• Title/Summary/Keyword: Toll-like receptor 2

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The role of CD14 and Toll-like receptors on the release of MMP-B in the LPS recognition pathway (지질 다당질 인지경로에서 기질금속단백분해효소-8 분비에 대한 CD14와 Toll-like receptors의 역할 연구)

  • Yang, Seung-Min;Kim, Tae-li;Seol, Yang-Jo;Lee, Yang-Moo;Ku, Young;Chung, Chong-Pyoung;Han, Soo-Boo;Rhyu, In-Chul
    • Journal of Periodontal and Implant Science
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    • v.36 no.3
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    • pp.579-590
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    • 2006
  • 1. 연구배경 교원질 분해작용을 하는 호중구의 세포질 효소인 기질금속단백분해효소-8은 치주질환, 류마티스 관절염, 그리고 궤양결장염과 같은 염증성 질환에서 농도가 증가한다고 알려져 있다. 최근에는 A. actinomycetemcomitans의 leukotoxin이 사람호중구에서 기질금속단백분해효소-8의 분비를 유도하는 것이 보고되었다. 이 연구의 목적은 선천면역 체계에서 세포표면 항원무리14, Toll-like 수용기, 그리고 $NF-{\kappa}$ B경로를 통하여 A. actinomycetemcomitans의 지질다당질로 유도된 기질금속단백분해효소-8의 분비 여부와 세포기전을 알아보고자 하였다. 2. 연구재료 및 방법 건강한 개인 제공자(남자 13명, 여자 3명)로부터 얻은 개개인의 20ml 말초혈액을 제조사의 지침에 따라 호중구를 추출한 후 항세포표면 항원무리14와 함께 $4^{\circ}C$에서 30분간 전배양 한 후, $37^{\circ}C$에서 9시간 동안 배양시켰다. 추출한 호중구에 Toll-like 수용기 억제제 또는 $NF-{\kappa}$ B억제제인 TPCK를 첨가한 후 $37^{\circ}C$에서 1시간 동안 전배양하고 $37^{\circ}C$에서 9시간 동안 배양시켰다. 호중구에 세포뼈대 억제제인 cholchicine, nocodazole, demecolcine, 그리고 cytochalasin B를 A. actinomycetemcomitans의 지질다당질과 함께 $37^{\circ}C$에서 9시간 동안 배양시켰다. 기질금속단백분해효소-8 분비량은 효소면역측정법을 통해 결정하였다. 통계처리는 일원배치 분산분석법을 이용하였다(p<0.05). 3. 결과 A. actinomycetemcomitans 지질다당질은 기질금속단백분해효소-8의 분비를 증가시켰다. 기질금속단백분해효소-8의 분비는 항세포표면 항원무리14에 의해서 억제되었지만, 항 Toll-like 수용기2, 항 Toll-like 수용기4 항체는 억제시키지 못했다. $NF-{\kappa}$ B 억제제는 A. actinomycetemcomitans의 지질다당질로 유도된 $NF-{\kappa}$ B 결합 활성도와 기질금속단백분해효소-8 분비를 억제하였다. 미세섬유 중합반응 억제제는 A. actinomycetemcomitans의 지질다당질로 유도된 기질금속단백분해효소-8의 분비를 억제시켰으나, 미세관 중합반응억제제는 억제시키지 못했다. 4. 결론 위의 연구결과를 종합하여 볼 때, 기질금속단백분해효소-8은 A. actinomycetemcomitans의 지질다당질로 유도되며, 세포표면 항원무리-$NF-{\kappa}$ B 경로를 통하여 분비되고, 이 분비 과정은 미세섬유 계통이 관여하는 것으로 보인다.

Suppression of the Expression of Cyclooxygenase-2 Induced by Toll-like Receptor 2, 3, and 4 Agonists by 6-Shogaol (6-Shogaol의 Toll-like receptor 2, 3, 4 agonists에 의해서 유도된 cyclooxygenase-2 발현 억제)

  • Kim, Jeom-Ji;An, Sang-Il;Lee, Jeon-Su;Yun, Sae-Mi;Lee, Mi-Yeong;Yun, Hyeong-Seon
    • Korean Journal of Food Science and Technology
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    • v.40 no.3
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    • pp.332-336
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    • 2008
  • Ginger is widely used as a traditional herbal medicine. Both ginger and its extracts have been used to treat many chronic inflammatory conditions via the inhibition of nuclear factor-kappa B (NF-${\kappa}B$) activation, which results in the suppression of cyclooxygenase-2 (COX-2) expression. However, the mechanisms as to how ginger extracts mediate their health effects are largely unknown. Toll-like receptors (TLRs) trigger anti-microbial innate immune responses, recognizing conserved microbial structural molecules that are known as pathogen-associated molecular patterns. All TLR signaling pathways culminate in the activation of NF-${\kappa}B$. The activation of NF- ${\kappa}B$ leads to the induction of inflammatory gene products, including cytokines and COX-2. This study reports the biochemical evidence that 6-shogaol, an active compound in ginger, inhibits NF-${\kappa}B$ activation and COX-2 expression induced by TLR2, TLR3, and TLR4 agonists. Furthermore, 6-shogaol inhibited NF-${\kappa}B$ activation induced by the following downstream signaling components of the TLRs: MyD88, $IKK{\beta}$, and p65. These results imply that ginger can modulate immune responses that could potentially modify the risk of many chronic inflammatory diseases.

Hepatoprotective effect of ultrasonicated ginseng berry extract on a rat mild bile duct ligation model

  • Nam, Yoonjin;Ko, Sung Kwon;Sohn, Uy Dong
    • Journal of Ginseng Research
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    • v.43 no.4
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    • pp.606-617
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    • 2019
  • Background: The Panax ginseng berry extract (GBE) is well known to have an antidiabetic effect. The aim of this study is to evaluate and investigate the protective effect of ultrasonication-processed P. ginseng berry extract (UGBE) compared with GBE on liver fibrosis induced by mild bile duct ligation (MBDL) model in rats. After ultrasonication process, the composition ratio of ginsenoside in GBE was changed. The component ratio of ginsenosides Rh1, Rh4, Rg2, Rg3, Rk1, Rk3, and F4 in the extract was elevated. Methods: In this study, the protective effect of the newly developed UGBE was evaluated on hepatotoxicity and neuronal damage in MBDL model. Silymarin (150 mg/kg) was used for positive control. UGBE (100 mg/kg, 250 mg/kg, 500 mg/kg), GBE (250 mg/kg), and silymarin (150 mg/kg) were orally administered for 6 weeks after MBDL surgery. Results: The MBDL surgery induced severe hepatotoxicity that leads to liver inflammation in rats. Also, the serum ammonia level was increased by MBDL surgery. However, the liver dysfunction of MBDL surgery-operated rats was attenuated by UGBE treatment via myeloid differentiation factor 88-dependent Toll-like receptor 4 signaling pathways. Conclusion: UGBE has a protective effect on liver fibrosis induced by MBDL in rats through inhibition of the TLR4 signaling pathway in liver.

Role of microglial activation on neuronal excitability in rat substantia gelatinosa

  • Park, Areum;Chun, Sang Woo
    • International Journal of Oral Biology
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    • v.45 no.4
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    • pp.225-231
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    • 2020
  • Glial cells, including astrocytes and microglia, interact closely with neurons and modulate pain transmission, particularly under pathological conditions. In this study, we examined the excitability of substantia gelatinosa (SG) neurons of the spinal dorsal horn using a patch clamp recording to investigate the roles of microglial activation in the nociceptive processes of rats. We used xanthine/xanthine oxidase (X/XO), a generator of superoxide anion (O2·-), to induce a pathological pain condition. X/XO treatment induced an inward current and membrane depolarization. The inward current was significantly inhibited by minocycline, a microglial inhibitor, and fluorocitrate, an astrocyte inhibitor. To examine whether toll-like receptor 4 (TLR4) in microglia was involved in the inward current, we used lipopolysaccharide (LPS), a highly specific TLR4 agonist. The LPS induced inward current, which was decreased by pretreatment with Tak-242, a TLR4-specific inhibitor, and phenyl N-t-butylnitrone, a reactive oxygen species scavenger. The X/XO-induced inward current was also inhibited by pretreatment with Tak-242. These results indicate that the X/XO-induced inward current of SG neurons occurs through activation of TLR4 in microglial cells, suggesting that neuroglial cells modulate the nociceptive process through central sensitization.

NF-${\kappa}$ B Activation and Cyclooxygenase-2 Expression Induced by Toll-Like Receptor Agonists can be Suppressed by Isoliquiritigenin (Isoliquiritigenin의 toll-like receptor agonists에 의해서 유도된 NF-${\kappa}$B 활성화와 cyclooxygenase-2 발현 억제)

  • Park, Se-Jeong;Yang, Seung-Ju;Youn, Hyung-Sun
    • Korean Journal of Food Science and Technology
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    • v.41 no.2
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    • pp.220-224
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    • 2009
  • Toll-like receptors(TLRs) are pattern recognition receptors(PRRs) that 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 COX-2. Licorice (Glycyrrhiza uralensis) has been used for centuries as an herbal medicine. Isoliquiritigenin(ILG), a simple chalcone-type flavonoid, is an active component present in licorice and has been used to treat many chronic diseases. However, the mechanism as to how ILG mediates health effects is still largely unknown. In the present report, we present biochemical evidence that ILG inhibits the NF-${\kappa}$B activation induced by TLR agonists and the overexpression of downstream signaling components of TLRs, MyD88, IKK${\beta}$, and p65. ILG also inhibits TLR agonists-induced COX-2 expression. These results suggest that anti-inflammatory effects of ILG are caused by modulation of the immune responses regulated by TLR signaling pathways.

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

  • Lee, Young Seob;Lee, Dae Young;Kwon, Dong Yeul;Kang, Ok Hwa
    • Korean Journal of Medicinal Crop Science
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    • v.28 no.4
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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.

Molecular Signatures in Chicken Lungs Infected with Avian Influenza Viruses

  • Jeong Woong Park;Marc Ndimukaga;Jaeyoung Heo;Ki-Duk Song
    • Korean Journal of Poultry Science
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    • v.50 no.4
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    • pp.193-202
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    • 2023
  • Influenza IAVs are encapsulated negative-strand RNA viruses that infect many bird species' respiratory systems and can spread to other animals, including humans. This work reanalyzed previous microarray datasets to identify common and specific differentially expressed genes (DEGs) in chickens, as well as their biological activities. There were 760 and 405 DEGs detected in HPAIV and LPAIV-infected chicken cells, respectively. HPAIV and LPAIV have 670 and 315 DEGs, respectively, with both viruses sharing 90 DEGs. Because of HPAIV infection, numerous genes were implicated in a fundamental biological function of the cell cycle, according to the functional annotation of DEGs. Of the targeted genes, expressions of CDC Like Kinase 3 (CLK3), Nucleic Acid Binding Protein 1 (NABP1), Interferon-Inducible Protein 6 (IFI6), PIN2 (TERF1) Interacting Telomerase Inhibitor 1 (PINX1), and Cellular Communication Network Factor 4 (WISP1) were altered in DF-1 cells treated with polyinosinic:polycytidylic acid (PIC), a toll-like receptor 3 (TLR3) ligand, suggesting that transcription of these genes be controlled by TLR3 signaling. To gain a better understanding of the pathophysiology of AIVs in chickens, it is crucial to focus more research on unraveling the mechanisms through which AIV infections may manipulate host responses during the infection process. Insights into these mechanisms could facilitate the development of novel therapeutic strategies.

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
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    • v.21 no.3
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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.

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
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    • v.33 no.6
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    • pp.463-470
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    • 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.

Suppression of the Toll-like receptors 3 mediated pro-inflammatory gene expressions by progenitor cell differentiation and proliferation factor in chicken DF-1 cells

  • Hwang, Eunmi;Kim, Hyungkuen;Truong, Anh Duc;Kim, Sung-Jo;Song, Ki-Duk
    • Journal of Animal Science and Technology
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    • v.64 no.1
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    • pp.123-134
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    • 2022
  • Toll-like receptors (TLRs), as a part of innate immunity, plays an important role in detecting pathogenic molecular patterns (PAMPs) which are structural components or product of pathogens and initiate host defense systems or innate immunity. Precise negative feedback regulations of TLR signaling are important in maintaining homeostasis to prevent tissue damage by uncontrolled inflammation during innate immune responses. In this study, we identified and characterized the function of the pancreatic progenitor cell differentiation and proliferation factor (PPDPF) as a negative regulator for TLR signal-mediated inflammation in chicken. Bioinformatics analysis showed that the structure of chicken PPDPF evolutionarily conserved amino acid sequences with domains, i.e., SH3 binding sites and CDC-like kinase 2 (CLK2) binding sites, suggesting that relevant signaling pathways might contribute to suppression of inflammation. Our results showed that stimulation with polyinosinic:polycytidylic acids (Poly [I:C]), a synthetic agonist for TLR3 signaling, increased the mRNA expression of PPDPF in chicken fibroblasts DF-1 but not in chicken macrophage-like cells HD11. In addition, the expression of pro-inflammatory genes stimulated by Poly(I:C) were reduced in DF-1 cells which overexpress PPDPF. Future studies warrant to reveal the molecular mechanisms responsible for the anti-inflammatory capacity of PPDPF in chicken as well as a potential target for controlling viral resistance.