The Cellular Prion Protein Increases the Uptake and Toxicity of TDP-43 Fibrils

Viruses. 2021 Aug 17;13(8):1625. doi: 10.3390/v13081625.


Cytoplasmic aggregation of the primarily nuclear TAR DNA-binding protein 43 (TDP-43) affects neurons in most amyotrophic lateral sclerosis (ALS) and approximately half of frontotemporal lobar degeneration (FTLD) cases. The cellular prion protein, PrPC, has been recognized as a common receptor and downstream effector of circulating neurotoxic species of several proteins involved in neurodegeneration. Here, capitalizing on our recently adapted TDP-43 real time quaking induced reaction, we set reproducible protocols to obtain standardized preparations of recombinant TDP-43 fibrils. We then exploited two different cellular systems (human SH-SY5Y and mouse N2a neuroblastoma cells) engineered to express low or high PrPC levels to investigate the link between PrPC expression on the cell surface and the internalization of TDP-43 fibrils. Fibril uptake was increased in cells overexpressing either human or mouse prion protein. Increased internalization was associated with detrimental consequences in all PrP-overexpressing cell lines but was milder in cells expressing the human form of the prion protein. As described for other amyloids, treatment with TDP-43 fibrils induced a reduction in the accumulation of the misfolded form of PrPC, PrPSc, in cells chronically infected with prions. Our results expand the list of misfolded proteins whose uptake and detrimental effects are mediated by PrPC, which encompass almost all pathological amyloids involved in neurodegeneration.

Keywords: PrPC; TDP-43; fibrils; toxicity; uptake.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Biological Transport
  • Cell Line
  • Cell Survival
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism*
  • DNA-Binding Proteins / pharmacology
  • Humans
  • Mice
  • PrPC Proteins / classification
  • PrPC Proteins / genetics*
  • PrPC Proteins / metabolism*
  • Prion Proteins / genetics
  • Prion Proteins / metabolism*


  • DNA-Binding Proteins
  • PrPC Proteins
  • Prion Proteins
  • Prnp protein, mouse
  • TARDBP protein, human
  • TDP-43 protein, mouse