Molecular and expression characteristics of resistin (RETN) and its effects on the differentiation of intramuscular preadipocyte in goat

Abstract

Resistin (RETN) is a hormone secreted by adipocytes, which plays an important role in glucose and lipid metabolism. The aim of this study is to clone and obtain the full length open reading frame (ORF) of goat RETN gene sequence, and to reveal its molecular and expression characteristics. Simultaneously, we explore its effect on the differentiation of intramuscular preadipocytes in goat. The full length ORF sequence of goat RETN gene was cloned by RT-PCR technique, and bioinformatics analysis was performed though relevant biological softwares. In this study, the expression of RETN mRNA in goat tissues and intramuscular preadipocytes during differentiation was detected by qPCR technique. Furthermore, RNA interference was used to explore the effects of RETN on intramuscular preadipocytes differentiation in goat. The results showed that the cloned goat RETN gene sequence was 428 bp in length, of which the ORF was 330 bp, encoding 109 amino acids. Sequence analysis revealed that it had 12 phosphorylation sites and an O-glycosylation site, and its protein contained a signal peptide sequence. Also, the RETN gene is expressed in goat various analyzed tissues, and the results showed that the expression of RETN gene in lung tissue was higher than that in other analyzed tissues of goat (p < .01). Moreover, the expression level of RETN gene in the goat's intramuscular preadipocytes decreased first and then increased, and reached the highest on the fifth day, which was significantly higher than that of undifferentiated intramuscular preadipocytes (p < .001). After transfecting intramuscular preadipocyte with siRNA, we found that the mRNA level of RETN was significantly down-regulated by 70% and 87% (p < .01). Oil red O staining results showed that the interference of RETN gene can promote the differentiation of intramuscular preadipocytes. After knockdown of RETN with siRNA, the PPARγ, AP2, C/EBPα, C/EBPβ and SREBP1 genes were significantly up-regulated (p < .01). Thus, it can be inferred that RETN inhibits the differentiation of goat intramuscular preadipocytes, probably through regulating the expression of C/EBPα, C/EBPβ, PPARγ, AP2 and SREBP-1 genes.