Decrease of myofiber branching via muscle-specific expression of the olfactory receptor mOR23 in dystrophic muscle leads to protection against mechanical stress. Issue 1 (December 2015)

• Record Type: Journal Article
• Authors: Pichavant, Christophe; Burkholder, Thomas; Pavlath, Grace
• Is Part Of: Skeletal muscle. Volume 6:Issue 1(2016)
• Page Start: 1
• Page End: 9
• Publication Date: 2015-12
• Subjects: mOR23 -- Myofiber branching -- Mechanical stress -- Muscular dystrophy -- Muscle regeneration; Musculoskeletal system -- Periodicals; 612.7
• DOI: 10.1186/s13395-016-0077-7
• Languages: English
• ISSNs: 2044-5040

Abstract

Abstract Background Abnormal branched myofibers within skeletal muscles are commonly found in diverse animal models of muscular dystrophy as well as in patients. Branched myofibers from dystrophic mice are more susceptible to break than unbranched myofibers suggesting that muscles containing a high percentage of these myofibers are more prone to injury. Previous studies showed ubiquitous over-expression of mouse olfactory receptor 23 (mOR23), a G protein-coupled receptor, in wild type mice decreased myofiber branching. Whether mOR23 over-expression specifically in skeletal muscle cells is sufficient to mitigate myofiber branching in dystrophic muscle is unknown. Methods We created a novel transgenic mouse over-expressing mOR23 specifically in muscle cells and then bred with dystrophic (mdx ) mice. Myofiber branching was analyzed in these two transgenic mice and membrane integrity was assessed by Evans blue dye fluorescence. Results mOR23 over-expression in muscle led to a decrease of myofiber branching after muscle regeneration in non-dystrophic mouse muscles and reduced the severity of myofiber branching inmdx mouse muscles. Muscles frommdx mouse over-expressing mOR23 significantly exhibited less damage to eccentric contractions than controlmdx muscles. Conclusions The decrease of myofiber branching inmdx mouse muscles over-expressing mOR23 reduced the amount of membrane damage induced by mechanical stress. These results suggest that modifying myofiber branching in dystrophic patients, while not preventing degeneration, could be beneficial for mitigating some of the effects of the disease process.