GSK-3α regulates miRNAs associated with transcriptional and metabolic processes in human cardiomyocytes under hypoxia

Glycogen synthase kinase-3α (GSK-3α) is a multifunctional kinase that plays roles in the pathogenesis of various cardiac diseases, including ischemia and pressure overload and ischemia-reperfusion-induced injury. It regulates key cellular processes such as cardiac cell proliferation, apoptosis, metabolism, and inflammation. However, its role in regulating cardiac microRNAs (miRNAs) remains unknown. To explore the role of GSK-3α in regulating miRNAs, we conducted an unbiased miRNA sequencing analysis in human GSK-3α-overexpressing AC16 cardiomyocytes (GOCs) under hypoxic conditions. Transcriptomic analysis demonstrated numerous differentially expressed miRNAs (DEMs) crucial for transcriptional, inflammatory, and various metabolic processes in the cell. Among 184 DEMs, hsa-miR-3934-5p, hsa-miR-139-5p, and hsa-miR-185-5p were the most up-regulated, while hsa-miR-193b-3p, hsa-miR-181a-2-3p, and hsa-miR-369-3p were the most down-regulated in GOC vs. control cells subjected to hypoxia. Gene ontology (GO) term analysis demonstrated a significant set of genes associated with the terms regulation of transcription, cellular protein modification process, cellular aromatic compound metabolic process, and nucleotide binding in GOC. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis further revealed enrichment of key pathways including metabolic, cytokine-cytokine receptor interaction, cyclic adenosine monophosphate (cAMP), and mitogen-activated protein kinase (MAPK) signaling pathways in GOC challenged with hypoxia. Collectively, these findings reveal a novel mechanism by which GSK-3α regulates a network of miRNAs in human cardiomyocytes required for critical transcriptional, metabolic, and signaling responses including the MAPK and inflammatory pathways under hypoxic stress. GSK-3α-mediated miRNA dysregulation may contribute to the pathophysiological changes observed in ischemia-induced cardiac injury.