Bish, Lawrence TSleeper, Margaret MMorine, Kevin JBarton, Elisabeth RSweeney, H. LeePendrak, Klara2023-05-232023-05-232010-02-112013-07-24https://repository.upenn.edu/handle/20.500.14332/48879Background: Myostatin inhibition is a promising therapeutic strategy to maintain muscle mass in a variety of disorders, including the muscular dystrophies, cachexia, and sarcopenia. Previously described approaches to blocking myostatin signaling include injection delivery of inhibitory propeptide domain or neutralizing antibodies. Methodology/Principal Findings: Here we describe a unique method of myostatin inhibition utilizing recombinant adeno-associated virus to overexpress a secretable dominant negative myostatin exclusively in the liver of mice. Systemic myostatin inhibition led to increased skeletal muscle mass and strength in control C57 Bl/6 mice and in the dystrophin-deficient mdx model of Duchenne muscular dystrophy. The mdx soleus, a mouse muscle more representative of human fiber type composition, demonstrated the most profound improvement in force production and a shift toward faster myosin-heavy chain isoforms. Unexpectedly, the 11-month-old mdx diaphragm was not rescued by long-term myostatin inhibition. Further, mdx mice treated for 11 months exhibited cardiac hypertrophy and impaired function in an inhibitor dose–dependent manner. Conclusions/Significance: Liver-targeted gene transfer of a myostatin inhibitor is a valuable tool for preclinical investigation of myostatin blockade and provides novel insights into the long-term effects and shortcomings of myostatin inhibition on striated muscle.© 2010 Morine et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited (http://creativecommons.org/licenses/by/3.0/).Comparative and Laboratory Animal MedicineDiseasesMedicine and Health SciencesMusculoskeletal DiseasesVeterinary MedicineArticle