微粒在机械取栓治疗中的标记物作用研究

Stroke,one of the 3 major life threathening diseases, is leading cause of disability and second cause of mortality. The most effective therapy is quick reperfusion. As technique improved, intra-arterial therapy, especially mechanical embolectomy is currently believed most promising in treating acute ischemic stroke parients, for its longer safety window and higher recanalization rate. However, the longer ischemia sustained, the more severe complications (hemorrhage et al.) and poorer prognoses would occur, which required urgently predictive markers for post-theraputic complications and prognoses before mechanical embolectomy therapy. Circulating microparticles (MPs) were identified related with pathogenesis, complications and prognoses of cerebral vascular diseases, especially those intra-arterial MPs surrounding brain infarction presented extremely high value in stroke research. In this project, we use progressive translational research tactics to combine circulating MPs in basic research and predictive markers in clinical research, from rat MCAO animal model to ischemic stroke patient, from occlusive artery to peripheral vein, to identify MPs changes (origins, amount and ratios) those are most related with complications and prognoses, which would provide necessary evidences and targets in stroke study. Further, we combined circulating MPs and neuroimaging to explore their function as predictive markers for complications and prognoses after mechanical embolectomy therapy, which is extremely significant in improving its clinical safety and effectiveness.

脑卒中发病率、致残率、致死率高；溶栓治疗是美国FDA唯一批准的治疗方法。随着技术的发展，血管内治疗，特别是机械取栓安全窗长，再通率高，被认为适于就诊率最高的缺血性脑卒中患者急性期治疗；但是长时间缺血再通后容易引发脑出血等并发症。因此，亟需相关预警性标记物。血液中微粒改变与脑血管疾病密切相关；尤其是脑卒中梗死部位动脉血中微粒，极具研究价值。在本项目中我们采取递进的转化型研究思路，将基础分子生物学研究"血液中微粒"与临床应用研究"预警标记物"紧密结合，从经微导管大鼠MCAO动物模型再到临床机械取栓治疗缺血性脑卒中患者，尤其是从梗死灶动脉血到外周血的血液微粒来源、含量及其比值的分析，确定与并发症及预后密切相关的微粒改变指标，层层递进探索脑卒中发病进程中起到关键作用的靶点；通过联合血液微粒与神经影像学数据，共同作为机械取栓治疗后并发症及预后的预警性标记物，提高机械取栓治疗的安全、有效性。

脑卒中发病率、致残率、致死率高；溶栓治疗是美国FDA唯一批准的治疗方法。血管内治疗打破治疗时间窗的概念壁垒，临床中不断延长急性脑梗死发生后治疗时间。但是，仍然存在缺血再通后脑出血等危及生命的并发症。因此，亟需预后标记物，提示血管再通治疗后不良事件发生情况。.外周血中泡膜结构内含蛋白质、核酸和脂类，其中蛋白质和核酸受到磷脂膜保护不被降解而稳定存在。Microvesicle（MVs）是在肿瘤领域广泛研究的标记物靶点，但在脑血管病领域尚不多见。外周血中大部分MVs来自内皮细胞，随着血脑屏障的破坏，可能会有神经元或其他胶质细胞释放的MVs。MVs理化特点改变及其内容物在急性脑梗死预后标记物研究中极具研究价值。.离体实验：.1. 6hr OGD比6hr缺氧造成更多细胞死亡，只有6hr OGD减少MVs的释放和组分；.2. 12hr比6hr缺氧造成更多细胞损伤，不影响MVs释放和组分，但是MVs内总RNA明显减少；而细胞内总RNA未见明显改变。.3. 6hr OGD后，细胞和释放的MVs中miR126和miR155均减少，且二者无显著差异；细胞释放的miR296明显减少，MVs中miR296未见明显减少。.4. 6hr和12hr缺氧处理后释放的MVs内miRNA Array结果尚在统计中。.在体实验：.使用75min tMCAO和pMCAO模拟不同预后的在体模型：.1. pMCAO比tMCAO模型鼠，术后24小时梗死体积更大，mNSS评分更高，死亡率越高；.2. pMCAO和 tMCAO模型鼠，术后3小时后MVs内miR126无病变程度相关性变化，而血清中miR126在pMCAO中明显降低。.3. MVs内miR126和血清中miR126无相关性；血清内miR126与梗死体积具有相关性，MVs内mi126无此相关性。.4. pMCAO和tMCAO模型鼠，血清和MVs均无法检测到miR124。.研究意义.1. 本研究验证外周血中内皮细胞释放的MVs物理特点及其内总RNA，miRNA对不同程度的缺血/缺氧处理存在特异性改变，适合作为缺血性脑血管病再通预后的标记物靶标。.2. MVs内miR126缺乏预后相关特异性，但是血清miR126具有预后相关特异性。但是需要更多实验验证。.3. 更多的研究可以采用组学的方法探讨MVs内核酸变化在预后相关标记物中的作用。