PPARgamma activation by antidiabetic thiazolidinediones reduces liver fibrosis and hepatic stellate cells activation in vivo

2001 ◽  
Vol 34 ◽  
pp. 92
Author(s):  
A. Galli ◽  
G. Svegliati-Baroni ◽  
T. Mello ◽  
R. Salzano ◽  
E. Ceni ◽  
...  
2020 ◽  
Vol 11 (12) ◽  
Author(s):  
Zhemin Shi ◽  
Kun Zhang ◽  
Ting Chen ◽  
Yu Zhang ◽  
Xiaoxiao Du ◽  
...  

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.


2014 ◽  
pp. n/a-n/a ◽  
Author(s):  
Chun-xiao Pan ◽  
Fan-rong Wu ◽  
Xiao-yu Wang ◽  
Jie Tang ◽  
Wen-fan Gao ◽  
...  

2020 ◽  
Vol 20 (1) ◽  
pp. 25-37
Author(s):  
Haleigh B. Eubanks ◽  
Elise G. Lavoie ◽  
Jessica Goree ◽  
Jeffrey A. Kamykowski ◽  
Neriman Gokden ◽  
...  

Hepatic stellate cells (HSC) are critical effector cells of liver fibrosis. In the injured liver, HSC differentiate into a myofibrobastic phenotype. A critical feature distinguishing myofibroblastic from quiescent HSC is cytoskeletal reorganization. Soluble NSF attachment receptor (SNARE) proteins are important in trafficking of newly synthesized proteins to the plasma membrane for release into the extracellular environment. The goals of this project were to determine the expression of specific SNARE proteins in myofibroblastic HSC and to test whether their alteration changed the HSC phenotype in vitro and progression of liver fibrosis in vivo. We found that HSC lack the t-SNARE protein, SNAP-25, but express a homologous protein, SNAP-23. Downregulation of SNAP-23 in HSC induced reduction in polymerization and disorganization of the actin cytoskeleton associated with loss of cell movement. In contrast, reduction in SNAP-23 in mice by monogenic deletion delayed but did not prevent progression of liver fibrosis to cirrhosis. Taken together, these findings suggest that SNAP-23 is an important regular of actin dynamics in myofibroblastic HSC, but that the role of SNAP-23 in the progression of liver fibrosis in vivo is unclear.


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Qi Wang ◽  
Song Wei ◽  
Lei Li ◽  
Qingfa Bu ◽  
Haoming Zhou ◽  
...  

AbstractLiver fibrosis is a patho-physiological process which can develop into cirrhosis, and hepatic carcinoma without intervention. Our study extensively investigated the mechanisms of lncRNA NEAT1 and miR-139-5p in regulating liver fibrosis progression. Our results demonstrated that the expression of lncRNA NEAT1 was increased and the expression of miR-139-5p was decreased in fibrotic liver tissues. LncRNA NEAT1 could sponge miR-139-5p and promoted hepatic stellate cells (HSCs) activation by directly inhibiting the expression of miR-139-5p. The co-localization of lncRNA NEAT1 with miR-139-5p was shown in the cytosols of activated HSCs. miR-139-5p upregulation could suppress the expression of β-catenin. The overexpression of β-catenin promoted HSCs activation. Moreover, we found that β-catenin could interact with SOX9 promoted HSCs activation. Our further studies demonstrated that SOX9 could bind with the TGF-β1 promoter and promoted the transcription activity of TGF-β1. The upregulation of TGF-β1 further promoted HSCs activation. In vivo study also suggested that lncRNA NEAT1 knockdown and miR-139-5p overexpression alleviated murine liver fibrosis. LncRNA NEAT1 exacerbated liver fibrosis by suppressing the expression of miR-139-5p. Collectively, our study suggested that miR-139-5p sponged by lncRNA NEAT1 regulated liver fibrosis via targeting β-catenin/SOX9/TGF-β1 Pathway.


2021 ◽  
Vol 22 (24) ◽  
pp. 13354
Author(s):  
Seita Kataoka ◽  
Atsushi Umemura ◽  
Keiichiro Okuda ◽  
Hiroyoshi Taketani ◽  
Yuya Seko ◽  
...  

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.


Cells ◽  
2019 ◽  
Vol 8 (5) ◽  
pp. 503 ◽  
Author(s):  
Oliver Krenkel ◽  
Jana Hundertmark ◽  
Thomas Ritz ◽  
Ralf Weiskirchen ◽  
Frank Tacke

Activation of hepatic stellate cells (HSCs) and their trans-differentiation towards collagen-secreting myofibroblasts (MFB) promote liver fibrosis progression. During chronic liver disease, resting HSCs become activated by inflammatory and injury signals. However, HSCs/MFB not only produce collagen, but also secrete cytokines, participate in metabolism, and have biomechanical properties. We herein aimed to characterize the heterogeneity of these liver mesenchymal cells by single cell RNA sequencing. In vivo resting HSCs or activated MFB were isolated from C57BL6/J mice challenged by carbon tetrachloride (CCl4) intraperitoneally for 3 weeks to induce liver fibrosis and compared to in vitro cultivated MFB. While resting HSCs formed a homogenous population characterized by high platelet derived growth factor receptor β (PDGFRβ) expression, in vivo and in vitro activated MFB split into heterogeneous populations, characterized by α-smooth muscle actin (α-SMA), collagens, or immunological markers. S100 calcium binding protein A6 (S100A6) was a universal marker of activated MFB on both the gene and protein expression level. Compared to the heterogeneity of in vivo MFB, MFB in vitro sequentially and only transiently expressed marker genes, such as chemokines, during culture activation. Taken together, our data demonstrate the heterogeneity of HSCs and MFB, indicating the existence of functionally relevant subsets in hepatic fibrosis.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Injoo Hwang ◽  
Eun Ju Lee ◽  
Hyomin Park ◽  
Dodam Moon ◽  
Hyo-Soo Kim

Abstract Background Hepatic stellate cells (HSCs) are activated in response to liver injury with TIF1γ-suppression, leading to liver fibrosis. Here, we examined the mechanism how reduction of TIF1γ in HSCs induces damage on hepatocytes and liver fibrosis. Method Lrat:Cas9-ERT2:sgTif1γ mice were treated Tamoxifen (TMX) or wild-type mice were treated Thioacetamide (TAA). HSCs were isolated from mice liver and analyzed role of Tif1γ. HepG2 were treated retinol with/without siRNA for Stimulated by retinoic acid 6 (STRA6) or Retinoic acid receptor(RAR)-antagonist, and LX2 were treated siTIF1γ and/or siSTRA6. TAA treated mice were used for evaluation of siSTRA6 effect in liver fibrosis. Results When we blocked the Tif1γ in HSCs using Lrat:Cas9-ERT2:sgTif1γ mice, retinol is distributed into hepatocytes. Retinol influx was confirmed using HepG2, and the increased intracellular retinol led to the upregulation of lipogenesis-related-genes and triglyceride. This effect was inhibited by a RAR-antagonist or knock-down of STRA6. In the LX2, TIF1γ-suppression resulted in upregulation of STRA6 and retinol release, which was inhibited by STRA6 knock-down. The role of STRA6-mediated retinol transfer from HSCs to hepatocytes in liver fibrosis was demonstrated by in vivo experiments where blocking of STRA6 reduced fibrosis. Conclusions Retinol from HSCs via STRA6 in response to injury with TIF1γ-reduction is taken up by hepatocytes via STRA6, leading to fat-deposition and damage, and liver fibrosis.


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