• BMB Reports
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• v.44 no.8
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• pp.553-557
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• 2011

We previously reported that CDK2/Cyclin A can phosphorylate and activate the transcription factor NF-Y. In this study, we investigated a potential regulatory role for NF-Y in the transcription of Cyclin A and other cell cycle regulatory genes. Gel-shift assays demonstrate that NF-Y binds to CCAAT sequences in the Cyclin A promoter, as well as to those in the promoters of cell cycle G2 regulators such as CDC2, Cyclin B and CDC25C. Furthermore, expression of Cyclin A increases NF-Y's affinity for CCAAT sequences in the CDC2 promoter; however, Cyclin A's induction of CDC2 transcription is antagonized by p21, an inhibitor of CDK2/Cyclin A. These results suggest a model wherein NF-Y binds to and activates transcription from the Cyclin A promoter, increasing cellular levels of Cyclin A/CDK2 and potentiating NF-Y's capacity for transcriptional transactivation, and imply a positive feedback loop between NF-Y and Cyclin A/CDK2. Our findings are additionally indicative of a role for Cyclin A in activating Cyclin B/CDK1 through promoting NF-Y dependent transcription of Cyclin B and CDC2; NF-Y mediated crosstalk may therefore help to orchestrate cell-cycle progression.

• IMMUNE NETWORK
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• v.14 no.1
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• pp.14-20
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• 2014

CD28/T cell receptor ligation activates the NF-${\kappa}B$ signaling cascade during CD4 T cell activation. NF-${\kappa}B$ activation is required for cytokine gene expression and activated T cell survival and proliferation. Recently, many reports showed that NF-${\kappa}B$ activation is also involved in T helper (Th) cell differentiation including Th17 cell differentiation. In this review, we discuss the current literature on NF-${\kappa}B$ activation pathway and its effect on Th17 cell differentiation.

• Toxicological Research
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• v.23 no.1
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• pp.19-24
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• 2007

We demonstrate that paclitaxel, an antitumor agent derived from yew tree, inhibits LPS- and $IFN-{\gamma}$-induced NF-kB/Rel activation in RAW 264.7 cells. Previously, paclitaxel ($>10{\mu}M$) has been known to induce iNOS gene expression in macrophages. However, in the previous report we described that the pretreatment of macrophages with low concentration of paclitaxel ($0.1{\mu}M$) for 8 h inhibited LPS-induced iNOS gene expression. Pretreatment of RAW 264.7 cells with paclitaxel significantly inhibited NF-kB/Rel transcriptional activation. Electrophoretic mobility shift assay further confirmed that pretreatment of macrophages with paclitaxel inhibited NF-kB/Rel DNA binding. Taxotere, a semisynthetic analog of paclitaxel, also inhibited LPS- and $IFN-{\gamma}$-induced iNOS gene expression. Collectively, these series of experiments indicate that paclitaxel inhibits iNOS gene expression by blocking NF-kB/Rel activation.

• Journal of Food Hygiene and Safety
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• v.25 no.3
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• pp.209-214
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• 2010

Metastasis is the primary cause of from breast cancer mortality. Cell migration and invasion play important roles in neoplastic metastasis. Matrix metalloproteinase-9 (MMP-9), which degrades the extracellular matrix (ECM), plays an important role in cancer cell invasion. NF-${\kappa}B$ is transcription factor important in the regulation of MMP-9, as the promoter of MMP-9 gene contains binding sites for NF-${\kappa}B$. Brazilin, an active component of sappan wood (Caesalpinia sappan), decreases TPA-induced MMP-9 expression and invasion in MCF-7 cells. Also, brazilin suppressed NF-${\kappa}B$ activation in TPA-treated MCF-7 cells. Taken together, we demonstrated that the inhibition of TPA-induced MMP-9 expression and cell invasion by brazilin is mediated by the suppression of the NF-${\kappa}B$ pathway in MCF-7 cells. This result suggest brazilin provide a potential therapeutic app roach for the treatment of breast cancer.

• YAKHAK HOEJI
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• v.55 no.2
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• pp.154-159
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• 2011

During the search for a novel compound that can inhibit NF-${\kappa}B$ activation, 6-hydroxy-7-methoxychroman-2-carboxylic acid phenyl amide (KL-1156) was identified as a good inhibitor of NF-${\kappa}B$ activation. In the present study, we describe the synthesis of methylchroman-2-carboxylic acid N-(disubstituted)phenylamide derivatives (1 and 2 serieses). In addition, their inhibitory effects of NF-${\kappa}B$ are compared with activity of KL-1156 and SAR (structure activity relationship) are explored.

• Journal of Acupuncture Research
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• v.23 no.3
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• pp.91-102
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• 2006

목적 : 이 연구에서는 FBS에 의하여 유도되는 혈관 평활근 세포 증식에 대한 봉약침액과 Melittin의 세포 고사효과의 영향 및 작용 기전을 살펴보고자 하였다. 방법 : $I{\kappa}Ba$, p-$I{\kappa}Ba$, p-ERK1/2, p-Akt, p53, Bcl-2, Bax 및 active caspase-3는 Western blotting을, $NF-{\kappa}B$는 EMSA와 immunofluorescence staining을 이용하여 측정하였다. 결과 : 1. Melittin은 $NF-{\kappa}B$ 활성에 대하여 $I{\kappa}Ba$의 인산화를 유의하게 익제하고 $I{\kappa}Ba$를 증가시켰으며, $NF-{\kappa}B$의 DNA 결합과 $NF-{\kappa}B$ p50의 핵 내 유입을 유의하게 감소시켰다. 2. Melittin은 $NF-{\kappa}B$ 활성을 증가시키는 물질인 Akt의 인산화를 유의하게 억제하였고, ERK1/2의 인산화도 억제하였다. 3. Melittin은 세포사멸 전구 단백질인 p53, Bax 및 caspase-3의 발현을 유의하게 증가시켰고, 세포사멸억제 단백질인 Bcl-2의 발현은 감소시켰다. 결론 : 이상의 결과는 $NF-{\kappa}B$ 와 Akt 활성을 억제함으로써 혈관평활근세포 증식을 억제하는 효과가 있음을 입증한 것이며, 향후 안전성 연구를 바탕으로 혈관성형술 후 재발성협착증과 동맥경화증의 치료제로 사용될 수 있을 것으로 기대된다.

• Journal of Microbiology and Biotechnology
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• v.29 no.8
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• pp.1316-1323
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• 2019

Middle East respiratory syndrome coronavirus (MERS-CoV) is a newly emerging coronavirus which is zoonotic from bats and camels. Its infection in humans can be fatal especially in patients with preexisting conditions due to smoking and chronic obstructive pulmonary disease (COPD). Among the 25 proteins encoded by MERS-CoV, 5 accessory proteins seem to be involved in viral evasion of the host immune responses. Here we report that ORF4a, ORF4b, and ORF8b proteins, alone or in combination, effectively antagonize nuclear factor kappa B ($NF-{\kappa}B$) activation. Interestingly, the inhibition of $NF-{\kappa}B$ by MERS-CoV accessory proteins was mostly at the level of pattern recognition receptors: melanoma differentiation-associated gene 5 (MDA5). ORF4a and ORF4b additively inhibit MDA5-mediated activation of $NF-{\kappa}B$ while that of retinoic acid-inducible gene 1 (RIG-I) is largely not perturbed. Of note, ORF8b was found to be a novel antagonist of MDA5-mediated $NF-{\kappa}B$ activation. In addition, ORF8b also strongly inhibits Tank-binding kinase 1 (TBK1)-mediated induction of $NF-{\kappa}B$ signaling. Taken together, MERS-CoV accessory proteins are involved in viral escape of $NF-{\kappa}B$-mediated antiviral immune responses.

• Journal of Acupuncture Research
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• v.29 no.1
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• pp.37-45
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• 2012

목적 : 최근 NF-${\kappa}B$와 STAT3의 활성억제와 관련된 항암제 연구가 주목받고 있으며, 본 연구는 사독(蛇毒)이 세포자멸사 관련 단백질의 발현 조절을 통하여 세포자멸사를 유도하고, NF-${\kappa}B$와 STAT3의 활성억제를 유도하여 난소암 PA-1 세포의 성장을 억제하는지를 확인하고, 해당 기전을 살펴보고자 하였다. 방법 : 사독을 처리한 후 난소암 PA-1 세포의 세포자멸사의 관찰에는 DAPI, TUNEL staining assay를 시행하였고, 세포자멸사 조절단백질 및 NF-${\kappa}B$, STAT3의 활성 변동 관찰에는 western blot analysis를 시행하였다. 결과 : 1. 사독을 처리한 후 난소암 PA-1 세포에서 세포자멸사가 유도되어 암세포성장이 억제되었다. 2. 사독을 처리한 후 세포자멸사 관련 단백질 중 세포자멸사 촉진 단백질인 cleaved caspase-3, Bax의 발현은 증가되었고, 세포자멸사 억제 단백질인 Bcl-2의 발현은 감소되었다. 3. 사독을 처리한 후 난소암 PA-1 세포의 NF-${\kappa}B$와 STAT3 발현은 감소되었고, 각각의 길항제인 salicylic acid와 stattic 처리 후 NF-${\kappa}B$와 STAT3 발현은 더욱 감소되었다. 결론 : 사독은 난소암 세포의 세포자멸사 유발과, NF-${\kappa}B$와 STAT3의 활성억제를 통해 치료 효율이 높고, 내성이 적은 난소암 치료제의 개발에 도움이 될 것으로 기대된다.

• Journal of Acupuncture Research
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• v.22 no.2
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• pp.123-132
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• 2005

Melittin,cationic 26-amino acid, is the principal component of the bee venom (BV) which has been used for treatment of inflammatory disease such as arthritis rheumatism NF-kB is activated by subsequent release of inhibitory IkB via activation of a multisubunit IkB kinase (IKK). We previously found that melittin bind to the sulfhydryl group of p50, a subunit of NF-kB. Since sulfhydryl group is present in kinase domain of IKKa and IKKb, melittin could modify IKK activity by protein-protein interaction. We therefore examined effect of melittin on IKK activities in sodium nitroprusside (SNP)-stimulated synoviocyte obtained from RA patients. Melittin suppressed the SNP-induced release of IkB resulted in inhibition of DNA binding activity of NF-kB and NF-kB-dependent luciferase activity. Consistent with the inhibitory effect on NF-kB activation, IKKa and IKKb activities were also suppressed by melittin. Surface plasmon resonance analysis realized that melitin binds to IKKa $(Kd\;=\;1.34{\times}10-9M)$ and IKKb$(Kd\;=\;1.0{\times}10-9M)$. Inhibition of IKKa and IKKb resulted in reduction of the SNP-induced production of inflammatory mediators NO and PGE2 generation. The inhibitory effect of melittin on the IKKs activities, binding affinity of melittin to IKKs, and NO and PGE2 generation were blocked by addition of reducing agents dithiothreitol and glutathione. In addition, melittin did not show inhibitory effect in the transfected Synoviocytes with plasmid carrying dominant negative mutant IKKa (C178A) and IKKb (C179A). These results demonstrate that melittin directly binds to sulfhydryl group of IKKs resulting in IkBrelease, thereby inhibits activation of NF-kB and expression of genes involving in the inflammatory responses.

• Tuberculosis and Respiratory Diseases
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• v.54 no.5
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• pp.551-562
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• 2003

Background : NF-${\kappa}B$ is a characteristic transcriptional factor which has been shown to regulate production of acute inflammatory mediators and to be involved in the pathogenesis of many inflammatory lung diseases. There has been some evidence that PI3K/Akt pathway could activate NF-${\kappa}B$ in human cell lines. However, the effect of PI3K/Akt pathway on the activation of NF-${\kappa}B$ varied depending on the cell lines used in the experiments. In this study we evaluated the effect of PI3K/Akt pathway on the activation of NF-${\kappa}B$ in human respiratory epithelial cell lines. Methods : BEAS-2B, A549 and NCI-H157 cell lines were used in this experiment. To evaluate the activation of Akt activation and I${\kappa}B$ degradation, cells were analysed by western blot assay using phospho-specific Akt Ab and $I{\kappa}B$ Ab. To block PI3K/Akt pathway, cells were pretreated with wortmannin or LY294002 and transfected with dominant negative Akt (DN-Akt). For IKK activity, immune complex kinase assay was performed. To evaluate the DNA binding affinity and transcriptional activity of NF-${\kappa}B$, electrophoretic mobility shift assay (EMSA) and luciferase assay were performed, respectively. Results : In BEAS-2B, A549 and NCI-H157 cell lines, Akt was activated by TNF-$\alpha$ and insulin. Activation of Akt by insulin did not induce $I{\kappa}B{\alpha}$ degradation. Blocking of PI3K/Akt pathway via wortmannin/LY294002 or DN-Akt did not inhibit TNF-$\alpha$-induced $I{\kappa}B{\alpha}$ degradation or IKK activation. Inhibition of PI3K/Akt did not affect TNF-$\alpha$-induced NF-${\kappa}B$ activation. Overexpression of DN-Akt did not block TNF-$\alpha$-induced transcriptional activation of NF-${\kappa}B$, but wortmannin enhanced TNF-$\alpha$-induced in NF-${\kappa}B$ transcriptional activity. Conclusion : PI3K/Akt was not involved in TNF-$\alpha$-induced $I{\kappa}B{\alpha}$ degradation or transcriptional activity of NF-${\kappa}B$ in human respiratory epithelial cell lines.