leukotriene-b4 and Pneumonia

Topics: Humans; Immunity, Innate; Interleukin-8; Leukotriene B4; Macrophages, Alveolar; Pneumonia; Pulmonary Fibrosis

Topics: Anaphylatoxins; Arachidonic Acid; Arachidonic Acids; Asthma; Eicosanoic Acids; Fatty Acids; Humans; Leukocytes; Leukotriene B4; Lung; Macrophage Activation; Mucus; Platelet Activating Factor; Pneumonia; Prostaglandin-Endoperoxide Synthases; Respiratory Distress Syndrome; SRS-A

Inhaled lipopolysaccharide (LPS) induces a dose-dependent, acute neutrophilic response in the airways of healthy volunteers that can be quantified in induced sputum. Chemokines, such as CXCL1 and CXCL8, play an important role in neutrophilic inflammation in the lung through the activation of CXCR2 and small molecule antagonists of these receptors have now been developed. We investigated the effect of AZD8309, a CXCR2 antagonist, compared with placebo on LPS-induced inflammation measured in sputum of healthy volunteers.. Twenty healthy subjects were randomized in a double-blind placebo-controlled, cross-over study. AZD8309 (300 mg) or placebo was dosed twice daily orally for 3 days prior to challenge with inhaled LPS and induced sputum was collected 6 h later.. Treatment with AZD8309 showed a mean 77% reduction in total sputum cells (p < 0.001) and 79% reduction in sputum neutrophils (p < 0.05) compared with placebo after LPS challenge. There was also a reduction in neutrophil elastase activity (p < 0.05) and CXCL1 (p < 0.05) and trends for reductions in sputum macrophages (47%), leukotriene B4 (39%) and CXCL8 (52%).. AZD8309 inhibited LPS-induced inflammation measured in induced sputum of normal volunteers, indicating that this treatment may be useful in the treatment of neutrophilic diseases of the airways, such as COPD, severe asthma and cystic fibrosis.. NCT00860821.

Topics: Administration, Oral; Adult; Cell Count; Cross-Over Studies; Dose-Response Relationship, Drug; Double-Blind Method; Humans; Interleukin-8; Leukocyte Elastase; Leukotriene B4; Lipopolysaccharides; Male; Neutrophils; Pneumonia; Pyrimidines; Receptors, Interleukin-8B; Sputum

Administration of eicosapentaenoic acid and docosahexanoic acid, omega-3 fatty acids in fish oil, has been associated with improved patient outcomes in acute lung injury when studied in a commercial enteral formula. However, fish oil has not been tested independently in acute lung injury. We therefore sought to determine whether enteral fish oil alone would reduce pulmonary and systemic inflammation in patients with acute lung injury.. Phase II randomized controlled trial.. Five North American medical centers.. Mechanically ventilated patients with acute lung injury ≥18 yrs of age.. Subjects were randomized to receive enteral fish oil (9.75 g eicosapentaenoic acid and 6.75 g docosahexanoic acid daily) or saline placebo for up to 14 days.. Bronchoalveolar lavage fluid and blood were collected at baseline (day 0), day 4 ± 1, and day 8 ± 1. The primary end point was bronchoalveolar lavage fluid interleukin-8 levels. Forty-one participants received fish oil and 49 received placebo. Enteral fish oil administration was associated with increased serum eicosapentaenoic acid concentration (p < .0001). However, there was no significant difference in the change in bronchoalveolar lavage fluid interleukin-8 from baseline to day 4 (p = .37) or day 8 (p = .55) between treatment arms. There were no appreciable improvements in other bronchoalveolar lavage fluid or plasma biomarkers in the fish oil group compared with the control group. Similarly, organ failure score, ventilator-free days, intensive care unit-free days, and 60-day mortality did not differ between the groups.. Fish oil did not reduce biomarkers of pulmonary or systemic inflammation in patients with acute lung injury, and the results do not support the conduct of a larger clinical trial in this population with this agent. This experimental approach is feasible for proof-of-concept studies evaluating new treatments for acute lung injury.

Topics: Acute Lung Injury; Adult; Aged; Biomarkers; Body Weight; Bronchoalveolar Lavage Fluid; Cell Count; Chemokine CCL2; Docosahexaenoic Acids; Drug Therapy, Combination; Eicosapentaenoic Acid; Enteral Nutrition; Female; Hospital Mortality; Humans; Interleukin-6; Interleukin-8; Leukotriene B4; Male; Middle Aged; Neutrophils; Pneumonia; Positive-Pressure Respiration, Intrinsic; Pulmonary Surfactant-Associated Protein D; Tidal Volume; von Willebrand Factor

The purposes of this study were: (1) to investigate which arachidonic acid metabolites contributed to platelet-activating factor (PAF) induced pulmonary dysfunction; and (2) to compare the effect of two non-steroidal anti-inflammatory drugs, phenylbutazone and ketoprofen in a model of PAF-induced reversible lung inflammation in six calves. In placebo and phenylbutazone groups, PAF infusion induced significant dysfunctions in the pattern of breathing, mechanics of breathing and gas exchange. These dysfunctions were prevented by ketoprofen pretreatment, except for the mechanics of breathing which was moderately but significantly altered by the PAF challenge. In all calves, leukotriene (LT) B4 plasma concentrations did not significantly increase above baseline values at any time. Prostaglandin (PG) E2 plasma concentrations showed a minor significant increase in phenylbutazone pretreated calves (55.8 +/- 25.8 pg/mL from 36.7 +/- 16.13 pg/mL). Thromboxane (TX) B2 plasma concentration was significantly increased during PAF challenge in placebo- and phenylbutazone-pretreated groups, but not in ketoprofen-pretreated calves (1580.0 +/- 1370 from 42.7 +/- 10.7 pg/mL; 2340 +/- 477 from 63 +/- 32 pg/mL; and 36.5 +/- 4.12 from 39.3 +/- 12.0 pg/mL, respectively). These data suggest that TXA2 is an important cyclooxygenase metabolite of arachidonic acid produced in response to PAF and that ketoprofen (intramuscular injection, 3 mg/kg) is more effective than phenylbutazone (intramuscular injection, 10 mg/kg) in preventing respiratory dysfunctions induced by the PAF challenge 30 min after drug administration. Ketoprofen did not suppress totally the PAF-induced changes in mechanics of breathing, which suggests that PAF or a secondary release of mediators could have a direct action on airway smooth muscle.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Cattle; Cattle Diseases; Dinoprostone; Ketoprofen; Leukotriene B4; Male; Phenylbutazone; Placebos; Platelet Activating Factor; Pneumonia; Respiration; Thromboxane B2

The leukocyte NADPH oxidase 2 (NOX2) regulates inflammation independent of its antimicrobial activity. Inherited defects in NOX2 lead to chronic granulomatous disease (CGD), associated with recurrent bacterial and fungal infections, often with excessive neutrophilic inflammation that results in significant inflammatory burden and tissue damage. We previously showed that excessive leukotriene B4 (LTB4) production by NOX2-deficient mouse neutrophils was a key driver of elevated lung neutrophil infiltration in the initial response to pulmonary challenge with the model fungal particle zymosan. We now identify interleukin-1β (IL-1β) and downstream granulocyte colony-stimulating factor (G-CSF) as critical amplifying signals that augment and sustain neutrophil accrual in CGD mice. Neutrophils, delivered into the lung via LTB4, were the primary source of IL-1β within the airways, and their increased numbers in CGD lungs led to significantly elevated local and plasma G-CSF. Elevated G-CSF simultaneously promoted increased granulopoiesis and mobilized the release of higher numbers of an immature CD101- neutrophil subset from the marrow, which trafficked to the lung and acquired a significantly more proinflammatory transcriptome in CGD mice compared with wild-type mice. Thus, neutrophil-produced IL-1β and downstream G-CSF act sequentially but nonredundantly with LTB4 to deploy neutrophils and amplify inflammation in CGD mice after inhalation of zymosan. NOX2 plays a critical role in dampening multiple components of a feed-forward pipeline for neutrophil recruitment, and these findings highlight NOX2 as a key regulator of neutrophil number, subsets, and function at inflamed sites.

Topics: Animals; Granulocyte Colony-Stimulating Factor; Granulomatous Disease, Chronic; Inflammation; Interleukin-1beta; Leukotriene B4; Mice; NADPH Oxidase 2; NADPH Oxidases; Neutrophils; Pneumonia; Zymosan

Topics: Animals; Endosomes; Humans; Inflammation; JNK Mitogen-Activated Protein Kinases; Leukotriene B4; Lipid Metabolism; Molecular Targeted Therapy; Neutrophils; Pneumonia; Signal Transduction; Silicon Dioxide; Silicosis

Evidence suggests that suppressor of cytokine signaling 1 (SOCS1) is crucial for the negative regulation of inflammation. We investigated the relationship between smoking, SOCS1, and leukotriene B4 (LTB4) in vitro and in clinical samples of COPD; besides which we detected the impact of LTB4 receptor 1 (BLT1) antagonist on inflammation.. SOCS1 expression in bronchial mucosa was determined by immunohistochemistry and real-time polymerase chain reaction. We also detect SOCS1 and BLT1 expression in alveolar macrophages from bronchoalveolar lavage fluid (BALF) by real time-PCR, in addition to measuring the level of cytokines in BALF using enzyme-linked immunosorbent assay. In vitro, we investigated the expression of SOCS1 in cigarette smoke extract-induced mouse macrophage cell line RAW264.7 by real-time polymerase chain reaction and Western blot, and detected the level of cytokines in the supernatant by enzyme-linked immunosorbent assay. Then, we investigated the effects of BLT1 antagonist U-75302 on SOCS1 expression in these cells.. We obtained endobronchial biopsies (15 COPD patients and 12 non-COPD control subjects) and BALF (20 COPD patients and 20 non-COPD control subjects), and our results showed that SOCS1 expression significantly decreased in lung tissues from COPD patients. Inflammatory cytokines in BALF were higher in COPD and these inflammatory cytokines negatively correlate with SOCS1 levels. Further, the BLT1 antagonist restored SOCS1 expression and in turn inhibited inflammatory cytokine secretion in vitro.. Long-term cigarette smoke exposure induced SOCS1 degradation and LTB4 accumulation, which was associated with emphysema and inflammation. A BLT1 antagonist might be a potential therapeutic candidate for the treatment of COPD.

Topics: Aged; Animals; Bronchoalveolar Lavage Fluid; Fatty Alcohols; Female; Glycols; Humans; Immunohistochemistry; Leukotriene B4; Male; Mice; Middle Aged; Pneumonia; Pulmonary Disease, Chronic Obstructive; Pulmonary Emphysema; Receptors, Leukotriene B4; Respiratory Mucosa; Signal Transduction; Smoking; Suppressor of Cytokine Signaling 1 Protein; Suppressor of Cytokine Signaling Proteins

Occupational bioaerosol exposures are capable to cause respiratory diseases. We studied the relationship between exposure to bioaerosols and biomarkers' concentration in exhaled breath condensate (EBC) and fractional exhaled nitric oxide (FeNO) in 119 bioaerosol-exposed compost workers taking into account atopy and smoking habits. Atopy was classified according to specific IgE concentrations to common inhalant allergens (sx1). Bioaerosol exposure was estimated according to job title, duration of employment, results of ambient monitoring at the workplaces, and shift time worked under protection of filtered air supply. Concentrations of 8-iso-prostaglandin F2α (8-iso-PGF2α), prostaglandin E2 (PGE2), leukotriene B4 (LTB4), and acid-base balance (pH) in EBC and FeNO were assessed in 59 never-smoking (NS) and 60 smoking (S) compost workers. We found that atopic subjects were equally distributed among NS and S (n=16 each). Levels of 8-iso-PGF2α were significantly higher in workers considered highly exposed to bioaerosols than in low exposed workers (86.6 (66.1; 128.8) pg/mL vs. 74.4 (56.3; 96.7) pg/mL, p=0.047). No associations could be observed between exposures and biomarkers concerning compost workers in total, but there were some in atopic workers (duration of employment and FeNO: r=0.376, p=0.041; filtered air supply and FeNO: r=-0.335, p=0.071). Smokers had significantly lower pH values compared to NS (non-atopic, p=0.041; atopic p=0.050). In conclusion, EBC and FeNO might be useful tools for monitoring of inflammation due to bioaerosol exposures, especially in atopic subjects. Besides smoking also atopy should be considered when investigating airway inflammation.

Topics: Acid-Base Equilibrium; Adult; Aerosols; Air Pollutants, Occupational; Biomarkers; Cross-Sectional Studies; Dinoprost; Dinoprostone; Exhalation; Female; Humans; Hypersensitivity, Immediate; Immunoglobulin E; Leukotriene B4; Male; Middle Aged; Nitric Oxide; Occupational Exposure; Pneumonia; Smoking; Soil

High diesel exhaust particle levels are associated with increased health effects; however, knowledge on the impact of its chemical contaminant 1,2-naphthoquinone (1,2-NQ) is limited. We investigated whether postnatal and adult exposures to 1,2-NQ influence allergic reaction and the roles of innate and adaptive immunity. Male neonate (6 days) and adult (56 days) C57Bl/6 mice were exposed to 1,2-NQ (100 nM; 15 min) for 3 days, and on day 59, they were sensitized and later challenged with ovalbumin (OVA). Airway hyper-responsiveness (AHR) and production of cytokines, immunoglobulin E (IgE) and leukotriene B4 (LTB4) were measured in the airways. Postnatal exposure to 1,2-NQ activated dendritic cells in splenocytes by increasing expressing cell surface molecules (e.g., CD11c). Co-exposure to OVA effectively polarized T helper (Th) type 2 (Th2) by secreting Th2-mediated cytokines. Re-stimulation with unspecific stimuli (PMA and ionomycin) generated a mixed Th1 (CD4(+)/IFN-γ(+)) and Th17 (CD4(+)/IL-17(+)) phenotype in comparison with the vehicle-matched group. Postnatal exposure to 1,2-NQ did not induce eosinophilia in the airways at adulthood, although it evoked neutrophilia and exacerbated OVA-induced eosinophilia, Th2 cytokines, IgE and LTB4 production without affecting AHR and mast cell degranulation. At adulthood, 1,2-NQ exposure evoked neutrophilia and increased Th1/Th2 cytokine levels, but failed to affect OVA-induced eosinophilia. In conclusion, postnatal exposure to 1,2-NQ increases the susceptibility to antigen-induced asthma. The mechanism appears to be dependent on increased expression of co-stimulatory molecules, which leads to cell presentation amplification, Th2 polarization and enhanced LTB4, humoral response and Th1/Th2 cytokines. These findings may be useful for future investigations on treatments focused on pulmonary illnesses observed in children living in heavy polluted areas.

Topics: Adaptive Immunity; Aging; Air Pollutants; Animals; Animals, Newborn; Cytokines; Disease Susceptibility; Immunity, Innate; Immunoglobulin E; Inhalation Exposure; Leukotriene B4; Male; Naphthoquinones; Ovalbumin; Pneumonia; Respiratory Hypersensitivity; Vehicle Emissions

The accumulation of neutrophils and proinflammatory mediators, such as leukotriene B4 (LTB4), is a classic marker of inflammatory disease. The clearance of apoptotic neutrophils, inhibition of proinflammatory signaling, and production of proresolving lipids (including lipoxins, such as lipoxin A4 [LXA4]) are imperative for resolving inflammation. Tulathromycin (TUL), a macrolide used to treat bovine respiratory disease, confers immunomodulatory benefits via mechanisms that remain unclear. We recently reported the anti-inflammatory properties of TUL in bovine phagocytes in vitro and in Mannheimia haemolytica-challenged calves. The findings demonstrated that this system offers a powerful model for investigating novel mechanisms of pharmacological immunomodulation. In the present study, we examined the effects of TUL in a nonbacterial model of pulmonary inflammation in vivo and characterized its effects on lipid signaling. In bronchoalveolar lavage (BAL) fluid samples from calves challenged with zymosan particles (50 mg), treatment with TUL (2.5 mg/kg of body weight) significantly reduced pulmonary levels of LTB4 and prostaglandin E2 (PGE2). In calcium ionophore (A23187)-stimulated bovine neutrophils, TUL inhibited phospholipase D (PLD), cytosolic phospholipase A2 (PLA2) activity, and the release of LTB4. In contrast, TUL promoted the secretion of LXA4 in resting and A23187-stimulated neutrophils, while levels of its precursor, 15(S)-hydroxyeicosatetraenoic acid [15(S)-HETE], were significantly lower. These findings indicate that TUL directly modulates lipid signaling by inhibiting the production of proinflammatory eicosanoids and promoting the production of proresolving lipoxins.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Bronchoalveolar Lavage Fluid; Calcimycin; Cattle; Dinoprostone; Disaccharides; Heterocyclic Compounds; Hydroxyeicosatetraenoic Acids; Leukotriene B4; Lipoxins; Lung; Male; Neutrophils; Particulate Matter; Phospholipases A2; Pneumonia; Primary Cell Culture; Zymosan

Leukotrienes (i.e., products of the 5-lipoxygenase pathway) are thought to be contributors to lung pathologies. Moreover, eosinophils have been linked with pulmonary leukotriene activities both as potential sources of these mediators and as responding effector cells. The objective of the present study was to define the role(s) of leukotrienes in the lung pathologies accompanying eosinophil-associated chronic respiratory inflammation. A transgenic mouse model of chronic T helper (Th) 2-driven inflammation expressing IL-5 from T cells and human eotaxin-2 locally in the lung (I5/hE2) was used to define potential in vivo relationships among eosinophils, leukotrienes, and chronic Th2-polarized pulmonary inflammation. Airway levels of cys-leukotrienes and leukotriene B4 (LTB4) are both significantly elevated in I5/hE2 mice. The eosinophil-mediated airway hyperresponsiveness (AHR) characteristic of these mice was abolished in the absence of leukotrienes (i.e., 5-lipoxygenase-deficient I5/hE2). More importantly, the loss of leukotrienes led to an unexpectedly significant decrease in collagen deposition (i.e., pulmonary fibrosis) that accompanied elevated levels of IL-4/-13 and TGF-β in the lungs of I5/hE2 mice. Further studies using mice deficient for the LTB4 receptor (BLT-1(-/-)/I5/hE2) and I5/hE2 animals administered a cys-leukotriene receptor antagonist (montelukast) demonstrated that the AHR and the enhanced pulmonary fibrosis characteristic of the I5/hE2 model were uniquely cys-leukotriene-mediated events. These data demonstrate that, similar to allergen challenge models of wild-type mice, cys-leukotrienes underlie AHR in this transgenic model of severe pulmonary Th2 inflammation. These data also suggest that an underappreciated link exists among eosinophils, cys-leukotriene-mediated events, and fibrotic remodeling associated with elevated levels of IL-4/-13 and TGF-β.

Topics: Animals; Arachidonate 5-Lipoxygenase; Bronchial Hyperreactivity; Chemokine CCL24; Disease Models, Animal; Eosinophils; Humans; Interleukin-5; Leukotriene B4; Leukotrienes; Mice; Mice, Inbred C57BL; Mice, Knockout; Mice, Transgenic; Pneumonia; Pulmonary Fibrosis; Receptors, Leukotriene B4; Th2 Cells

This study was designed to determine the effects of peroxisome proliferator-activated receptor-gamma (PPARγ) on airway inflammatory response to cigarette smoke (CS) exposure.. For the in vivo experiments, 50 male Wistar rats were randomly assigned to one of four groups and were exposed to CS and pretreatment with a PPARγ agonist, rosiglitazone or a vehicle (saline). PPARγ antagonist bisphenol A diglycidyl ether (BADGE) or saline was administered before rosiglitazone treatment. Leukotriene B4 (LTB4) and interleukin-8 (IL-8) were measured by enzyme-linked immunosorbent assay. PPARγ and toll-like receptor 4 (TLR4) expression levels were assessed by immunohistochemistry and real-time polymerase chain reaction. For the in vitro experiments, human bronchial epithelial cells were stimulated with CS or phosphate buffer saline, pretreated with PPARγ agonist rosiglitazone or 15-deoxy-(Δ12,14)-PG J2 before CS exposure. BADGE was administered prior to the agonist treatment. PPARγ, TLR4 and inhibitor of κB (IκBα) expression levels were assessed by Western bot.. CS exposure decreased PPARγ expression, as well as increased IL-8, LTB4 and TLR4 expression levels in bronchial epithelial cells in vivo and in vitro. Moreover, PPARγ ligands counteracted CS-induced airway inflammation by reducing IL-8 and LTB4 expression levels that are associated with TLR4 and nuclear factor-kappa B (NF-κB).. CS exposure increased the pro-inflammatory activity of bronchial epithelial cells by affecting PPARγ expression. Moreover, PPARγ may play a significant role as a modulator of the TLR4-dependent inflammatory pathway through NF-κB in bronchial epithelial cells.

Topics: Animals; Benzhydryl Compounds; Bronchi; Cell Survival; Cells, Cultured; Disease Models, Animal; Down-Regulation; Epithelial Cells; Epoxy Compounds; In Vitro Techniques; Interleukin-8; Leukotriene B4; Male; NF-kappa B; Pneumonia; PPAR gamma; Rats; Rats, Wistar; Rosiglitazone; Smoking; Thiazolidinediones; Toll-Like Receptor 4; Up-Regulation

Leukotriene A(4) hydrolase (LTA(4)H) is a proinflammatory enzyme that generates the inflammatory mediator leukotriene B(4) (LTB(4)). LTA(4)H also possesses aminopeptidase activity with unknown substrate and physiological importance; we identified the neutrophil chemoattractant proline-glycine-proline (PGP) as this physiological substrate. PGP is a biomarker for chronic obstructive pulmonary disease (COPD) and is implicated in neutrophil persistence in the lung. In acute neutrophil-driven inflammation, PGP was degraded by LTA(4)H, which facilitated the resolution of inflammation. In contrast, cigarette smoke, a major risk factor for the development of COPD, selectively inhibited LTA(4)H aminopeptidase activity, which led to the accumulation of PGP and neutrophils. These studies imply that therapeutic strategies inhibiting LTA(4)H to prevent LTB(4) generation may not reduce neutrophil recruitment because of elevated levels of PGP.

Topics: Acetylation; Animals; Bronchoalveolar Lavage Fluid; Cells, Cultured; Chemokines, CXC; Chemotaxis, Leukocyte; Epoxide Hydrolases; Female; Humans; Inflammation; Leukotriene B4; Lung; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Neutrophils; Nicotiana; Oligopeptides; Orthomyxoviridae Infections; Pneumococcal Infections; Pneumonia; Proline; Pulmonary Disease, Chronic Obstructive; Smoke

Topics: Acetylation; Animals; Chemokines, CXC; Chemotaxis, Leukocyte; Epoxide Hydrolases; Humans; Inflammation; Leukotriene B4; Lung; Mice; Neutrophil Activation; Neutrophils; Nicotiana; Oligopeptides; Orthomyxoviridae Infections; Pneumococcal Infections; Pneumonia; Proline; Pulmonary Disease, Chronic Obstructive; Smoke

Statins have been proposed as a novel treatment of respiratory diseases. To determine the beneficial effects of statins on allergic bronchial asthma, the effect of systemic treatment with lovastatin on antigen-induced airway inflammation was investigated.. Male BALB/c mice were used.. Mice were sensitized and repeatedly challenged with ovalbumin (OA) antigen to induce asthmatic response. Animals were also treated with lovastatin (4 mg/kg/day, i.p.) once a day prior to and during the antigen inhalation period.. Inflammatory cell counts and levels of interleukin (IL)-4, IL-13, eotaxin, thymus and activation-regulated chemokine and leukotriene B(4) (LTB(4)) in bronchoalveolar lavage (BAL) fluids were measured.. Significant increases in eosinophils and levels of the T helper 2 cytokines, chemokines and LTB(4) in BAL fluids in association with the increments of total and OA-specific immunoglobulin E (IgE) in sera were observed in the repeatedly antigen-challenged mice. The airway eosinophilia was ameliorated by lovastatin, whereas it had no significant effect on the levels of these inflammatory mediators or IgE.. Lovastatin may be beneficial for the treatment of allergic inflammatory diseases in the airways, such as allergic bronchial asthma.

Topics: Animals; Anti-Inflammatory Agents; Antigens; Asthma; Bronchoalveolar Lavage Fluid; Cell Count; Cytokines; Disease Models, Animal; Eosinophilia; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Immunoglobulin E; Inflammation Mediators; Leukotriene B4; Lovastatin; Male; Mice; Mice, Inbred BALB C; Ovalbumin; Pneumonia

Leukotrienes (LTs) are proinflammatory lipid mediators synthesized by the conversion of arachidonic acid (AA) to LTA(4) by the enzyme 5-lipoxygenase (5-LO) in the presence of 5-LO-activating protein (FLAP). 3-[3-tert-Butylsulfanyl-1-[4-(6-methoxy-pyridin-3-yl)-benzyl]-5-(pyridin-2-ylmethoxy)-1H-indol-2-yl]-2,2-dimethyl-propionic acid (AM103) is a novel selective FLAP inhibitor in development for the treatment of respiratory conditions such as asthma. In a rat ex vivo whole-blood calcium ionophore-induced LTB(4) assay, AM103 (administered orally at 1 mg/kg) displayed >50% inhibition for up to 6 h with a calculated EC(50) of approximately 60 nM. When rat lung was challenged in vivo with calcium ionophore, AM103 inhibited LTB(4) and cysteinyl leukotriene (CysLT) production with ED(50) values of 0.8 and 1 mg/kg, respectively. In this model, the EC(50) derived from plasma AM103 was approximately 330 nM for inhibition of both LTB(4) and CysLT. In an acute inflammation setting, AM103 displayed dose-dependent inhibition of LTB(4), CysLT, and plasma protein extravasation induced by peritoneal zymosan injection. In a model of chronic lung inflammation using ovalbumin-primed and challenged BALB/c mice, AM103 reduced the concentrations of eosinophil peroxidase, CysLTs, and interleukin-5 in the bronchoalveolar lavage fluid. Finally, AM103 increased survival time in mice exposed to a lethal intravenous injection of platelet-activating factor. In summary, AM103 is a novel, potent and selective FLAP inhibitor that has excellent pharmacodynamic properties in vivo and is effective in animal models of acute and chronic inflammation and in a model of lethal shock.

Topics: 5-Lipoxygenase-Activating Proteins; Acute Disease; Administration, Oral; Animals; Anti-Inflammatory Agents, Non-Steroidal; Asthma; Carrier Proteins; Chronic Disease; Disease Models, Animal; Dose-Response Relationship, Drug; Extravasation of Diagnostic and Therapeutic Materials; Female; Humans; Indoles; Inflammation; Leukotriene B4; Male; Membrane Proteins; Mice; Mice, Inbred BALB C; Pneumonia; Propionates; Rats; Rats, Sprague-Dawley; Zymosan

The infiltrate in pneumonia is characterized by a large number of activated neutrophils, for which leukotriene B4 (LTB4) is a strong chemotactic agent. Exhaled breath condensate (EBC) is a non-invasive technique for studying the lower airways. The present study was conducted to measure EBC LTB4 as a potential non-invasive marker of inflammatory response in community acquired pneumonia (CAP).. Eighteen children with CAP and 17 healthy children were recruited (age 5-13). The CAP children underwent physical examination, chest X-ray, leukocyte count and C-reactive protein measurement. The CAP and the control children performed spirometry, exhaled nitric oxide measurement (FE(NO)) and EBC collection for LTB4 assessment. In the CAP children spirometry, FE(NO) and EBC collection were repeated twice over a 1-month follow-up.. LTB4 EBC concentrations were higher in children with CAP than in healthy controls (10 pg/ml [7.0-15.3] vs. 3 pg/ml [3.0-6.9], P = 0.001) and decreased after 1 week (3 pg/ml [3.0-7.2], P < 0.01) with no further change a month later. In the acute phase spirometry demonstrated a restrictive pattern that gradually improved later. No difference in FE(NO) levels was found between children with CAP and healthy controls.. Exhaled LTB4 levels increase in CAP and return to normal after 1 week. EBC collection is feasible in children with CAP and may represent a new way to non-invasively monitor the lung's biological response to infections.

Topics: Biomarkers; Breath Tests; Child; Community-Acquired Infections; Exhalation; Female; Humans; Inflammation; Leukotriene B4; Male; Neutrophils; Pneumonia

Leukotriene B(4) (LTB(4)) plays a crucial role in the recruitment of neutrophils into the pleural space. We identified for the first time the mechanisms by which LTB(4) interacts with mesothelial cells and recruits neutrophils in the pleural compartment. Primary pleural mesothelial cells express both the proinflammatory receptor for LTB(4) BLT2, and the anti-inflammatory receptor for LTB(4), PPARalpha. Parapneumonic pleural effusions highly increase BLT2 expression and, via BLT2 activation, increase the adhesion between mesothelial cells and neutrophils and the expression of ICAM-1 on mesothelial cells. The block of PPARalpha further increases both cell adhesion and ICAM-1 expression. BLT2 activation promotes the activation, on mesothelial cells, of STAT-1 but not the activation of NF-kappaB transcription factor. The increase of ICAM-1 expression is achieved via increased tyrosine phosphorylation activity since herbimycin, a tyrosine kinase inhibitor, reduces and since Na orthovanadate, a tyrosine phosphatase inhibitor, further increases ICAM-1 expression. This study demonstrates that pleural mesothelial cells, expressing both proinflammatory and anti-inflammatory LTB(4) receptors, are able to mount an integrated response to LTB(4) with a prevalence of BLT2 activities in the presence of an inflammatory milieu within the pleura.

Topics: Adult; Aged; Blotting, Western; Cell Adhesion; Cells, Cultured; Chemotaxis, Leukocyte; Epithelium; Flow Cytometry; Humans; Inflammation; Intercellular Adhesion Molecule-1; Leukotriene B4; Middle Aged; Neutrophil Infiltration; Pleura; Pleural Effusion; Pneumonia; PPAR alpha; Receptors, Leukotriene B4

A critical role for leukotriene B(4) (LTB(4)) and/or platelet-activating factor (PAF) in regulating polymorphonuclear cell (PMN) trafficking to inflammatory sites has been reported in a number of experimental inflammatory models. In vitro, newly synthesized LTB(4) and PAF were shown to act in an autocrine/paracrine or intracrine fashion to enhance intracellular arachidonic acid availability and leukotriene biosynthesis. This suggested potentially cooperative effects of these lipid mediators in regulating PMN extravasation. The present study aimed to elucidate whether endogenous LTB(4) and PAF may both act to regulate plasma extravasation and PMN trafficking to inflammatory sites in experimental inflammation. With this aim, we have used selective and potent PAF and LTB(4) receptor antagonist pretreatments in dermal and pulmonary inflammation models in rats. Our results show additive inhibitory effects of dual LTB(4) and PAF receptor blockade in either PAF- or LTB(4)-elicited cutaneous PMN accumulation compared to single-drug administration. Furthermore, the combined administration of the drugs inhibited the PMN accumulation induced by the chemically unrelated soluble agonists tumour necrosis factor-alpha and C5a. Finally, in a model of pulmonary inflammation induced by the intravenous injection of Sephadex beads, lung neutrophilia was reduced by 63% following the administration of LTB(4) and PAF antagonists, in contrast with the lack of effect of single drug administration. Our results strongly support a role of both endogenous LTB(4) and PAF in regulating PMN trafficking to inflammatory sites in various experimental conditions.

Topics: Animals; Benzopyrans; Carboxylic Acids; Dermatitis; Dihydropyridines; Imidazoles; Leukotriene B4; Male; Neutrophil Infiltration; Neutrophils; Platelet Activating Factor; Platelet Membrane Glycoproteins; Pneumonia; Rats; Rats, Sprague-Dawley; Receptors, G-Protein-Coupled; Receptors, Leukotriene B4; Skin; Thiazoles

Traumatic brain injury is known to cause several secondary effects, which lead to multiple organ dysfunction syndrome. An acute systemic inflammatory response seems to play an integral role in the development of such complications providing the potential for massive secondary injury. We show that a contusion injury to the rat brain causes large migration of inflammatory cells (especially macrophages and neutrophils) in the major airways and alveolar spaces at 24 h post-injury, which is associated with enhanced pulmonary leukotriene B4 (LTB4) production within the lung. However, by 2 weeks after injury, a temporal switch occurs and the resolution of inflammation is underway. We provide evidence that 5-lipoxygenase and Cytochrome P450 4Fs (CYP4Fs), the respective enzymes responsible for LTB4 synthesis and breakdown, play crucial roles in setting the cellular concentration of LTB4. Activation of LTB4 breakdown via induction of CYP4Fs, predominantly in the lung tissue, serves as an endogenous signal to ameliorate further secondary damage. In addition, we show that CYP4Fs are localized primarily in the airways and pulmonary endothelium. Given the fact that adherence to the microvascular endothelium is an initial step in neutrophil diapedesis, the temporally regulated LTB4 clearance in the endothelium presents a novel focus for treatment of pulmonary inflammation after injury.

Topics: Accidents, Traffic; Animals; Blood-Brain Barrier; Blotting, Western; Brain Injuries; Bronchoalveolar Lavage Fluid; Cytochrome P-450 Enzyme System; Female; Humans; Immunoenzyme Techniques; Immunohistochemistry; Leukotriene B4; Lung; Lung Diseases; Male; Microscopy, Confocal; Pneumonia; Proteins; Rats; Rats, Long-Evans; Reverse Transcriptase Polymerase Chain Reaction; RNA

To study whether patients with chronic obstructive pulmonary disease (COPD) at the same level of flow limitation but with different clinical phenotypes present different degrees of systemic and/or pulmonary inflammation.. We studied 15 male smokers without COPD (control group) and 39 males with COPD in stable clinical condition. The COPD patients were assigned to 2 groups based on the ratio of carbon monoxide diffusing capacity (DLCO) to alveolar volume (DLCO/VA) expressed as a percentage as follows: a) mainly emphysema (n = 15) and b) mainly chronic bronchitis (n = 24). Classification was determined by comparing both clinical features and diagnostic images.. Mean (SD) concentrations of interleukin 8 (IL-8) and 8-isoprostane in exhaled breath condensate (EBC) were significantly lower in patients with mainly emphysema (IL-8, 0.34 [0.70] pg/mL; 8-isoprostane, 0.07 [0.26] pg/mL) than in patients with chronic bronchitis (IL-8, 2.32 [3.10] pg/mL; 8-isoprostane, 1.77 [2.98] pg/mL) or in the controls (IL-8, 3.14 [4.59] pg/mL; 8-isoprostane, 1.92 [2.84] pg/mL); P < .05 for IL-8 comparisons and P < .01 for 8-isoprostane. IL-8, leukotriene B4, and 8-isoprostano in EBC correlated significantly with DLCO/VA (% of predicted) (r = 0.30, P < .05; r = 0.29, P < or = .05; and r = 0.46, P < .01, respectively) but not with forced expiratory volume in 1 second. There was a negative correlation between EBC and serum levels of both IL-8 (r = -0.31; P < .05) and 8-isoprostane (r = -0.51; P < .001). The correlation between leukotriene B4 concentrations in EBC and serum was not significant, however. No significant differences were found between smokers' and ex-smokers' serum levels of IL-8, leukotriene B4, 8-isoprostane in serum or EBC.. The results indicate that COPD patients with an emphysematous phenotype have a less intense inflammatory response and less oxidative stress in the lung.

Topics: Carbon Monoxide; Diffusion; Dinoprost; Emphysema; Humans; Hydrogen-Ion Concentration; Interleukin-8; Leukotriene B4; Male; Middle Aged; Oxidative Stress; Phenotype; Pneumonia; Pulmonary Disease, Chronic Obstructive; Smoking

The role of a cytosolic phospholipase A(2)-alpha (cPLA(2)-alpha) in neutrophil arachidonic acid release, platelet-activating factor (PAF) biosynthesis, NADPH oxidase activation, and bacterial killing in vitro, and the innate immune response to bacterial infection in vivo was examined. cPLA(2)-alpha activity was blocked with the specific cPLA(2)-alpha inhibitor, Pyrrolidine-1 (human cells), or by cPLA(2) -alpha gene disruption (mice). cPLA(2)-alpha inhibition or gene disruption led to complete suppression of neutrophil arachidonate release and PAF biosynthesis but had no effect on neutrophil NADPH oxidase activation, FcgammaII/III or CD11b surface expression, primary or secondary granule secretion, or phagocytosis of Escherichia coli in vitro. In contrast, cPLA(2)-alpha inhibition or gene disruption diminished neutrophil-mediated E. coli killing in vitro, which was partially rescued by exogenous arachidonic acid or PAF but not leukotriene B(4). Following intratracheal inoculation with live E. coli in vivo, pulmonary PAF biosynthesis, inflammatory cell infiltration, and clearance of E. coli were attenuated in cPLA(2)-alpha(-/-) mice compared with wild type littermates. These studies identify a novel role for cPLA(2)-alpha in the regulation of neutrophil-mediated bacterial killing and the innate immune response to bacterial infection.

Topics: Animals; Arachidonic Acid; Bronchoalveolar Lavage Fluid; CD11b Antigen; Cytosol; Dose-Response Relationship, Drug; Escherichia coli; Group IV Phospholipases A2; Humans; Inflammation; Ionomycin; Leukotriene B4; Mice; Mice, Transgenic; NADPH Oxidases; Neutrophils; Oxygen; Phagocytosis; Phospholipases A; Phospholipases A2; Platelet Activating Factor; Pneumonia; Pyrrolidines; Receptors, IgG; Time Factors; Tumor Necrosis Factor-alpha

Lipoxins and 15-epi-lipoxins are lipid mediators that modulate leukocyte trafficking and promote the inflammation resolution. They are produced by different enzymatic pathways. Patients with severe asthma present ongoing airway inflammation despite chronic long-term treatment including oral glucocorticoids.. The aim of this study was to assess the presence of proinflammatory and anti-inflammatory mediators in the supernatants of induced sputum.. Induced sputum supernatants were collected from 10 normal subjects; 12 subjects with mild, 15 with moderate, and 24 with severe asthma; and 13 patients with chronic obstructive pulmonary disease. First, we validated the measurements of IL-8, leukotriene B 4 , lipoxin A 4 , and 15-epi-lipoxin A 4 in these samples. Then we measured these mediators by using immunoenzymatic methods.. IL-8 levels were highly increased in patients with severe asthma ( P < .0001), and leukotriene B 4 levels were significantly increased in patients with severe asthma and patients with chronic obstructive pulmonary disease. Lipoxin A 4 was significantly increased in the supernatant obtained from patients with mild asthma ( P < .0001), whereas 15-epi-lipoxin A 4 levels were higher in patients with severe asthma ( P = .05). More interestingly, we found a positive correlation between the level of lipoxin A 4 and IL-8 in patients with mild asthma.. These results indicate that induced sputum is a suitable method to assess lipoxin and 15-epi-lipoxin measurements in bronchi. The mechanisms involved in the synthesis of these 2 eicosanoid mediators would be helpful to understand better the imbalance between proinflammatory and anti-inflammatory mediators occurring in severe asthma. Lipoxin production involves interaction between lipoxygenases, whereas 15-epi-lipoxin production might involve CytP450 activity.

Topics: Adult; Asthma; Female; Humans; Interleukin-8; Leukotriene B4; Lipoxins; Male; Middle Aged; Pneumonia; Pulmonary Disease, Chronic Obstructive; Sputum

Cough is a common symptom in idiopathic pulmonary fibrosis that is difficult to treat and has a major impact on quality of life. We tested the hypothesis that the cough and increased cough reflex sensitivity seen in patients with idiopathic pulmonary fibrosis may be due to airway inflammation in a prospective, cross-sectional study.. We measured the induced sputum inflammatory cell profile and cell-free supernatant inflammatory mediator concentrations in 15 patients with idiopathic pulmonary fibrosis, 17 healthy controls and 15 patients with chronic obstructive pulmonary disease.. Both the geometric mean sputum differential eosinophil cell count and median eosinophilic-cationic-protein concentration were significantly higher in patients with idiopathic pulmonary fibrosis than controls (2.1% vs 0.3%; p <0.001 and 1.1 mg/ml versus 0.2 mg/ml; p=0.03 respectively). There were no significant differences in sputum eosinophil counts and eosinophilic-cationic-protein concentrations between patients with idiopathic pulmonary fibrosis and chronic obstructive pulmonary disease. Sputum leukotriene-B4 concentrations were significantly lower in patients with idiopathic pulmonary fibrosis (p=0.03) and chronic obstructive pulmonary disease (p=0.008) compared to controls.. Idiopathic pulmonary fibrosis is characterised by the presence of active eosinophilic airway inflammation raising the possibility that airway inflammation may contribute to symptoms such as cough.

Topics: Aged; Case-Control Studies; Cross-Sectional Studies; Eosinophil Cationic Protein; Eosinophilia; Eosinophils; Female; Humans; Leukocyte Count; Leukotriene B4; Male; Middle Aged; Osmolar Concentration; Pneumonia; Prospective Studies; Pulmonary Disease, Chronic Obstructive; Pulmonary Fibrosis; Spirometry; Sputum

Association between staphylococcal infection and pathogenesis of upper airways disease has been reported. This study aimed to investigate the mechanisms underlying the rat pulmonary inflammation induced by airway exposure to staphylococcal enterotoxin A (SEA). SEA (0.3-10 ng trachea(-1)) caused dose-dependent neutrophil accumulation in BAL fluid, reaching maximal responses at 4 h (25-fold increase for 3 ng trachea(-1)). Significant accumulation of both lymphocytes and macrophages in BAL fluid was also observed at 4 h (2.1- and 1.9-fold increase, respectively, for 3 ng trachea(-1)). At later times (16 h), neutrophil counts in bone marrow (immature forms) and peripheral blood increased by 63 and 81%, respectively. SEA failed to directly induce chemotaxis and adhesion of isolated neutrophils. Analysis of mRNA expression for iNOS, COX-2 and CINC-2 in lung tissue showed an upregulation of these enzymes, which paralleled elevated levels of LTB4, PGE2, TNF-alpha, IL-6 and NO2- in BAL fluid. Expression of CINC-1 was unchanged, whereas CINC-3 was reduced in SEA-treated rats. Incubation of isolated alveolar macrophages with SEA (3 microg ml(-1)) resulted in significant elevations of TNF-alpha and NO2- levels in the cell supernatants. Dexamethasone (0.5 mg kg(-1)), celecoxib (3 mg kg(-1)) and compound 1400 W (5 mg kg(-1)) markedly reduced SEA-induced lung neutrophil influx and NO2- levels in BAL fluid. The lipoxygenase inhibitor AA-861 (100 microg kg(-1)) partly inhibited the neutrophil influx in SEA-treated rats without modifying the NO2- levels. None of these treatments reduced the number of mononuclear cells in BAL fluid (except of dexamethasone, which abolished the increased lymphocyte counts). Our study shows that airways exposure to SEA results in marked neutrophil influx through mechanisms involving increased expressions of CINC-2, iNOS and COX-2, as well as enhanced production of NO, PGE2, LTB4, TNF-alpha and IL-6.

Topics: Animals; Bronchoalveolar Lavage Fluid; Chemokine CXCL1; Chemokines, CXC; Chemotaxis, Leukocyte; Cyclooxygenase 2; Dinoprostone; Enterotoxins; Intercellular Signaling Peptides and Proteins; Interleukins; Leukocytes, Mononuclear; Leukotriene B4; Lung; Macrophages, Alveolar; Male; N-Formylmethionine Leucyl-Phenylalanine; Neutrophil Infiltration; Nitric Oxide Synthase Type II; Nitrites; Pneumonia; Rats; Rats, Wistar; RNA, Messenger; Tumor Necrosis Factor-alpha

Cardiac surgery using cardiopulmonary by-pass and, to a greater extent, lung resection, causes acute lung injury that is usually subclinical. Analysis of mediators in exhaled breath condensate is a promising means of monitoring inflammation in a variety of airway diseases but the contribution of the airway lining fluid from the lower respiratory tract is uncertain. We compared the analysis of markers of lung injury in exhaled breath condensate and bronchoalveolar lavage in endotracheally intubated patients before and after coronary artery bypass graft surgery with cardiopulmonary bypass and lobectomy. The neutrophil count and leukotriene B4 concentration in bronchoalveolar lavage fluid rose after coronary artery bypass graft surgery (p < 0.05), but there was no significant change in leukotriene B4, hydrogen peroxide, or hydrogen ion concentrations in exhaled breath condensate. By contrast, after lobectomy, the concentration in exhaled breath condensate of leukotriene B4, hydrogen peroxide and hydrogen ions rose significantly (p < 0.05). Exhaled breath condensate is a safe, noninvasive method of sampling the milieu of the distal lung and is sufficiently sensitive to detect markers of inflammation and oxidative stress in patients after lobectomy, but not after the milder insult associated with cardiac surgery.

Topics: Aged; Breath Tests; Bronchoalveolar Lavage Fluid; Cohort Studies; Coronary Artery Bypass; Dinoprost; F2-Isoprostanes; Female; Humans; Inflammation Mediators; Leukotriene B4; Male; Mass Spectrometry; Middle Aged; Pneumonia; Postoperative Complications; Probability; Prognosis; Risk Assessment; Sensitivity and Specificity; Severity of Illness Index; Statistics, Nonparametric

Individuals with alpha(1)-antitrypsin (alpha(1)-AT) deficiency are at risk for early-onset destructive lung disease as a result of insufficient lower respiratory tract alpha(1)-AT and an increased burden of neutrophil products such as elastase. Human neutrophil peptides (HNP), the most abundant protein component of neutrophil azurophilic granules, represent another potential inflammatory component in lung disease characterized by increased numbers of activated or deteriorating neutrophils. The purpose of this study was to determine the role of HNP in lower respiratory tract inflammation and destruction occuring in alpha(1)-AT deficiency. alpha(1)-AT-deficient individuals (n = 33) and healthy control subjects (n = 21) were evaluated by bronchoalveolar lavage. HNP concentrations were significantly higher in alpha(1)-AT-deficient individuals (1,976 +/- 692 vs. 29 +/- 12 nM, P < 0.0001), and levels correlated with markers of neutrophil-mediated lung inflammation. In vitro, HNP produced a dose-dependent cytotoxic effect on alveolar macrophages and stimulated production of the potent neutrophil chemoattractants leukotriene B(4) and interleukin-8 by alveolar macrophages, with a 6- to 10-fold increase in chemoattractant production over negative control cultures (P < 0.05). A synergistic effect was noted between HNP and neutrophil elastase with regard to leukotriene B(4) production. Importantly, the proinflammatory effects of HNP were blocked by alpha(1)-AT. HNP likely play an important role in amplifying and maintaining neutrophil-mediated inflammation in the lungs.

Topics: Adult; alpha 1-Antitrypsin; alpha 1-Antitrypsin Deficiency; alpha-Defensins; Bronchoalveolar Lavage Fluid; Cells, Cultured; Cytotoxicity Tests, Immunologic; Dose-Response Relationship, Immunologic; Female; Humans; Interleukin-8; Leukocyte Elastase; Leukotriene B4; Macrophages, Alveolar; Male; Middle Aged; Neutrophils; Pneumonia

The pleural space is a virtual compartment between the lung and chest wall that becomes filled with fluid and inflammatory cells during a variety of respiratory diseases. Here, we study the potential role of the eicosanoid metabolite leukotriene B4 (LTB4) in disparate diseases leading to acute (pneumonia) or chronic (tuberculosis, cancer) inflammation of the pleural space. LTB4 concentrations were significantly higher in pleural fluid due to pneumonia, tuberculosis and cancer with respect to congestive heart failure and correlated with neutrophil elastase, which is used as an indication of state of activation of neutrophils in the pleural space. Moreover, pleural LTB4 was biologically active, as an anti-LTB4 antibody partially neutralized the chemotactic activity of parapneumonic, tuberculous and cancer effusions. Macrophages, neutrophils, lymphocytes, mesothelial cells and cancer cells all expressed mRNA for 5-lipoxygenase, the enzyme that initiates leukotriene synthesis leading to the production of LTB4, in exudative pleural effusions. Upon stimulation in transudative pleural effusions, pleural macrophages produced, in a time-dependent fashion, a significantly higher concentration of LTB4 than mesothelial cells. These studies demonstrate that different cell types are capable of producing LTB4 in the inflamed pleural space and that this mediator may play a crucial role in the recruitment of neutrophils into the pleural space.

Topics: Adult; Aged; Arachidonate 5-Lipoxygenase; Chemotaxis, Leukocyte; Epithelium; Gene Expression; Hot Temperature; Humans; Leukotriene B4; Lipopolysaccharides; Macrophage Activation; Middle Aged; Neoplasms; Neutrophil Infiltration; Neutrophils; Pancreatic Elastase; Pleural Effusion; Pneumonia; RNA, Messenger; Tuberculosis, Pulmonary

The involvement of arachidonic acid (AA) and PGE2 during the E. coli lipopolysaccharide (LPS)-induced acute lung injury was investigated.. Adult male Wistar rats were used. For in vitro studies, rat neutrophils, bronchoalveolar lavage (BAL) fluid, and lug vascular endothelium were used, as described below.. Rats were given an intratracheal injection of LPS (750 microg).. Total and differential cell counts in BAL fluid; enzyme-linked immunoassay (ELISA) analyses of TNF-alpha, IL-1beta, LTB4 and PGE2 in BAL, and immunohistochemical detection of ICAM-1 on lung vascular endothelium were performed six h after LPS challenge. Fatty acid composition of blood neutrophils and plasma was analyzed by HPLC.. Rats instilled with LPS presented a sixty three-fold increase in the number of neutrophils in BAL (from 0.5 x 10(6) to 31.5 x 10(6) cells), accompanied by increased levels of TNF-alpha and IL-1beta (p < 0.001), and a three-fold increase in ICAM-1 expression on vascular endothelium. The content of AA in blood neutrophils was reduced by 50%, whereas the level of PGE2 in BAL was increased by 3.5 fold, without changes in the levels of LTB4.. These findings suggest that AA and PGE2 are associated with LPS challenge.

Topics: Acute Disease; Animals; Arachidonic Acid; Bronchoalveolar Lavage Fluid; Dinoprostone; Escherichia coli; Immunohistochemistry; Intercellular Adhesion Molecule-1; Interleukin-1; Leukocyte Count; Leukotriene B4; Lipopolysaccharides; Lung; Male; Neutrophils; Pneumonia; Rats; Rats, Wistar; Tumor Necrosis Factor-alpha

Exacerbations are an important feature of chronic obstructive pulmonary disease (COPD), accounting for a large proportion of health care costs. They are associated with increased airway inflammation and oxidative stress.. Concentrations of leukotriene B4 (LTB4), a marker of inflammation, and 8-isoprostane, a marker of oxidative stress, were measured in the exhaled breath condensate of 21 patients (11 M) with COPD during an exacerbation and 2 weeks after treatment with antibiotics. In 12 patients who had no further exacerbations these markers were also measured after 2 months.. LTB4 concentrations were raised during the COPD exacerbation (mean (SE) 15.8 (1.1) pg/ml and fell after treatment with antibiotics to 9.9 (0.9) pg/ml (p<0.0001). In 12 patients the level of LTB4 fell further from 10.6 (1.1) pg/ml to 8.5 (0.8) pg/ml (p<0.005) after 2 months. In 12 normal age matched subjects the LTB4 levels were 7.7 (0.5) pg/ml. Concentrations of 8-isoprostane were also increased during the exacerbation (13.0 (0.9) pg/ml) and fell after antibiotic treatment to 9.0 (0.6) pg/ml (p<0.0001). In 12 patients there was a further fall from 9.3 (0.7) pg/ml to 6.0 (0.7) pg/ml (p<0.001) after 2 months compared with normal subjects (6.2 (0.4) pg/ml).. Non-invasive markers of inflammation and oxidative stress are increased during an infective exacerbation of COPD and only slowly recover after treatment with antibiotics.

Topics: Adrenal Cortex Hormones; Adrenergic beta-2 Receptor Antagonists; Adrenergic beta-Agonists; Aged; Anti-Bacterial Agents; Biomarkers; Breath Tests; Dinoprost; F2-Isoprostanes; Female; Forced Expiratory Volume; Humans; Leukotriene B4; Male; Oxidative Stress; Pneumonia; Pulmonary Disease, Chronic Obstructive; Vital Capacity

Human airway epithelial cell release of interleukin (IL)-6 in response to lipid mediators was studied in an airway cell line (BEAS-2B). Prostaglandin (PG) E(2) (10(-7) M) treatment caused an increase in IL-6 release at 2, 4, 8, and 24 h. IL-6 release into the culture medium at 24 h was 3,396 +/- 306 vs. 1,051 +/- 154 pg/ml (PGE(2)-treated cells vs. control cells). PGE(2) (10(-7) to 10(-10) M) induced a dose-related increase in IL-6 release at 24 h. PGF(2 alpha) (10(-6) M) treatment caused a similar effect to that of PGE(2) (10(-7) M). PGE(2) analogs with relative selectivity for PGE(2) receptor subtypes were studied. Sulprostone, a selective agonist for the EP-3 receptor subtype had no effect on IL-6 release. 11-Deoxy-16,16-dimethyl-PGE(2), an EP-2/4 agonist, and 17-phenyl trinor PGE(2), an agonist selective for the EP-1 > EP-3 receptor subtype (10(-6) to 10(-8) M), caused dose-dependent increases in IL-6 release. 8-Bromo-cAMP treatment resulted in dose-related increases in IL-6 release. RT-PCR of BEAS-2B cell mRNA demonstrated mRNA for EP-1, EP-2, and EP-4 receptors. After PGE(2) treatment, increases in IL-6 mRNA were noted at 4 and 18 h. Therefore, PGE(2) increases airway epithelial cell IL-6 production and release.

Topics: 8-Bromo Cyclic Adenosine Monophosphate; Bronchi; Cell Line, Transformed; Chemotactic Factors; Dinoprostone; Epithelial Cells; Gene Expression; HeLa Cells; Humans; Hydroxyeicosatetraenoic Acids; Interleukin-6; Leukotriene B4; Platelet Activating Factor; Pneumonia; Respiratory Mucosa; RNA, Messenger

To determine if methotrexate (MTX) induces human lung fibroblast (HFL-1) and epithelial (BEAS 2B) cell lines to release eosinophil chemotactic activity (ECA).. HFL-1 and BEAS 2B cell supernatant fluids were evaluated for ECA by a blind well chamber technique.. HFL-1 and BEAS-2B cells released ECA in a dose and time dependent manner in response to MTX. Partial characterization revealed that ECA was partly heat labile, trypsin sensitive, and ethylacetate extractable. Thus the culture supernatant fluids were evaluated for known eosinophil chemotactic factors. Although several were released constitutively, granulocyte-macrophage colony-stimulating factor (GM-CSF) was significantly increased in response to MTX from both cell types. Consistent with these observations, ECA from both cell types was inhibited by GM-CSF antibodies.. These data suggest that lung fibroblasts and epithelial cells may modulate eosinophil recruitment into the lung by releasing ECA in response to MTX.

Topics: Antibodies; Antirheumatic Agents; Cell Line, Transformed; Chemokine CCL11; Chemokine CCL5; Chemokines, CC; Chemotaxis, Leukocyte; Cytokines; Dose-Response Relationship, Drug; Eosinophils; Epithelial Cells; Fetus; Fibroblasts; Granulocyte-Macrophage Colony-Stimulating Factor; Humans; Immunosuppressive Agents; Interleukin-5; Leukotriene B4; Lung; Methotrexate; Phenylpropionates; Pneumonia; Receptors, Leukotriene B4

Bacterial lipopolysaccharide (LPS) is a risk factor for exacerbation of asthma and causes airway inflammation. The aim of this study was to examine the effects of disruption of prostaglandin (PG) H synthase (PGHS)-1 and PGHS-2 genes on pulmonary responses to inhaled LPS. PGHS-1(-/-), PGHS-2(-/-), and wild-type (WT) mice were exposed to 4 to 6 microg/m(3) LPS via aerosol. Enhanced pause (PenH), a measure of bronchoconstriction, was assessed using a whole-body plethysmograph before and immediately after a 4-h LPS exposure. Bronchoalveolar lavage (BAL) was performed after LPS exposure to assess inflammatory cells, cytokines/chemokines (tumor necrosis factor-alpha, interleukin-6, and macrophage inflammatory protein-2), and PGE(2). The degree of lung inflammation was scored on hematoxylin-and-eosin-stained sections. PGHS-1 and PGHS-2 protein levels were determined by immunoblotting. All mice exhibited increased PenH and methacholine responsiveness after LPS exposure; however, these changes were much more pronounced in PGHS-1(-/-) and PGHS-2(-/-) mice relative to WT mice (P < 0.05). There were no significant differences in inflammation as assessed by BAL fluid (BALF) cells or lung histology between the genotypes despite reduced BALF cytokines/chemokines and PGE(2) in PGHS-1(-/-) and PGHS-2(-/-) mice relative to WT mice (P < 0.05). PGHS-2 was upregulated more in PGHS-1(-/-) mice compared with WT mice after LPS exposure. We conclude that: (1) airway inflammation and hyperresponsiveness are dissociated in PGHS-1(-/-) and PGHS-2(-/-) mice exposed to LPS; (2) the balance of PGHS-1 and PGHS-2 is important in regulating the functional respiratory responses to inhaled LPS; and (3) neither PGHS-1 nor PGHS-2 is important in regulating basal lung function or the inflammatory responses of the lung to inhaled LPS.

Topics: Administration, Inhalation; Animals; Bronchoalveolar Lavage Fluid; Chemokines; Cyclooxygenase 1; Cyclooxygenase 2; Cytokines; Dinoprostone; Disease Models, Animal; Female; Isoenzymes; Leukotriene B4; Lipopolysaccharides; Lung; Male; Membrane Proteins; Mice; Mice, Inbred Strains; Mice, Mutant Strains; Pneumonia; Prostaglandin-Endoperoxide Synthases; Proteins; Up-Regulation

A novel series of heteroarylmethoxyphenylalkoxyiminoalkylcarboxylic acids was studied as leukotriene biosynthesis inhibitors. A hypothesis of structure-activity optimization by insertion of an oxime moiety was investigated using REV-5901 as a starting point. A systematic structure-activity optimization showed that the spatial arrangement and stereochemistry of the oxime insertion unit proved to be important for inhibitory activity. The promising lead, S-(E)-11, inhibited LTB(4) biosynthesis in the intact human neutrophil with IC(50) of 8 nM and had superior oral activity in vivo, in a rat pleurisy model (ED(50) = 0.14 mg/kg) and rat anaphylaxis model (ED(50) = 0.13 mg/kg). In a model of lung inflammation, S-(E)-11 blocked LTE(4) biosynthesis (ED(50) of 0.1 mg/kg) and eosinophil influx (ED(50) of 0.2 mg/kg). S-(E)-11 (A-93178) was selected for further preclinical evaluation.

Topics: Acrylic Resins; Anaphylaxis; Animals; Anti-Allergic Agents; Anti-Inflammatory Agents, Non-Steroidal; Ascitic Fluid; Granuloma; Humans; In Vitro Techniques; Leukotriene B4; Male; Mice; Neutrophils; Pleuropneumonia; Pneumonia; Quinolines; Rats; Stereoisomerism; Structure-Activity Relationship

Organic dust toxic syndrome (ODTS) is associated with inhalation of high concentrations of organic materials and is a noninfectious illness characterized by fever, malaise, myalgia, and neutrophilic inflammation of the lower respiratory tract. Studies in our laboratory of fungi in fresh lumber have demonstrated that yeasts may predominate and have raised the issue of potential exposure of sawmill workers to yeasts. Zymosan, a cell wall preparation from Saccharomyces cerevisiae, is a potent stimulator of alveolar macrophages (AM). In the present study, preparations from the cell walls of Pichia fabianii, Candida sake, Trichosporon capitatum, Rhodotorula glutinis, and Cryptococcus laurentii were compared with zymosan and beta-1,3-glucan for their ability to stimulate AM and activate complement. All species activated complement. P. fabianii, C. sake, T. capitatum, R. glutinis, C. laurentii, as well as zymosan and glucan, stimulated superoxide anion and leukotriene B4 production in a dose-dependent fashion, but R. glutinis and C. laurentii were much less active. Zymosan, glucan, P. fabianii, and R. glutinis treatment of AM resulted in increased phagocytosis of labeled sheep RBCs, whereas there was no effect with C. sake or C. laurentii and T. capitatum significantly inhibiting phagocytosis. These results suggest that exposure to high concentrations of yeast could provoke pulmonary inflammation resulting in an episode of ODTS.

Topics: Agricultural Workers' Diseases; Animals; Dose-Response Relationship, Drug; Dust; Leukotriene B4; Lung; Macrophages, Alveolar; Phagocytosis; Pneumonia; Rats; Rats, Sprague-Dawley; Sheep; Superoxides; Syndrome; Tumor Necrosis Factor-alpha; Yeasts; Zymosan

The acute phase protein, C-reactive protein (CRP), can increase more than a thousandfold during acute inflammatory states, and it is known to modulate neutrophil-mediated inflammatory responses. We have previously shown that CRP inhibits chemotaxis of C5a-stimulated neutrophils in vitro and that rabbits with elevated CRP blood levels exhibit diminished pulmonary vascular permeability and neutrophil infiltration in a model of alveolitis. To study the effect of CRP on alveolitis induced by different chemoattractants, transgenic mice capable of expressing rabbit CRP in a dietary-inducible fashion were treated with inflammatory doses of the chemoattractants. Intratracheal installation of FMLP (8 x 10(-10) mol), LTB4 (2 x 10(-11) mol), or IL-8 (5 x 10(-12) mol) in normal CF1 mice resulted in significant (p<0.05) influx of neutrophils and protein into the alveolar space. Transgenic mice with elevated plasma levels of CRP showed significantly (p<0.05) diminished infiltration of neutrophils into bronchoalveolar lavage fluid (BALF) and significant reduction in BALF protein compared with that in normal mice. Rabbit CRP (10 to 500 micrograms/ml) inhibited in vitro neutrophil chemotaxis in a concentration-dependent fashion when stimulated by the various chemoattractants examined. These data show that rabbit CRP can modify both in vivo and in vitro neutrophil responses to several classes of chemoattractants and that CRP has a significant protective effect in alveolitis by reducing neutrophil influx and protein leakage into the lung.

Topics: Animals; Bronchoalveolar Lavage Fluid; C-Reactive Protein; Capillary Permeability; Cell Movement; Chemotactic Factors; Chemotaxis, Leukocyte; Complement C5a; Disease Models, Animal; Dose-Response Relationship, Drug; Humans; Interleukin-8; Leukotriene B4; Lung; Mice; Mice, Inbred Strains; Mice, Transgenic; N-Formylmethionine Leucyl-Phenylalanine; Neutrophils; Pneumonia; Proteins; Pulmonary Alveoli; Rabbits

Sipid mediators of inflammation have been implicated in the pathogenesis of Pseudomonas aeruginosa (PA) related pulmonary damage in patients with cystic fibrosis. We studied the role of these mediators in a rat model of PA endobronchitis using essential fatty acid deficient (EFAD) animals. Whole blood from EFAD animals produced significantly less leukotriene B4 (LTB4) and hydroxyheptadecatrienoic acid when stimulated ex vivo than did whole blood from control animals (p less than 0.005). Similarly, lung lavage fluid from EFAD animals infected with PA contained less LTB4 and thromboxane B2 (TXB2) than that from control animals. Despite these differences, cellular infiltration of airways in response to PA infection was virtually identical in animals from the regular diet and the EFAD groups. Both EFAD and control animals had a significant increase in white blood cells (WBC) in lung lavage fluid at 1, 3 and 6 days following infection with PA when compared to animals receiving sterile beads. Localized areas of consolidation and nodularity were grossly evident in the lungs of all PA infected animals irrespective of their ability to generate the lipid inflammatory mediators. Microscopic examination of lung sections demonstrated similar changes in all infected animals. We conclude that LTB4 and TXB2 production occurs early in the course of PA pulmonary infection in rats. This early rise in lipid mediators is temporally associated with an influx of WBC into the airways. However, attenuation of eicosanoid production by use of an EFAD diet does not lead to a reduction in the inflammatory response to PA infection.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Animals; Bronchoalveolar Lavage Fluid; Dietary Fats, Unsaturated; Eicosanoids; Fatty Acids, Essential; Fatty Acids, Unsaturated; Inflammation; Leukotriene B4; Male; Pneumonia; Pseudomonas Infections; Rats; Rats, Inbred Strains; Thromboxane B2

Inhalation of silicates induces a variety of lung diseases in humans. The molecular mechanism(s) by which these dusts cause disease is not known. Because several naturally occurring mineral oxides have large amounts of transition metal ions on their surfaces, we tested the hypothesis that surface complexation of iron may be an important determinant of their ability to induce disease. Silica, crocidolite, kaolinite, and talc complexed considerable concentrations of Fe3+ onto their surfaces from both in vitro and in vivo sources. The potential biological importance of iron complexation was assessed by examining the relationship between surface [Fe3+] and the ability of silicates to mediate oxidative degradation of deoxyribose in vitro, induce a respiratory burst and elicit leukotriene B4 (LTB4) release by alveolar macrophages (AM) in vitro, and cause acute alveolitis after intratracheal insufflation. For these studies, three varieties of silicate dusts were used: iron-loaded, wetted (unmodified), and deferoxamine-treated to remove Fe3+. The ability of silicates to catalyze oxidant generation in an ascorbate/H2O2 system in vitro, to trigger respiratory burst activity and LTB4 release by AM, and to induce acute lung inflammation in the rat all increased with surface complexed Fe3+. The results of these studies suggest that surface complexation of iron may be an important determinant in the pathogenesis of disease after silicate exposure.

Topics: Adsorption; Animals; Bronchoalveolar Lavage Fluid; Deferoxamine; Dust; Iron; Leukotriene B4; Macrophages, Alveolar; Male; Minerals; Oxygen Consumption; Pneumonia; Rats; Rats, Sprague-Dawley; Reactive Oxygen Species; Silicic Acid; Silicon Dioxide; Surface Properties

High-pressure liquid chromatography was used to measure the blood content of lipoxygenase metabolites (LM) of arachidonic acid: leukotriene B4 (LTB4) and hydroxyeicosatetraene acids (5 HETE, 12 HETE, 15 HETE) in 65 patients with acute pneumonia (AP) of mild gravity (group 1) and of medium gravity (group 2), in 23 patients with acute bronchitis (AB), and in 15 normal male persons aged 18 to 20 years. In all the examined, the zonal pulmonary blood flow was measured by regional rheopulmonography. External respiratory function (ERF) was also determined together with the recording of the flow-volume loop. At the height of AP and AB, all the patients demonstrated an increase of LM in the blood, with the maximum LM content being recorded in group 2. During convalescence, AB and AP patients of group 1 manifested normalization of the majority of the parameters. In group 2, they significantly exceeded the control level. 5 and 15 HETE had the closest correlations with the blood flow parameters, whereas LTB4 and 12 HETE had less intensive correlations. The influences of LM such as 5 and 15 HETE on the pulmonary blood flow were associated with deterioration of the blood content of the lungs and venous return, the action of LTB4 was coupled with venous congestion formation, that of 12 HETE with the rise of vascular resistance. Close negative correlations of LTB4 and 5 HETE with the majority of ERF parameters indicate that they are important factors in the pathogenesis of restrictive and obstructive ventilatory disorders.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Acute Disease; Adolescent; Adult; Arachidonic Acid; Arachidonic Acids; Bronchitis; Humans; Hydroxyeicosatetraenoic Acids; Leukotriene B4; Lipoxygenase; Male; Pneumonia; Pulmonary Circulation; Respiratory Mechanics

The influx of neutrophils into the lung is a prominent feature in patients with bacterial pneumonia. Since neutrophils migrate in response to chemotactic factors, chemotactic activity was evaluated in bronchoalveolar lavage (BAL) fluid obtained from 12 patients with bacterial pneumonia and ten normal control subjects. Chemotactic activity was greatly elevated in the BAL fluid of the pneumonia patients compared with control subjects (p less than 0.01). To partially characterize the chemotactic factors present in the lavage fluid of the patient group, molecular sieve chromatography was performed on the lavage fluid, and at least three peaks of chemotactic activity were identified. Since the molecular weight of the smaller peaks approximated the molecular weight of two known chemotactic factors, C5a and leukotriene B4, these factors were measured in lavage fluid by radioimmunoassay. C5a was detectable in none of the normal subjects but was detectable in four of 14 BAL samples obtained from the patients. Leukotriene B4 was detectable in all subjects and was significantly elevated in the pneumonia patients (552 +/- 95 vs 81 +/- 16 pg/ml, p less than 0.01). These findings demonstrate that elevated neutrophil chemotactic activity is present in the lungs of patients with bacterial pneumonia and suggest that C5a and leukotriene B4 may account, at least in part, for this increase.

Topics: Adolescent; Aged; Bacterial Infections; Bronchoalveolar Lavage Fluid; Bronchoscopy; Chemotaxis, Leukocyte; Chromatography, Gel; Complement C5; Complement C5a; Female; Humans; Leukocyte Count; Leukotriene B4; Male; Middle Aged; Neutrophils; Pneumonia

Leukotriene B4 (LTB4) is a lipoxygenase product of arachidonic acid that has potent chemotactic activity for blood leukocytes. To assess the potential role of LTB4 in lung inflammatory responses, we investigated the production of LTB4 by human alveolar macrophages and determined its chemotactic activity for lung and blood phagocytes in vitro and in vivo. Human alveolar macrophages were stimulated with the calcium ionophore A23187 (10 micrograms/ml), and lipoxygenase products in the supernatants were isolated by high-performance liquid chromatography. Leukotriene B4 was the predominant arachidonate lipoxygenase product from the alveolar macrophages of 2 nonsmokers (17.3 +/- 2.7 ng/10(6) cells) and 3 of 4 smokers (23.4 +/- 14.8 ng/10(6) cells). Alveolar macrophages produced more LTB4 than did similarly treated peripheral blood neutrophils. Stimulated alveolar macrophages also produced 5-hydroxyeicosatetraenoic acid (HETE) and 2 isomers of LTB4: 5-(S),12-(R)-6-trans-LTB4 and 5-(S),12-(S)-6-trans-LTB4. Leukotriene B4 showed little chemotactic activity for alveolar macrophages in vitro and was a more potent chemoattractant for peripheral blood neutrophils than for monocytes (p less than 0.05). When instilled into the airways of anesthetized rats, LTB4 was less potent as an attractant for neutrophils and mononuclear cells than either zymosan-activated serum or bacterial-derived chemotactic factors. Leukotriene B4 production by alveolar macrophages may provide a mechanism by which phagocytes are recruited to the human lung during inflammatory processes.

Topics: Adult; Aged; Animals; Cell Movement; Chemotaxis; Female; Humans; Leukotriene B4; Macrophages; Male; Middle Aged; Phagocytes; Pneumonia; Pulmonary Alveoli; Rats; Rats, Inbred Strains; Smoking