Integrin α6β1 Is the Main Receptor for Vascular Laminins and Plays a Role in Platelet Adhesion, Activation, and Arterial Thrombosis

Here, the authors show that laminin-411, laminin-511, and laminin-521, but not laminin-211, allow efficient platelet adhesion and activation across a wide range of arterial wall shear rates. Adhesion was critically dependent on integrin α6β1. Platelets from integrin α6 knockout mice failed to adhere to laminin-411, laminin-511, and laminin-521 but responded normally to a series of agonists. α6β1-Deficient mice presented a marked decrease in arterial thrombosis in 3 models of injury of the carotid, aorta, and mesenteric arterioles. The authors thus reveal an unsuspected important contribution of laminins to thrombus formation in vivo.