Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2001-12-28
pubmed:abstractText
Platelet adhesion and aggregation at sites of vascular injury are critically dependent on the interaction between von Willebrand factor (VWF) and 2 major platelet adhesion receptors, glycoprotein (GP) Ib/V/IX and integrin alpha(IIb)beta(3). GP Ib/V/IX binding to VWF mediates platelet tethering and translocation, whereas activation of integrin alpha(IIb)beta(3) promotes cell arrest. To date, the signaling pathways used by the VWF-GP Ib/V/IX interaction to promote activation of integrin alpha(IIb)beta(3), particularly under shear, have remained poorly defined. In this study, the potential involvement of type 1 phosphoinositide (PI) 3-kinases in this process was investigated. Results show that platelet adhesion and spreading on immobilized VWF results in a specific increase in the PI 3-kinase lipid product, PtdIns(3,4)P(2). Under static conditions, inhibiting PI 3-kinase with LY294002 or wortmannin did not prevent platelet adhesion, integrin alpha(IIb)beta(3) activation, or platelet spreading although it significantly delayed the onset of these events. In contrast, PI 3-kinase inhibition under shear dramatically reduced both platelet adhesion and spreading. Real-time analysis of intracellular calcium demonstrated that under static conditions inhibiting PI 3-kinase delayed the onset of intracellular fluxes in adherent platelets, but did not affect the final magnitude of the calcium response. However, under shear, inhibiting PI 3-kinase dramatically reduced intracellular calcium mobilization and integrin alpha(IIb)beta(3) activation, resulting in impaired thrombus growth. The studies demonstrate a shear-dependent role for PI 3-kinase in promoting platelet adhesion on immobilized VWF. Under static conditions, platelets appear to mobilize intracellular calcium through both PI 3-kinase-dependent and -independent mechanisms, whereas under shear PI 3-kinase is indispensable for VWF-induced calcium release.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/2-(4-morpholinyl)-8-phenyl-4H-1-benz..., http://linkedlifedata.com/resource/pubmed/chemical/Androstadienes, http://linkedlifedata.com/resource/pubmed/chemical/Calcium, http://linkedlifedata.com/resource/pubmed/chemical/Chromones, http://linkedlifedata.com/resource/pubmed/chemical/Enzyme Inhibitors, http://linkedlifedata.com/resource/pubmed/chemical/Morpholines, http://linkedlifedata.com/resource/pubmed/chemical/Phosphatidylinositol 3-Kinases, http://linkedlifedata.com/resource/pubmed/chemical/Phosphatidylinositol Phosphates, http://linkedlifedata.com/resource/pubmed/chemical/Platelet Glycoprotein GPIIb-IIIa..., http://linkedlifedata.com/resource/pubmed/chemical/Platelet Glycoprotein GPIb-IX..., http://linkedlifedata.com/resource/pubmed/chemical/phosphatidylinositol 3,4-diphosphate, http://linkedlifedata.com/resource/pubmed/chemical/von Willebrand Factor, http://linkedlifedata.com/resource/pubmed/chemical/wortmannin
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0006-4971
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
99
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
151-8
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed:year
2002
pubmed:articleTitle
Essential role for phosphoinositide 3-kinase in shear-dependent signaling between platelet glycoprotein Ib/V/IX and integrin alpha(IIb)beta(3).
pubmed:affiliation
Australian Centre for Blood Diseases, Department of Medicine, Monash Medical School, Box Hill Hospital, Victoria, Australia.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't