• Journal of Animal Reproduction and Biotechnology
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• v.35 no.2
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• pp.113-118
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• 2020

Hepatic stellate cells (HSCs) play essential roles in normal and pathophysiological function in liver. In steady state, HSCs contribute to retinoid storage, immune tolerance, and extracellular matrix (ECM) homeostasis. Upon liver injury, they become activated and lead to morphological and functional changes. Studies have demonstrated that activation of HSCs by various stimuli such as toxins, microbial infection, or metabolic overload can promote the fibrotic changes in liver by production of ECM. Herein, we provide current knowledge about the basic characteristics of HSCs and the mechanism by which they are activated.

• Journal of Applied Biological Chemistry
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• v.66
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• pp.138-143
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• 2023

Liver fibrosis is caused by metabolic problems such as cholestasis, genetic problems, or viral infections. Inhibiting hepatic stellate cell (HSC) activation or inducing selective apoptosis of activated HSCs is used as a treatment strategy for liver fibrosis. It has been reported that when HSCs are activated, their apoptosis sensitivity to tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is enhanced because the expression of death receptor 5 is elevated. Finding a natural compound that can enhance the apoptotic effect of TRAIL on HSCs is a necessary strategy for liver fibrosis treatment. It was confirmed here that mangosteen-derived gartanin increased the effect of TRAIL-induced apoptosis by increasing the expression of DR5 in a p38-dependent manner in the hepatic stellate cell line LX-2. Combined treatment with gartanin and TRAIL accelerated DNA cleavage through caspase-3 activation and enhanced antifibrotic effects in LX-2 cells.

• BMB Reports
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• v.53 no.8
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• pp.425-430
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• 2020

Tumor necrosis factor-inducible gene 6 protein (TSG-6) is a cytokine secreted by mesenchymal stem cells (MSCs) and regulates MSC stemness. We previously reported that TSG-6 changes primary human hepatic stellate cells (pHSCs) into stem-like cells by activating yes-associated protein-1 (YAP-1). However, the molecular mechanism behind the reprogramming action of TSG-6 in pHSCs remains unknown. Cluster of differentiation 44 (CD44) is a transmembrane protein that has multiple functions depending on the ligand it is binding, and it is involved in various signaling pathways, including the Wnt/β-catenin pathway. Given that β-catenin influences stemness and acts downstream of CD44, we hypothesized that TSG-6 interacts with the CD44 receptor and stimulates β-catenin to activate YAP-1 during TSG-6-mediated transdifferentiation of HSCs. Immunoprecipitation assays showed the interaction of TSG-6 with CD44, and immunofluorescence staining analyses revealed the colocalization of TSG-6 and CD44 at the plasma membrane of TSG-6-treated pHSCs. In addition, TSG-6 treatment upregulated the inactive form of phosphorylated glycogen synthase kinase (GSK)-3β, which is a negative regulator of β-catenin, and promoted nuclear accumulation of active/nonphosphorylated β-catenin, eventually leading to the activation of YAP-1. However, CD44 suppression in pHSCs following CD44 siRNA treatment blocked the activation of β-catenin and YAP-1, which inhibited the transition of TSG-6-treated HSCs into stem-like cells. Therefore, these findings demonstrate that TSG-6 interacts with CD44 and activates β-catenin and YAP-1 during the conversion of TSG-6-treated pHSCs into stem-like cells, suggesting that this novel pathway is an effective therapeutic target for controlling liver disease.

• Molecules and Cells
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• v.25 no.3
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• pp.376-384
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• 2008

The glial fibrillary acidic protein (GFAP) is traditionally used as a marker for astrocytes of the brain, and more recently for the hepatic stellate cells (HSCs) of the liver. Several GFAP splice variants have been previously reported in the astrocytes of the CNS and in the non-myelinating Schwann cells of the PNS. In this study, we investigate whether GFAP splice variants are present in the HSCs and their expression as a function of HSCs activation. Furthermore, the regulation of these transcripts upon treatment with interferon gamma ($IFN-{\gamma}$) will be explored. Using semi-quan-titative RT-PCR and real-time PCR, we examine the expression and regulation of GFAP splice variants in HSCs as well as their respective half-life. We discover that most of the GFAP splice variants ($GFAP{\alpha}$, ${\beta}$, ${\delta}$, ${\varepsilon}$ and $\kappa$) found in the neural system are also expressed in quiescent and culture-activated primary HSCs. Interestingly, $GFAP{\alpha}$ is the predominant form in quiescent and culture-activated primary HSCs, while $GFAP{\beta}$, predominates in the SV40-immortalized activated HSC-T6. $GFAP{\delta}$, ${\varepsilon}$ and ${\kappa}$ have similar half-lives of 10 hours, while $GFAP{\beta}$ has a half-life of 17 hours. Treatment of HSC-T6 with $IFN-{\gamma}$ results in a significant 1.29-fold up-regulation of $GFAP{\alpha}$ whereas the level of the other transcripts remains unchanged. In summary, $GFAP{\alpha}$, ${\beta}$, ${\delta}$, ${\varepsilon}$ and $\kappa$ are present in HSCs. They are differentially regulated on the transcription level, implying a role of the 5' and 3' untranslated regions.

• Natural Product Sciences
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• v.16 no.4
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• pp.280-284
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• 2010

During liver fibrosis, hepatic stellate cells (HSCs) undergo a complex activation process characterized by increased proliferation and extracellular matrix deposition, which is the major pathological feature of hepatic cirrhosis. Therefore, suppression of HSCs activation has been proposed as therapeutic strategies for hepatic fibrosis. We tried to screen the antifibrotic activity of natural products employing HSC-T6, hepatic stellate cell lines as an in vitro assay system. In the present study, we investigated the antiproliferative activity of aerial parts and roots of Pulsatilla koreana Nakai (Ranunculaceae). Our present study shows that roots of P. koreana exerted more strong inhibitory activity compared to its aerial parts. In addition, among the fractions of the aqueous methanolic extract of P. koreana roots, both n-hexane and $CHCl_3$ fraction showed the strong inhibitory activity on HSC proliferation. Further study also demonstrated that the n-hexane and $CHCl_3$ fraction of P. koreana roots significantly inhibited the HSC proliferation in time- and concentration-related manners.

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.101.1-101.1
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• 2003

The therapeutic goal in liver fibrosis is to reverse fibrosis and selective clearance of activated hepatic stellate cells (HSCs), which playa central role in liver fibrogenesis, by apoptosis might be essential during resolution of fibrosis. Past several years we screened for natural products which mediate apoptosis in activated HSCs, and among the candidates honokiol, isolated from Magnoliae Cortex, was found to induce apoptotic death in activated rat HSCs in a dose- and time-dependent manner at the concentration between 12.5 microM and 50 microM. (omitted)

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.142.2-142.2
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• 2003

The activation of the hepatic stellate cell (HSC) is a key step in liver fibrogenesis. We investigated the changes of global gene expression during activation in hepatic stellate cells using a rat cDNA microarray with 5, 000 sequence-verified clones. We identified osteopontin (OPN), a secreted matrix protein, as one of the upregulated factors. Northern analysis showed OPN mRNA was increasingly expressed during progressive activation of cultured rat HSCs and in models of experimental liver fibrosis. (omitted)

• Korean Journal of Pharmacognosy
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• v.43 no.1
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• pp.27-31
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• 2012

This study was designed to elucidate the effects of Cirsium japonicum (CJ) extracts on hepatic stellate cells (HSCs, LX-2 cells) proliferation, which is induced by platelet-derived growth factor (PDGF) or transforming growth factor-${\beta}$ (TGF-${\beta}$). The content of total phenol, flavonoid, and silymarin derivatives was more higher in CJ-flower than in CJ-root. Consistent with these results, the LX-2 cells growth inhibition was more effective in CJ-flower extract than in CJ-root extract, the complete growth inhibition concentration was $1{\mu}g/mL$ and $50{\mu}g/mL$, respectively. These results suggest that extracts from CJ-flower can be potentially used as therapeutic substances for the regulatioin of HSCs activation.

• Herbal Formula Science
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• v.26 no.3
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• pp.183-193
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• 2018

Objectives : In Traditional Korean Medicine, Epimedium koreanum Nakai has diverse pharmacological activities to treat impotence, forgetfulness, cataract and exophthalmos. Present study investigated anti-fibrogenic effects of E. koreanum water extract (EKE) in hepatic stellate cells (HSCs). Methods : To study anti-fibrogenic effects of EKE, LX-2 cells, a human immortalized HSCs, were pre-treated with $3-300{\mu}g/mL$ of EKE, and then subsequently exposed to 5 ng/mL of transforming growth $factor-{\beta}1$ ($TGF-{\beta}1$). Expression level of ${\alpha}-smooth$ muscle actin was determined by immunoblot analysis. Phosphorylation of Smad, transactivation of Smad, and expression of plasminogen activator inhibitor-1 (PAI-1) were monitored to investigate the effect of EKE on $TGF-{\beta}1-mediated$ signaling pathway. Results : Up to $100{\mu}g/mL$, EKE did not show any cytotoxicity on LX-2 cells. Pre-treatment of EKE ($100{\mu}g/mL$) significantly inhibited ${\alpha}-smooth$ muscle actin expression induced by $TGF-{\beta}1$. In addition, EKE significantly decreased Smad2 and Smad3 phosphorylations, Smad binding element-driven luciferase activity and PAI-1 expression by $TGF-{\beta}1$. Of three flavonoid compounds found in EKE, only quercertin ($30{\mu}M$) attenuated $TGF-{\beta}1-mediated$ PAI-1 expression. Conclusion : These results suggest that EKE has an ability to suppress fibrogenic process in HSCs via inhibition of $TGF-{\beta}1/Smad$ signaling pathway.

• The Journal of Internal Korean Medicine
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• v.26 no.4
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• pp.853-863
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• 2005

Object : This study was performed to investigate the anti-fibrogenic effect of Artemisiae Capillaris Herba(ACH) on cultured rat hepatic stellate cells. Methods : Hepatic Stellate Cells were obtained from a 350gm Sprague-Dawley rat by tissue perfusion system, and the cells for the study were selected after 3 passages of culture on non-coated plastic culture dishes which enable the cells to activate, thus producing collagens in the cell media. Cells were treated with various concentrations of Artemisia Capillaris Herba(ACH) extract powder for 24 or 48 hours. After the treatment, Soluble collagen, procollagen levels and the mRNA of the procollagen type I C were measured by using assay kit and RT-PCR method. Results : Procollagen production by the hepatic stellate cells decreased after the treatment in a time-dependent dose-dependent manner. The mRNA expression decreased consistently with the volume of the secreted procollagen which indicates the herb hat inhibitory effect on fibrogenesis of the liver by regulating one of the fibrosis associated genes in transcription. Conclusion : These results suggest that ACH is beneficial in the treatment of cirrhotic patients as well as for the patients with chronic hepatitis.