miRNA-126a-3p participates in hippocampal memory via alzheimer's disease-related proteins.

Memory formation and consolidation necessitate gene expression and new protein synthesis. MicroRNAs (miRNAs), a family of small noncoding RNAs that inhibit target gene mRNA expression, are involved in new memory formation. In this study, elevated miR-126a-3p (miR-126) levels were found to contribute to the consolidation of contextual fear memory. Using different commonly mined algorithms and luciferase reporter assay, we found two Alzheimer's disease (AD)-related proteins, namely EFHD2 and BACE1, but not ADAM9, were the targets downregulated by miR-126 after CFC training. Moreover, we indicated that upregulated miR-126 could promote the formation of contextual fear memory by modulating its target EFHD2. Finally, we demonstrated that miR-126 overexpression in dentate gyrus of hippocampus could reduce Aß plaque area and neuroinflammation, as well as rescue the hippocampal memory deficits in APP/PS1 mice. This study adds to the growing body of evidence for the role of miRNAs in memory formation and demonstrates the implication of EFHD2 protein regulated by miR-126 in the adult brain.