miR-195の発現抑制は、BCL2L2を標的とすることによる酸素-グルコース脱離/再灌流誘発性のBBB破壊を減弱させる
Mingyan Dong1, Lihui Huang1, Qiaohong Zhang1
1National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital and Shenzhen Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Shenzhen, China.
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.
