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′ untranslated region of somatostatin receptor 5 (SSTR5). 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). The 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.