• Journal of the Institute of Electronics Engineers of Korea TC
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• v.45 no.12
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• pp.20-25
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• 2008

Codebook-based opportunistic beamforming (COBF) technique provides a beam selection diversity to the conventional opportunistic beamforming. In this paper, we design the random matrix and codebook for the COBF technique based on a kappa-factor channel model. Applying the proposed design to the COBF, nearly optimal beams are generated. Therefore, the COBF shows an outstanding performance without regard to the channel correlation related to the kappa-factor.

• 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.

• Molecules and Cells
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• v.20 no.3
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• pp.364-370
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• 2005

We show that sulforaphane inhibits osteoclastogenesis in the presence of macrophage colony-stimulating factor (M-CSF) and receptor for activation of nuclear factor-${\kappa}B$ ligand (RANKL) in osteoclast (OC) precursors. Sulforaphane, an aliphatic isothiocyanate, is a known cancer chemo-preventative agent with anti-oxidative properties. Nuclear factor-${\kappa}B$ (NF-${\kappa}B$) is a critical transcription factor in RANKL-induced osteoclastogenesis, and electrophoretic mobility shift assays (EMSAs) and assay of NF-${\kappa}B$-mediated secreted alkaline phosphatase (SEAP) revealed that sulforaphane selectively inhibited NF-${\kappa}B$ activation induced by RANKL. Inhibition may involve interaction of sulforaphane with thiol groups, since it was prevented by reducing agents.

• BMB Reports
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• v.50 no.11
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• pp.584-589
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• 2017

Intercellular adhesion molecule-1 (ICAM-1), which is induced by tumor necrosis factor (TNF)-${\alpha}$, contributes to the entry of immune cells into the site of inflammation in the skin. Here, we show that protein tyrosine phosphatase non-receptor type 21 (PTPN21) negatively regulates ICAM-1 expression in human keratinocytes. PTPN21 expression was transiently induced after stimulation with TNF-${\alpha}$. When overexpressed, PTPN21 inhibited the expression of ICAM-1 in HaCaT cells but PTPN21 C1108S, a phosphatase activity-inactive mutant, failed to inhibit ICAM-1 expression. Nuclear factor-${\kappa}B$ (NF-${\kappa}B$), a key transcription factor of ICAM-1 gene expression, was inhibited by PTPN21, but not by PTPN21 C1108S. PTPN21 directly dephosphorylated phospho-inhibitor of ${\kappa}B$ ($I{\kappa}B$)-kinase ${\beta}$ ($IKK{\beta}$) at Ser177/181. This dephosphorylation led to the stabilization of $I{\kappa}B{\alpha}$ and inhibition of NF-${\kappa}B$ activity. Taken together, our results suggest that PTPN21 could be a valuable molecular target for regulation of inflammation in the skin by dephosphorylating p-$IKK{\beta}$ and inhibiting NF-${\kappa}B$ signaling.

• Biomolecules & Therapeutics
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• v.17 no.3
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• pp.219-240
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• 2009

Since NF-${\kappa}B$ has been identified as a transcription factor associated with immune cell activation, groups of researchers have dedicated to reveal detailed mechanisms of nuclear factor of ${\kappa}B$ (NF-${\kappa}B$) in inflammatory signaling for decades. The various molecular components of NF-${\kappa}B$ transcription factor pathway have been being evaluated as important therapeutic targets due to their roles in diverse human diseases including inflammation, cystic fibrosis, sepsis, rheumatoid arthritis, cancer, atherosclerosis, ischemic injury, myocardial infarction, osteoporosis, transplantation rejection, and neurodegeneration. With regards to new drugs directly or indirectly modulating the NF-${\kappa}B$ pathway, FDA recently approved a proteasome inhibitor bortezomib for the treatment of multiple myeloma. Many pharmaceutical companies have been trying to develop new drugs to inhibit various kinases in the NF-${\kappa}B$ signaling pathway for many therapeutic applications. However, a gene knock-out study for $IKK{\beta}$ in the NF-${\kappa}B$ pathway has given rise to controversies associated with efficacy as therapeutics. Mice lacking hepatocyte $IKK{\beta}$ accelerated cancer instead of preventing progress of cancer. However, it is clear that pharmacological inhibition of $IKK{\beta}$ appears to be beneficial to reduce HCC. This article will update issues of the NF-${\kappa}B$ pathway and inhibitors regulating this pathway.

• Tuberculosis and Respiratory Diseases
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• v.54 no.5
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• pp.495-509
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• 2003

Background : Neutrophil-mediated inflammation is usually self-limiting, because neutrophils have a remarkably short life span. Prolonged neutrophil survival, which is caused by decreased spontaneous apoptosis, leads to persistent inflammation in sepsis. Because many inflammatory cytokines, which generate signals that delay apoptosis, are regulated by nuclear factor-${\kappa}B$ transcription factor, we hypothesized that nuclear factor-${\kappa}B$ might be related to the reduced neutrophil apoptosis observed in sepsis. Methods : Neutrophils of healthy volunteers and sepsis patients were freshly isolated from venous blood. Neutrophil apoptosis was assayed with two approaches : by counting apoptotic cells under a microscope and by flow cytometry using Annexin V. The activity of nuclear factor-${\kappa}B$ was assessed by immunofluorescent staining or electrophoretic mobility shift assay. Expression of X-linked inhibitor of apoptosis was measured by western blot assay. Results : We confirmed reduced spontaneous neutrophil apoptosis in patients with sepsis. The number of apoptotic neutrophils in patients with sepsis increased to the level of that in healthy controls after cycloheximide treatment, suggesting that decreased spontaneous neutrophil apoptosis is dependent on de novo protein synthesis. In patients with sepsis, basal neutrophil nuclear factor-${\kappa}B$ was activated compared to the level in healthy controls. Moreover, a blockade of nuclear factor-${\kappa}B$ activity reversed the decreased spontaneous neutrophil apoptosis in sepsis patients. Meanwhile, X-linked inhibition of apoptosis expression, which is regulated by nuclear factor-${\kappa}B$, decreased 24 hours after incubation in healthy persons, but persisted for 24 hours in patients with sepsis. Conclusion : These observations suggest that the reduced spontaneous neutrophil apoptosis observed in patients with sepsis may be related to the induction of survival protein by nuclear factor-${\kappa}B$.

• Journal of agriculture & life science
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• v.50 no.2
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• pp.151-160
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• 2016

Inflammatory cytokines play a major role in osteoclastogenesis, leading to the bone resorption that is frequently associated with osteoporosis. Sulforaphane, isolated from the Broccoli(Brassica oleracea var. italia) florets, inhibits the production of inflamatory cytokine. In the present study, we determined inhibitory effect of sulforaphane on Receptor activator of nuclear factor κB ligand(RANKL)-induced osteoclast formation. Sulforaphane inhibited the expression of osteoclast marker genes, such as tartrate-resistant acid phosphatase(TRAP), cathepsin K, matrix metalloproteinase 9(MMP-9), and calcitonin receptor in RANKL-induced RAW 264.7 macrophage. Also, sluforaphane inhibited the expression of osteoclast protein, such as TRAP, MMP-9, tumor necrosis factor receptor-associated factor 6(TRAF6) and transcription factor nuclease factor of activated T cells(NFAT)c1. Sulforaphane inhibited RANKL-induced activiation of nuclear factor kappaB(NF-kappaB) by suppression RANKL-mediated NF-kappaB transcriptional acitivation. We are confirmed that sulforaphane inhibits not only transcriptional activity of NF-kappaB but also expressions of the osteoclastogenesis factors(TRAP, cathepsin K, MMP-9, calcitonin, TRAF6) and trranscription factor NFATc1.

• BMB Reports
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• v.48 no.10
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• pp.559-564
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• 2015

We investigated the effects of mangiferin on the expression and activity of metalloproteinase (MMP)-9 and the invasion of tumor necrosis factor (TNF)-$\alpha$-stimulated human LNCaP prostate carcinoma cells. Reverse-transcription polymerase chain reaction (RT-PCR) and western blot analysis showed that mangiferin significantly reversed TNF-$\alpha$-induced mRNA and protein expression of MMP-9 expression. Zymography data confirmed that stimulation of cells with TNF-$\alpha$ significantly increased MMP-9 activity. However, mangiferin substantially reduced the TNF-$\alpha$-induced activity of MMP-9. Additionally, a matrigel invasion assay showed that mangiferin significantly reduced TNF-$\alpha$-induced invasion of LNCaP cells. Compared to untreated controls, TNF-$\alpha$-stimulated LNCaP cells showed a significant increase in nuclear factor-${\kappa}B$ (NF-${\kappa}B$) luciferase activity. However, mangiferin treatment markedly decreased TNF-$\alpha$-induced NF-${\kappa}B$ luciferase activity. Furthermore, mangiferin suppressed nuclear translocation of the NF-${\kappa}B$ subunits p65 and p50. Collectively, our results indicate that mangiferin is a potential anti-invasive agent that acts by suppressing NF-${\kappa}B$-mediated MMP-9 expression.

• Molecules and Cells
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• v.40 no.10
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• pp.706-713
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• 2017

Osteoclasts are bone-resorbing cells that are derived from hematopoietic precursor cells and require macrophage-colony stimulating factor and receptor activator of nuclear factor-${\kappa}B$ ligand (RANKL) for their survival, proliferation, differentiation, and activation. The binding of RANKL to its receptor RANK triggers osteoclast precursors to differentiate into osteoclasts. This process depends on RANKL-RANK signaling, which is temporally regulated by various adaptor proteins and kinases. Here we summarize the current understanding of the mechanisms that regulate RANK signaling during osteoclastogenesis. In the early stage, RANK signaling is mediated by recruiting adaptor molecules such as tumor necrosis factor receptorassociated factor 6 (TRAF6), which leads to the activation of mitogen-activated protein kinases (MAPKs), and the transcription factors nuclear factor-${\kappa}B$ (NF-${\kappa}B$) and activator protein-1 (AP-1). Activated NF-${\kappa}B$ induces the nuclear factor of activated T-cells cytoplasmic 1 (NFATc1), which is the key osteoclastogenesis regulator. In the intermediate stage of signaling, the co-stimulatory signal induces $Ca^{2+}$ oscillation via activated phospholipase $C{\gamma}2$ ($PLC{\gamma}2$) together with c-Fos/AP-1, wherein $Ca^{2+}$ signaling facilitates the robust production of NFATc1. In the late stage of osteoclastogenesis, NFATc1 translocates into the nucleus where it induces numerous osteoclast-specific target genes that are responsible for cell fusion and function.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.21 no.3
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• pp.82-93
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• 2008

Objective: Previously, the methanol extracts of the semen of Xanthium strumsrium could involved anti-inflammatory effects in lipopolysaccharide (LPS)-stimulated Raw 264,7 cells, We evaluated the anti-allergic effects of X. strumarium on rat basophilic leukemia (RBL-2H3) cells, Methodes : To investigate the effect of X. strumarium on the phorbol 12-myristate 13-acetate (PMA) and calcium ionophore A23187-induced RBL-2H3 cells. The effects of X. strumarium on the degranulation and the pro-inflammatory cytokines secretion and expression from RBL-2H3 cells were evaluated with $\beta$-hexosaminidase assay, ELISA, and RT-PCR analysis, In addition, we examined the effects of X. strumarium on nuclear factor (NF)-${\kappa}B$ activation and $I{\kappa}B-\alpha$ degradation using Western blot analysis. Results : X. strumarium inhibited degranulation and secretions and expressions of pro-inflammatory cytokines, such as tumor necrosis factor-alpha ($TNF-\alpha$), interleukin (IL)-4 and cyclooxygenase (COX)-2, on stimulated RBL-2H3 cells, however, X. strumarium not affect cell viability. In stimulated RBL-2H3 cells, the protein expression level of nuclear factor-kappa B (NF-${\kappa}B$) was decreased in the nucleus by X. strumarium. In addition, X. strumarium suppressed the degradation of inhibitory protein $I{\kappa}B-{\alpha}$ protein in RBL-2H3 cells. Conclusion : These results suggest that X. strumarium inhibits the degranulation and secretion of pro-inflammatory cytokines through blockade of NF-${\kappa}B$ activation and I $I{\kappa}B-{\alpha}$ degradation.