Effect of Fatty Acid Binding Protein 5 on Milk Fat Synthesis of Bovine Mammary Epithelial Cells

The fatty acid binding protein 5 (FABP5) is an intracellular lipid carrier. The TG GPO-POD assay kit and BODIPY staining methods were used to detect lipid secretion and triglyceride content,and the effect of FABP5 on SREBP-1c expression were detected by Real-time PCR and Western blotting methods. The results showed that high purity bovine mammary epithelial cells (BMECs) were successfully isolated and purified,and the eukaryotic expression vector pGCMV-IRES-EGFP-FABP5 was constructed in this experiment. Compared with the blank control group and empty vector group,the lipid secretion and triglyceride content, and the expression of SREBP-1c and FAS,ACC were extremely significantly increased when the FABP5 was overexpressed (P<0.01). FABP5 siRNA1 was selected as the optimal interference fragment, and when FABP5 was inhibited,the lipid secretion and triglyceride content,the expression of SREBP-1c,FAS and ACC were extremely significantly decreased (P<0.01).The results indicated that FABP5 could promote the synthesis of milk fat in BMEC by up-regulating the expression of SREBP-1c.