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Lockridge O, Schopfer LM. Naturally Occurring Epsilon Gamma Glutamyl Lysine Isopeptide Crosslinks in Human Neuroblastoma SH-SY5Y Cells. ACS OMEGA 2022; 7:21978-21986. [PMID: 35785306 PMCID: PMC9245130 DOI: 10.1021/acsomega.2c02502] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Accepted: 06/07/2022] [Indexed: 05/05/2023]
Abstract
Zero-length isopeptide crosslinks between the side chains of glutamine and lysine are the product of transglutaminase activity. It is generally accepted that transglutaminase activity is dormant under physiological conditions because the calcium concentration inside cells is too low to activate transglutaminase to an open conformation with access to the catalytic triad. Traditional assays for transglutaminase activity measure incorporation of biotin pentylamine or of radiolabeled putrescine in the presence of added calcium. In this report, we identified naturally occurring isopeptide crosslinked proteins using the following steps: immunopurification of tryptic peptides by binding to anti-isopeptide antibody 81D1C2, separation of immunopurified peptides by liquid chromatography-tandem mass spectrometry, Protein Prospector database searches of mass spectrometry data for isopeptide crosslinked peptides, and manual evaluation of candidate crosslinked peptide pairs. The most labor intense step was manual evaluation. We developed criteria for accepting and rejecting candidate crosslinked peptides and showed examples of MS/MS spectra that confirm or invalidate a possible crosslink. The SH-SY5Y cells that we examined for crosslinked proteins had not been exposed to calcium and had been lysed in the presence of ethylenediaminetetraacetic acid. This precaution allows us to claim that the crosslinks we found inside the cells occurred naturally under physiological conditions. The quantity of crosslinks was very low, and the crosslinked proteins were mostly low abundance proteins. In conclusion, intracellular transglutaminase crosslinking/transamidase activity is very low but detectable. The low level of intracellular crosslinked proteins is consistent with tight regulation of transglutaminase activity.
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Keillor JW, Johnson GVW. Transglutaminase 2 as a therapeutic target for neurological conditions. Expert Opin Ther Targets 2021; 25:721-731. [PMID: 34607527 DOI: 10.1080/14728222.2021.1989410] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Accepted: 10/01/2021] [Indexed: 12/14/2022]
Abstract
INTRODUCTION Transglutaminase 2 (TG2) has been implicated in numerous neurological conditions, including neurodegenerative diseases, multiple sclerosis, and CNS injury. Early studies on the role of TG2 in neurodegenerative conditions focused on its ability to 'crosslink' proteins into insoluble aggregates. However, more recent studies have suggested that this is unlikely to be the primary mechanism by which TG2 contributes to the pathogenic processes. Although the specific mechanisms by which TG2 is involved in neurological conditions have not been clearly defined, TG2 regulates numerous cellular processes through which it could contribute to a specific disease. Given the fact that TG2 is a stress-induced gene and elevated in disease or injury conditions, TG2 inhibitors may be useful neurotherapeutics. AREAS COVERED Overview of TG2 and different TG2 inhibitors. A brief review of TG2 in neurodegenerative diseases, multiple sclerosis and CNS injury and inhibitors that have been tested in different models. Database search: https://pubmed.ncbi.nlm.nih.gov prior to 1 July 2021. EXPERT OPINION Currently, it appears unlikely that inhibiting TG2 in the context of neurodegenerative diseases would be therapeutically advantageous. However, for multiple sclerosis and CNS injuries, TG2 inhibitors may have the potential to be therapeutically useful and thus there is rationale for their further development.
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Affiliation(s)
- Jeffrey W Keillor
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON, Canada
| | - Gail V W Johnson
- Department of Anesthesiology and Perioperative Medicine, University of Rochester, Rochester, NY, USA
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Tatsukawa H, Hitomi K. Role of Transglutaminase 2 in Cell Death, Survival, and Fibrosis. Cells 2021; 10:cells10071842. [PMID: 34360011 PMCID: PMC8307792 DOI: 10.3390/cells10071842] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Revised: 07/12/2021] [Accepted: 07/13/2021] [Indexed: 12/27/2022] Open
Abstract
Transglutaminase 2 (TG2) is a ubiquitously expressed enzyme catalyzing the crosslinking between Gln and Lys residues and involved in various pathophysiological events. Besides this crosslinking activity, TG2 functions as a deamidase, GTPase, isopeptidase, adapter/scaffold, protein disulfide isomerase, and kinase. It also plays a role in the regulation of hypusination and serotonylation. Through these activities, TG2 is involved in cell growth, differentiation, cell death, inflammation, tissue repair, and fibrosis. Depending on the cell type and stimulus, TG2 changes its subcellular localization and biological activity, leading to cell death or survival. In normal unstressed cells, intracellular TG2 exhibits a GTP-bound closed conformation, exerting prosurvival functions. However, upon cell stimulation with Ca2+ or other factors, TG2 adopts a Ca2+-bound open conformation, demonstrating a transamidase activity involved in cell death or survival. These functional discrepancies of TG2 open form might be caused by its multifunctional nature, the existence of splicing variants, the cell type and stimulus, and the genetic backgrounds and variations of the mouse models used. TG2 is also involved in the phagocytosis of dead cells by macrophages and in fibrosis during tissue repair. Here, we summarize and discuss the multifunctional and controversial roles of TG2, focusing on cell death/survival and fibrosis.
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Zahedi K, Brooks M, Barone S, Rahmati N, Murray Stewart T, Dunworth M, Destefano-Shields C, Dasgupta N, Davidson S, Lindquist DM, Fuller CE, Smith RD, Cleveland JL, Casero RA, Soleimani M. Ablation of polyamine catabolic enzymes provokes Purkinje cell damage, neuroinflammation, and severe ataxia. J Neuroinflammation 2020; 17:301. [PMID: 33054763 PMCID: PMC7559641 DOI: 10.1186/s12974-020-01955-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Accepted: 09/17/2020] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Polyamine catabolism plays a key role in maintaining intracellular polyamine pools, yet its physiological significance is largely unexplored. Here, we report that the disruption of polyamine catabolism leads to severe cerebellar damage and ataxia, demonstrating the fundamental role of polyamine catabolism in the maintenance of cerebellar function and integrity. METHODS Mice with simultaneous deletion of the two principal polyamine catabolic enzymes, spermine oxidase and spermidine/spermine N1-acetyltransferase (Smox/Sat1-dKO), were generated by the crossbreeding of Smox-KO (Smox-/-) and Sat1-KO (Sat1-/-) animals. Development and progression of tissue injury was monitored using imaging, behavioral, and molecular analyses. RESULTS Smox/Sat1-dKO mice are normal at birth, but develop progressive cerebellar damage and ataxia. The cerebellar injury in Smox/Sat1-dKO mice is associated with Purkinje cell loss and gliosis, leading to neuroinflammation and white matter demyelination during the latter stages of the injury. The onset of tissue damage in Smox/Sat1-dKO mice is not solely dependent on changes in polyamine levels as cerebellar injury was highly selective. RNA-seq analysis and confirmatory studies revealed clear decreases in the expression of Purkinje cell-associated proteins and significant increases in the expression of transglutaminases and markers of neurodegenerative microgliosis and astrocytosis. Further, the α-Synuclein expression, aggregation, and polyamination levels were significantly increased in the cerebellum of Smox/Sat1-dKO mice. Finally, there were clear roles of transglutaminase-2 (TGM2) in the cerebellar pathologies manifest in Smox/Sat1-dKO mice, as pharmacological inhibition of transglutaminases reduced the severity of ataxia and cerebellar injury in Smox/Sat1-dKO mice. CONCLUSIONS These results indicate that the disruption of polyamine catabolism, via coordinated alterations in tissue polyamine levels, elevated transglutaminase activity and increased expression, polyamination, and aggregation of α-Synuclein, leads to severe cerebellar damage and ataxia. These studies indicate that polyamine catabolism is necessary to Purkinje cell survival, and for sustaining the functional integrity of the cerebellum.
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Affiliation(s)
- Kamyar Zahedi
- Department of Medicine, University of Cincinnati College of Medicine, Cincinnati, OH, 45267, USA.
- Research Services, Veterans Affairs Medical Center, Cincinnati, OH, 45220, USA.
- Department of Medicine, University of New Mexico Health Sciences Center, Albuquerque, NM, 87131, USA.
- Research Services, Veterans Affairs Medical Center, Albuquerque, NM, 87108, USA.
- Department of Internal Medicine, Division of Nephrology, University of New Mexico College of Medicine, 915 Camino de Salud, Bldg. 289, IDTC 3315, Albuquerque, NM, 87113, USA.
- Present Address: Department of Internal Medicine, Division of Nephrology, University of New Mexico College of Medicine, Albuquerque, NM, 87131, USA.
| | - Marybeth Brooks
- Research Services, Veterans Affairs Medical Center, Cincinnati, OH, 45220, USA
- Department of Medicine, University of New Mexico Health Sciences Center, Albuquerque, NM, 87131, USA
- Present Address: Department of Internal Medicine, Division of Nephrology, University of New Mexico College of Medicine, Albuquerque, NM, 87131, USA
| | - Sharon Barone
- Department of Medicine, University of Cincinnati College of Medicine, Cincinnati, OH, 45267, USA
- Research Services, Veterans Affairs Medical Center, Cincinnati, OH, 45220, USA
- Department of Medicine, University of New Mexico Health Sciences Center, Albuquerque, NM, 87131, USA
- Research Services, Veterans Affairs Medical Center, Albuquerque, NM, 87108, USA
- Present Address: Department of Internal Medicine, Division of Nephrology, University of New Mexico College of Medicine, Albuquerque, NM, 87131, USA
| | - Negah Rahmati
- Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, 02129, USA
| | - Tracy Murray Stewart
- The Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, MD, 21231, USA
| | - Matthew Dunworth
- The Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, MD, 21231, USA
| | - Christina Destefano-Shields
- The Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, MD, 21231, USA
| | - Nupur Dasgupta
- The Division of Human Genetics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, 45229, USA
| | - Steve Davidson
- Department of Anesthesiology and Pain Research Center, University of Cincinnati College of Medicine, Cincinnati, OH, 45267, USA
| | - Diana M Lindquist
- Department of Radiology, University of Cincinnati, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, 45229, USA
| | - Christine E Fuller
- Upstate Medical University Department of Pathology, Syracuse, NY, 13219, USA
| | - Roger D Smith
- Department of Pathology and Laboratory Medicine, University of Cincinnati College of Medicine, Cincinnati, OH, 45267, USA
| | - John L Cleveland
- Department of Tumor Biology, Moffitt Cancer Center and Research Institute, Tampa, FL, USA
- Department of Cancer Biology, The Scripps Research Institute, Jupiter, FL, USA
| | - Robert A Casero
- The Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, MD, 21231, USA
| | - Manoocher Soleimani
- Department of Medicine, University of Cincinnati College of Medicine, Cincinnati, OH, 45267, USA.
- Research Services, Veterans Affairs Medical Center, Cincinnati, OH, 45220, USA.
- Department of Medicine, University of New Mexico Health Sciences Center, Albuquerque, NM, 87131, USA.
- Research Services, Veterans Affairs Medical Center, Albuquerque, NM, 87108, USA.
- Department of Internal Medicine, Division of Nephrology, University of New Mexico College of Medicine, 915 Camino de Salud, Bldg. 289, IDTC 3315, Albuquerque, NM, 87113, USA.
- Present Address: Department of Internal Medicine, Division of Nephrology, University of New Mexico College of Medicine, Albuquerque, NM, 87131, USA.
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De Simone A, Bartolini M, Baschieri A, Apperley KYP, Chen HH, Guardigni M, Montanari S, Kobrlova T, Soukup O, Valgimigli L, Andrisano V, Keillor JW, Basso M, Milelli A. Hydroxy-substituted trans-cinnamoyl derivatives as multifunctional tools in the context of Alzheimer's disease. Eur J Med Chem 2017; 139:378-389. [PMID: 28810189 DOI: 10.1016/j.ejmech.2017.07.058] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Revised: 05/29/2017] [Accepted: 07/24/2017] [Indexed: 11/25/2022]
Abstract
Alzheimer's disease (AD) is a multifactorial pathology that requires multifaceted agents able to address its peculiar nature. In recent years, a plethora of proteins and biochemical pathways has been proposed as possible targets to counteract neurotoxicity. Although the complex scenario is not completely elucidated, close relationships are emerging among some of these actors. In particular, increasing evidence has shown that aggregation of amyloid beta (Aβ), glycogen synthase kinase 3β (GSK-3β) and oxidative stress are strictly interconnected and their concomitant modulation may have a positive and synergic effect in contrasting AD-related impairments. We designed compound 3 which demonstrated the ability to inhibit both GSK-3β (IC50 = 24.36 ± 0.01 μM) and Aβ42 self-aggregation (IC50 = 9.0 ± 1.4 μM), to chelate copper (II) and to act as exceptionally strong radical scavenger (kinh = 6.8 ± 0.5 · 105 M-1s-1) even in phosphate buffer at pH 7.4 (kinh = 3.2 ± 0.5 · 105 M-1s-1). Importantly, compound 3 showed high-predicted blood-brain barrier permeability, did not exert any significant cytotoxic effects in immature cortical neurons up to 50 μM and showed neuroprotective properties at micromolar concentration against toxic insult induced by glutamate.
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Affiliation(s)
- Angela De Simone
- Department for Life Quality Studies, Alma Mater Studiorum-University of Bologna, Corso d'Augusto 237, 47921 Rimini, Italy
| | - Manuela Bartolini
- Department of Pharmacy and Biotechnology, Alma Mater Studiorum-University of Bologna, Via Belmeloro 6, 40126 Bologna, Italy
| | - Andrea Baschieri
- Department of Chemistry "G. Ciamician", Alma Mater Studiorum-University of Bologna, Via S. Giacomo 11, 40126 Bologna, Italy
| | - Kim Y P Apperley
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, 10 Marie-Curie, Ottawa, ON, K1N 6N5, Canada
| | - Huan Huan Chen
- Department for Life Quality Studies, Alma Mater Studiorum-University of Bologna, Corso d'Augusto 237, 47921 Rimini, Italy
| | - Melissa Guardigni
- Department for Life Quality Studies, Alma Mater Studiorum-University of Bologna, Corso d'Augusto 237, 47921 Rimini, Italy
| | - Serena Montanari
- Department for Life Quality Studies, Alma Mater Studiorum-University of Bologna, Corso d'Augusto 237, 47921 Rimini, Italy
| | - Tereza Kobrlova
- Biomedical Research Center, University Hospital, Sokolska 581, 500 05 Hradec Kralove, Czech Republic
| | - Ondrej Soukup
- Biomedical Research Center, University Hospital, Sokolska 581, 500 05 Hradec Kralove, Czech Republic
| | - Luca Valgimigli
- Department of Chemistry "G. Ciamician", Alma Mater Studiorum-University of Bologna, Via S. Giacomo 11, 40126 Bologna, Italy
| | - Vincenza Andrisano
- Department for Life Quality Studies, Alma Mater Studiorum-University of Bologna, Corso d'Augusto 237, 47921 Rimini, Italy
| | - Jeffrey W Keillor
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, 10 Marie-Curie, Ottawa, ON, K1N 6N5, Canada
| | - Manuela Basso
- Laboratory of Transcriptional Neurobiology, Centre for Integrative Biology, University of Trento, Via Sommarive 9, 38123 Trento, Italy
| | - Andrea Milelli
- Department for Life Quality Studies, Alma Mater Studiorum-University of Bologna, Corso d'Augusto 237, 47921 Rimini, Italy.
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André W, Nondier I, Valensi M, Guillonneau F, Federici C, Hoffner G, Djian P. Identification of brain substrates of transglutaminase by functional proteomics supports its role in neurodegenerative diseases. Neurobiol Dis 2017; 101:40-58. [DOI: 10.1016/j.nbd.2017.01.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Revised: 01/21/2017] [Accepted: 01/25/2017] [Indexed: 12/21/2022] Open
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Tatsukawa H, Furutani Y, Hitomi K, Kojima S. Transglutaminase 2 has opposing roles in the regulation of cellular functions as well as cell growth and death. Cell Death Dis 2016; 7:e2244. [PMID: 27253408 PMCID: PMC5143380 DOI: 10.1038/cddis.2016.150] [Citation(s) in RCA: 89] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Revised: 04/28/2016] [Accepted: 04/28/2016] [Indexed: 01/27/2023]
Abstract
Transglutaminase 2 (TG2) is primarily known as the most ubiquitously expressed member of the transglutaminase family with Ca2+-dependent protein crosslinking activity; however, this enzyme exhibits multiple additional functions through GTPase, cell adhesion, protein disulfide isomerase, kinase, and scaffold activities and is associated with cell growth, differentiation, and apoptosis. TG2 is found in the extracellular matrix, plasma membrane, cytosol, mitochondria, recycling endosomes, and nucleus, and its subcellular localization is an important determinant of its function. Depending upon the cell type and stimuli, TG2 changes its subcellular localization and biological activities, playing both anti- and pro-apoptotic roles. Increasing evidence indicates that the GTP-bound form of the enzyme (in its closed form) protects cells from apoptosis but that the transamidation activity of TG2 (in its open form) participates in both facilitating and inhibiting apoptosis. A difficulty in the study and understanding of this enigmatic protein is that opposing effects have been reported regarding its roles in the same physiological and/or pathological systems. These include neuroprotective or neurodegenerative effects, hepatic cell growth-promoting or hepatic cell death-inducing effects, exacerbating or having no effect on liver fibrosis, and anti- and pro-apoptotic effects on cancer cells. The reasons for these discrepancies have been ascribed to TG2's multifunctional activities, genetic variants, conformational changes induced by the immediate environment, and differences in the genetic background of the mice used in each of the experiments. In this article, we first report that TG2 has opposing roles like the protagonist in the novel Dr. Jekyll and Mr. Hyde, followed by a summary of the controversies reported, and finally discuss the possible reasons for these discrepancies.
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Affiliation(s)
- H Tatsukawa
- Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Nagoya 464-8601, Japan
| | - Y Furutani
- Micro-Signaling Regulation Technology Unit, RIKEN Center for Life Science Technologies, 2-1 Hirosawa, Saitama 351-0198, Japan
| | - K Hitomi
- Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Nagoya 464-8601, Japan
| | - S Kojima
- Micro-Signaling Regulation Technology Unit, RIKEN Center for Life Science Technologies, 2-1 Hirosawa, Saitama 351-0198, Japan
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8
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Wilhelmus MMM, Drukarch B. Tissue transglutaminase is a biochemical marker for Alzheimer's disease. Neurobiol Aging 2013; 35:e3-4. [PMID: 24080177 DOI: 10.1016/j.neurobiolaging.2013.08.022] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2013] [Revised: 08/15/2013] [Accepted: 08/20/2013] [Indexed: 10/26/2022]
Affiliation(s)
- Micha M M Wilhelmus
- Department of Anatomy and Neurosciences, Cellular Neuropharmacology Section, Neuroscience Campus Amsterdam, VU University Medical Center, Amsterdam, the Netherlands.
| | - Benjamin Drukarch
- Department of Anatomy and Neurosciences, Cellular Neuropharmacology Section, Neuroscience Campus Amsterdam, VU University Medical Center, Amsterdam, the Netherlands
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9
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Transglutaminase is a therapeutic target for oxidative stress, excitotoxicity and stroke: a new epigenetic kid on the CNS block. J Cereb Blood Flow Metab 2013; 33:809-18. [PMID: 23571278 PMCID: PMC3677119 DOI: 10.1038/jcbfm.2013.53] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Transglutaminases (TGs) are multifunctional, calcium-dependent enzymes that have been recently implicated in stroke pathophysiology. Classically, these enzymes are thought to participate in cell injury and death in chronic neurodegenerative conditions via their ability to catalyze covalent, nondegradable crosslinks between proteins or to incorporate polyamines into protein substrates. Accumulating lines of inquiry indicate that specific TG isoforms can shuttle into the nucleus when they sense pathologic changes in calcium or oxidative stress, bind to chromatin and thereby transduce these changes into transcriptional repression of genes involved in metabolic or oxidant adaptation. Here, we review the evidence that supports principally a role for one isoform of this family, TG2, in cell injury and death associated with hemorrhagic or ischemic stroke. We also outline an evolving model in which TG2 is a critical mediator between pathologic signaling and epigenetic modifications that lead to gene repression. Accordingly, the salutary effects of TG inhibitors in stroke may derive from their ability to restore homeostasis by removing inappropriate deactivation of adaptive genetic programs by oxidative stress or extrasynaptic glutamate receptor signaling.
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10
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Kuo TF, Tatsukawa H, Kojima S. New insights into the functions and localization of nuclear transglutaminase 2. FEBS J 2011; 278:4756-67. [PMID: 22051117 DOI: 10.1111/j.1742-4658.2011.08409.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Transglutaminase 2 (TG2; EC 2.3.2.13) is the most abundantly expressed member of the transglutaminase family and exerts opposing effects on cell growth, differentiation and apoptosis via multiple activities, including transamidase, GTPase, cell adhesion, protein disulfide isomerase, kinase and scaffold activities. It is distributed in and around various parts of a cell, including the extracellular matrix, plasma membrane, cytosol, mitochondria and nucleus. Generally, nuclear TG2 represents only 5-7% of the total TG2 in a cell, and various stimuli will increase nuclear TG2 via cellular stress and/or an increased intracellular Ca(2+) concentration. There is increasing evidence indicating the importance of nuclear TG2 in regulating gene expression via post-translational modification of (or interaction with) transcriptional factors and related proteins. These include E2F1, hypoxia inducible factor 1, Sp1 and histones. Through this mechanism, TG2 controls cell growth or survival, differentiation and apoptosis, and is involved in the pathogenesis and/or treatment of neurodegenerative diseases, liver diseases and cancers. The balance between import from the cytoplasm to the nucleus, and export from the nucleus to the cytoplasm, determines the level of TG2 in the nucleus. Selective regulation of the expression, activity or localization of nuclear TG2 will be important for basic research, as well as clinical applications, suggesting a new era for this long-studied enzyme.
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Affiliation(s)
- Ting-Fang Kuo
- Chemical Biology Department, RIKEN Advanced Science Institute, Wako, Saitama, Japan
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11
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Cellular model of Alzheimer's disease--relevance to therapeutic testing. Exp Neurol 2011; 233:733-9. [PMID: 22119424 DOI: 10.1016/j.expneurol.2011.11.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2011] [Revised: 10/26/2011] [Accepted: 11/08/2011] [Indexed: 12/29/2022]
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12
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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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13
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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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14
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Piacentini M, D'Eletto M, Falasca L, Farrace MG, Rodolfo C. Transglutaminase 2 at the crossroads between cell death and survival. ADVANCES IN ENZYMOLOGY AND RELATED AREAS OF MOLECULAR BIOLOGY 2011; 78:197-246. [PMID: 22220475 DOI: 10.1002/9781118105771.ch5] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Mauro Piacentini
- Department of Biology, University of Rome "Tor Vergata", Rome, Italy
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15
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Martin A, Giuliano A, Collaro D, De Vivo G, Sedia C, Serretiello E, Gentile V. Possible involvement of transglutaminase-catalyzed reactions in the physiopathology of neurodegenerative diseases. Amino Acids 2011; 44:111-8. [DOI: 10.1007/s00726-011-1081-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2011] [Accepted: 09/08/2011] [Indexed: 02/03/2023]
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16
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Corbo CP, Alonso ADC. Therapeutic targets in Alzheimer's disease and related tauopathies. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2011; 98:47-83. [PMID: 21199770 DOI: 10.1016/b978-0-12-385506-0.00002-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Alzheimer's disease is a progressive neurodegenerative disease that is characterized histopathologically by the presence of plaques, mainly composed of Abeta amyloid and the tangles, mainly composed of hyperphosphorylated tau. To date, there is no treatment that can reverse the disease, and all the current therapeutics is directed to cope with the symptoms of the disease. Here we describe the efforts dedicated to attack the plaques and, in more detail, the process of neurofibrillary degeneration, linked to the presence of the hyperphosphorylated microtubule associated protein tau. We have identified the different putative targets for therapeutics and the current knowledge on them.
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Affiliation(s)
- Christopher P Corbo
- College of Staten Island, Program in evelopmental Neuroscience, The Graduate Center, City University of New York (CUNY), Staten Island, New York, USA
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17
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Wilhelmus MMM, Verhaar R, Andringa G, Bol JGJM, Cras P, Shan L, Hoozemans JJM, Drukarch B. Presence of tissue transglutaminase in granular endoplasmic reticulum is characteristic of melanized neurons in Parkinson's disease brain. Brain Pathol 2011; 21:130-9. [PMID: 20731657 PMCID: PMC8094245 DOI: 10.1111/j.1750-3639.2010.00429.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2010] [Accepted: 07/09/2010] [Indexed: 01/18/2023] Open
Abstract
Parkinson's disease (PD) is characterized by the accumulation of α-synuclein aggregates and degeneration of melanized neurons. The tissue transglutaminase (tTG) enzyme catalyzes molecular protein cross-linking. In PD brain, tTG-induced cross-links have been identified in α-synuclein monomers, oligomers and α-synuclein aggregates. However, whether tTG and α-synuclein occur together in PD affected neurons remains to be established. Interestingly, using immunohistochemistry, we observed a granular distribution pattern of tTG, characteristic of melanized neurons in PD brain. Apart from tTG, these granules were also positive for typical endoplasmic reticulum (ER)-resident chaperones, that is, protein disulphide isomerase, ERp57 and calreticulin, suggesting a direct link to the ER. Additionally, we observed the presence of phosphorylated pancreatic ER kinase (pPERK), a classical ER stress marker, in tTG granule positive neurons in PD brain, although no subcellular colocalization of tTG and pPERK was found. Our data therefore suggest that tTG localization to granular ER compartments is specific for stressed melanized neurons in PD brain. Moreover, as also α-synuclein aggregates were observed in tTG granule positive neurons, these results provide a clue to the cellular site of interaction between α-synuclein and tTG.
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Affiliation(s)
- Micha M M Wilhelmus
- Department of Anatomy and Neurosciences, Neuroscience Campus Amsterdam, VU University Medical Center, the Netherlands.
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Martin A, De Vivo G, Gentile V. Possible role of the transglutaminases in the pathogenesis of Alzheimer's disease and other neurodegenerative diseases. Int J Alzheimers Dis 2011; 2011:865432. [PMID: 21350675 PMCID: PMC3042675 DOI: 10.4061/2011/865432] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2010] [Accepted: 01/05/2011] [Indexed: 12/30/2022] Open
Abstract
Transglutaminases are ubiquitous enzymes which catalyze posttranslational modifications of proteins. Recently, transglutaminase-catalyzed post-translational modification of proteins has been shown to be involved in the molecular mechanisms responsible for human diseases. Transglutaminase activity has been hypothesized to be involved also in the pathogenetic mechanisms responsible for several human neurodegenerative diseases. Alzheimer's disease and other neurodegenerative diseases, such as Parkinson's disease, supranuclear palsy, Huntington's disease, and other polyglutamine diseases, are characterized in part by aberrant cerebral transglutaminase activity and by increased cross-linked proteins in affected brains. This paper focuses on the possible molecular mechanisms by which transglutaminase activity could be involved in the pathogenesis of Alzheimer's disease and other neurodegenerative diseases, and on the possible therapeutic effects of selective transglutaminase inhibitors for the cure of patients with diseases characterized by aberrant transglutaminase activity.
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Affiliation(s)
- Antonio Martin
- Department of Biochemistry and Biophysics, Second University of Naples, Via Costantinopoli 16, 80138 Naples, Italy
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19
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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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20
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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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21
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Caccamo D, Currò M, Condello S, Ferlazzo N, Ientile R. Critical role of transglutaminase and other stress proteins during neurodegenerative processes. Amino Acids 2009; 38:653-8. [PMID: 19960212 DOI: 10.1007/s00726-009-0428-3] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2009] [Accepted: 09/06/2009] [Indexed: 11/29/2022]
Abstract
Proteolytic stress, resulting from the intracellular accumulation of misfolded or aggregated proteins, which exceed the capacity of the ubiquitin-proteasome system to degrade them, plays a relevant role in neurodegenerative disorders, such as Alzheimer's disease, Parkinson's disease, and Huntington's chorea. Most of toxic protein aggregates are characterised by the presence of isopeptide bonds (cross-links) catalysed by transglutaminase activity; further, several disease-specific proteins-tau, amyloid-beta, alpha-synuclein, huntingtin-are in vitro and/or in vivo substrates of transglutaminase 2. These findings suggest an important role for transglutaminase 2-mediated cross-linking reactions in neurodegeneration. Therefore, the use of transglutaminase activity inhibitors could ameliorate neuronal cell death. New therapeutic perspectives also arise from the possibility to prevent or reduce protein aggregation by enhancing the activation of heat shock proteins, which have been shown to be potent suppressors of neurodegeneration in cell cultures/animal models. Interestingly, some heat shock proteins have been shown to be in vitro or in vivo cross-linked by transglutaminase 2. These observations seem to suggest that transglutaminase activity could be involved in the stabilization of intracellular protein aggregates by interfering with proteasomal degradation of misfolded proteins. Further studies are needed to validate leading hypotheses and to open new prospects for developing therapeutic tools.
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Affiliation(s)
- Daniela Caccamo
- Department of Biochemical, Physiological and Nutritional Sciences, Policlinico Universitario, University of Messina, Via Consolare Valeria, 98125 Messina, Italy
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Yu JT, Chang RCC, Tan L. Calcium dysregulation in Alzheimer's disease: from mechanisms to therapeutic opportunities. Prog Neurobiol 2009; 89:240-55. [PMID: 19664678 DOI: 10.1016/j.pneurobio.2009.07.009] [Citation(s) in RCA: 112] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2009] [Revised: 07/28/2009] [Accepted: 07/31/2009] [Indexed: 11/28/2022]
Abstract
Calcium is involved in many facets of neuronal physiology, including activity, growth and differentiation, synaptic plasticity, and learning and memory, as well as pathophysiology, including necrosis, apoptosis, and degeneration. Though disturbances in calcium homeostasis in cells from Alzheimer's disease (AD) patients have been observed for many years, much more attention was focused on amyloid-beta (Abeta) and tau as key causative factors for the disease. Nevertheless, increasing lines of evidence have recently reported that calcium dysregulation plays a central role in AD pathogenesis. Systemic calcium changes accompany almost the whole brain pathology process that is observed in AD, including synaptic dysfunction, mitochondrial dysfunction, presenilins mutation, Abeta production and Tau phosphorylation. Given the early and ubiquitous involvement of calcium dysregulation in AD pathogenesis, it logically presents a variety of potential therapeutic targets for AD prevention and treatment, such as calcium channels in the plasma membrane, calcium channels in the endoplasmic reticulum membrane, Abeta-formed calcium channels, calcium-related proteins. The review aims to provide an overview of the current understanding of the molecular mechanisms involved in calcium dysregulation in AD, and an insight on how to exploit calcium regulation as therapeutic opportunities in AD.
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Affiliation(s)
- Jin-Tai Yu
- Department of Neurology, Qingdao Municipal Hospital, School of Medicine, Qingdao University, No. 5 Donghai Middle Road, Qingdao, Shandong Province 266071, China
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23
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The impact of genetic and environmental factors on the pathobiology of Alzheimer's disease: a multifactorial disorder? Int Rev Psychiatry 2009. [DOI: 10.3109/09540269509022988] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Jeitner TM, Muma NA, Battaile KP, Cooper AJ. Transglutaminase activation in neurodegenerative diseases. FUTURE NEUROLOGY 2009; 4:449-467. [PMID: 20161049 DOI: 10.2217/fnl.09.17] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The following review examines the role of calcium in promoting the in vitro and in vivo activation of transglutaminases in neurodegenerative disorders. Diseases such as Alzheimer's disease, Parkinson's disease and Huntington's disease exhibit increased transglutaminase activity and rises in intracellular calcium concentrations, which may be related. The aberrant activation of transglutaminase by calcium is thought to give rise to a variety of pathological moieties in these diseases, and the inhibition has been shown to have therapeutic benefit in animal and cellular models of neurodegeneration. Given the potential clinical relevance of transglutaminase inhibitors, we have also reviewed the recent development of such compounds.
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Affiliation(s)
- Thomas M Jeitner
- Applied Bench Core, Winthrop University Hospital, 222 Station Plaza North, Suite 502, Mineola, NY 11501, USA Tel.: +1 516 663 3455
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25
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Wilhelmus MMM, Verhaar R, Bol JGJM, van Dam AM, Hoozemans JJM, Rozemuller AJM, Drukarch B. Novel role of transglutaminase 1 in corpora amylacea formation? Neurobiol Aging 2009; 32:845-56. [PMID: 19464759 DOI: 10.1016/j.neurobiolaging.2009.04.019] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2008] [Revised: 04/06/2009] [Accepted: 04/21/2009] [Indexed: 10/20/2022]
Abstract
Corpora amylacea (CA) are both age and neurodegeneration-related spherical bodies, consisting of polymerized proteins, often thought to be involved in sequestration of hazardous products of cellular metabolism in brain. Although CA formation is associated with cellular stress, the process underlying their formation remains obscure. Transglutaminases (TGs) are stress associated enzymes that induce molecular cross-links, leading to polymerization of substrate proteins. TG expression and activity are elevated in Alzheimer's disease (AD) and Parkinson's disease (PD), and TG-catalyzed cross-links are present in their lesions. Considering the nature of CA, the aim of this study was to investigate the presence of TGs and TG cross-links in CA of healthy aging brain, AD and PD brain, using immunohistochemistry. We observed TG1 and TG cross-links in CA, together with typical cytoskeletal proteins. Furthermore, the presence of proteins associated with AD or PD pathogenesis was not altered in CA of disease brain compared to controls. We propose that TG1-catalyzed cross-linking and consequent polymerization of cytoskeletal and cytoskeleton-associated proteins may underlie CA formation.
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Affiliation(s)
- Micha M M Wilhelmus
- Department of Anatomy and Neurosciences, VU University Medical Center, Neuroscience Campus Amsterdam, The Netherlands.
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26
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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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27
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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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28
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Ahhmed AM, Kuroda R, Kawahara S, Ohta K, Nakade K, Aoki T, Muguruma M. Dependence of microbial transglutaminase on meat type in myofibrillar proteins cross-linking. Food Chem 2009. [DOI: 10.1016/j.foodchem.2008.05.078] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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29
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Wilhelmus MMM, Grunberg SCS, Bol JGJM, van Dam AM, Hoozemans JJM, Rozemuller AJM, Drukarch B. Transglutaminases and transglutaminase-catalyzed cross-links colocalize with the pathological lesions in Alzheimer's disease brain. Brain Pathol 2008; 19:612-22. [PMID: 18673368 DOI: 10.1111/j.1750-3639.2008.00197.x] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Alzheimer's disease (AD) is characterized by pathological lesions, in particular senile plaques (SPs), cerebral amyloid angiopathy (CAA) and neurofibrillary tangles (NFTs), predominantly consisting of self-aggregated proteins amyloid beta (Abeta) and tau, respectively. Transglutaminases (TGs) are inducible enzymes, capable of modifying conformational and/or structural properties of proteins by inducing molecular covalent cross-links. Both Abeta and tau are substrates for TG cross-linking activity, which links TGs to the aggregation process of both proteins in AD brain. The aim of this study was to investigate the association of transglutaminase 1 (TG1), transglutaminase 2 (TG2) and TG-catalyzed cross-links with the pathological lesions of AD using immunohistochemistry. We observed immunoreactivity for TG1, TG2 and TG-catalyzed cross-links in NFTs. In addition, both TG2 and TG-catalyzed cross-links colocalized with Abeta in SPs. Furthermore, both TG2 and TG-catalyzed cross-links were associated with CAA. We conclude that these TGs demonstrate cross-linking activity in AD lesions, which suggests that both TG1 and TG2 are likely involved in the protein aggregation processes underlying the formation of SPs, CAA and/or NFTs in AD brain.
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Affiliation(s)
- Micha M M Wilhelmus
- Department of Anatomy and Neurosciences, Institute for Clinical and Experimental Neurosciences, VU University Medical Center, Amsterdam, The Netherlands.
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30
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Segers-Nolten IMJ, Wilhelmus MMM, Veldhuis G, van Rooijen BD, Drukarch B, Subramaniam V. Tissue transglutaminase modulates alpha-synuclein oligomerization. Protein Sci 2008; 17:1395-402. [PMID: 18505736 DOI: 10.1110/ps.036103.108] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
We have studied the interaction of the enzyme tissue transglutaminase (tTG), catalyzing cross-link formation between protein-bound glutamine residues and primary amines, with Parkinson's disease-associated alpha-synuclein protein variants at physiologically relevant concentrations. We have, for the first time, determined binding affinities of tTG for wild-type and mutant alpha-synucleins using surface plasmon resonance approaches, revealing high-affinity nanomolar equilibrium dissociation constants. Nanomolar tTG concentrations were sufficient for complete inhibition of fibrillization by effective alpha-synuclein cross-linking, resulting predominantly in intramolecularly cross-linked monomers accompanied by an oligomeric fraction. Since oligomeric species have a pathophysiological relevance we further investigated the properties of the tTG/alpha-synuclein oligomers. Atomic force microscopy revealed morphologically similar structures for oligomers from all alpha-synuclein variants; the extent of oligomer formation was found to correlate with tTG concentration. Unlike normal alpha-synuclein oligomers the resultant structures were extremely stable and resistant to GdnHCl and SDS. In contrast to normal beta-sheet-containing oligomers, the tTG/alpha-synuclein oligomers appear to be unstructured and are unable to disrupt phospholipid vesicles. These data suggest that tTG binds equally effective to wild-type and disease mutant alpha-synuclein variants. We propose that tTG cross-linking imposes structural constraints on alpha-synuclein, preventing the assembly of structured oligomers required for disruption of membranes and for progression into fibrils. In general, cross-linking of amyloid forming proteins by tTG may prevent the progression into pathogenic species.
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Affiliation(s)
- Ine M J Segers-Nolten
- Biophysical Engineering Group, MESA+ Institute for Nanotechnology and Institute for Biomedical Technology, University of Twente, 7500 AE Enschede, The Netherlands
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31
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Hartley DM, Zhao C, Speier AC, Woodard GA, Li S, Li Z, Walz T. Transglutaminase induces protofibril-like amyloid beta-protein assemblies that are protease-resistant and inhibit long-term potentiation. J Biol Chem 2008; 283:16790-800. [PMID: 18397883 DOI: 10.1074/jbc.m802215200] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
An increasing body of evidence suggests that soluble assemblies of amyloid beta-protein (Abeta) play an important role in the initiation of Alzheimer disease (AD). In vitro studies have found that synthetic Abeta can form soluble aggregates through self-assembly, but this process requires Abeta concentrations 100- to 1000-fold greater than physiological levels. Tissue transglutaminase (TGase) has been implicated in neurodegeneration and can cross-link Abeta. Here we show that TGase induces rapid aggregation of Abeta within 0.5-30 min, which was not observed with chemical cross-linkers. Both Abeta40 and Abeta42 are good substrates for TGase but show different aggregation patterns. Guinea pig and human TGase induced similar Abeta aggregation patterns, and oligomerization was observed with Abeta40 concentrations as low as 50 nm. The formed Abeta40 species range from 5 to 6 nm spheres to curvilinear structures of the same width, but up to 100 nm in length, that resemble the previously described self-assembled Abeta protofibrils. TGase-induced Abeta40 assemblies are resistant to a 1-h incubation with either neprilysin or insulin degrading enzyme, whereas the monomer is rapidly degraded by both proteases. In support of these species being pathological, TGase-induced Abeta40 assemblies (100 nm) inhibited long term potentiation recorded in the CA1 region of mouse hippocampus slices. Our data suggest that TGase can contribute to AD by initiating Abeta oligomerization and aggregation at physiological levels, by reducing the clearance of Abeta due to the generation of protease-resistant Abeta species, and by forming Abeta assemblies that inhibit processes involved in memory and learning. Our data suggest that TGase might constitute a specific therapeutic target for slowing or blocking the progression of AD.
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Affiliation(s)
- Dean M Hartley
- Department of Neurological Sciences, Rush University Medical Center, Chicago, Illinois 60612, USA.
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32
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Wilhelmus MMM, van Dam AM, Drukarch B. Tissue transglutaminase: a novel pharmacological target in preventing toxic protein aggregation in neurodegenerative diseases. Eur J Pharmacol 2008; 585:464-72. [PMID: 18417122 DOI: 10.1016/j.ejphar.2008.01.059] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2007] [Revised: 01/10/2008] [Accepted: 01/24/2008] [Indexed: 11/30/2022]
Abstract
Alzheimer's disease, Parkinson's disease and Huntington's disease are neurodegenerative diseases, characterized by the accumulation and deposition of neurotoxic protein aggregates. The capacity of specific proteins to self-interact and form neurotoxic aggregates seems to be a common underlying mechanism leading to pathology in these neurodegenerative diseases. This process might be initiated and/or accelerated by proteins that interact with these aggregating proteins. The transglutaminase (TG) family of proteins are calcium-dependent enzymes that catalyze the formation of covalent epsilon-(gamma-glutamyl)lysine isopeptide bonds, which can result in both intra- and intermolecular cross-links. Intramolecular cross-links might modify self-interacting proteins, and make them more prone to aggregate. In addition, intermolecular cross-links could link self-aggregating proteins and thereby initiate and/or stimulate the aggregation process. So far, increased levels and activity of tissue transglutaminase (tTG), the best characterized member of the TG family, have been observed in many neurodegenerative diseases, and the self-interacting proteins, characteristic of Alzheimer's disease, Parkinson's disease and Huntington's disease, are known substrates of tTG. Here, we focus on the role of tTG in the initiation of the aggregation process of self-interacting proteins in these diseases, and promote the notion that tTG might be an attractive novel target for treatment of neurodegenerative diseases.
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Affiliation(s)
- Micha M M Wilhelmus
- Department of Anatomy and Neurosciences VU University Medical Center, Institute for Clinical and Experimental Neurosciences (ICEN), Amsterdam, The Netherlands.
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33
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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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34
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Abstract
Transglutaminase catalyzes a covalent bond between peptide-bound glutamine residues and either lysine-bound peptide residues or mono- or polyamines. Multiple lines of evidence suggest that transglutaminase is involved in neurodegenerative diseases including Alzheimer disease, progressive supranuclear palsy, Huntington disease (HD), and Parkinson disease. In all of the neurodegenerative diseases examined to date, transglutaminase enzyme activity is upregulated in selectively vulnerable brain regions, transglutaminase proteins are associated with inclusion bodies characteristic of the diseases, and prominent proteins in the inclusion bodies are modified by transglutaminase enzymes. These prominent proteins in the inclusion bodies, including tau, alpha-synuclein, and huntingtin protein, are modified by transglutaminase in vitro and alpha-synuclein and huntingtin protein are modified in cells in culture. Similar changes in transglutaminase and transglutaminase-modified proteins are replicated in transgenic mouse models of the neurodegenerative diseases, including Huntington disease and progressive supranuclear palsy. Lastly, inhibition of transglutaminase either via drug treatments or molecular approaches is beneficial for the treatment of HD transgenic mice but has yet to be explored for the other neurodegenerative diseases. Further research is needed to determine the specific role(s) that transglutaminase plays in the pathophysiology of neurodegenerative diseases with possible implications for transglutaminase as a therapeutic target.
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Affiliation(s)
- Nancy A Muma
- Department of Pharmacology, Loyola University Medical Center, Maywood, Illinois, USA.
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35
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Yamaguchi H, Wang HG. Tissue transglutaminase serves as an inhibitor of apoptosis by cross-linking caspase 3 in thapsigargin-treated cells. Mol Cell Biol 2006; 26:569-79. [PMID: 16382148 PMCID: PMC1346894 DOI: 10.1128/mcb.26.2.569-579.2006] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2005] [Revised: 06/30/2005] [Accepted: 10/18/2005] [Indexed: 11/20/2022] Open
Abstract
Thapsigargin (THG) is an inhibitor of the endoplasmic reticulum Ca2+-ATPase that induces caspase 3 activation and apoptosis in HCT116 cells through a Bax-dependent pathway. In Bax-deficient HCT116 cells, however, THG specifically generates two additional species of caspase 3, termed p40 and p64, with molecular masses of approximately 40 and 64 kDa, respectively, through unknown mechanisms. Here, we report that the Ca2+-dependent protein cross-linking enzyme tissue transglutaminase (tTGase) is involved in THG-induced p40 and p64 formation by catalyzing caspase 3 cross-linking reactions, thereby inactivating caspase 3 and apoptosis in Bax-deficient cells. Overexpression of tTGase increases p40 and p64 in THG-treated cells, and purified tTGase catalyzes procaspase 3 cross-linking in vitro. Inhibition of tTGase activity by either the tTGase inhibitor monodansylcadaverine or short-hairpin RNA reduces the cross-linked species p40 and p64 and restores caspase 3 activation in response to THG treatment. Moreover, prolonged exposure to THG results in a decrease in protein levels of XIAP and cIAP-1, which is subsequently followed by an increase in tTGase protein expression and activity. Expression of cytosolic Smac sensitizes Bax-deficient cells to THG-induced apoptosis; however, this effect is diminished by coexpression of tTGase. Taken together, these results suggest a novel role for tTGase as a new type of caspase 3 inhibitor in THG-mediated apoptosis.
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Affiliation(s)
- Hirohito Yamaguchi
- Drug Discovery Program, H. Lee Moffitt Cancer Center and Research Institute, Department of Interdisciplinary Oncology, University of South Florida, 12902 Magnolia Drive, Tampa, Florida 33612, USA
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Halverson RA, Lewis J, Frausto S, Hutton M, Muma NA. Tau protein is cross-linked by transglutaminase in P301L tau transgenic mice. J Neurosci 2005; 25:1226-33. [PMID: 15689560 PMCID: PMC6725970 DOI: 10.1523/jneurosci.3263-04.2005] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The microtubule-associated protein tau is highly soluble under physiological conditions. However, in tauopathies, tau protein aggregates into insoluble filaments and neurofibrillary tangles (NFTs). The mechanisms underlying the formation of tau filaments and NFTs in tauopathies remain unclear. Several lines of evidence suggest that transglutaminase may cross-link tau into stable, insoluble aggregates, leading to the formation of NFTs in Alzheimer's disease and progressive supranuclear palsy. To further determine the contribution of transglutaminase in the formation of NFTs, we compared the levels of cross-linked tau protein from P301L tau transgenic mice that develop NFTs to four-repeat wild-type (4RWT) tau transgenic and nontransgenic mice that do not develop NFT pathology. Immunoprecipitation and immunoblotting experiments show that transglutaminase cross-links phosphorylated tau in the hindbrain of P301L tau transgenic mice but not in mice overexpressing 4RWT tau and nontransgenic mice. Cross-linked, phosphorylated tau from P301L tau transgenic mice runs as high-molecular mass aggregates on Western blots, similar to cross-linked tau from paired helical filaments of Alzheimer's disease. We also used double-label immunofluorescence to demonstrate colocalization of PHF-1-immunoreactive tau and the transglutaminase-catalyzed cross-link in the hindbrain, spinal cord, and cortex of P301L tau transgenic mice. In the spinal cord, 87% of PHF-1-labeled cells colocalize with the transglutaminase-catalyzed cross-link. Additionally, transglutaminase enzymatic activity is significantly elevated in the spinal cord of P301L tau transgenic mice. These studies further implicate transglutaminase in the formation and/or stabilization of NFT and paired helical filaments and provide a model system to investigate the therapeutic potential of transglutaminase inhibitors in tauopathies.
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Affiliation(s)
- Robyn A Halverson
- Department of Pharmacology, Loyola University Chicago Medical Center, Maywood, Illinois 60153, USA
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Case A, Ni J, Yeh LA, Stein RL. Development of a mechanism-based assay for tissue transglutaminase—results of a high-throughput screen and discovery of inhibitors. Anal Biochem 2005; 338:237-44. [PMID: 15745743 DOI: 10.1016/j.ab.2004.09.047] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2004] [Indexed: 10/26/2022]
Abstract
Tissue transglutaminase (TGase) is a Ca(2+)-dependent enzyme that catalyzes cross-linking of intracellular proteins through a mechanism that involves isopeptide bond formation between Gln and Lys residues. In addition to its transamidation activity, TGase can bind guanosine 5'-triphosphate (GTP) and does so in a manner that is antagonized by calcium. Once bound, GTP undergoes hydrolysis to form guanosine 5'-diphosphate and inorganic phosphate. TGase is thought to play a pathogenic role in neurodegenerative diseases by promoting aggregation of disease-specific proteins that accumulate in these disorders. Thus, this enzyme represents a viable target for drug discovery. We now report the development of a mechanism-based assay for TGase and the results of a screen using this assay in which we tested 56,500 drug-like molecules for their ability to inhibit TGase. In this assay, the Gln- and Lys-donating substrates are N,N-dimethylated casein (NMC) and N-Boc-Lys-NH-CH(2)-CH(2)-NH-dansyl (KXD), respectively. Through a combination of steady state kinetic experiments and reaction progress curve simulations, we were able to calculate values for the initial concentrations of NMC, KXD, and Ca(2+) that would produce a steady state situation in which all thermodynamically significant forms of substrate-bound TGase exist in equal concentration. Under these conditions, the assay is sensitive to both competitive and mixed active-site inhibitors and to inhibitors that bind to the GTP site. The assay was optimized for automated screening in 384-well format and was then used to test our compound library. From among these compounds, 104 authentic hits that represent several mechanistic classes were identified.
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Affiliation(s)
- April Case
- Laboratory for Drug Discovery in Neurodegeneration, Harvard Center for Neurodegeneration and Repair, Cambridge, MA 02139, 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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39
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Schrödl D, Kahlenberg F, Peter-Zimmer K, Hermann W, Kühn HJ, Mothes T. Intrathecal synthesis of autoantibodies against tissue transglutaminase. J Autoimmun 2004; 22:335-40. [PMID: 15120757 DOI: 10.1016/j.jaut.2004.02.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2003] [Revised: 01/28/2004] [Accepted: 02/19/2004] [Indexed: 10/26/2022]
Abstract
Anti-tissue transglutaminase (tTG) antibodies (AtTGA) are typically found in serum of patients with untreated coeliac disease (CD). tTG catalyses crosslinking of peptides an activity supposed to be important in neurological disorders. tTG occurs in cerebrospinal fluid (CSF) and its assay in CSF was suggested to be diagnostically useful. However, nothing is known about AtTGA in CSF. Therefore, in 129 unselected CSF-serum pairs IgA- and IgG-AtTGA were assayed by ELISA using human recombinant tTG. For comparison, IgA- and IgG-anti-gliadin antibodies (AGA), typically coexisting with AtTGA were measured. Albumin, total IgA and IgG and further parameters were determined according to routine programme recommended by the European CSF consensus group. AtTGA were detected in 27 (IgA) and in 63 (IgG) CSF samples. Antibody indices (AI) could be calculated for AtTGA from 21 (IgA) and from 61 (IgG) sample pairs. AI for AtTGA was >2 in 11 (IgA) and in 22 (IgG) sample pairs, hinting to intrathecal antibody synthesis. AI for AGA was >2 only for 1 (IgA) and 2 (IgG) sample pairs. Patients with normal routine findings had significantly higher AI for IgA-AtTGA than patients with abnormal findings. This is the first demonstration of AtTGA in CSF and their intrathecal synthesis. The pathogenetic relevance of this new autoantibody species remains to be clarified.
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Affiliation(s)
- Dominik Schrödl
- Institut für Laboratoriumsmedizin, Klinische Chemie und Molekulare Diagnostik, Universitätsklinikum Leipzig, Liebigstrasse 27, D-04103 Leipzig, Germany
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40
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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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Johnson GVW, LeShoure R. Immunoblot analysis reveals that isopeptide antibodies do not specifically recognize the epsilon-(gamma-glutamyl)lysine bonds formed by transglutaminase activity. J Neurosci Methods 2004; 134:151-8. [PMID: 15003381 DOI: 10.1016/j.jneumeth.2003.11.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2003] [Revised: 11/16/2003] [Accepted: 11/21/2003] [Indexed: 10/26/2022]
Abstract
Transglutaminases (TGs) posttranslationally modify proteins by transamidation of specific polypeptide bond glutamines. This reaction results in deamination, polyamine incorporation or the formation of isopeptide bonds. Transglutaminase activity in the brain is increased in several neurodegenerative diseases. Because insoluble inclusions occur in these neurodegenerative diseases, it has been hypothesized that transglutaminase contributes to the formation of the inclusions by catalyzing the formation of isopeptide bonds resulting in crosslinked, insoluble protein aggregates. To demonstrate a role for transglutaminase in the formation of these inclusions, the primary approach has been to show increased immunoreactivity with antibodies that recognize the isopeptide bonds. However, the specificity of these antibodies for isopeptide crosslinks within or between proteins has not been clearly established. In this report we demonstrate that the two most commonly used isopeptide antibodies do not specifically recognize the isopeptide bonds formed by transglutaminase when they are within or between proteins.
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Affiliation(s)
- Gail V W Johnson
- Department of Psychiatry, School of Medicine 1720, University of Alabama at Birmingham, 7th Avenue South, SC1061, Birmingham, AL 35294-0017, USA.
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42
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Avila J, Lucas JJ, Perez M, Hernandez F. Role of tau protein in both physiological and pathological conditions. Physiol Rev 2004; 84:361-84. [PMID: 15044677 DOI: 10.1152/physrev.00024.2003] [Citation(s) in RCA: 639] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The morphology of a neuron is determined by its cytoskeletal scaffolding. Thus proteins that associate with the principal cytoskeletal components such as the microtubules have a strong influence on both the morphology and physiology of neurons. Tau is a microtubule-associated protein that stabilizes neuronal microtubules under normal physiological conditions. However, in certain pathological situations, tau protein may undergo modifications, mainly through phosphorylation, that can result in the generation of aberrant aggregates that are toxic to neurons. This process occurs in a number of neurological disorders collectively known as tauopathies, the most commonly recognized of which is Alzheimer's disease. The purpose of this review is to define the role of tau protein under normal physiological conditions and to highlight the role of the protein in different tauopathies.
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Affiliation(s)
- Jesus Avila
- Centro de Biología Molecular "Severo Ochoa", Facultad de Ciencias, Campus de Cantoblanco, Universidad Autónoma de Madrid, 28049 Madrid, Spain.
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Mattson MP, Sherman M. Perturbed signal transduction in neurodegenerative disorders involving aberrant protein aggregation. Neuromolecular Med 2004; 4:109-32. [PMID: 14528056 DOI: 10.1385/nmm:4:1-2:109] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2003] [Accepted: 06/25/2003] [Indexed: 02/04/2023]
Abstract
Aggregation of abnormal proteins, both inside and outside of cells, is a prominent feature of major neurodegenerative disorders, including Alzheimer's, Parkinson's, polyglutamine expansion, and prion diseases. Other articles in this special issue of NeuroMolecular Medicine describe the genetic and molecular factors that promote aberrant protein aggregation. In the present article, we consider how it is that pathogenic aggregation-prone proteins compromise signal transduction pathways that regulate neuronal plasticity and survival. In some cases the protein in question may have widespread and relatively nonspecific effects on signaling. For example, amyloid beta-peptide induces membrane-associated oxidative stress, which impairs the function of various receptors, ion channels and transporters, as well as downstream kinases and transcription factors. Other proteins, such as polyglutamine repeat proteins, may affect specific protein -protein interactions, including those involved in signaling pathways activated by neurotransmitters, neurotrophins, and steroid hormones. Synapses are particularly sensitive to abnormal protein aggregation and impaired synaptic signaling may trigger apoptosis and related cell death cascades. Impairment of signal transduction in protein aggregation disorders may be amenable to therapy as demonstrated by a recent study showing that dietary restriction can preserve synaptic function and protect neurons in a mouse model of Huntington's disease. Finally, emerging findings are revealing how activation of certain signaling pathways can suppress protein aggregation and/or the cytotoxicity resulting from the abnormal protein aggregation. A better understanding of how abnormal protein aggregation occurs and how it affects and is affected by specific signal transduction pathways, is leading to novel approaches for preventing and treating neurodegenerative disorders.
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Affiliation(s)
- Mark P Mattson
- Laboratory of Neurosciences, National Institute on Aging Gerontology Research Center, Baltimore, MD 21224, USA.
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44
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Abstract
Cognitive impairment and emotional disturbances in Alzheimer's disease (AD) result from the degeneration of synapses and death of neurons in the limbic system and associated regions of the cerebral cortex. An alteration in the proteolytic processing of the amyloid precursor protein (APP) results in increased production and accumulation of amyloid beta-peptide (Abeta) in the brain. Abeta has been shown to cause synaptic dysfunction and can render neurons vulnerable to excitotoxicity and apoptosis by a mechanism involving disruption of cellular calcium homeostasis. By inducing membrane lipid peroxidation and generation of the aldehyde 4-hydroxynonenal, Abeta impairs the function of membrane ion-motive ATPases and glucose and glutamate transporters, and can enhance calcium influx through voltage-dependent and ligand-gated calcium channels. Reduced levels of a secreted form of APP which normally regulates synaptic plasticity and cell survival may also promote disruption of synaptic calcium homeostasis in AD. Some cases of inherited AD are caused by mutations in presenilins 1 and 2 which perturb endoplasmic reticulum (ER) calcium homeostasis such that greater amounts of calcium are released upon stimulation, possibly as the result of alterations in IP(3) and ryanodine receptor channels, Ca(2+)-ATPases and the ER stress protein Herp. Abnormalities in calcium regulation in astrocytes, oligodendrocytes, and microglia have also been documented in studies of experimental models of AD, suggesting contributions of these alterations to neuronal dysfunction and cell death in AD. Collectively, the available data show that perturbed cellular calcium homeostasis plays a prominent role in the pathogenesis of AD, suggesting potential benefits of preventative and therapeutic strategies that stabilize cellular calcium homeostasis.
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Affiliation(s)
- Mark P Mattson
- Laboratory of Neurosciences, National Institute on Aging, Gerontology Research Center 4F01, Baltimore, MD 21224, USA.
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Mattson MP. Contributions of mitochondrial alterations, resulting from bad genes and a hostile environment, to the pathogenesis of Alzheimer's disease. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2003; 53:387-409. [PMID: 12512347 DOI: 10.1016/s0074-7742(02)53014-2] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Mark P Mattson
- Laboratory of Neurosciences, National Institute on Aging Gerontology Research Center, Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA. /gov
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46
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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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47
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Zemaitaitis MO, Kim SY, Halverson RA, Troncoso JC, Lee JM, Muma NA. Transglutaminase activity, protein, and mRNA expression are increased in progressive supranuclear palsy. J Neuropathol Exp Neurol 2003; 62:173-84. [PMID: 12578227 DOI: 10.1093/jnen/62.2.173] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Transglutaminases catalyze the covalent cross-linking of substrate proteins to form insoluble protein complexes that are resistant to degradation. Our previous studies demonstrated that transglutaminase-induced cross-linking of tau proteins occurs in Alzheimer disease and progressive supranuclear palsy (PSP). The current study was designed to measure transglutaminase enzyme activity and the mRNA and protein levels of 3 transglutaminase isoforms that are expressed in human brain. Overall, transglutaminase activity was significantly increased in the globus pallidus (182% of control) and pons in PSP (171% of control) but not the occipital cortex (a region spared from pathology). Using a Spearman rank correlation test, we found that tissues with more transglutaminase-activity had more neurofibrillary tangles. Protein and mRNA levels of transglutaminase 1 were increased in globus pallidus of PSP as compared to controls. There were also significantly higher mRNA levels of the short form of transglutaminase 2 in globus pallidus of PSP (974% of control). Transglutaminase 1 mRNA and the long isoform of transglutaminase 2 mRNA (2212% of control) were significantly higher in PSP in the dentate of cerebellum. Together, these findings suggest that transglutaminase 1 and 2 enzymes may be involved in the formation and/or stabilization of neurofibrillary tangles in selectively vulnerable brain regions in PSP. These transglutaminases may be potential targets for therapeutic intervention.
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Affiliation(s)
- Magdalena O Zemaitaitis
- Department of Pharmacology, Loyola University Stritch School of Medicine, Maywood, Illinois 60153, USA
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48
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Bonelli RM, Aschoff A, Jirikowski G. Cerebrospinal fluid tissue transglutaminase in vascular dementia. J Neurol Sci 2002; 203-204:207-9. [PMID: 12417385 DOI: 10.1016/s0022-510x(02)00292-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The enzyme tissue transglutaminase (tTG), an indicator of acute cell death, is found in brains of Alzheimer's and Huntington's disease patients. tTG, as a specific marker for apoptosis, may therefore be a powerful biochemical marker of the acute degenerating process in vivo and may be useful in discrimination between vascular dementia (VaD) and Alzheimer's disease (AD). It may serve as completion of CSF analysis in diagnosis of dementing disorders and be a simple way of assessing the efficacy of possible new anti-apoptotic drugs.
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Affiliation(s)
- Raphael M Bonelli
- Department of Neurology and Psychiatry, Hospital BHB Eggenberg, Bergstrasse 27, A-8021 Graz, Austria.
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49
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Bonelli RM, Aschoff A, Niederwieser G, Heuberger C, Jirikowski G. Cerebrospinal fluid tissue transglutaminase as a biochemical marker for Alzheimer's disease. Neurobiol Dis 2002; 11:106-10. [PMID: 12460550 DOI: 10.1006/nbdi.2002.0535] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Tissue transglutaminase (tTG) is an indicator of acute cell death in vitro. An increase in tTG protein level is found in postmortem Alzheimer's disease (AD) brains as well as in Huntington's disease. No study revealed tTG in vivo so far. We investigated the concentrations of tTG in the cerebrospinal fluid (CSF) obtained from 84 patients using ELISA assays. We compared 33 patients with probable AD to 18 patients with probable vascular dementia (VaD) and 33 control patients without neuropsychological deficit. Diagnosis was supported by CSF parameter and neuroimaging. We found a highly significant difference (P = 0.001) between the concentration of tTG in the AD groups (7.58 pg/ml) and controls (2.99 pg/ml). There was no statistical difference between controls and VaD (2.93 pg/ml). Interestingly, tTG did not show an association with tau protein, Abeta42, apoE4, neuropsychological items, or age. Males showed lower tTG values than females; however, this difference did not reach statistical significance. To our knowledge, this is the first demonstration that tTG is increased in AD in vivo. Our results suggest that tTG may be a powerful biochemical marker of the acute degenerating process in vivo. It may serve as completion of CSF analysis in the diagnosis of dementing disorders and may be a simple way of assessing the efficacy of possible new antiapoptotic drugs.
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Affiliation(s)
- Raphael M Bonelli
- Department of Neurology & Psychiatry, Hospital BHB Eggenberg, Bergstrasse 27, A-8021 Graz, Austria.
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50
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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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