OBJECTIVE: Arterial thrombi contain variable amounts of red blood cells (RBCs), which interact with fibrinogen through an eptifibatide-sensitive receptor and modify the structure of fibrin. In this study, we evaluated the modulator role of RBCs in the lytic susceptibility of fibrin. METHODS AND RESULTS: If fibrin is formed at increasing RBC counts, scanning electron microscopy evidenced a decrease in fiber diameter from 150 to 96 nm at 40% (v/v) RBCs, an effect susceptible to eptifibatide inhibition (restoring 140 nm diameter). RBCs prolonged the lysis time in a homogeneous-phase fibrinolytic assay with tissue plasminogen activator (tPA) by up to 22.7±1.6%, but not in the presence of eptifibatide. Confocal laser microscopy using green fluorescent protein-labeled tPA and orange fluorescent fibrin showed that 20% to 40% (v/v) RBCs significantly slowed down the dissolution of the clots. The fluorescent tPA variant did not accumulate on the surface of fibrin containing RBCs at any cell count above 10%. The presence of RBCs in the clot suppressed the tPA-induced plasminogen activation, resulting in 45% less plasmin generated after 30 minutes of activation at 40% (v/v) RBCs. CONCLUSIONS: RBCs confer lytic resistance to fibrin resulting from modified fibrin structure and impaired plasminogen activation through a mechanism that involves eptifibatide-sensitive fibrinogen-RBC interactions.
OBJECTIVE: Arterial thrombi contain variable amounts of red blood cells (RBCs), which interact with fibrinogen through an eptifibatide-sensitive receptor and modify the structure of fibrin. In this study, we evaluated the modulator role of RBCs in the lytic susceptibility of fibrin. METHODS AND RESULTS: If fibrin is formed at increasing RBC counts, scanning electron microscopy evidenced a decrease in fiber diameter from 150 to 96 nm at 40% (v/v) RBCs, an effect susceptible to eptifibatide inhibition (restoring 140 nm diameter). RBCs prolonged the lysis time in a homogeneous-phase fibrinolytic assay with tissue plasminogen activator (tPA) by up to 22.7±1.6%, but not in the presence of eptifibatide. Confocal laser microscopy using green fluorescent protein-labeled tPA and orange fluorescent fibrin showed that 20% to 40% (v/v) RBCs significantly slowed down the dissolution of the clots. The fluorescent tPA variant did not accumulate on the surface of fibrin containing RBCs at any cell count above 10%. The presence of RBCs in the clot suppressed the tPA-induced plasminogen activation, resulting in 45% less plasmin generated after 30 minutes of activation at 40% (v/v) RBCs. CONCLUSIONS: RBCs confer lytic resistance to fibrin resulting from modified fibrin structure and impaired plasminogen activation through a mechanism that involves eptifibatide-sensitive fibrinogen-RBC interactions.
Authors: Maria M Aleman; James R Byrnes; Jian-Guo Wang; Reginald Tran; Wilbur A Lam; Jorge Di Paola; Nigel Mackman; Jay L Degen; Matthew J Flick; Alisa S Wolberg Journal: J Clin Invest Date: 2014-07-01 Impact factor: 14.808
Authors: Adnan I Qureshi; Mushtaq H Qureshi; Iryna Lobanova; Asif Bashir; Asif A Khan; Stephen M Bologna; Michelle Peterson; M Fareed K Suri Journal: J Vasc Interv Neurol Date: 2016-01
Authors: Li Zhang; Rui Lan Zhang; Quan Jiang; Guangliang Ding; Michael Chopp; Zheng Gang Zhang Journal: Nat Protoc Date: 2015-03-05 Impact factor: 13.491