scholarly journals HBeAg mediates inflammatory functions of macrophages by TLR2 contributing to hepatic fibrosis

BMC Medicine ◽  
2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Xiaoyu Xie ◽  
Huanran Lv ◽  
Chenxi Liu ◽  
Xiaonan Su ◽  
Zhen Yu ◽  
...  
Keyword(s):  
Signaling Pathway ◽  
Hepatic Fibrosis ◽  
Hepatic Stellate Cells ◽  
Macrophage Activation ◽  
Stellate Cells ◽  
Mapk Signaling ◽  
Functional Domain ◽  
Dependent Manner ◽  
Core Domain ◽  
Direct Binding

Abstract Background We and others have confirmed activation of macrophages plays a critical role in liver injury and fibrogenesis during HBV infection. And we have also proved HBeAg can obviously induce the production of macrophage inflammatory cytokines compared with HBsAg and HBcAg. However, the receptor and functional domain of HBeAg in macrophage activation and its effects and mechanisms on hepatic fibrosis remain elusive. Methods The potentially direct binding receptors of HBeAg were screened and verified by Co-IP assay. Meanwhile, the function domain and accessible peptides of HBeAg for macrophage activation were analyzed by prediction of surface accessible peptide, construction, and synthesis of truncated fragments. Furthermore, effects and mechanisms of the activation of hepatic stellate cells induced by HBeAg-treated macrophages were investigated by Transwell, CCK-8, Gel contraction assay, Phospho Explorer antibody microarray, and Luminex assay. Finally, the effect of HBeAg in hepatic inflammation and fibrosis was evaluated in both human and murine tissues by immunohistochemistry, immunofluorescence, ELISA, and detection of liver enzymes. Results Herein, we verified TLR-2 was the direct binding receptor of HBeAg. Meanwhile, C-terminal peptide (122-143 aa.) of core domain in HBeAg was critical for macrophage activation. But arginine-rich domain of HBcAg hided this function, although HBcAg and HBeAg shared the same core domain. Furthermore, HBeAg promoted the proliferation, motility, and contraction of hepatic stellate cells (HSCs) in a macrophage-dependent manner, but not alone. PI3K-AKT-mTOR and p38 MAPK signaling pathway were responsible for motility phenotype of HSCs, while the Smad-dependent TGF-β signaling pathway for proliferation and contraction of them. Additionally, multiple chemokines and cytokines, such as CCL2, CCL5, CXCL10, and TNF-α, might be key mediators of HSC activation. Consistently, HBeAg induced transient inflammation response and promoted early fibrogenesis via TLR-2 in mice. Finally, clinical investigations suggested that the level of HBeAg is associated with inflammation and fibrosis degrees in patients infected with HBV. Conclusions HBeAg activated macrophages via the TLR-2/NF-κB signal pathway and further exacerbated hepatic fibrosis by facilitating motility, proliferation, and contraction of HSCs with the help of macrophages.

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.

scholarly journals Babao Dan attenuates hepatic fibrosis by inhibiting hepatic stellate cells activation and proliferation via TLR4 signaling pathway

Oncotarget ◽  
2016 ◽  
Vol 7 (50) ◽  
pp. 82554-82566 ◽  
Author(s):  
Lei Liang ◽  
Xue Yang ◽  
Yang Yu ◽  
Xiaoyong Li ◽  
Yechen Wu ◽  
...  
Keyword(s):  
Signaling Pathway ◽  
Hepatic Fibrosis ◽  
Hepatic Stellate Cells ◽  
Stellate Cells ◽  
Tlr4 Signaling ◽  
Tlr4 Signaling Pathway

scholarly journals Transcriptional repression of SIRT1 by protein inhibitor of activated STAT 4 (PIAS4) in hepatic stellate cells contributes to liver fibrosis

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Lina Sun ◽  
Zhiwen Fan ◽  
Junliang Chen ◽  
Wenfang Tian ◽  
Min Li ◽  
...  
Keyword(s):  
Liver Fibrosis ◽  
Hepatic Stellate Cells ◽  
High Glucose ◽  
Interstitial Fibrosis ◽  
Stellate Cells ◽  
Quiescent State ◽  
Dependent Manner ◽  
Gene Promoters ◽  
Sirt1 Expression ◽  
Primary Mouse

Abstract Interstitial fibrosis represents a key pathological process in non-alcoholic steatohepatitis (NASH). In the liver, fibrogenesis is primarily mediated by activated hepatic stellate cells (HSCs) transitioning from a quiescent state in response to a host of stimuli. The molecular mechanism underlying HSC activation is not completely understood. Here we report that there was a simultaneous up-regulation of PIAS4 expression and down-regulation of SIRT1 expression accompanying increased hepatic fibrogenesis in an MCD-diet induced mouse model of NASH. In cultured primary mouse HSCs, stimulation with high glucose activated PIAS4 while at the same time repressed SIRT1. Over-expression of PIAS4 directly repressed SIRT1 promoter activity. In contrast, depletion of PIAS4 restored SIRT1 expression in HSCs treated with high glucose. Estrogen, a known NASH-protective hormone, antagonized HSC activation by targeting PIAS4. Lentivirus-mediated delivery of short hairpin RNA (shRNA) targeting PIAS4 in mice ameliorated MCD diet induced liver fibrosis by normalizing SIRT1 expression in vivo. PIAS4 promoted HSC activation in a SIRT1-dependent manner in vitro. Mechanistically, PIAS4 mediated SIRT1 repression led to SMAD3 hyperacetylation and enhanced SMAD3 binding to fibrogenic gene promoters. Taken together, our data suggest SIRT1 trans-repression by PIAS4 plays an important role in HSC activation and liver fibrosis.

Norepinephrine induces calcium spikes and proinflammatory actions in human hepatic stellate cells

2006 ◽  
Vol 291 (5) ◽  
pp. G877-G884 ◽  
Author(s):  
Pau Sancho-Bru ◽  
Ramón Bataller ◽  
Jordi Colmenero ◽  
Xavier Gasull ◽  
Montserrat Moreno ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Portal Hypertension ◽  
Liver Fibrosis ◽  
Hepatic Stellate Cells ◽  
Molecular Mechanisms ◽  
Nuclear Translocation ◽  
Stellate Cells ◽  
Luciferase Reporter ◽  
Dependent Manner ◽  
Cell Contraction

Catecholamines participate in the pathogenesis of portal hypertension and liver fibrosis through α1-adrenoceptors. However, the underlying cellular and molecular mechanisms are largely unknown. Here, we investigated the effects of norepinephrine (NE) on human hepatic stellate cells (HSC), which exert vasoactive, inflammatory, and fibrogenic actions in the injured liver. Adrenoceptor expression was assessed in human HSC by RT-PCR and immunocytochemistry. Intracellular Ca2+ concentration ([Ca2+]i) was studied in fura-2-loaded cells. Cell contraction was studied by assessing wrinkle formation and myosin light chain II (MLC II) phosphorylation. Cell proliferation and collagen-α1(I) expression were assessed by [3H]thymidine incorporation and quantitative PCR, respectively. NF-κB activation was assessed by luciferase reporter gene and p65 nuclear translocation. Chemokine secretion was assessed by ELISA. Normal human livers expressed α1A-adrenoceptors, which were markedly upregulated in livers with advanced fibrosis. Activated human HSC expressed α1A-adrenoceptors. NE induced multiple rapid [Ca2+]i oscillations (Ca2+ spikes). Prazosin (α1-blocker) completely prevented NE-induced Ca2+ spikes, whereas propranolol (nonspecific β-blocker) partially attenuated this effect. NE caused phosphorylation of MLC II and cell contraction. In contrast, NE did not affect cell proliferation or collagen-α1(I) expression. Importantly, NE stimulated the secretion of inflammatory chemokines (RANTES and interleukin-8) in a dose-dependent manner. Prazosin blocked NE-induced chemokine secretion. NE stimulated NF-κB activation. BAY 11-7082, a specific NF-κB inhibitor, blocked NE-induced chemokine secretion. We conclude that NE stimulates NF-κB and induces cell contraction and proinflammatory effects in human HSC. Catecholamines may participate in the pathogenesis of portal hypertension and liver fibrosis by targeting HSC.

The defense response of Caenorhabditis elegans to Cutibacterium acnes SK137 via the TIR-1-p38 MAPK signaling pathway

2021 ◽  
Author(s):  
Ayano Tsuru ◽  
Yumi Hamazaki ◽  
Shuta Tomida ◽  
Mohammad Shaokat Ali ◽  
Eriko Kage-Nakadai
Keyword(s):  
Caenorhabditis Elegans ◽  
Signaling Pathway ◽  
P38 Mapk ◽  
Defense Response ◽  
Mapk Pathway ◽  
Defense Responses ◽  
Mapk Signaling ◽  
Dependent Manner ◽  
Healthy Skin ◽  
Cutibacterium Acnes

Abstract Cutibacterium acnes plays roles in both acne disease and healthy skin ecosystem. We observed that mutations in the tir-1/SARM1 and p38 MAPK cascade genes significantly shortened Caenorhabditis elegans lifespan upon Cutibacterium acnes SK137 infection. Antimicrobial molecules were induced by SK137 in a TIR-1-dependent manner. These results suggest that defense responses against SK137 involve the TIR-1-p38 MAPK pathway in Caenorhabditis elegans.

scholarly journals Downregulation of UBC9 promotes apoptosis of activated human LX-2 hepatic stellate cells by suppressing the canonical NF-κB signaling pathway

PLoS ONE ◽  
2017 ◽  
Vol 12 (3) ◽  
pp. e0174374 ◽  
Author(s):  
Sufen Fang ◽  
Jinhua Yuan ◽  
Qing Shi ◽  
Tiantian Xu ◽  
Yao Fu ◽  
...  
Keyword(s):  
Signaling Pathway ◽  
Hepatic Stellate Cells ◽  
Stellate Cells
Sign in / Sign up

Export Citation Format

Share Document