Activation of integrin alpha 5 beta 1 delays apoptosis of Ntera2 neuronal cells

• Published in: Molecular and cellular neuroscience 2005-03, Vol.28 (3), p.588-598
• Main Authors: Gibson, R M, Craig, SE, Heenan, L, Tournier, C, Humphries, MJ
• Format: Article
• Language: English
• ISSN: 1044-7431
• DOI: 10.1016/j.mcn.2004.11.004

Integrins are dynamic membrane proteins that mediate adhesion of cells to the extracellular matrix. Integrins initiate signal transduction, alone and cooperatively with growth factor receptors, and regulate many aspects of cell behavior. We report here that alpha 5 beta 1-mediated adhesion of Ntera2 neuronal cells to fibronectin decreased apoptosis in response to serum withdrawal. Adhesion induced phosphorylation of FAK, and strongly increased the AKT phosphorylation induced by growth factors, demonstrating for the first time in neuronal cells that integrin-mediated adhesion and growth factors cooperate to regulate AKT activity. Integrins exist on cells in different activation states, and cell survival on fibronectin was enhanced by the antibody 12G10, that modulates the conformation of beta 1 in favor of its active form. The antibody 12G10 specifically delayed loss of phosphorylation of AKT on serine 473, and GSK-3 beta on serine 9, induced by serum withdrawal, suggesting that these kinases are critical sensors of integrin activation on neuronal cells.