VE-cadherin RGD motifs are dispensable for cell-cell junctions, endothelial barrier function and leukocyte extravasation

Abstract

VE-cadherin is a key transmembrane protein in endothelial cell-cell junctions, essential for maintaining vascular integrity and regulating selective leukocyte extravasation into inflamed tissue. The extracellular domain of human VE-cadherin contains two arginine-glycine-aspartate (RGD) motifs, which are known integrin-binding sites, particularly for integrins in the {beta}1, {beta}3, and {beta}5 families. In this study, we examined the functional relevance of these RGD motifs by generating VE-cadherin variants with the RGD sequences mutated to non-functional RGE. Immunofluorescence analysis showed that the VE-cadherin[D238E], VE-cadherin[D301E], and double-mutant VE-cadherin[D238/301E] variants formed stable cell-cell junctions, comparable to wild-type VE-cadherin. Additionally, electric cell-substrate impedance sensing (ECIS) confirmed that endothelial cells expressing each VE-cadherin RGD>RGE variant maintained efficient barrier function. Moreover, leukocyte transmigration assays demonstrated that the RGD>RGE mutations did not affect leukocyte-endothelial interactions during transmigration. In summary, our findings indicate that the VE-cadherin RGD motifs are not essential for endothelial junction formation or leukocyte transmigration.