Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
42
pubmed:dateCreated
2005-10-17
pubmed:abstractText
We investigated the assembly of soluble fibronectin by lysophosphatidic acid-activated platelets adherent to fibrinogen or fibrin. More fibronectin was assembled by activated platelets spread on fibrin matrices than by platelets spread on adsorbed fibrinogen. The difference between platelets adherent to fibrinogen and fibrin occurred under both static and flow conditions. Similar differences were seen in binding of the 70-kDa N-terminal fragment of fibronectin that recognizes fibronectin assembly sites on adherent cells. Antibody and peptide blocking studies demonstrated that alphaIIb beta3 integrin mediates platelet adhesion to fibrinogen, whereas both alphav beta3 and alphaIIb beta3 mediate platelet adhesion to fibrin. The hypothesis that engagement of the C-terminal QAGDV sequence of the fibrinogen gamma-chain by alphaIIb beta3 inhibits the ability of the platelet to assemble fibronectin was tested by several experiments. Activated platelets adherent to adsorbed mutant fibrinogen lacking the QAGDV sequence (gammadelta5FG) were assembly-competent, as were platelets adherent to adsorbed normal fibrinogen that had been pretreated with the 7E9 antibody to the C terminus of the gamma-chain. Moreover, adsorbed normal fibrinogen but not gammadelta5FG suppressed the ability of co-adsorbed fibronectin to direct assembly of soluble fibronectin by spread platelets. The suppressive effect was lost when a surface of co-adsorbed fibronectin and fibrinogen was pretreated with 7E9. These results support a model in which the engagement of alphaIIb beta3 by the C-terminal sequence of the fibrinogen gamma-chain initiates signals that suppress subsequent fibronectin assembly by spread platelets. This interaction is less dominant when platelets adhere to fibrin, resulting in enhanced fibronectin assembly.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
21
pubmed:volume
280
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
35490-8
pubmed:meshHeading
pubmed-meshheading:16051597-Adsorption, pubmed-meshheading:16051597-Animals, pubmed-meshheading:16051597-Blood Platelets, pubmed-meshheading:16051597-Cell Adhesion, pubmed-meshheading:16051597-Cell Proliferation, pubmed-meshheading:16051597-Cross-Linking Reagents, pubmed-meshheading:16051597-Electrophoresis, Polyacrylamide Gel, pubmed-meshheading:16051597-Enzyme-Linked Immunosorbent Assay, pubmed-meshheading:16051597-Epitopes, pubmed-meshheading:16051597-Fibrin, pubmed-meshheading:16051597-Fibrinogen, pubmed-meshheading:16051597-Fibronectins, pubmed-meshheading:16051597-Humans, pubmed-meshheading:16051597-Mice, pubmed-meshheading:16051597-Platelet Adhesiveness, pubmed-meshheading:16051597-Platelet Aggregation, pubmed-meshheading:16051597-Platelet Glycoprotein GPIIb-IIIa Complex, pubmed-meshheading:16051597-Protein Structure, Tertiary, pubmed-meshheading:16051597-Vitronectin
pubmed:year
2005
pubmed:articleTitle
Fibrin but not adsorbed fibrinogen supports fibronectin assembly by spread platelets. Effects of the interaction of alphaIIb beta3 with the C terminus of the fibrinogen gamma-chain.
pubmed:affiliation
Molecular and Cellular Pharmacology Program and Department of Medicine, University of Wisconsin-Madison School of Medicine, Madison, Wisconsin 53706, USA.
pubmed:publicationType
Journal Article