Cultured muscle cells display defects of mitochondrial myopathy ameliorated by anti-oxidants.
The mitochondrial DNA A3243G mutation causes neuromuscular disease. To investigate the muscle-specific pathophysiology of mitochondrial disease, rhabdomyosarcoma transmitochondrial hybrid cells (cybrids) were generated that retain the capacity to differentiate to myotubes. In some cases, striated muscle-like fibres were formed after innervation with rat embryonic spinal cord. Myotubes carrying A3243G mtDNA produced more reactive oxygen species than controls, and had altered glutathione homeostasis. Moreover, A3243G mutant myotubes showed evidence of abnormal mitochondrial distribution, which was associated with down-regulation of three genes involved in mitochondrial morphology, Mfn1, Mfn2 and DRP1. Electron microscopy revealed mitochondria with ultrastructural abnormalities and paracrystalline inclusions. All these features were ameliorated by anti-oxidant treatment, with the exception of the paracrystalline inclusions. These data suggest that rhabdomyosarcoma cybrids are a valid cellular model for studying muscle-specific features of mitochondrial disease and that excess reactive oxygen species production is a significant contributor to mitochondrial dysfunction, which is amenable to anti-oxidant therapy.
Vergani
Lodovica
L
c/o Venetian Institute of Molecular Medicine, via Orus, 2; 35129 Padova, Italy E-mail: lodovica.vergani@unipd.it.
Malena
Adriana
A
Sabatelli
Patrizia
P
Loro
Emanuele
E
Cavallini
Lucia
L
Magalhaes
Paolo
P
Valente
Lucia
L
Bragantini
Federica
F
Carrara
Franco
F
Leger
Bertrand
B
Poulton
Joanna
J
Russell
Aaron P
AP
Holt
Ian J
IJ
D000328:Adult; D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D002454:Cell Differentiation; D002478:Cells, Cultured; D004272:DNA, Mitochondrial / Q000235:genetics; D005786:Gene Expression Regulation; D006801:Humans; D008297:Male; D008854:Microscopy, Electron; D008931:Mitochondria, Muscle / Q000187:drug effects / Q000648:ultrastructure; D017240:Mitochondrial Myopathies / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D032342:Muscle Cells / Q000187:drug effects / Q000648:ultrastructure*; D018485:Muscle Fibers, Skeletal / Q000378:metabolism; D010084:Oxidation-Reduction; D051381:Rats; D017207:Rats, Sprague-Dawley; D017382:Reactive Oxygen Species / Q000378:metabolism; D014407:Tumor Cells, Cultured
D000975:Antioxidants; D004272:DNA, Mitochondrial; D017382:Reactive Oxygen Species