MiR-184 expression is regulated by AMPK in pancreatic islets

Abstract

AMPK is a critical energy sensor and target for widely used antidiabetic drugs. In β cells, elevated glucose concentrations lower AMPK activity, and the ablation of both catalytic subunits [β-cell-specific AMPK double-knockout (βAMPKdKO) mice] impairs insulin secretion in vivo and β-cell identity. MicroRNAs (miRNAs) are small RNAs that silence gene expression that are essential for pancreatic β-cell function and identity and altered in diabetes. Here, we have explored the miRNAs acting downstream of AMPK in mouse and human β cells. We identified 14 down-regulated and 9 up-regulated mi RNAs in β AMPKdKO vs. control islets. Gene ontology analysis of targeted transcripts revealed enrichmentinpathways important for β-cell function and identity. The most down-regulated miRNA wasmiR-184 (miR-184-3p), an important regulator of β-cell function and compensatory expansion that is controlled by glucose and reduced in diabetes. We demonstrate that AMPK is a potent regulator and an important mediator of the negative effects of glucose on miR-184 expression. Additionally, we reveal sexual dimorphism in miR-184 expression in mouse and human islets. Collectively, these data demonstrate that glucose-mediated changes in AMPK activity arecentral for there gulation of miR-184 and other miRNAs in is lets and provide a link between energy status and gene expression in β cells.