Background. miR-132 is a key miRNA consistently downregulated in Alzheimer’s disease (AD) and various tauopathies. MiR-132 overexpression was shown to rescue neurodegenerative phenotypes in AD animal models. However, upregulating miRNAs through miRNA mimics or virus-mediated gene delivery is limited by poor distribution, low uptake, and high immunogenicity. Therefore, we aimed to discover and validate small molecule drugs that upregulate miR-132.
Methods. We performed a pilot high-throughput miRNA-seq screen of ~2000 drugs in human induced pluripotent stem cell (iPSC)-derived neurons. We obtained the expression profiles of ~500 miRNAs for ~1800 drugs and selected compounds associated with the highest miR-132 expression for validation.
Results. We successfully validated that cardiac glycosides, which are canonical sodium-potassium ATPase inhibitors, upregulated miR-132 at the sub-μM range. The mechanism was increased transcription of the miR-132/212 locus and mimicked by knocking down the major ATPase isoforms in neurons. Treating neurons with sub-μM cardiac glycosides potently downregulated total and phosphorylated tau and protected against cell death by N-methyl-D-aspartate (NMDA), rotenone, and Aβ oligomers.
Conclusions. We identified and validated small molecule drugs that upregulated the neuroprotective miR-132 in neurons. Our dataset also represents a comprehensive resource for discovering small molecule drugs that regulate specific miRNAs for therapeutic purposes.