Screening Of The Myostatin Regulation Of Micrornas

Myostatin, also named as Growth and Differentiation Factor 8 (GDF8), belongs to TGF-P super family. It is a secreted protein that acts as a negative regulator of skeletal muscle development. During embryogenesis, myostatin is expressed in the proliferating cells in the myotome and fetal skeletal muscle tissue and functions to regulate the final number of muscle fibers. During postnatal myogenesis, myostatin protein is mainly produced by skeletal muscle and functions to regulate muscle mass.As a kind of important regulators of myogenesis, miRNAs biogenesis should be precisely regulated during muscle development. However, the current studies on miRNA biogenesis mainly focus on the miRNA maturation (post-transciptional proceesing of primary miRNAs into marure miRNA). Thers is largely unknown about transcriptional regulation of miRNAs, including promoter indentification and transcriptional factor characterization. Herein, we tried to identify myostatin-responsive miRNAs by screening of the differentially expressed miRNAs in the skeletal muscle between myostatin knockout mice and their littermates.Total RNAs were extracted from day 15.5 embryonic mice, postnatal 4-week, 10week,16-week and 41-week mice skeletal muscles. Based on miRNA microarrays, 105 miRNAs were indentified through bioinformatics.10 differentially expressed miRNAs between 4-week myostatin knockout mice skeletal muscles and their littermates'were validated by real-time RT-PCR. Among the validation results,5 miRNAs had the same change pattern with the microarray data.3 miRNAs were not consistent with the microarray data. And two had no change. The outcomes lay an important foundation for the further study of miRNAs regulated by myostatin.