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Role of Transglutaminase 2 in Liver Injury via Cross-linking and Silencing of Transcription Factor Sp1

Published:January 16, 2009DOI:https://doi.org/10.1053/j.gastro.2009.01.007

      Background & Aims

      Despite high morbidity and mortality of alcoholic liver disease worldwide, the molecular mechanisms underlying alcohol-induced liver cell death are not fully understood. Transglutaminase 2 (TG2) is a cross-linking enzyme implicated in apoptosis. TG2 levels and activity are increased in association with various types of liver injury. However, how TG2 induces hepatic apoptosis is not known.

      Methods

      Human hepatic cells or primary hepatocytes from rats or TG2+/+ and TG2−/− mice were treated with ethanol. Mice were administered anti-Fas antibody or alcohol. Liver sections were prepared from patients with alcoholic steatohepatitis. Changes in TG2 levels, Sp1 cross-linking and its activities, expression of hepatocyte growth factor receptor, c-Met, and hepatic apoptosis were measured.

      Results

      Ethanol induced apoptosis in hepatic cells, enhanced activity and nuclear accumulation of TG2 as well as accumulation of cross-linked and inactivated Sp1, and reduced expression of the Sp1-responsive gene, c-Met. These effects were rescued by TG2 knockdown, restoration of functional Sp1, or addition of hepatocyte growth factor, whereas apoptosis was reproduced by Sp1 knockdown or TG2 overexpression. Compared with TG2+/+ mice, TG2−/− mice showed markedly reduced hepatocyte apoptosis and Sp1 cross-linking following ethanol or anti-Fas treatment. Treatment of TG2+/+ mice with the TG2 inhibitors putrescine or cystamine blocked anti-Fas–induced hepatic apoptosis and Sp1 silencing. Moreover, enhanced expression of cross-linked Sp1 and TG2 was evident in hepatocyte nuclei of patients with alcoholic steatohepatitis.

      Conclusions

      TG2 induces hepatocyte apoptosis via Sp1 cross-linking and inactivation, with resultant inhibition of the expression of c-Met required for hepatic cell viability.

      Abbreviations used in this paper:

      5-BAPA (5-(biotinamido)pentylamine), CL-Sp1 (cross-linked Sp1), HGF (hepatocyte growth factor), siRNA (small interfering RNA), TG2 (transglutaminase 2)
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      References

        • Ribeiro P.S.
        • Cortez-Pinto H.
        • Solá S.
        • et al.
        Hepatocyte apoptosis, expression of death receptors, and activation of NF-κB in the liver of nonalcoholic and alcoholic steatohepatitis patients.
        Am J Gastroenterol. 2004; 99: 1708-1717
        • Lorand L.
        • Graham R.M.
        Transglutaminases: cross-linking enzymes with pleiotropic functions.
        Nat Rev Mol Cell Biol. 2003; 4: 140-156
        • Fésüs L.
        • Piacentini M.
        Transglutaminase 2: an enigmatic enzyme with diverse functions.
        Trends Biochem Sci. 2002; 27: 534-539
        • Griffin M.
        • Casadio R.
        • Bergamini C.M.
        Transglutaminases: nature's biological glues.
        Biochem J. 2002; 368: 377-396
        • Mirza A.
        • Liu S.L.
        • Frizell E.
        • et al.
        A role for tissue transglutaminase in hepatic injury and fibrogenesis, and its regulation by NF-kB.
        Am J Physiol. 1997; 272: G281-G288
        • Antonyak M.A.
        • Jansen J.M.
        • Miller A.M.
        • et al.
        Two isoforms of tissue transglutaminase mediate opposing cellular fates.
        Proc Natl Acad Sci U S A. 2006; 103: 18609-18614
        • Monsonegro M.
        • Friedmann I.
        • Shani Y.
        • et al.
        GTP-dependent conformational changes associated with the functional switch between Gα and cross-linking activities in brain-derived tissue transglutaminase.
        J Mol Biol. 1998; 282: 713-720
        • Citron B.A.
        • SantaCruz K.S.
        • Davies P.J.
        • et al.
        Intron-exon swapping of transglutaminase mRNA and neuronal Tau aggregation in Alzheimer's disease.
        J Biol Chem. 2001; 276: 3295-3301
        • Wu J.
        • Liu S.L.
        • Zhu J.L.
        • et al.
        Roles of tissue transglutaminase in ethanol-induced inhibition of hepatocyte proliferation and a1-adrenergic signal transduction.
        J Biol Chem. 2000; 275: 22213-22219
        • Nanda N.
        • Iismaa S.E.
        • Owens W.A.
        • et al.
        Targeted inactivation of Gh/tissue transglutaminase II.
        J Biol Chem. 2001; 276: 20673-20678
        • De Laurenzi V.
        • Melino G.
        Gene disruption of tissue transglutaminase.
        Mol Cell Biol. 2001; 21: 148-155
        • Strnad P.
        • Harada M.
        • Siegel M.
        • et al.
        Transglutaminase 2 regulates mallory body inclusion formation and injury-associated liver enlargement.
        Gastroenterology. 2007; 132: 1515-1526
        • Nardacci R.
        • Lo lacono O.
        • Ciccosanti F.
        • et al.
        Transglutaminase type II plays a protective role in hepatic injury.
        Am J Pathol. 2003; 162: 1293-1303
        • Antonyak M.A.
        • Miller A.M.
        • Jansen J.M.
        • et al.
        Augmentation of tissue transglutaminase expression and activation by epidermal growth factor inhibit doxorubicin-induced apoptosis in human breast cancer cells.
        J Biol Chem. 2004; 279: 41461-41467
        • Sarang Z.
        • Molnar P.
        • Nemeth T.
        • et al.
        Tissue transglutaminase (TG2) acting as G protein protects hepatocytes against Fas-mediated cell death in mice.
        Hepatology. 2005; 42: 578-587
        • Fésüs L.
        • Szondy Z.
        Transglutaminase 2 in the balance of cell death and survival.
        FEBS Lett. 2005; 579: 3297-3302
        • Botella L.M.
        • Sanchez-Elsner T.
        • Sanz-Rodriguez F.
        • et al.
        Transcriptional activation of endoglin and transforming growth factor-beta signaling components by cooperative interaction between Sp1 and KLF6: their potential role in the response to vascular injury.
        Blood. 2002; 100: 4001-4010
        • Liu Y.
        The human hepatocyte growth factor receptor gene: complete structural organization and promoter characterization.
        Gene. 1998; 215: 159-169
        • Shimada J.
        • Suzuki Y.
        • Kim S.J.
        • et al.
        Transactivation via RAR/RXR-Sp1 interaction: characterization of binding between Sp1 and GC box motif.
        Mol Endocrinol. 2001; 15: 1677-1692
        • Peng X.
        • Zhang Y.
        • Zhang H.
        • et al.
        Interaction of tissue transglutaminase with nuclear transport protein importin-α3.
        FEBS Lett. 1999; 446: 35-39
        • Minagawa M.
        • Deng Q.
        • Liu Z.X.
        Activated natural killer T cells induce liver injury by Fas and tumor necrosis factor-alpha during alcohol consumption.
        Gastroenterology. 2004; 126: 1387-1399
        • Han J.A.
        • Park S.C.
        Transglutaminase-dependent modulation of transcription factor Sp1 activity.
        Mol Cells. 2000; 10: 612-618
        • Dunah A.W.
        • Jeong H.
        • Griffin A.
        • et al.
        Sp1 and TAFII130 transcriptional activity disrupted in early Huntington's disease.
        Science. 2002; 296: 2238-2243
        • Li S.H.
        • Cheng A.L.
        • Zhou H.
        • et al.
        Interaction of Huntington disease protein with transcriptional activator Sp1.
        Mol Cell Biol. 2002; 22: 1277-1287
        • Zhai W.
        • Jeong H.
        • Cui L.
        • et al.
        In vitro analysis of Huntington-mediated transcriptional repression reveals multiple transcription factor targets.
        Cell. 2005; 123: 1241-1253
        • Stabile L.P.
        • Lyker J.S.
        • Huang L.
        • et al.
        Inhibition of human non-small cell lung tumors by a c-Met antisense/U6 expression plasmid strategy.
        Gene Ther. 2004; 11: 325-335

      References

        • Wu J.
        • Liu S.L.
        • Zhu J.L.
        • et al.
        Roles of tissue transglutaminase in ethanol-induced inhibition of hepatocyte proliferation and alpha 1-adrenergic signal transduction.
        J Biol Chem. 2000; 275: 22213-22219
        • Shimada J.
        • Suzuki Y.
        • Kim S.J.
        • et al.
        Transactivation via RAR/RXR-Sp1 interaction: characterization of binding between Sp1 and GC box motif.
        Mol Endocrinol. 2001; 15: 1677-1692
        • Kojima S.
        • Inui T.
        • Muramatsu H.
        • et al.
        Dimerization of midkine by tissue transglutaminase and its functional implication.
        J Biol Chem. 1997; 272: 9410-9416
        • Mignon A.
        • Guidotti J.E.
        • Mitchell C.
        • et al.
        Selective repopulation of normal mouse liver by Fas/CD95-resistant hepatocytes.
        Nat Med. 1998; 4: 1185-1188
        • Tsukamoto H.
        • Gaal K.
        • French S.W.
        Insights into the pathogenesis of alcoholic liver necrosis and fibrosis: status report.
        Hepatology. 1990; 12: 599-608
        • Botella L.M.
        • Sanchez-Elsner T.
        • Sanz-Rodriguez F.
        • et al.
        Transcriptional activation of endoglin and transforming growth factor-beta signaling components by cooperative interaction between Sp1 and KLF6: their potential role in the response to vascular injury.
        Blood. 2002; 100: 4001-4010
        • Narla G.
        • Heath K.E.
        • Reeves H.L.
        • et al.
        KLF6, a candidate tumor suppressor gene mutated in prostate cancer.
        Science. 2001; 294: 2563-2566

      Linked Article

      • Transglutaminase Cross-Links Sp1-Mediated Transcription to Ethanol-Induced Liver Injury
        GastroenterologyVol. 136Issue 5
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          Ethanol consumption represents a major global health burden, accounting for almost 2 million deaths annually.1 Excessive alcohol intake may cause alcoholic hepatitis or, potentially, liver cancer given that alcohol-related liver disease (ALD) is the leading cause of cirrhosis in countries with established economies.1 The effect of ethanol on the liver is rather complex, even though ethanol constitutes a chemically simple molecule, CH3CH2OH. These effects include the production of reactive oxygen species, compromised mitochondrial function, and alteration of multiple signaling pathways.
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