蛋白二硫键异构酶小分子抑制剂PACMA-31对血小板活化、血栓形成以及止血的影响

Effect of Small-molecule Inhibitor of Protein Disulfide Isomerase-PACMA31 in Platelet Activation and Thrombosis

目的蛋白二硫键异构酶(protein disulfide isomerase,PDI)通过催化底物蛋白的二硫键调控其结构和功能。近期有研究发现小分子抑制剂PACMA-31(propynoic acid carbamoyl methyl amide-31)能够特异性地抑制PDI酶活性,本文我们将探讨PACMA-31对血小板活化和血栓形成的影响。方法通过还原酶活性测定实验验证PACMA-31抑制PDI酶活的特异性;通过血小板聚集实验、活体荧光显微镜实验和小鼠尾巴出血实验检测PACMA-31对血小板聚集,体内血栓形成和止血的影响。结果 PACMA-31能够显著地抑制重组PDI蛋白的还原酶活性,而不抑制重组ERp57蛋白的还原酶活性。PACMA-31抑制血小板聚集,同时对血小板的积聚以及纤维蛋白形成起抑制作用,并能够延长小鼠尾巴出血时间。结论 PDI的小分子抑制剂PACMA-31显著抑制血小板聚集,血栓形成和止血。

Objective Protein disulfide isomerase （PDI）could change the conformation and activity of its substrate by change the disulfide on it. Recent researches suggested that small-molecule inhibitor PACMA- 31 specially inhibit PDI. In this study,we explored the effect of PACMA-31 in platelet aggregation,thrombosis and hemostasis. Methods We used the reductase activity assay to study the specificity of PACMA-31 in in- hibiting the reductase activity of PDI. Platelet aggregation, intravital fluorescence microscopy and tail bleeding were performed to study the effect of PACMA-31 in platelet aggregation, thrombosis and hemostasis. Results PACMA-31 can significantly inhibit the reductase activity of recombinant PDI, but not ERp57. Platelet aggre- gation in vitro, platelet accumulation and fibrin deposition in vivo were obviously inhibited by PACMA-31, and tail bleeding time was also prolonged by PACMA-31. Conclusion PACMA-31 ,a small-molecule inhibitor of PDI, showed a remarkable restrictive effect on platelet aggregation, thrombosis and hemostasis.