Effect of high glucose on NADPH oxidase expression and reactive oxygen species generation in human umbilical vein endothelial cells

Abstract

To explore the effect of high glucose on NADPH oxidase (NOX) expression and intracellular reactive oxygen species (ROS) generation in human umbilical vein endothelial cells (HUVECs). HUVECs were divided into a control group, a mannite group, a glucose group and a glucose plus diphenylene iodonium (DPI) group. Intracellular ROS was detected by flow cytometry. RNA and protein expression of NOX in HUVECs was analyzed by reverse transcriptase polymerase chain reaction (RT-PCR) and Western blot, respectively. 1) Compared with the control group, the intracellular ROS were significantly increased in the glucose group (P< 0.05, n=3), but there were no significant change in the glucose plus DPI group (P> 0.05, n=3); 2) Compared with the control group, the mRNA and protein expression of NOX4 in the glucose group were significantly increased (P< 0.05), but there were no significant change in the mRNA and protein expression of NOX2, p22phox, p67phox and rac (all P> 0.05); 3) there were no significant difference in the mRNA and protein expression of NOX2, NOX4, p22phox, p67phox and rac between the glucose plus DPI group and the control group (all P> 0.05). High glucose may increases intracellular ROS generation by increasing the expression of NOX4 in HUVECs, which might mediate the oxidative stress.