Rutaecarpine Prevents High Glucose-Induced Endothelial Cell Senescence Through Transient Receptor Potential Vanilloid Subtype 1/ SIRT1 Pathway.

ABSTRACT:SIRT1 functions as a longevity factor to counteract vascular aging induced by high glucose. Our previous study revealed that rutaecarpine, the natural agonist of transient receptor potential vanilloid subtype 1 (TRPV1), prevented high glucose-induced endothelial dysfunction. The present study aims to evaluate the effects of rutaecarpine on endothelial cell senescence induced by high glucose, and focus on the regulatory effect on SIRT1 expression. In cultured human umbilical vein endothelial cell (HUVEC), exposure to 33 mM high glucose for 72 hours induced cellular senescence, demonstrated as cell cycle arrest at G0/G1 phase, decreased cell viability, and increased number of senescence-associated β-galactosidase positive senescence cells and ROS production, which were effectively attenuated by treatment with rutaecarpine (0.3, 1, and 3 μM). Furthermore, rutaecarpine upregulated longevity protein SIRT1 expression in HUVECs, accompanied by decreased level of senescence marker p21. In addition, rutaecarpine increased intracellular calcium level in HUVECs, and pretreatment with TRPV1 antagonist capsazepine, intracellular Ca2+ chelator BAPTA-AM or CaM antagonist W-7 abolished the effects of rutaecarpine on SIRT1 expression. In summary, this study shows that rutaecarpine upregulates SIRT1 expression and prevents high glucose-induced endothelial cell senescence, which is related to activation of TRPV1/[Ca2+]i/CaM signal pathway. Our findings provide evidence that rutaecarpine may be a promising candidate with a novel mechanism in prevention vascular aging in diabetes.