• Molecules and Cells
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• 제27권2호
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• pp.211-215
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• 2009

Toll-like receptors (TLRs) play a critical role in sensing microbial components and inducing innate immune and inflammatory responses by recognizing invading microbial pathogens. Lipopolysaccharide-induced dimerization of TLR4 is required for the activation of downstream signaling pathways including nuclear factor-kappa B ($NF-{\kappa}B$). Therefore, TLR4 dimerization may be an early regulatory event in activating ligand-induced signaling pathways and induction of subsequent immune responses. Here, we report biochemical evidence that 6-shogaol, the most bioactive component of ginger, inhibits lipopolysaccharide-induced dimerization of TLR4 resulting in the inhibition of $NF-{\kappa}B$ activation and the expression of cyclooxygenase-2. Furthermore, we demonstrate that 6-shogaol can directly inhibit TLR-mediated signaling pathways at the receptor level. These results suggest that 6-shogaol can modulate TLR-mediated inflammatory responses, which may influence the risk of chronic inflammatory diseases.

• International Journal of Oral Biology
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• 제42권4호
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• pp.149-153
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• 2017

Cyclooxygenase-2 (COX-2)-mediated prostaglandin $E_2$ ($PGE_2$) plays a key role in development and progression of inflammatory responses and Porphyromonas gingivalis is a common endodontic pathogen. In this study, we investigated induction of COX-2 and $PGE_2$ by P. gingivalis in human dental pulp cells (HDPCs). P. gingivalis increased expression of COX-2, but not that of COX-1. Increased levels of $PGE_2$ were released from P. gingivalis-infected HDPCs and this $PGE_2$ increase was blocked by celecoxib, a selective COX-2 inhibitor. P. gingivalis activated all three types of mitogen-activated protein kinases (MAPKs). P. gingivalis-induced activation of nuclear $factor-{\kappa}B$ ($NF-{\kappa}B$) was demonstrated by the results of phosphorylation of $NF-{\kappa}B$ p65 and degradation of inhibitor of ${\kappa}B-{\alpha}$ ($I{\kappa}B-{\alpha}$). Pharmacological inhibition of each of the three types of MAPKs and $NF-{\kappa}B$ substantially attenuated P. gingivalis-induced $PGE_2$ production. These results suggest that P. gingivalis should promote endodontic inflammation by stimulating dental pulp cells to produce $PGE_2$.

• Tuberculosis and Respiratory Diseases
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• 제75권5호
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• pp.205-209
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• 2013

Background: We investigated whether prunetin significantly affects tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$)-induced MUC5AC mucin gene expression, production, inhibitory kappa B ($I{\kappa}B$) degradation and nuclear factor kappa B (NF-kB) p65 translocation in human airway epithelial cells. Methods: Confluent NCI-H292 cells were pretreated with prunetin for 30 minutes and then stimulated with TNF-${\alpha}$ for 24 hours or the indicated periods. MUC5AC mucin gene expression and mucin protein production were measured by reverse transcription polymerase chain reaction and enzyme-linked immunosorbent assay, respectively. The effect of prunetin on TNF-${\alpha}$-induced degradation of $I{\kappa}B$ and translocation of NF-${\kappa}B$ p65 was investigated by western blot analysis. Results: We found that incubation of NCI-H292 cells with prunetin significantly inhibited mucin production and down-regulated the MUC5AC gene expression induced by TNF-${\alpha}$. Prunetin inhibited TNF-${\alpha}$-induced degradation of $I{\kappa}B$ and translocation of NF-${\kappa}B$ p65. Conclusion: This result suggests that prunetin inhibits the NF-${\kappa}B$ signaling pathway, which may explain its role in the inhibition of MUC5AC mucin gene expression and production regulated by the NF-${\kappa}B$ signaling pathway.

• Tuberculosis and Respiratory Diseases
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• 제54권1호
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• pp.104-113
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• 2003

연구배경 : Rhinovirus(RV)는 상기도 감염의 중요한 원인균으로, 성인에서 기관지천식의 급성악화의 주요 원인이다. RV에 의한 기도염증반응의 기전은 잘 알려져 있지 않지만 interleukin(IL)-1, IL-6, IL-8 및 RANTES 등의 사이토카인을 매개로 일어난다. 염증반응에 관여하는 사이토카인의 발현은 적어도 전사인자 NF-${\kappa}B$에 의존성이므로 이러한 가설을 검증하기 위해 인체기도상피세포에서 RV에 의한 IL-8의 분비양상과 NF-${\kappa}B$ 활성화 단계에서 차단 제로 이용되는 N-acetyl-L-cysteine(NAC), PDTC, 및 TPCK를 투여하여 IL-8의 차단정도를 연구하여 NF-${\kappa}B$의 역할을 규명하고자 하였다. 방법 : 인체 기관지상피세포(BEAS-2B)와 RV type 14(RV14)를 ATCC로부터 구입하여 RV14 스톡을 만들고 역가를 측정하였다. 자극이 없는 대조군(배지단독)과 RV14를 상피세포에 감염시킨 후(MOI=1.0) 각각에서 2, 4, 6, 12, 24, 48 시간에 배양 상층액(SN)을 얻었다. 또한 대조군, RV14 자극군, NAC, PDTC, 및 TPCK 처치와 함께 RV14 자극을 준 군에서 각각 배양 12시간에 배양 상층액을 수집했다. SN에서 효소면역측정법으로 IL-8의 농도를 측정하였다. 결과 : 1) 상피세포는 RV14 자극이 없는 상태에서 배양시간의 경과에 따라 약간의 IL-8의 생산이 있었다. 2) 상피세포에 RV14 감염 후 4시간에서부터 IL-8이 증가하여 배양 48시간까지 지속적으로 증가하였다. 3) NAC와 PDTC는 RV14에 의한 IL-8의 생산을 유의하게 감소시켰으나, TPCK는 RV에 의한 IL-8의 생산을 억제하였지만 통계학적으로 유의하지 않았다. 4) NAC와 PDTC는 RV에 의한 IL-8 생성을 용량 의존적으로 억제하였다. 결론 : 일부 항산화제가 RV에 의한 기도염증반응을 차단할 수 있는 가능성을 제시하며 추후 NF-${\kappa}B$ 활성화 경로의 차단 부위에 대한 연구가 필요할 것으로 생각한다.

• Asian Pacific Journal of Cancer Prevention
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• 제15권16호
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• pp.6911-6917
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• 2014

Background: Hepatocellular carcinoma is a complex and heterogeneous tumor with poor prognosis due to frequent intrahepatic spread and extrahepatic metastasis. The molecular mechanisms underlying HCC pathogenesis still remain obscure. Objectives: We aimed to investigate the abundance and the DNA binding activity of nuclear factor kappa B/p65 subunit in peripheral blood mononuclear cells from patients with HCC and to assess its prognostic significance and association with hypoxia inducible factor one alpha (HIF-$1{\alpha}$) in blood. Subjects and methods: This study was carried out on 40 patients classified equally into liver cirrhosis (group I) and HCC (group II), in addition to 20 healthy volunteers (group III). All groups were subjected to measurement of NF-${\kappa}B$/P65 subunit expression levels by real time-PCR, and DNA binding activity was evaluated by transcription factor binding immunoassay. Serum HIF-$1{\alpha}$ levels were estimated by enzyme-linked immunosorbent assay (ELISA). Significant increase of both the expression level and DNA binding activity of NF-${\kappa}B$/P65 subunit together with serum HIF-1 alpha levels was noted in HCC patients compared to liver cirrhosis and control subjects, with significant positive correlation with parameters for bad prognosis of HCC. In conclusion, NF-${\kappa}B$ signaling is activated in HCC and associated with disease prognosis and with high circulating levels of HIF-1 alpha.

• Bulletin of the Korean Chemical Society
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• 제32권12호
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• pp.4397-4402
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• 2011

The NF-${\kappa}B$ system of transcription factors plays a crucial role in inflammatory diseases, making it an important drug target. We combined quantitative structure activity relationships for predicting the activity of new compounds and quantitative dynamic models for the NF-${\kappa}B$ network with intracellular concentration models. GFA-MLR QSAR analysis was employed to determine the optimal QSAR equation. To validate the predictability of the $IKK{\beta}$ QSAR model for an external set of inhibitors, a set of ordinary differential equations and mass action kinetics were used for modeling the NF-${\kappa}B$ dynamic system. The reaction parameters were obtained from previously reported research. In the IKKb QSAR model, good cross-validated $q^2$ (0.782) and conventional $r^2$ (0.808) values demonstrated the correlation between the descriptors and each of their activities and reliably predicted the $IKK{\beta}$ activities. Using a developed simulation model of the NF-${\kappa}B$ signaling pathway, we demonstrated differences in $I{\kappa}B$ mRNA expression between normal and different inhibitory states. When the inhibition efficiency increased, inhibitor 1 (PS-1145) led to long-term oscillations. The combined computational modeling and NF-${\kappa}B$ dynamic simulations can be used to understand the inhibition mechanisms and thereby result in the design of mechanism-based inhibitors.

• 대한의생명과학회지
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• 제18권4호
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• pp.345-354
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• 2012

Angelica keiskei has exhibited numerous pharmacological effects including antitumor, antimetastatic, and antidiabetic effects. However, the anti-inflammatory effects and mechanisms employed by xanthoangelol E isolated from Angelica keiskei are incompletely understood. In this study, we attempted to determine the effects of Xanthoangelol E on the lipopolysaccharide (LPS)-stimulated mouse peritoneal macrophage. The findings of this study demonstrated that xanthoangelol E inhibited the production of tumor necrosis factor (TNF)-${\alpha}$, interleukin (IL)-6, and prostaglandin $E_2$ ($PGE_2$). Xanthoangelol E inhibited the enhanced levels of cyclooxygenase (COX)-2 and inducible nitric oxide synthase (iNOS) caused by LPS. Additionally, we showed that the anti-inflammatory effect of xanthoangelol E is through the regulation of the activation of nuclear factor (NF)-${\kappa}B$ and caspase-1. These results provide novel insights into the pharmacological actions of xanthoangelol E as a potential candidate for the development of new drugs to treat inflammatory diseases.

• The Korean Journal of Physiology and Pharmacology
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• 제20권1호
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• pp.91-99
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• 2016

(E)-3-(3-methoxyphenyl)-1-(2-pyrrolyl)-2-propenone (MPP) is an aldol condensation product resulting from pyrrole-2-carbaldehyde and m- and p- substituted acetophenones. However, its biological activity has not yet been evaluated. Since it has been reported that some propenone-type compounds display anti-inflammatory activity, we investigated whether MPP could negatively modulate inflammatory responses. To do this, we employed lipopolysaccharide (LPS)-stimulated macrophage-like RAW264.7 cells and examined the inhibitory levels of nitric oxide (NO) production and transcriptional activation, as well as the target proteins involved in the inflammatory signaling cascade. Interestingly, MPP was found to reduce the production of NO in LPS-treated RAW264.7 cells, without causing cytotoxicity. Moreover, this compound suppressed the mRNA levels of inflammatory genes, such as inducible NO synthase (iNOS) and tumor necrosis factor (TNF)-${\alpha}$. Using luciferase reporter gene assays performed in HEK293 cells and immunoblotting analysis with nuclear protein fractions, we determined that MPP reduced the transcriptional activation of nuclear factor (NF)-${\kappa}B$. Furthermore, the activation of a series of upstream signals for NF-${\kappa}B$ activation, composed of Src, Syk, Akt, and $I{\kappa}B{\alpha}$, were also blocked by this compound. It was confirmed that MPP was able to suppress autophosphorylation of overexpressed Src and Syk in HEK293 cells. Therefore, these results suggest that MPP can function as an anti-inflammatory drug with NF-${\kappa}B$ inhibitory properties via the suppression of Src and Syk.

• 대한한의학회지
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• 제25권3호
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• pp.90-98
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• 2004

Objectives : The present study was undertaken to investigate the molecular mechanisms of Ichungwhan for inhibition of cyclooxygenase-2 (COX-2) gene expression via suppression of NF-κB (nuclear factor κB) using aged rats. NF-κB is the most important modulator of inflammation and NF-κB regulates the gene expression of several pro-inflammatory cytokines, such as COX-2. Methods : In the experiment, we investigated the scavenging property of Ichungwhan on reactive species (RS) including nitrogen-derived species (RNS), measured by DCF-DA (2,7-dichlorodihydrofluorexcein diacetate) / DHR 123 (dihydrorhodamine 123) assay. Protein expression levels of COX-2, NF-κB, p-ERK and p-p38 were assayed by western blot. Results : We showed that Ichungwhan inhibits RS including RNS and inhibits NF-κB activation by blocking the dissociation of inhibitory IκB-β via suppression of IKK pathway. Also, Ichungwhan inhibits COX-2 gene expression. Conclusions : These findings suggest that Ichungwhan modulates COX-2 gene expression via suppression of the NF-κB pathway.

• Biomolecules & Therapeutics
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• 제23권5호
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• pp.414-420
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• 2015

Flavonoids, such as fisetin (3,7,3',4'-tetrahydroxyflavone), are plant secondary metabolites. It has been reported that fisetin is able to perform numerous pharmacological roles including anti-inflammatory, anti-microbial, and anti-cancer activities; however, the exact anti-inflammatory mechanism of fisetin is not understood. In this study, the pharmacological action modes of fisetin in lipopolysaccharide (LPS)-stimulated macrophage-like cells were elucidated by using immunoblotting analysis, kinase assays, and an overexpression strategy. Fisetin diminished the release of nitric oxide (NO) and reduced the mRNA levels of inducible NO synthase (iNOS), tumor necrosis factor (TNF)-${\alpha}$, and cyclooxygenase (COX)-2 in LPS-stimulated RAW264.7 cells without displaying cytotoxicity. This compound also blocked the nuclear translocation of p65/nuclear factor (NF)-${\kappa}B$. In agreement, the upstream phosphorylation events for NF-${\kappa}B$ activation, composed of Src, Syk, and I${\kappa}B{\alpha}$, were also reduced by fisetin. The phospho-Src level, triggered by overexpression of wild-type Src, was also inhibited by fisetin. Therefore, these results strongly suggest that fisetin can be considered a bioactive immunomodulatory compound with anti-inflammatory properties through suppression of Src and Syk activities.