RNA Aptamer-directed Anticoagulant Therapy

描述(由申请人提供)：历史上，普通肝素曾用于治疗和预防血栓栓塞性疾病。然而，由于与肝素相关的并发症(如出血)，低分子肝素(LMWHs)已经被开发出来，并被用来取代普通肝素。低分子肝素已被证明是有效的抗血栓药物；然而，低分子肝素的作用不能轻易逆转，而普通肝素可以被硫酸鱼精蛋白逆转。这项建议的总体目标是开发一种抗凝血酶(ATIII)特异性RNA适配子，将低分子肝素的安全性和有效性与普通肝素的可逆性结合起来。为了实现这一目标，将开发一种用于该适配子的寡核苷酸解毒剂，该解毒剂将用于快速逆转该适配子的抗凝特性。 针对凝血因子Xa的RNA适配子和RNA适配子解毒剂的开发证实了这一概念。与该小组合作，将开发一种解毒剂控制的ATIII特异性RNA适配子。该适配子将通过与ATIII的D-螺旋结合来模拟LMWH的作用，并增强ATIII对因子Xa的抑制。这种适配子/解毒剂对将比低分子肝素具有优势，因为它不仅能够控制类似于低分子肝素的血栓形成，而且解毒剂的可用性将允许更好的治疗调节和干预。该提案中提议的实验将使用体外和体内方法来表征这一家族的抗凝血酶特异性RNA适配子。

DESCRIPTION (provided by applicant): Historically, unfractionated heparin has been used in the treatment and prevention of thromboembolic disorders. However, due to complications associated with heparin (such as bleeding), low molecular weight heparins (LMWHs) have been developed and are being used in place of unfractionated heparin. LMWHs have proven effective as antithrombotic agents; however, the effects of LMWHs cannot be readily reversed while unfractionated heparin can be reversed by protamine sulfate. The overall goal of this proposal is to develop an antithrombin (ATIII)-specific RNA aptamer that will combine the safely and efficacy of LMWH with the reversibility of unfractionated heparin. To accomplish this goal, an oligonucleotide antidote for this aptamer that will be used to rapidly reverse the anticoagulant properties of the aptamer will be developed. Proof of this concept is established by the development of an RNA aptamer and RNA aptamer antidote directed against coagulation factor Xa. In collaboration with this group, an antidote-controlled ATIII-specific RNA aptamer will be developed. This aptamer will mimic the action of LMWH by binding to the D-helix of ATIII and enhance ATIII inhibition of factor Xa. This aptamer/antidote pair will have advantages over LMWHs because it will not only be able to control thrombosis similar to LMWHs but the availability of an antidote will allow for better therapeutic regulation and intervention. The experiments proposed in this proposal will characterize this family of antithrombin-specific RNA aptamers using both in vitro and in vivo approaches.