Objective To test the oxidative damage and apoptosis in human embryonic kidney cells (HEK293 cells) induced by cadmium.
Methods HEK293 cells were cultured with 0, 30, 60, and 120 μmol/L cadmium chloride (CdCl2) for 1, 3, 6, and 12 h, respectively. Cell growth was tested by MTT assay. The levels of apoptosis and cytosolic reactive oxygen species (ROS) were measured by flow cytometry. Malondialdehyde (MDA) level was detected by thiobarbituric acid method. Glutathione peroxidase (GSH-PX) activity was determined by colorimetric method. Superoxide dismutase (SOD) activity was measured by water-soluble tetrazolium salt method.
Results Cell adhesion was decreased, cells became round, and pseudopodia disappeared following different concentrations of CdCl2 exposure for different exposure time. With the increasing CdCl2 concentrations and exposure time, the growth of cells was inhibited, and the inhibition reached maximum after treatment with 120 μmol/L CdCl2 for 12 h. The apoptosis rates increased with extending exposure time at 30 μmol/L and 60 μmol/L CdCl2 (Ptrend=0.001, Ptrend=0.009). With the increasing of CdCl2 concentrations, the apoptosis rates increased at exposure time of 1, 3, and 6 h, respectively (Ptrend=0.003 or Ptrend=0.001). At the same exposure time, the levels of MDA and ROS increased with higher concentrations of CdCl2 (Ptrend ＜ 0.001 or Ptrend=0.001). The levels of MDA and ROS also increased with exposure time extending at the concentrations of CdCl2 of 30, 60, and 120 μmol/L, respectively (Ptrend ＜ 0.05). Compared with 0 μmol/L CdCl2 group, the activities of SOD and GSH-PX decreased (P＜0.05) in the groups of 30, 60, and 120 μmol/L CdCl2. The activities of SOD and GSH-PX decreased following with the increasing of CdCl2 concentrations (Ptrend ＜ 0.001). The activities of SOD and GSH-PX decreased with longer exposure time at 30, 60, and 120 μmol/L CdCl2, respectively (Ptrend ＜ 0.01).
Conclusion Cadmium can induce oxidative damage and apoptosis in HEK293 cells.
DownLoad: