This project tests the hypotheses that deficient EP2 receptor expression and function in platelets and leukocytes alters homeostasis of the adenylyl cyclase/cyclic adenosine monophosphate (cAMP) pathway as a disease-causing mechanism in aspirin exacerbated respiratory disease (AERD). Platelets are required for granulocyte recruitment in animal models of pulmonary inflammation, binding to leukocytes via P-selectin (CD62P) and facilitating integrin avidity. When bound to neutrophils, platelets can also form leukotriene (LT)C4 (the parent of the cysteinly leukotrienes (cys-LTs)) from neutrophil-derived LTA4. We have discovered that platelets from subjects with aspirin exacerbated respiratory disease (AERD) are markedly deficient in expression of the Gs-linked EP2 receptor for PGE2 relative to platelets from normal and aspirin-tolerant asthmatic (ATA) controls. As a result, neither exogenous PGE2 nor a selective EP2 agonist can block activation of platelets from individuals with AERD in vitro, or the formation of platelet-leukocyte aggregates. Moreover, peripheral blood samples from individuals with AERD contain several fold higher frequencies of platelet-leukocyte aggregates than do samples from normal and aspirin-tolerant ATA controls, suggesting a functional result of diminished EP2 signaling in vivo that could enhance both tissue inflammation and the generation of cys-LTs. Furthermore, the defect in EP2 receptor expression extends to peripheral blood leukocytes from individuals with AERD, accompanied by concomitantly defective expression of mRNA encoding EP4 receptors;both defects are reversed by aspirin treatment.
Aim 1 is to determine the consequences of defects in the function of the EP2 subtype of prostaglandin E2 receptor on platelets in the pathophysiology of AERD.
Aim 2 is to determine the consequences of deficient of EP2 and EP4 receptor signaling on 5-lipoxygenase (5-LO) pathway activity in peripheral blood leukocytes and whether the deficiency is corrected by treatment with aspirin.
Aim 3 is to characterize the extent of epigenetic variation in EP receptors, classical and novel CysLTRs, and associated candidate effectors in AERD.

Public Health Relevance

Aspirin exacerbated respiratory disease (AERD) is a severe form of asthma. This project seeks to determine the reason why individuals with AERD lack a protein called EP2, and to determine whether the lack of EP2 is a causitive feature of the disease. The studies will point the way toward expaining why people develop AERD, and what can be done to treat or prevent it.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Program--Cooperative Agreements (U19)
Project #
5U19AI095219-02
Application #
8377210
Study Section
Special Emphasis Panel (ZAI1-PA-I)
Project Start
Project End
Budget Start
2012-07-01
Budget End
2013-06-30
Support Year
2
Fiscal Year
2012
Total Cost
$708,240
Indirect Cost
$311,467
Name
Brigham and Women's Hospital
Department
Type
DUNS #
030811269
City
Boston
State
MA
Country
United States
Zip Code
02115
Cahill, Katherine N; Raby, Benjamin A; Zhou, Xiaobo et al. (2016) Impaired E Prostanoid2 Expression and Resistance to Prostaglandin E2 in Nasal Polyp Fibroblasts from Subjects with Aspirin-Exacerbated Respiratory Disease. Am J Respir Cell Mol Biol 54:34-40
Bankova, Lora G; Lai, Juying; Yoshimoto, Eri et al. (2016) Leukotriene E4 elicits respiratory epithelial cell mucin release through the G-protein-coupled receptor, GPR99. Proc Natl Acad Sci U S A 113:6242-7
Lee, Min Jung; Yoshimoto, Eri; Saijo, Shinobu et al. (2016) Phosphoinositide 3-Kinase δ Regulates Dectin-2 Signaling and the Generation of Th2 and Th17 Immunity. J Immunol 197:278-87
Buchheit, Kathleen M; Cahill, Katherine N; Katz, Howard R et al. (2016) Thymic stromal lymphopoietin controls prostaglandin D2 generation in patients with aspirin-exacerbated respiratory disease. J Allergy Clin Immunol 137:1566-1576.e5
Dwyer, Daniel F; Barrett, Nora A; Austen, K Frank et al. (2016) Expression profiling of constitutive mast cells reveals a unique identity within the immune system. Nat Immunol 17:878-87
Liu, Tao; Kanaoka, Yoshihide; Barrett, Nora A et al. (2015) Aspirin-Exacerbated Respiratory Disease Involves a Cysteinyl Leukotriene-Driven IL-33-Mediated Mast Cell Activation Pathway. J Immunol 195:3537-45
Cardet, Juan Carlos; Israel, Elliot (2015) Update on reslizumab for eosinophilic asthma. Expert Opin Biol Ther 15:1531-9
Liu, Tao; Garofalo, Denise; Feng, Chunli et al. (2015) Platelet-driven leukotriene C4-mediated airway inflammation in mice is aspirin-sensitive and depends on T prostanoid receptors. J Immunol 194:5061-8
Cahill, Katherine N; Bensko, Jillian C; Boyce, Joshua A et al. (2015) Prostaglandin Dâ‚‚: a dominant mediator of aspirin-exacerbated respiratory disease. J Allergy Clin Immunol 135:245-52
Lee-Sarwar, Kathleen; Johns, Christina; Laidlaw, Tanya M et al. (2015) Tolerance of daily low-dose aspirin does not preclude aspirin-exacerbated respiratory disease. J Allergy Clin Immunol Pract 3:449-51

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