Astrocytes protect neurons from nitric oxide toxicity by a glutathione-dependent mechanism
Article first published online: 20 DEC 2001
Journal of Neurochemistry
Volume 77, Issue 6, pages 1601–1610, June 2001
How to Cite
Chen, Y., Vartiainen, N. E., Ying, W., Chan, P. H., Koistinaho, J. and Swanson, R. A. (2001), Astrocytes protect neurons from nitric oxide toxicity by a glutathione-dependent mechanism. Journal of Neurochemistry, 77: 1601–1610. doi: 10.1046/j.1471-4159.2001.00374.x
- Issue published online: 20 DEC 2001
- Article first published online: 20 DEC 2001
- Received February 19, 2001; revised manuscript received March 22, 2001; accepted March 23, 2001.
- buthionine sulfoximine;
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 LD50 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.