Glutathione content as a potential mediator of the vulnerability of cultured fetal cortical neurons to ethanol-induced apoptosis.
Ethanol ingestion during pregnancy elicits damage to the developing brain, some of which appears to result from enhanced apoptotic death of neurons. A consistent characteristic of this phenomenon is a highly differing sensitivity to ethanol within specific neuron populations. One possible explanation for this "selective vulnerability" could be cellular variations in glutathione (GSH) homeostasis. Prior studies have illustrated that ethanol elicits apoptotic death of neurons in the developing brain, that oxidative stress may be an underlying mechanism, and that GSH can be neuroprotective. In the present study, both multiphoton microscopy and flow cytometry demonstrate a striking heterogeneity in GSH content within cortical neuron populations. Ethanol differentially elicits apoptotic death and oxidative stress in these neurons. When neuron GSH content is reduced by treatment with butathione sulfoxamine, the ethanol-mediated enhancement of reactive oxygen species is exacerbated. Sorting of cells into high- and low-GSH populations further exemplifies ethanol-mediated oxidative stress whereby apoptotic indices are preferentially elevated in the low-GSH population. Western blot analysis of the low-GSH subpopulations shows higher ethanol-mediated expression of active caspase 3 and 24-kDa PARP-1 fragments compared with the high-GSH subpopulation. In addition, neuronal content of 4-hydroxynonenal adducts is higher in low-GSH neurons in response to ethanol. These studies suggest that GSH content is an important predictor of neuronal sensitivity to ethanol-mediated oxidative stress and subsequent cell death. The data support the proposition that the differences in proapoptotic responses to ethanol within specific neuron populations reflect a heterogeneity of neuron GSH content.
Maffi
Shivani Kaushal
SK
Department of Medicine, Division of Infectious Diseases, University of Texas Health Science Center, San Antonio, Texas 78229, USA. maffi@uthscsa.edu
Rathinam
Mary Latha
ML
Cherian
Priscilla P
PP
Pate
William
W
Hamby-Mason
Rhoda
R
Schenker
Steven
S
Henderson
George I
GI
D020268:Alcohol-Induced Disorders, Nervous System / Q000378:metabolism* / Q000503:physiopathology; D000447:Aldehydes / Q000378:metabolism; D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology*; D053148:Caspase 3 / Q000378:metabolism; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000187:drug effects / Q000378:metabolism* / Q000503:physiopathology; D004351:Drug Resistance / Q000502:physiology; D000431:Ethanol / Q000633:toxicity*; D005260:Female; D005434:Flow Cytometry; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects; D005978:Glutathione / Q000378:metabolism*; D009474:Neurons / Q000145:classification / Q000187:drug effects / Q000378:metabolism*; D018384:Oxidative Stress / Q000187:drug effects / Q000502:physiology; D000071137:Poly (ADP-Ribose) Polymerase-1; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism; D011247:Pregnancy; D051381:Rats
D000447:Aldehydes; D000431:Ethanol; C499322:Parp1 protein, rat; D000071137:Poly (ADP-Ribose) Polymerase-1; D011065:Poly(ADP-ribose) Polymerases; D053148:Caspase 3; D005978:Glutathione; C027576:4-hydroxy-2-nonenal