scholarly journals Transcriptional regulation of lipid synthesis in bovine mammary epithelial cells by sterol regulatory element binding protein-1

2012 ◽  
Vol 95 (7) ◽  
pp. 3743-3755 ◽  
Author(s):  
L. Ma ◽  
B.A. Corl
2015 ◽  
Vol 37 (6) ◽  
pp. 2115-2124 ◽  
Author(s):  
Min Zhang ◽  
Shiqi Zhang ◽  
Qi Hui ◽  
Lin Lei ◽  
Xiliang Du ◽  
...  

Background/Aims: In dairy cows, β-hydroxybutyrate (BHBA) is utilized as precursors of de novo synthesized fatty acids in mammary gland. Ketotic cows are characterized by excessive negative energy balance (NEB), which can further increase the blood BHBA concentration. Sterol regulatory element-binding protein1 (SREBP1) and cell death-inducing DNA fragmentation factor-alpha-like effector α (Cidea) play crucial roles in lipid synthesis. Therefore, we hypothesized that BHBA could stimulate SREBP1/Cidea pathway to increase milk fat synthesis in bovine mammary epithelial cells. Methods: Bovine mammary epithelial cells were treated with different concentrations of BHBA and transfected with adenovirus to silence SREBP1 expression. The effects of BHBA on the lipid synthesis in bovine mammary epithelial cells were investigated. Results: The results showed that BHBA could significantly increase the expression of SREBP1, fatty acid synthase (FAS), acetyl-CoA carboxylase α (ACC-α), Cidea and diacylglycerol transferase-1 (DGAT-1), as well as the triglycerides (TG) content in bovine mammary epithelial cells. BHBA treatment also increased the transfer of mature SREBP1 to nucleus compared with control group. However, SREBP1 silencing could significantly down-regulate the overexpression of FAS, ACC-α, Cidea and DGAT-1, as well as TG content induced by BHBA. Conclusion: The present data indicate that BHBA can significantly increase TG secretion mediated by SREBP1 in bovine mammary epithelial cells.


Biology ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 1226
Author(s):  
Yujia Jing ◽  
Yifei Chen ◽  
Shan Wang ◽  
Jialiang Ouyang ◽  
Liangyu Hu ◽  
...  

PER2, a circadian clock gene, is associated with mammary gland development and lipid synthesis in rodents, partly via regulating peroxisome proliferator-activated receptor gamma (PPARG). Whether such a type of molecular link existed in bovines was unclear. We hypothesized that PER2 was associated with lipid metabolism and regulated cell cycles and apoptosis in bovine mammary epithelial cells (BMECs). To test this hypothesis, BMECs isolated from three mid-lactation (average 110 d postpartum) cows were used. The transient transfection of small interfering RNA (siRNA) was used to inhibit PER2 transcription in primary BMECs. The silencing of PER2 led to lower concentrations of cellular lipid droplets and triacylglycerol along with the downregulation of lipogenic-related genes such as ACACA, FASN, LPIN1, and SCD, suggesting an overall inhibition of lipogenesis and desaturation. The downregulation of PPARG and SREBF1 in response to PER2 silencing underscored the importance of circadian clock signaling and the transcriptional regulation of lipogenesis. Although the proliferation of BMECs was not influenced by PER2 silencing, the number of cells in the G2/GM phase was upregulated. PER2 silencing did not affect cell apoptosis. Overall, the data provided evidence that PER2 participated in the coordination of mammary lipid metabolism and was potentially a component of the control of lipid droplets and TAG synthesis in ruminant mammary cells. The present data suggested that such an effect could occur through direct effects on transcriptional regulators.


1996 ◽  
Vol 271 (43) ◽  
pp. 26461-26464 ◽  
Author(s):  
Ryuichiro Sato ◽  
Jun Inoue ◽  
Yoshiki Kawabe ◽  
Tatsuhiko Kodama ◽  
Tatsuya Takano ◽  
...  

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