Inhaled glucocorticoids for asthma

Glucocorticoids shift arachidonic acid metabolism toward endocannabinoid synthesis: a non-genomic anti-inflammatory switch

Glucocorticoids are capable of exerting both genomic and non-genomic actions in target cells of multiple tissues, including the brain, which trigger an array of electrophysiological, metabolic, secretory and inflammatory regulatory responses. Here, we have attempted to show how glucocorticoids may generate a rapid anti-inflammatory response by promoting arachidonic acid-containing endocannabinoids biosynthesis. According to our hypothesized model, non-genomic action of glucocorticoids results in the global shift of membrane lipid metabolism, subverting metabolic pathways toward the synthesis of the anti-inflammatory endocannabinoids, anandamide (AEA) and 2-arachidonoyl-glycerol (2-AG), and away from arachidonic acid production. Post-transcriptional inhibition of cyclooxygenase-2 (COX(2)) synthesis by glucocorticoids assists this mechanism by suppressing the synthesis of pro-inflammatory prostaglandins as well as endocannabinoid-derived prostanoids. In the central nervous system (CNS) this may represent a major neuroprotective system, which may cross-talk with leptin signaling in the hypothalamus allowing for the coordination between energy homeostasis and the inflammatory response.

Pioglitazone is as effective as dexamethasone in a cockroach allergen-induced murine model of asthma

Background

While glucocorticoids are currently the most effective therapy for asthma, associated side effects limit enthusiasm for their use. Peroxisome proliferator-activated receptor-γ (PPAR-γ) activators include the synthetic thiazolidinediones (TZDs) which exhibit anti-inflammatory effects that suggest usefulness in diseases such as asthma. How the ability of TZDs to modulate the asthmatic response compares to that of glucocorticoids remains unclear, however, because these two nuclear receptor agonists have never been studied concurrently. Additionally, effects of PPAR-γ agonists have never been examined in a model involving an allergen commonly associated with human asthma.

Methods

We compared the effectiveness of the PPAR-γ agonist pioglitazone (PIO) to the established effectiveness of a glucocorticoid receptor agonist, dexamethasone (DEX), in a murine model of asthma induced by cockroach allergen (CRA). After sensitization to CRA and airway localization by intranasal instillation of the allergen, Balb/c mice were challenged twice at 48-h intervals with intratracheal CRA. Either PIO (25 mg/kg/d), DEX (1 mg/kg/d), or vehicle was administered throughout the period of airway CRA exposure.

Results

PIO and DEX demonstrated similar abilities to reduce airway hyperresponsiveness, pulmonary recruitment of inflammatory cells, serum IgE, and lung levels of IL-4, IL-5, TNF-α, TGF-β, RANTES, eotaxin, MIP3-α, Gob-5, and Muc5-ac. Likewise, intratracheal administration of an adenovirus containing a constitutively active PPAR-γ expression construct blocked CRA induction of Gob-5 and Muc5-ac.

Conclusion

Given the potent effectiveness shown by PIO, we conclude that PPAR-γ agonists deserve investigation as potential therapies for human asthma.

Genome-wide profiling identifies epithelial cell genes associated with asthma and with treatment response to corticosteroids

Airway inflammation and epithelial remodeling are two key features of asthma. IL-13 and other cytokines produced during T helper type 2 cell-driven allergic inflammation contribute to airway epithelial goblet cell metaplasia and may alter epithelial-mesenchymal signaling, leading to increased subepithelial fibrosis or hyperplasia of smooth muscle. The beneficial effects of corticosteroids in asthma could relate to their ability to directly or indirectly decrease epithelial cell activation by inflammatory cells and cytokines. To identify markers of epithelial cell dysfunction and the effects of corticosteroids on epithelial cells in asthma, we studied airway epithelial cells collected from asthmatic subjects enrolled in a randomized controlled trial of inhaled corticosteroids, from healthy subjects and from smokers (disease control). By using gene expression microarrays, we found that chloride channel, calcium-activated, family member 1 (CLCA1), periostin, and serine peptidase inhibitor, clade B (ovalbumin), member 2 (serpinB2) were up-regulated in asthma but not in smokers. Corticosteroid treatment down-regulated expression of these three genes and markedly up-regulated expression of FK506-binding protein 51 (FKBP51). Whereas high baseline expression of CLCA1, periostin, and serpinB2 was associated with a good clinical response to corticosteroids, high expression of FKBP51 was associated with a poor response. By using airway epithelial cells in culture, we found that IL-13 increased expression of CLCA1, periostin, and serpinB2, an effect that was suppressed by corticosteroids. Corticosteroids also induced expression of FKBP51. Taken together, our findings show that airway epithelial cells in asthma have a distinct activation profile and identify direct and cell-autonomous effects of corticosteroid treatment on airway epithelial cells that relate to treatment responses and can now be the focus of specific mechanistic studies.

Chronobiology and chronotherapy of allergic rhinitis and bronchial asthma

Study of the chronobiology of allergic rhinitis (AR) and bronchial asthma (BA) and the chronopharmacology and chronotherapy of the medications used in their treatment began five decades ago. AR is an inflammatory disease of the upper airway tissue with hypersensitivity to specific environmental antigens, resulting in further local inflammation, vasomotor changes, and mucus hypersecretion. Symptoms include sneezing, nasal congestion, and runny and itchy nose. Approximately 25% of children and 40% of adults in USA are affected by AR during one or more seasons of the year. The manifestation and severity of AR symptoms exhibit prominent 24-h variation; in most persons they are worse overnight or early in the morning and often comprise nighttime sleep, resulting in poor daytime quality of life, compromised school and work performance, and irritability and moodiness. BA is also an inflammatory medical condition of the lower airways characterized by hypersensitivity to specific environmental antigens, resulting in greater local inflammation as well as bronchoconstriction, vasomotor change, and mucus hypersecretion. In USA an estimated 6.5 million children and 15.7 million adults have BA. The onset and worsening of BA are signaled by chest wheeze and/or croupy cough and difficult and labored breathing. Like AR, BA is primarily a nighttime medical condition. AR is treated with H1-antagonist, decongestant, and anti-inflammatory (glucocorticoid and leukotriene receptor antagonist and modifier) medications. Only H1-antagonist AR medications have been studied for their chronopharmacology and potential chronotherapy. BA is treated with some of the same medications and also theophylline and beta2-agonists. The chronopharmacology and chronotherapy of many classes of BA medications have been explored. This article reviews the rather extensive knowledge of the chronobiology of AR and BA and the chronopharmacology and chronotherapy of the various medications used in their treatment.

Peroxisome proliferator-activated receptor-gamma agonists as potential anti-inflammatory agents in asthma and chronic obstructive pulmonary disease

Inhaled corticosteroids are the most effective therapy for chronic persistent asthma and have a role in the treatment of chronic obstructive pulmonary disease (COPD). However, corticosteroids have reduced efficacy in some patients with asthma and fail to halt the progressive deterioration in lung function characteristic of COPD. Additional or alternative drug treatments to corticosteroids are required to improve control of inflammation in patients with therapy resistant airway disease. Peroxisome proliferator-activated receptor-gamma (PPAR-gamma) agonists have displayed potent anti-inflammatory properties in experimental models of asthma and other airway diseases and as a result have the potential to become an additional treatment for asthma and COPD. We review the evidence from these experimental models and their applicability to asthma and COPD and the requirements for future clinical and experimental research.

Keys to successful management of patients with allergic rhinitis: focus on patient confidence, compliance, and satisfaction

OBJECTIVE

The American Academy of Otolaryngic Allergy (AAOA) convened an expert, multidisciplinary Working Group on Allergic Rhinitis to discuss patients' self-treatment behaviors and how health care providers approach and treat the condition. PROCEDURES AND DATA SOURCES: Co-moderators, who were chosen by the AAOA Board of Directors, were responsible for initial agenda development and selection of presenters and participants, based on their expertise in diagnosis and treatment of allergic rhinitis. Each presenter performed a literature search from which a presentation was developed, portions of which were utilized in developing this review article.

SUMMARY OF FINDINGS

Allergic rhinitis is a common chronic condition that has a significant negative impact on general health, co-morbid illnesses, productivity, and quality of life. Treatment of allergic rhinitis includes avoidance of allergens, immunotherapy, and/or pharmacotherapy (ie, antihistamines, decongestants, corticosteroids, mast cell stabilizers, anti-leukotriene agents, anticholinergics). Despite abundant treatment options, 60% of all allergic rhinitis patients in an Asthma and Allergy Foundation of America survey responded that they are "very interested" in finding a new medication and 25% are "constantly" trying different medications to find one that "works." Those who were dissatisfied also said their health care provider does not understand their allergy treatment needs and does not take their allergy symptoms seriously. Dissatisfaction leads to decreased compliance and an increased reliance on multiple agents and over-the-counter products. Furthermore, a lack of effective communication between health care provider and patient leads to poor disease control, noncompliance, and unhappiness in a significant portion of patients.

CONCLUSIONS

Health care providers must gain a greater understanding of patient expectations to increase medication compliance and patient satisfaction and confidence.

Do chronic inhaled steroids alone or in combination with a bronchodilator prolong life in chronic obstructive pulmonary disease patients?

PURPOSE OF REVIEW

Inhaled corticosteroids with or without long-acting beta2 adrenergic agonists are commonly used to treat patients with chronic obstructive pulmonary disease to attenuate symptoms and to prevent exacerbations. Whether these medications prolong survival is uncertain.

RECENT FINDINGS

Inhaled corticosteroids attenuate airway and systemic inflammation, reduce airway hyperreactivity, improve patient symptoms and prevent exacerbations in chronic obstructive pulmonary disease patients. The data on mortality are mixed. A pooled analysis of published randomized controlled trials indicated that inhaled corticosteroids reduced mortality by around 25%; however other studies have failed to show a beneficial effect on mortality. The addition of long-acting beta2 adrenergic agonists to inhaled corticosteroids enhances the clinical effectiveness of these medications and confers incremental mortality benefits to patients. Interestingly, these medications appear to be especially beneficial in reducing cardiovascular morbidity and mortality, though large randomized controlled trials powered specifically on these endpoints are needed to confirm these early findings.

SUMMARY

Inhaled corticosteroids, especially with long-acting beta2 adrenergic agonists, reduce airway inflammation and appear to prolong survival in chronic obstructive pulmonary disease patients. They may be particularly effective in reducing cardiovascular morbidity and mortality of patients, pending confirmation by additional clinical studies powered specifically on these endpoints.

Effect of inhaled budesonide on oropharyngeal, Gram-negative bacilli colonization in asthma patients

BACKGROUND AND OBJECTIVE

The effect of inhaled budesonide on oropharyngeal Gram-negative bacilli colonization (OGNBC) in asthmatic patients was investigated.

METHODS

Oropharyngeal cultures were obtained from asthmatic patients attending the hospital respiratory outpatient clinic, at baseline and 1 month after treatment with 800 microg/day of inhaled budesonide. Cultures were evaluated for OGNBC and compared with those of healthy controls.

RESULTS

A total of 148 cultures (74 from asthma patients, 74 from healthy controls) were evaluated. Six cultures (8.1%) from healthy controls, eight cultures (10.8%) from asthma patients obtained before treatment and 20 cultures (27.0%) obtained after treatment were positive for OGNBC (P < 0.05). Gender, age, presence of atopy and the degree of illness were not found to be related to the presence of OGNBC in and healthy control cultures. In the cultures obtained from the patients after treatment, OGNBC was higher in patients >50 years and in those with FEV1 < 70% (P < 0.05). Nine (18.8%) of 48 patients <50 years compare with 11 (42.3%) of the 26 patients >50 revealed OGNBC (P < 0.05). OGNBC were observed in 18.9% of the patients with FEV1 = 70% and in 47.6% of those with FEV1 < 70% (P < 0.05).

CONCLUSIONS

The increased rate of OGNBC in asthma patients treated with inhaled budesonide was found to be related to increased age and lower level of FEV1. Further studies with larger numbers of patients are required for the interpretation of this colonization in the course of lower respiratory infections in these patients.

Critical appraisal of antileukotriene use in asthma management

PURPOSE OF REVIEW

Recognition of the importance of leukotrienes in the pathogenesis of asthma has led to the development of leukotriene modifiers, the first new class of drugs for asthma treatment to become available since the introduction of inhaled corticosteroids. Nevertheless, despite their widespread use in clinical practice, the role of leukotriene modifiers in the management of asthma remains controversial. In the present article the clinical applications of this class of drugs have been critically reviewed based on recent evidence.

RECENT FINDINGS

In an effort to try and establish the proper place of antileukotrienes in the management of asthma, important systematic reviews have been carried out over these recent years in three critical areas: antileukotrienes as second choice first line agents after inhaled corticosteroids; antileukotrienes as add-on therapy to inhaled corticosteroids; add-on antileukotrienes versus long acting beta-agonists to patients not controlled by inhaled corticosteroids. In addition, novel and useful clinical targets for this class of drugs have been recently explored and include: patients with severe asthma; aspirin-intolerant asthma; asthmatic patients with allergic rhinitis.

SUMMARY

Use of antileukotrienes is not recommended as first-line monotherapy in patients with asthma, except those who have aspirin intolerant asthma. Patients with concomitant allergic rhinitis may be a good target population for therapy with antileukotrienes. Addition of leukotriene modifiers to inhaled corticosteroids produces only a modest improvement in the clinical response, and is not greater to that of add-on long acting beta-agonists. The exact role of antileukotrienes in asthma management guidelines still continues to evolve.

Ciclesonide disposition and metabolism: pharmacokinetics, metabolism, and excretion in the mouse, rat, rabbit, and dog

The pharmacokinetics, metabolism, and excretion of ciclesonide, a novel and effective inhaled glucocorticoid for the treatment of asthma, were investigated after intravenous and oral administration of 14C-ciclesonide in the mouse, rat, rabbit, and dog. The pharmacokinetics of ciclesonide in all animal species were characterized by a low oral bioavailability (approximately 6% or less), a high clearance, and a large volume of distribution. The apparent terminal half-life of ciclesonide was short; the apparent terminal half-life of the active desisobutyryl-ciclesonide metabolite (des-CIC or M1) was longer and ranged from 2.4 to 6.9 hours in the 4 species. Metabolites derived from ciclesonide in serum (or plasma) and excreta samples from the 4 animal species were profiled and identified by LC/RAM/MS (liquid chromatography/radioactivity monitor/mass spectrometry). Ciclesonide was extensively metabolized to yield des-CIC, which was further metabolized to primarily yield hippuric acid and hydroxylated metabolites, namely, isomers of cyclohexane-monohydroxylated des-CIC and B-ring-monohydroxylated des-CIC. Greater than 90% of intravenous and oral 14C-ciclesonide doses were recovered in all species; the main elimination route was fecal/biliary. A comparison of in vitro and in vivo metabolite profiles between mice, rats, rabbits, and dogs with those from humans indicated that metabolic pathways for ciclesonide were qualitatively similar in humans and in the 4 animal species.

Inhaled steroids are associated with reduced lung function decline in subjects with asthma with elevated total IgE

BACKGROUND

Few studies have investigated the long-term association between inhaled corticosteroids (ICSs) and lung function decline in asthma.

OBJECTIVE

To evaluate whether prolonged treatment with ICSs is associated with FEV(1) decline in adults with asthma.

METHODS

An international cohort of 667 subjects with asthma (20-44 years old) was identified in the European Community Respiratory Health Survey (1991-1993) and followed up from 1999 to 2002. Spirometry was performed on both occasions. FEV(1) decline was analyzed according to age, sex, height, body mass index, total IgE, time of ICS use, and smoking, while adjusting for potential confounders.

RESULTS

As ICS use increased, the decline in FEV(1) was lower (P trend = .025): on average, decline passed from 34 mL/y in nonusers (half of the sample) to 20 mL/y in subjects treated for 48 months or more (18%). When adjusting for all covariates, there was an interaction (P = .02) between ICS use and total IgE: in subjects with high (>100 kU/L) IgE, ICS use for 4 years or more was associated with a lower FEV(1) decline (23 mL/y; 95% CI, 8-38 compared with nonusers). This association was not seen in those with lower IgE.

CONCLUSION

Although confirming a beneficial long-term association between ICSs and lung function in asthma, our study suggests that subjects with high IgE could maximally benefit from a prolonged ICS treatment.

CLINICAL IMPLICATIONS

This study adds further evidence to the beneficial effect of inhaled steroids on lung function in asthma; future studies will clarify whether calibrating the corticosteroid dose according to the level of total IgE is a feasible approach in asthma management.

New Dosage Formulations for Targeted Delivery of Cyclo-Oxygenase-2 Inhibitors

NSAIDs are a widely used class of analgesic and anti-inflammatory drugs that act by inhibiting the cyclo-oxygenase (COX) enzyme. However, because of their nonspecificity of action, use of these agents as long-term therapy for chronic pain in diseases such as rheumatoid arthritis (RA) and osteoarthritis (OA) is often discouraged. Among NSAIDs, COX-2 inhibitors are promising candidates for long-term therapy of chronic diseases, particularly in the elderly, because of their reduced incidence of gastrointestinal adverse effects. However, in recent times these agents have also been shown to cause adverse effects such as cardiovascular effects (myocardial infarction, stroke and hypertension) and renal effects (decreased renal blood flow/glomerular filtration rate), which in 2004 led to the withdrawal of rofecoxib and in 2005 the withdrawal of valdecoxib from the US market. Importantly, these adverse effects can be effectively reduced by achieving site specific/targeted delivery through new formulation approaches. These formulations not only restrict the drug supply to specific organs but also reduce the dose required. As a result, use of new delivery systems such as nanoparticles, microparticles, microemulsions and nanogels has gained widespread applicability in the management of chronic disease, especially in the elderly, and particularly when there is a need to decrease dose-dependent adverse effects (as is the case with COX-2 inhibitors). This article reviews various new approaches to the delivery of COX-2 inhibitors and highlights issues related to the development of delivery systems for these agents for RA, OA, cancer (familial adenomatous polyposis, prostate, breast and non-small cell lung cancer), ocular diseases (such as diabetic retinopathy) and inflammatory diseases of the skin, with emphasis on their potential for use in the elderly. Emphasis is also placed on the preparation of these particulate systems, their release profile and behaviour in biological systems.

Inhaled budesonide in the management of acute worsenings and exacerbations of asthma: a review of the evidence

The use of systemic corticosteroids, together with bronchodilators and oxygen therapy, has become established for the management of acute asthma. These agents are undoubtedly effective, but are also associated with problems such as metabolic adverse effects. Inhaled corticosteroids (ICS) offer potential benefit in the acute setting because they are delivered directly to the airways. They are also likely to reduce systemic exposure, which would lead in turn to reductions in rates of unwanted systemic effects. In order to evaluate the role of budesonide in the management of acute asthma exacerbations we conducted a review of the literature and critically evaluated the rationale for the use of ICS in general in this setting. Trials in adults and children requiring treatment for acute exacerbation of asthma have shown clinical and/or spirometric benefit for budesonide when delivered via nebulizer, dry powder inhaler, or aerosol in the emergency department, hospital and follow-up settings. The efficacy seems to benefit from high doses given repeatedly during the initial phase of an acute exacerbation. These acute effects are likely to be linked to the drug's distinctive pharmacokinetic and pharmacodynamic profile. The current evidence base revealed encouraging results regarding the efficacy of the ICS budesonide in patients with wheeze and acute worsening of asthma. Future studies should focus on the efficacy of these agents in more severe asthma worsenings.

The anti-inflammatory effect of glucocorticoids is mediated by glucocorticoid-induced leucine zipper in epithelial cells

BACKGROUND

Nuclear factor kappaB (NF-kappaB) plays a key role in the pathogenesis of asthma, being linked to the production of inflammatory cytokines that drive inflammation. A recently described anti-inflammatory protein, glucocorticoid-induced leucine zipper (GILZ), interferes with NF-kappaB-mediated gene transcription in T cells and macrophages.

OBJECTIVE

We sought to analyze the regulation of GILZ expression in airway epithelial cells and determine whether GILZ mediates part of the anti-inflammatory effect of corticosteroids.

METHODS

GILZ expression was assessed by means of PCR and immunoblotting in human epithelial cells at baseline and after stimulation with dexamethasone or cytokines (IL-1beta, TNF-alpha, and IFN-gamma). The effect of GILZ on LPS-, IL-1beta-, and polyinosinic:polycytidylic acid-induced NF-kappaB activation was assessed in BEAS-2B cells overexpressing GILZ. The requirement for GILZ in the inhibitory action of dexamethasone was assessed by knocking down GILZ expression by means of small interfering RNA (siRNA) technology.

RESULTS

GILZ is constitutively expressed by human airway epithelial cells, and its levels are increased by dexamethasone and decreased by inflammatory cytokines. Overexpression of GILZ in BEAS-2B cells significantly inhibited the ability of IL-1beta, LPS, and polyinosinic:polycytidylic acid to activate NF-kappaB, whereas knockdown of GILZ inhibited the ability of dexamethasone to suppress IL-1beta-induced chemokine expression.

CONCLUSION

This study demonstrates the expression of GILZ in human airway epithelial cells, its induction by dexamethasone, its suppression by inflammatory cytokines, and its role in mediating the anti-inflammatory effects of dexamethasone.

CLINICAL IMPLICATIONS

Therapeutic upregulation of GILZ may be a novel strategy for the treatment of asthma.

High-dose inhaled fluticasone does not replace oral prednisolone in children with mild to moderate acute asthma

BACKGROUND

Inhaled corticosteroids are not as effective as oral corticosteroids in school-aged children with severe acute asthma. It is uncertain how inhaled corticosteroids compare with oral corticosteroids in mild to moderate exacerbations.

PRIMARY OBJECTIVE

The purpose of this work was to determine whether there is a significant difference in the percentage of predicted forced expiratory volume in 1 second in children with mild to moderate acute asthma treated with either inhaled fluticasone or oral prednisolone.

METHODS

This was a randomized, double-blind controlled trial conducted between 2001 and 2004 in a tertiary care pediatric emergency department. We studied a convenience sample of 69 previously healthy children 5 to 17 years of age with acute asthma and forced expiratory volume in 1 second at 50% to 79% predicted value; 41 families refused participation. Albuterol was given in the emergency department and salmeterol was given after discharge to all patients, as well as either 2 mg of fluticasone via metered dose inhaler and valved holding chamber in the emergency department plus 500 microg twice daily via Diskus for 10 doses after discharge (fluticasone group, N = 35) or 2 mg/kg of oral prednisolone in the emergency department plus 5 daily doses of 1 mg/kg of prednisolone after discharge (prednisolone group, N = 34). We measured a priori defined absolute change in percent predicted forced expiratory volume in 1 second from baseline to 4 and 48 hours in the 2 groups. RESULTS. At 240 minutes, the forced expiratory volume in 1 second increased by 19.1% +/- 12.7% in the fluticasone group and 29.8% +/- 15.5% in the prednisolone group. At 48 hours, this difference was no longer significant (estimated difference: 4.0 +/- 3.4; P = .14). The relapse rates by 48 hours were 12.5% and 0% in the fluticasone group and prednisolone group, respectively.

CONCLUSION

Airway obstruction in children with mild to moderate acute asthma in the emergency department improves faster on oral than inhaled corticosteroids.

Pharmacologic characteristics and adrenal suppression with newer inhaled corticosteroids: A comparison of ciclesonide and fluticasone propionate

BACKGROUND

Inhaled corticosteroids (ICSs) are the most potent anti-inflammatory choice for patients with asthma. Selecting the most appropriate ICS for a patient requires a thorough understanding of the pharmacologic properties of each drug.

OBJECTIVE

This review details the pharmacologic properties of ciclesonide (CIC) and fluticasone propionate (FP) and reviews the available data on suppression of the hypothalamic-pituitary-adrenal axis as a measure of systemic exposure and safety profile.

METHODS

Clinical studies and case reports were identified through a MEDLINE and EMBASE search of English-language articles. The databases were searched for the years 1990 to April 2005 using the terms ciclesonide, fluticasone, ICS, and adrenal suppression. All studies were clinical trials of pharmacologic properties of the ICSs in humans.

RESULTS

A total of 1082 articles were identified. CIC and FP are 2 of the most potent ICSs. Both have high receptor-binding affinities (12 times and 18 times that of dexamethasone, respectively), and both may provide enhanced respiratory effects through a prolonged pulmonary residence time. The CIC metered dose inhaler dispenses smaller and more highly respirable particles than FP (1.1-2.1 pm vs 2.8-3.2 microm, respectively). Therefore, a greater percentage of administered CIC is topically deposited in the lungs (52% vs 12% to 13% for FP). CIC is delivered as an inactive parent compound, which is converted to its active metabolite, desisobutyryl-CIC (des-CIC), by esterases in the airways. More than 50% of a dose of CIC is deposited and distributed evenly throughout the lungs of healthy adults; lipid conjugation in the lung also may increase lung residence time. On entering the systemic circulation, both corticosteroids are rapidly cleared by the liver (elimination half-life of 3.5 hours for CIC vs 7.8 hours for FP). However, plasma protein binding is greater with CIC/des-CIC (99%/ approximately 99%) than FP (90%), resulting in reduced amounts of des-CIC (<I%) versus FP (10%) circulating free in the plasma. Although studies of low or medium doses of FP have produced conflicting results, high doses of FP (>660 pg/d) may result in adrenal suppression. CIC has not been reported to produce any significant adrenal suppression throughout its studied dose range (up to 1280 micro/d).

CONCLUSIONS

A review of the literature suggests that CIC, as compared with FP, achieves greater pulmonary deposition, causes fewer adverse oropharyngeal effects, deposits less biologically active drug in the systemic circulation, and has less potential for adrenal suppression.

Anti-allergic properties of Cissampelos sympodialis and its isolated alkaloid warifteine

Development of new agents capable of regulating eosinophilic inflammation can uncover novel therapeutic approaches for the treatment of allergic diseases, such as asthma. Here, we evaluated the anti-allergic properties of an extract of the Brazilian Menispermaceae Cissampelos sympodialis, focusing on its effects on allergic eosinophilia. By studying two models of allergic inflammation, an asthma model and the allergic pleurisy in actively sensitized Balb/c mice, we observed that the oral pre-treatment with C. sympodialis reduced pleural eosinophil influx triggered by allergen challenge in a dose-dependent manner. The mechanism involved in C. sympodialis inhibitory effect appeared to be independent of a direct effect on eosinophil locomotory machinery, but depend on a blockage of eotaxin production, a key eosinophil chemoattractant with important roles in allergic reactions. C. sympodialis was also able to affect eosinophil activation, as attested by its ability of inhibiting formation of new cytoplasmic lipid bodies and the secretion of cysteinyl leukotrienes. The alkaloid warifteine isolated from the C. sympodialis extract represents an active component responsible for the anti-eosinophilic effects of the extract, since warifteine was able to reproduce C. sympodialis inhibitory effects on allergic eosinophilia and cysteinyl leukotrienes production. Of interest, C. sympodialis and warifteine post-treatments also effectively inhibited eosinophilic reaction observed after allergic challenge. Therefore, C. sympodialis/warifteine may be a promising anti-allergic therapy, inasmuch as it presents potent anti-eosinophil and anti-leukotrienes activities.

Cushing syndrome with secondary adrenal insufficiency from concomitant therapy with ritonavir and fluticasone

We present 2 cases of Cushing syndrome with secondary adrenal insufficiency from concomitant use of ritonavir and inhaled corticosteroids in children with human immunodeficiency virus infection. These cases highlight the need for special consideration when treatment with an inhaled/intranasal corticosteroid is indicated in children receiving antiretroviral therapy.

Can inhaled fluticasone alone or in combination with salmeterol reduce systemic inflammation in chronic obstructive pulmonary disease? Study protocol for a randomized controlled trial [NCT00120978]

Background

Systemic inflammation is associated with various complications in chronic obstructive pulmonary disease including weight loss, cachexia, osteoporosis, cancer and cardiovascular diseases. Inhaled corticosteroids attenuate airway inflammation, reduce exacerbations, and improve mortality in chronic obstructive pulmonary disease. Whether inhaled corticosteroids by themselves or in combination with a long-acting β₂-adrenoceptor agonist repress systemic inflammation in chronic obstructive pulmonary disease is unknown. The Advair Biomarkers in COPD (ABC) study will determine whether the effects of inhaled corticosteroids alone or in combination with a long-acting β₂-adrenoceptor agonist reduce systemic inflammation and improve health status in patients with chronic obstructive pulmonary disease.

Methods/Design

After a 4-week run-in phase during which patients with stable chronic obstructive pulmonary disease will receive inhaled fluticasone (500 micrograms twice daily), followed by a 4-week withdrawal phase during which all inhaled corticosteroids and long acting β₂-adrenoceptor agonists will be discontinued, patients will be randomized to receive fluticasone (500 micrograms twice daily), fluticasone/salmeterol combination (500/50 micrograms twice daily), or placebo for four weeks. The study will recruit 250 patients across 11 centers in western Canada. Patients must be 40 years of age or older with at least 10 pack-year smoking history and have chronic obstructive pulmonary disease defined as forced expiratory volume in one second to vital capacity ratio of 0.70 or less and forced expiratory volume in one second that is 80% of predicted or less. Patients will be excluded if they have any known chronic systemic infections, inflammatory conditions, history of previous solid organ transplantation, myocardial infarction, or cerebrovascular accident within the past 3 months prior to study enrolment. The primary end-point is serum C-reactive protein level. Secondary end-points include circulating inflammatory cytokines such as interleukin-6 and interleukin-8 as well as health-related quality of life and lung function.

Discussion

If inhaled corticosteroids by themselves or in combination with a long-acting β₂-adrenoceptor agonist could repress systemic inflammation, they might greatly improve clinical prognosis by reducing various complications in chronic obstructive pulmonary disease.

Double-blind, randomised, controlled trial assessing controller medications in asthma

BACKGROUND

The motive behind conducting this study was to determine if better control of asthma can be achieved by adding a second controller medication and to assess its use to reduce the dose of inhaled steroids.

OBJECTIVES

The study aimed to determine whether either oral sustained-release theophylline or montelukast added to inhaled steroids improved clinical symptoms and pulmonary function test parameters when compared to high-dose steroids alone.

METHODS

Ninety patients with incompletely controlled asthma were allocated, in a randomised, double-blind fashion, to one of three treatment groups: group A: double dose of inhaled budesonide (400 microg b.i.d.), group B: 400 mg oral sustained-release theophylline plus budesonide (200 microg b.i.d.) and group C: 10 mg montelukast plus budesonide (200 microg b.i.d.). The primary endpoints were forced expiratory volume in 1 s (FEV(1)) and mean morning peak expiratory flow rate (PEFR).

RESULTS

All three groups had improved FEV(1) and PEFR at 8 weeks (p < 0.001). Group C increased their PEFR by 18.7 l/min (95% confidence interval, CI, 12.4-25.1) more than group A and by 19.8 l/min (95% CI 13.4-26.1) more than group B (both p = 0.001). Similarly, group C had a 114 ml (95% CI 45-183 ml) greater improvement in FEV(1) than group A and a 95 ml (95% CI 26-164 ml) greater improvement than group B (both p = 0.01).

CONCLUSIONS

Addition of montelukast to budesonide is safe and results in greater improvement in pulmonary function test parameters than high-dose budesonide treatment or addition of theophylline.

Benefit versus risk for oral, inhaled, and nasal glucocorticosteroids

Many factors affect the benefit-to-risk analysis of the use of the glucocorticosteroids in the treatment of allergic inflammation. For most patients the benefit-to-risk ratio favors topical over oral administration, but in severe disease oral administration may be required. It is clear from pharmacokinetic and pharmacodynamic studies that inhaled glucocorticosteroids in particular are absorbed into the systemic circulation and that they can have clinical adverse effects when given in high doses. Therefore, with inhaled and nasal glucocorticosteroids, the dose that will achieve the optimal benefit/risk ratio is the lowest dose that controls symptoms and prevents exacerbations requiring treatment with oral glucocorticosteroids. This optimal dose needs to be determined on an individual basis and is likely to vary as disease severity changes over time.

Effects of steroid treatment on lung CC chemokines, apoptosis and transepithelial cell clearance during development and resolution of allergic airway inflammation

BACKGROUND

Steroid treatment of allergic eosinophilic airway diseases is considered to attenuate cell recruitment by inhibiting several chemokines and to cause eosinophil clearance through inducement of apoptosis of these cells. However, roles of these mechanisms in the actions of steroids in vivo have not been fully established. Also, as regards clearance of tissue eosinophils other mechanisms than apoptosis may operate in vivo.

OBJECTIVE

This study explores anti-inflammatory effects of steroids instituted during either development or resolution of airway allergic inflammation.

METHODS

Immunized mice were subjected to week-long daily allergen challenges (ovalbumin). Steroid treatment was instituted either amidst the challenges or exclusively post-allergen challenge. CC chemokines, goblet cell hyperplasia, occurrence of eosinophil apoptosis, and airway tissue as well as lumen eosinophilia were examined at different time-points.

RESULTS

Daily steroids instituted amid the allergen challenges non-selectively attenuated a range of chemokines, permitted egression of tissue eosinophils into airway lumen to increase, and reduced development of lung tissue eosinophilia. Steroid treatment instituted post-challenge selectively inhibited the CC-chemokine regulation upon activation, normal T cell expressed and secrted (RANTES), permitted continued egression of eosinophils into airway lumen, and resolved the tissue eosinophilia. Eosinophil apoptosis rarely occurred at development and resolution of the allergic eosinophilic inflammation whether the animals were steroid treated or not. However, anti-Fas monoclonal antibodies given to mice with established eosinophilia post-challenge produced apoptosis of the tissue eosinophils indicating that apoptotic eosinophils, if they occur, are well detectible in vivo.

CONCLUSION

Airway tissue eosinophils are likely eliminated through egression into airway lumen with little involvement of apoptosis and phagocytosis. Our data further suggest that therapeutic steroids may resolve airway inflammation by permitting clearance of tissue eosinophils through egression and inhibiting RANTES-dependent cell recruitment to lung tissues.

Inhaled Corticosteroids Adverse Events In Asthmatic Children: A Review

BACKGROUND: Inhaled corticosteroids (ICS) have an important role in the treatment of chronic asthma in children. The prevalence of asthma symptoms in children varies from 0 to 30 percent in different populations with the highest prevalence occurring in Australia, New Zealand and England. METHODS: A review of the literature and studies about inhaled corticosteroids safety, action and adverse events in children and adults where applicable was done. CONCLUSION: Inhaled corticosteroids are the main stay therapy for persistent asthma in children. Their safety and efficacy is proven from the literature. Proper education of the parents about asthma and inhaled corticosteroids is very important and improve asthma control. Keeping in mind to taper the inhaled corticosteroids to the lowest dose needed to control asthma and using correct inhalation technique by the use of spacers with metered dose inhalers or dry powder inhalers (Turbuhaler and Diskus) will prevent the occurrence of adverse events.

Factors influencing the responsiveness to inhaled glucocorticoids of patients with moderate-to-severe asthma

STUDY OBJECTIVES

Inhaled glucocorticoids (GCs) are the most effective control therapy for asthma. Although the clinical effects of inhaled GCs vary, there are few data on the differences in the responsiveness of individuals to inhaled GCs. The purpose of this study was to identify those factors that are associated with responsiveness to high-dose inhaled GCs in patients with moderate-to-severe asthma.

DESIGN

This study was a prospective analysis.

SETTING

Outpatient clinics of tertiary hospitals.

PATIENTS

Eighty-six adult outpatients with moderate-to-severe asthma.

METHODS

Eighty-six patients with asthma who had initial FEV1 values of < 80% predicted after they had received inhaled GCs (fluticasone propionate, 1,000 microg/d) for 4 weeks. The primary end points were FEV1, FEV1/FVC ratio, forced expiratory flow (midexpiratory phase), and the score at presentation in the asthma-related quality-of-life questionnaire (AQLQ).

RESULTS

The inhalation of GCs for 4 weeks had significant improvements in the FEV1% predicted and in the AQLQ score compared with the baseline values. Asthmatic patients with responses of > 12% (n = 46, 53.4%) in the change in FEV1 (deltaFEV1 = [FEV1 at 4 weeks--baseline FEV1]/baseline FEV1 x 100) also had significantly higher proportions of blood eosinophils and lower FEV1 values (in liters) prior to treatment. The change in FEV1 values correlated with the number of sputum eosinophils prior to GC inhalation (r = 0.242; p < 0.05) and correlated inversely with the FEV1 percent predicted values prior to GC inhalation (r = -0.462; p < 0.001).

CONCLUSION

The FEV1 percent predicted and the blood and sputum eosinophil levels prior to GC inhalation are associated with the responsiveness to inhaled GCs in patients with moderate-to-severe asthma.

Dexamethasone inhibits phosphorylation of histone H3 at serine 10

Glucocorticoids are the most effective anti-inflammatory drugs used in the treatment of inflammatory diseases. While phosphorylation of histone H3 at serine 10 (p-Ser10) is one of the histone modifications related to transcription of some inflammation-related genes, the effect of glucocorticoids on p-Ser10 is not established. Here, we investigated the ability of dexamethasone (Dex) to inhibit p-Ser10 expression in response to tumor necrosis factor (TNF-alpha) in the human lung adenocarcinoma cell line A549 and the SV-40-transformed human airway epithelial cell line BEAS-2B. By Western blot analysis in BEAS-2B cells, the expression of p-Ser10 was repressed by pretreatment with Dex, an effect not seen in A549 cells. Flow cytometric analysis at a single-cell level in A549 cells indicated that TNF-alpha treatment caused early induction of p-Ser10 at 15 min, which was inhibited significantly by pretreatment with 10(-5) M Dex. By immunostaining, the p-Ser10 signal appeared as granules in TNF-alpha-treated cells at same sites of phosphorylated RNA polymerase II. In contrast, the signal was scattered in the nuclei of Dex-pretreated cells. These findings suggested that Dex limits airway inflammation by inhibiting p-Ser10 expression and redistributing p-Ser10 away from transcription sites.

Successful withdrawal of inhaled corticosteroids in childhood asthma

OBJECTIVE

Although inhaled corticosteroids are useful and effective in the prophylaxis of childhood asthma, there is a dearth of information regarding the duration of treatment. The present study was undertaken to assess the possibility of successful withdrawal of inhaled corticosteroids in childhood asthma following good control of the disease.

METHODOLOGY

The study was carried out at the Asiri Hospital, Colombo, Sri Lanka and was a prospective observational clinical study. The participants were consecutive children with documented moderately severe and severe asthma seen over a period of 4 years from January 1990 and followed up to December 2003. Patients were allocated randomly to receive either beclomethasone dipropionate or budesonide. Initial dose of the selected drug was 300, 400 or 600 microg/day, depending on the child's age. After a period of stabilization, the dose was reduced from the starting dose to a maintenance level of 200, 300 or 400 microg/day, respectively. Once sustained control had been maintained for a period ranging from 9 to 18 months, gradual withdrawal was attempted. The dosage was reduced by 50-100 microg each time, at intervals of 3 months. Long-term follow up was maintained following withdrawal of inhaled corticosteroids. Breakthrough wheezing, acute severe attacks, hospitalization for wheezing and absence from school were used to assess the response.

RESULTS

Eighty-six children were recruited into the study. Eighty children responded well. The initial period on a high dose of corticosteroid was 8.4 months (range 4-12 months) and the average period of maintenance dosing was 11.7 months (range 9-18 months). The average time taken for withdrawal was 12.6 months (range 9-18 months). Successful withdrawal was achieved in 73 children. In this group, the mean total duration of treatment was 27.4 months (range 20-44 months). Up to December 2003, the subjects had been observed for an average period of 97.1 months (range 86-121 months) following withdrawal of inhaled corticosteroids. Of the 73 children in whom corticosteroids were withdrawn, 57 (78%) have remained well without any episodes of wheezing, and 14 (19%) have had mild episodes of wheezing that were easily controlled by bronchodilators. No patient needed hospitalization, long-term treatment or systemic corticosteroids. In two (3%) patients, it was necessary to restart inhaled corticosteroids because of troublesome recurrences.

CONCLUSION

It is possible to gradually withdraw inhaled corticosteroids in a significant proportion of asthmatic children once good control has been sustained on a maintenance dose for a considerable period.

Impact of smoking on asthma therapy: a critical review of clinical evidence

Airway inflammation is central to the pathophysiology of asthma, with treatment directed towards modification of this inflammation and its consequences. The relationship between cigarette smoking and airway inflammation is also well described, but relatively little data are available on the potential influence of smoking on asthmatic airway inflammation and its treatment. While cigarette smoking is common in people with asthma, with prevalence rates similar to the general population, studies in asthma have tended to concentrate on individuals who have never smoked. However, there is recent evidence that smoking may confer a degree of corticosteroid resistance in asthma, and this review examines the relationship between asthma and cigarette smoking, with particular reference to the impact of smoking on the response to treatment of asthma. Smoking has a number of known influences on drug activity and metabolism, but the mechanism underlying corticosteroid resistance in asthmatic smokers is not yet clear, although there are differences in the nature of the airway inflammation in individuals with asthma who smoke compared with nonsmoking asthmatic patients. Encouragingly, there is some evidence that smoking cessation may at least partially restore corticosteroid responsiveness in asthmatic ex-smokers. Smoking cessation measures must be given a high priority in individuals with asthma who smoke.

Formulation and evaluation of aerosolized celecoxib for the treatment of lung cancer

PURPOSE

We examined the effect of aerosolized celecoxib, a selective cyclooxygenase-2 (COX-2) inhibitor, on the in vitro cytotoxicity and apoptotic response of docetaxel against the human lung carcinoma cell lines A549 and H460.

METHODS

A metered dose inhaler (MDI) formulation of celecoxib was prepared and evaluated for its medication delivery and aerodynamic properties. The in vitro cytotoxicity of the aerosolized celecoxib-MDI alone or in combination with docetaxel was assessed using a six-stage viable impactor by a previously established method. The induction of apoptosis was evaluated by morphologic examination (acridine orange and Hoechst staining) and DNA fragmentation. Furthermore, in an attempt to identify molecular targets involved in the anticancer mechanisms of celecoxib and docetaxel, we examined their effect on the expression of an array of markers involved in the COX-2 dependent and independent pathways.

RESULTS

The celecoxib-MDI had a medication delivery of 231.3 microg/shot, mass median aerodynamic diameter (MMAD) of 1.4 microm (GSD = 1.9), and respirable fraction of 50.7%. The celecoxib-MDI (2 shots) in combination with docetaxel had cell kills as high as 81.3% and 67.7% in A549 and H460 cells, respectively. Hoechst and acridine orange staining showed an enhanced induction of apoptosis in A549 and H460 cells exposed to aerosolized celecoxib with docetaxel, which was further confirmed by DNA fragmentation. Western blot analysis showed a significant reduction in cPLA2 expression in both A549 and H460 cells treated with the combination of celecoxib with docetaxel. In the COX-2 independent pathway, there was a significant increase in the expression of PPAR-gamma and p53, whereas pro-caspase-3 expression was significantly decreased, which may contribute to the enhanced apoptotic response observed with the combination treatment.

CONCLUSIONS

Our results suggest that aerosolized celecoxib significantly enhances the in vitro cytotoxicity and apoptotic response of docetaxel against A549 and H460 cells, and this enhanced activity is mediated via alterations in expression of various molecular targets involved in apoptosis.

Effect of high dose inhaled glucocorticoids on quality of life in patients with moderate to severe asthma

Asthma is a chronic disorder that can place considerable restrictions on the physical, emotional, and social aspects of the lives of patients. Inhaled glucocorticoids (GCs) are the most effective controller therapy. The purpose of this study was to evaluate the effect of inhaled GCs on quality of life in patients with moderate to severe asthma. Patients completed the asthma quality of life questionnaire (AQLQ) and pulmonary function test at baseline and after 4 wks treatment of GCs. We enrolled 60 patients who had reversibility in FEV1 after 200 microgram of albuterol of 15% or more and/or positive methacholine provocation test, and initial FEV1% predicted less than 80%. All patients received inhaled GCs (fluticasone propionate 1,000 microgram/day) for 4 wks. The score of AQLQ was significantly improved following inhaled GCs (overall 51.9+/-14.3 vs. 67.5+/-12.1, p<0.05). The change from day 1 to day 28 in FEV1 following inhaled GCs was diversely ranged from -21.0% to 126.8%. The improvement of score of AQLQ was not different between at baseline and after treatment of GCs according to asthma severity and GCs responsiveness. Quality of life was improved after inhaled GCs regardless of asthma severity and GCs responsiveness in patients with moderate to severe asthma.

An update of the leukotriene modulators for the treatment of asthma

Bronchial asthma is a chronic inflammatory airway disease involving many cells and mediators. Chronic inflammation constitutes an important predisposing condition for airway remodelling with secondary irreversible airflow obstruction. Current approaches for asthma treatment involve many classes of drugs, adequate patient education for their correct use, environmental exposure control and daily monitoring of pulmonary function. Unfortunately, the use of multiple therapies complicates treatment regimens, thus leading to a reduced compliance to therapy. Available evidence from randomised clinical trials and real-word experience derived from managing patients with asthma justifies a broader role for leukotriene receptor antagonist drugs in asthma management than that recommended in the National Asthma Education and Prevention Programme and National Health Lung and Blood Institute Treatment Guidelines. While a low dose of inhaled corticosteroids remains the reference drug as a controller in mild-to-moderate persistent asthma, oral therapy with an leukotriene-receptor antagonist drug represents a good option providing the clinical efficacy requested in common clinical practice. For this reason the recent Global Initiative for Asthma Guidelines allocate this drug to the second and third steps of asthma treatment.

Tryptase inhibitors: a novel class of anti-inflammatory drugs

Tryptase, a serine protease released from mast cell secretory granules, is found at elevated levels in pathophysiologic conditions associated with allergic inflammation. The in vitro and in vivo biological activities of tryptase strongly suggest that tryptase influences lung function, inflammation, matrix degradation, and tissue remodelling. The pathophysiologic role for tryptase in diseases of airway inflammation such as asthma has been confirmed from studies using the selective tryptase inhibitor APC 366 in the allergic sheep model. APC 366 inhibited the allergen-induced early and late airway responses, blocked postchallenge airway hyperresponsiveness, and reduced airway inflammation. A pilot clinical trial with mild to moderate asthmatics also showed that APC 366 protected against allergen-induced early and late responses and reduced airway hyperresponsiveness. Current data provide compelling evidence that tryptase plays a fundamental role in allergic inflammation, and selective tryptase inhibitors may represent a novel class of anti-inflammatory therapeutics for treating asthma and other mast cell-mediated diseases.

Asthma management issues in infancy and childhood

The prevalence of asthma has been increasing worldwide over the past 2 decades, especially the prevalence of childhood asthma. Currently, the prevalence of childhood asthma is around 3-20% in different countries based on the report from the International Study of Asthma and Allergies in Children (ISAAC). Asthma in childhood is predominantly an extrinsic asthma. In general, countries in the coastal, temperate, and subtropical zones have the highest prevalence of mite- and cockroach-sensitive asthma. Countries in the sub-arctic or semi-arid areas have a lower prevalence of childhood asthma, mostly associated with sensitization to pet dander, moulds, and pollens. Many genes have been linked to asthma in different ethnic populations. A global consensus for the management of asthma in adults and children >5 years of age has been made possible in the Global Initiative for Asthma (GINA) guidelines, where a step-wise management program using inhaled medication with and without oral anti-inflammatory drugs is recommended. The management of asthma in children <5 years of age remains inconclusive. Recent studies suggest that inherited susceptibility associated with risk factors from the prenatal and postnatal environment is likely to promote allergic sensitization and development of asthma. Consequently, early prevention of prenatal sensitization in utero and environmental control of early life exposure to various allergens may decrease the incidence of childhood asthma. In the management of moderate persistent asthma in infants and young children <5 years of age, airway resistance tests (FEV(1) or PEF) are not of significance, but assessment of respiratory rate and skin pulse oximeter measurements of arterial oxygen saturation are helpful. Moreover, recent advances in pharmacogenetics and pharmacogenomics may provide better individualized care for early pharmacological prevention of childhood asthma via selective modulation of airway remodeling.

Anti-allergic properties of the bromeliaceae Nidularium procerum: inhibition of eosinophil activation and influx

New therapeutic approaches for the treatment of allergic diseases can be aided by the development of agents capable of regulating eosinophilic leukocytes. Here, we evaluated the anti-allergic properties of a crude extract of the Brazilian bromeliaceae Nidularium procerum, focusing on its effects on allergic eosinophilia. By studying allergic pleurisy in actively sensitized C57Bl/6 mice, we observed that pretreatment with N. procerum (2 mg/kg; i.p.) reduced pleural eosinophil influx triggered by allergen challenge. N. procerum was also able to reduce lipid body numbers found within infiltrating eosinophils, indicating that N. procerum in vivo is able to affect both migration and activation of eosinophils. Consistently, pretreatment with N. procerum blocked pleural eosinophil influx triggered by PAF or eotaxin, key mediators of the development of allergic pleural eosinophilia. The effect of N. procerum was not restricted to eosinophils, since N. procerum also inhibited pleural neutrophil and mononuclear cell influx. Of note, N. procerum failed to alter the acute allergic reaction, characterized by mast cell degranulation, oedema, and cysteinyl leukotriene release. N. procerum also had direct effects on murine eosinophils, since it inhibited both PAF- and eotaxin-induced eosinophil chemotaxis on an in vitro chemotactic assay. Therefore, N. procerum may be a promising anti-allergic therapy, inasmuch as it presents potent anti-eosinophil activity.

Glucocorticoid receptor nuclear translocation in airway cells after inhaled combination therapy

Clinical evidence is accumulating for the efficacy of adding inhaled long-acting beta(2)-agonists (LABAs) to corticosteroids in asthma. Corticosteroids bind to cytoplasmic glucocorticoid receptors (GRs), which then translocate to the nucleus where they regulate gene expression. This article reports the first evidence in vivo of an interaction between inhaled LABA and corticosteroid on GR nuclear translocation in human airway cells using immunocytochemistry. We initially demonstrated significant GR activation 60 minutes after inhalation of 800 microg beclomethasone dipropionate in six healthy subjects. Subsequently, we determined the effects of salmeterol and fluticasone propionate (FP) in seven steroid-naive patients with asthma. We observed dose-dependent GR activation with 100- and 500-microg doses of FP, and to a lesser extent with 50 microg salmeterol alone. However, combination therapy with 100 microg FP and salmeterol augmented the action of FP on GR nuclear localization. In vitro, salmeterol enhanced FP effects on GR nuclear translocation in epithelial and macrophage-like airway cell lines. In addition, salmeterol in combination with FP enhanced glucocorticoid response element (GRE)-luciferase reporter gene activity and mitogen-activated protein kinase phosphatase 1 (MKP-1) and secretory leuko-proteinase inhibitor (SLPI) gene induction. Together, our data confirm that GR nuclear translocation may underlie the complementary interactions between LABAs and corticosteroids, although the precise signal transduction mechanisms remain to be determined.

Repression of interleukin-5 transcription by the glucocorticoid receptor targets GATA3 signaling and involves histone deacetylase recruitment

Glucocorticoids are the mainstay of asthma therapy and mediate the repression of a number of cytokine genes, such as Interleukin (IL)-4, -5, -13, and granulocyte macrophage colony-stimulating factor (GM-CSF), which are central to the pathogenesis of asthmatic airway inflammation. The glucocorticoid receptor (GR) mediates repression by a number of diverse mechanisms. We have previously suggested that one such repressive activity is by direct binding of GR to elements within the GM-CSF enhancer that are recognized by the nuclear factor of activated T cells.activator protein 1 (NF-AT.AP-1) complex. We reasoned that, because many cytokine genes activated in asthma are transcriptionally regulated by the recruitment of this complex to DNA, their binding sites might provide a target for GR to mediate its repressive effects. Here, we show that transcriptional repression of the Interleukin-5 gene involves recruitment of GR to a DNA region located within the IL-5 proximal promoter, which is bound by NF-AT and AP-1 proteins. GR recruitment had a profound effect upon the activation capacity of GATA3, which has a binding site close to the NF-AT.AP-1 domain in both IL-5 and IL-13 promoters. Repression by GR involves co-repressor recruitment, because treatment of transfected cells with the deacetylase inhibitor trichostatin A caused a partial relief of repression. Additionally, repression could be augmented by co-transfection of cells with a histone deacetylase (HDAC1). These data suggest that the local recruitment of GR causes repression by inhibiting transcriptional activation by GATA3, a key tissue-specific determinant of expression of Th2 cytokines.

Asthma epidemiology: has the crisis passed?

PURPOSE OF REVIEW

Asthma is a difficult, resource-intensive disease that can result in symptoms, hospitalization and, in rare cases, death. In the past few decades, there has been an abundance of evidence showing the prevalence of asthma to be increasing in certain regions. However, reports have recently emerged suggesting that asthma prevalence has stabilized. This has led to debate among researchers whether increases in asthma prevalence have come to an end. We reviewed recent literature in search of answers to the ongoing debate on whether the asthma crisis is over.

RECENT FINDINGS

In contrast with past reports, several recent studies have reported a stabilization of asthma prevalence. However, based on repeated cross-sectional studies, findings regarding the stabilization of asthma prevalence have been inconsistent, especially when considering the heterogeneity of the disease, which can result in a variety of patterns concerning asthma diagnosis, symptoms, and allergic sensitization. Temporal trends considering physician visits, hospitalizations, and mortality have been more consistent, with stabilizing and decreasing patterns of asthma burden in recent years.

SUMMARY

Because reasons for the original increases in asthma prevalence remain unclear, an explanation for the apparent stabilization of asthma prevalence reported in some studies also remains elusive. This is compounded by the difficulty in defining asthma accurately in population studies and inconsistencies in the results of prevalence estimation among repeated cross-sectional studies. Efforts should be made to continue monitoring asthma prevalence and to begin monitoring asthma prevalence in regions where environmental and social changes are occurring.

Brain-immune interactions and disease susceptibility

Many studies have established the routes by which the immune and central nervous (CNS) systems communicate. This network of connections permits the CNS to regulate the immune system through both neuroendocrine and neuronal pathways. In turn, the immune system signals the CNS through neuronal and humoral routes, via immune mediators and cytokines. This regulatory system between the immune system and CNS plays an important role in susceptibility and resistance to autoimmune, inflammatory, infectious and allergic diseases. This review focuses on the regulation of the immune system via the neuroendocrine system, and underlines the link between neuroendocrine dysregulation and development of major depressive disorders, autoimmune diseases and osteoporosis.

The Role of Mitogen-activated Protein Kinase Phosphatase-1 in the Response of Alveolar Macrophages to Lipopolysaccharide

Mitogen-activated protein (MAP) kinases are critical mediators of innate immune responses. In response to lipopolysaccharide (LPS), MAP kinases are rapidly activated and play an important role in the production of proinflammatory cytokines. Although a number of MAP kinase phosphatases (MKPs) have been identified, their roles in the control of cytokine production have not been well defined. In the present report, we investigated the role of MKP-1 in alveolar macrophages stimulated with LPS. We found that LPS triggered transient activation of three MAP kinase subfamilies, ERK, JNK, and p38, in both immortalized and primary murine alveolar macrophages. MKP-1 was rapidly induced by LPS, and its induction correlated with the dephosphorylation of these MAP kinases. Blocking MKP-1 with triptolide prolonged the activities of both JNK and p38 in immortalized alveolar macrophages. Stimulation of primary alveolar macrophages isolated from MKP-1-deficient mice with LPS resulted in a prolonged p38 phosphorylation compared with wild type alveolar macrophages. Accordingly, these MKP-1-deficient alveolar macrophages also mounted a more robust and rapid tumor necrosis factor alpha production than their wild type counterparts. Adenovirus-mediated MKP-1 overexpression significantly attenuated tumor necrosis factor alpha production in immortalized alveolar macrophages. Finally, MKP-1 was induced by a group of corticosteroids frequently prescribed for the treatment of inflammatory lung diseases, and the anti-inflammatory potencies of these drugs closely correlated with their abilities to induce MKP-1. Our studies indicated that MKP-1 plays an important role in dampening the inflammatory responses of alveolar macrophages. We speculate that MKP-1 may represent a novel target for therapeutic intervention of inflammatory lung diseases.

Anti-inflammatory activity of Korean folk medicine 'Sabaeksan'

Sabaeksan has been used for prevention and treatment of bronchial asthma and allergic asthma in Korea. To investigate the biological effect of Sabaeksan, we examined the effect of Sabaeksan on the phorbol 12-myristate 13-acetate (PMA) and calcium ionophore A23187-induced pro-inflammatory cytokines secretion in human mast cell line HMC-1 cells. Sabaeksan by itself had no effect on viability of HMC-1 cells. The effects of Sabaeksan on the secretion of tumor necrosis factor (TNF)-alpha, interleukin (IL)-6, and IL-8 from HMC-1 were evaluated with enzyme-linked immunosorbent assay. Sabaeksan (1 mg/ml) inhibited PMA plus A23187-induced TNF-alpha, IL-6, and IL-8 secretion by 43.86+/-5.26%, 56.39+/-3.65%, and 63.48+/-2.54%, respectively. Sabaeksan also inhibited the nuclear factor-kappa B (NF-kappaB) activation and IkappaBalpha degradation. Taken together, these results suggest that Sabaeksan inhibits the secretion of pro-inflammatory cytokines in HMC-1 cells through blockade of NF-kappaB activation.

[Synergic effects of anti-inflammatory drugs in asthma]

Persistent asthma is a chronic airway inflammatory disease that requires treatment with anti-inflammatory drugs. Inhaled corticosteroids are the cornerstone of the treatment of airway inflammation. Clinical studies have shown that asthmatic patients treated with long-acting beta(2)-agonists and inhaled corticosteroids have more reduced exacerbations than those given higher doses of corticosteroids suggesting synergistic effects on the inflammatory process. The understanding of the molecular modes of action of these two classes of drugs explained part of the enhanced anti-inflammatory activity of the combination therapy. However, the production of cysteinyl-leukotrienes is not well controlled by corticosteroids. Anti-leukotrienes, by the blockade of the effects of cysteinyl-leukotrienes, exert therefore a complementary anti-inflammatory action.