TUG1 exacerbates cerebral ischemia-reperfusion injury through miR-340-5p-mediated PTEN.

Abstract

Long non-coding RNAs (LncRNAs) play a substantial role in the process of cerebral ischemia-reperfusion injury (CIRI). The present work aimed to determine the probable mechanism by which LncRNA TUG1 exacerbates CIRI via the miR-340-5p/phosphatase and tensin homolog (PTEN) pathway. After developing a middle cerebral artery occlusion/reperfusion (MCAO/R) model, pcDNA-TUG1 together with miR-340-5p agomir were administrated in vivo. Furthermore, the neurologic defects in rats were assessed by a modified neurological severity score. Moreover, 2,3,5-Triphenyl-2H-tetrazolium chloride stain-step was performed to determine the brain's infarct size. In addition, western blotting, immunohistochemistry, and qRT-PCR experiments were utilized for gauging the proteomic/genomic expression-profiles. Luciferase reporter assay validated correlations across TUG1, miR-340-5p, together with PTEN. The results indicated relatively reduced miR-340-5p levels in MCAO/R models, while upregulated TUG1 levels. The pcDNA-TUG1-treated rats indicated increasing neurological dysfunction, whereas the miR-340-5p agomir-treated rats showed improvement. Furthermore, miR-340-5p was determined to be the expected and confirmed TUG1 target. All things considered, the findings suggested that PTEN can serve as the target of miR-340-5p. In addition, TUG1 served as a miR-340-5p ceRNA, which promotes PTEN modulation. Furthermore, TUG1 overexpression decreased miR-340-5p's capacity to fend against CIRI. Conclusively, this work proved that in CIRI, targeting the TUG1/miR-340-5p/PTEN regulatory axis is a viable approach for the treatment of ischemic stroke.