The Mechanism Of Vascular Endothelial Injury Induced By Hyperhomocysteine And The Effect Of Catalpol Intervention

BackgroundElevated blood homocysteine（Hcy）levels can promote the occurrence and development of atherosclerosis（AS）.Sirtuin1（Sirt1）is widely expressed in nuclear cells of various tissues.It has been reported that the expression of Sirt1 in vascular tissue of AS is decreased,and the activation of Sirt1 can alleviate the occurrence and development of AS.Catalpol is extracted from Radix Rehmanniae and has antioxidant,anti-inflammatory,antitumor and other biological activities.Some studies have shown that catalpol reduces the formation of AS plaques induced by high glucose or high fat,and catalpol is expected to become a new Sirt1 agonist with high oral availability.However,the protective mechanism of catalpol on Hcy-induced AS plaque formation is still unclear.ObjectiveThe human aortic endothelial cell（HAEC）injury model was constructed by using Hcy,and apoptosis,inflammatory response,oxidative stress and the expression of Sirt1 were studied after the intervention with different concentrations of catalpol,so as to clarify the protective effect of catalpol on Hcy-induced endothelial injury and its related mechanism,providing a new theoretical basis for the prevention and treatment of atherosclerosis with Traditional Chinese medicine.Methods1 In vitro culture of human aortic endothelial cells（HAECs）.HAECs were treated with different concentrations of Hcy to establish cell damage model.2 Four groups were set up,which were divided into normal group（Normal）,Hcy treatment group（Hcy 5m M）,low concentration Catalpol treatment group（Hcy+ Catalpol5 u M）and high concentration Catalpol treatment group（Hcy+ Catalpol 10 u M）.3 Cell viability of each group was detected by CCK8 method.Detection of intracellular reactive oxygen species（ROS）by DHE fluorescence probe kit.Western blot was used to detect the expression of Sirt1,acetylated P65（Ac-P65）,Bax and Bcl2 proteins in each group.ResultsCompared with the normal group,HAECs cell viability decreased in a concentrationdependent manner after treated with different concentrations of Hcy for 24 h.In the Hcy group,the ratio of anti-apoptotic protein to apoptotic protein（Bcl-2/Bax）（P<0.01）was significantly decreased,the expression of ROS and P65（P<0.001）protein was significantly increased,and the expression of Sirt1（P<0.01）was decreased.Compared with the Hcy group,cell viability（P<0.0001）,expression of Bcl-2/Bax（P<0.05）and Sirt1（P<0.05）were significantly increased in catalpol treatment group,while intracellular ROS and P65 protein expression（P<0.05）were significantly decreased.ConclusionCatalpol partially alleviates apoptosis,oxidative stress and inflammatory response by activating Sirt1 expression,thus alleviating Hcy-induced endothelial injury.