Figure 1.

Regulation of endothelial SIRT1 expression by different stimuli. (A) Detection of SIRT1 expression in human umbilical vein endothelial cells (HUVECs) of third and sixth generation by RT–PCR. (B) Immunoflorescence showed that SIRT1 localizes in the nuclear of HUVECs. The bar indicates 5 µm. (C and D) SIRT1 expression was upregulated by oxLDL treatment in HUVECs. (E and F) SIRT1 expression was upregulated by H₂O₂ treatment in HUVECs. HUVEC was treated with indicated concentration of oxLDL or H₂O₂ for 24 h and protein was harvested for western blot analysis. Each lane represents three times of repeat. (G and H) SIRT1 level was increased in aorta of mice under CR for 1 year. (I and J) SIRT1 level was decreased in aorta of mice fed with high fat diet for 6 months. Full length of aortas were homogenized to extract protein by RIPA buffer for western blot analysis (n = 5). In all western blots, β-actin was used as loading control.