Dopamine D1 receptor activation ameliorates ox-LDL-induced endothelial cell senescence via CREB/Nrf2 pathway.

Endothelial cell senescence is involved in endothelial dysfunction and aging-related vascular diseases. The D1-like dopamine receptor (DR1), a number of G-protein-coupled receptors, is currently under consideration as a potential therapeutic target for the prevention of atherosclerosis. However, the role of DR1 in regulating ox-LDL-stimulated endothelial cell senescence remains unknown. Here, we found that the elevated Prx hyperoxidation and reactive oxygen species (ROS) levels in ox-LDL-treated Human umbilical vein endothelial cells (HUVECs) were observed, suppressed by DR1 agonist SKF38393. Increased proportion of senescence-associated β-galactosidase (SA-β-gal) positive staining cells and activated p16/p21/p53 pathway in ox-LDL-treated HUVECs were significantly abolished by DR1 activation. In addition, SKF38393 increased the phosphorylation of cAMP response element-binding protein (CREB) at serine-133, nuclear accumulation of nuclear factor erythroid 2-related factor 2 (Nrf2) and expression of HO-1 in HUVECs. In contrast, adding H-89, a PKA inhibitor, diminished the effects of DR1 activation. Further studies performed with DR1 siRNA confirmed that DR1 was involved in CREB/Nrf2 pathway. Taken together, DR1 activation reduces ROS production and cell senescence by upregulating CREB/Nrf2 antioxidant signaling in ox-LDL-induced endothelial cells. Thus, DR1 could be a potential molecular target to counteract oxidative stress-induced cellular senescence.