Hepatocyte growth factor enhances endothelial cell barrier function and cortical cytoskeletal rearrangement: potential role of glycogen synthase kinase‐3β

Abstract

ABSTRACT The stabilization of endothelial cell (EC) barrier function within newly formed capillaries is a critical feature of angiogenesis. We examined human lung EC barrier regulation elicited by hepatocyte growth factor (HGF), a recognized angiogenic factor and EC chemoattractant. HGF rapidly and dose‐dependently elevated transendothelial electrical resistance (TER) of EC monolayers (>50% increase at 100 ng/ ml), with immunofluorescence microscopic evidence of both cytoplasmic actin stress fiber dissolution and strong augmentation of the cortical actin ring. HGF rapidly stimulated phosphatidylinositol 3'‐kinase, ERK, p38 mitogen‐activated protein kinase, and protein kinase C activities. Pharmacological inhibitor studies demonstrated each pathway to be intimately involved in HGF‐induced increases in TER, cortical actin thickening, and phosphorylation of the Ser/Thr glycogen synthase kinase‐3p (GSK‐3 P ), a potential target for the HGF barrier‐promoting response. GSK‐3p phosphorylation was strongly correlated with reductions in both HGF‐induced TER and enhanced P ‐catenin immunoreactivity observed at cell‐cell junctions. Our data suggest a model in which HGF‐mediated EC cytoskeletal rearrangement and barrier enhancement depend critically on the activation of a complex kinase cascade that converges at GSK‐3p to increase the availability of P ‐catenin, thereby enhancing endothelial junctional integrity and vascular barrier function.—Liu, F., Schaphorst, K. L., Verin, A. D., Jacobs, K., Birukova, A., Day, R. M., Bogatcheva, N., Bottaro, D. P., Garcia, J. G. N. Hepatocyte growth factor enhances endothelial cell barrier function and cortical cytoskeletal rearrangement: potential role of glycogen synthase kinase‐3. FASEB J. 16, 950–962 (2002)