ABSTRACT
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.
Subject(s)
Apoptosis/drug effects , Caspases/metabolism , Ferric Compounds/pharmacology , Proto-Oncogene Proteins c-akt/metabolism , Quaternary Ammonium Compounds/pharmacology , Animals , Benzoates/pharmacology , Cells, Cultured , Deferasirox , Down-Regulation , Iron Chelating Agents/pharmacology , Mice , Mitochondria/physiology , Osteoblasts , Phosphorylation , Poly(ADP-ribose) Polymerases/metabolism , Reactive Oxygen Species/metabolism , Signal Transduction/drug effects , Triazoles/pharmacologyABSTRACT
Sodium nitroprusside (NP) alone Was given to the 39 cases with acute high-altitude pulmonary edema (AHPE). 33 of them (84.6%) fully recovered and 6 (15.38%) obviously improved in 72 hours. The total efficacy was 100%. There was obvious improvement in the cardiac pumping and contractile function as well as total peripheral resistance. The mean pulmonary artery pressure (MPAP) decreased from 52.22 +/- 7.51mmHg to 25.13 +/- 10.36mmHg in 3 to 5 hours after the first dose. Strophanthin K was given to another 11 cases with AHPE, But none fully recovered or obviously improved. During the 72 hours of treatment, 4 improved slightly, 4 showed no therapeutic effect and 3 became worse. The heart rate was reduced obviously and cardiac contractile function strengthened while the cardiac pumping function and total peripheral resistance had no change. Vasodilator therapy is a new method for AHPE treatment and this study shows that the NP is an ideal drug in treating AHPE and that dilation of the small pulmonary arteries by NP may explain its efficacy.
