Background MicroRNAs (miRNAs) are highly expressed in the brain and represent promising therapeutic targets for the treatment of ischemic stroke. Previous studies have shown that microRNA-195 (miR-195) is associated with apoptosis and is significantly upregulated in the serum of patients with ischemic stroke. We aimed to confirm the role of miR-195 in brain microvascular endothelial cell (BMEC) apoptosis and blood–brain barrier (BBB) integrity. Materials and methods bEnd.3 cells were exposed to oxygen–glucose deprivation/reperfusion (OGD/R). RT-qPCR was used to determine the relative expression of miRNA-195. Bioinformatics analysis using the TargetScan database predicted BCL2L2 as a potential target of miR-195. A BBB model was constructed by culturing bEnd.3 cells in the upper Transwell chambers. Transepithelial/transendothelial electrical resistance (TEER) and the fluorescein isothiocyanate (FITC)-dextran assay were used to assess BBB permeability. Immunofluorescence staining for caspase-3, TdT-mediated dUTP nick end labeling (TUNEL) staining, and flow cytometric analysis were used to measure bEnd.3 cell apoptosis. Tight junction proteins (TJPs) expression was determined using western blot analysis. Results miR-195 expression was upregulated in the in vitro OGD/R model. miR-195 mimics exacerbated cellular apoptosis and BBB disruption following OGD/R, whereas the miR-195 inhibitor alleviated OGD/R-induced apoptosis and BBB impairment. Overexpression of miR-195 significantly reduced BCL2L2 expression, and luciferase reporter assays confirmed that miR-195 directly binds to BCL2L2. Co-transfection of miR-195 mimics and BCL2L2 partially reversed the effects of miR-195 mimics on cell survival and barrier function. Conclusion Our results suggest that the miR-195/BCL2L2 axis plays a critical role in the regulation of bEnd.3 cell apoptosis. Modulation of miR-195 may represent a novel therapeutic strategy for targeting BMEC apoptosis in ischemic stroke.
Dong et al. (Tue,) studied this question.