leukotriene-c4 and Inflammation

Type I hypersensitivity is an immediate immune reaction that involves IgE-mediated activation of mast cells. Activated mast cells release chemical mediators, such as histamine and lipid mediators, which cause allergic reactions. Recent developments in detection devices have revealed that mast cells simultaneously release a wide variety of lipid mediators. Mounting evidence has revealed that mast cell-derived mediators exert both pro- and anti-inflammatory functions and positively and negatively regulate the development of allergic inflammation. This review presents the roles of major lipid mediators released from mast cells. Author believes this review will be helpful for a better understanding of the pathogenesis of allergic diseases and provide a new strategy for the diagnosis and treatment of allergic reactions.

Topics: Fatty Acids, Unsaturated; Histamine Release; Humans; Hydroxyeicosatetraenoic Acids; Hypersensitivity, Immediate; Immunoglobulin E; Inflammation; Leukotriene B4; Leukotriene C4; Lipid Metabolism; Mast Cells; Prostaglandin D2

The multidrug resistance protein 1 (MRP1) encoded by ABCC1 was originally discovered as a cause of multidrug resistance in tumor cells. However, it is now clear that MRP1 serves a broader role than simply mediating the ATP-dependent efflux of drugs from cells. The antioxidant GSH and the pro-inflammatory cysteinyl leukotriene C4 have been identified as key physiological organic anions effluxed by MRP1, and an ever growing body of evidence indicates that additional lipid-derived mediators are also substrates of this transporter. As such, MRP1 is a multitasking transporter that likely influences the etiology and progression of a host of human diseases.

Topics: Adenosine Triphosphate; Animals; Anions; Antioxidants; Biological Transport; Cell Line, Tumor; Estrogens; Glutathione; Humans; Inflammation; Leukotriene C4; Lipids; Lysophospholipids; Mice; Multidrug Resistance-Associated Proteins; Oxidative Stress; Oxygen; Signal Transduction; Xenobiotics

Topics: Arachidonic Acid; Aspirin; Asthma; Desensitization, Immunologic; Drug Hypersensitivity; Humans; Inflammation; Leukotriene C4; Nasal Polyps; Prostaglandin-Endoperoxide Synthases; Rhinitis; Sinusitis

Topics: Animals; Cell Lineage; Corticotropin-Releasing Hormone; Cytokines; Histamine; Humans; Inflammation; Leukotriene C4; Mast Cells; Serine Endopeptidases

In our previous study, we found a new mixed formula of Chinese herbs containing Shin-yi-san + Xiao-qing-long-tang + Xiang-sha-liu-jun-zi-tang (9 + 3 + 3 g divided in three doses/day) was beneficial to the patients with perennial allergic rhinitis (AR) via complicated immunomodulatory effects on both mononuclear cells (MNC) and polymorphonuclear neutrophils (PMN). In the present study, we further determined the effects of nasal fluid from AR patients on the functions of human PMN before and after treatment with the mixed formula. We found the nasal discharge, but not serum, from AR group with high serum IgE (H-IgE, serum IgE >200 KIU/l) before treatment exerted many stimulating effects on normal PMN including delayed apoptosis, enhanced production of soluble intercellular adhesion molecule 1 (sICAM-1), interleukin 8 (IL-8) and prostaglandin E2 (PGE2), increased phagocytosis, and augmented cyclooxygenase 2 (COX-2) mRNA expression of PMN. However, these stimulating effects of nasal fluid on PMN were not found in low IgE group (L-IgE, serum IgE <200 KIU/l). These PMN-enhancing effects of H-IgE nasal fluid were abolished after 3-month treatment with the mixed Chinese herb formula. In conclusion, our results suggest that the new mixed herb formula treatment suppressed nasal mucosa inflammation by normalizing stimulatory effects of allergic nasal discharge of patients with H-IgE allergic rhinitis.

Topics: Adolescent; Adult; Apoptosis; Cells, Cultured; Culture Media, Conditioned; Cyclooxygenase 2; Dinoprostone; Drugs, Chinese Herbal; Female; Humans; Immunoglobulin E; Inflammation; Intercellular Adhesion Molecule-1; Interleukin-8; Isoenzymes; Leukotriene C4; Male; Membrane Proteins; Mucus; Nasal Mucosa; Neutrophils; Phagocytosis; Prostaglandin-Endoperoxide Synthases; Rhinitis, Allergic, Perennial; RNA, Messenger; Time Factors

Several studies have been demonstrated that endotoxin is a potent stimulus of the acute inflammatory response following traumatic injury. Although numerous studies have indicated that the extent of surgical intervention correlates well with the inflammatory response, the potential role of endotoxin as a trigger under those conditions still remains unknown. Therefore, the aim of this study was to elucidate whether or not the up-regulated inflammatory mediators are paralleled by increased endotoxin plasma levels during and following surgery, and whether the extent of surgical intervention represents a crucial factor under those conditions. To study this, plasma was collected at various time points during and after surgery from 52 patients subjected to abdominal surgery (i.e., major surgery) and 25 patients subjected to thyroid surgery (i.e., minor surgery). Plasma was assessed for endotoxin, endotoxin neutralizing capacity (ENC), and inflammatory mediators (leucotriene-C4 [LTC4]-, 6-keto-prostaglandin-F-1-alpha [PGF]-, thromboxane-B2 [TxB2], interleukin-6 [IL-6], and C-reactive protein [CRP]). Furthermore, splanchnic blood circulation was measured by determination of the intraluminal pH of the stomach and sigma (pHi) by intraluminal tonometry. Mesenteric lymph nodes were also collected at the time point of organ mobilization in the major surgery group and were assessed for bacterial translocation. Among all parameters investigated, endotoxin showed the most rapid changes. A significant increase in plasma levels of endotoxin and a decrease of ENC were found in the major surgery groups following induction of anesthesia and in the minor surgery groups after skin incision. Moreover, the incidence of elevated endotoxin levels was significantly higher (89% with elevated endotoxin levels) than the incidence of bacterial translocation (35% with gram-negative bacteria) in mesenterial lymph nodes of the major surgery group. pHi decreased significantly in both groups after skin incision, but no difference was observed between the major and minor surgery groups. Plasma mediators of the arachidonic acid cascade (LTC4, PGF, and TxB2) were only elevated in individual patients during and following surgery in both groups. Conversely, the post-operative increase in the acute phase mediators was significantly different in the major and minor surgery groups. IL-6 plasma levels peaked higher and earlier after major surgery than after minor surgery and the delayed increase of CR

Topics: 6-Ketoprostaglandin F1 alpha; Abdomen; Arachidonic Acids; Bacterial Translocation; C-Reactive Protein; Endotoxins; Humans; Hydrogen-Ion Concentration; Inflammation; Interleukin-6; Leukotriene C4; Prospective Studies; Splanchnic Circulation; Surgical Procedures, Operative; Thyroid Gland; Time Factors

Bronchoalveolar lavage (BAL) was used to sample lung cells and biochemical components in the lung air spaces at various times from 1 to 91 d after intrapulmonary instillation of 2.6 microm-diameter iron oxide particles in human subjects. The instillation of particles induced transient acute inflammation during the first day post instillation (PI), characterized by increased numbers of neutrophils and alveolar macrophages as well as increased amounts of protein, lactate dehydrogenase, and interleukin-8 in BAL fluids. This response was subclinical and was resolved within 4 d PI. A similar dose-dependent response was seen in rats 1 d after intratracheal instillation of the same particles. The particles contained small amounts of soluble iron (240 ng/mg) and possessed the capacity to catalyze oxidant generation in vitro. Our findings indicate that the acute inflammation after particle exposure may, at least partially, be the result of oxidant generation catalyzed by the presence of residual amounts of ferric ion, ferric hydroxides, or oxyhydroxides associated with the particles. These findings may have relevance to the acute health effects associated with increased levels of ambient particulate air pollutants.

Topics: Adult; Animals; Bronchoalveolar Lavage; Bronchoalveolar Lavage Fluid; Dinoprostone; Female; Ferric Compounds; Humans; Inflammation; Instillation, Drug; Interleukin-8; Iron; L-Lactate Dehydrogenase; Leukotriene C4; Leukotriene E4; Lung; Macrophages, Alveolar; Male; Neutrophils; Phagocytosis; Rats; Time Factors

Topics: Animals; Anti-Allergic Agents; Asthma; Cytokines; Disease Models, Animal; Immunoglobulin E; Inflammation; Leukotriene B4; Leukotriene C4; Lung; Mice; Mice, Inbred BALB C; Mucoproteins; Respiratory Hypersensitivity

Ecklonia cava is an edible marine brown alga harvested from the ocean that is widely consumed in Asian countries as a health-promoting medicinal food The objective of the present study is to evaluate the anti-asthma mechanism of a new functional food produced by bioprocessing edible algae Ecklonia cava and shiitake Lentinula edodes mushroom mycelia and isolated fractions.. We used as series of methods, including high performance liquid chromatography, gas chromatography, cell assays, and an in vivo mouse assay to evaluate the asthma-inhibitory effect of Ecklonia cava bioprocessed (fermented) with Lentinula edodes shiitake mushroom mycelium and its isolated fractions in mast cells and in orally fed mice.. The in vitro cell and in vivo mouse assays demonstrate the potential value of the new bioprocessed formulation as an anti-inflammatory and anti-allergic combination of natural compounds against allergic asthma and might also ameliorate allergic manifestations of foods, drugs, and viral infections.

Topics: Agaricales; Aluminum Oxide; Animals; Anti-Allergic Agents; Anti-Asthmatic Agents; Anti-Inflammatory Agents; Asthma; Cytokines; Immunoglobulin E; Inflammation; Interleukin-10; Leukotriene C4; Mice; Mice, Inbred BALB C; Mycelium; Ovalbumin; Phaeophyceae; Prostaglandin D2; Shiitake Mushrooms; Vascular Cell Adhesion Molecule-1

Specific blocking strategies of TLR2-mediated inflammatory signaling and hypersensitivity reactions may offer novel therapeutic strategies to prevent a variety of diseases. In this study, we investigated the blocking effects of a new anti-TLR2 antibody anti-T20 against a 20 mer peptide T20 located in the extracellular specific domain of mouse TLR2. In addition, the effects of the anti-T20 in vitro, measuring the inhibition of the IL-6 and TNF-α production in response to PGN, LTA, and Pam3CSK4-stimulated RAW264.7 cells, were determined. In vivo, the effects of anti-T20 on a lethal anaphylaxis model using PGN-challenged OVA allergic mice, including the rectal temperature and mortality, and serum levels of TNF-α, IL-6, and LTC4 were assayed. The results showed that anti-T20 specifically bound to TLR2 and significantly inhibited PGN, LTA, and Pam3CSK4-driven TNF-α and IL-6 production by RAW264.7 cells. Also, anti-T20 protected OVA allergic mice from PGN-induced lethal anaphylaxis, and the serum levels of TNF-α, IL-6, and LTC4 of anti-T20 treated PGN-challenged OVA allergic mice were decreased as compared to isotype control of anti-T20 treated mice. In summary, this study produced a new antibody against the specific extracellular domain of TLR2 which has protective effect on TLR2 agonists-driven inflammatory and allergic response.

Topics: Animals; Antibodies, Anti-Idiotypic; Enfuvirtide; Gene Expression Regulation; HIV Envelope Protein gp41; Humans; Hypersensitivity; Inflammation; Interleukin-6; Leukotriene C4; Mice; Peptide Fragments; Protein Domains; RAW 264.7 Cells; Toll-Like Receptor 2; Tumor Necrosis Factor-alpha

Cysteinyl leukotrienes (cysLTs) are bronchoconstricting lipid mediators that amplify eosinophilic airway inflammation by incompletely understood mechanisms. We recently found that LTC4, the parent cysLT, potently activates platelets in vitro and induces airway eosinophilia in allergen-sensitized and -challenged mice by a platelet- and type 2 cysLT receptor-dependent pathway. We now demonstrate that this pathway requires production of thromboxane A2 and signaling through both hematopoietic and lung tissue-associated T prostanoid (TP) receptors. Intranasal administration of LTC4 to OVA-sensitized C57BL/6 mice markedly increased the numbers of eosinophils in the bronchoalveolar lavage fluid, while simultaneously decreasing the percentages of eosinophils in the blood by a TP receptor-dependent mechanism. LTC4 upregulated the expressions of ICAM-1 and VCAM-1 in an aspirin-sensitive and TP receptor-dependent manner. Both hematopoietic and nonhematopoietic TP receptors were essential for LTC4 to induce eosinophil recruitment. Thus, the autocrine and paracrine functions of thromboxane A2 act downstream of LTC4/type 2 cysLT receptor signaling on platelets to markedly amplify eosinophil recruitment through pulmonary vascular adhesion pathways. The findings suggest applications for TP receptor antagonists in cases of asthma with high levels of cysLT production.

Topics: Allergens; Animals; Aspirin; Asthma; Blood Platelets; Bone Marrow Transplantation; Bronchoalveolar Lavage Fluid; Cysteine; Eosinophilia; Inflammation; Intercellular Adhesion Molecule-1; Leukotriene Antagonists; Leukotriene C4; Leukotrienes; Lung; Mice; Mice, Inbred C57BL; Mice, Knockout; Ovalbumin; Platelet Activation; Receptors, Prostaglandin; Thromboxane A2; Vascular Cell Adhesion Molecule-1

Allergic diseases, such as asthma and allergic rhinitis, are common. Therefore, the discovery of therapeutic drugs for these conditions is essential. Methyleugenol (ME) is a natural compound with antiallergic, antianaphylactic, antinociceptive, and anti-inflammatory effects. This study examined the antiallergic effect of ME on IgE-mediated inflammatory responses and its antiallergy mechanism in the mast cell line, RBL-2H3. We found that ME significantly inhibited the release of β-hexosaminidase, tumor necrosis factor- (TNF-) α, and interleukin- (IL-) 4, and was not cytotoxic at the tested concentrations (0-100 μM). Additionally, ME markedly reduced the production of the proinflammatory lipid mediators prostaglandin E2 (PGE2), prostaglandin D2 (PGD2), leukotriene B4 (LTB4), and leukotriene C4 (LTC4). We further evaluated the effect of ME on the early stages of the FcεRI cascade. ME significantly inhibited Syk phosphorylation and expression but had no effect on Lyn. Furthermore, it suppressed ERK1/2, p38, and JNK phosphorylation, which is implicated in proinflammatory cytokine expression. ME also decreased cytosolic phospholipase A2 (cPLA2) and 5-lipoxygenase (5-LO) phosphorylation and cyclooxygenase-2 (COX-2) expression. These results suggest that ME inhibits allergic response by suppressing the activation of Syk, ERK1/2, p38, JNK, cPLA2, and 5-LO. Furthermore, the strong inhibition of COX-2 expression may also contribute to the antiallergic action of ME. Our study provides further information about the biological functions of ME.

Topics: Animals; Arachidonic Acid; beta-N-Acetylhexosaminidases; Cell Line, Tumor; Cell Respiration; Dinoprostone; Eugenol; Extracellular Signal-Regulated MAP Kinases; Hypersensitivity; Immunoenzyme Techniques; Immunoglobulin E; Inflammation; Interleukin-4; Leukotriene B4; Leukotriene C4; Mast Cells; Mutagens; Prostaglandin D2; Rats; Tumor Necrosis Factor-alpha

Leukotrienes (LT) are a family of drug-like molecules involved in the pathobiology of bronchial asthma and are responsible for smooth muscle contraction. Leukotriene C4 synthase (LTC4S) is a nuclear-membrane enzyme responsible for the conjugation of leukotriene A4 (LTA4) to glutathione to form LTC4, a cysteinyl leukotriene. In this study, the mechanism of LTA4 binding by LTC4S has been computationally examined. More specifically, docking and molecular dynamics simulations were used to gain insight into the substrate-bound active site. These studies identified two possible orientations for bound LTA4: 'tail-to-head' and 'head-to-tail'. An ONIOM(QM/MM) approach was then used to elucidate the mechanism by which glutathione may add to LTA4. In particular, the thiolate of glutathione acts as a nucleophile attacking C6 of LTA4 forming a S-C6 bond. Concomitantly, a proton is transferred from the guanidinium of Arg31 to the epoxide ring oxygen. This results in opening of the epoxide ring and stabilization of the LTC4 product complex. Within the present computational methodology the 'tail-to-head' orientation appears to be the most likely substrate orientation.

Topics: Catalysis; Inflammation; Leukotriene C4; Molecular Dynamics Simulation; Quantum Theory

We studied the effect of lipopolysaccharide (LPS), proinflammatory cytokines (tumor necrosis factor α [TNF-α] and interleukin [IL]-1β), and anti-inflammatory cytokines (IL-4 and IL-10) on leukotriene (LT) A4 hydrolase and LTC4 synthase (LTCS) protein expression in, and LTB4 and LTC4 secretion from, an inflamed porcine endometrium. On day 3 of the estrous cycle (day 0 of the study), 50 mL of either saline or Escherichia coli suspension (10(9) CFU/mL) was injected into each uterine horn of gilts (n = 12 per group). Endometrial explants, obtained 8 and 16 days later, were incubated for 24 h with LPS (10 or 100 ng/mL of medium), TNF-α, IL-1β, IL-4, and IL-10 (each cytokine: 1 or 10 ng/mL of medium). Although acute endometritis developed in all bacteria-inoculated gilts, a severe form of acute endometritis was diagnosed more often on day 8 of the study than on day 16. The amount of the LTA4 hydrolase (LTAH) protein in the inflamed endometrium on day 8 was greater after applying the lower dose of TNF-α (P < 0.001) and both doses of IL-1β (P < 0.001) and IL-4 (1 ng, P < 0.01 and 10 ng, P < 0.001) than in the saline-treated uteri. A similar situation was observed in the case of the inflamed tissue on day 16 in response to LPS (100 ng, P < 0.01), TNF-α (10 ng, P < 0.05), and IL-4 (1 ng, P < 0.001). The content of LTC4 synthase in the inflamed endometrium on day 8 was reduced by LPS (100 ng, P < 0.05), IL-1β (10 ng, P < 0.05), IL-4 (1 and 10 ng, P < 0.05), and IL-10 (1 ng, P < 0.01) but increased after the application of LPS (100 ng, P < 0.05) and TNF-α (1 and 10 ng, P < 0.001), IL-1β, and IL-4 (1 ng, P < 0.05 and 10 ng, P < 0.001) on day 16. On day 8, endometrial secretion of LTB4 from the saline-injected and E coli-injected organs was similar in response to all of the used mediators. On the other hand, the contents of LTB4 in the medium decreased after incubating the inflamed tissues from day 16 with TNF-α (1 ng, P < 0.05 and 10 ng, P < 0.01), IL-1β (1 ng, P < 0.01), and IL-10 (10 ng, P < 0.05) compared with the saline-treated ones. Secretion of LTC4 from the inflamed uteri on day 8 was elevated by the lower doses of TNF-α (P < 0.01) and IL-10 (P < 0.05), whereas on day 16, such an effect occurred in response to the higher doses of IL-4 (P < 0.01) and IL-10 (P < 0.05). The obtained results show that pro- and anti-inflammatory mediators participate in the synthesis/secretion of LTs from an inflamed porcine endometrium. Our data suggest that inflammatory mediators

Topics: Animals; Cytokines; Endometriosis; Endometrium; Epoxide Hydrolases; Escherichia coli Infections; Female; Gene Expression Regulation; Glutathione Transferase; Inflammation; Leukotriene B4; Leukotriene C4; Lipopolysaccharides; Swine; Swine Diseases

The cysteinyl leukotrienes (cys-LTs), leukotriene C4 (LTC4), a conjugation product of glutathione and eicosatetraenoic acid, and its metabolites, LTD4 and LTE4, are lipid mediators of smooth muscle constriction and inflammation in asthma. LTD4 is the most potent ligand for the type 1 cys-LT receptor (CysLT1R), and LTC4 and LTD4 have similar lesser potency for CysLT2R, whereas LTE4 has little potency for either receptor. Cysltr1/Cysltr2(-/-) mice, lacking the two defined receptors, exhibited a comparable dose-dependent vascular leak to intradermal injection of LTC4 or LTD4 and an augmented response to LTE4 as compared with WT mice. As LTE4 retains a cysteine residue and might provide recognition via a dicarboxylic acid structure, we screened cDNAs within the P2Y nucleotide receptor family containing CysLTRs and dicarboxylic acid receptors with trans-activator reporter gene assays. GPR99, previously described as an oxoglutarate receptor (Oxgr1), showed both a functional and a binding response to LTE4 in these transfectants. We generated Gpr99(-/-) and Gpr99/Cysltr1/Cysltr2(-/-) mice for comparison with WT and Cysltr1/Cysltr2(-/-) mice. Strikingly, GPR99 deficiency in the Cysltr1/Cysltr2(-/-) mice virtually eliminated the vascular leak in response to the cys-LT ligands, indicating GPR99 as a potential CysLT3R active in the Cysltr1/Cysltr2(-/-) mice. Importantly, the Gpr99(-/-) mice showed a dose-dependent loss of LTE4-mediated vascular permeability, but not to LTC4 or LTD4, revealing a preference of GPR99 for LTE4 even when CysLT1R is present. As LTE4 is the predominant cys-LT species in inflamed tissues, GPR99 may provide a new therapeutic target.

Topics: Animals; Capillary Permeability; Inflammation; Leukotriene C4; Leukotriene D4; Leukotriene E4; Ligands; Mice; Mice, Inbred BALB C; Mice, Knockout; Receptors, Leukotriene

Although CD23-dependent transcytosis of IgE and IgE-derived immune complexes across respiratory epithelial cells is likely to play a pivotal role in the initiation and development of airway allergic inflammation, there is currently a lack of physiological support for this phenomena to suggest that the targeting of CD23 could be used as a means of therapeutic intervention. The present study was designed to detect the CD23 expression in the nasal mucosa of allergic rhinitis (AR) murine model by immunohistochemistry and western blotting, and to investigate whether intranasal anti-CD23 treatment could inhibit allergen-induced upper airway inflammation in the AR model. This is the first report to show that CD23 was constitutively expressed in murine nasal epithelial cells, and its expression was significantly up-regulated in the AR murine model. In vivo, the up-regulation of CD23 expression was correlated with increased serum IL-4 levels. Following intranasal anti-CD23 treatment, nasal symptoms were alleviated and histopathologic examination showed a significant decrease in eosinophilic infiltration. Meanwhile, ELISA analysis showed levels of serum leukotriene C4 (LTC4), eosinophil cation protein (ECP), ovalbumin (OVA)-specific IgE and IL-4 also significantly decreased, as were LTC4 and OVA-specific IgE in the nasal lavage fluid. Furthermore, Western blotting analysis showed that ECP expression in the nasal mucosa was down-regulated. Finally, flow cytometric analysis revealed anti-CD23 treatment inhibited Th2 cell responses. These results indicate that intranasal anti-CD23 treatment can reduce allergic responses in a murine model of allergic rhinitis.

Topics: Administration, Intranasal; Allergens; Animals; Budesonide; Disease Models, Animal; Down-Regulation; Eosinophil Cationic Protein; Eosinophils; Epithelial Cells; Female; Hypersensitivity; Immunoglobulin E; Inflammation; Interleukin-4; Leukotriene C4; Mice; Mice, Inbred BALB C; Nasal Mucosa; Ovalbumin; Random Allocation; Receptors, IgE; Rhinitis, Allergic; Rhinitis, Allergic, Perennial; Th2 Cells; Up-Regulation

In this study, the anti-inflammatory and anti-allergic effects of the chloroform-soluble extract of Agaricus blazei in mouse bone marrow-derived mast cells (BMMCs) were investigated. The chloroform-soluble extract inhibited IL-6 production in PMA plus A23187-stimulated BMMCs, and down-regulated the phosphorylation of Akt. In addition, this extract demonstrated inhibition of the degranulation of β-hexosaminidase and the production of IL-6, prostaglandin D(2) and leukotriene C(4) in PMA plus A23187-induced BMMCs. In conclusion, the chloroform-soluble extract of Agaricus blazei exerted anti-inflammatory and anti-allergic activities mediated by influencing IL-6, prostaglandin D(2), leukotriene C(4), and the phosphorylation of Akt.

Topics: Agaricus; Animals; Anti-Allergic Agents; Anti-Inflammatory Agents; beta-N-Acetylhexosaminidases; Biological Products; Bone Marrow Cells; Calcimycin; Cell Degranulation; Down-Regulation; Female; Inflammation; Interleukin-6; Leukotriene C4; Mast Cells; Mice; Mice, Inbred BALB C; Phosphorylation; Phytotherapy; Prostaglandin D2; Proto-Oncogene Proteins c-akt; Tetradecanoylphorbol Acetate

To explore the characteristics of airway inflammatory cells, cytokines and inflammatory mediators in eosinophilic bronchitis (EB) and cough variant asthma (CVA) patients and to elucidate the underlying mechanism of distinct airway inflammation between EB and CVA.. This study included 15 patients with EB (EB group), 15 patients with cough variant asthma (CVA, CVA group), 14 patients with bronchial asthma (asthma group) and 14 healthy controls (healthy group). Percentage of eosinophils (EOS) in sputum induced by hypertonic saline was detected by FACS. The percentage of CD(69)(+) EOS stimulated by interleukin-5 (IL-5) and interferon γ (IFN-γ) was also detected by FACS. The expression of leukotriene C4 synthase (LTC4S) and prostaglandin-endoperoxide synthase-2 (PTGS2) mRNA in sputum was measured by real-time PCR and the concentration of leukotriene C4 (LTC4) and prostaglandin E2 (PGE2) in sputum was measured by ELISA.. The percentage of EOS in induced sputum was 15.8 ± 3.2 (EB group), 13.0 ± 2.7 (CVA group) and 11.6 ± 4.5 (asthma group), respectively, which were significantly higher than 1.0 ± 0.4 in the healthy group. The difference was significant and the t value was 16.31, 15.23 and 14.21 respectively (P < 0.05). After stimulated by IL-5 and IFN-γ, the percentage of CD(69)(+) EOS in induced sputum was 1.5 ± 0.4 and 1.5 ± 0.5 (EB group), 1.4 ± 0.4 and 1.4 ± 0.3 (CVA group) and 1.42 ± 0.72 and 1.37 ± 0.46 (asthma group) respectively. There was no statistical significance between these 3 groups, but when compared with 0.4 ± 0.2 and 0.4 ± 0.1 in healthy group, the difference was significant (P < 0.05). The expression of IL-5 mRNA and protein in induced sputum of EB group, CVA group and asthma group were higher than the healthy group and the difference was all statistically different (P < 0.05), but there was no statistical significance between EB group, CVA group and asthma group. The expression of IFN-γ mRNA and protein in induced sputum of each group was not different when compared with healthy group (P > 0.05). The concentration of PGE2 in induced sputum of EB group was(839 ± 69) ng/L, which was higher than (33 ± 8) ng/L of CVA group, (25 ± 6) ng/L of asthma group and (24 ± 8) ng/L of healthy group (all P < 0.01). There was no statistical difference between CVA group, asthma group and healthy group. The expression of PTGS2 in induced sputum of EB group increased significantly; when compared with CVA group, asthma group and healthy group, the difference was significant (all P < 0.01). The concentration of LTC4 in induced sputum of EB group, CVA group and asthma group was all higher than the healthy group (all P < 0.05). The expression of LTC4S mRNA of EB group, CVA group and asthma group was also higher than the healthy group (all P < 0.05). The expression of LTC4S mRNA and LTC4 in the EB group was higher than that in the CVA group and the asthma group (P < 0.05). The value of LTC4/PGE2 in the CVA group and the asthma group was higher than that in the EB group (t = 8.7 and 13.1, P < 0.05).. These data suggest that the difference in airway function observed in subjects with eosinophilic bronchitis and CVA (or asthma) may be due to the results of differences in PGE(2) production and an imbalance between the production of bronchoconstrictor LTC(4) and bronchoprotective PGE(2) lipid mediators.

Topics: Adult; Asthma; Bronchitis; Case-Control Studies; Cough; Dinoprostone; Eosinophilia; Female; Humans; Inflammation; Interleukin-5; Leukotriene C4; Male; Middle Aged; Sputum

In this study, manassantin A (Man A), an herbal medicine isolated from Saururus chinensis (S. chinensis), markedly inhibited 5-lipoxygenase (5-LO)-dependent leukotriene C(4) (LTC(4)) generation in bone marrow-derived mast cells (BMMCs) in a concentration-dependent manner. To investigate the molecular mechanisms underlying the inhibition of LTC(4) generation by Man A, we assessed the effects of Man A on phosphorylation of cytosolic phospholipase A(2) (cPLA(2)) and mitogen-activated protein kinases (MAPKs). Inhibition of LTC(4) generation by Man A was accompanied by a decrease in cPLA(2) phosphorylation, which occurred via the MAPKs including extracellular signal-regulated protein kinase-1/2 (ERK1/2) as well as p38 and c-Jun N-terminal kinase (JNK) pathways. Taken together, the present study suggests the Man A represents a potential therapeutic approach for the treatment of airway allergic-inflammatory diseases.

Topics: Animals; Anti-Inflammatory Agents; Arachidonate 5-Lipoxygenase; Bone Marrow; Dose-Response Relationship, Drug; Enzyme Activation; Inflammation; Leukotriene C4; Lignans; Male; Mast Cells; Mice; Mice, Inbred BALB C; Mitogen-Activated Protein Kinases; Phospholipases A2; Phosphorylation; Phytotherapy; Plant Extracts; Saururaceae

Increased levels of leukotrienes (LTs) in exhaled breath condensate (EBC) are associated with asthma and bronchial hyperresponsiveness (BHR), whereas eicosanoids generated through the 15-lipoxygenase (LO) pathway (15-hydroxyeicosatetraenoic acid [HETE] and eoxins) have been less studied.. We investigated whether metabolites of the 5- and 15-LO pathways in EBC are associated with childhood asthma, asthma severity, and clinical parameters.. The present study included 131 school-aged children (27 children with problematic severe asthma, 80 children with mild-to-moderate asthma, and 24 healthy children) from the Severe Asthma Recognized in Childhood study and 19 children with other nonasthmatic chronic lung diseases. Clinical work-up included spirometry, fractional exhaled nitric oxide measurements, skin prick testing, and methacholine challenge. Eicosanoids were analyzed in EBC by using mass spectrometry and are reported as concentrations (in picograms per milliliter) and eicosanoid/palmitic acid (PA) ratios.. Eoxin C₄/PA, eoxin D₄/PA, eoxin E₄/PA, 15-HETE/PA, and LTC₄/PA ratios were significantly increased in asthmatic versus healthy children. Eoxin D₄/PA and LTE₄/PA ratios were also significantly higher in children with BHR. A nonsignificant trend was observed toward higher eoxin/PA ratios with increasing asthma severity. In contrast to asthma, children with chronic lung disease had the highest 15-HETE/PA, LTC₄/PA, LTE₄/PA, and LTB₄/PA ratios.. The results point to increased activity of the 15-LO inflammatory pathway in childhood asthma. Mass spectrometric analyses of EBC demonstrate that increased eoxin levels not only accompany the increased 5-LO product LTC₄ but are also associated with BHR. These markers might represent a new therapeutic target for asthma treatment.

Topics: Adolescent; Arachidonate 15-Lipoxygenase; Asthma; Breath Tests; Bronchial Hyperreactivity; Child; Exhalation; Female; Humans; Hydroxyeicosatetraenoic Acids; Inflammation; Leukotriene C4; Leukotriene E4; Leukotrienes; Male; Mass Spectrometry; Severity of Illness Index

To investigate the sensitizing effects of the cysteinyl leukotrienes (CysLTs) C(4) and D(4) on the proinflammatory responses of chemoattractant-activated human neutrophils in vitro.. Neutrophils were isolated from venous blood taken from healthy, adult, human volunteers.. Cells were exposed to LTC(4) and LTD(4) (50-300 nM) prior to activation with 1 microM of N-formyl-L-methionyl- L-leucyl-L-phenylalanine (fMLF).. A fura-2/AM-based spectrofluorimetric procedure, lucigenin-enhanced chemiluminescence (LECL), a colourimetric method and an ELISA procedure, were used to measure Ca(2+) mobilization, superoxide production, elastase and MMP-8 release respectively following activation of LTC(4)/ D(4)-primed neutrophils with fMLF. Superoxide generation was also measured in the presence and absence of the CysLT receptor 1 antagonist, montelukast (100 nM).. Exposure of neutrophils to either LTC(4) or LTD(4) alone had modest effects on Ca(2+) mobilization, while superoxide generation and elastase release were unaffected. However, relative to the responses of neutrophils activated with fMLF in the absence of the CysLTs, pre-treatment of the cells with either LTC(4)or LTD(4) resulted in significant, augmentation of fMLF-activated elastase and MMP-8 release and superoxide generation, which was attenuated by montelukast.. These previously undocumented sensitizing interactions of LTs C(4) and D(4) with neutrophils may contribute to the activation of these cells in acute and chronic inflammation of both atopic and non-atopic aetiology, while identifying a role for montelukast in regulating neutrophil reactivity.

Topics: Acetates; Adult; Chemotactic Factors; Cyclopropanes; Fluorescent Dyes; Fura-2; Humans; Inflammation; Leukotriene Antagonists; Leukotriene C4; Leukotriene D4; Matrix Metalloproteinase 8; N-Formylmethionine Leucyl-Phenylalanine; Neutrophils; Pancreatic Elastase; Quinolines; Sulfides; Superoxides

Lipoxins represent a group of lipoxygenase derived eicosanoids which, in contrast to leukotrienes, are potent anti-inflammatory mediators. The aim of our study was to determine lipoxin A(4) (LXA(4)) and leukotriene C(4) (LTC(4)) levels in nasal lavages after intranasal challenge with aspirin in aspirin intolerant (AIA) in comparison to aspirin tolerant (ATA) asthmatics and after allergen challenge in patients suffering from allergic rhinitis.. Twelve AIA, 8 ATA and 20 allergic patients were challenged with placebo, 16 mg of lysine-aspirin (Lys-ASA) or allergen (grasses). Nasal lavages were collected and eicosanoids' levels were determined using ELISA.. Clinically positive Lys-ASA challenge in AIA resulted in influx of leukocytes (eosinophils and basophils) to nasal secretions and increase of LTC(4) to 106.82 pg/ml (P < 0.05 vs baseline (26.58 pg/ml)) on first hour after the challenge. We did not observe any differences in LTC(4) level before and after ASA challenge in ATA. In AIA group the mean level of LXA(4) was 43 +/- 21.5 pg/ml after placebo and decreased in 2 h after Lys-ASA challenge (29 +/- 17 pg/ml, P = 0.015). We found an increase in LXA(4) in ATA after ASA provocation as compared to placebo (33 +/- 16 pg/ml vs 52 +/- 31 pg/ml, P = 0.046). In atopic patients baseline level of LXA(4) was 33.49 +/- 16.95 pg/ml with no difference after the clinically positive allergen challenge (36.22 +/- 13.26 pg/ml, P = 0.23).. Results of our study confirm that AIA have diminished LXs' biosynthesis capacities in vivo after ASA challenge. Taking into consideration anti-inflammatory properties of lipoxins this phenomenon may be partially responsible for the development of chronic inflammation in AIA patients.

Topics: Adult; Allergens; Anti-Inflammatory Agents, Non-Steroidal; Aspirin; Case-Control Studies; Drug Tolerance; Enzyme-Linked Immunosorbent Assay; Humans; Inflammation; Leukotriene C4; Lipoxins; Lysine; Middle Aged; Nasal Provocation Tests; Poaceae

Cysteinyl-leukotrienes are involved in inflammation and act on at least two G-protein-coupled receptors, CysLT1 and CysLT2. However, the role of the CysLT2 receptor as well as its signaling remain poorly understood. Here we show that leukotriene (LT)C(4) induced the production of the chemokine interleukin (IL)-8 in endothelial cells. To further study the signaling cascade involved, HEK293 cells were stably transfected with CysLT2 and used to study the transcriptional regulation of the IL-8 promoter. Stimulation of the cells with increasing concentrations of LTC(4) resulted in a time- and concentration-dependent induction of IL-8 transcription and protein synthesis. Use of IL-8 promoter mutants with substitutions in their NF-kappaB, AP-1, or NF-IL-6 binding elements revealed an almost total requirement for NF-kappaB and AP-1 elements, and a lesser requirement for the NF-IL-6 element. Overexpression of dominant-negative IkappaBalpha prevented the IL-8 transactivation induced by LTC(4). LTC(4) stimulation induced NF-kappaB and AP-1 DNA binding, which involved the formation of a p50/p65 and a c-JUN.c-FOS complex, respectively. Transfection of the cells with a dominant negative (dn) form of PKCepsilon prevented p65 phosphorylation, whereas dnPKCdelta prevented AP-1 binding. Moreover, dnPKCdelta, dnPKCepsilon, and dnPKCzeta prevented LTC(4)-induced IL-8 transcription in response to LTC(4). Our data show for the first time that LTC(4) can act via the CysLT2 receptor to transcriptionally activate chemokine production through induction of NF-kappaB and AP-1 transcription factors. These findings suggest the potential implication of CysLT2 in the inflammatory response through the modulation of chemokine gene transcription.

Topics: Cell Line; Genes, fos; Humans; I-kappa B Kinase; Inflammation; Interleukin-8; Leukotriene C4; Membrane Proteins; NF-kappa B p50 Subunit; Protein Kinase C-delta; Protein Kinase C-epsilon; Proto-Oncogene Proteins c-jun; Receptors, Leukotriene; Response Elements; Signal Transduction; Transcription Factor RelA; Transcription, Genetic

Leukotriene A(4) hydrolase (LTA(4)H) catalyzes production of the proinflammatory lipid mediator, leukotriene (LT) B(4), which is implicated in a number of inflammatory diseases. We have identified a potent and selective inhibitor of both the epoxide hydrolase and aminopeptidase activities of recombinant human LTA(4)H (IC(50), approximately 10 nM). In a murine model of arachidonic acid-induced ear inflammation, the LTA(4)H inhibitor, JNJ-26993135 (1-[4-(benzothiazol-2-yloxy)-benzyl]-piperidine-4-carboxylic acid), dose-dependently inhibited ex vivo LTB(4) production in blood, in parallel with dose-dependent inhibition of neutrophil influx (ED(50), 1-3 mg/kg) and ear edema. In murine whole blood and in zymosan-induced peritonitis, JNJ-26993135 selectively inhibited LTB(4) production, without affecting cysteinyl leukotriene production, while maintaining or increasing production of the anti-inflammatory mediator, lipoxin (LX) A(4). The 5-lipoxygenase (5-LO) inhibitor zileuton showed inhibition of LTB(4), LTC(4), and LXA(4) production. Although zileuton inhibited LTB(4) production in the peritonitis model more effectively than the LTA(4)H inhibitor, the influx of neutrophils into the peritoneum after 1 and 2 h was significantly higher in zileuton- versus JNJ-26993135-treated animals. This difference may have been mediated by the increased LXA(4) levels in the presence of the LTA(4)H inhibitor. The selective inhibition of LTB(4) production by JNJ-26993135, while increasing levels of the anti-inflammatory mediator, LXA(4), may translate to superior therapeutic efficacy versus 5-LO or 5-LO-activating protein inhibitors in LTB(4)-mediated inflammatory diseases.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Arachidonic Acid; Ascitic Fluid; Benzothiazoles; Dogs; Ear; Edema; Eicosanoids; Enzyme Inhibitors; Epoxide Hydrolases; Female; Humans; Hydroxyurea; Inflammation; Leukotriene B4; Leukotriene C4; Lipoxins; Lipoxygenase Inhibitors; Mice; Mice, Inbred BALB C; Mice, Inbred Strains; Neutrophil Infiltration; Peritonitis; Piperidines; Recombinant Proteins

Human bronchial epithelial cells synthesize cyclooxygenase and 15-lipoxygenase products, but the 5-lipoxygenase (5-LO) pathway that generates the leukotriene (LT) family of bronchoconstrictor and pro-inflammatory mediators is thought to be restricted to leucocytes.. We hypothesized that human bronchial epithelial cells (HBECs) express a complete and active 5-LO pathway for the synthesis of LTB4 and LTC4, either constitutively or after stimulation.. Flow cytometry, RT-PCR, Western blotting, enzyme immunoassays and reverse-phase high-performance liquid chromatography were used to investigate constitutive and stimulated expression of 5-LO pathway enzymes and the synthesis of LTs B4 and C4 in primary HBECs and in the 16-HBE 14o- cell line.. Constitutive mRNA and protein expression for 5-LO, 5-LO-activating protein (FLAP), LTA4 hydrolase and LTC4 synthase were demonstrated in primary HBECs and in the 16-HBE 14o- cell line. In 16-HBE 14o- cells, treatment with calcium ionophore A23187, bradykinin or LPS up-regulated the expression of these enzymes. The up-regulation of 5-LO was blocked by the anti-inflammatory glucocorticoid dexamethasone. Human bronchial epithelial cells were shown to generate bioactive LTs, with primary HBECs generating 11-fold more LTC4 and five-fold more LTB4 than 16-HBE 14o- cells. LT production was enhanced by ionophore treatment and blocked by the FLAP inhibitor MK-886.. Expression of an active and inducible 5-LO pathway in HBEC suggests that damaged or inflamed bronchial epithelium may synthesize LTs that contribute directly to bronchoconstriction and leucocytosis in airway inflammation.

Topics: 5-Lipoxygenase-Activating Proteins; Arachidonate 15-Lipoxygenase; Arachidonate 5-Lipoxygenase; Bradykinin; Bronchi; Bronchoconstriction; Bronchoconstrictor Agents; Calcimycin; Carrier Proteins; Cell Line; Epithelial Cells; Gene Expression Regulation, Enzymologic; Glutathione Transferase; Humans; Inflammation; Inflammation Mediators; Ionophores; Leukotriene B4; Leukotriene C4; Lipopolysaccharides; Membrane Proteins; Prostaglandin-Endoperoxide Synthases; RNA, Messenger; Up-Regulation; Vasodilator Agents

The mechanisms by which secretory phospholipase A2 (PLA2) exerts cellular effects are not fully understood. To elucidate these mechanisms, we systematically and quantitatively assessed the activities of human group IIA, V, and X PLA2s on originating and neighboring cells using orthogonal fluorogenic substrates in various mixed cell systems. When HEK293 cells stably expressing each of these PLA2s were mixed with non-transfected HEK293 cells, group V and X PLA2s showed strong transcellular lipolytic activity, whereas group IIA PLA2 exhibited much lower transcellular activity. The transcellular activity of group V PLA2 was highly dependent on the presence of cell surface heparan sulfate proteoglycans of acceptor cells. Activation of RBL-2H3 and DLD-1 cells that express endogenous group V PLA2 led to the secretion of group V PLA2 and its transcellular action on neighboring human neutrophils and eosinophils, respectively. Similarly, activation of human bronchial epithelial cells, BEAS-2B, caused large increases in arachidonic acid and leukotriene C4 release from neighboring human eosinophils. Collectively, these studies show that group V and X PLA2s can act transcellularly on mammalian cells and suggest that group V PLA2 released from neighboring cells may function in triggering the activation of inflammatory cells under physiological conditions.

Topics: Animals; Arachidonic Acid; Blotting, Western; Brain; Cell Line; Cell Line, Tumor; Cell Membrane; DNA, Complementary; Eicosanoids; Eosinophils; Epithelium; Group II Phospholipases A2; Heparan Sulfate Proteoglycans; Heparin Lyase; Humans; Inflammation; Leukotriene C4; Microscopy, Confocal; Models, Chemical; Neutrophils; Phospholipases A; Phospholipases A2; Phospholipids; Protein Isoforms; Rats; Spectrometry, Fluorescence; Time Factors; Transfection

Histamine, leukotriene C4, IL-4, and IL-13 are major mediators of allergy and asthma. They are all formed by basophils and are released in particularly large quantities after stimulation with IL-3. Here we show that supernatants of activated mast cells or IL-3 qualitatively change the makeup of granules of human basophils by inducing de novo synthesis of granzyme B (GzmB), without induction of other granule proteins expressed by cytotoxic lymphocytes (granzyme A, perforin). This bioactivity of IL-3 is not shared by other cytokines known to regulate the function of basophils or lymphocytes. The IL-3 effect is restricted to basophil granulocytes as no constitutive or inducible expression of GzmB is detected in eosinophils or neutrophils. GzmB is induced within 6 to 24 hours, sorted into the granule compartment, and released by exocytosis upon IgE-dependent and -independent activation. In vitro, there is a close parallelism between GzmB, IL-13, and leukotriene C4 production. In vivo, granzyme B, but not the lymphoid granule marker granzyme A, is released 18 hours after allergen challenge of asthmatic patients in strong correlation with interleukin-13. Our study demonstrates an unexpected plasticity of the granule composition of mature basophils and suggests a role of granzyme B as a novel mediator of allergic diseases.

Topics: Antibodies, Monoclonal; Asthma; Basophils; Bronchoalveolar Lavage; Complement C5a; Granzymes; Humans; Inflammation; Interleukin-13; Interleukin-3; Killer Cells, Natural; Leukotriene C4; Mast Cells; Serine Endopeptidases; T-Lymphocytes, Cytotoxic

CCL28 is a recently identified chemokine ligand for CCR10 and CCR3 that has been identified in mucosal epithelial surfaces in diverse tissues. CCL28-mediated eosinophil chemotaxis and peroxidase release were inhibited by preincubation of cells with anti-CCR3. CCL28 was constitutively expressed in lung tissue collected from nonsensitized control mice but increased levels were found in mice sensitized and rechallenged with cockroach antigen (CRA). CCL28 levels peaked in the lungs 24 hours after intratracheal challenge with CRA, whereas eotaxin expression peaked at 8 hours. Increased expression of CCR3 but not CCR10 could be detected during the induction of the CRA-induced pulmonary inflammation. To investigate the role of CCL28 in allergic airway responses, mice were treated with CCL28 antiserum 1 hour before receiving the final CRA challenge. The level of airway hyperresponsiveness in mice treated with anti-CCL28 was significantly reduced at 24 hours, but not 8 hours, compared to mice receiving control serum. This reduction was not related to decreased Th2 cytokine, chemokine, or leukotriene levels at 24 hours although peribronchial eosinophilia was significantly reduced. Thus, CCL28 appears to play a role in regulating eosinophil recruitment to peribronchial regions of the lung possibly by coordinated temporal production with eotaxin.

Topics: Animals; Bronchial Hyperreactivity; Chemokine CCL11; Chemokines; Chemokines, CC; Chemotaxis; Dose-Response Relationship, Drug; Enzyme-Linked Immunosorbent Assay; Eosinophils; Gene Expression Regulation; Immunohistochemistry; Inflammation; Leukotriene C4; Leukotrienes; Ligands; Lung; Mice; Mice, Inbred CBA; Peroxidases; Receptors, CCR10; Receptors, CCR3; Receptors, Chemokine; RNA; Th2 Cells; Time Factors

Mast cells play pivotal roles in immediate-type and inflammatory allergic and nonallergic reactions. Cross-linking of the high-affinity receptor for IgE (FcepsilonRI) on mast cells activates a signaling pathway leading to Ca2+ mobilization and is followed by degranulation and the release of histamine and other preformed mediators, as well as de novo synthesis of arachidonic acid metabolites. In a previous study, we have demonstrated that heat shock activates heat shock transcription factor-1 (HSF-1), induces heat shock protein 70 (HSP70), and suppresses cytokine production in bone marrow-derived mast cells (BMMC). In this study, we further investigated the effects of heat shock on the activation of mast cells and the release of mast cell mediators.. In mouse mast cells, derived from a culture of bone marrow cells of male BALB/cBy and null HSF-1(-/-)mice, responsiveness to heat shock was monitored by measuring beta-hexosaminidase and leukotriene C4 (LTC4) release.. Using BMMC, we found that heat shock inhibits degranulation of BMMC without affecting leukotriene production. To further elucidate the mechanism of suppression of degranulation, we studied the effects of heat shock on the regulation of signal transduction in more detail. We found that heat shock inhibits calcium mobilization and tyrosine phosphorylation of Syk and SHIP upon IgE receptor activation, but increases the phosphorylation of SHP-1 and -2. Moreover, our results revealed that suppression of tyrosine phosphorylation of Syk and SHIP coincided with an increased tyrosine phosphatase activity.. The inhibitory action of heat shock toward mast cell degranulation is likely due to shifting the balance between kinase and phosphatase activity.

Topics: Animals; Calcium Signaling; Cell Degranulation; Cells, Cultured; DNA-Binding Proteins; Enzyme Precursors; Heat Shock Transcription Factors; Histamine; Histamine Release; Hot Temperature; Hypersensitivity; Inflammation; Intracellular Signaling Peptides and Proteins; Leukotriene C4; Male; Mast Cells; Mice; Mice, Inbred BALB C; Mice, Knockout; Phosphatidylinositol-3,4,5-Trisphosphate 5-Phosphatases; Phosphoric Monoester Hydrolases; Phosphorylation; Protein Tyrosine Phosphatases; Protein-Tyrosine Kinases; Receptors, IgE; Syk Kinase; Transcription Factors

Mast cells play a central role in immediate type hypersensitivity and inflammatory events. Activation of mast cells not only can result in the release of preformed granule-associated mediators generally followed by de novo synthesis of lipid-derived substances. In the present study, we show that mast cell can be activated to release lipid mediators in absence of granule exocytosis. Primary cultured murine mast cells were stimulated with substance P and produced leukotriene C4, and prostaglandin D2 without the release of the granule-associated enzyme beta-hexosaminidase. Indomethacin and nordihydroguaiaretic acid caused complete inhibition of arachidonic metabolite generation. Leukotriene C4 and prostaglandin D2 production was blocked by genistein, a specific inhibitor of tyrosine kinases, and bisindolylmaleimide, a protein kinase C inhibitor, indicating a role for both phosphorylation pathways in the substance P-stimulated lipid mediator production. We suggest that the cytokine microenvironment of the mast cell determines whether mast cell stimulation leads to only lipid mediator release or full activation. Analysis of granule-associated mediators only might underestimate the role of mast cell activation under (patho)physiological conditions.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Bone Marrow Cells; Cross-Linking Reagents; Cyclooxygenase Inhibitors; Cytoplasmic Granules; Enzyme Inhibitors; Exocytosis; Genistein; Immunoglobulin E; Indoles; Indomethacin; Inflammation; Leukotriene C4; Lipids; Maleimides; Masoprocol; Mast Cells; Mice; Mice, Inbred BALB C; Prostaglandin D2; Signal Transduction; Stimulation, Chemical; Substance P

Mast cells generate eicosanoids that are linked to asthma and other inflammatory diseases. A basic-helix-loop-helix leucine zipper transcription factor termed MITF is essential for the development of mast cells. Although other substances also linked to inflammatory reactions (such as various proteases and serotonin) require MITF for their expression, the role of MITF in eicosanoid generation has not been studied. We examined eicosanoid generation in bone marrow-derived mast cells (BMMCs) of tg/tg mice that lack MITF. Most eicosanoids generated by BMMCs are either prostaglandin (PG) D2 or leukotriene C4. The former is synthesized via the cyclooxygenase pathway, whereas the latter is synthesized via the 5-lipoxygenase pathway. In response to stimulation with IgE and antigens, BMMCs of tg/tg mice synthesized leukotriene C4 normally. However, neither immediate nor delayed PGD2 production was detected in these BMMCs. This indicates that MITF is a transcription factor that specifically activates the cyclooxygenase pathway, but not the 5-lipoxygenase pathway. Significant decreases in expression of hematopoietic PGD2 synthase (hPGDS, a terminal synthase for PGD2) were observed at both mRNA and protein levels in tg/tg BMMCs. MITF transactivated the hPGDS gene via a CACCTG motif located in the promoter region. MITF appeared to be essential for generation of PGD2 by enhancing expression of the hPGDS gene in BMMCs.

Topics: Amino Acid Motifs; Animals; Antigens; Arachidonate 5-Lipoxygenase; beta-N-Acetylhexosaminidases; Bone Marrow Cells; Cell Nucleus; Cells, Cultured; Cyclooxygenase 1; Cyclooxygenase 2; DNA-Binding Proteins; Dose-Response Relationship, Drug; Eicosanoids; Escherichia coli; Female; Immunoblotting; Immunoglobulin E; Inflammation; Intramolecular Oxidoreductases; Isoenzymes; Leukotriene C4; Lipocalins; Luciferases; Male; Mast Cells; Membrane Proteins; Mice; Mice, Transgenic; Microphthalmia-Associated Transcription Factor; Models, Genetic; Promoter Regions, Genetic; Prostaglandin D2; Prostaglandin-Endoperoxide Synthases; ras Guanine Nucleotide Exchange Factors; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Time Factors; Transcription Factors; Transcription, Genetic; Transcriptional Activation

Inhalation of heparin attenuates hyperventilation-induced bronchoconstriction in humans and dogs. The purpose of this study was to determine whether heparin inhibits the late-phase response to hyperventilation, which is characterized by increased peripheral airway resistance (RP), eicosanoid mediator production, neutrophilic/ eosinophilic inflammation, and airway hyperreactivity (AHR) at 5 h after dry air challenge (DAC). Fiberoptic bronchoscopy was used to record RP and airway reactivity (DeltaRP) to aerosol and intravenous histamine before and 5 h after DAC. Bronchoalveolar lavage fluid (BALF) cells and eicosanoid mediators were also measured approximately 5 h after DAC. DAC of vehicle-treated bronchi resulted in late-phase airway obstruction (approximately 120% increase over baseline RP), inflammation, increased BALF concentrations of leukotriene (LT) C(4), LTD(4), and LTE(4) and prostaglandin (PG)D(2), and AHR. Pretreatment with aerosolized heparin attenuated late-phase airway obstruction by approximately 50%, inhibited eosinophil infiltration, reduced BALF concentrations of LTC(4), LTD(4), and LTE(4) and PGD(2), and abolished AHR. We conclude that heparin inhibits hyperventilation-induced late-phase changes in peripheral airway function, and does so in part via the inhibition of eosinophil migration and eicosanoid mediator production and release.

Topics: Administration, Inhalation; Airway Resistance; Animals; Bronchial Hyperreactivity; Bronchial Provocation Tests; Bronchoalveolar Lavage Fluid; Bronchoscopy; Disease Models, Animal; Dogs; Drug Evaluation, Preclinical; Eicosanoids; Eosinophils; Heparin; Humans; Hyperventilation; Inflammation; Leukotriene C4; Leukotriene D4; Leukotriene E4; Male; Neutrophils; Prostaglandin D2; Time Factors

Four sesquiterpenes isolated from Jasonia glutinosa D.C. (Asteraceae), namely lucinone, glutinone, 5-epi-kutdtriol and kutdtriol, have been evaluated for their in vitro anti-inflammatory activity in cellular systems generating cyclooxygenase (COX) and 5-lipoxygenase (5-LOX) metabolites. None of the compounds assayed had a significant effect on leukotriene C4 (LTC4)-release from calcium ionophore-stimulated mouse peritoneal cells. However, the release of prostaglandin E2 (PGE2) by mouse peritoneal cells stimulated with calcium ionophore was inhibited by these compounds, although with less potency than the reference drug indomethacin (IC50=0.24 microM). The IC50 values of the active compounds were: lucinone 42.69 microM, glutinone 3.61 microM, 5-epi-kutdtriol 1.28 microM and kutdtriol 39 microM. Of the tested compounds, only glutinone (IC50=24 microM) showed a significant effect on thromboxane B2 (TXB2)-release induced by calcium ionophore in human platelets, although with less potency than the reference drug ibuprofen (IC50=1.27 microM).

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Asteraceae; Blood Platelets; Calcimycin; Cell Survival; Cyclooxygenase 1; Cyclooxygenase Inhibitors; Dinoprostone; Humans; In Vitro Techniques; Inflammation; Isoenzymes; Leukotriene C4; Lipoxygenase Inhibitors; Membrane Proteins; Mice; Peritoneal Cavity; Plant Leaves; Plants, Medicinal; Prostaglandin-Endoperoxide Synthases; Sesquiterpenes; Thromboxane B2

Leukocyte rolling is recognized as an important event in facilitating the extravasation of leukocytes from the vascular to the interstitial compartment, and is mediated by the selectin family of cell adhesion molecules. The aim of this study was to evaluate and characterize the rolling behavior of leukocytes in a model of acute inflammation using a novel soluble selectin ligand directed against P-selectin.. Feline mesenteric postcapillary venules were visualized using intravital microscopy prior to and following exposure to leukotriene C4 (LTC4) in animals pretreated with vehicle (saline) and the P-selectin antagonist rPSGL-Ig.. A concentration of 500 pM LTC4 induced a threefold and sixfold elevation in leukocyte rolling flux and adhesion, respectively, compared to baseline values (p < 0.05). Administration of rPSGL-Ig had no effect on LTC4-induced leukocyte rolling flux but significantly attenuated the increase in the fraction of rolling leukocytes (p < 0.05). In addition, rPSGL-Ig inhibited the LTC4-induced reductions in leukocyte rolling velocity (p < 0.001). Finally, LTC4-induced leukocyte adhesion in animals pretreated with rPSGL-Ig was reduced by 60%, compared to vehicle-treated animals (p < 0.05).. LTC4 induces leukocyte rolling and adhesion in feline mesenteric venules in a dose-dependent manner. Administration of rPSGL-Ig inhibits LTC4-induced reductions in leukocyte rolling velocity and attenuates the elevation in the fraction of rolling leukocytes produced by LTC4 stimulation. This suggests that rPSGL-Ig may be used to reduce leukocyte rolling and adhesion, and subsequently attenuate tissue injury during inflammation.

Topics: Amino Acid Sequence; Animals; Cats; Cell Adhesion; Cell Movement; Disease Models, Animal; Humans; Inflammation; Leukocytes; Leukotriene C4; Male; Membrane Glycoproteins; Mesenteric Veins; Molecular Sequence Data; P-Selectin; Phlebitis; Recombinant Proteins; Solubility; Venules

The pentacyclic triterpene lupeol has been studied for its inhibitory effects on murine models of inflammation and peritoneal macrophage functions in-vitro. Lupeol (0.5 and 1 mg/ear) administered topically suppressed the mouse ear oedema induced by 12-0-tetradecanoyl-phorbol acetate (TPA), being less effective on ear oedema induced by arachidonic acid. Quantitation of the neutrophil specific marker myeloperoxidase demonstrated that its topical activity was associated with reduction in cell infiltration into inflamed tissues. When tested in-vitro, lupeol significantly reduced prostaglandin E2 (PGE2) production from A23187-stimulated macrophages, but failed to affect leukotriene C4 release. It was a weak inhibitor of nitrite release, but dose-dependently suppressed PGE2. Cytokine production (tumour necrosis factor-alpha and interleukin-1beta) was inhibited in the range 10-100 microM in lipopolysaccharide-treated macrophages. This study demonstrated that lupeol possessed anti-inflammatory activity which was likely to depend on its ability to prevent the production of some pro-inflammatory mediators.

Topics: Animals; Anti-Inflammatory Agents; Arachidonic Acid; Cytokines; Dinoprostone; Dose-Response Relationship, Drug; Edema; Inflammation; Interleukin-1; Leukotriene C4; Macrophages, Peritoneal; Male; Mice; Models, Animal; Nitrites; Pentacyclic Triterpenes; Phytotherapy; Pimenta; Plant Extracts; Tetradecanoylphorbol Acetate; Triterpenes; Tumor Necrosis Factor-alpha

Leukotrienes (LT) are potent lipid mediators synthesized by the 5-lipoxygenase pathway of arachidonic acid (AA) metabolism. LT have been implicated in a broad spectrum of inflammatory processes. To investigate the influence of genetic factors on the contribution of LT to acute inflammation, we generated congenic 5-lipoxygenase-deficient 129, C57BL/6 (B6), and DBA/1Lac (DBA) mouse lines. Topical application of AA evoked a vigorous inflammatory response in 129 and DBA mice, whereas only a modest response was seen in B6 animals. The response to AA in 129 and DBA strains is LT dependent. In contrast, LT make little contribution to this response in B6 mice. AA-induced inflammation in B6 mice is prostanoid dependent, since this response was substantially reduced by treating B6 mice with a cyclooxygenase inhibitor. These data suggest that prostanoids are essential for AA-induced cutaneous inflammation in B6 mice, whereas LT are the major mediators of this response in 129 and DBA strains. In contrast, the response to AA in the peritoneal cavity is robust in the 129 and B6 strains, but was significantly blunted in DBA mice, showing that strain differences in the response to AA are tissue specific. Variations in these and other experimental models of inflammation appear to correlate directly with the ability of a particular mouse strain and a specific tissue to respond to LT, specifically LTC4. Taken together, these findings indicate that the relative contribution of prostanoids and LT to inflammatory responses is variable not only between strains but also between different tissues within these inbred mouse lines.

Topics: Acute Disease; Animals; Arachidonate 5-Lipoxygenase; Arachidonic Acid; Crosses, Genetic; Ear, External; Edema; Indomethacin; Inflammation; Leukotriene C4; Leukotrienes; Mice; Mice, Congenic; Mice, Inbred C57BL; Mice, Inbred DBA; Mice, Mutant Strains; Peritonitis; Species Specificity; Zymosan

Apoptosis in vivo is followed almost inevitably by rapid uptake into adjacent phagocytic cells, a critical process in tissue remodeling, regulation of the immune response, or resolution of inflammation. Phagocytosis of apoptotic cells by macrophages has been suggested to be a quiet process that does not lead to production of inflammatory mediators. Here we show that phagocytosis of apoptotic neutrophils (in contrast to immunoglobulin G-opsonized apoptotic cells) actively inhibited the production of interleukin (IL)-1beta, IL-8, IL-10, granulocyte macrophage colony-stimulating factor, and tumor necrosis factor-alpha, as well as leukotriene C4 and thromboxane B2, by human monocyte-derived macrophages. In contrast, production of transforming growth factor (TGF)-beta1, prostaglandin E2, and platelet-activating factor (PAF) was increased. The latter appeared to be involved in the inhibition of proinflammatory cytokine production because addition of exogenous TGF-beta1, prostaglandin E2, or PAF resulted in inhibition of lipopolysaccharide-stimulated cytokine production. Furthermore, anti-TGF-beta antibody, indomethacin, or PAF receptor antagonists restored cytokine production in lipopolysaccharide-stimulated macrophages that had phagocytosed apoptotic cells. These results suggest that binding and/or phagocytosis of apoptotic cells induces active antiinflammatory or suppressive properties in human macrophages. Therefore, it is likely that resolution of inflammation depends not only on the removal of apoptotic cells but on active suppression of inflammatory mediator production. Disorders in either could result in chronic inflammatory diseases.

Topics: Apoptosis; Cytokines; Dinoprostone; Humans; Inflammation; Jurkat Cells; Leukotriene C4; Macrophages; Neutrophils; Phagocytosis; Platelet Activating Factor; Solubility; Thromboxane B2; Transforming Growth Factor beta

Bleomycin and asparaginase are widely used antineoplastic agents which may induce allergic or inflammatory side-effects. Mast cells are implicated as effector cells in allergic and inflammatory responses. The aim of this study was to establish whether bleomycin or asparaginase modulate leukotriene production in vitro and in vivo. Leukotriene C4 (LTC4) production by murine bone marrow-derived mast cells (BMMC) was determined by radioimmunoassay (RIA). Leukotriene production in patients was assessed by determining leukotriene E4 and N-acetyl-leukotriene E4 in urine by means of combined HPLC and RIA. Bleomycin induced an up to 2.1-fold increase in LTC4 production both in unstimulated and in calcium ionophore-stimulated mast cells. In 3 of 7 patients treated with bleomycin, a greater than 2-fold increase in endogenous leukotriene production was observed. This effect was associated with febrile responses and was most pronounced in a patient who developed an Adult Respiratory Distress Syndrome (ARDS). Asparaginase increased leukotriene production up to 10-fold in stimulated but not in unstimulated BMMC. In a patient who developed an anaphylactic reaction after treatment with asparaginase, a pronounced increase in urinary leukotriene concentration was observed. In contrast to bleomycin or asparaginase, a number of other cytostatic agents did not significantly change leukotriene production by BMMC. Our data indicate that some of the inflammatory and allergic side-effects of bleomycin and asparaginase could be mediated by leukotrienes, a possible source of which may be mast cells.

Topics: Adult; Anaphylaxis; Animals; Antineoplastic Agents; Asparaginase; Bleomycin; Calcimycin; Drug Hypersensitivity; Humans; In Vitro Techniques; Inflammation; Ionophores; Leukotriene C4; Leukotriene E4; Leukotrienes; Lymphoma, Non-Hodgkin; Mast Cells; Mice; Mice, Inbred BALB C; Respiratory Distress Syndrome

Myrtol standardized (Gelomyrtol/Gelomyrtol forte) inhibits the activity of 5-lipoxygenase of human basophil and eosinophil leukocytes and the formation of leukotriene C4 as well as 1.8-cineole (eucalyptol). An increase of prostaglandins (PGE2) in mucous membranes of teat cisterns after topical administration of TPA (tetradecanoylphorbol-13-acetate) was inhibited. In vitro and in vivo studies revealed spasmolytic and broncholytic effects of Myrtol stand. After topical administration into the teat cisterns of the isolated bovine udder Myrtol stand. increased the surface temperature, comparable to effects of menthol.

Topics: Animals; Arachidonate 5-Lipoxygenase; Arachidonic Acid; Basophils; Cattle; Cyclohexanols; Dinoprostone; Drug Combinations; Drug Interactions; Eosinophils; Eucalyptol; Female; Guinea Pigs; Humans; Hyperemia; In Vitro Techniques; Inflammation; Leukemia, Basophilic, Acute; Leukotriene C4; Leukotriene D4; Leukotriene E4; Male; Mammary Glands, Animal; Menthol; Mice; Monoterpenes; Mucous Membrane; Muscle Contraction; Muscle, Smooth; Rats; Terpenes; Tetradecanoylphorbol Acetate; Trachea; Tumor Cells, Cultured

We have examined the synthesis of leukotriene C4 from bovine aortic and pulmonary artery endothelium. Under basal conditions, neither aortic nor pulmonary artery endothelium revealed significant amounts of hydroxy fatty acids. Following incubation with ionophore A23187, several peaks including one which co-migrated with authentic LTC4 could be demonstrated from both aortic and pulmonary endothelium. LTC4 production was maximal after 30 min incubation, was inhibitable by the lipoxygenase inhibitor nordihydroguairetic acid, and was synthesized by bovine endothelium from tritiated arachidonic acid substrate. The putative LTC4 from endothelium was shown to be identical to authentic LTC4 by chromatography and scanning UV spectroscopy. Endothelial-derived LTC4 increased the adherence of bovine aortic endothelium for neutrophils in a concentration dependent pattern similar to authentic LTC4. These data suggest that vascular endothelium may influence leukocyte-endothelial interactions through synthesis of biologically active arachidonic acid metabolites such as LTC4.

Topics: Animals; Arachidonic Acid; Calcimycin; Cattle; Cell Adhesion; Cells, Cultured; Chromatography, High Pressure Liquid; Endothelium, Vascular; Humans; Inflammation; Ionophores; Leukotriene C4; Neutrophils; Spectrophotometry

To investigate the effect of epithelial cells from respiratory mucosa on eosinophil activation.. Epithelial cell cultures were obtained from healthy nasal mucosa and nasal polyps. Eosinophils were isolated from peripheral blood and incubated with epithelial cell conditioned media (HECM) in the presence or absence of dexamethasone (10 microM). Eosinophil survival, expression of EG2 and CD69, and production of eosinophil cationic protein (ECP) and leukotriene C4 (LTC4) were evaluated. Cytokine levels in HECM were assessed by ELISA.. HECM induced eosinophil survival (78.6 +/- 9.9% for nasal mucosa, and 92.6 +/- 15% for nasal polyps) compared to controls (1 +/- 0.8%; p < 0.05). Dexamethasone blocked HECM induced eosinophil survival, this effect being greater when eosinophils were primed with nasal mucosa HECM. HECM promoted EG2 expression in eosinophils (47.9 +/- 9.1% for nasal mucosa, and 58.5 +/- 11.8% for nasal polyp) compared to controls (8.1 +/- 3.7%; p < 0.01). HECM had no effect on both CD69 expression and LTC4 release but decreased ECP secretion. Levels of interleukin (IL)-8 (35,700 +/- 7,300 pg/ml), IL-1 beta (11.3 +/- 1.8 pg/ml) and TNF-alpha (38.2 +/- 11 pg/ml) on nasal polyps HECM were significantly higher than on nasal mucosa HECM (17,600 +/- 2,700, 5.4 +/- 0.7 and 16.8 +/- 1.4 pg/ml, respectively; p < 0.05).. Epithelial cells from respiratory mucosa proved to have potential to increase eosinophil survival and activation. The lower inhibitory effect of dexamethasone on nasal polyps induced eosinophil survival and activation may be caused by a higher release of eosinophil activating factors from nasal polyp epithelial cells (inflammed tissue) compared to nasal mucosa.

Topics: Antigens, CD; Antigens, Differentiation, T-Lymphocyte; Blood Proteins; Cell Survival; Eosinophil Granule Proteins; Eosinophils; Epithelial Cells; Epithelium; Humans; Inflammation; Inflammation Mediators; Lectins, C-Type; Leukotriene C4; Nasal Mucosa; Ribonucleases

Topics: Animals; Eicosanoids; Enzyme Activation; Enzyme Inhibitors; Group II Phospholipases A2; Guanidines; Inflammation; Intestinal Mucosa; Isothiuronium; Leukotriene C4; Male; Models, Biological; Nitric Oxide; Nitric Oxide Synthase; Phospholipases A; Phospholipases A2; Platelet Activating Factor; Rats; Rats, Sprague-Dawley; Vasoconstriction

The multidrug resistance-associated protein (MRP) mediates the cellular excretion of many drugs, glutathione S-conjugates (GS-X) of lipophilic xenobiotics and endogenous cysteinyl leukotrienes. Increased MRP levels in tumor cells can cause multidrug resistance (MDR) by decreasing the intracellular drug concentration. The physiological role or roles of MRP remain ill-defined, however. We have generated MRP-deficient mice by using embryonic stem cell technology. Mice homozygous for the mrp mutant allele, mrp-/-, are viable and fertile, but their response to an inflammatory stimulus is impaired. We attribute this defect to a decreased secretion of leukotriene C4 (LTC4) from leukotriene-synthesizing cells. Moreover, the mrp-/- mice are hypersensitive to the anticancer drug etoposide. The phenotype of mrp-/- mice is consistent with a role for MRP as the main LTC4-exporter in leukotriene-synthesizing cells, and as an important drug exporter in drug-sensitive cells. Our results suggest that this ubiquitous GS-X pump is dispensable in mice, making treatment of MDR with MRP-specific reversal agents potentially feasible.

Topics: Adult; Animals; Antineoplastic Agents; Antineoplastic Agents, Phytogenic; ATP-Binding Cassette Transporters; Bone Marrow Cells; Carrier Proteins; Drug Resistance, Multiple; Drug Resistance, Neoplasm; Etoposide; Humans; Inflammation; Leukotriene C4; Membrane Transport Proteins; Mice; Mice, Knockout; Multidrug Resistance-Associated Proteins; Neoplasm Proteins; Neoplasms, Experimental; Tumor Cells, Cultured

Topics: Animals; Cattle; Cell Adhesion; Cells, Cultured; Endothelium, Vascular; Glomerular Mesangium; Glomerulonephritis; Humans; Hydroxyeicosatetraenoic Acids; Inflammation; Kidney Glomerulus; Leukotriene C4; Lipoxins; Neutrophils; Phagocytes

Idiopathic pulmonary fibrosis (IPF) is a progressive disorder characterized by inflammation, fibroblast proliferation, and accumulation of extracellular matrix proteins. Leukotrienes (LTs) are pro-inflammatory and pro-fibrogenic mediators derived from the 5-lipoxygenase (5-LO) pathway of arachidonic acid metabolism. They are thought to play a role in a number of disease processes, but have received relatively little attention in investigations into the pathogenesis of IPF. In this study, we measured the levels of immunoreactive LTs B(4) and C(4) in homogenates of lung tissue obtained from patients with newly diagnosed, untreated IPF, as compared to levels measured in homogenates of uninvolved nonfibrotic lung tissue from patients undergoing resectional surgery for bronchogenic carcinoma. Compared to homogenates on nonfibrotic control lung, homogenates from IPF patients contained 15-fold more LTB(4) and 5-fold more LTC(4). IPF homogenate levels of LTB(4) were significantly correlated with histologic indices of both inflammation (r=0.861) and fibrosis (r=0.926). Activation of 5-LO is known from in vitro studies to be associated with localization of the enzyme at the nuclear membrane. Immunohistochemical staining for 5-LO protein in alveolar macrophages (AMs) demonstrated that such an "activated" localization pattern was significantly more frequent in IPF lung (19.2+/-3.3% of cells) than in control lung (9.3+/-0.9%); this localization pattern was rarely seen (3.2%) in sections from a truly normal transplant donor lung. Consistent with these data, AMs obtained from IPF patients by bronchoalveolar lavage, purified by adherence, and cultured in the absence of a stimulus for 16 h elaborated significantly greater amounts of LTB(4) and LTC(4) than did control AMs obtained from normal volunteers. These data indicate that the 5-LO pathway is constitutively activated in the lungs of patients with IPF, and the AM represents at least one cellular source of LT overproduction in this disorder. We speculate that LTs participate in the pathogenesis of IPF, and their overproduction in this disorder may be amenable to specific pharmacotherapy.

Topics: Adult; Aged; Arachidonate 5-Lipoxygenase; Cells, Cultured; Enzyme Activation; Female; Humans; Immunohistochemistry; Inflammation; Leukotriene B4; Leukotriene C4; Lung; Lung Neoplasms; Macrophages, Alveolar; Male; Middle Aged; Pulmonary Fibrosis; Smoking

Inhalation of antigen in immunized mice induces an infiltration of eosinophils into the airways and increased bronchial hyperreactivity as are observed in human asthma. We employed a model of late-phase allergic pulmonary inflammation in mice to address the role of leukotrienes (LT) in mediating airway eosinophilia and hyperreactivity to methacholine. Allergen intranasal challenge in OVA-sensitized mice induced LTB4 and LTC4 release into the airspace, widespread mucus occlusion of the airways, leukocytic infiltration of the airway tissue and broncho-alveolar lavage fluid that was predominantly eosinophils, and bronchial hyperreactivity to methacholine. Specific inhibitors of 5-lipoxygenase and 5-lipoxygenase-activating protein (FLAP) blocked airway mucus release and infiltration by eosinophils indicating a key role for leukotrienes in these features of allergic pulmonary inflammation. The role of leukotrienes or eosinophils in mediating airway hyperresponsiveness to aeroallergen could not be established, however, in this murine model.

Topics: 5-Lipoxygenase-Activating Proteins; Allergens; Animals; Asthma; Bronchial Provocation Tests; Bronchoconstrictor Agents; Carrier Proteins; Disease Models, Animal; Female; Immunoglobulin E; Inflammation; Leukotriene B4; Leukotriene C4; Lipoxygenase Inhibitors; Membrane Proteins; Methacholine Chloride; Mice; Mice, Inbred BALB C; Mucus; Ovalbumin; Pulmonary Eosinophilia; Respiratory Function Tests; Respiratory System

To investigate whether modulation of the fatty acid profile can be achieved by the short-term infusion of a fish oil emulsion which may attenuate the pulmonary response to inflammatory stimulation. Changes of fatty acid pattern in-lung tissue and perfusate were analyzed and correlated with physiologic data after a 3-hr infusion of fish oil in comparison with a soybean oil preparation.. Prospective, randomized, controlled trial.. Experimental laboratory in a university teaching hospital.. Forty standard breed rabbits of either gender.. Isolated lungs from anesthetized rabbits were ventilated and recirculation-perfused (200 mL/min) with 200 mL of cell-free buffer solution to which either 2 mL of saline (control, n = 6), 2 mL of a 10% soybean oil preparation (n = 6), or 2 mL of a 10% fish oil emulsion (n = 6) were added. Samples of perfusate and lung tissue were collected for analysis of fatty acid composition. Tissue and perfusate fatty acid composition were analyzed by capillary gas chromatography. To study metabolic alterations in states of inflammatory stimulation, lungs of each group were stimulated with small doses of the calcium ionophore, A23187 (10(-8) M), during the 180-min lipid perfusion period and again after washing out the lipids by exchanging the perfusion fluid. Pulmonary arterial pressure and lung weight gain were monitored, and eicosanoids were analyzed in the perfusate.. Free eicosapentaenoic acids increased several-fold in lung tissue and perfusate during a 3-hr infusion with fish oil. The intravenously administered n-3 fatty acids were rapidly hydrolyzed, as indicated by the appearance of substantial quantities of eicosapentaenoic acid in the perfusate free fatty acid fraction. This increase of perfusion levels of eicosapentaenoic acid was paralleled by an attenuated pressure increase and edema formation due to calcium ionophore challenge and an altered eicosanoid spectrum determined in the perfusate compared with soybean oil-treated lungs.. Short-term n-3 lipid application (fish oil emulsion) exerts anti-inflammatory effects on lung vasculature, which may be due to the metabolism of eicosapentaenoic acid resulting in the generation of less potent inflammatory eicosanoids.

Topics: Animals; Calcimycin; Chromatography, High Pressure Liquid; Eicosapentaenoic Acid; Fatty Acids, Omega-3; Female; Fish Oils; Inflammation; Ionophores; Leukotriene C4; Lung; Male; Rabbits; SRS-A

The amyloidogenic peptides, amyloid-beta (A beta) and human amylin, are the major constituents of amyloid deposits found in patients with the chronic degenerative disorders Alzheimer's disease (AD) and type 2 diabetes, respectively. Recent studies have shown that a variety of inflammatory proteins such as cytokines are associated with the amyloid deposits of AD brain tissues. Therefore, in the present study, we sought to determine whether A beta and/or human amylin could modulate the various inflammatory activities of eosinophils. We observed that human amylin but not A beta peptides inhibited the in vitro interleukin-5 (IL-5)-mediated survival of cord blood-derived eosinophils (CBEs) in a concentration-dependent manner. By contrast, rat amylin, a nonamyloidogenic peptide that is highly homologous to human amylin, failed to affect the IL-5-mediated survival of CBEs. Similar inhibitory effects of human amylin were observed for peripheral blood eosinophils. Human amylin also enhanced the release of the cytokine granulocyte-macrophage colony-stimulating factor by CBEs that were stimulated with the calcium ionophore A23187 but was incapable of directly stimulating CBEs to release cytokines. In addition, the A23187-induced release of the inflammatory lipid mediator leukotriene C4 by CBEs was augmented by human amylin. These results suggest that the amyloidogenic peptide human amylin is capable of amplifying the various inflammatory activities of eosinophils.

Topics: Amyloid; Amyloid beta-Protein Precursor; Animals; Calcimycin; Cell Survival; Cells, Cultured; Eosinophils; Fetal Blood; Humans; Inflammation; Inflammation Mediators; Interleukin-5; Ionophores; Islet Amyloid Polypeptide; Leukotriene C4; Peptide Fragments; Rats

Topics: Animals; Arachidonate 5-Lipoxygenase; Arachidonic Acid; Bone Marrow Cells; Carrageenan; Dinoprostone; Female; Inflammation; Leukotriene C4; Leukotrienes; Macrophages; Male; Mast Cells; Mice; Mice, Inbred C57BL; Mice, Inbred Strains; Mice, Mutant Strains; Phagocytosis; Phenotype; Platelet Activating Factor; Spleen; Tetradecanoylphorbol Acetate

A quantitative determination of the inflammatory mediators was performed and correlated with complaints and the measurement of the inflammatory cells in nasal secretions of 18 seasonal allergic rhinitis patients (group 1) outside the pollen season and 40 symptomatic patients (group 2) with seasonal allergic rhinitis during the pollen season. Ten nonallergic subjects (group 3) were also studied as a normal control group. In group 1, 17 (94%) out of 18 patients had an immediate response of nasal symptoms accompanied by a significant increase of histamine, leukotriene C4 (LTC4), and tryptase 5 min after nasal allergen challenge (NAC). One hour later, a simultaneous increase was seen both in the percentage of the eosinophils and in the eosinophil cationic protein (ECP) concentration. The eosinophil count reached a peak 2 h after NAC with a duration of 8 h, while the highest ECP level was reached only after 24 h with no clear-cut plateau. In group 2, a high percentage of eosinophils was observed. Mostly one observed significantly (p < 0.01) higher concentrations of ECP, LTC4 and histamine but not of tryptase than the baseline values of group 1. The authors concluded that during the pollen season allergic rhinitis reflects mainly a chronic state of allergic inflammation of the nasal mucosa involving various inflammatory components induced by one or more episodes of early-phase type allergic reaction. Infiltration of eosinophils and consequently release of the various late-phase inflammatory mediators into the nasal secretions are certainly believed to be the predominant pathophysiologic condition in the patients.

Topics: Adolescent; Adult; Allergens; Blood Proteins; Chymases; Eosinophil Granule Proteins; Female; Histamine; Humans; Inflammation; Inflammation Mediators; Leukotriene C4; Male; Middle Aged; Nasal Mucosa; Nasal Provocation Tests; Rhinitis, Allergic, Seasonal; Ribonucleases; Serine Endopeptidases; Tryptases

Leukotrienes have been implicated in the regulation of immune responses, including inflammation and immediate hypersensitivity reactions. Here, we describe the phenotypic analysis of leukotriene-deficient mice generated by inactivation of the 5-lipoxygenase (5LO) gene. These 5LO(-/-) mice were unable to synthesize detectable levels of leukotrienes and were more resistant to lethal anaphylaxis induced by platelet-activating factor. The intensity of an acute inflammatory response induced by arachidonic acid was similar in 5LO(-/-) mice and controls. However, the response in 5LO(-/-) mice, but not in controls, could be virtually eliminated by a cyclooxygenase inhibitor. These data suggest that inflammatory responses are modulated by arachidonic acid metabolites through a variety of interconnected mechanisms. This has important implications for understanding the early events of an inflammatory response and for designing drugs for use in therapeutic intervention.

Topics: Anaphylaxis; Animals; Arachidonate 5-Lipoxygenase; Chemotaxis, Leukocyte; Dinoprostone; Edema; Inflammation; Leukotriene C4; Leukotrienes; Macrophages; Mice; Mice, Knockout; Neutrophils; Platelet Activating Factor; Thromboxane B2

Sickle cell (HbSS) disease is associated with rheological and inflammatory stresses within the microcirculation. In order to determine the role of leukotrienes in the inflammatory processes in HbSS patients, we analysed plasma and urine levels of leukotrienes (LT); LTB4, LTC4, LTD4, and LTE4 as indicators of their in vivo metabolism. Plasma and urine level samples of 15 HbSS patients in steady-state and age-matched healthy, homozygous (HbAA) controls were extracted for leukotrienes and quantitated by HPLC. Control plasma level of leukotrienes (mean +/- SEM, ng ml-1) were: LTB4, 8.95 +/- 0.26; LTC4, 7.24 +/- 0.21; LTD4, 11.42 +/- 0.40; and LTE4, 14.51 +/- 0.50. Corresponding values for HbSS patients were: LTB4, 6.15 +/- 0.42; LTC4, 13.61 +/- 1.45; LTD4, 6.44 +/- 0.51 and LTE4, 4.97 +/- 0.37. The differences were significant at P < 0.05. Urine levels (mean +/- SEM, ng mmol-1 creatinine), for controls were: LTB4, 10.60 +/- 0.35; LTC4, 360.0 +/- 9.82. Values for HbSS urine were: LTB4, 27.50 +/- 3.33; LTC4, 356.0 +/- 17.87; LTD4, 69.90 +/- 14.51. LTD4 was not detected in control urine. These results suggest that sickle cell patients may exhibit impaired ability to catabolize LTC4 in plasma during steady state conditions. This altered metabolism may contribute to the persistent stress of the microcirculation, and is probably related to the abnormal microvascular rheology of sickle blood cells.

Topics: Adult; Anemia, Sickle Cell; Cell Adhesion; Endothelium, Vascular; Female; Humans; Inflammation; Leukocytes; Leukotriene B4; Leukotriene C4; Leukotriene D4; Leukotriene E4; Leukotrienes; Male; Middle Aged

Anti-inflammatory activity of baicalein (5,6,7-trioxyflavone-7-O-beta-D-glucuronide) was greater in the chronic inflammation model (rat adjuvant arthritis, ED50 = 120.6 mg/kg) than observed in the rat carrageenan-induced paw edema, ED50 > or = 200.0 mg/kg. A comparative study of the 5-lipoxygenase (5-LO) inhibitory activity of baicalein, BW 755 C, and hydroxamic acid arachidonate on leukotriene C4 (LTC4) biosynthesis by rat resident peritoneal macrophages stimulated with calcium ionophore (A 23186) showed that these drugs significantly inhibited LTC4 production, IC50: 9.5, 41.8, and 2.8 microM, respectively. This finding suggests that inhibition of the 5-LO pathway of arachidonic acid metabolism may be one of the mechanisms of baicalein's anti-inflammatory activity.

Topics: 4,5-Dihydro-1-(3-(trifluoromethyl)phenyl)-1H-pyrazol-3-amine; Animals; Arachidonic Acids; Arthritis, Experimental; Carrageenan; Diclofenac; Edema; Flavanones; Flavonoids; Hydroxamic Acids; Inflammation; Leukotriene C4; Lipoxygenase Inhibitors; Macrophages, Peritoneal; Male; Rats; Rats, Wistar