Excitotoxic Death of Retinal Neurons In Vivo Occurs via a Non-Cell-Autonomous Mechanism

• Published in: The Journal of neuroscience 2009-04, Vol.29 (17), p.5536-5545
• Main Authors: Lebrun-Julien, Frederic, Duplan, Laure, Pernet, Vincent, Osswald, Ingrid, Sapieha, Przemyslaw, Bourgeois, Philippe, Dickson, Kathleen, Bowie, Derek, Barker, Philip A, Di Polo, Adriana
• Format: Article
• Language: English
• Subjects: Animals; Cell Death - drug effects; Cell Death - physiology; Cell Survival - drug effects; Cell Survival - physiology; Excitatory Amino Acid Agonists - toxicity; Mice; Mice, Inbred C57BL; Mice, Knockout; Mice, Transgenic; N-Methylaspartate - toxicity; Retinal Neurons - drug effects; Retinal Neurons - pathology; Retinal Neurons - physiology; Tumor Necrosis Factor-alpha - physiology
• ISSN: 0270-6474; 1529-2401
• DOI: 10.1523/JNEUROSCI.0831-09.2009

The central hypothesis of excitotoxicity is that excessive stimulation of neuronal NMDA-sensitive glutamate receptors is harmful to neurons and contributes to a variety of neurological disorders. Glial cells have been proposed to participate in excitotoxic neuronal loss, but their precise role is defined poorly. In this in vivo study, we show that NMDA induces profound nuclear factor kappaB (NF-kappaB) activation in Müller glia but not in retinal neurons. Intriguingly, NMDA-induced death of retinal neurons is effectively blocked by inhibitors of NF-kappaB activity. We demonstrate that tumor necrosis factor alpha (TNFalpha) protein produced in Müller glial cells via an NMDA-induced NF-kappaB-dependent pathway plays a crucial role in excitotoxic loss of retinal neurons. This cell loss occurs mainly through a TNFalpha-dependent increase in Ca(2+)-permeable AMPA receptors on susceptible neurons. Thus, our data reveal a novel non-cell-autonomous mechanism by which glial cells can profoundly exacerbate neuronal death following excitotoxic injury.