Sphingosine-1-phosphate signaling in endothelial activation.

The signaling and functions of the Endothelial Differentiation Gene (EDG) family of G protein-coupled receptors have been extensively elucidated. All the members of EDG family were shown to be receptors for lysosphingolipids or lysophospholipids. EDG-1, the prototype of EDG family receptors, is a high affinity receptor for serum-borne bioactive lipid, Sphingosine-1-phosphate (S1P). S1P, secreted by thrombotic platelets, has been shown to regulate a variety of cellular responses, including survival, cytoskeletal remodeling, chemotaxis etc, via the activation of cell surface EDG receptors. Recently, a novel function of S1P in modulating angiogenic response has been demonstrated. This review will focus on S1P/ EDG-1 signaling in endothelial activation, in particular in the S1P-mediated adherens junctions assembly and chemotaxis in endothelial cells.