Beta2-agonists potentiate corticosteroid-induced neutrophil survival.
Neutrophils are considered to play a role in the pathogenesis of chronic obstructive pulmonary disease (COPD) and severe asthma. Recent guidelines recommend the use of a combination of inhaled corticosteroids (ICS) and long-acting beta2-agonists (LABA) in the treatment of COPD with exacerbations and asthma not adequately controlled by ICS alone. LABA have been proposed to have a synergistic effect with corticosteroids by activating glucocorticoid receptors. The aim of this study was to investigate the effect of beta2-agonists on the inhibitory effects of corticosteroids on human neutrophil apoptosis. In addition, the effects of beta2-agonists on spontaneous neutrophil apoptosis and on GM-CSF- and LTB4-afforded survival were also evaluated. Neutrophils were isolated from human blood under sterile conditions and cultured for 16 hours. Apoptosis was assessed by relative DNA fragmentation assay. Morphological analysis was used as a control method to confirm the occurrence of apoptosis. Salbutamol, formoterol and salmeterol prolonged the lifespan of budesonide- and fluticasone propionate-treated neutrophils by inhibiting apoptosis. Formoterol and salbutamol partly reversed the inhibitory effect of GM-CSF on neutrophil apoptosis. In contrast, the effects of beta(2)-agonists on spontaneous neutrophil apoptosis and on LTB(4)-afforded survival were negligible. beta2-agonists potentiate corticosteroid-induced neutrophil survival at clinically relevant drug concentrations. Whether these effects translate into clinically relevant changes in lung neutrophil numbers remains to be demonstrated.
The Immunopharmacology Research Group, Medical School, University of Tampere and Research Unit, Tampere University Hospital, Tampere, Finland. heli.perttunen@uta.fi
Heli
H
Perttunen
Eeva
E
Moilanen
Xianzhi
X
Zhang
Peter J
PJ
Barnes
Hannu
H
Kankaanranta
D000318:Adrenergic beta-Agonists / Q000494:pharmacology*; D000420:Albuterol / Q000031:analogs & derivatives* / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D018929:Cell Culture Techniques; D002470:Cell Survival / Q000187:drug effects; D004983:Ethanolamines / Q000494:pharmacology*; D000068759:Formoterol Fumarate; D005938:Glucocorticoids / Q000494:pharmacology*; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D006801:Humans; D007975:Leukotriene B4; D009504:Neutrophils / Q000187:drug effects* / Q000502:physiology; D000068299:Salmeterol Xinafoate
D000318:Adrenergic beta-Agonists; D004983:Ethanolamines; D005938:Glucocorticoids; D007975:Leukotriene B4; D000068299:Salmeterol Xinafoate; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D000420:Albuterol; D000068759:Formoterol Fumarate