In vitro exercise model using contractile human and mouse hybrid myotubes

• Published in: Scientific reports 2019-08, Vol.9 (1), p.11914-9, Article 11914
• Main Authors: Chen, Weijian, Nyasha, Mazvita R., Koide, Masashi, Tsuchiya, Masahiro, Suzuki, Naoki, Hagiwara, Yoshihiro, Aoki, Masashi, Kanzaki, Makoto
• Format: Article
• Language: English
• Subjects: 13; 13/106; 13/95; 631/1647/1407/651; 692/163/2743/2037; 96/21; Animals; Biopsy; CC chemokines; CCL17 protein; CCL19 protein; CCL20 protein; CCL21 protein; CCL22 protein; Cell Fusion; Cells, Cultured; Chemokines; Contraction; CXC chemokines; CXCL10 protein; Cytokines - genetics; Cytokines - metabolism; Electric Stimulation; Exercise; Humanities and Social Sciences; Humans; Hybrid Cells - physiology; Interleukin 1; Interleukin 10; Interleukin 16; Interleukin 6; Interleukin 8; Male; Mice; Middle Aged; Models, Biological; Monocyte chemoattractant protein 1; multidisciplinary; Muscle contraction; Muscle Contraction - physiology; Muscle Fibers, Skeletal - physiology; Myoblasts - physiology; Myotubes; Polymerase chain reaction; Satellite Cells, Skeletal Muscle - cytology; Science; Science (multidisciplinary); Secretions; γ-Interferon
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-019-48316-9

Contraction of cultured myotubes with application of electric pulse stimulation (EPS) has been utilized for investigating cellular responses associated with actual contractile activity. However, cultured myotubes derived from human subjects often exhibit relatively poor EPS-evoked contractile activity, resulting in minimal contraction-inducible responses ( i . e . myokine secretion). We herein describe an “ in vitro exercise model”, using hybrid myotubes comprised of human myoblasts and murine C2C12 myoblasts, exhibiting vigorous contractile activity in response to EPS. Species-specific analyses including RT-PCR and the BioPlex assay allowed us to separately evaluate contraction-inducible gene expressions and myokine secretions from human and mouse constituents of hybrid myotubes. The hybrid myotubes, half of which had arisen from primary human satellite cells obtained from biopsy samples, exhibited remarkable increases in the secretions of human cytokines (myokines) including interleukins (IL-6, IL-8, IL-10, and IL16), CXC chemokines (CXCL1, CXCL2, CXCL5, CXCL6, CXCL10), CC chemokines (CCL1, CCL2, CCL7, CCL8, CCL11, CCL13, CCL16, CCL17, CCL19, CCL20, CCL21, CCL22, CCL25, CCL27), and IFN-γ in response to EPS-evoked contractile activity. Together, these results indicate that inadequacies arising from human muscle cells are effectively overcome by fusing them with murine C2C12 cells, thereby supporting the development of contractility and the resulting cellular responses of human-origin muscle cells. Our approach, using hybrid myotubes, further expands the usefulness of the “ in vitro exercise model”.