Overexpression of SIRT1 or suppression of p300 inhibited transient HG-induced senescent “memory” in HUVECs.

Cells were cultured in HG for 3 days followed by 3 days of NG media. SIRT1 plasmid (pSIRT1) or p300 siRNA (si-p300) was transfected into HUVECs twice, 12 hours prior to HG and NG incubation, respectively. After 6 days of culture, cells were harvested for further analysis. Immunoblotting and quantification of p300, SIRT1, p21, Ac-p53, and p53 protein expression after pSIRT1 transfection (A-F) or after 300 siRNA transfection (G-L). For p300, SIRT1, and p21, values were normalized to β-actin; for Ac-p53, normalized to total p53. SIRT1 activity, SA β-Gal positivity, and relative ROS production in HUVECs transfected with pSIRT1 (M-O) or p300 siRNA (P-R). *P < 0.05.