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

Search Result 183, Processing Time 0.029 seconds

Association of Toll-Like Receptor 5 Gene Polymorphism with Susceptibility to Ossification of the Posterior Longitudinal Ligament of the Spine in Korean Population

  • Chung, Won-Suk;Nam, Dong-Hyun;Jo, Dae-Jean;Lee, Jun-Hwan
    • Journal of Korean Neurosurgical Society
    • /
    • v.49 no.1
    • /
    • pp.8-12
    • /
    • 2011
  • Objective: Ossification of the posterior longitudinal ligament (OPLL) has a strong genetic component. Specific gene polymorphisms may be associated with OPLL in several genes which regulate calcification in chondrocytes, change of extracellular collagen matrix and secretions of many growth factors and cytokines controlling bone morphogenesis. Toll-like receptor 5 (TLR5) may playa role in the pathogenesis of OPLL by intermediate nuclear factor-kappa B (NF-${\kappa}B$). The current study focused on coding single nucleotide polymorphisms (SNPs) of TLR5 for a case-control study investigating the relationship between TLR5 and OPLL in a Korean population. Methods: A total of 166 patients with OPLL and 231 controls were recruited for a case-control association study investigating the relationship between SNPs of TLR5 gene and OPLL. Four SNPs were genotyped by direct sequencing (rs5744168, rs5744169, rs2072493, and rs5744174). SNP data were analyzed using the SNPStats, SNPAnalyzer, Haploview, and Helixtree programs. Multiple logistic regression analysis with adjustment for age and gender was performed to calculate an odds ratio (OR). Results: None of SNPs were associated with OPLL in three alternative models (codominant, dominant, and recessive models; p> 0.05). A strong linkage disequilibrium block, including all 4 SNPs, was constructed using the Gabriel method. No haplotype was significantly associated with OPLL in three alternative models. Conclusion: These results suggest that Toll-like receptor 5 gene may not be associated with ossification of the posterior longitudinal ligament risk in Korean population.

Interaction of Der p 2 with Toll-like Receptor 4 and its Effect on Cytokine Secretion

  • Park, Beom Seok;Lee, Na Rae;Kim, Mun Jeong;Kim, Seong Yeol;Kim, In Sik
    • Biomedical Science Letters
    • /
    • v.21 no.3
    • /
    • pp.152-159
    • /
    • 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.

Time-dependent proteomic and genomic alterations in Toll-like receptor-4-activated human chondrocytes: increased expression of lamin A/C and annexins

  • Ha, Seung Hee;Kim, Hyoung Kyu;Nguyen, Thi Tuyet Anh;Kim, Nari;Ko, Kyung Soo;Rhee, Byoung Doo;Han, Jin
    • The Korean Journal of Physiology and Pharmacology
    • /
    • v.21 no.5
    • /
    • pp.531-546
    • /
    • 2017
  • Activation of Toll-like receptor-4 (TLR-4) in articular chondrocytes increases the catabolic compartment and leads to matrix degradation during the development of osteoarthritis. In this study, we determined the proteomic and genomic alterations in human chondrocytes during lipopolysaccharide (LPS)-induced inflammation to elucidate the underlying mechanisms and consequences of TLR-4 activation. Human chondrocytes were cultured with LPS for 12, 24, and 36 h to induce TLR-4 activation. The TLR-4-induced inflammatory response was confirmed by real-time PCR analysis of increased interleukin-1 beta ($IL-1{\beta}$), interleukin-6 (IL-6), and tumor necrosis factor alpha ($TNF-{\alpha}$) expression levels. In TLR-4-activated chondrocytes, proteomic changes were determined by two-dimensional electrophoresis and matrix-assisted laser desorption/ionization-mass spectroscopy analysis, and genomic changes were determined by microarray and gene ontology analyses. Proteomics analysis identified 26 proteins with significantly altered expression levels; these proteins were related to the cytoskeleton and oxidative stress responses. Gene ontology analysis indicated that LPS treatment altered specific functional pathways including 'chemotaxis', 'hematopoietic organ development', 'positive regulation of cell proliferation', and 'regulation of cytokine biosynthetic process'. Nine of the 26 identified proteins displayed the same increased expression patterns in both proteomics and genomics analyses. Western blot analysis confirmed the LPS-induced increases in expression levels of lamin A/C and annexins 4/5/6. In conclusion, this study identified the time-dependent genomic, proteomic, and functional pathway alterations that occur in chondrocytes during LPS-induced TLR-4 activation. These results provide valuable new insights into the underlying mechanisms that control the development and progression of osteoarthritis.

The Effect of Toll-like Receptor 2 Activation on the Non-opsonic Phagocytosis of Oral Bacteria and Concomitant Production of Reactive Oxygen Species by Human Neutrophils

  • Kim, Kap Youl;Choi, Youngnim
    • International Journal of Oral Biology
    • /
    • v.41 no.1
    • /
    • pp.17-23
    • /
    • 2016
  • Chronic/cyclic neutropenia, leukocyte adhesion deficiency syndrome, Papillon-$Lef{\grave{e}}vre$ syndrome, and $Ch{\grave{e}}diak$-Higashi syndrome are associated with severe periodontitis, suggesting the importance of neutrophils in the maintenance of periodontal health. Various Toll-like receptor (TLR) ligands are known to stimulate neutrophil function, including FcR-mediated phagocytosis. In the present study, the effect of TLR2 activation on the non-opsonic phagocytosis of oral bacteria and concomitant production of reactive oxygen species (ROS) by human neutrophils was evaluated. Neutrophils isolated from peripheral blood were incubated with Streptococcus sanguinis or Porphyromonas gingivalis in the presence of various concentrations of $Pam_3CSK_4$, a synthetic TLR2 ligand, and analyzed for phagocytosis and ROS production by flow cytometry and chemiluminescence, respectively. $Pam_3CSK_4$ significantly increased the phagocytosis of both bacterial species in a dose-dependent manner. However, the enhancing effect was greater for S. sanguinis than for P. gingivalis. $Pam_3CSK_4$ alone induced ROS production in neutrophils and also increased concomitant ROS production induced by bacteria. Interestingly, incubation with P. gingivalis and $Pam_3CSK_4$ decreased the amounts of ROS, as compared to $Pam_3CSK_4$ alone, indicating the possibility that P. gingivalis survives within neutrophils. However, neutrophils efficiently killed phagocytosed bacteria of both species despite the absence of $Pam_3CSK_4$. Although P. gingivalis is poorly phagocytosed even by the TLR2-activated neutrophils, TLR2 activation of neutrophils may help to reduce the colonization of P. gingivalis by efficiently eliminating S. sanguinis, an early colonizer, in subgingival biofilm.

Parthenolide Suppresses the Expression of Cyclooxygenase-2 and Inducible Nitric Oxide Synthase Induced by Toll-Like Receptor 2 and 4 Agonists

  • Lee, A-Neum;Park, Se-Jeong;Yun, Sae-Mi;Lee, Mi-Young;Son, Bu-Soon;Youn, Hyung-Sun
    • Biomedical Science Letters
    • /
    • v.16 no.1
    • /
    • pp.39-45
    • /
    • 2010
  • Toll-like receptors (TLRs), which are pattern recognition receptors (PRRs), recognize pathogen-associated molecular patterns (PAMPs) and regulate the activation of innate immunity. All TLR signaling pathways culminate in the activation of NF-${\kappa}B$, leading to the induction of inflammatory gene products such as cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS). Parthenolide, a sesquiterpene lactone isolated from the herb feverfew (Tanacetum parthenium), has been used as folk remedies to treat many chronic diseases for many years. In the present report, we present biochemical evidence that parthenolide inhibits the NF-${\kappa}B$ activation induced by TLR agonists and the overexpression of downstream signaling components of TLRs, MyD88, $IKK{\beta}$, and p65. Parthenolide also inhibits TLR agonists-induced COX-2 and iNOS expression. These results suggest that parthenolide can modulate the immune responses regulated by TLR signaling pathways.

Modulation of TNFSF expression in lymphoid tissue inducer cells by dendritic cells activated with Toll-like receptor ligands

  • Han, Sin-Suk;Koo, Ji-Hye;Bae, Jin-Gyu;Kim, Soo-Chan;Baik, Song;Kim, Mi-Yeon
    • BMB Reports
    • /
    • v.44 no.2
    • /
    • pp.129-134
    • /
    • 2011
  • Toll-like receptors (TLRs), which recognize structurally conserved components among pathogens, are mainly expressed by antigen-presenting cells such as dendritic cells (DCs), B cells, and macrophages. Recognition through TLRs triggers innate immune responses and influences antigen-specific adaptive immune responses. Although studies on the expression and functions of TLRs in antigen-presenting cells have been extensively reported, studies in lymphoid tissue inducer (LTi) cells have been limited. In this study, we observed that LTi cells expressed TLR2 and TLR4 mRNA as well as TLR2 protein and upregulated OX40L, CD30L, and TRANCE expression after stimulation with the TLR2 ligand zymosan or TLR4 ligand LPS. The expression of tumor necrosis factor superfamily (TNFSF) members was significantly upregulated when cells were cocultured with DCs, suggesting that upregulated TNFSF expression may contribute to antigen-specific adaptive immune responses.

Desmarestia tabacoides Ameliorates Lipopolysaccharide-induced Inflammatory Responses via Attenuated TLR4/MAPKs/NF-κB Signaling Cascade in RAW264.7 Cells (RAW 264.7 세포에서 담배잎산말의 TLR4/MAPKs/NF-κB 신호전달체계 조절을 통한 항염증 효과)

  • Hyun-Seo Yoon;Hyun An;Chung Mu Park
    • Journal of Life Science
    • /
    • v.33 no.6
    • /
    • pp.463-470
    • /
    • 2023
  • Desmarestia tabacoides Okamura is a brown macroalgae that is found worldwide. Although several genera of Desmarestia have been reported as having anti-tumorigenic, anti-melanogenic, and photoprotective properties, the anti-inflammatory activity of D. tabacoides Okamura has not yet been evaluated. In this study, we analyzed the anti-inflammatory mechanisms of D. tabacoides Okamura ethanol extract (DTEE) via the inhibition of nitric oxide (NO) and prostaglandin (PG) E2 production and the expression of their corresponding enzymes, inducible NO synthase (iNOS), and cyclooxygenase (COX)-2. In addition, their upstream signaling molecules were evaluated by Western blot analysis, such as nuclear factor (NF)-κB, mitogen-activated protein kinase (MAPK), and phosphoinositide-3-kinase (PI3K)/Akt, in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. The DTEE treatment significantly inhibited LPS-induced NO and PGE2 production as well as the expression of their corresponding enzymes, iNOS, and COX-2 without cytotoxicity. The stimulated transcription factor NF-κB and upstream signaling molecules extracellular signal-regulated kinase (ERK), c-Jun NH2-terminal kinase (JNK), and p38 were attenuated by the DTEE treatment, which was statistically significant, while Akt did not provide any inhibitory effect. Moreover, the DTEE treatment significantly mitigated the LPS-activated adaptor molecules, toll-like receptor 4 (TLR4), and myeloid differentiation primary response 88 (MyD88) in the RAW 264.7 cells. These results suggest that DTEE attenuates TLR4-mediated inflammatory responses by inhibiting NF-κB activation and suppressing MAPK phosphorylation in LPS-stimulated RAW 264.7 cells.

Toll-like Receptor 4-mediated Apoptotic Cell Death in Primary Isolated Human Cervical Cancers (부인과질환 특이적 종양의 TLR4 매개성 apoptosis 유발에 관한 연구)

  • Won, Jinyoung;Hong, Yunkyung;Park, Sookyoung;Kim, Joo-Heon;Hong, Yonggeun
    • Journal of Life Science
    • /
    • v.28 no.6
    • /
    • pp.718-725
    • /
    • 2018
  • Toll-like receptor 4 (TLR4) has been implicated in cell proliferation and apoptosis in several types of cancer. In this study, the impact of TLR4 activation on apoptotic cell death in gynecologic cancers induced by lipopolysaccharide (LPS) was investigated. Cervical cancer cell lines were produced from isolated surgical specimens supplied by Paik Hospital. The primary cultures of normal myometrium and gynecologic cancers, including cervical, endometrial, and ovarian cancers, were used to examine the differences in morphological characteristics between normal and cancerous cells. A reverse transcription polymerase chain reaction analysis was used to determine the relative expression levels of TLR4 gene involved in apoptosis-associated signaling in cervical cancer cells. The cancer cell colonies showed a tendency to reach high levels of confluency compared with normal cells. In addition, an enhanced growth rate and loss of contact inhibition were observed in gynecologic cancer cells compared with normal cells (doubling times of 16.6 hr vs. 26 hr, respectively). The expression level of ITGA5, an alpha-5 integrin marker, was upregulated in normal myometrial cells, but this tendency was not exhibited in cervical cancer cells. Furthermore, p53 tumor suppressor gene expression was upregulated, whereas TLR4 and caspase-3 gene expressions were downregulated in cervical cancer cells. Notably, the expression levels of TLR4 and caspase-3 were increased significantly in LPS-treated cancer cells compared with those in non-LPS-treated cells. These results suggest that the TLR4-mediated caspase-dependent apoptotic signaling pathway could be suggested as a therapeutic target for the treatment of gynecologic cancers, including cervical cancers.

Compound K Rich Fractions Regulate NF-κB-dependent Inflammatory Responses and Protect Mice from Endotoxin-induced Lethal Shock

  • Yang, Chul-Su;Yuk, Jae-Min;Ko, Sung-Ryong;Cho, Byung-Goo;Sohn, Hyun-Joo;Kim, Young-Sook;Wee, Jae-Joon;Do, Jae-Ho;Jo, Eun-Kyeong
    • Journal of Ginseng Research
    • /
    • v.32 no.4
    • /
    • pp.315-323
    • /
    • 2008
  • In the previous studies, we isolated the compound K rich fractions (CKRF) and showed that CKRF inhibited Toll-like receptor (TLR) 4- or TLR9-induced inflammatory signaling. To extend our previous studies,1) we investigated the molecular mechanisms of CKRF in the TLR4-associated signaling via nuclear factor (NF)-${\kappa}B$, and in vivo role of CKRF for induction of tolerance in lipopolysaccharide (LPS)-induced septic shock. In murine bone marrow-dervied macrophages, CKRF significantly inhibited the induction of mRNA expression of proinflammatory mediators such as tumor necrosis factor-${\alpha}$, interleukin-6, cyclooxygenase-2, and inducible nitric oxide synthase. In addition, CKRF significantly attenuated the transcriptional activities of TLR4/LPS-induced NF-${\kappa}B$. Nuclear translocation of NF-${\kappa}B$ in response to LPS stimulation was significantly abrogated by pre-treatment with CKRF. Furthermore, CKRF inhibited the recruitment of p65 to the interferon-sensitive response element flanking region in response to LPS. Finally, oral administration of CKRF significantly protected mice from Gram-negative bacterial LPS-induced lethal shock and inhibited systemic inflammatory cytokine levels. Together, these results demonstrate that CKRF modulates the TLR4-dependent NF-${\kappa}B$ activation, and suggest a therapeutic role for Gram-negative septic shock.

Compound K (CK) Rich Fractions from Korean Red Ginseng Inhibit Toll-like Receptor (TLR) 4- or TLR9-mediated Mitogen-activated Protein Kinases Activation and Pro-inflammatory Responses in Murine Macrophages (고려홍삼으로부터 분리한 compound K 함유분획에 의한 대식세포의 toll-like receptor-의존성 신호전달로 활성조절 분석)

  • Yang, Chul-Su;Ko, Sung-Ryong;Cho, Byung-Goo;Lee, Ji-Yeon;Kim, Ki-Hye;Shin, Dong-Min;Yuk, Jae-Min;Sohn, Hyun-Joo;Kim, Young-Sook;Wee, Jae-Joon;Do, Jae-Ho;Jo, Eun-Kyeong
    • Journal of Ginseng Research
    • /
    • v.31 no.4
    • /
    • pp.181-190
    • /
    • 2007
  • Compound K (CK), a protopanaxadiol ginsenoside metabolite, was previously shown to have immunomodulatory effects. In this study, we isolated the CK rich fractions (CKRF) from Korean Red Ginseng and investigated the regulation of CKRF-mediated inflammatory signaling during Toll-like receptor (TLR)-mediated cellular activation. Among various TLR ligands, CKRF considerably abrogated TLR4- or TLR9-induced inflammatory signaling. Both LPS and CpG-containing oligodeoxynucleotides (CpG-ODN) stimulation rapidly activates mitogen-activated protein kinases [MAPKs; extracellular signal-regulated kinases 1/2 and p38], NF-${\kappa}B$, and expression of pro-inflammatory cytokines tumor necrosis factor-${\alpha}$, and interleukin-6 in murine bone marrow-derived macrophages (BMDMs) in a time- and dose-dependent manner. Of interest, pre-treatment of CKRF in either LPS/TLR4- or CpG-ODN/TLR9-stimulated macrophages substantially attenuated the LPS-induced inflammatory cytokine production and mRNA expressions, as well as MAPK and NF-${\kappa}B$ activation. To our knowledge, this is the first description of the inhibitory roles for CKRF in TLR4- or TLR9-associated signaling in BMDMs. Collectively, these results demonstrate that CKRF specifically modulates distinct TLR4 and TLR9-mediated inflammatory responses, and further studies are urgently needed for their in vivo roles for potential therapeutic uses, such as in systemic inflammatory syndromes.