Figure 5. AMPK downstream Nrf2 cascade activation is required for antagomiR-107-induced osteoblast cytoprotection against DEX. Stable OB-6 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, were infected with antagomiR-107 lentivirus for 48h, relative HO1 mRNA expression (vs. “antagomiR-C” cells, A) and NQO1 activity (vs. “antagomiR-C” cells, B) were shown. Stable OB-6 cells, with the CRISPR-Cas-9-Nrf2 KO plasmid (“ko-Nrf2”) or CRISPR-Cas-9-control construct (“Cas9-C”), as well as the parental control cells were infected with antagomiR-107 lentivirus for 48h, expression of listed proteins was shown (C), relative HO1 mRNA expression and NQO1 activity (vs. “antagomiR-C” cells, D) were tested. Alternatively, cells were also treated with DEX (1 μM) or the vehicle control (“Veh”) for another 48h, cell viability (CCK-8 OD, E) and cell death (medium LDH release, F) were tested. Data were mean ± standard deviation (SD, n=5). * p<0.05 vs. “Pare” cells (A, B). # p<0.05 (D–F). Each experiment was repeated three times and similar results were obtained.