Effects of sodium cromoglycate and nedocromil sodium on histamine secretion from human lung mast cells

Mast cells: a novel therapeutic avenue for cardiovascular diseases?

Mast cells are tissue-resident immune cells strategically located in different compartments of the normal human heart (the myocardium, pericardium, aortic valve, and close to nerves) as well as in atherosclerotic plaques. Cardiac mast cells produce a broad spectrum of vasoactive and proinflammatory mediators, which have potential roles in inflammation, angiogenesis, lymphangiogenesis, tissue remodelling, and fibrosis. Mast cells release preformed mediators (e.g. histamine, tryptase, and chymase) and de novo synthesized mediators (e.g. cysteinyl leukotriene C4 and prostaglandin D2), as well as cytokines and chemokines, which can activate different resident immune cells (e.g. macrophages) and structural cells (e.g. fibroblasts and endothelial cells) in the human heart and aorta. The transcriptional profiles of various mast cell populations highlight their potential heterogeneity and distinct gene and proteome expression. Mast cell plasticity and heterogeneity enable these cells the potential for performing different, even opposite, functions in response to changing tissue contexts. Human cardiac mast cells display significant differences compared with mast cells isolated from other organs. These characteristics make cardiac mast cells intriguing, given their dichotomous potential roles of inducing or protecting against cardiovascular diseases. Identification of cardiac mast cell subpopulations represents a prerequisite for understanding their potential multifaceted roles in health and disease. Several new drugs specifically targeting human mast cell activation are under development or in clinical trials. Mast cells and/or their subpopulations can potentially represent novel therapeutic targets for cardiovascular disorders.

Benzopyrone, a privileged scaffold in drug discovery: An overview of FDA-approved drugs and clinical candidates

Natural products have always served as an important source of drugs for treating various diseases. Among various privileged natural product scaffolds, the benzopyrone class of compounds has a substantial presence among biologically active compounds. One of the pioneering anticoagulant drugs, warfarin approved in 1954 bears a benzo-α-pyrone (coumarin) nucleus. The widely investigated psoriasis drugs, methoxsalen, and trioxsalen, also contain a benzo-α-pyrone nucleus. Benzo-γ-pyrone (chromone) containing drugs, cromoglic acid, and pranlukast were approved as treatments for asthma in 1982 and 2007, respectively. Numerous other small molecules with a benzopyrone core are under clinical investigation. The present review discusses the discovery, absorption, distribution, metabolism, excretion properties, and synthetic approaches for the Food and Drug Administration-approved and clinical-stage benzopyrone class of compounds. The role of the pyrone core in biological activity has also been discussed. The present review unravels the potential of benzopyrone core in medicinal chemistry and drug development.

Suppression of Mast Cell Activation by GPR35: GPR35 Is a Primary Target of Disodium Cromoglycate

Mast cell stabilizers, including disodium cromoglycate (DSCG), were found to have potential as the agonists of an orphan G protein-coupled receptor, GPR35, although it remains to be determined whether GPR35 is expressed in mast cells and involved in suppression of mast cell degranulation. Our purpose in this study is to verify the expression of GPR35 in mast cells and to clarify how GPR35 modulates the degranulation. We explored the roles of GPR35 using an expression system, a mast cell line constitutively expressing rat GPR35, peritoneal mast cells, and bone marrow-derived cultured mast cells. Immediate allergic responses were assessed using the IgE-mediated passive cutaneous anaphylaxis (PCA) model. Various known GPR35 agonists, including DSCG and newly designed compounds, suppressed IgE-mediated degranulation. GPR35 was expressed in mature mast cells but not in immature bone marrow-derived cultured mast cells and the rat mast cell line. Degranulation induced by antigens was significantly downmodulated in the mast cell line stably expressing GPR35. A GPR35 agonist, zaprinast, induced a transient activation of RhoA and a transient decrease in the amount of filamentous actin. GPR35 agonists suppressed the PCA responses in the wild-type mice but not in the GPR35-/- mice. These findings suggest that GPR35 should prevent mast cells from undergoing degranulation induced by IgE-mediated antigen stimulation and be the primary target of mast cell stabilizers. SIGNIFICANCE STATEMENT: The agonists of an orphan G protein-coupled receptor, GPR35, including disodium cromoglycate, were found to suppress degranulation of rat and mouse mature mast cells, and their antiallergic effects were abrogated in the GPR35-/- mice, indicating that the primary target of mast cell stabilizers should be GPR35.

Clinical challenge for gastroenterologists–Gastrointestinal manifestations of systemic mastocytosis: A comprehensive review

Mastocytosis is a rare and heterogeneous disease characterized by various clinical and biological features that affect different prognoses and treatments. The disease is usually divided into 2 principal categories: cutaneous and systemic disease (SM). Clinical features can be related to mast cell (MC) mediator release or pathological MC infiltration. SM is a disease often hard to identify, and the diagnosis is based on clinical, biological, histological, and molecular criteria with different specialists involved in the patient’s clinical work-up. Among all manifestations of the disease, gastrointestinal (GI) symptoms are common, being present in 14%-85% of patients, and can significantly impair the quality of life. Here we review the data regarding GI involvement in SM, in terms of clinical presentations, histological and endoscopic features, the pathogenesis of GI symptoms, and their treatment.

Cardiac Mast Cells: A Two-Head Regulator in Cardiac Homeostasis and Pathogenesis Following Injury

Cardiac mast cells (CMCs) are multifarious immune cells with complex roles both in cardiac physiological and pathological conditions, especially in cardiac fibrosis. Little is known about the physiological importance of CMCs in cardiac homeostasis and inflammatory process. Therefore, the present review will summarize the recent progress of CMCs on origin, development and replenishment in the heart, including their effects on cardiac development, function and ageing under physiological conditions as well as the roles of CMCs in inflammatory progression and resolution. The present review will shed a light on scientists to understand cardioimmunology and to develop immune treatments targeting on CMCs following cardiac injury.

Cromolyn Sodium differentially regulates human mast cell and mouse leukocyte responses to control allergic inflammation

BACKGROUND

Cromolyn Sodium (CS) has been used in the past as an anti-allergy drug owing to its mast cell (MC) stabilizing properties that impair histamine release. However, additional mechanisms for its clinical actions are likely and might help to identify new roles for MCs and leukocytes in regulating inflammation. Here, using human cord blood-derived MCs (CBMCs), murine bone marrow-derived MCs (BMMCs) and eosinophils (BMEos), and in vivo mouse models of allergic inflammation (AI), additional actions of CS on MCs were determined.

METHODS

The in vitro effects of CS on IgE-activated human and mouse MCs were assessed by measuring the levels of pro-inflammatory (tryptase, LTC₄, IL-8, CD48) and pro-resolution effectors (IL-10, CD300a, Annexin A1) before and after CS treatment. The in vivo effects of daily CS injections on parameters of inflammation were assessed using mouse models of allergic peritonitis (AP) (Ovalbumin/Alum- or Ovalbumin/S. aureus enterotoxin B) and allergic airways inflammation (AAI) (house dust mite (HDM)).

RESULTS

In vitro, CS did not affect pro-inflammatory effectors but significantly increased the anti-inflammatory/pro-resolution CD300a levels and IL-10 release from IgE-activated CBMCs. BMMCs were not affected by CS. In vivo, CS injections decreased total cell and Eos numbers in the peritoneal cavity in the AP models and bronchoalveolar lavage and lungs in the AAI model. CS reduced EPX release from PAF-activated BMEos in vitro, possibly explaining the in vivo findings.

CONCLUSION

Together, these results demonstrate immunomodulatory actions for CS in AI that are broader than only MC stabilization.

The Nose as a Route for Therapy: Part 1. Pharmacotherapy

This article reviews nasal structure and function in the light of intranasal pharmacotherapy. The nose provides an accessible, fast route for local treatment of nose and sinus diseases, with lower doses than are necessary systemically and few adverse effects. It can also be used for other medications as it has sufficient surface area protected from local damage by mucociliary clearance, absence of digestive enzymes, responsive blood flow, and provides a rapid route to the central nervous system.

Modulation of Allergic Inflammation in the Nasal Mucosa of Allergic Rhinitis Sufferers With Topical Pharmaceutical Agents

Allergic rhinitis (AR) is a chronic upper respiratory disease estimated to affect between 10 and 40% of the worldwide population. The mechanisms underlying AR are highly complex and involve multiple immune cells, mediators, and cytokines. As such, the development of a single drug to treat allergic inflammation and/or symptoms is confounded by the complexity of the disease pathophysiology. Complete avoidance of allergens that trigger AR symptoms is not possible and without a cure, the available therapeutic options are typically focused on achieving symptomatic relief. Topical therapies offer many advantages over oral therapies, such as delivering greater concentrations of drugs to the receptor sites at the source of the allergic inflammation and the reduced risk of systemic side effects. This review describes the complex pathophysiology of AR and identifies the mechanism(s) of action of topical treatments including antihistamines, steroids, anticholinergics, decongestants and chromones in relation to AR pathophysiology. Following the literature review a discussion on the future therapeutic strategies for AR treatment is provided.

The controversial role of mast cells in fibrosis

Fibrosis is a medical condition characterized by an excessive deposition of extracellular matrix compounds such as collagen in tissues. Fibrotic lesions are present in many diseases and can affect all organs. The excessive extracellular matrix accumulation in these conditions can often have serious consequences and in many cases be life-threatening. A typical event seen in many fibrotic conditions is a profound accumulation of mast cells (MCs), suggesting that these cells can contribute to the pathology. Indeed, there is now substantialv evidence pointing to an important role of MCs in fibrotic disease. However, investigations from various clinical settings and different animal models have arrived at partly contradictory conclusions as to how MCs affect fibrosis, with many studies suggesting a detrimental role of MCs whereas others suggest that MCs can be protective. Here, we review the current knowledge of how MCs can affect fibrosis.

Human mast cells and basophils-How are they similar how are they different?

Mast cells and basophils are key contributors to allergies and other inflammatory diseases since they are the most prominent source of histamine as well as numerous additional inflammatory mediators which drive inflammatory responses. However, a closer understanding of their precise roles in allergies and other pathological conditions has been marred by the considerable heterogeneity that these cells display, not only between mast cells and basophils themselves but also across different tissue locations and species. While both cell types share the ability to rapidly degranulate and release histamine following high-affinity IgE receptor cross-linking, they differ markedly in their ability to either react to other stimuli, generate inflammatory eicosanoids or release immunomodulating cytokines and chemokines. Furthermore, these cells display considerable pharmacological heterogeneity which has stifled attempts to develop more effective anti-allergic therapies. Mast cell- and basophil-specific transcriptional profiling, at rest and after activation by innate and adaptive stimuli, may help to unravel the degree to which these cells differ and facilitate a clearer understanding of their biological functions and how these could be targeted by new therapies.

The Anti-allergic Cromones: Past, Present, and Future

The anti-allergic cromones were originally synthesized in the 1960s by Fisons Plc, and the first drug to emerge from this program, disodium cromoglycate was subsequently marketed for the treatment of asthma and other allergic conditions. Whilst early studies demonstrated that the ability of the cromones to prevent allergic reactions was due to their 'mast cell stabilizing' properties, the exact pharmacological mechanism by which this occurred, remained a mystery. Here, we briefly review the history of these drugs, recount some aspects of their pharmacology, and discuss two new explanations for their unique actions. We further suggest how these findings could be used to predict further uses for the cromones.

Leukotriene Receptor Antagonists and Antiallergy Drugs

As one of the candidates of the therapeutic strategy for asthma in addition to inhaled corticosteroids (ICS), leukotriene receptor antagonists (LTRAs) are known to be useful for long-term management of asthma patients complicated by allergic rhinitis (AR) or exercise-induced asthma (EIA). Currently available LTRAs are pranlukast hydrate, zafirlukast, and montelukast. These LTRAs have a bronchodilator action and inhibit airway inflammation, resulting in a significant improvement of asthma symptoms, respiratory function, inhalation frequency of as-needed inhaled β2-agonist, airway inflammation, airway hyperresponsiveness, dosage of ICSs, asthma exacerbations, and patients' QOL. Although cys-LTs are deeply associated with the pathogenesis of asthma, LTRAs alone are less effective compared with ICS. However, the effects of LTRAs in combination with ICS are the same as those of LABAs in combination with ICS in steroid-naïve asthmatic patients. Concerning antiallergy drugs other than LTRAs, some mediator-release suppressants, H1 histamine receptor antagonists (H1RAs), thromboxane A2 (TXA2) inhibitors/antagonists, and Th2 cytokine inhibitor had been used mainly in Japan until the late 1990s. However, the use of these agents rapidly decreased after ICS/long acting beta agonist (LABA) combination was introduced and recommended for the management of asthma in the early 2000s. The effectiveness of other antiallergic agents on asthma management seems to be quite limited, and the safety of oral antiallergic agents has not been demonstrated in fetuses during pregnancy. Further effectiveness studies are needed to determine the true value of these orally administered agents in combination with ICS as an anti-asthma treatment.

Pharmacotherapy for the treatment of asthma: current treatment options and future directions

BACKGROUND

Asthma is a prevalent disease characterized by chronic inflammatory changes of the airway and marked by airway hyperresponsiveness, edema, and excess mucus production. Management of the disease has focused upon reversing the early airway changes and limiting the late effects of airway remodeling. Several classes of medications are available for the effective treatment and long-term control of asthma and novel therapeutic options are in development that hold promise in improving patient outcome.

METHODS

A review of updated guidelines and current literature was conducted to identify available pharmacologic treatments of asthma and determine future directions in development of novel therapeutic options.

RESULTS

Inhaled corticosteroids are the most effective medications in long-term asthma control with adjunct medications such as β2-agonists, which can provide symptomatic relief. Other classes of asthma control medications including anticholinergics, cromolyns, and leukotriene receptor modifiers can also be used to develop an effective management strategy based on asthma severity.

CONCLUSION

Several classes of medications are available for the effective management of asthma. Inhaled corticosteroids play a central role in control of inflammation and several other adjuncts are available to tailor therapy to the patient's symptoms. New therapeutic options that target downstream inflammatory mediators can provide increased efficacy while limiting side effects.

Mast cell stabilisers

Mast cells play a critical role in type 1 hypersensitivity reactions. Indeed, mast cell mediators are implicated in many different conditions including allergic rhinitis, conjunctivitis, asthma, psoriasis, mastocytosis and the progression of many different cancers. Thus, there is intense interest in the development of agents which prevent mast cell mediator release or which inhibit the actions of such mediators once released into the environment of the cell. Much progress into the design of new agents has been made since the initial discovery of the mast cell stabilising properties of khellin from Ammi visnaga and the clinical approval of cromolyn sodium. This review critically examines the progress that has been made in the intervening years from the design of new agents that target a specific signalling event in the mast cell degranulation pathway to those agents which have been developed where the precise mechanism of action remains elusive. Particular emphasis is also placed on clinically used drugs for other indications that stabilise mast cells and how this additional action may be harnessed for their clinical use in disease processes where mast cells are implicated.

Comorbidity between depression and asthma via immune-inflammatory pathways: a meta-analysis

BACKGROUND

Depression is often present in patients with asthma and vice versa. In this review, we aimed to summarize reports on the comorbidity of depression and asthma, and to seek evidence that the biological mechanisms of allergy may have an important role linking asthma and depression.

METHOD

To explore the relationship and pathway underpinning this comorbidity, we reviewed medical articles and undertook a meta-analysis of epidemiological studies on (i) incidence of asthma in patients with depression; (ii) morbidity of depression in patients with asthma; (iii) concentration of cytokines in depressed subjects.

RESULTS

High level of comorbidity of asthma and depression was consistently demonstrated in 10 studies of patients with asthma and four studies of patients with depression. In search of biological connection of the two illnesses, thirty-eight studies were included for Meta-analyses examining differences in allergy related cytokines between patients with depression and non-depressive subjects. In people with depression, concentration of monocytes related cytokines such as IL-1 (1.56ng/mL, 95% CI: 0.00-3.12, p=0.05) was significantly higher than that in non-depressive control subjects. At the same time, some other inflammatory factors including IL-4 (5.77pg/mL, 95% CI: 2.34-9.21, p=0.00010), IL-6 (1.44ng/mL, 95% CI: 1.05-1.82, p<0.00001) and TNF-α(3.01ng/mL, 95% CI: 1.76-4.26, p<0.00001) were extremely significantly higher in depressed people compared with the controls. There was no significant differences of the T cell related cytokine levels, IFN-γ (-0.16ng/mL, 95% CI: -0.85-7.73, p=0.97), accompanied with IL-10 (0.67ng/mL, 95% CI: -0.84-2.18, p=0.38) between depressive and non-depressive groups.

CONCLUSIONS

The varying levels of certain cytokines play an important role in arousing and remitting asthma and depression. That suggests inflammatory response could be a common pathway adjusting both depression and asthma.

Targeting mast cells in inflammatory diseases

Although mast cells have long been known to play a critical role in anaphylaxis and other allergic diseases, they also participate in some innate immune responses and may even have some protective functions. Data from the study of mast cell-deficient mice have facilitated our understanding of some of the molecular mechanisms driving mast cell functions during both innate and adaptive immune responses. This review presents an overview of the biology of mast cells and their potential involvement in various inflammatory diseases. We then discuss some of the current pharmacological approaches used to target mast cells and their products in several diseases associated with mast cell activation.

The Use of Antiallergic and Antiasthmatic Drugs in Viral Infections of the Upper Respiratory Tract

Despite their frequency, upper respiratory tract infections (URTIs) constitute an area with few, if any, effective treatment remedies. Asthma and airway allergies share similar pathogenetic mechanisms to URTIs and it is not surprising, therefore, that agents used to treat allergic disorders have also been studied in URTIs. Their possible effects, limitations and hypothetical modes of action in URTIs are reviewed. In controlled clinical trials of satisfactory scientific standard, symptom reductions in both experimental rhinovirus infections and natural colds have occurred with topical anticholinergics, oral antihistamines and topical chromones. Future treatment alternatives for URTIs may include the intranasal anticholinergic ipratropium bromide, new nonsedating antihistamines and sodium cromoglycate (cromolyn sodium). The latter has a record of safety and an absence of adverse effects that would make it an attractive alternative for this common but not particularly serious condition in otherwise healthy individuals.

Management of asthma during pregnancy

Asthma is an inflammatory lung condition that is the most common chronic disease affecting pregnancy. The changes in pulmonary physiology during pregnancy include increased minute ventilation, decreased functional residual capacity, increased mucus production, and airway mucosa hyperemia and edema. Pregnancy is also associated with a physiological suppression of the immune system. Many studies have described the heterogeneous immune system response in women with asthma during pregnancy, which partly explains why asthma has been shown to worsen, improve, or remain stable in equal proportions of women during pregnancy. Asthma may be associated with poor maternal and fetal outcomes. However, better maternal and fetal outcomes are observed with better asthma control. Asthma controller medications are generally thought to be safe during pregnancy, but limited data are available for some of the medicines. Newer medications like omalizumab open avenues for the treatment of asthma, but also pose a challenge, as there is limited experience with their use. Therefore, a multidisciplinary approach, including obstetricians, asthma specialists, and pediatricians should collaborate with the patient to carefully weigh the risks and benefits to determine an optimal management plan for each individual patient. The aim of this review article is to summarize the most recent literature about the immunological changes that occur during pregnancy, physiological and clinical implications of asthma on pregnancy, and asthma management and medication use in pregnant women.

Cromoglycate and nedocromil: influence on airway reactivity

Although basic mechanisms of bronchial hyper-responsiveness (BHR) are still incompletely understood, inflammation of airways is likely to play a fundamental role in modulating BHR in patients with asthma. The involvement of several inflammatory cells (eosinophils, mast cells, lymphocytes, neutrophils, macrophages and platelets) and of bioactive mediators secreted by these cells in the pathogenesis of asthma is well documented. Sodium cromoglycate and nedocromil sodium are two pharmacological agents which have anti-allergic and anti-inflammatory properties. Their clinical effectiveness in mild to moderate asthma, and the capacity to reduce BHR under different natural and experimental conditions, make them valuable drugs for maintenance therapy in patients with asthma.

The actual role of sodium cromoglycate in the treatment of asthma--a critical review

INTRODUCTION

Despite international consensus and clearly written guidelines urging wider use of corticosteroids or combinations of inhaled short- and long-acting β-agonists (SABA and LABA) and corticosteroids in persistent asthma, prescribing patterns and compliance rates fall far short of recommendations.

OBJECTIVES

The failure to use steroids more aggressively is due, in part, to their side effects, even with inhaled forms of the drug. There is a role for expanded use of sodium cromolyn in asthma. Its potent anti-inflammatory effects, lack of side effects, and acceptable dosing and method of delivery, as well as its special role in exercise-induced asthma, make it a very suitable choice in the initial therapy for control of asthma.

CONCLUSION

Compared to SABA and LABA, cromoglycates alone are unsuspicious of being used to enhance physical performance.

The two faces of mast cells in food allergy and allergic asthma: the possible concept of Yin Yang

The purpose of this review is to discuss the role of mast cells in allergic inflammation. We have focused on inflammation associated with allergic asthma and food allergy. Mast cells are 'first line of defense' innate/adaptive immune cells and are widely distributed in tissues in surfaces exposed to the environment. Especially in allergic settings mast cells are extensively studied, as they can be activated to release a wide range of mediators by allergen-IgE specific triggers. In addition, in allergic inflammation mast cells can also be activated non-allergic triggers. Recent studies revealed that mast cells, besides the classical role of pro-inflammatory effector cell, have also emerged as modulators of allergic sensitization and down-regulators of allergic inflammation. Therefore, mast cells can be regarded as 'Ying Yan' modulators in allergic responses in intestinal tract and airways. This article is part of a Special Issue entitled: Mast Cells in Inflammation.

Japanese pediatric guidelines for the treatment and management of bronchial asthma 2008

Abstract The fourth version of the Japanese Pediatric Guidelines for the Treatment and Management of Bronchial Asthma 2008 (JPGL 2008) was published by the Japanese Society of Pediatric Allergy and Clinical Immunology in December 2008. In JPGL 2008, the recommendations were revised on the basis of the JPGL 2005. The JPGL 2008 is different to the Global Initiative for Asthma guideline in that it contains the following items: a classification system of asthma severity; recommendations for long-term management organized by age; a special mention of infantile asthma; and an emphasis on prevention and early intervention. Here we show a summary of the JPGL 2008 revising our previous report concerning JPGL 2005.

The effect of asthma therapeutics on signalling and transcriptional regulation of airway smooth muscle function

SCOPE OF THE REVIEW

Our knowledge of the multifunctional nature of airway smooth muscle (ASM) has expanded rapidly in the last decade, but the underlying molecular mechanisms and how current therapies for obstructive airway diseases, such as asthma and chronic obstructive pulmonary disease (COPD), affect these are still being elucidated. Our current knowledge has built on the pharmacology of human ASM contraction and relaxation established prior to that and which is reviewed in detail elsewhere in this issue. The advent of methods to isolate and culture ASM cells, especially human ASM cells, has made it possible to study how they may contribute to airway remodelling through their synthetic, proliferative, and migratory capacities. Now the underlying molecular mechanisms of ASM growth factor secretion, extracellular matrix (ECM) production, proliferation and migration, as well as contraction and relaxation, are being determined. A complex network of signalling pathways leading to gene transcription in ASM cells permits this functional plasticity in healthy and diseased airways. This review is an overview of the effects of current therapies, and some of those in development, on key signalling pathways and transcription factors involved in these ASM functions.

Effects of a new nutraceutical ingredient on allergen-induced sulphidoleukotrienes production and CD63 expression in allergic subjects

Allergic diseases represent conditions affecting millions of individuals across the world. The objective of this study was to investigate the potential anti-allergic effects of a new nutraceutical ingredient, Pantescal (Bionap, Italy), contained in different food supplements. Pantescal is a mixture of plant extracts, such as Capparis spinosa, Olea europaea, Panax Ginseng and Ribes nigrum. The study was a randomized, double-blind, placebo controlled design. 60 patients allergic to common aeroallergens were chosen. Allergic patients were divided into two groups: one group was supplemented by Pantescal and the other, using a placebo formulation. Two in vitro tests were performed on blood samples taken from patients before and at 2 h, 2, 3 and 10 days after supplementation: cellular antigen stimulation test (CAST) was used to analyze the amount of sulphidoleukotrienes (SLT) production and flow-cytometric antigen stimulation test (FAST) to measure expression of basophil degranulation marker (CD63) was also performed. CAST showed that after 2 and 3 days, a slight decrease of SLT production was evident but only after 10 days did it become significant with a percentage of inhibition (P.I)=43.3%. FAST revealed that there were no statistical differences for the first 2 days after supplementation although there was an inhibitory trend in the supplemented patients. CD63 expression was significantly reduced after 10 days (P.I.=64.8%). This study suggests that Pantescal is effective in reducing allergic biomarkers such as CD63 protein and SLT in atopic subjects. The higher inhibitory effect on CD63 expression compared to SLT production allows us to hypothesize cell membrane stabilization as the main potential mechanism to explain the observed Pantescal protective effects.

New Japanese pediatric guidelines for the treatment and management of bronchial asthma

There have been a number of guidelines for asthma treatment published throughout the world. However, childhood asthma guidelines must be developed in consideration of the background of the individual countries. The second version of the Japanese Pediatric Guideline for the Treatment and Management of Bronchial Asthma 2002 (JPGL 2002) was published by the Japanese Society of Pediatric Allergy and Clinical Immunology (JSPACI) in November 2002, and was popular among Japanese physicians. After the publication of the JPGL, the incidence of pediatric asthma deaths decreased in Japan. In JPGL 2005 the recommendations were re-edited based on Global Initiative for Asthma (GINA) and the JPGL 2002. In comparison to the GINA guidelines, the JPGL 2005 include a classification system of asthma severity, recommendations for long-term management organized by age, a special mention of infantile asthma, and an emphasis on prevention and early intervention.

The role of mast cells in atopy: what can we learn from canine models? A thorough review of the biology of mast cells in canine and human systems

Mast cell research has largely focused on the role of these cells in the early phase of allergic reactions. However, their involvement may well extend beyond this stage, and even reach across nonallergic conditions. Mast cells from different sources have helped advance our knowledge of their biology. Although in vitro and in vivo research in this area has mainly focused on humans, such studies are limited by the extent to which cells from certain human tissues and/or human patients can be collected or studied. While rodents also provide valuable models with which to further our understanding of the behaviour of mast cells and their contribution to allergy, reported differences between human and murine mast cells, and, in some instances, the limitations of in vivo rodent models of mast cell-mediated allergic conditions, preclude their use. In this review, we introduce a relatively unknown mast cell population, that of the dog. Canine mast cells display many phenotypic and functional similarities with their human counterparts, and dogs develop spontaneous and induced allergic diseases that share clinical and pathophysiological features with the human condition. Therefore, the use of canine cells can shed light on the general role of mast cells, particularly in relation to allergic diseases given the potential of in vivo dog models within this field. Here we provide a detailed review of the data reported from in vitro and in vivo studies of canine mast cells, and compare them with results obtained in human systems. We also highlight direct evidence of the mast cell contribution to canine atopy. We conclude that the dog offers useful in vitro and in vivo models in which to investigate mast cell behaviour, and that its use should be considered when undertaking studies aimed either at elucidating the role of mast cells in health and disease, or at prescreening novel therapies prior to entry into man.

New targets for modifying mast cell activation in asthma

Mast cells play a central role in innate immunity and in orchestrating the asthmatic response. Current medication relies on beta-agonists to relieve bronchoconstriction and steroids to reduce inflammation. However, recently drugs such as leukotriene-receptor antagonists and anti-immunoglobulin E have come on to the market. In this paper, a number of potential targets for modifying mast cell activation in asthma are reviewed. Some are already under study, including clinical trials (eg, tryptase inhibitors); others are more speculative (eg, inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A reductase activity). In each case, where data are available, the action of the agents on human lung mast cells is described.

Effects of nebulized sodium cromoglycate on adult patients with severe refractory asthma

Many patients with severe refractory asthma, which is insufficiently controlled by additional high-dose of inhaled corticosteroids, require oral corticosteroids and/or immunosuppressant. Clinicians should seek for suitable medications, for its' chronic use may induce high risk of side effects. The purpose of this study was to evaluate the efficacy and safety of nebulized sodium cromoglycate (3-4 times/day) in adult severe asthmatic patients with poorly controlled asthmatic symptoms, despite treatments with high-dose inhaled corticosteroids. Adult patients with severe asthma (n=251) were enrolled in a randomized clinical trial at 30 medical centers in Japan. Isotonic saline was used as placebo. The study was conducted for 10 weeks; with initial 2 weeks of observation followed by 8 weeks of treatments. Efficacy was primarily evaluated based on improvements in morning peak expiratory flow after treatment. All patients who applied inhalation of nebulized sodium cromoglycate (SCG group) or saline (Controls) were treated with high-dose of inhaled corticosteroids (median of beclomethasone dipropionate equivalent dose: 1600 microg/days) and second-line control therapy including oral corticosteroids. There was no significant difference in morning peak expiratory flow between SCG group and controls. However, when patients were stratified into atopic and non-atopic groups, morning peak expiratory flow had significantly improved in the atopic SCG group compared to atopic Controls. Additional inhalation of nebulized sodium cromoglycate with inhaled corticosteroids is effective even in patients with severe atopic asthma. This finding shows that nebulized sodium cromoglycate is expected to be new second-line therapeutic option in severe asthma.

Intratracheal dosing with disodium cromoglycate inhibits late asthmatic response by attenuating eicosanoid production in guinea pigs

Disodium cromoglycate is an anti-asthmatic drug that has mast cell-stabilizing effects and other anti-inflammatory effects. However, the mechanisms of its anti-inflammatory effects are unclear. In this study, we evaluated effects of disodium cromoglycate on eosinophilia, early and late asthmatic responses, and production of arachidonic acid metabolites in guinea pig lungs. Guinea pigs were alternately sensitized and challenged by exposure to mists of ovalbumin+Al(OH)(3) and ovalbumin, respectively. Disodium cromoglycate (0.5-2 mg/0.1 ml/animal) administered intratracheally before the fifth challenge dose-dependently inhibited asthmatic response, but early asthmatic response was not affected. Disodium cromoglycate at 2 mg/animal potently suppressed increases in cysteinyl leukotrienes (CysLTs) and thromboxane A(2) in the lung during late asthmatic response. Eosinophilia was slightly reduced by disodium cromoglycate. The inhibitory effect of disodium cromoglycate on late asthmatic response is apparently due to inhibition of the release of arachidonic acid metabolites, some of which may be derived from eosinophils that infiltrate the lung.

Pharmacology of airway inflammation in asthma and COPD

The current asthma therapies are not cures and symptoms return soon after treatment is stopped even after long term treatment. Although inhaled glucocorticoids are highly effective in controlling airway inflammation in asthma, they are ineffective in the small group of patients with glucocorticoid-dependent and -resistant asthma. With very few exceptions, COPD is caused by tobacco smoking, and smoking cessation is the only truly effective treatment of COPD available. Current pharmacological treatment of COPD is unsatisfactory, as it does not significantly influence the severity of the disease or its natural course. Glucocorticoids are scarcely effective in COPD patients without concomitant asthma. Bronchodilators improves symptoms and quality of life, in COPD patients, but, with the exception of tiotropium, they do not significantly influence the natural course of the disease. Theophylline is the only drug which has been demonstrated to have a significant effect on airway inflammation in patients with COPD. Here we review the pharmacology of currently used antiinflammatory therapies for asthma and COPD and their proposed mechanisms of action. Recent understanding of disease mechanisms in severe steroid-dependent and -resistant asthma and in COPD, has lead to the development of novel compounds, which are in various stages of clinical development. We review the current status of some of these new potential drugs.

T-helper type 2 cell-directed therapy for asthma

Asthma is a chronic inflammatory disease of the bronchial airways. Current research in humans and animals suggests that T-helper type 2 (Th2) cells and the cytokines they elaborate cause many of the pathophysiologic abnormalities characteristic of the disease. We review the evidence implicating Th2 cells in asthma and discuss the cellular and molecular mechanisms that control Th2 cell differentiation in the respiratory tract. Based on the steps in Th cell development, we discuss how traditional therapies can modulate Th2 cell function. Furthermore, we explore newer immunomodulatory strategies to inhibit Th2 cell effects, including therapies that may block Th2 cell differentiation, neutralize cytokines, and redirect immune responses towards Th1 and away from Th2.

The pathobiologic implications for treatment. Old and new strategies in the treatment of chronic asthma

An increased understanding of the pathobiology of asthma has led to improved treatment for chronic asthma. This article discusses the old and new strategies of asthma therapy based on a pathobiologic approach. Therapeutic agents discussed include beta-adrenergic agonists, methylxanthines, corticosteroids, cromolyn, nedocromil, leukotriene modifiers, and new investigational agents.

Effects of sodium cromoglycate on cytokine production following antigen stimulation of a passively sensitized human lung model

BACKGROUND

Interleukin-5 (IL-5) and tumor necrosis factor-alpha (TNF-alpha) play key roles in bronchial asthma. Sodium cromoglycate (DSCG) and dexamethasone (Dex) are used in the treatment of asthma as anti-inflammatory agents.

OBJECTIVE

We investigated whether DSCG inhibited the expression of IL-5 and TNF-alpha mRNA and proteins from isolated human lungs, and compared these findings with those of Dex.

METHODS

Human lung specimens were passively sensitized with sera from atopic patients, then preincubated in the presence of DSCG (10(-3), 10(-4), 10(-5) M) or Dex (10(-6) M) for 2 hours. The specimens were stimulated with Dermatophagoides antigen, then cultured for 48 hours. The supernatant was collected 1, 2, 4, 8, 24, and 48 hours to measure IL-5 and TNF-alpha by enzyme-linked immunosorbent assay. mRNA expression was examined by reverse transcriptase-polymerase chain reaction (RT-PCR).

RESULTS

Tumor necrosis factor-alpha protein reached a peak level at 4 hours (156.57 +/- 18.29 pg/mL). Dex decreased TNF-alpha protein to 31.86 +/- 4.67 pg/mL (P < .001). There was also a decrease of TNF-alpha protein to 107.43 +/- 14.25 pg/mL by 10(-4) MD SCG (P < .001). Antigenic stimulation also increased the release of IL-5 protein at 4 hours and the peak level was observed at 24 hours (150.29 +/- 19.12 pg/mL). Dex decreased IL-5 protein to 28.57 +/- 5.27 pg/mL (P < .0001), 10(-4) M DSCG also decreased to 111.57 +/- 15.28 pg/mL (P < .05). RT-PCR analysis showed persistence of IL-5 and TNF-alpha mRNA expression from 1 to 24 hour after antigen stimulation. Dex but not DSCG inhibited IL-5 and TNF-alpha mRNA levels.

CONCLUSION

Our results showed that DSCG significantly inhibited IL-5 and TNF-alpha production by human lung specimens, suggesting that it acts as an anti-inflammatory agent.

Effects of inhaled corticosteroids and inhaled cromolyn sodium on urinary growth hormone excretion in asthmatic children

Over the past few years there has been an increasing awareness that asthma is a chronic inflammatory airways disease. The current therapeutic strategies for treating asthma focus on suppressing the inflammatory process by using cromones or inhaled corticosteroids (ICS). The beneficial effects of ICS in asthma are now well known, but its detrimental effect on linear growth remains a controversial issue. The aim of this open label, nonrandomized, cross-sectional, one-time study was to determine the influence of these drugs on urinary growth hormone (U-GH) levels in prepubertal asthmatic children. U-GH levels were measured in 47 prepubertal asthmatic children who had been treated for at least 6 months with either ICS (beclomethasone or budesonide at a mean daily dose of 360 microg) or with 80 mg daily dose of cromolyn sodium (CrS). There were also nine healthy children who served as a control. These three groups of children were matched for age and gender ratio. The mean level of U-GH in the CrS-treated group was 2.94 +/- 0.96 ng/night; this was significantly higher compared to the mean level of the ICS-treated group (1.99 +/- 0.83 ng/night; P < 0.001) and to the mean level of the control group (1.98 +/- 0.39 ng/night; P < 0.006). There was no significant difference between the mean level of U-GH in the group treated by ICS and the controls (P < 0.9). These results show that the mean levels of U-GH secretion of the children who were treated by CrS for 6 months was significantly increased, compared to the mean U-GH level of the ICS-treated group and the controls. The mean U-GH levels in the last two groups showed no statistically significant difference.

Role of intestinal mast cells in modulating gastrointestinal pathophysiology

OBJECTIVE

This article reviews the current understanding of the pathophysiologic role of intestinal mast cells.

DATA SOURCE

Up to date English language publications on mast cell characteristics, heterogeneity and functions were used. Recent articles were used to develop and extend novel concepts about the role of intestinal mast cells.

STUDY SELECTION

Reference sources were selected because of their pertinence to the pathophysiological effects of mast cells in intestinal hypersensitivity. Recent publications on the following topics were emphasized: mast cell proteases in intestinal anaphylaxis; effects of nitric oxide in gastrointestinal pathophysiology; involvement of cytokines derived from mast cells in tissue damage and repair.

RESULTS

Mast cells are clearly implicated in the pathology of intestinal disease. Growing evidence suggests physiological roles for mast cells in the protection of tissues from inflammatory damage, and in intestinal maturation. Mast cells can release cytokines, such as tumour necrosis factor-alpha and interleukin-10, which were originally thought to contribute to inflammatory damage, but which may also have anti-inflammatory properties. Interestingly, mast cell function can be regulated by nitric oxide, and mast cells themselves are sources of this important mediator. Nitric oxide has protective as well as detrimental effects in the intestine.

CONCLUSIONS

Intestinal mast cells have physiologic regulatory effects in addition to their pathologic effects. However, relatively little is known about the mechanisms of these regulatory effects. Mast cells are likely in an ongoing fluctuating balance between physiological functions and pathological effects in normal individuals. Poorly known factors can create an imbalance and lead to pathologic reactions.

Contractile responses of proximal and distal trachea segments isolated from rats subjected to immunological stimulation: role of connective tissue mast cells

1. Anaphylaxis-induced contractions of proximal and distal tracheal segments isolated from 14-day ovalbumin (OA)-sensitized rats were studied. 2. OA-induced contractions in distal segments were significantly greater than those observed in proximal segments. 3. Pretreatment of the rats with compound 48/80 or with sodium cromoglycate (SCG) aerosolization significantly reduced OA-induced contractions of trachea distal segments, whereas the contractions of proximal segments were reduced only by compound 48/80. 4. Mepacrine reduced and indomethacin increased the OA-induced contractions in all tracheal segments. Nor-dihydroguaiaretic acid increased the OA-induced contractions in distal tracheal segments, whereas dazoxiben inhibited the contractions in these same segments; neither of these drugs had any effect on the contractions in proximal tracheal segments. 5. The depletion of connective tissue mast cells and subsequent in vitro treatment with indomethacin increased the OA-induced contractions in both segments. 6. We conclude that the contractions of tracheal muscle from OA-sensitized rats depends on the topographic and anatomical origin of the airway tissue. 7. Mediators released by connective tissue mast cells in proximal and distal segments play a pivotal role in this response and may account for variations in the intensity of contraction seen after the addition of OA.

Inhibition of histamine release by nedocromil sodium reduces exercise-induced hypoxemia in master athletes

During exercise in highly-trained older master athletes (MA), the impairment of pulmonary gas exchanges has been shown to be associated with a concomitant increase in histamine release (2). To determine the role of the histamine released (% H) during exercise-induced hypoxemia, seven MA (age 63.2 yr +/- 1.9), all of whom were known to develop exercise-induced hypoxemia, performed two maximal incremental exercise tests at a one-month interval after administration of nedocromil sodium (which inhibits histamine and other mediator release) or placebo in random double-blind order. During exercise testing, blood samples for arterial blood gas analysis and histamine assay were drawn at rest, exercise and recovery. Nedocromil sodium induced an inhibition in % H (0.57 +/- 0.03 at maximal load (Pmax) with placebo vs 0.24 +/- 0.02 with nedocromil sodium) linked with an improvement of pulmonary gas exchange (PaO2: 71.1 +/- 1.4 at Pmax with placebo vs 83.4 +/- 3 with nedocromil sodium; D(Ai-a)O2: 37.5 +/- 1.4 at Pmax vs 19.1 +/- 3.1, respectively). These results confirm the link established between the increase in histamine and exercise-induced hypoxemia in master athletes.

Mechanisms of inhibition of IgE synthesis by nedocromil sodium: nedocromil sodium inhibits deletional switch recombination in human B cells

IgE synthesis requires IL-4 and a T cell-B cell interaction that involves the B-cell antigen CD40 and its ligand expressed on activated T cells. Nedocromil sodium (NS), an effective prophylactic agent in asthma, inhibits IgE synthesis by human B cells. In this report we examined the mechanisms of this inhibition. NS targeted the B cells because it inhibited IgE synthesis induced by anti-CD40 and IL-4 in highly purified B cells (greater than 98% CD19+). NS had no effect on the induction of epsilon-germline transcripts by IL-4 but strongly inhibited CD40-mediated S mu --> S epsilon deletional switch recombination. The effect of NS was not specific for CD40 because it inhibited IgE synthesis in B cells stimulated with hydrocortisone plus IL-4. Moreover, the effect of NS was not specific for IgE because it inhibited CD40/IL-4-driven IgG4 synthesis by B cells sorted for lack of surface expression of IgG4. NS caused only modest inhibition of spontaneous IgE synthesis by B cells from patients with hyper-IgE syndrome, suggesting that it has little effect on B cells that have already undergone isotype switching. These results strongly suggest that NS inhibits IgE isotype switching by inhibiting deletional switch recombination and that NS has a novel potential mechanism for the prevention of asthma and other allergic diseases.

Clinical implications of the pharmacological profile of Tilarin

The pharmacological activity of nedocromil sodium is extensive and the compound should affect a variety of inflammatory processes by preventing activation of the involved cells or blocking release of their mediators. Some in vitro actions of nedocromil sodium are particularly relevant to the mechanisms of allergic rhinitis, and the response of the nasal epithelium to pollutants such as ozone. The effects of nedocromil sodium on mucosal mast cells, eosinophils, sensory nerves and nasal epithelial cells can each be linked to its potential clinical effectiveness by our own biopsy studies from patients with active allergic rhinitis. Nedocromil sodium has been shown to modulate production of a number of powerful cytokines, such as GM-CSF and TNF alpha, which are produced by the human nasal epithelium, as well as by involved inflammatory cells and lymphocytes, and which orchestrate the inflammatory response to allergen or to pollutant provocation. So, in addition to inhibiting activated mast cells and eosinophils, nedocromil sodium acts on the nasal epithelium itself to prevent further accumulation of these cells and thus to break the inflammatory chain of events. On this evidence of its preclinical activity, nedocromil sodium promises to become a very useful topical treatment for allergic rhinitis.