• Korean Journal of Clinical Laboratory Science
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• v.36 no.2
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• pp.163-172
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• 2004

Mast cells (MCs) have been implicated in the pathogenesis of tissue fibrosis. However, the role of MC in the development of liver fibrosis has not been fully elucidated. Stem cell factor (SCF) is known to recruit MCs to the liver following injury as it induces mast cell proliferation, survival and differentiation from resident tissue precursors. This study examines the interaction between activated hepatic stellate cells (HSCs) and MCs in rat fibrotic liver, and SCF production by HSCs during culture in vitro. Rats were studied 4, 7, 14 and 21 days after bile duct ligation (BDL). Fibrogenesis was assessed by a measurement of collagen stained with sirius red F3B. Activated HSCs and MCs were identified by ${\alpha}$-smooth muscle actin (${\alpha}-SMA$) immunohistochemical and alcian blue staining and measured by a computerized image analysis system. SCF production was determined in rat HSC cultures using Western blotting. Mild fibrotic changes were noted in BDL rat livers as early as 4 days after induction of cholestasis. Significant expansion and organization of fibrous tissue has occurred in day 14 BDL rats which progressed to bridging fibrosis by day 21. In BDL rats, both a large number of activated HSCs and MCs were detected in portal tracts and fibrous septa. Both area of activated HSCs infiltration and density of MCs were significantly higher in all BDL group compared with Shams. In BDL rats, both areas of activated HSCs infiltration and density of MCs were no significant difference between day 4 and 7 and were significantly higher in day 14. However, the areas of activated HSCs infiltration were significantly lesser in day 21 and the densities of MCs were significantly higher in day 21 compared with day14 BDL. In BDL rats, both areas of activated HSCs infiltration and density of MCs were highly correlated with areas of fibrosis. Western blotting showed that SCF protein was consistently produced in activated HSCs by culture on plastic and freshly isolated HSCs expressed relatively little 30kD SCF compared to late primary culture activated HSCs (day 14) and passaged HSCs. These results suggest that HSCs activated in vitro produce SCF, and may play an important role in recruiting mast cells to the liver during injury and fibrosis.

• Journal of Ginseng Research
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• v.41 no.3
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• pp.392-402
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• 2017

Background: Previously, we reported that Korean Red Ginseng inhibited liver fibrosis in mice and reduced the expressions of fibrogenic genes in hepatic stellate cells (HSCs). The present study was undertaken to identify the major ginsenoside responsible for reducing the numbers of HSCs and the underlying mechanism involved. Methods: Using LX-2 cells (a human immortalized HSC line) and primary activated HSCs, MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide) assays were conducted to examine the cytotoxic effects of ginsenosides. $H_2O_2$ productions, glutathione contents, lactate dehydrogenase activities, mitochondrial membrane permeabilities, apoptotic cell subpopulations, caspase-3/-7 activities, transferase dUTP nick end labeling (TUNEL) staining, and immunoblot analysis were performed to elucidate the molecular mechanism responsible for ginsenoside-mediated cytotoxicity. Involvement of the AMP-activated protein kinase (AMPK)-related signaling pathway was examined using a chemical inhibitor and small interfering RNA (siRNA) transfection. Results and conclusion: Of the 11 ginsenosides tested, 20S-protopanaxadiol (PPD) showed the most potent cytotoxic activity in both LX-2 cells and primary activated HSCs. Oxidative stress-mediated apoptosis induced by 20S-PPD was blocked by N-acetyl-$\text\tiny L$-cysteine pretreatment. In addition, 20S-PPD concentration-dependently increased the phosphorylation of AMPK, and compound C prevented 20S-PPD-induced cytotoxicity and mitochondrial dysfunction. Moreover, 20S-PPD increased the phosphorylation of liver kinase B1 (LKB1), an upstream kinase of AMPK. Likewise, transfection of LX-2 cells with LKB1 siRNA reduced the cytotoxic effect of 20S-PPD. Thus, 20S-PPD appears to induce HSC apoptosis by activating LKB1-AMPK and to be a therapeutic candidate for the prevention or treatment of liver fibrosis.

• Journal of Ginseng Research
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• v.47 no.4
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• pp.515-523
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• 2023

Background: 20(S)-protopanaxadiol (PPD), one of the main components of ginseng, has anti-inflammatory, anti-estrogenic, and anti-tumor activities. It is known that activated hepatic stellate cells (HSCs) are the primary producers of extracellular matrix (ECM) in the liver, and the Wnt/β-catenin pathway participates in the activation of HSCs. We aimed to explore whether PPD inhibits liver fibrosis is associated with the Wnt/β-catenin pathway inactivation. Methods: The anti-fibrotic roles of PPD were examined both in vitro and in vivo. We also examined the levels of Wnt inhibitory factor 1 (WIF1), DNA methyltransferase 1 (DNMT1) and WIF1 methylation. Results: PPD obviously ameliorated liver fibrosis in carbon tetrachloride (CCl₄)-treated mice and reduced collagen deposition. PPD also suppressed the activation and proliferation of primary HSCs. Notably, PPD inhibited the Wnt/β-catenin pathway, reduced TCF activity, and increased P-β-catenin and GSK-3β levels. Interestingly, WIF1 was found to mediate the inactivation of the Wnt/β-catenin pathway in PPD-treated HSCs. WIF1 silencing suppressed the inhibitory effects of PPD on HSC activation and also restored α-SMA and type I collagen levels. The downregulation of WIF1 expression was associated with the methylation of its promoter. PPD induced WIF1 demethylation and restored WIF1 expression. Further experiments confirmed that DNMT1 overexpression blocked the effects of PPD on WIF1 expression and demethylation and enhanced HSC activation. Conclusion: PPD up-regulates WIF1 levels and impairs Wnt/β-catenin pathway activation via the downregulation of DNMT1-mediated WIF1 methylation, leading to HSC inactivation. Therefore, PPD may be a promising therapeutic drug for patients with liver fibrosis.

• The Journal of Internal Korean Medicine
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• v.29 no.2
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• pp.500-511
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• 2008

The aim of this study was to investigate the inhibitory effect of Saengangeonbitang-gasamchilgn(SGGBTGSCG) on collagen production in rat hepatic stellate cells(HSC) and on the TAA-induced chronic liver injury model in rats. Methods : 1) HSCs were treated with SGGBTGSCG extract powder(50% EtOH SGGBTGSCG, dw SGGBTGSCG). After the treatment, MTT assay, BrdU assay and procollagen assay were done. In addition, gene expressions of collagen type $1{\alpha}2$, ASMA, TIMP1, and TIMP2, all of which are known to be associated with liver fibrosis, were analyzed by RT-PCR. 2) Liver fibrosis was developed in rats by injection of TAA 3 times a week for 5 weeks. After the SGGBTGSCG-treatment, body weight, liver & spleen weight, liver function test, the complete blood cell count and the change of portal pressure were studied. Results : In MTT assay, SGGBTGSCG significantly decreased the viability of HSCs in a dose-dependent manner. In BrdU assay, SGGBTGSCG significantly inhibited the HSC proliferation in a dose-dependant manner. In procollagen assay, SGGBTGSCG decreased procollagen production by HSC. In the change of rats' liver and spleen weight, TAA+SGGBTGSCG groups showed little difference compared with TAA-only group. In the liver function test, SGGBTGSCG decreased the serum level of ALT, AST, and Alp elevated by TAA. In the complete blood cell count, SGGBTGSCG significantly decreased WBC elevated by TAA and increased RBC and Hct lowered by TAA. In the change of portal pressure, SGGBTGSCG decreased portal pressure elevated by TAA. Conclusions : These results suggest that SGGBTGSCG is beneficial in the treatment of cirrhotic patients as well as for patients with chronic hepatitis.

• Archives of Pharmacal Research
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• v.27 no.5
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• pp.512-517
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• 2004

The structural relationship of 16 asiatic acid (AA) derivatives, including AA and asiaticoside (AS) to cytotoxicity and anti-hepatofibrotic activity in HSC-T6 cells, were investigated. Cytotoxicities of AA derivatives varied from 5.5 $\mu$M to over 2000 $\mu$M of $IC_{50}$/ depending on AA functional group modifications. Substituting the hydroxyl group at the C(2) to N≡C and substituting bulky groups for dihydroxyl groups at (3), (23) of the A-ring increased the cytotoxicity, but keto group at C(11) and benzoyl ester at C(2) were greatly reduced it. Modification of the carboxylic acid group at C28 also reduced the cytotoxicity. The collagen synthesis determined by hydroxyproline content in the cells was inhibited from a maximum of 48% (Zlx-i-85 and 87) to 15% (AS) by AA derivatives. The anti-hepatofibrotic effect of these compounds might be due to the reduced expression of prolyl 4-hydroxylase $\alpha$ and $\beta$ subunits and TIMP2. However, the inhibition of collagen by asiaticoside derivatives did not show any structural-activity relationship.

• Biomolecules & Therapeutics
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• v.32 no.3
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• pp.341-348
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• 2024

Endoplasmic reticulum (ER) stress plays a crucial role in liver diseases, affecting various types of hepatic cells. While studies have focused on the link between ER stress and hepatocytes as well as hepatic stellate cells (HSCs), the precise involvement of hepatic macrophages in ER stress-induced liver injury remains poorly understood. Here, we examined the effects of ER stress on hepatic macrophages and their role in liver injury. Acute ER stress led to the accumulation and activation of hepatic macrophages, which preceded hepatocyte apoptosis. Notably, macrophage depletion mitigated liver injury induced by ER stress, underscoring their detrimental role. Mechanistic studies revealed that ER stress stimulates macrophages predominantly via the PERK signaling pathway, regardless of its canonical substrate ATF4. hnRNPA1 has been identified as a crucial mediator of PERK-driven macrophage activation, as the overexpression of hnRNPA1 effectively reduced ER stress and suppressed pro-inflammatory activation. We observed that hnRNPA1 interacts with mRNAs that encode UPR-related proteins, indicating its role in the regulation of ER stress response in macrophages. These findings illuminate the cell type-specific responses to ER stress and the significance of hepatic macrophages in ER stress-induced liver injury. Collectively, the PERK-hnRNPA1 axis has been discovered as a molecular mechanism for macrophage activation, presenting prospective therapeutic targets for inflammatory hepatic diseases such as acute liver injury.

• Korean Journal of Food Science and Technology
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• v.41 no.5
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• pp.597-601
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• 2009

Activation of hepatic stellate cells (HSCs) is known to be responsible for hepatic fibrosis and cirrhosis. When round-shape quiescent HSCs go to activation by liver injury, production of extracellular matrix is increased, and its shape becomes myofibroblast-like shape. The activated HSCs are characterized by the high rate of proliferation and the increased production of extracellular matrix. One way of the regeneration of activated HSCs is an apoptosis induction followed by removing the activated myofibroblast-like cells. The effect of extract of Terminalia chebula Retz. (TCE) on cytotoxicity was evaluated using the rat primary hepatocyte, HepG2 and T-HSC/Cl-6 by incubating these cells with TCE up to the dose of $1,000{\mu}g/mL$. At the maximum dose of TCE, no cytotoxicity was found on primary hepatocyte and HepG2, but cytotoxic effect of TCE was found on activated HSCs, and T-HSC/Cl-6 in a U-shaped dose-response manner with the highest effect at $500{\mu}g/mL$ of TCE. Finally, we confirmed the occurrence of apoptotic cell death by annexin-V/PI double staining. The population of annexin-V positive cells was increased in a dose dependent manner.

• Korean Journal of Clinical Laboratory Science
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• v.44 no.4
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• pp.229-238
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• 2012

Cyclooxygenase(COX-2) is an inducible enzyme that catalyzes the synthesis of prostaglandins (PGs) from arachidonic acid. Over-expression of COX-2 has been reported to be associated with progressive hepatic fibrosis in chronic hepatic C infection and rat liver fibrosis induced by carbon tetrachloride($CCl_4$). Recently, it is well known that mast cell products can stimulate the proliferation of hepatic stellate cells and key players in liver fibrosis. But little is known regarding their role in $CCl_4$-induced liver fibrosis in rat. Our aim was to investigate the relation between COX-2 expression and mast cells during liver fibrosis after $CCl_4$ treatment. Thirty Wistar rats were divided into five groups (non-treated 0, 2, 4, 6 and 8-week after $CCl_4$-treatment). Reverse transcription polymerase chain reaction (RT-PCR) and immunohistochemistry were used to assess the expression of ${\alpha}$-smooth muscle actin (${\alpha}$-SMA), collagen-1 and COX-2 in liver tissue from $CCl_4$-treated rats. The density of collagen and mast cells were determined using a computerized image analysis system in liver sections stained with picrosirius red and toluidine blue, respectively. The expression levels of ${\alpha}$-SMA, collagen-1 and COX-2 mRNA were significantly higher at 2 wk in $CCl_4$-treated groups than non-treated group. The number of mast cells in liver tissues increased gradually from 2 wk to 6 wk depending on the fibrosis severity but decreased abruptly at 8 wk. The significant increase of collagen-1 and ${\alpha}$-SMA mRNA expression in $CCl_4$-treated rats was continued until 6 wk while the COX-2 mRNA was significantly decreased at 8 wk. These results suggest that increased mast cells are closely associated with COX-2 over-expression during hepatic fibrogenesis of $CCl_4$-treated rats.

• Proceedings of the Korea Environmental Mutagen Society Conference
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• 2003.10a
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• pp.171-171
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• 2003

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.300.3-301
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• 2003

The activation of the hepatic stellate cell (HSC) is a key step in liver fibrogenesis. Utilizing large scale sequencing of a 3' -directed cDNA library, we investigated expression profiles of quiescent and activated rat HSCs. During the activation process, O-acetyl disialoganglioside synthase (OAcGD3S) was identified as one of the significant upregulated factors. Upregulation of OAcGD3S in cultured HSCs was confirmed by both northern and western blot analyses. (omitted)