• BMB Reports
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• 제48권10호
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• pp.559-564
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• 2015

We investigated the effects of mangiferin on the expression and activity of metalloproteinase (MMP)-9 and the invasion of tumor necrosis factor (TNF)-$\alpha$-stimulated human LNCaP prostate carcinoma cells. Reverse-transcription polymerase chain reaction (RT-PCR) and western blot analysis showed that mangiferin significantly reversed TNF-$\alpha$-induced mRNA and protein expression of MMP-9 expression. Zymography data confirmed that stimulation of cells with TNF-$\alpha$ significantly increased MMP-9 activity. However, mangiferin substantially reduced the TNF-$\alpha$-induced activity of MMP-9. Additionally, a matrigel invasion assay showed that mangiferin significantly reduced TNF-$\alpha$-induced invasion of LNCaP cells. Compared to untreated controls, TNF-$\alpha$-stimulated LNCaP cells showed a significant increase in nuclear factor-${\kappa}B$ (NF-${\kappa}B$) luciferase activity. However, mangiferin treatment markedly decreased TNF-$\alpha$-induced NF-${\kappa}B$ luciferase activity. Furthermore, mangiferin suppressed nuclear translocation of the NF-${\kappa}B$ subunits p65 and p50. Collectively, our results indicate that mangiferin is a potential anti-invasive agent that acts by suppressing NF-${\kappa}B$-mediated MMP-9 expression.

• BMB Reports
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• 제40권3호
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• pp.341-348
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• 2007

Herpesvirus saimiri (HVS), a member of the $\delta$-herpesvirus family, encodes an oncoprotein called Saimiri Transforming Protein (STP) which is required for lymphoma induction in non-human primates. Previous study has shown that STP-C, an oncoprotein of HVS, activates NF-$\kappa$B signaling pathway. However, the detailed mechanism of STP-Cmediated NF-$\kappa$B activation has not been reported yet. We first report that STP-C interacts with TRAF6 protein in vivo and in vitro and further investigation shows that $Glu_{12}$ residue of STP-C is critical for binding to TRAF6. Introduction of ubiquitin together with STP-C augments NF-$\kappa$B activity compared to that of STP-C expression alone. STP-C expression further induces ubiquitination of endogenous TRAF6. In addition, either a deubiquitination enzyme, CYLD or a dominant negative E2-conjugation enzyme reduced NF-$\kappa$B activity in spite of the presence of STP-C, supporting that the interaction between STP-C and TRAF6 induces ubiquitination of TRAF6. NF-$\kappa$B activation by STP-C through the ubiquitinated TRAF6 causes the increased production of IL-8, an inflammatory chemokine and the enhanced expression of costimulatory molecule ICAM, which might ultimately contribute cellular transformation by the exposure of HVS-infected cells with inflammatory microenvironment and chronic activation.

• 한방안이비인후피부과학회지
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• 제21권3호
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• pp.82-93
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• 2008

Objective: Previously, the methanol extracts of the semen of Xanthium strumsrium could involved anti-inflammatory effects in lipopolysaccharide (LPS)-stimulated Raw 264,7 cells, We evaluated the anti-allergic effects of X. strumarium on rat basophilic leukemia (RBL-2H3) cells, Methodes : To investigate the effect of X. strumarium on the phorbol 12-myristate 13-acetate (PMA) and calcium ionophore A23187-induced RBL-2H3 cells. The effects of X. strumarium on the degranulation and the pro-inflammatory cytokines secretion and expression from RBL-2H3 cells were evaluated with $\beta$-hexosaminidase assay, ELISA, and RT-PCR analysis, In addition, we examined the effects of X. strumarium on nuclear factor (NF)-${\kappa}B$ activation and $I{\kappa}B-\alpha$ degradation using Western blot analysis. Results : X. strumarium inhibited degranulation and secretions and expressions of pro-inflammatory cytokines, such as tumor necrosis factor-alpha ($TNF-\alpha$), interleukin (IL)-4 and cyclooxygenase (COX)-2, on stimulated RBL-2H3 cells, however, X. strumarium not affect cell viability. In stimulated RBL-2H3 cells, the protein expression level of nuclear factor-kappa B (NF-${\kappa}B$) was decreased in the nucleus by X. strumarium. In addition, X. strumarium suppressed the degradation of inhibitory protein $I{\kappa}B-{\alpha}$ protein in RBL-2H3 cells. Conclusion : These results suggest that X. strumarium inhibits the degranulation and secretion of pro-inflammatory cytokines through blockade of NF-${\kappa}B$ activation and I $I{\kappa}B-{\alpha}$ degradation.

• 생명과학회지
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• 제19권4호
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• pp.514-519
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• 2009

혈관벽에 단핵구, 대식세포 등의 세포와 지질 등의 축적은 중요한 동맥경화 발병 요인이다. 이들 세포의 혈관벽으로의 이동에 있어서 chemokine인 MCP1이 중요한 역할을 한다는 것이 많이 알려져 있다. 본 연구에서는 사람 평활근세포에서 $IL-1{\beta}$의 처리에 의하여 MCP1의 발현이 증가되는 기전을 알아보고자 실험을 진행하였다. $IL-1{\beta}$의 처리는 전사인자 $NF-{\kappa}B$의 활성화를 통해 MCP1 발현을 전사단계에서 증가시켰다. 이러한 $IL-1{\beta}$에 의해 증가된 MCP1 발현을 억제하는 물질을 찾기 위해 여러 항염증작용을 하는 물질들을 전처리하여 확인해 본 결과 luteolin이 선택적으로 $IL-1{\beta}$에 의해 증가된 MCP1의 발현을 전사단계에서 저해하는 것을 확인하였고 이는 전사인자 $NF-{\kappa}B$가 핵으로 이동하는 것을 감소시킴으로써 나타나는 현상임을 확인하였다. Luteolin이 염증작용을 조절하는데 있어서 중요한 전사인자인 $NF-{\kappa}B$의 활성을 조절한다는 것을 본 실험을 통해 알 수 있었고 이는 식용식물에서 일반적으로 발견되는 luteolin이 어떠한 기전으로 항 염증작용을 하는지에 대한 이해를 높여줄 것이다.

• Parasites, Hosts and Diseases
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• 제52권5호
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• pp.459-469
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• 2014

Entamoeba histolytica is a tissue-invasive protozoan parasite causing dysentery in humans. During infection of colonic tissues, amoebic trophozoites are able to kill host cells via apoptosis or necrosis, both of which trigger IL-8-mediated acute inflammatory responses. However, the signaling pathways involved in host cell death induced by E. histolytica have not yet been fully defined. In this study, we examined whether calpain plays a role in the cleavage of pro-survival transcription factors during cell death of colonic epithelial cells, induced by live E. histolytica trophozoites. Incubation with amoebic trophozoites induced activation of m-calpain in a time- and dose-dependent manner. Moreover, incubation with amoebae resulted in marked degradation of STAT proteins (STAT3 and STAT5) and NF-${\kappa}B$ (p65) in Caco-2 cells. However, $I{\kappa}B$, an inhibitor of NF-${\kappa}B$, was not cleaved in Caco-2 cells following adherence of E. histolytica. Entamoeba-induced cleavage of STAT proteins and NF-${\kappa}B$ was partially inhibited by pretreatment of cells with a cell-permeable calpain inhibitor, calpeptin. In contrast, E. histolytica did not induce cleavage of caspase-3 in Caco-2 cells. Furthermore, pretreatment of Caco-2 cells with a calpain inhibitor, calpeptin (but not the pan-caspase inhibitor, z-VAD-fmk) or m-calpain siRNA partially reduced Entamoeba-induced DNA fragmentation in Caco-2 cells. These results suggest that calpain plays an important role in E. histolytica-induced degradation of NF-${\kappa}B$ and STATs in colonic epithelial cells, which ultimately accelerates cell death.

• Journal of Chest Surgery
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• 제50권3호
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• pp.144-152
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• 2017

Background: The ubiquitin-proteasome system (UPS) is an important pathway of proteolysis in pathologic hypertrophic cardiomyocytes. We hypothesize that MG132, a proteasome inhibitor, might prevent hypertrophic cardiomyopathy (CMP) by blocking the UPS. Nuclear factor kappa-light-chain-enhancer of activated B cells ($NF-{\kappa}B$) and androgen receptor (AR) have been reported to be mediators of CMP and heart failure. This study drew upon pathophysiologic studies and the analysis of $NF-{\kappa}B$ and AR to assess the cardioprotective effects of MG132 in a left ventricular hypertrophy (LVH) rat model. Methods: We constructed a transverse aortic constriction (TAC)-induced LVH rat model with 3 groups: sham (TAC-sham, n=10), control (TAC-cont, n=10), and MG132 administration (TAC-MG132, n=10). MG-132 (0.1 mg/kg) was injected for 4 weeks in the TAC-MG132 group. Pathophysiologic evaluations were performed and the expression of AR and $NF-{\kappa}B$ was measured in the left ventricle. Results: Fibrosis was prevalent in the pathologic examination of the TAC-cont model, and it was reduced in the TAC-MG132 group, although not significantly. Less expression of AR, but not $NF-{\kappa}B$, was found in the TAC-MG132 group than in the TAC-cont group (p<0.05). Conclusion: MG-132 was found to suppress AR in the TAC-CMP model by blocking the UPS, which reduced fibrosis. However, $NF-{\kappa}B$ expression levels were not related to UPS function.

• The Korean Journal of Physiology and Pharmacology
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• 제1권5호
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• pp.515-521
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• 1997

Endothelial cells play a central role in the inflammatory processes, and activation of nuclear factor kappa B ($NF-_{\kappa}B$) is a key component in that inflammatory processes. Previously, we reported that tumor necrosis factor alpha($TNF{\alpha}$) had protective effect of cell death induced by serum deprivation and this protection was related to $NF-_{\kappa}B$ activation. Inducible nitric oxide synthase (iNOS) is a member of the molecules which transcription is regulated mainly by $NF-_{\kappa}B$. And the role of nitric oxide (NO) generated by iNOS on cell viability is still controversial. To elucidate the mechanism of $TNF{\alpha}$ and $NF-_{\kappa}B$ activation on cell death protection, we investigate the effect of NO on the cell death induced by serum- deprivation in bovine cerebral endothelial cells in this study. Addition of $TNF{\alpha}$, which are inducer of iNOS, prevented serum-deprivation induced cell death. Increased expression of iNOS was confirmed indirectly by nitrite measurement. When selective iNOS inhibitors were treated, the protective effect of $TNF{\alpha}$ on cell death was partially blocked, suggesting that iNOS expression was involved in controlling cell death. Exogenously added NO substrate (L-arginine) and NO donors (sodium nitroprusside and S-nitroso-N-acetylpenicillamine) also inhibited the cell death induced by serum deprivation. These results suggest that NO has protective effect on bovine cerebral endothelial cell death induced by serum-deprivation and that iNOS is one of the possible target molecules by which $NF-_{\kappa}B$ exerts its cytoprotective effect.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제34권1호
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• pp.28-35
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• 2008

Purpose: The nitric oxide (NO) release by inducible nitric oxide synthase (iNOS) is the key events in macrophage response to lipopolysaccharide (LPS) which is suggested to be a crucial mediator for inflammatory and innate immune responses. NO is an important mediator involved in many host defense action and may also lead to a harmful host response to bacterial infection. However, given the importance of iNOS in a variety of pathophysiological conditions, control of its expression and signaling events in response to LPS has been the subject of considerable investigation. Materials and Methods: The Raw264.7 macrophage cell line was used to observe LPS-stimulated iNOS expression. The expression of iNOS is observed by Western blot analysis and real-time RT-PCR. Protein kinase C $(PKC)-{\alpha}$ overexpressing Raw264.7 cells are established to determine the involvement of $PKC-{\alpha}$ in LPS-mediated iNOS expression. $NF-{\kappa}B$ activity is measured by $I{\kappa}B{\alpha}$ degradation and $NF-{\kappa}B$ luciferase activity assay. Results: We found that various PKC isozymes regulate LPS-induced iNOS expression at the transcriptional and translational levels. The involvement of $PKC-{\alpha}$ in LPS-mediated iNOS induction was further confirmed by increased iNOS expression in $PKC-{\alpha}$ overexpressing cells. $NF-{\kappa}B$ dependent transactivation by LPS was observed and $PKC-{\alpha}$ specific inhibitory peptide abolished this activation, indicating that $NF-{\kappa}B$ activation is dependent on $PKC-{\alpha}$. Conclusion: Our data suggests that $PKC-{\alpha}$ is involved in LPS-mediated iNOS expression and that its downstream target is $NF-{\kappa}B$. Although $PKC-{\alpha}$ is a crucial mediator in the iNOS regulation, other PKC isozymes may contribute LPS-stimulated iNOS expression. This finding is needed to be elucidated in further study.

• Archives of Pharmacal Research
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• 제23권1호
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• pp.54-58
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• 2000

To elucidate the molecular mechanisms for the suppression of LPS-induced nitric oxide (NO) production by a dehydrocostus lactone (DL) from Saussurea lappa, we examined the preventive effect of this compound on $NF-{\kappa}B$ activation in LPS-treated RAW 264.7 macrophages and U937 human monocytic cells. The results suggest that the suppression of NO production is mediated by the inhibitory action on the i-NOS gene expression through the inactivation of $NF-{\kappa}B$ and this sesquiterpene lactone can act as a pharmacological inhibitor of the $NF-{\kappa}B$ activation.

• 대한한의학회지
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• 제29권1호
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• pp.47-59
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• 2008

Objective : Anti-inflammatory effects of the extract of Lycii Fructus on lipopolysaccharide (LPS)-induced inflammation in RAW 264.7 macrophage cells were investigated. Method : In order to assess the cytotoxic effect of Lycii Fructus on the raw 264.7 macrophages 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT) assay was performed. Reverse transcription-polymerase chain reaction(RT-PCR) analysis of the mRNA levels of tumor necrosis factor-$\alpha$(TNF-$\alpha$) and inducible nitric oxide synthase(iNOS) was performed in order to provide an estimate of the relative level of expression of these genes. The protein level of the inhibitor of nuclear factor-${\kappa}B(I{\kappa}B)$ and nuclear factor-${\kappa}B$(NF-${\kappa}B$) activity was investigated by Western blot assay. NO production was investigated by NO detection. Result : Lycii Fructus suppressed NO production by inhibiting the LPS-induced expressions of iNOS and TNF-$^-\alpha$ mRNA and iNOS protein in RAW 264.7 macrophage cells. Also, Lycii Fructus suppressed activation of NF-${\kappa}B$ in the nucleus. Conclusion : These results show that the extract of Lycii Fructus has anti-inflammatory effect probably by suppressing iNOS expressions through the down-regulation of NF-${\kappa}B$ binding activity.