• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제34권1호
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• pp.28-35
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• 2008

Purpose: The nitric oxide (NO) release by inducible nitric oxide synthase (iNOS) is the key events in macrophage response to lipopolysaccharide (LPS) which is suggested to be a crucial mediator for inflammatory and innate immune responses. NO is an important mediator involved in many host defense action and may also lead to a harmful host response to bacterial infection. However, given the importance of iNOS in a variety of pathophysiological conditions, control of its expression and signaling events in response to LPS has been the subject of considerable investigation. Materials and Methods: The Raw264.7 macrophage cell line was used to observe LPS-stimulated iNOS expression. The expression of iNOS is observed by Western blot analysis and real-time RT-PCR. Protein kinase C $(PKC)-{\alpha}$ overexpressing Raw264.7 cells are established to determine the involvement of $PKC-{\alpha}$ in LPS-mediated iNOS expression. $NF-{\kappa}B$ activity is measured by $I{\kappa}B{\alpha}$ degradation and $NF-{\kappa}B$ luciferase activity assay. Results: We found that various PKC isozymes regulate LPS-induced iNOS expression at the transcriptional and translational levels. The involvement of $PKC-{\alpha}$ in LPS-mediated iNOS induction was further confirmed by increased iNOS expression in $PKC-{\alpha}$ overexpressing cells. $NF-{\kappa}B$ dependent transactivation by LPS was observed and $PKC-{\alpha}$ specific inhibitory peptide abolished this activation, indicating that $NF-{\kappa}B$ activation is dependent on $PKC-{\alpha}$. Conclusion: Our data suggests that $PKC-{\alpha}$ is involved in LPS-mediated iNOS expression and that its downstream target is $NF-{\kappa}B$. Although $PKC-{\alpha}$ is a crucial mediator in the iNOS regulation, other PKC isozymes may contribute LPS-stimulated iNOS expression. This finding is needed to be elucidated in further study.

• 대한의생명과학회지
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• 제21권4호
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• pp.218-226
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• 2015

The present study investigated the mechanisms of licochalcone B (LicB)-mediated inhibition of the inflammatory response in murine macrophages. RAW264.7 murine macrophages were cultured in the absence or presence of lipopolysacharide (LPS) with LicB. LicB suppressed the generation of nitric oxide and the pro-inflammatory cytokines interleukin (IL)-$1{\beta}$, IL-6 and tumor necrosis factor-${\alpha}$. LicB also inhibited the expression of mRNA for inducible nitric oxide synthase and pro-inflammatory cytokines induced by LPS. Moreover, LicB inhibited nuclear factor-${\kappa}B$ (NF-${\kappa}B$) and activator protein-1 translocation into the nucleus in a dose-dependent manner. Thus, LicB mainly exerts its anti-inflammatory effects by inhibiting the LPS-induced NF-${\kappa}B$ and activator protein-1 signaling pathways in macrophages, which subsequently diminishes the expression and release of various inflammatory mediators. LicB shows promise as a therapeutic agent in inflammatory diseases.

• Food Science and Biotechnology
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• 제15권2호
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• pp.303-307
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• 2006

Effect of Oenanthe javanica ethanol extract (OJE) on nuclear factor-${\kappa}B$ (NF-${\kappa}B$)-mediated inflammatory reaction in RAW 264.7 macrophage cells was investigated. The OJE dose-dependently inhibited secretions of tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) and prostaglandins $E_2\;(PGE_2)$ from lipopolysaccharide (LPS)-stimulated RAW 264.7 cells and blocked LPS-induced expression of cyclooxygenase-2. To clarify mechanistic basis for its inhibitions of NF-${\kappa}B$ and activator protein-1 (AP-1) activations, effects of OJE on activations of NF-${\kappa}B$ and AP-1 genes by luciferase reporter activity were examined. The LPS-stimulated activations of NF-${\kappa}B$ and AP-1 were significantly blocked by 400 and $600\;{\mu$}g/mL of OJE, implicating that OJE might regulate gene expression through more than one signaling pathway. Cytosolic degradation of I-${\kappa}B{\alpha}$ was inhibited by OJE dose-dependently, indicating that the nuclear translocation of p65 was inhibited by OJE. These findings suggest that the inhibition of LPS-stimulated COX-2 expression by OJE is due to its inhibition of NF-${\kappa}B$ activation by blocking I-${\kappa}B{\alpha}$ degradation, which may be mechanistic basis of anti-inflammatory effects of OJE.

• Journal of Nutrition and Health
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• 제50권1호
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• pp.25-31
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• 2017

퇴행성 뇌신경 질환의 원인이 되는 것으로 알려진 미세아교세포의 과도한 활성화에 의한 신경염증반응에 미치는 미역쇠의 보호 효과를 알아보기 위해 LPS를 처리한 BV2 세포에서 미역쇠에서 얻은 에탄올 추출물을 이용하여 실험을 수행하였다. 미세아교세포의 활성화를 유도하는 LPS의 처리는 신경염증반응의 지표인 NO의 생성량과 이들을 조절하는 iNOS, COX-2의 발현을 증가시켰다. 미역쇠 추출물의 처리는 LPS가 유도하는 NO의 생성량을 농도 의존적으로 억제하였고 iNOS와 COX-2의 발현을 억제하여 NO 생성량 저해와 유사한 양상의 결과를 나타내었다. 미역쇠 추출물의 신경 염증반응 저해 효과가 $NF-{\kappa}B$의 활성화 조절을 통해 일어나는지를 알아보기 위해 $NF-{\kappa}B$의 핵으로의 전이, $I{\kappa}B$의 인산화, $NF-{\kappa}B$ 억제제인 PDTC를 이용한 NO의 생성량에 미치는 효과를 확인하였다. 미역쇠 추출물 처리에 의해 핵분획물에서의 $NF-{\kappa}B$ 발현은 현저히 감소하였고 $I{\kappa}B$의 인산화를 억제하였으며 PDTC의 처리로 NO의 생성량은 감소하였다. 이상의 결과는 미세아교세포의 활성화로 인해 발생되는 신경염증반응에 미역쇠 추출물이 $NF-{\kappa}B$의 활성 억제를 통해 NO의 생성을 저해함으로써 항신경염증 효과가 있음을 보여주는 것으로 미역쇠 추출물이 신경염증 관련 뇌신경 질환의 제어하는데 있어서 치료효과를 가지는 소재로서 이용 가능성에 대한 정보를 제공할 것으로 사료된다.

• 생명과학회지
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• 제20권2호
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• pp.275-280
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• 2010

Sulforaphane은 십자가화 채소에 존재하는 화합물로 항염증, 항암 및 신생혈관 생성의 억제 효과가 알려짐으로써 최근 많은 연구가 활발히 이루어지고 있으나, LPS에 의한 MMP-9 활성 조절에 대한 연구는 매우 미흡한 편이다. 따라서 본 연구에서 sulforaphane이 LPS 유도에 의한 MMP-9 활성에 미치는 영향에 대해서 조사해 보았다. Raw 264.7 세포에 sulforaphane을 전처리 한 후 LPS를 처리하여 gelatin zymography를 실시해 본 결과, LPS에 의해 유도된 MMP-9 활성 증가가 sulforaphane 농도 의존적으로 감소됨을 확인 하였다. 또한 RT-PCR과 MMP-9의 luciferase assay를 통한 실험에서 sulforaphane의 MMP-9 억제효과가 전사단계에서 조절됨을 추측 할 수 있었다. MMP-9 promoter 부위에 여러 가지의 전사조절인자 결합부위가 존재한다. 특히 AP-1과 NF-${\kappa}B$가 중요 전사조절인자로 작용하여 MMP-9 발현조절에 관여한다. 본 실험에서 sulforaphane에 의한 MMP-9 억제효과 기전에 이들 전사조절인자들의 중요한 역할을 조사하였다. AP-1과 NF-${\kappa}B$ 결합부위를 변형 시킨 vector를 transfection하여 MMP-9의 promoter 활성을 측정한 결과, 정상 vector에 비해 그 활성도가 현저히 떨어짐을 확인하였고, LPS에 의해 증가되는 AP-1과 NF-${\kappa}B$의 basal promoter 활성 또한 sulforaphane에 의해 감소됨을 관찰 할 수 있었다. 이상의 결과에서 sulforaphane의 MMP-9 활성억제효과는 AP-1과 NF-${\kappa}B$와 같은 전사인자들이 MMP-9의 전사를 조절함으로써 일어나는 것임을 알 수 있었다. 그리고 sulforaphane은 세포의 invasion능력 또한 효과적으로 억제시킴을 관찰 할 수 있었는데 이는 MMP-9 활성억제효과와 밀접한 관련이 있음을 추측 할 수 있었다.

• Fisheries and Aquatic Sciences
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• 제17권1호
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• pp.27-35
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• 2014

Marine brown algae have been identified as a rich source of structurally diverse bioactive compounds. Whether Myagropsis yendoi ethanolic extracts (MYE) inhibit inflammatory responses was investigated using lipopolysaccharide (LPS)-stimulated microglia BV-2 cells. MYE inhibited LPS-induced nitric oxide (NO) production in a dose-dependent manner and suppressed the expression of inducible nitric oxide synthase in BV-2 cells. MYE also reduced the production of pro-inflammatory cytokines in LPS-stimulated BV-2 cells. LPS-induced nuclear factor-${\kappa}B$ (NF-${\kappa}B$) transcriptional activity and NF-${\kappa}B$ translocation into the nucleus were significantly inhibited by MYE treatment through preventing degradation of the inhibitor ${\kappa}B-{\alpha}$. Moreover, MYE inhibited the phosphorylation of AKT, ERK, JNK, and p38 mitogen-activated protein kinase in LPS-stimulated BV-2 cells. These results indicate that MYE is a potential source of therapeutic or functional agents for neuroinflammatory diseases.

• 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.

• Molecules and Cells
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• 제26권1호
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• pp.48-52
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• 2008

We here demonstrate an anti-inflammatory action of raloxifene, a selective estrogen receptor modulator, in lipopolysaccharide (LPS)-induced murine macrophage RAW264.7 cells. Treatment with raloxifene at micromolar concentrations suppressed the production of nitric oxide (NO) by down-regulating expression of the inducible nitric oxide synthase (iNOS) gene in LPS-activated cells. The decreased expression of iNOS and subsequent reduction of NO were due to inhibition of nuclear translocation of transcription factor NF-${\kappa}B$. These effects were significantly inhibited by exposure to the phosphatidylinositol 3-kinase (PI 3-kinase) inhibitor, LY294002, or by expression of a dominant negative mutant of PI 3-kinase. In addition, pretreatment with raloxifene reduced LPS-induced Akt phosphorylation as well as NF-${\kappa}B$ DNA binding activity and NF-${\kappa}B$-dependent reporter gene activity. Thus our findings indicate that raloxifene exerts its anti-inflammatory action in LPS-stimulated macrophages by blocking the PI 3-kinase-Akt-NF-${\kappa}B$ signaling cascade, and eventually reduces expression of pro-inflammatory genes such as iNOS.

• 대한화장품학회지
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• 제42권4호
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• pp.311-320
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• 2016

카바(Piper methysticum, P. methysticum)는 비뇨생식기 질환, 류머티즘, 위장 장애, 호흡기 자극 및 폐 통증에 대해 전통적으로 사용되는 것으로 알려져 있다. 본 연구에서는 카바에서 분리된 flavokavain C (FKC)가 염증성 유전자의 발현에 관여하는 전사인자인 핵요소-${\kappa}B$ (NF-${\kappa}B$) 의존성 산화 질소(NO) 생산 및 산화 질소 합성 효소(iNOS)의 발현에 리포폴리사카라이드(LPS) 처리된 대식세포에서 항 염증 활성을 나타낸다는 것을 확인하였다. FKC는 과산화수소와 같은 반응성 산소 종(ROS)의 축적을 억제하고, LPS로 유도된 NO 생성 및 각종 염증 관련 유전자(iNOS, IL-$1{\beta}$, IL-6)의 발현을 NF-${\kappa}B$ 및 MAPKs (ERK 및 JNK)의 억제를 통해 농도 의존적으로 줄일 수 있었다. 결론적으로, 이러한 결과는 FKC가 NF-${\kappa}B$ 경로와 MAPKs 포함한 염증 프로세스를 억제하는 능력을 가지고 있음을 나타내며, 이는 항 염증 및 항산화 효능 기반 기능성 화장품에 적용될 수 있음을 암시한다.

• 대한한의학회지
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• 제26권1호
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• pp.18-25
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• 2005

Objective & Methods: We examined the effects of Platycodi radix on the process of lipopolysaccharide (LPS)-induced nuclear factor $NF-{\kappa}Bp65$ and inhibitory $(I)-{\kappa}B{\alpha}$ alteration in RAW 264.7 cells and acute lung injury in rats. Results: Immunoblot analysis showed that LPS-induced degradation of $I-{\kappa}B{\alpha}$ in RAW 264.7 was inhibited by pretreatment of Platycodi radix. The total cells of bronchoalveolar lavage fluid by LPS challenge markedly decreased in the Platycodi radix pretreatment rats. Platycodi radix pretreatment also caused 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 Platycodi radix pretreated rats compared with LPS alone treated ones. Conclusion : It may be concluded that Platycodi radix attenuates the development of LPS-induced inflammation by reduction of $NF-{\kappa}Bp65$ activation and neutrophil-mediated acute lung injury. Platycodi radix would be useful as a therapeutic agent for endotoxin-induced lung disease.