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OBJECTIVE We have recently reported that cysteinyl leukotriene (CysLT) signaling plays an important role in microglial interleukin (IL)-1β secretion and subsequent neurotoxicity. The present study aimed to examine microglial morphological changes and the upstream molecular underlying IL-1βproduction in CysLT receptor agonist leukotriene D4 (LTD4)-treated BV2 microglia in vitro. METHODS Twenty-four hours after murine microglial BV2 cells were stimulated with LTD4 (1-100 nmol·L- 1), the cell proliferation and morphology were observed. The expression level of cysteinyl aspartate-specific protease 1 (CASP1) protein was measured by Western blotin BV2 cells. In addition, BV2 cells were pretreated with or without CysLT1 receptor antagonist montelukast for 1 h and the effects of monte-lukaston LTD4-stimulated microglial activation and CASP1 expression were evaluated. RESULTS The number of BV2 cells had an increasing tendency after 24 h treatment with LTD4, but no significant differences were observed between the control and LTD4-treated cells (P>0.05). Under basal and resting conditions, BV2 microglial cells displayed a ramified morphology. However, LTD4 at 100 nmool · L- 1 drove microglial morphological changes from a ramified towards an amoeboid shape. The expression of CASP1 protein was significantly upregulated in 100 nmool·L-1 LTD4-treated BV2 microglia (P<0.01). Furthermore, pretreatment with CysLT1 receptor antagonist montelukast prevented cell morphological changes and suppressed the increased CASP1 expression in LTD4-treated BV2 cells (P<0.05). CONCLUSION CysLT receptor agonist LTD4 induces morphological changes and CASP1 expressionin BV2 microglia, which can be inhibited by CysLT1 antagonist. These results suggest the involvement of CysLT signaling in microglial morphological changes and CASP1 expression.
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Objective o investigate the prophylactic and therapeutic effects of montelukast,a cysteinyl leukotriene receptor-1 (CysLT1R) antagonist,on the delayed neuropsychological sequelae (DNS) in rat model of carbon monoxide (CO) poisoning and to explore the possible underlying mechanism.Methods A total of 90 rats were acclimated for one week prior to screening rat by Morris water maze test.Ten rats were randomly assigned to control group (Con group),and the remaining 80 rats were subjected to modified method of intraperitoneal injection of CO gas to establish animal model of acute CO poisoning,Thereafter,the survival rats randomized into CO poisoning group (Mod group),low-dose montelukast group (ML group),medium-dose montelukast group (MM group),high-dose montelukast group (MH group) (n =10 each).Montelukast was accordingly administered via intragastric tube at different intervals (30 min,4 h and 12 h) after CO poisoning,and then montelukast was administered every 12 hours for 7 consecutive days.The rats of control group and Mod group received equal volume of normal saline instead at given intervals.Twenty-one days after CO exposure,the average escape latency was measured by Morris water maze test to screen DNS rats followed by H-E staining to observe the pathological changes of cortex and hippocampal CA1 region and TUNEL was used to assess the apoptosis of neurons in cortex and hippocampal CA1 region after rats sacrificed.Results All CO-exposed rats exhibited cognition function lowered,and the escape latency (seconds) in Mod group (43.3 ± 15.5),ML group (31.5 ± 13.2) and MH groups (30.1 ± 12.2) was significantly prolonged compared with Con group (12.1 ± 3.0) (P ＜ 0.05),whereas the difference between MM group (15.0 ± 6.6) and Con group was statistically insignificant (P ＞ 0.05).Compared with Mod group,the escape latency in montelukast treatment groups was shortened,whereas the significant difference in escape latency only found between Mod group and MM group (P ＜ 0.05).Except for Con group,DNS was evident in CO-exposed groups,and the numbers of DNS rats in Mod,ML,MM and MH groups were 8,5,1,4,respectively,which made statistically significant differences to Con group (P ＜ 0.05) except MM group.The DNS incidence in MM group was lower than that in Mod group (P ＜ 0.05).Mod group exhibited severe histopathological injury to the brain,with evident apoptosis of neural cells,whereas in the groups with montelukast treatment,histopathological damage to the brain was mitigated and the number of apoptotic neuronal cells was diminished noticeably in MM group.Conclusion Montelukast can ameliorate the cognitive function of rats,decrease the incidence of DNS and reduce the apoptosis of neural cells as well as attenuate neuronal cell injury,thus exerting neuroprotection against DNS in rats with CO poisoning.
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Introductıon Ureteral obstruction is a common pathology and caused kidney fibrosis and dysfunction at late period. In this present, we investigated the antifibrotic and antiinflammatory effects of montelukast which is cysteinyl leukotriene receptor antagonist, on kidney damage after unilateral ureteral obstruction(UUO) in rats. Mateirıals and Methods 32 rats divided four groups. Group 1 was control, group 2 was sham, group 3 was rats with UUO and group 4 was rats with UUO which were given montelukast sodium (oral 10 mg/kg/day). After 14 days, rats were killed and their kidneys were taken and blood analysis was performed. Tubular necrosis, mononuclear cell infiltration and interstitial fibrosis scoring were determined histopathologically in a part of kidneys; nitric oxide(NO), malondialdehyde(MDA) and reduced glutathione(GSH) levels were determined in the other part of kidneys. Urea-creatinine levels were investigated at blood analysis. Statistical analyses were made by the Chi-square test and one-way analysis of variance (ANOVA). Results There was no difference significantly for urea-creatinine levels between groups. Pathologically, there was serious tubular necrosis and fibrosis in group 3 and there was significantly decreasing for tubular necrosis and fibrosis in group 4(p<0.005). Also, there was significantly increasing for NO and MDA levels; decreasing for GSH levels in group 3 compared the other groups(p<0.005). Conclusıon We can say that montelukast prevent kidney damage with antioxidant effect, independently of NO. .
Subject(s)
Female , Humans , Middle Aged , Breast Neoplasms/chemistry , Carcinoma, Ductal, Breast/chemistry , DNA-Binding Proteins/analysis , Epithelial-Mesenchymal Transition , Estrogen Receptor alpha/analysis , Transcription Factors/analysis , Biomarkers, Tumor/analysis , Breast Neoplasms/pathology , Cadherins/analysis , Carcinoma, Ductal, Breast/pathology , Immunohistochemistry , Predictive Value of Tests , Prognosis , Tissue Array Analysis , beta Catenin/analysisABSTRACT
Objective To explore whether TNF-α involves in the modulation of Cysteinyl leukotriene receptor 1 (CysLT1) expression in bronchial epithelial cells.Methods The bronchial epithelial cell lines 16HBE cells were stimulated with different concentration (0.00,0.05,0.50,5.00,20.00 μg/L) of TNF-α for 48 hours,and CysLT1 mRNA in 16HBE cells was measured by reverse transcription(RT)-PCR.CysLT1 expression was detected by immunohistochemistry.Results 16HBE cells did not express CysLT1,after the cells were treated with TNF-α,obvious expression of CysLT1 were detected by immunohistochemistry.The weak CysLT1 mRNA expression was observed by RT-PCR in 16HBE cells,and after the cells were treated with TNF-α for 48 hours,CysLT1 mRNA expression were upregulated.When the concentrations of TNF-α were 0.00,0.05,0.50,5.00,and 20.00 μg/L respectively,the relative intensities of CysLT1 mRNA/β-actin were 0.048,0.105,0.177,0.182,0.495,respectively.Conclusions TNF-α can upregulate CysLT1 mRNA expression in 16HBE ceils in a dose-dependent manner.When infected by virus,respiratory tract produces abundant TNF-α.The TNF-α can upregulate the expression of CysLT1 in epithelial cells,enhance inflammation reaction in respiratory tract.This may explain partially the mechanism of exacerbation of asthma induced by respiratory tract infection.
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Background: Cysteinyl leukotrienes have been shown to play an important role in the pathogenesis of asthma. The effect of the leukotriene receptor antagonist, montelukast, on bronchial hyperreactivity (BHR) as measured by the methacholine challenge test in school children has not been reported. Objective: To determine the effect of montelukast (Singulairâ) on BHR measured by methacholine challenge and lung function tests in Thai asthmatic children aged 6-13 years. Materials and methods: This was a randomized, double-blind, placebo-controlled, crossover study performed in 29 mild to moderate persistent asthmatic children aged 6-13 years. Each child received crossover treatment with 6 weeks of montelukast (5 mg/day) and 6 weeks of placebo separated by a two-week washout period. Results: The improvement of FEV1 and FEV1/FVC after 6 weeks of treatment was significantly higher in montelukast group compared to those of placebo group (p<0.05). After 6 weeks of treatment, mean (+ SEM) PC was 20 in the placebo group (5.7 + 1.41 mg/ml) which was lower than in montelukast group (6.8 + 1.74 mg/ml) but there was no significant difference (p=0.79). Conclusion: Montelukast significantly improved FEV1 and FEV1/FVC but not BHR in mild to moderate persistent asthmatic children aged 6-13 years after the 6 weeks of treatment.
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PURPOSE: Cysteinyl leukotrienes are important proinflammatory mediators in asthma. Recently, it was suggested that a promoter polymorphism in the genes encoding for leukotriene C4 synthase (LTC4S), a key enzyme in the leukotriene synthetic pathway, and cysteinyl leukotriene receptor 1 (CysLTR1) might be associated with aspirin-intolerant asthma. We investigated whether polymorphisms in LTC4S and CysLTR1 genes or their interactions were associated with the asthma phenotype, lung function, or bronchial hyperreactivity (BHR) in Korean children. METHODS: A total of 856 asthmatic children and 254 non-asthmatic controls were enrolled; a skin prick test, lung function test and bronchial provocation test were performed. Of those enrolled, 395 children underwent exercise challenge tests. The LTC4S A(-444)C and CysLTR1 T(+927)C were genotyped by polymerase chain reaction-restriction fragment length polymorphism analysis. RESULTS: Of those enrolled, 699 children were classified as having atopic asthma and 277 children, as having exercise-induced asthma (EIA). LTC4S and CysLTR1 polymorphisms were not associated with atopic asthma, EIA, or asthma per se. Lung function and BHR were not significantly different between the wild type (AA or TT) and the variant (AC+CC or TC+CC) genotypes in asthmatics, atopic asthmatics, and EIA (+) asthmatics, while total eosinophil counts were higher in the variant type of LTC4S than in the wild type in atopic asthmatics. There were no associations between the gene-gene interactions of LTC4S and CysLTR1 genotypes and the asthma phenotypes. CONCLUSION: LTC4S A(-444)C and CysLTR1 T(+927)C polymorphisms and their gene-gene interactions are not associated with asthma phenotype, lung function, or BHR in Korean children.
Subject(s)
Child , Humans , Asthma , Asthma, Exercise-Induced , Bronchial Hyperreactivity , Bronchial Provocation Tests , Eosinophils , Genotype , Leukotriene C4 , Leukotrienes , Lung , Phenotype , Receptors, Leukotriene , Respiratory Function Tests , SkinABSTRACT
Aim To determine whether pranlukast (ONO-1078), a cysteinyl leukotriene receptor antagonist, possesses therapeutic effect when administered after focal cerebral ischemia in mice. Methods Persistent focal cerebral ischemia was induced by middle cerebral artery occlusion. Pranlukast and edaravone, a positive control drug, were ip injected 1, 6 and 24 h after ischemia. The neurological deficits were evaluated by neurological scores and inclined plane test 24 and 48 h after the surgery. Forty-eight h later, the brain slices were prepared for measurements of infarct volume and the ratio of ischemic/non-ischemic hemispheres. Brain sections were cut and examined for neuron densities in different regions of the brain. The effects of pranlukast and edaravone were evaluated by the changes of these variables. Results Pranlukast (0.1 and 0.2 mg?kg -1) and edaravone (3 and 10 mg?kg -1) significantly reduced the neurological deficits, infarct volume (maximally 82.3%), ratio of ischemic/non-ischemic hemispheres, and attenuated the reduction of neuron densities in hippocampal CA1 region, cortex and striatum. Conclusion Pranlukast possesses therapeutic effect on ischemic insults when administered after ischemia as effective as edravone, indicating a therapeutic potential in the treatment of ischemic stroke.
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BACKGROUND: Cysteinyl leukotrienes are important inflammatory mediators in bronchial asthma because they enhance microvascular permeability, increase nonspecific bronchial hyperresponsiveness, and are potent bronchoconstrictor agents. Leukotriene E4 is a major metabolite of cysteinyl leukotriene excreted in urine and its concentration of urine can be a reliable marker of the overall leukotriene production in the body. OBJECTIVE: To determine whether clinical parameters of bronchial asthma are associated with production of cysteinyl leukotrienes, expressed by urinary leukotriene E4. METHOD: We measured the urinary concentration of leukotriene E4 in bronchial asthma(127 patients) and normal control(15 persons) group by ELISA method. Pulmonary function test, allergic skin test, measurement of peripheral eosinophil count and eosinophil cationic protein were undertaken in bronchial asthma patients. RESULTS: The concentrations of urinary leukotriene E4 were significantly higher in bronchial asthma patients than normal controls (p<0.05). The increased concentrations of leukotriene E4 had a significant correlation with FEV1/FVC or methacholine PC20(p<0.05). However, the concentration of leukotriene E4 did not have any correlation with the presence of atopy, peripheral blood eosinophil count, and eosinophil cationic protein level. CONCLUSION: The concentration of urinary leukotriene E4 that represents the overall leukotriene production in the body is correlated with the degree of airway obstruction and airway hyperresponsiveness. So, the concentration of urinary leukotriene E4 may be used as an adjunctive parameter of airway obstruction and hyperresponsiveness in bronchial asthma.