Abstract
Background. Although inhibition of angiogenesis represents a beneficial approach for the treatment of diseases such as cancer and diabetic retinopathy, knowledge about intrinsic angioinhibitory molecules has been limited. Sphingosine-1-phosphate (S1P) mediates pleiotropic effects in diverse cell types through Edg family G protein-coupled receptors. Interestingly, S1P exerts an inhibitory action on cell migration via Edg-5 receptor subtype. We studied whether S1P/Edg-5 system could inhibit tube formation and migration in vascular endothelial cells. Methods and Results SVEC4-10, a vascular endothelial cell line derived from mouse lymph node, possesses the ability to form tube-like structures on the Matrigel. Northern blot analyses revealed that SVEC4-10 expresses Edg-5 and 3, but not Edg-1. S1P weakly stimulated tube formation and the addition of JTE-013, a specific antagonist against Edg-5, enhanced S1P-induced tube formation. Similarly, JTE-013 potentiated S1P stimulation of cell migration, assessed by a modified Boyden chamber method. In the cells stably overexpressing Edg-5 (SVR-5), S1P markedly inhibited epidermal growth factor (EGF)-induced tube formation and migration in dose-dependent manners and the inhibition was completely reversed by JTE-013. S1P inhibited EGF-induced cellular Rac activation in SVR-5 cells, and JTE-013 cancelled the S1P inhibition. These results suggest that S1P/Edg-5 system plays certain roles in the regulation of tube formation and migration in the cells and might be applicable to angiostatic therapy. [Jpn J Physiol 54 Suppl:S82 (2004)]
