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Vunnam N, Szymonski S, Hirsova P, Gores GJ, Sachs JN, Hackel BJ. Noncompetitive Allosteric Antagonism of Death Receptor 5 by a Synthetic Affibody Ligand. Biochemistry 2020; 59:3856-3868. [PMID: 32941010 PMCID: PMC7658720 DOI: 10.1021/acs.biochem.0c00529] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Fatty acid-induced upregulation of death receptor 5 (DR5) and its cognate ligand, tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), promotes hepatocyte lipoapoptosis, which is a key mechanism in the progression of fatty liver disease. Accordingly, inhibition of DR5 signaling represents an attractive strategy for treating fatty liver disease. Ligand competition strategies are prevalent in tumor necrosis factor receptor antagonism, but recent studies have suggested that noncompetitive inhibition through perturbation of the receptor conformation may be a compelling alternative. To this end, we used yeast display and a designed combinatorial library to identify a synthetic 58-amino acid affibody ligand that specifically binds DR5. Biophysical and biochemical studies show that the affibody neither blocks TRAIL binding nor prevents the receptor-receptor interaction. Live-cell fluorescence lifetime measurements indicate that the affibody induces a conformational change in transmembrane dimers of DR5 and favors an inactive state of the receptor. The affibody inhibits apoptosis in TRAIL-treated Huh-7 cells, an in vitro model of fatty liver disease. Thus, this lead affibody serves as a potential drug candidate, with a unique mechanism of action, for fatty liver disease.
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Kaplan A, Rosenblatt R, Buckholz A, Kumar S, Parthasarathy G, Schwartz RE, Hirsova P, Schwartz RE, Pisa JF, Brown RS, Jalan-Sakrikar N, Schwartz RE, Jesudian AB, Russo NW, Allamneni C, Vora RS, Kostallari E, Schwartz RE. Hepatology Highlights. Hepatology 2020; 72:791-793. [PMID: 33464576 DOI: 10.1002/hep.31544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/07/2022]
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Pisa JF, Brown RS, Hirsova P, Schwartz RE, Sehrawat TS, Russo NW, Kostallari E, Tafesh ZH, Fortune B, Trivedi HD, Lau DTY, Morales-Santiago A, Wedd J, Buchl SC, Maiers JL. Hepatology Highlights. Hepatology 2020; 71:1527-1529. [PMID: 32347990 DOI: 10.1002/hep.31275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/07/2022]
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Lapumnuaypol K, Danford CJ, Lau DTY, Pisa JF, Brown RS, Morales Santiago A, Roccaro G, Navarro-Corcuera A, Schwartz RE, Kostallari E, Russo NW, Hirsova P, Maiers JL, Jalan-Sakrikar N. Hepatology Highlights. Hepatology 2020; 71:1143-1145. [PMID: 32276302 DOI: 10.1002/hep.31243] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/07/2022]
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Jalan-Sakrikar N, Schwartz RE, Amir M, Wedd J, Pisa JF, Brown RS, Russo NW, Vora RS, Kaplan A, Rosenblatt R, Navarro-Corcuera A, Kostallari E, Hirsova P. Hepatology Highlights. Hepatology 2020; 71:771-773. [PMID: 32200569 DOI: 10.1002/hep.31203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/07/2022]
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Hirsova P, Bohm F, Dohnalkova E, Nozickova B, Heikenwalder M, Gores GJ, Weber A. Hepatocyte apoptosis is tumor promoting in murine nonalcoholic steatohepatitis. Cell Death Dis 2020; 11:80. [PMID: 32015322 PMCID: PMC6997423 DOI: 10.1038/s41419-020-2283-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Revised: 01/14/2020] [Accepted: 01/17/2020] [Indexed: 02/07/2023]
Abstract
Nonalcoholic fatty liver disease is the most common chronic liver disease and may progress to nonalcoholic steatohepatitis (NASH) and hepatocellular carcinoma (HCC). The molecular determinants of this pathogenic progression, however, remain largely undefined. Since liver tumorigenesis is driven by apoptosis, we examined the effect of overt hepatocyte apoptosis in a mouse model of NASH using mice lacking myeloid cell leukemia 1 (Mcl1), a pro-survival member of the BCL-2 protein family. Hepatocyte-specific Mcl1 knockout (Mcl1∆hep) mice and control littermates were fed chow or FFC (high saturated fat, fructose, and cholesterol) diet, which induces NASH, for 4 and 10 months. Thereafter, liver injury, inflammation, fibrosis, and tumor development were evaluated biochemically and histologically. Mcl1∆hep mice fed with the FFC diet for 4 months displayed a marked increase in liver injury, hepatocyte apoptosis, hepatocyte proliferation, macrophage-associated liver inflammation, and pericellular fibrosis in contrast to chow-fed Mcl1∆hep and FFC diet-fed Mcl1-expressing littermates. After 10 months of feeding, 78% of FFC diet-fed Mcl1∆hep mice developed liver tumors compared to 38% of chow-fed mice of the same genotype. Tumors in FFC diet-fed Mcl1∆hep mice were characterized by cytologic atypia, altered liver architecture, immunopositivity for glutamine synthetase, and histologically qualified as HCC. In conclusion, this study provides evidence that excessive hepatocyte apoptosis exacerbates the NASH phenotype with enhancement of tumorigenesis in mice.
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Kaplan A, Rosenblatt R, Russo NW, Brown RS, Pisa JF, Hirsova P, Schwartz RE, Kostallari E, Jalan-Sakrikar N, Idriss R, Trivedi H, Lau DTY, Navarro-Corcuera A. Hepatology Highlights. Hepatology 2020; 71:405-407. [PMID: 32037633 DOI: 10.1002/hep.31119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/07/2022]
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Dusek J, Skoda J, Holas O, Horvatova A, Smutny T, Linhartova L, Hirsova P, Kucera O, Micuda S, Braeuning A, Pavek P. Stilbene compound trans-3,4,5,4´-tetramethoxystilbene, a potential anticancer drug, regulates constitutive androstane receptor (Car) target genes, but does not possess proliferative activity in mouse liver. Toxicol Lett 2019; 313:1-10. [PMID: 31170421 DOI: 10.1016/j.toxlet.2019.05.024] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Revised: 05/21/2019] [Accepted: 05/29/2019] [Indexed: 01/06/2023]
Abstract
The constitutive androstane receptor(CAR) activation is connected with mitogenic effects leading to liver hyperplasia and tumorigenesis in rodents. CAR activators, including phenobarbital, are considered rodent non-genotoxic carcinogens. Recently, trans-3,4,5,4´-tetramethoxystilbene(TMS), a potential anticancer drug (DMU-212), have been shown to alleviate N-nitrosodiethylamine/phenobarbital-induced liver carcinogenesis. We studied whether TMS inhibits mouse Car to protect from the PB-induced tumorigenesis. Unexpectedly, we identified TMS as a murine CAR agonist in reporter gene experiments, in mouse hepatocytes, and in C57BL/6 mice in vivo. TMS up-regulated Car target genes Cyp2b10, Cyp2c29 and Cyp2c55 mRNAs, but down-regulated expression of genes involved in gluconeogenesis and lipogenesis. TMS did not change or down-regulate genes involved in liver proliferation or apoptosis such as Mki67, Foxm1, Myc, Mcl1, Pcna, Bcl2, or Mdm2, which were up-regulated by another Car ligand TCPOBOP. TMS did not increase liver weight and had no significant effect on Ki67 and Pcna labeling indices in mouse liver in vivo. In murine hepatic AML12 cells, we confirmed a Car-independent proapoptotic effect of TMS. We conclude that TMS is a Car ligand with limited effects on hepatocyte proliferation, likely due to promoting apoptosis in mouse hepatic cells, while controlling Car target genes involved in xenobiotic and endobiotic metabolism.
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Hirsova P, Malhi H, Russo N, Shah PA, Trivedi H, Lau DTY, Pisa JF, Wu A, Shen N, Jesudian A, Tafesh ZH, Fortune BE, Hilscher M, Jalan-Sakrikar N, Mousa O. Hepatology Highlights. Hepatology 2019; 70:455-458. [PMID: 31376309 DOI: 10.1002/hep.30868] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/07/2022]
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Suri JS, Ezaz G, Lau DTY, Kulai TB, Malhi H, Tafesh ZH, Fortune B, Rosenblatt R, Brown RS, Pisa JF, Russo N, Hirsova P, Schwartz RE, Obaidullah Aseem S, Jalan-Sakrikar N, Gupta V. Hepatology Highlights. Hepatology 2019; 69:2311-2314. [PMID: 31141204 DOI: 10.1002/hep.30775] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/07/2022]
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Trivedi HD, Lau DTY, Kulai TB, Malhi H, Schwartz RE, Pisa JF, Brown RS, Russo N, Nair KM, Roccaro G, Hirsova P, Gupta V, Xu X, Krisko T, Kostallari E. Hepatology Highlights. Hepatology 2019; 69:1849-1851. [PMID: 30977535 DOI: 10.1002/hep.30634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/07/2022]
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Nair KM, Vora RS, Mousa OY, Malhi H, Schwartz RE, Pisa JF, Brown RS, Trivedi HD, Lau DTY, Shen N, Shenoy A, Maiers JL, Kostallari E, Hirsova P, Russo N, Kulai TB. Hepatology Highlights. Hepatology 2019; 69:1365-1368. [PMID: 30920689 DOI: 10.1002/hep.30618] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/07/2022]
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Mousa O, Malhi H, Schwartz RE, Kulai TB, Trivedi HD, Lau DTY, Shen NT, Brown RS, Hirsova P, Xu X, Nicholls HT, Pisa JF, Tafesh ZH, Fortune BE, Gupta V, Kostallari E, Russo N, Jesudian AB. Hepatology Highlights. Hepatology 2019; 69:927-930. [PMID: 30811657 DOI: 10.1002/hep.30569] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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Gutierrez Sanchez LH, Tomita K, Guo Q, Furuta K, Alhuwaish H, Hirsova P, Baheti S, Alver B, Hlady R, Robertson KD, Ibrahim SH. Perinatal Nutritional Reprogramming of the Epigenome Promotes Subsequent Development of Nonalcoholic Steatohepatitis. Hepatol Commun 2018; 2:1493-1512. [PMID: 30556038 PMCID: PMC6287484 DOI: 10.1002/hep4.1265] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Accepted: 09/07/2018] [Indexed: 12/28/2022] Open
Abstract
With the epidemic of obesity, nonalcoholic fatty liver disease (NAFLD) has become the most common pediatric liver disease. The influence of a perinatal obesity‐inducing diet (OID) on the development and progression of NAFLD in offspring is important but incompletely studied. Hence, we fed breeding pairs of C57BL/6J mice during gestation and lactation (perinatally) either chow or an OID rich in fat, fructose, and cholesterol (FFC). The offspring were weaned to either chow or an FFC diet, generating four groups: perinatal (p)Chow‐Chow, pChow‐FFC, pFFC‐Chow, and pFFC‐FFC. Mice were sacrificed at 10 weeks of age. We examined the whole‐liver transcriptome by RNA sequencing (RNA‐seq) and whole‐liver genome methylation by reduced representation bisulfite sequencing (RRBS). Our results indicated that the pFFC‐FFC mice had a significant increase in hepatic steatosis, injury, inflammation, and fibrosis, as assessed histologically and biochemically. We identified 189 genes that were differentially expressed and methylated in the pFFC‐FFC mice versus the pChow‐FFC mice. Gene set enrichment analysis identified hepatic fibrosis/hepatic stellate cell activation as the top canonical pathway, suggesting that the differential DNA methylation events in the mice exposed to the FFC diet perinatally were associated with a profibrogenic transcriptome. To verify that this finding was consistent with perinatal nutritional reprogramming of the methylome, we exposed pFFC‐Chow mice to an FFC diet in adulthood. These mice developed significant hepatic steatosis, injury, inflammation, and more importantly fibrosis when compared to the appropriate controls. Conclusion: Perinatal exposure to an OID primes the immature liver for an accentuated fibrosing nonalcoholic steatohepatitis (NASH) phenotype, likely through nutritional reprogramming of the offspring methylome. These data have potential clinical implications for monitoring children of obese mothers and risk stratification of children with NAFLD.
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Kostallari E, Hirsova P, Prasnicka A, Verma VK, Yaqoob U, Wongjarupong N, Roberts LR, Shah VH. Hepatic stellate cell-derived platelet-derived growth factor receptor-alpha-enriched extracellular vesicles promote liver fibrosis in mice through SHP2. Hepatology 2018; 68:333-348. [PMID: 29360139 PMCID: PMC6033667 DOI: 10.1002/hep.29803] [Citation(s) in RCA: 67] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Revised: 01/17/2018] [Accepted: 01/18/2018] [Indexed: 12/11/2022]
Abstract
UNLABELLED Liver fibrosis is characterized by the activation and migration of hepatic stellate cells (HSCs), followed by matrix deposition. Recently, several studies have shown the importance of extracellular vesicles (EVs) derived from liver cells, such as hepatocytes and endothelial cells, in liver pathobiology. While most of the studies describe how liver cells modulate HSC behavior, an important gap exists in the understanding of HSC-derived signals and more specifically HSC-derived EVs in liver fibrosis. Here, we investigated the molecules released through HSC-derived EVs, the mechanism of their release, and the role of these EVs in fibrosis. Mass spectrometric analysis showed that platelet-derived growth factor (PDGF) receptor-alpha (PDGFRα) was enriched in EVs derived from PDGF-BB-treated HSCs. Moreover, patients with liver fibrosis had increased PDGFRα levels in serum EVs compared to healthy individuals. Mechanistically, in vitro tyrosine720-to-phenylalanine mutation on the PDGFRα sequence abolished enrichment of PDGFRα in EVs and redirected the receptor toward degradation. Congruently, the inhibition of Src homology 2 domain tyrosine phosphatase 2, the regulatory binding partner of phosphorylated tyrosine720, also inhibited PDGFRα enrichment in EVs. EVs derived from PDGFRα-overexpressing cells promoted in vitro HSC migration and in vivo liver fibrosis. Finally, administration of Src homology 2 domain tyrosine phosphatase 2inhibitor, SHP099, to carbon tetrachloride-administered mice inhibited PDGFRα enrichment in serum EVs and reduced liver fibrosis. CONCLUSION PDGFRα is enriched in EVs derived from PDGF-BB-treated HSCs in an Src homology 2 domain tyrosine phosphatase 2-dependent manner and these PDGFRα-enriched EVs participate in development of liver fibrosis. (Hepatology 2018;68:333-348).
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Sugihara T, Werneburg NW, Hernandez MC, Yang L, Kabashima A, Hirsova P, Yohanathan L, Sosa C, Truty MJ, Vasmatzis G, Gores GJ, Smoot RL. YAP Tyrosine Phosphorylation and Nuclear Localization in Cholangiocarcinoma Cells Are Regulated by LCK and Independent of LATS Activity. Mol Cancer Res 2018; 16:1556-1567. [PMID: 29903769 DOI: 10.1158/1541-7786.mcr-18-0158] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Revised: 04/18/2018] [Accepted: 05/30/2018] [Indexed: 12/28/2022]
Abstract
The Hippo pathway effector, Yes-associated protein (YAP), is a transcriptional coactivator implicated in cholangiocarcinoma (CCA) pathogenesis. YAP is known to be regulated by a serine/threonine kinase relay module (MST1/2-LATS1/2) culminating in phosphorylation of YAP at Serine 127 and cytoplasmic sequestration. However, YAP also undergoes tyrosine phosphorylation, and the role of tyrosine phosphorylation in YAP regulation remains unclear. Herein, YAP regulation by tyrosine phosphorylation was examined in human and mouse CCA cells, as well as patient-derived xenograft (PDX) models. YAP was phosphorylated on tyrosine 357 (Y357) in CCA cell lines and PDX models. SRC family kinase (SFK) inhibition with dasatinib resulted in loss of YAPY357 phosphorylation, promoted its translocation from the nucleus to the cytoplasm, and reduced YAP target gene expression, including cell lines expressing a LATS1/2-resistant YAP mutant in which all serine residues were mutated to alanine. Consistent with these observations, precluding YAPY357 phosphorylation by site-directed mutagenesis (YAPY357F) excluded YAP from the nucleus. Targeted siRNA experiments identified LCK as the SFK that most potently mediated YAPY357 phosphorylation. Likewise, inducible CRISPR/Cas9-targeted LCK deletion decreased YAPY357 phosphorylation and its nuclear localization. The importance of LCK in CCA biology was demonstrated by clinical observations suggesting LCK expression levels were associated with early tumor recurrence following resection of CCA. Finally, dasatinib displayed therapeutic efficacy in PDX models. Mol Cancer Res; 16(10); 1556-67. ©2018 AACR.
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Kabashima A, Hirsova P, Bronk SF, Hernandez MC, Truty MJ, Ilyas SI, Kaufmann SH, Gores GJ. Fibroblast growth factor receptor inhibition induces loss of matrix MCL1 and necrosis in cholangiocarcinoma. J Hepatol 2018; 68:1228-1238. [PMID: 29408314 PMCID: PMC5960421 DOI: 10.1016/j.jhep.2018.01.026] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Revised: 01/18/2018] [Accepted: 01/20/2018] [Indexed: 12/15/2022]
Abstract
BACKGROUND & AIMS Myeloid cell leukemia 1 (MCL1), a prosurvival member of the BCL2 protein family, has a pivotal role in human cholangiocarcinoma (CCA) cell survival. We previously reported that fibroblast growth factor receptor (FGFR) signalling mediates MCL1-dependent survival of CCA cells in vitro and in vivo. However, the mode and mechanisms of cell death in this model were not delineated. METHODS Human CCA cell lines were treated with the pan-FGFR inhibitor LY2874455 and the mode of cell death examined by several complementary assays. Mitochondrial oxidative metabolism was examined using a XF24 extracellular flux analyser. The efficiency of FGFR inhibition in patient-derived xenografts (PDX) was also assessed. RESULTS CCA cells expressed two species of MCL1, a full-length form localised to the outer mitochondrial membrane, and an N terminus-truncated species compartmentalised within the mitochondrial matrix. The pan-FGFR inhibitor LY2874455 induced non-apoptotic cell death in the CCA cell lines associated with cellular depletion of both MCL1 species. The cell death was accompanied by failure of mitochondrial oxidative metabolism and was most consistent with necrosis. Enforced expression of N terminus-truncated MCL1 targeted to the mitochondrial matrix, but not full-length MCL1 targeted to the outer mitochondrial membrane, rescued cell death and mitochondrial function. LY2874455 treatment of PDX-bearing mice was associated with tumour cell loss of MCL1 and cell necrosis. CONCLUSIONS FGFR inhibition induces loss of matrix MCL1, resulting in cell necrosis. These observations support a heretofore unidentified, alternative MCL1 survival function, namely prevention of cell necrosis, and have implications for treatment of human CCA. LAY SUMMARY Herein, we report that therapeutic inhibition of a cell receptor expressed by bile duct cancer cells resulted in the loss of a critical survival protein termed MCL1. Cellular depletion of MCL1 resulted in the death of the cancer cells by a process characterised by cell rupture. Cell death by this process can stimulate the immune system and has implications for combination therapy using receptor inhibition with immunotherapy.
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Ibrahim SH, Hirsova P, Gores GJ. Non-alcoholic steatohepatitis pathogenesis: sublethal hepatocyte injury as a driver of liver inflammation. Gut 2018; 67:963-972. [PMID: 29367207 PMCID: PMC5889737 DOI: 10.1136/gutjnl-2017-315691] [Citation(s) in RCA: 177] [Impact Index Per Article: 29.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Revised: 12/20/2017] [Accepted: 01/04/2018] [Indexed: 02/06/2023]
Abstract
A subset of patients with non-alcoholic fatty liver disease develop an inflammatory condition, termed non-alcoholic steatohepatitis (NASH). NASH is characterised by hepatocellular injury, innate immune cell-mediated inflammation and progressive liver fibrosis. The mechanisms whereby hepatic inflammation occurs in NASH remain incompletely understood, but appear to be linked to the proinflammatory microenvironment created by toxic lipid-induced hepatocyte injury, termed lipotoxicity. In this review, we discuss the signalling pathways induced by sublethal hepatocyte lipid overload that contribute to the pathogenesis of NASH. Furthermore, we will review the role of proinflammatory, proangiogenic and profibrotic hepatocyte-derived extracellular vesicles as disease biomarkers and pathogenic mediators during lipotoxicity. We also review the potential therapeutic strategies to block the feed-forward loop between sublethal hepatocyte injury and liver inflammation.
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Bandla H, Dasgupta D, Mauer AS, Nozickova B, Kumar S, Hirsova P, Graham RP, Malhi H. Deletion of endoplasmic reticulum stress-responsive co-chaperone p58 IPK protects mice from diet-induced steatohepatitis. Hepatol Res 2018; 48:479-494. [PMID: 29316085 PMCID: PMC5932231 DOI: 10.1111/hepr.13052] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Revised: 11/30/2017] [Accepted: 12/29/2017] [Indexed: 01/15/2023]
Abstract
AIM Activation of PKR-like endoplasmic reticulum kinase (PERK), an endoplasmic reticulum stress sensor, is a feature of non-alcoholic steatohepatitis (NASH), yet regulators of PERK signaling remain undefined in this context. The protein p58IPK regulates PERK; however, its role in NASH has not been examined. The aim of this study was to assess the in vivo role of p58IPK in the pathogenesis of dietary NASH. METHODS Parameters of hepatocyte cell death, liver injury, inflammation, fibrosis, indirect calorimetry and PERK activation were assessed in p58IPK knockout (p58ipk-/- ) mice and their wild-type littermate controls. All animals were fed a diet enriched in fat, fructose, and cholesterol (FFC) for 20 weeks. RESULTS Activation of PERK was attenuated in FFC-fed p58ipk-/- mice. Accordingly, FFC-fed p58ipk-/- mice showed a reduction in hepatocyte apoptosis and death receptor expression, with a significant reduction in serum alanine transaminase values. Correspondingly, macrophage accumulation and fibrosis were significantly lower in FFC-fed p58ipk-/- mice. CONCLUSION We have shown that, in an in vivo dietary NASH model, p58IPK mediates hepatocyte apoptosis and liver injury, likely through PERK phosphorylation. In the absence of p58IPK , PERK phosphorylation and NASH are attenuated. Inhibition of hepatic p58IPK could be a future target for NASH therapy.
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Rizvi S, Fischbach SR, Bronk SF, Hirsova P, Krishnan A, Dhanasekaran R, Smadbeck JB, Smoot RL, Vasmatzis G, Gores GJ. YAP-associated chromosomal instability and cholangiocarcinoma in mice. Oncotarget 2017; 9:5892-5905. [PMID: 29464042 PMCID: PMC5814182 DOI: 10.18632/oncotarget.23638] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2017] [Accepted: 12/08/2017] [Indexed: 12/15/2022] Open
Abstract
Deregulated Hippo pathway signaling is associated with aberrant activation of the downstream effector yes-associated protein (YAP), an emerging key oncogenic mediator in cholangiocarcinoma (CCA). In our prior work, we have demonstrated that biliary transduction of YAP along with Akt as a permissive factor induces CCA in mice. To further delineate the mechanisms associated with YAP-associated biliary oncogenesis, we have established seven malignant murine cell lines from our YAP-driven murine CCA model. These cells express the CCA markers SRY (Sex Determining Region Y)-Box 9 (SOX9), cytokeratin (CK)-7 and 19 but lack hepatocyte nuclear factor 4 alpha and alpha-smooth muscle actin, markers of hepatocellular carcinoma and cancer-associated fibroblasts, respectively. Notably, the murine CCA cells can be readily implanted into mouse livers with resultant orthotopic tumor formation. In this unique syngeneic orthotopic murine model, tumors exhibit histopathologic features resembling human CCA. We analyzed transcriptome data from YAP-associated parent CCA tumor nodules and identified a gene expression pattern associated with chromosomal instability, known as CIN25. Similarly, mate-pair sequencing of the murine CCA cells revealed chromosomal missegregation with gains and losses of several whole chromosomes demonstrating aneuploidy. Of the CIN25 genes, forkhead box M1 (Foxm1), a key cell cycle regulator, was the most significantly upregulated CIN25 gene product. Accordingly, small interfering RNA (siRNA)-mediated silencing of YAP as well as FOXM1 inhibition with thiostrepton induced CCA cell death. These preclinical data imply a role for YAP-mediated chromosomal instability in cholangiocarcinoma, and suggest FOXM1 inhibition as a therapeutic target for CCA.
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Tomita K, Kabashima A, Freeman BL, Bronk SF, Hirsova P, Ibrahim SH. Mixed Lineage Kinase 3 Mediates the Induction of CXCL10 by a STAT1-Dependent Mechanism During Hepatocyte Lipotoxicity. J Cell Biochem 2017; 118:3249-3259. [PMID: 28262979 PMCID: PMC5550329 DOI: 10.1002/jcb.25973] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Accepted: 03/02/2017] [Indexed: 01/10/2023]
Abstract
Saturated fatty acids (SFA) and their toxic metabolites contribute to hepatocyte lipotoxicity in nonalcoholic steatohepatitis (NASH). We previously reported that hepatocytes, under lipotoxic stress, express the potent macrophage chemotactic ligand C-X-C motif chemokine 10 (CXCL10), and release CXCL10-enriched extracellular vesicles (EV) by a mixed lineage kinase (MLK) 3-dependent mechanism. In the current study, we sought to examine the signaling pathway responsible for CXCL10 induction during hepatocyte lipotoxicity. Here, we demonstrate a role for signal transducer and activator of transcription (STAT) 1 in regulating CXCL10 expression. Huh7 and HepG2 cells were treated with lysophosphatidylcholine (LPC), the toxic metabolite of the SFA palmitate. In LPC-treated hepatocytes, CXCL10 induction is mediated by a mitogen activated protein kinase (MAPK) signaling cascade consisting of a relay kinase module of MLK3, MKK3/6, and p38. P38 in turn induces STAT1 Ser727 phosphorylation and CXCL10 upregulation in hepatocytes, which is reduced by genetic or pharmacological inhibition of this MAPK signaling cascade. The binding and activity of STAT1 at the CXCL10 gene promoter were identified by chromatin immunoprecipitation and luciferase gene expression assays. Promoter activation was attenuated by MLK3/STAT1 inhibition or by deletion of the consensus STAT1 binding sites within the CXCL10 promoter. In lipotoxic hepatocytes, MLK3 activates a MAPK signaling cascade, resulting in the activating phosphorylation of STAT1, and CXCL10 transcriptional upregulation. Hence, this kinase relay module and/or STAT1 inhibition may serve as a therapeutic target to reduce CXCL10 release, thereby attenuating NASH pathogenesis. J. Cell. Biochem. 118: 3249-3259, 2017. © 2017 Wiley Periodicals, Inc.
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Hirsova P, Guicciardi ME, Gores GJ. Proapoptotic signaling induced by deletion of receptor-interacting kinase 1 and TNF receptor-associated factor 2 results in liver carcinogenesis. Hepatology 2017; 66:983-985. [PMID: 28520112 PMCID: PMC5570646 DOI: 10.1002/hep.29272] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Revised: 05/02/2017] [Accepted: 05/11/2017] [Indexed: 12/27/2022]
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Tomita K, Kohli R, MacLaurin BL, Hirsova P, Guo Q, Sanchez LHG, Gelbard HA, Blaxall BC, Ibrahim SH. Mixed-lineage kinase 3 pharmacological inhibition attenuates murine nonalcoholic steatohepatitis. JCI Insight 2017; 2:94488. [PMID: 28768902 DOI: 10.1172/jci.insight.94488] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Accepted: 06/29/2017] [Indexed: 12/22/2022] Open
Abstract
With the increase in obesity worldwide, its associated comorbidities, including nonalcoholic steatohepatitis (NASH), have become a public health problem that still lacks effective therapy. We have previously reported that mixed-lineage kinase 3-deficient (MLK3-deficient) mice are protected against diet-induced NASH. Given the critical need to identify new therapeutic agents, we sought to examine whether the small-molecule MLK3 inhibitor URMC099 would be effective in reversing diet-induced murine NASH. C57BL/6J mice were fed either a diet high in saturated fat, fructose, and cholesterol (FFC), or a chow diet for 24 weeks. Mice were treated with either URMC099 (10 mg/kg) twice daily by intraperitoneal injection or its vehicle during the last 2 weeks of the feeding study. FFC-fed mice receiving URMC099 had similar body weight, caloric intake, homeostatic model assessment of insulin resistance, metabolic phenotype, and hepatic steatosis compared with vehicle-treated mice. Furthermore, FFC-fed mice treated with URMC099 had less hepatic macrophage infiltration, activation, and proinflammatory polarization, as well as less liver injury and fibrosis when compared with vehicle-treated mice. In conclusion, URMC099 is well tolerated in mice without obvious toxicities and appears to be efficacious in reversing diet-induced NASH. Hence, URMC099 may serve as a therapeutic agent in human NASH.
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Hirsova P, Weng P, Salim W, Bronk SF, Griffith TS, Ibrahim SH, Gores GJ. TRAIL Deletion Prevents Liver, but Not Adipose Tissue, Inflammation during Murine Diet-Induced Obesity. Hepatol Commun 2017; 1:648-662. [PMID: 29124251 PMCID: PMC5673124 DOI: 10.1002/hep4.1069] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Tumor necrosis factor‐related apoptosis‐inducing ligand (TRAIL) and its cognate receptor(s) are up‐regulated in human and murine nonalcoholic steatohepatitis (NASH); however, the consequence of this enhanced expression on NASH pathogenesis remains unclear. TRAIL may either accentuate liver injury by promoting hepatic steatosis and inflammation or it may mitigate the disease process by improving systemic insulin resistance and averting hepatic fibrosis. Herein, we investigated the role of TRAIL in an obesity‐induced murine model of NASH. C57BL/6 wild‐type mice and Trail–/– mice were placed on a 20‐week standard chow or a high‐fat, high‐fructose, and high‐cholesterol (FFC) diet, which induces obesity, insulin resistance, and NASH. Metabolic phenotype, liver injury, inflammation and fibrosis, and adipose tissue homeostasis were examined. FFC diet‐fed Trail–/– mice displayed no difference in weight gain and metabolic profile when compared to wild‐type mice on the same diet. All FFC‐fed mice developed significant hepatic steatosis, which was attenuated in Trail–/– mice. TRAIL deficiency also significantly decreased FFC diet‐induced liver injury as manifested by reduced serum alanine aminotransferase values, hepatic terminal deoxynucleotidyl transferase‐mediated deoxyuridine triphosphate nick‐end labeling‐positive cells, and macrophage‐associated inflammation. FFC diet‐associated hepatic stellate cell activation and hepatic collagen deposition were also abrogated in Trail–/– mice. In contrast to the liver, TRAIL deletion did not improve FFC diet‐induced adipose tissue injury and inflammation and actually aggravated insulin resistance. Conclusion: NASH pathogenesis may be dissociated from other features of the metabolic syndrome, and liver‐targeted inhibition of TRAIL signaling may be salutary. (Hepatology Communications 2017;1:648–662)
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Mauer AS, Hirsova P, Maiers JL, Shah VH, Malhi H. Inhibition of sphingosine 1-phosphate signaling ameliorates murine nonalcoholic steatohepatitis. Am J Physiol Gastrointest Liver Physiol 2017; 312:G300-G313. [PMID: 28039158 PMCID: PMC5401989 DOI: 10.1152/ajpgi.00222.2016] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Revised: 11/28/2016] [Accepted: 12/11/2016] [Indexed: 01/31/2023]
Abstract
Nonalcoholic steatohepatitis (NASH) is a lipotoxic disorder, wherein proinflammatory lipids, such as ceramide and its derivative sphingosine 1-phosphate (S1P), contribute to macrophage-associated liver inflammation. For example, we have previously demonstrated a role for S1P in steatotic hepatocyte-derived S1P-enriched extracellular vesicles in macrophage chemotaxis in vitro. Therefore, we hypothesized that FTY720, an S1P antagonist, would ameliorate NASH by inhibiting proinflammatory monocyte chemotaxis. To test our hypothesis, NASH was established in C57BL/6 male mice by feeding a diet high in fructose, saturated fat, and cholesterol for 22 wk. Then mice received daily intraperitoneal injections of FTY720 for 2 wk before analysis of liver injury, inflammation, and fibrosis. FTY720-treated mice with NASH demonstrated improved liver histology with a significant reduction in hepatocyte ballooning and inflammatory foci. Hepatomegaly was reversed, and liver triglycerides were reduced following FTY720 administration to mice with NASH. Correspondingly, serum ALT levels, hepatic inflammatory macrophage accumulation, and the expression of Ly6C in recruited myeloid cells was reduced in FTY720-treated mice. Hepatic collagen accumulation and expression of α-smooth muscle actin were significantly lowered as well. Body composition, energy consumption and utilization, and hepatic sphingolipid composition remained unchanged following FTY720 administration. FTY720 ameliorates murine nonalcoholic steatohepatitis. Reduction in liver injury and inflammation is associated with a reduction in hepatic macrophage accumulation, likely due to dampened recruitment of circulating myeloid cells into the liver. Nonalcoholic steatohepatitis may be a novel indication for the therapeutic use of FTY720.NEW & NOTEWORTHY There are no approved pharmacologic therapies for nonalcoholic steatohepatitis (NASH), the leading cause of chronic liver disease worldwide. This study describes the use of FTY720, a novel small molecule, for the amelioration of NASH in a mouse model. We demonstrate that 2-wk administration of FTY720 to mice with NASH led to a reduction in liver injury, inflammation, and fibrosis. These data provide a preclinical rationale for studying this drug in human NASH.
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