• BMB Reports
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• 제41권2호
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• pp.139-145
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• 2008

We cloned and pharmacologically characterized the guinea pig cysteinyl leukotriene (CysLT) 2 receptor (gpCysLT2). gpCysLT2 consists of 317 amino acids with 75.3%, 75.2%, 73.3% identity to those of humans, mice and rats, respectively. The gpCysLT2 gene is highly expressed in the lung, moderately in eosinophils, skin, spleen, stomach, colon, and modestly in the small intestine. CysLTs accelerated the proliferation of gpCysLT2-expressing HEK293. Leukotriene C4 (LTC4) and Leukotriene D4 (LTD4) enhanced the cell proliferation higher than Bay-u9773, a CysLT2 selective partial agonist and a nonselective antagonist for CysLT receptors. Bay-u9773 did not antagonize the cell proliferation by LTC4 and LTD4. Despite the equipotency of the mitogenic effect among these chemicals, calcium mobilization (CM) levels were variable (LTC4 > LTD4 >> Bay-u9773), and Bay-u9773 antagonized the CM by LTC4. Moreover, the Gi/o inhibitor pertussis toxin perfectly inhibited agonist-induced cell proliferation. These results reveal that cell proliferation via CysLT2 signaling was mediated by Gi/o signaling but independent of calcium mobilization.

• 약학회지
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• 제56권6호
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• pp.347-351
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• 2012

5-Lipoxygenase (5-LO) catalyzes the formation of two major groups of leukotrienes, LTB4 and cysteinyl leukotrienes (CysLT), and it has been implicated as a promising drug target to treat various inflammatory diseases. Since its role in mature osteoclasts (mOCs) had not been reported, we investigated the effect of 5-LO inhibitors on mOCs. We showed that 5-LO inhibitors dose-dependently decreases the number of mOCs. The effects of 5-LO inhibitors were reversible, suggesting that they did not cause any cellular damages in mOCs. We further demonstrated that the suppression of mOCs by 5-LO inhibitors was caused mainly by disruption of the actin ring formation. Similar effects were shown with CysLT receptor (CysLTR)1 antagonist in mOCs. The mRNA expression of CysLTR1 and the production of CysLT were increased in mOCs. These results indicate that CysLTR1 mediates the suppression of mOCs by 5-LO inhibitors. Taken together, this study demonstrated that 5-LO plays important role in mOCs and possibly a novel therapeutic target for bone resorption diseases.

• 통합자연과학논문집
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• 제8권1호
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• pp.13-18
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• 2015

Cysteinyl leukotrienes are inflammatory mediators having important role in pathophysiological conditions such as asthma, allergic rhinitis and have been implicated in a number of inflammatory conditions including cardiovascular and gastrointestinal diseases. Most of the disease regulatory actions of the CysLTs are mediated through CysLT1 receptor. Hence in the present study, homology modeling of CysLT1 was performed because the availability of 3D structure would enhance the development of new drugs for inflammatory diseases. However the templates identified have low sequence identity which increases the complexity of modeling. Hence, homology modeling was performed using single template, multiple templates and also using threading I-TASSER server. The best model was selected based on the validation of the generated models using Ramachandran and ERRAT plot. The model developed could be useful for identifying crucial residues and docking study.

• 통합자연과학논문집
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• 제9권4호
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• pp.228-233
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• 2016

Cysteinyl leukotrienes are inflammatory mediators having important role in pathophysiological conditions such as asthma and allergic rhinitis. CysLT1 receptor mediates most of the disease regulatory actions of the CysLTs and it is been implicated in a number of inflammatory conditions including gastrointestinal and cardiovascular diseases. Hence in the present study, molecular docking of CysLT1 was performed with its potent and orally efficacious antagonist CP-199330 and CP-199331. The aim of this study was to compare the interaction of CP-199330 and CP-199331 with known drugs such as Zafirlukast, Pranlukast and Montelukast which had already showed clinical efficacy in the treatment of asthma. The residues such as TYR83, GLN274, LYS311 and SER313 were found to interact with both the antagonist and the known drugs. Also, we noticed the docking scores and interaction of the antagonists were comparable with the known drugs. Hence these antagonists could serve as better drugs for the treatment of allergy.

• Parasites, Hosts and Diseases
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• 제62권3호
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• pp.270-280
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• 2024

Trichomoniasis is caused by a sexually transmitted flagellate protozoan parasite Trichomonas vaginalis. T. vaginalis-derived secretory products (TvSP) contain lipid mediators such as leukotriene B₄ (LTB₄) and various cysteinyl leukotrienes (CysLTs) which included LTC₄, LTD₄, and LTE₄. However, the signaling mechanisms by which T. vaginalis-induced CysLTs stimulate interleukin (IL)-8 production in human mast cells remain unclear. In this study, we investigated these mechanisms in human mast cells (HMC-1). Stimulation with TvSP resulted in increased intracellular reactive oxygen species (ROS) generation and NADPH oxidase 2 (NOX2) activation compared to unstimulated cells. Pre-treatment with NOX2 inhibitors such as diphenyleneiodonium chloride (DPI) or apocynin significantly reduced ROS production in TvSP-stimulated HMC-1 cells. Additionally, TvSP stimulation increased NOX2 protein expression and the translocation of p47^phox from the cytosol to the membrane. Pretreatment of HMC-1 cells with PI3K or PKC inhibitors reduced TvSP-induced p47^phox translocation and ROS generation. Furthermore, NOX2 inhibitors or NOX2 siRNA prevented CREB phosphorylation and IL-8 gene expression or protein secretion induced by TvSP. Pretreatment with a CysLTR antagonist significantly inhibited TvSP-induced ROS production, CREB phosphorylation, and IL-8 production. These results indicate that CysLT-mediated activation of NOX2 plays a crucial role in ROS-dependent IL-8 production in human mast cells stimulated by T. vaginalis-secreted CysLTs. These findings enhance our understanding of the inflammatory response in trichomoniasis and may inform the development of targeted therapies to mitigate this response.

• 동의생리병리학회지
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• 제26권4호
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• pp.469-474
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• 2012

Fagopyrum esculentum(FE) is an important food crop and medicinal plant that is used to improve diabetes, obesity, hypertension, hypercholesterolemia and constipation in Korea, but the underlying mechanisms involved in its anti-allergic activity are not fully understood. We investigated the effects on the release of inflammatory mediator and proximal signal events in $Fc{\varepsilon}RI$-mediated RBL-2H3 cell activation. FE reduced antigen (DNP-HSA)-induced release of histamine, prostaglandin D2 (PGD2) and cysteinyl Leukotriene (cysLT) in IgE-sensitized RBL-2H3 cells. In addition, it inhibited antigen-induced HDC2 and COX-2 and 5-LO mRNA expression in IgE-sensitized RBL-2H3 cells. FE also suppressed antigen-induced $Fc{\varepsilon}RI{\beta}$ and $Fc{\varepsilon}RI{\gamma}$ subunit mRNA expression in these cells. To identify the mechanisms underpinning the inhibition of release of inflammatory mediators such as histamine and PGD2 and cysLT by FE, we examined the proximal signal events of intracellular FceRI signaling molecules. FE suppressed antigen-induced phosphorylation of Lyn, Syk, LAT, $PLC{\gamma}1$, PI3K, Akt and cPLA2. Collectively, the anti-allergic effects of FE in vitro suggest its possible therapeutic application to inflammatory allergic diseases, in which its inhibition of inflammatory mediator and FceRI-dependent signaling events in mast cells may be hugely beneficial.

• Korean Journal of Acupuncture
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• 제29권3호
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• pp.406-420
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• 2012

Objectives : Scutellaria barbata has been widely used in oriental medicine used for treatment of acute and chronic inflammatory diseases. In this study, to investigate the protective effect of Scutellaria barbata on type I allergic response, we determined whether Scutellaria barbata inhibits early or late allergic responses. Methods : To assess the effect of Scutellaria barbata Pharmacopuncture Extract(SB) in RBL-2H3 cells, we investigated the levels of the markers of degranulation such as ${\beta}$-hexosaminidase and histamine, inflammatory mediator such as IL-4, TNF-${\alpha}$, PGE2 and cysLT, and mRNA expression of cytokines and enzymes. In addition, we determined the levels of intracellular ROS by DCFH-DA assay and the free radical scavenging activity by DPPH method. Results : We found that SB suppressed the release of ${\beta}$-hexosaminidase and histamine and the production of IL-4, TNF-${\alpha}$, PGE2 and cysLT in RBL-2H3 by the antigen stimulation. SB also significantly inhibited the enzyme mRNA expressions, such as HDC2, COX-1, COX-2, 5-LOX and iNOS2, along with reduced cytokine mRNA expressions, such as IL-$1{\beta}$, IL-2, IL-3, IL-4, IL-5, IL-6, IL-13, TNF-${\alpha}$ and GM-CSF in RBL-2H3. In addition, SB suppressed the levels of intracellular ROS. Conclusions : Our results indicate that SB protects against type I allergic response and exert an anti-inflammatory effect through the inhibition of degranulation, inflammatory mediator release and mRNA expression of cytokines and enzymes.

• Tuberculosis and Respiratory Diseases
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• 제46권5호
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• pp.697-708
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• 1999

연구배경 : 기관지 천식에서 기관지 수축 및 호산구 화학 주성 효과를 나타내는 Leukotrienes (LTs)의 역할이 최근 잘 알려져 있으며 이러한 LTs의 작용을 억제하는 치료제에 대한 관심이 대두되고 있다. 저자들은 비마취, 비결박 상태의 기니픽 기관지 천식 모델에서 즉시형 기관지 수축 반응 시 기도저항의 변동을 측정하고, pranlukast 투여가 기도저항, 기관지 조직내 호산구의 침윤 정도, 혈중 $LTC_4$의 농도의 변화에 미치는 영향을 평가하고자 본 연구를 실시하였다. 방 법 : 기니픽 44마리 (치료군 16마리, 대조군 19마리, 정상군 9마리)를 대상으로 하였으며 치료군과 대조군 기니픽에 ovalbumin(OVA)을 감작하고 1주후 OVA을 연무기를 이용하여 흡입시켜 즉시형 기도수축 모델을 만든 뒤 실험 동물용 체적 기록 상자를 이용하여 기도저항을 측정하였다. 정상군은 감작하지 않은 상태에서 기도저항을 측정하였다. 치료군은 pranlukast 10mg/kg/day를, 대조군과 정상군은 생리식염수 1ml/day를 7일간 경구 투여한 후 치료군, 대조군, 정상군 모두 indomethacine 10mg/kg 및 mepyramine 10mg/kg를 복강내 투여한 다음 OVA 분무로 즉시형 기관지 수축반응을 일으켜 기도저항을 측정하였다. 기도저항 측정 후 혈중 $LTC_4$의 농도를 측정하고 한 쪽 폐장을 적출하여 파라핀 포매조직을 만들어 H-E 염색으로 세기관지를 포함하는 400배 현미경 시야내에 존재하는 호산구의 수로써 호산구의 침윤 정도를 확인하였다. 결 과 : 천식 모델로 확인된 기니픽은 치료군 8마리, 대조군 16마리로 57.1%의 발생율을 나타내었고 기관지 천식이 발생되지 않은 기니픽은 모두 본 연구 대상에서 제외시켰다. OVA으로 감작 시키지 않은 정상군의 기도저항의 변동은 기저치의 50% 내외였다. OVA 흡입으로 즉시형 기관지 수축 반응을 나타낸 상태에서 측정한 기도저항은 치료군에서는 흡입 후 3분부터 24분까지 3분 간격으로 측정 했을때 3분, 6분에서 pranlukast 투여 후가 투여 전에 비하여 통계적으로 유의하게 낮았고 24분까지 통계적 유의성은 없었지만 기도저항이 투여전에 비하여 감소된 경향을 나타내었다. 대조군에서는 OVA 흡입후 3분부터 30분까지 생리식염수 투여전파 후에 기도저항의 차이가 없었다. 혈중 $LTC_4$ 농도는 치료군 348.4 pg/ml, 대조군 373.9 pg/ml였으며, 정상군에서는 364.4 pg/ml로 치료군과 대조군(p=0.232), 치료군과 정상군(p=0.501), 사이에 통계적으로 유의한 차이가 발견되지 않았고, 치료군, 대조군 및 정상군의 세 구간의 비교에서도 통계적으로 의미 있는 차이가 없었다(p=0.456). 기관지 조직내 호산구의 침윤은 400배 현미경 시야당 치료군, 대조군, 정상군 각각 7.06, 19.2, 4.50개로 치료군, 대조군, 정상군 사이의 분산분석에서는 세군간에 의미 있는 차이가 있었고(p=0.008) 치료군이 대조군에 비하여 통계적으로 의미 있는 감소를 나타내었다(p=0.001). 곁 론 : OVA으로 감작된 기니픽 천식 모델에서 즉시형 기관지 수축 반응 시 cys-LTs 수용체 억제제인 pranlukast 경구 투여는 대조군과 비교하여 기도저항의 감소 및 기관지, 폐 조직 내 호산구 침윤의 감소를 나타내어 기관지 수축 억제 효과가 있음을 알 수 있었다. 혈중 $LTC_4$의 농도는 대조군과 차이가 없음이 관찰되어 전신의 순환 cys-LTs에는 영향을 미치지 않음을 알 수 있었다. 이와 같은 기니픽에 대한 결과를 바탕으로 향후 기관지 천식 환자에 대한 pranlukast의 효과에 관하여 더 많은 연구가 필요할 것으로 사료된다.

• Mass Spectrometry Letters
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• 제11권4호
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• pp.71-76
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• 2020

While montelukast (ML), a cysteinyl-leukotriene type 1 receptor (CysLT1) antagonist is widely used to treat symptoms of rhinitis or asthma, its formulations are mainly limited to solid preparation due to its instability. Recently, there have been attempts to develop various ML dosage forms, and this situation increases the demand of sensitive and creditable methods to determine ML in various samples such as plasma. Thus, here, a simple and efficient method to determine ML in rat plasma using liquid-liquid extraction (LLE) and multiple reaction monitoring was presented. The mixture of DCM:EtOAc (25:75, v/v), the optimized extract solvent for LLE was found to be effective to extract ML without hydrophilic salts and proteins from the sample with limited volume. Also, the use of zafirlukast, instead of expensive ML-d6, as the internal standard makes the present method economical. The developed method was successfully validated in terms of selectivity, matrix effects (-14.8--6.9%), linearity (r230.998 within 0.5-500 ng/mL), sensitivity (the limit of detection and the lower limit of quantitation, ≤0.5 ng/mL), accuracy (88.4-100.6%), precision (3.0-13.3%), and recovery (80.8-86.3%) by following the FDA guidelines. Finally, the applicability of the validated method to pharmacokinetics (PK) studies was confirmed by the successful determination of PK parameters through it following oral administration of Singulair® granule in rats. Therefore, the present method can contribute to the development of new ML formulations through its performance to determine ML in rat plasma efficiently and sensitively.