• 생명과학회지
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• 제20권12호
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• pp.1772-1776
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• 2010

내재면역반응의 중요한 조절자인 Nrf2와 NF-${\kappa}B$는 염증시에 교차 작용을 통하여 서로의 전사활성을 조절할 수 있다고 보고된 바 있으나 상반된 결과도 제시되고 있어서 아직까지 확실하게 규명되어 있지 않다. 저자들은 선행연구에서 NF-${\kappa}B$ 저해제인 금(I)-화합물 오라노핀이 인간 관절활막세포와 단핵구성 세포에서 Nrf2를 활성화시킴을 확인한 바 있기 때문에, 본 연구에서는 Nrf2를 knockdown 시킨 류마티스성 활막세포를 사용하여 오라노핀에 의해 저해되는 NF-${\kappa}B$ 신호전달 과정에 Nrf2가 관여하는지를 조사하였다. 세포를 Nrf2 siRNA로 transfection시켰을 때 Nrf2 발현은 대부분 차단됨을 확인하였다. 하지만 Nrf2 knockdown은 TNF-$\alpha$에 의해 유도되는 $I{\kappa}B-{\alpha}$ 분해를 막는 오라노핀의 작용에는 영향을 주지 않았다. Nrf2 target 단백질로서 항염 작용에 관여하는 HO-1을 knockdown 시켰을 경우에도 $I{\kappa}B-{\alpha}$ 분해를 저해하는 오라노핀의 작용에 영향을 미치지 않았다. 또한, Nrf2 knockdown은 오라노핀에 의해 저해된 ICAM-1 발현을 다시 복원시키지 못했다. 이러한 결과들은 염증성 싸이토킨에 의해 유도되는 NF-${\kappa}B$ 활성화를 오라노핀이 저해하는 기전에 Nrf2 및 HO-1이 관련되어 있지 않음을 시사한다. 따라서 류마티스성 관절활막세포에서 오라노핀의 항염작용 기전으로 알려진 Nrf2/HO-1 활성유도와 NF-${\kappa}B$ 활성저해는 교차작용 없이 각각 독립적인 기전을 통해 나타나는 것으로 생각된다.

• Journal of Ginseng Research
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• 제43권3호
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• pp.452-459
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• 2019

Background: Ginsenoside compound K(C-K), a major metabolite of ginsenoside, exhibits anticancer activity in various cancer cells and animal models. A cell signaling study has shown that C-K inhibited nuclear factor-kappa B ($NF-{\kappa}B$) pathway in human astroglial cells and liver cancer cells. However, the molecular targets of C-K and the initiating events were not elucidated. Methods: Interaction between C-K and Annexin A2 was determined by molecular docking and thermal shift assay. HepG2 cells were treated with C-K, followed by a luciferase reporter assay for $NF-{\kappa}B$, immunofluorescence imaging for the subcellular localization of Annexin A2 and $NF-{\kappa}B$ p50 subunit, coimmunoprecipitation of Annexin A2 and $NF-{\kappa}B$ p50 subunit, and both cell viability assay and plate clone formation assay to determine the cell viability. Results: Both molecular docking and thermal shift assay positively confirmed the interaction between Annexin A2 and C-K. This interaction prevented the interaction between Annexin A2 and $NF-{\kappa}B$ p50 subunit and their nuclear colocalization, which attenuated the activation of $NF-{\kappa}B$ and the expression of its downstream genes, followed by the activation of caspase 9 and 3. In addition, the overexpression of Annexin A2-K320A, a C-K binding-deficient mutant of Annexin A2, rendered cells to resist C-K treatment, indicating that C-K exerts its cytotoxic activity mainly by targeting Annexin A2. Conclusion: This study for the first time revealed a cellular target of C-K and the molecular mechanism for its anticancer activity.

• The Korean Journal of Physiology and Pharmacology
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• 제7권4호
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• pp.199-205
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• 2003

Osteoblasts are affected by TNF-${\alpha}$ overproduction by immune cells during inflammation. It has been suggested that functional $NF-{\kappa}B$ sites are involved in TNF-${\alpha}$-induced bone resorption. Thus, we explored the effect of pyrrolidine dithiocarbamate (PDTC), which potently blocks the activation of nuclear factor $(NF-{\kappa}B)$, on the induction of TNF-${\alpha}$-induced activation of JNK/SAPK, AP-1, cytochrome c, caspase and apoptosis in MC3T3E1 osteoblasts. Pretreatment of the cells with PDTC blocked TNF-${\alpha}$-induced $NF-{\kappa}B$ activation. TNF-${\alpha}$-induced activation of AP-1, another nuclear transcription factor, was suppressed by PDTC. The activation of c-Jun N-terminal kinase, implicated in the regulation of AP-1, was also down regulated by PDTC. TNF-${\alpha}$-induced apoptosis, release of cytochrome c and subsequent activation of caspase-3 were abolished by PDTC. TNF-${\alpha}$-induced apoptosis was partially blocked by Ac-DEVD-CHO, a caspase-3 inhibitor, suggesting that caspase-3 is involved in TNF-${\alpha}$-mediated signaling through $NF-{\kappa}B$ in MC3T3E1 osteoblasts. Thus, these results demonstrate that PDTC, has an inhibitory effect on TNF-${\alpha}$-mediated activation of JNK/SAPK, AP-1, cytochrome c release and subsequent caspase-3, leading to the inhibition of apoptosis. Our study may contribute to the treatment of TNF-${\alpha}$-associated immune and inflammatory diseases such as rheumatoid arthritis and periodontal diseases.

• The Korean Journal of Physiology and Pharmacology
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• 제21권4호
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• pp.449-456
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• 2017

Beauvericin (BEA), a cyclic hexadepsipeptide produced by the fungus Beauveria bassiana, is known to have anti-cancer, anti-inflammatory, and anti-microbial actions. However, how BEA suppresses macrophage-induced inflammatory responses has not been fully elucidated. In this study, we explored the anti-inflammatory properties of BEA and the underlying molecular mechanisms using lipopolysaccharide (LPS)-treated macrophage-like RAW264.7 cells. Levels of nitric oxide (NO), mRNA levels of transcription factors and the inflammatory genes inducible NO synthase (iNOS) and interleukin (IL)-1, and protein levels of activated intracellular signaling molecules were determined by Griess assay, semi-quantitative reverse transcriptase-polymerase chain reaction (RT-PCR), luciferase reporter gene assay, and immunoblotting analysis. BEA dose-dependently blocked the production of NO in LPS-treated RAW264.7 cells without inducing cell cytotoxicity. BEA also prevented LPS-triggered morphological changes. This compound significantly inhibited nuclear translocation of the $NF-{\kappa}B$ subunits p65 and p50. Luciferase reporter gene assays demonstrated that BEA suppresses MyD88-dependent NF-${\kappa}B$ activation. By analyzing upstream signaling events for $NF-{\kappa}B$ activation and overexpressing Src and Syk, these two enzymes were revealed to be targets of BEA. Together, these results suggest that BEA suppresses $NF-{\kappa}B$-dependent inflammatory responses by suppressing both Src and Syk.

• Journal of Nutrition and Health
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• 제50권1호
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• pp.25-31
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• 2017

퇴행성 뇌신경 질환의 원인이 되는 것으로 알려진 미세아교세포의 과도한 활성화에 의한 신경염증반응에 미치는 미역쇠의 보호 효과를 알아보기 위해 LPS를 처리한 BV2 세포에서 미역쇠에서 얻은 에탄올 추출물을 이용하여 실험을 수행하였다. 미세아교세포의 활성화를 유도하는 LPS의 처리는 신경염증반응의 지표인 NO의 생성량과 이들을 조절하는 iNOS, COX-2의 발현을 증가시켰다. 미역쇠 추출물의 처리는 LPS가 유도하는 NO의 생성량을 농도 의존적으로 억제하였고 iNOS와 COX-2의 발현을 억제하여 NO 생성량 저해와 유사한 양상의 결과를 나타내었다. 미역쇠 추출물의 신경 염증반응 저해 효과가 $NF-{\kappa}B$의 활성화 조절을 통해 일어나는지를 알아보기 위해 $NF-{\kappa}B$의 핵으로의 전이, $I{\kappa}B$의 인산화, $NF-{\kappa}B$ 억제제인 PDTC를 이용한 NO의 생성량에 미치는 효과를 확인하였다. 미역쇠 추출물 처리에 의해 핵분획물에서의 $NF-{\kappa}B$ 발현은 현저히 감소하였고 $I{\kappa}B$의 인산화를 억제하였으며 PDTC의 처리로 NO의 생성량은 감소하였다. 이상의 결과는 미세아교세포의 활성화로 인해 발생되는 신경염증반응에 미역쇠 추출물이 $NF-{\kappa}B$의 활성 억제를 통해 NO의 생성을 저해함으로써 항신경염증 효과가 있음을 보여주는 것으로 미역쇠 추출물이 신경염증 관련 뇌신경 질환의 제어하는데 있어서 치료효과를 가지는 소재로서 이용 가능성에 대한 정보를 제공할 것으로 사료된다.

• Tuberculosis and Respiratory Diseases
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• 제48권5호
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• pp.682-698
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• 2000

Glucocorticoid receptor (GR) functions as a suppressor of inflammation by inhibiting the expression of many cytokine genes activated by NF-${\kappa}B$. The goal of this study is to investigate the mechanism by which GR repress NF-${\kappa}B$ activation in lung epithelial cells. We used A549 and BEAS-2B lung epithelia! cell lines. Using Ig$G{\kappa}$-NF-${\kappa}B$ luciferase reporter gene construct, we found that dexamethasone significantly suppressed TNF-$\alpha$-induced NF-${\kappa}B$ activation and the overexpression of GR showed dose-dependent reduction of TNF-$\alpha$-induced NF-${\kappa}B$ activity in both cell lines. However, DNA binding of NF-${\kappa}B$ induced by TNF-$\alpha$ in electromobility shift assay was not inhibited by dexamethasone. Super shift assay with anti-p65 antibody demonstrated the existence of p65 in NF-${\kappa}B$ complex induced by $\alpha$ Western blot showed that $I{\kappa}B{\alpha}$ degradation induced by TNF-$\alpha$ was not affected by dexamethasone and $I{\kappa}B{\kappa}$ was not induced by dexamethasone, neither. To evaluate p65 specific transactivation, we adopted co-transfection study of Gal4-p65TA1 or TA2 fusion protein expression system together with 5xGal4-luciferase vector. Co-transfection of GR with Gal4-p65TA1 or TA2 repressed luciferase activity profoundly to the level of 10-20% of p65TA1- or TA2-induced transcriptional activity. And this transrepressional effect was abolished by co-transfection of CBP of SRC-1 expression vectors. These results suggest that GR-mediated transrepression of NF-${\kappa}B$ in lung epithelial cells is through competing for binding to limiting amounts of transcriptional coactivators, CBP or SRC-1.

• 약학회지
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• 제52권1호
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• pp.62-66
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• 2008

In this study, we examined the inhibitory effects of propenone derivatives, 1,3-diphenyl-propenone (DPhP), 3-phenyl-1-thiophen-2-yl-propenone (PhT2P), 3-phenyl-1-thiophen-3-yl-propenone (PhT3P) and 1-furan-2-yl-3-phenyl-propenone (FPhP), on $TNF-{\alpha}$-induced nuclear factor (NF)-${\kappa}B$ activity and interleukin (IL)-8-induced monocyte adhesion to colon epithelial cells. 1-Furan-2-yl-3-pyridin-2-yl-propenone (FPP-3) that is previously reported as a $NF-{\kappa}B$ inhibitor suppressed $TNF-{\alpha}$-induced monocyte-epithelial cell adhesion in a concentration-dependent manner. The propenone derivatives, DPhP, PhT2P, PhT3P, FPhP, also inhibited $TNF-{\alpha}$-induced $NF-{\kappa}B$ activation in a similar degree to FPP-3. In a DPPH radical scavenging assay, none of the compounds showed DPPH radical scavenging activity, indicating that the inhibitory actions of the propenone derivatives on redox-sensitive $NF-{\kappa}B$ activity is not due to a simple free radical scavenging activity. In addition, the propenone derivatives also suppressed the IL-8-induced monocyte adhesion to colon epithelial cells. Furthermore, the effective concentrations of the propenone derivatives on both $NF-{\kappa}B$ activation as well as IL-8 induced monocyte-epithelial cell adhesion were 1000 times lower than 5-aminosalicylic acid (5-ASA), a clinically used drug for inflammatory bowel disease. These results suggest that the propenone derivatives may be a potential lead having a strong inhibitory activity against inflammatory cytokine-induced epithelial inflammation.

• 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.

• BMB Reports
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• 제38권3호
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• pp.281-289
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• 2005

Tumor necrosis factor (TNF) signaling is mediated via two distinct receptors, TNFR2 and TNFR1, which shows partially overlapping signaling mechanisms and biological roles. In the present study, TNFR2 and TNFR1 signal transduction mechanisms involved in activation of $NF{\kappa}B$ and CMV promoter-enhancer were compared with respect to their susceptibility towards inhibitors of intracellular signaling. For this, we used SW480 cells, where we have shown that TNF-signaling can occur independently through each of the two receptors. The TNFR1 response was inhibited by D609, bromophenacyl bromide (BPB), nordihydroguararetic acid (NDGA), and by sodium salicylate, while TNFR2-mediated activation of $NF{\kappa}B$ and CMV promoter-enhancer was resistant to these compounds. The signaling mechanisms known to be affected by these inhibitors include phospholipases as well as redox- and pH-sensitive intracellular components. Our results imply that TNFR2 signaling involved in $NF{\kappa}B$ activation proceeds independently of these inhibitor-sensitive signaling components, indicating distinct signaling pathways not shared with TNFR1.

• Tuberculosis and Respiratory Diseases
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• 제52권6호
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• pp.616-626
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• 2002

연구배경 : PM2.5는 호흡기질환의 악화 및 호흡기 질환에 의한 사망률과 밀접하게 관계가 있다. PM2.5에 의한 호흡기 염증반응의 악화가 그 원인으로 생각되나 염증반응의 조절기전은 확실하지 않다. 본연구에서는 PM2.5에 의한 폐장의 염증반응을 조절하는데 중요한 역할을 하는 전사인자인 $NF{\kappa}B$의 활성화 기전을 알아보아 염증 조절기전에 대한 이해를 높이고자 시도되었다. 방 법 : 폐상피세포주인 A549 세포에서 PM2.5 자극에 의한 $NF{\kappa}B$의 활성화 및 ROS, 그리고 RNS 분비를 관찰 하였다. iNOS 억제제인 L-NIL가 $NF{\kappa}B$ 활성화에 미치는 영향을 관찰하였다. 결 과 : PM2.5는 A549 세포에서 $NF{\kappa}B$의 활성화를 유도 하였다. PM2.5로 A549 세포를 자극시 즉각적인 RNS의 분비는 관찰되었으나 명확한 ROS의 증가는 관찰되지 않았다. RNS 억제제인 L-NIL 처리시 $NF{\kappa}B$ 활성화는 억제되었다. 결 론 : A549 세포에서 PM2.5에 의하여 유도된 즉각적인 $NF{\kappa}B$ 활성화 과정에는 RNS가 중요한 역할을 할 것으로 생각된다.