Supervillin基因变异对缺血性卒中阿司匹林抵抗的影响及机制研究

Aspirin is the traditional first-line anti-platelet drug; its clinical use however is compromised by its high rate of resistance. It has been shown that the rs17834991 and rs7070678 of Supervillin (SVIL) gene were closely related to the aspirin resistance in Caucasians. SVIL is an actin-binding protein that is an important regulator of actin filament assembly and disassembly. Both the CHANCE and PRINCE were multicenter randomized controlled trials, in patients with acute minor ischemic stroke or transient ischemic attack (TIA) in China. Only rs17834991 has been confirmed to be associated with the aspirin resistance, both in clinical and biochemical, in these two trials. Meanwhile, the carriages of the C allele were related to the upregulation of SVIL mRNA in our preliminary experiment. However, it is still unclear that whether rs17834991 is an independent risk factor of aspirin resistance, and how it works. So, we will study the effect of SVIL gene variant on aspirin resistance in an existing prospective cohort. And then, we aim to establish the megakaryocyte cell line with the rs17834991 variant and the arterial thrombosis model based on the C57BL/6 mouse with the same variant. Further, the underlying mechanism of SVIL gene variant on aspirin resistance will be investigated by the changes of activation markers, cell signal pathways, metabolic pathways, cell morphology, cytoskeleton and aggregation of the platelets, and thus its effect on thrombogenesis. We expect to offer new target for individual anti-platelet therapy in patients with ischemic stroke and TIA.

阿司匹林是最经典的一线抗血小板药物，但阿司匹林抵抗严重困扰临床。新近研究发现，Supervillin(SVIL)基因变异与欧美人群阿司匹林抵抗有关。SVIL是Actin结合蛋白，对维持血小板细胞骨架的动态稳定具有重要作用。申请人前期在两项多中心随机对照研究的亚组分析中发现，仅rs17834991位点与中国缺血性卒中/TIA患者阿司匹林抵抗密切相关；同时发现该位点变异上调了SVIL基因mRNA表达，但具体机制尚不清楚。本项目将立足于前期研究结果，在现有队列中前瞻性研究SVIL基因变异对卒中患者阿司匹林抵抗的影响；建立rs17834991变异的巨核细胞模型及该位点变异的C57BL/6小鼠颈动脉血栓模型，从血小板活化、代谢、聚集及血栓形成等方面，探讨SVIL基因变异在阿司匹林抵抗中的作用机制，为指导个体化抗血小板治疗提供新思路和新靶点。

阿司匹林是最经典的一线抗血小板药物，但阿司匹林疗效抵抗长期困扰临床。近年来联合抗血小板、强化他汀治疗进一步降低了缺血性卒中/TIA患者的卒中复发率，残余风险的寻找和控制更具挑战性。本项目在前期研究的基础上，开展以下研究：1、在已建立的队列中，阿司匹林治疗7天后，尿液中阿司匹林代谢产物11-dh-TxB2水平显著降低；携带G等位基因者代谢产物水平有低于非携带者的趋势；携带G等位基因的患者阿司匹林治疗后残余血小板高反应性比例有下降趋势，但该位点不同基因型之间mRNA水平无显著差别。2、胆固醇分解代谢关键酶基因CYP7B1的突变可导致痉挛性截瘫的临床表型，分别对临床变量、脑脊液27-羟基胆固醇或神经丝蛋白和定量MRI特征分别进行标准化效应量估计，发现T9横截面积是评价其治疗疗效最有效的指标，为探索新治疗策略提供有价值的评价结局。3、对CMT2患者采用全外显子组测序，42%发现MFN2基因致病突变；患者mt-DNA水平与其神经病变评分CMTNS与呈负相关。本课题为缺血性卒中患者抗血小板二级预防后残余风险的寻找提供了研究数据；单基因病遗传背景同质化高，基于此深入研究，将有望为散发性疾病提出寻找分子机制及治疗靶点的新线索，加快转化速度。课题组仍在本项目研究结果的基础上进行后续的延伸性研究工作。