miR-161 inhibits ferroptosis by targeting EGLN2 in vascular dementia rat model

Vascular dementia (VD) was characterized by both motor and non-motor dysfunctions and accounts for approximately 20% of dementia patients. Although VD has been given enormous attention owing to its high morbidity and severe consequence, the pathologic mechanisms of VD remain unclear. In this study, the bilateral common carotid artery occlusion (2-VO) rat, which has similar symptoms to VD,was explored the effect of miRNAs and the correlation between ferroptosis and Egl nine homolog 2 (EGLN2) in VD. RT-qPCR showed that miR-161, a new miRNA found in the 2-VO rat, was down-regulated in the frontal lobe, concomitant with increased EGLN2 expression.Western blotting and immunohistochemistry staining results showed, compared with control, the expression of EGLN2 has a significant increase consistently. Target prediction analysis and luciferase-3'‑untranslated region (3’UTR) reporter assay identified the 3’UTR of EGLN2 mRNA to be the direct target of miR-161. Compared with miR-161 treatment, miR-161 inhibition resulted in higher EGLN2 expression. To further explore the role of EGLN2, bioinformatics was used to screen genes. The results showed that glutathione-dependent antioxidant enzyme glutathione peroxidase 4 (GPX4) expression is significantly lower in the brains of VD patients than those in the normal brain. The results of protein interaction analysis showed that GPX4 and EGLN2 could interact with each other. Further experimental results showed, the expression of GPX4 was downgrade in vivo. For PC12 cells, the effect of EGLN2 silencing was consistent with miR-161 decreased GPX4 levels. In conclusion, multiple experimental results elucidated that miR-161 regulates ferroptosis by targeting EGLN2 expression in the frontal lobe which provides a perspective to develop a potential new therapeutic strategy for VD.