S1PR1 knockdown protects endothelial cells from oxidized low-density lipoprotein-induced injury via reducing interleukin-1β and tumor necrosis factor-α expression

Figure 4 Oxidized low-density lipoprotein-induced human umbilical vein endothelial cells injury and sphingosine-1-phosphate receptor 1 expression. A: The viability of human umbilical vein endothelial cells (HUVECs) decreased with the concentration of added oxidized low-density lipoprotein (ox-LDL); B: The apoptosis rate of HUVECs increased with the concentration of added ox-LDL; C: The viability of HUVECs decreased over time after the addition of ox-LDL; D: The apoptosis rate of HUVECs increased over time after the addition of ox-LDL; E: The quantitative real-time polymerase chain reaction results showed that sphingosine-1-phosphate receptor 1 (S1PR1) expression in HUVECs gradually increased with increasing concentrations of ox-LDL after treatment; F: The quantitative real-time polymerase chain reaction results showed that S1PR1 expression in HUVECs gradually increased over time after treatment with ox-LDL; G: The western blot results showed that S1PR1 expression in HUVECs gradually increased with increasing concentrations of ox-LDL after treatment; H: The western blot results showed that S1PR1 expression in HUVECs gradually increased over time after treatment with ox-LDL. ^aP < 0.01 vs 0 μg/mL, ^bP < 0.001 vs 0 μg/mL, ^cP < 0.05 vs 0 μg/mL, ^dP < 0.05 vs 0 hour, ^eP < 0.01 vs 0 hour, ^fP < 0.001 vs 0 hour. S1PR1: Sphingosine-1-phosphate receptor 1.