Syndecan ectodomain fragments cause VE-cadherin disorganization and F-actin stress fiber formation.

(A) Representative ECIS traces show Rho kinase inhibitor (Y27632, 10 μM, 1hr pre-treatment) blocks the TER changes induced by rhS3ED and rhS4ED fragments. (B) Immunocytochemistry indicates that, compared to thrombin (0.5 U/ml) alone, rhS3ED fragments and rhS4ED fragments (25 minutes treatment) both mediated significant VE-cadherin disorganization and F-actin stress fiber formation, effects that are inhibited in the presence of Y27632 (10 μM, 1hr pre-treatment). (C) Plot profile analysis of the VE-cadherin and F-actin staining shows that, under vehicle or low concentration thrombin, expression of these two proteins peaks at the intercellular junctions where the barrier remains intact. Following rhS3ED or rhS4ED fragment treatment, the plot profile demonstrates clear VE-cadherin disorganization and strong F-actin fiber stress formation throughout the cells. Furthermore, this analysis highlights the ability of rho kinase inhibitor, Y27632, to prevent the junction disorganization. Scale bar = 10 μm.