• Title/Summary/Keyword: $NF-_{\kappa}B$

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HSV-1 ICP27 represses NF-κB activity by regulating Daxx sumoylation

  • Kim, Ji Ae;Choi, Mi Sun;Min, Jung Sun;Kang, Inho;Oh, Jeongho;Kim, Jin Chul;Ahn, Jeong Keun
    • BMB Reports
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    • v.50 no.5
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    • pp.275-280
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    • 2017
  • Herpes simplex virus type 1 ICP27 is a multifunctional protein responsible for viral replication, late gene expression, and reactivation from latency. ICP27 interacts with various cellular proteins, including Daxx. However, the role of interaction between ICP27 and Daxx is largely unknown. Since Daxx is known to repress $NF-{\kappa}B$ activity, there is a possibility that ICP27 may influence the inhibitory effect of Daxx on $NF-{\kappa}B$ activity. In this study, we tested whether ICP27 affects the $NF-{\kappa}B$ activity through its interaction with Daxx. Interestingly, ICP27 enhanced the Daxx-mediated repression of $NF-{\kappa}B$ activity. In addition, we found that sumoylation of Daxx regulates its interaction with p65. ICP27 binds to Daxx, inhibits Daxx sumoylation, and enhances p65 deacetylation induced by Daxx. Consequently, ICP27 represses the $NF-{\kappa}B$ activity, by elevating the inhibitory effect of Daxx on $NF-{\kappa}B$ activity through desumoylation of Daxx.

Effect of Bcl-2 on Apoptosis and Transcription Factor NF-κB Activation Induced by Adriamycin in Bladder Carcinoma BIU87 Cells

  • Zhang, Guo-Jun;Zhang, Zhe
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.4
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    • pp.2387-2391
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    • 2013
  • Resistance to apoptosis is a major obstacle preventing effective therapy for malignancies. Bcl-2 plays a significant role in inhibiting apoptosis. We reconstructed a stable human Bcl-2 transfected cell line, BIU87-Bcl-2, that was derived from the transfection of human bladder carcinoma cell line BIU87 with a plasmid vector containing recombinant Bcl-2 [pcDNA3.1(+)-Bcl-2]. A cell line transfected with the plasmid alone [pcDNA3.1(+)-neo] was also established as a control. BIU87 and BIU87-neo proved sensitive to adriamycin induced apoptosis, while BIU87-Bcl-2 was more resistant. In view of the growing evidence that NF-${\kappa}B$ may play an important role in regulating apoptosis, we determined whether Bcl-2 could modulate the activity of NF-${\kappa}B$ in bladder carcinoma cells. Stimulation of BIU87, BIU87-neo and BIU87-Bcl-2 with ADR resulted in an increase expression of NF-${\kappa}B$ (p<0.001). The expression of NF-${\kappa}B$ in BIU87-Bcl-2 was higher than in the other two cases, with a concomitant reduction in the $I{\kappa}B{\kappa}$ protein level. These results suggest that the overexpression of Bcl-2 renders human bladder carcinoma cells resistant to adriamycin-induced cytotoxicity and there is a link between Bcl-2 and the NF-${\kappa}B$ signaling pathway in the suppression of apoptosis.

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.

Globular Adiponectin Exerts a Pro-Inflammatory Effect via IκB/NF-κB Pathway Activation and Anti-Inflammatory Effect by IRAK-1 Downregulation

  • Lee, Kyoung-Hee;Jeong, Jiyeong;Woo, Jisu;Lee, Chang-Hoon;Yoo, Chul-Gyu
    • Molecules and Cells
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    • v.41 no.8
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    • pp.762-770
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    • 2018
  • Adiponectin, a hormone produced by adipose tissue, is very abundant in plasma, and its anti- and pro-inflammatory effects are reported. However, the mechanisms of these pro- and anti-inflammatory effects are not fully defined. Herein, we evaluated the dual inflammatory response mechanism of adiponectin in macrophages. Short-term globular adiponectin (gAd) treatment induced $I{\kappa}B{\alpha}$ degradation, $NF-{\kappa}B$ nuclear translocation, and $TNF-{\alpha}$ production in RAW 264.7 cells. Polymyxin B pretreatment did not block gAd-induced $I{\kappa}B{\alpha}$ degradation, and heated gAd was unable to degrade $I{\kappa}B{\alpha}$, suggesting that the effects of gAd were not due to endotoxin contamination. gAd activated IKK and Akt, and inhibition of either IKK or Akt by dominant-negative $IKK{\beta}$ ($DN-IKK{\beta}$) or DN-Akt overexpression blocked gAd-induced $I{\kappa}B{\alpha}$ degradation, suggesting that short-term incubation with gAd mediates inflammatory responses by activating the $I{\kappa}B/NF-{\kappa}B$ and PI3K/Akt pathways. Contrastingly, long-term stimulation with gAd induced, upon subsequent stimulation, tolerance to gAd, lipopolysaccharide, and CpG-oligodeoxynucleotide, which is associated with gAd-induced downregulation of IL-receptor-associated kinase-1 (IRAK-1) due to IRAK-1 transcriptional repression. Conclusively, our findings demonstrate that the pro- and anti-inflammatory responses to gAd in innate immune cells are time-dependent, and mediated by the activation of the $I{\kappa}B/NF-{\kappa}B$ pathway, and IRAK-1 downregulation, respectively.

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.

Effects of Polygoni Cuspidati Radix on the $H_2O_2$-treated LLC-$PK_1$ Cell's Redox Status and NF-${\kappa}B$ Signaling (호장근(虎杖根)이 $H_2O_2$에 노출된 LLC-$PK_1$ 세포의 Redox Status 및 NF-${\kappa}B$ Signaling에 미치는 영향)

  • Kim, Sol-Ri;Jeong, Ji-Cheon
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.26 no.4
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    • pp.483-490
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    • 2012
  • This study was designed to identify the effects of Polygoni cuspidati Radix(PCR) on the generation of superoxide anion radicals (${\cdot}O_2{^-}$), nitric oxide (NO), peroxynitrite ($ONOO^-$) in the renal epithelial cells of mouse(LLC-$PK_1$). The effects of PCR on the expression of inflammation-related proteins, IKK-${\alpha}$, phospho-$I{\kappa}B-{\alpha}$, NF-${\kappa}B$ (p50, p65), COX-2, iNOS, IL-$1{\beta}$, VCAM-1, were examined by western blotting. For this study, the fluorescent probes, namely dihydrorhodamine 123 (DHR 123), 2',7'-dichloro dihydrofluorescein diacetate (DCFDA), 4,5-diaminofluorescein (DAF-2) were used. Protein expression levels of IKK-${\alpha}$, phospho-$I{\kappa}B-{\alpha}$, NF-${\kappa}B$ (p50, p65), COX-2, iNOS, IL-$1{\beta}$, VCAM-1 were assayed by western blot. PCR reduced $H_2O_2$-induced cell death dose-dependently. It inhibited the generation of ${\cdot}O_2{^-}$, NO, $ONOO^-$ and $PGE^2$ in the $H_2O_2$-treated LLC-PK1 cells in vitro. PCR inhibited the espression of IKK-${\alpha}$, phospho-$I{\kappa}B-{\alpha}$, COX-2, iNOS, IL-$1{\beta}$ and VCAM-1 genes by means of decreasing the NF-${\kappa}B$ activation. These results suggest that PCR is an effective NO, ${\cdot}O_2{^-}$, $ONOO^-$ scavenger, and this substance recommended to be applied in treatment for the inflammatory process and inflammation-related disease.

The Effects of Lycium Chinense Milie on the $H_{2}O_{2}$-treated $LLC-PK_1$ Cell's Redox Status and $NF-{\kappa}B$Signaling (지골피(地骨皮)가 $H_{2}O_{2}$에 의한 $LLC-PK_1$ 세포의 Redox Status 및 $NF-{\kappa}B$ Signaling에 미치는 영향)

  • Choi, Gyu-Ho;Shin, Hyeon-Cheol
    • The Journal of Internal Korean Medicine
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    • v.30 no.1
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    • pp.36-50
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    • 2009
  • Objectives : This study was aimed to verify the cytoprotective function, antioxidative effect and inflammation genes inhibitory effects of Lycium chinense Milie. Therefore the generation of superoxide anion radical ( $O_2\;^-$), peroxynitrite ($ONOO^-$), nitric oxide (NO) and prostaglandin $E_2$ $(PGE_2)$ was investigated in the renal epithelial cells of mouse. Effects of Lycium chinense Milie on the expression of inflammation-related proteins, $IKK-{\alpha}$. $p-IKK-\alpha\beta$, $p-I{\kappa}B-\alpha$, $NF-{\kappa}B$ (p50, p65), COX-2 and iNOS, were examined by western blotting. Methods : For this study, the fluorescent probes were used, namely dihydrorhodamine 123 (DHR 123), 4.5-diaminofluorescein (DAF-2) and 2',7'-dichlorodihydrofluorescein diacetate (DCFDA). Western blotting was performed using anti-$IKK-\alpha$, anti-phospho $IKK-\alpha\beta$, anti-phospho $I{\kappa}B-\alpha$, anti-$NF-{\kappa}B$ (p50, p65), anti-COX-2 and anti-iNOS, respectively. Results : Lyciutn chinense Milie reduced $H_{2}O_{2}$-induced cell death dose-dependently. It inhibited the generation of $O_2\;^-$, $ONOO^-$, NO and $PGE_2$ in the $H_{2}O_{2}$-treated renal epithelial cells of mouse in vitro. Lycium chinense Milie inhibited the expression of $IKK-\alpha$, $p-IKK-\alpha\beta,\;p-I{\kappa}B-\alpha$, COX-2 and iNOS genes by means of decreasing activation of $NF-{\kappa}B$. Conclusions : According to above results. Lycium chinense Milie recommended to be applied in treatment for the inflammatory process and inflammation-related diseases.

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Paricalcitol attenuates indoxyl sulfate-induced apoptosis through the inhibition of MAPK, Akt, and NF-κB activation in HK-2 cells

  • Park, Jung Sun;Choi, Hoon In;Bae, Eun Hui;Ma, Seong Kwon;Kim, Soo Wan
    • The Korean journal of internal medicine
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    • v.34 no.1
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    • pp.146-155
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    • 2019
  • Background/Aims: Indoxyl sulfate (IS) is a uremic toxin and an important causative factor in the progression of chronic kidney disease. Recently, paricalcitol (19-nor-1,25-dihydroxyvitamin D2) was shown to exhibit protective effects in kidney injury. Here, we investigated the effects of paricalcitol treatment on IS-induced renal tubular injury. Methods: The fluorescent dye 2',7'-dichlorofluorescein diacetate was used to measure intracellular reactive oxygen species (ROS) following IS administration in human renal proximal tubular epithelial (HK-2) cells. The effects of IS on cell viability were determined using MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assays and levels of apoptosis-related proteins (Bcl-2-associated protein X [Bax] and B-cell lymphoma 2 [Bcl-2]), nuclear $factor-{\kappa}B$ ($NF-{\kappa}B$) p65, and phosphorylation of mitogen-activated protein kinase (MAPK) and protein kinase B (Akt) were determined by semiquantitative immunoblotting. The promoter activity of $NF-{\kappa}B$ was measured by luciferase assays and apoptosis was determined by f low cytometry of cells stained with f luorescein isothiocyanate-conjugated Annexin V protein. Results: IS treatment increased ROS production, decreased cell viability and induced apoptosis in HK-2 cells. IS treatment increased the expression of apoptosis-related protein Bax, decreased Bcl-2 expression, and activated phosphorylation of MAPK, $NF-{\kappa}B$ p65, and Akt. In contrast, paricalcitol treatment decreased Bax expression, increased Bcl-2 expression, and inhibited phosphorylation of MAPK, $NF-{\kappa}B$ p65, and Akt in HK-2 cells. $NF-{\kappa}B$ promoter activity was increased following IS, administration and was counteracted by pretreatment with paricalcitol. Additionally, flow cytometry analysis revealed that IS-induced apoptosis was attenuated by paricalcitol treatment, which resulted in decreased numbers of fluorescein isothiocyanate-conjugated Annexin V positive cells. Conclusions: Treatment with paricalcitol inhibited IS-induced apoptosis by regulating MAPK, $NF-{\kappa}B$, and Akt signaling pathway in HK-2 cells.

Sodium Salicylate Inhibits Expression of COX-2 Through Suppression of ERK and Subsequent $NF-{\kappa}B$ Activation in Rat Ventricular Cardiomyocytes

  • Kwon, Keun-Sang;Chae, Han-Jung
    • Archives of Pharmacal Research
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    • v.26 no.7
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    • pp.545-553
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    • 2003
  • The expression of cyclooxygenase-2 (COX-2) is a characteristic response to inflammation, which can be inhibited with sodium salicylate. IL-1$\beta$ and TNF-$\alpha$ can induce extracellular signal-regulated kinase (ERK), IKK, IkB degradation and NF-$\kappa$B activation. Salicylate inhibited the IL-1$\beta$ and TNF-$\alpha$-induced COX-2 expressions, regulated the activation of ERK, IKK and IkB degradation, and the subsequent activation of NF-$\kappa$B, in neonatal rat ventricular cardiomyocytes. The inhibition of the ERK pathway, with a selective inhibitor, PD098059, blocked the expressions of IL-1$\beta$ and TNF-$\alpha$-induced COX-2 and $PGE_2$ release. The antioxidant, N-acetyl-cysteine, also reduced the glutathione or catalase- attenuated COX-2 expressions in IL-1$\beta$ and TNF-$\alpha$-treated cells. This antioxidant also inhibited the activation of ERK and NF-$\kappa$B in neonatal rat cardiomyocytes. In addition, IL-1$\beta$ and TNF-$\alpha$-stimulated the release of reactive oxygen species (ROS) in the cardiomyocytes. However, salicylate had no inhibitory effect on the release of ROS in the DCFDA assay. The results showed that salicylate inhibited the activation of ERK and IKK, I$\kappa$B degradation and NF-$\kappa$B activation, independently of the release of ROS, which suggested that salicylate exerts its anti-inflammatory action through the inhibition of ERK, IKK, IkB and NF-$\kappa$B, and the resultant COX-2 expression pathway in neonatal rat ventricular cardiomyocytes.

Licochalcone B Exhibits Anti-inflammatory Effects via Modulation of NF-κB and AP-1

  • Kim, Jin-Kyung;Jun, Jong-Gab
    • Biomedical Science Letters
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    • v.21 no.4
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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.