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

Abstract

VE-cadherin is a key transmembrane protein involved in endothelial cell-cell junctions, playing a crucial role in 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 within extracellular matrix proteins, particularly for integrins of the β1, β3, and β5 families. In this study, we examined the functional relevance of these RGD motifs by generating VE-cadherin variants in which the RGD sequences were mutated to nonfunctional RGE. Immunofluorescence analysis showed that the VE-cadherin [D238E], VE-cadherin [D301E], and double-mutant VE-cadherin [D238/301E] variants formed stable endothelial cell-cell junctions that were comparable to junctions based on 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 capacity. Moreover, monocyte transmigration assays demonstrated that the RGD>RGE mutations did not affect monocyte-endothelial interactions during transmigration. In summary, our findings indicate that the VE-cadherin RGD motifs are not essential for endothelial junction formation or monocyte transmigration.