Neutrophil extracellular traps promote deep vein thrombosis in mice

TY - JOUR

T1 - Neutrophil extracellular traps promote deep vein thrombosis in mice

AU - Brill, A

AU - Fuchs, T A

AU - Savchenko, A S

AU - Thomas, G M

AU - Martinod, K

AU - De Meyer, S F

AU - Bhandari, A A

AU - Wagner, Denisa D

PY - 2012/1/1

Y1 - 2012/1/1

N2 - BACKGROUND: Upon activation, neutrophils can release nuclear material known as neutrophil extracellular traps (NETs), which were initially described as a part of antimicrobial defense. Extracellular chromatin was recently reported to be prothrombotic in vitro and to accumulate in plasma and thrombi of baboons with experimental deep vein thrombosis (DVT).OBJECTIVE: To explore the source and role of extracellular chromatin in DVT.METHODS: We used an established murine model of DVT induced by flow restriction (stenosis) in the inferior vena cava (IVC).RESULTS: We demonstrate that the levels of extracellular DNA increase in plasma after 6 h IVC stenosis, compared with sham-operated mice. Immunohistochemical staining revealed the presence of Gr-1-positive neutrophils in both red (RBC-rich) and white (platelet-rich) parts of thrombi. Citrullinated histone H3 (CitH3), an element of NETs' structure, was present only in the red part of thrombi and was frequently associated with the Gr-1 antigen. Immunofluorescent staining of thrombi showed proximity of extracellular CitH3 and von Willebrand factor (VWF), a platelet adhesion molecule crucial for thrombus development in this model. Infusion of Deoxyribonuclease 1 (DNase 1) protected mice from DVT after 6 h and also 48 h IVC stenosis. Infusion of an unfractionated mixture of calf thymus histones increased plasma VWF and promoted DVT early after stenosis application.CONCLUSIONS: Extracellular chromatin, likely originating from neutrophils, is a structural part of a venous thrombus and both the DNA scaffold and histones appear to contribute to the pathogenesis of DVT in mice. NETs may provide new targets for DVT drug development.

AB - BACKGROUND: Upon activation, neutrophils can release nuclear material known as neutrophil extracellular traps (NETs), which were initially described as a part of antimicrobial defense. Extracellular chromatin was recently reported to be prothrombotic in vitro and to accumulate in plasma and thrombi of baboons with experimental deep vein thrombosis (DVT).OBJECTIVE: To explore the source and role of extracellular chromatin in DVT.METHODS: We used an established murine model of DVT induced by flow restriction (stenosis) in the inferior vena cava (IVC).RESULTS: We demonstrate that the levels of extracellular DNA increase in plasma after 6 h IVC stenosis, compared with sham-operated mice. Immunohistochemical staining revealed the presence of Gr-1-positive neutrophils in both red (RBC-rich) and white (platelet-rich) parts of thrombi. Citrullinated histone H3 (CitH3), an element of NETs' structure, was present only in the red part of thrombi and was frequently associated with the Gr-1 antigen. Immunofluorescent staining of thrombi showed proximity of extracellular CitH3 and von Willebrand factor (VWF), a platelet adhesion molecule crucial for thrombus development in this model. Infusion of Deoxyribonuclease 1 (DNase 1) protected mice from DVT after 6 h and also 48 h IVC stenosis. Infusion of an unfractionated mixture of calf thymus histones increased plasma VWF and promoted DVT early after stenosis application.CONCLUSIONS: Extracellular chromatin, likely originating from neutrophils, is a structural part of a venous thrombus and both the DNA scaffold and histones appear to contribute to the pathogenesis of DVT in mice. NETs may provide new targets for DVT drug development.

KW - Animals

KW - Chromatin

KW - DNA

KW - Histones

KW - Mice

KW - Neutrophils

KW - Vena Cava, Inferior

KW - Venous Thrombosis

KW - von Willebrand Factor

U2 - 10.1111/j.1538-7836.2011.04544.x

DO - 10.1111/j.1538-7836.2011.04544.x

M3 - SCORING: Journal article

C2 - 22044575

VL - 10

SP - 136

EP - 144

JO - J THROMB HAEMOST

JF - J THROMB HAEMOST

SN - 1538-7933

IS - 1

ER -