Regulation Of Angiogenesis By EphB4/ephrinB2 Bidirectional Signaling Pathway In Rats With Arteriovenous Malformations

Objective: By tissue section and endothelial cell culture of the rat model of arteriovenous malformation,the effect of EphB4/EphrinB2 bidirectional signaling pathway on the angiogenesis and the expression of Akt in the cells were studied,which provided a certain direction for the further study of the regulation mechanism of this pathway on angiogenesis.Methods: The rat model of arteriovenous malformation was established by end-to-end anastomosis between the distal end of the left common carotid artery and the proximal end of the external jugular vein in mature male Sprague-Dawley rats.A total of 30 rats were anastomotic.Observing the vascular morphology change,HE staining and Masson staining of the rat vascular tissue sections were conducted to verify that the model is successfully established.EphrinB2,EphB4 and VEGF immunohistochemical staining were done to observe the protein expression and the differences between two groups.Vascular endothelial cells were cultured in vitro by adherent method,and identified by VWF,CD31,VE-cadherin immunofluorescence staining and flow cytometry.EphB4/ EphrinB2 bidirectional signaling pathway was activated and inhibited to observe the regulation of EphB4/ EphrinB2 bidirectional signaling pathway and the change of Akt expression in cells.Results: A total of 30 rats were modeled,and 26 rats were succeeded,with a success rate of 86.7%.In the rat model,the vascular was expanded,comparing with the normal ones,and the pathological changes were observed in the vessels of the positive group,and EphrinB2,EphB4 and VEGF were positive expressed in the positive group.CCK-8 assay showed that the proliferation of cells in the positive group was enhanced by the stimulation of EphrinB2 and EphB4 agonists,while inhibition of the EphB4/EphB2 signaling pathway had no statistically significant effect on the proliferation of cells.q PCR results showed that activating EphB4 decreased Akt expression,activating EphrinB2 increased Akt expression,and inhibiting the EphB4/ EphrinB2 signaling pathway decreased Akt expression in cells.Conclusion: EphrinB2,EphB4,and VEGF were all expressed in the vascular tissues of rats with arteriovenous malformations.EphB4/ephrinB2 bidirectional signaling pathway regulates endothelial cell proliferation.EphB4/ephrinB2 bidirectional signaling pathway regulates angiogenesis in rats with arteriovenous malformation,and PI3K/Akt may be one of it’s signaling pathways.The pathological changes of arteriovenous malformation in rats are similar to those in human brain,which can be used in the basic research of human brain arteriovenous malformation.