Figures & data
Figure 1. Vildagliptin inhibits FFA-induced endothelial lactate dehydrogenase (LDH) release. Human umbilical vein endothelial cells (HUVECs) were treated with high FFAs (1 mM) in the presence or absence of vildagliptin (2.5, 5 μM) for 48 h. LDH release was determined using a commercial kit (a, b, c, p < .01 vs. previous column group).
Figure 2. Vildagliptin suppresses FFA-induced endothelial generation of reactive oxygen species (ROS) and reduction of glutathione (GSH). (A). Intracellular ROS was determined by DCFH-DA; (B). Intracellular GSH levels. Human umbilical vein endothelial cells (HUVECs) were treated with high FFAs (1 mM) in the presence or absence of vildagliptin (2.5, 5 μM) for 48 h (a, b, c, p < .01 vs. previous column group).
Figure 3. Vildagliptin suppresses FFA-mediated endothelial NOX-4 elevation. Human umbilical vein endothelial cells (HUVECs) were treated with high FFAs (1 mM) in the presence or absence of vildagliptin (2.5, 5 μM) for 24 h. (A). mRNA levels of NOX-4 as determined by real-time PCR; (B). Protein levels of NOX-4 determined by western blot analysis (a, b, c, p < .01 vs. previous column group).
Figure 4. Vildagliptin restores FFA-induced reduced endothelial mitochondrial membrane potential (MMP). Human umbilical vein endothelial cells (HUVECs) were treated with high FFAs (1 mM) in the presence or absence of vildagliptin (2.5 μM, 5 μM) for 48 h. MMP levels were determined by TMRM staining (a, b, c, p < .01 vs. previous column group).
Figure 5. Vildagliptin prevents FFA-induced endothelial NLRP3 inflammasome activation. Human umbilical vein endothelial cells (HUVECs) were treated with high FFAs (1 mM) in the presence or absence of vildagliptin (2.5, 5 μM) for 24 h. (A). Western blot analysis of NLRP3, ASC, and cleaved caspase 1 (P20); (B). Quantification of western blot results (a, b, c, p < .01 vs. previous column group).
Figure 6. Vildagliptin inhibits FFA-induced maturation of IL-1β and IL-18. (A). Secretion of IL-1β was assessed by ELISA; (B). Secretion of IL-18 was assessed by ELISA. Human umbilical vein endothelial cells (HUVECs) were treated with high FFAs (1 mM) in the presence or absence of vildagliptin (2.5, 5 μM) for 48 h (a, b, c, p < .01 vs. previous column group).
Figure 7. Vildagliptin inhibits FFA-induced release of high mobility group box-1 protein (HMGB1). Human umbilical vein endothelial cells (HUVECs) were treated with high FFAs (1 mM) in the presence or absence of vildagliptin (2.5 μM, 5 μM) for 48 h. Secretion of HMGB1 was determined by ELISA (a, b, c, p < .01 vs. previous column group).
Figure 8. Vildagliptin mitigates FFA-induced AMPK inactivation. Human umbilical vein endothelial cells (HUVECs) were treated with high FFAs (1 mM) in the presence or absence of vildagliptin (2.5 μM, 5 μM) for 6 h. Phosphorylated and total AMPK was determined by western blot analysis (a, b, c, p<.01 vs. previous column group).
Figure 9. Vildagliptin suppresses FFA-induced reduction of eNOS. Human umbilical vein endothelial cells (HUVECs) were treated with high FFAs (1 mM) in the presence or absence of vildagliptin (2.5 μM, 5 μM) for 24 h. eNOS was determined by Western blot analysis (a, b, c, p < .01 vs. previous column group).
Figure 10. Graphic summary of the underlying mechanisms.
