Expression of IGPR-1 in endothelial cells regulates cell survival

Abstract

Angiogenesis is a physiological process by which new blood vessels develop from preexisting vasculature. The process of converting endothelial cells into fully developed blood vessels involves multiple coordinated cellular events that occur through the collaboration that exists between a variety of growth factors, receptors and adhesion molecules. The immunoglobulin-containing and proline rich receptor-1 (IGPR-1) is an IgSF containing adhesion molecule that has been recently identified as a novel regulator of angiogenesis in vitro. In this study, we provide evidence that IGPR-1 promotes cell survival in porcine aortic endothelial cells (PAE) and plays a role in the inhibition of p38 MAPK in vitro. Deletion of the extracellular domain of IGPR-1 abolished IGPR-1’s ability to inhibit phosphorylation of p38 MAPK and promote the survival of endothelial cells. Likewise, mutation of serines 186 (A186-IGPR-1) and 220 (A220-IGPR-1) on the cytoplasmic domain of IGPR-1 was also found to reduce both the promotion of cell survival and inhibition of p38 MAPK. These findings suggest that both domains of IGPR-1 are important for endothelial cell survival and the activation p38 MAPK.