The effect of miR-6523a on growth hormone secretion in pituitary cells of Yanbian yellow cattle

Abstract

Yanbian yellow cattle breeding is limited by its slow growth. We previously found that the miRNA miR-6523a is differentially expressed between Yanbian yellow cattle and Han Yan cattle, which differ in growth characteristics. In this study, we evaluated the effects of miR-6523a on growth hormone (GH) secretion in pituitary cells of Yanbian yellow cattle. Bioinformatics analyses using TargetScan and RNAhybrid as well as dual luciferase reporter assays showed that miR-6523a targets the 3' UTR of SSTR5 (somatostatin receptor 5). We further found that the mRNA and protein expression levels of GH in pituitary cells were significantly higher in cells treated with miR-6523a mimic than in the control group (P=0.0082 and P=0.0069). GH mRNA and protein expression levels were lower in cells treated with miR-6523a inhibitor than in the control group, but the difference was not significant (P=0.064 and P=0.089). SSTR5 mRNA and protein levels were inhibited by miR-6523a mimic compared with the control group) (P=0.0024 and P=0.0028) and were elevated slightly by miR-6523a inhibitor (P=0.093 and P=0.091). These results prove that miR-6523a regulates GH secretion in pituitary cells by SSTR5. More broadly, these findings provide a basis for studies of the roles of miRNAs in animal growth and development.