title: In vitro Differentiation of Functional Human Skeletal Myotubes in a Defined System.
abstract: In vitrohuman skeletal muscle systems are valuable tools for the study of human muscular development, disease and treatment. However, publishedin vitrohuman muscle systems have so far only demonstrated limited differentiation capacities. Advanced differentiation features such as cross-striations and contractility have only been observed in co-cultures with motoneurons. Furthermore, it is commonly regarded that cultured human myotubes do not spontaneously contract, and any contraction has been considered to originate from innervation. This study developed a serum-free culture system in which human skeletal myotubes demonstrated advanced differentiation. Characterization by immunocytochemistry, electrophysiology and analysis of contractile function revealed these major features: A) well defined sarcomeric development, as demonstrated by the presence of cross-striations. B) finely developed excitation-contraction coupling apparatus characterized by the close apposition of dihydropyridine receptors on T-tubules and Ryanodine receptors on sarcoplasmic reticulum membranes. C) spontaneous and electrically controlled contractility. This report not only demonstrates an improved level of differentiation of cultured human skeletal myotubes, but also provides the first published evidence that such myotubes are capable of spontaneous contraction. Use of this functionalin vitrohuman skeletal muscle system would advance studies concerning human skeletal muscle development and physiology, as well as muscle-related disease and therapy.
authors: NanoScience Technology Center, University of Central Florida, Orlando, Florida 32826, USA.
authors: Xiufang
authors: X
authors: Guo
authors: Biomolecular Science Center, Burnett School of Biomedical Sciences, University of Central Florida, Orlando, Florida 32826, USA.
authors: Keshel
authors: K
authors: Greene
authors: NanoScience Technology Center, University of Central Florida, Orlando, Florida 32826, USA.
authors: Nesar
authors: N
authors: Akanda
authors: NanoScience Technology Center, University of Central Florida, Orlando, Florida 32826, USA.
authors: Alec
authors: A
authors: Smith
authors: NanoScience Technology Center, University of Central Florida, Orlando, Florida 32826, USA ; Department of Chemistry, 4000 Central Florida Blvd., Physical Sciences Building (PS) Room 255, University of Central Florida, Orlando, FL 32816-2366, USA.
authors: Maria
authors: M
authors: Stancescu
authors: NanoScience Technology Center, University of Central Florida, Orlando, Florida 32826, USA ; College of Medicine, University of Central Florida, 12201 Research Parkway, Suite 479, Room 463, Orlando, FL 32826, USA.
authors: Stephen
authors: S
authors: Lambert
authors: Brown University, Professor Emeritus, Department of Pathology and Lab Medicine, Providence, Rhode Island, 02913 USA ; Myomics, 148 West River Str, Providence, Rhode Island 02904.
authors: Herman
authors: H
authors: Vandenburgh
authors: NanoScience Technology Center, University of Central Florida, Orlando, Florida 32826, USA ; Biomolecular Science Center, Burnett School of Biomedical Sciences, University of Central Florida, Orlando, Florida 32826, USA ; Department of Chemistry, 4000 Central Florida Blvd., Physical Sciences Building (PS) Room 255, University of Central Florida, Orlando, FL 32816-2366, USA.
authors: James
authors: J
authors: Hickman