scholarly journals PPARγ Antagonizes Hypoxia-Induced Activation of Hepatic Stellate Cell through Cross Mediating PI3K/AKT and cGMP/PKG Signaling

PPAR Research ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Qinghui Zhang ◽  
Shihao Xiang ◽  
Qingqian Liu ◽  
Tao Gu ◽  
Yongliang Yao ◽  
...  
Keyword(s):  
Hepatic Fibrosis ◽  
Hepatic Stellate Cells ◽  
Stellate Cell ◽  
Stellate Cells ◽  
Inhibitory Effect ◽  
Akt Signaling ◽  
Unique Role ◽  
Hypoxic Environment ◽  
Sirius Red

Background and Aims. Accumulating evidence reveals that PPARγ plays a unique role in the regulation of hepatic fibrosis and hepatic stellate cells (HSCs) activation. This study was aimed at investigating the role of PPARγ in hypoxia-induced hepatic fibrogenesis and its possible mechanism. Methods. Rats used for CCl4-induced hepatic fibrosis model were exposed to hypoxia for 8 hours each day. Rats exposed to hypoxia were treated with or without the PPARγ agonist rosiglitazone. Liver sections were stained with HE and Sirius red staining 8 weeks later. HSCs were exposed to hypoxic environment in the presence or absence of rosiglitazone, and expression of PPARγ and two fibrosis markers, α-SMA and desmin, were measured using western blot and immunofluorescence staining. Next, levels of PPARγ, α-SMA, and desmin as well as PKG and cGMP activity were detected using PI3K/AKT and a cGMP activator or inhibitor. Results. Hypoxia promoted the induction and progress of hepatic fibrosis and HSCs activation. Meanwhile, rosiglitazone significantly antagonized the effects induced by hypoxia. Signaling by sGC/cGMP/PKG promoted the inhibitory effect of PPARγ on hypoxia-induced activation of HSCs. Moreover, PI3K/AKT signaling or PDE5 blocked the above response of PPARγ. Conclusion. sGC/cGMP/PKG and PI3K/AKT signals act on PPARγ synergistically to attenuate hypoxia-induced HSC activation.

scholarly journals Inhibitory effect of oestradiol on activation of rat hepatic stellate cells in vivo and in vitro

Gut ◽  
1999 ◽  
Vol 44 (1) ◽  
pp. 127-136 ◽  
Author(s):  
I Shimizu ◽  
Y Mizobuchi ◽  
M Yasuda ◽  
M Shiba ◽  
Y-R Ma ◽  
...  
Keyword(s):  
Hepatic Fibrosis ◽  
Hepatic Stellate Cells ◽  
Stellate Cell ◽  
Stellate Cells ◽  
Inhibitory Effect ◽  
Type I ◽  
Mrna Levels ◽  
Pig Serum

BackgroundHepatic stellate cells play a key role in the pathogenesis of hepatic fibrosis.AimsTo examine the inhibitory effect of oestradiol on stellate cell activation.MethodsIn vivo, hepatic fibrosis was induced in rats by dimethylnitrosamine or pig serum. In vitro, rat stellate cells were activated by contact with plastic dishes resulting in their transformation into myofibroblast-like cells.ResultsIn the dimethylnitrosamine and pig serum models, treatment with oestradiol at gestation related doses resulted in a dose dependent suppression of hepatic fibrosis with restored content of hepatic retinyl palmitate, reduced collagen content, lower areas of stellate cells which express α smooth muscle actin (α-SMA) and desmin, and lower procollagen type I and III mRNA levels in the liver. In cultured stellate cells, oestradiol inhibited type I collagen production, α-SMA expression, and cell proliferation. These findings suggest that oestradiol is a potent inhibitor of stellate cell transformation.ConclusionThe antifibrogenic role of oestradiol in the liver may contribute to the sex associated differences in the progression from hepatic fibrosis to cirrhosis.

scholarly journals Mapping glycan-mediated galectin-3 interactions by live cell proximity labeling

2020 ◽  
Author(s):  
Eugene Joeh ◽  
Timothy O’Leary ◽  
Weichao Li ◽  
Richard Hawkins ◽  
Jonathan R. Hung ◽  
...  
Keyword(s):  
Hepatic Fibrosis ◽  
Hepatic Stellate Cells ◽  
Cell Activation ◽  
Weak Interactions ◽  
Stellate Cell ◽  
Three Dimensional ◽  
Stellate Cells ◽  
Living Cells ◽  
Live Cells ◽  
Galectin 3

AbstractGalectin-3 is a glycan-binding protein (GBP) that binds β-galactoside glycan structures to orchestrate a variety of important biological events, including the activation of hepatic stellate cells to cause hepatic fibrosis. While the requisite glycan epitopes needed to bind galectin-3 have long been elucidated, the cellular glycoproteins that bear these glycan signatures remain unknown. Given the importance of the three-dimensional arrangement of glycans in dictating GBP interactions, strategies that allow the identification of GBP receptors in live cells, where the native glycan presentation and glycoprotein expression are preserved, possess significant advantages over static and artificial systems. Here, we describe the integration of a proximity labeling method and quantitative mass spectrometry to map the glycan and glycoprotein interactors for galectin-3 in live hepatic stellate cells. Understanding the identity of the glycoproteins and defining the structures of the glycans required for galectin-3 mediated hepatic stellate cell activation will empower efforts to design and develop selective therapeutics to mitigate hepatic fibrosis.SignificanceBecause of the weak interactions between individual glycan-binding proteins (GBP), such as galectin-3, and glycans, strategies that allow the direct interrogation of these interactions in living cells remain limited. Thus, the glycan and glycoprotein ligands that are physiologically relevant for galectin-3 binding are insufficiently described. Here, we used a proximity labeling approach that catalytically tags interactors for galectin-3 and identified its pertinent glycan and glycoprotein counter-receptors in live hepatic stellate cells. This study demonstrates that proximity labeling is a powerful tool for mapping GBP complexes in living cells, and when coupled with chemical inhibitors, it can discriminate between protein-protein and protein-glycan interactions.Graphical Abstract

scholarly journals Role of cytoglobin, a novel radical scavenger, in stellate cell activation and hepatic fibrosis

2020 ◽  
Vol 26 (3) ◽  
pp. 280-293 ◽  
Author(s):  
Le Thi Thanh Thuy ◽  
Hoang Hai ◽  
Norifumi Kawada
Keyword(s):  
Liver Fibrosis ◽  
Hepatic Fibrosis ◽  
Cell Activation ◽  
Stellate Cell ◽  
Stellate Cells ◽  
Radical Scavenger ◽  
History Of Research ◽  
Duct Ligation ◽  
History Of

Cytoglobin (Cygb), a stellate cell-specific globin, has recently drawn attention due to its association with liver fibrosis. In the livers of both humans and rodents, Cygb is expressed only in stellate cells and can be utilized as a marker to distinguish stellate cells from hepatic fibroblast-derived myofibroblasts. Loss of Cygb accelerates liver fibrosis and cancer development in mouse models of chronic liver injury including diethylnitrosamine-induced hepatocellular carcinoma, bile duct ligation-induced cholestasis, thioacetamide-induced hepatic fibrosis, and choline-deficient L-amino acid-defined diet-induced non-alcoholic steatohepatitis. This review focuses on the history of research into the role of reactive oxygen species and nitrogen species in liver fibrosis and discusses the current perception of Cygb as a novel radical scavenger with an emphasis on its role in hepatic stellate cell activation and fibrosis.

scholarly journals Inhibition of SIRT2 suppresses hepatic fibrosis

2016 ◽  
Vol 310 (11) ◽  
pp. G1155-G1168 ◽  
Author(s):  
Maribel Arteaga ◽  
Na Shang ◽  
Xianzhong Ding ◽  
Sherri Yong ◽  
Scott J. Cotler ◽  
...  
Keyword(s):  
Gene Expression ◽  
Liver Fibrosis ◽  
Hepatic Fibrosis ◽  
Hepatic Stellate Cells ◽  
Histone Deacetylases ◽  
Critical Role ◽  
Stellate Cells ◽  
Novel Strategy ◽  
Underlying Mechanisms

Liver fibrosis can progress to cirrhosis and result in serious complications of liver disease. The pathogenesis of liver fibrosis involves the activation of hepatic stellate cells (HSCs), the underlying mechanisms of which are not fully known. Emerging evidence suggests that the classic histone deacetylases play a role in liver fibrosis, but the role of another subfamily of histone deacetylases, the sirtuins, in the development of hepatic fibrosis remains unknown. In this study, we found that blocking the activity of sirtuin 2 (SIRT2) by using inhibitors or shRNAs significantly suppressed fibrogenic gene expression in HSCs. We further demonstrated that inhibition of SIRT2 results in the degradation of c-MYC, which is important for HSC activation. In addition, we discovered that inhibition of SIRT2 suppresses the phosphorylation of ERK, which is critical for the stabilization of c-MYC. Moreover, we found that Sirt2 deficiency attenuates the hepatic fibrosis induced by carbon tetrachloride (CCl4) and thioacetamide (TAA). Furthermore, we showed that SIRT2, p-ERK, and c-MYC proteins are all overexpressed in human hepatic fibrotic tissues. These data suggest a critical role for the SIRT2/ERK/c-MYC axis in promoting hepatic fibrogenesis. Inhibition of the SIRT2/ERK/c-MYC axis represents a novel strategy to prevent and to potentially treat liver fibrosis and cirrhosis.

scholarly journals Curdione and Schisandrin C Synergistically Reverse Hepatic Fibrosis via Modulating the TGF-β Pathway and Inhibiting Oxidative Stress

2021 ◽  
Vol 9 ◽  
Author(s):  
Wenzhang Dai ◽  
Qin Qin ◽  
Zhiyong Li ◽  
Li Lin ◽  
Ruisheng Li ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Chinese Medicine ◽  
Hepatic Fibrosis ◽  
Hepatic Stellate Cells ◽  
Cell Activation ◽  
Stellate Cell ◽  
Stellate Cells ◽  
Great Promise ◽  
Potential Candidate ◽  
Active Components

Hepatic fibrosis is the final pathway of several chronic liver diseases, which is characterized by the accumulation of extracellular matrix due to chronic hepatocyte damage. Activation of hepatic stellate cells and oxidative stress (OS) play an important role in mediating liver damage and initiating hepatic fibrosis. Hence, hepatic fibrosis can be reversed by inhibiting multiple channels such as oxidative stress, liver cell damage, or activation of hepatic stellate cells. Liuwei Wuling Tablets is a traditional Chinese medicine formula with the effect of anti- hepatic fibrosis, but the composition and mechanism of reversing hepatic fibrosis are still unclear. Our study demonstrated that one of the main active components of the Chinese medicine Schisandra chinensis, schisandrin C (Sin C), significantly inhibited oxidative stress and prevented hepatocyte injury. Meanwhile one of the main active components of the Chinese medicine Curdione inhibited hepatic stellate cell activation by targeting the TGF-β1/Smads signaling pathway. The further in vivo experiments showed that Sin C, Curdione and the combination of both have the effect of reversing liver fibrosis in mice, and the combined effect of inhibiting hepatic fibrosis is superior to treatment with Sin C or Curdione alone. Our study provides a potential candidate for multi-molecular or multi-pathway combination therapies for the treatment of hepatic fibrosis and demonstrates that combined pharmacotherapy holds great promise in the prevention and treatment of hepatic fibrosis.

scholarly journals Role of G Protein-Coupled Receptors in Hepatic Stellate Cells and Approaches to Anti-Fibrotic Treatment of Non-Alcoholic Fatty Liver Disease

2021 ◽  
Vol 12 ◽  
Author(s):  
Takefumi Kimura ◽  
Simran Singh ◽  
Naoki Tanaka ◽  
Takeji Umemura
Keyword(s):  
Liver Disease ◽  
Hepatic Fibrosis ◽  
Hepatic Stellate Cells ◽  
Fatty Liver Disease ◽  
Stellate Cells ◽  
G Protein Coupled Receptors ◽  
Alcoholic Fatty Liver ◽  
G Protein Coupled ◽  
Alcoholic Fatty Liver Disease

The prevalence of non-alcoholic fatty liver disease (NAFLD) is globally increasing. Gaining control over disease-related events in non-alcoholic steatohepatitis (NASH), an advanced form of NAFLD, is currently an unmet medical need. Hepatic fibrosis is a critical prognostic factor in NAFLD/NASH. Therefore, a better understanding of the pathophysiology of hepatic fibrosis and the development of related therapies are of great importance. G protein-coupled receptors (GPCRs) are cell surface receptors that mediate the function of a great variety of extracellular ligands. GPCRs represent major drug targets, as indicated by the fact that about 40% of all drugs currently used in clinical practice mediate their therapeutic effects by acting on GPCRs. Like many other organs, various GPCRs play a role in regulating liver function. It is predicted that more than 50 GPCRs are expressed in the liver. However, our knowledge of how GPCRs regulate liver metabolism and fibrosis in the different cell types of the liver is very limited. In particular, a better understanding of the role of GPCRs in hepatic stellate cells (HSCs), the primary cells that regulate liver fibrosis, may lead to the development of drugs that can improve hepatic fibrosis in NAFLD/NASH. In this review, we describe the functions of multiple GPCRs expressed in HSCs, their roles in liver fibrogenesis, and finally speculate on the development of novel treatments for NAFLD/NASH.

scholarly journals Involvement of Rho/Rho kinase pathway in regulation of apoptosis in rat hepatic stellate cells

2003 ◽  
Vol 285 (5) ◽  
pp. G880-G886 ◽  
Author(s):  
Hitoshi Ikeda ◽  
Kayo Nagashima ◽  
Mikio Yanase ◽  
Tomoaki Tomiya ◽  
Masahiro Arai ◽  
...  
Keyword(s):  
Dna Fragmentation ◽  
Hepatic Fibrosis ◽  
Lysophosphatidic Acid ◽  
Hepatic Stellate Cells ◽  
Therapeutic Strategy ◽  
Caspase 3 ◽  
Rho Kinase ◽  
Stellate Cells ◽  
Kinase Pathway

Hepatic stellate cells (HSCs) play a central role in the development of hepatic fibrosis. Recent evidence has revealed that HSCs also play a role in its resolution, where HSC apoptosis was determined. Moreover, induction of HSC apoptosis caused a reduction of experimental hepatic fibrosis in rats. Thus knowing the mechanism of HSC apoptosis might be important to clarify the pathophysiology and establish the therapeutic strategy for hepatic fibrosis. In HSCs, Rho and Rho kinase are known to regulate contraction, migration, and proliferation with modulation of cell morphology. Controversy exists as to the participation of Rho and Rho kinase on cell survival, and little is known regarding this matter in HSCs. In this study, we directed our focus on the role of the Rho pathway in the regulation of HSC survival. C3, an inhibitor of Rho, increased histone-associated DNA fragmentation and caspase 3 activity with enhanced condensation of nuclear chromatin in rat cultured HSCs. Moreover, Y-27632, an inhibitor of Rho kinase, had the same effects, suggesting that inhibition of the Rho/Rho kinase pathway causes HSC apoptosis. On the other hand, lysophosphatidic acid, which stimulates the Rho/Rho kinase pathway, decreased histone-associated DNA fragmentation in HSCs. Inhibition of the Rho/Rho kinase pathway did not affect p53, Bcl-2, or Bax levels in HSCs. Thus we concluded that the Rho/Rho kinase pathway may play a role in the regulation of HSC survival.

scholarly journals Inhibitory Effect of a Human MicroRNA, miR-6133-5p, on the Fibrotic Activity of Hepatic Stellate Cells in Culture

2020 ◽  
Vol 21 (19) ◽  
pp. 7251
Author(s):  
Susumu Hamada-Tsutsumi ◽  
Masaya Onishi ◽  
Kentaro Matsuura ◽  
Masanori Isogawa ◽  
Keigo Kawashima ◽  
...  
Keyword(s):  
Growth Factor ◽  
Transforming Growth Factor Beta ◽  
Hepatic Stellate Cells ◽  
Target Genes ◽  
Transforming Growth Factor ◽  
Stellate Cell ◽  
Growth Factor Receptor ◽  
Stellate Cells ◽  
Inhibitory Effect ◽  
Phosphorylated Akt

Background: We recently identified 39 human microRNAs, which effectively suppress hepatitis B virus (HBV) replication in hepatocytes. Chronic HBV infection often results in active, hepatitis-related liver fibrosis; hence, we assessed whether any of these microRNAs have anti-fibrotic potential and predicted that miR-6133-5p may target several fibrosis-related genes. Methods: The hepatic stellate cell line LX-2 was transfected with an miR-6133-5p mimic and subsequently treated with Transforming growth factor (TGF)-β. The mRNA and protein products of the COL1A1 gene, encoding collagen, and the ACTA2 gene, an activation marker of hepatic stellate cells, were quantified. Results: The expression of COL1A1 and ACTA2 was markedly reduced in LX-2 cells treated with miR-6133-5p. Interestingly, phosphorylation of c-Jun N-terminal kinase (JNK) was also significantly decreased by miR-6133-5p treatment. The expression of several predicted target genes of miR-6133-5p, including TGFBR2 (which encodes Transforming Growth Factor Beta Receptor 2) and FGFR1 (which encodes Fibroblast Growth Factor Receptor 1), was also reduced in miR-6133-5p-treated cells. The knockdown of TGFBR2 by the corresponding small interfering RNA greatly suppressed the expression of COL1A1 and ACTA2. Treatment with the JNK inhibitor, SP600125, also suppressed COL1A1 and ACTA2 expression, indicating that TGFBR2 and JNK mediate the anti-fibrotic effect of miR-6133-5p. The downregulation of FGFR1 may result in a decrease of phosphorylated Akt, ERK (extracellular signal-regulated kinase), and JNK. Conclusion: miR-6133-5p has a strong anti-fibrotic effect, mediated by inactivation of TGFBR2, Akt, and JNK.

Role of microRNAs in Hepatic Stellate Cells and Hepatic Fibrosis: an Update

2020 ◽  
Vol 26 ◽  
Author(s):  
Sai Zhu ◽  
Xin Chen ◽  
Yu Chen ◽  
Xiao-Feng Li ◽  
Si-Yu Chen ◽  
...  
Keyword(s):  
Hepatic Fibrosis ◽  
Hepatic Stellate Cells ◽  
Stellate Cells ◽  
Pathological Process ◽  
Untranslated Regions ◽  
Rna Molecules ◽  
Non Coding Rna ◽  
Major Cell Type ◽  
Novel Biomarkers

: MicroRNAs (miRNAs) are small non-coding RNA molecules that regulate the expression of targets genes by binding to the 3′-untranslated regions. They play vital roles in diverse biological processes, including the development of hepatic fibrosis (HF). HF is characterized by the accumulation of extracellular matrix (ECM) and hepatic stellate cells (HSCs) are considered a major cell type for producing ECM. Alteration of the HSC phenotype plays a crucial role in the HF pathological process. miRNAs involved in various biological process, such as differentiation, apoptosis, migration, and their relevant signaling pathways, are expressed in HSCs; however, emerging evidence indicates that numerous miRNAs are abnormally expressed in activated HSCs. In this review, we summarize the categorization of miRNAs in HF and describe the relationships among them. We also discuss miRNAs recently discovered to be related to HF, and attempt to find potential miRNAs that may serve as novel biomarkers for use in HF treatment.

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