title: Akt as a mediator of cell death.
abstract: Protein kinase B/Akt possesses prosurvival and antiapoptotic activities and is involved in growth factor-mediated neuronal protection. In this study we establish Akt deactivation as a causal mediator of cell death. Akt deactivation occurs in multiple models of cell death including N-methyl-d-aspartate excitotoxicity, vascular stroke, and nitric oxide (NO)- and hydrogen peroxide (H2O2)-elicited death of HeLa, PC12, and Jurkat T cells. Akt deactivation characterizes both caspase-dependent and -independent cell death. Conditions rescuing cell death, such as treatment with poly(ADP-ribose) polymerase or NO synthase inhibitors and preconditioning with sublethal concentrations of N-methyl-d-aspartate, restore Akt activity. Infection of neurons with adenovirus expressing constitutively active Akt prevents excitotoxicity, whereas phosphatidylinositol 3-kinase inhibitors or infection with dominant negative Akt induce death of untreated neuronal cells.
mesh_terms: D000818:Animals; D016923:Cell Death / Q000502:physiology*; D002478:Cells, Cultured; D015536:Down-Regulation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006367:HeLa Cells; D006801:Humans; D016202:N-Methylaspartate / Q000633:toxicity; D016716:PC12 Cells; D000081082:Phosphoinositide-3 Kinase Inhibitors; D017346:Protein Serine-Threonine Kinases; D011518:Proto-Oncogene Proteins / Q000502:physiology*; D051057:Proto-Oncogene Proteins c-akt; D051381:Rats
chemical_list: D004791:Enzyme Inhibitors; D000081082:Phosphoinositide-3 Kinase Inhibitors; D011518:Proto-Oncogene Proteins; D016202:N-Methylaspartate; C494918:AKT1 protein, human; C494920:Akt1 protein, rat; D017346:Protein Serine-Threonine Kinases; D051057:Proto-Oncogene Proteins c-akt