Cytosolic and mitochondrial Ca signaling in procoagulant platelets.

SummaryPlatelets are the major cellular contributor to arterial thrombosis. However, activated platelets form two distinct subpopulations during thrombosis. Pro-aggregatory platelets aggregate to form the main body of the thrombus. In contrast, procoagulant platelets expose phosphatidylserine on their outer surface and promote thrombin generation. This apparently all-or-nothing segregation into subpopulations indicates that, during activation, platelets commit to becoming procoagulant or pro-aggregatory. Although the signaling pathways that control this commitment are not understood, distinct cytosolic and mitochondrial Ca signals in different subpopulations are likely to be central. In this review, we discuss how these Ca signals control procoagulant platelet formation and whether this process can be targeted pharmacologically to prevent arterial thrombosis.