TRIB3 suppresses milk fatty acids metabolism by inhibiting p-AKT/PPARG signaling in goat mammary epithelial cells

Tribbles pseudokinase 3 (TRIB3) interacts with a variety of proteins and plays a key role in the regulation of glucose metabolism and glycolysis in nonruminants, but whether it has a specific role in goat mammary lipid metabolism has still been kept unknown. In this study, we observed that TRIB3 is highly expressed in the mammary tissues of lactating dairy goats. Overexpressing TRIB3 in goat mammary epithelial cells (GMECs) suppressed the mRNA expression of GPAM, DGAT1, and PLIN1, which are associated with the formation of triacylglycerol and lipid droplets (p < 0.05). The fatty acid-sensitive transcription regulator PPARG was also downregulated. Interfering TRIB3 had the opposite effect and decreased Akt phosphorylation. The TRIB3 gene influenced fatty acid composition in GMECs, and its overexpression reduced the total concentration of intracellular triacylglycerol (p < 0.01), this response was verified using BODIPY staining. Overall, these data indicated that TRIB3 suppresses milk fatty acids metabolism through inhibiting p-AKT/PPARG signaling in GMECs.