fig2

Figure 2. Platelet adhesion, activation and platelet-derived microparticles. Platelets initially tether to exposed vWF via the GPIb-IX-V receptor under high shear stress, then undergo activation marked by GPIIb/IIIa (integrin αIIbβ3) conformational change detected by PAC-1 (a monoclonal antibody that specifically recognizes the active conformation of integrin αIIbβ3), CD62P and CD40L expression, with fibrinogen crosslinking adjacent platelets to consolidate aggregates. Activated platelets additionally shed procoagulant (phosphatidylserine-exposing) and proinflammatory (CD40L-bearing) microparticles (PMPs), which further amplify both thrombosis and inflammation. vWF: von Willebrand factor; GPIb-IX-V: glycoprotein Ib-IX-V complex; GPIIb/IIIa: glycoprotein IIb/IIIa (integrin αIIbβ3); CD62P: P-selectin; CD40L: CD40 ligand; PMPs: platelet-derived microparticles; PS: phosphatidylserine.