Wnt antagonist, secreted frizzled-related protein 1, is involved in prenatal skeletal muscle development and is a target of miRNA-1/206 in pigs

Yalan Yang, Wei Sun, Ruiqi Wang, Chuzhao Lei, Rong Zhou, Zhonglin Tang, Kui Li

The Wnt signaling pathway is involved in the control of cell proliferation and differentiation during skeletal muscle development. Secreted frizzled-related proteins (SFRPs), such as SFRP1, function as inhibitors of Wnt signaling. MicroRNA-1/206(miRNA-1/206) is specifically expressed in skeletal muscle and play a critical role in myogenesis. The miRNA-mRNA profiles and bioinformatics study suggested that the SFRP1 gene was potentially regulated by miRNA-1/206 during porcine skeletal muscle development. To understand the function of SFRP1 and miRNA-1/206 in swine myogenesis, we first predicted the targets of miRNA-1/206 with the TargetScan and PicTar programs, and analyzed the molecular characterization of the porcine SFRP1 gene. We performed a temporal-spatial expression analysis of SFRP1 mRNA and miRNA-206 in Tongcheng pigs (a Chinese indigenous breed) by quantitative real-time polymerase chain reaction, and conducted the co-expression analyses of SFRP1 and miRNA-1/206. Subsequently, the interaction between SFRP1 and miRNA-1/206 was validated via dual luciferase and Western blot assays. The bioinformatics analysis predicted SFRP1 to be a target of miRNA-1/206. The expression level of the SFRP1 was highly varied across numerous pig tissues and it was down-regulated during porcine skeletal muscle development. The expression level of the SFRP1 was significantly higher in the embryonic skeletal compared with postnatal skeletal muscle, whereas miR-206 showed the inverse pattern of expression. A significant negative correlation was observed between the expression of miR-1/206 and SFRP1 during porcine skeletal muscle development (p <0.05). Dual luciferase assay and Western-blot results demonstrated that SFRP1 was a target of miR-1/206 in porcine iliac endothelial cells. Our results indicate that the SFRP1 gene is regulated by miR-1/206 and potentially affects skeletal muscle development. These findings increase understanding of the biological functions and the regulation of the SFRP1 gene in mammals.