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Updated: Jul 16, 2026
Protein Misfolding Cyclic Amplification of Prions
Published on: November 7, 2012
Prion infection of muscle cells in vitro
Wendy M Dlakic1, Eric Grigg, Richard A Bessen
1Department of Veterinary Molecular Biology, Montana State University, P.O. Box 173610, Bozeman, MT 59717, USA.
Abstract:
The prion agent has been detected in skeletal muscle of humans and animals with prion diseases. Here we report scrapie infection of murine C2C12 myoblasts and myotubes in vitro following coculture with a scrapie-infected murine neuroblastoma (N2A) cell line but not following incubation with a scrapie-infected nonneuronal cell line or a scrapie brain homogenate. Terminal differentiation of scrapie-infected C2C12 myoblasts into myotubes resulted in an increase in the expression of the disease-specific prion protein, PrP(Sc). The amount of scrapie infectivity or PrP(Sc) in C2C12 myotubes was comparable to the levels found in scrapie-infected N2A cells, indicating that a high level of infection was established in muscle cells. Subclones of scrapie-infected C2C12 cells produced high levels of PrP(Sc) in myotubes, and the C-terminal C2 polypeptide fragment of PrP(Sc) was found based on deglycosylation and PrP(Sc)-specific immunoprecipitation of cell lysates. This is the first report of a stable prion infection in muscle cells in vitro and of a long-term prion infection in a nondividing, differentiated peripheral cell type in culture. These in vitro studies also suggest that in vivo prion infection of skeletal muscle requires contact with prion-infected neurons or, possibly, nerve terminals.
Insights
Scrapie prion infection established in mouse muscle cells (C2C12 myoblasts/myotubes) in vitro. This study shows muscle cells can sustain prion protein (PrPSc) infection, suggesting neuron contact may be crucial for in vivo muscle prion disease.
Area of Science:
- Neuroscience
- Cell Biology
- Infectious Diseases
Background:
- Prion diseases, like scrapie, involve the accumulation of abnormal prion protein (PrPSc).
- Prion agents have been detected in skeletal muscle, but in vitro models of muscle infection are limited.
- Understanding prion tropism in non-neuronal tissues is crucial for disease control.
Purpose of the Study:
- To establish and characterize scrapie prion infection in murine skeletal muscle cells (C2C12 myoblasts and myotubes) in vitro.
- To investigate the role of cell differentiation and cell-cell contact in prion infection of muscle cells.
- To determine the level of prion infectivity and PrPSc expression in infected muscle cells.
Main Methods:
- Coculture of murine C2C12 myoblasts with scrapie-infected neuroblastoma (N2A) cells.
- Terminal differentiation of infected myoblasts into myotubes.
- Measurement of prion infectivity and PrPSc levels using specific assays (immunoprecipitation, deglycosylation).
Main Results:
- Scrapie infection was successfully established in C2C12 myoblasts and myotubes via coculture with infected N2A cells.
- Terminal differentiation led to increased PrPSc expression in myotubes.
- Infected myotubes exhibited high levels of scrapie infectivity and PrPSc, comparable to infected N2A cells.
- A C-terminal PrPSc fragment (C2) was identified in infected muscle cells.
Conclusions:
- This is the first report of stable, long-term prion infection in a differentiated, non-dividing peripheral cell type (muscle cells) in vitro.
- In vitro prion infection of skeletal muscle may require direct contact with infected neurons.
- These findings provide a valuable model for studying prion pathogenesis in muscle tissue and suggest potential mechanisms for in vivo muscle prion spread.
