title: Platelet activation in cystic fibrosis.
abstract: Cystic fibrosis (CF) is caused by a mutation of the gene encoding the cystic fibrosis transmembrane conductance regulator (CFTR). We examined platelet function in CF patients because lung inflammation is part of this disease and platelets contribute to inflammation. CF patients had increased circulating leukocyte-platelet aggregates and increased platelet responsiveness to agonists compared with healthy controls. CF plasma caused activation of normal and CF platelets; however, activation was greater in CF platelets. Furthermore, washed CF platelets also showed increased reactivity to agonists. CF platelet hyperreactivity was incompletely inhibited by prostaglandin E(1) (PGE(1)). As demonstrated by Western blotting and reverse-transcriptase-polymerase chain reaction (RT-PCR), there was neither CFTR nor CFTR-specific mRNA in normal platelets. There were abnormalities in the fatty acid composition of membrane fractions of CF platelets. In summary, CF patients have an increase in circulating activated platelets and platelet reactivity, as determined by monocyte-platelet aggregation, neutrophil-platelet aggregation, and platelet surface P-selectin. This increased platelet activation in CF is the result of both a plasma factor(s) and an intrinsic platelet mechanism via cyclic adenosine monophosphate (cAMP)/adenylate cyclase, but not via platelet CFTR. Our findings may account, at least in part, for the beneficial effects of ibuprofen in CF.
authors.affiliation: Department of Pediatrics, UMass Memorial Health Care and University of Massachusetts Medical School, Worcester, MA 01655, USA. osullivb@ummhc.org <osullivb@ummhc.org>
authors.forename: Brian P
authors.initials: BP
authors.lastname: O'Sullivan
authors.forename: Matthew D
authors.initials: MD
authors.lastname: Linden
authors.forename: Andrew L
authors.initials: AL
authors.lastname: Frelinger
authors.forename: Marc R
authors.initials: MR
authors.lastname: Barnard
authors.forename: Michele
authors.initials: M
authors.lastname: Spencer-Manzon
authors.forename: James E
authors.initials: JE
authors.lastname: Morris
authors.forename: Raneem O
authors.initials: RO
authors.lastname: Salem
authors.forename: Michael
authors.initials: M
authors.lastname: Laposata
authors.forename: Alan D
authors.initials: AD
authors.lastname: Michelson
mesh_terms: D000262:Adenylyl Cyclases / Q000378:metabolism; D000293:Adolescent; D000328:Adult; D000527:Alprostadil / Q000037:antagonists & inhibitors; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology; D016718:Arachidonic Acid / Q000378:metabolism; D001792:Blood Platelets / Q000378:metabolism; D015153:Blotting, Western; D016022:Case-Control Studies; D002462:Cell Membrane / Q000378:metabolism; D002648:Child; D000242:Cyclic AMP / Q000378:metabolism; D003550:Cystic Fibrosis / Q000097:blood* / Q000188:drug therapy; D019005:Cystic Fibrosis Transmembrane Conductance Regulator / Q000096:biosynthesis; D005227:Fatty Acids / Q000378:metabolism; D005838:Genotype; D006801:Humans; D007052:Ibuprofen / Q000494:pharmacology; D007249:Inflammation; D007962:Leukocytes / Q000166:cytology; D009000:Monocytes / Q000166:cytology / Q000378:metabolism; D009504:Neutrophils / Q000378:metabolism; D019007:P-Selectin / Q000378:metabolism; D015539:Platelet Activation; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013928:Thromboxane A2 / Q000378:metabolism; D013997:Time Factors; D014810:Vitamin E / Q000378:metabolism
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; C505032:CFTR protein, human; D005227:Fatty Acids; D019007:P-Selectin; D012333:RNA, Messenger; D019005:Cystic Fibrosis Transmembrane Conductance Regulator; D014810:Vitamin E; D016718:Arachidonic Acid; D013928:Thromboxane A2; D000242:Cyclic AMP; D000262:Adenylyl Cyclases; D000527:Alprostadil; D007052:Ibuprofen