scholarly journals Identification of a Novel lincRNA-p21-miR-181b-PTEN Signaling Cascade in Liver Fibrosis

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Fujun Yu ◽  
Zhongqiu Lu ◽  
Bicheng Chen ◽  
Peihong Dong ◽  
Jianjian Zheng

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 inα-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.

2017 ◽  
Vol 41 (5) ◽  
pp. 1970-1980 ◽  
Author(s):  
Fujun Yu ◽  
Yong Guo ◽  
Bicheng Chen ◽  
Liang Shi ◽  
Peihong Dong ◽  
...  

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.


2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Min Liu ◽  
Youwei Xu ◽  
Xu Han ◽  
Lianhong Yin ◽  
Lina Xu ◽  
...  

Abstract The present work aimed to investigate the activities and underlying mechanisms of dioscin against alcoholic liver fibrosis (ALF). In vivo liver fibrosis in mice was induced by an alcoholic liquid diet and in vitro studies were performed on activated HSC-T6 and LX2 cells treated with lipopolysaccharide. Our results showed that dioscin significantly attenuated hepatic stellate cells (HSCs) activation, improved collagen accumulation and attenuated inflammation through down-regulating the levels of myeloid differentiation factor 88 (MyD88), nuclear factor κB (NF-κB), interleukin (IL)-1, IL-6 and tumour necrosis factor-α by decreasing Toll-like receptor (TLR)4 expression both in vivo and in vitro. TLR4 overexpression was also decreased by dioscin, leading to the markedly down-regulated levels of MyD88, NF-κB, transforming growth factor-β1 (TGF-β1), α-smooth muscle actin (α-SMA) and type I collagen (COL1A1) in cultured HSCs. Suppression of cellular MyD88 by ST2825 or abrogation of NF-κB by pyrrolidine dithiocarbamate eliminated the inhibitory effects of dioscin on the levels of TGF-β1, α-SMA and COL1A1. In a word, dioscin exhibited potent effects against ALF via altering TLR4/MyD88/NF-κB signaling pathway, which provided novel insights into the mechanisms of this compound as an antifibrogenic candidate for the treatment of ALF in the future.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Lan Chen ◽  
Xiaofang Ji ◽  
Manni Wang ◽  
Xiaoyan Liao ◽  
Cuiying Liang ◽  
...  

Abstract Background Hepatic stellate cell (HSC) activation plays a pivotal role in hepatic inflammation and liver fibrosis. TLR4 pathway activation has been reported to be involved in mice liver fibrosis induced by hepatitis virus infection, alcohol abuse, biliary ligation, carbon tetrachloride 4 treatment, and Schistosoma japonicum (Sj) infection. The effect and mechanisms of the cyclooxygenase 2 (COX2)/prostanoid E2 (PGE2) axis on liver fibrosis induced by Sj are still unclear. Methods Mice liver fibrosis were induced by cutaneous infection of Sj cercariae. COX-2 inhibitor, NS398 were injected from week 5 to week 7, while TLR4 inhibitor TAK242 were injected from week 4 to week 8 post Sj infection. Human HSCs line, LX-2 cells were cultured and exposed to LPS or synthetic PGE2, or pretreated by TAK242, TLR4-siRNA or NS398. Liver tissue and serum or in vitro cultured cell lysaste were collected at indicated time courses for exploring the relationship between TLR4 and COX2-PGE2 axis through qPCR, western blot, immunohistochemical assay, ect. One-way analysis of variance among multiple groups followed by Uncorrected Fisher’s LSD-t test or paired comparisons through t test were performed to tell the statistical differences. Results This study investigated the link between the COX2/PGE2 axis and TLR4 signaling in the induction of liver fibrogenesis in mice during Sj infection and in vitro culture of HSC strain-LX-2. The COX2/PGE2 axis was positively associated with Sj-induced liver fibrosis. TLR4 pathway activation stimulated the COX2/PGE2 axis in Sj-infected mice and in lipopolysaccharide (LPS)-exposed cultured HSCs. Synthetic PGE2 activated cultured HSCs through upregulation of alpha smooth muscle actin (α-SMA) expression. In LPS-triggered HSCs, NS398, a COX2 inhibitor, led to suppression of PGE2 synthesis and reduced expression of α-SMA and type I collagen (COL I). Conclusions These results indicate firstly the positive association of the COX2/PGE2 axis with liver fibrosis induced by Sj infection. TLR4 signaling may at least partially control the COX2/PGE2 axis in Sj-infected mice liver and in vitro cultured HSCs. The COX2/PGE2-EP2/EP4 axis might be a good drug target against liver fibrosis induced by Sj infection. Graphic abstract


2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 1094.1-1094
Author(s):  
A. S. Siebuhr ◽  
P. Juhl ◽  
M. Karsdal ◽  
A. C. Bay-Jensen

Background:Interleukin 6 (IL-6) is known to have both pro- and anti-inflammatory properties, depending on the receptor activation. The classical IL-6 signaling via the membrane bound receptor is mainly anti-inflammatory, whereas signaling through the soluble receptor (sIL-6R) is pro-inflammatory/pro-fibrotic. However, the direct fibrotic effect of IL-6 stimulation on dermal fibroblasts is unknown.Objectives:We investigated the fibrotic effect of IL-6 + sIL-6R in a dermal fibroblast model and assessed fibrosis by neo-epitope biomarkers of extracellular matrix proteins.Methods:Primary healthy human dermal fibroblasts were grown for up to 17 days in DMEM medium with 0.4% fetal calf serum, ficoll (to produce a crowded environment) and ascorbic acid. IL-6 [1-90 nM]+sIL-6R [0.1-9 nM] alone or in combination with TGFβ [1 nM] were tested in three different donors. TGFβ [1 nM], PDGF-AB [3 nM] and non-stimulated cells (w/o) were used as controls. Tocilizumab (TCZ) with TGFβ + IL-6 + sIL-6R stimulation was tested in one donor. Collagen type I, III and VI formation (PRO-C1, PRO-C3 and PRO-C6) and fibronectin (FBN-C) were evaluated by validated ELISAs (Nordic Bioscience). Western blot analysis investigated signal cascades. Gene expression of selected ECM proteins was analyzed. Statistical analyses included One-way and 2-way ANOVA and area under the curve analysis.Results:formation by the end of the culture period. The fibronectin and collagen type VI signal were consistent between the three tested donors, whereas the formation of type III collagen was only increased in one donor, but in several trials. Type I collagen formation was unchanged by IL-6 + sIL-6R stimulation. The gene expression of type I collagen was induced by IL-6 + sIL-6R. Western blot analysis validated trans-signaling by the IL-6+sIL-6R stimulation as expected.IL-6 + sIL-6R stimulation in combination with TGFβ decreased fibronectin levels compared to TGFβ alone but did not reach the level of unstimulated fibroblasts. The formation of collagen type IV was generally unchanged with IL-6 + sIL-6R + TGFβ compared to TGFβ alone. Collagen type I and III formation was more scattered in the signals when IL-6 + sIL-6R was in combination with TGFβ, as the biomarker level could be either decreased or increased compared to TGFβ alone. In two studies the type I collagen level was synergistic increased by IL-6 + sIL-6R + TGFβ, whereas another study found the level to be decreased compared to TGFβ alone. The gene expression of fibronectin and type I collagen was increased with TGFβ +IL-6+sIL-6R compared to TGFβ alone.Inhibition of IL-6R by TCZ in combination with IL-6 + sIL-6R did only decrease the fibronectin level with the lowest TCZ concentration (p=0.03). TCZ alone decreased the fibronectin level in a dose-dependent manner (One-way ANOVA p=0.0002).Conclusion:We investigated the fibrotic response of dermal fibroblasts to IL-6 + sIL-6R stimulation. IL-6 modulated the fibronectin level and modulated the collagen type III formation level in a somewhat dose-dependent manner. In combination with TGFβ, IL-6 decreased collagen type I and IV formation and fibronectin. However, in this study inhibition of IL-6R by TCZ did not change the fibrotic response of the dermal fibroblasts. This study indicated that IL-6 did not induce collagen formation in dermal fibroblasts, except type III collagen formation with high IL-6 concentration.Figure:Disclosure of Interests:Anne Sofie Siebuhr Employee of: Nordic Bioscience, Pernille Juhl Employee of: Nordic Bioscience, Morten Karsdal Shareholder of: Nordic Bioscience A/S., Employee of: Full time employee at Nordic Bioscience A/S., Anne-Christine Bay-Jensen Shareholder of: Nordic Bioscience A/S, Employee of: Full time employee at Nordic Bioscience A/S.


2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Jianxia Wen ◽  
Dan Wang ◽  
Jian Wang ◽  
Ruilin Wang ◽  
Shizhang Wei ◽  
...  

Astragali Radix (AR), the dried root of Astragali Radix membranaceus (Fisch.) Bge. or Astragali Radix membranaceus (Fisch.) Bge. var. mongholicus (Bge) Hsiao, is a commonly used traditional Chinese medicine for the treatment of liver diseases. This study aimed to comprehensively evaluate the pharmacological action and explore the potential mechanism of AR on liver fibrosis. Rats were administered with carbon tetrachloride for eight weeks, followed by oral treatment with AR for six weeks. The efficacy was confirmed by measuring liver function and liver fibrosis levels. The underlying mechanisms were explored by detecting the expression of related proteins. AR significantly decreased the serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), collagen IV (COL-IV), hyaluronic acid (HA), laminin (LN), and precollagen type III (PCIII). In addition, AR inhibited the deposition of collagen and the activation of hepatic stellate cells. Those data strongly demonstrated that AR alleviated liver fibrosis by CCl4. In order to illustrate the potential inflammatory, the mRNA levels of IL-6, TNF-α, and IL-1β were detected. Subsequently, immunohistochemistry analysis was performed to further verify the expression of type I collagen. Finally, the expression of key proteins in the inflammatory signaling pathway was detected. AR significantly reduced the expression of high-mobility group box 1 (HMGB1), TLR4, Myd88, RAGE, and NF-κ B p65 genes and proteins. In addition, western blotting showed AR decreased the protein expression of RAGE, p-MEK1/2, p-ERK1/2, and p-c-Jun. Taken together, our data reveal that AR significantly inhibits liver fibrosis by intervening in the HMGB1-mediated inflammatory signaling pathway and secretion signaling pathway. This study will provide valuable references for the in-depth research and development of Astragali Radix against liver fibrosis.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Shenzong Rao ◽  
Jie Xiang ◽  
Jingsong Huang ◽  
Shangang Zhang ◽  
Min Zhang ◽  
...  

Abstract Background PRC1 (Protein regulator of cytokinesis 1) regulates microtubules organization and functions as a novel regulator in Wnt/β-catenin signaling pathway. Wnt/β-catenin is involved in development of liver fibrosis (LF). We aim to investigate effect and mechanism of PRC1 on liver fibrosis. Methods Carbon tetrachloride (CCl4)-induced mice LF model was established and in vitro cell model for LF was induced by mice primary hepatic stellate cell (HSC) under glucose treatment. The expression of PRC1 in mice and cell LF models was examined by qRT-PCR (quantitative real-time polymerase chain reaction), western blot and immunohistochemistry. MTT assay was used to detect cell viability, and western blot to determine the underlying mechanism. The effect of PRC1 on liver pathology was examined via measurement of aspartate aminotransferase (AST), alanine aminotransferase (ALT) and hydroxyproline, as well as histopathological analysis. Results PRC1 was up-regulated in CCl4-induced mice LF model and activated HSC. Knockdown of PRC1 inhibited cell viability and promoted cell apoptosis of activated HSC. PRC1 expression was regulated by Wnt3a signaling, and PRC1 could regulate downstream β-catenin activation. Moreover, PRC1 could activate glioma-associated oncogene homolog 1 (GLI1)-dependent osteopontin expression to participate in LF. Adenovirus-mediated knockdown of PRC1 in liver attenuated LF and reduced collagen deposition. Conclusions PRC1 aggravated LF through regulating Wnt/β-catenin mediated GLI1-dependent osteopontin expression, providing a new potential therapeutic target for LF treatment.


Blood ◽  
1994 ◽  
Vol 83 (9) ◽  
pp. 2508-2515 ◽  
Author(s):  
R Polanowska-Grabowska ◽  
AR Gear

Abstract Adhesion of human platelets to type I collagen under arterial flow conditions is extremely fast, being mediated primarily by the alpha 2 beta 1 integrin (glycoprotein Ia/IIa). We have investigated the involvement of cyclic nucleotides in platelet adhesion to soluble native collagen immobilized on Sepharose beads using a new microadhesion assay under arterial flow conditions. To prevent platelet stimulation by thromboxanes and adenosine diphosphate (ADP), experiments were performed with aspirin-treated platelets in the presence of ADP-removing enzyme systems such as creatine phosphate/creatine phosphokinase or apyrase. Rapid reciprocal changes in platelet adenosine 3′5′-cyclic monophosphate (cAMP) and guanosine 3′5′-cyclic monophosphate (cGMP) occurred during adhesion. cAMP levels in adherent platelets were 2.4-fold lower than in effluent platelets or in static controls, whereas cGMP levels were increased 2.4-fold. These results suggest that contact between platelets and collagen stimulates guanylate cyclase and inhibits adenylate cyclase. This occurs in the absence of the platelet release reaction. We also studied short-term effects of agents that regulate cyclic nucleotide synthesis, prostaglandin E1 (PGE1) and sodium nitroprusside (SNP). After only 3.8 seconds at 10 to 30 dyne/cm2, PGE1 (10 mumol/L) increased cAMP 16.4- fold, whereas SNP (50 mumol/L) increased cGMP ninefold and caused a 3.2- fold increase in cAMP. Both PGE1 and SNP rapidly (< 5 seconds) inhibited platelet adhesion in a dose-dependent manner that was correlated with the increase in cyclic nucleotides. Our data suggest that cAMP and cGMP play a regulatory role in the initial phases of platelet adhesion to collagen mediated by the alpha 2 beta 1 integrin receptor.


Hepatology ◽  
2019 ◽  
Vol 70 (4) ◽  
pp. 1317-1335 ◽  
Author(s):  
Runping Liu ◽  
Xiaojiaoyang Li ◽  
Weiwei Zhu ◽  
Yanyan Wang ◽  
Derrick Zhao ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document