MiR-186 Inhibits Muscle Cell Differentiation through Myogenin Regulation

Antonis Antoniou,Nikolaos P Mastroyiannopoulos,James B Uney,Leonidas A Phylactou

doi:10.1074/jbc.m113.507343

Abstract

The complex process of skeletal muscle differentiation is organized by the myogenic regulatory factors (MRFs), Myf5, MyoD, Myf6, and myogenin, where myogenin plays a critical role in the regulation of the final stage of muscle differentiation. In an effort to investigate the role microRNAs (miRNAs) play in regulating myogenin, a bioinformatics approach was used and six miRNAs (miR-182, miR-186, miR-135, miR-491, miR-329, and miR-96) were predicted to bind the myogenin 3'-untranslated region (UTR). However, luciferase assays showed only miR-186 inhibited translation and 3'-UTR mutagenesis analysis confirmed this interaction was specific. Interestingly, the expression of miR-186 mirrored that of its host gene, ZRANB2, during development. Functional studies demonstrated that miR-186 overexpression inhibited the differentiation of C2C12 and primary muscle cells. Our findings therefore identify miR-186 as a novel regulator of myogenic differentiation.

Highlights

Myogenin is a major muscle transcription factor that induces muscle cell differentiation and controls the final differentiation step of myogenesis
The binding energy predicted for miR-186 was likeliest to bind the myogenin 3Ј-untranslated region (UTR) and the binding site was conserved greater between closely related species compared with divergent species indicating possible evolutionary importance (Fig. 1C)
The human myogenin 3Ј-UTR was assayed under the same conditions to investigate whether the slight change in the binding site miRNA response element (MRE) for miR-186 could cause repression of luciferase activity as with mouse myogenin 3Ј-UTR

Summary

Introduction

Myogenin is a major muscle transcription factor that induces muscle cell differentiation and controls the final differentiation step of myogenesis. Results: microRNA-186 was identified as a post-transcriptional regulator of myogenin, which binds to its 3Ј-untranslated region resulting in its down-regulation. Conclusion: microRNA-186 causes inhibition of muscle cell differentiation through down-regulation of myogenin. The complex process of skeletal muscle differentiation is organized by the myogenic regulatory factors (MRFs), Myf, MyoD, Myf, and myogenin, where myogenin plays a critical role in the regulation of the final stage of muscle differentiation. In an effort to investigate the role microRNAs (miRNAs) play in regulating myogenin, a bioinformatics approach was used and six miRNAs (miR-182, miR-186, miR-135, miR-491, miR-329, and miR-96) were predicted to bind the myogenin 3؅-untranslated region (UTR). Our findings identify miR186 as a novel regulator of myogenic differentiation

Objectives

Results

Conclusion