Abstract
Ligation of the integrin α~v~β~3~ in endothelial cells has been shown to be important for their survival. Such ligation induces signalling events merging into the Raf‐Ras‐ERK cascade that eventually induces activation of nuclear factor kappa B (NFκB), leading to its phosphorylation and nuclear translocation and thus inhibiting apoptosis. Here, the recombinant sixth immunoglobulin‐like domain of cell adhesion molecules L1 (L1Ig6), a ligand for integrin α~v~β~3~, was explored as a component of vascular implant surfaces to initiate the NFκB‐cell survival pathway. This supposition was supported. Specifically, NFκB‐p65 was expressed in human umbilical vein endothelial cells (HUVECs) and when stimulated on L1Ig6, the phosphorylated form was found in the nucleus in over 60% of the cells. NFκB was not translocated into the nucleus on a number of other extracellular matrix substrates examined or when fibroblasts were cultured on L1Ig6. NFκB phosphorylation and nuclear translocation could be inhibited by blocking ligation of α~v~β~3~ by L1Ig6 with an antibody recognizing α~v~β~3~, with a cyclic RGD peptide, and with soluble L1Ig6. Moreover, blocking of α~v~β~3~ interaction with L1Ig6 was correlated with induction of apoptosis. Thus, these experiments demonstrate that L1Ig6 may be useful as α~v~β~3~ ligand for the induction of endothelial survival pathways mediated by NFκB‐p65. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2006