scholarly journals GosB Inhibits Triacylglycerol Synthesis and Promotes Cell Survival in Mouse Mammary Epithelial Cells

2017 ◽  
Vol 2017 ◽  
pp. 1-12
Author(s):  
Gaoxiao Xu ◽  
Saixing Duan ◽  
Jianye Hou ◽  
Zhongxin Wei ◽  
Guangwei Zhao
Keyword(s):  
Fatty Acid ◽  
Epithelial Cells ◽  
Milk Fat ◽  
Fatty Acid Synthase ◽  
Mammary Epithelial Cells ◽  
Mammary Glands ◽  
Mammary Epithelial ◽  
Milk Fatty Acid ◽  
Fatty Acid Binding ◽  
Triacylglycerol Synthesis

It has been demonstrated that the activator protein related transcription factor Finkel-Biskis-Jinkins murine osteosarcoma B (GosB) is involved in preadipocyte differentiation and triacylglycerol synthesis. However, the role of GosB in regulating the synthesis of milk fatty acid in mouse mammary glands remains unclear. This research uncovered potentially new roles of GosB in suppressing milk fatty acid synthesis. Results revealed that GosB had the highest expression in lung tissue and showed a higher expression level during nonlactation than during lactation. GosB inhibited the expression of fatty acid synthase (FASN), stearoyl-CoA desaturase (SCD), fatty acid binding protein 4 (FABP4), diacylglycerol acyltransferase 1 (DGAT1), perilipin 2 (PLIN2), perilipin 3 (PLIN3), and C/EBPα in mouse mammary gland epithelial cells (MEC). In addition, GosB reduced cellular triglyceride content and the accumulation of lipid droplets; in particular, GosB enhanced saturated fatty acid concentration (C16:0 and C18:0). The PPARγ agonist, rosiglitazone (ROSI), promoted apoptosis and inhibited cell proliferation. GosB increased the expression of Bcl-2 and protected MEC from ROSI-induced apoptosis. Furthermore, MECs were protected from apoptosis through the GosB regulation of intracellular calcium concentrations. These findings suggest that GosB may regulate mammary epithelial cells milk fat synthesis and apoptosis via PPARγ in mouse mammary glands.

Liver X receptor α participates in LPS-induced reduction of triglyceride synthesis in bovine mammary epithelial cells

2020 ◽  
pp. 1-7
Author(s):  
Jianfa Wang ◽  
Shuai Lian ◽  
Jun Song ◽  
Hai Wang ◽  
Xu Zhang ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Epithelial Cells ◽  
Dairy Cow ◽  
Milk Fat ◽  
Mammary Epithelial Cells ◽  
Liver X Receptor ◽  
Mammary Epithelial ◽  
Triglyceride Synthesis ◽  
Milk Fat Depression ◽  
Liver X Receptor Α

Abstract Lipopolysaccharides (LPS) could induce milk fat depression via regulating the body and blood fat metabolism. However, it is not completely clear how LPS might regulate triglyceride synthesis in dairy cow mammary epithelial cells (DCMECs). DCMECs were isolated and purified from dairy cow mammary tissue and treated with LPS. The level of triglyceride synthesis, the expression and activity of the liver X receptor α (LXRα), enzymes related to de novo fatty acid synthesis, and the expression of the fatty acid transporters were investigated. We found that LPS decreased the level of triglyceride synthesis via a down-regulation of the transcription, translation, and nuclear translocation level of the LXRα. The results also indicated that the transcription level of the LXRα target genes, sterol regulatory element binding protein 1 (SREBP1), fatty acid synthetase (FAS), acetyl-CoA carboxylase-1 (ACC1), were significantly down-regulated in DCMECs after LPS treatment. Our data may provide new insight into the mechanisms of milk fat depression caused by LPS.

scholarly journals Bta-miR-34b regulates milk fat biosynthesis by targeting mRNA decapping enzyme 1A (DCP1A) in cultured bovine mammary epithelial cells1

2019 ◽  
Vol 97 (9) ◽  
pp. 3823-3831 ◽  
Author(s):  
Yujuan Wang ◽  
Wenli Guo ◽  
Keqiong Tang ◽  
Yaning Wang ◽  
Linsen Zan ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Lipid Droplet ◽  
Milk Fat ◽  
Fatty Acid Synthase ◽  
Binding Protein ◽  
Mammary Epithelial ◽  
Luciferase Reporter ◽  
Fatty Acid Binding ◽  
Fat Synthesis ◽  
Milk Fat Synthesis

Abstract Milk fat is a main nutritional component of milk, and it has become one of the important traits of dairy cow breeding. Recently, there is increasing evidence that microRNAs (miRNA) play significant roles in the process of milk fat synthesis in the mammary gland. Primary bovine mammary epithelial cells (BMEC) were harvested from midlactation cows and cultured in DMEM/F-12 medium with 10% fetal bovine serum, 100 units/mL penicillin, 100 µg/mL streptomycin, 5 µg/mL bovine insulin, 1 µg/mL hydrocortisone, and 2 µg/mL bovine prolactin. We found that miR-34b mimic transfection in BMEC reduced the content of intracellular triacylglycerol (TAG) and lipid droplet accumulation via triacylglycerol assay and Oil Red O staining; meanwhile, overexpression of miR-34b inhibited mRNA expression of lipid metabolism-related genes such as peroxisome proliferator-activated receptor gamma (PPARγ), fatty acid synthase (FASN), fatty acid binding protein 4 (FABP4), and CCAAT enhancer binding protein alpha (C/EBPα). Whereas miR-34b inhibitor resulted in completely opposite results. Furthermore, q-PCR and western blot analysis revealed the mRNA and protein expression levels of DCP1A were downregulated in miR-34b mimic transfection group and upregulated in miR-34b inhibitor group. Moreover, luciferase reporter assays verified that DCP1A was the direct target of miR-34b and DCP1A gene silencing in BMEC-inhibited TAG accumulation and suppressed lipid droplet formation. In conclusion, these findings revealed a novel miR-34b–DCP1A axis that has a significant role in regulating milk fat synthesis and suggested that miR-34b may be used to improve the beneficial ingredients in milk.

scholarly journals Biosynthesis of medium-chain fatty acids by mammary epithelial cells from virgin rats

1983 ◽  
Vol 212 (1) ◽  
pp. 155-159 ◽  
Author(s):  
S Smith ◽  
D Pasco ◽  
S Nandi
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Epithelial Cells ◽  
Mammary Epithelial Cells ◽  
Fatty Acid Synthetase ◽  
Mammary Glands ◽  
Mammary Epithelial ◽  
Medium Chain ◽  
Medium Chain Fatty Acids ◽  
Chain Fatty Acids

Epithelial cells were isolated from the undifferentiated mammary glands of mature virgin female rats, and their lipogenic characteristics were studied. These cells synthesized predominantly medium-chain fatty acids, albeit at a low rate. In contrast, whole tissue from mammary glands of virgin rats synthesized predominantly long-chain fatty acids at a relatively higher rate, indicating that the lipogenic activity is dominated by the adipocyte component of the gland. Enzyme assays revealed that thioesterase II, the enzyme which regulates production of medium-chain fatty acids by the fatty acid synthetase, was present at a high activity in the undifferentiated mammary epithelial cells of virgin rats. Immunohistochemical studies confirmed this observation and showed that the regulatory enzyme was present exclusively in the epithelial cells lining the alveolar and ductal elements of the undifferentiated gland. This study demonstrates that the potential to elaborate tissue-specific medium-chain fatty acids is already expressed in the undifferentiated tissue of virgin rats and is not acquired as a result of the differentiation associated with the lactogenic phase of development. In this species mammary epithelial cells apparently synthesize predominantly medium-chain fatty acids at all stages of development, and only the overall rate of synthesis is increased on induction of the fatty acid synthetase during lactogenesis.

Inhibitions of FASN suppress triglyceride synthesis via the control of malonyl-CoA in goat mammary epithelial cells

2017 ◽  
Vol 57 (8) ◽  
pp. 1624 ◽  
Author(s):  
J. Luo ◽  
J. J. Zhu ◽  
Y. T. Sun ◽  
H. B. Shi ◽  
J. Li
Keyword(s):  
Fatty Acid ◽  
Epithelial Cells ◽  
Fatty Acid Synthesis ◽  
Fatty Acid Synthase ◽  
Mammary Epithelial Cells ◽  
Acid Synthesis ◽  
Mammary Epithelial ◽  
Triglyceride Synthesis ◽  
Malonyl Coa ◽  
Goat Mammary Epithelial Cells

Fatty acid synthase (FASN) is the key enzyme for de novo fatty acid synthesis from acetyl-CoA and malonyl-CoA. All the steps involved in fatty acid synthesis by FASN have been clearly defined in monogastrics and ruminants. However, there are no data on the mechanism of how FASN affects triglyceride synthesis. Inhibition of FASN in goat mammary epithelial cells by C75, a synthetic inhibitor of FASN activity, and shRNA markedly suppressed the accumulation of triglyceride in goat mammary epithelial cells. Meanwhile, C75 treatment significantly reduced the relative content of monounsaturated fatty acids (C16:1 and C18:1). Corresponding to the suppression of lipid accumulation, both of C75 and shRNA also decreased the mRNA expression of GPAM, AGPAT6 and DGAT2, all of which are related to triglyceride synthesis. The fact that treatment of malonyl-CoA decreased the expression of these genes is consistent with the results of shRNA treatment. Furthermore, the supplement of malonyl-CoA enhanced the suppression on GPAM, AGPAT6, LPIN1, DGAT1 and DGAT2. The results underscore the role of malonyl-CoA in inhibition of FASN in regulating triglyceride synthesis in goat mammary epithelial cells.

scholarly journals Transcriptome-Wide Analysis Reveals the Role of PPARγControlling the Lipid Metabolism in Goat Mammary Epithelial Cells

PPAR Research ◽  
2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Hengbo Shi ◽  
Wangsheng Zhao ◽  
Changhui Zhang ◽  
Khuram Shahzad ◽  
Jun Luo ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Lipid Metabolism ◽  
Epithelial Cells ◽  
Milk Fat ◽  
Large Scale ◽  
Mammary Epithelial Cells ◽  
Mammary Epithelial ◽  
Fatty Acid Elongation ◽  
Goat Mammary Epithelial Cells

To explore the large-scale effect of peroxisome proliferator-activated receptorγ(PPARG) in goat mammary epithelial cells (GMEC), an oligonucleotide microarray platform was used for transcriptome profiling in cells overexpressingPPARGand incubated with or without rosiglitazone (ROSI, a PPARγagonist). A total of 1143 differentially expressed genes (DEG) due to treatment were detected. The Dynamic Impact Approach (DIA) analysis uncovered the most impacted and induced pathways “fatty acid elongation in mitochondria,” “glycosaminoglycan biosynthesis-keratan sulfate,” and “pentose phosphate pathway.” The data highlights the central role ofPPARGin milk fatty acid metabolism via controlling fatty acid elongation, biosynthesis of unsaturated fatty acid, lipid formation, and lipid secretion; furthermore, its role related to carbohydrate metabolism promotes the production of intermediates required for milk fat synthesis. Analysis of upstream regulators indicated thatPPARGparticipates in multiple physiological processes via controlling or cross talking with other key transcription factors such asPPARDandNR1H3(also known as liver-X-receptor-α). This transcriptome-wide analysis represents the first attempt to better understand the biological relevance of PPARG expression in ruminant mammary cells. Overall, the data underscored the importance of PPARG in mammary lipid metabolism and transcription factor control.

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