Antithrombotic Aptamers and Antidotes

 描述(由申请人提供)：四个相互关联但独立的假设正在本提案中进行检验。A)适配子可以作为分子探针来识别凝血因子蛋白水解酶上重要的外切子，B)抑制接触途径中凝血因子的外切结合适配子可以在不增加出血的情况下限制血栓形成，C)两个外切结合适配子的组合以及适配子和小分子活性部位抑制物的组合代表了有效的、但快速可逆的抗凝策略，可以支持体外循环手术和D)。靶向接触途径因子的胞外结合因子IX/IXa适配子将比靶向共同途径因子更有效地限制因子Xa和凝血酶的产生以及在接受经皮冠状动脉介入治疗的患者中的炎症反应。每一项调查都合理地建立在本奖项当前供资周期所取得的重要成果的基础上。我们的具体目标是：目标1：利用适体识别凝血因子XIIa、Xia、IXa、Xa、VIIa和激肽释放酶的外切点。目的：评价靶向接触途径因子外显子的适配子作为安全有效的抗血栓药物的能力。目的：探讨A)适体为基础的抑制剂与B)为基础的Xa因子和凝血酶活性部位抑制剂的联合应用对体外循环(CPB)是否能产生快速安全的抗凝作用，以及解毒剂是否能快速安全地中和CPB后的抗凝作用。目的4：确定我们的凝血因子IXa适配子是否比比伐卢定更有效地限制接受经皮冠状动脉介入治疗的急性冠脉综合征患者凝血酶和凝血因子Xa的产生，以及这是否能减少此类患者的炎症。

 DESCRIPTION (provided by applicant): Four interrelated but independent hypotheses are being tested in this proposal. A) Aptamers can serve as molecular probes to identify functionally important exosites on coagulation factor proteases, B) Exosite-binding aptamers that inhibit coagulation factors in the contact pathway can limit thrombosis without increasing bleeding, C) Combinations of two exosite-binding aptamers and combinations of an aptamer and small molecule active site inhibitor represent potent, yet rapidly reversible anticoagulation strategies that can support cardiopulmonary bypass surgery and D). The exosite binding Factor IX/IXa aptamer targeting a contact pathway factor will limit factor Xa and thrombin generation and inflammation more effectively than targeting common pathway factors in patients undergoing PCI. Each of these lines of investigation rationally build upon important results obtained in the current funding cycle of this award. Our specific aims are: Aim 1: To utilize aptamers to identify exosites on coagulation factors XIIa, XIa, IXa, Xa, VIIa and Kallikrein. Aim 2: To evaluate the ability of aptamers targeting exosites on contact pathway factors to act as potent yet safe antithrombotic agents. Aim 3: To elucidate the mechanism by which combinations of A) aptamer-based inhibitors and B) aptamer-based exosite and active site inhibitors of Factor Xa and thrombin synergize and determine if such combinations can produce rapid and safe anticoagulation for cardiopulmonary bypass (CPB) and if antidotes can produce rapid and safe neutralization of anticoagulation following discontinuation of CPB. Aim 4: To determine if our factor IXa aptamer limits thrombin and factor Xa generation more effectively than bivalirudin in ACS patients undergoing PCI and if this results in a reduction in inflammation in such patients.