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Lockridge O, Schopfer LM. Naturally Occurring Epsilon Gamma Glutamyl Lysine Isopeptide Crosslinks in Human Neuroblastoma SH-SY5Y Cells. ACS OMEGA 2022; 7:21978-21986. [PMID: 35785306 PMCID: PMC9245130 DOI: 10.1021/acsomega.2c02502] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Accepted: 06/07/2022] [Indexed: 05/05/2023]
Abstract
Zero-length isopeptide crosslinks between the side chains of glutamine and lysine are the product of transglutaminase activity. It is generally accepted that transglutaminase activity is dormant under physiological conditions because the calcium concentration inside cells is too low to activate transglutaminase to an open conformation with access to the catalytic triad. Traditional assays for transglutaminase activity measure incorporation of biotin pentylamine or of radiolabeled putrescine in the presence of added calcium. In this report, we identified naturally occurring isopeptide crosslinked proteins using the following steps: immunopurification of tryptic peptides by binding to anti-isopeptide antibody 81D1C2, separation of immunopurified peptides by liquid chromatography-tandem mass spectrometry, Protein Prospector database searches of mass spectrometry data for isopeptide crosslinked peptides, and manual evaluation of candidate crosslinked peptide pairs. The most labor intense step was manual evaluation. We developed criteria for accepting and rejecting candidate crosslinked peptides and showed examples of MS/MS spectra that confirm or invalidate a possible crosslink. The SH-SY5Y cells that we examined for crosslinked proteins had not been exposed to calcium and had been lysed in the presence of ethylenediaminetetraacetic acid. This precaution allows us to claim that the crosslinks we found inside the cells occurred naturally under physiological conditions. The quantity of crosslinks was very low, and the crosslinked proteins were mostly low abundance proteins. In conclusion, intracellular transglutaminase crosslinking/transamidase activity is very low but detectable. The low level of intracellular crosslinked proteins is consistent with tight regulation of transglutaminase activity.
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Pearse DD, Hefley AB, Morales AA, Ghosh M. Comparative Profiling of TG2 and Its Effectors in Human Relapsing Remitting and Progressive Multiple Sclerosis. Biomedicines 2022; 10:biomedicines10061241. [PMID: 35740263 PMCID: PMC9220003 DOI: 10.3390/biomedicines10061241] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Revised: 05/06/2022] [Accepted: 05/13/2022] [Indexed: 02/05/2023] Open
Abstract
Multiple Sclerosis (MS) is a chronic CNS autoimmune disease characterized by immune-mediated demyelination, axon loss, and disability. Dysregulation of transglutaminase-2 (TG2) has been implicated in disease initiation and progression. Herein, TG2 expression in post-mortem human brain tissue from Relapsing Remitting MS (RRMS) or Progressive MS (PMS) individuals were examined and correlated with the presence of TG2 binding partners and effectors implicated in the processes of inflammation, scar formation, and the antagonism of repair. Tissues from Relapsing-Remitting Multiple Sclerosis (RRMS; n = 6), Progressive Multiple Sclerosis (PMS; n = 5), and non-MS control (n = 6) patients underwent immunohistochemistry for TG2, PLA2, COX-2, FN, CSPG, and HSPG. TG2 was strongly upregulated in active RRMS and PMS lesions, within blood vessels and the perivascular tissue of sclerotic plaques. TG2 colocalization was observed with GFAP+ astrocytes and ECM, including FN, HSPG, and CSPG, which also increased in either RRMS or PMS lesions. Although TG2 was not colocalized with inflammatory mediators COX-2 and PLA2, or the macrophage-microglia marker Iba1, its increased expression correlated with their elevation in active RRMS and PMS lesions. In summary, the correlation of strong TG2 induction in either RRMS or PMS with some of its binding partners but not others implicates potentially different roles for TG2 in disparate MS forms that may warrant further investigation.
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Affiliation(s)
- Damien D. Pearse
- The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL 33136, USA; (D.D.P.); (A.B.H.); (A.A.M.)
- The Department of Neurological Surgery, University of Miami Miller School of Medicine, Miami, FL 33136, USA
- The Neuroscience Program, University of Miami Miller School of Medicine, Miami, FL 33136, USA
- The Interdisciplinary Stem Cell Institute, University of Miami Miller School of Medicine, Miami, FL 33136, USA
- Department of Veterans Affairs, Veterans Affairs Medical Center, Miami, FL 33136, USA
| | - Andrew B. Hefley
- The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL 33136, USA; (D.D.P.); (A.B.H.); (A.A.M.)
| | - Alejo A. Morales
- The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL 33136, USA; (D.D.P.); (A.B.H.); (A.A.M.)
| | - Mousumi Ghosh
- The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL 33136, USA; (D.D.P.); (A.B.H.); (A.A.M.)
- The Department of Neurological Surgery, University of Miami Miller School of Medicine, Miami, FL 33136, USA
- Department of Veterans Affairs, Veterans Affairs Medical Center, Miami, FL 33136, USA
- Correspondence: ; Tel.: +1-305-243-9968; Fax: +1-305-243-3923
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Wilhelmus MMM, Tonoli E, Coveney C, Boocock DJ, Jongenelen CAM, Brevé JJP, Verderio EAM, Drukarch B. The Transglutaminase-2 Interactome in the APP23 Mouse Model of Alzheimer's Disease. Cells 2022; 11:cells11030389. [PMID: 35159198 PMCID: PMC8834516 DOI: 10.3390/cells11030389] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 01/06/2022] [Accepted: 01/14/2022] [Indexed: 02/06/2023] Open
Abstract
Amyloid-beta (Aβ) deposition in the brain is closely linked with the development of Alzheimer’s disease (AD). Unfortunately, therapies specifically targeting Aβ deposition have failed to reach their primary clinical endpoints, emphasizing the need to broaden the search strategy for alternative targets/mechanisms. Transglutaminase-2 (TG2) catalyzes post-translational modifications, is present in AD lesions and interacts with AD-associated proteins. However, an unbiased overview of TG2 interactors is lacking in both control and AD brain. Here we aimed to identify these interactors using a crossbreed of the AD-mimicking APP23 mouse model with wild type and TG2 knock-out (TG2−/−) mice. We found that absence of TG2 had no (statistically) significant effect on Aβ pathology, soluble brain levels of Aβ1–40 and Aβ1–42, and mRNA levels of TG family members compared to APP23 mice at 18 months of age. Quantitative proteomics and network analysis revealed a large cluster of TG2 interactors involved in synaptic transmission/assembly and cell adhesion in the APP23 brain typical of AD. Comparative proteomics of wild type and TG2−/− brains revealed a TG2-linked pathological proteome consistent with alterations in both pathways. Our data show that TG2 deletion leads to considerable network alterations consistent with a TG2 role in (dys)regulation of synaptic transmission and cell adhesion in APP23 brains.
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Affiliation(s)
- Micha M. M. Wilhelmus
- Department of Anatomy and Neurosciences, Amsterdam Neuroscience, Amsterdam UMC, Vrije Universiteit Amsterdam, 1081 HZ Amsterdam, The Netherlands; (M.M.M.W.); (C.A.M.J.); (J.J.P.B.); (B.D.)
| | - Elisa Tonoli
- School of Science and Technology, Nottingham Trent University, Nottingham NG11 8NS, UK; (E.T.); (C.C.); (D.J.B.)
| | - Clare Coveney
- School of Science and Technology, Nottingham Trent University, Nottingham NG11 8NS, UK; (E.T.); (C.C.); (D.J.B.)
| | - David J. Boocock
- School of Science and Technology, Nottingham Trent University, Nottingham NG11 8NS, UK; (E.T.); (C.C.); (D.J.B.)
| | - Cornelis A. M. Jongenelen
- Department of Anatomy and Neurosciences, Amsterdam Neuroscience, Amsterdam UMC, Vrije Universiteit Amsterdam, 1081 HZ Amsterdam, The Netherlands; (M.M.M.W.); (C.A.M.J.); (J.J.P.B.); (B.D.)
| | - John J. P. Brevé
- Department of Anatomy and Neurosciences, Amsterdam Neuroscience, Amsterdam UMC, Vrije Universiteit Amsterdam, 1081 HZ Amsterdam, The Netherlands; (M.M.M.W.); (C.A.M.J.); (J.J.P.B.); (B.D.)
| | - Elisabetta A. M. Verderio
- School of Science and Technology, Nottingham Trent University, Nottingham NG11 8NS, UK; (E.T.); (C.C.); (D.J.B.)
- Department of Biological Sciences, Alma Mater Studiorum University of Bologna, 40126 Bologna, Italy
- Correspondence: ; Tel.: +44-115-8486628
| | - Benjamin Drukarch
- Department of Anatomy and Neurosciences, Amsterdam Neuroscience, Amsterdam UMC, Vrije Universiteit Amsterdam, 1081 HZ Amsterdam, The Netherlands; (M.M.M.W.); (C.A.M.J.); (J.J.P.B.); (B.D.)
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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: 13] [Impact Index Per Article: 4.3] [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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Patra SK. Emerging histone glutamine modifications mediated gene expression in cell differentiation and the VTA reward pathway. Gene 2020; 768:145323. [PMID: 33221535 DOI: 10.1016/j.gene.2020.145323] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Revised: 10/21/2020] [Accepted: 11/16/2020] [Indexed: 12/17/2022]
Abstract
Gene expression is the key to cellular functions and homeostasis. Histone modifications regulate chromatin dynamics and gene expression. Neuronal cell functions largely depend on fluxes of neurotransmitters for activation of chromatin and gene expression. New studies by Lepack et al. and Farrelly et al. recently demonstrated how tissue transglutaminase 2 (TGM2) mediated histone glutamine modifications, either dopaminylation in the dopaminergic reward pathway or serotonylation in the context of cellular differentiation and signaling regulate gene expression and decipher striking differences from their known functions. This opens new avenues of research in the field of epigenetics in general and neuroepigenetics as special; and to find out the enzymes responsible for the reversible reaction of histone de-dopaminylation and de-serotonylation.
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Affiliation(s)
- Samir Kumar Patra
- Epigenetics and Cancer Research Laboratory, Biochemistry and Molecular Biology Group, Department of Life Science, National Institute of Technology, Rourkela, Odisha 769008, India.
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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: 13] [Impact Index Per Article: 2.6] [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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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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9
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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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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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