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Updated: Jan 5, 2026
Oxygen-Glucose Deprivation and Reoxygenation as an In Vitro Ischemia-Reperfusion Injury Model for Studying Blood-Brain Barrier Dysfunction
Published on: May 7, 2015
miR-15a regulates oxygen glucose deprivation/reperfusion (OGD/R)-induced neuronal injury by targeting BDNF
Jie-Jie Hu1, Li-Jun Qin2, Zhi-Yan Liu1
1Department of neurology, Lanzhou University Second Hospital, Lanzhou, China.
Abstract:
Multiple microRNAs (miRs) have also been implicated in ischemic brain injury. This research intended to probe the regulatory function and the mechanism of miR-15a on the ischemic brain injury induced by oxygen-glucose deprivation/reoxygenation (OGD/R) in neurons of rats. The OGD/R model was established with the cortical neurons separated from rats. After transfection with miR-15a mimic negative control (NC), miR-15a mimic, miR-15a inhibitor NC and miR-15a inhibitor, the OGD/R-induced apoptosis were detected. Using bioinformatic softwares including TargetScan, miRanda, and miRWalk to predict the underlying targets of miR-15a, and the binding of miR-15a with brain-derived neurotrophic factor (BDNF) were validated with double-fluorescein reporter assay system. The expression levels of BDNF mRNA and protein were detected with qRT-PCR and western blot. The effect of miR-15a on PI3K/AKT pathway in neurons submitted to OGD/R was also investigated. The findings showed that miR-15a may mediate the apoptosis of neurons submitted to OGD/R, and lower expression of Bcl-2 and higher expression of Bax and cleaved caspase-3 were observed. BDNF was screened as the candidate target, and the direct binding of miR-15a with 3'-UTR of BDNF were verified. Further research showed that miR-15a downregulated the expression of BDNF mRNA and protein, thus exerted negative regulatory effect on the OGD/R injury. PI3K/AKT pathway may be related to the regulatory effect of miR-15a. Our findings contribute to uncovering novel pathogenesis for ischemic brain injury.
Insights
MicroRNA-15a (miR-15a) regulates apoptosis in ischemic brain injury by downregulating brain-derived neurotrophic factor (BDNF). This study reveals miR-15a
Area of Science:
- Neuroscience
- Molecular Biology
- Genetics
Background:
- Ischemic brain injury involves complex molecular mechanisms.
- MicroRNAs (miRs) play a role in regulating neuronal apoptosis.
- Oxygen-glucose deprivation/reoxygenation (OGD/R) models are used to study ischemic conditions.
Purpose of the Study:
- To investigate the regulatory role and mechanism of miR-15a in OGD/R-induced ischemic brain injury.
- To identify the molecular targets of miR-15a in neuronal injury.
- To explore the involvement of the PI3K/AKT pathway.
Main Methods:
- Established an OGD/R model using rat cortical neurons.
- Utilized miR-15a mimics and inhibitors for transfection.
- Employed bioinformatics tools (TargetScan, miRanda, miRWalk) for target prediction.
- Validated miR-15a targets using dual-luciferase reporter assays.
- Quantified gene and protein expression via qRT-PCR and Western blot.
- Assessed apoptosis-related proteins (Bcl-2, Bax, cleaved caspase-3) and PI3K/AKT pathway activation.
Main Results:
- miR-15a was found to mediate neuronal apoptosis in OGD/R conditions.
- miR-15a mimics increased apoptosis, while inhibitors reduced it.
- Brain-derived neurotrophic factor (BDNF) was identified as a direct target of miR-15a.
- miR-15a negatively regulated BDNF expression at both mRNA and protein levels.
- The PI3K/AKT signaling pathway was implicated in miR-15a's regulatory effects.
Conclusions:
- miR-15a acts as a negative regulator in OGD/R-induced ischemic brain injury.
- Downregulation of BDNF by miR-15a contributes to neuronal apoptosis.
- The PI3K/AKT pathway is involved in the mechanism of miR-15a action.
- Findings provide insights into the pathogenesis of ischemic brain injury.
