• Journal of Microbiology and Biotechnology
• /
• v.29 no.8
• /
• pp.1316-1323
• /
• 2019

Middle East respiratory syndrome coronavirus (MERS-CoV) is a newly emerging coronavirus which is zoonotic from bats and camels. Its infection in humans can be fatal especially in patients with preexisting conditions due to smoking and chronic obstructive pulmonary disease (COPD). Among the 25 proteins encoded by MERS-CoV, 5 accessory proteins seem to be involved in viral evasion of the host immune responses. Here we report that ORF4a, ORF4b, and ORF8b proteins, alone or in combination, effectively antagonize nuclear factor kappa B ($NF-{\kappa}B$) activation. Interestingly, the inhibition of $NF-{\kappa}B$ by MERS-CoV accessory proteins was mostly at the level of pattern recognition receptors: melanoma differentiation-associated gene 5 (MDA5). ORF4a and ORF4b additively inhibit MDA5-mediated activation of $NF-{\kappa}B$ while that of retinoic acid-inducible gene 1 (RIG-I) is largely not perturbed. Of note, ORF8b was found to be a novel antagonist of MDA5-mediated $NF-{\kappa}B$ activation. In addition, ORF8b also strongly inhibits Tank-binding kinase 1 (TBK1)-mediated induction of $NF-{\kappa}B$ signaling. Taken together, MERS-CoV accessory proteins are involved in viral escape of $NF-{\kappa}B$-mediated antiviral immune responses.

• Molecules and Cells
• /
• v.25 no.2
• /
• pp.253-257
• /
• 2008

Acrolein is a highly electrophilic ${\alpha},{\beta}$-unsaturated aldehyde present in a number of environmental sources, especially cigarette smoke. It reacts strongly with the thiol groups of cysteine residues by Michael addition and has been reported to inhibit nuclear $factor-{\kappa}B$ ($NF-{\kappa}B$) activation by lipopolysaccharide (LPS). The mechanism by which it inhibits $NF-{\kappa}B$ is not clear. Toll-like receptors (TLRs) play a key role in sensing microbial components and inducing innate immune responses, and LPS-induced dimerization of TLR4 is required for activation of downstream signaling pathways. Thus, dimerization of TLR4 may be one of the first events involved in activating TLR4-mediated signaling pathways. Stimulation of TLR4 by LPS activates both myeloid differential factor 88 (MyD88)- and TIR domain-containing adapter inducing $IFN{\beta}$ (TRIF)-dependent signaling pathways leading to activation of $NF-{\kappa}B$ and IFN-regulatory factor 3 (IRF3). Acrolein inhibited $NF-{\kappa}B$ and IRF3 activation by LPS, but it did not inhibit $NF-{\kappa}B$ or IRF3 activation by MyD88, inhibitor ${\kappa}B$ kinase $(IKK){\beta}$, TRIF, or TNF-receptor-associated factor family member-associated $NF-{\kappa}B$ activator (TANK)-binding kinase 1 (TBK1). Acrolein inhibited LPS-induced dimerization of TLR4, which resulted in the down-regulation of $NF-{\kappa}B$ and IRF3 activation. These results suggest that activation of TLRs and subsequent immune/inflammatory responses induced by endogenous molecules or chronic infection can be modulated by certain chemicals with a structural motif that enables Michael addition.

• Korean Journal of Pharmacognosy
• /
• v.35 no.3 s.138
• /
• pp.244-249
• /
• 2004

The effects of hesperetin and naringenin on $NF-{\kappa}B$ activation were investigated in normal rat kidney cells transformed by temperature sensitive Rous Sarcoma Virus (tsNRK). The flavonoids, naringenin and hesperetin, significantly reduced v-Src-induced $NF-{\kappa}B$ activation as well as phosphorylation of Akt and GSK-3 in tsNRK cells, whereas these compounds did not effect on platelet-derived growth factor (PDGF)-induced $NF-{\kappa}B$ activation in $NIH3T3{\gamma}l$ cells. In addition, the DNA binding activity of SP-I was also reduced but that of AP-1 was not affected by the compounds. Our study suggests that Src-induced $NF-{\kappa}B$ activation could occur via Akt-GSK-3 pathway without $IkB{\alpha}$ degradation and that naringenin and hesperetin could be used in the treatment of cancer through the inhibition of $NF-{\kappa}B$ activation.

• Proceedings of the PSK Conference
• /
• 2003.04a
• /
• pp.120.1-120.1
• /
• 2003

Nuclear factor-${\kappa}{B}$ (NF-${\kappa}{B}$) belongs to a group of homodimers and heterodimers of Rel/NF-${\kappa}{B}$ proteins that bind to DNA target sites, where they directly regulate gene transcription. The activation of NF-${\kappa}{B}$ has been shown to mediate inflammation and suppress apoptosis. Activated NF-${\kappa}{B}$ has been found n various inflammatory diseases such as rheumatoid arthritis, Atherosclerosis, asthma, nflammatory bowel disease, and Helicobacter pylori-associated gastritis and associated with cancer, cachexia, diabetes, euthyroid sick syndrome, and AIDS. (omitted)

• Journal of Food Hygiene and Safety
• /
• v.21 no.3
• /
• pp.181-188
• /
• 2006

Tumor necrosis factor-alpha $(TNF-{\alpha})$ plays a variety of biological functions such as apoptosis, inflammation and immunity. PTEN also has various cellular function including cell growth, proliferation, migration and differentiation. Thus, possible relationships between two molecules are suggested. $(TNF-{\alpha})$has been known to downregulate PTEN via nuclear factor-kappa $B(NF-{\kappa}B)$ pathway in the human colon cell line, HT-29. However, here we show the opposite finding that $(TNF-{\alpha})$ upregulates PTEN via activation of $NF-{\kappa}B$ in HL-60 cells. $TNF-{\alpha}$ increased PTEN expression at HL-60 cells in a time- and dose-dependent manner, but the response was abolished by disruption of $NF-{\kappa}B$ with p65 anisense oligonucleotide or pyrrolidine dithiocarbamate (PDTC). We found that $TNF-{\alpha}$ activated the $NF-{\kappa}B$ pathways, evidenced by the translocation of p65 to the nucleus in $TNF-{\alpha}-treated$ cells. We conclude that $TNF-{\alpha}$ induces upregulation of PTEN expression through $NF-{\kappa}B$ activation in HL-60 cells.

• Natural Product Sciences
• /
• v.20 no.4
• /
• pp.227-231
• /
• 2014

Cimicifuga heracleifolia extract (CHE) was investigated for its effects on the release of nitric oxide (NO) and at the level of inducible nitric oxide synthase (iNOS) gene expression in mouse macrophages. We found that C. heracleifolia elicited a dose-dependent increase in NO production and the level of iNOS mRNA. Since, iNOS transcription has been shown to be under the control of the transcription factor $NF-{\kappa}B$, the effects of CHE on $NF-{\kappa}B$ activation were examined. Transient expression assays with $NF-{\kappa}B$ binding sites linked to the luciferase gene revealed that the increased level of iNOS mRNA, induced by CHE, was mediated by the $NF-{\kappa}B$ transcription factor complex. By using DNA fragments containing the $NF-{\kappa}B$ binding sequence, CHE was shown to activate the protein/DNA binding of $NF-{\kappa}B$ to its cognate site, as measured by electrophoretic mobility shift assay. These results demonstrate that C. heracleifolia stimulates NO production and is able to up-regulate iNOS expression through $NF-{\kappa}B$ transactivation.

• Journal of Veterinary Clinics
• /
• v.29 no.5
• /
• pp.361-367
• /
• 2012

Diabetes-related complications in human and veterinary medicine have been shown to be associated with hyperglycemia-induced inflammation. It has been recently suggested that the onset of insulin resistance may be caused by over-production of inflammatory cytokines such as tumor necrosis factor (TNF)-${\alpha}$ from immune cells. Conjugated linoleic acid (CLA) regulates inflammatory response through modulation of TNF-${\alpha}$ expression. The objective of this study was to examine the effect of CLA on nuclear factor kappaB (NF-${\kappa}B$) p65 binding activity, inhibitory kappaB ($I{\kappa}B$)-${\alpha}$ expression, and TNF-${\alpha}$ production from high glucose-treated RAW 264.7 cells. CLA was added to RAW cells that had been previously cultured with low or high concentration of glucose. The levels of TNF-${\alpha}$ protein in the culture supernatant of RAW cells exposed to high concentrations of glucose were higher than those of cells exposed to low concentrations of glucose. The treatment with the high concentration of glucose in RAW cells increased levels of NF-${\kappa}B$ p65 binding activity and the decreased $I{\kappa}B-{\alpha}$ expression when compared with those of low glucose. The treatments in combination with CLA and glucose (low and high) glucose in RAW cells increased TNF-${\alpha}$ production when compared with that glucose alone. These treatments with CLA increased TNF-${\alpha}$ production in high glucose-treated RAW cells than those with low glucose. These treatments of CLA also showed higher NF-${\kappa}B$ p65 binding activity and lower $I{\kappa}B-{\alpha}$ expression in high glucose than those in low glucose condition. This suggests that CLA can increase NF-${\kappa}B$ p65 binding activity and TNF-${\alpha}$ production from high glucose-treated RAW 264.7 cells and is likely to promote hyperglycemia-induced inflammation.

• Journal of Acupuncture Research
• /
• v.21 no.6
• /
• pp.19-36
• /
• 2004

Objective : The purpose of this study was to investigate the effect of Bee Venom and Melittin Solution on the lipopolysaccharide(LPS) and sodium nitroprusside(SNP)-induced expression of prostaglandin $E_2(PGE_2)$, cyclooxygenase-2(COX-2), nuclear factor kappa B($NF-{\kappa}B$) and nuclear factor kappa B($NF-{\kappa}B$) dependent luciferase activity in RAW 264.7 cells, a murine macrophage cell line. Methods : The expression of PGE2 was determined by determination of $PEG_2$, COX-2 was by western blotting with corresponding antibodies, $NF-{\kappa}B$ was by gel mobility shift assay method and $NF-{\kappa}B$ dependent luciferase activity was investigated by luciferase assay in RAW 264.7 cells. Results : 1. LPS and SNP-induced expression of $PEG_2$ was significant after 24hour. 2. The 0.5, 1 and $5{\mu}g/mL$ of bee venom and the 5 and $10{\mu}g/mL$ of melittin solution inhibited significantly LPS-induced expression of $PEG_2$ and, the $5{\mu}g/mL$ of bee venom and the 5 and $10{\mu}g/mL$ of melittin solution inhibited significantly SNP-induced expression of $PEG_2$ compared with control, respectively. The 0.5 and $1{\mu}g/mL$ of bee venom could not significantly inhibit SNP-induced expression of $PEG_2$ compared with control. 3. The $5{\mu}g/mL$ of bee venom and the 5 and $10{\mu}g/mL$ of melittin solution inhibited significantly LPS and SNP-induced expression of COX-2 compared with control, respectively. The 0.5 and $1{\mu}g/mL$ of bee venom inclined to decrease LPS and SNP-induced expression of COX-2 compared with control. 4. The 0.5, 1 and $5{\mu}g/mL$ of bee venom and the 5 and $10{\mu}g/mL$ of melittin solution inhibited significantly LPS and SNP-induced expression of $NF-{\kappa}B$ compared with control, respectively. 5. The 0.5, 1 and $5{\mu}g/mL$ of bee venom and the 5 and $10{\mu}g/mL$ of melittin solution inhibited significantly LPS-induced expression of $NF-{\kappa}B$ dependent luciferase activity and the 1 and $5{\mu}g/mL$ of bee venom and the 5 and $10{\mu}g/mL$ of melittin solution inhibited significantly SNP-induced expression of $NF-{\kappa}B$ dependent luciferase activity compared with control, respectively. The $NF-{\kappa}B$ inhibitor also inhibited significantly LPS and SNP-induced expression of $NF-{\kappa}B$ dependent luciferase activity compared with control. 6. The 0.5, 1 and $5{\mu}g/mL$ of bee venom and the 5 and $10{\mu}g/mL$ of melittin solution inhibited significantly LPS + IFN-${\gamma}$, TNF-${\alpha}$ and LPS + TNF-${\alpha}$-induced expression of $NF-{\kappa}B$ dependent luciferase activity compared with control, respectively. The $NF-{\kappa}B$ inhibitor also inhibited significantly LPS and SNP-induced expression of $NF-{\kappa}B$ dependent luciferase activity compared with control. Conclusions : These results suggest the inhibitory action of bee venom and melittin solution on the inflammatory mediators such as $PEG_2$, COX-2 and $NF-{\kappa}B$.

• Tuberculosis and Respiratory Diseases
• /
• v.51 no.2
• /
• pp.122-134
• /
• 2001

Background : Some chemotherapeutic drugs induce NF-${\kappa}B$ activation by degrading the $I{\kappa}B{\alpha}$ protein in cancer cells which contributes to anticancer drug resistance. We hypothesized that inhibiting $I{\kappa}B{\alpha}$ degradation would block NF-${\kappa}B$ activation and result in increased tumor cell mortality in response to chemotherapy. Methods : The "superrepressor" form of the NF-${\kappa}B$ inhibitor was transferred by an adenoviral vector (Ad-$I{\kappa}B{\alpha}$-SR) to the human lung cancer cell lines (NCI H157 and NCI H460). With a MIT assay, the level of sensitization to cisplatin and paclitaxel were measured. To confirm the mechanism, an EMSA and Annexin V assay were performed. Results : EMSA showed that $I{\kappa}B{\alpha}$-SR effectively blocked the NF-${\kappa}B$ activation induced by cisplatin. Transduction with Ad-$I{\kappa}B{\alpha}$-SR resulted in an increased sensitivity of the lung cancer cell lines to cisplatin and paclitaxel by a factor of 2~3 in terms of $IC_{50}$. Annexin-V analysis suggests that this increment in chemosensitivity to cisplatin probably occurs through the induction of apoptosis. Conclusion : The blockade of chemotherapeutics induced NF-${\kappa}B$ activation by inducing Ad-$I{\kappa}B{\alpha}$-SR, increased apoptosis and increasing the chemosensitivity of the lung cancer cell lines tested, subsequently. Gene transfer of $I{\kappa}B{\alpha}$-SR appears to be a new therapeutic strategy of chemosensitization in lung cancer.

• Journal of Acupuncture Research
• /
• v.22 no.3
• /
• pp.155-167
• /
• 2005

Objectives : The purpose of this study was to investigate the anti-inflammatory effect of Cobrotoxin on binding affinity of cobrotoxin with P50, $IKK{\alpa}$ and $IKK{\beta}$, activities of NF-${\kappa}B$, Cell viability of astrocyte, expressions of protein molecules of NF-${\kappa}B$ such as P50, P-$1{kappa}B$, $1{\kappa}B$ and iflammation related genes such as Cox-2, iNOS, cPLA2 in the SNP or LPS induced Inflammatory pathway of Rats' astrocytes. Methods : In this study, The expression of cytosolic phospholipase A2, Nitric oxcide, Cyclooxygenase-2 and inducible nitrogen oxide synthase was determined by western blotting with corresponding antibodies, and the generation of NF-${\kappa}B$ was assayed by EMSA method in astrocytes of rats. The Cell viability of astrocytes was determined by MTT assay, and Binding affinity of Cobrotoxin with P50, $IKK{\alpha}$ and $IKK{\beta}$ was assayed by Surface plasmon resonance analysis, and NF-${\kappa}B$ dependent luciferase activity was determined by luciferase analysis, and Uptake of cobrotoxin in astrocytes was identified by Confocal laser scanning microscope Results : 1. Compared with control, LPS-induced NF-${\kappa}B$ DNA binding activity was decreased significantly by 0.1, $0.5{\mu}g/m{\ell}$ of Cobrotoxin in Astrocyte. 2. Compared with control, LPS-induced NF-kB dependent luciferase expression was decreased significantly by 0.1, 0.5 and $1{\mu}g/m{\ell}$ of Cobrotoxin in Astrocyte. 3. Compared with control, SNP induced P50, $I{\kappa}B$ expressions in astrocyte were decreased significantly by 0.1, 0.5 and $1{\mu}g/m{\ell}$ of Cobrotoxin and P-$1{\kappa}B$ expression was decreased significantly by 0.5 and $1{\mu}g/m{\ell}$ of Cobrotoxin. 4. Compared with control, LPS induced P50, $1{\kappa}B$ expressions in astrocyte were decreased significantly by 0.5 and $1{\mu}g/m{\ell}$ of Cobrotoxin. 5. Compared with control, SNP induced Cox-2, iNOS, CPLA2 expressions in astrocyte were decreased significantly by $1{\mu}g/m{\ell}$ of Cobrotoxin. 6. Compared with control, LPS induced Cox-2, cPLA2 expressions in astrocyte were decreased significantly by 0.1, 0.5, $1{\mu}g/m{\ell}$ of Cobrotoxin and iNOS expression was decreased significantly by 0.5, $1{\mu}g/m{\ell}$ of Cobrotoxin. 7. Compared with $0.5{\mu}g/m{\ell}$ of Cobrotoxin, SNP-induced NF-${\kappa}B$ DNA bindins activity in astrocyte was increased significantly by Cobrotoxin $0.5{\mu}g/m{\ell}$ with DTT 1mM and Cobrotoxin $0.5{\mu}g/m{\ell}$ with DTT 5mM. 8. Compared with $0.5{\mu}g/m{\ell}$ of Cobrotoxin, LPS-induced NF-${\kappa}B$ DNA binding activity in astrocyte was increased significantly by Cobrotoxin $0.5{\mu}g/m{\ell}$ with DTT 1mM, Cobrotoxin $0.5{\mu}g/m{\ell}$ with DTT 5mM, Cobrotoxin $0.5{\mu}g/m{\ell}$with GSH 1mM and Cobrotoxin $0.5{\mu}g/m{\ell}$ with GSH 5mM 9. Compared with $0.1{\mu}g/m{\ell}$ of cobrotoxin, SNP induced P50 expressions in astrocyte were increased significantly by Cobrotoxin $0.5{\mu}g/m{\ell}$ with DTT 1mM, Cobrotoxin $0.5{\mu}g/m{\ell}$ with DTT 5mM Cobrotoxin $0.5{\mu}g/m{\ell}$ with GSH 1mM and Cobrotoxin $0.5{\mu}g/m{\ell}$ with GSH 5mM. 10. The uptake of the labeled cobrotoxin into the cells was shown under a confocal laser scanning microscope. cobrotoxin was uptaken into the membrane and nucleus of astrocytes. Conclusions : In summary, the present results demonstrate that cobrotoxin directly binds to sulfhydryl group of p50 and IKKS resulting In the reduction of translocation of p50 and IkB release, thereby inhibits activation of NF-${\kappa}B$, and suggest that pico to nanomolar range of cobrotoxin could inhibit the expression of genes in the NF-${\kappa}B$ signal pathway.