TY - JOUR
T1 - Autocrine amplification of integrin αIIbβ3 activation and platelet adhesive responses by deoxyribose-1-phosphate
AU - Vara, Dina S.
AU - Campanella, Michelangelo
AU - Canobbio, Ilaria
AU - Dunn, Warwick B.
AU - Pizzorno, Giuseppe
AU - Hirano, Michio
AU - Pula, Giordano
PY - 2013/4/14
Y1 - 2013/4/14
N2 - Using direct injection mass spectrometry (DIMS) we discovered that deoxyribose-1-phosphate (dRP) is released by platelets upon activation. Interestingly, the addition of exogenous dRP to human platelets significantly increased platelet aggregation and integrin αIIbβ3 activation in response to thrombin. In parallel, genetically modified platelets with double genetic deletion of thymidine phosphorylase and uridine phosphorylase were characterised by reduced release of dRP, impaired aggregation and decreased integrin αIIbβ3 activation in response to thrombin. In vitro platelet adhesion onto fibrinogen and collagen under physiological flow conditions was potentiated by treatment of human platelets with exogenous dRP and impaired in transgenic platelets with reduced dRP release. Human and mouse platelets responded to dRP treatment with a sizeable increase in reactive oxygen species (ROS) generation and the pre-treament with the antioxidant apocynin abolished the effect of dRP on aggregation and integrin activation. Experiments directly assessing the activation of the small G protein Rap1b and protein kinase C suggested that dRP increases the basal levels of activity of these two pivotal platelet-activating pathways in a redox-dependent manner. Taken together, we present evidence that dRP is a novel autocrine amplifier of platelet activity, which acts on platelet redox levels and modulates integrin αIIbβ3.
AB - Using direct injection mass spectrometry (DIMS) we discovered that deoxyribose-1-phosphate (dRP) is released by platelets upon activation. Interestingly, the addition of exogenous dRP to human platelets significantly increased platelet aggregation and integrin αIIbβ3 activation in response to thrombin. In parallel, genetically modified platelets with double genetic deletion of thymidine phosphorylase and uridine phosphorylase were characterised by reduced release of dRP, impaired aggregation and decreased integrin αIIbβ3 activation in response to thrombin. In vitro platelet adhesion onto fibrinogen and collagen under physiological flow conditions was potentiated by treatment of human platelets with exogenous dRP and impaired in transgenic platelets with reduced dRP release. Human and mouse platelets responded to dRP treatment with a sizeable increase in reactive oxygen species (ROS) generation and the pre-treament with the antioxidant apocynin abolished the effect of dRP on aggregation and integrin activation. Experiments directly assessing the activation of the small G protein Rap1b and protein kinase C suggested that dRP increases the basal levels of activity of these two pivotal platelet-activating pathways in a redox-dependent manner. Taken together, we present evidence that dRP is a novel autocrine amplifier of platelet activity, which acts on platelet redox levels and modulates integrin αIIbβ3.
KW - Deoxyribose-1-phosphate
KW - Integrin
KW - Platelets
KW - Reactive oxygen species
KW - Redox signalling
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U2 - 10.1160/TH12-10-0751
DO - 10.1160/TH12-10-0751
M3 - Article
C2 - 23494007
AN - SCOPUS:84878627332
VL - 109
SP - 1108
EP - 1119
JO - Thrombosis and Haemostasis
JF - Thrombosis and Haemostasis
SN - 0340-6245
IS - 6
ER -