Figure 4.

Overexpression of SMS2 can lead to ER stress by increasing the deposition of intracellular cholesterol. (A) HUVECs were treated with simvastatin at different doses (0, 0.05, 0.1, 0.2, 0.4, and 0.6 µmol/L) for 24 h, and the level of LDH in the cellular medium was detected. (B) The accumulation of ER cholesterol after filipin staining was visualized under a fluorescence microscope (magnification 40×). (C) The protein levels of GRP78 and CHOP were determined by a western blot analysis. (D) The protein levels of the total ATF6 and cleaved ATF6 were determined by a western blot analysis. n = 3, * p < 0.05, and ** p < 0.001 vs. the C group; ^## p < 0.001 vs. the S group. ^&& p < 0.001 vs. the Sim group. C, cells transfected with empty plasmids treated with H₂O₂ (450 µmol/L) for 24 h; S, cells overexpressing SMS2 treated with H₂O₂ (450 µmol/L) for 24 h; Sim, empty plasmids treated with simvastatin (0.1 µmol/L) for 24 h and then treated with H₂O₂ (450 µmol/L) for 24 h; S+Sim, cells overexpressing SMS2 treated with simvastatin (0.1 µmol/L) for 24 h and then treated with H₂O₂ (450 µmol/L) for 24 h.