• 한국식품과학회지
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• 제40권3호
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• pp.332-336
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• 2008

선천성 면역은 병원성균의 침입에 대항하기 위한 숙주의 최초 방어체계라 할 수 있다. 이러한 선천성 면역반응은 병원균들이 가지고 있는 독특한 구조를 인식하는 TLRs에 의해서 조절되어 진다고 알려져 있다. 숙주에 침입한 여러 병원성균들이 TLRs를 자극하며 이렇게 자극된 신호들은 아래로 전달되어 전사요소 $NF-{\kappa}B$의 활성화를 유도하고 결국 COX-2와 같은 염증 유발인자를 유도하여 암이나 질병을 유발하게 된다. 우리는 이번 연구를 통하여 생강 추출물중의 하나인 6-shogaol이 어떻게 $NF-{\kappa}B$ 활성화나 COX-2 발현을 조절하여 항염증 효과를 가지고 있는지를 알아보았다. 6-shogaol은 TLR2, TLR3, TLR4 agonists에 의해서 유도된 $NF-{\kappa}B$ 활성화와 COX-2 발현을 억제하였다. 이러한 결과는6-shogaol이 여러 병원균들로부터 유도되는 염증반응이나 만성적인 질병들을 조절할 수 있다는 중요한 결과를 보여주는 것이라 할 수 있다.

• 대한의생명과학회지
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• 제21권3호
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• pp.152-159
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• 2015

Der p 2, which is a major allergen of house dust mite, plays an important role in the pathogenesis of allergic disease. There is controversy regarding whether Der p 2 binds to Toll-like receptor 4 (TLR4), and its inflammatory effect has not yet been elucidated. In the current study, we examined the interaction of Der p 2 with TLR4 and the effect of Der p 2 on cytokine release in THP-1 cells and lymphocytes. Among house dust mite extracts, recombinant TLR4 protein interacted with Der p 2. The overall structure of Der p 2 is characteristic of the immunoglobulin superfamily and contains ten ${\beta}-strands$, forming a ${\beta}-cup$ fold with two anti-parallel ${\beta}-sheets$, and a short 310 helix. The two sheets can be separated, further allowing the formation of a large internal pocket, which is narrow and suitable for binding large flat molecules such as lipid-like molecules. Der p 2 caused increased secretion of IL-6, IL-8, and MCP-1, which are neutrophil survival factors, in human monocytic THP-1 cells in a time-dependent manner. Der p 2 also induces the release of cytokines in normal and allergic lymphocytes. Supernatant after treatment with Der p 2 inhibited neutrophil apoptosis. In coculture of lymphocytes with neutrophils, Der p 2 inhibited spontaneous apoptosis of allergic neutrophils. In summary, Der p 2 binds to TLR4 and induces an inflammatory response such as cytokine secretion in immune cells. These findings may enable elucidation of allergy pathogenesis by specific allergen of house dust mite.

• 생명과학회지
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• 제33권6호
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• pp.463-470
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• 2023

Desmarestia tabacoides Okamura는 전 세계적으로 널리 분포하는 갈조류 중 하나이다. 몇몇 산말류의 항종양, 멜라닌 생성 억제 및 광보호 활성에 대한 연구는 있었으나 D. tabacoides Okamura의 항염증 기전에 대해서는 보고되지 않아 본 연구에서는 LPS (lipopolysaccharide)로 자극된 RAW 264.7 세포에서 D. tabacoides Okamura 에탄올 추출물(DTEE)의 항염증 기전을 inducible nitric oxide synthase (iNOS)와 cyclooxygenase (COX)-2의 발현 및 이들의 상위신호전달물질인 nuclear factor (NF)-κB, mitogen-activated protein kinase (MAPK) 그리고 phosphoinositide-3-kinase (PI3K)/Akt의 인산화 조절 정도를 통해 분석하였다. DTEE의 처리는 세포 독성 없이 LPS로 유도된 NO와 prostaglandin (PG) E₂의 생성과 이들의 생성 효소인 iNOS 및 COX-2의 발현을 유의하게 억제하였다. 그리고 LPS에 의해 활성화된 NF-κB 및 상위 신호 전달 물질인 extracellular signal-regulated kinase (ERK), c-Jun NH₂-terminal kinase (JNK) 및 p38은 DTEE 처리에 의해 유의적으로 억제되었다. DTEE의 처리는 RAW 264.7 세포에서 LPS에 의해 활성화되는 adaptor molecule인 Toll-like receptor (TLR) 4 및 myeloid differentiation primary response (MyD) 88 또한 유의적으로 억제하였다. 이 결과를 통해 DTEE는 LPS에 의해 유도된 TLR4와 NF-κB 및 MAPK의 활성을 억제함으로써 염증 매개인자의 발현을 조절하였고, 이는 DTEE가 염증을 완화할 수 있는 기능성 식품의 소재로써 유용하게 사용될 수 있음을 시사한다.

• BMB Reports
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• 제50권5호
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• pp.263-268
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• 2017

${\beta}$-Agarase cleaves the ${\beta}$-1,4 linkages of agar to produce neoagarooligosaccharides (NAO), which are associated with various physiological functions. However, the immunological functions of NAO are still unclear. In this study, we demonstrated that ${\beta}$-agarase DagA-produced neoagarohexaose (DP6), an NAO product, promoted the maturation of dendritic cells (DCs) by Toll-like receptor 4 (TLR4). DP6 directly and indirectly enhanced the activation of natural killer (NK) cells in a TLR4-dependent manner in vitro and in vivo. Finally, the antitumor activity of DP6 against B16F1 melanoma cells was inhibited in NK cell-depletion systems by using NK-cell depleting antibodies in vivo. Collectively, the results indicated that DP6 augments antitumor immunity against B16F1 melanoma cells via the activation of DC-mediated NK cells in a TLR4-dependent manner. Thus, DP6 is a potential candidate adjuvant that acts as an immune cell modulator for the treatment of melanoma.

• Journal of Ginseng Research
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• 제46권1호
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• pp.156-166
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• 2022

Background: Panax ginseng Meyer (P. ginseng), a herb distributed in Korea, China and Japan, exerts benefits on diverse inflammatory conditions. However, the underlying mechanism and active ingredients remains largely unclear. Herein, we aimed to explore the active ingredients of P. ginseng against inflammation and elucidate underlying mechanisms. Methods: Inflammation model was constructed by lipopolysaccharide (LPS) in C57BL/6 mice and RAW264.7 macrophages. Molecular docking, molecular dynamics, surface plasmon resonance imaging (SPRi) and immunofluorescence were utilized to predict active component. Results: P. ginseng significantly inhibited LPS-induced lung injury and the expression of proinflammatory factors, including TNF-α, IL-6 and IL-1β. Additionally, P. ginseng blocked fluorescencelabeled LPS (LPS488) binding to the membranes of RAW264.7 macrophages, the phosphorylation of nuclear factor-κB (NF-κB) and mitogen-activated protein kinases (MAPKs). Furthermore, molecular docking demonstrated that ginsenoside Ro (GRo) docked into the LPS binding site of toll like receptor 4 (TLR4)/myeloid differentiation factor 2 (MD2) complex. Molecular dynamic simulations showed that the MD2-GRo binding conformation was stable. SPRi demonstrated an excellent interaction between TLR4/ MD2 complex and GRo (K_D value of 1.16 × 10^-9 M). GRo significantly inhibited LPS488 binding to cell membranes. Further studies showed that GRo markedly suppressed LPS-triggered lung injury, the transcription and secretion levels of TNF-α, IL-6 and IL-1β. Moreover, the phosphorylation of NF-κB and MAPKs as well as the p65 subunit nuclear translocation were inhibited by GRo dose-dependently. Conclusion: Our results suggest that GRo exerts anti-inflammation actions by direct inhibition of TLR4 signaling pathway.

• International Journal of Oral Biology
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• 제37권3호
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• pp.130-136
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• 2012

The GroEL heat-shock protein from Fusobacterium nucleatum, a periodontopathogen, activates risk factors for atherosclerosis in human microvascular endothelial cells (HMEC-1) and ApoE-/- mice. In this study, we analyzed the signaling pathways by which F. nucleatum GroEL induces the proinflammatory factors in HMEC-1 cells known to be risk factors associated with the development of atherosclerosis and identified the cellular receptor used by GroEL. The MAPK and NF-${\kappa}B$ signaling pathways were found to be activated by GroEL to induce the expression of interleukin-8 (IL-8), monocyte chemoattractant protein 1 (MCP-1), intercellular adhesion molecule 1 (ICAM-1), vascular cell adhesion molecule 1 (VCAM-1), E-selectin, and tissue factor (TF). These effects were inhibited by a TLR4 knockdown. Our results thus indicate that TLR4 is a key receptor that mediates the interaction of F. nucleatum GroEL with HMEC-1 cells and subsequently induces an inflammatory response via the MAPK and NF-${\kappa}B$ pathways.

• BMB Reports
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• 제46권7호
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• pp.376-381
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• 2013

It is unknown how soluble pattern-recognition receptors in blood, such as mannose-binding lectin (MBL) and ficolins, modulate mast cell-mediated inflammatory responses. We investigate how mouse MBL-A or ficolin-A regulate mouse bone marrow-derived mast cells (mBMMCs)-derived inflammatory response against bacterial lipopolysaccharide (LPS) stimulation. LPS-mediated pro-inflammatory cytokine productions on mBMMCs obtained from Toll-like receptor4 (TLR4)-deficient mice, TLR2-defficient mice, and their wildtype, were specifically attenuated by the addition of either mouse MBL-A or ficolin-A in a dose-dependent manner. However, the inhibitory effects by mouse MBL-A or ficolin-A were restored by the addition of mannose or N-acetylglucosamine, respectively. These results suggest that mouse MBL-A and ficolin-A bind to LPS via its carbohydrate-recognition domain and fibrinogen-like domain, respectively, whereby cytokine production by LPS-mediated TLR4 in mBMMCs appears to be down-regulated, indicating that mouse MBL and ficolin may have an inhibitory function toward mouse TLR4-mediated excessive inflammation on the mast cells.

• IMMUNE NETWORK
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• 제8권2호
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• pp.59-65
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• 2008

Background: Toll-like receptors (TLRs) detect microbial infection and can directly induce innate host defense responses, which are thought to play critical roles in protecting the tubotympanum from infection. However, little is known about the relationship between TLRs, which are related to innate immunity, and immunoglobulins, which are related to adaptive immunity, in recurrent otitis media with effusion (OME). We therefore investigated the expression of TLR2 and TLR4 and immunoglobulin in children with OME. Methods: The study population consisted of 72 children with OME, 31 with more than 4 episodes in 12 months or more than 3 episodes in 6 months (otitis-prone group), and 41 with fewer than 3 episodes in 12 months (non-otitis prone group). The expression in middle ear effusion of TLR2 and TLR4 mRNA, as determined by Real time- -polymerase chain reaction (RT-PCR), and the concentrations of IgG, IgA, and IgM, as determined by Enzyme-linked immunosorbent assay(ELISA), were compared between the two groups. Results: Expression of TLR2 and TLR4 mRNA was lower in the otitis prone than in the non-otitis prone group, but the difference was not statistically significant (p>0.05). Between group differences in the concentrations of IgG, IgA and IgM in effusion fluid were not significant (p>0.05), and there were no correlations between immunoglobulin concentration and the expression of TLR2 and TLR4. Conclusion: Although there was a trend toward lower expression of TLR2 and TLR4 in the otitis-prone group, the differences, and those in immunoglobulin concentration, did not differ significantly between the otitis-prone and non-prone groups.

• International Journal of Oral Biology
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• 제44권4호
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• pp.160-164
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• 2019

Porphyromonas gingivalis (Pg), Aggregatibacter actinomycetemcomitans (Aa), Tannerella forsythia (Tf), Prevotella intermedia (Pi), and Fusobacterium nucleatum (Fn) are major periodontal pathogens. Lipopolysaccharides (LPSs) from periodontal bacteria play an important role in periodontal pathogenesis by stimulating host cells to produce inflammatory cytokines. In this study, highly pure LPSs from the five major periodontopathogens were prepared, and their monocyte chemoattractant protein-1 (MCP-1) and tumor necrosis factor-α (TNF-α)-inducing activities were compared in human umbilical vein endothelial cells (HUVECs) and THP-1 macrophagic cells, respectively. In HUVECs, LPSs from Aa and Fn were potent stimulators for MCP-1 induction; however, LPSs from Pg, Pi, and Tf were much weaker MCP-1 inducers. In THP-1 cells, LPSs from Pg, Aa, and Fn were relatively strong inducers of TNF-α, whereas LPSs from Pi and Tf produced little activity. The Toll-like receptor (TLR)2/TLR4 dependency of various LPSs was also determined by measuring NF-κB reporter activity in TLR2- or TLR4-expressing 293 cells. LPSs from Aa, Fn, and Tf stimulated only TLR4; however, LPSs from Pg and Pi stimulated both TLR2 and TLR4. These results suggest that LPSs from major periodontal bacteria differ considerably in their cell-stimulating activity.

• BMB Reports
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• 제44권7호
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• pp.468-472
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• 2011

Toll-like receptors (TLRs) are pattern recognition receptors that recognize molecular structures derived from microbes and initiate innate immunity. TLRs have two downstream signaling pathways, the MyD88- and TRIF-dependent pathways. Dysregulated activation of TLRs is closely linked to increased risk of many chronic diseases. Previously, we synthesized fumaryl pyrrolidinone, (E)-isopropyl 4-oxo-4-(2-oxopyrrolidin-1-yl)-2-butenoate (IPOP), which contains a fumaric acid isopropyl ester and pyrrolidinone, and demonstrated that it inhibits the activation of nuclear factor kappa B by inhibiting the MyD88-dependent pathway of TLRs. However, the effect of IPOP on the TRIF-dependent pathway remains unknown. Here, we report the effect of IPOP on signal transduction via the TRIF-dependent pathway of TLRs. IPOP inhibited lipopolysaccharide- or polyinosinic-polycytidylic acidinduced interferon regulatory factor 3 activation, as well as interferon-inducible genes such as interferon inducible protein-10. These results suggest that IPOP can modulate the TRIF-dependent signaling pathway of TLRs, leading to decreased inflammatory gene expression.