Effects of budesonide and formoterol on NF-kappaB, adhesion molecules, and cytokines in asthma

Drug repurposing screen identifies novel anti-inflammatory activity of sunitinib in macrophages

Inflammation is a driver of human disease and an unmet clinical need exists for new anti-inflammatory medicines. As a key cell type in both acute and chronic inflammatory pathologies, macrophages are an appealing therapeutic target for anti-inflammatory medicines. Drug repurposing - the use of existing medicines for novel indications - is an attractive strategy for the identification of new anti-inflammatory medicines with reduced development costs and lower failure rates than de novo drug discovery. In this study, FDA-approved medicines were screened in a murine macrophage NF-κB reporter cell line to identify potential anti-inflammatory drug repurposing candidates. The multi-tyrosine kinase inhibitor sunitinib was found to be a potent inhibitor of NF-κB activity and suppressor of inflammatory mediator production in murine bone marrow derived macrophages. Furthermore, oral treatment with sunitinib in mice was found to reduce TNFα production, inflammatory gene expression and organ damage in a model of endotoxemia via inhibition of NF-κB. Finally, we revealed sunitinib to have immunomodulatory effects in a model of chronic cardiovascular inflammation by reducing circulating TNFα. This study validates drug repurposing as a strategy for the identification of novel anti-inflammatory medicines and highlights sunitinib as a potential drug repurposing candidate for inflammatory disease via inhibition of NF-κB signalling.

Association of GAB1 gene with asthma susceptibility and the efficacy of inhaled corticosteroids in children

Asthma is a polygenic disease that may onset during childhood. Inhaled corticosteroids (ICS) are the main therapy in asthma, although their efficacy varies among individuals. Nuclear factor κB (NF-κB) is an important target of ICS treatment of asthma. Recent research has reported that GRB2 associated binding protein 1 (GAB1) gene may participate in the pathogenesis of asthma by regulating the NF-κB pathway. Therefore, we used the technique of an improved multiplex ligation detection reaction to sequence GAB1 gene and investigated the involvement of Single-nucleotide variants (SNVs) in GAB1 gene in asthma and ICS efficacy in asthmatic children. We found no differences between asthma cases and controls in allele or genotype frequencies of GAB1. Haplotype analysis showed an increased tendency for AGGAGC frequency in asthma patients compared with controls (OR = 2.69, p = 0.018). The percentage of EOS and genotype distribution of rs1397527 were associated (p = 0.007). The EOS percentage was higher in GT genotype when compared to the GG genotype (5.50 vs 3.00, Bonferroni adjusted p = 0.005). After 12-weeks ICS treatment, GAB1 rs1397527 TT and GT genotype carriers had a smaller change in forced expiratory volume in 1 second/forced vital capacity (FEV1/FVC) than GG carriers (p = 0.009), and rs3805236 GG and AG genotype carriers also had a smaller change in FEV1/FVC than AA carriers (p = 0.025). For ICS response, the frequency of GG genotype of rs1397527 was significantly higher in good responders (p = 0.038). The generalized multifactor dimensionality reduction (GMDR) analysis showed a best significant four-order model (rs1397527, allergen exposure, environmental tobacco smoke exposure, and pet exposure) involving gene-environment interactions (p = 0.001). In summary, we found that GAB1 SNVs were not associated with asthma susceptibility. Haplotype AGGAGC was a risk factor for asthma. GAB1 variants were associated with eosinophils and ICS response in asthmatics. Furthermore, gene-environment interaction was observed.

Budesonide/glycopyrronium/formoterol fumarate triple therapy prevents pulmonary hypertension in a COPD mouse model via NFκB inactivation

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a health problem that results in death, commonly due to the development of pulmonary hypertension (PH). Here, by utilizing a mouse model of intratracheal elastase-induced emphysema that presents three different phases of COPD, we sought to observe whether budesonide/glycopyrronium/formoterol fumarate (BGF) triple therapy could prevent COPD-PH in addition to ameliorating COPD progression.

METHODS

We utilized intratracheal elastase-induced emphysema mouse model and performed experiments in three phases illustrating COPD progression: inflammatory (1 day post-elastase), emphysema (3 weeks post-elastase) and PH (4 weeks post-elastase), while treatments of BGF and controls (vehicle, one-drug, and two-drug combinations) were started in prior to elastase instillation (inflammatory phase), at day 7 (emphysema), or at day 14 (PH phase). Phenotype analyses were performed in each phase. In vitro, A549 cells or isolated mouse lung endothelial cells (MLEC) were treated with TNFα with/without BGF treatment to analyze NFκB signaling and cytokine expression changes.

RESULTS

We observed significant reductions in the proinflammatory phenotype observed in the lungs and bronchoalveolar lavage fluid (BALF) 1 day after elastase administration in mice treated with BGF compared with that in mice administered elastase alone (BALF neutrophil percentage, p = 0.0011 for PBS/Vehicle vs. PBS/Elastase, p = 0.0161 for PBS/Elastase vs. BGF). In contrast, only BGF treatment significantly ameliorated the elastase-induced emphysematous lung structure and desaturation after three weeks of elastase instillation (mean linear intercept, p = 0.0156 for PBS/Vehicle vs. PBS/Elastase, p = 0.0274 for PBS/Elastase vs. BGF). Furthermore, BGF treatment prevented COPD-PH development, as shown by improvements in the hemodynamic and histological phenotypes four weeks after elastase treatment (right ventricular systolic pressure, p = 0.0062 for PBS/Vehicle vs. PBS/Elastase, p = 0.027 for PBS/Elastase vs. BGF). Molecularly, BGF acts by inhibiting NFκB-p65 phosphorylation and subsequently decreasing the mRNA expression of proinflammatory cytokines in both alveolar epithelial and pulmonary endothelial cells.

CONCLUSION

Our results collectively showed that BGF treatment could prevent PH in addition to ameliorating COPD progression via the inhibition of inflammatory NFκB signaling.

Dexamethasone can attenuate the pulmonary inflammatory response via regulation of the lncH19/miR-324-3p cascade

Objective

To investigate lncRNAs and their roles in regulating the pulmonary inflammatory response under dexamethasone (Dex) treatment.

Methods

IL-1β (10 ng/mL) and LPS (1 μg/mL) was used to construct inflammatory cell models with A549 cells; IL-1β performed better against LPS. Different concentrations of Dex were used to attenuate the inflammation induced by IL-1β, and its effect was assessed via RT-PCR to detect inflammatory cytokine-related mRNA levels, including those of IKβ-α, IKKβ, IL-6, IL-8, and TNF-α. Furthermore, ELISA was used to detect the levels of the inflammatory cytokines TNF-α, IL-6, and IL-8. RT-PCR was used to quantify the levels of lncRNAs, including lncMALAT1, lncHotair, lncH19, and lncNeat1. LncH19 was most closely associated with the inflammatory response, which was induced by IL-1β and attenuated by Dex. Among the lncRNAs, the level of lncH19 showed the highest increase following treatment with 1 and 10 μM Dex. Therefore, lncH19 was selected for further functional studies. LncH19 expression was inhibited by shRNA transduced with lentivirus. Cell assays for cell proliferation and apoptosis as well as RT-PCR, western blot, and ELISA for inflammatory genes were conducted to confirm the functions of lncH19. The predicted target miRNAs of lncH19 were hsa-miR-346, hsa-miR-324-3p, hsa-miR-18a-3p, hsa-miR-18b-5p, hsa-miR-146b-3p, hsa-miR-19b-3p, and hsa-miR-19a-3p. Following estimation via RT-PCR, hsa-miR-346, hsa-miR-18a-3p, and hsa-miR-324-3p showed consistent patterns in A549 NC and A549 shlncH19. An miRNA inhibitor was transfected into A549 NC and A549 shlncH19 cells, and the expression levels were determined via RT-PCR. hsa-miR-324-3p was inhibited the most compared with hsa-miR-346 and hsa-miR-18a-3p and was subjected to further functional studies. RT-PCR, ELISA, and western blotting for inflammatory gene detection were conducted to validate the functions of the target hsa-miR-324-3p.

Results

Treatment with 1 and 10 μM Dex could effectively attenuate the inflammatory response. During this process, lncH19 expression significantly increased (P < 0.05). Therefore, treatment with 1 μM Dex was used for further study. Under IL-1β treatment with or without Dex, lncH19 inhibition led to an increase in cell proliferation; a decrease in cell apoptosis; an increase in the protein levels of inflammatory genes; phosphorylation of P65, ICAM-1, and VCAM-1; and increase inflammatory cytokines. Prediction of the targets of lncH19 and validation via RT-PCR revealed that miR-346, miR-18a-3p, and miR-324-3p negatively correlate with lncH19. Additionally, Dex increased the lncH19 expression but reduced that of the miRNAs. Among the miRNAs, miR-324-3p was the most markedly downregulated miRNA following treatment of miRNA inhibitors. The MTS assay and cell apoptosis assay showed that the miR-324-3p inhibitor inhibited cell proliferation and induced cell apoptosis, thereby significantly attenuating the inflammatory response, which reversed the effect of lncH19 in regulating cell proliferation and the secretion of inflammatory cytokines (P < 0.05). Therefore, lncH19 might regulate miR-324-3p in pulmonary inflammatory response under Dex treatment.

Conclusion

Dex can attenuate the pulmonary inflammatory response by regulating the lncH19/miR-324-3p cascade.

Mechanisms of eosinophilic inflammation

Eosinophils play roles in the pathogenesis of various diseases. In order to accumulate within sites of inflammation, eosinophils must adhere to, and migrate across the microvasculature. These processes are largely controlled by type 2-immune responses; interleukin (IL)-4 and IL-13 induce the expression of endothelial adhesion molecule vascular cell adhesion molecule-1 (VCAM-1), a representative adhesive ligand for eosinophils, while also stimulating generations of CC chemokines from structural cells, including epithelial cells. VCAM-1 and CC chemokines synergistically induce transmigration of eosinophils to the tissue inflammation site. Another type 2 cytokine, IL-5, prolongs survival, and enhances the effector functions of eosinophils. Recently, accumulating evidence has established that corticosteroid-resistant group 2 innate lymphoid cells are cellular sources for IL-5. Another immunological mechanism that may be contributing to eosinophilic inflammation involves type 1 immune system-associated molecules such as interferons and IP-10. In addition to these immune pathways, lipid mediators, such as cysteinyl leukotrienes, directly provoke the infiltration and activation of eosinophils. Extracellular matrix proteins including periostin also induce the adhesion and activation of eosinophils. Finally, activated neutrophils can also induce eosinophil transmigration. In summary, various mechanisms are involved within eosinophilic inflammation, and effective therapeutic strategies targeting these pathways should be established.

Effect of preoperative inhaled budesonide on pulmonary injury after cardiopulmonary bypass: A randomized pilot study

BACKGROUND

Cardiopulmonary bypass can result in lung injury. This prospective, double-blinded, randomized trial aimed to evaluate the protective effect of inhaled budesonide on lung injury after cardiopulmonary bypass.

METHODS

Sixty patients, aged 25 to 65 years, requiring cardiopulmonary bypass were randomized to groups treated with saline or budesonide inhalation preoperatively. The respiratory mechanics were recorded. Bronchoalveolar lavage fluid was collected before cardiopulmonary bypass and after sternal closure. Serum and bronchoalveolar lavage fluid levels of proinflammatory and anti-inflammatory factors were analyzed. The primary end point was the lowest ratio of the partial pressure of arterial oxygen to the fraction of inspired oxygen after cardiopulmonary bypass. The durations of ventilation and postoperative recovery time were noted.

RESULTS

Budesonide significantly improved respiratory mechanics after cardiopulmonary bypass. Budesonide improved the partial pressure of arterial oxygen to the fraction of inspired oxygen ratio from 8 to 48 hours after the operation. Budesonide shortened the durations of mechanical ventilation and postoperative recovery time. Budesonide decreased the levels of proinflammatory factors while increasing the levels of anti-inflammatory factors in bronchoalveolar lavage fluid and serum (all P < .05). The macrophage and neutrophil counts, and protein and elastase concentrations were decreased by budesonide treatment.

CONCLUSIONS

Budesonide treatment shortened the durations of mechanical ventilation, inhibited local and systemic inflammation, and improved respiratory function after cardiopulmonary bypass.

Anti-Inflammatory Peptide Attenuates Edema and Promotes BMP-2-Induced Bone Formation in Spine Fusion

Recombinant human bone morphogenic protein-2 (BMP-2)-loaded absorbable collagen sponges (ACS) have been successfully used to enhance bone formation and to induce spinal fusion in humans. However, side effects, such as soft tissue edema and inflammation, have been reported. NEMO binding domain peptide (NBD) inhibits activation of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), a central regulator of immune response. In this study, we investigated NBD's potential to reduce BMP-2-induced soft tissue inflammation without affecting BMP-2-mediated spinal fusion in rat. For evaluation of soft tissue inflammation, ACS containing BMP-2, BMP-2+NBD, NBD, or ACS only were implanted into intramuscular paraspinal sites of 32 rats. At day 2 postsurgery, edema formation at the implant sites was assessed using magnetic resonance imaging. T2-weighted relaxation time (T2-RT) values were increased in the BMP-2 group compared with BMP-2+NBD, NBD, and ACS groups. No difference in T2-RT values was detected between BMP-2+NBD versus NBD and ACS controls. Postsacrifice, histological analysis of the implant-surrounding zones showed increased mononuclear cell infiltration in the BMP-2 group compared with BMP-2+NBD and controls. The presence of BMP-2 increased relative NF-κB binding and gene expression of inflammatory markers, interleukin (IL)1β, IL6, IL18, and chemokine ligand (CCL)2 and CCL3 compared with controls. In the BMP-2+NBD group, cytokine expression was blocked. No differences were found between BMP-2+NBD and control groups. For evaluation of spinal fusion, posterolateral intertransverse lumbar fusion procedures were performed on 16 rats. ACS were loaded with BMP-2 or BMP-2+NBD. After sacrifice at week 12, microcomputed tomographic assessment of the fusion site detected a higher bone volume and reduced trabecular spacing in the BMP-2+NBD group compared with BMP-2. Histological analysis did not show any differences in newly formed bone microarchitecture. In summary, addition of NBD to BMP-2-loaded ACS reduces BMP-2-induced soft tissue edema formation and mononuclear cell infiltration, diminishes NF-κB binding, and thus blocks transcription of NF-κB-regulated cytokines in rat. Furthermore, NBD stimulates bone formation in BMP-2-mediated spinal fusion, possibly through crosstalk of the NF-κB pathway with other pathways. The results of this study might provide the basis to develop new therapeutic bone grafting approaches with combinatory administration of BMP-2 and NBD for spinal fusion.

Lung inflammatory and oxidative alterations after exogenous surfactant therapy fortified with budesonide in rabbit model of meconium aspiration syndrome

Meconium aspiration syndrome (MAS) triggers inflammatory and oxidative pathways which can inactivate both pulmonary surfactant and therapeutically given exogenous surfactant. Glucocorticoid budesonide added to exogenous surfactant can inhibit inflammation and thereby enhance treatment efficacy. Neonatal meconium (25 mg/ml, 4 ml/kg) was administered intratracheally (i.t.) to rabbits. When the MAS model was prepared, animals were treated with budesonide i.t. (Pulmicort, 0.25 mg/kg, M+B); with surfactant lung lavage (Curosurf®, 10 ml/kg, 5 mg phospholipids/ml, M+S) followed by undiluted Curosurf® i.t. (100 mg phospholipids/kg); with combination of budesonide and surfactant (M+S+B); or were untreated (M); or served as controls with saline i.t. instead of meconium (C). Animals were oxygen-ventilated for additional 5 h. Cell counts in the blood and bronchoalveolar lavage fluid (BAL), lung edema formation (wet/dry weight ratio), oxidative damage of lipids/ proteins and inflammatory expression profiles (IL-2, IL-6, IL-13, TNF-alpha) in the lung homogenate and plasma were determined. Combined surfactant+budesonide therapy was the most effective in reduction of neutrophil counts in BAL, oxidative damage, levels and mRNA expression of cytokines in the lung, and lung edema formation compared to untreated animals. Curosurf fortified with budesonide mitigated lung inflammation and oxidative modifications what indicate the perspectives of this treatment combination for MAS therapy.

Tiron ameliorates oxidative stress and inflammation in a murine model of airway remodeling

Airway remodeling includes lung structural changes that have a role in the irreversibility of pulmonary dysfunction shown in chronic bronchial asthmatics. The current experiment investigated the effect of the mitochondrial antioxidant, tiron in comparison with dexamethasone (DEXA) on airway remodeling in chronic asthma. Sensitized BALB/c mice were challenged with ovalbumin (OVA) aerosol for 8weeks, OVA sensitized-challenged mice were treated with either DEXA or tiron, respectively. After that, lung tissue and bronchoaveolar lavage fluid (BALF) were used for measurement of different biological markers. Lungs were examined for histopathological changes and immunohistochemistry. Upon comparing with vehicle treated animals, trion or DEXA treatment significantly reduced eosinophils, lymphocytes, neutrophils and macrophages count in the BALF. Both drugs significantly alleviated chronic OVA-induced oxidative stress as illustrated by decreased pulmonary malondialdenhyde (MDA) and increased glutathione (GSH) and superoxide dismutase (SOD) levels. Asthmatic mice exhibited elevated levels of NOx, IL-13 and TGF-β1 that were reduced by DEXA and tiron. Histopathological changes and increased immunoreactivity of nuclear factor-Kappa B (NF-κ B) in OVA-challenged mice were minimized by tiron and DEXA treatment. In conclusion, in this model of chronic asthma DEXA and tiron ameliorated airway remodeling and inflammation in experimental chronic asthma with no difference between the effect of tiron and DEXA. Tiron has a potential role as adjuvant treatment in chronic asthma.

Transcription Factor NF-κB: An Update on Intervention Strategies

The nuclear factor (NF)-κB family of transcription factors are ubiquitous and pleiotropic molecules that regulate the expression of more than 150 genes involved in a broad range of processes including inflammation, immunity, cell proliferation, differentiation, and survival. The chronic activation or dysregulation of NF-κB signaling is the central cause of pathogenesis in many disease conditions and, therefore, NF-κB is a major focus of therapeutic intervention. Because of this, understanding the relationship between NF-κB and the induction of various downstream signaling molecules is imperative. In this review, we provide an updated synopsis of the role of NF-κB in DNA repair and in various ailments including cardiovascular diseases, HIV infection, asthma, herpes simplex virus infection, chronic obstructive pulmonary disease, and cancer. Furthermore, we also discuss the specific targets for selective inhibitors and future therapeutic strategies.

Stimulation of the RIG-I/MAVS Pathway by Polyinosinic:Polycytidylic Acid Upregulates IFN-β in Airway Epithelial Cells with Minimal Costimulation of IL-8

Pharmacological stimulation of the antiviral cytokine IFN-β in the airways may help to counter deleterious virus-induced exacerbations in chronic inflammatory lung diseases (asthma, chronic obstructive pulmonary disease, or cystic fibrosis). Polyinosinic-polycytidylic acid [poly(I:C)] is a known inducer of IFN-β but also costimulates an inflammatory response. The latter response is undesirable given the pre-existing airway inflammation in these diseases. The objective of our study was to identify conditions for poly(I:C) to selectively upregulate IFN-β in airway epithelial cells without a concomitant inflammatory response. The inflammatory response was gauged by production of the chemokine IL-8. Using cell lines and primary airway epithelial cells (both submerged and well-differentiated), we observed that pure poly(I:C) stimulated IFN-β mainly through the TLR3/TRIF pathway and IL-8 through an unidentified pathway. The magnitude of the IL-8 response stimulated by pure poly(I:C) matched or even exceeded that of IFN-β. Furthermore, this IL-8 response could not be pharmacologically downregulated without affecting IFN-β. In contrast, we show that stimulation of the RIG-I/MAVS pathway, such as when poly(I:C) is delivered intracellularly in a complex with liposomes or via nucleofection, selectively stimulates IFN-β with low IL-8 costimulation. The magnitude of IFN-β stimulation by liposome-encapsulated poly(I:C) is markedly diminished in well-differentiated cells. In conclusion, it is feasible to augment IFN-β production in airway epithelial cells without excessive costimulation of IL-8 if the RIG-I/MAVS pathway is stimulated, such as via liposomal delivery of poly(I:C). Better cytoplasmic delivery vehicles are needed to efficiently stimulate this pathway in well-differentiated cells.

NF-kappaB Signaling in Chronic Inflammatory Airway Disease

Asthma and chronic obstructive pulmonary disease (COPD) are obstructive airway disorders which differ in their underlying causes and phenotypes but overlap in patterns of pharmacological treatments. In both asthma and COPD, oxidative stress contributes to airway inflammation by inducing inflammatory gene expression. The redox-sensitive transcription factor, nuclear factor (NF)-kappaB (NF-κB), is an important participant in a broad spectrum of inflammatory networks that regulate cytokine activity in airway pathology. The anti-inflammatory actions of glucocorticoids (GCs), a mainstay treatment for asthma, involve inhibition of NF-κB induced gene transcription. Ligand bound GC receptors (GRs) bind NF-κB to suppress the transcription of NF-κB responsive genes (i.e., transrepression). However, in severe asthma and COPD, the transrepression of NF-κB by GCs is negated as a consequence of post-translational changes to GR and histones involved in chromatin remodeling. Therapeutics which target NF-κB activation, including inhibitors of IκB kinases (IKKs) are potential treatments for asthma and COPD. Furthermore, reversing GR/histone acetylation shows promise as a strategy to treat steroid refractory airway disease by augmenting NF-κB transrepression. This review examines NF-κB signaling in airway inflammation and its potential as target for treatment of asthma and COPD.

Budesonide inhalation ameliorates endotoxin-induced lung injury in rabbits

Acute respiratory distress syndrome (ARDS) is a serious clinical problem that has a 30-50% mortality rate. Budesonide has been used to reduce lung injury. This study aims to investigate the effects of nebulized budesonide on endotoxin-induced ARDS in a rabbit model. Twenty-four rabbits were randomized into three groups. Rabbits in the control and budesonide groups were injected with endotoxin. Thereafter, budesonide or saline was instilled, ventilated for four hours, and recovered spontaneous respiratory. Peak pressure, compliance, and PaO2/FiO2 were monitored for 4 h. After seven days, PaO2/FiO2 ratios were measured. Wet-to-dry weight ratios, total protein, neutrophil elastase, white blood cells, and percentage of neutrophils in BALF were evaluated. TNF-α, IL-1β, IL-8, and IL-10 in BALF were detected. Lung histopathologic injury and seven-day survival rate of the three groups were recorded. Peak pressure was downregulated, but compliance and PaO2/FiO2 were upregulated by budesonide. PaO2/FiO2 ratios significantly increased due to budesonide. Wet-to-dry weight ratios, total protein, neutrophil elastase, white blood cells and percentage of neutrophils in BALF decreased in the budesonide group. TNF-α, IL-1β, and IL-8 levels decreased in BALF, while IL-10 levels increased in the budesonide group. Lung injuries were reduced and survival rate was upregulated by budesonide. Budesonide effectively ameliorated respiratory function, attenuated endotoxin-induced lung injury, and improved the seven-day survival rate.

Asthma is not only an airway disease, but also a vascular disease

Multiple studies have identified an expansion and morphological dysregulation of the bronchial vascular network in the airways of asthmatics. Increased number, size and density of blood vessels, as well as vascular leakage and plasma engorgement, have been reported in the airways of patients with all grades of asthma from mild to fatal. This neovascularisation is an increasingly commonly reported feature of airway remodelling; however, the pathophysiological impact of the increased vasculature in the bronchial wall and its significance to pulmonary function in asthma are unrecognised at this time. Multiple factors capable of influencing the development and persistence of the vascular network exist within asthmatic airway tissue. These include structural components of the altered extracellular matrix (ECM), imbalance of proteases and their endogenous inhibitors, release of active matrikines and the dysregulated levels of both soluble and matrix sequestered growth factors. This review will explore the features of the asthmatic airway which influence the development and persistence of the increased vascular network, as well as the effect of enhanced tissue perfusion on chronic inflammation and airway dynamics. The response of cells of the airways to the altered vascular profile and the subsequent influence on the features of airway remodelling will also be highlighted. We will explore the failure of current asthma therapeutics in "normalising" this vascular remodelling. Finally, we will summarize the outcomes of recent clinical trials which provide hope that anti-angiogenic therapies may be a potent asthma-resolving class of drugs and provide a new approach to asthma management in the future.

c-FLIP protects eosinophils from TNF-α-mediated cell death in vivo

Understanding the signals that regulate eosinophil survival and death is critical to developing new treatments for asthma, atopy, and gastrointestinal disease. Previous studies suggest that TNF-α stimulation protects eosinophils from apoptosis, and this TNF-α-mediated protection is mediated by the upregulation of an unknown protein by NF-κB. Here, we show for the first time that eosinophils express the caspase 8-inhibitory protein c-FLIP, and c-FLIP expression is upregulated upon TNF-α stimulation. Considering that c-FLIP expression is regulated by NF-κB, we hypothesized that c-FLIP might serve as the “molecular switch” that converts TNFRI activation to a pro-survival signal in eosinophils. Indeed, we found that one c-FLIP isoform, c-FLIP_L, is required for mouse eosinophil survival in the presence of TNF-α both in vitro and in vivo. Importantly, our results suggest c-FLIP as a potential therapeutic target for the treatment of eosinophil-mediated disease.

Formoterol and budesonide inhibit rhinovirus infection and cytokine production in primary cultures of human tracheal epithelial cells

BACKGROUND

Long-acting β(2) agonists (LABAs) and inhaled corticosteroids (ICSs) reduce the frequency of exacerbations of chronic obstructive pulmonary disease and bronchial asthma. However, inhibitory effects of LABAs and ICSs on the replication of rhinovirus (RV), the major cause of exacerbations, have not been demonstrated.

METHODS

Primary cultures of human tracheal epithelial cells were infected with a major group RV, type 14 rhinovirus (RV14), to examine the effects of formoterol and budesonide on RV infection and infection-induced airway inflammation.

RESULTS

Treatment with formoterol and budesonide 72 h before and after RV14 infection reduced RV14 titers and cytokine concentrations, including interleukin (IL)-1β, IL-6 and IL-8, in supernatants and viral RNA within cells. Formoterol and budesonide reduced mRNA expression and protein concentration of intercellular adhesion molecule-1 (ICAM-1), the receptor for RV14. Formoterol reduced the number and fluorescence intensity of acidic endosomes through which RV RNA enters the cytoplasm. Formoterol and budesonide reduced the activation of the nuclear factor kappa-B protein p65 in nuclear extracts. The effects of formoterol plus budesonide were additive with respect to RV14 replication, cytokine production, ICAM-1 expression, acidic endosome fluorescence intensity, and p65 activation. The selective β(2)-adrenergic receptor antagonist, ICI 118551 [erythro-dl-1-(7-methylindan-4-yloxy)-3-isopropylaminobutan-2-ol], reversed the inhibitory effects of formoterol on RV14 titers and RNA levels, the susceptibility of cells to RV14 infection, cytokine production, acidic endosomes, ICAM-1 expression, and p65 activation.

CONCLUSIONS

Formoterol and budesonide may inhibit RV infection by reducing the ICAM-1 levels and/or acidic endosomes and modulate airway inflammation associated with RV infections.

BMP-2 adverse reactions treated with human dose equivalent dexamethasone in a rodent model of soft-tissue inflammation

STUDY DESIGN

Basic science rodent model of bone morphogenetic protein-2 (BMP-2) soft-tissue inflammation.

OBJECTIVE

This study investigated the anti-inflammatory effect of human dose equivalent (HDE) dexamethasone (DM) for treatment of BMP-2-related soft-tissue inflammation in a rodent model and suggests an appropriate dose for utilization in the clinical practice of spine surgeons.

SUMMARY OF BACKGROUND DATA

BMP-2 is frequently used in spinal surgery to augment fusion. Yet, side effects of soft-tissue inflammation have been observed. DM decreases proinflammatory cytokine production and cellular immune response. However, the anti-inflammatory effects of HDE DM in a rodent model of BMP-2-associated soft-tissue inflammation have not been reported.

METHODS

Five, 10, and 15 mg of HDE DM were administered 3 times perioperatively to rodent cohorts receiving BMP-2 paraspinal implants and compared against BMP-2 only positive controls and phosphate buffer negative controls (n = 6 subjects per group). Histopathology, magnetic resonance imaging, and gross dissection were used as measures of cellular, edematous, and exudative inflammatory response. Serial killings were made on day 2 and day 7 postoperatively.

RESULTS

Magnetic resonance imaging volume rendering demonstrated inflammatory edema decreased by 49% from 605.4 mm to 304.03 mm in subjects treated with 5, 10, or 15 mg of HDE DM (P < 0.05). Histopathological analysis demonstrated inflammatory cross-sectional area decreased 28.8% from 1.84 mm to 1.31 mm in subjects treated with 5, 10 or 15 mg of HDE DM (P < 0.05). Immune cellular infiltration depth decreased 38.5% from 0.26 mm to 0.16 in subjects treated with 15 mg of HDE DM (P < 0.05). Gross anatomical inflammatory exudates were prevented in 100% of subjects treated with 10 or 15 mg of HDE DM (P < 0.05).

CONCLUSION

Low-dose DM administration is effective in controlling the cellular inflammation and edema resulting from BMP-2. Ten or 15 mg of DM might be considered by spine surgeons for controlling the inflammation and edema seen in spine surgery with BMP-2.

Expression levels of induced sputum IL-8 and IL-10 and drug intervention effects in patients with acute exacerbated COPD complicated with chronic cor pulmonale at high altitude

The aim of this study was to assess the expression levels of induced sputum interleukin (IL)-8 and IL-10 levels in patients with acute exacerbated chronic obstructive pulmonary disease (AECOPD) complicated with chronic cor pulmonale (CCP) at high altitude, and to evaluate the intervention effects of an inhaled corticosteroid (ICS) and a β₂-adrenoceptor agonist in this disease. A total of 186 patients with AECOPD complicated with CCP were randomly divided into three groups, with 62 cases in each. With regard to the two treatment groups, group A was treated with salmeterol/fluticasone (50 μg/250 μg, respectively) by airway inhalation twice daily, while group B received budesonide (1 mg) as a spray inhalation, twice daily. The routine treatment group (group C) received only routine treatment. The levels of IL-8 and IL-10 in the induced sputum and the predicted percentage of forced expiratory volume in one second (FEV_1%pred), partial pressure of oxygen in arterial blood (PaO₂) and partial pressure of carbon dioxide in arterial blood (PaCO₂) were examined on admission and at a stable stage two weeks following treatment. Forty healthy volunteers served as a control group (group D). Compared with group D values, the IL-8 induced sputum level and the PaCO₂ were significantly increased, while the level of IL-10, FEV_1%pred and the PaO₂ were markedly decreased in the three COPD groups prior to treatment. Following treatment, the induced sputum IL-8 level and the PaCO₂ were significantly decreased, while the induced sputum IL-10 level, FEV_1%pred and the PaO₂ were markedly increased in the three treatment groups compared with the values pre-therapy (all P<0.01). The post-treatment parameters were significantly different among the three groups (P<0.01). The results indicate that IL-8 and IL-10 are involved in the airway inflammation of AECOPD complicated by CCP. Treatment with an ICS was demonstrated to be a successful method of reducing the local expression of IL-8 and increasing the local expression of IL-10; however, ICS combined with a long-acting β₂-adrenoceptor agonist (LABA) was more effective than the sole administration of ICS in patients with AECOPD complicated by CCP at high altitude.

The Role of Nuclear Factor Kappa B in the Pathogenesis of Pulmonary Diseases: Implications for Therapy

The nuclear factor kappa B (NF-kappaB) transcription factor plays a key role in the induction of pro-inflammatory gene expression, leading to the synthesis of cytokines, adhesion molecules, chemokines, growth factors and enzymes. Results of studies in in vitro and in vivo models of inflammation and malignancy have also suggested central roles for NF-kappaB in programmed cell death, or apoptosis. NF-kappaB plays a central role in a variety of acute and chronic inflammatory diseases. In the common lung diseases associated with a significant inflammatory component such as severe sepsis, acute lung injury, acute respiratory distress syndrome, cystic fibrosis and asthma, the pathogenic roles of NF-kappaB have been extensively investigated. In COPD, activation of NF-kappaB has been implicated in disease pathogenesis but its exact role is less clearly demonstrable in this heterogeneous patient population. However, the principal risk factor for COPD, cigarette smoking, is strongly associated with NF-kappaB activation. Activation of NF-kappaB has been demonstrated in mineral dust diseases and probably plays a role in the pathogenesis of these chronic illnesses. NF-kB also plays a variety of roles in lung cancer including resistance to chemotherapy, inhibition of tumorigenesis and inducing expression of antiapoptotic genes. The complex NF-kappaB pathway offers a variety of potential molecular targets for chemotherapeutic intervention. A variety of agents aimed at modulating NF-kappaB activity are in various stages of investigation.

Epithelial cells, the "switchboard" of respiratory immune defense responses: effects of air pollutants

"Epimmunome", a term introduced recently by Swamy and colleagues, describes all molecules and pathways used by epithelial cells (ECs) to instruct immune cells. Today, we know that ECs are among the first sites within the human body to be exposed to pathogens (such as influenza viruses) and that the release of chemokine and cytokines by ECs is influenced by inhaled agents. The role of the ECs as a switchboard to initiate and regulate immune responses is altered through air pollutant exposure, such as ozone, tobacco smoke and diesel exhaust emissions. The details of the interplay between ECs and immune cells are not yet fully understood and need to be investigated further. Co-culture models, cell specific genetically-modified mice and the analysis of human biopsies provide great tools to gain knowledge about potential mechanisms. Increasing our understanding about the role of ECs in respiratory immunity may yield novel therapeutic targets to modulate downstream diseases.

Stratified medicine in selecting biologics for the treatment of severe asthma

PURPOSE OF REVIEW

Despite optimal treatment, asthma symptoms in about 5-10% of patients remain poorly controlled. Apart from having an impact on their asthma-related quality of life and adverse effects of the medications used (especially corticosteroids), their severe symptoms also impact healthcare resources due to frequent admission and requirement for intensive medications use. The last decade has seen an improved understanding in the pathophysiology of the complex cellular and molecular networks involved in the inflammatory and immunological phenotype of severe asthma. This knowledge may help providing strategies by which these phenotypes operate and pave the way for drug development and individualized treatment.

RECENT FINDINGS

Here we review the current evidence of biological agents in patients with severe asthma recently assessed for safety and efficacy. Some of these agents have shown to be useful in specifically targeted subpopulations of patients with severe asthma, whereas others have proven to be unsafe and/or unsuccessful. In addition, we discuss recent data on clinical and pharmacokinetic-pharmacodynamic aspects of omalizumab, the only licensed anti-IgE therapy for severe atopic asthma.

SUMMARY

More basic science work is required to improve the current understanding of severe asthma pathophysiology and proof-of-concept clinical studies are required to explore relevant biomolecular targets in this small subset of patients. At present, only one drug is licensed for allergic asthmatic patients with severe disease, omalizumab. Novel therapies in the form of oligonucleotide therapies and other biological agents are also being investigated in the difficult-to-treat asthmatic patient group.

Dapsone inhibits IL-8 secretion from human bronchial epithelial cells stimulated with lipopolysaccharide and resolves airway inflammation in the ferret

BACKGROUND

IL-8 is an important activator and chemoattractant for neutrophils that is produced by normal human bronchial epithelial (NHBE) cells through mitogen-activated protein kinase (MAPK) and nuclear factor-κB (NF-κB) p65 pathways. Dapsone, a synthetic sulfone, is widely used to treat chronic neutrophil dermatoses. We investigated the effects of dapsone on polarized IL-8 secretion from lipopolysaccharide (LPS)-stimulated NHBE cells and further evaluated its ability to decrease LPS-induced inflammation in the ferret airway.

METHODS

NHBE cells were grown at air-liquid interface (ALI) to ciliated differentiation. Baseline and endotoxin (LPS)-stimulated IL-8 secretion was measured by enzyme-linked immunosorbent assay at air and basal sides with and without dapsone. Western blotting was used to determine signaling pathways. In vivo, ferrets were exposed to intratracheal LPS over a period of 5 days. Once inflammation was established, oral or nebulized dapsone was administered for 5 days. Intraepithelial neutrophil accumulation was analyzed histologically, and mucociliary transport was measured on the excised trachea.

RESULTS

Dapsone, 1 μg/mL, did not influence unstimulated (basal) IL-8 secretion. Apical LPS stimulation induced both apical and basolateral IL-8, but basolateral LPS increased only basolateral IL-8. Dapsone inhibited polarized IL-8 secretion from ALI-conditioned cells. Dapsone also decreased LPS-induced IL-8 mRNA level. LPS led to phosphorylation of extracellular signal-regulated kinase 1/2, but not p38 MAPK or c-Jun NH(2)-terminal kinase. LPS also induced NF-κB p65 phosphorylation, an effect that was inhibited by dapsone. Both oral and aerosol dapsone decreased LPS-induced intraepithelial neutrophil accumulation, but only treatment with aerosol dapsone restored mucociliary transport to normal.

CONCLUSIONS

Dapsone, given either systemically or as an aerosol, may be useful in treating neutrophilic airway inflammation.

Pathogenesis of airway inflammation in bronchial asthma

Bronchial asthma is a chronic disorder characterized by airway inflammation, reversible airway obstruction, and airway hyperresponsiveness. Eosinophils are believed to play important roles in the pathogenesis of asthma through the release of inflammatory mediators. In refractory eosinophilic asthma, anti-IL-5 mAb reduces exacerbations and steroid dose, indicating roles of eosinophils and IL-5 in the development of severe eosinophilic asthma. Even in the absence of IL-5, it is likely that the "Th2 network", including a cascade of vascular cell adhesion molecule-1/CC chemokines/GM-CSF, can sufficiently maintain eosinophilic infiltration and degranulation. Cysteinyl leukotrienes can also directly provoke eosinophilic infiltration and activation in the airways of asthma. Therefore, various mechanisms would be involved in the eosinophilic airway inflammation of asthma. In the pathogenesis of severe asthma, not only eosinophils but also mast cells or neutrophils play important roles. Mast cells are much infiltrated to smooth muscle in severe asthma and induce airway remodeling by release of inflammatory mediators such as amphiregulin. Treatment with anti-IgE Ab, which neutralizes circulating IgE and suppresses mast cell functions, reduces asthma exacerbations in severe asthmatic patients. Furthermore, infiltration of neutrophils in the airway is also increased in severe asthma. IL-8 plays an important role in the accumulation of neutrophils and is indeed upregulated in severe asthma. In the absence of chemoattractant for eosinophils, neutrophils stimulated by IL-8 augment the trans-basement membrane migration of eosinophils, suggesting that IL-8-stimulated neutrophils could lead eosinophils to accumulate in the airways of asthma. In view of these mechanisms, an effective strategy for controlling asthma, especially severe asthma, should be considered.

Airway epithelium mediates the anti-inflammatory effects of exercise on asthma

Airway epithelium plays an important role in the asthma physiopathology. Aerobic exercise decreases Th2 response in murine models of allergic asthma, but its effects on the structure and activation of airway epithelium in asthma are unknown. BALB/c mice were divided into control, aerobic exercise, ovalbumin-sensitized and ovalbumin-sensitized plus aerobic exercise groups. Ovalbumin sensitization occurred on days 0, 14, 28, 42, and aerosol challenge from day 21 to day 50. Aerobic exercise started on day 22 and ended on day 50. Total cells and eosinophils were reduced in ovalbumin-sensitized group submitted to aerobic exercise. Aerobic exercise also reduced the oxidative and nitrosative stress and the epithelial expression of Th2 cytokines, chemokines, adhesion molecules, growth factors and NF-kB and P2X7 receptor. Additionally, aerobic exercise increased the epithelial expression of IL-10 in non-sensitized and sensitized animals. These findings contribute to the understanding of the beneficial effects of aerobic exercise for chronic allergic airway inflammation, suggesting an immune-regulatory role of exercise on airway epithelium.

Effects of pharmacological and non-pharmacological interventions

BACKGROUND

Asthma is recognised as a condition with variable airway obstruction with pathophysiological features that include activation of a wide range of inflammatory and structural cells. Additionally, structural changes in the airways have been demonstrated. This includes increased thickening of components in the basement membrane region, increased smooth muscle mass, increased vascularisation and many other events that is often referred to as remodelling of the airways. These processes and the underlying mechanisms have attracted considerable attention.

METHODS AND RESULTS

This review describes the different interventive approaches that have been tried in order to improve asthma control and affect the underlying pathophysiological pathways. These include elimination of harmful environmental and occupational exposures, a wide range of pharmacological agents as well as bronchial thermoplasty. The existing evidence for effects on airway inflammation and airway remodelling is discussed in relationship to mechanistic aspects and short- and long-term outcome.

CONCLUSION

It is expected that modulation of the asthmatic airway remodelling will become an even more important endpoint in the near future.

Angiogenesis and lymphangiogenesis in bronchial asthma

Neovascularization plays a prominent role in inflammation and tissue remodeling in several chronic inflammatory disorders. Vessel number and size, vascular surface area and vascular leakage are all increased in biopsies from patients with asthma. High levels of VEGF and other angiogenic factors have been detected in tissues and biological samples of patients with asthma and correlate with disease activity and inversely with airway hyper-responsiveness. Inflammation in the lung stimulates the growth of new blood vessels and these contribute to the airway obstruction or airway hyper-responsiveness, or both. Effector cells of inflammation (human lung mast cells, basophils, eosinophils, macrophages, etc.) are major sources of a vast array of angiogenic and lymphangiogenic factors. Inhaled corticosteroids reduce vascularity and growth factor expression and might modulate bronchial vascular remodeling in asthma. Specific antagonists to VEGF and other angiogenic factors and their receptors might help to control chronic airway inflammation and vascular remodeling and offer a novel approach for the treatment of chronic inflammatory lung disorders.

Recent advances in pediatric asthma treatment

Although wheezing illness is at its most prevalent in infancy and early childhood, its self-limiting nature in the majority poses considerable challenges in offering a long-term prognosis and in initiating long-term prophylaxis. Many of the established treatments in adults have not been adequately assessed in children. Evidence is also emerging for a number of different wheezing syndromes, several of which do not to respond well to currently available medicines. Much research interest is being directed to underlying changes within the airway that appear to be independent of allergic mechanisms and that may lead to novel therapeutic approaches. The aim of this review is to restate and update current best-practice based on evidence, to encourage effective and safe use of asthma medication in children and to point to areas of ongoing research that are likely to influence management decisions in the near future.

Addition of long-acting beta2-agonists to inhaled corticosteroids versus same dose inhaled corticosteroids for chronic asthma in adults and children

BACKGROUND

Long-acting inhaled ss(2)-adrenergic agonists (LABAs) are recommended as 'add-on' medication to inhaled corticosteroids (ICS) in the maintenance therapy of asthmatic adults and children aged two years and above.

OBJECTIVES

To quantify in asthmatic patients the safety and efficacy of the addition of LABAs to ICS in patients insufficiently controlled on ICS alone.

SEARCH STRATEGY

We identified randomised controlled trials (RCTs) through electronic database searches (the Cochrane Airways Group Specialised Register, MEDLINE, EMBASE and CINAHL), bibliographies of RCTs and correspondence with manufacturers until May 2008.

SELECTION CRITERIA

We included RCTs if they compared the addition of inhaled LABAs versus placebo to the same dose of ICS in children aged two years and above and in adults.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed studies for methodological quality and extracted data. We obtained confirmation from the trialists when possible. The primary endpoint was the relative risk (RR) of asthma exacerbations requiring rescue oral corticosteroids. Secondary endpoints included pulmonary function tests (PFTs), rescue beta2-agonist use, symptoms, withdrawals and adverse events.

MAIN RESULTS

Seventy-seven studies met the entry criteria and randomised 21,248 participants (4625 children and 16,623 adults). Participants were generally symptomatic at baseline with moderate airway obstruction despite their current ICS regimen. Formoterol or salmeterol were most frequently added to low-dose ICS (200 to 400 microg/day of beclomethasone (BDP) or equivalent) in 49% of the studies. The addition of a daily LABA to ICS reduced the risk of exacerbations requiring oral steroids by 23% from 15% to 11% (RR 0.77, 95% CI 0.68 to 0.87, 28 studies, 6808 participants). The number needed to treat with the addition of LABA to prevent one use of rescue oral corticosteroids is 41 (29, 72), although the event rates in the ICS groups varied between 0% and 38%. Studies recruiting adults dominated the analysis (6203 adult participants versus 605 children). The subgroup estimate for paediatric studies was not statistically significant (RR 0.89, 95% CI 0.58 to 1.39) and includes the possibility of the superiority of ICS alone in children.Higher than usual dose of LABA was associated with significantly less benefit. The difference in the relative risk of serious adverse events with LABA was not statistically significant from that of ICS alone (RR 1.06, 95% CI 0.87 to 1.30). The addition of LABA led to a significantly greater improvement in FEV(1) (0.11 litres, 95% 0.09 to 0.13) and in the proportion of symptom-free days (11.88%, 95% CI 8.25 to 15.50) compared to ICS monotherapy. It was also associated with a reduction in the use of rescue short-acting ss(2)-agonists (-0.58 puffs/day, 95% CI -0.80 to -0.35), fewer withdrawals due to poor asthma control (RR 0.50, 95% CI 0.41 to 0.61), and fewer withdrawals due to any reason (RR 0.80, 95% CI 0.75 to 0.87). There was no statistically significant group difference in the risk of overall adverse effects (RR 1.00, 95% 0.97 to 1.04), withdrawals due to adverse health events (RR 1.04, 95% CI 0.86 to 1.26) or any of the specific adverse health events.

AUTHORS' CONCLUSIONS

In adults who are symptomatic on low to high doses of ICS monotherapy, the addition of a LABA at licensed doses reduces the rate of exacerbations requiring oral steroids, improves lung function and symptoms and modestly decreases use of rescue short-acting ss(2)-agonists. In children, the effects of this treatment option are much more uncertain. The absence of group difference in serious adverse health events and withdrawal rates in both groups provides some indirect evidence of the safety of LABAs at usual doses as add-on therapy to ICS in adults, although the width of the confidence interval precludes total reassurance.

Angiogenesis in asthma

Asthma is a chronic inflammatory disease of the airways characterized by infiltration and activation of inflammatory cells and by structural changes, including subepithelial fibrosis, smooth muscle cells hypertrophy/hyperplasia, epithelial cell metaplasia and angiogenesis. These structural changes are thought to correlate with asthma severity and to account for the development of progressive lung function deterioration. The mechanism underlying airway angiogenesis in asthma and its precise clinical relevance have not yet been completely elucidated. This review provides recent data showing the contribution of allergic inflammation in increased airway vascularity and potential therapeutical approaches in asthma treatment by acting on bronchial microvascular changes.

Addition of long-acting beta2-agonists to inhaled steroids versus higher dose inhaled steroids in adults and children with persistent asthma

BACKGROUND

In asthmatic patients inadequately controlled on inhaled corticosteroids and/or those with moderate persistent asthma, two main options are recommended: the combination of a long-acting inhaled ss2 agonist (LABA) with inhaled corticosteroids (ICS) or use of a higher dose of inhaled corticosteroids.

OBJECTIVES

To determine the effect of the combination of long-acting ss(2) agonists and inhaled corticosteroids compared to a higher dose of inhaled corticosteroids on the risk of asthma exacerbations, pulmonary function and on other measures of asthma control, and to look for characteristics associated with greater benefit for either treatment option.

SEARCH STRATEGY

We identified randomised controlled trials (RCTs) through electronic database searches (MEDLINE, EMBASE and CINAHL), bibliographies of RCTs, clinical trial registries and correspondence with manufacturers until May 2008.

SELECTION CRITERIA

RCTs that compared the combination of inhaled LABA and ICS to a higher dose of inhaled corticosteroids, in children and adults with asthma.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed methodological quality and extracted data. We obtained confirmation from the trialists when possible. The primary endpoint was the number of patients experiencing one or more asthma exacerbations requiring oral corticosteroids.

MAIN RESULTS

This review included 48 studies (15,155 participants including 1155 children and 14,000 adults). Participants were inadequately controlled on their current ICS regimen, experiencing ongoing symptoms and with generally moderate (FEV1 60% to 79% of predicted) airway obstruction. The studies tested the combination of salmeterol or formoterol with a median dose of 400 mcg/day of beclomethasone or equivalent (BDP-eq) compared to a median of 1000 mcg/day of BDP-eq, usually for 24 weeks or less. There was a statistically significantly lower risk of exacerbations requiring systemic corticosteroids in patients treated with LABA and ICS (RR 0.88, 95% CI 0.78 to 0.98, 27 studies, N = 10,578) from 11.45% to 10%, with a number needed to treat of 73 (median study duration: 12 weeks). The study results were dominated by adult studies; trial data from three paediatric studies showed a trend towards increased risk of rescue oral steroids (RR 1.24, 95% CI 0.58 to 2.66) and hospital admission (RR 2.21, 95% CI 0.74 to 6.64) associated with combination therapy. Overall, there was no statistically significant difference in the risk ratios for either hospital admission (RR 1.02, 95% CI 0.67 to 1.56) or serious adverse events (RR 1.12, 95% CI 0.91 to 1.37). The combination of LABA and ICS resulted in significantly greater but modest improvement from baseline in lung function, symptoms and rescue medication use than with higher ICS dose. Despite no significant group difference in the risk of overall adverse events (RR 0.99, 95% CI 0.95 to 1.03), there was an increase in the risk of tremor (RR 1.84, 95% CI 1.20 to 2.82) and a lower risk of oral thrush (RR 0.58, 95% CI 0.40 to 0.86)) in the LABA and ICS compared to the higher ICS group. There was no significant difference in hoarseness or headache between the treatment groups. The rate of withdrawals due to poor asthma control favoured the combination of LABA and ICS (RR 0.65, 95% CI 0.51 to 0.83).

AUTHORS' CONCLUSIONS

In adolescents and adults with sub-optimal control on low dose ICS monotherapy, the combination of LABA and ICS is modestly more effective in reducing the risk of exacerbations requiring oral corticosteroids than a higher dose of ICS. Combination therapy also led to modestly greater improvement in lung function, symptoms and use of rescue ss(2) agonists and to fewer withdrawals due to poor asthma control than with a higher dose of inhaled corticosteroids. Apart from an increased rate of tremor and less oral candidiasis with combination therapy, the two options appear relatively safe in adults although adverse effects associated with long-term ICS treatment were seldom monitored. In children, combination therapy did not lead to a significant reduction, but rather a trend towards an increased risk, of oral steroid-treated exacerbations and hospital admissions. These trends raised concern about the safety of combination therapy in view of modest improvement in children under the age of 12 years.

Eosinophil survival and apoptosis in health and disease

Eosinophilia is common feature of many disorders, including allergic diseases. There are many factors that influence the production, migration, survival and death of the eosinophil. Apoptosis is the most common form of physiological cell death and a necessary process to maintain but limit cell numbers in humans and other species. It has been directly demonstrated that eosinophil apoptosis is delayed in allergic inflammatory sites, and that this mechanism contributes to the expansion of eosinophil numbers within tissues. Among the proteins known to influence hematopoiesis and survival, expression of the cytokine interleukin-5 appears to be uniquely important and specific for eosinophils. In contrast, eosinophil death can result from withdrawal of survival factors, but also by activation of pro-apoptotic pathways via death factors. Recent observations suggest a role for cell surface death receptors and mitochondria in facilitating eosinophil apoptosis, although the mechanisms that trigger each of these death pathways remain incompletely delineated. Ultimately, the control of eosinophil apoptosis may someday become another therapeutic strategy for treating allergic diseases and other eosinophil-associated disorders.

Targeting abnormal airway vascularity as a therapeutical strategy in asthma

Asthma is a chronic inflammatory disease of airways, characterized by airway hyperresponsiveness and airflow limitation with acute bronchoconstriction, swelling of the airway wall, chronic mucus plug formation and airway wall remodelling. Functional and structural changes in the vasculature of asthmatic airways have been documented, and the signalling mechanisms are complex and have recently attracted much attention. The vascular changes may affect inflammatory cell recruitment, airway hyperresponsiveness and the regulation of airway calibre, and further, the level of disease control. Many critical factors are involved in the pathophysiological regulation of vascular changes in bronchial asthma, and the actions of these factors must be very carefully orchestrated. By better understanding the complicated actions of each factor, we may be able to advance further in asthma treatment.

Feasibility of a new method to collect exhaled breath condensate in pre-school children

Exhaled breath condensate (EBC) is a promising non-invasive method to assess respiratory inflammation in adults and children with lung disease. Especially in pre-school children, condensate collection is hampered by long sampling times because of open-ended collection systems. We aimed to assess the feasibility of condensate collection in pre-school children using a closed glass condenser with breath recirculation system, which also collects the residual non-condensed exhaled breath, and subsequently recirculates it back into the condenser. Condensate was collected before and after breath recirculation in 70 non-sedated pre-school children with and without recurrent wheeze. Cytokines (IL-4, IL-5, IL-6, IL-8, IL-10, IL-12p70, IL-13, TNF-α) were measured in 50 μl samples using ultrasensitive multiplexed liquid bead array. The success rate of condensate collection increased from 64% (without recirculation) to 83% (after breath recirculation), and mean condensate volume from 214 to 465 μl respectively. Detection of cytokines was successful in 95-100% of samples. Cytokine concentrations before and after breath recirculation were not different (p > 0.232). In asthmatic children, only TNF-α concentrations were significantly decreased, compared to non-asthmatics. In pre-school children, the collection of EBC is feasible using a new closed glass condenser with breath recirculation system. This new method may help to assess - non-invasively - cytokine profiles in asthmatic and non-asthmatic pre-school children.

Resin technologies: construction and staining of resin TMA's

The traditional formaldehyde-fixed paraffin-embedded tissue, and therefore the tissue microarrays created from it, provide good morphology but with a compromised antigenicity when compared to frozen tissue. In contrast, while solving the issue of antigenicity, frozen tissue suffers from a lack of morphology. We have demonstrated that tissue microarrays constructed in glycol methacrylate resin, when combined with a cold acetone fixation step, have been able to combine the superior morphology of resin-embedded sections with the superior antigenicity of frozen tissue for prospectively collected material.

Systemic and airway inflammation in sleep apnea and obesity: the role of ICAM-1 and IL-8

The recurrent hypoxic stress that characterizes obstructive sleep apnea (OSA) seems to play a role in the increased adherence of neutrophils to endothelial cells as well as in the resulting migration of the former to the inflamed area. Intercellular adhesion molecule 1 (ICAM-1) and interleukin (IL)-8 are markers widely used in OSA studies to investigate inflammation. The aim of this study was to measure ICAM-1 and IL-8 levels in the breath condensate and in the plasma and inflammatory cells in the induced sputum of 12 obese OSA (OO) patients, 10 nonobese OSA (NOO) patients, 10 obese non-OSA (ONO) subjects, and 8 healthy subjects (HS) using a specific enzyme immunoassay (EIA) kit. A significant increase in both plasma and exhaled IL-8 and ICAM concentrations and percentage neutrophils was observed in the induced sputum of obese OSA patients, non-obese OSA patients, and obese non-OSA subjects compared with healthy subjects. However, although these inflammatory markers were found to follow an upward trend in obese OSA patients no difference was observed in both either non-obese OSA patients and obese non-OSA subjects. Finally, a significant positive correlation was found to occur among IL-8, ICAM-1, and sputum neutrophils, as well as across the apnea-hypopnoea index (AHI), TST 90%, body mass index (BMI), and neck circumference. The data obtained confirm the occurrence of an ICAM- and IL-8-mediated neutrophilic airway inflammation in both OSA and obese patients. The degree of inflammation, which seems to worsen in cases of comorbidity (OSA and obesity), is likely to be responsible for the increased risk of developing cardiovascular events observed in these subjects, and therefore, it deserves to be elucidated even more.

Addition of inhaled long-acting beta2-agonists to inhaled steroids as first line therapy for persistent asthma in steroid-naive adults and children

BACKGROUND

Consensus statements recommend the addition of long-acting inhaled ss2-agonists (LABA) only in asthmatic patients who are inadequately controlled on inhaled corticosteroids (ICS). It is not uncommon for some patients to be commenced on ICS and LABA together as initial therapy.

OBJECTIVES

To compare the efficacy of combining inhaled corticosteroids with long-acting ss2-agonists (ICS+LABA) with inhaled corticosteroids alone (ICS alone) in steroid-naive children and adults with persistent asthma. We assessed two protocols: (1) LABA + ICS versus a similar dose of ICS (comparison 1) and (2) LABA + ICS versus a higher dose of ICS (comparison 2).

SEARCH STRATEGY

We identified randomised controlled trials through electronic database searches (May 2008).

SELECTION CRITERIA

Randomised trials comparing ICS + LABA with ICS alone in children and adults with asthma who had no inhaled corticosteroids in the preceding 28 days prior to enrolment.

DATA COLLECTION AND ANALYSIS

Each author assessed studies independently for risk of bias and extracted data. We obtained confirmation from the trialists when possible. The primary endpoint was rate of patients with one or more asthma exacerbations requiring rescue systemic corticosteroids. Results are expressed as relative risks (RR) for dichotomous data and as mean differences (MD) or standardised mean differences (SMD) for continuous data.

MAIN RESULTS

Twenty-eight study comparisons drawn from 27 trials (22 adult; five paediatric) met the review entry criteria (8050 participants). Baseline data from the studies indicated that trial populations had moderate or mild airway obstruction (FEV1>/=65% predicted), and that they were symptomatic prior to randomisation. In comparison 1, the combination of ICS and LABA was not associated with a significantly lower risk of patients with exacerbations requiring oral corticosteroids (RR 1.04; 95% confidence interval (CI) 0.73 to 1.47) or requiring hospital admissions (RR 0.38; 95% CI 0.09 to 1.65) compared to a similar dose of ICS alone. The combination of LABA and ICS led to a significantly greater improvement from baseline in FEV1 (0.12 L/sec; 95% CI 0.07 to 0.17), in symptoms (SMD -0.26; 95% CI -0.37 to -0.14) and in rescue ss2-agonist use (-0.41 puffs/day; 95% CI -0.73 to -0.09) compared with a similar dose of ICS alone. There was no significant group difference in the risk of serious adverse events (RR 1.15; 95% CI 0.64 to 2.09), any adverse events (RR 1.02; 95% CI 0.96 to 1.09), study withdrawals (RR 0.95; 95% CI 0.82 to 1.11), or withdrawals due to poor asthma control (RR 0.94; 95% CI 0.63 to 1.41).In comparison 2, the combination of LABA and ICS was associated with a higher risk of patients requiring oral corticosteroids (RR 1.24; 95% CI 1 to 1.53) and study withdrawal (RR 1.31; 95% CI 1.07 to 1.59) than a higher dose of ICS alone. For every 100 patients treated over 43 weeks, nine patients using a higher dose ICS compared to 11 (95% CI 9 to 14) on LABA and ICS suffered one or more exacerbations requiring rescue oral corticosteroids. There was a high level of statistical heterogeneity for FEV1 and morning peak flow. There was no statistically significant group difference in the risk of serious adverse events. Due to insufficient data we could not aggregate results for hospital admission, symptoms and other outcomes.

AUTHORS' CONCLUSIONS

In steroid-naive patients with mild to moderate airway obstruction, the combination of ICS and LABA does not significantly reduce the risk of patients with exacerbations requiring rescue oral corticosteroids over that achieved with a similar dose of ICS alone. However, it significantly improves lung function, reduces symptoms and marginally decreases rescue ss2-agonist use. Initiation of a higher dose of ICS is more effective at reducing the risk of exacerbations requiring rescue systemic corticosteroids, and of withdrawals, than combination therapy. Although children appeared to respond similarly to adults, no firm conclusions can be drawn regarding combination therapy in steroid-naive children, given the small number of children contributing data.

Blockade of airway inflammation and hyperresponsiveness by inhibition of BLT2, a low-affinity leukotriene B4 receptor

BLT2 is a low-affinity receptor for leukotriene B(4) (LTB(4)), a potent lipid mediator of inflammation generated from arachidonic acid via the 5-lipoxygenase pathway. Unlike BLT1, a high-affinity receptor for LTB(4), no clear physiological function has yet been identified for BLT2, especially with regard to the pathogenesis of asthma. The aim of this study was to investigate whether BLT2 plays a role in the pathogenesis of asthma. A murine model of allergic asthma was used to evaluate the role of BLT2 in ovalbumin-induced airway inflammation and airway hyperresponsiveness. The levels of BLT2 mRNA and its ligand, LTB(4), in the lung airway were highly elevated after ovalbumin challenge, and down-regulation of BLT2 with antisense BLT2 oligonucleotides markedly attenuated airway inflammation and airway hyperresponsiveness. Further analysis, aimed at identifying mediators downstream of BLT2, revealed that BLT2 activation led to elevation of reactive oxygen species and subsequent activation of NF-kappaB, thus inducing the expression of vascular cell adhesion molecule-1, which is known to be involved in eosinophil infiltration into the lung airway. Together, our results suggest that BLT2 plays a pivotal, mediatory role in the pathogenesis of asthma, acting through a "reactive oxygen species-NF-kappaB"-linked inflammatory signaling pathway.

Transcriptional regulation of cytokine function in airway smooth muscle cells

The immuno-modulatory properties of airway smooth muscle have become of increasing importance in our understanding of the mechanisms underlying chronic inflammation and structural remodeling of the airway wall in asthma and chronic obstructive pulmonary disease (COPD). ASM cells respond to many cytokines, growth factors and lipid mediators to produce a wide array of immuno-modulatory molecules which may in turn orchestrate and perpetuate the disease process in asthma and COPD. Despite numerous studies of the cellular effects of cytokines on cultured ASM, few have identified intracellular signaling pathways by which cytokines modulate or induce these cellular responses. In this review we provide an overview of the transcriptional mechanisms as well as intracellular signaling pathways regulating cytokine functions in ASM cells. The recent discovery of toll-like receptors in ASM cells represents a significant development in our understanding of the immuno-modulatory capabilities of ASM cells. Thus, we also review emerging evidence of the inflammatory response to toll-like receptor activation in ASM cells.

Granulocyte-macrophage colony-stimulating factor expression in induced sputum and bronchial mucosa in asthma and COPD

Background:

Granulocyte–macrophage colony-stimulating factor (GM-CSF) has been implicated as an important mediator in the pathogenesis of asthma and chronic obstructive pulmonary disease (COPD). However, the expression of GM-CSF and its receptor in airway samples in asthma and COPD across disease severity needs to be further defined.

Methods:

Sputum GM-CSF was measured in 18 control subjects, 45 subjects with asthma and 47 subjects with COPD. Enumeration of GM-CSF+ cells in the bronchial submucosa and airway smooth muscle bundle was performed in 29 control subjects, 36 subjects with asthma and 10 subjects with COPD.

Results:

The proportion of subjects with measurable GM-CSF in the sputum was raised in those with moderate (7/14) and severe (11/18) asthma, and in those with COPD GOLD (Global Initiative for Chronic Obstructive Lung Disease) stage II (7/16), III (8/17) and IV (7/14) compared with controls (1/18) and those with mild asthma (0/13); p = 0.001. The sputum GM-CSF concentration was correlated with the sputum eosinophilia in subjects with moderate to severe asthma (r_s = 0.41; p = 0.018). The median (interquartile range) GM-CSF+ and GM-CSFR+ cells/mm² of submucosa was increased in severe asthma (1.4 (3.0) and 2.1 (8.4)) compared with those with mild to moderate asthma (0 (2.5) and 1.1 (5)) and healthy controls (0 (0.5) and 0 (1.6)), (p = 0.004 and p = 0.02, respectively).

Conclusions:

The findings support a potential role for GM-CSF in asthma and COPD and suggest that overexpression of GM-CSF in sputum and the bronchial mucosa is a particular feature of severe asthma.

Anti-inflammatory effects of combined budesonide/formoterol in COPD exacerbations

Systemic corticosteroids and additional short-acting beta2-agonists are commonly used in exacerbations of chronic obstructive pulmonary disease (COPD). In this double-blind study, the combination of a high-dose inhaled corticosteroid with a rapid-onset long-acting beta2-agonist was evaluated in the treatment of out-patient COPD exacerbations. The primary aim was to compare 14-day treatment effects of budesonide/formoterol to placebo on sputum eosinophils and, secondarily, on other indices of inflammation, forced expiratory flow in one second (FEV(1)), symptoms, health status, and adverse events. Forty-five patients not using steroids (37 male, 21/24 current/ex smoker, median packyears 38, age 65 years, FEV(1) 61% predicted), experiencing a COPD exacerbation, were treated at home with budesonide/formoterol (320/9 microg 4 times daily), prednisolone (30 mg daily), or placebo for 14 days. Sputum eosinophils were significantly reduced by budesonide/formoterol (-57%) compared to placebo (+24%) (p = 0.01). Budesonide/formoterol reduced total symptom scores significantly (p = 0.01) compared to placebo. The increase in FEV(1) by 2 weeks of treatment with budesonide/formoterol (125 ml) was not significantly different from that of placebo (43 ml) (p = 0.07). Budesonide/ formoterol treatment did not suppress morning serum cortisol compared to placebo (-16%; p = 0.50). In conclusion, budesonide/formoterol reduces sputum eosinophils and improves symptoms in the treatment of out-patient COPD exacerbations.

The role of inhaled corticosteroids in the management of cystic fibrosis

The lung disease of cystic fibrosis (CF) is characterized by a vicious cycle of airway obstruction, chronic bacterial infection, and vigorous inflammation, which ultimately results in bronchiectasis. Recognition that excessive and persistent inflammation is a key factor in lung destruction has prompted investigation into anti-inflammatory therapies. Although effective, the use of systemic corticosteroids has been limited by the unacceptable adverse effect profile. Inhaled corticosteroids (ICS) are a widely prescribed anti-inflammatory agent in CF, likely as a result of clinicians' familiarity with these agents and their excellent safety profile at low doses in asthmatic patients. However, while multiple studies are limited by small sample size and short duration, they consistently failed to demonstrate statistically or clinically significant benefits of ICS use in CF. This review provides an overview of the inflammatory response in CF, the mechanisms of action of corticosteroids, the safety of ICS, and the literature relevant to the use of ICS in CF.

Interleukin-1beta mediates human airway epithelial cell migration via NF-kappaB

Migration of airway epithelial cells (AEC) is a necessary component of airway mucosal repair after injury. The cytokine IL-1beta, present in airway inflammation, has protean effects on constituent cells within the mucosa, but its effects on epithelial repair are not known. We examined migration in differentiated primary human AEC grown in air-liquid interface culture for up to 3 wk and in the 16HBE14o(-) cell line. Wounds were created by mechanical abrasion and followed to closure using digital microscopy. Concurrent treatment with IL-1beta (<or=10 ng/ml) significantly accelerated migration in primary differentiated cells and in the 16HBE14o(-) cell line but did not accelerate migration in primary differentiated AEC collected from asthmatic donors. IL-1beta treatment did not augment phosphorylation of stress-activated protein kinases normally activated by mechanical injury, such as heat shock protein 27, ERK1/2, and JNK, and did not elicit phosphorylation of signal transducer and activator of transcription-3. However, introduction of a silencing RNA to block expression of the p65 component of NF-kappaB blocked IL-1beta-accelerated migration substantially. Our data demonstrate that IL-1beta accelerates migration of normal, but not asthmatic, differentiated AEC by a mechanism that requires activation of the NF-kappaB signaling complex and suggests a trophic role for this cytokine in airway epithelial repair after injury.

Targeting the NF-kappaB pathway in asthma and chronic obstructive pulmonary disease

Asthma and chronic obstructive pulmonary disease are inflammatory lung disorders responsible for significant morbidity and mortality worldwide. While the importance of allergic responses in asthma is well known, respiratory viral and bacterial infections and pollutants especially cigarette smoke are important factors in the pathogenesis of both diseases. Corticosteroid treatment remains the first preference of treatment in either disease, however these therapies are not always completely effective, and are associated with side effects and steroid resistance. Due to such limitations, development of new treatments represents a major goal for both the pharmaceutical industry and academic researchers. There are now excellent reasons to promote NF-kappaB signalling intermediates and Rel family proteins as potential therapeutic targets for both asthma and chronic obstructive pulmonary disease. This notion is supported by the fact that much of the underlying inflammation of both diseases independent of stimuli, is mediated at least in part, by NF-kappaB mediated signalling events in several cell types. Also, a range of inhibitors of NF-kappaB signalling intermediates are now available, including DNA oligonucleotides and DNA-peptide molecules that act as NF-kappaB decoy sequences, small molecule inhibitors such as IKK-beta inhibitors, and proteasome inhibitors affecting NF-kappaB signalling, that have either shown promise in animal models or have begun clinical trials in other disorders. This review will focus on the role of NF-kappaB in both diseases, will discuss its suitability as a target, and will highlight recent key studies that support the potential of NF-kappaB as a therapeutic target in these two important inflammatory lung diseases.

Suppressed signal transduction in the bronchial epithelium of patients with systemic sclerosis

INTRODUCTION

Systemic sclerosis (SSc) is an autoimmune disorder, which frequently affects the lungs, with manifestations of interstitial lung disease (ILD) with lung fibrosis and of pulmonary hypertension. The pathogenesis remains largely unrecognised.

OBJECTIVE

The aim of this study was to elucidate the inflammation in the bronchial mucosa in patients with SSc.

SUBJECTS AND METHODS

Twenty-three subjects diagnosed with SSc participated. Twelve of the SSc patients showed signs of ILD, four were smokers and seven were treated with oral corticosteroids. Seventeen non-smoking, age- and sex-matched healthy subjects served as controls. Bronchoscopy was performed to sample endobronchial mucosal biopsies, which were immunohistochemically stained using a panel of antibodies against inflammatory markers.

RESULTS

The number of neutrophils was significantly elevated in the submucosa of SSc patients, regardless of ILD, or whether the subject was smoking or using oral corticosteroids. No up-regulation of neutrophil chemoattractants or cytokines was seen in the bronchial epithelium. The signal transduction pathways and adhesion molecule expression tended to be suppressed or unchanged in SSc patients compared with controls.

CONCLUSION

It is concluded that SSc is associated with a chronic neutrophilic inflammation in the bronchial mucosal, with signs of suppressed signal transduction, regardless of the presence of interstitial lung disease.

Glucocorticoids inhibit degranulation of mast cells in allergic asthma via nongenomic mechanism

BACKGROUND

Glucocorticoids (GCs) are the most potent anti-inflammatory agents available for allergic diseases including asthma, which are routinely believed to need several hours to take effect through regulating gene expression. Our previous report had shown that GCs could inhibit allergic asthma within 10 min, which the classical mechanism could not explain.

OBJECTIVE

To confirm the existence and verify the sites of GCs' rapid action, we investigated nongenomic effects of GCs on degranulation of mast cells in allergic asthma.

METHODS

The GCs' rapid action on airway mast cells deregulations was evaluated in the allergic asthma model of guinea pigs by the computer-assisted morphometry. Using whole-cell patch clamp and fluorometric assay, we examined GCs' nongenomic effect on IgE-mediated exocytosis and histamine release of rat basophilic leukaemia-2H3 mast cells. Employing the flash photolysis technique, we studied the role of Ca(2+) signal in the GCs' nongenomic effect.

RESULTS

Inhaled GCs significantly inhibited airway mast cells degranulation in the allergic asthma model of guinea pigs within 10 min. In vitro, GCs could rapidly inhibit IgE-mediated exocytosis and histamine release of mast cells, and neither GC nuclear receptor antagonist nor protein synthesis inhibitor could block the rapid action. We further demonstrated that GCs' nongenomic effect was not through direct action on secretory machinery, but was mediated by a reduction in the [Ca(2+)](i) elevation.

CONCLUSIONS

The study suggested for the first time that nongenomic pathway was involved in GCs' rapid inhibition on allergic asthma, and raised the possibility of new therapeutic strategies for allergic diseases including asthma.