PDF(Pubmed)
Abstract：
Background: Myocardial infarction (MI) as a consequence of atherosclerosis-associated acute thrombosis is a leading cause of death and disability globally. Antiplatelet and anticoagulant drugs are standard therapies in preventing and treating MI. However, all clinically used drugs are associated with bleeding complications, which ultimately limits their use in patients with a high risk of bleeding. We have developed a new recombinant drug, targ-HSA-TAP, that combines targeting and specific inhibition of activated platelets as well as anticoagulation. This drug is designed and tested for a prolonged circulating half-life, enabling unique thromboprophylaxis without bleeding complications. Methods: Targ-HSA-TAP combines a single-chain antibody (scFv) that targets activated glycoprotein IIb/IIIa on activated platelets, human serum albumin (HSA) for prolonged circulation, and tick anticoagulant peptide (TAP) for coagulation FX inhibition. A non-binding scFv is employed as a non-targeting control (non-targ-HSA-TAP). Its efficacy was investigated in vivo using murine models of acute thrombosis and cardiac ischemia-reperfusion (I/R) injury. Results: Our experiments confirmed the targeting specificity of targ-HSA-TAP to activated platelets and demonstrated effective prevention of platelet aggregation and thrombus formation, as well as FXa inhibition in vitro. Thromboprophylactic administration of targ-HSA-TAP subcutaneously in mice prevented occlusion of the carotid artery after ferric chloride injury as compared to non-targ-HSA-TAP and PBS-control treated mice. By comparing the therapeutic outcomes between targ-TAP and targ-HSA-TAP, we demonstrate the significant improvements brought by the HSA fusion in extending the drug\'s half-life and enhancing its therapeutic window for up to 16 h post-administration. Importantly, tail bleeding time was not prolonged with targ-HSA-TAP in contrast to the clinically used anticoagulant enoxaparin. Furthermore, in a murine model of cardiac I/R injury, mice administered targ-HSA-TAP 10 h before injury demonstrated preserved cardiac function, with significantly higher ejection fraction and fractional shortening, as compared to the non-targ-HSA-TAP and PBS control groups. Advanced strain analysis revealed reduced myocardial deformation and histology confirmed a reduced infarct size in targ-HSA-TAP treated mice compared to control groups. Conclusion: The inclusion of HSA represents a significant advancement in the design of targeted therapeutic agents for thromboprophylaxis. Our activated platelet-targeted targ-HSA-TAP is a highly effective antithrombotic drug with both anticoagulant and antiplatelet effects while retaining normal hemostasis. The long half-life of targ-HSA-TAP provides the unique opportunity to use this antithrombotic drug for more effective, long-lasting and safer anti-thrombotic prophylaxis. In cases where MI occurs, this prophylactic strategy reduces thrombus burden and effectively reduces cardiac I/R injury.
摘要：
背景：与动脉粥样硬化相关的急性血栓形成导致的心肌梗塞（MI）是全球死亡和残疾的主要原因。抗血小板和抗凝血药物是预防和治疗MI的标准疗法。然而,所有临床使用的药物都与出血并发症有关，这最终限制了它们在出血风险高的患者中的使用。我们开发了一种新的重组药物，targ-HSA-TAP,结合了活化血小板的靶向和特异性抑制以及抗凝。这种药物的设计和测试延长了循环半衰期，使独特的血栓预防没有出血并发症。方法：Targ-HSA-TAP结合了单链抗体（scFv），该抗体靶向活化血小板上的活化糖蛋白IIb/IIIa，人血清白蛋白（HSA）延长循环，和tick抗凝血肽（TAP）用于凝血FX抑制。非结合scFv用作非靶向对照(非targ-HSA-TAP)。使用急性血栓形成和心脏缺血再灌注（I/R）损伤的小鼠模型在体内研究了其功效。结果：我们的实验证实了targ-HSA-TAP对活化血小板的靶向特异性，并证明了有效预防血小板聚集和血栓形成。以及FXa体外抑制。与非targ-HSA-TAP和PBS对照处理的小鼠相比，小鼠皮下预防血栓施用targ-HSA-TAP可防止氯化铁损伤后颈动脉闭塞。通过比较targ-TAP和targ-HSA-TAP的治疗效果，我们证明了HSA融合在延长药物的半衰期和延长其治疗窗口方面带来的显着改善，直至给药后16小时。重要的是,与临床使用的抗凝血依诺肝素相比,targ-HSA-TAP并未延长尾部出血时间.此外，在小鼠心脏I/R损伤模型中，在损伤前10小时给予targ-HSA-TAP的小鼠表现出保留的心功能，具有明显更高的射血分数和缩短分数，与非targ-HSA-TAP和PBS对照组相比。高级应变分析显示，与对照组相比，targ-HSA-TAP治疗的小鼠的心肌变形减少，组织学证实梗塞面积减少。结论：HSA的纳入代表了设计用于血栓预防的靶向治疗剂的显着进步。我们的活化血小板靶向targ-HSA-TAP是一种高效的抗血栓药物，具有抗凝血和抗血小板作用，同时保持正常止血。targ-HSA-TAP的长半衰期为使用这种抗血栓药物提供了独特的机会，持久和更安全的抗血栓预防。如果发生MI，这种预防策略降低了血栓负担,并有效减少了心脏I/R损伤.
