Investigation of vascular endothelial growth factor effects on pulmonary endothelial monolayer permeability and neutrophil transmigration.

Department of Pharmacology, Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Belfield, Dublin 4, Ireland.
General Pharmacology 10/2000; 35(3):149-57. DOI: 10.1016/S0306-3623(01)00102-1
Source: PubMed

ABSTRACT This study sought to determine whether vascular endothelial growth factor (VEGF)-induced permeabilisation of pulmonary endothelium to macromolecules could be related to a permissive role for neutrophil-derived VEGF in neutrophil transmigration. Treatment of human pulmonary artery endothelial cell (HPAEC) monolayers with 1, 10 or 100 ng/ml VEGF for 15 min or 1, 10 ng/ml for 90 min significantly increased endothelial permeability to trypan blue-labelled albumin (TB-BSA). These increases were correlated with changes in the cellular distribution of F-actin, as visualised by rhodamine-phalloidin staining: increased stress fibre formation, cellular elongation and formation of intercellular gaps after 15 min; at 90 min, there was also evidence of microspike formation and extension of spindle processes from the cell surface. Treatment of human neutrophil suspensions with 200 nM phorbol myristyl acetate (PMA), n-formyl-methionyl leucylphenylalanine (fMLP, 10 nM), interleukin-8 (IL-8, 10 nM) (but not with leukotriene B(4) (LTB(4)) 100 nM), for 30 min caused significant extracellular release of neutrophil VEGF stores. A permissive role for neutrophil-derived VEGF in facilitating migration across HPAEC monolayers was assessed in experiments using a functional blocking antihuman VEGF antibody. In the presence of this antibody (10 microg/ml), neutrophil migration in response to fMLP (10 nM), IL-8 (10 nM) or LTB(4) (100 nM) was not significantly different to that in the absence of antibody. We conclude that neutrophil-derived VEGF does not play a functional role in facilitating neutrophil migration across pulmonary vascular endothelium, despite its ability to induce cytoskeletal changes and enhance endothelial macromolecular permeability.

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