Differential microRNA Expression in Fast- and Slow-Twitch Skeletal Muscle of Piaractus mesopotamicus during Growth

Abstract

Pacu (Piaractus mesopotamicus) is a Brazilian fish with a high economic value in pisciculture due to its rusticity and fast growth. Postnatal growth of skeletal muscle in fish occurs by hyperplasia and/or hypertrophy, processes that are dependent on the proliferation and differentiation of myoblasts. A class of small noncoding RNAs, known as microRNAs (miRNAs), represses the expression of target mRNAs, and many studies have demonstrated that miR-1, miR-133, miR-206 and miR-499 regulate different processes in skeletal muscle through the mRNA silencing of hdac4 (histone deacetylase 4), srf (serum response factor), pax7 (paired box 7) and sox6 ((sex determining region Y)-box 6), respectively. The aim of our work was to evaluate the expression of these miRNAs and their putative target mRNAs in fast- and slow-twitch skeletal muscle of pacu during growth. We used pacus in three different development stages: larval (aged 30 days), juvenile (aged 90 days and 150 days) and adult (aged 2 years). To complement our study, we also performed a pacu myoblast cell culture, which allowed us to investigate miRNA expression in the progression from myoblast proliferation to differentiation. Our results revealed an inverse correlation between the expression of the miRNAs and their target mRNAs, and there was evidence that miR-1 and miR-206 may regulate the differentiation of myoblasts, whereas miR-133 may regulate the proliferation of these cells. miR-499 was highly expressed in slow-twitch muscle, which suggests its involvement in the specification of the slow phenotype in muscle fibers. The expression of these miRNAs exhibited variations between different development stages and between distinct muscle twitch phenotypes. This work provides the first identification of miRNA expression profiles in pacu skeletal muscle and suggests an important role of these molecules in muscle growth and in the maintenance of the muscle phenotype.

Food restriction increase the expression of mTORC1 complex genes in the skeletal muscle of juvenile pacu (Piaractus mesopotamicus)

“…Chu et al [84]described, in juvenile Siniperca chuatsi , that several miRNAs highly expressed in fast muscle had lower expression in slow muscle and that miRNAs highly expressed in slow muscle had lower expression in fast muscle. This finding was also observed in our laboratory, where a difference in miRNA expression between fast and slow muscles in pacus during development was described [85]. Similar results were found in the present experiment, where we observed an increase in miR-1 and miR-206 expression in fast muscle and a decrease of miR-206 in slow muscle after refeeding, also described by Wiberg et al [86] in the soleus and gastrocnemius of mice subjected to denervation.…”

Fishing Into the MicroRNA Transcriptome

“…The pacu ( Piaractus mesopotamicus ), which is characterized by hardiness, fast growth, adaptation to artificial feeding and flavorsome meat (Castagnolli and Cyrino, 1986 ), is a valuable resource in Brazilian aquaculture (Urbinati and Gonçalves, 2005 ). Duran et al ( 2015 ) and Paula et al ( 2017 ) studied the role of skeletal muscle miRNAs in this Neotropical fish during development and under food restriction, respectively. Duran et al ( 2015 ) analyzed the impact of the miRNA-target interactions of miR-1/ hdac4 , miR-133-a/b/ srf , miR-206/ pax7 , and miR-499/ sox6 in fast- and slow-twitch skeletal muscles during growth.…”

miR-210 expression is associated with methionine-induced differentiation of trout satellite cells

“…In tilapia (Oreochromis niloticus), it has been shown that miR-206 regulates muscle growth by targeting the 3′-UTR of IGF-1 transcript (Yan et al, 2013). In Paralichthys olivacues, it has been shown that miR-133a targets SRF mRNA (Duran et al, 2015;Su et al, 2015) as in mammals. Recently, we published a miRNA repertoire of a wide variety of tissue that identifies some muscle-specific miRNAs (Juanchich et al, 2016).…”