Platelet tissue factor pathway inhibitor-α dampens cardiac thrombosis and associated fibrosis in mice. J Thromb Haemost 2023 Mar;21(3):639-651
Date
01/26/2023Pubmed ID
36696221Pubmed Central ID
PMC10200073DOI
10.1016/j.jtha.2022.11.034Scopus ID
2-s2.0-85149182853 (requires institutional sign-in at Scopus site) 2 CitationsAbstract
BACKGROUND: Tissue factor pathway inhibitor (TFPI) is the primary inhibitor of events initiating the blood coagulation pathway. Tfpi-/- mice die during embryonic development. The absence of protease-activated receptor (PAR) 4, the major thrombin receptor on mouse platelets, rescues Tfpi-/-mice to adulthood. Among the 3 TFPI isoforms in mice, TFPIα is the only isoform within platelets (pltTFPIα) and the only isoform that inhibits prothrombinase, the enzymatic complex that converts prothrombin to thrombin.
OBJECTIVES: To determine biological functions of pltTFPIα.
METHODS: Tfpi-/-/Par4-/- mice were irradiated and transplanted with bone marrow from mice lacking or containing pltTFPIα. Thus, PAR4 expression was restored in the recipient mice, which differed selectively by the presence or absence of pltTFPIα and lacked other forms of TFPI.
RESULTS: Recipient mice lacking pltTFPIα had reduced survival over the 200-day posttransplant period. Necropsy revealed radiation injury associated with large intraventricular platelet-rich thrombi, whereas other organs were not affected. Thrombi were associated with fibrotic presentations, including increased collagen deposition, periostin-positive activated fibroblasts, myofibroblasts, and macrophage infiltrates. Recipient mice containing pltTFPIα showed evidence of radiation injury but lacked heart pathology.
CONCLUSIONS: Tfpi-/-/Par4-/- mice develop severe cardiac fibrosis following irradiation and transplantation with bone marrow lacking pltTFPIα. This pathology is markedly reduced when the mice are transplanted with bone marrow containing pltTFPIα. Thus, in this model system pltTFPIα has an important physiological role in dampening pathological responses mediated by activated platelets within the heart tissue.
Author List
Maroney SA, Siebert AE, Martinez ND, Rasmussen M, Peterson JA, Weiler H, Lincoln J, Mast AEAuthors
Joy Lincoln PhD Professor in the Pediatrics department at Medical College of WisconsinHartmut Weiler PhD Associate Professor in the Physiology department at Medical College of Wisconsin
MESH terms used to index this publication - Major topics in bold
AnimalsBlood Platelets
Fibrosis
Mice
Protein Isoforms
Thrombin
Thrombosis
