Abstract
Platelets are critical mediators of thrombosis and hemostasis. In response to agonist,
platelets aggregate to form a thrombus via ligand binding of the glycoprotein IIb/IIIa
receptor. However, activated platelets are heterogeneous in nature and a subset of
platelets stimulated by strong agonists support the assembly of the coagulation complexes.
It is proposed that these “procoagulant” platelets have a unique role in hemostasis
and thrombosis as the link between primary and secondary hemostasis, localizing the
thrombin burst required for fibrin formation to micro-domains within the platelet
thrombus. Loss of procoagulant potential leads to bleeding while an increase is linked
with propensity to thrombosis. While many features of the procoagulant platelet are
known, the exact nature of the procoagulant platelet remains controversial. It is
noted that many of the morphological and biochemical features of procoagulant platelets
are also features of the cyclophilin D necrosis pathway. This review will focus on
the distinct roles of platelet subpopulations, the identity of the procoagulant platelet,
and the potential role of the cell death pathways in regulating platelet procoagulant
response.
Keywords
procoagulant - platelet - necrosis - apoptosis