Factor XIIIa-dependent retention of red blood cells in clots is mediated by fibrin α-chain crosslinking
Factor XIIIa-dependent retention of red blood cells in clots is mediated by fibrin α-chain crosslinking
复制标题
DOI：
10.1182/blood-2015-06-652263
复制
发表时间：
2015-10-15
期刊：
影响因子：
20.3
通讯作者：
Wolberg, Alisa S.
中科院分区：
文献类型：
--
作者：
Byrnes, James R.;Duval, Cedric;Wolberg, Alisa S.
因子XIII（a）[FXIII（a）]稳定凝块并增加对纤维蛋白溶解和机械破坏的抵抗力。FXIIIa还介导红细胞（RBC）在收缩凝块中的滞留，并决定静脉血栓大小，表明FXIII（a）是减少血栓形成的潜在靶点。然而，FXIIIa将RBC保留在凝块中的机制尚不清楚。我们测定了FXIII（a）对人和鼠凝块重量和组成的影响。实时显微镜检查显示，在没有FXIIIa活性的情况下形成的凝块中存在大量RBC损失，并且RBC在离开凝块时表现出短暂变形。纤维蛋白带位移测定和流式细胞术未显示纤维蛋白或FXIIIa底物与RBC的交联，表明FXIIIa不直接交联RBC与凝块。RBC保留在α 2-抗纤溶酶、凝血酶激活的纤溶抑制剂或纤连蛋白缺陷小鼠的凝块中，表明RBC保留不依赖于这些FXIIIa底物。血凝块中的RBC滞留与纤维蛋白网络密度呈正相关;然而，FXIIIa抑制降低了所有网络密度下的RBC滞留。FXIIIa抑制减少了由缺乏γ链交联位点的纤维蛋白原形成的凝块中的RBC滞留，但在缺乏α链交联位点的凝块中没有。此外，FXIIIa抑制剂的浓度，主要阻止α-，但不是γ-，链交联减少红细胞滞留在凝块。这些数据表明凝块中RBC的FXIIIa依赖性保留是由纤维蛋白α链交联介导的。这些发现揭示了一个新认识的，在整个血凝块形成和巩固纤维蛋白交联的重要作用，并建立FXIIIa活性作为血栓组成和大小的关键决定因素。
Factor XIII(a) [FXIII(a)] stabilizes clots and increases resistance to fibrinolysis and mechanical disruption. FXIIIa also mediates red blood cell (RBC) retention in contracting clots and determines venous thrombus size, suggesting FXIII(a) is a potential target for reducing thrombosis. However, the mechanism by which FXIIIa retains RBCs in clots is unknown. We determined the effect of FXIII(a) on human and murine clot weight and composition. Real-time microscopy revealed extensive RBC loss from clots formed in the absence of FXIIIa activity, and RBCs exhibited transient deformation as they exited the clots. Fibrin band-shift assays and flow cytometry did not reveal crosslinking of fibrin or FXIIIa substrates to RBCs, suggesting FXIIIa does not crosslink RBCs directly to the clot. RBCs were retained in clots from mice deficient in alpha(2)-antiplasmin, thrombin-activatable fibrinolysis inhibitor, or fibronectin, indicating RBC retention does not depend on these FXIIIa substrates. RBC retention in clots was positively correlated with fibrin network density; however, FXIIIa inhibition reduced RBC retention at all network densities. FXIIIa inhibition reduced RBC retention in clots formed with fibrinogen that lacks gamma-chain crosslinking sites, but not in clots that lack alpha-chain crosslinking sites. Moreover, FXIIIa inhibitor concentrations that primarily block alpha-, but not gamma-, chain crosslinking decreased RBC retention in clots. These data indicate FXIIIa-dependent retention of RBCs in clots is mediated by fibrin alpha-chain crosslinking. These findings expose a newly recognized, essential role for fibrin crosslinking during whole blood clot formation and consolidation and establish FXIIIa activity as a key determinant of thrombus composition and size.