• Title/Summary/Keyword: NF-$\kappa$B

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Inhibition of $NF-{\kappa}B$ Activation Increases Oxygen-Glucose Deprivation-Induced Cerebral Endothelial Cell Death

  • Lee, Jin-U;Kim, Chul-Hoon;Shim, Kyu-Dae;Ahn, Young-Soo
    • The Korean Journal of Physiology and Pharmacology
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    • v.7 no.2
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    • pp.65-71
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    • 2003
  • Increasing evidences suggest that ischemia-induced vascular damage is an integral step in the cascade of the cellular and molecular events initiated by cerebral ischemia. In the present study, employing a mouse brain endothelioma-derived cell line, bEnd.3, and oxygen-glucose deprivation (OGD) as an in vitro stroke model, the role of nuclear factor kappa B (NF-${\kappa}B$) activation during ischemic injury was investigated. OGD was found to activate NF-${\kappa}B$ and to induce bEnd.3 cell death in a time-dependent manner. OGD phosphorylated neither 32 Ser nor 42 Tyr of $I{\kappa}B{\alpha}$. OGD did not change the amount of $I{\kappa}B{\alpha}$. The extents of OGD-induced cell death after 8 h, 10 h, 12 h and 14 h of OGD were 10%, 35%, 60% and 85%, respectively. Reperfusion following OGD did not cause additional cell death, indicating no reperfusion injury after ischemic insult in cerebral endothelial cells. Three known as NF-${\kappa}B$ inhibitors, including pyrrolidine dithiocarbamate (PDTC) plus zinc, aspirin and caffeic acid phenethyl ester (CAPE), inhibited OGD-induced NF-${\kappa}B$ activation and increased OGD-induced bEnd.3 cell death in a dose dependent manner. There were no changes in the protein levels of bcl-2, bax and p53 which are modulated by NF-${\kappa}B$ activity. These results suggest that NF-${\kappa}B$ activation might be a protective mechanism for OGD-induced cell death in bEnd.3.

NF-${\kappa}B$ Activation in T Helper 17 Cell Differentiation

  • Park, Sang-Heon;Cho, Gabi;Park, Sung-Gyoo
    • IMMUNE NETWORK
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    • v.14 no.1
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    • pp.14-20
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    • 2014
  • CD28/T cell receptor ligation activates the NF-${\kappa}B$ signaling cascade during CD4 T cell activation. NF-${\kappa}B$ activation is required for cytokine gene expression and activated T cell survival and proliferation. Recently, many reports showed that NF-${\kappa}B$ activation is also involved in T helper (Th) cell differentiation including Th17 cell differentiation. In this review, we discuss the current literature on NF-${\kappa}B$ activation pathway and its effect on Th17 cell differentiation.

Brazilin Inhibits of TPA-induced MMP-9 Expression Via the Suppression of NF-${\kappa}B$ Activation in MCF-7 Human Breast Carcinoma Cells

  • Kim, Byeong-Soo
    • Journal of Food Hygiene and Safety
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    • v.25 no.3
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    • pp.209-214
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    • 2010
  • Metastasis is the primary cause of from breast cancer mortality. Cell migration and invasion play important roles in neoplastic metastasis. Matrix metalloproteinase-9 (MMP-9), which degrades the extracellular matrix (ECM), plays an important role in cancer cell invasion. NF-${\kappa}B$ is transcription factor important in the regulation of MMP-9, as the promoter of MMP-9 gene contains binding sites for NF-${\kappa}B$. Brazilin, an active component of sappan wood (Caesalpinia sappan), decreases TPA-induced MMP-9 expression and invasion in MCF-7 cells. Also, brazilin suppressed NF-${\kappa}B$ activation in TPA-treated MCF-7 cells. Taken together, we demonstrated that the inhibition of TPA-induced MMP-9 expression and cell invasion by brazilin is mediated by the suppression of the NF-${\kappa}B$ pathway in MCF-7 cells. This result suggest brazilin provide a potential therapeutic app roach for the treatment of breast cancer.

Structure Activity Relationship of Methylchroman-2-carboxylic Acid N-(Disubstituted)phenylamide Derivatives as Potential NF-${\kappa}B$ Inhibitors (메틸크로만-2-카르복실산 N-(이치환)페닐아마이드 유도체의 NF-${\kappa}B$ 저해 구조-활성 상관 관계)

  • Kim, Tae-Jeong;Kwak, Jae-Hwan;Kim, Young-Soo;Jung, Jae-Kyung;Lee, Hee-Soon
    • YAKHAK HOEJI
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    • v.55 no.2
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    • pp.154-159
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    • 2011
  • During the search for a novel compound that can inhibit NF-${\kappa}B$ activation, 6-hydroxy-7-methoxychroman-2-carboxylic acid phenyl amide (KL-1156) was identified as a good inhibitor of NF-${\kappa}B$ activation. In the present study, we describe the synthesis of methylchroman-2-carboxylic acid N-(disubstituted)phenylamide derivatives (1 and 2 serieses). In addition, their inhibitory effects of NF-${\kappa}B$ are compared with activity of KL-1156 and SAR (structure activity relationship) are explored.

NF-${\kappa}B$ Inhibitor Suppresses Hypoxia-induced Apoptosis of Mouse Pancreatic ${\beta}$-cell Line MIN6

  • Koh, Hyun Sook;Kim, Jae Young
    • Biomedical Science Letters
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    • v.20 no.1
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    • pp.14-24
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    • 2014
  • Hypoxia is one of the main reasons for islet apoptosis after transplantation as well as during isolation. In this study, we attempted to determine the potential usefulness of NF-${\kappa}B$ inhibitor for suppression of hypoxia-induced ${\beta}$-cell apoptosis as well as the relationship between IP-10 induction and ${\beta}$-cell apoptosis in hypoxia. To accomplish this, we cultured the mouse pancreatic ${\beta}$-cell line MIN6 in hypoxia (1% $O_2$). Among several examined chemokines, only IP-10 mRNA expression was induced under hypoxia, and this induced IP-10 expression was due to NF-${\kappa}B$ activity. Since a previous study suggested that IP-10 mediates ${\beta}$-cell apoptosis, we measured hypoxia-induced IP-10 protein and examined the effect of anti-IP-10 neutralizing Ab on hypoxia-induced ${\beta}$-cell apoptosis. However, IP-10 protein was not detected, and anti-IP-10 neutralizing Ab did not rescue hypoxia-induced MIN6 apoptosis, indicating that there is no relationship between hypoxia-induced IP-10 mRNA expression and hypoxia-induced ${\beta}$-cell apoptosis. Since it was still not clear if NF-${\kappa}B$ functions as an apoptotic or anti-apoptotic mediator in hypoxia-induced ${\beta}$-cell apoptosis, we examined possible involvement of NF-${\kappa}B$ in hypoxia-induced ${\beta}$-cell apoptosis. Treatment with 1 ${\mu}M$ NF-${\kappa}B$ inhibitor suppressed hypoxiainduced apoptosis by more than 50%, while 10 ${\mu}M$ AP-1 or 4 ${\mu}M$ NF-AT inhibitor did not, indicating involvement of NF-${\kappa}B$ in hypoxia-induced ${\beta}$-cell apoptosis. Overall, these results suggest that IP-10 is not involved in hypoxia-induced ${\beta}$-cell apoptosis, and that NF-${\kappa}B$ inhibitor can be useful for ameliorating hypoxia-induced ${\beta}$-cell apoptosis.

Hepatitis Delta Virus Large Antigen Sensitizes to TNF-α-Induced NF-κB Signaling

  • Park, Chul-Yong;Oh, Sang-Heun;Kang, Sang Min;Lim, Yun-Sook;Hwang, Soon B.
    • Molecules and Cells
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    • v.28 no.1
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    • pp.49-55
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    • 2009
  • Hepatitis delta virus (HDV) infection causes fulminant hepatitis and liver cirrhosis. To elucidate the molecular mechanism of HDV pathogenesis, we examined the effects of HDV viral proteins, the small hepatitis delta antigen (SHDAg) and the large hepatitis delta antigen (LHDAg), on $NF-{\kappa}B$ signaling pathway. In this study, we demonstrated that $TNF-{\alpha}-induced$ $NF-{\kappa}B$ transcriptional activation was increased by LHDAg but not by SHDAg in both HEK293 and Huh7 cells. Furthermore, LHDAg promoted TRAF2-induced $NF-{\kappa}B$ activation. Using coimmunoprecipitation assays, we demonstrated that both SHDAg and LHDAg interacted with TRAF2 protein. We showed that isoprenylation of LHDAg was not required for the increase of $NF-{\kappa}B$ activity. We further showed that only LHDAg but not SHDAg increased the $TNF-{\alpha}-mediated$ nuclear translocation of p65. This was accomplished by activation of $I{\kappa}B_{\alpha}$ degradation by LHDAg. Finally, we demonstrated that LHDAg augmented the COX-2 expression level in Huh7 cells. These data suggest that LHDAg modulates $NF-{\kappa}B$ signaling pathway and may contribute to HDV pathogenesis.

Tolfenamic Acid Suppresses Inflammatory Stimuli-Mediated Activation of NF-κB Signaling

  • Shao, Hong Jun;Lou, Zhiyuan;Jeong, Jin Boo;Kim, Kui Jin;Lee, Jihye;Lee, Seong-Ho
    • Biomolecules & Therapeutics
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    • v.23 no.1
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    • pp.39-44
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    • 2015
  • Tolfenamic acid (TA) is a traditional non-steroid anti-inflammatory drug (NSAID) and has been broadly used for the treatment of migraines. Nuclear factor kappa B (NF-${\kappa}B$) is a sequence-specific transcription factor and plays a key role in the development and progression of inflammation and cancer. We performed the current study to investigate the underlying mechanisms by which TA suppresses inflammation focusing on NF-${\kappa}B$ pathway in TNF-${\alpha}$ stimulated human normal and cancer cell lines and lipopolysaccharide (LPS)-stimulated mouse macrophages. Different types of human cells (HCT116, HT-29 and HEK293) and mouse macrophages (RAW264.7) were pre-treated with different concentrations of TA and then exposed to inflammatory stimuli such as TNF-${\alpha}$ and LPS. Transcriptional activity of NF-${\kappa}B$, $l{\kappa}B-{\alpha}$-degradation, p65 translocation and mitogen-activated protein kinase (MAPK) activations were measured using luciferase assay and Western blots. Pre-treatment of TA repressed TNF-${\alpha}$- or LPS-stimulated NF-${\kappa}B$ transactivation in a dose-dependent manner. TA treatment reduced degradation of $l{\kappa}B-{\alpha}$ and subsequent translocation of p65 into nucleus. TA significantly down-regulated the phosphorylation of c-Jun N-terminal kinase (JNK). However, TA had no effect on NF-${\kappa}B$ signaling and JNK phosphorylation in HT-29 human colorectal cancer cells. TA possesses anti-inflammatory activities through suppression of JNK/NF-${\kappa}B$ pathway in different types of cells.

Gliotoxin from the marine fungus Aspergillus fumigatus induces apoptosis in HT1080 fibrosarcoma cells by downregulating NF-κB

  • Kim, Young-Sang;Park, Sun Joo
    • Fisheries and Aquatic Sciences
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    • v.19 no.9
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    • pp.35.1-35.6
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    • 2016
  • Gliotoxin has been recognized as an immunosuppressive agent for a long time. Recently, it was reported to have antitumor properties. However, the mechanisms by which it inhibits tumors remain unclear. Here, we showed that gliotoxin isolated from the marine fungus Aspergillus fumigatus inhibited proliferation and induced apoptosis in HT1080 human fibrosarcoma cells. Gliotoxin repressed phosphorylation-dependent degradation of $I{\kappa}B-{\alpha}$, an antagonist of nuclear factor kappa B ($NF-{\kappa}B$), which is a known tumor-promoting factor. This coincided with a decrease in nuclear import of $NF-{\kappa}B$, suggesting its signaling activity was impaired. Moreover, gliotoxin increased intracellular reactive oxygen species (ROS). Since ROS have been known to inhibit $NF-{\kappa}B$, this may also contribute to gliotoxin's antitumorigenic effects. These results suggest that gliotoxin suppressed the activation of $NF-{\kappa}B$ by inhibiting phosphorylation and degradation of $I{\kappa}B-{\alpha}$ and by increasing ROS, which resulted in apoptosis of HT1080 cells. Cumulatively, gliotoxin is a promising candidate antagonist of $NF-{\kappa}B$, and it should be investigated for its possible use as a selective inhibitor of human fibrosarcoma cells.

Downregulation of $\textrm{NF}_{-{\kappa}}\textrm{B}$ activation in human keratinocytes by melanogenic inhibitors

  • Ahn, Kwang-Seok;Lee, Jinseon;Kim, Yeong-Shik
    • Proceedings of the SCSK Conference
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    • 2003.09a
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    • pp.780-803
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    • 2003
  • Exposure of skin cells, particularly keratinocytes to various nuclear factor-kappaB ($\textrm{NF}_{-{\kappa}}\textrm{B}$) activators [e.g. tumor necrosis factor-$\alpha$, interleukin-1, lipopolysaccharides, and ultraviolet light] leads to phosphorylation and degradation of the inhibitory protein, $\textrm{I}_{{\kappa}}\textrm{B}$. Liberated $\textrm{NF}_{-{\kappa}}\textrm{B}$ is translocated into the nucleus where it can change or alter expression of target genes, resulting in the secretion of extracellular signaling molecules including melanotrophic factors affecting melanocyte. In order to demonstrate the possible role of $\textrm{NF}_{-{\kappa}}\textrm{B}$ activation on the synthesis of melanotrophic factors from the keratinocytes, the activities of $\textrm{NF}_{-{\kappa}}\textrm{B}$ induced by melanogenic inhibitors (MIs) were determined in human HaCaT keratinocytes transfected with $\textrm{pNF}_{-{\kappa}}\textrm{B}$-SEAP-NPT plasmid. Transfectant cells released the secretory alkaline phosphatase (SEAP) as a transcription reporter in response to the $\textrm{NF}_{-{\kappa}}\textrm{B}$ activity and contain the neomycin phosphotransferase (NPT) gene for the dominant selection marker for geneticin resistance. MIs such as niacinamide, kojic acid, hydroquinone, resorcinol, arbutin, and glycolic acid were preincubated with transfectant HaCaT cells for 3 h and then ultraviolet B (UVB) was irradiated. $\textrm{NF}_{-{\kappa}}\textrm{B}$ activation was measured with the SEAP reporter gene assay using a fluorescence detection method. Of the Mis tested, kojic acid ($IC_{50}$/ = 60 $\mu$M) was found to be the most potent inhibitor of UVB-upregulating $\textrm{NF}_{-{\kappa}}\textrm{B}$ activation in transfectant HaCaT cells, which is followed by niacinamide ($IC_{50}$/= 540 $\mu$M). Pretreatment of the transfectant HaCaT cells with the Mis, especially kojic acid and niacinamide, effectively lowered $\textrm{NF}_{-{\kappa}}\textrm{B}$ binding measured by electrophoretic mobility shift assay. Furthermore, these two inhibitors remarkably reduced the secretion level of IL-6, one of melanotrophic factors, triggered by UV-radiation of the HaCaT cells. These observations suggest that Mis working at the in vivo level might act partially through the modulation of the synthesis of melanotrophic factors in keratinocyte.

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Intra-Spinal Bone Marrow Mononuclear Cells Transplantation Inhibits the Expression of Nuclear Factor-${\kappa}B$ in Acute Transection Spinal Cord Injury in Rats

  • Shrestha, Rajiv Prasad;Qiao, Jian Min;Shen, Fu Guo;Bista, Krishna Bahadur;Zhao, Zhong Nan;Yang, Jianhua
    • Journal of Korean Neurosurgical Society
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    • v.56 no.5
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    • pp.375-382
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    • 2014
  • Objective : To assess the effect of bone marrow mononuclear cells (BMMNCs) transplantation in the expression of nuclear factor-${\kappa}B$ (NF-${\kappa}B$) in spinal cord injury (SCI) in rats. Methods : BMMNCs were isolated from tibia and femur by a density gradient centrifugation. After establishment of acute transection SCI, rats were divided into experiment (BMMNCs), experiment control (0.1 M PBS infused) and sham surgery groups (laminectomy without any SCI). Locomotor function was assessed weekly for 5 weeks post-injury using BBB locomotor score and urinary bladder function daily for 4 weeks post-injury. Activity of NF-${\kappa}B$ in spinal cord was assessed by immunohistochemistry and reverse transcriptase polymerase chain reaction. Results : At each time point post-injury, sham surgery group had significantly higher Basso, Beattie, Bresnahan locomotor and urinary bladder function scores than experiment and experiment control group (p<0.05). At subsequent time interval there were gradual improvement in both experiment and experiment control group, but experiment group had higher score in comparison to experiment control group (p<0.05). Comparisons were also made for expression of activated NF-${\kappa}B$ positive cells and level of NF-${\kappa}B$ messenger RNA in spinal cord at various time points between the groups. Activated NF-${\kappa}B$ immunoreactivity and level of NF-${\kappa}B$ mRNA expression were significantly higher in control group in comparison to experiment and sham surgery group (p<0.05). Conclusion : BMMNCs transplantation attenuates the expression of NF-${\kappa}B$ in injured spinal cord tissue and thus helps in recovery of neurological function in rat models with SCI.