Davina Camargo Madeira Simoes

Osteopontin has a crucial role in allergic airway disease through regulation of dendritic cell subsets.

Osteopontin (Opn) is important for T helper type 1 (TH1) immunity and autoimmunity. However, the role of this cytokine in TH2-mediated allergic disease as well as its effects on primary versus secondary antigenic encounters remain unclear. Here we demonstrate that OPN is expressed in the lungs of asthmatic individuals and that Opn-s, the secreted form of Opn, exerts opposing effects on mouse TH2 effector responses and subsequent allergic airway disease: pro-inflammatory at primary systemic sensitization, and anti-inflammatory during secondary pulmonary antigenic challenge. These effects of Opn-s are mainly mediated by the regulation of TH2-suppressing plasmacytoid dendritic cells (DCs) during primary sensitization and TH2-promoting conventional DCs during secondary antigenic challenge. Therapeutic administration of recombinant Opn during pulmonary secondary antigenic challenge decreased established TH2 responses and protected mice from allergic disease. These effects on TH2 allergic responses suggest that Opn-s is an important therapeutic target and provide new insight into its role in immunity.

Effect of pulmonary rehabilitation on muscle remodelling in cachectic patients with COPD

It is known that non-cachectic patients with chronic obstructive pulmonary disease (COPD) respond well to pulmonary rehabilitation, but whether cachectic COPD patients are capable of adaptive responses is both important and unknown. 10 cachectic and 19 non-cachectic COPD patients undertook high-intensity cycling training, at the same relative intensity, for 45 min·day−1, 3 days·week−1 for 10 weeks. Before and after rehabilitation vastus lateralis muscle biopsies were analysed morphologically and for the expression of muscle remodelling factors (insulin-like growth factor (IGF)-I, myogenic differentiation factor D (MyoD), tumour necrosis factor (TNF)-α, nuclear factor (NF)-&kgr;B and myostatin) and key components of ubiquitin-mediated proteolytic systems (muscle ring finger protein (MURF)-1 and Atrogin-1). Rehabilitation improved peak work-rate and the 6-min walk distance similarly in non-cachectic (18±3% and 42±13 m, respectively) and cachectic (16±2% and 53±16 m, respectively) patients, but quality of life only improved in non-cachectic COPD. Mean muscle fibre cross-sectional area increased in both groups, but significantly less in cachectic (7±2%) than in non-cachectic (11±2%) patients. Both groups equally decreased the proportion of type IIb fibres and increased muscle capillary/fibre ratio. IGF-I mRNA expression increased in both groups, but IGF-I protein levels increased more in non-cachectic COPD. MyoD was upregulated, whereas myostatin was downregulated at the mRNA and protein level only in non-cachectic patients. Whilst rehabilitation had no effect on TNF-α expression, it decreased the activation of the transcription factor NF-&kgr;B in both groups by the same amount. Atrogin-1 and MURF-1 expression were increased in cachectic COPD, but it was decreased in non-cachectic patients. Cachectic COPD patients partially retain the capacity for peripheral muscle remodelling in response to rehabilitation and are able to increase exercise capacity as much as those without cachexia, even if they exhibit both quantitative and qualitative differences in the type of muscle fibre remodelling in response to exercise training.

Effects of rehabilitative exercise on peripheral muscle TNFα, IL-6, IGF-I and MyoD expression in patients with COPD

Background: Skeletal muscle wasting commonly occurs in patients with chronic obstructive pulmonary disease (COPD) and has been associated with the presence of systemic inflammation. This study investigated whether rehabilitative exercise training decreases the levels of systemic or local muscle inflammation or reverses the abnormalities associated with muscle deconditioning. Methods: Fifteen patients with COPD (mean (SE) forced expiratory volume in 1 s 36 (4)% predicted) undertook high-intensity exercise training 3 days/week for 10 weeks. Before and after the training programme the concentration of tumour necrosis factor &agr; (TNF&agr;), interleukin-6 (IL-6) and C-reactive protein (CRP) in plasma was determined by ELISA, and vastus lateralis mRNA expression of TNF&agr;, IL-6, total insulin-like growth factor-I (IGF-I) and its isoform mechanogrowth factor (MGF) and myogenic differentiation factor D (MyoD) were assessed by real-time PCR. Protein levels of TNF&agr;, IGF-I and MyoD were measured by Western blotting. Results: Rehabilitation improved peak exercise work rate by 10 (2%) (p = 0.004) and mean fibre cross-sectional area from 4061 (254) &mgr;m2 to 4581 (241) &mgr;m2 (p = 0.001). Plasma inflammatory mediators and vastus lateralis expression of TNF&agr; and IL-6 were not significantly modified by training. In contrast, there was a significant increase in mRNA expression of IGF-I (by 67 (22)%; p = 0.044), MGF (by 67 (15)%; p = 0.002) and MyoD (by 116 (30)%; p = 0.001). The increase observed at the mRNA level was also seen at the protein level for IGF-I (by 72 (36)%; p = 0.046) and MyoD (by 67 (21)%; p = 0.012). Conclusions: Pulmonary rehabilitation can induce peripheral muscle adaptations and modifications in factors regulating skeletal muscle hypertrophy and regeneration without decreasing the levels of systemic or local muscle inflammation.

Osteopontin Deficiency Protects against Airway Remodeling and Hyperresponsiveness in Chronic Asthma

RATIONALE Osteopontin (OPN) is a cytokine that is upregulated in epithelial cells and macrophages in the lungs of mice during chronic allergen challenge and airway remodeling and also in lungs of patients with asthma. However, it remains unclear whether OPN has an in vivo effect on lung remodeling in allergic asthma. Based on its ability to induce smooth muscle and fibroblast proliferation and migration we hypothesize that OPN regulates lung remodeling and also affects subsequent airway hyperresponsiveness (AHR). OBJECTIVES Study the role of OPN in airway remodeling using OPN-knockout (KO) mice and a reversal approach administering recombinant mouse OPN (rOPN) in KO mice before challenge. METHODS A chronic allergen-challenge model of airway remodeling with OPN KO mice, KO mice treated with rOPN, and human bronchial smooth muscle were used. MEASUREMENTS AND MAIN RESULTS OPN deficiency protected mice against ova-induced AHR, which was associated with lower collagen and mucus production, gob-5 mRNA expression, submucosal cell area infiltration, and proliferation. Administration of rOPN to KO mice, just at the final five allergen challenges, exacerbated AHR and all the remodeling characteristics measured. In addition, rOPN increased the expression of IL-13 and pro-matrix metalloproteinase-9 in the lungs. Moreover, we demonstrated that rOPN induces proliferation of human BSM through binding to its alpha(v)beta3 integrin receptor and activation of PI3K/Akt downstream signaling pathway. CONCLUSIONS We conclude that OPN deficiency protects against remodeling and AHR. Thus our data reveal OPN as a novel therapeutic target for airway remodeling and associated AHR in chronic asthma.

Angiopoietin-1 Protects against Airway Inflammation and Hyperreactivity in Asthma

RATIONALE The angiopoietins (Ang) comprise a family of growth factors mainly known for their role in blood vessel formation and remodeling. The best-studied member, Ang-1, exhibits antiapoptotic and antiinflammatory effects. Although the involvement of Ang-1 in angiogenesis is well recognized, little information exists about its role in respiratory physiology and disease. On the basis of its ability to inhibit vascular permeability, adhesion molecule expression, and cytokine production, we hypothesized that Ang-1 administration might exert a protective role in asthma. OBJECTIVES To determine changes in the expression of Ang and to assess the ability of Ang-1 to prevent the histologic, biochemical, and functional changes observed in an animal model of asthma. METHODS To test our hypothesis, a model of allergic airway disease that develops after ovalbumin (OVA) sensitization and challenge was used. MEASUREMENTS AND MAIN RESULTS Ang-1 expression was reduced at the mRNA and protein levels in lung tissue of mice sensitized and challenged with OVA, leading to reduced Tie2 phosphorylation. Intranasal Ang-1 treatment prevented the OVA-induced eosinophilic lung infiltration, attenuated the increase in IL-5 and IL-13, and reduced eotaxin and vascular cell adhesion molecule 1 expression. These antiinflammatory actions of Ang-1 coincided with higher levels of IkappaB and decreased nuclear factor-kappaB binding activity. More importantly, Ang-1 reversed the OVA-induced increase in tissue resistance and elastance, improving lung function. CONCLUSIONS We conclude that Ang-1 levels are decreased in asthma and that administration of Ang-1 might be of therapeutic value because it prevents the increased responsiveness of the airways to constrictors and ameliorates inflammation.

Vascular endothelial growth factor: an angiogenic factor reflecting airway inflammation in healthy smokers and in patients with bronchitis type of chronic obstructive pulmonary disease?

BackgroundPatients with bronchitis type of chronic obstructive pulmonary disease (COPD) have raised vascular endothelial growth factor (VEGF) levels in induced sputum. This has been associated with the pathogenesis of COPD through apoptotic and oxidative stress mechanisms. Since, chronic airway inflammation is an important pathological feature of COPD mainly initiated by cigarette smoking, aim of this study was to assess smoking as a potential cause of raised airway VEGF levels in bronchitis type COPD and to test the association between VEGF levels in induced sputum and airway inflammation in these patients.Methods14 current smokers with bronchitis type COPD, 17 asymptomatic current smokers with normal spirometry and 16 non-smokers were included in the study. VEGF, IL-8, and TNF-α levels in induced sputum were measured and the correlations between these markers, as well as between VEGF levels and pulmonary function were assessed.ResultsThe median concentrations of VEGF, IL-8, and TNF-α were significantly higher in induced sputum of COPD patients (1,070 pg/ml, 5.6 ng/ml and 50 pg/ml, respectively) compared to nonsmokers (260 pg/ml, 0.73 ng/ml, and 15.4 pg/ml, respectively, p < 0.05) and asymptomatic smokers (421 pg/ml, 1.27 ng/ml, p < 0.05, and 18.6 pg/ml, p > 0.05, respectively). Significant correlations were found between VEGF levels and pack years (r = 0.56, p = 0.046), IL-8 (r = 0.64, p = 0.026) and TNF-α (r = 0.62, p = 0.031) levels both in asymptomatic and COPD smokers (r = 0.66, p = 0.027, r = 0.67, p = 0.023, and r = 0.82, p = 0.002, respectively). No correlation was found between VEGF levels in sputum and pulmonary function parameters.ConclusionVEGF levels are raised in the airways of both asymptomatic and COPD smokers. The close correlation observed between VEGF levels in the airways and markers of airway inflammation in healthy smokers and in smokers with bronchitis type of COPD is suggestive of VEGF as a marker reflecting the inflammatory process that occurs in smoking subjects without alveolar destruction.

Breath markers of oxidative stress and airway inflammation in Seasonal Allergic Rhinitis.

Oxidative stress (OS) is well documented in asthma, but so far little data has been reported in non-asthmatic patients with Seasonal Allergic Rhinitis (SAR). The aim of this study is to investigate the degree of OS and airway inflammation in patients with SAR, with and without concomitant Asthma (SAR +A), using breath markers in exhaled air and in Exhaled Breath Condensate (EBC). In addition, the effects of natural allergen exposure and intranasal steroid treatment on these markers were evaluated. Exhaled NO (eNO) and CO, combined with measurements of 8-Isoprostane (Iso-8), Leukotriene B4 (LTB4) and nitrate/nitrite in EBC, were performed in 23 patients, 11 with SAR and 12 with SAR+A, and 16 healthy subjects. Iso-8 and LTB4 were significantly increased in both groups of patients (median values 43.6 pg/ml and 138.4 pg/ml in SAR group; 38.9 pg/ml, and 164.6 pg/ml in SAR+A group respectively; p>0.05) compared to healthy subjects (18.6 pg/ml and 7.8 pg/ml; p<0.05). Nitrate/nitrite and eNO levels were elevated in both groups compared to controls, but were significantly higher in the SAR+A compared to SAR group (nitrate/nitrite 9 μM and 3.9 μM; p=0.025; and eNO 18.5 ppb and 12.5 ppb, respectively; p>0.05). Nasal steroids caused significant reduction in LTB4 and 8-isoprostane levels in both groups of patients (p<0.05), while nitrate levels and eNO concentration were little affected by nasal treatment. OS markers were decreased at normal levels out of pollen season. Natural allergen exposure induces OS and airway inflammation, as assessed by measurements of markers in EBC and exhaled air, in patients with SAR who have no clinical signs of lower airway involvement. Besides, intranasal steroid treatment may have a regulatory role in the OS.

Increased levels of osteopontin in sputum supernatant in severe refractory asthma

Background Osteopontin (OPN) is a glycoprotein that has been associated with inflammation and fibrosis. Severe refractory asthma (SRA) is characterised by an intense inflammatory and remodelling process. The aim of this study was to investigate the levels of OPN in sputum supernatants of patients with SRA, to compare them with milder forms of the disease and to investigate their possible association with mediators and cells involved in the inflammatory and remodelling process. Methods 33 patients with SRA, 29 with moderate asthma, 21 with steroid-naïve asthma and 20 healthy subjects were studied. All subjects underwent lung function tests, bronchial hyper-responsiveness assessment and sputum induction for cell count identification and measurement of OPN, vascular endothelial growth factor, transforming growth factor β1 (TGF-β1), cysteinyl leukotrienes, interleukin 13 (IL-13), eosinophilic cationic protein (ECP) and IL-8 in sputum supernatants. Results Median (IQR) OPN levels (pg/ml) were significantly higher in patients with SRA than in those with moderate asthma, steroid-naive asthma and healthy control subjects (1840 (1125–11000) vs 130 (100–210) vs 100 (67–130) vs 50 (42–70), respectively, p<0.001). Regression analysis showed a significant association between log OPN and sputum eosinophils, cysteinyl leukotrienes, IL-13, TGF-β1 and ECP. TGF-β1 represented the strongest association with OPN. The above associations were not observed in milder forms of the disease or in healthy subjects. Conclusions The results indicate that OPN levels are higher in SRA than in less severe forms of the disease. Moreover, OPN is associated with mediators involved in both the inflammatory and remodelling process such as TGF-β1, IL-13 and cysteinyl leukotrienes only in SRA.

Glucocorticoid and estrogen receptors are reduced in mitochondria of lung epithelial cells in asthma.

Mitochondrial glucocorticoid (mtGR) and estrogen (mtER) receptors participate in the coordination of the cell’s energy requirement and in the mitochondrial oxidative phosphorylation enzyme (OXPHOS) biosynthesis, affecting reactive oxygen species (ROS) generation and induction of apoptosis. Although activation of mtGR and mtER is known to trigger anti-inflammatory signals, little information exists on the presence of these receptors in lung tissue and their role in respiratory physiology and disease. Using a mouse model of allergic airway inflammation disease and applying confocal microscopy, subcellular fractionation, and Western blot analysis we showed mitochondrial localization of GRα and ERβ in lung tissue. Allergic airway inflammation caused reduction in mtGRα, mtERβ, and OXPHOS enzyme biosynthesis in lung cells mitochondria and particularly in bronchial epithelial cells mitochondria, which was accompanied by decrease in lung mitochondrial mass and induction of apoptosis. Confirmation and validation of the reduction of the mitochondrial receptors in lung epithelial cells in human asthma was achieved by analyzing autopsies from fatal asthma cases. The presence of the mitochondrial GRα and ERβ in lung tissue cells and especially their reduction in bronchial epithelial cells during allergic airway inflammation suggests a crucial role of these receptors in the regulation of mitochondrial function in asthma, implicating their involvement in the pathophysiology of the disease.

Increased levels of angiopoietins 1 and 2 in sputum supernatant in severe refractory asthma

Airway and vascular remodeling may play a prominent role in the clinical severity of severe refractory asthma (SRA). Angiopoietin‐1 (Ang‐1) is an essential mediator of angiogenesis by establishing vascular integrity, whereas angiopoietin‐2 (Ang‐2) acts as its natural inhibitor.