Fig. 6

Empagliflozin inhibits oxidative stress-induced DNA-PKcs activation. HCAECs were subjected to 45 min of hypoxia followed by two hours of reoxygenation to induce sI/R injury in vitro. The cells were incubated with empagliflozin (EMPA, 10 µM) for 12 h before sI/R injury. A, B ELISAs were used to analyze the kinase activities of DNA-PKcs and Met in HCAECs following sI/R injury or empagliflozin treatment. C–G Western blotting was used to determine DNA-PKcs, Met and p-Fis1 protein levels in HCAECs following sI/R injury or empagliflozin treatment. siRNAs were transfected into HCAECs to knock down DNA-PKcs oe Met. H–J MitoTracker^™ was used to detect changes in mitochondrial dynamics. The number cardiomyocyte with fragmented mitochondria as well as the average length of mitochondria were recorded. K–M To induce oxidative stress, HCAECs were treated with 0.3 mM hydrogen peroxide for six hours to activate DNA-PKcs. NAC (10 mM) was added to the medium in the presence of hydrogen peroxide to reduce oxidative stress-induced DNA-PKcs activation. Then, DNA-PKcs activity was determined with an ELISA. Data are shown as mean ± SEM, n = 10 mice per group or ten independent cell isolations per group. *p < 0.05