scholarly journals PU.1-deficient mice are resistant to thioacetamide-induced hepatic fibrosis: PU.1 finely regulates Sirt1 expression via transcriptional promotion of miR-34a and miR-29c in hepatic stellate cells

2017 ◽  
Vol 37 (6) ◽  
Author(s):  
Qing Liu ◽  
Yongming Zhang ◽  
Songzhu Yang ◽  
Yanfang Wu ◽  
Jiantao Wang ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Liver Fibrosis ◽  
Inflammatory Response ◽  
Hepatic Fibrosis ◽  
Hepatic Stellate Cells ◽  
Stellate Cells ◽  
Wild Type ◽  
Promoter Regions ◽  
Protein Levels ◽  
Deficient Mice

PU box binding protein (PU.1) is a critical transcription factor involved in many pathological processes. However, its exact role in activation of hepatic stellate cells (HSCs) and liver fibrosis was rarely reported. Here, we found that, in HSCs of PU.1+/− mice, Sirt1 mRNA expression was not changed but Sirt1 protein was significantly increased, suggesting its promoting role in Sirt1 translation. We then isolated HSCs from wild-type (WT) and PU.1+/− mice, and the pcDNA-PU.1 expression vector was transfected into PU.1+/− HSCs. We checked the levels of miR-34a and miR-29c, two Sirt1-targetting miRNAs, and protein levels of PU.1 and Sirt1. The results showed that miR-34a/-29c were significantly reduced and Sirt1 protein was increased in PU.1+/− HSCs, compared with WT HSCs. Besides, PU.1 overexpression inversed the reduction in miR-34a/-29c levels and the increase in Sirt1 protein in both PU.1+/- HSCs and WT HSCs. Additionally, ChIP-quantitive real-time PCR (qPCR) assay comfirmed that PU.1 was directly bound to both the promoter regions of miR-34a and miR-29c. Importantly, PU.1 overexpression promoted the proliferation, migration, activation, oxidative stress and inflammatory response in WT HSCs, while the promotion could be inversed by either overexpression of Sirt1 or inhibition of miR-34a/-29c. Moreover, animal model of liver fibrosis was established by intraperitoneal injections of thioacetamide (TAA) in WT and PU.1+/− mice, respectively. Compared with the WT mice, PU.1+/− mice displayed a lower fibrotic score, less collagen content, better liver function, and lower levels of oxidative stress and inflammatory response. In conclusion, PU.1 suppresses Sirt1 translation via transcriptional promotion of miR-34a/-29c, thus promoting Sirt1-mediated HSC activation and TAA-induced hepatic fibrosis.

scholarly journals Fas/FasL mediates NF-κBp65/PUMA-modulated hepatocytes apoptosis via autophagy to drive liver fibrosis

2021 ◽  
Vol 12 (5) ◽  
Author(s):  
Siwei Tan ◽  
Xianzhi Liu ◽  
Lingjun Chen ◽  
Xiaoqin Wu ◽  
Li Tao ◽  
...  
Keyword(s):  
Liver Fibrosis ◽  
Inflammatory Response ◽  
Mouse Models ◽  
Hepatic Stellate Cells ◽  
Fas Ligand ◽  
Stellate Cells ◽  
Wild Type ◽  
Potential Therapeutic Target ◽  
Hepatic Diseases ◽  
Liver Fibrogenesis

AbstractFas/Fas ligand (FasL)-mediated cell apoptosis involves a variety of physiological and pathological processes including chronic hepatic diseases, and hepatocytes apoptosis contributes to the development of liver fibrosis following various causes. However, the mechanism of the Fas/FasL signaling and hepatocytes apoptosis in liver fibrogenesis remains unclear. The Fas/FasL signaling and hepatocytes apoptosis in liver samples from both human sections and mouse models were investigated. NF-κBp65 wild-type mice (p65f/f), hepatocytes specific NF-κBp65 deletion mice (p65Δhepa), p53-upregulated modulator of apoptosis (PUMA) wild-type (PUMA-WT) and PUMA knockout (PUMA-KO) littermate models, and primary hepatic stellate cells (HSCs) were also used. The mechanism underlying Fas/FasL-regulated hepatocytes apoptosis to drive HSCs activation in fibrosis was further analyzed. We found Fas/FasL promoted PUMA-mediated hepatocytes apoptosis via regulating autophagy signaling and NF-κBp65 phosphorylation, while inhibition of autophagy or PUMA deficiency attenuated Fas/FasL-modulated hepatocytes apoptosis and liver fibrosis. Furthermore, NF-κBp65 in hepatocytes repressed PUMA-mediated hepatocytes apoptosis via regulating the Bcl-2 family, while NF-κBp65 deficiency in hepatocytes promoted PUMA-mediated hepatocytes apoptosis and enhanced apoptosis-linked inflammatory response, which contributed to the activation of HSCs and liver fibrogenesis. These results suggest that Fas/FasL contributes to NF-κBp65/PUMA-modulated hepatocytes apoptosis via autophagy to enhance liver fibrogenesis, and this network could be a potential therapeutic target for liver fibrosis.

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.

Fluorofenidone attenuates hepatic fibrosis by suppressing the proliferation and activation of hepatic stellate cells

2014 ◽  
Vol 306 (3) ◽  
pp. G253-G263 ◽  
Author(s):  
Yu Peng ◽  
Huixiang Yang ◽  
Nasui Wang ◽  
Yan Ouyang ◽  
Yanrong Yi ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Liver Fibrosis ◽  
Western Blot ◽  
Hepatic Fibrosis ◽  
Hepatic Stellate Cells ◽  
Cyclin E ◽  
Stellate Cells ◽  
Collagen I ◽  
Phase Cell ◽  
Cyclin D

Fluorofenidone (AKF-PD) is a novel pyridone agent. The purpose of this study is to investigate the inhibitory effects of AKF-PD on liver fibrosis in rats and the involved molecular mechanism related to hepatic stellate cells (HSCs). Rats treated with dimethylnitrosamine or CCl4 were randomly divided into normal, model, AKF-PD treatment, and pirfenidone (PFD) treatment groups. The isolated primary rat HSCs were treated with AKF-PD and PFD respectively. Cell proliferation and cell cycle distribution were analyzed by bromodeoxyuridine and flow cytometry, respectively. The expression of collagen I and α-smooth muscle actin (α-SMA) were determined by Western blot, immunohistochemical staining, and real-time RT-PCR. The expression of cyclin D1, cyclin E, and p27kip1 and phosphorylation of MEK, ERK, Akt, and 70-kDa ribosomal S6 kinase (p70S6K) were detected by Western blot. AKF-PD significantly inhibited PDGF-BB-induced HSC proliferation and activation by attenuating the expression of collagen I and α-SMA, causing G0/G1 phase cell cycle arrest, reducing expression of cyclin D1 and cyclin E, and promoting expression of p27kip1. AKF-PD also downregulated PDGF-BB-induced MEK, ERK, Akt, and p70S6K phosphorylation in HSCs. In rat liver fibrosis, AKF-PD alleviated hepatic fibrosis by decreasing necroinflammatory score and semiquantitative score, and reducing expression of collagen I and α-SMA. AKF-PD attenuated the progression of hepatic fibrosis by suppressing HSCs proliferation and activation via the ERK/MAPK and PI3K/Akt signaling pathways. AKF-PD may be used as a potential novel therapeutic agent against liver fibrosis.

scholarly journals Inhibition of Mastermind-like 1 alleviates liver fibrosis induced by carbon tetrachloride in rats

2018 ◽  
Vol 243 (14) ◽  
pp. 1099-1108
Author(s):  
Shaoping Zheng ◽  
Yixiong Chen ◽  
Shaojiang Zheng ◽  
Zhihui He ◽  
Zhihong Weng
Keyword(s):  
Carbon Tetrachloride ◽  
Liver Fibrosis ◽  
Hepatic Fibrosis ◽  
Hepatic Stellate Cells ◽  
Stellate Cells ◽  
Underlying Mechanism ◽  
Signal Pathways ◽  
Fibrotic Liver ◽  
Hepatic Fibrogenesis ◽  
Signal Transductions

Mastermind-like 1 (MAML1) functions in critical transcriptional coactivation in Notch and Wnt/β-catenin signal pathways, which participate in hepatic fibrosis. This study is aimed to reveal the potential role of MAML1 in liver fibrosis and identify its underlying mechanism. In present research, the enhanced expression of MAML1 was found in the fibrotic liver tissues in carbon tetrachloride (CCl4)-induced hepatic fibrosis in rats, and MAML1 expression increased gradually during the activation of hepatic stellate cells (HSCs) isolated from the normal rat. Further studies showed that blocking MAML1 expression efficiently decreased the expression of α-SMA and collagen I (Col1a1) in HSCs. Interestingly, MAML1 may modulate HSCs activation via interrupting both Notch and Wnt/β-catenin signal transductions, and the inhibition of MAML1 by a recombinant adeno-associated virus type 1 vector carrying shRNA targeting MAML1 alleviated CCl4-induced hepatic fibrosis in rats. These findings suggest that the selective regulation of MAML1 expression may be a feasible therapeutic approach to reverse liver fibrosis. Impact statement Liver fibrosis is a common wound-healing response to all kinds of liver injuries. Hepatic stellate cells (HSCs) activation is the key event during liver fibrogenesis. Thus, the elucidation of mechanisms for regulating HSCs activation is helpful for identifying novel anti-fibrotic targets and strategies. MAML1, an important component of Notch signal, functions in critical transcriptional coactivation in the Notch and Wnt/β-catenin signal pathways. In the present study, we investigated the potential function of MAML1 during hepatic fibrogenesis in rats. Our results demonstrated that MAML1 participates in liver fibrosis through modulating HSCs activation via interrupting both the Notch and Wnt/β-catenin signal transductions. Additionally, the inhibition of MAML1 markedly attenuated CCl4-induced hepatic fibrogenesis in rats. Our results shed a light for the exploitation of a new therapeutic strategy for hepatic fibrosis via targeting MAML1.

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 Plumbagin Ameliorates CCl4-Induced Hepatic Fibrosis in Rats via the Epidermal Growth Factor Receptor Signaling Pathway

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Si Chen ◽  
Yi Chen ◽  
Bi Chen ◽  
Yi-jing Cai ◽  
Zhuo-lin Zou ◽  
...  
Keyword(s):  
Growth Factor ◽  
Liver Fibrosis ◽  
Epidermal Growth Factor ◽  
Hepatic Fibrosis ◽  
Hepatic Stellate Cells ◽  
Growth Factor Receptor ◽  
Stellate Cells ◽  
Heparin Binding ◽  
Fibrotic Liver ◽  
Epidermal Growth

Epidermal growth factor (EGF) and its signaling molecules, EGFreceptor (EGFR) and signal transducer and activator of transcription factor 3 (STAT3), have been considered to play a role in liver fibrosis and cirrhosis. Plumbagin (PL) is an extracted component from the plant and has been used to treat different kinds of cancer. However, its role in regulation of EGFR and STAT3 during liver fibrosis has not been investigated. In this study, the effects of PL on the regulation of EGFR and STAT3 were investigated in carbon tetrachloride (CCl4) induced liver fibrosis and hepatic stellate cells (HSC-T6). PL significantly attenuated liver injury and fibrosis in CCl4treated rats. At concentrations of 2 to 6 μM, PL did not induce significant cytotoxicity of HSC-T6 cells. Moreover, PL reduced phosphorylation of EGFR and STAT3 in both fibrotic liver and heparin-binding EGF-like growth factor (HB-EGF) treated HSC-T6 cells. Furthermore, PL reduced the expression ofα-SMA, EGFR, and STAT3 in both fibrotic liver and HB-EGF treated HSC-T6 cells. In conclusion, plumbagin could ameliorate the development of hepatic fibrosis through its downregulation of EGFR and STAT3 in the liver, especially in hepatic stellate cells.

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 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.

scholarly journals Honokiol Acts as a Potent Anti-Fibrotic Agent in the Liver through Inhibition of TGF-β1/SMAD Signaling and Autophagy in Hepatic Stellate Cells

2021 ◽  
Vol 22 (24) ◽  
pp. 13354
Author(s):  
Seita Kataoka ◽  
Atsushi Umemura ◽  
Keiichiro Okuda ◽  
Hiroyoshi Taketani ◽  
Yuya Seko ◽  
...  
Keyword(s):  
Liver Fibrosis ◽  
Signaling Pathway ◽  
Hepatic Fibrosis ◽  
Hepatic Stellate Cells ◽  
Stellate Cells ◽  
Smad Signaling ◽  
Smad Signaling Pathway ◽  
Tgf Β1

Chronic liver injury may result in hepatic fibrosis, which can progress to cirrhosis and eventually liver failure. There are no drugs that are specifically approved for treating hepatic fibrosis. The natural product honokiol (HNK), a bioactive compound extracted from Magnolia grandiflora, represents a potential tool in the management of hepatic fibrosis. Though HNK has been reported to exhibit suppressive effects in a rat fibrosis model, the mechanisms accounting for this suppression remain unclear. In the present study, the anti-fibrotic effects of HNK on the liver were evaluated in vivo and in vitro. In vivo studies utilized a murine liver fibrosis model, in which fibrosis is induced by treatment with carbon tetrachloride (CCl4). For in vitro studies, LX-2 human hepatic stellate cells (HSCs) were treated with HNK, and expression of markers of fibrosis, cell viability, the transforming growth factor-β (TGF-β1)/SMAD signaling pathway, and autophagy were analyzed. HNK was well tolerated and significantly attenuated CCl4-induced liver fibrosis in vivo. Moreover, HNK decreased HSC activation and collagen expression by downregulating the TGF-β1/SMAD signaling pathway and autophagy. These results suggest that HNK is a new potential candidate for the treatment of hepatic fibrosis through suppressing both TGF-β1/SMAD signaling and autophagy in HSCs.

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