Triglyceride Fatty Acid Research Articles

Red blood cell triglycerides—a unique pool that incorporates plasma-free fatty acids and relates to metabolic health

Most research into red blood cell (RBC) lipids focuses on membrane phospholipids and their relationships to metabolic conditions and diet. Triglycerides (TGs) exist in most cells; the TG-fatty acids serve as readily available fuel for oxidative phosphorylation. Because RBCs lack mitochondria, they would not be expected to store fatty acids in TG. We followed up on a previous in vitro study that found FFA can be incorporated into RBC-TG by testing whether intravenously infused [U-13C]palmitate could be detected in RBC-TG. We also quantified RBC-TG fatty acid concentrations and profiles as they relate to plasma FFA and lipid concentrations. We found that 1) RBC-TG concentrations measured by glycerol and LC/MS were correlated (r = 0.77; P < 0.001) and averaged <50 nmol/ml RBC; 2) RBC-TG concentrations were stable over 18 h; 3) [U-13C]palmitate was detectable in RBC-TG from half the participants; 4) RBC-TGs were enriched in saturated fatty acids and depleted in unsaturated fatty acid compared with plasma FFA and previously reported RBC membrane phospholipids; 5) RBC-TG fatty acid profiles differed significantly between obese and nonobese adults; 6) weight loss altered the RBC-TG fatty acid profile in the obese group; and 7) the RBC-TG fatty acid composition correlated with plasma lipid concentrations. This is the first report showing that plasma FFA contributes to RBC-TG in vivo, in humans, and that the RBC-TG fatty acid profile is related to metabolic health. The storage of saturated fatty acids in RBC-TG stands in stark contrast to the highly unsaturated profile reported in RBC membrane phospholipids.

Fatty acid profile, silymarin content and production properties of milk thistle (

Drought stress has an adverse effect on crop production and food quality. Milk thistle (Silybum marianum L.) is an oil and medicinal crop known as an alternative oil crop with high level of unsaturated fatty acids, which makes it a favourable edible oil for use in food production. Silymarin (a mixture of flavonolignans) is the main active medicinal component. Biochemical diversity, changes induced by water deficit stress in secondary metabolites, and their relationships with production traits in native germplasm are poorly understood in milk thistle. Twenty-six ecotypes mainly collected from different regions of Iran were evaluated for oil, fatty acid profile, triacylglycerol (TAG) composition, silymarin and agro-morphological traits under non-stress and water stress conditions for 2 years. Water stress increased oil and silymarin content while decreasing fruit yield and related traits. The most abundant fatty acid averaged over all ecotypes under both moisture conditions was linoleic acid (L, 39%), followed by oleic acid (O, 36%), palmitic acid (P, 9%) and stearic acid (E, 6%). Among the 24 detected TAGs, the five major compositions were OOL, OLL + OOLn (linolenic), POL, OOO, LLL + OLLn and EOL. Superior ecotypes rich in monounsaturated and polyunsaturated fatty acids were identified and can be introduced as candidates for food, medicinal and industrial purposes. Associations among different attributes are discussed.

CD36 and DGAT2 facilitate the lipid-lowering effect of chitooligosaccharides via fatty acid intake and triglyceride synthesis signaling.

This study examined the impact of chitobiose (GlcN)2 and chitotriose (GlcN)3 on lipid accumulation modification and their inhibitory functionalities. (GlcN)2 and (GlcN)3 significantly inhibited the total cholesterol (TC), triglyceride (TG), and low-density lipid cholesterol (LDL-c) levels in the liver of the ob/ob-/- mice fed a non-high-fat diet. This phenomenon was associated with a reduction in the mRNA and protein expression of TG synthesis and fatty acid uptake-related signaling, significantly affecting the cluster of differentiation 36 (CD36) and diacylglycerol acyltransferase 2 (DGAT2). Furthermore, the CD36 and DGAT2 genes were overexpressed by constructing a plasmid and transfecting it into HepG2 cells, after which the phenotypic traits of lipid accumulation were assessed in vitro. Consequently, it was evident that (GlcN)2 and (GlcN)3 reduced the overexpression of these proteins and relieved cellular lipid accumulation. In conclusion, these results indicated that (GlcN)2 and (GlcN)3 acted positively against NAFLD while regulating steatosis in the non-high-fat diet NAFLD model. The potential NAFLD treatment strategies, such as targeting CD36 and DGAT2 signaling, could provide scientific insight into further applying food-derived ingredients to reduce the risk of high-fat metabolism.

Perilipin 5 S155 phosphorylation by PKA is required for the control of hepatic lipid metabolism and glycemic control

Perilipin 5 (PLIN5) is a lipid-droplet-associated protein that coordinates intracellular lipolysis in highly oxidative tissues and is thought to regulate lipid metabolism in response to phosphorylation by protein kinase A (PKA). We sought to identify PKA phosphorylation sites in PLIN5 and assess their functional relevance in cultured cells and the livers of mice. We detected phosphorylation on S155 and identified S155 as a functionally important site for lipid metabolism. Expression of phosphorylation-defective PLIN5 S155A in Plin5 null cells resulted in decreased rates of lipolysis and triglyceride-derived fatty acid oxidation. FLIM-FRET analysis of protein-protein interactions showed that PLIN5 S155 phosphorylation regulates PLIN5 interaction with adipose triglyceride lipase at the lipid droplet, but not with α-β hydrolase domain-containing 5. Re-expression of PLIN5 S155A in the liver of Plin5 liver-specific null mice reduced lipolysis compared with wild-type PLIN5 re-expression, but was not associated with other changes in hepatic lipid metabolism. Furthermore, glycemic control was impaired in mice with expression of PLIN5 S155A compared with mice expressing PLIN5. Together, these studies demonstrate that PLIN5 S155 is required for PKA-mediated lipolysis and builds on the body of evidence demonstrating a critical role for PLIN5 in coordinating lipid and glucose metabolism.

Gene Expression and Histochemical Analyses in the Fatty Livers of Rats Fed a Histidine-Excess Diet.

Triglyceride (TG) and cholesterol accumulation are known to occur in the liver of rats fed a histidine-excess (5%) diet, but there are few studies reporting histochemical and molecular biological analyses of the rat liver. The aim of this study was to elucidate the molecular basis of this lipid-accumulation mechanism. Lipid accumulations, tissue section images, and gene expression levels were compared in the livers of rats fed a control or histidine-excess diet for 5 wk (n=8/group). Serum levels of TGs, free fatty acids, total cholesterol, high-density lipoprotein cholesterol, glucose, albumin, and the enzyme activities of aspartate aminotransferase and alanine aminotransferase were also analyzed. In the livers of rats fed a histidine-excess diet, histochemical analyses showed what appeared to be a preliminary stage of nonalcoholic fatty liver, characterized by lipid accumulation around the central vein area and minor fibrosis. However, there were no changes in serum TG or free fatty acid levels. Quantitative PCR analyses showed the up-regulation of FAT/CD36, which is related to the uptake of fatty acids into cells, and the downregulation of two apolipoprotein genes, ApoC3 and ApoE. The mRNA levels of PPARγ, LXRα, and AMPKα in the liver were also reduced by excess histidine intake. The results of this study suggest that steatosis caused by excess histidine intake may be the result of an imbalance between lipid transport from the liver and the uptake of free fatty acids into hepatocytes.

EXPERTISE OF POTATO SNACKS BY OPTICAL MICROSCOPY, FTIR - SPECTROSCOPY, SPECTROFLUORIMETRY AND THIN LAYER CHROMATOGRAPHY

Expertise of four samples of potato snacks with the flavours Barbecue, Ketchup, Cheese, Sour Cream and Onion has been carried out with the use of analytical physicochemical methods. It has been found that the mass fraction of moisture in the samples under study ranges 4.4 to 4.7%, and the mass fraction of chlorides does not exceed 2.5%. The mass fraction of starch, which was determined polarimetrically, varies from 66.1% (Sample 2) to 66.7% (Sample 3). The mass fraction of sugars in the potato snack samples does not exceed 1.9%. None of the samples contains foreign material and mineral impurities. The product’s physicochemical quality parameters established by the tests conform to the manufacturer’s indication that the product contains such ingredients as starch and potatoes (starch and proteins are part of potatoes), oil, maltodextrin, sugars, salt, proteins. Based on characteristic absorption bands in the composition of snacks, FTIR has allowed detecting the presence of the two main components: triglycerides of fatty acids (oils) and polysaccharides (the latter include starches and maltodextrins). Optical microscopy has revealed that the samples have a porous (cellular) structure, with pores distributed throughout the whole mass, which is typical of snacks. Heat treatment of the snacks in the course of extrusion and frying changes the structure of starch to the glassy state: only single whole starch grains are found in the samples. The dietary supplement monosodium glutamate E621 has been identified by thin-layer chromatography on chromatographic plates Sorbfil AF-A-UV. The mobile phases were mixtures of ethanol and distilled water in the ratio 7:3, and n- butanol, acetic acid, and water mixed in the ratio 3:1:1. It has been shown that the turmeric extract E100(i), a natural yellow food colourant, being adsorbed on potato snacks, can be identified in them by its own spectra of diffuse reflection and luminescence spectra, without destroying the samples.

Large fluxes of fatty acids from membranes to triacylglycerol and back during N-deprivation and recovery in Chlamydomonas.

Microalgae accumulate triacylglycerol (TAG) during nutrient deprivation and break it down after nutrient resupply, and these processes involve dramatic shifts in cellular carbon allocation. Due to the importance of algae in the global carbon cycle, and the potential of algal lipids as feedstock for chemical and fuel production, these processes are of both ecophysiological and biotechnological importance. However, the metabolism of TAG is not well understood, particularly the contributions of fatty acids (FAs) from different membrane lipids to TAG accumulation and the fate of TAG FAs during degradation. Here, we used isotopic labeling time course experiments on Chlamydomonas reinhardtii to track FA synthesis and transfer between lipid pools during nitrogen (N)-deprivation and resupply. When cells were labeled before N-deprivation, total levels of label in cellular FAs were unchanged during subsequent N-deprivation and later resupply, despite large fluxes into and out of TAG and membrane lipid pools. Detailed analyses of FA levels and labeling revealed that about one-third of acyl chains accumulating in TAG during N-deprivation derive from preexisting membrane lipids, and in total, at least 45% of TAG FAs passed through membrane lipids at one point. Notably, most acyl chains in membrane lipids during recovery after N-resupply come from TAG. Fluxes of polyunsaturated FAs from plastidic membranes into TAG during N-deprivation were particularly noteworthy. These findings demonstrate a high degree of integration of TAG and membrane lipid metabolism and highlight a role for TAG in storage and supply of membrane lipid components.

Fatty acid, triacylglycerol and minor component profiles affect oxidative stability of camelina and sophia seed oils

The fatty acid composition, triacylglycerol (TAG) profile, tocopherols, and oxidative stability of camelina and sophia seed oils, in the dark and under light, were evaluated. The significance of minor components to the stability of the oils was also examined upon their removal from the oil. A recently developed novel stripping method was employed for this purpose. Storage in the dark and under light dictated the stability of both stripped and non-stripped oils. Tested oil samples contained a high level of α-linolenic acid, 36.14–46.23 g/100 g oil. Five major TAG, namely LnLLn, LnLnLn, LnOLn, LLLn, and C20:2LL, were present in both oils. Total tocopherol contents were 1150.93–1262.54 ppm and comprised of α-, β-/γ-, and δ-tocopherols in sophia and camelina oils. Oxidative stability of the seed oils was affected by their fatty acid composition, triacylglycerols profiles, storage conditions, and minor components.

A comparison of extraction yield, quality and thermal properties from Sapindus mukorossi seed oil between microwave assisted extraction and Soxhlet extraction

To improve the extraction efficiency and quality, microwave assisted extraction (MAE) method was proposed for separating oil from Sapindus mukorossi seed and compared with Soxhlet extraction (SE). The optimal condition of MAE obtained by Box-Behnken design was the mixed solvent of n-hexane and ethanol (4:1, v/v) as extraction solvent, microwave power 460 W, solvent to material ratio 8 mL/g, extraction temperature 72℃ and time 42 min. Under optimum conditions, the oil yield of 40.12 % was achieved, which was similar to that (40.63 %) of SE. All the oils shown similar fatty acid profiles, triglyceride profiles and thermal behavior. But the oil by MAE had better quality than that of SE, especially on low acid value and peroxide value. Additionally, solvent to material ratio, extraction time, energy consumption and carbon dioxide emission of MAE were lower than those of SE. It was shown from observation with a scanning electron microscopy that the structure of raw materials was destroyed by microwave treatment, which promoted the rapid extraction of oil. Overall, the results from this study suggest that MAE is an efficient and eco-benign method to extract oil from Sapindus mukorossi seed.

Prenatal androgen exposure affects ovarian lipid metabolism and steroid biosynthesis in rats.

Prenatal androgen exposure affects reproductive functions and has been proposed as an underlying cause of polycystic ovary syndrome (PCOS). In this study, we aimed to investigate the impact of prenatal androgen exposure on ovarian lipid metabolism and to deepen our understanding of steroidogenesis regulation during adulthood. Pregnant rats were hyperandrogenized with testosterone and female offspring were studied when adult. This treatment leads to two different phenotypes: irregular ovulatory and anovulatory animals. Our results showed that prenatally hyperandrogenized (PH) animals displayed altered lipid and hormonal profile together with alterations in steroidogenesis and ovarian lipid metabolism. Moreover, PH animals showed alterations in the PPARg system, impaired mRNA levels of cholesterol receptors (Ldlr and Srb1) and decreased expression of the rate-limiting enzyme of de novo cholesterol production (Hmgcr). Anovulatory PH animals presented an increase of ovarian cholesteryl esters levels and lipid peroxidation index. Together with alterations in cholesterol metabolism, we found an impairment of the steroidogenic pathway in PH animals in a phenotype-specific manner. Regarding fatty acid metabolism, our results showed, in PH animals, an altered expression of Srebp1 and Atgl, which are involved in fatty acid metabolism and triglycerides hydrolysis, respectively. In conclusion, fatty acid and cholesterol metabolism, which are key players in steroidogenesis acting as a source of energy and substrate for steroid production, were affected in animals exposed to androgens during gestation. These results suggest that prenatal androgen exposure leads to long-term effects that affect ovary lipid metabolism and ovarian steroid formation from the very first steps.

Three different C: N ratios for Pacific white shrimp, Penaeus vannamei under practical conditions: Evaluation of growth performance, immune and metabolic pathways

A 28-day experiment was carried out to evaluate different C/N ratios (10:1, 15:1 and 20:1) on growth performance, water quality, survival rate and gene expression related to metabolic pathways of Penaeus vannamei in a biofloc system. To maintain the C/N ratio of the feed input, different carbon sources (molasses, rice bran and wheat flour) in combination were applied after fermentation for a day with biofloc consortium. Results showed that shrimps reared in C/N 10 (630 mg) and C/N 15 (646 mg) biofloc systems showed significantly (p = .0229 and .0263) higher growth when compared to C/N 20 (528 mg) and control (374 mg). With regard to the production of extracellular enzymes, protease, lipase and xylanase were found predominantly in colonized bacteria isolated from biofloc treatments, whereas amylase was commonly found in all the treatments. The proPO activity was considerably increased in C/N 10 and 15 treatments than C/N 20 and control. The ranges of relative expression levels of potential genes entailed in metabolite pathway like hexokinase (HK- 6.57–8.17), pyruvate kinase (PK-5.79–7.96), crustacean hyperglycaemic hormone (CHH- 6.99–7.66) and fatty acid synthase (FAS- 6.57–8.86), triacylglycerol lipase (TGL-6.99–8.66) and immune gene (Toll receptor- 4.57–4.86) fold up-regulated expression were observed in the biofloc treatments than that of the control. The overall findings indicate that the rearing of P. vannamei shrimp in C/N 10 and 15 biofloc systems could improve the growth performance, water quality and development of immune and metabolic responses.

In-depth analysis of potential PaAP2/ERF transcription factor related to fatty acid accumulation in avocado (Persea americana Mill.) and functional characterization of two PaAP2/ERF genes in transgenic tomato

Fatty acids in avocado fruit are crucial components influencing taste as well as fruit quality and nutritional value. Changes to fatty acid contents and concentrations in avocado fruit are important because of the associated effects on sensory properties. Hence, plant physiologists and molecular biologists interested in elucidating the influence of transcription factors on fatty acid accumulation in avocado fruit. In this study, APETALA2/ethylene-responsive factor (AP2/ERF) family members in avocado (Persea americana Mill.) were systematically and comprehensively analyze to identify potential PaAP2/ERF genes related to fatty acid accumulation. The results of bioinformatics analysis and the expression profiles of the AP2/ERF members suggested that 10 highly expressed PaAP2/ERF genes may encode transcription factors with functions related to the fatty acid accumulation in the avocado mesocarp. Furthermore, PaWRI1 and PaWRI2, two AP2/ERF transcription factor genes in avocado, were functionally characterized regarding their effects on fatty acid accumulation. The transcriptome and biochemical analyses of PaWRI1-2-overexpressing transgenic tomato plants revealed the up-regulated expression of 17 unigenes related to fatty acid synthesis and triacylglycerol assembly as well as increased fatty acid contents relative to the corresponding levels in the wild-type plants. In contrast, the overexpression of PaWRI2 in transgenic tomato plants up-regulated the expression of only six unigenes associated with fatty acid synthesis and triacylglycerol assembly and negligibly affected fatty acid accumulation when compared with wild-type plants. This systematic analysis provides a foundation for future studies regarding AP2/ERF functions associated with fatty acid accumulation.

Nutritional Values and Health Protective Properties Of Coconut Oil

Chemically, fat or oil is a mixture of triacylglycerol molecules, in which glycerol esterified with three fatty acids. Fatty acid is a monocarboxilic acid containing even number of carbon atom started from 4 to 22. Based on the length of fatty acid in triacylglycerol, fats and oils can be classified into two groups; medium chain triglycerides and long chain triglycerides. Coconut oil belongs to medium chain triglycerides oil because it’s fatty acids consist mostly of medium chain fatty acids (C4:0 to C12:0) and dominated by lauric acid (C12:0), hence usually called as lauric oil. In the year of 1950s, coconut oil was claimed that saturated fats, including coconut oil, could increase blood total cholesterol and hence is atherogenic, while unsaturated fats decrease total cholesterol. However, in 1990s, coconut oil was found to be different from the other saturated oils. Coconut oil composed of medium chain fatty acids with high amount of lauric acid. Coconut oil is metabolized differently from long chain triglycerides saturated oil, and therefore coconut oil has numerous beneficial nutritional values and health promotion. Consumption of food rich in medium chain fatty acids reduces the level of body fat and the decrease the risk of heart disease, diabetes, increase mother’s milk quality and active as potential antibacterial agent.&#x0D;

Lipid class and fatty acid composition of oil extracted from Atlantic salmon by-products under different optimization parameters of enzymatic hydrolysis

Abstract Six operational parameters, including fish part, antioxidant use, water addition, enzyme types, enzyme concentration and hydrolysis time, were studied about their effect on nutritional composition of oil enzymatically extracted from farmed Atlantic salmon by-products. Compared to the oil extracted from salmon viscera, the oil extracted from mixture of salmon heads and frames had higher amounts of triacylglycerols (TAGs), omega-3 polyunsaturated fatty acids (PUFAs), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), and lower amounts of omega-6 PUFAs. The interaction between water and high levels of hydrolysis time (4 h) or enzyme concentration (1%) resulted in decreased TAG content, increased content of phospholipids (PLs) and increased omega-6 PUFA content. The addition of antioxidant significantly increased the average content of omega-6 PUFAs, but decreased EPA and DHA amounts in viscera oil due to the pro-antioxidant activity of ascorbic acid. The use of Alcalase, Flavourzyme or SEBPRo didn't result in any significant difference in oil composition under studied conditions. The negative correlation between amounts of TAG and free fatty acid (FFA) indicates that the increase of FFA content resulted in the decrease of TAG content, mainly due to the oxidation of TAG promoted by FFAs.

A rapid and highly sensitive UPLC-ESI-MS/MS method for the analysis of the fatty acid profile of edible vegetable oils

The analysis of the fatty acid profile of triglycerides has long played a central role in the evaluation and classification of edible vegetable oils. However, the range of analytical procedures available to evaluate these profiles remains limited and are typically based on transesterification of the triglyceride fatty acid residues to methyl esters, followed by capillary gas–liquid chromatography (GC) coupled with flame ionization or mass spectrometry detection. Although robust and long-proven, these analytical methods tend to entail long chromatographic runs and are relatively insensitive. In order to expand the range of available techniques for the analysis of the fatty acid profile of triglycerides in vegetable oils, we report herein a novel method based upon a rapid and straightforward transesterification of the triglycerides with dimethylaminoethanol under alkaline conditions, followed by a “dilute-and-shoot” analysis by ultra-performance liquid chromatography coupled with electrospray tandem mass spectrometry. The chromatographic analysis is accomplished in 1.5 min, affording a high throughput of samples compared to techniques based upon GC approaches. The method performance was assessed intra- and inter-day with 10 representative saturated and unsaturated fatty acids ranging from C8 to C18 and afforded fatty acid profile accuracies of 93–108% and imprecisions of only 0.3–2.0%. The limit of quantification of the method, estimated as the minimum amount of derivatized oil sample capable of affording less than 20% accuracy and precision error was determined to be approximately 0.5 pg on-column, making this new method potentially valuable for fields where high sensitivity, precision, and accuracy may be required, such as in toxicology studies, forensics, archeology, or art analysis.

FoxO1 Knockdown Promotes Fatty Acid Synthesis via Modulating SREBP1 Activities in the Dairy Goat Mammary Epithelial Cells.

FoxO1 is a crucial transcription factor involved in lipid metabolism in mouse liver through repressing a key regulator of lipogenesis, sterol regulatory element binding protein 1 (SREBP1). However, it remains elusive whether FoxO1 plays roles in the regulation of fatty acid metabolism during lactation in dairy goats. In this study, we aim to investigate the function of FoxO1 in goat mammary epithelial cells (GMECs). We found that the expression of FoxO1 is significantly upregulated during lactation compared with the dry period. FoxO1 knockdown enhanced the expression of genes related to de novo fatty acid synthesis (e.g., FASN, ELOVL6 and SCD1) and triacylglycerol (TAG) synthesis (e.g., DGAT2 and GPAM). Consistently, intracellular TAG was significantly increased in FoxO1 knockdown cells and reduced in FoxO1 overexpression cells. Immunofluorescence staining revealed that insulin suppresses FoxO1 transcription by promoting its nuclear export. Further, we found that FoxO1 inhibits insulin-induced SREBP1 promoter activities in GMECs. Moreover, FoxO1 suppresses SREBP1 transcription via the LXR response element (LXRE) and SREBP response element (SRE) located in the SREBP1 promoter. Our data reveal that FoxO1 plays critical roles in regulating the synthesis of the fatty acid and triacylglycerol (TAG) in GMECs.

Development and in vitro evaluation of mucoadhesive gelatin films for the vaginal delivery of econazole.

Several strategies have been explored to obtain effective econazole nitrate (ECN) concentrations at the site of application for a prolonged time. In this paper, different gelatin-based film formulations for vaginal application were investigated, containing ECN (10% w/w with respect to gelatin) as pure drug or as drug-solid dispersions (SD). For the production of SD, different polymers were evaluated: polyvinylpyrrolidone (PVP), Soluplus® (polyvinyl caprolactam-polyvinyl acetate-polyethylene glycol graft copolymer) and Gelucire® 50/13 (mixture of mono-, di- and triglycerides of fatty acids, esters of PEG 1500 and free PEG). Gelucire®-SD showed the best solubility enhancement, increasing 9.2 times the ECN solubility in pH 4.5 solution respect to pure drug; DSC and XRD analysis confirmed the crystalline form of the drug. XRD results evidenced that all gelatin-based films, containing either the drug or the SD, underwent the topotactic transformation of ECN into crystalline econazole (EC), owing to a strong interaction between the drug and the gelatin. Films containing Gelucire®-based SD displayed lower brittleness and rigidity with respect to the other samples; moreover they demonstrated good structural integrity after 24h of incubation in the acidic solution (swelling degree of about 350%). Then, Gelucire®-SD based films were compared with the corresponding formulations cross-linked by genipin (2% w/w). The addition of genipin did not interfere with the drug-gelatin interaction. Gelucire®-SD based films showed similar release profiles to neat gelatin films, enhancing the drug release in the first 5h and controlling the EC release over time, avoiding the use of a crosslinking additive. Finally, gelatin films containing Gelucire® solid dispersion displayed good adhesiveness and anti-Candida activity. Overall, results support the potential use of this film formulation as noncytotoxic EC delivery system for the treatment of vaginal candidiasis.

CAMP Response Element Binding Protein 1 (CREB1) Promotes Monounsaturated Fatty Acid Synthesis and Triacylglycerol Accumulation in Goat Mammary Epithelial Cells.

Simple SummaryIn non-ruminant liver and adipose tissue, cAMP response element binding protein 1(CREB1) is essential for lipid synthesis and triacylglycerol accumulation. The present study aimed to ascertain the role of CREB1 in regulating milk fatty acid composition synthesized by goat mammary gland. Our data found that overexpression of CREB1 in vitro alters the abundance of lipogenic genes, triacylglycerol accumulation and concentration of monounsaturated fatty acids in goat mammary epithelial cells. Thus, manipulation of CREB1 in vivo might be one approach to improve the quality of goat milk.cAMP response element binding protein 1 (CREB1) is a member of the leucine zipper transcription factor family of DNA binding proteins. Although studies in non-ruminants have demonstrated a crucial role of CREB1 in lipid synthesis in liver and adipose tissue, it is unknown if this transcription regulator exerts control of fatty acid synthesis in ruminant mammary cells. To address this question, we first defined the expression dynamics of CREB1 in mammary tissue during lactation. Analysis of CREB1 in mammary tissue revealed higher mRNA abundance in mammary tissue harvested at peak lactation. Overexpression of CREB1 markedly upregulated sterol regulatory element binding transcription factor 1 (SREBP1), fatty acid synthase (FASN), acetyl-coenzyme A carboxylase α (ACACA), elongase of very long chain fatty acids 6 (ELOVL6), lipoprotein lipase (LPL), fatty acid binding protein 3 (FABP3), lipin 1 (LPIN1) and diacylglycerol acyltransferase 1 (DGAT1), but had no effect on glycerol-3-phosphate acyltransferase, mitochondrial (GPAM) or 1-acylglycerol-3-phosphate O-acyltransferase 6 (AGPAT6). In addition, overexpressing CREB1 led to a significant increase in the concentration and desaturation index of C16:1 (palmitoleic acid) and C18:1 (oleic acid), along with increased concentration of triacylglycerol. Taken together, these results highlight an important role of CREB1 in regulating lipid synthesis in goat mammary epithelial cells. Thus, manipulation of CREB1 in vivo might be one approach to improve the quality of goat milk.

No effect of 10 weeks erythropoietin treatment on lipid oxidation in healthy men.

Studies indicate that erythropoietin (EPO) has effect on lipid and energy metabolism; however, the impact of EPO on lipid oxidation in vivo has not been well documented. Here, we evaluate whether long-term erythropoiesis-stimulating agent (ESA) treatment affects the oxidation of plasma very low-density lipoprotein triglycerides (VLDL-TG) fatty acids (FA), plasma free fatty acids (FFA) and non-plasma (residual) FA in healthy, young, sedentary men. Infusion of [1-14C]VLDL-TG and [9,10-3H]palmitate was used in combination with indirect calorimetry to assess resting lipid fuel utilization and kinetics, and resting energy expenditure (REE) before and after 10 weeks of ESA exposure compared with placebo. REE increased significantly during ESA compared with placebo (P = 0.023, RM-ANOVA). Oxidation rates of VLDL-TG FA, FFA, and residual FA remained unchanged during ESA compared with placebo. The relative contribution of the lipid stores was greatest for FFA (47.1%) and the total lipid oxidation rate and was not significantly different between ESA and placebo-treated subjects. We conclude that long-term ESA treatment of healthy young men increases REE but does not alter the oxidation rates of plasma and non-plasma FA sources.

Fatty acids of follicular fluid phospholipids and triglycerides display distinct association with IVF outcomes

Research questionAre triglyceride fatty acids in the follicular fluid associated with either follicular fluid phospholipid fatty acids or IVF outcomes and, if so, how are they associated? DesignIn a prospective cross-sectional study, 70 women undergoing intracytoplasmic sperm injection were recruited. Follicular fluid phospholipids and triglycerides were separated by thin-layer chromatography. Fatty acids were measured using gas-liquid chromatography and flame ionization detection system. ResultsSignificant differences in fatty acid composition were observed between follicular fluid phospholipid and triglyceride fractions. Phospholipid stearic acid and n-3 polyunsaturated fatty acids, particularly alpha-linolenic acid, were negatively associated with the number of mature oocytes and cleaved embryos, whereas arachidonic acid was in direct correlation with cleavage rate per IVF cycle (β = 0.325, P = 0.022). In the case of triglyceride fraction, total monounsaturated fatty acids, oleic acid in particular, displayed significantly positive associations with the number of oocytes (β = 0.261, P = 0.043) and embryos (β = 0.310, P = 0.018). Furthermore, cleavage rate correlated inversely with palmitic acid (β = –0.359, P = 0.007) and directly with pentadecanoic acid (β = 0.378, P = 0.005). Most of these associations, however, were not independent of predictive fatty acids belonging to phospholipid fraction, according to multivariate analysis. ConclusionsFatty acid compositions of phospholipid and triglyceride fractions from human follicular fluid differentially correlate with IVF cycle parameters.