Oar-miR-432 Regulates Fat Differentiation and Promotes the Expression of BMP2 in Ovine Preadipocytes

Abstract

The fat tail is a unique characteristic of sheep that represents energy reserves and is a complex adaptative mechanism of fat-tailed sheep to environmental stress. MicroRNA plays a significant role as regulators at the posttranscriptional level, but no studies have explained the molecular mechanisms of miRNA which regulate fat deposition in sheep tails. In this study, mRNA and miRNA analysis examined tail fat tissue from three Hu fat-tailed and three Tibetan thin-tailed sheep. After aligning to the reference sequences, 2,108 differentially expressed genes and 105 differential expression miRNAs were identified, including 1,247 up- and 861 downregulated genes and 43 up- and 62 downregulated miRNAs. Among these differentially expressed miRNAs, oar-miR-432 was one of the most downregulated miRNAs between Hu sheep and Tibetan sheep, and 712 genes were predicted to be targeted by oar-miR-432, 80 of which overlapped with DEGs. The Gene Ontology analysis on these genes showed that BMP2, LEP, GRK5, BMP7, and RORC were enriched in fat cell differentiation terms. The genes for BMP2 targeted by oar-miR-432 were examined using dual-luciferase assay. The oar-miR-432 mimic transfected into preadipocytes resulted in increased expression of BMP2. The marker gene PPAR-γ of fat differentiation had a lower expression than the negative control on days 0, 2, and 4 after induced differentiation. The decrease in the number of lipids in the oar-miR-432 mimic group detected by oil red O stain was also less than that in the negative control. This is the first study to reveal the fat mechanisms by which oar-miR-432 inhibits fat differentiation and promotes the expression of BMP2 in sheep tails.

Whole-body adipose tissue multi-omic analyses in sheep reveal molecular mechanisms underlying local adaptation to extreme environments

“…For example, candidate genes PDGFD, BMP2, TBXT, and HOXB13 were detected by selective sweep or GWAS analysis 15,[18][19][20][21][22] , which are involved in preadipocyte differentiation and associated with fat deposition in sheep 5,23 . In addition, many candidate genes, microRNA and lncRNA were identified by transcriptomic and proteomic approaches, such as PGDFD, BMP2, IL6, ADIPOQ, miR-432, most of which are related to fat deposition and lipid metabolism [24][25][26][27][28] . Those studies revealed plenty of candidate genes and regulatory elements associated with the fat tail phenotype and suggested a complex genetic mechanism for the fat tail phenotype.…”

MiRNA-Seq reveals key MicroRNAs involved in fat metabolism of sheep liver

“…Then we detected the expression of oar-miR-432 and SIRT1 . The expression of oar-miR-432 was increased by oar-miR-432 mimics ( Jin et al, 2022 ). The result of the Western blot showed the expression of SIRT1 was inhibited by oar-miR-432 mimics ( Figures 3C,D , Supplementary Table S11 , Supplementary Figure S2 , Supplementary Figure S3 ).…”

“…Sheep preadipocytes were isolated from the tail fat of a 70-day-old Hu sheep fetus by collagenase digestion. Preadipocyte transfection and culture were according to our previous method ( Jin et al, 2022 ). When the cell showed contact inhibition, we collected cells and extracted protein.…”

Genetics of the phenotypic evolution in sheep: a molecular look at diversity-driving genes

“…Table S3. Sheep tails from a transcriptomic perspective: microRNA profiles [242][243][244][245][246][247][248][249][250][251][252][253][254]. Table S4.…”