title: Long-term analysis of differentiation in human myoblasts repopulated with mitochondria harboring mtDNA mutations.
abstract: Short-term analysis of myogenesis in respiration-deficient myoblasts demonstrated that respiratory chain dysfunction impairs muscle differentiation. To investigate long-term consequences of a deficiency in oxidative phosphorylation on myogenesis, we quantitated myoblast fusion and expression of sarcomeric myosin in respiration-deficient myogenic cybrids. We produced viable myoblasts harboring exclusively mtDNA with large-scale deletions by treating wild-type myoblasts with rhodamine 6G and fusing them with cytoplasts homoplasmic for two different mutated mtDNAs. Recovery of growth in transmitochondrial myoblasts demonstrated that respiratory chain function is not required for recovery of rhodamine 6G-treated cells. Both transmitochondrial respiration-deficient cultures exhibited impaired myoblast fusion. Expression of sarcomeric myosin was also delayed in deficient myoblasts. However, 4 weeks after induction of differentiation, one cell line was able to quantitatively recover its capacity to form postmitotic muscle cells. This indicates that while oxidative phosphorylation is an important source of ATP for muscle development, myoblast differentiation can be supported entirely by glycolysis.
authors.affiliation: College of Physicians and Surgeons, Columbia University, New York, New York, 10032, USA.
authors.forename: C
authors.initials: C
authors.lastname: Sobreira
authors.forename: M P
authors.initials: MP
authors.lastname: King
authors.forename: M M
authors.initials: MM
authors.lastname: Davidson
authors.forename: H
authors.initials: H
authors.lastname: Park
authors.forename: Y
authors.initials: Y
authors.lastname: Koga
authors.forename: A F
authors.initials: AF
authors.lastname: Miranda
mesh_terms: D015415:Biomarkers / Q000032:analysis; D002454:Cell Differentiation / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D002459:Cell Fusion; D002467:Cell Nucleus / Q000187:drug effects / Q000378:metabolism; D019069:Cell Respiration / Q000187:drug effects / Q000235:genetics / Q000502:physiology; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D004252:DNA Mutational Analysis; D004272:DNA, Mitochondrial / Q000235:genetics*; D004305:Dose-Response Relationship, Drug; D004579:Electron Transport / Q000187:drug effects / Q000235:genetics / Q000502:physiology; D006801:Humans; D007150:Immunohistochemistry; D008928:Mitochondria / Q000187:drug effects / Q000201:enzymology / Q000235:genetics* / Q000378:metabolism*; D009132:Muscles / Q000166:cytology* / Q000187:drug effects / Q000201:enzymology; D010085:Oxidative Phosphorylation / Q000187:drug effects; D012235:Rhodamines / Q000494:pharmacology; D017384:Sequence Deletion / Q000235:genetics*
chemical_list: D015415:Biomarkers; D004272:DNA, Mitochondrial; D012235:Rhodamines; C026188:rhodamine 6G