title: Activation of integrin alpha5beta1 delays apoptosis of Ntera2 neuronal cells.
abstract: 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 alpha5beta1-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 beta1 in favor of its active form. The antibody 12G10 specifically delayed loss of phosphorylation of AKT on serine 473, and GSK-3beta on serine 9, induced by serum withdrawal, suggesting that these kinases are critical sensors of integrin activation on neuronal cells.
authors.affiliation: Faculty of Life Sciences, University of Manchester, 1.124 Stopford Building, Oxford Road, Manchester, M13 9PT, UK. R.M.Gibson@manchester.ac.uk
authors.forename: Rosemary M
authors.initials: RM
authors.lastname: Gibson
authors.forename: Susan E
authors.initials: SE
authors.lastname: Craig
authors.forename: Laura
authors.initials: L
authors.lastname: Heenan
authors.forename: Cathy
authors.initials: C
authors.lastname: Tournier
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Humphries
mesh_terms: D000906:Antibodies / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology*; D002448:Cell Adhesion / Q000187:drug effects / Q000502:physiology; D045744:Cell Line, Tumor; D002462:Cell Membrane / Q000378:metabolism*; D002470:Cell Survival / Q000187:drug effects / Q000502:physiology; D016895:Culture Media, Serum-Free / Q000494:pharmacology; D005353:Fibronectins / Q000378:metabolism; D051417:Focal Adhesion Kinase 1; D051416:Focal Adhesion Protein-Tyrosine Kinases; D038362:Glycogen Synthase Kinase 3 / Q000187:drug effects / Q000378:metabolism; D000071679:Glycogen Synthase Kinase 3 beta; D006133:Growth Substances / Q000378:metabolism / Q000494:pharmacology; D006801:Humans; D039081:Integrin alpha5beta1 / Q000378:metabolism*; D009474:Neurons / Q000187:drug effects / Q000378:metabolism*; D010766:Phosphorylation / Q000187:drug effects; D011487:Protein Conformation; D017346:Protein Serine-Threonine Kinases / Q000187:drug effects / Q000378:metabolism; D011505:Protein-Tyrosine Kinases / Q000187:drug effects / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000187:drug effects / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt; D012694:Serine / Q000378:metabolism
chemical_list: D000906:Antibodies; D016895:Culture Media, Serum-Free; D005353:Fibronectins; D006133:Growth Substances; D039081:Integrin alpha5beta1; D011518:Proto-Oncogene Proteins; D012694:Serine; D011505:Protein-Tyrosine Kinases; D051417:Focal Adhesion Kinase 1; D051416:Focal Adhesion Protein-Tyrosine Kinases; C496050:PTK2 protein, human; C494918:AKT1 protein, human; C000605506:GSK3B protein, human; D000071679:Glycogen Synthase Kinase 3 beta; D017346:Protein Serine-Threonine Kinases; D051057:Proto-Oncogene Proteins c-akt; D038362:Glycogen Synthase Kinase 3