Protective Effect Of Zinc On Oxidative Stress In Vascular Endothelial Cells Induced By Uremic Serum And Its Possible Mechanism

Objective To investigate the protective effect of zinc on oxidative stress in vascular endothelial cells induced by uremic serum and its possible mechanism.Methods Serum of uremic patients and healthy controls were collected and the endothelial cells were treated with serum concentration of 15%. The passaged endothelial cells were divided into four groups:normal serum group(N), uremia serum group(U), uremia serum with 10 μmol/L zinc sulfate(U+10), uremia serum with 30 μmol/L zinc sulfate(U+30). DCFH-DA as fluorescence probe was used to detect reactive oxygen species level by fluorescence microplate reader. Total antioxidant capacity was examined by assay kit with a rapid ABTS method. The expression of NQO-1 and HO-1 mRNA was measured by real-time quantitative RT-PCR. The total protein expression of HO-1, NQO-1 and the Nrf-2 was measured by western blot.Results Compared with those in N group, the total antioxidant capacity of endothelial cells in U group was decreased (P＜0.001) and the ROS was significantly increased(P<0.001); while the zinc pretreatment (the U+10 and U+30 two group) increased the total antioxidant capacity of cells and decreased the production of reactive oxygen species(all P<0.001). Both mRNA and protein expressions of HO-1 and NQO-1 were significantly increased in U and zinc pretreatment groups(P<0.05), more prominent in zinc pretreatment group(P<0.05). There was no significant difference between U and N groups in terms of the protein expression of Nrf-2, while the Nrf-2 nucleus expression was significantly increased in zinc pretreatment group compared with the N and U(P<0.001).Conclusion Zinc can improve the total antioxidant capacity and attenuate the oxidative stress induced by uremia serum in endothelial cells through promoting the Nrf-2 nuclear trans locations and increasing the expression of HO-1, NQO-1.