Figure 3. miR-107 inhibition protects osteoblasts from DEX-induced cell death and apoptosis. OB-6 cells (A–D) or primary human osteoblasts (I–J) with pre-miRNA-107 anti-sense lentivirus (antagomiR-107) or control anti-sense lentivirus (antagomiR-C), were treated with DEX (1 μM) or the vehicle control (“Veh”) for indicated time periods, cell viability (CCK-8 OD, A and I), cell death (medium LDH release, B and J), caspase-3 activity (C) and cell apoptosis (nuclear TUNEL staining, D) were tested. The stable OB-6 osteoblastic cells, with the dominant negative AMPKα1 (dn-AMPKα1, T172A) construct, the lentiviral AMPKα1 shRNA (sh-AMPKα1), the CRISPR-Cas-9-AMPKα1 KO plasmid (ko-AMPKα1), as well as the parental control cells (“Pare”) were infected with antagomiR-107 lentivirus for 48h, expression of listed proteins (E) and the relative AMPK activity (F) were tested; Alternatively, cells were treated with DEX (1 μM) or the vehicle control (“Veh”) for another 48h, cell viability (CCK-8 OD, G) and cell death (medium LDH release, H) were tested. Data were mean ± standard deviation (SD, n=5). * p<0.05 vs. “Veh” treatment in “antagomiR-C” cells (A–D, I–J). # p<0.05. vs. “DEX” treatment in “antagomiR-C” cells (A–D, I–J). * p<0.05 vs. “Pare” cells (E–H). Each experiment was repeated three times and similar results were obtained.