Antithrombotic Aptamers and Antidotes

描述（由申请方提供）：本提案中测试的中心假设是抗凝适体及其解毒剂代表了控制凝血和预防血栓形成的安全有效方法。在该资助的上一个资助周期中，我们测试了这样一种假设，即适体是一类化合物，其活性可以很容易地被解毒剂逆转。我们确定了这一假设是正确的，并在此过程中开发了可以抑制几种凝血因子（包括因子VIIa、IXa、Xa和凝血酶）活性的适体，并产生了两类解毒剂，基于抗凝血肽的解毒剂和通用解毒剂，它们可以快速逆转此类适体的抗凝活性。此外，我们还产生了针对血小板蛋白GP IIb/IIIa和VWF的适体-解毒剂对，并证明了它们抑制血小板功能的能力。因此，我们现在有一组新的解毒剂可控的抗凝剂，我们将在本提案中使用，以测试的总体假设，这种适配体和解毒剂代表了一种安全有效的方法来控制凝血和血小板功能，在各种临床相关的设置。这种控制在抗凝治疗的情况下尤其有价值，因为给予此类治疗可能会引起严重出血等副作用，从而增加患者的发病率和死亡率。我们的三个具体目标是：1）阐明适体用于抑制凝血因子活性的机制。2)评估抑制“安全”抗凝剂靶标的适体与可逆抑制“经验证”抗凝剂靶标的适体-解毒剂对的净治疗获益。3)确定哪些抗凝适体可有效抑制心肺转流手术中的凝血，并确定寡核苷酸和通用解毒剂是否可在手术后快速安全地逆转此类适体的作用。 公共卫生相关性：需要抗血栓适体和解毒剂抗凝剂和/或抗血栓治疗来进行许多临床程序，包括经皮冠状动脉介入术（PCI，“血管成形术”）、冠状动脉旁路移植术（CABG）手术和其他手术以及透析。该疗法也被用作许多血栓性疾病的治疗，包括急性冠状动脉综合征（心肌梗死和不稳定型心绞痛）、深静脉血栓形成、肺栓塞和外周血管疾病。抗凝和抗血栓治疗的主要毒性和局限性是严重的药物性出血。例如，在超过50%的CABG手术和10-15%的PCI手术中需要由于失血而输血。在这项拨款申请中，我们建议开发和测试一些新的抗凝剂和抗血小板剂沿着解毒剂分子，用于这种新的治疗。我们相信，这种解毒剂可控的治疗剂的产生将导致许多心血管疾病的更安全的治疗，并改善公众的整体健康和福利。

DESCRIPTION (provided by applicant): The central hypothesis being tested in this proposal is that anticoagulant aptamers and their antidotes represent a safe and effective means of controlling coagulation and preventing thrombosis. In the previous funding cycle of this grant, we tested the hypothesis that aptamers are a class of compounds whose activity can be readily reversed by antidotes. We determined that this hypothesis is correct and in the process developed aptamers that can inhibit the activity of several coagulation factors including factors VIIa, IXa, Xa and thrombin, and generated two classes of antidotes, oligonucleotide-based antidotes and universal antidotes, that can rapidly reverse the anticoagulant activity of such aptamers. Furthermore, we also generated aptamer-antidote pairs against the platelet proteins GP IIb/IIIa and VWF and have demonstrated their ability to inhibit platelet function. Thus we now have a set of novel antidote-controllable anticoagulant agents that we will use in this proposal to test the overall hypothesis that such aptamers and antidotes represent a safe and effective approach to control coagulation and platelet function in a variety of clinically relevant settings. Such control is especially valuable in the case of anticoagulant therapy because administration of such therapeutics can induce side effects such as severe bleeding that increase patient morbidity and mortality. Our three specific aims are: 1) to elucidate the mechanism(s) that aptamers utilize to inhibit coagulation factor activity. 2) To assess the net therapeutic benefit of aptamers that inhibit "safe" anticoagulant targets versus aptamer-antidote pairs that reversibly inhibit "validated" anticoagulant targets. 3) To determine which anticoagulant aptamers can effectively inhibit coagulation in the setting of cardiopulmonary bypass surgery and determine if oligonucleotide and universal antidotes can rapidly and safely reverse the effects of such aptamers following surgery. PUBLIC HEALTH RELEVANCE: Antithrombotic aptamers and antidotes anticoagulant and/or antithrombotic therapy is required to perform a number of clinical procedures including percutaneous coronary interventions (PCI, "angioplasties"), coronary artery bypass graft (CABG) surgery and other surgeries, as well as dialysis. This therapy is also used as a treatment for a number of thrombotic diseases including acute coronary syndromes (myocardial infarction and unstable angina), deep vein thrombosis, pulmonary embolism, and peripheral vascular disease. The major toxicity and limitation of anticoagulant and antithrombotic therapy is serious drug-induced bleeding. For example, transfusions due to blood loss are required in upwards of 50% of CABG surgeries and 10-15% of PCI procedures. In this grant application, we propose to develop and test a number of new anticoagulant and antiplatelet agents along with antidote molecules for this new therapeutics. We believe the generation of such antidote controllable therapeutic agents will lead to safer treatment of a number of cardiovascular disorders and improve the overall health and welfare of the public.