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Emerson J, Delgado T, Hong M, Keillor JW, Johnson GVW. Stabilizing transglutaminase 2 in the open conformation results in reactive astrocytes being more neurosupportive. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.15.589192. [PMID: 38659783 PMCID: PMC11042235 DOI: 10.1101/2024.04.15.589192] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/26/2024]
Abstract
Astrocytes play critical roles in supporting structural and metabolic homeostasis in the central nervous system (CNS). Inflammatory conditions bring about a range of poorly understood, heterogeneous, reactive phenotypes in astrocytes. Finding ways to manipulate the phenotype of reactive astrocytes, and leveraging a pro-recovery phenotype, holds promise in treating CNS injury. Previous studies have shown that the protein transglutaminase 2 (TG2) plays a significant role in determining the phenotype of reactive astrocytes. Recently it has been demonstrated that ablation of TG2 from astrocytes improves injury outcomes both in vitro and in vivo. Excitingly, in an in vivo mouse model, pharmacological inhibition of TG2 with the irreversible inhibitor VA4 phenocopies the neurosupportive effects of TG2 deletion in astrocytes. The focus of this study was to provide insights into the mechanisms by which TG2 deletion or inhibition of TG2 with VA4 result in a more neurosupportive astrocytic phenotype. Using a neuron-astrocyte co-culture model of neurite outgrowth, we show that VA4 treatment improves the ability of astrocytes to support neurite outgrowth on an injury-relevant matrix, further validating the ability of VA4 to phenocopy astrocytic TG2 deletion. VA4 treatment of neurons alone had no effect on neurite outgrowth. VA4 covalently binds to active site residues of TG2 that are exposed in its open conformation and are critical for its enzymatic function, and prevents TG2 from taking on a closed conformation, which interferes with its protein scaffolding function. To begin to understand how pharmacologically altering TG2's conformation affects its ability to regulate reactive astrocyte phenotypes, we assayed the impact of VA4 on TG2's interaction with Zbtb7a, a transcription factor that we have previously identified as a TG2 interactor, and whose functional outputs are significantly regulated by TG2. The results of these studies demonstrated that VA4 significantly decreases the interaction of TG2 and Zbtb7a. Further, previous findings indicate that TG2 may act as an epigenetic regulator, through its nuclear protein-protein interactions, to modulate gene expression. Since both TG2 and Zbtb7a interact with members of the Sin3a chromatin repressor complex, we assayed the effect of TG2 deletion and VA4 treatment on histone acetylation and found significantly greater acetylation with TG2 deletion or inhibition with VA4. Overall, this work points toward a possible epigenetic mechanism by which genetic deletion or acute inhibition of TG2 leads to enhanced astrocytic support of neurons.
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Affiliation(s)
- Jacen Emerson
- 601 Elmwood Ave, box 604, Department of Anesthesiology and Perioperative Medicine, University of Rochester, Rochester, NY, 14620, USA
| | - Thomas Delgado
- 601 Elmwood Ave, box 604, Department of Anesthesiology and Perioperative Medicine, University of Rochester, Rochester, NY, 14620, USA
| | - Matthew Hong
- 601 Elmwood Ave, box 604, Department of Anesthesiology and Perioperative Medicine, University of Rochester, Rochester, NY, 14620, USA
| | - Jeffrey W. Keillor
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON K1N6N5, Canada
| | - Gail VW Johnson
- 601 Elmwood Ave, box 604, Department of Anesthesiology and Perioperative Medicine, University of Rochester, Rochester, NY, 14620, USA
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Emerson J, Delgado T, Girardi P, Johnson GVW. Deletion of Transglutaminase 2 from Mouse Astrocytes Significantly Improves Their Ability to Promote Neurite Outgrowth on an Inhibitory Matrix. Int J Mol Sci 2023; 24:6058. [PMID: 37047031 PMCID: PMC10094709 DOI: 10.3390/ijms24076058] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Revised: 03/01/2023] [Accepted: 03/16/2023] [Indexed: 04/14/2023] Open
Abstract
Astrocytes are the primary support cells of the central nervous system (CNS) that help maintain the energetic requirements and homeostatic environment of neurons. CNS injury causes astrocytes to take on reactive phenotypes with an altered overall function that can range from supportive to harmful for recovering neurons. The characterization of reactive astrocyte populations is a rapidly developing field, and the underlying factors and signaling pathways governing which type of reactive phenotype that astrocytes take on are poorly understood. Our previous studies suggest that transglutaminase 2 (TG2) has an important role in determining the astrocytic response to injury. Selectively deleting TG2 from astrocytes improves functional outcomes after CNS injury and causes widespread changes in gene regulation, which is associated with its nuclear localization. To begin to understand how TG2 impacts astrocytic function, we used a neuron-astrocyte co-culture paradigm to compare the effects of TG2-/- and wild-type (WT) mouse astrocytes on neurite outgrowth and synapse formation. Neurons were grown on a control substrate or an injury-simulating matrix comprised of inhibitory chondroitin sulfate proteoglycans (CSPGs). Compared to WT astrocytes, TG2-/- astrocytes supported neurite outgrowth to a significantly greater extent only on the CSPG matrix, while synapse formation assays showed mixed results depending on the pre- and post-synaptic markers analyzed. We hypothesize that TG2 regulates the supportive functions of astrocytes in injury conditions by modulating gene expression through interactions with transcription factors and transcription complexes. Based on the results of a previous yeast two-hybrid screen for TG2 interactors, we further investigated the interaction of TG2 with Zbtb7a, a ubiquitously expressed transcription factor. Co-immunoprecipitation and colocalization analyses confirmed the interaction of TG2 and Zbtb7a in the nucleus of astrocytes. Overexpression or knockdown of Zbtb7a levels in WT and TG2-/- astrocytes revealed that Zbtb7a robustly influenced astrocytic morphology and the ability of astrocytes to support neuronal outgrowth, which was significantly modulated by the presence of TG2. These findings support our hypothesis that astrocytic TG2 acts as a transcriptional regulator to influence astrocytic function, with greater influence under injury conditions that increase its expression, and Zbtb7a likely contributes to the overall effects observed with astrocytic TG2 deletion.
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Affiliation(s)
| | | | - Peter Girardi
- Department of Anesthesiology and Perioperative Medicine, University of Rochester, 601 Elmwood Ave., Box 604, Rochester, NY 14620, USA
| | - Gail V. W. Johnson
- Department of Anesthesiology and Perioperative Medicine, University of Rochester, 601 Elmwood Ave., Box 604, Rochester, NY 14620, USA
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Emerson J, Delgado T, Girardi P, Johnson GVW. Deletion of transglutaminase 2 from astrocytes significantly improves their ability to promote neurite outgrowth on an inhibitory matrix. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.06.527263. [PMID: 36798305 PMCID: PMC9934526 DOI: 10.1101/2023.02.06.527263] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Astrocytes are the primary support cells of the central nervous system (CNS) that help maintain the energetic requirements and homeostatic environment of neurons. CNS injury causes astrocytes to take on reactive phenotypes with altered overall function that can range from supportive to harmful for recovering neurons. The characterization of reactive astrocyte populations is a rapidly developing field, and the underlying factors and signaling pathways governing which type of reactive phenotype that astrocytes take on is poorly understood. Our previous studies suggest that transglutaminase 2 (TG2) has an important role in determining the astrocytic response to injury. TG2 is upregulated in astrocytes across multiple injury models, and selectively deleting TG2 from astrocytes improves functional outcomes after CNS injury and causes widespread changes in gene regulation, which is associated with its nuclear localization. The underlying molecular mechanisms by which TG2 causes these functional changes are unknown, and its interactions in the nucleus of astrocytes has not yet been described. To begin to understand how TG2 impacts astrocytic function, we used a neuron-astrocyte co-culture paradigm to compare the effects of TG2-/- and wild type (WT) astrocytes on neurite outgrowth and synapse formation. We assayed neurons on both a growth-supportive substrate and an injury-simulating matrix comprised of inhibitory chondroitin sulfate proteoglycans (CSPGs). Compared to WT astrocytes, TG2-/- astrocytes supported neurite outgrowth to a significantly greater extent only on the CSPG matrix, while synapse formation assays showed mixed results depending on the pre- and post-synaptic markers analyzed. We hypothesize that TG2 regulates the supportive functions of astrocytes in injury conditions by modulating the expression of a wide range of genes through interactions with transcription factors and transcription complexes. Based on results of a previous yeast two-hybrid screen for TG2 interactors, we further investigated the interaction of TG2 with Zbtb7a, a ubiquitously expressed transcription factor. Coimmunoprecipitation and colocalization analyses confirmed the interaction of TG2 and Zbtb7a in the nucleus of astrocytes. Genetic overexpression or knockdown of Zbtb7a levels in TG2-/- and WT astrocytes revealed that Zbtb7a robustly influenced astrocytic morphology and the ability of astrocytes to support neuronal outgrowth, which was significantly modulated by the presence of TG2. These findings support our hypothesis that astrocytic TG2 acts as a transcriptional regulator to influence astrocytic function, with greater influence under injury conditions that increase its expression, and Zbtb7a likely contributes to the overall effects observed with astrocytic TG2 deletion.
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Affiliation(s)
- Jacen Emerson
- 601 Elmwood Ave, Box 604, Department of Anesthesiology and Perioperative Medicine, University of Rochester, Rochester, NY 14620, USA
| | - Thomas Delgado
- 601 Elmwood Ave, Box 604, Department of Anesthesiology and Perioperative Medicine, University of Rochester, Rochester, NY 14620, USA
| | - Peter Girardi
- 601 Elmwood Ave, Box 604, Department of Anesthesiology and Perioperative Medicine, University of Rochester, Rochester, NY 14620, USA
| | - Gail VW Johnson
- 601 Elmwood Ave, Box 604, Department of Anesthesiology and Perioperative Medicine, University of Rochester, Rochester, NY 14620, USA,Correspondence: ; Tel.: +1-585-276-3740
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Samra M, Srivastava K. Non-coding RNA and their potential role in cardiovascular diseases. Gene 2023; 851:147011. [DOI: 10.1016/j.gene.2022.147011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Revised: 09/27/2022] [Accepted: 10/21/2022] [Indexed: 11/27/2022]
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Tonoli E, Verduci I, Gabrielli M, Prada I, Forcaia G, Coveney C, Savoca MP, Boocock DJ, Sancini G, Mazzanti M, Verderio C, Verderio EAM. Extracellular transglutaminase-2, nude or associated with astrocytic extracellular vesicles, modulates neuronal calcium homeostasis. Prog Neurobiol 2022; 216:102313. [PMID: 35760142 DOI: 10.1016/j.pneurobio.2022.102313] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 06/15/2022] [Accepted: 06/22/2022] [Indexed: 01/12/2023]
Abstract
We have uncovered a novel role for astrocytes-derived extracellular vesicles (EVs) in controlling intraneuronal Ca2+ concentration ([Ca2+]i) and identified transglutaminase-2 (TG2) as a surface-cargo of astrocytes-derived EVs. Incubation of hippocampal neurons with primed astrocyte-derived EVs have led to an increase in [Ca2+]i, unlike EVs from TG2-knockout astrocytes. Exposure of neurons or brain slices to extracellular TG2 promoted a [Ca2+]i rise, which was reversible upon TG2 removal and was dependent on Ca2+ influx through the plasma membrane. Patch-clamp and calcium imaging recordings revealed TG2-dependent neuronal membrane depolarization and activation of inward currents, due to the Na+/Ca2+-exchanger (NCX) operating in the reverse mode and indirect activation of L-type VOCCs, as indicated by VOCCs/NCX pharmacological inhibitors. A subunit of Na+/K+-ATPase was selected by comparative proteomics and identified as being functionally inhibited by extracellular TG2, implicating Na+/K+-ATPase inhibition in NCX reverse mode-switching leading to Ca2+ influx and higher basal [Ca2+]i. These data suggest that reactive astrocytes control intraneuronal [Ca2+]i through release of EVs with TG2 as responsible cargo, which could have a significant impact on synaptic activity in brain inflammation.
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Affiliation(s)
- Elisa Tonoli
- School of Science and Technology, Centre for Health, Ageing and Understanding of Disease, Nottingham Trent University, Nottingham NG11 8NS, United Kingdom
| | - Ivan Verduci
- Department of Bioscience, University of Milan, Milano 20133, Italy
| | | | - Ilaria Prada
- CNR Institute of Neuroscience, Vedano al Lambro 20854, Italy
| | - Greta Forcaia
- Human Physiology Lab., School of Medicine and Surgery, University of Milano-Bicocca, Monza 20900, Italy
| | - Clare Coveney
- School of Science and Technology, The John van Geest Cancer Research Centre, Nottingham Trent University, Nottingham NG11 8NS, United Kingdom
| | - Maria Pia Savoca
- School of Science and Technology, Centre for Health, Ageing and Understanding of Disease, Nottingham Trent University, Nottingham NG11 8NS, United Kingdom
| | - David J Boocock
- School of Science and Technology, The John van Geest Cancer Research Centre, Nottingham Trent University, Nottingham NG11 8NS, United Kingdom
| | - Giulio Sancini
- Human Physiology Lab., School of Medicine and Surgery, University of Milano-Bicocca, Monza 20900, Italy; NeuroMI (Milan Center for Neuroscience), School of Medicine and Surgery, University of Milano-Bicocca, Monza 20900, Italy
| | - Michele Mazzanti
- Department of Bioscience, University of Milan, Milano 20133, Italy
| | - Claudia Verderio
- CNR Institute of Neuroscience, Vedano al Lambro 20854, Italy; NeuroMI (Milan Center for Neuroscience), School of Medicine and Surgery, University of Milano-Bicocca, Monza 20900, Italy.
| | - Elisabetta A M Verderio
- School of Science and Technology, Centre for Health, Ageing and Understanding of Disease, Nottingham Trent University, Nottingham NG11 8NS, United Kingdom; Biological Sciences Department (BiGeA), University of Bologna, Bologna 40126, Italy.
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Elahi A, Emerson J, Rudlong J, Keillor JW, Salois G, Visca A, Girardi P, Johnson GV, Pröschel C. Deletion or Inhibition of Astrocytic Transglutaminase 2 Promotes Functional Recovery after Spinal Cord Injury. Cells 2021; 10:2942. [PMID: 34831164 PMCID: PMC8616117 DOI: 10.3390/cells10112942] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 10/20/2021] [Accepted: 10/21/2021] [Indexed: 01/23/2023] Open
Abstract
Following CNS injury, astrocytes become "reactive" and exhibit pro-regenerative or harmful properties. However, the molecular mechanisms that cause astrocytes to adopt either phenotype are not well understood. Transglutaminase 2 (TG2) plays a key role in regulating the response of astrocytes to insults. Here, we used mice in which TG2 was specifically deleted in astrocytes (Gfap-Cre+/- TG2fl/fl, referred to here as TG2-A-cKO) in a spinal cord contusion injury (SCI) model. Deletion of TG2 from astrocytes resulted in a significant improvement in motor function following SCI. GFAP and NG2 immunoreactivity, as well as number of SOX9 positive cells, were significantly reduced in TG2-A-cKO mice. RNA-seq analysis of spinal cords from TG2-A-cKO and control mice 3 days post-injury identified thirty-seven differentially expressed genes, all of which were increased in TG2-A-cKO mice. Pathway analysis revealed a prevalence for fatty acid metabolism, lipid storage and energy pathways, which play essential roles in neuron-astrocyte metabolic coupling. Excitingly, treatment of wild type mice with the selective TG2 inhibitor VA4 significantly improved functional recovery after SCI, similar to what was observed using the genetic model. These findings indicate the use of TG2 inhibitors as a novel strategy for the treatment of SCI and other CNS injuries.
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Affiliation(s)
- Anissa Elahi
- Department of Biomedical Genetics, University of Rochester, Rochester, NY 14620, USA; (A.E.); (G.S.); (A.V.); (C.P.)
| | - Jacen Emerson
- Department of Anesthesiology and Perioperative Medicine, University of Rochester, Rochester, NY 14620, USA; (J.E.); (J.R.); (P.G.)
| | - Jacob Rudlong
- Department of Anesthesiology and Perioperative Medicine, University of Rochester, Rochester, NY 14620, USA; (J.E.); (J.R.); (P.G.)
| | - Jeffrey W. Keillor
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON K1N 6N5, Canada;
| | - Garrick Salois
- Department of Biomedical Genetics, University of Rochester, Rochester, NY 14620, USA; (A.E.); (G.S.); (A.V.); (C.P.)
| | - Adam Visca
- Department of Biomedical Genetics, University of Rochester, Rochester, NY 14620, USA; (A.E.); (G.S.); (A.V.); (C.P.)
| | - Peter Girardi
- Department of Anesthesiology and Perioperative Medicine, University of Rochester, Rochester, NY 14620, USA; (J.E.); (J.R.); (P.G.)
| | - Gail V.W. Johnson
- Department of Anesthesiology and Perioperative Medicine, University of Rochester, Rochester, NY 14620, USA; (J.E.); (J.R.); (P.G.)
| | - Christoph Pröschel
- Department of Biomedical Genetics, University of Rochester, Rochester, NY 14620, USA; (A.E.); (G.S.); (A.V.); (C.P.)
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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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Llorente IL, Xie Y, Mazzitelli JA, Hatanaka EA, Cinkornpumin J, Miller DR, Lin Y, Lowry WE, Carmichael ST. Patient-derived glial enriched progenitors repair functional deficits due to white matter stroke and vascular dementia in rodents. Sci Transl Med 2021; 13:13/590/eaaz6747. [PMID: 33883275 DOI: 10.1126/scitranslmed.aaz6747] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 10/05/2020] [Accepted: 01/16/2021] [Indexed: 01/24/2023]
Abstract
Subcortical white matter stroke (WMS) accounts for up to 30% of all stroke events. WMS damages primarily astrocytes, axons, oligodendrocytes, and myelin. We hypothesized that a therapeutic intervention targeting astrocytes would be ideally suited for brain repair after WMS. We characterize the cellular properties and in vivo tissue repair activity of glial enriched progenitor (GEP) cells differentiated from human-induced pluripotent stem cells, termed hiPSC-derived GEPs (hiPSC-GEPs). hiPSC-GEPs are derived from hiPSC-neural progenitor cells via an experimental manipulation of hypoxia inducible factor activity by brief treatment with a prolyl hydroxylase inhibitor, deferoxamine. This treatment permanently biases these cells to further differentiate toward an astrocyte fate. hiPSC-GEPs transplanted into the brain in the subacute period after WMS in mice migrated widely, matured into astrocytes with a prorepair phenotype, induced endogenous oligodendrocyte precursor proliferation and remyelination, and promoted axonal sprouting. hiPSC-GEPs enhanced motor and cognitive recovery compared to other hiPSC-differentiated cell types. This approach establishes an hiPSC-derived product with easy scale-up capabilities that might be effective for treating WMS.
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Affiliation(s)
- Irene L Llorente
- Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| | - Yuan Xie
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL 60637, USA
| | - Jose A Mazzitelli
- Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| | - Emily A Hatanaka
- Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA.,Department of Molecular, Cell and Developmental Biology, UCLA, Los Angeles, CA 90095, USA
| | - Jessica Cinkornpumin
- Department of Molecular, Cell and Developmental Biology, UCLA, Los Angeles, CA 90095, USA
| | - David R Miller
- Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| | - Ying Lin
- Department of Molecular, Cell and Developmental Biology, UCLA, Los Angeles, CA 90095, USA
| | - William E Lowry
- Department of Molecular, Cell and Developmental Biology, UCLA, Los Angeles, CA 90095, USA.
| | - S Thomas Carmichael
- Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA.
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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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Rudlong J, Cheng A, Johnson GVW. The role of transglutaminase 2 in mediating glial cell function and pathophysiology in the central nervous system. Anal Biochem 2019; 591:113556. [PMID: 31866289 DOI: 10.1016/j.ab.2019.113556] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Revised: 12/04/2019] [Accepted: 12/18/2019] [Indexed: 12/13/2022]
Abstract
The ubiquitously expressed transglutaminase 2 (TG2) has diverse functions in virtually all cell types, with its role depending not only on cell type, but also on specific subcellular localization. In the central nervous system (CNS) different types of glial cells, such as astrocytes, microglia, and oligodendrocytes and their precursor cells (OPCs), play pivotal supportive functions. This review is focused on what is currently known about the role of TG2 in each type of glial cell, in the context of normal function and pathophysiology. For example, astrocytic TG2 facilitates their migration and proliferation, but hinders their ability to protect neurons after CNS injury. The review also examines the interactions between glial cell types, and how TG2 in one cell type may affect another, as well as implications for specific TG2 populations as therapeutic targets in CNS pathology.
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Affiliation(s)
- Jacob Rudlong
- Department of Anesthesiology and Perioperative Medicine and the Neuroscience Graduate Program, University of Rochester, Rochester, NY, 14620, USA
| | - Anson Cheng
- Department of Anesthesiology and Perioperative Medicine and the Neuroscience Graduate Program, University of Rochester, Rochester, NY, 14620, USA
| | - Gail V W Johnson
- Department of Anesthesiology and Perioperative Medicine and the Neuroscience Graduate Program, University of Rochester, Rochester, NY, 14620, USA.
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11
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Transglutaminases, neuronal cell death and neural repair: implications for traumatic brain injury and therapeutics. Curr Opin Neurol 2019; 32:796-801. [DOI: 10.1097/wco.0000000000000753] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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12
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Ji C, Tang M, Harrison J, Paciorkowski A, Johnson GVW. Nuclear transglutaminase 2 directly regulates expression of cathepsin S in rat cortical neurons. Eur J Neurosci 2018; 48:3043-3051. [PMID: 30239049 DOI: 10.1111/ejn.14159] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Revised: 08/14/2018] [Accepted: 08/28/2018] [Indexed: 01/06/2023]
Abstract
Transglutaminase 2 (TG2) is a protein that modulates neuronal survival processes. Although TG2 is primarily cytosolic, data have suggested the nuclear localization of TG2 is strongly associated with neuronal viability. Depletion of TG2 in neurons results in neurite retraction and loss of viability, which is likely due to a dysregulation in gene expression. To begin to understand how TG2 regulates neuronal gene expression, chromatin immunoprecipitation was performed in neurons with TG2 overexpression. The resulting genomic DNA was recovered and sequenced. Bioinformatics analyses revealed that a signature DNA motif was enriched in the TG2 immunoprecipitated genomic DNA. In particular, this motif strongly mapped to a region proximate to the gene Ctss (cathepsin S). Knockdown of TG2 resulted in a significant increase in cathepsin S expression, which preceded the loss of neuronal viability. This is the first demonstration that TG2 directly associates with genomic DNA and regulates gene expression in neurons. Given that expression of cathepsin S is increased in neurological disease states, our data suggest that TG2 may play a role in promoting neuron health in part by repressing the expression of cathepsin S. Overall these data provide new insights into the function of nuclear TG2 in neurons.
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Affiliation(s)
- Changyi Ji
- Department of Anesthesiology and Perioperative Medicine, University of Rochester, Rochester, New York
| | - Maoping Tang
- Department of Anesthesiology and Perioperative Medicine, University of Rochester, Rochester, New York
| | - Jarreau Harrison
- Department of Pharmacology and Physiology, University of Rochester, Rochester, New York
| | - Alex Paciorkowski
- Departments of Neurology, Pediatrics, Biomedical Genetics, and Neuroscience, University of Rochester Medical Center, Rochester, New York.,Del Monte Institute for Neuroscience, University of Rochester, Rochester, New York
| | - Gail V W Johnson
- Department of Anesthesiology and Perioperative Medicine, University of Rochester, Rochester, New York.,Department of Pharmacology and Physiology, University of Rochester, Rochester, New York.,Del Monte Institute for Neuroscience, University of Rochester, Rochester, New York
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13
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Monteagudo A, Feola J, Natola H, Ji C, Pröschel C, Johnson GVW. Depletion of astrocytic transglutaminase 2 improves injury outcomes. Mol Cell Neurosci 2018; 92:128-136. [PMID: 29969654 DOI: 10.1016/j.mcn.2018.06.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Revised: 06/26/2018] [Accepted: 06/27/2018] [Indexed: 01/12/2023] Open
Abstract
Astrocytes play an indispensable role in maintaining a healthy, functional neural network in the central nervous system (CNS). A primary function of CNS astrocytes is to support the survival and function of neurons. In response to injury, astrocytes take on a reactive phenotype, which alters their molecular functions. Reactive astrocytes have been reported to be both beneficial and harmful to the CNS recovery process subsequent to injury. Understanding the molecular processes and regulatory proteins that determine the extent to which an astrocyte hinders or supports neuronal survival is important within the context of CNS repair. One protein that plays a role in modulating cellular survival is transglutaminase 2 (TG2). Global deletion of TG2 results in beneficial outcomes subsequent to in vivo ischemic brain injury. Ex vivo studies have also implicated TG2 as a negative regulator of astrocyte viability subsequent to injury. In this study we show that knocking down TG2 in astrocytes significantly increases their ability to protect neurons from oxygen glucose deprivation (OGD)/reperfusion injury. To begin to understand how deletion of TG2 in astrocytes improves their ability to protect neurons from injury, we performed transcriptome analysis of wild type and TG2-/- astrocytes. TG2 deletion resulted in alterations in genes involved in extracellular matrix remodeling, cell adhesion and axon growth/guidance. In addition, the majority of genes that showed increases in the TG2-/- astrocytes had predicted cJun/AP-1 binding motifs in their promoters. Furthermore, phospho-cJun levels were robustly elevated in TG2-/- astrocytes, a finding which was consistent with the increase in expression of AP-1 responsive genes. These in vitro data were subsequently extended into an in vivo model to determine whether the absence of astrocytic TG2 improves outcomes after CNS injury. Our results show that, following a spinal cord injury, scar formation is significantly attenuated in mice with astrocyte-specific TG2 deletion compared to mice expressing normal TG2 levels. Taken together, these data indicate that TG2 plays a pivotal role in mediating reactive astrocyte properties following CNS injury. Further, the data suggest that limiting the AP-1 mediated pro-survival injury response may be a contributing factor to that the detrimental effects of astrocytic TG2.
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Affiliation(s)
- Alina Monteagudo
- Department of Pharmacology and Physiology, University of Rochester, Rochester, NY 14642, USA
| | - Julianne Feola
- Department of Biomedical Genetics, University of Rochester, Rochester, NY 14642, USA
| | - Heather Natola
- Department of Biomedical Genetics, University of Rochester, Rochester, NY 14642, USA
| | - Changyi Ji
- Department of Anesthesiology and Perioperative Medicine, University of Rochester, Rochester, NY 14642, USA
| | - Christoph Pröschel
- Department of Biomedical Genetics, University of Rochester, Rochester, NY 14642, USA; Stem Cell and Regenerative Medicine Institute, University of Rochester, Rochester, NY 14642, USA
| | - Gail V W Johnson
- Department of Pharmacology and Physiology, University of Rochester, Rochester, NY 14642, USA; Department of Biomedical Genetics, University of Rochester, Rochester, NY 14642, USA; Department of Anesthesiology and Perioperative Medicine, University of Rochester, Rochester, NY 14642, USA.
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14
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Subcellular localization patterns of transglutaminase 2 in astrocytes and neurons are differentially altered by hypoxia. Neuroreport 2018; 28:1208-1214. [PMID: 28957946 DOI: 10.1097/wnr.0000000000000895] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The multifunctional protein transglutaminase 2 (TG2) has been widely implicated as a modulator of cellular viability. Specifically, TG2 expression is beneficial to neuronal survival following an ischemic injury, whereas the opposite is true in astrocytes. Furthermore, its role in mediating cell death and survival processes has been suggested to be dependent on its subcellular localization. Therefore, the aim of this study was to examine the subcellular localization patterns of neuronal and astrocytic TG2 in ischemia-relevant conditions. We found that nuclear levels of TG2 were significantly increased in neurons, but reduced in astrocytes, in response to hypoxia. In addition, there were no changes in extracellular TG2 in astrocytes exposed to hypoxia. Thus, these findings demonstrate a difference in the subcellular localization pattern of TG2 in neurons and astrocytes in ischemia-relevant conditions and provide further avenues for investigation into the role of TG2 in mediating cellular viability.
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15
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Quinn BR, Yunes-Medina L, Johnson GVW. Transglutaminase 2: Friend or foe? The discordant role in neurons and astrocytes. J Neurosci Res 2018; 96:1150-1158. [PMID: 29570839 DOI: 10.1002/jnr.24239] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Revised: 03/01/2018] [Accepted: 03/12/2018] [Indexed: 12/19/2022]
Abstract
Members of the transglutaminase family catalyze the formation of isopeptide bonds between a polypeptide-bound glutamine and a low molecular weight amine (e.g., spermidine) or the ɛ-amino group of a polypeptide-bound lysine. Transglutaminase 2 (TG2), a prominent member of this family, is unique because in addition to being a transamidating enzyme, it exhibits numerous other activities. As a result, TG2 plays a role in many physiological processes, and its function is highly cell type specific and relies upon a number of factors, including conformation, cellular compartment location, and local concentrations of Ca2+ and guanine nucleotides. TG2 is the most abundant transglutaminase in the central nervous system (CNS) and plays a pivotal role in the CNS injury response. How TG2 affects the cell in response to an insult is strikingly different in astrocytes and neurons. In neurons, TG2 supports survival. Overexpression of TG2 in primary neurons protects against oxygen and glucose deprivation (OGD)-induced cell death and in vivo results in a reduction in infarct volume subsequent to a stroke. Knockdown of TG2 in primary neurons results in a loss of viability. In contrast, deletion of TG2 from astrocytes results in increased survival following OGD and improved ability to protect neurons from injury. Here, a brief overview of TG2 is provided, followed by a discussion of the role of TG2 in transcriptional regulation, cellular dynamics, and cell death. The differing roles TG2 plays in neurons and astrocytes are highlighted and compared to how TG2 functions in other cell types.
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Affiliation(s)
- Breandan R Quinn
- Department of Pharmacology and Physiology, University of Rochester, Rochester, New York
| | - Laura Yunes-Medina
- Department of Neuroscience, University of Rochester, Rochester, New York
| | - Gail V W Johnson
- Department of Pharmacology and Physiology, University of Rochester, Rochester, New York.,Department of Neuroscience, University of Rochester, Rochester, New York.,Department of Anesthesiology and Perioperative Medicine, University of Rochester, Rochester, New York
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16
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Yunes-Medina L, Paciorkowski A, Nuzbrokh Y, Johnson GVW. Depletion of transglutaminase 2 in neurons alters expression of extracellular matrix and signal transduction genes and compromises cell viability. Mol Cell Neurosci 2018; 86:72-80. [PMID: 29197584 PMCID: PMC5736014 DOI: 10.1016/j.mcn.2017.11.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Revised: 10/20/2017] [Accepted: 11/21/2017] [Indexed: 12/22/2022] Open
Abstract
The protein transglutaminase 2 (TG2) has been implicated as a modulator of neuronal viability. TG2's role in mediating cell survival processes has been suggested to involve its ability to alter transcriptional events. The goal of this study was to examine the role of TG2 in neuronal survival and to begin to delineate the pathways it regulates. We show that depletion of TG2 significantly compromises the viability of neurons in the absence of any stressors. RNA sequencing revealed that depletion of TG2 dysregulated the expression of 86 genes with 59 of these being upregulated. The genes that were upregulated by TG2 knockdown were primarily involved in extracellular matrix function, cell signaling and cytoskeleton integrity pathways. Finally, depletion of TG2 significantly reduced neurite length. These findings suggest for the first time that TG2 plays a crucial role in mediating neuronal survival through its regulation of genes involved in neurite length and maintenance.
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Affiliation(s)
- Laura Yunes-Medina
- Department of Neuroscience, University of Rochester, 601 Elmwood Ave, Box 603, Rochester, NY 14642, United States.
| | - Alex Paciorkowski
- Department of Neuroscience, University of Rochester, 601 Elmwood Ave, Box 603, Rochester, NY 14642, United States; Department of Neurology, University of Rochester, 601 Elmwood Ave, Box 603, Rochester, NY 14642, United States; Department of Pediatrics, University of Rochester Medical Center, 601 Elmwood Ave, Box 603, Rochester, NY 14642, United States; Department Biomedical Genetics, University of Rochester Medical Center, 601 Elmwood Ave, Box 604, Rochester, NY 14642, United States.
| | - Yan Nuzbrokh
- Department of Anesthesiology and Perioperative Medicine, University of Rochester Medical Center, 601 Elmwood Ave, Box 604, Rochester, NY 14642, United States.
| | - Gail V W Johnson
- Department of Anesthesiology and Perioperative Medicine, University of Rochester Medical Center, 601 Elmwood Ave, Box 604, Rochester, NY 14642, United States; Department of Pharmacology and Physiology, University of Rochester Medical Center, 601 Elmwood Ave, Box 604, Rochester, NY 14642, United States.
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17
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Transglutaminase 2 modulation of NF-κB signaling in astrocytes is independent of its ability to mediate astrocytic viability in ischemic injury. Brain Res 2017; 1668:1-11. [PMID: 28522262 DOI: 10.1016/j.brainres.2017.05.009] [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: 12/16/2016] [Revised: 04/14/2017] [Accepted: 05/10/2017] [Indexed: 12/20/2022]
Abstract
Transglutaminase 2 (TG2) is a multifunctional protein that can contribute to cell death and cell survival processes in a variety of disease contexts. Within the brain, TG2 has been shown to promote cell death in ischemic injury when expressed in astrocytes (Colak and Johnson, 2012). However, the specific functions and characteristics of astrocytic TG2 that mediate this effect are largely unknown. Therefore, the goal of this study was to investigate the role of astrocytic TG2 in mediating cellular viability processes in the context of ischemic injury, with a specific focus on its contributions to intracellular signaling cascades. We show that, in response to oxygen/glucose deprivation (OGD), acute lentiviral-mediated knockdown of TG2, as well as inhibition with an irreversible TG2 inhibitor, enhances cell survival. We also show that TG2 depletion increases nuclear factor-κB (NF-κB) signaling, whereas inhibition reduces NF-κB activity. Despite its clear contribution to NF-κB signaling, however, TG2 modulation of NF-κB signaling is not likely to be a major contributor to its ability to mediate astrocytic viability in this context. Overall, the results of this study provide insight into the role of TG2 in astrocytes and suggest possible avenues for future study of the relationship between astrocytic TG2 and ischemic injury.
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18
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Gundemir S, Monteagudo A, Akbar A, Keillor JW, Johnson GVW. The complex role of transglutaminase 2 in glioblastoma proliferation. Neuro Oncol 2017; 19:208-218. [PMID: 27591334 PMCID: PMC5464277 DOI: 10.1093/neuonc/now157] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Glioblastomas (GBMs) are a heterogeneous group of primary brain tumors. These tumors are resistant to therapeutic interventions and invariably recur after surgical resection. The multifunctional protein transglutaminase 2 (TG2) has been shown to promote cell survival in a number of different tumors. There is also evidence that TG2 may be a pro-survival factor in GBMs. However, the roles that TG2 plays in facilitating GBM survival and proliferation have not yet been clearly delineated . METHODS The functions of TG2 are often cell- and context-specific. Therefore, in this study we examined the ability of TG2 to facilitate GBM proliferation using colony formation assays and 5-ethynyl-2'-deoxyuridine (EdU) incorporation in several different GBM cell lines as well as neurospheres derived from patient tumors representing the 3 major subtypes of GBM tumors (mesenchymal, proneural, and classical) and maintained in the absence of serum. TG2 knockdown or selective TG2 inhibitors were used to modulate TG2 expression and activity. RESULTS We show that TG2 plays differential roles in the proliferative process depending on the cell type. In most, but not all, GBM models TG2 plays a crucial role in the proliferative process, and some but not all TG2 inhibitors were highly effective at reducing proliferation in a large subset of the GBM models. CONCLUSION Our results show that TG2 plays an important-but notoriously context-specific-role in GBM cell biology. Nonetheless, as future studies unravel the genetic "fingerprints" that make TG2 inhibitors effective, this information could be exploited to develop TG2 inhibitors into personalized GBM therapies.
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Affiliation(s)
- Soner Gundemir
- Department of Anesthesiology, University of Rochester, Rochester, New York; Department of Pharmacology and Physiology, University of Rochester, Rochester, New York; Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, Ontario, Canada
| | - Alina Monteagudo
- Department of Anesthesiology, University of Rochester, Rochester, New York; Department of Pharmacology and Physiology, University of Rochester, Rochester, New York; Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, Ontario, Canada
| | - Abdullah Akbar
- Department of Anesthesiology, University of Rochester, Rochester, New York; Department of Pharmacology and Physiology, University of Rochester, Rochester, New York; Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, Ontario, Canada
| | - Jeffrey W Keillor
- Department of Anesthesiology, University of Rochester, Rochester, New York; Department of Pharmacology and Physiology, University of Rochester, Rochester, New York; Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, Ontario, Canada
| | - Gail V W Johnson
- Department of Anesthesiology, University of Rochester, Rochester, New York; Department of Pharmacology and Physiology, University of Rochester, Rochester, New York; Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, Ontario, Canada
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19
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Monteagudo A, Ji C, Akbar A, Keillor JW, Johnson GVW. Inhibition or ablation of transglutaminase 2 impairs astrocyte migration. Biochem Biophys Res Commun 2016; 482:942-947. [PMID: 27899316 DOI: 10.1016/j.bbrc.2016.11.137] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Accepted: 11/25/2016] [Indexed: 12/11/2022]
Abstract
Astrocytes play numerous complex roles that support and facilitate the function of neurons. Further, when there is an injury to the central nervous system (CNS) they can both facilitate or ameliorate functional recovery depending on the location and severity of the injury. When a CNS injury is relatively severe a glial scar is formed, which is primarily composed of astrocytes. The glial scar can be both beneficial, by limiting inflammation, and detrimental, by preventing neuronal projections, to functional recovery. Thus, understanding the processes and proteins that regulate astrocyte migration in response to injury is still of fundamental importance. One protein that is likely involved in astrocyte migration is transglutaminase 2 (TG2); a multifunctional protein expressed ubiquitously throughout the brain. Its functions include transamidation and GTPase activity, among others, and previous studies have implicated TG2 as a regulator of migration. Therefore, we examined the role of TG2 in primary astrocyte migration subsequent to injury. Using wild type or TG2-/- astrocytes, we manipulated the different functions and conformation of TG2 with novel irreversible inhibitors or mutant versions of the protein. Results showed that both inhibition and ablation of TG2 in primary astrocytes significantly inhibit migration. Additionally, we show that the deficiency in migration caused by deletion of TG2 can only be rescued with the native protein and not with mutants. Finally, the addition of TGFβ rescued the migration deficiency independent of TG2. Taken together, our study shows that transamidation and GTP/GDP-binding are necessary for inhibiting astrocyte migration and it is TGFβ independent.
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Affiliation(s)
- Alina Monteagudo
- Department of Pharmacology and Physiology, University of Rochester, Rochester, NY 14642, USA
| | - Changyi Ji
- Department of Anesthesiology, University of Rochester, Rochester, NY 14642, USA
| | - Abdullah Akbar
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON K1N 6N5, Canada
| | - Jeffrey W Keillor
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON K1N 6N5, Canada
| | - Gail V W Johnson
- Department of Pharmacology and Physiology, University of Rochester, Rochester, NY 14642, USA; Department of Anesthesiology, University of Rochester, Rochester, NY 14642, USA.
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20
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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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21
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Lin CHS, Chen J, Zhang Z, Johnson GVW, Cooper AJL, Feola J, Bank A, Shein J, Ruotsalainen HJ, Pihlajaniemi TA, Goligorsky MS. Endostatin and transglutaminase 2 are involved in fibrosis of the aging kidney. Kidney Int 2016; 89:1281-92. [PMID: 27165830 DOI: 10.1016/j.kint.2016.01.030] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Revised: 01/25/2016] [Accepted: 01/28/2016] [Indexed: 12/21/2022]
Abstract
Endostatin (EST), an antiangiogenic factor, is enriched in aging kidneys. EST is also an interactive partner of transglutaminase 2 (TG2), an enzyme that cross-links extracellular matrix proteins. Here we tested whether EST and TG2 play a role in the fibrosis of aging. In wild-type mice, aging kidneys exhibited a 2- to 4-fold increase in TG2 paralleled by increased cross-linked extracellular matrix proteins and fibrosis. Mice transgenic to express EST showed renal fibrosis at a young age. One-month delivery of EST via minipumps to young mice showed increased renal fibrosis that became more robust when superimposed on folic acid-induced nephropathy. Upregulated TG2 and impaired renal function were apparent with EST delivery combined with folic acid-induced nephropathy. Subcapsular injection of TG2 and/or EST into kidneys of young mice not only induced interstitial fibrosis, but also increased the proportion of senescent cells. Thus, kidney fibrosis in aging may represent a natural outcome of upregulated EST and TG2, but more likely it appears to be a result of cumulative stresses occurring on the background of synergistically acting geronic (aging) proteins, EST and TG2.
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Affiliation(s)
- Chi Hua Sarah Lin
- Department of Medicine, Renal Research Institute, New York Medical College, Valhalla, New York, USA; Department of Pharmacology, Renal Research Institute, New York Medical College, Valhalla, New York, USA; Department of Physiology, Renal Research Institute, New York Medical College, Valhalla, New York, USA
| | - Jun Chen
- Department of Medicine, Renal Research Institute, New York Medical College, Valhalla, New York, USA; Department of Pharmacology, Renal Research Institute, New York Medical College, Valhalla, New York, USA; Department of Physiology, Renal Research Institute, New York Medical College, Valhalla, New York, USA
| | - Zhongtao Zhang
- Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, New York, USA
| | - Gail V W Johnson
- Department of Anesthesiology, University of Rochester, Rochester, New York, USA
| | - Arthur J L Cooper
- Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, New York, USA
| | - Julianne Feola
- Department of Anesthesiology, University of Rochester, Rochester, New York, USA
| | - Alexander Bank
- Department of Medicine, Renal Research Institute, New York Medical College, Valhalla, New York, USA; Department of Pharmacology, Renal Research Institute, New York Medical College, Valhalla, New York, USA; Department of Physiology, Renal Research Institute, New York Medical College, Valhalla, New York, USA
| | - Jonathan Shein
- Department of Medicine, Renal Research Institute, New York Medical College, Valhalla, New York, USA; Department of Pharmacology, Renal Research Institute, New York Medical College, Valhalla, New York, USA; Department of Physiology, Renal Research Institute, New York Medical College, Valhalla, New York, USA
| | - Heli J Ruotsalainen
- Oulu Center for Cell-Matrix Research, Biocenter Oulu and Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland
| | - Taina A Pihlajaniemi
- Oulu Center for Cell-Matrix Research, Biocenter Oulu and Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland
| | - Michael S Goligorsky
- Department of Medicine, Renal Research Institute, New York Medical College, Valhalla, New York, USA; Department of Pharmacology, Renal Research Institute, New York Medical College, Valhalla, New York, USA; Department of Physiology, Renal Research Institute, New York Medical College, Valhalla, New York, USA.
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22
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Ingberg E, Dock H, Theodorsson E, Theodorsson A, Ström JO. Method parameters' impact on mortality and variability in mouse stroke experiments: a meta-analysis. Sci Rep 2016; 6:21086. [PMID: 26876353 PMCID: PMC4753409 DOI: 10.1038/srep21086] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Accepted: 01/13/2016] [Indexed: 12/17/2022] Open
Abstract
Although hundreds of promising substances have been tested in clinical trials,
thrombolysis currently remains the only specific pharmacological treatment for
ischemic stroke. Poor quality, e.g. low statistical power, in the preclinical
studies has been suggested to play an important role in these failures. Therefore,
it would be attractive to use animal models optimized to minimize unnecessary
mortality and outcome variability, or at least to be able to power studies more
exactly by predicting variability and mortality given a certain experimental setup.
The possible combinations of methodological parameters are innumerous, and an
experimental comparison of them all is therefore not feasible. As an alternative
approach, we extracted data from 334 experimental mouse stroke articles and, using a
hypothesis-driven meta-analysis, investigated the method parameters’
impact on infarct size variability and mortality. The use of Swiss and C57BL6 mice
as well as permanent occlusion of the middle cerebral artery rendered the lowest
variability of the infarct size while the emboli methods increased variability. The
use of Swiss mice increased mortality. Our study offers guidance for researchers
striving to optimize mouse stroke models.
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Affiliation(s)
- Edvin Ingberg
- Division of Microbiology and Molecular Medicine, Department of Clinical and Experimental Medicine, Linköping University, Department of Clinical Chemistry, Center for Diagnostics, Region Östergötland, Sweden
| | - Hua Dock
- Division of Microbiology and Molecular Medicine, Department of Clinical and Experimental Medicine, Linköping University, Department of Clinical Chemistry, Center for Diagnostics, Region Östergötland, Sweden
| | - Elvar Theodorsson
- Division of Microbiology and Molecular Medicine, Department of Clinical and Experimental Medicine, Linköping University, Department of Clinical Chemistry, Center for Diagnostics, Region Östergötland, Sweden
| | - Annette Theodorsson
- Division of Microbiology and Molecular Medicine, Department of Clinical and Experimental Medicine, Linköping University, Department of Clinical Chemistry, Center for Diagnostics, Region Östergötland, Sweden.,Division of Neuro and Inflammation Science, Department of Clinical and Experimental Medicine, Linköping University, Department of Neurosurgery, Anaesthetics, Operations and Specialty Surgery Center, Region Östergötland, Sweden
| | - Jakob O Ström
- Division of Microbiology and Molecular Medicine, Department of Clinical and Experimental Medicine, Linköping University, Department of Clinical Chemistry, Center for Diagnostics, Region Östergötland, Sweden.,Vårdvetenskapligt Forskningscentrum/Centre for Health Sciences, Örebro University Hospital, County Council of Örebro, Örebro, Sweden.,School of Health and Medical Sciences, Örebro University, Örebro, Sweden
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23
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Indomethacin induced gene regulation in the rat hippocampus. Mol Brain 2015; 8:59. [PMID: 26438564 PMCID: PMC4595115 DOI: 10.1186/s13041-015-0150-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2015] [Accepted: 09/30/2015] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND Non-steroidal anti-inflammatory drugs such as indomethacin are widely used to treat inflammatory diseases and manage pain, fever and inflammation in several conditions, including neuropsychiatric disorders. Although they predominantly function by inhibiting cyclooxygenase (COX) activity, important COX-independent actions also occur. These actions could be responsible for the adverse side effects associated with chronic and/or high dose usage of this popular drug class. RESULTS We examined gene regulation in the hippocampus after peripheral administration of indomethacin by employing a microarray approach. Secondary confirmation and the brain expression pattern of regulated genes was examined by in situ hybridization and immunohistochemistry. Transglutaminase 2, serum glucocorticoid inducible kinase, Inhibitor of NF-kappa B and vascular endothelial growth factor were among genes that were prominently upregulated, while G-protein coupled receptor 56 and neuropeptide Y were among genes that were downregulated by indomethacin. Co-localization studies using blood vessel markers revealed that transglutaminase 2 was induced specifically in brain vasculature. CONCLUSIONS The data demonstrate that COX-inhibitors can differentially regulate gene transcription in multiple, functionally distinctly cell types in the brain. The results provide additional insight into the molecular actions of COX-inhibitors and indicate that their effects on vasculature could influence cerebral blood flow mechanisms.
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Soveg F, Abdala-Valencia H, Campbell J, Morales-Nebreda L, Mutlu GM, Cook-Mills JM. Regulation of allergic lung inflammation by endothelial cell transglutaminase 2. Am J Physiol Lung Cell Mol Physiol 2015. [PMID: 26209276 DOI: 10.1152/ajplung.00199.2015] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Tissue transglutaminase 2 (TG2) is an enzyme with multiple functions, including catalysis of serotonin conjugation to proteins (serotonylation). Previous research indicates that TG2 expression is upregulated in human asthma and in the lung endothelium of ovalbumin (OVA)-challenged mice. It is not known whether endothelial cell TG2 is required for allergic inflammation. Therefore, to determine whether endothelial cell TG2 regulates allergic inflammation, mice with an endothelial cell-specific deletion of TG2 were generated, and these mice were sensitized and challenged in the airways with OVA. Deletion of TG2 in endothelial cells blocked OVA-induced serotonylation in lung endothelial cells, but not lung epithelial cells. Interestingly, deletion of endothelial TG2 reduced allergen-induced increases in respiratory system resistance, number of eosinophils in the bronchoalveolar lavage, and number of eosinophils in the lung tissue. Endothelial cell deletion of TG2 did not alter expression of adhesion molecules, cytokines, or chemokines that regulate leukocyte recruitment, consistent with other studies, demonstrating that deletion of endothelial cell signals does not alter lung cytokines and chemokines during allergic inflammation. Taken together, the data indicate that endothelial cell TG2 is required for allergic inflammation by regulating the recruitment of eosinophils into OVA-challenged lungs. In summary, TG2 functions as a critical signal for allergic lung responses. These data identify potential novel targets for intervention in allergy/asthma.
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Affiliation(s)
- Frank Soveg
- Allergy-Immunology Division, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Hiam Abdala-Valencia
- Allergy-Immunology Division, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Jackson Campbell
- Allergy-Immunology Division, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Luisa Morales-Nebreda
- Pulmonary Division, Northwestern University Feinberg School of Medicine, Chicago, Illinois; and
| | - Gökhan M Mutlu
- Pulmonary Division, Northwestern University Feinberg School of Medicine, Chicago, Illinois; and Section of Pulmonary and Critical Care Medicine, University of Chicago, Chicago, Illinois
| | - Joan M Cook-Mills
- Allergy-Immunology Division, Northwestern University Feinberg School of Medicine, Chicago, Illinois;
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25
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Cabrera-Fuentes HA, Lopez ML, McCurdy S, Fischer S, Meiler S, Baumer Y, Galuska SP, Preissner KT, Boisvert WA. Regulation of monocyte/macrophage polarisation by extracellular RNA. Thromb Haemost 2015; 113:473-81. [PMID: 25589344 DOI: 10.1160/th14-06-0507] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2014] [Accepted: 11/28/2014] [Indexed: 12/18/2022]
Abstract
Monocytes/macrophages respond to external stimuli with rapid changes in the expression of numerous inflammation-related genes to undergo polarisation towards the M1 (pro-inflammatory) or M2 (anti-inflammatory) phenotype. We have previously shown that, independently of Toll-like receptor activation, extracellular RNA (eRNA) could exert pro-thrombotic and pro-inflammatory properties in the cardiovascular system to provoke cytokine mobilisation. Here, mouse bone marrow-derived-macrophages (BMDM) differentiated with mouse macrophage-colony-stimulating factor (M-CSF) were found to be skewed towards the M1 phenotype when exposed to eRNA. This resulted in up-regulated expression of inflammatory markers such as Tnf-α and Il-6, together with Il-12 and iNOS, whereas anti-inflammatory genes such as chitinase-like proteins (Ym1/2) and macrophage mannose receptor-2 (Cd206) were significantly down-regulated. Human peripheral blood monocytes were treated with eRNA and analysed by micro-array analysis of the whole human genome, revealing an up-regulation of 79 genes by at least four-fold; 27 of which are related to signal transduction and 15 genes associated with inflammatory response. In accordance with the proposed actions of eRNA as a pro-inflammatory "alarm signal", these data shed light on the role of eRNA in the context of chronic inflammatory diseases such as atherosclerosis.
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Affiliation(s)
| | | | | | | | | | | | | | - Klaus T Preissner
- Klaus T. Preissner, PhD, Depart. Biochemistry, Medical School, Justus-Liebig-University, Friedrichstrasse 24, 35392 Giessen, Germany, Tel.: +49 641 994 7500, e-mail:
| | - William A Boisvert
- William A. Boisvert, PhD, Center for Cardiovascular Research, John A. Burns School of Medicine, University of Hawaii, 651 Ilalo Street, BSB 311C, Honolulu, HI 96813, USA, Tel.: + 1 808 692 1567, E-mail:
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26
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Li PC, Jiao Y, Ding J, Chen YC, Cui Y, Qian C, Yang XY, Ju SH, Yao HH, Teng GJ. Cystamine improves functional recovery via axon remodeling and neuroprotection after stroke in mice. CNS Neurosci Ther 2014; 21:231-40. [PMID: 25430473 DOI: 10.1111/cns.12343] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2014] [Revised: 09/28/2014] [Accepted: 09/29/2014] [Indexed: 12/30/2022] Open
Abstract
AIMS Stroke is a leading cause of disability. However, there is no pharmacological therapy available for promoting recovery. Although treatment of stroke with cystamine has gained increasing interest, the detailed mechanisms underlying this process remain elusive. Thus, our aim is to examine the effect of cystamine on the function recovery after stroke and investigate further cystamine mechanisms. METHODS Adult male C57BL/6J mice were subjected to photothrombotic model of focal stroke or sham operation. Cystamine or saline was administered intraperitoneally at 24 h after stroke. Functional recovery was analyzed using behavioral tests; axon remodeling was analyzed using magnetic resonance diffusion tensor imaging (DTI) and histological assessment. ANA-12, an antagonist of tropomyosin-related kinase B (TrkB), was administrated to examine the mechanisms underlying the neuroprotection mediated by cystamine. RESULTS Treatment with cystamine resulted in amelioration of impaired function with concomitant enhancement of axonal remodeling. Cystamine treatment significantly increased brain-derived neurotrophic factor (BDNF) levels and phosphorylation of TrkB in brain after stroke. Cystamine significantly enhanced neuronal progenitor cell proliferation, neuronal survival, and plasticity through BDNF/TrkB pathway. CONCLUSIONS These data provide evidence to investigate the promising utility of cystamine for therapy of stroke in a variety of ways, acting principally through BDNF/TrkB pathway.
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Affiliation(s)
- Pei-Cheng Li
- Jiangsu Key Laboratory of Molecular and Functional Imaging, Department of Radiology, Zhongda Hospital, Medical School of Southeast University, Nanjing, China
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27
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Ientile R, Currò M, Caccamo D. Transglutaminase 2 and neuroinflammation. Amino Acids 2014; 47:19-26. [PMID: 25398223 DOI: 10.1007/s00726-014-1864-2] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Accepted: 10/29/2014] [Indexed: 12/28/2022]
Abstract
Neuroinflammatory processes seem to play a pivotal role in various chronic neurodegenerative diseases, characterized also by the pathogenetic accumulation of specific protein aggregates. Several of these proteins have been shown to be substrates of transglutaminases, calcium-dependent enzymes that catalyze protein crosslinking reactions. However, it has recently been demonstrated that transglutaminase 2 (TG2) may also be involved in molecular mechanisms underlying inflammation. In the central nervous system, astrocytes and microglia are the cell types mainly involved in the inflammatory process. This review is focused on the increases of TG2 protein expression and enzyme activity that occur in astroglial, microglial and monocyte cell models in response to inflammatory stimuli. The transcription factor NF-κB is considered the main regulator of inflammation, being activated by a variety of stimuli including calcium influx, oxidative stress and inflammatory cytokines. Under these conditions, the over-expression of TG2 results in the sustained activation of NF-κB. Several findings emphasize the possible role of the TG2/NF-κB activation pathway in neurodegenerative diseases, including Alzheimer's disease, Parkinson's disease, multiple sclerosis and amyotrophic lateral sclerosis. Although further studies are needed to characterize the TG2/NF-κB cross-talk in monocytes/macrophages/microglia within the central nervous system, some results show that TG2 and NF-κB are co-localized in cell compartments. Together, evidence suggests that TG2 plays a role in neuroinflammation and contributes to the production of compounds that are potentially deleterious to neuronal cells.
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Affiliation(s)
- Riccardo Ientile
- Department of Biomedical Sciences and Morphological and Functional Imaging, University of Messina, AOU Policlinico "G. Martino", Via C. Valeria, Messina, Italy,
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28
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Espitia Pinzon N, Stroo E, ‘t Hart BA, Bol JGJM, Drukarch B, Bauer J, van Dam AM. Tissue transglutaminase in marmoset experimental multiple sclerosis: discrepancy between white and grey matter. PLoS One 2014; 9:e100574. [PMID: 24959868 PMCID: PMC4069090 DOI: 10.1371/journal.pone.0100574] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2014] [Accepted: 05/26/2014] [Indexed: 02/06/2023] Open
Abstract
Infiltration of leukocytes is a major pathological event in white matter lesion formation in the brain of multiple sclerosis (MS) patients. In grey matter lesions, less infiltration of these cells occur, but microglial activation is present. Thus far, the interaction of β-integrins with extracellular matrix proteins, e.g. fibronectin, is considered to be of importance for the influx of immune cells. Recent in vitro studies indicate a possible role for the enzyme tissue Transglutaminase (TG2) in mediating cell adhesion and migration. In the present study we questioned whether TG2 is present in white and grey matter lesions observed in the marmoset model for MS. To this end, immunohistochemical studies were performed. We observed that TG2, expressed by infiltrating monocytes in white matter lesions co-expressed β1-integrin and is located in close apposition to deposited fibronectin. These data suggest an important role for TG2 in the adhesion and migration of infiltrating monocytes during white matter lesion formation. Moreover, in grey matter lesions, TG2 is mainly present in microglial cells together with some β1-integrin, whereas fibronectin is absent in these lesions. These data imply an alternative role for microglial-derived TG2 in grey matter lesions, e.g. cell proliferation. Further research should clarify the functional role of TG2 in monocytes or microglial cells in MS lesion formation.
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Affiliation(s)
- Nathaly Espitia Pinzon
- VU University Medical Center, Neuroscience Campus Amsterdam, Department of Anatomy and Neurosciences, Amsterdam, The Netherlands
| | - Esther Stroo
- VU University Medical Center, Neuroscience Campus Amsterdam, Department of Anatomy and Neurosciences, Amsterdam, The Netherlands
| | - Bert A. ‘t Hart
- Biomedical Primate Research Center, Department of Immunobiology, Rijswijk, The Netherlands
- University Groningen, University Medical Center, Department of Neuroscience, Groningen, The Netherlands
| | - John G. J. M. Bol
- VU University Medical Center, Neuroscience Campus Amsterdam, Department of Anatomy and Neurosciences, Amsterdam, The Netherlands
| | - Benjamin Drukarch
- VU University Medical Center, Neuroscience Campus Amsterdam, Department of Anatomy and Neurosciences, Amsterdam, The Netherlands
| | - Jan Bauer
- Center for Brain Research, Department of Neuroimmunology, Vienna, Austria
| | - Anne-Marie van Dam
- VU University Medical Center, Neuroscience Campus Amsterdam, Department of Anatomy and Neurosciences, Amsterdam, The Netherlands
- * E-mail:
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29
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Miura A, Kambe Y, Inoue K, Tatsukawa H, Kurihara T, Griffin M, Kojima S, Miyata A. Pituitary adenylate cyclase-activating polypeptide type 1 receptor (PAC1) gene is suppressed by transglutaminase 2 activation. J Biol Chem 2013; 288:32720-32730. [PMID: 24045949 DOI: 10.1074/jbc.m113.452706] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Pituitary adenylate cyclase-activating polypeptide (PACAP) functions as a neuroprotective factor through the PACAP type 1 receptor, PAC1. In a previous work, we demonstrated that nerve growth factor augmented PAC1 gene expression through the activation of Sp1 via the Ras/MAPK pathway. We also observed that PAC1 expression in Neuro2a cells was transiently suppressed during in vitro ischemic conditions, oxygen-glucose deprivation (OGD). Because endoplasmic reticulum (ER) stress is induced by ischemia, we attempted to clarify how ER stress affects the expression of PAC1. Tunicamycin, which induces ER stress, significantly suppressed PAC1 gene expression, and salubrinal, a selective inhibitor of the protein kinase RNA-like endoplasmic reticulum kinase signaling pathway of ER stress, blocked the suppression. In luciferase reporter assay, we found that two Sp1 sites were involved in suppression of PAC1 gene expression due to tunicamycin or OGD. Immunocytochemical staining demonstrated that OGD-induced transglutaminase 2 (TG2) expression was suppressed by salubrinal or cystamine, a TG activity inhibitor. Further, the OGD-induced accumulation of cross-linked Sp1 in nuclei was suppressed by cystamine or salubrinal. Together with cystamine, R283, TG2-specific inhibitor, and siRNA specific for TG2 also ameliorated OGD-induced attenuation of PAC1 gene expression. These results suggest that Sp1 cross-linking might be crucial in negative regulation of PAC1 gene expression due to TG2 in OGD-induced ER stress.
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Affiliation(s)
- Ayako Miura
- From the Department of Pharmacology, Graduate School of Medical and Dental Sciences, University of Kagoshima, Kagoshima 890-8544, Japan
| | - Yuki Kambe
- From the Department of Pharmacology, Graduate School of Medical and Dental Sciences, University of Kagoshima, Kagoshima 890-8544, Japan
| | - Kazuhiko Inoue
- From the Department of Pharmacology, Graduate School of Medical and Dental Sciences, University of Kagoshima, Kagoshima 890-8544, Japan
| | - Hideki Tatsukawa
- the Molecular Ligand Biology Research Team, Chemical Genomics Research Group, Chemical Biology Department, RIKEN Advanced Science Institute, Wako 351-0198, Japan
| | - Takashi Kurihara
- From the Department of Pharmacology, Graduate School of Medical and Dental Sciences, University of Kagoshima, Kagoshima 890-8544, Japan
| | - Martin Griffin
- the School of Life and Health Sciences, Aston University, Birmingham B4 7ET, United Kingdom
| | - Soichi Kojima
- the Molecular Ligand Biology Research Team, Chemical Genomics Research Group, Chemical Biology Department, RIKEN Advanced Science Institute, Wako 351-0198, Japan
| | - Atsuro Miyata
- From the Department of Pharmacology, Graduate School of Medical and Dental Sciences, University of Kagoshima, Kagoshima 890-8544, Japan,.
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30
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Koenig O, Walker T, Perle N, Zech A, Neumann B, Schlensak C, Wendel HP, Nolte A. New aspects of gene-silencing for the treatment of cardiovascular diseases. Pharmaceuticals (Basel) 2013; 6:881-914. [PMID: 24276320 PMCID: PMC3816708 DOI: 10.3390/ph6070881] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2013] [Revised: 06/15/2013] [Accepted: 07/11/2013] [Indexed: 01/17/2023] Open
Abstract
Coronary heart disease (CHD), mainly caused by atherosclerosis, represents the single leading cause of death in industrialized countries. Besides the classical interventional therapies new applications for treatment of vascular wall pathologies are appearing on the horizon. RNA interference (RNAi) represents a novel therapeutic strategy due to sequence-specific gene-silencing through the use of small interfering RNA (siRNA). The modulation of gene expression by short RNAs provides a powerful tool to theoretically silence any disease-related or disease-promoting gene of interest. In this review we outline the RNAi mechanisms, the currently used delivery systems and their possible applications to the cardiovascular system. Especially, the optimization of the targeting and transfection procedures could enhance the efficiency of siRNA delivery drastically and might open the way to clinical applicability. The new findings of the last years may show the techniques to new innovative therapies and could probably play an important role in treating CHD in the future.
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Affiliation(s)
- Olivia Koenig
- Clinical Research Laboratory, Dept. of Thoracic, Cardiac and Vascular Surgery, University Hospital Tuebingen, Calwerstr. 7/1, 72076 Tuebingen, Germany.
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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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Gundemir S, Colak G, Feola J, Blouin R, Johnson GVW. Transglutaminase 2 facilitates or ameliorates HIF signaling and ischemic cell death depending on its conformation and localization. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2012; 1833:1-10. [PMID: 23085038 DOI: 10.1016/j.bbamcr.2012.10.011] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2012] [Revised: 10/09/2012] [Accepted: 10/10/2012] [Indexed: 12/26/2022]
Abstract
Transglutaminase 2 (TG2) is a widely expressed and multifunctional protein that modulates cell death/survival processes. We have previously shown that TG2 binds to hypoxia inducible factor 1β (HIF1β) and decreases the upregulation of HIF responsive genes; however, the relationship between these observations was not investigated. In this study, we investigated whether endogenous TG2 is sufficient to suppress HIF activity and whether the interaction between TG2 and HIF1β is required for this suppression. shRNA-mediated silencing of TG2 significantly enhanced HIF activation in response to hypoxia. In addition, nuclear localization of TG2 is required for its suppressive effect on HIF activity, with TG2 being recruited to HIF responsive promoters in hypoxic conditions. These observations suggest that TG2 directly regulates hypoxic transcriptional machinery; however, its interaction with HIF1β was not required for this regulation. We also examined whether TG2's effect on cell death/survival processes in ischemia is due to its effects on HIF signaling. Our results indicate that TG2 mediated HIF suppression can be separated from TG2's effect on cell survival in hypoxic/hypoglycemic conditions. Lastly, here we show that nuclear TG2 in the closed conformation and non-nuclear TG2 in the open conformation have opposing effects on hypoxic/hypoglycemic cell death, which could explain previous controversial results. Overall, our results further clarify the role of TG2 in mediating the cellular response to ischemia and suggest that manipulating the conformation of TG2 might be of pharmacological interest as a therapeutic strategy for the treatment of ischemia-related pathologies.
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Affiliation(s)
- Soner Gundemir
- Department of Anesthesiology, University of Rochester, Rochester, NY, USA
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33
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Transglutaminase inhibition protects against oxidative stress-induced neuronal death downstream of pathological ERK activation. J Neurosci 2012; 32:6561-9. [PMID: 22573678 DOI: 10.1523/jneurosci.3353-11.2012] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Molecular deletion of transglutaminase 2 (TG2) has been shown to improve function and survival in a host of neurological conditions including stroke, Huntington's disease, and Parkinson's disease. However, unifying schemes by which these cross-linking or polyaminating enzymes participate broadly in neuronal death have yet to be presented. Unexpectedly, we found that in addition to TG2, TG1 gene expression level is significantly induced following stroke in vivo or due to oxidative stress in vitro. Forced expression of TG1 or TG2 proteins is sufficient to induce neuronal death in Rattus norvegicus cortical neurons in vitro. Accordingly, molecular deletion of TG2 alone is insufficient to protect Mus musculus neurons from oxidative death. By contrast, structurally diverse inhibitors used at concentrations that inhibit TG1 and TG2 simultaneously are neuroprotective. These small molecules inhibit increases in neuronal transamidating activity induced by oxidative stress; they also protect neurons downstream of pathological ERK activation when added well after the onset of the death stimulus. Together, these studies suggest that multiple TG isoforms, not only TG2, participate in oxidative stress-induced cell death signaling; and that isoform nonselective inhibitors of TG will be most efficacious in combating oxidative death in neurological disorders.
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34
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Raghunathan S, Patel BM. Therapeutic implications of small interfering RNA in cardiovascular diseases. Fundam Clin Pharmacol 2012; 27:1-20. [DOI: 10.1111/j.1472-8206.2012.01051.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2011] [Revised: 04/17/2012] [Accepted: 06/01/2012] [Indexed: 01/07/2023]
Affiliation(s)
- Suchi Raghunathan
- Institute of Pharmacy; Nirma University; Ahmedabad; 382 481; Gujarat; India
| | - Bhoomika M. Patel
- Institute of Pharmacy; Nirma University; Ahmedabad; 382 481; Gujarat; India
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