Abstract：
Milk fat content is a critical indicator of milk quality. Exploring the key regulatory genes involved in milk fat synthesis is essential for enhancing milk fat content. STF-62247 (STF), a thiazolamide compound, has the potential to bind with ALG5 and upregulate lipid droplets in fat synthesis. However, the effect of STF on the process of milk fat synthesis and whether it acts through ALG5 remains unknown. In this study, the impact of ALG5 on milk fat synthesis and its underlying mechanism were investigated using bovine mammary epithelial cells (BMECs) and mouse models through real-time PCR, western blotting, Oil Red O staining, and triglyceride analysis. Experimental findings revealed a positive correlation between STF and ALG5 with the ability to synthesize milk fat. Silencing ALG5 led to decreased expression of FASN, SREBP1, and PPARγ in BMECs, as well as reduced phosphorylation levels in the PI3K/AKT/mTOR signaling pathway. Moreover, the phosphorylation levels of the PI3K/AKT/mTOR signaling pathway were restored when ALG5 silencing was followed by the addition of STF. These results suggest that STF regulates fatty acid synthesis in BMECs by affecting the PI3K/AKT/mTOR signaling pathway through ALG5. ALG5 is possibly a new factor in milk fat synthesis.
摘要：
牛奶脂肪含量是牛奶质量的关键指标。探索参与乳脂合成的关键调控基因对于提高乳脂含量至关重要。STF-62247(STF),噻唑酰胺化合物，具有与ALG5结合并在脂肪合成中上调脂滴的潜力。然而,STF对乳脂合成过程的影响以及它是否通过ALG5起作用仍然未知。在这项研究中,利用奶牛乳腺上皮细胞（BMECs）和小鼠模型，通过实时PCR研究ALG5对乳脂合成的影响及其潜在机制，西方印迹,油红O染色,和甘油三酯分析。实验发现表明，STF和ALG5与合成乳脂的能力呈正相关。沉默ALG5导致FASN表达降低，BMECs中的SREBP1和PPARγ，以及降低PI3K/AKT/mTOR信号通路中的磷酸化水平。此外，ALG5沉默后加入STF,PI3K/AKT/mTOR信号通路的磷酸化水平得到恢复.这些结果表明,STF通过ALG5影响PI3K/AKT/mTOR信号通路来调节BMECs中的脂肪酸合成。ALG5可能是乳脂合成的新因子。
