Modeling ALS with iPSCs reveals that mutant SOD1 misregulates neurofilament balance in motor neurons

Cell Stem Cell. 2014 Jun 5;14(6):796-809. doi: 10.1016/j.stem.2014.02.004. Epub 2014 Apr 3.

Abstract

Amyotrophic lateral sclerosis (ALS) presents motoneuron (MN)-selective protein inclusions and axonal degeneration but the underlying mechanisms of such are unknown. Using induced pluripotent cells (iPSCs) from patients with mutation in the Cu/Zn superoxide dismutase (SOD1) gene, we show that spinal MNs, but rarely non-MNs, exhibited neurofilament (NF) aggregation followed by neurite degeneration when glia were not present. These changes were associated with decreased stability of NF-L mRNA and binding of its 3' UTR by mutant SOD1 and thus altered protein proportion of NF subunits. Such MN-selective changes were mimicked by expression of a single copy of the mutant SOD1 in human embryonic stem cells and were prevented by genetic correction of the SOD1 mutation in patient's iPSCs. Importantly, conditional expression of NF-L in the SOD1 iPSC-derived MNs corrected the NF subunit proportion, mitigating NF aggregation and neurite degeneration. Thus, NF misregulation underlies mutant SOD1-mediated NF aggregation and axonal degeneration in ALS MNs.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amyotrophic Lateral Sclerosis / metabolism*
  • Amyotrophic Lateral Sclerosis / pathology
  • Humans
  • Induced Pluripotent Stem Cells / metabolism*
  • Induced Pluripotent Stem Cells / pathology
  • Models, Biological*
  • Motor Neurons / metabolism*
  • Mutant Proteins / genetics
  • Mutant Proteins / metabolism*
  • Mutation
  • Superoxide Dismutase / genetics
  • Superoxide Dismutase / metabolism*
  • Superoxide Dismutase-1

Substances

  • Mutant Proteins
  • SOD1 protein, human
  • Superoxide Dismutase
  • Superoxide Dismutase-1