• Journal of Microbiology and Biotechnology
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• v.28 no.9
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• pp.1554-1562
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• 2018

The type I interferons (IFNs) play a vital role in activation of innate immunity in response to viral infection. Accordingly, viruses have evolved to employ various survival strategies to evade innate immune responses induced by type I IFNs. For example, hepatitis E virus (HEV) encoded papain-like cysteine protease (PCP) has been shown to inhibit IFN activation signaling by suppressing K63-linked de-ubiquitination of retinoic acid-inducible gene I (RIG-I) and TANK-binding kinase 1 (TBK1), thus effectively inhibiting down-stream activation of IFN signaling. In the present study, we demonstrated that HEV inhibits polyinosinic-polycytidylic acid (poly(I:C))-induced $IFN-{\beta}$ transcriptional induction. Moreover, by using reporter assay with individual HEV-encoded gene, we showed that HEV methyltransferase (MeT), a non-structural protein, significantly decreases RIG-I-induced $IFN-{\beta}$ induction and $NF-{\kappa}B$ signaling activities in a dose-dependent manner. Taken together, we report here that MeT, along with PCP, is responsible for the inhibition of RIG-I-induced activation of type I IFNs, expanding the list of HEV-encoded antagonists of the host innate immunity.

• The Korean Journal of Physiology and Pharmacology
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• v.21 no.1
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• pp.117-124
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• 2017

The present study aimed to show that pro-inflammatory cytokines [tumor necrosis factor (TNF)-${\alpha}$, interferon (IFN)-${\gamma}$, and interleukin (IL)-$1{\beta}$] synergistically induce the production of nitric oxide (NO) production in mouse mesangial cells, which play an important role in inflammatory glomerular injury. We also found that co-treatment with cytokines at low doses (TNF-${\alpha}$; 5 ng/ml, IFN-${\gamma}$; 5 ng/ml, and IL-$1{\beta}$; 1.25 U/ml) synergistically induced NO production, whereas treatment with each cytokine alone did not increase NO production at doses up to 100 ng/ml or 50 U/ml. Silymarin, a polyphenolic flavonoid isolated from milk thistle (Silybum marianum), attenuates cytokine mixture (TNF-${\alpha}$, IFN-${\gamma}$, and IL-$1{\beta}$)-induced NO production. Western blot and RT-PCR analyses showed that silymarin inhibits inducible nitric oxide synthase (iNOS) expression in a dose-dependent manner. Silymarin also inhibited extracellular signal-regulated protein kinase-1 and -2 (ERK1/2) phosphorylation. Collectively, we have demonstrated that silymarin inhibits NO production in mouse mesangial cells, and may act as a useful anti-inflammatory agent.

• Journal of Ginseng Research
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• v.40 no.4
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• pp.437-444
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• 2016

Background: Although Korean Red Ginseng (KRG) has been traditionally used for a long time, its anti-inflammatory role and underlying molecular and cellular mechanisms have been poorly understood. In this study, the anti-inflammatory roles of KRG-derived components, namely, water extract (KRG-WE), saponin fraction (KRG-SF), and nonsaponin fraction (KRG-NSF), were investigated. Methods: To check saponin levels in the test fractions, KRG-WE, KRG-NSF, and KRG-SF were analyzed using high-performance liquid chromatography. The anti-inflammatory roles and underlying cellular and molecular mechanisms of these components were investigated using a macrophage-like cell line (RAW264.7 cells) and an acute gastritis model in mice. Results: Of the tested fractions, KGR-SF (but not KRG-NSF and KRG-WE) markedly inhibited the viability of RAW264.7 cells, and splenocytes at more than 500 mg/mL significantly suppressed NO production at $100{\mu}g/mL$, diminished mRNA expression of inflammatory genes such as inducible nitric oxide synthase, cyclooxygenase-2, tumor necrosis factor-${\alpha}$, and interferon-${\beta}$ at $200{\mu}g/mL$, and completely blocked phagocytic uptake by RAW264.7 cells. All three fractions suppressed luciferase activity triggered by interferon regulatory factor 3 (IRF3), but not that triggered by activator protein-1 and nuclear factor-kappa B. Phospho-IRF3 and phospho-TBK1 were simultaneously decreased in KRG-SF. Interestingly, all these fractions, when orally administered, clearly ameliorated the symptoms of gastric ulcer in HCl/ethanol-induced gastritis mice. Conclusion: These results suggest that KRG-WE, KRG-NSF, and KRG-SF might have anti-inflammatory properties, mostly because of the suppression of the IRF3 pathway.

• The korean journal of orthodontics
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• v.33 no.3 s.98
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• pp.199-210
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• 2003

Tooth movement is the result of bone metabolism in the periodontium, where various cytokines take important roles. Interleukin-6(II-6) and nitrous oxide (NO) were reported to be secreted from osteoblasts in the process of bone resorption. The mechanism of the process has not been clearly understood, but the activation of mitogen-activated protein kinase (MAPK) was known to be an important process in the release of the inflammatory cytotines in macrophages. In this regard, to prove the role of MAPK in the release of IL-6 and NO in MC3T3E-1 osteoblasts, Northern blot analysis, Western blot analysis and immune complex kinase assay were used. As a result, the treatment of MC3T3E-1 osteoblast cultures with combined $interferon-\gamma(IFN-\gamma)$, lipopolysaccharide (LPS) and tumor necrosis $factor-\alpha(TNF-\alpha)$ induces expressions of inducible nitric oxide synthase (iNOS) and IL-6, resulting in sustained releases of large amounts of NO and IL-6. However, $IFN-\gamma,\;LPS,\;and\;TNF-\alpha$ individually induce a non-detectable or small amount of NO and IL-6 in MC3T3E-1 osteoblasts. The role of MAPK activation in the early intracellular signal transduction involved in iNOS and IL-6 transcription in the combined agents-stimulated osteoblasts has been investigated. The p38 MAPK pathway is specifically involved in the combined agents-induced NO and IL-6 release, since NO and IL-6 release in the presence of a specific inhibitor of p38 MAPK, 4-(4-fluorophenyl)-2-(4-metylsulfinylphenyl)-5-(4-metylsulfinylphenyl)-5-(4-pyridyl)imidazole) (SB203580), were significantly diminished. In contrast, PD98059, a specific inhibitor of MEK1, had no effect on NO and IL-6 release. Northern blot analysis showed that the p3a MAPK pathway controlled the iNOS and IL-6 transcription level. These data suggest that p38 MAPK play an important role in the secretion of NO and IL-6 in $LPS/IFN{\gamma}-or\;TNF-\gamma-treated\;MC3T3E-1$ osteoblasts.

• Journal of Life Science
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• v.21 no.1
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• pp.22-30
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• 2011

Apolipoprotein A-I (apoA-I) has anti-inflammatory and anti-oxidative properties. This study was designed to investigate whether apoA-I affects apoptosis and cytokine production of human blood neutrophils in an in vitro culture system. Spontaneous apoptosis of neutrophils was significantly delayed by apoA-I. In addition, high density lipoprotein containing apoA-I also delayed apoptosis of neutrophils. Apoptosis of neutrophils was inhibited by anti-scavenger receptor type B-I antibodies. The amounts of interleukin-8, interferon (IFN)-inducible protein 10 (IP-10), and tumor necrosis factor-$\alpha$ (TNF-$\alpha$) in the supernatants of cultured neutrophils treated with apoA-I were significantly increased. Combined treatment of neutrophils with IFN-$\gamma$ and apoA-I produced higher amounts of IP-10 and TNF-$\alpha$ than did treatment with IFN-$\gamma$ or apoA-I alone. The present study reveals that apoA-I activates neutrophils to produce cytokines and delays spontaneous apoptosis of neutrophils. These findings suggest that apoA-I, although a well-known negative acute-phase protein, has a pro-inflammatory effect in neutrophils.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.3
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• pp.306-313
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• 2017

Purple bamboo salt (PuBS) is commonly used as a medicinal food in Korea and has beneficial potentials such as antioxidant and anti-inflammatory effects. Rubus coreanus is called Bokbunja, which is used as a traditional medicine for treating asthma, impotence, and allergic diseases in Korea. The aim of present study was to investigate the immunostimulatory effect of PuBS composed with Rubus coreanus (PuBS-R). We performed comparative analysis between PuBS and PuBS-R in Raw264.7 cells, which is a mouse macrophage cell line, and peritoneal macrophages isolated primarily from the mouse peritoneal cavity. We evaluated cytotoxicity and the immune cytokine response in PuBS- and PuBS-R-treated cells. Both PuBS and PuBS-R did not have any cytotoxicity in Raw264.7 cells up to $500{\mu}g/mL$. Gene and protein levels of immune cytokines such as tumor necrosis $factor-{\alpha}$ ($TNF-{\alpha}$), $interferon-{\gamma}$ ($IFN-{\gamma}$), interleukin (IL)-10, and IL-12 were significantly elevated by PuBS-R more than PuBS in Raw264.7 cells. Moreover, we evaluated the immunostimulatory effects of PuBS-R on mouse primary peritoneal macrophages. Protein levels of inducible nitric oxide synthase, $TNF-{\alpha}$, $IFN-{\gamma}$, IL-10, and IL-12 were significantly higher in PuBS-R-treated peritoneal macrophages than PuBS-treated peritoneal macrophages. These results suggest the potential immunostimulatory effect of PuBS-R for immunity against harmful infection.

• IMMUNE NETWORK
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• v.1 no.2
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• pp.116-125
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• 2001

Background: Nitric oxide (NO) production has been described as a double-edged sword eliciting both pro- and anti-inflammatory effects in different immune reactions. This work was undertaken to investigate the immunoregulatory role of NO in experimental allergic encephalomyelitis (EAE) and experimental allergic uveitis (EAU). Method: We examined whether molsidomine (MSDM), a NO donor, administration to the myelin basic protein (MBP)- or interphotoreceptor retinoid binding protein (IRBP)-immunized rats could suppress EAE development by shifting toward the Th2 cytokine response. In the EAE experiments, the rats were treated orally with MSDM (10 mg/kg/day) at the early stage (-1~4 days) or throughout the experimental period (-1~15 days). Results: This resulted in significant amelioration of the disease and mild clinical symptoms, while MBP-immunization without MSDM administration showed severe EAE development. A marked reduction in inflammation was also observed in the spinal cord, indicating the crucial role of NO in the pathogenesis of EAE in in vivo. In the EAU experiments, a 24 h pre-treatment with MSDM prior to IRBP immunization resulted in significant inhibition of the disease. Furthermore, MSDM administration for 2 1 days completely reduced the incidence and severity of EAU. To investigate whether MSDM could modulate cytokine switching from Th 1 to Th2, culture supernatants of MBP- or IRBP-stimulated inguinal lymphocytes were analyzed. MSDM treatment enhanced IL-10 secretion but decreased IFN-${\gamma}$. IL-4 was undetectable in all groups. In contrast, the MBP-or IRBP-immunized rats without MSDM secreted high concentrations of IFN-${\gamma}$, but low concentrations of IL-10. Conclusion: In conclusion, NO administation suppresses EAE and EAU by modulating the Th1/Th2 balance during inflammatory immune responses. This work further suggests that NO may be useful in the therapeutic control of autoimmune disease.

• International Journal of Oral Biology
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• v.33 no.4
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• pp.163-177
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• 2008

Periodontal disease, a form of chronic inflammatory bacterial infectious disease, is known to be a risk factor for cardiovascular disease (CVD). Porphyromonas gingivalis has been implicated in periodontal disease and widely studied for its role in the pathogenesis of CVD. A previous study demonstrating that periodontopathic P. gingivalis is involved in CVD showed that invasion of endothelial cells by the bacterium is accompanied by an increase in cytokine production, which may result in vascular atherosclerotic changes. The present study was performed in order to further elucidate the role of P. gingivalis in the process of atherosclerosis and CVD. For this purpose, invasion of human aortic smooth muscle cells (HASMC) by P. gingivalis 381 and its isogenic mutants of KDP150 ($fimA^-$), CW120 ($ppk^-$) and KS7 ($relA^-$) was assessed using a metronidazole protection assay. Wild type P. gingivalis invaded HASMCs with an efficiency of 0.12%. In contrast, KDP150 failed to demonstrate any invasive ability. CW120 and KS7 showed relatively higher invasion efficiencies, but results for these variants were still negligible when compared to the wild type invasiveness. These results suggest that fimbriae are required for invasion and that energy metabolism in association with regulatory genes involved in stress and stringent response may also be important for this process. ELISA assays revealed that the invasive P. gingivalis 381 increased production of the proinflammatory cytokine interleukin (IL)-$1{\beta}$ and the chemotactic cytokines (chemokine) IL (interleukin)-8 and monocyte chemotactic (MCP) protein-1 during the 30-90 min incubation periods (P<0.05). Expression of RANTES (regulation upon activation, normal T cell expressed and secreted) and Toll-like receptor (TLR)-4, a pattern recognition receptor (PRR), was increased in HASMCs infected with P. gingivalis 381 by RT-PCR analysis. P. gingivalis infection did not alter interferon-$\gamma$-inducible protein-10 expression in HASMCs. HASMC nonspecific necrosis and apoptotic cell death were measured by lactate dehydrogenase (LDH) and caspase activity assays, respectively. LDH release from HASMCs and HAMC caspase activity were significantly higher after a 90 min incubation with P. gingivalis 381. Taken together, P. gingivalis invasion of HASMCs induces inflammatory cytokine production, apoptotic cell death, and expression of TLR-4, a PRR which may react with the bacterial molecules and induce the expression of the chemokines IL-8, MCP-1 and RANTES. Overall, these results suggest that invasive P. gingivalis may participate in the pathogenesis of atherosclerosis, leading to CVD.

• The Korea Journal of Herbology
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• v.29 no.4
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• pp.83-89
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• 2014

Objectives : The purpose of this study was to investigate effects of Houttuyniae Herba water extract (HC) on calcium release and production of various inflammatory mediators such as nitric oxide (NO), interferon-inducible protein (IP)-10, platelet derived growth factor (PDGF)-BB, keratinocyte-derived chemokine (KC), vascular endothelial growth factor (VEGF), interleukin (IL)-4, and IL-5 in lipopolysaccharide (LPS)-induced RAW 264.7 mouse macrophages. Methods : NO production was measured by Griess reagent assay. Intracellular calcium level was measured with Fluo-4 assay. Levels of cytokines were measured by High-throughput multiplex bead array cytokine assay based on xMAP (multi-analyte profiling beads) technology. Results : HC significantly decreased NO production for 24 hrs incubation at the concentrations of 10, 25, 50, 100, and $200{\mu}/mL$ in LPS-induced RAW 264.7 (P < 0.05). HC significantly decreased production of IP-10, KC, VEGF, and PDGF-BB for 24 hrs incubation at the concentrations of 50, 100, and $200{\mu}/mL$ in LPS-induced RAW 264.7 (P < 0.05). HC also significantly decreased intracellular calcium release for 24 hrs incubation at the concentrations of 25, 50, 100, and $200{\mu}/mL$ in LPS-induced RAW 264.7 (P < 0.05). But HC did not show any significant effect on production of IL-4 and IL-5 in LPS-induced RAW 264.7. Conclusions : The results suggested that HC has anti-inflammatory property related with its inhibition on the production of NO, IP-10, KC, VEGF, and PDGF-BB in LPS-induced macrophages via calcium pathway.

• The Korea Journal of Herbology
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• v.28 no.6
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• pp.101-109
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• 2013

Objectives : The purpose of this study was to investigate the effects of Polygoni Multiflori Radix Water Extract (PM) on the production of inflammatory mediators in RAW 264.7 mouse macrophages induced by lipopolysaccharide (LPS). Method : We examined effect of PM Extract on the cell viability of RAW 264.7 cells. Futhermore, we investigated anti-inflammatory effect of PM Extract by the production of proinflammatory cytokines such as NO, intracellular calcium, interleukin(IL)-$1{\alpha}$, IL-3, IL-$1{\beta}$, IL-6, interferon inducible protein-10(IP-10), keratinocyte-derived chemokine(KC) and vascular endothelial growth factor(VEGF). Result : No significant changes have been found in the mouse macrophge cell viability by the PM Extract at the concentration of 25, 50, 100 and $200{\mu}g/mL$. The water extract of PM significantly inhibited the production of NO and intracellular calcium in the LPS-induced macrophages at the concentration of 25, 50, 100 and $200{\mu}g/mL$. The water extract of PM significantly inhibited the production of IL-$1{\alpha}$, IL-${\beta}$, IL-3, IP-10, KC, VEGF in the LPS-induced macrophages at the concentration of 50, 100, and $200{\mu}g/mL$; IL-6 at the concentration of 100 and $200{\mu}g/mL$ ; and IL-17 at $200{\mu}g/mL$. Conclusion : The water extract of PM significantly inhibited the production of NO, intracellular calcium, IL-$1{\alpha}$, IL-3, IL-${\beta}$, IP-10, KC, VEGF at the concentration of 50 ㎍/mL or higher in the LPS-induced macrophages with no changes in the cell viability of them. These results suggest that water extract of Polygoni Multiflori Radix has anti-inflammatory effect regulating the production of proinflammatory cytokines in the LPS-induced macrophages.