OBJECTIVE: : To investigate the effects of cysteinyl leukotrienes receptor (CysLTR) antagonists on global cerebral ischemia/reperfusion (CI/R) injury in gerbils, and to explore its mechanism. METHODS: : Totally 40 gerbils weighting 45-65 g were randomized into sham, saline, Pranlukast and HAMI 3379 groups with 10 animals in each. The CI/R model was established in gerbils by bilateral common carotid occlusion for 10 min followed by reperfusion. After ischemia, the CysLTR antagonists Pranlukast (0.1 mg/kg) and HAMI 3379 (0.1 mg/kg) were injected intraperitoneally for 5 consecutive days in the last two groups,while the former two groups were injected with saline only (10 mL/kg). After 24 h or 14 d reperfusion, neurological deficit score was evaluated and the behavioral dysfunction was assessed, respectively. And 14 d after reperfusion, the neuron morphology of cerebral cortex was observed in brain sections stained with Cresyl violet. In addition, the Iba-1 (microgila) and GFAP (astrocyte) positive cells in cerebral cortex were observed by using immunohistochemitry method. RESULTS: : CI/R models were successfully established in 21 out of 30 gerbils with 7 in saline group, 6 in Pranlukast group, and 8 in HAMI 3379 group. Compared with saline group, Pranlukast and HAMI 3379 significantly attenuated neurological deficits, improved the behavioral function 24 h after reperfusion(all <0.01); Pranlukast and HAMI 3379 also significantly improved the behavioral function 14 days after reperfusion(<0.05 or <0.01). Compared with saline group, the neurological symptom scores in Pranlukast and HAMI 3379 groups presented a trend of amelioration 14 d after reperfusion, but it was not significant(>0.05). In addition, Pranlukast and HAMI 3379 also inhibited the neuron loss and injury, suppressed microgila and astrocyte activation 14 d after reperfusion(all <0.01). CONCLUSIONS : CysLTR antagonists Pranlukast and HAMI 3379 have long-term neuroprotective effect on chronic brain injury induced by global cerebral ischemia/reperfusion in gerbils.
Animals ; Behavior, Animal ; drug effects ; Brain Injury, Chronic ; drug therapy ; Brain Ischemia ; Gerbillinae ; Leukotriene Antagonists ; pharmacology ; therapeutic use ; Neuroprotective Agents ; pharmacology ; therapeutic use ; Random Allocation ; Receptors, Leukotriene ; metabolism ; Reperfusion Injury ; drug therapy

PURPOSE: The aim of this study was to investigate whether pathologic changes in zonula occludens-1 (ZO-1) are induced by interleukin-13 (IL-13) in the experimental minimal-change nephrotic syndrome (MCNS) model and to determine whether montelukast, a leukotriene receptor antagonist, has an effect on ZO-1 restoration in cultured human podocytes. MATERIALS AND METHODS: Human podocytes cultured on bovine serum albumin-coated plates were treated with different doses of IL-13 and montelukast and then examined for distribution using confocal microscopy and for ZO-1 protein levels using Western blotting. RESULTS: ZO-1 was internalized and shown to accumulate in the cytoplasm of human podocytes in an IL-13 dose-dependent manner. High doses (50 and 100 ng/mL) of IL-13 decreased the levels of ZO-1 protein at 12 and 24 h (both p<0.01; n=3), which were significantly reversed by a high dose (0.5 microM) montelukast treatment (p<0.01; n=3). CONCLUSION: Our results suggest that IL-13 alters the expression of ZO-1, and such alterations in the content and distribution of ZO-1 may be relevant in the pathogenesis of proteinuria in the MCNS model.
Acetates/*pharmacology ; Blotting, Western ; Dose-Response Relationship, Drug ; Humans ; Interleukin-13/*pharmacology ; Leukotriene Antagonists/*pharmacology ; Microscopy, Confocal ; Podocytes/*drug effects/metabolism ; Proteinuria/pathology ; Quinolines/*pharmacology ; Tight Junctions ; Zonula Occludens-1 Protein/*metabolism

PURPOSE: The aim of this study was to investigate whether pathologic changes in zonula occludens-1 (ZO-1) are induced by interleukin-13 (IL-13) in the experimental minimal-change nephrotic syndrome (MCNS) model and to determine whether montelukast, a leukotriene receptor antagonist, has an effect on ZO-1 restoration in cultured human podocytes. MATERIALS AND METHODS: Human podocytes cultured on bovine serum albumin-coated plates were treated with different doses of IL-13 and montelukast and then examined for distribution using confocal microscopy and for ZO-1 protein levels using Western blotting. RESULTS: ZO-1 was internalized and shown to accumulate in the cytoplasm of human podocytes in an IL-13 dose-dependent manner. High doses (50 and 100 ng/mL) of IL-13 decreased the levels of ZO-1 protein at 12 and 24 h (both p<0.01; n=3), which were significantly reversed by a high dose (0.5 microM) montelukast treatment (p<0.01; n=3). CONCLUSION: Our results suggest that IL-13 alters the expression of ZO-1, and such alterations in the content and distribution of ZO-1 may be relevant in the pathogenesis of proteinuria in the MCNS model.
Acetates/*pharmacology ; Blotting, Western ; Dose-Response Relationship, Drug ; Humans ; Interleukin-13/*pharmacology ; Leukotriene Antagonists/*pharmacology ; Microscopy, Confocal ; Podocytes/*drug effects/metabolism ; Proteinuria/pathology ; Quinolines/*pharmacology ; Tight Junctions ; Zonula Occludens-1 Protein/*metabolism

OBJECTIVETo investigate the antioxidative effects of two cysteinyl leukotriene receptors antagonists (CysLT1R and CysLT2R) montelukast and HAMI 3379 on ischemic injury of rat cortical neurons in vitro.

METHODSCultured rat cortical neurons were pretreated with CysLT1R antagonist montelukast and CysLT2R antagonist HAMI 3379, and then exposed to oxygen-glucose deprivation/recovery (OGD/R）or H2O2. Reactive oxygen species (ROS) mitochondrial membrane potential (MMP) depolarization, neuronal viability and lactate dehydrogenase (LDH) release were determined. Meanwhile, RNA interference was used to inhibit the expression of CysLT1R and CysLT2R，and the effects were observed.

RESULTSROS production in neurons was significantly increased after 1 h OGD, which reached the peak at 30 min and lasted for 1.5 h after recovery. Montelukast and HAMI 3379 at 0.01-1μmol/L moderately decreased OGD/R-induced ROS production (P<0.05). Montelukast mildly attenuated OGD/R-induced MMP depolarization (P<0.05)，but HAMI 3379 had no effect. H2O2 reduced neuronal viability and increased LDH release, namely inducing neuronal injury. Montelukast and HAMI 3379 at 0.1-1μmol/L moderately attenuated H2O2-induced neuronal injury (P<0.05). However, both CysLT1R siRNA and CysLT2R shRNA did not significantly affect the responses mentioned above.

CONCLUSIONIn ischemic neuronal injury, montelukast and HAMI 3379 exert a moderate antioxidative effect, and this effect may be receptor-independent.

Acetates ; pharmacology ; Animals ; Antioxidants ; pharmacology ; Cell Hypoxia ; drug effects ; Cell Survival ; drug effects ; Cells, Cultured ; Cerebral Cortex ; cytology ; Cyclohexanecarboxylic Acids ; pharmacology ; Leukotriene Antagonists ; pharmacology ; Neurons ; drug effects ; metabolism ; Phthalic Acids ; pharmacology ; Quinolines ; pharmacology ; Rats ; Reactive Oxygen Species ; metabolism

OBJECTIVETo investigate the effect of montelukast on the expression of sensory neuropeptide (neurokinin-1) receptor (NK1R) in young asthmatic rats with airway remodeling.

METHODSTwenty-four Sprague-Dawley rats were randomly divided into control group (n=8), asthma (n=8), and montelukast groups (n=8). A rat model of asthma was induced by ovalbumin (OVA) inhalation. Normal saline was used instead of sensitizing solution and 1% OVA in the control group. Each rat in the montelukast group was given montelukast (15 mg/kg) by gavage 2 h before OVA inhalation. All rats received their respective treatments for 8 weeks. Immunohistochemistry, real-time PCR and Western blot were used to measure the mRNA and protein expression levels of NK1R in asthmatic airway remolding and to evaluate the effect of montelukast on NK1R expression.

RESULTSThe asthma group showed significantly higher mRNA and protein expression levels of NK1R than the control group (P<0.01). The mRNA and protein expression levels of NK1R in the montelukast group were significantly lower than in the asthma group (P<0.05), but significantly higher than in the control group (P<0.01).

CONCLUSIONSRats with induced asthma have upregulated NK1R expression in the airway, and montelukast can downregulate NK1R expression during airway remodeling.

Acetates ; pharmacology ; Airway Remodeling ; drug effects ; Animals ; Anti-Asthmatic Agents ; pharmacology ; Asthma ; drug therapy ; metabolism ; Female ; Leukotriene Antagonists ; pharmacology ; Quinolines ; pharmacology ; RNA, Messenger ; analysis ; Rats ; Rats, Sprague-Dawley ; Receptors, Neurokinin-1 ; analysis ; genetics

OBJECTIVETo investigate the effects of CysLT receptor agonist leukotriene D4(LTD4) and antagonists on activation of microglia BV2 cells.

METHODSThe expression of CysLT1 and CysLT2 protein was determined by Western blotting and immunostaining in microglia BV2 cells. BV2 cells were pretreated with or without CysLT1 receptor selective antagonist montelukast, CysLT2 receptor selective antagonist HAMI 3379, or CysLT1/CysLT2 receptor dual antagonist BAY u9773 for 30 min, then the cells were treated with LTD4 for 24 h. Cell viability was detected by MTT reduction assay. Phagocytosis and mRNA expression of IL-6 were determined by fluorescent bead tracking and RT-PCR, respectively.

RESULTSIn BV2 cells, LTD4 did not affect proliferation but significantly enhanced phagocytosis and increased IL-6 mRNA expression in a concentration-dependent manner. LTD4 at 100 nmol/L induced a 1.4-fold increase of phagocytic index and a 2-fold up-regulation of IL-6 mRNA expression (P<0.01). HAMI 3379 and BAY u9773 (100 nmol/L) further increased LTD4-induced phagocytosis; BAY u9773 and montelukast decreased LTD4-induced IL-6 mRNA expression, while HAMI 3379 had no effect on that.

CONCLUSIONLTD4 activates BV2 cells in vitro and enhances IL-6 mRNA expression mediated by CysLT1 receptor, LTD4 induces phagocytosis which might be negatively regulated by CysLT2 receptor in BV2 cells.

Acetates ; pharmacology ; Cell Line ; Cell Proliferation ; Cyclohexanecarboxylic Acids ; pharmacology ; Humans ; Interleukin-6 ; metabolism ; Leukotriene Antagonists ; pharmacology ; Leukotriene D4 ; pharmacology ; Microglia ; cytology ; metabolism ; Phagocytosis ; Phthalic Acids ; pharmacology ; Quinolines ; pharmacology ; Receptors, Leukotriene ; metabolism ; SRS-A ; analogs & derivatives ; pharmacology

OBJECTIVETo determine the effect of montelukast, a cysteinyl leukotriene receptor 1 antagonist, on morphological changes in rat neurons after ischemic injury.

METHODSThe in vivo ischemia injury was induced by oxygen-glucose deprivation (OGD) for 2 h and reperfusion (R) for 24 h (OGD/R) in rat neurons primary culture and mixed cortex culture. In the presence or absence of various concentrations of montelukast, neuron number, area of neuron, number of neuritis per neuron, branch number of primary neuritis and primary neurite length were determined for evaluating morphological changes in neurons.

RESULTSOGD/R significantly reduced neuron number, and altered neuron morphology. In cortical neuron cultures, montelukast (0.0001-1 μmol/L) attenuated OGD/R-induced reduction in neuron number, and inhibited OGD/R-induced increase in branch number of primary neuritis. In the mixed cultures, montelukast (0.0001-0.1 μmol/L) increased the primary neurite length, and reduced number of neuritis and branch number of primary neurite after OGD/R.

CONCLUSIONMontelukast has a protective effect on ischemic injury in neurons.

Acetates ; pharmacology ; Animals ; Animals, Newborn ; Cell Hypoxia ; drug effects ; Cell Survival ; drug effects ; Cells, Cultured ; Glucose ; pharmacology ; Leukotriene Antagonists ; pharmacology ; Neurons ; drug effects ; pathology ; Neuroprotective Agents ; pharmacology ; Quinolines ; pharmacology ; Rats ; Rats, Sprague-Dawley

The incidence rates of urinary bladder cancer continue to rise yearly, and thus new therapeutic approaches and early diagnostic markers for bladder cancer are urgently needed. Thus, identifying the key mediators and molecular mechanisms responsible for the survival of bladder cancer has valuable implications for the development of therapy. In this study, the role of BLT2, a receptor for leukotriene B4 (LTB4) and 12(S)-hydroxyeicosatetraenoic acid (HETE), in the survival of bladder cancer 253J-BV cells was investigated. We found that the expression of BLT2 is highly elevated in bladder cancer cells. Also, we observed that blockade of BLT2 with an antagonist or BLT2 siRNA resulted in cell cycle arrest and apoptotic cell death, suggesting a role of BLT2 in the survival of human bladder cancer 253J-BV cells. Further experiments aimed at elucidating the mechanism by which BLT2 mediates survival revealed that enhanced level of reactive oxygen species (ROS) are generated via a BLT2-dependent up-regulation of NADPH oxidase members NOX1 and NOX4. Additionally, we observed that inhibition of ROS generation by either NOX1/4 siRNAs or treatment with an ROS-scavenging agent results in apoptotic cell death in 253J-BV bladder cancer cells. These results demonstrated that a 'BLT2-NOX1/4-ROS' cascade plays a role in the survival of this aggressive bladder cancer cells, thus pointing to BLT2 as a potential target for anti-bladder cancer therapy.
*Apoptosis ; Blotting, Western ; Cell Proliferation ; Cells, Cultured ; Gene Expression Regulation, Neoplastic/*physiology ; Humans ; Leukotriene Antagonists/pharmacology ; NADPH Oxidase/antagonists & inhibitors/genetics/metabolism ; Phosphorylation ; RNA, Messenger/genetics ; RNA, Small Interfering/genetics ; Reactive Oxygen Species/*metabolism ; Receptors, Leukotriene B4/antagonists & inhibitors/*genetics ; Reverse Transcriptase Polymerase Chain Reaction ; Signal Transduction ; Tetrazoles/pharmacology ; Up-Regulation ; Urinary Bladder Neoplasms/*genetics/mortality

OBJECTIVETo investigate the role of cysteinyl leukotriene (CysLT) receptors in the differentiation of rat glioma C6 cells.

METHODSRat glioma C6 cells were treated with the agonist LTD(4), the CysLT(1) receptor antagonist montelukast and the differentiation inducer forskolin. Cell morphology and GFAP protein expression were determined after treatments.

RESULTForskolin (10 μmol/L) induced morphological changes and GFAP protein expression (cell differentiation) in C6 cells, but LTD(4) (0.1-100 nmol/L) did not induce these changes. Montelukast (1 μmol/L) alone did not affect C6 cell differentiation, while it induced the differentiation when combined with the LTD(4) (100 nmol/L).

CONCLUSIONThe CysLT(2) receptor may modulate the differentiation of rat glioma C6 cells.

Acetates ; pharmacology ; Animals ; Cell Differentiation ; drug effects ; Cell Line, Tumor ; Colforsin ; pharmacology ; Cysteine ; Glioma ; metabolism ; pathology ; Leukotriene Antagonists ; pharmacology ; Leukotriene D4 ; pharmacology ; Leukotrienes ; Quinolines ; pharmacology ; Rats ; Receptors, Leukotriene ; agonists

OBJECTIVE: To investigate the changes of leukotriene D4 (LTD4) in nasal discharge and plasma of patients with persistent allergic rhinitis (AR) and the effects of antihistamine. METHOD: The investigation was a prospective, randomized controlled trial. Forty AR patients (group C) were divided randomly into two subgroup. One group received oral antihistamine 10 mg everyday for one week (group CA) and another group received no loratadine tablets 10 mg everyday for one week (group CB). Fifteen age matched healthy (group D) people were enrolled as control. The level of LTD4 and interleukin-5 (IL-5) in both nasal discharge and plasma by using enzyme linked immunosorbent assay (ELISA) and enzyme immunoassay (EIA), cell counts and cell differentials in nasal discharge, were measured before and after three month. The clinical symptom and life quality scores of group C were also investigated. RESULT: The concentrations of LTD4 in nasal discharge [(794 +/- 305) pg] and plasma [(5219 +/- those in group D [(347 +/- 169) pg, (2283 +/- 489) ng/L, all P 1185) ng/L] in group C were significantly higher than those in group D [(347 +/- 169) pg, (2283 +/- 489) ng/L, all P < 0.05]. The level of LTD4 in nasal discharge was positively correlated with the percentage of neutrophil (r = 0.453, P < 0.05) and IL-5 (r = 0.364, P < 0.05). The pre- and post-therapy concentrations of nasal discharge and plasma in group CA were (812 +/- 1592) pg, (657 +/- 495) pg and (5422 +/- 935) ng/L, (4589 +/- 1057) ng/L respectively; While in group CB the concentrations were (776 +/- 227) pg, (860 +/- 194) pg and (5074 +/- 1850) ng/L, (6063 +/- 450) ng/L, respectively. There were no significant difference either in the level of LTD4 in nasal discharge or in plasma in both groups (all P > 0.05). CONCLUSION The results suggested that LTD4 was involved in airway inflammation in AR. Antihistamine was not effective enough in decreasing the levels of LTD4 in both nasal discharge and plasma of AR patients.
Adult ; Anti-Allergic Agents ; pharmacology ; Bodily Secretions ; chemistry ; Female ; Histamine H1 Antagonists ; pharmacology ; Humans ; Leukotriene Antagonists ; therapeutic use ; Leukotriene D4 ; analysis ; blood ; metabolism ; Male ; Middle Aged ; Plasma ; chemistry ; Prospective Studies ; Rhinitis, Allergic, Perennial ; blood ; drug therapy ; metabolism