Mitochondrial dysfunction due to mutant copper/zinc superoxide dismutase associated with amyotrophic lateral sclerosis is reversed by N-acetylcysteine.
We report that the expression of mutant G93A copper/zinc superoxide dismutase (SOD1), associated with familial amyotrophic lateral sclerosis, specifically causes a decrease in MTT reduction rate and ATP levels and an increase in both cytosolic and mitochondrial reactive oxygen species (ROS) production in human neuroblastoma SH-SY5Y cells compared to cells overexpressing wild-type SOD1 and untransfected cells. Exposure to N-acetylcysteine lowers ROS production and returns mitochondrial functional assays to control levels. No large aggregates of human SOD1 are detectable under basal growth conditions in any of the investigated cell lines. After proteasome activity inhibition, SOD1 aggregates can be detected exclusively in G93A-SOD1 cells, even though they do not per se enhance cell death compared to control cell lines. Our findings indicate that mitochondrial homeostasis is affected by mutant SOD1-generated ROS independently from the formation of aggregates and that this alteration is reversed by antioxidants.
Beretta
Simone
S
Department of Neuroscience and Biomedical Technologies, University of Milano-Bicocca, San Gerardo Hospital, via Donizetti, 106, 20052, Monza (MI), Italy.
Sala
Gessica
G
Mattavelli
Laura
L
Ceresa
Chiara
C
Casciati
Arianna
A
Ferri
Alberto
A
Carrì
Maria Teresa
MT
Ferrarese
Carlo
C
D000111:Acetylcysteine / Q000494:pharmacology*; D000255:Adenosine Triphosphate / Q000032:analysis / Q000378:metabolism; D000690:Amyotrophic Lateral Sclerosis / Q000235:genetics / Q000503:physiopathology*; D015153:Blotting, Western; D053148:Caspase 3; D020169:Caspases / Q000378:metabolism; D016923:Cell Death; D053938:DNA Fragmentation; D005455:Fluorescent Antibody Technique; D016166:Free Radical Scavengers / Q000494:pharmacology*; D006801:Humans; D007770:L-Lactate Dehydrogenase / Q000032:analysis; D008928:Mitochondria / Q000187:drug effects* / Q000201:enzymology / Q000473:pathology; D009154:Mutation; D009447:Neuroblastoma / Q000201:enzymology* / Q000503:physiopathology; D017382:Reactive Oxygen Species / Q000032:analysis / Q000378:metabolism; D013482:Superoxide Dismutase / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism; D013778:Tetrazolium Salts / Q000032:analysis / Q000378:metabolism; D013844:Thiazoles / Q000032:analysis / Q000378:metabolism; D014407:Tumor Cells, Cultured
D016166:Free Radical Scavengers; D017382:Reactive Oxygen Species; D013778:Tetrazolium Salts; D013844:Thiazoles; D000255:Adenosine Triphosphate; D007770:L-Lactate Dehydrogenase; C109415:SOD1 G93A protein; D013482:Superoxide Dismutase; C505407:CASP3 protein, human; D053148:Caspase 3; D020169:Caspases; C022616:thiazolyl blue; D000111:Acetylcysteine