Manganese-Induced Neurotoxicity is Differentially Enhanced by Glutathione Depletion in Astrocytoma and Neuroblastoma Cells
- 199 Downloads
Manganese (Mn) is neurotoxic: the underlying mechanisms have not been fully elucidated. l-Buthionine-(S,R)-sulfoximine (BSO) is an irreversible inhibitor of γ-glutamylcysteine synthetase, an important enzyme in glutathione (GSH) synthesis. To test the hypothesis that BSO modulates Mn toxicity, we investigated the effects of treatment of U-87 or SK-N-SH cells with MnCl2, BSO, or MnCl2 plus BSO. We monitored cell viability using MTT assay, staining with HO-33342 to assess live and/or apoptotic cells, and staining with propidium iodide (PI) to assess necrotic cells; we also measured cellular glutathione. Our results indicate decreased viability in both cell types when treated with MnCl2 or BSO: Mn was more toxic to SK-N-SH cells, whereas BSO was more toxic to U-87 cells. Because BSO treatment accentuated Mn toxicity in both cell lines, GSH may act to combat Mn toxicity. Thus, further investigation in oxidative stress mediated by glutathione depletion will unravel new Mn toxicity mechanism(s).
KeywordsManganese Oxidative stress Glutathione Mn neurotoxicity Glutathione depletion BSO Astrocytoma and neuroblastoma cells
This study was supported by a grant from Idaho Biomedical Research Infrastructure Network (NIH NCRR BRINIP20RR016454) and an Idaho State University FRC grant. The authors thank Isaac Alfred Orina for his helpful suggestions. V.V. Dukhande thanks the Idaho INBRE NIH program (grant # P20RR016454) for a research fellowship.
- 1.Lai JCK, Chan AWK, Minski MJ, Lim L (1985) Roles of metal ions in brain development and aging. In: Gabay S, Harris J, Ho BT (eds) Metal ions in neurology and psychiatry. Alan Liss, New York, pp 49–67Google Scholar
- 5.Lai JCK, Minski MJ, Chan AWK, Lim L (2000) Interrelations between manganese and other metal ions in health and disease. In: Sigel A, Sigel H (eds) Metal ions in biological systems. Dekker, New York, pp 123–156Google Scholar
- 6.Lai JCK, Chan AWK, Minski MJ, Leung TKC, Lim L, Davison AN (1985) Application of instrumental neutron activation analysis to the study of trace metals in brain and metal toxicity. In: Gabay S, Harris J, Ho BT (eds) Metal ions in neurology and psychiatry, Alan Liss, New York, pp 323–343Google Scholar
- 20.Malthankar GV, White BK, Bhushan A, Daniels CK, Rodnick KJ, Lai JCK (2004) Differential lowering by manganese treatment of activities of glycolytic and tricarboxylic acid (TCA) cycle enzymes investigated in neuroblastoma and astrocytoma cells is associated with manganese-induced cell death. Neurochem Res 29:709–717PubMedCrossRefGoogle Scholar
- 21.Lai JCK, Leung TKC, Lim L (1984) Differences in the neurotoxic effects of manganese during development and aging: some observations on brain regional neurotransmitter and non-neurotransmitter metabolism in a developmental rat model of chronic manganese encephalopathy. Neurotoxicology 5:37–47PubMedGoogle Scholar
- 26.Makar TK, Nedergaard M, Preuss A, Gelbard AS, Perumal AS, Cooper AJL (1994) Vitamin E, ascorbate, glutathione, glutathione disulfide, and enzymes of glutathione metabolism in cultures of chick astrocytes and neurons: evidence that astrocytes play an important role in antioxidative processes in the brain. J Neurochem 62:45–53PubMedCrossRefGoogle Scholar
- 36.Lai JCK, Leung TKC, Lim L (1985) Effects of metal ions on neurotransmitter function and metabolism. In: Gabay S, Harris J, Ho BT (eds) Metal ions in neurology and psychiatry. Alan Liss, New York, pp 177–197Google Scholar
- 37.Jain A, Martensson J, Stole E, Auld PA, Meister A (1991) Glutathione deficiency leads to mitochondrial damage in brain PNAS 88:1913–1917Google Scholar