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Journal of Hepatology Oct 2020Non-alcoholic steatohepatitis (NASH) is a chronic liver disease characterized by hepatic lipid accumulation, inflammation, and progressive fibrosis. Acetyl-CoA...
BACKGROUND & AIMS
Non-alcoholic steatohepatitis (NASH) is a chronic liver disease characterized by hepatic lipid accumulation, inflammation, and progressive fibrosis. Acetyl-CoA carboxylase (ACC) catalyzes the rate-limiting step of de novo lipogenesis and regulates fatty acid β-oxidation in hepatocytes. ACC inhibition reduces hepatic fat content and markers of liver injury in patients with NASH; however, the effect of ACC inhibition on liver fibrosis has not been reported.
METHODS
A direct role for ACC in fibrosis was evaluated by measuring de novo lipogenesis, procollagen production, gene expression, glycolysis, and mitochondrial respiration in hepatic stellate cells (HSCs) in the absence or presence of small molecule inhibitors of ACC. ACC inhibitors were evaluated in rodent models of liver fibrosis induced by diet or the hepatotoxin, diethylnitrosamine. Fibrosis and hepatic steatosis were evaluated by histological and biochemical assessments.
RESULTS
Inhibition of ACC reduced the activation of TGF-β-stimulated HSCs, as measured by both α-SMA expression and collagen production. ACC inhibition prevented a metabolic switch necessary for induction of glycolysis and oxidative phosphorylation during HSC activation. While the molecular mechanism by which inhibition of de novo lipogenesis blocks glycolysis and oxidative phosphorylation is unknown, we definitively show that HSCs require de novo lipogenesis for activation. Consistent with this direct antifibrotic mechanism in HSCs, ACC inhibition reduced liver fibrosis in a rat choline-deficient, high-fat diet model and in response to chronic diethylnitrosamine-induced liver injury (in the absence of hepatic lipid accumulation).
CONCLUSIONS
In addition to reducing lipid accumulation in hepatocytes, ACC inhibition also directly impairs the profibrogenic activity of HSCs. Thus, small molecule inhibitors of ACC may lessen fibrosis by reducing lipotoxicity in hepatocytes and by preventing HSC activation, providing a mechanistic rationale for the treatment of patients with advanced liver fibrosis due to NASH.
LAY SUMMARY
Hepatic fibrosis is the most important predictor of liver-related outcomes in patients with non-alcoholic steatohepatitis (NASH). Small molecule inhibitors of acetyl-CoA carboxylase (ACC) reduce hepatic fat content and markers of liver injury in patients with NASH. Herein, we report that inhibition of ACC and de novo lipogenesis also directly suppress the activation of hepatic stellate cells - the primary cell responsible for generating fibrotic scar in the liver - and thus fibrosis. These data provide further evidence for the use of ACC inhibitors to treat patients with NASH and advanced fibrosis.
Topics: Acetyl-CoA Carboxylase; Animals; Biomarkers; Cell Line; Diet, High-Fat; Disease Models, Animal; Hepatic Stellate Cells; Humans; Lipogenesis; Liver; Liver Cirrhosis; Male; Mice; Mice, Inbred C57BL; Non-alcoholic Fatty Liver Disease; Rats; Rats, Wistar
PubMed: 32376414
DOI: 10.1016/j.jhep.2020.04.037 -
Revista Espanola de Enfermedades... Nov 2019We have read with great interest the study by Vera MC et al. on the intrasplenic transplantation of hepatocytes from donors receiving the carcinogenic drugs...
We have read with great interest the study by Vera MC et al. on the intrasplenic transplantation of hepatocytes from donors receiving the carcinogenic drugs diethylnitrosamine (DEN) and 2-actylaminofluorene (2-AAF). The most important conclusion of the study is that there were no signs of tumor progression in the recipient liver at seven and 60 days after hepatocellular transplantation and no differences were found in the animals with healthy hepatocyte transplants.
Topics: 2-Acetylaminofluorene; Animals; Diethylnitrosamine; Hepatocytes; Liver; Rats; Rats, Wistar
PubMed: 31663360
DOI: 10.17235/reed.2019.6270/2019 -
Nature Communications Sep 2023CSCs (Cancer stem cells) with distinct metabolic features are considered to cause HCC (hepatocellular carcinoma) initiation, metastasis and therapeutic resistance. Here,...
CSCs (Cancer stem cells) with distinct metabolic features are considered to cause HCC (hepatocellular carcinoma) initiation, metastasis and therapeutic resistance. Here, we perform a metabolic gene CRISPR/Cas9 knockout library screen in tumorspheres derived from HCC cells and find that deletion of SCARB2 suppresses the cancer stem cell-like properties of HCC cells. Knockout of Scarb2 in hepatocytes attenuates HCC initiation and progression in both MYC-driven and DEN (diethylnitrosamine)-induced HCC mouse models. Mechanistically, binding of SCARB2 with MYC promotes MYC acetylation by interfering with HDCA3-mediated MYC deacetylation on lysine 148 and subsequently enhances MYC transcriptional activity. Screening of a database of FDA (Food and Drug Administration)-approved drugs shows Polymyxin B displays high binding affinity for SCARB2 protein, disrupts the SCARB2-MYC interaction, decreases MYC activity, and reduces the tumor burden. Our study identifies SCARB2 as a functional driver of HCC and suggests Polymyxin B-based treatment as a targeted therapeutic option for HCC.
Topics: Animals; Mice; Carcinoma, Hepatocellular; Liver Neoplasms; Neoplastic Stem Cells; Polymyxin B; Humans
PubMed: 37739936
DOI: 10.1038/s41467-023-41593-z -
Hepatology (Baltimore, Md.) Sep 2021Human transmembrane 6 superfamily 2 (TM6SF2) variant rs58542926 is associated with NAFLD and HCC. However, conflicting reports in germline Tm6sf2 knockout mice suggest...
BACKGROUND AND AIMS
Human transmembrane 6 superfamily 2 (TM6SF2) variant rs58542926 is associated with NAFLD and HCC. However, conflicting reports in germline Tm6sf2 knockout mice suggest no change or decreased very low density lipoprotein (VLDL) secretion and either unchanged or increased hepatic steatosis, with no increased fibrosis. We generated liver-specific Tm6Sf2 knockout mice (Tm6 LKO) to study VLDL secretion and the impact on development and progression of NAFLD.
APPROACH AND RESULTS
Two independent lines of Tm6 LKO mice exhibited spontaneous hepatic steatosis. Targeted lipidomic analyses showed increased triglyceride species whose distribution and abundance phenocopied findings in mice with liver-specific deletion of microsomal triglyceride transfer protein. The VLDL triglyceride secretion was reduced with small, underlipidated particles and unchanged or increased apolipoprotein B. Liver-specific adeno-associated viral, serotype 8 (AAV8) rescue using either wild-type or mutant E167K-Tm6 reduced hepatic steatosis and improved VLDL secretion. The Tm6 LKO mice fed a high milk-fat diet for 3 weeks exhibited increased steatosis and fibrosis, and those phenotypes were further exacerbated when mice were fed fibrogenic, high fat/fructose diets for 20 weeks. In two models of HCC, either neonatal mice injected with streptozotocin (NASH/STAM) and high-fat fed or with diethylnitrosamine injection plus fibrogenic diet feeding, Tm6 LKO mice exhibited increased steatosis, greater tumor burden, and increased tumor area versus Tm6 flox controls. Additionally, diethylnitrosamine-injected and fibrogenic diet-fed Tm6 LKO mice administered wild-type Tm6 or E167K-mutant Tm6 AAV8 revealed significant tumor attenuation, with tumor burden inversely correlated with Tm6 protein levels.
CONCLUSIONS
Liver-specific Tm6sf2 deletion impairs VLDL secretion, promoting hepatic steatosis, fibrosis, and accelerated development of HCC, which was mitigated with AAV8- mediated rescue.
Topics: Animals; Carcinoma, Hepatocellular; Fatty Liver; Lipidomics; Lipoproteins, VLDL; Liver; Liver Cirrhosis; Liver Neoplasms; Membrane Proteins; Mice; Mice, Knockout; Non-alcoholic Fatty Liver Disease; Triglycerides
PubMed: 33638902
DOI: 10.1002/hep.31771 -
Gut Jul 2021Hepatocellular carcinoma (HCC) is a prevalent and aggressive cancer usually arising on a background of chronic liver injury involving inflammatory and hepatic...
OBJECTIVE
Hepatocellular carcinoma (HCC) is a prevalent and aggressive cancer usually arising on a background of chronic liver injury involving inflammatory and hepatic regenerative processes. The triggering receptor expressed on myeloid cells 2 (TREM-2) is predominantly expressed in hepatic non-parenchymal cells and inhibits Toll-like receptor signalling, protecting the liver from various hepatotoxic injuries, yet its role in liver cancer is poorly defined. Here, we investigated the impact of TREM-2 on liver regeneration and hepatocarcinogenesis.
DESIGN
TREM-2 expression was analysed in liver tissues of two independent cohorts of patients with HCC and compared with control liver samples. Experimental HCC and liver regeneration models in wild type and mice, and studies with hepatic stellate cells (HSCs) and HCC spheroids were conducted.
RESULTS
expression was upregulated in human HCC tissue, in mouse models of liver regeneration and HCC. mice developed more liver tumours irrespective of size after diethylnitrosamine (DEN) administration, displayed exacerbated liver damage, inflammation, oxidative stress and hepatocyte proliferation. Administering an antioxidant diet blocked DEN-induced hepatocarcinogenesis in both genotypes. Similarly, animals developed more and larger tumours in fibrosis-associated HCC models. livers showed increased hepatocyte proliferation and inflammation after partial hepatectomy. Conditioned media from human HSCs overexpressing TREM-2 inhibited human HCC spheroid growth through attenuated Wnt ligand secretion.
CONCLUSION
TREM-2 plays a protective role in hepatocarcinogenesis via different pleiotropic effects, suggesting that TREM-2 agonism should be investigated as it might beneficially impact HCC pathogenesis in a multifactorial manner.
Topics: Adult; Aged; Animals; Carcinogenesis; Carcinoma, Hepatocellular; Cell Line, Tumor; Cell Proliferation; Diethylnitrosamine; Female; Gain of Function Mutation; Gene Expression; Hepatic Stellate Cells; Hepatitis; Hepatocytes; Humans; Liver; Liver Cirrhosis; Liver Neoplasms; Liver Regeneration; Macrophages; Male; Membrane Glycoproteins; Mice; Mice, Knockout; Middle Aged; Oxidative Stress; Protective Factors; RNA; Reactive Oxygen Species; Receptors, Immunologic; Spheroids, Cellular; Up-Regulation; Wnt Proteins; Wnt Signaling Pathway; Wnt3 Protein
PubMed: 32907830
DOI: 10.1136/gutjnl-2019-319227 -
Cell Death & Disease Sep 2023Hepatocarcinogenesis is initiated by repeated hepatocyte death and liver damage, and the underlying mechanisms mediating cell death and the subsequent carcinogenesis...
Hepatocarcinogenesis is initiated by repeated hepatocyte death and liver damage, and the underlying mechanisms mediating cell death and the subsequent carcinogenesis remain to be fully investigated. Immunoresponsive gene 1 (IRG1) and its enzymatic metabolite itaconate are known to suppress inflammation in myeloid cells, and its expression in liver parenchymal hepatocytes is currently determined. However, the potential roles of IRG1 in hepatocarcinogenesis are still unknown. Here, using the diethylnitrosamine (DEN)-induced hepatocarcinogenesis mouse model, we found that IRG1 expression in hepatocytes was markedly induced upon DEN administration. The DEN-induced IRG1 was then determined to promote the intrinsic mitochondrial apoptosis of hepatocytes and liver damage, thus enhancing the subsequent hepatocarcinogenesis. Mechanistically, the mitochondrial IRG1 could associate and trap anti-apoptotic MCL-1 to inhibit the interaction between MCL-1 and pro-apoptotic Bim, thus promoting Bim activation and downstream Bax mitochondrial translocation, and then releasing cytochrome c and initiating apoptosis. Thus, the inducible mitochondrial IRG1 promotes hepatocyte apoptosis and the following hepatocarcinogenesis, which provides mechanistic insight and a potential target for preventing liver injury and HCC.
Topics: Animals; Mice; Apoptosis; Carcinogenesis; Carcinoma, Hepatocellular; Hepatocytes; Liver Neoplasms; Myeloid Cell Leukemia Sequence 1 Protein
PubMed: 37737207
DOI: 10.1038/s41419-023-06155-7 -
Cells Dec 2021Liver fibrosis is a complex process characterized by the excessive accumulation of extracellular matrix (ECM) and an alteration in liver architecture, as a result of...
Liver fibrosis is a complex process characterized by the excessive accumulation of extracellular matrix (ECM) and an alteration in liver architecture, as a result of most types of chronic liver diseases such as cirrhosis, hepatocellular carcinoma (HCC) and liver failure. Maresin-1 (MaR1) is derivative of ω-3 docosahexaenoic acid (DHA), which has been shown to have pro-resolutive and anti-inflammatory effects. We tested the hypothesis that the application of MaR1 could prevent the development of fibrosis in an animal model of chronic hepatic damage. Sprague-Dawley rats were induced with liver fibrosis by injections of diethylnitrosamine (DEN) and treated with or without MaR1 for four weeks. In the MaR1-treated animals, levels of AST and ALT were normalized in comparison with DEN alone, the hepatic architecture was improved, and inflammation and necrotic areas were reduced. Cell proliferation, assessed by the mitotic activity index and the expression of Ki-67, was increased in the MaR1-treated group. MaR1 attenuated liver fibrosis and oxidative stress was induced by DEN. Plasma levels of the pro-inflammatory mediators TNF-α and IL-1β were reduced in MaR1-treated animals, whereas the levels of IL-10, an anti-inflammatory cytokine, increased. Interestingly, MaR1 inhibited the translocation of the p65 subunit of NF-κB, while increasing the activation of Nrf2, a key regulator of the antioxidant response. Finally, MaR1 treatment reduced the levels of the pro-fibrotic mediator TGF-β and its receptor, while normalizing the hepatic levels of IGF-1, a proliferative agent. Taken together, these results suggest that MaR1 improves the parameters of DEN-induced liver fibrosis, activating hepatocyte proliferation and decreasing oxidative stress and inflammation. These results open the possibility of MaR1 as a potential therapeutic agent in fibrosis and other liver pathologies.
Topics: Animals; Apoptosis; Body Weight; Cell Cycle; Cell Proliferation; Cytokines; Diethylnitrosamine; Docosahexaenoic Acids; Extracellular Matrix; Inflammation; Inflammation Mediators; Intercellular Signaling Peptides and Proteins; Liver; Liver Cirrhosis; Male; NF-E2-Related Factor 2; NF-kappa B; Organ Size; Oxidative Stress; Rats, Sprague-Dawley; Receptors, Cytoplasmic and Nuclear; Rats
PubMed: 34943914
DOI: 10.3390/cells10123406 -
Gastroenterology Jul 2024Hepatocellular carcinoma (HCC) is characterized by an immune-suppressive microenvironment, which contributes to tumor progression, metastasis, and immunotherapy...
BACKGROUND & AIMS
Hepatocellular carcinoma (HCC) is characterized by an immune-suppressive microenvironment, which contributes to tumor progression, metastasis, and immunotherapy resistance. Identification of HCC-intrinsic factors regulating the immunosuppressive microenvironment is urgently needed. Here, we aimed to elucidate the role of SYR-Related High-Mobility Group Box 18 (SOX18) in inducing immunosuppression and to validate novel combination strategies for SOX18-mediated HCC progression and metastasis.
METHODS
The role of SOX18 in HCC was investigated in orthotopic allografts and diethylinitrosamine/carbon tetrachloride-induced spontaneous models by using murine cell lines, adeno-associated virus 8, and hepatocyte-specific knockin and knockout mice. The immune cellular composition in the HCC microenvironment was evaluated by flow cytometry and immunofluorescence.
RESULTS
SOX18 overexpression promoted the infiltration of tumor-associated macrophages (TAMs) and regulatory T cells (Tregs) while diminishing cytotoxic T cells to facilitate HCC progression and metastasis in cell-derived allografts and chemically induced HCC models. Mechanistically, transforming growth factor-beta 1 (TGF-β1) upregulated SOX18 expression by activating the Smad2/3 complex. SOX18 transactivated chemokine (C-X-C motif) ligand 12 (CXCL12) and programmed death ligand 1 (PD-L1) to induce the immunosuppressive microenvironment. CXCL12 knockdown significantly attenuated SOX18-induced TAMs and Tregs accumulation and HCC dissemination. Antagonism of chemokine receptor 4 (CXCR4), the cognate receptor of CXCL12, or selective knockout of CXCR4 in TAMs or Tregs likewise abolished SOX18-mediated effects. TGFβR1 inhibitor Vactosertib or CXCR4 inhibitor AMD3100 in combination with anti-PD-L1 dramatically inhibited SOX18-mediated HCC progression and metastasis.
CONCLUSIONS
SOX18 promoted the accumulation of immunosuppressive TAMs and Tregs in the microenvironment by transactivating CXCL12 and PD-L1. CXCR4 inhibitor or TGFβR1 inhibitor in synergy with anti-PD-L1 represented a promising combination strategy to suppress HCC progression and metastasis.
Topics: Animals; Carcinoma, Hepatocellular; Liver Neoplasms; SOXF Transcription Factors; B7-H1 Antigen; Tumor Microenvironment; Humans; Receptors, CXCR4; Transforming Growth Factor beta1; Mice; Disease Progression; Chemokine CXCL12; Up-Regulation; Cyclams; Benzylamines; T-Lymphocytes, Regulatory; Cell Line, Tumor; Tumor-Associated Macrophages; Mice, Knockout; Gene Expression Regulation, Neoplastic; Signal Transduction; Immune Checkpoint Inhibitors; Mice, Inbred C57BL; Diethylnitrosamine; Male
PubMed: 38417530
DOI: 10.1053/j.gastro.2024.02.025 -
Stem Cell Research & Therapy Oct 2022Hepatic fibrosis is a common pathologic stage in chronic liver disease development, which might ultimately lead to liver cirrhosis. Accumulating evidence suggests that...
ADSCs-derived exosomes ameliorate hepatic fibrosis by suppressing stellate cell activation and remodeling hepatocellular glutamine synthetase-mediated glutamine and ammonia homeostasis.
BACKGROUND
Hepatic fibrosis is a common pathologic stage in chronic liver disease development, which might ultimately lead to liver cirrhosis. Accumulating evidence suggests that adipose-derived stromal cells (ADSCs)-based therapies show excellent therapeutic potential in liver injury disease owing to its superior properties, including tissue repair ability and immunomodulation effect. However, cell-based therapy still limits to several problems, such as engraftment efficiency and immunoreaction, which impede the ADSCs-based therapeutics development. So, ADSCs-derived extracellular vesicles (EVs), especially for exosomes (ADSC-EXO), emerge as a promise cell-free therapeutics to ameliorate liver fibrosis. The effect and underlying mechanisms of ADSC-EXO in liver fibrosis remains blurred.
METHODS
Hepatic fibrosis murine model was established by intraperitoneal sequential injecting the diethylnitrosamine (DEN) for two weeks and then carbon tetrachloride (CCl) for six weeks. Subsequently, hepatic fibrosis mice were administrated with ADSC-EXO (10 μg/g) or PBS through tail vein infusion for three times in two weeks. To evaluate the anti-fibrotic capacity of ADSC-EXO, we detected liver morphology by histopathological examination, ECM deposition by serology test and Sirius Red staining, profibrogenic markers by qRT-PCR assay. LX-2 cells treated with TGF-β (10 ng/ml) for 12 h were conducted for evaluating ADSC-EXO effect on activated hepatic stellate cells (HSCs). RNA-seq was performed for further analysis of the underlying regulatory mechanisms of ADSC-EXO in liver fibrosis.
RESULTS
In this study, we obtained isolated ADSCs, collected and separated ADSCs-derived exosomes. We found that ADSC-EXO treatment could efficiently ameliorate DEN/CCl-induced hepatic fibrosis by improving mice liver function and lessening hepatic ECM deposition. Moreover, ADSC-EXO intervention could reverse profibrogenic phenotypes both in vivo and in vitro, including HSCs activation depressed and profibrogenic markers inhibition. Additionally, RNA-seq analysis further determined that decreased glutamine synthetase (Glul) of perivenous hepatocytes in hepatic fibrosis mice could be dramatically up-regulated by ADSC-EXO treatment; meanwhile, glutamine and ammonia metabolism-associated key enzyme OAT was up-regulated and GLS2 was down-regulated by ADSC-EXO treatment in mice liver. In addition, glutamine synthetase inhibitor would erase ADSC-EXO therapeutic effect on hepatic fibrosis.
CONCLUSIONS
These findings demonstrated that ADSC-derived exosomes could efficiently alleviate hepatic fibrosis by suppressing HSCs activation and remodeling glutamine and ammonia metabolism mediated by hepatocellular glutamine synthetase, which might be a novel and promising anti-fibrotic therapeutics for hepatic fibrosis disease.
Topics: Ammonia; Animals; Carbon Tetrachloride; Carcinoma, Hepatocellular; Diethylnitrosamine; Exosomes; Fibrosis; Glutamate-Ammonia Ligase; Glutamine; Hepatic Stellate Cells; Homeostasis; Liver Cirrhosis; Liver Neoplasms; Mice; Stromal Cells; Transforming Growth Factor beta
PubMed: 36195966
DOI: 10.1186/s13287-022-03049-x -
Hepatology (Baltimore, Md.) May 2023Nonalcoholic fatty liver disease and its progressive form, nonalcoholic steatohepatitis (NASH), are rapidly becoming the top causes of hepatocellular carcinoma (HCC)....
BACKGROUND AND AIMS
Nonalcoholic fatty liver disease and its progressive form, nonalcoholic steatohepatitis (NASH), are rapidly becoming the top causes of hepatocellular carcinoma (HCC). Currently, there are no approved therapies for the treatment of NASH. DEAD-box protein 5 (DDX5) plays important roles in different cellular processes. However, the precise role of DDX5 in NASH remains unclear.
APPROACH AND RESULTS
DDX5 expression was downregulated in patients with NASH, mouse models with diet-induced NASH (high-fat diet [HFD], methionine- and choline-deficient diet, and choline-deficient HFD), mouse models with NASH-HCC (diethylnitrosamine with HFD), and palmitic acid-stimulated hepatocytes. Adeno-associated virus-mediated DDX5 overexpression ameliorates hepatic steatosis and inflammation, whereas its deletion worsens such pathology. The untargeted metabolomics analysis was carried out to investigate the mechanism of DDX5 in NASH and NASH-HCC, which suggested the regulatory effect of DDX5 on lipid metabolism. DDX5 inhibits mechanistic target of rapamycin complex 1 (mTORC1) activation by recruiting the tuberous sclerosis complex (TSC)1/2 complex to mTORC1, thus improving lipid metabolism and attenuating the NACHT-, leucine-rich-repeat (LRR)-, and pyrin domain (PYD)-containing protein 3 inflammasome activation. We further identified that the phytochemical compound hyperforcinol K directly interacted with DDX5 and prevented its ubiquitinated degradation mediated by ubiquitin ligase (E3) tripartite motif protein 5, thereby significantly reducing lipid accumulation and inflammation in a NASH mouse model.
CONCLUSIONS
These findings provide mechanistic insight into the role of DDX5 in mTORC1 regulation and NASH progression, as well as suggest a number of targets and a promising lead compound for therapeutic interventions against NASH.
Topics: Mice; Animals; Non-alcoholic Fatty Liver Disease; Carcinoma, Hepatocellular; Mechanistic Target of Rapamycin Complex 1; Liver Neoplasms; Inflammation; Diet, High-Fat; Choline; DEAD-box RNA Helicases; Mice, Inbred C57BL; Liver; Disease Models, Animal
PubMed: 35796622
DOI: 10.1002/hep.32651