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Background: It is known that ferroptosis promotes hepatic stellate cells (HSCs) inactivation. Arachidonate 15-Lipoxygenase (ALOX15), a ferroptosis driver gene, participates in disease progression., Purpose: Dihydrotanshinone I (DHI), an active compound from Salvia miltiorrhiza, effectively regulates HSC inactivation. Nonetheless, there still needs to be clear understanding of how DHI affects HSC ferroptosis., Methods: This study primarily investigates DHI's protective effects on liver fibrosis in vivo and in vitro. Additionally, we explored the molecular mechanisms by which DHI promotes ferroptosis in HSCs. The relationship between ALOX15 level and methylation was examined. Molecular docking was performed to confirm the targeting between early growth response protein 1 (EGR1) and DHI., Results: DHI exhibited a mitigating effect on liver fibrosis in vivo. DHI-induced inactivation of HSC by promoting ferroptosis, accompanied by an elevation in intracellular iron and reactive oxygen species (ROS) levels. Results of transcriptome sequencing and quantitative real-time PCR (qRT-PCR) confirmed the elevation of ALOX15 (a ferroptosis driver gene) in HSCs with DHI. Loss of ALOX15 inhibited DHI-induced ferroptosis. Interestingly, DNA methyltransferase 1 (DNMT1), an essential DNA methyltransferase, was downregulated by DHI. Overexpression of DNMT1 resulted in decreased ALOX15 expression in cells with DHI. Notably, transcription factor EGR1 was demonstrated to regulate DNMT1 expression. EGR1 deficiency led to an increase in DNMT1 expression, which inhibited DHI-induced ferroptosis. Molecular docking confirmed that EGR1 could serve as a direct pharmacological target of DHI., Conclusion: DHI upregulates EGR1 level, leading to decreased DNMT1 expression and increased ALOX15 demethylation, thereby promoting HSC ferroptosis and inactivation., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Background and Aims: Myofibroblasts, the primary producers of extracellular matrix, primarily originate from hepatic stellate cells (HSCs), and their activation plays a pivotal role in liver fibrosis. This study aimed to investigate the function of CXC motif ligand 14 (CXCL14) in the progression of liver fibrosis., Approach and Results: CXCL14 knockdown significantly reduced the extent of liver fibrosis. Using Ingenuity pathway analysis and qRT-PCR, activating transcription factor 3 (ATF3) was identified as a key upstream regulator of CXCL14 expression. Mechanistically, ATF3 was shown to bind to the CXCL14 promoter, promoting its transactivation by TGF-β in HSCs. Notably, both global CXCL14 deletion (CXCL14 -/- ) and HSC/myofibroblast-specific CXCL14 knockdown significantly attenuated liver fibrosis in mice. RNA-seq comparisons between CXCL14 -/- and WT mice highlighted Jak2 as the most significantly downregulated gene, implicating its role in the antifibrotic effects of CXCL14 suppression on HSC inactivation. Moreover, Jak2 overexpression reversed the inhibition of liver fibrosis caused by CXCL14 knockdown in vivo., Conclusions: These findings unveil a novel ATF3/CXCL14/Jak2 signalling axis in liver fibrosis, presenting potential therapeutic targets for the disease., (© 2024 The Author(s). Clinical and Translational Medicine published by John Wiley & Sons Australia, Ltd on behalf of Shanghai Institute of Clinical Bioinformatics.)

Introduction: Liver fibrosis is primarily driven by the activation of hepatic stellate cells (HSCs), which involves various epigenetic modifications., Objectives: N 6 -methyladenosine (m 6 A), the most prevalent RNA modification in eukaryotic cells, influences numerous physiological and pathological processes. Nevertheless, the role of insulin-like growth factor 2 mRNA-binding protein 3 (IGF2BP3), a reader gene mediating m 6 A modifications, in liver fibrosis remains unclear., Methods and Results: This study demonstrated that IGF2BP3 knockout reduces liver fibrosis by promoting HSC ferroptosis (FPT) and inactivating HSCs. Multi-omics analysis revealed that HSC-specific IGF2BP3 knockout decreased m 6 A content in Jagged1 (Jag1), a key component of the Notch signalling pathway. Furthermore, IGF2BP3 deficiency significantly reduced the expression of hairy and enhancer of split-1 (Hes1), a transcription factor in the Notch/Jag1 signalling pathway, with mRNA levels declining to 35%-62% and protein levels to 28%-35%. Additionally, it suppressed glutathione peroxidase 4 (GPX4) (decreased to approximately 31%-38%), a negative regulator of FPT, thereby facilitating HSC FPT progression and reducing profibrotic gene expression., Conclusion: These findings uncover a novel IGF2BP3/Notch/Jag1 signalling pathway involving HSC FPT, suggesting promising targets for ameliorating liver fibrosis., Key Points/highlights: IGF2BP3 deficiency inactivates Jag1 signalling. IGF2BP3 deficiency-mediated m 6 A modifications promote HSC ferroptosis. IGF2BP3 inhibition facilitates ferroptosis in HSCs via the Hes1/GPX4 axis. IGF2BP3 deficiency inactivates Jag1/Notch1/3/Hes1 signalling pathway inactivation, leading to the decrease in GPX4, which contributes to HSC ferroptosis., (© 2024 The Author(s). Clinical and Translational Medicine published by John Wiley & Sons Australia, Ltd on behalf of Shanghai Institute of Clinical Bioinformatics.)

Background: Sustained liver fibrosis may lead to cirrhosis. Activated hepatic stellate cells (HSCs) are crucial for liver fibrosis development. Ferroptosis, a newly iron-dependent regulated cell death, has been demonstrated to be involved in HSC inactivation., Purpose: Ginsenoside Rh2 (GRh2), a natural bioactive product derived from ginseng, has been shown to promote HSC inactivation. However, the effect of GRh2 on HSC ferroptosis remains unclear., Methods: We explored the effects of GRh2 on liver fibrosis in vivo and in vitro. RNA-sequence analysis was performed in HSCs after GRh2 treatment. The crosstalk between ferroptotic HSCs and macrophages was also explored., Results: GRh2 alleviated liver fibrosis in vivo. In vitro, GRh2 reduced HSC proliferation and activation via ferroptosis, with increased intracellular iron, reactive oxygen species, malondialdehyde and glutathione depletion. The expression of SLC7A11, a negative regulator of ferroptosis, was obviously reduced by GRh2. Interestingly, interferon regulatory factor 1 (IRF1), a transcription factor, was predicted to bind the promoter region of SCL7A11. The interaction between IRF1 and SCL7A11 was further confirmed by the results of chromatin immunoprecipitation and luciferase reporter assays. Furthermore, loss of IRF1 led to an increase in SCL7A11, which contributed to the suppression of HSC ferroptosis and the enhancement of HSC activation in GRh2-treated HSCs. Further studies revealed that GRh2-induced HSC ferroptosis contributed to the inhibition of macrophage recruitment via regulation of inflammation-related genes. Moreover, GRh2 caused a reduction in liver inflammation in vivo., Conclusion: Collectively, GRh2 up-regulates IRF1 expression, resulting in the suppression of SLC7A11, which contributes to HSC ferroptosis and inactivation. GRh2 ameliorates liver fibrosis through enhancing HSC ferroptosis and inhibiting liver inflammation. GRh2 may be a promising drug for treating liver fibrosis., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier GmbH.)

Long non-coding RNA-myocardial infarction-associated transcript (lncRNA-MIAT) has been reported to play an important role in the development of multiple cancers. However, the biological roles of MIAT in liver fibrosis are still unknown. In this study, the expression of MIAT is up-regulated during liver fibrosis. Silencing MIAT leads to the suppression of hepatic stellate cell (HSC) proliferation and collagen expression. Double immunofluorescence analysis additionally demonstrates that MIAT inhibition leads to the suppression of type I collagen and α-SMA in vitro. In vivo, MIAT knockdown contributes to the inhibition of fibrosis progression and collagen accumulation. MIAT is confirmed as a target of miR-3085-5p, and the co-location of MIAT and miR-3085-5p is found in HSC cytoplasm. Interestingly, there is a negative correlation between MIAT expression and miR-3085-5p level in cirrhotic patients as well as activated HSCs. In addition, the effects of MIAT inhibition on HSC inactivation are blocked down by miR-3085-5p inhibitor. YAP is a target of miR-3085-5p. Reduced YAP caused by loss of MIAT is reversed by miR-3085-5p inhibitor. Notably, YAP knockdown results in the suppression of MIAT-mediated epithelial-to-mesenchymal transition (EMT) process. In conclusion, we demonstrate that MIAT enhances the activation of HSCs, at least in part, via miR-3085-5p/YAP/EMT signaling pathway., (© 2023. The Author(s).)

Liver fibrosis, which results from chronic liver injury due to factors such as chronic alcohol consumption, hepatitis virus infections, and immune attacks, is marked by excessive deposition of extracellular matrix (ECM). Resveratrol (Res), a polyphenol phytoalexin, has been demonstrated to show anti-inflammatory, antioxidative, antiproliferative, and chemopreventive activities. In recent years, Res has been found to inhibit liver fibrosis. Enhanced Hippo pathway activation has also been reported to inhibit tumor progression and liver fibrosis. In the present study, the role of the Hippo pathway in mediating the effects of Res on hepatic stellate cells (HSCs) was examined. We found that Res significantly suppresses HSC proliferation, reducing the cell index. Res induced HSC inactivation, reducing collagen deposition and α -smooth muscle actin ( α -SMA) expression. In addition, Res contributed to HSC apoptosis, upregulating Bax and downregulating Bcl-2 expression. Notably, the Hippo pathway was involved in the Res-mediated suppression of HSC activation. Res enhanced the activation of the Hippo pathway and reduced yes-associated protein (YAP) and transcriptional coactivator with the PDZ-binding motif (TAZ) expression. Interestingly, the YAP overexpression inhibited Res-induced HSC inactivation and apoptosis. In conclusion, these results demonstrate that Res inhibits HSC activation, at least in part, via the Hippo pathway. The present study indicates a new antifibrotic mechanism of Res and provides novel insights into Hippo-mediated HSC apoptosis and HSC activation in liver fibrosis., Competing Interests: The authors declare that they have no competing interests., (Copyright © 2021 Chunxue Li et al.)

Background: In the development of liver fibrosis, activated hepatic stellate cells (HSCs) contribute to the synthesis and deposition of extracellular matrix (ECM) proteins. HSC activation is considered as a central driver of liver fibrosis. Recently, microRNAs (miRNAs) have been reported to act as key regulators in HSC activation., Purpose: Pinostilbene hydrate (PSH), a methylated derivative of resveratrol, has demonstrated anti-inflammatory, antioxidant and anti-tumour activities. However, the effects of PSH on HSC activation remain unclear., Methods: The effects of PSH on HSC activation were examined. Moreover, the roles of WNT inhibitory factor 1 (WIF1) and miR-17-5p in the effects of PSH on HSC activation were examined., Results: PSH induced a significant reduction in HSC proliferation. PSH also effectively inhibited HSC activation, with reduced α-SMA and collagen expression. Notably, it was found that Wnt/β-catenin signalling was involved in the effects of PSH on HSC activation. PSH resulted in Wnt/β-catenin signalling inactivation, with a reduction in TCF activity as well as β-catenin nuclear translocation. Further studies showed that PSH inhibited Wnt/β-catenin signalling via regulation of WIF1 and miR-17-5p. Reduced HSC activation caused by PSH could be restored by loss of WIF1 or miR-17-5p mimics. Luciferase reporter assays further confirmed that WIF1 was a target of miR-17-5p., Conclusion: PSH has a significant protective effect against HSC activation. In addition, we demonstrate that PSH enhances WIF1 expression and inhibits Wnt/β-catenin signalling via miR-17-5p, contributing to the suppression of HSC activation., (Copyright © 2020 Elsevier GmbH. All rights reserved.)

Increasing studies have indicated that hypoxia serves as a pivotal microenvironmental factor that facilitates activation of hepatic stellate cells (HSCs). However, the mechanism by which hypoxia activates HSCs is not clear. Here, we demonstrated that plasmacytoma variant translocation 1 (PVT1) and autophagy were overexpressed in liver fibrotic specimens. In primary mouse HSCs, both PVT1 and autophagy were induced by hypoxia. Further study showed that hypoxia-induced autophagy depended on expression of PVT1 and miR-152 in HSCs. Luciferase reporter assay indicated that autophagy-related gene 14 (ATG14) was a direct target of miR-152. In addition, inhibition of autophagy by 3-methyladenine and Beclin-1 siRNA impeded activation of HSCs cultured in 1% O 2 . Taken together, autophagy induction via the PVT1-miR-152-ATG14 signaling pathway contributes to activation of HSCs under hypoxia condition.

HOXA transcript at the distal tip (HOTTIP) has been shown to be up-regulated in a variety of cancers and is identified as an oncogenic long noncoding RNA. However, the biological role of HOTTIP in liver fibrosis is unclear. Here, we reported that HOTTIP was specifically overexpressed in activated hepatic stellate cells (HSCs). HOTTIP knockdown suppressed the activation and proliferation of HSCs. Luciferase reporter assay showed that HOTTIP and serum response factor (SRF) were targets of miR-150. RNA binding protein immunoprecipitation assay indicated the interaction between miR-150 and HOTTIP. Further study revealed that HOTTIP increased SRF expression as a competing endogenous RNA for miR-150, thus prompting HSC activation. Taken together, we provide a novel HOTTIP-miR-150-SRF signalling cascade in liver fibrosis., (© 2018 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.)

Activation of hepatic stellate cells (HSCs), a pivotal event in liver fibrosis, is considered as an epithelial-mesenchymal transition (EMT) process. Deregulation of long noncoding RNAs (lncRNAs) has been reported to be involved in a series of human diseases. LncRNA-maternally expressed gene 3 (MEG3) functions as a tumor suppressor in cancers and has been shown to play a vital role in EMT process. However, the biological role of MEG3 in liver fibrosis is largely unknown. In this study, MEG3 was reduced in vivo and in vitro during liver fibrosis. Restoring of MEG3 expression led to the suppression of liver fibrosis, with a reduction in α-SMA and type I collagen. Notably, MEG3 overexpression inhibited HSC activation through EMT, associated with an increase in epithelial markers and a reduction in mesenchymal markers. Further studies showed that Hedgehog (Hh) pathway-mediated EMT process was involved in the effects of MEG3 on HSC activation. Smoothened (SMO) is a member of Hh pathway. Using bioinformatic analysis, an interaction between MEG3 and SMO protein was predicted. This interaction was confirmed by the results of RNA immunoprecipitation and deletion-mapping analysis. Furthermore, MEG3 was confirmed as a target of microRNA-212 (miR-212). miR-212 was partly responsible for the effects of MEG3 on EMT process. Interestingly, MEG3 was also reduced in chronic hepatitis B (CHB) patients with liver fibrosis when compared with healthy controls. MEG3 negatively correlated with fibrosis stage in CHB patients. In conclusion, we demonstrate that MEG3 inhibits Hh-mediated EMT process in liver fibrosis via SMO protein and miR-212.

Background/aims: It is known that the activation of hepatic stellate cells (HSCs) is a pivotal step in the initiation and progression of liver fibrosis. Aberrant activated Wnt/β-catenin pathway is known to accelerate the development of liver fibrosis. microRNAs (miRNAs)-mediated Wnt/β-catenin pathway has been reported to be involved in HSC activation during liver fibrosis. However, whether long noncoding RNAs (lncRNAs) regulate Wnt/β-catenin pathway during HSC activation still remains unclear., Methods: Long intergenic noncoding RNA-p21 (lincRNA-p21) expression was detected in Salvianolic acid B (Sal B)-treated cells. Effects of lincRNA-p21 knockdown on HSC activation and Wnt/β-catenin pathway activity were analyzed in Sal B-treated cells. In lincRNA-p21-overexpressing cells, effects of miR-17-5p on HSC activation and Wnt/β-catenin pathway activity were examined., Results: LincRNA-p21 expression was up-regulated in HSCs after Sal B treatment. In primary HSCs, lincRNA-p21 expression was down-regulated at Day 5 relative to Day 2. Sal B-inhibited HSC activation including the reduction of cell proliferation, α-smooth muscle actin (α-SMA) and type I collagen was inhibited by lincRNA-p21 knockdown. Sal B-induced Wnt/β-catenin pathway inactivation was blocked down by loss of lincRNA-p21. Notably, lincRNA-p21, confirmed as a target of miR-17-5p, suppresses miR-17-5p level. Lack of the miR-17-5p binding site in lincRNA-p21 prevents the suppression of miR-17-5p expression. In addition, the suppression of HSC activation and Wnt/β-catenin pathway induced by lincRNA-p21 overexpression was almost inhibited by miR-17-5p., Conclusion: We demonstrate that lincRNA-p21-inhibited Wnt/β-catenin pathway is involved in the effects of Sal B on HSC activation and lincRNA-p21 suppresses HSC activation, at least in part, via miR-17-5p-mediated-Wnt/β-catenin pathway., (© 2017 The Author(s)Published by S. Karger AG, Basel.)

Epithelial-mesenchymal transition (EMT) process is considered as a key event in the activation of hepatic stellate cells (HSCs). Hedgehog (Hh) pathway is known to be required for EMT process. Long non-coding RNAs (lncRNAs) have been reported to be involved in a wide range of biological processes. Plasmacytoma variant translocation 1 (PVT1), a novel lncRNA, is often up-regulated in various human cancers. However, the role of PVT1 in liver fibrosis remains undefined. In this study, PVT1 was increased in fibrotic liver tissues and activated HSCs. Depletion of PVT1 attenuated collagen deposits in vivo. In vitro, PVT1 down-regulation inhibited HSC activation including the reduction of HSC proliferation, α-SMA and type I collagen. Further studies showed that PVT1 knockdown suppressed HSC activation was through inhibiting EMT process and Hh pathway. Patched1 (PTCH1), a negative regulator factor of Hh pathway, was enhanced by PVT1 knockdown. PTCH1 demethylation caused by miR-152 was responsible for the effects of PVT1 knockdown on PTCH1 expression. Notably, miR-152 inhibitor reversed the effects of PVT1 knockdown on HSC activation. Luciferase reporter assays and pull-down assays showed a direct interaction between miR-152 and PVT1. Collectively, we demonstrate that PVT1 epigenetically down-regulates PTCH1 expression via competitively binding miR-152, contributing to EMT process in liver fibrosis.

Background/aims: Wnt/β-catenin pathway is involved in liver fibrosis and microRNAs (miRNAs) are considered as key regulators of the activation of hepatic stellate cells (HSCs). A recent study showed the protective role of miR-378a-3p against cardiac fibrosis. However, whether miR-378a-3p suppresses Wnt/β-catenin pathway in liver fibrosis is largely unknown., Methods: miR-378a-3p expression was detected in carbon tetrachloride-induced liver fibrosis and activated HSCs. Effects of miR-378a-3p overexpression on HSC activation and Wnt/β-catenin pathway were analyzed. Bioinformatic analysis was employed to identify the potential targets of miR-378a-3p. Serum miR-378a-3p expression was analyzed in patients with cirrhosis., Results: Reduced miR-378a-3p expression was observed in the fibrotic liver tissues and activated HSCs. Up-regulation of miR-378a-3p inhibited HSC activation including cell proliferation, α-smooth muscle actin (α-SMA) and collagen expression. Moreover, miR-378a-3p overexpression resulted in Wnt/β-catenin pathway inactivation. Luciferase reporter assays demonstrated that Wnt10a, a member of Wnt/β-catenin pathway, was confirmed to be a target of miR-378a-3p. By contrast, miR-378a-3p inhibitor contributed to HSC activation, with an increase in cell proliferation, α-SMA and collagen expression. But all these effects were blocked down by silencing of Wnt10a. Notably, sera from patients with cirrhosis contained lower levels of miR-378a-3p than sera from healthy controls. Receiver operating characteristic curve analysis suggested that serum miR-378a-3p differentiated liver cirrhosis patients from healthy controls, with an area under the curve of ROC curve of 0.916., Conclusion: miR-378a-3p suppresses HSC activation, at least in part, via targeting of Wnt10a, supporting its potential utility as a novel therapeutic target for liver fibrosis., (© 2016 The Author(s) Published by S. Karger AG, Basel.)

Background/aims: In liver fibrosis, the activation of hepatic stellate cells (HSCs) is considered as a pivotal event. It is well known that transforming growth factor-β1 (TGF-β1) is the main stimuli factor responsible for HSC activation. microRNAs (miRNAs), regulating various biological processes, have recently been shown to be involved in HSC activation. A recent study reported that deficiency of miR-378a contributes to cardiac fibrosis via TGF-β1-dependent paracrine mechanism. However, the involvement of miR-378a and its roles in TGF-β1-induced HSC activation remains largely unknown., Methods: miR-378a expression was detected in TGF-β1-treated cells and patients with cirrhosis. Then, effects of miR-378a overexpression on cell proliferation and HSC activation were analyzed. We also analyzed the binding of miR-378a to the 3'-untranslated region of TGF-β2., Results: In response to TGF-β1, miR-378a expression was down-regulated in a dose-dependent manner. miR-378a overexpression suppressed both cell proliferation and cell cycle in TGF-β1-treated LX-2 cells. Moreover, miR-378a overexpression inhibited TGF-β1-induced HSC activation including the reduction of α-smooth muscle actin (α-SMA) and type I collagen. Similarly, miR-378a resulted in a reduction in cell proliferation, and the expressions of α-SMA and Col1A1 in TGF-β1-treated primary HSCs. Notably, TGF-β2 was confirmed as a target of miR-378a by luciferase reporter assays. Interestingly, miR-378a promoter methylation may be responsible for miR-378a down-regulation in TGF-β1-treated LX-2 cells and TGF-β1-treated primary HSCs. Further studies confirmed that reduced miR-378a was associated with promoter methylation in patients with cirrhosis compared with healthy controls., Conclusion: Our results demonstrate that miR-378a expression is associated with its methylation status in TGF-β1-treated cells, and epigenetically-regulated miR-378a inhibits TGF-β1-induced HSC activation, at least in part, via TGF-β2., (© 2016 The Author(s) Published by S. Karger AG, Basel.)

Previously, we found that long intergenic noncoding RNA-p21 (lincRNA-p21) inhibits hepatic stellate cell (HSC) activation and liver fibrosis via p21. However, the underlying mechanism of the antifibrotic role of lincRNA-p21 in liver fibrosis remains largely unknown. Here, we found that lincRNA-p21 expression was significantly downregulated during liver fibrosis. In LX-2 cells, the reduction of lincRNA-p21 induced by TGF-β1 was in a dose- and time-dependent manner. lincRNA-p21 expression was reduced in liver tissues from patients with liver cirrhosis when compared with that of healthy controls. Notably, lincRNA-p21 overexpression contributed to the suppression of HSC activation. lincRNA-p21 suppressed HSC proliferation and induced a significant reduction in α-SMA and type I collagen. All these effects induced by lincRNA-p21 were blocked down by the loss of PTEN, suggesting that lincRNA-p21 suppressed HSC activation via PTEN. Further study demonstrated that microRNA-181b (miR-181b) was involved in the effects of lincRNA-p21 on HSC activation. The effects of lincRNA-p21 on PTEN expression and HSC activation were inhibited by miR-181b mimics. We demonstrated that lincRNA-p21 enhanced PTEN expression by competitively binding miR-181b. In conclusion, our results disclose a novel lincRNA-p21-miR-181b-PTEN signaling cascade in liver fibrosis and suggest lincRNA-p21 as a promising molecular target for antifibrosis therapy.

Long non-coding RNAs are involved in various biological processes and diseases. The biological role of long intergenic non-coding RNA-p21 (lincRNA-p21) in liver fibrosis remains unknown before this study. In this study, we observed marked reduction of lincRNA-p21 expression in mice liver fibrosis models and human cirrhotic liver. Over-expression of lincRNA-p21 suppressed activation of hepatic stellate cells (HSCs) in vitro. Lentivirus-mediated lincRNA-p21 transfer into mice decreased the severity of liver fibrosis in vivo. Additionally, lincRNA-p21 reversed the activation of HSCs to their quiescent phenotype. The mRNA levels of lincRNA-p21 and p21 were positively correlated. Our results show that over-expression of lincRNA-p21 promotes up-regulation of p21 at both the mRNA and protein levels. Furthermore, lincRNA-p21 inhibited cell-cycle progression and proliferation of primary HSCs through enhancement of p21 expression. Compared with healthy subjects, serum lincRNA-p21 levels were significantly lower in patients with liver cirrhosis, especially those with decompensation. These findings collectively indicate that lincRNA-p21 is a mediator of HSC activation, supporting its utility as a novel therapeutic target for liver fibrosis., (© 2015 FEBS.)

In this study, we aimed at assessing a role of Alu-mediated p21 transcriptional regulator (APTR) in hepatofibrogenesis. APTR was upregulated in fibrotic liver samples and activated hepatic stellate cells (HSCs). Knockdown of APTR inhibited the activation of HSCs in vitro and mitigated the accumulation of collagen in vivo. Importantly, APTR silencing could abrogate TGF-β1-induced upregulation of α-SMA in HSCs. In addition, inhibition of cell cycle and cell proliferation by APTR knockdown was attenuated by p21 siRNA1 in primary HSCs. Finally, serum APTR levels were increased in patients with liver cirrhosis, indicating a potential biomarker for liver cirrhosis. Collectively, evidence is proposed for a new biological role of APTR in hepatofibrogenesis., (Copyright © 2015 Elsevier Inc. All rights reserved.)

A considerable amount of research has focused on the roles of microRNAs (miRNA) in the pathophysiology of liver fibrosis in view of their regulatory effects on hepatic stellate cell (HSC) functions, including proliferation, differentiation, and apoptosis. Recently, miR-17-5p was shown to promote cell proliferation and migration in liver. Transforming growth factor-β1 (TGF-β1) has been characterized as the master fibrogenic cytokine that stimulates HSC activation and promotes progression of liver fibrosis. The issue of whether miR-17-5p plays a role in TGF-β1-induced hepatic fibrogenesis remains to be established. In this study, we demonstrated a dose-/time-dependent increase in miR-17-5p expression in TGF-β1-treated HSCs. Enhanced miR-17-5p expression was additionally observed in CCl4-induced rat liver fibrosis. Inhibition of miR-17-5p led to suppression of HSC proliferation induced by TGF-β1 without affecting cellular apoptosis. Notably, miR-17-5p was significantly associated with TGF-β1-induced expression of type I collagen and α-SMA in HSC. Furthermore, Smad7, a negative regulator of the TGF-β/Smad pathway, was confirmed as a direct target of miR-17-5p. Serum miR-17-5p levels were significantly higher in patients with cirrhosis, compared to healthy controls. Our results collectively indicate that miR-17-5p promotes HSC proliferation and activation, at least in part, via reduction of Smad7, supporting its potential utility as a novel therapeutic target for liver fibrosis.

Activation of hepatic stellate cells (HSCs) is an essential event in the initiation and progression of liver fibrosis. MicroRNAs have been shown to play a pivotal role in regulating HSC functions such as cell proliferation, differentiation, and apoptosis. Recently, miR-181b has been reported to promote HSCs proliferation by targeting p27. But whether alpha-smooth muscle actin (α-SMA) or collagens could be promoted by miR-181b in activated HSCs is still not clear. Therefore, the understanding of the role of miR-181b in liver fibrosis remains limited. Our results showed that miR-181b expression was increased much higher than miR-181a expression in vitro in transforming growth factor-β1-induced HSC activation as well as in vivo in carbon tetrachloride-induced rat liver fibrosis. Of note, overexpression of miR-181b significantly increased the expressions level of α-SMA and type I collagen, and further promoted HSCs proliferation. Furthermore, phosphatase and tensin homologs deleted on chromosome 10 (PTEN), a negative regulator of PI3K/Akt pathway, were confirmed as a direct target of miR-181b. We demonstrated that miR-181b could suppress PTEN expression and increase Akt phosphorylation in HSCs. Interestingly, the effects of miR-181b on the activation of HSCs were blocked down by Akt inhibitor LY294002. Our results revealed a profibrotic role of miR-181b in HSC activation and demonstrated that miR-181b could activate HSCs, at least in part, via PTEN/Akt pathway.

Phosphatase and tensin homologue deleted on chromosome 10 (PTEN) has been reported to play a role in the suppression of activated hepatic stellate cells (HSCs). Moreover, it has been demonstrated that hypermethylation of the PTEN promoter is responsible for the loss of PTEN expression during HSC activation. Methylation is now established as a fundamental regulator of gene transcription. MicroRNAs (miRNAs), which can control gene expression by binding to their target genes for degradation and/or translational repression, were found to be involved in liver fibrosis. However, the mechanism responsible for miRNA-mediated epigenetic regulation in liver fibrosis still remained unclear. In the present study, curcumin treatment significantly resulted in the inhibition of cell proliferation and an increase in the apoptosis rate through the up-regulation of PTEN associated with a decreased DNA methylation level. Only DNA methyltransferase 3b (DNMT3b) was reduced in vivo and in vitro after curcumin treatment. Further studies were performed aiming to confirm that the knockdown of DNMT3b enhanced the loss of PTEN methylation by curcumin. In addition, miR-29b was involved in the hypomethylation of PTEN by curcumin. MiR-29b not only was increased by curcumin in activated HSCs, but also was confirmed to target DNMT3b by luciferase activity assays. Curcumin-mediated PTEN up-regulation, DNMT3b down-regulation and PTEN hypomethylation were all attenuated by miR-29b inhibitor. Collectively, it is demonstrated that curcumin can up-regulate miR-29b expression, resulting in DNMT3b down-regulation in HSCs and epigenetically-regulated PTEN involved in the suppression of activated HSCs. These results indicate that miRNA-mediated epigenetic regulation may be a novel mechanism suppressing liver fibrosis., (© 2013 FEBS.)

microRNAs (miRNAs) have recently been reported to be involved in the progression of liver fibrosis. It has previously been shown that miR-150 can inhibit the activation of hepatic stellate cells (HSCs) via the inhibition of C-myb expression. However, the reduced C-myb expression is not responsible for all the effects of miR-150, there may be other molecular mechanisms for the suppression of HSCs by miR-150. In this study, gene array analysis was performed to analyze the miRNAs that were differentially expressed between LX-2 cells induced by transforming growth factor-β1 (TGF-β1) and the control. Our results indicated that the expression of miR-150 was significantly reduced during liver fibrosis. Of note, the reduction of miR-150 induced by TGF-β1 was in a dose- and time-dependent manner. In addition, miR-150 overexpression in LX-2 cells resulted in the inhibition of cell proliferation and the reduction of extracellular matrix proteins and α-smooth muscle actin (α-SMA). However, there was no significant change in the rate of apoptosis in cells transfected with miR-150 mimics compared with the control. Sp1, a mediator of α-1 (I) collagen (Col1A1) expression, and Col4A4 were found to be the targets for miR-150. Also, miR-150 mimics were found to decrease the expression of Sp1 and Col4A4. Smad2 and p-Smad2, the upstream mediators of Sp1, were not affected by miR-150. The same result was also seen in the levels of Smad3 and p-Smad3. Collectively, we conclude that miR-150 can reduce type Ⅰ and IV collagen by directly binding to Sp1 and Col4A4 without the involvement of upstream of the TGF-β/Smad pathway.

Liver fibrosis is primarily driven by the activation of hepatic stellate cells (HSCs), a process associated with ferroptosis. Ginsenoside Rb1 (GRb1), a major active component extracted from Panax ginseng, inhibits HSC activation. However, the potential role of GRb1 in mediating HSC ferroptosis remains unclear. This study examined the effect of GRb1 on liver fibrosis both in vivo and in vitro , using CCl 4 -induced liver fibrosis mouse model and primary HSCs, LX-2 cells. The findings revealed that GRb1 effectively inactivated HSCs in vitro , reducing alpha-smooth muscle actin (α-SMA) and type I collagen (Col1A1) levels. Moreover, GRb1 significantly alleviated CCl 4 -induced liver fibrosis in vivo. From a mechanistic standpoint, the ferroptosis pathway appeared to be central to the antifibrotic effects of GRb1. Specifically, GRb1 promoted HSC ferroptosis both in vivo and in vitro , characterized by increased glutathione depletion, malondialdehyde production, iron overload, and accumulation of reactive oxygen species (ROS). Intriguingly, GRb1 increased Beclin 1 (BECN1) levels and decreased the System Xc-key subunit SLC7A11. Further experiments showed that BECN1 silencing inhibited GRb1-induced effects on HSC ferroptosis and mitigated the reduction of SLC7A11 caused by GRb1. Moreover, BECN1 could directly interact with SLC7A11, initiating HSC ferroptosis. In conclusion, the suppression of BECN1 counteracted the effects of GRb1 on HSC inactivation both in vivo and in vitro. Overall, this study highlights the novel role of GRb1 in inducing HSC ferroptosis and promoting HSC inactivation, at least partly through its modulation of BECN1 and SLC7A11. [Display omitted] • GRb1 effectively inactivated HSC and alleviated CCl 4 -induced liver fibrosis. • GRb1 promotes HSC inactivation via ferroptosis pathway, and this is a first report. • BECN1 is the key medium in the ferroptosis process induced by GRb1. • GRb1-induced HSC ferroptosis is via BECN1/SLC7A11 axis. [ABSTRACT FROM AUTHOR]

Background/Aims: The activation of hepatic stellate cells (HSCs) is considered as a pivotal event in liver fibrosis and epithelial-mesenchymal transition (EMT) process has been reported to be involved in HSC activation. It is known that microRNAs (miRNAs) play a pro-fibrotic or anti-fibrotic role in HSC activation. Recently, emerging studies show that miR-30a is down-regulated in human cancers and over-expression of miR-30a inhibits tumor growth and invasion via suppressing EMT process. However, whether miR-30a could regulate EMT process in HSC activation is still unclear. Methods: miR-30a expression was quantified using real-time PCR in carbon tetrachloride (CCl4)-induced rat liver fibrosis, activated HSCs and patients with cirrhosis. Roles of miR-30a in liver fibrosis in vivo and in vitro were also analyzed. Luciferase activity assays were performed to examine the binding of miR-30a to the 3′-untranslated region of snail family transcriptional repressor 1 (Snai1). Results: miR-30a was down-regulated in human cirrhotic tissues. In CCl4 rats, reduced miR-30a was found in fibrotic liver tissues as well as isolated HSCs. There was a significant reduction in miR-30a in primary HSCs during culture days. miR-30a over-expression resulted in the suppression of CCl4-induced liver fibrosis. Restoration of miR-30a led to the inhibition of HSC activation including cell proliferation, α-SMA and collagen expression. Notably, miR-30a inhibited EMT process, with a reduction in TGF-β1 and Vimentin as well as an increase in GFAP and E-cadherin. miR-30a induced a significant reduction in Snai1 protein expression when compared with the control. Interestingly, Snail protein expression was increased during liver fibrosis, indicating that there may be a negative correlation between miR-30a level and Snai1 protein expression. Further studies demonstrated that Snai1 was a target of miR-30a. Conclusion: Our results suggest that miR-30a inhibits EMT process, at least in part, via reduction of Snai1, leading to the suppression of HSC activation in liver fibrosis. [ABSTRACT FROM AUTHOR]

Serum long non-coding RNAs (lnc RNAs) are emerging as promising biomarkers for various human diseases. The aim of this study was to investigate the feasibility of using serum long intergenic non-coding RNA-p21 (linc RNA-p21) as a biomarker for chronic hepatitis B patients. Serum linc RNA-p21 levels were quantified using real-time PCR in 417 CHB patients and 363 healthy controls. The promoter methylation level of linc RNA-p21 was detected using bisulphite-sequencing analysis in primary hepatic stellate cells ( HSCs). Sera from hepatitis B-infected patients contained lower levels of linc RNA-p21 than sera from healthy controls. Serum linc RNA-p21 levels negatively correlated with stages of liver fibrosis in infected patients. Receiver operating characteristic ( ROC) curve analyses suggested that serum linc RNA-p21 had a significant diagnostic value for liver fibrosis in these patients. It yielded an area under the curve of ROC of 0.854 with 100% sensitivity and 70% specificity in discriminating liver fibrosis from healthy controls. There was additionally a negative correlation between serum linc RNA-p21 level and the markers of liver fibrosis including α- SMA and Col1A1. However, there was no correlation of serum linc RNA-p21 level with the markers of viral replication, liver inflammatory activity, and liver function. Notably, during primary HSCs culture, loss of linc RNA-p21 expression was associated with promoter methylation. Serum linc RNA-p21 could serve as a potential biomarker of liver fibrosis in CHB patients. Down-regulation of linc RNA-p21 in liver fibrosis may be associated with promoter methylation. [ABSTRACT FROM AUTHOR]

Background/Aims: Emerging evidence shows that microRNAs (miRNAs) play a crucial role in the regulation of activation, proliferation and apoptosis of hepatic stellate cells (HSCs). Previous studies have indicated that miR-125a-5p is correlated with hepatitis B virus replication and disease progression. However, little is known about the biological role and underlying mechanism of miR-125a-5p in liver fibrosis. Methods: We analyzed the level of miR-125a-5p in carbon tetrachloride-induced liver fibrosis and activated HSCs. We analyzed the effects of miR-125a-5p down-regulation on HSC activation and proliferation. We also analyzed the binding of miR-125a-5p to the 3'-untranslated region of factor inhibiting hypoxia-inducible factor 1 (FIH1) mRNA. Results: Up-regulation of miR-125a-5p was observed in the liver tissues of fibrotic mice and activated HSCs. Down-regulation of miR-125a-5p prevented the activation and proliferation of HSCs. FIH1, a negative modulator of hypoxia inducible factor 1, was confirmed to be a target of miR-125a-5p using the luciferase reporter assay. Further studies demonstrated that miR-125a-5p prompted the activation and proliferation of HSCs, at least in part, by down-regulating FIH1. Conclusion: Our findings shed new light on miRNAs as a promising therapeutic target in liver fibrosis. [ABSTRACT FROM AUTHOR]

Epithelial-mesenchymal transition ( EMT) was reported to be involved in the activation of hepatic stellate cells ( HSCs), contributing to the development of liver fibrosis. Epithelial-mesenchymal transition can be promoted by the Hedgehog (Hh) pathway. Patched1 ( PTCH1), a negative regulatory factor of the Hh signalling pathway, was down-regulated during liver fibrosis and associated with its hypermethylation status. Micro RNAs (mi RNAs) are reported to play a critical role in the control of various HSCs functions. However, mi RNA-mediated epigenetic regulations in EMT during liver fibrosis are seldom studied. In this study, Salvianolic acid B (Sal B) suppressed the activation of HSCs in CCl4-treated mice and mouse primary HSCs, leading to inhibition of cell proliferation, type I collagen and alpha-smooth muscle actin. We demonstrated that the antifibrotic effects caused by Sal B were, at least in part, via inhibition of EMT and the Hh pathway. In particular, up-regulation of PTCH1 was associated with decreased DNA methylation level after Sal B treatment. Accordingly, DNA methyltransferase 1 ( DNMT1) was attenuated by Sal B in vivo and in vitro. The knockdown of DNMT1 in Sal B-treated HSCs enhanced PTCH1 expression and its demethylation level. Interestingly, increased miR-152 in Sal B-treated cells was responsible for the hypomethylation of PTCH1 by Sal B. As confirmed by the luciferase activity assay, DNMT1 was a direct target of miR-152. Further studies showed that the miR-152 inhibitor reversed Sal B-mediated PTCH1 up-regulation and DNMT1 down-regulation. Collectively, miR-152 induced by Sal B, contributed to DNMT1 down-regulation and epigenetically regulated PTCH1, resulting in the inhibition of EMT in liver fibrosis. [ABSTRACT FROM AUTHOR]

Phosphatase and tensin homologue deleted on chromosome 10 ( PTEN) has been reported to play a role in the suppression of activated hepatic stellate cells ( HSCs). Moreover, it has been demonstrated that hypermethylation of the PTEN promoter is responsible for the loss of PTEN expression during HSC activation. Methylation is now established as a fundamental regulator of gene transcription. Micro RNAs (mi RNAs), which can control gene expression by binding to their target genes for degradation and/or translational repression, were found to be involved in liver fibrosis. However, the mechanism responsible for mi RNA-mediated epigenetic regulation in liver fibrosis still remained unclear. In the present study, curcumin treatment significantly resulted in the inhibition of cell proliferation and an increase in the apoptosis rate through the up-regulation of PTEN associated with a decreased DNA methylation level. Only DNA methyltransferase 3b ( DNMT3b) was reduced in vivo and in vitro after curcumin treatment. Further studies were performed aiming to confirm that the knockdown of DNMT3b enhanced the loss of PTEN methylation by curcumin. In addition, miR-29b was involved in the hypomethylation of PTEN by curcumin. MiR-29b not only was increased by curcumin in activated HSCs, but also was confirmed to target DNMT3b by luciferase activity assays. Curcumin-mediated PTEN up-regulation, DNMT3b down-regulation and PTEN hypomethylation were all attenuated by miR-29b inhibitor. Collectively, it is demonstrated that curcumin can up-regulate miR-29b expression, resulting in DNMT3b down-regulation in HSCs and epigenetically-regulated PTEN involved in the suppression of activated HSCs. These results indicate that mi RNA-mediated epigenetic regulation may be a novel mechanism suppressing liver fibrosis. [ABSTRACT FROM AUTHOR]