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Updated: Apr 3, 2026
Immunolabelling Myofiber Degeneration in Muscle Biopsies
Published on: December 5, 2019
Immunoblot as a potential diagnostic tool for myofibrillar myopathies
Matteo Marini1, Valeria Guglielmi1, Georgine Faulkner2
1Department of Neurological and Movement Sciences, Section of Clinical Neurology, University of Verona, Verona, Italy.
Abstract:
Myofibrillar myopathies (MFMs) are a group of inherited or sporadic neuromuscular disorders morphologically characterized by foci of myofibril dissolution, disintegration of the Z-disk, and insoluble protein aggregates within the muscle fibers. The diagnosis is based on muscle biopsy. Light and electron microscopy has a central role in the diagnostic work up, and immunohistochemistry shows abnormal deposition of several proteins including αB-crystallin, desmin, and myotilin. In contrast, immunoblotting does not have any diagnostic value because it does not highlight differences in the amount of involved proteins. We investigated the pattern and level expression of desmin, αB-crystallin, myotilin, and ZASP (Z-band alternatively spliced PDZ motif-containing protein) in muscle of seven patients with MFMs by immunoblotting after SDS-PAGE and 2D-PAGE using two different solubilizing solutions, one radioimmunoprecipitation assay (RIPA) buffer, and the other urea-containing buffer. Our data demonstrated that urea-containing buffer improves the solubilization and recovery of desmin, αB-crystallin, myotilin, and ZASP as compared with RIPA buffer and that the total content of these proteins is increased in muscles of patients. The present results provide evidence that immunoblotting is an additional tool for confirming diagnosis of MFMs.
Insights
Myofibrillar myopathies (MFMs) are muscle disorders diagnosed via biopsy. This study shows immunoblotting with urea buffer can improve diagnosis by detecting increased key proteins like desmin and αB-crystallin in MFM patients.
Area of Science:
- Neurology
- Muscle Biology
- Biochemistry
Background:
- Myofibrillar myopathies (MFMs) are inherited or sporadic neuromuscular disorders.
- Diagnosis relies on muscle biopsy, with light/electron microscopy and immunohistochemistry being key.
- Current methods like immunoblotting are considered to have limited diagnostic value for MFMs.
Purpose of the Study:
- To investigate the expression patterns of desmin, αB-crystallin, myotilin, and ZASP in MFM patients.
- To evaluate the efficacy of different solubilizing buffers (RIPA vs. urea-containing) for immunoblotting in MFM diagnosis.
- To determine if immunoblotting can be an additional diagnostic tool for MFMs.
Main Methods:
- Muscle samples from seven MFM patients were analyzed.
- Immunoblotting techniques, including SDS-PAGE and 2D-PAGE, were employed.
- Two different solubilizing solutions, RIPA buffer and a urea-containing buffer, were compared.
Main Results:
- Urea-containing buffer significantly improved the solubilization and recovery of desmin, αB-crystallin, myotilin, and ZASP compared to RIPA buffer.
- The total content of these proteins was found to be increased in the muscle samples of MFM patients.
- Immunoblotting, particularly with the urea buffer, highlighted differences in protein levels.
Conclusions:
- Immunoblotting, when optimized with a urea-containing buffer, can serve as a valuable additional tool for confirming MFM diagnosis.
- The study demonstrates increased levels of specific proteins (desmin, αB-crystallin, myotilin, ZASP) in MFM patients.
- This refined immunoblotting approach enhances the diagnostic capabilities for myofibrillar myopathies.
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