Snail1 transcription factor is a critical mediator of hepatic stellate cell activation following hepatic injury

2011 ◽  
Vol 300 (2) ◽  
pp. G316-G326 ◽  
Author(s):  
Melania Scarpa ◽  
Alessia R. Grillo ◽  
Paola Brun ◽  
Veronica Macchi ◽  
Annalisa Stefani ◽  
...  
Keyword(s):  
Wound Healing ◽  
Transcription Factor ◽  
Liver Fibrosis ◽  
Liver Injury ◽  
Mrna Expression ◽  
Hepatic Stellate Cell ◽  
Stellate Cell ◽  
Qrt Pcr

Following liver injury, the wound-healing process is characterized by hepatic stellate cell (HSC) activation from the quiescent fat-storing phenotype to a highly proliferative myofibroblast-like phenotype. Snail1 is a transcription factor best known for its ability to trigger epithelial-mesenchymal transition, to influence mesoderm formation during embryonic development, and to favor cell survival. In this study, we evaluated the expression of Snail1 in experimental and human liver fibrosis and analyzed its role in the HSC transdifferentiation process. Liver samples from patients with liver fibrosis and from mice treated by either carbon tetrachloride (CCl4) or thioacetamide (TAA) were evaluated for mRNA expression of Snail1. The transcription factor expression was investigated by immunostaining and real-time quantitative RT-PCR (qRT-PCR) on in vitro and in vivo activated murine HSC. Snail1 knockdown studies on cultured HSC and on CCl4-treated mice were performed by adenoviral delivery of short-hairpin RNA; activation-related genes were quantitated by real-time qRT-PCR and Western blotting. Snail1 mRNA expression resulted upregulated in murine experimental models of liver injury and in human hepatic fibrosis. In vitro studies showed that Snail1 is expressed by HSC and that its transcription is augmented in in vitro and in vivo activated HSC compared with quiescent HSC. At the protein level, we could observe the nuclear translocation of Snail1 in activated HSC. Snail1 knockdown resulted in the downregulation of activation-related genes both in vitro and in vivo. Our data support a role for Snail1 transcription factor in the hepatic wound-healing response and its involvement in the HSC transdifferentiation process.

Rapamycin inhibits hepatic stellate cell proliferation in vitro and limits fibrogenesis in an in vivo model of liver fibrosis

1999 ◽  
Vol 117 (5) ◽  
pp. 1198-1204 ◽  
Author(s):  
Jianliang Zhu ◽  
Jian Wu ◽  
Edward Frizell ◽  
Shu-Ling Liu ◽  
Reza Bashey ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Liver Fibrosis ◽  
Hepatic Stellate Cell ◽  
Stellate Cell ◽  
In Vivo Model ◽  
Proliferation In Vitro

scholarly journals Epiregulin (EREG) and Myocardin Related Transcription Factor A (MRTF-A) Form a Feedforward Loop to Drive Hepatic Stellate Cell Activation

2021 ◽  
Vol 8 ◽  
Author(s):  
Xiaoyan Wu ◽  
Wenhui Dong ◽  
Tianyi Zhang ◽  
Haozhen Ren ◽  
Jinglin Wang ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Liver Fibrosis ◽  
Cell Activation ◽  
Serum Response Factor ◽  
Stellate Cell ◽  
Feedforward Loop ◽  
Related Transcription Factor ◽  
Egf Family

Trans-differentiation of quiescent hepatic stellate cells (HSC) into myofibroblast cells is considered the linchpin of liver fibrosis. A myriad of signaling pathways contribute to HSC activation and consequently liver fibrosis. Epidermal growth factor (EGF) family of cytokines signal through the cognate receptor EGFR to promote HSC activation. In the present study we investigated the transcription regulation of epiregulin (EREG), an EGFR ligand, during HSC activation. We report that EREG expression was significantly up-regulated in activated HSCs compared to quiescent HSCs isolated from mice. In addition, there was an elevation of EREG expression in HSCs undergoing activation in vitro. Of interest, deficiency of myocardin-related transcription factor A (MRTF-A), a well-documented regulator of HSC trans-differentiation, attenuated up-regulation of EREG expression both in vivo and in vitro. Further analysis revealed that MRTF-A interacted with serum response factor (SRF) to bind directly to the EREG promoter and activate EREG transcription. EREG treatment promoted HSC activation in vitro, which was blocked by MRTF-A depletion or inhibition. Mechanistically, EREG stimulated nuclear trans-location of MRTF-A in HSCs. Together, our data portray an EREG-MRTF-A feedforward loop that contributes to HSC activation and suggest that targeting the EREG-MRTF-A axis may yield therapeutic solutions against liver fibrosis.

scholarly journals Resolvin D1 attenuates CCl4 Induced Liver Fibrosis by Inhibiting Autophagy-Mediated HSC activation via AKT/mTOR Pathway

2021 ◽  
Vol 12 ◽  
Author(s):  
Jiahuan Li ◽  
Xiaoling Deng ◽  
Shuhan Wang ◽  
Qianqian Jiang ◽  
Keshu Xu
Keyword(s):  
Liver Fibrosis ◽  
Liver Injury ◽  
Hepatic Fibrosis ◽  
Stellate Cell ◽  
Mtor Pathway ◽  
Protective Effects ◽  
Resolvin D1 ◽  
Akt Inhibitor

Resolvin D1 (RvD1) was previously reported to relieve inflammation and liver damage in several liver diseases, but its potential role in liver fibrosis remains elusive. The aim of our study was to investigate the effects and underlying mechanisms of RvD1 in hepatic autophagy in liver fibrosis. In vivo, male C57BL/6 mice were intraperitoneally injected with 20% carbon tetrachloride (CCl4, 5 ml/kg) twice weekly for 6 weeks to establish liver fibrosis model. RvD1 (100 ng or 300 ng/mouse) was added daily in the last 2 weeks of the modeling period. In vitro, lipopolysaccharide (LPS)-activated LX-2 cells were co-treated with increasing concentrations (2.5–10 nM) of RvD1. The degree of liver injury was measured by detecting serum AST and ALT contents and H&E staining. Hepatic fibrosis was assessed by masson's trichrome staining and metavir scoring. The qRT-PCR, western blot, immunohistochemistry, and immunofluorescence were applied to liver tissues or LPS-activated LX-2 cells to explore the protective effects of RvD1 in liver fibrosis. Our findings reported that RvD1 significantly attenuated CCl4 induced liver injury and fibrosis by decreasing plasma AST and ALT levels, reducing collagen I and α-SMA accumulation and other pro-fibrotic genes (CTGF, TIMP-1 and Vimentin) expressions in mouse liver, restoring damaged histological architecture and improving hepatic fibrosis scores. In vitro, RvD1 also repressed the LPS induced LX-2 cells activation and proliferation. These significant improvements mainly attributed to the inhibiting effect of RvD1 on autophagy in the process of hepatic stellate cell (HSC) activation, as demonstrated by decreased ratio of LC3-II/I and elevated p62 after RvD1 treatment. In addition, using AZD5363 (an AKT inhibitor that activates autophagy) and AZD8055 (an mTOR inhibitor, another autophagy activator), we further verified that RvD1 suppressed autophagy-mediated HSC activation and alleviated CCl4 induced liver fibrosis partly through AKT/mTOR pathway. Overall, these results demonstrate that RvD1 treatment is expected to become a novel therapeutic strategy against liver fibrosis.

scholarly journals Regulation of in vitro and in vivo Hepatic Stellate Cell Activation by the Ayrl Hydrocarbon Receptor

2020 ◽  
Author(s):  
Shivakumar Rayavara Veerabhadraiah
Keyword(s):  
Liver Fibrosis ◽  
Liver Injury ◽  
Cell Activation ◽  
Stellate Cell ◽  
Pathological Condition ◽  
Matrix Material ◽  
Subsequent Development ◽  
Type I

Liver fibrosis is a pathological condition characterized by the excessive deposition of extracellular matrix material by activated hepatic stellate cells (HSCs). We recently reported that activation of the aryl hydrocarbon receptor (AhR), a ligand-activated transcription factor, with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) increases HSC activation in vitro and in mouse models of experimental liver fibrosis. The goal of this project was to determine the mechanism by which AhR activation impacts HSC activation and the subsequent development of liver fibrosis. It is possible that HSCs are direct cellular targets for TCDD. Alternatively, TCDD could increase HSC activation indirectly by exacerbating hepatocyte damage and inflammation. To investigate this, we generated mice in which the AhR was selectively removed from either hepatocytes or HSCs to determine the ramifications on liver injury, inflammation, and HSC activation in an experimental model of liver fibrosis elicited by chronic administration of TCDD. Results from these studies indicate that TCDD does not directly activate HSCs in the mouse liver to produce fibrosis. Instead, it appears that TCDD-induced changes in hepatocytes, such as the development of steatosis, are what ultimately stimulate HSC activation and produce fibrosis. A second focus of this project was to investigate an endogenous role for AhR signaling in the regulation of HSC activation in the absence of liver injury and inflammation. To this end, I used CRISPR/Cas9 technology to knock down the AhR in the human HSC cell line, LX-2. I discovered that a functional AhR is required for optimal proliferation of activated HSCs. However, other endpoints of HSC activation, such as the production of collagen type I, were not impacted by the removal of AhR signaling. These findings are important because the AhR has been shown to be a druggable target, and there is growing interest in therapeutically modulating AhR activity to prevent or reverse HSC activation. Collectively, results from this project indicate that therapeutically targeting AhR signaling in hepatocytes, instead of AhR signaling in HSCs, might be a preferred approach for limiting HSC activation and preventing or diminishing liver fibrosis.

scholarly journals Leucine-rich Repeats and Immunoglobulin 1 (LRIG1) Ameliorates Liver Fibrosis and Hepatic Stellate Cell Activation via Inhibiting Sphingosine Kinase 1 (SphK1)/Sphingosine-1-Phosphate (S1P) Pathway

2020 ◽  
Author(s):  
Wei Zhan ◽  
Xin Liao ◽  
Zhongsheng Chen ◽  
Lianghe Li ◽  
Tian Tian ◽  
...  
Keyword(s):  
Liver Fibrosis ◽  
Hepatic Stellate Cell ◽  
Stellate Cell ◽  
Sphingosine Kinase ◽  
Sphingosine Kinase 1 ◽  
Sphingosine 1 Phosphate ◽  
Leucine Rich Repeats ◽  
Tgf Β1

To detect the leucine-rich repeats and immunoglobulin 1 (LRIG1) ameliorated liver fibrosis and hepatic stellate cell (HSC) activation via inhibiting sphingosine kinase 1 (SphK1)/Sphingosine-1-Phosphate (S1P) pathway. C57BL/6 male mice (eight weeks old) were intraperitoneal injection with 10% carbon tetrachloride (CCl4) as an in vivo model. The LX-2 cells were induced as amodel for in vitro study by TGF-β (10 ng/mL). The Hematoxylin-eosin (HE) staining, Masson staining, and Sirius red staining results showed that CCl4 caused serious fibrosis and injury in liver tissue, high expression of type I collagen α1 chain (Col1α1) and α-smooth muscle actin (α-SMA) in liver tissue, while the LRIG1 expression level was significantly decreased in LX-2 cell lines. The LRIG1 ameliorated CCl4-induced liver fibrosis, indicated by the fibronectin, α-SMA, LRIG1, SphK1, Col1α1, fibrin Connexin 1 (Fn1), tissue inhibitor of metalloproteinase-1 (TIMP1), sphingosine-1-phosphate (S1P), transforming growth factor-beta 1 (TGF-β1) expression level changes. Similar results were observed in TGF-β1 treated of LX-2 cells. However, the effects were attenuated by treatment with LRIG1. Moreover, SphK1 inhibitors abrogated the effect of LRIG1 on fibrosis. These results demonstrated that LRIG1 improved liver fibrosis in vitro and in vivo via suppressing the SphK1/S1P pathway, indicating its potential use in the treatment of liver fibrosis.

Inhibition of the Na+/H+ exchanger reduces rat hepatic stellate cell activity and liver fibrosis: An in vitro and in vivo study

2001 ◽  
Vol 120 (2) ◽  
pp. 545-556 ◽  
Author(s):  
Antonio Benedetti ◽  
Antonio Di Sario ◽  
Alessandro Casini ◽  
Francesco Ridolfi ◽  
Emanuele Bendia ◽  
...  
Keyword(s):  
Liver Fibrosis ◽  
Hepatic Stellate Cell ◽  
Stellate Cell ◽  
Cell Activity ◽  
In Vivo Study

Healing effects of curcumin nanoparticles in deep tissue injury mouse model.

2020 ◽  
Vol 18 ◽  
Author(s):  
Zirui Zhang ◽  
Shangcong Han ◽  
Panpan Liu ◽  
Xu Yang ◽  
Jing Han ◽  
...  
Keyword(s):  
Wound Healing ◽  
Mrna Expression ◽  
Tissue Injury ◽  
Inflammatory Cells ◽  
Pcr Analysis ◽  
Protective Effects ◽  
Deep Tissue ◽  
Deep Tissue Injury

Background: Chronic inflammation and lack of angiogenesis are the important pathological mechanisms in deep tissue injury (DTI). Curcumin is a well-known anti-inflammatory and antioxidant agent. However, curcumin is unstable under acidic and alkaline conditions, and can be rapidly metabolized and excreted in the bile, which shortens its bioactivity and efficacy. Objective: This study aimed to prepare curcumin-loaded poly (lactic-co-glycolic acid) nanoparticles (CPNPs) and to elucidate the protective effects and underlying mechanisms of wound healing in DTI models. Methods: CPNPs were evaluated for particle size, biocompatibility, in vitro drug release and their effect on in vivo wound healing. Results : The results of in vivo wound closure analysis revealed that CPNP treatments significantly improved wound contraction rates (p<0.01) at a faster rate than other three treatment groups. H&E staining revealed that CPNP treatments resulted in complete epithelialization and thick granulation tissue formation, whereas control groups resulted in a lack of compact epithelialization and persistence of inflammatory cells within the wound sites. Quantitative real-time PCR analysis showed that treatment with CPNPs suppressed IL-6 and TNF-α mRNA expression, and up-regulated TGF-β, VEGF-A and IL-10 mRNA expression. Western blot analysis showed up-regulated protein expression of TGF-β, VEGF-A and phosphorylatedSTAT3. Conclusion: Our results showed that CPNPs enhanced wound healing in DTI models, through modulation of the JAK2/STAT3 signalling pathway and subsequent upregulation of pro-healing factors.

Targeting ER protein TXNDC5 in hepatic stellate cell mitigates liver fibrosis by repressing non-canonical TGFβ signalling

Gut ◽  
2021 ◽  
pp. gutjnl-2021-325065
Author(s):  
Chen-Ting Hung ◽  
Tung-Hung Su ◽  
Yen-Ting Chen ◽  
Yueh-Feng Wu ◽  
You-Tzung Chen ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Liver Fibrosis ◽  
Liver Injury ◽  
Transforming Growth Factor ◽  
Stellate Cell ◽  
Transforming Growth Factor Β1 ◽  
Duct Ligation ◽  
Extracellular Matrix Production ◽  
Matrix Production

Background and objectivesLiver fibrosis (LF) occurs following chronic liver injuries. Currently, there is no effective therapy for LF. Recently, we identified thioredoxin domain containing 5 (TXNDC5), an ER protein disulfide isomerase (PDI), as a critical mediator of cardiac and lung fibrosis. We aimed to determine if TXNDC5 also contributes to LF and its potential as a therapeutic target for LF.DesignHistological and transcriptome analyses on human cirrhotic livers were performed. Col1a1-GFPTg, Alb-Cre;Rosa26-tdTomato and Tie2-Cre/ERT2;Rosa26-tdTomato mice were used to determine the cell type(s) where TXNDC5 was induced following liver injury. In vitro investigations were conducted in human hepatic stellate cells (HSCs). Col1a2-Cre/ERT2;Txndc5fl/fl (Txndc5cKO) and Alb-Cre;Txndc5fl/fl (Txndc5Hep-cKO) mice were generated to delete TXNDC5 in HSCs and hepatocytes, respectively. Carbon tetrachloride treatment and bile duct ligation surgery were employed to induce liver injury/fibrosis in mice. The extent of LF was quantified using histological, imaging and biochemical analyses.ResultsTXNDC5 was upregulated markedly in human and mouse fibrotic livers, particularly in activated HSC at the fibrotic foci. TXNDC5 was induced by transforming growth factor β1 (TGFβ1) in HSCs and it was both required and sufficient for the activation, proliferation, survival and extracellular matrix production of HSC. Mechanistically, TGFβ1 induces TXNDC5 expression through increased ER stress and ATF6-mediated transcriptional regulation. In addition, TXNDC5 promotes LF by redox-dependent JNK and signal transducer and activator of transcription 3 activation in HSCs through its PDI activity, activating HSCs and making them resistant to apoptosis. HSC-specific deletion of Txndc5 reverted established LF in mice.ConclusionsER protein TXNDC5 promotes LF through redox-dependent HSC activation, proliferation and excessive extracellular matrix production. Targeting TXNDC5, therefore, could be a potential novel therapeutic strategy to ameliorate LF.

Stiffness is associated with hepatic stellate cell heterogeneity during liver fibrosis

2021 ◽  
Author(s):  
Enis Kostallari ◽  
Bo Wei ◽  
Delphine Sicard ◽  
Jiahui Li ◽  
Shawna A. Cooper ◽  
...  
Keyword(s):  
Liver Fibrosis ◽  
Focal Adhesion ◽  
Hepatic Stellate Cell ◽  
Stellate Cell ◽  
Liver Stiffness ◽  
Specific Protein ◽  
Cellular Level ◽  
Fibrotic Liver ◽  
Soft Matrix

The fibrogenic wound-healing response in liver increases stiffness. Stiffness mechano-transduction in turn amplifies fibrogenesis. Here, we aimed to understand the distribution of stiffness in fibrotic liver, how it impacts hepatic stellate cell (HSC) heterogeneity and identify mechanisms by which stiffness amplifies fibrogenic responses. Magnetic resonance elastography and atomic force microscopy demonstrated a heterogenous distribution of liver stiffness at macroscopic and microscopic levels, respectively, in a carbon tetrachloride (CCl4) mouse model of liver fibrosis as compared to controls. High stiffness was mainly attributed to extracellular matrix dense areas. To identify a stiffness-sensitive HSC sub-population, we performed scRNA-seq on primary HSCs derived from healthy versus CCl4-treated mice. A sub-cluster of HSCs was matrix-associated with the most upregulated pathway in this sub-population being focal adhesion signaling, including a specific protein termed four and a half LIM domains protein 2 (FHL2). In vitro, FHL2 expression was increased in primary human HSCs cultured on stiff matrix as compared to HSCs on soft matrix. Moreover, FHL2 knockdown inhibited fibronectin and collagen 1 expression, whereas its overexpression promoted matrix production. In summary, we demonstrate stiffness heterogeneity at the whole organ, lobular, and cellular level which drives an amplification loop of fibrogenesis through specific focal adhesion molecular pathways.

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