Spinal cord homogenates from SOD1 familial amyotrophic lateral sclerosis induce SOD1 aggregation in living cells

• Published in: PloS one Vol. 12; no. 9; p. e0184384
• Main Authors: Pokrishevsky, Edward, Hong, Ran Ha, Mackenzie, Ian R, Cashman, Neil R
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 06.09.2017; Public Library of Science (PLoS)
• Subjects: Agglomeration; Algorithms; Alzheimer's disease; Amyotrophic lateral sclerosis; Amyotrophic Lateral Sclerosis - genetics; Amyotrophic Lateral Sclerosis - metabolism; Animals; Antibodies - chemistry; Atrophy; Biology and Life Sciences; Cells (biology); Complications and side effects; Cytotoxicity; Disease; Disease control; Dosage and administration; Fluorouracil - chemistry; Genes, Reporter; Green Fluorescent Proteins - metabolism; HEK293 Cells; Humans; In vitro methods and tests; Medicine and Health Sciences; Mice; Motor Neurons - metabolism; Mutation; Neurodegeneration; Neurosciences; Physical Sciences; Protein Aggregation, Pathological; Protein Folding; Protein interaction; Proteins; Reporters; Research and Analysis Methods; Rodents; Seeding; Spinal cord; Spinal Cord - metabolism; Superoxide dismutase; Superoxide Dismutase-1 - genetics; Superoxide Dismutase-1 - metabolism; Zinc; Vancouver British Columbia Canada; Canada; United States > US
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0184384

Mutant Cu/Zn superoxide dismutase (SOD1) can confer its misfolding on wild-type SOD1 in living cells; the propagation of misfolding can also be transmitted between cells in vitro. Recent studies identified fluorescently-tagged SOD1G85R as a promiscuous substrate that is highly prone to aggregate by a variety of templates, in vitro and in vivo. Here, we utilized several SOD1-GFP reporter proteins with G37R, G85R, or G93A mutations in SOD1. We observed that human spinal cord homogenates prepared from SOD1 familial ALS (FALS) can induce significantly more intracellular reporter protein aggregation than spinal cord homogenates from sporadic ALS, Alzheimer's disease, multiple system atrophy or healthy control individuals. We also determined that the induction of reporter protein aggregation by SOD1-FALS tissue homogenates can be attenuated by incubating the cells with the SOD1 misfolding-specific antibody 3H1, or the small molecule 5-fluorouridine. Our study further implicates SOD1 as the seeding particle responsible for the spread of SOD1-FALS neurodegeneration from its initial onset site(s), and demonstrates two potential therapeutic strategies for SOD1-mediated disease. This work also comprises a medium-throughput cell-based platform of screening potential therapeutics to attenuate propagated aggregation of SOD1.