Cell-Free DNA Modulates Clot Structure and Impairs Fibrinolysis in XXXX .

@entity1 @entity32 @entity295 @entity1351
OBJECTIVES: @entity295 is characterized by systemic activation of @entity32 and coagulation in response to infection. In @entity295 , activated neutrophils extrude neutrophil extracellular traps composed of cell-free DNA (CFDNA) that not only trap pathogens but also provide a stimulus for clot formation. Although the effect of CFDNA on coagulation has been extensively studied, much less is known about the impact of CFDNA on fibrinolysis. To address this, we (1) investigated the relationship between CFDNA levels and fibrinolytic activity in @entity295 and (2) determined the mechanisms by which CFDNA modulates fibrinolysis. APPROACH AND RESULTS: Plasma was collected from healthy and septic individuals, and CFDNA was quantified. Clot lysis assays were performed in plasma and purified systems, and lysis times were determined by monitoring absorbance. Clot morphology was assessed using scanning electron microscopy. Clots formed in plasma from septic @entity1 containing >5   g/mL CFDNA were dense in structure and resistant to fibrinolysis, a phenomenon overcome by deoxyribonuclease addition. These effects were recapitulated in control plasma supplemented with CFDNA. In a purified system, CFDNA delayed fibrinolysis but did not alter tissue-type plasminogen activator-induced @entity1351 generation. Using surface plasmon resonance, CFDNA bound @entity1351 with a Kd value of 4.2  0.3   mol/L, and increasing concentrations of CFDNA impaired @entity1351 -mediated degradation of fibrin clots via the formation of a nonproductive ternary complex between @entity1351 , CFDNA, and fibrin. CONCLUSIONS: Our studies suggest that the increased levels of CFDNA in @entity295 impair fibrinolysis by inhibiting @entity1351 -mediated fibrin degradation, thereby identifying CFDNA as a potential therapeutic target for @entity295 treatment.
