因子 XIII 通过蛋白二硫键异构酶介导的活性改善血小板对纤维蛋白原的黏附。

Factor XIII improves platelet adhesion to fibrinogen by protein disulfide isomerase-mediated activity.

机构信息

Hemostasis Laboratory, Rabin Medical Center, Beilinson Hospital, Petach Tikva and Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.

出版信息

Thromb Res. 2013 Apr;131(4):338-41. doi: 10.1016/j.thromres.2012.12.003. Epub 2012 Dec 28.

DOI:10.1016/j.thromres.2012.12.003

PMID:23276530

Abstract

BACKGROUND

Factor XIII (FXIII), a plasma pro-transglutaminase, consists of two A subunits and two B subunits (FXIIIA2B2). Following activation by thrombin, it cross-links fibrin chains at the final step of coagulation. We previously reported that FXIII subunit A (FXIIIA) serves as a protein disulfide isomerase (PDI), and that PDI promotes platelet adhesion and aggregation.

OBJECTIVE

This study sought to examine possible mechanistic effect of FXIII on platelet adhesion to fibrinogen; specifically, the role of its PDI activity.

METHODS

Ex vivo experiments: Blood platelets derived from five patients with hereditary FXIIIA deficiency before and after treatment with Fibrogammin-P (FXIIIA2B2 concentrate) were washed and incubated on immobilized fibrinogen. Bound platelets were stained and counted by microscopy. In vitro experiments: Platelets derived from patients before treatment and five healthy controls were washed and analyzed for adhesion in the presence or absence of Fibrogammin-P or recombinant FXIII (FXIIIA2 concentrate).

RESULTS

In ex vivo experiments, one hour after Fibrogammin-P treatment, mean (±SEM) platelet adhesion to fibrinogen increased by 27±2.32% (p<0.001). In in vitro experiments, treatment with Fibrogammin-P or recombinant FXIII (10IU/mL each) enhanced platelet adhesion to fibrinogen (in patients, by 29.95±6.7% and 29.05±5.3%, respectively; in controls, by 26.06±3.24% and 26.91±4.72, respectively; p<0.04 for all). Iodoacetamide-treated FXIII (I-FXIII), where transglutaminase activity is blocked, showed similar enhanced adhesion as untreated FXIII. By contrast, addition of an antibody that specifically blocks FXIIIA-PDI activity inhibited FXIII-mediated platelet adhesion to fibrinogen by 65%.

CONCLUSION

These findings indicate that FXIII-induced enhancement of platelet adhesion is mediated by FXIII-PDI activity.

摘要

背景

因子 XIII（FXIII），一种血浆前转谷氨酰胺酶，由两个 A 亚基和两个 B 亚基（FXIIIA2B2）组成。在凝血的最后一步被凝血酶激活后，它交联纤维蛋白链。我们之前报道 FXIII 亚基 A（FXIIIA）作为一种蛋白二硫键异构酶（PDI），并且 PDI 促进血小板黏附和聚集。

目的

本研究旨在探讨 FXIII 对纤维蛋白原上血小板黏附的可能机制作用；具体来说，是其 PDI 活性的作用。

方法

体外实验：从五例遗传性 FXIIIA 缺乏症患者在接受 Fibrogammin-P（FXIIIA2B2 浓缩物）治疗前后获得血小板，并用固定化纤维蛋白原孵育。通过显微镜染色和计数来检测结合的血小板。在体实验：从患者和五名健康对照者在治疗前获得血小板，并用或不用 Fibrogammin-P 或重组 FXIII（FXIIIA2 浓缩物）分析黏附。

结果

在体外实验中，在 Fibrogammin-P 治疗后 1 小时，血小板对纤维蛋白原的黏附平均增加 27±2.32%（p<0.001）。在体实验中，用 Fibrogammin-P 或重组 FXIII（各 10IU/mL）处理增强了血小板对纤维蛋白原的黏附（在患者中，分别增加 29.95±6.7%和 29.05±5.3%；在对照组中，分别增加 26.06±3.24%和 26.91±4.72%；所有均 p<0.04）。碘乙酰胺处理的 FXIII（I-FXIII），其中转谷氨酰胺酶活性被阻断，显示出与未处理的 FXIII 相似的增强黏附。相比之下，特异性阻断 FXIIIA-PDI 活性的抗体抑制 FXIII 介导的纤维蛋白原上的血小板黏附 65%。