Caveolin-3 is aberrantly expressed in skeletal muscle cells in myasthenia gravis

- Some myasthenia gravis (MG) muscles showed patchy caveolin-3 distribution.
- Partial loss of caveolin-3 expression was relatively common in MG muscle.
- Strong membrane localization of caveolin-3 was noted in 66% of MG patients.
- Caveolin-3 mRNA/protein levels were higher in MG vs. control-patient muscles.
- Caveolin-3 upregulation may be required after MG muscle damage.

Caveolin-3 is a muscle-specific membrane protein that localizes to the sarcolemma and T-tubule system. Caveolin-3 is needed for muscle repair and skeletal muscle development. The objective of this study was to compare caveolin-3 expression in myasthenia gravis (MG) and control muscles. Caveolin-3 was abnormally expressed in the MG muscle membrane, with partial loss of expression and overexpression in 5/15 and 10/15 patients, respectively. Caveolin-3 mRNA and protein levels were higher in MG than in control muscles, suggesting that partial deficiency of caveolin-3 is occasionally detected in MG muscle and that caveolin-3 overexpression may be required after MG muscle damage.

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