Effect of dehydroascorbate on reactive oxygen species in mesangial cell induced by high glucose / 中华肾脏病杂志

ABSTRACT

Objective To investigate the effect of dehydroascorbate on reactive oxygen species (ROS) in mesangial cell induced by high glucose. Methods Mesangial cells were cultured in RPMI-1640 medium containing 10% newborn calf serum. Intracellular AA and DHA contents were measured with vitamin C assay system. The intracellular formation of ROS was detected with the fluorescent probe CM-H2DCFDA by using confocal microscopy. Activity of AP-1 was detected by EMSA. Results AA entry into cells was not significantly different from background noise. At a DHA concentration of 1 mmol/L, increasing concentrations of glucose competitively inhibited DHA entry into the cells such that the accumulation of DHA was smaller than half maximal at about 22 mmol/L glucose. Cytochalasin B,a kind of hexose transporter inhibitor,inhibited DHA entry into the cells. At a glucose concentration of 25 mmol/L, DHA inhibited intracellular ROS formation in a dose-dependent manner when DHA level was smaller than 4 mmol/L. In addition, the inhibitory effect of DHA on ROS generation was accompanied by lowering AP-1 activity in mesangial cell incubated by high glucose. Conclusions Mesangial cells are DHA dependent. VitC exclusion from mesangial cells through competition of glucose and DHA for common transport mechanism will deprive the cells of the central antioxidant and can lead to ROS accumulation. Proper doses of DHA will protect mesangial cell from injury of high glucose by inhibition on ROS formation and AP-1 activation.