c‐Jun acts downstream of PI3K / AKT signaling to mediate the effect of leptin on methionine adenosyltransferase 2B in hepatic stellate cells in vitro and in vivo

2020 ◽  
Vol 252 (4) ◽  
pp. 423-432
Author(s):  
Xiaofei Zhu ◽  
Xin Jia ◽  
Fangyun Cheng ◽  
Haimeng Tian ◽  
Yajun Zhou
2007 ◽  
Vol 12 (5) ◽  
pp. 059801
Author(s):  
Aiguo Shen ◽  
Zhangxiu Liao ◽  
Hui Wang ◽  
Iiho Goan ◽  
Yong Wu ◽  
...  

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.


Drug Research ◽  
2017 ◽  
Vol 68 (03) ◽  
pp. 153-158 ◽  
Author(s):  
Rahmaniah Rahmaniah ◽  
Yuyuntia Yuyuntia ◽  
Vivian Soetikno ◽  
Wawaimuli Arozal ◽  
Radiana Antarianto ◽  
...  

Abstract Background Alpha mangostin has been reported to have activity for the treatment of liver fibrosis in the rats. However, the mechanisms of action are poorly understood. This study was aimed to investigate the effect of alpha mangostin on hepatic stellate cells (HSC) activation and proliferation through TGF-β/Smad and Akt signaling pathways. Methods Immortalized HSC, LX2 cells, were incubated with TGF-β with or without alpha mangostin (5 or 10 μM). Sorafenib 10 µM was used as positive control. LX2 viability was counted using trypan blue exclusion method. The effect of alpha mangostin on TGF-β concentrations, and the expressions of proliferation and fibrogenic markers were evaluated. Results Alpha mangostin treatment resulted in a reduced proliferation of HSC, decreased Ki-67 and p-Akt expressions. These findings were followed with decreased concentrations of TGF-β in the medium of cells treated with alpha mangostin, decreased expressions of COL1A1, TIMP1, PAI1, α-SMA, and p-Smad3 as fibrogenic markers. These effects were shown to be dose-dependent. Conclusions Alpha mangostin inhibits hepatic stellate cells proliferation and activation through TGF-β/Smad and Akt signaling pathways in dose dependent manner.


2013 ◽  
Vol 58 ◽  
pp. S59-S60
Author(s):  
F.J. Cubero ◽  
G. Zhao ◽  
M. Hatting ◽  
Y.A. Nevzorova ◽  
F. Schaefer ◽  
...  

2007 ◽  
Vol 12 (3) ◽  
pp. 034003 ◽  
Author(s):  
Aiguo Shen ◽  
Zhangxiu Liao ◽  
Hui Wang ◽  
Iiho Goan ◽  
Yong Wu ◽  
...  

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

2003 ◽  
Vol 285 (3) ◽  
pp. G652-G660 ◽  
Author(s):  
H. Hendrickson ◽  
S. Chatterjee ◽  
S. Cao ◽  
M. Morales Ruiz ◽  
W. C. Sessa ◽  
...  

Diminished endothelial nitric oxide (NO) synthase (eNOS)-derived NO production from the hepatic vascular endothelium contributes to hepatic vasoconstriction in portal hypertension. The aim of this study was to examine the mechanism of this process by testing the influence of a constitutively active form of eNOS (S1179DeNOS) in both primary and propagated liver cells in vitro and in the sham and bile duct ligated (BDL) rat liver in vivo, using an adenoviral vector encoding green fluorescent protein (AdGFP) and S1179DeNOS (AdS1179DeNOS). AdS1179DeNOS transduction augmented basal and agonist-stimulated NO generation in nonparenchymal liver cells. Sham rats transduced in vivo with AdS1179DeNOS evidenced a decreased pressor response to incremental doses of the vasoconstrictor methoxamine compared with sham rats transduced with AdGFP. However, BDL rats transduced with AdS1179DeNOS did not display improved vasodilatory responses as evidenced by similar flow-dependent pressure increases to that observed in BDL rats transduced with AdGFP, despite similar levels of viral transgene expression. We next examined the influence of the eNOS inhibitory protein caveolin on S1179DeNOS dysfunction in cirrhotic liver. Immunogold electron microscopic analysis of caveolin in BDL liver demonstrated prominent expression not only in liver endothelial cells, but also in hepatic stellate cells. In vitro studies in the LX2 hepatic stellate cell line demonstrate that caveolin precipitates recombinant S1179DeNOS in LX2 cells, that recombinant S1179DeNOS coprecipitates caveolin, and that binding is enhanced in the presence of overexpression of caveolin. Furthermore, caveolin overexpression inhibits recombinant S1179DeNOS activity. These studies indicate that recombinant S1179DeNOS protein functions appropriately in normal liver cells and tissue but evidences dysfunction in the cirrhotic rat liver and that caveolin expression and inhibition in BDL nonparenchymal cells, including hepatic stellate cells, may account for this dysfunction.


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.


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