miR-21-3p alleviates neuronal apoptosis during cerebral ischemiareperfusion injury by targeting SMAD2

Abstract

Cerebral ischemia is due to the formation of blood clots or embolisms in the brain arteries, which leads to local brain tissue necrosis and neural cell apoptosis. Recent studies have shown that microRNA (miRNA) plays an important regulatory role in the pathological process of ischemic injury. The aim of this study is to investigate the role and the mechanism of miR-21-3p and drosophila mothers against decapentaplegic 2 (SMAD2) in cerebral ischemic reperfusion injured (CIRI) neural cells. The CIRI model was established by oxygen-glucose deprivation and recovery process for N2a cells. The cell viability and the apoptotic was evaluated by MTT assay and the Flow Cytometer, respectively. The expression of miR-21-3p and SMAD2 mRNA was detected by real-time fluorescence quantitative PCR (qRT-PCR), and the expression of SMAD2 and apoptotic-related proteins were detected by Western Blotting. Our results showed that miR-21-3p is down-regulated, and SMAD2 is up-regulated in CIRI. Overexpression of miR- 21-3p inhibits the apoptosis of neural cells in CIRI. miR-21-3p targets SMAD2 and inhibits SMAD2 expression. Overexpression of SMAD2 eliminates the protective effect of over-expression of miR-21-3p on neural cells in CIRI. Token together, this study provides a theoretical basis for the mechanism of ischemic reperfusion injury in neural cells and a new molecular target for ischemic stroke therapy.