miR-486 is essential for muscle function and suppresses a dystrophic transcriptome

Abstract

miR-486 is a muscle-enriched microRNA, or “myomiR,” that has reduced expression correlated with Duchenne muscular dystrophy (DMD). To determine the function of miR-486 in normal and dystrophin-deficient muscles and elucidate miR-486 target transcripts in skeletal muscle, we characterized mir-486 knockout mice (mir-486 KO). mir-486 KO mice developed disrupted myofiber architecture, decreased myofiber size, decreased locomotor activity, increased cardiac fibrosis, and metabolic defects were exacerbated in mir-486 KO:mdx5cv (DKO) mice. To identify direct in vivo miR-486 muscle target transcripts, we integrated RNA sequencing and chimeric miRNA eCLIP sequencing to identify key transcripts and pathways that contribute towards mir-486 KO and dystrophic disease pathologies. These targets included known and novel muscle metabolic and dystrophic structural remodeling factors of muscle and skeletal muscle contractile transcript targets. Together, our studies identify miR-486 as essential for normal muscle function, a driver of pathological remodeling in dystrophin-deficient muscle, a useful biomarker for dystrophic disease progression, and highlight the use of multiple omic platforms to identify in vivo microRNA target transcripts.

Extracellular vesicle characteristics and microRNA content in cerebral palsy and typically developed individuals at rest and in response to aerobic exercise

“…The complete list of differentially expressed genes and gene ontologies is presented in Supplementary Table S2 . To deepen our understanding and interpretation of the changes induced by the miR-486 mimetic, we compared the differentially expressed gene list obtained from the current C2C12 cell data set with DEG lists originated from hamstrings ( Smith et al, 2012 ) and wrist ( Smith et al, 2009 ) skeletal muscle of CP individuals, as well as muscle from miR-486-KO mice ( Samani et al, 2022 ) ( Supplementary Figure S4 and Supplementary Table S2 ). Among the genes differentially expressed in our C2C12 experiments and in CP skeletal muscle, we identified mediators of insulin growth factors ( IGFBP5 ), regulators of the organization of the actin filament system ( RHOBTB1 ), several collagen related genes (e.g., COL1A1, COL3A1, COL4A1, COL5A1 ), and myosin heavy chain ( MYH1, MYH3 ) related genes.…”

Characteristics of microRNAs in Skeletal Muscle of Intrauterine Growth-Restricted Pigs

“…In another study, leucine-induced upregulation of miR-27a inhibited myostatin mRNA expression and proliferation of C2C12 [58]. Samani conducted the in vivo knockout of miR-486 in mice, and mir-486 KO mice showed the overall destruction of muscle fiber structure, decreased cross-sectional area of muscle fiber, and increased fibrosis [59]. Zhang found that circMEF2D regulated the PI3K-AKT signaling pathway by binding to miR-486 and inhibited the proliferation and differentiation of bovine myoblasts [60].…”

“…In C2C12 cells, miR-26a can directly target Smad1 and Smad4 to promote differentiation of myogenic cells, whereas the inhibition of miR-26a expression leads to delayed differentiation and skeletal muscle regeneration [61]. miR-101-1 inhibited C2C12 cell differentiation and reduced myotube formation by inhibiting Myod, Myog, and Myhc mRNA and protein expression [62].In addition, miR-486 [59,60], miR-122-5p [63], miR-503 [64,65], miR-7-5p [65], miR-142-5p [66,67], miR-1343 [68], miR-101 [69], miR-21-5p [70], and miR-26a [61] all play important regulatory roles in skeletal muscle development. However, the mechanism of these miRNAs in the skeletal muscle of the IUGR model remains to be further studied.…”

Extracellular vesicles and Duchenne muscular dystrophy pathology: Modulators of disease progression

“…These miRNAs include miR-199a-5p (upregulated in DMD muscle cells and downregulated in DMD fibroblasts ( Zanotti et al, 2018 )), involved in the wingless-related integration site (WNT) signaling pathway (targeting numerous myogenic cell proliferation and differentiation regulatory factors) ( Alexander et al, 2013 ), and miR-29, a targeter of AKT Serine/Threonine Kinase 3 (AKT3)/nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kB)/Yin Yang1 (YY1) signaling and fibrotic genes ( Wang et al, 2012 ). Recently, miR-486 has also been revealed to play an essential role in muscle function and is found to be significantly downregulated in DMD ( Samani et al, 2022 ). The loss of this miRNA has been associated with disrupted muscle architecture, reduced myofiber size, and increased cardiac fibrosis, just to name a few.…”