• Title/Summary/Keyword: $I{\kappa}B$

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Role of PI3-Kinase/Akt Pathway in the Activation of Etoposide-Induced $NF-{\kappa}B$ Transcription Factor

  • Choi Yong-Seok;Park Heon-Yong;Jeong Sun-Joo
    • Journal of Microbiology and Biotechnology
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    • v.16 no.3
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    • pp.391-398
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    • 2006
  • $NF-{\kappa}B$ is a transcription factor involved in the innate immunity against bacterial infection and inflammation. It is also known to render cells resistant to the apoptosis caused by some anticancer drugs. Such a chemoresistance of cancer cells may be related to the activation of $NF-{\kappa}B$ transcription factor; however, the mechanism of activation is not well understood. Here, we demonstrate that a chemotherapeutic agent, etoposide, independently stimulates the $I{\kappa}B{\alpha}$ degradation pathway and PI3-kinase/Akt signaling pathway: The classical $I{\kappa}B{\alpha}$ degradation pathway leads to the nuclear translocation and DNA binding of p65 subunit through $IKK{\beta}$ kinase, whereas the PI3-kinase/Akt pathway plays a distinct role in activating this transcription factor. The PI3-kinase/Akt pathway acts on the p50 subunit of the $NF-{\kappa}B$ transcription factor and enhances the DNA binding affinity of the p50 protein. It may also explain the role of the PI3-kinase/Akt pathway in the anti-apoptotic function of $NF-{\kappa}B$ during chemoresistance of cancer cells.

Anti-inflammatory Effect of Red Ginseng through Regulation of MAPK in Lipopolysaccharide-stimulated RAW264.7 (Lipopolysaccharide로 유도된 RAW264.7 세포에서 MAPK에 의한 홍삼추출물의 항염증 효과)

  • Shin, Ji-Su;Kim, Jong-Myoung;An, Won-Gun
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.26 no.3
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    • pp.293-300
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    • 2012
  • Inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) are important inflammatory mediators implicated in pathogenesis of inflammation and certain types of human cancers. The present study was designed to determine whether Red Ginseng (RG) could modulate $I{\kappa}B$-kinase, iNOS and COX-2 gene expression and immune responses in RAW 264.7 macrophages stimulated with lipopolysaccharide (LPS). RG extract suppressed the expression of LPS-induced $I{\kappa}B$, iNOS, COX-2, and immune responses in a dose-dependent manner. It also showed an anti-inflammatory effect by inhibiting NF-${\kappa}B$ immune response induced by LPS treatment. Inhibitory effect of RG on LPS-induced inflammation was mediated by suppressed phosphorylation of ERK, JNK and p38 through the regulation of the mitogen-activated protein kinase (MAPK) pathway leading to a decreased production of NO, iNOS, COX-2 and NF-${\kappa}B$. The results implied the role of RG as an inflammation regulator and its possible application for curing inflammatory diseases.

Wogonin inhibits Cytokine-induced TARC/CCL17 Expression by Suppression of NF-${\kappa}B$ activation via p38 MAP kinase Signalning Pathways in HaCaT Keratinocytes

  • Jang, Seon-Il
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.21 no.4
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    • pp.1017-1024
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    • 2007
  • Thymus and activation-regulated chemokine (TARC/CCL-17), produced by keratinocytes, is a CC chemokine known to selectively Th2 type T cells via $CCR4^+$ and is implicated in the development of atopic dermatitis (AD). TARC/CCL17 expression was induced by cytokines such as tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) and interferon-${\gamma}$ (IFN-${\gamma}$). We recently found that the wogonin, a flavone isolated from Scutellaria baicalensis, suppressed TARC expression via heme oxygenase 1 (HO1) in human keratinocytes induced with mite antigen. However, little is known about the inhibitory mechanism of wogonin on TARC/CCL-17 expression stimulated with cytokines. To investigate the inhibitory mechanism, I determined the inhibitory effects of wogonin on the activation of nuclear factor-${\kappa}B$ (NF-${\kappa}B$) and $I{\kappa}B{\alpha}$ phosphorylation, and also examined the activation of p38 MAP kainase in HaCaT keratinocytes stimulated with TNF-${\alpha}$ and IFN-${\gamma}$. Wogonin inhibited NF-${\kappa}B$-DNA complex, NF-${\kappa}B$ binding activity, and the phosphorylation of $I{\kappa}B{\alpha}$ in a dose dependent manner. Wogonin also inhibited the translocation of NF-${\kappa}B$ from cytosol to nucleus. Moreover, the phosphorylation of of p38 MAP kinase in the TNF-${\alpha}$ and IFN-${\gamma}$-stimulated HaCaT keratinocytes were suppressed by wogonin in a dose dependent manner. These results suggest that wogonin may inhibit cytokine-induced NF-${\kappa}B$ activation by $I{\kappa}B{\alpha}$ degradation via suppression of p38 MAP kinase signaling pathway in keratinocytes and modulation of wogonin signaling pathway may be beneficial for the treatment of AD.

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.

Role of the Nuclear Transcription Factor NF-κB Caused by Acute Hypoxia in the Heart (급성 저산소증 상태에서 심장 내 전사인자 NF-κB의 기능)

  • Joo, Chan Uhng;Juhng, Woo Suk;Kim, Jae Cheol;Yi, Ho Keun
    • Clinical and Experimental Pediatrics
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    • v.45 no.9
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    • pp.1106-1113
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    • 2002
  • Purpose : Nuclear ($factor-{\kappa}BNF-{\kappa}B$) is now recognized as playing a potential role in programmed cell death and the adaptive response to various stress. Cellular hypoxia is a primary manifestation of many cardiovascular diseases. It seems that vascular endothelial growth factor (VEGF) and insulin like growth factor-I(IGF-I) have a function as a protective molecule in the heart against several stress including hypoxia. In this study, the role of $NF-{\kappa}B$ to the cellular response and regulation of protective molecules against the acute hypoxia in the heart was studied. Methods : To cause acute hypoxic stress to the heart, Sprague Dawley rats were exposed to hypoxic chamer($N_2$ 92% and $O_2$ 8%). After the hypoxic exposure, nuclear proteins, total proteins and mRNA were isolated from heart. Translocation of the transcription factors $NF-{\kappa}B$, NF-ATc, AP-1 and NKX-2.5 were evaluated by electrophoretic mobility shift assay(EMSA). The expression of IGF-I and VEGF were studied before and after the hypoxic stress by competitive-PCR, Northern hybridization and Western hybridization. To confirm the role of the $NF-{\kappa}B$ in the heart, the rats also were pretreated with diethyl-dithiocarbamic acid(DDTC) into peritoneal cavity to block $NF-{\kappa}B$ translocation into nucleus. Results : The expression of $NF-{\kappa}B$, AP-1 and NF-ATc were increased by the hypoxic stress. Increased expression of the VEGF and IGF-I were also observed by the hypoxic stress. However, the blocking of the $NF-{\kappa}B$ translocation reduced those expressions of VEGF and IGF-I. Conclusion : These results suggest that $NF-{\kappa}B$ has a protective role against the acute hypoxia through several gene expression, especially VEGF and IGF-I in heart muscle.

Atopic Dermatitis-Related Inflammation in Macrophages and Keratinocytes: The Inhibitory Effects of Bee Venom

  • Kim, Deok-Hyun;Song, Ho-Sueb
    • Journal of Acupuncture Research
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    • v.36 no.2
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    • pp.80-87
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    • 2019
  • Background: This study investigated the anti-inflammatory effects of bee venom (BV) through the inhibition of nuclear factor kappa beta ($NF-{\kappa}B$) expression in macrophages and keratinocytes. Methods: Cell viability assays were performed to investigate the cytotoxicity of BV in activated macrophages [lipopolysaccharide (LPS)] and keratinocytes [interferon-gamma/tumor necrosis factor-alpha ($IFN-{\gamma}/TNF-{\alpha}$)]. A luciferase assay was performed to investigate the cellular expression of $NF-{\kappa}B$ in relation to BV dose. The expression of $NF-{\kappa}B$ inhibitors ($p-I{\kappa}B{\alpha}$, $I{\kappa}B{\alpha}$, and p50 and p65) were determined by Western Blot analysis, and the electromobility shift assay. A nitrite quantification assay was performed to investigate the effect of BV, and $NF-{\kappa}B$ inhibitor on nitric oxide (NO) production in macrophages. In addition, Western Blot analysis was performed to investigate the effect of BV on the expression of mitogen-activated protein kinases (MAPK) in activated macrophages and keratinocytes. Results: BV was not cytotoxic to activated macrophages and keratinocytes. Transcriptional activity of $NF-{\kappa}B$, and p50, p65, and $p-I{\kappa}B{\alpha}$ expression was reduced by treatment with BV in activated macrophages and keratinocytes. Treatment with BV and an $NF-{\kappa}B$ inhibitor, reduced the production of NO by activated macrophages, and also reduced $NF-{\kappa}B$ transcriptional activity in activated keratinocytes (compared with either BV, or $NF-{\kappa}B$ inhibitor treatment). Furthermore, BV decreased p38, p-p38, JNK, and p-JNK expression in LPS-activated macrophages and $IFN-{\gamma}/TNF-{\alpha}$-activated keratinocytes. Conclusion: BV blocked the signaling pathway of $NF-{\kappa}B$, which plays an important role in the inflammatory response in macrophages and keratinocytes. These findings provided the possibility of BV in the treatment of atopic dermatitis.

Protein Kinase $C-{\alpha}$ Regulates Toll-like Receptor 4-Mediated Inducible Nitric Oxide Synthase Expression

  • Lee, Jin-Gu;Chin, Byung-Rho;Baek, Suk-Hwan
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.34 no.1
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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.

Immunohistochemical Study on the Inflammation-related Proteins in the Ankle Joint of Complete Freund's Adjuvant-injected Rat by Electroacupuncture Stimulation (전침에 의한 Complete Freund's Adjuvant유발 관절염모델의 거퇴관절 내 염증관련 단백질에 대한 면역조직화학적 연구)

  • Park, In-Bum;Choi, Byung-Tae;Ahn, Chang-Beohm
    • Journal of Acupuncture Research
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    • v.22 no.4
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    • pp.55-63
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    • 2005
  • 목적 : 만성 염증성 질환에 대한 전침효과를 알아보기 위해 complete Freund's adjuvant (CA) 유발 관절염 모델에서 염증관련 단백질의 변화를 살펴보았다. 방법 : Sprague-Dawley계 흰쥐의 족부에 CFA를 주사한 다음 3일 간격으로 2 Hz, 15 Hz 및 120 Hz 전침 자극을 주며 부종 형성여부를 plethysmometer로 측정하여 판정하였으며 30일 째 거퇴관절을 취하여 4% paraformaldehyde에 고정하고 EDTA용액에서 탈회시켜 파라핀연속 절편을 얻어 $NF-{\kappa}B$를 비롯한 5종의 염증관련 단백질의 발현을 면역조직화학적으로 살펴보았다. 결과 : 관절연골내 면역반응 중 연골기질은 반응이 없거나 약하고 연골세포는 $NF-{\kappa}Bp65,\;I-{\kappa}B{\alpha},\;iNOS$반응이 강하며 특히 유리연골층에서 더 현저하였으나 염증 및 전침자극에 따른 변화는 없었다. 관절낭에서 면역반응을 살펴보면 염증유발시 활액세포의 면역반응세포는 $I-{\kappa}B{\alpha}$가 감소한 반면 iNOS, $IL-1{\beta}$는 증가하며 특히 iNOS 증가가 현저하였으며 전침자극에 의해 iNOS가 감소하였다. 활액막조직에서 모든 면역반응이 증가하며 특히 $NF-{\kappa}Bp65,\;I-{\kappa}B{\alpha},\;iNOS$ 반응이 현저한데 전침자극에 의해 $IL-1{\beta}$를 제외한 모든 반응이 감소하였다. 결론 : 만성 염증성 동물모델의 거퇴관절 내 염증관련 단백질은 관절연골보다 관절낭에서 큰 변화를 보이며 전침처치에 의해 이들 단백질 발현이 억제되는 것으로 보아 전침이 만성 염증성 질환에 효과적임을 알 수 있다.

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Role of PI3K/Akt Pathway in the Activation of IκB/NF-κB Pathway in Lung Epithelial Cells (폐 상피세포에서 PI3K/Akt 경로가 IκB/NF-κB 경로의 활성화에 미치는 영향)

  • Lee, Sang-Min;Kim, Yoon Kyung;Hwang, Yoon-Ha;Lee, Chang-Hoon;Lee, Hee-Seok;Lee, Choon-Taek;Kim, Young Whan;Han, Sung Koo;Shim, Young-Soo;Yoo, Chul-Gyu
    • Tuberculosis and Respiratory Diseases
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    • v.54 no.5
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    • pp.551-562
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    • 2003
  • Background : NF-${\kappa}B$ is a characteristic transcriptional factor which has been shown to regulate production of acute inflammatory mediators and to be involved in the pathogenesis of many inflammatory lung diseases. There has been some evidence that PI3K/Akt pathway could activate NF-${\kappa}B$ in human cell lines. However, the effect of PI3K/Akt pathway on the activation of NF-${\kappa}B$ varied depending on the cell lines used in the experiments. In this study we evaluated the effect of PI3K/Akt pathway on the activation of NF-${\kappa}B$ in human respiratory epithelial cell lines. Methods : BEAS-2B, A549 and NCI-H157 cell lines were used in this experiment. To evaluate the activation of Akt activation and I${\kappa}B$ degradation, cells were analysed by western blot assay using phospho-specific Akt Ab and $I{\kappa}B$ Ab. To block PI3K/Akt pathway, cells were pretreated with wortmannin or LY294002 and transfected with dominant negative Akt (DN-Akt). For IKK activity, immune complex kinase assay was performed. To evaluate the DNA binding affinity and transcriptional activity of NF-${\kappa}B$, electrophoretic mobility shift assay (EMSA) and luciferase assay were performed, respectively. Results : In BEAS-2B, A549 and NCI-H157 cell lines, Akt was activated by TNF-$\alpha$ and insulin. Activation of Akt by insulin did not induce $I{\kappa}B{\alpha}$ degradation. Blocking of PI3K/Akt pathway via wortmannin/LY294002 or DN-Akt did not inhibit TNF-$\alpha$-induced $I{\kappa}B{\alpha}$ degradation or IKK activation. Inhibition of PI3K/Akt did not affect TNF-$\alpha$-induced NF-${\kappa}B$ activation. Overexpression of DN-Akt did not block TNF-$\alpha$-induced transcriptional activation of NF-${\kappa}B$, but wortmannin enhanced TNF-$\alpha$-induced in NF-${\kappa}B$ transcriptional activity. Conclusion : PI3K/Akt was not involved in TNF-$\alpha$-induced $I{\kappa}B{\alpha}$ degradation or transcriptional activity of NF-${\kappa}B$ in human respiratory epithelial cell lines.

Glatiramer acetate inhibits the activation of NFκB in the CNS of experimental autoimmune encephalomyelitis (Glatiramer acetate 투여에 의한 자가면역성 뇌척수염 마우스의 중추신경계에서의 NFκB 활성 억제)

  • Hwang, Insun;Ha, Danbee;Kim, Dae Seung;Joo, Haejin;Jee, Youngheun
    • Korean Journal of Veterinary Research
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    • v.51 no.3
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    • pp.217-225
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    • 2011
  • Glatiramer acetate (GA; Copaxone) has been shown to be effective in preventing and suppressing experimental autoimmune encephalomyelitis (EAE), the animal model of multiple sclerosis (MS). It has been recently shown that GA-reactive T cells migrate through the blood-brain barrier, accumulate in the central nervous system (CNS), secrete antiinflammatory cytokines and suppress production of proinflammatory cytokines of EAE and MS. Development of EAE requires coordinated expression of a number of genes involved in the activation and effector functions of inflammatory cells. Activation of inflammatory cells is regulated at the transcriptional level by several families of transcription factors. One of these is the nuclear factor kappa B ($NF{\kappa}B$) family which is present in a variety of cell types and involved in the activation of immune-relative genes during inflammatory process. Since it is highly activated at site of inflammation, $NF{\kappa}B$ activation is also implicated in the pathogenesis of EAE. In this study, we examined whether the inhibition of $NF{\kappa}B$ activation induced by GA can have suppressive therapeutic effects in EAE mice. We observed the expression of $NF{\kappa}B$ and phospho-$I{\kappa}B$ proteins increased in GA-treated EAE mice compared to EAE control groups. The immunoreactivity in inflammatory cells and glial cells of $NF{\kappa}B$ and phospho-$I{\kappa}B$ significantly decreased at the GA-treated EAE mice. These results suggest that treatment of GA in EAE inhibits the activation of $NF{\kappa}B$ and phophorylation of $I{\kappa}B$ in the CNS. Subsequently, the inhibition of $NF{\kappa}B$ activation and $I{\kappa}B$ phosphorylation leads to the anti-inflammatory effects thereby to reduce the progression and severity of EAE.