Development of the Plasmin-independent Thrombolytic Agent for the Treatment of Acute Ischemic Stroke

项目摘要 由血管内血栓引起的血栓形成是三种疾病中最常见的基本病理。 主要心血管疾病：缺血性心脏病、中风和静脉血栓栓塞症。重要的是 高发病率及其致命后果要求寻找安全有效的溶栓剂 酶，在过去的几十年里仍然广泛存在。尽管付出了努力，但目前 溶栓剂有很大的缺点，包括出血并发症。目前所有的溶栓剂 参与了纤溶酶原对纤溶酶的激活。不幸的是，它的非特异性蛋白分解活性 纤溶酶降解与止血和伤口愈合有关的必要蛋白质。因此，纤溶酶的临床应用- 依赖型溶栓治疗受到限制，要求在中风后3小时内开始治疗。 以避免致命的出血并发症。对新的溶栓剂的需求仍然迫切需要改进 无需担心出血和组织损伤并发症的治疗。 SNJ Pharma，Inc.发现出现HtrA1(高温需求A1，命名为凝血酶) 对血管内血栓具有很强的溶栓活性，同时允许伤口正常愈合。不像所有人 目前可用的溶栓剂，HtrA1蛋白酶不能激活纤溶酶原至纤溶酶，这是一种非特异性的 与溶栓治疗的致命出血并发症有关的蛋白酶。HtrA1的高度特异性 酶的活性能够选择性地降解病理性血栓，同时保留止血凝块， 消除了大出血的风险。活体小鼠模型，包括伤口切除和尾巴出血试验， 与目前相比，HtrA1处理的动物在伤口愈合方面没有表现出损害。 溶栓剂。此外，HtrA1完全溶解了尾部血栓形成小鼠的血栓 和血管内血栓的小鼠肺栓塞时，静脉注射，导致 抢救出血栓栓塞症。在此，在确认HtrA1活性的特异性和保存有益的 我们的目标是评估HtrA1蛋白酶的治疗效果及其在止血血栓中的潜力。 体外取栓和体内光血栓形成治疗急性缺血性卒中 模特。我们成功地完成了这项具有第一个纤溶酶非依赖性溶栓酶的提议 目前HtrA1蛋白酶是一种革命性的治疗AIS的候选药物，而不存在有限的 治疗窗内无出血和组织损伤并发症。

Project Summary Thrombosis caused by intravascular blood clots is the most common underlying pathology of the three major cardiovascular disorders: ischemic heart disease, stroke, and venous thromboembolism. The significantly high incidence rate, as well as its fatal consequences, has called the search for safe and effective thrombolytic enzymes, which remained extensive throughout the past several decades. Despite the effort, current thrombolytics have significant drawbacks, including bleeding complications. All the current thrombolytic agents are involved in the activation of plasminogen to plasmin. Unfortunately, the non-specific proteolytic activity of plasmin degrades essential proteins involved in hemostasis and wound healing. Thus, the clinical use of plasmin- dependent thrombolytic therapy has been limited, requiring the initiation of treatment within 3 hours from stroke onset to avoid fatal hemorrhagic complications. A need for new thrombolytics remains urgent for improved treatment without concerns of hemorrhage and tissue injury complications. SNJ Pharma, Inc. identified HtrA1 (high-temperature requirement A1, named as thrombase) that appears to exert strong thrombolytic activity on intravascular clots while permitting normal wound healing. Unlike all currently available thrombolytics, HtrA1 protease does not activate plasminogen to plasmin, a non-specific protease responsible for fatal hemorrhagic complications from thrombolytic therapy. The high specificity of HtrA1 enzyme activity enables selective degradation of pathological thrombi while preserving hemostatic clots, removing the risk of massive bleeding. In vivo murine models, including wound excision and tail bleeding assays, demonstrated that animals treated with HtrA1 exhibited no damage in wound healing in contrast to current thrombolytics. In addition, HtrA1 administration completely dissolved blood thrombi in mice with tail thrombosis and intravascular thrombi in mice with pulmonary embolism when administrated intravenously, resulting in rescued thromboembolism. Here, upon confirming the specificity of HtrA1 activity and preservation of beneficial hemostatic clots, we aim to evaluate the therapeutic efficacies of HtrA1 protease and its potential for the treatment of acute ischemic stroke (AIS) using in vitro thrombectomy model and in vivo photothrombotic AIS model. Our successful completion of this proposal with the first plasmin-independent thrombolytic enzyme will present HtrA1 protease as a revolutionary therapeutic candidate for AIS without the drawback of a limited treatment window in the absence of hemorrhage and tissue injury complications.