MicroRNA-486-dependent modulation of DOCK3/PTEN/AKT signaling pathways improves muscular dystrophy-associated symptoms.
Duchenne muscular dystrophy (DMD) is caused by mutations in the gene encoding dystrophin, which results in dysfunctional signaling pathways within muscle. Previously, we identified microRNA-486 (miR-486) as a muscle-enriched microRNA that is markedly reduced in the muscles of dystrophin-deficient mice (Dmdmdx-5Cv mice) and in DMD patient muscles. Here, we determined that muscle-specific transgenic overexpression of miR-486 in muscle of Dmdmdx-5Cv mice results in reduced serum creatine kinase levels, improved sarcolemmal integrity, fewer centralized myonuclei, increased myofiber size, and improved muscle physiology and performance. Additionally, we identified dedicator of cytokinesis 3 (DOCK3) as a miR-486 target in skeletal muscle and determined that DOCK3 expression is induced in dystrophic muscles. DOCK3 overexpression in human myotubes modulated PTEN/AKT signaling, which regulates muscle hypertrophy and growth, and induced apoptosis. Furthermore, several components of the PTEN/AKT pathway were markedly modulated by miR-486 in dystrophin-deficient muscle. Skeletal muscle-specific miR-486 overexpression in Dmdmdx-5Cv animals decreased levels of DOCK3, reduced PTEN expression, and subsequently increased levels of phosphorylated AKT, which resulted in an overall beneficial effect. Together, these studies demonstrate that stable overexpression of miR-486 ameliorates the disease progression of dystrophin-deficient skeletal muscle.
Matthew S
MS
Alexander
Juan Carlos
JC
Casar
Norio
N
Motohashi
Natássia M
NM
Vieira
Iris
I
Eisenberg
Jamie L
JL
Marshall
Molly J
MJ
Gasperini
Angela
A
Lek
Jennifer A
JA
Myers
Elicia A
EA
Estrella
Peter B
PB
Kang
Frederic
F
Shapiro
Fedik
F
Rahimov
Genri
G
Kawahara
Jeffrey J
JJ
Widrick
Louis M
LM
Kunkel
D000818:Animals; D001483:Base Sequence; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D020662:Guanine Nucleotide Exchange Factors / Q000235:genetics / Q000378:metabolism; D006801:Humans; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018101:Mice, Inbred mdx; D008822:Mice, Transgenic; D035683:MicroRNAs / Q000235:genetics* / Q000378:metabolism*; D018485:Muscle Fibers, Skeletal / Q000378:metabolism / Q000473:pathology; D018482:Muscle, Skeletal / Q000378:metabolism / Q000473:pathology; D009137:Muscular Dystrophy, Animal / Q000235:genetics* / Q000378:metabolism* / Q000473:pathology; D020388:Muscular Dystrophy, Duchenne / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism*; D051059:PTEN Phosphohydrolase / Q000378:metabolism*; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism*; D012689:Sequence Homology, Nucleic Acid; D015398:Signal Transduction; D015854:Up-Regulation
D002352:Carrier Proteins; C485840:DOCK3 protein, human; C410623:Dock3 protein, mouse; D020662:Guanine Nucleotide Exchange Factors; C560945:MIRN486 microRNA, human; C583982:MIRN486 microRNA, mouse; D035683:MicroRNAs; D009419:Nerve Tissue Proteins; D051057:Proto-Oncogene Proteins c-akt; D051059:PTEN Phosphohydrolase; C494929:PTEN protein, human; C487757:Pten protein, mouse