miR-204-5p对心源型脑梗死后出血转化预测作用及机制研究

Hemorrhagic transformation may cause poor prognosis and reduce the utilization rates of thrombolysis and anticoagulation in patients with cardio-embolic stroke. Our previous studies suggested that cardioembolic stroke in China was associated with higher risk of hemorrhagic transformation, and higher plasma MMP-9 concentration in acute phase was an independent predictor of hemorrhagic transformation. What’s more, in a pilot study, we found that microRNA may involve in occurrence of hemorrhagic transformation by regulating MMP-9 expression. Basing on these findings, this project aims to determine plasma miR-204-5p and MMP-9 expression level from peripheral blood in acute phase of cardioembolic stroke, and then evaluate the incidence and characteristics of hemorrhagic transformation in different expression levels of miR-204-5p and MMP-9 to analyze the relationship between hemorrhagic transformation and miR-204-5p/MMP-9; Finally, we will verify whether the expression of MMP-9 protein is regulated by miR-204-5p in vascular endothelial cell model through miRNA mimics or inhibitors. This project can demonstrate the role and mechanism of microRNA in the course of hemorrhagic transformation and will assist the development of a reliable risk prediction model for hemorrhagic transformation in cardioembolic stroke.

出血转化是心源型脑梗死预后差及我国溶栓和抗凝使用率很低的重要原因。我们前期研究提示与国外相比我国心源型脑梗死出血转化风险更高，血浆MMP-9在急性期高水平表达影响出血转化的发生，microRNA可能通过调控MMP-9表达从而促进心源型脑梗死后出血转化发生。本项目拟在上述基础上，测定心源型脑梗死急性期外周血miR-204-5p/MMP-9表达水平，观察其不同表达水平时出血转化发生情况及特征，比较分析miR-204-5p、MMP-9及出血转化间的相互关系；并进一步在表达MMP-9的血管内皮细胞模型中转染miRNA mimics或inhibitors，验证MMP-9蛋白表达是否受miR-204-5p调控，以探讨microRNA在心源型脑梗死后发生出血转化中预测作用及机制，为进一步建立心源型脑梗死出血转化风险预测模型奠定基础，为我国心源型脑梗死溶栓和抗凝患者的选择提供科学依据。

出血转化是心源型脑梗死预后差及我国溶栓和抗凝使用率很低的重要原因。我们前期研究提示与国外相比我国心源型脑梗死出血转化风险更高，血浆MMP-9在急性期高水平表达影响出血转化的发生，microRNA可能通过调控MMP-9表达从而促进心源型脑梗死后出血转化发生。本项目在上述基础上，共连续收集住院心源型脑梗死患者200余例，按照年龄性别进行匹配，最终选择符合纳入标准的患者58例（出血转化组与非出血转化组各29例）进行研究，发现出血转化组血浆样本MMP-9 中位浓度明显高于非出血转化组（319.94 ng/mL、155.99 ng/mL；p=0.010），但两组外周血中miR-204-5p表达水平无统计学差异（p>0.05）; 因而进一步体外实验验证“MMP-9蛋白表达受到miR-204-5p的调控”缺乏临床证据，实际研究工作中未开展。尽管如此，项目组仍对前期探索的另外7种miRNA在外周血的表达进行检测，进一步分析miR-183-5p、miR-21-5p、miR-206、miR-491-5p、miR-211-5p、miR-3123和miR-3145-5p其他7种miRNA对心源型脑梗死后出血转化预测作用。结果提示心源型脑梗死患者发生出血转化前，其miR-21-5p、miR-206 和miR-3123 表达水平上调，可作为预测心源型脑梗死后出血转化的生物标志物，但在临床实践中应注意单个标志物对脑梗死后发生出血转化的独立预测价值有待提升。该研究结果有助于选出低出血转化风险的心源型脑梗死患者，从而提高临床溶栓的安全性。