• Title/Summary/Keyword: NF-kB activation

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Structural Features of Polyphenolic Compounds in Their NO Inhibitory Activities

  • Kim, Byung-Hun;Lee, Yong-Gyu;Kim, Tae-Woong;Cho, Jae-Youl
    • Biomolecules & Therapeutics
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    • v.17 no.1
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    • pp.79-85
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    • 2009
  • Polyphenolic compounds are reported to have various pharmacological activities such as anti-oxidative, anti-cancerous, anti-inflammatory and anti-aging effects. Although numerous papers explore their functional roles in many different cellular actions, not many studies handle their structural features in anti-inflammatory responses. In this study, therefore, we examined structural role of substituted transstilbenes in their NO inhibitory and NF-${\kappa}B$ suppressive activities. Of 10 compounds tested, 4 compounds (cinnamic acid, resveratrol, piceatannol and curcumin) displayed NO inhibitory activities in a dose-dependent manner. Similarly, these compounds blocked LPS-induced cytotoxicity of RAW264.7 cells. All NO inhibitory compounds also inhibited $I{\kappa}B{\alpha}$ phosphorylation, a hallmark for NF-${\kappa}B$ activation. However, these inhibitory compounds exhibited distinct suppressive pattern in tumor necrosis factor (TNF)-${\alpha}$- or phorbol-12-myristate-13-acetate (PMA)-induced NF-${\kappa}B$ and AP-1 activation. According to structure-activity relationship study, polarity and size of ring B seem to be important for diminishing NO production. Therefore, our data suggest that substituted trans-stilbenes can be developed as novel anti-inflammatory drug or further developed as lead compounds for another improvement.

Regulation of the Immune System by NF-κB and IκB

  • Liou, Hsiou-Chi
    • BMB Reports
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    • v.35 no.6
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    • pp.537-546
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    • 2002
  • NF-${\kappa}B$/Rel transcription factor family participates in diverse biological processes including embryo development, hematopoiesis, immune regulation, as well as neuronal functions. In this review, the NF-${\kappa}B$/Rel signal transduction pathways and their important roles in the regulation of immune system will be discussed. NF-${\kappa}B$/Rel members execute distinct functions in multiple immune cell types via the regulation of target genes essential for cell proliferation, survival, effector functions, cell trafficking and communication, as well as the formation of lymphoid architecture. Consequently, proper activation of NF-${\kappa}B$/Rel during immune responses to allergens, auto-antigens, allo-antigens, and pathogenic infection is crucial for the integrity of host innate and adaptive immunity.

Role of NO in Activation of $NF{\kappa}B$ by PM2.5 in Lung Epithelial Cells (PM2.5로 자극한 폐상피세포의 $NF{\kappa}B$ 활성화에 NO의 역할)

  • Kim, Kyoung-Ah;Nam, Hae-Yun;Mun, Je-Hyeok;Jeong, Jin-Sook;Lim, Young;Kai, Hirofumi
    • Tuberculosis and Respiratory Diseases
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    • v.52 no.6
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    • pp.616-626
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    • 2002
  • Background : The present study was performed to further improve our understanding of molecular mechanisms involved in the activation of NFkB, a major transcriptional factor involved in the inflammatory response in the lung, by particulate matter in lung epithelial cells with an aerodynamic diameter of less than $2.5{\mu}m$(PM2.5). Materials and Methods : Immediate production of reactive oxygen species (ROS) and nitrogen species (RNS), with the PM2.5 induced expression of inducible nitric oxide synthase (iNOS), $I{\kappa}B$ degradation and $NF{\kappa}B$-dependent transcriptional activity, in 549 cells, were monitored. Addition, we also examined the effect of the iNOS inhibitor, L-N6-(1-iminoethyl) lysine hydrochloride (L-NIL), on the PM2.5-induced $NF{\kappa}B$ activation in A549 cells. Results : The rapid degradation of $I{\kappa}B$ and the increase of transcriptional activity of the $NF{\kappa}B$-dependent promotor were observed in A549 cells exposed to PM2.5. The immediate production of ROS in response to PM2.5 in A549 cells was not clearly detected, although immediate responses were observed in RAW264.7 cells. A 549 cells, cultured in the presence of PM2.5, produced an increase in NO, which was noticeably significant after 15 min of exposure with the expression of iNOS mRNA. The addition of L-NIL, an iNOS inhibitor, significantly inhibited the PM2.5-induced $I{\kappa}B$ degradation and the increase of the $NF{\kappa}B$-dependent transcriptional activity. Conclusion : These results suggest that PM2.5 stimulates the immediate production of RNS, leading to the activation of $NF{\kappa}B$ in the pulmonary epithelium.

ROLE OF NF${\kappa}B$ IN TOLL-LIKE RECEPTOR 9-MEDIATED MATRIX METALLOPROTEINASE-9 EXPRESSION (Toll-like receptor 9-매개에 의한 matrix metalloproteinase-9 발현에서 NF${\kappa}B$의 역할)

  • Lee, Sang-Hoon;Chin, Byung-Rho;Baek, Suk-Hwan
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.33 no.6
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    • pp.636-642
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    • 2007
  • Background: CpG DNA plays an important role in immune cell function. This study examined whether the temporal control of toll-like receptor (TLR)9 by CpG DNA can regulate the expression of matrix metalloproteinase-9(MMP-9). Methods and materials: Macrophages were cultured in the presence of 10% FBS. For the various MMP genes analysis, RT-PCR and real-time PCR were performed. In addition, zymography assay performed for the MMP activity. The phosphorylation assay did for the ERK1/2 and NF${\kappa}B$ activation, and luciferase promoter assay was for the NF${\kappa}B$ activity. Results: CpG DNA induced the mRNA expression of MMP-2, MMP-9, and MMP-13, but not of MMP-7, MMP-8, and MMP-12, in a time-dependent manner. Especially, the mRNA expression of MMP-9 was strongly induced by CpG DNA using real-time RT-PCR. The TLR9 inhibitor, chloroquine, suppressed CpG DNA-induced MMP-9 expression and its activity. Moreover, CpG DNA induced the phosphorylation of ERK and the inhibition of ERK by U0126 suppressed CpG DNA-induced MMP-9 expression and its activity. CpG DNA stimulated $I{\kappa}B-{\alpha}$ degradation and luciferase activity. In addition, pretreatment of SN-50, the inhibitor of NF${\kappa}B$, strongly blocked the CpG DNA-induced MMP-9 expression and activity. Conclusion: These observations suggest that CpG DNA may play important roles in the activation of macrophages by regulating the production of MMP-9 via the sequential TLR9-ERK-NF${\kappa}B$ signaling pathway.

The Effect of $I{\kappa}B{\alpha}$-SR Gene Transfer on the Sensitivity of Human Lung Cancer Cell Lines to Cisplatin and Paclitaxel ($I{\kappa}B{\alpha}$-SR 유전자이입이 Cisplatin, Paclitaxel에 대한 폐암세포주의 감수성에 미치는 영향)

  • Lee, Seok-Young;Seol, Ja-Young;Park, Kyung-Ho;Park, Gun-Min;Hwang, Yong-Il;Kim, Cheol-Hyeon;Jang, Seung-Hun;Kwon, Sung-Youn;Yoo, Chul-Gyu;Kim, Young-Whan;Han, Sung-Koo;Shim, Young-Soo;Lee, Choon-Taek
    • Tuberculosis and Respiratory Diseases
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    • v.51 no.2
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    • pp.122-134
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    • 2001
  • Background : Some chemotherapeutic drugs induce NF-${\kappa}B$ activation by degrading the $I{\kappa}B{\alpha}$ protein in cancer cells which contributes to anticancer drug resistance. We hypothesized that inhibiting $I{\kappa}B{\alpha}$ degradation would block NF-${\kappa}B$ activation and result in increased tumor cell mortality in response to chemotherapy. Methods : The "superrepressor" form of the NF-${\kappa}B$ inhibitor was transferred by an adenoviral vector (Ad-$I{\kappa}B{\alpha}$-SR) to the human lung cancer cell lines (NCI H157 and NCI H460). With a MIT assay, the level of sensitization to cisplatin and paclitaxel were measured. To confirm the mechanism, an EMSA and Annexin V assay were performed. Results : EMSA showed that $I{\kappa}B{\alpha}$-SR effectively blocked the NF-${\kappa}B$ activation induced by cisplatin. Transduction with Ad-$I{\kappa}B{\alpha}$-SR resulted in an increased sensitivity of the lung cancer cell lines to cisplatin and paclitaxel by a factor of 2~3 in terms of $IC_{50}$. Annexin-V analysis suggests that this increment in chemosensitivity to cisplatin probably occurs through the induction of apoptosis. Conclusion : The blockade of chemotherapeutics induced NF-${\kappa}B$ activation by inducing Ad-$I{\kappa}B{\alpha}$-SR, increased apoptosis and increasing the chemosensitivity of the lung cancer cell lines tested, subsequently. Gene transfer of $I{\kappa}B{\alpha}$-SR appears to be a new therapeutic strategy of chemosensitization in lung cancer.

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Salicortin suppresses lipopolysaccharide-stimulated inflammatory responses via blockade of NF-κB and JNK activation in RAW 264.7 macrophages

  • Kwon, Dong-Joo;Bae, Young-Soo;Ju, Sung Mi;Youn, Gi Soo;Choi, Soo Young;Park, Jinseu
    • BMB Reports
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    • v.47 no.6
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    • pp.318-323
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    • 2014
  • We isolated the phenolic glucoside salicortin from a Populus euramericana bark extract, and examined its ability to suppress inflammatory responses as well as the molecular mechanisms underlying these abilities, using lipopolysaccharide (LPS)-stimulated RAW264.7 cells. Salicortin inhibited iNOS expression and the subsequent production of NO in a dose-dependent manner in the LPS-stimulated RAW 264.7 cells. Salicortin significantly suppressed LPS-induced signal cascades of NF-${\kappa}B$ activation, such as IKK activation, $I{\kappa}B{\alpha}$ phosphorylation and p65 phosphorylation in RAW 264.7 cells. In addition, salicortin inhibited the LPS-induced activation of JNK, but not ERK or p38 MAPK. Furthermore, salicortin significantly inhibited production of pro-inflammatory cytokines, such as TNF-${\alpha}$, IL-$1{\beta}$ and IL-6 in the LPS-stimulated RAW 264.7 cells. These findings suggest that salicortin may show its anti-inflammatory activity by suppressing the LPS-induced expression of pro-inflammatory mediators through inhibition of NF-${\kappa}B$ and JNK MAPK signaling cascades in macrophages.

The Effect of Homnis Placenta Herbal Acupuncture on Reducing Expression of LPS-induced Arthritis Model as an Anti-inflammatory Agent (자하차약침(紫何車藥針)의 항염증능(亢炎症能)이 LPS 유발 관절염(關節炎) 치료(治療)에 미치는 영향(影響))

  • Park, Ki-Bum;Baek, Seung-Tae;Lee, Seung-Deok;Kim, Kyung-Ho;Kim, Kap-Sung
    • Journal of Acupuncture Research
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    • v.23 no.6
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    • pp.103-115
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    • 2006
  • Objectives : Rheumatoid arthritis(RA) is a systemic & a chronic inflammatory autoimmune disease . A chronic , locally destructive inflammmatory reaction in human is examplified by the synovitis present in some connective tissue disorder. The presence of a number of cytokines, $TNF-{\alpha}$, iNOS & expression of nitric oxide, NF-kB p65 activation implies an important role of cellular immune response in RA inflammatory reaction. This study was designed to evaluate on the effects of the Homnis Placenta herbal acupuncture on EX-LE201 & ST 35 reducing expression of LPS-induced arthritis model in mice. Materials and Methods : Homnis Placenta herbal acupuncture was inserted into 10 rats induced rheumatoid arthritis. The acupunctures were injected into the EX-LE201 and ST35 points. Such indexes were measured the inhibition of inducible nitric oxide synthase(iNOS) expression, nitric oxide(NO) production in vitro experiment and Tumor Necrosis $Factor-{\alpha}(TNF-{\alpha})$ & Nuclear Factor kappa $B(NF-{\kappa}B)$ p65 activation, synovial hyperplasia, angiogenesis and fibrosis in synovial membrane of knee joint of mice in vivo experiment. Results : 1.Homnis Placenta Herbal acupuncture inhibited iNOS mRNA and NO in RAW 264.7 cell of LPS-induced rheumatoid arthritis in a dose dependent manner. 2.Homnis Placenta Herbal acupuncture also showed significant inhibition of $TNF-{\alpha}$ & $NF-{\kappa}B$ p65, activation, synovial hyperplasia, angiogenesis and fibrosis in synovial membrane of knee joint of mice. Conclusion : These results suggest that Homnis Placenta Herbal acupuncture has an therapeutic effects on LPS induced-rheumatoid arthritis by inhibiting $TNF-{\alpha}$ activation.

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Inhibition of COX-2 gene expression via $NF-{\kappa}B$ pathway by Ichungwhan (이정환의 $NF-{\kappa}B$ 활성화 기전을 통한 COX-2 저해 기전)

  • Son Myung-yong;Jeong Ji-Cheon
    • 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.

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Auranofin Downregulates Nuclear Factor-κB Activation via Nrf2-Independent Mechanism (오라노핀에 의한 nuclear factor κB 활성저해는 Nrf2 활성화와 무관한 기전에 의함)

  • Kim, Nam-Hoon;Park, Hyo-Jung;Kim, In-Sook
    • Journal of Life Science
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    • v.20 no.12
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    • pp.1772-1776
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    • 2010
  • Transcription factors Nrf2 and NF-${\kappa}B$ are important regulators of the innate immune response, and their cross-talks in inflammation have been reported. Previously, we demonstrated that gold(I)-compound auranofin, an inhibitor of NF-${\kappa}B$ signal, induced Nrf2 activation in human synovial cells and monocytic cells. To investigate whether the Nrf2 activation is involved in the mechanism of the auranofin-attenuated NF-${\kappa}B$ signaling, we examined the effects of Nrf2 knockdown on NF-${\kappa}B$ activation using rheumatic synovial cells. When the cells were transfected with a specific siRNA for Nrf2, the gene expression was perfectly blocked. However, the Nrf2 knockdown did not cancel the suppressive effect of auranofin on TNF-$\alpha$-induced $I{\kappa}B-{\alpha}$ degradation. Treatment with a specific siRNA for HO-1, which is a target of Nrf2 and plays a role in anti-inflammation, also did not affect the blocking activity of auranofin on $I{\kappa}B-{\alpha}$ degradation. In addition, auranofin-inhibited ICAM-1 expression was not restored by Nrf2 knockdown. These findings indicate that the activated Nrf2 and HO-1 are not associated with the suppressive action of auranofin on the pro-inflammatory cytokines-stimulated NF-${\kappa}B$ activation. This suggests that Nrf2/HO-1 and NF-${\kappa}B$ signals, which are regulated by auranofin, participate in the anti-inflammatory action of auranofin via independent pathways in rheumatic synovial cells.

Antiinflammatory Effect of Lactic Acid Bacteria: Inhibition of Cyclooxygenase-2 by Suppressing Nuclear Factor-${\kappa}B$ in Raw264.7 Macrophage Cells

  • Lee, Jeong-Min;Hwang, Kwon-Tack;Jun, Woo-Jin;Park, Chang-Soo;Lee, Myung-Yul
    • Journal of Microbiology and Biotechnology
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    • v.18 no.10
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    • pp.1683-1688
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    • 2008
  • Lactobacillus casei 3260 (L. casei 3260) was evaluated in relation to the inflammatory response mediated by lipopolysaccharide (LPS)-induced nuclear factor-${\kappa}B$ (NF-${\kappa}B$) and cyclooxygenase-2 (COX-2) expression in Raw264.7 macrophage cells. The treatment of Raw264.7 cells with L. casei 3260 significantly inhibited the secretion of tumor necrosis factor-$\alpha$ (TNF-$\alpha$) and prostaglandins $E_{2}\;(PGE_{2})$, followed by suppression of COX-2. To clarify the molecular mechanism, the inhibitory effect of L. casei 3260 on the NF-${\kappa}B$ signaling pathway was examined based on the luciferase reporter activity. Although the treatment of Raw264.7 cells with L. casei 3260 did not affect the transcriptional activity of NF-${\kappa}B$, it did inhibit NF-${\kappa}B$ activation, as determined by the cytosolic p65 release and degradation of I-${\kappa}B{\alpha}$. Therefore, these findings suggest that the suppression of COX-2 through inhibiting the NF-${\kappa}B$ activation by LPS may be associated with the antiinflammatory effects of L. casei 3260 on Raw264.7 cells.