Prevention of acute thrombosis after vascular intervention-gene transfer of WVF-CP

背景：富血小板血栓形成是心血管疾病发病的关键事件。由于血管性血友病因子（vonWillebrand factor，VWF）在血小板粘附和聚集中起重要作用，因此其代谢在血小板活化和募集的调节中是重要的。VWF作为多聚体从内皮细胞分泌，其自发地结合GP Ib-IX复合物并聚集血小板。VWF裂解蛋白酶（VWF-CP）通过裂解VWF的多聚体来防止正常循环中的血小板聚集。本研究探讨是否VWF-CP抑制血小板聚集和血栓形成后，腺病毒介导的基因转移到血管平滑肌细胞（SMCs）。方法和结果;我们构建了腺病毒载体表达人VWF-CP（AdVWFCP）和细菌β-半乳糖苷酶（AdLacZ）。血管平滑肌细胞感染AdVWFCP后表达明显的VWF-CP活性。相反，用AdLacZ感染的SMC没有。为了研究体内VWF-CP的抗血栓形成和抗增殖作用，我们在基因转移后5天通过全身给予虎红和经腔绿色光在大鼠颈动脉中产生血栓形成，并在血栓形成后3周检查新生内膜生长。AdLacZ感染的动脉中的血流迅速恶化，并在闭塞性血栓形成的2分钟内消失。与此相反，在AdVWFCP感染的动脉中的血流在照射期间被保存至少5分钟。此外，血栓形成和随后的新生内膜生长适度inhibited.Conclusion ;局部表达的VWF-CP损伤动脉可能会阻止动脉血栓形成和随后的新生内膜生长。

Background ; Platelet-rich thrombus formation is a critical event in the onset of cardiovascular disease. Since von Willebrand factor(VWF)plays a significant role in platelet adhesion and aggregation, its metabolism is important in the regulation of platelet activation and recruitment. VWF is secreted from endothelial cells as a multimers that spontaneously bind the GP Ib-IX complex and aggregate platelets. VWF-cleaving protease (VWF-CP)is essential for preventing platelet aggregation in the normal circulation, by cleaving the multimers of VWF. The present study examines whether VWF-CP suppress platelet aggregation and thrombus formation after adenovirus-mediated gene transfer to vascular smooth muscle cells(SMCs).Methods and Results ; We constructed adenovirus vectors expressing human VWF-CP (AdVWFCP) and bacterial beta-galactosidase (AdLacZ). Vascular SMCs infected with AdVWFCP expressed significant VWF-CP activity. In contrast, SMCs infected with AdLacZ did not. To investigate the antithrombotic and antiproliferative effects of VWF-CP in vivo, we generated thrombosis in rat carotid arteries by systemically administered rose bengal and transluminal green light 5 days after gene transfer, and examined neointimal growth 3 weeks after thrombus formation. Blood flow in AdLacZ-infected arteries rapidly deteriorated and vanished within 2 min of occlusive thrombus formation. In contrast, blood flow in AdVWFCP-infected arteries was preserved for at least 5 min during irradiation. In addition, thrombus formation and subsequent neointimal growth were moderately suppressed.Conclusion ; The local expression of VWF-CP in injured arteries might prevent arterial thrombosis and subsequent neointimal growth.