Bovine Adipocyte-Derived Exosomes Transport LncRNAs to Regulate Adipogenic Transdifferentiation of Bovine Muscle...

Intramuscular fat content is a key factor in determining the quality and value of beef. Intramuscular adipocytes and satellite cells can interact with each other, and both are the source cells for intramuscular fat formation. To better understand the mechanism of bovine adipocytes regulating adipogenic transdifferentiation of muscle satellite cells (MSCs), this study established a co-culture system of bovine adipocytes and bovine MSCs, identified and isolated exosomes secreted by bovine adipocytes, co-cultured exosomes with bovine MSCs, and performed lncRNA sequencing of exosomes. The results showed that lipid droplets appeared in bovine MSCs under the co-culture system, and the expression levels of the PPARγ and CEBPA, which were lipogenesis-related genes, were significantly elevated. In addition, this study identified 3425 lncRNAs in adipocyte-derived exosomes, and the target genes of these lncRNAs were significantly enriched in gene functions and pathways related to transcriptional regulation, cellular differentiation, lipogenesis, and metabolism. It is worth noting that lncRNA-DGAT2 (lncDGAT2) can competitively bind to bta-miR-2455, increase the expression of target gene DGAT2, and promote adipogenic transdifferentiation of MSCs. In summary, bovine adipocytes can regulate the adipogenic transdifferentiation of MSCs through exosomes and exosomal lncRNAs. This study provides new insights into the regulation mechanism of bovine intramuscular fat deposition.