New insights into the biology of tissue factor pathway inhibitor. (June 2015)

• Record Type: Journal Article
• Authors: Maroney, S. A.; Mast, A. E.
• Is Part Of: Journal of thrombosis and haemostasis. Volume 13:(2015:Jan.)Supplement 1
• Page Start: S200
• Page End: S207
• Publication Date: 2015-06
• Subjects: hemophilia -- prothrombinase -- TFPI -- thrombosis -- tissue factor; Thrombosis -- Periodicals; Hemostasis -- Periodicals; Blood coagulation disorders -- Periodicals; 616.1
• DOI: 10.1111/jth.12897
• Languages: English
• ISSNs: 1538-7933

Abstract

Summary: Tissue factor pathway inhibitor (TFPI) dampens the initiation of blood coagulation by inhibiting two potent procoagulant complexes, tissue factor‐factor VIIa (TF–FVIIa) and early forms of prothrombinase. TFPI isoforms, TFPIα and TFPIβ, result from alternative splicing of mRNA, producing distinct C‐terminal ends of the two proteins. Both isoforms inhibit TF–FVIIa, but only TFPIα can inhibit early forms of prothrombinase by binding of its positively charged C‐terminus with high affinity to the acidic B‐domain exosite of FVa, which is generated upon activation by FXa. TFPIα and TFPIβ are produced in cultured human endothelial cells, while platelets contain only TFPIα. Knowledge of the anticoagulant mechanisms and tissue expression patterns of TFPIα and TFPIβ have improved our understanding of the phenotypes observed in different mouse models of TFPI deficiency, the east Texas bleeding disorder, and the development of pharmaceutical agents that block TFPI function to treat hemophilia.