Mechanism Of Venous Fingerprint EphB4 In Regulating Autogenous Vein Graft Adaptation

Objectives:To explore the core regulatory role of EphB4 in the process of vein graft adaptation to arterial blood flow and the regulation mechanism of ERK1/2 pathway.Methods:Transplantation vein animal models with "half expression of EphB4"and "continuous expression of EphB4" were established.The histopathological level was compared with the thickness and stenosis of the anastomotic wall in the vein grafts.Real-time Polymerase Chain Reaction(RT-qPCR)was used to compare differences in EphB4 transcription levels at different time points between groups;The wild type and EphB4+/-(superscript,the same in the text)type rat venous endothelial cells were isolated and cultured.The cells were stimulated by the ligand ephrinB2 of EphB4.The degree of phosphorylation of the two cell membrane receptor EphBR and the degree of phosphorylation of ERK1/2 in the downstream transduction pathway were compared;Cell scratch tests,ERK1/2 conduction pathway blocking experiments,etc.,were performed to compare the similarities and differences between the two cell biological behaviors.Results:One week after venous transplantation,the normal vein,the control group,the ephrinB2 intervention group and the EphB4+/-group were used to extract RNA.The RT-qPCR results showed that there were differences in the expression of EphB4-mRNA and ERK1/2-mRNA(P<0.05);There were significant differences in the thickness of intima+middle membrane,smooth muscle actin(?-actin staining)and collagen fiber(Masson staining)in 4 weeks after intravenous transplantation(P<0.05).Under the same concentration of ephrinB2,the migration degree,the degree of proliferation and the degree of ERK1/2 phosphorylation of EphB4+/--type venous endothelial cells were significantly lower than those of the wild type,and the migration ability of EphB4+/-type venous endothelial cells was further reduced after the use of ERK1/2 blockers(P<0.05).Conclusions:The expression of EphB4 in vein molecular fingerprints may play a key role in the remodeling of graft veins.This process may be regulated by the EphB4-ERK1/2 pathway.EphB4-specific venous VGS may be a new effective target for clinical prevention and treatment of restenosis.