miR-17-3p Regulates Preadipocyte Differentiation by Targeting KCTD15 in Yanbian Yellow Cattle

The aim of this study was to explore whether miR-17-3p could target KCTD15 to regulate the preadipocytes differentiation of Yanbian Yellow cattle. Bioinformatics softwares were used to identify homology and predict target genes of miR-17-3p. miR-17-3p mimic or miR-17-3p inhibitor and their negative control were transfected into bovine preadipocytes to overexpress or inhibit the expression of miR-17-3p. The binding sites of miR-17-3p to KCTD15 were verified via double luciferase report system. qRT-PCR and Western blot were used to detect the effect of miR-17-3p on the expressions of PPARγ, C/EBPα and KCTD15 both at mRNA and protein levels. Bioinformatics software prediction showed that KCTD15 was the target gene of miR-17-3p, and miR-17-3p had high homology in mammals. The mRNA and protein expressions of adipogenic marker genes PPARγ and C/EBPα after transfection of miR-17-3p mimic were significantly or extremely significantly higher than those of the control group transfected with NC-mimic (P<0.05 or P<0.01). After the expression of miR-17-3p was inhibited, the expressions of PPARγ and C/EBPα were significantly or extremely significantly lower than that in the control group (P<0.05 or P<0.01). Through the dual-luciferase reporter assay verification, the overexpression of miR-17-3p extremely significantly inhibited the fluorescent activity of the luciferase reporter gene vector containing the 3'UTR fragment of KCTD15 (P<0.01). Overexpression of miR-17-3p could also significantly or extremely significantly inhibit the expression of KCTD15 mRNA and protein(P<0.05 or P<0.01). However, inhibition of miR-17-3p expression could significantly increase the expression of KCTD15 mRNA and protein(P<0.05). These results suggest that miR-17-3p may regulate the differentiation of preadipocytes in Yanbian Yellow cattle by inhibiting the expression of KCTD15.