First Selective 12-LOX Inhibitor, ML355, Impairs Thrombus Formation and Vessel Occlusion In Vivo With Minimal Effects on Hemostasis.
First Selective 12-LOX Inhibitor, ML355, Impairs Thrombus Formation and Vessel Occlusion In Vivo With Minimal Effects on Hemostasis.
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DOI：
10.1161/atvbaha.117.309868
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发表时间：
2017-10
期刊：
影响因子：
--
通讯作者：
Holinstat M
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文献类型：
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作者：
Adili R;Tourdot BE;Mast K;Yeung J;Freedman JC;Green A;Luci DK;Jadhav A;Simeonov A;Maloney DJ;Holman TR;Holinstat M
维持止血需要足够的血小板反应性。然而，过度的血小板反应性也会导致闭塞性血栓的形成。12-脂氧合酶（12-LOX）是一种在血小板中高度表达的加氧酶，已被证明在体外调节血小板功能和血栓形成，支持12-LOX在体内血栓形成调节中的关键作用。然而，在体内靶向12-LOX的药理学能力迄今尚未确定。在这里，我们研究了第一种高选择性的12-LOX抑制剂ML355对体内血栓形成和止血的影响。ML355剂量依赖性抑制人血小板聚集和12-LOX氧脂生成，质谱证实。有趣的是，ML355的抗血小板作用在体外暴露于高浓度凝血酶后被逆转。体外流室实验证实，与阿司匹林相比，ML355处理的全血中，人血小板粘附和动脉剪切处胶原蛋白上的血栓形成被减弱。经药代动力学评价，小鼠口服ML355的血药浓度合理。在fecl3诱导的小鼠肠系膜和激光诱导的微动脉血栓模型中，ML355治疗可损害血栓生长和血管阻塞。重要的是，在小鼠隐静脉激光消融或cremaster微血管激光诱导破裂模型中，ML355治疗后的止血栓形成和出血最小。我们的数据有力地支持12-LOX是体内血小板反应性的关键决定因素，ML355抑制血小板12-LOX可能代表了一种新的抗血小板治疗方法。
Adequate platelet reactivity is required for maintain hemostasis. However, excessive platelet reactivity can also lead to the formation of occlusive thrombi. 12-lipoxygenase (12-LOX), an oxygenase highly expressed in the platelet, has been demonstrated to regulate platelet function and thrombosis ex vivo, supporting a key role for 12-LOX in the regulation of in vivo thrombosis. However, the ability to pharmacologically target 12-LOX in vivo has not been established to date. Here, we studied the effect of the first highly selective 12-LOX inhibitor, ML355, on in vivo thrombosis and hemostasis. ML355 dose-dependently inhibited human platelet aggregation and 12-LOX oxylipin production, as confirmed by mass spectrometry. Interestingly, the antiplatelet effects of ML355 were reversed following exposure to high concentrations of thrombin in vitro. Ex vivo flow chamber assays confirmed that human platelet adhesion and thrombus formation at arterial shear over collagen were attenuated in whole blood treated with ML355 comparable to aspirin. Oral administration of ML355 in mice showed reasonable plasma drug levels by pharmacokinetic assessment. ML355 treatment impaired thrombus growth and vessel occlusion in FeCl3-induced mesenteric and laser-induced cremaster arteriole thrombosis models in mice. Importantly, hemostatic plug formation and bleeding following treatment with ML355 was minimal in mice in response to laser ablation on the saphenous vein or in a cremaster microvasculature laser-induced rupture model. Our data strongly supports 12-LOX as a key determinant of platelet reactivity in vivo and inhibition of platelet 12-LOX with ML355 may represent a new class of antiplatelet therapy.