European Perspectives

U949, EFS-Alsace, France, investigates the interaction of blood platelets with extracellular matrix proteins in the vessel wall.His latest article in Circulation titled "Integrin α6β1 Is the Main Receptor for Vascular Laminins and Plays a Role in Platelet Adhesion, Activation, and Arterial Thrombosis," reveals an unsuspected important contribution of laminins to thrombus formation in vivo and suggests that targeting their main receptor, integrin α6β1, could represent an alternative antithrombotic strategy with a potentially low bleeding risk. 1 Although integrin α6β1 is a known platelet receptor for laminins, its importance in haemostasis and arterial thrombosis remained unclear."We developed a mouse that does not express integrin α6β1 on platelets," Dr Mangin explains."We showed that this receptor appears to play a minor role in haemostasis but is involved in thrombus formation after superficial vascular injury.Its importance in arterial thrombosis remains to be established, but this receptor could play a role because atherosclerotic plaques contain high levels of reactive laminins."Dr Mangin comments that the risk of bleeding associated with current antiplatelet drugs because they target the haemostatic functions of platelets is a major drawback and that a key question is: Would it be possible to target thrombosis without impairing haemostasis?He says, "The main difference between haemostasis and thrombosis is that thrombosis occurs in a diseased vessel with a thickened wall due to atherosclerotic plaque formation.We believe targeting platelet-reactive proteins that are strongly expressed in an atherosclerotic plaque but are absent from the healthy vessel wall would represent a safe antithrombotic strategy.Two years ago we identified tenascin-C as an atherosclerotic plaque protein that supports efficient platelet adhesion and activation.We are now trying to evaluate the importance of this protein in arterial thrombosis to provide the proof of concept."This research resulted in a particularly enjoyable