Effect And Mechanism Of MiRNA-1256 Inhibition On Dexamethasone Induced Osteoblast Injury In Osteoporosis

Objective We here explore the potential effect and mechanism of micro RNA-1256(mi R-1256)on Dexamethasone(Dex)-induced osteoblast cell injury,and study its role in osteoporosis.Methods h FOB1.19 osteoblasts and primary human osteoblasts were cultured.Dexamethasone(1 μ m,48h)intervened the two kinds of cells.Lv-pre-mi R-1256 and lv-antigomi R-1256 lentivirus were used to transfect the two kinds of cells.The m RNA expression levels of mi R-1256 and CAB39 were detected by real-time quantitative polymerase chain reaction;the protein expression levels of mi R-1256 and CAB39 were detected by Western blot;CCK-8 was used to detect cell viability;trypan blue staining was used to detect cell death and apoptosis;RNA pull-down was used to detect the binding of mi R-1256 and CAB39;Promega kit was used to detect the activity of 3’-UTR luciferase of CAB39;automatic fluorescence chemiluminescence analyzer was used to detect reactive oxygen species;one-way ANOVA was used for statistical analysis.Results In h FOB1.19 cells and primary human osteoblasts,CAB39 3’-UTR luciferase activity as well as its expression were downregulated after ectopic mi R-1256 overexpression,but were elevated after mi R-1256 inhibition.In addition,AMPKα1-ACC phosphorylation and AMPK activity were decreased by mi R-1256 overexpression,but augmented with mi R-1256 inhibition.mi R-1256 inhibition increased NADPH activity and m RNA expression of Nrf2 cascade genes,inhibiting Dex-induced oxidative injury and cytotoxicity in h FOB1.19 cells and human osteoblasts.Conclusions CAB39 upregulation after mi R-1256 inhibition activated AMPK signaling to protect human osteoblasts from Dex-induced oxidative injury and inhibit osteoporosis.