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.

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 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.

scholarly journals Sestrin 2 Attenuates Rat Hepatic Stellate Cell (HSC) Activation and Liver Fibrosis via an mTOR/AMPK-Dependent Mechanism

2018 ◽  
Vol 51 (5) ◽  
pp. 2111-2122 ◽  
Author(s):  
Yi-Bing Hu ◽  
Xiao-Ting Ye ◽  
Qing-Qing Zhou ◽  
Rong-Quan Fu
Keyword(s):  
Liver Fibrosis ◽  
Protein Expression ◽  
Hepatic Fibrosis ◽  
Transforming Growth Factor ◽  
Histopathological Examination ◽  
Stellate Cell ◽  
Smooth Muscle Actin ◽  
Mrna Levels ◽  
Alpha Smooth Muscle Actin

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.

scholarly journals HDAC6 inhibitor WT161 performs antitumor effect on osteosarcoma and synergistically interacts with 5-FU

2021 ◽  
Author(s):  
Jun Sun ◽  
Wei Wu ◽  
Xiaofeng Tang ◽  
Feifei Zhang ◽  
Cheng Ju ◽  
...  
Keyword(s):  
Dependent Manner ◽  
Osteosarcoma Cells ◽  
Synergistic Inhibition ◽  
Proliferative Effect ◽  
Xenograft Models ◽  
Hdac6 Inhibitor ◽  
Underlying Mechanisms ◽  
Induced Apoptosis

Background: WT161, as a selective HDAC6 inhibitor, has been shown to play anti-tumor effects on several kinds of cancers. The aim of this study is to explore the roles of WT161 in osteosarcoma and its underlying mechanisms. Methods: The anti-proliferative effect of WT161 on osteosarcoma cells was examined using MTT assay and colony formation assay. Cell apoptosis was analyzed using flow cytometer. The synergistic effect was evaluated by isobologram analysis using CompuSyn software. The osteosarcoma xenograft models were established to evaluate the anti-proliferative effect of WT161 in vivo. Results: WT161 suppressed the cell growth and induced apoptosis of osteosarcoma cells in a dose- and time-dependent manner. Mechanistically, we found that WT161 treatment obviously increased the protein level of PTEN and decreased the phosphorylation level of AKT. More importantly, WT161 show synergistic inhibition with 5-FU on osteosarcoma cells in vitro and in vivo. Conclusions: These results indicate that WT161 inhibits the growth of osteosarcoma through PTEN and has a synergistic efficiency with 5-FU.

scholarly journals Bactericidal/Permeability-Increasing Protein Preeminently Mediates Clearance of Pseudomonas aeruginosa In Vivo via CD18-Dependent Phagocytosis

2021 ◽  
Vol 12 ◽  
Author(s):  
Jomkuan Theprungsirikul ◽  
Sladjana Skopelja-Gardner ◽  
Ashley S. Burns ◽  
Rachel M. Wierzbicki ◽  
William F. C. Rigby
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Critical Role ◽  
Chronic Obstructive ◽  
Dependent Manner ◽  
Opsonic Activity ◽  
Obstructive Pulmonary Disease ◽  
Neutrophil Dysfunction ◽  
Chronic Lung Infection

Chronic Pseudomonas aeruginosa infection mysteriously occurs in the airways of patients with cystic fibrosis (CF), bronchiectasis (BE), and chronic obstructive pulmonary disease (COPD) in the absence of neutrophil dysfunction or neutropenia and is strongly associated with autoimmunity to bactericidal permeability-increasing protein (BPI). Here, we define a critical role for BPI in in vivo immunity against P. aeruginosa. Wild type and BPI-deficient (Bpi-/-) mice were infected with P. aeruginosa, and bacterial clearance, cell infiltrates, cytokine production, and in vivo phagocytosis were quantified. Bpi-/- mice exhibited a decreased ability to clear P. aeruginosa in vivo in concert with increased neutrophil counts and cytokine release. Bpi-/- neutrophils displayed decreased phagocytosis that was corrected by exogenous BPI in vitro. Exogenous BPI also enhanced clearance of P. aeruginosa in Bpi-/- mice in vivo by increasing P. aeruginosa uptake by neutrophils in a CD18-dependent manner. These data indicate that BPI plays an essential role in innate immunity against P. aeruginosa through its opsonic activity and suggest that perturbations in BPI levels or function may contribute to chronic lung infection with P. aeruginosa.

Antifibrotic effects of suramin in injured skeletal muscle after laceration

2003 ◽  
Vol 95 (2) ◽  
pp. 771-780 ◽  
Author(s):  
Yi-Sheng Chan ◽  
Yong Li ◽  
William Foster ◽  
Takashi Horaguchi ◽  
George Somogyi ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Growth Factor ◽  
Muscle Regeneration ◽  
Sports Medicine ◽  
Transforming Growth Factor ◽  
Smooth Muscle Actin ◽  
Healing Process ◽  
Muscle Injuries

Muscle injuries are very common in traumatology and sports medicine. Although muscle tissue can regenerate postinjury, the healing process is slow and often incomplete; complete recovery after skeletal muscle injury is hindered by fibrosis. Our studies have shown that decreased fibrosis could improve muscle healing. Suramin has been found to inhibit transforming growth factor (TGF)-β1 expression by competitively binding to the growth factor receptor. We conducted a series of tests to determine the antifibrotic effects of suramin on muscle laceration injuries. Our results demonstrate that suramin (50 μg/ml) can effectively decrease fibroblast proliferation and fibrotic-protein expression (α-smooth muscle actin) in vitro. In vivo, direct injection of suramin (2.5 mg) into injured murine muscle resulted in effective inhibition of muscle fibrosis and enhanced muscle regeneration, which led to efficient functional muscle recovery. These results support our hypothesis that prevention of fibrosis could enhance muscle regeneration, thereby facilitating more efficient muscle healing. This study could significantly contribute to the development of strategies to promote efficient muscle healing and functional recovery.

scholarly journals PASS-Predicted Hepatoprotective Activity ofCaesalpinia sappanin Thioacetamide-Induced Liver Fibrosis in Rats

2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Farkaad A. Kadir ◽  
Normadiah M. Kassim ◽  
Mahmood Ameen Abdulla ◽  
Behnam Kamalidehghan ◽  
Fatemeh Ahmadipour ◽  
...  
Keyword(s):  
Liver Fibrosis ◽  
Transforming Growth Factor ◽  
Antioxidant Activities ◽  
Smooth Muscle Actin ◽  
Immunohistochemical Analysis ◽  
Hepatoprotective Activity ◽  
Nuclear Antigen ◽  
Sprague Dawley ◽  
Liver Fibrogenesis

The antifibrotic effects of traditional medicinal herbCaesalpinia sappan(CS) extract on liver fibrosis induced by thioacetamide (TAA) and the expression of transforming growth factorβ1 (TGF-β1),α-smooth muscle actin (αSMA), and proliferating cell nuclear antigen (PCNA) in rats were studied. A computer-aided prediction of antioxidant and hepatoprotective activities was primarily performed with the Prediction Activity Spectra of the Substance (PASS) Program. Liver fibrosis was induced in male Sprague Dawley rats by TAA administration (0.03% w/v) in drinking water for a period of 12 weeks. Rats were divided into seven groups: control, TAA, Silymarin (SY), and CS 300 mg/kg body weight and 100 mg/kg groups. The effect of CS on liver fibrogenesis was determined by Masson’s trichrome staining, immunohistochemical analysis, and western blotting.In vivodetermination of hepatic antioxidant activities, cytochrome P450 2E1 (CYP2E1), and matrix metalloproteinases (MPPS) was employed. CS treatment had significantly increased hepatic antioxidant enzymes activity in the TAA-treated rats. Liver fibrosis was greatly alleviated in rats when treated with CS extract. CS treatment was noted to normalize the expression of TGF-β1,αSMA, PCNA, MMPs, and TIMP1 proteins. PASS-predicted plant activity could efficiently guide in selecting a promising pharmaceutical lead with high accuracy and required antioxidant and hepatoprotective properties.

scholarly journals Transcriptional factor ATF3 promotes liver fibrosis via activating hepatic stellate cells

2020 ◽  
Vol 11 (12) ◽  
Author(s):  
Zhemin Shi ◽  
Kun Zhang ◽  
Ting Chen ◽  
Yu Zhang ◽  
Xiaoxiao Du ◽  
...  
Keyword(s):  
Liver Fibrosis ◽  
Hepatic Stellate Cells ◽  
In Vitro Study ◽  
Stellate Cells ◽  
Protective Role ◽  
Activating Transcription Factor 3 ◽  
Dependent Manner ◽  
Liver Fibrogenesis

AbstractThe excessive accumulation of extracellular matrix (ECM) is a key feature of liver fibrosis and the activated hepatic stellate cells (HSCs) are the major producer of ECM proteins. However, the precise mechanisms and target molecules that are involved in liver fibrosis remain unclear. In this study, we reported that activating transcription factor 3 (ATF3) was over-expressed in mice and human fibrotic livers, in activated HSCs and injured hepatocytes (HCs). Both in vivo and in vitro study have revealed that silencing ATF3 reduced the expression of pro-fibrotic genes and inhibited the activation of HSCs, thus alleviating the extent of liver fibrosis, indicating a potential protective role of ATF3 knockdown. However, ATF3 was not involved in either the apoptosis or proliferation of HCs. In addition, our data illustrated that increased nuclear localization of ATF3 promoted the transcription of fibrogenic genes and lnc-SCARNA10, which functioned as a novel positive regulator of TGF-β signaling in liver fibrogenesis by recruiting SMAD3 to the promoter of these genes. Interestingly, further study also demonstrated that lnc-SCARNA10 promoted the expression of ATF3 in a TGF-β/SMAD3-dependent manner, revealing a TGF-β/ATF3/lnc-SCARNA10 axis that contributed to liver fibrosis by activating HSCs. Taken together, our data provide a molecular mechanism implicating induced ATF3 in liver fibrosis, suggesting that ATF3 may represent a useful target in the development of therapeutic strategies for liver fibrosis.

scholarly journals Suppression of the TGF-β pathway by a macrolide antibiotic decreases fibrotic responses by ocular fibroblasts in vitro

2020 ◽  
Vol 7 (9) ◽  
pp. 200441
Author(s):  
Thomas Stahnke ◽  
Beata Gajda-Deryło ◽  
Anselm G. Jünemann ◽  
Oliver Stachs ◽  
Katharina A. Sterenczak ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Transforming Growth Factor ◽  
Macrolide Antibiotic ◽  
Drug Repositioning ◽  
Dependent Manner ◽  
Glaucoma Filtration Surgery ◽  
Concentration Dependent Manner ◽  
Device Implantation

To elucidate and to inhibit post-surgical fibrotic processes after trabeculectomy in glaucoma therapy, we measured gene expression in a fibrotic cell culture model, based on transforming growth factor TGF-β induction in primary human tenon fibroblasts (hTFs), and used Connectivity Map (CMap) data for drug repositioning. We found that specific molecular mechanisms behind fibrosis are the upregulation of actins, the downregulation of CD34, and the upregulation of inflammatory cytokines such as IL6, IL11 and BMP6 . The macrolide antibiotic Josamycin (JM) reverses these molecular mechanisms according to data from the CMap, and we thus tested JM as an inhibitor of fibrosis. JM was first tested for its toxic effects on hTFs, where it showed no influence on cell viability, but inhibited hTF proliferation in a concentration-dependent manner. We then demonstrated that JM suppresses the synthesis of extracellular matrix (ECM) components. In hTFs stimulated with TGF-β1, JM specifically inhibited α-smooth muslce actin expression, suggesting that it inhibits the transformation of fibroblasts into fibrotic myofibroblasts. In addition, a decrease of components of the ECM such as fibronectin, which is involved in in vivo scarring, was observed. We conclude that JM may be a promising candidate for the treatment of fibrosis after glaucoma filtration surgery or drainage device implantation in vivo .

Reticulon 3-mediated Chk2/p53 activation suppresses hepatocellular carcinogenesis and is blocked by hepatitis B virus

Gut ◽  
2020 ◽  
pp. gutjnl-2020-321386
Author(s):  
Shushu Song ◽  
Yinghong Shi ◽  
Weicheng Wu ◽  
Hao Wu ◽  
Lei Chang ◽  
...  
Keyword(s):  
Cellular Proliferation ◽  
Dependent Manner ◽  
Mice Model ◽  
Calcium Dependent ◽  
B Virus ◽  
P53 Activation ◽  
Underlying Mechanisms ◽  
Induced Apoptosis

ObjectiveDysfunction of endoplasmic reticulum (ER) proteins is closely related to homeostasis disturbance and malignant transformation of hepatocellular carcinoma (HCC). Reticulons (RTN) are a family of ER-resident proteins critical for maintaining ER function. Nevertheless, the precise roles of RTN in HCC remain largely unclear. The aim of the study is to examine the effect of reticulon family member RTN3 on HCC development and explore the underlying mechanisms.DesignClinical HCC samples were collected to assess the relationship between RTN3 expression and patients’ outcome. HCC cell lines were employed to examine the effects of RTN3 on cellular proliferation, apoptosis and signal transduction in vitro. Nude mice model was used to detect the role of RTN3 in modulating tumour growth in vivo.ResultsWe found that RTN3 was highly expressed in normal hepatocytes but frequently downregulated in HCC. Low RTN3 expression predicted poor outcome in patients with HCC in TP53 gene mutation and HBV infection status-dependent manner. RTN3 restrained HCC growth and induced apoptosis by activating p53. Mechanism studies indicated that RTN3 facilitated p53 Ser392 phosphorylation via Chk2 and enhanced subsequent p53 nuclear localisation. RTN3 interacted with Chk2, recruited it to ER and promoted its activation in an ER calcium-dependent manner. Nevertheless, the tumour suppressive effects of RTN3 were abrogated in HBV-positive cells. HBV surface antigen competed with Chk2 for RTN3 binding and blocked RTN3-mediated Chk2/p53 activation.ConclusionThe findings suggest that RTN3 functions as a novel suppressor of HCC by activating Chk2/p53 pathway and provide more clues to better understand the oncogenic effects of HBV.

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