The Migration Of Human Umbilical Vein Endothelial Cells Is Collectively Regulated By S1PR1 And SR-BI Through MEK1/2-ERK1/2 Signaling Pathway

【objective】S1P(sphingosine-1-phosphate)belongs to the class of sphingomyelin in many cells,in plasma free S1 P in plasma is mainly associated with high density lipoprotein(HDL),to induce many functions of HDL.S1 P have five combination in the cell membrane surface membrane receptor S1PR1,S1PR2,S1PR3,S1PR4,S1PR5 to achieve this effect.one of the known natural high affinity receptor of HDL is physiological scavenger receptor class B type I(SR-BI),and SR-B1 induces some biological functions of HDL through a combination of apolipoprotein A-I(apoA-I).There are some researches show that S1P/S1P1 can mediate the migration of human umbilical vein endothelial cells through the MEK1/2-ERK1/2 signaling pathway,and some studies have shown that HDL may be mediated by SR-BI in a variety of biological functions,the molecular mechanisms of these functions may involve the MEK1/2-ERK1/2signal pathway.But the molecular mechanism of HDL/SR-BI mediated migration of HUVECs is rarely reported.Therefore,these are the contents ofthis paper.I hope that the results of this study will help to further understand the HDL of endothelial protection.【Methods】1 HUVECs were cultured in vitro and treated with different concentrations of S1 P.Then,with the appropriate concentration of S1 P,the HUVECs were treated with S1 P for different time,and test the migration of cells by cell scratch test and Transwell at different time points.2 According to the appropriate S1 P concentration and the corresponding processing time on the last steps of the experiment results are processed,then add SEW2871(S1P1 specific agonists)and W146(S1P1 specific inhibitor),cell scratch test and Transwell for cell migration,Western Blot detection of phosphorylated MEK1/2 and ERK1/2 levels.3 Treated with PD98059(MEK specific inhibitor),Western Blot was used to detect the changes of phosphorylated MEK1/2 and phosphorylated ERK1/2 in endothelial cells,and the migration of HUVECs was detected by cell scratch test and Transwell.4 Treated with U0126(ERK specific inhibitor),the changes of phosphorylated MEK1/2 and phosphorylated ERK1/2 were detected by Western blot,and the migration of cells was detected by cell scratch test and Transwell.5 Transfection to expressed SR-BI,Western Blot detection of phosphorylated MEK1/2 and ERK1/2 levels,cell scratch test and Transwell for cell migration;treated with BLT-1(SR-BI inhibitor),and detect the migration and phosphorylated MEK1/2 and ERK1/2 level of HUVECs by the same method.【 Results 】1.S1 P at 1 μmol,24 h had the strongest effect on the migration of HUVECs.2 After activated by SEW2871,p-MEK,p-ERK were increased,cell migration enhanced.3 Treated with MEK specific inhibitor,compared with the control group,levels of p-MEK and p-ERK were reduced,the corresponding,cell migration is weakened.4 The level of ERK decreased after transfection,and the results were similar to that of MEK inhibitor treatment.5 After transfection of SR-BI,phosphorylated ERK and AKT increased,cell migration increased too.But treated with inhibitor of SR-BI,we get the oppsite results.【 Conclusion 】 SR-BI and S1 P can collectively regulate the migration of HUVECs through MEK1/2-ERK1/2 signaling pathway.