• Proceedings of the Microbiological Society of Korea Conference
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• 1998.04a
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• pp.62.1-62.1
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• 1998

• The Journal of Internal Korean Medicine
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• v.25 no.1
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• pp.28-45
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• 2004

Objectives : The main purpose of this study is to evaluate the effect of Injinchunggan-tang on $TNF-{\alpha}$ signal transmission system. Materials and Methods : We analyzed the following with quantitative RT-PCR method; the effect of Injinchunggan-tang on secretion of $TNF-\alpha$ mRNA/protein and stability, the effect on gene revelation that consists of signal transmission system (TRAIL, NIK, A20, TRADD, RAIDD, RIP TNFR-I, TNFR-II, TRAF1, TRAF2, FADD), the one on activation of p38, Erk1/2 MAPK and the rate of nuclear $NF-{\kappa}B/cytosolic\;NF-{\kappa}B$ in HepG2 cell. We also analyzed the inhibitory effect of Injinchunggan-tang on the apoptosis of HepG2 cell that $TNF-{\alpha}$ induces and the $NF-{\kappa}B$ restraint effected by transfection of $I{\kappa}B{\Delta}N$ through tryphan blue exclusion assay. Results : Injinchunggan-tang prohibits revelation of $TNF-{\alpha}$ mRNA in HepG2 cell and the creation of protein. However, it has no effect on the stability of $TNF-{\alpha}$ mRNA. While it did not have any effect on the generation of TRAIL, NIK, A20, TRADD, RAIDD and RIP genes, Injinchunggan-tang reduces the revelation of TNFR-I, TNFR-II, TRAF1, TRAF2 and FADD genes. It has been confirmed that Injinchunggan-tang restraints the revelation of $TNF-{\alpha}$ mRNA that is promoted by ethanol, acetaldehyde, lipopolysaccharide, in proportion to the treatment density and time. It activated $NF-{\kappa}B$ of HepG2 cell and promoted activation of $NF-{\kappa}B$ that is occurred by $TNF-{\alpha}$. It has been observed that the restraint effect against the $TNF-{\alpha}$ inducing apoptosis is lost when it is intercepted the function of $NF-{\kappa}B$ in HepG2 cell. Conclusion: It has been confirmed that Injinchunggan-tang has restraining effect against the revelation of $TNF-{\alpha}$ and mRNA that is constituent element of TNF-a signal transmission system. It also has been revealed that it restraints the activation of p38, Erk1/2 by $TNF-{\alpha}$. Through this prohibiting effect, it is inferred that it restraints signal transmission among various cells that are related to inflammation reaction. Meanwhile, Injinchunggan-tang protects liver cell from apoptosis that is caused by $TNF-{\alpha}$, by maintaining the activating function for $NF-{\kappa}B$.

• IMMUNE NETWORK
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• v.21 no.5
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• pp.37.1-37.17
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• 2021

Hepatitis B virus X (HBx) protein has been reported as a key protein regulating the pathogenesis of HBV-induced hepatocellular carcinoma (HCC). Recent evidence has shown that HBx is implicated in the activation of autophagy in hepatic cells. Nevertheless, the precise molecular and cellular mechanism by which HBx induces autophagy is still controversial. Herein, we investigated the molecular and cellular mechanism by which HBx is involved in the TRAF6-BECN1-Bcl-2 signaling for the regulation of autophagy in response to TLR4 stimulation, therefore influencing the HCC progression. HBx interacts with BECN1 (Beclin 1) and inhibits the association of the BECN1-Bcl-2 complex, which is known to prevent the assembly of the pre-autophagosomal structure. Furthermore, HBx enhances the interaction between VPS34 and TRAF6-BECN1 complex, increases the ubiquitination of BECN1, and subsequently enhances autophagy induction in response to LPS stimulation. To verify the functional role of HBx in liver cancer progression, we utilized different HCC cell lines, HepG2, SK-Hep-1, and SNU-761. HBx-expressing HepG2 cells exhibited enhanced cell migration, invasion, and cell mobility in response to LPS stimulation compared to those of control HepG2 cells. These results were consistently observed in HBx-expressed SK-Hep-1 and HBx-expressed SNU-761 cells. Taken together, our findings suggest that HBx positively regulates the induction of autophagy through the inhibition of the BECN1-Bcl-2 complex and enhancement of the TRAF6-BECN1-VPS34 complex, leading to enhance liver cancer migration and invasion.

• IMMUNE NETWORK
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• v.2 no.3
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• pp.137-141
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• 2002

Among the members of the inhibitor of apoptosis (IAP) protein family, only Livin and survivin have been reported to have variant forms. We have found a variant form of c-IAP2 through the interaction with the X protein of HBV using the yeast two-hybrid system. In contrast to the wild-type c-IAP2, the variant form has two stretches of sequence in the RING domain that are repeated in the C-terminus that would disrupt the RING domain. We demonstrate that the variant form has an inhibitory effect on TNF-mediated $NF-{\kappa}B$ activation unlike the wild-type c-IAP2, which increases TNFmediated $NF-{\kappa}B$ activation. These results suggest that this variant form has different activities from the wild-type and the RING domain may be involved in the regulation of TNF-induced $NF-{\kappa}B$ activation.

• The Korean Journal of Physiology and Pharmacology
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• v.18 no.1
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• pp.73-78
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• 2014

Cell death and survival are tightly controlled through the highly coordinated activation/inhibition of diverse signal transduction pathways to insure normal development and physiology. Imbalance between cell death and survival often leads to autoimmune diseases and cancer. Death receptors sense extracellular signals to induce caspase-mediated apoptosis. Acting upstream of CED-3 family proteases, such as caspase-3, Bcl-2 prevents apoptosis. Using short hairpin RNAs (shRNAs), we suppressed Bcl-2 expression in Jurkat T cells, and this increased TCR-triggered AICD and enhanced TNFR gene expression. Also, knockdown of Bcl-2 in Jurkat T cells suppressed the gene expression of FLIP, TNF receptor-associated factors 3 (TRAF3) and TRAF4. Furthermore, suppressed Bcl-2 expression increased caspase-3 and diminished nuclear factor kappa B (NF-${\kappa}B$) translocation.

• Molecules and Cells
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• v.28 no.1
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• pp.49-55
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• 2009

Hepatitis delta virus (HDV) infection causes fulminant hepatitis and liver cirrhosis. To elucidate the molecular mechanism of HDV pathogenesis, we examined the effects of HDV viral proteins, the small hepatitis delta antigen (SHDAg) and the large hepatitis delta antigen (LHDAg), on $NF-{\kappa}B$ signaling pathway. In this study, we demonstrated that $TNF-{\alpha}-induced$ $NF-{\kappa}B$ transcriptional activation was increased by LHDAg but not by SHDAg in both HEK293 and Huh7 cells. Furthermore, LHDAg promoted TRAF2-induced $NF-{\kappa}B$ activation. Using coimmunoprecipitation assays, we demonstrated that both SHDAg and LHDAg interacted with TRAF2 protein. We showed that isoprenylation of LHDAg was not required for the increase of $NF-{\kappa}B$ activity. We further showed that only LHDAg but not SHDAg increased the $TNF-{\alpha}-mediated$ nuclear translocation of p65. This was accomplished by activation of $I{\kappa}B_{\alpha}$ degradation by LHDAg. Finally, we demonstrated that LHDAg augmented the COX-2 expression level in Huh7 cells. These data suggest that LHDAg modulates $NF-{\kappa}B$ signaling pathway and may contribute to HDV pathogenesis.

• Molecules and Cells
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• v.42 no.2
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• pp.151-160
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• 2019

Ultraviolet (UV) radiation of the sunlight, especially UVA and UVB, is the primary environmental cause of skin damage, including topical inflammation, premature skin aging, and skin cancer. Previous reports show that activation of nuclear $factor-{\kappa}B$ ($NF-{\kappa}B$) in human skin fibroblasts and keratinocytes after UV exposure induces the expression and release of proinflammatory cytokines, such as interleukin-1 (IL-1) and tumor necrosis $factor-{\alpha}$ ($TNF-{\alpha}$), and subsequently leads to the production of matrix metalloproteases (MMPs) and growth factor basic fibroblast growth factor (bFGF). Here, we demonstrated that TNFR2-SKEE and TNFR2-SKE, oligopeptides from TNF receptor-associated factor 2 (TRAF2)-binding site of TNF receptor 2 (TNFR2), strongly inhibited the interaction of TNFR1 as well as TNFR2 with TRAF2. In particular, TNFR2-SKE suppressed UVB- or $TNF-{\alpha}$-induced nuclear translocalization of activated $NF-{\kappa}B$ in mouse fibroblasts. It decreased the expression of bFGF, MMPs, and COX2, which were upregulated by $TNF-{\alpha}$, and increased procollagen production, which was reduced by $TNF-{\alpha}$. Furthermore, TNFR2-SKE inhibited the UVB-induced proliferation of keratinocytes and melanocytes in the mouse skin and the infiltration of immune cells into inflamed tissues. These results suggest that TNFR2-SKE may possess the clinical potency to alleviate UV-induced photoaging in human skin.

• The Korean Journal of Physiology and Pharmacology
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• v.26 no.6
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• pp.457-468
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• 2022

It has been demonstrated that APPL1 (adaptor protein, phosphotyrosine interacting with PH domain and leucine zipper 1) is involved in the regulation of several growth-related signaling pathways and thus closely associated with the development and progression of some cancers. Diallyl trisulfide (DAT), a garlic-derived bioactive compound, exerts selective cytotoxicity to various human cancer cells through interfering with pro-survival signaling pathways. However, whether and how DAT affects survival of human hepatocellular carcinoma (HCC) cells remain unclear. Herein, we tested the hypothesis of the involvement of APPL1 in DAT-induced cytotoxicity in HCC HepG2 cells. We found that Lys 63 (K63)-linked polyubiquitination of APPL1 was significantly decreased whereas phosphorylation of APPL1 at serine residues remained unchanged in DAT-treated HepG2 cells. Compared with wild-type APPL1, overexpression of APPL1 K63R mutant dramatically increased cell apoptosis and mitigated cell survival, along with a reduction of phosphorylation of STAT3, Akt, and Erk1/2. In addition, DAT administration markedly reduced protein levels of intracellular TNF receptor-associated factor 6 (TRAF6). Genetic inhibition of TRAF6 decreased K63-linked polyubiquitination of APPL1. Moreover, the cytotoxicity impacts of DAT on HepG2 cells were greatly attenuated by overexpression of wild-type APPL1. Taken together, these results suggest that APPL1 polyubiquitination probably mediates the inhibitory effects of DAT on survival of HepG2 cells by modulating STAT3, Akt, and Erk1/2 pathways.

• Journal of agriculture & life science
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• v.50 no.2
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• pp.151-160
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• 2016

Inflammatory cytokines play a major role in osteoclastogenesis, leading to the bone resorption that is frequently associated with osteoporosis. Sulforaphane, isolated from the Broccoli(Brassica oleracea var. italia) florets, inhibits the production of inflamatory cytokine. In the present study, we determined inhibitory effect of sulforaphane on Receptor activator of nuclear factor κB ligand(RANKL)-induced osteoclast formation. Sulforaphane inhibited the expression of osteoclast marker genes, such as tartrate-resistant acid phosphatase(TRAP), cathepsin K, matrix metalloproteinase 9(MMP-9), and calcitonin receptor in RANKL-induced RAW 264.7 macrophage. Also, sluforaphane inhibited the expression of osteoclast protein, such as TRAP, MMP-9, tumor necrosis factor receptor-associated factor 6(TRAF6) and transcription factor nuclease factor of activated T cells(NFAT)c1. Sulforaphane inhibited RANKL-induced activiation of nuclear factor kappaB(NF-kappaB) by suppression RANKL-mediated NF-kappaB transcriptional acitivation. We are confirmed that sulforaphane inhibits not only transcriptional activity of NF-kappaB but also expressions of the osteoclastogenesis factors(TRAP, cathepsin K, MMP-9, calcitonin, TRAF6) and trranscription factor NFATc1.

• Journal of Life Science
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• v.31 no.4
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• pp.389-399
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• 2021

This study determined the effects of Centella asiatica leaf on H₂O₂ induced cell cycle arrest, mitochondrial activity, and proinflammatory cytokine production in human dermal fibroblast (HDF) cells. We used an 80% methanol extract of C. asiatica, its ethyl acetate fraction, and asiaticoside, the major constituent of C. asiatica. The C. asiatica extract, its ethyl acetate fraction, and asiaticoside attenuated G1 cell cycle-arrest and the apoptotic effect caused by H₂O₂-induced oxidative stress. The cells treated with C. asiatica extract, its ethyl acetate fraction, and asiaticoside secreted lower levels of TNF-α and IL-6. The antioxidant effect of asiaticoside was higher than that of C. asiatica extract and its ethyl acetate fraction. Treatment with C. asiatica extract, its ethyl acetate fraction, and asiaticoside also increased the mitochondrial membrane potential and restored normal mitochondrial morphology. Following H₂O₂ stress induction, cells treated with C. asiatica extract, its ethyl acetate fraction, and asiaticoside showed increased mitochondrial oxygen consumption rates and decreases in the TLR4-MyD88-TRAF6-p65 pathway activity. These findings suggest that C. asiatica extract, its ethyl acetate fraction, and asiaticoside have antioxidant and anti-inflammatory effects, as well as the ability to control the mitochondrial activities of HDF cells.