Iron overload induces apoptosis of murine preosteoblast cells via ROS and inhibition of AKT pathway

Objective This study investigates the inhibitory effect of iron overload on MC3T3‐E1 cells and its molecular mechanism. Methods MC3T3‐E1 cells were grown under different concentrations of FAC (ferric ammonium citrate), and the WST‐8 assay was used to investigate the proliferation of cells following FAC with or without deferasirox. DCFH‐DA fluorescence probe was applied to detect the cellular reactive oxygen species (ROS) level. The apoptotic cells were analyzed with Annexin V‐FITC/PI and the Hoechst 33258 nuclear staining assay. The JC‐1 staining assay was applied to observe the change in the mitochondrial transmembrane potential. The expression levels of caspase‐3, PARP, Bcl‐2 family proteins, and AKT kinase were detected with the Western blot assay. Results Iron overload had a cytotoxic effect on MC3T3‐E1 cells in a dosage‐dependent way and resulted in increasing level of intracellular ROS. Iron overload induced apoptosis in MC3T3‐E1 cells via a caspase‐dependent mechanism that is accompanied by mitochondria dysfunction and decreased expression of anti‐apoptotic proteins. The expression levels of cleaved‐caspase‐3 and cleaved‐PARP were upregulated, while the expression levels of caspase‐9, caspase‐7, caspase‐3, and PARP were downregulated. Phosphorylation of AKT kinase decreased. Conclusion Iron overload can generate ROS in cells, inhibit AKT kinase and its downstream proteins activity, and subsequently initiate apoptotic events.