• The Korean Journal of Physiology and Pharmacology
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• v.4 no.5
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• pp.339-346
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• 2000

Using murine immortalized microglial cells (BV-2), we examined the regulation of RANTES production stimulated by lipopolysaccharide (LPS), focusing on the role of mitogen-activated protein kinase (MAPK) and nuclear factor $(NF)-{\kappa}B.$ The result showed that RANTES (regulated upon activation of normal T cell expressed and secreted) was induced at the mRNA and protein levels in a dose- and time-dependent manner in response to LPS. From investigations of second messenger pathways involved in regulating the secretion of RANTES, we found that LPS induced phosphorylation of extracellular signal-regulated kinase (Erk), p38 MAPK and c-Jun-N-terminal kinase (JNK), and activated $(NF)-{\kappa}B.$ To determine whether this MAPK phosphorylation is involved in LPS-stimulated RANTES production, we used specific inhibitors for p38 MAPK and Erk, SB 203580 and PD 98059, respectively. LPS-induced RANTES production was reduced approximately 80% at $25\;{\mu}M$ of SB 203580 treatment. But PD 98059 did not affect RANTES production. Pyrrolidine-dithiocarbamate (PDTC), $(NF)-{\kappa}B$ inhibitor, reduced RANTES secretion. These results suggest that LPS-induced RANTES production in microglial cells (BV-2) is mainly mediated by the coordination of p38 MAPK and $(NF)-{\kappa}B$ cascade.

• Molecules and Cells
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• v.25 no.2
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• pp.253-257
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• 2008

Acrolein is a highly electrophilic ${\alpha},{\beta}$-unsaturated aldehyde present in a number of environmental sources, especially cigarette smoke. It reacts strongly with the thiol groups of cysteine residues by Michael addition and has been reported to inhibit nuclear $factor-{\kappa}B$ ($NF-{\kappa}B$) activation by lipopolysaccharide (LPS). The mechanism by which it inhibits $NF-{\kappa}B$ is not clear. Toll-like receptors (TLRs) play a key role in sensing microbial components and inducing innate immune responses, and LPS-induced dimerization of TLR4 is required for activation of downstream signaling pathways. Thus, dimerization of TLR4 may be one of the first events involved in activating TLR4-mediated signaling pathways. Stimulation of TLR4 by LPS activates both myeloid differential factor 88 (MyD88)- and TIR domain-containing adapter inducing $IFN{\beta}$ (TRIF)-dependent signaling pathways leading to activation of $NF-{\kappa}B$ and IFN-regulatory factor 3 (IRF3). Acrolein inhibited $NF-{\kappa}B$ and IRF3 activation by LPS, but it did not inhibit $NF-{\kappa}B$ or IRF3 activation by MyD88, inhibitor ${\kappa}B$ kinase $(IKK){\beta}$, TRIF, or TNF-receptor-associated factor family member-associated $NF-{\kappa}B$ activator (TANK)-binding kinase 1 (TBK1). Acrolein inhibited LPS-induced dimerization of TLR4, which resulted in the down-regulation of $NF-{\kappa}B$ and IRF3 activation. These results suggest that activation of TLRs and subsequent immune/inflammatory responses induced by endogenous molecules or chronic infection can be modulated by certain chemicals with a structural motif that enables Michael addition.

• Journal of Veterinary Clinics
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• v.28 no.2
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• pp.190-195
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• 2011

Nuclear factor ${\kappa}B$ (NF-${\kappa}B$) is a nuclear transcription factor that modulates the expression of inflammatory cytokines such as tumor necrosis factor (TNF)-${\alpha}$. trans-10, cis-12 (t10c12)-conjugated linoleic acid (CLA) participates in the inhibition of TNF-${\alpha}$ production upon lipopolysaccharide (LPS)-stimulation. However, in our previous study, t10c12-CLA enhanced the production of TNF-${\alpha}$ by LPS-unstimulated porcine peripheral blood mononuclear cells (PBMCs) and RAW 264.7 macrophages in vitro. To resolve this apparent contradiction, we hypothesized that the effect of t10c12-CLA on TNF-${\alpha}$ production depends on NF-${\kappa}B$ activation induced by LPS stimulation. To test this hypothesis, we assessed the in vitro effect of t10c12-CLA on TNF-${\alpha}$ production and NF-${\kappa}B$ p65 activity in LPS-stimulated and LPS-unstimulated porcine PBMCs. t10c12-CLA treatment resulted in increased TNF-${\alpha}$ production by LPS-unstimulated PBMCs but decreased TNF-${\alpha}$ production by LPS-stimulated PBMCs. t10c12-CLA increased the degradation of inhibitory ${\kappa}B$ ($I{\kappa}B$)-${\alpha}$ protein and activated NF-${\kappa}B$ p65 in LPS-unstimulated PBMCs, but had the opposite effect in LPS-stimulated PBMCs. Notably, t10c12-CLA enhanced NF-${\kappa}B$ p65 binding activity in LPS-unstimulated PBMCs exposed to caffeic acid phenethyl ester (CAPE), a NF-${\kappa}B$ inhibitor. Conversely, it inhibited NF-${\kappa}B$ p65 binding activity in LPS-stimulated PBMCs exposed to CAPE. These results suggest that t10c12-CLA may have different actions under different physiological conditions, and that its effect may be associated with a change in NF-${\kappa}B$ p65 activity.

• Journal of Veterinary Clinics
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• v.32 no.2
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• pp.135-140
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• 2015

Trans-10, cis-12-conjugated linoleic acid (t10c12-CLA) has been shown to participate in the regulation of anti-inflammatory effects. The objectives of this study were to examine the effects of t10c12-CLA on reactive oxygen species (ROS) and nitric oxide (NO) production and nuclear factor-kappaB (NF-${\kappa}B$) activation in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells and to determine whether these effects were associated with change of intracellular calcium ion ($Ca^{2+}$). ROS production was increased in LPS-stimulated RAW 264.7 cells, and this effect was suppressed by 1,2-bis-(o-aminophenoxy) ethane-N,N,N',N'-tetraacetic acid-acetoxymethyl ester (BAPTA/AM), a calcium chelator. t10c12-CLA suppressed ROS production in LPS-stimulated RAW 264.7 cells, which was further more decreased by treatment with BAPTA/AM. These indicated that t10c12-CLA decreases $Ca^{2+}$-dependent ROS production in LPS-stimulated RAW 264.7 cells. Similarly, NF-${\kappa}B$ p65 DNA binding activity and NO production were decreased by treatment with either t10c12-CLA, BAPTA/AM, or t10c12-CLA and BAPTA/AM combination. However, there were no differences between t10c12-CLA and BAPTA/AM treatment in NO production of LPS-stimulated RAW 264.7 cells. These data indicate that t10c12-CLA inhibits the increases in ROS and NO production and the NF-${\kappa}B$ activation in LPS-stimulated condition. These results suggested that CLA exerts potent anti-inflammatory effects by suppression of LPS-induced ROS and NO production, and NF-${\kappa}B$ activationn via $Ca^{2+}$-dependent pathway.

• Journal of Life Science
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• v.10 no.2
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• pp.55-60
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• 2000

We examined the effects of Kamgil-Tang on the process of lipopolysaccharide (LPS)-induced unclear factor (NF)-${\kappa}$ Bp65 and inhibitory (I)-${\kappa}$ B${\alpha}$ alteration in RAW 264.7 cell and acute lung injury in rats. Immunoblot analysis showed that LPS-induced degradation of I-${\kappa}$ B${\alpha}$ in RAW 264.7 was inhibited by pretreatment of Kamgil-Tang. The total cells of bronchoalveolar lavage fluid by LPS challenge markedly decreased in the Kamgil-Tang pretreatment rats. Kamgil-Tang pretreatment caused also a decline in neutrophils infiltration into interstitium of the lung. In the alveolar macrophages and neutrophils, decreased NF-${\kappa}$ Bp65 and inducible nitric oxide synthase and increased I-${\kappa}$ B${\alpha}$ immunoreaction were detected in Kamgil-Tang pretreated rats compared with LPS alone treated ones. It may be concluded that Kamgil-Tang attenuates the development of LPS-induced inflammation by reduction of NF-${\kappa}$ Bp65 activation and neutrophil-mediated acute lung injury. Kamgil-Tang would be useful as a therapeutic agent for endotoxin-induced lung disease.

• The Korean Journal of Physiology and Pharmacology
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• v.19 no.3
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• pp.211-218
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• 2015

The present study showed that silymarin, a polyphenolic flavonoid isolated from milk thistle (Silybum marianum), inhibited lipopolysaccharide (LPS)-induced morphological changes in the mouse RAW264.7 macrophage cell line. We also showed that silymarin inhibited the nuclear translocation and transactivation activities of nuclear factor-kappa B (NF-${\kappa}B$), which is important for macrophage activation-associated changes in cell morphology and gene expression of inflammatory cytokines. BAY-11-7085, an NF-${\kappa}B$ inhibitor, abrogated LPS-induced morphological changes and NO production, similar to silymarin. Treatment of RAW264.7 cells with silymarin also inhibited LPS-stimulated activation of mitogen-activated protein kinases (MAPKs). Collectively, these experiments demonstrated that silymarin inhibited LPS-induced morphological changes in the RAW264.7 mouse macrophage cell line. Our findings indicated that the most likely mechanism underlying this biological effect involved inhibition of the MAPK pathway and NF-${\kappa}B$ activity. Inhibition of these activities by silymarin is a potentially useful strategy for the treatment of inflammation because of the critical roles played by MAPK and NF-${\kappa}B$ in mediating inflammatory responses in macrophages.

• Journal of Acupuncture Research
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• v.21 no.6
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• pp.19-36
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• 2004

Objective : The purpose of this study was to investigate the effect of Bee Venom and Melittin Solution on the lipopolysaccharide(LPS) and sodium nitroprusside(SNP)-induced expression of prostaglandin $E_2(PGE_2)$, cyclooxygenase-2(COX-2), nuclear factor kappa B($NF-{\kappa}B$) and nuclear factor kappa B($NF-{\kappa}B$) dependent luciferase activity in RAW 264.7 cells, a murine macrophage cell line. Methods : The expression of PGE2 was determined by determination of $PEG_2$, COX-2 was by western blotting with corresponding antibodies, $NF-{\kappa}B$ was by gel mobility shift assay method and $NF-{\kappa}B$ dependent luciferase activity was investigated by luciferase assay in RAW 264.7 cells. Results : 1. LPS and SNP-induced expression of $PEG_2$ was significant after 24hour. 2. The 0.5, 1 and $5{\mu}g/mL$ of bee venom and the 5 and $10{\mu}g/mL$ of melittin solution inhibited significantly LPS-induced expression of $PEG_2$ and, the $5{\mu}g/mL$ of bee venom and the 5 and $10{\mu}g/mL$ of melittin solution inhibited significantly SNP-induced expression of $PEG_2$ compared with control, respectively. The 0.5 and $1{\mu}g/mL$ of bee venom could not significantly inhibit SNP-induced expression of $PEG_2$ compared with control. 3. The $5{\mu}g/mL$ of bee venom and the 5 and $10{\mu}g/mL$ of melittin solution inhibited significantly LPS and SNP-induced expression of COX-2 compared with control, respectively. The 0.5 and $1{\mu}g/mL$ of bee venom inclined to decrease LPS and SNP-induced expression of COX-2 compared with control. 4. The 0.5, 1 and $5{\mu}g/mL$ of bee venom and the 5 and $10{\mu}g/mL$ of melittin solution inhibited significantly LPS and SNP-induced expression of $NF-{\kappa}B$ compared with control, respectively. 5. The 0.5, 1 and $5{\mu}g/mL$ of bee venom and the 5 and $10{\mu}g/mL$ of melittin solution inhibited significantly LPS-induced expression of $NF-{\kappa}B$ dependent luciferase activity and the 1 and $5{\mu}g/mL$ of bee venom and the 5 and $10{\mu}g/mL$ of melittin solution inhibited significantly SNP-induced expression of $NF-{\kappa}B$ dependent luciferase activity compared with control, respectively. The $NF-{\kappa}B$ inhibitor also inhibited significantly LPS and SNP-induced expression of $NF-{\kappa}B$ dependent luciferase activity compared with control. 6. The 0.5, 1 and $5{\mu}g/mL$ of bee venom and the 5 and $10{\mu}g/mL$ of melittin solution inhibited significantly LPS + IFN-${\gamma}$, TNF-${\alpha}$ and LPS + TNF-${\alpha}$-induced expression of $NF-{\kappa}B$ dependent luciferase activity compared with control, respectively. The $NF-{\kappa}B$ inhibitor also inhibited significantly LPS and SNP-induced expression of $NF-{\kappa}B$ dependent luciferase activity compared with control. Conclusions : These results suggest the inhibitory action of bee venom and melittin solution on the inflammatory mediators such as $PEG_2$, COX-2 and $NF-{\kappa}B$.

• Journal of Veterinary Clinics
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• v.31 no.6
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• pp.469-476
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• 2014

The aims of this study were to explore the effects of conjugated linoleic acid (CLA) on reactive oxygen species (ROS) production in lipopolysaccharide (LPS)-naïve and LPS-stimulated RAW 264.7 macrophages and to examine whether these effects affect the regulation of tumor necrosis factor-alpha (TNF-${\alpha}$) production, and nuclear factor-kappa B (NF-${\kappa}B$) and peroxisome proliferator-activated receptor gamma ($PPAR{\gamma}$) activation. Trans-10, cis-12(t10c12)-CLA increased the production of ROS, as well as TNF-${\alpha}$ in LPS-naïve RAW 264.7 cells. The CLA-induced TNF-${\alpha}$ production was suppressed by treatment of diphenyleneiodonium chloride (DPI), a NADPH oxidase inhibitor. In addition, CLA enhanced the activities of NF-${\kappa}B$ and $PPAR{\gamma}$ in LPS-naïve RAW 264.7 cells, and this effect was abolished with DPI treatment. LPS treatment increased ROS production, whereas CLA reduced LPS-induced ROS production. LPS increased both TNF-${\alpha}$ production and NF-${\kappa}B$ activity, whereas t10c12-CLA reduced TNF-${\alpha}$ production and NF-${\kappa}B$ activity in LPS-stimulated RAW 264.7 cells. DPI treatment suppressed LPS-induced ROS production and NF-${\kappa}B$ activity. Moreover, DPI enhanced the inhibitory effects of t10c12-CLA on TNF-${\alpha}$ production and NF-${\kappa}B$ activation in LPS-stimulated RAW 264.7 cells. However, neither t10c12-CLA nor DPI affected $PPAR{\gamma}$ activity in LPS-stimulated RAW 264.7 cells. Taken together, these data indicate that t10c12-CLA induces TNF-${\alpha}$ production by increasing ROS production in LPS-naïve RAW 264.7 cells, which is mediated by the enhancement of NF-${\kappa}B$ activity via $PPAR{\gamma}$ activation. By contrast, t10c12-CLA suppresses TNF-${\alpha}$ production by inhibiting ROS production and NF-${\kappa}B$ activation via a $PPAR{\gamma}$-independent pathway in LPS-stimulated RAW 264.7 cells. These results suggest that t10c12-CLA can modulate TNF-${\alpha}$ production and NF-${\kappa}B$ activation through formation of ROS in RAW 264.7 macrophages.

• Journal of Applied Biological Chemistry
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• v.61 no.2
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• pp.205-211
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• 2018

Rebaudioside A is a natural sweetener isolated from Stevia rebaudiana Bertoni, one of the glycosides based on steviol. Recent studies have shown that rebaudioside A inhibits the inflammatory response by inhibiting cytokines secretion such as interleukin-$1{\alpha}/1{\beta}$ in activated RAW264.7 mouse macrophage cells by LPS. However, the inhibitory mechanism of inflammation by rebaudioside A in the presence of LPS has not been fully elucidated. Therefore, in this study, we tried to investigate the anti-inflammatory activity of rebaudioside A at the protein level when RAW264.7 cells were stimulated by LPS. The inducible nitric oxide synthase protein expression level was reduced in the group treated with $250{\mu}M$ rebaudioside A compared to the LPS-treated group. In addition, the mRNA expression level of $NF-{\kappa}B$, which is a representative nuclear transcription factor by inflammatory signal, was also decreased as compared with that of LPS-treated group. In addition, $NF-{\kappa}B$ and inhibitor-${\kappa}B$ ($I-{\kappa}B$) complexes that are known to be dissociated by $I-{\kappa}B$ phosphorylation and ubiquitination were less phosphorylated than LPS treated group in the presence rebaudioside A. Finally, we could find that rebaudioside A was involved in the $NF-{\kappa}B$ pathway through reducing extracellular signal-regulated kinase1/2 phosphorylation in a concentration-dependent manner. These results suggest that rebaudioside A might suppress inflammatory reaction through MAPK and $NF-{\kappa}B$ regulation in LPS-stimulated RAW264.7.

• Korean Journal of Plant Resources
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• v.25 no.3
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• pp.299-307
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• 2012

This work aimed to elucidate the anti-inflammatory effects of ethyl acetate fraction from Cnidium officinale Makino with a cellular system of LPS-stimulated RAW 264.7 and THP-1 cells. Some key pro-inflammatory cytokines and mediators including NO, iNOS, $PGE_2$, COX-2, TNF-${\alpha}$, NF-${\kappa}B$ p50 and NF-${\kappa}B$ p65 were studied by sandwich ELISA and western blot analysis. Ethyl acetate fraction could significantly inhibit the production of NO, $PGE_2$, TNF-${\alpha}$, iNOS and COX-2 in LPS-stimulated cell than that of single LPS-stimulated. And ethyl acetate fraction suppresses the activation of NF-${\kappa}B$ p50 and NF-${\kappa}B$ p65. All the results showed that ethyl acetate fraction had a good anti-inflammatory effect on LPS-stimulated RAW264.7 and THP-1 cells. Taken together, the anti-inflammatory actions of ethyl acetate fraction from Cnidium officinale Makino might be due to the down-regulation of NO, $PGE_2$, TNF-${\alpha}$, iNOS and COX-2 via the suppression of NF-${\kappa}B$ activation.