A mechanism for zinc toxicity in neuroblastoma cells
Date
2004
Authors
Daniels W.M.U.
Hendricks J.
Salie R.
Van Rensburg S.J.
Journal Title
Journal ISSN
Volume Title
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Abstract
Zinc is an important component of proteins essential for normal functioning of the brain. However, it has been shown in vitro that this metal, at elevated levels, can be toxic to cells leading to their death. We investigated possible mechanisms of cell death caused by zinc: firstly, generation of reactive oxygen species, and secondly, the activation of the MAP-kinase pathway. Cell viability was assessed by means of the methyl-thiazolyl tetrazolium salt (MTT) assay and confirmed by tetramethylrhodamine methyl ester (TMRM) staining. We measured the phosphorylation status of Erk and p38 as indicators of MAP-kinase activity, using Western Blot techniques. A time curve was established when neuroblastoma (N2α) cells were exposed to 100 μM of zinc for 4, 12, and 24 h. Zinc caused a significant reduction in cell viability as early as 4 h, and indirectly stimulated the accumulation of reactive oxygen species as determined by 2.7 dichlorodihydrofluorescein diacetate (DCDHF) staining and confocal microscopy. Investigation of the MAP-kinase pathway indicated that Erk was downregulated, while p38 was stimulated. Our results therefore led us to conclude that in vitro, zinc toxicity involved the generation of reactive oxygen species and the activation of the MAP-kinase pathway.
Description
Keywords
ester derivative, fluorescein diacetate, mitogen activated protein kinase, mitogen activated protein kinase p38, reactive oxygen metabolite, rhodamine, tetrazolium, zinc, animal cell, cell death, cell viability, conference paper, confocal microscopy, controlled study, down regulation, enzyme activation, enzyme activity, enzyme phosphorylation, neuroblastoma cell, nonhuman, rat, staining, statistical significance, Western blotting, animal, article, cell survival, cytology, drug effect, human, metabolism, nerve cell, neuroblastoma, phosphorylation, signal transduction, tumor cell line, Animalia, Animals, Cell Line, Tumor, Cell Survival, Humans, MAP Kinase Signaling System, Mitogen-Activated Protein Kinases, Neuroblastoma, Neurons, p38 Mitogen-Activated Protein Kinases, Phosphorylation, Reactive Oxygen Species, Zinc
Citation
Metabolic Brain Disease
19
02-Jan
19
02-Jan