Attenuation of CCl4-induced hepatic fibrosis by GdCl3treatment or dietary glycine

2001 ◽  
Vol 281 (1) ◽  
pp. G200-G207 ◽  
Author(s):  
C. A. Rivera ◽  
B. U. Bradford ◽  
K. J. Hunt ◽  
Y. Adachi ◽  
L. W. Schrum ◽  
...  
Keyword(s):  
Kupffer Cell ◽  
Kupffer Cells ◽  
Cell Activation ◽  
Transforming Growth Factor ◽  
Stellate Cell ◽  
Smooth Muscle Actin ◽  
Protein Levels ◽  
Male Wistar Rats

The role of Kupffer cells in CCl4-induced fibrosis was investigated in vivo. Male Wistar rats were treated with phenobarbital and CCl4for 9 wk, and a group of rats were injected with the Kupffer cell toxicant gadolinium chloride (GdCl3) or were fed glycine, which inactivates Kupffer cells. After CCl4alone, the fibrosis score was 3.0 ± 0.1 and collagen protein and mRNA expression were elevated, but GdCl3or glycine blunted these parameters. Glycine did not alter cytochrome P-450 2E1, making it unlikely that glycine affects CCl4metabolism. Treatment with GdCl3or glycine prevented CCl4-induced increases in transforming growth factor (TGF)-β1 protein levels and expression. CCl4treatment increased α-smooth muscle actin staining (score 3.0 ± 0.2), whereas treatment with GdCl3and glycine during CCl4exposure blocked this effect (1.2 ± 0.5); there was no staining with glycine treatment. These results support previous in vitro data and demonstrate that treatment of rats with the selective Kupffer cell toxicant GdCl3prevents stellate cell activation and the development of fibrosis.

scholarly journals CD8+ T cells regulate liver injury in obesity-related nonalcoholic fatty liver disease

2020 ◽  
Vol 318 (2) ◽  
pp. G211-G224
Author(s):  
Denitra A. Breuer ◽  
Maria Cristina Pacheco ◽  
M. Kay Washington ◽  
Stephanie A. Montgomery ◽  
Alyssa H. Hasty ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Activation ◽  
Stellate Cell ◽  
Human Subjects ◽  
Smooth Muscle Actin ◽  
Nonalcoholic Fatty Liver ◽  
Novel Approach

Nonalcoholic steatohepatitis (NASH) has increased in Western countries due to the prevalence of obesity. Current interests are aimed at identifying the type and function of immune cells that infiltrate the liver and key factors responsible for mediating their recruitment and activation in NASH. We investigated the function and phenotype of CD8+ T cells under obese and nonobese NASH conditions. We found an elevation in CD8 staining in livers from obese human subjects with NASH and cirrhosis that positively correlated with α-smooth muscle actin, a marker of hepatic stellate cell (HSC) activation. CD8+ T cells were elevated 3.5-fold in the livers of obese and hyperlipidemic NASH mice compared with obese hepatic steatosis mice. Isolated hepatic CD8+ T cells from these mice expressed a cytotoxic IL-10-expressing phenotype, and depletion of CD8+ T cells led to significant reductions in hepatic inflammation, HSC activation, and macrophage accumulation. Furthermore, hepatic CD8+ T cells from obese and hyperlipidemic NASH mice activated HSCs in vitro and in vivo. Interestingly, in the lean NASH mouse model, depletion and knockdown of CD8+ T cells did not impact liver inflammation or HSC activation. We demonstrated that under obese/hyperlipidemia conditions, CD8+ T cell are key regulators of the progression of NASH, while under nonobese conditions they play a minimal role in driving the disease. Thus, therapies targeting CD8+ T cells may be a novel approach for treatment of obesity-associated NASH. NEW & NOTEWORTHY Our study demonstrates that CD8+ T cells are the primary hepatic T cell population, are elevated in obese models of NASH, and directly activate hepatic stellate cells. In contrast, we find CD8+ T cells from lean NASH models do not regulate NASH-associated inflammation or stellate cell activation. Thus, for the first time to our knowledge, we demonstrate that hepatic CD8+ T cells are key players in obesity-associated NASH.

scholarly journals Targeting Follistatin like 1 ameliorates liver fibrosis induced by carbon tetrachloride through TGF-β1-miR29a in mice

2020 ◽  
Vol 18 (1) ◽  
Author(s):  
Xin-Yi Xu ◽  
Yan Du ◽  
Xue Liu ◽  
Yilin Ren ◽  
Yingying Dong ◽  
...  
Keyword(s):  
Liver Fibrosis ◽  
Cell Activation ◽  
Transforming Growth Factor ◽  
Stellate Cell ◽  
Neutralizing Antibody ◽  
Transforming Growth Factor Β1 ◽  
Chemokine Ligand ◽  
Tgf Β1

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

scholarly journals The antioxidant (−)-epigallocatechin-3-gallate inhibits activated hepatic stellate cell growth and suppresses acetaldehyde-induced gene expression

2002 ◽  
Vol 368 (3) ◽  
pp. 695-704 ◽  
Author(s):  
Anping CHEN ◽  
Li ZHANG ◽  
Jianye XU ◽  
Jun TANG
Keyword(s):  
Transforming Growth Factor ◽  
Stellate Cell ◽  
Present Report ◽  
Smooth Muscle Actin ◽  
Critical Role ◽  
Dependent Manner ◽  
Liver Fibrogenesis ◽  
Underlying Mechanisms

Activated hepatic stellate cells (HSC) are the primary source of excessive production of extracellular matrix during liver fibrogenesis. Although the underlying mechanisms remain incompletely understood, it is widely accepted that oxidative stress plays a critical role in liver fibrogenesis. Suppression of HSC growth and activation, as well as induction of apoptosis, have been proposed as therapeutic strategies for treatment and prevention of this disease. In the present report, we elucidated, for the first time, effects of the antioxidant (—)-epigallocatechin-3-gallate (EGCG), a major (and the most active) component of green tea extracts, on cultured HSC growth and activation. Our results revealed that EGCG significantly inhibited cultured HSC growth by inducing cell cycle arrest and apoptosis in a dose- and time-dependent manner. In addition, EGCG markedly suppressed the activation of cultured HSC as demonstrated by blocking transforming growth factor-β signal transduction and by inhibiting the expression of α1(I) collagen, fibronectin and α-smooth muscle actin genes induced by acetaldehyde, the most active metabolite of ethanol. Furthermore, EGCG reacted differently in the inhibition of nuclear factor-κB activity between cultured HSC with or without acetaldehyde stimulation. Taken together, our results indicated that EGCG was a novel and effective inhibitor for activated HSC growth and activation in vitro. Further studies are necessary to evaluate the effect of this polyphenol in prevention of quiescent HSC activation in vivo, and to further elucidate the underlying mechanisms.

scholarly journals Metformin Attenuates Silica-Induced Pulmonary Fibrosis by Activating Autophagy via the AMPK-mTOR Signaling Pathway

2021 ◽  
Vol 12 ◽  
Author(s):  
Shu-xian Li ◽  
Chao Li ◽  
Xin-ru Pang ◽  
Juan Zhang ◽  
Gong-chang Yu ◽  
...  
Keyword(s):  
Pulmonary Fibrosis ◽  
Transforming Growth Factor ◽  
Smooth Muscle Actin ◽  
Mammalian Target Of Rapamycin ◽  
Specific Treatment ◽  
Transforming Growth Factor Β1 ◽  
Silica Particles ◽  
Protein Levels

Long-term exposure to crystalline silica particles leads to silicosis characterized by persistent inflammation and progressive fibrosis in the lung. So far, there is no specific treatment to cure the disease other than supportive care. In this study, we examined the effects of metformin, a prescribed drug for type || diabetes on silicosis and explored the possible mechanisms in an established rat silicosis model in vivo, and an in vitro co-cultured model containing human macrophages cells (THP-1) and human bronchial epithelial cells (HBEC). Our results showed that metformin significantly alleviated the inflammation and fibrosis of lung tissues of rats exposed to silica particles. Metformin significantly reduced silica particle-induced inflammatory cytokines including transforming growth factor-β1 (TGF-β1), tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) in rat lung tissue and HBEC culture supernatant. The protein levels of Vimentin and α-smooth muscle actin (α-SMA) were significantly decreased by metfomin while expression level of E-cadherin (E-Cad) increased. Besides, metformin increased the expression levels of phosphorylated adenosine 5′-monophosphate (AMP)-activated protein kinase (p-AMPK), microtubule-associated protein (MAP) light chain 3B (LC3B) and Beclin1 proteins, and reduced levels of phosphorylated mammalian target of rapamycin (p-mTOR) and p62 proteins in vivo and in vitro. These results suggest that metformin could inhibit silica-induced pulmonary fibrosis by activating autophagy through the AMPK-mTOR pathway.

scholarly journals BMP2 inhibits TGF-β-induced pancreatic stellate cell activation and extracellular matrix formation

2013 ◽  
Vol 304 (9) ◽  
pp. G804-G813 ◽  
Author(s):  
Xuxia Gao ◽  
Yanna Cao ◽  
Wenli Yang ◽  
Chaojun Duan ◽  
Judith F. Aronson ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Cell Activation ◽  
Transforming Growth Factor ◽  
Stellate Cell ◽  
Smooth Muscle Actin ◽  
Stellate Cells ◽  
Pancreatic Stellate Cells ◽  
Steady Increase ◽  
Pathological Feature

Activation of pancreatic stellate cells (PSCs) by transforming growth factor (TGF)-β is the key step in the development of pancreatic fibrosis, a common pathological feature of chronic pancreatitis (CP). Bone morphogenetic proteins (BMPs), members of the TGF-β superfamily, have anti-fibrogenic functions, in contrast to TGF-β, in the kidney, lung, and liver. However, it is not known whether BMPs have an anti-fibrogenic role in the pancreas. The current study was designed to investigate the potential anti-fibrogenic role of BMPs in the pancreas using an in vivo CP model and an in vitro PSC model. CP was induced by repetitive intraperitoneal injections of cerulein in adult Swiss Webster mice. The control mice received saline injections. Compared with the control, cerulein injections induced a time-dependent increase in acinar injury and progression of fibrosis and a steady increase in inflammation. Cerulein injections also induced increases of the extracellular matrix (ECM) protein fibronectin and of α-smooth muscle actin (α-SMA)-positive stellate cells (PSCs). The mice receiving cerulein injections showed increased BMP2 protein levels and phosphorylated Smad1 levels up to 4 wk and then declined at 8 wk to similar levels as the control. In vitro, the isolated mouse and human PSCs were cultured and pretreated with BMP2 followed by TGF-β treatment. BMP2 pretreatment inhibited TGF-β-induced α-SMA, fibronectin, and collagen type Ia expression. Knocking down Smad1 with small-interfering RNA reversed the inhibitory effect of BMP2 on TGF-β-induced α-SMA and fibronectin expression. Thus, BMP2 opposes the fibrogenic function of TGF-β in PSCs through the Smad1 signaling pathway.

scholarly journals Galectin-3 modulates phagocytosis-induced stellate cell activation and liver fibrosis in vivo

2012 ◽  
Vol 302 (4) ◽  
pp. G439-G446 ◽  
Author(s):  
Joy X. Jiang ◽  
Xiangling Chen ◽  
Daniel K. Hsu ◽  
Kornelia Baghy ◽  
Nobuko Serizawa ◽  
...  
Keyword(s):  
Liver Fibrosis ◽  
Cell Activation ◽  
Transforming Growth Factor ◽  
Stellate Cell ◽  
Smooth Muscle Actin ◽  
In Vivo Studies ◽  
Enzyme Linked Immunosorbent Assay ◽  
Apoptotic Cells ◽  
Galectin 3

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.

scholarly journals Alleviation of Carbon-Tetrachloride-Induced Liver Injury and Fibrosis by Betaine Supplementation in Chickens

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Meng-Tsz Tsai ◽  
Ching-Yi Chen ◽  
Yu-Hui Pan ◽  
Siou-Huei Wang ◽  
Harry J. Mersmann ◽  
...  
Keyword(s):  
Carbon Tetrachloride ◽  
Liver Fibrosis ◽  
Cell Activation ◽  
Transforming Growth Factor ◽  
Stellate Cell ◽  
Food Component ◽  
Metabolic Functions ◽  
Hepatocyte Necrosis

Betaine is a food component with well-reported hepatoprotection effects. However, the effects and mechanisms of betaine on liver fibrosis development are still insufficient. Because metabolic functions of chicken and human liver is similar, we established a chicken model with carbon Tetrachloride- (CCl4-) induced fibrosis for studying antifibrotic effect of betainein vivoandin vitro. Two-week-old male chicks were supplemented with betaine (1%, w/v) in drinking water for 2 weeks prior to the initiation of CCl4treatment (i.p.) until sacrifice. Primary chicken hepatocytes were treated with CCl4and betaine to mimic thein vivosupplementation. The supplementation of betaine significantly alleviated liver fibrosis development along with the inhibition of lipid peroxidation, hepatic inflammation cytokine, and transforming growth factor-β1 expression levels. These inhibitive effects were also accompanied with the attenuation of hepatic stellate cell activation. Furthermore, ourin vitrostudies confirmed that betaine provides antioxidant capacity for attenuating the hepatocyte necrosis by CCl4. Altogether, our results highlight the antioxidant ability of betaine, which alleviates CCl4-induced fibrogenesis process along with the suppression of hepatic stellate cells activation. Since betaine is a natural compound without toxicity, we suggest betaine can be used as a potent nutritional or therapeutic factor for reducing liver fibrosis.

Disruption of crosstalk between LX-2 and liver cancer stem-like cells from MHCC97H cells by DFOG via inhibiting FOXM1

2019 ◽  
Author(s):  
A Chen ◽  
Chang Xu ◽  
Yimin Luo ◽  
Lihua Liu ◽  
Kun Song ◽  
...  
Keyword(s):  
Liver Cancer ◽  
Colony Formation ◽  
Cell Activation ◽  
Cell Transformation ◽  
Stellate Cell ◽  
Protein Levels ◽  
Forkhead Box M1 ◽  
Foxm1 Expression

Abstract Hepatic stellate cell (HSC) line LX-2 is activated by liver cancer stem-like cells (LCSLCs) and produces various cytokines that make up most of the hepatocellular carcinoma (HCC) microenvironment. The new genistein derivative, 7-difluoromethoxyl-5,4′-di-n-octylgenistein (DFOG), shows anticancer effects in multiple malignancies by controlling forkhead box M1 (FOXM1). In this study, we aimed to assess whether DFOG disrupts the crosstalk between human HSC LX-2 cells and LCSLCs. Distinct generations of MHCC97H-derived spheres were obtained with the second generation considered as LCSLCs which displayed enhanced self-renewal ability and elevated expression levels of CD133, CD44, and EpCAM proteins, as well as tumorigenicity, as revealed by colony formation assay in vitro and tumorigenicity assay in vivo. LX-2 and MHCC97H cells were co-cultured with/without DFOG (1, 5, and 10 μM, respectively) using the transwell system. FOXM1 overexpression and/or knockdown were employed for mechanistic investigations. Our results suggested that Co-CM promoted LX-2 cell transformation into liver cancer-associated HSCs. Meanwhile, FOXM1 was up-regulated and the level of hepatocyte growth factor (HGF) was increased in LX-2 cells and in the supernatant after Co-CM stimulation. Sphere and colony formation abilities in MHCC97H cells, and protein levels of CD133, CD44, and EpCAM, were also markedly elevated. DFOG dose-dependently inhibited the above effects, similar to FOXM1 knockdown in LX-2 cells. FOXM1 overexpression reversed the inhibitory effects of DFOG or FOXM1 knockdown or both on LX-2 cell activation and LCSLC feature induction in MHCC97H cells by LCSLC/LX-2 co-culture. This study demonstrated that DFOG disrupts the crosstalk between HSCs and LCSLCs to suppress LCSLC features via down-regulating FOXM1 expression and reducing HGF secretion in HSCs.

scholarly journals mTOR inhibitors potentially reduce TGF-β2-induced fibrogenic changes in trabecular meshwork cells

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Nozomi Igarashi ◽  
Megumi Honjo ◽  
Makoto Aihara
Keyword(s):  
Trabecular Meshwork ◽  
Transforming Growth Factor ◽  
Smooth Muscle Actin ◽  
Mtor Inhibitors ◽  
In Vivo Model ◽  
Type I ◽  
Fibrotic Response ◽  
Alpha Smooth Muscle Actin

AbstractWe examined the effects of mTOR inhibitors on the fibrotic response induced by transforming growth factor-beta2 (TGF-β2) in cultured human trabecular meshwork (hTM) cells. TGF-β2-induced expression of fibronectin, collagen type I, alpha 1 chain (COL1A1), and alpha-smooth muscle actin (αSMA) in hTM cells was examined in the presence or absence of mTOR inhibitors using quantitative real-time polymerase chain reaction, Western blotting, and immunohistochemistry. The migration rates of hTM cells were examined in the presence of TGF-β2 with or without mTOR inhibitors. An in vitro study showed that the expression of fibronectin, COL1A1, and αSMA was upregulated by TGF-β2 treatment of hTM cells; such upregulation was significantly suppressed by mTOR inhibitors. The inhibitors significantly reduced the migration rate of TGF-β2-stimulated hTM cells. mTOR inhibitors may usefully reduce the fibrotic response of hTM cells and we may have to explore if it is also effective in in vivo model.

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