ToxSci Advance Access published online on September 5, 2007
Toxicological Sciences, doi:10.1093/toxsci/kfm236
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Glutathione levels modulate domoic acid-induced apoptosis in mouse cerebellar granule cells

* Department of Environmental and Occupational Health Sciences, University of Washington, 98105, Seattle, WA, USA
Department of Human Anatomy, Pharmacology and Forensic Science, University of Parma Medical School, 43100, Parma, Italy
Address Correspondence: Dr. Lucio G. Costa, Dept. of Environmental and Occupational Health Sciences, University of Washington, 4225 Roosevelt # 100, Seattle, WA 98105, Tel (206) 543-2831, Fax (206) 685-4696, Email: lgcosta{at}u.washington.edu
Received July 19, 2007; revision received August 27, 2007; accepted August 28, 2007
| Abstract |
|---|
Exposure of mouse cerebellar granule neurons (CGNs) to domoic acid induced cell death, either by apoptosis or by necrosis, depending on its concentration. Necrotic damage predominated in response to domoic acid above 0.1 µM. In contrast, cell injury with apoptotic features (assessed by Hoechst staining and DNA laddering assay) was evident after exposure to lower concentrations of domoic acid (
0.1 µM). The AMPA/kainate receptor antagonist NBQX, but not the NMDA receptor antagonist MK-801, prevented domoic acid -induced apoptosis. To evaluate the role of oxidative stress in domoic acid -induced apoptosis, experiments were carried out in CGNs isolated from wild-type mice [Gclm (+/+)], and mice lacking the modifier subunit of glutamate-cysteine ligase, the first and rate limiting step of glutathione (GSH) biosynthesis [Gclm (–/–)]. CGNs from Gclm (–/–) mice have very low levels of GSH, and were more sensitive to domoic acid -induced apoptosis and necrosis than Gclm (+/+) CGNs. The antioxidant melatonin (200 µM), and the membrane permeant GSH delivery agent GSH ethylester (2.5 mM) prevented domoic acid -induced apoptosis. Domoic acid increased formation of reactive oxygen species, but did not affect intracellular GSH levels. Domoic acid also increased cytosolic and mitochondrial calcium levels, increased oxidative stress in mitochondria, and altered mitochondrial membrane potential, which ultimately caused cytochrome c release, activation of caspase-3 and degradation of poly (ADP-ribose) polymerase (PARP). These results indicate that low concentrations of domoic acid cause apoptotic neuronal cell death mediated by oxidative stress.
Key Words: Apoptosis; Domoic acid; Glutamate-cysteine ligase; Glutamate receptors; Glutathione; Oxidative stress.
Email addresses: G. Giordano: gennaro{at}u.washington.edu, C.C. White: ccwhite{at}u.washington.edu, I. Mohar: isaacm{at}u.washington.edu, T.J. Kavanagh: tjkav{at}u.washington.edu, L.G. Costa: lgcosta{at}u.washington.edu
![]()
CiteULike
Connotea
Del.icio.us What's this?
This article has been cited by other articles:
![]() |
A. Vranyac-Tramoundanas, J. C. Harrison, A. N. Clarkson, M. Kapoor, I. C. Winburn, D. S. Kerr, and I. A. Sammut Domoic Acid Impairment of Cardiac Energetics Toxicol. Sci., October 1, 2008; 105(2): 395 - 407. [Abstract] [Full Text] [PDF] |
||||
