Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Leukotrienes (LT) and platelet-activating factor (PAF) are synthesized by several lung cells, including alveolar macrophages (AM), and may contribute to the airway inflammation that characterizes asthma. Phospholipases A2 (PLA2) can release arachidonic acid and lysophosphatidylcholine (lysoPC), precursors for leukotriene and PAF synthesis, respectively, from membrane phospholipids. The present study sought to determine the extent to which this common initial step contributes to leukotriene and PAF synthesis in rat AM. AM were obtained by lung lavage, cultured, and exposed to one or more of the following: PAF, zileuton (5-lipoxygenase inhibitor), Ro 25-4331 (dual PLA2 inhibitor), and either A23187 (Cal) or zymosan. The following measurements were made: LTB4 synthesis, PAF synthesis, and PLA2 activity. CaI stimulation increased PAF synthesis 3-fold (P < 0.001), LTB4 synthesis 20-fold (P < 0.001), and PLA2 activity 52% (P < 0.001). Incubation with PAF (2.5 microM) for 10 min decreased basal LTB4 synthesis 33% (P < 0.001), but it had no effect on basal PAF synthesis or PLA2 activity. The same dose of PAF (2.5 microM) decreased CaI-stimulated PAF synthesis 40% (P < 0.02). After CaI stimulation of PAF-pretreated cells, a relationship was found between PAF-induced changes in PLA2 activity and LTB4 synthesis (r = 0.68; P < 0.001) but not between changes in PLA2 activity and PAF synthesis. Zileuton (1 microM) decreased basal and CaI-stimulated LTB4 synthesis 50% (P < 0.02), and 80% (P < 0.002) respectively, but it did not alter PAF synthesis.
Am J Respir Cell Mol Biol 1995 Jun
PMID:Differential regulation of leukotriene and platelet-activating factor synthesis in rat alveolar macrophages. 776 33

Severe chronic asthma is associated with structural changes in the airway wall including airway smooth muscle (ASM) hyperplasia. We have used cultured ASM cells isolated from rabbit trachealis as a model with which to investigate possible mechanisms of accelerated ASM growth to mitogenic stimuli. To elucidate the role that protein kinase C (PKC)- and protein tyrosine kinase (PTK)-dependent pathways play in the control of ASM mitogenesis, we have investigated the effect of reportedly selective inhibitors of PKC (3-[1-[3-(amidinothio)propyl]-3-indolyl]-4-(1-methyl-3-indolyl)-1H - pyrrole-2,5-dionemethanesulfonate [Ro31-8220] and 3-[1-(aminopropyl)indolyl]-4-(1-methyl-3-indolyl)-1H-pyrrole-2,5-dione acetate [Ro31-7549]) and PTK (alpha-cyano-3-ethoxy-4-hydroxy-5-phenylthiomethylcinnamamide [ST638]) on partially purified PKC, fetal calf serum (FCS)-stimulated protein phosphotyrosine content and on FCS-induced proliferation. Anion-exchange chromatography of lysed ASM cells resolved two peaks of Ca(2+)-activated, phospholipid-dependent PKC activity and one peak of Ca(2+)- and phospholipid-independent PKC activity. The selective PKC inhibitors, Ro31-8220 and Ro31-7549, abolished the main peak of PKC activity and the Ca(2+)- and phospholipid-independent peak that co-eluted with the main peak. The inhibition was dependent on the concentration of ATP in the reaction cocktail (IC50: 10 microM ATP: Ro31-8220 0.026 microM, Ro31-7549 0.073 microM; 100 microM ATP: Ro31-8220 0.065 microM, Ro31-7549 0.271 microM), consistent with these compounds inhibiting PKC at the ATP-binding site. Ro31-8220 was more potent (2- to 3-fold) than Ro31-7549. Concentrations of each inhibitor that produced maximal inhibition of the pooled kinase activity also abolished the second peak of Ca(2+)-dependent activity. The PTK inhibitor, ST638, had no effect on the kinase activity associated with any of the Ca(2+)-dependent or -independent peaks that eluted from the column. ST638, however, maximally inhibited FCS-stimulated PTK activity (IC50 25 microM). FCS-stimulated PTK was also inhibited by Ro31-8220 (IC50 0.15 microM), but only by 60%, revealing an Ro31-8220-insensitive component to the response. The ability of each protein kinase inhibitor to inhibit proliferation was also studied using four independent indices of ASM cell growth and division: 3-(4,5-dimethylthiazol-2-yl)2,5-diphenyl tetrazolium bromide (MTT) dye conversion, Coomassie blue protein determination, hemacytometer cell counts, and DNA synthesis. Ro31-8220 and Ro31-7549 produced concentration-dependent inhibition of FCS-stimulated proliferation of growth-arrested ASM cells.(ABSTRACT TRUNCATED AT 400 WORDS)
Am J Respir Cell Mol Biol 1995 Feb
PMID:Inhibition of fetal calf serum-stimulated proliferation of rabbit cultured tracheal smooth muscle cells by selective inhibitors of protein kinase C and protein tyrosine kinase. 786 14

T helper 2 (Th2)-like cytokines are thought to play a crucial role in the pathogenesis of airway inflammation in atopic asthma, leading to bronchial hyperresponsiveness. To investigate the role of the principal Th2 cytokine interleukin-4 (IL-4) in asthma, we examined the allergen-induced changes in airway morphology and bronchial responsiveness (BR) in an in vivo mouse model. C57BL/6 mice were actively sensitized to ovalbumin (OVA) and exposed daily to aerosolized OVA or saline (SAL) for 7 days. Twenty-four hours after the last allergen exposure, total and differential counts of bronchoalveolar lavage cells revealed a significant increase of eosinophils and lymphocytes in OVA-exposed immunized mice compared with SAL-exposed animals. In IL-4-deficient (IL-4-/-) mice, treated in the same way, there were substantially fewer eosinophils in bronchoalveolar lavage compared with wild-type mice. Allergen exposure of actively sensitized wild-type mice induced a significant increase of BR to carbachol and to serotonin compared with SAL-exposed mice. In contrast, OVA exposure of immunized IL-4-/- mice did not augment BR to serotonin compared with SAL-challenged IL-4-/- mice. In conclusion, these data indicate that repeated allergen exposure in sensitized mice induces airway inflammation and bronchial hyperresponsiveness, and that IL-4 plays a predominant role in the pathogenesis of both phenomena.
Am J Respir Cell Mol Biol 1995 Mar
PMID:Allergen-induced airway inflammation and bronchial responsiveness in wild-type and interleukin-4-deficient mice. 787 90

Alveolar macrophages (AM) play a regulatory role in asthma. AM from asthmatics are activated, release increased amounts of cytokines, and express higher levels of the low affinity receptor for IgE (Fc epsilon RIIb/CD23b) and receptors for adhesion molecules. The bronchial microenvironment may modulate the phenotypic and functional characteristics of AM. On AM from normal subjects, the effects of histamine were studied on the expression of adhesion molecules (LFA-1, ICAM-1) and CD23b as well as on the release of fibronectin. The expression of LFA-1, ICAM-1, and CD23b was examined by immunocytochemistry using the alkaline phosphatase-anti-alkaline phosphatase technique. The expression of CD23b mRNA was studied by in situ hybridization. The release of fibronectin was measured by enzyme immunoassay. We found that histamine induced in a dose- and time-dependent fashion a significant increase of AM expressing the three membrane markers and a significant increase in the release of fibronectin. The maximum effect of histamine was observed after an incubation of 12 to 24 h and a dose of 1 microM. The histamine effects were specific, since they were significantly inhibited by an H1-blocker, pyrilamine, used at a concentration of 10 microM. The effect of an H2-blocker (ranitidine, concentration of 10 microM) was inconstant. Cycloheximide blocked the histamine effects, suggesting that it requires protein synthesis for its action. This study provides an in vitro model of cellular interaction between mast cells and AM, which might be relevant in the airway inflammation in asthma.
Am J Respir Cell Mol Biol 1994 Oct
PMID:Phenotypic and functional modulation of normal human alveolar macrophages by histamine. 791 13

We have shown that hyperoxic exposure of immature rats induces airway smooth muscle layer thickening and cell turnover parallel to that found in the airways of patients with bronchopulmonary dysplasia and chronic, severe asthma. We hypothesized that reactive oxygen species could promote the observed airway remodeling by directly stimulating signal transduction pathways that regulate cell growth. To test this hypothesis in cultured cells, we assessed the effects of hydrogen peroxide (H2O2) on mitogen-activated protein (MAP) kinase activation in bovine tracheal myocytes. The MAP kinases are a family of 40 to 46 kD cytosolic serine/threonine kinases that participate in the transduction of mitogenic signals to the cell nucleus. Quiescent cells were exposed to H2O2 (25 to 200 microns; 2 to 60 min), after which SDS-PAGE of cell extracts was performed. Western analysis using an anti-MAP kinase antiserum revealed a decrease in the mobility of the 42 and 44 kD MAP kinase bands after H2O2 exposures of 5 to 30 min, reflecting the phosphorylation at threonine and tyrosine residues required for enzymatic activity. MAP kinase activation was demonstrated by kinase renaturation assays, which showed an almost 4-fold increase in 42 and 44 kD MAP kinase activity. Down-regulation of protein kinase C (PKC) with phorbol 12,13-dibutyrate (PDBu) partially reduced H2O2-stimulated MAP kinase activity, suggesting that H2O2 induces MAP kinase activation via both PKC-dependent and PKC-independent pathways. Western analysis using a phosphotyrosine monoclonal antibody revealed increased tyrosine phosphorylation of proteins with approximate molecular weights of 72 and 125 kD after H2O2 exposure, demonstrating that H2O2 can stimulate the tyrosine phosphorylation of multiple cytosolic proteins, including MAP kinase.(ABSTRACT TRUNCATED AT 250 WORDS)
Am J Respir Cell Mol Biol 1994 Nov
PMID:Hydrogen peroxide stimulates mitogen-activated protein kinase in bovine tracheal myocytes: implications for human airway disease. 794 86

Airway inflammation is implicated in the pathogenesis of the airway hyperresponsiveness in asthma. An increased production of inflammatory cell progenitors may contribute to asthmatic airway inflammation. Although the number of circulating inflammatory cell progenitors in asthmatic subjects increases after allergen inhalation, no direct evidence exists for increased bone marrow progenitor production. We examined the effect of allergen inhalation on bone marrow progenitor production in seven dogs that develop allergen-induced airway hyperresponsiveness. The effect of inhaled budesonide, a corticosteroid known to be effective in the treatment of asthma, on allergen-induced bone marrow progenitor production and airway hyperresponsiveness was also examined. Allergen inhalation increased airway responsiveness (P < 0.001) and the number of granulocyte-macrophage colony-forming units (CFU) when cultured with dog serum and either recombinant canine stem cell factor (rcSCF) (P < 0.001) or granulocyte colony-stimulating factor (rcG-CSF) (P = 0.035). Budesonide treatment reduced the allergen-induced increases in airway responsiveness (P = 0.005) and abolished the allergen-induced increases in the numbers of CFU cultured with dog serum and either rcSCF (P < 0.001) or rcG-CSF (P = 0.009). These findings provide the first direct evidence that allergen inhalation increases bone marrow progenitor production and suggest that such increases may contribute to the development of airway hyperresponsiveness in asthma. In addition, the effectiveness of inhaled corticosteroids in asthma may result, in part, from their ability to suppress bone marrow production of inflammatory cells.
Am J Respir Cell Mol Biol 1994 Nov
PMID:Allergen-induced changes in bone marrow progenitors and airway responsiveness in dogs and the effect of inhaled budesonide on these parameters. 794 89

A simple, noninvasive, bias-flow ventilated wholebody plethysmographic technique and noninvasive pulmonary analyzer (Buxco dyspnea monitor) were used to quantitate allergic dyspnea in chronically sensitized freely moving guinea pigs. In this study, the effect of azelastine on aeroallergen-induced dyspnea in allergic guinea pigs was investigated. Aeroallergen challenge produced severe dyspnea which was characterized by a 390% increase in the amplitude of pseudo flow signal, a 93% increase in box pressure (delta P) and a 68% decline in relaxation time; these changes signify a tremendous increase in the effort of breathing. The oral administration of azelastine (1 mg/kg) two hours before aeroallergen provocation significantly inhibited allergic dyspnea in this acute allergic asthma model. This technique permits quantitative measurement of the severity of the airway allergic responses in freely moving guinea pigs.
Res Commun Mol Pathol Pharmacol 1994 Aug
PMID:Azelastine inhibits acute allergic dyspnea in a conscious guinea pig asthma model. 799 65

The pathogenesis of asthma remains unclear. An in vivo murine model of antigen-induced airway hyperreactivity and inflammation was developed to investigate the possibility, suggested by a wealth of descriptive human data, that alterations in immunoregulation are important in the genesis of airway hyperreactivity. A/J mice developed airway hyperreactivity and markedly increased numbers of pulmonary inflammatory cells following intraperitoneal sensitization and intratracheal challenge with sheep red blood cells. Notably, eosinophils were a prominent component of the inflammatory infiltrate. The dependence of these phenomena, both pathologic and functional, on CD4+ T lymphocytes was investigated by in vivo depletion of CD4+ cells using the anti-CD4 mAb GK1.5. When administered before antigen challenge, GK1.5 completely prevented both airway hyperreactivity and the infiltration of eosinophils. This model provides the first direct demonstration of the dependence of airway hyperreactivity upon CD4+ T lymphocytes, and the results are consistent with the possibility that eosinophils are effectors of this response.
Am J Respir Cell Mol Biol 1994 Jun
PMID:Depletion of murine CD4+ T lymphocytes prevents antigen-induced airway hyperreactivity and pulmonary eosinophilia. 800 37

Corticosteroid-resistant (CR) asthma is not caused by altered bioavailability of the administered drug, altered ligand-binding characteristics, or altered nuclear translocation of the activated human glucocorticoid receptor (hGR) complex. We have tested the hypothesis that CR asthma results from a consistent polymorphism in the functionally diverse hGR cDNA using the sensitive screening technique of polymerase chain reaction (PCR) amplification and chemical mutational analysis. Total RNA was extracted from peripheral blood monocytes derived from six corticosteroid-sensitive (CS) and six CR asthmatic subjects. The RNA was reverse transcribed, and overlapping hGR cDNA fragments were amplified by nested PCR. Double-stranded hGR cDNA fragments were hybridized to corresponding 32P-5'-labeled wild-type fragments, chemically modified with osmium and hydroxylamine, and cleaved with piperidine. The resultant cleaved strands were detected by autoradiography. As controls, single base pair mutated hGR cDNA fragments sensitive to hydroxylamine and osmium modification were used. Using this technique, we did not detect any base pair mismatch between the six CS and six CR patients and the corresponding wild-type hGR, despite a 100% detection of control mutations. We conclude that the defect in CR asthma does not lie in the structure of the hGR.
Am J Respir Cell Mol Biol 1994 Jul
PMID:Chemical mutational analysis of the human glucocorticoid receptor cDNA in glucocorticoid-resistant bronchial asthma. 801 37

Increased expression of the intercellular adhesion molecule-1 (ICAM-1) on cells present in the airways has been suggested to play a role in the pathogenesis of asthma by enhancing airway inflammation. We used the monocytic U937 cell line, both undifferentiated and differentiated to a macrophage-like phenotype, and the bronchial epithelial cell line NCI-H292 as cellular model systems for human monocytes/macrophages and bronchial epithelial cells, respectively, and studied the effects of 12-O-tetradecanoyl phorbol-13-acetate (TPA) and dexamethasone on ICAM-1 expression. Both cell lines expressed the ICAM-1 protein constitutively. In addition, TPA- or 1,25-dihydroxyvitamin D3-mediated differentiation of the U937 cell line into a macrophage-like phenotype was associated with increased expression of ICAM-1. In both cell lines, two ICAM-1 mRNA transcripts were found, and expression was stimulated to a similar degree within 1 to 2 h after addition of TPA. In both cell lines, the anti-inflammatory corticosteroid dexamethasone repressed both constitutive and TPA-stimulated ICAM-1 expression, within 3 h of its addition. In the presence of cycloheximide, a marked superinduction of ICAM-1 was observed, while the repressive effect of dexamethasone remained, supporting the hypothesis that dexamethasone acts directly at the transcriptional level.
Am J Respir Cell Mol Biol 1993 Mar
PMID:Glucocorticoid-mediated repression of intercellular adhesion molecule-1 expression in human monocytic and bronchial epithelial cell lines. 809 95


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