Identification of Coagulation Factor XI as a Ligand for Platelet Apolipoprotein E Receptor 2 (ApoER2)

• DOI: 10.1161/atvbaha.109.187393
• Publication Date: 2009-08-07T01:56:53Z
• Authors: Tara C. White-Adams; Michelle A. Berny; Erik I. Tucker; Jacqueline M. Gertz; David Gailani; Rolf T. Urbanus; Philip G. de Groot; András Gruber; Owen J.T. McCarty
• Keywords: Blood Platelets; Mice, Inbred C57BL; Mice; Zinc; Kininogen, High-Molecular-Weight; Platelet Adhesiveness; Animals; Humans; Calcium; Ligands; Factor XI; LDL-Receptor Related Proteins; Receptors, Lipoprotein

Factor XI (FXI) promotes hemostasis and thrombosis through enhancement of thrombin generation has been shown to play a critical role in the formation occlusive thrombi arterial injury models. The aim this study was investigate mechanisms governing interactions between FXI platelets.Platelet adhesion immobilized abrogated presence low-density lipoprotein (LDL) receptor antagonist, receptor-associated protein (RAP), soluble recombinant apolipoprotein E 2 (ApoER2), or LDL-binding domain 1 ApoER2. supported wild-type murine platelet binding; contrast, ApoER2-deficient platelets did not adhere FXI. In shear, aggregates formed on activated (FXIa) surfaces, whereas RAP, binding ApoER2, an anti-GPIb alpha mAb blocked FXIa under shear. Soluble bound ApoER2' with affinity 61 nmol/L.This identified (ApoER2, LRP8), member LDL family, as for interaction other cell types that express ApoER2 remains be explored.