Resveratrol Inhibits Endothelial Cell Inflammation And Promotes The Molecular Mechanism Of Autophagy Coupling Effect

Chronic inflammation of the blood vessels is the main pathological change in atherosclerosis.However,its pathogenetic mechanismis not completely clear.Ox-LDLis a risk factor for atherosclerosis,which can damage endothelial cells and invovle in the progression of atherosclerosis.Resveratrol is a polyphenolic substance that has various effects such as anti-oxidation and anti-inflammation.This study focused on the effects of resveratrol on TLR activation,MMPs expression and autophagy induced by ox-LDL in endothelial cells,and analyzed the molecular mechanism of resveratrol.inhibiting inflammmation and improving cell function.In this study,human umbilical vein endothelial cells(HUVECs)were used.Endothelial cells were treated with ox-LDL or LPS,and then protein expression and secretion were detected by Western Blot,immunofluorescence and ELISA.Animal experiments were performed to observe the body weight and blood lipid components of mice,and to observe the vascular structure and TLR4 expression by immunohistochemistry.Plasma MMPs were treasured by ELISA.TLR4 is a natural immune receptor.Both external stimulus and accumulation of-endogenous harmful products can induce TLR4 activation and inflammatory response.Metalloproteinases are proteolytic enzymes that are dependent on zinc and calcium ions and have the function of decomposing extracellular matrix.Both are involved in the progression of atherosclerosis.The results showed that ox-LDL or LPS stimulation of endothelial cells increased TLR4,MMP-3,and MMP-9 expression,resveratrol effectively inhibited this reaction.ELSIA results showed that resveratrol reduced the secretion of MMP-3 and MMP-9 in ox-LDL-or LPS-treated endothelial cells.Studies on molecular mechanisms have shown that resveratrol inhibits the phosphorylation of transcription factor of STAT3 in ox-LDL-or LPS-treated endothelial cells.STAT3 inhibitors also inhibit the expression of MMP-3 and MMP-9.The results suggested that STAT3 is the important target of resveratrol.Second,we observed the effect of ox-LDL and resveratrol on Sirtl/AMPK channels.Sirtl is a longevity factor involved.in cellular energy metabolism.The results showed that the expression of Sirtl in endothelial cells was decreased by ox-LDL or LPS,and the phosphorylation level of AMPK was decreased.The resveratrol treatment reversed this phenomenon.The second messenger molecules cAMP and cGMP production are regulated by AMPK,and resveratrol treatment also increases intracellular cAMP and cGMP levels.In addition,we further analyzed the effects of ox-LDL and resveratrol on the autophagy function of cells.Enhanced autophagy is the protective behavior of cells,and mTOR is an upstream molecule of autophagy signaling and has the effect of inhibiting autophagy.The results showed that ox-LDL stimulated endothelial cells to increase mTOR phosphorylation,resveratrol treatment inhibited its phosphorylation,and increased the expression of autophagy marker proteins LC3II,Atg5 and Atg7.Animal experiments were conducted to observe the content of plasma MMP-3,MMP-9,vascular structure and TLR4 expression in mice fed with high-fat diet.The results showed that resveratrol treatment reduced plasma total cholesterol(TC),low-density lipoprotein(LDL),high-density lipoprotein(HDL),and plasma MMP-9 levels compared with the high-fat diet group.There was no significant effect on MMP-3.Sirius staining showed that the mice in the high-fat diet group had disordered vascular structures,reduced collagen composition,and increased interstitial spaces between collagens.The arrangement of vascular collagen in the resveratrol intervention group was similar to that in the normal control group.Immunohistochenical TLR4 staining revealed that TLR4 expression in the vascular wall of mice with high-fat diet was significantly higher than that in the control and resveratrol treatment groups.These results suggest that resveratrol has a protective effect on vascular lesions caused by long-term high-fat diets.Conclusion;Resveratrol can inhibit TLR4-mediated MMP-3 and MMP-9 expression and secretion in ox-LDL-treated endothelial cells,and its molecular mechanism is related to inhibition of transcription factor STAT3 activation Resveratrol can increase Sirtl/AMPK channel activation and increase cellular cAMP and cGMP levels.In addition,resveratrol promotes autophagy and protects endothelial cells from damage induced by ox-LDL.In vivo experiments also showed that resveratrol can reduce the expression of TLR4 in blood vessels of mice with high-fat diet,and reduce the content of plasma MMP-9,which has a protective effect on vascular structural damage.