Department of Experimental Hematology and Biochemistry, Beijing Institute of Radiation Medicine, Beijing, 100850, People's Republic of China.
Center for Pharmacodynamic Research, Tianjin Institute of Pharmaceutical Research, Tianjin, 300462, People's Republic of China.
Drug Des Devel Ther. 2022 Jun 2;16:1667-1678. doi: 10.2147/DDDT.S353088. eCollection 2022.
Recombinant neorudin (EPR-hirudin, EH) was developed through the addition of an EPR (Glu-Pro-Arg) peptide to the amino terminus of hirudin, which can be recognized and cut by coagulation factors XIa (FXIa) and/or Xa (FXa). In this study, the low-bleeding antithrombotic effects of EH were evaluated utilizing experimental models of thrombosis in rabbits and rats to provide a test basis for clinical trials.
The bleeding risks of EH and hirudin were first compared in mice by the tail-clipping method, and then the antithrombotic activity of EH was investigated in a rabbit model of arteriovenous bypass thrombosis and a rat model of thrombotic cerebral infarction.
In mice, intravenous administration of EH at 1.5 mg/kg and 3 mg/kg did not affect the bleeding time compared with normal saline, while the administration of hirudin at 1.5 mg/kg prolonged the bleeding time by over 3 times the administration of normal saline. Furthermore, intravenous administration of EH had a significant dose-dependent inhibitory effect on the formation and development of arteriovenous bypass thrombosis and thrombotic cerebral infarction. Compared with an equimolar dose of hirudin, the antithrombotic effect of EH was similar, while the bleeding side effects were significantly attenuated. Moreover, when the antithrombotic effects were similar, EH had a shorter bleeding time and was associated with less bleeding than low molecular weight heparin (LMWH). EH had a therapeutic effect on thrombotic cerebral infarction without increasing the occurrence of cerebral hemorrhage.
The findings from the preclinical animal models used in this study showed that EH could not only effectively inhibit thrombus formation but also reduce the risk of bleeding.
重组水蛭素（EPR-水蛭素，EH）通过在水蛭素的氨基端添加 EPR（Glu-Pro-Arg）肽而开发，该肽可被凝血因子 XIa（FXIa）和/或 Xa（FXa）识别和切割。在这项研究中，通过兔和大鼠血栓形成实验模型评估了 EH 的低出血抗血栓作用，为临床试验提供了测试基础。
首先通过断尾法比较 EH 和水蛭素的出血风险，然后在兔动静脉旁路血栓形成模型和大鼠血栓性脑梗死模型中研究 EH 的抗血栓活性。
在小鼠中，与生理盐水相比，EH 在 1.5mg/kg 和 3mg/kg 时静脉注射不影响出血时间，而水蛭素在 1.5mg/kg 时给药使出血时间延长超过生理盐水的 3 倍。此外，EH 静脉注射对动静脉旁路血栓形成和血栓性脑梗死的形成和发展具有显著的剂量依赖性抑制作用。与等摩尔剂量的水蛭素相比，EH 的抗血栓作用相似，而出血副作用明显减轻。此外，当抗血栓作用相同时，EH 的出血时间更短，出血比低分子肝素（LMWH）少。EH 对血栓性脑梗死具有治疗作用，不会增加脑出血的发生。
本研究中使用的临床前动物模型的结果表明，EH 不仅可以有效抑制血栓形成，还可以降低出血风险。
