title: Induction of endogenous glutathione by the chemoprotective agent, 3H-1,2-dithiole-3-thione, in human neuroblastoma SH-SY5Y cells affords protection against peroxynitrite-induced cytotoxicity.
abstract: Substantial evidence suggests that peroxynitrite generated from the bi-radical reaction of nitric oxide and superoxide is critically involved in the pathogenesis of neurodegenerative disorders, such as Parkinson's disease. Reaction with sulfhydryl (SH)-containing molecules has been proposed to be a major detoxification pathway of peroxynitrite in biological systems. This study was undertaken to determine if chemically elevated intracellular reduced glutathione (GSH), a major SH-containing biomolecule, affords protection against peroxynitrite-mediated toxicity in cultured neuronal cells. Incubation of human neuroblastoma SH-SY5Y cells with the unique chemoprotectant, 3H-1,2-dithiole-3-thione (D3T), led to a significant elevation of cellular GSH in a concentration-dependent fashion. To examine the protective effects of D3T-induced GSH on peroxynitrite-mediated toxicity, SH-SY5Y cells were pretreated with D3T and then exposed to either the peroxynitrite generator, 3-morpholinosydnonimine (SIN-1), or the authentic peroxynitrite. We observed that D3T-pretreated cells showed a markedly increased resistance to SIN-1- or authentic peroxynitrite-induced cytotoxicity, as assessed by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium reduction assay. Conversely, depletion of cellular GSH by buthionine sulfoximine (BSO) caused a marked potentiation of SIN-1- or authentic peroxynitrite-mediated cytotoxicity. To further demonstrate the causal role for GSH induction in D3T-mediated cytoprotection, SH-SY5Y cells were co-treated with BSO to abolish D3T-induced GSH elevation. Co-treatment of the cells with BSO was found to significantly reverse the protective effects of D3T on SIN-1- or authentic peroxynitrite-elicited cytotoxicity. Taken together, this study demonstrates for the first time that D3T can induce GSH in cultured SH-SY5Y cells, and that the D3T-augmented cellular GSH defense affords a marked protection against peroxynitrite-induced toxicity in cultured human neuronal cells.
authors.affiliation: Department of Pharmaceutical Sciences, St. John's University College of Pharmacy and Allied Health Professions, 8000 Utopia Parkway, Jamaica, NY 11439, USA.
authors.forename: Zhuoxiao
authors.initials: Z
authors.lastname: Cao
authors.forename: Seema
authors.initials: S
authors.lastname: Hallur
authors.forename: Harry Z
authors.initials: HZ
authors.lastname: Qiu
authors.forename: Xingxiang
authors.initials: X
authors.lastname: Peng
authors.forename: Yunbo
authors.initials: Y
authors.lastname: Li
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology; D045744:Cell Line, Tumor / Q000187:drug effects / Q000378:metabolism; D002470:Cell Survival / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004351:Drug Resistance / Q000187:drug effects*; D005978:Glutathione / Q000378:metabolism*; D006801:Humans; D009447:Neuroblastoma / Q000378:metabolism*; D030421:Peroxynitrous Acid / Q000378:metabolism* / Q000494:pharmacology; D013871:Thiones / Q000494:pharmacology*; D013876:Thiophenes / Q000494:pharmacology*
chemical_list: D000970:Antineoplastic Agents; D013871:Thiones; D013876:Thiophenes; D030421:Peroxynitrous Acid; D005978:Glutathione; C049325:1,2-dithiol-3-thione