Genome-wide analysis of circular RNA-mediated ceRNA regulation in porcine skeletal muscle development.

BACKGROUND: As a diverse and abundant class of endogenous RNAs, circular RNAs (circRNAs) participate in various biological processes including cell proliferation and apoptosis. Nevertheless, few researchers have investigated the role of circRNAs in muscle development in cultivated pigs. RESULTS: In this study, we used RNA-seq to construct circRNA expression profiles in skeletal muscle of Jinfen White pigs at the age of 1, 90, and 180 days. Among the 16,990 identified circRNAs, 584 circRNAs were differentially expressed. Moreover, the enrichment analysis of DE circRNA host genes showed that they were mainly involved in muscle contraction, muscle organ development and muscle system processes, as well as AMPK and cAMP-related signal pathways. We also constructed a circRNA-miRNA-mRNA co-expression network to find key circRNAs which many involved in the regulation of porcine skeletal muscle development through the competitive endogenous RNA (ceRNA) mechanism. It is noteworthy that circ_0018595/miR-1343/PGM1 axis may play a regulatory role in the development of porcine skeletal muscle. CONCLUSIONS: This study identified the circRNAs and present the circRNA expression profile in the development of pigs, revealed that DE circRNA host genes participate in different cell fates and enriched the porcine ceRNA network. Thus, this work will become a valuable resource for further in-depth study of the regulatory mechanism of circRNA in the development of porcine skeletal muscle.

Caveolae-associated protein 3 promotes adipogenic differentiation of porcine preadipocytes by promoting extracellular signal-regulated kinase phosphorylation.

Fat deposition is one of the key factors affecting the economic development of pig husbandry. The aim of this study was to investigate the expression characteristics of caveolae-associated protein 3 (CAVIN3) and to elucidate its effect and mechanism on adipogenic differentiation of porcine preadipocytes. Cell transfection, quantitative reverse transcription polymerase chain reaction (qRT-PCR), western blot, and oil red O staining were used to detect the effect of CAVIN3 on the differentiation of porcine preadipocytes. The results showed that CAVIN3 was expressed in various tissues, with higher expression in adipose tissue, differentially expressed during cell adipogenic differentiation, and mainly distributed in the cytoplasm. Functional studies showed that, after CAVIN3 interference in preadipocytes, the expression of adipogenic factors and the content of lipid droplets were significantly decreased (p < 0.05). The results were reversed after CAVIN3 was overexpressed. The mechanism research showed that LY3214996 inhibited the extracellular signal-regulated kinase (ERK) phosphorylation and further inhibited lipogenic factors expression. Overexpression of CAVIN3 attenuates the inhibitory effect of LY3214996 on ERK phosphorylation and attenuates its inhibitory effect on adipogenic differentiation. Therefore, this study demonstrated that CAVIN3 promotes the differentiation of porcine preadipocytes by promoting ERK phosphorylation. The present study can lay a theoretical foundation for further studying the molecular mechanism of porcine fat deposition.