• Korean Journal of Head & Neck Oncology
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• v.27 no.1
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• pp.3-11
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• 2011

Hepatocyte growth factor(HGF) and c-Met play an important role in the control of tumor growth and invasion, and they are known to be good prognostic indicators of patient outcome. Epigallocatechin-3-gallate (EGCG) has been shown to have chemopreventive and therapeutic properties by modulating multiple signal pathways regarding the control of proliferation and invasion of cells. In this study, we evaluated the role of c-Met in EGCG-induced inhibition of invasion and apoptosis in an oral cancer cell line. In KB cells where c-Met was knocked down with siRNA, we performed invasion assay and FACS with Annexin V-FITC/PT staining. In addition, we checked the change of mitochondrial membrane potential(MMP) and the generation of reactive oxygen species(ROS). EGCG-induced inhibition of invasiveness was significantly decreased after the knock-down of c-Met. EGCG-induced apoptosis, MMP change and ROS generation was also reduced in c-Met knock-ed-down KB cells. These results suggest that c-Met is involved in EGCG-induced apoptosis and inhibition of invasiveness of oral cancer cell line.

• Toxicological Research
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• v.17 no.3
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• pp.215-223
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• 2001

Cadmium is an ubiquitous toxic metal and chronic exposure to cadmium results in the accumulation of cadmium in the liver and kidneys. In contrast, acute exposure leads to damage mainly in the liver. Apoptosis induced by cadmium has been shown in many tissues in vivo and in cultured cells in vitro. However, the molecular mechanism of cadmium-induced apoptosis is not clear in hepatocyte. To investigate the induction of apoptosis in the hepatocyte, we used mouse hepatoma cell line, Hepalclc7 cells, and analysed the molecules that involved in cadmium-induced apoptosis. Cadmium induced the genomic DNA fragmentation, PARP cleavage, and activation of caspase-3 like protease. Caspase-9 cysteine protease was activated in a time-dependent manner but caspase-8 cysteine protease was not significantly activated in cadmium-treated Hepalclc7 cells. Cadmium also induced mitochondrial dysfunction including cytochrome c release from mitochondria, change oj mitochondrial membrane potential tranition, and tranlocation of Bax Protein into mitochondria. These results strong1y indicated that the signal Pathway of apoptotic death in cadmium-treated Hepalclc7 cells is modulated by caspase cascade via mitochondria.

• Proceedings of the Korea Environmental Mutagen Society Conference
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• 2002.11a
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• pp.108-114
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• 2002

• Proceedings of the Korean Society of Applied Pharmacology
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• 2002.07a
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• pp.201-201
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• 2002

• Parasites, Hosts and Diseases
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• v.62 no.1
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• pp.30-41
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• 2024

The dense granule protein of Toxoplasma gondii, inhibitor of signal transducer and activator of transcription 1 (IST) is an inhibitor of signal transducer and activator of transcription 1 (STAT1) transcriptional activity that binds to STAT1 and regulates the expression of inflammatory molecules in host cells. A sterile inflammatory liver injury in pathological acute liver failures occurs when excessive innate immune function, such as the massive release of IFN-γ and TNF-α, is activated without infection. In relation to inflammatory liver injury, we hypothesized that Toxoplasma gondii inhibitor of STAT1 transcription (TgIST) can inhibit the inflammatory response induced by activating the STAT1/IRF-1 mechanism in liver inflammation. This study used IFN-γ and TNF-α as inflammatory inducers at the cellular level of murine hepatocytes (Hepa-1c1c7) to determine whether TgIST inhibits the STAT1/IRF-1 axis. In stable cells transfected with TgIST, STAT1 expression decreased with a decrease in interferon regulatory factor (IRF)-1 levels. Furthermore, STAT1 inhibition of TgIST resulted in lower levels of NF-κB and COX2, as well as significantly lower levels of class II transactivator (CIITA), iNOS, and chemokines (CLXCL9/10/11). TgIST also significantly reduced the expression of hepatocyte proapoptotic markers (Caspase3/8/9, P53, and BAX), which are linked to sterile inflammatory liver injury. TgIST also reduced the expression of adhesion (ICAM-1 and VCAM-1) and infiltration markers of programmed death-ligand 1 (PD-L1) induced by hepatocyte and tissue damage. TgIST restored the cell apoptosis induced by IFN-γ/TNF-α stimulation. These results suggest that TgIST can inhibit STAT1-mediated inflammatory and apoptotic responses in hepatocytes stimulated with proinflammatory cytokines.

• Molecules and Cells
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• v.40 no.3
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• pp.202-210
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• 2017

The nonstructural protein 5A (NS5A) encoded by the human hepatitis C virus (HCV) RNA genome is a multifunctional phosphoprotein. To analyse the influence of NS5A on apoptosis, we established an Hep-NS5A cell line (HepG2 cells that stably express NS5A) and induced apoptosis using tumour necrosis factor $(TNF)-{\alpha}$. We utilised the MTT assay to detect cell viability, real-time quantitative polymerase chain reaction and Western blot to analyse gene and protein expression, and a luciferase reporter gene experiment to investigate the targeted regulatory relationship. Chromatin immunoprecipitation was used to identify the combination of $NF-{\kappa}B$ and miR-503. We found that overexpression of NS5A inhibited $TNF-{\alpha}$-induced hepatocellular apoptosis via regulating miR-503 expression. The cell viability of the $TNF-{\alpha}$ induced Hep-mock cells was significantly less than the viability of the $TNF-{\alpha}$ induced Hep-NS5A cells, which demonstrates that NS5A inhibited $TNF-{\alpha}$-induced HepG2 cell apoptosis. Under $TNF-{\alpha}$ treatment, miR-503 expression was decreased and cell viability and B-cell lymphoma 2 (bcl-2) expression were increased in the Hep-NS5A cells. Moreover, the luciferase reporter gene experiment verified that bcl-2 was a direct target of miR-503, NS5A inhibited $TNF{\alpha}$-induced $NF-{\kappa}B$ activation and $NF-{\kappa}B$ regulated miR-503 transcription by combining with the miR-503 promoter. After the Hep-NS5A cells were transfected with miR-503 mimics, the data indicated that the mimics could reverse $TNF-{\alpha}$-induced cell apoptosis and blc-2 expression. Collectively, our findings suggest a possible molecular mechanism that may contribute to HCV treatment in which NS5A inhibits $NF-{\kappa}B$ activation to decrease miR-503 expression and increase bcl-2 expression, which leads to a decrease in hepatocellular apoptosis.

• Yonsei Medical Journal
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• v.59 no.9
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• pp.1064-1071
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• 2018

Purpose: To explore the influence of S100 calcium binding protein A4 (S100A4) knockout (KO) on methionine-choline-deficient (MCD) diet-induced non-alcoholic fatty liver disease (NAFLD) in mice. Materials and Methods: S100A4 KO mice (n=20) and their wild-type (WT) counterparts (n=20) were randomly divided into KO/MCD, Ko/methionine-choline-sufficient (MCS), WT/MCD, and WT/MCS groups. After 8 weeks of feeding, blood lipid and liver function-related indexes were measured. HE, Oil Red O, and Masson stainings were used to observe the changes of liver histopathology. Additionally, expressions of S100A4 and proinflammatory and profibrogenic cytokines were detected by qRT-PCR and Western blot, while hepatocyte apoptosis was revealed by TUNEL staining. Results: Serum levels of aminotransferase, aspartate aminotransferase, triglyceride, and total cholesterol in mice were increased after 8-week MCD feeding, and hepatocytes performed varying balloon-like changes with increased inflammatory cell infiltration and collagen fibers; however, these effects were improved in mice of KO/MCD group. Meanwhile, total NAFLD activity scores and fibrosis were lower compared to WT+MCD group. Compared to WT/MCS group, S100A4 expression in liver tissue of WT/MCD group was enhanced. The expression of proinflammatory ($TGF-{\alpha}$, $IL-1{\beta}$, IL-6) and profibrogenic cytokines ($TGF-{\beta}1$, COL1A1, ${\alpha}-SMA$) in MCD-induced NAFLD mice were increased, as well as apoptotic index (AI). For MCD group, the expressions of proinflammatory and profibrogenic cytokines and AI in KO mice were lower than those of WT mice. Conclusion: S100A4 was detected to be upregulated in NAFLD, while S100A4 KO alleviated liver fibrosis and inflammation, in addition to inhibiting hepatocyte apoptosis.

• The Journal of Internal Korean Medicine
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• v.21 no.3
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• pp.363-368
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• 2000

Objective : This study was carried out to examine the effect of five fractions of an aqueous extract from Artemisia capillaris $T_{HUNB}$. Methods : The queous extract from Artemisia capillaris $T_{HUNB}$. was fractionized into 5 kinds of material. We observed the effect of each fractions on etoposide-induced apoptosis, cell viability, cell cycle progression and mRNA expression of apoptosis-related genes in human hepatocyte cell line HepG2. Results and Conclusions : The data shows that butanol fraction of Artemisia capillaris $T_{HUNB}$. has no relation with cell cycle, however, it inhibits apoptosis significantly and the action may be due to the suppression of Fas and Sax genes and activation of Bcl-2 gene.

• The Journal of Korean Medicine
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• v.20 no.1 s.37
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• pp.91-105
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• 1999

The effects of Yinjin and Yinjinsaryongsangagambang on a DNA damaging agent, etoposide-induced apoptosis, cell viability, cell cycle progression, and mRNA expression of apoptosis-related genes of human hepatocyte cell line HepG2 were investigated using tryphan blue exclusion assay, MTT assay, flow cytometry, immunocytometric analysis of PCNA, and quantitative RT-PCR analysis. MTT assay showed that Yinjin and Yinjinsaryongsangagambang increases cellular viability of HepG2 cells in a dosage-dependent manner. Stimulation of cell cycle progression by Yinjin or Yinjinsaryongsangagambang was detected by flow cytometric analysis of the DNA content and immunocytometric analysis of PCNA expression. A significant reduction of a DNA-damaging agent, etoposide-induced apoptosis were found in both Yinjin and Yinjinsaryongsangagambang-treated cells in dosage-dependent manner. In overall, 3-fold reduction of apoptosis was recognized in $10.0\;{\mu}g/ml$ of Yinjin or Yinjinsaryongsangagambang-treated cells compared to untreated cells. Although the difference is not significant, Yinjinsaryongsangagambang showed slightly higher effect on the inhibition of apoptosis than Yinjin. From flow cytometric analysis of apoptosis, while 39.9% of untreated cells showed etoposide-induced apoptotic cell death, only 19.6% or 17.4% of Yinjin or Yinjinsaryongsangagambang-treated cells were fond at apoptotic sub G1 phase, respectively. Interestingly, strong induction of Gadd45-mRNA was observed from Yinjin or Yinjinsaryongsangagambang-treated cells. However, no changes in expression levels of p53 and Waf1 were detected, demonstrating that induction of Gadd45 mRNA expression by Yinjin or Yinjinsaryongsangagambang occurs by p53-independent mechanism. Marked mRNA inductions of two apoptosis-inhibiting genes, Bcl-2 and Bcl- XL, were found in both Yinjin or Yinjinsaryongsangagambang-treated HepG2 cells while no changes was detected in expression levels of an apoptosis-promoting gene, Bax.

• Herbal Formula Science
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• v.23 no.2
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• pp.189-198
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• 2015

Objectives : Sparganii Rhizoma is frequently used in traditional herbal medicine for treatment of blood stasis, amenorrhea and functional dyspepsia and has been reported to exhibit anti-oxidant, anti-proliferation and anti-angiogenesis peoperties. In this study, we investigated the cytoprotective effect and underlying mechanism of Sparganii Rhizoma water extract (SRE) against oxidative stress-induced mitochondrial dysfunction and apoptosis in hepatocyte. Methods : To determine the effects of SRE on oxidative stress, we induced synergistic cytotoxicity by co-treatment of arachidonic acid (AA) and iron in the HepG2 cell, a human derived hepatocyte cell line. Results : Treatment of SRE increased relative cell viability and altered the expression levels of apoptosis-related proteins such as Bcl-xL, Bcl-2 and procaspase-3. And SRE also inhibited the mitochondrial dysfunction and excessive reactive oxygen species production induced by AA+iron. In addition, SRE activated of AMP-activated protein kinase (AMPK), a potential target for cytoprotection, by increasing the phosphorylation of AMPKα at Thr-172. Morever, SRE increased phosphorylation of acetyl-CoA carboxylase, a direct downstream target of AMPK. Conclusion : These results indicated that SRE has the ability to protect against oxidative stress-induced hepatocyte damage, which may be mediated with AMPK pathway.