scholarly journals β-Hydroxybutyrate Facilitates Fatty Acids Synthesis Mediated by Sterol Regulatory Element-Binding Protein1 in Bovine Mammary Epithelial Cells

2015 ◽  
Vol 37 (6) ◽  
pp. 2115-2124 ◽  
Author(s):  
Min Zhang ◽  
Shiqi Zhang ◽  
Qi Hui ◽  
Lin Lei ◽  
Xiliang Du ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Epithelial Cells ◽  
Fatty Acid Synthase ◽  
Mammary Epithelial Cells ◽  
Regulatory Element ◽  
Lipid Synthesis ◽  
Mammary Epithelial ◽  
Control Group ◽  
Bovine Mammary Epithelial Cells ◽  
Sterol Regulatory Element

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.

Transcriptional regulation of milk lipid synthesis by exogenous C16:0 and C18 fatty acids in bovine mammary epithelial cells

2018 ◽  
Vol 98 (2) ◽  
pp. 260-270 ◽  
Author(s):  
Ni Dan ◽  
Hang Zhang ◽  
Changjin Ao ◽  
Khas-Erdene
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Epithelial Cells ◽  
Mammary Epithelial Cells ◽  
Regulatory Element ◽  
Fatty Acid Synthetase ◽  
Mammary Epithelial ◽  
Lower Amount ◽  
Milk Lipid ◽  
Bovine Mammary Epithelial Cells

The objective of this study was to examine the effects of removing one fatty acid from a combination of long-chain fatty acids (LCFA) on milk lipogenesis in bovine mammary epithelial cells. The incubation concentration of LCFA was determined, and 100 μmol L−1 of C16:0, 5 μmol L−1 of C18:0, 100 μmol L−1 of cis-9 C18:1, 25 μmol L−1 of n-6 C18:2, and 1.2 μmol L−1 of n-3 C18:3 were used in the study. Treatments were C16:0, C18:0, C18:1, C18:2, and C18:3 combinations as control; control absent of C16:0 as A-C16:0; control absent of C18:0 as A-C18:0; control absent of C18:1 as A-C18:1; control absent of C18:2 as A-C18:2; control absent of C18:3 as A-C18:3. Results showed that compared with control, fatty acid synthetase expression was reduced by A-C18:0 and A-C18:1. Palmitic acid decreased expression of lipoprotein lipase. Compared with control, the expression of stearoyl-coenzyme A desaturase-1 and cluster of differentiation 36 was reduced by all treatments. Peroxisome proliferator-activated receptor-α expression was down-regulated by A-C16:0, A-C18:0, A-C18:1, and A-C18:2. Sterol regulatory element binding factor-1 was decreased when treated with A-C18:0, A-C18:1, and A-C18:2. Cells lack of 18-carbon fatty acid synthesized lower amount of intracellular triglyceride compared with control.

Octanoate stimulates cytosolic triacylglycerol accumulation and CD36 mRNA expression but inhibits Acetyl coenzyme A carboxylase activity in primary cultured bovine mammary epithelial cells

2004 ◽  
Vol 71 (4) ◽  
pp. 398-404 ◽  
Author(s):  
Tomo Yonezawa ◽  
Shinichi Yonekura ◽  
Masato Sanosaka ◽  
Akihiko Hagino ◽  
Kazuo Katoh ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Epithelial Cells ◽  
Mrna Expression ◽  
Coenzyme A ◽  
Mammary Epithelial Cells ◽  
Lipid Synthesis ◽  
Mammary Epithelial ◽  
Acetyl Coenzyme A ◽  
Bovine Mammary Epithelial Cells ◽  
Acetyl Coenzyme A Carboxylase

Mammary epithelial cells, which express and secrete leptin into milk, accumulate triacylglycerol (TAG). We examined effects on the accumulation of cytosolic TAG of addition of short- (acetate and butyrate) or medium- (octanoate) chain fatty acids to the medium bathing bovine mammary epithelial cells (bMEC). Octanoate stimulated the accumulation of TAG in a concentration-dependent manner from 1 to 10 mM and increased lipid droplet formation and mRNA expression of CD36 (a fatty acid translocase). Additionally, expression of a peroxisome proliferator activated receptor (PPAR) γ 2 protein that is a lipid-activated transcription factor, was increased by the addition of acetate or octanoate. However, leptin mRNA expression was significantly reduced by addition of acetate or butyrate. Both short- and medium-chain fatty acids inhibited acetyl coenzyme A carboxylase (ACC) activities, which is pivotal in lipid synthesis, but elevated expression of uncoupling protein 2 (UCP2) mRNA, which is important in energy expenditure. These results suggest that octanoate induces cytosolic TAG accumulation and the formation of lipid droplets, and that acetate and butyrate inhibit leptin expression and lipid synthesis in bMEC.

Effects of exogenous C18 unsaturated fatty acids on milk lipid synthesis in bovine mammary epithelial cells

2020 ◽  
Vol 87 (3) ◽  
pp. 344-348
Author(s):  
Hang Zhang ◽  
Ni Dan ◽  
Changjin Ao ◽  
Sizhen Wang ◽  
Khas Erdene ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Epithelial Cells ◽  
Unsaturated Fatty Acids ◽  
Mammary Epithelial Cells ◽  
Lipid Synthesis ◽  
Mammary Epithelial ◽  
Control Treatment ◽  
Milk Lipid ◽  
Bovine Mammary Epithelial Cells

AbstractWe determined the effects of a combination of C18 unsaturated fatty acids (C18-UFAs) consisting of oleic, linoleic, and linolenic acids on milk lipogenesis in bovine mammary epithelial cells (BMECs). By orthogonal experiments to determine cellular triacylglycerol (TAG) accumulation, a combination of 200 μmol/l C18 : 1, 50 μmol/l C18 : 2, and 2 μmol/l C18 : 3 was selected as C18-UFAs combination treatment, and culture in medium containing fatty acid-free bovine serum albumin was used as the control. The expression of genes related to milk lipid synthesis and intracellular FA composition was measured. The results showed that cytosolic TAG formation was higher under C18-UFAs treatment than under control treatment. The mRNA expression of acetyl-CoA carboxylase-α (ACACA), fatty acid synthase (FASN), and peroxisome proliferator-activated receptor gamma (PPARG) did not differ between treatments. The abundance of stearoyl-CoA desaturase (SCD) and acyl-CoA synthetase long-chain family member 1 (ACSL1) was higher, whereas that of sterol regulatory element binding transcription factor 1 (SREBF-1) was lower after C18-UFAs treatment compared to control treatment. The C16 : 0 and SFA content was decreased following C18-UFAs treatment compared to control treatment, while the cis-9 C18 : 1 and UFA content was increased. In conclusion, C18-UFAs could stimulate triglyceride accumulation, increase the cellular UFA concentration, and regulate lipogenic genes in BMECs.

scholarly journals Circadian Gene PER2 Silencing Downregulates PPARG and SREBF1 and Suppresses Lipid Synthesis in Bovine Mammary Epithelial Cells

Biology ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 1226
Author(s):  
Yujia Jing ◽  
Yifei Chen ◽  
Shan Wang ◽  
Jialiang Ouyang ◽  
Liangyu Hu ◽  
...  
Keyword(s):  
Lipid Metabolism ◽  
Epithelial Cells ◽  
Circadian Clock ◽  
Lipid Droplets ◽  
Mammary Epithelial Cells ◽  
Lipid Synthesis ◽  
Mammary Epithelial ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
Bovine Mammary Epithelial Cells

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.

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