• Molecules and Cells
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• 제20권1호
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• pp.105-111
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• 2005

Mannasantin B, a dilignan structurally related to manssantin A, is an inhibitor of NF-${\kappa}B$ transactivation. In the present study, we found that it inhibited PMA-induced expression of IL-$1{\beta}$, IL-$1{\beta}$ mRNA, and IL-$1{\beta}$ promoter activity in U937 cells with $IC_{50}$ values of about 50 nM. It also inhibited NF-IL6- and NF-${\kappa}B$-induced activation of IL-$1{\beta}$, with $IC_{50}$ values of 78 nM and $1.6{\mu}M$, respectively, revealing a potent inhibitory effect on NF-IL6. Electrophoretic mobility shift assays showed that manassantin B had an inhibitory effect on DNA binding by NF-IL6, but not by NF-${\kappa}B$. Further analysis revealed that transactivation by NF-IL6 was also inhibited. Our results indicate that manassantin B suppresses expression of IL-$1{\beta}$ in promonocytic cells by inhibiting not only NF-${\kappa}B$ but also NF-IL6 activity. Furthermore, our observations suggest that manassantin B may be clinically useful as a potent inhibitor of NF-IL6 activity.

• 대한의생명과학회지
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• 제22권2호
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• pp.60-64
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• 2016

In the pathogenesis of inflammatory diseases such as allergies, S100A8 acts as an important molecule and T lymphocytes are essential cytokine-releasing cells. In this study, we investigated the effect of S100A8 on release of cytokines, specifically MCP-1, IL-6, and IL-8 in T cells, and its associated signaling mechanism. S100A8 increased secretion of MCP-1, IL-6, and IL-8 in a time- and dose-dependent manner. Elevated secretion of MCP-1, IL-6, and IL-8 due to S100A8 was inhibited by the TLR4 inhibitor TLR4i, the PI3K inhibitor LY294002, the $PKC{\delta}$ inhibitor rottlerin, the ERK inhibitor PD98059, the p38 MAPK inhibitor SB202190, the JNK inhibitor SP600125, and the NF-${\kappa}B$ inhibitor BAY-11-7085. S100A8 induced phosphorylation of ERK, p38 MAPK, and JNK in a time-dependent manner, and activation was suppressed by TLR4i, LY294002, and rottlerin. S100A8 induced NF-${\kappa}B$ activation by $I{\kappa}-B{\alpha}$ degradation, and NF-${\kappa}B$ activity was suppressed by PD98059, SB202190, and SP600125. These results indicate that S100A8 induces cytokine release via TLR4. Study of PI3K, $PKC{\delta}$, MAPKs, and NF-${\kappa}B$ will contribute to elucidation of the S100A8-invovled mechanism.

• Molecules and Cells
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• 제41권12호
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• pp.1008-1015
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• 2018

$I{\kappa}B$, a cytoplasmic inhibitor of nuclear factor-${\kappa}B$ ($NF-{\kappa}B$), is reportedly degraded via the proteasome. However, we recently found that long-term incubation with proteasome inhibitors (PIs) such as PS-341 or MG132 induces $I{\kappa}B{\alpha}$ degradation via an alternative pathway, lysosome, which results in $NF-{\kappa}B$ activation and confers resistance to PI-induced lung cancer cell death. To enhance the anti-cancer efficacy of PIs, elucidation of the regulatory mechanism of PI-induced $I{\kappa}B{\alpha}$ degradation is necessary. Here, we demonstrated that PI up-regulates nuclear factor (erythroid-derived 2)-like 2 (Nrf2) via both de novo protein synthesis and Kelch-like ECH-associated protein 1 (KEAP1) degradation, which is responsible for $I{\kappa}B{\alpha}$ degradation via macroautophagy activation. PIs increased the protein level of light chain 3B (LC3B, macroautophagy marker), but not lysosome-associated membrane protein 2a (Lamp2a, the receptor for chaperone-mediated autophagy) in NCI-H157 and A549 lung cancer cells. Pretreatment with macroautophagy inhibitor or knock-down of LC3B blocked PI-induced $I{\kappa}B{\alpha}$ degradation. PIs up-regulated Nrf2 by increasing its transcription and mediating degradation of KEAP1 (cytoplasmic inhibitor of Nrf2). Overexpression of dominant-negative Nrf2, which lacks an N-terminal transactivating domain, or knock-down of Nrf2 suppressed PI-induced LC3B protein expression and subsequent $I{\kappa}B{\alpha}$ degradation. Thus, blocking of the Nrf2 pathway enhanced PI-induced cell death. These findings suggest that Nrf2-driven induction of LC3B plays an essential role in PI-induced activation of the $I{\kappa}B$/$NF-{\kappa}B$ pathway, which attenuates the anti-tumor efficacy of PIs.

• 생약학회지
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• 제35권1호통권136호
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• pp.92-97
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• 2004

Effect of AGI $({\alpha}-Glucosidase\;Inhibitor)-1120$, pine (Pinus densiflora) bark extract and Chaga mushroom (Inonotus obliquus) - and Chaga mushroom mycelium extracts on cellular $NF-{\kappa}B$ activation in malignant human keratinocytes (SCC-13) were evaluated to elucidate the possible correlation of $NF-{\kappa}B$ with antioxidant activity. The antioxidant activities of these natural products were examined in three different evaluation methods, i.e., lipid peroxidation value (POV) evaluation test, and 1,1diphenyl-2-picrylhydrazyl radical (DPPH) and nitric oxide (NO) scavenging test. In a cell-based $NF-{\kappa}B$ monitoring assay systern, all samples revealed the downregulatory profiles on the cellular $NF-{\kappa}B$ activity. AGI -1120 (1, 2 mg) and Chaga mushroom extract (0.05, 0.1 mg) downregulated the $NF-{\kappa}B$ activity in a dose-dependent manner. Chaga mushroom mycelium extract (5 mg) significantly inhibited the $NF-{\kappa}B$ activity (p<0.05). Although AGI-1120 and Chaga mushroom mycelium extract exhibited no antioxidant activities evaluated in pay, Chaga mushroom extract showed antioxidant in a dose-dependent manner at concentrations of $0.05{\sim}1$ mg. While AGI-1120 and Chaga mushroom extract possessed a relatively potential DPPH radical scavenging activity, the NO scavenging activity of Chaga mushroom extract $(SC_{50}:47\;{mu}g)$ was higher than the known antioxidant, vitamin C $(SC_{50}:77\;{mu}g)$. These results suggest that AGI-1120 and Chaga mushroom- and Chaga mushroom mycelium extracts may serve as an useful radical scavenging antioxidant agents with $NF-{\kappa}B$ inhibitory effect in human skin.

• BMB Reports
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• 제50권11호
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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.

• Journal of Korean Biological Nursing Science
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• 제14권2호
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• pp.129-138
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• 2012

Purpose: Cachexia is a complex metabolic syndrome associated with wasting of skeletal muscle which contributes to nearly one-third of all cancer deaths. Cachexia lowers the frequency of response to chemotherapy and radiation and ultimately can impact survival as well as quality of life during treatment. NF-kappa B is one of the most important molecular mediators of cachexia. In this study, therefore, possible candidates for inhibitors of NF-kappa B were searched. Methods: Amino acids that regulate cellular redox potential by adjusting the level of NAD/NADH ratio, such as aspartate, pyruvate, and isocitrate were selected. Results: Pyruvate effectively inhibited luciferase activity in TNF-stimulated 293T cells transfect with an NF-kB dependent luciferase reporter vector. Pyruvate also showed protective effect on muscle atrophy of differentiated C2C12 myocyte induced by TNF/IFN. Conclusion: We might be able to develop the nutritional management strategy for cancer cachexia patients with pyruvate supplementation.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제33권6호
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• pp.636-642
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• 2007

Background: CpG DNA plays an important role in immune cell function. This study examined whether the temporal control of toll-like receptor (TLR)9 by CpG DNA can regulate the expression of matrix metalloproteinase-9(MMP-9). Methods and materials: Macrophages were cultured in the presence of 10% FBS. For the various MMP genes analysis, RT-PCR and real-time PCR were performed. In addition, zymography assay performed for the MMP activity. The phosphorylation assay did for the ERK1/2 and NF${\kappa}B$ activation, and luciferase promoter assay was for the NF${\kappa}B$ activity. Results: CpG DNA induced the mRNA expression of MMP-2, MMP-9, and MMP-13, but not of MMP-7, MMP-8, and MMP-12, in a time-dependent manner. Especially, the mRNA expression of MMP-9 was strongly induced by CpG DNA using real-time RT-PCR. The TLR9 inhibitor, chloroquine, suppressed CpG DNA-induced MMP-9 expression and its activity. Moreover, CpG DNA induced the phosphorylation of ERK and the inhibition of ERK by U0126 suppressed CpG DNA-induced MMP-9 expression and its activity. CpG DNA stimulated $I{\kappa}B-{\alpha}$ degradation and luciferase activity. In addition, pretreatment of SN-50, the inhibitor of NF${\kappa}B$, strongly blocked the CpG DNA-induced MMP-9 expression and activity. Conclusion: These observations suggest that CpG DNA may play important roles in the activation of macrophages by regulating the production of MMP-9 via the sequential TLR9-ERK-NF${\kappa}B$ signaling pathway.

• The Korean Journal of Physiology and Pharmacology
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• 제14권6호
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• pp.353-358
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• 2010

This study demonstrates the ability of magnolol, a hydroxylated biphenyl compound isolated from Magnolia officinalis, to inhibit LPS-induced expression of iNOS gene and activation of NF-${\kappa}B$/Rel in RAW 264.7 cells. Immunohisto-chemical staining of iNOS and Western blot analysis showed magnolol to inhibit iNOS gene expression. Reporter gene assay and electrophoretic mobility shift assay showed that magnolol inhibited NF-${\kappa}B$/Rel transcriptional activation and DNA binding, respectively. Since p38 is important in the regulation of iNOS gene expression, we investigated the possibility that magnolol to target p38 for its anti-inflammatory effects. A molecular modeling study proposed a binding position for magnolol that targets the ATP binding site of p38 kinase (3GC7). Direct interaction of magnolol and p38 was further confirmed by pull down assay using magnolol conjugated to Sepharose 4B beads. The specific p38 inhibitor SB203580 abrogated the LPS-induced NF-${\kappa}B$/Rel activation, whereas the selective MEK-1 inhibitor PD98059 did not affect the NF-${\kappa}B$/Rel. Collectively, the results of the series of experiments indicate that magnolol inhibits iNOS gene expression by blocking NF-${\kappa}B$/Rel and p38 kinase signaling.

• Fisheries and Aquatic Sciences
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• 제19권9호
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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.

• Journal of Acupuncture Research
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• 제23권2호
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• pp.47-59
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• 2006

We previously found that cobrotoxin inhibited $NF-{\kappa}B$ activity by reacting with signal molecules of $NF-{\kappa}B$ which is critical contributor in cancer cell growth by induction of apoptotic cell death. We here investigated whether cobrotoxin inhibits cell growth of human prostate cancer cells through induction of apoptotic cell death, which is related with the suppression of the $NF-{\kappa}B$ activity. Cobrotoxin $(0{\sim}8\;nM)$ inhibited prostate cancer cell growth through increased apoptosis in a dose dependent manner. Cobrotoxin inhibited DNA binding activity of $NF-{\kappa}B$, an anti-apoptotic transcriptional factor. Consistent with the induction of apoptosis and inhibition of $NF-{\kappa}B$, cobrotoxin increased the expression of pro-apoptotic proteins caspase 3. Cobrotoxin, a venom of Vipera lebetina turanica, is a group of basicpeptides composed of 233 amino acids with six disulfide bonds formed by twelve cysteins. NF-kB is activated by subsequent release of inhibitory IkB and translocation of p50. Since sulfhydryl group is present in kinase domain of p50 subunit of NF-kB, cobrotoxin could modify NF-kB activity by protein-protein interaction. And Cobrotoxin down regulated Akt signals. Salicylic acid as a reducing agent of Sulf-hydryl group and LY294002 as a Akt inhibitor abrogated cobrotoxin-induced cell growth and DNA binding activity of $NF-{\kappa}B$. These findings suggest that nano to pico molar range of cobrotoxin could inhibit prostate cancer cell growth, and the effect may be related with the induction of apoptotic cell death through Akt dependent inhibition of $NF-{\kappa}B$ signal.