title: Neurotoxicity of "ecstasy" and its metabolites in human dopaminergic differentiated SH-SY5Y cells.
abstract: "Ecstasy" (3,4-methylenedioxymethamphetamine or MDMA) is a widely abused recreational drug, reported to produce neurotoxic effects, both in laboratory animals and in humans. MDMA metabolites can be major contributors for MDMA neurotoxicity. This work studied the neurotoxicity of MDMA and its catechol metabolites, α-methyldopamine (α-MeDA) and N-methyl-α-methyldopamine (N-Me-α-MeDA) in human dopaminergic SH-SY5Y cells differentiated with retinoic acid and 12-O-tetradecanoyl-phorbol-13-acetate. Differentiation led to SH-SY5Y neurons with higher ability to accumulate dopamine and higher resistance towards dopamine neurotoxicity. MDMA catechol metabolites were neurotoxic to SH-SY5Y neurons, leading to caspase 3-independent cell death in a concentration- and time-dependent manner. MDMA did not show a concentration- and time-dependent death. Pre-treatment with the antioxidant and glutathione precursor, N-acetylcysteine (NAC), resulted in strong protection against the MDMA metabolites' neurotoxicity. Neither the superoxide radical scavenger, tiron, nor the inhibitor of the dopamine (DA) transporter, GBR 12909, prevented the metabolites' toxicity. Cells exposed to α-MeDA showed an increase in intracellular glutathione (GSH) levels, which, at the 48 h time-point, was not dependent in the activity increase of γ-glutamylcysteine synthetase (γ-GCS), revealing a possible transient effect. Importantly, pre-treatment with buthionine sulfoximine (BSO), an inhibitor of γ-GCS, prevented α-MeDA induced increase in GSH levels, but did not augment this metabolite cytotoxicity. Even so, BSO pre-treatment abolished NAC protective effects against α-MeDA neurotoxicity, which were, at least partially, due to GSH de novo synthesis. Inversely, pre-treatment of cells with BSO augmented N-Me-α-MeDA-induced neurotoxicity, but only slightly affected NAC neuroprotection. In conclusion, MDMA catechol metabolites promote differential toxic effects to differentiated dopaminergic human SH-SY5Y cells.
authors.affiliation: REQUIMTE (Rede de Química e Tecnologia), Laboratório de Toxicologia, Departamento de Ciências Biológicas, Faculdade de Farmácia, Universidade do Porto, Rua de Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal. patsilvaferreira@hotmail.com
authors.forename: Patrícia Silva
authors.initials: PS
authors.lastname: Ferreira
authors.forename: Tiago Bernandes
authors.initials: TB
authors.lastname: Nogueira
authors.forename: Vera Marisa
authors.initials: VM
authors.lastname: Costa
authors.forename: Paula Sério
authors.initials: PS
authors.lastname: Branco
authors.forename: Luísa Maria
authors.initials: LM
authors.lastname: Ferreira
authors.forename: Eduarda
authors.initials: E
authors.lastname: Fernandes
authors.forename: Maria Lourdes
authors.initials: ML
authors.lastname: Bastos
authors.forename: Andreas
authors.initials: A
authors.lastname: Meisel
authors.forename: Félix
authors.initials: F
authors.lastname: Carvalho
authors.forename: João Paulo
authors.initials: JP
authors.lastname: Capela
mesh_terms: D014013:1,2-Dihydroxybenzene-3,5-Disulfonic Acid Disodium Salt / Q000494:pharmacology; D000111:Acetylcysteine / Q000494:pharmacology*; D019328:Buthionine Sulfoximine / Q000494:pharmacology; D016923:Cell Death / Q000187:drug effects; D002454:Cell Differentiation / Q000187:drug effects; D045744:Cell Line, Tumor; D004151:Dipeptides / Q000378:metabolism; D059290:Dopaminergic Neurons / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D016166:Free Radical Scavengers / Q000494:pharmacology; D005978:Glutathione / Q000378:metabolism; D006801:Humans; D018817:N-Methyl-3,4-methylenedioxyamphetamine / Q000633:toxicity*; D020258:Neurotoxicity Syndromes / Q000209:etiology* / Q000473:pathology; D010879:Piperazines / Q000494:pharmacology
chemical_list: C461261:(1-(2-(bis(4-fluorophenyl)methoxy)ethyl)-4-(3-hydroxy-3-phenylpropyl) piperazinyl decanoate); D004151:Dipeptides; D004791:Enzyme Inhibitors; D016166:Free Radical Scavengers; D010879:Piperazines; D014013:1,2-Dihydroxybenzene-3,5-Disulfonic Acid Disodium Salt; D019328:Buthionine Sulfoximine; D005978:Glutathione; D018817:N-Methyl-3,4-methylenedioxyamphetamine; C017341:gamma-glutamylcysteine; D000111:Acetylcysteine