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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
11
pubmed:dateCreated
2010-5-20
pubmed:abstractText
Platelet-activating factor (PAF [1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine]) is a phospholipid mediator released from activated macrophages, mast cells, and basophils that promotes pathophysiologic inflammation. Eosinophil responses to PAF are complex and incompletely elucidated. We show in this article that PAF and its 2-deacetylated metabolite (lysoPAF) promote degranulation (release of eosinophil peroxidase) via a mechanism that is independent of the characterized PAFR. Specifically, we demonstrate that receptor antagonists CV-3988 and WEB-2086 and pertussis toxin have no impact on PAF- or lysoPAF-mediated degranulation. Furthermore, cultured mouse eosinophils from PAFR(-/-) bone marrow progenitors degranulate in response to PAF and lysoPAF in a manner indistinguishable from their wild-type counterparts. In addition to PAF and lysoPAF, human eosinophils degranulate in response to lysophosphatidylcholine, but not phosphatidylcholine, lysophosphatidylethanolamine, or phosphatidylethanolamine, demonstrating selective responses to phospholipids with a choline head-group and minimal substitution at the sn-2 hydroxyl. Human eosinophils release preformed cytokines in response to PAF, but not lysoPAF, also via a PAFR-independent mechanism. Mouse eosinophils do not release cytokines in response to PAF or lysoPAF, but they are capable of doing so in response to IL-6. Overall, our work provides the first direct evidence for a role for PAF in activating and inducing degranulation of mouse eosinophils, a crucial feature for the interpretation of mouse models of PAF-mediated asthma and anaphylaxis. Likewise, we document and define PAF and lysoPAF-mediated activities that are not dependent on signaling via PAFR, suggesting the existence of other unexplored molecular signaling pathways mediating responses from PAF, lysoPAF, and closely related phospholipid mediators.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
1550-6606
pubmed:author
pubmed:issnType
Electronic
pubmed:day
1
pubmed:volume
184
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
6327-34
pubmed:meshHeading
pubmed:year
2010
pubmed:articleTitle
Mouse and human eosinophils degranulate in response to platelet-activating factor (PAF) and lysoPAF via a PAF-receptor-independent mechanism: evidence for a novel receptor.
pubmed:affiliation
Section of Eosinophil Biology, Laboratory of Allergic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892-1883, USA. kdyer@niaid.nih.gov
pubmed:publicationType
Journal Article, Research Support, N.I.H., Extramural, Research Support, N.I.H., Intramural