Study On The Influence Of Sphingomyelinase Synthase 2 On Endothelial Cell Mesenchymal Transformation Through The Wnt/β-catenin Signaling Pathway

Objective:Endothelial dysfunction(ED)is the onset of atherosclerosis(AS),and endothelial mesenchymal transformation(Endo MT),one of the main causes of ED,is considered to be a special form of ED.It is believed that the Wnt/β-catenin signaling pathway can promote the occurrence of ED.The specific recognition of the Wnt ligand and the Frizzled receptor,during signal transmembrane transmission of the Wnt/β-catenin pathway,requires the assistance of phosphorylated coreceptor LRP6,and the phosphorylation modification of coreceptor LRP6 depends on the "lipid rafts".The "lipid raft" is primarily a microspatial structure consisting of sphingomyelins(SM)and cholesterol anchored to each other and related protein molecules,in which the biosynthesis of SM requires the participation of the key enzyme sphingomyelinase synthase 2(SMS2).It is believed that SMS2 can affect the occurrence and development of AS by promoting the release of inflammatory factors in macrophages and the formation of foam cells,while the results of our laboratory have shown that SMS2 can activate the Wnt/β-catenin signaling pathway and promote the occurrence of ED through LRP6,but whether SMS2 can promote Endo MT and enhance ED through the Wnt/β-catenin signaling pathway has not been reported.Mitochondria-dependent fatty acid oxidation(FAO)is the main metabolic pathway of lipid catabolism,involved in endothelial cell Endo MT,proliferation and differentiation.Therefore,based on the existing research results of our laboratory and the corresponding reported references,this paper speculates that SMS2 can inhibit the metabolism of FAO by activating the Wnt/β-catenin pathway,thereby triggering Endo MT and finally promoting ED.To demonstrate this hypothesis,this article investigates the effects on fatty acid oxidative metabolism,Endo MT and ED by interfering with the active expression of SMS2 in endothelial cells and the Wnt/β-catenin signaling pathway.Furthermore,the mechanism of atherosclerosis occurrence and development was elucidated,and new ideas were provided for the clinical treatment of atherosclerosis.Methods:1、ly93 was used to inhibit SMS2 activity to explore its effects on Wnt/β-catenin signaling pathway,fatty acid oxidation,Endo MT and ED.In order to analyze the effects of SMS2 activity inhibition on Wnt/β-catenin signaling pathway,fatty acid oxidation,Endo MT and ED,this paper used ly93 to inhibit SMS2 activity,and divided HUVECs into four experimental groups: C group(0μm),ly93(10μm)group,ly93(20μm)group and ly93(30μm)group,to detect the Wnt/β-catenin signaling pathway,fatty acid oxidation,and changes in the expression and content of Endo MT-related molecules and other ED-related molecules.2、The si RNA technique was used to knock down SMS2 gene expression and then explore the effects on Wnt/β-catenin signaling pathway,fatty acid oxidation,Endo MT and ED.In order to analyze the effects of SMS2 knockdown on Wnt/β-catenin signaling pathway,fatty acid oxidation,Endo MT and ED,this paper used si RNA technology to knock down SMS2 gene expression,and divided HUVECs into three experimental groups: Group C(control),si RNA-1 group and si RNA-2 group,to detect the Wnt/β-catenin signaling pathway,fatty acid oxidation,adhesion ability and changes in the expression and content of Endo MT-related molecules and other ED-related molecules.3、Using the SMS2 lentiviral overexpression vector to change the SMS2 expression of HUVECs,and further explore the effects on Wnt/β-catenin signaling pathway,fatty acid oxidation,Endo MT and ED.In order to analyze the effects of SMS2 overexpression on Wnt/β-catenin signaling pathway,fatty acid oxidation,Endo MT and ED,this paper uses SMS2 lentiviral overexpression vector to infect HUVECs,and divides HUVECs into two experimental groups: C group and Over Express group,to detect the Wnt/β-catenin signaling pathway,fatty acid oxidation,adhesion ability,and Expression and content of Endo MT-related molecules and other ED-related molecules.4、Inhibiting SMS2 activity with ly93 and activating Wnt/β-catenin signaling pathway with SKL2001 to explore the effects on fatty acid oxidative metabolism,Endo MT and ED.In order to analyze whether SMS2 regulates fatty acid oxidative metabolism through the Wnt/β-catenin signaling pathway,thereby affecting Endo MT and ED,this paper uses ly93 to inhibit SMS2 activity while using SKL2001 to activate the Wnt/β-catenin signaling pathway,and divides HUVECs into four groups: C(control),ly93 group,SKL2001 group and ly93+SKL2001 group,to detects the Wnt/β-catenin signaling pathway,fatty acid oxidation,adhesion capacity,expression and content of Endo MT-related molecules and other ED-related molecules.Results:1、 Ly93 can inhibit the activity of SMS2,inhibit Wnt/β-catenin signaling pathway,activate fatty acid oxidation,and alleviate Endo MT and ED.2、 When SMS2 is knocked down,it will inhibit the Wnt/β-catenin pathway and activate the fatty acid oxidative metabolism pathway,alleviating the occurrence of Endo MT and ED.3、 Overexpression of SMS2 can activate Wnt/β-catenin pathway,inhibit fatty acid oxidative metabolic pathway,and promote the occurrence of Endo MT and ED.4、 Inhibition of SMS2 activity can inhibit Wnt/β-catenin signaling pathway and fatty acid oxidative metabolism pathway,and ultimately slow down the occurrence of Endo MT and ED,but activating Wnt/β-catenin signaling pathway can reverse the above process.Conclusions:SMS2 can affect the oxidative metabolic pathway of fatty acids by regulating the Wnt/β-catenin signaling pathway,and ultimately promote the occurrence of Endo MT and ED.