• Molecules and Cells
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• 제43권3호
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• pp.251-263
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• 2020

Flagellin, a major structural protein of the flagellum found in all motile bacteria, activates the TLR5- or NLRC4 inflammasome-dependent signaling pathway to induce innate immune responses. Flagellin can also serve as a specific antigen for the adaptive immune system and stimulate anti-flagellin antibody responses. Failure to recognize commensal-derived flagellin in TLR5-deficient mice leads to the reduction in anti-flagellin IgA antibodies at steady state and causes microbial dysbiosis and mucosal barrier breach by flagellated bacteria to promote chronic intestinal inflammation. Despite the important role of anti-flagellin antibodies in maintaining the intestinal homeostasis, regulatory mechanisms underlying the flagellin-specific antibody responses are not well understood. In this study, we show that flagellin induces interferon-β (IFN-β) production and subsequently activates type I IFN receptor signaling in a TLR5- and MyD88-dependent manner in vitro and in vivo. Internalization of TLR5 from the plasma membrane to the acidic environment of endolysosomes was required for the production of IFN-β, but not for other pro-inflammatory cytokines. In addition, we found that anti-flagellin IgG2c and IgA responses were severely impaired in interferon-alpha receptor 1 (IFNAR1)-deficient mice, suggesting that IFN-β produced by the flagellin stimulation regulates anti-flagellin antibody class switching. Our findings shed a new light on the regulation of flagellin-mediated immune activation and may help find new strategies to promote the intestinal health and develop mucosal vaccines.

• BMB Reports
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• 제54권2호
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• pp.136-141
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• 2021

Thyroid eye disease (TED) is a complex autoimmune disease with a spectrum of signs. we previously reported that trisialoganglioside (GT)1b is significantly overexpressed in the orbital tissue of TED patients, and that exogenous GT1b strongly induced HA synthesis in orbital fibroblasts. However, the signaling pathway in GT1b-induced hyaluronic acid synthase (HAS) expression in orbital fibroblasts from TED patients have rarely been investigated. Here, we demonstrated that GT1b induced phosphorylation of Akt/mTOR in a dose-dependent manner in orbital fibroblasts from TED patients. Both co-treatment with a specific inhibitor for PI3K and siRNA knockdown of TLR2 attenuated GT1b-induced Akt phosphorylation. GT1b significantly induced HAS2 expression at both the transcriptional and translational level, which was suppressed by specific inhibitors of PI3K or Akt/mTOR, and by siRNA knockdown of TLR2. In conclusion, GT1b induced HAS2 in orbital fibroblasts from TED patients via activation of the PI3K-related signaling pathway, dependent on TLR2.

• Biomolecules & Therapeutics
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• 제31권1호
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• pp.27-39
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• 2023

Extensive research supported the therapeutic potential of curcumin, a naturally occurring compound, as a promising cytokine-suppressive anti-inflammatory drug. This study aimed to investigate the synergistic anti-inflammatory and anti-cytokine activities by combining 6-shogaol and 10-shogaol to curcumin, and associated mechanisms in modulating lipopolysaccharides and interferon-γ-induced proinflammatory signaling pathways. Our results showed that the combination of 6-shogaol-10-shogaolcurcumin synergistically reduced the production of nitric oxide, inducible nitric oxide synthase, tumor necrosis factor and interlukin-6 in lipopolysaccharides and interferon-γ-induced RAW 264.7 and THP-1 cells assessed by the combination index model. 6-shogaol-10-shogaol-curcumin also showed greater inhibition of cytokine profiling compared to that of 6-shogaol-10-shogaol or curcumin alone. The synergistic anti-inflammatory activity was associated with supressed NFκB translocation and downregulated TLR4-TRAF6-MAPK signaling pathway. In addition, SC also inhibited microRNA-155 expression which may be relevant to the inhibited NFκB translocation. Although 6-shogaol-10-shogaol-curcumin synergistically increased Nrf2 activity, the anti-inflammatory mechanism appeared to be independent from the induction of Nrf2. 6-shogaol-10-shogaol-curcumin provides a more potent therapeutic agent than curcumin alone in synergistically inhibiting lipopolysaccharides and interferon-γ induced proinflammatory mediators and cytokine array in macrophages. The action was mediated by the downregulation of TLR4/TRAF6/MAPK pathway and NFκB translocation.

• 한국자원식물학회지
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• 제25권5호
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• pp.561-567
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• 2012

본 연구는 EA에 의한 대식세포의 활성화를 매개로 한 항암효과와 항암작용과 관련된 대식세포의 면역조절효과를 확인하였다. 연구 결과 EA에 의해 RAW264.7세포 및 peritoneal macrophage 모두에서 항암효과가 증가하였으며, 증가된 대식세포의 항암효과는 TLR4 signaling을 blocking하는 CLI-095을 함께 처리하였을 때 일부 감소되었다. 이는 EA에 의한 항암 효과가 부분적으로 TLR4를 경유하는 기전으로 나타나는 것을 의미한다. 또한, EA에 대한 대식세포의 NO 분비조절효과를 측정하였으며, EA는 대식세포의 NO 생성을 증가시켰으나, 인위적으로 염증을 유발시켜 NO를 과도하게 분비한 상태에서는 NO 분비를 오히려 억제시키는 결과를 나타내었다. 이와 같이 EA에 의한 NO조절에 대한 이중 효과는 인체에 면역증강과 항염증 효과라는 긍정적인 효과를 나타내는 방향으로 조절하고 있으므로 EA를 이용한 항암요법의 보조제 및 면역보조제로써의 활용에 유익할 것으로 사료된다. 향후 EA에 대한 항암 작용 및 NO 조절에서 세포내 신호전달 작용기전에 대한 심도 있는 연구가 진행되어야 할 것으로 보인다.

• Journal of Animal Science and Technology
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• 제62권3호
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• pp.385-395
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• 2020

Polyinosinic:polycytidylic acid (poly[I:C]) can stimulate Toll-like receptor 3 (TLR3) signaling pathways. In this study, DF-1 cells were treated with poly(I:C) at various concentrations and time points to examine the comparative expression patterns of innate immune response genes. The viability of DF-1 cells decreased from 77.41% to 38.68% when cells were treated different dose of poly(I:C) from 0.1 ㎍/mL to 100 ㎍/mL for 24 h respectively. The expressions of TLR3, TLR4, TLR7, TLR15, TLR21, IL1B, and IL10 were increased in dose- and time-dependent manners by poly(I:C) treatment. On the contrary, the expression patterns of interferon regulatory factors 7 (IRF7), Jun proto-oncogene, AP-1 transcription factor subunit (JUN), Nuclear Factor Kappa B Subunit 1 (NF-κB1), and IL8L2 were varied; IRF7 and IL8L2 were increasingly expressed whereas the expressions of JUN and NF-κB1 were decreased in a dose-dependent manner after they were early induced. In time-dependent analysis, IRF7 expression was significantly upregulated from 3 h to 24 h, whereas JUN and NF-κB1 expressions settled down from 6 h to 24 h after poly(I:C) treatment although they were induced at early time from 1 h to 3 h. Poly(I:C) treatment rapidly increased the expression of IL8L2 from 3 h to 6 h with a plateau at 6 h and then the expression of IL8L2 was dramatically decreased until 24 h after poly(I:C) treatment although the expression level was still higher than the non-treated control. These results may provide the basis for understanding host response to viral infection and its mimicry system in chickens.

• Molecular & Cellular Toxicology
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• 제5권3호
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• pp.187-192
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• 2009

Toll-like receptors (TLRs) play an important role in host defense by sensing invading microbial pathogens. The stimulation of TLRs by microbial components triggers the activation of the myeloid differential factor 88 (MyD88)- and toll-interleukin-1 receptor domain-containing adapter inducing interferon-$\beta$ (TRIF)-dependent downstream signaling pathways. TLR/MyD88 signaling pathway induces the activation of nuclear factor-kappa B (NF-${\kappa}B$) and the expression of inflammatory cytokine genes, including tumor necrosis factor-alpha, interleukin (IL)-6, IL-12, and IL-$1{\beta}$. On the other hand, TLR/TRIF signaling pathway induces the delayed-activation of NF-${\kappa}B$ and interferon regulatory factor 3 (IRF3), and the expression of type I interferons (IFNs) and IFN-inducible genes. The divalent heavy metal cadmium (Cd) is clearly toxic to most mammalian organ systems, especially the immune system. Yet, the underlying toxic mechanism(s) remain unclear. Cd inhibits the MyD88-dependent pathway by ceasing the activity of inhibitor-${\kappa}B$ kinase. However, it is not known whether Cd inhibits the TRIF-dependent pathway. Presently, Cd inhibited NF-${\kappa}B$ and IRF3 activation induced by lipopolysaccharide (LPS) and polyinosinic-polycytidylic acid. Cd inhibited LPS-induced IRF3 phosphorylation and IFN-inducible genes such as interferon inducible protein-10 and regulated on activation normal T-cell expressed and secreted (RANTES). These results suggest that Cd can modulate TRIF-dependent signaling pathways of TLRs.

• 한국자원식물학회지
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• 제36권4호
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• pp.275-281
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• 2023

본 연구에서 우리는 작약 뿌리 추출물이 TLR4/PI3K/Nrf2 신호전달을 통해 p62/SQSTM1을 증가시켜 대식세포에서 자가포식을 유도한다는 것을 확인하였다. 대식세포의 자가포식 유도는 선천성과 적응성 면역 반응 간의 연결을 강화해 백신 보조제 개발에 있어서 중요한 표적으로 사용되기 때문에, 작약 뿌리 추출물은 백신개발에 필수적인 백신보조제로의 활용이 가능할 것으로 생각된다.

• Molecular & Cellular Toxicology
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• 제5권2호
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• pp.147-152
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• 2009

This study was conducted to evaluate the inflammatory mechanisms of LPS-stimulated BV-2 microglial cells. The inflammation mechanism was evaluated in BV-2 cells with or without LPS treated using the Affymetrix microarray analysis system. The microarray analysis revealed that B cell receptor signaling pathway, cytokine-cytokine receptor interaction, Jak-STAT signaling pathway, MAPK signaling pathway, Neuro-active ligand-receptor interaction, TLR signaling path-way, and T cell receptor signaling pathway-related genes were up-regulated in LPS stimulated BV-2 cells. Selected genes were validated using real time RTPCR. These results can help an effective therapeutic approach to alleviating the progression of neuro-in-flammatory diseases.

• 한국가금학회지
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• 제46권3호
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• pp.185-191
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• 2019

Nucleoporin 210(Nup210)는 근육 및 신경세포의 분화, 자기 면역 질환, 말초 T세포 항상성 등 여러 생리작용에 관여한다. 닭의 Nup210 유전자는 닭 신장조직에서 칼슘 의존성 차별 발현 유전자로 발굴되었으며, 닭의 대사 이상 질환과 Nup210의 관련 연구를 위해 Nup210 유전자의 분자유전학적 특성을 구명하고, 톨-유사수용체 3(Toll-like receptor 3(TLR3)) 자극에 의한 전사 조절을 연구하였다. 닭의 여러 조직과 배아 섬유아세포주인 DF-1 세포에서 Nup210 유전자의 전사 수준을 조사한 결과, 폐와 비장 조직에서 가장 높게 발현되었으며, Nup210의 발현은 TLR3 신호자극에 의해 증가함을 확인하였다. 또한 닭 Nup210 유전자가 코딩하는 단백질의 구조는 조류, 어류, 포유류를 포함한 여러 종과 매우 보존적이나 진화적으로 다른 포유류보다는 오리와 가장 가깝다고 추정되었다. 본 연구의 결과를 통해 닭 Nup210이 TLR3 신호시스템에 관여함을 확인하였고, 추가연구를 통해 바이러스 침입에 대한 닭 면역 메커니즘을 구명할 필요가 있다고 사료된다.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2019년도 추계학술대회
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• pp.92-92
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• 2019

Excessive or chronic inflammation contributes to the pathogenesis of many inflammatory diseases such as sepsis, rheumatoid arthritis, and ulcerative colitis. Hibiscus syriacus L. has been used as a medicinal plant in many Asian countries, even though its anti-inflammatory activity has been unclear. Therefore, we investigated the anti-inflammatory effect of anthocyanin fractions from the H. syriacus L. varieties Pulsae (PS) on the lipopolysaccharide (LPS)-induced expression of proinflammatory mediators and cytokines in RAW264.7 macrophages. PS suppressed LPS-induced nitric oxide (NO) and prostaglandin $E_2$ ($PGE_2$) secretion concomitant with downregulation of inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2) expression. Furthermore, PS inhibited the production of proinflammatory cytokines such as tumor necrosis factor-alpha ($TNF-{\alpha}$), interleukin-6 (IL-6), and IL-12 in LPS-stimulated RAW264.7 macrophages. Further study showed that PS significantly decreased LPS-induced nuclear translocation of the nuclear $factor-{\kappa}B$ ($NF-{\kappa}B$) subunits, p65 and p50. Molecular docking data showed that many anthocyanins from PS fit into the hydrophobic pocket of MD2 and bound to Toll-like receptor 4 (TLR4), indicating that PS inhibits the TLR4-MD2-mediated inflammatory signaling pathway. Especially, apigenin-7-O-glucoside most powerfully bound to MD2 and TLR4 through LYS122, LYS122, and SER127 at a distance of $2.205{\AA}$, $3.098{\AA}$, and $2.844{\AA}$ and SER441 at a distance of $2.873{\AA}$ (docking score: -8.4) through hydrogen bonding, respectively. Additionally, PS inhibited LPS-induced TLR4 dimerization/expression on the cell surface, which consequently decreased MyD88 recruitment and IRAK4 phosphorylation. PS completely blocked LPS-mediated mortality in zebrafish larvae by diminishing the recruitment of neutrophil and macrophages accompanied by low levels of proinflammatory cytokines. Taken together, our results indicate that PS attenuates LPS-mediated inflammation in both in vitro and in vivo by blocking the TLR4/MD2-MyD88/IRAK4-$NF-{\kappa}B$ axis. Therefore, PS might be used as a novel modulatory candidate for effective treatment of LPS-mediated inflammatory diseases.