Changes Of MicroRNA-124 Expression In Rat Brains Of Early Ischemia/Reperfusion And Relation With Cell Apoptosis

Objectives This investigation is to reveal the changes of microRNA-124 in rat brains of early cerebral ischemia/reperfusion and the correlation with apoptosis.Methods 54 male Sprague-Dawley rats(8 weeks,SPF grade)were randomly divided into control group,sham group as well as 3,6,12 and 24 h groups.Middle cerebral artery occlusion of rats was established using the Zea-Longa method.Reversed transcription real time q PCR was employed to analyze the changes of microRNA-124 expression in brain tissues.Hematoxylin-eosin staining was used to observe the morphological changes of brain tissues of cerebral ischemia/reperfusion.The expression of Caspase-3 ? Bcl-2 and Bax in brain tissues was analyzed by both immunohistochemical method and Western blot.At the same time,the expression of STAT3 and its active form p-STAT3 was analyzed by Western blot.Results 1 At the early stage of rat cerebral ischemia/reperfusion,the expression of microRNA-124 increased and reached the peak at 12 h after reperfusion.2 Cell apoptosis occurred in brain tissues of early cerebral ischemia/reperfusion.The expression of downstream effective Caspase-3 and upstream pro-apoptotic Bax was upregulated consistently.However,following the increasing trend,the expression of upstream antiapoptotic Bcl-2 and the ratio of Bcl-2/Bax present dynamic changes amd reached the maximum point at 12 h after reperfusion.3 p-STAT3,the phosphorylated form of STAT3,was upregulated in brain tissues of early cerebral ischemia/reperfusion and changed dynamically.The expression of p-STAT3 reached the peak at 12 h after reperfusion.Accordingly,the expression of STAT3 was downregulated and showed the lowest point at 12 h after reperfusion.Conclusions At the early stage of rat cerebral ischemia/reperfusion,the dynamic expression of microRNA-124 in brain tissues is positively correlated with the expression of Bcl-2 and STAT3.And they presented similar trends of changes as response to cerebral ischemia/reperfusion,which indicated there is correlation between microRNA-124 and cerebral ischemia/reperfusion injury,and both Bcl-2 and STAT3 were involved in the protective effect of microRNA-124.