stearoyl-CoA Desaturase Gene Expression Research Articles

Effects of fish oil supplementation and supplementation period on adipose tissue generation sites and the gene expression of enzymes involved in metabolizing adipose tissue in Holstein bulls under various forage types

To investigate the effects of alfalfa hay (AH) proportion, fish oil (FO) supplementation, and the length of FO supplementation on lipoprotein lipase (LPL), peroxisome proliferator activated receptorγ (PPARγ) and stearoyl-COA desaturase (SCD) gene expression in various adipose tissue depots, 36 Holstein bulls (initial body weight of 345±61kg) were randomly assigned to 6 dietary treatments in a 2×3 factorial arrangement, with 2 levels of AH (10 and 20% of dietary dry matter) and 3 levels of FO (0, 1.05 and 2.1% of dry matter). Samples of adipose tissue were collected at the middle and end of the period (day 90), after slaughtering. The RT-qPCR technique was used for gene expression analyses. The relative mRNA abundance of lipogenic genes was not correlated with AH proportion and FO interaction. Supplementation of FO increased LPL and SCD gene expression in visceral and subcutaneous adipose tissues regardless of AH proportion (P<0.05). The gene expression of PPARγ was not affected by dietary treatments. Supplementation of FO increased the mRNA abundance of SCD1 gene more in subcutaneous than visceral adipose tissue (P<0.01). Gene expression of PPARγ and SCD enzymes increased as a result of prolonged FO supplementation (P<0.01), whereas LPL mRNA abundance was lower at the end of period comparing to the middle period (P<0.01). The results demonstrate that FO supplementation increases the abundance of adipose tissue SCD mRNA, which in the case of enhancement in UFAs concentration as a result of higher mRNA abundance and enzyme activity, can benefit both human and animal health. Moreover, the duration of FO supplementation was found to be an important factor in regulating enzymes involved in adipose tissue metabolism.

Modulation of adipogenesis-related gene expression by ethanol extracts of Detam 1 soybean and Jati belanda leaf in 3T3-L1 cells

&lt;p class="Abstract"&gt;In this study, we evaluated the effects of ethanol extracts of Detam 1 soybean, Jati belanda leaf, and the combination toward expression of peroxisome proliferator-activated receptor gamma (PPARγ), CCAAT/enhancer-binding protein alpha (C/EBPα), and stearoyl-CoA desaturase 1 (SCD1) genes in 3T3-L1 cells as anti-adipogenesis and anti-obesity. The differentiation of 3T3-L1 cells into adipocyte was conducted using induction medium consist of Dulbecco's Modified Eagle's Medium, 3-isobutyl-1-methylxanthine, insulin, dexamethasone, and fetal bovine serum. The expression of PPARγ, C/EBPα, and SCD1 gene was measured using real-time quantitative polymerase chain reaction (qPCR). Ethanol extract of Jati belanda at a concentration of 50 μg/mL was most effective to reduce PPARγ, C/EBPα, and SCD1 gene expression in 3T3-L1 cells. Ethanol extract of Detam 1 soybean failed to reduce PPARγ gene expression, whilst in the concentration of 50 μg/mL it was able to significantly reduce the C/EBPα and SCD1 gene expression. Both ethanol extracts of Detam 1 soybean and Jati belanda have potential as anti-adipogenesis and anti-obesity by suppressing adipogenesis-related gene expression, particularly C/EBPα and SCD1.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Video Clip:&lt;/strong&gt;&lt;/p&gt;&lt;p&gt;&lt;a href="https://youtube.com/v/UWv9nChmF2Y"&gt;Maintaining 3T3-L1 cell culture&lt;/a&gt;: 5 min 15 sec&lt;/p&gt;

Oleic acid enhances G protein coupled receptor 43 expression in bovine intramuscular adipocytes but not in subcutaneous adipocytes1

We hypothesized that fatty acids would differentially affect G protein coupled receptor (GPR) 43 mRNA expression and GPR43 protein concentrations in bovine intramuscular (IM) and subcutaneous (SC) adipocytes. The GPR43 protein was detected in bovine liver, pancreas, and semimembranosus (MUS) muscle in samples taken at slaughter. Similarly, GPR43 protein levels were similar in IM adipose tissue and SM muscle but was barely detectable in SC adipose tissue. Primary cultures of IM and SC stromal vascular cells were isolated from bovine adipose tissues. Oleic acid (100 μ) stimulated PPARγ gene expression and decreased stearoyl-CoA desaturase (SCD) gene expression but had no effect on GPR43 gene expression, which was readily detectable in both IM and SC adipocytes. Differentiation cocktail (Diff; 10 μ insulin, 4 μ dexamethasone, and 10 μ ciglitizone) stimulated CCAAT/enhancer-binding protein β (C/EBPβ) and PPARγ gene expression in SC but not IM adipocytes, but Diff increased SCD gene expression in both cell types. Linoleic acid (10 µ) increased PPARγ gene expression relative to Diff cocktail in SC adipocytes, whereas linoleic acid and α-linolenic decreased SCD gene expression relative to control adipocytes and adipocytes incubated with Diff ( < 0.05). Increasing concentrations of oleic acid (1, 10, 100, and 500 μM) increased GPR43 protein and mRNA expression in IM but not SC adipocytes. These data indicated that oleic acid alters mRNA and protein concentrations of GPR43 in bovine IM adipocytes.

The Expression of Adipogenic Genes in Adipose Tissues of Feedlot Steers Fed Supplementary Palm Oil or Soybean Oil.

We hypothesized that supplementing finishing diets with palm oil would promote adipogenic gene expression and stearoyl-CoA desaturase (SCD) gene expression in subcutaneous (s.c.) and intramuscular (i.m.) adipose tissues of feedlot steers. Eighteen Angus and Angus crossbred steers were assigned to three groups of 6 steers and fed a basal diet (control), with 3% palm oil, or with 3% soybean oil, for 70 d, top-dressed daily. Tailhead s.c. adipose tissue was obtained by biopsy at 14 d before the initiation of dietary treatments and at 35 d of dietary treatments. At slaughter, after 70 d of dietary treatment, tailhead s.c. adipose tissue and i.m. adipose tissue were obtained from the longissimus thoracis muscle. Palm oil increased plasma palmitic acid and soybean oil increased plasma linoleic acid and α-linolenic acid relative to the initial sampling time. Expression of AMP-activated protein kinase alpha (AMPKα) and peroxisome proliferator-activated receptor gamma (PPARγ) increased between the initial and intermediate biopsies and declined thereafter (p<0.03). SCD gene expression did not change between the initial and intermediate biopsies but declined by over 75% by the final period (p = 0.04), and G-coupled protein receptor 43 (GPR43) gene expression was unaffected by diet or time on trial. Soybean oil decreased (p = 0.01) PPARγ gene expression at the intermediate sample time. At the terminal sample time, PPARγ and SCD gene expression was less in i.m. adipose tissue than in s.c. adipose tissue (p<0.05). AMPKα gene expression was less in s.c. adipose tissue of palm oil-fed steers than in control steers (p = 0.04) and CCAAT enhancer binding protein-beta (CEBPβ) gene expression was less in s.c. and i.m. adipose tissues of palm oil-fed steers than in soybean oil-fed steers (p<0.03). Soybean oil decreased SCD gene expression in s.c. adipose tissue (p = 0.05); SCD gene expression in palm oil-fed steers was intermediate between control and soybean oil-fed steers. Contrary to our original hypothesis, palm oil did not promote adipogenic gene expression in s.c. and i.m. adipose tissue.

The expression of the SCD1 gene and its correlation with fattening and carcass traits in sheep

Abstract. Stearoyl-CoA desaturase 1 (SCD1) is a critical enzyme that catalyzes the synthesis of monounsaturated fatty acids and is involved in several signaling pathways related to lipid metabolism. The objective of the present study was to estimate the expression of the SCD1 gene in three different ovine tissues strongly associated with lipid homeostasis. The SCD1 gene expression measurement was performed on three tissues (liver, subcutaneous fat, perirenal fat) originated from 15 old-type Polish Merino sheep. The SCD1 transcript abundance was evaluated based on the two most stable endogenous controls (RPS2 – ribosomal protein S2; ATP5G2 – H(+)-transporting ATP synthase). The highest expression of the SCD1 gene was observed in ovine subcutaneous fat compared to perirenal fat and liver. Furthermore, the present research indicated the significant correlation between ovine SCD1 transcript abundance and several important production traits. The expression of the SCD1 gene in liver and perirenal fat highly positively correlated with the feed : gain ratio, test of daily gain and age of the animals at slaughter. Moreover, in both tissues, the SCD1mRNA level positively correlated with weight and content of perirenal fat and subcutaneous fat (R = 0.64, 0.8, 0.6, respectively) and negatively with assessment of external fat content with the use of the EUROP scale (R = −0.64). The SCD1 expression in subcutaneous fat also corresponds with back fat of blade chop and thickness of longissimus dorsi muscles evaluated using USG (ultrasonography) (R = −0.6 and 0.62, respectively). The significant correlation between SCD1 transcript abundance and fattening and slaughtering traits indicate the ability to improve important production traits in sheep via modification of expression of the SCD1 gene.

Effect of hydrogenated palm oil dietary supplementation on milk yield and composition, fatty acids profile and Stearoyl-CoA desaturase expression in goat milk

Aim of this study was to investigate the effects of supplementing dairy goat diets with hydrogenated palm oil (HPO; 50g/day/head) on milk yield and composition, and on milk fatty acids profile and Stearoyl-CoA desaturase gene expression. Compared with the control diet (C), supplementation with HPO increased milk yield and fat percentage. By contrast, milk protein percentage was not different between groups. Supplementation with HPO increased (P<0.01) short and medium chain fatty acids, as well as C14:0 and C16:1 cis-9 acids (P<0.05). Milk from control group showed significantly (P<0.01) higher concentration of C18:0 and lower (P<0.05) of cis-9 trans-11CLA. Concerning the desaturase index, the HPO addition significantly affected C16:1/C16:0 and cis-9 trans-11CLA/C18:1 trans-11 (P<0.01) and C18:1/C18:0 (P<0.05) ratios. The SCD gene expression (arbitrary units) was higher, even if not significantly, in the control compared to the treated group and in both groups decreased along the trial (May: 0.55 vs 0.41; June: 0.51 vs 0.38; July: 0.50 vs 0.37 for C and T group, respectively). Concerning health properties of milk, showing beneficial (CLAs and palmitoleic acid increase) and adverse (myristic acid increase) effect, our results suggest that further studies are needed to address a risk/benefit assessment of HPO supplementation in goats.

Changes in the physiological parameters, fatty acid metabolism, and SCD activity and expression in juvenile GIFT tilapia (Oreochromis niloticus) reared at three different temperatures.

We evaluated the effects of rearing temperature on the composition of fatty acids and stearoyl-CoA desaturase (SCD) activity and gene expression in GIFT (genetically improved farmed tilapia) tilapia. Three triplicate groups of fish were reared for 40days at 22, 28, or 34°C. At the end of the trial, the final body weight of juveniles reared at 28°C was higher than that of fish reared at 22 or 34°C. Feed intake, feed efficiency, and the protein efficiency ratio were also higher at 28°C. The fatty acid composition of muscle tissue differed significantly (P<0.05) among the treatment groups. The content of SFA decreased with decreasing temperature, whereas the UFA content increased. We observed high levels of PUFA, particularly n-3 PUFAs, in fish reared at the lower temperature. Rearing at low temperature significantly (P<0.05) increased the expression and activity of the SCD gene. Increased SCD activity and gene expression can increase the biosynthesis of MUFAs in GIFT tilapia muscle. Additionally, cold acclimation can decrease the content of TC and TG in GIFT tilapia, which can help increase cold tolerance.

Stearoyl-CoA desaturase 1 and paracrine diffusible signals have a major role in the promotion of breast cancer cell migration induced by cancer-associated fibroblasts.

Background:Despite the recognised contribution of the stroma to breast cancer development and progression, the effective targeting of the tumor microenvironment remains a challenge to be addressed. We previously reported that normal fibroblasts (NFs) and, notably, breast cancer-associated fibroblasts (CAFs) induced epithelial-to-mesenchymal transition and increases in cell membrane fluidity and migration in well- (MCF-7) and poorly-differentiated (MDA-MB-231) breast cancer cells. This study was designed to better define the role played, especially by CAFs, in promoting breast tumor cell migration.Methods:Fibroblast/breast cancer cell co-cultures were set up to investigate the influence of NFs and CAFs on gene and protein expression of Stearoyl-CoA desaturase 1 (SCD1), the main enzyme regulating membrane fluidity, as well as on the protein level and activity of its transcription factor, the sterol regulatory element-binding protein 1 (SREBP1), in MCF-7 and MDA-MB-231 cells. To assess the role of SREBP1 in the regulation of SCD1 expression, the desaturase levels were also determined in tumor cells treated with an SREBP1 inhibitor. Migration was evaluated by wound-healing assay in SCD1-inhibited (by small-interfering RNA (siRNA) or pharmacologically) cancer cells and the effect of CAF-conditioned medium was also assessed. To define the role of stroma-derived signals in cancer cell migration speed, cell-tracking analysis was performed in the presence of neutralising antibodies to hepatocyte growth factor, transforming growth factor-β or basic fibroblast growth factor.Results:A two to three fold increase in SCD1 mRNA and protein expression has been induced, particularly by CAFs, in the two cancer cell lines that appear to be dependent on SREBP1 activity in MCF-7 but not in MDA-MB-231 cells. Both siRNA-mediated and pharmacological inhibition of SCD1 impaired tumor cells migration, also when promoted by CAF-released soluble factors. Fibroblast-triggered increase in cancer cell migration speed was markedly reduced or abolished by neutralising the above growth factors.Conclusion:These results provide further insights in understanding the role of CAFs in promoting tumor cell migration, which may help to design new stroma-based therapeutic strategies.

Diet high in α-linolenic acid up-regulate PPAR-α gene expression in the liver of goats

article i nfo Background:There is little information on the effects of diets containing high α-linolenic acid (C18:3n-3) on liver lipid composition and lipogenic gene expressions. In this study fourteen goats (Capra aegagrus hircus )w ere fed either a flaxseed oil (FSO) supplemented diet containing high α-linolenic acid or a control diet without added flaxseed oil (CON) for 100-d to evaluate the effects on liver lipid composition and the gene expression of peroxisome proliferator-activated receptors (PPAR-α) and stearoyl-CoA-desaturase (SCD) in the liver. Results: An increase in the levels of C18:3n-3 and C20:5n-3, C22:5n-3, C22:6n-3 was observed in the liver of FSO-treated goats. There was a significant (P b 0.05) up-regulation of PPAR-α gene expression and downregulation of SCD gene in the liver of goats fed the high α-linolenic acid diet. Conclusions: In conclusion, genes associated with the control of fatty acid (FA) conversion (SCD and PPAR) were affected by the α-linolenic acid supplementation in the goat diet. It is suggested that PPAR-α is the key messenger responsible for the translation of nutritional stimuli into changes in hepatic gene expression.

The effect of breed and feeding level on carcass composition, fatty acid profile and expression of genes encoding enzymes involved in fat metabolism in two muscles of pigs fed a diet enriched in n-3 fatty acids. A preliminary study

The experiment was performed according to a 2 x 2 factorial design with breed and level of nutrition as factors affecting fat metabolism in pigs. Two groups of gilts, each comprising 4 Polish Large White (PLW) and 4 Synthetic Line 990 (L990) animals, were fed from 60 to 105 kg body weight on the experimental diet at 85% or 95% of assumed ad libitum intake. The diet contained 2% of linseed, 0.5% rapeseed and 0.5% fish oils as the source of n-3 fatty acids (FA). The carcass protein content was smaller and backfat thick- ness greater in L990 than in PLW pigs. Also the intramuscular fat content in the biceps femoris (BF) and longissimus dorsi (LD) muscles and their contents of total FA, saturated fatty acids, monounsaturated fatty acids (MUFA) and poly- unsaturated fatty acids (PUFA) were higher or tended to be higher in L990 than in PLW pigs, the differences between the breeds being more pronounced in the BF muscle. The n-6/n-3 PUFA ratio tended to be lower in the LD muscle, whereas in the BF muscle, it was lower in L990 than in PLW pigs. Feeding at the 85% level resulted in smaller backfat thickness and carcass fat con- tent in animals of both breeds. Gene expression of stearoyl-CoA desaturase in both muscles was higher in L990 pigs, which could have resulted in the higher MUFA and PUFA contents in this breed. Gene expression of fatty acid-binding protein 4 and peroxisome proliferator-activated receptor were affected both by breed and feeding level only in the BF muscle.

AMPKα, C/EBPβ, CPT1β, GPR43, PPARγ, and SCD Gene Expression in Single- and Co-cultured Bovine Satellite Cells and Intramuscular Preadipocytes Treated with Palmitic, Stearic, Oleic, and Linoleic Acid

We previously demonstrated that bovine subcutaneous preadipocytes promote adipogenic gene expression in muscle satellite cells in a co-culture system. Herein we hypothesize that saturated fatty acids would promote adipogenic/lipogenic gene expression, whereas mono- and polyunsaturated fatty acids would have the opposite effect. Bovine semimembranosus satellite cells (BSC) and intramuscular preadipocytes (IPA) were isolated from crossbred steers and cultured with 10% fetal bovine serum (FBS)/Dulbecco’s Modified Eagle Medium (DMEM) and 1% antibiotics during the 3-d proliferation period. After proliferation, cells were treated for 3 d with 3% horse serum/DMEM (BSC) or 5% FBS/DMEM (IPA) with antibiotics. Media also contained 10 μg/mL insulin and 10 μg/mL pioglitazone. Subsequently, differentiating BSC and IPA were cultured in their respective media with 40 μM palmitic, stearic, oleic, or linoleic acid for 4 d. Finally, BSC and IPA were single- or co-cultured for an additional 2 h. All fatty acid treatments increased (p = 0.001) carnitine palmitoyltransferase-1 beta (CPT1β) gene expression, but the increase in CPT1β gene expression was especially pronounced in IPA incubated with palmitic and stearic acid (6- to 17- fold increases). Oleic and linoleic acid decreased (p = 0.001) stearoyl-CoA desaturase (SCD) gene expression over 80% in both BSC and IPA. Conversely, palmitic and stearic acid increased SCD gene expression three fold in co-cultured in IPA, and stearic acid increased AMPKα gene expression in single- and co-cultured BSC and IPA. Consistent with our hypothesis, saturated fatty acids, especially stearic acid, promoted adipogenic and lipogenic gene expression, whereas unsaturated fatty acids decreased expression of those genes associated with fatty acid metabolism.

Visceral and subcutaneous adipose tissue stearoyl‐CoA desaturase‐1 mRNA levels and fatty acid desaturation index positively correlate with BMI in morbidly obese women

The aim of this study was to re‐evaluate possible associations between BMI and (1) stearoyl‐CoA desaturase‐1 (SCD1) gene expression in adipose tissue; (2) adipose tissue or serum lipids oleic acid/stearic acid (18:1/18:0) desaturation index (DI); and (3) expression of less studied SCD isoform SCD5 in adipose tissue of obese patients. SCD1 and SCD5 mRNA levels in adipose tissue from 16 morbidly obese women were analyzed by RT‐PCR. Fatty acid composition of adipose tissue and whole serum lipids were determined with gas chromatography‐mass spectrometry. The SCD1 mRNA levels, as well as 18:1/18:0 DI in adipose tissue, correlated positively with BMI in obese patients. A weak positive association between the serum lipid 18:1/18:0 DI and BMI did not reach the threshold of statistical significance. The SCD5 mRNA levels in adipose tissue were approximately 400 times lower than the SCD1 levels and did not correlate with BMI. Positive correlations between BMI and visceral or subcutaneous adipose tissue 18:1/18:0 DI were stronger than the association between serum whole lipid 18:1/18:0 DI and BMI in morbidly obese women. The expression of the SCD1 gene in human adipose tissue is markedly stronger than the expression of the SCD5 gene.Practical applications: Our findings confirm previous suggestions that SCD1 may serve as an attractive therapeutic target in patients with obesity and related disorders.Oleic acid/stearic acid (18:1/18:0) desaturation index (DI) in adipose tissue of obese subjects reflects the level of SCD1 gene expression in adipose tissue. Positive correlations between BMI and adipose tissue DI were stronger than the association between serum whole lipid DI and BMI in morbidly obese women.

The effects of linseed or chia seed dietary supplementation on adipose tissue development, fatty acid composition, and lipogenic gene expression in lambs

This study examined the effects of linseed or chia seed supplementation on growth and carcass parameters, fatty acid composition, and expression of six lipogenic genes in the intramuscular (IM) and subcutaneous (SC) adipose tissues (AT) in lambs. Thirty-one male Navarra breed lambs (56.5±1.6 d old) were weaned at 16.8±0.3kg live weight (LW) and assigned randomly into three dietary groups: a control group diet of barley and soybean (C); the C diet with 10.5% linseed (L) and the C diet with 10% chia seed (Chia). The lambs were collectively reared in pens (4 weeks) and slaughtered at an average LW of 26.6±0.2kg. The results indicated that supplementing lambs’ diet with either linseed or chia seed, both rich in α-linolenic acid (ALA, C18:3n-3), had no effect on the growth parameters. Supplementation of either linseed or chia seed increased the ALA, C18:1t11, eicosapentaenoic acid (EPA, C20:5n-3), and total n-3 fatty acid contents (P<0.01), and decreased the n-6/n-3 ratio in the IM- and SC-AT (P<0.001). Supplementation of linseed increased the proportion of docosapentaenoic acid (DPA; 22:5n-3) in both the IM- and SC-AT (P<0.01), while supplemented chia seed increased the DPA content in the IM-AT (P<0.01). Downregulation of acetyl-CoA carboxylase 1 or alpha (ACACA), stearoyl-CoA desaturase (SCD) and fatty acid desaturase 2 (FADS2) was observed in the IM-AT in the linseed and chia seed-supplemented lambs (P<0.05). The linseed-containing diet did not change lipoprotein lipase (LPL) or fatty acid desaturase 1 (FADS1) gene expression in the IM-AT, whereas chia seed downregulated the expression of those genes (P<0.01). On the contrary, supplementing either linseed or chia seed had no effect on ACACA, SCD, or LPL gene expression in the SC-AT. Supplementing linseed decreased FADS1, FADS2, and fatty acid elongase 5 (ELOVL5) mRNA in the SC-AT (P<0.01), whereas supplemented chia seed decreased ELOVL5 expression (P<0.001). Consequently, changes in fatty acid composition caused by dietary linseed or chia seed might be, at least partly, mediated by the regulation of several genes involved in lipogenesis and the regulation seems to be tissue-specific.

Effects of dietary fat saturation on fatty acid composition and gene transcription in different tissues of Iberian pigs

The effect of two diets, respectively enriched with SFA (S) and PUFA (P), on FA tissue composition and gene expression was studied in fattened Iberian pigs. The FA composition of adipose, muscular and liver tissues was affected by dietary treatment. S group showed higher MUFA and MUFA/SFA ratio and lower PUFA and n−6/n−3 ratio than P group in all analyzed tissues. In muscle and liver the extracted lipids were separated into neutral lipids and polar lipid fractions which showed significantly different responses to the dietary treatment, especially in liver where no significant effect of diet was observed in NL fraction. The expression of six candidate genes related to lipogenesis and FA oxidation was analyzed by qPCR. In liver, stearoyl CoA desaturase (SCD), acetyl CoA carboxylase alpha (ACACA) and malic enzyme 1 (ME1) genes showed higher expression in S group. SCD, ACACA, ME1, and fatty acid synthase (FASN) gene expression levels showed a wide variation across the tested tissues, with much higher expression levels observed in adipose tissue than other tissues. Tissue FA profile and gene expression results support the deposition of dietary FA, the lipogenic effect of dietary saturated fat in liver and the employment of saturated dietary fat for endogenous synthesis of MUFA in all the analyzed tissues.

Flax meal supplementation on the activity of antioxidant enzymes and the expression of oxidative stress- and lipogenic-related genes in dairy cows infused with sunflower oil in the abomasum

The effects of abomasal infusion of sunflower oil (SO) and flax meal (FM) supplementation on activity of the antioxidant enzymes superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX) in blood and mammary tissue and mRNA abundance of oxidative stress- and lipogenic-related genes in mammary tissue of dairy cows were examined. Eight lactating Holstein cows were assigned to a double 4×4 Latin square design with a 2×2 factorial arrangement of treatments: (1) no FM in the diet (CON); (2) diet containing 13.7g/kg FM; (3) no FM in the diet and 250g SO/d infused in the abomasum; and (4) diet containing 13.7g/kg FM and 250g SO/d infused in the abomasum. mRNA abundance of Kappa-B1 in mammary tissue tended to decrease with FM supplementation, while mRNA abundance of SOD2 tended to increase when SO was infused in the absence of FM in the diet. Fatty acid synthase, lipoprotein lipase and stearoyl-coA desaturase gene expression tended to decrease with SO infusion when cows were fed CON. Infusion of SO decreased mRNA abundance of peroxisome proliferator-activated receptorγ1 in mammary tissue of cows fed CON and sterol regulatory element binding transcription factor 1 expression decreased with SO infusion. In conclusion, FM had no effect on oxidative stress-related gene expression in mammary tissue of cows that were infused with SO in the abomasum. Limited effects were observed on mRNA abundance of antioxidant-related genes in mammary tissue whereas abomasal infusion of SO reduced lipogenic-related gene expression.

Inducing effect of clofibric acid on stearoyl-CoA desaturase in intestinal mucosa of rats.

Fibrates have been reported to elevate the hepatic proportion of oleic acid (18:1n-9) through inducing stearoyl-CoA desaturase (SCD). Despite abundant studies on the regulation of SCD in the liver, little is known about this issue in the small intestine. The present study aimed to investigate the effect of clofibric acid on the fatty acid profile, particularly monounsaturated fatty acids (MUFA), and the SCD expression in intestinal mucosa. Treatment of rats with a diet containing 0.5% (w/w) clofibric acid for 7 days changed the MUFA profile of total lipids in intestinal mucosa; the proportion of 18:1n-9 was significantly increased, whereas those of palmitoleic (16:1n-7) and cis-vaccenic (18:1n-7) acids were not changed. Upon the treatment with clofibric acid, SCD was induced and the gene expression of SCD1, SCD2, and fatty acid elongase (Elovl) 6 was up-regulated, but that of Elovl5 was unaffected. Fat-free diet feeding for 28 days increased the proportions of 16:1n-7 and 18:1n-7, but did not effectively change that of 18:1n-9, in intestinal mucosa. Fat-free diet feeding up-regulated the gene expression of SCD1, but not that of SCD2, Elovl6, or Elovl5. These results indicate that intestinal mucosa significantly changes its MUFA profile in response to challenges by clofibric acid and a fat-free diet and suggest that up-regulation of the gene expression of SCD along with Elovl6 is indispensable to elevate the proportion of 18:1n-9 in intestinal mucosa.

Effects of oils rich in linoleic and α-linolenic acids on fatty acid profile and gene expression in goat meat.

Alteration of the lipid content and fatty acid (FA) composition of foods can result in a healthier product. The aim of this study was to determine the effect of flaxseed oil or sunflower oil in the goat diet on fatty acid composition of muscle and expression of lipogenic genes in the semitendinosus (ST) muscle. Twenty-one entire male Boer kid goats were fed diets containing different levels of linoleic acid (LA) and α-linolenic acid (LNA) for 100 days. Inclusion of flaxseed oil increased (p < 0.05) the α-linolenic acid (C18:3n-3) concentration in the ST muscle. The diet high in α-linolenic acid (p < 0.05) decreased the arachidonic acid (C20:4n-6) and conjugated linolenic acid (CLA) c-9 t-11 content in the ST muscle. There was a significant (p < 0.05) upregulation of PPARα and PPARγ gene expression and downregulation of stearoyl-CoA desaturase (SCD) gene in the ST muscle for the high α-linolenic acid group compared with the low α-linolenic acid group. The results of the present study show that flaxseed oil as a source of α-linolenic acid can be incorporated into the diets of goats to enrich goat meat with n-3 fatty acids, upregulate the PPARα and PPARγ, and downregulate the SCD gene expression.

Interaction of diet and the masou salmon Δ5-desaturase transgene on Δ6-desaturase and stearoyl-CoA desaturase gene expression and N-3 fatty acid level in common carp (Cyprinus carpio)

The masou salmon Δ5-desaturase-like gene (D5D) driven by the common carp β-actin promoter was transferred into common carp (Cyprinus carpio) that were fed two diets. For P1 transgenic fish fed a commercial diet, Δ6-desaturase-like gene (D6D) and stearoyl-CoA desaturase (SCD) mRNA levels in muscle were up-regulated (P<0.05) 12.7- and 17.9-fold, respectively, and the D6D mRNA level in the gonad of transgenic fish was up-regulated 6.9-fold (P<0.05) compared to that of non-transgenic fish. In contrast, D6D and SCD mRNA levels in transgenic fish were dramatically down-regulated (P<0.05), 50.2- and 16.7-fold in brain, and 5.4- and 2.4-fold in liver, respectively, in comparison with those of non-transgenic fish. When fed a specially formulated diet, D6D and SCD mRNA levels in muscle of transgenic fish were up-regulated (P<0.05) 41.5- and 8.9-fold, respectively, and in liver 6.0- and 3.3-fold, respectively, compared to those of non-transgenic fish. In contrast, D6D and SCD mRNA levels in the gonad of transgenic fish were down-regulated (P<0.05) 5.5- and 12.4-fold, respectively, and D6D and SCD mRNA levels in the brain were down-regulated 14.9- and 1.4-fold (P<0.05), respectively, compared to those of non-transgenic fish. The transgenic common carp fed the commercial diet had 1.07-fold EPA, 1.12-fold DPA, 1.07-fold DHA, and 1.07-fold higher observed total omega-3 fatty acid levels than non-transgenic common carp. Although these differences were not statistically different (P>0.05), there were significantly (P<0.10) higher omega-3 fatty acid levels when considering the differences for all of the individual omega-3 fatty acids. The genotype×diet interactions observed indicated that the potential of desaturase transgenesis cannot be realized without using a well-designed diet with the needed amount of substrates.

Abomasal infusion of arginine stimulates SCD and C/EBPß gene expression, and decreases CPT1ß gene expression in bovine adipose tissue independent of conjugated linoleic acid

Based on previous research with bovine peadipocytes, we hypothesized that infusion of arginine into the abomasum of Angus steers stimulates stearoyl-CoA desaturase (SCD) gene expression in bovine subcutaneous (s.c.) adipose tissue, and that this would be attenuated by conjugated linoleic acid (CLA). Growing Angus steers were infused abomasally with L-arginine 50 g/day; n = 13; provided as L-arginine HCl) or L-alanine (isonitrogenous control, 100 g/day; n = 11) for 14 days. For the subsequent 14 days, half of the steers in each amino acid group were infused with CLA (100 g/day). Body weight gain and average daily gain were unaffected (P > 0.15) by infusion of arginine or CLA into the abomasum. The plasma concentrations of cis-9, trans-11 and trans-10, cis-12 CLA were increased CLA infusion (P = 0.001) and infusion of arginine increased plasma arginine (P = 0.01). Compared with day 0, fatty acid synthase, glucose-6-phosphate dehydrogenase, and 6-phosphogluconate dehydrogenase enzyme activities in s.c. adipose tissue increased by day 14 in steers infused with either alanine or arginine (all P < 0.01). NADP-MDH activity was higher (P = 0.01) in steers infused with arginine than in steers infused with arginine plus CLA by day 28, but lipid synthesis in vitro from glucose and acetate was unaffected by infusion of either arginine or CLA (P > 0.40). By day 28, C/EBPβ and SCD gene expression was higher, and CPT1β gene expression was lower, in s.c. adipose tissue of steers infused with arginine than in steers infused with alanine (±CLA) (P = 0.05). CLA decreased adipose tissue oleic acid (18:1n-9) in alanine- or arginine-infused steers (P = 0.05), although CLA had no effect on SCD gene expression. The data indicate that supplemental arginine promotes adipogenic gene expression and may promote lipid accumulation in bovine adipose tissue. L-Arginine may beneficially improve beef quality for human consumption.

Fatty acid remodeling in cellular glycerophospholipids following the activation of human T cells

Changes in fatty acid (FA) and glycerophospholipid (GPL) metabolism associated with cell cycle entry are not fully understood. In this study FA-GPL remodeling was investigated in resting and proliferating primary human T cells. Significant changes were measured in the composition and distribution of FAs in GPLs following receptor activation of human T cells. The FA distribution of proliferating T cells was very similar to that of the human Jurkat T cell line and when the stimulus was removed from proliferating T cells, they stopped proliferating and the FA distribution largely reverted back to that of resting T cells. The cellular content of saturated and monounsaturated FAs was significantly increased in proliferating cells, which was associated with an induction of FA synthase and stearoyl-CoA desaturase-1 gene expression. Additionally, cellular arachidonate was redistributed in GPLs in a distinct pattern that was unlike any other FAs. This redistribution was associated with an induction of CoA-dependent and CoA-independent remodeling. Accordingly, significant changes in the expression of several acyl-CoA synthetases, lysophospholipid acyltransferases, and phospholipase A2 were measured. Overall, these results suggest that metabolic pathways are activated in proliferating T cells that may represent fundamental changes associated with human cell proliferation.