N‐cadherin adhesion mediated signaling stabilizes VE‐cadherin‐mediated adhesion and strengthens endothelial barrier function (695.3)

N‐cadherin adhesion mediated signaling stabilizes VE‐cadherin‐mediated adhesion and strengthens endothelial barrier function Kevin Kruse, Nathan Sieracki, Yulia Komarova. Neuronal (N)‐cadherin has been shown to be involved in maintaining endothelial barrier function by forming homophilic interaction between endothelial cells (ECs) and pericytes, although it is unknown whether this is solely due to recruitment of pericytes to the endothelium or whether there are signaling events downstream of N‐cadherin homophilic adhesions in ECs that may play a role in strengthening the endothelial barrier. Our research objective therefore is to understand the role of N‐cadherin adhesion mediated signaling in regulating endothelial barrier function. Because N‐cadherin does not form homotypic interactions in an in vitro cell culture monolayer, we have utilized surface chemistry techniques to mimic the N‐cadherin interactions found between ECs and pericytes in vivo. The extracellular domain of N‐cadherin was covalently attached to an Ni‐NTA cover slip, allowing us to study N‐cadherin‐mediated adhesion in ECs. Our data show that ECs grown on N‐cadherin coated surfaces have increased VE‐cadherin accumulation as well as decreased t ½ (half‐time to full fluorescence recovery) of VE‐cadherin turnover at cell‐cell junctions as determined by immunofluorescent staining and fluorescent recovery after photobleaching (FRAP). Our data indicate that N‐cadherin outside‐in signaling promotes formation of VE‐cadherin‐mediated adhesion by possibly stabilizing VE‐cadherin trans ‐interactions. We will further use VE‐ or N‐cadherin biomimetic surfaces to isolate either VE‐cadherin or N‐cadherin complexes in order to understand the common and distinct binding partners and signaling pathways downstream of VE‐ and N‐cadherin. Grant Funding Source : Supported by NIH T32