TRIB3 often acts as a negative regulator of lipid metabolism in the body, however, little is known about the effect of TRIB3 on milk lipid metabolism in YMECs. Therefore, we investigated the functional role of TRIB3 in lipid metabolism in vitro by transfecting YMECs with an overexpression vector and an interference vector. The results showed that after overexpression of TRIB3 , the mRNA expression levels of 10 genes related to milk fat metabolism in YMECs were very significantly downregulated ( p 0.01), the total triglyceride content was very significantly decreased ( p 0.001), lipid droplet accumulation was reduced, and the protein expression level of p -Akt was very significantly decreased ( p 0.01). The downregulation of the above protein levels was weakened by the addition of the Akt phosphorylation agonist SC76. After interference with TRIB3 , the expression levels of 9 genes related to milk fat metabolism in YMECs were very significantly upregulated ( p 0.01), the total triglyceride content was very significantly increased ( p 0.01), lipid droplet accumulation was increased, and the protein expression levels of p-Akt ( p 0.01), PPARg ( p 0.05) and p-mTOR ( p 0.01) were very significantly upregulated. The upregulation of the above protein levels was reversed by the addition the Akt phosphorylation inhibitor MK2206. These results indicated that the TRIB3 gene negatively regulates lipid synthesis in YMECs. TRIB3 affects lipid metabolism by inhibiting Akt phosphorylation, which lays a theoretical foundation for further studies on lipid metabolism in YMECs and for improving yak milk quality.
Zheng et al. (Tue,) studied this question.