Linked Life Data

20539917

Source:http://linkedlifedata.com/resource/pubmed/id/20539917

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2010-8-4
pubmed:abstractText
The majority of the antiphospholipid antibodies, present in patients with antiphospholipid syndrome, are directed against conformational epitopes in beta2-glycoprotein I. beta2-glycoprotein I is an anionic phospholipid-binding 50-kDa plasma protein whose physiological role is not clear. Here we investigate the role of beta2-glycoprotein I in the phagocytosis of phosphatidylserine-expressing platelet microvesicles and the effect of autoantibodies to beta2-glycoprotein I on this process. We labelled the glycans of beta2-glycoprotein I with BODIPY (4,4-difluoro-4-bora-3a,4a-diaza-s-indacene)-hydrazide without affecting its phospholipid binding capacity. BODIPY-beta2-glycoprotein I bound to platelet microvesicles in a concentration-dependent manner and promoted the phagocytosis of platelet microvesicles by THP-1 derived macrophages in vitro at physiological plasma concentrations with a half maximal effect at approximately 10 microg/ml. beta2-glycoprotein I-stimulated phagocytosis was inhibited by annexin A5 and the phosphatidylserine-binding C1C2 fragment of lactadherin. Furthermore, immunoaffinity purified beta2-glycoprotein I-dependent antiphospholipid antibodies from five patients with antiphospholipid syndrome inhibited the phagocytosis in a concentration-dependent manner. These studies suggest that the binding of beta2-glycoprotein I to phosphatidylserine-expressing procoagulant platelet microvesicles may promote their clearance by phagocytosis and autoantibodies to beta2-glycoprotein I may inhibit this process to induce a procoagulant state.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0340-6245
pubmed:author
pubmed:issnType
Print
pubmed:volume
104
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
335-41
pubmed:dateRevised
2011-5-23
pubmed:meshHeading
pubmed:year
2010
pubmed:articleTitle
Phagocytosis of platelet microvesicles and beta2- glycoprotein I.
pubmed:affiliation
Department of Pathology and Medicine, Michael E DeBakey Veterans Affairs Medical Center, Baylor College of Medicine, Houston, Texas 77030, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Research Support, N.I.H., Extramural