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

背景;血小板丰富的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（VWF）在血小板粘附和聚集中起着重要作用，其代谢在血小板活化和募集的调控中起着重要作用。VWF作为多聚体从内皮细胞分泌，可自发结合GP Ib-IX复合物并聚集血小板。VWF-切割蛋白酶（VWF- cp）通过切割VWF的多聚体来防止血小板在正常循环中聚集。本研究探讨了VWF-CP在腺病毒介导的基因转移到血管平滑肌细胞（SMCs）后是否抑制血小板聚集和血栓形成。方法与结果；构建了表达人VWF-CP （AdVWFCP）和细菌β -半乳糖苷酶（AdLacZ）的腺病毒载体。AdVWFCP感染的血管SMCs表达了显著的VWF-CP活性。相比之下，感染了AdLacZ的SMCs则没有。为了研究VWF-CP在体内的抗血栓和抗增殖作用，我们在基因转移后5天，在大鼠颈动脉中系统给药玫瑰红和腔内绿光，形成血栓，并在血栓形成后3周检测新内膜的生长情况。adlacz感染动脉血流迅速恶化，并在血栓形成后2分钟内消失。相比之下，在照射期间，advwfcp感染动脉的血流至少保留了5分钟。此外，血栓形成和随后的新生内膜生长受到适度抑制。结论;VWF-CP在损伤动脉内的局部表达可能阻止动脉血栓形成和新生内膜的生长。

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.