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Astrocytes protect neurons from nitric oxide toxicity by a glutathione‐dependent mechanism
Author(s) -
Chen Yongmei,
Vartiainen Nina E.,
Ying Weihai,
Chan Pak H.,
Koistinaho Jari,
Swanson Raymond A.
Publication year - 2001
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1046/j.1471-4159.2001.00374.x
Subject(s) - astrocyte , neurotoxicity , glutamate receptor , glutathione , nitric oxide , toxicity , programmed cell death , buthionine sulfoximine , neurotoxin , chemistry , neuron , microbiology and biotechnology , nmda receptor , neuroglia , biology , biochemistry , biophysics , pharmacology , neuroscience , central nervous system , endocrinology , apoptosis , receptor , organic chemistry , enzyme
Nitric oxide (NO) contributes to neuronal death in cerebral ischemia and other conditions. Astrocytes are anatomically well positioned to shield neurons from NO because astrocyte processes surround most neurons. In this study, the capacity of astrocytes to limit NO neurotoxicity was examined using a cortical co‐culture system. Astrocyte‐coated dialysis membranes were placed directly on top of neuronal cultures to provide a removable astrocyte layer between the neurons and the culture medium. The utility of this system was tested by comparing neuronal death produced by glutamate, which is rapidly cleared by astrocytes, and N ‐methyl‐ d ‐aspartate (NMDA), which is not. The presence of an astrocyte layer increased the LD 50 for glutamate by approximately four‐fold, but had no effect on NMDA toxicity. Astrocyte effects on neuronal death produced by the NO donors S ‐nitroso‐ N ‐acetyl penicillamine and spermine NONOate were examined by placing these compounds into the medium of co‐cultures containing either a control astrocyte layer or an astrocyte layer depleted of glutathione by prior exposure to buthionine sulfoximine. Neurons in culture with the glutathione‐depleted astrocytes exhibited a two‐fold increase in cell death over a range of NO donor concentrations. These findings suggest that astrocytes protect neurons from NO toxicity by a glutathione‐dependent mechanism.