title: Tumor necrosis factor (TNF)-mediated neuroprotection against glutamate-induced excitotoxicity is enhanced by N-methyl-D-aspartate receptor activation. Essential role of a TNF receptor 2-mediated phosphatidylinositol 3-kinase-dependent NF-kappa B pathway.
abstract: We have previously shown that two tumor necrosis factor (TNF) receptors (TNFR) exhibit antagonistic functions during neurodegenerative processes in vivo with TNFR1 aggravating and TNFR2 reducing neuronal cell loss, respectively. To elucidate the neuroprotective signaling pathways of TNFR2, we investigated glutamate-induced excitotoxicity in primary cortical neurons. TNF-expressing neurons from TNF-transgenic mice were found to be strongly protected from glutamate-induced apoptosis. Neurons from wild type and TNFR1(-/-) mice prestimulated with TNF or agonistic TNFR2-specific antibodies were also resistant to excitotoxicity, whereas TNFR2(-/-) neurons died upon glutamate and/or TNF exposures. Both protein kinase B/Akt and nuclear factor-kappa B (NF-kappa B) activation were apparent upon TNF treatment. Both TNFR1 and TNFR2 induced the NF-kappa B pathway, yet with distinguishable kinetics and upstream activating components, TNFR1 only induced transient NF-kappa B activation, whereas TNFR2 facilitated long term phosphatidylinositol 3-kinase-dependent NF-kappa B activation strictly. Glutamate-induced triggering of the ionotropic N-methyl-D-aspartate receptor was required for the enhanced and persistent phosphatidylinositol 3-kinase-dependent NF-kappa B activation by TNFR2, indicating a positive cooperation of TNF and neurotransmitter-induced signal pathways. TNFR2-induced persistent NF-kappa B activity was essential for neuronal survival. Thus, the duration of NF-kappa B activation is a critical determinant for sensitivity toward excitotoxic stress and is dependent on a differential upstream signal pathway usage of the two TNFRs.
authors.affiliation: Institute of Cell Biology and Immunology, University of Stuttgart, Allmandring 31, D-70569 Stuttgart, Germany.
authors.forename: Lara
authors.initials: L
authors.lastname: Marchetti
authors.forename: Matthias
authors.initials: M
authors.lastname: Klein
authors.forename: Katalin
authors.initials: K
authors.lastname: Schlett
authors.forename: Klaus
authors.initials: K
authors.lastname: Pfizenmaier
authors.forename: Ulrich L M
authors.initials: UL
authors.lastname: Eisel
mesh_terms: D000818:Animals; D015703:Antigens, CD / Q000378:metabolism*; D017209:Apoptosis; D015152:Blotting, Northern; D015153:Blotting, Western; D001921:Brain / Q000378:metabolism; D016923:Cell Death; D002467:Cell Nucleus / Q000378:metabolism; D002470:Cell Survival; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation; D005971:Glutamates / Q000378:metabolism*; D018698:Glutamic Acid / Q000378:metabolism; D007150:Immunohistochemistry; D007700:Kinetics; D051379:Mice; D008822:Mice, Transgenic; D008957:Models, Genetic; D016328:NF-kappa B / Q000378:metabolism*; D009474:Neurons / Q000378:metabolism; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt; D016194:Receptors, N-Methyl-D-Aspartate / Q000378:metabolism*; D018124:Receptors, Tumor Necrosis Factor / Q000378:metabolism*; D047889:Receptors, Tumor Necrosis Factor, Type II; D015398:Signal Transduction; D013997:Time Factors; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism*
chemical_list: D015703:Antigens, CD; D005971:Glutamates; D018698:Glutamic Acid; D016328:NF-kappa B; D019869:Phosphatidylinositol 3-Kinases; D017346:Protein Serine-Threonine Kinases; D011518:Proto-Oncogene Proteins; D051057:Proto-Oncogene Proteins c-akt; D016194:Receptors, N-Methyl-D-Aspartate; D018124:Receptors, Tumor Necrosis Factor; D047889:Receptors, Tumor Necrosis Factor, Type II; D014409:Tumor Necrosis Factor-alpha