title: Calcium homeostasis in myogenic differentiation factor 1 (MyoD)-transformed, virally-transduced, skin-derived equine myotubes.
abstract: Dysfunctional skeletal muscle calcium homeostasis plays a central role in the pathophysiology of several human and animal skeletal muscle disorders, in particular, genetic disorders associated with ryanodine receptor 1 (RYR1) mutations, such as malignant hyperthermia, central core disease, multiminicore disease and certain centronuclear myopathies. In addition, aberrant skeletal muscle calcium handling is believed to play a pivotal role in the highly prevalent disorder of Thoroughbred racehorses, known as Recurrent Exertional Rhabdomyolysis. Traditionally, such defects were studied in human and equine subjects by examining the contractile responses of biopsied muscle strips exposed to caffeine, a potent RYR1 agonist. However, this test is not widely available and, due to its invasive nature, is potentially less suitable for valuable animals in training or in the human paediatric setting. Furthermore, increasingly, RYR1 gene polymorphisms (of unknown pathogenicity and significance) are being identified through next generation sequencing projects. Consequently, we have investigated a less invasive test that can be used to study calcium homeostasis in cultured, skin-derived fibroblasts that are converted to the muscle lineage by viral transduction with a MyoD (myogenic differentiation 1) transgene. Similar models have been utilised to examine calcium homeostasis in human patient cells, however, to date, there has been no detailed assessment of the cells' calcium homeostasis, and in particular, the responses to agonists and antagonists of RYR1. Here we describe experiments conducted to assess calcium handling of the cells and examine responses to treatment with dantrolene, a drug commonly used for prophylaxis of recurrent exertional rhabdomyolysis in horses and malignant hyperthermia in humans.
authors.affiliation: Comparative Neuromuscular Diseases Laboratory, Department of Clinical Sciences and Services, Royal Veterinary College, London, United Kingdom.
authors.forename: Marta
authors.initials: M
authors.lastname: Fernandez-Fuente
authors.affiliation: Laboratory of Cell Electrophysiology, Imperial College London, Myocardial Function, National Heart and Lung Institute, Hammersmith Hospital, London, United Kingdom.
authors.forename: Cesare M
authors.initials: CM
authors.lastname: Terracciano
authors.affiliation: Universidad Francisco de Vitoria, Facultad de Ciencias Biosanitarias: Pozuelo de Alarcón (Madrid), Madrid, Spain.
authors.forename: Pilar
authors.initials: P
authors.lastname: Martin-Duque
authors.affiliation: Comparative Biomedical Sciences, Royal Veterinary College, London, United Kingdom.
authors.forename: Susan C
authors.initials: SC
authors.lastname: Brown
authors.affiliation: Laboratoire TIRO, UMRE 4320, iBEB, DSV, Commissariat a' l'Energie Atomique, Nice, France.
authors.forename: Georges
authors.initials: G
authors.lastname: Vassaux
authors.affiliation: Comparative Neuromuscular Diseases Laboratory, Department of Clinical Sciences and Services, Royal Veterinary College, London, United Kingdom.
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Piercy
mesh_terms: D000818:Animals; D002110:Caffeine / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism*; D002120:Calcium Channel Agonists / Q000494:pharmacology; D002121:Calcium Channel Blockers / Q000494:pharmacology; D002478:Cells, Cultured; D003620:Dantrolene / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D057809:HEK293 Cells; D006706:Homeostasis / Q000187:drug effects; D006736:Horses; D006801:Humans; D018485:Muscle Fibers, Skeletal / Q000187:drug effects / Q000378:metabolism*; D017570:MyoD Protein / Q000235:genetics* / Q000378:metabolism; D012867:Skin / Q000166:cytology*; D019284:Thapsigargin / Q000494:pharmacology; D014161:Transduction, Genetic; D019076:Transgenes
chemical_list: D002120:Calcium Channel Agonists; D002121:Calcium Channel Blockers; D017570:MyoD Protein; C057363:MyoD1 myogenic differentiation protein; D002110:Caffeine; D019284:Thapsigargin; D003620:Dantrolene; D002118:Calcium