Biopsy neutrophilia, neutrophil chemokine and receptor gene expression in severe exacerbations of chronic obstructive pulmonary disease

Disruption of the structural and functional features of surfactant protein A by acrolein in cigarette smoke

The extent to which defective innate immune responses contribute to chronic obstructive pulmonary disease (COPD) is not fully understood. Pulmonary surfactant protein A (SP-A) plays an important role in regulating innate immunity in the lungs. In this study, we hypothesised that cigarette smoke (CS) and its component acrolein might influence pulmonary innate immunity by affecting the function of SP-A. Indeed, acrolein-modified SP-A was detected in the lungs of mice exposed to CS for 1 week. To further confirm this finding, recombinant human SP-A (hSP-A) was incubated with CS extract (CSE) or acrolein and then analysed by western blotting and nanoscale liquid chromatography-matrix-assisted laser desorption/ionisation time-of-flight tandem mass spectrometry. These analyses revealed that CSE and acrolein induced hSP-A oligomerisation and that acrolein induced the modification of six residues in hSP-A: His39, His116, Cys155, Lys180, Lys221, and Cys224. These modifications had significant effects on the innate immune functions of hSP-A. CSE- or acrolein-induced modification of hSP-A significantly decreased hSP-A's ability to inhibit bacterial growth and to enhance macrophage phagocytosis. These findings suggest that CS-induced structural and functional defects in SP-A contribute to the dysfunctional innate immune responses observed in the lung during cigarette smoking.

Role of Proteases in Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is generally associated with progressive destruction of airways and lung parenchyma. Various factors play an important role in the development and progression of COPD, like imbalance of proteases, environmental and genetic factors and oxidative stress. This review is specifically focused on the role of proteases and their imbalance in COPD. There are three classes (serine, mettalo, and cysteine) of proteases involved in COPD. In serine proteases, neutrophil elastase, cathepsin G, and proteinase-3 are involved in destruction of alveolar tissue. Matrix-mettaloproteinase-9, 12, 13, plays an influential role in severity of COPD. Among cysteine proteases, caspase-3, caspases-8 and caspase-9 play an important role in controlling apoptosis. These proteases activities can be regulated by inhibitors like α-1-antitrypsin, neutrophil elastase inhibitor, and leukocyte protease inhibitor. Studies suggest that neutrophil elastase may be a therapeutic target for COPD, and specific inhibitor against this enzyme has potential role to control the disease. Current study suggests that Dipeptidyl Peptidase IV is a potential marker for COPD. Since the expression of proteases and its inhibitors play an important role in COPD pathogenesis, therefore, it is worth investigating the role of proteases and their regulation. Understanding the biochemical basis of COPD pathogenesis using advanced tools in protease biochemistry and aiming toward translational research from bench-to-bedside will have great impact to deal with this health problem.

Danirixin: A Reversible and Selective Antagonist of the CXC Chemokine Receptor 2

CXC chemokine receptor 2 (CXCR2) is a key receptor in the chemotaxis of neutrophils to sites of inflammation. The studies reported here describe the pharmacological characterization of danirixin, a CXCR2 antagonist in the diaryl urea chemical class. Danirixin has high affinity for CXCR2, with a negative log of the 50% inhibitory concentration (pIC50) of 7.9 for binding to Chinese hamster ovary cell (CHO)-expressed human CXCR2, and 78-fold selectivity over binding to CHO-expressed CXCR1. Danirixin is a competitive antagonist against CXCL8 in Ca2+-mobilization assays, with a KB (the concentration of antagonist that binds 50% of the receptor population) of 6.5 nM and antagonist potency (pA2) of 8.44, and is fully reversible in washout experiments over 180 minutes. In rat and human whole-blood studies assessing neutrophil activation by surface CD11b expression following CXCL2 (rat) or CXCL1 (human) challenge, danirixin blocks the CD11b upregulation with pIC50s of 6.05 and 6.3, respectively. Danirixin dosed orally also blocked the influx of neutrophils into the lung in vivo in rats following aerosol lipopolysaccharide or ozone challenge, with median effective doses (ED50s) of 1.4 and 16 mg/kg respectively. Thus, danirixin would be expected to block chemotaxis in disease states in which neutrophils are increased in response to inflammation, such as pulmonary diseases. In comparison with navarixin, a CXCR2 antagonist from a different chemical class, the binding characterization of danirixin is distinct. These observations may offer insight into the previously observed clinical differences in induction of neutropenia between these compounds.

The Role and Immunobiology of Eosinophils in the Respiratory System: a Comprehensive Review

The eosinophil is a fully delineated granulocyte that disseminates throughout the bloodstream to end-organs after complete maturation in the bone marrow. While the presence of eosinophils is not uncommon even in healthy individuals, these granulocytes play a central role in inflammation and allergic processes. Normally appearing in smaller numbers, higher levels of eosinophils in the peripheral blood or certain tissues typically signal a pathologic process. Eosinophils confer a beneficial effect on the host by enhancing immunity against molds and viruses. However, tissue-specific elevation of eosinophils, particularly in the respiratory system, can cause a variety of short-term symptoms and may lead to long-term sequelae. Eosinophils often play a role in more commonly encountered disease processes, such as asthma and allergic responses in the upper respiratory tract. They are also integral in the pathology of less common diseases including eosinophilic pneumonia, allergic bronchopulmonary aspergillosis, hypersensitivity pneumonitis, and drug reaction with eosinophilia and systemic symptoms. They can be seen in neoplastic disorders or occupational exposures as well. The involvement of eosinophils in pulmonary disease processes can affect the method of diagnosis and the selection of treatment modalities. By analyzing the complex interaction between the eosinophil and its environment, which includes signaling molecules and tissues, different therapies have been discovered and created in order to target disease processes at a cellular level. Innovative treatments such as mepolizumab and benralizumab will be discussed. The purpose of this article is to further explore the topic of eosinophilic presence, activity, and pathology in the respiratory tract, as well as discuss current and future treatment options through a detailed literature review.

Clinical Association of Chemokine (C-X-C motif) Ligand 1 (CXCL1) with Interstitial Pneumonia with Autoimmune Features (IPAF)

The term “interstitial pneumonia with autoimmune features” (IPAF) has been recently proposed. We here investigate the clinical characteristics of IPAF and evaluate the clinical implications of CXCL1-CXCR2 axis in IPAF. An increased plasma level of CXCL1 was exhibited in IPAF compared to idiopathic interstitial pneumonia (IIP), chronic obstructive pulmonary disease (COPD), and healthy controls. Additionally, plasma CXCL1 levels were clinically associated with diffusing capacity of the lungs for carbon monoxide (DLCO), erythrocyte sedimentation rate (ESR), and involved parenchyma extension in IPAF. Furthermore, circulating CXCL1 levels were highest in IPAF patients with acute exacerbations. CXCR2, the chemokine receptor for CXCL1, was readily observed in inflammatory aggregates and endothelial cells in IPAF lungs, but was lower in IIP lungs and healthy lungs. Interestingly, increased CXCL1 concentrations in BALF paralleled neutrophil counts in IPAF. Overall, the plasma concentrations of CXCL1 indicated the disease activity and prognosis in IPAF. Thus, the CXCL1/CXCR2 axis appears to be involved in the progression of IPAF.

Validation of antibody reagents for mucin analysis in chronic inflammatory airway diseases

In chronic inflammatory airway diseases, mucins display disease-related alterations in quantity, composition and glycosylation. This opens the possibility to diagnose and monitor inflammatory airway disorders and their exacerbation based on mucin properties. For such an approach to be reasonably versatile and diagnostically meaningful, the mucin of interest must be captured in a reliable, patient-independent way. To identify appropriate mucin-specific reagents, we tested anti-mucin antibodies on mucin-content-standardized, human bronchoalveolar lavage fluid samples in immunoblot assays. All commercially available monoclonal antibodies against the major airway mucin MUC5AC were screened, except for those with known specificity for carbohydrates, as glycosylation patterns are not mucin-specific. Our results indicated considerable inter-patient and inter-antibody variability in mucin recognition for all antibodies and samples tested. The best results in terms of signal strength and reproducibility were obtained with antibodies Mg-31, O.N.457 and 45M1. Additional epitope mapping experiments revealed that only one of the antibodies with superior binding to MUC5AC recognized linear peptide epitopes on the protein backbone.

Identification of novel macrolides with antibacterial, anti-inflammatory and type I and III IFN-augmenting activity in airway epithelium

BACKGROUND

Exacerbations of asthma and COPD are triggered by rhinoviruses. Uncontrolled inflammatory pathways, pathogenic bacterial burden and impaired antiviral immunity are thought to be important factors in disease severity and duration. Macrolides including azithromycin are often used to treat the above diseases, but exhibit variable levels of efficacy. Inhaled corticosteroids are also readily used in treatment, but may lack specificity. Ideally, new treatment alternatives should suppress unwanted inflammation, but spare beneficial antiviral immunity.

METHODS

In the present study, we screened 225 novel macrolides and tested them for enhanced antiviral activity against rhinovirus, as well as anti-inflammatory activity and activity against Gram-positive and Gram-negative bacteria. Primary bronchial epithelial cells were grown from 10 asthmatic individuals and the effects of macrolides on rhinovirus replication were also examined. Another 30 structurally similar macrolides were also examined.

RESULTS

The oleandomycin derivative Mac5, compared with azithromycin, showed superior induction (up to 5-fold, EC50 = 5-11 μM) of rhinovirus-induced type I IFNβ, type III IFNλ1 and type III IFNλ2/3 mRNA and the IFN-stimulated genes viperin and MxA, yet had no effect on IL-6 and IL-8 mRNA. Mac5 also suppressed rhinovirus replication at 48 h, proving antiviral activity. Mac5 showed antibacterial activity against Gram-positive Streptococcus pneumoniae; however, it did not have any antibacterial properties compared with azithromycin when used against Gram-negative Escherichia coli (as a model organism) and also the respiratory pathogens Pseudomonas aeruginosa and non-typeable Haemophilus influenzae. Further non-toxic Mac5 derivatives were identified with various anti-inflammatory, antiviral and antibacterial activities.

CONCLUSIONS

The data support the idea that macrolides have antiviral properties through a mechanism that is yet to be ascertained. We also provide evidence that macrolides can be developed with anti-inflammatory, antibacterial and antiviral activity and show surprising versatility depending on the clinical need.

Pathogenesis of Viral Infection in Exacerbations of Airway Disease

Chronic airway diseases are a significant cause of morbidity and mortality worldwide, and their prevalence is predicted to increase in the future. Respiratory viruses are the most common cause of acute pulmonary infection, and there is clear evidence of their role in acute exacerbations of inflammatory airway diseases such as asthma and chronic obstructive pulmonary disease. Studies have reported impaired host responses to virus infection in these diseases, and a better understanding of the mechanisms of these abnormal immune responses has the potential to lead to the development of novel therapeutic targets for virus-induced exacerbations. The aim of this article is to review the current knowledge regarding the role of viruses and immune modulation in acute exacerbations of chronic pulmonary diseases and to discuss exciting areas for future research and novel treatments.

Neutrophil Extracellular Traps in Pulmonary Diseases: Too Much of a Good Thing?

Neutrophil extracellular traps (NETs) arise from the release of granular and nuclear contents of neutrophils in the extracellular space in response to different classes of microorganisms, soluble factors, and host molecules. NETs are composed by decondensed chromatin fibers coated with antimicrobial granular and cytoplasmic proteins, such as myeloperoxidase, neutrophil elastase (NE), and α-defensins. Besides being expressed on NET fibers, NE and MPO also regulate NET formation. Furthermore, histone deimination by peptidylarginine deiminase 4 (PAD4) is a central step to NET formation. NET formation has been widely demonstrated to be an effective mechanism to fight against invading microorganisms, as deficiency in NET release or dismantling NET backbone by bacterial DNases renders the host susceptible to infections. Therefore, the primary role of NETs is to prevent microbial dissemination, avoiding overwhelming infections. However, an excess of NET formation has a dark side. The pathogenic role of NETs has been described for many human diseases, infectious and non-infectious. The detrimental effect of excessive NET release is particularly important to lung diseases, because NETs can expand more easily in the pulmonary alveoli, causing lung injury. Moreover, NETs and its associated molecules are able to directly induce epithelial and endothelial cell death. In this regard, massive NET formation has been reported in several pulmonary diseases, including asthma, chronic obstructive pulmonary disease, cystic fibrosis, respiratory syncytial virus bronchiolitis, influenza, bacterial pneumonia, and tuberculosis, among others. Thus, NET formation must be tightly regulated in order to avoid NET-mediated tissue damage. Recent development of therapies targeting NETs in pulmonary diseases includes DNA disintegration with recombinant human DNase, neutralization of NET proteins, with anti-histone antibodies and protease inhibitors. In this review, we summarize the recent knowledge on the pathophysiological role of NETs in pulmonary diseases as well as some experimental and clinical approaches to modulate their detrimental effects.

Linking e-health records, patient-reported symptoms and environmental exposure data to characterise and model COPD exacerbations: protocol for the COPE study

INTRODUCTION

Relationships between exacerbations of chronic obstructive pulmonary disease (COPD) and environmental factors such as temperature, humidity and air pollution are not well characterised, due in part to oversimplification in the assignment of exposure estimates to individuals and populations. New developments in miniature environmental sensors mean that patients can now carry a personal air quality monitor for long periods of time as they go about their daily lives. This creates the potential for capturing a direct link between individual activities, environmental exposures and the health of patients with COPD. Direct associations then have the potential to be scaled up to population levels and tested using advanced human exposure models linked to electronic health records.

METHODS AND ANALYSIS

This study has 5 stages: (1) development and deployment of personal air monitors; (2) recruitment and monitoring of a cohort of 160 patients with COPD for up to 6 months with recruitment of participants through the Clinical Practice Research Datalink (CPRD); (3) statistical associations between personal exposure with COPD-related health outcomes; (4) validation of a time-activity exposure model and (5) development of a COPD prediction model for London.

ETHICS AND DISSEMINATION

The Research Ethics Committee for Camden and Islington has provided ethical approval for the conduct of the study. Approval has also been granted by National Health Service (NHS) Research and Development and the Independent Scientific Advisory Committee. The results of the study will be disseminated through appropriate conference presentations and peer-reviewed journals.

COPD immunopathology

The immunopathology of chronic obstructive pulmonary disease (COPD) is based on the innate and adaptive inflammatory immune responses to the chronic inhalation of cigarette smoking. In the last quarter of the century, the analysis of specimens obtained from the lower airways of COPD patients compared with those from a control group of age-matched smokers with normal lung function has provided novel insights on the potential pathogenetic role of the different cells of the innate and acquired immune responses and their pro/anti-inflammatory mediators and intracellular signalling pathways, contributing to a better knowledge of the immunopathology of COPD both during its stable phase and during its exacerbations. This also has provided a scientific rationale for new drugs discovery and targeting to the lower airways. This review summarises and discusses the immunopathology of COPD patients, of different severity, compared with control smokers with normal lung function.

Convergence in the Epidemiology and Pathogenesis of COPD and Pneumonia

Chronic obstructive pulmonary disease (COPD) is one of the main causes of human mortalities globally after heart disease and stroke. There is increasing evidence of an aetiological association between COPD and pneumonia, the leading infectious cause of death globally in children under 5 years. In this review, we discuss the known risk factors of COPD that are also shared with pneumonia including smoking, air pollution, age and immune suppression. We review how lung pathology linked to a previous history of pneumonia may heighten susceptibility to the development of COPD in later life. Furthermore, we examine how specific aspects of COPD immunology could contribute to the manifestation of pneumonia. Based on the available evidence, a convergent relationship is becoming apparent with respect to the pathogenesis of COPD and pneumonia. This has implications for the management of both diseases, and the development of new interventions.

The role of viral infections in exacerbations of chronic obstructive pulmonary disease and asthma

Asthma and chronic obstructive pulmonary disease (COPD) are major causes of global morbidity and mortality worldwide. The clinical course of both asthma and COPD are punctuated by the occurrence of exacerbations, acute events characterized by increased symptoms and airflow obstruction. Exacerbations contribute most of the morbidity, mortality and excess healthcare costs associated with both asthma and COPD. COPD and asthma exacerbations are frequently associated with respiratory virus infections and this has led to an intense research focus into the mechanisms of virus-induced exacerbations over the past decade. Current therapies are effective in reducing chronic symptoms but are less effective in preventing exacerbations, particularly in COPD. Understanding the mechanisms of virus-induced exacerbation will lead to the development of new targeted therapies that can reduce the burden of virus-induced exacerbations. In this review we discuss current knowledge of virus-induced exacerbations of asthma and COPD with a particular focus on mechanisms, human studies, virus-bacteria interactions and therapeutic advances.

Tumor necrosis factor-α driven inflammation in alpha-1 antitrypsin deficiency: a new model of pathogenesis and treatment

Alpha-1 antitrypsin (AAT) deficiency (AATD) has traditionally been thought of as a genetic disorder characterized by lung destruction and early emphysema in a low AAT, and high neutrophil elastase (NE) environment in the lungs of affected individuals. Recently, a growing body of evidence has emerged to support the hypothesis that tumor necrosis factor alpha (TNF-α) is essential in the pathogenesis of both genetic AATD and non-genetic chronic obstructive pulmonary disease (COPD). Reports have highlighted the importance of TNF-α driven immune cell dysfunction in the development of lung disease in AATD. The authors discuss the role of AAT as a key modulator of TNF-α signaling firstly in the setting of AATD and secondly in other conditions where AAT augmentation therapy has potential utility as a novel therapy.

Haemophilus influenzae induces steroid-resistant inflammatory responses in COPD

Background

Chronic obstructive pulmonary disease (COPD) is an inflammatory disorder partially resistant to glucocorticoids. A reduced histone deacetylase (HDAC) activity has been proposed to explain this resistance. Haemophilus influenzae frequently colonizes the airways of COPD patients, where it enhances inflammation. The effects of Haemophilus influenzae on HDAC activity have not been investigated before.

Methods

The effects of the presence or absence of Haemophilus influenzae ex-vivo and in vitro were studied. To this end, we determined: (1) cytokine release in alveolar macrophages (AM) from 7 patients with COPD, 5 healthy smokers, 6 healthy non-smokers and (2) HDAC activity, nuclear factor kappa B (NF-κB) activation in a macrophage-like cell line (PMA-transformed U937 cells) co-cultured with epithelial cells. Experiments were repeated with dexamethasone (1 μM) and/or the HDAC enhancer theophylline (10 μM).

Results

Haemophilus influenzae induced a steroid-resistant inflammatory response in AM from COPD and controls and decreased HDAC activity, activated NF-κB and induced the secretion of several cytokines (IL-6, IL-8, IL-1β, IL-10 and TNF-α) (p < 0.001 for all comparisons) in the macrophage-like cell line. Dexamethasone reduced NF-κB activation but it did not modify HDAC activity. The addition of theophylline to dexamethasone increased HDAC activity and suppressed cytokine release completely, without modifying NF-κB activation.

Conclusions

These results indicate that Haemophilus influenzae reduces HDAC activity and induces a NF-κB mediated inflammatory response that is only partially suppressed by glucocorticoids irrespective of having COPD. Yet, the latter can be fully restored by targeting HDAC activity.

Electronic supplementary material

The online version of this article (doi:10.1186/s12890-015-0155-3) contains supplementary material, which is available to authorized users.

CXCL5 is a potential diagnostic and prognostic marker for bladder cancer patients

Chemokine C-X-C motif ligand 5 (CXCL5) is critical for bladder cancer growth and progression. Our previous study demonstrated that increase of CXCL5 in bladder cancer cell lines had an effect on tumor growth and progression. This study aims to investigate the expression of CXCL5 in tissue and urine of bladder cancer patients, in relation to clinicopathologic parameters, and as a predictive value in diagnosing and evaluating bladder cancer. Urothelial bladder cancer tissues from 255 patients were profiled for CXCL5 alterations by immunohistochemistry. Urine samples collected from patients with bladder cancer and urinary tract infections as well as healthy volunteers were analyzed by ELISA. High expression of CXCL5 in bladder cancer tissue was correlated with TNM stage (P = 0.012), cancer grade (P = 0.001), and lymph node metastasis (P = 0.007). CXCL5 alterations were associated with overall survival (P = 0.007), progression free survival (P = 0.004), and recurrence free survival in muscle invasive bladder cancers (P = 0.026). CXCL5 expression in the urine of bladder cancer patients was significantly different from urinary tract infection patients (P = 0.001) and healthy volunteers. However, urine leukocytes may predict CXCL5 levels (β = 0.56, P < 0.001, R (2) = 0.314). CXCL5 expression in urine was also related to bladder cancer TNM stage (P = 0.039), lymph node metastasis (P = 0.023), tumor size (P = 0.007), and tumor grade (P = 0.005). The sensitivity and specificity for CXCL5/creatinine in predicting bladder cancer were 80.4 and 61.3 %, respectively. These results suggest increased CXCL5 expression in cancer tissue predicts poor survival in bladder cancer patients. CXCL5 expression in urine is useful in a minimally invasive modality for bladder cancer diagnosis. However, urine leukocytes are significant predictors of CXCL5 levels and may affect its result in bladder cancer diagnosis.

Interleukin-17A and Toll-Like Receptor 3 Ligand Poly(I:C) Synergistically Induced Neutrophil Chemoattractant Production by Bronchial Epithelial Cells

Chronic inflammatory airway diseases, such as bronchial asthma and chronic obstructive pulmonary disease, are common respiratory disorders worldwide. Exacerbations of these diseases are frequent and worsen patients’ respiratory condition and overall health. However, the mechanisms of exacerbation have not been fully elucidated. Recently, it was reported that interleukin (IL)-17A might play an important role in neutrophilic inflammation, which is characteristic of such exacerbations, through increased production of neutrophil chemoattractants. Therefore, we hypothesized that IL-17A was involved in the pathogenesis of acute exacerbation, due to viral infection in chronic inflammatory airway diseases. In this study, we assessed chemokine production by bronchial epithelial cells and investigated the underlying mechanisms. Comprehensive chemokine analysis showed that, compared with poly(I:C) alone, co-stimulation of BEAS-2B cells with IL-17A and poly(I:C) strongly induced production of such neutrophil chemoattractants as CXC chemokine ligand (CXCL)8, growth-related oncogene (GRO), and CXCL1. Co-stimulation synergistically induced CXCL8 and CXCL1 mRNA and protein production by BEAS-2B cells and normal human bronchial epithelial cells. Poly(I:C) induced chemokine expression by BEAS-2B cells mainly via Toll-like receptor 3/TIR-domain-containing adapter-inducing interferon-β–mediated signals. The co-stimulation with IL-17A and poly(I:C) markedly activated the p38 and extracellular-signal-regulated kinase 1/2 pathway, compared with poly(I:C), although there was little change in nuclear factor-κB translocation into the nucleus or the transcriptional activities of nuclear factor-κB and activator protein 1. IL-17A promoted stabilization of CXCL8 mRNA in BEAS-2B cells treated with poly(I:C). In conclusion, IL-17A appears to be involved in the pathogenesis of chronic inflammatory airway disease exacerbation, due to viral infection by promoting release of neutrophil chemoattractants from bronchial epithelial cells.

The Effect of Statins on Blood Gene Expression in COPD

BACKGROUND

COPD is currently the fourth leading cause of death worldwide. Statins are lipid lowering agents with documented cardiovascular benefits. Observational studies have shown that statins may have a beneficial role in COPD. The impact of statins on blood gene expression from COPD patients is largely unknown.

OBJECTIVE

Identify blood gene signature associated with statin use in COPD patients, and the pathways underpinning this signature that could explain any potential benefits in COPD.

METHODS

Whole blood gene expression was measured on 168 statin users and 451 non-users from the ECLIPSE study using the Affymetrix Human Gene 1.1 ST microarray chips. Factor Analysis for Robust Microarray Summarization (FARMS) was used to process the expression data. Differential gene expression analysis was undertaken using the Linear Models for Microarray data (Limma) package adjusting for propensity score and surrogate variables. Similarity of the expression signal with published gene expression profiles was performed in ProfileChaser.

RESULTS

25 genes were differentially expressed between statin users and non-users at an FDR of 10%, including LDLR, CXCR2, SC4MOL, FAM108A1, IFI35, FRYL, ABCG1, MYLIP, and DHCR24. The 25 genes were significantly enriched in cholesterol homeostasis and metabolism pathways. The resulting gene signature showed correlation with Huntington's disease, Parkinson's disease and acute myeloid leukemia gene signatures.

CONCLUSION

The blood gene signature of statins' use in COPD patients was enriched in cholesterol homeostasis pathways. Further studies are needed to delineate the role of these pathways in lung biology.

The effect of a selective CXCR2 antagonist (AZD5069) on human blood neutrophil count and innate immune functions

AIMS

The aim of the present study was to investigate whether selective antagonism of the cysteine-X-cysteine chemokine receptor-2 (CXCR2) receptor has any adverse effects on the key innate effector functions of human neutrophils for defence against microbial pathogens.

METHODS

In a double-blind, crossover study, 30 healthy volunteers were randomized to treatment with the CXCR2 antagonist AZD5069 (100 mg) or placebo, twice daily orally for 6 days. The peripheral blood neutrophil count was assessed at baseline, daily during treatment and in response to exercise challenge and subcutaneous injection of granulocyte-colony stimulating factor (G-CSF). Neutrophil function was evaluated by phagocytosis of Escherichia coli and by the oxidative burst response to E. coli.

RESULTS

AZD5069 treatment reversibly reduced circulating neutrophil count from baseline by a mean [standard deviation (SD)] of -1.67 (0.67) ×10(9) l(-1) vs. 0.19 (0.78) ×10(9) l(-1) for placebo on day 2, returning to baseline by day 7 after the last dose. Despite low counts on day 4, a 10-min exercise challenge increased absolute blood neutrophil count, but the effect with AZD5069 was smaller and not sustained, compared with placebo treatment. Subcutaneous G-CSF on day 5 caused a substantial increase in blood neutrophil count in both placebo- and AZD5069-treated subjects. Superoxide anion production in E. coli-stimulated neutrophils and phagocytosis of E. coli were unaffected by AZD5069 (P = 0.375, P = 0.721, respectively vs. baseline, Day 4). AZD5069 was well tolerated.

CONCLUSIONS

CXCR2 antagonism did not appear adversely to affect the mobilization of neutrophils from bone marrow into the peripheral circulation, phagocytosis or the oxidative burst response to bacterial pathogens. This supports the potential of CXCR2 antagonists as a treatment option for diseases in which neutrophils play a pathological role.

The CXCR1/2 Pathway: Involvement in Diabetes Pathophysiology and Potential Target for T1D Interventions

Although numerous chemokine/chemokine receptor pathways have been described to be implicated in the pathogenesis of type 1 diabetes (T1D), the CXCR1/2 axis has recently been proved to be crucial for leucocyte recruitment involved in insulitis and β cell damage. Multiple strategies blocking the CXCR1/2 pathway are available such as neutralizing antibodies, small molecules and peptide-derived inhibitors. They were firstly and widely used in cancer thanks to their anti-tumorigenic activity and only recently they were tested as a new interventional approach for T1D. As well, CXCR1/2 inhibition has been demonstrated to prevent inflammation- and autoimmunity-mediated damage of the pancreatic islets through inhibiting the migration of CXCR1/2-expressing cells. Among them, neutrophils, macrophages, and, although to a smaller extent, lymphoid cells are the main CXCR1/2-expressing cells. These results supported the active role of the innate immunity in the autoimmune process and opened new interventional approaches for the management of T1D.

Biomarkers for precision medicine in airways disease

Chronic obstructive pulmonary disease (COPD) is a complex clinical entity. In contrast to previously limited diagnostic definitions, it is now apparent that COPD is a clinically and biologically heterogeneous disease process, overlapping with other airways diseases like chronic asthma. As such, symptomatic response to current standard treatment practices is variable. New clinical guidelines have been altered to reflect this, with the inclusion of symptoms and risk factors in diagnostic and management algorithms. However, as our understanding of COPD pathophysiology deepens, many novel physiological, cellular, proteomic, and genetic markers have been identified. Several have been observed to be independently predictive of distinct clinical disease patterns, which at present are not illustrated by conventional measurements of lung impairment. The potential use of these predictive biomarkers to stratify this diverse patient population could transform the care we offer. We should aim for precision medicine to optimize diagnosis and treatment choices and to monitor and improve clinical outcomes in this disease.

Phage display and hybridoma generation of antibodies to human CXCR2 yields antibodies with distinct mechanisms and epitopes

Generation of functional antibodies against integral membrane proteins such as the G-protein coupled receptor CXCR2 is technically challenging for several reasons, including limited epitope accessibility, the requirement for a lipid environment to maintain structure and their existence in dynamic conformational states. Antibodies to human CXCR2 were generated by immunization in vivo and by in vitro selection methods. Whole cell immunization of transgenic mice and screening of phage display libraries using CXCR2 magnetic proteoliposomes resulted in the isolation of antibodies with distinct modes of action. The hybridoma-derived antibody fully inhibited IL-8 and Gro-α responses in calcium flux and β-arrestin recruitment assays. The phage-display derived antibodies were allosteric antagonists that showed ligand dependent differences in functional assays. The hybridoma and phage display antibodies did not cross-compete in epitope competition assays and mapping using linear and CLIPS peptides confirmed that they recognized distinct epitopes of human CXCR2. This illustrates the benefits of using parallel antibody isolation approaches with different antigen presentation methods to successfully generate functionally and mechanistically diverse antagonistic antibodies to human CXCR2. The method is likely to be broadly applicable to other complex membrane proteins.

Correlation between decrease of CRP and resolution of airway inflammatory response, improvement of health status, and clinical outcomes during severe acute exacerbation of chronic obstructive pulmonary disease

Circulating C-reactive protein (CRP) plays an important role in mediating extra-pulmonary complications of chronic obstructive pulmonary disease (COPD). The aim of this study was to investigate the relationship between changes in high sensitivity (hs)-CRP levels and the resolution of airway inflammatory markers and clinical health status during the recovery period after an acute exacerbation of COPD (AECOPD). Consecutive patients hospitalized for AECOPD were recruited. Serum hs-CRP, airway inflammatory markers, and COPD Assessment Test (CAT) score were evaluated at admission prior to treatment and at days 4, 7, and 14. Adverse outcomes were recorded. The relationship between changes in airway inflammatory markers, CAT score, and hs-CRP during the recovery period was studied. A total of 135 patients were enrolled. Serum hs-CRP levels at admission of patients with adverse outcomes were marginally higher than those without an adverse outcome (7.6 [4.8, 16.7] vs. 6.6 [4.7, 9.3], p = 0.061). Compared with patients without cardiovascular complications, patients with cardiovascular complications had higher serum hs-CRP levels at admission (11.6 [6.7, 16.7] vs. 6.6 [4.4, 10.0], p = 0.001). Sputum neutrophils were positively correlated to hs-CRP at admission (r = 0.474, p < 0.001). A decreasing hs-CRP level was positively related to decreasing sputum neutrophils at day 4 and 7 (r = 0.455, p < 0.001; r = 0.504, p < 0.001, respectively). Significant correlations between decreasing hs-CRP and CAT at all time-points were noted. Hs-CRP may be useful in monitoring airway inflammation resolution and improvement of health status during AECOPD treatment.

Impaired CXCR1-dependent oxidative defence in active tuberculosis patients

Much of the pronounced host inflammatory response that occurs in tuberculosis (TB) is related to failed immunity against the invading pathogen. The G-protein coupled receptors CXCR1 and CXCR2 are implicated in important signal transduction pathways in lung inflammatory responses. We investigated the expression and function of these receptors in a simple whole blood model from 24 patients with pulmonary TB and in subjects with latent TB infection (LTBI). Healthy controls were recruited from close contacts to the pulmonary index patients. We found that pulmonary TB patients had significantly increased CXCR1 expression on blood cells compared to LTBI subjects and controls (p < 0.001). In contrast, LTBI subjects had a significant increase in CXCR2 expression compared to pulmonary TB patients (p < 0.001) and controls (p < 0.01). Leukocyte function, measured as oxidative capacity, was decreased in pulmonary TB patients compared to LTBI and controls (p < 0.001) and correlated with the increased CXCR1 expression. Leukocyte recruitment, measured as the expression of microRNA-223 was increased in pulmonary TB patients compared to LTBI (p < 0.05). We found that variations in receptor expression are linked to disease progression and affect the immune response against Mycobacterium tuberculosis (Mtb).

The effects of the CXCR2 antagonist, MK-7123, on bone marrow functions in healthy subjects

The CXCR2 antagonist MK-7123 causes dose-dependent reductions in absolute neutrophil counts (ANC) and decreases neutrophil tissue responses, but its effects on bone marrow functions are not yet known. We conducted a double-blind, randomized study in 18 healthy subjects comparing the effects of either MK-7123 (30mg, po, daily for 28days) or placebo on peripheral blood counts and bone marrow myeloid cell populations. MK-7123 caused a reversible decrease (approximately 50%) in the ANC as demonstrated on days 1 and 28, the first and last days of the treatment period. Bone marrow aspirate smears and biopsy imprints did not differ in the proportion of mature neutrophils in pretreatment, day 28, day 56 or placebo samples. There were no treatment effects on biopsy or aspirate clot cellularity, myeloid to erythroid or myeloid post-mitotic to mitotic ratios; flow-cytometric analyses of aspirate cells; or bone marrow fat to cell balance as assessed by MRI. MK-7123 was generally well tolerated with neutropenia being the most common adverse event; however, there were no clinical symptoms associated with decreased ANCs. These findings indicate that the CXCR2 antagonist MK-7123 causes rapidly reversible decrease in the ANC without measurable myelosuppressive effects. The results support the development of CXCR2 antagonists as potentially useful anti-inflammatory agents, primarily interrupting neutrophil trafficking.

Lung inflammation changes and oxidative stress induced by cigarette smoke exposure in guinea pigs affected by Zataria multiflora and its constituent, carvacrol

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is an epidemic and progressive health problem which is mainly a consequence of cigarette smoking, and associated with lung inflammation. Anti-inflammatory property of Zataria multiflora (Z. multiflora) and its constituent, carvacrol was shown in various inflammatory disorders previously. Therefore, in the present study, the effects of the plant and its constituent, carvacrol, on lung inflammation changes and oxidative stress, in guinea pigs model of COPD were evaluated.

METHODS

Nine groups of animals including control, COPD, COPD + drinking water containing three concentrations of extract of Z. multiflora (0.4, 0.8, and 1.6 mg/mL), COPD + drinking water containing three concentrations of carvacrol (60, 120, and 240 μg/mL), and COPD + dexamethasone (50 μg/mL) were studied. For inducing COPD, animals were exposed to cigarette smoke for 3 months. Thiol groups, IL-8, total and differential WBC were measured in broncho-alveolar lavage fluid (BALF) (n = 6 for each group).

RESULTS

Total WBC, eosinophils, and neutrophils counts as well as the levels of IL-8 in BALF were significantly increased but thiol group was decreased in COPD compared to the control group (p < 0.05 to p < 0.001). Total WBC and IL-8 in all treated COPD groups, thiol group, eosinophils and neutrophils counts in treated groups with dexamethasone and two higher concentrations of the Z. multiflora and carvacrol were significantly improved compared to non-treated COPD group (p < 0.05 to p < 0.001). Lymphocyte count in treated groups with dexamethasone, highest concentration of Z. multiflora, and two higher concentration of carvacrol was also significantly higher than non-treated group (p < 0.05 to p < 0.001).

CONCLUSIONS

A preventive effect of Z. multiflora extract and its constituent carvacrol on lung inflammation changes and oxidative stress in animal model of COPD was suggested.

Virus-induced modulation of lower airway diseases: pathogenesis and pharmacologic approaches to treatment

Uncomplicated upper respiratory viral infections are the most common cause of days lost from work and school and exert a major economic burden. In susceptible individuals, however, common respiratory viruses, particularly human rhinoviruses, also can have a major impact on diseases that involve the lower airways, including asthma, chronic obstructive pulmonary diseases (COPD) and cystic fibrosis (CF). Respiratory virus-induced wheezing illnesses in early life are a significant risk factor for the subsequent development of asthma, and virus infections may also play a role in the development and progression of airway remodeling in asthma. It is clear that upper respiratory tract virus infections can spread to the lower airway and trigger acute attacks of asthma, COPD or CF. These exacerbations can be life-threatening, and exert an enormous burden on health care systems. In recent years we have gained new insights into the mechanisms by which respiratory viruses may induce acute exacerbations of lower airway diseases, as well as into host defense pathways that may regulate the outcomes to viral infections. In the current article we review the role of viruses in lower airway diseases, including our current understanding on pathways by which they may cause remodeling and trigger acute exacerbations. We also review the efficacy of current and emerging therapies used to treat these lower airway diseases on the outcomes due to viral infection, and discuss alternative therapeutic approaches for the management of virus-induced airway inflammation.

Acetylcholine beyond bronchoconstriction: roles in inflammation and remodeling

Acetylcholine is the primary parasympathetic neurotransmitter in the airways, where it not only induces bronchoconstriction and mucus secretion, but also regulates airway inflammation and remodeling. In this review, we propose that these effects are all primarily mediated via the muscarinic M3 receptor. Acetylcholine promotes inflammation and remodeling via direct effects on airway cells, and via mechanical stress applied to the airways sequential to bronchoconstriction. The effects on inflammation and remodeling are regulated by both neuronal and non-neuronal acetylcholine. Taken together, we believe that the combined effects of anticholinergic therapy on M3-mediated bronchoconstriction, mucus secretion, inflammation, and remodeling may account for the positive outcome of treatment with these drugs for patients with chronic pulmonary obstructive disease (COPD) or asthma.

Targeting pro-resolution pathways to combat chronic inflammation in COPD

Chronic obstructive pulmonary disease (COPD) is an inflammatory lung condition that is associated with irreversible airflow obstruction as a consequence of small airways disease, excessive mucus production and emphysema. Paradoxically, excessive inflammation fails to control microbial pathogens that not only colonise COPD airways, but also trigger acute exacerbations, which markedly increase inflammation underlying host tissue damage. Excessive production of leukocyte mobilising cytokines such as CXCL8 (IL-8) and leukotriene B4 (LTB4) in response to environmental stimuli (cigarette smoke and microbial products) are thought to maintain chronic inflammation, in conjunction with inefficient macrophage clearance of microbes and apoptotic neutrophils. In this perspective, we discuss an alternative view on why inflammation persists with a focus on why pro-resolution mediators such as lipoxin A4 (LXA4), D-series resolving and Annexin A1 fail to effectively switch off inflammation in COPD. These pro-resolving mediators converge on the G-protein coupled receptor, ALX/FPR2. This receptor is particularly relevant to COPD as the complex milieu of exogenous and host-derived mediators within the inflamed airways include agonists that potently activate ALX/FPR2, including Serum Amyloid A (SAA) and the cathelicidin, LL-37. There is emerging evidence to suggest that ALX/FPR2 can exist in alternative receptor conformations in an agonist-biased manner, which facilitates alternate functional receptor behaviors. Hence, the development of more stable pro-resolving analogs provides therapeutic opportunities to address ALX/FPR2 conformations to counteract pathogenic signaling and promote non-phlogistic clearance pathways essential for resolution of inflammation.

IL-17A and serum amyloid A are elevated in a cigarette smoke cessation model associated with the persistence of pigmented macrophages, neutrophils and activated NK cells

While global success in cessation advocacy has seen smoking rates fall in many developed countries, persistent lung inflammation in ex-smokers is an increasingly important clinical problem whose mechanistic basis remains poorly understood. In this study, candidate effector mechanisms were assessed in mice exposed to cigarette smoke (CS) for 4 months following cessation from long term CS exposure. BALF neutrophils, CD4⁺ and CD8⁺ T cells and lung innate NK cells remained significantly elevated following smoking cessation. Analysis of neutrophil mobilization markers showed a transition from acute mediators (MIP-2α, KC and G-CSF) to sustained drivers of neutrophil and macrophage recruitment and activation (IL-17A and Serum Amyoid A (SAA)). Follicle-like lymphoid aggregates formed with CS exposure and persisted with cessation, where they were in close anatomical proximity to pigmented macrophages, whose number actually increased 3-fold following CS cessation. This was associated with the elastolytic protease, MMP-12 (macrophage metallo-elastase) which remained significantly elevated post-cessation. Both GM-CSF and CSF-1 were significantly increased in the CS cessation group relative to the control group. In conclusion, we show that smoking cessation mediates a transition to accumulation of pigmented macrophages, which may contribute to the expanded macrophage population observed in COPD. These macrophages together with IL-17A, SAA and innate NK cells are identified here as candidate persistence determinants and, we suggest, may represent specific targets for therapies directed towards the amelioration of chronic airway inflammation.

Potentiated interaction between ineffective doses of budesonide and formoterol to control the inhaled cadmium-induced up-regulation of metalloproteinases and acute pulmonary inflammation in rats

The anti-inflammatory properties of glucocorticoids are well known but their protective effects exerted with a low potency against heavy metals-induced pulmonary inflammation remain unclear. In this study, a model of acute pulmonary inflammation induced by a single inhalation of cadmium in male Sprague-Dawley rats was used to investigate whether formoterol can improve the anti-inflammatory effects of budesonide. The cadmium-related inflammatory responses, including matrix metalloproteinase-9 (MMP-9) activity, were evaluated. Compared to the values obtained in rats exposed to cadmium, pretreatment of inhaled budesonide (0.5 mg/15 ml) elicited a significant decrease in total cell and neutrophil counts in bronchoalveolar lavage fluid (BALF) associated with a significant reduction of MMP-9 activity which was highly correlated with the number of inflammatory cells in BALF. Additionally, cadmium-induced lung injuries characterized by inflammatory cell infiltration within alveoli and the interstitium were attenuated by the pre-treatment of budesonide. Though the low concentration of budesonide (0.25 mg/15 ml) exerted a very limited inhibitory effects in the present rat model, its combination with an inefficient concentration of formoterol (0.5 mg/30 ml) showed an enhanced inhibitory effect on neutrophil and total cell counts as well as on the histological lung injuries associated with a potentiation of inhibition on the MMP-9 activity. In conclusion, high concentration of budesonide alone could partially protect the lungs against cadmium exposure induced-acute neutrophilic pulmonary inflammation via the inhibition of MMP-9 activity. The combination with formoterol could enhance the protective effects of both drugs, suggesting a new therapeutic strategy for the treatment of heavy metals-induced lung diseases.

Increased of exhaled breath condensate neutrophil chemotaxis in acute exacerbation of COPD

Background

Neutrophils have been involved in the pathogenesis of chronic obstructive pulmonary disease (COPD). Underlying mechanisms of neutrophil accumulation in the airways of stable and exacerbated COPD patients are poorly understood. The aim of this study was to assess exhaled breath condensate (EBC) neutrophil chemotactic activity, the level of two chemoattractants for neutrophils (GRO-α and LTB4) during the course of an acute exacerbation of COPD (AECOPD).

Methods

50 ex smoking COPD patients (33 with acute exacerbation and 17 in stable disease) and 20 matched ex smoking healthy controls were compared. EBC was collected by using a commercially available condenser (EcoScreen®). EBC neutrophil chemotactic activity (NCA) was assessed by using Boyden microchambers. Chemotactic index (CI) was used to evaluate cell migration. LTB₄ and GROα levels were measured by a specific enzyme immunoassay in EBC.

Results

Stable COPD and outpatients with AECOPD, but not hospitalized with AECOPD, had raised EBC NCA compared to healthy subjects (p < 0.05 and p < 0.01 respectively). In outpatients with AECOPD EBC NCA significantly decreased 6 weeks after the exacerbation. Overall EBC NCA was weakly correlated with sputum neutrophil counts (r = 0.26, p < 0.05).

EBC LTB4 levels were increased in all groups of COPD compared to healthy subjects while GRO-α was only raised in patients with AECOPD. Furthermore, EBC LTB₄ and GRO-α significantly decreased after recovery of the acute exacerbation. Increasing concentrations (0.1 to 10 μg/mL) of anti- human GRO-α monoclonal antibody had no effect on EBC neutrophil chemotactic activity of 10 exacerbated COPD patients.

Conclusions

EBC NCA rose during acute exacerbation of COPD in ambulatory patients and decreased at recovery. While LTB4 seems to play a role both in stable and in exacerbated phase of the disease, the role of GRO-α as a chemotactic factor during AECOPD is not clearly established and needs further investigation.

Development and characterization of a long-term murine model of Streptococcus pneumoniae infection of the lower airways

Chronic obstructive pulmonary disease (COPD) is characterized by long periods of stable symptoms, but exacerbations occur, which result in a permanent worsening of symptoms. Previous studies have shown a link between bacterial colonization of the lower airways of COPD sufferers and an increase in exacerbation frequency. One of the most frequent bacterial colonizers is Streptococcus pneumoniae. To mimic this aspect of COPD, a murine model of low-level pneumococcal colonization in the lung has been developed, in which S. pneumoniae persisted in the lungs for at least 28 days. From day 14 postinfection, bacterial numbers remained constant until at least 28 days postinfection, and animals showed no outward signs of disease. The bacterial presence correlated with a low-level inflammatory response that was localized to small foci across the left and inferior lobes of the lung. The cellular response was predominantly monocytic, and focal fibroplasia was observed at the airway transitional zones. Physiological changes in the lungs were investigated with a Forced Maneuvers system. This new model provides a means of study of a long-term pulmonary infection with a human pathogen in a rodent system. This is an excellent tool for the development of future models that mimic complex respiratory diseases such as COPD and asthma.

Effect of the Zataria multiflora on systemic inflammation of experimental animals model of COPD

The effects of Zataria multiflora (Z. multiflora) on systemic inflammation in guinea pigs model of COPD were examined. Control animals, COPD (induced by exposing animals to cigarette smoke), COPD+drinking water containing three concentrations of the extract of Z. multiflora, and COPD+dexamethasone were studied (n=6 for each group). Serum levels of IL-8 and malondialdehyde (MDA), total blood WBC (P<0.01 for all cases), and eosinophil counts (P<0.05) were higher and weight changes (P<0.05) were lower in the COPD group compared to controls. IL-8 level (P<0.001) and weight changes (P<0.01 to P<0.001) in all treated groups with Z. multiflora and total WBC number and MDA level in treated groups with two higher concentrations of the extract and lymphocytes percentage (P<0.05) in the highest concentration of Z. multiflora and dexamethasone (P<0.05 to P<0.001) were significantly improved compared to the COPD group. Results showed a preventive effect of hydroethanolic extract from Z. multiflora on all measured parameters in animals model of COPD which was comparable or even higher (in the highest concentration) compared to the effect of dexamethasone at the concentration used.

Targeting IL-1β and IL-17A driven inflammation during influenza-induced exacerbations of chronic lung inflammation

For patients with chronic lung diseases, such as chronic obstructive pulmonary disease (COPD), exacerbations are life-threatening events causing acute respiratory distress that can even lead to hospitalization and death. Although a great deal of effort has been put into research of exacerbations and potential treatment options, the exact underlying mechanisms are yet to be deciphered and no therapy that effectively targets the excessive inflammation is available. In this study, we report that interleukin-1β (IL-1β) and interleukin-17A (IL-17A) are key mediators of neutrophilic inflammation in influenza-induced exacerbations of chronic lung inflammation. Using a mouse model of disease, our data shows a role for IL-1β in mediating lung dysfunction, and in driving neutrophilic inflammation during the whole phase of viral infection. We further report a role for IL-17A as a mediator of IL-1β induced neutrophilia at early time points during influenza-induced exacerbations. Blocking of IL-17A or IL-1 resulted in a significant abrogation of neutrophil recruitment to the airways in the initial phase of infection or at the peak of viral replication, respectively. Therefore, IL-17A and IL-1β are potential targets for therapeutic treatment of viral exacerbations of chronic lung inflammation

Current drug treatment, chronic and acute

The appropriate management of chronic obstructive pulmonary disease (COPD) involves more than taking prescription medicines. The key components have been set out in detail in many treatment guidelines, both national and international. They include the avoidance of identified risk factors, especially tobacco smoking, and the optimization of daily physical activity. This article reviews the key components of the pharmacologic treatment of COPD, both acute and chronic, with an emphasis on those recent studies, which are likely to change practice in the next few years.

Cytokine inhibition in the treatment of COPD

Cytokines play an important part in many pathobiological processes of chronic obstructive pulmonary disease (COPD), including the chronic inflammatory process, emphysema, and altered innate immune response. Proinflammatory cytokines of potential importance include tumor necrosis factor (TNF)-α, interferon-γ, interleukin (IL)-1β, IL-6, IL-17, IL-18, IL-32, and thymic stromal lymphopoietin (TSLP), and growth factors such as transforming growth factor-β. The current objectives of COPD treatment are to reduce symptoms, and to prevent and reduce the number of exacerbations. While current treatments achieve these goals to a certain extent, preventing the decline in lung function is not currently achievable. In addition, reversal of corticosteroid insensitivity and control of the fibrotic process while reducing the emphysematous process could also be controlled by specific cytokines. The abnormal pathobiological process of COPD may contribute to these fundamental characteristics of COPD, and therefore targeting cytokines involved may be a fruitful endeavor. Although there has been much work that has implicated various cytokines as potentially playing an important role in COPD, there have been very few studies that have examined the effect of specific cytokine blockade in COPD. The two largest studies that have been reported in the literature involve the use of blocking antibody to TNFα and CXCL8 (IL-8), and neither has provided benefit. Blocking the actions of CXCL8 through its CXCR2 receptor blockade was not successful either. Studies of antibodies against IL-17, IL-18, IL-1β, and TSLP are currently either being undertaken or planned. There is a need to carefully phenotype COPD and discover good biomarkers of drug efficacy for each specific target. Specific groups of COPD patients should be targeted with specific anticytokine therapy if there is evidence of high expression of that cytokine and there are features of the clinical expression of COPD that will respond.

Dual PDE3/4 and PDE4 inhibitors: novel treatments for COPD and other inflammatory airway diseases

Selective phosphodiesterase (PDE) 4 and dual PDE3/4 inhibitors have attracted considerable interest as potential therapeutic agents for the treatment of respiratory diseases, largely by virtue of their anti-inflammatory (PDE4) and bifunctional bronchodilator/anti-inflammatory (PDE3/4) effects. Many of these agents have, however, failed in early development for various reasons, including dose-limiting side effects when administered orally and lack of sufficient activity when inhaled. Indeed, only one selective PDE4 inhibitor, the orally active roflumilast-n-oxide, has to date received marketing authorization. The majority of the compounds that have failed were, however, orally administered and non-selective for either PDE3 (A,B) or PDE4 (A,B,C,D) subtypes. Developing an inhaled dual PDE3/4 inhibitor that is rapidly cleared from the systemic circulation, potentially with subtype specificity, may represent one strategy to improve the therapeutic index and also exhibit enhanced efficacy versus inhibition of either PDE3 or PDE4 alone, given the potential positive interactions with regard to anti-inflammatory and bronchodilator effects that have been observed pre-clinically with dual inhibition of PDE3 and PDE4 compared with inhibition of either isozyme alone. This MiniReview will summarize recent clinical data obtained with PDE inhibitors and the potential for these drugs to treat COPD and other inflammatory airways diseases such as asthma and cystic fibrosis.

CXCL5 knockdown expression inhibits human bladder cancer T24 cells proliferation and migration

CXCL5 (epithelial neutrophil activating peptide-78) which acts as a potent chemoattractant and activator of neutrophil function was reported to play a multifaceted role in tumorigenesis. To investigate the role of CXCL5 in bladder cancer progression, we examined the CXCL5 expression in bladder cancer tissues by real-time PCR and Western blot, additionally, we used shRNA-mediated silencing to generate stable CXCL5 silenced bladder cancer T24 cells and defined its biological functions. Our results demonstrated that mRNA and protein of CXCL5 is increased in human bladder tumor tissues and cell lines, down-regulation of CXCL5 in T24 cells resulted in significantly decreased cell proliferation, migration and increased cell apoptosis in vitro through Snail, PI3K-AKT and ERK1/2 signaling pathways. These data suggest that CXCL5 is critical for bladder tumor growth and progression, it may represent a potential application in cancer diagnosis and therapy.

Lungs, bone marrow, and adipose tissue. A network approach to the pathobiology of chronic obstructive pulmonary disease

Patients with chronic obstructive pulmonary disease (COPD) often suffer other concomitant disorders, such as cardiovascular diseases and metabolic disorders, that influence significantly (and independently of lung function) their health status and prognosis. Thus, COPD is not a single organ condition, and disturbances of a complex network of interorgan connected responses occur and modulate the natural history of the disease. Here, we propose a novel hypothesis that considers a vascularly connected network with (1) the lungs as the main external sensor of the system and a major source of "danger signals"; (2) the endothelium as an internal sensor of the system (also a potential target tissue); and (3) two key responding elements, bone marrow and adipose tissue, which produce both inflammatory and repair signals. According to the model, the development of COPD, and associated multimorbidities (here we focus on cardiovascular disease as an important example), depend on the manner in which the vascular connected network responds, adapts, or fails to adapt (dictated by the genetic and epigenetic background of the individual) to the inhalation of particles and gases, mainly in cigarette smoke. The caveats and limitations of the hypothesis, as well as the experimental and clinical research needed to test and explore the proposed model, are also briefly discussed.

Implementing lessons learned from previous bronchial biopsy trials in a new randomized controlled COPD biopsy trial with roflumilast

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a chronic inflammatory disease mediated by an array of inflammatory cells and mediators, but above all, CD8+ T-lymphocytes, macrophages and neutrophils are important players in disease pathogenesis. Roflumilast, a first-in-class, potent and selective phosphodiesterase 4 (PDE4) inhibitor, reduces the rate of exacerbations in patients with a high risk of future exacerbations and has been shown to reduce inflammatory cells and mediators in induced sputum, a surrogate of airway inflammation. However, these anti-inflammatory effects are yet to be confirmed in another robust study directly assessing inflammatory markers in bronchial sub-mucosa.

METHODS/DESIGN

An international, 16-week, randomized, double-blind, placebo-controlled, parallel-group study investigating the effects of roflumilast 500 μg once-daily versus placebo on inflammatory parameters in bronchial biopsy tissue specimens, sputum and blood serum. One hundred and fifty patients with COPD and chronic bronchitis for at least 12 months will be recruited into the study and randomized in a 1:1 ratio to receive either roflumilast or placebo. The primary endpoint will be the number of CD8+ cells (cell counts per mm2) in bronchial biopsy tissue specimens (sub-mucosa) and the key secondary endpoint will be the number of CD68+ cells (cell counts per mm2), assessed by indirect immunohistochemistry.

DISCUSSION

It is hypothesized that treatment with roflumilast reduces the characteristic inflammation found in the airways of patients with moderate-to-severe COPD, compared with placebo. The design of the present study has built on the work of previous bronchial biopsy studies available in the literature. It is hoped that it will reveal the cellular mechanisms underlying the anti-inflammatory effects of roflumilast and identify potentially important biomarkers and other surrogate endpoints in patients with COPD. The design and rationale for this trial are described herein.

Inhibition of LPS-induced airway neutrophilic inflammation in healthy volunteers with an oral CXCR2 antagonist

Background

Inhaled lipopolysaccharide (LPS) induces a dose-dependent, acute neutrophilic response in the airways of healthy volunteers that can be quantified in induced sputum. Chemokines, such as CXCL1 and CXCL8, play an important role in neutrophilic inflammation in the lung through the activation of CXCR2 and small molecule antagonists of these receptors have now been developed. We investigated the effect of AZD8309, a CXCR2 antagonist, compared with placebo on LPS-induced inflammation measured in sputum of healthy volunteers.

Methods

Twenty healthy subjects were randomized in a double-blind placebo-controlled, cross-over study. AZD8309 (300 mg) or placebo was dosed twice daily orally for 3 days prior to challenge with inhaled LPS and induced sputum was collected 6 h later.

Results

Treatment with AZD8309 showed a mean 77% reduction in total sputum cells (p < 0.001) and 79% reduction in sputum neutrophils (p < 0.05) compared with placebo after LPS challenge. There was also a reduction in neutrophil elastase activity (p < 0.05) and CXCL1 (p < 0.05) and trends for reductions in sputum macrophages (47%), leukotriene B₄ (39%) and CXCL8 (52%).

Conclusions

AZD8309 inhibited LPS-induced inflammation measured in induced sputum of normal volunteers, indicating that this treatment may be useful in the treatment of neutrophilic diseases of the airways, such as COPD, severe asthma and cystic fibrosis.

Trial registration

NCT00860821.

Significance of the microbiome in chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is one of few chronic disorders with rising mortality and morbidity. It is a highly prevalent disorder, characterized by highly heterogeneous clinical symptoms, health status, and disease progression. COPD is also characterized by an inflammatory/immune response that persists despite smoking cessation and varies by the patient population, method of assessment, and timing of measurement. Bacterial colonization or infection is ubiquitous in patients with COPD and, until recently, has been predominantly assessed using culture-based methodologies. This colonization has been believed to be biologically relevant. It has been estimated that more than 70% of the bacterial species on body surfaces cannot be cultured by standard techniques. As such, advanced culture-independent techniques have been developed that target bacterial genes, such as the 16S ribosomal RNA gene, that function as molecular chronometers. Application of these techniques in patients with COPD has suggested microbial diversity that varies by age, disease severity, and medication use. All of these data provide unique and rapidly evolving insight into the potential role of the respiratory microbiome in disease genesis and expression.

From Childhood Asthma to Chronic Obstructive Pulmonary Disease: Evidence Supporting a Disease Continuum

In this review, we analyze the available evidence showing a link between asthma and chronic obstructive pulmonary disease (COPD). Many features (epidemiologic, physiologic, and histologic) overlap between these two conditions. Both environmental cigarette smoke exposure and early lung development are risk factors for the development of asthma and COPD. However, recent studies suggest that up to 25% of COPD cases were nonsmokers. Asthma during early childhood, independent of smoking history, may be an independent risk factor for the later development of COPD. One explanation for this phenomenon suggests that early small airway dysfunction (including chronic airway inflammation and airway remodeling) can lead to permanent impairment in lung physiology. Several reasons why control of airway inflammation is difficult in some patients are explored. Finally, we examine the available evidence suggesting overlapping histologic features in both asthma and COPD.

CXCL5 contributes to tumor metastasis and recurrence of intrahepatic cholangiocarcinoma by recruiting infiltrative intratumoral neutrophils

CXCL5 is a member of the CXC-type chemokine family that may play a role in carcinogenesis and cancer progression. This study investigates the biological function and clinical significance of CXCL5 in intrahepatic cholangiocarcinoma (ICC). We demonstrated that CXCL5 was overexpressed in ICC cell lines and tumor samples compared with paired normal tissues. CXCL5 had a direct chemoattractant effect on neutrophils in vitro through PI3K-Akt and extracellular signal-regulated kinase 1/2 signaling pathways. In animal studies, CXCL5 promoted tumor growth and metastasis without altering in vitro proliferative and invasive ability of ICC cells, and this effect was mediated by the recruitment of intratumoral infiltrative neutrophils by tumor-derived CXCL5. Immunohistochemical analysis of ICC samples showed that overexpression of CXCL5 correlated strongly with intratumoral neutrophil infiltration, shorter overall survival and high tumor recurrence. Multivariate analysis revealed that CXCL5 overexpression alone, or combined with the presence of intratumoral neutrophils, was an independent prognostic indicator for ICC. In conclusion, our data showed that CXCL5 promotes ICC growth and metastasis by recruiting intratumoral neutrophils. CXCL5 alone or combined with intratumoral neutrophils is a novel prognostic predictor for ICC patients and a potential therapeutic target.