Protective effect of nedocromil sodium on the IL1-induced release of GM-CSF from cultured human bronchial epithelial cells

The Use of Antiallergic and Antiasthmatic Drugs in Viral Infections of the Upper Respiratory Tract

Despite their frequency, upper respiratory tract infections (URTIs) constitute an area with few, if any, effective treatment remedies. Asthma and airway allergies share similar pathogenetic mechanisms to URTIs and it is not surprising, therefore, that agents used to treat allergic disorders have also been studied in URTIs. Their possible effects, limitations and hypothetical modes of action in URTIs are reviewed. In controlled clinical trials of satisfactory scientific standard, symptom reductions in both experimental rhinovirus infections and natural colds have occurred with topical anticholinergics, oral antihistamines and topical chromones. Future treatment alternatives for URTIs may include the intranasal anticholinergic ipratropium bromide, new nonsedating antihistamines and sodium cromoglycate (cromolyn sodium). The latter has a record of safety and an absence of adverse effects that would make it an attractive alternative for this common but not particularly serious condition in otherwise healthy individuals.

The role of airway epithelial cells in response to mycobacteria infection

Airway epithelial cells (AECs) are part of the frontline defense against infection of pathogens by providing both a physical barrier and immunological function. The role of AECs in the innate and adaptive immune responses, through the production of antimicrobial molecules and proinflammatory factors against a variety of pathogens, has been well established. Tuberculosis (TB), a contagious disease primarily affecting the lungs, is caused by the infection of various strains of mycobacteria. In response to mycobacteria infection, epithelial expression of Toll-like receptors and surfactant proteins plays the most prominent roles in the recognition and binding of the pathogen, as well as the initiation of the immune response. Moreover, the antimicrobial substances, proinflammatory factors secreted by AECs, composed a major part of the innate immune response and mediation of adaptive immunity against the pathogen. Thus, a better understanding of the role and mechanism of AECs in response to mycobacteria will provide insight into the relationship of epithelial cells and lung immunocytes against TB, which may facilitate our understanding of the pathogenesis and immunological mechanism of pulmonary tuberculosis disease.

Effect of budesonide and nedocromil sodium on IL-6 and IL-8 release from human nasal mucosa and polyp epithelial cells

We investigated the effect of budesonide and nedocromil sodium on the secretion of IL-6 and IL-8 by cultured epithelial cells from healthy nasal mucosa and nasal polyps. Human epithelial cell conditioned media was generated with fetal calf serum (FCS) in the presence or absence of budesonide and/or nedocromil sodium. Budesonide inhibited FCS-induced IL-6 and IL-8 release in a dose-dependent manner. The IC25 (25% inhibitory concentration) of budesonide on IL-6 release was higher in nasal polyp than in nasal mucosa epithelial cells (34 nM vs. 200 pM). The IC25 of budesonide on IL-8 release was higher in nasal mucosa than in nasal polyps (145 pM vs. 4 pM). Nedocromil sodium caused a dose-related inhibitory effect on IL-8 release from nasal mucosa (IC25, 207 nM), while it only had a significant effect in nasal polyps at 10(-5) M. Nedocromil sodium had no effect on IL-6 release. The inhibitory effect of budesonide was higher than that of nedocromil sodium on both nasal polyps and nasal mucosa. Budesonide and nedocromil sodium may exert their anti-inflammatory action in the respiratory mucosa by modulating the secretion of IL-6 and IL-8. The different effect of budesonide and nedocromil sodium on IL-6 and IL-8 release may be explained by differences in the mechanisms which regulate the upregulation of these cytokines in inflammatory responses.

Inhibition of GM-CSF secretion by topical corticosteroids and nedocromil sodium. A comparison study using nasal polyp epithelial cells

Nasal epithelial cells maintain eosinophil survival by secreting granulocyte/macrophage colony-stimulating factor (GM-CSF). Corticosteroids antagonize eosinophil viability induced by GM-CSF. We investigated the effect of topical corticosteroids and nedocromil sodium on the release of GM-CSF from nasal polyp epithelial cells. Epithelial cells were obtained from 19 patients undergoing nasal polypectomy and cultured. After reaching confluence, cultured cells were stimulated with 10% foetal calf serum in the absence and presence of four topical corticosteroids and nedocromil sodium for 48 h. GM-CSF was measured by enzyme linked immunosorbent assay (ELISA). Fluticasone propionate was the most potent inhibitor of GM-CSF release (IC25 = 46 pM) closely followed by budesonide (IC25 = 4 nM), beclomethasone dipropionate (IC25 = 40 nM) and triamcinolone acetonide (IC25 = 75 nM). Nedocromil sodium had no effect on GM-CSF release. We conclude that the effect of topical steroids on reducing eosinophil infiltration in nasal polyps may be due in part to downregulation, among other cytokines, of epithelial GM-CSF production which prolongs eosinophil viability. Quantitatively, fluticasone propionate inhibited GM-CSF production more potently than budesonide, beclomethasone dipropionate and triamcinolone acetonide.

In vivo induction and regulation of interleukin-8-like chemokine GRO/CINC-1 in rat middle ear

Interleukin-8 possesses chemotactic-activating properties toward neutrophils, and may contribute to the pathogenesis of middle ear inflammation. GRO/CINC-1 is a rat chemokine with structural and functional homology to human interleukin-8, the induction and regulation of which in the middle ear cavity in vivo remains to be established. The production of GRO/CINC-1 in middle ear lavage and gene expression in the middle mucosa was investigated using topical inoculation with lipopolysaccharide (LPS) in the rat in vivo model. GRO/CINC-1 in middle ear lavage showed time- and dose-dependent production under LPS stimulation. The peak of the GRO/CINC-1 production was reached by 4 h after LPS 1 h exposure, whereas the level of production subsequently returned to the level without LPS stimulation at 8 h after LPS stimulation. The topical corticosteroid perfusion in the middle ear after LPS stimulation significantly reduced the production of GRO/CINC-1 in the middle ear cavity compared with that without corticosteroid. At the time of peak production, the expression of GRO/CINC-1 mRNA, evaluated using the polymerase chain reaction, was considerable in the middle ear mucosa. This investigation of the characteristics of interleukin-8-like cytokine in the middle ear cavity using a rat in vivo model has extended the functional concept of chemokines at the initial stage in otitis media.

RU 41740 (Biostim) stimulates the production of granulocyte macrophage colony-stimulating factor and interleukin-8 by human bronchial epithelial cells in vitro

1. In this study, we observed the effects of RU 41740 (Biostim) on the production of granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin-8 (IL-8) in human bronchial epithelial cells in vitro. 2. Cytokine production was assessed by enzyme-linked immunosorbent assay. 3. We report that epithelial cells spontaneously released both cytokines and that RU 41740 induced a significant increase in production of IL-8 and GM-CSF. 4. This is the first observation of a stimulatory effect of an immunostimulating compound used in humans on cytokine production by epithelial cells.

Antihistamines and production of granulocyte-macrophage colony-stimulating factor and interleukin-8 by human bronchial epithelial cells in vitro: evaluation of the effects of loratadine and cetirizine

1. In this study, we compared the effects of two antihistamine drugs on the production of granulocyte-macrophage colony-stimulating factor and interleukin-8 by human bronchial epithelial cells in vitro. 2. Cytokine production was assessed by the use of an enzyme-linked immunosorbent assay. 3. Epithelial cells spontaneously released both cytokines and tumor necrosis factor alone induced a significant increase in this production but loratadine and cetirizine had no effect at the various concentrations studied. 4. The antihistamines have no effect and this suggests that histamine plays no role in cytokine production under these conditions.

Clinical implications of the pharmacological profile of Tilarin

The pharmacological activity of nedocromil sodium is extensive and the compound should affect a variety of inflammatory processes by preventing activation of the involved cells or blocking release of their mediators. Some in vitro actions of nedocromil sodium are particularly relevant to the mechanisms of allergic rhinitis, and the response of the nasal epithelium to pollutants such as ozone. The effects of nedocromil sodium on mucosal mast cells, eosinophils, sensory nerves and nasal epithelial cells can each be linked to its potential clinical effectiveness by our own biopsy studies from patients with active allergic rhinitis. Nedocromil sodium has been shown to modulate production of a number of powerful cytokines, such as GM-CSF and TNF alpha, which are produced by the human nasal epithelium, as well as by involved inflammatory cells and lymphocytes, and which orchestrate the inflammatory response to allergen or to pollutant provocation. So, in addition to inhibiting activated mast cells and eosinophils, nedocromil sodium acts on the nasal epithelium itself to prevent further accumulation of these cells and thus to break the inflammatory chain of events. On this evidence of its preclinical activity, nedocromil sodium promises to become a very useful topical treatment for allergic rhinitis.

Mast cells modulate acute ozone-induced inflammation of the murine lung

We hypothesized that mast cells modulate lung inflammation that develops after acute ozone (O3) exposure. Two tests were done: (1) genetically mast-cell-deficient (WBB6F1-W/Wv, WCB6F1-SI/SId) and bone-marrow-transplanted W/Wv mice were exposed to O3 or filtered air, and the inflammatory responses were compared with those of mast-cell-sufficient congenic mice (WBB6F1-(+)/+, WCB6F1-(+)/+); (2) genetically O3-susceptible C57BL/6J mice were treated pharmacologically with putative mast-cell modulators or vehicle, and the O3-induced inflammatory responses were compared. Mice were exposed to 1.75 ppm O3 or air for 3 h, and lung inflammation was assessed by bronchoalveolar lavage (BAL) 6 and 24 h after exposure. Relative to O3-exposed W/Wv and SI/SId mice, the mean numbers of lavageable polymorphonuclear leukocytes (PMNs) and total BAL protein concentration (a marker of permeability) were significantly greater in the respective O3-exposed normal congenic +/+ mice (p < 0.05). Mast cells were reconstituted in W/Wv mice by transplantation of bone marrow cells from congenic +/+ mice, and O3-induced lung inflammation was assessed in the mast-cell-replete W/Wv mice. After O3 exposure, the changes in lavageable PMNs and total protein of mast-cell-replete W/Wv mice were not different from age-matched normal +/+ control mice, and they were significantly greater than those of sham-transplanted W/Wv mice (p < 0.05). Genetically susceptible C57BL/6J mice were pretreated with a mast-cell stabilizer (nedocromil sodium), secretagogue (compound 48/80), or vehicle, and the mice were exposed to O3.(ABSTRACT TRUNCATED AT 250 WORDS)

Nedocromil sodium. An updated review of its pharmacological properties and therapeutic efficacy in asthma

Nedocromil sodium, the disodium salt of a pyranoquinoline dicarboxylic acid, has anti-inflammatory properties in vitro, in animal models of asthma, and in humans, as evidenced by inhibition of inflammatory cell activation and mediator release, early and late allergen-induced bronchoconstriction and airway hyperresponsiveness. Recent therapeutic trials confirm the safety and efficacy of inhaled nedocromil sodium as adjunctive therapy in adult patients whose asthma is not adequately controlled by beta-agonists alone. Nedocromil sodium has also been shown to improve symptoms when added to existing treatment with methylxanthines and corticosteroids. Some studies show nedocromil sodium to be successful replacement therapy for methylxanthines, in addition to enabling a modest reduction in inhaled corticosteroids in some patients. Thus, nedocromil sodium may be suitable in patients with asthma as an adjunct to existing therapy, as an alternative to regularly administered oral and inhaled beta-agonists and oral methyl-xanthines, and potentially, to low dose inhaled corticosteroids as maintenance therapy in patients with mild to moderate asthma being considered for corticosteroid therapy.