The Role Of Resveratrol In The Process Of Atherosclerosis In ApoE-deficient Diabetic Mice And Its Underlying Mechanism

Atherosclerosis is the major pathological risk factor for cardiovascular diseases.Diabetes mellitus is an independent risk factor for cardiovascular diseases and it can accelerate the development and progression of atherosclerosis.It has been thought that high glucose can stimulate oxidative stress and inflammatory reaction,thus resulting in promoting the process of atherosclerosis.However,the precise mechanisms by which diabetes accelerates atherosclerosis remain unclear.Nuclear factor-kappa B(NF-?B)has been shown to be a critical signaling molecule regulating the pathological process of atherosclerosis.Prolyl-isomerase 1(Pinl)plays an important role in the process of vascular injury induced by high glucose via activation of NF-?B p65.Resveratrol(Res)is a non-flavone polyphenol compound found in a variety of plants including grapes and polygonum cuspidatum.Res has been shown to exert a variety of activities including anti-inflammation and antioxidation.There is little study concerning the effect of Res on atherosclerosis in diabetes mellitus and the underlying mechanisms remain unclear.In this study,in vitro cell culture model and in vivo animal model were used to investigate whether Res protects against atherosclerosis and understand whether the underlying mechanisms are related to Pinl/NF-?B signaling pathway mediated oxidative stress and inflammatory reaction.Part 1 Effect of Resveratrol on atherosclerosis in ApoE-deficient diabetic miceAims:To investigate the effect of resveratrolon thoracic aortic atherosclerotic lesions,oxidative stress,inflammatory reaction and Pinl/NF-KB p65 signling pathway in ApoE-deficient diabetic mice.Methods:Streptozotocin(100mg/kg)was used to intraperitoneally inject ApoE-/-mice to generate diabetic model.Diabetic mice were treated with resveratrol(10mg/kg/d)by gavage or Pinlinhibitor(30mg/kg/d)by intraperitoneal injection for 12 weeks(n=10).Assessment of thoracic aortic lesions was performed usingoil red O staining.The levels of Pin1?NADPH gp91 and NF-?B p65 mRNA were analyzed by quantitative PCR(Q-PCR).Protein expression of Pin1?NADPH gp91and NF-?B p65 was detected by western blotting and immunohistochemisty staining.The levels of MDA?SOD and ROS were determined by chemical enzyme assay and assessment of levels of inflammatory cytokines including IL-6?IL-10 and TNFa was performed using ELISA.Results:1)Both resveratrol and Pinl inhibitor treatment reduced thoracic aortic lesion area and improved the function of thoracic aortic contraction and relaxation(P<0.05).2)Both resveratrol and Pinl inhibitor treatment significantly reduced the levels of MDA?ROS?IL-6?IL-10 and TNFa in plasma and thoracic aorta(P<0.05).3)Resveratrol and Pinl inhibitor treatment down-regulatedthe mRNA and protein expression of Pinl?NADPH gp9land NF-?B p65,and increased SOD activity in diabetic mouse thoracic aorta(P<0.05).Conclusion:Resveratrol can attenuate the progression of atherosclerosis in diabetic ApoE-/-mice,possibly through inhibition of oxidative stress and inflammation mediated by Pinl/NF-?B p65 signaling pathway.Part 2 Effect of Resveratrol on ApoE-/-mouse aortic endothelial cell injury induced by high glucose and its underlying mechanismAims:To investigate the effect of resveratrolon oxidative stress and inflammatory reaction in high glucose-treatedApoE-/-mouse aortic endothelial cells and further understand whetherresveratrol inhibits high glucose-induced endothelial cell injury via Pinl/NF-?B p65 signaling pathway.Methods:25 mmol/L of glucose was used to induce injury model of mouse aortic endothelial cells(MAECs).Levels of reactive oxygen species(ROS)were analyzed by flow cytometry.Levels of inflammatory cytokines including IL-6?IL-10 and TNF? in culture medium were measured by ELISA.The mRNA levels and protein expression of Pinl?NADPH gp91and NF-?B p65 were analyzed by quantitative PCR(Q-PCR)and western blotting,respectively.Results:1)Resveratrol?Pinl inhibitor and knock-down of Pin1significantly prevented the increase in the levels of ROS and inflammatory cytokines including IL-6?IL-10 and TNF? in cultured MAECs induced by high glucose,down-regulated the mRNA and protein expression of Pinl?NADPH gp91,and inhibited the nuclear translocation of NF-?B p65(P<0.05).2)Over-expression of Pinl enhanced the levels of ROS?IL-6?IL-10 and Tuna(P<0.05),and stimulated the nuclear translocation of NF-be in MAECs.Additionally,Over-expression of Pinlblocked the effect of resveratrol on the levels of ROS?IL-6?IL-10 and TNFa,and the nuclear translocation of NF-?B in MAECs.Conclusion:Resveratrol can inhibit oxidative stress and inflammation injury in endothelial cells induced by high glucose,possibly via regulation of Pinl/NF-?B p65 signaling pathway.