Regular albuterol or nedocromil sodium — effects on airway subepithelial tenascin in asthma

AbstractBoth albuterol and nedocromil sodium have been recognized to possess certain anti-inflammatory properties. However, there are no data on the impact of these drugs on the pathophysiology of the bronchial extracellular matrix in asthma characterized by enhanced tenascin (Tn) expression, known to occur proportional to the severity of asthma. This paper reports data from a morphometric study on the effects of regular treatment with inhaled albuterol or nedocromil sodium on the extent of bronchial subepithelial deposition of Tn, collagen types III, IV, and VII and mucosal infiltration with macrophages.Thirty-two patients (14 women) with chronic asthma, aged 38·7 years (median) with a median forced expiratory volume in 1 sec (FEV1) of 74·4% predicted, were selected to undergo fibre-optic bronchoscopy with bronchial biopsies before and after 12 weeks of treatment with either inhaled albuterol 0·2 mg or nedocromil sodium 4 mg four times daily according to a double-blind protocol. Cryostat sections of the biopsy specimens were studied by indirect immunostaining techniques using monoclonal antibodies and computer-assisted quantitative image analysis.Albuterol treatment significantly reduced the median thickness of subepithelial Tn expression from 9·7 to 6·3 μm (P=0·023) and macrophage numbers in the epithelium (P=0·034), lamina propria (P=0·039) and entire mucosa (P=0·033), whereas nedocromil sodium had no effect. Expression of the collagen types was not affected by either treatment. There was no identifiable statistical difference between the two treatments for any of the outcome variables measured. Nevertheless, the results demonstrate that even a short-acting β2-agonist may exert anti-inflammatory potential sufficient to interfere with the basic mechanisms of asthma as shown by reduction of subepithelial Tn content and mucosal macrophage count

Potentiative effects of neutral proteinases in an inflamed lung: Relationship of neutrophil procollagenase (proMMP-8) to plasmin, cathepsin G and tryptase in bronchiectasis in vivo

Sepper R, Konttinen YT, Buo L, et al. Potentiative effects of neutral proteinases in an inflamed lung: Relationship of neutrophil procollagenase (proMMP-8) to plasmin, cathepsin G and tryptase in bronchiectasis in vivo. EUROPEAN RESPIRATORY JOURNAL. 1997;10(12):2788-2793.We attempted to study the possible relationships between neutrophiltype procollagenase/pro-matrix metalloproteinase (MMP-8) and the serine proteinases plasmin, cathepsin G and tryptase in bronchiectasis. The presence of the plasmin/piasminogen system and plasmin-, cathepsin G-and tryptase-like activities were compared to the activity of endogenously activated MMP-8 in bronchoalveolar lavage (BAL) fluid in 38 bronchiectasis patients and in 14 healthy controls by means of immunohistochemistry, Western-blot and substratebased functional assays, In contrast to cathepsin G-and tryptase-like activities, the plasmin/plasminogen activator system in BAL fluid was observed to have a relatively weak activation stage and no correlation with disease severity, Neither plasmin-like activities nor concentrations of plasminogen activators from the bronchiectatic patients differed significantly from the values of health. controls, Immunolocation of plasminogen activator inhibitor-1 showed a marked, but not significant, increase in bronchiectatic lung as compared to controls, In contrast to cathepsin G-and tryptase-like activities,,vith their strong and significant correlation with endogenously activated collagenase (r=0.9; p=0.0001; and r=0.6; p=0.03, respectively), no correlations were observed between plasmin-like and endogenously activated collagenase(r=0.3; p=0.2) in bronchiectasis. These findings suggest that cathepsin G-and tryptase-like activities may act as potent pro-matrix metalloproteinase-8 activators in patients with bronrhiectasis, whereas the plasminogen activator/plasmin cascade was shown to be down-regulated