Figure 2.

Current status of VSMCs senescence regulated by SIRT1. VSMCs senescence can be induced by stressors and doubling passage, characterized by augmented SA-β-gal activity and flattened morphology. Through its downstream molecules, SIRT1 is involved in cell-cycle arrest, abnormal secretory phenotype and DNA damage of VSMCs. The role of SIRT1 in other hallmarks of VSMCs senescence needs further elucidation. AP-1, activator protein-1; Ang II, angiotensin II; H3K9, histone H3 lysine 9; NBS-1, Nijmegen Breakage Syndrome-1; NF-κB, nuclear factor-κB; ROS, reactive oxygen species; VSMC, vascular smooth muscle cell.