活血化瘀中药通过血小板P2Y12受体后信号通路调控氯吡格雷低反应的机制研究

Clopidogrel is one of main clinical antiplatelet drugs. Clopidogrel low responsiveness (CLR) is an independent risk factor for cardiovascular events. P2Y12 receptor-mediated signaling pathways not only greatly affect clopidogrel reactivity, but maybe a potential therapeutic target of CLR. The effective compounds of rhizoma ligustici wallichii and radix paeoniae rubra, two important blood-activating and stasis-resolving herbs, have significant antiplatelet effects. Whether these two herbs play a role in improving CLR through regulating P2Y12 post-receptor signaling pathways has not yet been reported. Therefore, this study is designed to research the regulatory mechanism of the effective compounds of rhizoma ligustici wallichii and radix paeoniae rubra on CLR via in vitro experiment with the peripheral platelets taken from CLR group and healthy group. Besides, the study is also designed to research the impact of effective compounds of these two herbs on P2Y12 post-receptor signaling pathways at two respects (plaque stability and coronary microthrombosis) in apoE-knockout mice model with atherosclerosis and rat model with coronary microthrombosis, respectively. Taken together, the present study will provide experimental evidences of integrated Chinese-Western antiplatelet therapy for coronary heart disease patients with CLR.

氯吡格雷是临床主要的抗血小板药物，其低反应是心血管事件发生的独立危险因素。P2Y12受体后信号通路不仅是影响氯吡格雷反应性的重要通路，也是干预氯吡格雷低反应的可能作用靶点。活血化瘀中药川芎、赤芍有效部位皆有抗血小板作用，但其可否通过调控P2Y12受体后信号通路发挥改善氯吡格雷低反应作用，尚未见报道。本研究通过体外人血小板实验（氯吡格雷低反应人群、健康人），研究活血化瘀中药川芎、赤芍有效部位对氯吡格雷低反应的调控机制；通过apoE基因敲除小鼠动脉粥样硬化模型、冠脉微血栓大鼠模型，从斑块稳定性和微血栓形成两个层面，研究活血化瘀中药川芎、赤芍有效部位对P2Y12受体后信号通路的调控作用，以为氯吡格雷低反应的冠心病人群的中西医结合抗血小板治疗提供实验依据。

氯吡格雷低反应是心血管事件发生的独立危险因素。氯吡格雷低反应可导致血小板残余高反应性，血小板P2Y12受体下游信号通路的活化是其关键病理环节。研究证实，活血化瘀中药具有抗血小板的作用。那么，活血化瘀中药是否可改善氯吡格雷低反应，其机理是否与血小板P2Y12受体后信号通路有关？目前尚未见报道。针对氯吡格雷低反应这一重要临床问题，本课题以P2Y12受体后的AC/cAMP和PI3K/Akt信号通路为切入点，开展体外血小板实验，研究活血化瘀中药对氯吡格雷低反应的调控效应和机制；在体建立动脉粥样硬化小鼠模型和冠脉微血栓大鼠模型，探讨活血化瘀中药通过P2Y12受体后信号通路对动脉粥样硬化及冠脉微循环的调控作用和机制。研究证实，活血化瘀中药可有效抑制ADP诱导的血小板活化聚集，改善血小板高反应性，进而发挥抗动脉粥样硬化、抑制冠脉微血栓形成的作用，其机制主要与激活血小板AC/cAMP通路、促进VASP蛋白磷酸化有关；但在血小板P2Y12受体得到充分抑制、血小板反应性较低的情况下，活血化瘀中药干预不会进一步抑制血小板活性。本课题不仅为冠心病氯吡格雷低反应提供了新的治疗思路，也为活血化瘀中药参与冠心病二级预防提供了有力的数据支持。