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.

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.

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.

scholarly journals Effects of Sodium Octanoate on Innate Immune Response of Mammary Epithelial Cells duringStaphylococcus aureusInternalization

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Nayeli Alva-Murillo ◽  
Alejandra Ochoa-Zarzosa ◽  
Joel E. López-Meza
Keyword(s):  
Immune Response ◽  
Epithelial Cells ◽  
Mrna Expression ◽  
Innate Immune Response ◽  
Mammary Epithelial Cells ◽  
Short Chain Fatty Acids ◽  
Mammary Epithelial ◽  
Innate Immune ◽  
Sodium Octanoate ◽  
Bovine Mammary Epithelial Cells

Bovine mammary epithelial cells (bMECs) are capable of initiating an innate immune response to invading bacteria. Short chain fatty acids can reduceStaphylococcus aureusinternalization into bMEC, but it has not been evaluated if octanoic acid (sodium octanoate, NaO), a medium chain fatty acid (MCFA), has similar effects. In this study we determined the effect of NaO onS. aureusinternalization into bMEC and on the modulation of innate immune elements. NaO (0.25–2 mM) did not affectS. aureusgrowth and bMEC viability, but it differentially modulated bacterial internalization into bMEC, which was induced at 0.25–0.5 mM (~60%) but inhibited at 1-2 mM (~40%). Also, bMEC showed a basal expression of all the innate immune genes evaluated, which were induced byS. aureus. NaO induced BNBD4, LAP, and BNBD10 mRNA expression, but BNBD5 and TNF-αwere inhibited. Additionally, the pretreatment of bMEC with NaO inhibited the mRNA expression induction generated by bacteria which coincides with the increase in internalization; only TAP and BNDB10 showed an increase in their expression; it coincides with the greatest effect on the reduction of bacterial internalization. In conclusion, NaO exerts a dual effect onS. aureusinternalization in bMEC and modulates elements of innate immune response.

The role of native bovine α-lactalbumin in bovine mammary epithelial cell apoptosis and casein expression

2008 ◽  
Vol 75 (3) ◽  
pp. 319-325 ◽  
Author(s):  
Lisa G Riley ◽  
Peter C Wynn ◽  
Peter Williamson ◽  
Paul A Sheehy
Keyword(s):  
Epithelial Cells ◽  
Mrna Expression ◽  
Mammary Epithelial Cells ◽  
Cell Types ◽  
Mammary Epithelial ◽  
Major Influence ◽  
Expression Levels ◽  
Bovine Mammary Epithelial Cells ◽  
Epithelial Cell Apoptosis

Folding variants of α-lactalbumin (α-la) are known to induce cell death in a number of cell types, including mammary epithelial cells (MEC). The native conformation of α-la however has not been observed to exhibit this biological activity. Here we report that native bovine α-la reduced the viability of primary bovine mammary epithelial cells (BMEC) and induced caspase activity in mammospheres, which are alveolar-like structures formed by culturing primary BMEC on extracellular matrix in the presence of lactogenic hormones. These observations suggest a possible role for bovine α-la in involution and/or maintaining the luminal space in mammary alveoli during lactation. In addition, co-incubation of bovine α-la in an in-vitro mammosphere model resulted in decreased β-casein mRNA expression and increased αs1- and κ-casein mRNA expression. This differential effect on casein expression levels is unusual and raises the possibility of manipulating expression levels of individual caseins to alter dairy processing properties. Manipulation of α-la levels could be further investigated for its potential to enhance milk protein expression and/or improve lactational persistency by influencing the balance between proliferation and apoptosis of BMEC, which has a major influence on the milk-producing capacity of the mammary gland.

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