• The Korean Journal of Physiology and Pharmacology
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• v.5 no.1
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• pp.55-63
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• 2001

In macrophages, lipopolysaccharide (LPS) alone or in combination with $interferon-{\gamma}\;(IFN-{\gamma})$ has been shown to release a nitric oxide (NO) through the increase of the transcription of the inducible nitric oxide synthase (iNOS) gene. To investigate the exact intracellular signaling pathway of the regulation of iNOS gene transcription by LPS plus $IFN-{\gamma},$ the effects of protein tyrosine kinase (PTK) inhibitor and protein kinase C (PKC) inhibitors on NO production, iNOS mRNA expression, nuclear $factor-_{\kappa}B\;(NF-_{\kappa}B)$ binding activity and the promoter activity of iNOS gene containing two $NF-_{\kappa}B$ sites have been examined in a mouse macrophage RAW 264.7 cells. LPS or $IFN-{\gamma}$ stimulated NO production, and their effect was enhanced synergistically by mixture of LPS and $IFN-{\gamma}.$ The PTK inhibitor such as tyrphostin reduced LPS plus $IFN-{\gamma}-induced$ NO production, iNOS mRNA expression and $NF-_{\kappa}B$ binding activity. In contrast, PKC inhibitors such as H-7, Ro-318220 and staurosporine did not show any effect on them. In addition, transfection of RAW 264.7 cells with iNOS promoter linked to a CAT reporter gene revealed that tyrphostin inhibited the iNOS promoter activity through the $NF-_{\kappa}B$ binding site, whereas PKC inhibitors did not. Taken together, these suggest that PTK, but not PKC pathway, is involved in the regulation of the iNOS gene transcription through the $NF-_{\kappa}B$ sites of iNOS promoter in RAW 264.7 macrophages by LPS plus $IFN-{\gamma}$.

• Journal of Life Science
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• v.29 no.4
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• pp.436-441
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• 2019

Nelumbo nucifera, also known as sacred lotus, has mainly been used as a food throughout the Asian countries. In the present study, we prepared ethanol extracts from leaf (NL), seed (NS), and seedpod (NSP) of Nelumbo nucifera and investigated their anti-inflammatory activities in mouse macrophage RAW 264.7 cells. To evaluate the anti-inflammatory activities of NL, NS, and NSP, nitric oxide (NO) production was measured in LPS-stimulated RAW 264.7 cells. NL, NS, and NSP significantly reduced NO production in a dose-dependent manner without affecting cell viabilities. NL, NS, and NSP dramatically decreased the protein expression of pro-inflammatory genes such as iNOS and COX-2. NL, NS, and NSP also suppressed phosphorylation of MAPKs and the nuclear translocation of $NF-{\kappa}B$ p65 indicating they have their anti-inflammatory activities via regulating mitogen-activated protein kinases (MAPKs) and nuclear factor kappa B ($NF-{\kappa}B$) pathways. In addition, we analyzed the production of reactive oxygen species (ROS) by the treatment of NL, NS, and NSP. All extracts reduced ROS production in a dose-dependent manner. And also, they increased heme oxygenase-1 (HO-1) protein expression and the nuclear translocation of nuclear respiratory factor 2 (Nrf2). In conclusion, our results suggest that Nelumbo nucifera has its anti-inflammatory activity via regulating MAPKs, $NF-{\kappa}B$, and Nrf2/HO-1 pathways.

• Molecules and Cells
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• v.27 no.2
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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.

• BMB Reports
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• v.35 no.1
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• pp.28-40
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• 2002

Apoptosis is a mode of cell death that plays an important role in both pathological and physiological processes. Research during the last decade has delineated the entire machinery needed for cell death, and its constituents were found to pre-exist in cells. The apoptotic cascade is triggered when cells are exposed to an apoptotic stimulus. It has been known for several years that inhibitors of protein synthesis can potentiate apoptosis that is induced by cytokines and other inducers. Until 1996, it was not understood why protein synthesis inhibitors potentiate apoptosis. Then three reports appeared that suggested the role of the transcription factor NF-${\kappa}B$ activation in protecting the cells from TNF-induced apoptosis. Since then several proteins have been identified that are regulated by NF-${\kappa}B$ and are involved in cell survival, proliferation, and protection from apoptosis. It now seems that when a cell is attacked by an apoptotic stimulus, the cell responds first by activating anti-apoptotic mechanisms, which mayor may not be followed by apoptosis. Whether or not a cell undergoes proliferation, the survival, or apoptosis, appears to involve a balance between the two mechanisms. Inhibitors of protein synthesis seem to suppress the appearance of protein that are involved in anti-apoptosis. The present review discusses how NF-${\kappa}B$ controls apoptosis.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2010.10a
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• pp.13-13
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• 2010

In the present study, the chemical constituents of Artemisia fukudo essential oil (AFE) were investigated using GC-MS. The major constituents were ${\alpha}$-thujone (40.28%), ${\beta}$-thujone (12.69%), camphor (6.95%) and caryophyllene (6.01%). We also examined the effects of AFE on the production of nitric oxide (NO), prostaglandin $E_2$ ($PGE_2$), tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$), interleukin-IL-$1{\beta}$ (IL-$1{\beta}$), and IL-6 in lipopolysaccharide (LPS)-activated RAW 264.7 cells. Western blotting and RT-PCR analyses indicated that AFE has potent dose-dependent inhibitory effects on pro-inflammatory cytokines and mediators. We investigated the mechanism by which AFE inhibits NO and $PGE_2$ by examining the level of nuclear factor-${\kappa}B$ (NF-${\kappa}B$: p50 and p65) activation within the mitogen-activated protein kinase (MAPK: ERK, JNK and p38) pathway, which is an inflammation induced signal pathway in RAW 264.7 cells. AFE inhibited LPS-induced ERK, JNK and p38 phosphorylation. Furthermore, AFE inhibited the LPS-induced phosphorylation and degradation of $I{\kappa}B-{\alpha}$, which is required for the nuclear translocations of the p50 and p65 NF-${\kappa}B$ subunits in RAW 264.7 cells. Our results suggest that AFE might exert an anti-inflammatory effect by inhibiting the expression of pro-inflammatory cytokines. Such an effect is mediated by a blocking of NF-${\kappa}B$ activation which consequently inhibits the generation of inflammatory mediators in RAW 264.7 cells. AFE may be useful for treating inflammatory diseases.

• The Journal of Korean Medicine
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• v.25 no.3
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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.

• Journal of Life Science
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• v.19 no.10
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• pp.1396-1402
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• 2009

Hizikia fusiforme is a kind of edible brown seaweed that grows mainly in the northwest Pacific including Korea, Japan and China, and has been widely used as food in Korea. Induction of cyclooxygenase-2 (COX-2) expression and prostaglandin $E_2$ ($PGE_2$) production is thought to have beneficial immunomodulatory effects in acute and chronic inflammatory disorders. In this study, we investigated the effects of extracts of H. fusiforme on the expression of COX-2 and production of $PGE_2$ in U937 human pre-monocytic cell models. In U937 cells stimulated with phorbol 12-myristate 13-acetate (PMA) to mimic inflammation, methanol extract of H. fusiforme (MEHF) and ethanol extract of H. fusiforme (EEHF), but not water extract of H. fusiforme (WEHF), inhibited PMA-induced expression of both COX-2 protein and mRNA, which was associated with inhibition of $PGE_2$ production. To investigate the mechanism by which MEHF and EEHF inhibit COX-2 gene expression and $PGE_2$ production, we examined the activation of nuclear factor-kappaB (NF-$\kappa$B) in U937 cells. Pre-treatment with MEHF and EEHF significantly attenuated the PMA-induced IkappaB degradation and prevented nuclear translocation of NF-$\kappa$B. Taken together, these findings provide important new insights into the possible molecular mechanisms of the anti-inflammatory activity of H. fusiforme.

• Journal of Physiology & Pathology in Korean Medicine
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• v.23 no.1
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• pp.206-213
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• 2009

Sophora flavescens, as a traditional herbal medicine, has been used to treat with a variety of disesases, In previous reports, S. flavescens and sophoraflavanone G (a prenylated flavonoid from S. flavescens) inhibited cytokines productions in LPS-induced Raw 264.7 macrophages cells and BV2 microglial cells. We examined on the anti-allergic effect of S. flavescens on the PMA plus A23187-induced rat leukemia (RBL-2H3) cells. S. flavescens inhibited the release of $\beta$-hexosaminidase and productions and expressions of tumor necrosis factor (TNF)-$\alpha$, interleukin (IL)-4 and cyclooxygenase (COX)-2 in a dose-dependent manner on stimulated RBL-2H3 cells, however, S. flavescens not affect cell viability. The protein expression level of nuclear factor (NF)-${\kappa}B$ (p65) was decreased in the nucleus and suppressed the degradation of inhibitory protein $I{\kappa}B-{\alpha}$ protein, the activation of extracellular signal-regulated kinases (ERK) mitogen-activated protein kinase (MAPK) by S. flavescens. These results suggest that S. flavescens could be involved anti-allergic effect by control of $NF-{\kappa}B$ (p65) translocation into the nucleus through inhibition of $I{\kappa}B-{\alpha}$ degradation and suppression of pro-inflammatory cytokines expression.

• Fisheries and Aquatic Sciences
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• v.21 no.5
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• pp.14.1-14.8
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• 2018

The objective of this study was to investigate the anti-inflammatory effects of the pepsinolytic hydrolysate from the fish frame, Johnius belengerii, on lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. The J. belengerii frame hydrolysate (JFH) significantly suppressed nitric oxide (NO) secretion on LPS-stimulated RAW264.7 macrophages. Moreover, the JFH markedly inhibited the levels of protein and mRNA expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2). Furthermore, the LPS-stimulated mRNA expression of pro-inflammatory cytokines, including tumor necrosis factor $(TNF)-{\alpha}$, interleukin $(IL)-1{\beta}$, and IL-6 was downregulated when cells were cultured with the JFH. The JFH significantly reduced the phosphorylation of c-Jun N-terminal kinase (JNK) and the translocation of nuclear factor-kappa B ($NF-{\kappa}B$) in macrophages. As the result, the JFH has the potential anti-inflammatory activity via blocking the JNK and $NF-{\kappa}B$ signal pathways.

• The Korean Journal of Physiology and Pharmacology
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• v.22 no.2
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• pp.127-134
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• 2018

Myofibrillogenesis regulator-1 (MR-1) is a novel protein involved in cellular proliferation, migration, inflammatory reaction and signal transduction. However, little information is available on the relationship between MR-1 expression and the progression of atherosclerosis. Here we report atheroprotective effects of silencing MR-1 in a model of Ang II-accelerated atherosclerosis, characterized by suppression focal adhesion kinase (FAK) and nuclear factor kappaB ($NF-{\kappa}B$) signaling pathway, and atherosclerotic lesion macrophage content. In this model, administration of the siRNA-MR-1 substantially attenuated Ang II-accelerated atherosclerosis with stabilization of atherosclerotic plaques and inhibited FAK, Akt, mammalian target of rapamycin (mTOR) and NF-kB activation, which was associated with suppression of inflammatory factor and atherogenic gene expression in the artery. In vitro studies demonstrated similar changes in Ang II-treated vascular smooth muscle cells (VSMCs) and macrophages: siRNA-MR-1 inhibited the expression levels of proinflammatory factor. These studies uncover crucial proinflammatory mechanisms of Ang II and highlight actions of silencing MR-1 to inhibit Ang II signaling, which is atheroprotective.