• Title/Summary/Keyword: NF-kB activation

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Luteolin and luteolin-7-O-glucoside inhibit lipopolysaccharide-induced inflammatory responses through modulation of NF-${\kappa}B$/AP-1/PI3K-Akt signaling cascades in RAW 264.7 cells

  • Park, Chung Mu;Song, Young-Sun
    • Nutrition Research and Practice
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    • v.7 no.6
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    • pp.423-429
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    • 2013
  • Luteolin is a flavonoid found in abundance in celery, green pepper, and dandelions. Previous studies have shown that luteolin is an anti-inflammatory and anti-oxidative agent. In this study, the anti-inflammatory capacity of luteolin and one of its glycosidic forms, luteolin-7-O-glucoside, were compared and their molecular mechanisms of action were analyzed. In lipopolysaccharide (LPS)-activated RAW 264.7 cells, luteolin more potently inhibited the production of nitric oxide (NO) and prostaglandin E2 as well as the expression of their corresponding enzymes (inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2) than luteolin-7-O-glucoside. The molecular mechanisms underlying these effects were investigated to determine whether the inflammatory response was related to the transcription factors, nuclear factor (NF)-${\kappa}B$ and activator protein (AP)-1, or their upstream signaling molecules, mitogen-activated protein kinases (MAPKs) and phosphoinositide 3-kinase (PI3K). Luteolin attenuated the activation of both transcription factors, NF-${\kappa}B$ and AP-1, while luteolin-7-O-glucoside only impeded NF-${\kappa}B$ activation. However, both flavonoids inhibited Akt phosphorylation in a dose-dependent manner. Consequently, luteolin more potently ameliorated LPS-induced inflammation than luteolin-7-O-glucoside, which might be attributed to the differentially activated NF-${\kappa}B$/AP-1/PI3K-Akt pathway in RAW 264.7 cells.

Blockade of p38 Mitogen-activated Protein Kinase Pathway Inhibits Interleukin-6 Release and Expression in Primary Neonatal Cardiomyocytes

  • Chae, Han-Jung;Kim, Hyun-Ki;Lee, Wan-Ku;Chae, Soo-Wan
    • The Korean Journal of Physiology and Pharmacology
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    • v.6 no.6
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    • pp.319-325
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    • 2002
  • The induction of interleukin-6 (IL-6) using combined proinflammatory agents $(LPS/IFN-{\gamma}\;or\;TNF-{\alpha}/IFN-{\gamma})$ was studied in relation to p38 mitogen-activated protein kinase (MAPK) and $NF-{\kappa}B$ transcriptional factor in primary neonatal cardiomyocytes. When added to cultures of cardiomyocytes, the combined agents $(LPS/IFN-[\gamma}\;or\;TNF-{\alpha}/IFN-{\gamma})$ had stimulatory effect on the production of IL-6 and the elevation was significantly reduced by SB203580, a specific p38 MAPK inhibitor. SB203580 inhibited protein production and gene expression of IL-6 in a concentration-dependent manner. In this study, $IFN-{\gamma}$ enhancement of $TNF-{\alpha}-induced\;NF-{\kappa}B$ binding affinity as well as p38 MAP kinase activation was observed. However, a specific inhibitor of p38 MAPK, SB203580, had no effect on $TNF-{\alpha}/IFN-{\gamma}\;or\;LPS/IFN-{\gamma}-induced\;NF-{\kappa}B$ activation. This study strongly suggests that these pathways about $TNF-{\alpha}/IFN-{\gamma}$ or $LPS/IFN-{\gamma}-activated$ IL-6 release can be primarily dissociated in primary neonatal cardiomyocytes.

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.

Effect of trichostatin A on NF-κB DNA binding activity and myogenesis in C2Cl2 skeletal muscle Precursor cell (C2C12 근육아세포에서 trichostatin A에 의한 NF-κB DNA 결합 활성과 근육발생에 미치는 영향)

  • 임운기;김경창;신혜자
    • Journal of Life Science
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    • v.12 no.1
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    • pp.55-60
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    • 2002
  • The differentiation of skeletal muscle precursor cells in culture is marked by the transcriptional activation of muscle-specific genes and the morphological differentiation of myoblast into multinucleate myotube. In this study, we examined the effect of TSA (Trichostatin A) on WF-kB DNA binding activity and muscle cell fusion in the process of myogenesis. Under TSA treatment, C2C12 myoblast could not fuse to myotube and its NF-kB DNA binding activity was also blocked. To investigate whether these phenomenons were affected by TSA in direct or not, differentiation media (DM) used to differentiate cells without TSA was concentrated and added to C2C12 myoblast with TSA simultaneously. C2C12 myoblast was fused to myotube and NF-kB DNA binding activity was recovered. These results suggest that TSA affects on the differentiation of myoblast, perhaps through several factors, by inhibiting myoblst fusion and blocking NF-kB DNA binding activity.

Therapeutic Effects of Cheonggisan Extract on Th2 cell differentiation and $NF-kB$ p65 activation (청기산(淸肌散)이 Th2 세포 분화와 염증에 미치는 영향)

  • Ku, Young-Hui;Hong, Seung-Ug
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.20 no.3
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    • pp.63-70
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    • 2007
  • Objectives : Atopic dermatitis is a recurrent or chronic eczematous skin disease with severe pruritus. Although the pathogenic mechanisms of atopic dermatitis are yet unknown, recently hyperresponsive Th2 cells in the acute phase are reported as the important mechanisms. Cheonggisan(CGS) is used in oriental clinics for curing acute skin lesions of eczema, atopic dermatitis or urticaria. There have been no studies on the therapeutic mechanism of CGS for curing atopic dermatitis. We aimed to find out the therapeutic mechanism of CGS on atopic dermatitis, so we observed Th2 cell differentiation in EL 4 cells and $NF-kB$ p65 activation in RAW 264.7 cells. Materials and Methods : EL 4 cells were induced the increase of IL-4 mRNA expression by phorbol-12-myristate-13-acetate(PMA) and 4-tert-Octylphenol(OP) and treated with CGS extract. RAW 264.7 cells were induced the increase of cyclooxygenase(COX)-2 mRNA expression by lipopolysaccharide(LPS) and treated with CGS extract. Results : The PMA and OP induced IL-4 mRNA expression was dose-dependantly decreased in CGS treated EL 4 cells. The LPS-induced COX-2 mRNA expression was dose-dependantly decreased in CGS treated RAW 264.7 cells. Conclusion : The results may suggest that the CGS inhibits Th2 cell differentiation in EL 4 cells and inhibits $NF-kB$ p65 activation in RAW 264.7 cells.

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Parthenolide Suppresses the Expression of Cyclooxygenase-2 and Inducible Nitric Oxide Synthase Induced by Toll-Like Receptor 2 and 4 Agonists

  • Lee, A-Neum;Park, Se-Jeong;Yun, Sae-Mi;Lee, Mi-Young;Son, Bu-Soon;Youn, Hyung-Sun
    • Biomedical Science Letters
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    • v.16 no.1
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    • pp.39-45
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    • 2010
  • Toll-like receptors (TLRs), which are pattern recognition receptors (PRRs), recognize pathogen-associated molecular patterns (PAMPs) and regulate the activation of innate immunity. All TLR signaling pathways culminate in the activation of NF-${\kappa}B$, leading to the induction of inflammatory gene products such as cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS). Parthenolide, a sesquiterpene lactone isolated from the herb feverfew (Tanacetum parthenium), has been used as folk remedies to treat many chronic diseases for many years. In the present report, we present biochemical evidence that parthenolide inhibits the NF-${\kappa}B$ activation induced by TLR agonists and the overexpression of downstream signaling components of TLRs, MyD88, $IKK{\beta}$, and p65. Parthenolide also inhibits TLR agonists-induced COX-2 and iNOS expression. These results suggest that parthenolide can modulate the immune responses regulated by TLR signaling pathways.

Inhibitory effect of Petalonia binghamiae on neuroinflammation in LPS-stimulated microglial cells (LPS에 의해 활성화된 미세아교세포에서 미역쇠 추출물의 신경염증 보호 효과)

  • Park, Jae Hyeon;Kim, Sung Hun;Lee, Sun Ryung
    • Journal of Nutrition and Health
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    • v.50 no.1
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    • pp.25-31
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    • 2017
  • Purpose: Neuroinflammation is mediated by activation of microglia implicated in the pathogenesis of neurodegenerative disorders such as Alzheimer's disease and Parkinson's disease. Inhibition of neuroinflammation may be an effective solution to treat these brain disorders. Petalonia binghamiae is known as a traditional food, based on multiple biological activities such as anti-oxidant and anti-obesity. In present study, the anti-neuroinflammatory potential of Petalonia binghamiae was investigated in LPS-stimulated BV2 microglial cells. Methods: Cell viability was measured by MTT assay. Production of nitric oxide (NO) was examined using Griess reagent. Expression of inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2) was detected by Western blot analysis. Activation of nuclear factor ${\kappa}B$ ($NF-{\kappa}B$) signaling was examined by nuclear translocation of $NF-{\kappa}B$ p65 subunit and phosphorylation of $I{\kappa}B$. Results: Extract of Petalonia binghamiae significantly inhibited LPS-stimulated NO production and iNOS/COX-2 protein expression in a dose-dependent manner without cytotoxicity. Pretreatment with Petalonia binghamiae suppressed LPS-induced $NF-{\kappa}B$ p65 nuclear translocation and phosphorylation of $I{\kappa}B$. Co-treatment with Petalonia binghamiae and pyrrolidine duthiocarbamate (PDTC), an $NF-{\kappa}B$ inhibitor, reduced LPS-stimulated NO release compared to that in PB-treated or PDTC-treated cells. Conclusion: The present results indicate that extract of Petalonia binghamiae exerts anti-neuroinflammation activities, partly through inhibition of $NF-{\kappa}B$ signaling. These findings suggest that Petalonia binghamiae might have therapeutic potential in relation to neuroinflammation and neurodegenerative diseases.

The Anti-inflammatory Mechanism of the Peel of Zanthoxylum piperitum D.C. is by Suppressing NF-κB/Caspase-1 Activation in LPS-Induced RAW264.7 Cells

  • Choi, Yun-Hee;Myung, Noh-Yil
    • Korean Journal of Plant Resources
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    • v.32 no.6
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    • pp.669-676
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    • 2019
  • Zanthoxylum piperitum D.C. (ZP) peels has been used as a natural spice and herb medicine for hypertension reduction, for strokes, and for its anti-bacterial and anti-oxidant activity. However, the anti-inflammatory mechanisms employed by ZP have yet to be completely understood. In this study, we elucidate the anti-inflammatory mechanism of ZP in lipopolysaccharide (LPS)-induced RAW264.7 cells. We evaluated the effects of ZP in LPS-induced levels of inflammatory cytokines, prostaglandin E2 (PGE2), and caspase-1 using ELISA. The expression levels of inflammatory-related genes, including cyclooxygenase (COX)-2 and inducible nitric oxide synthase (iNOS), were assayed by Western blot analysis. We elucidated the effect of ZP on nuclear factor (NF)-κB activation by means of a luciferase activity assay. The findings of this study demonstrated that ZP inhibited the production of inflammatory cytokine and PGE2 and inhibited the increased levels of COX-2 and iNOS caused by LPS. Additionally, we showed that the anti-inflammatory effect of ZP arises by suppressing the activation of NF-κB and caspase-1 in LPS- induced RAW264.7 cells. These results provide novel insights into the pharmacological actions of ZP as a potential candidate for development of new drugs to treat inflammatory diseases.

Study on Transcriptional Factors Activation Change of HL-60 cell Apoptosis by Hedyotis Diffusa's Methanol Extract (백화사설초 메탄올 추출물에 의한 HL-60 세포고사과정에 있어서의 transcriptional factors 활성변화 연구)

  • Park, Sang-Goo;Lee, Ji-Hyun;Moon, Gu;Moon, Suk-Jae;Won, Jin-Hee;Park, Lae-Gil
    • THE JOURNAL OF KOREAN ORIENTAL ONCOLOGY
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    • v.6 no.1
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    • pp.67-79
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    • 2000
  • Objective : Hedyotis diffusa has been used as an anticancer agent for several decades in oriental medicine. We test whether the methanol extract of the herb affects transcriptional activation factors including $NF-{\kappa}B$ and AP-1. Methods : 1. HL-60 cells were treated with various concentrations(from 200 to $50{\mu}g/ml$) of methanol extract and $H_2O$ extract($200{\mu}g/ml$)of hedyotis diffusa, After 48h later, the cells were tested for viability by MTT assay. 2. The HL-60 cells were treated with $200{\mu}g/ml$ of methanol extract for the indicated periods. First. Nuclear extracts were isolated and incubated with oligonucleotide probe of $NF-{\kappa}B$ and AP-1. Second. Nuclear extracts were isolated and reacted with p50, p65. c-rel pan-Jun, c-Jun, JunB. JunD antibody on ice for 30min. Finally The cell lysates were prepared and analyzed by western blotting using anti-Fas, anti-FasL and anti-p53 antibody. Results : 1. The methanol extract decreases the viability of human lymphoid origin leukemia HL-60 cells in a dose-dependent manner. 2. $NF-{\kappa}B$ is rapidly activated by the addition of the methanol extract, reaches a peak at 30min and gradually returns to resting level. We confirm that $NF-{\kappa}B$ is a heterodimer mainly composed of p65 subunit with c-Rel. 3. Transcriptional activation of AP-1 is detected at 30min and reaches a maximum at 1hr after stimulation of the cells with the methanol extract. AP-1 is mainly composed with Jur-D and partially Jug-B proteins. 4. the methanol extract of Hedyotis diffusa induces the expression of Fas, Fas ligand and p53 proteins of HL-60 cells in a time dependent fashion. Conclusions : These results suggest that the methanol extract of Hedyotis diffusa exerts anticancer effects to induce the death of human leukomic HL-60 cells via activation of trascriptional factors such as $NF-{\kappa}B$ and AP-1, increase in expression of Fas mediated signalling proteins, and induction of tumor suppressor gene. p53.

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PKCθ-Mediated PDK1 Phosphorylation Enhances T Cell Activation by Increasing PDK1 Stability

  • Kang, Jung-Ah;Choi, Hyunwoo;Yang, Taewoo;Cho, Steve K.;Park, Zee-Yong;Park, Sung-Gyoo
    • Molecules and Cells
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    • v.40 no.1
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    • pp.37-44
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    • 2017
  • PDK1 is essential for T cell receptor (TCR)-mediated activation of $NF-{\kappa}B$, and PDK1-induced phosphorylation of $PKC{\theta}$ is important for TCR-induced $NF-{\kappa}B$ activation. However, inverse regulation of PDK1 by $PKC{\theta}$ during T cell activation has not been investigated. In this study, we found that $PKC{\theta}$ is involved in human PDK1 phosphorylation and that its kinase activity is crucial for human PDK1 phosphorylation. Mass spectrometry analysis of wild-type $PKC{\theta}$ or of kinase-inactive form of $PKC{\theta}$ revealed that $PKC{\theta}$ induced phosphorylation of human PDK1 at Ser-64. This $PKC{\theta}$-induced PDK1 phosphorylation positively regulated T cell activation and TCR-induced $NF-{\kappa}B$ activation. Moreover, phosphorylation of human PDK1 at Ser-64 increased the stability of human PDK1 protein. These results suggest that Ser-64 is an important phosphorylation site that is part of a positive feedback loop for human PDK1-$PKC{\theta}$-mediated T cell activation.