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ABSTRACT: Background
Aspirin-exacerbated respiratory disease (AERD) is an inflammatory condition of the respiratory tract and is characterized by overproduction of leukotrienes (LT) and large numbers of circulating granulocyte-platelet complexes. LT production can be suppressed by prostaglandin E(2) (PGE(2)) and the cyclic AMP-dependent protein kinase A (PKA).Objective
To determine if PGE(2)-dependent control of LT production by granulocytes is dysregulated in AERD.Methods
Granulocytes from well-characterized patients with and without AERD were activated ex vivo and subjected to a range of functional and biochemical analyses.Results
Granulocytes from subjects with AERD generated more LTB4 and cysteinyl LTs than did granulocytes from controls with aspirin-tolerant asthma and controls without asthma. When compared with controls, granulocytes from subjects with AERD had comparable levels of EP(2) protein expression and PGE(2)-mediated cAMP accumulation, yet were resistant to PGE(2)-mediated suppression of LT generation. Percentages of platelet-adherent neutrophils correlated positively with LTB4 generation and inversely with responsiveness to PGE(2)-mediated suppression of LTB(4). The PKA inhibitor H89 potentiated LTB4 generation by control granulocytes but was inactive in granulocytes from individuals with AERD and had no effect on platelet P-selectin induction. Both tonic PKA activity and levels of PKA catalytic gamma subunit protein were significantly lower in granulocytes from individuals with AERD relative to those from controls.Conclusions
Impaired granulocyte PKA function in AERD may lead to dysregulated control of 5-lipoxygenase activity by PGE(2), whereas adherent platelets lead to increased production of LTs, which contributes to the features of persistent respiratory tract inflammation and LT overproduction.
SUBMITTER: Laidlaw TM
PROVIDER: S-EPMC4040319 | biostudies-literature | 2014 Jun
REPOSITORIES: biostudies-literature
Laidlaw Tanya M TM Cutler Anya J AJ Kidder Molly S MS Liu Tao T Cardet Juan Carlos JC Chhay Heng H Feng Chunli C Boyce Joshua A JA
The Journal of allergy and clinical immunology 20140131 6
<h4>Background</h4>Aspirin-exacerbated respiratory disease (AERD) is an inflammatory condition of the respiratory tract and is characterized by overproduction of leukotrienes (LT) and large numbers of circulating granulocyte-platelet complexes. LT production can be suppressed by prostaglandin E(2) (PGE(2)) and the cyclic AMP-dependent protein kinase A (PKA).<h4>Objective</h4>To determine if PGE(2)-dependent control of LT production by granulocytes is dysregulated in AERD.<h4>Methods</h4>Granuloc ...[more]