Sustained upregulation of stearoyl-CoA desaturase in bovine mammary tissue with contrasting changes in milk fat synthesis and lipogenic gene networks caused by lipid supplements
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Long-term mammary expression patterns of lipogenic gene networks due to dietary lipid remain largely unknown. Mammary tissue was biopsied for transcript profiling of 29 genes at 0, 7, and 21 days of feeding cows saturated lipid (EB100) or a blend of fish/soybean oil (FSO) to depress milk fat. Milk fat yield decreased gradually with FSO and coincided with lower molar yield of fatty acids synthesized de novo, stearic acid, and oleic acid. The PPARγ targets LPIN1 and SREBF1 along with ACSS2, ACACA, FASN, and LPL increased by day 7 of feeding EB100, but differences between diets disappeared by day 21. Expression of SCAP increased markedly over time with FSO and differed from EB100 by approximately sevenfold on day 21. Expression of THRSP decreased by day 7 with both diets and returned to basal levels by day 21. SCD expression increased linearly through 7 days and remained elevated with both diets, a likely mechanism to ensure the proper level of endogenous oleic acid via desaturation of dietary stearate (EB100) or via more SCD protein to account for the reduction in stearate supply from the rumen (FSO). Despite this response, endogenous oleate was insufficient to restore normal milk fat synthesis. Only 2 of 29 genes differed in expression between diets on day 21, suggesting that transcriptional control mechanisms regulating fat synthesis were established as early as 7 days post-feeding. Gene expression reflected vastly different physiological responses by mammary tissue to adjust its metabolism to the influx of saturated fatty acids, trans10-18:1, and/or to the lack of stearic acid.
KeywordsMammary tissue Milk fat Lactation
Supported by the Cooperative State Research, Education, and Extension Service, USDA, under Hatch projects ILLU-538-307 and ILLU-538-391 (both to JJL). We gratefully acknowledge the input and help of Dr. Massimo Bionaz (University of Illinois, Urbana) during the development of the manuscript. The fish oil used in this study was donated by Omega Protein and the soybean oil by Archer Daniels Midland (Decatur, IL, USA). EnergyBooster 100 was a gift from Milk Specialties Inc. (Dundee, IL, USA). We are also grateful for the help from the staff of the University of Illinois Dairy Research and Teaching Unit for animal care.
Integrity of research and reporting
The authors declare that the experiment complies with the current laws of the USA. The authors declare no conflicts of interest.
- Invernizzi G, Thering BJ, Bionaz M, Graugnard D, Piantoni P, Everts RE, Lewin HA, Savoini G, Loor JJ (2009) New insights on mammary tissue responses to dietary lipids using transcriptomics. Proceedings of the XIth International Symposium on Ruminant Physiology, Clermont-Ferrand, France, September 6–9, pp 540–542Google Scholar
- Kast-Woelbern HR, Dana SL, Cesario RM, Sun L, de Grandpre LY, Brooks ME, Osburn DL, Reifel-Miller A, Klausing K, Leibowitz MD (2004) Rosiglitazone induction of insig-1 in white adipose tissue reveals a novel interplay of peroxisome proliferator-activated receptor gamma and sterol regulatory element-binding protein in the regulation of adipogenesis. J Biol Chem 279:23908–23915CrossRefPubMedGoogle Scholar
- Loor JJ, Doreau M, Chardigny JM, Ollier A, Sebedio JL, Chilliard Y (2005a) Effects of ruminal or duodenal supply of fish oil on milk fat secretion and profiles of trans-fatty acids and conjugated linoleic acid isomers in dairy cows fed maize silage. Anim Feed Sci Technol 119:227–246CrossRefGoogle Scholar
- Loor JJ, Ueda K, Ferlay A, Chilliard Y, Doreau M (2005b) Intestinal flow and digestibility of trans fatty acids and conjugated linoleic acids (CLA) in dairy cows fed a high-concentrate diet supplemented with fish oil, linseed oil, or sunflower oil. Anim Feed Sci Technol 119:203–225CrossRefGoogle Scholar
- Miyazaki M, Dobrzyn A, Man WC, Chu K, Sampath H, Kim HJ, Ntambi JM (2004) Stearoyl-CoA desaturase 1 gene expression is necessary for fructose-mediated induction of lipogenic gene expression by sterol regulatory element-binding protein-1c-dependent and -independent mechanisms. J Biol Chem 279:25164–71CrossRefPubMedGoogle Scholar
- Offer NW, Marsden M, Phipps RH (2001) Effect of oil supplementation of a diet containing a high concentration of starch on levels of trans fatty acids and conjugated linoleic acids in bovine milk. Anim Sci 73:533–540Google Scholar
- Shingfield KJ, Bernard L, Leroux C, Chilliard Y (2010) Role of trans fatty acids in the nutritional regulation of mammary lipogenesis in ruminants. Animal 4:1140–1166Google Scholar
- Verheijen MH, Camargo N, Verdier V, Nadra K, de Preux Charles AS, Médard JJ, Luoma A, Crowther M, Inouye H, Shimano H, Chen S, Brouwers JF, Helms JB, Feltri ML, Wrabetz L, Kirschner D, Chrast R, Smit AB (2009) SCAP is required for timely and proper myelin membrane synthesis. Proc Natl Acad Sci U S A 106:21383–8CrossRefPubMedGoogle Scholar