Figure 3.

Regulation of eNOS expression in human umbilical vein endothelial cells by SIRT1. (A and B) SIRT1 RNAi effectively knock down endogenous SIRT1 level about 50%. eNOS expression was decreased when SIRT1 was knock down. (C and D) SIRT1 inhibition by NAM decreased eNOS level in dose-dependent manner. Also, Bax protein is upregulated in dose-dependent manner when endothelial cells treated with NAM. (E and F) NAM treatment decreased eNOS level in time-dependent manner. (G and H) SIRT1 inhibition by sirtinol decreased eNOS level in dose-dependent manner. HEK293A cell is used here as negative control. TSA treatment used as positive control. In all western blot experiment, β-actin was used as loading control and each assay was done in triplicate.