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MicroRNAs (miRNAs) regulate fundamental biological processes by silencing mRNA targets and are dysregulated in many diseases. Therefore, miRNA replacement or inhibition can be harnessed as potential therapeutics. However, existing strategies for miRNA modulation using oligonucleotides and gene therapies are challenging, especially for neurological diseases, and none have yet gained clinical approval. We explore a different approach by screening a biodiverse library of small molecule compounds for their ability to modulate hundreds of miRNAs in human induced pluripotent stem cell-derived neurons. We demonstrate the utility of the screen by identifying cardiac glycosides as potent inducers of miR-132, a key miRNA downregulated in Alzheimer’s disease and other tauopathies. Coordinately, cardiac glycosides downregulate known miR-132 targets, including Tau, and protect rodent and human neurons against various toxic insults. More generally, our dataset of 1370 drug-like compounds and their effects on the miRNome provide a valuable resource for further miRNA-based drug discovery.

SUMMARYMicroRNAs (miRNAs) are short RNAs that regulate fundamental biological processes. miR-132, a key miRNA with established functions in Tau homeostasis and neuroprotection, is consistently downregulated in Alzheimer’s disease (AD) and other tauopathies. miR-132 overexpression rescues neurodegenerative phenotypes in several AD models. To complement research on miRNA-mimicking oligonucleotides targeting the central nervous system, we developed a high-throughput-screen coupled high-throughput-sequencing (HTS-HTS) in human induced pluripotent stem cell (iPSC)-derived neurons to identify small molecule inducers of miR-132. We discovered that cardiac glycosides, which are canonical sodium-potassium ATPase inhibitors, selectively upregulated miR-132 in the sub-μM range. Coordinately, cardiac glycoside treatment downregulated total and phosphorylated Tau in rodent and human neurons and protected against toxicity by glutamate, N-methyl-D-aspartate, rotenone, and Aβ oligomers. In conclusion, we identified small-molecule drugs that upregulated the neuroprotective miR-132 and ameliorated neurodegenerative phenotypes. Our dataset also represents a comprehensive resource for discovering small molecules that modulate specific miRNAs for therapeutic purposes.