Regulation of DMD pathology by an ankyrin-encoded miRNA.

Academic Article

Abstract

  • BACKGROUND: Duchenne muscular dystrophy (DMD) is an X-linked myopathy resulting from the production of a nonfunctional dystrophin protein. MicroRNA (miRNA) are small 21- to 24-nucleotide RNA that can regulate both individual genes and entire cell signaling pathways. Previously, we identified several mRNA, both muscle-enriched and inflammation-induced, that are dysregulated in the skeletal muscles of DMD patients. One particularly muscle-enriched miRNA, miR-486, is significantly downregulated in dystrophin-deficient mouse and human skeletal muscles. miR-486 is embedded within the ANKYRIN1(ANK1) gene locus, which is transcribed as either a long (erythroid-enriched) or a short (heart muscle- and skeletal muscle-enriched) isoform, depending on the cell and tissue types. RESULTS: Inhibition of miR-486 in normal muscle myoblasts results in inhibited migration and failure to repair a wound in primary myoblast cell cultures. Conversely, overexpression of miR-486 in primary myoblast cell cultures results in increased proliferation with no changes in cellular apoptosis. Using bioinformatics and miRNA reporter assays, we have identified platelet-derived growth factor receptor β, along with several other downstream targets of the phosphatase and tensin homolog deleted on chromosome 10/AKT (PTEN/AKT) pathway, as being modulated by miR-486. The generation of muscle-specific transgenic mice that overexpress miR-486 revealed that miR-486 alters the cell cycle kinetics of regenerated myofibers in vivo, as these mice had impaired muscle regeneration. CONCLUSIONS: These studies demonstrate a link for miR-486 as a regulator of the PTEN/AKT pathway in dystrophin-deficient muscle and an important factor in the regulation of DMD muscle pathology.
  • Published In

  • Skeletal Muscle  Journal
  • Digital Object Identifier (doi)

    Author List

  • Alexander MS; Casar JC; Motohashi N; Myers JA; Eisenberg I; Gonzalez RT; Estrella EA; Kang PB; Kawahara G; Kunkel LM
  • Start Page

  • 27
  • Volume

  • 1