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.     

VEGF and IL-18 in induced sputum of lung cancer patients

Cytokines are key players in the biological processes of malignant tumors and special interest has been focused on cytokines exerting tumor and anti-tumor properties, such as vascular endothelial growth factor (VEGF) and Interleukin-18 (IL-18). Aim of this study was to assess IL-18 and VEGF levels in induced sputum of lung cancer patients at diagnosis, and assess their possible association with the histological type of cancer, the stage and the overall patient survival. Seventy six patients with a diagnosis of lung cancer were recruited and were followed up for 48months. Thirteen healthy smokers and 16 healthy non-smokers were used as control groups. VEGF and IL-18 were measured by ELISA in sputum supernatants at the time of diagnosis. Lung cancer patients had significantly higher baseline IL-18 and VEGF levels compared to healthy controls (p<0.001). No difference was found in IL-18 and VEGF levels between the various stages in non-small cell lung cancer (NSCLC) and between limited and extended small cell lung cancer (SCLC). However, the ratio of VEGF/IL-18 was significantly higher in NSCLC compared to SCLC patients (p=0.018). In extended SCLC overall survival was inversely associated with baseline sputum VEGF levels (p=0.034) and estimated mortality risk was 1.14 (95% CI 1.006-1.283) for an increase of 100pg/ml in VEGF levels. Such association was not found regarding baseline IL-18 levels. VEGF levels in induced sputum may have a prognostic role in the survival of SCLC. The ratio VEGF/IL-18 in induced sputum differs between NSCLC and SCLC, indicating differences in angiogenesis mechanisms and/or immunological response in these two major histological types of lung cancer.     

Compartment differences of inflammatory activity in chronic obstructive pulmonary disease

Background

Chronic obstructive pulmonary disease (COPD) is associated with local and systemic inflammation. The knowledge of interaction and co-variation of the inflammatory responses in different compartments is meagre.

Method

Healthy controls (n = 23), smokers with (n = 28) and without (n = 29) COPD performed spirometry and dental examinations. Saliva, induced sputum, bronchoalveolar lavage (BAL) fluid and serum were collected. Inflammatory markers were assessed in all compartments using ELISA, flow cytometry and RT-PCR.

Results

Negative correlations between lung function and saliva IL-8 and matrix metalloproteinase-9 (MMP-9) were found in smokers with COPD. IL-8 and MMP-9 in saliva correlated positively with periodontal disease as assessed by gingival bleeding in non-smokers.Tumor necrosis factor-α (TNF-α) in saliva, serum and TNF-α mRNA expression on macrophages in BAL-fluid were lower in smokers than in non-smokers. There were positive correlations between soluble TNF-α receptor 1 (sTNFR1) and soluble TNF-α receptor 2 (sTNFR2) in sputum, BAL-fluid and serum in all groups. Sputum interleukin-8 (IL-8) or interleukin-6 (IL-6) was positively correlated with sTNFR1 or sTNFR2 in non-smokers and with sTNFR2 in COPD.

Conclusion

Saliva which is convenient to collect and analyse, may be suitable for biomarker assessment of disease activity in COPD. An attenuated TNF-α expression was demonstrated by both protein and mRNA analyses in different compartments suggesting that TNF-α response is altered in moderate and severe COPD. Shedding of TNFR1 or TNFR2 is similarly regulated irrespective of airflow limitation.     

Vascular endothelial growth factor as a non-invasive marker of pulmonary vascular remodeling in patients with bronchitis-type of COPD

BackgroundSeveral studies have indicated that one of the most potent mediators involved in pulmonary vascular remodeling is vascular endothelial growth factor (VEGF). This study was designed to determine whether airway VEGF level reflects pulmonary vascular remodeling in patients with bronchitis-type of COPD.MethodsVEGF levels in induced sputum were examined in 23 control subjects (12 non-smokers and 11 ex-smokers) and 29 patients with bronchitis-type of COPD. All bronchitis-type patients performed exercise testing with right heart catheterization.ResultsThe mean pulmonary arterial pressure (mPAP) and pulmonary vascular resistance (PVR) after exercise were markedly increased in all bronchitis-type patients. However, both parameters after exercise with breathing of oxygen was significantly lower than in those with breathing of room air. To attenuate the effect of hypoxia-induced pulmonary vasoconstriction during exercise, we used the change in mPAP or PVR during exercise with breathing of oxygen as a parameter of pulmonary vascular remodeling. Change in mPAP was significantly correlated with VEGF level in induced sputum from patients with chronic bronchitis (r = 0.73, p = 0.0001). Moreover, change in PVR was also correlated with VEGF level in those patients (r = 0.57, p = 0.003).ConclusionA close correlation between magnitude of pulmonary hypertension with exercise and VEGF level in bronchitis-type patients could be observed. Therefore, these findings suggest the possibility that VEGF level in induced sputum is a non-invasive marker of pulmonary vascular remodeling in patients with bronchitis-type of COPD.     

Enhanced expression of human β-defensin 2 in peripheral lungs of patients with chronic obstructive pulmonary disease

Human β-defensin 2 (hBD-2) has antimicrobial activity and may play a role in airway mucosal defense, but studies have not yet examined its expression in lung tissue of patients with chronic obstructive pulmonary disease (COPD). Here we investigated hBD-2 levels in lung tissues of COPD patients and analyzed their correlations with IL-8, IL-1β, cigarette smoking and lung function in order to see whether the protein may be involved in pathogenesis of the disease. Peripheral lung tissue specimens were obtained from 51 patients who underwent lung resection for peripheral lung cancer: healthy non-smokers (n = 8), healthy current smokers (n = 7), non-smokers with COPD (n = 11), and current smokers with COPD (n = 25). RT-PCR and immunohistochemical staining were used to detect expression levels of hBD-2, IL-8 and IL-1β. Expression of hBD-2 mRNA was significantly higher in COPD patients than in healthy controls, and significantly higher in current smokers than in non-smokers (p < 0.05). Among healthy controls, hBD-2 mRNA levels were similar between current smokers and non-smokers. Immunohistochemistry showed hBD-2 protein to be expressed mainly in epithelia of distal bronchioles and its expression pattern among our patient groups mirrored that of the mRNA. IL-8 mRNA levels were significantly higher in COPD patients than in healthy controls (p < 0.05), while IL-1β mRNA levels did not differ significantly among the groups. Levels of hBD-2 mRNA positively correlated with levels of IL-8 mRNA (r = 0.545, p = 0.002), and negatively correlated with FEV1/FVC ratios and with predicted FEV1% values (r = −0.406, p = 0.011). Our results indicate that hBD-2 expression is elevated in distal airways of COPD patients and that it may be involved in pathogenesis of the disease. Our data implicate cigarette smoking as a factor that may elevate hBD-2 levels in lung tissues of COPD patients.     

COPD diagnosis related to different guidelines and spirometry techniques

Background

Several studies have indicated that one of the most potent mediators involved in pulmonary vascular remodeling is vascular endothelial growth factor (VEGF). This study was designed to determine whether airway VEGF level reflects pulmonary vascular remodeling in patients with bronchitis-type of COPD.

Methods

VEGF levels in induced sputum were examined in 23 control subjects (12 non-smokers and 11 ex-smokers) and 29 patients with bronchitis-type of COPD. All bronchitis-type patients performed exercise testing with right heart catheterization.

Results

The mean pulmonary arterial pressure (mPAP) and pulmonary vascular resistance (PVR) after exercise were markedly increased in all bronchitis-type patients. However, both parameters after exercise with breathing of oxygen was significantly lower than in those with breathing of room air. To attenuate the effect of hypoxia-induced pulmonary vasoconstriction during exercise, we used the change in mPAP or PVR during exercise with breathing of oxygen as a parameter of pulmonary vascular remodeling. Change in mPAP was significantly correlated with VEGF level in induced sputum from patients with chronic bronchitis (r = 0.73, p = 0.0001). Moreover, change in PVR was also correlated with VEGF level in those patients (r = 0.57, p = 0.003).

Conclusion

A close correlation between magnitude of pulmonary hypertension with exercise and VEGF level in bronchitis-type patients could be observed. Therefore, these findings suggest the possibility that VEGF level in induced sputum is a non-invasive marker of pulmonary vascular remodeling in patients with bronchitis-type of COPD.     

Glutathione S-transferase omega in the lung and sputum supernatants of COPD patients

Background

The major contribution to oxidant related lung damage in COPD is from the oxidant/antioxidant imbalance and possibly impaired antioxidant defence. Glutathione (GSH) is one of the most important antioxidants in human lung and lung secretions, but the mechanisms participating in its homeostasis are partly unclear. Glutathione-S-transferase omega (GSTO) is a recently characterized cysteine containing enzyme with the capability to bind and release GSH in vitro. GSTO has not been investigated in human lung or lung diseases.

Methods

GSTO1-1 was investigated by immunohistochemistry and Western blot analysis in 72 lung tissue specimens and 40 sputum specimens from non-smokers, smokers and COPD, in bronchoalveolar lavage fluid and in plasma from healthy non-smokers and smokers. It was also examined in human monocytes and bronchial epithelial cells and their culture mediums in vitro.

Results

GSTO1-1 was mainly expressed in alveolar macrophages, but it was also found in airway and alveolar epithelium and in extracellular fluids including sputum supernatants, bronchoalveolar lavage fluid, plasma and cell culture mediums. The levels of GSTO1-1 were significantly lower in the sputum supernatants (p = 0.023) and lung homogenates (p = 0.003) of COPD patients than in non-smokers.

Conclusion

GSTO1-1 is abundant in the alveolar macrophages, but it is also present in extracellular fluids and in airway secretions, the levels being decreased in COPD. The clinical significance of GSTO1-1 and its role in regulating GSH homeostasis in airway secretions, however, needs further investigations.     

Increased levels of osteopontin in sputum supernatant of smoking asthmatics

Smoking may modify the inflammatory pattern of the asthmatic airways. Osteopontin (OPN) has been associated with inflammation and fibrosis. In asthma, sputum levels of OPN are elevated and have been related to the underlying severity and to mediators expressing remodeling and inflammation.To evaluate the levels of OPN in sputum supernatants of asthmatic patients and to investigate the possible role of smoking as well as associations with mediators and cells involved in the inflammatory and remodeling process.We studied 103 asthma patients (49 smokers) and 40 healthy subjects (20 smokers) who underwent lung function tests, bronchial hyperresponsiveness to methacholine, and sputum induction for cell count identification and measurement of OPN, TGF-β1, IL-8, IL-13 and ECP in sputum supernatants. The concentrations of all mediators were measured using enzyme immunoassays.OPN levels (pg/ml) were significantly higher in smoking asthmatics compared to non-smoking asthmatics, and both non-smoking and smoking controls [median (interquartile ranges) 1120 (651, 1817) vs. 197 (118, 341) vs. 50 (42, 70) vs. 102 (77, 110) pg/ml, respectively; p < 0.001]. Regression analysis provided significant associations between OPN and sputum neutrophils, IL-8 and TGF-β1, the most significant being the one with TGF-β1. These associations were present only in smoking asthmatics.Smoking habit significantly affects sputum OPN levels in asthma. The associations of OPN with sputum neutrophils, TGF-β1 and IL-8 in smoking asthmatics suggest a possible role for OPN in the neutrophilic inflammation and remodeling process in this phenotype of asthma.     

Long-term (5 year) safety of bronchial thermoplasty: Asthma Intervention Research (AIR) trial

Background

KL-6 is a high-molecular-weight glycoprotein classified as a human MUC1 mucin. It was hypothesized that KL-6 could be detectable in the circulating blood and especially in airway secretions in lung diseases associated with mucus production such as chronic obstructive pulmonary disease (COPD). Additional aims of this study were to investigate whether the levels of KL-6 in plasma and sputum are related to ageing and smoking history.

Methods

The concentrations of KL-6 in plasma and induced sputum supernatants from young and/or middle aged/elderly non-smokers, smokers and patients with COPD were assayed by ELISA (n = 201). The subjects were classified into five groups according to age, smoking status and presence of COPD. In addition, KL-6 expression in control and diseased lung i.e. samples from patients with COPD (n = 28), were analyzed by immunohistochemistry and digital image analysis.

Results

The plasma levels of KL-6 increased with age both in non-smokers and smokers. Among middle aged/elderly subjects, plasma KL-6 levels in all smokers regardless of COPD were significantly higher than in non-smokers, whereas sputum levels of KL-6 were significantly higher in COPD compared not only to non-smokers but also to smokers. KL-6 was more prominently expressed in the bronchiolar/alveolar epithelium in COPD than in the control lungs. Plasma and sputum KL-6 levels correlated inversely with obstruction and positively with smoking history and ageing. The linear multiple regression analysis confirmed that age and cigarette smoking had independent effects on plasma KL-6.

Conclusions

KL-6 increases with ageing and chronic smoking history, but prospective studies will be needed to elucidate the significance of KL-6 in chronic airway diseases.     

Impaired TNFα-induced VEGF Expression in Human Airway Smooth Muscle Cells from Smokers with COPD: Role of MAPkinases and Histone Acetylation—Effect of Dexamethasone

The cytokine and potent angiogenic factor vascular endothelial growth factor (VEGF) plays an important role in airway remodelling in various airway diseases such as idiopathic pulmonary fibrosis, pulmonary hypertension, lung cancer, asthma and chronic obstructive pulmonary disease (COPD). The effect of cigarette-smoking on VEGF expression, the modulatory role of extracellular signal-regulated kinase (ERK)-1,-2, p38mitogen-activated protein kinase (MAPK), histone acetylation and the anti-inflammatory effect of dexamethasone on TNFα-induced VEGF expression were examined in human airway smooth muscle cells (HASMC) of five non-smokers, 17 smokers without airflow limitation and 15 smokers with COPD. TNFα increased VEGF expression 5.4-fold and 4.0-fold in HASMC from non-smokers and smokers without airflow limitation, respectively, but only 2.5-fold in HASMC from smokers with COPD compared with non-stimulated HASMC. VEGF production was dependent on phosphorylation of ERK-1,-2 and p38^MAPK, as was shown by examining the effects of PD 098059 (10 μM), an inhibitor of the upstream activator of MAPKkinase (MKK)-1, and SB 203580 (10 μM), an inhibitor of p38^MAPK; there were no differences between non-smokers, smokers without airflow limitation and smokers with COPD in this respect. Dexamethasone (DEX; 10⁻¹²–10⁻⁴ M) reduced TNFα-induced phosphorylation of ERK-1/-2 and prevented TNFα-induced VEGF generation without differences between non-smokers, smokers with and without COPD. There was an additional inhibitory effect of DEX (10⁻¹² M) on VEGF-release when PD 098059 was added. The basal and TNFα-induced acetylation status of the VEGF-promoter (chromatin immunoprecipitation [ChIP] assay) was increased in HASMC from smokers with COPD compared with smokers without airflow limitation and non-smokers. In comparison to non-stimulated HASMC, TNFα decreased the acetylation status of the VEGF-promoter by ∼46% and ∼43% in HASMC from non-smokers and smokers without COPD compared with ∼68% in HASMC from smokers with COPD. The data suggest that HASMC express VEGF in response to TNFα and that this may be reduced in HASMC of smokers with COPD in a smoking-independent manner. VEGF expression is directly modulated by phosphorylation of ERK-1,-2 and p38^MAPK and by histone acetylation and the acetylation status of the VEGF gene is increased in HASMC of smokers with COPD in a smoking-independent manner. TNFα reduced the acetylation status of the VEGF promoter in HASMC.     

Differential Activation of Killer Cells in the Circulation and the Lung: A Study of Current Smoking Status and Chronic Obstructive Pulmonary Disease (COPD)

Background

CD8⁺ T-lymphocytes, natural killer T-like cells (NKT-like cells, CD56⁺CD3⁺) and natural killer cells (NK cells, CD56⁺CD3⁻) are the three main classes of human killer cells and they are implicated in the pathogenesis of chronic obstructive pulmonary disease (COPD). Activation of these cells can initiate immune responses by virtue of their production of inflammatory cytokines and chemokines that cause lung tissue damage, mucus hypersecretion and emphysema. The objective of the current study was to investigate the activation levels of human killer cells in healthy non-smokers, healthy smokers, ex-smokers with COPD and current smokers with COPD, in both peripheral blood and induced sputum.

Methods/Principal Findings

After informed consent, 124 participants were recruited into the study and peripheral blood or induced sputum was taken. The activation states and receptor expression of killer cells were measured by flow cytometry. In peripheral blood, current smokers, regardless of disease state, have the highest proportion of activated CD8⁺ T-lymphocytes, NKT-like cells and NK cells compared with ex-smokers with COPD and healthy non-smokers. Furthermore, CD8⁺ T-lymphocyte and NK cell activation is positively correlated with the number of cigarettes currently smoked. Conversely, in induced sputum, the proportion of activated killer cells was related to disease state rather than current smoking status, with current and ex-smokers with COPD having significantly higher rates of activation than healthy smokers and healthy non-smokers.

Conclusions

A differential effect in systemic and lung activation of killer cells in COPD is evident. Systemic activation appears to be related to current smoking whereas lung activation is related to the presence or absence of COPD, irrespective of current smoking status. These findings suggest that modulating killer cell activation may be a new target for the treatment of COPD.     

Role of aberrant metalloproteinase activity in the pro-inflammatory phenotype of bronchial epithelium in COPD

Background

Cigarette smoke, the major risk factor for COPD, is known to activate matrix metalloproteinases in airway epithelium. We investigated whether metalloproteinases, particularly A Disintegrin and Metalloproteinase (ADAM)17, contribute to increased pro-inflammatory epithelial responses with respect to the release of IL-8 and TGF-α, cytokines implicated in COPD pathogenesis.

Methods

We studied the effects of cigarette smoke extract (CSE) and metalloproteinase inhibitors on TGF-α and IL-8 release in primary bronchial epithelial cells (PBECs) from COPD patients, healthy smokers and non-smokers.

Results

We observed that TGF-α was mainly shed by ADAM17 in PBECs from all groups. Interestingly, IL-8 production occurred independently from ADAM17 and TGF-α shedding, but was significantly inhibited by broad-spectrum metalloproteinase inhibitor TAPI-2. CSE did not induce ADAM17-dependent TGF-α shedding, while it slightly augmented the production of IL-8. This was accompanied by reduced endogenous inhibitor of metalloproteinase (TIMP)-3 levels, suggesting that CSE does not directly but rather indirectly alter activity of ADAM17 through the regulation of its endogenous inhibitor. Furthermore, whereas baseline TGF-α shedding was lower in COPD PBECs, the early release of IL-8 (likely due to its shedding) was higher in PBECs from COPD than healthy smokers. Importantly, this was accompanied by lower TIMP-2 levels in COPD PBECs, while baseline TIMP-3 levels were similar between groups.

Conclusions

Our data indicate that IL-8 secretion is regulated independently from ADAM17 activity and TGF-α shedding and that particularly its early release is differentially regulated in PBECs from COPD and healthy smokers. Since TIMP-2-sensitive metalloproteinases could potentially contribute to IL-8 release, these may be interesting targets to further investigate novel therapeutic strategies in COPD.     

Gender differences in plasma biomarker levels in a cohort of COPD patients: a pilot study

Rationale

Little is known about gender differences in plasma biomarker levels in patients with chronic obstructive pulmonary disease (COPD).

Hypothesis

There are differences in serum biomarker levels between women and men with COPD.

Objective

Explore gender differences in plasma biomarker levels in patients with COPD and smokers without COPD.

Methods

We measured plasma levels of IL-6, IL-8, IL-16, MCP-1, MMP-9, PARC and VEGF in 80 smokers without COPD (40 males, 40 females) and 152 stable COPD patients (76 males, 76 females) with similar airflow obstruction. We determined anthropometrics, smoking history, lung function, exercise tolerance, body composition, BODE index, co-morbidities and quality of life. We then explored associations between plasma biomarkers levels and the clinical characteristics of the patients and also with the clinical and physiological variables known to predict outcome in COPD.

Results

The plasma biomarkers level explored were similar in men and women without COPD. In contrast, in patients with COPD the median value in pg/mL of IL-6 (6.26 vs 8.0, p = 0.03), IL-16 (390 vs 321, p = 0.009) and VEGF (50 vs 87, p = 0.02) differed between women and men. Adjusted for smoking history, gender was independently associated with IL-16, PARC and VEGF levels. There were also gender differences in the associations between IL-6, IL-16 and VEGF and physiologic variables that predict outcomes.

Conclusions

In stable COPD patients with similar airflow obstruction, there are gender differences in plasma biomarker levels and in the association between biomarker levels and important clinical or physiological variables. Further studies should confirm our findings.     

Immunomodulatory role of vascular endothelial growth factor and angiopoietin-1 in airway remodeling

The blood vessels formed in asthmatic airways are involved in inflammatory and airway remodeling processes in chronic asthma. Vascular endothelial cell growth factor (VEGF) and angiopoietin-1 (Ang-1) are primary angiogenic growth factors, involved in the formation of such blood vessels. VEGF has been reported to contribute to non-specific airway hyper-responsiveness, have chemotactic effects on eosinophils, and enhance airway smooth muscle cell proliferation. Furthermore, Th2 cells have receptors for VEGF, and Th2-associated cytokines increase VEGF production. There are reports that elevated levels of VEGF correlates with the severity of asthma. Ang-1 has been shown to induce pro-inflammatory effects such as eosinophil chemotaxis via tie-2 receptors. Reports indicate ang-1 contribution to increased secretion of matrix metalloproteinase-2 (MMP-2) and decreased secretion of tissue inhibitors of metalloproteinase-2 (TIMP-2). However, Ang-1 has also been shown to exhibit several anti-inflammatory properties such as suppressing expression of adhesion molecules, blocking vascular permeability and eosinophil chemotaxis induced by VEGF. These findings support the notion that apart from their roles in blood vessels formation, these angiogenic growth factors are directly involved in the pathogenesis of chronic asthma. This paper reviews individual and combined roles of VEGF and Ang-1. The potential therapeutic applications involving these factors are also discussed.     

诱导痰黏蛋白5AC对支气管哮喘和慢性阻塞性肺疾病的鉴别价值

摘要 目的：对支气管哮喘（BA）患者和慢性阻塞性肺疾病（COPD）患者诱导痰黏蛋白5AC（MUC5AC）、炎症细胞和炎症因子水平进行比较以及相关性分析,评估MUC5AC鉴别BA和COPD的价值。方法：选取2018年9月至2019年9月来海南医学院第一附属医院就诊的BA稳定期患者（BA组）60例,同期COPD稳定期（COPD组）患者60例。诱导痰法采样并处理痰液,检测诱导痰MUC5AC、炎症细胞中性粒细胞（Neu）、巨噬细胞（Mac）、嗜酸性粒细胞（Eos）、淋巴细胞（Lym）、炎症因子血管内皮生长因子（VEGF）、细胞间黏附分子-1（ICAM-1）、白介素13（IL-13）和白介素17（IL-17）水平,通过Pearson相关分析对MUC5AC水平与Neu、Mac、Eos、Lym、VEGF、ICAM-1、IL-13、IL-17的关系进行分析。此外,采用受试者工作特征(ROC)曲线分析MUC5AC、炎症细胞及炎症因子鉴别诊断BA及COPD的效能。结果：COPD组诱导痰MUC5AC水平高于BA组,差异有统计学意义（P＜0.05）;COPD组诱导痰Mac和Eos水平均低于BA组,COPD组诱导痰Neu水平高于BA组,差异均有统计学意义（P＜0.05）;COPD组诱导痰VEGF、ICAM-1、IL-13和IL-17水平均低于BA组,差异均有统计学意义（P＜0.05）;Pearson相关分析结果显示,诱导痰MUC5AC与炎症细胞Mac、Eos和炎症因子VEGF、ICAM-1、IL-13和IL-17呈负相关（P＜0.05）,与炎症细胞Neu呈正相关（P＜0.05）。经ROC曲线分析可得：诱导痰MUC5AC鉴别BA和COPD的曲线下面积、灵敏度、特异度以及约登指数均高于炎症细胞Neu、Mac、Eos以及炎症因子VEGF、ICAM-1、IL-13、IL-17。结论：COPD患者诱导痰MUC5AC水平高于BA患者,MUC5AC与炎症细胞和炎症因子有关,MUC5AC的检测有助于鉴别BA或COPD,其有望作为临床BA或COPD的监测指标和治疗靶点。     

Decreased Histone Deacetylase 2 (HDAC2) in Peripheral Blood Monocytes (PBMCs) of COPD Patients

Background

Histone deacetylase 2 (HDAC2) is a class I histone deacetylase family member that plays a critical role in suppressing inflammatory gene expression in the airways, lung parenchyma, and alveolar macrophages in patients with chronic obstructive pulmonary disease (COPD). However, the expression of HDAC2 in peripheral blood monocytes (PBMCs), nuclear factor kappa B (NF-κB) p65, and serum inflammatory cytokine levels in COPD patients, smokers, and non-smokers remains unclear.

Methods

PBMCs were obtained from COPD patients, healthy smokers, and healthy nonsmokers. The HDAC2 and NF-κB p65 expression were quantified by Western Blot. HDAC activity was assessed by an HDAC fluorometric immunoprecipitation activity assay kit. Serum tumor necrosis factor-alpha (TNF-α) and interleukin-8 (IL-8) levels were measured by ELISA.

Results

HDAC2 expression and HDAC activity were decreased in PBMCs in COPD patients compared with smokers and non-smokers. Increased NF-κB p65 expression, serum TNF-α and IL-8 levels were observed in COPD patients compared with nonsmokers. The FEV₁%pred was positively correlated with HDAC2 expression and HDAC activity in COPD patients. Smokers had decreased HDAC activity, increased NF-κB p65 expression and serum TNF-α compared with nonsmokers.

Conclusions

HDAC2 expression was decreased in PBMCs of COPD patients and was correlated with disease severity. The reduction of HDAC2 expression not only directly enhances the expression of inflammatory genes, but may account for the activation of NF-κB mediated inflammation. Decreased HDAC2 may serve as a potential biomarker of COPD and predict the decline of lung function.     

Innate immune responses are increased in chronic obstructive pulmonary disease

Background

Chronic obstructive pulmonary disease (COPD) is characterised by irreversible airflow obstruction, neutrophilic airway inflammation and chronic bacterial colonisation, however the role of the innate immune response in the pathogenesis of COPD remains unclear.

Methods

Induced sputum was obtained from adults with COPD (n = 22), and healthy controls (n = 29) and was processed for differential cell counts. The sputum supernatant was assayed for innate immune mediators using ELISA, whilst sputum gene expression was measured using real-time PCR. Peripheral blood neutrophils were isolated and their response to lipopolysaccaride (LPS) stimulation was assessed in a subgroup of participants with COPD (n = 13) and healthy controls (n = 21).

Results

Participants with COPD had significantly higher protein levels of interleukin (IL)-8, and neutrophil elastase (NE) and detection of oncostatin M (OSM) compared to healthy controls. Gene expression for toll-like receptor (TLR) 2, IL-8 and OSM were also significantly higher in COPD participants. The level of IL-1β, surfactant protein (SP)-A, matrix metalloproteinase (MMP)-9 and TLR4 mRNA was not significantly different between groups. The level of innate immune response markers were highly associated with the presence of sputum neutrophils, each other and the degree of airflow limitation (FEV₁/FVC). Peripheral blood neutrophils from participants with COPD had an increased response to stimulation by LPS; with a greater fold increase in the production of IL-8 and MMP-9 protein, and gene expression of IL-8, TLR2 and TLR4.

Conclusions

The innate immune response is increased in the airways and circulating neutrophils in COPD, and may be an important mechanism involved in disease pathogenesis.     

Smoking status and anti-inflammatory macrophages in bronchoalveolar lavage and induced sputum in COPD

Background

Macrophages have been implicated in the pathogenesis of COPD. M1 and M2 macrophages constitute subpopulations displaying pro- and anti-inflammatory properties. We hypothesized that smoking cessation affects macrophage heterogeneity in the lung of patients with COPD. Our aim was to study macrophage heterogeneity using the M2-marker CD163 and selected pro- and anti-inflammatory mediators in bronchoalveolar lavage (BAL) fluid and induced sputum from current smokers and ex-smokers with COPD.

Methods

114 COPD patients (72 current smokers; 42 ex-smokers, median smoking cessation 3.5 years) were studied cross-sectionally and underwent sputum induction (M/F 99/15, age 62 ± 8 [mean ± SD] years, 42 (31-55) [median (range)] packyears, post-bronchodilator FEV₁ 63 ± 9% predicted, no steroids past 6 months). BAL was collected from 71 patients. CD163⁺ macrophages were quantified in BAL and sputum cytospins. Pro- and anti-inflammatory mediators were measured in BAL and sputum supernatants.

Results

Ex-smokers with COPD had a higher percentage, but lower number of CD163⁺ macrophages in BAL than current smokers (83.5% and 68.0%, p = 0.04; 5.6 and 20.1 ×10⁴/ml, p = 0.001 respectively). The percentage CD163⁺ M2 macrophages was higher in BAL compared to sputum (74.0% and 30.3%, p < 0.001). BAL M-CSF levels were higher in smokers than ex-smokers (571 pg/ml and 150 pg/ml, p = 0.001) and correlated with the number of CD163⁺ BAL macrophages (Rs = 0.38, p = 0.003). No significant differences were found between smokers and ex-smokers in the levels of pro-inflammatory (IL-6 and IL-8), and anti-inflammatory (elafin, and Secretory Leukocyte Protease Inhibitor [SLPI]) mediators in BAL and sputum.

Conclusions

Our data suggest that smoking cessation partially changes the macrophage polarization in vivo in the periphery of the lung towards an anti-inflammatory phenotype, which is not accompanied by a decrease in inflammatory parameters.     

Thalidomide prevents bleomycin-induced pulmonary fibrosis in mice

Pulmonary fibrosis in humans can occur as a result of a large number of conditions. In idiopathic pulmonary fibrosis (IPF), pulmonary function becomes progressively compromised resulting in a high mortality rate. Currently there are no proven effective treatments for IPF. We have recently reported that IL-6 and TGF-beta(1) plays an important role in proliferation and differentiation of lung fibroblasts, and all-trans-retinoic acid (ATRA) prevented bleomycin-induced lung fibrosis through the inhibition of these cytokines. Thalidomide (Thal) has been used in the treatment of multiple myeloma through the inhibitory effect on IL-6-dependent cell growth and angiogenesis. In this study, we examined the preventive effect of Thal on bleomycin-induced pulmonary fibrosis in mice. We performed histological examinations and quantitative measurements of IL-6, TGF-beta(1), collagen type Ialpha1 (COL1A1), vascular endothelial growth factor (VEGF), angiopoietin-1 (Ang-1) and angiopoietin-2 (Ang-2) in bleomycin-treated mouse lung tissues with or without the administration of Thal. Thal histologically ameliorated bleomycin-induced fibrosis in mouse lung tissues. Thal decreased the expressions of IL-6, TGF-beta(1), VEGF, Ang-1 Ang-2, and COL1A1 mRNA in mouse lung tissues. In addition, Thal inhibited angiogenesis in the lung. In vitro studies disclosed that Thal reduced 1) production of IL-6, TGF-beta(1), VEGF, Ang-1, and collagen synthesis from human lung fibroblasts, and 2) both IL-6-dependent proliferation and TGF-beta(1)-dependent transdifferentiation of the cells, which could be the mechanism underlying the preventive effect of Thal on pulmonary fibrosis. These data may provide a rationale to explore clinical use of Thal for the prevention of pulmonary fibrosis.     

Characterization of a novel form of angiopoietin-2 (Ang-2B) and expression of VEGF and angiopoietin-2 during chicken testicular development and regression.

The complex process of angiogenesis is controlled by the vascular endothelial growth factor (VEGF) and its receptors and by the recently isolated angiopoietin-1 (Ang-1) and angiopoietin-2 (Ang-2) that signal through the transmembrane endothelial receptor tyrosine kinase Tie2. We report here the characterization of a novel form of Ang-2 (Ang-2B) with a truncated amino-terminal domain resulting from an alternative splicing of the gene. While previous reports have found the expression of Ang-2 limited to the embryo, female reproductive organs, and tumor tissues, we have observed striking changes in Ang-2 expression during chicken testicular development and regression. The expression of Ang-2 and VEGF is abundant in prepuberal testis and low in quiescent adult testis. Testicular regression is accompanied by high expression of Ang-2 and very low expression of VEGF. These observations are in accordance with the proposal that Ang-2 induces angiogenesis in the presence of VEGF and vascular regression in its absence.