Lack of Myostatin Reduces MyoD Induced Myogenic Potential of Primary Muscle Fibroblasts

Authors

  • Sudheer Shenoy P,

    1. School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
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  • Bipasha Bose,

    1. School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
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  • Mridula Sharma,

    1. Department of Biochemistry, YLL School of Medicine, National University of Singapore, Singapore, Singapore
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  • Craig McFarlane,

    1. Singapore Institute for Clinical Sciences, A*STAR, 30 Medical Centre Drive, National University of Singapore, Singapore, Singapore
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  • Ravi Kambadur

    Corresponding author
    1. School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
    2. Singapore Institute for Clinical Sciences, A*STAR, 30 Medical Centre Drive, National University of Singapore, Singapore, Singapore
    • Correspondence to: Professor Ravi Kambadur, School of Biological Sciences, Nanyang Technological University, 60, Nanyang Drive, Singapore 637551, Singapore. E-mail: kravi@ntu.edu.sg

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  • The authors declared that they have no conflicts of interest.
  • Sudheer Shenoy P and Bipasha Bose contributed equally to this work.

ABSTRACT

Conversion of skin fibroblasts into myoblasts by transducing the cells with myogenic master regulator MyoD has been in practice for more than two decades. The purpose of such conversion is due to scarcity of muscle biopsies during muscle wasting, hence conversion of fibroblasts to myogenic lineage from various genetic backgrounds offers a great alternative for cell therapies. Here, we have investigated if eliminating Myostatin, a potent negative regulator of myogenesis, could improve the myogenic conversion of fibroblasts. In the present study, we have isolated primary muscle fibroblasts from the skeletal muscles of wild-type (WT) and myostatin null (Mstn−/−) mice and transduced the muscle fibroblasts with MyoD using adenoviral, lentiviral transduction, and electroporation methods. In contrast to what we predicted, it is only in WT muscle fibroblasts we detected significant ectopic expression of MyoD, and myogenic conversion. Muscle fibroblasts from Mstn−/− genotype failed to take up as much MyoD using the three methods and, therefore, failed to form myotubes. The aforesaid condition of greater MyoD uptake by WT muscle fibroblasts was attributed to the presence of adenoviral receptors, which facilitated adenoviral transduction. However, in Mstn−/− fibroblasts we detected negligible levels of adenovirus receptors. Moreover, we also detected significantly higher levels of MyoD antagonists, c-Fos, c-Jun, and cyclin D1 in Mstn−/− muscle fibroblasts. Taken together, our results demonstrate that lack of myostatin reduces myogenic potential of muscle fibroblasts by inhibiting MyoD function. J. Cell. Biochem. 115: 1908–1917, 2014. © 2014 Wiley Periodicals, Inc.

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