Neutrophil-associated activation markers in healthy smokers relates to a fall in DL(CO) and to emphysematous changes on high resolution CT

Increased plasma interleukin-1β is associated with accelerated lung function decline in non-smokers

Interleukin-1β is one of the major cytokines involved in the initiation and persistence of airway inflammation in chronic obstructive pulmonary disease (COPD). However, the association between plasma interleukin-1β and lung function decline remains unclear. We aimed to explore the association between plasma interleukin-1β and lung function decline. This longitudinal evaluation of data from the Early COPD study analysed the association between the plasma interleukin-1β concentration, lung function decline, and COPD exacerbation. Overall, 1,328 participants were included in the baseline analysis, and 1,135 (85%) completed the 1-year follow-up. Increased plasma interleukin-1β was associated with accelerated lung function decline in non-smokers (forced expiratory volume in 1 s: per unit natural log-transformed increase, adjusted unstandardised β [95% confidence interval] 101.46 [16.73-186.18] mL/year, p=0.019; forced vital capacity: per unit natural log-transformed increase, adjusted unstandardised β [95% confidence interval] 146.20 [93.65-198.75] mL/year, p<0.001), but not in smokers. In non-smokers, participants with an interleukin-1β concentration in the top 30% (>5.02 pg/mL) had more respiratory symptoms, more severe emphysema and air trapping, and higher levels of inflammation-related biomarkers. In this study, a subgroup with increased plasma interleukin-1β was identified among non-smokers, and increased plasma interleukin-1β was associated with lung function accelerated decline.

Roles for Siglec-glycan interactions in regulating immune cells

Cell surface complex carbohydrates, known as glycans, are positioned to be the first point of contact between two cells. Indeed, interactions between glycans with glycan-binding can modulate cell-cell interactions. This concept is particularly relevant for immune cells, which use an array of glycan-binding proteins to help in the process of differentiating 'self' from 'non-self'. This is exemplified by the sialic acid-binding immunoglobulin-type lectins (Siglecs), which recognize sialic acid. Given that sialic acid is relatively unique to vertebrates, immune cells leverage Siglecs to recognize sialic acid as a marker of 'self'. Siglecs serve many biological roles, with most of these functions regulated through interactions with their sialoglycan ligands. In this review, we provide a comprehensive update on the ligands of Siglecs and how Siglec-sialoglycan interactions help regulate immune cells in the adaptive and innate immune system.

Predictive value of cytokines combined with human neutrophil lipocalinin acute ischemic stroke-associated pneumonia

OBJECTIVE

To explore the predictive value of interleukin-6 (IL-6) combined with human neutrophil lipocalin (HNL) of stroke-associated pneumonia (SAP) in patients who were diagnosed with acute ischemic stroke (AIS).

METHODS

108patients were divided into two groups: pneumonia group (52 cases) and non-pneumonia group (56 cases), according to whether the patients developed SAP within 7 days of admission. General information was compared between the two groups, like age, gender, history of hypertension, diabetes mellitus, cardiovascular disease, dysphagia, smoking and alcoholhistory. Clinical data were recorded and compared, including lipid profile, interleukin-6 (IL-6), homocysteine (Hcy), National Institutes of Health Stroke Scale (NIHSS) score, and HNL. Multivariate Logistic regression analysis was used to screen the risk factors of AIS-AP, and the predictive value of IL-6 and HNL alone and in combination was evaluated by receiver operating characteristic curve (ROC curve).

RESULTS

Logistic regression analysis showed that dysphagia (OR,0.018; 95% CI, 0.001 ~ 0.427; P = 0.013), increased NIHSS scores(OR,0.012; 95% CI, 0.000 ~ 0.434; P = 0.016), and high levels of IL-6 (OR,0.014; 95% CI, 0.000 ~ 0.695; P = 0.032)and HNL (OR,0.006; 95% CI, 0.000 ~ 0.280; P = 0.009) were independent risk factors for SAP with significant difference (all P < 0.05). According to the ROC curve analysis of IL-6, the area under the curve (AUC) was 0.881 (95% CI: 0.820 ~ 0.942), and the optimal cutoff value was 6.89 pg/mL with the sensitivity of 73.1% and specificity of 85.7%. As for the ROC curve analysis of HNL, the AUC was 0.896 (95% CI: 0.839 ~ 0.954), and the best cutoff value was 99.66ng/mL with the sensitivity of 76.9% and specificity of 89.3%. The AUC of the combination of IL-6 and HNL increased to 0.952 (95% CI: 0.914 ~ 0.989), and the sensitivity and specificity increased to 80.8% and 92.9%, respectively.

CONCLUSION

In this research, the levels of IL-6 ≥ 6.89 pg/mL and HNL ≥ 99.66ng/mL were considered as risk factors for AIS patients complicated with SAP. The combined detection had higher predictive value for patients with SAP, which may help to identify who were in highrisk.

Mesenchymal stem cells attenuate the proinflammatory cytokine pattern in a guinea pig model of chronic cigarette smoke exposure

AIMS

Cigarette smoke often induces pulmonary and systemic inflammation. In animal models, mesenchymal stem cells (MSC) tend to ameliorate these effects. We aimed to explore the local and systemic expression of cytokines in guinea pigs chronically exposed to cigarette smoke, and their modifications by MSC.

MAIN METHODS

Concentrations of IL-1β, IL-6, IL-8, IL-12, TNF-α, INF-ɣ, TSG-6, MMP-9, TIMP-1, and/or TIMP-2 in serum and bronchoalveolar lavage (BALF) from animals exposed to tobacco smoke (20 cigarettes/day, 5 days/week for 10 weeks) were determined, and mRNA expression of some of them was measured in lung tissue. Intratracheal instillation of allogeneic bone marrow MSC (5x10⁶ cells in 1 ml) was done at week 2.

KEY FINDINGS

After cigarette smoke, IL-6 and IFN-γ increased in serum and BALF, while IL-1β and IL-12 decreased in serum, and TSG-6 and TIMP-2 increased in BALF. IL-1β had a paradoxical increase in BALF. MSC had an almost null effect in unexposed animals. The intratracheal administration of MSC in guinea pigs exposed to cigarette smoke was associated with a statistically significant decrease of IL-12 and TSG-6 in serum, as well as a decrease of IL-1β and IFN-γ and an increase in TIMP-1 in BALF. Concerning mRNA expression in lung tissue, cigarette smoke did not modify the relative amount of the studied transcripts, but even so, MSC decreased the IL-12 mRNA and increased the TIMP-1 mRNA.

SIGNIFICANCE

A single intratracheal instillation of MSC reduces the pulmonary and systemic proinflammatory pattern induced by chronic exposure to cigarette smoke in guinea pigs.

TRIAL REGISTRATION

Not applicable.

Blocking P2X purinoceptor 4 signalling alleviates cigarette smoke induced pulmonary inflammation

Background

Chronic obstructive pulmonary disease (COPD) is associated with elevated ATP levels in the extracellular space. Once released, ATP serves as danger signal modulating immune responses by activating purinergic receptors. Accordingly, purinergic signalling has been implicated in respiratory inflammation associated with cigarette smoke exposure. However, the role of P2X4-signalling has not been fully elucidated yet.

Methods

Here, we analysed the P2X4 mRNA expression in COPD patients as well as cigarette smoke-exposed mice. Furthermore, P2X4-signalling was blocked by either using a specific antagonist or genetic depletion of P2rx4 in mice applied to an acute and prolonged model of cigarette smoke exposure. Finally, we inhibited P2X4-signalling in macrophages derived from THP-1 before stimulation with cigarette smoke extract.

Results

COPD patients exhibited an increased P2X4 mRNA expression in cells isolated from the bronchoalveolar lavage fluid and peripheral mononuclear cells. Similarly, P2rx4 expression was elevated in lung tissue of mice exposed to cigarette smoke. Blocking P2X4-signalling in mice alleviated cigarette smoke induced airway inflammation as well as lung parenchyma destruction. Additionally, human macrophages derived from THP-1 cells released reduced concentrations of proinflammatory cytokines in response to cigarette smoke extract stimulation when P2X4 was inhibited.

Conclusion

Taken together, we provide evidence that P2X4-signalling promotes innate immunity in the immunopathologic responses induced by cigarette smoke exposure.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12931-022-02072-z.

Analysis of differentially expressed genes and signaling pathways involved in atherosclerosis and chronic obstructive pulmonary disease

Atherosclerosis is an important medical and social problem, and the keys to solving this problem are still largely unknown. A common situation in real clinical practice is the comorbid course of atherosclerosis with chronic obstructive pulmonary disease (COPD). Diseases share some common risk factors and may be closely linked pathogenetically.

METHODS

Bioinformatics analysis of datasets from Gene Expression Omnibus (GEO) was performed to examine the gene ontology (GO) of common differentially expressed genes (DEGs) in COPD and peripheral arterial atherosclerosis. DEGs were identified using the limma R package with the settings p < 0.05, corrected using the Benjamini & Hochberg algorithm and ǀlog 2FCǀ > 1.0. The GO, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment, and the protein-protein interaction (PPI) network analysis were performed with the detected DEGs.

RESULTS

The biological processes and signaling pathways involving common DEGs from airway epithelial datasets in COPD and tissue in peripheral atherosclerosis were identified. A total of 15 DEGs were identified, comprising 12 upregulated and 3 downregulated DEGs. The GO enrichment analysis demonstrated that the upregulated hub genes were mainly involved in the inflammatory response, reactive oxygen species metabolic process, cell adhesion, lipid metabolic process, regulation of angiogenesis, icosanoid biosynthetic process, and cellular response to a chemical stimulus. The KEGG pathway enrichment analysis demonstrated that the common pathways were Toll-like receptor signaling pathway, NF-kappa B signaling pathway, lipid and atherosclerosis, and cytokine-cytokine receptor interaction.

CONCLUSIONS

Biological processes and signaling pathways associated with the immune response may link the development and progression of COPD and atherosclerosis.

ACO (Asthma-COPD Overlap) Is Independent from COPD, a Case in Favor: A Systematic Review

Asthma and chronic obstructive pulmonary disease (COPD) are now recognized to be able to co-exist as asthma-COPD overlap (ACO). It is clinically relevant to evaluate whether patients with COPD concurrently have components of asthma in primary care. This is because: (i) ACO is a relatively common condition among asthma (over 40 years of age) or COPD irrespective of its diagnosis criteria; (ii) patients with ACO can have higher frequency of exacerbation and more rapid decline in lung function than those with asthma or COPD; and (iii) asthmatic features such as eosinophilic airway inflammation are promising indicators for prediction of inhaled corticosteroid-responsiveness in COPD. The aim of this review to evaluate diagnostic markers for ACO. We searched PubMed for articles related to ACO published until 2020. Articles associated with diagnostic biomarkers were included. We identified a total of 25 studies, some of which have revealed that a combination of biomarkers such as fractional exhaled nitric oxide and serum immunoglobulin E is useful to discern type 2 inflammation in the airways of COPD. Here, we review the current understanding of the clinical characteristics, biomarkers and molecular pathophysiology of ACO in the context of how ACO can be differentiated from COPD.

Serum Neutrophil Gelatinase-associated Lipocalin (NGAL) Is Elevated in Patients with Asthma and Airway Obstruction

Neutrophilic airway inflammation is one of the features of severe asthma. Neutrophil gelatinase-associated lipocalin (NGAL), or lipocalin-2, is a glycoprotein associated with neutrophilic inflammation and can be detected in blood. Recently, blood NGAL levels have been reported to be elevated in chronic obstructive pulmonary disease. However, the clinical significance of serum NGAL levels in patients with asthma has not been elucidated. The aim of this study was to explore the association between serum NGAL level and clinical parameters in patients with asthma. Sixty-one non-smoking people with stable asthma were enrolled in this study. All patients underwent blood collection and pulmonary function tests. The associations between serum NGAL levels and clinical parameters were analyzed retrospectively. Serum NGAL levels in patients with asthma and obstructive ventilatory defect were higher than those in patients with asthma without obstructive ventilatory defect (76.4±51.4 ng/mL vs. 39.3±27.4 ng/mL, P=0.0019). Serum NGAL levels were correlated with forced expired flow at 50% of vital capacity %predicted and forced expired flow at 75% of vital capacity %predicted (r=-0.3373, P=0.0078 and r=-0.2900, P=0.0234, respectively). Results of a multiple regression analysis demonstrated that serum NGAL level was independently associated with obstructive ventilatory defect. Serum NGAL levels were elevated in patients with asthma and obstructive ventilatory defect. NGAL may be involved in airway remodeling possibly mediated by neutrophilic inflammation in asthma.

E-cigarettes and health risks: more to the flavor than just the name

The growing interest in regulating flavored E-liquids must incorporate understanding of the "flavoring profile" of each E-liquid-which flavorings (flavoring chemicals) are present and at what concentrations not just focusing on the flavor on the label. We investigated the flavoring profile of 10 different flavored E-liquids. We assessed bronchial epithelial cell viability and apoptosis, phagocytosis of bacteria and apoptotic cells by macrophages after exposure to E-cigarette vapor extract (EVE). We validated our data in normal human bronchial epithelial cells (NHBE) and alveolar macrophages (AM) from healthy donors. We also assessed cytokine release and validated in the saliva from E-cigarette users. Increased necrosis/apoptosis (16.1-64.5% apoptosis) in 16HBE cells was flavor dependent, and NHBEs showed an increased susceptibility to flavors. In THP-1 differentiated macrophages phagocytosis was also flavor dependent, with AM also showing increased susceptibility to flavors. Further, Banana and Chocolate were shown to reduce surface expression of phagocytic target recognition receptors on alveolar macrophages. Banana and Chocolate increased IL-8 secretion by NHBE, whereas all 4 flavors reduced AM IL-1β secretion, which was also reduced in the saliva of E-cigarette users compared with healthy controls. Flavorant profiles of E-liquids varied from simple 2 compound mixtures to complex mixtures containing over a dozen flavorants. E-liquids with high benzene content, complex flavoring profiles, high chemical concentration had the greatest impacts. The Flavorant profile of E-liquids is key to disruption of the airway status quo by increasing bronchial epithelial cell apoptosis, causing alveolar macrophage phagocytic dysfunction, and altering airway cytokines.

Current perspectives on the role of interleukin-1 signalling in the pathogenesis of asthma and COPD

Asthma and chronic obstructive pulmonary disease (COPD) cause significant morbidity and mortality worldwide. In the context of disease pathogenesis, both asthma and COPD involve chronic inflammation of the lung and are characterised by the abnormal release of inflammatory cytokines, dysregulated immune cell activity and remodelling of the airways. To date, current treatments still only manage symptoms and do not reverse the primary disease processes. In recent work, interleukin (IL)-1α and IL-1β have been suggested to play important roles in both asthma and COPD. In this review, we summarise overwhelming pre-clinical evidence for dysregulated signalling of IL-1α and IL-1β contributing to disease pathogenesis and discuss the paradox of IL-1 therapeutic studies in asthma and COPD. This is particularly important given recent completed and ongoing clinical trials with IL-1 biologics that have had varying degrees of failure and success as therapeutics for disease modification in asthma and COPD.

Diagnosis and Monitoring of Acute Infections with Emphasis on the Novel Biomarker Human Neutrophil Lipocalin

Background

Acute infections affect all of us at least once or twice a year. Sometimes the infection prompts a visit to our doctor, and the question asked by the patient and the doctor is whether the infection should be treated with antibiotics or not. This is an important question because unnecessary prescription of antibiotics adds to the increasing problem of antibiotics resistance. Objective means to determine whether the infection is caused by bacteria or virus, therefore, are necessary tools for the doctor.

Content

White blood cell counts, C-reactive protein, and other acute-phase reactants in blood are important tools and are commonly used, but unfortunately lack in sensitivity and specificity. In this review we describe some novel biomarkers with increased clinical performance in this regard. The superior biomarker is human neutrophil lipocalin (HNL), a protein released from activated blood neutrophils. HNL may be measured in serum, plasma, or in whole blood after activation with a neutrophil activator. The diagnostic accuracy in the distinction between bacterial and viral acute infections was shown to be in the range of 90%–95% when measured in serum or activated whole blood.

Summary

A point-of-care assay for the measurement of HNL in whole blood is currently being developed, which will allow the diagnosis of acute infections within 5–10 min. For certain indications, HNL measurement may be complemented by 1 or 2 other biomarkers, which may increase the diagnostic discrimination between bacterial and viral infections even further.

Neutrophil gelatinase-associated lipocalin as a complementary biomarker for the asthma-chronic obstructive pulmonary disease overlap

Background

There is no standardized definition of the asthma-chronic obstructive pulmonary disease (COPD) overlap (ACO). Although the blood eosinophil count is regarded as a biomarker for identifying ACO, it has no distinct value. This study aimed to measure plasma levels of neutrophil gelatinase-associated lipocalin (NGAL), a potential biomarker for distinguishing between ACO and non-ACO COPD.

Methods

We used the Korean cohort in the COPD in dusty area (CODA) study which included 137 subjects with COPD confirmed by spirometry. We defined ACO by a positive bronchodilator response (forced expiratory volume in 1 s, FEV₁ >12% and >200 mL from baseline) or based on a previous history of asthma. Plasma levels of NGAL were determined by enzyme immunoassay.

Results

Among the 137 subjects, 77 were ACO and 60 were non-ACO COPD. Overall, the plasma NGAL levels were 15.9±7.9 and 15.6±6.6 ng/mL for non-ACO and ACO subjects respectively, and not significantly different. However, NGAL levels were significantly higher in female subjects with ACO (17.0±6.4 vs. 11.1±4.5, P=0.01). In female subjects, NGAL levels showed a good predictive ability to discriminate between ACO and non-ACO COPD [area under the receiver operating characteristic curve (AUROC), 0.77]; the predictive ability was similar to that of the blood eosinophil count (AUROC, 0.79). There was a higher probability of discriminating ACO from non-ACO among subjects in the highest tertile of NGAL levels (odds ratio, 1.72; 95% confidence interval, 0.69-4.28; P for trend =0.01).

Conclusions

NGAL levels were significantly higher in ACO compared to non-ACO COPD in female subjects. After adjusting for gender as a confounding factor, the ability to distinguish ACO was better at higher levels of NGAL.

Plasma YKL-40 and NGAL are useful in distinguishing ACO from asthma and COPD

BACKGROUND

Asthma-chronic obstructive pulmonary disorder (COPD) overlap (ACO) is characterized by the coexistence of features of both asthma and COPD and is associated with rapid progress and a poor prognosis. Thus, the early recognition of ACO is crucial.

OBJECTIVES

We sought to explore the plasma levels of biomarkers associated with asthma (periostin, TSLP and YKL-40), COPD (NGAL) and their possible correlation with lung function, the bronchodilator response and radiographic imaging in patients with asthma, COPD and with features of ACO.

METHODS

We enrolled 423 subjects from 6 clinical centers. All participants underwent blood collection, lung function measurements, bronchodilator response tests and high-resolution CT. Correlations of the plasma biomarkers with lung function, the bronchodilator response and percentemphysema were calculated by Spearman's rank correlation and multivariate stepwise regressionanalysis.

RESULTS

1) Patients with features of ACO had lower plasma YKL-40 than COPD patients and a moderate elevated plasma level of NGAL compared with asthma patients. 2) Patients with features of ACO had an intermediate degree of airflow obstruction, the bronchodilator response and emphysema between patients with COPD and asthma. 3) Plasma YKL-40 was negatively correlated with lung function and with the bronchodilator response, and plasma NGAL was positively correlated with the extent of emphysema.

CONCLUSIONS

Plasma YKL-40 is a promising candidate for distinguishing between patients with features of ACO and COPD patients, while plasma NGAL may be a valuable biomarker for differentiating between patients with features of ACO and asthma patients.

CLINICAL TRIAL REGISTRATION

ChiCTR-OOC-16009221.

Human neutrophil lipocalin (HNL) as a biomarker of acute infections

The early and accurate discrimination between bacterial and viral causes of acute infections is the key to a better use of antibiotics and will help slow down the fast-growing resistance to commonly used antibiotics. This discrimination is in the vast majority of cases possible to achieve by blood assay of the biomarker human neutrophil lipocalin (HNL), which we showed to be uniquely increased in patients suffering from bacterial infections. In serum, sensitivities and specificities of >90% are achieved in both adults and children. In order to eliminate the need to produce serum, a whole-blood assay with an assay time of <10 min was developed in which blood neutrophils are activated to release HNL. The diagnostic accuracy of this assay also showed sensitivities and specificities of >90% in most infectious diseases and was clearly superior to contemporary assays such as blood neutrophil counts, C-reactive protein, procalcitonin, and expression of CD64 on blood neutrophils. This format lends itself to the development of a point-of-care HNL assay and will be a major step forward to accomplish the goal of accurately diagnosing patients with symptoms of acute infections within 10 min at the emergency room or at the doctor's office.

p-Coumaric Acid, a Major Active Compound of Bambusae Caulis in Taeniam, Suppresses Cigarette Smoke-Induced Pulmonary Inflammation

[Formula: see text]-coumaric acid ([Formula: see text]-CA) is a common compound found in medicinal herbs, including Bambusae Caulis in Taeniam (BC). It has been used to treat various diseases in China and Korea. Our previous study demonstrated that BC inhibits pulmonary and intestinal inflammation. In the present study, we used cigarette smoke (CS) to induce lung inflammation in vivo, and investigated the anti-inflammatory effects of [Formula: see text]-CA on CS-induced inflammatory mice model. Mice were treated with BC and [Formula: see text]-CA via oral injection 2[Formula: see text]h before CS exposure. The body weight and the inflammatory cells in the bronchoalveolar lavage fluid were measured. The levels of relative inflammatory factors were confirmed by enzyme-linked immunosorbent assay. The lung histological changes were examined by hematoxylin and eosin staining. Also, the protein level of nuclear factor-[Formula: see text]B (NF-[Formula: see text]B) was evaluated by Western blotting. Our results indicated that BC and [Formula: see text]-CA inhibited CS-induced lung inflammation by regulating pro-inflammatory productions such as cytokines, chemokine, protease and NF-[Formula: see text]B. Consequently, these data demonstrated that [Formula: see text]-CA inhibited pulmonary inflammation by suppressing NF-[Formula: see text]B activity, through which pro-inflammatory mediators were regulated. Therefore, [Formula: see text]-CA, which was shown to be a major component of BC, can be considered as a strong therapeutic candidate for treating pulmonary inflammatory diseases.

Luminally expressed gastrointestinal biomarkers

A biomarker is a measurable indicator of normal biologic processes, pathogenic processes or pharmacological responses. The identification of a useful biomarker is challenging, with several hurdles to overcome before clinical adoption. This review gives a general overview of a range of biomarkers associated with inflammatory bowel disease or colorectal cancer along the gastrointestinal tract. Areas covered: These markers include those that are already clinically accepted, such as inflammatory markers such as faecal calprotectin, S100A12 (Calgranulin C), Fatty Acid Binding Proteins (FABP), malignancy markers such as Faecal Occult Blood, Mucins, Stool DNA, Faecal microRNA (miRNA), other markers such as Faecal Elastase, Faecal alpha-1-antitrypsin, Alpha2-macroglobulin and possible future markers such as microbiota, volatile organic compounds and pH. Expert commentary: There are currently a few biomarkers that have been sufficiently validated for routine clinical use at present such as FC. However, many of these biomarkers continue to be limited in sensitivity and specificity for various GI diseases. Emerging biomarkers have the potential to improve diagnosis and monitoring but further study is required to determine efficacy and validate clinical utility.

Increased expression of Siglec-9 in chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is a common inflammatory lung disease. Sialic acid-binding immunoglobulin-type lectins 9 (Siglec-9) is predominantly expressed on innate immune cells and has been shown to exert regulatory effect on immune cells through glycan recognition. Soluble Siglec-9 (sSiglec-9), the extracellular region of Siglec-9, might fulfill its function partly by competitive inhibiting siglec-9 binding to its ligands; however, the role of Siglec-9 and sSiglec-9 in the pathogenesis COPD remain largely unknown. In this study, we showed that Siglec-9 expression in alveolar and peripheral blood neutrophil were increased in COPD patients by immunofluorescence and flow cytometry, respectively. Plasma levels of sSiglelc-9 were elevated in COPD patients by ELISA. In vitro, Siglec-9 expression and/or sSiglelc-9 levels were up-regulated by cigarette smoke extract (CSE), lipopolysaccharide (LPS), some cytokines, and dexamethasone (DEX). Recombinant sSiglce-9 increased oxidative burst in neutrophil and enhanced neutrophil chemotaxis toward IL-8 independent on CXCR1 and CXCR2 expression, but it did not affect neutrophil apoptosis or secretions of inflammatory cytokines. In conclusion, Siglec-9 was complementarily increased to induce a negative feedback loop to limit neutrophil activation in COPD, sSiglce-9 enhanced neutrophil ROS and chemotaxis toward IL-8 likely via competitively inhibiting ligands binding to Siglec-9.

Differences in regional air trapping in current smokers with normal spirometry

We investigated regional air trapping on computed tomography in current smokers with normal spirometry. It was hypothesised that presence of regional air trapping may indicate a specific manifestation of smoking-related changes.

40 current smokers, 40 patients with chronic obstructive pulmonary disease (COPD), and 40 healthy never- smokers underwent computed tomography scans. Regional air trapping was assessed on end-expiratory scans and emphysema, micronodules and bronchial wall thickening on inspiratory scans. The ratio of expiratory and inspiratory mean lung attenuation (E/I) was calculated as a measure of static (fixed) air trapping.

Regional air trapping was present in 63% of current smokers, in 45% of never smokers and in 8% of COPD patients (p<0.001). Current smokers with and without regional air trapping had E/I ratio of 0.81 and 0.91, respectively (p<0.001). Forced expiratory volume in 1 s (FEV1) was significantly higher and emphysema less frequent in current smokers with regional air trapping.

Current smokers with regional air trapping had higher FEV1 and less emphysema on computed tomography. In contrast, current smokers without regional air trapping resembled COPD. Our results highlight heterogeneity among smokers with normal spirometry and may contribute to early detection of smoking related structural changes in the lungs.

Surfactant protein D, Club cell protein 16, Pulmonary and activation-regulated chemokine, C-reactive protein, and Fibrinogen biomarker variation in chronic obstructive lung disease

Chronic obstructive pulmonary disease (COPD) is a multifaceted condition that cannot be fully described by the severity of airway obstruction. The limitations of spirometry and clinical history have prompted researchers to investigate a multitude of surrogate biomarkers of disease for the assessment of patients, prediction of risk, and guidance of treatment. The aim of this review is to provide a comprehensive summary of observations for a selection of recently investigated pulmonary inflammatory biomarkers (Surfactant protein D (SP-D), Club cell protein 16 (CC-16), and Pulmonary and activation-regulated chemokine (PARC/CCL-18)) and systemic inflammatory biomarkers (C-reactive protein (CRP) and fibrinogen) with COPD. The relevance of these biomarkers for COPD is discussed in terms of their biological plausibility, their independent association to disease and hard clinical outcomes, their modification by interventions, and whether changes in clinical outcomes are reflected by changes in the biomarker.

Role of the inflammasome-caspase1/11-IL-1/18 axis in cigarette smoke driven airway inflammation: an insight into the pathogenesis of COPD

BACKGROUND

Chronic Obstructive Pulmonary Disease (COPD) is an inflammatory airway disease often associated with cigarette smoke (CS) exposure. The disease is increasing in global prevalence and there is no effective therapy. A major step forward would be to understand the disease pathogenesis. The ATP-P2X7 pathway plays a dominant role in murine models of CS induced airway inflammation, and markers of activation of this axis are upregulated in patients with COPD. This strongly suggests that the axis could be important in the pathogenesis of COPD. The aim of this study was to perform a detailed characterisation of the signalling pathway components involved in the CS-driven, P2X7 dependent airway inflammation.

METHODS

We used a murine model system, bioassays and a range of genetically modified mice to better understand this complex signalling pathway.

RESULTS

The inflammasome-associated proteins NALP3 and ASC, but not IPAF and AIM2, are required for CS-induced IL-1β/IL-18 release, but not IL-1α. This was associated with a partial decrease in lung tissue caspase 1 activity and BALF neutrophilia. Mice missing caspase 1/11 or caspase 11 had markedly attenuated levels of all three cytokines and neutrophilia. Finally the mechanism by which these inflammatory proteins are involved in the CS-induced neutrophilia appeared to be via the induction of proteins involved in neutrophil transmigration e.g. E-Selectin.

CONCLUSION

This data indicates a key role for the P2X7-NALP3/ASC-caspase1/11-IL-1β/IL-18 axis in CS induced airway inflammation, highlighting this pathway as a possible therapeutic target for the treatment of COPD.

Pathophysiology of tobacco smoke exposure: recent insights from comparative and redox proteomics

First-hand and second-hand tobacco smoke are causally linked to a huge number of deaths and are responsible for a broad spectrum of pathologies such as cancer, cardiovascular, respiratory, and eye diseases as well as adverse effects on female reproductive function. Cigarette smoke is a complex mixture of thousands of different chemical species, which exert their negative effects on macromolecules and biochemical pathways, both directly and indirectly. Many compounds can act as oxidants, pro-inflammatory agents, carcinogens, or a combination of these. The redox behavior of cigarette smoke has many implications for smoke related diseases. Reactive oxygen and nitrogen species (both radicals and non-radicals), reactive carbonyl compounds, and other species may induce oxidative damage in almost all the biological macromolecules, compromising their structure and/or function. Different quantitative and redox proteomic approaches have been applied in vitro and in vivo to evaluate, respectively, changes in protein expression and specific oxidative protein modifications induced by exposure to cigarette smoke and are overviewed in this review. Many gel-based and gel-free proteomic techniques have already been used successfully to obtain clues about smoke effects on different proteins in cell cultures, animal models, and humans. The further implementation with other sensitive screening techniques could be useful to integrate the comprehension of cigarette smoke effects on human health. In particular, the redox proteomic approach may also help identify biomarkers of exposure to tobacco smoke useful for preventing these effects or potentially predictive of the onset and/or progression of smoking-induced diseases as well as potential targets for therapeutic strategies.

Innate immunity but not NLRP3 inflammasome activation correlates with severity of stable COPD

Background

In models of COPD, environmental stressors induce innate immune responses, inflammasome activation and inflammation. However, the interaction between these responses and their role in driving pulmonary inflammation in stable COPD is unknown.

Objectives

To investigate the activation of innate immunity and inflammasome pathways in the bronchial mucosa and bronchoalveolar lavage (BAL) of patients with stable COPD of different severity and control healthy smokers and non-smokers.

Methods

Innate immune mediators (interleukin (IL)-6, IL-7, IL-10, IL-27, IL-37, thymic stromal lymphopoietin (TSLP), interferon γ and their receptors, STAT1 and pSTAT1) and inflammasome components (NLRP3, NALP7, caspase 1, IL-1β and its receptors, IL-18, IL-33, ST2) were measured in the bronchial mucosa using immunohistochemistry. IL-6, soluble IL-6R, sgp130, IL-7, IL-27, HMGB1, IL-33, IL-37 and soluble ST2 were measured in BAL using ELISA.

Results

In bronchial biopsies IL-27+ and pSTAT1+ cells are increased in patients with severe COPD compared with control healthy smokers. IL-7+ cells are increased in patients with COPD and control smokers compared with control non-smokers. In severe stable COPD IL-7R+, IL-27R+ and TSLPR+ cells are increased in comparison with both control groups. The NALP3 inflammasome is not activated in patients with stable COPD compared with control subjects. The inflammasome inhibitory molecules NALP7 and IL-37 are increased in patients with COPD compared with control smokers. IL-6 levels are increased in BAL from patients with stable COPD compared with control smokers with normal lung function whereas IL-1β and IL-18 were similar across all groups.

Conclusions

Increased expression of IL-27, IL-37 and NALP7 in the bronchial mucosa may be involved in progression of stable COPD.

The role of lipocalins in airway disease

The pathogenesis of allergic airway inflammation and disease is complex and still not fully understood. Many cells, factors and mediators are involved in the different aspects of induction, maintenance and persistence of airway inflammation. The heterogeneity and redundancy of this system is one of the main reasons why novel therapeutic targets focusing on the pathogenesis of asthma only hesitantly reach the market and clinical application. Thus, it seems mandatory that we proceed in our efforts to better understand this micro cosmos to succeed in the development of safe and effective drugs for the treatment of more severe and refractory forms of asthma and chronic obstructive pulmonary disease. One of the more recently discovered mediators in the context of airway inflammation are the lipocalins (Lcns). They are a family of proteins that share functional and structural similarities and are involved in the transport of small hydrophobic molecules such as steroids and lipids into the cell. Lcns are found in many different cell types from plants and bacteria through invertebrate cells to cells of vertebrate origin. The purpose of this review is to summarize the role of Lcns in airway diseases, focusing on allergic and infectious inflammation. In particular, we will summarize the present knowledge about Lipocalin 1 and Lipocalin 2, where exciting new discoveries in the recent years have highlighted their role in pulmonary disease and infection. This new class of proteins is another putative candidate for the development of novel drugs against airway inflammation.

Aberrant neutrophil functions in stable chronic obstructive pulmonary disease: the neutrophil as an immunotherapeutic target

Chronic obstructive pulmonary disease (COPD) is a common, progressive and debilitating chronic inflammatory condition affecting the lungs, with significant systemic manifestations and co-morbidities. Smoking cigarettes is the main risk factor, but only a fifth of smokers have clinically significant airflow obstruction and the inflammation persists after smoking cessation. This suggests that smoking (and exposure to other inhaled toxins) may be necessary but not sufficient to cause COPD. Neutrophils are believed central to COPD and their accumulation and degranulation are associated with tissue damage, increased inflammation and disordered tissue repair. It was assumed that neutrophil activity and function were appropriate in COPD, responding to the presence of high levels of inflammation in the lung. However more recent studies of neutrophil function (including migration, reactive oxygen species generation, degranulation, phagocytosis and extracellular trap (NET) production) suggest that there is a general impairment in COPD neutrophil responses that predispose towards increased inflammation and reduced bacterial clearance. This may be amenable to correction and manipulating neutrophil intracellular pathways (such as phosphoinositide-3-kinase signalling) appears to restore some key COPD neutrophil responses. Targeting neutrophil intra-cellular signalling may provide a means to normalise neutrophil behaviour in COPD. This could lead to improvements in disease outcomes by reducing extraneous inflammatory burden. However further studies are needed to determine if these findings are relevant in vivo and whether this would impact positively upon health and disease.

Lilium lancifolium Thunb. extract attenuates pulmonary inflammation and air space enlargement in a cigarette smoke-exposed mouse model

ETHNOPHARMACOLOGICAL RELEVANCE

Lilium lancifolium Thunb. (Liliaceae) has long been used as a traditional medicine in Korea and China to treat bronchitis, pneumonia, and other pulmonary ailments.

AIM OF THE STUDY

Cigarette smoke (CS) is a major risk factor for the development of pulmonary inflammatory response; it also triggers pulmonary alveoli enlargement. In the present study, we investigate the effects of Lilium lancifolium Thunb. root extract on pulmonary inflammatory responses in a CS-exposed mouse model.

MATERIALS AND METHODS

Water extract of Lilium lancifolium Thunb. root was fed to C57BL/6 mice prior CS exposure every day for 3 weeks. The numbers of macrophages and neutrophils in bronchoalveolar lavage fluid (BALF) were counted. The relative inflammatory factors, tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), interleukin-1 beta (IL-1β), monocyte chemotactic protein-1 (MCP-1), and matrix metalloproteinase-12 (MMP-12) were measured by real-time PCR, ELISA, or Western blot analysis. The average alveoli size was determined by lung histology.

RESULTS

Lilium lancifolium Thunb. root extract was found to significantly inhibit the numbers of macrophages and neutrophils in BALF due to CS exposure. Lilium lancifolium Thunb. root extract also reduced the protein secretion levels of TNF-α, IL-6, IL-1β, and MCP-1 in BALF and the RNA expression levels of TNF-α, IL-6, IL-1β, MCP-1, and MMP-12 in lung tissue compared with mice only exposed to CS. Moreover, MMP-12 in serum was down regulated in Lilium lancifolium Thunb. root extract treated mice compared with CS-exposed mice. Finally, a morphometric analysis of the lungs of Lilium lancifolium Thunb. root extract treated mice demonstrated a significant reduction in airspace size compared to mice only exposed to CS.

CONCLUSION

Our results show that Lilium lancifolium Thunb. root extract reduces lung inflammation and airspace enlargement in a CS-exposed mouse model. These data indicate that Lilium lancifolium Thunb. root extract is a therapeutic candidate for pulmonary inflammation and emphysema caused by CS.

Treating neutrophilic inflammation in COPD by targeting ALX/FPR2 resolution pathways

Neutrophilic inflammation persists in COPD despite best current therapies and it is particularly resistant to inhaled glucocorticosteroids. Persistent neutrophil activation not only contributes to matrix breakdown, but can maintain inflammation through the release of endogenous damage associated molecule patterns (DAMPs). Inhibiting excessive neutrophilic inflammation is challenging as many pathogen recognition receptors can initiate migration and the targeting of downstream signaling molecules may compromise essential host defense mechanisms. Here, we discuss new strategies to combat this inflammation in COPD by focusing on the anti-inflammatory role of ALX/FPR2 receptors. ALX/FPR2 is a promiscuous G-protein coupled receptor (GPCR) responding to lipid and peptide agonists that can either switch on acute inflammation or promote resolution of inflammation. We highlight this receptor as an emerging target in the pathogenesis of COPD because known ALX/FPR2 endogenous agonists are enriched in COPD. Serum Amyloid A (SAA) has recently been discovered to be abundantly expressed in COPD and is a potent ALX/FPR2 agonist that unlike almost all other inflammatory chemoattractants, is induced by glucocorticosteroids. SAA not only initiates lung inflammation via ALX/FPR2 but can allosterically modify this receptor so that it no longer transduces pro-resolving signals from endogenous lipoxins that would otherwise promote tissue healing. We propose that there is an imbalance in endogenous and microbial ALX/FPR2 receptor agonists in the inflamed COPD lung environment that oppose protective anti-inflammatory and pro-resolution pathways. These insights open the possibility of targeting ALX/FPR2 receptors using synthetic agonists to resolve persistent neutrophilic inflammation without compromising essential host defense mechanisms.

Serum lysozyme - a surrogate marker of pulmonary microvascular injury in smokers?

Progression rate of disease processes in smoke-induced lung injuries varies greatly. Diverse pathophysiological mechanisms may trigger these divergences. The aim of this study was to evaluate whether circulating markers of monocytes/macrophages and/or neutrophil [i.e. lysozyme (LZM) or myeloperoxidase (MPO)] were associated with reduced values of diffusion capacity (DL,CO), which is considered to serve as a mirror of pulmonary microvascular derangement and an early sign of tissue remodelling in smokers. Data obtained from 134 smokers (GOLD stage ≤1) and 24 matched healthy non-smoking volunteers were evaluated in a cross-sectional study design. Lung function tests as well as single breath test of DL,CO were assessed according to ATS/ERS guidelines. Biomarkers were measured in serum by means of sensitive immunoassays. A subgroup of smokers with normal lung function was created to minimize confounding, by excluding datasets showing significant airflow limitation and abnormally high values of carboxy haemoglobin (COHb), the latter indicating recent smoking. The capacity of serum lysozyme to correctly identify abnormally low values of DL,CO (i.e. <1·9SD units), tended to be higher than that of Myeloperoxidase as assessed by analyses of receiver operated curves (ROC; AUC 0·81, 95%CI: 0·69-0·89 versus AUC 0·67, 95%CI: 0·60-0·81). It is concluded that serum levels of lysozyme, reflecting mainly activated monocytes/macrophages but also neutrophils, were significantly associated with isolated decrements of DL,CO in smokers with normal lung function tests. This suggests monocytes/macrophages to have a significant mechanistic role in early phases of the disease process and/or pulmonary microvascular damage.

The α(1)AT and TIMP-1 Gene Polymorphism in the Development of Asthma

Asthma has been an inflammatory disorder accompanied by tissue remodeling and protease-antiprotease imbalance in lungs. The SNPs of alpha-1 antitrypsin (α(1)AT) and tissue inhibitor of metalloproteinase-1 (TIMP-1) genes were studied for their association with asthma. Genotyping of α(1)AT and TIMP-1 genes was performed in 202 asthmatics and 204 controls. Serum levels of α(1)AT, TIMP-1 and cytokines were estimated to find if the interplay between genotypes and cellular biomarkers determines the pathogenesis of asthma. The analysis of results showed significantly low level of α(1)AT in the serum of asthmatics as compared to controls (P = 0.001), whereas cytokines were elevated in patients. No significant difference was observed in the concentration of TIMP-1 in patients and controls. Genotyping led to the identification of 3 SNPs (Val213Ala, Glu363Lys, and Glu376Asp) in α(1)AT gene. The novel SNP Glu363Lys of α(1)AT was found to be associated with asthma (P = 0.001). The analysis of TIMP-1 gene showed the occurrence of seven SNPs, including a novel intronic SNP at base G3774A. The allele frequency of G3774A and Phe124Phe was significantly higher in asthmatics as compared to controls. Thus, the SNP Glu363Lys of α(1)AT and G3774A and Phe124Phe of TIMP-1 could be important genetic markers for use in better management of the disease.

Profiling of differentially expressed genes using suppression subtractive hybridization in an equine model of chronic asthma

Background

Gene expression analyses are used to investigate signaling pathways involved in diseases. In asthma, they have been primarily derived from the analysis of bronchial biopsies harvested from mild to moderate asthmatic subjects and controls. Due to ethical considerations, there is currently limited information on the transcriptome profile of the peripheral lung tissues in asthma.

Objective

To identify genes contributing to chronic inflammation and remodeling in the peripheral lung tissue of horses with heaves, a naturally occurring asthma-like condition.

Methods

Eleven adult horses (6 heaves-affected and 5 controls) were studied while horses with heaves were in clinical remission (Pasture), and during disease exacerbation induced by a 30-day natural antigen challenge during stabling (Challenge). Large peripheral lung biopsies were obtained by thoracoscopy at both time points. Using suppression subtractive hybridization (SSH), lung cDNAs of controls (Pasture and Challenge) and asymptomatic heaves-affected horses (Pasture) were subtracted from cDNAs of horses with heaves in clinical exacerbation (Challenge). The differential expression of selected genes of interest was confirmed using quantitative PCR assay.

Results

Horses with heaves, but not controls, developed airway obstruction when challenged. Nine hundred and fifty cDNA clones isolated from the subtracted library were screened by dot blot array and 224 of those showing the most marked expression differences were sequenced. The gene expression pattern was confirmed by quantitative PCR in 15 of 22 selected genes. Novel genes and genes with an already defined function in asthma were identified in the subtracted cDNA library. Genes of particular interest associated with asthmatic airway inflammation and remodeling included those related to PPP3CB/NFAT, RhoA, and LTB4/GPR44 signaling pathways.

Conclusions

Pathways representing new possible targets for anti-inflammatory and anti-remodeling therapies for asthma were identified. The findings of genes previously associated with asthma validate this equine model for gene expression studies.

Tobacco smoke regulates the expression and activity of microsomal prostaglandin E synthase-1: role of prostacyclin and NADPH-oxidase

Tobacco smoke (TS) interacts with interleukin-1β (IL-1β) to modulate generation of reactive oxygen species (ROS) and expression of cyclooxygenase-2. We explored molecular mechanisms by which TS/IL-1β alters expression and activity of microsomal-prostaglandin E synthase-1 (mPGES-1) and of prostacyclin synthase (PGIS) in mouse cardiac endothelial cells. TS (EC(50) ∼5 puffs/L) interacting with IL-1β (2 μg/L) up-regulates PGE(2) production and mPGES-1 expression, reaching a plateau at 4-6 h, but down-regulates prostacyclin (PGI(2)) release by increasing IL-1β-mediated PGIS tyrosine nitration. Inhibition of NADPH-oxidase, achieved pharmacologically and/or by silencing its catalytic subunit p47phox, or exogenous PGI(2) (carbaprostacyclin; IC(50) ∼5 μM) prevents production of both ROS and PGE(2), and negatively modulates mPGES-1 expression induced by TS/IL-1β. Moreover, inhibiting PGI(2), either using PGIS siRNA and/or CAY10441 (EC(50) ∼20 nM), a PGI(2) receptor antagonist, increases NADPH-oxidase activation, mPGES-1 synthesis, and PGE(2) production. Finally, lower PGI(2) levels associated with higher PGIS tyrosine nitration, p47phox translocation to the membrane (an index of activation of NADPH-oxidase), and mPGES-1 expression and activity were detected in cardiovascular tissues of ApoE(-/-) mice exposed to cigarette smoke compared to control mice. In conclusion, cigarette smoke in association with cytokines alters the balance between PGI(2)/PGE(2), reducing PGI(2) production and increasing synthesis and activity of mPGES-1 via NADPH-oxidase activation, predisposing to development of pathological conditions.

P2X7 receptor and caspase 1 activation are central to airway inflammation observed after exposure to tobacco smoke

Chronic Obstructive Pulmonary Disease (COPD) is a cigarette smoke (CS)-driven inflammatory airway disease with an increasing global prevalence. Currently there is no effective medication to stop the relentless progression of this disease. It has recently been shown that an activator of the P2X7/inflammasome pathway, ATP, and the resultant products (IL-1β/IL-18) are increased in COPD patients. The aim of this study was to determine whether activation of the P2X7/caspase 1 pathway has a functional role in CS-induced airway inflammation. Mice were exposed to CS twice a day to induce COPD-like inflammation and the role of the P2X7 receptor was investigated. We have demonstrated that CS-induced neutrophilia in a pre-clinical model is temporally associated with markers of inflammasome activation, (increased caspase 1 activity and release of IL-1β/IL-18) in the lungs. A selective P2X7 receptor antagonist and mice genetically modified so that the P2X7 receptors were non-functional attenuated caspase 1 activation, IL-1β release and airway neutrophilia. Furthermore, we demonstrated that the role of this pathway was not restricted to early stages of disease development by showing increased caspase 1 activation in lungs from a more chronic exposure to CS and from patients with COPD. This translational data suggests the P2X7/Inflammasome pathway plays an ongoing role in disease pathogenesis. These results advocate the critical role of the P2X7/caspase 1 axis in CS-induced inflammation, highlighting this as a possible therapeutic target in combating COPD.

Interleukin-1beta induces increased transcriptional activation of the transforming growth factor-beta-activating integrin subunit beta8 through altering chromatin architecture

The integrin αvβ8 is a cell surface receptor for the latent domain (LAP) of the multifunctional cytokine TGF-β. Through its association with LAP, TGF-β is maintained in a latent form that must be activated to function. Binding to the integrin αvβ8 with subsequent metalloproteolytic cleavage of LAP represents a major mechanism of TGF-β activation in vivo. Altered expression of the integrin β8 subunit (ITGB8) is found in human chronic obstructive pulmonary disease, cancers, and brain vascular malformations. We have previously shown that the proinflammatory cytokine interleukin-1β (IL-1β) increases ITGB8 expression on lung fibroblasts, which increases αvβ8-mediated TGF-β activation in fibrosis and pathologic inflammation. Here we report the mechanism of increased ITGB8 expression by IL-1β. Our data support a model where the chromatin architecture of the ITGB8 core promoter is altered by nucleosomal repositioning that enhances the interaction of an AP1 complex (containing c-Jun and ATF2). This repositioning is caused by the dissociation of HDAC2 with the ITGB8 core promoter, leading to increased histone H4 acetylation and a loosening of nucleosomal-DNA interactions allowing "opening" of the chromatin structure and increased association of c-Jun and ATF-2. These changes are mediated through NFκB- and p38-dependent pathways. Ultimately, these events culminate in increasing ITGB8 transcription, αvβ8 surface expression, and αvβ8-mediated TGFβ activation.

Combinatorial effect of TIMP-1 and α1AT gene polymorphisms on development of chronic obstructive pulmonary disease

OBJECTIVE

To study the role of α(1)AT and TIMP-1 gene polymorphisms in development of COPD.

DESIGN AND METHODS

Blood samples from total 408 subjects (217 COPD patients and 191 controls) were used for genotyping and estimating biolevels of α(1)AT, TIMP-1 and inflammatory cytokines. Data was analyzed to determine the role of interaction of TIMP-1 and α(1)AT genes; and interplay between various genotypes and biolevels of α(1)AT, TIMP-1 and inflammatory cytokines in development of COPD.

RESULTS

Significantly low levels of α(1)AT and TIMP-1 were observed in COPD patients as compared to controls (P = 0.001), where as the inflammatory cytokines were found to be increased in patients. PIM3 allele of α(1)AT gene in COPD patients was found to be associated with low levels of α(1)AT (P = 0.001), the effect being more pronounced when PIM3 combined with rs6609533 of TIMP-1 gene (P = 0.0001). Combination of genotypes rs6609533 of TIMP-1 and PIM3 of α(1)AT containing the risk alleles was over-represented in patients (P = 0.005).

CONCLUSION

The SNP rs6609533 of TIMP-1 gene interacted with PIM3 of α(1)AT to make a possible risk combination for development of COPD.

Sputum and nasal lavage lung-specific biomarkers before and after smoking cessation

Background

Little is known about the effect of smoking cessation on airway inflammation. Secretory Leukocyte Protease Inhibitor (SLPI), Clara Cell protein 16 (CC16), elafin and human defensin beta-2 (HBD-2) protect human airways against inflammation and oxidative stress. In this longitudinal study we aimed to investigate changes in sputum and nasal lavage SLPI, CC16, elafin and HBD-2 levels in healthy smokers after 6 and 12 months of smoking cessation.

Methods

Induced sputum and nasal lavage was obtained from healthy current smokers (n = 76) before smoking cessation, after 6 months of smoking cessation (n = 29), after 1 year of smoking cessation (n = 22) and from 10 healthy never smokers. SLPI, CC16, elafin and HBD-2 levels were measured in sputum and nasal lavage supernatants by commercially available ELISA kits.

Results

Sputum SLPI and CC-16 levels were increased in healthy smokers before smoking cessation versus never-smokers (p = 0.005 and p = 0.08 respectively). SLPI and CC16 levels did not differ before and 6 months after smoking cessation (p = 0.118 and p = 0.543 respectively), neither before and 1 year after smoking cessation (p = 0.363 and p = 0.470 respectively). Nasal lavage SLPI was decreased 12 months after smoking cessation (p = 0.033). Nasal lavage elafin levels were increased in healthy smokers before smoking cessation versus never-smokers (p = 0.007), but there were no changes 6 months and 1 year after smoking cessation.

Conclusions

Only nasal lavage SLPI decrease after 1 year after smoking cessation. We may speculate that there is an ongoing inflammatory process stimulating the production of counter-regulating proteins in the airways of healthy ex-smokers.

The role of the NLRP3 inflammasome in the pathogenesis of airway disease

The incidences of respiratory diseases like asthma and Chronic Obstructive Pulmonary Disease (COPD) are increasing dramatically. Significantly, there are currently no treatments that can slow or prevent the relentless progression of COPD; and a sub-population of asthmatics are resistant to available therapies. What is more, currently prescribed medication has only minimal effect on the symptoms suffered in these patient groups. There is therefore an urgent need to develop effective drugs to treat these diseases. Whilst asthma and COPD are thought to be distinct diseases, it is currently believed that the pathogenesis of both is driven by the chronic inflammation present in the airways of these patients. It is thus hypothesised that if the inflammation could be attenuated, disease development would be slowed and symptoms reduced. It is therefore paramount to determine the pathways driving/propagating the inflammation. Recently there has been a growing body of evidence to suggest that the multimeric protein complex known as the Inflammasome may play key roles in the inflammation observed in respiratory diseases. The aim of this review is to discuss the role of the NLRP3 Inflammasome, and its associated inflammatory mediators (IL-1β and IL-18), in the pathogenesis of asthma and COPD.

Efficacy of two breath condensers

BACKGROUND

Examination of Exhaled Breath Condensate has been suggested to give information about inflammatory airway diseases.

OBJECTIVES

The aim was to compare efficacy and variability in gain of two commercially available exhaled breath condensers, ECoScreen and RTube in an in vitro set up.

METHODS

Test fluids containing myeloperoxidase (MPO) or human neutrophil lipocalin (HNL) in addition to saline and bovine serum albumin were nebulized and aerosols were transferred by a servo ventilator to either of the two condensers. Analyses of MPO, HNL, or chlorine were done by means of ELISA, RIA, or a modified adsorbed organic halogen technique (AOX), respectively.

RESULTS

Recoveries of HNL were higher when using ECoScreen than RTube (P<0.05). In contrast, there were no significant differences between the two condensers in recoveries of MPO or chlorine. The spread of data was wide regarding all tested compounds.

CONCLUSION

Variability in gain was large and ECoScreen was more efficacious then RTube in condensing the tested solutes of HNL, but not those of MPO or chlorine.

Persistent airway inflammation and emphysema progression on CT scan in ex-smokers observed for 4 years

BACKGROUND

Tobacco smoking is a principal cause of COPD-emphysema (COPD-E). Whether discontinuing smoking for at least 4 years halts airway inflammation and progression of COPD-E in prior smokers is unknown. In this study we investigated whether discontinuing smoking for approximately 4 years in ex-smokers with GOLD (Global Initiative for Chronic Lung Disease) stage IIb (moderately severe) COPD-E stopped airway inflammation (ie, sputum biomarkers) and halted the progression of COPD-E on chest CT scan.

METHODS

Ten ex-smokers with COPD-E who had quit smoking underwent chest CT scans to document the extent of COPD-E, assessment of lung function (FEV(1) and diffusing capacity of lung for carbon monoxide), sputum induction for biomarkers of inflammation (measured by enzyme-linked immunosorbent assay), and blood cotinine levels at baseline and approximately 4 years later. Normal healthy subjects (n = 7) and normal current smokers with no CT scan evidence of COPD-E (n = 8) served as sputum biomarker comparison groups.

RESULTS

After approximately 4 years of not smoking (documented by cotinine levels), ex-smokers with COPD-E had persistent increased levels of mediators of inflammation in sputum (myeloperoxidase, leukotriene B4, IL-8, monocyte chemoattractant protein-1, matrix metalloprotease-9), which was associated with significant progression of COPD-E on chest CT scan.

CONCLUSIONS

Cessation of tobacco smoking in heavy smokers with moderately severe COPD-E is associated with evidence of persistent airway inflammation and progression of COPD-E on CT scan 4 years later. Discontinuing smoking may slow the rate of progression of moderate severity COPD-E, but it does not prevent persistent airway inflammation and significant progression of COPD-E on CT scan.

Influence of interleukin-1 beta genetic polymorphism, smoking and alcohol drinking on the risk of non-small cell lung cancer

BACKGROUND

Non-small cell cancer (NSCLC) accounts for approximately 80% of all lung cancers. Reports suggested an association between the interleukin-1beta (IL-1beta) -31 and -511 gene loci and NSCLC, but few studies took into account the effect of smoking and/or alcohol drinking on the association.

METHODS

Two-hundred thirteen cases of NSCLC (aged 58.2 + or - 10.1) and 213 controls (aged 59.4 + or - 10.3y) were included in this research. Information about the smoking and drinking behaviors, dietary customs, and anamnesis were obtained from all subjects by questionnaires, and genomic DNA was extracted. IL-1beta -31 and -511 gene polymorphisms were detected using PCR-RFLP. The interactions between the genotypes and alcohol drinking/smoking were analyzed using multivariate logistic regression models.

RESULTS

(The T/T genotype and the T allele of the IL-1beta -31 gene were associated with higher incidence of NSCLC (P<0.05). For the IL-1beta -511 locus, no difference was found in different genotypes between the NSCLC and control groups. After the adjustment of confounding variables, such as age and gender, the binary logistic analysis showed a significant gene-environment interaction (P<0.05).

CONCLUSIONS

The IL-1beta -31T allele was positively associated with a risk of NSCLC, and the carriers of IL-1beta -31T/T or -511C/C would have a higher risk of suffering from NSCLC if they drank alcohol or smoke heavily.

The role of interleukin-1beta in murine cigarette smoke-induced emphysema and small airway remodeling

Interleukin-1beta (IL-1beta), a proinflammatory cytokine, is elevated in cigarette smokers. To determine whether IL-1beta plays a role in the pathogenesis of cigarette smoke-induced emphysema and small airway remodeling, IL-1 receptor knockout (IL1RKO), TNF-alpha receptor knockout (TNFRKO), or C57Bl/6 (control) mice were exposed to cigarette smoke acutely or for up to 6 months. With a single acute exposure, smoke elevated IL-1beta in C57Bl/6 mice. IL1RKO mice were protected against acute smoke-mediated increases in lavage inflammatory cells and matrix breakdown. In C57Bl/6 mice, acute smoke-mediated increases in inflammatory cells, serum IL-1beta, and serum TNF-alpha were blocked by z-VAD-fmk, a pan-caspase inhibitor, or z-WEHD-fmk, a caspase-1 (IL-1-converting enzyme, [ICE]) inhibitor. With 6 months of exposure, IL-1beta was no longer increased, but IL-18 was elevated. After 6 months of exposure, IL1RKO mice were 65% protected against emphysema, whereas TNFRKO mice were 83% protected. Both strains were completely protected against small airway remodeling. Lavage desmosine, hydroxyproline, and hyaluronan, matrix breakdown markers, were elevated in C57 but not IL1RKO mice. We conclude that IL-1beta plays a significant role in induction of murine emphysema and small airway remodeling, and is comparable to TNF-alpha in its effects. The protective effects of caspase inhibitors appear to be related to inhibition of ICE and raise the question of whether models that ameliorate emphysema with caspase inhibitors are really blocking IL-1beta (and IL-18) activation rather than blocking apoptosis.

Neutrophil migration induced by IL-1beta depends upon LTB4 released by macrophages and upon TNF-alpha and IL-1beta released by mast cells

In the present study, we investigate whether mast cells and macrophages are involved in the control of IL-1beta-induced neutrophil migration, as well as the participation of chemotactic mediators. IL-1beta induced a dose-dependent neutrophil migration to the peritoneal cavity of rats which depends on LTB(4), PAF and cytokines, since the animal treatment with inhibitors of these mediators (MK 886, PCA 4248 and dexamethasone respectively) inhibited IL-1beta-induced neutrophil migration. The neutrophil migration induced by IL-1beta is dependent on mast cells and macrophages, since depletion of mast cells reduced the process whereas the increase of macrophage population enhanced the migration. Moreover, mast cells or macrophages stimulated with IL-1beta released a neutrophil chemotactic factor, which mimicked the neutrophil migration induced by IL-1beta. The chemotactic activity of the supernatant of IL-1beta-stimulated macrophages is due to the presence of LTB(4), since MK 886 inhibited its release. Moreover, the chemotactic activity of IL-1beta-stimulated mast cells supernatant is due to the presence of IL-1beta and TNF-alpha, since antibodies against these cytokines inhibited its activity. Furthermore, significant amounts of these cytokines were detected in the supernatant. In conclusion, our results suggest that neutrophil migration induced by IL-1beta depends upon LTB(4) released by macrophages and upon IL-1beta and TNFalpha released by mast cells.

The influence of nicotine on granulocytic differentiation - inhibition of the oxidative burst and bacterial killing and increased matrix metalloproteinase-9 release

Background

Neutrophils leave the bone marrow as terminally differentiated cells, yet little is known of the influence of nicotine or other tobacco smoke components on neutrophil differentiation. Therefore, promyelocytic HL-60 cells were differentiated into neutrophils using dimethylsulfoxide in the presence and absence of nicotine (3-(1-methyl-2-pyrrolidinyl) pyridine). Differentiation was evaluated over 5 days by monitoring terminal differentiation markers (CD11b expression and formazan deposition); cell viability, growth phase, kinetics, and apoptosis; assessing cellular morphology and ultrastructure; and conformational changes to major cellular components. Key neutrophil effector functions (oxidative burst, bacterial killing, matrix metalloproteinase release) were also examined.

Results

Nicotine increased the percentage of cells in late differentiation phases (metamyelocytes, banded neutrophils and segmented neutrophils) compared to DMSO alone (p < 0.05), but did not affect any other marker of neutrophil differentiation examined. However, nicotine exposure during differentiation suppressed the oxidative burst in HL-60 cells (p < 0.001); inhibited bacterial killing (p < 0.01); and increased the LPS-induced release of MMP-9, but not MMP-2 (p < 0.05). These phenomena may be α-7-acetylcholine nicotinic receptor-dependent. Furthermore, smokers exhibited an increased MMP-9 burden compared to non-smokers in vivo (p < 0.05).

Conclusion

These findings may partially explain the known increase in susceptibility to bacterial infection and neutrophil-associated destructive inflammatory diseases in individuals chronically exposed to nicotine.

High prevalence of emphysema and its association with BMI: a study of smokers with normal spirometry

OBJECTIVES

To evaluate to what extent emphysema was evident, as identified by High Resolution Computed Tomography (HRCT), in smokers with normal lung function and to relate age, gender, smoking history, and body mass index (BMI) to the HRCT results. A secondary aim was to study to what extent emphysema was present in smokers with lower normal values of lung function defined as FEV(1)/FVC ratio percentage of predicted value (89-93% of predicted value for males and 90-93% for females) or FEF(50) < or = 60% of predicted compared with smokers without this definition.

METHODS

Fifty-nine smokers, with a mean age of 53 years and with normal lung function, were examined with HRCT.

RESULTS

Emphysema evidenced visually by HRCT was present in 43% of the subjects. Using a 0-5 grade scale (0=normal finding; 5=emphysema in most slices), the degree of emphysema was almost exclusively 3-4. The type of emphysema was distributed as centrilobular emphysema predominant in 43.5%, paraseptal emphysema predominant in 43.5%, and as an equal mixture of these types in 13%. The presence of emphysema did not differ between the group of smokers with lower normal values of lung function and the rest of the smokers. Smokers with emphysema had significantly lower BMI than those devoid of emphysema, 24 and 27 respectively (p<0.0011).

CONCLUSION

There was a high occurrence of visual emphysema in middle-aged smokers with normal lung function. The densitometric quantitative analysis method is inadequate for detecting mild emphysema. High prevalence of emphysema was associated with low BMI.

Clara cell 16 protein in COPD sputum: A marker of small airways damage?

RATIONALE

The development of chronic obstructive pulmonary disease (COPD) in smokers and their susceptibility to infections is not fully understood. Recent evidences suggest that Clara cells play a part in host defense, immunomodulatory response and airways remodelling through the production of specific factors such as Clara cell 16 (CC-16). This protein has never been related to patients' lung function tests, blood gases parameters and diseases severity.

OBJECTIVES

To evaluate a possible correlation between CC-16 expression in sputum, measured by a new methodological approach, and the degree of severity in patients with moderate and severe COPD. We also analyzed possible correlations between CC-16 and cytological sputum population, arterial blood gases and lung function.

MAIN FINDINGS

We analyzed 20 patients, mean age 72.95, classified on the basis of the global initiative for chronic obstructive lung disease guidelines (GOLD 2006). The samples were processed for cytological analysis and CC-16 levels were assessed by Western blot. We found lower levels of CC-16 in severe COPD compared to moderate ones (p<0.027). No statistically significant differences were found between CC-16 expression and sputum cellularity (except for macrophages), arterial blood gases, and spirometric parameters. Multiple linear regression analysis of CC-16 versus functional and cytological parameters showed no significance.

CONCLUSIONS

We found a significantly different expression of CC-16 in COPD patients, according to their stage of severity, as defined by the GOLD 2006 guidelines. Considering CC-16 properties in innate immunity, a possible link between protein expression, innate immune system, and COPD infectious exacerbations may be hypothesized but further investigation are needed.

Decreased expression of antioxidant enzymes and increased expression of chemokines in COPD lung

The involvement of inflammation in the pathogenesis of chronic obstructive pulmonary disease (COPD) has been investigated using samples from relatively central airways such as airway biopsies, but there have been fewer studies in the peripheral lung, which is thought to be the main site of the disease process. To determine the molecules that relate to the mechanisms underlying the pathogenesis of COPD, we evaluated the mRNA expression of inflammatory cytokines, chemokines, oxidant enzymes, antioxidant enzymes, proteinases and antiproteinases in peripheral lung tissues from 33 COPD and non-COPD subjects who were undergoing lung resection for lung cancer using an RT-PCR technique. Among the 42 studied candidate genes, the expressions of mRNA for catalase, glutathion S-transferase P1 (GSTP1), glutathion S-transferase M1 (GSTM1), microsomal epoxide hydrolase (mEPHX) and tissue inhibitor of metalloproteinase 2 (TIMP2) were significantly decreased in COPD lung tissues compared with those in non-COPD tissues, and most of these decreases were significantly correlated with the degree of airflow limitation. On the other hand, the expressions of mRNA for interleukin 1beta (IL-1beta), interleukin 8 (IL-8), growth-related oncogene-alpha (Gro-alpha) and monocyte chemotactic protein-1 (MCP-1) were significantly increased in COPD lungs. Most of these changes were also associated with cigarette smoking. These data suggest that an impairment of protective mechanisms against oxidants and xenobiotics, in addition to the upregulation of CXC- and CC-chemokines, may be associated with cigarette smoking and involved in the inflammatory process of COPD.