1
|
Li Y, Zhou H, Cheng L, Zhao J, Hickford J. Variation in the stearoyl-CoA desaturase gene ( SCD) and its influence on milk fatty acid composition in late-lactation dairy cattle grazed on pasture. Arch Anim Breed 2020; 63:355-366. [PMID: 33178884 PMCID: PMC7648274 DOI: 10.5194/aab-63-355-2020] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Accepted: 09/03/2020] [Indexed: 11/20/2022] Open
Abstract
Gene markers have become useful tools for improving animal genetics
and breeding since they improve the accuracy of selection for superior
breeding stock. In this study, the stearoyl-CoA desaturase (Δ-9-desaturase) gene (SCD) was investigated in New Zealand
pasture-grazed Holstein–Friesian × Jersey cows. Three
nucleotide substitutions were identified in exon 5 of the gene
(c.702A/G, c.762T/C and c.878C/T), and a single nucleotide substitution
was identified in intron 5 (c.880+105A/G). The c.878C/T substitution
would, if expressed, result in the amino acid substitution
p.A293V. Four nucleotide substitutions (c.*1783A/G, c.*1883C/T,
c.*1984G/A and c.*2066T/C/G) were identified in the 3′-untranslated
region (3′-UTR), and these resulted in three nucleotide sequence
variants (named a, b and c). The sequence that would encode
valine (V) at position 293 of SCD was linked to 3′-UTR variant a,
and the sequence that would encode alanine (A) was linked to variants
b and c. The frequency of the genotypes was as follows: VV (equivalent to
aa: 15.1 %), VA (equivalent to ab+ac:
50.0 %) and AA (equivalent to bb+cc+bc: 34.9 %). The cows with the V variant produced less
C10:1, C12:1 and C14:1 fatty acid (FA) but more C10:0, C11:0, C14:0,
C16:1 and C18:2 FA than the A variant cows (P<0.001). Effects of
c.*1783A/G and c.*2066T/C/G on milk fat composition were also found
for the AA cows. The presence of c was associated with decreased
levels of C16:1 (P<0.001), C17:1 (P=0.001), C18:2
cis-9, trans-13 (P=0.045), C18:2
cis-9, trans-12 (P=0.018) FA and C16:1 FA
index (P<0.001). The presence of b was associated with
increased levels of C13:0 iso FAs (P<0.001),
monounsaturated FA (MUFA; P=0.002) and C12:1 (P<0.001).
Collapse
Affiliation(s)
- Yunhai Li
- Department of Agricultural Sciences, Faculty of Agriculture and Life Sciences, Lincoln University, Lincoln 7647, New Zealand
| | - Huitong Zhou
- Department of Agricultural Sciences, Faculty of Agriculture and Life Sciences, Lincoln University, Lincoln 7647, New Zealand
| | - Long Cheng
- Faculty of Veterinary and Agricultural Sciences, Dookie College, The University of Melbourne, Victoria 3647, Australia
| | - Jenny Zhao
- Department of Agricultural Sciences, Faculty of Agriculture and Life Sciences, Lincoln University, Lincoln 7647, New Zealand
| | - Jonathan Hickford
- Department of Agricultural Sciences, Faculty of Agriculture and Life Sciences, Lincoln University, Lincoln 7647, New Zealand
| |
Collapse
|
2
|
Jin YC, Li ZH, Hong ZS, Xu CX, Han JA, Choi SH, Yin JL, Zhang QK, Lee KB, Kang SK, Song MK, Kim YJ, Kang HS, Choi YJ, Lee HG. Conjugated linoleic acid synthesis-related protein proteasome subunit α 5 (PSMA5) is increased by vaccenic acid treatment in goat mammary tissue. J Dairy Sci 2012; 95:4286-97. [PMID: 22818443 DOI: 10.3168/jds.2011-4281] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2011] [Accepted: 03/07/2012] [Indexed: 11/19/2022]
Abstract
This study was conducted to identify proteins associated with the endogenous synthesis of conjugated linoleic acid (CLA) from trans-vaccenic acid (TVA; trans-11 C18:1, a precursor for CLA endogenous synthesis) in mammary tissues. Six lactating goats were divided into 2 groups. One group was given an intravenous bolus injection of TVA (150mg) twice daily over 4 d; the other group received saline injections. Treatment with TVA increased the concentration of cis-9,trans-11 CLA and TVA in goat milk. Additionally, TVA treatment increased the expression of stearoyl-CoA desaturase (SCD) in mammary tissue. Using 2-dimensional gel electrophoresis and electrospray ionization quadrupole time-of-flight mass spectrometry, 3 proteins affected by infusions of TVA were identified. Proteasome (prosome, macropain) subunit α type 5 (PSMA5) was upregulated, whereas peroxiredoxin-1 and translationally controlled tumor protein 1 were downregulated in TVA-treated animals compared with the vehicle-injected controls. Only the effect of TVA on PSMA5 could be confirmed by Western blot analysis. To further explore the regulation of PSMA5 in mammary epithelial cells when TVA is converted into CLA, we used a differentiated bovine mammary epithelial cell line treated with TVA for 6h. Changes in cis-9,trans-11 CLA concentrations and mRNA expression patterns of both SCD and PSMA5 were monitored. The concentration of cis-9,trans-11 CLA increased after TVA treatment. The mRNA expression level of PSMA5 was significantly elevated to 6h, but SCD mRNA expression only increased in 2h after TVA treatment. These results indicate that PSMA5 is highly expressed in goat mammary tissue and bovine mammary epithelial cells when TVA is converted into CLA. Our data suggest that PSMA5 protein is associated with CLA biosynthesis in mammary tissue.
Collapse
Affiliation(s)
- Y C Jin
- Department of Animal Science, College of Animal Science and Veterinary Medicine, Jilin University, Changchun 130062, People's Republic of China
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
3
|
Jacobs AAA, Dijkstra J, Hendriks WH, van Baal J, van Vuuren AM. Comparison between stearoyl-CoA desaturase expression in milk somatic cells and in mammary tissue of lactating dairy cows. J Anim Physiol Anim Nutr (Berl) 2012; 97:353-62. [DOI: 10.1111/j.1439-0396.2012.01278.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
4
|
Jacobs A, van Baal J, Smits M, Taweel H, Hendriks W, van Vuuren A, Dijkstra J. Effects of feeding rapeseed oil, soybean oil, or linseed oil on stearoyl-CoA desaturase expression in the mammary gland of dairy cows. J Dairy Sci 2011; 94:874-87. [DOI: 10.3168/jds.2010-3511] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2010] [Accepted: 10/14/2010] [Indexed: 11/19/2022]
|
5
|
Jin YC, Lee HG, Xu CX, Han JA, Choi SH, Song MK, Kim YJ, Lee KB, Kim SK, Kang HS, Cho BW, Shin TS, Choi YJ. Proteomic analysis of endogenous conjugated linoleic acid biosynthesis in lactating rats and mouse mammary gland epithelia cells (HC11). BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2010; 1804:745-51. [DOI: 10.1016/j.bbapap.2009.11.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2009] [Revised: 11/13/2009] [Accepted: 11/18/2009] [Indexed: 10/20/2022]
|
6
|
Reh R, Ozols J, Clement B. Involvement of stearoyl-CoA desaturase in the reduction of amidoxime prodrugs. Xenobiotica 2008; 38:1177-90. [PMID: 18609446 DOI: 10.1080/00498250802109199] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
1. This study investigates the enzymatic reduction of N-hydroxylated amidines by porcine adipose tissue and the possible involvement of stearoyl-CoA desaturase (SCD). 2. The reduction of the model substrate benzamidoxime was studied with porcine adipose tissue microsomes and partially purified SCD from SCD-enriched rat liver microsomes. 3. Inhibitor studies with these microsomal preparations using various inhibitors including anti-SCD antibody, cyanide and stearoyl-CoA supported a role for SCD in the reduction of N-hydroxylated amidines in adipose tissue. The content and activity of SCD in these microsomes was established by Western blot and SCD activity determinations. Additionally, a reconstituted system of cytochrome b(5), NADH-cytochrome b(5) reductase and partially purified SCD from SCD-enriched rat liver microsomes supported benzamidoxime reductase activity that was inhibitable by an anti-SCD antibody. 4. The results support the participation of SCD in the reduction of amidoxime prodrugs and demonstrate for the first time that SCD can also accept foreign compounds (xenobiotics) as substrates.
Collapse
Affiliation(s)
- R Reh
- Institute of Pharmacy, Christian-Albrechts-University of Kiel, Kiel, Germany
| | | | | |
Collapse
|
7
|
Mosley EE, McGuire MA. Methodology for the In Vivo Measurement of the Δ9-Desaturation of Myristic, Palmitic, and Stearic Acids in Lactating Dairy Cattle. Lipids 2007; 42:939-45. [PMID: 17619092 DOI: 10.1007/s11745-007-3085-x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2007] [Accepted: 06/07/2007] [Indexed: 10/23/2022]
Abstract
There is limited methodology available to quantitatively assess the activity of the Delta9-desaturase enzyme in vivo without chemically inhibiting the enzyme or using radioactively labeled substrates. The objective of these experiments was to develop methodology to determine the incorporation and desaturation of 13C-labeled fatty acids into milk lipids. In a preliminary experiment, 3.7 g [1-13C]myristic acid ([1-13C]14:0), 19.5 g [1-13C]palmitic acid ([1-13C]16:0), 20.0 g [1-13C]stearic acid ([1-13C]18:0) were combined and infused into the duodenum of a cow over 24 h. In a following experiment, 5.0 g [1-13C]14:0, 40.0 g [1-13C]16:0, and 50.0 g [1-13C]18:0 were infused into the abomasums of separate cows as a bolus over 20 min or continuously over 24 h. Milk fat was extracted using chloroform:methanol. Fatty acids were methylated, and fatty acid methyl esters (FAME) were converted to dimethyl disulfide derivatives (DMDS). The FAME and DMDS were analyzed by gas chromatography mass spectrometry. In the preliminary experiment, 13C enrichment in 14:0 but not 16:0 or 18:0 was observed. When dosage amounts were increased in the following experiment, peak enrichments from the bolus infusion were observed at 8 h. Enrichments for continuous infusion peaked at 16 h for 14:0 and 18:0, and at 24 h for 16:0. The Delta9-desaturase products of these fatty acids were estimated to be 90% of cis-9 14:1, 50% of cis-9 16:1, and 59% of cis-9 18:1. This study demonstrates that 13C-labeled fatty acids may be utilized in vivo to measure the activity of the Delta9-desaturase enzyme.
Collapse
Affiliation(s)
- Erin E Mosley
- Department of Animal and Veterinary Science, University of Idaho, PO Box 442330, Moscow, ID 83844-2330, USA
| | | |
Collapse
|
8
|
Lengi AJ, Corl BA. Identification and characterization of a novel bovine stearoyl-CoA desaturase isoform with homology to human SCD5. Lipids 2007; 42:499-508. [PMID: 17468887 DOI: 10.1007/s11745-007-3056-2] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2007] [Accepted: 03/16/2007] [Indexed: 11/30/2022]
Abstract
Stearoyl-CoA desaturase (SCD) is an enzyme responsible for the production of cis-9, trans-11 conjugated linoleic acid in ruminant fats, and for the synthesis of palmitoleoyl-CoA and oleoyl-CoA. To date, only one SCD isoform has been described in ruminant species, although multiple isoforms have been found in many other mammalian species. In this paper, we describe for the first time a second SCD isoform in cattle, which appears to be an ortholog of human SCD5 rather than a homolog of bovine SCD1 or any of the described murine SCD isoforms. As described in other SCD proteins, the predicted amino acid sequence of bovine SCD5 includes four transmembrane domains and three conserved histidine motifs. The amino-terminus of the predicted protein sequence of SCD5 lacks the PEST sequences typically found in SCD1 homologs, which are thought to target proteins for rapid degradation. Similar to human SCD5, the bovine SCD5 gene is organized into five exons and four introns, and is highly expressed in the brain. In other tissues examined, mRNA expression of SCD5 was minimal. Furthermore, the expression levels of SCD5 between brain gray and white matter are not different. This is the first description of a homolog of human SCD5 in a non-primate species.
Collapse
Affiliation(s)
- Andrea J Lengi
- Department of Dairy Science, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
| | | |
Collapse
|
9
|
Mosley EE, Shafii Dagger B, Moate PJ, McGuire MA. cis-9, trans-11 conjugated linoleic acid is synthesized directly from vaccenic acid in lactating dairy cattle. J Nutr 2006; 136:570-5. [PMID: 16484526 DOI: 10.1093/jn/136.3.570] [Citation(s) in RCA: 98] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The utilization of (13)C-labeled vaccenic acid (VA) by lactating dairy cows to synthesize cis-9, trans-11 conjugated linoleic acid (CLA) was investigated. Primiparous ruminally cannulated Holstein cows (n = 3) were abomasally infused with 1.5 g of VA-1-(13)C. Blood and milk samples were taken frequently before and after VA infusion. Milk and plasma lipid were extracted using chloroform:methanol. Plasma lipid was separated into triacylglycerol (TG), cholesterol ester (CE), phospholipid (PL), nonesterified fatty acid (NEFA), and mono- and diacylglycerol (MDG) fractions. Lipid was methylated, converted to dimethyl disulfide and Diels-Alder adducts, and analyzed by GC-MS. Increased enrichment of (13)C was determined using a 2-sample t test for each sample time compared with -24 h, with significance declared at P < 0.05. Enrichment in milk fat VA was detected at 4 (3.0%), 8 (8.3%), 12 (4.1%), 16 (2.2%), and 20 h (0.8%). Enrichment in VA was also detected in plasma TG, NEFA, PL, and MDG. Enrichment in milk fat cis-9, trans-11 CLA, the Delta9-desaturase product of VA, was detected at 4 (2.6%), 8 (6.6%), 12 (3.4%), 16 (1.7%), and 24 h (0.7%). Enrichment was not detected in cis-9, trans-11 CLA for any plasma lipid fraction. Modeling of the data showed the exponential decay in (13)C enrichment over time for both VA and cis-9, trans-11 CLA in milk fat. Conversion of dietary VA to cis-9, trans-11 CLA endogenously was confirmed with the mammary gland being the primary site of Delta9-desaturase activity; approximately 80% of milk fat cis-9, trans-11 CLA originated from VA.
Collapse
Affiliation(s)
- Erin E Mosley
- Department of Animal and Veterinary Science, College of Agricultural and Life Sciences, University of Idaho, Moscow, ID 83844-2330, USA
| | | | | | | |
Collapse
|
10
|
Bernard L, Rouel J, Leroux C, Ferlay A, Faulconnier Y, Legrand P, Chilliard Y. Mammary Lipid Metabolism and Milk Fatty Acid Secretion in Alpine Goats Fed Vegetable Lipids. J Dairy Sci 2005; 88:1478-89. [PMID: 15778317 DOI: 10.3168/jds.s0022-0302(05)72816-2] [Citation(s) in RCA: 137] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Fourteen Alpine goats at midlactation were fed a diet of hay and concentrate (55:45), without (control) or with formaldehyde-treated linseed (FLS) or oleic sunflower oil (OSO) at 11.2 or 3.5% of dry matter intake, respectively, in a 3 x 3 Latin Square design with three 3-wk periods. Milk yield was lower in goats fed FLS than control or OSO (2.13 vs. 2.32 kg/d). Milk fat content was higher with FLS or OSO than control (40.8 vs. 33.8 g/kg). Formaldehyde-treated linseed and OSO caused a significant decrease (23 and 18%, respectively) of C10 to C17 fatty acids secretion compared with control. The secretion of cis-9 C18:1 and cis-9, trans-11 C18:2 were increased 1.44- and 1.54-fold for FLS and 1.78- and 1.36-fold for OSO, compared with control. The C18:3 (n-3) secretion was increased 2.61-fold with FLS compared with control. Milk cis-9 C14:1/C14:0, cis-9 C16:1/C16:0, and cis-9 C18:1/C18:0 ratios decreased with the supplemented diets compared with control. Mammary stearoyl-CoA desaturase mRNA and activity were decreased by the lipid supplements, whereas no significant change was observed for acetyl-CoA carboxylase and fatty acid synthase. The activities of glucose-6-phosphate dehydrogenase, malic enzyme, and glycerol-3-phosphate dehydrogenase were not affected by the lipid supplements. Mammary lipoprotein lipase mRNA increased with OSO, whereas lipoprotein lipase activity tended to decrease with FLS compared with control. Milk lipoprotein lipase activity sharply decreased with lipid supplement (by 59 and 71%, for FLS and OSO, respectively). The changes in milk fatty acid profile due to FLS and OSO supplements were partly related to changes in the levels of mammary enzyme activities or mRNA.
Collapse
Affiliation(s)
- L Bernard
- Unité de Recherche sur les Herbivores, Institut National de la Recherche Agronomique (INRA), Theix, 63 122 St. Genès-Champanelle, France
| | | | | | | | | | | | | |
Collapse
|
11
|
Kay JK, Mackle TR, Auldist MJ, Thomson NA, Bauman DE. Endogenous Synthesis of cis-9, trans-11 Conjugated Linoleic Acid in Dairy Cows Fed Fresh Pasture. J Dairy Sci 2004; 87:369-78. [PMID: 14762080 DOI: 10.3168/jds.s0022-0302(04)73176-8] [Citation(s) in RCA: 154] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
New Zealand Holstein-Friesian cows (n = 4) were used to quantify the importance of endogenous synthesis of cis-9, trans-11 conjugated linoleic acid (CLA) via Delta(9)-desaturase in cows fed a fresh pasture diet. The experiment was a 4 x 4 Latin square design with treatments arranged in a 2 x 2 factorial. Treatments lasted 4 d and were pasture only, pasture plus sterculic oil, pasture plus sunflower oil, and pasture plus sunflower oil plus sterculic oil. Abomasal infusion of sterculic oil inhibited Delta(9)-desaturase and decreased the concentration of cis-9, trans-11 CLA in milk fat by 70%. Using the changes in cis-9 10:1, cis-9 12:1 and cis-9 14:1 to correct for incomplete inhibition of Delta(9)-desaturase, a minimum estimate of 91% of cis-9, trans-11 CLA in milk fat was produced endogenously in cows fed fresh pasture. Dietary supplementation of a pasture diet with sunflower oil increased the proportion of long chain fatty acids in milk fat; however, the increase in vaccenic acid concentration was small (18%) and there was no increase in cis-9, trans-11 CLA concentration. Overall, results show that endogenous synthesis is responsible for more than 91% of the cis-9, trans-11 CLA secreted in milk fat of cows fed fresh pasture. However, the failure of plant oil supplements to increase the concentration of cis-9, trans-11 CLA in milk fat from pasture-fed cows requires further investigation.
Collapse
Affiliation(s)
- J K Kay
- Dexcel Ltd., Private Bag 3221, Hamilton, New Zealand
| | | | | | | | | |
Collapse
|
12
|
Corl BA, Baumgard LH, Griinari JM, Delmonte P, Morehouse KM, Yurawecz MP, Bauman DE. Trans-7,cis-9 CLA is synthesized endogenously by delta9-desaturase in dairy cows. Lipids 2002; 37:681-8. [PMID: 12216839 DOI: 10.1007/s11745-002-0949-4] [Citation(s) in RCA: 99] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Cis-9,trans-11 and trans-7,cis-9 CLA are the most prevalent CLA isomers in milkfat. The majority of cis-9,trans-11 CLA is synthesized endogenously by delta9-desaturase. We tested the hypothesis that trans-7,cis-9 CLA originates from endogenous synthesis by inhibiting delta9-desaturase with a source of cyclopropene FA (sterculic oil: SO) or with a trans-10,cis-12 CLA supplement. Experiment 1 (four cows; Latin square) involved four treatments: control, SO, partially hydrogenated vegetable oil (PHVO), and PHVO + SO. Milk, plasma, and rumen fluid were collected. Experiment 2 treatments (four cows) were 0 or 14.0 g/d of 10,12 CLA supplement; milk and plasma were collected. Samples were analyzed by GC and Ag+-HPLC to determine FA. In Experiment 1, SO decreased milkfat content of trans-7,cis-9 CLA by 68 to 71% and cis-9,trans-11 CLA by 61 to 65%. In Experiment 2, the 10,12 CLA supplement decreased milkfat content of trans-7,cis-9 CLA and cis-9,trans-11 by 44 and 25%, respectively. Correcting for the extent of treatment-induced inhibition of delta9-desaturase based on changes in myristic and myristoleic acids, endogenous synthesis of trans-7,cis-9 CLA represented 85 and 102% in Experiments 1 and 2, respectively. Similar corrected values were 77 and 58% for endogenous synthesis of cis-9,trans-11 CLA. Thus, milkfat cis-9,trans-11 CLA was primarily from endogenous synthesis with a minor portion from rumen escape. In contrast, trans-7,cis-9 CLA was not present in rumen fluid in significant amounts. Results indicate this isomer in milkfat is derived almost exclusively from endogenous synthesis via delta9-desaturase.
Collapse
Affiliation(s)
- Benjamin A Corl
- Department of Animal Science, Cornell University, Ithaca, New York, USA
| | | | | | | | | | | | | |
Collapse
|
13
|
Corl BA, Baumgard LH, Dwyer DA, Griinari JM, Phillips BS, Bauman DE. The role of Delta(9)-desaturase in the production of cis-9, trans-11 CLA. J Nutr Biochem 2001; 12:622-630. [PMID: 12031255 DOI: 10.1016/s0955-2863(01)00180-2] [Citation(s) in RCA: 285] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Biomedical studies with animal models have demonstrated that cis-9, trans-11 conjugated linoleic acid (CLA), the predominant isomer found in milk fat from dairy cows, has anticarcinogenic effects. We recently demonstrated endogenous synthesis of cis-9, trans-11 CLA from ruminally derived trans-11 C18:1 by Delta(9)-desaturase in lactating dairy cows. The present study further examined endogenous synthesis of cis-9, trans-11 CLA and quantified its importance by increasing substrate supply using partially hydrogenated vegetable oil (PHVO) as a source of trans-11 C18:1 and blocking endogenous synthesis using sterculic oil (SO) as a source of cyclopropene fatty acids which specifically inhibit Delta(9)-desaturase. Four cows were abomasally infused with 1) control, 2) PHVO, 3) SO, and 4) PHVO+SO in a 4 x 4 Latin square design. With infusion of PHVO, cis-9, trans-11 CLA was increased by 17% in milk fat. Consistent with inhibition of desaturase, SO treatments increased milk fat ratios for the fatty acid pairs effected by Delta(9)-desaturase, C14:0/cis-9 C14:1, C16:0/cis-9 C16:1, and C18:0/cis-9 C18:1. The role of endogenous synthesis of CLA was evident from the 60-65% reduction in cis-9, trans-11 CLA which occurred in milk fat with SO treatments. cis-9 C14:1 originates from desaturation of C14:0 by Delta(9)-desaturase and can be used to estimate the extent of SO inhibition of Delta(9)-desaturase. When this correction factor was applied, endogenous synthesis was estimated to account for 78% of the total cis-9, trans-11 CLA in milk fat. Thus, endogenous synthesis was the major source of cis-9, trans-11 CLA in milk fat of lactating cows.
Collapse
Affiliation(s)
- Benjamin A. Corl
- Department of Animal Science, Cornell University, 262 Morrison Hall, 14853-4801, Ithaca, NY, USA
| | | | | | | | | | | |
Collapse
|
14
|
Emken EA, Adlof RO, Hachey DL, Garza C, Thomas MR, Brown-Booth L. Incorporation of deuterium-labeled fatty acids into human milk, plasma, and lipoprotein phospholipids and cholesteryl esters. J Lipid Res 1989. [DOI: 10.1016/s0022-2275(20)38367-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
|
15
|
George M, Chepenik KP. Phospholipase A activities in embryonic palate mesenchyme cells in vitro. BIOCHIMICA ET BIOPHYSICA ACTA 1985; 836:45-55. [PMID: 3927980 DOI: 10.1016/0005-2760(85)90218-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Incubation of palate mesenchyme cells in vitro in the presence of [3H]arachidonate and [14C]palmitate resulted in incorporation of radiolabel into all major families of phospholipids. Almost all (more than 90%) of the 3H and about one-half of the 14C in the phospholipids were in the sn-2 position. The [14C] fatty acid in the sn-2 position was saturate. When [14C]stearate was added to the culture medium with [3H]arachidonate, 30-40% of the total 14C in phospholipids was in the sn-2 position. 80% of the 14C in the sn-2 position was found in unsaturated fatty acids. Hydrolysis of phospholipids could be demonstrated at acid, neutral and alkaline pH. Calcium stimulated phospholipase activity at neutral and alkaline pH, but inhibited hydrolytic activity at acid pH. Radiolabeled lysophospholipid indicative of phospholipase A2 activities accumulated at acid pH, whereas little, if any, radiolabeled lysophospholipids accumulated at neutral and alkaline pH. Quantitative analysis revealed the production of some lysophosphatidylethanolamine at alkaline pH.
Collapse
|
16
|
Foot M, Jeffcoat R, Russell NJ. Some properties, including the substrate in vivo, of the delta 9-desaturase in Micrococcus cryophilus. Biochem J 1983; 209:345-53. [PMID: 6847622 PMCID: PMC1154100 DOI: 10.1042/bj2090345] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The delta 9-desaturase of the psychrophilic bacterium Micrococcus cryophilus is shown to be a membrane-bound enzyme that is probably linked to a cyanide- (and azide-) sensitive respiratory chain with oxygen as the final acceptor. It has a pH optimum of 8.7 and contains an essential thiol group, but has no special ion requirements. The desaturase activity of washed membranes could not be increased by adding supernatant or NADH and NADPH, possibly owing to the endogenous generation of reduced cofactors by the membranes. The substrate for the desaturase is not acyl-CoA and is probably not acyl-acyl-carrier protein. Evidence is presented that the substrate in vivo is saturated phospholipid and a scheme for the possible routes of incorporation of exogenous stearic acid into oleoyl-phospholipid is presented.
Collapse
|
17
|
Calabro MA, Prasad MR, Wakil SJ, Joshi VC. Stearoyl-coenzyme A desaturase activity in the mammary gland and liver of lactating rats. Lipids 1982; 17:397-402. [PMID: 6125866 DOI: 10.1007/bf02535218] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Stearoyl-CoA desaturase activity in microsomes from lactating rat mammary gland is very low (0.05-0.15 nmol/min/mg of protein) regardless of lactating time. In such microsomes, reductase activities and content of cytochrome b5 are several-fold lower than in normal rat liver microsomes. Preincubation of the mammary microsomes with purified terminal desaturase gives a 55-fold stimulation of stearoyl-CoA desaturase activity, whereas preincubation with cytochrome b5 has no effect. However, preincubation of mammary microsomes with both cytochrome b5 and terminal desaturase results in a 200-fold stimulation of overall desaturation. These observations suggest that negligible stearoyl-CoA desaturase activity in lactating rat mammary microsomes is due to a cytochrome b5 content and the absence of terminal enzyme. The hepatic stearoyl-CoA desaturase activity increases 9-fold during lactation. There is little or no change in the NADH-cytochrome c reductase activity or in the concentrations of cytochrome b5 during this period, but the activity of the terminal desaturase increases with the increase of overall desaturation. These results suggest that liver is one of the more important sources of oleic acid for milk triglycerides.
Collapse
|
18
|
Ahuja SP, Srivastava G. Studies on the blood transport of 1-14C-palmitate and its conversion into other fatty acids by buffalo (Bos bubalis) mammary glands. ZENTRALBLATT FUR VETERINARMEDIZIN. REIHE A 1978; 25:485-93. [PMID: 104493 DOI: 10.1111/j.1439-0442.1978.tb00947.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
|
19
|
Fukushima H, Nagao S, Okano Y, Nozawa Y. Studies on Tetrahymena membranes. Palmitoyl-coenzyme a desaturase, a possible key enzyme for temperature adaptation in Tetrahymena microsomes. BIOCHIMICA ET BIOPHYSICA ACTA 1977; 488:442-53. [PMID: 20149 DOI: 10.1016/0005-2760(77)90202-8] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
(1) Microsomes from a thermotolerant Tetrahymena NT-1 catalyze the conversion of palmitoyl-CoA to palmitoleate. (2) Palmitoyl-CoA desaturase enzyme requires molecular oxygen and NADH or NADPH as cofactor and its activity is inhibited by cyanide. A pH optimum range 7.0--7.3 is observed. (3) There is a clear break at 30 degrees C and a slight bend around 15 degrees C in the Arrhenius plots of palmitoyl-CoA desaturase activity. (4) After quenching from 39.5 degrees C, at 26 degrees C microsomal membranes show small particle-free areas, when examined by freeze-fracture electron microscopy, indicating the onset of phase separation. Larger smooth areas devoid of membrane-intercalated particles are observed in microsomes at 23 and 15 degrees C. The results support evidence that the thermally induced transition of desaturase enzyme activity in related to the altered membrane properties due to temperature change.
Collapse
|
20
|
Jarasch ED, Bruder G, Keenan TW, Franke WW. Redox constituents in milk fat globule membranes and rough endoplasmic reticulum from lactating mammary gland. J Cell Biol 1977; 73:223-41. [PMID: 856833 PMCID: PMC2109886 DOI: 10.1083/jcb.73.1.223] [Citation(s) in RCA: 63] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Milk fat globule membranes (MFGM) and rough endoplasmic reticulum (RER) membranes were isolated from milk and lactating mammary gland from the cow and were characterized by biochemical and electron microscope methods in terms of gross composition (proteins, phospholipids, neutral lipids, cholesterol, RNA, and DNA) and purity. Both fractions contained significant amounts of a b-type cytochrome with several properties similar to those of cytochrome b5 from liver, as well as a rotenone-insensitive NADH- and NADPH-cytochrome c reductase. The b-type cytochrome content in the apical plasma membrane-derived MFGM was of the same order of magnitude as it was in RER membranes. It was characterized by a high resistance to extraction by low- and high-salt concentrations and nonionic detergents. MFGM contained much more flavin and much higher activities of xanthine oxidase than the RER membranes. The same redox components were found in MFGM and mammary RER from women, rats, mice, and goats, but in absolute contents great differences between the species were noted. The cytochromes described here differed from liver cytochrome b5 in some spectral properties. The alpha-band of the reduced hepatic cytochrome b5 is asymmetric with a maximum at 555 nm that is split into two distinct peaks at low temperatures. The alpha-band of the b-type cytochromes from MFGM and mammary RER appears as one symmetrical peak at about 560 nm that is not split at low temperatures. When treated with cyanide, MFGM and mammary microsomes showed difference spectra of a reduced b-type cytochrome. Under the same conditions, liver microsomes gave a completely different spectrum. These findings demonstrate the presence of a b-type cytochrome and associated redox enzymes in MFGM, i.e., a derivative of the apical cell surface membrane that is regularly used for envelopment of the milk fat globule during secretion.
Collapse
|
21
|
Kinsella JE. Monoacyl-sn-glycerol 3-phosphate acyltransferase specificity in bovine mammary microsomes. Lipids 1976; 11:680-4. [PMID: 994758 DOI: 10.1007/bf02532886] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The acyl-CoA:acyl-sn-glycerol 3-phosphate acyltransferases located in the microsomal fraction of lactating bovine mammary tissue show a preference for palmityl-CoA particularly above the apparent Km values of the acyl acceptors. Using saturating levels of monopalmityl-sn-glycerol 3-phosphate, the order of acylation was palmityl- greater than myristyl- greater than oleyl- greater than stearyl- greater than linoleyl-CoA. Apparent Km values for monopalmityl- and mono-oleyl-sn-glycerol 3-phosphate with palmityl-CoA as donor were 16 and 13muM, respectively while the Km values for palmityl-CoA with these two acyl acceptors were 5 and 5.2muM, RESPECTIVELY. The apparent Vmax values for the palmityl acceptor and donor were 25 and 30 nmol/min/mg protein. Phosphatidic acid was the principal product. The inclusion of magnesium in the assay depressed activity while the addition of ethylenediaminetetraacetate doubled the rate of acylation.
Collapse
|
22
|
Tamura Y, Yoshida Y, Sato R, Kumaoka H. Fatty acid desaturase system of yeast microsomes. Involvement of cytochrome b5-containing electron-transport chain. Arch Biochem Biophys 1976; 175:284-94. [PMID: 8011 DOI: 10.1016/0003-9861(76)90510-5] [Citation(s) in RCA: 40] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
|
23
|
|
24
|
|
25
|
Caffrey M, Infante JP, Kinsella JE. Isoenzymes of an acyl transferase from rabbit mammary gland: evidence from biphasic substrate saturation kinetics. FEBS Lett 1975; 52:116-20. [PMID: 1123073 DOI: 10.1016/0014-5793(75)80651-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
|
26
|
Coincident synthesis of fatty acids and secretory triglygerides in bovine mammary tissue. ACTA ACUST UNITED AC 1975. [DOI: 10.1016/0020-711x(75)90047-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|
27
|
Gross MJ, Kinsella JE. Properties of palmityl-CoA: L-alpha-glycerolphosphate acyl transferase from bovine mammary microsomes. Lipids 1974; 9:905-12. [PMID: 4215933 DOI: 10.1007/bf02532617] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
|
28
|
|
29
|
Kinsella JE, Infante JP. Acyl-CoA acyl-sn glycerol-3 phosphorylcholine acyl transferase of bovine mammary tissue. Lipids 1974; 9:748-51. [PMID: 4427513 DOI: 10.1007/bf02532140] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
|
30
|
Rao GA, Abraham S. Fatty acid desaturation by mammary gland microsomes from lactating mice. Lipids 1974; 9:269-71. [PMID: 4151590 DOI: 10.1007/bf02532204] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
|