunctional and involved in regulatory pathways, namely innate immune and the coagulation cascade activation, that are essential for normal nervous system function and health. These two major host defense systems have a long history in evolution and include elements and regulators of the coagulation pathway that have significant impacts on both the peripheral and central nervous system in health and disease. The clotting cascade responds to a variety of insults to the CNS including injury and infection. The blood brain barrier is affected by these responses and its compromise also contributes to these detrimental effects. Important molecules in signaling that contribute to or protect against neurodegeneration include thrombin, thrombomodulin (TM), protease activated receptor 1 (PAR1), damage associated molecular patterns (DAMPs), such as high mobility group box protein 1 (HMGB1) and those released from mitochondria (mtDAMPs). Each of these molecules are entangled in choices dependent upon specific signaling pathways in play. For example, the particular cleavage of PAR1 by thrombin vs. activated protein C (APC) will have downstream effects through coupled factors to result in toxicity or neuroprotection. Furthermore, numerous interactions influence these choices such as the interplay between HMGB1, thrombin, and TM. Our hope is that improved understanding of the ways that components of the coagulation cascade affect innate immune inflammatory responses and influence the course of neurodegeneration, especially after injury, will lead to effective therapeutic approaches for ALS, traumatic brain injury, and other neurodegenerative disorders.
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Affiliation(s)
- Barry W Festoff
- pHLOGISTIX LLC, Fairway, KS, United States.,Department of Neurology, University of Kansas Medical Center, Kansas City, KS, United States
| | - Bruce A Citron
- Laboratory of Molecular Biology Research & Development, VA New Jersey Health Care System, East Orange, NJ, United States.,Department of Pharmacology, Physiology & Neuroscience, Rutgers New Jersey Medical School, Newark, NJ, United States
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2
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Oono M, Okado-Matsumoto A, Shodai A, Ido A, Ohta Y, Abe K, Ayaki T, Ito H, Takahashi R, Taniguchi N, Urushitani M. Transglutaminase 2 accelerates neuroinflammation in amyotrophic lateral sclerosis through interaction with misfolded superoxide dismutase 1. J Neurochem 2013; 128:403-18. [DOI: 10.1111/jnc.12441] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2013] [Revised: 08/09/2013] [Accepted: 08/27/2013] [Indexed: 11/28/2022]
Affiliation(s)
- Miki Oono
- Molecular Neuroscience Research Center; Shiga University of Medical Science; Otsu Shiga Japan
- Department of Neurology; Kyoto University Graduate school of Medicine; Kyoto Japan
| | | | - Akemi Shodai
- Molecular Neuroscience Research Center; Shiga University of Medical Science; Otsu Shiga Japan
| | - Akemi Ido
- Molecular Neuroscience Research Center; Shiga University of Medical Science; Otsu Shiga Japan
| | - Yasuyuki Ohta
- Department of Neurology; Okayama University Graduate School of Medicine; Dentistry and Pharmaceutical Sciences; Okayama Japan
| | - Koji Abe
- Department of Neurology; Okayama University Graduate School of Medicine; Dentistry and Pharmaceutical Sciences; Okayama Japan
| | - Takashi Ayaki
- Department of Neurology; Kyoto University Graduate school of Medicine; Kyoto Japan
| | - Hidefumi Ito
- Department of Neurology; Wakayama Medical University; Graduate School of Medicine; Wakayama Japan
| | - Ryosuke Takahashi
- Department of Neurology; Kyoto University Graduate school of Medicine; Kyoto Japan
| | | | - Makoto Urushitani
- Molecular Neuroscience Research Center; Shiga University of Medical Science; Otsu Shiga Japan
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3
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Tay WM, Bryant JG, Martin PK, Nix AJ, Cusack BM, Rosenberry TL. A mass spectrometric approach for characterization of amyloid-β aggregates and identification of their post-translational modifications. Biochemistry 2012; 51:3759-66. [PMID: 22506642 DOI: 10.1021/bi300316d] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Endogenous amyloid-β (Aβ) oligomeric aggregates have been proposed as toxic agents in Alzheimer's disease (AD). Knowledge of their structures not only may provide insight into the basis of their neurotoxicities but also may reveal new targets for therapeutic drugs and diagnostic tools. However, the low levels of these Aβ oligomers have impeded structural characterization. Evidence suggests that the endogenous oligomers are covalently modified in vivo. In this report, we demonstrate an established mass spectrometry (MS) methodology called precursor ion mapping (PIM) that potentially may be applied to endogenous oligomer characterization. First, we illustrate the use of this PIM technique with a synthetic Aβ(1-40) monomer sample that had been cross-linked with transglutaminase (TGase) and digested with pepsin. From PIM analysis of an Aβ(4-13) MS/MS fragment, precursor ions were identified that corresponded to peptic fragments of three TGase cross-linked species: Aβ(4-19)--(4-19), Aβ(4-19)--(20-34), and Aβ(1-19)--(20-34). Next, we demonstrate the applicability of the PIM technique to an endogenous Aβ sample that had been purified and concentrated by immunoaffinity chromatography. Without pepsin digestion, we successfully identified the full length and C-terminally truncated monomeric Aβ species 1-35 to 1-42, along with select methionine-oxidized counterparts. Because PIM focuses only on a subpopulation of ions, namely the related precursor ions, the resulting spectra are of increased specificity and sensitivity. Therefore, this methodology shows great promise for structural analysis and identification of post-translational modification(s) in endogenous Aβ oligomers.
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Affiliation(s)
- William M Tay
- Department of Neuroscience, Mayo Clinic, 4500 San Pablo Road, Jacksonville, Florida 32224, USA
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Abstract
Aggregated a-synuclein is the major component of inclusions in Parkinson's disease and other synucleinopathy brains indicating that a-syn aggregation is associated with the pathogenesis of neurodegenerative disorders. Although the mechanisms underlying a-syn aggregation and toxicity are not fully elucidated, it is clear that a-syn undergoes post-translational modifications and interacts with numerous proteins and other macromolecules, metals, hormones, neurotransmitters, drugs and poisons that can all modulate its aggregation propensity. The current and most recent findings regarding the factors modulating a-syn aggregation process are discussed in detail.
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5
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Transglutaminase 2: biology, relevance to neurodegenerative diseases and therapeutic implications. Pharmacol Ther 2011; 133:392-410. [PMID: 22212614 DOI: 10.1016/j.pharmthera.2011.12.003] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2011] [Accepted: 12/06/2011] [Indexed: 12/24/2022]
Abstract
Neurodegenerative disorders are characterized by progressive neuronal loss and the aggregation of disease-specific pathogenic proteins in hallmark neuropathologic lesions. Many of these proteins, including amyloid Αβ, tau, α-synuclein and huntingtin, are cross-linked by the enzymatic activity of transglutaminase 2 (TG2). Additionally, the expression and activity of TG2 is increased in affected brain regions in these disorders. These observations along with experimental evidence in cellular and mouse models suggest that TG2 can contribute to the abnormal aggregation of disease causing proteins and consequently to neuronal damage. This accumulating evidence has provided the impetus to develop inhibitors of TG2 as possible neuroprotective agents. However, TG2 has other enzymatic activities in addition to its cross-linking function and can modulate multiple cellular processes including apoptosis, autophagy, energy production, synaptic function, signal transduction and transcription regulation. These diverse properties must be taken into consideration in designing TG2 inhibitors. In this review, we discuss the biochemistry of TG2, its various physiologic functions and our current understanding about its role in degenerative diseases of the brain. We also describe the different approaches to designing TG2 inhibitors that could be developed as potential disease-modifying therapies.
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Hoffner G, Vanhoutteghem A, André W, Djian P. Transglutaminase in epidermis and neurological disease or what makes a good cross-linking substrate. ADVANCES IN ENZYMOLOGY AND RELATED AREAS OF MOLECULAR BIOLOGY 2011; 78:97-160. [PMID: 22220473 DOI: 10.1002/9781118105771.ch3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Guylaine Hoffner
- Unité Propre de Recherche 2228 du Centre National de la Recherche Scientifique, Régulation de la Transcription et Maladies Génétiques, Université Paris Descartes, Paris, France
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Nemes Z. Effects and Analysis of Transglutamination on Protein Aggregation and Clearance in Neurodegenerative Diseases. ADVANCES IN ENZYMOLOGY - AND RELATED AREAS OF MOLECULAR BIOLOGY 2011; 78:347-83. [DOI: 10.1002/9781118105771.ch8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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8
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Evidences for a role of protein cross-links in transglutaminase-related disease. Amino Acids 2011; 42:975-86. [DOI: 10.1007/s00726-011-1011-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2011] [Accepted: 05/24/2011] [Indexed: 01/13/2023]
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Fodero-Tavoletti MT, Okamura N, Furumoto S, Mulligan RS, Connor AR, McLean CA, Cao D, Rigopoulos A, Cartwright GA, O'Keefe G, Gong S, Adlard PA, Barnham KJ, Rowe CC, Masters CL, Kudo Y, Cappai R, Yanai K, Villemagne VL. 18F-THK523: a novel in vivo tau imaging ligand for Alzheimer's disease. Brain 2011; 134:1089-100. [PMID: 21436112 DOI: 10.1093/brain/awr038] [Citation(s) in RCA: 244] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
While considerable effort has focused on developing positron emission tomography β-amyloid imaging radiotracers for the early diagnosis of Alzheimer's disease, no radiotracer is available for the non-invasive quantification of tau. In this study, we detail the characterization of (18)F-THK523 as a novel tau imaging radiotracer. In vitro binding studies demonstrated that (18)F-THK523 binds with higher affinity to a greater number of binding sites on recombinant tau (K18Δ280K) compared with β-amyloid(1-42) fibrils. Autoradiographic and histofluorescence analysis of human hippocampal serial sections with Alzheimer's disease exhibited positive THK523 binding that co-localized with immunoreactive tau pathology, but failed to highlight β-amyloid plaques. Micro-positron emission tomography analysis demonstrated significantly higher retention of (18)F-THK523 (48%; P < 0.007) in tau transgenic mice brains compared with their wild-type littermates or APP/PS1 mice. The preclinical examination of THK523 has demonstrated its high affinity and selectivity for tau pathology both in vitro and in vivo, indicating that (18)F-THK523 fulfils ligand criteria for human imaging trials.
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Potent transglutaminase inhibitors, dithio β-aminoethyl ketones. Bioorg Med Chem Lett 2011; 21:377-9. [DOI: 10.1016/j.bmcl.2010.10.136] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2010] [Revised: 10/26/2010] [Accepted: 10/28/2010] [Indexed: 12/21/2022]
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11
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Fornelli L, Schmid AW, Grasso L, Vogel H, Tsybin YO. Deamidation and transamidation of substance P by tissue transglutaminase revealed by electron-capture dissociation fourier transform mass spectrometry. Chemistry 2010; 17:486-97. [PMID: 21207565 DOI: 10.1002/chem.201002483] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2010] [Indexed: 11/07/2022]
Abstract
Tissue transglutaminase (tTGase) catalyzes both deamidation and transamidation of peptides and proteins by using a peptidyl glutamine as primary substrate. A precise consensus sequence for the enzyme is unknown and the ratio between deamidated and transamidated (or cross-linked) reaction products is highly substrate-dependent. Due to its overlapping body distribution with tTGase and ease of manipulation with tandem mass spectrometry, we used the neuropeptide substance P as a model to investigate the associated enzymatic kinetics and reaction products. Online liquid-chromatography Fourier-transform ion-cyclotron-resonance mass spectrometry (FT-ICR MS) combined with electron-capture dissociation (ECD) was employed to study the tTGase-induced modifications of substance P. A particular strength of ECD for peptide-enzyme reaction product monitoring is its ability to distinguish isomeric amino acids, for example, Glu and iso-Glu, by signature product ions. Our studies show that the primary reaction observed is deamidation, with the two consecutive glutamine residues converted sequentially into glutamate: first Gln(5) , and subsequently Gln(6) . We then applied ECD FT-ICR MS to identify the transamidation site on an enzymatically cross-linked peptide, which turned out to correspond to Gln(5) . Three populations of substance-P dimers were detected that differed by the number of deamidated Gln residues. The higher reactivity of Gln(5) over Gln(6) was further confirmed by cross-linking SP with monodansylcadaverine (MDC). Overall, our approach described herein is of a general importance for mapping both enzymatically induced post-translational protein modifications and cross-linking. Finally, in vitro Ca-signaling assays revealed that the main tTGase reaction product, the singly deamidated SP (RPKPEQFFGLM-NH(2) ), has increased agonist potency towards its natural receptor, thus confirming the biologically relevant role of deamidation.
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Affiliation(s)
- Luca Fornelli
- Biomolecular Mass Spectrometry Laboratory, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
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12
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Davies JE, Rose C, Sarkar S, Rubinsztein DC. Cystamine suppresses polyalanine toxicity in a mouse model of oculopharyngeal muscular dystrophy. Sci Transl Med 2010; 2:34ra40. [PMID: 20519718 DOI: 10.1126/scitranslmed.3000723] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Oculopharyngeal muscular dystrophy (OPMD) is caused by a trinucleotide repeat expansion mutation in the coding region of the gene encoding PABPN1 (polyadenylate-binding protein nuclear 1). Mutant PABPN1 with a polyalanine tract expansion forms aggregates within the nuclei of skeletal muscle fibers. There is currently no effective treatment. We have developed cell and mouse models of OPMD and have identified the aggregation of mutant PABPN1 and apoptosis as therapeutic targets. Here, we show that transglutaminase activity is increased in muscle from OPMD model mice. Elevated transglutaminase 2 expression enhances, whereas TG2 knockdown suppresses, the toxicity and aggregation of mutant PABPN1 in cells. Cystamine protects against the toxicity of mutant PABPN1 and exerts its effect via the inhibition of transglutaminase 2, as cystamine treatment is unable to further reduce the protective effect of transglutaminase 2 knockdown on mutant PABPN1 toxicity in cells. Cystamine also reduces the aggregation and toxicity of mutant PABPN1 in human cells. In a mouse model of OPMD, cystamine treatment reduced the elevated transglutaminase activity, attenuated muscle weakness, reduced aggregate load, and decreased apoptotic markers in muscle. Therefore, inhibitors of transglutaminase 2 should be considered as possible therapeutics for OPMD.
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Affiliation(s)
- Janet E Davies
- Department of Medical Genetics, University of Cambridge, Cambridge Institute for Medical Research, Addenbrooke's Hospital, Cambridge, UK
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13
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Jeitner TM, Pinto JT, Krasnikov BF, Horswill M, Cooper AJL. Transglutaminases and neurodegeneration. J Neurochem 2009; 109 Suppl 1:160-6. [PMID: 19393023 DOI: 10.1111/j.1471-4159.2009.05843.x] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Transglutaminases (TGs) are Ca2+-dependent enzymes that catalyze a variety of modifications of glutaminyl (Q) residues. In the brain, these modifications include the covalent attachment of a number of amine-bearing compounds, including lysyl (K) residues and polyamines, which serve to either regulate enzyme activity or attach the TG substrates to biological matrices. Aberrant TG activity is thought to contribute to Alzheimer disease, Parkinson disease, Huntington disease, and supranuclear palsy. Strategies designed to interfere with TG activity have some benefit in animal models of Huntington and Parkinson diseases. The following review summarizes the involvement of TGs in neurodegenerative diseases and discusses the possible use of selective inhibitors as therapeutic agents in these diseases.
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Schmid AW, Chiappe D, Pignat V, Grimminger V, Hang I, Moniatte M, Lashuel HA. Dissecting the mechanisms of tissue transglutaminase-induced cross-linking of alpha-synuclein: implications for the pathogenesis of Parkinson disease. J Biol Chem 2009; 284:13128-42. [PMID: 19164286 DOI: 10.1074/jbc.m809067200] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Tissue transglutaminase (tTG) has been implicated in the pathogenesis of Parkinson disease (PD). However, exactly how tTG modulates the structural and functional properties of alpha-synuclein (alpha-syn) and contributes to the pathogenesis of PD remains unknown. Using site-directed mutagenesis combined with detailed biophysical and mass spectrometry analyses, we sought to identify the exact residues involved in tTG-catalyzed cross-linking of wild-type alpha-syn and alpha-syn mutants associated with PD. To better understand the structural consequences of each cross-linking reaction, we determined the effect of tTG-catalyzed cross-linking on the oligomerization, fibrillization, and membrane binding of alpha-syn in vitro. Our findings show that tTG-catalyzed cross-linking of monomeric alpha-syn involves multiple cross-links (specifically 2-3). We subjected tTG-catalyzed cross-linked monomeric alpha-syn composed of either wild-type or Gln --> Asn mutants to sequential proteolysis by multiple enzymes and peptide mapping by mass spectrometry. Using this approach, we identified the glutamine and lysine residues involved in tTG-catalyzed intramolecular cross-linking of alpha-syn. These studies demonstrate for the first time that Gln(79) and Gln(109) serve as the primary tTG reactive sites. Mutating both residues to asparagine abolishes tTG-catalyzed cross-linking of alpha-syn and tTG-induced inhibition of alpha-syn fibrillization in vitro. To further elucidate the sequence and structural basis underlying these effects, we identified the lysine residues that form isopeptide bonds with Gln(79) and Gln(109). This study provides mechanistic insight into the sequence and structural basis of the inhibitory effects of tTG on alpha-syn fibrillogenesis in vivo, and it sheds light on the potential role of tTG cross-linking on modulating the physiological and pathogenic properties of alpha-syn.
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Affiliation(s)
- Adrien W Schmid
- Laboratory of Molecular Neurobiology and Neuroproteomics, Brain Mind Institute, School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
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Site-specific modification and PEGylation of pharmaceutical proteins mediated by transglutaminase. Adv Drug Deliv Rev 2008; 60:13-28. [PMID: 17916398 DOI: 10.1016/j.addr.2007.06.015] [Citation(s) in RCA: 205] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2007] [Accepted: 06/26/2007] [Indexed: 11/23/2022]
Abstract
Transglutaminase (TGase, E.C. 2.3.2.13) catalyzes acyl transfer reactions between the gamma-carboxamide groups of protein-bound glutamine (Gln) residues, which serve as acyl donors, and primary amines, resulting in the formation of new gamma-amides of glutamic acid and ammonia. By using an amino-derivative of poly(ethylene glycol) (PEG-NH(2)) as substrate for the enzymatic reaction with TGase it is possible to covalently bind the PEG polymer to proteins of pharmaceutical interest. In our laboratory, we have conducted experiments aimed to modify proteins of known structure using TGase and, surprisingly, we were able to obtain site-specific modification or PEGylation of protein-bound Gln residue(s) in the protein substrates. For example, in apomyoglobin (apoMb, myoglobin devoid of heme) only Gln91 was modified and in human growth hormone only Gln40 and Gln141, despite these proteins having many more Gln residues. Moreover, we noticed that these proteins suffered highly selective limited proteolysis phenomena at the same chain regions being attacked by TGase. We have analysed also the results of other published experiments of TGase-mediated modification or PEGylation of several proteins in terms of protein structure and dynamics, among them alpha-lactalbumin and interleukin-2, as well as disordered proteins. A noteworthy correlation was observed between chain regions of high temperature factor (B-factor) determined crystallographically and sites of TGase attack and limited proteolysis, thus emphasizing the role of chain mobility or local unfolding in dictating site-specific enzymatic modification. We propose that enhanced chain flexibility favors limited enzymatic reactions on polypeptide substrates by TGases and proteases, as well as by other enzymes involved in a number of site-specific post-translational modifications of proteins, such as phosphorylation and glycosylation. Therefore, it is possible to predict the site(s) of TGase-mediated modification and PEGylation of a therapeutic protein on the basis of its structure and dynamics and, consequently, the likely effects of modifications on the functional properties of the protein.
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Naylor R, Hill AF, Barnham KJ. Neurotoxicity in Alzheimer’s disease: is covalently crosslinked Aβ responsible? EUROPEAN BIOPHYSICS JOURNAL: EBJ 2007; 37:265-8. [DOI: 10.1007/s00249-007-0243-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2007] [Revised: 11/18/2007] [Accepted: 11/20/2007] [Indexed: 11/28/2022]
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Abstract
Aggregation of alpha-synuclein, an abundant and conserved pre-synaptic brain protein, is implicated as a critical factor in several neurodegenerative diseases. These diseases, known as synucleinopathies, include Parkinson's disease, dementia with Lewy bodies (LBs), diffuse LB disease, the LB variant of Alzheimer's disease, multiple system atrophy, and neurodegeneration with brain iron accumulation type I. Although the precise nature of in vivoalpha-synuclein function remains elusive, considerable knowledge has been accumulated about its structural properties and conformational behavior. alpha-Synuclein is a typical natively unfolded protein. It is characterized by the lack of rigid, well-defined, 3-D structure and possesses remarkable conformational plasticity. The structure of this protein depends dramatically on its environment and it accommodates a number of unrelated conformations. This paper provides an overview of the biochemistry, biophysics, and neuropathology of alpha-synuclein aggregation.
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Affiliation(s)
- Vladimir N Uversky
- Department of Biochemistry and Molecular Biology, Center for Computational Biology and Bioinformatics, Indiana University School of Medicine, Indianapolis, Indiana, USA.
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Prodan CI, Szasz R, Vincent AS, Ross ED, Dale GL. Coated-platelets retain amyloid precursor protein on their surface. Platelets 2006; 17:56-60. [PMID: 16308188 DOI: 10.1080/09537100500181913] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Coated-Platelets are a subset of platelets produced by dual-agonist activation with collagen plus thrombin and are characterized by strong retention of several procoagulant, alpha-granule proteins on the cell surface. In this report we demonstrate that coated-platelets also retain full-length amyloid precursor protein (APP) on their surface in contrast to the cleavage of APP in platelets activated with a single agonist. In addition, western blot analysis indicated that APP is derivatized during coated-platelet synthesis. We subsequently measured coated-platelet production in patients with Alzheimer's disease (AD). Twenty-two AD patients showed a wide distribution of coated-platelet values; however the least impaired AD patients produced coated-platelets at a level significantly above that of aged controls (41.0 +/- 9.9 vs. 28.7 +/- 11.4%; mean +/- 1SD; p = 0.017). These findings suggest that coated-platelets may be a model of aberrant APP processing in early AD patients.
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Affiliation(s)
- Calin I Prodan
- Department of Neurology, University of Oklahoma Health Sciences Center, klahoma City, Oklahoma 73104, USA
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Citron BA, Zoloty JE, Suo Z, Festoff BW. Tissue transglutaminase during mouse central nervous system development: lack of alternative RNA processing and implications for its role(s) in murine models of neurotrauma and neurodegeneration. ACTA ACUST UNITED AC 2005; 135:122-33. [PMID: 15857675 DOI: 10.1016/j.molbrainres.2004.12.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2004] [Revised: 11/17/2004] [Accepted: 12/05/2004] [Indexed: 11/28/2022]
Abstract
Tissue transglutaminase (tTG) is a member of a multigene family principally involved in catalyzing the formation of protein cross-links. Unlike other members of the transglutaminase family, tTG is multifunctional since it also serves as a guanosine triphosphate (GTP) binding protein (Galpha(h)) and participates in cell adhesion. Different isoforms of tTG can be produced by proteolysis or alternative splicing. We find that tTG mRNA is expressed at low levels in the mouse CNS relative to other tissues, and at lower levels in the CNS of mouse in comparison to that of human or rat. tTG mRNA levels are higher in the heart compared to the CNS, for example, and much higher in the liver. Within the CNS, tTG message is lowest in the adult cerebellum and thalamus and highest in the frontal cortex and striatum. In the hippocampus, tTG expression is highest during embryonic development and falls off dramatically after 1 week of life. We did not find alternative splicing of the mouse tTG. At the protein level, the predominant isoform is approximately 62 kDa. In summary, tTG, an important factor in neuronal survival, is expressed at low levels in the mouse CNS and, unlike rat and human tTG, does not appear to be regulated by alternative splicing. These findings have implications for analyses of rodent tTG expression in human neurodegenerative and neurotrauma models where alternative processing may be an attractive pathogenetic mechanism. They further impact on drug discovery paradigms, where modulation of activity may have therapeutic value.
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Affiliation(s)
- Bruce A Citron
- Molecular Biology, Veterans Affairs Medical Center, 4801 Linwood Boulevard, Kansas City, MO 64128, USA
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Suh MD, Park CH, Kim SS, Kil MO, Lee GH, Johnson GVW, Chun W. Tissue transglutaminase is not involved in the aggregate formation of stably expressed α-synuclein in sh-sy5y human neuroblastoma cells. Arch Pharm Res 2004; 27:850-6. [PMID: 15460447 DOI: 10.1007/bf02980178] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Intraneuronal deposition containing alpha-synuclein is implicated in the pathogenesis of synuclein-opathies including Parkinsons disease (PD). Although it has been demonstrated that cytoplasmic inclusions of wild type alpha-synuclein are observed in the brain of PD patients and that alpha-synuclein mutations such as A30P and A53T accelerate aggregate formation, the exact mechanism by which alpha-synuclein forms insoluble aggregates is still controversial. In the present study, to understand the possible involvement of tissue transglutaminase (tTG) in aggregate formation of alpha-synuclein, SH-SY5Y cell lines stably expressing wild type or mutant (A30P or A53T) alpha-synuclein were created and aggregate formation of alpha-synuclein was observed upon activation of tTG. The data demonstrated that alpha-synuclein negligibly interacted with tTG and that activation of tTG did not result in the aggregate formation of alpha-synuclein in SH-SY5Y cells overexpressing either wild type or mutant alpha-synuclein. In addition, alpha-synuclein was not modified by activated tTG in situ. These data suggest that tTG is unlikely to be a contributing factor to the formation of aggregates of alpha-synuclein in a stable cell model.
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Affiliation(s)
- Myung-Duk Suh
- Department of Pharmacology, College of Medicine, Kangwon National University, Chunchon 200-701, Korea
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Bailey CDC, Graham RM, Nanda N, Davies PJA, Johnson GVW. Validity of mouse models for the study of tissue transglutaminase in neurodegenerative diseases. Mol Cell Neurosci 2004; 25:493-503. [PMID: 15033177 DOI: 10.1016/j.mcn.2003.11.016] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2003] [Revised: 11/24/2003] [Accepted: 11/25/2003] [Indexed: 02/06/2023] Open
Abstract
Tissue transglutaminase (tTG) is a multifunctional enzyme that catalyzes peptide cross-linking and polyamination reactions, and also is a signal-transducing GTPase. tTG protein content and enzymatic activity are upregulated in the brain in Huntington's disease and in other neurological diseases and conditions. Since mouse models are currently being used to study the role of tTG in Huntington's disease and other neurodegenerative diseases, it is critical that the level of its expression in the mouse forebrain be determined. In contrast to human forebrain where tTG is abundant, tTG can only be detected in mouse forebrain by immunoblotting a GTP-binding-enriched protein fraction. tTG mRNA content and transamidating activity are approximately 70% lower in mouse than in human forebrain. However, tTG contributes to the majority of transglutaminase activity within mouse forebrain. Thus, although tTG is expressed at lower levels in mouse compared with human forebrain, it likely plays important roles in neuronal function.
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Affiliation(s)
- Craig D C Bailey
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham, Birmingham, AL 35294-0017, USA
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22
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Junn E, Ronchetti RD, Quezado MM, Kim SY, Mouradian MM. Tissue transglutaminase-induced aggregation of alpha-synuclein: Implications for Lewy body formation in Parkinson's disease and dementia with Lewy bodies. Proc Natl Acad Sci U S A 2003; 100:2047-52. [PMID: 12576551 PMCID: PMC149956 DOI: 10.1073/pnas.0438021100] [Citation(s) in RCA: 175] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2002] [Accepted: 12/31/2002] [Indexed: 12/24/2022] Open
Abstract
Proteinaceous aggregates containing alpha-synuclein represent a feature of neurodegenerative disorders such as Parkinson's disease, dementia with Lewy bodies, and multiple system atrophy. Despite extensive research, the mechanisms underlying alpha-synuclein aggregation remain elusive. Previously, tissue transglutaminase (tTGase) was found to contribute to the generation of aggregates by cross-linking pathogenic substrate proteins in Huntington's and Alzheimer's diseases. In this article, the role of tTGase in the formation of alpha-synuclein aggregates was investigated. Purified tTGase catalyzed alpha-synuclein cross-linking, leading to the formation of high molecular weight aggregates in vitro, and overexpression of tTGase resulted in the formation of detergent-insoluble alpha-synuclein aggregates in cellular models. Immunocytochemical studies demonstrated the presence of alpha-synuclein-positive cytoplasmic inclusions in 8% of tTGase-expressing cells. The formation of these aggregates was significantly augmented by the calcium ionophore and prevented by the inhibitor cystamine. Immunohistochemical studies on postmortem brain tissue confirmed the presence of transglutaminase-catalyzed epsilon (gamma-glutamyl)lysine cross-links in the halo of Lewy bodies in Parkinson's disease and dementia with Lewy bodies, colocalizing with alpha-synuclein. These findings, taken together, suggest that tTGase activity leads to alpha-synuclein aggregation to form Lewy bodies and perhaps contributes to neurodegeneration.
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Affiliation(s)
- Eunsung Junn
- Genetic Pharmacology Unit, Experimental Therapeutics Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892-1406, USA
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Sárvári M, Fésüs L, Nemes Z. Transglutaminase-mediated crosslinking of neural proteins in Alzheimer's disease and other primary dementias. Drug Dev Res 2002. [DOI: 10.1002/ddr.10098] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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24
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Festoff BW, Suo Z, Citron BA. Plasticity and stabilization of neuromuscular and CNS synapses: interactions between thrombin protease signaling pathways and tissue transglutaminase. INTERNATIONAL REVIEW OF CYTOLOGY 2002; 211:153-77. [PMID: 11597003 DOI: 10.1016/s0074-7696(01)11018-1] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The first association of the synapse as a potential site of neurodegenerative disease burden was suggested for Alzheimer's disease (AD) almost 30 years ago. Since then protease:protease inhibitor (P:PI) systems were first linked to functional regulation of synaptogenesis and synapse withdrawal at the neuromuscular junction (NMJ) more than 20 years ago. Confirmatory evidence for the involvement of the synapse, the rate-limiting or key unit in neural function, in AD did not become clear until the beginning of the 1990s. However, over the past 15 years evidence for participation of thrombin, related serine proteases and neural PIs, homologous and even identical to those of the plasma clot cascade, has been mounting. Throughout development a balance between stabilization forces, on the one hand, and breakdown influences, on the other, becomes established at synaptic junctions, just as it does in plasma clot proteins. The formation of protease-resistant cross-links by the transglutaminase (TGase) family of enzymes may add to the stability for this balance. The TGase family includes coagulation factor XIIIA and 8 other different genes, some of which may also influence the persistence of neural connections. Synaptic location of protease-activated, G-protein-coupled receptors (PARs) for thrombin and related proteases, their serpin and Kunitz-type PIs such as protease nexin I (PNI), alpha1-antichymotrypsin (alpha-ACT), and the Kunitz protease inhibitor (KPI)-containing secreted forms of beta-amyloid protein precursor (beta-APP), along with the TGases and their putative substrates, have all been amply documented. These findings strongly add to the conclusion that these molecules participate in the eventual structural stability of synaptic connections, as they do in coagulation cascades, and focus trophic activity on surviving terminals during periods of selective contact elimination. In disease states, this imbalance is likely to be shifted in favor of destabilizing forces: increased and/or altered protease activity, enhanced PAR influence, decreased and/or altered protease inhibitor function, reduction and/or alteration in tTG expression and activity, and alteration in its substrate profile. This imbalance further initiates a cascade of events leading to inappropriate programmed cell death and may well be considered evidence of synaptic apoptosis.
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Affiliation(s)
- B W Festoff
- Neurobiology Research Laboratory, University of Kansas Medical Center, Kansas City Veterans Affairs Medical Center, Missouri 64128, USA
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25
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Abstract
Transglutaminases (TGases) are enzymes that are widely used in many biological systems for generic tissue stabilization purposes. Mutations resulting in lost activity underlie several serious disorders. In addition, new evidence documents that they may also be aberrantly activated in tissues and cells and contribute to a variety of diseases, including neurodegenerative diseases such as Alzheimer's and Huntington's diseases. In these cases, the TGases appear to be a factor in the formation of inappropriate proteinaceous aggregates that may be cytotoxic. In other cases such as celiac disease, however, TGases are involved in the generation of autoantibodies. Further, in diseases such as progressive supranuclear palsy, Huntington's, Alzheimer's and Parkinson's diseases, the aberrant activation of TGases may be caused by oxidative stress and inflammation. This review will examine the role and activation of TGases in a variety of diseases.
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Affiliation(s)
- Soo Youl Kim
- Laboratory of Skin Biology, NIAMS, NIH, MD, USA.
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26
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Citron BA, Suo Z, SantaCruz K, Davies PJA, Qin F, Festoff BW. Protein crosslinking, tissue transglutaminase, alternative splicing and neurodegeneration. Neurochem Int 2002; 40:69-78. [PMID: 11738473 DOI: 10.1016/s0197-0186(01)00062-6] [Citation(s) in RCA: 104] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Increasing interest and awareness of protein aggregation as being implicated in neurodegenerative processes has developed in recent years. One novel mechanism for this may be transglutaminase (TGase)-mediated protein crosslinking, that is involved in a variety of natural processes ranging from the stabilization of fibrin clots to production of the epidermal cell envelope and the fluid barrier of the skin. TGases are also implicated in both function and dysfunction of the central (CNS) and peripheral (PNS) nervous systems. The most ubiquitously expressed member of the TGase family, known as tissue TGase (tTG) or TG2, which, in addition to catalyzing the production of epsilon-lysine to gamma-glutaminyl isodipeptide bonds, serves a dual function as the G-protein Galpha(h) and is both expressed and active in PNS and CNS. It differs from other members of the TGase gene family in this regard and may implicate it in 'switches' from life or trophic signaling to those associated with apoptosis. In this regard, recent data indicate that one or more TGases are involved in neurodegenerative disorders such as the Qn/CAG repeat disorders, as well as Alzheimer's and Parkinson's diseases. As do many genes, particularly those highly expressed in the CNS, tTG undergoes alternative processing. Elevated expression and alternative splicing, resulting in a short (S) isoform of tTG with more active crosslinking activity, are associated with increased neuronal loss in affected regions in the demented brain. Our recent and novel data indicate that tTG mRNA, protein, and TGase activity are elevated in certain neurodegenerative diseases, and are accompanied by transcription of this S splice variant that results in unregulated crosslinking, unique to neurodegenerative disorders.
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Affiliation(s)
- Bruce A Citron
- Neurobiology Research Laboratory, Veterans Affairs Medical Center, 4801 Linwood Boulevard, Kansas City, MO 64128, USA
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Maggio N, Sellitti S, Capano CP, Papa M. Tissue-transglutaminase in rat and human brain: light and electron immunocytochemical analysis and in situ hybridization study. Brain Res Bull 2001; 56:173-82. [PMID: 11719248 DOI: 10.1016/s0361-9230(01)00649-9] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Tissue-type transglutaminases constitute a family of enzymes having a dual role. They catalyze the post-translational modification of proteins and play a role in signal transduction pathways, several isoforms have been cloned in the brain. Many in vitro experiments and post-mortem studies have claimed that the enzyme plays a central role in the development of neurodegenerative disorders, especially in CAG-triplet diseases. In the present investigation, we conducted an immunocytochemical study using two different antibodies raised against tissue-type transglutaminase. To confirm the enzyme expression, non-radioactive in situ hybridization was performed on adjacent sections. The study was completed by analyzing the ultrastructural localization of the enzyme by electron microscopy. Tissue-type transglutaminase was widely expressed in both the human and rat brain. Many positive cells exhibiting neuronal features were found in the brain and cerebellum. There was a preferential expression in elements of pyramidal and extrapyramidal pathways with less expression in the somatosensory system. The mRNA detection confirmed the distribution of the enzyme. The ultrastructural approach revealed the presence of the enzyme in all neuronal compartments. Light and electron microscopy studies showed the ubiquitous nature of the enzyme and its putative role in functional as well as putative pathological processes.
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Affiliation(s)
- N Maggio
- Istituto di Anatomia Umana, Facoltà di Medicina, Seconda Università di Napoli, Napoli, Italy
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28
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Arendt T. Alzheimer's disease as a disorder of mechanisms underlying structural brain self-organization. Neuroscience 2001; 102:723-65. [PMID: 11182240 DOI: 10.1016/s0306-4522(00)00516-9] [Citation(s) in RCA: 118] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Mental function has as its cerebral basis a specific dynamic structure. In particular, cortical and limbic areas involved in "higher brain functions" such as learning, memory, perception, self-awareness and consciousness continuously need to be self-adjusted even after development is completed. By this lifelong self-optimization process, the cognitive, behavioural and emotional reactivity of an individual is stepwise remodelled to meet the environmental demands. While the presence of rigid synaptic connections ensures the stability of the principal characteristics of function, the variable configuration of the flexible synaptic connections determines the unique, non-repeatable character of an experienced mental act. With the increasing need during evolution to organize brain structures of increasing complexity, this process of selective dynamic stabilization and destabilization of synaptic connections becomes more and more important. These mechanisms of structural stabilization and labilization underlying a lifelong synaptic remodelling according to experience, are accompanied, however, by increasing inherent possibilities of failure and may, thus, not only allow for the evolutionary acquisition of "higher brain function" but at the same time provide the basis for a variety of neuropsychiatric disorders. It is the objective of the present paper to outline the hypothesis that it might be the disturbance of structural brain self-organization which, based on both genetic and epigenetic information, constantly "creates" and "re-creates" the brain throughout life, that is the defect that underlies Alzheimer's disease (AD). This hypothesis is, in particular, based on the following lines of evidence. (1) AD is a synaptic disorder. (2) AD is associated with aberrant sprouting at both the presynaptic (axonal) and postsynaptic (dendritic) site. (3) The spatial and temporal distribution of AD pathology follows the pattern of structural neuroplasticity in adulthood, which is a developmental pattern. (4) AD pathology preferentially involves molecules critical for the regulation of modifications of synaptic connections, i.e. "morphoregulatory" molecules that are developmentally controlled, such as growth-inducing and growth-associated molecules, synaptic molecules, adhesion molecules, molecules involved in membrane turnover, cytoskeletal proteins, etc. (5) Life events that place an additional burden on the plastic capacity of the brain or that require a particularly high plastic capacity of the brain might trigger the onset of the disease or might stimulate a more rapid progression of the disease. In other words, they might increase the risk for AD in the sense that they determine when, not whether, one gets AD. (6) AD is associated with a reactivation of developmental programmes that are incompatible with a differentiated cellular background and, therefore, lead to neuronal death. From this hypothesis, it can be predicted that a therapeutic intervention into these pathogenetic mechanisms is a particular challenge as it potentially interferes with those mechanisms that at the same time provide the basis for "higher brain function".
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Affiliation(s)
- T Arendt
- Paul Flechsig Institute of Brain Research, Department of Neuroanatomy, University of Leipzig, Jahnallee 59, D-04109, Leipzig, Germany.
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29
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Mahoney SA, Wilkinson M, Smith S, Haynes LW. Stabilization of neurites in cerebellar granule cells by transglutaminase activity: identification of midkine and galectin-3 as substrates. Neuroscience 2001; 101:141-55. [PMID: 11068143 DOI: 10.1016/s0306-4522(00)00324-9] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The formation of covalent isopeptide cross-links between cell surface protein molecules by the enzyme transglutaminase C influences cell adhesion and morphology. Retinoid-inducible cross-linking activity associated with this enzyme is present in the developing rat cerebellar cortex [Perry M. J. M. et al. (1995) Neuroscience 65, 1063-1076]. A monoclonal antibody was used to localize transglutaminase C to granule neurons in the developing cerebellar cortex. The enzyme was inducible by retinoic acid both in granule neurons cultured from postnatal rat cerebellar cortex and in cells of the embryonic dorsal rhombic lip, which contain granule neuron precursors. A possible biological function for transglutaminase activity was investigated in living granule neurons, cultured on a biomatrix substratum, studied by time-lapse cinematographic analysis using the transglutaminase inactivator RS-48373-007. Inhibition of cross-linking activity did not influence the number of neurites formed by granule neurons, but caused the destabilization of neurites during the initial outgrowth period, seen as an increase in the number of growth cone retractions and the onset of premature axon collateral formation (bifurcation). Inactivation of cross-linking activity prevented the formation of fascicles between neurites only when cells were cultured on a biomatrix surface. Two glial proteins involved in cell-extracellular matrix interactions, midkine and galectin-3, were identified as putative substrates for granule neuron transglutaminase. The results suggest that covalent cross-link formation by transglutaminase C or a related enzyme generates multimeric molecular forms of glial-derived proteins, and plays a role in stabilizing newly formed neurites. A possible non-pathological role for transglutaminase in the control of axon collateral branching by developing granule neurons in the cerebellar cortex is discussed.
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Affiliation(s)
- S A Mahoney
- School of Biological Sciences, University of Bristol, Woodland Road, Bristol BS8 1UG, UK
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30
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Citron BA, SantaCruz KS, Davies PJ, Festoff BW. Intron-exon swapping of transglutaminase mRNA and neuronal Tau aggregation in Alzheimer's disease. J Biol Chem 2001; 276:3295-301. [PMID: 11013236 DOI: 10.1074/jbc.m004776200] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In order to understand the mechanism for insoluble neurotoxic protein polymerization in Alzheimer's disease (AD) brain neurons, we examined protein and gene expression for transglutaminase (TGase 2; tissue transglutaminase (tTG)) in hippocampus and isocortex. We found co-localization of tTG protein and activity with tau-positive neurofibrillary tangles, whereas mRNA and sequence analysis indicated an absolute increase in tTG synthesized. Although apoptosis in AD hippocampus is now an established mode of neuronal cell death, no definite underlying mechanism(s) is known. Since TGase-mediated protein aggregation is implicated in polyglutamine ((CAG)(n)/Q(n) expansion) disorder apoptosis, and expanded Q(n) repeats are excellent TGase substrates, a role for TGase in AD is possible. However, despite such suggestions almost 20 years ago, the molecular mechanism remained elusive. We now present one possible molecular mechanism for tTG-mediated, neurotoxic protein polymerization leading to neuronal apoptosis in AD that involves not its substrates (like Q(n) repeats) but rather the unique presence of alternative transcripts of tTG mRNA. In addition to a full-length (L) isoform in aged non-demented brains, we found a short isoform (S) lacking a binding domain in all AD brains. Our current results identify intron-exon "switching" between L and S isoforms, implicating G-protein-coupled signaling pathways associated with tTG that may help to determine the dual roles of this enzyme in neuronal life and death processes.
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Affiliation(s)
- B A Citron
- Neurobiology Research Lab, Heartland Veterans Integrated Service Network, Kansas City, Missouri 64128, USA
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31
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Citron BA, Gregory EJ, Steigerwalt DS, Qin F, Festoff BW. Regulation of the dual function tissue transglutaminase/Galpha(h) during murine neuromuscular development: gene and enzyme isoform expression. Neurochem Int 2000; 37:337-49. [PMID: 10825574 DOI: 10.1016/s0197-0186(00)00044-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Coagulation Factor XIII (F. VIII), a member of the transglutaminase (TGase) superfamily, is activated by thrombin, cross-links fibrin and stabilizes clots. Another member of this family, tissue TGase (tTG), having similar enzymatic activity, is implicated in neural development and synapse stabilization. Our previous studies indicated that synapse formation and maintenance at the neuromuscular junction (NMJ) involved components of the coagulation cascade in development. Others then showed that either F. XIII or tTG were localized at NMJs in a developmentally-regulated fashion. In the current studies, we addressed the temporal course of skeletal muscle tTG gene expression and found maximal expression at birth and continuing into the immediate postnatal period. Subcellular fractionation revealed a relatively constant particulate isoform of TGase activity which predominated in early embryonic muscle development. In contrast, cytosolic TGase specific activity became the major isoform in the postnatal period. The timing of muscle TGase activity correlated well with expression of tTG mRNA and we now present novel data of Tgm 2 gene expression for tTG in skeletal muscle. Confirming and extending the previous studies, TGase becomes localized at NMJs in the early, further ramifying in the late, neonatal period. These data suggest that the early pulse of particulate activity could coincide with the period of myoblast cell death in embryonic muscle. On the other hand, the peak cytosolic TGase activity occurs in the neonatal period, correlating temporally with muscle prothrombin expression during activity-dependent synapse elimination and possibly the source of the enzyme localized to the NMJ extracellular matrix resulting in synaptic stabilization.
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Affiliation(s)
- B A Citron
- Neurobiology Research Lab, Heartland Veterans Health Network, VA Medical Center, Kansas City, MO 64123, USA
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32
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Lesort M, Tucholski J, Miller ML, Johnson GV. Tissue transglutaminase: a possible role in neurodegenerative diseases. Prog Neurobiol 2000; 61:439-63. [PMID: 10748319 DOI: 10.1016/s0301-0082(99)00052-0] [Citation(s) in RCA: 123] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Tissue transglutaminase is a multifunctional protein that is likely to play a role in numerous processes in the nervous system. Tissue transglutaminase posttranslationally modifies proteins by transamidation of specific polypeptide bound glutamines. This action results in the formation of protein crosslinks or the incorporation of polyamines into substrate proteins, modifications that likely have significant effects on neural function. Tissue transglutaminase is a unique member of the transglutaminase family as in addition to catalyzing the calcium-dependent transamidation reaction, it also binds and hydrolyzes ATP and Guanosine 5'-triphosphate and may play a role in signal transduction. Tissue transglutaminase is a highly regulated and inducible enzyme that is developmentally regulated in the nervous system. In vitro, numerous substrates of tissue transglutaminase have been identified, and several of these proteins have been shown to be in situ substrates as well. Several specific roles for tissue transglutaminase have been described and there is evidence that tissue transglutaminase may also play a role in apoptosis. Recent findings have provided evidence that dysregulation of tissue transglutaminase may contribute to the pathology of several neurodegenerative conditions including Alzheimer's disease and Huntington's disease. In both of these diseases tissue transglutaminase and transglutaminase activity are elevated compared to age-matched controls. Further, immunohistochemical studies have demonstrated that there is an increase in tissue transglutaminase reactivity in affected neurons in both Alzheimer's and Huntington's disease. Although intriguing, many issues remain to be addressed to definitively establish a role for tissue transglutaminase in these neurodegenerative diseases.
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Affiliation(s)
- M Lesort
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham, 1720 Seventh Avenue S., SC1061, Birmingham 35294-0017, USA
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Abstract
Structural studies of Alzheimer's amyloid fibrils have revealed information about the structure at different levels. The amyloid-beta peptide has been examined in various solvents and conditions and this has led to a model by which a conformational switching occurs from alpha-helix or random coil, to a beta-sheet structure. Amyloid fibril assembly proceeds by a nucleation dependent pathway leading to elongation of the fibrils. Along this pathway small oligomeric intermediates and short fibrillar structures (protofibrils) have been observed. In cross-section the fibril appears to be composed of several subfibrils or protofilaments. Each of these protofilaments is composed of beta-sheet structure in which hydrogen bonding occurs along the length of the fibre and the beta-strands run perpendicular to the fibre axis. This hierarchy of structure is discussed in this review.
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Affiliation(s)
- L C Serpell
- Neurobiology Division, MRC Centre, Cambridge, UK.
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Lynn DG, Meredith SC. Review: model peptides and the physicochemical approach to beta-amyloids. J Struct Biol 2000; 130:153-73. [PMID: 10940223 DOI: 10.1006/jsbi.2000.4287] [Citation(s) in RCA: 93] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
beta-Amyloid peptides are the main protein components of neuritic plaques and may be important in the pathogenesis of Alzheimer's Disease. The determination of the structure of beta-amyloid fibrils poses a challenge because of the limited solubility of beta-amyloid peptides and the noncrystalline nature of fibrils formed from these peptides. In this paper, we describe several physicochemical approaches which have been used to examine fibrils and the fibrillogenesis of peptide models of beta-amyloid. Recent advances in solid state NMR, such as the DRAWS pulse sequence, have made this approach a particularly attractive one for peptides such as beta-amyloid, which are not yet amenable to high-resolution solution phase NMR and crystallography. The application of solid state NMR techniques has yielded information on a model peptide comprising residues 10-35 of human beta-amyloid and indicates that in fibrils, this peptide assumes a parallel beta-strand conformation, with all residues in exact register. In addition, we discuss the use of block copolymers of Abeta peptides and polyethylene glycol as probes for the pathways of fibrillogenesis. These methods can be combined with other new methods, such as high-resolution synchrotron X-ray diffraction and small angle neutron and X-ray scattering, to yield structural data of relevance not only to disease, but to the broader question of protein folding and self-assembly.
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Affiliation(s)
- D G Lynn
- Department of Chemistry, The University of Chicago, 5735 S. Ellis Avenue, Chicago, Illinois, 60637-1403, USA
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35
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Choi YC, Park GT, Kim TS, Sunwoo IN, Steinert PM, Kim SY. Sporadic inclusion body myositis correlates with increased expression and cross-linking by transglutaminases 1 and 2. J Biol Chem 2000; 275:8703-10. [PMID: 10722712 DOI: 10.1074/jbc.275.12.8703] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Sporadic inclusion body myositis (SIBM) is characterized by vacuolar degeneration of muscle fibers and intrafiber clusters of paired helical filaments with abnormal amyloid deposition. Because of their potential involvement in other degenerative disorders, we have examined the expression of transglutaminases (TGases) in normal and SIBM tissues. We report that at least two different enzymes, the ubiquitous TGase 2 as well as the TGase 1 enzyme, are present in muscle tissues. However, in comparison with normal tissue, the expression of TGases 1 and 2 was increased 2.5- and 4-fold in SIBM, accompanied by about a 20-fold higher total TGase activity. By immunohistochemical staining, in normal muscle, TGase 2 expression was restricted to some endomysial connective tissue elements, whereas TGase 1 and beta-amyloid proteins were not detectable. In SIBM muscle, both TGases 1 and 2 as well as amyloid proteins were brightly expressed and co-localized in the vacuolated muscle fibers, but none of these proteins colocalized with inflammatory cell markers. Next, we isolated high molecular weight insoluble proteins from SIBM muscle tissue and showed that they were cross-linked by about 6 residues/1000 residues of the isopeptide bond. Furthermore, by amino acid sequencing of solubilized tryptic peptides, they contain amyloid and skeletal muscle proteins. Together, these findings suggest that elevated expression of TGases 1 and 2 participate in the formation of insoluble amyloid deposits in SIBM tissue and in this way may contribute to progressive and debilitating muscle disease.
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Affiliation(s)
- Y C Choi
- Department of Neurology, College of Medicine, Yonsei University, Seoul 135-270, Republic of Korea.
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36
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Abstract
Tissue transglutaminase (tTG) belongs to the family of transglutaminase enzymes that catalyze the posttranslational modification of proteins via Ca(2+)-dependent cross-linking reactions. The catalytic action of tTG results in the formation of an isopeptide bond that is of great physiological significance since it is highly resistant to proteolysis and denaturants. Although tTG-mediated cross-linking reactions have been implicated to play a role in diverse biological processes, the precise physiological function of the enzyme remains unclear. Recent data, however, suggest that the protein polymers resulting from tTG-catalyzed reactions may play a role in commitment of cells to undergo apoptosis. On the same token, tTG-mediated formation of insoluble protein aggregates may underlie the markers of numerous pathological conditions, such as the senile plaques in Alzheimer's disease and the Lewy bodies in Parkinson's disease. In addition to catalyzing Ca(2+)-dependent cross-linking reactions, tTG can also bind and hydrolyze guanosine triphosphate and adenosine triphosphate. By virtue of this ability, tTG has been identified as a novel G-protein that interacts and activates phospholipase C following stimulation of the alpha-adrenergic receptor. The ability of tTG to mediate signal transduction may contribute to its involvement in the regulation of cell cycle progression. The following review summarizes the important features of this multifunctional enzyme that have emerged as a result of recent work from different laboratories.
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Affiliation(s)
- J S Chen
- Department of Bioimmunotherapy, University of Texas, M.D. Anderson Cancer Center, Houston 77030, USA
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37
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Benzinger TL, Gregory DM, Burkoth TS, Miller-Auer H, Lynn DG, Botto RE, Meredith SC. Propagating structure of Alzheimer's beta-amyloid(10-35) is parallel beta-sheet with residues in exact register. Proc Natl Acad Sci U S A 1998; 95:13407-12. [PMID: 9811813 PMCID: PMC24832 DOI: 10.1073/pnas.95.23.13407] [Citation(s) in RCA: 346] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/1998] [Accepted: 08/17/1998] [Indexed: 11/18/2022] Open
Abstract
The pathognomonic plaques of Alzheimer's disease are composed primarily of the 39- to 43-aa beta-amyloid (Abeta) peptide. Crosslinking of Abeta peptides by tissue transglutaminase (tTg) indicates that Gln15 of one peptide is proximate to Lys16 of another in aggregated Abeta. Here we report how the fibril structure is resolved by mapping interstrand distances in this core region of the Abeta peptide chain with solid-state NMR. Isotopic substitution provides the source points for measuring distances in aggregated Abeta. Peptides containing a single carbonyl 13C label at Gln15, Lys16, Leu17, or Val18 were synthesized and evaluated by NMR dipolar recoupling methods for the measurement of interpeptide distances to a resolution of 0.2 A. Analysis of these data establish that this central core of Abeta consists of a parallel beta-sheet structure in which identical residues on adjacent chains are aligned directly, i. e., in register. Our data, in conjunction with existing structural data, establish that the Abeta fibril is a hydrogen-bonded, parallel beta-sheet defining the long axis of the Abeta fibril propagation.
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Affiliation(s)
- T L Benzinger
- Department of Pathology, University of Chicago, Chicago, IL 60637, USA
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Yamada T, Yoshiyama Y, Kawaguchi N, Ichinose A, Iwaki T, Hirose S, Jefferies WA. Possible roles of transglutaminases in Alzheimer's disease. Dement Geriatr Cogn Disord 1998; 9:103-10. [PMID: 9524802 DOI: 10.1159/000017031] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The localizations of two transglutaminases [factor XIIIa and tissue transglutaminase (tTG)] and their mRNAs were examined in human brain tissues from neurologically normal and Alzheimer disease (AD) cases, using immunohistochemical and in situ hybridization methods. In all cases, meningeal macrophages and ependymal macrophage/microglia were positive for factor XIIIa. The mRNA encoding factor XIIIa was detected in macrophages and microglia. As reported previously, intense staining with the antibody to factor XIIIa of a subset of microglia was seen in the parietal cortex in AD brains. Few or no microglia were found associated with classical senile plaques. In contrast, many labeled microglia were associated with primitive plaques. Further-more, most of these cells were mainly seen in the subpial cortical layer but were very rare in the hippocampus. On the other hand, few factor-XIIIa-positive microglia were found in the parietal cortices from non-neurological cases, but moderate numbers were found in their hippocampal tissues. TG and its mRNA were localized in astrocytes in all the cases. In AD, a few neurofibrillary tangles were positive to tTG. These results suggest that the subsets of microglia which express factor XIIIa may play some roles in the early phase of AD pathology.
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Affiliation(s)
- T Yamada
- Department of Neurology, Chiba University, Japan
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Garzon-Rodriguez W, Sepulveda-Becerra M, Milton S, Glabe CG. Soluble amyloid Abeta-(1-40) exists as a stable dimer at low concentrations. J Biol Chem 1997; 272:21037-44. [PMID: 9261105 DOI: 10.1074/jbc.272.34.21037] [Citation(s) in RCA: 180] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Recent studies have implicated the amyloid Abeta peptide and its ability to self-assemble as key factors in the pathogenesis of Alzheimer's disease. Relatively little is known about the structure of soluble Abeta or its oligomeric state, and the existing data are often contradictory. In this study, we used intrinsic fluorescence of wild type Abeta-(1-40), fluorescence resonance energy transfer (FRET), and gel filtration chromatography to examine the structure of Abeta-(1-40) in solution. We synthesized a series of mono-substituted fluorescent Abeta-(1-40) derivatives to use as donors and acceptors in FRET experiments. We selected fluorescent peptides that exhibit aggregation properties comparable to wild type Abeta for analysis in donor-acceptor pairs; two labeled with 5-(2-((iodoacetyl)amino)ethyl)aminonaphthylene-1-sulfonic acid at Cys-25 or Cys-34 and fluorescein maleimide at Cys-4 or Cys-7. Another peptide containing a Trp substitution at position 10 was used as an acceptor for the intrinsic Tyr fluorescence of wild type Abeta-(1-40). Equilibrium studies of the denaturation of Abeta-(1-40) by increasing concentrations of dimethyl sulfoxide (Me2SO) were conducted by monitoring fluorescence, with a midpoint value for the unfolding transition of both the substituted and wild type peptides at among 40 and 50% Me2SO. Abeta-(1-40) is well solvated and largely monomeric in Me2SO as evidenced by a lack of FRET. When donor and acceptor Abeta derivatives are mixed together in Me2SO and then diluted 10-fold into aqueous Tris-HCl buffer at pH 7.4, efficient FRET is observed immediately for all pairs of fluorescent peptides, indicating that donor-acceptor dimers exist in solution. FRET is abolished by the addition of an excess of unlabeled Abeta-(1-40), demonstrating that the fluorescent peptides interact with wild type Abeta-(1-40) to form heterodimers that do not exhibit FRET. The Abeta-(1-40) dimers appear to be very stable, because no subunit exchange is observed after 24 h between fluorescent homodimers. Gel filtration confirms that nanomolar concentrations of 14C-labeled Abeta-(1-40) and fluorescein-labeled Abeta-(1-40) elute at the same dimeric position as wild type Abeta-(1-40), suggesting that soluble Abeta-(1-40) is also dimeric at more physiologically plausible concentrations.
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Affiliation(s)
- W Garzon-Rodriguez
- Department of Molecular Biology and Biochemistry, University of California, Irvine, California 92696, USA
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Abstract
Recent neuropathological evidence suggests that synapse pathology is the major correlate of cognitive decline in Alzheimer's disease (AD) patients, but also in other dementia syndromes. We suggest that synapse loss in AD-patients mainly reflects neuronal destruction in other iso- and allocortical areas as well as in brain stem nuclei. In addition an impaired compensatory synaptogenesis may contribute to the reduction in synaptic connectivity. The patterns of cell death in AD-brains determined by analysis of DNA-fragmentation in situ revealed significantly higher numbers of dying cells (neurons as well as glia cells) in AD-brains compared to controls. Amyloid deposition as well as neurofibrillary pathology apparently do not induce cell death directly, but may increase the risk of cells to die in response to additional minor metabolic insults. We propose that multiple pathogenetic factors are involved in the reduction of synaptic connectivity in AD-brains, which finally is reflected in the decline of cognitive functions.
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Affiliation(s)
- H Lassmann
- Research Unit for Experimental Neuropathology, Austrian Academy of Sciences, Vienna, Austria
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Jensen PH, Sørensen ES, Petersen TE, Gliemann J, Rasmussen LK. Residues in the synuclein consensus motif of the alpha-synuclein fragment, NAC, participate in transglutaminase-catalysed cross-linking to Alzheimer-disease amyloid beta A4 peptide. Biochem J 1995; 310 ( Pt 1):91-4. [PMID: 7646476 PMCID: PMC1135858 DOI: 10.1042/bj3100091] [Citation(s) in RCA: 76] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The widespread deposition of amyloid plaques is one of the hallmarks of Alzheimer disease (AD). A recently described component of amyloid plaques is the 35-residue peptide, non-A beta component of AD amyloid, which is derived from a larger intracellular neuronal constituent, alpha-synuclein. We demonstrate that transglutaminase catalyses the formation of the covalent non-A beta component of AD amyloid polymers in vitro as well as polymers with beta-amyloid peptide, the major constituent of AD plaques. The transglutaminase-reactive amino acid residues in the non-A beta component of AD amyloid were identified as Gln79 and Lys80. Lys80 is localized in a consensus motif Lys-Thr-Lys-Glu-Gly-Val, which is conserved in the synuclein gene family. Thus transglutaminase might be involved in the formation of insoluble amyloid deposits and participate in the modification of other members of the synuclein family.
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Affiliation(s)
- P H Jensen
- Department of Medical Biochemistry, University of Aarhus, Denmark
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