Fig. 2

OPG protected cardiomyocytes from ROS-induced cell death. (a) Effect of OPG on H₂O₂-induced cell death of H9c2 examined using a cell counting kit. H9c2 cells were treated with 100 μM of H₂O₂ for 24 hours with or without OPG (1.5 and 3 ng/ml) treatment. *p < 0.05, #p < 0.05 compared to H₂O₂-treated group. (b) Expression of proapoptotic receptor TRAIL-R2 and activated (cleaved) caspase 8 in H9c2 cardiomyocytes exposed to H₂O₂ (100 μM) for 24 hours with or without OPG treatment (1.5 and 3 ng/ml) examined by western blot analysis. (c) Effect of ASC conditioned media with or without H₂O₂ conditioning on the viability of H9c2 cardiomyocytes exposed to H₂O₂. Normal conditioned media of ASC (NorCM) prepared by culturing ASCs for 48 hours and conditioned media with H₂O₂ conditioning (H₂O₂CM) prepared by culturing ASCs in the presence of 100 μM of H₂O₂ for 48 hours. H9c2 cells were cultured in NorCM or H₂O₂CM with or without addition of 100 μM of H₂O₂ for 24 hours. *p < 0.05, #p < 0.05 compared to H₂O₂-treated group. (d) Effect of ASC conditioned media with or without H₂O₂ conditioning on the viability of primary cardiomyocytes exposed to H₂O₂. The same experimental procedure used for H9c2 cardiomyocytes was applied to primary cardiomyocytes. *p < 0.05, #p < 0.05 compared to H₂O₂-treated group. OPG osteoprotegerin, TRAIL-R2 tumor necrosis factor-related apoptosis-inducing ligand receptor 2