Effect of short‐chain fatty acids on triacylglycerol accumulation, lipid droplet formation and lipogenic gene expression in goat mammary epithelial cells

2015 ◽  
Vol 87 (2) ◽  
pp. 242-249 ◽  
Author(s):  
Yuting Sun ◽  
Jun Luo ◽  
Jiangjiang Zhu ◽  
Hengbo Shi ◽  
Jun Li ◽  
...  
Keyword(s):  
Gene Expression ◽  
Fatty Acids ◽  
Mammary Epithelial Cells ◽  
Short Chain Fatty Acids ◽  
Mammary Epithelial ◽  
Lipogenic Gene ◽  
Lipogenic Gene Expression ◽  
Lipid Droplet Formation ◽  
Triacylglycerol Accumulation ◽  
Goat Mammary Epithelial Cells

scholarly journals mTORC2 Regulates Lipogenic Gene Expression through PPARγ to Control Lipid Synthesis in Bovine Mammary Epithelial Cells

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Zhixin Guo ◽  
Keyu Zhao ◽  
Xue Feng ◽  
Dandan Yan ◽  
Ruiyuan Yao ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cell Proliferation ◽  
Epithelial Cells ◽  
Mammary Epithelial Cells ◽  
Critical Role ◽  
Lipid Synthesis ◽  
Mammary Epithelial ◽  
Lipogenic Gene ◽  
Bovine Mammary Epithelial Cells ◽  
Lipogenic Gene Expression

The mechanistic target of rapamycin complex 2 (mTORC2) primarily functions as an effector of insulin/PI3K signaling to regulate cell proliferation and is associated with cell metabolism. However, the function of mTORC2 in lipid metabolism is not well understood. In the present study, mTORC2 was inactivated by the ATP-competitive mTOR inhibitor AZD8055 or shRNA targeting RICTOR in primary bovine mammary epithelial cells (pBMECs). MTT assay was performed to examine the effect of AZD8055 on cell proliferation. ELISA assay and GC-MS analysis were used to determine the content of lipid. The mRNA and protein expression levels were investigated by RT/real-time PCR and western blot analysis, respectively. We found that cell proliferation, mTORC2 activation, and lipid secretion were inhibited by AZD8055. RICTOR was knocked down and mTORC2 activation was specifically attenuated by the shRNA. Compared to control cells, the expression of the transcription factor gene PPARG and the lipogenic genes LPIN1, DGAT1, ACACA, and FASN was downregulated in RICTOR silencing cells. As a result, the content of intracellular triacylglycerol (TAG), palmitic acid (PA), docosahexaenoic acid (DHA), and other 16 types of fatty acid was decreased in the treated cells; the accumulation of TAG, PA, and DHA in cell culture medium was also reduced. Overall, mTORC2 plays a critical role in regulating lipogenic gene expression, lipid synthesis, and secretion in pBMECs, and this process probably is through PPARγ. This finding provides a model by which lipogenesis is regulated in pBMECs.

scholarly journals Role of peroxisome proliferator-activated receptor-α on the synthesis of monounsaturated fatty acids in goat mammary epithelial cells

2020 ◽  
Vol 98 (3) ◽  
Author(s):  
Huibin Tian ◽  
Jun Luo ◽  
Hengbo Shi ◽  
Xiaoying Chen ◽  
Jiao Wu ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Fatty Acid Synthesis ◽  
Mammary Epithelial Cells ◽  
Acid Synthesis ◽  
Mammary Epithelial ◽  
Mrna Abundance ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
Goat Mammary Epithelial Cells

Abstract A key member of the nuclear receptor superfamily is the peroxisome proliferator-activated receptor alpha (PPARA) isoform, which in nonruminants is closely associated with fatty acid oxidation. Whether PPARA plays a role in milk fatty acid synthesis in ruminants is unknown. The main objective of the present study was to use primary goat mammary epithelial cells (GMEC) to activate PPARA via the agonist WY-14643 (WY) or to silence it via transfection of small-interfering RNA (siRNA). Three copies of the peroxisome proliferator-activated receptor response element (PPRE) contained in a luciferase reporter vector were transfected into GMEC followed by incubation with WY at 0, 10, 20, 30, 50, or 100 µM. A dose of 50 µM WY was most effective at activating PPRE without influencing PPARA mRNA abundance. Transfecting siRNA targeting PPARA decreased its mRNA abundance to 20% and protein level to 50% of basal levels. Use of WY upregulated FASN, SCD1, ACSL1, DGAT1, FABP4, and CD36 (1.1-, 1.5-, 2-, 1.4-, 1.5-, and 5-fold, respectively), but downregulated DGAT2 and PGC1A (−20% and −40%, respectively) abundance. In contrast, triacylglycerol concentration decreased and the content and desaturation index of C16:1 and C18:1 increased. Thus, activation of PPARA via WY appeared to channel fatty acids away from esterification. Knockdown of PPARA via siRNA downregulated ACACA, SCD1, AGPAT6, CD36, HSL, and SREBF1 (−43%, −67%, −16%, −56%, −26%, and −29%, respectively), but upregulated ACSL1, DGAT2, FABP3, and PGC1A (2-, 1.4-, 1.3-, and 2.5-fold, respectively) mRNA abundance. A decrease in the content and desaturation index of C16:1 and C18:1 coupled with an increase in triacylglycerol content accompanied those effects at the mRNA level. Overall, data suggest that PPARA could promote the synthesis of MUFA in GMEC through its effects on mRNA abundance of genes related to fatty acid synthesis, oxidation, transport, and triacylglycerol synthesis.

scholarly journals Influence of fatty acid diets on gene expression in rat mammary epithelial cells

2009 ◽  
Vol 38 (1) ◽  
pp. 80-88 ◽  
Author(s):  
M. Medvedovic ◽  
R. Gear ◽  
J. M. Freudenberg ◽  
J. Schneider ◽  
R. Bornschein ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cell Cycle ◽  
Fatty Acids ◽  
Fatty Acid ◽  
Epithelial Cells ◽  
Differential Expression ◽  
Mammary Epithelial Cells ◽  
Mammary Epithelial ◽  
Differentially Expressed ◽  
Cell Cycle Genes

Background: This study examines the impact of dietary fatty acids on regulation of gene expression in mammary epithelial cells before and during puberty. Methods: Diets primarily consisted of n-9 monounsaturated fatty acids (olive oil), n-6 polyunsaturated fatty acids (safflower), saturated acids (butter), and the reference AIN-93G diet (soy oil). The dietary regimen mimics the repetitive nature of fatty acid exposure in Western diets. Diet-induced changes in gene expression were examined in laser capture microdissected mammary ductal epithelial cells at day of weaning and end of puberty. PCNA immunohistochemistry analysis compared proliferation rates between diets. Results: Genes differentially expressed between each test diets and the reference diet were significantly enriched by cell cycle genes. Some of these genes were involved in activation of the cell cycle pathway or the G2/M check point pathway. Although there were some differences in the level of differential expression, all diets showed qualitatively the same pattern of differential expression compared to the reference diet. Cluster analysis identified an expanded set of cell cycle as well as immunity and sterol metabolism related clusters of differentially expressed genes. Conclusion: Fatty acid-enriched diets significantly upregulated proliferation above normal physiological levels during puberty. Higher cellular proliferation during puberty caused by enriched fatty acid diets poses a potential increase risk of mammary cancer in later life. The human homologs of 27 of 62 cell cycle rat genes are included in a human breast cancer cluster of 45 cell cycle genes, further emphasizing the importance of our findings in the rat model.

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