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 ischemiareperfusion 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.

In recent years, the incidence of stroke increased year by year and the research on post-stroke epilepsy (PSD) is also increasing.In addition to the type, location, and severity of stroke, the occurrence of PSD is also associated with small vessel disease and genetic factors;however, the exact pathophysiological mechanisms are not very clear.This article reviews the risk factors and pathophysiological mechanisms of PSD.

Post-stroke epilepsy (PSE),as one of the common complications after stroke,often seriously affect the quality of life of the survivors.In recent years,more and more studies have found that statins can protect the integrity of blood-brain barrier,alleviate excitotoxic damage of neurotransmitters,reduce neuronal apoptosis,and reduce neuroinflammation,which play a role in brain protection,thereby reducing the risk of PSE.This article reviews the treatment of PSE and application of statins in PSE.

MicroRNA is a class of short-chain non-coding RNA that regulates gene expression at post-transcriptional level.It can participate in the pathophysiology processes of tumor regulation,neurodegenerative disease,and cardiovascular disease.Recent studies have shown that microRNA can play a reguhtory role in ischemic brain damage through autophagy.This article reviews the effect of microRNA on autophagy after cerebral ischamia and its possible mechanisms.