基于环状RNA差异表达调控缺血半暗带形成对急性缺血性脑卒中小鼠的干预作用

Stroke has been the main cause of mortality and the first cause of disability in chinese residents. FDA recommend the preferred recanalization treatment for ischemic stroke is rt-PA intravenous thrombolysis after time window and patients evaluation, but it is difficult to predict the hemorrhage or aggravation after evaluation-thrombolysis in most population which is burning question and technical difficulties should be sloved for acute ischemic stroke patients followed thrombolysis.Recent studies show that circular RNAs are more largely and widely expressed in neural systems than other tissues. In addition, the highly conservative sequence expressed among species have great significance for the clinical application. Moreover, the cirlcular RNAs are not only assemble lots of miRNA as sponges, but also high affinity to bind miRNA than RNA, and play an important regulator on the transcription. These all provide a new direction and potential target for time window monitor before thrombolysis in acute ischemic stroke and neural diseases. We suspect the changes of circular RNAs are accompanied by acute ischemic stroke, and could be regulated to delay the formation of infarcts and retain the penumbra tissues by miRNA and other pathway for recanalization. According to the circular RNA sequencing results of mouse models, we will screen differentially expressed circular RNAs between infarct and penumbra tissues in acute ischemic stroke mice. Combined with the experimental results in vivo and in vitro, and bioinformatics analysis of circular RNA in the nets of miRNA- circular RNAs - RNA to explain the regulatory mechanism. Regulate the expression of circular RNA could become an important tool to extend the thrombolysis time window and the important targets to delay the progress of acute ischemic cerebral infarction.

脑卒中现已成为中国居民最主要的死亡病因和首位致残原因。美国FDA对急性缺血性脑卒中唯一推荐治疗为rt-PA静脉溶栓,但由于溶栓时间窗个体差异及梗死灶周边缺血半暗带不确定,无法判断该治疗引起的出血甚至死亡等可能性后果,因此对患者溶栓时间窗延长和缺血半暗带个体化监测是保证血管再通治疗、预防溶栓并发症的首要问题和技术难点。近来研究发现，相较其他组织，环状RNA在神经系统中大量广泛存在且物种间序列高度保守,加之环状RNA比其他线性RNA稳定、与miRNA亲和力高于miRNA-mRNA结合在转录网络中扮演重要调控作用,使之成为神经疾病研究最具潜力的新晋成员。结合前期卒中小鼠模型脑组织测序结果，我们将通过qRT-PCR和FISH筛选不同脑区差异表达的环状RNA，监测环状RNA调控表达后梗死灶和缺血半暗带的形成，结合体外实验及生物信息学分析环状RNA在延长溶栓时间窗改善急性缺血卒中进展的作用及可能机制。

1、背景.脑卒中现已成为中国居民最主要的死亡病因和首位致残原因。美国FDA对急性缺血性脑卒中唯一推荐治疗为rt-PA静脉溶栓,但由于溶栓时间窗个体差异及梗死灶周边缺血半暗带不确定,无法判断该治疗引起的出血甚至死亡等可能性后果,因此对患者溶栓时间窗延长和缺血半暗带个体化监测是保证血管再通治疗、预防溶栓并发症的首要问题和技术难点。近来研究发现，相较其他组织，环状RNA在神经系统中大量广泛存在且物种间序列高度保守,加之环状RNA比其他线性RNA稳定、与miRNA亲和力高于miRNA-mRNA结合在转录网络中扮演重要调控作用,使之成为神经疾病研究最具潜力的新晋成员。.2、主要研究内容、重要结果、关键数据.通过小鼠局灶性脑缺血模型挖掘缺血相关的环状RNA，我们结合体外实验、临床研究、生物信息学分析环状RNA在急性缺血卒中的生物标记作用及可能机制，找出作为潜在生物标记作用的环状RNA的可能作用机制。发现circOGDH可作为缺血半暗带的血液生物标记物，能通过外泌体分泌到血浆，指示神经元的损伤，该机制主要与mirna吸附作用相关。同时，circPHKA2和circBBS2也可能作为生物标记物。但具体机制未探讨。.3、急性缺血脑卒中的诊断主要靠影像，而本研究可以弥补无影像设备的医院的诊断，同时，发现以circOGDH为靶标的改善神经元损伤的新方向。同时，在这些研究基础上，我们引入了外泌体的作用，并同时，将缺血脑卒中的治疗做了展望，具有重要临床意义和科研价值。