Sphingosine 1-phosphate promotes endothelial cell barrier integrity by Edg-dependent cytoskeletal rearrangement
Joe G.N. Garcia, … , James R. Bamberg, Denis English
Joe G.N. Garcia, … , James R. Bamberg, Denis English
Published September 1, 2001
Citation Information: J Clin Invest. 2001;108(5):689-701. https://doi.org/10.1172/JCI12450.
View: Text | PDF
Article Article has an altmetric score of 3

Sphingosine 1-phosphate promotes endothelial cell barrier integrity by Edg-dependent cytoskeletal rearrangement

Abstract

Substances released by platelets during blood clotting are essential participants in events that link hemostasis and angiogenesis and ensure adequate wound healing and tissue injury repair. We assessed the participation of sphingosine 1-phosphate (Sph-1-P), a biologically active phosphorylated lipid growth factor released from activated platelets, in the regulation of endothelial monolayer barrier integrity, which is key to both angiogenesis and vascular homeostasis. Sph-1-P produced rapid, sustained, and dose-dependent increases in transmonolayer electrical resistance (TER) across both human and bovine pulmonary artery and lung microvascular endothelial cells. This substance also reversed barrier dysfunction elicited by the edemagenic agent thrombin. Sph-1-P–mediated barrier enhancement was dependent upon Giα-receptor coupling to specific members of the endothelial differentiation gene (Edg) family of receptors (Edg-1 and Edg-3), Rho kinase and tyrosine kinase-dependent activation, and actin filament rearrangement. Sph-1-P–enhanced TER occurred in conjunction with Rac GTPase- and p21-associated kinase–dependent endothelial cortical actin assembly with recruitment of the actin filament regulatory protein, cofilin. Platelet-released Sph-1-P, linked to Rac- and Rho-dependent cytoskeletal rearrangement, may act late in angiogenesis to stabilize newly formed vessels, which often display abnormally increased vascular permeability.

Authors

Joe G.N. Garcia, Feng Liu, Alexander D. Verin, Anna Birukova, Melissa A. Dechert, William T. Gerthoffer, James R. Bamberg, Denis English

×

Figure 10

Options: View larger image (or click on image) Download as PowerPoint
Effect of PAK inhibition on Sph-1-P–induced endothelial cell cytoskeleta...
Effect of PAK inhibition on Sph-1-P–induced endothelial cell cytoskeletal rearrangement. Bovine endothelial cells were transfected with either empty vector (a and b) or dominant negative c-myc-tagged PAK-1 construct (c and d) as described in Methods, followed by challenge with either media (a and c) or 1 μM Sph-1-P (b and d) for 5 minutes. Shown are subsequent merged immunofluorescence images (×100) of endothelial cells stained with Texas red phalloidin for F-actin (red) and anti–c-myc tag Ab for identification of PAK-1 overexpressing cells (green). Overexpression of dominant negative PAK-1 but not empty vector significantly inhibited Sph-1-P–induced actin cortical ring enhancement (F-actin staining in transfected cells after merging green and red images appears as yellow). Arrows point to the increased cortical actin band in the Sph-1-P–treated cells.