• International Journal of Oral Biology
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• v.42 no.4
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• pp.149-153
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• 2017

Cyclooxygenase-2 (COX-2)-mediated prostaglandin $E_2$ ($PGE_2$) plays a key role in development and progression of inflammatory responses and Porphyromonas gingivalis is a common endodontic pathogen. In this study, we investigated induction of COX-2 and $PGE_2$ by P. gingivalis in human dental pulp cells (HDPCs). P. gingivalis increased expression of COX-2, but not that of COX-1. Increased levels of $PGE_2$ were released from P. gingivalis-infected HDPCs and this $PGE_2$ increase was blocked by celecoxib, a selective COX-2 inhibitor. P. gingivalis activated all three types of mitogen-activated protein kinases (MAPKs). P. gingivalis-induced activation of nuclear $factor-{\kappa}B$ ($NF-{\kappa}B$) was demonstrated by the results of phosphorylation of $NF-{\kappa}B$ p65 and degradation of inhibitor of ${\kappa}B-{\alpha}$ ($I{\kappa}B-{\alpha}$). Pharmacological inhibition of each of the three types of MAPKs and $NF-{\kappa}B$ substantially attenuated P. gingivalis-induced $PGE_2$ production. These results suggest that P. gingivalis should promote endodontic inflammation by stimulating dental pulp cells to produce $PGE_2$.

• The Korean Journal of Physiology and Pharmacology
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• v.17 no.2
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• pp.133-137
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• 2013

Vascular cell adhesion molecule 1 (VCAM-1), intercellular adhesion molecule 1 (ICAM-1), P- and E-selectin play a pivotal role for initiation of atherosclerosis. Ginsenoside, a class of steroid glycosides, is abundant in Panax ginseng root, which has been used for prevention of illness in Korea. In this study, we investigated the mechanism(s) by which ginsenoside Rg2 may inhibit VCAM-1 and ICAM-1 expressions stimulated with lipopolysaccharide (LPS) in human umbilical vein endothelial cell (HUVEC). LPS increased VCAM-1 and ICAM-1 expression. Ginsenoside Rg2 prevented LPS-mediated increase of VCAM-1 and ICAM-1 expression. On the other hand, JSH, a nuclear factor kappa B (NF-${\kappa}B$) inhibitor, reduced both VCAM-1 and ICAM-1 expression stimulated with LPS. SB202190, inhibitor of p38 mitogen-activated protein kinase (p38 MAPK), and wortmannin, phosphatidylinositol 3-kinase (PI3-kinase) inhibitor, reduced LPS-mediated VCAM-1 but not ICAM-1 expression. PD98059, inhibitor of mitogen-activated protein kinase kinase/extracellular signal-regulated kinase (MEK/ERK) did not affect VCAM-1 and ICAM-1 expression stimulated with LPS. SP600125, inhibitor of c-Jun N-terminal kinase (JNK), reduced LPS-mediated ICAM-1 but not VCAM-1 expression. LPS reduced IkappaB${\alpha}$ ($I{\kappa}B{\alpha}$) expression, in a time-dependent manner within 1 hr. Ginsenoside Rg2 prevented the decrease of $I{\kappa}B{\alpha}$ expression stimulated with LPS. Moreover, ginsenoside Rg2 reduced LPS-mediated THP-1 monocyte adhesion to HUVEC, in a concentration-dependent manner. These data provide a novel mechanism where the ginsenoside Rg2 may provide direct vascular benefits with inhibition of leukocyte adhesion into vascular wall thereby providing protection against vascular inflammatory disease.

• Biomolecules & Therapeutics
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• v.24 no.4
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• pp.387-394
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• 2016

Sepsis, a serious clinical problem, is characterized by a systemic inflammatory response to infection and leads to organ failure. Toll-like receptor (TLR) signaling is intimately implicated in hyper-inflammatory responses and tissue injury during sepsis. Histone deacetylase (HDAC) inhibitors have been reported to exhibit anti-inflammatory properties. The aim of this study was to investigate the hepatoprotective mechanisms of trichostatin A (TSA), a HDAC inhibitor, associated with TLR signaling pathway during sepsis. The anti-inflammatory properties of TSA were assayed in lipopolysaccharide (LPS)-stimulated RAW264.7 cells. Polymicrobial sepsis was induced in mice by cecal ligation and puncture (CLP), a clinically relevant model of sepsis. The mice were intraperitoneally received TSA (1, 2 or 5 mg/kg) 30 min before CLP. The serum and liver samples were collected 6 and 24-h after CLP. TSA inhibited the increased production of tumor necrosis factor (TNF)-${\alpha}$ and interleukin (IL)-6 in LPS-stimulated RAW264.7 cells. TSA improved sepsis-induced mortality, attenuated liver injury and decreased serum TNF-${\alpha}$ and IL-6 levels. CLP increased the levels of TLR4, TLR2 and myeloid differentiation primary response protein 88 (MyD88) protein expression and association of MyD88 with TLR4 and TLR2, which were attenuated by TSA. CLP increased nuclear translocation of nuclear factor kappa B and decreased cytosolic inhibitor of kappa B ($I{\kappa}B$) protein expression, which were attenuated by TSA. Moreover, CLP decreased acetylation of $I{\kappa}B$ kinase (IKK) and increased association of IKK with $I{\kappa}B$ and TSA attenuated these alterations. Our findings suggest that TSA attenuates liver injury by inhibiting TLR-mediated inflammatory response during sepsis.

• Tuberculosis and Respiratory Diseases
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• v.65 no.6
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• pp.476-486
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• 2008

Background: TRAIL (TNF-related apoptosis inducing ligand) is a newly identified member of the TNF gene family which appears to have tumor-selective cytotoxicity due to the distinct decoy receptor system. TRAIL has direct access to caspase machinery and induces apoptosis regardless of p53 phenotype. Therefore, TRAIL has a therapeutic potential in lung cancer which frequently harbors p53 mutation in more than 50% of cases. However, it was shown that TRAIL also could activates $NF-{\kappa}B$ in some cell lines which might inhibit TRAIL-induced apoptosis. This study was designed to investigate whether TRAIL can activate $NF-{\kappa}B$ in lung cancer cell lines relatively resistant to TRAIL-induced apoptosis and inhibition of $NF-{\kappa}B$ activation using proteasome inhibitor MG132 which blocks $I{\kappa}B{\alpha}$ degradation can sensitize lung cancer cells to TRAIL-induced apoptosis. Methods: A549 (wt p53) and NCI-H1299 (null p53) lung cancer cells were used and cell viability test was done by MTT assay. Apoptosis was confirmed with Annexin V assay followed by FACS analysis. To study $NF-{\kappa}B$-dependent transcriptional activation, a luciferase reporter gene assay was used after making A549 and NCI-H1299 cells stably transfected with IgG ${\kappa}-NF-{\kappa}B$ luciferase construct. To investigate DNA binding of $NF-{\kappa}B$ activated by TRAIL, electromobility shift assay was used and supershift assay was done using anti-p65 antibody. Western blot was done for the study of $I{\kappa}B{\alpha}$ degradation. Results: A549 and NCI-H1299 cells were relatively resistant to TRAIL-induced apoptosis showing only 20~30% cell death even at the concentration 100 ng/ml, but MG132 ($3{\mu}M$) pre-treatment 1 hour prior to TRAIL addition greatly increased cell death more than 80%. Luciferase assay showed TRAIL-induced $NF-{\kappa}B$ transcriptional activity in both cell lines. Electromobility shift assay demonstrated DNA binding complex of $NF-{\kappa}B$ activated by TRAIL and supershift with p65 antibody. $I{\kappa}B{\alpha}$ degradation was proven by western blot. MG132 completely blocked both TRAIL-induced $NF-{\kappa}B$ dependent luciferase activity and DNA binding of $NF-{\kappa}B$. Conclusion: This results suggest that inhibition of $NF-{\kappa}B$ can be a potentially useful strategy to enhance TRAIL-induced tumor cell killing in lung cancer.

• Parasites, Hosts and Diseases
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• v.49 no.3
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• pp.291-294
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• 2011

Trichomonas vaginalis is a flagellated lumen-dwelling extracellular protozoan parasite that causes human trichomoniasis via sexual intercourse. Human neutrophils play a crucial role in acute tissue inflammatory responses in T. vaginalis infection. In this study, we investigated the signaling mechanism of neutrophil responses when stimulated with T. vaginalis-derived secretory products (TvSP), which were collected from $1{\times}10^7$ live trichomonads. Incubation of human neutrophils isolated from peripheral blood with TvSP induced up-regulation of IL-8 protein secretion. In addition, stimulation with TvSP induced phosphorylation of NF-${\kappa}B$ and CREB in neutrophils. Moreover, TvSP-induced IL-8 production was also significantly inhibited by pretreatment of neutrophils with $i{\kappa}B$ inhibitor or CREB inhibitor. These results suggest that transcription factors NF-${\kappa}B$ and CREB are involved in IL-8 production in human neutrophils induced by stimulation with T. vaginalis infection.

• Korean Journal of Pharmacognosy
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• v.35 no.1 s.136
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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.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.33 no.6
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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.

• Biomedical Science Letters
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• v.20 no.4
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• pp.244-249
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• 2014

Arazyme is a metalloprotease secreted by Aranicola proteolyticus that was previously shown to suppress cytokine expression of keratinocytes and endothelial cells and inhibit histopathological features in an atopic dermatitis-like animal model. However, the regulatory effects of arazyme in other allergic diseases have yet to be elucidated. In this study, we investigated whether arazyme is effective against neutrophil apoptosis in allergic diseases such as allergic rhinitis and asthma. Arazyme inhibited neutrophil apoptosis of normal subjects in a dose-dependent manner. However, the antiapoptotic effect of arazyme was reversed by LY294002, an inhibitor of PI3K, AKTi, an inhibitor of Akt, PD98059, an inhibitor of MEK, and BAY-11-7085, an inhibitor of NF-${\kappa}B$. Arazyme induced activation of NF-${\kappa}B$ via PI3K/Akt/ERK pathway. The anti-apoptotic effect of arazyme is associated with inhibition of cleavage of caspase 3 and caspase 9. Arazyme inhibited constitutive apoptosis of neutrophil in a dose-dependent manner in allergic subjects, and its mechanism was shown to be associated with PI3K/Akt/ERK/NF-${\kappa}B$. The results presented here improve our understanding of neutrophil apoptosis regulation and will facilitate development of drugs for treatment of allergic diseases.

• Journal of Korean Biological Nursing Science
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• v.14 no.2
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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.

• Archives of Pharmacal Research
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• v.29 no.7
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• pp.591-597
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• 2006

Aerial parts of Artemisia asiatica (Compositae) have been traditionally used as an oriental medicine for the treatment of inflammatory and ulcerogenic diseases. In the present study, artemisolide was isolated as a nuclear factor $(NF)-{\kappa}B$ inhibitor from A. asiatica by activity-guided fractionation. Artemisolide inhibited $NF-{\kappa}B$ transcriptional activity in lipopolysaccharide (LPS)-stimulated macrophages RAW 264.7 with an $IC_{50}$ value of $5.8\;{\mu}M$. The compound was also effective in blocking $NF-{\kappa}B$ transcriptional activities elicited by the expression vector encoding the $NF-{\kappa}B$ p65 or p50 subunits bypassing the inhibitory kB degradation signaling $NF-{\kappa}B$ activation. The macrophages markedly increased their $PGE_2$ and NO production upon exposure to LPS alone. Artemisolide inhibited LPS-induced $PGE_2$ and NO production with $IC_{50}$ values of $8.7\;{\mu}M$ and $6.4\;{\mu}M$, respectively, but also suppressed LPS-induced synthesis of cyclooxygenase (COX)-2 or inducible NO synthase (iNOS). Taken together, artemisolide is a $NF-{\kappa}B$ inhibitor that attenuates LPS-induced production of $PGE_2$ or NO via down-regulation of COX-2 or iNOS expression in macrophages RAW 264.7. Therefore, artemisolide could represent and provide the anti-inflammatory principle associated with the traditional medicine, A. asiatica.