• Title/Summary/Keyword: toll-like receptor 4 (TLR4)

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Anthocyanins from Hibiscus syriacus L. Attenuate LPS-Induced Inflammation by Inhibiting the TLR4-Mediated NF-κB Signaling Pathway

  • Karunarathne, Wisurumuni Arachchilage Hasitha Maduranga;Molagoda, Ilandarage Menu Neelaka;Lee, Kyoung Tae;Choi, Yung Hyun;Kang, Chang-Hee;Jeong, Jin-Woo;Kim, Gi-Young
    • Proceedings of the Plant Resources Society of Korea Conference
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    • 2019.10a
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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.

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Immune-modulator Effect of Zanthoxyli Pericarpium Watet Extract (천초 추출물의 면역 조절 효과)

  • Shin, Hye-Young;Chang, In-Ae;Zhang, Wen-Ji;Kim, Youn-Chul;Yun, Yong-Gab;Park, Hyun
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.22 no.2
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    • pp.410-414
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    • 2008
  • In the recently, increased concern has been focused on the pharmacology and clinical utility of herbal extracts and derivatives as a drug or adjunct to chemotherapy and immunotherapy. Here we investigated the modulatory effects of the extract of Zanthoxyli Pericarpium (ZP) in production of inflammatory mediators from Raw264.7 cells and expression of CD86, CD14, toll-like receptor (TLR)-4 from peritoneal macrophage. ZP enhanced the production of NO and $TNF-{\alpha}$ as well as mRNA expression of iNOS and $TNF-{\alpha}$. Treatment of peritoneal macrophage with ZP resulted in the enhanced cell-surface molecules expression of CD86, CD14 and TLR4. We assayed the effect of ZP in cell proliferation and production of $IFN-{\gamma},\;TNF-{\alpha}$. ZP increased Con A-induced cell proliferation and production of $IFN-{\gamma},\;TNF-{\alpha}$. These studies indicate that ZP induces macrophage activation and suggest the possible use of ZP in macrophage-based immunotherapies

Dectin-1 Stimulation Selectively Reinforces LPS-driven IgG1 Production by Mouse B Cells

  • Seo, Beom-Seok;Lee, Sang-Hoon;Lee, Ju-Eon;Yoo, Yung-Choon;Lee, Junglim;Park, Seok-Rae
    • IMMUNE NETWORK
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    • v.13 no.5
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    • pp.205-212
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    • 2013
  • Dectin-1, which specifically recognizes ${\beta}$-glucan of fungal cell walls, is a non-Toll-like receptor (TLR) pattern recognition receptor and a representative of C-type lectin receptors (CLRs). The importance of Dectin-1 in innate immune cells, such as dendritic cells and macrophages, has previously been well studied. However, the function of Dectin-1 in B cells is very poorly understood. To determine the role of Dectin-1 in B cell activation, we first investigated whether mouse B cells express Dectin-1 and then assessed the effect of Dectin-1 stimulation on B cell proliferation and antibody production. Mouse B cells express mRNAs encoding CLRs, including Dectin-1, and surface Dectin-1 was expressed in B cells of C57BL/6 rather than BALB/c strain. Dectin-1 agonists, heat-killed Candida albicans (HKCA) and heat-killed Saccharomyces cerevisiae (HKSC), alone induced B cell proliferation but not antibody production. Interestingly, HKSC, HKCA, and depleted zymosan (a selective Dectin-1 agonist) selectively enhanced LPS-driven IgG1 production. Taken together, these results suggest that, during fungal infection, ${\beta}$-glucan-stimulated Dectin-1 may cooperate with TLR4 to specifically enhance IgG1 production by mouse B cells.

Evaluation of immune responses in dairy cows immunized with an inactivated vaccine for bovine respiratory disease

  • Aganja, Ram Prasad;Seo, Kangseok;Ha, Seungmin;Yi, Young-Joo;Lee, Sang-Myeong
    • Korean Journal of Agricultural Science
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    • v.48 no.2
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    • pp.251-264
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    • 2021
  • Bovine respiratory syncytial virus (BRSV) and bovine viral diarrhea virus (BVDV) are the main viral contributors to bovine respiratory disease (BRD) with high mortality and morbidity. BRD control measures include vaccination that modulates immunological profiles reflected in blood cells, serum, and body secretions, such as milk. This study evaluated the immune responses to an inactivated BRD vaccine in lactating cows reared in a natural environment on a dairy farm. The cows were intramuscularly inoculated with the vaccine, and serum, blood, and milk were collected pre-and post-vaccination. Our study revealed a prominent increase in BRSV-specific antibodies both in serum and milk, while the change in BVDV-specific antibodies was insignificant. Serum interleukin (IL)-1β and IL-6 levels significantly decreased, but this change was not reflected in milk. Evaluation of pattern recognition receptors (PRRs) via RT-qPCR revealed downregulation of nucleotide-binding oligomerization domain 2 (NOD2). The concentrations of BRSV antibodies, BVDV antibodies, IL-2, and IL-17A in serum and milk were strongly correlated, implying a concurrent influence on both body fluids. Thus, immunological factors modulated as a result of vaccination generally measured in serum were reflected in milk, demonstrating the suitability of milk evaluation as an alternative approach for immunological observations. Furthermore, the correlation between BRSV antibodies and NOD2 and that between BVDV antibodies and toll-like receptor (TLR) 2, TLR3, TLR4, and TLR5 imply the possible role of PRRs for the assessment of the immune response developed in immunized cows reared on the farm.

Vascular Smooth Muscle Cells Secrete CXCL10 in Response to Heat Shock Protein 90 (혈관평활근세포에서 HSP90에 의한 CXCL10 증가에 관여하는 인자에 대한 연구)

  • Rhim, Byung-Yong;Kim, Do-Hyung;Kim, Koan-Hoi
    • Journal of Life Science
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    • v.21 no.5
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    • pp.664-670
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    • 2011
  • Oxidative stress results in sustained release of heat shock protein 90 (HSP90) from vascular smooth muscle cells (VSMCs). We investigated whether extracellular HSP90 predisposed VSMCs to pro-inflammatory phenotype. Exposure of human aortic smooth muscle cells to HSP90 not only significantly enhanced CXCL10 secretion but also increased CXCL10 transcription. HSP90-mediated CXCL10 secretion was attenuated by OxPAPC, a TLR-2/4 inhibitor, and curcumin, a TLR-4 dimerization inhibitor. Inhibitors of diphenyleneiodium chloride and the Akt pathway also attenuated CXCL10 secretion in response to HSP90. The gene delivery of I${\kappa}$B using recombinant adenoviruses and treatment with resveratrol, which inhibit NF-${\kappa}$B activity, significantly attenuated HSP90-induced CXCL10 secretion from VSMCs. We propose that extracellular HSP90 contributes to an inflammatory reaction in the stressed vasculature by inducing CXCL10 expression of VSMCs, and that TLR-4, Akt, and NF-${\kappa}$B play active roles in the process.

JQ1, a BET inhibitor, controls TLR4-induced IL-10 production in regulatory B cells by BRD4-NF-κB axis

  • Lee, Min Bum;Lee, Jun-Ho;Hong, Seong Hwi;You, Jueng Soo;Nam, Seung Taek;Kim, Hyun Woo;Park, Young Hwan;Lee, Dajeong;Min, Keun Young;Park, Yeong-Min;Kim, Young Mi;Kim, Hyuk Soon;Choi, Wahn Soo
    • BMB Reports
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    • v.50 no.12
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    • pp.640-646
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    • 2017
  • Regulatory B cells, also well-known as IL-10-producing B cells, play a role in the suppression of inflammatory responses. However, the epigenetic modulation of regulatory B cells is largely unknown. Recent studies showed that the bromodomain and extra-terminal domain (BET) protein inhibitor JQ1 controls the expression of various genes involving cell proliferation and cell cycle. However, the role of BET proteins on development of regulatory B cells is not reported. In this study, JQ1 potently suppressed IL-10 expression and secretion in murine splenic and peritoneal B cells. While bromodomain-containing protein 4 (BRD4) was associated with $NF-{\kappa}B$ on IL-10 promoter region by LPS stimulation, JQ1 interfered the interaction of BRD4 with $NF-{\kappa}B$ on IL-10 promoter. In summary, BRD4 is essential for toll like receptor 4 (TLR4)-mediated IL-10 expression, suggesting JQ1 could be a potential candidate in regulating IL-10-producing regulatory B cells in cancer.

Anti-Inflammatory and Anti-allergic Effects of Gnaphalium affine Extract (떡쑥 추출물의 항염증 및 항알러지 효과)

  • Roh, Kyung-Baeg;Lee, Jung-A;Park, Junho;Jung, Kwangseon;Jung, Eunsun;Park, Deokhoon
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.43 no.2
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    • pp.103-114
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    • 2017
  • Gnaphalium affine D. DON (GA) has been used as a vegetable as well as a folk medicine in East Asia. The antioxidant and anti-complementary activity of GA extract (GAE) has also been reported. However, little is known about its anti-inflammatory and anti-allergic effect and mechanism of action. In this study, we evaluated the inhibitory effects of GAE on the production of inflammatory mediators such as NO, $PGE_2$, TLR4, eotaxin-1 and histamine. Our results suggest that GAE inhibits the production of NO and $PGE_2$ by inhibiting transcriptional activation via the involvement of iNOS and COX-2. The LPS-induced expression of Toll-like receptor 4 (TLR4) was also attenuated. In addition, GAE inhibited A23187-induced histamine release from MC/9 mast cells. It also inhibited the production of eotaxin-1 induced by IL-4. Collectively, these results suggest that GAE may have considerable potential as a cosmetic ingredient with anti-inflammatory and anti-allergic properties.

Anti-inflammatory Effects of Amentoflavone on Modulation of Signal Pathways in LPS-stimulated RAW264.7 Cells

  • Lee, Eun-Jung;Shin, So-Young;Kim, Jin-Kyoung;Woo, Eun-Rhan;Kim, Yang-Mee
    • Bulletin of the Korean Chemical Society
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    • v.33 no.9
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    • pp.2878-2882
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    • 2012
  • Amentoflavone is naturally occurring bioflavonoid that is found in a number of plants. In this paper, the anti-inflammatory activity of amentoflavone in LPS-stimulated macrophages and its mode of action were examined. Using LPS-stimulated RAW264.7 macrophage cells, we found that amentoflavone exerted anti-inflammatory activities through inhibition of nitric oxide (NO) production and tumor necrosis factor (TNF)-${\alpha}$ and macrophage inflammatory protein (MIP)-2 secretion. Amentoflavone (1.0-20 ${\mu}M$) gradually inhibited nitrite production without cytotoxicity. Amentoflavone (1.0 and 10 ${\mu}M$) effectively suppressed both TNF-${\alpha}$ and MIP-2 cytokine release from LPS-stimulated RAW264.7 cells. The expression of mIL-$1{\beta}$ and mMIP-2 cytokine mRNAs was completely inhibited while expression of mMIP-1 was effectively suppressed and mTNF-${\alpha}$ expression was slightly inhibited by 10 ${\mu}M$ amentoflavone. We also demonstrated that the innate immune response to amentoflavone involves the toll-like receptor (TLR) and mitogen-activated protein kinase (MAPK) pathways. LPS-induced upregulation of p38 MAPK phosphorylation was significantly reduced by 10 ${\mu}M$ amentoflavone. These results suggest that amentoflavone exhibits effective anti-inflammatory activities through regulation of TLR4 and phosphorylation of p38 MAPKs.

Rutin alleviated lipopolysaccharide-induced damage in goat rumen epithelial cells

  • Jinshun Zhan;Zhiyong Gu;Haibo Wang;Yuhang Liu;Yanping Wu;Junhong Huo
    • Animal Bioscience
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    • v.37 no.2
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    • pp.303-314
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    • 2024
  • Objective: Rutin, also called vitamin P, is a flavonoids from plants. Previous studies have indicated that rutin can alleviate the injury of tissues and cells by inhibiting oxidative stress and ameliorating inflammation. There is no report on the protective effects of rutin on goat rumen epithelial cells (GRECs) at present. Hence, we investigated whether rutin can alleviate lipopolysaccharide (LPS)-induced damage in GRECs. Methods: GRECs were cultured in basal medium or basal medium containing 1 ㎍/mL LPS, or 1 ㎍/mL LPS and 20 ㎍/mL rutin. Six replicates were performed for each group. After 3-h culture, the GRECs were harvested to detect the relevant parameters. Results: Rutin significantly enhanced the cell activity (p<0.05) and transepithelial electrical resistance (TEER) (p<0.01) and significantly reduced the apoptosis rate (p<0.05) of LPS-induced GRECs. Rutin significantly increased superoxide dismutase, glutathione peroxidase, and catalase activity (p<0.01) and significantly decreased lactate dehydrogenase activity and reactive oxygen species and malondialdehyde (MDA) levels in LPS-induced GRECs (p<0.01). The mRNA and protein levels of interleukin 6 (IL-6), IL-1β, and C-X-C motif chemokine ligand 8 (CXCL8) and the mRNA level of tumor necrosis factor-α (TNF-α) and chemokine C-C motif ligand 5 (CCL5) were significantly increased in LPS-induced GRECs (p<0.05 or p<0.01), while rutin supplementation significantly decreased the mRNA and protein levels of IL-6, TNF-α, and CXCL8 in LPS-induced GRECs (p<0.05 or p<0.01). The mRNA level of toll-like receptor 2 (TLR2), and the mRNA and protein levels of TLR4 and nuclear factor κB (NF-κB) was significantly improved in LPS-induced GRECs (p<0.05 or p<0.01), whereas rutin supplementation could significantly reduce the mRNA and protein levels of TLR4 (p<0.05 or p<0.01). In addition, rutin had a tendency of decreasing the protein levels of CXCL6, NF-κB, and inhibitor of nuclear factor kappa-B alpha (0.05

Inhibitory Effect of a Phosphatidyl Ethanolamine Derivative on LPS-Induced Sepsis

  • Lee, Chunghyun;An, Hyun-Jung;Kim, Jung-In;Lee, Hayyoung;Paik, Sang-Gi
    • Molecules and Cells
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    • v.27 no.2
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    • pp.251-255
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    • 2009
  • Sepsis is the leading cause of death in critically ill patients. Today, around 60% of all cases of sepsis are caused by Gram-negative bacteria. The cell wall component lipopolysaccharide (LPS) is the main initiator of the cascade of cellular reactions in Gram-negative infections. The core receptors for LPS are toll-like receptor 4 (TLR4), MD-2 and CD14. Attempts have been made to antagonize the toxic effect of endotoxin using monoclonal antibodies against CD14 and synthetic lipopolysaccharides but there is as yet no effective treatment for septic syndrome. Here, we describe an inhibitory effect of a phosphatidylethanolamine derivative, PE-DTPA (phosphatidylethanolamine diethylenetriaminepentaacetate) on LPS recognition. PE-DTPA bound strongly to CD14 ($K_d$, $9.52{\times}10^{-8}M$). It dose dependently inhibited LPS-mediated activation of human myeloid cells, mouse macrophage cells and human whole blood as measured by the production of tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) and nitric oxide, whereas other phospho-lipids including phosphatidylserine and phosphatidylethanolamine had little effect. PE-DTPA also inhibited transcription dependent on $NF-{\kappa}B$ activation when it was added together with LPS, and it rescued LPS-primed mice from septic death. These results suggest that PE-DTPA is a potent antagonist of LPS, and that it acts by competing for binding to CD14.