scholarly journals Dihydromyricetin Reverses Thioacetamide-Induced Liver Fibrosis Through Inhibiting NF-κB-Mediated Inflammation and TGF-β1-Regulated of PI3K/Akt Signaling Pathway

2021 ◽  
Vol 12 ◽  
Author(s):  
Yingchun Zhao ◽  
Xinglong Liu ◽  
Chuanbo Ding ◽  
Yan Gu ◽  
Wencong Liu

As a natural active substance, dihydromyricetin (DHM) has been proven to have good hepatoprotective activity. However, the therapeutic effect of DHM on liver fibrosis, which has become a liver disease threatening the health of people around the world, has not been studied to date. The purpose of this study was to investigate the effect of DHM as a new nutritional supplement on thioacetamide (TAA)-induced liver fibrosis. The liver fibrosis model was established by intraperitoneal injection of TAA (200 mg/kg, every 3 days) for 8 weeks, and oral administration of DHM (20 mg/kg and 40 mg/kg, daily) after 4 weeks of TAA-induced liver fibrosis. The results showed that DHM treatment significantly inhibited the activities of alanine aminotransferase (ALT) (37.81 ± 7.62 U/L) and aspartate aminotransferase (AST) (55.18 ± 10.94 U/L) in serum of liver fibrosis mice, and increased the levels of superoxide dismutase (SOD) and glutathione (GSH) while reversed the level of malondialdehyde (MDA). In addition, histopathological examination illustrated that TAA induced the inflammatory infiltration, apoptosis and fibroatherosclerotic deposition in liver, which was further confirmed by western-blot and immunofluorescence staining. Moreover, DHM inhibited hepatocyte apoptosis by regulating the phosphorylation level of phosphatidylinositol 3-kinase (PI3K), protein kinase-B (AKT) and its downstream apoptotic protein family. Interestingly, immunofluorescence staining showed that DHM treatment significantly inhibited alpha smooth muscle actin (α-SMA), which was a marker of hepatic stellate cell activation, and regulated the expression of transforming growth factor (TGF-β1). Importantly, supplementation with DHM significantly inhibited the release of nuclear factor kappa-B (NF-κB) signaling pathway and pro-inflammatory factors in liver tissue induced by TAA, and improved liver fiber diseases, such as tumor necrosis factor alpha (TNF-α) and recombinant rat IL-1β (IL-1β). In conclusion, the evidence of this study revealed that DHM is a potential hepatoprotective and health factor, and which also provides the possibility for the treatment of liver fibrosis.

2018 ◽  
Vol 51 (5) ◽  
pp. 2111-2122 ◽  
Author(s):  
Yi-Bing Hu ◽  
Xiao-Ting Ye ◽  
Qing-Qing Zhou ◽  
Rong-Quan Fu

Background/Aims: Sestrin 2 is associated with the pathophysiology of several diseases. The aim of this study was to investigate the effects and potential mechanisms of Sestrin 2 in rat hepatic stellate cells (HSCs) during liver fibrogenesis. Methods: In this study, Sestrin 2 protein expression was detected in rat HSC-T6 cells challenged with transforming growth factor-β (TGF-β) and in mice treated with carbon tetrachloride (CCl4), a well-known model of hepatic fibrosis. Next, HSC-T6 cells and fibrotic mice were transfected with lentivirus. The mRNA expression levels of markers of liver fibrosis [alpha-smooth muscle actin (α-SMA) and collagen 1A1 (Col1A1)] were analyzed by quantitative reverse transcription–polymerase chain reaction (RT-PCR). Cell death and proliferation were evaluated by the MTT assay, and biochemical markers of liver damage in serum [alanine transaminase (ALT) and aspartate transaminase (AST)] were also measured using a biochemical analyzer. Histopathological examination was used to evaluate the degree of liver fibrosis, and protein expression [phospho-adenosine monophosphate-activated protein kinase (p-AMPK), AMPK, phospho-mammalian target of rapamycin (p-mTOR), and mTOR] was determined by western blotting. Results: We found that Sestrin 2 was elevated in both the HSC-T6 cell and hepatic fibrosis models. In vitro, overexpression of Sestrin 2 attenuated the mRNA levels of α-SMA and Col1A1, suppressed α-SMA protein expression, and modulated HSC-T6 cell proliferation. In vivo, overexpression of Sestrin 2 reduced the ALT and AST levels as well as the α-SMA and Col1A1 protein expression in the CCl4 model of liver fibrosis. Moreover, the degree of liver fibrosis was ameliorated. Interestingly, overexpression of Sestrin 2 increased p-AMPK but decreased p-mTOR protein expression. Conclusion: Our findings indicate that Sestrin 2 may attenuate the activation of HSCs and ameliorate liver fibrosis, most likely via upregulation of AMPK phosphorylation and suppression of the mTOR signaling pathway.


2020 ◽  
Vol 18 (1) ◽  
Author(s):  
Xin-Yi Xu ◽  
Yan Du ◽  
Xue Liu ◽  
Yilin Ren ◽  
Yingying Dong ◽  
...  

Abstract Background Hepatic fibrosis is a pathological response of the liver to a variety of chronic stimuli. Hepatic stellate cells (HSCs) are the major source of myofibroblasts in the liver. Follistatin like 1 (Fstl1) is a secreted glycoprotein induced by transforming growth factor-β1 (TGF-β1). However, the precise functions and regulation mechanisms of Fstl1 in liver fibrogenesis remains unclear. Methods Hepatic stellate cell (HSC) line LX-2 stimulated by TGF-β1, primary culture of mouse HSCs and a model of liver fibrosis induced by CCl4 in mice was used to assess the effect of Fstl1 in vitro and in vivo. Results Here, we found that Fstl1 was significantly up regulated in human and mouse fibrotic livers, as well as activated HSCs. Haplodeficiency of Fstl1 or blockage of Fstl1 with a neutralizing antibody 22B6 attenuated CCl4-induced liver fibrosis in vivo. Fstl1 modulates TGF-β1 classic Samd2 and non-classic JNK signaling pathways. Knockdown of Fstl1 in HSCs significantly ameliorated cell activation, cell migration, chemokines C-C Motif Chemokine Ligand 2 (CCL2) and C-X-C Motif Chemokine Ligand 8 (CXCL8) secretion and extracellular matrix (ECM) production, and also modulated microRNA-29a (miR29a) expression. Furthermore, we identified that Fstl1 was a target gene of miR29a. And TGF-β1 induction of Fstl1 expression was partially through down regulation of miR29a in HSCs. Conclusions Our data suggests TGF-β1-miR29a-Fstl1 regulatory circuit plays a key role in regulation the HSC activation and ECM production, and targeting Fstl1 may be a strategy for the treatment of liver fibrosis. Graphical abstract


2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Haowen Qiao ◽  
Yu Zhou ◽  
Xingping Qin ◽  
Jing Cheng ◽  
Yun He ◽  
...  

Background. Bone marrow-derived mesenchymal stem cells (BMSCs) have blossomed into an effective approach with great potential for the treatment of liver fibrosis. The aim of this study was to investigate the underlying antifibrosis mechanisms by which the BMSC inhibit activated hepatic stellate cells (HSCs) in vivo and in vitro. Methods. To study the effect of human bone marrow-derived mesenchymal stem cells (hBM-MSCs) on activated HSCs, we used HSCs and the coculture systems to evaluate the inhibition of activated HSCs from the aspects of the apoptosis of activated HSCs. In addition, activation of NADPH oxidase pathway and the changes in liver histopathology were tested by using the carbon tetrachloride- (CCl4-) induced liver fibrosis in mice. Results. Introduction of hBM-MSCs significantly inhibited the proliferation of activated HSCs by inducing the apoptosis process of activated HSCs. The effect of hBM-MSCs reduced the signaling pathway of NADPH oxidase in activated HSCs. Besides, the signaling pathway of NADPH oxidase mediated hBM-MSC upregulation of the expression of the peroxisome proliferator-activated receptor γ and downregulation of the expression of α1(I) collagen and alpha-smooth muscle actin (α-SMA) in activated HSCs. Moreover, the hBM-MSC-induced decrease in the signaling pathway of NADPH oxidase was accompanied by the decrease of the activated HSC number and liver fibrosis in a mouse model of CCl4-induced liver fibrosis. Conclusion. The hBM-MSCs act as a promising drug source against liver fibrosis development with respect to hepatopathy as a therapeutic target.


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.


2015 ◽  
Vol 2015 ◽  
pp. 1-19 ◽  
Author(s):  
Nouf M. Al-Rasheed ◽  
Hala A. Attia ◽  
Raeesa A. Mohamad ◽  
Nawal M. Al-Rasheed ◽  
Maha A. Al-Amin ◽  
...  

Previous data indicated the protective effect of date fruit extract on oxidative damage in rat liver. However, the hepatoprotective effects via other mechanisms have not been investigated. This study was performed to evaluate the antifibrotic effect of date flesh extract (DFE) or date pits extract (DPE) via inactivation of hepatic stellate cells (HSCs), reducing the levels of inflammatory, fibrotic and angiogenic markers. Coffee was used as reference hepatoprotective agent. Liver fibrosis was induced by injection of CCl4(0.4 mL/kg) three times weekly for 8 weeks. DFE, DPE (6 mL/kg), coffee (300 mg/kg), and combination of coffee + DFE and coffee + DPE were given to CCl4-intoxicated rats daily for 8 weeks. DFE, DPE, and their combination with coffee attenuated the elevated levels of inflammatory cytokines including tumor necrosis factor-α, interleukin-6, and interleukin-1β. The increased levels of transforming growth factor-β1 and collagen deposition in injured liver were alleviated by both extracts. CCl4-induced expression ofα-smooth muscle actin was suppressed indicating HSCs inactivation. Increased angiogenesis was ameliorated as revealed by reduced levels and expression of vascular endothelial growth factor and CD31. We concluded that DFE or DPE could protect liver via different mechanisms. The combination of coffee with DFE or DPE may enhance its antifibrotic effects.


2012 ◽  
Vol 302 (4) ◽  
pp. G439-G446 ◽  
Author(s):  
Joy X. Jiang ◽  
Xiangling Chen ◽  
Daniel K. Hsu ◽  
Kornelia Baghy ◽  
Nobuko Serizawa ◽  
...  

Hepatic stellate cells (HSC), the key fibrogenic cells of the liver, transdifferentiate into myofibroblasts upon phagocytosis of apoptotic hepatocytes. Galectin-3, a β-galactoside-binding lectin, is a regulator of the phagocytic process. In this study, our aim was to study the mechanism by which extracellular galectin-3 modulates HSC phagocytosis and activation. The role of galectin-3 in engulfment was evaluated by phagocytosis and integrin binding assays in primary HSC. Galectin-3 expression was studied by real-time PCR and enzyme-linked immunosorbent assay, and in vivo studies were done in wild-type and galectin-3−/− mice. We found that HSC from galectin-3−/− mice displayed decreased phagocytic activity, expression of transforming growth factor-β1, and procollagen α1(I). Recombinant galectin-3 reversed this defect, suggesting that extracellular galectin-3 is required for HSC activation. Galectin-3 facilitated the αvβ3 heterodimer-dependent binding, indicating that galectin-3 modulates HSC phagocytosis via cross-linking this integrin and enhancing the tethering of apoptotic cells. Blocking integrin αvβ3 resulted in decreased phagocytosis. Galectin-3 expression and release were induced in active HSC engulfing apoptotic cells, and this was mediated by the nuclear factor-κB signaling. The upregulation of galectin-3 in active HSC was further confirmed in vivo in bile duct-ligated (BDL) rats. Galectin-3−/− mice displayed significantly decreased fibrosis, with reduced expression of α-smooth muscle actin and procollagen α1(I) following BDL. In summary, extracellular galectin-3 plays a key role in liver fibrosis by mediating HSC phagocytosis, activation, and subsequent autocrine and paracrine signaling by a feedforward mechanism.


Author(s):  
Qi Yan ◽  
Linxin Pan ◽  
Shunli Qi ◽  
Fang Liu ◽  
Zhen Wang ◽  
...  

The therapeutic approach of liver fibrosis is still an unsolved clinical problem worldwide. Notably, the accumulation of extracellular matrix (ECM) in the liver is mediated by the production of cytokines and growth factors, such as transforming growth factor-β1 (TGF-β1) in hepatic stellate cells (HSCs). Ring finger protein 2 (RNF2) was identified as the catalytic subunit of polycomb repressive complex 1 (PRC1), mediating the monoubiquitination of histone H2A. In recent years, a growing amount of evidence suggests that RNF2 may play an important role in multiple pathological processes involved in cancer. Here, we explored the role of RNF2 in liver fibrogenesis and its potential mechanisms. The results showed that RNF2 was up-regulated in human fibrotic liver tissue. Knockdown of RNF2 led to a decreasing expression of collagen1 and α-smooth muscle actin (α-SMA) in LX-2 cells, which was upregulated by RNF2 overexpression. Moreover, RNF2 overexpression significantly promoted TGF-β1-induced LX-2 cell proliferation but decreased apoptosis. Furthermore, knockdown of RNF2 inhibited the activation of ERK/p38 signaling pathways induced by TGF-β1. These data suggested that RNF2 is an effective pro-fibrogenic factor for HSC activation via ERK/p38 signaling pathway. RNF2 inhibition might be a promising therapeutic target for liver fibrosis.


2020 ◽  
Vol 40 (3) ◽  
Author(s):  
Jianjian Zhao ◽  
Yueping Jiang ◽  
Xueguo Sun ◽  
Xishuang Liu ◽  
Fuguo Liu ◽  
...  

Abstract Background: The activation of hepatic stellate cells (HSCs) plays a central role in liver fibrosis. α-ketoglutarate is a natural metabolite and previous studies have shown that increase in intracellular α-ketoglutarate can inhibit HSC activation. Aim: The aim of the present study is to determine the changes and role of intracellular α-ketoglutarate in HSC activation and clarify its mechanism of action. Methods: A human HSC cell line (LX-2) and the primary mouse HSC were used in the present study. We detected the changes of intracellular α-ketoglutarate levels and the expression of enzymes involved in the metabolic processes during HSC activation. We used siRNA to determine the role of intracellular α-ketoglutarate in HSC activation and elucidate the mechanism of the metabolic changes. Results: Our results demonstrated that intracellular α-ketoglutarate levels decreased with an HSC cell line and primary mouse HSC activation, as well as the expression of isocitrate dehydrogenase 2 (IDH2), an enzyme that catalyzes the production of α-ketoglutarate. In addition, knockdown of IDH2 efficiently promoted the activation of HSCs, which was able to be reversed by introduction of an α-ketoglutarate analogue. Furthermore, we demonstrated that α-ketoglutarate regulated HSC activation is independent of transforming growth factor-β1 (TGF-β1). Conclusions: Our findings demonstrated that decrease in IDH2 expression limits the production of α-ketoglutarate during HSC activation and in turn promotes the activation of HSCs through a TGF-β1 independent pathway. The present study suggests that IDH2 and α-ketoglutarate may be potential new targets for the prevention and treatment of liver fibrosis.


2011 ◽  
Vol 301 (5) ◽  
pp. G846-G855 ◽  
Author(s):  
Ana María González ◽  
Tània Garcia ◽  
Esther Samper ◽  
Mariana Rickmann ◽  
Eva Cristina Vaquero ◽  
...  

Tocotrienols exhibit anti-inflammatory properties over macrophages and promote cytotoxicity in activated pancreatic stellate cells, suggesting that they may limit chronic pancreatitis progression. We aimed to quantitate the effect of oral tocotrienols on a rat model of chronic pancreatic injury. Chronic-like pancreatitis was induced by repeated arginine pancreatitis. Palm oil tocotrienol-rich fraction (TRF) was given by gavage before and after pancreatitis inductions. Amylase and hydroxyproline were determined in pancreatic homogenates; collagen, fibronectin, α-smooth muscle actin (SMA), glial fibrillary acidic protein (GFAP), and phosphorylated Smad3 were assessed by Western blotting. Transforming growth factor (TGF)-β1 was measured in plasma. Morphological assessment included light microscopy, fibrosis area fraction, and collagen network fractal analysis. Arginine pancreatitis induced pancreatic atrophy and increased hydroxyproline that ameliorated after TRF. Arginine increased TGF-β1 (185 ± 40 vs. 15 ± 2 ng/ml; P <0.01) that was blunted by TRF (53 ± 19; P < 0.01). TRF reduced protease and Smad3 activation, collagen, and fibronectin. α-SMA increased and GFAP diminished in arginine pancreatitis, consistent with long-term stellate cell activation, and TRF reverted these changes to basal. Arginine pancreatitis increased fibrosis area fraction (4.5 ± 0.3% vs. 0.2 ± 0.2%), collagen network complexity (fractal dimension 1.52 ± 0.03 vs. 1.42 ± 0.01; P < 0.001), and inhomogeneity (lacunarity 0.63 ± 0.03 vs. 0.40 ± 0.02; P < 0.001), which were all reduced by TRF (1.3 ± 0.4%, 1.43 ± 0.02%, and 0.51 ± 0.03%, respectively; P < 0.01). Best correlation coefficients were obtained when comparing fibrosis area fraction with lacunarity ( r = 0.88) and both parameters with pancreatic weight ( r = −0.91 and −0.79, respectively). TRF administered only before pancreatitis best, but not fully, recapitulated the beneficial effects of TRF. Tocotrienols improve quantitative measures of chronic pancreatic damage. They may be of benefit in human chronic pancreatitis.


2016 ◽  
Vol 94 (7) ◽  
pp. 779-787 ◽  
Author(s):  
Hazem Abd-Elgawad ◽  
Nashwa Abu-Elsaad ◽  
Amr El-Karef ◽  
Tarek Ibrahim

Piceatannol is a polyphenolic analog of resveratrol that selectively inhibits the non-receptor tyrosine kinase-Syk. This study investigates the potential ability of piceatannol to attenuate liver fibrosis and protect hepatocytes from injury. Thioacetamide was injected in adult male mice (100 mg/kg, i.p., 3 times/week) for 8 weeks. Piceatannol (1 or 5 mg/kg per day) was administered by oral gavage during the last 4 weeks. Liver function biomarkers, tissue malondialdehyde (MDA), cytokeratin-18 (CK18), hepatocyte growth factor (HGF), and interleukin-10 (IL-10) were measured. Necroinflammation, fibrosis, expression of transforming growth factor (TGF)-β1, and α-smooth muscle actin (SMA) were scored by histopathological examination and immunohistochemistry. Obtained results showed ability of piceatannol (1 mg/kg) to restore liver function and reduce inflammation. It significantly (p < 0.001) reduced MDA, CK18, TGF-β1, and α-SMA expression, and increased HGF and IL-10. It can be concluded that piceatannol at low dose can inhibit TGF-β1 induced hepatocytes apoptosis and exerts an anti-inflammatory effect attenuating fibrosis progression.


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