Impact of single nucleotide polymorphisms in the VEGFR2 gene on endothelial cell activation under non­uniform shear stress.

Single nucleotide polymorphisms (SNPs) in vascular endothelial growth factor receptor 2 (VEGFR2) are associated with coronary artery disease, hypertension and myocardial infarction. However, their association with atherosclerosis remains to be fully elucidated. The purpose of the present study was to determine whether SNPs are involved in atherogenesis, by analyzing their impact on human umbilical vein endothelial cells (HUVECs) under laminar and non­uniform shear stress in a well­established in vitro model that simulates shear stress­induced proatherogenic processes at vessel bifurcations. All experiments were performed using freshly isolated HUVECs. Three SNPs in the VEGFR2 gene (rs1870377 T>A, rs2071559 A>G and rs2305948 C>T) were genotyped and the expression levels of VEGFR2 were semi­quantitatively determined using western blotting. Subsequently, the HUVECs were seeded in bifurcating flow­through cell culture slides and flow (9.6 ml/min) was applied for 19 h, including tumor necrosis factor­α stimulation during the final 2 h of flow. The protein expression levels of VCAM­1, E­selectin and VEGFR2 and the adhesion of THP­1 cells were analyzed in laminar and non­uniform shear stress regions. Data were analyzed for associations with the respective SNPs. The total expression of VEGFR2 was significantly lower under non­uniform shear stress than under laminar shear stress conditions, independent of the genotype. The expression of VEGFR2 between the different shear stress patterns was not significantly altered by the different SNPs. The expression levels of VCAM­1 and E­selectin were lower in the A/A genotype compared with those in other genotypes in rs1870377 T>A and rs2071559 A>G. In conclusion, the results suggested that SNPs within the VEGFR2 gene have a significant impact on shear stress­related endothelial activation.