Two types of procoagulant platelets are formed upon physiological activation and are controlled by integrin α(IIb)ß(3).
Arterioscler Thromb Vasc Biol
; 32(10): 2475-83, 2012 Oct.
Article
em En
| MEDLINE
| ID: mdl-22837472
ABSTRACT
OBJECTIVE:
Phosphatidylserine (PS) externalization by platelets upon activation is a key event in hemostasis and thrombosis. It is currently believed that strong stimulation of platelets forms 2 subpopulations, only 1 of which expresses PS. METHODS ANDRESULTS:
Here, we demonstrate that physiological stimulation leads to the formation of not 1 but 2 types of PS-expressing activated platelets, with dramatically different properties. One subpopulation sustained increased calcium level after activation, whereas another returned to the basal low-calcium state. High-calcium PS-positive platelets had smaller size, high surface density of fibrin(ogen), no active integrin α(IIb)ß(3), depolarized mitochondrial membranes, gradually lost cytoplasmic membrane integrity, and were poorly aggregated. In contrast, the low-calcium PS-positive platelets had normal size, retained mitochondrial membrane potential and cytoplasmic membrane integrity, and combined retention of fibrin(ogen) with active α(IIb)ß(3) and high proaggregatory function. Formation of low-calcium PS-positive platelets was promoted by platelet concentration increase or shaking and was decreased by integrin α(IIb)ß(3) antagonists, platelet dilution, or in platelets from kindlin-3-deficient and Glanzmann thrombasthenia patients.CONCLUSIONS:
Identification of a novel PS-expressing platelet subpopulation with low calcium regulated by integrin α(IIb)ß(3) can be important for understanding the mechanisms of PS exposure and thrombus formation.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Coagulação Sanguínea
/
Plaquetas
/
Trombastenia
/
Complexo Glicoproteico GPIIb-IIIa de Plaquetas
Tipo de estudo:
Prognostic_studies
Limite:
Humans
Idioma:
En
Ano de publicação:
2012
Tipo de documento:
Article