scholarly journals Transcriptional repression of SIRT1 by protein inhibitor of activated STAT 4 (PIAS4) in hepatic stellate cells contributes to liver fibrosis

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Lina Sun ◽  
Zhiwen Fan ◽  
Junliang Chen ◽  
Wenfang Tian ◽  
Min Li ◽  
...  
Keyword(s):  
Liver Fibrosis ◽  
Hepatic Stellate Cells ◽  
High Glucose ◽  
Interstitial Fibrosis ◽  
Stellate Cells ◽  
Quiescent State ◽  
Dependent Manner ◽  
Gene Promoters ◽  
Sirt1 Expression ◽  
Primary Mouse

Abstract Interstitial fibrosis represents a key pathological process in non-alcoholic steatohepatitis (NASH). In the liver, fibrogenesis is primarily mediated by activated hepatic stellate cells (HSCs) transitioning from a quiescent state in response to a host of stimuli. The molecular mechanism underlying HSC activation is not completely understood. Here we report that there was a simultaneous up-regulation of PIAS4 expression and down-regulation of SIRT1 expression accompanying increased hepatic fibrogenesis in an MCD-diet induced mouse model of NASH. In cultured primary mouse HSCs, stimulation with high glucose activated PIAS4 while at the same time repressed SIRT1. Over-expression of PIAS4 directly repressed SIRT1 promoter activity. In contrast, depletion of PIAS4 restored SIRT1 expression in HSCs treated with high glucose. Estrogen, a known NASH-protective hormone, antagonized HSC activation by targeting PIAS4. Lentivirus-mediated delivery of short hairpin RNA (shRNA) targeting PIAS4 in mice ameliorated MCD diet induced liver fibrosis by normalizing SIRT1 expression in vivo. PIAS4 promoted HSC activation in a SIRT1-dependent manner in vitro. Mechanistically, PIAS4 mediated SIRT1 repression led to SMAD3 hyperacetylation and enhanced SMAD3 binding to fibrogenic gene promoters. Taken together, our data suggest SIRT1 trans-repression by PIAS4 plays an important role in HSC activation and liver fibrosis.

Norepinephrine induces calcium spikes and proinflammatory actions in human hepatic stellate cells

2006 ◽  
Vol 291 (5) ◽  
pp. G877-G884 ◽  
Author(s):  
Pau Sancho-Bru ◽  
Ramón Bataller ◽  
Jordi Colmenero ◽  
Xavier Gasull ◽  
Montserrat Moreno ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Portal Hypertension ◽  
Liver Fibrosis ◽  
Hepatic Stellate Cells ◽  
Molecular Mechanisms ◽  
Nuclear Translocation ◽  
Stellate Cells ◽  
Luciferase Reporter ◽  
Dependent Manner ◽  
Cell Contraction

Catecholamines participate in the pathogenesis of portal hypertension and liver fibrosis through α1-adrenoceptors. However, the underlying cellular and molecular mechanisms are largely unknown. Here, we investigated the effects of norepinephrine (NE) on human hepatic stellate cells (HSC), which exert vasoactive, inflammatory, and fibrogenic actions in the injured liver. Adrenoceptor expression was assessed in human HSC by RT-PCR and immunocytochemistry. Intracellular Ca2+ concentration ([Ca2+]i) was studied in fura-2-loaded cells. Cell contraction was studied by assessing wrinkle formation and myosin light chain II (MLC II) phosphorylation. Cell proliferation and collagen-α1(I) expression were assessed by [3H]thymidine incorporation and quantitative PCR, respectively. NF-κB activation was assessed by luciferase reporter gene and p65 nuclear translocation. Chemokine secretion was assessed by ELISA. Normal human livers expressed α1A-adrenoceptors, which were markedly upregulated in livers with advanced fibrosis. Activated human HSC expressed α1A-adrenoceptors. NE induced multiple rapid [Ca2+]i oscillations (Ca2+ spikes). Prazosin (α1-blocker) completely prevented NE-induced Ca2+ spikes, whereas propranolol (nonspecific β-blocker) partially attenuated this effect. NE caused phosphorylation of MLC II and cell contraction. In contrast, NE did not affect cell proliferation or collagen-α1(I) expression. Importantly, NE stimulated the secretion of inflammatory chemokines (RANTES and interleukin-8) in a dose-dependent manner. Prazosin blocked NE-induced chemokine secretion. NE stimulated NF-κB activation. BAY 11-7082, a specific NF-κB inhibitor, blocked NE-induced chemokine secretion. We conclude that NE stimulates NF-κB and induces cell contraction and proinflammatory effects in human HSC. Catecholamines may participate in the pathogenesis of portal hypertension and liver fibrosis by targeting HSC.

scholarly journals Inflammasome-mediated regulation of hepatic stellate cells

2009 ◽  
Vol 296 (6) ◽  
pp. G1248-G1257 ◽  
Author(s):  
Azuma Watanabe ◽  
Muhammad Adnan Sohail ◽  
Dawidson Assis Gomes ◽  
Ardeshir Hashmi ◽  
Jun Nagata ◽  
...  
Keyword(s):  
Liver Fibrosis ◽  
Immune Cells ◽  
Hepatic Stellate Cells ◽  
Smooth Muscle Actin ◽  
Stellate Cells ◽  
Inflammasome Activation ◽  
Cellular Injury ◽  
Wild Type ◽  
Primary Mouse ◽  
Msu Crystals

The inflammasome is a cytoplasmic multiprotein complex that has recently been identified in immune cells as an important sensor of signals released by cellular injury and death. Analogous to immune cells, hepatic stellate cells (HSC) also respond to cellular injury and death. Our aim was to establish whether inflammasome components were present in HSC and could regulate HSC functionality. Monosodium urate (MSU) crystals (100 μg/ml) were used to experimentally induce inflammasome activation in LX-2 and primary mouse HSC. Twenty-four hours later primary mouse HSC were stained with α-smooth muscle actin and visualized by confocal microscopy, and TGF-β and collagen1 mRNA expression was quantified. LX-2 cells were further cultured with or without MSU crystals for 24 h in a transwell chemotaxis assay with PDGF as the chemoattractant. We also examined inhibition of calcium (Ca2+) signaling in LX-2 cells treated with or without MSU crystals using caged inositol 1,4,5-triphosphate (IP3). Finally, we confirmed an important role of the inflammasome in experimental liver fibrosis by the injection of carbon tetrachloride (CCl4) or thioacetamide (TAA) in wild-type mice and mice lacking components of the inflammasome. Components of the inflammasome are expressed in LX-2 cells and primary HSC. MSU crystals induced upregulation of TGF-β and collagen1 mRNA and actin reorganization in HSCs from wild-type mice but not mice lacking inflammasome components. MSU crystals inhibited the release of Ca2+ via IP3 in LX-2 cells and also inhibited PDGF-induced chemotaxis. Mice lacking the inflammasome-sensing and adaptor molecules, NLRP3 and apoptosis-associated speck-like protein containing CARD, had reduced CCl4 and TAA-induced liver fibrosis. We concluded that inflammasome components are present in HSC, can regulate a variety of HSC functions, and are required for the development of liver fibrosis.

scholarly journals Astaxanthin Attenuates the Changes in the Expression of miRNAs Involved in the Activation of Hepatic Stellate Cells (P02-011-19)

2019 ◽  
Vol 3 (Supplement_1) ◽  
Author(s):  
Minkyung Bae ◽  
Ji-Young Lee
Keyword(s):  
Liver Fibrosis ◽  
Mirna Expression ◽  
Hepatic Stellate Cells ◽  
Expression Profiles ◽  
Stellate Cells ◽  
Expression Levels ◽  
Candidate Mirnas ◽  
Primary Mouse ◽  
Mirna Expression Profiles ◽  
Human Hscs

Abstract Objectives MicroRNAs (miRNAs) are known to be associated with human diseases, including liver fibrosis. We previously demonstrated that astaxanthin (ASTX), a xanthophyll carotenoid, has anti-fibrogenic effects in hepatic stellate cells (HSCs). HSCs are the major cell type responsible for the accumulation of extracellular matrix during the development of liver fibrosis once they are activated. The objective of this study was to compare miRNA expression profiles in activated HSCs (aHSCs) with those of quiescent HSCs (qHSCs) to identify miRNAs that may play crucial roles in the activation of HSCs. We also determined the effect of ASTX on the changes in miRNAs during HSC activation. Methods Primary mouse HSCs were cultured on uncoated plastic dishes for activation. The cells cultured for 1 day and 7 days after isolation served as qHSCs and aHSCs, respectively. qHSCs were treated with/without 25 µM ASTX during the activation for 7 days. miRNA expression profiles were determined using a miScript miRNA PCR array for mouse fibrosis. miRNAs whose expression were altered by more than 2-folds during HSC activation and by ASTX were selected. Their expression levels were further confirmed by quantitative real-time PCR in primary mouse and human HSCs and LX-2 cells, a human HSC cell line. Results Compared with qHSCs, the expression levels of 14 miRNAs and 23 miRNAs were increased and decreased by more than 2-folds, respectively, in aHSCs. Among 14 miRNAs increased in aHSCs, the expression of miR-192–5p, miR-382–5p, and miR-874–3p was reduced by ASTX. In addition, ASTX increased the expression of miR-19a-3p, miR-19b-3p, and miR-101a-3p which were among the 23 miRNAs that were decreased in aHSCs. Of the selected 6 miRNAs, miR-382–5p was chosen for further analysis based on its high expression in HSCs and the magnitude of differences between groups. Unlike in primary mouse HSCs, the expression of miR-382–5p was not altered by transforming growth factor β1, a fibrogenic cytokine, or by ASTX in primary human HSCs and LX-2 cells, which are cells somewhat activated. Conclusions We identified candidate miRNAs that may be important for the activation of HSCs from qHSCs, which were also sensitive to ASTX. Of the candidate miRNAs, miR-382–5p is likely involved in the early stage of HSC activation, i.e., transdifferentiation of qHSCs to aHSCs. Funding Sources NIH.

scholarly journals Transcriptional factor ATF3 promotes liver fibrosis via activating hepatic stellate cells

2020 ◽  
Vol 11 (12) ◽  
Author(s):  
Zhemin Shi ◽  
Kun Zhang ◽  
Ting Chen ◽  
Yu Zhang ◽  
Xiaoxiao Du ◽  
...  
Keyword(s):  
Liver Fibrosis ◽  
Hepatic Stellate Cells ◽  
In Vitro Study ◽  
Stellate Cells ◽  
Protective Role ◽  
Activating Transcription Factor 3 ◽  
Dependent Manner ◽  
Liver Fibrogenesis

AbstractThe excessive accumulation of extracellular matrix (ECM) is a key feature of liver fibrosis and the activated hepatic stellate cells (HSCs) are the major producer of ECM proteins. However, the precise mechanisms and target molecules that are involved in liver fibrosis remain unclear. In this study, we reported that activating transcription factor 3 (ATF3) was over-expressed in mice and human fibrotic livers, in activated HSCs and injured hepatocytes (HCs). Both in vivo and in vitro study have revealed that silencing ATF3 reduced the expression of pro-fibrotic genes and inhibited the activation of HSCs, thus alleviating the extent of liver fibrosis, indicating a potential protective role of ATF3 knockdown. However, ATF3 was not involved in either the apoptosis or proliferation of HCs. In addition, our data illustrated that increased nuclear localization of ATF3 promoted the transcription of fibrogenic genes and lnc-SCARNA10, which functioned as a novel positive regulator of TGF-β signaling in liver fibrogenesis by recruiting SMAD3 to the promoter of these genes. Interestingly, further study also demonstrated that lnc-SCARNA10 promoted the expression of ATF3 in a TGF-β/SMAD3-dependent manner, revealing a TGF-β/ATF3/lnc-SCARNA10 axis that contributed to liver fibrosis by activating HSCs. Taken together, our data provide a molecular mechanism implicating induced ATF3 in liver fibrosis, suggesting that ATF3 may represent a useful target in the development of therapeutic strategies for liver fibrosis.

scholarly journals Albumin inhibits the nuclear translocation of Smad3 via interleukin-1beta signaling in hepatic stellate cells

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ji Hoon Park ◽  
Janghyun Kim ◽  
So-Young Choi ◽  
Boram Lee ◽  
Jung-Eun Lee ◽  
...  
Keyword(s):  
Retinoic Acid ◽  
Liver Fibrosis ◽  
Hepatic Stellate Cells ◽  
Transforming Growth Factor ◽  
Nuclear Translocation ◽  
Stellate Cells ◽  
Retinol Binding Protein ◽  
Drug Candidate ◽  
Dependent Manner ◽  
Interleukin 1Beta

AbstractActivation of quiescent hepatic stellate cells (HSCs) to myofibroblasts plays a key role in liver fibrosis. We had previously shown that albumin and its derivative, R-III (a retinol-binding protein—albumin domain III fusion protein), inhibited HSC activation by sequestering retinoic acid (RA) and that R-III administration reduced carbon tetrachloride (CCl4)-induced liver fibrosis. In this study, we aimed to elucidate the mechanism of action of albumin downstream of RA sequestration. Nuclear factor-κB p65 was evenly distributed in the cytoplasm in activated mouse HSCs, whereas albumin expression or R-III treatment (albumin/R-III) caused the nuclear translocation of p65, probably via RA sequestration, resulting in a dramatic increase in interleukin-1beta (IL-1β) expression. Albumin/R-III in turn induced the phosphorylation of Smad3 at the linker region, inhibiting its nuclear import in an IL-1β-dependent manner. Consistent with the in vitro results, the level of IL-1β mRNA expression was higher in CCl4/R-III-treated livers than in CCl4-treated livers. These findings reveal that albumin/R-III inhibits the transforming growth factor-β-Smad3 signaling as well as the retinoic acid receptor-mediated pathway, which probably contributes to the inhibition of HSC activation, and suggest that R-III may be an anti-fibrotic drug candidate.

scholarly journals Fuzheng Huayu Recipe Ameliorates Liver Fibrosis by Restoring Balance between Epithelial-to-Mesenchymal Transition and Mesenchymal-to-Epithelial Transition in Hepatic Stellate Cells

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Qin Pan ◽  
Yu-Qin Wang ◽  
Guang-Ming Li ◽  
Xiao-Yan Duan ◽  
Jian-Gao Fan
Keyword(s):  
Liver Fibrosis ◽  
P38 Mapk ◽  
Hepatic Stellate Cells ◽  
Epithelial To Mesenchymal Transition ◽  
Stellate Cells ◽  
Cordyceps Sinensis ◽  
Dependent Manner ◽  
Radix Salviae Miltiorrhizae ◽  
Mesenchymal Transition ◽  
Mesenchymal To Epithelial Transition

Activation of hepatic stellate cells (HSCs) depending on epithelial-to-mesenchymal transition (EMT) reflects the key event of liver fibrosis. Contrastively, mesenchymal-to-epithelial transition (MET) of HSCs facilitates the fibrosis resolution. Here we investigated the effect of Fuzheng Huayu (FZHY) recipe, a Chinese herbal decoction made ofRadix Salviae Miltiorrhizae,Semen Persicae,Cordyceps sinensis,Pollen Pini, andGynostemma pentaphyllum, on liver fibrosis concerning the balance of EMT and MET in HSCs. In contrast to the increased TGF-β1/BMP-7 ratio in activated HSCs, FZHY administration induced significant upregulation of BMP-7 and downregulation of TGF-β1at both transcription and translation levels. Restoration of TGF-β1/BMP-7 ratio inhibited the expression of p38 MAPK and phosphorylated p38 MAPK, resulting in the reversal of epithelial-to-mesenchymal transition (EMT) to mesenchymal-to-epithelial transition (MET) as characterized by the abolishment of EMT markers (α-SMA and desmin) and reoccurrence of MET marker (E-cadherin).In vivotreatment of FZHY recipe also demonstrated the statistical reduction of activated HSCs with EMT phenotype, which attenuated the carbon tetrachloride- (CCl4-) induced liver fibrosis in a dose-dependent manner. These findings may highlight a novel antifibrotic role of FZHY recipe on the basis of rebalancing EMT and MET in HSCs.

scholarly journals CD8+ tissue-resident memory T cells promote liver fibrosis resolution by inducing apoptosis of hepatic stellate cells

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yuzo Koda ◽  
Toshiaki Teratani ◽  
Po-Sung Chu ◽  
Yuya Hagihara ◽  
Yohei Mikami ◽  
...  
Keyword(s):  
Liver Fibrosis ◽  
Hepatic Stellate Cells ◽  
Molecular Mechanisms ◽  
Stellate Cells ◽  
Dependent Manner ◽  
Resolution Model ◽  
Cell Transcriptome ◽  
Single Cell Transcriptome ◽  
Resident Memory T Cells

AbstractNon-alcoholic steatohepatitis (NASH) is a leading cause of chronic liver disease that can progress to liver fibrosis. Recent clinical advance suggests a reversibility of liver fibrosis, but the cellular and molecular mechanisms underlying NASH resolution remain unclarified. Here, using a murine diet-induced NASH and the subsequent resolution model, we demonstrate direct roles of CD8+ tissue-resident memory CD8+ T (CD8+ Trm) cells in resolving liver fibrosis. Single-cell transcriptome analysis and FACS analysis revealed CD69+CD103−CD8+ Trm cell enrichment in NASH resolution livers. The reduction of liver CD8+ Trm cells, maintained by tissue IL-15, significantly delayed fibrosis resolution, while adoptive transfer of these cells protected mice from fibrosis progression. During resolution, CD8+ Trm cells attracted hepatic stellate cells (HSCs) in a CCR5-dependent manner, and predisposed activated HSCs to FasL-Fas-mediated apoptosis. Histological assessment of patients with NASH revealed CD69+CD8+ Trm abundance in fibrotic areas, further supporting their roles in humans. These results highlight the undefined role of liver CD8+ Trm in fibrosis resolution.

scholarly journals Non-Invasively Distinguishing Progress of Liver Fibrosis by Visualizing Hepatic Platelet Derived Growth Factor Receptor-Beta Expression with an MRI Modality in Mice

2020 ◽  
Author(s):  
Ling Wu ◽  
Xiao-quan Huang ◽  
Na Li ◽  
Cao Xie ◽  
Sheng-xiang Rao ◽  
...  
Keyword(s):  
Growth Factor ◽  
Liver Fibrosis ◽  
Hepatic Fibrosis ◽  
Hepatic Stellate Cells ◽  
Cyclic Peptides ◽  
Growth Factor Receptor ◽  
Stellate Cells ◽  
Platelet Derived Growth Factor ◽  
Dependent Manner ◽  
Activated Hepatic Stellate Cells

Abstract Background: Activated hepatic stellate cells are the most critical cell responsible for liver fibrosis. In liver fibrogenesis, platelet-derived growth factor is the most prominent mitogen for hepatic stellate cells. This study aims to explore the potential of gadolinium (Gd)-labeled cyclic peptides (pPB) targeted to platelet-derived growth factor receptor-β (PDGFR-β) as a magnetic resonance imaging (MRI) radiotracer to identify the progress of liver fibrosis by imaging hepatic PDGFR-β expression. Results: Hepatic PDGFR-β expression level was found to be paralleled with the severity of liver fibrosis, which was increased with the progression of fibrosis and reduced with the regression. Majority of cells expressing PDGFR-β was determined to be activated hepatic stellate cells in fibrotic livers. Culture-activated human hepatic stellate cells expressed abundant PDGFR-β, and FITC-labeled pPB could bind to human hepatic stellate cells in a concentration and time dependent manner. With Gd-labeled pPB as a tracer, an MRI modality demonstrated that the relative hepatic T1-weighed MR signal value was increased progressively along with severity of hepatic fibrosis and reduced with the remission. Conclusion: Hepatic PDGFR-β expression reflects the progress of hepatic fibrosis, and MR imaging using Gd-labeled pPB as a tracer may distinguish different stages of liver fibrosis in mice.

iRhom2 inhibits bile duct obstruction–induced liver fibrosis

2019 ◽  
Vol 12 (605) ◽  
pp. eaax1194 ◽  
Author(s):  
Balamurugan Sundaram ◽  
Kristina Behnke ◽  
Andrea Belancic ◽  
Mazin A. Al-Salihi ◽  
Yasser Thabet ◽  
...  
Keyword(s):  
Bile Duct ◽  
Liver Fibrosis ◽  
Hepatic Stellate Cells ◽  
Stellate Cells ◽  
Duct Ligation ◽  
Tnf Α ◽  
Primary Mouse ◽  
Factor Α

Chronic liver disease can induce prolonged activation of hepatic stellate cells, which may result in liver fibrosis. Inactive rhomboid protein 2 (iRhom2) is required for the maturation of A disintegrin and metalloprotease 17 (ADAM17, also called TACE), which is responsible for the cleavage of membrane-bound tumor necrosis factor–α (TNF-α) and its receptors (TNFRs). Here, using the murine bile duct ligation (BDL) model, we showed that the abundance of iRhom2 and activation of ADAM17 increased during liver fibrosis. Consistent with this, concentrations of ADAM17 substrates were increased in plasma samples from mice after BDL and in patients suffering from liver cirrhosis. We observed increased liver fibrosis, accelerated disease progression, and an increase in activated stellate cells after BDL in mice lacking iRhom2 (Rhbdf2−/−) compared to that in controls. In vitro primary mouse hepatic stellate cells exhibited iRhom2-dependent shedding of the ADAM17 substrates TNFR1 and TNFR2. In vivo TNFR shedding after BDL also depended on iRhom2. Treatment of Rhbdf2−/− mice with the TNF-α inhibitor etanercept reduced the presence of activated stellate cells and alleviated liver fibrosis after BDL. Together, these data suggest that iRhom2-mediated inhibition of TNFR signaling protects against liver fibrosis.

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