Research Paper Volume 12, Issue 19 pp 19045—19059

FGF23 protects osteoblasts from DEX-induced cell death and apoptosis. The differentiated OB-6 human osteoblastic cells (A–D) or the primary murine osteoblasts (G–I) were pretreated with applied concentration of FGF23 (5 or 25 ng/mL) or vehicle control (PBS) for 2h, followed by dexamethasone (DEX, 1 μM) stimulation, cells were further cultured for the indicated time periods, cell viability and cell death were tested by CCK-8 (A and G) or medium LDH release (B and H) assays respectively; expression of the listed apoptosis-associated proteins was shown (C), with cell apoptosis tested by nuclear TUNEL staining (D and I). Stable OB-6 cells with the applied FGFR1 shRNA (“shFGFR1-Seq2”) were pretreated with FGF23 (5 or 25 ng/mL) or PBS for 2h, followed by DEX (1 μM) stimulation, cells were further cultured for 48h, with cell viability (E) and apoptosis (F) tested similarly. Data were mean ± standard deviation (SD, n=5). “Veh” stands for vehicle control for DEX. * p<0.05 vs. “Veh” cells with PBS pretreatment. ^# p<0.05 vs. DEX-treated cells with PBS pretreatment. Each experiment was repeated three times and similar results were obtained. Bar=100 μm (D).