scholarly journals Fatty acid elongase 5 (ELOVL5) alters the synthesis of long-chain unsaturated fatty acids in goat mammary epithelial cells

2018 ◽  
Vol 101 (5) ◽  
pp. 4586-4594 ◽  
Author(s):  
H.B. Shi ◽  
Y. Du ◽  
C.H. Zhang ◽  
C. Sun ◽  
Y.L. He ◽  
...  
2019 ◽  
Vol 6 (2) ◽  
pp. 54 ◽  
Author(s):  
Einar Vargas-Bello-Pérez ◽  
Wangsheng Zhao ◽  
Massimo Bionaz ◽  
Jun Luo ◽  
Juan J. Loor

A prior study in bovine mammary (MACT) cells indicated that long-chain fatty acids (LCFA) C16:0 and C18:0, but not unsaturated LCFA, control transcription of milk fat-related genes partly via the activation of peroxisome proliferator-activated receptor gamma (PPARγ). However, in that study, the activation of PPARγ by LCFA was not demonstrated but only inferred. Prior data support a lower response of PPARγ to agonists in goat mammary cells compared to bovine mammary cells. The present study aimed to examine the hypothesis that LCFA alter the mRNA abundance of lipogenic genes in goat mammary epithelial cells (GMEC) at least in part via PPARγ. Triplicate cultures of GMEC were treated with a PPARγ agonist (rosiglitazone), a PPARγ inhibitor (GW9662), several LCFA (C16:0, C18:0, t10,c12-CLA, DHA, and EPA), or a combination of GW9662 with each LCFA. Transcription of 28 genes involved in milk fat synthesis was measured using RT-qPCR. The data indicated that a few measured genes were targets of PPARγ in GMEC (SCD1, FASN, and NR1H3) while more genes required a basal activation of PPARγ to be transcribed (e.g., LPIN1, FABP3, LPL, and PPARG). Among the tested LCFA, C16:0 had the strongest effect on upregulating transcription of measured genes followed by C18:0; however, for the latter most of the effect was via the activation of PPARγ. Unsaturated LCFA downregulated transcription of measured genes, with a lesser effect by t10,c12-CLA and a stronger effect by DHA and EPA; however, a basal activation of PPARγ was essential for the effect of t10,c12-CLA while the activation of PPARγ blocked the effect of DHA. The transcriptomic effect of EPA was independent from the activation of PPARγ. Data from the present study suggest that saturated LCFA, especially C18:0, can modulate milk fat synthesis partly via PPARγ in goats. The nutrigenomic effect of C16:0 is not via PPARγ but likely via unknown transcription factor(s) while PPARγ plays an indirect role on the nutrigenomic effect of polyunsaturated LCFA (PUFA) on milk fat related genes, particularly for CLA (permitting effect) and DHA (blocking effect).


Animals ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 389 ◽  
Author(s):  
Shi ◽  
Wang ◽  
Luo ◽  
Liu ◽  
Loor ◽  
...  

In humans, fatty acid elongase 7 (ELOVL7) plays a role in synthesis of long-chain saturated fatty acids. Whether ELOVL7 protein plays a role in ruminants is unclear. The transcript abundance of ELOVL7 in goat mammary tissue was assessed at three stages of lactation. Results showed that ELOVL7 had the highest expression in the dry period compared with peak and late lactation period. Results revealed that ELOVL7 overexpression was correlated with lower expression in diacylglycerol O-acyltransferase 2 (DGAT2) and stearoyl-CoA desaturase 1 (SCD1), and had no significant effect on triacylglycerol concentration. Overexpression of ELOVL7 significantly decreased the concentration of palmitoleic (C16:1n7) and oleic (C18:1n9) acid, and increased the concentration of vaccenic (C18:1n7) and linoleic (C18:2) acid. Overexpression of ELOVL7 significantly upregulated the elongation index of C16:1 in goat epithelial mammary cells (GMEC), but had a minor effect on that of palmitate (C16:0). Knockdown of ELOVL7 decreased mRNA expression of fatty acid binding protein 3 (FABP3) and fatty acid desaturase 2 (FADS2) and had a minor effect on triacylglycerol concentration; however, it increased concentration of C18:1n9 in GMEC. The elongation indices of C16:0 and C16:1 did not differ due to knockdown of ELOVL7. The minor change for the C16:0 and stearate (C18:0) was observed after activation of ELOVL7, suggesting the two fatty acids are not the preferential substrates of ELOVL7 in cultured GMEC. However, changes in C18:1n9 and C18:2 after overexpression or knockdown of ELOVL7 indicated a biological functional role of ELOVL7. Collectively, our data highlighted a role of ELOVL7 in long-chain unsaturated fatty acid elongation in goat mammary epithelial cells.


2020 ◽  
Vol 87 (3) ◽  
pp. 344-348
Author(s):  
Hang Zhang ◽  
Ni Dan ◽  
Changjin Ao ◽  
Sizhen Wang ◽  
Khas Erdene ◽  
...  

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.


2020 ◽  
Vol 98 (3) ◽  
Author(s):  
Huibin Tian ◽  
Jun Luo ◽  
Hengbo Shi ◽  
Xiaoying Chen ◽  
Jiao Wu ◽  
...  

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.


2009 ◽  
Vol 38 (1) ◽  
pp. 80-88 ◽  
Author(s):  
M. Medvedovic ◽  
R. Gear ◽  
J. M. Freudenberg ◽  
J. Schneider ◽  
R. Bornschein ◽  
...  

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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