MiR-486 is an Epigenetic Regulator of the Pathological Progression of Duchenne Muscular Dystrophy


Muscle Regeneration in Disease (includes satellite cells)

Poster Number: 106


Rylie Hightower, BSN, RN, Andrea L. Reid, PhD, Adrienne Samani, BS, Yimin Wang, PhD, Ganesh Halade, Thomas van Groen, Matthew Alexander, PhD


1. University of Alabama at Birmingham, 2. University of Alabama Birmingham and Children’s Alabama, 3. University of Alabama at Birmingham, 4. University of Alabama at Birmingham, 5. University of Alabama at Birmingham, 6. University of Alabama at Birmingham, 7. Children's of Alabama/University of Alabama at Birmingham

Duchenne muscular dystrophy (DMD) is the most common form of muscular dystrophy worldwide. Patients with this X-linked neuromuscular disorder develop progressive muscle weakness, ambulation loss, cardiac arrhythmias, and respiratory complications. DMD is caused by non-functional mutations in the DYSTROPHIN gene, resulting in myofiber breakdown and eventual patient lethality. Muscle microRNAs (or myomiRs) play critical roles in muscle development and the progression of dystrophic pathology. Previously our lab demonstrated that miR-486 expression is decreased in DMD patients and mouse models in correlation with DMD disease severity. In addition, overexpression of miR-486 in dystrophin-deficient mice can ameliorate pathology. To determine the role of miR-486 in striated muscle we generated miR-486 on both WT and dystrophin-deficient (mdx5cv) mouse backgrounds. Physiological assays and molecular techniques were used to assess global physical function, striated muscle development and maintenance, and potential drivers of dysregulated miR-486 expression both in vivo and in vitro. MiR-486 KO and miR-486;mdx5cv double KO resulted in abnormal myofiber architecture, increased centralized myonuclei, reduced physical activity, decreased lean mass, and decreased cardiac function in male mice by 6 months. This demonstrates that miR-486 is crucial to proper muscle architecture and function in WT mice and that expression levels play a significant contributory role in progression of disease in dystrophic mdx5cv mice. Based on these findings, we have begun additional experiments focused on identifying and validating miR-486 target transcripts to determine the contribution of miR-486 to muscle maintenance, metabolism, and hypertrophy. Further experiments will determine at what stage miR-486 expression can rescue or ameliorate dystrophic pathologies and its utility as a candidate for gene therapy.