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Updated: Jul 10, 2026
Modeling Myotonic Dystrophy 1 in C2C12 Myoblast Cells
Published on: July 29, 2016
Phenotypic behavior of C2C12 myoblasts upon expression of the dystrophy-related caveolin-3 P104L and TFT mutants
Alessandro Fanzani1, Elena Stoppani, Laura Gualandi
1Department of Biomedical Sciences and Biotechnology, Unit of Biochemistry, University of Brescia, Viale Europa 11, 25123 Brescia, Italy. fanzani@med.unibs.it
Abstract:
Caveolin-3 (Cav-3) is the main scaffolding protein present in myofiber caveolae. We transfected C2C12 myoblasts with dominant negative forms of Cav-3, P104L or DeltaTFT, respectively, which cause the limb-girdle muscular dystrophy 1-C. Both these forms triggered Cav-3 loss during C2C12 cell differentiation. The P104L mutation reduced myofiber formation by impaired AKT signalling, accompanied by dramatic expression of the E3 ubiquitin ligase Atrogin. On the other hand, the DeltaTFT mutation triggered hypertrophic myotubes sustained by prolonged AKT activation, but independent of increased levels of follistatin and interleukin 4 expression. These data suggest that separated mutations within the same dystrophy-related gene may cause muscle degeneration through different mechanisms.
Insights
Mutations in caveolin-3 (Cav-3) cause limb-girdle muscular dystrophy. Different Cav-3 mutations lead to muscle degeneration via distinct molecular pathways, impacting AKT signaling and protein expression.
Area of Science:
- Muscle biology
- Cellular and molecular biology
- Biochemistry
Background:
- Caveolin-3 (Cav-3) is a key scaffolding protein in myofiber caveolae.
- Limb-girdle muscular dystrophy 1-C is associated with Cav-3 dysfunction.
- Understanding mutation-specific mechanisms is crucial for disease insight.
Purpose of the Study:
- To investigate the distinct cellular mechanisms caused by different dominant-negative Cav-3 mutations (P104L and DeltaTFT).
- To elucidate the impact of these mutations on C2C12 myoblast differentiation and myotube formation.
- To explore the role of AKT signaling and specific protein expressions in Cav-3-related muscular dystrophy.
Main Methods:
- Transfection of C2C12 myoblasts with dominant-negative Cav-3 constructs (P104L, DeltaTFT).
- Analysis of Cav-3 expression during C2C12 cell differentiation.
- Assessment of myofiber formation, AKT signaling pathways, and expression of Atrogin, follistatin, and interleukin 4.
Main Results:
- Both P104L and DeltaTFT mutations induced Cav-3 loss during myoblast differentiation.
- The P104L mutation impaired myofiber formation via reduced AKT signaling and increased Atrogin expression.
- The DeltaTFT mutation led to hypertrophic myotubes with sustained AKT activation, independent of follistatin and IL-4.
Conclusions:
- Distinct mutations within the Cav-3 gene can trigger muscle degeneration through divergent molecular pathways.
- The P104L mutation affects muscle formation through impaired AKT signaling and increased protein degradation.
- The DeltaTFT mutation promotes muscle hypertrophy via prolonged AKT activation, highlighting mutation-specific pathogenic mechanisms in muscular dystrophy.
