Enhanced bronchial expression of extracellular matrix proteins in chronic obstructive pulmonary disease

Remodeling of airways and blood vessels is an important feature in chronic obstructive pulmonary disease (COPD). By using immunohistochemical analysis, we examined bronchial expression patterns of various extracellular matrix (ECM) components such as collagens (subtypes I, III, and IV), fibronectin, and laminin beta2 in patients with COPD (forced expiratory volume in 1 second [FEV1] or=85%; n = 16) and correlated expression data with lung function. Quantitative analysis revealed enhanced levels (P < .01) of total collagens I, III, and IV in surface epithelial basement membrane (SEBM) and collagens I and III in bronchial lamina propria (P < .02) and adventitia (P < .05) in COPD. Distinct and increased (P < .05) vascular expression of fibronectin accounts for intimal vascular fibrosis, whereas laminin beta2 (P < .05) was elevated in airway smooth muscle (ASM). FEV1 values inversely correlated with collagens in the SEBM, fibronectin in bronchial vessels, and laminin in the ASM. Our data suggest that COPD exhibits increased bronchial deposition of ECM proteins that contribute to deteriorated lung function and airway remodelin

Transforming growth factor-<img src='/image/spc_char/beta.gif' border=0>₁ induces angiogenesis <i style="">in vitro</i> via VEGF production in human airway smooth muscle cells

262-269Increase in size and number of bronchial blood vessels as well as hyperaemia are factors that contribute to airway wall remodelling in patients with chronic airway diseases, such as asthma and chronic obstructive pulmonary diseases (COPD). Expression of transforming growth factor 1 (TGF-1), a multifunctional cytokine as well as vascular endothelial growth factor (VEGF), a key angiogenic molecule, has been shown in the inflammed airways in patients with chronic airway diseases. TGF-1 has been implicated in the regulation of extracellular matrix, leading to airway remodelling in patients with chronic airway diseases. However, the role of TGF-1 in regulating VEGF expression in patients with chronic airway diseases, as well as the underlying mechanisms are not yet well established. We investigated whether TGF-1 stimulates VEGF expression in vitro and hence could influence vascular remodelling. Cultured human airway smooth muscle cells (HASMC) were serum deprived for 60 h before incubation with 5ng/ml of TGF-1 for different time points. Control cells received serum-free culture medium. TGF‑1, treatment resulted in time dependent HASMC cell proliferation with maximal values for DNA biosynthesis at 24 h and cell number at 48 h. Northern blot analysis of VEGF mRNA expression showed increased levels in cells treated with TGF-1 for 4 to 8 h. TGF-1 also induced a time-dependent release of VEGF proteins in the conditioned medium after 48 h of treatment. Furthermore, the ability of HASMC-released VEGF proteins to induce human umbilical vein endothelial cells proliferation was inhibited by VEGF receptor antagonist, confirming that TGF-1 induced VEGF was biologically active. We conclude that TGF-1 in addition to an extracellular matrix regulator also could play a key role in bronchial angiogenesis and vascular remodelling via VEGF pathway in asthma. </span

Anti-inflammatory effects of roflumilast in chronic obstructive pulmonary disease (ROBERT): a 16-week, randomised, placebo-controlled trial

BACKGROUND: The clinical effects of roflumilast, a selective phosphodiesterase-4 inhibitor, are well established, but little is known about the anti-inflammatory mechanisms underlying the drug's efficacy. The aim of the ROflumilast Biopsy European Research Trial (ROBERT) was to assess the anti-inflammatory effects of roflumilast on bronchial mucosal inflammation in patients with moderate-to-severe chronic obstructive pulmonary disease (COPD) and chronic bronchitis. METHODS: ROBERT was a randomised, double-blind, placebo-controlled trial done at 18 sites in five countries. Eligible patients were aged 40-80 years, had COPD, and had had a chronic productive cough for 3 months in each of the two previous years. Patients also had to have a post-bronchodilator predicted FEV1 30-80% and a post-bronchodilator FEV1/forced vital capacity ratio of 70% or less. Patients entered a 6-week run-in period before being randomly assigned (1:1) via a computerised central randomisation system to roflumilast 500 \u3bcg once daily or placebo for 16 weeks, in addition to bronchodilator therapy (inhaled corticosteroids were not permitted). Randomisation was stratified by concomitant use of long-acting \u3b2 agonist. Both participants and investigators were masked to group assignment. Roflumilast and placebo were supplied as identical yellow, triangular tablets. Airway inflammation was assessed by quantification of inflammatory cells in bronchial biopsy samples and induced sputum samples. The primary endpoint was the change in the number of CD8 inflammatory cells in bronchial biopsy submucosa from randomisation to week 16 in the intention-to-treat population. Changes in cell counts of additional inflammatory markers, including eosinophils, were assessed as secondary endpoints. This trial is registered with ClinicalTrials.gov, number NCT01509677, and is closed to new participants, with follow-up completed. FINDINGS: Between Jan 4, 2012, and Feb 11, 2016, 158 patients were randomly assigned: 79 to the roflumilast group, and 79 to the placebo group. At week 16, the change in the number of CD8 cells in the bronchial submucosa did not differ significantly between the roflumilast and placebo groups (treatment ratio 1\ub703 [95% CI 0\ub782-1\ub730]; p=0\ub779). However, compared with placebo, roflumilast was associated with a significant reduction in eosinophils in bronchial biopsy samples at week 16 (treatment ratio 0\ub753 [95% CI 0\ub734-0\ub782]; p=0\ub70046). Significant reductions in both absolute (p=0\ub70042) and differential (p=0\ub70086) eosinophil cell counts in induced sputum were also noted with roflumilast compared with placebo, but peripheral blood eosinophil counts were not significantly affected. We noted no other significant effects of roflumilast on bronchial mucosal inflammatory cells. The most common (ie, occurring in >5% patients) moderate adverse events were worsening of COPD (three [4%] patients in the roflumilast group vs seven [9%] in the placebo group), cough (six [8%] vs four [5%]), diarrhoea (four [5%] vs three [4%]), and nasopharyngitis (three [4%] vs five [6%]). Severe adverse events included worsening of COPD, which occurred in four (5%) patients in the roflumilast group and two (3%) in the placebo group. No deaths occurred during the study. Serious adverse events occurred in eight (10%) patients in the roflumilast group and five (6%) in the placebo group. INTERPRETATION: 16 weeks of treatment with roflumilast did not affect the number of CD8 cells in bronchial submucosa compared with placebo. However, we noted significant reductions in eosinophil cell counts in bronchial biopsy samples and induced sputum, generating the hypothesis that the effect of roflumilast in COPD could be mediated by an effect on lung eosinophils