Conclusion
Loss of miR-369 promotes tau phosphorylation by targeting the Fyn and SRPK2 signaling pathways in AD mice, and supplementation with miR-369 might be a valuable option for AD therapeutic studies.
Methods
We generated miR-369 knockout 3xTg-AD mice and investigated their cognitive behaviors by maze tests. Real-time qPCR, western blot, and immunohistochemistry were performed to evaluate the expression of the miR-369 gene, phosphorylation of tau protein, and activation of Fyn and SRPK2. Luciferase reporter assays were applied to confirm the predicted targets of miR-369.
Results
Knocking out miR-369 in 3xTg AD mice aggravated cognitive impairment, promoted hyperphosphorylation of tau, and upregulated Fyn and SRPK2. Restoring miR-369 reversed the hyperphosphorylation of tau and downregulated Fyn and SRPK2. Additionally, miR-369 was shown to target the 3'UTRs of Fyn and SRPK2 to regulate their expression levels.