Cultured human muscle cells and respiratory chain deficiencies

Cultured muscle cells are useful in the study of respiratory chain disorders. Muscle tissue is affected in most cases and muscle biopsies are often taken for diagnostic purposes. Small samples of the biopsies can provide large numbers of muscle cells. In contrast with most other cell types, the muscle cells can differentiate in culture. Upon differentiation, multinuclear myotubes are formed by fusion of myoblasts and muscle-specific proteins are synthesized in the myotubes. Muscle cells can be used for diagnostic purposes, e.g. by measurement of the lactate and pyruvate synthesis, although with the limitation that not each form of respiratory chain deficiency may be expressed in culture. Muscle cells have been studied to obtain insight into mitochondrial DNA disorders, e.g. by investigation of cells after exposure to inhibitors of expression of mitochondrial DNA. Furthermore, cultured muscle cells have been studied to explore the potential of new therapeutic possibilities such as myoblast transfer and gene therapy.