Interaction between glucocorticoids and beta2 agonists on bronchial airway smooth muscle cells through synchronised cellular signalling

Molecular pathways underlying sympathetic autonomic overshooting leading to fear and traumatic memories: looking for alternative therapeutic options for post-traumatic stress disorder

The sympathoadrenal medullary system and the hypothalamic-pituitary-adrenal axis are both activated upon stressful events. The release of catecholamines, such as dopamine, norepinephrine (NE), and epinephrine (EPI), from sympathetic autonomic nerves participate in the adaptive responses to acute stress. Most theories suggest that activation of peripheral β-adrenoceptors (β-ARs) mediates catecholamines-induced memory enhancement. These include direct activation of β-ARs in the vagus nerve, as well as indirect responses to catecholamine-induced glucose changes in the brain. Excessive sympathetic activity is deeply associated with memories experienced during strong emotional stressful conditions, with catecholamines playing relevant roles in fear and traumatic memories consolidation. Recent findings suggest that EPI is implicated in fear and traumatic contextual memories associated with post-traumatic stress disorder (PTSD) by increasing hippocampal gene transcription (e.g., Nr4a) downstream to cAMP response-element protein activation (CREB). Herein, we reviewed the literature focusing on the molecular mechanisms underlying the pathophysiology of memories associated with fear and traumatic experiences to pave new avenues for the treatment of stress and anxiety conditions, such as PTSD.

Neural Mechanisms Underlying the Coughing Reflex

Breathing is an intrinsic natural behavior and physiological process that maintains life. The rhythmic exchange of gases regulates the delicate balance of chemical constituents within an organism throughout its lifespan. However, chronic airway diseases, including asthma and chronic obstructive pulmonary disease, affect millions of people worldwide. Pathological airway conditions can disrupt respiration, causing asphyxia, cardiac arrest, and potential death. The innervation of the respiratory tract and the action of the immune system confer robust airway surveillance and protection against environmental irritants and pathogens. However, aberrant activation of the immune system or sensitization of the nervous system can contribute to the development of autoimmune airway disorders. Transient receptor potential ion channels and voltage-gated Na+ channels play critical roles in sensing noxious stimuli within the respiratory tract and interacting with the immune system to generate neurogenic inflammation and airway hypersensitivity. Although recent studies have revealed the involvement of nociceptor neurons in airway diseases, the further neural circuitry underlying airway protection remains elusive. Unraveling the mechanism underpinning neural circuit regulation in the airway may provide precise therapeutic strategies and valuable insights into the management of airway diseases.

Glucocorticoid Insensitivity in Asthma: The Unique Role for Airway Smooth Muscle Cells

Although most patients with asthma symptoms are well controlled by inhaled glucocorticoids (GCs), a subgroup of patients suffering from severe asthma respond poorly to GC therapy. Such GC insensitivity (GCI) represents a profound challenge in managing patients with asthma. Even though GCI in patients with severe asthma has been investigated by several groups using immune cells (peripheral blood mononuclear cells and alveolar macrophages), uncertainty exists regarding the underlying molecular mechanisms in non-immune cells, such as airway smooth cells (ASM) cells. In asthma, ASM cells are among the targets of GC therapy and have emerged as key contributors not only to bronchoconstriction but also to airway inflammation and remodeling, as implied by experimental and clinical evidence. We here summarize the current understanding of the actions/signaling of GCs in asthma, and specifically, GC receptor (GR) “site-specific phosphorylation” and its role in regulating GC actions. We also review some common pitfalls associated with studies investigating GCI and the inflammatory mediators linked to asthma severity. Finally, we discuss and contrast potential molecular mechanisms underlying the impairment of GC actions in immune cells versus non-immune cells such as ASM cells.

State-of-the-art beta-adrenoreceptor agonists for the treatment of asthma

INTRODUCTION

Asthma, a heterogeneous disease, is characterized by chronic airway inflammation and hyperreactivity. β₂-adrenoreceptor agonists (β₂-agonists) remain pivotal for asthma management. Short-acting β₂-agonists (SABAs) result in rapid symptomatic alleviation and bronchospasm prevention. Patients experience significant clinical benefits from therapy with long-acting β₂-agonists (LABAs) with efficacy to bronchodilate, and prolonged lung function betterment. Recently discovered β₂-agonists with longer half-lives offer once-daily dosing.

AREAS COVERED

The authors provide a thorough review of the pharmacokinetics, pharmacodynamics, efficacy, tolerability, classification, and safety of β₂-agonists through an in-depth review of current literature using these databases: U.S. National Institutes of Health's National Library of Medicine (NIH/NLM), PubMed Central, and NLM clinical trials.

EXPERT OPINION

β₂- agonists act primarily on airway smooth muscle cells and are quintessential for adequate asthma management. Given their pharmacodynamic and pharmacokinetic properties, SABAs are used as rescue medication. Notably, the current Global Initiative for Asthma (GINA) strategy document recommends using LABA/inhaled corticosteroid combinations both as a daily controller and as a rescue medication. Clinicians should assess this new treatment plan on a per-case basis, making sure to evaluate inhaler adherence and treat modifiable risk factors. The development of next-generation β₂- agonists is an exciting research area that could significantly improve patients' adherence to treatment regimens and, consequently, asthma control and quality of life.

Bronchial thermoplasty in asthma: an exploratory histopathological evaluation in distinct asthma endotypes/phenotypes

Background

Bronchial thermoplasty regulates structural abnormalities involved in airway narrowing in asthma. In the present study we aimed to investigate the effect of bronchial thermoplasty on histopathological bronchial structures in distinct asthma endotypes/phenotypes.

Methods

Endobronchial biopsies (n = 450) were collected from 30 patients with severe uncontrolled asthma before bronchial thermoplasty and after 3 sequential bronchial thermoplasties. Patients were classified based on blood eosinophils, atopy, allergy and smoke exposure. Tissue sections were assessed for histopathological parameters and expression of heat-shock proteins and glucocorticoid receptor. Proliferating cells were determined by Ki67-staining.

Results

In all patients, bronchial thermoplasty improved asthma control (p < 0.001), reduced airway smooth muscle (p = 0.014) and increased proliferative (Ki67 +) epithelial cells (p = 0.014). After bronchial thermoplasty, airway smooth muscle decreased predominantly in patients with T2 high asthma endotype. Epithelial cell proliferation was increased after bronchial thermoplasty in patients with low blood eosinophils (p = 0.016), patients with no allergy (p = 0.028) and patients without smoke exposure (p = 0.034).

In all patients, bronchial thermoplasty increased the expression of glucocorticoid receptor in epithelial cells (p = 0.018) and subepithelial mesenchymal cells (p = 0.033) and the translocation of glucocorticoid receptor in the nucleus (p = 0.036). Furthermore, bronchial thermoplasty increased the expression of heat shock protein-70 (p = 0.002) and heat shock protein-90 (p = 0.001) in epithelial cells and decreased the expression of heat shock protein-70 (p = 0.009) and heat shock protein-90 (p = 0.002) in subepithelial mesenchymal cells. The effect of bronchial thermoplasty on the expression of heat shock proteins -70 and -90 was distinctive across different asthma endotypes/phenotypes.

Conclusions

Bronchial thermoplasty leads to a diminishment of airway smooth muscle, to epithelial cell regeneration, increased expression and activation of glucocorticoid receptor in the airways and increased expression of heat shock proteins in the epithelium. Histopathological effects appear to be distinct in different endotypes/phenotypes indicating that the beneficial effects of bronchial thermoplasty are achieved by diverse molecular targets associated with asthma endotypes/phenotypes.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12931-021-01774-0.

Important lessons learned from studies on the pharmacology of glucocorticoids in human airway smooth muscle cells: Too much of a good thing may be a problem

Glucocorticoids (GCs) are the treatment of choice for chronic inflammatory diseases such as asthma. Despite proven effective anti-inflammatory and immunosuppressive effects, long-term and/or systemic use of GCs can potentially induce adverse effects. Strikingly, some recent experimental evidence suggests that GCs may even exacerbate some disease outcomes. In asthma, airway smooth muscle (ASM) cells are among the targets of GC therapy and have emerged as key contributors not only to bronchoconstriction, but also to airway inflammation and remodeling, as implied by experimental and clinical evidence. We here will review the beneficial effects of GCs on ASM cells, emphasizing the differential nature of GC effects on pro-inflammatory genes and on other features associated with asthma pathogenesis. We will also summarize evidence describing how GCs can potentially promote pro-inflammatory and remodeling features in asthma with a specific focus on ASM cells. Finally, some of the possible solutions to overcome these unanticipated effects of GCs will be discussed.

Benefit:Risk Profile of Budesonide in Obstructive Airways Disease

Airway inflammation is a major contributing factor in both asthma and chronic obstructive pulmonary disease (COPD) and represents an important target for treatment. Inhaled corticosteroids (ICS) as monotherapy or in combination therapy with long-acting β₂-agonists or long-acting muscarinic antagonists are used extensively in the treatment of asthma and COPD. The development of ICS for their anti-inflammatory properties progressed through efforts to increase topical potency and minimise systemic potency and through advances in inhaled delivery technology. Budesonide is a potent, non-halogenated ICS that was developed in the early 1970s and is now one of the most widely used lung medicines worldwide. Inhaled budesonide's physiochemical and pharmacokinetic/pharmacodynamic properties allow it to reach a rapid and high airway efficacy due to its more balanced relationship between water solubility and lipophilicity. When absorbed from the airways and lung tissue, its moderate lipophilicity shortens systemic exposure, and its unique property of intracellular esterification acts like a sustained release mechanism within airway tissues, contributing to its airway selectivity and a low risk of adverse events. There is a large volume of clinical evidence supporting the efficacy and safety of budesonide, both alone and in combination with the fast- and long-acting β₂-agonist formoterol, as maintenance therapy in patients with asthma and with COPD. The combination of budesonide/formoterol can also be used as an as-needed reliever with anti-inflammatory properties, with or without regular maintenance for asthma, a novel approach that is already approved by some country-specific regulatory authorities and currently recommended in the Global Initiative for Asthma (GINA) guidelines. Budesonide remains one of the most well-established and versatile of the inhaled anti-inflammatory drugs. This narrative review provides a clinical reappraisal of the benefit:risk profile of budesonide in the management of asthma and COPD.

Recent Advances in Drug Repurposing for Parkinson's Disease

As a long-term degenerative disorder of the central nervous system that mostly affects older people, Parkinson's disease is a growing health threat to our ever-aging population. Despite remarkable advances in our understanding of this disease, all therapeutics currently available only act to improve symptoms but cannot stop the disease progression. Therefore, it is essential that more effective drug discovery methods and approaches are developed, validated, and used for the discovery of disease-modifying treatments for Parkinson's disease. Drug repurposing, also known as drug repositioning, or the process of finding new uses for existing or abandoned pharmaceuticals, has been recognized as a cost-effective and timeefficient way to develop new drugs, being equally promising as de novo drug discovery in the field of neurodegeneration and, more specifically for Parkinson's disease. The availability of several established libraries of clinical drugs and fast evolvement in disease biology, genomics and bioinformatics has stimulated the momentums of both in silico and activity-based drug repurposing. With the successful clinical introduction of several repurposed drugs for Parkinson's disease, drug repurposing has now become a robust alternative approach to the discovery and development of novel drugs for this disease. In this review, recent advances in drug repurposing for Parkinson's disease will be discussed.

Effects of cigarette smoke on barrier function and tight junction proteins in the bronchial epithelium: protective role of cathelicidin LL-37

Background

Airway epithelial barrier function is maintained by the formation of tight junctions (TJs) and adherens junctions (AJs). Inhalation of cigarette smoke causes airway epithelial barrier dysfunction and may contribute to the pathogenesis of chronic lung diseases such as asthma and chronic obstructive pulmonary disease (COPD). We assessed the effects of cigarette smoke on barrier function and expression of multiple TJ and AJ proteins in the bronchial epithelium. We also examined whether treatment with glucocorticosteroids (GCSs), long-acting β₂-agonists (LABAs), and human cathelicidin LL-37 can protect against cigarette smoke extract (CSE)-induced barrier dysfunction.

Methods

Calu-3 cells cultured at the air-liquid interface were pretreated with or without GCSs, LABAs, GCSs plus LABAs, or LL-37, and subsequently exposed to CSE. Barrier function was assessed by transepithelial electronic resistance (TEER) measurements. Gene and protein expression levels of TJ and AJ proteins were analyzed by quantitative PCR and western blotting, respectively. Immunofluorescence staining of TJ and AJ proteins was performed.

Results

CSE decreased TEER and increased permeability in a concentration-dependent manner. CSE suppressed gene expression of claudin-1, claudin-3, claudin-4, claudin-7, claudin-15, occludin, E-cadherin, junctional adhesion molecule-A (JAM-A) and zonula occludens-1 (ZO-1) within 12 h post-CSE exposure, while suppressed protein expression levels of occludin at 12 h. CSE-treated cells exhibited discontinuous or attenuated immunostaining for claudin-1, claudin-3, claudin-4, occludin, ZO-1, and E-cadherin compared with untreated cells. GCS treatment partially restored CSE-induced TEER reduction, while LABA treatment had no effect. GCS and LABA combination treatment had no additive effect on CSE-induced TEER reduction and gene suppression of TJ and AJ proteins. Human cathelicidin LL-37 counteracted CSE-induced TEER reduction and prevented disruption of occludin and ZO-1. LL-37 also attenuated CSE-induced decreases in gene and protein expression levels of occludin.

Conclusions

CSE caused airway epithelial barrier dysfunction and simultaneously downregulated multiple TJ and AJ proteins. GCS and LABA combination treatment had no additive effect on CSE-induced TEER reduction. LL-37 counteracted CSE-induced TEER reduction and prevented disruption of occludin and ZO-1. Use of LL-37 to counteract airway epithelial barrier dysfunction may have significant benefits for respiratory diseases such as asthma and COPD.

Beta2-adrenergic receptor in kidney biology: A current prospective

Beta2-adrenergic receptor (β₂ -AR) is a G-protein-coupled adrenergic receptor family member, whose clinical significance has been extensively investigated in lung, cardiovascular and muscular diseases, but its role in kidney biology remains understudied. In this review, we discuss some of the recent studies, where the effect of agonist/antagonist-mediated activation/inhibition of β₂ -AR on disease pathogenesis process was studied, and highlighted the role of β₂ -AR in kidney biology. The expression of β₂ -AR has been noted in many kidney subunits including proximal tubules, glomeruli and podocytes. In vivo studies have shown that in cultured proximal tubules β₂ -AR is involved in Na-ATPase activity and transcellular Na-transport through protein kinase-C activation; whereas in cultured podocytes, it was associated with depolarization of the membrane. The animal studies further revealed that β₂ -AR activation by short-acting β₂ agonists attenuated monocyte activation, pro-inflammatory and pro-fibrotic responses through β-arrestin2 dependent NF-kB inactivation in diabetic kidney disease; in contrast, activation by long-acting β₂ agonists restored mitochondrial and renal function in the acute kidney injury mice models through PGC-1α dependent mitochondrial biogenesis. In conclusion, the activation of β₂ -AR may present a rapidly developing therapeutic target for renal diseases.

Long acting β2-agonist's activation of cyclic AMP cannot halt ongoing mitogenic stimulation in airway smooth muscle cells

Airway smooth muscle cell (ASMC) hyperplasia causes airway wall remodelling, which is resisting to therapy. Long acting β2-agonists (LABA) relax airway muscles, but their effect on remodelling is unclear. This study compared the anti-proliferative effect of LABA in human primary ASMC, in situations where LABA were applied before, together, or after platelet derived growth factor (PDGF-BB). Cells obtained from controls (n = 5), and asthma patients (n = 5) were stimulated by PDGF-BB (10 ng/ml) before or after the application of formoterol or salmeterol. Proliferation was determined by direct cell counts over three days, cell cycle control proteins p21^(Waf1/Cip1), p27^(Kip1), signalling proteins Erk1/2 and p38 mitogen activated protein kinase (MAPK) were detected by immuno-blotting. PDGF-BB induced proliferation was significantly stronger in asthmatic ASMC versus controls. Proliferation was prevented by 30 min pre-incubation with LABA. When LABA were applied together or after PDGF-BB, their anti-proliferative effect was no longer significant. In untreated ASMC, LABA increased the expression of p21^(Waf1/Cip1) and p27^(Kip1) through cAMP, and this mechanism was abolished by the presence of PDGF-BB. The data show that the anti-proliferative effect of cAMP signalling cannot overcome the mitogenic signalling cascade once it was activated. Therefore, remodelling in asthma cannot be reduced by LABA.

Mechanism of anti-remodelling action of treprostinil in human pulmonary arterial smooth muscle cells

Treprostinil is applied for pulmonary arterial hypertension (PAH) therapy. However, the mechanism by which the drug achieves its beneficial effects in PAH vessels is not fully understood. This study investigated the effects of treprostinil on PDGF-BB induced remodelling parameters in isolated human pulmonary arterial smooth muscle cells (PASMC) of four PAH patients. The production of TGF-β1, CTGF, collagen type-I and -IV, and of fibronectin were determined by ELISA and PCR. The role of cAMP was determined by ELISA and di-deoxyadenosine treatment. Proliferation was determined by direct cell count. Treprostinil increased cAMP levels dose and time dependently, which was not affected by PDGF-BB. Treprostinil significantly reduced PDGF-BB induced secretion of TGF-β1 and CTGF, both was counteracted when cAMP generation was blocked. Similarly, the PDGF-BB induced proliferation of PASMC was dose dependently reduced by treprostinil through signalling via cAMP—C/EBP-α p42 –p21^(WAf1/Cip1). In regards to extracellular matrix remodelling, treprostinil significantly reduced PDGF-BB—TGF-β1—CTGF induced synthesis and deposition of collagen type I and fibronectin, in a cAMP sensitive manner. In contrast, the deposition of collagen IV was not affected. The data suggest that this action of treprostinil in vessel wall remodelling may benefit patients with PAH and may reduce arterial wall remodelling.

Long-Acting β2-Adrenoceptor Agonists Enhance Glucocorticoid Receptor (GR)-Mediated Transcription by Gene-Specific Mechanisms Rather Than Generic Effects via GR

In asthma, the clinical efficacy of inhaled corticosteroids (ICSs) is enhanced by long-acting β₂-adrenoceptor agonists (LABAs). ICSs, or more accurately, glucocorticoids, promote therapeutically relevant changes in gene expression, and, in primary human bronchial epithelial cells (pHBECs) and airway smooth muscle cells, this genomic effect can be enhanced by a LABA. Modeling this interaction in human bronchial airway epithelial BEAS-2B cells transfected with a 2× glucocorticoid response element (2×GRE)-driven luciferase reporter showed glucocorticoid-induced transcription to be enhanced 2- to 3-fold by LABA. This glucocorticoid receptor (GR; NR3C1)-dependent effect occurred rapidly, was insensitive to protein synthesis inhibition, and was maximal when glucocorticoid and LABA were added concurrently. The ability of LABA to enhance GR-mediated transcription was not associated with changes in GR expression, serine (Ser²⁰³, Ser²¹¹, Ser²²⁶) phosphorylation, ligand affinity, or nuclear translocation. Chromatin immunoprecipitation demonstrated that glucocorticoid-induced recruitment of GR to the integrated 2×GRE reporter and multiple gene loci, whose mRNAs were unaffected or enhanced by LABA, was also unchanged by LABA. Transcriptomic analysis revealed glucocorticoid-induced mRNAs were variably enhanced, unaffected, or repressed by LABA. Thus, events leading to GR binding at target genes are not the primary explanation for how LABAs modulate GR-mediated transcription. As many glucocorticoid-induced genes are independently induced by LABA, gene-specific control by GR- and LABA-activated transcription factors may explain these observations. Because LABAs promote similar effects in pHBECs, therapeutic relevance is likely. These data illustrate the need to understand gene function(s), and the mechanisms leading to gene-specific induction, if existing ICS/LABA combination therapies are to be improved.

The beclomethasone anti-inflammatory effect occurs in cell/mediator-dependent manner and is additively enhanced by formoterol: NFkB, p38, PKA analysis

AIMS

Beclomethasone/formoterol (BDP/FOR) has been reported to be more effective than its separate components in airway disease control and in airway inflammation improvement. However, BDP/FOR effects on cytokine-induced inflammation in structural cells have not been described and whether these effects occur in a cell- and mediator-dependent manner has not been fully elucidated. We sought to evaluate BDP and/or FOR effects on endothelial ICAM-1, E-selectin, IL-8 and on bronchial epithelial ICAM-1 and IL-8. Specific intracellular signaling pathways were also investigated.

MATERIALS AND METHODS

Surface adhesion molecule expression and IL-8 release induced by TNF-alpha were measured by ELISA. Intracellular signaling pathways were investigated by a) EMSA and Western blot analysis to evaluate NF-κB DNA-binding and MAPK-p38 phosphorylation; b) PDTC/SB203580 as NF-κB/p38 inhibitors; c) forskolin/H-89 as PKA activator/inhibitor.

KEY FINDINGS

BDP/FOR additively reduced endothelial E-selectin and IL-8 as well as bronchial epithelial ICAM-1 and IL-8. BDP/FOR and SB203580 showed the highest inhibitory effect on epithelial IL-8, whereas endothelial ICAM-1 was never affected by BDP/FOR and PDTC. TNF-alpha-induced NF-κB DNA-binding and MAPK-p38 phosphorylation were not influenced by BDP/FOR. Forskolin mimicked FOR effects; H-89 partially reversed the BDP/FOR inhibition in a mediator-dependent manner.

SIGNIFICANCE

The BDP/FOR inhibition degree was related to the inflammatory mediator- and cell-type considered. FOR additively enhanced BDP effects by partially involving both dependent- and independent-PKA mechanisms. Our results might contribute to highlight the strong relationship between specific molecular pathways and different sensitivity to the corticosteroid/β2-agonist effects and to clarify the molecular mechanisms underlying the BDP/FOR anti-inflammatory activity in vivo.

Large-scale profiling of signalling pathways reveals an asthma specific signature in bronchial smooth muscle cells

Background

Bronchial smooth muscle (BSM) cells from asthmatic patients maintain in vitro a distinct hyper-reactive (“primed”) phenotype, characterized by increased release of pro-inflammatory factors and mediators, as well as hyperplasia and/or hypertrophy. This “primed” phenotype helps to understand pathogenesis of asthma, as changes in BSM function are essential for manifestation of allergic and inflammatory responses and airway wall remodelling.

Objective

To identify signalling pathways in cultured primary BSMs of asthma patients and non-asthmatic subjects by genome wide profiling of differentially expressed mRNAs and activated intracellular signalling pathways (ISPs).

Methods

Transcriptome profiling by cap-analysis-of-gene-expression (CAGE), which permits selection of preferentially capped mRNAs most likely to be translated into proteins, was performed in human BSM cells from asthmatic (n=8) and non-asthmatic (n=6) subjects and OncoFinder tool were then exploited for identification of ISP deregulations.

Results

CAGE revealed >600 RNAs differentially expressed in asthma vs control cells (p≤0.005), with asthma samples showing a high degree of similarity among them. Comprehensive ISP activation analysis revealed that among 269 pathways analysed, 145 (p<0.05) or 103 (p<0.01) are differentially active in asthma, with profiles that clearly characterize BSM cells of asthmatic individuals. Notably, we identified 7 clusters of coherently acting pathways functionally related to the disease, with ISPs down-regulated in asthma mostly targeting cell death-promoting pathways and up-regulated ones affecting cell growth and proliferation, inflammatory response, control of smooth muscle contraction and hypoxia-related signalization.

Conclusions

These first-time results can now be exploited toward development of novel therapeutic strategies targeting ISP signatures linked to asthma pathophysiology.

Reduced suppressive effect of β2-adrenoceptor agonist on fibrocyte function in severe asthma

Background

Patients with severe asthma have increased airway remodelling and elevated numbers of circulating fibrocytes with enhanced myofibroblastic differentiation capacity, despite being treated with high doses of corticosteroids, and long acting β₂-adrenergic receptor (AR) agonists (LABAs). We determined the effect of β₂-AR agonists, alone or in combination with corticosteroids, on fibrocyte function.

Methods

Non-adherent non-T cells from peripheral blood mononuclear cells isolated from healthy subjects and patients with non-severe or severe asthma were treated with the β₂-AR agonist, salmeterol, in the presence or absence of the corticosteroid dexamethasone. The number of fibrocytes (collagen I⁺/CD45⁺ cells) and differentiating fibrocytes (α-smooth muscle actin⁺ cells), and the expression of CC chemokine receptor 7 and of β₂-AR were determined using flow cytometry. The role of cyclic adenosine monophosphate (cAMP) was elucidated using the cAMP analogue 8-bromoadenosine 3′,5′-cyclic monophosphate (8-Br-cAMP) and the phosphodiesterase type IV (PDE4) inhibitor, rolipram.

Results

Salmeterol reduced the proliferation, myofibroblastic differentiation and CCR7 expression of fibrocytes from healthy subjects and non-severe asthma patients. Fibrocytes from severe asthma patients had a lower baseline surface β₂-AR expression and were relatively insensitive to salmeterol but not to 8-Br-cAMP or rolipram. Dexamethasone increased β₂-AR expression and enhanced the inhibitory effect of salmeterol on severe asthma fibrocyte differentiation.

Conclusions

Fibrocytes from patients with severe asthma are relatively insensitive to the inhibitory effects of salmeterol, an effect which is reversed by combination with corticosteroids.

Electronic supplementary material

The online version of this article (10.1186/s12931-017-0678-7) contains supplementary material, which is available to authorized users.

Glucocorticosteroids

Glucocorticosteroids are the most effective anti-inflammatory therapy for asthma but are relatively ineffective in COPD. Glucocorticoids are broad-spectrum anti-inflammatory drugs that suppress inflammation via several molecular mechanisms. Glucocorticoids suppress the multiple inflammatory genes that are activated in asthma by reversing histone acetylation of activated inflammatory genes through binding of ligand-bound glucocorticoid receptors (GR) to coactivator molecules and recruitment of histone deacetylase-2 (HDAC2) to the activated inflammatory gene transcription complex (trans-repression). At higher concentrations of glucocorticoids GR homodimers interact with DNA recognition sites to activate transcription through increased histone acetylation of anti-inflammatory genes and transcription of several genes linked to glucocorticoid side effects (trans-activation). Glucocorticoids also have post-transcriptional effects and decrease stability of some proinflammatory mRNAs. Decreased glucocorticoid responsiveness is found in patients with severe asthma and asthmatics who smoke, as well as in all patients with COPD. Several molecular mechanisms of glucocorticoid resistance have now been identified which involve phosphorylation and other post-translational modifications of GR. HDAC2 is markedly reduced in activity and expression as a result of oxidative/nitrative stress and pi3 kinase-δ inhibition, so that inflammation is resistant to the anti-inflammatory actions of glucocorticoids. Dissociated glucocorticoids and selective GR modulators which show improved trans-repression over trans-activation effects have been developed to reduce side effects, but so far it has been difficult to dissociate anti-inflammatory effects from adverse effects. In patients with glucocorticoid resistance alternative anti-inflammatory treatments are being investigated as well as drugs that may reverse the molecular mechanisms of glucocorticoid resistance.

Fluticasone/salmeterol reduces remodelling and neutrophilic inflammation in severe equine asthma

Asthmatic airways are inflamed and undergo remodelling. Inhaled corticosteroids and long-acting β2-agonist combinations are more effective than inhaled corticosteroid monotherapy in controlling disease exacerbations, but their effect on airway remodelling and inflammation remains ill-defined. This study evaluates the contribution of inhaled fluticasone and salmeterol, alone or combined, to the reversal of bronchial remodelling and inflammation. Severely asthmatic horses (6 horses/group) were treated with fluticasone, salmeterol, fluticasone/salmeterol, or with antigen avoidance for 12 weeks. Lung function, central and peripheral airway remodelling, and bronchoalveolar inflammation were assessed. Fluticasone/salmeterol and fluticasone monotherapy decreased peripheral airway smooth muscle remodelling after 12 weeks (p = 0.007 and p = 0.02, respectively). On average, a 30% decrease was observed with both treatments. In central airways, fluticasone/salmeterol reversed extracellular matrix remodelling after 12 weeks, both within the lamina propria (decreased thickness, p = 0.005) and within the smooth muscle layer (p = 0.004). Only fluticasone/salmeterol decreased bronchoalveolar neutrophilia (p = 0.03) to the same extent as antigen avoidance already after 8 weeks. In conclusion, this study shows that fluticasone/salmeterol combination decreases extracellular matrix remodelling in central airways and intraluminal neutrophilia. Fluticasone/salmeterol and fluticasone monotherapy equally reverse peripheral airway smooth muscle remodelling.

Systematic Review and Meta-Analysis of the Efficacy and Safety of Combined Epinephrine and Corticosteroid Therapy for Acute Bronchiolitis in Infants

Objective: To evaluate the effectiveness of combined epinephrine and corticosteroid therapy for acute bronchiolitis in infants.

Methods: Four electronic databases (MEDLINE, EMBASE, CINAHL, and CENTRAL) were searched from their inception to February 28, 2017 for studies involving infants aged less than 24 months with bronchiolitis which assessed the use of epinephrine and corticosteroid combination therapy. The methodological quality of the included studies was assessed using the Cochrane Collaboration's Risk of Bias Tool. A random-effects meta-analysis was used to pool the effect estimates. The primary outcomes were hospital admission rate and length of hospital stay.

Results: Of 1,489 citations identified, 5 randomized controlled trials involving 1,157 patients were included. All studies were of high quality and low risk of bias. Results of the meta-analysis showed no significant differences in the primary outcomes. Hospitalization rate was reduced by combinatorial therapy of epinephrine and corticosteroid in only one out of five studies, whereas pooled data indicated no benefit over epinephrine plus placebo. Clinical severity scores were significantly improved in all five RCTs when assessed individually, but no benefit was observed compared to epinephrine monotherapy when the data were pooled together. Pooled data showed that combination therapy was more effective at improving oxygen saturation level (mean difference: −0.70; 95% confidence interval: −1.17 to −0.22, p = 0.004). There was no difference in the risk of serious adverse events in infants treated with the combined epinephrine and corticosteroid therapy.

Conclusions: Combination treatment of epinephrine and dexamethasone was ineffective in reducing hospital admission and length of stay among infants with bronchiolitis.

[Fixed-dose combination fluticasone propionate/formoterol for the treatment of asthma: a review of its pharmacology, efficacy and tolerability]

The fixed-dose combination fluticasone propionate/formoterol (FPF) is a novel combination of a widely known and used inhaled glucocorticoid (IGC) and a long-acting β2-adrenergic agonist (LABA), available for the first time in a single device. This fixed-dose combination of FPF has a demonstrated efficacy and safety profile in clinical trials compared with its individual components and other fixed-dose combinations of IGC/LABA and is indicated for the treatment of persistent asthma in adults and adolescents. FPF is available in a wide range of doses that can adequately cover the therapeutic steps recommended by treatment guidelines, constituting a fixed-dose combination of GCI/LABA that is effective, rapid, well tolerated and with a reasonable acquisition cost. Various assessment agencies of the Spanish Autonomous Communities consider this combination to be an appropriate alternative therapy for asthma in the primary care setting.

Understanding how long-acting β2 -adrenoceptor agonists enhance the clinical efficacy of inhaled corticosteroids in asthma - an update

In moderate-to-severe asthma, adding an inhaled long-acting β₂ -adenoceptor agonist (LABA) to an inhaled corticosteroid (ICS) provides better disease control than simply increasing the dose of ICS. Acting on the glucocorticoid receptor (GR, gene NR3C1), ICSs promote anti-inflammatory/anti-asthma gene expression. In vitro, LABAs synergistically enhance the maximal expression of many glucocorticoid-induced genes. Other genes, including dual-specificity phosphatase 1(DUSP1) in human airways smooth muscle (ASM) and epithelial cells, are up-regulated additively by both drug classes. Synergy may also occur for LABA-induced genes, as illustrated by the bronchoprotective gene, regulator of G-protein signalling 2 (RGS2) in ASM. Such effects cannot be produced by either drug alone and may explain the therapeutic efficacy of ICS/LABA combination therapies. While the molecular basis of synergy remains unclear, mechanistic interpretations must accommodate gene-specific regulation. We explore the concept that each glucocorticoid-induced gene is an independent signal transducer optimally activated by a specific, ligand-directed, GR conformation. In addition to explaining partial agonism, this realization provides opportunities to identify novel GR ligands that exhibit gene expression bias. Translating this into improved therapeutic ratios requires consideration of GR density in target tissues and further understanding of gene function. Similarly, the ability of a LABA to interact with a glucocorticoid may be suboptimal due to low β₂ -adrenoceptor density or biased β₂ -adrenoceptor signalling. Strategies to overcome these limitations include adding-on a phosphodiesterase inhibitor and using agonists of other Gs-coupled receptors. In all cases, the rational design of ICS/LABA, and derivative, combination therapies requires functional knowledge of induced (and repressed) genes for therapeutic benefit to be maximized.

Effect of budesonide and azelastine on histamine signaling regulation in human nasal epithelial cells

Both glucocorticoids and H1-antihistamines are widely used on patients with airway diseases. However, their direct effects on airway epithelial cells are not fully explored. Therefore, we use the primary culture of human nasal epithelial cells (HNEpC) to delineate in vitro mucosal responses to above two drugs. HNEpC cells were cultured with/without budesonide and azelastine. The growth rate at each group was recorded and measured as population double time (PDT). The histamine1-receptor (H1R), muscarinic1-receptor (M1R) and M3R were measured using immunocytochemistry and western blotting after 7-days treatment. Then, we used histamine and methacholine to stimulate the mucus secretion from HNEpC and observed the MUC5AC expression in culture supernatants. Concentration-dependent treatment-induced inhibition of HNEpC growth rate was observed. Cells incubated with azelastine proliferated significantly slower than that with budesonide and the combined use of those drugs led to significant PDT prolong. The immunocytochemistry showed the H1R, M1R and M3R were obviously located in the cell membrane without apparent difference after treatment. However, western blotting showed that budesonide can significantly up-regulate the H1R, M1R and M3R level while azelastine had opposite effects. Histamine and methacholine stimulated MUC5AC secretion was greater in cells treated with budesonide but was lesser in those treated with azelastine, as compared to controls. Our data suggest that both budesonide and azelastine can significantly inhibit HNEpC proliferation, and therefore, be helpful in against airway remodeling. Long-term use of budesonide might amplify histamine signaling and result in airway hyperreactivity to stimulants by enhancing H1R, M1R and M3R expression while azelastine can oppose this effect. Therefore, combined use of those two drugs in patients with chronic inflammatory airway diseases may be an ideal option.

Bronchoprotection and bronchorelaxation in asthma: New targets, and new ways to target the old ones

Despite over 50years of inhaled beta-agonists and corticosteroids as the default management or rescue drugs for asthma, recent research suggests that new therapeutic options are likely to emerge. This belief stems from both an improved understanding of what causes and regulates airway smooth muscle (ASM) contraction, and the identification of new targets whose inhibition or activation can relax ASM. In this review we discuss the recent findings that provide new insight into ASM contractile regulation, a revolution in pharmacology that identifies new ways to "tune" G protein-coupled receptors to improve therapeutic efficacy, and the discovery of several novel targets/approaches capable of effecting bronchoprotection or bronchodilation.

Molecular and cellular mechanisms underlying the therapeutic effects of budesonide in asthma

Inhaled glucocorticoids are the mainstay of asthma treatment. Indeed, such therapeutic agents effectively interfere with many pathogenic circuits underpinning asthma. Among these drugs, during the last decades budesonide has been probably the most used molecule in both experimental studies and clinical practice. Therefore, a large body of evidence clearly shows that budesonide, either alone or in combination with long-acting bronchodilators, provides a successful control of asthma in many patients ranging throughout the overall spectrum of disease severity. These excellent therapeutic properties of budesonide basically depend on its molecular mechanisms of action, capable of inhibiting within the airways the activity of multiple immune-inflammatory and structural cells involved in asthma pathobiology.

Glucocorticoid-independent modulation of GR activity: Implications for immunotherapy

Pharmacological doses of glucocorticoids (GCs), acting via the glucocorticoid receptor (GR) to repress inflammation and immune function, remain the most effective therapy in the treatment of inflammatory and immune diseases. Since many patients on GC therapy exhibit GC resistance and severe side-effects, much research is focused on developing more selective GCs and combination therapies, with greater anti-inflammatory potency. GCs mediate their classical genomic transcriptional effects by binding to the cytoplasmic GR, followed by nuclear translocation and modulation of transcription of target genes by direct DNA binding of the GR or its tethering to other transcription factors. Recent evidence suggests, however, that the responses mediated by the GR are much more complex and involve multiple parallel mechanisms integrating simultaneous signals from other receptors, both in the absence and presence of GCs, to shift the sensitivity of a target cell to GCs. The level of cellular stress, immune activation status, or the cell cycle phase may be crucial for determining GC sensitivity and GC responsiveness as well as subcellular localization of the GR and GR levels. Central to the development of new drugs that target GR signaling alone or as add-on therapies, is an in-depth understanding of the molecular mechanisms of GC-independent GR desensitization, priming and activation of the unliganded GR, as well as synergy and cross-talk with other signaling pathways. This review will discuss the information currently available on these topics and their relevance to immunotherapy, as well as identify unanswered questions and future areas of research.

Fixed-Dose combination of the inhaled corticosteroid and long-acting beta2-agonist therapy in adults with persistent asthma

INTRODUCTION

Asthma is a respiratory condition characterized by airway inflammation, airflow obstruction, and bronchial hyperresponsiveness. The standard treatment of asthma comprises inhaled corticosteroid and beta2-agonist. Inhaled short-acting-beta2-agonists have been used as rescue medication for exacerbation. However, long-acting-beta2-agonists (LABA) used as monotherapy for asthma had been reported for having a safety concern. Consequently, it had been recommended as an add-on treatment to inhaled corticosteroid (ICS) in moderate to severe persistent asthma. The fixed-dose combination (FDC) of ICS and LABA has been approved since the year 2000. Evidences revealed using the combination of these medications is more effective in asthma control.

AREAS COVERED

The rational and phase III onward randomized-controlled studies were reviewed. Sources of evidences were from studies published in Medline until November 2015.

EXPERT OPINION

There are six FDC inhaler regimens approved worldwide. The significant synergistic effects of ICS and LABA in one device are well evidenced. A FDC reduces the daily dosage of ICS and asthma exacerbation. It is safe to use regularly as controller. The efficacy of each individual combination on asthma treatment is generally similar. Clinical experience, ease of use, cost and side effects of medication would guide the clinician's preferences.

Anti-inflammatory effects of the novel inhaled phosphodiesterase type 4 inhibitor CHF6001 on virus-inducible cytokines

Respiratory virus infections precipitate asthma and chronic obstructive pulmonary disease (COPD) exacerbations, with most exacerbations due to rhinovirus infection. Both asthma and COPD exacerbations are not well controlled by steroid therapies, and there is a much research interest in finding improved therapies or combinations of therapies for controlling exacerbations. CHF6001 is a new, inhaled highly potent and selective phosphodiesterase type 4 (PDE4) inhibitor. Using in vitro human bronchial epithelial cells (BEAS‐2B), we investigated the potential anti‐inflammatory effects of CHF6001 on rhinovirus (RV1B)‐induced cytokines. Cytokine mRNA was measured by real‐time PCR, while protein release was measured by ELISA. CHF6001 was used in a 7‐point dose–response curve (1000–0.001 nmol/L) as a 1.5‐h pretreatment prior to infection in comparison with roflumilast. Both roflumilast and CHF6001 reduced RV1B‐induced IL‐8, IL‐29, IP‐10, and RANTES mRNA and protein in a concentration‐dependent manner. Generally, CHF6001 was 13‐ to 16‐fold more potent (subnanomolar EC₅₀ values) than roflumilast at reducing IL‐8, IL‐29, IP‐10, and RANTES mRNA and protein release, but had similar efficacies. In combination with the steroid fluticasone propionate (1 nmol/L), CHF6001 had additive effects, significantly reducing RV‐induced cytokines when compared with steroid or CHF6001 alone. Combined low‐dose steroid and low‐dose CHF6001 had a similar efficacy as high‐dose steroid or CHF6001 alone, indicating the combination had steroid and PDE4 inhibitor sparing effects. Overall results indicate that PDE4 inhibitors have anti‐inflammatory activity against virus‐induced inflammatory mediators and that CHF6001 is more potent than roflumilast.

Pharmacogenomics of long-acting β2-agonists

INTRODUCTION

Long-acting β2-agonists are an effective class of drugs, when combined with inhaled corticosteroids, for reducing symptoms and exacerbations in patients with asthma that is not adequately controlled by inhaled corticosteroids alone. However, because this class of drugs has been associated with severe adverse events, including hospitalization and death in small numbers of patients, efforts to identify a pharmacogenetic profile for patients at risk has been diligently investigated.

AREAS COVERED

The PubMed search engine of the National Library of Medicine was used to identify English-language and non-English language articles published from 1947 to March 2015 pertinent to asthma, pharmacogenomics, and long-acting β2-agonists. Keywords and topics included: asthma, asthma control, long-acting β2-agonists, salmeterol, formoterol, pharmacogenetics, and pharmacogenomics. This strategy was also used for the Cochrane Library Database and CINAHL. Reference types were randomized controlled trials, reviews, and editorials. Additional publications were culled from reference lists. The publications were reviewed by the authors and those most relevant were used to support the topics covered in this review.

EXPERT OPINION

Children, who carry the ADRB2 Arg16Arg genotype, may be at greater risk than adults for severe adverse events. Rare ADRB2 variants appear to provide better clues for identifying the at-risk population of asthmatics.

Why use long acting bronchodilators in chronic obstructive lung diseases? An extensive review on formoterol and salmeterol

Long-acting β2-adrenoceptor agonists, formoterol and salmeterol, represent a milestone in the treatments of chronic obstructive lung diseases. Although no specific indications concerning the choice of one molecule rather than another are provided by asthma and COPD guidelines, they present different pharmacological properties resulting in distinct clinical employment possibilities. In particular, salmeterol has a low intrinsic efficacy working as a partial receptor agonist, while formoterol is a full agonist with high intrinsic efficacy. From a clinical perspective, in the presence of low β2-adrenoceptors availability, like in inflamed airways, a full agonist can maintain its bronchodilatory and non-smooth muscle activities while a partial agonist may be less effective. Furthermore, formoterol presents a faster onset of action than salmeterol. This phenomenon, combined with the molecule safety profile, leads to a prompt amelioration of the symptoms, and allows using this drug in asthma as an "as needed" treatment in patients already on regular treatment. The fast onset of action and the full agonism of formoterol need to be considered in order to select the best pharmacological treatment of asthma and COPD.

Formoterol synergy with des-ciclesonide inhibits IL-4 expression in IgE/antigen-induced mast cells by inhibiting JNK activation

Inhaled corticosteroid (ICS) therapy in combination with long-acting β-adrenergic agonists (LABA) is the most important treatment for allergic asthma, although the mechanism still remains unclear. However, mast cells play a central role in the pathogenesis of asthma. In this study, we explored the sole or synergetic effects of des-ciclesonide (ICS) and formoterol (LABA) on the cytokines IL-4 and IL-13 and on histamine release from mast cells (RBL-2H3 cells). We found that des-ciclesonide (0.1, 1 and 10nM) and formoterol (0.1, 1 and 10μM) alone attenuated DNP-BSA-induced IL-4 and IL-13 production, respectively, in a concentration-dependent manner in DNP-IgE-sensitized mast cells. Des-ciclesonide (0.2nM) and formoterol (1μM) alone also reduced histamine production. However, the combination of des-ciclesonide (0.2nM) and formoterol (1μM) had a synergistic inhibition effect on IL-4 mRNA expression and protein production but not IL-13 and histamine release. The JNK inhibitor SP600125 (10μM) inhibited antigen-induced mRNA expression and protein production of IL-4. Des-ciclesonide and formoterol alone inhibited the activation of JNK in a concentration-dependent manner, and the combination of des-ciclesonide (0.2nM) and formoterol (1μM) exhibited greater inhibition effect compared with des-ciclesonide (0.2nM) or formoterol (1μM) alone. Taken together, these synergistic effects on mast cells might provide the rationale for the development of the most recent ICS/LABA combination approved for asthma therapy.

The long-acting β2 -adrenoceptor agonist, indacaterol, enhances glucocorticoid receptor-mediated transcription in human airway epithelial cells in a gene- and agonist-dependent manner

BACKGROUND AND PURPOSE

Inhaled glucocorticoid (ICS)/long-acting β2 -adrenoceptor agonist (LABA) combination therapy is a recommended treatment option for patients with moderate/severe asthma in whom adequate control cannot be achieved by an ICS alone. Previously, we discovered that LABAs can augment dexamethasone-inducible gene expression and proposed that this effect may explain how these two drugs interact to deliver superior clinical benefit. Herein, we extended that observation by analysing, pharmacodynamically, the effect of the LABA, indacaterol, on glucocorticoid receptor (GR)-mediated gene transcription induced by seven ligands with intrinsic activity values that span the spectrum of full agonism to antagonism.

EXPERIMENTAL APPROACH

BEAS-2B human airway epithelial cells stably transfected with a 2× glucocorticoid response element luciferase reporter were used to model gene transcription together with an analysis of several glucocorticoid-inducible genes.

KEY RESULTS

Indacaterol augmented glucocorticoid-induced reporter activation in a manner that was positively related to the intrinsic activity of the GR agonist. This effect was demonstrated by an increase in response maxima without a change in GR agonist affinity or efficacy. Indacaterol also enhanced glucocorticoid-inducible gene expression. However, the magnitude of this effect was dependent on both the GR agonist and the gene of interest.

CONCLUSIONS AND IMPLICATIONS

These data suggest that indacaterol activates a molecular rheostat, which increases the transcriptional competency of GR in an agonist- and gene-dependent manner without apparently changing the relationship between fractional GR occupancy and response. These findings provide a platform to rationally design ICS/LABA combination therapy that is based on the generation of agonist-dependent gene expression profiles in target and off-target tissues.

Concomitant inhibition of primary equine bronchial fibroblast proliferation and differentiation by selective β2-adrenoceptor agonists and dexamethasone

Altered airway cell proliferation plays an important role in the pathogenesis of human bronchial asthma and chronic obstructive pulmonary disease (COPD) as well as the equine recurrent airway obstruction (RAO) with consistent changes, i.e. narrowing the airway wall, explained by proliferation and differentiation of fibroblasts. In permanent cell lines, it has been suggested that β2-adrenoceptor agonists and glucocorticoids regulate cell proliferation via the β2-adrenoceptor pathway; indeed, no study was carried out in fresh isolated primary equine bronchial fibroblasts (EBF). We characterized the β-adrenoceptors in EBF, and compared effects of long-acting (clenbuterol) and short-acting (salbutamol and isoproterenol) β2-agonists and dexamethasone on proliferation, differentiation and collagen synthesis. High density (Bmax; 5037±494 sites/cell) of β2-adrenoceptor subtype was expressed in EBF. β2-agonists inhibited concentration-dependently EBF proliferation with potency of clenbuterol>salbutamol »isoproterenol which was inhibited by ICI 118.551 and propranolol but not by CGP 20712A. In contrast, dexamethasone alone inhibited less EBF proliferation, but the effect was high when dexamethasone was combined with β2-agonists. Transforming growth factor-β1 (TGF-β1) increased transformation of fibroblasts into myofibroblasts, which was inhibited by clenbuterol and dexamethasone alone and drug combination resulted in high inhibition rate. Collagen synthesis in EBF was rather hampered by dexamethasone than by β-agonists. Collectively, the expression of β2-adrenoceptor subtype in EBF and the anti-proliferative effect of clenbuterol suggest that β2-adrenoceptors are growth inhibitory and anti-fibrotic in EBF. These β2-agonist effects in EBF were synergistically enhanced by dexamethasone, providing the additive effects of glucocorticoids to counteract airway remodelling and morbidity of asthma and RAO.

Cyclic nucleotide-based therapeutics for chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) defines a group of chronic inflammatory disorders of the airways that are characterised by a progressive and largely irreversible decline in expiratory airflow. Drugs used to treat COPD through actions mediated by cyclic AMP (cAMP) are restricted to long-acting and short-acting β2-adrenoceptor agonists and, in a subset of patients with chronic bronchitis, a phosphodiesterase 4 inhibitor, roflumilast. These agents relax airway smooth muscle and suppress inflammation. At the molecular level, these effects in the airways are mediated by two cAMP effectors, cAMP-dependent protein kinase and exchange proteins activated by cAMP. The pharmacology of newer agents, acting through these systems, is discussed here with an emphasis on their potential to interact and increase therapeutic effectiveness.

Fast beneficial systemic anti-inflammatory effects of inhaled budesonide and formoterol on circulating lymphocytes in asthma

BACKGROUND AND OBJECTIVE

Inhaled glucocorticoids and long acting β2 -agonists reduce airway inflammation. It is unclear if this effect is based on the local action of the drugs or is due to a systemic effect on circulating peripheral blood lymphocytes. We assessed whether inhaled budesonide and/or formoterol modify the activity of circulating peripheral blood lymphocytes.

METHODS

Placebo controlled crossover design, including healthy (n = 10) or mild asthmatic males (n = 8). Blood was collected in the morning at 08:00 before drug inhalation, and drugs (placebo, budesonide 400 μg, formoterol 12 μg) were inhaled alone or in combination at 08:30. Four more blood samples were collected after inhalation at 09:00, 09:30, 12:30 and at 09:30 am on the following day. The activity of the glucocorticoid receptor, NFκB and IκB was determined in isolated lymphocytes. Lymphocytes were stimulated with lipopolysaccharide (LPS 10 μg/mL) for 24 h and interleukin (IL)-1β, IL-6, IL-8, tumor necrosis factor (TNF)-α, eotaxin level were determined. Lymphocyte proliferation was induced by phytohaemagglutinin (PHA 10 μg/mL) over 24 h.

RESULTS

When combined, the drugs synergistically activated the glucocorticoid receptor within 30 min but did not modify NFκB or IκB activity. Inhaled budesonide significantly reduced LPS-induced IL-1β, IL-6, IL-8 and TNF-α secretion, while inhaled formoterol had no such effect; however when combined, the inhibitory effect of budesonide was significantly increased by formoterol. PHA-induced proliferation was reduced by both drugs alone and in combination.

CONCLUSIONS

Combined budesonide and formoterol may reduce airway inflammation and immune reactivity of circulating lymphocytes through its local and systemic effects.

Profile of fluticasone furoate/vilanterol dry powder inhaler combination therapy as a potential treatment for COPD

Currently, there is no cure for chronic obstructive pulmonary disease (COPD). The limited efficacy of current therapies for COPD indicates a pressing need to develop new treatments to prevent the progression of the disease, which consumes a significant amount of health care resources and is an important cause of mortality worldwide. Current national and international guidelines for the management of stable COPD patients recommend the use of inhaled long-acting bronchodilators, inhaled corticosteroids, and their combination for maintenance treatment of moderate to severe stable COPD. Once-daily fluticasone furoate/vilanterol dry powder inhaler combination therapy has recently been approved by the US Food and Drug Administration and the European Medicines Agency as a new regular treatment for patients with stable COPD. Fluticasone furoate/vilanterol dry powder inhaler combination therapy has been shown to be effective in many controlled clinical trials involving thousands of patients in the regular treatment of stable COPD. This is the first once-daily combination of ultra-long-acting inhaled β₂-agonists and inhaled glucocorticoids that is available for the treatment of stable COPD and has great potential to improve compliance to long-term regular inhaled therapy and hence to improve the natural history and prognosis of COPD patients.

Comparing clinical efficacy of Symbicort versus Pulmicort in reducing asthma symptom and improving its control

Background:

Recently, higher efficacy of the combination of long-acting beta2-adrenoceptor agonist and inhaled corticosteroids on controlling asthma symptoms has been hypothesized. This study aimed to examine the clinical effects of the combination of Budesonide with formoterol (Symbicort) and Budesonide (Pulmicort) alone in persistent asthma.

Materials and Methods:

In a randomized double-blinded clinical trial, 76 patients with definite diagnosis of moderate-to-severe asthma were randomized to receive Pulmicort 180 mcg/inhalation two puffs twice daily, or receive Symbicort 80/4.5 mg/inhalation two puffs twice daily, or receive Symbicort 160/4.5 mg/inhalation two puffs twice daily for 3 months. All participants were initially evaluated by spirometry for assessing respiratory parameters and also the level of asthma control was assessed by Asthma Control Test (ACT).

Results:

More significant improvement in spirometry parameters, including forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), FEV1/FVC ratio, as well as in peak expiratory flow (PEF) in both groups of Symbicort with the regimens 80/4.5 mg/inhalation or 160/4.5 mg/inhalation 2 puffs twice daily compared with Pulmicort group, ACT score was significantly improved in Symbicort group with the regimens 160/4.5 mg/inhalation compared with both Symbicort groups with lower dosage and Pulmicort group. Response to treatment in PEF parameter and also in ACT level was significantly more in those who received Symbicort with the regimens 160/4.5 mg/inhalation compared with other two interventional groups adjusted for gender and age.

Conclusion:

Symbicort with the regimens 160/4.5 mg/inhalation has higher efficacy in reducing asthma symptom and improving its control compared with low doses of this drug and with Pulmicort.

Synergistic interaction between PPAR ligands and salbutamol on human bronchial smooth muscle cell proliferation

BACKGROUND AND PURPOSE

An important objective in asthma therapy is to prevent the accelerated growth of airway smooth muscle cells which leads to hyperplasia and bronchial hyperreactivity. We investigated the effect of combination of salbutamol and PPARγ agonists on growth factor-stimulated human bronchial smooth muscle cell (BSMC) proliferation.

EXPERIMENTAL APPROACH

Synergism was quantified by the combination index-isobologram method. Assays used here included analyses of growth inhibition, cell viability, DNA fragmentation, gene transcription, cell cycle and protein expression.

KEY RESULTS

The PPARγ gene was highly expressed in BSMC and the protein was identified in cell nuclei. Single-agent salbutamol or PPARγ agonists prevented growth factor-induced human BSMC proliferation within a micromolar range of concentrations through their specific receptor subtypes. Sub-micromolar levels of combined salbutamol-PPARγ agonist inhibited growth by 50% at concentrations from ∼2 to 12-fold lower than those required for each drug alone, without induction of apoptosis or necrosis. Combination treatments also promoted cell cycle arrest at the G1/S transition phase and inhibition of ERK phosphorylation.

CONCLUSIONS AND IMPLICATIONS

The synergistic interaction between PPARγ agonists and β(2) -adrenoceptor agonists on airway smooth muscle cell proliferation highlights the anti-remodelling potential of this combination in chronic lung diseases.

Can the anti-inflammatory activities of β2-agonists be harnessed in the clinical setting?

Beta2-adrenoreceptor agonists (β2-agonists) are primarily bronchodilators, targeting airway smooth muscle and providing critical symptomatic relief in conditions such as bronchial asthma and chronic obstructive pulmonary disease. These agents also possess broad-spectrum, secondary, anti-inflammatory properties. These are mediated largely, though not exclusively, via interactions with adenylyl cyclase-coupled β2-adrenoreceptors on a range of immune and inflammatory cells involved in the immunopathogenesis of acute and chronic inflammatory disorders of the airways. The clinical relevance of the anti-inflammatory actions of β2-agonists, although often effective in the experimental setting, remains contentious. The primary objectives of the current review are: firstly, to assess the mechanisms, both molecular and cell-associated, that may limit the anti-inflammatory efficacy of β2-agonists; secondly, to evaluate pharmacological strategies, several of which are recent and innovative, that may overcome these limitations. These are preceded by a consideration of the various types of β2-agonists, their clinical applications, and spectrum of anti-inflammatory activities, particularly those involving adenosine 3',5'-cyclic adenosine monophosphate-activated protein kinase-mediated clearance of cytosolic calcium, and altered gene expression in immune and inflammatory cells.

Extraneuronal monoamine transporter mediates the permissive action of cortisol in the Guinea pig trachea: possible involvement of tracheal chondrocytes

Cortisol, a member of glucocorticoids, could potentiate the action of catecholamine by a non-genomic mechanism. Although this permissive effect has been well appreciated in the anti-asthmatic medication, the underlying signaling pathway has remained mysterious. Here, we show that extraneuronal monoamine transporter (EMT), a membraneous reuptake transporter for circulating catecholamine clearance, is the direct target of cortisol in its permissive effect. We found that BSA-conjugated cortisol, which functions as a cortisol but cannot penetrate cell membrane, enhanced the spasmolytic effect of β-adrenoceptor agonist (isoprenaline) in histamine-sensitized tracheal spirals of guinea pigs, and pharmacological inhibition of EMT with famotidine was powerful enough to imitate the permissive action of cortisol. To our surprise, EMT protein expression was high in the chondrocytes of tracheal cartilage, but was undetectable in tracheal smooth muscle cells. The functionality of EMT was further confirmed with measurement of catecholamine uptake by tracheal chondrocytes. Moreover, cortisol-initiated membrane signaling could activate protein kinase C (PKC), which phosphorylates EMT and induces its internalization via a lipid raft-dependent pathway. Both of the mechanisms slow down the reuptake process by chondrocytes, leading to extracellular catecholamine accumulation and results in a more profound adrenergic signaling activation in tracheal smooth muscle cells. Thus, an EMT-centered pathway was proposed to explain the permissive action of cortisol. Collectively, our results highlight the role of EMT in the crosstalk between glucocorticoid and catecholamine. EMT may represent a promising target for adrenergic signaling modulation.

Inhaled long-acting β2 agonists enhance glucocorticoid receptor nuclear translocation and efficacy in sputum macrophages in COPD

BACKGROUND

Combination inhaled therapy with long-acting β2 agonists (LABAs) and corticosteroids is beneficial in treating asthma and chronic obstructive pulmonary disease (COPD).

OBJECTIVE

In asthma, LABAs enhance glucocorticoid receptor (GR) nuclear translocation in the presence of corticosteroids. Whether this biological mechanism occurs in COPD, a relatively corticosteroid-resistant disease, is uncertain.

METHODS

Eight patients with mild/moderate COPD participated in a double-blind, placebo-controlled, crossover study and inhaled single doses of fluticasone propionate (FP) 100 μg, FP 500 μg, salmeterol xinafoate (SLM) 50 μg, and combination FP 100 μg + SLM 50 μg. One hour postinhalation, sputum was induced, nuclear proteins isolated from purified macrophages, and levels of activated nuclear GR quantified by using a GR-glucocorticoid response element ELISA-based assay.

RESULTS

Nuclear GR significantly increased after the inhalation of FP 500 μg (P < .01), but not after the inhalation of FP 100 μg or SLM 50 μg, compared with placebo. Interestingly, SLM in combination with FP 100 μg increased nuclear GR levels equivalent to those of FP 500 μg alone. This was significantly greater than either FP 100 μg (P < .05) or SLM 50 μg (P < .01) alone. In vitro in a human macrophage cell line, SLM (10(-8) mol/L) enhanced FP (10(-9) mol/L)-induced mitogen-activated protein kinase phosphatase-1 mRNA (5.8 ± 0.6 vs 8.4 ± 1.1 × 10(-6) copies, P < .05) and 2 × glucocorticoid response element-luciferase reporter gene activity (250.1 ± 15.6 vs 103.1 ± 23.6-fold induction, P < .001). Addition of SLM (10(-9) mol/L) to FP (10(-11) mol/L) significantly enhanced FP-mediated suppression of IL-1β-induced CXCL8 (P < .05).

CONCLUSIONS

Addition of SLM 50 μg to FP 100 μg enhanced GR nuclear translocation equivalent to that seen with a 5-fold higher dose of FP in sputum macrophages from patients with COPD. This may account for the superior clinical effects of combination LABA/corticosteroid treatment compared with either as monotherapy observed in COPD.

Inhaled corticosteroid and long-acting β2-agonist pharmacological profiles: effective asthma therapy in practice

Fixed-dose combinations of inhaled corticosteroids (ICSs) and long-acting β2-agonists (LABAs) have been used to manage asthma for several years. They are the preferred therapy option for patients who do not achieve optimal control of their asthma with low-dose ICS monotherapy. In Europe, four ICS/LABA products are commercially available for asthma maintenance therapy (fluticasone propionate/formoterol fumarate, fluticasone propionate/salmeterol xinafoate, budesonide/formoterol fumarate and beclometasone dipropionate/formoterol fumarate), and other combinations are likely to be developed over the next few years (e.g. mometasone/formoterol fumarate, fluticasone furoate/vilanterol, mometasone/indacaterol). Data from randomized, controlled, clinical trials do not demonstrate a clear overall efficacy difference among ICS/LABA combinations approved for asthma therapy. Conversely, pharmacological data indicate that there may be certain advantages to using one ICS or LABA over another because of the specific pharmacodynamic and pharmacokinetic profiles associated with particular treatments. This review article summarizes the pharmacological characteristics oft he various ICSs and LABAs available for the treatment of asthma, including the potential for ICS and LABA synergy, and gives an insight into the rationale for the development of the latest ICS/LABA combination approved for asthma maintenance therapy.

Concurrent agonism of adenosine A2B and glucocorticoid receptors in human airway epithelial cells cooperatively induces genes with anti-inflammatory potential: a novel approach to treat chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is a neutrophilic inflammatory disorder that is weakly responsive to glucocorticoids. Identification of ways to enhance the anti-inflammatory activity of glucocorticoids is, therefore, a major research objective. Adenosine receptor agonists that target the A2B-receptor subtype are efficacious in several cell-based assays and preclinical models of inflammation. Accordingly, the present study was designed to determine if a selective A2B-receptor agonist, 2-[6-amino-3,5-dicyano-4-[4-(cyclopropylmethoxy)phenyl]pyridin-2-ylsulphanyl]acetamide (Bay 60-6583), and a glucocorticoid, dexamethasone, in combination display putative anti-inflammatory activity that is superior to either drug alone. In BEAS-2B human airway epithelial cells stably transfected with cAMP-response element (CRE) and glucocorticoid response element (GRE) reporter constructs, Bay 60-6583 promoted CRE-dependent transcription and enhanced GRE-dependent transcription by an adenosine A2B-receptor-mediated mechanism that was associated with cAMP formation and abolished by an inhibitor of cAMP-dependent protein kinase. Analysis of the concentration-response relationship that described the enhancement of GRE-dependent transcription showed that Bay 60-6583 increased the magnitude of response without affecting the potency of dexamethasone. Bay 60-6583 and dexamethasone also induced a panel of genes that, collectively, could have benefit in COPD. These were categorized into genes that were induced in a positive cooperative manner (RGS2, p57(kip2)), an additive manner (TTP, BRL-1), or by Bay 60-6583 (CD200, CRISPLD2, SOCS3) or dexamethasone (GILZ) only. Thus, the gene induction "fingerprints" produced by Bay 60-6583 and dexamethasone, alone and in combination, were distinct. Collectively, through their actions on gene expression, an adenosine A2B-receptor agonist and a glucocorticoid administered together may have utility in the treatment of inflammatory disorders that respond suboptimally to glucocorticoids as a monotherapy.

Modulation of transcriptional responses by poly(I:C) and human rhinovirus: effect of long-acting β₂-adrenoceptor agonists

Exacerbations of asthma, a chronic inflammatory respiratory disease, are associated with viral upper respiratory tract infections involving human rhinovirus. Although glucocorticoids (corticosteroids) effectively control airways inflammation in many asthmatics, human rhinovirus-associated exacerbations show reduced glucocorticoid responsiveness. Using human bronchial epithelial BEAS-2B cells, we show that human rhinovirus reduced glucocorticoid-inducible activation of glucocorticoid response element (GRE) reporter systems in a time- and concentration-dependent manner. The synthetic double-stranded viral RNA mimetic, polyinosinic:polycytidylic acid (poly(I:C)), also reduced activation of GRE reporter systems in BEAS-2B and pulmonary A549 cells. In addition, poly(I:C) decreased transcription from cAMP response element (CRE)-, TATA-, simian virus 40- and nuclear factor-kappa B (NF-κB)-dependent reporter systems. The effects of poly(I:C) on GRE-reporter activation were countered by the long-acting β2-adrenoceptor agonists, formoterol and salmeterol. Likewise, increased expression of the gene cyclin-dependent kinase inhibitor 1C (CDKN1C; p57(KIP2)) by dexamethasone was reduced by poly(I:C), but was substantially enhanced by the addition of formoterol. Poly(I:C) induced the expression of interleukin-8 (IL8; CXCL8) and this was significantly decreased by dexamethasone, formoterol or their combination. This confirms that not all transcriptional responses were attenuated by poly(I:C) and that decreased glucocorticoid-dependent transcription can be counteracted by the addition of long-acting β2-adrenoceptor agonists. These data show how human rhinovirus may attenuate glucocorticoid-induced transcription to reduce anti-inflammatory activity. However, addition of long-acting β2-adrenoceptor agonist to the glucocorticoid functionally restored this response and shows how glucocorticoid plus long-acting β2-adrenoceptor agonist combinations may prove beneficial during virus-induced exacerbations of asthma.

Role of transcription factors in the pathogenesis of asthma and COPD

Inflammation is a central feature of asthma and chronic obstructive pulmonary disease (COPD). Despite recent advances in the knowledge of the pathogenesis of asthma and COPD, much more research on the molecular mechanisms of asthma and COPD are needed to aid the logical development of new therapies for these common and important diseases, particularly in COPD where no effective treatments currently exist. In the future the role of the activation/repression of different transcription factors and the genetic regulation of their expression in asthma and COPD may be an increasingly important aspect of research, as this may be one of the critical mechanisms regulating the expression of different clinical phenotypes and their responsiveness to therapy, particularly to anti-inflammatory drugs.

cAMP regulation of airway smooth muscle function

Agonists activating β(2)-adrenoceptors (β(2)ARs) on airway smooth muscle (ASM) are the drug of choice for rescue from acute bronchoconstriction in patients with both asthma and chronic obstructive pulmonary disease (COPD). Moreover, the use of long-acting β-agonists combined with inhaled corticosteroids constitutes an important maintenance therapy for these diseases. β-Agonists are effective bronchodilators due primarily to their ability to antagonize ASM contraction. The presumed cellular mechanism of action involves the generation of intracellular cAMP, which in turn can activate the effector molecules cAMP-dependent protein kinase (PKA) and Epac. Other agents such as prostaglandin E(2) and phosphodiesterase inhibitors that also increase intracellular cAMP levels in ASM, can also antagonize ASM contraction, and inhibit other ASM functions including proliferation and migration. Therefore, β(2)ARs and cAMP are key players in combating the pathophysiology of airway narrowing and remodeling. However, limitations of β-agonist therapy due to drug tachyphylaxis related to β(2)AR desensitization, and recent findings regarding the manner in which β(2)ARs and cAMP signal, have raised new and interesting questions about these well-studied molecules. In this review we discuss current concepts regarding β(2)ARs and cAMP in the regulation of ASM cell functions and their therapeutic roles in asthma and COPD.