Gentamycin Rationally Repositioned to Inhibit miR-34a Ameliorates Oxidative Injury to PC12 Cells.

Ischemic stroke accompanies oxidative stress and cell death in the cerebral tissue. The microRNA miR-34a plays a pivotal role in this molecular pathology. This study presents the rational repositioning of aminoglycosidic antibiotics as miR-34a antagonists in order to assess their efficiency in protecting the PC12 stroke model cells from oxidative stress occurring under cerebral ischemic conditions. A library of 29 amino-sugar compounds were screened against anticipated structural models of miR-34a through molecular docking. MiR-ligand interactions were mechanistically studied by molecular dynamics simulations and free-energy calculations. Cultured PC12 cells were treated by H 2 O 2 alone or in combination with gentamycin and neomycin as selected drugs. Cell viability and apoptosis were detected by 3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide (MTT) and annexin V-FITC/propidium iodate (PI) double staining assays, respectively. The expression levels of key factors involved in cell proliferation, oxidative stress, and apoptosis in treated PC12 cells were measured through a quantitative real-time polymerase chain reaction and flow cytometric annexin V-FITC/PI double staining assays. A stable and energetically favorable binding was observed for miR-34a with gentamycin and neomycin. Gentamycin pretreatments followed by H 2 O 2 oxidative injury led to increased cell viability and protected PC12 cells against H 2 O 2 -induced apoptotic events. This study will help in further understanding how the suppression of miR-34a in neural tissue affects the cell viability upon stroke.