Simonetta Baraldo

Increased activation of p38 MAPK in COPD

Inflammation, oxidative stress and apoptosis, which are involved in chronic obstructive pulmonary disease (COPD) pathogenesis, may activate the p38 subgroup of mitogen-activated protein kinases (MAPKs). Therefore, the aim of the present study was to evaluate the expression of the phosphorylated, active form of p38 MAPK (phospho-p38) in the lungs of COPD patients. Surgical specimens were obtained from 18 smokers with COPD at different stages of disease severity, plus nine smoking and eight nonsmoking subjects with normal lung function. Phospho-p38+ cells were quantified by immunohistochemistry in both alveolar spaces and alveolar walls. Moreover, a Western blot analysis of phospho-p38 and total p38α isoform expressed by alveolar macrophages was performed. Phospho-p38+ alveolar macrophages and phospho-p38+ cells in alveolar walls were increased in patients with severe and mild/moderate COPD, compared with smoking and nonsmoking controls. Moreover, they were inversely correlated to values of forced expiratory volume in one second (FEV1) and FEV1/forced vital capacity. Western blot analysis showed that phosphorylated p38, but not the total p38α isoform, was specifically increased in alveolar macrophages from COPD patients. Activation of the p38 mitogen-activated protein kinase pathway appears to be involved in the pathogenesis of chronic obstructive pulmonary disease. The present findings suggest that this protein may be a suitable pharmacological target for therapeutic intervention.

Vascular endothelial growth factor up‐regulation and bronchial wall remodelling in asthma

Background There is increasing in vitro evidence to support a role for vascular endothelial growth factor (VEGF), a major regulator of angiogenesis, as a mediator of fibrosis associated with neovascularization.

IL-32, a novel proinflammatory cytokine in chronic obstructive pulmonary disease.

RATIONALE Chronic obstructive pulmonary disease (COPD) is a chronic inflammatory disorder of the lung, yet the mechanisms that regulate this immune-inflammatory response are not fully understood. OBJECTIVES We investigated whether IL-32, a newly discovered cytokine, was related to markers of inflammation and clinical progression in COPD. METHODS Using immunohistochemistry, expression of IL-32 was examined in surgically resected specimens from 40 smokers with COPD (FEV(1) = 39 +/- 4% predicted), 11 smokers with normal lung function, and 9 nonsmoking control subjects. IL-32 was quantified in alveolar macrophages, alveolar walls, bronchioles, and arterioles, and confirmed by molecular analysis. The levels of IL-32 were correlated with the cellular infiltrates, markers of inflammation, and clinical data. MEASUREMENTS AND MAIN RESULTS Macrophage staining for IL-32 was increased in smokers with COPD compared with control smokers and nonsmokers (P = 0.0014 and P < 0.0001, respectively), and similar differences were observed in alveolar walls (P = 0.0004 and P = 0.0005) and bronchiolar epithelium (P = 0.004 and P = 0.0009). This increase was also detected at the mRNA level (P = 0.007 vs. control smokers and P = 0.029 vs. nonsmokers) and was mainly due to non-alpha isoforms. Moreover, IL-32 expression was positively correlated with tumor necrosis factor-alpha (P = 0.004, r(s)=0.70), CD8(+)cells (P = 0.02, r(s)=0.46), phospho p38MAPK (P < 0.01, r(s)=0.60) and negatively with FEV(1) values (P = 0.004, r(s)= -0.53). CONCLUSIONS This is the first study to demonstrate increased expression of IL-32 in lung tissue of patients with COPD, where it was colocalized with tumor necrosis factor-alpha and correlated with the degree of airflow obstruction. These results suggest that IL-32 is implicated in the characteristic immune response of COPD, with a possible impact on disease progression.

Neutrophilic infiltration within the airway smooth muscle in patients with COPD

Background: COPD is an inflammatory disorder characterised by chronic airflow limitation, but the extent to which airway inflammation is related to functional abnormalities is still uncertain. The interaction between inflammatory cells and airway smooth muscle may have a crucial role. Methods: To investigate the microlocalisation of inflammatory cells within the airway smooth muscle in COPD, surgical specimens obtained from 26 subjects undergoing thoracotomy (eight smokers with COPD, 10 smokers with normal lung function, and eight non-smoking controls) were examined. Immunohistochemical analysis was used to quantify the number of neutrophils, macrophages, mast cells, CD4+ and CD8+ cells localised within the smooth muscle of peripheral airways. Results: Smokers with COPD had an increased number of neutrophils and CD8+ cells in the airway smooth muscle compared with non-smokers. Smokers with normal lung function also had a neutrophilic infiltration in the airway smooth muscle, but to a lesser extent. When all the subjects were analysed as one group, neutrophilic infiltration was inversely related to forced expiratory volume in 1 second (% predicted). Conclusions: Microlocalisation of neutrophils and CD8+ cells in the airway smooth muscle in smokers with COPD suggests a possible role for these cells in the pathogenesis of smoking induced airflow limitation.

Nonatopic Children with Multitrigger Wheezing Have Airway Pathology Comparable to Atopic Asthma

RATIONALE Epidemiologic studies have shown that, in atopic children, wheezing is more likely to persist into adulthood, eventually becoming asthma, whereas it appears to resolve by adolescence in nonatopic children. OBJECTIVES To investigate whether among children with multitrigger wheeze responsive to bronchodilators the airway pathology would be different in nonatopic wheezers, who are often considered nonasthmatic, compared with atopic wheezers, who are more frequently diagnosed as having asthma. METHODS Bronchial biopsies were obtained from 55 children undergoing bronchoscopy for appropriate clinical indications: 18 nonatopic children with multitrigger wheeze (median age, 5 yr; range, 2-10 yr), 20 atopic children with multitrigger wheeze (medan age, 5 yr; range, 2-15 yr), and 17 control children with no atopy or wheeze (median age, 4; range, 2-14 yr). By histochemistry and immunohistochemistry, we quantified epithelial loss, basement membrane thickness, angiogenesis, inflammatory cells, IL-4(+,) and IL-5(+) cells in subepithelium. MEASUREMENTS AND MAIN RESULTS Unexpectedly, all pathologic features examined were similar in atopic and nonatopic wheezing children. Compared with control subjects, both nonatopic and atopic wheezing children had increased epithelial loss (P = 0.03 and P = 0.002, respectively), thickened basement membrane (both P < 0.0001), and increased number of vessels (P = 0.003 and P = 0.03, respectively) and eosinophils (P < 0.0001 and P = 0.002, respectively). Moreover, they had increased cytokine expression, which was highly significant for IL-4 (P = 0.002 and P = 0.0001, respectively) and marginal for IL-5 (P = 0.02 and P = 0.08, respectively). CONCLUSIONS This study shows that the airway pathology typical of asthma is present in nonatopic wheezing children just as in atopic wheezing children. These results suggest that, when multitrigger wheezing responsive to bronchodilators is present, it is associated with pathologic features of asthma even in nonatopic children.

Marked alveolar apoptosis/proliferation imbalance in end-stage emphysema.

BackgroundApoptosis has recently been proposed to contribute to the pathogenesis of emphysema.MethodsIn order to establish if cell fate plays a role even in end-stage disease we studied 16 lungs (9 smoking-associated and 7 α1antitrypsin (AAT)-deficiency emphysema) from patients who had undergone lung transplantations. Six unused donor lungs served as controls. Apoptosis was evaluated by TUNEL analysis, single-stranded DNA laddering, electron microscopy and cell proliferation by an immunohistochemical method (MIB1). The role of the transforming growth factor (TGF)-β1 pathway was also investigated and correlated with epithelial cell turnover and with the severity of inflammatory cell infiltrate.ResultsThe apoptotic index (AI) was significantly higher in emphysematous lungs compared to the control group (p ≤ 0.01), particularly if only lungs with AAT-deficiency emphysema were considered (p ≤ 0.01 vs p = 0.09). The proliferation index was similar in patients and controls (1.9 ± 2.2 vs 1.7 ± 1.1). An increased number of T lymphocytes was observed in AAT-deficiency lungs than smoking-related cases (p ≤ 0.05). TGF-β1 expression in the alveolar wall was higher in patients with smoking-associated emphysema than in cases with AAT-deficiency emphysema (p ≤ 0.05). A positive correlation between TGF-βRII and AI was observed only in the control group (p ≤ 0.005, r2 = 0.8). A negative correlation was found between the TGF-β pathway (particularly TGF-βRII) and T lymphocytes infiltrate in smoking-related cases (p ≤ 0.05, r2 = 0.99)ConclusionOur findings suggest that apoptosis of alveolar epithelial cells plays an important role even in end-stage emphysema particularly in AAT-deficiency disease. The TGFβ-1 pathway does not seem to directly influence epithelial turnover in end-stage disease. Inflammatory cytokine different from TGF-β1 may differently orchestrate cell fate in AAT and smoking-related emphysema types.

Fixed airflow obstruction due to asthma or chronic obstructive pulmonary disease: 5-year follow-up

BACKGROUND Both smokers and patients with asthma can experience fixed airflow obstruction, which is associated with distinctive patterns of airway pathology. The influence of fixed airflow obstruction on the prognosis of these patients is unknown. OBJECTIVE We sought to investigate lung function decline and exacerbations in a 5-year prospective study of subjects with fixed airflow obstruction due to asthma or chronic obstructive pulmonary disease (COPD). We also sought to explore correlations between functional, pathological, and clinical features. METHODS Patients with fixed airflow obstruction due to asthma (n = 16) or COPD (n = 21) and a control group of asthmatic patients with fully reversible airflow obstruction (n = 15) were followed for 5 years. RESULTS The rates of decline in FEV(1) were similar in patients with fixed airflow obstruction caused by asthma (-49.7 +/- 10.6 mL/y) or COPD (-51.4 +/- 9.8 mL/y) and were higher than in asthmatic patients with reversible airflow obstruction (-18.1 +/- 10.1 mL/y, P < .01). Exacerbation rates were also higher in patients with fixed airflow obstruction caused by asthma (1.41 +/- 0.26 per patient-year) or COPD (1.98 +/- 0.3 per patient-year) compared with those seen in asthmatic patients with reversible airflow obstruction (0.53 +/- 0.11 per patient-year, P < .01). Baseline exhaled nitric oxide levels and sputum eosinophil counts correlated with the FEV(1) decline in asthmatic patients with fixed airflow obstruction. By contrast, baseline sputum neutrophil counts, emphysema scores, comorbidities, and exacerbation frequency correlated directly and pulmonary diffusion capacity correlated inversely with the FEV(1) decline in patients with COPD. CONCLUSION In both patients with asthma and those with COPD, fixed airflow obstruction is associated with increased lung function decline and frequency of exacerbations. Nevertheless, the decline in lung function entails the specific pathological and clinical features of the underlying diseases.

MUC5AC expression is increased in bronchial submucosal glands of stable COPD patients.

Aims:  Mucus expectoration is a common feature of chronic obstructive pulmonary disease (COPD). MUC5AC and MUC5B, the major mucins, are released predominantly from submucosal glands in the central airways. The aim was to investigate gland size and MUC5AC and MUC5B expression in bronchial rings from smokers with COPD compared with control groups.

Pathophysiology of the Small Airways in Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is characterized by a persistent airflow limitation that is usually progressive and associated with an enhanced chronic inflammatory response in the airways and the lung to noxious particles or gases. From a pathological point of view, COPD is characterized by two distinct and frequently coexisting aspects: small airway abnormalities and parenchymal destruction (or emphysema). When pathological changes are localized in lung parenchyma, they will contribute to airflow limitation by reducing the elastic recoil of the lung through parenchymal destruction, as well as by reducing the elastic load applied to the airways through destruction of alveolar attachments. Conversely, when pathological changes involve the small airways, they will contribute to airflow limitation by narrowing and obliterating the lumen and by actively constricting the airways, therefore increasing the resistance. In this article we will review the structural abnormalities in small airways and their relationship with the disordered pulmonary function in COPD, in the attempt to disentangle the mechanisms contributing to the development and progression of airflow limitation in smokers. We will start by describing the normal structure of the small airways, and then observe the main pathological alterations that accumulate in this site and how they parallel pulmonary function derangement.

A novel insight into adaptive immunity in chronic obstructive pulmonary disease: B cell activating factor belonging to the tumor necrosis factor family.

RATIONALE Chronic obstructive pulmonary disease (COPD) is a disorder characterized by an abnormal inflammatory response that persists even after smoking cessation, yet the underlying mechanisms are not fully understood. OBJECTIVES To investigate the expression of B-cell activating factor of tumor necrosis factor family (BAFF), a crucial mediator in the crosstalk between innate and adaptive immune responses, in patients with COPD and to explore its correlation with disease severity. METHODS Using immunohistochemistry, expression of BAFF was examined in lung specimens from 21 smokers with COPD (FEV(1) = 57 ± 5% predicted), 14 control smokers (FEV(1) = 99 ± 2% predicted) and 8 nonsmokers (FEV(1) = 104 ± 4% predicted). BAFF was quantified in alveolar macrophages and alveolar walls, in bronchiolar and parenchymal lymphoid follicles, and in peripheral airways and pulmonary arterioles. MEASUREMENTS AND MAIN RESULTS In alveolar macrophages and parenchymal lymphoid follicles, BAFF expression was increased in smokers with COPD compared with control smokers and nonsmokers (P < 0.05 for all comparisons). In both compartments, BAFF was also up-regulated in control smokers as compared with nonsmokers (P = 0.03 and P = 0.01). Moreover, BAFF was overexpressed in bronchiolar lymphoid follicles, alveolar walls, peripheral airways, and pulmonary arterioles from smokers with COPD compared with nonsmokers (P < 0.05 for all). Among patients with COPD, BAFF(+) macrophages were inversely related to FEV(1) (P = 0.03, Spearmans rho [r(S)] = -0.48), FEV(1)/FVC (P = 0.02, r(S) = -0.50), and Pa(O(2)) values (P = 0.01, r(S) = -0.55). CONCLUSIONS This study demonstrated overexpression of BAFF in peripheral lung of patients with COPD, mainly in alveolar macrophages and lymphoid follicles. Moreover, BAFF expression was correlated to the degree of lung function impairment and hypoxia, suggesting that it may have a possible impact on disease severity.