101
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Hodrea J, Demény MA, Majai G, Sarang Z, Korponay-Szabó IR, Fésüs L. Transglutaminase 2 is expressed and active on the surface of human monocyte-derived dendritic cells and macrophages. Immunol Lett 2010; 130:74-81. [PMID: 20005901 DOI: 10.1016/j.imlet.2009.12.010] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2009] [Revised: 11/27/2009] [Accepted: 12/02/2009] [Indexed: 11/25/2022]
Abstract
The multifunctional enzyme, transglutaminase 2 (TG2), can be found intracellularly, in the extracellular matrix and on the cell surface. Cell surface TG2 (csTG2) could not be detected by TG2-specific antibodies or autoantibodies on immunocompetent cells. A supposedly csTG2-specific antibody, 6B9, was recently shown to actually react with CD44. Though the importance of TG2-mediated deamidation of gluten in the pathogenesis of celiac disease has been well recognized, it is not known in which intestinal cells or cell compartment the deamidation occurs. Duodenal dendritic cells (DCs) can be directly involved in gluten-reactive T-cell activation. Here we use blood monocyte-derived dendritic cells (iDC) and macrophages (MPhi) as a model for intestinal antigen-presenting cells (APCs) and show that they contain large amounts of TG2. We found that TG100, a commercial TG2-specific monoclonal antibody can recognize TG2 on the surface of these cells, that is monocyte-derived APCs express surface-associated TG2. TG2 expression was found on the surface of individual tunica propria cells in frozen small bowel tissue sections from both normal and celiac subjects. We also demonstrate that the pool of TG2 on the surface of iDCs can be catalytically active, hence it might directly be involved in the deamidation of gliadin peptides. Bacterial lipopolysaccharide (LPS) increased the level of TG2 on the surface of maturing DCs, supporting the hypothesis that an unspecific inflammatory process in the gut may expose more transglutaminase activity.
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Affiliation(s)
- Judit Hodrea
- Department of Biochemistry and Molecular Biology, Hungarian Academy of Sciences, University of Debrecen, Debrecen, Hungary
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102
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Di Niro R, Sulic AM, Mignone F, D'Angelo S, Bordoni R, Iacono M, Marzari R, Gaiotto T, Lavric M, Bradbury ARM, Biancone L, Zevin-Sonkin D, De Bellis G, Santoro C, Sblattero D. Rapid interactome profiling by massive sequencing. Nucleic Acids Res 2010; 38:e110. [PMID: 20144949 PMCID: PMC2875021 DOI: 10.1093/nar/gkq052] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
We have developed a high-throughput protein expression and interaction analysis platform that combines cDNA phage display library selection and massive gene sequencing using the 454 platform. A phage display library of open reading frame (ORF) fragments was created from mRNA derived from different tissues. This was used to study the interaction network of the enzyme transglutaminase 2 (TG2), a multifunctional enzyme involved in the regulation of cell growth, differentiation and apoptosis, associated with many different pathologies. After two rounds of panning with TG2 we assayed the frequency of ORFs within the selected phage population using 454 sequencing. Ranking and analysis of more than 120 000 sequences allowed us to identify several potential interactors, which were subsequently confirmed in functional assays. Within the identified clones, three had been previously described as interacting proteins (fibronectin, SMOC1 and GSTO2), while all the others were new. When compared with standard systems, such as microtiter enzyme-linked immunosorbant assay, the method described here is dramatically faster and yields far more information about the interaction under study, allowing better characterization of complex systems. For example, in the case of fibronectin, it was possible to identify the specific domains involved in the interaction.
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Affiliation(s)
- Roberto Di Niro
- Department of Life Sciences, University of Trieste, Trieste, Italy
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103
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Király R, Csosz E, Kurtán T, Antus S, Szigeti K, Simon-Vecsei Z, Korponay-Szabó IR, Keresztessy Z, Fésüs L. Functional significance of five noncanonical Ca2+-binding sites of human transglutaminase 2 characterized by site-directed mutagenesis. FEBS J 2009; 276:7083-96. [PMID: 19878304 DOI: 10.1111/j.1742-4658.2009.07420.x] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The multifunctional tissue transglutaminase 2 (TG2) has a four-domain structure with several Ca(2+)-regulated biochemical activities, including transglutamylation and GTP hydrolysis. The structure of the Ca(2+)-binding form of the human enzyme is not known, and its Ca(2+)-binding sites have not been fully characterized. By mutagenesis, we have targeted its active site Cys, three sites based on homology to Ca(2+)-binding residues of epidermal transglutaminase and factor XIIIa (S1-S3), and two regions with negative surface potentials (S4 and S5). CD spectroscopy, antibody-binding assay and GTPase activity measurements indicated that the amino acid substitutions did not cause major structural alterations. Calcium-45 equilibrium dialysis and isothermal calorimetric titration showed that both wild-type and active site-deleted enzymes (C277S) bind six Ca(2+). Each of the S1-S5 mutants binds fewer than six Ca(2+), S1 is a strong Ca(2+)-binding site, and mutation of one site resulted in the loss of more than one bound Ca(2+), suggesting cooperativity among sites. All mutants were deficient in transglutaminase activity, and GTP inhibited remnant activities. Like those of the wild-type enzyme, the GTPase activities of the mutants were inhibited by Ca(2+), except in the case of the S4 and S5 mutants, which exhibited increased activity. TG2 is the major autoantigen in celiac disease, and testing the reactivity of mutants with autoantibodies from celiac disease patients revealed that S4 strongly determines antigenicity. It can be concluded that five of the Ca(2+)-binding sites of TG2 influence its transglutaminase activity, two sites are involved in the regulation of GTPase activity, and one determines antigenicity for autoantibodies in celiac patients.
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Affiliation(s)
- Róbert Király
- Apoptosis and Genomics Research Group of Hungarian Academy of Sciences, Debrecen, Hungary.
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104
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Transglutaminase 2 suppresses apoptosis by modulating caspase 3 and NF-kappaB activity in hypoxic tumor cells. Oncogene 2009; 29:356-67. [PMID: 19838207 DOI: 10.1038/onc.2009.342] [Citation(s) in RCA: 105] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The expression of hypoxia-inducible factor-1 (HIF-1) correlates with poor clinical outcomes and confers resistance to the apoptosis of the tumor cells that are exposed to hypoxia. Presently, the mechanism underlying this phenomenon is poorly understood. In this study we provide evidence that transglutaminase 2 (TG2), an enzyme that catalyses protein crosslinking reactions, is a transcriptional target of HIF-1 to enhance the survival of hypoxic cells. We found that hypoxia induces TG2 expression through an HIF-1 dependent pathway and concurrently activates intracellular TG2. The hypoxic cells overexpressing TG2 showed resistance to apoptosis. Conversely, the hypoxic cells treated with either TG2 inhibitor or small interfering RNA (siRNA) became sensitive to apoptosis. Activation of TG2 in response to hypoxic stress inhibited caspase-3 activity by forming crosslinked multimer, resulting in insoluble aggregates. TG2 also activates nuclear factor (NF)-kappaB pathway after hypoxic stress, and thereby induces the expression of cellular inhibitor of apoptosis 2. The anti-apoptotic role of TG2 was further confirmed in vivo using xenografts in athymic mice. Our results indicate that TG2 is an anti-apoptotic mediator of HIF-1 through modulating both apoptosis and survival pathways and may confer a selective growth advantage to tumor cells. These findings suggest that the inhibition of TG2 may offer a novel strategy for anticancer therapy.
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105
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Ponnusamy M, Pang M, Annamaraju PK, Zhang Z, Gong R, Chin YE, Zhuang S. Transglutaminase-1 protects renal epithelial cells from hydrogen peroxide-induced apoptosis through activation of STAT3 and AKT signaling pathways. Am J Physiol Renal Physiol 2009; 297:F1361-70. [PMID: 19710241 DOI: 10.1152/ajprenal.00251.2009] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Our recent studies showed that transglutaminase-1 (TGase-1) is uniquely expressed in mouse renal proximal tubular cells (RPTC) and mediates cell proliferation. In this study, we investigated the role of TGase-1 in cell survival and the survival signaling pathways regulated by TGase-1 in RPTC following oxidant injury. Exposure of RPTC to hydrogen peroxide (H2O2) resulted in apoptosis and an increase in TGase activity. Inhibition of TGase activity with monodansylcadervine (MDC), a TGase inhibitor, or knockdown of TGase-1 with small interference (si)RNA enhanced apoptosis and decreased cell survival in H2O2-treated RPTC. Conversely, overexpression of TGase-1 rendered RPTC more resistant to H2O2 toxicity and MDC treatment blocked this response. Concurrent with RPTC apoptosis, phosphorylation of AKT, signal transducer and activator of transcription-3 (STAT3), and glucogen synthase kinase-3beta (GSK-3beta) were observed. Pretreatment of cells with MDC or TGase-1 siRNA inhibited phosphorylation of all these molecules. Inhibition of either the AKT or STAT3 pathway potentiated H2O2-induced cell death and increased GSK-3beta activity by dephosphorylation at serine 9. Furthermore, treatment with GSK-3beta inhibitors reduced H2O2-induced apoptosis and abolished the death-promoting effect of AKT and STAT3 inhibition. Therefore, we have identified TGase-1 as a novel survival factor in renal epithelial cells and it contributes to cell survival through activation of the AKT and STAT3 signaling pathways following oxidant injury.
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Affiliation(s)
- Murugavel Ponnusamy
- Department of Medicine, Brown University School of Medicine, Rhode Island Hospital, Providence, RI 02903, USA
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106
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Iismaa SE, Mearns BM, Lorand L, Graham RM. Transglutaminases and disease: lessons from genetically engineered mouse models and inherited disorders. Physiol Rev 2009; 89:991-1023. [PMID: 19584319 DOI: 10.1152/physrev.00044.2008] [Citation(s) in RCA: 264] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
The human transglutaminase (TG) family consists of a structural protein, protein 4.2, that lacks catalytic activity, and eight zymogens/enzymes, designated factor XIII-A (FXIII-A) and TG1-7, that catalyze three types of posttranslational modification reactions: transamidation, esterification, and hydrolysis. These reactions are essential for biological processes such as blood coagulation, skin barrier formation, and extracellular matrix assembly but can also contribute to the pathophysiology of various inflammatory, autoimmune, and degenerative conditions. Some members of the TG family, for example, TG2, can participate in biological processes through actions unrelated to transamidase catalytic activity. We present here a comprehensive review of recent insights into the physiology and pathophysiology of TG family members that have come from studies of genetically engineered mouse models and/or inherited disorders. The review focuses on FXIII-A, TG1, TG2, TG5, and protein 4.2, as mice deficient in TG3, TG4, TG6, or TG7 have not yet been reported, nor have mutations in these proteins been linked to human disease.
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Affiliation(s)
- Siiri E Iismaa
- Molecular Cardiology and Biophysics Division, Victor Chang Cardiac Research Institute and Universityof New South Wales, Sydney, New South Wales 2010, Australia
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107
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Jogie-Brahim S, Feldman D, Oh Y. Unraveling insulin-like growth factor binding protein-3 actions in human disease. Endocr Rev 2009; 30:417-37. [PMID: 19477944 PMCID: PMC2819737 DOI: 10.1210/er.2008-0028] [Citation(s) in RCA: 230] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The IGF system plays critical roles in somatic growth in an endocrine fashion (somatomedin hypothesis) as well as proliferation and differentiation of normal and malignant cells in a paracrine/autocrine fashion. IGFBP-3 is known to modulate the actions of IGFs in circulation as well as the immediate extracellular environment. Interestingly, apart from the ability to inhibit or enhance IGF actions, IGFBP-3 also exhibits very clear, distinct biological effects independent of the IGF/IGF-I receptor axis. Over the past decade it has become widely appreciated that IGF/IGF-IR-independent actions of IGFBP-3 (antiproliferative and proapoptotic effects) contribute to improving the pathophysiology of a variety of human diseases, such as cancer, diabetes, and malnutrition. Recent studies have implicated interaction of IGFBP-3 with a variety of proteins or signaling cascades critical to cell cycle control and apoptosis; however, the actual mechanism of IGFBP-3 action is still unclear. This review reinforces the concept in support of the IGF/IGF-IR axis-independent actions of IGFBP-3 and delineates potential underlying mechanisms involved and subsequent biological significance, focusing in particular on functional binding partners and the clinical significance of IGFBP-3 in the assessment of cancer risk.
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Affiliation(s)
- Sherryline Jogie-Brahim
- Department of Pathology, Medical College of Virginia Campus, Virginia Commonwealth University, Richmond, Virginia 23298-0662, USA
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108
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Malorni W, Farrace MG, Matarrese P, Tinari A, Ciarlo L, Mousavi-Shafaei P, D'Eletto M, Di Giacomo G, Melino G, Palmieri L, Rodolfo C, Piacentini M. The adenine nucleotide translocator 1 acts as a type 2 transglutaminase substrate: implications for mitochondrial-dependent apoptosis. Cell Death Differ 2009; 16:1480-92. [PMID: 19644512 DOI: 10.1038/cdd.2009.100] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
In this study we provide in vitro and in vivo evidence showing that the protein disulphide isomerase (PDI) activity of type 2 transglutaminase (TG2) regulates the correct assembly and function of the mitochondrial ADP/ATP transporter adenine nucleotide translocator 1 (ANT1). We demonstrate, by means of biochemical and morphological analyses, that ANT1 and TG2 physically interact in the mitochondria. Under physiological conditions, TG2's PDI activity regulates the ADP/ATP transporter function by controlling the oligomerization of ANT1. In fact, mitochondria isolated from hearts of TG2(-/-) mice exhibit increased polymerization of ANT1, paralleled by an enhanced ADP/ATP carrier activity, as compared to mitochondria belonging to TG2(+/+) mice. Interestingly, upon cell-death induction, ANT1 becomes a substrate for TG2's cross-linking activity and the lack of TG2 results in a reduction of apoptosis as well as in a marked sensitivity to the ADP/ATP exchange inhibition by atractyloside. These findings suggest a complex TG2-dependent regulation of the ADP/ATP transporter and reveal new important avenues for its potential applications in the treatment of some mitochondrial-dependent diseases, including cardiovascular and neurodegenerative diseases.
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Affiliation(s)
- W Malorni
- Department of Therapeutic Research and Medicine Evaluation, National Institute of Health, Rome, Italy
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109
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Gundemir S, Johnson GVW. Intracellular localization and conformational state of transglutaminase 2: implications for cell death. PLoS One 2009; 4:e6123. [PMID: 19568436 PMCID: PMC2701606 DOI: 10.1371/journal.pone.0006123] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2009] [Accepted: 06/02/2009] [Indexed: 02/03/2023] Open
Abstract
Transglutaminase 2 (TG2) is a multifunctional enzyme that has guanine nucleotide binding and GTP hydrolyzing activity in addition to its transamidating function. Studies show that TG2 is a player in mediating cell death processes. However, there is far from a consensus about the role of this enzyme in cell death processes as it appears to be dependent upon the cell type, stimuli, subcellular localization and conformational state of the enzyme. The purpose of this study was to dissect the role of TG2 in the cell death processes. To this end, we created and characterized 4 distinct point mutants of TG2, each of which differs from the wild type by its conformation or by lacking an important function. We also prepared these mutants as nuclear targeted proteins. By overexpressing mutant or wild type forms of TG2 in HEK 293 cells, we investigated the modulatory role of the protein in the cell death process in response to three stressors: thapsigargin, hyperosmotic stress and oxygen/glucose deprivation (OGD). All of the TG2 constructs, except the R580A mutant (which cannot bind guanine nucleotides and is therefore more prone to exhibit transamidating activity), either did not significantly affect the cell death processes or were protective. However in the case of the R580A mutant, cell death in response to high thapsigargin concentrations, was significantly increased. Intriguingly, nuclear localization of R580A-TG2 was sufficient to counteract the pro-death role of cytoplasmic R580A-TG2. In addition, nuclear localization of TG2 significantly facilitated its protective role against OGD. Our data support the hypothesis that the transamidation activity of TG2, which is mostly quiescent except in extreme stress conditions, is necessary for its pro-death role. In addition, nuclear localization of TG2 generally plays a key role in its protective function against cell death processes, either counteracting the detrimental effect or strengthening the protective role of the protein.
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Affiliation(s)
- Soner Gundemir
- Department of Pharmacology and Physiology, University of Rochester, Rochester, New York, United States of America
| | - Gail V. W. Johnson
- Department of Pharmacology and Physiology, University of Rochester, Rochester, New York, United States of America
- Department of Anesthesiology, University of Rochester, Rochester, New York, United States of America
- * E-mail:
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110
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Anjum N, Baker PN, Robinson NJ, Aplin JD. Maternal celiac disease autoantibodies bind directly to syncytiotrophoblast and inhibit placental tissue transglutaminase activity. Reprod Biol Endocrinol 2009; 7:16. [PMID: 19228395 PMCID: PMC2649929 DOI: 10.1186/1477-7827-7-16] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/08/2008] [Accepted: 02/19/2009] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Celiac disease (CD) occurs in as many as 1 in 80 pregnant women and is associated with poor pregnancy outcome, but it is not known if this is an effect on maternal nutrient absorption or, alternatively, if the placenta is an autoimmune target. The major autoantigen, tissue transglutaminase (tTG), has previously been shown to be present in the maternal-facing syncytiotrophoblast plasma membrane of the placenta. METHODS ELISA was used to demonstrate the presence of antibodies to tissue transglutaminase in a panel of CD sera. Immunohistochemistry was used to evaluate the binding of IgA autoantibodies from CD serum to term placenta. In addition, novel direct binding and activity assays were developed to mimic the in vivo exposure of the villous placenta to maternal autoantibody. RESULTS AND DISCUSSION CD IgA autoantibodies located to the syncytial surface of the placenta significantly more than IgA antibodies in control sera (P < 0.0001). The distribution of antigen was similar to that observed using a monoclonal antibody to tissue transglutaminase. Staining was reduced by pre-absorption of CD serum with recombinant human tissue transglutaminase. In direct binding assays, autoimmune immunoglobulin A (IgA) from the maternal compartment became associated with antigen at the syncytial surface of the placenta, as a result of which transglutaminase activity at this site was inhibited. CONCLUSION These data indicate that direct immune effects in untreated CD women may compromise placental function.
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Affiliation(s)
- Naheed Anjum
- Maternal and Fetal Health Research Group, University of Manchester, Research Floor, St Mary's Hospital, Manchester, M13 0JH, UK
| | - Philip N Baker
- Maternal and Fetal Health Research Group, University of Manchester, Research Floor, St Mary's Hospital, Manchester, M13 0JH, UK
| | - Nicola J Robinson
- Maternal and Fetal Health Research Group, University of Manchester, Research Floor, St Mary's Hospital, Manchester, M13 0JH, UK
| | - John D Aplin
- Maternal and Fetal Health Research Group, University of Manchester, Research Floor, St Mary's Hospital, Manchester, M13 0JH, UK
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111
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Zhang Z, Xing J, Ma L, Gong R, Chin YE, Zhuang S. Transglutaminase-1 regulates renal epithelial cell proliferation through activation of Stat-3. J Biol Chem 2009; 284:3345-3353. [PMID: 19049964 PMCID: PMC2631946 DOI: 10.1074/jbc.m808396200] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2008] [Indexed: 01/21/2023] Open
Abstract
Transglutaminase-1 (TGase-1) is a Ca(2+)-dependent enzyme capable of cross-linking a variety of proteins and promoting wound healing in the skin. In this study, we examined the role of TGase-1 in proliferation of renal proximal tubular cells (RPTC). TGase-1, but not TGase-2, -5, and -7, was expressed in RPTC. Treatment with monodansylcadarevine (MDC), a selective TGase inhibitor or down-regulation of TGase-1 with small interfering RNA (siRNA) decreased RPTC proliferation. Proliferation of RPTC was accompanied by activation of Akt and Stat-3 (signal transducer and activator of transcription-3). Treatment with MDC or TGase-1 siRNA decreased Stat-3 but not Akt phosphorylation. Further studies showed that the Janus-activated kinase 2 (JAK2) mediates phosphorylation of Stat-3, and knockdown of either JAK2 or Stat-3 by siRNA decreased RPTC proliferation. However, inhibition of TGase-1 decreased phosphorylation of Stat-3 but not JAK2. Overexpression of Stat-3, JAK2, and/or TGase-1 in RPTC revealed that JAK2 is indispensable for TGase-1 to induce Stat-3 phosphorylation and TGase-1 potentiates JAK2-induced Stat-3 phosphorylation. Consistent with these observations, we found that inhibition of TGase-1 and the JAK2-Stat-3 signaling pathway decreased the transcriptional activity of Stat-3 and expression of the Stat-3-targeted genes, cyclin D1 and cyclin E. Conversely, overexpresssion of TGase-1 enhanced the JAK2-dependent transcriptional activity of Stat-3. Finally, TGase-1 was found to interact with JAK2, and this interaction was inhibited by MDC. These results demonstrate that TGase-1 plays an important role in regulation of renal epithelial cell proliferation through the JAK2-Stat-3 signaling pathway.
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Affiliation(s)
- Zhu Zhang
- Department of Medicine, Brown University School of Medicine, Rhode Island Hospital, Providence, Rhode Island 02903
| | - Jingping Xing
- Department of Medicine, Brown University School of Medicine, Rhode Island Hospital, Providence, Rhode Island 02903
| | - Li Ma
- Department of Surgery, Brown University School of Medicine, Rhode Island Hospital, Providence, Rhode Island 02903
| | - Rujun Gong
- Department of Medicine, Brown University School of Medicine, Rhode Island Hospital, Providence, Rhode Island 02903
| | - Y Eugene Chin
- Department of Surgery, Brown University School of Medicine, Rhode Island Hospital, Providence, Rhode Island 02903
| | - Shougang Zhuang
- Department of Medicine, Brown University School of Medicine, Rhode Island Hospital, Providence, Rhode Island 02903.
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112
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Lai TS, Liu Y, Tucker T, Daniel KR, Sane DC, Toone E, Burke JR, Strittmatter WJ, Greenberg CS. Identification of chemical inhibitors to human tissue transglutaminase by screening existing drug libraries. ACTA ACUST UNITED AC 2008; 15:969-78. [PMID: 18804034 DOI: 10.1016/j.chembiol.2008.07.015] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2007] [Revised: 07/16/2008] [Accepted: 07/23/2008] [Indexed: 12/20/2022]
Abstract
Human tissue transglutaminase (TGM2) is a calcium-dependent crosslinking enzyme involved in the posttranslational modification of intra- and extracellular proteins and implicated in several neurodegenerative diseases. To find specific inhibitors to TGM2, two structurally diverse chemical libraries (LOPAC and Prestwick) were screened. We found that ZM39923, a Janus kinase inhibitor, and its metabolite ZM449829 were the most potent inhibitors with IC(50) of 10 and 5 nM, respectively. In addition, two other inhibitors, including tyrphostin 47 and vitamin K(3), were found to have an IC(50) in the micromolar range. These agents used in part a thiol-dependent mechanism to inhibit TGM2, consistent with the activation of TGM2 by reduction of an intramolecular disulfide bond. These inhibitors were tested in a polyglutamine-expressing Drosophila model of neurodegeneration and found to improve survival. The TGM2 inhibitors we discovered may serve as valuable lead compounds for the development of orally active TGM2 inhibitors to treat human diseases.
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Affiliation(s)
- Thung-S Lai
- Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA.
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113
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Transglutaminase 2 cross-linking of matrix proteins: biological significance and medical applications. Amino Acids 2008; 36:659-70. [PMID: 18982407 DOI: 10.1007/s00726-008-0190-y] [Citation(s) in RCA: 104] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2008] [Accepted: 10/07/2008] [Indexed: 12/22/2022]
Abstract
This review summarises the functions of the enzyme tissue transglutaminase (TG2) in the extracellular matrix (ECM) both as a matrix stabiliser through its protein cross-linking activity and as an important cell adhesion protein involved in cell survival. The contribution of extracellular TG2 to the pathology of important diseases such as cancer and fibrosis are discussed with a view to the potential importance of TG2 as a therapeutic target. The medical applications of TG2 are further expanded by detailing the use of transglutaminase cross-linking in the development of novel biocompatible biomaterials for use in soft and hard tissue repair.
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114
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Hwang JY, Mangala LS, Fok JY, Lin YG, Merritt WM, Spannuth WA, Nick AM, Fiterman DJ, Vivas-Mejia PE, Deavers MT, Coleman RL, Lopez-Berestein G, Mehta K, Sood AK. Clinical and biological significance of tissue transglutaminase in ovarian carcinoma. Cancer Res 2008; 68:5849-58. [PMID: 18632639 DOI: 10.1158/0008-5472.can-07-6130] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Tissue type transglutaminase (TG2) is a unique multifunctional protein that plays a role in many steps in the cancer metastatic cascade. Here, we examined the clinical (n = 93 epithelial ovarian cancers) and biological (in vitro adhesion, invasion, and survival and in vivo therapeutic targeting) significance of TG2 in ovarian cancer. The overexpression of TG2 was associated with significantly worse overall patient survival in both univariate and multivariate analyses. Transfection of TG2 into SKOV3ip1 cells promoted attachment and spreading on fibronectin-coated surfaces and increased the in vitro invasive potential of these cells. Conversely, TG2 silencing with small interfering RNA (siRNA) of HeyA8 cells significantly decreased the invasive potential of the cells and also increased docetaxel-induced cell death. In vivo therapy experiments using chemotherapy-sensitive (HeyA8) and chemotherapy-resistant (HeyA8-MDR and RMG2) models showed significant antitumor activity both with TG2 siRNA-1,2-dioleoyl-sn-glycero-3-phosphatidylcholine alone and in combination with docetaxel chemotherapy. This antitumor activity was related to decreased proliferation and angiogenesis and increased tumor cell apoptosis in vivo. Taken together, these findings indicate that TG2 overexpression is an adverse prognostic factor in ovarian carcinoma and TG2 targeting may be an attractive therapeutic approach.
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Affiliation(s)
- Jee Young Hwang
- Department of Gynecologic Oncology, The University of Texas M. D. Anderson Cancer Center, Houston, Texas 77030, USA
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115
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Tissue transglutaminase in celiac disease: role of autoantibodies. Amino Acids 2008; 36:693-9. [PMID: 18600381 DOI: 10.1007/s00726-008-0120-z] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2008] [Accepted: 05/25/2008] [Indexed: 12/13/2022]
Abstract
In celiac disease (CD), gluten, the disease-inducing toxic component in wheat, induces the secretion of IgA-class autoantibodies which target tissue transglutaminase (tTG). These autoantibodies are produced in the small-intestinal mucosa, and, during gluten consumption, they can also be detected in patients' serum but disappear slowly from the circulation on a gluten-free diet. Interestingly, after adoption of a gluten-free diet the serum autoantibodies disappear from the circulation more rapidly than the small-intestinal mucosal autoantibody deposits. The finding of IgA deposits on extracellular tTG in the liver, kidney, lymph nodes and muscles of patients with CD indicates that tTG is accessible to the gut-derived autoantibodies. Although the specific autoantibody response directed against tTG is very characteristic in celiac patients, their role in the immunopathology of the celiac mucosal lesion is a matter of debate. Here we report a brief summary of anti-tTG antibody effects demonstrating that these antibodies are functional and not mere bystanders in the disease pathogenesis. In fact, they inhibit intestinal epithelial cell differentiation, induce intestinal epithelial cell proliferation, increase epithelial permeability and activate monocytes and disturb angiogenesis.
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116
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Transglutaminases and their substrates in biology and human diseases: 50 years of growing. Amino Acids 2008; 36:599-614. [DOI: 10.1007/s00726-008-0124-8] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2008] [Accepted: 05/15/2008] [Indexed: 12/19/2022]
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117
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Mehta K. Biological and therapeutic significance of tissue transglutaminase in pancreatic cancer. Amino Acids 2008; 36:709-16. [PMID: 18594944 DOI: 10.1007/s00726-008-0128-4] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2008] [Accepted: 05/10/2008] [Indexed: 12/18/2022]
Abstract
Pancreatic ductal adenocarcinoma (PDA) is one of the deadliest cancers world-wide with an estimated annual incidence and mortality rates of approximately 6,500 cases in the UK, over 40,000 cases in Europe, 19,000 cases in Japan and over 30,000 cases in the United States. Difficulty to diagnose the disease at an early stage, rapid progression and intrinsic resistance to currently available therapies are major factors that contribute to poor disease outcome in these patients (overall 5 years survival, <3%). Identification of cancer cell-encoded genes that contribute to the development of intrinsic resistance and metastatic spread of the PDA tumors, may yield immediate clinical benefits in terms of revealing new therapeutic targets for effective treatment of the disease. This article discusses the significance of tissue-type transglutaminase (TG2) whose expression is elevated in the majority of PDA tumors and cell lines. Based on the published data and the results discussed in this review, TG2 appears to be a promising target for containment and treatment of this formidable disease.
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Affiliation(s)
- K Mehta
- Department of Experimental Therapeutics, The University of Texas M. D. Anderson Cancer Center, 1515 Holcombe Blvd., Unit 362, Houston, TX 77030, USA.
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118
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Transdab wiki: the interactive transglutaminase substrate database on web 2.0 surface. Amino Acids 2008; 36:615-7. [PMID: 18594947 DOI: 10.1007/s00726-008-0121-y] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2008] [Accepted: 04/26/2008] [Indexed: 10/21/2022]
Abstract
TRANSDAB wiki is a database of transglutaminase substrate proteins. This wiki is designed to provide quality content of all the details (including synonyms, structures, references) about transglutaminase substrate proteins and interaction partners. Currently TRANSDAB contains 243 articles about substrate proteins for 6 transglutaminase types in a user-friendly, editable format. Our aim was to collect structural information about substrate proteins and this information is provided in form of images, videos and links. The scientific community is invited to edit the database and besides providing up-to-date information, this wiki should serve as a platform for valuable discussions.
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119
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Verma A, Guha S, Diagaradjane P, Kunnumakkara AB, Sanguino AM, Lopez-Berestein G, Sood AK, Aggarwal BB, Krishnan S, Gelovani JG, Mehta K. Therapeutic significance of elevated tissue transglutaminase expression in pancreatic cancer. Clin Cancer Res 2008; 14:2476-83. [PMID: 18413840 DOI: 10.1158/1078-0432.ccr-07-4529] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
PURPOSE Tissue transglutaminase (TG2) is a multifunctional protein that is implicated in development of drug resistance and metastasis. Therefore, we examined therapeutic targeting of TG2 for inhibiting growth and metastasis of in vivo growing pancreatic ductal adenocarcinoma (PDAC) in nude mice. EXPERIMENTAL DESIGN We implanted Panc-28 pancreatic cancer cells to induce orthotopic PDAC tumors in nude mice and determined the efficacy of liposomal TG2 small interfering RNA (siRNA) either alone or in combination with gemcitabine. RESULTS We show that down-regulation of endogenous TG2 by siRNA could effectively block the growth of PDAC. Moreover, down-regulation of TG2 significantly enhanced the therapeutic efficacy of gemcitabine against PDAC and inhibited metastatic spread of the disease. The antitumor activity was related to inhibition of proliferation, angiogenesis, and Akt phosphorylation. CONCLUSION siRNA-mediated down-regulation of TG2 represents a promising therapeutic approach for improved treatment of PDAC.
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Affiliation(s)
- Amit Verma
- Department of Experimental Therapeutics, The University of Texas M. D. Anderson Cancer Center, Houston, TX 77030, USA
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120
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Identification of new amine acceptor protein substrate candidates of transglutaminase in rat liver extract: use of 5-(biotinamido) pentylamine as a probe. Biosci Biotechnol Biochem 2008; 72:1056-62. [PMID: 18391459 DOI: 10.1271/bbb.70796] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Transglutaminases (TGs) are a family of enzymes that catalyze Ca(2+)-dependent post-translational modification of proteins by introducing protein-protein crosslinks (between specific glutamine and lysine residues), amine incorporation, and site-specific deamidation. In this study, new amine acceptor protein substrates of TG were isolated from rat liver extract and identified using 5-(biotinamido) pentylamine, a biotinylated primary amine substrate, as a probe. TG protein substrate candidates labeled with biotin by endogenous TG activity were isolated and recovered by avidin column chromatography. Proteins with molecular masses of 40, 42, and 45 kDa were the main components of the labeled proteins. Determination of their partial amino acid sequences and immunoblotting analyses were done to identify them. The 45-kDa protein was identical with betaine-homocysteine S-methyltransferase (EC 2.2.2.5), which was identified in our previous study. The 40- and 42-kDa proteins were identified as arginase-I (EC 3.5.3.1) and fructose-1,6-bisphosphatase (EC 3.1.3.11) respectively. TG catalyzed incorporation of 5-(biotinamido) pentylamine into both arginase-I and fructose-1,6-bisphosphatase purified from rat liver was confirmed in vitro. These results suggest that these two enzymes are the new protein substrate candidates of TG and that they can be modified post-translationally by cellular TG.
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121
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Verma A, Guha S, Wang H, Fok JY, Koul D, Abbruzzese J, Mehta K. Tissue Transglutaminase Regulates Focal Adhesion Kinase/AKT Activation by Modulating PTEN Expression in Pancreatic Cancer Cells. Clin Cancer Res 2008; 14:1997-2005. [DOI: 10.1158/1078-0432.ccr-07-1533] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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122
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Filiano AJ, Bailey CDC, Tucholski J, Gundemir S, Johnson GVW. Transglutaminase 2 protects against ischemic insult, interacts with HIF1beta, and attenuates HIF1 signaling. FASEB J 2008; 22:2662-75. [PMID: 18375543 DOI: 10.1096/fj.07-097709] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Transglutaminase 2 (TG2) is a multifunctional enzyme that has been implicated in the pathogenesis of neurodegenerative diseases, ischemia, and stroke. The mechanism by which TG2 modulates disease progression have not been elucidated. In this study we investigate the role of TG2 in the cellular response to ischemia and hypoxia. TG2 is up-regulated in neurons exposed to oxygen and glucose deprivation (OGD), and increased TG2 expression protects neurons against OGD-induced cell death independent of its transamidating activity. We identified hypoxia inducible factor 1beta (HIF1beta) as a TG2 binding partner. HIF1beta and HIF1alpha together form the heterodimeric transcription factor hypoxia inducible factor 1 (HIF1). TG2 and the transaminase-inactive mutant C277S-TG2 inhibited a HIF-dependent transcription reporter assay under hypoxic conditions without affecting nuclear protein levels for HIF1alpha or HIF1beta, their ability to form the HIF1 heterodimeric transcription factor, or HIF1 binding to its DNA response element. Interestingly, TG2 attenuates the up-regulation of the HIF-dependent proapoptotic gene Bnip3 in response to OGD but had no effect on the expression of VEGF, which has been linked to prosurvival processes. This study demonstrates for the first time that TG2 protects against OGD, interacts with HIF1beta, and attenuates the HIF1 hypoxic response pathway. These results indicate that TG2 may play an important role in protecting against the delayed neuronal cell death in ischemia and stroke.
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Affiliation(s)
- Anthony J Filiano
- Department of Cell Biology, University of Alabama at Birmingham, Birmingham, Alabama, USA
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123
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Ivanov AI. Pharmacological inhibition of endocytic pathways: is it specific enough to be useful? Methods Mol Biol 2008; 440:15-33. [PMID: 18369934 DOI: 10.1007/978-1-59745-178-9_2] [Citation(s) in RCA: 453] [Impact Index Per Article: 28.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
Abstract
Eukaryotic cells constantly form and internalize plasma membrane vesicles in a process known as endocytosis. Endocytosis serves a variety of housekeeping and specialized cellular functions, and it can be mediated by distinct molecular pathways. Among them, internalization via clathrin-coated pits, lipid raft/caveolae-mediated endocytosis and macropinocytosis/phagocytosis are the most extensively characterized. The major endocytic pathways are usually distinguished on the basis of their differential sensitivity to pharmacological/chemical inhibitors, although the possibility of nonspecific effects of such inhibitors is frequently overlooked. This review provides a critical evaluation of the selectivity of the most widely used pharmacological inhibitors of clathrin-mediated, lipid raft/caveolae-mediated endocytosis and macropinocytosis/phagocytosis. The mechanisms of actions of these agents are described with special emphasis on their reported side effects on the alternative internalization modes and the actin cytoskeleton. The most and the least-selective inhibitors of each major endocytic pathway are highlighted.
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Affiliation(s)
- Andrei I Ivanov
- Department of Medicine, Gastroenterology and Hepatology Division, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
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124
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Satpathy M, Cao L, Pincheira R, Emerson R, Bigsby R, Nakshatri H, Matei D. Enhanced Peritoneal Ovarian Tumor Dissemination by Tissue Transglutaminase. Cancer Res 2007; 67:7194-202. [PMID: 17671187 DOI: 10.1158/0008-5472.can-07-0307] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Tissue transglutaminase (TG2) is involved in Ca(2+)-dependent aggregation and polymerization of proteins. We previously reported that TG2 mRNA is up-regulated in epithelial ovarian cancer (EOC) cells compared with normal ovarian epithelium. Here, we show overexpression of the TG2 protein in ovarian cancer cells and tumors and its secretion in ascites fluid and define its role in EOC. By stable knockdown and overexpression, we show that TG2 enhances EOC cell adhesion to fibronectin and directional cell migration. This phenotype is preserved in vivo, where the pattern of tumor dissemination in the peritoneal space is dependent on TG2 expression levels. TG2 knockdown diminishes dissemination of tumors on the peritoneal surface and mesentery in an i.p. ovarian xenograft model. This phenotype is associated with deficient beta(1) integrin-fibronectin interaction, leading to weaker anchorage of cancer cells to the peritoneal matrix. Highly expressed in ovarian tumors, TG2 facilitates i.p. tumor dissemination by enhancing cell adhesion to the extracellular matrix and modulating beta(1) integrin subunit expression.
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Affiliation(s)
- Minati Satpathy
- Department of Medicine, Indiana University School of Medicine, 535 Barnhill Drive, RT 473, Indianapolis, IN 46202, USA.
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125
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Siegel M, Khosla C. Transglutaminase 2 inhibitors and their therapeutic role in disease states. Pharmacol Ther 2007; 115:232-45. [PMID: 17582505 PMCID: PMC1975782 DOI: 10.1016/j.pharmthera.2007.05.003] [Citation(s) in RCA: 159] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2007] [Accepted: 05/03/2007] [Indexed: 02/06/2023]
Abstract
Transglutaminase 2 (TG2) is a multi-domain, multi-functional enzyme that post-translationally modifies proteins by catalyzing the formation of intermolecular isopeptide bonds between glutamine and lysine side-chains. It plays a role in diverse biological functions, including extracellular matrix formation, integrin-mediated signaling, and signal transduction involving 7-transmembrane receptors. While some of the roles of TG2 under normal physiological conditions remain obscure, the protein is believed to participate in the pathogenesis of several unrelated diseases, including celiac sprue, neurodegenerative diseases, and certain types of cancer. A variety of small molecule and peptidomimetic inhibitors of the TG2 active site have been identified. Here, we summarize the biochemistry, biology, pharmacology and medicinal chemistry of human TG2.
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Affiliation(s)
- Matthew Siegel
- Department of Chemical Engineering, Stanford University, Stanford, CA 94305
| | - Chaitan Khosla
- Department of Chemical Engineering, Stanford University, Stanford, CA 94305
- Department of Chemistry, Stanford University, Stanford, CA 94305
- Department of Biochemistry, Stanford University, Stanford, CA 94305
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126
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Verma A, Mehta K. Tissue transglutaminase-mediated chemoresistance in cancer cells. Drug Resist Updat 2007; 10:144-51. [PMID: 17662645 DOI: 10.1016/j.drup.2007.06.002] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2007] [Revised: 06/08/2007] [Accepted: 06/11/2007] [Indexed: 12/30/2022]
Abstract
Drug resistance and metastasis are major impediments for the successful treatment of cancer. A common feature among drug resistant and metastatic tumor cells is that they exhibit profound resistance to apoptosis. This property enables cancer cells not only to grow and survive in stressful environments (metastasis) but also to display resistance against many anticancer agents. Therefore, perturbation of the intrinsic apoptotic pathways of cancer cells will affect their ability to respond to chemotherapy and to metastasize and survive in distant sites. Recent studies have demonstrated that cancer cells and cancer cell lines selected for resistance against chemotherapeutic drugs or isolated from metastatic sites, express elevated levels of the multifunctional protein, tissue transglutaminase (TG2). TG2 is the most diverse and ubiquitous member of the transglutaminase family of proteins that is implicated to play a role in apoptosis, wound healing, cell migration, cell attachment, cell growth, angiogenesis, and matrix assembly. TG2 can associate with certain beta members of the integrin family of proteins (beta1, beta3, beta4, and beta5) and promote stable interaction between cells and the extracellular matrix (ECM), resulting in increased cell survival, cell migration, and invasion. Additionally, TG2 forms a ternary complex with IkappaB/p65:p50 and results in constitutive activation of the nuclear transcription factor-kappaB (NF-kappaB). Moreover, TG2 expression in cancer cells leads to constitutive activation of the focal adhesion kinase (FAK) and its downstream PI3K/Akt survival pathway. Importantly, the inhibition of endogenous TG2 by small interfering RNA (siRNA) resulted in the reversal of drug resistance and the invasive phenotype. Conversely, ectopic expression of TG2 promoted cell survival, cell motility and invasive functions of cancer cells. This review discusses the current thinking and implications of increased TG2 expression in development of drug resistance and metastasis by cancer cells.
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Affiliation(s)
- Amit Verma
- Department of Experimental Therapeutics, Unit 362, The University of Texas M. D. Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, TX 77030, United States
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127
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Alford SC, Bazowski J, Lorimer H, Elowe S, Howard PL. Tissue transglutaminase clusters soluble A-type ephrins into functionally active high molecular weight oligomers. Exp Cell Res 2007; 313:4170-9. [PMID: 17707797 DOI: 10.1016/j.yexcr.2007.07.019] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2007] [Revised: 07/17/2007] [Accepted: 07/19/2007] [Indexed: 11/20/2022]
Abstract
The Eph receptors and their ligands, the ephrins, are thought to act at points of close cell-cell contact to elicit bi-directional signaling in receptor and ligand expressing cells. However, when cultured in vitro, some A-type ephrins are released from the cell surface and it is unclear if these soluble ephrins participate in Eph receptor activation. We show that soluble ephrin A5 is subject to oligomerization. Ephrins A1 and A5 are substrates for a cross-linking enzyme, tissue transglutaminase, which mediates the formation of oligomeric ephrin. Transglutaminase-cross-linked ephrin binds to A-type Eph receptors, stimulates Eph kinase activity, and promotes invasion and migration of HeLa cells. Transglutaminase-mediated oligomerization of soluble ephrin potentially represents a novel mechanism of forward signaling through Eph receptors and may extend the influence of A-type ephrins beyond cell contact mediated signaling.
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Affiliation(s)
- Spencer C Alford
- Centre for Biomedical Research, University of Victoria, PO Box 3020 Station CSC Victoria, BC, Canada V8W 3N5
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128
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Robinson NJ, Baker PN, Jones CJP, Aplin JD. A role for tissue transglutaminase in stabilization of membrane-cytoskeletal particles shed from the human placenta. Biol Reprod 2007; 77:648-57. [PMID: 17625111 DOI: 10.1095/biolreprod.107.061747] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Tissue transglutaminase (TGM2; also known as TG2 or tTG) localizes to the syncytial microvillous membrane (MVM) of the human placenta, the primary interface between maternal and fetal tissue. To identify TGM2 substrates in the MVM, membrane vesicles were prepared and labeled with biotinylated acyl donor or acceptor probes. Biotinylated species were selected on an avidin affinity matrix and identified by mass spectrometry of tryptic peptides. The most abundant were cytoskeletal (actin, tubulin, and cytokeratin) and membrane-associated (annexins, integrins, and placental alkaline phosphatase) proteins. During pregnancy, apoptotic particulate material, the end product of the trophoblast life cycle, is shed from the MVM into maternal circulation. Shed material was isolated from primary trophoblast cultures in which syncytial-like masses develop by fusion. A substantial fraction of actin in the particles was in the form of covalent polymeric aggregates, in contrast to cellular actin, which dissociated completely into monomer in SDS-PAGE. When cells were cultured in the presence of transglutaminase inhibitors, actin in the shed particles remained exclusively in monomeric form, and a reduction in trophoblast intercellular fusion and differentiation was observed. These findings suggest that transglutaminase-mediated cross-linking stabilizes the particulate material shed from the placenta.
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Affiliation(s)
- Nicola J Robinson
- Maternal and Fetal Health Research Centre, Division of Human Development, University of Manchester, St. Mary's Hospital, Manchester M13 0JH, United Kingdom
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129
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Lai TS, Liu Y, Li W, Greenberg CS. Identification of two GTP-independent alternatively spliced forms of tissue transglutaminase in human leukocytes, vascular smooth muscle, and endothelial cells. FASEB J 2007; 21:4131-43. [PMID: 17609251 PMCID: PMC2157556 DOI: 10.1096/fj.06-7598com] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Tissue transglutaminase (tTG) is a multifunctional enzyme with transglutaminase crosslinking (TGase), GTP binding, and hydrolysis activities that play a role in many different disorders. We identified, characterized, and investigated the function and stability of two alternatively spliced forms of tTG using biochemical, cellular, and molecular biological approaches. Using a human aortic vascular smooth muscle cells (VSMC) cDNA library, we identified two cDNAs encoding C-terminal truncated forms, tTG(V1) and tTG(V2). tTG(V1,2) mRNAs were synthesized by a rare splicing event using alternate splice sites within exons 12 and 13 of the tTG gene, respectively. Quantitative PCR and immunoblotting demonstrated that there was unique expression and localization of tTG(V1,2) compared with tTG in human umbilical vein endothelial cells (HUVECs), VSMC, and leukocytes. The loss of C-terminal 52 amino acid residues (AAs) in tTG(V1,2) altered GTP binding, enhanced GTP hydrolysis, rendered the variants insensitive to GTP inhibition, and resulted in <10% residual Ca(+2)-dependent TGase activity. Transfection in HEK293 demonstrated a 28- and 5-fold reduction in the expression of tTG(V1) and tTG(V2), respectively, demonstrating that the C-terminal GTP-binding domain is important in stabilizing and promoting the half-life of tTG. The altered affinity for GTP allowed tTG(V1,2) to exhibit enhanced TGase activity when there is a transient increase in Ca(+2) levels. The abundance of tTG(V1,2) and its distinct intracellular expression patterns in human vascular cells and leukocytes indicate these isoforms likely have unique physiological functions.
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Affiliation(s)
- Thung-S Lai
- Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA
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130
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Mishra S, Melino G, Murphy LJ. Transglutaminase 2 kinase activity facilitates protein kinase A-induced phosphorylation of retinoblastoma protein. J Biol Chem 2007; 282:18108-18115. [PMID: 17478427 DOI: 10.1074/jbc.m607413200] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Transglutaminase 2 (TG2, tissue transglutaminase) is a multifunctional protein involved in cross-linking a variety of proteins, including retinoblastoma protein (Rb). Here we show that Rb is also a substrate for the recently identified serine/threonine kinase activity of TG2 and that TG2 phosphorylates Rb at the critically important Ser780 residue. Furthermore, phosphorylation of Rb by TG2 destabilizes the Rb.E2F1 complex. TG2 phosphorylation of Rb was abrogated by high Ca2+ concentrations, whereas TG2 transamidating activity was inhibited by ATP. TG2 was itself phosphorylated by protein kinase A (PKA). Phosphorylation of TG2 by PKA attenuated its transamidating activity and enhanced its kinase activity. Activation of PKA in mouse embryonic fibroblasts (MEF) with dibutyryl-cAMP enhanced phosphorylation of both TG2 and Rb by a process that was inhibited by the PKA inhibitor H89. Treatment with dibutyryl-cAMP enhanced Rb phosphorylation in MEFtg2+/+ cells but not in MEFtg2-/- cells. These data indicate that Rb is a substrate for TG2 kinase activity and suggest that phosphorylation of Rb, which results from activation of PKA in fibroblasts, is indirect and requires TG2 kinase activity.
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Affiliation(s)
- Suresh Mishra
- Departments of Physiology and Internal Medicine, University of Manitoba, Winnipeg R3E 0W3, Canada.
| | - Gerry Melino
- Department of Biochemistry Laboratory, Instituto Dermapatico dell'Immaculata-Institute for Hospitalization, Care and Scientific Research, Department of Experimental Medicine and Biological Sciences, University of Rome, 00133 Tor Vergata, Italy
| | - Liam J Murphy
- Departments of Physiology and Internal Medicine, University of Manitoba, Winnipeg R3E 0W3, Canada
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131
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Tanaka K, Yokosaki Y, Higashikawa F, Saito Y, Eboshida A, Ochi M. The integrin alpha5beta1 regulates chondrocyte hypertrophic differentiation induced by GTP-bound transglutaminase 2. Matrix Biol 2007; 26:409-18. [PMID: 17490870 DOI: 10.1016/j.matbio.2007.04.005] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2007] [Revised: 04/06/2007] [Accepted: 04/09/2007] [Indexed: 11/22/2022]
Abstract
Soluble GTP-bound transglutaminase 2 (TG2) induces hypertrophic differentiation in chondrocyte cultures in a beta1 integrin-dependent fashion. beta1 integrin subfamily consists of 12 heterodimers with 12 different alpha subunits and a beta1 subunit. To identify the specific integrin heterodimer(s) responsible for this process, we specifically blocked individual beta1 integrins on the CH-8 immortalized human chondrocytes during hypertrophic differentiation. Blockade of alpha5beta1 inhibited matrix metalloproteinase 13 (MMP-13), type X collagen expression, alkaline phosphatase activity and matrix calcification by 30-50% associated with weak effects of anti-alpha3beta1 and -alpha4beta1. Anti-alpha1beta1, -alpha2beta1 and -alpha6beta1 had no effect. To examine whether the dominant effect of integrin alpha5beta1 was due to a direct interaction with TG2, we incubated the chondrocytic cells on plates coated with GTP-bound TG2. The immobilized GTP-bound TG2 induced hypertrophic differentiation to the same extent as the soluble GTP-bound TG2, which was also inhibited by anti-alpha5beta1. CH-8 cells grown on plates coated with GTP-bound TG2 demonstrated adherence associated with focal adhesion kinase phosphorylation. These properties were inhibited by anti-alpha5beta1. Furthermore, engagement of alpha5beta1 on CH-8 cells via anti-alpha5beta1 antibody did, in fact, induce differentiation. Although CH-8 cells adhered to GTP-free TG2 via integrin alpha5beta1, the cells failed to undergo hypertrophic differentiation. Thus, integrin alpha5beta1 is critical for the chondrocyte hypertrophic differentiation induced by GTP-bound TG2, and this induction is ligand dependent.
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Affiliation(s)
- Kumi Tanaka
- Department of Orthopedics, Hiroshima University, 1-2-3 Kasumi, Minamiku, Hiroshima, 734-8551, Japan
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132
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Wang Y, Lam KSL, Lam JBB, Lam MC, Leung PTY, Zhou M, Xu A. Overexpression of Angiopoietin-Like Protein 4 Alters Mitochondria Activities and Modulates Methionine Metabolic Cycle in the Liver Tissues of db/db Diabetic Mice. Mol Endocrinol 2007; 21:972-86. [PMID: 17213385 DOI: 10.1210/me.2006-0249] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Angiopoietin-like protein 4 (ANGPTL4) is a circulating protein predominantly produced from fat tissue and liver. Recent data from others and our laboratory have demonstrated this protein to be an important player in energy metabolism and insulin sensitivity. However, the molecular mechanisms underlying its metabolic actions remain elusive. In this study, we have employed a two-dimensional fluorescence difference gel electrophoresis technique to study the protein profiles in the livers of db/db mice treated with or without ANGPTL4. When compared with those of lean mice, 118 proteins were found to be up- or down-regulated in db/db mice. Adenovirus-mediated overexpression of ANGPTL4 could reverse a large portion of the up- or down-regulated proteins to control levels. Especially, a number of mitochondria proteins were down-regulated by ANGPTL4 to a great extent. Chronic treatment with ANGPTL4 resulted in an elevated activity of mitochondria respiratory chain complexes II-III and IV in db/db mice. Additionally, several key enzymes in the methionine/homocysteine metabolic cycle were found to be increased in db/db diabetic mice but decreased by ANGPTL4 treatment. HPLC analysis consistently revealed that ANGPTL4 could significantly restore the augmented S-adenosylmethionine levels and S-adenosylmethionine/S-adenosylhomocysteine ratios in livers of db/db mice. In summary, our results suggest that ANGPTL4 might elicit its metabolic effects through modulating the mitochondria functions and methionine metabolic cycles in the liver tissue.
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Affiliation(s)
- Yu Wang
- Genome Research Center, Faculty of Medicine Building, the University of Hong Kong, 21 Sassoon Road, Pokfulam, Hong Kong Special Administrative Region, China.
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133
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Shaoul R, Lerner A. Associated autoantibodies in celiac disease. Autoimmun Rev 2007; 6:559-65. [PMID: 17854749 DOI: 10.1016/j.autrev.2007.02.006] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2007] [Accepted: 02/14/2007] [Indexed: 11/30/2022]
Abstract
Celiac disease (CD) is a life-long inflammatory autoimmune condition of the gastrointestinal tract affecting genetically susceptible individuals. Several autoimmune disorders are more prevalent in patients and their close relatives and that risk is gluten exposure duration related. The most frequent reported CD associated conditions are type 1 diabetes mellitus and autoimmune thyroiditis. Associated autoimmune antibodies are frequent in CD and their first-degree relatives, spanning anti-endocrine, anti-gastrointestinal, anti-nuclear, anti-cytoskeleton and anti-neurological antibodies. More specifically, antibodies against thyroid and the endocrine pancreas, anti-gastric and liver, anti-nuclear constituents, anti-reticulin, actin, smooth muscle, calreticulin, desmin, collagens and bone, anti-brain, ganglioside, neuronal and blood vessel were described in sera of the patients in numerous studies. The common immunogenetic theories for the above associations are: sharing common HLA and non-HLA genes, antigenic mimicry, damage-induced neoantigen exposure, altered intestinal permeability, idiotype network dysregulation and epitope spreading. The CD associated autoantibodies enigma, being an epiphenomenon or pathogenic, remains unresolved and presents a challenging area for future research.
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Affiliation(s)
- Ron Shaoul
- Department of Pediatrics, Bnai Zion Medical Center, Haifa, Israel
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Sane DC, Kontos JL, Greenberg CS. Roles of transglutaminases in cardiac and vascular diseases. FRONT BIOSCI-LANDMRK 2007; 12:2530-45. [PMID: 17127261 PMCID: PMC2762549 DOI: 10.2741/2253] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
All transglutaminases share the common enzymatic activity of transamidation, or the cross-linking of glutamine and lysine residues to form N epsilon (gamma-glutamyl) lysyl isopeptide bonds. The plasma proenzyme factor XIII is responsible for stabilizing the fibrin clot against physical and fibrinolytic disruption. Another member of the transglutaminase family, tissue transglutaminase or TG2 is abundantly expressed in cardiomyocytes, vascular cells and macrophages. The transglutaminases have a variety of functions independent of their transamidating activity. For example, TG2 binds and hydrolyzes GTP, thereby fostering signal transduction by several G protein coupled receptors. Accumulating evidence points to novel roles for factor XIII and TG2 in cardiovascular biology including: (a) modulating platelet activity, (b) regulating glucose control, (c) contributing to the development of hypertension, (d) influencing the progression of atherosclerosis, (e) regulating vascular permeability and angiogenesis (f) and contributing to myocardial signaling, contractile activity and ischemia/reperfusion injury. In this review, we summarize the cardiovascular biology of two members of the family of transglutaminases, Factor XIII and TG2.
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Affiliation(s)
- David C Sane
- Wake Forest University School of Medicine, Medical Center Blvd., Winston-Salem, NC 27157-1045, USA.
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135
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Mangala LS, Fok JY, Zorrilla-Calancha IR, Verma A, Mehta K. Tissue transglutaminase expression promotes cell attachment, invasion and survival in breast cancer cells. Oncogene 2006; 26:2459-70. [PMID: 17043648 DOI: 10.1038/sj.onc.1210035] [Citation(s) in RCA: 128] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Distant metastasis is frequently observed in patients with breast cancer and is a major cause of cancer-related deaths in these patients. Currently, very little is known about the mechanisms that underlie the development of the metastatic phenotype in breast cancer cells. We previously found that metastatic breast cancer cells express high levels of tissue transglutaminase (TG2), but established no direct link between TG2 and metastasis. In this study, we hypothesized that TG2 plays a role in conferring the metastatic phenotype to breast cancer cells. The results obtained suggested that increased expression of TG2 in breast cancer cells contributes to their increased survival, invasion and motility. We further found that TG2 protein in a metastatic breast cancer MDA-MB231 cells was present on the cell surface in close association with integrins beta1, beta4 and beta5. Downregulation of endogenous TG2 by small interfering RNA inhibited fibronectin (Fn)-mediated cell attachment, survival and invasion. Conversely, ectopic expression of TG2 augmented invasion of breast cancer cells and attachment to Fn-coated surfaces. We conclude that TG2 expression in breast cancer cells plays an important role in the development of the metastatic phenotype.
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Affiliation(s)
- L S Mangala
- Department of Experimental Therapeutics - Unit 326, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
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136
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Fok JY, Ekmekcioglu S, Mehta K. Implications of tissue transglutaminase expression in malignant melanoma. Mol Cancer Ther 2006; 5:1493-503. [PMID: 16818508 DOI: 10.1158/1535-7163.mct-06-0083] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Human malignant melanoma is a highly aggressive form of cancer; the 5-year survival rate in patients with stage III or IV disease is <5%. In patients with metastatic melanoma, systemic therapy becomes ineffective because of the high resistance of melanoma cells to various anticancer therapies. We have found previously that development of the drug resistance and metastatic phenotypes in breast cancer cells is associated with increased tissue transglutaminase (TG2) expression. In the study reported here, we investigated TG2 expression and its implications in metastatic melanoma. We found that metastatic melanoma cell lines expressed levels of TG2 up to 24-fold higher than levels in radial growth phase of primary melanoma cell lines. Activation of endogenous TG2 by the calcium ionophore A23187 induced a rapid and strong apoptotic response in A375 cells and A23187-induced apoptosis could be blocked by TG2-specific inhibitors. These findings indicated that activation of endogenous TG2 could serve as a strategy for inducing apoptosis in malignant melanomas. Importantly, tumor samples from patients with malignant melanomas showed strong expression of TG2, suggesting that TG2 expression is selectively up-regulated during advanced developmental stages of melanoma. We observed that 20% to 30% of TG2 protein was present on cell membranes in association with beta1 and beta5 integrins. This association of TG2 with cell surface integrins promoted strong attachment of A375 cells to fibronectin-coated surfaces, resulting in increased cell survival in serum-free medium. Inhibition of TG2 by small interfering RNA inhibited fibronectin-mediated cell attachment and cell survival functions in A375 cells. Overall, our results suggest that TG2 expression contributes to the development of chemoresistance in malignant melanoma cells by exploiting integrin-mediated cell survival signaling pathways.
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Affiliation(s)
- Jansina Y Fok
- Department of Experimental Therapeutics, The University of Texas M.D. Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, TX 77030, USA
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137
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Balajthy Z, Csomós K, Vámosi G, Szántó A, Lanotte M, Fésüs L. Tissue-transglutaminase contributes to neutrophil granulocyte differentiation and functions. Blood 2006; 108:2045-54. [PMID: 16763214 DOI: 10.1182/blood-2004-02-007948] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
AbstractPromyelocytic NB4 leukemia cells undergo differentiation to granulocytes following retinoic acid treatment. Here we report that tissue transglutaminase (TG2), a protein cross-linking enzyme, was induced, then partially translocated into the nucleus, and became strongly associated with the chromatin during the differentiation process. The transglutaminase-catalyzed cross-link content of both the cytosolic and the nuclear protein fractions increased while NB4 cells underwent cellular maturation. Inhibition of cross-linking activity of TG2 by monodansylcadaverin in these cells led to diminished nitroblue tetrazolium (NBT) positivity, production of less superoxide anion, and decreased expression of GP91PHOX, the membrane-associated subunit of NADPH oxidase. Neutrophils isolated from TG2–/– mice showed diminished NBT reduction capacity, reduced superoxide anion formation, and down-regulation of the gp91phox subunit of NADPH oxidase, compared with wild-type cells. It was also observed that TG2–/– mice exhibited increased neutrophil phagocytic activity, but had attenuated neutrophil chemotaxis and impaired neutrophil extravasation with higher neutrophil counts in their circulation during yeast extract–induced peritonitis. These results clearly suggest that TG2 may modulate the expression of genes related to neutrophil functions and is involved in several intracellular and extracellular functions of extravasating neutrophil.
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Affiliation(s)
- Zoltán Balajthy
- Department of Biochemistry and Molecular Biology, University of Debrecen, Medical and Health Science Center, H-4012 Debrecen, Nagyerdei krt. 98, Hungary.
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138
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Bailey CDC, Johnson GVW. The protective effects of cystamine in the R6/2 Huntington's disease mouse involve mechanisms other than the inhibition of tissue transglutaminase. Neurobiol Aging 2006; 27:871-9. [PMID: 15896882 DOI: 10.1016/j.neurobiolaging.2005.04.001] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2005] [Revised: 04/05/2005] [Accepted: 04/13/2005] [Indexed: 10/25/2022]
Abstract
Tissue transglutaminase (tTG) is a multifunctional enzyme that contributes to disease progression in mouse models of Huntington's disease (HD), an inherited neurodegenerative disease that shows an age-related onset. Moreover, administration of the transglutaminase inhibitor cystamine delays the onset of pathology in the R6/2 HD mouse model. However, the contribution of tTG inhibition towards the therapeutic effects of cystamine has not been determined, as this compound likely has multiple mechanisms of action in the R6/2 mouse. In this study, we found that administration of cystamine in drinking water delayed the age of onset for motor dysfunction and extended lifespan to a similar extent in R6/2 mice that had a normal genetic complement of tTG compared with R6/2 mice that did not express tTG. Since the magnitude of cystamine's therapeutic effects was not affected by the genetic deletion of tTG, these results suggest that the mechanism of action for cystamine in this HD mouse model involves targets other than tTG inhibition.
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Affiliation(s)
- Craig D C Bailey
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham, 1720 7th Avenue South, Sparks Center Room 1061, Birmingham, AL 35294-0017, USA
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139
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Mishra S, Murphy LJ. Phosphorylation of transglutaminase 2 by PKA at Ser216 creates 14-3-3 binding sites. Biochem Biophys Res Commun 2006; 347:1166-70. [PMID: 16870138 DOI: 10.1016/j.bbrc.2006.07.041] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2006] [Accepted: 07/11/2006] [Indexed: 01/19/2023]
Abstract
Transglutaminase 2 (TG2) is a multifunctional ubiquitous enzyme which is present in various cellular compartments and is subject to phosphorylation by PKA. To better understand the relevance of PKA induced phosphorylation of TG2, we performed pull-down assays using phosphorylated biotinylated-TG2(209-223) peptides spanning PKA induced phosphorylation sites as a bait. Subsequent analysis of pull-down protein by SDS-PAGE and LC/MS identified 14-3-3epsilon as the binding partner for TG2 which was further confirmed by immunoblotting with 14-3-3 specific antiserum. In contrast, non-phosphorylated and/or phosphorylation site substituted peptides fail to pull-down 14-3-3. Furthermore, we demonstrate that 14-3-3 co-immunoprecipitated with TG2 antiserum after activation of PKA from mouse embryonic fibroblasts (MEF)(TG2+/+) cells but not from MEF(TG2-/-) cells. In summary, we provide convincing evidence that phosphorylation of TG2 by PKA creates binding site(s) for 14-3-3 both in vitro and in vivo.
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Affiliation(s)
- Suresh Mishra
- Department of Physiology and Internal Medicine, University of Manitoba, Winnipeg, Man., Canada R3E 0W3.
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140
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Singer CF, Hudelist G, Walter I, Rueckliniger E, Czerwenka K, Kubista E, Huber AV. Tissue array-based expression of transglutaminase-2 in human breast and ovarian cancer. Clin Exp Metastasis 2006; 23:33-9. [PMID: 16826431 DOI: 10.1007/s10585-006-9015-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2006] [Accepted: 04/20/2006] [Indexed: 10/24/2022]
Abstract
Transglutaminase-2 is involved in the physiological regulation of cell growth, but has also been associated with a number of cancer-associated features such as cell adhesion, metastasis and extracellular matrix modulation. Despite its importance in tumor cell progression and survival, relatively little is known about its expression in human malignancies. We have therefore investigated the transglutaminase-2 expression pattern in breast and ovarian cancer by using tissue arrays which contained 57 invasive breast cancer biopsies and 62 ovarian cancers, and compared it to transglutaminase-2 protein levels in normal human tissues. By using immunohistochemistry, transglutaminase-2 protein was detected in 48 of 57 breast tumors (84%), with epithelial expression in 26 of 41 (63%) ductal invasive carcinomas and in all 6 (100%) lobular invasive carcinomas. Stromal transglutaminase-2 was present in 14 of 41 (34%) ductal subtypes and in 4 of 6 (67%) lobular subtypes, which is in sharp contrast to the infrequent expression in normal breast stroma (P<0.001, Mann-Whitney test) and somewhat also in normal breast epithelium (P = 0.065, Mann-Whitney test). In most other human tissues, transglutaminase-2 protein was less frequent and usually confined to either the epithelium or in adjacent stroma. In ovarian tumors, the protein was detected in 36 of the 62 cases (58%), and seen in all histological subtypes. Taken together, we have demonstrated increased transglutaminase-2 protein expression in both malignant breast epithelium and surrounding stroma, although its selective spatial expression pattern in normal tissues also indicates a physiological role in stromal-epithelial interactions.
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Affiliation(s)
- Christian F Singer
- Division of Special Gynaecology , Vienna Medical University, Vienna, Austria.
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141
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Jogie-Brahim S, Min HK, Oh Y. Potential of proteomics towards the investigation of the IGF-independent actions of IGFBP-3. Expert Rev Proteomics 2006; 2:71-86. [PMID: 15966854 DOI: 10.1586/14789450.2.1.71] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Early investigations into the insulin-like growth factor (IGF)-independent actions of insulin-like growth factor-binding protein (IGFBP)-3 have implicated a large array of signaling proteins with links to cell cycle control and apoptosis. However, the actual mechanism of IGFBP-3 action is still unclear. In an effort to clearly understand the mechanism of IGF-independent IGFBP-3 actions, a proteomic approach to identify the actual proteins involved in interaction with IGFBP-3 from different cell compartments, the phosphorylation status of IGFBP-3 under different physiologic conditions and the proteins upregulated by IGFBP-3 are briefly reviewed. The IGF system is a well-recognized key player in diseases such as cancer, diabetes and malnutrition. It is only after the signaling pathways of the IGF-independent actions of IGFBP-3 are clearly understood that the system can be manipulated to affect these disorders.
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Affiliation(s)
- Sherryline Jogie-Brahim
- Department of Pathology, Virginia Commonwealth University, School of Medicine, MCV Campus, Sanger Hall, Room 5-011, 1101 East Marshall Street, PO Box 980662, Richmond, Virginia 23298-0662, USA.
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142
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Begg GE, Holman SR, Stokes PH, Matthews JM, Graham RM, Iismaa SE. Mutation of a critical arginine in the GTP-binding site of transglutaminase 2 disinhibits intracellular cross-linking activity. J Biol Chem 2006; 281:12603-9. [PMID: 16522628 DOI: 10.1074/jbc.m600146200] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Transglutaminase type 2 (TG2; also known as G(h)) is a multifunctional protein involved in diverse cellular processes. It has two well characterized enzyme activities: receptor-stimulated signaling that requires GTP binding and calcium-activated transamidation or cross-linking that is inhibited by GTP. In addition to the GDP binding residues identified from the human TG2 crystal structure (Liu, S., Cerione, R. A., and Clardy, J. (2002) Proc. Natl. Acad. Sci. U. S. A. 99, 2743-2747), we have previously implicated Ser171 in GTP binding, as binding is lost with glutamate substitution (Iismaa, S. E., Wu, M.-J., Nanda, N., Church, W. B., and Graham, R. M. (2000) J. Biol. Chem. 275, 18259-18265). Here, we have shown that alanine substitution of homologous residues in rat TG2 (Phe174 in the core domain or Arg476, Arg478, or Arg579 in barrel 1) does not affect TG activity but reduces or abolishes GTP binding and GTPgammaS inhibition of TG activity in vitro, indicating that these residues are important in GTP binding. Alanine substitution of Ser171 does not impair GTP binding, indicating this residue does not interact directly with GTP. Arg579 is particularly important for GTP binding, as isothermal titration calorimetry demonstrated a 100-fold reduction in GTP binding affinity by the R579A mutant. Unlike wild-type TG2 or its S171E or F174A mutants, which are sensitive to both trypsin and mu-calpain digestion, R579A is inherently more resistant to mu-calpain, but not trypsin, digestion, indicating reduced accessibility and/or flexibility of this mutant in the region of the calpain cleavage site(s). Basal TG activity of intact R579A stable SH-SY5Y neuroblastoma cell transfectants was slightly increased relative to wild-type transfectants and, in contrast to the TG activity of the latter, was further stimulated by muscarinic receptor-activated calcium mobilization. Thus, loss of GTP binding sensitizes TG2 to intracellular calcium concentrations. These findings are consistent with the notion that intracellularly, under physiological conditions, TG2 is maintained largely as a latent enzyme, its calcium-activated cross-linking activity being suppressed allosterically by guanine nucleotide binding.
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Affiliation(s)
- Gillian E Begg
- Molecular Cardiology Program, Victor Chang Cardiac Research Institute, Darlinghurst, New South Wales 2010, Australia
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143
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Mishra S, Saleh A, Espino PS, Davie JR, Murphy LJ. Phosphorylation of histones by tissue transglutaminase. J Biol Chem 2006; 281:5532-8. [PMID: 16407273 DOI: 10.1074/jbc.m506864200] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Tissue transglutaminase 2 (TG2) has recently been shown to have intrinsic serine/threonine kinase activity. Since histones are known to be cross-linked by TG2, we investigated whether histones are also substrates for TG2 kinase activity. TG2 was able to phosphorylate H1, H2A, H2B, H3, and H4 histones in vitro. Using peptide substrates and phosphospecific antibodies we demonstrated that TG2 phosphorylated Ser(10) in H3 and that this phosphorylation was reduced by acetylation, whereas phosphorylation of Ser(10) by TG2 enhanced acetylation. Furthermore we demonstrated that exogenous TG2 phosphorylated H1 and H3 in nucleosome preparations. We examined the abundance of TG2 in DNA-associated proteins from MCF-7 cells treated with phorbol ester (TPA) and 17beta-estradiol (E2). TG2 abundance was significantly reduced in E2-treated cells and enhanced in TPA-treated cells. In summary we have demonstrated that TG2 is able to phosphorylate purified histone proteins, and H3 and H1 in chromatin preparations, and it is associated with chromatin in breast cancer cells. These studies suggest a novel role for TG2 in the regulation of chromatin structure and function.
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Affiliation(s)
- Suresh Mishra
- Department of Physiology, University of Manitoba, Winnipeg, Manitoba R3E 0W3, Canada
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144
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Mishra S, Murphy LJ. The p53 oncoprotein is a substrate for tissue transglutaminase kinase activity. Biochem Biophys Res Commun 2005; 339:726-30. [PMID: 16313886 DOI: 10.1016/j.bbrc.2005.11.071] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2005] [Accepted: 11/13/2005] [Indexed: 12/18/2022]
Abstract
Increased expression and activity of the ubiquitous enzyme, tissue transglutaminase (TG2), is consistently seen in a variety of models of apoptosis. The p53 oncoprotein is also involved in apoptosis. Here we investigated the interaction of TG2 with p53 and show that the p53 is a substrate for the recently identified serine/threonine kinase activity of TG2. Phosphospecific antibodies indicated that TG2 phosphorylated p53 at Ser(15) and Ser(20), residues that are critically important in the interaction of p53 with Mdm2. The TG2-induced phosphorylation was abrogated by high Ca(2+) concentrations and inhibited by cystamine, a known inhibitor of TG2 cross-linking activity. Furthermore, we demonstrate that TG2-induced phosphorylation of p53 reduces the ability of p53 to interact with Mdm2. Although TG2 cross-linking activity has been clearly implicated in apoptosis, our observations reported here suggest TG2 modification of p53 could be an additional mechanism whereby TG2 could facilitate apoptosis.
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Affiliation(s)
- Suresh Mishra
- Department of Physiology, University of Manitoba, Winnipeg, Canada R3E 0W3
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145
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Gustafsson AC, Kupershmidt I, Edlundh-Rose E, Greco G, Serafino A, Krasnowska EK, Lundeberg T, Bracci-Laudiero L, Romano MC, Parasassi T, Lundeberg J. Global gene expression analysis in time series following N-acetyl L-cysteine induced epithelial differentiation of human normal and cancer cells in vitro. BMC Cancer 2005; 5:75. [PMID: 16001974 PMCID: PMC1182358 DOI: 10.1186/1471-2407-5-75] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2004] [Accepted: 07/07/2005] [Indexed: 01/07/2023] Open
Abstract
Background Cancer prevention trials using different types of antioxidant supplements have been carried out at several occasions and one of the investigated compounds has been the antioxidant N-acetyl-L-cysteine (NAC). Studies at the cellular level have previously demonstrated that a single supplementation of NAC induces a ten-fold more rapid differentiation in normal primary human keratinocytes as well as a reversion of a colon carcinoma cell line from neoplastic proliferation to apical-basolateral differentiation [1]. The investigated cells showed an early change in the organization of the cytoskeleton, several newly established adherens junctions with E-cadherin/β-catenin complexes and increased focal adhesions, all features characterizing the differentiation process. Methods In order to investigate the molecular mechanisms underlying the proliferation arrest and accelerated differentiation induced by NAC treatment of NHEK and Caco-2 cells in vitro, we performed global gene expression analysis of NAC treated cells in a time series (1, 12 and 24 hours post NAC treatment) using the Affymetrix GeneChip™ Human Genome U95Av2 chip, which contains approximately 12,000 previously characterized sequences. The treated samples were compared to the corresponding untreated culture at the same time point. Results Microarray data analysis revealed an increasing number of differentially expressed transcripts over time upon NAC treatment. The early response (1 hour) was transient, while a constitutive trend was commonly found among genes differentially regulated at later time points (12 and 24 hours). Connections to the induction of differentiation and inhibition of growth were identified for a majority of up- and down-regulated genes. All of the observed transcriptional changes, except for seven genes, were unique to either cell line. Only one gene, ID-1, was mutually regulated at 1 hour post treatment and might represent a common mediator of early NAC action. The detection of several genes that previously have been identified as stimulated or repressed during the differentiation of NHEK and Caco-2 provided validation of results. In addition, real-time kinetic PCR analysis of selected genes also verified the differential regulation as identified by the microarray platform. Conclusion NAC induces a limited and transient early response followed by a more consistent and extensively different expression at later time points in both the normal and cancer cell lines investigated. The responses are largely related to inhibition of proliferation and stimulation of differentiation in both cell types but are almost completely lineage specific. ID-1 is indicated as an early mediator of NAC action.
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Affiliation(s)
- Anna C Gustafsson
- Royal Institute of Technology, AlbaNova University Center, Department of Biotechnology, Roslagstullsbacken 21, SE-106 91 Stockholm, Sweden
| | - Ilya Kupershmidt
- Royal Institute of Technology, AlbaNova University Center, Department of Biotechnology, Roslagstullsbacken 21, SE-106 91 Stockholm, Sweden
- Silicon Genetics, 2601 Spring Street, Redwood City, California 94063, USA
| | - Esther Edlundh-Rose
- Royal Institute of Technology, AlbaNova University Center, Department of Biotechnology, Roslagstullsbacken 21, SE-106 91 Stockholm, Sweden
| | - Giulia Greco
- Istituto di Neurobiologia e Medicina Molecolare, CNR, Viale Marx 15-43, 00137 Roma, Italy
| | - Annalucia Serafino
- Istituto di Neurobiologia e Medicina Molecolare, CNR, Viale Marx 15-43, 00137 Roma, Italy
| | - Eva K Krasnowska
- Istituto di Neurobiologia e Medicina Molecolare, CNR, Viale Marx 15-43, 00137 Roma, Italy
| | - Thomas Lundeberg
- Rehabilitation Medicine, Karolinska University Hospital, 117 76 Stockholm, Sweden
| | - Luisa Bracci-Laudiero
- Associazione Italiana Iniziativa Medicina Sociale, Corso Trieste 16, 00185 Roma, Italy
| | - Maria-Concetta Romano
- Associazione Italiana Iniziativa Medicina Sociale, Corso Trieste 16, 00185 Roma, Italy
| | - Tiziana Parasassi
- Istituto di Neurobiologia e Medicina Molecolare, CNR, Viale Marx 15-43, 00137 Roma, Italy
| | - Joakim Lundeberg
- Royal Institute of Technology, AlbaNova University Center, Department of Biotechnology, Roslagstullsbacken 21, SE-106 91 Stockholm, Sweden
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146
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Linge C, Richardson J, Vigor C, Clayton E, Hardas B, Rolfe K. Hypertrophic Scar Cells Fail to Undergo a Form of Apoptosis Specific to Contractile Collagen—The Role of Tissue Transglutaminase. J Invest Dermatol 2005; 125:72-82. [PMID: 15982305 DOI: 10.1111/j.0022-202x.2005.23771.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Failure of apoptosis has been postulated to cause the hypercellularity and thus excess scar-tissue formation of hypertrophic scars (HTS). Here, we have examined the susceptibility of fibroblasts derived from normal or HTS to apoptosis induced during collagen-gel contraction, a wound-healing model. Normal scar (NS) fibroblasts underwent significant apoptosis (>40% total) in contractile collagen, whereas apoptosis was not detected in HTS cells. This inability was specific to apoptosis induced by contractile collagen because apoptosis could be induced using diverse modalities. Since chronic fibrotic tissue is known to be excessively cross-linked, we next examined whether collagen matrix that had been conditioned by HTS fibroblasts became refractory to enzymatic breakdown and indeed, found that it is resistant to breakdown by both collagenase D and matrix metalloproteinase-2. Newly formed extracellular matrix is stabilized by the enzyme, tissue transglutaminase, which we demonstrated to be overexpressed by HTS fibroblasts in vivo and in vitro. Reducing tissue transglutaminase activity in collagen gels containing HTS fibroblasts permitted induction of apoptosis on gel contraction, whereas increasing enzymic activity in NS cell-containing gels completely abrogated collagen-contraction-induced-apoptosis. Together, these observations show that HTS fibroblasts exhibit resistance to a specific form of apoptosis elicited by contraction of collagen gels, and that this phenomenon is dependent on excess activity of cell surface tissue transglutaminase.
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Affiliation(s)
- Claire Linge
- The RAFT Institute of Plastic Surgery, Mount Vernon Hospital, Northwood, Middlesex, UK.
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147
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Fésüs L, Szondy Z. Transglutaminase 2 in the balance of cell death and survival. FEBS Lett 2005; 579:3297-302. [PMID: 15943974 DOI: 10.1016/j.febslet.2005.03.063] [Citation(s) in RCA: 143] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/23/2005] [Indexed: 12/17/2022]
Abstract
Transglutaminase 2 (TG2), a multifunctional enzyme with Ca(2+)-dependent protein crosslinking activity and GTP-dependent G protein functions, is often upregulated in cells undergoing apoptosis. In cultured cells TG2 may exert both pro- and anti-apoptotic effects depending upon the type of cell, the kind of death stimuli, the intracellular localization of the enzyme and the type of its activities switched on. The majority of data support the notion that transamidation by TG2 can both facilitate and inhibit apoptosis, while the GTP-bound form of the enzyme generally protects cells against death. In vivo studies confirm the Janus face of TG2 in the initiation of the apoptotic program. In addition, they reveal a further role: the prevention of inflammation, tissue injury and autoimmunity once the apoptosis has already been initiated. This function of TG2 is partially achieved by being expressed and activated also in macrophages digesting apoptotic cells and mediating a crosstalk between dying and phagocytic cells.
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Affiliation(s)
- László Fésüs
- Department of Biochemistry and Molecular Biology, Faculty of Medicine and Signaling and Apoptosis Research Group of the Hungarian Academy of Sciences, Research Center for Molecular Medicine, University of Debrecen, Debrecen, Hungary.
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148
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Choi K, Siegel M, Piper JL, Yuan L, Cho E, Strnad P, Omary B, Rich KM, Khosla C. Chemistry and Biology of Dihydroisoxazole Derivatives: Selective Inhibitors of Human Transglutaminase 2. ACTA ACUST UNITED AC 2005; 12:469-75. [PMID: 15850984 DOI: 10.1016/j.chembiol.2005.02.007] [Citation(s) in RCA: 128] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2005] [Revised: 02/12/2005] [Accepted: 02/15/2005] [Indexed: 11/16/2022]
Abstract
3-halo-4,5-dihydroisoxazoles are attractive warheads for the selective inhibition of nucleophilic active sites in biological systems. A series of 3-bromo-4,5-dihydroisoxazole compounds were prepared and tested for their ability to irreversibly inhibit human transglutaminase 2 (TG2), an enzyme that plays an important role in the pathogenesis of diverse disorders including Celiac Sprue and certain types of cancers. Several compounds showed high specificity for human TG2 (k(inh)/K(I) > 2000 min(-1)M(-1)) but essentially no reactivity (k < 1 min(-1)M(-1)) toward physiological thiols such as glutathione. The pharmacokinetic and pharmacodynamic properties of a prototype dihydroisoxazole inhibitor, 1b, were evaluated; in mice the compound showed good oral bioavailability, short serum half-life and efficient TG2 inhibition in small intestinal tissue, and low toxicity. It also showed excellent synergism with N,N'-bis(2-chloroethyl)-N-nitrosourea (BCNU, carmustine) against refractory glioblastoma tumors in mice. A fluorescent dihydroisoxazole inhibitor 5 facilitated microscopic visualization of TG2 endocytosis from the extracellular surface of HCT-116 cells. Together, these findings demonstrate the promise of dihydroisoxazole compounds as probes for the biology of TG2 and its role in human disease.
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Affiliation(s)
- Kihang Choi
- Department of Chemistry, Stanford University, Stanford, California 94305, USA
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149
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Gendek EG, Kedziora J, Gendek-Kubiak H. Can tissue transglutaminase be a marker of idiopathic inflammatory myopathies? Immunol Lett 2005; 97:245-9. [PMID: 15752564 DOI: 10.1016/j.imlet.2004.11.017] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2004] [Revised: 10/27/2004] [Accepted: 11/08/2004] [Indexed: 11/18/2022]
Abstract
In the normal striated muscle, tissue transglutaminase (TG2) content is vestigial. However, this protein's presence has been reported to occur in myoblasts and myotubes during the fetal period. Its increased expression has been also found in the muscle tissue in the course of sporadic inclusion body myositis, as well as in polymyositis (PM) and dermatomyositis (DM), which are considered to be diseases of immunological origin. Based on in vitro studies, a substantial TG2 role in the infiltration of some T cell subsets into inflamed tissues has been suggested lately. In this study, the immunohistochemical reactions in the guinea pig experimental myositis specimens and in the ones from PM/DM patients were compared. The guinea pig tissue specimens were taken from muscles affected by experimental myositis induced by intramuscular injections of: 1/sera from 30 neoplasm patients with no metastases; 2/sera from 10 healthy people; 3/sera from 2 DM patients; 4/neuropeptides (SP, NPY or VIP) and from 5/the muscles affected by the reversed passive Arthus reaction (RPAR). The immunostaining for TG2 revealed substantial presence of this protein in single, damaged muscle fibers and a weak reaction in regenerating fibers appearing in PM/DM patients' specimens. From among experimental myositis specimens, a very intensive reaction appeared only in the damaged and regenerating muscle fibers present in the slides from guinea pig muscles injected with DM patients' sera. Such results suggest some presence of a specific factor(s) (the one(s) responsible for TG2 expression in the damaged muscle fibers) in DM patients' sera. The results suggest that transglutaminase can be a marker of inflammatory myopathies. A probable correlation between TG2 expression in muscles and organismal immunological factors, including the complement activation status, requires additional studies.
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Affiliation(s)
- Ewa G Gendek
- Department of Chemistry and Clinical Biochemistry, Medical University of Lodz, Pl. Hallera 1, 90-647 Lodz, Poland.
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150
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Rodolfo C, Mormone E, Matarrese P, Ciccosanti F, Farrace MG, Garofano E, Piredda L, Fimia GM, Malorni W, Piacentini M. Tissue transglutaminase is a multifunctional BH3-only protein. J Biol Chem 2004; 279:54783-92. [PMID: 15485857 DOI: 10.1074/jbc.m410938200] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Tissue transglutaminase (TG2) protein accumulates to high levels in cells during early stages of apoptosis both in vivo and in vitro. The analysis of the TG2 primary sequence showed the presence of an eight amino acid domain, sharing 70% identity with the Bcl-2 family BH3 domain. Cell-permeable peptides, mimicking the domain sequence, were able to induce Bax conformational change and translocation to mitochondria, mitochondrial depolarization, release of cytochrome c, and cell death. Moreover, we found that the TG2-BH3 peptides as well as TG2 itself were able to interact with the pro-apoptotic Bcl-2 family member Bax, but not with anti-apoptotic members Bcl-2 and Bcl-X(L). Mutants in the TG2-BH3 domain failed to sensitize cells toward apoptosis. In TG2-overexpressing cells about half of the protein is localized on the outer mitochondrial membrane where, upon cell death induction, it cross-links many protein substrates including Bax. TG2 is the first member of a new subgroup of multifunctional BH3-only proteins showing a large mass size (80 kDa) and enzymatic activity.
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Affiliation(s)
- Carlo Rodolfo
- Department of Biology, University of Rome Tor Vergata, 00133 Rome, Italy
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