Myostatin genotype regulates muscle-specific miRNA expression in mouse pectoralis muscle

Background. Loss of functional Myostatin results in a dramatic increase in skeletal muscle mass. It is unknown what role miRNAs play in Myostatin mediated repression of skeletal muscle mass. We hypothesized that Myostatin genotype would be associated with the differential expression of miRNAs in skeletal muscle. Findings. Loss of functional Myostatin resulted in a significant increase (p < .001) in miR-1, miR-133a, miR-133b, and miR-206 expression. In contrast, Myostatin genotype had no effect (P > .2) on miR-24 expression level. Myostatin genotype did not affect the expression level of MyoD or Myogenin (P > 0.5). Conclusions. Myostatin may regulates the expression of miRNAs such as miR-133a, miR-133b, miR-1, and miR-206 in skeletal muscle as it has been observed that the expression of those miRNAs are significantly higher in myostatin null mice compared to wild type and heterozygous mice. In contrast, expression of myogenic factors such as MyoD or Myogenin has not been affected by myostatin in the muscle tissue.