• 제목/요약/키워드: Toll-like receptor 4

검색결과 220건 처리시간 0.023초

Association of Toll-like receptor 2-positive monocytes with coronary artery lesions and treatment nonresponse in Kawasaki disease

  • Kang, Soo Jung;Kim, Nam Su
    • Clinical and Experimental Pediatrics
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    • 제60권7호
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    • pp.208-215
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    • 2017
  • Purpose: Activation of Toll-like receptor 2 (TLR2) present on circulating monocytes in patients with Kawasaki disease (KD) can lead to the production of proinflammatory cytokines and interleukin-10 (IL-10). We aimed to determine the association of the frequency of circulating TLR2+/ CD14+ monocytes (FTLR2%) with the outcomes of KD, as well as to compare FTLR2% to the usefulness of sIL-10. Methods: The FTLR2% in patients with KD was measured by flow cytometry. Serum levels of IL-10 (sIL-10) were determined in 31 patients with KD before the initial treatment with intravenous immunoglobulin (IVIG) and in 21 febrile controls by using enzyme-linked immunosorbent assay. Patients were classified as having coronary artery lesions (CALs) based on the maximal internal diameters of the proximal right coronary artery and proximal left anterior descending coronary artery one month after the initial diagnosis. Results: We found that FTLR2% greater than 92.62% predicted CALs with 80% sensitivity and 68.4% specificity, whereas FTLR2% more than 94.61% predicted IVIG resistance with 66.7% sensitivity and 71.4% specificity. Moreover, sIL-10 more than 15.52 pg/mL predicted CALs and IVIG resistance with 40% and 66.7% sensitivity, respectively, and 73.7% and 76.2% specificity, respectively. Conclusion: We showed that measuring FTLR2% before the initial treatment could be useful in predicting CAL development with better sensitivity than sIL-10 and with results comparable to sIL-10 results for the prediction of IVIG resistance in patients with KD. However, further studies are necessary to validate FTLR2% as a marker of prognosis and severity of KD.

Berberine Prevents Intestinal Mucosal Barrier Damage During Early Phase of Sepsis in Rat through the Toll-Like Receptors Signaling Pathway

  • Li, Guo-Xun;Wang, Xi-Mo;Jiang, Tao;Gong, Jian-Feng;Niu, Ling-Ying;Li, Ning
    • The Korean Journal of Physiology and Pharmacology
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    • 제19권1호
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    • pp.1-7
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    • 2015
  • Our previous study has shown berberine prevents damage to the intestinal mucosal barrier during early phase of sepsis in rat through mechanisms independent of the NOD-like receptors signaling pathway. In this study, we explored the regulatory effects of berberine on Toll-like receptors during the intestinal mucosal damaging process in rats. Male Sprague-Dawlay (SD) rats were treated with berberine for 5 d before undergoing cecal ligation and puncture (CLP) to induce polymicrobial sepsis. The expression of Toll-like receptor 2 (TLR 2), TLR 4, TLR 9, the activity of nuclear factor-kappa B ($NF-{\kappa}B$), the levels of selected cytokines and chemokines, percentage of cell death in intestinal epithelial cells, and mucosal permeability were investigated at 0, 2, 6, 12 and 24 h after CLP. Results showed that the tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) and interleukin-6 (IL-6) level were significantly lower in berberine-treated rats compared to the control animals. Conversely, the expression level of tight junction proteins, percentage of cell death in intestinal epithelial cells and the mucosal permeability were significantly higher in berberine-treated rats. The mRNA expression of TLR 2, TLR 4, and TLR 9 were significantly affected by berberine treatment. Our results indicate that pretreatment with berberine attenuates tissue injury and protects the intestinal mucosal barrier in early phase of sepsis and this may possibly have been mediated through the TLRs pathway.

Genomic DNA Extracted from Lactiplantibacillus plantarum Attenuates Porphyromonas gingivalis Lipopolysaccharide (LPS)-Induced Inflammatory Responses via Suppression of Toll-Like Receptor (TLR)-Mediated Mitogen-Activated Protein Kinase (MAPK) and Nuclear Factor-κB (NF-κB) Signaling Pathways

  • Young Hyeon Choi;Bong Sun Kim;Seok-Seong Kang
    • 한국축산식품학회지
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    • 제43권5호
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    • pp.938-947
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    • 2023
  • In the present study, we aimed to examine the inhibition of genomic DNA from Lactiplantibacillus plantarum (LpDNA) on Porphyromonas gingivalis lipopolysaccharide (PgLPS)-induced inflammatory responses in RAW264.7 cells. Pretreatment with LpDNA for 15 h significantly inhibited PgLPS-induced mRNA expression and protein secretion of interleukin (IL)-1β, IL-6, and monocyte chemoattractant protein-1. LpDNA pretreatment also reduced the mRNA expression of Toll-like receptor (TLR)2 and TLR4. Furthermore, LpDNA inhibited the phosphorylation of mitogen-activated protein kinases (MAPKs) and the activation of nuclear factor-κB (NF-κB) induced by PgLPS. Taken together, these findings demonstrate that LpDNA attenuates PgLPS-induced inflammatory responses by regulating MAPKs and NF-κB signaling pathways through the suppression of TLR2 and TLR4 expression.

강황 추출물의 비알코올성 지방간 질환 개선 효과 (Improvement Effect of Non-alcoholic Fatty Liver Disease by Curcuma longa L. Extract)

  • 이영섭;이대영;권동렬;강옥화
    • 한국약용작물학회지
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    • 제28권4호
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    • pp.276-286
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    • 2020
  • Background: Non-alcoholic fatty liver disease (NAFLD) is a chronic liver disease associated with multiple metabolic disorders. The medicinal plant Curcuma longa L. is widely distributed in Asia and has been used to treat a spectrum diseases in clinical practice. To date, there are inadequate reports of the effects of C. longa 50% EtOH extract (CE) on NAFLD. Therefore, in this study, we evaluate the CE on an NAFLD animal and elucidate the mechanism of action. Methods and Results: C57BL/6J mice fed a methionine-choline deficient diet (MCD) were treated with CE or milk thistle, and changes in inflammation and stetosis were assessed. Experimental animals were divided into six group (n = 10); Normal, MCD, MCD + CE 50 mg/kg/day (CE 50), MCD + CE 100 mg/kg/day (CE 100), MCD + CE 150 mg/kg/day (CE 150), and the Control, MCD + Milk thistle 150 mg/kg/day (MT 150). Body weight, liver weight, liver function, and histological changes were assessed in experimental animals. Quantitative real-time polymerase chain reaction and western blot analyses were performed on samples collected after 4 weeks of treatment. We observed that CE administration improved MCD-diet-induced lipid accumulation, and triglyceride (TG) and total cholesterol (TC) levels in serum. Treatment with CE also decreased hepatic lipogenesis through modulation of the sterol regulatory element binding protein-1 (SREBP-1), CCAAT-enhancer binding protein α (C/EBPα), fatty acid synthase (FAS), and peroxisome proliferator-activated receptor γ (PPARγ) expresion. In addition, the use of CE increased adenosine monophosphate-activated protein kinase (AMPK) phosphorylation and inhibited the up-regulation of toll-like receptor (TLR)-2 and TLR-4 signaling and the production of inflammatory mediators. Conclusions: In this report, we observed that CE regulated lipid accumulation in an MCD dietinduced NAFLD model by decreasing lipogenesis. These data suggeste that CE could effectively protect mice against MCD-induced NAFLD, by inhibiting the TLR-2 and TLR-4 signaling cascades.

Regulation of toll-like receptors expression in muscle cells by exercise-induced stress

  • Park, Jeong-Woong;Kim, Kyung-Hwan;Choi, Joong-Kook;Park, Tae Sub;Song, Ki-Duk;Cho, Byung-Wook
    • Animal Bioscience
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    • 제34권10호
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    • pp.1590-1599
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    • 2021
  • Objective: This study investigates the expression patterns of toll-like receptors (TLRs) and intracellular mediators in horse muscle cells after exercise, and the relationship between TLRS expression in stressed horse muscle cells and immune cell migration toward them. Methods: The expression patterns of the TLRs (TLR2, TLR4, and TLR8) and downstream signaling pathway-related genes (myeloid differentiation primary response 88 [MYD88]; activating transcription factor 3 [ATF3]) are examined in horse tissues, and horse peripheral blood mononuclear cells (PBMCs), polymorphonuclear cells (PMNs) and muscles in response to exercise, using the quantitative reverse transcription-polymerase chain reaction (qPCR). Expressions of chemokine receptor genes, i.e., C-X-C motif chemokine receptor 2 (CXCR2) and C-C motif chemokine receptor 5 (CCR5), are studied in PBMCs and PMNs. A horse muscle cell line is developed by transfecting SV-T antigen into fetal muscle cells, followed by examination of muscle-specific genes. Horse muscle cells are treated with stressors, i.e., cortisol, hydrogen peroxide (H2O2), and heat, to mimic stress conditions in vitro, and the expression of TLR4 and TLR8 are examined in stressed muscle cells, in addition to migration activity of PBMCs toward stressed muscle cells. Results: The qPCR revealed that TLR4 message was expressed in cerebrum, cerebellum, thymus, lung, liver, kidney, and muscle, whereas TLR8 expressed in thymus, lung, and kidney, while TLR2 expressed in thymus, lung, and kidney. Expressions of TLRs, i.e., TLR4 and TLR8, and mediators, i.e., MYD88 and ATF3, were upregulated in muscle, PBMCs and PMNs in response to exercise. Expressions of CXCR2 and CCR5 were also upregulated in PBMCs and PMNs after exercise. In the muscle cell line, TLR4 and TLR8 expressions were upregulated when cells were treated with stressors such as cortisol, H2O2, and heat. Migration of PBMCs toward stressed muscle cells was increased by exercise and oxidative stresses, and combinations of these. Treatment with methylsulfonylmethane (MSM), an antioxidant on stressed muscle cells, reduced migration of PBMCs toward stressed muscle cells. Conclusion: In this study, we have successfully cultured horse skeletal muscle cells, isolated horse PBMCs, and established an in vitro system for studying stress-related gene expressions and function. Expression of TLR4, TLR8, CXCR2, and CCR5 in horse muscle cells was higher in response to stressors such as cortisol, H2O2, and heat, or combinations of these. In addition, migration of PBMCs toward muscle cells was increased when muscle cells were under stress, but inhibition of reactive oxygen species by MSM modulated migratory activity of PBMCs to stressed muscle cells. Further study is necessary to investigate the biological function(s) of the TLR gene family in horse muscle cells.

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

  • ;;;;;윤형선
    • 대한의생명과학회지
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    • 제16권1호
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    • pp.39-45
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    • 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.

Molecular Signatures in Chicken Lungs Infected with Avian Influenza Viruses

  • Jeong Woong Park;Marc Ndimukaga;Jaeyoung Heo;Ki-Duk Song
    • 한국가금학회지
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    • 제50권4호
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    • pp.193-202
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    • 2023
  • 인플루엔자 A 바이러스(IAVs)는 많은 조류 종의 호흡 기관에 감염되며 사람을 비롯한 다른 동물로 전파될 수 있는 포장된 음극성 역전사 RNA 바이러스이다. 이 연구에서는 이전 연구의 마이크로어레이 데이터를 다시 분석하여 닭에서 공통 및 특이하게 발현되는 유전자(DEG) 및 그들의 생물학적 활동을 식별하였다. 고병원성(HPAIV) 및 저병원성(LPAIV) 인플루엔자 A 바이러스 감염된 닭 세포에서 각각 760개와 405개의 DEG가 발굴되다. HPAIV 및 LPAIV는 각각 670개와 315개의 DEG를 가지고 있으며, 이 중 90개의DEG가 두 바이러스에서 공유된다. HPAIV 감염으로 인해DEG의 기능 주석에 따르면 세포 주기의 기본적인 생물학적 기능과 연관된 다양한 유전자가 발굴되었다. 대상 유전자중에서 CDC Like Kinase 3(CLK3), Nucleic Acid Binding Protein 1(NABP1), Interferon-Inducible Protein 6(IFI6), PIN2 (TERF1) Interacting Telomerase Inhibitor 1(PINX1), 그리고Cellular Communication Network Factor 4(WISP1)의 발현은 polyinosinic:polycytidylic acid(PIC)로 처리된 DF-1 세포에서 변화되었다. 이것은 toll-like receptor 3(TLR3) 리간드인 TLR3 신호에 의해 이러한 유전자의 전사가 조절될 수 있음을 시사하며, 닭에서 AIV의 병리 생리학에 대한 더 나은 이해를 얻기 위해서는 AIV 감염 과정 중에 호스트 반응을 조절할 수 있는 메커니즘을 구명하는 데 더 많은 연구에 초점을 맞추는 것이 필요하다고 사료된다. 이러한 메커니즘에 대한 이해는 신규 치료 전략 개발에 활용될 수 있다.

Regulation of Chicken FABP4 Transcription by Toll-Like Receptor 3 Activation in DF-1 Cells

  • Jae Rung So;Sujung Kim;Ki-Duk Song
    • 한국가금학회지
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    • 제50권4호
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    • pp.283-291
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    • 2023
  • 지방산 결합 단백질(FABP)은 LCFA 수송, 지질 합성, 저장을 용이하게 하고, 염증을 포함한 다양한 경로에 영향을 미치는 신호 분자로 작용한다. 특히 FABP4는 혈관 및 심장관련 질환과 관련이 있으며, 대식세포 매개 염증 반응에서 역할을 한다. 이전의 연구들은 FABP4를 지방 생성을 위한 대표적인 바이오 마커일 뿐만 아니라, 면역 반응과도 상관관계가 있는 것으로 확인하였다. 본 연구는 톨-유사 수용체 3(TLR3) 활성화에 의한 닭 FABP4(chFABP4) 유전자의조절을 조사하고 chFABP4 전사 조절에 관여하는 신호 경로를 결정하는 것을 목표로 한다. 우리는 TLR3 자극 DF-1 세포에서 chFABP4의 전사 조절을 분석하였다. 결과는 TLR3 리간드인 폴리이노신-폴리시티딜산(PIC)으로 자극 시 chFABP4가 상향 조절되었음을 보여주었다. 특히 chFABP4 전사는 NF-κB 신호 경로에서 독립적으로 조절되었다. p38 억제에서 상향 조절되어 p38 신호 경로가 TLR3 활성화 DF-1 세포 내에서 chFABP4 전사를 억제할 수 있음을 보여주었다. 이와는 대조적으로, JNK 신호 경로 억제에서는 chFABP4 발현이 하향 조절되었으며, 이는 대식세포의 연구 결과와 일치하며, TLR3 활성화에 반응하여 DF-1 세포에서 chFABP4 전사를 위한 JNK 신호 전달 경로의 긍정적인 조절을 시사한다. MEK 경로 억제는 NF-κB 신호 전달과 유사한 조절을 초래하였다. 이러한 결과는 각 MAPK가 TLR3 활성화에 반응하여 DF-1 세포에서 chFABP4의 전사 조절에 차별적으로 기여함을 시사한다.

Pneumococcal Δpep27 Immunization Attenuates TLRs and NLRP3 Expression and Relieves Murine Ovalbumin-Induced Allergic Rhinitis

  • Yu, Jae Ik;Kim, Ji-Hoon;Nam, Ki-El;Lee, Wonsik;Rhee, Dong-Kwon
    • Journal of Microbiology and Biotechnology
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    • 제32권6호
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    • pp.709-717
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    • 2022
  • Allergic rhinitis (AR), one of the most common inflammatory diseases, is caused by immunoglobulin E (IgE)-mediated reactions against inhaled allergens. AR involves mucosal inflammation driven by type 2 helper T (Th2) cells. Previously, it was shown that the Streptococcus pneumoniae pep27 mutant (Δpep27) could prevent and treat allergic asthma by reducing Th2 responses. However, the underlying mechanism of Δpep27 immunization in AR remains undetermined. Here, we investigated the role of Δpep27 immunization in the development and progression of AR and elucidated potential mechanisms. In an ovalbumin (OVA)-induced AR mice model, Δpep27 alleviated allergic symptoms (frequency of sneezing and rubbing) and reduced TLR2 and TLR4 expression, Th2 cytokines, and eosinophil infiltration in the nasal mucosa. Mechanistically, Δpep27 reduced the activation of the NLRP3 inflammasome in the nasal mucosa by down-regulating the Toll-like receptor signaling pathway. In conclusion, Δpep27 seems to alleviate TLR signaling and NLRP3 inflammasome activation to subsequently prevent AR.

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
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    • 제21권5호
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    • pp.531-546
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    • 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.