Abstract
Noncoding RNAs, such as long noncoding RNAs (lncRNAs), are abundant in livestock. Many lncRNAs that affect the growth rate of livestock have been identified in muscles. However, some of their physiological functions and regulatory mechanisms remain unclear. In this study, we identified a new lncRNA (lncPRRX1) and investigated its effect on the proliferation of bovine myoblasts. LncPRRX1 was highly expressed in muscle tissue, and interference with lncPRRX1 inhibited the proliferation of bovine myoblasts in vitro. The RNA molecules of lncPRRX1 act on miR-137 as competitive endogenous RNAs (ceRNAs). Overexpression of miR-137 suppressed the proliferation of myoblasts, while inhibition of miR-137 had the opposite effect. In addition, the predicted target genes of miR-137 were significantly enriched in the mitogen-activated protein kinase (MAPK) signaling pathway, in which Cell Division Cycle 42 (CDC42) was shown to be the direct target gene of miR-137, and interference with CDC42 inhibited myoblast proliferation. Furthermore, interference with lncPRRX1 repaired the defects in CDC42 protein levels and cell proliferation caused by miR-137 inhibitors. Our results suggested that lncPRRX1 promoted bovine myoblast proliferation by regulating the miRNA-137/CDC42 axis.