miRNA-155在大鼠脑缺血/再灌注损伤早期大脑皮层组织中的表达及其意义

目的：探讨微小RNA-155（miRNA-155）在大鼠脑缺血/再灌注损伤早期大脑皮层组织中的表达，初步阐明miRNA-155对脑缺血/再灌注损伤的影响。方法：48只健康成年雄性SD大鼠，随机分为假手术组和脑缺血/再灌注组，每组24只。脑缺血/再灌注组通过Longa等改良线栓法栓塞大鼠右侧大脑中动脉建立脑缺血/再灌注模型，假手术组大鼠只分离血管。采用TTC染色评估各组大鼠脑缺血梗死体积，采用qRT-PCR法检测各组大鼠脑皮层组织中miRNA-155表达水平。结果：与假手术组比较，再灌注24、48和72h时脑缺血/再灌注组大鼠脑缺血梗死体积明显增大（P<0.05），并且随着再灌注时间延长，脑缺血梗死体积逐渐减少。与假手术组比较，再灌注24、48和72 h时脑缺血/再灌注组大鼠脑皮层组织中miRNA-155表达水平明显升高（P<0.05），并且随着灌注时间延长，表达水平逐渐降低。结论：在大鼠脑缺血/再灌注早期大脑皮层组织中miRNA-155高表达，其参与了脑缺血/再灌注损伤过程。

Expression of miRNA-155 in cerebral cortex tissue of rats with cerebral ischemia-reperfusion injury and its significance

Objective: To investigate the expression of microRNA-155(miRNA-155) in the cerebral cortex tissue of the rats with cerebral ischemia-reperfusion injury, and to clarify the effect of miRNA-155 on cerebral ischemia-reperfusion injury.Methods: A total of 48 healthy adult male SD rats were randomly divided into sham operation group(n=24) and cerebral ischemia reperfusion group(I/R group,n=24).The cerebral ischemia-reperfusion models in I/R group were established by Longa modified suture occlusion in the right middle cerebral artery of the rats.The rats in sham operation group only received blood vessel isolation.TTC staining was used to calculate the ischemic infarction volume of the rats in various groups.qRT-PCR method was used to detect the expression levels of miR-155 in cerebral cortex tissue of the rats in various groups.Results: Compared with sham operation group, the ischemic infarction volume of the rats in I/R group was significantly increased at 24,48,and 72 h after reperfusion(P<0.05);the ischemic infarction volumes of the rats in I/R group were decreased gradually with the prolongation of reperfusion time.Compared with sham operation group,the expression levels of miR-155 in cerebral cortex tissue of the rats in I/R group were significantly increased at 24, 48, and 72 h after reperfusion (P<0.05); the expression levels of miR-155 were gradually decreased with the prolongation of reperfusion time.Conclusion: The expression levels of miR-155 in cerebral cortex tissue of the rats with cerebral ischemia-reperfusion injury are high, and miR-155 may participate in the process of cerebral ischemia-reperfusion injury.