• 제목/요약/키워드: Cyclooxygenase pathways

검색결과 117건 처리시간 0.026초

20(S)-Protopanaxatriol inhibits release of inflammatory mediators in immunoglobulin E-mediated mast cell activation

  • Kim, Dae Yong;Ro, Jai Youl;Lee, Chang Ho
    • Journal of Ginseng Research
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    • 제39권3호
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    • pp.189-198
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    • 2015
  • Background: Antiallergic effect of 20(S)-protopanaxatriol (PPT), an intestinal metabolite of ginseng saponins, was investigated in guinea pig lung mast cells and mouse bone marrow-derived mast cells activated by a specific antigen/antibody reaction. Methods: Increasing concentrations of PPT were pretreated 5 min prior to antigen stimulation, and various inflammatory mediator releases and their relevant cellular signaling events were measured in those cells. Results: PPT dose-dependently reduced the release of histamine and leukotrienes in both types of mast cells. Especially, in activated bone marrow-derived mast cells, PPT inhibited the expression of Syk protein, cytokine mRNA, cyclooxygenase-1/2, and phospholipase $A_2$ ($PLA_2$), as well as the activities of various protein kinase C isoforms, mitogen-activated protein kinases, $PLA_2$, and transcription factors (nuclear factor-${\kappa}B$ and activator protein-1). Conclusion: PPT reduces the release of inflammatory mediators via inhibiting multiple cellular signaling pathways comprising the $Ca^{2+}$ influx, protein kinase C, and $PLA_2$, which are propagated by Syk activation upon allergic stimulation of mast cells.

Targeted chiral lipidomics analysis of bioactive eicosanoid lipids in cellular systems

  • Lee, Seon-Hwa;Blair, Ian A.
    • BMB Reports
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    • 제42권7호
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    • pp.401-410
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    • 2009
  • We have developed a targeted lipidomics approach that makes it possible to directly analyze chiral eicosanoid lipids generated in cellular systems. The eicosanoids, including prostaglandins (PGs), thromboxanes (TXs), leukotrienes (LTs) and alcohols (HETEs), have been implicated as potent lipid mediators of various biological processes. Enzymatic formations of eicosanoids are regioselective and enantioselective, whereas reactive oxygen species (ROS)-mediated formation proceeds with no stereo-selectivity. To distinguish between enzymatic and non-enzymatic pathways of eicosanoid formation, it is necessary to resolve enantiomeric forms as well as regioisomers. High sensitivity is also required to analyze the eicosanoid lipids that are usually present as trace amounts (pM level) in biological fluids. A discovery of liquid chromatography-electron capture atmospheric pressure chemical ionization/mass spectrometry (LC-ECAPCI/MS) allows us to couple normal phase chiral chromatography without loss of sensitivity. Analytical specificity was obtained by the use of collision-induced dissociation (CID) and tandem MS (MS/MS). With combination of stable isotope dilution methodology, complex mixtures of regioisomeric and enantiomeric eicosanoids have been resolved and quantified in biological samples with high sensitivity and specificity. Targeted chiral lipidomics profiles of bioactive eicosanoid lipids obtained from various cell systems and their biological implications have been discussed.

Autocrine prostaglandin E2 signaling promotes promonocytic leukemia cell survival via COX-2 expression and MAPK pathway

  • Shehzad, Adeeb;Lee, Jaetae;Lee, Young Sup
    • BMB Reports
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    • 제48권2호
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    • pp.109-114
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    • 2015
  • The COX-2/$PGE_2$ pathway has been implicated in the occurrence and progression of cancer. The underlying mechanisms facilitating the production of COX-2 and its mediator, $PGE_2$, in cancer survival remain unknown. Herein, we investigated $PGE_2$-induced COX-2 expression and signaling in HL-60 cells following menadione treatment. Treatment with $PGE_2$ activated anti-apoptotic proteins such as Bcl-2 and Bcl-xL while reducing pro-apoptotic proteins, thereby enhancing cell survival. $PGE_2$ not only induced COX-2 expression, but also prevented casapse-3, PARP, and lamin B cleavage. Silencing and inhibition of COX-2 with siRNA transfection or treatment with indomethacin led to a pronounced reduction of the extracellular levels of $PGE_2$, and restored the menadione- induced cell death. In addition, pretreatment of cells with the MEK inhibitor PD98059 and the PKA inhibitor H89 abrogated the $PGE_2$-induced expression of COX-2, suggesting involvement of the MAPK and PKA pathways. These results demonstrate that $PGE_2$ signaling acts in an autocrine manner, and specific inhibition of $PGE_2$ will provide a novel approach for the treatment of leukemia.

금은화(金銀花)와 황금(黃芩)이 배오(配伍)된 처방제(處方劑)의 항염증(抗炎症) 효과(效果) 연구(硏究) (Study on the Anti-inflammatory Effects of the Remedy Prescripted with Lonicerae Flos and Scutellariae Radix in U937 cells)

  • 이용숙;장선일
    • 대한한의학방제학회지
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    • 제18권1호
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    • pp.121-132
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    • 2010
  • Inflammatory reaction is characterized by over-production of inflammatory mediators due to an up-regulation of inflammatory pathways, which produce pro-inflammatory mediators, such as interleukin-1beta (IL-$1{\beta}$), IL-6, tumour necrosis factor alpha (TNF-$\alpha$), prostaglantin $E_2$ ($PGE_2$), and nitric oxide (NO) in U937 cells. We investigate the anti-inflammatory effects of water extracts from Lonicerae Flos and Scutellariae Radix in lipopolysaccharide (LPS)-stimulated U937 cells. Each extract suppressed the production of inflammatory mediators (NO, IL-$1{\beta}$, TNF-$\alpha$, and $PGE_2$) and the expression of inducible NO synthase and cyclooxygenase-2 in LPS- stimulated U937 cells in a dose-dependent manner. These suppressive effects were synergistically increased by their combination. Their combination extract also inhibited NF-${\kappa}B$-DNA complex of NF-${\kappa}B$ binding activity and translocation of NF-${\kappa}B$ from cytosol to nucleus. These results suggest that the combination of water-extractable components of Lonicerae Flos and Scutellariae Radix may be useful for therapeutic drugs against inflammatory immune diseases, probably by suppressing the production of inflammatory mediators.

Silencing of COX-2 by RNAi Modulates Epithelial-Mesenchymal Transition in Breast Cancer Cells Partially Dependent on the PGE2 Cascade

  • Cao, Juan;Yang, Xiao;Li, Wen-Tong;Zhao, Chun-Ling;Lv, Shi-Jun
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권22호
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    • pp.9967-9972
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    • 2014
  • In order to prove whether downregulation of COX-2 (Cyclooxygenase-2) could modulate the epithelial-mesenchymal transition (EMT) of breast cancer, celecoxib and siRNA were respectively used to inhibit COX-2 function and expression in MDA-MB-231 cells. The EMT reversal effect in the RNAi treated group was better than that of the celecoxib group while there were no obvious differences in the medium $PGE_2$ levels between the two groups. The results show that COX-2 pathways may contribute considerably to EMT of breast cancer cells, partially dependent on the PGE2 cascade. Akt2, ZEB2 and Snail were measured to clarify the underlying mechanisms of COX-2 on EMT; COX-2 may modulate EMT of breast cancer by regulating these factors. This finding may be helpful to elucidate the mechanisms of selective COX-2 inhibitor action in EMT modulation in breast cancer.

이묘산(二妙散)의 항(抗)류마티즘 효능(效能)에 대한 연구(硏究) (Anti-rheumatiod Arthritis Effects of I-Myo-San Water Extract)

  • 임창경;윤용갑
    • 대한한의학방제학회지
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    • 제17권1호
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    • pp.99-111
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    • 2009
  • Rheumatoid arthritis is characterized by focal loss of cartilage due to an up-regulation of inflammatory pathways, which produce pro-inflammatory mediators, such as interleukin-1(IL-1), tumour necrosis factor alpha($TNF-\alpha$), prostaglantin, and nitric oxide(NO). We investigated the anti-arthritic effects of water extracts from Pellodendri cortex and Atractylodis rhizoma in vitro and in vivo. Each extract suppressed the production of inflammatory mediators(NO, $IL-1\beta$, $TNF-\alpha$, and prostaglandin $E_2$) and the expression of inducible NO synthase and cyclooxygenase-2 in lipopolysaccharide-stimulated macrophages in a dose-dependent manner. These suppressive effects were synergistically increased by their combination. The same results were also observed in the rat osteoblast sarcoma cell line ROS17/2.8 stimulated with $IL-1\beta$, $IFN-\gamma,$ and $TNF-\alpha$. Moreover, the combination of these water extracts significantly suppressed collagen-induced mouse arthritis. These results suggest that the combination of water-extractable components of Pellodendri cortex and Atractylodis rhizoma may be useful for therapeutic drugs against rheumatoid arthritis, probably by suppressing the production of inflammatory mediators.

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Anti-platelet Effects of Dimethyl Sulfoxide via Down-regulation of COX-1 and $TXA_2$ Synthase Activity in Rat Platelets

  • Ro, Ju-Ye;Lee, Hui-Jin;Ryu, Jin-Hyeob;Park, Hwa-Jin;Cho, Hyun-Jeong
    • 대한의생명과학회지
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    • 제20권2호
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    • pp.70-76
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    • 2014
  • In this study, we investigated the effect of DMSO, a highly dipolar organic liquid, in collagen ($5{\mu}g/ml$)-stimulated platelet aggregation. DMSO inhibited platelet aggregation at 0.5% by inhibiting production of thromboxane $A_2$ ($TXA_2$) which was associated with blocking cyclooxygenase (COX)-1 activity and $TXA_2$ synthase. In addition, DMSO significantly increased the formation of cyclic adenosine monophosphate (cAMP) from adenosine triphosphate (ATP) and cyclic guanosine monophosphate (cGMP) from guanosine triphosphate (GTP). On the other hand, DMSO (0.1~0.5% concentration) did not affect the LDH release which indicates the cytotoxicity. Based on these results, DMSO has anti-platelet effect by regulation of several platelet signaling pathways, therefore we suggest that DMSO could be a novel strategy on many thrombotic disorders.

Effects of Acupuncture at SP6 on Reflux Esophagitis in Rats

  • Lee, Yun Kyu;Rho, Sung Soo;Kim, Jae Soo
    • Journal of Acupuncture Research
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    • 제32권3호
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    • pp.83-93
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    • 2015
  • Objectives : The purpose of this study was to evaluate whether acupuncture at $SP_6$ attenuates esophageal inflammation on refluxed-induced esophagitis. Methods : Acupuncture at $SP_6$ was stimulated by acupuncture torsion technique for 30 seconds four times every hour after an operation induced reflux esophagitis(RE), and its effects were assessed in comparison with RE rats without acupuncture, and normal rats. Results : $SP_6$ acupuncture stimulation markedly ameliorated mucosal damage in the histological evaluation. Reflux-induced esophagitis rats exhibited the down-regulation of antioxidant-related protein expression levels such as heme oxygenase-1(HO-1) in the esophagitis; however, the associated levels with $SP_6$ acupuncture stimulation were significantly higher than those in RE rats without acupuncture stimulation. Moreover, $SP_6$ acupuncture stimulation significantly reduced the expression of inflammatory proteins through mitogen-activated protein kinase(MAPK)-related signaling pathways. The increased protein expressions of inflammatory mediators, cyclooxygenase-2(COX-2) and inducible nitric oxide synthase(iNOS), by nuclear factor-kappa B(NF-kB) activation were significantly suppressed through $SP_6$ acupuncture stimulation. Conclusions : Our findings support the therapeutic evidence for $SP_6$ acupuncture stimulation alleviating the development of esophagitis via regulating inflammation through the activation of the antioxidant pathway.

금은화(金銀花)의 항(抗)류마티즘 효능(效能)에 대한 연구(硏究) (Effects of FLOS LONICERAE Water Extract On Anti-Rheumatiod Arthritis)

  • 김희수;기호필;이준서;윤용갑
    • 대한한의학방제학회지
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    • 제18권2호
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    • pp.183-199
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    • 2010
  • Rheumatoid arthritis is characterized by the focal loss of cartilage due to an up-regulation of inflammatory pathways, which produce inflammatory mediators, such as interleukin-1beta(IL-$1{\beta}$), IL-6, tumour necrosis factor alpha(TNF-$\alpha$), prostaglandin, and nitric oxide(NO). We investigated the anti-arthritic effects of water extract from FLOS LONICERAE(FLWE) in vitro and in vivo. Extract inhibited the production of inflammatory mediators(NO, IL-$1{\beta}$, TNF-$\alpha$, and prostaglandin $E_2$) and the expression of inducible NO synthase(iNOS) and cyclooxygenase-2(COX-2) in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages in a dose-dependent manner. FLWE also inhibited TNF-$\alpha$, IL-$1{\beta}$, IL-6, and $PGE_2$ production as well as COX activity in collagen-induced mouse arthritis. Moreover, FLWE significantly suppressed collagen-induced mouse arthritis. These results suggest that FLOS LONICERAE may be useful for therapy against inflammatory immune diseases and rheumatoid arthritis, probably by suppressing the production of inflammatory mediators.

金銀花와 黃芩이 配伍된 處方劑의 抗炎症 效果 硏究 (Study on the Anti-inflammatory Effects of the Remedy Prescripted with Lonicera japonica and Scutellaria baicalensis Radix in U937 cells)

  • 이용숙;정명;임규상;윤용갑
    • 한방안이비인후피부과학회지
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    • 제28권3호
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    • pp.1-13
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    • 2015
  • Objective : This study investigated the inflammatory reaction is characterized by over production of inflammatory mediators due to an up-regulation of inflammatory pathways.Methods : We investigated the anti-inflammatory effects of water extracts fromLonicera japonicaandScutellaria baicalensisin lipopolysaccharide (LPS)-stimulated U937 cells. Each extract suppressed the production of inflammatory mediators (NO, IL-1${\beta}$, TNF-${\beta}$, and PGE2) and the expression of inducible NO synthase and cyclooxygenase-2 in LPS- stimulated U937 cells in a dose-dependent manner.Results : These suggest that the suppression effects were synergistically increased by their combination. Their combination extract also inhibited NF-${\kappa}B$-DNA complex of NF-${\kappa}B$ binding activity and translocation of NF-${\kappa}B$ from cytosol to nucleus.Conclusions : Our study suggest that the combination of water-extractable components ofL. japonicaandS. baicalensismay be useful for therapeutic drugs against inflammatory immune diseases, probably by suppressing the production of inflammatory mediators.