Copper-induced cell death is driven by Impaired protein homeostasis rather than oxidative stress.

SAPORITO MAGRIÑÁ CRISTIAN; MUSACCO SEBIO ROSARIO; ANDRIEUX G, ; BÖRRIES MELANIE; BORNER C; REPETTO MARISA

Buenos Aires

Congreso; LXII Reunión Científica Anual de la Sociedad Argentina de Investigación Clínica.; 2017

Sociedad Argentina de Investigación Clínica.

Wilson Disease is a genetic disorder where copper (Cu) builds upin the organism due to defective metal extrusion from the hepatocytesinto the bile. Intracellular free Cu ions result highly toxic forcells and the metal-induced oxidative stress is assumed to causecell death. Thereby, the major antioxidant glutathione (GSH) hasbeen acknowledged as a protective molecule. Nonetheless, the natureof Cu-induced cell death is unclear and besides the antioxidantfeatures of the molecule, GSH may protect the cell independentlyof the reactive thiol (-SH). Methodology: Cell viability (FACS), ?SHcontent (reaction with DTNB), Cu content (atomic absorption) andDCFH-DA oxidation were assessed after Cu exposure in HCT116,BEAS-2B, HeLa, MEFs and Hepa1-6 cells. Transcriptome profileupon Cu overload in BEAS-2B cells was assessed with DNA microarrays.Protein aggregation was assessed by a turbidity assay.Results: Cu overload enhances intracellular oxidant production.However, no induction of peroxiredoxins, glutathione peroxidasesor catalase was observed in the transcriptome profile and -SH homeostasisin the yet living cells is not altered. Intracellular Cu is accumulatedas Cu1+ either when cells are exposed to Cu1+ or Cu2+.GSH protects cells from Cu ions independently of the reduced ?SHin the molecule, thus preventing the interaction between the metaland intracellular targets. Interestingly, Cu-induced protein aggregationin vitro was fully prevented either by GSH or GSSG, confirmingthat GSH binding of Cu1+ is independent of the reactive ?SH group.