• Archives of Pharmacal Research
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• 제27권10호
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• pp.1073-1079
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• 2004

Interactions of the cell adhesion molecules are known to play important roles in mediating inflammation. The proinflammatory cytokine, tumor necrosis factor-${\alpha}$(TNF-${\alpha}$), activates the NF-kB signaling pathway, which induces the expression of various genes, such as intercellular adhesion molecule-1 (ICAM-1). In this study, the effect of vitamin C on the ICAM-1 expression induced by TNF-${\alpha}$ in a human neuroblastoma cell line, SK-N-SH was investigated. Treatment with vitamin C resulted in the downregulation of the TNF-${\alpha}$-induced surface expression and ICAM-1 mRNA levels in a concentration-dependent manner. Moreover, a gel shift analysis indicated that vitamin C dose-dependently inhibited the NF-kB activation and IkB${\alpha}$ degradation induced by TNF-${\alpha}$. Taken together, these results suggest that vitamin C downregulates TNF-${\alpha}$- induced ICAM-1 expression via the inhibition of NF-kB activation.

• Archives of Pharmacal Research
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• 제25권4호
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• pp.475-479
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• 2002

Capsaicin, a major pungent constituent of red pepper (Capsicum annuum L.) possesses a vast variety of pharmacologic and physiologic activities. Despite its irritant properties, the compound exerts anti-inflammatory and anti-nociceptive effects. Previous studies from this laboratory revealed that capsaicin, when topically applied onto dorsal skin of female ICR mice, strongly attenuated activation of NF-kB and AP-1 induced by the typical tumor promoter, 12-O-tetradecanoylphorbol-13-acetate (TPA), which may account for its anti-tumor promoting activity in mouse skin. In the present work, we have found that capsaicin suppresses TPA-stimulated activation of NF-kB through inhibition of $IkB{\alpha}$ degradation and blockade of subsequent nuclear translocation of p65 in human pro myelocytic leukemia HL-60 cells. Methylation of the phenolic hydroxyl group of capsaicin abolished its inhibitory effect on NF-kB DNA binding. Likewise, TPA-induced activation of AP-1 was mitigated by capsaicin treatment.

• The Korean Journal of Physiology and Pharmacology
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• 제13권6호
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• pp.475-482
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• 2009

Rifampicin is a macrocyclic antibiotic which is used extensively for treatment against Mycobacterium tuberculosis and other mycobacterial infections. Recently, a number of studies have focused on the immune-regulatory effects of rifampicin. Therefore, we hypothesized that rifampicin may influence the TLR2 expression in LPS-activated RAW 264.7 cells. In this study, we determined that rifampicin suppresses LPS-induced TLR2 mRNA expression. The down-regulation of TLR2 expression coincided with decreased production of TNF-$\alpha$ Since NF-${\kappa}B$ is a major transcription factor that regulates genes for TLR2 and TNF-$\alpha$, we examined the effect of rifampicin on the LPS-induced NF-${\kappa}B$ activation. Rifampicin inhibited NF-${\kappa}B$ DNA-binding activity in LPS-activated RAW 264.7 cells, while it did not affect IKK$\alpha/\beta$ activity. However, rifampicin slightly inhibited the nuclear translocation of NF-${\kappa}B$ p65. In addition, rifampicin increased physical interaction between pregnane X receptor, a receptor for rifampicin, and NF-${\kappa}B$ p65, suggesting pregnane X receptor interferes with NF-${\kappa}B$ binding to DNA. Taken together, our results demonstrate that rifampicin inhibits LPS-induced TLR2 expression, at least in part, via the suppression of NF-${\kappa}B$ DNA-binding activity in RAW 264.7 cells. Thus, the present results suggest that the rifampicin-mediated inhibition of TLR2 via the suppression of NF-${\kappa}B$ DNA-binding activity may be a novel mechanism of the immune-suppressive effects of rifampicin.

• Biomolecules & Therapeutics
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• 제17권4호
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• pp.403-411
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• 2009

Thiacremonone, the main component isolated from heated garlic (Allium sativum L.), is interested for using as a cancer preventive or therapeutic agent since garlic has been known to be useful plant in the treatment of cancers. Nuclear factor kappaB (NF-${\kappa}B$) is constitutively activated in the prostate cancer and activation of NF-${\kappa}B$ is implicated in drug resistance in cancer cells. Docetaxel, a semisynthetic analog of paclitaxel, is an antineoplastic drug widely used for advanced various cancer. In previous studies, we found that thiacremonone inhibited activation of NF-${\kappa}B$ in cancer cells and marcrophages. In the present study, we investigated whether thiacremonone could increase susceptibility of prostate cancer cells (PC-3 and DU145) to docetaxel via inactivation of NF-${\kappa}B$. We found that the combination treatment of thiacremonone (50 ${\mu}g$/ml) with docetaxel (5 nM) was more effective in the inhibition of prostate cancer cell growth and induction of apoptosis accompanied with the significant inhibition of NF-${\kappa}B$ activity than those by the treatment of thiacremonone or docetaxel alone. It was also found that NF-${\kappa}B$ target gene expression of Bax, caspase-3 and caspase-9 was much more significantly enhanced, but the expression of Bcl-2 was also much more significantly inhibited by the combination treatment. These results indicate that thiacremonone inhibits NF-${\kappa}B$, and enhances the susceptibility of prostate cancer cells to docetaxel. Thus, thiacremonone could be useful as an adjuvant anti-cancer agent.

• Journal of Microbiology and Biotechnology
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• 제23권1호
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• pp.64-68
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• 2013

Previous studies have shown that lactic acid bacteria can inhibit inflammatory responses, but the mechanisms are very little known. In this study, transaction and expression of three proinflammatory factors, iNOS, PTGS-2, and IL8, which are closely related to the inflammatory response, were investigated by luciferase reporter assay and RTPCR in HT-29 cells treated by Lactobacillus acidophilus. The results showed that the live L. acidophilus sharply down-regulated the transcription of these three genes. Because there was a NF-${\kappa}B$ binding site located at -265 bp, -225 bp, and -95 bp upstream of the iNOS, PTGS-2, and IL8 promoters, respectively, we further addressed the effects of NF-${\kappa}B$ on transaction of the three promoters by cotransfection. As was expected, NF-${\kappa}Bs$ remarkably upregulated the activity of the reporter gene and, no effect of NF-${\kappa}B$s on IL-8 promoter transaction was found after NF-${\kappa}B$ binding site mutation of the IL8 promoter in HT-29 cells. In conclusion, the live L. acidophilus decreased the transcriptional activity of NF-${\kappa}B$ and, in turn, inhibited the transaction of NF-${\kappa}B$ on the three proinflammatory factors mentioned above.

• Asian Pacific Journal of Cancer Prevention
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• 제13권4호
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• pp.1657-1662
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• 2012

Fucosyltransferase IV (FUT4) has been implicated in cell adhesion, motility, and tumor progression in human epidermoid carcinoma A431 cells. We previously reported that it promotes cell proliferation through the ERK/MAPK and PI3K/Akt signaling pathways; however, the molecular mechanisms underlying FUT4-induced cell invasion remain unknown. In this study we determined the effect of FUT4 on expression of matrix metalloproteinase (MMP)-12 induced by EGF in A431 cells. Treatment with EGF resulted in an alteration of cell morphology and induced an increase in the expression of MMP-12. EGF induced nuclear translocation of nuclear factor kB (NF-${\kappa}B$) and resulted in phosphorylation of $IkB{\alpha}$ in a time-dependent manner. In addition, ERK1/2 and p38 MAPK were shown to play a crucial role in mediating EGF-induced NF-${\kappa}B$ translocation and phosphorylation of $I{\kappa}B{\alpha}$ when treated with the MAPK inhibitors, PD98059 and SB203580, which resulted in increased MMP-12 expression. Importantly, we showed that FUT4 up-regulated EGF-induced MMP-12 expression by promoting the phosphorylation of ERK1/2 and p38 MAPK, thereby inducing phosphorylation/degradation of $I{\kappa}B{\alpha}$, NF-${\kappa}B$ activation. Base on our data, we propose that FUT4 up-regulates expression of MMP-12 via a MAPK-NF-${\kappa}B$-dependent mechanism.

• Journal of Microbiology and Biotechnology
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• 제25권7호
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• pp.1047-1055
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• 2015

For the search of a potent first-in-class compound to inactivate macrophages responsible for inflammatory responses, in the present study, we investigated the anti-nflammatory effects of YH-1118, a novel synthetic compound, in a lipopolysaccharide (LPS)-stimulated mouse macrophage cell line, Raw 264.7. YH-1118 inhibited LPS-induced nitric oxide (NO) production and inducible NO synthase (iNOS) expression at both the protein and mRNA levels. The suppression of LPS-induced iNOS expression by YH-1118 was mediated via nuclear factor kappa B (NF-κB), but not activator protein-1 (AP-1) transcription factor. This was supported by the finding that YH-1118 attenuated the phosphorylation of inhibitor of κBα (IκBα) and nuclear translocation and DNA binding activity of NF-κB. Through the mechanisms that YH-1118 inhibited the activation of IκB kinases (IKKs), upstream activators of NF-κB, or p38 MAPK, YH-1118 significantly suppressed LPS-induced production of pro-inflammatory cytokines, tumor necrosis factor-α, interleukin-1β (IL-1β), and IL-6 (p < 0.05). In conclusion, our results suggest that YH-1118 inhibits LPS-induced inflammatory responses by blocking IKK and NF-κB activation in macrophages, and may be a therapeutic candidate for the treatment of various inflammatory diseases.

• 한국전자파학회논문지
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• 제20권9호
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• pp.900-905
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• 2009

본 논문에서는 전류 블리딩(bleeding)과 입력 인덕티브 직렬-피킹을 이용한 공통 드레인 귀환(Common Drain Feedback: CDFB) CMOS 광대역 저잡음 증폭기(Low Noise Amplifier: LNA)를 설계하였다. 캐스코드 증폭기와 귀환 증폭기를 DC 결합하여 블리딩 전류의 조정을 통해 LNA의 이득과 잡음 지수(Noise figure: NF)의 동적 제어를 실현하였다. 제작한 LNA는 2.5 GHz의 대역폭에서, 고이득 영역은 $1.7{\sim}2.8\;dB$ NF와 17.5 dB 이득, 그리고 27 mW의 전력 소비를 보이고, 저 이득 영역은 $2.7{\sim}4.0\;dB$ NF와 14 dB 이득, 그리고 1.8 mW의 전력 소비를 보인다.

• Molecular & Cellular Toxicology
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• 제5권2호
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• pp.141-146
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• 2009

Toll-like receptors (TLRs) induce innate immune responses by recognizing conserved microbial structural molecules. All TLR signaling pathways culminate in the activation of nuclear factor kappa-B (NF-$\kappa$B) leading to the induction of inflammatory gene products such as cyclooxygenase-2 (COX-2). Deregulated activation of TLRs can lead to the development of severe systemic inflammation. Divalent heavy metals, cadmium and mercury, have been used for thousands of years. While cadmium and mercury are clearly toxic to most mammalian organ systems, especially the immune system, their underlying toxic mechanism(s) remain unclear. Here, we report biochemical evidence that cadmium, but not mercury, inhibits NF-$\kappa$B activation and COX-2 expression induced by TLR2 or TLR4 agonists, while cadmium does not inhibit NF-$\kappa$B activation induced by the downstream signaling component of TLRs, MyD88. Thus, the target of cadmium to inhibit NF-$\kappa$B activation may be upstream of MyD88 including TLRs themselves, or events leading to TLR activation by agonists.

• BMB Reports
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• 제35권3호
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• pp.337-342
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• 2002

Many components that are derived from medicinal or dietary plants possess potential chemopreventive properties. Curcumin, a yellow coloring agent from turmeric (Curcuma longa Linn, Zingiberaceae), possesses strong antimutagenic and anticarcinogenic activities. In this study, we have found that curcumin inhibits the 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced nuclear factor ${\kappa}B$ (NF-${\kappa}B$) activation by preventing the degradation of the inhibitory protein $I{\kappa}B{\alpha}$ and the subsequent translocation of the p65 subunit in cultured human promyelocytic leukemia (HL-60) cells. Alternatively, curcumin repressed the TPA-induced activation of NF-${\kappa}B$ through direct interruption of the binding of NF-${\kappa}B$ to its consensus DNA sequences. Likewise, the TPA-induced DNA binding of the activator protein-1 (AP-1) was inhibited by curcumin pretreatment.