Stimulus-selective regulation of human mast cell gene expression, degranulation and leukotriene production by fluticasone and salmeterol.

Adriana Catalli,Brian P Tancowny,Marianna Kulka,Robert P Schleimer,Victor Karpov,Levente E Erdos,Stephania Ann Cormier

doi:10.1371/journal.pone.0096891

Adriana Catalli, Brian P Tancowny + Show 5 more

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https://doi.org/10.1371/journal.pone.0096891

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Abstract

Despite the fact that glucocorticoids and long acting beta agonists are effective treatments for asthma, their effects on human mast cells (MC) appear to be modest. Although MC are one of the major effector cells in the underlying inflammatory reactions associated with asthma, their regulation by these drugs is not yet fully understood and, in some cases, controversial. Using a human immortalized MC line (LAD2), we studied the effects of fluticasone propionate (FP) and salmeterol (SM), on the release of early and late phase mediators. LAD2 cells were pretreated with FP (100 nM), SM (1 µM), alone and in combination, at various incubation times and subsequently stimulated with agonists substance P, C3a and IgE/anti-IgE. Degranulation was measured by the release of β-hexosaminidase. Cytokine and chemokine expression were measured using quantitative PCR, ELISA and cytometric bead array (CBA) assays. The combination of FP and SM synergistically inhibited degranulation of MC stimulated with substance P (33% inhibition compared to control, n = 3, P<.05). Degranulation was inhibited by FP alone, but not SM, when MC were stimulated with C3a (48% inhibition, n = 3, P<.05). As previously reported, FP and SM did not inhibit degranulation when MC were stimulated with IgE/anti-IgE. FP and SM in combination inhibited substance P-induced release of tumor necrosis factor (TNF), CCL2, and CXCL8 (98%, 99% and 92% inhibition, respectively, n = 4, P<.05). Fluticasone and salmeterol synergistically inhibited mediator production by human MC stimulated with the neuropeptide substance P. This synergistic effect on mast cell signaling may be relevant to the therapeutic benefit of combination therapy in asthma.

Highlights

Treatment of inflammation relies heavily on the use of glucocorticosteroids, which are presently the most effective drugs available for the management of many severe inflammatory diseases including asthma, rhinitis and chronic obstructive pulmonary disease (COPD), to name just a few [1,2,3,4]
fluticasone propionate (FP) and SM inhibited human mast cell degranulation To determine whether FP and SM inhibit human mast cell degranulation, LAD2 human mast cells were pretreated for 20 hr with FP (0.1 nM) and/or SM (10 nM), stimulated with substance P (SP), C3a or IgE/anti-IgE and the amount of degranulation was determined by measurement of b-hexosaminidase release (Fig. 1)
Initial experiments showed that FP and SM individually at low concentrations (0.1 nM and 10 nM respectively) had no effect on mast cell degranulation (Fig. 1), in combination they synergistically inhibited SP-induced degranulation. This effect was unique to SP-activated cells since C3aactivated mast cell degranulation was only inhibited by FP, and IgE-mediated degranulation was unaffected by either FP or SM

Summary

Introduction

Treatment of inflammation relies heavily on the use of glucocorticosteroids, which are presently the most effective drugs available for the management of many severe inflammatory diseases including asthma, rhinitis and chronic obstructive pulmonary disease (COPD), to name just a few [1,2,3,4]. Glucocorticoids and adrenergic hormones (epinephrine and norepinephrine) interact at both cellular and molecular levels to enhance each other’s actions during stress responses. This fact has been exploited in the development of drug preparations combining a glucocorticoid and a long acting beta adrenergic agonist (LABA) for the treatment of asthma [5,6,7]. The profound ability of glucocorticoids to inhibit allergic late phase responses (LPR) is not likely to be due to the inhibition of mast cell degranulation. Glucocorticoids inhibit the expression of cytokines by IgE/antigen-activated human mast cells and this may contribute to the ability of glucocorticoids to inhibit LPR [11,12]. Additional information is required regarding the effects of glucocorticoids on the release of inflammatory cytokines and chemokines by mast cells, especially given that cytokine production by mast cells is of great relevance to inflammatory disease

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