Effect of CLA and Other C18 Unsaturated Fatty Acids on DGAT in Bovine Milk Fat Biosynthetic Systems

Sorensen, Brent; Kazala, E. Chris; Murdoch, Gordon K.; Keating, Aileen F.; Cruz‐Hernandez, Cristina; Wegner, J.; Kennelly, J. J.; Okine, E. K.; Weselake, Randall J.

doi:10.1007/s11745-008-3216-z

Cited by 24 publications

(22 citation statements)

References 53 publications

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“…The two known DGATs, DGAT1 and DGAT2, share little if any, similar sequences despite their similar enzymatic properties in in vitro assays (Cases et al 2001). Coincidently, in the present experiment, treatment with trans10, cis12 CLA elevated the expression of DGAT2 but not DGAT1, which was in agreement with Sørensen et al (2008). Coincidently, in the present experiment, treatment with trans10, cis12 CLA elevated the expression of DGAT2 but not DGAT1, which was in agreement with Sørensen et al (2008).…”

Section: Figuresupporting

confidence: 74%

High‐level exogenous trans10, cis12 conjugated linoleic acid plays an anti‐lipogenesis role in bovine mammary epithelial cells

Wang

Liu

et al. 2014

Animal Science Journal

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Primary bovine mammary epithelial cells (BMECs) were treated by 0, 37.5, 75, 112.5, 150 μmol/L trans10, cis12 conjugated linoleic acid (CLA) to evaluate the effects of different level trans10, cis12 CLA on lipogenesis in BMEC. Addition of 75-150 μmol/L trans10, cis12 CLA reduced significantly the triacylglycerol (TAG) content (P<0.05), but did not have inhibiting action on cell proliferation (P>0.05). Treatment with 150 μmol/L trans10, cis12 CLA for 48 h resulted in a 17.1% reduction (P<0.0001) of medium chain fatty acids (MCFA, C14

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Section: Figuresupporting

confidence: 74%

High‐level exogenous trans10, cis12 conjugated linoleic acid plays an anti‐lipogenesis role in bovine mammary epithelial cells

Wang

Liu

et al. 2014

Animal Science Journal

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“…However, studies based on incubations with MAC-T (Kadegowda et al, 2009) and BME-UV (McFadden et al, 2008) have reported that trans-10, cis-12 CLA decreases SREBP1 gene expression. Further investigations with MAC-T cells have shown that trans-10, cis-12 CLA has no effect on DGAT1 transcription, increases DGAT2 and LPAAT expression and decreases DGAT activity (Sorensen et al, 2009).…”

Section: Future Perspectivesmentioning

confidence: 95%

Role of trans fatty acids in the nutritional regulation of mammary lipogenesis in ruminants

Shingfield

Bernard

Leroux

et al. 2010

Animal

336

427

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Fat is an important constituent contributing to the organoleptic, processing and physical properties of ruminant milk. Understanding the regulation of milk fat synthesis is central to the development of nutritional strategies to enhance the nutritional value of milk, decrease milk energy secretion and improve the energy balance of lactating ruminants. Nutrition is the major environmental factor regulating the concentration and composition of fat in ruminant milk. Feeding low-fibre/high-starch diets and/or lipid supplements rich in polyunsaturated fatty acids induce milk fat depression (MFD) in the bovine, typically increase milk fat secretion in the caprine, whereas limited data in sheep suggest that the responses are more similar to the goat than the cow. Following the observation that reductions in milk fat synthesis during diet-induced MFD are associated with increases in the concentration of specific trans fatty acids in milk, the biohydrogenation theory of MFD was proposed, which attributes the causal mechanism to altered ruminal lipid metabolism leading to increased formation of specific biohydrogenation intermediates that exert anti-lipogenic effects. Trans-10, cis-12 conjugated linoleic acid (CLA) is the only biohydrogenation intermediate to have been infused at the abomasum over a range of experimental doses (1.25 to 14.0 g/day) and shown unequivocally to inhibit milk fat synthesis in ruminants. However, increases in ruminal trans-10, cis-12 CLA formation do not explain entirely diet-induced MFD, suggesting that other biohydrogenation intermediates and/or other mechanisms may also be involved. Experiments involving abomasal infusions (g/day) in lactating cows have provided evidence that cis-10, trans-12 CLA (1.2), trans-9, cis-11 CLA (5.0) and trans-10 18:1 (92.1) may also exert anti-lipogenic effects. Use of molecular-based approaches have demonstrated that mammary abundance of transcripts encoding for key lipogenic genes are reduced during MFD in the bovine, changes that are accompanied by decrease in sterol response element binding protein 1 (SREBP1) and alterations in the expression of genes related to the SREBP1 pathway. Recent studies indicate that transcription of one or more adipogenic genes is increased in subcutaneous adipose tissue in cows during acute or chronic MFD. Feeding diets of similar composition do not induce MFD or substantially alter mammary lipogenic gene expression in the goat. The available data suggests that variation in mammary fatty acid secretion and lipogenic responses to changes in diet composition between ruminants reflect inherent interspecies differences in ruminal lipid metabolism and mammary specific regulation of cellular processes and key lipogenic enzymes involved in the synthesis of milk fat triacylglycerides.Keywords: milk fat, trans fatty acids, gene expression, lipogenesis, ruminants ImplicationsUnderstanding the regulation of milk fat synthesis is central to the development of nutritional strategies to enhance the nutritional value of milk, decrease milk-energ...

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“…These cells have been cultured and assayed for various purposes in many laboratories (e.g. Sørensen et al, 2008;Ma and Corl, 2012). Cells were cultured in DMEM/F-12 supplemented with 10% (v/v) FBS and 1% penicillin/streptomycin (5000 units of penicillin and 5000 mg of streptomycin per ml) at 378C in a humidified atmosphere of 5% CO 2 .…”

Section: Reagentsmentioning

confidence: 99%

“…This lactogenic media was refreshed after 24 h and cells were cultured for 48 h at 378C in the lactogenic media before treatment with FA. Before addition to the MAC-T cells, and as the major proportion of LCFA in blood serum of dairy cattle is tightly bound to albumin, the LCFA were complexed with BSA as sodium salts as described by Sørensen et al (2008) with some modifications. First, 0.1 mM LCFA was dissolved in 1 ml hexane : isopropanol (3 : 2) followed by addition of 10 ml 0.1 M sodium hydroxide.…”

Section: Reagentsmentioning

confidence: 99%

Effects of short- and long-chain fatty acids on the expression of stearoyl-CoA desaturase and other lipogenic genes in bovine mammary epithelial cells

Jacobs

Dijkstra

Liesman

et al. 2013

Animal

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Stearoyl-CoA desaturase (SCD) in the bovine mammary gland introduces a cis-double bond at the D9 position in a wide range of fatty acids (FA). Several long-chain polyunsaturated fatty acids (PUFA) inhibit expression of SCD, but information on the effect of short-chain fatty acids on mammary SCD expression is scarce. We used a bovine mammary cell line (MAC-T) to assess the effect of acetic acid (Ac) and b-hydroxybutyric acid (BHBA) in comparison with the effect of various long-chain fatty acids on the mRNA expression of the lipogenic enzymes SCD, acetyl-CoA carboxylase (ACACA), fatty acid synthase (FASN) and their associated gene regulatory proteins sterol regulatory element binding transcription factor 1 (SREBF1), insulin-induced gene 1 protein (INSIG1) and peroxisome proliferator-activated receptor alpha (PPARA)and peroxisome proliferator-activated receptor delta (PPARD) by quantitative real-time PCR. MAC-T cells were treated for 12 h without FA additions (CON) or with either 5 mM Ac, 5 mM BHBA, a combination of 5 mM Ac 1 5 mM BHBA, 100 mM C16:0, 100 mM C18:0, 100 mM C18:1 cis-9, 100 mM C18:1 trans-11, 100 mM C18:2 cis-9,12 or 100 mM C18:3 cis-9,12,15. Compared with control, mRNA expression of SCD1 was increased by Ac (161%) and reduced by C18:1 cis-9 (261%), C18:2 cis-9,12 (284%) and C18:3 cis-9,12,15 (288%). In contrast to native bovine mammary gland tissue, MAC-T cells did not express SCD5. Expression of ACACA was increased by Ac (144%) and reduced by C18:2 cis-9,12 (248%) and C18:3 cis-9,12,15 (249%). Compared with control, FASN expression was not significantly affected by the treatments. The mRNA level of SREBF1 was not affected by Ac or BHBA, but was reduced by C18:1 cis-9 (244%), C18:1 trans-11 (242%), C18:2 cis-9,12 (262%) and C18:3 cis-9,12,15 (268%) compared with control. Expression of INSIG1 was downregulated by C18:0 (237%), C18:1 cis-9 (263%), C18:1 trans-11 (253%), C18:2 cis-9,12 (281%) and C18:3 cis-9,12,15 (291%). Both PPARA and PPARD expression were not significantly affected by the treatments. Our results show that Ac upregulated mRNA expression of SCD1 and ACACA in MAC-T cells. The opposite effect of the PUFA C18:2 cis-9,12 and C18:3 cis-9,12,15 on the these genes and the failure of Ac to mimic the PUFA-inhibited SREBF1 and INSIG1 mRNA expression, suggest that Ac can stimulate mammary lipogenesis via a transcriptional regulatory mechanism different from PUFA.

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Effect of CLA and Other C18 Unsaturated Fatty Acids on DGAT in Bovine Milk Fat Biosynthetic Systems

Cited by 24 publications

References 53 publications

High‐level exogenous trans10, cis12 conjugated linoleic acid plays an anti‐lipogenesis role in bovine mammary epithelial cells

High‐level exogenous trans10, cis12 conjugated linoleic acid plays an anti‐lipogenesis role in bovine mammary epithelial cells

Role of trans fatty acids in the nutritional regulation of mammary lipogenesis in ruminants

Effects of short- and long-chain fatty acids on the expression of stearoyl-CoA desaturase and other lipogenic genes in bovine mammary epithelial cells

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